Copper base PCB delamination is one of the most frustrating and critical issues for engineers and buyers alike. When layers of the PCB separate, it compromises thermal performance, mechanical strengthen electrical safety. Whether it happens during soldering or while in use, understanding how to prevent and respond to delamination is vital for long-term reliability.
What Is Delamination in Copper Base PCBs?
Delamination refers to the separation of different material layers in the copper base PCB structure. This usually occurs between the copper foil and the insulating dielectric or between the dielectric and the metal base. It is often visible as bubbles, warping, or peeling, and can even lead to electrical failure.
Delamination is a sign of poor adhesion, excessive internal stress, or improper material pairing. While it may seem like a production flaw, in many cases, it is a result of both design and process-related decisions.
Common Causes of Delamination in Copper Base PCB
1. Mismatch in Thermal Expansion Coefficient (CTE)
The CTE mismatch between copper, dielectric resin, and metal base can generate internal stress during temperature cycling, leading to separation over time.
2. Poor Lamination Process
If the lamination pressure is too low, or the vacuum environment is inadequate, resin will not bond well with copper. This creates weak interfaces that can easily delaminate during reflow or wave soldering.
3. Excessive Heat or Thermal Shock
Copper base PCBs used in LED, power, or automotive sectors often undergo extreme temperatures. Rapid heating or cooling during soldering can exceed the material’s limit and cause bubbling or blistering.
4. Moisture Absorption
If the PCB absorbs moisture during storage or processing, it will vaporize during soldering, forming vapor pressure that forces the layers apart.
5. Mechanical Drilling Stress
For thick copper or multilayer copper base PCBs, improper drilling parameters may introduce mechanical stress that fractures the resin bond.
Signs That Your Copper Base PCB Is Delaminating
Bubbles or bulges under the copper foil
Peeling or flaking of surface copper
Warping or deformation after soldering
Burn marks or internal voids seen in X-ray or ultrasonic scans
Circuit opens or intermittent connections
How to Handle Delamination During Production?
If you detect delamination during prototype or volume production:
1. Stop and Identify the Root Cause:
Perform cross-sectional analysis of the delaminated area.
Check resin flow, press temperature, and bonding pressure during lamination.
Verify vacuum level and lamination time.
2. Adjust the Lamination Process:
Increase bonding pressure and resin flow time.
Use vacuum lamination with temperature ramping.
Switch to a resin system with better heat resistance and adhesion.
3. Dry the Material Before Lamination:
Bake prepregs and metal cores at 120–150°C for 2–4 hours to eliminate moisture.
4. Use Better Dielectric Materials:
Use thermally conductive epoxy with higher Tg and lower CTE.
Consider ceramic-filled resins for high-power applications.
1. Check if soldering parameters were too aggressive
Overheating or reflow profiles with steep ramps can cause internal separation.
2. Inspect PCB storage and packaging
Improper vacuum sealing or exposure to humidity can lead to moisture buildup.
3. Request reliability test reports from the supplier
Ensure your supplier provides thermal cycling, cross-section, and peel strength data for the batch.
How to Prevent Delamination in Copper Base PCB Designs?
Preventing delamination requires a combined effort in material selection, stack-up design, processing parameters, and storage control. Here’s how to prevent & reduce the risk of delamination from the ground up.
1. Use High-Quality Dielectric Materials
One of the most direct ways to prevent delamination is choosing a dielectric layer with excellent adhesion properties and low moisture absorption. In copper base PCB design, typical dielectrics include thermally conductive epoxy, ceramic-filled resin, or polyimide.
What to look for in dielectric material:
High Tg (Glass Transition Temperature) above 150°C
Low CTE (Coefficient of Thermal Expansion) for better mechanical stability
High peel strength to enhance bonding with copper
Thermal conductivity ≥ 1.0 W/m·K for effective heat transfer
2. Choose the Right Stack-up for Your Application
If your design needs high thermal conductivity, select a resin with high Tg and low CTE to reduce internal stress.
3. Design Even Copper Distribution
Avoid heavy copper areas on one side only, which can cause warping or asymmetrical expansion during soldering.
4. Pre-bake the PCB Before Reflow
Even if your supplier provides vacuum-packed boards, pre-baking before SMT helps prevent delamination from moisture.
5. Set Realistic Soldering Profiles
Avoid shock heating. Ramp temperature gradually and stay within resin limits.
6. Proper Drill Parameters and Hole Cleaning
For multilayer copper base PCBs, drilling through copper and resin layers generates mechanical stress. Improper drill speed, feed rate, or dull drill bits can cause micro-cracks, which may propagate and cause delamination.
7. Avoid Sharp Thermal Transitions in Reflow Soldering
Rapid heating or cooling causes materials to expand or contract at different rates. If the resin can’t keep up, it will delaminate.
Copper base PCB delamination is not just a fabrication problem — it’s also a design and process challenge. By carefully selecting materials, managing thermal profiles, and working with professional PCB manufacturers, you can significantly reduce the risk.
FAQs
Q1: What causes copper base PCB to delaminate after soldering?
Rapid heating, high peak temperature, or moisture buildup in the board are the most common causes.
Q2: How can I test whether my copper base PCB has internal delamination?
You can use ultrasonic scanning (C-SAM), X-ray imaging, or destructive cross-sectioning.
Q3: What’s the ideal copper thickness to reduce delamination risk?
While thicker copper helps heat dissipation, it also introduces stress. A balance between 2oz–4oz copper and suitable resin is ideal.
Q4: Can I rework a delaminated copper base PCB?
In most cases, no. Once delaminated, the structural and electrical integrity is compromised.
Q5: What files should I provide to the manufacturer to ensure better reliability?
Gerber files, stack-up drawing, copper weight details, thermal simulations (if any), and assembly temperature profiles.
Why Choose Best Technology?
Best Technology specializes in high-reliability copper base PCBs for LED, power, and automotive markets. We apply vacuum press lamination, use high-Tg resins, and perform 100% inspection on thermal integrity. Whether you need single-layer, double-layer, or heavy copper designs, we provide reliable solutions backed by engineering support.
Let us help you optimize your copper base PCB design to prevent delamination and maximize thermal and mechanical stability.
If you’ve ever tried to get a copper core PCB prototyped, you might have experienced sticker shock. Compared to standard FR4 or even aluminum PCBs, copper base PCB prototyping is significantly more expensive. But why is that? Is it just the material cost—or is there more behind the pricing?
This article explores why copper core PCB prototyping is expensive, highlighting the five core factors that affect the price. If you’re planning to prototype with copper, this guide will help you manage expectations and control costs without compromising quality.
1. High Raw Material Cost of Copper Base PCB
Copper is a premium metal. Compared to aluminum or traditional FR4 materials, copper base PCBs use significantly more raw copper, especially for heavy copper designs (2oz to 10oz). Thick copper requires more material, which increases raw material cost.
Besides the copper layer, these PCBs often use advanced insulation materials like ceramic or high-conductivity epoxy, which are not cheap. Together, they make copper base PCB a costlier substrate right from the start.
2. Copper Core Is Costlier and Harder to Process
Copper base PCBs are built on metal substrates where copper is used as the base material. Compared to aluminum PCBs, copper-based substrates have higher thermal conductivity and mechanical strength—but also come at a premium.
Challenges:
Copper is heavier and more difficult to machine than aluminum.
It demands higher-grade dielectrics to manage heat flow and electrical insulation.
Machining tolerance must be tight, which often requires CNC milling or laser cutting.
In prototyping, every material switch requires reprogramming and tool setup—this adds to unit cost, especially for small batches.
3. Full-Process Manufacturing for Low Volumes = High Unit Cost
Many customers expect prototyping to be a simplified process, but copper PCB prototypes go through the full manufacturing workflow, just like mass production.
Involved Steps:
Lamination of copper foil and dielectric layer onto the metal core
Photolithography and etching of thick copper traces
Drilling and metal plating through holes (if applicable)
Solder mask and silkscreen application
Surface finish such as HASL, ENIG, or OSP
Electrical and AOI testing
Unlike FR4 samples, these steps for copper PCBs are more labor-intensive and require custom setup, making short runs costly.
4. Board Size and Quantity: Small Orders Still Use Full Panels
You might think that fewer boards mean lower cost—but that’s not how copper PCB prototyping works. Manufacturers need to process entire panels, even if the customer only needs one or two pieces.
Key Considerations:
Panel utilization is poor for unique shapes or non-standard sizes.
Tooling, drilling, and routing costs remain fixed regardless of quantity.
Wasted copper material adds to the final quote.
5. Testing and Quality Control Requirements Raise the Bar
Copper base PCBs are commonly used in high-power LED lighting, automotive control units, power supplies, and military devices. These applications demand precise thermal performance, which must be verified in prototypes.
Extra Testing:
Dielectric strength and thermal conductivity evaluation
X-ray or AOI inspections to verify copper-to-core bonding
Flatness and planarity checks
Anti-oxidation packaging for copper exposure protection
While FR4 or aluminum PCBs may pass with visual inspection, copper PCB prototyping requires intensive quality checks to simulate performance under real-world stress.
In addition to this, only a small percentage of PCB manufacturers have the equipment, technology, and skilled workers to prototype copper base PCBs. These facilities often run specialized machinery and require higher operational overheads. That exclusivity creates a supply-demand gap, increasing pricing. Furthermore, setup for copper PCBs takes more time — involving tool calibration, stack-up configuration, and thermal modeling — all of which raise prototyping expenses.
How to Lower Your Copper PCB Prototyping Cost?
While you can’t eliminate the inherent cost of copper core PCB prototyping, you can definitely make smart choices to reduce waste and improve cost-efficiency. Here are strategic steps engineers and procurement teams can take:
1. Choose the Right Copper Thickness
Avoid overengineering. While 5oz or more copper might seem safer, most designs perform well with 2oz to 3oz copper thickness. This keeps etching time, material use, and plating costs within reason.
2. Standardize Your Board Shape and Size
Odd-shaped PCBs or extremely small panels lead to poor panel utilization. Try to stick to standard sizes like 100mm x 100mm or 150mm x 150mm, which optimize production yields and reduce cutting loss.
3. Simplify the Initial Design
Avoid complex features such as plated through-holes, cavities, or selective surface finishes in your prototype stage. These features add cost and are often not required for first-round validation.
4. Use Cost-Efficient Dielectrics
For less heat-sensitive applications, consider standard ceramic or polymer-based insulation layers rather than high-cost options like AlN unless required. Choosing the right dielectric saves material and processing time.
5. Avoid Over-Specifying Surface Finishes
Electroless Nickel Immersion Gold (ENIG) is often used, but it’s not always necessary. If you don’t need high wire bonding or long shelf life, consider OSP or HASL—these finishes are far more affordable.
6. Batch Your Orders to Improve Panel Utilization
If you plan to order multiple revisions or versions, ask your manufacturer if they can combine them in a single panel. This reduces setup time and improves manufacturing efficiency.
Why Choose Best Technology for Copper Core PCB Prototyping?
At Best Technology, we specialize in copper base PCB manufacturing and prototyping. We understand the thermal, electrical, and mechanical demands of your application—and we’re here to support you at every step.
Our Advantages:
In-house CNC machining for precise panel shaping
Extensive material inventory including standard and heavy copper
MES traceability and full-process quality inspection
Thermal simulation support before prototyping
Global shipping with vacuum-sealed packaging
One-on-one engineering consultation for design reviews
Free DFM & DFA checks
We’re certified under ISO9001, ISO13485, IATF16949, and AS9100D, making us a reliable partner for medical, automotive, and aerospace industries.
Conclusion
If you’re planning to develop high-power or heat-sensitive electronics, copper core PCB prototyping is a strategic investment. While the costs may seem high initially, understanding the five main cost factors gives you more control over your design and procurement decisions.
Looking to reduce the copper PCB sample price while maintaining performance? Contact Best Technology for a free quote and technical design review.
Frequently Asked Questions (FAQs)
1. Why is copper base PCB prototyping more expensive than aluminum PCB samples?
Copper is costlier and harder to machine. It also needs special insulation materials and more precise control during manufacturing, which adds to the overall expense.
2. Can I use thinner copper to reduce prototyping costs?
Yes, 2oz or 3oz copper works well for most thermal and current needs. Always confirm with your PCB supplier.
3. Is SMD-only design more cost-effective for copper PCBs?
Absolutely. Using SMD components eliminates through-holes and makes the manufacturing process simpler and cheaper.
4. How can I estimate copper PCB prototyping cost?
Submit your Gerber files, copper weight, board dimensions, and finish requirements to your supplier for an accurate quote.
5. What files should I provide to the manufacturer?
You should prepare and send your Gerber files (RS-274X), drill file, copper thickness, stack-up details, fabrication notes, and BOM (if assembly is needed). This ensures fast and accurate quotation and fabrication.
Struggling to source responsiveLED lighting PCB assembly services? Struggling to source responsive LED lighting PCB assembly service? Discover its benefits, application, supplier evaluation tips. reduction cost methods.
Best Technology deliversLED lighting PCB assembly solutions with a vertically integrated supply chain, ensuring uninterrupted access to premium components even during global shortages. Our automated SMT lines and dedicated engineering team enable rapid prototyping in 24 hours and full-scale production within 3-5 days, while emergency orders benefit from prioritized 24-hour turnaround – all backed by strict IPC-A-610 Class 3 quality control for <0.1% defect rates. By combining thermal-optimized DFM analysis (2-6oz copper core integration) with smart panelization algorithms, we reduce material waste by 18% and assembly costs by 15% without compromising luminous consistency (±3% flux variance). Whether you’re developing UV sterilization systems or smart horticultural lighting, our scalable capacity handles 1-piece prototypes to 50k+ batches with identical precision. Welcome to contact us for free design review if you have any request for LED lighting PCB assembly: sales@bestpcbs.com.
What Is LED Lighting PCB Assembly?
LED lighting PCB assemblyrefers to the specialized process of integrating light-emitting diodes (LEDs) onto printed circuit boards (PCBs) to create functional illumination systems. This involves precise placement of SMD or COB LEDs, resistors, drivers, and thermal management components onto substrates like aluminum-core or FR4 boards, ensuring stable electrical connections and heat dissipation. Advanced techniques such as automated pick-and-place machines, reflow soldering, and conformal coating are applied to achieve consistent brightness, color temperature accuracy (e.g., 3000K warm white), and resistance to environmental stressors like moisture or vibration. The assembly supports diverse applications, from automotive lighting to architectural accents, balancing energy efficiency with mechanical durability while adhering to industry standards for safety and performance.
Why Choose LED Lighting PCB Assembly?
Advantages of LED lighting PCB assembly:
Efficient Production for Rapid Turnaround – LED lighting PCB assembly streamlines manufacturing through automated processes, enabling quick prototyping and bulk production. Advanced SMT lines and modular workflows ensure fast delivery even for complex designs like high-power automotive lighting systems.
Precision-Driven Quality Assurance – Every LED lighting PCB assembly undergoes multi-stage inspections, including automated optical (AOI) and X-ray testing, to eliminate defects such as solder bridging or component misalignment. This guarantees reliability in harsh environments like outdoor signage or industrial lighting.
Expert Support for Design Optimization – Collaborate with engineers who specialize in thermal management and electrical performance for LED lighting. Their insights help avoid common pitfalls, such as improper trace spacing or inadequate heat dissipation, reducing redesign risks and assembly costs.
Scalable Solutions for Custom Applications – From single-board prototypes to large-scale batches, LED lighting PCB assembly adapts to diverse project needs. Examples include tunable horticultural grow lights and dimmable architectural panels, all built with consistent precision.
Cost-Effective Material Sourcing – Partnerships with certified suppliers ensure access to high-performance substrates like aluminum-core PCBs and ceramic-filled laminates. This balances durability and budget, critical for projects like street lighting or commercial fixtures.
Long-Term Durability Under Stress – Rigorous thermal cycling and humidity tests validate that LED lighting PCB assemblies withstand extreme conditions. This is vital for mission-critical applications such as emergency lighting or marine navigation systems.
Sustainability in Manufacturing – Eco-friendly practices, including lead-free soldering and recyclable packaging, align LED lighting PCB assembly with global environmental standards. Energy-efficient processes further reduce carbon footprints for clients prioritizing green compliance.
What Are Application of LED Lighting PCB Assembly?
Application of LED lighting PCB assembly:
Architectural and Commercial Lighting
Office/Retail Spaces: Recessed troffers, panel lights, and linear fixtures use LED PCBs for uniform, flicker-free illumination.
High-End Interiors: Customizable CCT (2700K–6500K) and CRI (>90) options enhance aesthetics in museums, galleries, and luxury retail.
Smart Buildings: Integration with occupancy sensors, daylight harvesting, and IoT platforms enables automated dimming and energy savings.
Automotive and Transportation
Exterior Lighting: Headlights, fog lamps, and brake lights use high-power LED PCBs (e.g., 3–10W) with thermal vias and aluminum substrates for heat dissipation.
Interior Ambiance: RGBW LED strips and dome lights with PWM dimming create customizable cabin environments.
EV Charging Stations: Weatherproof PCBs with conformal coatings (e.g., parylene) withstand outdoor conditions.
Industrial and Hazardous Environments
Explosion-Proof Fixtures: ATEX/IECEx-certified PCBs with hermetic seals and copper-core substrates operate in oil refineries or mining sites.
Machine Vision: High-CRI (>95) LED rings with uniform illumination aid quality control in assembly lines.
Cold Storage: PCBs rated for -40°C to 85°C with gold-plated traces resist corrosion in freezers.
Healthcare and Medical Devices
Surgical Lights: Shadowless LED arrays with 50,000+ lux output and color tuning (4000K–5000K) improve surgical precision.
Phototherapy: UV-A/UV-B LED PCBs with precise wavelength control (e.g., 365nm) treat skin conditions.
Diagnostic Tools: Endoscopes and dental curing lights use miniaturized PCBs (10mm×10mm) with fiber-optic coupling.
Outdoor and Street Lighting
Smart Poles: LED PCBs integrate LiDAR, cameras, and 5G antennas for traffic monitoring and Wi-Fi hotspots.
Solar-Powered Fixtures: Low-power PCBs with MPPT (maximum power point tracking) circuits optimize battery life.
Tunnel Lighting: High-lumen COB LEDs with adaptive brightness reduce glare and energy use.
Entertainment and Stage Lighting
Moving Heads: RGBW LED arrays with 16-bit dimming and DMX/RDM control create dynamic light shows.
Marine Navigation: Corrosion-resistant PCBs with conformal coatings endure saltwater environments.
Art and Interactive Installations
Kinetic Sculptures: Addressable LED strips with 24-bit color depth enable pixel-mapping animations.
Museums: Interactive floors with pressure-sensitive LED PCBs respond to visitor movement.
VR/AR: Micro LED arrays (<50µm pitch) power high-resolution headsets.
How to Optimize LED Lighting PCB Design to Reduce Assembly Cost?
Here are practical strategies to optimize LED Lighting PCB Assembly design for cost reduction while maintaining performance:
Simplify Component Selection: Use standardized, high-yield LED packages (e.g., 2835, 5050 SMD) and integrated driver ICs to minimize part counts. Avoid niche components that require manual soldering or special handling, reducing labor costs by up to 30%.
Adopt Design for Manufacturing (DFM) Rules: Align trace widths (≥0.2mm) and spacing (≥0.15mm) with automated SMT equipment capabilities. Larger solder pads (e.g., 0.6mm×0.6mm) improve pick-and-place accuracy, cutting rework rates by 25%.
Optimize Panel Utilization: Arrange multiple PCBs in a panel with shared edges and tooling holes. This increases material yield by 15–20% and reduces per-unit costs for small-batch orders.
Reduce Layer Counts: Use 2-layer PCBs with thermal vias for basic lighting instead of 4-layer boards. For high-power designs, employ aluminum-core substrates to eliminate the need for external heat sinks.
Streamline Power Distribution: Place decoupling capacitors close to LED drivers (≤5mm) to stabilize voltage and reduce EMI filtering components. This simplifies BOMs and lowers parts sourcing expenses.
Implement Panelized Testing: Design PCBs with shared test points for automated electrical testing (AET). This reduces inspection time by 40% compared to manual probing of individual boards.
Leverage Bulk Sourcing: Partner with manufacturers to procure LEDs, resistors, and connectors in bulk. Volume discounts can lower component costs by 5% for large projects.
Minimize Through-Hole Components: Replace axial resistors or electrolytic capacitors with SMT equivalents to enable fully automated assembly. This eliminates wave soldering steps and associated chemical costs.
Use Open-Source Design Tools: Adopt free PCB layout software for initial designs. Simulate thermal and electrical performance digitally to reduce prototype iterations.
Incorporate Design Reuse: Create modular PCB templates for common lighting formats (e.g., 12V round boards). Reusing 60–70% of the layout accelerates time-to-market and cuts engineering hours.
By integrating these tactics, LED Lighting PCB assembly projects can achieve around 20–35% cost savings without compromising quality, scalability, or regulatory compliance.
How Are LED lighting PCB Assembled?
Here are assembly process of LED Lighting PCB:
Here’s a detailed, step-by-step breakdown of the LED Lighting PCB Assembly process, focusing on technical workflow and execution:
1. Material Preparation and Pre-Assembly Inspection
Engineers inspect PCB substrates (e.g., FR-4, aluminum-core), LED components, and surface-mount technology (SMT) parts for defects, compatibility, and alignment with design specifications.
Components are organized into tape-and-reel feeders or trays for automated assembly.
2. Solder Paste Application
A precision stainless-steel stencil is placed over the PCB.
Automated stencil printers deposit solder paste onto exposed pads using a squeegee blade, ensuring uniform coverage for component attachment.
Order a small batch to validate assembly quality, lead times, and communication efficiency.
Monitor post-assembly performance (e.g., LED luminous decay, solder joint integrity) under real-world conditions.
Review Intellectual Property Protections
Confirm NDAs, non-compete clauses, and data security measures (e.g., encrypted file sharing, access controls).
Check for patent compliance procedures to avoid legal risks.
Analyze Communication and Project Management
Evaluate transparency in reporting (e.g., daily production updates, yield metrics).
Test multilingual support and timezone alignment for global projects.
Probe Post-Production Services
Inquire about warranty terms (e.g., 2–5 years for LED assemblies), repair logistics, and end-of-life recycling programs.
Confirm support for product iterations or redesigns.
How Long Does it Take to Deliver 1 Piece Sample?
The delivery time for a single LED lighting PCB assembly sample typically ranges from 2 to 8 days, depending on several factors. Below is a detailed breakdown:
Standard Delivery Time (5–8 Days)
Most manufacturers follow a structured workflow:
Day 1–2: Material preparation, solder paste stenciling, and automated SMT placement.
Day 3–4: Reflow soldering, AOI inspection, and selective wave soldering (if needed).
Day 5–6: Functional testing, conformal coating, and final assembly.
Day 7–8: Quality control checks and packaging for shipping.
Expedited Delivery (24–48 Hours)
For urgent requests:
24-Hour Rush: Skip non-critical steps (e.g., selective wave soldering) and prioritize SMT placement and reflow.
48-Hour Turnaround: Include basic functional testing but omit accelerated aging tests.
Example: Some factories in Shenzhen (China) like Best Technology advertise 24-hour dispatch for simple designs, though this may exclude advanced coatings.
Opt for Standard Specs: Use commonly stocked materials (e.g., FR-4 substrates, 0805/0603 components).
Local Manufacturers: Choose a regional supplier to minimize shipping time (e.g., 1–2 days for domestic delivery).
Hidden Delays to Avoid
Design Errors: Revisions after production starts can add 3–5 days.
Component Shortages: Obsolete or niche parts (e.g., specific LED wavelengths) may delay orders by 7–10 days.
Peak Seasons: Chinese holidays (e.g., Chinese New Year) can extend lead times by 2–4 weeks.
What Factors Affect LED Lighting PCB Assembly Manufacturing Cost?
The manufacturing cost of LED lighting PCB assembly is influenced by a combination of material, process, and logistical factors. Below is a prioritized breakdown of main cost drivers:
Material Costs (30–50% of Total Expense)
PCB Substrates: Aluminum-core boards (for thermal management) cost 20–30% more than standard FR-4 materials.
LED Components: High-power LEDs (e.g., 3W+) or specialty wavelengths (e.g., UV, IR) increase costs by 15–40%.
Passive Components: Precision resistors (±1% tolerance) or automotive-grade capacitors add 5–10% to BOM costs.
Design Complexity (15–25% Impact)
Layer Count: 4-layer PCBs cost 30–50% more than 2-layer boards due to additional lamination and drilling steps.
Tg meaning，Tg has different meanings in different fields. The specific meaning needs to be judged in context. In professional fields, the full name is preferred. The following are common explanations:
Tg (Glass Transition Temperature) indicates the critical temperature point at which the PCB board changes from the hard and brittle “glass state” to the soft and tough “high elastic state”. The higher the Tg value, the stronger the PCB’s ability to resist deformation and stability at high temperatures, and the improved reliability.
Medical field (Triglycerides) As a blood lipid detection indicator, TG indicates the level of triglycerides in the blood. The normal range is 0.56-1.7 mmol/L. Abnormal values may cause cardiovascular disease or pancreatitis, which needs to be adjusted through diet and exercise.
Aerospace field: Tiangong space station code name, China’s manned space station is named “Tiangong”, code name TG, including core module and experimental module modules.
Country/region code: tg meaning
Thailand abbreviation: TG can refer to Thailand (Thailand), such as the IATA code of Thai Airways International is TG.
Game terminology: tg meaning
For example, “Tank” in “World of Warcraft” Gear” (tank equipment) Material Science: tg meaning Abbreviation for Thermogravimetry
In French online lingo, TG is the abbreviation for “Ta gueule”, which literally means “shut up”, with a strong tone of impatience or aggression, and is often used in informal chat scenarios
In mathematics, tg is the abbreviation for “tangente”, which represents the tangent function (such as tg θ represents the tangent value of angle θ)
TG meaning app
TG meaning app Mainstream meaning : In application scenarios, TG mainly refers to Telegram communication software (social scenarios) and TGpay wallet (cryptocurrency scenarios)
Possible abbreviations and meanings In TikTok, the specific meaning of TG needs to be judged in combination with the specific context. The following are common explanations: Transgender (transgender) : In In LGBTQ+ related topics, TG may refer to transgender people and is used in content or community tags that support gender diversity (such as #TG or #Transgender)1. Thank God: As a colloquial expression, TG can mean “Thank God” or “It’s finally over” (similar to TGI Friday in English), and is common in light-hearted and funny or complaining videos3. Specific challenges or memes: It may be associated with a localized tag or user-created abbreviation that is not widely spread (need to be judged in combination with the video content).
Ambiguity to be noted Telegram (TG): If the video content involves anonymous communities, file sharing or encrypted communications, it may refer to the social software Telegram, which has nothing to do with TikTok2. Other language meanings: In French content, TG may be a vulgar expression ”Ta gueule” (shut up), so use it with caution.
LED switching power supply PCB board design,In the design of switching power supplies, if the PCB board is not designed properly, it will radiate too much electromagnetic interference. The following seven tricks are summarized for the design of PCB boards that ensure stable power supply operation: by analyzing the matters that need to be paid attention to in each step, you can easily design the PCB board step by step!
Parameter setting: The spacing between adjacent wires must meet the electrical safety requirements, and the spacing should be as wide as possible for easy operation and production. The spacing should at least be suitable for the voltage to be tolerated. When the wiring density is low, the spacing between signal lines can be appropriately increased. The signal lines with high and low levels should be as short as possible and the spacing should be increased. In general, the wiring spacing is set to 8mil. The distance from the edge of the inner hole of the pad to the edge of the printed circuit board should be greater than 1mm to avoid pad defects during processing. When the trace connected to the pad is thin, the connection between the pad and the trace should be designed into a water drop shape. The advantage of this is that the pad is not easy to peel, but the trace and the pad are not easy to disconnect.
Step 3
Component layout practice has proved that even if the circuit schematic is designed correctly, improper printed circuit board design will have an adverse effect on the reliability of electronic equipment. For example, if two thin parallel lines on a printed circuit board are very close to each other, a delay in the signal waveform will be formed, and reflected noise will be formed at the end of the transmission line; interference caused by inconsiderate consideration of the power supply and ground line will reduce the performance of the product. Therefore, when designing a printed circuit board, you should pay attention to using the correct method. Each switching power supply has four current loops: (1) Power switch AC loop (2) Output rectifier AC loop (3) Input signal source current loop (4) Output load current loop The input loop charges the input capacitor through a current that is close to DC, and the filter capacitor mainly plays a broadband energy storage role; similarly, the output filter capacitor is also used to store high-frequency energy from the output rectifier and eliminate the DC energy of the output load loop. Therefore, the terminals of the input and output filter capacitors are very important. The input and output current loops should be connected to the power supply only from the terminals of the filter capacitors; if the connection between the input/output loop and the power switch/rectifier loop cannot be directly connected to the terminals of the capacitor, the AC energy will be radiated from the input or output filter capacitor to the environment. The AC circuit of the power switch and the AC circuit of the rectifier contain high-amplitude trapezoidal currents. The harmonic components in these currents are very high, and their frequencies are much higher than the switching base frequency. The peak amplitude can be as high as 5 times the continuous input/output DC current amplitude, and the transition time is usually about 50ns. These two circuits are prone to electromagnetic interference, so these AC circuits must be laid out before other printed wiring in the power supply. The three main components of each circuit, filter capacitors, power switches or rectifiers, and inductors or transformers, should be placed adjacent to each other, and the positions of the components should be adjusted to make the current path between them as short as possible. The method of establishing the layout of the switching power supply is similar to its electrical design. The design process is as follows: Place the transformer Design the power switch current loop Design the output rectifier current loop Control circuit connected to the AC power circuit Design the input current source loop and input filter Design the output load loop and output filter According to the functional units of the circuit, when laying out all the components of the circuit, the following principles must be met: (1) First, consider the size of the PCB. When the PCB size is too large, the printed lines are long, the impedance increases, the anti-noise ability decreases, and the cost increases; if it is too small, the heat dissipation is poor, and the adjacent lines are susceptible to interference. The shape of the circuit board is rectangular, with an aspect ratio of 3:2 or 4:3. The components located at the edge of the circuit board are generally not less than 2mm away from the edge of the circuit board. (2) When placing components, consider the subsequent welding and do not place them too densely; (3) The components of each functional circuit are centered and the layout is carried out around it. The components should be arranged evenly, neatly and compactly on the PCB. The leads and connections between the components should be minimized and shortened as much as possible, and the decoupling capacitor should be as close to the VCC of the device as possible. (4) For circuits working at high frequencies, the distribution parameters between components should be considered. Generally, the components of the circuit should be arranged in parallel as much as possible. This is not only beautiful, but also easy to assemble and solder, and easy to mass produce. (5) Arrange the positions of each functional circuit unit according to the circuit process, so that the layout is convenient for signal flow and the signal keeps the same direction as much as possible. (6) The first principle of layout is to ensure the wiring pass rate. When moving components, pay attention to the connection of flying wires and put the components with connection relationships together. (7) Reduce the loop area as much as possible to suppress the radiation interference of the switching power supply.
Step 4
Wiring The switching power supply contains high-frequency signals. Any trace on the PCB can act as an antenna. The length and width of the trace will affect its impedance and inductance, thereby affecting the frequency response. Even traces that pass DC signals can couple to RF signals from adjacent traces and cause circuit problems (even radiate interference signals again). Therefore, all traces that pass AC current should be designed to be as short and wide as possible, which means that all components connected to the traces and to other power lines must be placed very close. The length of the trace is proportional to the inductance and impedance it exhibits, while the width is inversely proportional to the inductance and impedance of the trace. The length reflects the wavelength of the trace response. The longer the length, the lower the frequency of the electromagnetic wave that the trace can send and receive, and it can radiate more RF energy. According to the size of the printed circuit board current, try to increase the width of the power line and reduce the loop resistance. At the same time, make the direction of the power line and ground line consistent with the direction of the current, which helps to enhance the anti-noise ability. Grounding is the bottom branch of the four current loops of the switching power supply. It plays an important role as a common reference point of the circuit. It is an important method to control interference. Therefore, the placement of the grounding wire should be carefully considered in the layout. Mixing various groundings will cause unstable power supply operation. The following points should be noted in the grounding design:
Correctly select single-point grounding. Usually, the common end of the filter capacitor should be the connection point where other grounding points are coupled to the AC ground of large current. The grounding points of the same circuit should be as close as possible, and the power filter capacitor of the circuit at this level should also be connected to the grounding point of this level. The main consideration is that the current flowing back to the ground from each part of the circuit is changing. The impedance of the actual flowing line will cause the ground potential of each part of the circuit to change and introduce interference. In this switching power supply, the inductance between its wiring and devices has little effect, while the loop current formed by the grounding circuit has a greater impact on interference. Therefore, a single-point grounding is used, that is, the ground wires of several devices in the power switch current loop are connected to the ground pin, and the ground wires of several devices in the output rectifier current loop are also connected to the ground pin of the corresponding filter capacitor. In this way, the power supply works more stably and is not easy to self-excite. When a single point cannot be achieved, two diodes or a small resistor are connected to the common ground. In fact, it can be connected to a relatively concentrated piece of copper foil.
Try to thicken the ground wire. If the ground wire is very thin, the ground potential changes with the change of current, causing the timing signal level of the electronic equipment to be unstable and the anti-noise performance to deteriorate. Therefore, it is necessary to ensure that each large current ground end uses a printed line as short and wide as possible, and try to widen the width of the power and ground wires. The ground wire is wider than the power line. Their relationship is: ground wire>power line>signal line. If possible, the width of the ground wire should be greater than 3mm, or a large copper layer can be used as a ground wire. On the printed circuit board, all unused areas are connected to the ground as ground wires. When performing global wiring, the following principles must be followed: (1) Wiring direction: From the welding surface, the arrangement of components should be kept consistent with the schematic diagram as much as possible, and the wiring direction should be consistent with the wiring direction of the circuit diagram. Because various parameters usually need to be tested on the welding surface during the production process, this is convenient for inspection, debugging and maintenance during production (Note: It refers to the premise of meeting the circuit performance and the requirements of the whole machine installation and panel layout). (2) When designing the wiring diagram, the wiring should have as few turns as possible, the line width on the printed arc should not change suddenly, the wire corner should be ≥90 degrees, and the lines should be simple and clear. (3) No cross circuits are allowed in the printed circuit. For lines that may cross, “drilling” and “winding” can be used to solve them. That is, let a lead “drill” from the gap under the feet of other resistors, capacitors, and transistors In the past, or from one end of a lead that may cross, in special cases, if the circuit is very complicated, in order to simplify the design, it is also allowed to use wire jumper to solve the problem of cross circuit. Because a single-sided board is used, the through-hole components are located on the top surface and the surface-mount components are located on the bottom surface, so when laying out, the through-hole components can overlap with the surface-mount components, but the pads must be avoided from overlapping.
Input ground and output ground This switching power supply is a low-voltage DC-DC. To feed the output voltage back to the primary of the transformer, the circuits on both sides should have a common reference ground, so after the ground wires on both sides are coppered separately, they must be connected together to form a common ground.
Step 5
Inspection: After the wiring design is completed, it is necessary to carefully check whether the wiring design conforms to the rules set by the designer. At the same time, it is also necessary to confirm whether the rules set meet the requirements of the printed circuit board production process. Generally, check whether the distance between lines, lines and component pads, lines and through holes, component pads and through holes, and through holes are reasonable and meet production requirements. Whether the width of the power line and the ground line is appropriate, and whether there is any place in the PCB that can widen the ground line. Note: Some errors can be ignored. For example, part of the outline of some connectors is placed outside the board frame, which will cause errors when checking the spacing; in addition, after each modification of the routing and vias, copper must be re-coated.
Step 6
Review According to the “PCB Checklist”, the content includes design rules, layer definition, line width, spacing, pads, and via settings. It is also necessary to focus on reviewing the rationality of the device layout, the routing of the power and ground network, the routing and shielding of the high-speed clock network, and the placement and connection of the decoupling capacitors.
Step 7
a. The layers that need to be output are the wiring layer (bottom layer), the silk screen layer (including the top silk screen and the bottom silk screen), the solder mask layer (bottom solder mask), the drilling layer (bottom layer), and the drilling file (NCDrill) b. When setting the layer of the silk screen layer, do not select PartType, select the Outline, Text, and Line of the top (bottom) and silk screen layers c. When setting the layer of each layer, select Board Outline, and when setting the layer of the silk screen layer, do not select PartType, select the Outline, Text, and Line of the top (bottom) and silk screen layers. d. When generating the drilling file, use the default settings of PowerPCB and do not make any changes.
In PCB design, you’ll often notice rows of small holes along the edges of PCB panels. These holes, which looks like bit by a mouse, are commonly referred to as mouse bites PCB. They are also known as stamped vias or stamp holes due to their resemblance to the perforations found on postage stamps. These holes play a crucial role in securing components and establishing connections within the PCB, particularly during the breakaway process, where multiple PCBs are separated from a larger panel.
What is Mouse Bite in PCB?
What is mouse bites PCB? In the PCB world, a mouse bite refers to a small hole or notch created at the edges of the PCB panel. These notches are used to facilitate the separation of individual boards from the panel. The term “mouse bite” comes from the small, round shape of the indentation, resembling a tiny “bite” taken out of the PCB. The notches are typically placed along the edges of the PCB during the manufacturing process and are especially useful in high-volume production, where multiple PCBs are often manufactured as part of a larger panel.
Purpose of PCB Mouse Bites
The primary purpose of mouse bites in PCB design is to assist in the breakaway process. During the manufacturing of PCBs, multiple boards are often produced in a single panel. After fabrication, these panels must be separated into individual PCBs. Without a proper method, separating them could result in damage to the boards or pose a risk to delicate components.
Mouse bites are engineered to provide a controlled, predictable break. When the panel is ready for separation, the notches help to guide the break and reduce the chance of fractures or warping. Additionally, mouse bites are essential in panels where the PCBs are tightly packed, ensuring the separation process remains smooth and efficient.
Advantages of Mouse Bite in PCB
There are several notable advantages to using mouse bites in PCB design:
Controlled Separation: Mouse bites provide a controlled break, minimizing the risk of damaging the PCB during the separation process. They guide the break and ensure that it occurs where it’s most needed.
Improved Efficiency: Adding mouse bites to a PCB panel significantly speeds up the manufacturing process. This allows for quicker breakaway times, resulting in more efficient production cycles.
Cost-Effective: By reducing the likelihood of breakage or errors, mouse bites save money on rework, damaged boards, or production delays.
Design Flexibility: Mouse bites are particularly beneficial when manufacturing smaller PCBs within a larger panel. They offer design flexibility without compromising the integrity of the individual boards.
How Do You Add Mouse Bites to PCB?
Adding mouse bites to a PCB design is typically done in the design phase. The process involves creating small circular notches along the edges of the PCB. These notches are strategically placed where separation is intended.
To add mouse bites in PCB design software, follow these steps. Here’s a step-by-step guide on how to place mouse bites in Altium Designer:
1. Open Your PCB Project
Start Altium Designer and open the PCB project that you’re working on.
2. Create or Edit the PCB Panel
If you’re working with a multi-board panel, go to Design > Define Board Shape to create or edit the panel where you want to add the mouse bites.
3. Set Up the Mouse Bite Tool
In Altium Designer, go to the Tools menu and select Create Polygon Pour. This tool can be used to make the necessary notches (mouse bites) along the edges of the PCB.
4. Select the Edge of the PCB
With the polygon pour tool activated, click along the edge of the PCB where you want the mouse bites to appear.
5. Define the Hole Parameters
Define the size and shape of the mouse bite by adjusting the hole diameter and spacing. Mouse bites are typically circular, and you can customize the hole size to fit your design requirements (e.g., 0.3mm to 1.2mm).
6. Place the Mouse Bites
Position the mouse bites along the edges of the panel. Make sure the notches are evenly spaced and aligned according to your design rules.
7. Ensure Proper Clearance
Verify that there is enough clearance from the PCB edges (at least 0.3mm) to avoid damage or cracking during separation.
8. Check the Design Rules
Review your Design Rules to ensure the mouse bites meet the necessary standards for the board’s separation and manufacturing process.
9. Save the Design
Once you’re satisfied with the placement and spacing, save your design.
10. Export the Files
After placing the mouse bites, export your Gerber files for manufacturing by going to File > Fabrication Outputs and selecting the appropriate output format.
By following these steps, you can efficiently place mouse bites in your PCB design using Altium Designer. If you are not familiar with Altium software, you are welcome to contact Best Technology team, we offer free technical support for our customers.
What Is the Difference Between V-Groove and Mouse Bites?
Both V-groove and mouse bites are methods used to separate PCBs after fabrication, but there are some key differences between the two:
V-Groove
V-grooves are deeper cuts, often formed by a mechanical process that creates a “V” shape along the edge of the PCB. This type of break is typically used for larger panels and requires additional precision during manufacturing.
Pros: High precision, smooth cutting surface, suitable for automated production, and aesthetically pleasing. It is ideal for applications with strict precision requirements.
Cons: The edge strength is relatively low, making it unsuitable for applications that need to endure high mechanical stress. For PCBs with more than a certain number of layers, controlling the V-groove depth becomes more challenging, potentially affecting product quality.
Mouse Bites
Mouse bites are used as a method for inter-layer connections within multi-layer PCBs, especially in high-density interconnect (HDI) designs. Small, deep holes are drilled between the layers of the PCB, and copper is plated on the hole walls to create electrical connections between layers.
Pros: High space utilization, especially suitable for compact designs. It improves signal transmission performance by reducing signal delay and cross-talk. It is suitable for more complex multi-layer board designs.
Cons: The manufacturing process is complex and costly. It requires high precision in design and testing, increasing development difficulty.
Tips for Selecting the Right PCB Breakaway Method
Choosing the correct breakaway method is crucial for ensuring your PCBs are separated cleanly and efficiently. Here are some tips to consider:
Panel Size: Larger panels may benefit from V-grooves, while smaller or more delicate boards are better suited for mouse bites.
Design Considerations: If your design has sensitive components near the edge, mouse bites may be a better option since they cause less stress to the board during separation.
Cost and Efficiency: Mouse bites are typically more cost-effective for smaller runs, while V-grooves may be better for high-volume production.
Design Guide for Mouse Bites PCB
The design rules for mouse bites are critical for ensuring the reliability and stability of the PCB. Below are the requirements for the design rules of stamped holes in PCBs:
1. Hole Diameter: The diameter of the mouse bites should be selected based on the design requirements and the connected components. Typically, common hole sizes range from 0.3mm to 1.2mm.
2. Edge Clearance: To ensure that the hole has enough distance from the PCB edge and avoid cracking or peeling, the design rules require a minimum clearance of 0.3mm from the edge.
3. Hole Layout: The layout of the holes in PCB design is crucial. Holes should be distributed more concentrically and evenly across the PCB to avoid overcrowding, ensuring the stability and reliability of connections.
4. Hole Reinforcement: Certain components, such as resistors and capacitors, may loosen due to mechanical shock or vibration. To increase stability, design rules require the presence of pads or filling rings around the mouse bites hole to enhance the connection’s sturdiness.
5. Pad Size: To ensure welding quality and reliability, the mouse bites should be paired with a sufficiently large pad. The pad’s diameter is generally at least twice the hole size, ensuring ample space during the soldering process.
6. Trace Routing: To maintain the electrical performance and stability of the mouse bites, traces should avoid passing directly through the hole whenever possible. If traces must pass through the hole, they should not intersect with pins, and dead zones should be avoided.
7. Trace Spacing: To prevent interference between traces and avoid soldering errors, the design rules require sufficient trace spacing between stamped holes.
FAQs
Q1: Can I use mouse bites in all PCB designs?
Yes, mouse bites are ideal for most PCB designs that need to be separated after manufacturing. However, they are best suited for smaller boards or those with less sensitive components along the edges.
Q2: How do I avoid damaging my PCB during the separation process?
By using mouse bites or V-grooves, you can reduce the risk of damaging your PCB. Properly designed notches ensure a controlled break, which minimizes the risk of cracks or fractures.
Q3: Are mouse bites more cost-effective than V-grooves?
Yes, mouse bites are generally more affordable than V-grooves, especially for smaller production runs.
Q4: Can mouse bites be placed on the entire PCB edge?
Yes, mouse bites can be placed along the entire edge of the PCB, but it’s important to leave enough margin from the board’s edge to prevent cracks or damage.
Q5: How do mouse bites differ from traditional breakaway tabs?
Mouse bites create small perforations that guide the break along the PCB’s edge, while traditional breakaway tabs usually involve larger cuts or slots. Mouse bites provide more precise separation with less risk of board damage.
If you’ve ever taken a close look at a printed circuit board (PCB), you might have noticed small text, symbols, and lines on the surface. These aren’t just for decoration — they make up the PCB’s silkscreen layer, which plays a key role in making the board readable and easy to assemble. Think of silkscreen as a guiding map that helps technicians identify components and connections quickly. From component labels to polarity indicators, this layer is a simple yet invaluable part of any well-designed PCB. Let’s dive into what silkscreening is, why it’s so useful, and what you need to know about its colors, materials, and application methods.
What is a Silkscreen on a PCB?
Silkscreen is a layer of ink applied to the PCB’s surface. Typically, you’ll find it on the top side, although it can also be placed on the bottom. Screen silkscreen is usually used to indicate useful information on the PCB board, which can help the user in the assembly process, and is used to mark the component value, part number, polarity and other information, but also contains the version, manufacturer and other information. You’ll often see labels, symbols, and small icons that guide people assembling or repairing the board. In a busy PCB layout, the silkscreen is a roadmap for where everything goes, helping avoid mix-ups and reducing assembly time.
What is the Purpose of Silkscreen?
The silkscreen layer’s primary purpose is to add clarity. By showing clear labels for components, it reduces the chance of error during assembly. When it’s time to troubleshoot, silkscreen also makes life easier by letting technicians locate parts quickly. Silkscreen may include warnings, brand logos, or model names, all helping to make the board more informative. Essentially, it saves time, improves accuracy, and simplifies the process from start to finish.
Silkscreen Information Include on PCB
Silkscreen can be letters, numbers, text. PCB screen printing is done during the PCB manufacturing process, but is used for the PCB assembly process step. Here are some common information that can be silkscreened.
1. Polarity reference sign
2. Determine the test point
3. Component bit number reference mark
4. Component boundary
5, component pin mark
6. Unique identification number for each board
7. Company logo
8. Version number
9. Date code
10, Manufacturer’s logo, serial number, lot number
11. Warning symbols
12. Regulatory marks
Regulatory marks are used to indicate that a design has passed inspection or complies with specific regulations. RoHS, FCC, CE and e-waste disposal marks are commonly found on consumer and commercial products that have passed relevant inspections.
If another mark is seen on a design that has been inspected for safety: the UL mark, this mark indicates that the design was manufactured and assembled by a UL-certified manufacturer according to the UL796 and UL94 standards.
What are the Colors of PCB Silkscreen?
The color of silkscreen is chosen based on readability. White is the most common choice, especially on boards with a green soldermask, because it has a very good readability. And it is a public color and is more friendly to manufacture.
In addition, other colors such as yellow, red, black are also commonly used in the initial stage of PCB board design, pink screen printing is a favorite color of some PCB Layout, but it is usually not recommended to use this color, because it has special characteristics and is not friendly to the manufacturing process.
PCB Silkscreen Symbol
Silkscreen symbols represent various components on the board, making it easier to find specific parts and identify their functions. For instance, “R” stands for resistors, “C” for capacitors, and “U” for integrated circuits. Symbols also show component orientation and polarity, which is crucial for accuracy in assembly. Well-organized symbols on the silkscreen save time and effort, especially during maintenance, as they allow technicians to pinpoint components instantly.
What is the Difference Between Silkscreen and Solder Mask?
Solder mask is a green or other color layer coated on the circuit board, which can play a role in protecting the board. Because there are usually many wires and components on the surface of the circuit board, it is easy to have problems such as short circuit or virtual welding during the welding process, which will lead to damage to the circuit board. Solder resistance layer can effectively avoid the occurrence of this problem. At the same time, the solder resistance layer can also improve the corrosion resistance and mechanical strength of the circuit board.
Solder mask and silkscreen are both coated on the circuit board, but their roles are different. The solder resistance layer is mainly used to protect the circuit board from welding problems, and the screen printing is used to identify the components and related information on the circuit board. In addition, the solder mask is usually green or other bright colors, and the screen printing is usually white or other light colors for easy identification.
What is the Screen Printing Method of PCB?
There are totally three ways to print silkscreen on a PCB surface, manual screen printing, LPI, and DLP. Let me introduce them for you:
1. Manual screen printing
Do this on the PCB when the registration tolerance is 0.005 inches or the line width is greater than 0.007 inches. Perform manual screen printing using a mold containing text and traces. Traces are made of nylon. The ink is directed to the layer or laminate by stenciling. Next, the ink is cured in a baking oven. This is one of the easy ways to create a silk-screen layer, and it also supports large fonts. Perfecting the art can take years.
2. Liquid Photo Imaging (LPI):
This method is used to screen print threads larger than 4 million. The process of LPI is almost the same as the application of solder mask. In this method, however, the laminate is coated with epoxy resin and then placed under ultraviolet light. The plate is cured and then developed. This method ensures greater accuracy than manual screen printing.
LPI uses white, which requires more ink than the other two types of screen printing. Such prints take a long time to set up.
3. Direct Legend Printing (DLP):
This is one of the other three processes that is expensive. In this process, an inkjet projector and acrylic ink will be used. The ink is applied to the PCB using CAD software. The ink is then exposed to ultraviolet light. Acrylic links are not suitable for PCBS that may have a silver surface.
How Thick is the Silkscreen on a PCB?
Silkscreen thickness is usually about 0.02 mm. This thin layer is enough to make the markings visible without interfering with the board’s layout or operation. The thinness is key because it keeps the board easy to handle without any obstruction or interference, but it’s thick enough that it won’t wear off easily during normal use.
Best Technology highly specialized not only in quick-turn PCB prototype and PCB assembly, but also medium and small volume PCB fabrication. We can provide silkscreen on your PCBs for you with various colors, and we will try our best to meet the demands of silkscreen. If you have any questions, please feel free to contact us, we will be happy to help you.
Can you use AC in PCB?AC can be used in PCB boards. PCB boards are designed to support the use of AC, and the functions of AC can be realized through proper circuit design and component selection.
Can you use AC in PCB?
The use of AC in PCB boards requires consideration of the characteristics of AC. The current magnitude and direction of AC change continuously over time, which requires the components and layout on the PCB to adapt to such changes. For example, components such as inductors and capacitors play an important role in AC circuits, and their parameters and layout need to be carefully designed to achieve the desired circuit performance.
Specifically, AC circuit design on PCB boards includes selecting appropriate components, layout, and routing. For example, using test instruments such as LCR digital bridges can measure the parameters of components in AC circuits to ensure that the performance of the circuit meets the design requirements. In addition, reasonable ground routing and layout can reduce signal interference and ensure the stable transmission of AC.
Is the circuit board DC or AC?
Circuit boards can transmit both direct current and alternating current. In modern electronic products, we use alternating current for power supply, so most circuit boards are also designed to transmit alternating current. Of course, in some special application scenarios, some circuit boards also need to transmit direct current. Whether transmitting direct current or alternating current, the circuit board needs to meet the requirements of the transmitted current.
What is the PCB in AC?
The alternating current in PCB refers to the current whose direction changes periodically, that is, alternating current (AC). The application of alternating current in PCB is mainly reflected in power conversion and power transmission. PCB power supply usually converts AC into stable direct current (DC) output to meet the demand of electronic equipment for stable power supply. PCB power supply converts AC into the required DC through components such as transformers, rectifiers, filters and voltage regulators, and provides stable power output.
How to calculate the bandwidth of AC in PCB traces
The calculation of AC PCB trace width can be performed by the following formula: W = (I / J) * K, where W represents the trace width, I represents the current, J represents the current density, and K represents a coefficient related to materials and processes. This formula shows that the trace width is related to the current, current density, and material properties.
AC in PCB Design Guide
Current Carrying Capacity: The width of a trace directly affects its ability to handle current without exceeding temperature limits or causing excessive voltage drop. Impedance Control: In high-frequency applications, maintaining controlled impedance is critical for signal integrity. Trace width, trace spacing, and dielectric properties affect the characteristic impedance of the transmission line. Heat Dissipation: Adequate trace width helps to effectively dissipate heat, preventing thermal issues such as trace delamination or solder joint failure. Voltage Drop: Narrower traces exhibit higher resistance, resulting in increased voltage drop along the length of the trace. By adjusting the trace width, the voltage drop can be minimized. Manufacturability: The PCB manufacturing process imposes restrictions on the minimum trace width, and designers must balance performance requirements with manufacturability constraints. 2. Minimum Trace Width: Most manufacturers have a minimum trace width of 6mil or 0.152mm, and typically use traces of 0.254-0.3mm. Material and Process Deviations: Due to the possibility of material and process deviations in the actual PCB manufacturing process, a certain margin needs to be left when calculating the line width. Signal Integrity Simulation: Perform signal integrity simulations to ensure impedance is controlled and signal degradation due to reflections, crosstalk, or transmission line effects is minimized
AC in PCB wiring
The current trend is that the power supply voltage is getting lower and lower (especially for highly integrated digital devices), the space occupied is getting smaller and smaller, the weight is getting lighter and lighter, and the efficiency is getting higher and higher, which requires the precise design of the power supply circuit starting from the PCB.
Safety distance includes electrical clearance (spatial distance), creepage distance (surface distance) and insulation penetration distance…
Electrical clearance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the air.
Creepage distance: the shortest distance between two adjacent conductors or one conductor and the adjacent motor housing surface measured along the insulation surface.
Determination of electrical clearance:
The distance can be determined according to the measured working voltage and insulation level
The electrical clearance size requirements of the primary side line are shown in Table 3 and Table 4
The electrical clearance size requirements of the secondary side line are shown in Table 5
But usually: Primary side AC part: L-N ≥ 2.5mm before the fuse, L.N PE (earth) ≥ 2.5mm, no requirements are made after the fuse is installed, but a certain distance should be maintained as much as possible to avoid short circuit damage to the power supply.
Primary side AC to DC part ≥2.0mm
Primary side DC ground to earth ≥2.5mm (primary side floating ground to earth)
Primary side to secondary side ≥4.0mm, components connected between primary and secondary sides
Secondary side gap ≥0.5mm
Secondary side ground to earth ≥1.0mm
Note: Before determining whether it meets the requirements, the internal parts should be applied with a force of 10N and the outer shell with a force of 30N to reduce the distance so that the space distance still meets the requirements under the worst case.
Determination of creepage distance:
Based on the working voltage and insulation level, the creepage distance can be determined by looking up Table 6
But usually: (1), primary side AC part: L-N ≥2.5mm before the fuse, L.N earth ≥2.5mm, no requirement is required after the fuse, but try to keep a certain distance to avoid short circuit damage to the power supply.
(2) Primary side AC to DC part ≥2.0mm
(3) Primary side DC ground to ground ≥4.0mm such as primary side ground to earth
(4) Primary side to secondary side ≥6.4mm, such as optocoupler, Y capacitor and other components, the foot spacing ≤6.4mm needs to be slotted.
(5) Secondary side parts ≥0.5mm
(6) Secondary side ground to earth ≥2.0mm or more
(7) Transformer two-stage ≥8.0mm or more
Insulation penetration distance:
It should meet the following requirements according to the working voltage and insulation application:
For working voltage not exceeding 50V (71V AC peak or DC value), there is no thickness requirement;
The minimum thickness of additional insulation should be 0.4mm;
When the reinforced insulation is not subjected to any mechanical stress that may cause deformation or performance degradation of the insulating material at normal temperature, the minimum thickness of the reinforced insulation should be 0.4mm. If the insulation provided is used in the protective casing of the equipment and will not be bumped or scratched during maintenance by the operator, and any of the following conditions apply, the above requirements do not apply to thin insulating materials regardless of their thickness;
For additional insulation, at least two layers of material are used, each of which can pass the dielectric strength test for additional insulation; or:
For additional insulation composed of three layers of material, any combination of two layers of material can pass the dielectric strength test for additional insulation; or:
For reinforced insulation, at least two layers of material are used, each of which can pass the dielectric strength test for reinforced insulation; or:
For reinforced insulation composed of three layers of insulating material, any combination of two layers of material can pass the dielectric strength test for reinforced insulation.
Points to note about wiring process:
Flat components such as capacitors must be flat without glue.
If the distance between two conductors can be shortened by applying a force of 10N, which is less than the safety distance requirement, glue can be used to fix the part to ensure its electrical clearance.
When laying PVC film inside some shell equipment, attention should be paid to ensuring the safety distance (pay attention to the processing technology).
When fixing the parts with glue, be careful not to leave foreign matter such as glue wire on the PCB board.
When processing parts, insulation damage should not be caused.
Requirements for flame-proof materials:
Heat shrink tubing V-1 or VTM-2 or above; PVC tubing V-1 or VTM-2 or above
Teflon tubing V-1 or VTM-2 or above; plastic materials such as silicone sheets, insulating tape V-1 or VTM-2 or above
PCB board 94V-1 or above
Regarding insulation level
(1) Working insulation: insulation required for normal operation of equipment
(2) Basic insulation: insulation that provides basic protection against electric shock
(3) Supplementary insulation: independent insulation applied in addition to basic insulation to protect against electric shock in case of basic insulation failure
(4) Double insulation: insulation consisting of basic insulation plus supplementary insulation
(5) Reinforced insulation: a single insulation structure that provides the same level of protection against electric shock as double insulation under the conditions specified in this standard
The applicable situations of various insulation are as follows:
A. Operational insulation
a. Between parts with different voltages
b. Between ELV circuits (or SELV circuits) and grounded conductive parts.
B. Basic insulation
a. Between parts with dangerous voltages and grounded conductive parts;
b. Between SELV circuits with dangerous voltages and grounding-dependent;
c. Between the primary power conductor and the grounded shield or the core of the main power transformer;
d. As part of double insulation.
C. Supplementary insulation.
a. Generally speaking, between accessible conductive parts and parts that may carry dangerous voltages after basic insulation is damaged, such as:
Ⅰ. Between the surface of handles, knobs, handles or similar objects and their ungrounded axis.
Ⅱ. Between the metal casing of the second category equipment and the outer skin of the power cord passing through this casing.
Ⅲ. Between the ELV circuit and the ungrounded metal casing.
b. As part of double insulation
D. Double insulation
Double insulation Reinforced insulation
Generally speaking, between the primary circuit and
a. between accessible ungrounded conductive parts, or
Under normal working conditions, the AC peak value between conductors or between any conductors does not exceed 42.4V or the DC value does not exceed 60V.
SELV circuit: safety extra low voltage circuit.
A properly designed and protected secondary circuit so that under normal conditions or single fault conditions, the voltage between any two accessible parts, and between any accessible parts and the protective grounding terminal of the equipment (only for Class I equipment) will not exceed the safety value.
TNV: communication network voltage circuit
Under normal working conditions, the circuit carrying communication signals
Difference between direct current and alternating current
The main differences between DC and AC include direction and polarity, voltage change, current loss, transformer use, and application scenarios.
Direction and polarity:
DC: The direction of the current remains unchanged, and the electrons flow from the positive electrode to the negative electrode.
AC: The direction of the current changes periodically, and the electrons flow back and forth between the positive and negative electrodes. Voltage change:
DC: The voltage remains constant and does not change over time.
AC: The voltage magnitude and direction change periodically over time. For example, the mains is an AC with a sine waveform.
Current loss:
DC: Fault losses are relatively small.
AC: There is capacitive current, and there is capacitive current in the transmission line. Transformer use:
DC: The voltage cannot be changed using a transformer.
AC: The voltage can be changed using a transformer, which is suitable for boosting voltage to reduce losses during long-distance transportation.
Application scenarios:
DC: Suitable for low-voltage electrical appliances and occasions that require stable current. Alternating current: Suitable for household and industrial use, using transformers to change voltage to suit different needs.
FAQ About AC in PCB
FAQ About AC in PCB
Q: The relationship between PCB current and line width. Is the current divided into AC or DC? A: The relationship between PCB current and line width is not divided into AC or DC. In terms of the nature of the lines on the PCB, the lines are all made of copper materials, and both AC and DC can pass. However, how much current can pass depends on the cross-sectional area of the line on your PCB. That is, line width x thickness of the copper foil of the line. If the cross-sectional area of the line is small, only small current signals can pass, and if the cross-sectional area is large, large current signals can pass. This signal can be AC or DC. Not just 1mm, any line width can pass DC or AC signals.
Q: There is a packaged device, and there are 2 pins in the device that need to be connected to the live wire and neutral wire of 220V AC respectively. So how to deal with this power line when drawing the PCB? Are there any size requirements for pads, wires, etc.? Are there any protective measures required? Is it not possible to directly add pads to connect to the pin pads of the device? A: It is best to mill a groove between the neutral wire and the live wire, and choose the thickness of the wire according to the current. When the current is large, you can put a tin layer on the wire, and the pad should be slightly larger.
Q: The grounding of the PCB circuit board design is also the negative pole. What is the difference between the grounding here and the AC grounding?
A: The concept of the circuit board ground is somewhat different from that of the power supply system. The power supply system refers to the earth, that is, the terminal with the same potential as the earth.
The ground in the circuit board is just a common terminal of a potential, which can be positive or negative, depending on the needs of the designer. It’s just that everyone is used to and assumes that the negative pole is the common terminal, that is, the ground. The circuit board ground is not necessarily connected to the earth.
But it must be connected to the earth when EMI filtering is required.
Q: Should all GNDs on the PCB board be connected? There is a terminal (screw type) with two terminals marked as V1+ and V1- on the PCB schematic. Should V1- be connected to the power supply ground? But I used a multimeter to measure why V3- is not connected to other GNDs on the board?
So how do you connect the ground and 10V of the power supply to the V1+ and V1- ends of the terminal?
A: Not all ground wires on the board are connected together. The ground wires are divided into analog ground and digital ground, just like the ground wire in DC and the ground wire in AC cannot be connected together. That is to say, there is a ground wire that is specifically used for power supply, and there is a ground wire that is specifically used for signals (shielding signal interference). These two ground wires cannot be connected together. In addition, you mentioned V1+ and V1-, and V1- should not be considered a ground wire. Generally, the signal represented by this method is a differential signal, that is, the V1 signal is differentially divided into V1+ and V1-, which can reduce external interference and transmit farther. Finally, V1+ and V1- are integrated into the V1 signal. You need to figure out whether the V1+ and V1- of the terminal are used for power supply. If they are used for power supply, then V1+ is the positive pole. V1- is the negative pole. Since you didn’t show us the picture, you can’t just connect it randomly. The circuit board needs to connect not only power but also signals, depending on how your board is made.
Board electronics with holes The types of vias in PCB include through holes, blind holes and buried holes, which have different characteristics and requirements in design and manufacturing. The selection of the appropriate via type should consider the number of PCB layers, wiring density, signal frequency, cost budget and production process. The via design should pay attention to avoid affecting the welding quality, preventing electrical short circuits, and saving costs in high-density packaging.
What are the holes in a PCB called?
What are the holes on PCB called? What are the holes in the circuit? The holes on PCB can be roughly divided into 3 types, screw holes (mounting holes), conductive holes (vias), and plug-in holes.
Screw holes: Screw holes are used for fixing.
Conductive holes: Conductive holes (also called vias) are used for conducting electricity just like circuits.
Plug-in holes: Plug-in holes are of course used to plug in various parts, such as diodes, transistors, capacitors, inductors, etc.
What is a through hole
What is a through hole? Through holes, also known as perforations, are holes in a PCB that go all the way through the board. Their main purpose is to provide electrical connections for component pins while allowing soldering on both sides of the board.
1.A via is a special through hole whose wall is metallized to achieve electrical connection between different layers on a circuit board. This type of hole is usually used to connect component pins to internal circuits, or to achieve electrical connection between different layers in a multi-layer PCB. Vias need to be metallized during the PCB manufacturing process, which usually includes drilling, desmearing, chemical copper plating, and electroplating.
2.Non-conducting holes are the opposite of through holes. Their hole walls are not metallized, so they do not have electrical connection functions. These holes are mainly used for mechanical fixation, heat dissipation or identification purposes. Non-conducting holes are relatively simple in the PCB manufacturing process, and only drilling operations are required.
What is a blind via?
A blind via is a hole that extends from one side of a PCB to a certain internal layer without penetrating the entire board. The emergence of blind vias is mainly due to the development of HDI technology, which provides circuit designers with greater flexibility and more compact layout. Blind vias are usually used to connect surface mount components (SMD) to internal circuit layers, or to connect circuits between different internal layers.
What are buried vias?
Buried vias are holes located inside the PCB that do not penetrate any side of the board. They are completely hidden inside the board and are used to connect circuits between different internal layers. Buried vias are especially useful in HDI boards because they can reduce the overall thickness of the board while maintaining electrical connections between internal circuits.
What is a microvia?
Microvia refers to a hole with a smaller diameter, usually at the micron level. The emergence of microvia technology enables PCB designers to achieve more complex circuit layouts in a smaller space. Microvias are often used in high-density, high-reliability electronic devices such as mobile phones and tablets. The manufacture of microvias requires high-precision drilling equipment and technology to ensure the accuracy and reliability of the holes.
What are Mounting holes？
What are Mounting holes?Locking holes are auxiliary holes used in the PCB manufacturing and assembly process to accurately locate and fix the circuit board. They are usually located at the edge or specific position of the PCB to ensure that the circuit board can be accurately aligned and fixed during manufacturing, testing and assembly. The locating holes do not participate in the connection of the circuit, but are essential to ensure the quality and performance of the circuit board.
What are Mounting holes？
What are thermal vias?
Thermal vias are holes designed specifically for heat dissipation, usually large and can run through the entire PCB or multiple layers. Their role is to reduce heat buildup on the circuit board by increasing surface area and air flow, thereby improving the stability and reliability of the device. Thermal vias are particularly important in high-performance, high-power electronic devices.
FAQ About board electronics with holes
How to solve the contradiction between manual routing and automatic routing of high-speed signals?
Most of the current powerful routing software’s automatic routing tools have set constraints to control the routing method and the number of vias. The routing engine capabilities and constraint setting items of various EDA companies are sometimes very different. For example, whether there are enough constraints to control the winding method of the serpentine, whether the routing spacing of the differential pair can be controlled, etc. This will affect whether the routing method generated by automatic routing can meet the designer’s ideas. In addition, the difficulty of manually adjusting the routing is also related to the capabilities of the routing engine. For example, the pushing ability of the routing, the pushing ability of the via, and even the pushing ability of the routing pair copper. Therefore, choosing a routing tool with strong routing engine capabilities is the solution.
Will adding test points affect the quality of high-speed signals?
As for whether it will affect the signal quality, it depends on the method of adding test points and how fast the signal is. Basically, the additional test points (not using the existing vias (via or DIP pins) as test points) may be added to the line or a small section of wire may be pulled out from the line. The former is equivalent to adding a very small capacitor to the line, while the latter is an additional branch. Both of these situations will have some impact on high-speed signals, and the extent of the impact is related to the frequency speed of the signal and the edge rate of the signal. The magnitude of the impact can be learned through simulation. In principle, the smaller the test point, the better (of course, it must meet the requirements of the test equipment) and the shorter the branch, the better.
Can you introduce some foreign technical books and data on high-speed PCB design?
Now the application of high-speed digital circuits includes communication networks and calculators and other related fields. In the communication network, the operating frequency of PCB boards has reached around GHz, and the number of layers is as many as 40 layers as far as I know. Due to the advancement of chips, the operating frequency of calculator-related applications, whether it is a general PC or server, has reached 400MHz (such as Rambus) or above. In response to the demand for high-speed and high-density routing, the demand for blind/buried vias, mircrovias and build-up process technology is gradually increasing. These design requirements can be mass-produced by manufacturers.
Does the design of rigid-flexible boards require special design software and specifications? Where can I undertake the processing of such circuit boards in China?
Can I use general PCB design software to design flexible printed circuits (Flexible Printed Circuit). The Gerber format is also used for FPC manufacturers to produce. Since the manufacturing process is different from that of general PCBs, each manufacturer will have its own restrictions on line width, line spacing, and aperture (via) based on their manufacturing capabilities. In addition, some copper foil can be laid at the turning point of the flexible circuit board for reinforcement. As for the manufacturer, you can search for “FPC” as a keyword on the Internet and you should be able to find it.
If the size of the circuit board is fixed, if the design needs to accommodate more functions, it is often necessary to increase the routing density of the PCB, but this may lead to increased mutual interference between the routings, and at the same time, the impedance cannot be reduced if the routing is too thin. Please introduce the techniques in the design of high-speed (>100MHz) high-density PCBs?
When designing high-speed and high-density PCBs, crosstalk interference does need to be paid special attention to because it has a great impact on timing and signal integrity. Here are a few things to note:
Control the continuity and matching of the characteristic impedance of the trace.
The size of the trace spacing. The spacing commonly seen is twice the line width. Through simulation, you can know the impact of trace spacing on timing and signal integrity and find the tolerable spacing. The results of different chip signals may be different.
Choose an appropriate termination method.
Avoid the same routing direction of the upper and lower adjacent layers, or even have traces overlapped up and down, because this kind of crosstalk is greater than the case of adjacent traces on the same layer.
Use blind/buried vias to increase the trace area. However, the production cost of the PCB board will increase. It is indeed difficult to achieve complete parallelism and equal length in actual implementation, but it should be done as much as possible.
In addition, differential termination and common mode termination can be reserved to mitigate the impact on timing and signal integrity.
The RF part, IF part, and even the low-frequency circuit part of the outdoor unit are often deployed on the same PCB. What are the material requirements for such PCB? How to prevent interference between RF, IF, and even low-frequency circuits?
Hybrid circuit design is a big problem. It is difficult to have a perfect solution.
Generally, RF circuits are laid out and wired as an independent single board in the system, and there will even be a special shielding cavity. Moreover, RF circuits are generally single-sided or double-sided boards, and the circuits are relatively simple. All of these are to reduce the impact on the distributed parameters of RF circuits and improve the consistency of RF systems. Compared with general FR4 materials, RF circuit boards tend to use high-Q substrates. The dielectric constant of this material is relatively small, the distributed capacitance of the transmission line is small, the impedance is high, and the signal transmission delay is small. In hybrid circuit design, although RF and digital circuits are made on the same PCB, they are generally divided into RF circuit area and digital circuit area, and laid out and wired separately. Shielding is used between ground vias and shielding boxes.
What is pcba and its components?Refers to fixing electronic components on a printed circuit board by welding or other means to form a complete circuit system with specific functions. PCBA is one of the most important components in electronic devices, providing functions such as circuit connection, protection components and heat dissipation.
Best offers consignment, full turnkey, and partial turnkey assembly services. All parts are sourced directly from manufacturers or authorized distributors such as Digikey, Mouser, Future, TTI, Avnet, and Arrow to avoid counterfeit parts.
What is PCBA?
PCBA is the abbreviation of Printed Circuit Board Assembly, which refers to the process and product of installing and soldering all necessary electronic components on a PCB (printed circuit board) to form a complete functional circuit. PCBA is a key step in the production of electronic equipment. It provides a platform for electronic components to work in a coordinated manner, enabling the device to perform its intended tasks.
What is a PCBA component?
What is a PCBA component?
PCBA components refer to electronic components soldered on PCBs, including various components packaged in SMD patches and DIP plug-ins, such as integrated circuits IC, crystal oscillators, diodes, triodes, resistors, capacitors, transformers, digital tubes, connectors, inductors, etc. These components are the basis for realizing the hardware connection and program functions of PCBA boards. PCB designers will draw the corresponding circuit schematics according to the functions of the products and select appropriate components to realize the circuit functions.
PCBA process steps
PCBA process steps
The PCBA (Printed Circuit Board Assembly) assembly process mainly includes two processes: SMT (surface mount technology) and DIP (through-hole insertion technology). According to the size and type of electronic components, the assembly process can be divided into several common component assembly methods such as single-sided mounting, double-sided mounting, single-sided mixed mounting and double-sided mixed mounting.
Empty board loading: Arrange the PCB boards neatly, put them into the material rack, and send the PCB boards to the SMT production line through the automatic board loading machine.
2. Printing solder paste: Print solder paste on the pads on the PCB board where components need to be soldered to prepare for subsequent soldering.
3.Solder paste inspection: Check the quality of solder paste printing through optical instruments to ensure that there is no problem such as too much tin, too little tin or thick solder paste.
4.SMT: Use high-speed SMT machines and general-purpose SMT machines to attach electronic components to the PCB board. Small components use high-speed SMT machines, and large components use general-purpose SMT machines.
5.Reflow soldering: Melt the solder paste to solder the electronic components to the PCB board. Temperature control during the reflow soldering process is very important.
6. Cleaning and testing: Clean after soldering to remove excess solder and impurities, and then test to ensure that all components are correctly soldered.
PCB board inspection and acceptance standards
Appearance inspection: Check the dimensional accuracy, position accuracy, surface treatment and electrical safety of the PCBA board. The dimensional accuracy should meet the design requirements, such as aperture, line width, line spacing, etc. The position accuracy should be accurate and without deviation, such as component spacing, pad position, etc. The surface treatment should meet the requirements, such as whether there are scratches, oxidation, oil stains, cracks, depressions, discoloration, corrosion, etc. The electrical connection should be reliable, without short circuit or open circuit.
Acceptance conditions: The parts are damaged, but the body remains good, the internal metal components are not exposed, and the specifications are marked with text, and the polarity is identifiable. Although the IC is damaged, there is no cracking. There is no cracking between the IC foot and the body package. The part foot is not damaged. The part surface is tinned with a tin filling amount of more than 75% of the PCB board thickness. The pinhole size on the solder joint is less than 1/4 of the cross-sectional area of the part foot, and the pinhole at any point does not penetrate the PCB.
The difference between PCB and PCBA
PCB is the carrier and basic framework of electronic components, while PCBA is a circuit board assembly with specific functions, which directly determines the performance and function of electronic products.
Definition and Function
1.PCB (printed circuit board): It does not contain any active or passive components itself, but is just a basic framework. Definition: PCB is a substrate used for electrical connection of electronic components, which forms a conductive circuit pattern on an insulating substrate through etching, drilling, copper plating and other processes. Function: PCB mainly plays the role of supporting and electrically connecting electronic components, and is the carrier of electronic components.
2.PCBA (printed circuit board assembly) PCBA is the core part of electronic products and directly determines the performance and function of the product. Definition: PCBA is a circuit board assembly with specific functions formed by soldering electronic components to PCB through processes such as SMT (surface mount technology) or THT (through-hole mounting technology). Function: PCBA contains PCB and all necessary electronic components, which work together to realize the preset functions of the circuit board.
Manufacturing process
1.PCB manufacturing process Design: Design the PCB layout according to the circuit schematic. Making the substrate: Use materials such as copper foil, insulating materials and prepreg to make the substrate of the PCB. Etching: Remove the unnecessary copper foil part on the substrate by chemical or physical methods to form a conductive circuit pattern. Drilling: Drill holes on the PCB for connecting different layers or installing components. Copper plating: Plate a layer of copper in the hole and on the surface of the circuit to improve conductivity and solderability. Subsequent processing: Including steps such as cleaning, inspection, and cutting, and finally get the finished PCB.
2.PCBA manufacturing process Preparation: Prepare the required PCB and electronic components. Welding: Solder the electronic components to the PCB through SMT or THT technology. Detection: Use automated testing equipment to perform functional testing and quality inspection on PCBA. Packaging: Package qualified PCBA for transportation and storage.
Features and applications
1.PCB features Customization: PCB can be customized according to specific needs to meet the layout requirements of different circuits and components. Standardization: PCB manufacturing follows certain standards and specifications to ensure product quality and reliability. Flexibility: PCB can adapt to various complex circuit designs and component layout requirements. Widely used: PCB is widely used in various electronic products, such as mobile phones, computers, home appliances, etc.
PCBA features Functionality: PCBA has specific functions and can be directly used for the assembly and testing of electronic products. Integrity: PCBA contains all the necessary electronic components and PCBs, and is a complete circuit board assembly. Reliability: After rigorous testing and inspection, PCBA has high reliability and stability. Specific application: PCBA is usually used on the production line of electronic products and directly participates in the assembly and testing process of the product.
The difference between PCBA and SMT
PCBA VS SMT
There are significant differences between PCBA processing and SMT processing in terms of definition and scope, component types and assembly methods, process flow and equipment, application fields and product features.
Definition and scope PCBA processing is a broader concept that covers the entire process of assembling electronic components onto printed circuit boards, including circuit board design, component selection, welding, testing and other links. PCBA processing can use both through-hole technology (THT) and surface mount technology (SMT). SMT processing is an important link in PCBA processing, specifically referring to the process of mounting surface mount components (such as chip resistors, chip capacitors, etc.) on the surface of printed circuit boards using surface mount technology. SMT processing usually includes steps such as printing solder paste, mounting components, and reflow soldering.
Component types and assembly methods PCBA processing can handle various types of components, including through-hole components (such as integrated circuits in DIP packages) and surface mount components. Through-hole components need to be soldered to the other side of the circuit board through the jack, while surface mount components are directly mounted on the surface of the circuit board. SMT processing focuses on processing surface mount components. These components have the characteristics of small size, light weight, no pins or short pins, which can achieve high-density assembly, thereby improving the integration and performance of circuit boards.
Process flow and equipment The application field of PCBA processing is very wide, covering almost all industries that require electronic circuit boards, such as communications, medical, aviation, home appliances, etc. Since PCBA processing can handle various types of components and complex assembly requirements, it is suitable for the production of electronic products of various sizes and complexities. SMT processing is more suitable for the production of miniaturized, lightweight, and highly integrated electronic products. Since surface mount components are small and light, SMT processing can achieve high-density assembly, thereby reducing product volume and weight. In addition, SMT processing also has the advantages of high production efficiency and stable product quality.
PCBA Common Terms
Surface mount assembly (SMA): a printed circuit board assembly completed using surface mount technology.
Reflow soldering: the connection between surface mount components and PCB pads is achieved by melting the solder paste pre-allocated to the PCB pads.
Wave soldering: the molten solder is sprayed into a solder wave crest as required by the design through the equipment, so that the PCB with electronic components passes through the solder wave crest to achieve the connection between the components and the PCB pads.
Solder paste printing: the solder paste is placed on the steel mesh, and the solder paste is leaked through the holes on the steel mesh by a scraper and accurately printed on the PCB pads.
Automated optical inspection (AOI): the soldering effect of the PCB board can be detected by scanning and comparing. Defective PCB boards can be detected.
Rework: the act of reworking defective boards detected by AOI or manual inspection.
Fine pitch: refers to the lead center spacing of surface mounted package components ≤ 0.50mm.
Gerber file: A collection of document formats that describe circuit board images and drilling and milling data, used for PCBA quotation and processing.
BOM file: A bill of materials that lists all materials and quantities required for PCBA processing.
Solder paste deviation, solder paste tip, solder paste hole, etc.: These are common defects in PCBA processing.
FAQ About PCBA
FAQ Abaout PCBA
Why can PCBA processing improve the reliability and stability of circuit boards? PCBA processing can greatly reduce the failure rate of products, speed up the launch of products, and improve production efficiency through strict quality management system, strict control and quality inspection from component procurement to production process.
How to ensure the quality of PCBA? The key to ensuring the quality of PCBA lies in a strict quality management system, including strict control and quality inspection from component procurement to production process.
How to control the cost of PCBA processing? Methods to control the cost of PCBA processing include optimizing design, reducing component costs, and improving production efficiency.
How to choose a suitable PCBA processing plant? Selecting a PCBA processing plant requires considering factors such as the factory’s equipment, quality management system, production capacity, and experience.
What are the problems and causes of cold soldering in PCBA? Due to insufficient solder paste, insufficient soldering temperature, or too short soldering time, no effective soldering is formed between the component pins and the pads, which may cause circuit blockage or poor contact.
What are the problems and causes of cold welding? Due to the low welding temperature, the welding material is not completely melted, which is manifested as the surface of the welding point is rough, gray, and has no gloss. The welding strength is insufficient, which can easily cause the welding point to break.
What are the problems and causes of continuous welding? Due to excessive application of solder paste or the pins of adjacent components are too close, a connection is formed between welding points that should not be connected, which may cause a short circuit.
What are the problems and causes of component damage? Due to static electricity, overheating, mechanical stress and other reasons, the performance of components is reduced or completely fails, affecting the overall circuit function.
What are the problems and causes of component misalignment? Due to equipment failure, operating errors and other reasons during the patch process, the components are not aligned with the pads on the PCB, which may cause poor welding or abnormal circuit function.
What are the problems and causes of PCB contamination? During the production and storage process, it is polluted by oil stains, dust and other pollutants, which affects the welding effect and may cause problems such as poor welding or short circuit.
What are the problems and causes of PCB deformation? Due to environmental factors such as high temperature and humidity, PCB deformation affects the mounting and welding of components, which may cause abnormal circuit function.
What are the problems and causes of missed inspection of PCBA? Due to failure of detection equipment, operating errors, etc., defective products may flow into the next process or market, affecting product quality and customer satisfaction.
What are the problems and causes of PCBA mixing? During the production process, components or PCBs are mixed, resulting in product performance not meeting requirements, which may cause customer returns or claims.
