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Exciting News! Best Technology, a leading PCB assembly manufacturer from China, will be exhibiting at PCB West in Santa Clara California. Join us at Booth No. 414 on Oct 1^st (Wednesday). If you missed us at New Tech or Expo Electronica, this is your chance!

At our booth, you’ll have the opportunity to explore our advanced PCB manufacturing and assembly technologies. For reference, here is a booth location detail.

In the exhibition, our team of experts will be available to share in-depth knowledge about PCB assembly, from prototyping to low and high-volume production. We invite all interested professionals/engineers to visit and discover our capabilities in flexible circuit boards, rigid-flex circuits (2 to 50 layers), copper weights from 1/2 OZ to 30 OZ, and ultra-thin PCBs (0.15mm FR4) to heavy copper options. Best Technology offers a full turn-key service including component sourcing, board fabrication (FPC, PCB, MCPCB, Ceramic PCB), final assembly, programming, testing, and more.

We welcome you to explore how we manage component wastage and boost efficiency, helping you save time, money, and resources.

Here are some pictures that we attending PCB west last time:

Be sure to visit us at Booth 414 to see how we optimize efficiency, reduce component wastage, and help you save on time, money, and energy.

For more details and to register, visit:

Schedule for PCB West 2025

We look forward to seeing you in California!

PTFE copper clad laminate is one of the most important base materials in high-frequency printed circuit boards. It is made by bonding copper foil with PTFE, also known as polytetrafluoroethylene. This material is widely used in microwave, RF, and high-speed digital circuits where low signal loss and stable performance are critical.

While FR-4 laminates serve well in general electronic devices, PTFE laminates take performance to another level. Their unique dielectric properties and stability in harsh conditions have made them the preferred choice in aerospace, defense, 5G communication, radar, and advanced automotive systems.

In this blog, we will explore what PTFE copper clad laminate is, its electrical characteristics, why industries rely on it, and how Best Technology can support you with reliable supply and engineering expertise.

What is PTFE Copper Clad Laminate in PCB Manufacturing?

PTFE copper clad laminate is a composite base material created by pressing a thin copper sheet onto a PTFE substrate. PTFE is well known for its chemical resistance and low dielectric constant. When combined with copper, it forms a highly stable laminate for circuit fabrication.

This material serves as the foundation for etching circuit patterns and creating transmission lines in PCBs. Because PTFE exhibits excellent electrical insulation and thermal stability, it is the go-to choice for applications requiring precision in high-frequency ranges.

Unlike traditional laminates, PTFE-based materials are engineered specifically to handle sensitive signals. They support microstrip lines, stripline designs, and other controlled impedance circuits that are essential for RF engineering.

How Does PTFE Differ from FR4 in PCB Laminates?

The biggest difference between PTFE and FR4 laminates lies in their dielectric and thermal performance. FR4, made of woven fiberglass and epoxy resin, offers sufficient electrical insulation for consumer electronics, but it falls short when frequencies increase.

FR4 typically has a dielectric constant (Dk) around 4.2–4.5, while PTFE laminates maintain values as low as 2.0–2.2. This lower Dk allows signals to travel faster with reduced delay.

Another key point is loss tangent, or dissipation factor (Df). FR4 materials may reach 0.02 or higher, whereas PTFE stays around 0.0009–0.002, which is far more efficient for high-frequency circuits.

Thermal stability is also superior. FR4 begins to degrade around 130–150°C, while PTFE-based laminates can withstand much higher ranges without major performance shifts. This is vital for aerospace and military systems exposed to extreme conditions.

Simply put, when precision, speed, and minimal loss matter, PTFE laminates outperform FR4 by a wide margin.

What Are the Electrical Properties of PTFE Copper Clad Laminate?

The electrical properties of PTFE laminates are the reason they are so valuable. Some key characteristics include:

Property	Typical Value	Significance in PCB Design
Dielectric Constant (Dk)	2.0 – 2.2 (stable across frequency)	Lower Dk allows faster signal propagation with reduced delay.
Dissipation Factor (Df)	0.0009 – 0.002	Extremely low loss, minimizing signal attenuation in high-frequency circuits.
Dielectric Strength	> 500 V/mil	Provides strong insulation, preventing electrical breakdown under stress.
Moisture Absorption	< 0.01%	Almost zero water uptake, ensuring stable performance in humid environments.
Volume Resistivity	> 10¹⁵ Ω·cm	Maintains excellent insulation resistance even under thermal or electrical stress.
Thermal Stability	High (usable above 200°C)	Supports reliable operation in aerospace, automotive, and defense electronics.

Why is PTFE Copper Clad Laminate Important for High-Frequency PCBs?

At high frequencies, even small material imperfections can distort signals. PTFE laminates minimize these risks with their stable dielectric constant and low loss tangent. This results in clear signal transmission, which is crucial for RF and microwave devices.

In applications such as radar, phased-array antennas, and satellite communication, accuracy cannot be compromised. PTFE laminates deliver repeatable performance even when exposed to temperature shifts, high power levels, or mechanical stress.

Another reason for their importance is impedance control. Designing circuits at GHz frequencies requires precise line widths and predictable laminate behavior. PTFE offers that predictability, which helps engineers design with confidence.

Without PTFE laminates, many of today’s wireless and defense technologies would not function with the required accuracy and reliability.

What Are the Common Applications of PTFE Copper Clad Laminates?

PTFE copper clad laminates are widely used in industries where high-frequency performance is a must. Some typical applications include:

• 5G Communication Systems: For antennas, base stations, and signal routers.
• Aerospace and Defense: In radar modules, missile guidance systems, and avionics.
• Automotive Electronics: Used in advanced driver-assistance systems (ADAS) and vehicle radar.
• Medical Equipment: Applied in MRI systems and diagnostic imaging requiring clear signals.
• Satellite and Space Communication: Critical for stable transmission in extreme environments.
• High-Speed Digital Devices: Essential for data centers and supercomputers handling large bandwidths.

These industries cannot afford distortion, delay, or instability. PTFE laminates provide the reliability needed for next-generation technologies.

What Are the Processing Challenges of PTFE Laminates in PCB Fabrication?

While PTFE laminates deliver outstanding electrical performance, they are not the easiest to process. Manufacturers face several challenges, such as:

• Softness of PTFE: The material is softer than FR4, making drilling and machining more complex. Specialized bits are often required.
• High Thermal Expansion: PTFE expands more under heat, which demands careful process control during lamination.
• Bonding Issues: PTFE’s chemical resistance makes it harder for copper to adhere without special treatments or bonding films.
• Dimensional Stability: Without proper handling, warping may occur.

These challenges increase fabrication costs compared to standard FR4 boards. However, experienced PCB manufacturers, like Best Technology, have developed methods to manage these issues efficiently. The result is reliable, high-performance boards without compromising quality.

How Does PTFE Copper Clad Laminate Improve Signal Performance?

Signal performance is the main advantage of PTFE laminates. With their low Dk and Df, signals pass through the board with less distortion and attenuation. This is especially critical in RF designs where even small losses translate into reduced range or efficiency.

The reduced dielectric loss improves power handling as well. Devices such as power amplifiers benefit from higher efficiency, which lowers energy waste and heat generation.

Additionally, PTFE laminates reduce cross-talk between adjacent lines. This improves signal isolation and helps maintain cleaner communication channels, a necessity in high-density RF layouts.

Overall, PTFE laminates provide the foundation for achieving superior signal clarity, speed, and reliability in demanding applications.

Where Can You Buy Reliable PTFE Copper Clad Laminate PCBs?

Not every PCB supplier is equipped to process PTFE laminates. The material requires specialized equipment, expertise, and strict quality control. When choosing a supplier, factors like certifications, engineering support, and track record in high-frequency boards are important.

Best Technology is a trusted manufacturer of advanced PCBs, including PTFE-based designs. With certifications such as ISO9001, ISO13485, IATF16949, and AS9100D, the company meets stringent standards for industries ranging from medical to aerospace.

Using an MES system, Best Technology guarantees traceability of every component and process step. Combined with competitive pricing and a highly skilled engineering team, the company provides dependable solutions for complex PCB needs.

Whether you require prototypes or volume production, Best Technology offers PTFE copper clad laminate PCBs tailored to your application.

Conclusion

PTFE copper clad laminates are at the core of modern high-frequency electronics. Their unique electrical characteristics—low dielectric constant, minimal loss, and excellent stability—make them essential for applications in 5G, radar, aerospace, and beyond.

While they are more challenging to process than FR4, the advantages in performance far outweigh the difficulties. Partnering with an experienced manufacturer ensures you get the benefits without the risks.

At Best Technology, we combine strict quality systems, professional engineering support, and advanced manufacturing capabilities to deliver reliable PTFE-based PCBs. Our certifications across medical, automotive, and aerospace industries reflect our commitment to excellence. If you are looking for a partner to support your high-frequency designs, Best Technology is ready to help.

FAQs

1. What is the dielectric constant of PTFE copper clad laminate?

The dielectric constant is typically 2.0–2.2, stable across different frequencies and temperatures.

2. Is PTFE copper clad laminate suitable for 5G PCBs?

Yes, it is widely used in 5G base stations, antennas, and routers due to its low signal loss.

3. What is the cost difference between PTFE laminate and FR4?

PTFE laminates are more expensive because of material cost and processing complexity, but their performance justifies the price in high-frequency applications.

4. Can PTFE copper clad laminate handle high temperatures?

Yes, PTFE laminates perform reliably under high thermal conditions, making them suitable for aerospace and automotive environments.

5. How do you choose the right PTFE laminate supplier?

Look for certifications, proven experience in high-frequency PCBs, and advanced quality systems like MES for process traceability.

If you are working on high-power electronics, LED lighting, or power conversion modules, thermal management is probably one of your biggest challenges. That’s where the double sided IMS PCB comes into play.

As a reliable IMS PCB manufacturer, Best Technology has been helping engineers and purchasing teams solve complex design issues using double sided metal core solutions that offer excellent thermal performance and mechanical strength. Our products are widely used in various applications like LED lighting, automotive electronics, power modules, and more.

What Is a Double Sided IMS PCB?

A double sided IMS PCB (Insulated Metal Substrate Printed Circuit Board) is a type of PCB that uses a metal base—typically aluminum or copper—combined with two copper layers and insulating dielectric layers in between. This structure allows designers to place components on both sides or route critical signals more efficiently while managing heat effectively.

Unlike single-sided IMS PCBs that have components and traces only on one side, double-sided versions support components mounting and traces layout both on top and bottom side, it allowed complex designs, higher current flow, and better heat transfer through thermal vias.

In simple terms: if your board gets hot and needs more routing space, a double sided IMS PCB can help.

Double Sided IMS PCB Structure

A double sided IMS PCB is built with multiple carefully selected layers, designed to balance electrical performance, mechanical strength, and heat dissipation. The general structure looks like this:

• Top copper layer: Carries the electrical traces and component pads.
• Top dielectric layer: An electrically insulating but thermally conductive material.
• Metal core: Usually aluminum or copper, it serves as a mechanical base and heat sink.
• Bottom dielectric layer: Same material as the top layer, separating the metal core from the bottom copper.
• Bottom copper layer: It is a trace layer, used for power, ground, or additional signal traces.

Plated through holes (vias) allow electrical connection between the top and bottom copper layers. These vias can also help conduct heat away from hot components into the metal core, improving thermal performance.

Types of IMS PCB Materials

In IMS PCB design, the metal base plays a critical role in heat dissipation and mechanical stability. The two most commonly used core materials are aluminum and copper, each with distinct advantages and application scenarios.

1. Aluminum-Based IMS PCB

Aluminum is by far the most widely used metal base material in IMS PCBs. It offers a great balance between cost, weight, and thermal performance. With a typical thermal conductivity of 1.0 to 3.0 W/m·K, aluminum is sufficient for most applications where moderate heat needs to be managed efficiently.

Advantages of aluminum base:

• Cost-effective: More affordable than copper, suitable for mass production.
• Lightweight: Ideal for weight-sensitive designs like automotive lighting and portable devices.
• Corrosion-resistant: Naturally forms a protective oxide layer, extending board life.
• Good thermal conductivity: Capable of dissipating heat from surface-mounted components quickly.

Typical applications:

• LED lighting systems (e.g. street lights, home bulbs)
• Power driver boards
• Consumer electronics
• Automotive LED modules

Aluminum IMS PCBs are perfect for designs that need reasonable thermal performance at a lower cost. They’re especially common in LED products, where keeping junction temperature low is essential to extending light source life.

2. Copper-Based IMS PCB

Copper-based IMS PCBs are chosen when thermal management becomes critical, or when mechanical robustness is equally important. Copper has a thermal conductivity of around 5.0 W/m·K—more than double that of aluminum—making it an ideal choice for high-power or high-density applications.

Advantages of copper base:

• Superior heat dissipation: Excellent for fast heat transfer in high-power designs.
• High mechanical strength: Less prone to flexing or warping under load or heat.
• Stable performance at high temperatures: Supports continuous operation in demanding environments.
• Better current carrying capacity: Enables narrower traces for the same current level.

Typical applications:

• Power inverters and converters
• Motor control units and industrial drives
• RF amplifiers and telecom power modules
• Aerospace and defense electronics
• High-performance LED arrays

Due to its higher cost and weight, copper is generally used in specialized applications where reliability, thermal performance, or current handling are mission-critical. It’s especially favored in automotive power systems, high-end industrial equipment, and aerospace control circuits.

Single vs Double Sided IMS PCB

When choosing between single-sided and double-sided IMS PCBs, understanding their structural and functional differences is essential. Below is a detailed comparison covering performance, design flexibility, manufacturing complexity, and cost.

Comparison Aspect	Single Sided IMS PCB	Double Sided IMS PCB
Copper Layers	One layer on top	Two layers – top and bottom
Component Placement	Only on one side	Possible on both sides or top side with backside routing
Thermal Conductivity Path	Heat moves in one direction (top to base)	Heat can dissipate through both layers via thermal vias
Routing Flexibility	Limited routing options	More complex, denser routing possible
Via Usage	Usually no plated vias	Requires plated through vias for inter-layer connections
Design Complexity	Simpler, suitable for low-power applications	Supports more complex, high-current designs
Manufacturing Cost	Lower cost, fewer steps	Higher cost due to drilling, plating, and alignment
Board Thickness	Generally thinner	Slightly thicker due to multilayer structure
Current Carrying Capacity	Limited by single copper layer	Higher due to dual copper planes
Mechanical Strength	Moderate	Higher due to more balanced structure
Typical Applications	LED bulbs, indicator lights, basic power supplies	LED headlights, motor drivers, power inverters
Preferred Use Cases	Cost-sensitive and thermally moderate projects	Thermally demanding, high-power, or complex circuitry

At Best Technology, we provide both types with full engineering support, helping you select the right option based on your performance goals and budget.

IMS PCB Design Considerations

Designing an effective IMS PCB, especially a double sided IMS PCB, requires more than just basic layout knowledge. As a professional IMS PCB manufacturer, we often find that early-stage design decisions directly impact not only the cost but also manufacturability, reliability, and thermal performance.

Here are our top recommendations to help you design a high-quality IMS PCB that meets both technical and production requirements:

1. Understand the Thermal Path Early

IMS PCBs are often chosen for their excellent heat dissipation. To maximize this advantage:

Place heat-generating components (like LEDs, power ICs, MOSFETs) directly above the metal core or near thermal vias.

• Use thermal reliefs for pads to balance solderability and heat transfer.
• Avoid thick dielectric layers if fast heat conduction is critical—choose higher thermal conductivity materials instead.

2. Use Plated Vias Wisely

In double sided IMS PCBs, plated through holes (vias) are crucial to connect the top and bottom copper layers. However:

• Vias increase cost due to drilling and plating steps.
• Avoid placing too many vias near mechanical mounting holes to prevent cracking during assembly.
• For high-current paths, increase via diameter and plating thickness, or use multiple thermal vias in parallel.

3. Optimize Trace Widths and Spacing

Due to higher currents in IMS boards:

• Use wider traces wherever possible, especially for power lines.
• Respect minimum clearance based on copper thickness and voltage—this prevents arcing and improves reliability.
• Avoid sharp 90° corners on high-current or RF traces; use 45° or curved corners instead.

If you’re not sure how wide your traces should be, send us your current ratings—we’ll recommend widths based on IPC standards and real-world performance.

4. Select Suitable Copper Thickness

For IMS PCBs, copper thickness directly impacts both electrical and thermal performance:

• Standard thickness is 1oz (35µm), suitable for low to medium current.
• For high current or improved thermal conduction, 2oz or 3oz copper is recommended.
• Very thick copper (up to 10oz) is possible, but it increases cost and etching complexity.

5. Component Layout Planning

• Avoid clustering hot components together—spread them out to help heat dissipation.
• Keep temperature-sensitive components (like ICs, sensors) away from heat sources.
• Leave clearance around mounting holes to prevent shorting with metal base.

6. Surface Finish Compatibility

Tell us your assembly process (manual, reflow, wave soldering) and component pitch—we’ll advise the best finish.

• ENIG is recommended for flat surfaces and fine-pitch components.
• HASL is affordable but not ideal for tight layouts.
• Immersion silver and OSP are good for high-frequency circuits.

7. Share Your Design Goals Early

Many designers only share Gerber files at the last step. But as a manufacturer, we can provide more value when we’re involved earlier.

• Let us know if your priority is cost, thermal performance, space saving, or high current.
• Share thermal simulation data if available—we can help validate materials and layout choices.
• If you’re unsure between aluminum and copper base, we can guide based on your budget and operating temperature.

Contact us early often helps reduce revisions, avoid design traps, and improve yield—saving both time and money.

Double Sided IMS PCB Manufacturing Process

Manufacturing a double sided IMS PCB involves multiple controlled steps. Here’s we simply introduce the manufacturing processed involving in the insulated metal substrate fabrication:

1. Material Lamination

The copper foils and dielectric are laminated on both sides of the metal base with high pressure and temperature.

2. Drilling & Via Formation

Mechanical or laser drilling creates via holes through the board. These holes are then plated with copper to allow connectivity between top and bottom copper layers.

3. Imaging & Etching

Circuit patterns are created on both copper layers using photoresist and chemical etching.

4. Solder Mask Application

Solder mask is applied to protect copper from oxidation and to guide solder placement during assembly.

5. Surface Finishing

Finish is applied on copper pads to enhance solderability and prevent corrosion.

6. Testing

Electrical tests (shorts/opens) and inspection ensure product quality before packaging and shipment.

Here is a completed manufacturing process of IMS PCB.

Double Sided IMS PCB Surface Finish Options

• HASL (Lead-free): Affordable, but not ideal for fine-pitch components.
• ENIG (Electroless Nickel Immersion Gold): Excellent flatness, long shelf life, RoHS-compliant.
• ENEPIG: Very good solderability, corrosion resistance, durable.
• OSP: Cost-effective and environmentally friendly, but short shelf life.
• Immersion Silver: Good for high-frequency signals, flat and solderable.
• Hard Gold: Very durable, typically used for connectors or edge contacts, but rarely used in IMS PCB, it is popular in FR4 PCB.

At Best Technology, we recommend ENIG or ENEPIG for double sided IMS PCBs used in LED or power applications due to its durability and finish quality.

Cost Factors of Double Sided IMS PCB

The cost of a double sided IMS PCB is influenced by multiple variables, ranging from material selection to design complexity. As a manufacturer, we often find that many cost increases come from early design decisions. Here are the main cost drivers you should be aware of:

1. Material Type

Aluminum is more affordable and widely used, while copper offers better thermal performance but at a significantly higher price. If your project doesn’t demand extreme thermal performance, aluminum is usually the better choice from a budget perspective. High Tg costs more.

2. Copper Weight

Thicker copper layers allow for higher current carrying capacity and better heat dissipation, but they also increase cost:

• Standard: 1oz (35µm)
• Mid-range: 2oz – 3oz
• Heavy copper: 4oz – 10oz (used in power-intensive designs)

Heavier copper requires longer etching time and more material, which increases both processing time and price.

3. Board Size & Shape

Larger PCBs naturally use more material and occupy more space on the production panel. Irregular shapes also lead to more material waste and extra routing time.

• Square or rectangular boards make better use of panel space.
• Rounded or irregular outlines may require CNC routing or laser cutting, which adds cost.

4. Via Count and Type

Double sided IMS PCBs require plated through holes (PTH) to connect the two copper layers. The more vias you have, and the smaller their diameter, the more complex and expensive the drilling and plating process becomes. Via-in-pad, filled vias, and microvias are more expensive.

5. Dielectric Layer Thickness

Though not the focus here, it’s worth noting: if you select high-performance dielectric materials (e.g., with higher thermal conductivity or thinner thickness), the price will increase. These materials are more specialized and costlier to produce.

6. Special Features

Any additional processes will increase cost, such as:

• Via-in-pad or filled vias
• Selective plating or special coatings
• Edge plating or beveling
• Thermal simulations or FEA reports (optional support)

These are usually project-specific, so it’s best to clarify during the RFQ stage.

Best Technology – Your Reliable IMS PCB Manufacturer

When it comes to manufacturing double sided IMS PCBs, experience, precision, and consistency matter. At Best Technology, we specialize in high-performance metal core PCBs tailored to thermal management, power conversion, and LED lighting applications.

We offer:

• Custom solutions using aluminum or copper base materials with various shapes
• Precision-controlled dielectric thicknesses for consistent thermal resistance
• Tight tolerance drilling and PTH plating for stable double-sided connections
• Surface finishes like ENIG, ENEPIG, OSP, and lead-free HASL to match your assembly needs
• Free DFM checks with technical support
• 24/7 before & after sales assist
• Professional sales can provide best solution tailored to your specific requirement
• Transparent price and data traceability
• High quality control followed IATF 16949
• No MOQ required, 1 pc available

Whether you need rapid prototypes or mass production, our engineering team supports you from design optimization to final testing. We believe that a good PCB starts with good communication—and we’re always ready to listen.

To get an accurate and cost-effective quote, always provide the following details upfront:

• Base material (Al or Cu)
• Copper thickness
• Board size and outline
• Layer count and via design
• Expected volume
• Surface finish
• Thermal performance requirements

Send your Gerber files or RFQ to sales@bestpcbs.com to get started.

FAQs

Q1: What is the thermal conductivity of a double sided IMS PCB?

It depends on the dielectric used. Standard ranges are 1.0 to 3.0 W/m·K, with higher options available for demanding designs.

Q2: Can I place components on both sides of a double sided IMS PCB?

Typically, one side is reserved for power routing or heat dissipation, but yes, it’s technically possible depending on the application.

Q3: What surface finish is best for LED applications?

ENIG is recommended for its flatness, solderability, and long shelf life.

Q4: Are double sided IMS PCBs expensive?

They cost more than single-sided IMS or standard FR4 PCBs, but offer much better thermal and electrical performance, especially for power-intensive designs.

Q5: How can I get a quote from Best Technology?

Just email your Gerber files and requirements to sales@bestpcbs.com, and we’ll respond within 24 hours.

Custom circuit board design is the process of creating a PCB layout tailored to meet specific project needs. Unlike off-the-shelf solutions, a custom PCB gives you complete control over size, shape, layer stack-up, routing, and component placement. Whether you’re building a compact wearable, a robust industrial device, or a specialized automotive controller, a custom layout helps improve performance and space efficiency.

Who Needs a Custom Circuit Board Design?

Custom circuit boards are essential for engineers, startups, hardware developers, and OEMs who can’t rely on generic PCBs. If you’re designing a unique product or working with unusual form factors or power requirements, a custom design is your only option. This includes industries like:

• Medical devices needing miniaturized, high-reliability circuits.
• Automotive and aerospace systems requiring rugged, multilayer PCBs.
• Consumer electronics developers seeking sleek, compact designs.
• Industrial automation and control systems.
• Research and development teams creating prototypes.

In short, if your project demands specific functions, form factor, or performance that standard PCBs can’t deliver, it’s time for a custom solution.

Circuit Board Design Rules

Design rules form the foundation of a reliable custom circuit board design. They’re not just about meeting DRC checks but ensuring your board works correctly in the field. Here are the most important and professional-level design constraints to follow:

1. Minimum trace width and spacing:

For standard 1 oz copper (35μm), a minimum trace width of 6 mil (0.15mm) is commonly used for signal lines. Power traces may require 10–20 mil or more, depending on the current. Use IPC-2221 charts or online calculators to determine width based on current (e.g., a 1A trace over 1oz copper typically needs 15 mil for internal layers, 10 mil for outer layers).

2. Minimum spacing:

Standard fabrication allows 6 mil spacing, but for HDI designs or high voltage isolation, use wider spacing. IPC-2221 recommends 63 mil (1.6mm) spacing for 250V isolation.

3. Via size and annular ring:

A typical via uses a 0.3 mm drill with 0.6 mm pad size, leaving a 0.15 mm annular ring. For HDI, microvias can be as small as 0.1 mm.

4. GND plane design:

Always use a solid ground plane on an internal layer. For multi-layer boards, dedicate one layer (often the second layer) as a continuous GND plane to reduce EMI and support return current paths. For analog and digital mixed-signal boards, separate analog GND and digital GND, and connect them at a single point near ADC/DAC.

5. High-speed signal rules:

Use controlled impedance for differential pairs and high-speed single-ended lines. Keep length mismatches for differential pairs within ±5 mils, and spacing between the pair should be 2–3 times the trace width.

6. Creepage and clearance:

Follow IPC-2221 standards for high-voltage boards. For instance, for 240V AC, you need minimum 3.2mm clearance between conductors.

7. DRC and design checks:

Always define your DRC settings based on your manufacturer’s capabilities. Most manufacturers support 4/4 mil (trace/space) in standard processes, but 6/6 mil is more commonly used for robustness.

How to Layout Your DIY Circuit Board?

Laying out your custom PCB starts with strategy. A great schematic won’t save a poor layout, especially for fast signals or complex systems. Here’s a professional approach to DIY or low-volume layout:

1. Start with a block-level floorplan:

Divide your circuit into sections (power, MCU, analog, RF, connectors) and place them logically. Keep high-speed signals short and isolated from analog traces.

2. Place decoupling capacitors close:

Every IC power pin should have a 0.1μF ceramic capacitor placed within 1–2 mm of the pin, with a short path to the ground plane.

3. Use polygon pours for GND:

Instead of routing GND traces, pour solid copper polygons for GND connections. Ensure the polygon is tied to a proper ground net and has enough vias to connect to internal GND planes (1 via per 1–2 cm² area is a good rule).

4. Signal layer planning:

In a 4-layer board:

• Top layer: Signals and components
• 2nd layer: Solid GND plane
• 3rd layer: Power plane
• Bottom layer: Secondary signals

This gives you clean return paths and effective power distribution.

5. Controlled impedance routing:

For USB, HDMI, Ethernet, and RF signals, match the impedance (typically 50Ω single-ended or 100Ω differential). Use your PCB software’s impedance calculator or external tools like Saturn PCB Toolkit. Factors include trace width, dielectric height, and copper thickness. For instance, a 50Ω microstrip over 1.6mm FR-4 (εr=4.2) might require 12 mil trace width over 10 mil height.

• Differential pair routing:
• Keep equal length (match to within ±5 mils).
• Maintain consistent spacing.
• Avoid 90° bends—use two 45° bends or arcs.

6. Avoid stubs and isolated copper:

Any unused copper or hanging trace stubs can act as antennas. Remove them to reduce EMI.

7. Thermal relief and copper balance:

For through-hole pads connected to GND or power planes, use thermal reliefs to aid soldering. Also, ensure copper is balanced across layers to avoid warping.

PCB Design Software

You can’t design a custom board without the right software. Depending on your experience and budget, here are some options:

• KiCad (Free, open-source): Ideal for beginners and hobbyists. Offers schematic capture, PCB layout, and 3D visualization.
• EAGLE (Free for students and small projects): Good integration with Fusion 360 and supports complex designs.
• Altium Designer (Paid): Industry standard for advanced features like high-speed routing, simulation, and collaboration tools.
• EasyEDA (Cloud-based): Great for quick prototypes and integrates directly with fabrication services.
• OrCAD/PADS: Often used in professional environments for complex multilayer boards.

Choosing the right tool depends on your project’s needs, from simple prototypes to multilayer, production-ready boards. Here are the top 10 PCB design software that engineer commonly used.

Considerations During Designing a Custom Circuit Board

Designing a custom PCB isn’t just about making connections—it’s a balancing act between performance, cost, and manufacturability. Here’s what to consider:

• Board size and shape: Compact designs can save space but are harder to route.
• Number of layers: Multilayer boards improve performance but increase cost.
• Component availability: Choose parts that are easy to source and compatible with your assembler’s equipment.
• Thermal management: Use heat sinks, thermal vias, or copper pours to manage heat.
• Manufacturing capabilities: Make sure your design matches your fabricator’s limits for trace width, hole size, and stack-up.
• Testing and debugging: Leave space for test pads, headers, or diagnostic LEDs.

Thoughtful planning during the design phase saves time and avoids problems during production.

Where Can I Get a Custom Circuit Board?

You can order a custom circuit board from online PCB manufacturers or local fabrication shops. Some popular platforms include:

• JLCPCB
• PCBWay
• Sierra Circuits

However, if you’re looking for a highly reliable one-stop PCB solution with both fabrication and assembly services, it’s better to work with a professional company that understands the full production lifecycle.

Best Technology is your trusted partner for custom circuit board design, manufacturing, and assembly. With ISO9001, IATF16949, ISO13485, and AS9100D certifications, we follow strict quality systems to ensure that your project meets industry standards. Below are some advantages that customers why choose us:

• Full customization for single-sided, multilayer, ceramic, metal-core, and HDI boards.
• Advanced engineering support from schematic to layout optimization.
• Fast prototyping with 24/7 customer service and on-time delivery.
• Traceability with MES system, covering every process step for your peace of mind.
• Competitive pricing without compromising on quality.

Whether you’re a startup building a prototype or a Fortune 500 company scaling production, we’re here to support every step of your journey.

Contact us now to get a quote or free design consultation.

FAQs

1. What file format is needed to get a custom PCB made?

You’ll typically need Gerber files, CAD, BOM (Bill of Materials), and a pick-and-place file for assembly.

2. How long does custom PCB manufacturing take?

Depending on complexity and quantity, fabrication may take 3–7 days, with assembly adding 2–5 more days. Expedited service is available.

3. Can I get a custom PCB in small quantities?

Yes. Many manufacturers, including Best Technology, support low-volume and prototype runs.

4. Is custom PCB design expensive?

The cost depends on board complexity, number of layers, and turnaround time. Simple designs are very affordable today.

5. Do you help with PCB design revisions?

At Best Technology, yes—we offer design assistance and layout reviews to ensure your files are ready for production.

In high-speed electronic systems, signal integrity is crucial. One of the key factors that ensures clear, distortion-free signal transmission is impedance control. In this blog, we’ll explore what impedance control is, why it’s important in PCB design, how it’s calculated, and what factors influence it. Whether you’re a PCB designer or sourcing boards from a manufacturer, understanding impedance control is essential to ensuring performance and reliability.

What Is Impedance in a PCB?

Impedance refers to the resistance a circuit offers to alternating current (AC), especially in the presence of inductors and capacitors. In simple terms, it’s how much the signal “fights back” as it moves through the traces on a PCB. The unit of impedance is Ohms (Ω).

In PCBs, impedance isn’t just about resistance—it includes the effects of capacitance and inductance created by the PCB’s structure and materials. That’s why it needs to be tightly controlled, especially in high-speed signal circuits.

Why Is Impedance Matching Needed?

Impedance matching is essential to ensure efficient signal transmission across different parts of an electrical system. When the impedance of a signal source, transmission path (such as a PCB trace), and load are not properly matched, it causes signal reflection, power loss, and distortion—especially in high-speed or RF designs.

Key reasons why impedance matching is necessary:

• Prevents Signal Reflection: Any mismatch causes part of the signal to bounce back to the source, interfering with the original signal and creating noise.
• Maintains Signal Integrity: For data to reach its destination accurately and consistently, impedance must be uniform along the transmission path.
• Reduces EMI (Electromagnetic Interference): Mismatched impedance can result in radiated emissions, which may interfere with nearby circuits.
• Improves Power Transfer: In RF applications, maximum power is transferred only when the source and load impedance are equal.
• Enables High-Speed Communication: Interfaces like HDMI, USB, Ethernet, and LVDS require tight impedance control for proper function.

In short, impedance matching is critical to achieving predictable, reliable performance in complex circuits and high-speed digital or RF systems.

What Is Impedance Control?

Impedance control is the process of designing PCB traces so that their impedance remains within a specified tolerance, typically ±10%. This ensures signal transmission remains clean, reduces signal reflections, and avoids data loss or distortion—especially critical for USB, HDMI, high-speed memory, and RF circuits.

Why Is Impedance Control Important?

Controlled impedance becomes essential in high-frequency applications like:

• Communication equipment
• Medical devices
• Aerospace and defense electronics
• Consumer electronics
• Automotive systems

Signals traveling through improperly matched impedances can reflect back toward the source, leading to noise, jitter, and signal loss.

Common Types of PCB Impedance

Impedance isn’t a one-size-fits-all metric. There are different types, depending on signal configuration:

1. Single-Ended Impedance (Single-Ended Trace)

This refers to the impedance of a single signal line with respect to a reference plane (usually GND). This type is common in basic digital or analog signals.

Example: 50Ω impedance, line width of 5 mil on L1 referencing L2.

2. Differential Impedance

Used in differential pair routing where two lines carry equal and opposite signals (like in USB, HDMI). The impedance is measured between the two lines.

Example: 90Ω impedance, line width/spacing = 5/6 mil, referencing L2.

3. Coplanar Impedance

Here, the signal line is flanked by ground or power planes on the same layer, adding shielding and tighter impedance control.

• Single-Ended Coplanar Impedance: Signal line with ground on both sides.
• Differential Coplanar Impedance: Differential pair surrounded by ground on the same layer.

Example: 90Ω impedance, line width/spacing = 7.5/8/8 mil.

How Is Impedance Calculated?

Impedance is calculated using simulation tools that factor in geometry and material properties. The most commonly used tools include:

• Polar SI8000
• Polar SI9000

These tools allow engineers to model various stack-ups and design constraints to meet impedance targets.

• Common input parameters include:
• Trace width
• Trace spacing (for differential)
• Distance to reference plane (dielectric thickness)
• Dielectric constant (Dk)
• Copper thickness

Factors That Affect Impedance in PCB Design

Controlling impedance means adjusting several design parameters. Here’s how they influence impedance:

Factor	Effect on Impedance
Line width	Wider lines reduce impedance (inverse)
Line spacing	Narrower spacing lowers differential impedance
Dielectric thickness	Thicker dielectric increases impedance
Distance to nearby copper	Greater distance increases impedance
Dielectric constant (Dk)	Higher Dk reduces impedance
Copper thickness	Typically fixed; indirectly affects trace width needs

In practice, designers will tweak line width, spacing, and dielectric thickness to reach target values, since Dk and copper thickness are often constrained by material availability or cost.

Impedance Control Verification

Impedance control verification is the process of measuring and confirming that the actual impedance on the manufactured PCB matches the design specifications. This verification ensures that the board will perform reliably in the intended high-speed application. Here are some verify impedance control methods:

1. Test Coupons:

• Special trace structures are added to the edge of the production panel.
• These are manufactured using the same stack-up and process as the main board.

2. TDR (Time Domain Reflectometry):

• A signal pulse is sent through the test coupon trace.
• The equipment measures how the signal reflects along the trace to determine actual impedance.
• This method is non-destructive and very precise.

3. Report & Tolerance Check:

• The measured values are compared against target impedance (e.g., 50Ω, 90Ω).
• Typical tolerance is ±10%, depending on customer requirements.
• A formal impedance test report is provided.

4. Process Adjustments (if needed):

If values fall outside tolerance, manufacturers may tweak line width or dielectric thickness and re-run tests before final production.

Verifying impedance isn’t just a formality—it’s a guarantee that the board will function correctly in its application. Skipping this step can result in field failures, EMI issues, or complete communication breakdowns.

Why Choose Best Technology for Impedance-Controlled PCBs?

At Best Technology, we specialize in high-speed, high-reliability PCBs with precise impedance control. We use industry-standard impedance calculation software and fabricate test coupons to verify every impedance-controlled design. Whether you need simple 2-layer PCBs or complex HDI PCB stackups with tight tolerances, we provide:

• Competitive pricing
• Rigorous quality control
• Engineering support for stackup & impedance design
• Fast lead times

FAQs About Impedance Control

1. What is the typical tolerance for controlled impedance?

Most designs require ±10% tolerance from the target impedance value.

2. Do all PCBs require impedance control?

No, only high-speed or RF boards need impedance-controlled traces.

3. How do manufacturers verify impedance control?

They use test coupons and tools like TDR (Time Domain Reflectometry).

4. Can I use FR4 for impedance-controlled designs?

Yes, but its dielectric constant must be accounted for in calculations.

5. What happens if impedance isn’t controlled?

It can lead to signal reflection, data loss, and poor system performance.