EBest Circuit (Best Technology), your trusted PCB & PCBA manufacturer with over 19 years of industry expertise, is excited to return to New-Tech Israel 2025! After a successful participation last year, weâre back with even more innovative products and solutions. Weâd love to see you at our booth!
Date & Time:
As someone whoâs had the chance to participate in this event before, I can honestly say itâs one of the best opportunities to explore cutting-edge technology and network with industry experts. If youâre in the PCB, electronics, or manufacturing industries, this is a must-visit event!
Transparent/PI/Rubber Silicone Flexible Heating Films
Semi-Flexible PCBs & Bendable Aluminum PCBs
Ceramic Packages
Our experts will be available to provide in-depth insights on PCB assembly, covering everything from prototypes to low and high-volume production. Whether you need FPC, PCB, MCPCB, or Ceramic PCBs, weâre here to support your entire project with end-to-end servicesâfrom components sourcing to board fabrication, and even final assembly with programming and testing.
Our International Certifications
ISO 9001 (Quality Management System)
ISO 13485 (For Medical Device)
IATF 16949 (For Automotives)
AS 9100D (For Aerospace Parts)
At EBest Circuit (Best Technology), we take quality seriously. Our commitment to excellent quality is demonstrated by those international certifications we got!!!
Exciting News: Our New SMT Factory in Vietnam
May some friends missed out our post, we would like to emphasis again that weâve recently expanded with a new SMT factory in Vietnam! This expansion will allow us to offer even faster turnaround times, greater scalability for our PCB assembly services.
Canât Make It to the Event?
If youâre unable to attend in person but are still interested in learning more about our innovative products, weâd love to hear from you! Feel free to contact us directly for more information, product details, or a personalized consultation.
About New-Tech
The New-Tech Exhibition is the largest and major exhibition of the HiâTech & Electronics in Israel. More than 150 companies, who lead these fields in Israel and around the world, will take part and exhibit in this trade show.
This exhibition show featuring a comprehensive array of electronic components, production processes, subcontracting services, clean room equipment, electro-optic devices, test equipment, printed circuit boards, industrial materials, computerization solutions, robotics, power systems, RF/microwave technologies, and more. Attendees can explore cutting-edge innovations in development, design, engineering, and procurement across various industries.
Donât miss outâregister now and visit us at Booth 78 to see how EBest Circuit (Best Technology) can help you take your projects to the next level!
It is important to note:
1. Participation in the exhibition is conditional on prior registration, even for invited customers.
2. After registration and before the conference, a code will be sent to the mobile to confirm participation in the conference.
Have you ever wondered what powers your mobile phone behind the screen? Every tap, swipe, or call you make is possible because of one hidden hero: the mobile phone PCB. In simple terms, the mobile circuit board connects and controls all parts of your phone. It links the battery, screen, camera, processor, and even your wireless network. Without it, nothing would work.
At EBest Circuit (Best Technology), we design and manufacture custom mobile PCBs that support todayâs advanced smartphones. As a leading mobile PCB manufacturer both in China and Vietnam, we have decades years of experience in producing high-quality boards for mobile devices, wearables, and smart electronics. Certificated by ISO9001, IATF16949, ISO13485, AS9100D, it shows we have enough capability to produce highest quality mobile PCB board. Whether you need flexible, rigid, HDI, RF or multilayer PCBs, we deliver one-stop solutions with fast turnaround and competitive pricing.
What Is a Mobile Phone PCB?
A mobile phone PCB is the core of your smartphone, which drives your phone be intelligent. It looks like a green or black plate populated with many small electronic parts. These components are connected through thin copper lines etched onto the board. Together, they power your phone and make sure each part works smoothly.
In smartphones, the PCB board mobile phone is usually a multi-layer board, meaning it has several layers stacked together. This design helps save space and supports high-speed data processing. The PCB also holds all essential parts like the processor, memory, charging port, and wireless chips.
What Does a Mobile Phone PCB Actually Do?
A mobile phone PCB acts like the brain and nervous system, it mainly used to connect and manage every part of the phone, its working principle is:
Power distribution: It sends power from the battery to other parts.
Signal transmission: It lets the processor talk to the screen, camera, and sensors.
Component support: It holds everything in place and keeps them working together.
Without the mobile phone PCB, the battery wouldnât know how to charge, the screen wouldnât respond, and the speaker wouldnât play music. It handles all the behind-the-scenes activity while you use your apps and make calls.
Core Components on a Mobile Phone PCB
A mobile phone PCB always is a populated PCB. At the top of the PCB, youâll find the antenna point, where the antenna connects. Your phone connects to Wi-Fi, Bluetooth, and cellular networks through these antennas. Each component on the PCB plays its unique role:
Antenna Switch: A 16-leg switch that controls signal direction. Sometimes built together with the PFO.
PFO (Power Frequency Oscillator): Manages signal frequency. Found next to the antenna switch.
Network IC: Controls mobile network functions. In some phones, it’s built into the CPU.
Power IC: Found near brown capacitors. Regulates power across the PCB.
CPU (Processor): The largest IC. Handles all system commands and performance tasks. Some phones have two CPUs.
Flash IC: Stores system data and software. Located beside the CPU.
Logic IC: A 20-pin chip. Manages basic logic operations.
Charging IC: Found beside R22. Controls battery charging.
Audio IC: Controls sound functions. Placed close to the Power IC.
Capacitors: Store and release electrical energy. Help stabilize power supply.
Resistors: Control the flow of current. Protect other parts from too much power.
Diodes: Allow current to flow in one direction only. Prevent power damage and signal errors.
Below is a multi-layer PCB used in iphone. These parts make it possible for you to browse, take photos, and connect with the world.
Why Multi-layer PCBs Are Standard in Smartphones?
Todayâs smartphones are like mini computers. They handle everything from streaming video to running powerful apps. To keep up, mobile phone PCB design has evolved. One of the biggest upgrades? The switch to multi-layer PCBs. Here we listing main advantages of using multi-layer PCBs in mobile phone.
Firstly, multi-layer PCBs offer higher circuit density, allowing more components like processors and memory to fit in the limited space. For example, the iPhone 14 Pro uses a 10-layer PCB to deliver powerful functionality in a compact design.
Secondly, they improve high-speed signal transmission by reducing interference through ground and shielding layers, ensuring stable and fast data transferâa must for modern smartphones.
Additionally, multi-layer PCBs reduce the size and weight of smartphones. By accommodating more circuits in the same area, they help achieve smaller, lighter designs, like in the Apple Watch Series 8.
Finally, multi-layer PCBs enhance reliability and mechanical strength. Their complex construction improves durability and vibration resistance, ensuring a longer-lasting product.
How Inner and Outer Layers Interact in a Mobile PCB Stack?
In a mobile PCB board, the inner and outer layers work together like a team. The outer layers handle the connection of chips, antennas, and components you can see. Meanwhile, the inner layers manage signal traces, power distribution, and ground planes.
Signals often travel between these layers through viasâsmall holes filled with metal that link one layer to another. This allows for faster, cleaner communication between the mobile PCB components, such as the CPU, RAM, and radio circuits.
Materials Used in Mobile PCB Board
Choosing the right materials is crucial in mobile phone PCB manufacturing. Each layer and part of the board serves a different purpose, so engineers carefully select materials to match performance needs, durability, and size constraints. Hereâs a comparison of commonly used mobile PCB materials:
Material
Description
Pros
Common Use in Mobile PCB
FR4
Fiberglass-reinforced epoxy laminate
Cost-effective, stable electrical properties
Base material in most mobile PCB cores
Polyimide
Flexible and heat-resistant material
Great for flexible PCBs and foldable applications
Used in camera modules, folding phones
Rogers
High-frequency laminate
Low dielectric loss, excellent RF performance
Antenna sections, 5G, Wi-Fi, Bluetooth
Teflon (PTFE)
Non-stick, high-performance polymer
Ultra-low signal loss, ideal for high-speed signals
Used in high-speed communication layers
Ceramic
Advanced inorganic composite
Excellent heat dissipation, high frequency stability
Power modules, 5G RF front-end, shielding
PCB Layout Basics for Mobile Phones
A solid layout is the backbone of any mobile phone PCB. Designers start with the schematic, which maps every component and connection. Mobile PCB layout focuses on a few key goals:
Short signal paths to avoid delay.
Clear power and ground planes for stability.
Thermal zones to manage heat.
Shielded areas for RF sections like Wi-Fi and GSM modules.
Placing the processor, RAM, power management ICs, and antennas carefully prevents problems later.
Warm tips:
Keep power and ground layers as solid planes. Avoid breaks or thin sections, which create voltage drops. Also, decoupling capacitors should sit close to power pins of chips.
Tips for GSM, Wi-Fi, Bluetooth, and 5G Mobile PCB Antennas
Keep antennas away from metalâmetal blocks signals.
Use ground clearance around antenna traces to reduce noise.
Match impedance of the RF trace to avoid reflection.
Add shielding near high-speed digital lines to prevent signal loss.
For 5G, which uses millimeter-wave bands, the routing must be super precise. Even a few millimeters can affect signal strength. Tools like electromagnetic simulation software help refine these paths.
How AI and Automation Are Changing PCB Layout?
AI and automation have brought big changes to mobile PCB design in this two year. Instead of placing parts manually, designers can now rely on smart layout tools that optimize paths automatically. Machine learning predicts optimal routing paths. Automation assists in component placement, thermal analysis, and EMI reduction. They suggest better placements in secondsâsaving hours of work.
AI also speeds up mobile PCB testing. It spots defects on boards using image recognition. That means more accurate inspections, less rework, and faster production.
As AI tools improve, theyâll continue to reduce errors, cut costs, and deliver better mobile board designs. It’s a leap forward for the industry.
What Does EBest Circuit (Best Technology) Serve You?
At EBest Circuit (Best Technology), we provide complete solutions for mobile PCB design and manufacturing. Whether you’re developing a new smartphone, tablet, or wearable device, we help you build it from the ground up. Our services including but not limited to:
Custom mobile phone PCB layout and design based on your needs
Single-layer to 32+ layer boards, including HDI, rigid-flex, and high-frequency options
Advanced material selection such as FR4, polyimide, Rogers, and BT epoxy
Rapid prototyping and small-volume production with quick delivery
Full testing services like AOI, flying probe, impedance, and X-ray inspection
With over 18 years in the PCB industry, weâve supported top-tier brands in building reliable, high-performance mobile electronics. Our team works closely with customers and give the best suggestions to optimize your mobile circuit board design. If you are interested in the mobile PCB develop, you are welcome to contact our team at sales@bestpcbs.com.
FAQs
1. What does a mobile phone PCB diagram show?
It shows where each component is placed on the board and how they are connected through copper traces.
2. How can I avoid power issues in PCB layout?
Use ground planes, short power paths, and place capacitors close to chips for voltage stability.
3. How do I identify damaged parts on a mobile PCB?
Use thermal cameras, multimeters, and reference schematics to locate shorted, burned, or faulty components.
4. What makes EBest Circuit (Best Technology) a strong mobile PCB manufacturer?
They provide full-stack design-to-production all in one service, expert engineering support, DFM check, SI, PI analysis and a proven track record in mobile electronics.
Fiberglass circuit board is the backbone of todayâs electronics. These boards support and connect components in almost every electronic device, from consumer gadgets to industrial control systems. Unlike ordinary materials, fiberglass brings strength and stability. It holds up well under heat, resists moisture, and stays firm under mechanical stress.
What Are Fiberglass Circuit Boards?
A fiberglass circuit board is a type of printed circuit board (PCB) made using a base material reinforced with glass fibers and resinâtypically epoxy. This combination results in a strong, heat-resistant, and electrically stable platform used to mount and interconnect electronic components.
Also called printed circuit board fiberglass, these boards dominate the electronics industry thanks to their durability and consistent performance. From mass-produced gadgets to high-end machinery, fiberglass boards provide the structural and electrical backbone that keeps everything working smoothly.
What Are Fiberglass Boards Made Of?
Fiberglass boards are made from fine strands of glass spun into a fabric. This fabric, typically known as glass cloth, is then saturated with epoxy resin. Once hardened, the composite becomes the core insulating layer in a fiberglass circuit board.
The most common material is FR4. It includes:
Woven E-glass (Electrical-grade glass): Provides electrical insulation and dimensional stability.
Epoxy resin: Bonds the glass fibers and maintains structure under thermal stress.
Copper foil: Laminated onto one or both sides to create electrical pathways.
Together, these elements create an electrical fiberglass board that is tough, heat-resistant, and non-conductive at its core.
Types of Fiberglass Circuit Boards
Fiberglass circuit boards arenât one-size-fits-all. They come in multiple variations to meet different design and performance needs. Whether you’re designing a basic remote control or a complex radar module, there’s a fiberglass board fit for the job.
Single Layer Fiberglass Circuit Board
This is the most basic type. It has copper traces on only one side of the board. Itâs often used in low-cost consumer electronics, LED lights, and household appliances. Despite its simplicity, the fiberglass circuit board structure keeps it durable and stable.
Double Layer Fiberglass Circuit Board
With copper layers on both sides and vias connecting them, this board offers more routing space and better performance. Itâs a popular choice for audio equipment, industrial sensors, and power supplies. These boards balance cost with performance and are widely produced by fiberglass circuit board manufacturers worldwide.
Multilayer Fiberglass Circuit Board
These contain three or more layers of fiberglass and copper laminated together. They are essential for smartphones, routers, and advanced computing devices. With increased layer count comes better signal control and component density.
HDI Fiberglass Circuit Board
High-Density Interconnect (HDI) boards pack more functionality into smaller areas. They use microvias, blind vias, and fine lines to boost performance without increasing board size. HDI designs often use printed circuit board fiberglass materials for strength and tight tolerances.
High Frequency Fiberglass Circuit Board
For RF or microwave applications, standard fiberglass isnât always enough. Specialized fiberglass composites with low dielectric loss are used. These boards are perfect for radar systems, antennas, and satellite communication.
Rigid-Flexible Fiberglass Circuit Board
Combining rigid fiberglass sections with flexible polyimide layers, these hybrid boards offer both structural support and flexibility. Theyâre widely used in wearables, military electronics, and compact medical devices.
Features of Using Fiberglass Circuit Board
Fiberglass circuit boards offer several unmatched advantages. These features help explain why theyâre so common in nearly every electronic product.
Thermal Stability: Fiberglass holds up well under heat. It wonât warp or delaminate under typical operating conditions.
Dimensional Stability: Even in humid or fluctuating environments, the board keeps its shape.
Electrical Insulation: The glass fibers prevent current leakage and minimize signal loss.
Mechanical Strength: These boards donât crack easily. They can take a beating during assembly or usage.
Low Fiberglass Board Price: Compared to ceramics or PTFE substrates, fiberglass board price is much lowerâwithout major performance tradeoffs.
Why Is Fiberglass Used in Motherboards?
Motherboards are the nerve center of any computing device. They require a substrate thatâs flat, stable, and electrically inert. Fiberglass checks all those boxes. Its woven glass core resists bending and warping over time, ensuring that pins, sockets, and solder joints stay aligned. It also helps dissipate heat generated by processors and other high-power components.
Motherboards also demand multi-layered structures. Only multilayer fiberglass circuit boards can deliver the routing density needed for complex connections between CPU, RAM, GPU, and other modules. That’s why fiberglass remains the default material for virtually all desktop and laptop motherboards.
What Is Fiberglass Board Used For?
Beyond motherboards, electrical fiberglass boards are everywhere:
Consumer Electronics: Smartphones, TVs, game consoles.
Thanks to their adaptability and performance, fiberglass boards can be customized for nearly any electrical task. This is why fiberglass circuit board manufacturers remain in high demand globally.
Why Is Fiberglass Hazardous?
Though highly useful, fiberglass isnât without precautions. During manufacturing, cutting or sanding fiberglass can release microscopic glass particles. These can irritate the skin, eyes, and respiratory system. Thatâs why workers must wear protective gear in production settings.
However, once the board is sealed and installed, it poses minimal risk. Finished electrical fiberglass boards are stable, safe, and inert under normal use conditions. They do not emit toxins or degrade during product life.
Is Glass Fiber the Same as Fiberglass?
Technically, yesâglass fiber and fiberglass refer to the same material. âGlass fiberâ usually describes the raw filament or strands. âFiberglassâ refers to the composite made from glass fibers and resin.
In PCB manufacturing, the terms are often used interchangeably. Whether you say printed circuit board fiberglass or glass fiber PCB, the meaning remains consistent: a reliable, heat-resistant circuit platform. While the terms are related, in practice, fiberglass is the final product used in PCBs, not just the raw glass fiber.
FAQs
Q1: Is fiberglass better than FR2 in circuit boards?
Yes. Fiberglass (FR4) offers higher strength, better insulation, and improved heat tolerance compared to FR2 paper-based boards.
Q2: How much does a fiberglass board cost?
The fiberglass board price varies by layer count, size, and copper thickness. Single-layer boards may cost less than $1 per piece, while multilayer HDI boards are higher.
Q3: Can fiberglass circuit boards handle high power?
Yes. With proper copper thickness and thermal management, fiberglass PCBs handle moderate to high power loads reliably.
Q4: Are fiberglass boards environmentally friendly?
Most are ROHS-compliant. However, disposal must be handled properly due to the epoxy content.
Q5: Who are top fiberglass circuit board manufacturers?
Top producers include EBest Circuit (Best Technology), TTM Technologies, and PCBWay. Look for ISO-certified factories with full in-house fabrication.
Whether you’re building a simple LED board or a complex communication device, printed circuit board fiberglass options are there to support your design.
Looking for a trustworthy partner to supply high-quality fiberglass PCBs? EBest Circuit (Best Technology) has more than 18 years of experience manufacturing standard and custom circuit boards, including single to multilayer designs, HDI, and high-frequency variants. Our in-house production facilities are ISO9001, IATF16949, AS9100D and UL certified, ensuring that every board meets global quality standards. We pride ourselves on delivering fast lead times, customized solutions, and exceptional technical support that help our clients stay ahead in an ever-evolving market.
A copper foil PCB is a type of printed circuit board where copper foil is laminated onto the base material to form the conductive layer. This copper layer is what carries electrical signals and power between different parts of the board. Without it, a PCB wouldnât function at all.
The copper is typically applied through lamination, where thin sheets of copper foil are bonded to a substrate, usually made of fiberglass-reinforced epoxy resin like FR4. This copper layer is then etched to create precise paths, known as traces, that connect components across the board.
There are also different thicknesses of copper foil used, which affect the boardâs ability to carry current and dissipate heat. The standard thickness is usually 1 oz/ftÂČ (about 35ÎŒm), but heavier copper options like 2 oz or 3 oz are often used in power electronics or high-temperature applications.
What is the Purpose of Copper Foil in PCB?
The main role of copper foil is to carry electric current across the circuit. It’s the path for data, signals, and energy. Without copper foil, there would be no communication between components.
Besides that, copper foil helps in thermal transfer. When current flows, heat is generated. Copper helps in spreading this heat evenly, reducing hot spots. Thatâs key in designs with dense parts or power-hungry chips. Also, copper layers add mechanical strength to the board, supporting solder joints and reducing flex.
What are the Different Types of Copper Foils?
Copper foil types vary based on how they’re made, how rough they are, and what kind of performance they offer in real PCB applications. Choosing the right type can make a big difference in signal clarity, layer adhesion, and long-term reliability. Letâs see the most common types used in the PCB industry:
1. Electrodeposited (ED) Copper Foil
Electrodeposited copper foil is the most widely used type in standard rigid PCBs. Itâs made through an electrochemical process where copper ions are deposited onto a rotating stainless steel drum. The side in contact with the drum becomes smooth, while the other side is naturally rough.
ED copper foil is great for multilayer rigid boards, consumer electronics, and automotive circuits. When treated with surface chemicals, it bonds well to laminates and resists layer separation.
2. Rolled Annealed (RA) Copper Foil
RA copper foil is made by mechanically rolling solid copper into very thin sheets and then annealing it (heating and cooling) to relieve stress. Youâll find RA copper in flex circuits, flex-rigid PCBs, wearable electronics, and mobile devices. When boards must flex without breaking, RA is the go-to.
3. Reverse Treated Foil (RTF)
RTF is a type of ED foil where the shiny side is treated instead of the rough side. This treatment adds micro-etching or chemical bonding to enhance adhesion between the copper and the laminate. RTF is popular in HDI (High-Density Interconnect) boards, high-speed digital circuits, and RF designs where signal loss must be controlled.
4. Very Low Profile (VLP) and Ultra-Low Profile (ULP) Copper Foils
These are smoother versions of standard ED foils, created to reduce conductor roughness. VLP and ULP foils are still electrodeposited, but they go through extra steps to minimize surface peaks and valleys. They are used in high-speed digital systems, data centers, 5G antennas, and any application where clean signal transmission matters.
5. High-Temperature Elongation (HTE) Copper Foil
HTE copper foil is a variant of ED copper, enhanced for high thermal and mechanical stress. It resists cracking under repeated heating and cooling cycles. HTE is preferred for automotive, power electronics, and multilayer PCBs that go through reflow soldering or see high current loads.
6. Resin-Coated Copper Foil (RCC)
RCC combines copper foil with a thin layer of resin. This resin bonds directly to the core without needing prepreg sheets, which simplifies the lamination process. Mainly in mobile phones, compact devices, or where thin layers and high accuracy are needed.
Here is a summary comparison table between them:
Copper Foil Type
Strength
Flexibility
Smoothness
Signal Performance
Application
ED
High
Low
Moderate
Standard
Rigid PCBs
RA
Medium
High
High
Good
Flex PCBs
RTF
High
Medium
Treated
Excellent
RF, HDI
VLP/ULP
Medium
Medium
Very High
Superior
5G, high-speed
HTE
Very High
Low
Moderate
Standard
Power boards
RCC
Low
Medium
High
Good
Thin mobile boards
What is the Roughness of Copper Foil in PCB?
âThe roughness of copper foil on PCB â refers to the unsmoothness of the copper foil surface, Copper foil roughness affects how well signals move through the board. In high-speed designs, surface texture matters a lot. Rough copper increases insertion loss. This weakens the signal and causes noise.
Roughness is usually measured in microns, which is usually quantified by Ra, Rz and Rq. Lower values are better for RF or high-speed data.
âRaâ: The arithmetic average of the absolute value of the contour deviation over the sampling length, applicable to copper foil surface.
âRzâ: Sum of the average of the 5 largest profile peak heights and the average of the 5 largest profile valley depths over the sampling length for copper foil rough surface.
âRqâ: Means RMS (Root means square) value, it also is a roughness index.â
PCB Copper Thickness Chart
Copper thickness is often given in ounces per square foot. But that doesnât mean much until you convert it. Here’s a helpful chart:
Copper Weight (oz/ftÂČ)
Thickness (”m)
Thickness (mil)
0.5 oz
~17 ”m
~0.67 mil
1 oz
~35 ”m
~1.37 mil
2 oz
~70 ”m
~2.74 mil
3 oz
~105 ”m
~4.11 mil
4 oz
~140 ”m
~5.48 mil
For single & double sided PCB, the copper foil thickness is about 35um, 50um, 70um;
For multi-layer PCB, its outer layer copper thickness is 35um, and inner layer copper thickness is 17.5um (1/2oz).
Designers choose copper weight based on current flow and thermal limits. Thicker copper is used in power PCBs. Thinner layers are more common in signal circuits or HDI boards.
HTE vs RTF copper foil
When it comes to choosing the right copper foil for high-performance PCBs, HTE (High-Temperature Elongation) and RTF (Reverse Treated Foil) are two of the most commonly used options.
HTE Copper Foil
HTE copper foil is a specially processed electrodeposited foil thatâs engineered to handle high thermal and mechanical stress. The term “high-temperature elongation” refers to the foilâs improved flexibility and stretch resistance when exposed to heat.
Itâs treated chemically to improve adhesion strength, making it more reliable during multiple soldering cycles. The surface has a consistent profile that bonds well with different dielectric materials.
Key Features of HTE Foil:
Strong peel strength
Durable under repeated heating
Excellent for plated-through-hole (PTH) reliability
Withstands lamination and solder reflow cycles
RTF Copper Foil
RTF, or Reverse Treated Foil, is also made through an electrodeposition process, but with one key difference: the shiny side gets treated instead of the rough side. This treatment applies a fine, uniform microstructure that enhances bonding without creating high surface roughness.
This smoother surface makes RTF a preferred option in high-speed signal and RF PCB applications where low signal loss is critical.
Key Features of RTF Foil:
Lower surface roughness
Better electrical performance at high frequencies
Improved signal integrity
Balanced peel strength and performance
PCB Copper Electrical Conductivity
Copper has one of the highest electrical conductivities of any metal. Thatâs why itâs the go-to choice for PCBs. The typical conductivity of copper used in PCBs is about 5.8 x 10â· S/m (Siemens per meter).
This high conductivity allows small traces to carry high current with low voltage drop. It also reduces signal distortion, which is key in high-speed or RF applications.
Still, conductivity depends on purity. Most PCB foils use 99.9% pure copper. If copper is oxidized or poorly handled, conductivity drops. That’s why clean processes and proper lamination are important.
How to Calculate Copper Thickness in PCB?
The thickness of copper in PCB can be calculated by the following methods:
1. Calculation of copper plating thickness by current density and plating time:
Plating thickness (um) = current density (ASF) x plating time (min) x plating efficiency Ă 0.0202â. This formula takes into account the amount of electricity, equivalent, molar mass, density and other factors. The specific calculation process involves the product of current density, plating time and plating efficiency, then multiplying by a factor 0.0202â.
â2. Thickness calculated by weight of copper foil:
In the common option “copper-covered FR4, single-sided,1 oz”,1 oz indicates the thickness of the copper foil. 1 oz = 28.35 g/ftÂČ, copper foil density of 8.93 g/cmÂł, 1 square foot = 929.03 cmÂČ. Thus, 1 oz copper foil thickness = 28.35/8.93/929.03 â 35um or 1.35mil â. Common PCB thicknesses include 1/2Oz = 17.5um, 1 oz = 35um, 2oz = 70um, and 3 oz = 105um.
1. Isola Group:Known for high-frequency and low-loss materials.
2. Kingboard: One of the worldâs biggest copper clad laminate suppliers.
3. Ventec International: Offers low-profile copper foils and thermal substrates.
4. Mitsui Mining & Smelting: A top name in RTF and ultra-smooth foils.
5. EBest Circuit (Best Technology): Based in Asia, with 18+ years in the industry. We supply high-quality copper foil PCBs, from 0.5 oz to over 6 oz.
At EBest Circuit (Best Technology), we bring over 18 years of hands-on experience. We support standard and custom copper weights, including heavy copper for high-current boards. Our RTF and HTE options fit both signal-sensitive and power-heavy needs.
With fast lead times, in-house testing, and global delivery, weâre more than just a PCB maker. Weâre your reliable partner for copper foil PCB solutions. Reach out today to explore your next project with confidence.
A fast turn PCB board is a printed circuit board manufactured and delivered in a short time, typically within 24 to 72 hours. These quick deliveries help speed up product development, especially during prototyping and pre-production stages. Itâs a solution many engineers rely on when time is tight.
Engineers use fast turn PCBs for product validation. They want to see if a new circuit design performs well before moving to mass production. So, getting a board in days instead of weeks can make a huge difference.
First, it speeds up your product timeline. You don’t need to wait weeks to test your circuit. If changes are needed, you can get a revised board quickly and keep things moving forward.
Second, it helps reduce project risks. The faster you test, the faster you detect potential design errors. Early detection saves money and prevents delays.
Third, it improves decision-making. With working samples in hand, your team can test real performance. Itâs better than guessing or using simulation data only.
Lastly, fast turn options give your company a competitive edge. Getting to market faster often means better sales and stronger customer trust.
EBest Circuit (Best Technology)âs Typical Turnaround Time for Fast Turn PCBs
At EBest Circuit (Best Technology), we understand the value of time. Thatâs why weâve optimized our process to support urgent PCB orders.
For standard 2-layer fast turn PCBs, we usually deliver in 24 to 48 hours. For 4-layer boards, it may take 48 to 72 hours depending on complexity. Our team works around the clock to meet those deadlines.
Even for more complex boards â such as HDI or metal-core PCBs â we still maintain one of the quickest turnaround times in the industry. And we donât compromise on quality. Each board goes through full inspection and electrical testing before it reaches you. The detailed turnaround time is:
Prototype(<1mÂČ)
Layers
Normal Service
Expedited Service
FR4 PCB
1 Layer
3-4 days
24 hours
2 Layers
4-6 days
24 hours
4 Layers
8-10 days
48 hours
6 Layers
8-10 days
72 hours
8 Layers
10~14 days
72-96 hours
10 Layers
14-18 days
72-96 hours
HDI (1+N+1 2+N+2)
2.5 â 3.5weeks
TBD (depend on design)
We donât just print boards fast. We manage the process with strict planning, from materials to delivery. Thatâs why so many clients come back to us for every new project.
Factors That Affect the Turnaround Time of Prototypes
Even though we push for speed, several factors can influence how long a fast turn circuit board takes to produce. Knowing these helps avoid delays.
Circuit Board Design and Test Procedures
The design stage impacts everything. A simple, well-structured layout speeds up processing. Complex routing, fine-pitch components, or tight spacing can add extra review time.
Test procedures matter too. If a special test is needed, like impedance control or functional test setup, it adds to the schedule. Providing clear instructions in advance helps us prepare and avoid delays.
Lamination Cycles
For multilayer boards, each lamination cycle takes time. A 4-layer multi-layer board needs one cycle, while an 8-layer may need several. More layers mean longer pressing times and more careful control.
Quick builds still go through these steps. We just start immediately and plan shifts to manage it faster. Thatâs why sharing the full stack-up early is so important.
Via-in-Pad Plated Over
Via-in-pad designs are helpful for high-density layouts. But they add a few extra steps in production. We need to drill, plate, and fill those vias carefully. After that, we cap and flatten them before plating the surface.
This extra effort adds time compared to standard vias. If your board uses VIPPO, itâs best to let us know upfront so we can fast-track these processes.
Fabrication Drawing Specifications
Precise drawings help avoid back-and-forth communication. If drawings are unclear or missing details like dimensions, tolerances, or hole types, weâll need to clarify before production.
Clear drawings lead to fast fabrication. They also reduce the risk of mistakes. Thatâs why we suggest using IPC-2581 or Gerber X2 format with notes included.
Surface Finish
Surface finish choice also plays a role. ENIG, OSP, HASL, or hard gold all have different process times. For example, ENIG takes longer than HASL because it involves two plating steps.
If speed matters most, we can recommend the best finish based on your needs. Some finishes can still meet performance goals while shaving off hours from the process.
Assembly Drawings and Notes
If you also need PCB assembly, complete documentation is key. Missing part placements, unclear polarity marks, or unreferenced BOM items slow everything down.
Providing all files in one goâBOM, pick and place, centroid file, and notesâhelps avoid delays. When everythingâs ready, our SMT line can move fast and precise.
Fast Turn Circuit Board Manufacturing
Manufacturing a fast turn circuit board isnât about rushing. Itâs about knowing how to work smart, reduce waste, and prevent rework.
At EBest Circuit (Best Technology), we keep a reserve stock of core materials and prepreg. That way, we can start production immediately without waiting for supply.
We also use automatic routing, inline AOI, and robotic drilling machines to keep operations smooth. Our teams work in shifts, so production doesnât stop, even at night or on holidays.
Every department is synchronized. CAM engineers review your files fast, material control prepares the stack-up, and QA teams check every step. Thatâs how we manage fast output without losing accuracy.
We also run a parallel system for urgent jobs. These special jobs go into our âfast-laneâ line, separated from standard orders. This ensures time-sensitive boards donât get stuck behind large-volume orders.
Why Should You Choose EBest Circuit (Best Technology) as Your Preferred Partner?
Choosing a fast turn PCB partner isnât just about delivery speed. Itâs about trust, communication, and consistent results. EBest Circuit (Best Technology) stands out because we offer more than just fast service.
Experienced team: Weâve been in this field for over 18 years. Our engineers know what works and how to prevent problems early.
Clear communication: Our team responds quickly. We give you updates, clarify questions, and solve problems before they become delays.
Flexible production: Whether you need 1 board or 10,000, we scale easily. We also support special needs like rigid-flex, metal core, or ceramic boards with fast turn options.
Global shipping: We work with trusted logistics partners. Boards reach you safely and on time, even across borders.
Reliable quality: Every board goes through full inspection, AOI, flying probe, and E-test. Even fast jobs go through our strict quality checks.
When you work with EBest Circuit (Best Technology), you get speed, support, and security in every step. Thatâs why companies in medical, industrial, and automotive industries continue to rely on us.
EBest Circuit (Best Technology) is your trusted partner for comprehensive PCB solutions â from initial concept to final product. With over 18 years of experience, we offer one-stop services that cover the full PCB lifecycle, ensuring high quality, fast turnaround, and competitive pricing. Why customers prefer us:
Free DFM/DFA check
Free Design Guideline
25,000m2 production capacity
2 Hours quick response
Quote within 12 hours
Online support 24/7
Transparent order tracking from first day to final delivery
Military-grade quality boards with strict testing and IPC standards
One-stop services from layout to turnkey assembly
Engineering support to optimize your design for performance and cost
Whether youâre a startup building your first prototype or a large OEM scaling up production, EBest Circuit (Best Technology) is your reliable PCB partner.
Our Core Services – From Design to Assembly
We provide a wide range of services to support your project at every stage:
PCB Design & DFM Check – We donât just manufactureâwe help you build better boards. Send us your layout or concept, and our senior engineers will review your files for manufacturability, improving your design before it hits the production line.
PCB Fabrication – Single-layer, multi-layer, HDI, aluminum-based, or ceramicâwe fabricate PCBs of all complexities. Our in-house plant supports quick turnarounds and strict quality control for every batch.
PCB Prototype – Need your prototype in 24â72 hours? Weâve got your back. Ideal for engineers in the development phase, we offer fast PCB prototyping with full traceability, fly-probe testing, and surface finish options.
PCB Assembly – Our turnkey PCB assembly service covers everything from component sourcing, SMT/DIP soldering, to functional testing. You send us your BOM and Gerberâwe handle the rest.
IC Programming â Pre-programming and testing of integrated circuits to streamline your assembly process.
What PCB Types Does EBest Circuit (Best Technology) Manufactured?
We are capable of manufacturing a wide variety of PCB types, including but not limited to:
FR4 PCBs (high speed PCB, IC substrate, high TG PCB, extra thin PCB, our special semi-rigid flex PCB and so on.)
Metal Core MCPCBs (aluminum based PCB, copper clad PCB, sinkpad PCB, thermoelectric copper separate PCB)
Ceramic PCBs (AlN, BeO, AlâOâ, Zro2)
Flexible and Rigid-Flex PCBs, FFC, Dual access PCB
HDI PCBs
High-Frequency PCBs
Heavy Copper PCBs
Busbar PCBs
Hybrid Substrate PCBs
Whether you need high-reliability boards for aerospace, thermally conductive boards for LEDs, or RF boards for communication devices, we have the capability to deliver.
PCB Prototype Lead Time
We understand how crucial speed is in product development. Our standard PCB prototypelead time is:
Single-layer & double-layer PCBs: as fast as 24 hours
4-layer PCBs: typically 48â72 hours
6-layer or above: around 3â5 working days, depending on complexity
Below is a detailed prototype lead time sheet at EBest Circuit (Best Technology), the expedited options are available to meet urgent project deadlines.
Battery corrosion happens mostly with alkaline batteries. These batteries can leak potassium hydroxide. This chemical reacts with air, forming a white or bluish crust. That crust is the corrosion you see.
There are a few reasons why this happens. Old batteries left inside devices too long can leak. Extreme heat or cold can also make them expand and crack. Sometimes, poor-quality batteries just break down faster. Corrosion doesnât mean the battery was faulty. But it does show that the battery has aged or faced rough conditions.
Some other causes include:
Overcharging or overheating: In devices that try to draw too much power, batteries can heat up and burst.
Poor storage conditions: Dampness or extreme cold can stress the battery casing.
Mixing old and new batteries: This creates uneven discharge, often stressing the older cell until it leaks.
Is Battery Corrosion Dangerous?
Yes, but only if youâre careless. Battery corrosion is not highly dangerous, but it can still be irritating if it gets on your skin or in your eyes. Potassium hydroxide is a skin irritant. It may cause mild burns, itching, or redness if touched directly. If accidentally ingested or inhaled, it can be more harmfulâbut thatâs rare and usually avoidable.
In terms of your electronics, corrosion is more dangerous. The leaked compound can damage the metal connectors inside your device. If left untreated, it might eat away the contacts, cause shorts, or completely block the flow of power. That means your device might stop working even after the batteries are replaced.
However, with quick action, most devices can be restored to working condition. As long as you catch the corrosion early and clean it properly, thereâs a good chance your device will recover fully.
How to Identify Corrosion on Batteries?
Battery corrosion usually appears as white, gray, or blue powder by visual. Youâll see it around the battery terminals or on the spring contacts. Sometimes, the battery might look bloated or cracked. But sometimes, we canât identify whether it is corrosion from appearance, so how to identify it? Here we listing some other methods to recognize the battery corrosion:
â1. Electrochemical testâ: By measuring the electrochemical parameters inside the battery, such as voltage, current and internal resistance, the degree of corrosion inside the battery can be indirectly inferred. â
2. X-ray or CT scanâ: This is a non-destructive detection method that can perform a full-scale scan and imaging of the inside of the battery without disassembling the battery, and can clearly see the corrosion inside the battery, including the location, degree and type of corrosion. â
3. Check the polarity of the batteryâ: Observe whether the positive and negative poles of the battery are clearly visible and whether there are signs of corrosion or damage. If the positive and negative poles are corroded or damaged, the battery may be unusable. â â
4. Measure voltageâ: Use a voltmeter to measure the battery voltage. Under normal circumstances, the voltage should be within a certain range (such as around 12V). If the voltage is lower than the normal value, it means that the battery is damaged.
5. Measure specific gravityâ: Determine the battery health by measuring the specific gravity of the battery electrolyte. The normal specific gravity is about 1.25-1.28g/cmÂł. If the specific gravity is lower than 1.2g/cmÂł, it means that the battery is damaged. â
6. Discharge testâ: Evaluate the actual capacity of the battery through the discharge test. Discharge the battery to the specified termination voltage, and then calculate the actual capacity of the battery based on the discharge time and capacity. â
What is the Best Solvent to Clean Battery Corrosion?
The most trusted solvents are white vinegar and lemon juice. Theyâre safe, gentle, and effective. These mild acids react with the potassium hydroxide and break it down. You donât need harsh chemicals or expensive products.
Some people also use baking soda and water for acidic battery leaks, like those from lithium or rechargeable cells. But for most alkaline batteries, vinegar works better.
Avoid using alcohol or bleach. These donât neutralize the leak and might damage plastics. Always test the solvent on a small area first.
How to Remove Battery Corrosion from PCBs?
Removing battery corrosion from PCBs takes a bit more care than cleaning corrosion from regular battery compartments, mainly because PCBs are more sensitive and often house fine components. Hereâs a simple, professional, and safe way to clean corrosion from a PCB:
1. Power Down and Disconnect
First, completely power off the device. Disconnect all power sources, including batteries, power cords, and any external peripherals.
2. Wear Gloves and Safety Gear
Battery corrosion contains potassium hydroxide (alkaline batteries) or other chemical residues that can irritate skin or eyes. Use gloves, goggles, and work in a well-ventilated area.
3. Inspect the Corrosion Area
Look closely at the board under good lighting or even a magnifier. Corrosion usually appears as white or greenish deposits on the metal traces or battery terminals.
4. Neutralize the Corrosion
Use white vinegar or lemon juice to neutralize alkaline corrosion.
Apply it carefully with a cotton swab or soft brush directly on the affected area.
Let it sit for 3â5 minutes to break down the residue.
5. Scrub Gently
Use a soft-bristled toothbrush or anti-static brush to scrub the area. Be gentleâtoo much pressure can lift pads or traces from the PCB.
6. Rinse with Isopropyl Alcohol
After cleaning, rinse the area with 99% isopropyl alcohol to remove moisture and leftover acid. This step helps clean off the vinegar/lemon juice and dries quickly.
7. Dry Thoroughly
Pat the board dry with a lint-free cloth or allow it to air-dry. Use compressed air to blow out moisture under chips or between components.
8. Check for Damage
Look for broken traces, lifted pads, or corrosion under components. If corrosion went deep, you might need professional rework or replacement parts.
9. Reassemble and Test
Once youâre sure everythingâs dry and clean, reassemble the board, add a fresh battery (if applicable), and power it up. In many cases, your board will work just fine again.
Can I Still Use Something If a Battery Corroded in It?
Often, yes. If the corrosion hasnât spread too far, you can save the device. Most electronics are still fine once cleaned properly. The key is to act fast. The longer corrosion sits, the more damage it causes.
If contacts are lightly corroded, cleaning will fix it. But if theyâre broken or rusted through, repair might be needed. Sometimes, replacing a contact spring is all it takes.
Check for signs of deeper damage like melted parts or burnt smell. If it looks too far gone, it may be time for a replacement. But donât give up too quickly. Many items bounce back with just a simple cleanup.
How to Prevent Battery from Corrosion?
Good habits make all the difference. Here are a few tips to keep your devices corrosion-free:
Remove batteries when not in use. If youâre storing something for months, take them out.
Store devices in a cool, dry place. Avoid hot cars or damp basements.
Use high-quality batteries. Cheap ones often leak sooner.
Check expiration dates. Old batteries are more likely to corrode.
Inspect devices regularly. A quick glance now can save repairs later.
Avoid mixing old and new batteries. This creates imbalance and increases leakage risk.
You can also use a small dab of dielectric grease on contacts. This helps prevent moisture from reaching the metal.
Battery corrosion is a common issue, but itâs not the end of your device. With the right handling and preventive measures, you can extend the life of your electronics and avoid long-term damage. At EBest Circuit (Best Technology), we take battery care and component storage seriously. All components are stored at controlled temperatures to reduce chemical reactions that lead to corrosion.
To add another layer of protection, we pack our products using ESD bags, which not only prevent electrostatic discharge but also act as a barrier against moisture and airborne contaminantsâtwo major triggers of battery and PCB corrosion.
We understand how important reliability is in electronics manufacturing. Thatâs why our quality control process includes moisture-sensitive labeling (MSL), humidity indicator cards, and dry-pack sealing for sensitive parts. If you’re looking for a PCB & PCBA supplier that takes every detail seriously, from component protection to customer satisfaction, EBest Circuit (Best Technology) is here to support your goals with the expertise and care your products deserve.
A black pad in a PCB refers to a defect that occurs during the ENIG (Electroless Nickel Immersion Gold) surface finishing process. In the surface treatment process of ENIG, the radius of nickel atoms is smaller than that of gold atoms, so when gold atoms are arranged and deposited on the nickel layer, the surface grains will show a rough, loose and porous morphology, forming many voids. These gaps allow the bath to continue to react with the nickel atoms, causing them to oxidize. The undissolved nickel ions are trapped beneath the gold layer, forming nickel oxide, the so-called black pad.
When the black pad occurs, this area becomes brittle and doesn’t bond well during soldering. As a result, the connection between the component and the pad becomes unreliable.
Although itâs a well-known issue in the industry, many designers and engineers still face it during production. Itâs not always visible during inspection, which makes it tricky. Once it affects the final board, the reliability dropsâespecially in fine-pitch components or BGA (Ball Grid Array) assemblies.
Black Pad Photos
A black pad appears as:
Dark, muddy, or stained areas on the pad.
Inconsistent finishes between pads.
Rough texture or pits on the nickel layer.
Exposed pads that donât bond during reflow.
You can see the typical photos of black pad as following:
Engineers often spot it only after a failed solder joint. Sometimes, they notice it under a microscope after an assembly defect shows up. When looking at underfilled solder joints or cracks, a black pad might be the hidden culprit.
What Causes Black Pad Defects in ENIG Surface Finishes?
The main reason for the formation of black pads is that the nickel layer is eroded by excessive oxidation during ENIG surface treatment. There are two main steps in this process: a layer of nickel is deposited and a thin layer of gold is applied, as you can see in the ENIG structure diagram below.
Black pads caused by several factors, even when manufacturers strictly control chemical content, temperature, and raw materials, black pads sometimes occur. Here are some factors that Best Team faced during the PCB manufacturing:
1. High phosphorus content
Chemical nickel contains phosphorus. When the phosphorus content is too high, it diffuses into the nickel and causes nickel oxidation. A barrier is formed between gold and nickel during this process. It may cause reliable solder joints to delaminate and crack, resulting in electrical shorts in the PCB.
2. Corrosion during ENIG process
Gold plating is a necessary process for ENIG surface treatment commonly used in PCB manufacturing processes. If it is not operated properly, it will also lead to the formation of black pads. One of the reasons for the formation of black pads during gold deposition is the use of an aggressive gold bath. This nickel bath process causes rapid corrosion of nickel, resulting in black pads.
3. High gold content
High gold content can also lead to the formation of black pads. Excessive gold in the surface treatment of the nickel substrate can cause excessive galvanic corrosion and eventually form black pads.
4. Brittle fracture
Brittle fracture is a type of failure that occurs when a material is under high stress, but does not have the flexibility to withstand stress, and breaks suddenly without warning. This failure usually manifests as a black pad on the PCB surface. In addition, thermal stress, vibration, and shock can also cause brittle fracture. When this happens, it creates a crack structure within the nickel, causing an electrical short circuit.
In short, black pad is not a material defectâit’s a process problem. When ENIG isnât done right, corrosion finds a way in.
How Can You Identify Black Pad on a PCB?
Spotting a black pad on a finished board is tough. It often hides beneath the surface and becomes visible only after soldering problems appear. But there are a few ways to detect it:
1. Visual Inspection
Do not inspect by your naked-eyes. Use a high-powered microscope to examine the pads instead. Look for dark spots, uneven textures, or dull finishes. These are the first signs.
2. X-Ray or Cross-Section
If you suspect the issue but can’t see it, advanced tools help. Cross-sectioning shows the damaged layers. X-ray inspection shows failed joints under BGAs and other tight packages.
3. Solder Joint Analysis
A cracked or non-wetting joint may indicate a black pad. If the solder ball peels off cleanly from the pad, youâre likely dealing with a surface that didnât bond properly.
4. Pull or Shear Testing
This test measures joint strength. A weak joint may lead to a deeper look. If the break happens at the interface of the pad and solder, thatâs a clue.
Although identification is possible, it’s much better to prevent the issue altogether. Because once itâs on the board, the damage is already done.
Why is Black Pad Considered a Serious Reliability Issue in PCBs?
Solder joints are the heart of any PCB. Every connection must be secure to handle temperature, vibration, and time. Black pad disrupts that by creating a brittle layer that doesnât bond well with solder. And if black pads exist, hereâs what defectives will happens:
The solder joint may crack.
Components may detach during vibration.
Connections may fail over time due to thermal cycles.
Weak pads may pass initial tests but fail later.
Even worse, most black pad defects donât show up during inspection or basic testing. This delayed failure causes headaches in the field, leading to product returns, customer complaints, and loss of trust. Thatâs why manufacturers treat black pad as a critical issue. Itâs not just cosmeticâit threatens the performance of the entire product.
How Does Nickel Corrosion Contribute to Black Pad in PCBs?
During the ENIG process, nickel is deposited first, followed by gold. The gold solution is slightly acidic. If the bath is too aggressive or the exposure is too long, it attacks the nickel. This chemical attack causes âspikyâ corrosion. Think of it as tiny pits or cracks in the nickel. These spots are where the solder refuses to bond. Also, when the nickel has too much phosphorous, it becomes glassy and fragile. Under heat, the layer cracks more easily. This leads to more exposed areas and faster failure.
In short, nickel should form a smooth, strong base. But corrosion weakens it and opens the door to the black pad defect. The more pits and cracks it has, the worse the joint becomes.
How to Prevent Black Pads? â For Manufacturers
1â. Improving ENIG processâ: By adjusting the formula of the gold plating solution and optimizing the parameter settings during the electroplating process, the erosion of the nickel layer can be effectively reducedâ.
â2. Strengthening quality inspectionâ: Strengthen quality control on the production line and conduct regular inspections to detect and correct the black pad phenomenon as early as possibleâ.
â3. Controlling the thickness of the gold layerâ: The thickness of the gold layer should not exceed 5 microns, and it is best to control it at around 3.2 to 3.6 microns to reduce excessive corrosion of the nickel layerâ.
â4. Managing the temperature and concentration of the gold plating solutionâ: Control the temperature and concentration of the gold water to avoid excessive temperature and too little gold to reduce excessive corrosion of the nickel layer and incomplete coverage of the gold layerâ.
5. Cleaning surface: After gold plating, high-temperature water flushing, pure water hot washing, ultrasonic or air blowing and other cleaning treatments are carried out to ensure the cleanliness of the welding surface.
How to Prevent Black Pads? â For Designers
1. Selecting alternative materialsâ: For applications that require particularly high reliability, other types of surface treatment materials, such as silver or tin, can be considered, which may provide better performanceâ.
2. Design considerationsâ: Considering how to enhance the stability of the solder joints during the design stage, such as appropriately adjusting the position of the pads or increasing the number of solder joints, can help improve the overall reliability of the circuit boardâ.
FAQs about Black Pads
1. Can black pad be repaired?
Unfortunately, no. Once a pad is affected, it must be scrapped. Rework doesnât help because the damage lies beneath the surface.
2. Does black pad only affect by ENIG finishes?
Yes, itâs specific to ENIG. Other finishes like HASL, OSP, or ENEPIG donât show this defect.
3. Is it common in high-volume production?
It depends on the manufacturer, looking for a reliable PCB manufacturer like EBest Circuit (Best Technology) can reduce the black pad risks. With proper controls, itâs rare.
4. Does black pad affect all components equally?
Not always. Fine-pitch and BGA parts are more sensitive because they have small solder areas. Larger components may be less affected but still at risk.
PCB gold finger is a row of gold-plated conductive contact sheets located on the edge of the printed circuit board, named for its shape like a finger and plated with gold. It is usually used to insert the PCB into a connector or card slot for electrical connection and signal transmission. You’ll often find them on expansion cards, memory modules, and interface boards that plug into the motherboard or backplane.
These fingers act as the physical and electrical contact points between the PCB and its slot. They need to be durable, conductive and corrosion-resistant, which is why gold is used. Unlike standard wires or padding, gold fingers must withstand repeated insertion and removal, so wear resistance and high reliability are top priority in their design.
What Material is Gold Fingers Made of?
Gold fingers aren’t pure gold, and they don’t need to be. Instead, they are a multi-layer structure designed for performance, not cost.
At the core is copper, the base layer used in nearly all PCBs. Copper offers excellent electrical conductivity. But copper oxidizes over time, which affects signal transmission. So, a nickel barrier is added next. Nickel prevents the copper from diffusing into the top gold layer and adds hardness.
Finally, a thin layer of goldâeither hard electroplated gold or soft immersion goldâis applied on top. Gold is chosen for two key reasons: it’s a great conductor and it doesn’t tarnish or corrode. This ensures long-lasting, high-performance edge connectors.
The amount and type of gold used depend on the application. Some fingers will have a thicker, harder gold layer for high-wear use. Others, used less often, may use thinner or softer gold to save on cost.
Types of PCB Gold Fingers
1. Standard PCB Gold Fingers â The most common PCB gold fingers, with horizontal and even arrays. PCB pads have the same length, width and space. This type of gold finger is easy to make.
2. Uneven PCB Gold Fingers â PCB pads have the same width but different lengths and sometimes different spaces like below image showing. For some PCBs, the gold fingers are designed to be shorter than others. The most relevant example of such PCBs is a PCB for a memory card reader, where the device connected to the long finger must first power the device connected to the shorter finger.
3. Segmented PCB Gold Fingers â PCB pads have different lengths, and the gold fingers are segmented. Segmented gold fingers vary in length, and some of them are also disjointed within the same finger of the same PCB. Such PCBs are suitable for waterproof and rugged electronics.
PCB Gold Fingers Manufacture Technical
Not all gold fingers are made using the same process. The method and material used for gold plating affect the performance, durability, and cost of the final product. Letâs take a closer look at the most common types.
Electroless Nickel Immersion Gold (ENIG)
ENIG is a chemical process used to deposit a thin, even layer of gold over a nickel base. Itâs not applied using electricity, so it creates a smooth, flat surface. ENIG is known for its excellent surface planarity and is commonly used for surface mount pads. But in gold fingers, itâs less common unless the board will be inserted only a few times. ENIG produces softer gold, which means the plating wears off faster with repeated use.
Electroplated Hard Gold
This is the most popular choice for gold fingers PCB applications. Electroplating uses an electric current to apply a thicker and harder layer of gold, its gold thickness can be up to 50uââ. Hard gold plating usually includes small amounts of cobalt or nickel, which makes the gold layer more rigid. This helps it resist abrasion during multiple insertions into card-edge connectors.
Electroplated hard gold is a bit more expensive than ENIG but lasts longer and offers better performance for edge connectors.
Edge Beveling
Edge beveling isnât a type of plating but an additional mechanical step. It involves cutting or grinding the PCB edge at an angle, typically 30° or 45°, to make insertion into connectors smoother.
Beveled edges help prevent damage to both the PCB and the mating socket. It also reduces insertion force, minimizing wear and tear. While beveling isnât mandatory, itâs often recommended when the board will be inserted and removed multiple times.
Gold Fingers vs. Edge Connectors
“Gold fingers” and “edge connectors” are both terms used in PCB design, but they refer to slightly different concepts. Gold fingers are part of the PCB, while edge connectors are part of the device that receives the PCB. Gold fingers are the gold-plated pads at the boardâs edge. Theyâre designed to slide into the slot of an edge connector. The connector itself is usually mounted on a motherboard or backplane, holding the PCB in place and ensuring a stable electrical link.
Feature
Gold Fingers
Edge Connectors
Definition
Gold-plated contact pads on the edge of a PCB
Socket or slot that receives the PCB
Location
Part of the PCB itself
Mounted on a motherboard or host board
Function
Transmit signals and power from PCB to system
Provide physical and electrical connection
Material
Copper + nickel + gold plating
Usually plastic body with internal metal contacts
Durability
Depends on gold thickness and use frequency
Built to withstand repeated insertions/removals
Customization
Length, width, plating, beveling can be customized
Usually standard depending on slot type
Common Use
RAM sticks, GPU boards, industrial control boards
Motherboards, expansion slots, backplanes
Design Consideration
Needs precise layout, spacing, and gold plating
Must match PCB layout and dimensions
Benefits of Designing Gold Fingers at the Edge of PCB
Gold fingers allow boards to be plugged directly into other systems without the need for extra connectors, makes design simpler and install faster.
Gold is highly conductive, so the signals and power of devices enable to pass efficiently through the interface. They are often used in high-frequency or high-speed data applications.
Gold does not oxidize or corrode. Even in moist or harsh environments, it maintains its performance over time.
Hard gold plating can handle thousands of insertions without degrading. Thatâs why itâs ideal for modular designs or devices that get frequently unplugged.
Gold fingers reduce the need for bulky connectors, allowing for more compact PCB designsâespecially valuable in smartphones, wearables, and compact industrial modules.
How Thick Is a PCB Gold Finger?
The gold thickness on fingers typically ranges from 3 to 50uââ, depending on how the PCB will be used. For commercial and industrial use, the standard is usually 30uââ of hard gold over 100â150uââ of nickel.
3â10uââ: Suitable for low-cost applications with minimal wear.
15â30uââ: Common for most consumer electronics and industrial devices.
45â50uââ: Used in military or high-end industrial equipment that needs maximum durability.
PCB Gold Finger Plating Process
The hard gold plating process for PCB gold fingers involves several precise and carefully controlled steps. Here’s how it’s done:
1) Apply Blue Protective Mask
All areas of the PCB surface except the gold finger pads are covered with a blue protective mask. This ensures that only the contact pads receive hard gold plating. The conductive areas are aligned consistently with the boardâs orientation to maintain plating accuracy.
2) Remove Oxide Layer from Copper Pads
Next, the oxidation layer on the copper surface of the gold finger pads is removed. We use sulfuric acid for this step, followed by a water rinse. Then, the surface is mechanically scrubbed to ensure it’s fully clean. After that, we rinse the surface again using water and deionized water to eliminate any residues.
3) Electroplate Nickel onto Copper Pads
A nickel layer is then electroplated onto the clean copper surface of the gold finger pads. This layer serves as a barrier and bonding surface for the gold. After plating, the surface is thoroughly rinsed again with water and deionized water to remove any remaining nickel solution.
4) Electroplate Hard Gold over Nickel
Now comes the hard gold plating step. A layer of gold is electroplated onto the nickel-coated pads. This provides durability, conductivity, and wear resistance. Any unused gold solution is recovered for reuse. Finally, the plated area is cleaned againâfirst with water, then with deionized waterâto ensure a spotless surface.
5) Remove Blue Mask
With the hard gold plating complete, the blue protective mask is removed. The PCB is then ready to move forward in the manufacturing process, beginning with the solder mask printing step.
Design for Manufacturability (DFM) of PCB Gold Fingers
1. Beveling Design for Gold Fingers
The safe distance between the gold fingers and the PCB outline edge must be considered. This depends on the final board thickness and the bevel angle. Common bevel angles are 45o.
If the gold fingers are too close to the board edge, copper may be exposed during beveling. To avoid this, copper should be trimmed based on specific parameters as below. However, if you do not want to shorten the gold fingers, increase the safety distance between them and the board edge as per the recommended values.
Bevel Angle
Board Thickness (mm)
Remaining Thickness (mm)
Beveling Depth (mm)
20o
1.6
0.5
1.51
3.0
0.65
1.85
2.5
0.7
2.47
30o
1.0
0.5
0.44
1.2
0.5
0.60
1.6
0.5
0.95
2.0
0.65
1.16
2.5
0.7
1.56
45o
1.0
0.5
0.25
1.2
0.5
0.35
1.6
0.5
0.55
2.0
0.65
0.68
2.5
0.7
0.9
2. Solder Mask Opening Design
To ensure easy insertion into connectors, no solder mask should be applied over the gold finger area. Full openings must be designed here. If the area is not fully opened, solder mask ink between gold fingers can peel off after repeated insertion/removal, which may affect contact reliability.
Gold finger and tin finger areas must have solder mask openings that extend approximately 10 mil beyond the board edge.
The solder mask opening should be 4 mil larger than the trace on each side. Make sure that the distance between the opening and surrounding copper is safe to prevent exposed copper. If copper is exposed, it must be removed (etched).
No solder mask opening is allowed for vias within 2 mm of the gold finger area.
3. Copper Pour Design on the Signal Layer
To support smoother insertion, avoid copper pour (flooding) in the gold finger region on the outer layers. If multiple fingers share the same net and copper is poured, they might be joined into a single pad, which affects mechanical separation and may interfere with insertion/removal.
4. Uneven Gold Fingers
For uneven gold fingers, the main trace should be 40mils, and the auxiliary trace should be 20mils. The connecting point should be 6mils, and the distance between the pad and the 20mil auxiliary trace should be 8mils. After adding the staggered traces, the main trace should be shifted to maintain an 8mil spacing from the long finger pad.
When the main trace enters the board, it should be connected using a diagonal line. If there’s a large groove beside the finger, the trace should be curved, not angled.
How Are PCB Gold Fingers Used?
Gold fingers are found in a wide variety of applications across many industries:
Computers: RAM modules, GPUs, and expansion cards all use gold fingers to connect to the motherboard.
Consumer Electronics: Devices like game consoles, smart TVs, and wearables use gold fingers for modular connections.
Medical Devices: Equipment requiring high reliability often includes gold fingers for secure signal transfer.
Industrial Automation: Boards that plug into PLCs or backplanes use gold fingers to keep connections stable in harsh environments.
Aerospace and Defense: Mission-critical systems rely on hard gold fingers for consistent performance and durability.
FAQs
1. Whatâs the Ideal Thickness for PCB Gold Fingers?
Most designs use 30ÎŒin of hard gold.
2. Are Gold Fingers Always Beveled?
Not always, but beveling helps reduce insertion wear. Itâs recommended if the board is plugged in and out often.
3. How Do I Know If I Need ENIG or Hard Gold?
Use ENIG for light-use connectors or where solderability matters. Go for hard gold when durability and frequent insertions are key.
4. How Much Does PCB Gold Fingers Cost?
PCB gold fingers cost depends on gold thickness, finger length, and quantity. Thicker gold and more fingers increase cost, but also improve lifespan. Contact EBest Circuit (Best Technology) to get a quotation.
5. Can Gold Fingers Be Repaired?
Usually, no. Once worn or damaged, the board often needs to be replaced.
Design for manufacturing, or DFM, is the process of designing products with ease of manufacturing in mind. It focuses on making products that are not only functional but also simple to build. When DFM is done well, it helps reduce production costs, shortens the time to market, and improves quality.
At its core, DFM is about creating designs that match the capabilities of the manufacturing process. Engineers and designers can work together with manufacturers early in the process. So that engineer can identify potential problems before mass production or prototype, save much time for customers.
3 Goals of DFM
1. Cost Reduction
By optimizing the design, you can reduce waste, material usage, and labor. Simple shapes, fewer parts, and efficient processes lead to lower costs.
2. Faster Production
Well-designed parts are easier to manufacture. This leads to shorter cycle times and quicker delivery. Less rework and fewer changes speed things up too.
3. Improved Product Quality
DFM encourages consistency. It minimizes variation and errors during production. As a result, you get a higher-quality end product that performs reliably.
Perform DFM before manufacturing can detect potential defectives that we can’t detect, it covers three aspects, including:
What are the 5 Principles of Design for Manufacturability?
1. Reduce the number of parts/components
By simplifying the design, reducing the number of parts can reduce manufacturing costs and complexity and improve production efficiency. For example, combining multiple parts into one not only reduces the chance of errors, but also saves assembly time and development time.
2. Standardized design
The use of standardized components and design elements helps to reduce production variability and improve product consistency. Standardized design can reduce design time, improve assembly efficiency, and reduce research and development costs.
3. Simplify the assembly process
Considering the convenience of assembly during design can reduce assembly time and cost. Through modular design, the same set of parts can be used alternately, reducing the dependence on specific molds, thereby reducing production costs.
4. Material selection
Select the appropriate material to ensure the manufacturability and performance of the product. Reasonable material selection can not only improve product reliability, but also reduce manufacturing costs.
5. Manufacturing tolerances
Reasonably set manufacturing tolerances to balance manufacturing costs and product quality. Proper tolerance setting can ensure product quality and reduce production costs at the same time.
What is the Difference Between DFM and DFMA?
Itâs easy to mix up DFM and DFMA. Theyâre closely related but serve slightly different purposes.
DFM (Design for Manufacturing) focuses on manufacturing, refers to the design for manufacturing, mainly focuses on how to simplify the parts processing process through design, reduce the difficulty and cost of manufacturing. Its core goal is to optimize designs and make them easier to manufacture while improving product quality. DFMâ focuses on parts processing, reducing manufacturing difficulties through design optimization, such as reducing complex processes and avoiding strict tolerances.
DFMA (Design for Manufacture and Assembly) combines the principles of DFM and DFA (Design for Assembly) to optimize the manufacturing and assembly process of products to reduce costs, increase efficiency and improve product quality. DFMAâ not only focuses on manufacturing, but also on assembly, emphasizing the comprehensive consideration of manufacturing and assembly optimization in the design stage, such as reducing the number of parts, simplifying the assembly process, etc.
In short:
DFM = Can we make this part easily?
DFMA = Can we make and assemble this product easily?
Common Defective Issues Detected by DFM
How to Perform Design for Manufacturing DFM?
Performing DFM is not a one-step process. Itâs a mindset that should be part of every stage of product development.
1. Engage Early with Manufacturers
Bring in manufacturing experts during the design phase. Their insights help prevent rework and delays later.
2. Evaluate the Design for Each Process
Check if the design works well with cutting, forming, molding, or other methods. Each process has its strengths and limits.
3. Reduce Part Counts
Combine parts where possible. Fewer parts mean fewer connections, less inventory, and easier builds.
4. Analyze Tolerances
Use realistic tolerances. Too-tight specs increase cost and difficulty. Focus on where precision is truly needed.
5. Review Materials and Finishes
Pick materials that are easy to source and suitable for the environment. Avoid special coatings unless theyâre vital.
6. Prototype and Test
Use early builds to check for problems. Make improvements based on real data, not just models. DFM is about iteration. Keep refining until the design fits both function and production.
What Should You Consider When Designing for Manufacture?
Avoid complexity design. Keep PCB simple and easy to shape.
Design parts that work well with available tools. Custom fixtures can slow things down.
Think about how the part will be handled. Can it be picked up, rotated, and fixed easily?
Check how tolerances from one part affect the whole system. Misalignment can come from small errors that add up.
Use materials that match the productâs goalsâstrength, weight, heat resistanceâbut also consider cost and ease of use.
Donât ask for polished surfaces unless needed. Extra finishing steps raise cost and time.
Are the parts easy to source? If not, you may face delays or searching for alternative parts.
High-volume parts benefit from different methods than low-volume ones. Tailor your design to the production level.
Get Free DFM Support with EBest Circuit (Best Technology)
At EBest Circuit (Best Technology), we support your design goals from the first sketch to the final board. We offer one-on-one support, PCB fast prototyping, and clear communication every step of the way. After getting your design files, we will perform design for manufacturing analysis, and send the report to you to optimize the design. Our service including:
1. PCB manufacture
FR-4 PCB, High TG FR-4 PCB, Heavy copper PCB, Impedance control PCB, High frequency PCB, Flexible PCB, Rigid-flex PCB, HDI PCB, Aluminum PCB, Copper based PCB, Ceramic based PCB, high speed PCB, IC substrate
2. PCB assembly
SMT, DIP, reflow soldering, Wave soldering, Hand soldering, Mixed assembly, wire harness assembly, PCBA testing, box building assembly
Whether you need help choosing the right PCB & PCBA manufacturer or searching for a cost-effective solution, weâre here. In our next article, we will share acknowledges about design for assembly (DFA), if you are interested about it, please collect our website or leave your message at comments.
