Why Do Printed Circuit Boards Come in Different Colors?

Secrets Professional Hardware Engineers Won't Tell You: Why Do Circuit Boards Come in Different Colors?

Printed Circuit boards (PCBs) come in various colors mainly due to the different colors of the solder mask layer covering them. Even though PCB design and manufacturing processes are the same, color does not affect performance or heat dissipation. However, high-end products often use black PCBs, while lower-end products typically use red, blue, green, yellow, and other colors. Manufacturers use colors to give products different meanings and positions.

Are There Differences Between PCBs of Different Colors?

Green PCBs

Green PCBs are the most common, leading many to think all PCBs are green. Green PCBs improve readability because the green background contrasts sharply with white text. Additionally, green PCBs reflect less light, helping to reduce glare, making them friendlier for engineers working long hours. According to IPC (International Electronic Industry Connection Association), about 70% of PCBs worldwide use green solder mask ink. The manufacturing process for green solder mask ink is the most mature, making it cost-effective. Furthermore, green ink does not release toxic gases during high-temperature recycling, making it more environmentally friendly.

White PCBs

White PCBs look clean and neat and are increasingly popular. However, white PCBs can hide the traces, making inspection and maintenance difficult. The contrast between black silkscreen and the white background is particularly good, making identification easier. Market surveys indicate about 10% of PCBs use white solder masks, primarily in LED lighting products.

Yellow PCBs

Yellow PCBs were once common but are now less used. Yellow PCBs have unique advantages in style, cleanliness, and visibility. However, they have poor contrast with the wiring and silkscreen, making inspection difficult.

Blue PCBs

Blue PCBs are considered a high-end choice because they provide significant silkscreen contrast. Although blue PCBs are not as eye-catching as green, black, or white PCBs, they are aesthetically appealing, especially suitable for LCD displays, as they do not create sharp contrast edges or bright background colors. Data shows that about 8% of PCBs use blue solder masks, mainly in computers and high-end audio equipment.

Red PCBs

Red PCBs have good visibility, clearly defining the contrast between traces, planes, and empty areas. The silkscreen on red PCBs looks excellent, which is why many manufacturers prefer using red PCBs. Red PCBs account for about 5% of the market and are typically used in medical devices and professional audio equipment.

Black PCBs

Black PCBs are commonly used in high-end products and are as popular as white PCBs. However, black and white PCBs have low contrast, making it easy to mislabel essential components. Black PCBs tend to focus on specific details, creating shadows, making inspection and repair more challenging. Additionally, black PCBs in high-temperature applications can cause silkscreen discoloration. They are difficult to drill during manufacturing, resulting in lower yield rates and higher costs. Black PCBs, made from a mixture of cobalt and carbon, may affect conductivity. Statistics show black PCBs account for about 7% of the market, mainly used in high-end consumer electronics like smartphones and gaming consoles.

Considerations in PCB Color Selection and Design
Production Cost	Green PCBs have the lowest production cost because the manufacturing process for green solder mask ink is the most mature, and raw material costs are lower. Additionally, since green PCBs are the industry standard, production lines and testing equipment are better suited to handle green PCBs, further reducing production costs.
Visual Fatigue and Engineer Comfort	Engineers working long hours often prefer green PCBs because their low-reflection characteristics reduce eye strain. Green PCBs provide better visual comfort for factory workers needing to perform extensive visual inspections and manual soldering.
Market Positioning	High-end products often use black PCBs because black gives a high-end, professional, and modern feel. This perceived difference makes consumers more likely to associate black PCBs with high quality and performance. For example, Apple products typically use black PCBs to highlight their high-end positioning.
Maintainability	Green and red PCBs are easier to maintain and repair because of their high contrast and clear wiring. In contrast, black PCBs, with their high contrast and shadow effects, make circuit inspection and fault tracing more challenging.

Production Cost

Green PCBs have the lowest production cost because the manufacturing process for green solder mask ink is the most mature, and raw material costs are lower. Additionally, since green PCBs are the industry standard, production lines and testing equipment are better suited to handle green PCBs, further reducing production costs.

Visual Fatigue and Engineer Comfort

Engineers working long hours often prefer green PCBs because their low-reflection characteristics reduce eye strain. Green PCBs provide better visual comfort for factory workers needing to perform extensive visual inspections and manual soldering.

Market Positioning

High-end products often use black PCBs because black gives a high-end, professional, and modern feel. This perceived difference makes consumers more likely to associate black PCBs with high quality and performance. For example, Apple products typically use black PCBs to highlight their high-end positioning.

Maintainability

Green and red PCBs are easier to maintain and repair because of their high contrast and clear wiring. In contrast, black PCBs, with their high contrast and shadow effects, make circuit inspection and fault tracing more challenging.

Environmental and Recycling Considerations

Green solder mask ink does not release toxic gases during high-temperature recycling, providing environmental advantages. With increasingly strict environmental regulations, more manufacturers prefer green PCBs to reduce environmental impact. Moreover, green PCBs have a higher material recycling rate, promoting sustainable resource use.

Future Trends

As technology advances and consumer demands evolve, more color choices and applications for PCBs may emerge. Transparent PCBs have already started to be used in some display devices, offering a futuristic look and unique application scenarios. Transparent PCBs use colorless transparent solder mask layers, giving the circuit board a cleaner, more modern appearance, suitable for high-end consumer electronics and art installations.

In summary, while different colors of PCBs do not have fundamental differences in function and performance, they have various advantages in aesthetics, readability, production cost, environmental impact, and market positioning. When choosing PCB colors, one should weigh specific application needs and cost considerations.

At Huaxing PCBA Factory, we pride ourselves on our commitment to providing PCBA solutions that consistently meet and exceed the highest industry standards. Our strong Quality Management System (QMS) is the cornerstone of our operations, ensuring that every product leaving our facility is of the highest quality.

If you have needs, you can contact us to help you.

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