At PCB Trace Technologies Inc., we manufacture various types of PCBs or Printed Circuit Boards with different colors, as required by our clients. Although it is common belief that color choice may not matter much for PCBs, that would not be the right assumption. The industry uses color for PCBs as a form of security, traceability, and identification. In fact, color is one of the most critical design choices for any PCB. With advancements in innovation and technology, our customers can choose from a huge range of colors to customize or distinguish their diverse circuit boards. In this article, we will examine the various options most manufacturers offer their customers.
Importance of PCB Colors
Typically, manufacturers cover the entire PCB surface with a solder mask, and the PCB derives its color from this layer. Although a huge range of solder mask colors is available to PCB users to choose from, the most common ones are green, red, blue, white, black, purple, and yellow. Again, of these, users prefer the green the most. However, as the use of PCBs increases, so does the demand for PCBs in colors other than green as well. Now, PCB designers can choose the PCB color most suitable for their application.
The choice of the color of a PCB has considerably more significance than it initially appears. Although green is cost-effective and reliable, other colors can be individually useful, such as in thermal management and in component identification during assembly and maintenance. A combination of factors leads to the final choice of the PCB color, with aesthetics, practicality, and functional characteristics leading the considerations. While a brightly colored PCB looks attractive, changing the color can be a signal of changes or revisions in the board. Blue and red colors are bright enough to prevent mistakes during a mixed PCB assembly. Some products require PCBs with a specific soldermask color. For instance, electronic lamps and lanterns require white PCBs to reflect light.
We list some reasons showing the importance of PCB colors:
Manufacturing — During PCB fabrication, manufacturers may mark various layers in specific colors to indicate their special characteristics, thereby allowing easier assembly and testing.
Differentiation — In a complex electronic system with multiple boards, colors can help to differentiate between PCBs. Technicians can quickly identify and troubleshoot boards with specific colors.
Aesthetics — In the consumer electronics industry, the color of a PCB can be an important part of the overall design, adding to the visual appeal of the product. Manufacturers often align the PCB colors with product branding and user preference.
Environmental Considerations — Some industries demand specific colors on their PCBs to comply with environmental standards or safety regulations. For instance, many industries mandate using green PCBs as an indication of their lead-free nature.
Common PCB Colors
With green being the most popular color for soldermask in the PCB industry, many users mistakenly assume that green is the only color available for PCBs.
The popularity of the green color comes from the clarity it brings to the circuit board. The green base color produces a sharp contrast to the white text, enhancing its readability. Moreover, the green surface reduces glare as it reflects less light. This helps operators identify components readily, enabling them to read the printed text on the board. Therefore, for PCBs requiring a thorough inspection, green is an essential color, making it the most popular color type for circuit boards.
Various applications use the green soldermask in PCBs, including industrial machinery, consumer electronics, medical devices, and automotive electronics.
Although not as common as the color green, the blue color has become popular lately because of its high screen-printing contrast, higher readability, and aesthetic appeal.
The blue color of the PCB typically comes from using a blue solder mask, it is a protective layer that protects the copper traces on the board. The white silkscreen color contrasts with the blue soldermask color, making it easier to read text and component markings.
As blue soldermask is more chemical and moisture-resistant, many applications specify it over other colors. For instance, many industrial and consumer electronic applications commonly use blue soldermask on their PCBs.
PCBs with the red soldermask color are visually striking and eye-catching. Their good visibility and aesthetic appeal make users choose red over other colors. Manufacturers can offer high-quality and reliable PCB materials with red soldermask in place of green or blue. Most specialized or high-end electronic applications use red PCBs. This includes high-end audio equipment, high-performance graphics cards, and expensive gaming motherboards.
The vibrant red color adds a premium touch to the boards. In addition, the use of red soldermask offers many advantages like high contrast, well-defined texts, exceptional visibility, and an exceptional aesthetic allure.
The red surface makes it easier to identify damages and trace components for identification and repair. Although red is an almost perfect replacement for green soldermask in many projects, it presents a lower contrast as compared to green PCBs.
Black and white soldermasks are also very popular. However, compared to other colors, both black and white produce lower contrast levels, and this makes reading component markings more difficult. However, black soldermask offers a level of sophistication and elegance not seen in other colors. Therefore, high-end applications like mobile phones and high-end audio devices are applications that mostly use black soldermask.
As black soldermask has very high heat-absorbing properties, devices requiring crucial thermal performance often use black PCBs. High-performance computing systems and high-end graphics cards are examples of applications that often use black soldermask.
However, using black soldermask in high-temperature applications can prove detrimental. The black color absorbs heat and may discolor the screen printing. This can also happen during the reflow process of assembly.
Moreover, a black circuit board is very difficult to handle. This is because of the low contrast the black color produces between traces, spaces, and planes. In fact, the contrast is far lower than that produced by other colors. To inspect a black board thoroughly, you will need to tilt it to produce the proper contrast from light reflections—this can be quite challenging.
For a modern and clean look, it is hard to beat a white PCB. That is the main reason medical devices, consumer electronics, and IoT gadgets use PCBs with white soldermask. The visual appeal of a whiteboard can enhance the design of the product. Therefore, the choice of white color aligns suitably with design aesthetics, producing a clean and minimalistic look.
However, using the white soldermask on a circuit board poses its own challenges. The main reason is the very low-level contrast of the white color, as compared to any other. Although using black color text on the white surface does improve the contrast considerably, the glare from the inspection lamp on the white surface makes inspection and repair a huge challenge.
PCBs with yellow solder masks are unique and offer an eye-catching alternative to the other, more traditional colors. The vibrant appearance of a yellow board can make electronic devices look visually distinct. Yellow solder mask, like other colors, provides excellent electrical corrosion resistance and insulation. This ensures better reliability and longevity of the circuit board.
Custom and Specialized PCB Colors
Multilayered PCBs and Color Variations
For projects requiring advanced functionalities and complex circuitry, an excellent solution is multilayered PCBs with variations in color layers. Consisting of multiple layers stacked one on top of another, each layer has its own solder mask with a distinctly different color.
The variations in layer color help in visually distinguishing the different functional circuit sections, simplifying the testing and debugging processes.
Fluorescent and UV-Reactive Colors
PCBs with fluorescent and UV-reactive colors offer a unique experience of electronic design, both captivating and attention-grabbing. The soldermask on these PCBs is special as it fluoresces under ultraviolet light, providing a visually impressive effect.
Typically, in use where aesthetics and visual appeal are crucial, fluorescent and UV-reactive PCBs are common in devices using gaming peripherals, artistic installations, and custom lighting systems.
A modern and cutting-edge technology, PCBs with a transparent substrate and soldermask offer designers a choice to be unique and creative. These PCBs are typically made of translucent materials like glass or acrylic. Using transparent PCBs offers a view into the internal PCB structure while providing the necessary functionality.Ideal for creating visually striking installations or showcasing intricate internal designs, transparent PCBs are ideal for applications that emphasize the display of interplay between circuitry and light.
How to Choose PCB Color
Choosing the most suitable color for your PCB typically involves more than just personal preference. You must carefully consider various design and technical factors to ensure optimal visual appeal, functionality, and performance.
Branding and Design Considerations
Brand Identity and Product Aesthetics
For instance, products that are more playful and vibrant can use brightly colored PCBs, while modern designs of sleek products may benefit from metallic or black colors.
The designer must ensure alignment with overall brand identity and product aesthetics. They must consider the market segment they are targeting, along with the intended use of the device.
Market Preferences and Target Audience
For a successful product, it is essential to understand the market preference and the target audience. There may be varying preferences for colors in different market segments. It is worth conducting market research while analyzing industry trends to obtain insight into the color preferences in your target market.
Such a study can help to adapt the PCB color to meet the expectations and tastes of your audience. While this can enhance the market competitiveness of your product, you can also use the study to enhance its visual appeal.
Competitive and Differentiation Advantage
Picking a distinctive and unique PCB color can make your device stand out from competitors’ products while creating a memorable experience for potential customers. Such differentiation is essential for products facing a competitive landscape.
Consider the color choices already under use in your industry, and explore options for deviating from the norm but simultaneously maintaining visual harmony. Such a strategic choice can offer the necessary competitive edge to your product while reinforcing its market position and branding.
Carefully consider all design and technical factors outlined above, and this can help you make an informed decision when choosing the PCB color for your board. You must prioritize functionality, performance, and market appeal in the correct sequence to help you create a product that performs optimally while also capturing the interest and attention of your target audience.
Signal Integrity and Electromagnetic Interference
The choice of PCB color may affect signal integrity and EMI or electromagnetic interference issues.
Dark colors, such as blue or black, are better at providing EMI shielding, and this reduces the risk of interference and, hence, signal degradation. On the other hand, light colors on a PCB are more prone to EMI because of their lower reflection and absorption properties.
Therefore, assess the EMC or electromagnetic compatibility requirement of your device for selecting a soldermask color for your PCB in alignment with those needs.
Thermal Management and Heat Dissipation
Thermal management and heat dissipation are critical considerations in most electronic devices, especially for those with high-power components.
PCBs with darker colors, especially black, can absorb heat better, thereby aiding thermal management. On the other hand, PCBs with lighter colors are more heat-reflective, and this can lead to thermal issues.
It is necessary to understand the thermal management requirements of your products and devices, along with their operating conditions. This can help you choose a more suitable PCB color that ensures better heat dissipation.
Visibility and Contrast of Component Markings
Reference designators and silkscreen labels are component markings that play a crucial role in the assembly, testing, and maintenance of PCBs. The contrast between the component markings and the PCB color affects their visibility significantly.
Select a PCB color that not only offers good contrast but also enhances legibility while simplifying identification. This increases the efficiency of the assembly and troubleshooting processes.
At PCB Trace Technologies Inc., we feel that PCB color is not just a cosmetic choice, as it can significantly affect the functionality and aesthetics of electronic devices. A careful choice of the PCB color can not only enhance the visual appeal but also aid in troubleshooting while keeping the product aligned with the brand image.