Knowledge Base

PCB Color: How to Select the Solder Mask Colors You Need

Introduction

Hi, welcome to the fascinating world of PCB colors! Have you ever wondered why some PCB boards come in different colors other than traditional green, such as blue or striking red? In this tutorial, we will cover the PCB board's different color particularities and explore the reasons why we used such a different color combination.

An understanding of PCB board colors is helpful for the board manufacturing process, component configuration, and their uses in different projects and devices. We will also give detailed instructions on how any color affects your projects and how to select the best PCB color for your electronic projects. Let's get started.

What is PCB Color

The PCB color generally refers to the oil color on the board that is most intuitively seen when you get a PCB board and is primarily determined by the color of the solder mask or solder resist applied to the surface of the board. The solder mask acts as a protective layer that covers the traces of bare copper wires and safeguards the wires from short circuits and regular wear and tear. It protects the board from moisture, oxidation, dust particles, and other environmental conditions. It also gives a durable and colored finish to the PCB board and helps designers and repair technicians spot the copper wires easily.

solder mask

Printed Circuit Boards, popularly called PCBs, are fundamental components in virtually any electronic device.

They typically serve as a physical foundation for most electronic components (i.e., resistors, capacitors, and integrated circuits). They appear in various colors, such as green, blue, and red. Some manufacturers are now developing them in rare colors like purple and pink.

PCB color choice has a much more significant role than one might initially think. For instance, green PCBs have traditionally been popular due to their reliability and cost-effectiveness. However, different colors can serve practical purposes, too, such as improving heat dissipation or aiding in component identification during assembly and maintenance.

Types of PCB Colors

Printed circuit boards are available in various colors, including green, blue, red, black, white, yellow, purple, and more, with the green solder mask being the standard color of PCB. With the technological innovation in electronics, however, the demand for PCBs in colors other than green is increasing. PCB designers or assemblers now have their preferences and make different color choices for PCBs.

A combination of factors primarily drives this variety in PCB colors. Practical, aesthetic, and functional considerations are some of these factors. This color distinction serves various practical purposes. Different colors of solder masks can give a clear signal of revisions or changes and make users notice. Besides, colors like red and blue will provide contrast or brightness and prevent mistakes that may happen in a mixed PCB assembly.

Some modern PCB types (electronic products) also require specific solder mask colors. For example, white PCB exists because we use it to make lamps and lanterns.

Different Solder Mask Colors

1. Green PCB (Green Solder Mask)

Green-pcb

Since green is the most popular solder mask color used in PCB board manufacturing, many people have always mistakenly thought that PCBs are green or that most of them are green.

Green adds clarity to the printed circuit board, and the green PCB will produce a sharp contrast with the white text, thereby enhancing readability. In addition, the green PCB surface treatment will reflect less light and reduce glare. It helps to read the different parameters and identify components easily. Therefore, the green PCB is essential for printed circuit boards that need a thorough inspection, making it a common color type of circuit board.

You'd find them typically used in various applications, including consumer electronics, industrial machinery, automotive electronics, and medical devices.

2. Blue PCB (Blue Solder Mask)

Enlarged blue PCB board clear picture

Blue PCBs are not as common as green PCBs, but they have gained popularity due to the high screen-printing contrast and the aesthetic appeal and readability of component markings.

The blue PCB color is typically achieved by using a blue solder mask, which is the protective layer covering the copper traces on the PCB. This solder mask color contrasts with silkscreen, making it easy to read the component markings.

Blue PCB colors are also suitable for high-reliability applications, as the blue solder mask is more resistant to moisture and chemicals than other colors. You would find Blue PCBs commonly used in consumer electronics and industrial applications.

3. Red PCB (Red Solder Mask)

Red PCB with excellent visibility

Red PCBs are visually striking and eye-catching. PCB manufacturers often choose them for their aesthetic appeal and good visibility. They can be made with the same reliable materials as green or blue circuit boards. One will typically find them in high-end or specialized electronics, which include gaming motherboards, high-performance graphics cards, and audio equipment.

Their vibrant board color adds a premium feel to these products. Additionally, the red solder mask offers several benefits, including exceptional visibility, well-defined contrast, and an inherent aesthetic allure. On a red circuit board, identifying damages or tracing issues becomes an easy task, making it the best replacement for green solder masks in different projects. However, the contrast of red PCB is lower than that of the green-colored PCB.

4. Black PCB (Black Solder Mask)

Black PCB mixed with cobalt and carbon

Black PCBs are as popular as white PCBs. These two PCB colors produce low contrast and can easily mark significant components, and the black solder mask comes with more elegance and sophistication. Hence, black PCBs are mostly employed by audio devices and mobile phones that have high-end aesthetics.

Thanks to the excellent heat-absorbing property, engineers often use black PCBs in devices with crucial thermal performance, such as high-end graphics cards and high-performance computing systems.

However, the black circuit board is one of the most complicated.

The handling of black boards is complex since the contrast between planes, spaces, and traces is less than that in other colored masks. You must tilt it across a light beam to inspect the board thoroughly, which could be quite challenging.

In addition, it is not good to use black PCBs in various high-temperature applications because black PCB boards may discolor the screen printing. The black color itself absorbs heat during the reflow process.

5. Yellow PCB (Yellow Solder Mask)

yellow flexible pcb

Like many other new PCB colors, yellow PCB can quickly meet design needs like style, cleanliness, and visibility. The yellow solder mask provides obvious contrast between traces, planes, and empty spaces and ensures high efficiency and reparability. It works almost as well as a green-colored mask and should be considered when choosing the right PCB color.

You will typically find them in various electronic devices, from automotive systems to specialized industrial equipment. One thing their unique PCB color does is set products apart in competitive markets.

6. White PCB (White Solder Mask)

White PCB colors provide a clean and modern look, so you'd find them often used in consumer electronics, medical devices, and IoT (Internet of Things) gadgets. They are visually appealing and can enhance the overall design of a product. This makes their choice of color align with minimalistic and clean design aesthetics.

However, it's worth noting that choosing a white circuit board poses some challenges. Unlike other PCB colors that offer contrast, white lacks this distinct advantage. Therefore, white PCBs look particularly good in black screen printing. However, if we use a single headlight, it will be challenging to inspect and repair the white board.

Comparison Chart

PCB Color	Color Code	Visibility	Contrast	Uses
Green	#008C4A	High	Good	It is a commonly used color and has good contrast with white silkscreen. Easily visible.
Red	#FF0000	High	Good	It provides good contrast with white silkscreen and helps to make the PCB board look bold and compelling.
Black	#000000	Low	Low	It is a common part of high-security applications. Best option for EMI protection.
White	#FFFFFF	High	Low	Used for high-visibility applications. Good for EMI shielding.
Blue	#0000FF	Medium	Medium	It contrasts with white silkscreen and is employed to make a sense of calm or peace.
Yellow	#FFFF00	High	Good	It also has good contrast with white silkscreen and can be used to create a sense of optimism.

Why Is PCB Color Usually Green？

If you are familiar with electronic products, you will discover that PCBs generally come in green colors, which is a result of several reasons:

Reason One: Green PCB Is More Conducive to the Detection

Visual inspection is crucial in the circuit board manufacturing process. Although a kind of optical appearance inspection machine called AOI is commonly used now, the final check is done by a well-trained inspector with direct visual observation. If the PCB color is bright yellow or red, it will be dazzling. So, these PCB colors are not suitable for inspection.

In addition, if it is a black or white PCB, debris, broken wires, residual copper, etc., will not be obvious and will tire the workers' eyes. With this in mind, using a green solder mask is a wise choice because neurologists have found that the wavelength of green light has a calming effect on the body and reduces fatigue. A green mask provides greater contrast between the traces, pads, silkscreen printing, and blank spaces on the circuit board.

Reason Two: Green PCB Can Reduce the Production Cost

Since green PCB has a wide range of uses, Green PCB is available in production and procurement areas. In addition, in mass production, similar color paint can be used to minimize the production line cost, so the purchase cost of green paint will be lower than other costs. Besides, because the green PCB production process is the most mature and straightforward, the production efficiency is typically higher than other colors. Therefore, green is the most common solder resist, advantageous in manufacturing cost and delivery time.

Reason Three: Green PCBs Have Better Machine Recognition

Generally speaking, electronic products have to go through board marking and patch welding of components. There are several steps in making the board in the yellow lightroom. When the PCB color is green, the visual effect in the yellow light room is better. But this is not the main thing.

When soldering the patch, it must be checked by brushing the tin on the solder paste, the patch, and the AOI at the back. These processes all require optical positioning and calibration, and the background color of the green PCB has a better recognition effect on the equipment.

Reason Four: Green PCB Is More Environmentally Friendly

Green PCBs are more environmentally friendly due to several factors. Firstly, the production process for green PCBs is the most mature and well-established in the industry. This maturity translates into greater efficiency as well as precision, which can lead to a reduction in waste and resource consumption during manufacturing.

Additionally, the chemical processes involved in creating green solder mask colors have been refined over time to minimize environmental impact, including reducing harmful emissions. On the contrary, blue and black PCB inks are relatively conductive because they are doped with cobalt and carbon and may release toxic gases in a high-temperature environment.

Green-colored PCBs also tend to adhere to stringent environmental regulations. They often use lead-free soldering techniques, mitigating the environmental hazards of lead-based soldering.

How to Choose the Right PCB Color

PCB colors may impact the performance, aesthetics, and cost of the printed circuit board. This is why PCB manufacturers need to factor in some things when opting for PCB color. Below are some:

Contrast and Visibility: It's important to select the solder mask color based on the color of the board substrate and silkscreen marking. It ensures clear visibility. The high contrast helps engineers and technicians easily identify potential faults like misalignment during the soldering process.

Consider Your Application: When deciding on a color, you must consider the applications. Your PCB color should be chosen to match the application. For example, a green PCB color is a good choice for most general-purpose applications, while a red PCB may be a better choice for high-visibility applications.

Aesthetics and Branding: Aesthetics play a great role in product design. This is why you must factor it in when choosing a go-to color. For example, a black PCB color may be a good choice for a product that is designed to be sleek and modern. The application of branded colors for solder masks can help to identify brands and create a unified product design.

Factor in Your Budget: As with anything, you must consider your budget. The cost of different PCB colors can vary. For instance, Green PCBs are typically the most affordable, while other colors, such as red and blue, can be more expensive.

Does Solder Mask Color Make Any Difference on PCB's Functionality

The color of a PCB does not necessarily have a significant impact on its functionality. However, there are some minor differences between different PCB colors.

Lower Reflection Coefficiency

Green PCBs, for instance, exhibit a notably lower reflection coefficient than their blue counterparts. This characteristic significantly reduces glare, proving advantageous in well-illuminated environments, particularly in intricate electronics assembly scenarios.

Visibility and Contrast

Red PCBs excel in terms of visibility, particularly in low-light conditions. Their distinctive color ensures conspicuousness, making them an excellent choice for applications demanding enhanced visibility.

Conversely, the enduring popularity of green PCBs primarily derives from their exceptional contrast with white silkscreen printing, thus optimizing the legibility of markings and component labels during assembly and troubleshooting processes.

Eyes Protection

Blue PCBs, another prevalent choice, share the benefit of high-contrast compatibility with white silkscreen, akin to green PCBs. Furthermore, blue is gentler on the eyes, a crucial consideration for professionals engaged in extensive interactions with PCBs over extended durations.

How to Choose the Right PCB Color Supplier

Choosing a credible and quality supplier is essential for any business, especially businesses relying on PCBs. When choosing a PCB color supplier, there are several factors to consider, including the supplier's reputation, experience, price, and environmental impact.

By taking into account all of these factors carefully, you can increase your chances of selecting a supplier that can provide you with the high-quality PCBs you require. Below are some of the factors to take into consideration:

Reputation and Experience

Look for a supplier with a good reputation and experience providing PCBs in whatever color you desire. You should make sure they provide you with samples and references so you can assess their quality.

Price

The price of PCBs can vary depending on the color, quantity, and other factors. This is why one needs to get quotes from various suppliers so you can get value for your money on your PCB color purchase.

Quality

The quality of the PCBs is important, especially if you intend to use them in critical applications. Make sure the supplier has a good quality control process in place.

Customer service

Customer service is very important when choosing the right PCB color. Your supplier should respond to your inquiries and provide good customer service. Prompt and helpful customer service helps to foster a smooth and collaborative partnership.

PCBasic factory is an excellent choice for a PCB color supplier. We are an intelligent factory specializing in one-stop PCBA production and PCB services. We have a proven track record of providing high-quality PCBs to customers in various industries.

If you are looking for a PCB color supplier that can meet your specific requirements, then PCBasic is a great option. Contact us today to learn more about our services.

FAQs About PCB Color

Q1: What is the Significance of PCB Color in Electronic Design?

A: PCB color plays a key role in electronic design. Aesthetics, component identification, and even heat dissipation are some ways PCB color can play a significant role in electronic design.

Q2: Are There Limitations to Choosing PCB Colors?

A: Although a wide range of colors are available, some may have specific limitations. This is why it is essential to consider your specific design requirements.

Q3: Can I Select Custom Solder Mask Colors for My PCB?

A: Many PCB manufacturers offer a variety of solder mask colors, but custom colors may be available upon request. Check with your manufacturer for options.

Q4: Do Different Solder Mask Colors Affect Soldering or Assembly Processes?

A: Solder mask colors typically don't impact the soldering process, but it's important to follow manufacturer guidelines for best results.

Q5: What Certifications or Standards Should I Look for in a PCB Color Supplier?

A: When assessing potential suppliers, consider whether they adhere to industry-recognized certifications and standards such as ISO 9001 for quality management or ISO 14001 for environmental management. These certifications can indicate a supplier's commitment to quality and sustainability in their operations.

Conclusion

In addition, the color of the substrates, such as black PCB, purple PCB, blue PCB, and light PCB, is too dark, which will increase the difficulty of checking and repairing the motherboard, and the process is not easy to control. Use black PCB as an example;

Black PCB is most likely to cause apparent chromatic aberration due to process and raw material ratio problems in production, resulting in a high PCB defect rate.

The traces of the black PCB are not easy to distinguish, which will increase the difficulty of later maintenance. Many PCB factories do not use black PCBs. Green PCB substrates are available in the military industry and industrial control, products with extremely high-quality requirements. But the PCB color will not affect its performance in the slightest. It is not difficult for us to understand why the PCB color is mainly green.

PCBasic is the Shenzhen PCB Assembly Manufacturer, and we have different PCB colors for you.

Prevthe status quo and opportunities of automotive pcb

Nextthe pcb fabrication process: a step-by-step guide

Share to friends: 6435