PC Board Color- Choosing Your Desired Color

PC Board come up in different colors of which a green solder mask is the most common one. You will see most circuit boards with green solder masks. But, the industry is getting innovative due to changing technologies, so designers try new colors to make printed circuit boards.

PCB Solder Mask

Before getting into PCB colors, you should know what the solder mask is? The printed circuit board has different layers, and the top layer is the solder mask, whereas the bottom layer is the copper foil. The purpose of the solder mask is to cover the bottom layer from getting polluted or oxidized. The main material of solder masks is often the insulating resin which is printed on the circuit board’s unsoldered areas. The resin protects the board from heat, moisture, and any kind of damage.

Printed Circuit board Fabrication

You can customize a circuit board in terms of solder masks and other elements. According to research, 99% of solder masks are green. However, other colors are also emerging, such as red, black, white, yellow, blue, and purple. These colors are used for different applications. Such as RDs at the NPI stage are often made red. Whereas white is used for LED light circuit boards.
Each PCB color has some good and bad aspects that we will discuss here.We will also help you choose the right PCB color according to your application. Let’s start with the colorgreen.

Green Solder Mask In PCB

Though many colors are there, the green solder mask is still at the top as it helps to visually inspect the PCB to find any defects. Moreover, green makes a good contrast with the white silkscreen, helping you to remove the flux residue. If you don’t know how to select a color for the solder mask, go for green right away.

Red Solder Mask In PCB

Red is another color for PCB solder masks,and it adds brightness to the PCB. Red has a nice contrast with planes, areas without copper, and traces. However, the contrast is less than a green circuit board.
You may need a magnifier to find any defects in the traces. However, the red solder mask is compatible with screen printing and also helps remove residual flex like a green solder mask.Red also enhances a device if the circuit board is visible.

Blue Solder Mask In PCB

PCB with a dark blue solder mask is also popular. It hasless contrast with the planes, traces, and no-copper surfaces.Hence,you have to use a magnifying glass to inspect the construction defects. But, it has a high contrast with screen printing that makes blue suitable for a PCB with several components.
But, blue is less clear than green and red, and it highlights the dirt that makes it hard to remove the flux residue. A bluesolder mask is ideal for boards with hidden routes. It is also compatible with Arduino open-source tasks or products.

Black Solder Mask In PCB

A black solder mask is not so ideal in terms of inspection, as planes, traces, and no-copper surfaces have less contrast. Other than a strong magnifier, you also have to rotate the light to create a shadow to highlight the trace.
However, there is a good contrast of screen printing, and it’s visible on the board without any lights and so are the pads.But,the black solder mask has a high heat absorption during reflow. You have to place a temperature checker near the board while manufacturing. Moreover, the screen printing gets light brown during reflow due to the board’s high heat absorption.
The dirt also gets more prominent on the black surface, making it hard to clean. That’s why the manufacturing of a black PCB board involves more cost than other colors. On the other hand, black is ideal for LCD panels.
The black solder mask has two types, including matte and gloss of which matte black contrast is better than the glassy black.However, a black solder mask gets soiled and it becomes hard to repair it.

White Solder Mask in PCB

White solder masks have the lowest contrast than other colors, and placement of the marks becomeshard evenif they are under lighting. Whereas the cleaning of a white Printed Circuit Board is so difficult that you can’t imagine. You have to do so much effort to remove the stains from a white PCB.
However, it has some benefits as black printing on a white PCB creates a good contrast. You can use a white solder mask in LED applications where the front panel has to be white to increase the brightness.

Yellow Solder Mask in PCB

Yellow PCB is as good as green because there is a high contrast between theplanes, traces, and no-copper surfaces. You can use the dark yellow mask to enhance the routes, making them prominent.
There is one disadvantage of using a yellow solder maskand that is it’s less contrast with the white silkscreen. Many manufacturers prefer a black silkscreen with a yellow solder mask, even though it is less satisfactory.
It is easy to clean the residue from a yellow solder mask.So, yellow can be a great choice even though some people don’t like a lively color like this.

Purple Solder Mask in PCB

Purple PCBs are rare, however, advanced devices can have such boards. Purple has good contrast with the traces and planes. However, it does not go well with white silk printing. But, a purple solder mask would look great with an immersion gold surface, creating a good match.
So, you can choose any of the above colors to customize your PCB, depending on your requirements.
Why Should You Use Different PCB Colors?
It is not enough to know that PCB has different colors, because one should also know its reason. There are a few reasons behind using different PCB colors instead of just green, such as:

• Different PCB colors help engineers indicate the revisions and changes to help users recognize them.
• The application of other colors in PCBs can create better contrast. You have to understand the importance of the assembly tools in terms of transmission light, reflectance, and absorption.
• Different PCB colors can reduce the errors caused by a mixed assembly. Moreover, the contrasting colors help decrease lead-free meetings.
• The colors of the printed circuit boards are known as PCB codes. You would see modern PCBs in different colors compared to traditional boards. Even today, the PCmotherboard’s color is green epoxy because of its qualities
• Though the colors of the PCB solder mask don’t influence a board’s performance, they can enhance its resolution. However, solder masks with clear transparency have a high resolution. The yellow and black PCB resolution is less than other colors like green, red, and purple.

Hope the above discussion helped you understand different PCB colors along with their advantages and disadvantages.

FAQs

What Is PCB Solder Mask?
The printed circuit board has different layers, and the top layer is the solder mask, whereas the bottom layer is the copper foil.
How Many PCB Colors Are There?
PCB comes up in several colors, such as green, red, black, white, yellow, blue, and purple.
What Is the Green Solder Mask?
The green solder mask makes a good contrast with the white silkscreen, helping you to remove the flux residue.
Is Red Solder Mask In PCB Effective?
Yes,the red solder mask has a nice contrast with planes, areas without copper, and traces.
What Is The Reason Behind Different PCB Colors?
Different PCB colors help engineers indicate the revisions and changes to help users recognize them. They reduce the errors caused by a mixed assembly. Moreover, the contrasting colors help decrease lead-free meetings.
Why Engineers Don’t Prefer Black Solder Mask?
A black solder mask is not so ideal in terms of inspection, as planes, traces, and no-copper surfaces have less contrast. Moreover, it gets dirty and is hard to clean.
Where Can I Use A Purple PCB?
The purple solder mask is compatible with an immersion gold surface, as both match very well.

Wrap Up

The green solder mask is the most common in circuit boards due to its high contrasting ability. The purpose of the solder mask is to cover the bottom layer from getting polluted or oxidized. The main material of solder masks is often the insulating resin which protects the board from heat, moisture, and any kind of damage.
Many users customize a circuit board in terms of solder masks and other elements. You will see various PCB colors in different applications, such as RDs, LEDs, PCs, etc.
Would like to know more about PCB Colors or smt assembly? Email us at sales@pnconline.com

Written by Sam Sangani

Sam Sangani is the President & CEO of PNC Inc., a Nutley, NJ based Printed Circuit Board manufacturer. Sam graduated from L. D. Engineering College with a BS Degree in Mechanical Engineering. He also continued his education and graduated from Steven’s Institute of Technology where he acquired a Master’s degree in Computer Science.

After completion of his BS, Sam worked as a QC Manager, for Xerox, Romania and London. He was responsible for the Quality Control of Cable and Wire Harness imports from Romania. After completing his Master’s Degree, he worked as a Senior Programmer with IBM, Tucson, Arizona. Sam was responsible for leading the Mainframe System Programming Team.

In 1997, Sam acquired PNC INC., a Nutley, NJ based PC Board fabrication Shop. From 1997-2013, Sam has made tremendous improvements and changes within PNC INC., as he added many new Products and Technologies in PNC’s portfolio. With his proven track record and leadership, PNC has never had an unprofitable year and has continued its growth yearly since 1997.

His current responsibilities are Strategic Planning, Corporate Management, New Business Ventures, Sales & Marketing, Trade Shows, Professional Services and leading productive teams to achieve peak potential. He has also utilized Lean Management techniques which have built a foundation for PNC’s high-paced growth. Sam also enjoys real-estate investing, web design & SEO, trading stocks, options, futures and Forex markets.