IPC has established a testing standard for solder masks which is used as an industry guideline for material manufactures, OEM’s and PCB manufactures. IPC SM-840D classifies solder mask, Class T and Class H which are summarized below;
T – Telecommunication: includes computers, telecommunication equipment, sophisticated business machines, instruments, and certain non-critical military applications. Solder mask on boards in this class is suitable for high performance commercial and industrial products in which extended performance life is required, but for which interrupted service is not life-threatening.
H – High Reliability/Military: includes that equipment where continued performance is critical, equipment down-time cannot be tolerated and/or the equipment is a life support item. Solder mask on boards of this class is suitable for applications where high levels of assurance are required and uninterrupted service is essential.
For more information about the IPC SM-840D standard please visit www.ipc.org
What Are The PCB Solder Mask Color Options?
Green Solder Mask
Green Solder Mask
The green solder mask is always a popular PCB solder mask option because it allows everything to be seen clearly. Green solder mask has good contrast between the areas under the solder mask with and without copper. You can easily see the traces with your eyes, whereas for black solder mask – you have no idea.
White Solder Mask
White Solder Mask
White printed circuit board solder mask applications are becoming slightly more popular because the white color can make a PCB visual look very pretty in a clean environment. However, the white solder mask hides traces very well. Naked eye inspection can become nearly impossible in some situations, especially if you’re in a room with only direct overhead light.
The ”white solder mask” looks different from different solder mask ink suppliers. Some turns to brighter, some turns to “milk color”. Make sure you and your PCB manufacture have the same understanding of what exactly “white solder mask” you want. Venture engineering team is more than happy to provide you with different “white solder mask” PCB samples for you to compare.
Black Solder Mask
Black solder mask
Black solder masks brings slightly less of a visibility concern compared to white options. In some applications, black PCB solder mask are not recommended because of the increase in heat, which may discolor silkscreen and make the board more difficult to clean.
Red Solder Mask
Red Solder Mask
Red boards are becoming more and more popular options because they provide good visibility and contrast in planes, traces and even your empty space. It’s less contrast than green boards, but still it will give a PCB a feeling of freshness when compared to stale industry standards. Silkscreens stand out well against the red.
Blue Solder Mask
Blue Solder Mask
Label-heavy boards should consider a blue solder mask because of the significant contrast it creates with silkscreen. Traces under blue solder mask can become much more difficult to see without proper lighting and magnification. It is a little more likely to show dirt compared to other colors.
Yellow Solder Mask, Orange Solder Mask , Grey Solder Mask and more
Yellow Solder Mask
Purple Solder Mask
Many new colors are emerging, but they can be difficult to manage. Sometimes, varying production lot will show slight difference. Yellow and orange are pleasing colors, but their contrast is pool in both silkscreens and traces. Grey solder mask are often considered in LED PCBS/ aluminum PCBs projects as well.
Crystal Clear Color Solder Mask
Different colors will balance different requirements, such as cleanliness, visibility and style. You can always try a sample with us before start mass production for new color.
Matte vs. Glossy Solder Mask
Today’s PCB solder mask options also bring new finish designs, which don’t have to do with any coating material. Two of the most common options are matte and gloss solder masks. Before trying any for your next PCB design, you are more than welcomed to contact our sales for free samples – you can use the sample as a reference.
Matte Red Solder Mask VS Glossy Red Solder Mask
Venture’s PCB Solder Mask Options
Printed circuit board solder mask options from Venture are designed to meet your industry needs. We focus largely on the technical nature of your PCB — such as controlled impedance — and allow your team to make the PCB solder mask choice based on what you feel is most suitable for your application.
Venture uses Taiyo as our main solder mask ink provider( include Taiyo Japan, Taiyo USA and Taiyo Suzhou).
The table below shows the common solder mask materials we use for your reference:
|Manufacturer||Series||Model||Color||Finish||IPC SM-840||MFG Location|
Our production engineers have worked with almost every PCB color and finish options available and can ensure your PCB is printed just the way you like. Speak to our sales today to learn more about solder mask colors that might be suitable for your design. Contact Us Today!
Solder Mask Colors: The Ultimate FAQ Guide
During PCB fabrication, you need to choose the recommended solder mask colors.
This guide will take you through all the fundamental aspects of solder mask colors – keep reading to learn more.
- What is a Solder Mask?
- Why are different Colors used for the PCB Solder Mask?
- What are some of the Solder Mask Colors used in PCBs?
- What Guides the Selection of Solder Mask Color in PCBs?
- What are some of the Drawbacks of using Black Solder Mask Color in PCBs?
- What Solder Mask Color is Preferred for PCBs with Heavy Labels?
- Why is Green Commonly used as the Standard Solder Mask Color in PCBs?
- Why are Blue Solder Masks used for LCD Applications?
- What are some of the Disadvantages of using a White Solder Mask Color in PCBs?
- Why is Yellow not a Common Solder Mask Color in PCBs?
- What Causes the differences in Solder Mask Colors in PCBs?
- Can a Solder Mask Color be Produced in Different Variants?
- Does the Type of Solder Mask Color affect the Performance of the PCB?
- How Important is the Viscosity of the different Solder Mask Colors?
- Can Solder Masks Colors be Hazardous?
What is a Solder Mask?
A solder mask is a protective layer that is applied over the conductive copper track on a PCB.
The mask shields the trace from oxide formation and solder encroachment through bridge formation observed with close-packed pads.
Solder mask finds prevalent use in large scale board productions with automated soldering process.
Green solder mask
You find when a solder mask is laid, the component landings are left uncovered by employing a photolithographic procedure.
Solder mask can be silkscreened, sprayed or vacuum laminated followed by a curing process.
Materials used in solder masks include epoxy and dry film and liquid photo imageable ink.
Why are different Colors used for the PCB Solder Mask?
The choice of solder mask color is usually one of personal inclination.
Solder masks can essentially be furnished in one color as green has been until recent times.
Otherwise, here are some of the reasons attributing to the use of different solder mask colors.
- Solder masks are furnished in different colors as a brand identity for manufacturers.
You find some manufacturers provide printed circuit boards with a particular solder mask color to distinguish its product from others.
- Different colors for solder masks are purely provided for aesthetic purposes. You find colors used to impress the users by their impressive hues.
- Some solder mask colors are employed to offer better contrast with the board features such as the copper traces.
You find the surface finishes for the conductive trace to offer better contrast with different solder mask colors.
- Additionally, you can achieve a better board surface appearance by combining different colors for the solder mask and silkscreen.
For instance, using a white solder mask and a silkscreen with black markings has a high resolution.
- Some applications, for effective performance, will work better with a solder mask of a particular color.
You find LCD applications are better placed with a blue solder mask color for its PCBs.
Sharp contrasts and brightness that can affect the quality of images are avoided in this case.
What are some of the Solder Mask Colors used in PCBs?
You will find a variety of color options for your PCB solder mask.
Some of the common solder mask colors used in PCBs are:
Different colors for PCB solder mask
The green solder mask is one of the most common in the PCB industry.
Many PCB manufacturers use green as the default solder mask color.
You find this is typically when the customer has made no color preference.
Printed circuit boards can be furnished in white color which is favored for the clean appearance they lend PCBs.
Additionally, you find a white solder mask appealing when used with a silkscreen with black markings.
While yellow is a relatively new solder mask color used in PCBs, it has gained quite some prominence.
A yellow solder mask color is preferred for its visual aspects such as brightness and form.
Blue solder masks have found massive employment in PCB construction.
You find the contrast ability of a blue solder mask when used with silkscreen to be remarkably significant.
Furthermore, the visual aspect of a blue solder mask is beguiling.
You find the adoption of the red solder mask to be on the rise in the PCB making industry.
The red solder mask is bright enough to be deciphered.
Additionally, you find this solder mask color to contrast well with conductive copper path and board populates.
Black as a primary color offers a simple and visually compelling choice for a PCB solder mask.
Also, using a black solder mask allows large board populates to be highlighted due to its low contrast.
What Guides the Selection of Solder Mask Color in PCBs?
There is a rich color pool to make your choice of solder mask color.
You can test a color choice through sampling before making a final decision.
Your PCB manufacturer can also guide you in an appropriate color choice for your needs.
Some of the aspects influencing solder mask color choice are:
- The nature of the application of the printed circuit board.
For instance, black solder mask color is unfavorable for high-temperature applications.
- The amount of information to be provided by the silkscreen.
Boards with heavy silkscreen markings will require a solder mask color with the best contrast.
- The coating applied over the conductive traces will need to contrast remarkably with the solder mask color.
You can identify the path easily this way.
- Some PCB manufacturers only furnish boards in a single solder mask color. Therefore, requesting a different will be considered a custom quote increasing the board cost.
What are some of the Drawbacks of using Black Solder Mask Color in PCBs?
A black solder mask is limited in the following ways when used on a printed circuit board.
- Black solder mask encompasses carbon derived pigments and cobalt both of which are electrical conductors.
Thus, you find a limited electrical presence when using a black solder mask.
- You also the black solder mask incompatible for use in applications with large thermal dissipations.
As a good absorber of heat, the black solder mask can hamper the clarity of the silkscreen as a result.
- Formation of shadows, especially by large components, causes traces to be blacked out making them indistinguishable.
What Solder Mask Color is Preferred for PCBs with Heavy Labels?
Printed circuit boards with heavy labeling need a solder mask color with a high contrast level.
The contrasting element is useful in helping you to identify the information used on the silkscreen without difficulty.
For modern PCBs, blue solder mask color is deemed to be exemplary for such usage.
Why is Green Commonly used as the Standard Solder Mask Color in PCBs?
The use of a green solder mask has been entrenched in the industry as an unwritten standard.
However, using green as a solder mask color is fueled by the following qualities.
Green solder mask
- A green-colored solder mask contrasts remarkably well with a silkscreen employing white markings.
You find such a combination provides clear motifs that make the board details quick to the eye.
- While green is visible, it is not extravagantly bright.
Consequently, you find limited reflection when employing a green solder mask.
Thus, viewing such a board is not optically discomforting more so when carrying out a manual assessment.
Why are Blue Solder Masks used for LCD Applications?
LCD is short for liquid crystal display. LCD is a common feature of visual electrical devices such as televisions, smartphones, and cameras.
Solder masks of blue hue are employed in LCDs since they form dull edges without the sharpness of contrast.
Furthermore, a blue color provides a background devoid of brightness that would hamper the image quality.
What are some of the Disadvantages of using a White Solder Mask Color in PCBs?
While white is a primary color that offers impeccable use in many applications, its use on PCBs is still limited.
Some of the reasons contributing to its disfavor are highlighted.
- White color reflects light, and when used for the solder mask, it causes reflection that obscures the conductive path.
- You also find carrying out a manual inspection of a PCB with a white solder mask to be a strenuous exercise.
Why is Yellow not a Common Solder Mask Color in PCBs?
Yellow is a striking color that catches the eye.
However, its use on PCBs as a color option for solder masks is limited by its shortcomings in the contrast department.
Picking out the conductive tracks on the PCB surface from the yellow color is a strenuous exercise.
Additionally, yellow is lowly compatible with many silkscreen marking colors making it unfavorable.
You find deciphering silkscreen information on a yellow solder mask background is an arduous process.
What Causes the differences in Solder Mask Colors in PCBs?
You can find solder masks in many different colors as highlighted.
However, the colors may appear in different shades of a similar color background.
Additionally, the green provided by two different manufactures may not be similar.
The differences in color can be attributed to the following:
- Solder masks are derived from chemical mixtures of polymers and dye.
Consequently, the composition ratio of the dye and polymer will affect the overall color.
You find when the ratio of either element is increased or reduced, the shade of the resultant color is affected.
- You find the method of surface finish application to affect the solder mask color.
For instance, the hot air level used in the coating process of conductive traces affects the final solder mask color outcome.
You find the stress effect of this application process to be the cause of the color difference.
- Colors are typically identified traditionally such as black, white, green red, or blue. However, variants of these colors depending on the intensity such as dark green or light blue can be achieved.
Failure to mention the exact color can lead to a different color variant than desired.
- The difference in color can be attributed to the different processes used by manufacturers.
While the raw elements can be similar, the manufacturing approaches of the solder mask can differ.
Subsequently, you find different color results.
- The color differences can also be attributed to the external copper features.
An excess of copper will result in a different solder mask color shade compared to one with less copper showing.
Can a Solder Mask Color be Produced in Different Variants?
Yes, it can.
Solder masks colors are derived from dyes used with resin-based polymers.
You can thus achieve different shades of a single color by altering the dye and resin ratio.
To achieve a more pronounced color, you can increase the dye amount or reduce the resin amount.
Conversely, a lighter shade can be achieved by decreasing the dye amount or increasing the resin amount.
While green is a common PCB solder mask color, there are many variants of green available.
You will find dark and light green color options, matte green, and even sun green to mention a few.
The color intensity affects the contrasting ability of the solder mask with other board features such as the conductive path.
Does the Type of Solder Mask Color affect the Performance of the PCB?
The performance of the Printed circuit board is not significantly affected by the choice of solder mask color.
You find the solder mask color can affect only non-performance related aspects such as the inspection process.
For instance, carrying out a manual optical inspection on a board with little contrast can be a strenuous activity.
In such cases, you find that identifying the conductive traces is difficult.
However, some solder mask colors such as black and blue employ the use of carbon and cobalt elements in their makeup.
You find these elements are responsible for some electrical charge movement within the solder mask layer.
Electrical flow in the conductive traces can be affected by this movement that could result in shorted circuit paths.
How Important is the Viscosity of the different Solder Mask Colors?
Viscosity is a fluid property that demonstrates the tendency of a fluid to resist movement.
You find the inks used for the different solder mask colors have different viscosities.
The green color pigment has the least viscosity while black exhibits the greatest resistance to flow.
The other color options have viscosities ranging in between.
Viscosity is useful especially in PCBs with a large component density.
Here, you find reduced space between component landing pads.
The difficulty in applying a solder mask on such board increases with increasing viscosity.
Consequently, you will find the application of a green solder mask to be easier in such a case.
Can Solder Masks Colors be Hazardous?
You can find solder mask colors to be toxic particularly when they are subjected to high heat or burning.
The toxicity of the solder mask color can be attributed to the pigments used in the solder mask preparation.
Some solder mask inks contain elements that emit poisonous gases when they burn or decompose.
You find black and blue solder masks contain elements that can release poisonous gases on heat-induced decomposition.
As a result, they are unsuitable for thermal intensive applications.
Solder masks that are green in color employ no harmful substances in their makeup.
Subsequently, they pose no threat to the environment through harmful emissions.
Contact us today for all your PCB solder mask technologies.