What makes a purple PCB worth considering? Most circuit boards today are standard colors, making them less unique. On the other hand, purple is rare and distinct from the others. We wrote this guide to help you understand this PCB type and why you might want to choose it.
What is a Purple PCB?
A purple PCB is a printed circuit board with a purple-colored solder mask layer. The solder mask determines PCB colors. The layer primarily prevents solder bridges. It also protects the board from oxidation and corrosion damage.
A green PCB is the industry standard; many boards use this color. Other standard colors include red, blue, yellow, black, and white. Your manufacturer may use these for your PCB, with green being the most dominant.
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How are Purple PCBs Produced?
The board undergoes the standard manufacturing process. The steps include laminating a dielectric base with copper foil, drilling the laminate, etching the foil, and applying coatings. It only differs in solder mask application, requiring purple pigments.
Pigment Addition
The fabricator adds the pigment to the solder mask layer. We mainly use it when the color has no strict requirements. In other words, the solder mask can be less vivid. It also suits situations where the thickness is not a restrictive feature.
Base Mask Color
This method involves coating the circuit board with the base solder mask (different color) before applying the pigment. It creates a thicker coating than mixing the solder mask with a pigment.
It also produces perfect purple PCB boards, improving their look and appeal. Another benefit is that it allows you to select where to apply the color for selective masking.
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Types of Purple PCB
Depending on the number of interconnects, your purple circuit board can be a single-layer type or multilayered. The board can also be a rigid or flexible substrate, as the section below explains.
Single Layer PCBs
Single-layer boards are one-piece laminations made of an insulating material coated with a conductive layer. They have the copper layer on one or both sides. Single-sided types are the most basic, while double-sided variants pack more parts.
Multilayer PCBs
Purple-colored PCBs can also be more than two layers, with conductive and insulating sections. This board type has more interconnects, with vias or plated through holes to link them electrically.
Rigid PCBs
Rigid boards cannot bend. Instead, they remain robust throughout production and later during use. Most applications require this bard type owing to its mechanical strength. Sometimes, though, it has flexible sections for applications requiring localized bendability.
Flex PCBs
These are bendable, allowing you to fit them into confined spaces. They also take various shapes, following contours or satisfying the bending needs of foldable devices. Additionally, they resist vibrations, suiting harsh applications like automotive systems.
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Why Choose a Purple PCB?
A purple circuit board can help you achieve various benefits. Sometimes, the manufacturer uses the color to distinguish some boards from others. The following reasons make a good choice for your project or application.
Parts Visibility
A purple solder mask enhances circuit visibility, allowing a clear view of the traces and assembled electronic components. The improved clarity makes quality control inspections easier. That includes automated testing, AOI, which uses cameras to check boards.
Aesthetic Appeal
The hue is visually pleasing and can make your circuit boards look uniquely attractive. It evokes a luxurious feeling, giving your board a look that distinguishes it from others. The color also gives your boards a premium look that quickly attracts attention.
Brand Recognition
The color is rare compared to popular green, red, and black types. This uniqueness can help you brand your business, ensuring it remains exceptional in crowded markets. Your customers will instantly recognize your product, unlike when using standard colors.
Purple PCB Limitations
Purple circuit boards present specific constraints that should be evaluated for project suitability. Key limitations involve higher fabrication complexity and longer production lead times compared to standard PCB colors.
Longer Lead Time
Your manufacturer has a range of standard colors they stick to. Ordering the custom option may, therefore, require them to stop producing them and create yours. That would take time, as the machines would require setting up and the pigment ordering.
Higher Cost
A less common PCB color is bound to cost more. That’s because it requires new pigments and formulations. It may also mean having to clean application equipment and rid it of earlier solutions.
All these activities increase the cost of producing the boards. Additionally, the manufacturer may set minimum order quantities for such colors. The MOQ serves to offset the increased production costs.
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Applications of Purple PCB
Like any other color, these boards find uses in all electronics industry sectors. You choose them for these applications, regardless of whether you want them to be simple or complex.
General Electronics
You can use them in consumer electronics like TVs, audio equipment, wearable tech, communication gadgets, and household appliances. Other electronic devices that can use the PCB include gaming systems and toys.
Specialized Electronics
Specialized electronics include automotive systems, telecommunication equipment, and industrial automation. Others are aerospace, medical, and military devices or systems. These are applications with strict requirements, such as heat tolerance and EMI shielding.
Prototyping and Testing
Manufacturers use them to color-code prototype circuit boards, separating them from the others. It helps workers avoid mix-ups, especially when most boards are green. It also saves time by making the board easy to recognize.
DIY Projects
You can also use them if you’re a hobbyist creating your own products. As discussed earlier, the color will improve the visual appeal compared to options like black or orange. It won’t affect the boards’ performance or lifespan but will make them stand out.
Purple PCB Manufacturer Selection
How do you choose a company to fabricate your purple board? Being a less common color, you want to be sure they can produce it first. Other factors worth considering include the following.
Experience: Select a supplier with extensive experience in this circuit board type. They understand how to control the color without affecting solder mask quality.
Product Standards: Ensure the fabricator follows IPC standards for solder mask thickness. You want it within limits to ensure quality and reliability, among other needs.
Application Technologies: review their solder mask application technologies. Consider modern techniques like inkjet or spray printing, especially if your board is a high-density type.
Conclusion
A purple PCB is a unique board that allows you to customize your project. Although rarer than green PCBs, it offers various benefits, such as unique coloration that can help brand your product. The color is also cool and visually pleasing. Should you choose it, ensure the manufacturer you select offers the service, among other considerations.
