PCB Color

Whit

Everyone,

Is there any logic or reason for PCB colors? Parallax now has green (BOE), blue (Prop Proto Board) and gray (Propeller Professional Development Board). Is this for easy identification or is there no logic or reason at all?

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Luis Digital

My vote:
- Easy identification

Philldapill

And for uniqueness, I'd guess. Why sell a bunch of products that all look alike?(Marketing is just stupid sometimes...but it works)

Paul Baker

When things go inside an enclosure, no-one cares about the color. But most of Parallax's products have thier board exposed as a product. The stamps are colored specifically to provide identification (frequent tech support question: "What color is your Stamp?"). The other boards are different colors because they can be made different colors,· or to distinguish it from a similiar product:

The·Propeller PDB was made grey to distinguish it from the regular green PDB which makes it handy if you have both to pick up the correct one off your bench without examining it further.

The Prop Protoboard was made blue to distinguish it from the SX protoboards and because it looks good against the gold flash plating process (looked even better on the prototype made in a US fab house where the plating was actually a full gold color, and not the silver with a hint of gold on the production boards, but blue/silver still looks good).

The QuadRover board was made red because it fits with the red/black color scheme of the platform.

Marketing doesn't choose the color, the design engineer and PCB layout engineer working on the product does.

PS. the no longer sold Altera FPGA boards were a 2 color swirled PCB, difficult to find a house that will do that for you.

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Paul Baker


Post Edited (Paul Baker) : 1/16/2009 5:13:34 AM GMT

Phil Pilgrim (PhiPi)

Some of the boards I've designed for Parallax are blue. The historical reason for this dates back to the original TCS230 color sensor board, which uses a TAOS (Texas Advanced Optoelectronic Solutions) sensor chip. The TAOS logo is blue, so their evaluation modules (of which the TCS230 board is one) are all blue. Consequently, when the TCS230-DB (daughterboard version) came along, the board that it plugs into (MoBoStamp-pe) was also made blue, as well as the rest of the daughterboard lineup. The only exceptions are the 7Seg-DB boards, which are black, so they don't show up behind smoked Plexiglas. Even the silkscreen on these is a darker color, and you really have to look closely to read it.

Many manufacturers color code their boards to distinguish prototypes from production boards, or to delineate revision changes. Here is an entire magazine article devoted to soldermask colors.

-Phil

Whit

Thanks guys! I lay awake at night and think of these kinda things!

Thanks for the article link Phil - pretty interesting. I love the theories on why most masks·were green.

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Post Edited (Whit) : 1/16/2009 5:12:06 PM GMT

RobotWorkshop

Hello Whit,

One of the local board houses near me even said they can do custom colors and have mixed them to get close to the desired tint. Someone made boards close to Halloween and the PCB made boards with an orange solder mask.

Most boards have a single silkscreen color. However some can do more. I was shown a board with a red soldermask which had white and blue silkscreens so that it would have a nice logo of an American flag on the final board. Looked really cool. I imagine it cost a bit more but if you had a large run of boards it may not be too bad.

If you are going to get some boards made just talk to the board house you want to use and ask what they can do.

Robert

Tubular

Interesting article, thanks Phil

WBA Consulting

Different companies use the colors for various reasons. When I was at HP in the early 90's, we used red for protos, blue for pre-production, and "plain old green" for production runs. Some engineers nowadays just simply have a preference because it's available. I have seen black used without silkscreen to make it very difficult to reverse engineer a product. White is used on LED lighting assemblies often so that it doesn't affect the reflected light of a white LED. When companies have RoHS and non-RoHS product, it's common to use green for non-RoHS as it's considered "old-school" and one of the other choices for RoHS.

As for the availability, it depends on the fab house. LPI soldermask itself is readily available in many colors and it can be tinted as well. I don't think there's a color that Taiyo doesn't sell or mix. Sunrise PCB (formerly Titan PCB) in the bay area (CA) will do just about any color at no extra charge for typical lot runs.

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Andrew Williams
WBA Consulting
IT / Web / PCB / Audio

Whit

Thanks for the information Andrew!

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

skylight

You'll probably also find that its used as a promotional device like a particular color being "in fashion" especially if visible in the product as part of the overall look..