Why are computer motherboards green?

Answer 1

Not all are. Many new ones these days are Red and Blue. Green is the most common followed by Amber. This goes for all printed circuit boards really. It's just the natural colour of the board and sometimes they add colouring to it.

Answer 2

There are several theories regarding this, and I'll try not to get too technical. First of all, it's not the board that's green, but the silkscreened coating called the 'solder mask'.

David C told you what a solder mask is, but why green? (and it ain't to hide corrosion)

1.) The green color of solder masks was chosen after extensive testing by the U.S. military at the National Materials and Procurement Center in Cedar Bluffs Virginia in late 1954. According to Colonel Robert Bright, Public Liason Officer, the particular shade of green was found to provide the maximum
contrast to the white silkscreen ink under all tested adverse situations while still allowing a clear view of the underlying circuitry. Every other color tested failed to provide the required contrast under conditions of low / high illumination levels and various colored light sources.

The quantity of Printed Circuit Boards purchased by the Defense Department established a "de facto" standard which most vendors began to follow.

There are a couple of other theories:

(1) When PCB's were hand assembled, a great many of the operators found the green color 'more restful' on the eyes than other colors used.

(2) The green color is from a copper phthalocyanine pigment, which at the time of the first boards, was the only heat-stable organic color.

I think the first answer is probably the correct one, though.

There are a rainbow of solder mask colors today, but there is still some issues with color choice and UV light. I'm not even getting into that!

Cave

Answer 3

Easy answer...because the resin supports are coloured green, and that is because when the copper on the board starts to corrode, it turns green, so they made boards green to help hide the fact the boards were aging, and to show up any area of circuit board not treated.

Technical answer

So you have conductive pathways, or traces, etched from copper sheets laminated onto a non-conductive substrate. Alternative names are printed wiring board (PWB),and etched wiring board.

The pads and lands to which components will be mounted are typically plated, because bare copper oxidizes quickly, and therefore is not readily solderable. Traditionally, any exposed copper was plated with solder. This solder was a tin-lead alloy, however new solder compounds are now used to achieve compliance with the RoHS directive in the EU, which restricts the use of lead. Other platings used are OSP (organic surface protectant), immersion silver, electroless nickel with immersion gold coating (ENIG), and direct gold. Edge connectors, placed along one edge of some boards, are often gold plated.

Areas that should not be soldered to, may be covered with a polymer solder resist (solder mask') coating. The solder resist prevents solder from bridging between conductors and thereby creating short circuits. Solder resist also provides some protection from the environment.

The support is made of resins - normally thermosetting types such as phenol formaldehyde or an epoxy and are used to hold the reinforcements together to form the laminate. Epoxy is the most popular resin type in current use.

Reinforcements can be made from a range of materials, such as paper (low cost), cotton or glass cloth or mat (high strength and low moisture absorption). Woven glass is the dominant material used in industry. Normally of a continuous web or woven fabric form, these reinforcements are used to provide reinforcing for the board. Additives may be used to adjust the board's coefficient of thermal expansion. However, green glass is the cheapest so the colour of the support is normally pale green. Brown glass is used as well.

when combned with the mask, it was easier to make the boards look attractive as a bright green, then any other colour,

Answer 4

It's just the material they are made out of and the colors used. I've seen circuit boards in a variety of colors.

Green has become the most common because it's easy on the eyes and the component designations are still easily read when printed in either white (most common) or black.

Answer 5

Not totally sure but I would think that if they were any other color it may make the solder lines harder to see. I have seen other colors than motherboard green but they are still a shade of green. Cheers

Answer 6

Pure custom, as far as I know.

The natural color of circuit boards is a rather drab pale beige from the epoxy which binds the fiberglass of which the boards are made.

The green color comes from an outer protective film of solder-resist. It is probably colored both so that you can see that it is there and because it makes the boards look better.

Other color are certainly possible.

Source :
http://www.answerbag.com/q_view/88211

regards,
Philip T

Answer 7

Computer boards are not always green, they could be just about any color. It is just the color of the plastic. I could see them not wanting to use red, since red pigments will often have lead in it, a conductor or electricity.

Answer 8

I would think it is a matter the type of plastic used in the laying of circuitry...now the plastic may be coated and insulated, but in my mind platic molds were either coded for color or visability...or just because that is the color it happened to be.

Answer 9

not all mobo's are green it's based on product type and who makes it. green is the primary color for all pre-made systems.(it's more for the guy who has to fix it so he knows what he's dealing with)

Answer 10

jus to show that even these electronic boards came only from nature.

:)