re why circuit boards are green in article apr mega com au swanee megadata mega oz au geoff swan writes in article apr mala bc ca wagner mala bc ca tom wagner wizzard of old audio visual equipment nanaimo campus writes the color of the board shows the composition of it hence the use of it original and older boards were bakelite composition and were brown phenolic spelling was a tan most non filled fiberglass boards used in computers are green filled fiberglass is blue teflon is white rubbish the reason for the colour of the boards depends on the solder mask that is used older boards bakelite and phenolic rarely used a solder mask these boards are not suited well to automatic stuffing and soldering techniques and hence are the colour of the compound used to make them these days boards are made of fibreglass for most general purpose uses and have a solder mask applied to them to prevent close traces shorting to one another during soldering and also to prevent the decomposition of traces under harsh environments the light and dark green boards ofter seen have a dry film mask applied to them usually applied as a complete film photographically produced the blue and red or orange boards are a two part epoxy or a liquid imageable resist formulation and are applied in a different manner there s a lot of info about the pro s and con s of each but that s another story sla n go fo ill risky b geoff swan research development swanee mega com au megadata pty ltd waterloo rd north ryde nsw australia v fax sorry geoff agree solder mask is green but in the old days we didn t have wave soldering machines which are another topic again i had a crew of a dozen ladies which could stuff and hand solder a board like lightning board under the mask was the original query btw cheap inport electronic devices mainly from rd world countries are done with brown pheonolic boards is seems the electronics industry has discovered the cheap labor pools workers are paid by the board to assemble circuits at home they are very obviously hand soldered quite a few tape recorders are being brought into canada from red china in china there is no warranty for the equipment other than if you plug it in and it works it s yours one of my co workers spent a year there and he said the failure rate out of the box was almost also the original method for making printed with conductive ink on a regular printing press an old lithographer friend had a press for this after the etching method was developed he used the press to print wood grain on doors tom tom wagner audio visual technician malaspina college nanaimo british columbia loc fax callsign ve gda weapon kentucky rifle snail mail to site q c rr nanaimo british columbia canada v r x i do not recyle i keep everything all standard disclaimers apply
