NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/sci/electron/13063

Internet Message Format | 1992-07-21 | 1.8 KB

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From: [e-mail] (Allen Williams (co-op))
Newsgroups: sci.electronics
Subject: Green Layer on Circuit Boards?
Message-ID: <[e-mail]>
Date: 21 Jul 92 13:46:01 GMT
Organization: Computer Consoles Incorporated
Lines: 29


 I have made some circuit boards using the method posted in this fine
newsgroup a few months ago. This method uses the photoresist coating,
developer, etchant, and tinner. I am glad to say that my boards have
taken a giant leap in quality, up from the old days of drawing circuits
with a etch resist pen and having problems with soldering in components
because the board was so oxidized a week later. I wish I could remember
who it was that posted it (I don't have the document handy) but the
appropriate parties probably know who they are.

 However, one step that I think would be a good addition is the green
layer of plastic insulation that commercial circuit boards have. I've looked
in the Mouser and Digi-Key catalogs, and can't find anything that looks like
the type of insulation that would go on top of the traces.

 Is it possible to add this layer of green insulation on do-it-yourself
boards? Or do you have to cut all these holes for the pads before applying
it, making it uneconomical to use unless you make ten thousand copies using
a cutter press? Or is it applied by using big and expensive machinery?

 Although it's not absolutely necessary to have insulated traces, I feel
that it would be better in the long run to reduce the chances of short
circuits as boards tend to accumulate dust and crud during long term use.


 Any advice, pointers, and help is deeply appreciated.

                                                        Derrick