🚀 go-pugleaf

In article <2652@servax0.essex.ac.uk> zotog@essex.ac.uk writes:
>
> I'm new in this news group so forgive me if this has been asked before.
> I recently came to a point where I have to produce a good PCB.
>[...]
> Is it posible to photocopy the piece of paper with the track layout on a
> clear plastic film used on overhead projectors and use this as the film
> plased on the premade positive photoresist PCB and then to expose that 
> in UV light ?

In the December 1989 issue of RADIO-ELECTRONICS, Don Lancaster
outlines a rather neat way of making PCB's.  He calls it a
breakthrough, but I'm not sure I'd go that far, as I'm sure I've heard
of the idea before, perhaps using regular artwork, and an image
reversing photocopier.

Anyway, it goes like this:

     1. Using suitable software (he suggests using PostScript
	directly, for those of us with PostScript printers :-) to
	design your board in 1:1 scale, as a positive, and reversed
	(mirror) image.

     2. Then print the design using a laser printer onto a polyester
	based overhead transparency sheet coated with heated mold
	release agent (Miller Stephenson MS-136). The trick is to use
	a special thermal transfer toner cartridge.

     3. The image may then be transfered directly to a thoroughly
	cleaned PCB blank with even heat, and hardened by baking.  The
	toner will now act as etch resist, and all that remains is to
	etch in the usual manner.

There are a few more hints and tips in the article, including
addresses of suppliers and such.
-- 
						Greg A. Woods

woods@{robohack,gate,tmsoft,ontmoh,utgpu,gpu.utcs.Toronto.EDU,utorgpu.BITNET}
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