Homebrew PCBs

>From: Chris Graham <Chrisgr@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: Re: [Homebrew_PCBs] How I make my PCBs
>Date: Sun, 18 May 2003 08:15:40 -0700
>
>Hans Wedemeyer wrote:
>
> > I make double side board all the time. I used to do it the way you
> > mentioned, and even wrote a program  for my CNC mill to compensate for
> > alignment problems.
> > I found a better way by printing on transparencies and then aligning
> > them visually, then stapling them together. Then slide the board in
> > between the transparencies and sandwich the whole lot between two plates
> > of glass, and place the sandwich between two lamps
>
>I make boards almost exactly the same way, also using Eagle.  I print with 
>a
>Brother 5040 laser printer at 1200 dpi on overhead transparency slides.
>I've made double sided boards down to 10 mil traces.
>
>I decided to go with Eagle (even though I don't really like its user
>interface because of) its stability,  the extensive parts libraries, and 
>the
>very active support and user forums.  Even if I don't find the exact part I
>want in an Eagle library I can usually find something close that I can 
>start
>with - much easier than starting from scratch on a new part. And if I have 
>a
>question or problem I've always been able to get a quick answer on one of
>the forums.
>
>Regarding printing transparencies, one minor irritation I'd like to 
>overcome
>is that dark areas on the slides aren't as opaque as I'd like, and I've
>needed to double up the top and bottom transparencies, for a stack of four,
>which is a little tricky to align and keep aligned.
>
>What media do other people print slides on?
>
>Also, I read somewhere of someone who printed "transparencies" on normal
>paper and then made them more transparent by spraying them with some
>solution (maybe spray silicone?).  These resulted in very opaque dark 
>areas.
>They needed somewhat longer than normal exposures, but produced excellent
>boards.  I now can't find where I read this, and would love to know the
>details of the process.  Are any of you familiar with this?


ESR (http://www.esr.co.uk) sells a spray to make paper transparent. I 
haven't tried it. I've heard of people using cooking oil, and tried it once; 
it works, but is a bit messy.


Leon
--
Leon Heller, G1HSM Tel: +44 1424 423947
Email:leon_heller@...
My web page: http://www.geocities.com/leon_heller

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