Homebrew PCBs

The fact that you are unlikely to get consensus on any of your question 
should be an indication that there is a fairly wide tolerance involved 
here. Here is my 2c:

1. Cleaning - The rule I learnt 30 years ago when I first did this is 
that you want a 'wettable' surface, i.e. when you hold the board under a 
tap, the water should evenly cover it, and not bead up. How you get to 
that point is up to you, but generally scouring powder, fine wet & dry 
sandpaper (400grit or higher) or 3M pads will all get the job done. 
Wiping down with some degreasing solvent (alcohol, acetone etc) is 
entirely optional.
2. Toner transfer is definitely the easier method *if* you have hot 
roller laminator and *if* it gets hot enough. You'll generally know when 
you have done enough passes because the paper will stick. Find a paper 
that works for you, you can get by without the specialty toner transfer 
paper. I use heavyweight brochure paper simply because I have some, but 
most glossy magazine paper will work as well.
3. If you want better resolution, go photoresist, but bear in mind, 
there a far more variables, e.g density of your transparencies, exposure 
time, developer strength etc., and if you buy presensitized pcb, your 
mistakes can be costly (though you can use your failures for toner transfer)



synchronousmosfet@... wrote:
>
> Guys, thanks very much, I appreciate the feedback.
>
> I can definitely see some mistakes I've been making with the transfer 
> method...it really surprised me to find out from several of you that 8 
> passes are sometimes needed, it honestly didn't occur to me that 
> additional passes would make any difference.
>
> I have to make a fundamental decision...whether to try yet again to 
> make the toner transfer method work....I mean, I DO have all the 
> stuff, the special paper, the green film, the laminator, etc., etc., 
> ...and just get CRAZY about cleaning boards, using solvent, doing a 
> zillion passes, etc., and WORKING on the process until I finally get 
> it to work RIGHT....
>
> ....or to go straight to the photoresist method. I realized in writing 
> this I accidentally lied...I had forgotten that even though I did buy 
> an exposure setup and photoresist boards, etc., I never tried using 
> that method...because the cost of those photoresist boards seemed too 
> high to me.
>
> So....go crazy on the toner transfer method until I get it RIGHT, or 
> go with photoresist and accept the higher cost of the boards....
>
> Any consensus on this?
>
> Very Best, Charlie
>
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>
>