I've done the photo-resist using positive boards and the results were excellent. A bit of work with exposing, developing, stopping, stripping, ect. But the boards did turn out very nice. After trying TT again over a year ago (from reading here), I haven't done a photo board since. For me TTis so easy and the boards are excellent.
I use the Hammermil office gloss paper and HP laser printers (my 1200 at home does the best job). My board prep is simple, I use a green scrubby sponge (scotch brite pad) and Dawn dish soap. I scrub it each direction a few times and make sure the whole board has been cleaned. 1 to 2 minutes tops (file board edges first for rough spots and the sponge will last longer ;-) ). Then place the transfer on the board and I iron it. I bought a cheap $10 iron and set it on the highest setting (cotton). I iron it 3 to 4 minutes each side and press moderately hard. I like to use the rounded front part of the iron to make sure I've pressed each area but never turn the iron up on it's edge. Let the board cool a little and then soak. A couple minutes in the water and I rub off the bulk of the paper then I let it soak 10, 20 minutes (just throw it in a while) and come back and carefully rub the rest off. A little foam rubber gently rubbed will help remove between thin traces. I found it doesn't have to be 100% off, just most of the paper gone. Then into the ferric chloride for etching. I've had much better results with the ferric than with other acids, the toner seems to hold up better in ferric chloride for me.
Phil - KA0HBG
--- In Homebrew_PCBs@yahoogroups.com, 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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