[sdiy] My PCB positives are see through!

[Tom Arnold]

On Tue, Dec 13, 2005 at 05:12:30PM -0500, Jeff Farr wrote:
> I guess it's possible that this isn't a big deal, but I just got my
> prints back on transparancies for etching a few boards and, despite
> having them done at high quality, I can see right through the ground
> plane when I hold it up to any light.

I do this all the time for making front panels and I've done a couple
positive film boards ( I'm still making the transition to that ) without
problem.

One thing to keep in mind when doing this, make sure you do the images
backwards so you lay the toner side directly on the board or you'll get
shadows.

If you are ultra paranoid like me, sacrifice a little scrap of pcboard,
print out roughly  3  4  5  6  7  8  9  10 or some range of numbers
bracketing the suggested time cover everything but the 10 with something
opaque and start exposing, sliding down once a minute.  That way you can
find the best time for your particular setup ( for me its 8-9minutes. ).

I print my films on a standard laser printer using 3M transparency sheets.

I used to print on paper then get a good printshop to do a photo transfer to
film, but thats un-needed these days with a good laser printer.

-- 
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 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -
 - BBD Fanatic      -  "...is it a virus, a drug, or a religion?" 
 - echo evho wjxo   -    Juanita Shrugs. "What's the difference?" 
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