[sdiy] Homemade doubled sided PCB - what a dif a day makes

[Jay Schwichtenberg]

Here is what we did in college (and this was 30 years ago) using photo
resist.

We'd get PCB stock about 1.5" wide and about 2" longer than the lenght of
the board.

Then we would take one layer of mask and align it against the edge of the
stock taping it down to the stock with scotch tape. Remember to get sharp
edges you want to get the black on whatever you use (vellum, overhead, onion
skin, photo film) on the mask close to the board.

Next we'd flip it over and align the other layer of mask on top of that and
tape that down. This might work for iron on too if you have a light table to
align the material.

After that we'd take a board covered in photo resist and slide between the
to sheets of mask with the stock working like a spacer. Then put that
between to pieces of glass, expose and develop. After you get the hang of it
you can do a really good job of aligning things up.

Hope this makes sense and helps.
Jay

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Peter Grenader
> Sent: Monday, November 10, 2003 7:34 PM
> To: synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] Homemade doubled sided PCB - what a dif a day makes
>
>
> OK, I am pleased to announce that it looks like I have a perfectly
> registered double sided PCB sitting in a TIN flash bath as I type this.
>
> What a pain THAT was.
>
> Interesting - I used Radio Shack Copper clad yesterday.  While I didn't
> notice if it was 2 OZ or 1 OZ copper, it took nearly 55 minutes to etch,
> just to find that half of the friggin thing was about a fat 64th out of
> register front to back.
>
> The copper clad today stripped in 7 minutes.  And thankfully, it
> uncovered a
> board that was pretty much buried front to back.  yay!
>
> Amazing - the difference in etching time.  Same bottle of Ferrite
> Chl - both
> baths new (not reused) both slightly heated to the same temporature.
>
> Anyway, I've got my board.
>
>
>