Homebrew PCBs

That puller thing makes me shiver.

I liked your board much better before...

Nice via trick with the solder.

ST

On Nov 26, 2007 6:20 PM, DJ Delorie <dj@...> wrote:
>
> Got one done:
>
> http://www.delorie.com/electronics/usb-gpio/
>
> The inner core is 1/2oz 32 mil DS.  The two outer layers are 1/2oz 8
> mil SS, taped on with 3M 7953 laminating adhesive.  TT (Pulsar), FeCl
> etch, MG Liquid Tin.
>
> Lessons learned:
>
> * Keep track of which holes are which sizes on which layers.  I got
>  this wrong in a couple of places, and had to use an xacto knife to
>  cut through the outer layers.  There were a few places I drilled
>  where I shouldn't have, but those were fixable.
>
> * My process "bloats" copper, so I need to print it shrunk to
>  compensate.  I had to "edit" the etch resist before etching, and
>  still had some shorts afterwards that I had to fix.
>
> * I still can't manually iron on toner with any success.  I tried the
>  glossy magazine paper instead of the coated paper, just to see.  It
>  seemed like it would have worked, if only the toner had stuck to the
>  board better.  There's a fine line between "does stick" and "smears"
>  that I keep passing through.  I didn't try it with the laminator, as
>  I was trying to use up some 1/16" stock.
>
> * How to do fast vias: Wrap solder around the board, to hold it off
>  the table a bit.  Cut off a few inches of bare wire wrap wire.
>  Stick wire through hole, solder, cut, repeat.  Flip board, solder
>  all the little bits of wire sticking out.
>
> * Pin 4 is not ground on mini-B connectors :-(
>
>
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