Homebrew PCBs

> >Anyone worked with copper foils? Got any sources for getting hold of
some?
> 
> you can get it at various handicraft stores like, Hobby Lobby, and
> such . sometimes in the leaded glass section. they also usually have
> in it in adhesive tape of various widths. intriguing notion, but
> can't see worth the effort except as personal cool self expression
> and enrichment. to drill glass, you must continually spray with water


Foil typically comes in 10 metre (33') rolls, with widths from about 4mm -
10mm.  The sizes are related to the thicknesses of glass, the copper is
stuck to the edge for the glass and folded over, like [.  Most glass is 3mm
thick.  

Note that the foil comes with different colour backing, that is the adhesive
side may not be copper.  You can get copper (i.e. plain), silver & black.
When doing stained glass the different colours provide different effects,
you can see this side thru the glass.

The adhesive will stand up to soldering for a short period, but it will lift
if overheated.  This is bare copper, so you'll need to clean & flux it
before soldering.  Normal rosin core solder will work fine (I'd still scrub
it first) but the flux can be hard to get off.  You're not likely to crack
the glass, 100 watt & over irons are normally used.  Don't use a torch, you
will crack it then.

I wouldn't use SMT components, I'd simply use normal thru-hole components
and push the leads down, for chips bend the leads out.  This solves the
problem of drilling.  If you want to drill, drill first them apply the tape.

Since chips pins are on a 2.54mm (1/10") pitch, the tape is too thick to use
as is.  The thinnest glass is 2mm (for picture frames), and tape to match is
about 4mm wide.  There is thinner stuff, but it's hard to find.   You'll
have to lay out the tracks to allow for the thick tape, and then trim the
ends to meet up with the chip, angling it in to line up properly.

Otherwise you can cut it to size yourself, much like how a vinyl cutter
(drag knife) works.  Set up the tape to run thru a roller guide, and
position a blade so it cuts the tape, but not the backing.  Of course,
easier said than done.  :)

Tony