Homebrew PCBs

On Fri, 03 Jun 2005 16:12:36 +0200, Philip Pemberton  
<philpem@...> wrote:

> Hi folks,
>   Has anyone done any testing to see if it's possible to go down to 12/12
> track width/spacing with the Staples photo paper (or PnP Blue)?
>  I've got a double-sided PCB here that won't route (without a stupid  
> number
> of vias) in anything above 12mils. If it's not possible to go down that  
> far
> with the Staples paper and a 600dpi laser, I'll send the boardfiles off  
> to
> Olimex. Otherwise, I'll try and make the board myself
>  While I'm at it.. has anyone got any tips for aligning the two transfers
> for top copper and bottom copper?
>   Also, does anyone know if toner is conductive - I was planning to put a
> placement guide on the top layer, but not if it'll end up shorting  
> everything
> out.
> Thanks.


12/12 should be no problem. maybe route 8/14 'cause of spreading.
The problem is to get the paper residue out of the small gap. I'm glad  
that task is avoided with silicone paper.

Aligning, see recent posts, use a folded sheet of thick paper / thin  
cardboard, align papers, slide PCB in, slide in cardboard, feed folded  
edge first.



I often use toner for legend, and so far i was not able to measure the  
resistance. might try harder one day...
pretty isolating. I think developer would be more conductive.


ST