Homebrew PCBs

On Wed, 18 May 2005 09:11:59 -0700, Tobias Gogolin <usertogo@...>  
wrote:

> Excuse me, a question please:
> I remember having seen silicon spray might that or any other spray
> type surface treatment do similar tricks ?
> You guys are pioneering something real exciting there...
> I wonder would this work for .5 mm pitch SMD pads (that's must be
> something like 8 mil spaces and 11.68 mil pads)
> Thanks
> Tobias


I think silicone spray is the silicone oil, no?
If it is not and it hardens it would probably work.

the smd you mention would work if you reduce the padsize in the software.
Right now 10mil is the closest reliable spacing i can make before it  
bridges from toner spreading (however this will get better if i used less  
than darkest toner, must experiment more).

6.66mil is the smallest track i can etch without underetching causing  
trouble. So i would set the pad to 6.66mil, which widens slightly from  
spreading anyway, and have more than 10mil spacing left. I would expect it  
to work.

Toner transfer was the really exciting thing, this merely makes the  
process much easier. However i'm glad i had the stupid idea to smear some  
silicone on a sheet of paper with a floppy disc...


ST