Homebrew PCBs

On Fri, 12 Jan 2007 11:01:02 +0100, David McNab <rebirth@...>  
wrote:

> * gloss-inkjet.jpg - toner transfer via inkjet gloss card
> * washaway.jpg - toner transfer via washaway paper, fed directly into
>   laminator
> * washaway-card.jpg - toner transfer via washaway paper, enclosed in
>   thin card prior to feeding through laminator
> As you can see, the inkjet gloss gives much better resolution, even
> sufficient for SMD boards. The WashAway paper gives much uglier toner
> transfer, but adequate for simpler boards with larger traces and
> through-hole components and taking much less time to create.
> Cheers
> David


Hi, the list does not allow attachments, please upload to the group or use  
something like www.tinypic.com and provide the links.

It is good to hear someone tried this paper, but i think you should work  
on the soaking/peeling process. That should not take 15 minutes. I have  
never timed it, but i would be very surprised if it is more than 2 or 3  
minutes for me. I will describe how i do it:
After the board comes out of the fuser i'll put it flat on a table, and  
brush the paper with a brass wire brush ("spark plug brush"), only 2 or 3  
times, just to scratch it. While still hot i'll throw it into a container  
with water in it. At this stage you can leave it as long as you like (e.g.  
if you have more boards to make), soaking will make it go slightly easier  
later on. But if you don't have the time you can take it out after a few  
seconds, and start to rub in the center of the board. Soon a layer of  
paper will peel off and "roll" under your thumb. Roll this layer off over  
the whole board, now you should still have a thin paper layer left that is  
virtually dry. Dunk it into the water again to wet it, and start rubbing  
"through" in the middle of the board. Now you can "roll" this last layer  
mostly off the board as well. Now most of the paper is gone, but there  
will be some remains between tight traces and stuff. Dunk the board again,  
and rub it firmly either with your finger or with a piece of foam (foam  
rubber works just fine). After this dunk your board to rinse, dry with a  
towel, and blow on it or set it on the residual heat of the fuser to dry.  
Drying makes any remaining paper very obvious (white). Remove any paper  
you spot by localized rubbing with the moistened foam. ready.

Seems like lotsa steps, but i'm sure this is only a matter of a couple of  
minutes. I do the major "rolling away" of the paper layers holding the  
board above the paper bin, so that i don't have to clean up and the water  
container isn't filled with paper fragments.

I will time this when i make the next board, in a couple of days.

ST