Homebrew PCBs

On Thu, 20 Oct 2005 22:51:20 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

> 1) Rubber or some other material that gives to compensate for board
> thickness variations

Yes, some silicone rubber maybe. I guess one could take RTV silicone and  
spread it evenly.
Or a baking sheet, maybe several if not thick enough.

> 2) un-even heat from the element - this would be the biggest problem
> to correct I believe.  The only thing that comes to mind is to have
> a thick metal plate on the heating element side of the press.  Then,
> to use it, turn it on and let it get good and hot prior to use.
> Even then, I still think there is going to be some problems with
> some areas being hotter than others.

Well, a thick copper or aluminum plate would certainly help. There are  
also heating foils to stick on a plate which should heat fairly evenly  
(probably colder at the edges). Someone here tried one of those some time  
back, and a ingenious pressing force mecanism consisting of a lever and a  
bucket with weights i think. I do not know what came of it, the machine  
was finished (i've seen a picture), but i don't know about the results and  
it was probably pre-HD crash so i can't find it.
I know for fact that the heat in things like electric contact toasters or  
waffle irons is not even.
Also, i inspected a clothes press and deemed it not even worthy of trying.  
The guys using a skillet for SMD reflow also mention a heat pattern where  
the element is.
I guess avoiding it by even heating as far as possible is better than  
fighting it. But hey, maybe it isn't even a problem...


> My brother in-law is a garage sale junkie.  I will describe to him
> what I am looking for and he will find one for a couple of bucks
> somewhere - that's worth a try
> Chris

Sure is.
I'm just frightened it brings back some of the problems i had with the  
clothes iron, so i'll stick with my fuser for now.

ST