Homebrew PCBs

The other possibility would be an in line pre heater. In that case, the 
rollers wouldn't have to get so hot, as the board could be at or close 
to the fusing temperature upon entering the laminator.


On 1/1/2017 3:35 PM, 'David C. Partridge' david.partridge@... 
[Homebrew_PCBs] wrote:
>
> > For exactly one pass through the laminator, what would be the 
> optimal temperature?
>
> My modified laminator runs up to 250C and even than needs multiple 
> passes for a large 11\u201d x 8\u201d double sized 1.6mm PCB (thermal capacity 
> of PCB too high). A small 0.8mm PCB will work in one pass at 250C.
>
> Even with a metal case this is pushing the limits (I had to recover 
> the rollers with glass fibre shrink-fit and cover that with PTFE 
> shrink-fit).
>
> Overall a single pass temperature setting for a large board would be 
> so high as to kill even PTFE covered rollers, and would probably 
> overcook the first part of the board.
>
> There are more exotic roller coverings than PTFE but the price would 
> make your eyes water copiously (think hundreds of pounds).
>
> I think that a solution similar to Ancel\u2019s where the roller speeds are 
> modified and driven in a forward/backward manner is probably the best.
>
> FWIW I only do laser transfer now for the LARGE boards that would be 
> too costly from a PCB supply house.
>
> Dave
>
>