Homebrew PCBs

You guessed right, relatively thin cardboard. maybe 0.5mm. Like the big  
parts of cornflakes boxes.

Again, the procedure:
You cut your layout pretty close to the board edge, but with 2cm border on  
one side (same side both layouts).
Then you put together the toner sides, and slide around holding against a  
light until it matches.
Now you should have prepared that cardboard, folded in the middle, well  
larger than the PCB, because you open the folded piece with one hand, and  
slide the layout in with the excess border towards the folded edge. Now  
you hold the three pieces together with your other hand, from the outside  
of the cardboard, on the folded edge. This allows you to slide the PCB in  
and position (this is why you had to cut it close to the board outline on  
all but one side, makes positioning easier). Let the cardboard close and  
simply hold the stack together (pressing at the PCB). Feed the whole thing  
folded edge first. Depending on your fuser you might want a second pass  
flipped over, or even two more runs with the cardboard missing. The paper  
should be stuck fast by now.

The strange thing is, if you do this without the cardboard the fuser will  
"drag" one paper forward, at the board edge. If you imagine the papers  
beeing together with zero distance before the board, and 1.5mm then,  
there's a 1.5mm length to be taken from somewhere. With the cardboard  
feeder, although it makes a crease in it where the board starts, there  
seems to be no such movement.

The fuser could easily take the added thickness without modification,  
dunno about other machines. But you can also tack it with a iron if you  
run into trouble. Then you needn't even use the cardboard, as the iron  
doesn't move anything.

ST

On Thu, 17 Nov 2005 04:09:12 +0100, Ron <mnphysicist@...> wrote:

>
> Could you elaborate on the folded cardboard? I'm having a problem
>
> visualizing exactly what you are doing. I'm assuming you tape the
>
> copperviews to maintian alignment, and then slip them into the folded
>
> over cardboard to hold them and the pcb laminate static during the 2
>
> passes through the laminator.
>
>
> Also, did you have to mod the laminator to deal with the thicker
>
> stack? Then again, I tend to think of cardboard as 3-4mm thick,
>
> perhaps what you are using is thinner.
>