Homebrew PCBs

Adam,

Long time since. Nice to see you are still around :-)

If you look at the example picture I uploaded, you can see the pads of 
an LQFP164 with a heat absorbing pad in it's center. Thats a 0.4mm pitch 
part. It worked out well. As for the printer, I fully agree that here it 
really depends. If with "inkjet" you refer to a HP inkjet you are 
definately out of luck. I use an Epson Stylus C62 which was and is well 
known for it's exceptional acuracy and deep black covering miles away 
from what other inkjet printers can do when specifying "premium glossy 
paper". I heard that the Cannon Pixma 3500 which is a more recent model 
performs as well. Most people refuse to belive that there are such great 
differences between printers, but there truly are. All I can say is that 
I tried several inkjets back then, and the Epson outperformed the others 
to such a great deal that I rushed out and bought two of them to have a 
backup should the first one break!

You may want to give a Cannon Pixma 3500 a shot. It's a fairly cheap unit.

Markus


> I had attempt at stencils. The main difference between PCB and stencil
> your trying to etch 100um~150um instead of 35um. Any professional who
> etches stencils, will double side etch. I was trying to etch for QFN
> packages with 0.5mm pitch, and could not get the required accuracy. All
> the other component pads were usable. It was only this particular IC
> that caused me problems. Major factors affecting the accuracy of the
> stencil were limitation on my inkjet printer resolution and etch
> undercut. I tried compensating for etch undercut and even tried double
> sided etch, but failed to get consistent apertures for the 0.5mm pitch
> pads. In the end I paid $180 for a brass stencil , which I mounted to my
> own frame.
> For parts like 0603, 0402 , 0.65mm pitch TQFP, then I think home brew
> stencil etching is quite feasible.
>
> I was new to stencils and solder past printing so maybe someone can
> prove me wrong.
>
>