Homebrew PCBs

Henry Liu <henryjliu@...> writes:
> Does the drop size matter?

A little, but as long as they're consistent you'll be OK.  It's when
you have one big one and one little one that you risk tombstoning.
Look for a diameter about half the size of the pad.  For TQFP or TSOP
parts, just run a bead along the pads and clean it up later with flux
and solder wick.

> Does it need to flat?

No.  You'll squish it down with the part anyway.

> Any links to the aluminum foil method?

Laminate UV film on both sides, expose, develop, etch (takes a few
seconds).  DO NOT STRIP.  The thickness of two films plus the foil is
just right for stencils and strong enough for a few boards.

> I saw http://www.pololu.com/ will print mylar pretty cheap.

I just used this service with good results, with 0.5mm pitch TQFPs:
http://www.ohararp.com/Stencils.html

He uses kapton instead of mylar, because the laser won't warp it.