Homebrew PCBs

Markus Zingg <homebrew-pcb@...> writes:
> Were you using dryfilm resist laminate?

No, toner transfer.  Packing tape on the back side.

> What's the thickness of the brass sheet?

It varied from 2 to 5 mil.  I've been favoring the thinner stuff.

> Does this not lead to too much solderpaste on the pads?

Yes, thicker means too much paste.  A 5 mil thick sheet vs a 8 mil
wide opening is a big chunk of paste.

The other issue is thickness of the brass vs the space between pins.
The undercutting is significant in this case; the holes end up being
wider on one side than on the other; sometimes the undercutting can
connect between openings.  In general, an N mil thick sheet will be N
mils wider on the "near" (toner, photomask) side.