On Sat, 29 Oct 2005 05:45:56 +0200, matt clement <
buckeyes1997@...>
wrote:
>
> Also are you drilling before etching, after etching? Do you etch the
> hole in the pads to guide the drill bit or not? I seem to rip alot of
> pads off during the drilling itself on both sides >< .
Your pads are too small. They are probably sized for throughhole plated
boards, where the plating "rivets" them together. For homerew boards you
need large pads. Make them oblong on stuff with tight spacing (i use
1.6mx4mm for DIL ICs.). Now they will not rip off any more, and actually
support a component as well.
I drill after etching, the drilling seems to rip off small pieces of toner
around the hole. If you can drill before transfer (of any kind), like with
a CNC, this is not an issue as the resist is put on after the hole is
complete (that's what pro shops do).
I etch out the hole in the center, but smaller than the real thing (my
software has a checkbox "guide holes only" when printing.
As for size, i use 0.8mm for most, also some 0.6 and 1.0 and 1.2 and 1.5mm.
ST