-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi
> I'm thinking of switching from toner transfer to photomask. Then, I > can drill the board first and use the holes to line up the print. I've been using masks almost exclusively to make my boards. I don't think that drilling holes for components before exposure is a good idea. If you drill before applying the photoresist, you will get uneven thickness around the holes due to surface tension. On the other hand if you drill the board when the photoresist is already there you risk damaging it. At least the "positiv 20" I'm using is very soft even when dried with hot air and you can easily scratch it (when etching double sided boards I stick little bumps on the board to protect its surface from the bottom of the container with acid) What I do is drill two pilot holes before applying the photoresist in the unusable border around the circuit and use them to align the masks before exposure. It's not perfect though and I have experimented a bit with some other techniques (for example aligning the top and bottom masks before slipping the coated board between them). Best regards Tomaz -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGI7shsAlAlRhL9q8RAvHLAJ4/26QK4R32SgmIpnOlFWixWAmLKACfSvkB QohEifmFD/4s9P2UJv3IRwo= =WhoF -----END PGP SIGNATURE----- _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user