On Fri, Jul 16, 2010 at 1:35 PM, Armin Faltl <[email protected]> wrote: > First and foremost thanks a lot! > > DJ Delorie wrote: >>> >>> I somehow feared this while I wasn't sure: so it is not posible to >>> manually define the paste mask on a footprint? >>> >> >> No. What I do is use a perl script to create a "paste board" that has >> all the paste apertures as element pads, but nothing else. Then I can >> manually edit them all, and just dump a gerber for layer 1 copper as >> the paste gerber. >> >> >>> >>> I need this to create the footprint of a part with thermal central pad. >>> >> >> Use one pad for each paste spot you need, then one overall pad with >> the "nopaste" flag to fill in the gaps. >> > > If I understand you right, this is an alternative to the "paste board" > approach above. > I'll go for this and provide the footprint when I'm ready. >>> >>> Hand-soldering is a nightmare-option with 0.5mm pad-pitch ;-) >>> >> >> No it's not, I do it all the time. Even when I use a paste stencil >> and reflow, I often have to re-solder the pins for various reasons. >> Just use enough flux and a big tip and it works just fine. >> > > I've used the surface tension of the solder with relatively fine pitched > square flat packs > and "legs" with success and actual ease. The beast I'm talking about now is > this: > > http://focus.ti.com/lit/ds/symlink/bq24103.pdf > > It has the pins beneath the package. I'll extend the pads about 0.5mm > outside (longer > with traces attached) as recommended, so will this trick work again? > > Regards, Armin >
Oh, those (QFN-like) packages are quite easy to hand solder, except for the thermal pad underneath. Much easier than fragile narrow-pitch TQFP and TSSOP parts. If you don't need the thermal pad, just plunk the part on the board with flux and run a solder blob around the edges. Done. To solder the pad underneath, you need a LITTLE paste under there and an oven or hot air or a via underneath to put an iron on. You will love the leadless packages if you have ever bent the pins or solder-bridged a TSSOP part. Regards, Mark markra...@gmail -- Mark Rages, Engineer Midwest Telecine LLC [email protected] _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
