On Sun, Dec 23, 2007 at 05:08:55AM +0100, Igor2 wrote: > On Sat, 22 Dec 2007, DJ Delorie wrote: > > > > >> http://ad7gd.net/geda/panelusb-sm.jpg > > > >Am I the only one who tries to make the absolutely smallest board I > >can still fit my parts on? My latest board would fit in the blank > >spots between your chips.
Most of the size of the board is due to the width. Those edge connectors (in the photo it's the near side) will actually be exposed from the device when it's done. The connectors on the far side and the left are internal. It could have been narrower, but not enough to significantly change the price. Not to mention the layout started with a fixed price for 60 square inches. Big area made it easy to keep the analog section away from the digital noise, too. > Btw, how do you guys solder those big SM chips with so many pins? That's the funny thing. The soldering on the QFPs is so much nicer than most of the 0603s because I do it bathed in flux. You just line up the chip, tack two corners, and then use the tip of your iron to drag a tiny ball of solder slowly along the pins. For the 0.5mm stuff I take no chances and I bathe it in liquid flux (and add more if I get any solder bridges). For fatter stuff (0.65mm or 0.8mm ) I'll just slather on flux with the pen. The downside is that I have to wash the board after using the liquid flux, but it's worth it. John Griessen wrote: > Hey, that's a lot of function you got going! Well heck, I'm a software guy. Now that I have the board, it's all downhill! BTW, I've decided that 0.1u caps are the hardware equivalent of semicolons... There are 128 caps on that board and 79 are .1u. And I'm totally relieved to see decent picture quality out of the ADV7183B, since I followed their zillion-cap recommendations to the letter. -- Ben Jackson AD7GD <[EMAIL PROTECTED]> http://www.ben.com/ _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user