On Mon, Jun 02, 2014 at 10:24:22PM +0100, John Beard wrote: > But if it were, it wouldn't be part of the actual board, or have I > misunderstood? So it wouldn't increase the actual cost of a unit, but is > rather used for having a reference document to hand (presumably > partnered with the BOM)?
Yes, it's only for assembly documentation (for checking the pick and place machine and/or manual assembly reworking) > PicoBlades. I think a lot of people using KiCad (like me) are not using > very advanced fabrication technologies! Seems a good starting point to me. Also advanced fabrication requires often custom-made modules anyway. > >There is another reason for courtyard excess, namely reworking > >clearance. BGAs have extra courtyard because the desoldering nozzle is > >big! > > I was thinking more of last time I tried to manually hot-air reflow a > joint that was too close to a plastic header and melted it out of shape. > Why make those out of such low-melting-temperature and combustible > material, I ask! ;-) Because it's designed to run on a wave solder, usually (and anyway peak reflow in the oven is 260°C, while hot air is usually in the 300-380°C range)... also you can lower the needed hot air temperature preheating the board to about 100-120°C (aoyue makes good stuff for that :P) and/or heat shield the delicate parts (there is special tape for that but scrap FR4 pieces are good enough). -- Lorenzo Marcantonio Logos Srl -- Mailing list: https://launchpad.net/~kicad-lib-committers Post to : kicad-lib-committers@lists.launchpad.net Unsubscribe : https://launchpad.net/~kicad-lib-committers More help : https://help.launchpad.net/ListHelp
