On Sun, May 1, 2011 at 2:39 AM, Wouter van Ooijen wrote: >> So I was wondering...has anyone here tried either technique? Any >> advice or comments? > > I have done a few 100's of boards in my toaster oven. I added a > temperature profile controller ( pt1k sensor). The result needs some > checking, probably because my oven has no fan. > > For hand-pnp I use a curved metal tweezer. I tried some cheap suction > type thingies but they are no good. > > The smallest pinned chips on my boards are FT232RLs, which sometimes > requires removal of excess solder. Probably because I use a very cheap > stencil, which I should replace by now. Go to the hardware store and buy 0.003" brass sheet stock. ( 0.08mm for you metric achievers.) Then you can etch holes in it using normal hobbyist PCB processes. A metal stencil is much nice to use than one made from mylar or kapton. I think hobbyists worry too much about temperature profiles. If you are a manufacturer building thousands of iPhone circuit boards, then having a few bridged pins or tombstoned passives on each board is a complete process failure. For a hobbyist, its no big deal to fix up a couple minor issues per board, and probably a lot easier than futzing around with PID controllers and ramp rates. (I admit building a controller sounds kinda fun.) I use a $20 toaster oven using the same temperature profile recommended for bagel preparation. It works fine. For double sided boards, or heating a small portion of the board for QFN rework, I have some chunks of aluminum I arrange over the board to absorb heat in the places I don't want the solder melted. Lead-free solder is trickier, because the window between solder-melted temperature and pcb-damaging temperature is smaller. Regards, Mark markrages@gmail --=20 Mark Rages, Engineer Midwest Telecine LLC markrages@midwesttelecine.com --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .