>Obtain a bottle of flux remover (I use a spray can tm CRC, with built in brush). Brush the board with the stuff, let it sit for 1 minute, blow if off with compressed air. Done. Oh, yeah, I forgot to mention using the flux remover first. I was baffled that this stuff didn't come off like it usually does. It seemed to be mostly solder balls, but not really attached to anything. I found a needle tip for the solder paste, and tried another round with the toaster oven using the smallest dot I could make. Hed a lot less deposits and solder balls, but still not really acceptable. I was able to desolder some of these components with the air pencil if I pinched the hose. Still seems like a plain ol' soldering iron works well enough for this. Good thing the lab is kinda slow today. -- Lawrence Lile "Peter L. Peres" Sent by: pic microcontroller discussion list 02/03/2003 03:54 PM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: Subject: Re: [EE]: SMT soldering On Mon, 3 Feb 2003, llile@SALTONUSA.COM wrote: *>I made another try with the desoldering iron/air pump, but without *>satisfaction. This time I stuffed copper desolder braid up into the iron *>for better heat transfer. I packed it tight, and it restricted airflow *>somewhat. Insulated the soldering iron with fiberglass braid, and cranked *>it up to 140volts, which gave me about 60 watts. I was able to melt wire *>solder easily, but wasn't satisfied with the results on the board. I am *>sure the soldering iron would burn out rapidly at this voltage. *> *>I went back to the E-Z bake method, and had some success. I had a *>thermocouple buried in my board, which made it easier to control. I baked *>it at 60C for four minutes, (actually just let the board sit in a *>preheated oven shut off) then cranked the oven up, which brought it to *>215C for over one minute. *> *>I found there was a lot of solder balls left on the board, and I had to *>mechanically remove them quite vigorously. Underneath was a good solder *>joint. I tried a toothbrush, which would not touch it, then the end of a *>needle, which scraped it off pretty well. I finally just got out a fine *>wire brush and removed the stuff wholesale. This is never a problem with *>a hand soldering iron. *> *>Do other people have to remove this stuff after reflow? Does it seem to *>take a vigorous amount of work? I would have a hard time applying less *>solder, using a syringe, I just touch the pad, don't squeeze any on at *>all. I added extra flux to the board, and I am using a combo solder, RMA *>flux. It has 2% silver content, which might make it a little higher *>temperature solder. Obtain a bottle of flux remover (I use a spray can tm CRC, with built in brush). Brush the board with the stuff, let it sit for 1 minute, blow if off with compressed air. Done. Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.