On Tue, Oct 11, 2005 at 10:12:02AM -0400, DJ Delorie wrote: > > > The oven a 1500-watt Oster, and was $60 at Target. It's got four > > heating elements (two top, two bottom) and, as I mentioned, a > > /me wonders if it's better to only heat the board from the bottom > (i.e. move all the heating elements to the bottom). For BGAs that > would mean that the heat didn't have to go through the heat-sensitive > BGA to get to the solder balls.
Not a good idea if you want to be able to do boards with components on both sides. When doing the second side, there will be components on the bottom, and I think you would get them too hot by the time the top got hot enough to melt the solder there. I wonder -- do the real reflow ovens use bottom heat on the first side and then switch to top heat when doing the second side? Randall
