Electronics Forum | Wed Mar 24 08:36:58 EST 2004 | Evtimov
Hi! What exatly you do? Do you reflow the both sides of the board at the same time or you reflow your second side? I think in both cases you should decrease you bottom zones. If you reflow both sides - with 10-20C(F) If you reflow the second side - w
Electronics Forum | Tue May 14 21:07:03 EDT 2002 | ianchan
Hi mates, Yes, the lighter mass is a valid reasoning. in addition to the "lighter (mass) than thou" point of view, 1) the first reason for mounting active Parts (eg. IC, QFP, LGA...) is to minimize the temperature exposure of the Parts to a single
Electronics Forum | Mon Aug 13 08:00:46 EDT 2007 | davef
Are the components that fall from the board solderable? Is the board solderable? Where is the solder for the components that fall from the board [eg, on the pads, on the component]?
Electronics Forum | Fri Aug 10 14:43:27 EDT 2007 | judym
When running some double sided reflow boards through the Heller oven, some of the caps/ res's are falling off the bottom side of the board. I understand if the parts are too heavy they wont stay in the molten solder, but these particular parts are no
Electronics Forum | Wed Jun 21 22:07:09 EDT 2000 | Jason
We are going to try double sided reflow for the first time. Can we use the same 63/37 paste on both sides? The board also has bare copper pads i'm pretty sure. will this present any challenges? The bottom side has a QFP on it. Should it stay on?
Electronics Forum | Mon Aug 13 16:07:08 EDT 2007 | dyoungquist
We run double sided surface mount boards through our Heller oven without any parts falling off the bottom side unless they are too big/heavy. The trick we use is to set the bottom side temperature in the final 3 heat zones 10C-20C lower than the top
Electronics Forum | Thu Jun 22 12:25:07 EDT 2000 | Boca
Jason, What Chrys said! Don't try to run the bottom cooler, tried it in the mid 80's, don't work and don't want it to work. If one side of a fab is maintained cooler than liquidus and the other side into reflow it would have an easy 40C temp diffe
Electronics Forum | Thu Jun 22 11:01:54 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
Electronics Forum | Thu Jun 22 11:02:13 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
Electronics Forum | Fri Dec 17 09:04:17 EST 2010 | wolverine
We have an older model CP40-LV that will start out the day with blurry and double vision, then after about twenty minutes of just idling, the vision slowly improved until the machine could find the board fiducials and do a passable placement job. Th
