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 | 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 15 21:51:17 EDT 2000 | Dave F
Jeff: You're correct �7.1.3 of ANSI J-STD-001C states " Drying / Degreasing states the assembly may be treated to remove moisture and other volitiles." We don't bake "FR4" for love nor money. The archive are littered with threads along this line.
Electronics Forum | Tue Jun 13 21:57:01 EDT 2000 | Dave F
Todd: You say: "... solder masking between the lands of fine pitch components can cause stenciling problems and or manufacturing problems." I say: Fine pitch components without solder masking between the lands can cause stenciling problems and o
Electronics Forum | Fri Jun 16 06:24:43 EDT 2000 | Wolfgang Busko
Hi Todd, it might be a philosophical question if soldermask between finepitch pads is prefered or not. That should depend on the capabilities of a particular site and their experience. We actually prefer soldermask down to 0,4mm pitch and don�t have
Electronics Forum | Tue Jun 13 21:07:54 EDT 2000 | Keith Luke
Cunli, Thanks for the feedback on OnBoard. We will be introducing the new OnBoard Forum component page next week. There you will be able to quickly access archived OnBoard Forums, and see our schedule of upcoming events. We are still weighing w
Electronics Forum | Mon Jun 12 22:02:48 EDT 2000 | Dave F
Jason: Wave soldering is the coolest thing!!!! First, so, what�s the chemical analysis of this white res? Can you point us to either tin, rosin, or something else? Second, how do you know that you are making these white residues? Could your boar
Electronics Forum | Wed Jun 14 08:08:56 EDT 2000 | Wolfgang Busko
Hi ji tae, we had a similar problem with QFPs 0,5 pitch processed by one subcontractor. The symptoms we noticed were: - the solderjointshape and wetting looked normal - the surface had a dull gray appearance - by pushing a lead sideways with a tweez
Electronics Forum | Fri Jun 02 17:19:56 EDT 2000 | Big K
I am currently experiencing several problems with QFP's on one of our IP3's. The first problem is with QFP240 devices. We are experiencing a high reject rate with these parts when using vision type 100. What appears to happen is that the vision syste
