Electronics Forum | Tue May 27 10:34:30 EDT 2003 | davef
Much of the ability to survive rework or thermal excursions is dependent upon the fabrication materials. The board qualification criteria under the 55110 was designed around 5 thermal heat cycles. Consider reworking a BGA in this context. BGA i
Electronics Forum | Tue May 27 11:59:14 EDT 2003 | blnorman
Is anyone aware of any reports, studies, articles on the subject of silicon contamination in SnPb solder joints. We are evaluating repair of conformally coated (silicone) boards. The fear is that we will never totally remove the silicone and once i
Electronics Forum | Wed May 28 05:31:17 EDT 2003 | dougie
Hi, Can someone please give me an IPC standard number or similar for decal design when wave soldering SMT components on the underside of a board. Hopefully a document exists detailing design rules, the components ideal attitude to the wave, suitabil
Electronics Forum | Thu May 29 10:42:40 EDT 2003 | swagner
So is it fair to say that on a moisture laden double sided flex circuit you could see an increase in tombstoning on the 2nd pass due to warpage created by delamination? In other words a 0603 for instance could tombstone due to the delaminated surfac
Electronics Forum | Thu May 29 07:06:36 EDT 2003 | stefwitt
Phil, as a rule of thumb, measuring machines (such as Zeiss, View and others) should be ten times more accurate, than the placement machine, in order to provide measuring values (CPK). AOI are meant to detect missing and wrong components, but not mea
Electronics Forum | Fri May 30 20:54:53 EDT 2003 | jonfox
Conversion refresher: 1 inch = 25.4 mm 1 inch = 25,400 microns 10 microns = 0.3937 mils 10 microns = 0.010 mm so 0.4mm = 400 microns and for s/n/g: 1mm = 3.240783e-20 parsecs (pc) Have some fun with that one!
Electronics Forum | Tue Jun 03 06:29:43 EDT 2003 | mk
Orrrrrr, you could eliminate the printing, shorting, and special surface finishes by bringing the boards in with the paste already on them. There is a process that is a much more forgiving method for applying paste called solid solder deposit. Check
Electronics Forum | Wed Jun 04 05:13:09 EDT 2003 | emeto
Hi Pete I agree with all that. But his question was "Are most people shying away from them in favor of BGA or do most people consider 15.7 mil to be "standard" technology these days?" So, the truth is people use both.QFP has advantages and disadvanta
Electronics Forum | Thu May 29 18:58:41 EDT 2003 | davef
Lead free solder is bad for the environment, while increasing product costs. The US looked at restricting lead use a few years ago, took no action, and has no plans to enact frivolous legislation like the "greens" have foisted upon the Eurolanders a
Electronics Forum | Tue Jun 03 18:34:22 EDT 2003 | Kris
Hi, There have been other studies where it was found that lead-free soloder joints are more reliable than tin-lead solder joints irrespective of test conditions. In fact the automotive industry has been using Sn/Ag for underhood applications for a
