Electronics Forum | Sat Feb 26 20:44:46 EST 2005 | siverts
Some of the QFN's have/has? (sorry for the grammatics but I live in Sweden) a "ground pad" underneath the center of the body. Some of the manufactories have made a specification of how much solder fillet that needs to be covered on the center pad [f
Electronics Forum | Tue Mar 15 09:46:06 EST 2005 | davef
Comments are: * J-STD-001 and A-610 committees have eliminated the requirement that solder joints be "bright and shiny". Certain metallizations (such as gold) can influence the solder joint surface texture, but have no impact of reliability. Reliance
Electronics Forum | Tue Mar 22 07:39:05 EST 2005 | davef
There is no standard. This is a relative test. If you wish to do tests of this kind, we suggest to pay attention to the following points: * Shear strength of soft solder depends on the deformation speed applied. The faster the material is deformed t
Electronics Forum | Thu May 05 09:50:29 EDT 2005 | patrickbruneel
Hi Hannu, You just gave a very realistic and practical view of the lead-free dilemma. The main reason that your coil coating doesn't get removed is because of the inability of lead free alloys to wet the surface and conduct the heat. Higher temperat
Electronics Forum | Tue May 17 08:00:26 EDT 2005 | Bob R.
We went through this with one PBGA supplier recently and they were able to get the problem under control by fixing some of their molding processes that were inducing residual stresses. You can really see it in a thermal moire where you measure warpa
Electronics Forum | Tue May 24 19:35:36 EDT 2005 | davef
Certainly, most often, the focus of pot analysis is directed at controlling impurities. Maintaining proper level of tin is important, also. When the portion of tin decreases: * Liquidous temperature increases. * Ability to wet decreases. * Solder c
Electronics Forum | Wed Jul 13 09:19:11 EDT 2005 | Rob
Good question - lead itself isn't anything to do with global warming - it's main issue in europe is leaching into the water supply, as we bury our trash then build on it & store our drinking water in it, as we have a much greater population density t
Electronics Forum | Wed Jul 27 11:28:55 EDT 2005 | jh0n!
This may be completely normal, but I'm not used to seeing this with our old SnPb. I'm setting up reflow profiles for a SAC305 alloy, and it seems that on some of our larger pads, the flux seems to pool in the center. Is this perhaps a sign that I'm
Electronics Forum | Fri Aug 05 11:32:29 EDT 2005 | saragorcos
Hi Sandy, Here are some suggestions for an optimum cleaning process for cleaning under BGAs if they are assembled to the board to add to the great tips Shean already listed: - Use a good saponifier w/ DI water - an effective saponifier will be able
Electronics Forum | Fri Aug 12 09:50:19 EDT 2005 | fctassembly
It is true that the SAC alloys are very aggressive to unprotected solder pots but the SN100C lead free alloy can be used in these pots IF they are not already being wetted by your SN63 alloy. FCT Assembly offers a program that includes free tin wash
