Electronics Forum | Tue Sep 09 15:10:01 EDT 2003 | swagner
Has anyone had negative experiences with hasl thicknesses below .00005'' of an inch on copper? If so could you please respond with what the problems were. Thanks in advance!!!
Electronics Forum | Wed Sep 10 09:32:56 EDT 2003 | swagner
Dave F, so what kind of problems would I see if this turned into a problem?
Electronics Forum | Thu Sep 11 09:22:27 EDT 2003 | swagner
Is there any conceivable way this could cause a tombstoned device?
Electronics Forum | Fri Sep 12 09:10:23 EDT 2003 | Norm Morikawa
Around 1989 I had this probelmm with a SMT CCA that would not solder in one area consistently. I had it cross sectioned by the bare board supplier and found that under their metallurgical microscope the thickness of this HASL bare board could not be
Electronics Forum | Fri Sep 12 13:14:33 EDT 2003 | Mark Kostinovsky
A little adition to Norm's statement: Sn-Pb intermettalic compounds do not accept solder as they are (even without being oxidized).
Electronics Forum | Tue Sep 09 18:07:18 EDT 2003 | davef
We would be very wary of allowing 50 uinches, because this will likely result in reduced shelf life due to intermetallic growth. As a guesstimate, at least 10 uinches of that 50 uinches, and maybe more, is already intermetallic when you receive the b
Electronics Forum | Wed Sep 10 12:56:09 EDT 2003 | davef
Intermetallic compounds [IMC]: * Form during the alloying process of some metals. In soldering these are Sn, Ni, Ag, Cu, Au. * Do not accept solder. * Increase in depth in logarithmic proportion to both time and temperature. [So during the solder
Electronics Forum | Thu Sep 11 16:50:18 EDT 2003 | davef
Sure it's conceivable that thin HASL can cause tombstoning. Harkening back to the ample discussion in the fine SMTnet Archives, tombstoning is caused by an imbalance in solder surface tension between the two pads of SMT component. The source of thi
Electronics Forum | Mon Apr 23 14:59:56 EDT 2001 | relensky
I have been using pallet from Integrated Ideas and Technologies (www.integratedideas.com). They offer a "laminated" pallet that can have the various layers cut in several thicknesses. They are very helpful and willing to solve problems. The best p
Electronics Forum | Fri Sep 21 01:31:13 EDT 2001 | Stoney Tsai
Guys, If there are any specifications or ciriterions for solder paste deposition thickness and volume evaluation. For example, QFP (0.5 mm pitch), 6~8 mils, 3000 mil^3 PLCC: 8~10 mils, ... . . Thanks in advance. Best Regards,
