Electronics Forum | Thu Sep 03 12:03:52 EDT 2009 | Sean
Hi All, I have few questions about creeping corrosion that potentially happen on lead free immersion silver PCB as below: 1) What test that we can conducted to verify whether the failure we seen is due to creeping corrosion? 2) I heard that lead fr
Electronics Forum | Fri Oct 09 13:37:55 EDT 2009 | tstrat
We are seeing similar issues. We have a board that consistently has failures on a BGA part. After SEM/EDS it was shown that the fractures were occurring between the Ni-P and Ni-Sn intermetallic in the ENIG finish. The element map showed elevated conc
Electronics Forum | Thu Oct 01 07:03:55 EDT 2009 | davef
We doubt that Humiseal 1A33 is causing opens in your assemblies. We'd guess the opens occur earlier in the process, but are not hard failures. So, you pass your tests. When applied, the conformal coat flows into the gap in the ball crack and insulate
Electronics Forum | Thu Oct 08 01:07:46 EDT 2009 | tpappano
I have used 1A33 for many years with excellent results on through-hole pcbs in equipment subjected to very hot and very cold environments. Because 1A33 continues to harden with time, I assumed it would simply not be usable on smt boards, cracking t
Electronics Forum | Wed Sep 30 13:10:49 EDT 2009 | spitkis2
Hi guys, Can someone please clarify whether adjustment of Z axis travel is a critical parameter during placement of QFN devices. If so, to within what tolerance? In other words, should a pick and place machine position a QFN down on the board so t
Electronics Forum | Tue Oct 20 18:53:13 EDT 2009 | fdbittner
Having some issues with 56 contact TQFN. This is low-run prototype situation so no second chances - unfortunately. Part is 5mm X 11mm with .30X .63 perimeter lands and 2.5 X 8.5 thermal pad in center. Issues noted are intermittency at test (basica
Electronics Forum | Fri Nov 06 09:31:20 EST 2009 | adlsmt
Sounds like your contract assembler has some serious issues. You should not be getting defects anywhere neer that amount. If you do decide to go that route again find one with a good AOI machine at a minimum and you should also supply them with a fun
Electronics Forum | Wed Nov 04 07:39:34 EST 2009 | vetteboy86
We have started using an RGB LED and today ran the first boards down our line. I noticed an immediate issue with placing these. I'm using a quad QSP-2. The part sticks to the nozzle. The nozzles are clean. I have adjusted machine handling so that vac
Electronics Forum | Fri Dec 18 09:27:51 EST 2009 | sforman1
Tom: Once again - why are you using solvent based conformal coating. 1B31 is OK as a CC but it contains Toluene and MEK!! It is only 35% solids which means you are trying to get rid of 65% solvent. If you must use it due to customers requirement then
Electronics Forum | Wed Dec 23 09:11:56 EST 2009 | lynn_norman
In a former life, we used hi temp solder. I've heard of adhesive and taping methods, we just never used them. We too had a "golden" assembly that we would use for routine profiling. Our requirement was to attach a TC to the lowest thermal mass, hi
