Electronics Forum | Fri Aug 06 08:38:25 EDT 2004 | Bob R.
You don't mention the board surface finish, but BGA's on NiAu are prone to brittle fracture in the Sn-Ni intermetallic on the board side of the joint. You may not be able to see it visually, but it would show up in a cross-section. In-circuit test
Electronics Forum | Fri May 31 10:15:30 EDT 2019 | davef
Major sources of crack in the solder connection after thermal cycling are: * Thermal heating caused by differences in thermal expansion between the board and the component * Lead-free solder is more rigid and brittle than eutectic solder in simila
Electronics Forum | Thu Jan 08 15:49:10 EST 2015 | emeto
I bet you that the problem comes from the ENIG brittle solder joints. About low temperatures I think you can go to the absolute 0 and the device should still work.
Electronics Forum | Wed Nov 06 03:51:28 EST 2013 | cuperpeter
Hi rob, Thank you very much for your response. Profiling was made exactly on the pad, which showed dewetting, so the values are mentioned for this pad. PCB's is about a week old. It is possible that the surface of pads is already oxidized? I will t
Electronics Forum | Fri Jun 03 15:19:32 EDT 2022 | dwl
I don't recall thicknesses off the top of my head but brittleness becomes an issue more for gold plating then ENIG. .125 um should be fine. also, gold ain't cheap so its unlikely your PCB fab will get anywhere near the max tolerance. On the other e
Electronics Forum | Tue Apr 13 08:21:05 EDT 2010 | esca
Hi manchella, After ATC test, two different failure modes can be present: solder FATIGUE (into bulk) or BRITTLE INTERMETALLIC fracture. So, first you have to verify this. Moreover, which brand of SMT paste have you used ? The crack into solder joint
Electronics Forum | Wed Aug 09 09:54:36 EDT 2006 | russ
Use ENIG, plated finish will be too thick and make for a brittle joint. ENIG is self limiting so this condition cannot be present. To ensure that the bond is strong for BGA you must ensure that process is under control. The correct reflow profile w
Electronics Forum | Mon Oct 25 15:56:56 EDT 1999 | Dave F
William: Three things: 1 If the gold is porous, it will not protect the nickel and the nichel wiil oxidize and become unsolderable. 2 If the nickel is not solderable, the gold overcoat will not improve that. 3 Ag or Au over electroless Ni creates b
Electronics Forum | Wed May 29 19:12:25 EDT 2002 | russ
If Gold gets to thick you will end up with brittle joints that break! Hard gold plating is usually about 50 microns thick (is that right?) whereas gold immersion is around 7-13 from what I have seen. i once use gold plating on an entire board and ha
Electronics Forum | Tue Mar 18 17:23:40 EDT 2008 | dkntb
Any member in here has experienced of copper migration from BGA's substrate to PWB during eutectic soldering reflow process, which resulted in brittle solder joints??? We have one customer notified us that our PBGA with DSOP substrate having copper m
