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 | Sun Apr 11 11:39:52 EDT 2010 | manchella
When we have sent some of motherboards for reliability testing in a tird party laoratory. It is found that when Dye&Pry is done after 600 cycles of Thermal Cycling, in LGA socket only one of the corner solder joing had 100% type 3 crack. All other so
Electronics Forum | Fri May 31 05:54:09 EDT 2019 | dhanish
What are the common cause for solder joint crack after the pcba go through Temperature cycling test ?We have seen failure on solder joint for the memory part.
Electronics Forum | Tue Jun 25 09:45:39 EDT 2019 | edhare
See also ... https://www.semlab.com/solder-joint-failure-modes/
Electronics Forum | Sat Jun 01 04:22:24 EDT 2019 | gregoryyork
Depends on lead free alloy choice as well
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 | Mon Jun 24 23:21:27 EDT 2019 | sssamw
You may need tell us the background, how PCBA being tested, the test setting and spec. Solder crack maybe due to CTE mismatch or mechanical strain.
Electronics Forum | Fri May 31 23:48:14 EDT 2019 | dhanish
Thanks Dave..My customer proposing to reduce the solder volume.Can the TCT be improved by reducing the stand-off height?
Electronics Forum | Mon Jun 03 13:01:59 EDT 2019 | slthomas
Is there any chance that the boards were mechanically stressed (for instance, installed in a fixture) before, during, or after the testing? I'm just looking for other possible root causes.
Electronics Forum | Sat Jun 01 07:22:40 EDT 2019 | edhare
Just the opposite, reducing the standoff increases the shear strain range in temperature cycling, which lowers the number of cycles to failure.
