Electronics Forum | Mon Feb 08 17:11:34 EST 2010 | woodsmt
Thanks Dave and Glenn, I have setteled on Dye for the destuctive checks, and was thinking about impedence testing at intervals during ESS. Based on the research I have been doing the last several days, this seems like a method that should identify
Electronics Forum | Wed Jan 06 09:38:59 EST 2010 | lynn_norman
Via failure could be caused by cracks in the barrel, or thin plating, or fractures in the traces leading to the vias, . X-ray analysis could pick up a fractured trace and cross-sectioning of the vias could pick up the cracks and thin plating. Secon
Electronics Forum | Mon Feb 08 09:03:49 EST 2010 | woodsmt
Looking for methods for detecting BGA microcracks without cross sectioning. Currently evaluating a new package and will be putting together a thermal stress eval. We would like to perform intermediate inspections for cracks. Once all cycles are don
Electronics Forum | Fri Oct 15 11:03:50 EDT 2010 | hegemon
Well, we got the baking part right at least. I would think that would help to rule out the barrel cracks allowing moisture escape. Plating too thin makes sense to me. In any case, do you think barrel cracking would be observable on a bare PCB?
Electronics Forum | Mon Feb 08 14:32:01 EST 2010 | davef
We believe that neither xray nor SAM will provide satisfactory results and that sectioning throughout the process will provide conclusive information.
Electronics Forum | Mon Feb 08 16:11:10 EST 2010 | glennster
Dave, I agree totally, but dye-and-pry should also be part of the evaluation. Glenn Robertson Process Sciences Inc
Electronics Forum | Mon Feb 08 20:09:49 EST 2010 | davef
Woody: Consider using test BGA with no chip in, but daisy chains that you can monitor. After soldering, run environmental tests and follow with electrical tests to determine if the product concept is good enough.
Electronics Forum | Mon Feb 08 23:44:31 EST 2010 | glennster
Woody, Daisy chain packages are definitely needed, but if you can get packages with a dummy chip inside these will provide a more accurate simulation of working components. If possible, continuous monitoring of resistance during the test will be
Electronics Forum | Wed Feb 10 12:15:40 EST 2010 | woodsmt
Daisy chained parts and impedence testing were my original reccomendation. Unfourtuantely I can not get the resources for this testing.
Electronics Forum | Mon Jul 12 00:20:11 EDT 2010 | leadthree
After a detailed check the cracking was most likely from the ICT and a variation in the length of the probes (due to wear and tear) that press down the PCB. I am very certain that was the reason.
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