Electronics Forum | Mon Jul 30 20:38:02 EDT 2012 | davef
I'm with you on microcracking. The best way to confirm this is through sectioning of the affected capacitors. You're fortunate to be seeing these failures showing-up early in your product life. Of times these failures don't appear for years.
Electronics Forum | Wed Aug 22 12:44:26 EDT 2012 | rway
I would look at your de-paneling process. How are you cutting the boards? This could be inducing mechanical stress on the component; especially if the part is close to the edge of the pcb and perpendicular to it.
Electronics Forum | Wed Aug 22 13:16:23 EDT 2012 | rway
Most likely the depaneling is not your issue, but I do concur that there is some mechanical stress occurring somewhere. What about any fixturing for FT/ICT?
Electronics Forum | Wed Aug 22 12:48:47 EDT 2012 | tpatrickwalsh
They are using the method where scored boards are separated using a rotating wheel / blade. I realize this is not the best process, however these capacitors are more than 10 mm from the edge of the board. From some reading online I think that means
Electronics Forum | Wed Aug 22 13:18:50 EDT 2012 | rway
I also forgot to mention that the pizza-slicers you are using can get out of spec and may need periodic calibration. By cutting too close, these can over-stress your pcbs as well. Do you only see this problem at one cutter or does it matter? Also,
Electronics Forum | Thu Aug 23 00:38:17 EDT 2012 | isd_jwendell
"The problem is we haven’t changed anything in our design, and this has never happened before in 4-5 batches of production." If nothing has changed (same parts, same oven profile, same de-paneling, etc.), could the parts themselves have changed? I h
Electronics Forum | Mon Aug 27 04:13:49 EDT 2012 | thmeier
Moisture should not be an issue with ceramics, but mechanical or thermal stress definitely is. Has there been rework on this capacitors? So check for handling /temperature of your soldering irons (better:use hot air). Check oven temperature/profile
Electronics Forum | Fri Jul 27 12:21:18 EDT 2012 | tpatrickwalsh
I am posting this here because I think it may have something to do with PCBA: I have a simple battery-powered consumer product (LED light) that we have been manufacturing for some time. All of a sudden in one batch, we have about a 4% rate of a sing
Electronics Forum | Fri Apr 30 07:39:54 EDT 2010 | jdengler
We do a similar part on a Fuji IP3. Set table speed to low. I do not know the QP, but if it's similar to the IP make sure the board clamp/unclamp is smooth. On our IP it got dirty and was jerking causing the board to jump a little which bounced ou
Electronics Forum | Wed May 05 15:27:06 EDT 2010 | bradlanger
Make sure that both lead frames are contacting the PCB pads when the part is on the placement head. We had an SM xfrmer that we were handling with vacuum by a ferrite cap that was not glued on straight. The part would contact one set of pads and get
