Electronics Forum | Wed Aug 14 18:17:32 EDT 2019 | slthomas
We are down to the last few unresolved PCBA test failures in a work order and scrambling to get them repaired and into a mechanical assembly. What we have found in quite a few of these cases are cracked 1206 MLCCs. The failed parts are all the same
Electronics Forum | Fri Nov 02 08:10:40 EDT 2007 | floydf
Has anyone ever looked into the possibility for > laser marking 1812 size X7R ceramic chip > capacitors injecting sufficient energy to cause > cracking when voltage is applied? If so, what > were the findings? We are having failures of > caps
Electronics Forum | Thu Oct 15 14:23:31 EDT 1998 | Earl Moon
| I have a problem with measling on our PCB's. We saw it on our FR4 PCB's at final assembly yesterday. Is this a defect from the board vendor or something we did in our assembly process when building the PCA's (thru hole). Could the wave solder ma
Electronics Forum | Mon Jun 18 01:09:03 EDT 2001 | Dean Stadem
Igmar, If these parts are epoxied in place, and subsequently wave soldered, I would bet you a cup of coffee that they are cracking due to the thermal shock of the wave. Typically there is a valley or dip in the temperature after the pre-heat in the w
Electronics Forum | Wed Mar 14 11:51:24 EST 2001 | fmonette
Popcorning is the common designation for defects related to the moiture sensitivity of plastic molded components, like PBGAs. The plastic body of these parts will absorb moisture from the ambiant atmosphere on your factory floor. If a critical level
Electronics Forum | Thu Sep 15 11:28:11 EDT 2005 | LeeHoMa
hi Steve/Pete, Thank for your email to affirming our current mounting and soldering flow! In fact, I also don't see any problem for the pilot run(though in small volume - 500pcs). However, the problem is - I am challenged by my customer that the AI
Electronics Forum | Thu Aug 26 08:54:17 EDT 1999 | Dave F
| Having implemented the process of handling moisture sensitive devices our logistics department tries to classify all parts according to their moisture level. | Going through datasheets wasn�t that helpfull, so does anyone know of a source for that
Electronics Forum | Fri Jul 30 17:20:09 EDT 2004 | Francois Monette
A couple of other potential issues are moisture/reflow related issues. This can include internal delaminations inside the component, potentially breaking or lifting the wirebonds. It may also induce warpage where the corners of the BGA will curl up.
Electronics Forum | Tue Apr 29 07:38:42 EDT 2008 | davef
Warpage typically (not always) kinda, sorta points to a fabrication bake induced issue that is the racking technique & may be relieved by "flat baking" under weight. Your baking at 125* won't do dip. You need to get the laminate temperature above it'
Electronics Forum | Wed Oct 03 17:06:43 EDT 2001 | davef
Yes, moisture entrapment causes solder shorts 80% of the time. Cracks occur bottom side of the BGA. Use an acoustic microscope to find the cracks. So, what makes you think your BGA are blowing-off steam? I posted a vid on SMTnet that showed the b
