Electronics Forum | Wed Aug 03 21:20:09 EDT 2005 | Ken
CTE mismatch. X, Y, Z all expand at different rates. Cooling or heating rates will not change this CTE mismatch. Layer counts, power plane ballance, equal run lengths in x-y and copper balance all contribute. Have your supplier evaluate your s
Electronics Forum | Thu Nov 11 10:55:32 EST 1999 | KenF
Hi, could anyone tell me the maximum size of an SMD ceramic capacitor that can be assembled on a copper based substrate reliably? The SMD will be reflowed on the copper substrate. The main concern is the CTE mismatch between the ceramic capacitor and
Electronics Forum | Tue Jul 25 11:30:47 EDT 2006 | DC
Russ, we had similiar issue on the corner seperation. The board is ENIG and the part is Altera FBGA 1020 (Super BGA) and reflowed by tin/lead paste. Please comment your concern on Altera parts! Is CTE mismatch?
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 | Thu Aug 17 22:22:29 EDT 2000 | C.J. Long
Hi erverybody: I am from a PCB shop. One of our product is with 19 X 19 ceramic BGA and my customer is experiencing 0.1 - 04 % failure of open trace on cornoer BGA pad. Substrate is FR4 with TG 135 degree C and delta Tg is well below 3 degree C. Tra
Electronics Forum | Sun May 24 21:12:59 EDT 2009 | keith78
I have a problem recently to qualify QFN package on solder joint reliability. The pcb thickness stated in IPC-9701 is 2.35mm but from the in-house test, QFN surface mount on 2.35mm thickness PCB board have a short cycle to failure due to higher CTE m
Electronics Forum | Mon Aug 21 19:35:51 EDT 2000 | Dave F
Kyung Sam Park: Sure, several causes of plastic QFP package delamination, other than humidity absorption, are: * Corrosion on component leads * CTE mismatch between leads and package materials * Package material adhesion strength degradation Wh
Electronics Forum | Wed Aug 03 21:29:59 EDT 2005 | Ken
Yes, lead can promote fillet lift. In order to understand this defect you must begin looking at your lead frame mateials. some lead frames are more susceptable to this disorder. This is most likely a cte mismatch disorder. Lead contamination in
Electronics Forum | Wed Mar 22 21:27:45 EST 2006 | KEN
Find out the lead frame alloy. Cte mismatch can cause the same defect. Ran into this 3 years ago wave soldering with Tin-Copper.....okay, you caught me. I admit it. Wavemaster larry told me about this and I'm posting it under my name. Shameful, I
Electronics Forum | Thu Feb 11 08:14:41 EST 2010 | scottp
It's OK to have the daisychain done in the interposer rather than the die (and a lot cheaper) but in thermal cycling the parts MUST have representative die. That's where a large part of the CTE mismatch comes from to cause fatigue damage. Thermal c
