Electronics Forum | Fri Mar 19 12:22:36 EDT 2010 | stepheniii
Could it be a CTE mismatch issue?
Electronics Forum | Tue Jun 25 01:24:25 EDT 2019 | sssamw
That is possibley CTE mismatch between QFN and PCB material, the thicker PCB the higher fail rate.
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 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 | Wed Jun 29 17:38:16 EDT 2005 | GS
Several years ago, we had almost same pbm, best results have been obtained by using water soluble paste (those time the old AM1208). Any way, to get a good toe meniscus is not so easy. Talking about CTE, keep in consideration the internal die of TSO
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 | Thu May 26 21:07:22 EDT 2005 | KEN
This is caused by cte mis-match. The balls in the corners are short and fat. The balls near the null point are tall and more normalized. I don't remember what the zone settings were... BTU VIP98 BS was probably 22-25 IPM
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?
