Electronics Forum | Fri Mar 02 08:52:20 EST 2001 | markkrmp
Are your voids looking like blow holes also? Is this only occurring on the solder joints of the Thru Hole components and Via's? Or does this happen on SMD pads? My experience is that we have seen this but only with some of our older PCB's which are
Electronics Forum | Tue Apr 11 20:37:06 EDT 2000 | Dave F
Rich: Now that�s a great question!!! You�re corrrect. Primary-side temperature is the driver of the differences in the sensitivity to moisture between SMT and PTH devices that you�re finding. * Primary-side temperature for SMT ~= Secondary-side te
Electronics Forum | Tue Oct 24 08:07:42 EDT 2006 | markb
We are experiencing an issue with RoHS boards delaminating during SMT. In tyring to determine root cause, our board mfg house states the issue is with the laminate. The laminate supplier states that the board house is not taking the proper precua
Electronics Forum | Sun Aug 17 19:06:42 EDT 2014 | natashakt
Hi All, I have been looking in to some failures of PCB's in Assembly. After SMT the boards are stored for different periods of time in high humity environment (72% RH and 21.4 degrees Celsius) before being sent to Assembly to be handsoldered/put thr
Electronics Forum | Fri Jun 18 06:54:43 EDT 1999 | Paul McMichael
A user of one of our components exceeded the floor life of some plastic BGA components. They did do a pre-bake prior to SMT reflow but only 72 hrs at 40C and not the recommended 12 hours at 125C. I've recommended accoustic microscopy to look for popc
Electronics Forum | Fri Jun 18 13:30:01 EDT 1999 | John Thorup
| A user of one of our components exceeded the floor life of some plastic BGA components. They did do a pre-bake prior to SMT reflow but only 72 hrs at 40C and not the recommended 12 hours at 125C. I've recommended accoustic microscopy to look for po
Electronics Forum | Fri Feb 01 10:19:22 EST 2002 | cyber_wolf
Whoa! I beg to differ my friend. The cure profile is VERY critical in Adhesive curing, especially if your are screen printing. When you screen print adhesive you are leaving it exposed to the atmosphere for a period of time. SMT adhesive by nature i
Electronics Forum | Tue Apr 13 14:49:15 EDT 2010 | davef
90%) from the sample, and the bake time and temperature specified herein are minimums. To improve test accuracy, or to prevent heat damage, other bake parameters may be AABUS. 2 Applicable Documents IPC-QL-653 Certification of Facilities that Inspect
Electronics Forum | Mon Nov 06 12:19:25 EST 2000 | Tom Gervascio
I ma trying to get some information on possible causes and screening tests for PCB delamination. Is the main cause moisture absorption of PCB material or entrapped chemicals and or air in innerlayers that expand when expsoed to subsequent reflow and
Electronics Forum | Wed Oct 18 16:41:35 EDT 2000 | Dave F
It's unrealistic to think that two materials with the following disperant properties would have the same reflow profile. From http://www.norplex.com/Carrier.htm Physical Properties / NEMA FR-4 / NEMA CEM-1 Glass transition temperature �C / 130 / 10
