Electronics Forum | Thu Feb 19 12:52:08 EST 1998 | Earl Moon
| what is your experience about the presence of the voids in the joints ? | Are they dangerous and when ? My specifications require rejection and study if voiding exceeds 2% of solder joint volume measured using x-ray and/or x-sectional analysis. My
Electronics Forum | Mon Feb 03 22:48:00 EST 2003 | vinesh
Hi all, We are using small CSPs (10x10mm) in one of our products which has a big ground pad in the center (7x7mm). The maximum voiding allowed on this big pad is also no greater than 25% which we are finding very hard to achieve. The centre pad ha
Electronics Forum | Wed Nov 14 10:51:34 EST 2007 | mumtaz
Yes. Baking boards is best. Hitting the hamer on the head!
Electronics Forum | Mon Jun 17 13:07:11 EDT 2002 | Robert Hartmann
Can anyone point me to a specification or paper describing the existance of voids in transfer mold epoxies during CSP assembly? We have found very small bubbles in our process, but cannot find any information as to whether this is acceptable, and if
Electronics Forum | Mon Jun 17 21:31:23 EDT 2002 | davef
Most of our discussions here on SMTnet have focused on underfills. With transfer molding, voiding near the die, wire bonds, or leads contribute to more failures than others. Try: * Tim Chen, Cookson Semiconductor 800-223-9057 * Ron Molnar, Abpac In
Electronics Forum | Tue Nov 13 12:25:12 EST 2007 | gradloff
I have a thick board with ground planes that will be soldered by hand with a mildly active solder/flux. X-ray confirmed that solder was added to the top of the joint causing a void between the bottom and top solder joint. Other than the mildly acti
Electronics Forum | Sat Jan 16 03:06:36 EST 1999 | Wirat S.
| | Our spec on voids is 30% ball diameter in the center. On the component to ball and pad to ball interface, we use 25%. To determine this spec, we asked around. I don't know of any studies that have been done to verify if this is OK | | | | Regard
Electronics Forum | Fri Feb 07 15:17:14 EST 2003 | MA/NY DDave
Hi I am pretty sure it isn't the pad that is causing the problem. To me it seems like those via holes through the pcb either to an internal plane or to the other side. I can imagine creating an interesting stencil to accomodate the vias yet you are
Electronics Forum | Fri Feb 07 16:10:14 EST 2003 | MA/NY DDave
Hi Gee, It seems funny to comment on your own post. I notice that the original poster and a respondent, like me, are striving to create some voiding by design to improve the way this joint will form. NEAT!! I still think that those vias as DaveF p
Electronics Forum | Wed May 16 11:34:55 EDT 2001 | b123084
I am looking for a conformal coating to protect a PWB that will be completely submerged in water. Unfortunately polyurethane will not work because it will not fill all of the small spaces and leaves voids.
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