Electronics Forum | Thu Sep 09 05:23:10 EDT 2010 | 15009
You can reduce and almost eliminate voids and other paste related defects in LGA's BGA's, QFN's etc, by using solid solder deposit. Its been around for 24 years, 13 in the US. It is now included in the new IPC 7093 specification for bottom terminat
Electronics Forum | Wed Sep 01 10:15:44 EDT 2010 | arjan
Dear Sachu_70, During the tests we also checkt other devices, there are a few small voids visible, but they are marginal. We only see large voids in this device. During the testruns we tried several reflow profiles, but without large succes.
Electronics Forum | Thu Sep 02 05:08:12 EDT 2010 | arjan
We drilled a hole in the centre of the LGA and put the thermocouple inside, so we measure the exact temperature between PCB and device.
Electronics Forum | Thu Jan 17 20:17:55 EST 2013 | duchoang
We have got lots of voids at ALL LGA. Anyone has ideas to get rid of this issue or just minimize the size of voids ?. With the same paste, same reflow oven, looking good profile, we don't have that problem with BGA. Thanks.
Electronics Forum | Wed Sep 01 07:44:36 EDT 2010 | sachu_70
Dear SMT-manufacturer, I would recommend to also have other device joints on board X-ray inspected to understand if void formations are seen across the board or confined only to one component. If seen across, your "Reflow Profile" could be the cause
Electronics Forum | Tue Jul 02 02:50:55 EDT 2002 | ianchan
Hi mates, was going thru the IPC-A-610C Standards, and noted BGA voids stands somewhere between 10%-25% voids permissible in the solder "ball" bump, after reflow process. Was wondering, hypothetical case study, is there any specification for voids
Electronics Forum | Thu Sep 02 04:51:35 EDT 2010 | sachu_70
Seems interesting ... I am certain this could be resolved. But first one question: How did you monitor the reflow profile at this component? How and where was the thermocouple connected?
Electronics Forum | Fri Sep 03 10:52:39 EDT 2010 | arjan
Mark, Can you send some X-ray foto's of your LGA solderjoints, I am curious about the results of a marginal paste volume in combination with the Multicore LF318. Did you follow the recommandation of LT and use also soldermask defined pads on your bo
Electronics Forum | Mon Aug 30 10:17:16 EDT 2010 | markgray
We currently use this devise in one of our designs with no issues. We are using a 3mil stencil and a 45% apperature reduction. It is virtually impossible to eliminate voids but they are in an acceptable range. Solder balls are caused on this componen
Electronics Forum | Wed Sep 01 05:29:40 EDT 2010 | arjan
We baked the parts just before assembly. 2>we baked the parts and store them in 4 days in drycab (60degC, Rh0,5%)and finally assembly 3> we baked the parts and refowed them on a leadfree profile and finally the assembly on the boards. The same we als
