Electronics Forum | Thu Mar 16 03:45:51 EDT 2017 | rob
It's the same thermal issue whether it's a die or package. It's different if it is just a signal trace, but if it's a heatsink pad (LED, FET, Motor driver, PSU IC etc). I think the voiding issue boils down to what the part is actually doing. The or
Electronics Forum | Wed Mar 15 12:39:24 EDT 2017 | cyber_wolf
Customer precedes standard, but customer must be educated and informed on what is achievable with their design and what is accepted as industry standard practice. My guess is that the negative effect of those voids is negligible. {Voids at the sold
Electronics Forum | Wed May 20 17:18:09 EDT 2009 | daxman
Just out of curiosity, how are you or anyone else determining a defect? Last I checked, IPC had no criteria yet for solder defects for QFN components. Has this changed? Biggest problems we see are voids which our x-ray shows a lot of. Our problems
Electronics Forum | Fri Sep 03 06:53:38 EDT 2010 | arjan
Yes, we assembled a lot of QFN in the last years, but we don't have a X-ray machine by ourself, so we cant't inspect each device. This type LGA was designed on a prototyping board of our customer so we would validate our LGA reflow process and a rese
Electronics Forum | Sat Jul 20 14:55:55 EDT 2019 | davef
IPC-A-610F 8.3.13 Bottom Termination Components (BTC) ... Thermal plane void criteria shall be established between the manufacturer and user IPC-A-610F, 8.3.14 Components with Bottom Thermal Plane Terminations ... Thermal Plane Void Criteria -
Electronics Forum | Wed Mar 27 04:32:49 EDT 2019 | pavel_murtishev
Charliem, Thank you for the input. Following this logic, in case if there are no soldering issues, pad coverage and voiding levels are within acceptable limits and a gap between BTC and pad let us say 200um, this could be accepted, right? IPC-A-61
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 | Thu Mar 30 21:46:56 EST 2000 | Dave F
Reg: This is copy / paste from draft version of IPC 7095 ( issued May 1999 ) ... 7.3 Assembly accept/reject criteria 7.3.1 Voids in solder joint a. Sources of Voids There can be voids in solder balls, or at the solder joints to the BGA, or at the so
Electronics Forum | Sat May 18 10:21:09 EDT 2013 | davef
isd.jww: Comments are: * Current thinking has flux volatiles being the major contributor to voiding, not scavanging by via * I have no reason to think that 0.3mm via won't gladly accept solder. Plug them, if that's a concern. * If your concern is ina
Electronics Forum | Tue Aug 31 04:05:23 EDT 2010 | arjan
Hi Mark, Thanks for your responce! The stencil thickness and especially the reduction of 45% are not recommend by LT, did you came to this combination experimentally? We never have the illusion to produce voiding free, but now its around the accepta
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