Electronics Forum | Tue Mar 26 10:30:28 EDT 2019 | pavel_murtishev
Hello, Could you please tell me if there is any industry standard specifying QFN to PCB standoff after soldering? Is any gap allowed? Browsing IPC-A-610, I have found nothing. Any input would be appreciated. Regards
Electronics Forum | Thu Mar 28 13:38:35 EDT 2019 | pavel_murtishev
Davef, Thank you for the comprehensive reply. I do really appreciate your help. Regards
Electronics Forum | Wed Jul 03 09:47:39 EDT 2019 | SMTA-Pat
We have seen that vias included in the PCB under the thermal pad will give less voiding.
Electronics Forum | Thu Mar 28 13:19:14 EDT 2019 | davef
There is no industry standard for BTC stand-off height. "IPC-7093A Design and Assembly Process Implementation for Bottom Termination SMT (BTC) Components" just finished "Final Draft for Industry Review" in December 2018. It mentions stand-off height
Electronics Forum | Tue Mar 26 16:36:00 EDT 2019 | charliedci
80% on edge pads and >60% on center pad(s). So with this in mind the component body should stand off a bit.
Electronics Forum | Mon Jul 01 04:50:04 EDT 2019 | sssamw
Yes, No standard.Normally QFN supplier suggest 50-75 um (2-3 mil), but it's very hard to achieve and hard to make consistent stand-off in prodution.
Electronics Forum | Wed Jul 03 17:23:03 EDT 2019 | davef
Pavel Murtishev: Please click the link under my avatar [to the left of this message] and send me your email address.
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 | Wed Mar 27 07:01:26 EDT 2019 | charliedci
200uM seems high. I say this because typically our solder stencils in this application are between 80uM and 100uM thick which would leave the component height less than that after reflow. However if your not experiencing any shorting between pads I w
Electronics Forum | Tue Aug 26 03:14:27 EDT 2008 | zpivy
Outlook for a software? PCB Gerber File Auto Checking System(http://www.pcbpartner.com) It can translate Gerber files into standard Specifications fleetly and automatically so as to help users improve the checking efficiency and reduce the cost gr
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