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 | 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.
Industry News | 2011-09-14 12:04:43.0
The SMTA announced a session on QFN Assembly and Reliability will take place on Tuesday, October 18 during their annual conference, SMTA International, in Ft. Worth, Texas. Andrew Mawer of Freescale Semiconductor will chair the session and Viswam Puligandla, Ph.D., Nokia (Retired) will co-chair.
Industry News | 2012-05-30 18:23:07.0
IPC Midwest Conference & Exhibition™ will highlight advances in assembly materials, assembly processes and reliability testing to help electronics companies address critical challenges in manufacturing defect-free, quality electronics
Technical Library | 2017-08-17 12:28:30.0
At SMT assembly, flux outgassing/drying is difficult for devices with poor venting channel, and resulted in insufficiently dried/burnt-off flux residue for no-clean process. Examples including: Large low stand-off components such as QFN, LGA Components covered under electromagnetic shield which has either no or few venting holes Components assembled within cavity of board Any other devices with small open space around solder joints
Technical Library | 2019-07-23 22:33:47.0
The Quad Flat Pack No Leads (QFN) style of leadless packaging [also known as a Land Grid Array (LGA)] is rapidly increasing in us e for wireless, automotive, telecom and many other areas becaus e of its low cost, low stand-off height and excellent thermal and electri cal properties. With the implementation of any new package type, there is always a learning curve for its use in design and processing as well as for the Process and Quality Engineers who have to get to grips with the challenges that these packages bring. Therefore, this paper will provide examples of the common process defects that can be seen with QFNs /LGAs when using optical and x-ray inspection as part of manufacturing quality control. Results of trials conducted on four PCB finishes and using vapour phase and convection reflow will be discussed.
Events Calendar | Mon Dec 02 00:00:00 EST 2019 - Mon Dec 02 00:00:00 EST 2019 | ,
Webinar: QFN/LGA Design, Assembly Process Issues & Reliability Failures
PCB Libraries, Inc. | https://www.pcblibraries.com/Forum/no-silkscreen-created-for-qfn_topic704_post2432.html
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