Electronics Forum | Tue Jun 03 01:03:04 EDT 2008 | daxman
Hi, I think what you are describing is a half-etch QFN, which causes the 3 mil gap. In our process, we don't require solder to bridge this gap as it's internally connected to the bottom lead. I'm not sure if this is the question you're asking, but
Electronics Forum | Mon Aug 14 13:51:37 EDT 2023 | calebcsmt
I'm actually currently in the process of discussing with stencil MFG regarding the apertures and reduction to see if perhaps it was not optimal for this fine pitch QFN, as just as you mentioned, we have similar products with similar QFNs that do not
Electronics Forum | Wed Nov 15 12:52:21 EST 2017 | georgetruitt
IMO – Look into nano-coatings for your stencil and radius all square apertures This should help out with solder paste releasing from the stencil helping with insufficient solder QFN LGA aperture design, try a stencil cut with a few different apertur
Electronics Forum | Mon Apr 09 14:53:19 EDT 2007 | flipit
Hi, We were running with few defects with lead solder paste. The lead solder paste with stencil 0.010" X 0.020" and 0.004" thick stencil produced near defect free PCB assys. 0.010" X 0.020" (0.004" thick) lead = defect free 0.010" X 0.020" (0.005"
Electronics Forum | Mon Aug 14 01:29:49 EDT 2023 | calebcsmt
I have noticed on a recent project, the QFN and SOP solder deposits do not seem very uniform and have been leaving little balls, whiskers and icicles of solder paste coming from some pads which leads to bridges. https://imgur.com/a/lqw5RF1 I have u
Electronics Forum | Tue Sep 14 17:06:25 EDT 2010 | asksmt
Hi All, I have designed 4 Layer PCB with one 28 pin QFN PKG. I have got complaint from Production that the pads which connected to thermal pads (gnd) thru trace is bridging with solder and because of this bridge, pins are not getting soldered prope
Electronics Forum | Mon Oct 07 22:06:43 EDT 2013 | action_101
I successfully inspect solder on plcc's with angled cameras on the yestech we have. In the past I have successfully inspected for solder with angled cameras on mirtec machines for both plcc's and qfn's. Other than inspecting solder on those two types
Electronics Forum | Fri Mar 26 11:31:34 EDT 2010 | rway
I have been using ICT for a number of years. It is still a viable resource for catching defects in the production process. AOI doesn't catch everything, such as bridging on QFN or J-lead devices (this will depend on the type of AOI and camera syste
Electronics Forum | Mon Mar 25 21:50:10 EST 2002 | davef
Some of this was copped from Fred. There are numerous package types that now fall under the rubric of land grid array [LGA]. Land grid devices [ie, Bumped Chip Carrier� [BCC], LGA, Quad Flat-pack No-lead [QFN], MicroLeadFrame�, etc] are essentially
Electronics Forum | Wed Oct 03 23:58:23 EDT 2018 | gaintstar
Flason SMT News: http://www.flason-smt.com/new/6-Things-to-Check-Before-Submitting-Your-PCB-Design-for-Manufacturing.html http://www.flason-smt.com/new/about-wave-soldering-machine-tin-pot.html http://www.flason-smt.com/new/Advantages-of-Design-for-
