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 | Thu Jun 16 08:31:15 EDT 2005 | jh0n!
The most part I have the most difficulty with is a 16mil QFN. We found that reducing stencil thickness to 4mil, and reducing aperatures for the IC by 20%, and setting local fiducials to the IC helped immensely. We used to get 75% or more bridged ou
Electronics Forum | Fri Jun 29 10:56:56 EDT 2012 | jorge_quijano
Hi guys, I need your advise on this, I have a very uncommon PCB design (at least for me, I've never seen anything like this...) it is 32" x 18" x 0.062" and has 9 QFNs that are driving me crazy, I'm not able to get a good alignment, I can get a mediu
Electronics Forum | Thu Mar 29 14:55:59 EDT 2007 | HOSS
Hello, I searched the forums and found little specific info on LGAs with interior lands. This is not a QFN with a center pad. This is a multi-row BGA without solderballs. I'm looking for recommendations on PCB land to part land ratio, stencil a
Electronics Forum | Fri May 23 16:38:28 EDT 2008 | wayne123
Well if you are getting bridges under, one thing that we used to do was flood the part with flux and then run it back through the reflow. Keep in mind we were not a High reliability manufacturer. This practice didn't hurt OUR boards, and most of the
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 | Mon Apr 09 16:48:27 EDT 2007 | ratsalad
How wide are your pads? What paste are you using? What is your board finish? Could you please post a link to the datasheet for the component? We place a lot of MLFs, both in a Pb and Pb-free process. Our standard stencil design for MLF compon
