Electronics Forum | Tue Nov 11 16:30:08 EST 2008 | naynayno
Occasionally solder mask thickness is believed to be the cause of gasketing challenges during paste printing. We currently specific IPC-SM-840 on our fab drawings but this provides no limits or guidelines on thickness. I do not want to cause an unr
Electronics Forum | Tue Sep 22 12:58:18 EDT 1998 | Chyrs
| How can I solve the small solder ball in the N2 W/S ? | The Oxygen level is 10000~20000ppm & no-clean flux. Yuen, Sorry I an't got an answer, just more questions. 1-2% O2 in your wave solder - are you running membrane generated nitrogen? I don't
Electronics Forum | Wed Nov 04 02:53:53 EST 1998 | Earl Moon
| Micheal, | | What does your profile look like for the wave? What profile does your flux say you need? My guess is it is not your profile, our testing with solder balls found that the mask on the boards was the largest contributor to solder balls
Electronics Forum | Fri May 02 09:37:23 EDT 2003 | Jerry Magera
Via in pad is the most efficient use of space. Blind via seems to be blamed for this. Cross-sections (send me some) will probably show a void still existing in the via or spherical voids aligned near the component pad side. One can estimate the vo
Electronics Forum | Sat Feb 16 07:21:17 EST 2019 | SMTA-Joe
I am experiencing a "tarnishing" issue on PWB traces that may be causing problems with component reflow. The PWB traces are made to the following spec: SOLDER MASK OVER BARE COPPPER WITH SILVER IMMERSION PLATING PER IPC4553, PLATING TO BE 8-12 MIC
Electronics Forum | Mon Nov 02 22:57:02 EST 1998 | Kelly Gossman
Micheal, What does your profile look like for the wave? What profile does your flux say you need? My guess is it is not your profile, our testing with solder balls found that the mask on the boards was the largest contributor to solder balls. Wha
Electronics Forum | Wed Sep 18 22:53:24 EDT 2002 | davef
Please give us background on your situation, so that we can focus on the specifics, for instance: * This is a bare board problem, correct? Then, this contamination causes what the problems in your process? * What is the type [ie, FR4, CEM1, etc] of
Electronics Forum | Fri Jul 10 14:40:12 EDT 1998 | Bob Willis
Yes this can be a killer. Its caused by glues with a high water content or fast curing of glues. When you get solder going through the glue it is litterally sucked in during solder wave contact. If you have never seen it you would never believe it bu
Electronics Forum | Tue Sep 21 16:09:08 EDT 2004 | davef
Q1: What is "enough surface free energy"? A1: Look here for background: http://www.azom.com/details.asp?ArticleID=1575 Q2: How do I determine surface free energy? A2: We look at it a relative term. For instance, a semi matte finish on solder mask
Electronics Forum | Tue Sep 25 14:08:59 EDT 2001 | davef
Oooo, the solder on the pad and PGA ball is flowing during reflow down the via to the secondary side? Why didn�t you say so?? ;-) Why would you expect that gravity and capillary action wouldn�t force solder to flow down the solder plated via to the
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