Electronics Forum | Wed Aug 07 13:36:48 EDT 2013 | rway
You should be able to distinguish between solder and absence of solder. Have you tested it without solder?
Electronics Forum | Tue Jul 19 09:45:51 EDT 2005 | cyber_wolf
I have seen this problem on Mydata machines before. I am very sure that your missing paste is being caused by the placement machine. Check these things : 1. There is a small white check valve on the pressure side of the vacuum pump. Make sure it is
Electronics Forum | Tue Aug 09 13:44:48 EDT 2005 | mtd
The solder on the rest of the board looks good. There are no large components around these parts. We check the profile using a KIC and it met the recommendations of the solder paste manufacturer. I have not did a dip test of the board or components.
Electronics Forum | Fri May 27 07:09:23 EDT 2011 | mbnetto
Thanks everybody for the answers. I already chose 3 differents solder paste brands. And, how many boards it's necessary to perform these evaluation tests to have a reliable result? 20, 50, 100 boards?? Thanks.
Electronics Forum | Sat Oct 07 11:14:39 EDT 2000 | Aaron
1. It is hard to tell, but your PCB vendor should test the PCB. 2. I think the important thing is the width of the apertures. You should have it laser-cut, and control the width no more than 90% of half pitch. Good luck.
Electronics Forum | Tue Jul 19 12:10:04 EDT 2005 | CLampron
Sr. tech, The mount tool test position is what I am refering to. The function of this is to determine the placement plane of the board. The mount plane will change if the board is thicker so thickness is relavent. regards Chris
Electronics Forum | Mon Dec 16 19:05:57 EST 2002 | davidduke
Steve , I agree with all the responses you have received. Randy Villeneuve is absolutly correct in all of his assesments and I would consider him an expert with the process , Gris is correct about adding a "heat sink" to the process complicating pr
Electronics Forum | Thu Aug 28 16:13:06 EDT 2003 | Dan Gosselin
Thanks everyone for your help. I have since found a good article I am downloading of of the SMTA website. Dan Title : EFFECT OF SURFACE TENSION OF SOLDER ON UNDERSIDE DEVICE SUPPORT DURING REFLOW OF A PCBA Author : Mulugeta Abtew Author Company
Electronics Forum | Sat Sep 18 12:10:19 EDT 2004 | Steve Gregory
I have a question about solder masking via's in a BGA pattern, and want to see if I'm thinking correctly about this. This problem is kind of along the same line as Carol's problem earlier. I think it's a bad idea to leave the via's free from solder
Electronics Forum | Fri Jun 30 20:39:52 EDT 2006 | johnwnz
Grant, Haven't doen any work with the SN100C paste, the problem I guess is yoru subject to the suppliers flux base so if that is poor then the alloy may not perform as well as it could. We've found Avantec to be pretty good at SMT but have got SN100C
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