Electronics Forum | Thu Aug 01 08:31:51 EDT 2002 | patrickbruneel
Christopher, It looks like you might be close to the solution for your problem because you mentioned that you can make the solderballing worse with lowering the preheat temp. This means that the preheating has a significant impact. I would suggest t
Electronics Forum | Fri Apr 23 11:42:30 EDT 2004 | patrickbruneel
Thanks for the answer. what i believe happent is that the manufacturer of the paste reduced the tackiness of the paste to eliminate the squeegee sticking problem, and now with the reduced tack its a lot easier for the powder particles to break off du
Electronics Forum | Wed Apr 28 15:08:10 EDT 2004 | russ
This could be a long shot but here goes. I have found that if flux is applied in excess that it will actually "move the solderballs" during reflow. I have actually seen where the balls are completely outside the package and oviously there are short
Electronics Forum | Thu Jun 24 11:54:36 EDT 2004 | rickw
many solder-ball issues can be resolved by reducing the aperture size, usually 10 to 15% reduction will work. If the aperture size is the same as the pad size paste tends to be squished out under the part, paste off pad under the part will liquify a
Electronics Forum | Sat Feb 19 09:11:36 EST 2005 | davef
Currently, we see lead-free solderballs on BGA. The issue for us is determining the reliability of these components when using leaded solder. Most solder materials manufacturers supply lead-free solder balls. Check with your current solder paste s
Electronics Forum | Wed Apr 13 18:28:21 EDT 2005 | RT
We have a situation where our customer returned a device (BGA) with a missing solder ball. The process is Copper-Nickel-Gold-Solderball. EDX revealed that no trace of gold nor solder material (lead-free balls). Could poor Au plating/adhesion cause
Electronics Forum | Wed Apr 27 15:14:12 EDT 2005 | andymackie
The viscosity decrease on warming is one of the main reasons, but you also don't want to get moisture condensing on the surface of the paste. Activators in the paste (that are used to eliminate solderballs and enhance solderability on reflow) become
Electronics Forum | Mon Jul 18 10:55:26 EDT 2005 | Sylvain
I have a SO-8 mosfet part from Vishay SI7846DP-T1. Am having a lot of solder ball that coming underneath the part. Am currently using a 5 mils with a window design for my stencil. Those anyone have experience or have any suggestion for an aperture th
Electronics Forum | Thu Jul 21 09:43:10 EDT 2005 | davef
We agree with Russ. The solderballs are probably the result of printing too much paste on the board. In designing your 5 thou thick stencil: * Aperatures for the pads should be identical to a IPC-7351 - SO8 [or worst case http://www.vishay.com/docs
Electronics Forum | Mon Oct 30 09:24:21 EST 2006 | ronalds
I have some problems in sufficient preheating the pcb's. They splatter on the mainwave, causing solderballing. Less flux causes problems with the fill of the through- holes. We use a Delta Wave with 3 preheat zones, the first two are calrods the thi
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