Electronics Forum | Wed Dec 08 10:10:41 EST 1999 | John Thorup
Hi Dave I think you just provided the key to understanding the problem. By your description you are talking about a CBGA (ceramic). These typically have balls composed of 10/90 Sn/Pb which melts at a higher temperature than the 62/36/2 Sn/Pb/Ag (or
Electronics Forum | Tue Sep 14 02:46:17 EDT 2010 | grahamcooper22
Hi Gani, Looking at the pictures in the report it looks as if there is a thin coating of solder on the pcb pad....but it looks like the BGA sphere was barely in contact with the pad. This could be caused by insufficient solder paste on this pad...may
Electronics Forum | Tue Sep 14 14:22:11 EDT 2010 | grahamcooper22
If the HASL was poor quality and very thin you would find this defect....but you would expect to see it on more pads also. Also, you'd expect to see your solder from your solder paste either dewetted on the pad or reflowed onto the BGA sphere making
Electronics Forum | Wed Feb 18 12:42:43 EST 2004 | babe
OK, if the sphere of the ball and the paste on the pad are both eutectic, 63/37 then the paste will reflow first causing a drop of the component, after which the spheres will reflow causing a double drop and a good intermettalic. You can see this by
Electronics Forum | Fri Aug 08 07:52:26 EDT 2003 | pteerink
We have seen this for quite a while too ( chip components and IC's with lead free plating on the terminations ) and we did just what Dave said, crank up the heat. Also switched to newer formulations of solder paste, that are "more active" and have gi
Electronics Forum | Thu Mar 02 21:51:46 EST 2000 | Dave F
Robert: Consider requesting samples of different sized solder balls from a variety of suppliers, solder them to dummy boards, and compare the size of reflowed balls to your spec. Then you could buy based on results. My2� Dave F
Electronics Forum | Thu Mar 02 21:51:46 EST 2000 | Dave F
Robert: Consider requesting samples of different sized solder balls from a variety of suppliers, solder them to dummy boards, and compare the size of reflowed balls to your spec. Then you could buy based on results. My2� Dave F
Electronics Forum | Fri Jan 31 05:18:10 EST 2003 | reg
We have a customer who is going to be using the new Snapshot process. Has anyone used this process all ready. Who did you use to make the tooling etc. Was there any problems that arose during this process. The process involves screening balls into s
Electronics Forum | Thu Sep 07 11:02:29 EDT 2000 | Travis Slaughter
Maybe its not splatter, in my experience a sloppy operator can get paste on contacts and just one sphere can rune them and can look like splatter.
Electronics Forum | Thu Sep 19 11:02:17 EDT 2013 | hegemon
If there is only a single lead free BGA on the BOM, I would suggest a "hybrid" profile. Use regular solderpaste (SN63/pb37) and peak your temperature at around 225C. Allow a bit longer TAL to let the two solders co-mingle at the BGA joints. You are
