Electronics Forum | Fri Jul 15 13:58:32 EDT 2005 | seaK
Our production is putting QFN40 and QFN56 package on board. With 80% opening on terminal, 40% on thermal pad, we found QFN56 100% forming toe fillet, but it does not work out the same to QFN40. We suspect it's because of the weight of component.....
Electronics Forum | Wed Jul 06 12:04:39 EDT 2005 | sarag
Jason, If you have any pictures of this phenomena that might be helpful for the forum to see in helping diagnose your problem, you can send them to me and I can post them on my website to view. My email is sg_foresite@residues.com Sara Gorcos Fores
Electronics Forum | Fri Jul 08 16:35:04 EDT 2005 | Jason Fullerton
"Whether or not you need a toe fillet depends on your application. We have high reliability products where we can't use a QFN over a certain size, regardless of toe fillet. We have other applications where we meet the thermal cycle requirements for a
Electronics Forum | Mon Feb 06 17:19:59 EST 2017 | davef
Evtimov: IDEALS Project was one of the first to talk about componebt and board damage caused by LF soldering temperatures. There's lots of more current stuff on the web. Here's some that may help: * Assessment of Long-term Reliability in Lead-free As
Electronics Forum | Wed Jul 06 14:36:05 EDT 2005 | Bob R.
The only way we can consistently get a toe fillet is to use a paste with an extremely active flux. We allow that paste on certain products, but discourage it's use because it's on the hairy edge of not meeting our lower limit in surface insulation r
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 Feb 20 13:01:26 EST 2004 | Jay
First, it depends on the alloy composition of the solder. As you might know, eutectic Sn/Pb solder has the lowest melting point among available conventional solder systems. (except those based on Sn-In and Sn-Bi systems.) For example, 63Sn/37Pb - 183
Electronics Forum | Wed Sep 02 06:50:55 EDT 1998 | Masdi Muhammad
Hi, We are having problem with yield loss due to electrical fail. Further investigation shows that the failure is due to solder bridging under BGA. Has been there any study or experience on how this could occur and what we can do to prevent it. Than
Electronics Forum | Fri Oct 26 11:09:13 EDT 2007 | hussman
Even a proper solder joint will fail if the rite stresses are applied to it. Sounds like you have an over heating issues, not a solder issue.
Electronics Forum | Fri May 07 17:02:01 EDT 1999 | Earl Moon
| On 1.27mm (0.050 inches) Standard Ball Grid Array's. | The ball size diameter starts at approximately 0.025 inches. | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? | | This
