Electronics Forum | Thu Feb 20 17:18:24 EST 2003 | davef
Give us infortmation, please. What is [are]: * Height board to board side of the interposer on the low side of uBGA * Height board to board side of the interposer on the high side of uBGA * Alloy of solder balls, no paste was used correct? * Type of
Electronics Forum | Wed Jan 03 12:33:37 EST 2001 | Terry Burnette
John, There is one process issue that occurs with the larger BGA packages which have coplanarity near the high end of the .2mm spec.. The defect is commonly referred to as "ball in cup" and "head in pillow". It is an open solder connection whereby th
Electronics Forum | Fri Mar 21 08:56:29 EST 2003 | russ
Is it possible that the flux you used, if applied in excess could have caused the balls to "blow out". I have seen this in the past and it was related to the type of flux we were using and the amount. Russ
Electronics Forum | Mon Mar 24 08:57:20 EST 2003 | russ
I don't know if I would call it a "blow hole". what I believe happens (I don't have a camera to watch spheres during the reflow process) is that when the flux starts heating up, expansion, bubbling, or something physically displaces the balls. We fo
Electronics Forum | Mon Nov 19 05:49:44 EST 2001 | Cheng
The BGA solder ball composition is 62/36/2 Sn/Pb/Ag, does any problem exist for the solder joint reliability? And what is the difference on SMTA process between this and the normal 63/37 ball?
Electronics Forum | Mon Nov 19 10:06:15 EST 2001 | davef
Git otta taun!!! I never have heard of an Sn62 BGA solder ball. Several thoughts on Sn62: * Look at http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=4603&#Message17953& * Search the fine SMTnet Archives on � Sn62 �
Electronics Forum | Mon Nov 15 14:24:17 EST 2004 | nrocco
Im looking for equipment that can attach solder balls between the size 15-25 mils to the leads of a land grid array. There is also the posibility of attaching balls before leads are inserted into the socket. This is a little differant than attaching
Electronics Forum | Thu Sep 12 10:45:29 EDT 2002 | pbarton
We have used a laser cut stencil 0.15mm (0.006") thick with 0.3mm (0.012") square apertures radiused in the corners 0.06mm (0.0025") to aid paste release. This approach with the (type 3) paste we use has proven successful on thousands of devices plac
Electronics Forum | Fri May 17 16:53:50 EDT 2002 | davef
I recall a couple of papers in the SMTA 'Knowledgebase' that used ball shearing and an element in a study that compared BGA [maybe uBGA] component fabrication methods, er sumpin.
Electronics Forum | Wed Aug 27 08:25:24 EDT 2008 | davef
We'd expect to see: * Solder starved connections at pads with large trace/pad areas. * Less reliable solder connections at pads that do not match the shape and size of the corresponding pads on the component.
