Electronics Forum | Tue Jan 06 19:53:32 EST 2004 | jj
Hi, Any idea what's the possible causes of cold solder after drop test? Thanks JJ
Electronics Forum | Fri May 17 16:37:28 EDT 2002 | Tom Druan
I was wondering if anyone could direct me towards documentation on shear test methods/apparatus to test the bond integrity of a solder ball to its substrate. Thanks.
Electronics Forum | Wed Jan 07 07:16:25 EST 2004 | davef
Cold solder prior to properly performing a well designed drop test. Actually, "cold solder" means different things to different people. Two dull solder connection conditions are: * "Disturbed" solder joint: a solder joint that has an "angular face
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 | Fri Aug 22 00:25:20 EDT 2003 | mantis
Kenny, Out of curisoty why do you need to paste the vias.Is it due to contact reliability at test.Can these vias not be soldered during wave process (if any).Can the Style of probe used in the ICT test fixture not be changed to accomodate these unsol
Electronics Forum | Fri Aug 22 09:41:49 EDT 2003 | davef
Mantis: Kenny reflows paste on [wave solders] all via, not just the test via, to plug the via and provide for a pressure seal between the board and the test fixture. Beyond that, since solder is softer than copper [and fills the hole better], solde
Electronics Forum | Tue Aug 26 21:12:24 EDT 2003 | iman
depends if your water wash process is manual or automation? important is the water residue inside the via holes is adequately blown out. As long as the water-flux residue is out, testing down the line should not be a issue, at least from theory and o
Electronics Forum | Thu Aug 21 23:35:20 EDT 2003 | kennyg
For ICT purposes I may need to print solder paste on 0.015" test vias. No-clean is not an option for this assembly and OA seems the only choice. Can flux be safely removed from inside the via from the other side during a standard water wash process
Electronics Forum | Fri Aug 22 09:44:45 EDT 2003 | davef
Kenny: Since you need to use water soluable flux and can't use no-clean, consider asking your board fabricator to plug the via.
Electronics Forum | Sun Sep 12 08:30:29 EDT 2004 | davef
Well, another alternative is to use a water washable flux. If you insist on staying with a NC flux, use one that is probable. We prefer to probe solder, rather than copper.
