Electronics Forum | Mon May 24 13:33:46 EDT 1999 | Dave F
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
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 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 09:44:45 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 | 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 | Sun Feb 07 10:51:09 EST 2010 | davef
The ratio of aperture opening area to aperture wall area is a critical evaluation measure for the release of the printed solder paste. The stencil thickness has the biggest impact on area ratio.
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 | Thu Dec 10 09:06:47 EST 2009 | stepheniii
Just how cold do you store your paste? And what are your solder paste reps like? Here they fall over each other giving support for their paste. And have you seen the problem with flux separation or have you only heard about it?
Electronics Forum | Mon Dec 14 18:45:08 EST 2009 | gregoryyork
why not use a paste where it requires no refrigeration at all cheers Greg
Electronics Forum | Tue Dec 15 00:09:26 EST 2009 | isd_jwendell
Which paste are you referring to?
