Electronics Forum | Fri Nov 09 10:37:38 EST 2007 | devajj
We have started using QFN packages in large volume and are having problems with no-solders. We are using 6mil stencil with 1x1 paste print to pad. These also have thermal pads with thru vias that we reduce the stencil aperture by 1/4. Board also ha
Electronics Forum | Thu Nov 15 10:33:35 EST 2007 | paulallan
Does any one know of a supplier high temperature PCB ink that can safely used between pads on an SMT connector. The product ideally should be screened on and have resistant to short exposure to heat from a selective lazer. Must be non-conductive and
Electronics Forum | Wed Dec 05 02:01:51 EST 2007 | lococost
We've done some tests on this and got good results. Of course it can be dependant on the paste properties (thinking of slump in particular), and you need to get the heat under the connector which can be more critcal than in a leaded evironement, but
Electronics Forum | Tue Jan 15 13:16:25 EST 2008 | ck_the_flip
Yes, the previous "non-balling" flux was alcohol based, but very weak activity. We found it was worth the switch to water-based, to get prettier solder joints - but...at the expense of having to "brush off" solder balls on a couple of assemblies wit
Electronics Forum | Tue Jan 08 17:46:38 EST 2008 | swag
If the phone jacks have two conductors in them, I would wire them to standard SMEMA connectors so that the upstream side goes to the middle two SMEMA pins and downstream goes to the outermost two pins. If there are 4 conductors in the phone jacks, y
Electronics Forum | Sat Feb 02 22:50:04 EST 2008 | mika
Hi, I really don't understand your customers (or yours for that matter) problem with the shield - shorting? Please explain in more detail. Placing a tape seems to me to be the worst thing you can do, in terms of life-time. In what type of applicatio
Electronics Forum | Fri Feb 01 11:02:51 EST 2008 | flipit
You could also try Wenesco and Air Vac. I have experience on the Air Vac PCBRM10 and PCBRM12. They work great. You have to make sure your nozzle or flow well is designed correctly. For 50 mil pitch and greater, they work well. If you have to rem
Electronics Forum | Fri Apr 18 15:38:22 EDT 2008 | ck_the_flip
Do you have a picture? SMTNet HAS the technology now to post pictures. "Disturbed" to the typical Q.E. usually means grainy or dull, or a wrinkly solder appearance. All of this has to do with the "grain structure" of the solder joint. Here's a p
Electronics Forum | Thu Sep 11 10:51:56 EDT 2008 | slthomas
ISSG, I didn't see you mention anything with respect to profiling. Should we assume that you've already ruled out any thermal issues? Based on the proximity of your problems to a big honkin' connector that's where I'd have looked first. But then a
Electronics Forum | Wed Oct 08 00:58:19 EDT 2008 | darby
Short answer is yep, if you are centering on the nubs and not the leads. Depending on the registartion between nubs and leads you may then have misplacement. Holes as fids will usually let you down at some stage due to vision issues. Blunt drills bla
