Electronics Forum | Wed Oct 04 16:19:54 EDT 2006 | russ
you may want to try a different MFGR of paste, this does help on many occasions. Russ
Electronics Forum | Wed Oct 04 16:47:25 EDT 2006 | russ
very minimal at very few locations. We do not Xray every board but sample them. I think you will find pretty good results here (not perfect) Russ
Electronics Forum | Wed Oct 04 16:54:24 EDT 2006 | cw
OK. Thanks!! Lastly, is it the nature of the chemistry that Sn/Pb solder mixed with Pb-free alloy will be getting voids? If so, what's the physic/chemistry behind it?
Electronics Forum | Thu Oct 05 07:58:05 EDT 2006 | realchunks
I have noticed certain BGAs void more than others. We place about 8 different brands of BGAs and only one brand voids like crazy and we have to adjust for it.
Electronics Forum | Thu Oct 05 16:06:33 EDT 2006 | cw
Thanks! What's your ramp rate?2 - 3C/sec? What's your time above 217C. What's your peak temp?
Electronics Forum | Fri Oct 06 08:24:01 EDT 2006 | inds
CW, make sure your customer is aware of the affect high temp might have on adjacent components on the board. I guess you must have already checked out the rated temperature of all the components on the board
Electronics Forum | Fri Oct 13 06:44:18 EDT 2006 | Matt Kehoe
Solid Solder Deposit may work www.sipad.com mk
Electronics Forum | Fri Oct 20 07:03:46 EDT 2006 | sliebl
I really appreciate the input, guys. Having only had the opportunity to run the Contact machines, I was not aware that many of the other machines use coordinates for locals. Now about those damn, mid-chip solder balls.... oh, that's another topic.
Electronics Forum | Thu Dec 07 14:23:30 EST 2006 | russ
I wuld say it is attachment method and post install force that is the problem not the size of the heatsink. we place heatsinks that are at least 5 times the size of BGA with no issue, they are attached with very precision torque drivers. Russ
Electronics Forum | Wed Mar 21 17:08:34 EDT 2007 | iit
The biggest problem with double printing is that if the squeegee pressure and speed are correct, the stencil apertures are already filled with paste. Printing again can force paste between the bottom of the stencil and the top of the board creating
