Electronics Forum | Thu Nov 05 13:38:43 EST 2009 | davef
Martin It might be possible to mount a deballed BGA as you mount a QFN. Thinking about doing it, it could be a lot more difficult than first thought. When you heat a BGA, it 'dances' on the board because of the different CTE of the materials involved
Electronics Forum | Wed Nov 16 21:35:07 EST 2022 | stephendo
" so I wander what can I do to save them?" The boards or management? Seriously I think this is more of a management issue than a technical issue. We can suggest what to do but if management does not accept that solution then it won't work. I'm not s
Electronics Forum | Fri Sep 15 16:37:49 EDT 2000 | Dave F
Sounds like someone aimin� fo tha big hurt, if ya axes me. Two spots to place your lawn darts are: 1 J Hwang in "Modern Solder Technology � " states (p.354) that " � extreme CTE mismatch between silicon IC (~2) and the PCB (~16), solder connections
Electronics Forum | Mon Jul 26 19:32:03 EDT 1999 | Steve Gregory
| Can anyone give me the virtues of SMT package castellations vs. no castellations with particular reference to the ruggedness and reliability of the solder joints? Any references or studies that you can point me to? Also, although I'm in favor of
Electronics Forum | Sun May 17 13:46:30 EDT 1998 | Steve Gregory
Hi All! I've been reading this conversation which prompted me to break out the IPC-SM-786A from the IPC manuals from our parent company in Maryland sent us (we're just starting up in California). It's the Procedures for Characterizing and Handling of
Electronics Forum | Wed Feb 23 21:24:42 EST 2000 | Dave F
Chris: Whatever way you decide to define your pads, use the same type on the component and the board. Non-solder mask defined pad advantages: � No point-of-stress concentration at edge mask and solder ball � No CTE mismatch at edge mask and solder
Electronics Forum | Fri Jul 28 14:34:13 EDT 2000 | Gary Simbulan
Belive it or not, these boards were run through a Centech batch mode Vapor Phase machine. Single stage top side IR preheat. Vapor temp 218 C. Solder paste is an SN62 RMA.The boards were FR4 8 layer w/ solder mask, fairly conventional as might be e
Electronics Forum | Wed Jul 12 21:32:59 EDT 2000 | Dave F
John: Several thoughts: 1 What on your wave machine are these bowed boards catching on? It has to be something on either wave. Are you getting hung-up on the chimney? That doesn't seem correct!!! 2 Why do you want to measure the defection of y
Electronics Forum | Wed Feb 23 21:24:42 EST 2000 | Dave F
Chris: Whatever way you decide to define your pads, use the same type on the component and the board. Non-solder mask defined pad advantages: � No point-of-stress concentration at edge mask and solder ball � No CTE mismatch at edge mask and solder
Electronics Forum | Wed Dec 29 15:42:34 EST 1999 | Mike Naddra
Justin, I would be currious as to your customers application, and if the temperature delta and rate are great enough to cause solder joint failures as a function of mismatched Tce then you may want to consider that even if you are able to identify
