Electronics Forum | Mon Jun 21 21:05:47 EDT 1999 | Dave F
| We have a need to add a trace to a large quantity of bare PB's. The trace goes from a 25 mil QFP pad to a via. The rework must be done before we process the board. The rework cannot interfere with the solder paste screening process. | | Does a
Electronics Forum | Sun Mar 07 17:53:39 EST 2004 | Ken
Increasing the metals loading may help. But may cause issues elsewhere. Unsure of your exact process....but may work. Is anyone dispensing solder paste onto BGA pads...how is voiding in comparison???
Electronics Forum | Tue Mar 09 17:52:05 EST 2004 | davef
Bryan: Comments are: * You're correct, solder paste formualtion is a major driver to voiding in BGA balls. * Voids are primarily process indicators. There is experimental evidence that voids retard crack propagation locally around the void on a temp
Electronics Forum | Mon Oct 05 16:05:40 EDT 2015 | cyber_wolf
Washing no-clean solder residue out from under BGA's might present a challenge.
Electronics Forum | Thu Jul 10 22:46:08 EDT 2008 | davef
We'd like to see pads on the board that closely resemble those on the interposer.
Electronics Forum | Tue May 04 14:27:32 EDT 2004 | michasm2
Both are acceptable methods. - Printing on the board may give your operators a better ability to catch insufficient solder due to poor release; however if done right, printing directly onto the BGA ball is much more efficient and eliminates any compo
Electronics Forum | Tue Mar 01 15:13:22 EST 2011 | felixgutierrez
Hi Everyone. I would like your input in regards to lead free solder paste lead free. Which one is the most reliable solder for BGA's and BTC's (QFN). I have used different type of solder and on some of them i get big voids on BTC's and other one i g
Electronics Forum | Wed Dec 22 07:20:21 EST 2010 | piter
HI I used both of solder leveling HASL and ENIG, HASL I can recommended for biger pitch is cheaper solder leveling than ENIG but problem with that solder leveling is during the reflow process HASL isn't flat and during reflow process component move
Electronics Forum | Wed Nov 19 16:35:27 EST 2003 | davef
We'd be incluned to dip the BGA ball in tacky flux, place the BGA on the PTH interposer, reflow that suka, and get on with things. [Take the people involved out to lunch with the money you save on not buying a stencil.] On damaging the glop top, we'
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