Electronics Forum | fredericksr |
Thu Feb 16 12:42:03 EST 2006
Electronics Forum | Thu Feb 16 12:41:50 EST 2006 | fredericksr
Hey folks, I was interested in any information that you might have on tombstone reduction when using a lead free solder and profile. Thanks for any input that you may have! -Russ #x
Electronics Forum | Thu Sep 11 09:22:27 EDT 2003 | swagner
Is there any conceivable way this could cause a tombstoned device?
Electronics Forum | Thu Sep 11 16:50:18 EDT 2003 | davef
Sure it's conceivable that thin HASL can cause tombstoning. Harkening back to the ample discussion in the fine SMTnet Archives, tombstoning is caused by an imbalance in solder surface tension between the two pads of SMT component. The source of thi
Electronics Forum | Fri Feb 17 09:02:21 EST 2006 | russ
proper pad geometries, accurate placement, and good reflow profile. Are you having problems right now?
Electronics Forum | Fri Feb 17 11:01:47 EST 2006 | amol_kane
with lead-free solders, one would expect to find less instances of tombstoning. this is because SAC alloys are not eutectic and melt over a range of temp (usually 217-220 deg C) instead of at a single temperature. therefore the forces due to solder s
Electronics Forum | Tue Nov 29 14:57:45 EST 2011 | jlawson
Sorry on N2 and tombstone, many other aspects cause tombstones and n2 in itself does not cause tombstones. It can help make other bad variables tip over edge to cause tombstones more than with no N2. Get these right then N2 is not issue.
Electronics Forum | Tue Dec 13 17:41:04 EST 2011 | davef
A Study Of 0201’s And Tombstoning In Lead-Free Systems, Phase II Comparison Of Final Finishes And Solder Paste Formulations http://sheaengineering.com/Documents/APEX%2008%200201s%20and%20Tombstoning%20phase%202%20paper.pdf CONCLUSION The condition
Electronics Forum | Mon Sep 23 18:11:10 EDT 2002 | steveb
On an assembly reflowed in air saw the same thing: 0201's with a grainular solder joint, but 0402's and above with perfectly formed joints. Reflow profile all within acceptable tolerances. Reflowing in nitrogen solves this problem, but increases t
Electronics Forum | Tue Mar 01 10:55:07 EST 2005 | spot
A lot depends on the complexity of the board/process as well as the amount of placements. If the board has few placements and the parts are not smaller that 0805 then doing all the rework after completion is ok. The human eye can only pick out obvi