Electronics Forum | Thu Apr 11 20:35:22 EDT 2002 | davef
Messy. Messy. Messy. Consider gluing these components, until you control your process. It is unclear to us that a single factor drives these defects, but multiple factors that need to be tuned to work well together. PAD DIMENSIONS * Some SM-782 pa
Electronics Forum | Thu Apr 11 16:37:16 EDT 2002 | pteerink
Profile would be the first place I look. Check your rise and fall rates for temp. Should be no more than 2 deg/sec for rise and 4-6 deg/sec for cooling. Phil
Electronics Forum | Thu Apr 11 14:31:15 EDT 2002 | aaelect
We're having some problems with 0402's tombstoning. On a board with about 300 parts we're getting about 12 to 20 tombstones per board. The caps seem to do it more often than the res. The pads appear to be in accordance with IPC SM 782 amendment 1, S
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 | 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 | Wed Apr 12 09:20:57 EDT 2000 | C.Long
anyone any ideas how to minimise my DPM as regards tombstoning..i have checked oven profile..appeture size on my stencils..placement machine etc and still problems.???????????
Electronics Forum | Fri Oct 29 07:10:40 EDT 2010 | scottp
I agree with DucHoang. If your board and reflow profile have not changed then I would suspect incoming parts. We've seen tombstones when a chip supplier had plating problems.
Electronics Forum | Thu Oct 28 08:28:33 EDT 2010 | d0min0
Hi, previous topics found closed so I couldn't continue on them, but wanted to ask maybe something that we don't already know paste shape and placement ok, reflow 12 zones profile looks ok (same since 2 yrs), component placement ok, one reference i
Electronics Forum | Mon Apr 09 20:55:46 EDT 2012 | action_101
I forgot to add that we are using a 3 mil stencil. It seems like to me that may be there isn't enough flux left when we reach liquidous?? About half of the solder spheres do melt and wet on each pad, but the top half of each solder joint is just the
Electronics Forum | Thu Mar 12 06:37:48 EDT 2009 | gregoryyork
I agree you are too cold for the profile get it up to 230C and possibly allow it to dwell a little longer in preheat as opposed to pushing up the reflow zone only. Sn90/Pb10 melts at 220C so 2C hotter than your profile so you are reliant on it alloyi
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