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 | Fri Apr 12 15:10:00 EDT 2002 | jsherrow
IMHO it's caused by three things: 1) placement 2) placement 3) placement
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 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 | Wed Apr 12 21:33:27 EDT 2000 | Micah Newcomb
Billy and Chris have a good point, pad size and geometry will affect proper aperture size and geometry and could result in tombstoning. Also I have seen chips which require special pastes but I have never found this to be the cause of tombstoning, in
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 | Thu Oct 28 09:52:39 EDT 2010 | dyoungquist
Try rotating your board 90 degrees when running it through your oven. Will probably solve the tombstoning issue on that cap but might cause tombstoning elsewhere.
Electronics Forum | Thu Oct 28 10:06:12 EDT 2010 | d0min0
We saw this idea in older posts, but - we don't want tombstone elsewhere :) - rotating the boards before oven is complicated, so it could give more problems than the tombstoneing :) the issue is not 100%, it is 10 to 50 boards with component up per 3
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
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