Electronics Forum | Wed Dec 13 06:08:48 EST 2000 | jackofalltrades
We have seen this type of problem. After eliminating possibility after possibility we corrected the problem by throwing out the glue and starting fresh. It was not expired, just bad for whatever reason, we could not asertain what went wrong with it.
Electronics Forum | Fri Dec 08 11:08:03 EST 2000 | Antonio
Ok fellas, tell me how you'd fix this! I'm having melf connectors that are tombstoning in the wave, NOT the reflow, the wave. I've never seen this before. All other parameters are the same...solder, preheats, placements, the board, building humidi
Electronics Forum | Mon Dec 11 20:56:29 EST 2000 | Dave F
I'm with ya John. I'm afraid I'm in brain lock on picturing the situation, mostly because of my bias against waving second side MELF. I know people do it, but we've never had good luck. It would be good if we could have a clear process flow to hel
Electronics Forum | Tue Dec 12 08:44:27 EST 2000 | Wolfgang Busko
Another theory just developed in this very moment is that the glue did for what reason ever become "liquid" to a certain degree allowing gravity to do what gravity normally does but only to a certain point where this bubble-gum-like state stopped ( w
Electronics Forum | Tue Dec 12 08:53:40 EST 2000 | Wolfgang Busko
I�m with ya both. I�m wondering why the hell those buggers didn�t just drop and started a new career mingling with the dross in the pot. If only a few for statistical reason and to confuse us all just showed this strange behavior and the majority de
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 | 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 Nov 04 04:27:46 EDT 2010 | d0min0
thanks for all the feedback... we also checked, just in case : - bake the components (no visible improvement) - bake the pcb (50% less tombstone components) - finally we changed LF paste to completely different manufacturer - and booom 0 (zero) tombs
