Electronics Forum | Mon Jun 11 21:27:43 EDT 2001 | procon
Way to go CPI! This is a classic example of design. Many people experience this when the have an 0402 close to a QFP or other large components. The pad closest to the larger component will become liquidous later than the pad farthest. Hence, a new t
Electronics Forum | Sat Mar 15 00:52:18 EST 2003 | Grant
Hi, We had tomb-stoning on a product, and it was quite severe. We eliminated it by reducing the amount of solder paste on the small passible component pads. We used a 5 thou stencil, with 20% reduction, and it eliminated the problem. Regards, Gra
Electronics Forum | Wed Jun 11 14:12:42 EDT 2003 | stefwitt
the registration fee became the second largest issue after 0402 tomb stoning. http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=5640Message22248
Electronics Forum | Fri Nov 07 11:32:36 EST 2003 | Gabriele
we experimented round pad for 0402, it improves chip self alignment and reduce tomb stone effects. On 0603, half round shape also gave guud results. G
Electronics Forum | Tue Jan 17 17:29:42 EST 2006 | pjc
Here's a page on tombstoning: http://www.tkb-4u.com/defects/reflow/tombstoning/tombstoning.php Be sure to see this on the bottom of the page: For more info about this item look at the Articles / Newsletter: (Causes and Cures of Tombstoning Chip C
Electronics Forum | Tue Jan 17 17:41:14 EST 2006 | pms
GEB, The parts that are tombstoning have all ready been through reflow once with no problems, so I assume the paste and the positioning was correct the first time, since they did not tombstone through the first reflow. This is very strange.
Electronics Forum | Wed Jan 18 02:00:36 EST 2006 | pavel_murtishev
Good morning, This isn�t very strange. Bottom side components are prone to tombstoning more than topside ones. Try to reduce oven�s bottom heaters temperature slightly to prevent solder paste melting on bottom side. This can help. BR, Pavel
Electronics Forum | Wed Jan 18 11:26:16 EST 2006 | chunks
Hi Bjorn, Yes that can also add to tombstoning, but if maticulate your stencil to a high sanalot, you shouldn't see any tombstoing.
Electronics Forum | Thu Apr 20 21:45:10 EDT 2000 | Dave F
Wister: Oooo, I understand now what you mean by "an open." Sorry, I was (am) a bit dense. Your hypothesis is reasonable. On the other hand, have you looked at the traditional causes of tomb stoning also? For a defect to be a "tomb stone," it doe
Electronics Forum | Tue Dec 30 20:31:11 EST 1997 | Jon
I suggest that you look at a few things: 1) The SMD pads may be too small for the part. Try to conform with the IPC standards in pad design. 2) The parts may be misplaced during the placement process. Tweek the placement program and if that doesn'