Electronics Forum | Thu Oct 14 11:28:38 EDT 1999 | Bryan
We recently started designing boards using 0402's. The geometry was built using IPC specs but our contract manufacturer is having a yield problem. Approx. 20% of the 0402's are tombstoning. He claims the pads should be closer together; .4 mm between
Electronics Forum | Thu Nov 02 17:15:34 EST 2000 | Erdem Bilaloglu
We are using semi-circular land pattern and 0.004" smaller appertures on screen. With stable rising slope (max:2.6degC/sec)we have not experienced any tombstonning so far.
Electronics Forum | Wed Jun 12 03:26:03 EDT 2002 | edahi
We are currently having gross tombstoning with 0402 capacitors. We are using HiPb Solder Paste mounted on Laminate substrates. We are assembling Flip Chip BGA's. Temp @ Reflow is around 230-240 C to meet the thermal requirements for both die bump
Electronics Forum | Tue Oct 31 20:42:56 EST 2000 | speedy-tech
Now we are face with tombstoning for component '0402',we have tried many ways,it seems no change,Below is our experient: 1,The thickness of stencil is 0.12mm,and the aperture is circle.the diameter is 0.55mm.The pads size is 0.5*0.6. 2 Ch
Electronics Forum | Thu Nov 02 22:19:32 EST 2000 | Dason C
For 0402 or less, it is prefer to start on the pad design but it doesn't help right now. Senju Metal say that they have develop one of the paste can reduce the tombstoning problem but I don't have chance to test it. Please try and post your finding
Electronics Forum | Wed Nov 01 14:42:17 EST 2000 | MRMAINT
We had some similar issues on one of our products.The oven profile is critical. We found that with a gradual soak ramp up it took care of about 80% of the tombstoning.The other thing that we found was pad design issues. Take a look at the sept. issu
Electronics Forum | Thu Oct 14 13:26:31 EDT 1999 | Brian W.
I would suggest comparing the profile your factory used and the one they are using. Run a profile on some of the 0402 parts. If the profile is not right, uneven heating will cause this to occur. It could also be the placement accuracy in combinati
Electronics Forum | Fri May 12 05:47:18 EDT 2000 | Wolfgang Busko
Just another thing to look at: Look in the archives of IPCs technet. There I found this interesting this interesting link http://www.plexus.com/In_The_News/Papers/papers.html and an interesting article (in PDF format) about "tombstoning of 0402's a
Electronics Forum | Wed Nov 01 07:54:40 EST 2000 | Wolfgang Busko
Have you tried the forum�s archive ( an abundant source for tombstoning related things ) and checked for the many things you found ? Immediate help just like snipping with your finger isn�t that easy. Best thing to help is take all the info you get f
Electronics Forum | Mon Nov 06 14:21:09 EST 2000 | Kevin
Masking thickness can also play a factor in tombstoning (or the Manhattan Effect). If the pad is 2 mils or more below the surface of the masking this can create a problem. Depending on the thickness of the solderpaste deposition, the solder height
