Electronics Forum | Thu May 26 08:52:42 EDT 2011 | davef
Phil Zarrow wrote a useful paper that could help in evaluating paste. Here read it ... Evaluating Solder Paste � Not An Option Contributed by Phil Zarrow of ITM an Independent SMT consulting firm With soldering being the dominant source of assembly
Electronics Forum | Wed Aug 07 11:21:28 EDT 2019 | charliedci
The melting of the solder during reflow itself can center up or skew a component. This could be pad size differential, incorrect pad size, unequal solder deposition amounts, pad spacing in reference to component size just to name a few.
Electronics Forum | Thu Nov 02 09:45:00 EST 2000 | bierleinb
I would check trace-pad interactions as you may be robbing heat from one of the pads causing uneven heating during reflow. Also, measure paste deposits on trouble parts to see volume depsoted across the pads. You should easily be able to do 0402s w
Electronics Forum | Mon Nov 06 10:29:28 EST 2000 | Dean Stadem
All of the replies have merit. Here is another one. Because the cause of the tombstoning is wetting forces that are imbalanced, and one end wets faster or more readily than the other, the 0402 lifts up on that end easily because of its low mass. Incr
Electronics Forum | Fri Nov 03 11:08:29 EST 2000 | Phil
Hi there!!! Actually, all mentioned ideas were significantly related to the cause of tombstoning. But, based on what DL said, you have to check the placement of your 0402. Coz, based on experience, i evaluated the different variables for the root
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 | 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 | 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 | 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
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