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't work then check your Gerber data for X or Y centroid data issues. 3) Your IR solder bath system may have a transport problem, (ie, jerkiness, etc), thereby causing some shifting in the parts during a critical stage in the transport. 4) IR by its nature has some color emissivity problem and terefore is color sensitive. (the dark parts may be reaching reflow temperature first and the light colored parts are reaching reflow last). Hope these might give you an idea for the eventual resolution. Good luck JON | WE have a problem of tomb stoning in our smd assemblies during curing process of the boards in our Infra Red Soldering bath. Would you like to give us solution how to resove this proble? | Thankyou | Regards
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