Hello all,

We are trying to remove and replace two ORCA 432 pin BGA's on a big 14-layer
board. We are getting alot of shorts after the rework(I'm x-ray inspecting).
At first we tried solder pasting the pads with a mini stencil, but the
amount of bridging we got caused me to try just fluxing the pads and letting
the solder balls collapse, but we still got a lot of shorts. I am also
noticing a lot of board warpage  during the rework heat cycle and it also
appears that during reflow if I watch the component, the corners of the BGA
collapse very early and the component almost appears to be bowing. Most of
the shorts we are getting are in the corners where this last observation
occurs making me think it is causing the shorts. Any suggestions on how to
eliminate this problem?

Thanks,

Tim Stammely
Manufacturing/Process Engineer
MSI
Manassas, VA

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