Ladies and Gentlemen,
We are having a major problem with an assembly
house with registering
the solder paste to surface mount features prior
to pick and place. They
are claiming that the boards are
growing/shrinking some 15-20 mils.
We have done extensive measuring on unpopulated
boards in-house
and cannot see more than 3-5 mils
misregistration. The panel size
is approximately 14.00 x 16.00 inches, 20-24 mil
pitch, and 15 BGA's
throughout the panel. Overall thickness .080. Is
it possible that the mesh
screen that they are using can expand/contract
over time? has anyone
heard of this experienced this situation before.
Any information would be
greatly appreciated.
Thanks
Tony Steinke
AIT-Atlanta