Hello:

I find that the tightest tolerance suggested in IPC-D-275 for bow and twist 
is 0.5% for multilayer boards.  Our fabricator had great success to develop 
a process and  produced five parts less than 0.25%.  Generally, our cards 
are 6 by 9, and .063 to .093 thick.

Do any assemblers find it necessary to specify this requirement less that 
.5% to automate the pick-N-place process?

Thank you in advance,
and waiting for a Minnesota summer (I may have to wait until next year),

Kevin Thorson
Lockheed Martin