One of our customers has a query:

"I am adopting IPC standards in our company, especially in regard to pcb 
flatness.

IPC 610 (para 8.3) gives 0.75% for populated surface mount boards.

IPC 600 (para 10.1) requires on average 1.5% with only 6 instances (T4 sized 
boards) where flatness is better than 0.75% and this is for _non-populated_ 
boards.

I find this confusing - can you advise."

We note that IPC 600 says that flatness requirements stated may not meet 
surface mount requirements. What will the new revision of 600 say?

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               Peter Swanson, Oxfordshire, England
                     Dynamix Technology Ltd
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