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? o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o Peter Swanson, Oxfordshire, England Dynamix Technology Ltd [log in to unmask] CompuServe: 100120,3641 If you tied buttered toast to the back of a cat and dropped it from a height, what would happen? o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o-o