| ??? 10/20/09 22:56 Read: times |
#169919 - re: bgas Responding to: ???'s previous message |
Richard Erlacher said:
The last five or six colleagues who've attempted to use BGA packaging for short-run (where they couldn't absorb several respins of the boards) products, have found that it requires, typically six reworks of the artwork PLUS x-ray inspection of each assembled board with the costly BGA's, and, at least with prototype houses here in the U.S, they get about a 1% yield, i.e. 10% of the finished PCB's will pass electrical test, and 10% of the assembled boards have successful attachment of the BGA's. Sounds like your colleagues really don't know what they are doing. SIX revisions of the PCB artwork? Don't they follow the design rules? What are they doing wrong, that requires so many spins of the board? Seriously -- I think every board I've done in the last ten years has had a BGA on it, and I've NEVER had to respin a board because of a BGA fsck-up. As for the proto houses, maybe they shouldn't use the cheapest possible. The assembly company we use has nowhere near a 1% yield! They wouldn't be in business if that was the case. -a |
