Just Ask Happy: Routing BGAs With High-Speed Diff Pairs

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We asked for you to send in your questions for Happy Holden, and you took us up on it! The questions you've posed run the gamut, covering technology, the worldwide fab market, and everything in between. Enjoy.

Q: What advice can you give for routing BGAs with high-speed diff pairs when the routing of these signals so often cuts off routing channels for other signals?

A: This can be a complex topic, as there are a lot of circumstances that require consideration. My advice is to download a great book written by Charles Pfeil when he was an engineering director at Mentor. BGA Breakouts and Routing: Effective Design Methods for Very Large BGAs can be downloaded from Mentor’s library, and print copies are available for purchase from Amazon. Charles covers all of the options and boundary conditions that can come up, and he discusses the topic in the details that it requires.

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