Graham Sutherland / Polynomial on Nostr: hot take: BGA packages should not have mixed pitch. ST's TFBGA361 package for the ...
hot take: BGA packages should not have mixed pitch.
ST's TFBGA361 package for the STM32MP1 uses 0.5mm pitch for the majority of pins, except the center power region which uses 0.65mm pitch.
I get that part of the idea is to allow bigger vias for lower PDN impedance, but they're fitting 77 pins (9x9 with corners removed) into a 15x15 space and could easily space them at the 0.5mm pitch with VSS separating the VDD pins from the IO pins.
ST's TFBGA361 package for the STM32MP1 uses 0.5mm pitch for the majority of pins, except the center power region which uses 0.65mm pitch.
I get that part of the idea is to allow bigger vias for lower PDN impedance, but they're fitting 77 pins (9x9 with corners removed) into a 15x15 space and could easily space them at the 0.5mm pitch with VSS separating the VDD pins from the IO pins.