You use a round pad with 0.35mm diameter, but the datasheet reports to follow this appnote https://www.maximintegrated.com/en/design/technical-documents/app-notes/1/1891.html for land pattern.
This document recommends to use a pad of 0.25mm diameter for devices with 0.5mm pitch.
So why do you use 0.35mm instead of the recommended 0.25mm?
This will my first BGA device on a PCB, so i'm asking to learn.
thanks
Added 4 years ago.
Hello Aureliuss!
Thanks for sharing your feedback. The BGA for the MAX30001 was creating following IPC-7351B standard.
Based on IPC, the larger ball diameter option has been allowed to accommodate packages using rigid interposer structures. JEDEC Standard - JEP95 table Ball Diameter Variations for FBGA states that for 0.50 mm ball pitch FBGAs, the minimum diameter size is 0.25mm and the maximum is 0.35mm and we use the ‘maximum’ land pattern condition as IPC prefers. IPC uses the maximum land variation diameter. Would you prefer us to follow the ‘minimum’ land pattern geometry variation?
Hope that helps!
Elizabeth
Answered 4 years ago.
By the way, I have generated the schematic for you to use as well!
Thanks,
Elizabeth
Answered 4 years ago.