TFBGA225 Footprint on Discovery/Nucleo - why the holes, etc?

rbtmkr42 · ‎2026-02-23

Is there any utility in the holes and silkscreen circles around the TFBGA225 on the NUCLEO-H7S3L8? It appears to be the same pattern on the Discovery board, suggesting it might be for BGA placement or maybe a heatsink.

Edited to put the image in-line for better visibility

Andrew Neil · ‎2026-02-23

See this thread - it's probably for a ZIF socket used internally by ST for (early?) development.

Perhaps @mƎALLEm can confirm?

PS:

As @waclawek.jan noticed in the other thread, it's in the BoM:

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.

mƎALLEm · ‎2026-02-23

Hello,

These indeed are holes for a TFBGA225 socket.

The boards with socket are available only for ST internal developement usage not available on the market.

The PCB is common for the developement and market versions.

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