64-WLCSP footprint — board-level considerations
The 64-WLCSP package measures 3.35 mm x 3.59 mm, one of the smallest footprints in the STM32F0 lineup. That buys real estate on a dense PCB but demands a controlled assembly process — the WLCSP has no molded body to absorb solder-joint stress, so board-level reliability depends on stencil design, reflow profile, and underfill for applications with thermal cycling.
The base product number STM32F098 covers a range of density and package options, so if a future board revision needs a different Flash/RAM or package, the migration stays within the same family without a core-architecture change.