Query Regarding Recommended PCB Pad Size for STM32MP157FAC1 (TFBGA361)

[PS_115]

Hello,

We are designing a custom board based on the STM32MP157FAC1 device, which is available in the TFBGA361 package.

In the STM32MP157F datasheet (Page 251), the recommended PCB design rules for the TFBGA361 package are provided. Snapshot is attached for your kind reference. However, we are unable to determine the recommended PCB pad size from the information given.

Could you please clarify whether the recommended pad size corresponds to Dpad or Dsm, or advise which parameter should be used while designing the PCB footprint?

Regards,

Prashant

 

 

[PatrickF]

Hi ​@PS_115 

you could use UltraLibrarian or SamacSys to generate the libraries for your favorite CAD tool.
https://www.st.com/en/microcontrollers-microprocessors/stm32mp157f.html#cad-resources

Datasheet values are only recommendation and usually all those dimensions should be tailored to your system constrains (NSMD or SMD, copper thickness, reflow process, etc...) and habits. You should also check with your PCB manufacturer and your assembly house what they recommend too.
Most people follow IPC-7351 recommendations, but I think there is no golden value, just an acceptable range.

 

Regards.