How are MCUs tested for temperature rating?

[MMicl.1]

Hi!

I was wondering if anyone has any insight into the temperature rating testing for the STM32 MCUs.

Particularly, how can ST establish if a MCU is rated for 85*C or 105*C and how are those differentiated in the manufacturing process?

Are MCUs which are rated for 105*C different than the ones rated only for 85*C or has there been a selection during production?

Thanks!

[Uwe Bonnes]

I do not think different wafer processing happens, so I expect a selection process.

[MMicl.1]

Thanks for the reply. I'm assuming it will be the same, just wondering how they can label it as STM32xxxxT6 or STM32xxxxT7 or STM32xxxxT3 based on temperature - very curious to find out.

[waclawek.jan]

This is a primarily user-driven forum. We are not likely to be able to correctly answer questions which are related to internal manufacturing/testing/packaging/whatever processes. And for various reasons (competition, trade secret, trade secrets of suppliers etc.) ST may not be willing to tell this publicly or even privately, either.

Try to ask ST directly.

JW