we have some temperature problems with STM32F429 (BGA) controller boards. If the temp. exceeds by some boards 40°C, and other boards at 60°C the internal voltage regulator shut down, measured at VCap1 & 2. Every temperature between 35°C and 80°C is possible. The shutdown temperature does not change, it remains fixed. Most controller don't have any problems, they functure with temp. over 80°C.
Any idea? What can I do?