I designed a PCB with STM32F411RE and a couple of sensors.
Before and after mounting components on the PCB, I checked the Vcc and GND pins for short circuit and I did not see any problem.
I am using SWD programming and I connected my ST-Link V2 to my board and successfully loaded the program.
Everything was normal for a few minutes. Approximately 3-5 minutes after, the MCU disconnected from the PC and then I checked the Vcc and GND pins and observed a short circuit.
Interestingly, as time goes the resistance between Vcc and GND pin increases by itself.
After that, I just mounted STM32F411RE, reset pin configuration and Vcap. I connected my board to PC and loaded the program successfully.
After a while the power pins shorted again. I just uploaded a simple LED blinking test program.
My board schematic and PCB images are below. Please help me to find my mistake.