Hello,
I’m using a 10 µF, 20 V tantalum capacitor as a decoupling capacitor across a 5 V supply. When I power the circuit, the capacitor burns out.

At first, I assumed the tantalum capacitor was defective and replaced it, but the new one burned out as well when the circuit was powered.

I then replaced the tantalum capacitor with a 10 µF, 63 V electrolytic capacitor. This time, the capacitor did not fail after powering the circuit.

I do not understand why the tantalum capacitor burns up?