Question

Why is semiconductor damaged by strong current?

Answer 1

Because heavy current causes the semiconductor to heat up, since there there is more power passing through, and a portion of that energy is converted into heat. Then, once the temperature level goes up a little, the semiconductor passes more current through, which causes causes the temperature to go up even more. More current causes higher temperature, which causes more current. This cycle repeats itself in what is called thermal runaway. Ultimately, the semiconductor is destroyed.