erbauer18v drill, what is the semiconductorscrewed on the switch?

The drill has a semiconductor screwed onto the swich, in my case it has split. i managed to read on the chip the following info "p7580404z" manufacturer is "st". i cannot trace the chip as a Thyristor, or similar switching chip or even a cmos throttle of some sort.
Can anyone put me out of my misery and tell me or supply such a chip?
The drill is an erbauer 18volt model RO7W14 OR ERB82180.