Rather extreme punch-through! I was expecting a pic of a hole in the die.
looks like there was an arc that ate a hole from the source pin through the
TO3 case. Geez! Weird stuff happens when you have enough voltage and seed a
V-field with ions...
Oppie

"Phil Allison" wrote in message
...


Who said power mosfets don't suffer " punch- through" like BJTs do ?

Pics are of an Hitachi 2SK176

Nch lateral, 125 watt, 200 volt, 8amp.




....... Phil