[cellularmitosis]

"Either 45Watts to one or 90watts to both appears to pop the plastic off the silicon with out any apparent damage to the chip"

Oooh, found my project for the weekend!

"Now it is no longer possible to do this since the packaging department had redesigned the package"

aww shucks

[dfox]

The package redesign remark is only directly relevant to NatSemi TO220-5 parts. There are various other TO220 packaged ICs (and discrete devices) made by other manufacturers which have exactly the described failure behavior.

[weinzierl]

You can pop LED's. Maybe not quite the same but also not as expensive.

[linker3000]

Careful - many years ago one just missed my eye and cut my brow (unplanned overload; no dicking around involved)

[setquk]

International Rectifier / Vishay IRF510’s do this. I know from experience building RF amps with them.

Wear safety glasses!