Peek inside the IRG4PF50WD IGBT 8-)

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Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>

Hi All,

I took a little hot fuming sulfuric acid (don't do this at home!!) to one 
of the IRG4PF50WD IGBTs I pulled out the other day.  They don't make it at 
all easy to get inside them!!:

Here you can see the IGBT(left) and the reverse diode:

http://drsstc.com/~terrell/pictures/one.jpg

The parts are indeed perfectly good.  The die surfaces are a little dirty 
from the acid etch (especially the diode), but the die themselves are in 
perfect condition.  The IGBT is almost all copper on top with an aluminum 
over coating for wire bonding.

The gate fingers are far fewer and far more spread out than I expected:

http://drsstc.com/~terrell/pictures/two.jpg

It does not take much to drive them ;-)

http://drsstc.com/~terrell/pictures/three.jpg

The larger wirebonds are 20mil (350mil long) and the gate bond is 5mil Al.

Not all that much to see on the surface of IGBTs, but there is what they 
look like.  They are very well made in general.  Seems like there might be 
a little voltage drop on the emitter bond at say 500 amps, but that's why 
we drive them at 30V ;-))

Cheers,

	Terry