This part is a kind of semiconductor called SKM300GB128D.

Function of this product has IGBT Modules.

Manufacturers : Semikron International

Image and pinout :

Some of the text within the PDF file :

SKM 300GB128D ... Absolute Maximum Ratings Symbol Conditions IGBT  % %56 8 /  )- . /  1-* . %56)$%    #** : 8 ; )* :  < 1)**  /  1-* . %>56)$%>    1*  :  ? /  1-* . %>56)$%>    1*  :  ? /  1-* . /  1-* .   )- .   4* . %>56 %> 6 /  1)- .   )- .   4* .   )- ."      ' Values 1)** 23* )#7** 9 )* 1* Units  & & &  = SEMITRANS® 3 SPT IGBT Module   Inverse Diode %> %>56   )- .   4* . %> 6 %> )#* 14* 7** 14** )#* 14* 7** 14** -**  7*???B 1-*  7*???B 1)&" 1  ? 7*** & & & & & & & & & . .  SKM 300GB128D SKM 300GAL128D Freewheeling Diode Features             Module %@56 A  /       [ ... ]

SKM300GB128D PDF Datasheet Download