This part is a kind of semiconductor called SKM400GB123D.

Function of this product has IGBT Modules.

Manufacturers : Semikron International

Image and pinout :

Some of the text within the PDF file :

SKM 400GB123D Absolute Maximum Ratings Symbol Conditions IGBT *5 &* &*: ;5 .= .   . 2 03 71 4* 2 /  .>5:+.& ? .  +* /  @ . 2 03 71 4* 2 /  2 /1 C  @C .= 2 /31 4* . 2 03 4*     # Values /011 811 991 $11 < 01 ' 81 @@@A /31 /03 0311 9B1 0$1 $11 0B11 Units  + +  4*  + + + SEMITRANSTM 3 IGBT Modules SKM 400GB123D Inverse diode &( &(: &( Characteristics Symbol Conditions IGBT ;5  &*5 *5 . *5 *5   ;5 2 *5 &* 2 /0 + ;5 2 1 *5 2 *5 .= 2 03 /03 4* .= 2 03 /03 4* ;5 2 /3  .= 2 03 /03 4* &*  2 911 + ;5 2 /3     #      ;5 2 1 *5 2 03  # 2 / !F . 2 03 4*     # min. 83 typ. 33 1/ /8 /$ 9$$ 3 0 [ ... ]

SKM400GB123D PDF Datasheet Download