This part is a kind of semiconductor called K15H1203.

Function of this product has IKW15N120H3 IGBT.

Manufacturers : Infineon

Image and pinout :

Some of the text within the PDF file :

IGBT HighspeedDuoPack:IGBTinTrenchandFieldstoptechnologywithsoft,fastrecovery anti-paralleldiode IKW15N120H3 1200Vhighspeedswitchingseriesthirdgeneration Datasheet IndustrialPowerControl IKW15N120H3 Highspeedswitchingseriesthirdgeneration HighspeedDuoPack:IGBTinTrenchandFieldstoptechnologywithsoft,fast recoveryanti-paralleldiode  Features: C TRENCHSTOPTMtechnologyoffering •verylowVCEsat •lowEMI •Verysoft,fastrecoveryanti-paralleldiode •maximumjunctiontemperature175°C •qualifiedaccordingtoJEDECfortargetapplications •Pb-freeleadplating;RoHScompliant •completeproductspectrumandPSpiceModels: http://www.infineon.com/igbt/ G E Applications: •uninterruptiblepowersupplies •weldingconverters [ ... ]

K15H1203 PDF Datasheet Download