What is Theta JB and Theta JC for the STGIB20M60TS-L?

[Thales Vignoli]

What is Theta JB and Theta JC for the STGIB20M60TS-L - SLLIMM - 2nd series IPM, 3-phase inverter, 25 A, 600 V short-circuit rugged IGBT?

In the datasheet maybe i found the theta JC (junction case) but didnt have not information about JB (i think this is junction base). I need this informations to develop my heat sink.

Thanks!

[AWEI.2]

hi 

seen in the website , STPOWER Studio can also did the thermal simulation , can you use it for simulation . 

the datasheet actually didn't give out the JB JC info. without that way, seems no other way can got the information.