What is this component (is it a rectifier?)
It seems like an IGBT (or similar) three phase bridge module. Usually something like 6 IGBT thermally bonded to efficiently drive a 3-phase motor. Often they have nice features like thermal sensors and integrated gate drive (optimized for the transistors). Search for 3-phase IGBT pack or something like that, Semikron does some nice ones for example (but many other too, look at Infineon, On Semi, etc)