Power module, power device and power module forming method

The invention provides a power module, a power device and a power module forming method, and the power module comprises a substrate which comprises a ceramic layer, and a first metal layer and a second metal layer which are disposed on the opposite surfaces of the ceramic layer; the chip assembly is arranged on the surface, away from the ceramic layer, of the first metal layer; the plastic packaging layer is arranged on the side, provided with the chip assembly, of the substrate, wraps the chip assembly, the first metal layer and the ceramic layer and at least wraps the partial side wall, close to the ceramic layer, of the second metal layer, and a groove is formed in the area, away from the side wall of the second metal layer, of the bottom face of the plastic packaging layer; the radiator is fixedly connected with one surface, away from the ceramic layer, of the second metal layer. According to the invention, when the plastic packaging layer is subjected to injection molding, the plastic packaging layer wra