Packaging structure for high-power and high-current device and preparation method of packaging structure

The invention relates to the technical field of integrated circuit packaging, in particular to a packaging structure for a high-power and high-current device and a preparation method of the packaging structure. The packaging structure comprises a ceramic substrate with an aluminum nitride multilayer wiring structure and a metal cap arranged on the ceramic substrate, the metal cap is provided with a sealed inner cavity for accommodating an electronic device, and the electronic device arranged in the sealed inner cavity is attached to the surface of the ceramic substrate and is connected with the wiring structure; a composite film layer is further arranged on the surface of the ceramic substrate at the attaching position of the electronic device and the ceramic substrate, and the composite film layer sequentially comprises a seed layer, a DPC thick copper layer, a nickel layer and a gold layer on the surface of the ceramic substrate from bottom to top. The chip is directly assembled on the surface of the cerami