US Patent 11890832 Prepreg and metallic clad laminate

A prepreg and a metallic clad laminate are provided. The prepreg includes a reinforcing material and a thermosetting resin layer. The thermosetting resin layer is formed by immersing the reinforcing material in a thermosetting resin composition. The thermosetting resin composition includes a polyphenylene ether resin, a liquid polybutadiene resin, a crosslinker, and fillers. Based on a total weight of the thermosetting resin composition being 100 phr, an amount of the fillers ranges from 50 phr to 70 phr. The fillers include a granular dielectric filler and a flaky thermal conductive filler. The metallic clad laminate is formed by disposing at least one metal layer onto the prepreg.