Preparation method of multilayer circuit board

The invention discloses a preparation method of a multi-layer circuit board, and belongs to the technical field of circuit boards, in the preparation process, a composite film is used, dried polyether-ether-ketone, hydroxyl-terminated modified polyphenyl ether, a pretreated filler, modified N-benzyl maleimide and a silane coupling agent KH550 are uniformly mixed at a high speed, then melt extrusion, pelletizing and drying are performed to obtain blended plastic, and the blended plastic is subjected to extrusion molding to obtain the multi-layer circuit board. Performing two-way stretching to prepare a composite film; the method for preparing the multilayer circuit board is simple, the composite film is used as a prepreg, and quartz fibers and nano boron nitride in the composite film can enhance the mechanical property and increase the thermal conductivity. The polyphenyl ether is good in electrical insulativity and small in water absorption, the hydroxyl-terminated modified polyphenyl ether with the two ends