The invention discloses a reinforced composite PCB and a preparation method thereof, and belongs to the technical field of PCB preparation. The preparation method of the reinforced composite PCB comprises the following steps: step 1,
processing an inner-layer core board to obtain a preprocessed inner-layer core board; 2,
cutting, drilling and activating the modified
composite film to obtain a treated modified
composite film; and 3, sequentially carrying out stacking,
hot pressing treatment, pressure relief, cooling, drilling, hole metallization treatment, outer layer pattern transfer, pattern
electroplating, outer layer
etching, resistance
welding, surface treatment, molding and testing on a
copper foil, a prepreg, the pretreated inner layer core plate, the prepreg, the treated modified
composite film, the prepreg, the pretreated inner layer core plate, the prepreg and the
copper foil. And the composite PCB is obtained. The circuit board prepared by the method has excellent
thermal stability and mechanical properties.