A method for manufacturing a
printed circuit board with a conical optical
waveguide includes the following steps that firstly, a substrate is manufactured, wherein the substrate is formed by a
copper-clad plate, a medium layer is arranged in the middle of the
copper-clad plate, and
copper layers are arranged on the two sides of the copper-clad plate; secondly, an optical
waveguide layer is manufactured, wherein an upper wrapper, a core layer and a lower wrapper are sequentially manufactured on the substrate, wherein the area of the cross section of the core layer of the optical
waveguide gradually decreases in the optical
signal propagation direction, the area of the cross section of the input end of the core layer of the optical waveguide is larger than the area of the cross section of the output end of the core layer, and then the conical optical waveguide is formed; thirdly, a matched
printed circuit board is manufactured; fourthly, the
printed circuit board and the substrate with the optical waveguide layer are laminated to form a mixed plate with the optical waveguide layer and the copper
layers; fifthly, the mixed plate is subsequently machined through the drilling step, the
electroplating step, the graph manufacturing step, the green oil
coating step, the
surface processing step, the cleaning step, the examining step, the cleaning step and the packaging step. According to the method, optical
waveguide coupling loss of the circuit board can be effectively reduced, and the alignment tolerance of an
optical fiber or the optical waveguide can be increased under the same
coupling loss requirement.