The invention discloses a manufacturing method of a printed circuit conductive circuit, and relates to the technical field of
printed circuit board manufacturing. The method comprises the following steps: (1) growing a
tin seed layer on the surface of a printed circuit insulating substrate; (2) covering the
tin seed layer with a patterned dry film; (3)
electroplating copper to form a
copper conductive circuit; (4) removing the dry film; (5) carrying out heat treatment on the substrate obtained after the treatment in the previous step, so that the
copper conductive circuit and the
tin seed layer are co-melted into a whole; and 6)
etching the tin seed layer to obtain a printed circuit conductive circuit. According to the method, the tin layer
etching speed is high, the precision is high, thecircuit is complete and free of side
etching, and manufacturing of a high-precision circuit board is facilitated; meanwhile, the copper and the tin are eutectic to form a uniform
alloy layer, so thatthe stress between the metals is released, the local defect caused by inconsistent etching speeds of the tin seed layer and the copper conductive wire is prevented, the
binding force of the conductive circuit and a bottom layer insulating medium is ensured, and the circuit pattern is good in
heat resistance, high in stability and high in reliability.