Method of producing ciruit board by additive method, and circuit board and multilayer circuit board obtained by the method

摘要

The present invention relates to a method of producing a circuit board, comprising:
a film-forming step of forming a resin film on the surface of an insulative substrate;
a circuit groove-forming step of forming circuit grooves having a depth equal to or greater than the thickness of the resin film on the external surface of the resin film;
a catalyst-depositing step of depositing a plating catalyst or the precursor thereof on the surface of the circuit grooves on the insulative substrate and the surface of the resin film;
a film-removing step of removing the resin film; and
a plating processing step of electroless-plating the insulative substrate after removal of the resin film, wherein
a partial reinforcing structure is formed in a region of the circuit groove in the circuit groove-forming step.