Process for producing printed circuit board by electroless plating

A process for producing a printed circuit board comprising forming a plating film forming adhesive layer on both whole exposed surfaces of an insulating board, roughening the surface of said adhesive layer, depositing a catalyst for electroless plating on said adhesive layer surface from a catalyst solution, masking the board surface excepting the part where a circuit is to be formed, and forming a circuit on the board by electroless plating, wherein an improvement comprises a step of providing throughholes after the formation of the adhesive layer but before the roughening of the adhesive layer, a step of treating the roughened adhesive layer surface with an alkali aqueous solution before depositing the catalyst and a step of treating the insulating board, which has been masked excepting the part where a circuit is to be formed, with an aqueous solution containing a surfactant before conducting the electroless plating on said board, whereby stability of the electroless plating bath used in said electroless plating is maintained through repeated uses of said bath.

A process for producing a printed circuit board comprising forming a plating film forming adhesive layer on at least one whole exposed surface of each insulating boards, the surface forming the outer most layer of laminated printed boards, roughening the surface of said adhesive layer, depositing a catalyst for electroless plating on said adhesive layer surface from a catalyst solution, masking the board surface excepting the part where a circuit is to be formed, and forming a circuit on the board by electroless plating, wherein an improvement comprises a step of treating the roughened adhesive layer surface with an alkali aqueous solution before depositing the catalyst and a step of treating the insulating board, which has been masked excepting the part where a circuit is to be formed, with an aqueous solution containing a surfactant before conducting the electroless plating on said board, whereby stability of the electroless plating bath used in said electroless plating is maintained through repeated uses of said bath.

A process for producing a printed circuit board comprising forming a plating film forming adhesive layer on the whole exposed surface of an insulating board, roughening the surface of said adhesive layer, depositing a catalyst for electroless plating on said adhesive layer surface from a catalyst solution, masking the board surface excepting the part where a circuit is to be formed, and forming a circuit on the board by electroless plating, wherein an improvement comprises a step of treating the roughened adhesive layer surface with an alkali aqueous solution before depositing the catalyst, a step of treating the insulating board, which has been masked excepting the part where a circuit is to be formed, with an aqueous solution containing a surfactant before conducting the electroless plating on said board, whereby stability of the electroless plating bath used in said electroless plating is maintained through repeated uses of said bath, and a step of conducting the electroless plating in a waterwashed, wet state after the surfactant treatment.

A process for producing a printed circuit board which comprises forming a plating film forming adhesive layer on the whole exposed surface of an insulating board, roughening the surface of said adhesive layer, treating the roughened adhesive layer surface with an alkali aqueous solution, depositing a catalyst for electroless plating on the roughened surface from a catalyst solution, masking the board surface excepting the part where a circuit is to be formed, treating the insulating board, which has been masked excepting the part where a circuit is to be formed, with an aqueous solution containing a surfactant and forming a circuit on the board by electroless plating, whereby, by the treating with an alkali aqueous solution and the treating with an aqueous solution containing a surfactant, stability of the electroless plating bath used for said electroless plating is maintained through repeated uses of said bath.