Abstract: In a process for electroless copper plating in an electroless copper plating solution containing a copper salt, a complexing agent for the copper salt, a reducing agent for the copper salt, and a pH-adjusting agent, a plating film having distinguished mechanical properties can be obtained by adding at least one of soluble inorganic silicon compounds and soluble inorganic germanium compounds and conducting the electroless copper plating by injecting an oxygen-containing gas into the plating solution or by adding an oxidizing agent to the plating solution or by both injection or the oxygen-containing gas and addition of the oxidizing agent thereto. The stability of the electroless copper plating solution can be maintained better thereby and substantially thick plating is possible.

Abstract: A printed circuit board comprising an insulating board deposited with a catalyst having reactivity against electroless plating deposition, a resist for electroless plating provided on the insulating board excepting the part where a circuit is to be formed and a circuit formed by electroless plating, wherein the resist for electroless plating contains a coupling agent having a function of preventing the catalyst from ionizing. A process for producing the printed circuit board in which the insulating board surface excepting the part where a circuit is to be formed is covered with a resist for electroless plating containing a coupling agent having a function of preventing the catalyst from ionizing. Use of said resist for electroless plating can prevent drop of insulation resistance of the insulating board after moisture absorption.

Abstract: When an alkaline earth metal carbonate powder is mixed with an adhesive and is formed into an adhesive layer in a conventional covering method, a problem of the transfer of catalyst for electroless plating during a masking step or later electroless plating step is solved. Further, blisters under plated film caused by a fire retardant contained in an insulating substrate is also overcome by the use of alkaline earth metal powder.

Abstract: 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 said adhesive layer surface, depositing a catalyst for electroless copper plating on said adhesive layer surface from a catalyst solution, masking the thus treated insulating board surface excepting the part where a circuit is to be formed, and then performing the electroless copper plating on the catalyst of the board to form a circuit thereon, wherein an improvement comprises treating the roughened adhesive layer surface with an alkaline solution before depositing the catalyst thereon and treating the masked insulating board with an aqueous solution containing a surfactant before performing the electroless copper plating. The above process assures a higher copper utilization and a large adhesive strength of the copper plating to the board.