Abstract: Adhesive agent for substrate of electroless plating characterized in comprising epoxy resin, synthetic rubber, and phenolic resin as main components, a hardener of the epoxy resin, inorganic filler having hydroxyl group, and solvent.The adhesive agent is hardened at relatively low temperature (about 150.degree. C.) in short period (within 30 minutes) without giving warp and distortion to the insulation substrate, and moreover its insulation resistance after hardening is high.The adhesive agent is preferable as an adhesive agent for a printed circuit board.

Abstract: A process for producing a printed circuit board, which comprises the steps of forming a layer comprising a photosensitive resin composition on an insulating substrate having on its surface an adhesive layer adherent to a metal being subsequently plated thereon; exposing said layer comprising a photosensitive resin composition to an actinic radiation in a manner so as to form on said layer a negative pattern of a conductor circuit pattern and to semicure said negative pattern to an extent sufficient to keep it from erosion by a plating solution; developing by dissolving away with a solvent the uncured areas not exposed to said actinic radiation, thereby to form a plating resist on the areas of said negative pattern; chemically plating said conductor circuit pattern areas not covered with said plating resist, thereby to form a conductor circuit; and carrying out a curing treatment to cure completely said resist.

Abstract: An electroless copper plating process for producing fine patterned wiring boards is improved by supplying very fine oxygen-containing gas bubbles through a porous alkali-resistant resin gas dispersing tube. An electroless copper plating apparatus having such a gas dispersing tube is also provided.

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: This invention concerns a method for the manufacture of a printed wiring board which particularly proves useful as a printed coil. This method is characterized by the fact that in the work in process which has undergone the step for formation of a conductor circuit and which has not undergone the step for separation of a plating resist, the plating resist and other insulating substratal material are separated for transfer from the surface of the substrate having the conductor circuit formed thereon.Since this method permits formation of an extremely thin insulating layer and a conductor circuit layer thicker than the insulating layer, it enables production of very thin printed wiring board and printed coil having high circuit density in the surfaces of component layers as well as in the direction of superposition of component layers.

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.

Abstract: During recyclic use of a chemical copper plating solution, counter anions to copper ions, anions formed by oxidation of a reducing agent, and carbon dioxide by absorption of carbon dioxide from air, which all have an inhibiting effect upon the plating, and also sodium ions having no inhibiting effect are accumulated in the plating solution.These accumulated ions can be removed by electrodialysis. Particularly, regeneration can be satisfactorily regenerated by adjusting the pH of used chemical plating solution to 2-11 before the electrodialysis, and using a selectively monovalent anion permeable membrane as an anion exchange membrane at the electrodialysis.