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: A copper barrier type, nuclear fuel cladding is produced by forming an oxide layer on the inner wall surface of a tube of zirconium or zirconium alloy and then applying electroless copper plating to the oxide layer with a solution containing at least a copper salt, a complexing agent, a reducing agent, and 2,2'-dipyridyl, or further together with polyalkylene glycol as a plating solution. A good adhesiveness is obtained between the copper barrier layer and the oxide layer.

Abstract: Highly precise wiring formed on an insulating substrate can be obtained by electroless deposition without using a printing process. Said process is characterized by forming an adhesive layer containing a photo-setting substance on a substrate, exposing the adhesive layer to actinic light imagewisely so as to irradiate only portions other than those forming wiring, treating the surface of the substrate with a roughening solution so as to roughen the portions not exposed to actinic light, and subjecting to the conventional treatments for electroless deposition so as to form prescribed wiring on the portions not exposed to actinic light.

Abstract: Printed circuits are produced on an insulating substrate by electroless metal plating according to a method comprising steps of:(I) forming a plating resist on a negative pattern of circuit with a masking material having an effect upon reducing the deposition of an initiator for electroless metal plating, and depositing the initiator onto the entire surface of the insulating substrate,(II) removing the initiator from the surface of said resist, and(III) dipping the insulating substrate in an electroless metal plating solution, thereby forming an electroless metal plating on a positive pattern of circuit, wherein a thermosetting resin containing a rutile type solid solution of metal oxides of titanium, nickel and antimony is employed as the masking material in said step (I), and the initiator is removed from the surface of the resist through contact with a hydrochloric acid solution of ammonium persulfate in said step (II).

Abstract: An electroless copper solution capable of forming an electroless deposited copper film having as a higher elongation as that of electro deposited copper film is provided, which is characterized by adding either 2,2'-dipyridyl or 2,9-dimethyl-1,10-phenanthroline, and polyethylene glycol to the well known electroless copper solution containing a copper salt, such as cupric sulfate, a complexing agent such as ethylenediaminetetraacetic acid, a reducing agent such as formalin, and a pH-adjusting agent such as alkali hydroxide as main components.The present copper solution can provide not only a higher elongation of deposited film, but also higher depositing rate, about 3 - 4 .mu.m/hr, which is equal or superior to that of the conventional art.