Catalysts include nanoparticles of catalytic metal and starch as a stabilizer in molar ratios which enable stabilization of the catalyst during storage and during electroless metal plating. The catalysts are environmentally friendly and are tin free. The catalysts adhere well to dielectric materials of printed circuit boards including the walls of through-holes.

A via in a printed circuit board is composed of a patterned metal layer that extends through a hole in dielectric laminate material that has been covered with catalytic adhesive material on both faces of the dielectric laminate material. The layer of catalytic adhesive coats a portion of the dielectric laminate material around the hole. The patterned metal layer is placed over the catalytic adhesive material on both faces of the dielectric laminate material and within the hole.

Pyrazine derivatives which contain one or more electron donating groups on the ring are used as catalytic metal complexing agents in aqueous alkaline environments to catalyze electroless metal plating on metal clad and un-clad substrates. The catalysts are monomers and free of tin and antioxidants.

The present invention provides an absorbing-layer-forming composition including a blocked isocyanate such that the amount of the blocked isocyanate is 50% by mass to 100% by mass of the solid content of the absorbing-layer-forming composition and an absorbing substrate, a printed item, and a conductive pattern that are formed using the absorbing-layer-forming composition. The absorbing-layer-forming composition according to the present invention can be used for forming an absorbing layer which is capable of carrying a fluid such as an ink therein and which enables good adhesion between various types of supports and a conductive layer to be achieved. In particular, using a blocked isocyanate having a number-average molecular weight of 1,000 to 5,000 further increases the adhesion between various types of supports and the conductive layer.

A substrate for a printed circuit board includes a base film having an insulating property; a first conductive layer formed on at least one of surfaces of the base film by application of a conductive ink containing metal particles; and a second conductive layer formed, by plating, on a surface of the first conductive layer, the surface being on a side opposite to the base film, wherein a region near an interface between the base film and the first conductive layer contains a metal oxide species based on a metal of the metal particles and a metal hydroxide species based on the metal of the metal particles, the metal oxide species in the region near the interface between the base film and the first conductive layer has a mass per unit area of 0.1 g/cm.sup.2 or more and 10 g/cm.sup.2 or less, and a mass ratio of the metal oxide species to the metal hydroxide species is 0.1 or more.

Provided are a method for forming a high-definition metal pattern which including the steps of (1) forming a receiving layer on a substrate by coating the substrate with a resin composition including a urethane resin having a weight-average molecular weight of five thousand or more or a vinyl resin and a medium, (2) forming a plating-core pattern on the receiving layer by printing an ink including a particle that serves as a plating core on the receiving layer by reverse offset printing, and (3) depositing a metal on the plating-core pattern by electroless plating, a high-definition metal pattern formed by the above-described method, and an electronic component including the high-definition metal pattern.

Pyrazine derivatives which contain one or more electron donating groups on the ring are used as catalytic metal complexing agents in aqueous alkaline environments to catalyze electroless metal plating on metal clad and un-clad substrates. The catalysts are monomers and free of tin and antioxidants.

A catalyst ink for plating and a method for electrochemically manufacturing an electronic device by using same are disclosed. The present invention provides a catalyst ink for plating, comprising: a polymer binder; a metal ion as a catalyst; a silane coupling agent for coupling the metal ion and the polymer; and a solvent, wherein the polymer has a lower critical solution temperature in the temperature-composition phase diagram for a solvent-polymer binary system, and the lower critical solution temperature is 30 C. or higher. According to the present invention, a high resolution plated pattern having a line width and a width between lines can be manufactured.