An electroless plating process that enables reduction in production costs and a two-layer plating film obtained by the process including an electroless plating process for forming a nickel plating film and a gold plating film in this order on a surface of a copper material by a electroless plating method. The electroless plating process includes a step of forming a nickel plating film containing boron by a reductive electroless nickel strike plating method, and a step of forming a gold plating film by a reductive electroless gold plating method. The two-layer plating film according to the present disclosure is formed by this process.

An object is to coat a target position on a substrate with a dense film. In order to achieve the object, while a substrate on which a base containing a coating material is formed is transported, an auxiliary agent is applied to the substrate, and then a main agent containing a coating material is applied to the substrate to react the main agent with the auxiliary agent, so that a portion on the substrate where the base is formed is coated with the coating material.

An object is to coat a target position on a substrate with a dense film. In order to achieve the object, while a substrate on which a base containing a coating material is formed is transported, an auxiliary agent is applied to the substrate, and then a main agent containing a coating material is applied to the substrate to react the main agent with the auxiliary agent, so that a portion on the substrate where the base is formed is coated with the coating material.

An assembly for electroless metallization of a target surface (11) of at least one workpiece (10), comprising—a container (13) for receiving an electrolyte solution—an inlet for the electrolyte solution, said inlet arranged in the base (15) of the container (13), wherein the inlet (20) is designed as an inlet port (21) with a diffuser plate (24) comprising inlet openings (25) arranged in concentric circles—an outlet (30) which is arranged on an upper side of the container (13)—a receiving area for holding the at least one workpiece (10), wherein the diffuser plate (24) is formed as a first assembly (31) and a second assembly (32), which is identical to the first assembly, of a respective plurality of inlet openings (25), wherein the assemblies at least partially but not completely overlap, and the inlet (20) has at least two inlet ports (21, 22).

An assembly for electroless metallization of a target surface (11) of at least one workpiece (10), comprising—a container (13) for receiving an electrolyte solution—an inlet for the electrolyte solution, said inlet arranged in the base (15) of the container (13), wherein the inlet (20) is designed as an inlet port (21) with a diffuser plate (24) comprising inlet openings (25) arranged in concentric circles—an outlet (30) which is arranged on an upper side of the container (13)—a receiving area for holding the at least one workpiece (10), wherein the diffuser plate (24) is formed as a first assembly (31) and a second assembly (32), which is identical to the first assembly, of a respective plurality of inlet openings (25), wherein the assemblies at least partially but not completely overlap, and the inlet (20) has at least two inlet ports (21, 22).

A method that forms a metal plating film having a thick film thickness by a solid phase method is provided. The present disclosure is a method that forms the metal plating films of a first metal and a second metal having an ionization tendency larger than an ionization tendency of the first metal. The method includes: depositing the second metal on a surface of a copper base material to form the plating film of the second metal; and depositing the first metal on a surface of the second metal by a solid electroless plating method to form the plating film of the first metal. The solid electroless plating method in the depositing of the first metal is performed using a laminated complex. The laminated complex includes a first substitution-type electroless plating bath, a solid electrolyte membrane, a copper base material, a third metal, a second substitution-type electroless plating bath, and an insulating polymer. The first substitution-type electroless plating bath contains ions of the first metal. The second metal is plated on the copper base material. The third metal has an ionization tendency larger than the ionization tendency of the first metal. The second substitution-type electroless plating bath contains ions of the first metal.

A method that forms a metal plating film having a thick film thickness by a solid phase method is provided. The present disclosure is a method that forms the metal plating films of a first metal and a second metal having an ionization tendency larger than an ionization tendency of the first metal. The method includes: depositing the second metal on a surface of a copper base material to form the plating film of the second metal; and depositing the first metal on a surface of the second metal by a solid electroless plating method to form the plating film of the first metal. The solid electroless plating method in the depositing of the first metal is performed using a laminated complex. The laminated complex includes a first substitution-type electroless plating bath, a solid electrolyte membrane, a copper base material, a third metal, a second substitution-type electroless plating bath, and an insulating polymer. The first substitution-type electroless plating bath contains ions of the first metal. The second metal is plated on the copper base material. The third metal has an ionization tendency larger than the ionization tendency of the first metal. The second substitution-type electroless plating bath contains ions of the first metal.

A silver-coated resin particle having a resin particle and a silver coating layer provided on a surface of the resin particle, in which an average value of a 10% compressive elastic modulus is in a range of 500 MPa or more and 15,000 MPa or less and a variation coefficient of the 10% compressive elastic modulus is 30% or less.

The disclosed process is capable of depositing thin layers of a wide variety of metals onto powders of magnesium, aluminum, and their alloys. A material is provided that comprises particles containing a reactive metal coated with a noble metal that has a less-negative standard reduction potential than the reactive metal. The coating has a thickness from 1 nanometer to 100 microns, for example. A method of forming an immersion deposit on a reactive metal comprises: combining a reactive metal, an ionic liquid, and a noble metal salt; depositing the noble metal on the reactive metal by a surface-displacement reaction, thereby generating the immersion deposit on the reactive metal; and removing the ionic liquid from the immersion deposit. The material may be present in an article or object (e.g., a sintered part) containing from 0.25 wt % to 100 wt % of a coated reactive metal as disclosed herein.

A heteroepitaxial structure includes a first metal portion having a polycrystalline structure, a second metal portion on the first metal portion, the second metal portion has an island-shaped structure on the first metal portion, the second metal portion is provided corresponding to at least one crystalline grain exposed to a surface of the first metal portion, and the second metal portion and the at least one crystalline grain have a heteroepitaxial interface.