Compositions and methods for silver plating onto metal surfaces such as PWBs in electronics manufacture to produce a silver plating which is greater than 80 atomic % silver, tarnish resistant, and has good solderability.

The invention eliminates defects generated in a metal filling a through hole of a printed board by changing an angle at which a plating solution is sprayed or by changing a posture of the printed board at a time point in a process of precipitating the metal from the plating solution and filling the through hole with the precipitated metal while the plating solution or air bubbles are being sprayed onto the printed board.

An apparatus and method for measuring the isoelectric pH for materials deposited on or otherwise affixed onto and in contact with an electrode surface, and a method for utilizing the isoelectric pH to form nanometer thickness, self-assembled layers on the material, are described. Forming such layers utilizing information obtained about the isoelectric pH values of the substrate and the coating is advantageous since the growth of the coating is self-limiting because once the surface charge has been neutralized there is no longer a driving force for the solid electrolyte coating thickness to increase, and uniform coatings without pinhole defects will be produced because a local driving force for assembly will exist if any bare electrode material is exposed to the solution. The present self-assembly procedure, when combined with electrodeposition, may be used to increase the coating thickness. Self-assembly, with or without additional electrodeposition, allows intimate contact between the anode, electrolyte and cathode which is required for successful application to solid-state batteries, as an example.

Provided is a substrate plating apparatus capable of simultaneously circulating and stirring a plating solution and removing air bubbles. The plating apparatus includes a hybrid paddle disposed in front of a substrate in a plating bath to stir the plating solution. Here, the hybrid paddle includes a spray assembly for spraying the plating solution toward the substrate and a suction assembly for suctioning air bubbles formed on the substrate during plating, and the spray assembly and the suction assembly are coupled into one body and perform a reciprocating movement along a surface of the substrate to stir the plating solution.

Provided is a semiconductor element including: a front-back conduction-type substrate including a front-side electrode and a back-side electrode; and an electroless plating layer formed on at least one of the electrodes of the front-back conduction-type substrate. The electroless plating layer includes: an electroless nickel-phosphorus plating layer; and an electroless gold plating layer formed on the electroless nickel-phosphorus plating layer, and has a plurality of recesses formed on a surface thereof to be joined with solder.

The present invention relates to a method for monitoring the total amount of sulphur containing compounds in a metal or metal alloy plating bath, wherein the sulphur containing compounds contain at least one sulphur atom having an oxidation state below +6, the method comprising the steps (a), (b), optionally (c), and (d). Said method is a means of providing control over a metal plating process. Thus, the present invention relates furthermore to a controlled process for plating a metal on a substrate utilizing the method of the present invention for monitoring the total amount of said sulphur containing compounds.

Disclosed is a method of producing a catalyst. The method includes: dispersing, in an acid solution, a composite in which a plurality of raw material microparticles containing a noble metal is supported on a carbon support doped with a nitrogen atom and a first transition metal atom; immersing a noble metal member in the acid solution; and alternately blowing a first gas containing an oxidizing gas and a second gas containing a reducing gas into the acid solution.

A surface treatment device includes at least one paddle in a plate shape, in a surface treatment tank, for stirring a surface treatment solution near an object to be plated by reciprocally moving the paddle with respect to the object to be plated. The paddle is configured by integrally forming multiple square bars provided in a depth direction or a horizontal direction of the surface treatment solution at regular intervals along the object to be plated. A liquid draining member for draining a liquid is arranged in at least one side of an end of the paddle.

An oxygen-free or oxygen-poor solution for the electroless deposition of a platinum group metal is described. The solution includes a ruthenium (II) amine complex having a first oxidation potential, and a platinum group metal compound having a reduction potential larger than the opposite of the oxidation potential of the ruthenium (II) amine complex.

An object of the present invention is to provide an electroless plating bath having excellent property in plating film deposition without containing halides such as chloride in the electroless plating bath. A halogen-free electroless plating bath of the present invention comprising: a water soluble platinum compound or a water soluble palladium compound, and a reducing agent wherein the water soluble platinum compound is a tetraammine platinum (II) complex salt excluding a halide of the tetraammine platinum (II) complex salt, the water soluble palladium compound is a tetraammine palladium (II) complex salt excluding a halide of the tetraammine palladium (II) complex salt and tetraammine palladium (II) sulfate, the reducing agent is formic acid or its salts, and the electroless plating bath contains no halide as an additive.