An electroless gold plating solution comprising a thiosulfato gold(I) complex, a thiosulfate, thiourea, a pH regulator and a stabilizer. The electroless gold plating solution shows a plating rate and a plating solution stability comparable to those of conventional gold plating solutions containing cyanide ions, and requires a smaller amount of reducing agent to be used therein. Further, the electroless gold plating solution is safe because it does not contain cyanide ions.

Electroless gold plating solution

An electroless gold plating bath includes a water-soluble gold compound, a complexing agent, a formaldehyde metabisulfite adduct, and an amine compound represented by R 1 —NH—C 2 H 4 —NH—R 2 or (CH 2 —NH—C 2 H 4 —NH—CH 2 ) n—R 4 (wherein R 1 to R 4 represent —OH, —CH 3 , —CH 2 OH, —C 2 H 4 OH, —CH 2 N(CH 3 ) 2 , —CH 2 NH(CH 2 OH), —CH 2 NH(C 2 H 4 OH), —C 2 H 4 NH(CH 2 OH), —C 2 H 4 NH(C 2 H 4 OH), —CH 2 N(CH 2 OH) 2 , —CH 2 N(C 2 H 4 OH) 2 , —C 2 H 4 N(CH 2 OH) 2 or —C 2 H 4 N(C 2 H 4 OH) 2 , and n is an integer of 1 to 4). A gold plated coating of a good appearance can be formed without causing a failure in appearance owing to the progress of intergranular corrosion in a nickel surface.

Electroless gold plating bath, electroless gold plating method and electronic parts

PROBLEM TO BE SOLVED: To provide an electroless gold plating solution which can form a good plating film on an electroless nickel plating film and can minimize the corrosion of the nickel plating film. SOLUTION: The electroless gold plating film contains (i) a water-soluble gold compound, (ii) a complexing agent, (iii) at least one component selected from the group consisting of acids including chalcogen elements of an oxidation number 2 to 4 and their salts, (iv) at least one component selected from the group consisting of hydrazine and its derivative, and (v) a compound having an ethylene group including ≥2 imono groups within the molecule and having a substituent in some cases between the nitrogen atoms of the imino group. COPYRIGHT: (C)2004,JPO

PROBLEM TO BE SOLVED: To provide a reduction precipitation type electroless gold plating liquid which can be directly precipitated on a palladium film, and is favorable, in particular, for the surface treatment of a conductor circuit of a printed circuit board. SOLUTION: The reduction precipitation type electroless gold plating liquid which is used to directly deposit a gold plating film on a palladium film consists of an aqueous solution containing a water-soluble gold compound, a reducing agent and a complexing agent, and contains at least one kind of compound selected from a group consisting of formaldehyde bisulfites, rongalit, and hydrazines as the reducing agent. An electroless nickel plating film, an electroless palladium plating film, and an electroless gold plating film deposited by using the reduction precipitation type electroless gold plating liquid are successively deposited on the conductor part of the printed circuit board. COPYRIGHT: (C)2008,JPO&INPIT

Reduction precipitation type electroless gold plating liquid for palladium film

PROBLEM TO BE SOLVED: To provide an electroless gold plating liquid capable of obtaining a hard gold film. SOLUTION: The electroless gold plating liquid comprises one or more hardeners selected from the group consisting of cobalt compounds, nickel compounds and iron compounds, and an ascorbic acid derivative. COPYRIGHT: (C)2007,JPO&INPIT

Electroless hard gold plating liquid

PROBLEM TO BE SOLVED: To obtain an excellent electrolytic compsn. for the immersion plating of gold onto a substrate by incorporating oner or more water soluble gold compds., one or more organic conductive salts, one or more reducing agents and water. SOLUTION: As the suitable water soluble gold compds., an alkali gold sulfite compd., alkali gold cyanide or the like is given, and particularly, a calcium gold cyanide is preferable. As the suitable conductive salts, the alkali metal salt of organic phosphoric acid, amine carboxylic acid, carboxylic acid or the dielectrics thereof are given. As the suitable reducing agents, hydrazine, hydrazine hydrate, or the like is given. Preferably, the concn. of gold in the electrolytic compsn. is controlled to about 0.25 to 8 g/l, the concn. of the conductive salts is controlled to about 10 to 300 g/l, and the concn. of the reducing agents is controlled to about 0.1 to 20 g/l. Further, the pH of the electrolytic compsn. is preferably controlled to about 4 to 9 and can be controlled by using basic or acidic substance.

Electroless gold plating solution and method

PROBLEM TO BE SOLVED: To provide an electroless gold plating solution, which little erodes an underlying metal, and provides improved adhesiveness to the underlying metal and consequent strong soldering strength, and to provide a method for electroless plating gold. SOLUTION: The electroless gold plating solution includes (a) a water-soluble gold compound, (b) a complexing agent (for example, organic phosphonic acid such as aminotrimethylene phosphonic acid), which stabilizes gold ions in the plating solution, but substantially does not dissolve nickel, cobalt or palladium of the underlying metal, into the plating solution, and (c) polyethyleneimine. The plating method is characterized by employing the above solution.

Electroless gold plating solution and method for electroless plating gold

PROBLEM TO BE SOLVED: To provide an electroless gold plating soln. forming a gold plating film extremely excellent in adhesion between the substitution gold plating film to be formed and a base metal film selected from the groups of nickel, cobalt, palladium and alloys contg. these metals and to provide a method of executing electroless gold plating treatment by using it. SOLUTION: As essential components, this soln. contains the following (a) to (c): (a) a water soluble gold compd., (b) a complexing agent which stabilizes gold ions into a plating soln. but substantially does not dissolve nickel, cobalt or palladium and (c) a gold precipitation inhibitor capable of suppressing the partial and excessive etching of the base metal generated at the time of executing gold plating by substitution reaction with the base metal.

Electroless gold plating method and electroless gold plating solution used therefor

PROBLEM TO BE SOLVED: To provide the electroless gold plating liquid and the method for electroless gold plating using the same, which is capable of forming a plated gold layer having improved adhesion to a substrate metal, without breaking an organic resist. SOLUTION: The method for the electroless gold plating comprises subjecting a substrate to be plated having a surface, which comprises metals selected from the group consisting of Ni, Co, Pd and alloys thereof, to electroless gold plating at a pH of <=10 in an electroless gold plating liquid containing the following components: (a) a compound capable of providing gold ion, (b) a complexing agent which has the ability to stabilize gold ion but does not dissolve Ni, Co or Pd at a pH of <=10 and (c) a reducing agent capable of being oxidized by Ni, Co or Pd.

康夫太田

Papers

Electroless gold plating solution and method

Electroless gold plating solution and method for electroless plating gold

Electroless gold plating method and electroless gold plating solution used therefor

Electroless gold plating liquid and method for electroless gold plating

康夫 太田

Papers

Electroless gold plating solution and method

Electroless gold plating solution and method for electroless plating gold

Electroless gold plating method and electroless gold plating solution used therefor

Electroless gold plating liquid and method for electroless gold plating

康夫太田