Hitachi, Ltd.

Akira Tomizawa

Hitoshi Yokono

Osamu Miyazawa

Jiro Ushio

Hiroshi Kikuchi

Hitoshi Oka

Naoya Kanda

Hiroaki Okudaira

Isamu Tanaka

Setsuo Ando

Naoko Matsuura

The present invention relates to an electroless gold plating solution, a method of plating by using the same, and an electronic device plated with gold by using the same. According to the present electroless gold plating solution, the plating solution components contain no cyanide ions, the amount of a reducing agent used is small, and gold plating can be carried out without causing the gold plating on conducting paths having a fine interval between them to short-circuit the conducting paths. Therefore, according to the method of gold plating by using said electroless gold plating solution, a plating method that is safe in the plating work and in the treatment of its waste liquor can be accomplished. The method has a feature that the method can provide an electronic device on which parts can be mounted highly densely, and wherein the joint reliability to the parts is high.

Electroless gold plating solution, method of plating with gold by using

Electronic device plated with gold by means of an electroless gold

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 copper plating solution comprising cupric ions, complexing agents, a reducing agent, a pH adjustor, a polyoxyethylene series surface active agent, these being conventionally used, and (i) an inorganic compound containing at least Si or Ge, or (ii) a cationic surface active agent, or (iii) an inorganic compound containing at least Si, Ge or V and a cationic surface active agent, can give plated films with excellent mechanical properties even if operated for a long period of time with excellent stability of the plating solution.

Electroless copper plating solution

An epoxy resin composition containing as a latent hardener a diaminotriazine-modified imidazole compound and dicyandiamide is improved in the usable life of an solder resist ink composition and can give a solder resist also excellent in resistance to an electroless plating bath.

Epoxy resin composition

An epoxy resin composition comprising an epoxide compound, a guanidine compound, a filler, a thixotropic agent and an organic solvent and having a thixotropy index of 5 to 40 and a viscosity of 800 to 10,000 poises (at 20.degree. C.) is suitable for forming a resist film which is used in electroless metal plating with excellent heat resistance, solder resistance and corrosion resistance, and the like.

Growing community of inventors

Yokohama, Japan

Akira Tomizawa