Hitachi, Ltd.

Eiji Takai

Haruo Akahoshi

Takeyuki Itabashi

Naoki Nishimura

Tadashi Iida

Yoshinori Ueda

Hiroshi Kanemoto

An electroless copper plating solution using glyoxylic acid as a reducing agent, which is small in the reacting quantity of Cannizzaro reaction, does not largely cause precipitation of the salt accumulated in the electroless copper plating solution by the plating reaction and Cannizzaro reaction, and can be used stably over a long period of time. The electroless copper plating solution comprises copper ion, a complexing agent for copper ion, a reducing agent for copper ion and a pH adjusting agent, wherein the reducing agent for copper ion is glyoxylic acid or a salt thereof, the pH adjusting agent is potassium hydroxide and the electroless copper plating solution contains at least one member selected from metasilicic acid, metasilicic acid salt, germanium dioxide, germanic acid salt, phosphoric acid, phosphoric acid salt, vanadic acid, vanadic acid salt, stannic acid and stannic acid salt in an amount of 0.0001 mol/L or more.

Electroless copper plating solution, electroless copper plating process and production process of circuit board

A multilayer wiring substrate which is high in connection reliability is provided through process steps of forming more than one opening, such as a via-hole in a dielectric layer laminated on a substrate, and then applying uniform copper plating to a surface portion of the dielectric layer including the opening to thereby form a wiring layer. An electroless copper plating solution with at least one of mandelonitrile and triethyltetramine mixed therein is used to perform the intended electroless copper plating. An alternative process makes use of an electroless copper plating solution with chosen additives or 'admixtures' containing at least on of mandelonitrile and triethyltetramine plus eriochrome block T along with at least one of 2,2'-bipyridyl, 1,10-phenanthroline, and 2,9-dimethyl-1,10-phenanthroline

Method of manufacturing a wiring substrate and an electroless copper plating solution for providing interlayer connections

A method is provided for removing plating blocking ions, such as anions, in pairs with copper ions and oxidant ions of a copper ion reducing agent from an electroless copper plating solution and keeping a constant salt concentration in the electroless copper plating solution during plating. The electroless copper plating method uses a plating solution containing copper sulfate as copper ion sources, and a copper ion complexing agent as copper ion sources, glyoxylic acid as a copper ion reducing agent, and a pH conditioner. The method is characterized by precipitating and removing sulfuric and oxalic ions in said electroless copper plating solution and keeping an optimum concentration of at least one of sulfuric and oxalic ions in said electroless copper plating solution during plating.

Electroless copper plating machine, and multi-layer printed wiring board

A multilayer wiring substrate which is high in connection reliability is provided through process steps of forming more than one opening, such as a via-hole in a dielectric layer laminated on a substrate, and then applying uniform copper plating to a surface portion of the dielectric layer including the opening to thereby form a wiring layer. An electroless copper plating solution with at least one of mandelonitrile and triethyltetramine mixed therein is used to perform the intended electroless copper plating. An alternative process makes use of a electroless copper plating solution with chosen additive agents or &ldquo;admixtures&rdquo; containing at least one of mandelonitrile and triethyltetramine plus eriochrome black T along with at least one of 2,2&prime;-bipyridyl, 1,10-phenanthroline, and 2,9-dimethyl-1,10-phenanthroline.

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Yokohama, Japan

Eiji Takai