Ngk Spark Plug Company, Limited

Tsuneyuki Sukegawa

Kazuo Kondo

Asao Morikawa

Hisaharu Shiromizu

A ceramic substrate for an electrical device such as a layered circuit or an integrated circuit formed of a crystalline glass or ceramic material having a low densifying temperature such that conductor materials and circuits can be readily formed from high conductivity metals.

Ceramic substrate for electrical devices

A process for producing a multilayer circuit board composed of crystallized glass and copper-metallized circuit patterns, which comprises: (1) providing a green sheet of a crystallizable glass powder; (2) providing a copper paste comprising copper component (copper and/or copper oxide) and a glass powder in a proportion by weight of the copper component to the glass powder 95:5 to 75:25, copper oxide being calculated on copper; (3) printing a circuit pattern of the copper paste of step (2) on the green sheet of step (1); (4) coating on the green sheet of step (3) an insulating paste to form an insulating layer except for regions assigned for through holes; (5) printing on the insulating layer of step (4) a circuit pattern of the copper paste of step (2) and filling said holes with the copper paste make a conductive connection through said holes; (6) decomposing the binders by heating the product of step (5) under an oxidizing atmosphere at 400.degree.-850.degree. C.; and (7) heating the product of step (6) at 850.degree.-1050.degree. C. under a reducing atmosphere for a period of time sufficient to reduce copper oxide, sinter the product of step (6) and crystallize said glasses. After step (5), pairs of steps (4) and (5) are repeated to make multilayer circuit boards.

Process for producing multilayer circuit board

A method of connecting a metal conductor to a ceramic substrate including the steps of providing a terminal portion on the ceramic substrate, the ceramic substrate having a dielectric constant less than or equal to 7.0 units and a coefficient of thermal expansion of 5.times.10.sup.-6 /.degree. C. or less, forming at least one of a buffer layer and a barrier layer overlying the terminal portion of the ceramic substrate, wherein the buffer layer consists essentially of Cu and the barrier layer consists essentially of a material selected from the group consisting of Ni, Pd, and Pt, and brazing a metal conductor to the terminal portion of the ceramic substrate through the at least one of the buffer layer and the barrier layer with an Ag-based brazing filler material.

Method of connecting metal conductor to ceramic substrate

A substrate for supporting an integrated circuit made of a ceramic member with a thin film of conductive metal applied to the ceramic member. The ceramic member consists essentially of a sintered ceramic material capable of forming a surface finish upon sintering, having a roughness that is less than 10 times the thickness dimension of the conductive film applied thereto. The ceramic material is either crystalline glass or a glass-coated ceramic.

Growing community of inventors

Aichi, Japan

Tsuneyuki Sukegawa