Kabushiki Kaisha Toshiba

Yoshiko Goto

Fumio Ueno

Akihiro Horiguchi

Mitsuo Kasori

Motomasa Imai

Naoki Shutoh

Naoki Shuto

Disclosed is a method of manufacturing a circuit board comprising an insulating substrate and a conductor pattern of a low resistivity which can be prevented from being peeled off the substrate by a thermal stress. The method comprises the step of forming an insulating layer on an insulating substrate, the insulating layer being provided with a groove having a depth of at least 20 .mu.m and shaped like a conductor pattern which is to be formed later, the step of filling the groove of the insulating layer with a paste composition consisting of a powdery material capable of forming an electrically conductive metal, a fine particles having a thermal expansion coefficient smaller than that of the electrically conductive metal, the fine particles being used in an amount of 0.5 to 20% by volume based on the amount of the electrically conductive metal, and an organic binder, and the step of baking the paste composition so as to form a conductor pattern on the insulating substrate, the conductor pattern containing as a main component the electrically conductive metal and the fine particles having a thermal expansion coefficient smaller than that of the metal, the fine particles being dispersed in the electrically conductive metal in an amount of 0.5 to 20% by volume based on the amount of the electrically conductive metal.

Method of manufacturing circuit board and circuit board itself

In an aluminum nitride structure, a plurality of aluminum nitride regions having different purities are integrally formed to satisfy a predetermined positional relationship, and neighboring regions are brought into direct contact with each other to form an abrupt junction therebetween. Therefore, the aluminum nitride structure has anisotropy in physical properties such as a thermal conductivity, a light transmittance, and a strength.

Method of manufacturing aluminum nitride structure with anisotropic

An aluminum nitride structure is prepared by placing an oxygen-trapping substance at at least one position on an aluminum nitride substrate having a first concentration of solution oxygen, and heating the resultant structure in a non-oxidizing atmosphere to locally reduce the first concentration of solution oxygen in said aluminum nitride substrate under said oxygen-trapping substance to a second concentration of solution oxygen by trapping the solution oxygen in the oxygen-trapping substance, thereby forming an aluminum nitride structure in which at least one region of the aluminum nitride structure corresponding to the position of said oxygen-trapping substance, which position has said second oxygen concentration, is integrally formed with aluminum nitride regions having said first concentration of solution oxygen. The aluminum nitride structure of the present invention exhibits anisotropic physical properties.

Method of manufacturing an aluminum nitride structure

Method of manufacturing circuit board

A resistor element includes a hollow cylindrical sintered body and a pair of electrodes formed on the upper and lower surfaces of the sintered body. The sintered body contains ferrite as a main constituent and contains 0.05 to 10% by volume of an insulator phase formed at the crystal grain boundary of the ferrite crystals. An insulating layer is formed to cover the side surface of the sintered body. The sintered body contains an oxide material selected from the group consisting of 0.005 to 2.0% by weight of bismuth oxide calculated in terms of Bi.sub.2 O.sub.3, 0.01 to 3.0% by weight and 0.005 to 2.0% by weight of silicon oxide and aluminum oxide calculated in terms of SiO.sub.2 and Al.sub.2 O.sub.3 respectively, and 0.01 to 3.5% by weight and 0.001 to 1.6% by weight of silicon oxide and calcium oxide calculated in terms of SiO.sub.2 and CaO, respectively.

Electrical resistor element and method of manufacturing the same

A light-shielding aluminum nitride sintered body essentially consists of aluminum nitride crystal grains and 0.01 to 1.5 wt % (an element content in the case of a transition metal compound) of homogeneously dispersed transition metal particles and/or transition metal compound particles having an average particle size of 5 .mu.m or less and has a thermal conductivity of 200 W/m.K or more.

Growing community of inventors

Tokyo, Japan

Yoshiko Goto