Abstract: Disclosed is an aluminum nitride sintered body which has a high thermal conductivity and a high strength and which can be manufactured through low-temperature, short-time sintering. This aluminum nitride sintered body has an average grain size of aluminum nitride grains of 2 .mu.m or less, a thermal conductivity of 80 W/m.K or more, and a relative density of 98% or more.

Abstract: A compact power circuit breaker having a large breaking capacity and stable breaking performance by using a compact closing resistor unit having high performance. The power circuit breaker includes a main switch arranged in a current path, an auxiliary switch connected to the current path parallel with respect to the main switch and turned on prior to an ON state of the main switch, and a closing resistor unit connected in series with the auxiliary switch and incorporated with a resistor having a sintered body consisting of a Zn--Ti--Co--O--based oxide and having metal components consisting of titanium calculated as titanium oxide (TiO.sub.2) in an amount of 0.5 to 25 mol %, cobalt calculated as cobalt oxide (CoO) in an amount of 0.5 to 30 mol %, and Zn as substantially the balance.

Abstract: 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.

Abstract: 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.

Abstract: According to this invention, there is provided a method of manufacturing a highly reliable circuit board in which a copper member is strongly, directly bonded to a substrate made of an aluminum nitride sintered body, thereby obtaining high peel strength. The method of manufacturing the circuit board includes the steps of bringing a copper member containing 100 to 1,000 ppm of oxygen into contact with an oxide layer having a thickness of 0.1 to 5 .mu.m formed on a surface of a substrate made of an aluminum nitride sintered body, and heating the substrate in an inert gas atmosphere containing 1 to 100 ppm of oxygen at a temperature not more than a temperature corresponding to a liquidus including a pure copper melting point of a hypoeutectic region of a two-component phase diagram of Cu-Cu.sub.

Abstract: According to this invention, there is disclosed a compact power circuit breaker having a large breaking capacity and stable breaking performance due to a compact closing resistor unit having high performance. The power circuit breaker includes a main switching mechanism having an arc extinguishing function, an auxiliary switching mechanism parallelly connected to the main switching mechanism and having an arc extinguishing function, and a closing resistor unit connected in series with the auxiliary switching mechanism and incorporated with a resistor containing zinc oxide (ZnO) as a main component and titanium figured out as titanium oxide (TiO.sub.2) in an amount of 0.5 to 25 mol% and nickel figured out as nickel oxide (NiO) in an amount of 0.5 to 30 mol. % as sub-components.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: According to this invention, there is provided a method of manufacturing a highly reliable circuit board in which a copper member is strongly, directly bonded to a substrate made of an aluminum nitride sintered body, thereby obtaining high peel strength. The method of manufacturing the circuit board includes the steps of bringing a copper member containing 100 to 1,000 ppm of oxygen into contact with an oxide layer having a thickness of 0.1 to 5 .mu.m formed on a surface of a substrate made of an aluminum nitride sintered body, and heating the substrate in an inert gas atmosphere containing 1 to 100 ppm of oxygen at a temperature not more than a temperature corresponding to a liquidus including a pure copper melting point of a hypoeutectic region of a two-component phase diagram of Cu-Cu.sub.

Abstract: 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.

Abstract: There is disclosed an aluminum sintered body prepared by sintering aluminum nitride and additives, which consists essentially of(a) aluminum nitride,(b) at least one compound selected from the group consisting of an aluminum compound of a rare earth metal, an aluminum compound of an alkaline earth metal, and an aluminum compound of a rare earth metal and an alkaline earth metal, and(c) at least one element selected from the transition elements consisting of Groups IVa, Va, VIa, VIIa and VIII of the periodic table, and/or at least one compound comprising the element, and the rare earth element, alkaline earth element and transition element are supplied by the additives.

Abstract: There are disclosed an aluminum sintered body comprising(a) aluminum nitride,(b) at least one compound selected from the group consisting of an aluminum compound of a rare earth metal, an aluminum compound of an alkaline earth metal, and an aluminum compound of a rare earth metal and an alkaline earth metal, and(c) at least one element selected from the transition elements consisting of Groups IVa, Va, VIa, VIIa and VIII of the periodic table, and/or at least one compound containing said element,and a process for preparing the same comprising mixing aluminum nitride with(i) at least one of compound selected from the group consisting of a rare earth metal and/or an alkaline earth metal; and(ii) at least one of element selected from the group consisting of a transition element of Groups IVa, Va, VIa, VIIa and VIII of the periodic table, and/or at least one of a compound containing said element;and then molding and sintering the mixture.

Abstract: A fuzzy logic circuit comprising a current mirror comprising an FET, a first input current source connected to the input side of the current mirror, a second input current source, a wired OR connected at its input side to the output side of the current mirror and to the second input current source, and an output terminal connected to the output side of the wired OR.

Abstract: According to the present invention, there is provided an aluminum nitride sintered body having a high thermal conductivity and essentially consisting of a AlN single-phase, containing 0.01 to 8,000 ppm of rare earth elements and less than 2,000 ppm of oxygen. According to the present invention, there is provided a method of fabricating an aluminum nitride sintered body having a high thermal conductivity and essentially consisting of AlN single-phase, containing 0.01 to 8,000 ppm of rare earth elements and less than 2,000 ppm of oxygen, wherein a molded body prepared by mixing and molding an aluminum nitride power having less than 7 wt % of oxygen and an average particle size of 0.05 to 5 .mu.m and with rare earth compounds of 0.01 to 15 wt % of based on rare earth elements content, or a sintered AlN body containing oxide grain boundary phases of 0.01 to 15 wt % of rare earth elements and 0.

Abstract: For higher thermal conductivity, stronger adhesion strength, excellent insulating characteristics, and multilayer interconnection, an aluminium sintered body for circuit substrates comprises a novel conductive metallized layer on the surface of the sintered body. The metallized layer comprises at least one element selected from the first group of Mo, W and Ta and at least one element selected from the second group of IIa, III, IVa group elements, lanthanide elements, and actinide elements in the periodic table, as the conductive phase element. The first group element serves to improve the heat conductivity and resistance, while the second group serves to increase the wetness and adhesion strength between the insulating body and the metallized layer. Further, the plural insulating ceramic bodies and the plural metallized conductive layers can be sintered simultaneously being stacked one above the other to permit a multilayer interconnection.

Abstract: A fuzzy logic circuit comprising a current mirror comprising an FET, a first input current source connected to the input side of the current mirror, a second input current source, a wired OR connected at its input side to the output side of the current mirror and to the second input current source, and an output terminal connected to the output side of the wired OR.

Abstract: In an information search device for searching for any desired information in a film provided with a series of information frames, frame index marks and document index marks formed along the information frames on the opposite sides thereof, there is provided a drive motor for transporting the film, a light source system for irradiating the film, a photoelectric converter element for detecting the frame index marks, a second photoelectric converter element for detecting the document index marks, a gate circuit for receiving the detection signals from the converter elements to selectively pass one of those detection signals, a counter for counting the detection signals passed through the gate circuit, and a brake mechanism for stopping the transport of the film when the counter has counted up a number of detection signals corresponding to the search number of the desired information.