A ceramic sheet has at least one ceramic layer. The at least one ceramic layer includes a plurality of ceramic pieces, at least a part of the plurality of ceramic pieces is formed by cracking a sintered ceramic plate, which at least partially has a flat part, at the flat part of the sintered ceramic plate.

A ceramic sheet has at least one ceramic layer. The at least one ceramic layer includes a plurality of ceramic pieces, at least a part of the plurality of ceramic pieces is formed by cracking a sintered ceramic plate, which at least partially has a flat part, at the flat part of the sintered ceramic plate.

Carbon-Keramik-Bremsscheiben, die mehrere Schichten umfassen, wobei mindestens eine Schicht als Tragkörper dient und mindestens eine Schicht als Reibschicht fungiert, wobei der Tragkörper und mindestens eine Reibschicht durch eine Zwischenschicht getrennt sind, dadurch gekennzeichnet, daß die Zwischenschicht Verstärkungsfasern in Form von Faserbündeln aufweist, wobei die Faserbündel von einer Schicht aus einer Mischung von Siliciumcarbid, Silicium und Kohlenstoff umgeben sind, die durch thermische Behandlung einer Mischung aus Silicium-Pulver und einem carbonisierten Harz oder carbonisierten Pech bei einer Temperatur von 900 °C bis 1700 °C unter Ausschluß von Oxydationsmitteln erhältlich ist, Verfahren zu deren Herstellung, und Verwendung insbesondere in Bremssystemen von Automobilen

A paste of active metallic brazing material (2) is applied to the entire surface of each side of aluminum nitride or alumina ceramic substrate (1); circuit forming copper plate (3) having a thickness of 0.3 mm is placed in contact with one surface of the substrate and a heat dissipating copper plate (4) having a thickness of 0.25 mm placed in contact with the other surface; the individual members are compressed together and heated at 850°C in a vacuum furnace to form a joint; an etching resist is applied to the circuit forming copper plate and etching is performed with an iron chloride solution to form a circuit pattern and the unwanted brazing material (2) is removed from the marginal portions; a second resist layer is applied and etched with an iron chloride solution to form a second marginal step; a third resist layer is similarly applied and etched to form a third marginal step; the completed circuit board having three marginal steps of which the lowest one is solely or partly made of the brazing material (2) can withstand 1,500 heat cycles, which is the result that has been unattainable by the prior art. Having such high heat cycle characteristics, the circuit board is suitable for use as semiconductor substrate in automobiles, electric trains and other applications that require high output power.

This invention provides a silicon nitride circuit board in which a metal circuit plate is bonded to a high thermal conductive silicon nitride substrate having a thermal conductivity of not less than 60 W/m K, wherein a thickness D_S of the high thermal conductive silicon nitride substrate and a thickness D_M of the metal circuit plate satisfy a relational formula D_S ≦ 2D_M. The silicon nitride circuit board is characterized in that, when a load acts on the central portion of the circuit board which is held at a support interval of 50 mm, a maximum deflection is not less than 0.6 mm until the silicon nitride substrate is broken. The silicon nitride circuit board is characterized in that, when an anti-breaking test is performed to the circuit board which is held at a support interval of 50 mm, an anti-breaking strength is not less than 500 MPa. The metal circuit plate or a circuit layer are integrally bonded on the silicon nitride substrate by a direct bonding method, an active metal brazing method, or an metalize method. According to the silicon nitride circuit board with the above arrangement, high thermal conductivity and excellent heat radiation characteristics can be obtained, and heat cycle resistance characteristics can be considerably improved.

This invention provides a silicon nitride circuit board in which a metal circuit plate is bonded to a high thermal conductive silicon nitride substrate having a thermal conductivity of not less than 60 W/m K, wherein a thickness D_S of the high thermal conductive silicon nitride substrate and a thickness D_M of the metal circuit plate satisfy a relational formula ${\text{D}}_{\text{S}}{\text{≦ 2D}}_{\text{M}}$. The silicon nitride circuit board is characterized in that, when a load acts on the central portion of the circuit board which is held at a support interval of 50 mm, a maximum deflection is not less than 0.6 mm until the silicon nitride substrate is broken. The silicon nitride circuit board is characterized in that, when an anti-breaking test is performed to the circuit board which is held at a support interval of 50 mm, an anti-breaking strength is not less than 500 MPa. The metal circuit plate or a circuit layer are integrally bonded on the silicon nitride substrate by a direct bonding method, an active metal brazing method, or an metalize method. According to the silicon nitride circuit board with the above arrangement, high thermal conductivity and excellent heat radiation characteristics can be obtained, and heat cycle resistance characteristics can be considerably improved.

A paste of active metallic brazing material is applied to the entire surface of each side of aluminum nitride or alumina ceramic substrate 1; circuit forming copper plate 3 having a thickness of 0.3 mm is placed in contact with one surface of the substrate and a heat dissipating copper plate 4 having a thickness of 0.25 mm placed in contact with the other surface; the individual members are compressed together and heated at 850°C in a vacuum furnace to form a joint; an etching resist is applied to the circuit forming copper plate and etching is performed with an iron chloride solution to form a circuit pattern and the unwanted brazing material is removed from the marginal portions; a second resist layer is applied and etched with an iron chloride solution to form a second marginal step; a third resist layer is similarly applied and etched to form a third marginal step; the completed circuit board having three marginal steps of which the lowest one is solely or partly made of the brazing material can withstand 1,500 heat cycles, which is the result that has ben unattainable by the prior art. Having such high heat cycle characteristics, the circuit board is suitable for use as semiconductor substrate in automobiles, electric trains and other applications that require high output power.

A method of producing a fired pattern by firing a firing pattern bonded to an object via an inorganic powder sheet formed by binding inorganic powders of glass, ceramic, etc., with the use of a resin binder, wherein said sheet is bonded to said object by applying heat and/or pressure thereto or with the use of a pressure-sensitive adhesive.