Ngk Insulators, Inc.

Seiko Epson Corporation

Katsuyuki Takeuchi

Yukihisa Takeuchi

Tsutomu Nanataki

Hideo Masumori

Hisanori Yamamoto

Natsumi Shimogawa

Shuichi Ozawa

Takuji Kimura

Koichi Iwata

Takahiro Maeda

Yukio Aisaka

A layered inductor is manufactured by layering 'silver-based conductive layers' and 'ferrite-based magnetic layers' and simultaneously firing these layers. The conductive layers are via-connected to form a helical coil. A shape of a cross sectional surface of the conductive layer, cut by a plane perpendicular to a longitudinal direction of each of the conductive layers is a substantial trapezoid shape, having an upper base and a lower base. A base angle &#x3b8; of the trapezoid shape at both ends of the lower base is equal to or greater than 50&#xb0; and is smaller than or equal to 80&#xb0;.

Layered inductor

A method for controlling the shrinkage of ceramic formed bodies is provided, including performing a preliminary test to determine an average shrinkage of ceramic formed bodies made from test lots of a ceramic powder, and determining a linear correlation between the average shrinkage and measured amounts of the ground test lots removed from a ball mill during a specific milling time interval. A batch of the ceramic powder is then ground, an amount of the ground ceramic powder removed from the ball mill during the specific time interval is measured, and the linear correlation is used to estimate the shrinkage of a ceramic body made therefrom. The difference between a target shrinkage and the estimated shrinkage is determined, and one or more of the processing conditions used to form the ceramic body are changed to offset the difference.

Method for controlling shrinkage of formed ceramic body

A ceramic diaphragm structure includes a ceramic substrate having at least one window portion, and a thin ceramic diaphragm plate laminated so as to cover the window portion, wherein the ceramic diaphragm structure is unitarily formed so that the thin ceramic diaphragm portion is protruded in the direction opposite to the window portion, and a ceramic connecting layer connects the thin ceramic diaphragm plate to the ceramic substrate. The ceramic diaphragm structure has a high resonance frequency, an enhanced strength, an excellent quality and a high reliability.

Ceramic diaphragm structure and method for producing the same

Provided are a method for producing ceramic green sheets used for making a ceramic substrate which is reduced in cracking failure and improved in adhesion between laminated layers and is high in lamination property, high in strength and excellent in surface roughness, said method including heat-treating the ceramic powder having a specific particle size by dry grinding a ceramic powder to prepare ceramic powder having a specific average degree of aggregation and preparing a slurry using the ceramic powder so that a green density of the resulting ceramic green sheets is in a desired range, and a method for making a ceramic laminated substrate having excellent various properties by laminating the above ceramic green sheets and firing the laminate.

Method for producing ceramic green sheet

A method for forming a ceramic diaphragm structure includes providing a laminate of a ceramic green substrate having at least one window and a plurality of layers, and a thin ceramic green sheet superimposed on the ceramic green substrate to cover the at least one window. The laminate is fired so that the ceramic green sheet provides a diaphragm portion protruding in a direction away from the at least one window, and the fired laminate is subjected to a second firing step under load.

Method for producing a ceramic diaphragm structure

A zirconia diaphragm structure, and a method of producing such structure. The zirconia diaphragm structure includes a zirconia substrate having at least one window, and a zirconia diaphragm plate formed integrally with the zirconia substrate so as to close each window, the zirconia substrate comprising a zirconia material as a major component, and containing 0.1-3.0% by weight of alumina, 0.1-3.0% by weight of silica, 0.1-5.0% by weight of alumina and silica, 0.1-5.0% by weight of alumina and magnesia, or 0.1-5.0% by weight of alumina, silica and magnesia.

Method of producing a zirconia diaphragm structure

A method of controlling the amount of firing shrinkage of a ceramic green body prepared by molding a ceramic powder (A) to a desired value A.sub.1 by heat treating the powder at a temperature T.sub.1 that provides the firing shrinkage A.sub.1 at a predetermined firing temperature. The temperature T.sub.1 is determined based on an established correlation between an amount of firing shrinkage at the predetermined firing temperature and a heat-treatment temperature of a powder (B) having a composition similar to that of the powder (A) in such an extent that a total amount of a greatest common content of an individual component common between the powders (A) and (B) in terms of percent is 90% by weight or more, and satisfying such a relation that the spherical diameter of powder (A) is within a range of .+-. 30% relative to the spherical diameter (Rs) of the powder (B) and that its average degree of aggregation (x) is within the range from 1/2 fold to 2 fold relative to the average degree of aggregation (x) of the powder (B).

Method for controlling firing shrinkage of ceramic green body

A method for producing a ceramic diaphragm structure includes preparing a ceramic green substrate having at least one window and a plurality of layers, and a thin ceramic green sheet. The ceramic green sheet is superposed on the ceramic green substrate to cover the window and thereby provide a unitary laminate. The laminate is then fired so that the ceramic green sheet provides a diaphragm portion which protrudes in a direction away from the window. The average sintering temperature difference or the average shrinkage-rate difference, of the layers of the ceramic green substrate, is larger than zero.

Method for producing ceramic diaphragm structure

A zirconia diaphragm structure, and a method of producing such structure in which the zirconia diaphragm structure includes a zirconia substrate having at least one window, and a zirconia diaphragm plate formed integrally with the zirconia substrate so as to close each window, the zirconia substrate comprising a zirconia material as a major component, and containing 0.1-3.0% by weight of alumina, 0.1-3.0% by weight of silica, 0.1-5.0% by weight of alumina and silica, 0.1-5.0% by weight of alumina and magnesia, or 0.1-5.0% by weight of alumina, silica and magnesia.

Zirconia diaphragm structure and piezoelectric/electrostrictive film

A method of producing a ceramic diaphragm structure, including a ceramic substrate having at least one window, and a ceramic diaphragm plate superposed on the ceramic substrate to close the window or windows. The method includes the steps of: firing the diaphragm plate with the ceramic substrate to form an integral sintered body, such that the diaphragm plate provides at least one diaphragm portion aligned with the window or windows; protruding each diaphragm portion outwards, in a direction away from the corresponding window, so that the diaphragm portion is formed into a convex shape; and controlling the amount of protrusion of the diaphragm portion, by pressing a jig having a flat surface or a concave surface, against a top part of the diaphragm portion having the convex shape, so that at least the top part has a flat surface or a curved surface having a predetermined radius of curvature.

Method of producing ceramic diaphragm structure having convex diaphragm

The present invention provides a method for controlling a firing shrinkage of a ceramic green body. The method includes the steps of: subjecting a ceramic powder to a pretreatment by which a spherical diameter (Rs) of the ceramic powder is adjusted to be 1 .mu.m or less, wherein Rs is expressed by an equation of Rs(.mu.m)=6/.rho. S (.rho. is a true density (g/cm.sup.3) of the ceramic powder, and S is a BET specific surface area (m.sup.2 /s) of the ceramic powder.); subjecting the ceramic powder to heat treatment at a specific temperature calculated in advance; molding the ceramic powder to obtain a ceramic green body; and firing the ceramic green body. A temperature for the heat-treatment is calculated of the basis of a correlation between calculative rates for firing and arbitrary selected temperatures.

A zirconia diaphragm structure, and a method of producing such structure. The zirconia diaphragm structure includes a zirconia substrate having at least one window, and a zirconia diaphragm plate formed integrally with the zirconia substrate so as to close each window, the zirconia substrate comprising a zirconia material as a major component, and containing 0.1-5.0% by weight of one of combinations consisting of (i) alumina and calcia, (ii) alumina, calcia and magnesia, (iii) alumina, calcia and silica, and (iv) alumina, calcia, magnesia and silica.

Zirconia diaphragm structure, method of producing the same, and

A ceramic diaphragm structure which includes a ceramic substrate having at least one window, and a ceramic diaphragm plate which is superposed on the ceramic substrate so as to close the window or windows. The diaphragm plate is fired with the ceramic substrate to form an integral sintered body. The diaphragm plate includes at least one diaphragm portion which is/are aligned with the window(s), respectively, and each diaphragm portion protrudes outwards, in a direction away from the corresponding window, to form a convex shape. Also disclosed is a method of protuding such a ceramic diaphragm structure, in which the diaphragm portion is formed into convex shape, upon firing of the ceramic substrate and ceramic diaphragm plate.

Growing community of inventors

Nagoya, Japan

Katsuyuki Takeuchi