Tdk Corporation

Haruo Nishino

Kiyoshi Hatanaka

Kenji Endou

Hideaki Ninomiya

Masaharu Hirakawa

Hideaki Fujioka

A multilayer ceramic substrate includes a plurality of ceramic layers laminated each other. The plurality of ceramic layers form a bulge and a cavity having such a shape that an opening area of the cavity gradually becomes smaller toward a bottom of the cavity.

Multilayer ceramic substrate

A multilayer ceramic substrate having a cavity is formed by the steps of laminating a plurality of ceramic green sheets including ceramic green sheets having through holes corresponding to the cavity to form a multilayer body, pressing the multilayer body and firing the pressed body. At this time, a shrinkage suppression green sheet is laminated on the surface of the a ceramic green sheet constituting the outermost layer of the multilayer body, and a shrinkage suppression green sheet piece is disposed on the ceramic green sheet exposed to the bottom of the cavity in accordance with the shape of the cavity. A burnable sheet is further disposed on the shrinkage suppression green sheet piece. Before the pressing step, an embedded green sheet separate from the ceramic green sheets (portion separated by inserting a cut) is disposed on the shrinkage suppression green sheet piece or the burnable sheet so that it is filled in the cavity. After the firing step, the embedded green sheet fired is removed.

Production method of a multilayer ceramic substrate

An object of the invention is to connect different dielectrics electrically to each other in the direction of main surface of a sheet in a multilayer ceramic substrate and to increase the degree of flexibility in design and make the multilayer ceramic substrate compact in size. A multilayer ceramic substrate in accordance with the invention is formed of a plurality of laminated ceramic substrates including such a composite ceramic substrate of different materials that is made by inserting the second ceramic substrate in a pounched-out portion made in the first ceramic substrate and by planarizing its top and bottom surfaces, wherein a conductive layer is formed in a portion across a boundary between the first ceramic substrate and the second ceramic substrate of the interface of the composite ceramic substrate of different materials.

Production method for a multilayer ceramic substrate

A method for producing a multilayer ceramic substrate having a cavity formed therein includes punching a through opening corresponding to the cavity in green sheets constituting a laminate, and printing a conductor at a predetermined position of the green sheets, laminating the green sheets to constitute a green sheet laminate, and applying a pressure to the green sheet laminate by using a compression member having a projection at a position corresponding to the cavity to thereby compress the green sheet laminate. The projection has a height which is equal to the depth of the cavity multiplied by compression ratio of the green sheet laminate, and the green sheet laminate is compressed by applying the pressure such that compression ratio of the bottom of the cavity is identical with the compression ratio of other parts of the green sheet laminate.

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Tokyo, Japan

Haruo Nishino