Murata Manufacturing Co., Ltd.

Hideyuki Harada

Hirofumi Sunahara

Hiromichi Kawakami

A method for manufacturing multilayer ceramic substrates in accordance with a multiple formation method using a non-shrinkage process allows the multilayer ceramic substrates to be smoothly formed by dividing a sintered multilayer mother substrate, and in addition, external terminal electrodes in a preferable state can be efficiently formed. When a green composite laminate comprising shrinkage suppression layers and a green multilayer mother substrate provided therebetween is formed, through-holes are provided on dividing lines so as to divide conductors, and in addition, cut-in grooves are provided along the dividing lines. After the shrinkage suppression layers are removed from the fired composite laminate, the multilayer ceramic substrates are obtained by dividing the multilayer mother substrate along the through-holes and the cut-in grooves. Conductors, which are formed into the external terminal electrodes, are exposed on parts of side surfaces of the multilayer ceramic substrate corresponding to parts of the inside surfaces of the through-holes.

Method for manufacturing multilayer ceramic substrates

A method for fabricating a multilayer ceramic substrate having a cavity with multi-steps therein for mounting an electronic component is provided. A block is inserted into a lower cavity segment of the cavity formed in a green sheet laminate to be the multilayer ceramic substrate, wherein the block has substantially the same three-dimensional shape as that of the cavity segment and has a height equal to or larger than the depth of the cavity segment. Thus, the pressing step is performed in a state such that the cavity has an apparent single step.

Method for producing multilayer ceramic substrate

In a ceramic green-sheet stack to be fired to form a multilayered ceramic substrate having a cavity, a shrinkage-reducing pad is formed along a boundary interface between first ceramic green sheets having an opening for defining a cavity, and second ceramic green sheets having no opening. The shrinkage-reducing pad is exposed on the entire periphery of the inner peripheral surface of the cavity at the bottom end of the inner peripheral surface. The shrinkage-reducing pad contains a glass component, and serves to reduce shrinkage stress produced at the boundary interface between the first and second ceramic green sheets during the firing process.

Multilayered ceramic substrate and production method therefor

A green sheet stack having a cavity is produced, and a shrinkage-reducing sheet containing inorganic powder material, which is not fired in a step of firing the green sheet stack, is prepared. The shrinkage-reducing sheet is placed so as to close an aperture of the cavity and to cover an end face in the sheet-stacking direction of the green sheet stack. The green sheet stack is pressed via an elastic member in the sheet-stacking direction so that the shrinkage-reducing sheet is cut and a shrinkage-reducing sheet piece formed of a cut portion of the shrinkage-reducing sheet is placed on a bottom surface of the cavity. The green sheet stack is fired in such a state in which the shrinkage-reducing sheet piece is placed on the bottom surface of the cavity.

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Omihachiman, Japan

Hideyuki Harada