Multilayered ceramic substrate and production method therefor
AssigneeMurata Manufacturing Co., Ltd.
InventorsHideyuki Harada, Hirofumi Sunahara
Life of this patent
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Abstract
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.
Claims12
A method for producing multilayered ceramic substrate having a cavity comprising the steps of:
- providing a first ceramic green sheet having an opening for forming a cavity, and a second ceramic green sheet having no opening at a position corresponding to said opening of the first ceramic green sheet;
- providing a first shrinkage-reducing material for reducing shrinkage stress produced at a boundary between said first ceramic green sheet and said second ceramic green sheet;
- forming a green-sheet stack having a cavity defined by said opening by stacking said first ceramic green sheet, said second ceramic green sheet and said first shrinkage-reducing material so that an aperture of said cavity is disposed on at least one end face of said stacked ceramic green sheets in a sheet-stacking direction and extends through a depth of said stack to an inner peripheral surface while positioning a shrinkage-reducing layer comprising said first shrinkage-reducing material along said boundary between said first ceramic green sheet and said second ceramic green sheet but less than the entire surface of the second green sheet at the position corresponding to said opening of the first ceramic green sheet so that said shrinkage-reducing layer is exposed at an end of said inner peripheral surface of said cavity;
- and
- firing said green-sheet stack.
A method for producing multilayered ceramic substrate having a cavity comprising the steps of:
- providing a first ceramic green sheet having an opening for forming a cavity, and a second ceramic green sheet having no opening at a position corresponding to said opening of the first ceramic green sheet;
- providing a first shrinkage-reducing material for reducing shrinkage stress produced at s boundary between said first ceramic green sheet and said second ceramic green sheet;
- forming a green-sheet stack having a cavity defined by said opening by stacking said first ceramic green sheet, said second ceramic green sheet and said first shrinkage-reducing material so that an aperture of said cavity is disposed on at least one end face of said stacked ceramic green sheets in a sheet-stacking direction and extends through a depth of said stack to an inner peripheral surface while positioning a shrinkage-reducing pad comprising said first shrinkage-reducing material along said boundary between said first ceramic green sheet and said second ceramic green sheet so that said shrinkage-reducing pad is exposed at the entire periphery of said inner peripheral surface of said cavity;
- and
- firing said green-sheet stack,
- wherein said shrinkage-reducing pad comprises a glass component, and the softening temperature of said glass component is less than or equal to the shrinkage starting temperature of said first and second ceramic green sheets.
Dependencies are inferred from the claim text.