Ceramic circuit board
AssigneeKabushiki Kaisha Toshiba
InventorsTakayuki Naba, Hiroshi Komorita, Noritaka Nakayama, Kiyoshi Iyogi
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Abstract
The present invention provides a ceramic circuit board comprising: a ceramic substrate and a metal circuit plate bonded to the ceramic substrate through a brazing material layer; wherein the brazing material layer is composed of Al—Si group brazing material and an amount of Si contained in the brazing material is 7 wt % or less. In addition, it is preferable to form a thinned portion, holes, or grooves to outer peripheral portion of the metal circuit plate. According to the above structure of the present invention, there can be provided a ceramic circuit board having both high bonding strength and high heat-cycle resistance, and capable of increasing an operating reliability as electronic device.
Claims28
A ceramic circuit board comprising:
- a ceramic substrate;
- at least one bonding layer that is integrally formed to said ceramic substrate and consists of an Al—Si group brazing material containing 7 wt % or less of Si, or a brazing material containing Al and an alkaline earth metal element or a compound thereof;
- an insulating layer integrally formed to said bonding layer, which prevents the brazing material from being alloyed with a metal circuit plate;
- and
- a metal circuit plate bonded to said ceramic substrate through said insulating layer.
The ceramic circuit board comprising:
- a ceramic substrate;
- a first bonding layer which is integrally formed to said ceramic substrate and consists of a brazing material or alloy mainly composed of Al, wherein said brazing material contains Si in an amount of 7 wt % or less, an alkaline earth metal element, or a compound thereof;
- an insulating layer for preventing the first bonding layer from being alloyed with the metal circuit plate, the insulating layer being integrally formed to said first bonding layer;
- a second bonding layer which is integrally formed to a surface of said insulating layer and consists of a brazing material or alloy mainly composed of Al;
- and
- a metal circuit plate bonded to said ceramic substrate through said second bonding.
Dependencies are inferred from the claim text.