Ceramic substrate and ceramic divided substrate

Abstract

A ceramic substrate is provided with a flat plate-shaped insulating base composed of a ceramic, a first brazing material layer provided on a first main surface of the insulating base, second brazing material layer provided on a second main surface of the insulating base, a circuit plate composed of a metal and fixed through the first brazing material layer to the insulating base on a first main surface-side, and a heat dissipation plate composed of a metal and fixed through the second brazing material layer to the insulating base on a second main surface-side. A thickness of one of the heat dissipation plate and the circuit plate is larger than a thickness of the other. When the thickness of the heat dissipation plate is larger than the thickness of the circuit plate, a thickness of the first brazing material layer is larger than a thickness of the second brazing material layer. When the thickness of the circuit plate is larger than the thickness of the heat dissipation plate, the thickness of the second brazing material layer is larger than the thickness of the first brazing material layer.

Dependencies are inferred from the claim text.