摘要 |
[Problem] There are provided a ceramic sintered body with superior thermal conductivity as well as high rigidity, a circuit board that does not crack easily, a highly reliable electronic device and a highly reliable thermoelectric conversion module. [Solution] A ceramic sintered body with superior thermal conductivity as well as high rigidity may be obtained by having a main crystalline phase predominantly composed of silicon nitride, and a grain boundary phase predominantly composed of magnesium oxide and rare-earth oxide, the grain boundary phase containing a component which is expressed in compositional formula form as: REMgSi 2 O 5 N, where RE represents rare-earth metal. Furthermore, when the ceramic sintered body is used in a circuit board, the circuit board does not crack easily and a highly reliable circuit board may be formed. An electronic device and thermoelectric conversion module that use this circuit board may be made highly reliable. |