Ceramic structure

A ceramic structure comprising:

• a ceramic base member having a main face, the ceramic base member defining a hole extending from the main face into the ceramic base member;
• a metal electrode layer embedded in the ceramic base member;
• a conductive member embedded in the ceramic base member so as to be electrically connected to the metal electrode layer, the conductive member forming a bottom of the hole;
• a first metal member joined to the conductive member by a brazing material, the first metal member having a first front surface that is opposed to the conductive member and a first back surface that is opposite to the first front surface, and the first metal member having an average linear expansion coefficient not less than an average linear expansion coefficient of the conductive member;
• one or more second metal members disposed at the first back surface of the first metal member, each of the one or more second metal members having a greater average linear expansion coefficient than the average linear expansion coefficient of the first metal member;
• and
• a metal terminal at least partially located in the hole and joined to the one or more second metal members, the metal terminal having a greater average linear expansion coefficient than the average linear expansion coefficient of each of the one or more second metal members,
• wherein a distance between the conductive member and the metal terminal is not less than 1.5 mm, and a ratio of a thickness of the first metal member and a thickness of the one or more second metal members is less than 4.