Thermoelectric conversion substrate, thermoelectric conversion module and method for producing thermoelectric conversion substrate

A thermoelectric conversion substrate comprising:

• an insulating substrate having a first surface and a second surface at both sides of the insulating substrate in a thickness direction;
• and
• at least one thermoelectric conversion unit incorporated in the insulating substrate, wherein:
• the at least one thermoelectric conversion unit includes a first thermoelectric member, a second thermoelectric member, and a first electrode disposed on the first surface of the insulating substrate,
• the first thermoelectric member includes a first tubular member having insulation property and a first semiconductor filled in the first tubular member,
• the second thermoelectric member includes a second tubular member having insulation property and a second semiconductor filled in the second tubular member, the second semiconductor having carriers different from carriers of the first semiconductor,
• the first electrode electrically connects the first semiconductor of the first thermoelectric member to the second semiconductor of the second thermoelectric member,
• the first surface of the insulating substrate is spaced apart from each of a first distal end face of the first thermoelectric member and a second distal end face of the second thermoelectric member, the first distal end face and the second distal end face facing the first surface,
• the insulating substrate has, at the first surface, a first opening portion reaching the first distal end face of the first thermoelectric member,
• the insulating substrate has, at the first surface, a second opening portion reaching the second distal end face of the second thermoelectric member,
• an area of the first distal end face of the first thermoelectric member is larger than an area of a bottom surface of the first opening portion,
• an area of the second distal end face of the second thermoelectric member is larger than an area of a bottom surface of the second opening portion, and
• an area of the first opening portion gradually increases from the bottom surface of the first opening portion to the first surface of the insulating substrate.