Cooling structure for photoelectric conversion element

1. A cooling mechanism for a surface-mounted-type photoelectric conversion element which has a plurality of signal terminals provided on a back surface of the photoelectric conversion element, and a terminal for fixation at the back surface, wherein the signal terminals are connected to internal wiring of the photoelectric conversion element and the terminal for fixation is not connected to the internal wiring of the photoelectric conversion element, the cooling mechanism comprising:

a front-surface-side copper foil pattern which is provided on a front surface of a circuit board and to which the terminal for fixation is connected, the front surface being located at one side in the thickness direction of the circuit board;

a back-surface-side copper foil pattern which is provided on a back surface of the circuit board, the back surface being located at the other side in the thickness direction of the circuit board;

a through-hole via which connects the front-surface-side copper foil pattern and the back-surface-side copper foil pattern; and

a cooling member which is fixed to the circuit board so as to have contact with the back-surface-side copper foil pattern, and which cools the back-surface-side copper foil pattern.

2. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 1 , wherein the cooling member works as a heat sink which dissipates heat transmitted from the terminal for fixation and through the front-surface-side copper foil pattern, the through-hole via, and the back-surface-side copper foil pattern.

3. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 2 , wherein the cooling member has a Peltier element for cooling the heat sink.

4. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 2 , wherein the circuit board is provided with a through hole at an area where the signal terminal and the terminal for fixation are not disposed,

wherein the heat sink has a protruding portion which penetrates through the through hole, and which has direct contact with the back surface of the photoelectric conversion element or which has contact with the back surface of the photoelectric conversion element via another member.

5. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 1 , the cooling mechanism further comprising a heat transfer member which has contact with a periphery of a front surface of the photoelectric conversion element, and which is fixed to the front-surface-side copper foil pattern to transfer heat from the photoelectric conversion element to the front-surface-side copper foil pattern.

6. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 1 , the cooling mechanism further comprising a housing which accommodates the circuit board and the cooling member in an airtight state,

wherein a heat dissipation surface of the cooling member has contact with the housing.

7. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 1 , wherein the terminal for fixation is provided on a periphery of the back surface of the photoelectric conversion element.

8. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 7 , wherein the front-surface-side copper foil pattern has an exposure area which is located at an outside area relative to a periphery of the photoelectric conversion element in a state in which the photoelectric conversion element is mounted on the circuit board.

9. The cooling mechanism for a surface-mounted-type photoelectric conversion element according to claim 8 , the cooling mechanism further comprising a fixing portion which penetrates through a through hole provided in the exposure area and which fixes the cooling member to the back-surface-side copper foil pattern.