Infrared detection device

An infrared detecting device comprising:

• an infrared detecting element including a semiconductor substrate in which a plurality of pixels are two-dimensionally arranged;
• a signal processing board including a plurality of signal processing circuits configured to process signals output from the plurality of pixels, the signal processing board being disposed to oppose the semiconductor substrate;
• and
• a heat-conducting layer disposed in the signal processing board, wherein
• the signal processing board includes an element placement area where the infrared detecting element is placed, and a circuit placement area positioned outside the element placement area to surround the element placement area when viewed from a direction orthogonal to the signal processing board, and includes a plurality of insulating layers stacked on a surface side opposing the semiconductor substrate,
• in the element placement area, a plurality of electrodes electrically connected to a corresponding pixel of the plurality of pixels are arranged,
• the plurality of signal processing circuits are placed only in the circuit placement area to surround the element placement area, each signal processing circuit being electrically connected to a corresponding electrode of the plurality of electrodes though a conductive line,
• the signal processing board is configured to output a signal output from the pixel to the signal processing circuit though the electrode and conductive line corresponding the pixel, and
• the heat-conducting layer is placed to be positioned on at least one of the plurality of insulating layers and in the element placement area, and has a heat conductivity that is higher than a heat conductivity of the plurality of insulating layers.