Multi-layer solid state imaging device

An image pickup device comprising:

• a color separation prism made up of a plurality of prism members, for separating light into a plurality of color components;
• a plurality of solid-state image sensors fixed to the plurality of prism members, respectively;
• a plurality of image sensor boards on which the plurality of solid-state image sensors are mounted, respectively;
• an image control board to which image pickup signals generated by the plurality of image sensor boards, respectively, are inputted;
• and
• a flexible board connected to the image control board, wherein
• the flexible board comprises
• a signal transmission layer which is connected to each of the plurality of image sensor boards and which forms transmission paths for transmitting the image pickup signals to the image control board,
• a heat radiating layer, formed of a high heat conductivity material, which is put into contact with each of the plurality of solid-state image sensors to transfer heat generated in the solid-state image sensors from the image sensors,
• an insulating layer which is placed interveniently between the signal transmission layer and the heat conduction layer to fix the signal transmission layer and the heat conduction layer to each other, and
• a protective layer fixed to surfaces of the signal transmission layer and the heat conduction layer, respectively.