Light detection device and method for manufacturing light detection device

A method for producing a light detection device, the method comprising:

• a first step of preparing a back-illuminated light receiving element that includes a plurality of light receiving sections arranged one-dimensionally or two-dimensionally, a first main surface in which the light receiving sections are formed, and a second main surface opposite to the first main surface, and is provided with a trench which is open to the first main surface so as to isolate adjacent light receiving sections from each other;
• a second step of disposing the light receiving element on a wiring substrate such that the first main surface of the light receiving element faces the wiring substrate, and electrically and physically connecting a plurality of electrode pads provided on the first main surface and a plurality of electrode pads provided on the wiring substrate;
• a third step of forming a resin mold, which reaches at least a position that is further away from the wiring substrate than an end portion on a second main surface side of the trench in a thickness direction of the wiring substrate, on the wiring substrate so as to surround an entire side surface of the light receiving element;
• and
• a fourth step of polishing the light receiving element and the resin mold from a second main surface side of the light receiving element.