Light detection device

A light detection device comprising:

• a semiconductor light detection element having a semiconductor substrate including first and second principal surfaces opposed to each other;
• and
• a mounting substrate disposed as opposed to the semiconductor light detection element and having a third principal surface opposed to the second principal surface of the semiconductor substrate and a fourth principal surface opposed to the third principal surface,
• wherein the semiconductor light detection element has a photodiode array, the photodiode array including a plurality of avalanche photodiodes operating in Geiger mode and formed in the semiconductor substrate, quenching resistors connected in series to the respective avalanche photodiodes and disposed on the first principal surface side of the semiconductor substrate, and signal lines to which the quenching resistors are connected in parallel and which are disposed on the first principal surface side of the semiconductor substrate,
• wherein the mounting substrate is provided with a first electrode disposed on the third principal surface side,
• wherein the semiconductor substrate is provided with a through-hole electrode electrically connected to the signal lines and penetrating from the first principal surface side to the second principal surface side, and
• wherein the through-hole electrode and the first electrode are electrically connected through a bump electrode, the quenching resistors are electrically connected to the first electrode through the signal lines, the through-hole electrode, and the bump electrode.