Integrated Pixel Temperature Sensing for SiPM Breakdown Voltage Correction

Solution Overview

Problem

Photodetection devices, such as SiPMs, exhibit high temperature dependence in photon detection efficiency due to variations in breakdown voltage, leading to inaccurate temperature correction and increased size and power consumption when using external temperature monitors.

Innovation Solution

Incorporating a temperature detecting circuit with a photodiode of the same structure as the avalanche photodiode within each pixel, using a light shielding structure to prevent light interference, and applying a voltage control mechanism to correct the drive voltage based on temperature-dependent breakdown voltage variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a temperature monitoring chip is used to correct temperature dependence of photon detection efficiency, then temperature correction can be performed, but the device size and power consumption increase

Engineering Contradiction:

Improvetemperature correction accuracyVSAvoiddevice size

Core Design Contradiction:

Measurement precisionVSWeight of stationary object

Solution Approach 1:

The temperature monitoring function is merged with the photodetection element itself. The patent integrates a temperature monitoring circuit directly into the photodetection chip, eliminating the need for separate external temperature monitoring chips. This integration maintains temperature correction capability while reducing overall device size and component count.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The photodetection chip is designed to perform multiple functions: both photodetection and temperature monitoring. By incorporating temperature sensing capabilities into the same chip that performs photon detection, the device achieves multi-functionality, thereby eliminating the need for separate dedicated temperature monitoring components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If a temperature monitoring chip is used to correct temperature dependence of photon detection efficiency, then temperature correction can be performed, but power consumption increases

Engineering Contradiction:

Improvetemperature correction accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The temperature monitoring function is merged with the photodetection element itself. The patent integrates a temperature monitoring circuit directly into the photodetection chip, eliminating the need for separate external temperature monitoring chips. This integration maintains temperature correction capability while reducing overall device size and component count.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The photodetection chip is designed to perform multiple functions: both photodetection and temperature monitoring. By incorporating temperature sensing capabilities into the same chip that performs photon detection, the device achieves multi-functionality, thereby eliminating the need for separate dedicated temperature monitoring components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If a temperature monitor formed with a different chip is used, then temperature monitoring is implemented, but temperature correction accuracy decreases due to poor reproduction of actual device temperature

Engineering Contradiction:

Improvetemperature monitoring implementationVSAvoidtemperature correction accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The temperature monitoring function is merged with the photodetection element itself. The patent integrates a temperature monitoring circuit directly into the photodetection chip, eliminating the need for separate external temperature monitoring chips. This integration maintains temperature correction capability while reducing overall device size and component count.

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces temperature variation in photon detection efficiency, improves temperature correction accuracy, and minimizes device size and power consumption by integrating temperature monitoring directly within the photodetection device.

Implementation Method 1

a temperature detecting circuit including a temperature detecting element configured to detect a temperature of the pixel

Methodology Applied

Scientific EffectTemperature-dependent electrical characteristics: Electrical Resistance

Implementation Method 2

a light shielding structure disposed on an upper surface of the photodiode

Methodology Applied

Scientific EffectLight blocking: Absorption (EM radiation)

Implementation Method 3

photon detection efficiency (also called PDE) has a high temperature dependence

Methodology Applied

Scientific EffectPhotoelectric conversion: Photoelectric Effect

Implementation Method 4

an avalanche photodiode and a resistor connected in series to the avalanche photodiode

Methodology Applied

Scientific EffectAvalanche multiplication: Avalanche Breakdown

Data Source

PatentUS10401218B2Photodetection device and object detection system using said photodetection device

Publication Date: 2019.09.03 KK TOSHIBA

AI summary

An photodetection device according to an embodiment includes: a pixel including at least one cell, the at least one cell including an avalanche photodiode and a resistor connected in series to the avalanche photodiode; a voltage source configured to apply voltage to the cell of the pixel; and a temperature detecting circuit including a temperature detecting element configured to detect a temperature of the pixel, wherein the temperature detecting element includes: a photodiode having the same structure as the avalanche photodiode; and a light shielding structure disposed on an upper surface of the photodiode.