Stacked Light-Receiving Pixel Layout for Higher Charge-Voltage Conversion
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Solution Overview
Problem
Existing imaging devices face challenges in achieving improved conversion efficiency of electric charge into voltage.
Innovation Solution
A light-receiving device comprising a first substrate with photoelectric conversion sections, a second substrate with readout circuits, and a through-electrode coupling the readout circuits, allowing for efficient signal transmission and reduced wiring capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional imaging devices are used, then the structure is simple, but the conversion efficiency of electric charge into voltage is insufficient
Solution Approach 1:
The imaging device is divided into separate substrates: a first substrate containing photoelectric conversion sections and a second substrate containing readout circuits. This segmentation allows optimization of each substrate's function independently, improving conversion efficiency while managing device complexity through modular architecture
Solution Approach 2:
The patent transitions from a planar layout to a three-dimensional stacked configuration where the first substrate and second substrate are bonded together vertically. This dimensional change reduces the distance between photoelectric conversion sections and readout circuits, enhancing conversion efficiency without significantly increasing overall device footprint
2Productivity
If the distance between photoelectric conversion sections and readout circuits is reduced, then conversion efficiency improves, but wiring complexity increases
Solution Approach 1:
The readout circuits are integrated onto the same second substrate, and through-electrodes are used to connect them to the first substrate. This merging approach consolidates the wiring structure and reduces the number of external connections needed, improving conversion efficiency while controlling wiring complexity
Solution Approach 2:
Through-electrodes serve as intermediaries that penetrate the second substrate to establish electrical connections between the readout circuits on the second substrate and the photoelectric conversion sections on the first substrate. This intermediary structure simplifies the wiring architecture by providing direct vertical pathways for signal transmission
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
The solution enhances conversion efficiency by reducing wiring capacitance and shortening the distance between photoelectric conversion sections and readout circuits, leading to improved pixel signal quality.
Implementation Method 1
a first substrate including a plurality of photoelectric conversion sections that photoelectrically converts light
Data Source
AI summary
A light-receiving device according to an embodiment of the present disclosure includes: a first substrate including a plurality of photoelectric conversion sections that photoelectrically converts light; a second substrate including a plurality of readout circuits that outputs a first signal based on electric charge photoelectrically converted by the photoelectric conversion sections; and a first through-electrode coupled to each of the readout circuits and penetrating the second substrate. The first substrate and the second substrate are stacked by bonding between electrodes to allow a first surface of the first substrate on which an element is formed and a second surface of the second substrate on which an element is formed to be opposed to each other. The first through-electrode is provided for each of the readout circuits or for every plurality of readout circuits.