Solid-State Image Sensor Shared Wiring for Smaller Bonding Areas
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Solution Overview
Problem
The challenge in solid-state imaging devices is the increase in dead space due to differing wiring pitches between stacked chips, which hinders size reduction and integration, as more wirings require larger bonding areas.
Innovation Solution
A solid-state imaging device with a first substrate featuring a pixel array unit, including first and second wirings, and switching circuits to control the short-circuiting of these wirings, allowing for reduced wiring connections between chips, thereby minimizing dead space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of wirings for transmission and reception between stacked chips is increased, then the signal processing capability is improved, but the dead space around bonding parts increases and chip size reduction is hindered
Solution Approach 1:
The patent combines multiple wiring functions into shared wiring structures. Specifically, the same wiring is used for both signal transmission and reset voltage supply at different time periods, and multiple pixels share common wirings through the switching circuit mechanism, thereby reducing the total number of wirings needed while maintaining full signal processing capability
Solution Approach 2:
The patent introduces time-division multiplexing and switching circuits to dynamically change wiring functions. The switching circuit selectively connects wirings to different functions (signal transmission, reset voltage supply, or short-circuiting) based on operational timing, allowing a single wiring structure to serve multiple purposes that would traditionally require separate dedicated wirings
2Adaptability or versatility
If the wiring pitch is adjusted from small to large around bonding parts, then the wiring compatibility between chips is improved, but the dead space increases
Solution Approach 1:
The patent merges the reset voltage supply function with existing signal transmission wirings. By using the same wiring infrastructure for both purposes through time-division multiplexing, the patent eliminates the need for additional wirings or pitch adjustments that would create dead space around bonding parts
Solution Approach 2:
The patent changes the operational parameters of existing wirings by controlling their electrical state (connected or short-circuited) through switching circuits. This allows the same physical wiring structure to adapt to different functional requirements without requiring physical pitch adjustments or additional space
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 configuration reduces the number of wirings needed between chips, minimizing dead space and enhancing integration and miniaturization of the imaging device.
Implementation Method 1
a pixel array unit in which a plurality of pixels is arranged, each of the plurality of pixels including a photoelectric conversion unit
Data Source
AI summary
To reduce the number of wirings through which transmission and reception are made between chips.The solid-state imaging device includes a first substrate including a pixel array unit in which a plurality of pixels is arranged, each of the plurality of pixels including a photoelectric conversion unit, and the first substrate includes a first wiring through which an imaging pixel signal is transmitted, the imaging pixel signal being read from two or more of the pixels arranged in a first direction in the pixel array unit, a second wiring through which a reset voltage for initializing the first wiring is supplied, and a first switching circuit configured to switch whether or not to short-circuit the first wiring and the second wiring.