Stacked Image Sensor Bond Layout to Reduce Shading
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Solution Overview
Problem
Existing photoelectric conversion apparatuses lack an optimal arrangement of metal bonding portions between stacked chips, which affects the apparatus's performance and efficiency in image sensing and other applications.
Innovation Solution
A photoelectric conversion apparatus with a specific arrangement of metal bonding portions between first and second semiconductor element layers, where the number and pattern of metal bonding portions are optimized to improve the connection and reduce interconnection resistance, allowing for better image capture and reduced shading effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If metal bonding portions are arranged in a conventional uniform pattern between stacked chips, then the structure is simple and easy to manufacture, but the interconnection resistance is high and image quality deteriorates due to shading effects
Solution Approach 1:
The patent applies asymmetry by arranging metal bonding portions in different patterns for different pixel blocks. Specifically, first pixel blocks have metal bonding portions arranged at different positions compared to second pixel blocks, creating an asymmetric overall arrangement that reduces shading effects and interconnection resistance variations across the image sensor array.
Solution Approach 2:
The patent implements local quality by optimizing the arrangement of metal bonding portions according to different regions of the pixel array. Different pixel blocks (first and second pixel blocks) have differently arranged metal bonding portions tailored to their specific locations, ensuring optimal electrical connection and minimal shading effects for each local region rather than using a uniform global pattern.
2Reliability
If the number of metal bonding portions is increased to reduce interconnection resistance, then image quality improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies segmentation by dividing the pixel array into multiple pixel blocks (first pixel blocks and second pixel blocks) with different metal bonding arrangements. This segmentation allows the system to achieve reliable connections through distributed bonding portions across multiple blocks rather than requiring a single complex bonding pattern, improving manufacturability while maintaining connection reliability.
Data Source
AI summary
A photoelectric conversion apparatus includes a first chip including a first semiconductor element layer and a second chip including a second semiconductor element layer, the first chip and the second chip are bonded by a plurality of metal bonding portions between the first semiconductor element layer and the second semiconductor element layer, the plurality of pixel circuits includes a first pixel block including n (n is an integer of 3 or more) pixel circuits, and a second pixel block, the plurality of metal bonding portions includes a first metal bonding portion connecting the first semiconductor element layer and the second semiconductor element layer, and the number of the first metal bonding portions arranged at positions overlapping the first pixel block in a planar view is smaller than the number of the first metal bonding portions arranged at positions overlapping the second pixel block in a planar view.