Optical Sensor Light Collimating Layer Asymmetric Pillar Design
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Solution Overview
Problem
Existing optical sensors face challenges in increasing the aspect ratio of light collimators due to process capability limitations, leading to deformation and collapse of transparent pillars, which affects collimating results and yield.
Innovation Solution
The optical sensor employs a layered structure with first and second transparent pillars and light-shielding layers, where the top surface area of each first transparent pillar is not equal to the bottom surface area of each second transparent pillar, preventing misalignment and deformation by forming the light collimating layer in a layered manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the aspect ratio of transparent pillars is increased to improve collimating efficiency, then the collimating performance is improved, but the transparent pillars deform and collapse due to process capability limitations
Solution Approach 1:
The patent divides the single high aspect ratio transparent pillar into multiple stacked transparent pillar structures with different cross-sectional areas. This segmentation reduces the height of each individual transparent pillar while maintaining the overall collimating efficiency, preventing deformation and collapse that would occur with a single tall pillar.
Solution Approach 2:
The patent employs a nested structure where multiple transparent pillars are stacked vertically with smaller cross-sectional areas at higher levels. This nested arrangement allows the structure to achieve high overall aspect ratio while each individual pillar segment remains within process capability limits, preventing structural failure.
2Illumination intensity
If the aspect ratio of transparent pillars is increased to improve collimating efficiency, then the collimating performance is improved, but the production yield decreases due to deformation and collapse
Solution Approach 1:
By segmenting the transparent pillar structure into multiple stacked segments, the patent enables manufacturing within existing process capabilities, thereby maintaining high production yield while achieving the desired collimating efficiency through the cumulative effect of multiple segments.
Solution Approach 2:
The patent changes the cross-sectional area parameter of transparent pillars along the vertical direction, with smaller areas at higher levels. This parameter variation allows each segment to be manufactured within process limits while the overall structure achieves high aspect ratio and collimating efficiency, improving both yield and performance.
3Illumination intensity
If transparent pillars are made taller to achieve high aspect ratio, then collimating efficiency is improved, but misalignment occurs between stacked pillars
Solution Approach 1:
The patent employs asymmetric cross-sectional areas for stacked transparent pillars, with smaller areas at higher levels. This asymmetric design provides better alignment tolerance and reduces misalignment issues between stacked pillars, while maintaining the overall high aspect ratio needed for collimating efficiency.
Solution Approach 2:
The patent addresses alignment issues by introducing dimensional variation in the cross-sectional area of transparent pillars along the vertical axis. This dimensional change creates staggered or offset patterns that compensate for alignment errors, ensuring optimal light collimation despite manufacturing variations.
Data Source
AI summary
An optical sensor includes pixels disposed in a substrate and a light collimating layer disposed on the substrate. The light collimating layer includes a first light-shielding layer, first transparent pillars, a second light-shielding layer, and second transparent pillars. The first light-shielding layer is disposed on the substrate. The first transparent pillars through the first light-shielding layer are correspondingly disposed on the pixels. The second light-shielding layer is disposed on the first light-shielding layer and the first transparent pillars. The second transparent pillars through the second light-shielding layer are correspondingly disposed on the first transparent pillars. The top surface area of each of the first transparent pillars is not equal to the bottom surface area of each of the second transparent pillars.