Image Sensor Coating and Ridge Structure for Stray Light Control
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Solution Overview
Problem
Conventional imaging lens assemblies experience image quality degradation due to stray light reflection between components, which affects the image sensor's performance.
Innovation Solution
An image sensor design incorporating an anti-reflection coating with alternating high and low refractive index layers and a ridge-like anti-reflection structure on the light transmitting element and micro lens layer, reducing stray light reflection by maintaining low reflectance across a wide range of wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the micro lens layer is directly disposed on the light transmitting element, then the structure is simple and compact, but stray light reflection is generated between the micro lens layer and light transmitting element which degrades image quality
Solution Approach 1:
An anti-reflection coating layer is introduced as an intermediary between the light transmitting element and micro lens layer. This coating layer with optimized refractive index reduces the reflection coefficient at the interface, allowing light to pass through more efficiently while maintaining the compact structure. The anti-reflection coating acts as a mediator that eliminates the harmful reflection effect without requiring structural separation.
Solution Approach 2:
The refractive index parameter of the interface between light transmitting element and micro lens layer is modified by applying an anti-reflection coating with specific refractive index properties. By changing the optical parameter (refractive index) at the interface, the reflection coefficient is reduced, thereby improving light transmission and image quality while maintaining direct contact structure.
2Object-affected harmful factors
If anti-reflection measures are applied, then stray light reflection is reduced and image quality is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
A thin-film anti-reflection coating is applied to the light transmitting element or micro lens layer. This coating can be deposited using conventional semiconductor fabrication techniques such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), which are成熟 and cost-effective processes. The coating adds minimal complexity while providing effective anti-reflection performance.
Solution Approach 2:
The anti-reflection coating is formed as a composite structure with specific material composition and thickness designed to achieve optimal anti-reflection performance. By using composite material structures with controlled optical properties, effective stray light reduction is achieved while maintaining manufacturing feasibility through standard thin-film deposition processes.
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 effectively minimizes stray light reflection, enhancing image quality and maintaining optical performance while ensuring reliability and stability against external factors.
Implementation Method 1
the anti-reflection coating includes a plurality of high refractive index layers and a plurality of low refractive index layers, which is alternately stacked by the high refractive index layers and the low refractive index layers
Implementation Method 2
The anti-reflection structure includes a plurality of ridge-like protrusions which are non-directionally extended from a disposing surface, wherein a bottom of each of the ridge-like protrusions is closer to the disposing surface than a top of each of the ridge-like protrusions to the disposing surface
Implementation Method 3
The photoelectric conversion layer is for converting a light into an electronic signal
Implementation Method 4
The micro lens layer is disposed above the photoelectric conversion layer for converging the light onto the photoelectric conversion layer
Data Source
AI summary
An image sensor includes an image sensor die, a light transmitting element, at least one anti-reflection coating and at least one anti-reflection structure. The image sensor die includes a photoelectric conversion layer and a micro lens layer. The micro lens layer is disposed above the photoelectric conversion layer for converging the light onto the photoelectric conversion layer. The light transmitting element is disposed above the micro lens layer, and a gap is formed between the light transmitting element and the micro lens layer, the light passes through the light transmitting element and then travels into the image sensor. The anti-reflection coating is at least disposed on an upper surface of the light transmitting element. The anti-reflection structure is disposed on at least one of a lower surface of the light transmitting element and the micro lens layer.