Thin-Film Optical Sensor Encapsulation Against Humidity Degradation
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Solution Overview
Problem
Current optical sensors for detecting optical radiation, especially in the infrared spectral range, face challenges in providing a simple, cost-efficient, and reliable solution for sensing transmissivity, absorption, emission, and reflectance, while also accurately determining the position of objects in space, particularly in terms of depth and width, and are prone to degradation from external influences like humidity and oxygen.
Innovation Solution
An optical sensor comprising a substrate with a layer of photoconductive material and individual electrical contacts, covered by an amorphous metal-containing compound layer that is optically transparent, providing enhanced encapsulation and protection against environmental degradation through atomic layer deposition or a combination of ALD and sputtering processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical sensors are used without advanced encapsulation, then manufacturing is simpler and cost is lower, but the sensors are prone to degradation from external influences like humidity and oxygen
Solution Approach 1:
The patent employs thin film encapsulation layers deposited directly onto the optical sensor surface. These thin films provide environmental protection against humidity and oxygen while maintaining optical transparency and minimizing structural complexity. The thin film approach balances protection needs with device simplicity.
Solution Approach 2:
The patent uses composite encapsulation structures combining multiple materials with complementary properties. The encapsulation layer is designed to provide both environmental barrier functionality and optical transparency, creating a composite structure that addresses multiple requirements simultaneously while managing device complexity.
2Measurement precision
If the cover layer is made optically transparent to allow detection, then detection accuracy is improved, but protection against environmental degradation is reduced
Solution Approach 1:
The patent applies different material properties to different regions or aspects of the encapsulation system. The encapsulation material is selected to provide specific optical transparency in the detection wavelength range while simultaneously providing environmental barrier properties. This local optimization of material properties resolves the contradiction between transparency and protection.
Solution Approach 2:
The patent optimizes the optical and barrier parameters of the encapsulation material. By carefully selecting materials and controlling deposition parameters, the encapsulation layer achieves the right balance between optical transparency (for detection accuracy) and environmental barrier performance (for reliability).
3Reliability
If multiple deposition processes (ALD and sputtering) are combined for encapsulation, then protection performance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines ALD and sputtering deposition processes in a hybrid encapsulation approach. Each process complements the other, with ALD providing conformal coverage and chemical stability, while sputtering offers robust physical barrier properties. This merging of processes achieves superior protection performance while managing manufacturing complexity through process integration.
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 offers improved long-term stability and reliability for optical sensors, enabling efficient detection of optical radiation and accurate position determination with reduced susceptibility to humidity and oxygen, while maintaining cost-effectiveness and ease of integration.
Implementation Method 1
a layer of at least one photoconductive material which is directly or indirectly applied to the substrate
Implementation Method 2
a cover covering accessible surfaces of the layer of the photoconductive material and of the substrate, wherein the cover is an amorphous cover which comprises at least one metal-containing compound
Implementation Method 3
providing enhanced encapsulation and protection against environmental degradation through atomic layer deposition or a combination of ALD and sputtering processes
Implementation Method 4
providing enhanced encapsulation and protection against environmental degradation through atomic layer deposition or a combination of ALD and sputtering processes
Data Source
AI summary
Described herein is an optical sensor, a detector including the optical sensor for an optical detection of at least one object, a method for manufacturing the optical sensor and various uses of the optical detector.The optical sensor can be supplied as a non-bulky hermetic package which provides an increased degree of protection against possible degradation by humidity and/or oxygen over long terms. Further, the optical sensor may be easily manufactured and integrated on a circuit carrier device.