Detection Element Warping Control via Porous Support Structure
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Solution Overview
Problem
Detection elements that receive infrared or terahertz waves are prone to warping due to thermal stress caused by temperature rises during high-temperature environments or manufacturing processes, leading to potential damage from accidental contact with substrates.
Innovation Solution
A detection element design featuring an absorption layer that generates heat upon receiving electromagnetic waves, a thermoelectric element to convert heat into current, and a support structure with a specific accommodation space configuration. The support structure includes a first accommodation opening for incident waves and a second accommodation opening on the opposite side, where the absorption layer exposed through the second opening has a smaller area than the first opening, allowing controlled warping away from the substrate as temperature rises.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a stress-relaxing structure part with multiple holes is provided in the infrared sensor, then thermal stress concentration is relaxed, but the structural strength is reduced
Solution Approach 1:
The support is designed with through holes forming a porous structure that relieves thermal stress concentration while maintaining sufficient structural strength. The porous configuration allows stress diffusion without requiring complete solid structure, thus balancing stress relaxation and strength requirements.
Solution Approach 2:
The detection element employs a composite structure combining the absorption layer, support with through holes, and optional protective layer. This composite design allows each layer to contribute specific properties - the support provides stress relaxation through its porous composite structure while maintaining overall structural integrity.
2Stability of the object's composition
If a stress-relaxing layer is formed on the substrate, then substrate warpage is reduced, but the heat capacity increases which is disadvantageous for the time constant
Solution Approach 1:
The support is designed as a thin-film structure with through holes that provides stress relaxation and warpage control without adding significant mass. The thin-film nature ensures minimal heat capacity increase while maintaining the ability to reduce substrate warpage through controlled flexibility and stress distribution.
Solution Approach 2:
The porous structure with through holes in the support reduces the amount of material present, thereby minimizing heat capacity increase while still providing sufficient stress relaxation and warpage control functions.
3Stress or pressure
If the absorption layer is fully exposed through the support, then stress relaxation is maximized, but the risk of accidental contact with substrate increases
Solution Approach 1:
The support structure implements local quality variation through strategically positioned through holes rather than uniform exposure. This allows stress relaxation to occur at specific locations where holes are provided while maintaining coverage in other areas to prevent accidental contact between the absorption layer and substrate.
Solution Approach 2:
The support is segmented into regions with through holes and regions without, creating a patterned structure that provides stress relaxation where needed while maintaining protective coverage in other areas. This segmentation allows simultaneous achievement of stress relaxation and contact prevention.
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 effectively reduces the risk of accidental contact between the absorption layer and the substrate, minimizes warpage, and maintains a low heat capacity and time constant, enhancing the detection element's performance and durability.
Implementation Method 1
an absorption layer configured to receive an electromagnetic wave included in at least a part of a wavelength range from 100 μm to 3000 μm to generate heat
Implementation Method 2
a thermoelectric element configured to generate current corresponding to the heat generated by the absorption layer
Implementation Method 3
the absorption layer exposed through the second accommodation opening has an area smaller than the first accommodation opening does... allowing controlled warping away from the substrate as temperature rises
Data Source
AI summary
To provide an advantageous feature for reducing the effects of warping attributable to thermal stress in a detection element capable of receiving electromagnetic waves (infrared and/or terahertz waves). The detection element includes an absorption layer configured to receive an electromagnetic wave included in at least a part of a wavelength range from 100 μm to 3000 μm to generate heat, a thermoelectric element configured to generate current corresponding to the heat generated by the absorption layer, and a support having an accommodation space in which the absorption layer is positioned. The accommodation space has a first accommodation opening located on a side on which the electromagnetic wave is incident and a second accommodation opening located on an opposite side to the first accommodation opening. The absorption layer exposed through the second accommodation opening has an area smaller than the first accommodation opening does.