Infrared Microbolometer Holding Arms Lateral Encapsulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing infrared imaging microbolometers face challenges in using high-performance materials for holding arms due to the etching process of the sacrificial layer, which deteriorates sensitive materials and limits performance.
Innovation Solution
The integration of a lateral encapsulation layer resistant to hydrofluoric acid etching protects the materials in the holding arms, allowing the use of higher-performance materials for improved electric resistivity, thermal resistance, and mechanical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional etching methods are used to remove the sacrificial layer, then the sacrificial layer can be removed, but high-performance materials in the holding arms are deteriorated
Solution Approach 1:
A protective layer is introduced as an intermediary between the sacrificial layer and the holding arms. This protective layer resists the hydrofluoric acid etching process, thereby protecting the holding arms materials from deterioration while still allowing the sacrificial layer to be removed. The protective layer acts as a mediator that enables the etching process to proceed without directly harming the sensitive holding arms materials.
2Reliability
If the surface area of electrodes is increased to optimize infrared radiation absorption, then infrared absorption is improved, but the electrodes are more exposed to etching damage
Solution Approach 1:
The protective layer serves as a mediator that allows the electrodes to have increased surface area for infrared absorption without direct exposure to etching damage. The protective layer is positioned between the etching environment and the electrodes, enabling the electrodes to extend further and absorb more infrared radiation while remaining protected from chemical deterioration.
3Reliability
If high-performance materials are used in the holding arms to improve electric resistivity and thermal resistance, then detector performance is improved, but the materials are more vulnerable to etching damage
Solution Approach 1:
The protective layer is introduced as a mediator that enables the use of high-performance materials in the holding arms by shielding them from etching damage. These materials can achieve superior electric resistivity and thermal resistance properties while the protective layer prevents the hydrofluoric acid etching from deteriorating them, thus resolving the contradiction between performance and vulnerability.
Solution Approach 2:
The protective layer creates an inert environment around the holding arms materials, shielding them from the harmful hydrofluoric acid etching process. This inert barrier allows the high-performance materials to maintain their properties without chemical degradation, enabling the use of materials that would otherwise be too vulnerable to etching damage.
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 solution enables the use of high-performance materials in the holding arms, enhancing the microbolometer's performance by reducing heat conductance and improving infrared radiation collection while maintaining mechanical integrity.
Implementation Method 1
said lateral encapsulation layer being resistant to etching based on hydrofluoric acid
Implementation Method 2
means for absorbing the thermal radiation and for converting it into heat
Implementation Method 3
detection of infrared radiation
Implementation Method 4
thermometry means which, in the context of a microbolometric detector, implement a resistive element having its resistance varying along with temperature
Implementation Method 5
this physical quantity is the electric resistivity, but other quantities may be used, such as the dielectric constant, the biasing, the thermal expansion
Implementation Method 6
means for thermally insulating the detector, in such a way as to enable it to heat under the action of the thermal radiation
Data Source
AI summary
This infrared imaging microbolometer integrates a membrane mounted in suspension above a substrate by means of holding arms attached to anchor nails. The microbolometer includes a support layer extending within the membrane holding arms and electrodes arranged on the support layer and in contact with the anchor nails. Each electrode extends within a holding arm. A thermoresistive material is arranged within the membrane in electric contact with the electrodes. The microbolometer also includes at least an upper encapsulation layer for the holding arms and the thermoresistive material and a lateral encapsulation layer for the holding arms arranged in contact with the lateral edges of said holding arms, the lateral encapsulation layer being resistant to etching based on hydrofluoric acid.