Gas Sensor Substrate Thermal Resistance Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas sensors face challenges in maintaining detection accuracy due to heat transfer issues between the infrared light emitting element and the microphone element, leading to thermal expansion and distortion, which reduces the accuracy of sound wave detection.
Innovation Solution
A sensor device with a substrate configuration that increases the thermal resistance of the heat transfer path between the accommodation recessed portions for the microphone and infrared light emitting elements, either by extending the distance between them or using low heat conduction materials, to suppress heat transfer and minimize thermal distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the infrared light emitting element and microphone element are disposed close to each other on the substrate, then the device size is reduced, but heat transfer from the infrared light emitting element to the microphone element increases causing thermal expansion and detection accuracy degradation
Solution Approach 1:
The substrate is divided into distinct regions with different thermal conductivity characteristics. A first region with high thermal conductivity is positioned between the infrared light emitting element and the microphone element to conduct heat away from the microphone element, while a second region with low thermal conductivity isolates the microphone element from direct heat transfer paths. This segmentation allows close positioning of components while maintaining detection accuracy through controlled thermal management.
Solution Approach 2:
Different regions of the substrate are assigned different thermal conductivity properties to meet local thermal management requirements. The first region adjacent to the infrared light emitting element has high thermal conductivity to rapidly conduct generated heat away, while the second region surrounding the microphone element has low thermal conductivity to protect it from thermal interference. This local differentiation of material properties resolves the contradiction between compact size and detection precision.
2Illumination intensity
If the infrared light emitting element operates at high power, then the infrared light intensity for gas detection is improved, but the heat generated causes thermal expansion of the microphone element and reduces detection accuracy
Solution Approach 1:
The substrate with its differentiated thermal conductivity regions acts as an intermediary thermal management system. The first high thermal conductivity region serves as a heat sink that intercepts and conducts away heat from the infrared light emitting element before it can reach the microphone element. This intermediary structure enables the infrared light emitting element to operate at high power for strong detection signals while the microphone element remains thermally isolated for accurate gas detection.
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 heating of the microphone element, thereby enhancing detection accuracy and preventing a decrease in sound wave detection precision.
Implementation Method 1
thermal resistance of a heat transfer path between a bottom surface of a first accommodation recessed portion for accommodating a microphone element and a bottom surface of a second accommodation recessed portion for accommodating an infrared light emitting element is greater than thermal resistance at any position of an imaginal heat transfer path
Implementation Method 2
an infrared light source element is accommodated in one recessed portion... infrared light emitted from the infrared light source element... The substance to be detected is excited by infrared light
Implementation Method 3
a generated sound wave is detected by the microphone... an acoustic wave generator and an acoustic wave detector
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
The present invention relates to a sensor wiring substrate in which a decrease in detection accuracy is suppressed, a sensor package, and a sensor device. A gas sensor wiring substrate 1 includes a substrate 2 having a first accommodation recessed portion 2a for accommodating a microphone element 20 and a second accommodation recessed portion 2b for accommodating an infrared light emitting element 21, and connection wiring 3. In the gas sensor wiring substrate 1, thermal resistance of a heat transfer path between a bottom surface of the first accommodation recessed portion 2a and a bottom surface 2b of the second accommodation recessed portion is greater than thermal resistance in any position of an imaginal heat transfer path in case of a depth of the first accommodation recessed portion 2a identical with a depth of the second accommodation recessed portion 2b. For example, the depth of the second accommodation recessed portion 2b is deeper than the depth of the first accommodation recessed portion 2a.