Sensor Module Compensation Element for Thermal Stress
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Solution Overview
Problem
Existing sensor modules face issues with thermal decoupling between the housing and substrate, leading to exposure of sensitive regions to environmental influences like contamination, mechanical damage, and electromagnetic radiation, due to differing thermal expansion coefficients between plastic housings and metal substrates, resulting in reduced robustness and accuracy.
Innovation Solution
A compensation element is placed between the housing and substrate, which is essentially flat and parallel to the substrate's main plane, compensating for thermomechanical stress and protecting the sensor module from environmental influences by having a different thermal expansion coefficient, thus preventing arching and enhancing robustness and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a molded housing made of plastic and a leadframe made of metal are used to achieve cost-effective production, then manufacturing cost is reduced, but thermal expansion differences cause thermomechanical stress and arching of the housing
Solution Approach 1:
The patent introduces a compensation element with specifically selected thermomechanical properties (thermal expansion coefficient, modulus of elasticity, thickness) to counterbalance the thermomechanical stress generated by the plastic housing and metal substrate combination. By changing the parameters of the compensation element, the system achieves stress compensation while maintaining the cost-effective material combination.
Solution Approach 2:
The patent creates a composite structure consisting of the plastic housing, metal substrate, and compensation element (typically metal). This composite construction allows the system to combine the advantages of different materials (cost-effectiveness of plastic, electrical properties of metal) while compensating for their disadvantages (thermal expansion mismatch) through the carefully designed compensation element.
2Temperature
If the sensitive region of the sensor element is positioned outside the housing to achieve thermal decoupling, then thermal stability is improved, but the sensitive region becomes exposed to environmental influences such as contamination and mechanical damage
Solution Approach 1:
The patent positions the compensation element on the housing in such a way that it extends over and protects the sensor element's sensitive region. The compensation element acts as a protective cover that shields the exposed sensitive area from environmental influences while allowing the sensor to remain thermally decoupled from the housing.
Solution Approach 2:
The compensation element serves a dual function as both a thermomechanical stress compensator and a protective intermediary between the environment and the sensor element. It mediates between the need for thermal decoupling (exposing the sensor) and the need for protection (covering the sensor).
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 prevents thermal deformations and protects the sensor module from contamination, mechanical damage, and electromagnetic radiation, while maintaining planarity over a wide temperature range, thereby increasing the robustness and accuracy of micromechanical components.
Implementation Method 1
A compensation element is placed between the housing and substrate, which is essentially flat and parallel to the substrate's main plane, compensating for thermomechanical stress and protecting the sensor module from environmental influences by having a different thermal expansion coefficient
Implementation Method 2
The compensation element may include a metal, so that electromagnetic screening of the sensor element on the first side is implemented by the compensation element
Data Source
AI summary
A sensor module is provided having a sensor element, a housing and a substrate, the sensor element being situated on the substrate and the sensor element is provided to be at least partially embedded in the housing; and the sensor module further having a compensation element for compensating for thermal deformations of the housing; the housing being essentially situated between the substrate and the compensation element.