MEMS Microphone Actuator for Self-Calibration
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Solution Overview
Problem
Current methods for testing microphone elements are inadequate as they fail to effectively account for the influence of packaging and connection technology on performance, leading to high testing costs and insufficient evaluation of component parts, especially at the wafer level.
Innovation Solution
Incorporating a selectively actuable actuator component that generates defined pressure pulses to test the sensor diaphragm, allowing for functional testing and self-calibration, with the actuator component being independently actuated and analyzed to separate its functions from the sensor component, enabling low-cost and authentic testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If final acoustics measurement is performed at the end of production to check compliance with specifications, then the influence of packaging and connection technology on microphone performance is accounted for, but the testing costs represent a significant portion of the total cost of the component part
Solution Approach 1:
The testing process is segmented into two distinct stages: wafer-level testing of individual components (MEMS and ASIC) and final acoustics measurement of the complete packaged microphone. This segmentation allows cost-effective electrical testing at the wafer level while preserving the necessary final acoustics measurement for complete system evaluation, thereby reducing overall testing costs while maintaining measurement precision.
Solution Approach 2:
Electrical functionality testing of the MEMS and ASIC components is performed preliminarily at the wafer level before packaging. This preliminary action identifies and eliminates defective components early in the production process, reducing the number of units that require expensive final acoustics measurement and thereby lowering overall testing costs while maintaining quality assurance.
2Ease of manufacture
If wafer-level testing is performed to check operativeness of MEMS and ASIC elements, then testing costs are reduced, but the influence of packaging and connection technology on microphone performance is not sufficiently evaluated
Solution Approach 1:
The testing process is segmented into two distinct stages: wafer-level testing of individual components (MEMS and ASIC) and final acoustics measurement of the complete packaged microphone. This segmentation allows cost-effective electrical testing at the wafer level while preserving the necessary final acoustics measurement for complete system evaluation, thereby reducing overall testing costs while maintaining measurement precision.
3Ease of operation
If the sensor diaphragm is actively deflected during testing, then the testing process is simplified, but the test results do not reflect authentic operating conditions
Solution Approach 1:
An actuator component is introduced as an intermediary element that generates authentic pressure signals (such as sound waves or pressure pulses) to excite the sensor diaphragm during testing. This intermediary allows the diaphragm to be stimulated in the same manner as during actual operation, ensuring that test results reflect authentic operating conditions while maintaining an automated and controlled testing process.
4Device complexity
If component functions are integrated rather than separated, then device complexity is reduced, but fault susceptibility increases
Solution Approach 1:
The component part is segmented into functionally independent modules: the sensor component (MEMS with sensor diaphragm and ASIC for signal acquisition and analysis) and the actuator component (for generating test pressure signals). This functional segmentation isolates faults to specific modules, reducing overall fault susceptibility while maintaining manageable device complexity through clear separation of concerns.
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 approach reduces testing costs by allowing separate final testing of each component part, provides meaningful test results under authentic conditions, and enhances fault susceptibility by clearly separating component functions, enabling continuous calibration and adjustment of sensor properties across the component's service life.
Implementation Method 1
at least one selectively actuable actuator component for generating defined pressure pulses that act on the sensor diaphragm
Implementation Method 2
at least one MEMS element having a pressure-sensitive sensor diaphragm and a switching arrangement for detecting the diaphragm deflections as measuring signals
Data Source
AI summary
Measures are described which simplify the functional testing of a component having an MEMS element provided with a pressure-sensitive sensor diaphragm, and which allow a self-calibration of the component even after it is already in place, i.e., following the end of the production process. The component has a housing, in which are situated at least one MEMS element having a pressure-sensitive sensor diaphragm and a switching arrangement for detecting the diaphragm deflections as measuring signals; an arrangement for analyzing the measuring signals; and an arrangement for the defined excitation of the sensor diaphragm. The housing has at least one pressure connection port. The arrangement for exciting the sensor diaphragm includes at least one selectively actuable actuator component for generating defined pressure pulses that act on the sensor diaphragm.