Piezoelectric Acceleration Sensor Metallic Sheet Support
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Solution Overview
Problem
Existing piezoelectric acceleration sensors fail to achieve high output sensitivity while maintaining a reduced size, and previous support structures either require complex processes or cannot be tested until production is complete.
Innovation Solution
A piezoelectric acceleration sensor design featuring a piezoelectric element, a metallic sheet, and a circuit board with a U-like shape, where the piezoelectric element is polarized and supported by the circuit board and metallic sheet in a both-ends support structure, allowing for high output sensitivity and improved mass productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a bending-type piezoelectric acceleration sensor is used with conventional support structures, then the structure is simple and price is reduced, but the output sensitivity is limited to about a few mV/G
Solution Approach 1:
The invention transitions from direct support of piezoelectric ceramics to supporting a metallic sheet that in turn supports the piezoelectric element. This dimensional change in the support structure allows for enhanced sensitivity while maintaining manufacturing simplicity.
Solution Approach 2:
A metallic sheet is introduced as an intermediary between the circuit board and the piezoelectric element. This intermediary component amplifies the bending effect, enabling higher output sensitivity (100 mV/G or more) without complicating the overall structure or manufacturing process.
2Productivity
If piezoelectric ceramics is installed in storage case using conventional support structures, then production is simplified, but performance testing cannot be done until production is almost complete
Solution Approach 1:
The support structure is segmented into distinct components: circuit board, metallic sheet, and piezoelectric element. This segmentation allows for independent assembly and testing of the piezoelectric element before final integration into the storage case, enabling performance testing at earlier production stages.
Solution Approach 2:
The metallic sheet is pre-attached to the circuit board with the piezoelectric element positioned on it, creating a testable assembly before final storage case integration. This preliminary arrangement enables performance testing to occur during the assembly process rather than after complete production.
3Measurement precision
If the piezoelectric vibrator is supported in both-ends support structure with complex polarization, then output sensitivity is improved, but complicated processes are required to polarize the piezoelectric vibrator
Solution Approach 1:
The invention uses a simple metallic sheet support structure that replaces the need for complex polarization processes. The metallic sheet provides the necessary mechanical support and sensitivity enhancement without requiring elaborate polarization treatments, simplifying the manufacturing process.
Solution Approach 2:
The invention changes the support mechanism from direct piezoelectric element support to metallic sheet support, fundamentally altering the mechanical parameters of the system. This parameter change enables high output sensitivity through the metallic sheet's bending characteristics rather than through complex polarization of the piezoelectric material.
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 design achieves superior output sensitivity and reduced size, with simplified manufacturing processes and the ability to perform performance tests before assembly, enhancing productivity and sensitivity.
Implementation Method 1
a piezoelectric acceleration sensor, which uses bending of a piezoelectric ceramics
Data Source
AI summary
A piezoelectric acceleration sensor comprises a piezoelectric element, a metallic sheet and a circuit board. The piezoelectric element is polarized in a predetermined direction. The circuit board includes a circuit portion and a roughly flat shaped base portion. The base portion protrudes from an end portion of the circuit portion. One of surfaces of the metallic sheet is fixed to and supported by a surface of the base portion. The piezoelectric element is fixed to and supported by a remaining one of the surfaces of the metallic sheet in a manner that the piezoelectric element and the base portion do not overlap each other in the predetermined direction.