Tuning-Fork Piezoelectric Layout for Stable Frequency Measurement
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Solution Overview
Problem
Existing tuning-fork-type piezoelectric vibrating pieces suffer from asymmetrical shapes due to wet etching, leading to unwanted vibrations and reduced reproducibility of frequency measurement.
Innovation Solution
The conductive joining parts are positioned entirely in a biased manner within a specific region of the external joining part, away from the centerline, to dampen unwanted vibrations and improve frequency measurement reproducibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the outer shape of the crystal vibration piece is processed by wet etching, then the manufacturing process is simple and cost-effective, but asymmetrical regions are formed that cause unwanted vibrations and reduce frequency measurement reproducibility
Solution Approach 1:
The patent applies asymmetry by intentionally designing the conductive joining parts to be positioned asymmetrically relative to the virtual centerline of the tuning fork. Specifically, both the first and second conductive joining parts are located entirely in the first region (on one side of the virtual centerline), creating an asymmetric configuration that compensates for the asymmetry introduced by wet etching processes and prevents unwanted vibrations
2Shape
If the conductive joining parts are positioned symmetrically on both sides of the virtual centerline, then the structure appears balanced, but asymmetrical regions from wet etching cause unwanted vibrations that degrade frequency measurement reproducibility
Solution Approach 1:
The patent deliberately introduces asymmetry in the positioning of conductive joining parts to counteract the asymmetry caused by wet etching. By placing both joining parts entirely in the first region rather than symmetrically distributing them, the invention creates a balanced vibration pattern that eliminates spurious vibrations and improves frequency measurement reproducibility
3Measurement precision
If the conductive joining parts are positioned entirely in the first region biasedly, then unwanted vibrations are suppressed and frequency measurement reproducibility is improved, but the device complexity increases due to asymmetric positioning requirements
Solution Approach 1:
The patent applies local quality by specifying that conductive joining parts be positioned in a particular region (the first region) of the external joining part. This localized positioning requirement creates a simple design rule that ensures proper vibration characteristics without requiring complex asymmetric configurations, as both joining parts follow the same positioning guideline
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 suppresses unwanted vibrations, enhances frequency measurement reproducibility, and allows for miniaturization of the piezoelectric vibrating elements and oscillators.
Implementation Method 1
tuning-fork-type piezoelectric vibrating piece having a pair of vibrating arms that vibrate
Data Source
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AI summary
Provided is a tuning-fork-type piezoelectric vibrating piece with which the reproducibility of frequency measurement can be improved. A tuning-fork-type piezoelectric vibrating piece 10 includes a crystal vibration piece 20 having a base part 21, first and second vibrating arms 22 and 23, and an external joining part 24, a pair of first and second excitation electrodes 31 and 32 formed on the first and second vibrating arms 22 and 23, first and second extraction electrodes 33 and 34 extracted from the first and second excitation electrodes 31 and 32 to the base part 21 and the external joining part 24, and first and second conductive joining parts 41 and 42 provided on the first and second extraction electrodes 33 and 34, with the first and second conductive joining parts 41 and 42 being provided so as to be entirely located biasedly only in a first region of the external joining part 24 on the side on which the first vibrating arm 22 is provided with a virtual centerline L1 extending in the extension direction of the first and second vibrating arms 22 and 23 through the center between the first and second vibrating arms 22 and 23 as a reference line.