Resonator Vibration Arm Structure for Compact Frequency Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resonance devices face challenges in reducing size due to increased height when adjusting resonant frequency, as collisions between the vibration arm and the upper cover are absorbed by a metal film, limiting the device's compactness.
Innovation Solution
A resonance device design featuring a resonator with a vibration part, a holding part, and a supporting arm, where the tip-end portion of the vibration arm includes a silicon surface facing the bottom plate, allowing for frequency adjustment by exciting the resonator to contact the bottom plate, thereby reducing size without increasing height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the gap between the tip-end part of the vibration arm and the upper cover is increased to avoid collision, then the collision impact is avoided, but the upper cover height increases
Solution Approach 1:
The invention applies different surface materials to different regions of the vibration arm. The base-end-side portion has a metal film surface that can absorb collision impact, while the tip-end-side portion has a silicon surface that maintains precise gap control. This local differentiation allows the device to tolerate small collisions at the base region while maintaining reliable operation at the tip region, resolving the contradiction between collision avoidance and height reduction.
2Adaptability or versatility
If the resonant frequency is adjusted by collision between the vibration arm and the upper cover, then the frequency can be tuned, but the metal film absorbs the impact reducing adjustment effectiveness
Solution Approach 1:
The invention creates a localized silicon surface at the tip-end-side portion of the vibration arm that is specifically designed for frequency adjustment through controlled contact with the upper cover. This silicon region provides a hard, precise contact surface that enables effective frequency tuning without the energy absorption characteristics of the metal film, thereby maintaining adjustment effectiveness while enabling frequency adaptability.
3Length of stationary object
If the vibration arm structure is optimized to reduce device size, then the device becomes more compact, but the height reduction may limit frequency adjustment range
Solution Approach 1:
The invention maintains a reduced overall device height by using the silicon surface at the tip-end-side portion for frequency adjustment, as this region provides efficient contact with the upper cover. The metal film at the base-end-side portion continues to provide impact absorption capability. This localized material differentiation enables frequency adjustment functionality to be maintained within a compact height profile, resolving the contradiction between size reduction and adjustment range.
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 a reduced size resonance device by optimizing the vibration arm structure to minimize height while maintaining effective frequency adjustment, enhancing compactness without compromising performance.
Implementation Method 1
The vibration arm is configured to perform out-of-plane bending vibration
Implementation Method 2
an impact caused by collision between the vibration arm and the upper cover can be absorbed by the metal film
Data Source
AI summary
A resonance device includes: a resonator and a first substrate. The resonator includes a vibration part, a frame disposed at at least a portion of a circumference of the vibration part, and a supporting arm configured to connect the vibration part and the frame. The first substrate includes a first bottom plate configured to have a first gap to the vibration part in a thickness direction. The vibration part includes a vibration arm configured to perform out-of-plane bending vibration. The vibration arm includes a tip-end part with a base-end-side portion and a tip-end-side portion that is closer to an open-end side of the vibration arm than the base-end-side portion, the base-end-side portion has a first surface that includes a metal film facing the first bottom plate, the tip-end-side portion has a second surface that includes silicon facing the first bottom plate.