Getter-Sealed Resonator Cavity for Stable Vacuum and Q-Value
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Resonator devices face issues with loss of vacuum and deterioration in vibration characteristics due to residual gas and fluctuations in vibrational frequency, leading to a decrease in Q-value.
Innovation Solution
A resonator device configuration featuring an element substrate with a frame part, a resonator element, and substrates with bonding layers and a getter layer with gas adsorptive properties, which adsorbs residual gas to maintain a vacuum state and stabilize vibration characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If airtight sealing is performed using bonding members to seal the cavity, then the sealing performance is improved, but residual gas remains in the cavity causing vacuum loss and deterioration in vibration characteristics
Solution Approach 1:
A getter layer is formed on the second substrate before bonding to the element substrate. This preliminary action ensures that the gas adsorptive function is already in place before the cavity is sealed, allowing the getter layer to effectively adsorb residual gas molecules that remain after airtight sealing, thereby preventing vacuum deterioration and maintaining stable vibration characteristics.
Solution Approach 2:
The getter layer acts as an intermediary substance between the residual gas and the sealed cavity environment. It mediates the harmful effect of residual gas by adsorbing gas molecules, thus protecting the resonator element from vacuum loss and frequency fluctuations without interfering with the airtight sealing structure.
2Duration of action of stationary object
If the cavity is sealed airtightly to maintain vacuum, then vacuum state is preserved initially, but vacuum deterioration occurs over time due to residual gas
Solution Approach 1:
The getter layer is prepared in advance on the second substrate before bonding, ensuring that gas adsorption capability is established before the cavity is sealed. This preliminary preparation allows the getter layer to continuously adsorb residual gas over time, maintaining vacuum state and preventing long-term deterioration in vibration characteristics such as Q-value and frequency stability.
Solution Approach 2:
The getter layer provides continuous gas adsorption functionality within the sealed cavity. Unlike one-time vacuum pumping, the getter layer continuously adsorbs residual gas molecules over the operational lifetime of the device, maintaining the vacuum state and ensuring continuous stability of vibration characteristics without requiring external intervention.
3Strength
If bonding layers are used to connect substrates, then structural integrity is improved, but the complexity of manufacturing processes increases
Solution Approach 1:
The getter layer and the second substrate are integrated into a single structure, with the getter layer formed directly on the second substrate. This merging eliminates the need for separate getter installation steps and reduces the number of discrete components, thereby simplifying the manufacturing process while maintaining strong bonding through the bonding layer between the element substrate and the combined second substrate-getter structure.
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 vacuum deterioration and maintains stable vibration characteristics by adsorbing residual gas, thereby enhancing the long-term performance of the resonator device.
Implementation Method 1
a getter layer which is arranged on the fourth surface, exposed to the housing part, and has a gas adsorptive property
Data Source
AI summary
A resonator device includes an element substrate including a frame part having a first surface and a second surface in a front-back relationship with each other, and a resonator element which is coupled to the frame part, and is arranged inside the frame part, a first substrate which is arranged at the first surface side, and has a third surface faced to the first surface, a first bonding layer which is arranged between the element substrate and the first substrate, and which is configured to bond the first surface and the third surface to each other, a second substrate which is arranged at the second surface side, and has a fourth surface faced to the second surface, a second bonding layer which is arranged between the element substrate and the second substrate, and which is configured to bond the second surface and the fourth surface to each other, a housing part which is surrounded by the frame part, the first substrate, and the second substrate, and which houses the resonator element, and a getter layer which is arranged on the fourth surface, exposed to the housing part, and has a gas adsorptive property.