Quartz Resonator Coating for Dual-Order Temperature Compensation
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Solution Overview
Problem
Current temperature-compensated resonators, such as those used in quartz watches, require complex corrections for second-order frequency drift, especially for COSC certification, which involves temperature measurements and electronic adjustments.
Innovation Solution
A temperature-compensated resonator with a quartz crystal core and a coating that has opposite sign variations for first and second-order temperature-dependent Young's modulus, allowing for compensation of both orders with a single coating, optimizing the cut angle and thickness to achieve zero temperature coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single coating is used to compensate for both first and second order temperature coefficients, then the device complexity is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies composite materials by depositing a coating layer (such as silicon dioxide, germanium dioxide, or synthetic diamond) on the quartz crystal core. This coating has opposite sign temperature-dependent variations of Young's modulus compared to the quartz crystal, allowing simultaneous compensation of both first and second order temperature coefficients. The composite structure of quartz core plus functional coating achieves dual-order temperature compensation while maintaining relatively simple device architecture.
Solution Approach 2:
The patent utilizes parameter changes by carefully selecting the coating thickness and material properties to achieve precise compensation. The coating thickness is optimized based on the desired compensation characteristics, and the material's temperature-dependent Young's modulus parameters are selected to counterbalance the quartz crystal's temperature drift. This parameter optimization allows a single coating to compensate for both first and second order temperature coefficients.
2Stability of the object's composition
If the cut angle of the quartz crystal is optimized to achieve zero temperature coefficients, then the temperature stability is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent applies parameter changes by optimizing the cut angle of the quartz crystal plate to achieve zero first and second order temperature coefficients. Specific cut angles are selected based on the desired temperature compensation characteristics, and these angular parameters are precisely controlled during crystal cutting. This parameter optimization enables the quartz crystal to inherently compensate for temperature drift when combined with the appropriate coating.
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 results in a resonator that is insensitive to temperature variations, simplifying the correction process and enhancing the stability of time or frequency bases, such as in timepieces, by eliminating the need for complex electronic corrections.
Implementation Method 1
the body includes a coating, which is at least partially deposited on the core and has first and second order temperature dependent variations of the Young's modulus of opposite signs respectively to said first and second order temperature coefficients of said resonator so that the latter are rendered substantially zero
Data Source
AI summary
A temperature-compensated resonator includes a body used in deformation, wherein the core (58, 58′, 18) of the body (3, 5, 7, 15, 23, 25, 27, 33, 35, 37, 43, 45, 47) is formed from a plate formed at a cut angle (θ′) in a quartz crystal determining the first and second orders temperature coefficients (α, β, α′, β′). According to the invention, the body (3, 5, 7, 15, 23, 25, 27, 33, 35, 37, 43, 45, 47) includes a coating (52, 54, 56, 52′, 54′, 56′, 16) deposited at least partially on the core (58, 58′, 18) and having first and second orders Young's modulus variations (CTE1, CTE2, CTE1′, CTE2′) according to temperature of opposite signs respectively to the first and second orders temperature coefficients (α, β, α′, β′) of the resonator so as to render compensated first and second orders temperature coefficients substantially zero.