Dual-Angle Quartz Crystal Cutting for Wide-Temperature Resonators
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Solution Overview
Problem
Conventional quartz crystal resonators, such as those cut using the AT-cut method, exhibit significant vibration frequency deviations beyond the ±20 ppm range when operating across extreme temperatures from −40° C. to 125° C., making them unsuitable for applications requiring precise frequency stability in diverse environmental conditions.
Innovation Solution
A novel cutting method for quartz crystal resonators involves rotating a quartz bar with specific angles to create a cutting plane, where the first angle is between 35° to 36° relative to the light axis and the second angle is between 10° to 12° relative to the electrical axis, ensuring the quartz crystal maintains a vibration frequency deviation within ±20 ppm across the temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional AT-cut method is used to cut quartz crystal, then the manufacturing process is simple and well-established, but the vibration frequency deviation exceeds ±20 ppm in extreme temperature ranges from -40°C to 125°C
Solution Approach 1:
The patent changes the cutting parameters from conventional AT-cut angles to a novel dual-angle configuration: first angle between 35°-36° relative to the light axis, and second angle between 10°-12° relative to the electrical axis. This parameter modification enables the quartz crystal to maintain vibration frequency deviation within ±20 ppm across the extreme temperature range of -40°C to 125°C, resolving the frequency stability issue while providing clear manufacturing guidelines.
2Reliability
If the cutting angles are adjusted to improve temperature tolerance, then the frequency stability improves, but the manufacturing complexity increases due to additional rotation steps
Solution Approach 1:
The patent segments the cutting process into two distinct rotational steps: first rotating the quartz bar around the light axis by angle α (35°-36°), then rotating around the electrical axis by angle β (10°-12°). This segmentation allows each rotation to be precisely controlled and measured independently, making the complex dual-angle cutting process manageable and repeatable in manufacturing while achieving superior temperature tolerance.
3Measurement precision
If precise dual-angle cutting is implemented, then vibration frequency deviation is reduced to within ±20 ppm, but the manufacturing time and process difficulty increase
Solution Approach 1:
The patent establishes preliminary action by pre-defining the optimal angle ranges (α: 35°-36°, β: 10°-12°) through research and development. These predetermined parameters can be directly programmed into automated cutting equipment, allowing manufacturers to achieve precise frequency deviation control within ±20 ppm without requiring complex real-time adjustments, thereby improving manufacturing efficiency while maintaining high precision.
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 method results in a quartz crystal resonator with improved temperature tolerance, maintaining precise frequency stability from −40° C. to 125° C., meeting stricter industrial standards and enabling reliable performance in extreme environments.
Implementation Method 1
a quartz crystal resonator includes a quartz crystal cut from a quartz bar... such that the quartz crystal has a vibration frequency deviation inflection point from about 30 degrees Celsius to about 45 degrees Celsius
Data Source
AI summary
A quartz crystal resonator including a quartz crystal obtained from a quartz bar is provided. The quartz bar has a light axis, an electrical axis along a length of the quartz bar, and a mechanical axis that are perpendicular to one another. The quartz crystal has a major face cut from the quartz bar along a cutting plane. The cutting plane has a first angle of about 35° to about 36° with the light axis and has a second angle with the electric axis. The first angle is obtained by rotation about the electric axis, and the second angle is obtained by rotation about the light axis, such that the quartz crystal has a vibration frequency deviation inflection point in a range from about 30° C. to about 45° C. Methods for making the quartz crystal are also provided.