Quartz Vibration Element Etching for Precise Groove Alignment
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Solution Overview
Problem
Existing methods for manufacturing vibration elements, such as those described in JP-A-2013-175933 and JP-A-2007-013382, face challenges in either having complex manufacturing steps leading to displacement issues or restricted design freedom due to the use of micro loading effects.
Innovation Solution
A method involving dry-etching from both sides of a quartz crystal substrate using protective and base films to form vibrating arms and grooves simultaneously, allowing for independent control of dimensions and reducing the need for micro loading effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If wet-etching and dry-etching are used as separate steps to form outer shape and groove, then manufacturing precision can be maintained, but device complexity increases and manufacturing precision deteriorates due to groove displacement
Solution Approach 1:
The patent combines the formation of outer shape and groove into a single dry-etching step by using a resist pattern that defines both features simultaneously. This merging eliminates the need for separate wet-etching and dry-etching steps, reducing process complexity while maintaining alignment precision because both features are etched in the same step without intermediate handling that could cause displacement.
Solution Approach 2:
The patent segments the etching process into selective regions using a resist pattern that distinguishes between outer shape formation areas and groove formation areas. By applying different etching conditions or mask patterns to different segments of the substrate, the method achieves precise control over both outer shape and groove dimensions within a single etching step.
2Device complexity
If outer shape and groove are collectively formed by micro loading effect in dry-etching, then device complexity is reduced, but manufacturing precision deteriorates due to restricted dimension settings
Solution Approach 1:
The patent applies local quality by using a resist pattern with different thicknesses or material compositions in different regions. The resist pattern is designed such that certain areas have properties optimized for outer shape formation while other areas have properties optimized for groove formation, allowing independent dimensional control of each feature type within the same etching process.
Solution Approach 2:
The patent changes etching parameters such as gas flow rates, power levels, or pressure conditions during the etching process to selectively control the etching rate in different regions. By dynamically adjusting parameters, the method achieves independent control over outer shape and groove dimensions without relying on micro loading effects, thereby maintaining high dimensional precision.
3Manufacturing precision
If separate wet-etching and dry-etching steps are used, then dimensional control is maintained, but productivity decreases due to increased manufacturing steps
Solution Approach 1:
The patent merges multiple etching operations into a single dry-etching step by carefully designing the resist pattern and etching conditions. This consolidation eliminates intermediate steps such as resist removal and re-application, directly improving manufacturing throughput while maintaining the ability to precisely control both outer shape and groove dimensions through the unified process.
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 approach enables the formation of vibration elements with improved design freedom and reduced manufacturing complexity, enhancing vibration characteristics and accuracy without unnecessary vibrations.
Implementation Method 1
a first dry-etching step of dry-etching the quartz crystal substrate from a first substrate surface side through the first base film and the first protective film to form the first surfaces, the first grooves, and outer shapes of the first vibrating arm and the second vibrating arm
Data Source
AI summary
A method for manufacturing a vibration element includes, a first base film forming step of forming a first base film at a first substrate surface of a quartz crystal substrate in first and second vibrating arm forming regions, a first protective film forming step of forming a first protective film in a first bank portion forming region of the first base film, a first dry-etching step of dry-etching the quartz crystal substrate through the first base film and the first protective film, a second base film forming step of forming a second base film at a second substrate surface of the quartz crystal substrate in the first and second vibrating arm forming regions, a second protective film forming step of forming a second protective film in a second bank portion forming region of the second base film, and a second dry-etching step of dry-etching the quartz crystal substrate through the second base film and the second protective film.