Quartz Vibrator Element Etching for Groove Alignment Control
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Solution Overview
Problem
Existing methods for manufacturing vibrator elements face complications due to separate wet and dry etching steps, leading to misalignment issues and restricted design freedom, particularly in forming the outer shape and grooves of tuning fork type vibrators.
Innovation Solution
A method involving a first and second dry etching step on opposite surfaces of a quartz crystal substrate, using protective films to form the outer shapes and grooves simultaneously, allowing for independent control of etching depths and dimensions without relying on micro loading effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wet etching and dry etching are used as separate steps to form outer shape and groove, then manufacturing flexibility is improved, but manufacturing complexity increases and alignment precision deteriorates
Solution Approach 1:
The patent combines the formation of outer shape and groove into a single dry etching step by using a patterned protective film that simultaneously defines both features. This merging eliminates the need for separate wet etching and dry etching steps, reducing manufacturing complexity while maintaining design flexibility through film patterning.
Solution Approach 2:
The protective film is segmented into different regions with different thicknesses or etching resistances, allowing selective etching of groove portions while protecting outer shape portions. This segmentation enables precise control of etching depth in different areas within a single etching step.
2Adaptability or versatility
If wet etching and dry etching are used as separate steps to form outer shape and groove, then design freedom is improved, but manufacturing precision deteriorates due to misalignment
Solution Approach 1:
By merging the formation of outer shape and groove into a single dry etching step using a patterned protective film, the patent eliminates misalignment between separate etching steps. The protective film serves as a common reference for both features, ensuring precise alignment while maintaining design freedom.
Solution Approach 2:
The protective film acts as an intermediary that transfers the desired pattern from the mask to the substrate in a single step. It mediates between the etching process and the final structure, ensuring that both outer shape and groove are formed with precise relative positioning.
3Device complexity
If outer shape and groove are collectively formed using micro loading effect in dry etching, then manufacturing complexity is reduced, but design freedom deteriorates due to restricted dimension setting
Solution Approach 1:
The protective film is designed with local variations in thickness or composition, creating different etching characteristics in different regions. This allows independent control of groove depth and width while maintaining the simplicity of a single etching step, overcoming the limitations of uniform micro loading effect.
Solution Approach 2:
The patent changes parameters of the protective film (thickness, material composition, pattern geometry) to control etching behavior in different regions. By adjusting these parameters, designers can freely set groove dimensions without being constrained by the micro loading effect limitations.
4Adaptability or versatility
If separate wet etching and dry etching steps are used, then design freedom is improved, but productivity deteriorates due to increased manufacturing steps
Solution Approach 1:
The patent merges multiple etching operations into a single dry etching step by using a patterned protective film. This reduces the number of manufacturing steps while maintaining design freedom, thereby improving productivity without sacrificing versatility.
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 reduces manufacturing steps, improves alignment accuracy, enhances design freedom, and ensures precise formation of vibration arms and grooves, thereby improving the vibration properties and reducing unnecessary vibrations.
Implementation Method 1
a first protective film forming step of forming a first protective film on the first substrate surface; a second protective film forming step of forming a second protective film on the second substrate surface
Implementation Method 2
a first dry etching step of dry etching the quartz crystal substrate from a first substrate surface side via the first protective film to form the first surface, the first groove, and outer shapes of the first vibration arm and the second vibration arm
Data Source
AI summary
Provided is a method for manufacturing a vibrator element including a first vibration arm and a second vibration arm that each have a first surface and a second surface. The manufacturing method includes a preparation step of preparing a quartz crystal substrate, a first protective film forming step of forming a first protective film on a first substrate surface of the quartz crystal substrate, a first dry etching step of dry etching the quartz crystal substrate via the first protective film, a second protective film forming step of forming a second protective film on a second substrate surface of the quartz crystal substrate, and a second dry etching step of dry etching the quartz crystal substrate via the second protective film. Outer shapes of the first vibration arm and the second vibration arm are formed from the first surface to the second surface in the first dry etching step, and the outer shapes of the first vibration arm and the second vibration arm are not formed in the second dry etching step.