Quartz Vibration Element Etching for Aligned Grooves and Outer Shape
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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 a dry-etching process that forms both the outer shape and grooves of a vibration element simultaneously, using a quartz crystal substrate with a base film and protective film to control etching depths and dimensions, allowing for high design freedom without 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 process is more flexible, but manufacturing precision deteriorates due to displacement between groove and outer shape
Solution Approach 1:
The patent combines the formation of outer shape and groove into a single dry-etching step by using a multi-layer film structure (first base film and first protective film) as etching masks. The first base film defines the outer shape while the first protective film defines the groove position, allowing both features to be formed simultaneously with precise alignment without displacement issues that occur in multi-step processes.
2Manufacturing precision
If outer shape and groove are collectively formed by micro loading effect in dry-etching, then manufacturing precision is improved, but device complexity increases due to restricted design freedom
Solution Approach 1:
The patent segments the etching mask function into two independent layers: the first base film for defining outer shape and the first protective film for defining groove. This segmentation allows each layer to be independently designed and patterned, providing full design freedom for both outer shape and groove dimensions without being constrained by micro loading effects that limit collective formation methods.
Solution Approach 2:
The first protective film acts as an intermediary layer between the first base film and the quartz crystal substrate. This intermediary structure enables independent control of groove formation while maintaining precise alignment with the outer shape defined by the first base film, thereby achieving both manufacturing precision and design freedom.
3Adaptability or versatility
If separate wet-etching and dry-etching steps are used, then design freedom is maintained, but reliability deteriorates due to unnecessary vibration from displacement
Solution Approach 1:
The patent merges outer shape and groove formation into a single dry-etching process using a multi-layer mask system, achieving precise alignment that eliminates displacement-induced unnecessary vibrations. This maintains design freedom through independent mask patterning while improving reliability by ensuring accurate geometric relationships between structural features.
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, prevents groove displacement, improves forming accuracy, and enhances design flexibility by controlling dimensions of the vibrating arms and grooves, thereby improving the vibration characteristics of the element.
Implementation Method 1
a 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 grooves, and outer shapes
Data Source
AI summary
A method for manufacturing a vibration element includes, a 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 protective film forming step of forming a first protective film in a bank portion forming region of the first base film, and a dry-etching step of dry-etching the quartz crystal substrate through the first base film and the first protective film.