Flexible Pivot Oscillator Frequency Tuning via Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible-pivot oscillators in watch movements exhibit geometric dispersion during microfabrication, leading to variations in oscillation frequency due to inaccuracies in manufacturing processes like etching, resulting in inconsistent performance.
Innovation Solution
A method involving precise etching of silicon-based oscillators, followed by measurement and adjustment of dimensions through material addition or removal to achieve a predetermined oscillation frequency, utilizing deep reactive ion etching and subsequent oxidation and layer removal to refine dimensions, ensuring high precision and consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If microfabrication techniques such as etching a silicon wafer are used to manufacture oscillators, then productivity and manufacturing efficiency are improved, but geometric dispersion and variation in oscillation frequency occur due to manufacturing inaccuracies
Solution Approach 1:
The patent applies preliminary action by intentionally manufacturing oscillators with dimensions that are deliberately different from the final target dimensions. The etching process is used to create a preliminary structure that will be subsequently adjusted through oxidation and material removal to achieve the precise final dimensions and oscillation frequency.
Solution Approach 2:
The patent utilizes parameter changes by controlling the oxidation process to transform silicon-based material into silicon dioxide, thereby changing the physical and chemical parameters of the material. This allows for precise adjustment of the oscillator dimensions and oscillation frequency by removing specific thicknesses of oxidized material.
2Manufacturing precision
If dimensional adjustments are made through material addition or removal to achieve predetermined oscillation frequency, then manufacturing precision and frequency consistency are improved, but device complexity and process steps increase
Solution Approach 1:
The patent introduces an intermediary substance (oxidizing agent) that transforms the silicon-based material into silicon dioxide. This intermediary step enables precise material removal by converting the material into a form that can be selectively removed, thereby achieving dimensional precision without directly complex mechanical adjustment processes.
Solution Approach 2:
The patent replaces traditional mechanical dimensional adjustment methods with a chemical process (oxidation). Instead of mechanically adding or removing material through complex machining operations, the invention uses chemical oxidation to transform the material, followed by controlled removal of the oxidized layer, simplifying the overall adjustment process 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 approach ensures precise dimensional control, stabilizing oscillation frequency and reducing geometric variations, thereby enhancing the reliability and accuracy of watch movement oscillators.
Implementation Method 1
the material to be removed is oxidized to transform the silicon-based material into silicon dioxide
Implementation Method 2
an adjustment of the oscillation frequency can be carried out at the level of the elastic blades by a heat treatment or an ablation of material using a laser beam
Data Source
Figure 1
Figure 2~5
AI summary
The manufacturing process relates to a flexible pivot oscillator (1) of a predetermined frequency. The flexible pivot oscillator (1) comprises a support (2), a flexible pivot (4), and a cord (3) suspended from the support (2) by the flexible pivot (4). The flexible pivot (4) is arranged to guide the cord (3) in rotation relative to the support (2) and to elastically return the cord (3) to a rest position.The method comprises the following steps: a) forming a flexible pivot oscillator comprising the support (2), the flexible pivot (4) and the serge (3) but having dimensions different from the dimensions required to obtain the flexible pivot oscillator of a predetermined frequency; b) measuring the frequency of the oscillator formed in step a); c) from the measurement made in step b), calculating at least one thickness of material to be added, removed or modified on the oscillator formed in step a) to obtain said flexible pivot oscillator of a predetermined frequency; d) from the calculation made in step c), modifying the oscillator formed in step a) in order to obtain said flexible pivot oscillator of a predetermined frequency.