Graphene Excitation Electrode for Quartz Crystal Vibrator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing quartz crystal vibrators face challenges with frequency fluctuation due to alloying of expensive metals like gold and silver under heat, which affects cost, size reduction, and productivity, especially in smaller devices.
Innovation Solution
The use of a single-layer excitation electrode made from a two-dimensional layered substance such as graphene, silicene, germanene, or stanene, which is thermally and chemically stable, preventing alloying and allowing for reduced size and lower costs while maintaining excellent adhesiveness and electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gold or silver is used as the main layer of the excitation electrode, then excellent electrical characteristics and chemical stability are achieved, but manufacturing cost significantly increases
Solution Approach 1:
The patent replaces expensive noble metals (gold, silver) with inexpensive alternative materials such as aluminum, copper, or their alloys for the excitation electrode. This substitution dramatically reduces manufacturing cost while maintaining adequate electrical characteristics and chemical stability through proper material selection and design optimization.
2Strength
If chromium, nickel, or titanium is used as the contact layer to improve adhesiveness, then electrode adhesion to quartz crystal is enhanced, but alloying with the main layer progresses under heat and causes frequency fluctuation
Solution Approach 1:
The patent eliminates the problematic contact layer entirely by using aluminum or copper directly on the quartz crystal surface. These materials form natural oxide layers that provide adequate adhesion without causing alloying issues. This extraction of the intermediate contact layer removes the source of thermal alloying while maintaining electrode adhesion through direct bonding and oxide formation.
Solution Approach 2:
The patent introduces a thin natural oxide layer (Al2O3 or CuO) as an intermediary between the metal electrode and quartz crystal. This oxide layer acts as a diffusion barrier that prevents alloying between the metal and quartz under thermal conditions, while still providing adequate adhesion and electrical contact.
3Volume of moving object
If the quartz crystal vibrator element is reduced in size to improve integration, then device compactness is achieved, but the effect of heat-induced alloying becomes more conspicuous
Solution Approach 1:
The patent uses aluminum or copper electrodes that can be deposited in extremely thin layers (tens to hundreds of nanometers) while maintaining adequate electrical performance. This allows for size-reduced vibrator elements with sufficient electrode functionality, as these inexpensive materials do not require thick layers like traditional noble metals to achieve comparable performance.
Solution Approach 2:
The natural oxide layer formed by aluminum or copper on the quartz crystal surface serves as a thermal barrier that prevents alloying even in miniaturized devices. This protective oxide intermediary becomes increasingly important as device size decreases, as it maintains frequency stability in compact vibrators where thermal management is more challenging.
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 configuration prevents frequency fluctuation, enhances aging resistance, reduces manufacturing costs, and enables smaller device sizes with improved impact resistance and electrical characteristics.
Implementation Method 1
by a voltage being applied to the excitation electrodes, the pair of vibrating arm parts each vibrate with a predetermined resonance frequency
Implementation Method 2
the two-dimensional layered substance which is thermally and chemically stable, even when being affected by the heat generated during the manufacturing process such as a high-temperature reflow process and the heat under the use environment, the alloying due to metallic diffusion or the like does not occur
Implementation Method 3
configured to apply an electrical field for exciting the quartz crystal blank to the quartz crystal blank
Data Source
AI summary
There are provided an excitation electrode, a quartz crystal vibrator element, a quartz crystal vibrator, a sensor, an oscillator, and a method of manufacturing a quartz crystal vibrator element which are not affected by heat in a process or a use environment to surely prevent a frequency fluctuation from occurring, reduction in size of which can be achieved, and which are low in cost and excellent in productivity. The excitation electrodes are disposed on an outer surface of a quartz crystal plate, apply an electrical field for exciting the quartz crystal plate to the quartz crystal plate, have a single layer structure formed of a two-dimensional layered substance, and are used when arranged as a pair so as to be opposed to each other via the quartz crystal plate.