Vibration Device Parasitic Capacitance Reduction via Direct Substrate Joining
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Solution Overview
Problem
Existing vibration devices face issues with parasitic capacitance due to metal films used for anodic joining, which affects the characteristics of the vibration element.
Innovation Solution
A vibration device with a base substrate of a first conductivity type, a lid substrate, and a vibration element sandwiched between them, using a coupling member to electrically connect the wiring and vibration element, eliminating the need for metal films as pull-out wiring, thereby reducing parasitic capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal films are used for anodic joining to connect the vibration element to external circuits, then electrical connection is achieved, but parasitic capacitance occurs between the metal film and other wirings which adversely affects the characteristics of the vibration element
Solution Approach 1:
The patent extracts and removes the metal film from the electrical connection path between the vibration element and external circuits. Instead of using metal films for anodic joining, the invention uses direct anodic joining of the base substrate to the frame, eliminating the intermediate metal film that causes parasitic capacitance. This extraction of the harmful component directly resolves the contradiction between achieving electrical connection and avoiding parasitic capacitance.
Solution Approach 2:
The patent introduces a new intermediary structure - the base substrate with anodically joined frame - to replace the metal film as the connecting element. The base substrate serves as a mediator that provides both mechanical support and electrical connection without introducing parasitic capacitance, as it is directly anodically joined to the frame rather than using separate metal films.
2Reliability
If metal films are used for anodic joining, then electrical connection is established, but the complexity of the structure increases due to additional layers and materials
Solution Approach 1:
The patent merges the functions of the base substrate, the anodic joining layer, and the electrical connection into a single integrated structure. The base substrate is directly anodically joined to the frame, combining mechanical support and electrical connection functions without requiring separate metal film layers. This merging reduces structural complexity while maintaining reliable electrical connection.
Solution Approach 2:
The base substrate serves multiple functions simultaneously: it provides mechanical support for the vibration element, acts as an electrical conductor for signal transmission, and forms the anodic joining connection to the frame. This multi-functionality eliminates the need for separate metal films and reduces overall structural complexity.
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 effectively suppresses parasitic capacitance, improving the characteristics of the vibration element by ensuring low resistance contact and reducing external disturbances, enhancing the reliability of the vibration device.
Implementation Method 1
The wiring and the coupling member are in contact with the first contact surface, and are electrically coupled to each other via the first contact area
Implementation Method 2
a vibration element disposed between the base substrate and the lid substrate
Data Source
AI summary
A vibration device includes: a base substrate which is a first conductivity type semiconductor substrate; a lid substrate; a vibration element disposed between the base substrate and the lid substrate; a wiring disposed on a surface of the base substrate at the lid substrate side; and a coupling member that electrically couples the wiring and the vibration element to each other. The base substrate includes a second conductivity type well, which is different from the first conductivity type, and a first conductivity type first contact area that is disposed in the well and that has a first contact surface which is a part of the surface. The wiring and the coupling member are in contact with the first contact surface, and are electrically coupled to each other via the first contact area.