Quartz Vibrator Bonding Layout for Frequency Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increased number of interfaces between members with different linear expansion coefficients in piezoelectric vibrator devices leads to stress and deformation, deteriorating frequency accuracy.
Innovation Solution
A vibrator device design featuring a first quartz crystal substrate with AT-cut and a relay substrate with Z-cut quartz crystal, both bonded using gold bumps, where the bonding members are arranged to align with the X-axis, minimizing stress from thermal expansion differences and maintaining vibration characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a support member is introduced between the base and the piezoelectric vibrator element, then mechanical and electrical coupling is achieved, but the number of interfaces between members with different linear expansion coefficients increases, leading to increased stress and deformation of the piezoelectric vibrator element
Solution Approach 1:
The patent removes the support member from the structure, eliminating the additional interfaces it created. The piezoelectric vibrator element is directly coupled to the base through bonding members, reducing the number of interfaces between members with different linear expansion coefficients from four to two, thereby reducing stress and deformation while maintaining mechanical and electrical coupling functionality
Solution Approach 2:
The patent merges the mechanical support function and electrical coupling function into a single bonding member structure. The bonding members simultaneously provide mechanical support and electrical connection between the base and the piezoelectric vibrator element, eliminating the need for a separate support member and reducing the number of interfaces
2Reliability
If multiple bonding members are used to couple the piezoelectric vibrator element to the base, then mechanical support and electrical coupling are achieved, but stress from thermal expansion differences causes deformation and deteriorates frequency accuracy
Solution Approach 1:
The patent changes the arrangement parameters of the bonding members by positioning them symmetrically on the X-axis (the electrical axis of the AT-cut quartz crystal substrate). This specific geometric arrangement ensures that stress from thermal expansion differences is distributed symmetrically and does not cause deformation of the piezoelectric vibrator element, thereby maintaining frequency accuracy while providing mechanical support and electrical coupling
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
The design effectively reduces stress and maintains excellent vibration characteristics by aligning the quartz crystal substrates and bonding members to match linear expansion coefficients, preventing degradation of frequency accuracy.
Implementation Method 1
a piezoelectric vibrator element formed of an AT-cut quartz crystal substrate
Implementation Method 2
the stress applied to the piezoelectric vibrator element due to the difference in linear expansion coefficient increases
Data Source
AI summary
The vibrator device includes a vibrator element, a relay substrate, a base, an element-side bonding member for bonding the vibrator element and the relay substrate to each other, and a base-side bonding member for bonding the base and the relay substrate to each other. Further, the element-side bonding member has a first bonding member and s second bonding member arranged side by side along an A axis. Further, an X axis of a first quartz crystal substrate provided to the vibrator element is parallel to the A axis, and a second quartz crystal substrate provided to the relay substrate is a Z-cut quartz crystal substrate.