Piezoelectric Resonator Cavity Frame for Elastic Wave Confinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional elastic wave devices face challenges in effectively confining elastic wave energy within the excitation region and preventing piezoelectric layer deformation or fracture, particularly in piezoelectric thin film resonators used in mobile telephones.
Innovation Solution
The acoustic wave device incorporates a frame structure on excitation electrodes within a cavity, featuring different width portions and a recess with a tapered shape to define a cavity, along with a conductive wall and sealing frame, to enhance energy confinement and prevent piezoelectric layer damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a piezoelectric thin film resonator is used in a mobile telephone, then the device can function as a filter, but the piezoelectric layer is prone to deformation or fracture
Solution Approach 1:
The patent applies beforehand cushioning by introducing a frame structure that surrounds and supports the piezoelectric layer before operational stresses can cause damage. The frame acts as a protective framework that prevents deformation and fracture of the piezoelectric thin film during device operation, thereby maintaining reliability without compromising the layer's strength
Solution Approach 2:
The patent employs a frame structure that provides mechanical support while allowing the piezoelectric thin film to maintain its flexible, thin-film characteristics. The frame acts as a rigid boundary that prevents excessive deformation, while the piezoelectric layer itself remains a thin, flexible film that can undergo controlled strain during operation
2Reliability
If elastic wave energy is not confined within the excitation region, then the device structure can be simpler, but elastic wave energy is lost and performance deteriorates
Solution Approach 1:
The patent applies local quality by creating a frame structure with varying width portions that are strategically positioned to optimize energy confinement. The frame has different width sections that provide enhanced confinement at critical locations while maintaining overall structural efficiency, thereby preventing elastic wave energy loss and improving device performance
Solution Approach 2:
The patent introduces a dimensional element by using a frame structure that extends in multiple directions around the excitation region. This dimensional approach creates a three-dimensional confinement architecture that effectively traps elastic wave energy within the excitation region, preventing energy loss and enhancing performance
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 frame structure effectively confines elastic wave energy and reduces piezoelectric layer deformation and fracture, improving the operational reliability and performance of the device.
Implementation Method 1
a piezoelectric layer on the insulating layer and over the recess to define a cavity
Data Source
AI summary
An acoustic wave device includes an insulating layer including a recess, a piezoelectric layer on the insulating layer and over the recess to define a cavity, a first excitation electrode on a first surface of the piezoelectric layer opposite to the cavity, a second excitation electrode on a second surface of the piezoelectric layer and within the cavity, a dielectric layer on the first excitation electrode, and a first frame on the second excitation electrode and within the cavity.