Multilayer IDT Electrode Structure for High-Power Acoustic Wave Filters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic wave elements in multiplexers face challenges in achieving high electric power resistance, which is necessary to enhance the electric power resistance of the multiplexer itself.
Innovation Solution
The acoustic wave element incorporates a piezoelectric substrate with an IDT electrode featuring a multilayer structure, comprising a first layer of Al with a sub-component in amounts less than 10% and a second layer of a CuAl2 alloy, optimized for improved electric power resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single-layer Al electrode is used in the acoustic wave element, then the manufacturing process is simple, but the electric power resistance is insufficient
Solution Approach 1:
The patent applies composite materials by using a multilayer electrode structure consisting of Al and CuAl2 alloy layers instead of a single-layer Al electrode. The CuAl2 alloy layer provides enhanced electric power resistance and oxidation resistance, while the Al layer maintains good electrical conductivity. This composite structure resolves the contradiction by improving reliability through material composition rather than increasing structural complexity.
Solution Approach 2:
The patent changes the material parameters of the electrode by introducing a CuAl2 alloy layer with specific composition ratios (Al:Cu = 2:1 or 3:1). This parameter change in material composition fundamentally improves the electric power resistance characteristic without requiring complex multi-component systems, thus resolving the contradiction between reliability improvement and device complexity.
2Reliability
If the electric power resistance of the acoustic wave element is increased, then the performance of the multiplexer is improved, but the electrode material composition becomes more complex
Solution Approach 1:
The patent uses a composite material approach with Al and CuAl2 alloy layers where each layer has a specific function. The Al layer provides baseline conductivity while the CuAl2 layer enhances power resistance. This composite structure improves multiplexer performance while maintaining manufacturing feasibility through established thin-film deposition techniques for metal alloys.
Solution Approach 2:
The patent modifies the electrode material parameters by controlling the composition ratio of Al to Cu (specifically Al:Cu = 2:1 or 3:1) in the CuAl2 alloy layer. This precise parameter control achieves the desired electric power resistance improvement while using standard semiconductor fabrication processes, thus maintaining ease of manufacture despite the enhanced performance requirements.
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 raises the electric power resistance of the acoustic wave element, filter element, and communication apparatus, thereby enhancing the overall performance of the multiplexer.
Implementation Method 1
The acoustic wave element utilizes the characteristic of being able to convert an electrical signal and a surface acoustic wave to each other by the relationship between the excitation electrode and the piezoelectric substrate
Implementation Method 2
a second layer comprised of a CuAl2 alloy
Data Source
AI summary
An acoustic wave element 1 according to the present disclosure includes a piezoelectric substrate 2 and an IDT electrode 3 on the piezoelectric substrate 2. The IDT electrode 3 includes a multilayer structure of a first layer 35 comprised of Al containing 10% or less of a sub-component and a second layer 37 comprised of a CuAl2 alloy. The second layer 37 enables the acoustic wave element 1 to have excellent electric power resistance.