Elastic Wave Device Wiring Electrode Edge Width for Burr Reduction
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Solution Overview
Problem
Existing methods for manufacturing elastic wave devices often result in burrs from metal wiring, leading to potential short circuits and degraded device performance due to the thick wiring metal being left on split lines during the singulation process.
Innovation Solution
The elastic wave device features a wiring electrode with a narrower width at its edge, a radius of curvature of 3 μm or less, and a manufacturing method where the wiring electrode is formed to cross split lines, allowing for cleaner splitting and reduced burr production, along with the use of a high-acoustic-velocity member and low-acoustic-velocity film to enhance wave confinement and prevent burr formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the wiring electrode is made thick to ensure electrical connectivity, then electrical conductivity is improved, but burrs are generated during splitting causing short circuits
Solution Approach 1:
The wiring electrode is divided into two distinct regions: a first region with a first width for electrical connectivity and a second region with a second width (narrower than the first) for clean splitting. This segmentation allows the thick portion to maintain conductivity while the narrow portion prevents burr formation during the splitting process.
Solution Approach 2:
Different portions of the wiring electrode are given different widths to serve different functions. The first region has a larger width optimized for electrical conductivity, while the second region has a smaller width optimized for clean splitting without burr generation. This local differentiation resolves the contradiction between conductivity and burr prevention.
2Ease of manufacture
If the wiring electrode width is uniform, then manufacturing is simpler, but burrs are produced during splitting
Solution Approach 1:
The wiring electrode is segmented into two width regions, which can be formed using standard photolithography and metal deposition processes. The segmentation is achieved through pattern design rather than complex manufacturing steps, maintaining ease of manufacture while enabling clean splitting in the narrower second region.
Data Source
AI summary
An elastic wave device includes a piezoelectric body including a main surface, an IDT electrode provided on the main surface of the piezoelectric body, and a wiring electrode provided on the main surface of the piezoelectric body and electrically connected to the IDT electrode, in which the wiring electrode includes a portion that extends to an edge of the main surface of the piezoelectric body, and a width of the wiring electrode on the edge is narrower than a width of the wiring electrode in a portion not on the edge.