Acoustic Wave Electrode Layout to Prevent Dicing Short Circuits
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Solution Overview
Problem
The existing acoustic wave devices suffer from a short-circuit defect due to measurement electrodes losing potential after cutting, which can lead to contact with multiple electrodes of different potentials during the dicing process.
Innovation Solution
The acoustic wave device and its manufacturing method involve designing the plane electrode 13 such that its maximum distance between end portions is smaller than the minimum distance between other electrodes with different potentials, preventing short-circuit defects by ensuring no contact occurs during separation or isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the collective board is divided into individual chips through cutting with a dicing machine, then the manufacturing process can proceed to face-down bonding, but the measurement electrodes may ride over and come into contact with electrodes having different potentials, causing short-circuit defects
Solution Approach 1:
The measurement electrode is extracted from the functional electrode structure by forming it as a separate electrode pattern on the dicing line. This separation allows the measurement electrode to be electrically isolated from other electrodes after cutting, preventing short-circuit defects while enabling continuous manufacturing progression.
Solution Approach 2:
The measurement electrode acts as an intermediary element positioned on the dicing line that provides a reference potential during the cutting process. By being formed separately and maintaining its own potential, it serves as a mediator that prevents direct contact between electrodes of different potentials during the dicing operation.
2Ease of manufacture
If the measurement electrode is formed on the dicing line and divided through cutting, then the electrode structure can be completed, but the separated electrode has no potential and may cause short-circuit defects
Solution Approach 1:
The electrode system is segmented into functional electrodes and a separate measurement electrode. The measurement electrode is formed as a distinct pattern on the dicing line, allowing it to be electrically isolated after cutting while maintaining its reference potential function. This segmentation enables complete electrode structure formation without compromising reliability.
3Reliability
If the maximum distance between end portions of the plane electrode is made smaller than the minimum distance between other electrodes with different potentials, then short-circuit defects are prevented, but the electrode design becomes more constrained
Solution Approach 1:
The measurement electrode is designed with specific local characteristics: it is formed only on the dicing line area and has a limited extent in the cutting width direction. This local quality approach allows the electrode to fulfill its measurement function while maintaining safe distances from other electrodes, preventing short-circuits without overly constraining the overall device design.
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 reduces or prevents short-circuit defects in acoustic wave devices by ensuring that isolated plane electrodes do not come into contact with other electrodes of different potentials, thereby enhancing the reliability and performance of the devices.
Implementation Method 1
a piezoelectric substrate 10 having piezoelectricity... a functional electrode 11 provided on the main surface 10a and performing electromechanical conversion with the piezoelectric substrate 10
Data Source
AI summary
An acoustic wave device includes a piezoelectric substrate including first and second main surfaces, a mounting substrate including third and fourth main surfaces, a functional electrode on the first main surface to perform electromechanical conversion with the piezoelectric substrate, first and second plane electrodes on the first main surface and connected to the functional electrode, and a third plane electrode on the first main surface and in contact with an end side of the piezoelectric substrate, and not connected to the functional electrode and the plane electrode, and bump electrodes bonded to the first and third main surfaces. A maximum distance D13max between two end portions of the third plane electrode is smaller than a minimum distance D1min of distances between two of the first and second plane electrodes having different potentials from each other.