Elastic Wave IDT Structure for Electrostatic Breakdown Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elastic wave devices are prone to electrostatic breakdown due to static electricity generated during manufacturing, particularly affecting the interdigital transducer (IDT) electrodes.
Innovation Solution
Incorporating a first dielectric film with a resistivity equal to or lower than 1×10^14 Ω·cm between the piezoelectric substrate and the IDT electrode, and optionally a second dielectric film covering the periphery, to facilitate discharge of static electricity to the substrate, thereby reducing the risk of breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dielectric layer with high resistivity is used between the piezoelectric substrate and IDT electrode, then the insulating performance is improved, but static electricity accumulates on the IDT electrodes causing electrostatic breakdown
Solution Approach 1:
The patent changes the resistivity parameter of the dielectric layer from high resistivity (1×10^15 Ω·cm or higher) to a specific range (1×10^12 to less than 1×10^15 Ω·cm). This parameter modification allows the dielectric layer to maintain insulating performance while enabling controlled discharge of static electricity from the IDT electrodes to the piezoelectric substrate, preventing electrostatic breakdown.
Solution Approach 2:
The dielectric layer serves as an intermediary between the IDT electrodes and the piezoelectric substrate. By controlling its resistivity to a specific range, it acts as a mediator that allows gradual discharge of static electricity while maintaining electrical insulation during normal operation, thus resolving the contradiction between insulating performance and static electricity discharge.
2Object-affected harmful factors
If the resistivity of the dielectric layer is reduced to discharge static electricity, then electrostatic breakdown is prevented, but the insulating performance deteriorates
Solution Approach 1:
The patent identifies and applies a specific resistivity range (1×10^12 to less than 1×10^15 Ω·cm) that optimizes the balance between static electricity discharge and insulating performance. This precise parameter control ensures that the dielectric layer can discharge static electricity effectively while maintaining sufficient insulation to prevent deterioration of device 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 solution effectively reduces the likelihood of electrostatic breakdown in the IDT electrodes by ensuring static electricity is discharged to the piezoelectric substrate, improving the reliability of the elastic wave device.
Implementation Method 1
Resistivity of the piezoelectric substrate is equal to or lower than resistivity of the first dielectric film, and the resistivity of the first dielectric film is equal to or lower than about 1×10^14 Ω·cm
Data Source
AI summary
An elastic wave device includes a piezoelectric substrate, a first dielectric film disposed on the piezoelectric substrate, and an IDT electrode laminated on the first dielectric film. The resistivity of the piezoelectric substrate is equal to or lower than the resistivity of the first dielectric film. The resistivity of the first dielectric film is equal to or lower than about 1×1014 Ω·cm.