Piezoelectric Device Orientation Control Layer Parasitic Capacitance
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Solution Overview
Problem
Piezoelectric devices with electrodes on the same surface fail to establish (100) preferential orientation, leading to reduced piezoelectric characteristics and receiving sensitivity due to parasitic capacitance formation.
Innovation Solution
A piezoelectric device with an elastic layer having an amorphous or random surface structure, a piezoelectric body with (100) orientation, and electrodes positioned to avoid parasitic capacitance, utilizing a transition metal oxide with a perovskite structure and an orientation control layer to enhance piezoelectric response and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If first and second electrodes are disposed on the same surface of the piezoelectric body, then the device structure is simplified, but (100) preferential orientation cannot be established and parasitic capacitance increases
Solution Approach 1:
The patent transitions from a two-dimensional electrode arrangement (both electrodes on the same surface) to a three-dimensional configuration by introducing an orientation control layer between the piezoelectric body and the elastic layer. This additional layer creates spatial separation that enables (100) preferential orientation while maintaining the same-surface electrode configuration, effectively adding a dimensional solution to a planar problem.
Solution Approach 2:
The orientation control layer acts as an intermediary element between the piezoelectric body and the elastic layer. This intermediate layer with amorphous structure or random orientation serves as a mediator that prevents the formation of parasitic capacitance while enabling the piezoelectric body to achieve (100) preferential orientation, thus resolving the contradiction between simplified structure and high receiving sensitivity.
2Reliability
If (100) preferential orientation is established in the piezoelectric body, then piezoelectric characteristics are enhanced, but device structure becomes more complex
Solution Approach 1:
The patent changes the structural parameter of the interface between the piezoelectric body and the elastic layer by introducing an orientation control layer with specific properties (amorphous structure or random orientation). This parameter change in the layer structure enables the piezoelectric body to achieve (100) preferential orientation without requiring complex external processing or additional manufacturing steps.
3Reliability
If insulating surface region is formed at the bottom surface of the piezoelectric body, then parasitic capacitance is reduced, but manufacturing process becomes more complex
Solution Approach 1:
The patent merges the function of the insulating surface region with the orientation control layer. The orientation control layer simultaneously serves as both the insulating layer that prevents parasitic capacitance formation and the structural element that enables (100) preferential orientation. This merging of functions eliminates the need for separate insulating layer deposition processes, simplifying the manufacturing workflow.
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 achieves high receiving sensitivity by establishing (100) preferential orientation, reducing parasitic capacitance, and optimizing the piezoelectric response, thereby improving the device's performance in ultrasonic imaging applications.
Implementation Method 1
If the elastic layer vibrates due to the ultrasonic wave from the outside, the piezoelectric body is distorted on the elastic layer. The strain of the piezoelectric body generates an electric potential in the piezoelectric body.
Data Source
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AI summary
A piezoelectric device (57) includes: an elastic layer (58) that forms an insulating surface region at least partially and has an amorphous structure or random orientation at least in the surface region; a piezoelectric body (63) that is provided on the elastic layer (58), has a first surface in contact with the elastic layer (58) and a second surface on an opposite side to the first surface, and is (100) preferentially oriented in an orientation region corresponding to the surface region in a plan view; a first electrode (61) provided on the second surface of the piezoelectric body (63); and a second electrode (62) that is provided on the second surface of the piezoelectric body (63) . A gap (64) is formed between the first (61) and second electrodes (62) corresponding to the orientation region in the plan view.