Thin-Film Piezoelectric Element with Alloy Protective Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thin-film piezoelectric-material elements face issues with static electricity due to size differences between the piezoelectric-material film and electrode films, leading to electric failures.
Innovation Solution
A thin-film piezoelectric-material element with a laminated structure featuring a lower and upper electrode film, a piezoelectric-material film, and protective films made of alloy materials including Fe, Co, and Mo, with riser and step surfaces on the upper electrode film, and a surface layer insulating film to prevent static electricity accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the piezoelectric-material film is made larger than the upper electrode film to improve coverage, then the film size is increased, but static electricity accumulates on the exposed piezoelectric-material film surface causing electric failures
Solution Approach 1:
An insulating film is introduced as an intermediary layer between the piezoelectric-material film and the external environment. This insulating film covers the exposed piezoelectric-material film surface that extends beyond the upper electrode film, preventing static electricity accumulation while maintaining the beneficial larger piezoelectric-material film area for improved coverage and performance.
2Reliability
If the piezoelectric-material film size is reduced to match the upper electrode film size to prevent static electricity, then static electricity accumulation is reduced, but the coverage and effective area are decreased
Solution Approach 1:
The structure is segmented into distinct functional zones: the piezoelectric-material film provides the active functional area with larger coverage, while the insulating film provides the protective coverage area that prevents static electricity accumulation. This segmentation allows each layer to optimize its size for its specific function without compromising the other.
3Manufacturing precision
If taper-shaped or step-shaped processing is applied to the piezoelectric-material film side surface to improve manufacturing, then manufacturing precision is improved, but the size difference between piezoelectric-material film and upper electrode film causes static electricity issues
Solution Approach 1:
The insulating film serves as a mediator that eliminates the harmful effect of the size difference between the piezoelectric-material film and upper electrode film. Regardless of whether the piezoelectric-material film has taper-shaped or step-shaped side surfaces from processing, the insulating film covers the exposed portions, preventing static electricity accumulation while allowing the manufacturing precision improvements to be maintained.
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 prevents static electricity buildup and maintains the performance of the thin-film piezoelectric-material element, reducing the likelihood of electric failures and ensuring stable operation.
Implementation Method 1
A micro actuator using a thin-film piezoelectric-material element is known formerly as the supplementary actuator. The thin-film piezoelectric-material element has a piezoelectric-material and a pair of electrodes formed to sandwich the piezoelectric-material
Data Source
AI summary
A thin-film piezoelectric-material element includes a laminated structure part having a lower electrode film, a piezoelectric-material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric-material film, a lower piezoelectric-material protective-film being formed with alloy material, and an upper piezoelectric-material protective-film being formed with alloy material. The piezoelectric-material film includes a size larger than the upper electrode film, a riser end-surface and step-surface formed on a top-surface of the upper electrode film side. The riser end-surface connects smoothly with a peripheral end-surface of the upper electrode film and vertically intersects with the top-surface. The step-surface intersects vertically with the riser end-surface. The lower piezoelectric-material protective-film, and the upper piezoelectric-material protective-film are formed with alloy material including Fe as main ingredient and having Co and Mo, by Ion beam deposition.