Disk Drive Microactuator With Piezoelectric Element And Peripheral Encapsulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing disk drive microactuators lack an efficient configuration for precise head positioning, particularly in achieving higher bandwidth and track-following resolution, necessitating an improved microactuator design and manufacturing methodology.
Innovation Solution
A method and apparatus for manufacturing microactuators using piezoelectric elements with an electrically conductive layer and a peripheral encapsulation layer of lesser conductivity, where the encapsulation layer is applied only over the peripheral portions and not the exposed areas, to enhance positioning accuracy and prevent particle shedding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional rotary actuator is used for head positioning, then the basic positioning function is achieved, but the bandwidth and track-following resolution are insufficient
Solution Approach 1:
The actuator system is divided into two independent stages: a coarse positioning rotary actuator and a fine positioning microactuator with piezoelectric elements. This segmentation allows each stage to optimize for its specific function, with the microactuator providing high-resolution adjustments without complicating the main rotary actuator design.
Solution Approach 2:
The microactuator serves as an intermediary device between the coarse rotary actuator and the read/write head. It mediates the positioning by taking the coarse position from the rotary actuator and adding fine adjustments, thereby achieving high bandwidth and track-following resolution without requiring the entire actuator system to be complex.
2Object-generated harmful factors
If the entire piezoelectric element surface is covered with encapsulation material, then particle shedding is prevented, but electrical conductivity is reduced
Solution Approach 1:
The encapsulation layer is applied selectively rather than uniformly across the entire piezoelectric element. The peripheral portions are covered with encapsulation material to prevent particle shedding, while the exposed central portions remain uncovered to maintain electrical conductivity. This local differentiation of properties resolves the contradiction between protection and conductivity.
3Reliability
If the exposed portions of the piezoelectric element are left uncovered, then electrical conductivity is maintained, but particle contamination increases
Solution Approach 1:
The encapsulation layer is applied selectively rather than uniformly across the entire piezoelectric element. The peripheral portions are covered with encapsulation material to prevent particle shedding, while the exposed central portions remain uncovered to maintain electrical conductivity. This local differentiation of properties resolves the contradiction between protection and conductivity.
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 enables precise control of head movement with increased bandwidth and reduced particle contamination, improving the overall performance of disk drive microactuators by utilizing piezoelectric elements that expand or contract in response to voltage, facilitating fine-tuned positioning within the disk drive.
Implementation Method 1
utilizing piezoelectric elements that expand or contract in response to voltage, facilitating fine-tuned positioning within the disk drive
Data Source
AI summary
A method of manufacturing a microactuator. The method includes providing a sheet of a piezoelectric material having an electrically conductive layer on at least one side of the sheet. The method includes cutting the sheet to form a plurality of piezoelectric elements. Each of the piezoelectric elements includes a first element side with an electrically conductive layer. Each first element side includes a peripheral portion and an exposed portion interior to the peripheral portion. The method includes forming an encapsulation layer over the peripheral portion and not over the exposed portion of at least one of the sides. The encapsulation layer comprises a material of lesser electrical conductivity than the electrically conductive layer. An apparatus for manufacturing the microactuators may also be provided that includes a first fixture and first and second alignment combs.