Head Gimbal Assembly Vibration Isolation via Segmented Wiring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing head gimbal assemblies (HGA) with thin-film piezoelectric elements suffer from out-of-plane vibrations that reduce positioning accuracy due to resonance excitation of the load beam, caused by the expansion and contraction of piezoelectric elements.
Innovation Solution
A head gimbal assembly design featuring a metal plate with an insulating layer and conductive wiring, where piezoelectric elements are supported by independent supporting pads with a low-rigidity insulating layer, preventing the transfer of out-of-plane vibrations to the load beam, thereby reducing unnecessary resonance excitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If piezoelectric elements are mounted on the gimbal section to enable microscopic displacement control, then positioning control capability is improved, but out-of-plane vibrations are generated that reduce positioning accuracy
Solution Approach 1:
The flexure is divided into separate functional sections: a gimbal section carrying the piezoelectric elements and magnetic head, and a load beam section. The wiring member connects these sections while isolating vibrations. This segmentation allows the piezoelectric elements to function for positioning control without transferring their vibrations to the load beam, thus maintaining positioning accuracy.
Solution Approach 2:
The wiring member acts as an intermediary element between the piezoelectric elements and the load beam. It provides electrical connection while mechanically isolating the load beam from out-of-plane vibrations generated by the piezoelectric elements. This mediator allows the system to benefit from piezoelectric positioning control without suffering from vibration-induced accuracy degradation.
2Ease of operation
If piezoelectric elements expand and contract for seek direction displacement, then head positioning capability is improved, but resonance frequency of the load beam is unnecessarily excited
Solution Approach 1:
The structure is segmented into a gimbal section with piezoelectric elements and a load beam section, connected via a wiring member. This segmentation isolates the load beam from the vibrational effects of piezoelectric element operation, allowing head positioning capability to be improved without compromising load beam stability or exciting unwanted resonance.
Solution Approach 2:
The wiring member serves as a mediator that transmits electrical signals while blocking mechanical vibration transmission. This allows the piezoelectric elements to operate for head positioning without transferring their expansion and contraction vibrations to the load beam, thus maintaining load beam stability while improving positioning capability.
3Device complexity
If the piezoelectric element is directly mounted on the gimbal section, then compact structure is achieved, but out-of-plane vibration is transferred to the load beam via the flexure
Solution Approach 1:
The flexure is segmented into a gimbal section and a load beam section, with the wiring member forming a separate connection path. This segmentation allows compact mounting of piezoelectric elements on the gimbal section while preventing vibration transfer to the load beam through the dedicated wiring member connection.
Solution Approach 2:
The wiring member acts as an intermediary that provides electrical connection while blocking the transmission of out-of-plane vibrations from the piezoelectric elements to the load beam. This allows compact structure to be achieved without the harmful effect of vibration transfer.
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 design enhances the positioning accuracy of the magnetic head by suppressing out-of-plane vibrations and minimizing resonance excitation of the load beam, leading to improved control and precision in seek direction displacement.
Implementation Method 1
a thin-film piezoelectric element (PZT element) is mounted on a gimbal section of a flexure and a microscopic displacement is caused in a seek direction of a magnetic head by an expansion and contraction of the piezoelectric element
Implementation Method 2
piezoelectric elements are supported by independent supporting pads with a low-rigidity insulating layer, preventing the transfer of out-of-plane vibrations to the load beam
Data Source
AI summary
A head gimbal assembly includes a load beam, a wiring member including a metal plate disposed on the load beam, a magnetic head attached to a tip section of the wiring member, and a piezoelectric element that is fixed to and supported by supporting pads and deforms in response to a voltage applied thereto. The metal plate includes a tip section to which the magnetic head is fixed, and a base section that is spaced apart from the tip section and is fixed to the load beam. The supporting pads include first and second supporting pads proximate to the tip section and distal from the base section and a third supporting pad proximate to the base section and distal to the tip section, each of supporting pads separated from and independent of both the tip section and the base section.