Thin-Film Magnetic Head Non-Magnetic Layer Eddy-Current Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thin-film magnetic heads face challenges in achieving sufficient write characteristics in the high-frequency band due to eddy-current loss, magnetic flux leakage, adjacent track erase, thermal pole tip protrusion, and non-linear transition shift, which affect recording density and data integrity.
Innovation Solution
Incorporating a non-magnetic layer within the magnetic layers of the thin-film magnetic head, with surfaces other than the side surfaces covered by magnetic material, reduces eddy-current loss and magnetic flux leakage, thereby enhancing write field intensity and suppressing unwanted phenomena like adjacent track erase and thermal pole tip protrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a non-magnetic insulating layer is added to suppress eddy-current loss, then eddy-current loss is reduced, but magnetic flux leakage increases
Solution Approach 1:
A shield magnetic layer is introduced as an intermediary component between the non-magnetic insulating layer and the external environment. This shield layer prevents magnetic flux leakage caused by the non-magnetic insulating layer while maintaining the eddy-current suppression benefits. The shield magnetic layer acts as a mediator that resolves the conflict between reducing eddy-current loss and preventing magnetic flux leakage.
Solution Approach 2:
The invention uses a composite structure combining multiple materials with different properties: non-magnetic insulating material for eddy-current suppression, magnetic material for flux containment, and protective coating material for surface protection. This composite approach allows simultaneous achievement of eddy-current loss reduction and magnetic flux leakage prevention.
2Ease of manufacture
If conventional magnetic head structures are used, then manufacturing is simpler, but write characteristics in high-frequency band are insufficient
Solution Approach 1:
The magnetic head structure is segmented into multiple functional layers: upper magnetic layer with non-magnetic insulating layer for eddy-current suppression, lower magnetic layer for magnetic flux generation, shield magnetic layer for flux containment, and protective coating for surface protection. This segmentation allows each layer to optimize its specific function while maintaining overall manufacturability through established thin-film deposition techniques.
Solution Approach 2:
Different regions of the magnetic head structure have different material properties optimized for their specific functions. The upper magnetic layer has non-magnetic insulating properties for eddy-current suppression, while the shield magnetic layer has high magnetic permeability for flux containment. This local optimization of material properties improves write characteristics without significantly complicating the manufacturing process.
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 improves write characteristics in the high-frequency band by maintaining sufficient write field intensity, reducing adjacent track erase and thermal pole tip protrusion, and minimizing non-linear transition shift, leading to enhanced recording density and data integrity.
Implementation Method 1
eddy-current loss generated in the magnetic layers
Implementation Method 2
These magnetic layers act as magnetic poles
Implementation Method 3
electromagnetic coil element
Implementation Method 4
magnetic flux leakage
Data Source
AI summary
Provided is a thin-film magnetic having improved write characteristics in the high-frequency band. The head comprises an electromagnetic coil element comprising upper and lower magnetic layers, a write gap layer and a write coil layer, and in the electromagnetic coil element, at least one non-magnetic layer is provided within the upper magnetic layer, and further, an upper surface, a lower surface, at least a portion of a front surface and at least a portion of a rear surface of the non-magnetic layer are covered with magnetic material of at least one of the upper magnetic layer and the lower magnetic layer.