Magnetic Head Shield Electrode Segmentation for Noise Reduction
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Solution Overview
Problem
Magnetic head devices using the GMR or tunnel effect face reduced reading precision and noise due to the complex shapes and large sizes of the lower and upper shield layers, which affect the magnetic resistance and signal detection.
Innovation Solution
The design includes a first and second shield layer with a predetermined gap, where the second shield layer's end faces extend in a depthwise direction, and conductive electrodes are positioned to form a current path with a simple shape, reducing noise and size while maintaining effective shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lower shield layer and upper shield layer are formed with large area and complicated shape to provide sufficient shielding, then the shielding effect is improved, but the device complexity and noise increase
Solution Approach 1:
The patent divides the current path into separate segments by providing independent lead electrodes for the lower shield layer and upper shield layer. The lower lead electrode is electrically connected to the lower shield layer and the upper lead electrode is electrically connected to the upper shield layer, allowing each shield layer to be independently controlled and optimized without requiring complicated integrated shapes.
2Reliability
If the lower shield layer and upper shield layer are formed with large area to reduce magnetoresistance effect, then the magnetic signal transmission is improved, but the direct current resistance increases and detection output decreases
Solution Approach 1:
The patent applies different properties to different parts of the shield layer structure. The shield layers themselves maintain soft magnetic material properties for effective magnetic flux transmission, while the lead electrodes provide high electrical conductivity through separate metal connections. This local differentiation allows optimal performance in both magnetic signal transmission and electrical conductivity without requiring large areas.
3Reliability
If via-hole conductors are provided on the lower and upper shield layers to electrically connect them, then the electrical connection is improved, but the device complexity and size increase
Solution Approach 1:
The patent extracts the electrical connection function from the shield layer structure itself by providing separate lead electrodes. Instead of forming via-hole conductors within the shield layers, the lead electrodes are provided as distinct elements that electrically connect to the respective shield layers, simplifying the overall structure and reducing manufacturing complexity.
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
This configuration enhances reading precision by minimizing noise and size, allowing for improved signal detection and reduced magnetoresistance effects, resulting in a more efficient magnetic head device.
Implementation Method 1
a detecting element in which a current flows in a thicknesswise direction using a GMR effect or a tunnel effect
Implementation Method 2
a detecting element in which a current flows in a thicknesswise direction using a GMR effect or a tunnel effect
Implementation Method 3
The lower shield layer and the upper shield layer have a function of transmitting a magnetic flux from a recording medium, preventing the magnetic flux from leaking into a region other than the detecting element
Data Source
AI summary
A lower shield layer and an upper shield layer are formed to have a planar shape, and a detecting element is provided between the lower shield layer and the upper shield layer. End faces of the upper shield layer may extend farther in a depthwise direction from a surface facing a recording medium than end faces of the lower shield layer. A lower conductive electrode may be disposed directly adjacent to a facing inner surface of the lower shield layer. An upper conductive electrode may be disposed adjacent to a portion of the upper shield layer. Therefore, the lower shield layer and the upper conductive electrode may be insulated from each other.