Side Shielded Read Transducer Cross-Track Resolution
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Solution Overview
Problem
Conventional magnetic recording read transducers face challenges in achieving high cross-track resolution due to limitations in shield-to-shield spacing and magnetic flux interference, which hinder the ability to read higher density memories effectively.
Innovation Solution
The introduction of soft magnetic side shields with high full film permeability, positioned adjacent to the edges of the sensor layer, which act as both shields and magnetic biasers to stabilize the sensor layer's magnetization, thereby improving cross-track resolution without increasing shield-to-shield spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the shield-to-shield spacing is reduced to read higher density memories, then the recording density is improved, but the cross-track resolution deteriorates due to magnetic flux entering from the sides of the sensor layer
Solution Approach 1:
Side shields are introduced as intermediary magnetic shielding elements positioned between the main shields and the sensor layer edges. These side shields intercept and redirect magnetic flux that would otherwise enter the sensor layer from the sides, thereby maintaining cross-track resolution even when the shield-to-shield spacing is reduced for higher recording density.
Solution Approach 2:
The magnetic shielding function is segmented into multiple components: main shields at the ends and additional side shields positioned adjacent to the sensor layer edges. This segmentation allows independent optimization of each shielding element's position and geometry to simultaneously achieve high recording density and maintain cross-track resolution.
2Measurement precision
If an in-stack hard bias layer is introduced to improve cross-track resolution, then the cross-track resolution is improved, but the shield-to-shield spacing increases which is undesirable
Solution Approach 1:
Side shields serve as intermediary structures that provide both magnetic shielding and biasing functions. By positioning these side shields adjacent to the sensor layer edges, the patent achieves improved cross-track resolution through enhanced magnetic flux management without requiring additional space-consuming in-stack hard bias layers, thus maintaining compact shield-to-shield spacing.
Solution Approach 2:
The side shields perform multiple functions simultaneously: they provide magnetic shielding from lateral flux and also serve as magnetic bias structures for the sensor layer. This multi-functionality eliminates the need for separate in-stack hard bias layers, thereby improving cross-track resolution without increasing shield-to-shield spacing.
3Measurement precision
If the physical width of the sensor layer is decreased to improve cross-track resolution, then the cross-track resolution is improved, but the magnetic flux from sides adversely impacts the sensor layer's ability to accurately read data
Solution Approach 1:
Side shields are positioned as intermediary structures between the main shields and the narrow sensor layer edges. These side shields intercept magnetic flux before it can reach the sensor layer from the sides, protecting the narrow sensor structure from flux interference while allowing the sensor to maintain its narrow width for high cross-track resolution.
Solution Approach 2:
The side shields provide preliminary magnetic shielding by intercepting and redirecting magnetic flux before it can adversely affect the sensor layer. This preliminary protective action prevents magnetic flux interference from degrading the cross-track resolution, enabling the use of narrower sensor layers without suffering from edge flux effects.
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 cross-track resolution and allows for the use of methods like shingle recording while maintaining a suitable magnetic bias and reducing stray magnetic field interference, without the need for an in-stack hard bias layer.
Implementation Method 1
The soft magnetic side shield(s) has a full film permeability of at least ten
Implementation Method 2
The soft magnetic side shield(s) are adjacent to the edge(s) of the sensor layer... act as both shields and magnetic biasers
Data Source
AI summary
A method and system for providing a magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a magnetoresistive sensor, at least one soft magnetic side shield, and a second shield. The magnetoresistive sensor includes a sensor layer having at least one edge in the track width direction along the ABS. The at least one soft magnetic side shield is adjacent to the at least one edge of the sensor layer. The at least one soft magnetic side shield has a full film permeability of at least ten. The magnetoresistive sensor is between the first shield and the second shield and free of an in-stack hard bias layer.