CPP Read Transducer With Recessed Sensor And Flux Guide
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Solution Overview
Problem
Magnetic tape heads with CPP reader transducers are prone to electrical shorts due to contact with asperities on the tape medium, leading to reduced sensitivity and inability to read data tracks effectively, as conventional soft bias technology from hard disk drives is not suitable for tape heads and shunts transition flux away from the sensor.
Innovation Solution
A module design with a recessed sensor, a flux guide, a soft bias layer, and a stabilization layer, along with a nonmagnetic exchange break layer, which magnetically decouples the sensor and flux guide from the stabilization layer, providing side shielding and a higher remanence bias field to prevent shorting and enhance data retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a CPP reader transducer is used in a tape head, then data reading capability is improved, but electrical shorts occur due to contact with tape asperities
Solution Approach 1:
A nonmagnetic exchange break layer is introduced as an intermediary between the sensor and the stabilization layer. This layer prevents direct contact and electrical shorting between the sensor and tape asperities while still allowing magnetic flux to pass through for data reading, thus resolving the contradiction between measurement precision and reliability
Solution Approach 2:
The sensor is recessed from the media facing surface, extracting it from direct contact with the tape medium. This positioning removes the sensor from the harmful interaction with asperities while maintaining its data reading function through the flux guide structure
2Force
If conventional soft bias technology is used, then bias field is provided, but transition flux is shunted away from the sensor
Solution Approach 1:
The soft bias layer is positioned specifically on opposite sides of the sensor in the cross-track direction, providing localized bias fields where needed without creating flux shunting paths. This selective positioning maintains signal flux to the sensor while providing the necessary bias field for operation
Solution Approach 2:
The biasing structure is segmented into discrete soft bias layers positioned on opposite sides of the sensor, rather than using a continuous conventional soft bias structure. This segmentation allows the bias field to be applied locally without shunting transition flux away from the sensor
3Reliability
If the sensor is recessed from the media facing surface, then electrical shorting is reduced, but flux coupling to the sensor is reduced
Solution Approach 1:
A flux guide structure acts as an intermediary between the media facing surface and the recessed sensor. This flux guide conducts magnetic flux from the tape medium to the sensor, maintaining effective flux coupling while allowing the sensor to remain recessed for electrical short protection
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 proposed design significantly reduces the probability of electrical shorts and enhances the sensitivity of CPP reader transducers by stabilizing the soft bias layer and maintaining sufficient signal flux for accurate data reading, improving tape head functionality and data retrieval reliability.
Implementation Method 1
A nonmagnetic exchange break layer is positioned above the sensor and the flux guide for magnetically decoupling the sensor and the flux guide from the stabilization layer
Implementation Method 2
A flux guide extends from the media facing surface toward the sensor
Implementation Method 3
A soft bias layer is positioned on opposite sides of the sensor in a cross-track direction
Implementation Method 4
A stabilization layer is located above the sensor, flux guide and soft bias layer for stabilizing the soft bias layer
Data Source
AI summary
An apparatus, in accordance with one aspect of the present invention, includes a module having a media facing surface. The module comprises the following components. A sensor is recessed from the media facing surface. A flux guide extends from the media facing surface toward the sensor. A soft bias layer is positioned on opposite sides of the sensor in a cross-track direction. A stabilization layer is located above the sensor, flux guide and soft bias layer for stabilizing the soft bias layer. A nonmagnetic exchange break layer is positioned above the sensor and the flux guide for magnetically decoupling the sensor and the flux guide from the stabilization layer.