Asymmetric Shield Footprints for TDMR Sensor Isolation
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Solution Overview
Problem
Conventional magnetic recording transducers face challenges in achieving adequate performance at higher recording densities, particularly with two-dimensional magnetic recording (TDMR) due to skew angle issues and electrical connection difficulties, which affect the alignment and efficiency of read sensors.
Innovation Solution
The design incorporates multiple read sensors with asymmetric shield layers and insulating layers to reduce capacitive coupling, allowing for improved electrical isolation and alignment, thereby addressing skew issues and enhancing performance across various skew angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple read sensors are used in TDMR configuration, then recording density is improved, but skew angle alignment issues worsen
Solution Approach 1:
The shield layers are designed with different footprints for different sensors. Specifically, the first shield layer has a different footprint than the second shield layer, allowing each shield to be optimized for its corresponding sensor's alignment requirements. This local differentiation enables the system to accommodate varying skew angles while maintaining precise sensor alignment for high-density recording.
2Ease of manufacture
If shield layers with same footprint are used, then manufacturing is simplified, but capacitive coupling and cross-talk increase
Solution Approach 1:
Different shield layers are assigned different footprints to reduce capacitive coupling. The first shield layer extends further in the cross-track direction than the second shield layer, creating spatial separation that minimizes parasitic capacitance between adjacent shields while maintaining magnetic shielding effectiveness.
Solution Approach 2:
The shield layers employ asymmetric footprint designs rather than symmetric identical footprints. By making the first and second shield layers have different dimensional extensions, the design breaks symmetry to reduce capacitive coupling and cross-talk between sensors, thereby improving signal integrity without significantly complicating the fabrication process.
3Productivity
If outer read sensors are positioned for maximum recording density, then productivity is improved, but performance degrades at nonzero skew angles
Solution Approach 1:
Each shield layer is customized with a specific footprint designed for its corresponding sensor's operational requirements. This local optimization allows outer read sensors to be positioned for maximum recording density while the asymmetric shield design compensates for skew angle effects, maintaining reliable sensor performance across varying disk positions.
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 the magnetic recording transducer's performance by reducing capacitive coupling and cross-talk, enabling higher recording densities and frequency performance while maintaining alignment and electrical isolation of sensors.
Implementation Method 1
The shields 130 and 140 may be configured to have different footprints. More specifically, the footprints of the shield layers 132, 136 overlap by not more than fifty percent of the footprint of each shield layer 132, 136
Data Source
AI summary
A method and system provide a magnetic transducer having an air-bearing surface (ABS) and including first and second read sensors and a shield. The shield is in a down track direction from the first read sensor and between the first and second read sensors. The shield includes a first shield layer, a second shield layer and an insulating layer between the first and second shield layers. The first shield layer is between the first read sensor and the second shield layer. The second shield layer is between the first shield layer and the second read sensor. The first shield layer has a first footprint. The second shield layer has a second footprint. The second shield layer overlaps the first shield layer in the down track direction. The overlap is not more than fifty percent of the first footprint and not more than fifty percent of the second footprint.