Cross-Track Current Design for Energy-Assisted Magnetic Recording
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic recording heads in hard disk drives face issues with localized heating due to increased current flow, leading to degradation and reduced reliability, as well as limited writing fields when currents are lowered.
Innovation Solution
A magnetic recording device design featuring a main pole between trailing and leading shields, with a hot seed layer and insulation layers that direct current flow in a cross-track direction across the main pole, reducing heat dissipation into shields and enhancing writing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If current is increased to improve writing fields, then writing performance is improved, but localized heating issues occur causing degradation at the media facing surface
Solution Approach 1:
An insulation layer is introduced as an intermediary component between the trailing shield and the hot seed layer. This insulation layer acts as a thermal barrier that prevents direct heat conduction from the high-current region to the media facing surface, while still allowing the current to flow through the spin torque oscillator stack to generate the required writing field.
Solution Approach 2:
The trailing shield structure is segmented by introducing an insulation layer that divides the thermal pathway. The insulation layer creates a distinct thermal zone that separates the heat-generating current path from the temperature-sensitive media facing surface, allowing independent optimization of current flow and thermal management.
2Temperature
If current is lowered to reduce heating, then temperature issues are reduced, but writing fields are limited
Solution Approach 1:
The insulation layer serves as a thermal mediator that decouples the relationship between current magnitude and head temperature. This allows the system to maintain higher currents for strong writing fields while the insulation layer absorbs and blocks the thermal effects, preventing temperature rise at the media facing surface.
3Power
If shields are added around main pole to improve flux gradient, then pole tip field is improved, but device complexity increases
Solution Approach 1:
The trailing shield is given multiple functions: it continues to provide flux conduction and pole tip field enhancement, while also serving as a mounting structure for the insulation layer. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while still achieving the desired flux gradient improvement.
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 design improves write head saturation and reduces write field jitter while maintaining reliability by efficiently managing current flow and heat distribution.
Implementation Method 1
The first and second insulation layers direct the current through the side shields and across the main pole in a cross-track direction
Implementation Method 2
A hot seed layer is disposed between the trailing gap and the trailing shield
Data Source
AI summary
The present disclosure is generally related to a magnetic recording device comprising a magnetic recording head having a current flow in a cross-track direction around a main pole. The magnetic recording device comprises a main pole disposed between a trailing shield, a leading shield, and side shields. A trailing gap is disposed between the main pole and the trailing shield. A hot seed layer is disposed between the trailing gap and the trailing shield. A first insulation layer is disposed between the hot seed layer and the trailing shield, where the first insulation layer contacts the side shields. A second insulation layer is disposed between the main pole and leading shield, where the second insulation layer contacts the side shields. The first and second insulation layers direct the current through the side shields and across the main pole in a cross-track direction.