Trapezoidal Spin-Torque Oscillator for Magnetic Recording Head
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic recording heads face challenges in achieving higher recording density and stable recording/reproduction characteristics due to the degradation of high-frequency oscillators when increased drive current is required to apply a high-frequency magnetic field to a smaller region.
Innovation Solution
A magnetic recording head design featuring a spin-torque oscillator with a trapezoidal shape, where the length of the lower end surface is longer than the upper end surface, allowing for increased high-frequency magnetic field density and reduced drive current, thereby improving recording density and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a higher drive current is supplied to the high-frequency oscillator to apply the high-frequency magnetic field to a smaller region and increase the field intensity, then the recording density and field intensity are improved, but the oscillator is gradually degraded and recording/reproduction stability deteriorates
Solution Approach 1:
The patent applies local quality by creating a non-uniform current density distribution within the oscillator structure. The current density is concentrated in specific regions (particularly near the pole tip) rather than being uniformly distributed, which allows the high-frequency magnetic field to be applied more intensely to a smaller recording region while reducing the total drive current required. This localized current concentration improves recording density without causing excessive oscillator degradation
Solution Approach 2:
The patent changes physical parameters of the oscillator structure, including the shape (trapezoidal cross-section), size, and material composition. By optimizing these parameters, the oscillator generates a more concentrated high-frequency magnetic field with higher intensity in the recording region, achieving improved recording density while maintaining stability at lower drive currents
2Manufacturing precision
If the high-frequency magnetic field is applied to a smaller region to achieve higher recording density, then the recording density is improved, but the drive current must be increased which causes oscillator degradation
Solution Approach 1:
The oscillator structure is designed with local quality variations, featuring a trapezoidal cross-section where the width varies along the length. This creates localized regions of different current density and magnetic field strength, concentrating the high-frequency field where needed for high-density recording while reducing the overall current requirement compared to a uniform structure
Solution Approach 2:
The patent introduces dimensional variation in the oscillator cross-section (trapezoidal shape with different widths at top and bottom), adding geometric complexity in one dimension to achieve better field concentration. This dimensional change allows the field to be focused on a smaller recording region without requiring proportionally higher drive current
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 trapezoidal spin-torque oscillator enhances high-frequency magnetic field density, enabling higher-density magnetic recording while reducing the need for increased drive current, thus maintaining stable recording/reproduction characteristics.
Implementation Method 1
a spin-torque oscillator for use as a high-frequency oscillator is disposed between the main pole and trailing shield such that a high-frequency magnetic field from the oscillator is applied to a magnetic recording layer
Data Source
AI summary
According to one embodiment, a magnetic recording head includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, and a high-frequency oscillator disposed adjacent to the main pole and near a air-bearing surface which faces the recording medium. The high-frequency oscillator includes a lower end surface located nearest to the air-bearing surface and an upper end surface located farthest from the air-bearing surface. A length of the lower end surface in a cross track direction is longer than a length of the upper end surface in the cross track direction.