Magnetic Head Gap Layers with Different Permeabilities
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Solution Overview
Problem
The recording resolution and recording density of magnetic heads are adversely affected due to magnetic saturation of the write shield as the gap length between the main magnetic pole and the shield decreases, limiting the ability to increase recording density.
Innovation Solution
Incorporating a first layer with a smaller magnetic relative permeability and a second layer with a larger magnetic relative permeability in the gaps between the main magnetic pole and the shields, allowing for controlled magnetic flux distribution and preventing shield saturation, thereby enhancing recording density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the gap length between the main magnetic pole and the shield is decreased to improve recording density, then recording density is improved, but the write shield becomes magnetically saturated and loses its shielding function
Solution Approach 1:
The patent applies local quality by introducing a magnetic flux releasing layer with specific magnetic permeability characteristics at the gap region between the main magnetic pole and shields. This localized modification allows different regions of the magnetic head to have different magnetic properties: the gap region releases magnetic flux to prevent shield saturation, while other regions maintain their original shielding functionality. This resolves the contradiction by enabling high recording density (small gap) without compromising the shielding function.
Solution Approach 2:
The patent changes the magnetic permeability parameter by introducing a magnetic flux releasing layer with controlled magnetic permeability (μr) between the main magnetic pole and shields. By adjusting this parameter, the patent optimizes the magnetic flux distribution to prevent shield saturation while maintaining effective shielding. This parameter change enables the system to achieve both high recording density and reliable shielding function simultaneously.
2Measurement precision
If the gap length is decreased to improve recording resolution, then recording resolution is improved, but magnetic saturation occurs in the shield reducing recording performance
Solution Approach 1:
The magnetic flux releasing layer is locally positioned in the gap region to specifically address the magnetic flux concentration problem at this critical location. This localized intervention allows the shield to remain unsaturated while maintaining the small gap length required for high recording resolution, thereby preserving overall recording performance.
Solution Approach 2:
The magnetic flux releasing layer acts as an intermediary element between the main magnetic pole and the shields. It mediates the magnetic flux distribution by providing a controlled path for flux release, preventing direct flux concentration in the shields. This intermediary structure enables both high recording resolution (through small gap) and sustained recording performance (by preventing saturation).
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 maintains the functionality of the write shield as a magnetic shield while improving recording density even when the write gap becomes narrow, preventing magnetic saturation and sustaining high recording performance.
Implementation Method 1
a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap
Implementation Method 2
preventing shield saturation, thereby enhancing recording density
Data Source
AI summary
A magnetic head includes a main magnetic pole, a write shield separated from the main magnetic pole by a write gap, a first side shield that is separated from the main magnetic pole by a first side gap, a second side shield that is separated from the main magnetic pole by a second side gap, a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein the first magnetic relative permeability is smaller than the second magnetic relative permeability.