Thin-Film Magnetic Head Conductor Layer for MR Height Control
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Solution Overview
Problem
Conventional electric lapping guides in thin-film magnetic heads are positioned far from the magnetoresistive element, leading to deviations in MR height control, which is critical for high-density magnetic recording, and measuring the resistance value of the magnetoresistive element itself is challenging due to short-circuit risks during lapping.
Innovation Solution
A magnetic head design where a conductor layer acts as an electric lapping guide, positioned close to the magnetism detecting element, allowing precise control of MR height by measuring the resistance value change during lapping, with the upper magnetic shield layer functioning as an electrode to simplify the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electric lapping guides are positioned far from the magnetoresistive element, then the structure is simpler to manufacture, but the MR height control precision deteriorates
Solution Approach 1:
The patent introduces a conductor layer as an intermediary element that serves as the electric lapping guide. This conductor layer is positioned between the magnetoresistive element and the medium-opposing surface, allowing it to be close to the magnetoresistive element for precise MR height control while being structurally distinct and easier to manufacture separately. The conductor layer mediates between the conflicting requirements of proximity for precision and separation for manufacturability.
2Manufacturing precision
If the magnetoresistive element itself is used to measure resistance during lapping, then the MR height control precision improves, but the reliability deteriorates due to short-circuit risks
Solution Approach 1:
The patent extracts the electric lapping guide function from the magnetoresistive element itself and assigns it to a separate conductor layer. This separation allows the magnetoresistive element to maintain its integrity and reliability while the conductor layer performs the resistance measurement function during lapping. The conductor layer is specifically designed to withstand the lapping process without the short-circuit risks that would affect the magnetoresistive element.
3Manufacturing precision
If the conductor layer is positioned close to the magnetism detecting element, then the MR height control precision improves, but the device complexity increases
Solution Approach 1:
The conductor layer is designed to serve multiple functions: it acts as the electric lapping guide for MR height control, provides electrical connection, and forms part of the medium-opposing surface structure. By combining multiple functions into a single element, the patent reduces overall device complexity while maintaining the benefit of close positioning to the magnetoresistive element for precise control.
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 enables precise control of MR height, reducing deviations and ensuring accurate lapping, thereby improving the performance of thin-film magnetic heads for high-density magnetic recording.
Implementation Method 1
the electric resistance value of the electric lapping guides changes according to the amount of polishing. Therefore, measuring changes in the electric resistance value of the electric lapping guides at the time of lapping
Implementation Method 2
a conductor layer, arranged closer to the slider substrate than are the upper magnetic shield layer and electrode layer, extending in the track width direction so as to be in contact with the upper magnetic shield layer and electrode layer
Data Source
AI summary
A magnetic head having precisely controlled MR height has a slider substrate and a magnetic head part provided on the slider substrate. The magnetic head part includes, seeing from a medium-opposing surface side, a magnetism detecting element; an upper magnetic shield layer arranged on the magnetism detecting element; an electrode layer separated in a track width direction from the upper magnetic shield layer; and a conductor layer, arranged closer to the slider substrate than are the upper magnetic shield layer and electrode layer, extending in the track width direction so as to be in contact with the upper magnetic shield layer and electrode layer and forming a part of the medium-opposing surface.