Magnetic Head Substructure Manufacturing with Resistance-Based Pole Layer Control
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Solution Overview
Problem
Conventional methods of manufacturing magnetic heads face challenges in reducing variations in resistance and neck height, which affect write characteristics, especially as recording density increases, due to variations in resistance-area product and width of magnetoresistive films.
Innovation Solution
The method involves forming a magnetic head substructure with precise control over the boundary between the track width defining portion and the wide portion of the pole layer by detecting the resistance of magnetoresistive films and using this information to align the pole layer accurately, ensuring uniform resistance and neck height through targeted lapping processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing methods are used to form magnetic heads, then production efficiency is maintained, but variations in resistance and neck height increase, affecting write characteristics
Solution Approach 1:
The method performs preliminary detection of resistance-area product and width of magnetoresistive films before forming the pole layer. Based on these detection results, the boundary position between the track width defining portion and wide portion is determined in advance, allowing the pole layer to be formed with precise control over neck height. This preliminary action eliminates the need for complex post-forming adjustments.
Solution Approach 2:
The manufacturing method implements feedback control by detecting the resistance-area product and width of magnetoresistive films, then using this information to determine the boundary position of the pole layer. This closed-loop approach ensures that variations in magnetoresistive film properties are compensated for, achieving uniform neck height and resistance across different heads.
2Manufacturing precision
If the boundary position between track width defining portion and wide portion is not precisely controlled, then manufacturing is simpler, but variations in neck height increase, degrading write characteristics
Solution Approach 1:
The method determines the boundary position between the track width defining portion and wide portion in advance, based on detected values of resistance-area product and width of magnetoresistive films. This preliminary determination allows for precise control of neck height during pole layer formation without requiring complex real-time measurement systems.
Solution Approach 2:
The method changes the boundary position parameter of the pole layer based on detected variations in magnetoresistive film properties. By adjusting this parameter according to actual measurements, the system compensates for film variations and achieves uniform neck height across different magnetic heads.
3Manufacturing precision
If variations in resistance-area product and width of magnetoresistive films are not accounted for, then manufacturing process is simpler, but variations in resistance increase, affecting read characteristics
Solution Approach 1:
The method implements feedback control by detecting the resistance-area product and width of magnetoresistive films, then using this information to determine the boundary position of the pole layer. This closed-loop approach ensures that variations in magnetoresistive film properties are compensated for, achieving uniform resistance across different heads.
Solution Approach 2:
The method changes the boundary position parameter based on detected variations in resistance-area product and width. By adjusting this parameter according to actual measurements, the system compensates for film variations and achieves uniform resistance characteristics.
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 approach effectively reduces variations in both the resistance of the magnetoresistive element and the neck height of the pole layer, enhancing the accuracy and consistency of write characteristics in magnetic recording systems.
Implementation Method 1
GMR (giant magnetoresistive) elements utilizing a giant magnetoresistive effect
Implementation Method 2
TMR elements utilizing a tunneling magnetoresistive effect
Implementation Method 3
a coil for generating a magnetic field corresponding to data to be written on a recording medium, and a pole layer for allowing a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough
Data Source
AI summary
A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.