Slider Manufacturing Magnetic Field Lapping
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Solution Overview
Problem
Conventional manufacturing methods for sliders in hard disk drives often result in magnetic head performance degradation due to local high temperatures generated during the lapping process, which can disorder the magnetic moment directions of AFM materials and hard magnets, leading to instability and reduced functionality.
Innovation Solution
A manufacturing method and apparatus that apply controlled magnetic fields during the lapping and cutting processes to maintain the magnetic moment directions of the read head components, using magnetic fields with specific orientations to counteract the effects of temperature-induced disordering, ensuring the stability and ideal orientation of the TMR element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lapping process is used to adjust element height, then manufacturing precision is improved, but local high temperature is generated causing magnetic moment direction disordering
Solution Approach 1:
A magnetic field applying device is introduced as an intermediary during the lapping process. This device generates a magnetic field that acts as a protective mediator, preventing the harmful effect of temperature-induced magnetic moment disordering while allowing the lapping process to proceed for precision height adjustment.
Solution Approach 2:
The magnetic field is applied in advance during the lapping process to counteract the potential harmful effect of temperature rise. By establishing the magnetic field before and during the heating process, the patent prevents magnetic moment disordering from occurring in the first place, rather than addressing it after the fact.
2Reliability
If AFM materials and hard magnets are used in read head, then reading performance is improved, but magnetic stability is reduced due to temperature sensitivity
Solution Approach 1:
The magnetic field applying device serves as a protective intermediary that shields the temperature-sensitive AFM materials and hard magnets from thermal disturbances during manufacturing. This allows the read head to maintain its high reading performance while protecting the magnetic components from temperature-induced instability.
Solution Approach 2:
The magnetic field is applied beforehand during the manufacturing process to cushion or protect against the harmful thermal effects. This preliminary protective measure ensures that the magnetic moment directions remain stable during the entire manufacturing cycle, preventing degradation of magnetic stability.
3Manufacturing precision
If lapping process is performed to achieve predetermined requirement, then manufacturing precision is improved, but magnetic head performance is degraded due to temperature effects
Solution Approach 1:
The magnetic field applying device is introduced as a protective intermediary during the lapping process. It allows the process to achieve precise air bearing surface requirements while simultaneously protecting the magnetic head components from temperature-induced performance degradation, thus resolving the contradiction between precision and performance.
Solution Approach 2:
The magnetic field is applied in advance during the lapping process to counteract the harmful thermal effects before they can degrade magnetic head performance. This preliminary protective action enables precise manufacturing without sacrificing reliability.
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 controlled magnetic fields effectively maintain the magnetic moment directions of the read head components, enhancing the reading performance and stability of the slider by preventing disordering caused by high temperatures during the manufacturing process.
Implementation Method 1
applying a first magnetic field with a first direction during lapping the air bearing surface, and the first direction being parallel to the air bearing surface and the bonding surface
Data Source
AI summary
A manufacturing method of a slider includes steps of (a) providing a row bar with a plurality of slider elements connecting together, the row bar having an air bearing surface, a back surface opposite the air bearing surface, a bonding surface and a bottom surface opposite the bonding surface; (b) grinding the bottom surface of the row bar; (c) lapping the air bearing surface of the row bar so as to obtain a predetermined requirement, and applying a first magnetic field with a first direction during lapping the air bearing surface, and the first direction being parallel to the air bearing surface and the bonding surface; and (d) cutting the row bar into a plurality of individual sliders. The present invention can maintain a good performance of a magnetic head during the manufacturing process.