Slider Manufacturing Cooling During Lapping
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Solution Overview
Problem
Conventional manufacturing methods for sliders in hard disk drives generate local high temperatures during lapping, which affect the magnetic moment directions and stability of AFM materials, hard magnets, and free layers, leading to unstable magnetic heads and poor reading performance.
Innovation Solution
A manufacturing method and apparatus that involve lowering the temperature of lapping surfaces and the lapping medium to maintain the magnetic moment directions and reduce thermal noise, using a lapping machine, cooling device, and cutting machine to control temperatures between 0° C. and 15° C. during the lapping and grinding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional lapping process is used to flatten the air bearing surface, then manufacturing efficiency is improved, but local high temperature is generated which disorders magnetic moment directions and reduces reading performance
Solution Approach 1:
The patent changes the temperature parameter during lapping by introducing a cooling device that cools the lapping surface. This parameter change prevents the generation of local high temperature, thereby avoiding the disordering of magnetic moment directions in the read head and maintaining stable reading performance while still achieving efficient manufacturing
Solution Approach 2:
The patent introduces a cooling device as an intermediary element between the lapping plate and the row bar. This cooling device acts as a mediator to remove heat generated during lapping, preventing thermal damage to the magnetic head components while allowing the lapping process to continue at high efficiency
2Manufacturing precision
If lapping pressure is increased to improve surface finish, then manufacturing precision is improved, but thermal noise increases and magnetic head stability deteriorates
Solution Approach 1:
The patent changes the temperature parameter by introducing active cooling during lapping. This allows the lapping process to be performed with higher pressure and better surface finish while the cooling device simultaneously removes the generated heat, preventing thermal noise and maintaining magnetic head stability
3Device complexity
If lapping process is performed at room temperature, then process simplicity is maintained, but magnetic moment directions become disordered and yield of high-quality sliders decreases
Solution Approach 1:
The patent changes the temperature parameter from room temperature to controlled low temperature during lapping. By introducing a cooling device, the process maintains simplicity while significantly improving the yield of high-quality sliders through prevention of magnetic moment direction disordering
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 stabilizes the magnetic heads by preventing disordering of magnetic moment directions and reducing thermal noise, resulting in improved reading performance and increased yield of high-quality sliders with reduced noise and hysteresis.
Implementation Method 1
lowering the temperature of lapping surfaces and the lapping medium to maintain the magnetic moment directions and reduce thermal noise
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; (b) lapping surfaces of the row bar so as to obtain a predetermined requirement; (c) lowering the temperature of the surfaces lapped in the step (b) before and/or during lapping; and (d) cutting the row bar into a plurality of sliders. The present invention can prevent a local high temperature generated on the magnetic head during lapping so that the performance of the magnetic head is improved.