Electrical Lapping Guide for HAMR Slider Dimensional Control
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Solution Overview
Problem
The lap-and-look lapping process in Heat Assisted Magnetic Recording (HAMR) devices lacks precision in controlling the dimension between the waveguide and the back side surface of the slider, affecting the consistent coupling of the laser to the waveguide, which is crucial for optimal heat generation and data writing.
Innovation Solution
A closed-loop electrical lapping guide (ELG) system is introduced, where a conductive material between terminals on the slider bar increases resistance during lapping, allowing for precise monitoring and termination when a predetermined resistance value is reached, ensuring accurate dimension control and proper laser coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional lap-and-look lapping process is used on the back side of the slider, then the manufacturing process is simple, but the dimensional control precision between the waveguide and back side surface is insufficient
Solution Approach 1:
The patent implements a closed-loop feedback control system by integrating an electrical lapping guide (ELG) with conductive material that provides real-time resistance measurements during the lapping process. The resistance value serves as feedback indicating the dimensional relationship between the waveguide and back side surface, allowing the lapping process to be dynamically adjusted to achieve precise dimensional control (within ±1 micrometer) while maintaining process simplicity through automated monitoring and control.
2Manufacturing precision
If the lapping process is extended to achieve better dimensional control, then the manufacturing precision improves, but the lapping time and productivity decrease
Solution Approach 1:
The electrical lapping guide provides real-time resistance feedback during lapping, enabling the process to reach the precise dimensional target (±1 micrometer) exactly when the predetermined resistance value is achieved. This prevents both under-lapping (requiring additional processing time) and over-lapping (wasting time on unnecessary processing), thereby optimizing productivity while maintaining high dimensional control precision.
Solution Approach 2:
The conductive material is pre-configured in the electrical lapping guide with predetermined resistance characteristics that correspond to the target dimensional relationship between the waveguide and back side surface. This preliminary setup allows the lapping process to automatically terminate at the precise moment the target dimension is reached, eliminating the need for extended trial-and-error lapping and improving overall productivity.
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 method provides improved precision in lapping the back side surface of the slider, ensuring consistent and optimal coupling of the laser to the waveguide, enhancing the performance of HAMR devices by maintaining precise dimensions and improving data writing capabilities.
Implementation Method 1
a conductive material between terminals on the slider bar increases resistance during lapping, allowing for precise monitoring and termination when a predetermined resistance value is reached
Data Source
AI summary
A slider bar apparatus, and a method for lapping a back side surface of the slider bar, is provided. The slider bar includes a head part and a pair of sliders separated by the head part. Each of the sliders has an air bearing surface (ABS) and a back side surface opposite the ABS. Each of the sliders has a reader element and a writer element of a magnetic head for use in a magnetic hard disk drive. An electrical lapping guide is mounted on the back side surface and has a pair of terminals and a conductive material extending between the terminals. The conductive material is arranged on the slider bar such that the resistance between the terminals increases during a lapping of the back side of the sliders.