Diamond Cluster Texturing Slurry for Hard Disk Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current texturing methods for magnetic hard disks fail to produce uniform and clear texturing marks with the required average surface roughness and line density, often resulting in product quality fluctuations and spots on the substrate surface.
Innovation Solution
A texturing slurry comprising diamond clusters with specific impurity content and a dispersant, including glycol compounds, higher aliphatic amides, organic phosphates, and surfactants, is used to form texturing marks on a magnetic hard disk substrate, ensuring uniformity and clarity without spots, with an average surface roughness between 3 Å and 6 Å and a line density of 40 lines/μm or greater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional texturing methods are used, then texturing marks can be formed on the substrate surface, but the marks are not uniform and clear, resulting in spots and quality fluctuations
Solution Approach 1:
The patent applies parameter changes by precisely controlling the purity of diamond clusters (95-99%) and the average cluster diameter (30-200 nm). These parameter optimizations enable the formation of uniform texturing marks with line density of 40 lines/μm or greater and average surface roughness of 3-6 Å, eliminating spots and quality fluctuations while maintaining manufacturing precision
Solution Approach 2:
The patent uses composite materials by combining diamond clusters with specific impurity compositions (95-99% diamond purity) and controlled cluster sizes. This composite structure of diamond clusters with optimized composition enables simultaneous achievement of uniformity, clarity, and reliability in texturing marks, resolving the contradiction between manufacturing precision and product quality consistency
2Measurement precision
If the line density is increased to 40 lines/μm or greater for accurate magnetization, then the number of protruding parts per unit area increases, but the texturing marks become difficult to form uniformly and clearly
Solution Approach 1:
The patent resolves this contradiction by changing the parameter of diamond cluster size to an average diameter of 30-200 nm and purity to 95-99%. These parameter changes enable the formation of clear texturing marks even at high line density of 40 lines/μm or greater, maintaining both magnetization accuracy through increased protruding parts and manufacturing precision through uniform mark formation
3Length of stationary object
If the average surface roughness is reduced to 3-6 Å for smooth magnetic head operation, then the surface becomes smoother, but it becomes difficult to form clear texturing marks with high line density
Solution Approach 1:
The patent resolves this contradiction by optimizing the diamond cluster parameters to an average diameter of 30-200 nm and purity of 95-99%. These parameter changes enable the simultaneous achievement of low average surface roughness (3-6 Å) for smooth magnetic head operation and clear texturing marks with high line density (40 lines/μm or greater), as the controlled cluster size and purity provide sufficient contrast and definition even on ultra-smooth surfaces
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 solution enables the formation of uniform and clear texturing marks on magnetic hard disk substrates, achieving the desired surface roughness and line density without spots, thereby ensuring reliable product quality and smooth magnetic head operation.
Implementation Method 1
texturing is conventionally carried out by using free abrading particles, or by supplying slurry having abrading particles dispersed therein to the surface of the substrate and pressing a texturing tape onto the surface of the substrate so as to form approximately concentric circular texturing marks on the substrate surface
Implementation Method 2
texturing slurry comprising diamond clusters with specific impurity content and a dispersant
Data Source
AI summary
Texturing slurry for texturing a substrate for a magnetic hard disk is obtained by dispersing abrading particles of a specified kind in a specified kind of dispersant. The abrading particles include diamond clusters formed with artificial diamond particles with primary particle diameter of 20 nm or less and surrounded by impurities containing chlorine at a certain ratio. The cluster diameter and the average cluster diameter of the diamond clusters are each within a specified range. For texturing a substrate surface, the substrate is rotated, texturing slurry of this invention is supplied to the surface and a texturing tape of a specified kind is pressed against the substrate surface while it is caused to run.