Glass Spacer Surface Resistivity Control for HDD Static Management
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Solution Overview
Problem
In hard disk drive apparatuses, the use of metallic spacers leads to thermal expansion differences with glass magnetic disks, causing magnetic head floatation issues and static electricity accumulation, which can result in broken recording or reproducing elements due to foreign matter adsorption.
Innovation Solution
A ring-shaped glass spacer with a surface resistivity of 10^3 to 10^9 Ω/sq, containing oxides like TiO2, Nb2O5, or Bi2O3, and undergoing reduction treatment to enhance conductivity, is used to manage static electricity and prevent foreign matter adsorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If glass spacers are used to match thermal expansion with glass magnetic disks, then thermal expansion compatibility is improved, but static electricity accumulation occurs due to glass being an insulator
Solution Approach 1:
The surface resistivity of the glass spacer is controlled within a specific range (10^8 to 10^12 Ω/sq) through compositional adjustments (adding metal oxides like Ti, Nb, Bi) and thermal treatment (reduction treatment at 400-600°C). This parameter optimization allows the glass spacer to maintain thermal expansion compatibility while achieving sufficient conductivity to prevent static electricity accumulation.
2Object-generated harmful factors
If conductive coating is formed on spacer surface using general electroless plating, then static electricity discharge is improved, but adhesiveness is insufficient and dust generation increases
Solution Approach 1:
Instead of using general electroless plating, the invention forms a conductive layer by controlling the surface resistivity of the glass spacer itself through compositional modification (adding metal oxides) and thermal reduction treatment. This approach creates a conductive glass surface with proper adhesiveness and minimal dust generation, avoiding the problems of coating delamination and dust particles associated with conventional plating methods.
3Quantity of substance
If number of magnetic disks is increased to satisfy storage capacity demand, then storage capacity is improved, but static electricity discharge risk and foreign matter adsorption increase
Solution Approach 1:
The invention optimizes the surface resistivity parameter of the glass spacer to a specific range (10^8 to 10^12 Ω/sq) that provides sufficient conductivity to prevent static electricity accumulation. This allows the system to safely accommodate increased numbers of magnetic disks for higher storage capacity while maintaining control over static electricity discharge and foreign matter adsorption risks.
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 glass spacer effectively suppresses static electricity discharge and foreign matter adsorption, ensuring stable operation of the magnetic heads and increased storage capacity in HDD apparatuses.
Implementation Method 1
reducing a surface resistivity of a surface of the glass spacer blank by performing reduction treatment on the surface
Data Source
AI summary
A ring-shaped glass spacer is configured to be arranged in contact with a magnetic disk in a hard disk drive apparatus. A surface resistivity of a surface of a glass material of the glass spacer at 22 (° C.) is lower than a surface resistivity of an inner portion of the glass material at 22 (° C.).