Feedthrough Mounting Structure for Magnetic Disk Sealing
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Solution Overview
Problem
The existing magnetic disk devices face challenges with air turbulence and windage loss due to high-speed rotation, leading to vibration, noise, and increased power consumption, and helium leakage from hermetically sealed devices due to inadequate sealing materials and structures.
Innovation Solution
A magnetic disk device with a feedthrough mounting structure where the flange is larger than the opening, bonded from the outside, using a glass or ceramic sealing material, and positioned closer to the device's exterior to enhance bonding reliability and reduce stress from external forces and temperature changes, thereby improving sealing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solder is used for bonding the feedthrough to the base, then bonding is achieved, but bonding reliability is insufficient under external force and temperature changes
Solution Approach 1:
The patent uses a composite bonding approach combining glass sealing material (for hermetic sealing) with solder (for electrical connection). The glass material provides high strength and reliability under external forces and temperature changes, while the solder ensures electrical conductivity. This composite material strategy resolves the contradiction by leveraging the complementary properties of different materials.
Solution Approach 2:
The bonding function is segmented into two distinct parts: hermetic sealing (achieved by glass material) and electrical connection (achieved by solder). This segmentation allows each material to optimize its performance for its specific function, with the glass material providing mechanical strength and reliability while the solder provides electrical connectivity.
2Reliability
If the feedthrough is bonded from the inside of the device, then bonding is achieved, but bonding reliability decreases under external force
Solution Approach 1:
The patent inverts the conventional bonding approach by bonding the feedthrough from the outside of the device rather than from the inside. This inversion allows the bonding to better withstand external forces applied to the device, as the bonding structure is positioned to directly resist the direction of applied loads, thereby improving reliability.
3Use of energy by moving object
If air is used in the magnetic disk device, then conventional operation is maintained, but turbulence and windage loss increase power consumption
Solution Approach 1:
The patent changes the physical parameter of the gas environment by replacing air with a vacuum (or low-density gas). This parameter change eliminates air turbulence and windage loss, thereby reducing power consumption and energy loss during high-speed disk rotation, while maintaining the operational functionality of the magnetic disk device.
4Use of energy by moving object
If helium is sealed in the device to reduce turbulence and windage loss, then power consumption decreases, but helium leakage occurs due to inadequate hermetic sealing
Solution Approach 1:
The patent employs composite sealing materials including glass sealing material and solder to create a hermetic seal that prevents helium leakage. The glass material provides excellent hermetic properties due to its low permeability to helium atoms, while the solder ensures mechanical bonding and electrical connectivity, together achieving both low power consumption and high sealing reliability.
Solution Approach 2:
The glass sealing material acts as an intermediary barrier between the helium gas and the external environment. This intermediary layer with excellent hermetic properties prevents helium diffusion and leakage, enabling the device to maintain vacuum or low-density gas environment for reduced power consumption while ensuring long-term 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
This configuration enhances bonding reliability, reduces power consumption, enables accurate and quiet positioning, and maintains a hermetic seal, even under external forces and temperature variations, allowing for efficient helium retention and reduced noise.
Implementation Method 1
fixed to the flange 4 by a glass sealing material 44
Implementation Method 2
helium readily leaks out during use from a housing used in an ordinary magnetic disk device inferior in hermetic
Implementation Method 3
a certain amount of air turbulence, thereby producing vibration in the disk and head gimbal assembly
Implementation Method 4
air away from the disk is stationary, generating a shearing force therebetween which turns into a load to stop the rotation of the disk. This is referred to as 'windage loss'
Implementation Method 5
positioned closer to the device's exterior to enhance bonding reliability and reduce stress from external forces and temperature changes
Data Source
AI summary
Embodiments in accordance with the present invention improve bonding reliability in a feedthrough sealing portion. According to one embodiment of the present invention, an opening of a through hole is provided on the bottom of the base of the magnetic disk device and a feedthrough mounting plane which is one of the steps formed toward the outside of the device is provided around the opening. The feedthrough includes a flange and pins which are fixed to the flange by a glass material and pass an electric signal. The flange is larger in outer shape than the opening of the base. The periphery of the flange of the feedthrough is mounted on the feedthrough mounting plane of the base from the outside and bonded thereto by solder.