Method for reducing surface particle shedding

Abstract

A method for reducing surface particle shedding of a material, specifically a suspension mounting arm for a hard disk drive, made of an alloy such as 300 Series stainless steel, by thermally conditioning the mounting arm for a desirable time period sufficient to reduce residual stress in the mounting arm while substantially maintaining its original yield strength characteristics. To ensure fabrication free from oxidation and contamination, the contained heat source can be oxygen depleted by evacuating the interior of the container to a sub-atmospheric pressure or by filling the interior of with an inert gas such as argon or a reducing gas, such as hydrogen. After thermal exposure, the material is cooled to an ambient temperature. The resulting material exhibits adequate stiffness and yield strength for assembly and operation in a hard disk drive.

Description

FIELD OF THE INVENTION[0001]The invention relates generally to a method for treating stainless steel components to reduce surface particle shedding while maintaining functional stiffness. More particularly, the invention relates to a method for treating stainless steel used for hard disk drive suspension mounting arms.DESCRIPTION OF THE RELATED ART[0002]A key component of any computer system is a device to store data. One common place for storing massive amounts of data in a computer system is on a hard disk drive (HDD). The most basic parts of a disc drive are a disc that is rotated, an actuator structure that moves a transducer to various locations on the disc, and electrical circuitry that is used to write and read data to and from the disc. There are a variety of disc drives in use today, such as hard disc drives, zip drives, floppy disc drives. All utilize either rotary or linear actuators.[0003]In hard disk drives, magnetic heads read and write data on the surfaces of rotating...

AI Technical Summary

Benefits of technology

[0010]The invention is directed to a method for thermally conditioning stainless steel mounting arms so that the material is softened, thereby reducing or relieving the residual stress that aids in surface particle shedding. The method of the invention thermally conditions a mounting arm in an oven or furnace at a temperature and duration sufficient to anneal the outer surface of the mounting arm. The temperature is maintained between approximately 600° F. and 1850° F. The oven environment can be oxygen depleted and/or filled with an inert or

Problems solved by technology

Because there is relative motion between the disk surface and the magnetic head due to the disk rotation and head actuation, continuous contact between the head and disk can lead to tribological failure of the interface.

Such tribological failure, known colloquially as a “head crash,” can damage the disk and head and cause data loss.

Despite these design considerations, tribological failures may still occur due to mounting arm resonance from air fluid turbulence, sudden shocks from being dropped, and debris and contamination from the environment.

The resulting temporary increase in head-disk spacing can cause read / write errors-limit the activation speeds and achievable tracks per inch (TPI) on the disk, and cause data loss.

This creates defects on the disk that may result in a head crash.

The fallacy of this approach is that the material continues to shed particles aided by the build up of stress near the surface.

The industry's marked reliance on post-assembly cleaning steps has increased even though such steps are impractical in high volume production.

Assembly in clean environments does not prevent the generation of contaminants and debris during assembly operations performed within those clean environments; nor does it reduce surface particle shedding of the mounting arm structure during operation.

Prior art attempts have focused on pre- and post-assembly cleaning, but have not addressed this cause for increased shedding.

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