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Low-Impedence Filter and Actuator Restrictor Plate for 10.8 Inch DASD

IP.com Disclosure Number: IPCOM000115780D
Original Publication Date: 1995-Jun-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Shi, E: AUTHOR

Abstract

A process is disclosed for achieving particle contamination requirements for a 10.8 inch Data Access Storage Device (DASD) having a closed loop air flow system.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Low-Impedence Filter and Actuator Restrictor Plate for 10.8 Inch DASD

      A process is disclosed for achieving particle contamination
requirements for a 10.8 inch Data Access Storage Device (DASD) having
a closed loop air flow system.

      In a 10.8 inch Head Disk Assembly (HDA) that has a linear
actuator assembly partitioned from the disk area, backflow
performance is one key parameter that is used as a criterion during
the development of the HDA to determine whether or not there is a
high risk of contamination migration (counter to normal air flow
direction) from the actuator area into the disk area.

      The contaminants of concern are those which are generated by
the actuator bearing riding on the actuator rail during seek
operations.  The design objective is to limit the migration of
contaminants from the actuator into the disk enclosure.  A measure
that is used to determine whether or not a given air system design is
prone to backflow contamination is the backflow ratio.  In addition,
actuator contaminant generation rates during seek operations are used
for comparison against a given design backflow ratio to make this
exposure assessment.

      Ideally, a given air system design backflow ratio should be
high enough such that, statistically speaking, the probability of
disk area contamination from actuator contaminant backflow is within
3 to 6 sigma levels.  These levels are estimated from experiments
performed with representative (production...