US 6,651,192 B1Granted

Method and system for testing reliability attributes in disk drives

AssigneeWestern Digital Technologies, Inc.

InventorsJoseph M. Viglione, Yvonne M. Utzig

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Abstract

A system and method for manufacturing disk drives, the disk drives having reliability attributes and manufacturing attributes, the manufacturing attributes comprising process or component manufacturing attributes is disclosed. The reliability attributes comprise measurements for predicting future reliability of the disk drives at the time of manufacture. The disk drives are prepared with a servo format. Each disk drive is connected to a test apparatus and then tuned to verify that each disk drive performs within expected limits. One or more technical screen tests are performed on all of the disk drives. A first sample set of the disk drives is selected automatically at a defined size using a randomizer. One or more extended tests are executed on the first sample set of disk drives to measure a margin magnitude for one or more of the reliability attributes. The margin magnitude is compared with a reference to detect a significant change. If a significant change in the margin magnitude from the reference is detected, then the defined sample size is adjusted. A second sample set of the disk drives is selected according to the adjusted sample size using the randomizer. The extended tests are then repeated on the second sample set to validate the significant change.

Claims11

Dependent claims

A system for testing reliability attributes in disk drives, the reliability attributes comprising measurements for predicting future reliability of the disk drives at the time of manufacture, the disk drives having reliability attributes and manufacturing attributes, the manufacturing attributes comprising process or component manufacturing attributes, the system comprising:

a servo formatter for preparing each disk drive with a servo format;
a test apparatus to which each disk drive is connectable;
a calibrator for tuning each disk drive connected to the test apparatus for verifying that each disk drive performs within expected limits;
a test containment logic for performing one or more technical screen tests on each disk drive;
an extended testing logic included with the test apparatus for executing one or more extended tests on a first sample set of disk drives for measuring a margin magnitude for one or more of the reliability attributes;
the extended testing logic further for receiving selections of a first sample set of disk drives from a randomizer that automatically selects a first sample set of the disk drives, the first sample set having a defined size;
the one or more extended tests for detecting a significant change in the margin magnitude from a reference;
the extended testing logic further for automatically adjusting the defined size, and providing the adjusted defined size to the randomizer,
the extended testing logic further for receiving selections of a second sample set of the disk drives from the randomizer, the second sample set having the adjusted defined size;
and
the extended testing logic further for repeating the extended tests on the second sample set to validate the significant change.

8 more elements

In a system for manufacturing disk drives, the disk drives having reliability attributes and manufacturing attributes, the manufacturing attributes comprising process or component manufacturing attributes;

a method for testing the reliability attributes, the reliability attributes comprising measurements for predicting future reliability of the disk drives at the time of manufacture, the method comprising the steps of:
preparing each disk drive with a servo format;
connecting each disk drive to a test apparatus;
tuning each disk drive connected to the test apparatus to verify that each disk drive performs within expected limits;
performing one or more technical screen tests on each disk drive;
receiving selections in a first sample set of the disk drives automatically selected by a randomizer, the first sample set having a defined size;
executing one or more extended tests on the first sample set of disk drives to measure a margin magnitude for one or more of the reliability attributes;
detecting a significant change in the margin magnitude from a reference;
and
automatically adjusting the defined size,
providing the adjusted defined size to the randomizer,
receiving selections in a second sample set of the disk drives automatically selected by the randomizer, the second sample set having the adjusted defined size;
and
repeating the extended tests on the second sample set to validate the significant change.

11 more elements

Dependencies are inferred from the claim text.