MINIMIZATION OF THERMAL MAGNETORESISTIVE OFFSET CHANGE

• US 20200135232A1
• Filed: 10/29/2018
• Published: 04/30/2020
• Est. Priority Date: 10/29/2018
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: LIU, Xiong, ZHANG, Lihong
• Granted Patent: US 10,839,841 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 33/027 Covers G11B33/022 takes precedence; with means for guiding the record carrier G11B17/34
• CPC Class Codes: G11B 33/121 the apparatus comprising a single recording/reproducing device
• CPC Class Codes: G11B 33/1406 Reducing the influence of the temperature
• CPC Class Codes: G11B 33/1433 by reducing the effects of the thermal expansion
• CPC Class Codes: G11B 5/4833 Structure of the arm assembly, e.g. load beams, flexures, parts of the arm adapted for controlling vertical force on the head G11B5/484 takes precedence
• CPC Class Codes: G11B 5/5565 system adaptation for compensation of variations of physical parameters, e.g. temperature
• CPC Class Codes: G11B 5/59627 Aligning for runout, eccentricity or offset compensation G11B5/5534, G11B5/59677, G11B5/59688 take precedence
• CPC Class Codes: G11B 5/59683 for magnetoresistive heads

Abstract

Provided herein is an apparatus including a disk drive base, wherein the disk drive base includes a first metal composition with a first CTE (“coefficient of thermal expansion”). A disk drive cover is attached to the disk drive base, wherein the disk drive cover includes a second metal composition with a second CTE that are different from the first metal composition and the first CTE. An arm is connected to a reader and a writer, wherein the arm is coupled to the disk drive base, the reader and the writer are separated by a distance, and the distance affects an MR (“magnetoresistive”) offset. In response to temperature changes between 0° C. and 60° C., the first material and the second material expand and contract comparably and proportionally. In further response to the temperature changes between 0° C. and 60° C., a change in the MR offset is less than 10% or a preferably defined range of a track pitch on a recording medium attached to the disk drive base.

Claims

1. An apparatus comprising:

a disk drive base, wherein the disk drive base comprises a first material with a first metal composition with a first CTE (“

coefficient of thermal expansion”

);

a disk drive cover attached to the disk drive base, wherein the disk drive cover includes a second material with a second metal composition with a second CTE that are different from the first metal, the first metal composition, and the first CTE; and

an arm connected to a reader and a writer, wherein

the arm is coupled to the disk drive base,

the reader and the writer are separated by a distance,

the distance affects an MR (“

magnetoresistive”

) offset, and

in response to temperature changes between 0°

C. and 60°

C.,

the first material and the second material expand and contract in equal or substantially equal proportions and scales, and

a change in the MR offset is less than 10% of a track pitch on a recording medium.

2. The apparatus of claim 1, wherein the arm includes a third material with a third CTE, and the third CTE contributes to the change in the MR offset of less than 10% of the track pitch on the recording medium between 0°

C. and 60°

C.

3. The apparatus of claim 1, further comprising a suspension connected to the arm, the reader, and the writer, wherein the suspension includes a fourth material with a fourth CTE, and the fourth CTE contributes to the change in the MR offset of less than 10% of the track pitch on the recording medium between 0°

C. and 60°

C.

4. The apparatus of claim 1, wherein the first metal composition is an aluminum composition.

5. The apparatus of claim 1, wherein the first metal composition includes aluminum-ceramic composites.

6. The apparatus of claim 1, wherein the first metal composition includes aluminum-metal composites.

7. The apparatus of claim 1, wherein the second metal composition is a stainless steel composition.

8. An apparatus comprising:

a first disk drive component comprising a first material with a first CTE (“

coefficient of thermal expansion”

), the first material comprising aluminum and comprising silicon, carbon, carbide, boride, aluminum-molybdenum, aluminum-beryllium, aluminum-germanium, aluminum-molybdenum-titanium, aluminum-germanium-silicon, aluminum-silicon-bronze, aluminum-silicon-magnesium-copper-nickel, or nitride and boron; and

a second disk drive component comprising a second material with a second CTE, wherein

the second disk drive component is connected to the first disk drive component and includes a different composition than the first disk drive component, and

the first disk drive component and the second disk drive component produce an adjacent track erasure of less than 10% on a recording medium between 0°

C. and 60°

C.

9. The apparatus of claim 8, wherein the first disk drive component is a base or an arm.

10. The apparatus of claim 8, wherein the second disk drive component is a cover or a suspension.

13. The apparatus of claim 8, wherein the second material comprises a stainless steel composition.

23. The apparatus of claim 8, wherein the first disk drive component is a base and the second disk drive component is a cover.

24. The apparatus of claim 23, wherein the second material comprises a stainless-steel composition.

25. The apparatus of claim 8, wherein the first disk drive component is a disk drive arm and the second disk drive component is a disk drive suspension.

26. The apparatus of claim 25, wherein the second material comprises a stainless-steel composition.

11-12. -12. (canceled)

14. An apparatus comprising:

a disk drive base comprising an aluminum composition with a first CTE (“

coefficient of thermal expansion”

);

a reader and a writer rotatable with respect to the disk drive base, wherein a separation between the reader and the writer affects an MR (“

magnetoresistive”

) offset;

a disk drive cover attached to the disk drive base and comprising a stainless steel composition with a second CTE that is different from the first CTE,

wherein, in response to temperature changes between 0°

C. and 60°

C., the aluminum composition and the stainless-steel composition expand and contract in equal or substantially equal proportion.

18. The apparatus of claim 14, wherein the aluminum composition comprises aluminum-ceramic composites.

19. The apparatus of claim 14, wherein the aluminum composition comprises aluminum-metal composites.

21. The apparatus of claim 14, wherein the disk drive base further comprises silicon, carbon, carbide, boride, aluminum-molybdenum, aluminum-beryllium, aluminum-germanium, aluminum-molybdenum-titanium, aluminum-germanium-silicon, aluminum-silicon-bronze, aluminum-silicon-magnesium-copper-nickel, or nitride and boron.

22. The apparatus of claim 14, wherein the first CTE and the second CTE limit a change of the MR offset to less than 10% between 0°

C. and 60°

C.

15-17. -17. (canceled)

20. (canceled)