Symmetrical microactuator structure for use in mass data storage devices, or the like

• US 6,473,274 B1
• Filed: 06/28/2000
• Issued: 10/29/2002
• Est. Priority Date: 06/28/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Wachtler, Kurt P., Maimone, Peter J., Heaton, Mark W., Lin, Tsen-Hwang
• Primary Examiner(s): Heinz, A. J.
• Application Number:
  US09/607,413
• Time in Patent Office: 853 Days
• Field of Search: 360/294--29, 360/264.5
• US Class Current: 360/294.5
• CPC Class Codes: G11B 5/5552 using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means

Abstract

A microactuator includes a base, first microactuator elements carried by the base, a platform attached to the base, second microactuator elements carried by the platform, and the first microactuator elements being located substantially symmetrically on either side of a plane along a centerline of the base

Claims

1. A microactuator, comprising:

a base;

first microactuator elements carried by said base;

a platform hingedly attached to said base;

second microactuator elements carried by said platform;

said first microactuator elements located substantially symmetrically on either side of a plans along a centerline of said base.

2. The microactuator of claim 1 wherein said first microactuator elements comprise coil elements on either side of said base.

3. The microactuator of claim 2 wherein said coils are copper.

4. The microactuator of claim 2 wherein said first microactuator elements comprise magnetic flux carrying elements adjacent said coils and disposed on either side of said base.

5. The microactuator of claim 4 wherein said magnetic flux carrying elements are nickel-iron.

6. A microactuator, comprising:

a base;

first microactuator elements carried by said base;

a platform hingedly attached to said base;

second microactuator elements carried by said platform;

said first microactuator elements located substantially symmetrically on either side of a plane along a centerline of said base,

wherein said first microactuator elements comprise coil elements on either side of said base,

wherein said first microactuator elements comprise magnetic flux carrying elements adjacent said coils and disposed on either side of said base,

wherein said magnetic flux carrying elements form an “

I”

shaped member.

7. A microactuator, comprising:

a base;

first microactuator elements carried by said base;

a platform hingedly attached to said base;

second microactuator elements carried by said platform;

said first microactuator elements located substantially symmetrically on either side of a plane along a centerline of said base,

wherein said first microactuator elements comprise coil elements on either side of said base,

wherein said first microactuator elements comprise magnetic flux carrying elements adjacent said coils and disposed on either side of said base,

wherein said magnetic flux carrying elements further comprise an end piece and a corresponding flux receiving piece, separated by a gap to transfer magnetic flux generated by said coils across said gap to move said platform relative to said base.

8. A microactuator for use in a mass data storage device of the type having an arm that carries a transducer that is selectively positioned adjacent a spinning rotating disk, comprising:

a first portion carried by said arm;

first microactuator elements mounted in said first portion, including a substrate base;

a second portion tethered in an aperture in said first portion to form a platform therewithin;

second microactuator elements mounted in said second portion, wherein movement of said platform moves a position of said transducer;

said first microactuator elements located substantially symmetrically on either side of a plane along a centerline of said first portion.

9. The microactuator of claim 8 wherein said first microactuator elements comprise coils on either side of said substrate base.

10. The microactuator of claim 9 wherein said coils are copper.

11. The microactuator of claim 9 wherein said first microactuator elements comprise magnetic flux carrying elements adjacent said coils and disposed on either side of said substrate base.

12. The microactuator of claim 11 wherein said magnetic flux carrying elements are nickel-iron.

13. The microactuator of claim 11 wherein said magnetic flux carrying elements form an “

I”

shaped member.

14. The microactuator of claim 11 wherein said magnetic flux carrying elements further comprise an end piece and a corresponding flux receiving piece, separated by a gap to transfer magnetic flux generated by said coils across said gap to move said second portion to position said transducer.

15. A microactuator for use in a mass data storage device, comprising:

a substantially planar arm having a hole therewithin;

a data transducer carried on said arm;

a torsion member located within the hole of said arm;

a plurality of tethers suspending said torsion member within said hole in said arm, wherein rotational movement of said torsion member causes lateral movement of a portion of said arm to laterally move said data transducer;

a ferrous material having a first portion on said arm and a second portion on said torsion member;

a plurality of conductors arranged to induce a magnetic field into said first and second portions of said ferrous material to produce said rotational movement of said torsion member;

a dielectric separating said plurality of conductors from said ferrous material;

said ferrous material, plurality of conductors, and dielectric being substantially symmetrically arranged on a top and a bottom of a plane within said arm.

16. The microactuator of claim 15 wherein said substantially symmetrical arrangement of said ferrous material, plurality of conductors, and dielectric results in substantially equal masses, modulus, and volume of said ferrous material, plurality of conductors, and dielectric on each side of said plane.

17. The microactuator of claim 15 wherein said arm at least partially comprises silicon.

18. The microactuator of claim 15 wherein said ferrous material has a substantially “

I”

shaped cross-section.

19. The microactuator of claim 15 wherein said arm at least partially comprises a composite dielectric material.

20. The microactuator of claim 15 wherein said coils are embedded within said arm.

21. The microactuator of claim 15 wherein said coils are located in part above and in part below top and bottom portions of said arm.

22. The microactuator of claim 15 wherein said ferrous material is nickel-iron material.

23. The microactuator of claim 15 wherein said ferrous material has an “

I”

shaped cross-section centered about said plane.

24. A microactuator for providing fine position adjustment to a transducer assembly carried on a positioning arm, said microactuator, comprising:

a first portion constructed on said arm;

a platform located within a hole in the arm, said platform being tethered to said first portion and being moveable to cause lateral movement of said arm and transducer, and spaced from said first portion by a gap;

an “

I”

shaped nickel-iron member extending through a central silicon substrate;

a first nickel-iron member attached to said “

I”

shaped nickel-iron member, on said arm adjacent said platform;

a corresponding nickel-iron member on said platform separated from said first nickel-iron member by said gap;

a plurality of copper coils surrounding a center portion of said “

I”

shaped nickel-iron member to generate a magnetic flux in said nickel-iron members when said copper coils are energized to move said transducer;

said “

I”

shaped nickel-iron member and said plurality of copper coils being arranged substantially symmetrically about a plane extending centrally through said central silicon substrate with respect to a top bottom thereof.