Method for manufacturing a hard disk read/write unit, with micrometric actuation

• US 6,446,326 B1
• Filed: 05/05/1999
• Issued: 09/10/2002
• Est. Priority Date: 05/05/1998
• Status: Active Grant

• Current Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Mastromatteo, Ubaldo, Murari, Bruno, Zerbini, Sarah, Vigna, Benedetto
• Primary Examiner(s): Vo, Peter
• Assistant Examiner(s): KIM, PAUL D
• Application Number:
  US09/305,862
• Time in Patent Office: 1,224 Days
• Field of Search: 296/030.4, 296/030.7, 296/031.8, 296/031.9, 360/97.01, 360/98.01, 360/98.08, 360/99.12
• US Class Current: 29/603.04
• CPC Class Codes: G11B 5/5552 using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means
• CPC Class Codes: G11B 5/58 with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following spacing means incorporated in the head structure G11B5/187, G11B5/255, G11B5/3106
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: Y10T 29/49027 Mounting preformed head/core onto other structure
• CPC Class Codes: Y10T 29/49032 Fabricating head structure or component thereof
• CPC Class Codes: Y10T 29/49052 by etching
• CPC Class Codes: Y10T 29/49053 Multitrack heads having integral holding means

Abstract

The method comprises the steps of: forming an integrated device including a microactuator in a semiconductor material wafer; forming an immobilization structure of organic material on the wafer; simultaneously forming a securing flange integral with the microactuator and electrical connections for connecting the integrated device to a read/write head; bonding a transducer supporting the read/write head to the securing flange; connecting the electrical connections to the read/write head; cutting the wafer into dices; bonding the microactuator to a suspension; and removing the immobilization structure.

Claims

1. A method for manufacturing a hard disk read/write unit having micrometric actuation, comprising:

forming an integrated device including a microactuator securable to a suspension device the microactuator comprises an external stator connected to a plate of gimbal and an internal rotor connected to the stator and bonded to a hard disk read/write transducer;

forming an immobilization structure on said microactuator after said microactuator is formed the immobilization structure being releasably coupled to the rotor; and

securing said read/write transducer to said microactuator after forming the immobilization structure.

2. A method for manufacturing a hard disk read/write unit having micrometric actuation, comprising:

forming an integrated device including a microactuator securable to a suspension device the microactuator comprises an external stator connected to a plate of gimbal and an internal rotor connected to the stator and bonded to a hard disk read/write transducer;

forming an immobilization structure on said microactuator;

securing a read/write transducer to said microactuator after forming the immobilization structure; and

removing said immobilization structure after said securing said transducer to said microactuator.

3. A method for manufacturing a hard disk read/write unit having micrometric actuation, comprising:

forming an integrated device including a microactuator securable to a suspension device the microactuator comprises an external stator connected to a plate of gimbal and an internal rotor connected to the stator and bonded to a hard disk read/write tranducer;

forming an immobilization structure on said microactuator; and

securing a read/write transducer to said microactuator after forming the immobilization structure;

wherein said securing comprises;

forming a securing flange rigid on said microactuator, said securing flange being immobilized by said immobilization structure; and

bonding said transducer to said securing flange.

4. The method according to claim 3 wherein said securing flange is made of metal.

5. The method according to claim 3, further comprising forming electrical connections between said transducer and said integrated device, simultaneously with said forming said securing flange.

6. The method according to claim 5, wherein, before said step of securing, the step of forming the immobilization structure includes:

forming a sacrificial layer of organic material extending above said integrated device and inside trenches in said microactuator;

selectively removing regions of said sacrificial layer above areas of said microactuator anchorable to said transducer and above pads of said integrated device electrically connectable to said transducer; and

forming a mold mask having apertures above the selectively removed regions of said sacrificial layer;

wherein the step of forming said securing flange includes forming said securing flange and said electrical connections in said apertures of said mold mask.

7. The method according to claim 5, further comprising ball bonding said electrical connections to pads of said transducer after said securing the transducer.

8. The method according to claim 6, further comprising before said forming said mold mask:

depositing a metal anchorage layer in the selectively removed regions of said sacrificial layer; and

selectively removing said metal anchorage layer to form anchorage regions, only in said selectively removed regions of said sacrificial layer.

9. The method according to claim 8 wherein said forming said securing flange and said electrical connections comprises:

electrolessly growing metal material portions on said anchorage regions;

depositing a metal support layer; and

defining said metal support layer to form said securing flange and said electrical connections.

10. The method according to claim 8 wherein said anchorage regions, said electrolessly grown metal material portions, said securing flange and said electrical connections are made of a metal selected from copper or nickel.

11. The method according to claim 6 wherein said sacrificial layer is made of a material selected from resin or pix.

12. The method according to claim 6 wherein said mold mask is made of a material selected from resist or resin.

13. A method for manufacturing a hard disk read/write unit having micrometric actuation, comprising:

forming an integrated device including a microactuator securable to a suspension device the microactuator comprises an external stator connected to a plate of gimbal and an internal rotor connected to the stator and bonded to a hard disk read/write transducer;

forming an immobilization structure for said microactuator;

securing a read/write transducer to said microactuator after forming the immobilization structure; and

, after said securing the transducer;

securing said read/write unit to said suspension device; and

removing said immobilization structure from said microactuator.

14. A method for manufacturing a hard disk read/write unit having micrometric actuation, comprising:

forming an integrated microactuator comprises an external stator and an internal rotor including a suspended movable mass the movable mass being separated from the stator by a trench;

forming an immobilization structure that extends inside the trench to restrict movement of the movable mass with respect to the stator;

forming an anchorage region on the movable mass; and

affixing a read/write transducer to the anchorage region while the immobilization structure immobilizes the movable mass with respect to the stator.

15. The method of claim 14 wherein forming the microactuator includes removing a sacrificial layer positioned below the movable mass, thereby suspending the movable mass, and wherein the immobilization structure is formed on the microactuator after the movable mass is suspended.

16. The method of claim 14 wherein the immobilization structure contacts and secures the anchorage region while the read/write transducer is affixed to the anchorage region.

17. The method of claim 14 wherein the affixing step includes forming a support flange affixed to the anchorage region and affixing the read/write transducer to the support flange.