Dynamic magnetic information storage or retrieval – Fluid bearing head support – Disk record
Reexamination Certificate
1995-10-30
2001-05-15
Cao, Allen T. (Department: 2652)
Dynamic magnetic information storage or retrieval
Fluid bearing head support
Disk record
Reexamination Certificate
active
06233117
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the field of disc drive data storage devices. More specifically, the invention relates to providing an electrical path between a head assembly and a gimbal assembly in a magnetic disc drive.
Disc drive data storage devices of the “Winchester” type are well known in the industry. Such devices utilize rigid discs coated with a magnetizable medium for storage of digital information in a plurality of circular concentric tracks. This information is written to and read from the discs using a transducing head carried on a head assembly mounted on an actuator mechanism which moves the head from track to track across the surface of the disc under control of electronic circuitry. The discs are mounted for rotation on a spindle motor which causes the discs to spin and the surface of the discs to pass under the head.
In such a disc drive, the head assembly “flies” over the surface of the disc as the disc rotates at high speed. The head assembly includes a transducing head which is carried on a slider which has aerodynamic properties allowing the head assembly to fly. The head assembly is mounted on a gimbal assembly which is carried on a load beam armature coupled to the actuator mechanism. The gimbal assembly allows the head assembly to tilt, thereby achieving aerodynamic equilibrium. The armature is spring loaded and counteracts a lifting force from the slider as the head assembly flies across the disc surface. The spring loaded armature and the aerodynamic lifting force reach an equilibrium based upon the aerodynamic properties of the slider and the speed of rotation of the disc.
It is important to provide an electrical ground to the head assembly through the armature to the chassis of the disc drive. This helps reduce the buildup of static electricity on the head assembly which can arc to the storage disc. Further, the electrical grounding of the head assembly helps reduce noise during readback of magnetically encoded information.
Typical prior art techniques of achieving an electrical connection between the head assembly and the gimbal assembly have included the use of a conductive adhesive. However, the conductive adhesive suffers from a number of drawbacks including increased labor and material costs as well as relatively high resistivity.
In the prior art, adhering the head assembly to the gimbal assembly required a number of manual steps. First, a non-conducting adhesive was applied to the gimbal assembly. This adhesive was typically non-conducting so as not to electrically short electrical contact pads carried on the head assembly. After the head assembly was bonded to the gimbal assembly, a second electrically conductive adhesive was manually applied. The second adhesive was applied around the edge of the interface between the head assembly and the gimbal assembly. This technique does not lend itself to automated assembly lines.
In typical prior art disc drives, the average resistivity of head gimbal assemblies, as measured between the head assembly and the gimbal assembly in which the head assembly is attached to the gimbal assembly through a conductive adhesive, was approximately 400 &OHgr; with some ranging above 1000 &OHgr;.
SUMMARY OF THE INVENTION
The present invention provides a conductive path between a head assembly and a gimbal assembly in a magnetic disc drive. In the present invention, a magnetic disc drive includes a rotating magnetic storage disc rotatably mounted to a drive chassis which provides an electrical ground. A head assembly is used for reading and writing information on the disc surface and includes a slider and a transducing head which are adapted to fly over the disc surface as the disc rotates. An armature extends across the disc surface and includes an end adapted for carrying the head assembly across adjacent tracks on the surface of the disc. A gimbal assembly is carried on the end of the armature and allows movement of the head assembly relative to the plane of the surface of the storage disc. The head assembly is attached to the gimbal assembly. An electrically conductive metal path extends between the head assembly and the gimbal assembly, thereby electrically coupling the head assembly to electrical ground. In one embodiment, the electrically conductive metal path extends through an adhesive.
In a preferred embodiment, the conductive metal path is formed of gold. Typically, the resistance of the conductive metal path between the head assembly and the gimbal is less than about 460 &OHgr;. In one embodiment, a plurality of electrically conductive metal paths extend between the head assembly and the gimbal assembly.
The method of the present invention includes providing a mask over a surface of the head assembly. An electrically conductive layer is deposited on the surface of the head assembly through the mask. In one embodiment, the same mask is used to deposit the electrically conductive path as well as bonding pads which couple the transducing head.
REFERENCES:
patent: 4317149 (1982-02-01), Elser et al.
patent: 4761699 (1988-08-01), Aimslie et al.
patent: 4800454 (1989-01-01), Schwarz et al.
patent: 4841395 (1989-06-01), Craft
patent: 4972286 (1990-11-01), Jurisch et al.
patent: 5001583 (1991-03-01), Matsuzaki
patent: 5001591 (1991-03-01), Nakashima
patent: 5048175 (1991-09-01), Jurisch et al.
patent: 5142425 (1992-08-01), Gailbreath, Jr. et al.
patent: 5296983 (1994-03-01), Blanc et al.
patent: 5305167 (1994-04-01), Nagase et al.
patent: 5343344 (1994-08-01), Nagase
patent: 5384432 (1995-01-01), Noro et al.
patent: 5414576 (1995-05-01), Ueki et al.
patent: 5422764 (1995-06-01), McIlvanie
patent: 54-102111 (1979-08-01), None
patent: 93014495 (1993-07-01), None
IBM Technical Disclosure Bulletin (vol. 24, No. 10, Mar. 1982), p. 4915.*
IBM Technical Disclosure Bulletin (vol. 24, No. 10, Mar. 1982, p. 4915).
Rancour Michael L.
Tervalon, III Albert L.
Troutman Mark E.
Cao Allen T.
Seagate Technology LLC
Westman Champlin & Kelly P.A.
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