Dynamic magnetic information storage or retrieval – Head mounting – For adjusting head position
Reexamination Certificate
2000-03-30
2001-03-06
Evans, Jefferson (Department: 2754)
Dynamic magnetic information storage or retrieval
Head mounting
For adjusting head position
Reexamination Certificate
active
06198606
ABSTRACT:
TECHNICAL FIELD
The present invention relates to disc drive micro-actuators. Even more particularly, the present invention relates to injection-molded disc drive micro-actuators having metal inserts and etched substrates.
BACKGROUND OF THE INVENTION
With the increasing density of information stored on magnetic discs, there is a need for more precise head positioning. Related art disc drive actuation systems using electrostatic micro-actuators do not provide sufficient actuation force to this end. In U.S. patent application Ser. No. 09/315,006, filed May 16, 1999, for “Magnetic Micro-Actuator” by P. Crane, W. Bonin, and B. Zhang, herein incorporated by reference, a magnetic micro-actuator is disclosed which is used in a dual-stage actuation assembly. A voice coil motor provides gross movement in a first stage and a magnetic micro-actuator provides fine movement in a second stage. The micro-actuator assembly uses a high strength wafer substrate material such as molybdenum or cold-rolled titanium. Alternatively, the micro-actuator assembly may also utilize a conventional wafer substrate material such as silicon. Such substrate materials would need to be etched. Problems associated with magnetic micro-actuator fabrication arise from high machining cost, inherent fragility of a silicon substrate as demonstrated during micro-electro-mechanical system (MEMS) fabrication and upon exposure to shock, platting of the “stand-offs,” and de-lamination of the magnet assembly from the silicon substrate. Thus, the cost-effective manufacturing, via injection-molding, of a disc drive actuation system using a durable head level magnetic micro-actuator, having flexible beam inserts etched from an inexpensive substrate, is desirable.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide a cost-effective method of fabricating a head level magnetic micro-actuator assembly, having flexible beam inserts etched from an inexpensive substrate, utilized in a disc drive actuation system for reading from and writing to a disc and a system thereby formed. Accordingly, this objective is accomplished by fabrication of a magnetic micro-actuator assembly by a process comprising the steps of: (a) forming a mold with a first cavity for a micro-actuator body and a second cavity for a slider body; (b) placing a plurality of magnets in a magnet keeper; (c) placing the magnet keeper in the second cavity of the mold; (d) etching a flexible beam insert from a flexible material such as sheet stainless steel; (e) placing the flexible beam insert into the mold; (f) filling the mold with a fluid; (g) solidifying the fluid to form the micro-actuator body and the slider body; (h) removing the micro-actuator body and slider body from the mold; and (i) inserting a slider into the slider body.
Subsequently, the magnetic micro-actuator assembly is installed into a disc drive assembly, wherein a voice coil is mounted to an end of an actuator arm, wherein the actuator arm is mounted on a spindle for rotating about an axis, wherein a head suspension is connected to an opposite end of the actuator arm at a head mounting block, wherein a flexure is mounted at one end of the head suspension away from the actuator arm, wherein the flexure carries the magnetic micro-actuator assembly for providing the requisite resolution and frequency response for precisely positioning a transducing head over a selected track of a disc, and thereby producing a disc drive actuation system having a magnetic micro-actuator using flexible beam inserts.
In addition, substrate fragility is no longer an issue as the present invention uses a flexible beam insert in contrast to related art apparati which use brittle silicon inserts. The fabrication process of the present invention involves a single injection-molding step, a tremendous cost and fabrication advantage over the related art process involving several MEMS steps. Further, a plurality of stand-offs for receiving a ferromagnetic keeper and a gimbal assembly may be added during the injection-molding step without adding cost.
The resultant micro-actuation system is an injection-molded micro-actuator body and an injection-molded slider body, with flexible beams metal inserts extending from the micro-actuator body to the slider body. The slider body supports a slider with a transducing head. The micro-actuator body acts as a stator of a motor and the slider body acts as a rotor of a motor. The flexible beams allow movement between the micro-actuator body and the slider body. The movement of the slider body allows for a fine movement control of the transducing head over a disc seated in a disc drive. Thus, a cost-effective method of fabricating a disc drive actuation system having a magnetic micro-actuator using flexible beam inserts and a disc drive system thereby formed are provided by the present invention.
Other features of the present invention are disclosed or apparent in the section entitled: “DETAILED DESCRIPTION OF THE INVENTION.”
REFERENCES:
patent: 5165090 (1992-11-01), Takahashi
patent: 5621590 (1997-04-01), Pace
patent: 5781380 (1998-07-01), Berding
patent: 5828521 (1998-10-01), Hasegawa
patent: 5894382 (1999-04-01), Hyde
patent: 5936805 (1999-08-01), Imaino
patent: 5959808 (1999-09-01), Fan et al.
patent: 5995334 (1999-11-01), Fan et al.
patent: 6067215 (2000-05-01), Zhang
patent: 6078471 (2000-06-01), Fiske
patent: 6078473 (2000-06-01), Crane et al.
patent: 6078476 (2000-06-01), Magee et al.
patent: 6097575 (2000-08-01), Trang et al.
Bonin Wayne Allen
Boutaghou Zine-Eddine
Crane Peter
Evans Jefferson
LaRiviere Grubman & Payne, LLP
Seagate Technology LLC
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