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(12) United States Patent ao) Patent No.: us 6,645,308 B2
Wong et al. (45) Date of Patent: Nov. 11,2003
(54) POLISH CLEANING APPARATUS AND METHOD IN MANUFACTURE OF HGA
(75) Inventors: Mingbing Wong, Xianyou (CN);
Fuhong Yu, Tuen Mun (CN); Liang
Qian, Dongguan (CN); Feng Xie,
(73) Assignee: SAE Magnetics (H.K.) Ltd., Kwai
( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 156 days.
(21) Appl. No.: 09/810,833
(22) Filed: Mar. 16, 2001
(65) Prior Publication Data
US 2001/0030171 Al Oct. 18, 2001 (30) Foreign Application Priority Data
Apr. 13, 2000 (WO) CN00/00089
(51) Int. C I. B08B 7/04
(52) U.S. CI 134/6; 134/7; 134/26
134/29; 134/34; 134/42; 451/28; 451/66 15/93.1; 360/128; 360/235.1; 216/52; 216/53
(58) Field of Search 134/6, 7, 26, 34,
134/42, 29; 451/28, 66; 360/128, 235.1;
15/97.1; 216/52, 53, 83
(56) References Cited
U.S. PATENT DOCUMENTS
POLISH CLEANING APPARATUS AND
METHOD IN MANUFACTURE OF HGA
FIELD OF THE INVENTION 5
The present invention relates generally to a cleaning and polishing apparatus and method used in the disk drive industry. More specifically, the present invention relates to a cleaning and polishing apparatus and method used in the manufacture of a head gimbal assembly.
BACKGROUND OF THE INVENTION
Thin film heads are used for reading or writing data onto a recording layer of a data storage disk. Typically, the head 15 "flies " above the surface of the disk at a very low "altitude". The height of the air gap between the head and the disk is usually measured in fractions of a micron. The low height of the air gap causes an air bearing to be formed.
For a disk that stores data using magnetic effects, the head 20 usually includes a radio frequency coil for transmitting and receiving a magnetic field to write and read in the recording layer. For disks that store data using optical effects, the head may include an objective lens to focus a light beam at the recording layer. 25
Along with the evolution of the disk industry, the surface cleanliness of read-write heads has become one of the most critical concerns. With low-flying heads, dust in the environment is a serious problem. Dust particles can cause catastrophic "head crashes "destroying the head and disk. 30 Also, significant amounts of dust can accumulate on the head to interfere with the magnetic or optical effects. Contaminants may cause a disk driver to malfunction or even fail to spin up.
Classical wash, rinse and dry technology using an aqueous chemical substance and ultrasonic agitation can not provide adequate cleaning efficiency for a head's air bearing surface. More effective contamination removal methods to ensure that components and drives always remain as clean as 4Q possible are needed.
U.S. Pat. No. 5,467,238 issued to Neville K. Lee et al on Nov. 14, 1995, disclosed a cleaning apparatus for cleaning read/write heads used for accessing data stored on a recording disk of a disk drive. The cleaning apparatus had a 45 mounting base positioned adjacent to the disk. The base includes a ratchet mechanism for rotating a cleaning pad mounted thereon. The rotary or linear actuator arm used to position the read/write head activates the ratchet mechanism. The ratchet mechanism rotates the cleaning pad while 50 the actuator unloads the read/write head from the disk. A loading ramp is used to vertically position the read/write head relative to a cleaning surface of the cleaning pad. This conventional cleaning apparatus is more complicated in structure, lower in efficiency, and is used only after assembly 55 of a disk drive, making it unsuitable for use in the mass production of the heads.
SUMMARY OF THE INVENTION
A new kind of cleaning and polishing apparatus and 60 method for cleaning the heads of a head gimbal assembly to eliminate contamination of the heads by dusts or particulates is disclosed. In accordance with one aspect of the present invention, a cleaning and polishing apparatus for cleaning a head of a head gimbal assembly (HGA) may have a frame, 65 a plurality of carriers for locating and holding a plurality of HGAs, a plurality of polish fingers under the carriers and
fixed on a loading base, a cloth attached to said polish fingers, and a plurality of press-pins on each of the carriers. The HGAs may have a face and a slider with an air-bearing surface (ABS) to be polished and directed downwards. The cloth may act as a polish medium to provide a plurality of polish surfaces on which the HGAs are polished and cleaned. The press pins press on a HGA's flexure to provide proper friction between the slider ABS and the polish surface.
According to another embodiment, a pneumatic cylinder unit is combined with the carriers. The pneumatic cylinder unit, controlled by a programmable controller, may move the carriers, as well as the plurality of HGAs. The pneumatic cylinder unit may move back and forth in X and Y directions according to a customized program. The solution may be sufficiently agitated by the motion of a cylinder unit to promote dissolution action. Also, a polish tank containing a cleaning solution, may be provided on the top of the frame. The cleaning solution is recirculated through a pump and a filter canister with an effective filter cartridge. The filter canister may filter off the insoluble, suspended contaminants and particles in the solution so that the slider ABS will not be re-contaminated. A thermostatically controlled strip heater may heat the solution to a desired working temperature. The contaminants maybe scrubbed off into the solution through solubilization, emulsification, chemical action by a detergent, etc. The temperature, kind, and concentration of the chemical substance of said solution may be selected to achieve maximum cleaning effectiveness. The apparatus and method of the invention is suitable for the removal of dusts, oils, fingerprints, and other organic and inorganic contaminants in the form of both particulate and thin-film.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects and advantages of the present invention will be described by way of preferred embodiments and with reference to the drawings, in which
FIG. 1 is a top view of the polish cleaning apparatus of the present invention;
FIG. 2 is a perspective view of an HGA carrier positioned on polish fingers in the polish cleaning apparatus of the present invention; and
FIG. 3 is a diagram of water circulation of the polish cleaning apparatus.
The head gimbal assembly (HGA) is a precision component in a disk drive. The conventional ultrasonic cleaning can cause mechanical damage under high ultrasonic power, which limits its application, and can not provide an adequate cleaning effect. However, the new polish cleaning technology can effectively clean the head and does not cause side effects for HGA performance. Basically, the polish cleaning can remove all kinds of contaminants such as dust, particles, film, etc. Its removal efficiency can achieve up to 95% for all kinds of contaminants whether it's organic or inorganic, while the classical ultrasonic cleaning does only about 60% for small particles and is not efficient for other kinds of contaminants.
As shown in FIGS. 1-3, one embodiment of a polishing and cleaning apparatus of the present invention may have polish fingers, HGA carriers, a cylinder motion unit and an immersion polish tank.
In one embodiment of the present invention, the polishing and cleaning method may be a contact-cleaning process