JP2009157984A - Manufacturing method of magnetic head - Google Patents

Abstract

【Task】
Provided is a magnetic head manufacturing method capable of suppressing interference between a head slider surface of a magnetic head and a magnetic disk surface and adhesion of wear powder that deteriorates flying characteristics.
In the method of manufacturing a magnetic head, charging is performed by irradiating a selected region of the head slider surface of the magnetic head with an electron beam in a reduced-pressure atmosphere, and supplying a raw material gas for the lubricating layer in the reduced-pressure atmosphere. A lubricant layer is formed by adsorbing to the generated region, and the lubricant layer adsorbed on the head slider surface is heated, or the lubricant layer adsorbed on the head slider surface is irradiated with high energy rays to fix the lubricant layer. .
[Selection] Figure 4

Description

  The present invention relates to a method for manufacturing a magnetic head, and more particularly to a method for manufacturing a magnetic head having a low flying height.

  In a magnetic storage device having a magnetic disk, the head slider surface of the magnetic head floats while maintaining a certain flying distance on the magnetic disk, and information is recorded on the magnetic disk or information stored on the magnetic disk is reproduced. .

  In recent years, the distance between the magnetic head and the magnetic disk, that is, the so-called flying height has been reduced with the improvement of the recording density of the magnetic disk. To record and reproduce information on a magnetic disk at high density, a magnetic head is placed close to the magnetic disk, a recording magnetic field is applied to a minute range, and a magnetic field leaking from the magnetic disk to a minute space is detected. Is necessary. With the increase in recording density of magnetic storage devices, the flying height is reduced to about a dozen nm.

  When recording and reproduction were not performed, the rotation of the magnetic disk was stopped, and the magnetic head was left in contact with the surface of the magnetic disk. When an impact is applied from the outside in this state, the magnetic head may hit the surface of the magnetic disk to form a dent or damage the recording layer. In addition, the magnetic head may be attracted to the surface of the magnetic disk and may not float again.

  A magnetic disk device has been proposed in which a lubricating layer is formed on the medium facing surface of the head slider of the magnetic head to prevent the head slider and the magnetic disk from being attracted (for example, Japanese Patent Laid-Open No. 05-325161).

  When the magnetic disk stops rotating and the head slider comes into contact with the magnetic disk, the air bearing surface of the head slider and the magnetic disk surface are prevented from contacting directly, and the medium facing surface of the head slider is attracted to the magnetic disk surface. In order to prevent this, it has been proposed to form a pad for preventing adsorption on the medium facing surface of the rail (for example, Japanese Patent Application Laid-Open No. 09-293223).

  It has been proposed to irradiate the lubricating layer with high energy beams such as ultraviolet rays, X-rays, electron beams, focused ion beams, etc., to form chemical bonds with the underlying surface, and to selectively or non-selectively fix them. (Japanese Patent Laid-Open No. 2006-286104).

  Also, a load / unload method is adopted in which a magnetic disk device is provided with a ramp portion for retracting the magnetic head, a load bar is connected to the tip of the magnetic head, and the magnetic head is loaded onto the ramp portion when rotation of the magnetic disk is stopped. It became so.

  In general, the recording surface of the magnetic disk is configured such that the recording layer is covered with a protective layer and the surface is covered with a lubricating layer. In a magnetic disk apparatus in which the magnetic head is flying above the rotating magnetic disk with a slight flying distance, it is inevitable that abrasion powder is generated from the magnetic disk surface. In the system in which the magnetic head is retracted on the ramp portion, it is difficult to avoid generation of wear powder even when the load bar of the magnetic head and the ramp portion slide. If the wear powder adheres to the head slider surface, the flying characteristics of the magnetic head are likely to deteriorate.

JP 05-325161 A JP 09-293223 A JP 2006-286104 A

  Even if the load / unload method is adopted in the magnetic disk device, it is difficult to deny the possibility that the head slider surface of the magnetic head will collide with or be attracted to the magnetic disk surface, and the floating characteristics will cause wear powder to adhere. There is a possibility of deterioration.

  In order to provide a stable magnetic head with excellent characteristics, it is desired to suppress interference between the head slider surface of the magnetic head and the magnetic disk surface and adhesion of wear powder that deteriorates flying characteristics.

  An object of the present invention is to provide an efficient manufacturing method of a magnetic head capable of suppressing interference between a head slider surface of a magnetic head and a magnetic disk surface and adhesion of wear powder that deteriorates flying characteristics.

According to one aspect of the present invention,
(A) a step of irradiating a selected region of a head slider surface of a magnetic head with an electron beam in a reduced-pressure atmosphere to cause charging;
(B) supplying a raw material gas for the lubricating layer in the reduced-pressure atmosphere and adsorbing it to the region where the charge is generated to form an adsorbed lubricant layer;
(C) heating the adsorbed lubricant layer or irradiating the adsorbed lubricant layer with high energy rays to fix the lubricant layer;
A method of manufacturing a magnetic head is provided.

  Provided is a manufacturing method for efficiently manufacturing a magnetic head that efficiently forms a selective lubricating layer, prevents adsorption, suppresses adhesion of wear, and is excellent in operational stability.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the magnetic storage device 10 includes a housing 11 and a magnetic disk 12, a magnetic head 13, an actuator unit 14, and the like stored in the housing 11. The magnetic disk 12 is fixed to the hub 15 and driven by a spindle motor. The base of the magnetic head 13 is fixed to the arm 16 and is attached to the actuator unit 14 via the arm 16. The magnetic head 13 is rotated in the radial direction of the magnetic disk 12 by the actuator unit 14. Further, on the back side of the housing 11, an electronic board for performing recording / reproducing control, magnetic head position control, spindle motor control, and the like is provided. A configuration may be provided in which a ramp portion for loading the magnetic head is provided.

  As the magnetic disk 12, an in-plane magnetic recording medium, a perpendicular magnetic recording medium, or a magneto-optical disk can be used. The magnetic disk 12 only needs to be recordable or reproducible by the magnetic head 13.

  The in-plane magnetic recording medium has a recording layer that is magnetized in a direction parallel to the substrate surface of the magnetic disk 12. The recording layer is not limited to a single ferromagnetic layer, and may be a laminate of a plurality of ferromagnetic layers. Further, the recording layer is a so-called laminated ferrimagnetic structure, that is, the lower magnetic layer and the upper magnetic layer are stacked with a nonmagnetic layer interposed therebetween, and the magnetization of the lower magnetic layer and the magnetization of the upper magnetic layer when no recording magnetic field is applied. And may be arranged antiparallel to each other. As the underlayer of the recording layer, a Cr film or a Cr alloy film (including W, Mo, V, B, etc. as additive elements in Cr) is used so that the magnetization of the recording layer is oriented in the in-plane direction.

  The perpendicular recording medium has a perpendicular magnetization film having a perpendicular magnetization on the substrate surface of the magnetic disk 12, and a soft magnetic backing layer on the substrate side.

  The recording layer is made of any material selected from the group consisting of Ni, Fe, Co, Ni alloys, Fe alloys, CoCr alloys including CoCrTa, CoCrPt, and CoCrPt-M for both in-plane and perpendicular magnetic recording media. Composed. Here, M is selected from B, Mo, Nb, Ta, W, Cu, and alloys thereof. The film thickness of the recording layer is set in the range of 3 nm to 30 nm.

  The magnetic head 13 is provided with a head slider 18 at its tip. Hereinafter, the magnetic head 13 and the head slider 18 will be described in detail.

  FIG. 2A is a plan view of the configuration of the magnetic head as viewed from the medium facing surface side, and FIG. 2B is a schematic diagram showing how the head slider of the magnetic head floats on the magnetic disk.

  As shown in FIGS. 2A and 2B, the magnetic head 13 includes a suspension 21, a head slider 18 fixed to the tip, and an element portion 22 (recording element 23a and reproducing element) formed on the head slider 18 for performing recording and reproduction. Element 23b) and the like.

  The suspension 21 includes a suspension body 21a made of a plate-like metal material, a base plate 24 provided at the base of the suspension body 21a, and a gimbal 25 for fixing the head slider 18 to the tip of the suspension body 21a. , A wiring pattern 26 for electrically connecting the element unit 22 including the recording element 23a and the reproducing element 23b and the head IC. The base plate 24 is fixed to the arm 16 of the actuator unit 14 shown in FIG. 1 by fitting or the like. The suspension body 21a is made of, for example, a metal material such as a stainless material having a plate thickness of 100 μm. The suspension body 21a functions as a leaf spring.

  As shown in FIG. 2B, the head slider 18 of the magnetic head 13 floats on the magnetic disk 12 that rotates and moves in the direction of the arrow ROT. The head slider 18 receives a pressure at which the medium facing surface 18a floats above the magnetic disk by the air flow AIR that flows in as the magnetic disk 12 moves. Further, the head slider 18 receives a pressing force (pressing force) from the suspension body 21 a to the magnetic disk 12 side via the gimbal 25. When the flying height is maintained at a desired level and stably, the magnetic head can obtain stable recording / reproducing characteristics.

  3A is a plan view of the magnetic head as viewed from the magnetic disk side, and FIGS. 7B and 7C are cross-sectional views taken along lines BB and CC.

The head slider 18 has a substantially rectangular parallelepiped shape, and the size is, for example, length 1.25 mm × width 1.00 mm × height 0.30 mm. The base material of the head slider 18 is made of a ceramic material such as Al ₂ O ₃ .TiC (altic). On the air outflow end 18TR side of the head slider 18, a protective film 28 such as an alumina film is formed with a thickness of several tens of μm. Note that a protective film such as diamond-like carbon may be formed on the ceramic material on the medium facing surface 18a.

  A front rail 30 is formed on the medium facing surface 18a on the air inflow end 18LD side, and a side rail 31 extending on the air outflow end 18TR side is formed on the side downstream side of the front rail 30. In addition, a rear center rail 32 and a rear side rail 33 are formed on the medium facing surface 18a on the side of the air outflow end 18TR, substantially at the center in the head slider width direction, and on the side thereof.

  The front rail 30 has an air bearing surface 30a extending in the width direction and a step surface 30b having a predetermined step lower than the air bearing surface 30a on the downstream side. Pads 30c protruding from the air bearing surface are formed at predetermined positions on the left and right sides of the air bearing surface. The pad 30c has a function of preventing the magnetic head from being attracted.

  A recess 34 is formed on the air outflow end 18TR side of the front rail 30. The depth of the recess is set to, for example, about 2 to 3 μm from the air bearing surface 30a.

  The rear center rail 32 is formed at the center of the head slider width direction on the air outflow end 18TR side. The rear center rail 32 has an air bearing surface 32a and a step surface 32b that is lower than the air bearing surface 32a by a predetermined step. The step surface 32b is formed on the air inflow end 18LD side of the air bearing surface 32a.

  The rear center rail 32 is formed with an element portion 22 on the air outflow end 18TR side of the air bearing surface 32a. In the element portion 22, a reproducing element and a recording element are stacked. As the reproducing element, for example, a spin valve magnetoresistive effect (MR) element, a Ferromagnetic Tunnel Junction MR (TMR) element, a ballistic MR element, or the like can be used. As the recording element, for example, a thin film induction type recording element (a ring type head or a single magnetic pole head for a perpendicular magnetic recording medium) can be used.

  The rear side rail 33 has an air bearing surface 33a and a step surface 33b that is lower than the air bearing surface 33a by a predetermined step.

  The air bearing surfaces 30a, 32a, and 33a are surfaces that are close to each other on the medium facing surface 18a, and their shapes and dimensions are set as appropriate according to flying design parameters such as flying height and flying posture (pitch angle, roll angle, etc.). .

  In this embodiment, pads 30c that protrude from the air bearing surface are formed at two locations on the left and right sides of the front rail 32. Pads may also be formed on the air bearing surface of the rear rail. Such a medium facing surface of the head slider made of Altic is processed by reactive ion etching or ion milling using a resist mask.

  In this embodiment, the lubricating layer 37 is formed on the surface of the front rail facing the pad 30c and on the air bearing surface of the rear rail. Rather than forming a lubricating layer over the entire medium facing surface of the head slider, forming a lubricating layer only in a selected region can prevent adsorption and adhesion of wear powder.

  FIG. 4 is a flowchart showing the manufacturing process of the magnetic head.

  In step S11, the suspension 21 is assembled as shown in FIG. 2A. This is a known process.

  In step S12, the head slider 18 is attached. This is a known process except for the configuration of the head slider.

  As shown in FIG. 5A, a plurality of suspensions each having a head slider 18 mounted thereon are placed side by side on a movable sample stage 61 of the electron beam irradiation apparatus. This is because a lubricating layer is formed on a plurality of magnetic heads simultaneously and selectively.

  FIG. 5B schematically shows the configuration of the electron beam irradiation apparatus. An electron gun 52 is disposed above the mirror tower 51, and an electron lens 53 and an electron scanning system 54 are disposed below the electron gun 52, and are controlled by a high voltage generation circuit 55, a lens excitation power circuit 56, and an electronic scanning circuit 58, respectively. A sample chamber is disposed below the mirror tower 51, and a movable sample stage 61 is disposed therein. The inside of the mirror tower 51 and the sample chamber 60 can be evacuated to a high vacuum by the evacuation system 62. The position of the electron beam on the sample is detected by the detector 58 and the monitor 59 and fed back to the electron beam scanning circuit 57. A desired position on the sample can be irradiated with an electron beam. A carrier gas of an inert gas such as Ar is supplied from the carrier gas source 63 to the bubbler 64, and the solution of the lubricant material is bubbled, so that the gasified lubricant material can be supplied into the sample chamber 60. The temperature of the bubbler 64 is controlled by a heater supplied with power from the heater control power supply 65. As shown in FIG. 5A, a movable sample stage 61 on which a plurality of magnetic heads are mounted is loaded in the sample chamber 60.

  The present inventors have found that when a charge is selectively generated on a sample surface in a vacuum and a lubricant gas is supplied thereto, the molecules of the lubricant gas are selectively adsorbed on the charged surface. If this adsorbed lubricant is fixed, a lubricating layer can be selectively formed at an arbitrary position on the sample surface.

  In step S13, the selected surface of the magnetic head placed on the movable sample stage 61 in the electron beam irradiation apparatus is irradiated with an electron beam to cause charging. For example, charging is generated on the medium facing surface of the pad 30c shown in FIGS. 3A to 3C and the air bearing surfaces 32a and 33a of the rear rail.

  In step S14, for example, a fluorinated polyether lubricant is bubbled using an inert gas as a carrier gas, and the lubricant is introduced into the sample chamber.

  In step S15, the lubricant is adsorbed on the region charged by the electron beam irradiation after a predetermined time. As described above, this is a phenomenon found by the present inventors.

  In step 16, a chemical adsorption promotion step for chemically adsorbing the adsorbed lubricant to the base surface is performed by heating or irradiation with a high energy beam. In the case of heating, the target surface is heated to a temperature of 80 ° C. to 200 ° C. by an oven or a rapid heating processor. In the case of irradiation with a high energy beam, for example, ultraviolet irradiation using a mercury lamp or an excimer vacuum ultraviolet lamp, for example, electron beam irradiation with an acceleration voltage of about 10 kV, infrared irradiation, or the like is performed. The lubricant is excited by heating or irradiation with a high energy beam, and promotes chemical adsorption to the base surface.

  In step S17, the physically adsorbed lubricant is removed as necessary. For example, the suspension is washed by immersing it in a solvent of a lubricant and naturally dried.

An example is shown below.
Example 1
An electron beam is irradiated to the air bearing surface on the rear center rail including the element portion of the head slider and the pad on the front rail with an acceleration voltage of 250 V to charge 5 μC / cm ² .

  As the lubricant, a perfluoropolyether having a straight chain as the main chain and a fluorinated polyether having both end groups as trifluoromethyl groups, Ar was flowed at 10 sccm as a carrier gas into a bubbler heated to 80 ° C. Fill for 30 seconds. A lubricating layer having a thickness of about 1.5 nm is formed on the medium facing surface of the pad.

A gas containing a lubricant is purged, and an electron beam of 10 μC / cm ² is irradiated with an acceleration voltage of 10 kV. A lubricating layer having a thickness of about 1.5 nm and a chemical adsorption rate of 100% is formed.
Example 2
An electron beam is irradiated to the air bearing surface on the rear center rail including the element portion of the head slider and the pad on the front rail with an acceleration voltage of 250 V to charge 5 μC / cm ² .

As a lubricant, a perfluoropolyether having a straight chain as a main chain and a fluorinated polyether having both end groups as CF ₂ CHOH, Ar was allowed to flow at 10 sccm as a carrier gas in a bubbler heated to 80 ° C., and 30 samples were passed through the sample chamber. Fill seconds. A lubricating layer having a thickness of about 1.3 nm is formed on the medium facing surface of the pad.

A gas containing a lubricant is purged, and an electron beam of 10 μC / cm ² is irradiated with an acceleration voltage of 10 kV. A lubricating layer having a thickness of about 1.3 nm and a chemical adsorption rate of 100% is formed.

  In addition to the fluorinated polyether, a fluorine-based hydrocarbon such as perfluorohydrocarbon may be used as the lubricant.

  The thickness of the lubricating layer is preferably 0.5 nm to 2.0 nm. If the thickness exceeds 2.0 nm, the distance between the head slider surface and the magnetic disk surface increases, and the reproduction output and S / N ratio tend to decrease. If the thickness is less than 0.5 nm, the lubricating layer is difficult to cover the underlying surface.

  When the ratio of the hydrocarbon hydrogen corresponding to the main chain of the lubricant molecule replaced with fluorine is called the fluorine content, the fluorine content of the lubricant molecule in the lubricant layer is preferably 80% or more, and 90% or more. It is more preferable that it is 95% or more. The average molecular weight of the lubricant is preferably in the range of 2000-20000.

  30% to 100% is preferable, and 70% to 100% is more preferable as the adhesion rate at which the lubricant molecules of the lubricating layer are chemically adsorbed to the underlying surface. If it is less than 30%, a head crash tends to occur when a running test is performed in which the magnetic head is levitated on the magnetic disk in a hot and humid environment. The smaller the number of physical adsorption layers, the better. Ideally, a lubricating layer is formed only by a chemical adsorption layer.

  As mentioned above, although this invention was demonstrated along the Example, this invention is not limited to these. For example, various techniques described in the column of the best mode for carrying out the invention of Japanese Patent Application Laid-Open No. 2006-286104 can be employed.

1 is a plan view schematically showing a configuration of a magnetic disk device. 2A and 2B are a plan view schematically showing the configuration of the magnetic head and a side view schematically showing how the magnetic head floats on the magnetic disk. 3A, 3B, and 3C are a plan view and a cross-sectional view schematically showing a magnetic head manufactured according to an embodiment of the present invention. 4 is a flowchart showing main steps of a magnetic head manufacturing method according to an embodiment of the present invention. 5A and 5B are a plan view and a cross-sectional view schematically showing the configuration of the magnetic head and the electron beam irradiation apparatus carried into the electron beam irradiation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic storage device 12 Magnetic disk 13 Magnetic head 14 Actuator unit 18 Head slider 18a, 50a Medium opposing surface 21 Suspension 21a Suspension main-body part 22 Element part

Claims (3)

(A) a step of irradiating a selected region of a head slider surface of a magnetic head with an electron beam in a reduced-pressure atmosphere to cause charging;
(B) supplying a raw material gas for the lubricating layer in the reduced-pressure atmosphere and adsorbing it to the region where the charge is generated to form an adsorbed lubricant layer;
(C) heating the adsorbed lubricant layer or irradiating the adsorbed lubricant layer with high energy rays to fix the lubricant layer;
A method of manufacturing a magnetic head including:   The method of manufacturing a magnetic head according to claim 1, wherein a head slider surface of the magnetic head includes a rail and a pad formed on the rail, and the step (a) selectively irradiates the pad with an electron beam. . The step (c) has a function of changing physical adsorption to chemical adsorption,
(D) cleaning the lubricating layer and removing the physical adsorption layer;
The method of manufacturing a magnetic head according to claim 1, further comprising:

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