JP2009009636A - Magnetic head slider - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that as the magnetic recording density is increased, the effect of dust increases on the reliability of the magnetic disk drive, especially the dust remarkably degrades the characteristics of the reproducing element on the magnetic head slider. <P>SOLUTION: The magnetic head slider 1 is composed of a slider 1a and a thin-film head 1b. The thin-film head 1b is composed of a thin film layer 4, a magnetic reproducing element 3, a magnetic recording element 2, and an insulation film made of alumina or the like formed between and on those elements. The thin film layer 4 is formed on the first insulation film 13 made of alumina, and is made of an NiFe alloy of the same material as the lower magnetic shield film 30 or a CoPt-based alloy of the same material as the magnetic domain control film 38, and has a hardness lower than the first insulation film 13. The end of the thin film layer 4 is exposed on the floating surface 9 and its width W2 in the track width direction is larger than the total width W1 of the MR film 34 width and the magnetic domain control film 38 width. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic head slider for realizing a high recording density of a magnetic disk device.

  The magnetic disk apparatus includes a rotating magnetic disk, a slider on which a magnetic head (recording / reproducing element) is mounted, and a support mechanism including a suspension that supports the slider, and the slider is positioned in the radial direction of the magnetic disk by the support mechanism. Then, the slider travels relatively on the magnetic disk and reads / writes magnetic information recorded on the magnetic disk by the recording / reproducing element. The slider floats as an air-lubricated bearing by the wedge film effect of air so that the magnetic disk and the slider are not in direct solid contact. In order to increase the recording density of a magnetic disk device and increase the capacity or size of the device, it is effective to increase the linear recording density by reducing the distance between the slider and the magnetic disk, that is, the slider flying height. is there.

  On the other hand, as conventionally known, dust existing inside the magnetic disk device is interposed between the slider and the magnetic disk, so that the flying height of the slider increases and the recording / reproducing characteristics of the recording / reproducing element deteriorate, resulting in an error. appear. Further, when the recording / reproducing element mounted on the slider is physically damaged due to the collision with dust, the recording / reproducing element may deteriorate and the magnetic disk device may fail. In addition to this, dust may enter between the slider and the magnetic disk and physically damage the surface of the magnetic disk, making it impossible to reproduce information on the magnetic disk.

  Conventionally, as a method for protecting the slider from dust, a land portion is provided on the inflow end side of the slider air bearing surface to prevent intrusion of dust (Patent Document 1), and a predetermined amount is provided on the inflow end side of the center pad of the slider air bearing surface. There is a method (Patent Document 2) in which a dust protection wall is provided at a distance to reduce intrusion of dust into the air bearing surface.

JP 09-326109 A Japanese Patent Laid-Open No. 10-144026

  The failure of the magnetic disk device due to dust increases as the flying height of the magnetic head slider decreases. In recent years, in particular, in order to improve the magnetic recording density, it is essential to reduce the magnetic spacing between the recording / reproducing element mounted on the slider and the magnetic disk. The thickness is reduced. Therefore, even if physical damage to the slider flying surface due to dust is extremely small, there is a high possibility that the reproducing element will be affected, the magnetic reproducing characteristics will deteriorate, and the magnetic disk device will be broken. . In particular, in a reproducing element using a tunnel current type magnetoresistive film (TMR film), when the tunnel barrier film is damaged, the insulation is lowered and the reproduction output is lowered. As described above, the influence of dust on the reliability of the magnetic disk device is increasing as the magnetic recording density is improved. In particular, the influence of dust on the deterioration of the characteristics of the reproducing element of the magnetic head slider is remarkable. Therefore, it is very important for the reliability of the magnetic recording apparatus to protect the reproducing element of the magnetic head slider from dust and suppress the deterioration of the magnetic characteristics of the reproducing element.

  In the conventional method, dust having a particle size equal to or smaller than the gap at the land portion provided on the inflow end side of the slider floating surface or the defense wall position provided on the inflow end side of the center pad enters the recording / reproducing element portion. Since it is possible, it is still difficult to completely prevent contact between dust and the reproducing element.

  In view of the above-described conventional problems, an object of the present invention is to prevent contact between dust entering the slider air bearing surface and a reproducing element mounted on the slider.

  In order to achieve the above object, a magnetic head slider according to the present invention comprises a slider, a magnetoresistive reproducing element provided on an end face of the slider via an insulating film, and a recording element. A thin film layer in which one end is exposed between the elements on the air bearing surface, the width in the track width direction on the air bearing surface is larger than the combined width of the magnetoresistive effect film and the magnetic domain control film of the reproducing element, and has a lower hardness than the insulating film Have

  The thin film layer is preferably made of the same magnetic material as the lower magnetic shield film of the reproducing element, for example, a NiFe alloy.

  The thin film layer is preferably made of the same magnetic material as the magnetic domain control film of the reproducing element, and is, for example, a CoPt alloy.

  The magnetoresistive film is a TMR film, the lower magnetic shield film also serves as a lower electrode, and the upper magnetic shield film also serves as an upper electrode.

  ADVANTAGE OF THE INVENTION According to this invention, the contact with the dust which invades a slider air bearing surface, and the reproducing element mounted in the slider can be prevented. Thereby, it is possible to suppress the deterioration of the characteristics of the reproducing element and to improve the reliability of the magnetic recording apparatus.

  Before describing the embodiment, a schematic configuration of a magnetic disk drive on which a magnetic head slider according to the present invention is mounted will be described with reference to FIG. The magnetic disk device 100 has a base 102, and a spindle motor (not shown) is fixed to the base 102. A magnetic disk 106 for storing magnetic information is mounted on a spindle (rotating shaft) 104 of the spindle motor, and is rotated. A pivot unit 108 is fixed to the base 102, an arm 110 is attached to the pivot unit 108, a suspension 112 is attached to one end of the arm 110, and the magnetic head slider 1 is held on the suspension 112. The magnetic head slider 1 is given a pressing load against the magnetic disk surface by the suspension 112. The other end of the arm 110 constitutes a holder for the voice coil 116. A magnetic circuit 118 is further fixed to the base 102, and a voice coil 116 is disposed in a magnetic field formed by the magnetic circuit 118. By energizing the voice coil 116, the voice coil 116 receives a force in the magnetic field, the arm 110 swings around the pivot unit 108, and the magnetic head slider 1 moves in the radial direction of the magnetic disk 106 (seek). Let A ramp mechanism 120 is attached to the base 102, and the magnetic head slider 1 is connected to the magnetic disk via a lift tab 114 formed at the tip of the suspension 112 when the apparatus is stopped or when there is no read / write command for a certain time. The lamp mechanism 120 on the outside of 106 is retracted.

  In order to increase the recording density of the magnetic disk apparatus 100 and to increase the capacity or size of the apparatus, the distance between the magnetic head slider 1 and the magnetic disk 106, that is, the slider flying height is reduced, and the linear recording density is reduced. It is effective to raise. In recent years, the slider flying height has been reduced to about 10 nm or less than 10 nm.

  In the above description, the apparatus provided with the load / unload mechanism of the magnetic head slider 1 is shown. However, the magnetic head slider 1 is in a specific area (for example, the inner peripheral side) of the magnetic disk 106 while the apparatus is stopped. A stand-by contact start / stop type magnetic disk device may be used.

Next, the overall configuration of the magnetic head slider according to the embodiment will be described with reference to FIG. FIG. 3 is a perspective view showing the magnetic head slider from the air bearing surface side. The magnetic head slider 1 includes a substrate portion (slider) 1a made of a material represented by a sintered body of alumina and titanium carbide (hereinafter abbreviated as “altic”), and a thin film head portion 1b formed on the end face of the slider 1a. Has been. The thin film head portion 1b includes a thin film layer 4 formed on the end face of the slider 1a by a thin film process, a magnetic reproducing element (hereinafter abbreviated as a reproducing element) 3, a magnetic recording element (hereinafter abbreviated as a recording element) 2, and these elements. An insulating film such as alumina (Al ₂ O ₃ ) formed between and above is formed.

  The slider 1a is, for example, a standard slider called a femto slider, and has a substantially rectangular parallelepiped shape with a length of 0.85 mm, a width of 0.7 mm, and a thickness of 0.23 mm. The air bearing surface 9, the air inflow end surface 11, the air outflow end surface 12, It is comprised from a total of 6 sides, a side surface of both sides, and a back surface.

  The air bearing surface 9 is provided with fine steps (step bearings) by processes such as ion milling and etching, and generates air pressure opposite to a disk (not shown) to support the load applied to the back surface. It plays the role of a bearing. The step is classified into three types of substantially parallel surfaces, the rail surface 5 (5a, 5b, 5c) closest to the disk, and the shallow groove surface 7 (7a) which is a step bearing surface about 100 nm to 200 nm deeper than the rail surface 5. 7b), and the deep groove surface 8 which is deeper than the rail surface 5 by about 1 μm. When the air flow generated by the rotation of the disk enters the rail surfaces 5b and 5c from the shallow groove surface 7b, which is a step bearing, the air flow is compressed by the tapered flow path to generate a positive air pressure. On the other hand, when the air flow enters the deep groove surface 8 from the rail surfaces 5b and 5c or the shallow groove surface 7b, a negative air pressure is generated due to the expansion of the flow path. In FIG. 3, the depth of the groove is emphasized.

  The magnetic head slider 1 is designed to fly in such a posture that the flying height on the air inflow end side is larger than the flying height on the air outflow end side. Therefore, the air bearing surface near the outflow end is closest to the disk. In the vicinity of the outflow end, the rail surface (element installation surface) 5a protrudes from the surrounding shallow groove surface 7a and deep groove surface 8, so that the element is installed unless the slider pitch posture and roll posture are tilted beyond a certain limit. Surface 5a is closest to the disc. The recording element 2, the reproducing element 3, and the thin film layer 4 are formed in a portion belonging to the thin film head portion 1b of the element installation surface 5a. The load on the air bearing surface 9 is balanced so that the load pressed from the suspension 112 and the positive and negative air pressure generated on the air bearing surface 9 are well balanced and the distance from the recording element 2 and the reproducing element 3 to the disk is kept at an appropriate value of about 10 nm. The shape is designed.

  Further, the element mounting surface 5a having the highest possibility of contacting the disk on the air bearing surface 9 is less likely to be worn even if a slight and slight contact with the disk occurs, and the recording element 2 and the reproducing element 3 In order to prevent corrosion, a carbon protective film having a thickness of several nm is formed.

  Here, the slider of the two-step step bearing constituted by the three types of surfaces 5, 7, and 8 in which the air bearing surface 9 is substantially parallel has been described, but the three-step constituted by four or more types of parallel surfaces. The slider of the above step bearing may be sufficient.

  Next, the configuration of the thin film head portion 1b will be described in detail with reference to FIGS. FIG. 1 is an enlarged cross-sectional view of the thin film head portion 1b of the magnetic head slider 1 shown in FIG. 3, taken along the line XX, and FIG. 4 is a schematic view of the reproducing element portion as viewed from the air bearing surface side. As shown in FIG. 1, the thin film head portion 1b includes an insulating film (first insulating film) 13 such as alumina formed on an AlTiC substrate 1a using a thin film process such as sputtering, plating, etching, and polishing. The thin film layer 4 having a hardness lower than that of the first insulating film 13, the insulating film 13 'such as alumina, the magnetoresistive reproducing element 3 for measuring the change in resistance value due to the magnetic field, and the insulating separation such as alumina. The film 14 includes an inductive recording element 2 that records magnetic information by generating a magnetic field between magnetic poles by a current flowing through a coil, and an insulating film (third insulating film) 15 such as alumina covering these elements. Is done. The reproducing element 3 is formed through a lower magnetic shield film 30, an upper magnetic shield film 32, and a gap film (second insulating film) 36 such as alumina between the lower magnetic shield film 30 and the upper magnetic shield film 32. The magnetoresistive effect film (MR film) 34 and the magnetic domain control film 38 (see FIG. 4) provided on both sides of the MR film 34 are formed. The recording element 2 is linked with a closed magnetic circuit composed of the lower magnetic pole 20, the upper magnetic pole 22 magnetically connected to the lower magnetic pole 20 at the rear end, and the lower magnetic pole 20 and the upper magnetic pole 22. The coil 24 is provided, the interlayer insulating film 26 of the coil 24, and a magnetic gap 28 provided at the open end of the lower magnetic pole 20 and the upper magnetic pole 22 on the air bearing surface side. The thin film layer 4 is provided between the first insulating film 13 and the insulating film 13 ′ and is made of, for example, a NiFe alloy of the same material as the lower magnetic shield film 30 or a CoPt alloy of the same material as the magnetic domain control film 38. And has a lower hardness than the first insulating film 13 made of alumina. The end of the thin film layer 4 on the air bearing surface side is exposed to the air bearing surface 9 (5a). As shown in FIG. 4, the width W2 in the track width direction is the width of the MR film 34 and the magnetic domain control films on both sides thereof. It is wider than the total width W1 of 38. The thin film layer 4 plays a role of capturing dust flowing in from the air inflow end side of the slider 1 a before reaching the reproducing element 3.

  A mechanism for capturing dust by the thin film layer 4 will be described with reference to FIGS. FIG. 5 is a side view showing a state in which the magnetic head slider 1 is flying above the magnetic disk 106. Since the distance between the thin film layer 4 exposed on the rail surface 5a and the magnetic disk surface is almost the same as the distance between the reproducing element 3 and the magnetic disk surface, the air bearing surface 9 and the magnetic field from the air inflow end side of the slider 1a. In the thin film head portion 1b, dust having a size large enough to come into contact with the thin film head portion 1b and the magnetic disk 106 comes into contact with the thin film layer 4 before contacting the reproducing element 3. become. The dust 50 is hard particles such as alumina and titanium carbide dropped from the slider 1a, or metal particles such as stainless steel generated from the inside of the magnetic disk, and the dust in question is alumina having high hardness. Since the hardness of the thin film layer 4 is smaller (softer) than the hardness of the first insulating film 13 made of a material such as alumina, the dust 50 that has passed through the first insulating film 13 is thin film layer as shown in FIGS. 4, is captured by the thin film layer 4, and does not reach the reproducing element 3. Therefore, contact between the dust 50 and the reproducing element 3 can be suppressed.

  As shown in FIG. 4, in the scratch indicated by the arrow A1, there is a high possibility that the magnetic reproducing function is damaged by a short circuit among the lower magnetic shield film 30, the magnetic domain control film 38, and the upper magnetic shield film 32. Then, since only the second insulating film 36 exists between the lower magnetic shield film 30 and the upper magnetic shield film 32, the possibility of causing a short circuit between the lower magnetic shield film 30 and the upper magnetic shield film 32 is small, and the magnetic The playback function is not damaged. Therefore, the required dimension of the thin film layer 4 in the track width direction needs to be larger than the width W1 obtained by adding the width of the MR film 34 and the widths of the magnetic domain control films 38 on both sides thereof.

  In particular, in a reproducing element using a TMR film, the magnetic reproducing function is likely to be damaged due to scratch marks from the lower magnetic shield film 30 toward the upper magnetic shield film 32. Therefore, not only the TMR film is protected from dust, but the magnetic domain control film 38 also needs to be protected from scratches caused by dust.

  In the above embodiment, the same material as that of the lower magnetic shield film 30 or the magnetic domain control film 38 is used as the thin film layer 4, but is not limited to these materials, and is softer than the first insulating film 13 such as alumina. As long as it is a material, the same effect as described above can be obtained with any thin film material.

  As described above, according to the magnetic head slider according to the embodiment of the present invention, it is possible to prevent contact between dust entering the slider air bearing surface and the reproducing element mounted on the slider. Thereby, it is possible to suppress the deterioration of the characteristics of the reproducing element and to improve the reliability of the magnetic recording apparatus on which the magnetic head slider is mounted.

It is a cross-sectional enlarged view of a thin film head portion of a magnetic head slider according to an embodiment of the present invention. 1 is a configuration diagram of a magnetic disk device on which a magnetic head slider according to the present invention is mounted. FIG. It is the perspective view seen from the air bearing surface side of the magnetic head slider by the Example of this invention. It is the schematic diagram which looked at the reproducing element part of the magnetic head slider by the Example of this invention from the air bearing surface side. It is a side view which shows a mode that the magnetic head slider by the Example of this invention has floated on the magnetic disc.

Explanation of symbols

1 ... Magnetic head slider,
1a ... slider,
1b: Thin film head part,
2. Recording element,
3 ... reproducing element,
4 ... thin film layer,
5a, 5b, 5c ... rail surface,
7a, 7b ... shallow groove surface,
8 ... Deep groove surface,
9 ... the air bearing surface,
11 ... Air inflow end face,
12 ... Air outflow end face,
13 ... 1st insulating film,
13 '... insulating film,
14 ... Insulating separation membrane,
15 ... Third insulating film,
20 ... bottom pole,
22: Upper magnetic pole,
24 ... Coil,
26 ... interlayer insulating film,
28: Magnetic gap film,
30 ... Lower magnetic shield film,
32. Upper magnetic shield film,
34. MR film (TMR film),
36 ... second insulating film (gap film),
38: Magnetic domain control film.

Claims (10)

A slider,
A reproducing element provided on an end face of the slider via a first insulating film, wherein the magnetic element is disposed between a lower magnetic shield film, an upper magnetic shield film, and the lower magnetic shield film and the upper magnetic shield film. A reproducing element having a resistance effect film and a magnetic domain control film disposed on both sides of the magnetoresistance effect film;
A recording element provided adjacent to the reproducing element, the coil disposed so as to be linked to a closed magnetic circuit composed of a lower magnetic pole, an upper magnetic pole, and the lower magnetic pole and the upper magnetic pole; A recording element having a lower magnetic pole and a magnetic gap formed at the open end of the upper magnetic pole;
A thin film layer provided on the first insulating film between the slider and the reproducing element, one end of which is exposed on the air bearing surface, and the width of the air bearing surface in the track width direction is the magnetoresistive film. A thin film layer that is larger than the combined width of the magnetic domain control films and has a lower hardness than the first insulating film;
A magnetic head slider comprising:   2. The magnetic head slider according to claim 1, wherein the thin film layer is made of the same material as the lower magnetic shield film. The first insulating film is Al ₂ O _3, a magnetic head slider according to claim 1, wherein said thin film layer is a NiFe alloy.   2. The magnetic head slider according to claim 1, wherein the thin film layer is made of the same material as the magnetic domain control film. The first insulating film is Al ₂ O _3, a magnetic head slider according to claim 1, wherein said thin film layer is a CoPt-based alloy.   2. The magnetic head slider according to claim 1, wherein the magnetoresistive film is a TMR film, the lower magnetic shield film is a lower electrode, and the upper magnetic shield film is an upper electrode.   A second insulating film is provided between the lower magnetic shield film and the upper magnetic shield film, and the magnetoresistive film and the magnetic domain control film are disposed in the second insulating film. Item 2. A magnetic head slider according to Item 1. The magnetic head slider according to claim 7, wherein said second insulating film is Al ₂ O _3.   2. The magnetic head slider according to claim 1, wherein the reproducing element and the recording element are covered with a third insulating film. The magnetic head slider according to claim 9, wherein the third insulating film is Al ₂ O ₃ .

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