JP2008140447A - Perpendicular magnetic recording head device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a perpendicular magnetic recording head device capable of improving external magnetic field durability by reducing an Edge Write magnetic field. <P>SOLUTION: The perpendicular magnetic recording head device is provided with: a magnetic layer 24 having a main magnetic pole exposed at an opposite plane to a recording medium M; a return yoke layer 27 provided on the magnetic layer 24 through a non-magnetic layer; and coil layers 18, 23 for giving a recording magnetic field to the magnetic layer 24 and the return yoke layer 27. The return yoke layer 27 has a slit 27d extended from an end part in the width direction of track in plan view to at least the inside and a hole part 27e obstructing a stream of magnetic flux toward the medium opposite plane. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a perpendicular magnetic recording head device that performs recording by applying a magnetic field in a direction perpendicular to the medium surface of a recording medium.

The perpendicular magnetic recording head device has a laminated structure in which a return yoke layer is provided on a surface facing a recording medium (medium facing surface) via a nonmagnetic insulating layer on the main magnetic pole layer. The main magnetic pole layer and the return yoke layer are magnetically connected at the depth in the height direction from the medium facing surface. A coil layer for applying a recording magnetic field to the main magnetic pole layer and the return yoke layer is embedded in the nonmagnetic insulating layer. In the magnetic head device having such a configuration, when a coil layer is energized, a recording magnetic field is induced between the main magnetic pole layer and the return yoke layer, and this recording magnetic field is recorded from the medium facing surface of the main magnetic pole layer to the recording medium. Perpendicularly enters the hard film of the recording medium, returns to the return yoke layer through the soft film of the recording medium. As a result, information is recorded in a region facing the main magnetic pole layer in the recording medium (Patent Document 1).
JP 2005-122831 A

  The return yoke layer and shield layer in a perpendicular magnetic recording head device are generally composed of a substantially rectangular thin film magnetic material. When an external magnetic field in the height direction is applied, the magnetic flux inside the magnetic material is concentrated on the edge of the thin film. To do. At this time, the height direction component is the largest among the magnetization direction components, and this causes overwriting of existing information (Edge Write). That is, in order to reduce the Edge Write magnetic field, it is necessary to reduce the magnetic field of the height direction component generated from the edges of the return yoke layer and the shield layer.

  The present invention has been made in view of this point, and an object of the present invention is to provide a perpendicular magnetic recording head device that can suppress the edge write magnetic field and improve the external magnetic field resistance.

  The perpendicular magnetic recording head device of the present invention is provided with a first magnetic layer having a main magnetic pole exposed at a surface facing a recording medium, and at least a nonmagnetic layer with respect to the magnetic layer, And a second magnetic layer that is wide and a coil layer for applying a recording magnetic field to the first magnetic layer, and the second magnetic layer is at least inward from the end in the track width direction in plan view. It has an extending slit and a magnetic flux flow inhibiting portion that inhibits the flow of magnetic flux toward the medium facing surface.

  According to this configuration, since the slit and the magnetic flux flow blocking portion exist in the second magnetic layer, the flow of magnetic flux in the height direction is prevented by the slit and the magnetic flux flow blocking portion, and magnetic flux concentration occurs at the edge portion of the slit. . For this reason, in the second magnetic layer, the magnetization direction component in the height direction is reduced, and the Edge Write phenomenon is suppressed.

  In the perpendicular magnetic recording head device of the present invention, it is preferable that the magnetic flux flow blocking portion is provided between the innermost portion of the slit and the medium facing surface in plan view.

  In the perpendicular magnetic recording head device of the present invention, it is preferable that the magnetic flux flow blocking portion is a portion having one shape selected from the group consisting of a hole shape, a substantially arch shape, and a thick film shape.

  In the perpendicular magnetic recording head device of the present invention, it is preferable that the slit extends in the depth direction in the plan view.

  The perpendicular magnetic recording head device of the present invention is provided with a first magnetic layer having a main magnetic pole exposed at a surface facing a recording medium, and at least a nonmagnetic layer with respect to the magnetic layer, And a second magnetic layer that is wide and a coil layer for applying a recording magnetic field to the first magnetic layer, and the second magnetic layer is at least inward from the end in the track width direction in plan view. Since it has the extending slit and the magnetic flux flow inhibiting part that inhibits the flow of magnetic flux toward the medium facing surface, the edge write magnetic field can be kept low and the external magnetic field resistance can be improved.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view showing a magnetic head provided with a perpendicular magnetic recording head according to an embodiment of the present invention. FIG. 2 is a partial plan view of the perpendicular magnetic recording head shown in FIG. 1 and a partial front view of the return yoke layer. In FIG. 1, X indicates the track width direction, Y indicates the height direction, and Z indicates the film thickness direction. Each direction is orthogonal to the remaining two directions. In the present embodiment, the case where the magnetic layer having a slit is a return yoke layer will be described.

The perpendicular magnetic recording head H _W shown in FIG. 1, it applies a perpendicular magnetic field to a recording medium M, to magnetize a hard film Ma of the recording medium M in the vertical direction. The recording medium M has, for example, a disk shape, has a hard film Ma with high residual magnetization on its surface, and has a soft film Mb with high magnetic permeability inside, and the center of the disk is the center of rotation. Are configured to rotate.

The slider 10 is made of a nonmagnetic material such as Al ₂ O ₃ .TiC. The facing surface 10a of the slider 10 faces the recording medium M. When the recording medium M rotates, the slider 10 floats from the surface of the recording medium M due to the air flow on the surface, or the slider 10 slides on the recording medium M. To do. A nonmagnetic insulating layer 12 made of an inorganic material such as Al ₂ O ₃ or SiO ₂ is formed on the trailing side end surface (upper surface) 10 b of the slider 10, and a reading unit is formed on the nonmagnetic insulating layer 12. H _R is formed.

Reading portion H _R includes a lower shield layer 13 formed on the nonmagnetic insulating layer 12, and an upper shield layer 16 formed over the inorganic insulating layer (gap insulating layer) 15 on the lower shield layer 13 . These shield layers 13 and 16 are formed wider than the main magnetic pole. A reading element 14 is provided in the inorganic insulating layer 15. As the reading element 14, a magnetoresistive effect element such as an AMR (Anisotropic MagnetoResistance) element, a GMR (Giant MagnetoResistance) element, or a TMR (Tunnel MagnetoResistance) element is used.

  A plurality of lower coil pieces 18 made of a conductive material are formed on the upper shield layer 16 with a coil insulating base layer 17 interposed therebetween. The lower coil piece 18 is made of at least one metal material selected from, for example, Au, Ag, Pt, Cu, Cr, Al, Ti, NiP, Mo, Pd, Rh, and Ni. The lower coil piece 18 may be formed by laminating layers made of these nonmagnetic metal materials.

A coil insulating layer 19 made of an inorganic insulating material such as Al ₂ O ₃ or an organic insulating material such as a resist is formed around the lower coil piece 18. The upper surface of the coil insulating layer 19 is formed flat, a plating underlayer (not shown) is formed on this upper surface, and the main magnetic pole layer 24 is provided on this plating underlayer. The periphery of the main magnetic pole layer 24 is filled with an insulating layer 32 made of Al ₂ O ₃ , SiO ₂ or the like, and is flattened so that the upper surface of the main magnetic pole layer 24 and the upper surface of the insulating layer 32 are substantially in the same plane. Has been processed. The main magnetic pole layer 24 is made of a ferromagnetic material having a high saturation magnetic flux density such as NiFe, CoFe, or NiFeCo, and is formed by plating, for example.

  As shown in FIG. 2, the main magnetic pole layer 24 extends from the facing surface H1a to the recording medium (the facing surface H1a is formed in substantially the same plane as the facing surface 10a of the slider 10) in the height direction (Y direction in the drawing). An elongated front part 24a formed with a track width Tw, and a rear part 24b (maximum width dimension T2) having a wider width dimension in the track width direction (X direction in the drawing) than the front part 24a behind the front part 24a in the height direction. And have.

As shown in FIG. 1, a gap layer 21, which is a nonmagnetic layer made of an inorganic material such as Al ₂ O ₃ or SiO ₂ , is formed on the main magnetic pole layer 24. An upper coil piece 23 is formed on the gap layer 21 with a coil insulating base layer 22 interposed therebetween. Since the gap layer 21 also functions as an insulating base of the upper coil piece 23, the coil insulating base layer 22 may not be formed. Similar to the lower layer coil piece 18, a plurality of upper layer coil pieces 23 are formed of a conductive material. The upper layer coil piece 23 is made of, for example, at least one metal material selected from Au, Ag, Pt, Cu, Cr, Al, Ti, NiP, Mo, Pd, Rh, and Ni. Further, the upper coil piece 23 may be formed by stacking layers made of these nonmagnetic metal materials.

  As shown in FIG. 2, the lower layer coil piece 18 and the upper layer coil piece 23 are arranged in a solenoid shape, and the ends of each coil piece in the track width direction (X direction in the drawing) are electrically connected to each other. The lower layer coil piece 18 and the upper layer coil piece 23 are formed with lead portions 18a and 23a, respectively, and current is supplied from the lead portions 18a and 23a to the solenoid coil.

A coil insulating layer 26 made of an inorganic insulating material such as Al ₂ O ₃ or an organic insulating material such as a resist is formed on the upper layer coil piece 23. In the present embodiment, a gap adjusting insulating layer 28 made of an inorganic material or an organic material is formed on the gap layer 21. The front edge of the coil insulating layer 26 overlaps the interval adjusting insulating layer 28. As shown in FIG. 2, the front edge 28a of the gap adjusting insulating layer 28 extends linearly in a direction substantially parallel to the track width direction (X direction in the drawing). The front edge 28a of the gap adjusting insulating layer 28 is formed away from the facing surface H1a by a predetermined distance (gap depth) L1 in the height direction. As shown in FIG. 2, the gap adjusting insulating layer 28 extends in the track width direction (X direction in the drawing).

  When the solenoid coil layer is used, the width dimension of the upper coil piece 23 in the track width direction is always larger than the maximum width dimension T2 of the main magnetic pole layer 24. Therefore, the coil insulating layer 26 that covers the upper coil piece 23 is used. The maximum width dimension T4 is necessarily larger than the maximum width dimension T2 of the main magnetic pole layer 24. The gap adjusting insulating layer 28 is made of, for example, an organic insulating material and is formed by thermosetting. The vertical cross-sectional shape of the spacing adjustment insulating layer 28 is changed from a rectangular shape to a substantially semi-elliptical shape (or at least the upper surface is curved) by the heat treatment. The coil insulating layer 26 partially overlapped on the gap adjusting insulating layer 28 and formed in the height direction is also made of an organic insulating material and is formed by thermosetting. Is formed so as to rise from the upper surface of the gap adjusting insulating layer 28 into a curved shape. The spacing adjusting insulating layer 28 and the coil insulating layer 26 (hereinafter, these two layers may be referred to as “insulating layer 30”) are located above the reference plane when the upper surface of the gap layer 21 is the reference plane (Z in the figure). Direction). The upper surface of the gap layer 21 is exposed around the insulating layer 30. Hereinafter, a region between the front edge 28a of the spacing adjustment insulating layer 28 and the facing surface H1a is referred to as a front region A, and regions on both sides in the track width direction (X direction in the drawing) of the insulating layer 30 are referred to as both side regions B. .

  As shown in FIGS. 1 and 2, a return yoke layer 27, which is a second magnetic layer made of a magnetic material such as permalloy, is formed on the front region A, the insulating layer 30, and the both side regions B. ing. As shown in FIG. 1, the rear end of the return yoke layer 27 in the height direction is a connection portion 27 c that is magnetically connected to the main magnetic pole layer 24. The return yoke layer 27 is covered with a protective layer 31 made of an inorganic insulating material or the like. Note that the second magnetic layer may be a layer that does not have the connecting portion 27c, that is, a magnetic layer that has a main magnetic pole and has no magnetic coupling and has a simple shielding function. The return yoke layer 27 is formed wider than the main magnetic pole.

  The return yoke layer 27 is formed by a central portion 27a and both end portions 27b located on both sides of the central portion 27a in the track width direction (X direction in the drawing). The central portion 27a is formed at a position facing the main magnetic pole layer 24 in the film thickness direction (Z direction in the drawing). As shown in FIGS. 1 and 2, the central portion 27 a is formed with a protruding portion 27 a 1 that protrudes upward from the insulating layer 30 to the front region A. The return yoke layer 27 formed on the insulating layer 30 is formed so as to protrude from the return yoke layer 27 formed on the both side regions B because the insulating layer 30 is formed so as to be higher than the both side regions B in the first place. The At this time, the film thickness of the return yoke layer 27 formed on the insulating layer 30 and the film thickness of the return yoke layer 27 formed on both side regions B do not change much. In consideration of suppressing the PTP (Pole Tip Protrusion) phenomenon, the thickness of the return yoke layer 27 is preferably 0.1 μm to 1.0 μm.

  As shown in FIG. 3B, the return yoke layer 27 in the perpendicular magnetic recording head according to the present invention has a slit 27d and a hole 27e which is a magnetic flux flow blocking portion. As described above, the magnetic layers such as the return yoke layer and the shield layer are generally composed of a substantially rectangular thin film magnetic body, and when an external magnetic field in the height direction is applied, the magnetic layer is shown in FIG. Thus, the magnetic flux inside the magnetic material is concentrated on the edge of the thin film (X in the figure indicates the magnetic flux concentration portion). At this time, the height direction component becomes the largest among the magnetization direction components, and this causes Edge Write of the existing information. The present inventors pay attention to such points, and in a magnetic layer such as a return yoke layer or a shield layer, in a plan view, a slit extending at least inward from an end in the track width direction, and a medium facing surface It has been found that the edge write phenomenon can be suppressed by reducing the magnetization direction component in the height direction by providing the magnetic flux flow inhibiting portion that inhibits the flow of the magnetic flux toward the present invention.

  In this case, the position and size of the slit 27d and the hole 27e are determined in consideration of suppressing the Edge Write phenomenon while the return yoke layer 27 exhibits a sufficient shielding effect against the main magnetic pole layer 24. Is done. That is, the slit 27d is provided in a region that does not affect the magnetic relationship between the main magnetic pole layer 24 and the return yoke layer 27 in the front portion 24a of the main magnetic pole layer 24, and the magnetic flux flow blocking portion 27e is provided with the slit 27d. It is provided in a region where the magnetic flux flowing through the region narrowed by the presence of is obstructed.

  Considering such requirements, the slit 27d is provided so as to extend at least inward from the end in the track width direction in plan view. The hole 27e is preferably provided between the innermost part of the slit 27d and the medium facing surface in plan view. In this case, as shown in FIG. 3B, the slit 27d is preferably provided so as to extend in the depth direction in the plan view. By doing so, the magnetic flux concentrating portion X can be positioned on the far side (in the height direction far side) from the medium facing surface, and the edge write phenomenon without affecting the front portion 24a of the main magnetic pole layer 24 as much as possible. Can be suppressed. In addition, since the hole 27e exists between the magnetic flux concentrating portion X and the medium facing surface, the flow of magnetic flux passing through the path between the innermost portion 27f of the slit 27d is further inhibited. For this reason, the Edge Write phenomenon can be further suppressed.

  As described above, the return yoke layer 27 is formed with the slit 27d extending at least inward from the end in the track width direction in plan view, and the hole 27e that inhibits the flow of magnetic flux toward the medium facing surface. In the perpendicular magnetic recording head, since the return yoke layer 27 has the slit 27d and the hole 27e, the magnetic flux sucked up in the height direction back side (the back side from the slit) of the return yoke layer 27 is on the front side in the height direction. When flowing to (medium facing surface side), it passes through a path narrowed by the slit 27d. At this time, the magnetic flux concentrates at the innermost edge portion of the slit 27d. Further, the magnetic flux flowing further toward the medium facing surface is hindered by the presence of the hole 27e. Also at this time, the magnetic flux is concentrated at the edge of the hole 27e. Thus, since the magnetic flux passes through the region narrowed by the slit 27d and further bypasses the hole 27e, the path to the medium facing surface becomes relatively long. As a result, the Edge Write phenomenon can be effectively suppressed.

  4A to 4C are diagrams illustrating the shape of the magnetic flux inhibition part. Fig.4 (a) is a perspective view which shows the state cut | disconnected along the IVa-IVa line | wire of FIG.3 (b). 4 (b) and 4 (c) also show a state cut at the position of the IVa-IVa line in FIG. 3 (b).

  About the shape of a magnetic flux flow obstruction part, it is not limited to the shape shown in Drawing 3 (b) and Drawing 4 (a), and can change variously. For example, as shown in FIG. 4 (a), the magnetic flux flow blocking portion may be a hole 27e, and as shown in FIG. 4 (b), an arch portion 27g having a substantially arch shape convex upward. As shown in FIG. 4C, the thick film portion 27h may be convex upward. In the present embodiment, the case where the slits 27d are respectively provided from the ends of the return yoke layer 27 in the track width direction has been described. However, in the present invention, the slits 27d are arranged in any direction in the track width direction. It may be provided at one end.

  The method for providing an arch portion in the return yoke layer can be formed by the method described in Japanese Patent Application No. 2006-199727 of the present applicant. That is, the first resist layer is formed on the gap layer including the coil insulating base layer and the upper coil piece, the second resist layer is formed in the region where the arch portion is to be formed, and the return is performed by plating on the second resist layer. A yoke layer is formed. The return yoke layer is formed in an arch shape along the second resist layer. Further, the method for providing the thick film portion 27h in the return yoke layer can be formed by the method described in Japanese Patent Application No. 2006-199726 of the present applicant. That is, a resist layer is formed on the gap layer including the coil insulating base layer and the upper coil piece, a return yoke layer is formed on the resist layer by a plating process, and an additional plating process is performed on the edge portion of the return yoke layer. A thick film part is formed by applying. These contents are included here.

  Next, examples performed for clarifying the effects of the present invention will be described. In the above configuration, the case where the magnetic layer having the shielding effect is the return yoke layer 27 is described. However, the present invention is a reading element in which the magnetic layer having the shielding effect is the lower shield layer 13 or the upper shield layer 16. The present invention can also be applied to the case of 14 shield layers or other floating shield layers. In this case, the upper shield layer 16 is provided via a nonmagnetic layer with respect to the main magnetic pole layer 24, and the lower shield layer 13 is provided with a nonmagnetic layer, the upper shield layer 16 and the like with respect to the main magnetic pole layer 24. Is provided. For this reason, the case where the magnetic layers were the return yoke layer 27, the lower shield layer 13, and the upper shield 16 was also evaluated.

  Here, the effect was confirmed by a static magnetic field simulation. In this simulation, in the perpendicular magnetic recording head, a part related to external magnetic field resistance was modeled, and the magnetization state when an external magnetic field was applied was calculated. Note that the maximum amount of magnetic field strength is the maximum value of the magnetic field strength distribution in the height direction component generated from the return yoke layer 27, the upper shield layer 16, or the lower shield layer 13. The magnetic field intensity distribution of the height direction component was measured on a plane located at the center of the thickness of the recording magnetic film.

  A return yoke layer 27 provided with a slit 27d extending at least inward from the end in the track width direction in plan view, and a magnetic flux flow blocking portion (hole 27e) for blocking the flow of magnetic flux toward the medium facing surface, The maximum amount of magnetic field strength was determined for a magnetic head including a perpendicular magnetic recording head including the shield layer 16 or the lower shield layer 13. The result is shown in FIG. Further, as a comparative example, the maximum magnetic field strength value is set in the same manner as described above for a magnetic head including a return magnetic layer 27, a top shield layer 16 or a bottom shield layer 13 and a perpendicular magnetic recording head that does not have a slit and a magnetic flux flow blocking portion. Asked. The results are also shown in FIG.

As can be seen from FIG. 5, in the magnetic head (Example) provided with the perpendicular magnetic recording head according to the present invention, slits and holes are provided in any of the return yoke layer 27, the upper shield layer 16 and the lower shield layer 13. However, the magnetic field strength is ³ kOe (× 10 ³ / 4π A / m) or less (2 kOe or less when provided in the upper shield layer 16 or the lower shield layer 13), and the external magnetic field resistance can be improved. On the other hand, with respect to a magnetic head (comparative example) having a perpendicular magnetic recording head having no slit in the magnetic layer, the maximum magnetic field strength is close to 4 kOe (× 10 ³ / 4π A / m) (upper shield layer 16 and lower shield When the layer 13 is provided, the edge write is generated depending on the coercive force (Hc) of the recording medium.

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. For example, there are no particular restrictions on the numerical values, materials, member shapes, particularly slits and holes described in the above embodiments. Other modifications may be made as appropriate without departing from the scope of the object of the present invention.

1 is a longitudinal sectional view showing a magnetic head including a perpendicular magnetic recording head according to an embodiment of the present invention. FIG. 2 is a partial plan view of the perpendicular magnetic recording head shown in FIG. 1 and a partial front view of a return yoke layer. (A), (b) is a figure for demonstrating the magnetic flux concentration in a magnetic layer. (A)-(c) is a figure which shows the shape of the slit and magnetic flux flow inhibition part which are formed in a magnetic layer. It is a figure which shows the magnetic characteristic of a perpendicular magnetic recording head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Slider 12 Nonmagnetic insulating layer 13 Lower shield layer 14 Reading element 15 Inorganic insulating layer 16 Upper shield layer 18 Lower layer coil piece 21 Gap layer 23 Upper layer coil piece 24 Main magnetic pole layer 24a Front part 26 Coil insulation layer 27 Return yoke layer 27c Connection Part 27d slit 27e hole part 27f innermost part 27g arch part 27h thick film part 28 gap adjustment insulating layer

Claims (4)

  A first magnetic layer having a main magnetic pole exposed at a surface facing the recording medium; a second magnetic layer provided at least through a nonmagnetic layer with respect to the magnetic layer and having a width wider than the main magnetic pole; A coil layer for applying a recording magnetic field to the first magnetic layer, and the second magnetic layer includes a slit extending at least inward from an end in the track width direction in plan view, and a medium facing surface. A perpendicular magnetic recording head device, comprising: a magnetic flux flow inhibition unit that inhibits a flow of magnetic flux toward the magnetic flux head.   2. The perpendicular magnetic recording head device according to claim 1, wherein the magnetic flux flow blocking portion is provided between the innermost portion of the slit and the medium facing surface in plan view.   3. The perpendicular magnetic recording head according to claim 1, wherein the magnetic flux flow blocking portion is a portion having one shape selected from the group consisting of a hole shape, a substantially arch shape, and a thick film shape. apparatus.   4. The perpendicular magnetic recording head device according to claim 1, wherein the slit extends in a depth direction in a plan view. 5.

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