JP2012104217A - Magnetic head, and disk device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic head capable of enhancing recording density by increasing a write margin, and to provide a disk device having the same.SOLUTION: The magnetic head of the disk device includes: a main magnetic pole 66 for applying a perpendicular recording magnetic field to a recording layer 23 of a recording medium 12; a return magnetic pole 68 which faces the trailing side of the main magnetic pole with a write gap and forms a magnetic circuit together with the main magnetic pole; a coil 65 for exciting a magnetic flux in the magnetic circuit formed by the main magnetic pole and the return magnetic pole; a plurality of high-frequency oscillation elements 70a, 70b which are provided between the main magnetic pole and the return magnetic pole, respectively, have a plurality of magnetic films having different magnetic resonance frequencies, and apply high-frequency magnetic fields to the recording medium, respectively; and an electrical circuit 80 for energizing the high-frequency oscillation elements.

Description

  Embodiments described herein relate generally to a magnetic head for perpendicular magnetic recording used in a disk device, and a disk device including the magnetic head.

  As a disk device, for example, a magnetic disk device includes a magnetic disk disposed in a case, a spindle motor that supports and rotates the magnetic disk, a magnetic head that reads / writes information from / to the magnetic disk, and a magnetic device. A carriage assembly that movably supports the head with respect to the magnetic disk. The carriage assembly includes an arm rotatably supported and a suspension extending from the arm, and a magnetic head is supported on the extended end of the suspension. The magnetic head includes a slider attached to the suspension and a head portion provided on the slider, and the head portion includes a write recording head and a read reproducing head.

  In recent years, magnetic heads for perpendicular magnetic recording have been proposed in order to increase the recording density, capacity, and size of magnetic disk devices. In such a magnetic head, the recording head includes a main magnetic pole that generates a vertical magnetic field and a return magnetic pole that is disposed with a write gap on the trailing side of the main magnetic pole and closes the magnetic path between the magnetic disk, Or it has a write shield magnetic pole and a coil for flowing magnetic flux to the main magnetic pole.

  For the purpose of improving the recording density, a high frequency magnetic field assisted recording type magnetic head has been proposed in which a high frequency oscillation element is provided between the main magnetic pole and the return magnetic pole, and a high frequency magnetic field is applied from the high frequency oscillation element to the magnetic recording layer. Yes.

JP 2009-80904 A JP 2010-20835 A

  However, even in the magnetic head configured as described above, the write margin for the recording area is insufficient, and when the recording density is increased, the adjacent recording area may be reversed in magnetization to cause a write error.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a magnetic head capable of improving the recording density by improving the write margin, and a disk device including the same. .

  A magnetic head according to an aspect of the present invention has a main magnetic pole that applies a recording magnetic field perpendicular to a recording layer of a recording medium, and a magnetic gap from the main magnetic pole that faces the trailing side of the main magnetic pole with a write gap. A return magnetic pole that forms a magnetic circuit together with the main magnetic pole, a coil that excites magnetic flux in the magnetic circuit formed by the main magnetic pole and the return magnetic pole, and the main magnetic pole and the return magnetic pole, respectively. A plurality of high-frequency oscillation elements each having a plurality of magnetic films having different magnetic resonance frequencies and applying a high-frequency magnetic field to the recording medium; and an electric circuit for energizing the high-frequency oscillation elements.

  According to the aspects of the present invention, it is possible to provide a magnetic head capable of increasing the write margin and improving the recording density, and a disk device including the magnetic head.

FIG. 1 is a perspective view showing an HDD according to a first embodiment of the present invention. FIG. 2 is a side view showing a magnetic head and a suspension in the HDD. FIG. 3 is an enlarged sectional view showing a head portion of the magnetic head. FIG. 4 is a perspective view schematically showing a recording head of the magnetic head. FIG. 5 is a sectional view of a magnetic disk in the HDD. FIG. 6 is a plan view showing a recording layer of the magnetic disk. FIG. 7 is an enlarged cross-sectional view of the magnetic disk side end of the recording head and the magnetic disk. FIG. 8 is a plan view of the recording head portion as viewed from the ABS side of the slider. FIG. 9 is a diagram schematically illustrating a recording operation by the recording head. FIG. 10 is a diagram comparing the relationship between the linear recording density and the bit error rate for the magnetic head according to the comparative example and the magnetic head according to the present embodiment. FIG. 11 is a perspective view schematically showing a recording head of a magnetic head in the HDD according to the second embodiment. FIG. 12 is a plan view of the recording head according to the second embodiment viewed from the ABS side. FIG. 13 is a perspective view schematically showing a recording head of a magnetic head in the HDD according to the third embodiment. FIG. 14 is a plan view of the recording head according to the third embodiment as viewed from the ABS side. FIG. 15 is a perspective view schematically showing a recording layer of a magnetic disk in the HDD according to the fourth embodiment. FIG. 16 is a plan view schematically showing a recording layer of a magnetic disk in the HDD according to the fourth embodiment. FIG. 17 is a perspective view schematically showing a recording layer of a magnetic disk in the HDD according to the fifth embodiment. FIG. 18 is a plan view schematically showing a recording layer of a magnetic disk in the HDD according to the fifth embodiment. FIG. 19 is a perspective view schematically showing a recording layer of a magnetic disk in the HDD according to the sixth embodiment. FIG. 20 is a plan view schematically showing a recording layer and a recording head of a magnetic disk in the HDD according to the sixth embodiment. FIG. 21 is a plan view schematically showing a recording layer and a recording head of a magnetic disk in the HDD according to the sixth embodiment.

  Hereinafter, a hard disk drive (hereinafter referred to as an HDD) according to a first embodiment will be described in detail as a disk device with reference to the drawings.

  FIG. 1 shows the internal structure with the top cover of the HDD removed, and FIG. 2 shows the magnetic head in a floating state. As shown in FIG. 1, the HDD includes a housing 10. The housing 10 includes a rectangular box-shaped base 11 having an open top surface and a rectangular plate-shaped top cover (not shown). The top cover is screwed to the base with a plurality of screws, and closes the upper end opening of the base. As a result, the inside of the housing 10 is kept airtight and can be ventilated to the outside only through the breathing filter 26. The base 11 and the top cover are made of a metal material such as aluminum, iron, stainless steel, or a cold rolled carbon steel plate.

  On the base 11, a magnetic disk 12 as a recording medium and a mechanism unit are provided. The mechanism unit includes a spindle motor 13 that supports and rotates the magnetic disk 12, a plurality of, for example, two magnetic heads 33 that record and reproduce information on the magnetic disk, and these magnetic heads 33 on the surface of the magnetic disk 12. A head actuator 14 movably supported on the head and a voice coil motor (hereinafter referred to as VCM) 16 for rotating and positioning the head actuator are provided. On the base 11, when the magnetic head 33 moves to the outermost periphery of the magnetic disk 12, when an impact or the like is applied to the ramp load mechanism 18 that holds the magnetic head 33 at a position away from the magnetic disk 12, or the HDD. An inertia latch mechanism 20 that holds the head actuator 14 in the retracted position, and a substrate unit 17 on which electronic components such as a preamplifier and a head IC are mounted are provided.

A control circuit board 25 is screwed to the outer surface of the base 11 and is positioned to face the bottom wall of the base 11. The control circuit board 25 controls the operations of the spindle motor 13, the VCM 16 and the magnetic head 33 through the board unit 17. As shown in FIG. 1, the magnetic disk 12 is coaxially fitted to the hub of the spindle motor 13. And clamped by a clamp spring 15 screwed to the upper end of the hub and fixed to the hub. The magnetic disk 12 is rotationally driven in the direction of arrow B at a predetermined speed by a spindle motor 13 as a drive motor.

  The head actuator 14 includes a bearing portion 24 fixed on the bottom wall of the base 11 and a plurality of arms 27 extending from the bearing portion. These arms 27 are positioned parallel to the surface of the magnetic disk 12 and at a predetermined interval from each other, and extend from the bearing portion 24 in the same direction. The head actuator 14 includes an elongated plate-like suspension 30 that can be elastically deformed. The suspension 30 is configured by a leaf spring, and the base end thereof is fixed to the distal end of the arm 27 by spot welding or adhesion, and extends from the arm. Each suspension 30 may be formed integrally with the corresponding arm 27. A magnetic head 33 is supported on the extended end of each suspension 30. The arm 27 and the suspension 30 constitute a head suspension, and the head suspension and the magnetic head 33 constitute a head suspension assembly.

  As shown in FIG. 2, each magnetic head 33 has a substantially rectangular parallelepiped slider 42 and a recording / reproducing head portion 44 provided at the outflow end (trailing end) of the slider. The magnetic head 33 is fixed to a gimbal spring 41 provided at the tip of the suspension 30. Each magnetic head 33 is applied with a head load L toward the surface of the magnetic disk 12 due to the elasticity of the suspension 30. The two arms 27 are positioned in parallel with each other at a predetermined interval, and the suspension 30 and the magnetic head 33 attached to these arms face each other with the magnetic disk 12 in between.

  Each magnetic head 33 is electrically connected to a main FPC 38 to be described later via a relay flexible printed circuit board (hereinafter referred to as a relay FPC) 35 fixed on the suspension 30 and the arm 27.

  As shown in FIG. 1, the board unit 17 has an FPC main body 36 formed of a flexible printed circuit board and a main FPC 38 extending from the FPC main body. The FPC main body 36 is fixed on the bottom surface of the base 11. Electronic components including a preamplifier 37 and a head IC are mounted on the FPC main body 36. The extended end of the main FPC 38 is connected to the head actuator 14 and is connected to the magnetic head 33 via each relay FPC 35.

  The VCM 16 includes a support frame (not shown) extending from the bearing portion 24 in the direction opposite to the arm 27, and a voice coil supported by the support frame. In a state where the head actuator 14 is incorporated in the base 11, the voice coil is positioned between a pair of yokes 34 fixed on the base 11, and constitutes the VCM 16 together with these yokes and magnets fixed to the yokes.

  By energizing the voice coil of the VCM 16 while the magnetic disk 12 is rotated, the head actuator 14 is rotated, and the magnetic head 33 is moved and positioned on a desired track of the magnetic disk 12. At this time, the magnetic head 33 is moved between the inner peripheral edge and the outer peripheral edge of the magnetic disk along the radial direction of the magnetic disk 12.

  Next, the configuration of the magnetic disk 12 and the magnetic head 33 will be described in detail. 3 is an enlarged sectional view showing the head portion 44 of the magnetic head 33, FIGS. 5 and 6 are perspective views and plan views schematically showing the recording layer of the magnetic disk 12, and FIG. It is sectional drawing which expands and shows the edge part by the side of a magnetic disc, and a magnetic disc.

  As shown in FIGS. 1 and 2, the magnetic disk 12 includes a substrate 19 made of a nonmagnetic material and formed in a disk shape having a diameter of about 2.5 inches, for example. As shown in FIG. 2 to FIG. 4, on each surface of the substrate 19, a soft magnetic layer 21 as an underlayer, a nonmagnetic layer 22 for controlling orientation on the upper layer, and a perpendicular to the disk surface are provided. A magnetic recording layer 23 having magnetic anisotropy in the direction and a protective layer 31 formed as the uppermost layer are formed.

  As shown in FIGS. 5, 6, and 7, the magnetic recording layer 23 includes a plurality of magnetic dots 50 and 51 formed of a plurality of magnetically separated magnetic materials having different magnetic resonance frequencies, for example, two types of ferromagnetic materials. And a non-magnetic substance 53 that fills the space between the separated magnetic dots 50 and 51. Two types of magnetic dots 50 and 51 having different resonance frequencies are alternately arranged along the circumferential direction of the magnetic disk 12, that is, along the rotation direction B. Further, the magnetic dots 50 and 51 are provided alternately in the radial direction of the magnetic disk 12.

  As shown in FIGS. 2 and 3, the magnetic head 33 is configured as a floating type head, and has a slider 42 formed in a substantially rectangular parallelepiped shape, and a head formed at an end portion on the outflow end (trailing) side of the slider. Part 44. The slider 42 is formed of, for example, a sintered body (altic) of alumina and titanium carbide, and the head portion 44 is formed of a thin film.

  The slider 42 has a rectangular disk-facing surface (air support surface (ABS surface)) 43 that faces the surface of the magnetic disk 12. The slider 42 floats by the air flow C generated between the disk surface and the disk facing surface 43 by the rotation of the magnetic disk 12. The direction of the air flow C coincides with the rotation direction B of the magnetic disk 12. The slider 42 is arranged so that the longitudinal direction of the disk facing surface 43 substantially coincides with the direction of the air flow C with respect to the surface of the magnetic disk 12.

  The slider 42 has a leading end 42a located on the air flow C inflow side and a trailing end 42b located on the air flow C outflow side. A reading step, a trailing step, a side step, a negative pressure cavity, and the like (not shown) are formed on the disk facing surface 43 of the slider 42.

  As shown in FIG. 3, the head portion 44 has a reproducing head 54 and a recording head 56 formed by a thin film process at the trailing end portion 42b of the slider 42, and is formed as a separation type magnetic head.

  The reproducing head 54 is composed of a magnetic film 63 exhibiting a magnetoresistive effect, and shield films 62a and 62b arranged so as to sandwich the magnetic film 63 between the trailing side and the leading side of the magnetic film. The lower ends of the magnetic film 63 and the shield films 62 a and 62 b are exposed on the disk facing surface 43 of the slider 42.

  The recording head 56 is provided on the trailing end 42 b side of the slider 42 with respect to the reproducing head 54. The recording head 56 is configured as a single magnetic pole head having a return magnetic pole on the trailing end side.

  FIG. 8 is a layout view of the recording head portion as viewed from the ABS surface 43 side of the slider 42. As shown in FIGS. 3, 4, 7, and 8, the recording head 56 includes a main magnetic pole 66 made of a high permeability material that generates a recording magnetic field perpendicular to the surface of the magnetic disk 12, and a main magnetic pole. 66, a return magnetic pole (write shield electrode) 68 disposed on the trailing side of 66 and provided to close the magnetic path efficiently via the soft magnetic layer 21 directly under the main magnetic pole, and when writing a signal to the magnetic disk 12 And a recording coil 65 arranged so as to be wound around a magnetic magnetic path including the main magnetic pole 66 and the return magnetic pole 68 in order to cause a magnetic flux to flow through the main magnetic pole 66.

  The main magnetic pole 66 extends substantially perpendicular to the surface of the magnetic disk 12. A tip 66a of the main magnetic pole 66 on the magnetic disk 12 side is narrowed down toward the disk surface. As shown in FIG. 8, the tip 66a of the main magnetic pole 66 has a trapezoidal cross section, for example, and faces a trailing side end surface 67a and a trailing end surface having a predetermined width located on the trailing end side. In addition, it has a leading side end surface 67b that is narrower than the trailing side end surface. The leading end surface of the main magnetic pole 66 is exposed on the disk facing surface 43 of the slider 42.

  The return magnetic pole 68 is formed in an approximately L shape, and its tip end portion 68a is formed in an elongated rectangular shape. The tip surface of the return magnetic pole 68 is exposed on the disk facing surface 43 of the slider 42. The leading end surface 68b of the tip 68a extends along the track width direction of the magnetic disk 12. The leading side end surface 68b faces the trailing side end surface 67a of the main pole 66 in parallel with the write gap WG therebetween.

  As shown in FIGS. 7 and 8, the recording head 56 includes a plurality of, for example, two spin torque oscillators 70 a and 70 b provided between the surfaces where the tip 66 a of the main magnetic pole 66 and the return magnetic pole 68 are opposed to each other. It has. Spin torque oscillators 70a and 70b as high-frequency magnetic field oscillation elements are arranged substantially in parallel between the trailing side end surface 67a of the tip 66a of the main magnetic pole 66 and the leading side end surface 68b of the return magnetic pole 68, and in the track width direction. Magnetically spaced apart.

  The spin torque oscillator 70a is configured by laminating a nonmagnetic layer 71a, an oscillation layer 72a, an intermediate layer 73a, a spin injection layer 74a, and a nonmagnetic layer 76a in order from the return magnetic pole 68 side to the main magnetic pole 66 side. Similarly, the spin torque oscillator 70b is configured by laminating a nonmagnetic layer 71b, an oscillation layer 72b, an intermediate layer 73b, a spin injection layer 74b, and a nonmagnetic layer 76b in order from the return magnetic pole 68 side to the main magnetic pole 66 side. Yes. The oscillation layers 72a and 72b of the spin torque oscillators 70a and 70b are formed of oscillation layers having different magnetic resonance frequencies. The resonance oscillation frequency of the oscillation layer 72a of the spin torque oscillator 70a is set to the resonance oscillation frequency corresponding to the magnetic dot 50 of the magnetic disk 12, and the resonance oscillation frequency of the oscillation layer 72b of the spin torque oscillator 70b is The resonance oscillation frequency corresponding to the magnetic dot 51 of the magnetic disk 12 is set.

  Here, the two oscillation layers 72a and 72b having different magnetic resonance frequencies may be formed of different ferromagnets, or may be made of a common ferromagnet and different volumes. The order of stacking the films 71 a, 71 b, 72 a, 72 b, 73 a, 73 b, 74 a, 74 b, 75 a, 75 b may be reversed with respect to the traveling direction of the magnetic head 33.

  The tips of the spin torque oscillators 70 a and 70 b are exposed at the ABS surface 43, and are provided at the same height as the tip surface of the main pole 66 with respect to the surface of the magnetic disk 12. The spin torque oscillators 70 a and 70 b are controlled by an electric circuit 80 connected between the main magnetic pole 66 and the return magnetic pole 68, and apply a high frequency magnetic field to the magnetic disk 12.

  As shown in FIG. 3, the reproducing head 54 and the recording head 56 are covered with a protective insulating film 82 except for a portion exposed to the ABS surface 43 of the slider 42. The protective insulating film 82 constitutes the outer shape of the head portion 44.

  According to the HDD configured as described above, by driving the VCM 16, the head actuator 14 is rotated, and the magnetic head 33 is moved and positioned on a desired track of the magnetic disk 12. Further, the magnetic head 33 floats by the air flow C generated between the disk surface and the disk facing surface 43 by the rotation of the magnetic disk 12. During the operation of the HDD, the disk facing surface 43 of the slider 42 faces the disk surface with a gap. As shown in FIG. 2, the magnetic head 33 floats in an inclined posture in which the recording head 56 portion of the head portion 44 is closest to the surface of the magnetic disk 12. In this state, the recording information is read from the magnetic disk 12 by the reproducing head 54 and the information is written by the recording head 56.

  In writing information, a direct current is applied to the spin torque oscillators 70 a and 70 b from the electric circuit 80 to generate a high frequency magnetic field, and this high frequency magnetic field is applied to the magnetic recording layer 23 of the magnetic disk 12. Further, the main magnetic pole 66 is excited by the recording coil 65, and information is recorded with a desired track width by applying a perpendicular recording magnetic field from the main magnetic pole to the recording layer 23 of the magnetic disk 12 immediately below. By superimposing a high-frequency magnetic field on the recording magnetic field, magnetic recording with high coercive force and high magnetic anisotropy energy can be performed.

  With reference to FIG. 9, the recording operation of the recording head 56 in the HDD of this embodiment will be described. FIG. 9A shows the initial dot state of the magnetic disk 12 before the recording head 56 travels. For example, the magnetic dots 50 and 51 are magnetized substantially vertically downward with respect to the surface of the recording layer 23. FIG. 9B shows that the recording gate 56 passes the current Iw1 for transmitting the spin torque oscillator 70a to the electric circuit 80 by the recording gates g1, g2, and g3, and at the same time, the recording current flows to the recording coil 65. A current gate diagram is shown. In this case, as shown in FIG. 9C, after the spin torque oscillator 70a is positioned with respect to the magnetic disk 12 of the recording head 56 so as to face the desired track, the spin torque oscillator 70a of the recording head 56 is used. As shown in FIG. 9D, the magnetization of the magnetic dot 50 having the same resonance oscillation frequency as that of the spin torque oscillator 70a is reversed by the high frequency magnetic field. Here, even if the recording gate timing is applied to the adjacent magnetic dot 51, the magnetic dot 51 does not resonate, and therefore, magnetization reversal does not occur. Therefore, a desired signal is written only to the magnetic dots 50 of the magnetic disk 12 by the recording head 56.

  FIG. 9E shows that the recording gate 56 is supplied with the current Iw2 for transmitting the spin torque oscillator 70b to the electric circuit 80 by the recording gates g4, g5 and g6, and simultaneously the recording current is supplied to the recording coil 65. A current gate diagram is shown. As shown in FIG. 9F, after the spin torque oscillator 70b is positioned with respect to the magnetic disk 12 of the recording head 56 so as to face a desired track, the spin torque oscillator 70b of the recording head 56 oscillates. As shown in FIG. 9G, the magnetization of the magnetic dot 51 having the same resonant oscillation frequency as that of the spin torque oscillator 70b is reversed by the high-frequency magnetic field. Here, even if the recording gate timing is applied to the adjacent magnetic dot 50, the magnetic dot 50 does not resonate, so that magnetization reversal does not occur. Therefore, a desired signal is written only to the magnetic dots 51 of the magnetic disk 12 by the recording head 56.

  As described above, in the related art, there is a range in which a current can flow only for one magnetic dot, that is, a write margin, whereas in the magnetic head 33 according to the present embodiment, the number of magnets is equal to the number of spin torque oscillators. The light margin can be allowed by the amount of dots. That is, according to the present embodiment, a write margin of two adjacent magnetic dots 50 and 51 can be obtained. As a result, it is possible to prevent erasure of adjacent magnetic dots while ensuring the recording capability on the write track, and the linear recording density of the magnetic disk 12 can be improved.

  The inventor prepares the magnetic head 33 according to the present embodiment and the magnetic head according to the comparative example, and the signal error rate (bit error rate) when recording / reproducing is performed using these magnetic heads. Compared. The comparative example is a magnetic head having a single spin torque oscillator, and the recording layer of the magnetic disk is also formed of a ferromagnetic material having a single magnetic resonance frequency.

  FIG. 10 shows an evaluation result of the relationship between the linear recording density and the bit error rate compared with the present embodiment and the comparative example. In the magnetic head of the comparative example, when the linear recording density is low, the bit error rate is almost the same as in this embodiment, but when the linear recording density is high and the bit length is small, bit errors are likely to occur. It can be seen that the error rate rapidly deteriorates. According to the magnetic head of the HDD according to the present embodiment, the occurrence of bit errors is suppressed even in high linear density recording, and it can be seen that the deterioration of the error rate is improved.

Next, a magnetic head of an HDD according to another embodiment of the present invention will be described.
In a plurality of other embodiments described below, the same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted.

  FIG. 11 is a perspective view schematically showing the recording head 56 of the magnetic head in the HDD according to the second embodiment, and FIG. 12 is a plan view of the recording head viewed from the ABS side of the slider.

  As shown in FIGS. 11 and 12, according to the second embodiment, the main magnetic pole 66 of the recording head 56 is composed of two main magnetic poles (each made of a high permeability material and magnetically separated in the track width direction). The first and second main magnetic poles) 84a and 84b are formed in a tapered shape whose tip is narrowed toward the magnetic disk surface as a whole. The tip of each main magnetic pole has a trapezoidal cross section, for example, a trailing side end surface with a predetermined width located on the trailing end side, is opposed to the trailing end surface and is wider than the trailing side end surface. It has a narrow leading end face. The front end surfaces of the main magnetic poles 84 a and 84 b are exposed on the ABS surface 43 of the slider 42.

  The recording head 56 is disposed on the trailing side of the main magnetic poles 84a and 84b, and is provided on the magnetic disk 12 with a return magnetic pole 68 provided to efficiently close the magnetic path via the soft magnetic layer 21 directly below the main magnetic pole. And a recording coil 65 arranged so as to be wound around a magnetic magnetic path including the main magnetic pole and the return magnetic pole 68 in order to cause a magnetic flux to flow through the main magnetic poles 84a and 84b.

  The return magnetic pole 68 is formed in an approximately L shape, and its tip end portion 68a is formed in an elongated rectangular shape. The tip surface of the return magnetic pole 68 is exposed on the ABS surface 43 of the slider 42. The leading end surface 68b of the tip 68a extends along the track width direction of the magnetic disk 12. This leading side end face 68b faces the trailing side end faces of the main magnetic poles 84a, 84b in parallel with the write gap WG therebetween.

  The recording head 56 includes a spin torque oscillator 70a provided between a surface where the tip of the main magnetic pole 84a and the return magnetic pole 68 face each other, and a surface where the tip of the main magnetic pole 84b and the return magnetic pole 68 face each other. A spin torque oscillator 70b provided therebetween is provided. The spin torque oscillators 70a and 70b as high-frequency magnetic field oscillation elements are provided between the main magnetic pole 66 and the return magnetic pole 68 substantially in parallel and magnetically separated in the track width direction.

  The spin torque oscillator 70a is formed by laminating a nonmagnetic layer 71a, an oscillation layer 72a, an intermediate layer 73a, a spin injection layer 74a, and a nonmagnetic layer 76a in this order from the return magnetic pole 68 side to the main magnetic pole 84a side. Similarly, the spin torque oscillator 70b is configured by laminating a nonmagnetic layer 71b, an oscillation layer 72b, an intermediate layer 73b, a spin injection layer 74b, and a nonmagnetic layer 76b in order from the return magnetic pole 68 side to the main magnetic pole 84b side. Yes. The oscillation layers 72a and 72b of the spin torque oscillators 70a and 70b are formed of oscillation layers having different magnetic resonance frequencies. The resonance oscillation frequency of the oscillation layer 72a of the spin torque oscillator 70a is set to the resonance oscillation frequency corresponding to the magnetic dot 50 of the magnetic disk 12, and the resonance oscillation frequency of the oscillation layer 72b of the spin torque oscillator 70b is The resonance oscillation frequency corresponding to the magnetic dot 51 of the magnetic disk 12 is set.

  Here, the two oscillation layers 72a and 72b having different magnetic resonance frequencies may be formed of different ferromagnets, or may be made of a common ferromagnet and different volumes. The order of stacking the films 71 a, 71 b, 72 a, 72 b, 73 a, 73 b, 74 a, 74 b, 75 a, 75 b may be reversed with respect to the traveling direction of the magnetic head 33.

  The tips of the spin torque oscillators 70 a and 70 b are exposed at the ABS surface 43, and are provided at the same height as the tip surface of the main pole 66 with respect to the surface of the magnetic disk 12. The magnetic head 33 includes an electric circuit 80a for flowing current to the main magnetic pole 84a, the spin torque oscillator 70a, and the return magnetic pole 68, and an electric circuit for flowing current to the main magnetic pole 84b, the spin torque oscillator 70b, and the return magnetic pole 68. 80b. The spin torque oscillator 70a is controlled by an electric circuit 80a and applies a high frequency magnetic field to the magnetic disk 12 when a current is supplied. The spin torque oscillator 70b is controlled by the electric circuit 80b and applies a high-frequency magnetic field to the magnetic disk 12 when a current is supplied.

  Also in the second embodiment configured as described above, it is possible to provide a magnetic head capable of increasing the linear recording density by improving the write margin, and a disk device including the same. In addition, it is possible to separately supply drive currents from the electric circuits 80a and 80b independent of the spin torque oscillators 70a and 70b, respectively, and to oscillate the spin torque oscillators more reliably.

  FIG. 13 is a perspective view schematically showing the recording head 56 of the magnetic head in the HDD according to the third embodiment, and FIG. 14 is a plan view of the recording head viewed from the ABS side of the slider.

  As shown in FIGS. 13 and 14, according to the third embodiment, the recording head 56 has a main magnetic pole 66 formed of a high magnetic permeability material, and the main magnetic pole has a leading end toward the magnetic disk surface. It is formed in a tapered shape with the portion narrowed down. The tip of the main magnetic pole 66 has a trapezoidal cross section, for example, a trailing side end surface with a predetermined width located on the trailing end side, is opposed to the trailing end surface and is wider than the trailing side end surface. It has a narrow leading end face. The front end surface of the main magnetic pole 66 is exposed on the ABS surface 43 of the slider 42.

  The recording head 56 is disposed on the trailing side of the main magnetic pole 66, and a return magnetic pole 68 provided for efficiently closing the magnetic path via the soft magnetic layer 21 directly below the main magnetic pole 66, and a signal to the magnetic disk 12. And a recording coil arranged so as to be wound around a magnetic magnetic path including the main magnetic pole 66 and the return magnetic pole 68 in order to flow a magnetic flux to the main magnetic pole 66 when writing.

  The recording head 56 includes a plurality of, for example, two spin torque oscillators 70 a and 70 b provided between the surfaces of the main magnetic pole 66 and the return magnetic pole facing each other. Spin torque oscillators 70 a and 70 b as high-frequency magnetic field oscillation elements are provided in a line in the track direction between the tip of the main magnetic pole 66 and the leading end face of the return magnetic pole 68.

  The spin torque oscillator 70a is configured by laminating a nonmagnetic layer 71a, an oscillation layer 72a, an intermediate layer 73a, and a spin injection layer 74 in order from the return magnetic pole 68 side to the main magnetic pole 66 side. The spin torque oscillator 70b is formed by laminating a nonmagnetic layer 71b, an oscillation layer 72b, an intermediate layer 73b, and a spin injection layer 74 in order from the main magnetic pole 66 side to the return magnetic pole 68 side. The spin injection layer 74 is shared by the spin torque oscillators 70a and 70b. The resonance oscillation frequency of the oscillation layer 72a of the spin torque oscillator 70a is set to the resonance oscillation frequency corresponding to the magnetic dot 50 of the magnetic disk 12, and the resonance oscillation frequency of the oscillation layer 72b of the spin torque oscillator 70b is The resonance oscillation frequency corresponding to the magnetic dot 51 of the magnetic disk 12 is set.

  Here, the two oscillation layers 72a and 72b having different magnetic resonance frequencies may be formed of different ferromagnets, or may be made of a common ferromagnet and different volumes. The order of stacking the films 71 a, 71 b, 72 a, 72 b, 73 a, 73 b, 74, 75 a, 75 b may be reversed with respect to the traveling direction of the magnetic head 33.

  The tips of the spin torque oscillators 70 a and 70 b are exposed at the ABS surface 43, and are provided at the same height as the tip surface of the main pole 66 with respect to the surface of the magnetic disk 12. The magnetic head 33 includes an electric circuit 80a for flowing current to the main magnetic pole 66, the spin torque oscillator 70a, and the return magnetic pole 68, and an electric circuit for flowing current to the main magnetic pole 66, the spin torque oscillator 70b, and the return magnetic pole 68. A circuit 80b and a switch 80c for switching these electric circuits are provided. The spin torque oscillator 70a is controlled by an electric circuit 80a and applies a high frequency magnetic field to the magnetic disk 12 when a current is supplied. The spin torque oscillator 70b is controlled by the electric circuit 80b and applies a high-frequency magnetic field to the magnetic disk 12 when a current is supplied.

  Also in the third embodiment configured as described above, it is possible to provide a magnetic head capable of increasing the linear recording density by improving the write margin, and a disk device including the same. Further, the spin injection layers of the spin torque oscillators 70a and 70b can be made common, and the structure can be simplified. Since the spin torque oscillators 70a and 70b are arranged in the track direction, during the recording operation, the magnetic head can be sequentially written to the magnetic dots 50 and 51 while being positioned on the common track. Positioning control can be simplified.

  15 and 16 show the recording layer 23 of the magnetic disk 12 in the HDD according to the fourth embodiment. According to the present embodiment, the magnetic dots 50 and 51 formed of ferromagnetic materials having different magnetic resonance frequencies are provided alternately along the circumferential direction and the rotation direction B of the magnetic disk 12. . In the present embodiment, the magnetic dots 50 are provided in a line at a predetermined interval in the radial direction of the magnetic disk 12, and the magnetic dots 51 are arranged in a line at a predetermined interval in the radial direction of the magnetic disk 12. It is provided side by side.

  17 and 18 show the recording layer 23 of the magnetic disk 12 in the HDD according to the fifth embodiment. According to this embodiment, the magnetic dots 50 and 51 formed of ferromagnetic materials having different magnetic resonance frequencies are provided alternately in a zigzag pattern along the circumferential direction and the rotation direction B of the magnetic disk 12. It has been. That is, in the present embodiment, the magnetic dots 50 are provided in a line at a predetermined interval in the circumferential direction of the magnetic disk 12. The magnetic dots 51 are arranged in a line at a predetermined interval in the circumferential direction of the magnetic disk 12, and are arranged with a half pitch shift in the circumferential direction with respect to the adjacent magnetic dots 50.

  Even when the magnetic disk 12 configured as in the fourth and fifth embodiments is used, the same effects as those of the first embodiment can be obtained.

  The magnetic material layer in the recording layer of the magnetic disk in the HDD is not limited to the magnetic dot shape described above, and may be formed in a track shape extending continuously in the circumferential direction. 19, 20, and 21 show the recording layer 23 of the magnetic disk 12 in the HDD according to the sixth embodiment. According to the present embodiment, the magnetic disk 12 is configured as a so-called discrete disk, and has magnetic tracks 50 and 51 formed in a track shape by two types of ferromagnetic materials having different magnetic resonance frequencies. These magnetic tracks 50 and 51 are formed alternately and concentrically in the radial direction of the magnetic disk 12.

According to the HDD having the magnetic disk 12 configured as described above, it is possible to reduce the write error of adjacent tracks, widen the write margin in the radial direction, and improve the recording density.
In the fourth to sixth embodiments, other configurations of the HDD are the same as those of the first embodiment described above.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  For example, the material, shape, size, etc. of the elements constituting the head part can be changed as necessary. Further, in the magnetic disk device, the number of magnetic disks and magnetic heads can be increased as necessary, and various sizes of magnetic disks can be selected. The number of high-frequency oscillation elements, for example, spin torque oscillators, in the recording head is not limited to two and may be three or more. In this case, the ferromagnetic material forming the recording layer of the magnetic disk can also increase the write margin by using three or more types of magnetic material layers having different resonance frequencies. Side shields may be provided on both sides of the main pole in the track direction.

DESCRIPTION OF SYMBOLS 10 ... Housing, 11 ... Base, 12 ... Magnetic disk, 13 ... Spindle motor,
14 ... head actuator, 25 ... control circuit board, 27 ... arm,
30 ... Suspension, 37 ... Head IC, 42 ... Slider, 43 ... Disc facing surface,
44 ... head portion, 50, 51 ... magnetic dot, 54 ... reproducing head, 56 ... recording head,
65 ... Recording coil, 66, 84a, 84b ... Main magnetic pole, 68 ... Return magnetic pole,
70a, 70b ... spin torque oscillators, 72a, 72b ... oscillation layers,
74, 74a, 74b ... spin injection layer, 80, 80a, 80b ... electric circuit

According to the embodiment, the magnetic head is opposed to the main pole that applies a recording magnetic field perpendicular to the recording layer of the recording medium, with a write gap on the trailing side of the main pole, and the magnetic flux from the main pole A return magnetic pole that forms a magnetic circuit together with the main magnetic pole, a coil that excites magnetic flux in the magnetic circuit formed by the main magnetic pole and the return magnetic pole, and the main magnetic pole between the main magnetic pole and the return magnetic pole, respectively A plurality of high-frequency oscillation elements that are provided in a line in the track direction and have a plurality of magnetic films having different magnetic resonance frequencies and apply a high-frequency magnetic field to the recording medium, respectively, and for energizing the high-frequency oscillation elements comprising an electric circuit, wherein the plurality of high frequency oscillator includes a first high frequency oscillator having an oscillation layer and the spin injection layer, the oscillation of the first high frequency oscillator It includes a different oscillation layer of magnetic resonance frequency, and a second high frequency oscillator having a common spin injection layer and the spin injection layer of the first high frequency oscillator.

Claims (15)

A main pole for applying a recording magnetic field perpendicular to the recording layer of the recording medium;
A return magnetic pole facing the trailing side of the main magnetic pole with a write gap, and forming a magnetic circuit with the main magnetic pole by refluxing the magnetic flux from the main magnetic pole,
A coil for exciting magnetic flux in a magnetic circuit formed by the main magnetic pole and the return magnetic pole;
A plurality of high-frequency oscillation elements each provided between the main magnetic pole and the return magnetic pole, having a plurality of magnetic films having different magnetic resonance frequencies, and applying a high-frequency magnetic field to the recording medium;
An electric circuit for energizing the high-frequency oscillation element;
A magnetic head comprising:   2. The magnetism according to claim 1, wherein the plurality of high-frequency oscillation elements include two or more high-frequency oscillation elements provided side by side in a track width direction of the main magnetic pole, and the magnetic resonance frequencies of the high-frequency oscillation elements are different from each other. head.   The main magnetic pole has a first main magnetic pole and a second main magnetic pole that are magnetically separated from each other in the track width direction, and the high-frequency oscillation element is provided between the first main magnetic pole and the return magnetic pole. The magnetic head according to claim 2, further comprising: a first high-frequency oscillation element; and a second high-frequency oscillation element provided between the second main magnetic pole and the return magnetic pole.   The electrical circuit supplies a current to the first main magnetic pole, the first high-frequency oscillation element, and the return magnetic pole, and supplies a current to the second main magnetic pole, the second high-frequency oscillation element, and the return magnetic pole. The magnetic head according to claim 3, further comprising:   The magnetic head according to claim 1, wherein the plurality of high-frequency oscillation elements are arranged in a line in a track direction of the main magnetic pole.   The plurality of high frequency oscillation elements include a first high frequency oscillation element having an oscillation layer and a spin injection layer, an oscillation layer having a magnetic resonance frequency different from that of the first high frequency oscillation element, and a spin injection of the first high frequency oscillation element. The magnetic head according to claim 5, further comprising: a second high-frequency oscillation element having a spin injection layer shared with the layer. A disk-shaped perpendicular magnetic recording medium comprising a recording layer having a plurality of magnetic layers separated from each other and formed of two or more types of ferromagnetic materials having different magnetic resonance frequencies;
A mechanism for rotating the recording medium;
A magnetic head having a slider having a facing surface facing the surface of the recording medium, and a head portion provided at one end of the slider for performing information processing on the recording medium;
With
The head portion is
A main magnetic pole for applying a recording magnetic field perpendicular to the recording layer;
A return magnetic pole facing the trailing side of the main magnetic pole with a write gap, and forming a magnetic circuit with the main magnetic pole by refluxing the magnetic flux from the main magnetic pole,
A coil for exciting magnetic flux in a magnetic circuit formed by the main magnetic pole and the return magnetic pole;
A plurality of high-frequency oscillation elements each provided between the main magnetic pole and the return magnetic pole, each having a magnetic film having a different magnetic resonance frequency, and applying a high-frequency magnetic field to the recording medium;
An electric circuit for energizing the high-frequency oscillation element;
A disk device comprising:   8. The disk device according to claim 7, wherein the magnetic layer is formed on magnetic dots that are magnetically separated from each other, and magnetic dots having different magnetic resonance frequencies are alternately arranged in the rotation direction of the recording medium.   The disk device according to claim 8, wherein the magnetic dots having different magnetic resonance frequencies are alternately arranged in a radial direction of the recording medium.   The disk apparatus according to claim 8, wherein magnetic dots having the same magnetic resonance frequency are arranged in a radial direction of the recording medium.   8. The disk device according to claim 7, wherein the magnetic layer is formed into a plurality of magnetic tracks that are magnetically separated from each other, and magnetic tracks having different magnetic resonance frequencies are alternately arranged in the radial direction of the recording medium. .   The plurality of high-frequency oscillation elements include two or more high-frequency oscillation elements provided side by side in the track width direction of the main magnetic pole, and the magnetic resonance frequencies of the high-frequency oscillation elements are different from each other, and the plurality of magnetic layers The disk device according to claim 7, which corresponds to a magnetic resonance frequency of   The main magnetic pole has a first main magnetic pole and a second main magnetic pole that are magnetically separated from each other in the track width direction, and the high-frequency oscillation element is provided between the first main magnetic pole and the return magnetic pole. The disk device according to claim 12, further comprising: a first high-frequency oscillation element; and a second high-frequency oscillation element provided between the second main magnetic pole and the return magnetic pole.   The electrical circuit supplies a current to the first main magnetic pole, the first high-frequency oscillation element, and the return magnetic pole, and supplies a current to the second main magnetic pole, the second high-frequency oscillation element, and the return magnetic pole. The disk device according to claim 13, further comprising:   The disk device according to claim 7, wherein the plurality of high-frequency oscillation elements are provided in a line in a track direction of the main magnetic pole.

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