JP2010182347A - Thin-film magnetic head with microwave band magnetic drive function, and magnetic recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-film magnetic head with a microwave band magnetic drive function, for efficiently applying a microwave to a magnetic recording medium, and to provide a magnetic recording and reproducing device. <P>SOLUTION: The thin-film magnetic head is provided with a write magnetic field generation means; a line conductor in a planar microwave radiator which is provided independently from the write magnetic field generation means and which radiates the magnetic field for microwave band resonance having a ferromagnetic resonance frequency of the magnetic recording medium or a frequency in the vicinity thereof when a microwave excitation current is applied; and magnetic poles provided separately for the line conductor in a direction vertical to the track width direction and in parallel to ABS. The microwave radiator is an inverted microstrip waveguide. The line conductor and a surface facing at least one of magnetic electrodes are in parallel each other. A distance D between the facing surfaces is larger than the sum (R+S) of circular arc length R from a position being the remotest end from ABS in facing surfaces to a magnetic recording medium direction and a distance S between the line conductor and the magnetic recording medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thin-film magnetic head with a microwave band magnetic drive function and a magnetic recording / reproducing apparatus for writing a data signal on a magnetic recording medium having a large coercive force to stabilize magnetization.

  With the increase in recording density of magnetic recording / reproducing devices represented by magnetic disk drive devices, bit cells of digital information recorded on magnetic recording media have been miniaturized, and as a result, read head elements of thin film magnetic heads due to so-called thermal fluctuations. The signal detected from the signal fluctuates and the S / N (signal to noise ratio) deteriorates. In the worst case, the signal may disappear.

  Therefore, in a magnetic recording medium using a perpendicular magnetic recording method that has been put into practical use in recent years, it is effective to increase the perpendicular magnetic anisotropy energy Ku of the recording film constituting the recording medium. On the other hand, the thermal stability index S corresponding to the thermal fluctuation is expressed by the following formula, and is usually said to be 50 or more.

S = Ku · V / k _B · T (1)
Here, Ku: perpendicular magnetic anisotropy energy, V: volume of crystal grains constituting the recording film, k _B : Boltzmann constant, and T: absolute temperature.

  According to the so-called Stoner-Wolfart model, the anisotropic magnetic field Hk and the coercive force Hc of the recording film are expressed by the following equations. ).

H = Hc = 2Ku / Ms (2)
Where Ms is the saturation magnetization of the recording film.

  In order to perform the magnetization reversal of the recording film corresponding to the intended data series, the write head element of the thin film magnetic head must apply a steep recording magnetic field that is at most about the anisotropic magnetic field Hk of the recording film. . In a magnetic disk drive (HDD) apparatus put into practical use using a perpendicular magnetic recording system, a write head element using a so-called single magnetic pole is used, and recording is performed from the surface of the air bearing surface (ABS) to the recording film in the vertical direction. A magnetic field is applied. Since the intensity of the perpendicular recording magnetic field is proportional to the saturation magnetic flux density Bs of the soft magnetic material forming the single magnetic pole, a material having the highest saturation magnetic flux density Bs has been developed and put to practical use. However, the saturation magnetic flux density Bs has a practical upper limit of Bs = 2.4T (Tesla) from the so-called Slater-Pauling curve, and is approaching the practical limit at present. In addition, the thickness and width of the current single magnetic pole are about 100 to 200 nm. However, when the recording density is increased, it is necessary to further reduce the thickness and width, and accordingly, the generated vertical magnetic field is further reduced. End up.

As described above, it is difficult to perform high-density recording due to the limitation of the recording capability of the write head element. Therefore, so-called heat-assisted magnetic recording (TAMR: Thermal) is performed in which a recording film is irradiated with a laser beam or the like to raise the temperature, and a signal is recorded in a state where the coercive force Hc of the recording film is lowered.
An Assisted Magnetic Recording method has been proposed.

  For example, in Patent Document 1, an electron emission source is used to irradiate a magnetic recording medium with electrons, the recording portion of the magnetic recording medium is heated and heated to lower the coercive force, and then the magnetic recording head uses a magnetic recording head. Information can be recorded. In Patent Document 2, a scatterer constituting a near-field optical probe provided in contact with the main magnetic pole of a perpendicular magnetic recording head is irradiated with laser light using a semiconductor laser element provided in the head. A technique for generating near-field light and applying the near-field light to a magnetic recording medium to increase the temperature of the magnetic recording medium is disclosed.

  However, these heat-assisted magnetic recording systems also have problems due to various technical difficulties.

  For example, 1) a thin film magnetic head on which a magnetic element and an optical element are mounted is essential, but this is extremely complicated in structure and expensive to manufacture. 2) Temperature characteristic change of coercive force Hc It is necessary to develop a large recording film. 3) Thermal demagnetization in the recording process has serious problems such as adjacent track erasure and recording state instability.

On the other hand, in recent years, spin behavior in electron conduction (Spin) has been aimed at increasing the sensitivity of giant magnetoresistive (GMR) read head elements and tunnel magnetoresistive (TMR) read head elements.
Research on Transfer) has been actively conducted, and this is applied to the magnetization reversal of the recording film of the magnetic recording medium, and research has been started to reduce the perpendicular magnetic field necessary for the magnetization reversal (Non-Patent Literature). 1, Patent Documents 3 and 4).

  This technology applies a high-frequency alternating magnetic field in the in-plane direction of the magnetic recording medium simultaneously with the perpendicular recording magnetic field, and the number of alternating magnetic fields applied in the in-plane direction corresponds to the ferromagnetic resonance frequency of the recording film. The microwave band has a very high frequency (several GHz to 10 GHz). An analysis result has been reported that the required reverse magnetic field in the vertical direction can be reduced to about 60% of the anisotropic magnetic field Hk of the recording film by simultaneously applying the in-plane alternating magnetic field and the perpendicular recording magnetic field. ing. If this technology is put to practical use, it is not necessary to use a TAMR system having a complicated structure, and further, it becomes possible to increase the anisotropic magnetic field Hk of the recording film, so that a great improvement in recording density is expected. .

  However, since the microwave magnetic field radiating means in the conventional microwave assisted magnetic recording system is a write coil wound around a magnetic material or a subcoil provided separately from the write coil, the frequency of the microwave to be applied Becomes higher, the portion radiates at that portion, and even if the supplied power is increased, the microwave magnetic field cannot be radiated in the direction of the recording medium. For this reason, when the frequency of the microwave becomes higher, it is extremely difficult to increase the anisotropic magnetic field Hk of the recording film.

JP 2001-250201 A JP 2004-158067 A JP 2007-299460 A JP 2008-159105 A

J. Zhu, “Recording Well Below Medium Coercivity Assisted by Localized Microwave Utilizing Spin Transfer”, Digest of MMM, 2005

  Therefore, the present applicant uses a method of using a waveguide having a planar structure such as a coplanar waveguide (CPW) or an inverted microstrip waveguide (I-MLIN) as a microwave magnetic field radiation means in the microwave assisted magnetic recording system. It has already been proposed (for example, Japanese Patent Application No. 2008-242400, filed on September 22, 2008).

According to this method, since the distance between the ground conductor (ground electrode) and the line conductor (signal electrode) is minimized, a strong high-frequency electric field or high-frequency magnetic field can be obtained. This is because Coulomb's law of charge distribution E = kQ / r ² (E is electric field, Q is electric charge, k is proportional constant, r is distance between electrodes), and electric field E is the square of distance r between electrodes. It takes advantage of becoming stronger in inverse proportion to That is, when the distance is minimized, a strong electric field and magnetic field are obtained in proportion to the square of the distance.

  FIG. 12 is a cross-sectional view showing the configuration when (A) CPW is used as the microwave magnetic field radiation means in the microwave assisted magnetic recording system and (B) I-MLIN is used. FIGS. 6A and 6B both show a cross section perpendicular to the track width direction of the thin film magnetic head, and therefore the horizontal direction of the plane of the figure is the relative movement direction of the magnetic recording medium, and is perpendicular to the plane of the figure. The direction is the track width direction.

In FIG. 4A, reference numeral 120 denotes a CPW line conductor, and 121 and 122 are main magnetic pole layers and auxiliary magnetic pole layers of a write magnetic head element existing above and below (on both sides in FIG. 12A) in the lamination direction of the line conductors. 123 and 123 respectively indicate magnetic recording media. In this configuration, the magnetic recording medium 123 is not grounded, and the main magnetic pole layer 121 and the auxiliary magnetic pole layer 122 are grounded to constitute a CPW ground conductor. According to the CPW having such a configuration, when a microwave current is passed, the lines of electric force 124 fly to the ground conductors 121 and 122 existing above and below the line conductor 120 in the stacking direction. The electric lines of force do not fly directly, and the magnetic field 125 generated perpendicular to the electric lines of force 124 is naturally weakened. That is, the resonance magnetic field 125 in the longitudinal direction (in the plane of the magnetic recording medium surface or substantially in the in-plane direction and in the track direction), which is a direction perpendicular to the electric force lines 124 directed to the surface of the magnetic recording medium 123, is also weakened. End up. The resonance magnetic field 125 is a high-frequency magnetic field of the microwave band having a ferromagnetic resonance frequency F _R or frequency in the vicinity thereof of the magnetic recording layer of the magnetic recording medium 123, a magnetic recording this longitudinal resonance magnetic field during writing By applying it to the layer, it is impossible to reduce the coercive force of the magnetic recording layer and reduce the writing magnetic field strength in the perpendicular direction (perpendicular or substantially perpendicular to the surface of the magnetic recording layer) required for writing. .

In FIG. 12B, 130 is an I-MLIN line conductor, 131 and 132 are main poles of a write magnetic head element that exist above and below the line conductor 130 in the stacking direction (both sides in FIG. 12B). A layer and an auxiliary magnetic pole layer, 133 indicate magnetic recording media, respectively. In this case, the magnetic recording medium 133 is grounded and constitutes a ground conductor of I-MLIN. According to the I-MLIN having such a configuration, when a microwave current is passed, the electric lines of force 134 fly to the ground conductor below the line conductor 130, that is, the magnetic recording medium 133, but the line conductor 130 is laminated. Part of the lines of electric force fly to the main magnetic pole layer 131 and the auxiliary magnetic pole layer 132 that exist above and below the direction, so that not all energy reaches the magnetic recording medium 133. Actually, compared to the distance between the line conductor 130 of the microwave radiator and the magnetic recording medium 133 as the ground conductor, the main magnetic pole layer 131 existing above and below the line conductor 130 of the microwave radiator and When the distance to the auxiliary magnetic pole layer 132 is narrow, this influence is significant. This is because the electric lines of force fly the shortest distance. That is, since the grounded main magnetic pole layer 131 and auxiliary magnetic pole layer 132 are used as the return of electric lines of force, most electric lines of force fly to these metal electrodes, and the spread of the magnetic field 135 also extends in the lateral direction. However, it does not concentrate below the magnetic recording medium. That is, the resonance magnetic field 135 in the longitudinal direction (in the plane of the magnetic recording medium surface or substantially in the in-plane direction and in the track direction), which is a direction perpendicular to the electric force lines 134 directed to the surface of the magnetic recording medium 133, is weakened. End up. The resonance magnetic field 135 is a high-frequency magnetic field of the microwave band having a ferromagnetic resonance frequency F _R or frequency in the vicinity thereof of the magnetic recording layer of the magnetic recording medium 133, a magnetic recording this longitudinal resonance magnetic field during writing By applying it to the layer, it is impossible to reduce the coercive force of the magnetic recording layer and reduce the writing magnetic field strength in the perpendicular direction (perpendicular or substantially perpendicular to the surface of the magnetic recording layer) required for writing. .

  Accordingly, an object of the present invention is to provide a thin-film magnetic head with a microwave band magnetic drive function and a magnetic recording / reproducing apparatus capable of efficiently applying a microwave to a magnetic recording medium.

According to the present invention, a thin-film magnetic head with a microwave band magnetic drive function is provided independently of a write magnetic field generating means for generating a write magnetic field to a magnetic recording medium in response to a write signal, and the write magnetic field generating means. is and a line conductor in ferromagnetic resonance frequency F _R or microwave radiator of planar structure shaped to radiate microwave band resonance magnetic field having a frequency near the magnetic recording medium by passing microwave excitation current And at least one magnetic pole provided perpendicular to the track width direction with respect to the line conductor and spaced apart in a direction parallel to the ABS. The microwave radiator is an inverted microstrip waveguide including a line conductor and a ground conductor constituted by a magnetic recording medium. The opposing surfaces of the line conductor and the at least one magnetic pole are parallel to each other, and the distance D between these opposing surfaces is an arc length R from the position farthest from the ABS to the magnetic recording medium direction on the opposing surface of the line conductor. And the sum (R + S) of the distance S between the line conductor and the magnetic recording medium.

The distance D between the opposing surfaces of the line conductor and the at least one magnetic pole is set such that the arc length R from the position farthest from the ABS to the magnetic recording medium direction on the opposing surface of the line conductor and the distance between the line conductor and the magnetic recording medium Therefore, almost all of the electric lines of force generated from the opposing surface of the line conductor enter the magnetic recording medium, and microwaves are applied to the magnetic recording medium very efficiently. be able to. In addition, since the return of the electric lines of force from the line conductor returns directly to the magnetic recording medium that is the ground conductor because it is a microstrip line, all of the microwave power converted into an electric field / magnetic field is all magnetic recording medium. Can be applied. Moreover, since it is an inverted microstrip waveguide, the lines of electric force from the line conductor do not travel in the direction of the back side of the substrate, but are all applied to the magnetic recording medium that is the ground conductor. In that case, since only air exists between the line conductor and the magnetic recording medium as the ground conductor, the dielectric loss is very small as compared with the case where the dielectric material is present. Of course, according to the present invention, it is possible to write a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating. As described above, at the time of writing, electric lines of force are applied toward the surface of the magnetic recording medium, and the longitudinal direction (in-plane or substantially in-plane direction of the surface of the magnetic recording medium) is a direction perpendicular to the electric lines of force. to generate a high-frequency magnetic field) of a microwave band having a ferromagnetic resonance frequency F _R or frequency in the vicinity thereof of the magnetic recording layer of the resonance magnetic field (magnetic recording medium in the track direction) Te, the resonance magnetic field to the magnetic recording layer By applying it, the magnetization of the medium is made unstable, the coercive force of the magnetic recording layer is lowered, and the writing magnetic field strength in the perpendicular direction (direction perpendicular to or substantially perpendicular to the surface of the magnetic recording layer) required for writing is increased. It can be greatly reduced.

  The terms used in this specification are defined as follows. In the layer structure of the component formed on the element forming surface of the substrate, the component on the substrate side of the reference layer is assumed to be “below” or “below” the reference layer, and the reference layer It is assumed that the component on the side in which the layers are stacked is “above” or “above” the reference layer. For example, “the lower magnetic pole layer is on the insulating layer” means that the lower magnetic pole layer is located on the side of the direction of lamination with respect to the insulating layer.

  The arc length R is preferably R = πA / 2, where A is the length in the direction away from the ABS on the opposing surface of the line conductor.

  A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means, and the microwave It is also preferable that the line conductor of the radiator is disposed between the main magnetic pole and the auxiliary magnetic pole, and at least one magnetic pole is the main magnetic pole and the auxiliary magnetic pole. In the perpendicular magnetic recording type write head element, the strongest write magnetic field is generated at the edge on the auxiliary magnetic pole side at the tip of the main pole, so by arranging the line conductor of the microwave radiator at this position, The resonance magnetic field can be applied to the magnetic recording medium more effectively. In this case, it is more preferable that the distance between the line conductor and the main magnetic pole and the distance between the line conductor and the auxiliary magnetic pole are both larger than the sum of the arc length R and the distance S (R + S).

  Further, it comprises a perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is this coil means, It is also preferable that the line conductor of the microwave radiator is disposed on the side opposite to the auxiliary magnetic pole with respect to the main magnetic pole, and at least one magnetic pole is the auxiliary magnetic pole. In this case, the distance between the line conductor and the auxiliary magnetic pole is more preferably larger than the sum of the arc length R and the distance S (R + S).

  It is also preferable that the cross section in the direction perpendicular to the track width direction of the line conductor has a rectangular shape.

According to the present invention, the magnetic recording medium having the magnetic recording layer, the write magnetic field generating means for generating the write magnetic field to the magnetic recording medium in response to the write signal, and the write magnetic field generating means are provided independently. cage microwave ferromagnetic resonance frequency F _R or line conductor of the microwave radiator of planar structure shaped to radiate microwave band resonance magnetic field having a frequency near the magnetic recording medium by passing the excitation current, and line conductor And a ground having a microwave radiator composed of a line conductor and a magnetic recording medium, and having at least one magnetic pole provided perpendicular to the track width direction and spaced apart in a direction parallel to the ABS Inverted microstrip waveguide having a conductor, opposing surfaces of the line conductor and at least one magnetic pole are parallel to each other, and the distance between the opposing surfaces is Thin film magnetism in which the distance D is greater than the sum (R + S) of the arc length R in the direction of the magnetic recording medium from the position farthest from the ABS on the opposing surface of the line conductor and the distance S between the line conductor and the magnetic recording medium Magnetic recording / reproduction comprising a head, a write signal supply means for generating a write signal and applying it to a write magnetic field generating means, and a microwave excitation current supply means for generating a microwave excitation current and applying it to a microwave radiator An apparatus is provided.

  The distance D between the opposing surfaces of the line conductor and the at least one magnetic pole is set such that the arc length R from the position farthest from the ABS to the magnetic recording medium direction on the opposing surface of the line conductor and the distance between the line conductor and the magnetic recording medium Therefore, almost all of the electric lines of force generated from the opposing surface of the line conductor enter the magnetic recording medium, and microwaves are applied to the magnetic recording medium very efficiently. be able to. In addition, since the return of the electric lines of force from the line conductor returns directly to the magnetic recording medium that is the ground conductor because it is a microstrip line, all of the microwave power converted into an electric field / magnetic field is all magnetic recording medium. Can be applied. Moreover, since it is an inverted microstrip waveguide, the lines of electric force from the line conductor do not travel in the direction of the back side of the substrate, but are all applied to the magnetic recording medium that is the ground conductor. In that case, since only air exists between the line conductor and the magnetic recording medium as the ground conductor, the dielectric loss is very small as compared with the case where the dielectric material is present. Of course, according to the present invention, it is possible to write a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating.

  The arc length R is preferably R = πA / 2, where A is the length of the line conductor in the direction away from the ABS.

  A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means, and the microwave It is also preferable that the line conductor of the radiator is disposed between the main magnetic pole and the auxiliary magnetic pole, and at least one magnetic pole is the main magnetic pole and the auxiliary magnetic pole. In the perpendicular magnetic recording type write head element, the strongest write magnetic field is generated at the edge on the auxiliary magnetic pole side at the tip of the main pole, so by arranging the line conductor of the microwave radiator at this position, The resonance magnetic field can be applied to the magnetic recording medium more effectively. In this case, it is more preferable that the distance between the line conductor and the main magnetic pole and the distance between the line conductor and the auxiliary magnetic pole are both larger than the sum of the arc length R and the distance S (R + S).

  Further, it comprises a perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is this coil means, It is also preferable that the line conductor of the microwave radiator is disposed on the side opposite to the auxiliary magnetic pole with respect to the main magnetic pole, and at least one magnetic pole is the auxiliary magnetic pole. In this case, the distance between the line conductor and the auxiliary magnetic pole is more preferably larger than the sum of the arc length R and the distance S (R + S).

  It is also preferable that the cross section in the direction perpendicular to the track width direction of the line conductor has a rectangular shape.

  One output terminal of the microwave excitation current supply means is connected to the line conductor of the microwave radiator, and the other output terminal of the microwave excitation current supply means is connected to the ground conductor constituted by the magnetic recording medium via a resistor. It is more preferable that they are connected.

  One end of the line conductor of the microwave radiator is grounded or terminated with a resistor equivalent to the characteristic impedance value of the microwave radiator, and the other end of the line conductor is connected to the microwave excitation current supply means. It is also preferable.

  It is also preferable to further include a DC excitation current supply circuit that generates a DC excitation current and applies it to the microwave radiator.

  At the position of the magnetic recording layer of the magnetic recording medium, the writing magnetic field has a direction perpendicular or substantially perpendicular to the surface of the magnetic recording layer, and the resonance magnetic field is in the direction of the surface of the magnetic recording layer. It is also preferable to set so as to have

  According to the present invention, microwaves can be more efficiently applied to a magnetic recording medium. Of course, according to the present invention, it is possible to write a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating.

1 is a perspective view schematically showing a configuration of a main part in an embodiment of a magnetic recording / reproducing apparatus according to the present invention. It is sectional drawing of the part of HGA in the magnetic recording / reproducing apparatus of FIG. FIG. 2 is a perspective view schematically showing an entire thin film magnetic head in the embodiment of FIG. 1. FIG. 4 is a schematic cross-sectional view taken along line AA of FIG. 3 while schematically showing the whole thin film magnetic head in the embodiment of FIG. 1. It is sectional drawing which shows schematically the structure which looked at the thin film magnetic head in embodiment of FIG. 1 from the ABS side. It is the figure which looked at the structure of a part of thin film magnetic head in embodiment of FIG. 1 from the upper surface with respect to the board | substrate. It is a figure which illustrates schematically the structure of the inverted microstrip waveguide in embodiment of FIG. It is a figure explaining the relationship between the dimension of the line conductor of the microwave radiator in this embodiment, and the distance between a line conductor, a main magnetic pole layer, and an auxiliary | assistant magnetic pole layer. It is a graph which shows the relationship between the distance D or D 'between a line conductor, a main magnetic pole layer, or an auxiliary | assistant magnetic pole layer, and a magnetic field intensity. FIG. 2 is a cross-sectional view illustrating the principle of the magnetic recording method according to the present invention and showing the head model of the embodiment of FIG. 1. FIG. 2 is a block diagram schematically showing an electrical configuration of the magnetic disk drive device in the embodiment of FIG. 1. It is sectional drawing which shows a structure at the time of using (B) I-MLIN when (A) CPW is used as a microwave magnetic field radiation | emission means in the conventional microwave assisted magnetic recording system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same constituent elements are denoted by the same reference numerals. In addition, the dimensional ratios in the components in the drawings and between the components are arbitrary for easy viewing of the drawings.

  FIG. 1 is a perspective view schematically showing a configuration of a main part in an embodiment of a magnetic recording / reproducing apparatus according to the present invention. FIG. 2 is a cross-sectional view of a head gimbal assembly (HGA) portion in the magnetic recording / reproducing apparatus of FIG. FIG.

  FIG. 1 shows a magnetic disk drive device as a magnetic recording / reproducing device. In FIG. 1, reference numeral 10 denotes a plurality of magnetic disks rotated around a rotation axis 11 a by a spindle motor 11, and 12 denotes a magnetic disk 10. An HGA 14 for appropriately making the thin film magnetic head (slider) 13 for writing and reading data signals to face the surface of each magnetic disk 10 positions the magnetic head slider 13 on a track of the magnetic disk 10. An assembly carriage device for each is shown.

  The assembly carriage device 14 mainly includes a carriage 16 that can be angularly swung about a pivot bearing shaft 15 and a voice coil motor (VCM) 17 that drives the carriage 16 to be swung angularly. A base of a plurality of drive arms 18 stacked in the direction of the pivot bearing shaft 15 is attached to the carriage 16, and the HGA 12 is fixed to the tip of each drive arm 18. A single magnetic disk 10, a single drive arm 18, and a single HGA 12 may be provided in the magnetic recording / reproducing apparatus.

  The magnetic disk 10 is grounded via a spindle motor 11 and its rotating shaft 11a (see FIG. 11).

  In FIG. 1, reference numeral 19 denotes a recording / reproducing and resonance control circuit for controlling the write and read operations of the thin-film magnetic head 13 and controlling the microwave excitation current for ferromagnetic resonance described later.

  As shown in FIG. 2, the HGA 12 has a thin film magnetic head 13, a load beam 20 and a flexure 21 made of a metal conductive material for supporting the thin film magnetic head 13, and a microwave excitation current and a DC excitation current. And an excitation current wiring member 22 which is a transmission line. Although not shown, the HGA 12 has a head element for flowing a write signal applied to the write head element of the thin film magnetic head 13 and for taking out a read output voltage by applying a constant current to the read head element. Wiring members are also provided.

  The thin film magnetic head 13 is attached to one end of an elastic flexure 21. The flexure 21 and the load beam 20 to which the other end is attached constitute a suspension for supporting the thin film magnetic head 13.

  The excitation current wiring member 22 is configured by a strip line having a ground conductor on the upper and lower portions of the entire length. That is, as shown in FIG. 2, copper (Cu) is interposed between the load beam 20 constituting the lower ground conductor and the upper ground conductor 22a via dielectric layers 22b and 22c made of a dielectric material such as polyimide, for example. Thus, the conductor line 22d is sandwiched. As the exciting current wiring member 22, one strip line is formed in parallel with the load beam surface (when the microwave circuit has an unbalanced structure). In this embodiment, the tip of the strip line on the magnetic head side is connected to the terminal electrode by wire bonding using the wire 23. On the other hand, although not shown in the drawing, the wiring members for the write head element and the read head element are formed from ordinary read conductors, and the tips of the wiring head elements are terminals of the write head element and the read head element by wire bonding in this embodiment. Connected to the electrode. You may comprise so that a wiring member and a terminal electrode may be connected by ball bonding, without using wire bonding.

  FIG. 3 is a perspective view schematically showing the entire thin film magnetic head 13 in the present embodiment.

  As shown in the figure, the thin film magnetic head 13 corresponds to a slider substrate 30 having an ABS 30a processed so as to obtain an appropriate flying height, and one side surface when the ABS 30a is a bottom surface. The magnetic head element 31 provided on the vertical element formation surface 30 b, the protection part 32 provided on the element formation surface 30 b so as to cover the magnetic head element 31, and the five exposed from the layer surface of the protection part 32 Terminal electrodes 33, 34, 35, 36 and 37 are provided.

  Here, the magnetic head element 31 mainly includes a magnetoresistive (MR) read head element 31a for reading a data signal from the magnetic disk and an inductive write head element 31b for writing the data signal to the magnetic disk. The terminal electrodes 33 and 34 are electrically connected to the MR read head element 31a, the terminal electrodes 35 and 36 are electrically connected to the inductive write head element 31b, and the terminal electrode 37 is described later. It is electrically connected to one end of the line conductor 38 (FIG. 4) of the inverted microstrip waveguide (I-MLIN). The other end of the line conductor 38 is grounded (in the case of an unbalanced structure).

  The terminal electrodes 33, 34, 35, 36 and 37 are not limited to the positions shown in FIG. 3, and may be provided in any arrangement on any position on the element formation surface 30b. Further, for example, it may be provided on the slider end surface 30c on the surface opposite to the ABS 30a. Furthermore, when a heater for adjusting the flying height is provided, a terminal electrode electrically connected to the heater is provided.

  In the MR read head element 31a and the inductive write head element 31b, one end of each element reaches the slider end face 30d on the surface on the ABS 30a side. Here, the slider end surface 30 d is a surface other than the ABS 30 a of the medium facing surface facing the magnetic disk of the thin film magnetic head 13, and is a surface mainly composed of the end surface of the protection unit 32. When one end of the MR read head element 31a and the inductive write head element 31b is opposed to the magnetic disk, the data signal is read by sensing the signal magnetic field and the data signal is written by applying the signal magnetic field. Note that an extremely thin coating such as diamond-like carbon (DLC) may be applied to one end of each element reaching the slider end face 30d and the vicinity thereof for protection.

  4 schematically shows the entire thin film magnetic head 13 in the present embodiment, and is a cross-sectional view taken along line AA in FIG. 3. FIG. 5 shows a configuration of the thin film magnetic head 13 in the present embodiment as viewed from the ABS side. FIG. 6 is a schematic cross-sectional view, and FIG. 6 is a diagram of a partial configuration of the thin film magnetic head 13 according to the present embodiment as viewed from above with respect to the substrate.

4 and 5, reference numeral 30 denotes a slider substrate made of AlTiC (Al ₂ O ₃ —TiC) or the like, and has an ABS 30a facing the surface of the magnetic disk. On the element forming surface 30b of the slider substrate 30, an MR read head element 31a, an inductive write head element 31b, an I-MLIN line conductor 38 described later formed in the inductive write head element 31b, and these The protection part 32 which protects an element is mainly formed.

MR read head element 31a includes a MR multilayer 31a _1, and a lower shield layer 31a ₂ and the upper shield layer 31a ₃ which are arranged at positions sandwiching the laminate. The MR multilayer 31a ₁ is composed of an in-plane conduction type (CIP) GMR multilayer film, a vertical conduction type (CPP) GMR multilayer film, or a TMR multilayer film, and senses a signal magnetic field from a magnetic disk with very high sensitivity. To do. The lower shield layer 31a ₂ and the upper shield layer 31a ₃ prevent the MR multilayer 31a _{1 from} being affected by an external magnetic field that causes noise.

When the MR laminate 31a ₁ is formed of a CIP-GMR multilayer film, an insulating lower shield gap layer and upper shield gap are provided between the lower shield layer 31a ₂ and the upper shield layer 31a ₃ and the MR laminate 31a _1. Each layer is provided. Further, an MR lead conductor layer for supplying a sense current to the MR multilayer 31a ₁ and taking out a reproduction output is formed. On the other hand, when the MR multilayer 31a ₁ is made of a CPP-GMR multilayer film or a TMR multilayer film, the lower shield layer 31a ₂ and the upper shield layer 31a ₃ also function as upper and lower electrode layers, respectively. In this case, the lower shield gap layer, the upper shield gap layer, and the MR lead conductor layer are unnecessary. Although not shown, on both sides of the track width direction of the MR stack 31a _1, the insulating layer or bias insulating layer for the magnetic domain structure is applied to a vertical bias magnetic field to stabilize and the hard bias layer is formed The

For example, when the MR laminate 31a ₁ includes a TMR multilayer film, the MR laminate 31a ₁ is made of iridium manganese (IrMn), platinum manganese (PtMn), nickel manganese (NiMn), ruthenium rhodium manganese (RuRhMn), or the like. An antiferromagnetic layer and, for example, two ferromagnetic films such as cobalt iron (CoFe) are composed of a three-layer film sandwiching a nonmagnetic metal film such as ruthenium (Ru). The fixed magnetization pinned layer and a metal film having a thickness of about 0.5 to 1 nm made of, for example, aluminum (Al), aluminum copper (AlCu), magnesium (Mg), or the like, are added by oxygen introduced into the vacuum apparatus or A tunnel barrier layer made of a nonmagnetic dielectric film oxidized by natural oxidation and a thickness of 1 nm made of, for example, CoFe Exchange with a magnetization fixed layer via a tunnel barrier layer, which consists of a ferromagnetic film with a thickness of about 3 to 4 nm and a ferromagnetic film made of nickel iron (NiFe) or the like. A magnetization free layer that forms a coupling has a structure in which the layers are sequentially stacked.

Further, the lower shield layer 31a ₂ and the upper shield layer 31a ₃ are formed of, for example, NiFe (permalloy or the like) having a thickness of about 0.1 to 3 μm and cobalt iron nickel formed by using a pattern plating method including a frame plating method. (CoFeNi), CoFe, iron nitride (FeN), or iron zirconium nitride (FeZrN) film.

Inductive write head element 31b is for perpendicular magnetic recording, from the end of the write time of the own ABS30a (slider end surface 30d) side of the data signal and the main magnetic pole layer 31b ₁ as the main magnetic poles generated in the write magnetic field, the trailing A gap layer 31b ₂ , a write coil 31b ₃ having a spiral shape and passing between the main magnetic pole layer and the auxiliary magnetic pole layer for at least one turn, and a write coil insulating layer 31b ₄ Auxiliary magnetic pole layer 31b ₅ as an auxiliary magnetic pole in which a portion separated from the end portion on the ABS 30a (slider end surface 30d) side is magnetically connected to main magnetic pole layer 31b _1; and auxiliary shield layer 31b ₆ as an auxiliary shield; , and a leading gap layer 31b _7.

The main magnetic pole layer 31b ₁ is a magnetic path for guiding the magnetic flux generated by applying the write current to the write coil 31b ₃ while converging it to the magnetic recording layer of the magnetic disk to be written. and a yoke layer _{31b 11} and the main magnetic pole main layer _{31b 12.} Here, the main magnetic pole layer 31b ₁ ABS30a the thickness direction length at the end of the (slider end surface 30d) side (thickness), decreases and corresponds to the layer thickness of the main magnetic pole main layer _{31b 12} only ing. As a result, when writing a data signal, a fine write magnetic field corresponding to a higher recording density can be generated from this end. The main magnetic pole yoke layer 31b ₁₁ and the main magnetic pole main layer 31b ₁₂ are formed by using, for example, a sputtering method, a pattern plating method including a frame plating method, etc., and have a thickness of about 0.5 to 3.5 μm, respectively. It is composed of a NiFe, CoFeNi, CoFe, FeN or FeZrN film having a thickness of about 0.1 to 1 μm.

Auxiliary pole layer 31b ₅ and the auxiliary shield layer 31b _6, respectively, are disposed on the trailing side and the leading side of the main magnetic pole layer 31b _1. Auxiliary pole layer 31b _5, as described above, ABS30a but spaced portions to the end portions of the (slider end surface 30d) side is the main magnetic pole layer 31b ₁ and magnetically coupled, the auxiliary shield layer 31b ₆ is not the main magnetic pole layer 31b ₁ and magnetically connected in this embodiment.

End of the slider end surface 30d side of the auxiliary magnetic pole layer 31b ₅ and the auxiliary shield layer 31b _6, respectively, the layer cross-section has a broad trailing shield section _{31b 51} and the leading shield section _{31b 61} than other portions. Trailing shield section _{31b 51} is opposed through the end portion and the trailing gap layer 31b ₂ of the slider end surface 30d side of the main magnetic pole layer 31b _1. Further, the leading shield section _{31b 61} is opposed through the end portion and the leading gap layer 31b ₂ of the slider end surface 30d side of the main magnetic pole layer 31b _1. By providing the trailing shield part 31b ₅₁ and the leading shield part 31b ₆₁ as described above, due to the shunt effect of the magnetic flux, between the trailing shield part 31b ₅₁ and the end of the main magnetic pole layer 31b ₁ and the leading shield part 31b. magnetic field gradient of the write field between the end portion and the end portion of the main magnetic pole layer 31b _{1 61} becomes steeper. As a result, the jitter of the signal output is reduced, and the error rate at the time of reading can be reduced.

The auxiliary magnetic pole layer 31b ₅ or the auxiliary shield layer 31b ₆ is appropriately processed, and a part of the auxiliary magnetic pole layer 31b ₅ or the auxiliary shield layer 31b ₆ is arranged near both sides of the main magnetic pole layer 31b _{1 in} the track width direction. Thus, it is possible to provide a so-called side shield. In this case, the shunt effect of magnetic flux is enhanced.

The length (thickness) of the trailing shield part 31b ₅₁ and the leading shield part 31b _{61 in} the layer thickness direction is set to about several tens to several hundreds times the thickness of the main magnetic pole layer 31b _{1 in} the same direction. It is preferable. In addition, the gap length of the trailing gap layer 31b ₂ is preferably about 10 to 100 nm, and more preferably about 20 to 50 nm. Further, the gap length of the leading gap layer 31b ₇ is preferably 0.1μm or more.

The auxiliary magnetic pole layer 31b ₅ and the auxiliary shield layer 31b ₆ are formed of, for example, a NiFe, CoFeNi, CoFe, FeN, or FeZrN film having a thickness of about 0.5 to 4 μm formed by using a pattern plating method including a frame plating method. It is composed of In addition, the trailing gap layer 31b ₂ or the leading gap layer 31b ₇ is formed by using, for example, alumina (Al ₂ O ₃ ) or silicon oxide (0.1 to ₃ μm thick) formed by sputtering, CVD, or the like. SiO ₂ ), aluminum nitride (AlN), DLC film, or the like.

As shown in FIG. 6, a write signal is passed through the write coil 31b ₃ via the lead conductor 31b ₃₁ , the via-hole conductors 31b ₃₂ , 31b _33, 31b _{34, and the} like. Write coil insulating layer 31b ₄ surrounds the write coil 31b _3, is provided in order to electrically insulate the write coil 31b ₃ from around the magnetic layer. The write coil 31b ₃ is made of, for example, a Cu film having a thickness of about 0.1 to 5 μm formed by using a frame plating method, a sputtering method, or the like. The lead conductor 31b _{31 and the} via-hole conductors 31b ₃₂ , 31b ₃₃ and 31b ₃₄ are also composed of, for example, a Cu film formed using a frame plating method, a sputtering method, or the like. The write coil insulation layer 31b ₄ are formed, for example, a photoresist or the like which is heat curing thickness of about 0.5~7μm which are formed by photolithography or the like.

As shown in FIGS. 4 to 6, in this embodiment, the I-MLIN is interposed between the main magnetic pole main layer 31 b ₁₂ of the main magnetic pole layer 31 b ₁ and the trailing shield part 31 b ₅₁ of the auxiliary magnetic pole layer 31 b ₅ . A line conductor 38 is formed. In the present embodiment, the length in the track width direction of the line conductor 38, is substantially equal to the length in the track width direction of the main magnetic pole main layer 31b ₁₂ of the main magnetic pole layer 31b _1. The line conductor 38, the microwave excitation current and a DC excitation current flows through the lead conductors 38a ₁ and 38a ₂ and the via hole conductors 31a ₃ and 31a _4. Line conductor 38, the lead conductors 38a ₁ and 38a ₂ and the via hole conductors 31a ₃ and 31a ₄ is composed of a Cu film or the like formed by using, for example, a sputtering method, or the like. One end of the line conductor 38 is grounded via a lead conductor and a via-hole conductor, or is terminated with a resistor (not shown) equivalent to the characteristic impedance value of I-MLIN, and the other end is the lead conductor. And an excitation current supply circuit 115 (FIG. 11) to be described later via a via-hole conductor.

  FIG. 7 is a diagram for explaining the configuration of the planar structure type microwave radiator in the present embodiment.

As shown in the figure, in the present embodiment, the line conductor 38 provided between the main magnetic pole layer 31b ₁ and the auxiliary magnetic pole layer 31b ₅ on the thin film magnetic head side and the magnetic disk 10 facing the thin film magnetic head 13 are used. An I-MLIN is constituted by the ground conductor. As is well known, I-MLIN (inverted microstrip waveguide) is a modification of MLIN (microstrip waveguide). That is, in MLIN, a line conductor is provided on one surface of a dielectric substrate and a ground conductor is provided on the other surface of the dielectric substrate, whereas in I-MLIN, one surface of a dielectric substrate is provided. The line conductor is provided on the other side, but nothing is provided on the other side, and the ground conductor is provided so as to face one side of the line conductor and the dielectric substrate via a gap. . The magnetic disk 10 as a whole is a conductor and is grounded via the spindle motor 11 and its rotating shaft 11a, and therefore operates as a ground conductor. In this case, the trailing gap layer 31b ₂ corresponds to the dielectric substrate. The distance between the main magnetic pole layer 31b ₁ and the auxiliary magnetic pole layer 31b ₅ is, for example, about 30 to 40 nm, because the gap between the surface of the line conductor 38 and the magnetic disk 10 of the thin-film magnetic head is, for example, 3nm approximately, present As in the embodiment, even if the line conductor 38 is provided between the main magnetic pole layer and the auxiliary magnetic pole layer, the I-MLIN can be configured in a microwave manner.

By causing a microwave excitation current to flow through the line conductor 38, electric lines of force are generated between the main magnetic pole layer 31 b ₁ and the trailing shield part 31 b ₅₁ toward the surface of the magnetic disk 10. A resonance magnetic field in the longitudinal direction (in the plane of the magnetic disk surface or substantially in the plane and in the track direction), which is a perpendicular direction, is radiated. The resonance magnetic field is a high frequency magnetic field of the microwave band having a ferromagnetic resonance frequency F _R or frequency in the vicinity thereof of the magnetic recording layer of the magnetic disk 10. By applying this longitudinal resonance magnetic field to the magnetic recording layer at the time of writing, the writing magnetic field strength in the vertical direction (direction perpendicular to or substantially perpendicular to the surface of the magnetic recording layer) required for writing is greatly reduced. be able to.

  When the resonance magnetic field is radiated only by the microwave in this way, a large high-frequency current is required. Therefore, a DC excitation current that radiates a static magnetic field of about 80% of the magnetic coercive force of the magnetic disk 10 is superimposed on the line conductor 38. Therefore, the microwave power to be applied can be reduced.

  FIG. 8 is a diagram for explaining the relationship between the dimension of the line conductor of the microwave radiator and the distance between the line conductor and the main magnetic pole layer and the auxiliary magnetic pole layer in the present embodiment, and a cross section perpendicular to the track width direction of the thin film magnetic head. Represents.

As can be seen from the figure, the I-MLIN line conductor 38 has a rectangular shape in this cross section, and is parallel to the main magnetic pole layer 31b ₁ and the auxiliary magnetic pole layer 31b ₅ formed in parallel to each other. It has a left end surface (opposite surface) and right end surfaces (opposite surfaces) 381 and 382. Here, the main left end surface of the magnetic layer 31b ₁ and the line conductor 38 (facing surface) 381 of the distance is D, the distance between the right end surface (facing surface) 382 of the auxiliary pole layer 31b ₅ and the line conductor 38 D ', The length of the left end face (opposing face) and the right end faces (opposing faces) 381 and 382 of the line conductor 38 in the direction away from the ABS is A, and the bottom face (opposing face) 383 of the line conductor 38 and the ground conductor of I-MLIN. Let S be the distance from the surface of the magnetic disk 10.

  As is well known in the microwave technical field, electric lines of force are radiated perpendicularly from the conductor surface, so that they are emitted from the left end face (opposing face) and right end face (opposing face) 381 and 382 of the line conductor 38. As shown in the figure, the generated electric lines of force 80 are radiated perpendicularly from the surface and travel in the direction of the magnetic disk 10 while drawing an arc.

If this distance D and D than the path length of the electric lines of force 80 'is larger, the electric lines of force emitted from the right and left end faces of the line conductor 38, most toward the main pole layer 31b ₁ and the auxiliary magnetic pole layer 31b ₅ direction Without going to the lower magnetic disk 10. For example, the path length of the electric lines of force 80 is maximized on the main magnetic pole layer side when the electric lines of force are radiated from the position 385 which is the farthest end from the ABS on the left end surface 381 of the line conductor 38. In this case, since the arc length R is a quarter circumference of the radius A, R = 2πA / 4 = πA / 2, and the path length is R + S. Therefore, if D> πA / 2 + S and D ′> πA / 2 + S, almost all electric lines of force generated from the left and right end surfaces (opposing surfaces) 381 and 382 of the line conductor 38 enter the magnetic disk 10. Microwaves can be applied to the magnetic disk 10 very efficiently. In addition, since it is MLIN, the return of the electric lines of force from the line conductor 38 directly returns to the magnetic disk 10 that is the ground conductor, and therefore all the microwave power converted into an electric field / magnetic field is transferred to the magnetic disk 10. Can be applied. Moreover, since it is an I-MLIN, almost no electric lines of force are radiated from the upper surface 384 of the line conductor 38, and even if radiated, they do not travel in the direction of the back side of the substrate, and all of them are in the direction of the magnetic disk 10 that is a ground conductor. To be applied. In addition, since there is only air between the line conductor 38 and the magnetic disk 10 that is the ground conductor, the dielectric loss is much smaller than when a dielectric material is present. Of course, according to the present invention, it is possible to write a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating.

  FIG. 9 is a graph showing the relationship between the distance D or D ′ between the line conductor and the main magnetic pole layer or the auxiliary magnetic pole layer and the magnetic field intensity on the magnetic disk surface. In the drawing, the horizontal axis represents the horizontal width of the line conductor 38 (in the cross section of FIG. 8), for example, 10 nm, and the vertical axis represents the relative value when the magnetic field strength at saturation is 0 dB.

  As can be seen from the figure, when the distance D or D ′ is 2 or more, for example, 20 nm or more, the magnetic field strength is saturated. This is considered to be because almost all electric lines of force that emerge from the left and right end faces of the line conductor 38 enter the magnetic disk 10.

  FIG. 10 is a sectional view for explaining the principle of the magnetic recording method using the magnetic field for ferromagnetic resonance according to the present invention and showing the head model of the above-described embodiment.

  First, the structure of the magnetic disk 10 will be described with reference to FIG. The magnetic disk 10 is for perpendicular magnetic recording. On the disk substrate 10a, a magnetic orientation layer 10b, a soft magnetic backing layer 10c that functions as a part of a magnetic flux loop circuit, an intermediate layer 10d, a magnetic recording layer 10e, It has a multilayer structure in which a conductive protective layer 10f is sequentially stacked, and all layers including the disk substrate 10a are formed of a conductive material.

  The magnetization orientation layer 10b stabilizes the magnetic domain structure of the soft magnetic backing layer 10c by giving magnetic anisotropy in the track width direction to the soft magnetic backing layer 10c, thereby suppressing spike noise in the reproduced output waveform. ing. The intermediate layer 10d serves as an underlayer for controlling the magnetization orientation and grain size of the magnetic recording layer 10e.

  Here, the disk substrate 10a is made of nickel phosphorus (NiP) -coated Al alloy, silicon (Si), or the like. The magnetization alignment layer 10b is made of PtMn or the like that is an antiferromagnetic material. The soft magnetic underlayer 10c is made of a cobalt (Co) amorphous alloy such as cobalt zirconium niobium (CoZrNb), an iron (Fe) alloy, soft magnetic ferrite, or the like, or a soft magnetic film / non-magnetic multilayer film. Etc. are formed. The intermediate layer 10d is made of a Ru alloy or the like that is a nonmagnetic material. Here, the intermediate layer 10d may be another non-magnetic metal or alloy, or a low-permeability alloy as long as the perpendicular magnetic anisotropy of the magnetic recording layer 10e can be controlled. The protective layer 10f is formed of a carbon (C) material or the like by a chemical vapor deposition (CVD) method or the like.

The magnetic recording layer 10e is formed of, for example, a cobalt chromium platinum (CoCrPt) -based alloy, CoCrPt—SiO ₂ , an iron platinum (FePt) -based alloy, or a CoPt / palladium (Pd) -based artificial lattice multilayer film. In the magnetic recording layer 10e, the perpendicular magnetic anisotropy energy is adjusted to, for example, 1 × 10 ⁶ erg / cc (0.1 J / m ³ ) or more in order to suppress thermal fluctuation of magnetization. Is preferred. In this case, the value of the coercive force of the magnetic recording layer 10e is, for example, about 5 kOe (400 kA / m) or more. Furthermore, the ferromagnetic resonance frequency F _R of the magnetic recording layer 10e, the shape of the magnetic particles constituting the magnetic recording layer 10e, size, is a unique value determined by the constituent elements or the like, and generally 1~15GHz about It has become. The ferromagnetic resonance frequency F _R is In some cases only one is present, as when a spin wave resonance occurs, there is a case where there are a plurality.

Next, the principle of the magnetic recording method according to the present invention will be described with reference to FIG. By passing a microwave excitation current through I-MLIN, electric lines of force are generated toward the surface of the magnetic disk 10, and the magnetic disk surface is in the in-plane or substantially in-plane direction perpendicular to the electric lines of force. Thus, the resonance magnetic field 100 is radiated in the track direction. The resonance magnetic field 100, because it is a high-frequency magnetic field of a microwave band having a frequency of ferromagnetic resonance frequency F _R or near the magnetic recording layer 10e of the magnetic disk 10, effectively the coercivity of the magnetic recording layer 10e As a result, the strength of the write magnetic field 101 in the vertical direction (direction perpendicular to or substantially perpendicular to the surface of the magnetic recording layer 10e) required for writing can be greatly reduced. That is, by reducing the coercive force, it becomes easier to reverse the magnetization, so that recording can be performed efficiently with a small recording magnetic field.

In fact, by applying the resonance magnetic field having a ferromagnetic resonance frequency F _R of the magnetic recording layer, for example, the vertical direction of the write magnetic field can reverse the magnetization of the magnetic recording layer 10e was reduced by about 40%, 60 % Can be achieved. That is, even if the coercive force of the magnetic recording layer 10e before applying the resonance magnetic field is about 5 kOe (400 kA / m), this coercive force can be obtained by applying the resonance magnetic field in the in-plane direction of the magnetic recording layer. Can be effectively reduced to about 2.4 kOe (192 kA / m).

The intensity of the resonance magnetic field is the anisotropy field of the magnetic recording layer as _{H K,} more preferably about 0.1H _K ~0.2H _K, its frequency, the material of the magnetic recording layer 10e Depending on the layer thickness and the like, it is preferably about 1 to 15 GHz.

  FIG. 11 is a block diagram schematically showing the electrical configuration of the magnetic disk drive apparatus according to this embodiment.

  In the figure, 11 is a spindle motor that rotates the magnetic disk 10, 110 is a motor driver that is a driver of the spindle motor 11, 111 is a VCM driver that is a driver of the VCM 17, and 112 is a motor driver 110 that is controlled by a computer 113. And a hard disk controller (HDC) for controlling the VCM driver 111, 114 is a read / write IC circuit including a head amplifier 114a and a read / write channel 114b of the thin film magnetic head 13, and 115 is an excitation current for supplying a microwave excitation current and a DC excitation current. A supply circuit 116 indicates a head element wiring member for flowing a write signal applied to the write head element and for applying a constant current to the read head element to extract a read output voltage. One output terminal of the excitation current supply circuit 115 is connected to the line conductor 38 of the thin film magnetic head 13 via the excitation current wiring member 22 and the like, and the other output terminal is grounded. The magnetic disk 10 is grounded via a spindle motor 11 or the like.

  The recording / reproducing and resonance control circuit 19 shown in FIG. 1 includes the above-described HDC 112, computer 113, read / write IC circuit 114, excitation current supply circuit 115, and the like.

  As described above, according to the present embodiment, the distance between the line conductor and the main magnetic pole layer or the auxiliary magnetic pole layer is set such that D> πA / 2 + S and D ′> πA / 2 + S, whereby the line conductor 38 is obtained. Almost all of the lines of electric force generated from the left and right end surfaces (opposing surfaces) 38a and 38b enter the magnetic disk 10. As a result, the microwave can be applied to the magnetic disk 10 very efficiently. Of course, according to the present embodiment, it is possible to write a data signal with high accuracy on a magnetic disk having a large coercive force without heating.

  In the present embodiment, in particular, since the microwave radiator is composed of I-MLIN, the ground conductor in which the return of the electric field lines from the central line conductor exists in the lateral direction as in the case of CPW. Without returning to the magnetic disk 10, the return of the electric field lines coming out of the line conductor 38 returns directly to the magnetic disk 10 which is the ground conductor disposed at the opposite position. All can be applied to the magnetic disk 10. Therefore, strong radiation can be applied to the magnetic disk 10 without generating a weak radiation portion in the center of the radiation electric field, that is, the radiation magnetic field. Furthermore, since the return of the lines of electric force is applied substantially perpendicularly rather than in parallel with the surface of the magnetic disk, the direction of the magnetic field is parallel (longitudinal direction) to the surface of the magnetic disk. The writing magnetic field strength in a direction perpendicular or substantially perpendicular to the surface of the magnetic recording layer can be greatly reduced. In addition, because of the I-MLIN, the electric lines of force from the line conductor 38 do not travel in the direction of the back side of the substrate, but are all applied to the magnetic disk 10 that is a ground conductor. In this case, since only air exists between the line conductor 38 and the magnetic disk 10 that is the ground conductor, the dielectric loss is very small as compared with the case where the dielectric material is present.

  In the write head element of the perpendicular magnetic recording structure as in the present embodiment, the strongest write magnetic field is generated at the edge near the auxiliary magnetic pole side at the tip of the main magnetic pole, so that the line conductor 38 is connected to the main magnetic pole layer and the auxiliary magnetic pole layer. Therefore, the magnetic field for microwave band resonance can be applied to the magnetic disk 10 more effectively.

  Thus, it is understood that data signals can be written with high accuracy on a magnetic disk having a large coercive force without using so-called thermal assist (heating). Furthermore, such a magnetic recording method can be realized without using a special element that imposes a heavy burden such as an electron emission source and a laser light source, and the size and cost can be reduced.

  As a modification of this embodiment, the line conductor may be disposed on the opposite side of the auxiliary magnetic pole with respect to the main magnetic pole. However, in this case, since the position of the line conductor is shifted from the position where the strongest write magnetic field is generated, the effect of applying the magnetic field for microwave band resonance is somewhat lower than in the case of the above-described embodiment.

  Although the configuration of the thin film magnetic head 13 has been described in detail above, the thin film magnetic head of the present invention is not limited to the configuration described above, and it is obvious that other various configurations can be adopted.

  All the embodiments described above are illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in other various modifications and changes. Therefore, the scope of the present invention is defined only by the claims and their equivalents.

DESCRIPTION OF SYMBOLS 10 Magnetic disk 10a Disk board | substrate 10b Magnetization orientation layer 10c Soft magnetic backing layer 10d Intermediate | middle layer 10e Magnetic recording layer 10f Protective layer 11 Spindle motor 12 HGA
13 Thin Film Magnetic Head 14 Assembly Carriage Device 15 Pivot Bearing Shaft 16 Carriage 17 VCM
18 Drive Arm 19 Recording / Reproducing and Resonance Control Circuit 20 Load Beam 21 Flexure 22 Excitation Current Wiring Member 22a Upper Ground Conductor 22b, 22c Dielectric Layer 22d Conductor Line 23 Wire 30 Slider Substrate 30a ABS
30b Element formation surface 30c, 30d Slider end face 31 Magnetic head element 31a MR read head element 31a ₁ MR stack 31a ₂ Lower shield layer 31a ₃ Upper shield layer 31b Inductive write head element 31b ₁ main pole layer 31b ₁₁ main pole yoke layer 31b ₁₂ main pole main layer 31b ₂ trailing gap layer 31b ₃ writing coil 31b ₄ writing coil insulating layer 31b ₅ auxiliary magnetic pole layer 31b ₅₁ trailing shield part 31b ₆ auxiliary shield layer 31b ₆₁ leading shield part 31b ₇ leading gap layer 32 protection part 33, 34, 35, 36, 37 Terminal electrode 38 Line conductor 381 Left end surface 382 Right end surface 383 Lower surface 384 Upper surface 385 Position farthest from ABS 100 Resonance magnetic field 101 Write magnetic field 110 Motor driver 111 VCM driver 112 HDC
113 Computer 114 Read / Write IC Circuit 114a Head Amplifier 114b Read / Write Channel 115 Excitation Current Supply Circuit 116 Head Element Wiring Member

Claims (18)

A write magnetic field generating means for generating a write magnetic field to the magnetic recording medium in response to a write signal and the write magnetic field generating means are provided independently of each other, and the magnetic recording medium is strengthened by flowing a microwave excitation current. magnetic resonance frequency F _R or line conductor and is perpendicular and the air bearing surface in the track width direction with respect該線path conductors in the microwave radiator of planar structure shaped to emit a magnetic field for a microwave band resonance having a frequency in the vicinity thereof Inverted microstrip comprising at least one magnetic pole spaced apart in a direction parallel to the magnetic field, and wherein the microwave radiator comprises the line conductor and a ground conductor constituted by the magnetic recording medium A waveguide having opposing surfaces of the line conductor and the at least one magnetic pole parallel to each other, and a distance D between the opposing surfaces is determined by the line guide. The arc length R in the direction of the magnetic recording medium from the position farthest from the air bearing surface on the opposite surface of the body is greater than the sum (R + S) of the distance S between the line conductor and the magnetic recording medium. A thin-film magnetic head with a featured microwave band magnetic drive function.   2. The thin film magnetic head according to claim 1, wherein the arc length R is R = πA / 2, where A is a length in a direction away from the air bearing surface of the facing surface of the line conductor.   A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means The line conductor of the microwave radiator is disposed between the main magnetic pole and the auxiliary magnetic pole, and the at least one magnetic pole is the main magnetic pole and the auxiliary magnetic pole. The thin film magnetic head described in 1.   The distance between the line conductor and the main magnetic pole and the distance between the line conductor and the auxiliary magnetic pole are both greater than the sum (R + S) of the arc length R and the distance S. Thin film magnetic head.   A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means The line conductor of the microwave radiator is disposed on the opposite side of the main magnetic pole from the auxiliary magnetic pole, and the at least one magnetic pole is the auxiliary magnetic pole. The thin film magnetic head described.   6. The thin film magnetic head according to claim 5, wherein a distance between the line conductor and the auxiliary magnetic pole is larger than a sum (R + S) of the arc length R and the distance S.   7. The thin film magnetic head according to claim 1, wherein a cross section of the line conductor in a direction perpendicular to a track width direction has a rectangular shape. A magnetic recording medium having a magnetic recording layer, a write magnetic field generating means for generating a write magnetic field to the magnetic recording medium in response to a write signal, and provided independently of the write magnetic field generating means to pass a microwave excitation current track width with respect to the magnetic recording medium of ferromagnetic resonance frequency F _R or line conductor of the microwave radiator of planar structure shaped to emit a magnetic field for a microwave band resonance having a frequency in the vicinity thereof, and該線path conductors by A ground conductor having at least one magnetic pole perpendicular to the direction and spaced apart in a direction parallel to the air bearing surface, wherein the microwave radiator is constituted by the line conductor and the magnetic recording medium Inverted microstrip waveguide comprising: the opposing surfaces of the line conductor and the at least one magnetic pole are parallel to each other; The distance D between the line conductor and the arc length R in the direction of the magnetic recording medium from the position farthest from the air bearing surface on the facing surface of the line conductor, and the distance S between the line conductor and the magnetic recording medium A thin film magnetic head larger than the sum (R + S), a write signal supply unit that generates the write signal and applies it to the write magnetic field generation unit, and a micro that generates the microwave excitation current and applies it to the microwave radiator. A magnetic recording / reproducing apparatus comprising a wave excitation current supply means.   9. The magnetic recording / reproducing apparatus according to claim 8, wherein the arc length R is R = πA / 2, where A is the length of the line conductor in the direction away from the air bearing surface on the facing surface.   A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means The line conductor of the microwave radiator is disposed between the main magnetic pole and the auxiliary magnetic pole, and the at least one magnetic pole is the main magnetic pole and the auxiliary magnetic pole. 2. A magnetic recording / reproducing apparatus according to 1.   The distance between the line conductor and the main magnetic pole and the distance between the line conductor and the auxiliary magnetic pole are both larger than the sum (R + S) of the arc length R and the distance S. Magnetic recording / reproducing apparatus.   A perpendicular magnetic recording type write head element having a main magnetic pole, an auxiliary magnetic pole, and coil means wound between the main magnetic pole and the auxiliary magnetic pole, and the write magnetic field generating means is the coil means The line conductor of the microwave radiator is disposed on the opposite side of the main magnetic pole from the auxiliary magnetic pole, and the at least one magnetic pole is the auxiliary magnetic pole. The magnetic recording / reproducing apparatus as described.   13. The magnetic recording / reproducing apparatus according to claim 12, wherein a distance between the line conductor and the auxiliary magnetic pole is greater than a sum (R + S) of the arc length R and the distance S.   14. The magnetic recording / reproducing apparatus according to claim 8, wherein a cross section of the line conductor in a direction perpendicular to a track width direction has a rectangular shape.   One output terminal of the microwave excitation current supply means is connected to the line conductor of the microwave radiator, and the other output terminal of the microwave excitation current supply means is grounded by the magnetic recording medium. 15. The magnetic recording / reproducing apparatus according to claim 8, wherein the magnetic recording / reproducing apparatus is connected to a conductor via a resistor.   One end of the line conductor of the microwave radiator is grounded or terminated with a resistor equivalent to the value of the characteristic impedance of the microwave radiator, and the other end of the line conductor is microwave excitation current supply means The magnetic recording / reproducing apparatus according to claim 8, wherein the magnetic recording / reproducing apparatus is connected to the magnetic recording / reproducing apparatus.   17. The magnetic recording / reproducing apparatus according to claim 8, further comprising a direct current excitation current supply circuit that generates a direct current excitation current and applies the direct current to the microwave radiator.   At the position of the magnetic recording layer of the magnetic recording medium, the write magnetic field has a direction perpendicular or substantially perpendicular to the surface of the magnetic recording layer, and the resonance magnetic field is in the surface of the surface of the magnetic recording layer. The magnetic recording / reproducing apparatus according to claim 8, wherein the magnetic recording / reproducing apparatus is set to have a substantially in-plane direction.

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