JP2009266334A - Magnetic recording/reproducing device including thin-film magnetic head having microwave band magnetic driving function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording/reproducing device including a thin-film magnetic head having a microwave magnetic driving function, capable of highly accurately writing a data signal in a magnetic recording medium having a large coercive force without heating, preventing the damaging of a magnetic recording read/write signal circuit, and preventing the distortion of a write signal. <P>SOLUTION: The magnetic recording/reproducing device is provided with a magnetic recording medium, a thin-film magnetic head having a write magnetic field generating means and a resonance magnetic field generating means for generating a microwave band resonance magnetic field having a ferromagnetic resonance frequency F<SB>R</SB>of a magnetic recording layer or a frequency of the vicinity according to a microwave oscillating signal, a write signal generating means, a microwave oscillating means, and a combining and isolating means for combining together the microwave oscillating signal and the write signal to apply the microwave oscillating signal to the resonance magnetic field generating means and to apply the write signal to the write magnetic field generating means, and blocking the application of the microwave oscillating signal to the write signal generating means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic recording / reproducing apparatus including a thin film magnetic head with a microwave band magnetic drive function for writing a data signal on a magnetic recording medium having a large coercive force to thermally 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, and the coercive force Hc increases as Ku increases (however, in a normal recording film, Hk
> Hc).

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 thermally 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 record a signal 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 Document 3).

  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. .

JP 2001-250201 A JP 2004-158067 A JP 2007-299460 A J. Zhu, “Recording Well Below Medium Coercivity Assisted by Localized Microwave Utilizing Spin Transfer”, Digest of MMM, 2005

  However, according to this magnetic-assisted magnetic recording system in which a high-frequency alternating magnetic field is applied simultaneously with the perpendicular recording magnetic field in the in-plane direction of the magnetic recording medium, the magnetic recording signal and the signal in the microwave band of several GHz to 10 GHz are used. (Microwave excitation signal) is applied to the thin-film magnetic head, and this microwave excitation signal wraps around the magnetic recording read signal and write signal circuit (read / write IC circuit) and destroys this circuit. There is also a possibility that the write signal applied to the write head element through this read signal and write signal circuit is distorted.

  Accordingly, an object of the present invention is to provide a magnetic recording including a thin film magnetic head with a microwave band magnetic drive function capable of writing a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating. To provide a playback device.

  Another object of the present invention is to provide a magnetic recording / reproducing apparatus including a thin film magnetic head with a microwave band magnetic drive function capable of preventing damage to a read signal and write signal circuit for magnetic recording.

  It is still another object of the present invention to provide a magnetic recording / reproducing apparatus including a thin film magnetic head with a microwave band magnetic drive function that does not distort a write signal.

According to the present invention, 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 layer in response to a write signal, and a ferromagnetic resonance of the magnetic recording layer in response to a microwave excitation signal a thin film magnetic head having a frequency F _R or resonance magnetic field generating means for generating a magnetic field for a microwave band resonance having a frequency in the vicinity thereof, and the write signal generating means for generating a write signal, a micro wave for generating a microwave excitation signal The oscillation means, the microwave excitation signal generated by the microwave oscillation means, and the write signal generated by the write signal generation means are combined and applied to the resonance magnetic field generation means, and the write signal is written to the write magnetic field generation means. And a synthesizing and isolating means for blocking the application of the microwave excitation signal to the writing signal generating means And a magnetic recording / reproducing apparatus including a thin film magnetic head with a microwave band magnetic drive function.

  The synthesis and isolation means allow the microwave excitation signal to be applied to the resonant magnetic field generating means and the write signal to be applied to the write magnetic field generating means, but the microwave excitation signal is applied to the write signal generating means. It is prevented from being done. Thereby, it is possible to prevent the microwave excitation signal from being applied to the write signal generating means and damaging or destroying the write signal generating means. Further, there is no inconvenience that the microwave excitation signal is superimposed on the write signal through the write signal generating means and distorts the write signal. Of course, according to the present invention, it is possible to write data signals with high accuracy on a magnetic recording medium having a large coercive force without heating.

  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.

  Preferably, the synthesizing and isolating means includes a directional coupling means inserted between the microwave oscillating means, the write signal generating means, the write magnetic field generating means and the resonant magnetic field generating means of the thin film magnetic head.

  This directional coupling means applies a single directionality to apply an unbalanced microwave excitation signal from the microwave oscillating means to the resonant magnetic field generating means and to apply a write signal from the write signal generating means to the write magnetic field generating means. More preferably, a coupler is provided. In this case, the input port of the directional coupler is connected to the microwave oscillating means, the isolation input port of the directional coupler is connected to the write signal generating means, and the coupled output port of the directional coupler is More preferably, it is connected to the writing magnetic field generating means and the resonant magnetic field generating means.

  Further provided is a balance-unbalance conversion means in which an unbalanced input terminal is connected to the microwave oscillation means, and the directional coupling means converts the microwave excitation signal from the balance output terminal of the balance-unbalance conversion means into a resonance magnetic field generation means. It is more preferable to provide two directional couplers for applying the write signal from the write signal generating means to the write magnetic field generating means. In this case, the input port of each directional coupler is connected to the balance-unbalance conversion means, the isolation input port of each directional coupler is connected to the write signal generating means, and More preferably, the coupled output port is connected to the write magnetic field generating means and the resonant magnetic field generating means.

Synthesis and isolation means, write signal and a quarter-wave (electric length) of the ferromagnetic resonance frequency F _R from the point of attachment to the microwave excitation signal or only to a write signal generating means side length corresponding to an odd multiple thereof provided a position near, it is also preferable to contain an open stub having a length corresponding to a quarter wavelength (electrical length) or an odd multiple thereof of ferromagnetic resonance frequency F _R.

Further provided is a balance-unbalance conversion means having an unbalanced input terminal connected to the microwave oscillation means, and the synthesis and isolation means performs ferromagnetic resonance from the coupling point between the balance output of the balance-unbalance conversion means and the write signal. frequency F ¼ wavelength (electrical length) of the _R or respectively provided in a position near the length to the write signal generating means side, which corresponds to an odd multiple thereof, a quarter wavelength (electrical ferromagnetic resonance frequency F _R It is also preferable to include two open stubs having a length corresponding to (length) or an odd multiple thereof.

  It is also preferable that the balance-unbalance conversion means is composed of a planar structure type circuit. In this case, the balance / unbalance conversion means includes a coupling portion composed of an upper line conductor and a lower line conductor laminated with a dielectric interposed therebetween, and one of the upper line conductor and the lower line conductor in the coupling portion. The line width is configured to be 5% wider than the other line width, more preferably 3% wider.

  It is also preferable that the open stub is composed of a planar structure type circuit.

Line spacing of the transmission path from the write signal generating means to write magnetic field generating means, it is also preferably less than a quarter wavelength of the ferromagnetic resonance frequency F _R (electrical length).

  It is also preferable that the write magnetic field generating means and the resonant magnetic field generating means of the thin film magnetic head are different coil means, for example, a main coil and a subcoil. In this case, it is more preferable to further include demultiplexing means for separating the write signal and the microwave excitation signal and applying them to different coil means, for example, the main coil and the subcoil, respectively.

  It is also preferable that the write magnetic field generating means and the resonance magnetic field generating means of the thin film magnetic head are the same coil means, for example, the write coil is a common coil.

  A thin film magnetic head is formed on an element forming surface of a substrate having a medium facing surface, and a main magnetic pole that generates a write magnetic field from an end on the medium facing surface side during writing, and an end on the medium facing surface side Is formed such that the separated portion passes between the main magnetic pole and the auxiliary magnetic pole at least between the main magnetic pole and the auxiliary magnetic pole, and the coil means constituting the write magnetic field generating means and the resonant magnetic field generating means It is also preferable to have an inductive write head element having:

  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, it is possible to prevent the microwave excitation signal from being applied to the write signal generating means and damaging or destroying the write signal generating means. Further, there is no inconvenience that the microwave excitation signal is superimposed on the write signal through the write signal generating means and distorts the write signal.

  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.

  In FIG. 1, reference numeral 19 denotes a recording / reproducing and resonance control circuit for controlling writing and reading operations of the thin-film magnetic head 13 and controlling a microwave excitation signal for ferromagnetic resonance, which will be described later.

  As shown in FIG. 2, the HGA 12 is applied to 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 write head element of the thin film magnetic head 13. And a write head element wiring member 22 which is a transmission line for passing a write signal and a microwave excitation signal. Although not shown, the HGA 12 is also provided with a read head element wiring member for applying a constant current to the read head element to extract a read output voltage.

  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.

  Many portions of the write head element wiring member 22 are formed of strip lines having ground conductors on the upper and lower sides. 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 write head element wiring member 22, a pair of strip lines is formed in parallel with the load beam surface. In this embodiment, the tip of the strip line on the magnetic head side is connected to the terminal electrode of the write head element by wire bonding using the wire 23. On the other hand, although not shown, the read head element wiring member is formed of a normal lead conductor, and the tip thereof is connected to the terminal electrode of the read head element by wire bonding in this embodiment. 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 this embodiment, and FIG. 4 is a perspective view showing the structure of a write coil of this thin film magnetic head.

  As shown in FIG. 3, the thin film magnetic head 13 corresponds to a slider substrate 30 having an air bearing surface (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 element forming surface 30b perpendicular to the ABS 30a, the covering portion 32 provided on the element forming surface 30b so as to cover the magnetic head element 31, and the layer surface of the covering portion 32 exposed. And four terminal electrodes 33, 34, 35 and 36.

  Here, the magnetic head element 31 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, and the terminal electrodes 35 and 36 are electrically connected to the inductive write head element 31b. The terminal electrodes 33, 34, 35, and 36 are not limited to the positions shown in FIG. 3, and may be provided in any arrangement on any position of the element formation surface 30b. For example, it may be provided on the slider end surface 30c on the surface opposite to the ABS 30a.

  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 covering portion 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.

  As shown in FIG. 4, the inductive write head element 31 b includes a main magnetic pole layer 40 as a main magnetic pole that generates a write magnetic field from an end on the ABS 30 a (slider end face 30 d) side when writing a data signal, The part separated from the end part on the end face 30d) side has an auxiliary magnetic pole layer 41 as an auxiliary magnetic pole magnetically connected to the main magnetic pole layer 40, and a spiral shape, and the main magnetic pole is at least in one turn. And a write coil 42 formed so as to pass between the layer 40 and the auxiliary magnetic pole layer 41.

In the present embodiment, the entire write coil 42 is a common coil for generating a write magnetic field and for generating a resonant magnetic field. Here, by supplying a write signal from the terminal electrodes 35 and 36 to the write coil 42 via the lead layers 43 and 44, a magnetic flux serving as a write magnetic field is generated in the magnetic circuit formed by the main magnetic pole layer 40 and the auxiliary magnetic pole layer 41. Can be made. Furthermore, the write coil 42 by flowing microwave excitation signal, the ferromagnetic resonance frequency F _R, or the resonance magnetic field is a high frequency magnetic field of the microwave band having a frequency in the vicinity thereof of the magnetic recording layer of the magnetic disk occurs To do.

  Thus, by using the write coil 42 as a common coil for generating a write magnetic field and a resonance magnetic field, the configuration is simplified, and the resonance magnetic field generating coil and the write magnetic field generating coil are separated from each other. Compared with the case where it is provided, the interference of the drive current can be greatly reduced. In addition, since both the resonance magnetic field generating coil and the write magnetic field generating coil itself can be sufficiently close to the trailing gap, the generation efficiency of the write magnetic field and the resonance magnetic field is improved.

  FIG. 5 schematically shows the entire thin-film magnetic head 13 in this embodiment, and is a cross-sectional view taken along the line AA in FIG.

In the figure, 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 formation surface 30b of the slider substrate 30, an MR read head element 31a, an inductive write head element 31b, and a covering portion 32 that protects these elements are 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 formed 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.

The inductive write head element 31b is for perpendicular magnetic recording, and includes a main magnetic pole layer 31b ₁ (40), a trailing gap layer 31b ₂ , a write coil 31b ₃ (42), a write coil insulating layer 31b _4, and an auxiliary A magnetic pole layer 31b ₅ (41), an auxiliary shield layer 31b ₆ as an auxiliary shield, and a leading gap layer 31b ₇ are provided.

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.

In the present embodiment, not only a write signal but also a microwave excitation signal is allowed to flow through the write coil 31b ₃ so that a longitudinal direction is provided between the end portion of the main magnetic pole layer 31b ₁ and the trailing shield portion 31b _{51 as} will be described later. A resonance magnetic field is generated in the direction (in the plane of the magnetic disk surface or substantially in the plane and in the track direction). 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. 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.

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 (40) and the lead layers 43 and 44 (see FIG. 4) are composed 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. Has been. 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.

  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.

  FIG. 6 is a cross-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 protective layers 10f are sequentially laminated. 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 glass, 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. Since the magnetic flux 60 corresponding to the resonance magnetic field generated by energizing the microwave excitation signal to the write coil 31b ₃ (42) has a high frequency in the microwave band, the skin effect causes the trailing side of the main magnetic pole layer 31b _1. Are distributed in a large area from the surface of the magnetic recording layer 10e to the leading surface of the trailing shield part 31b ₅₁ through the magnetic recording layer 10e. For example, when the frequency is about 10 GHz, the penetration depth of the magnetic flux 60 on the surfaces of the main magnetic pole layer 31b ₁ and the trailing shield part 31b ₅₁ is about 50 nm. As a result, the resonance magnetic field does not have a large intensity in the region closer to the disk substrate 10a than the magnetic recording layer 10e, and the component is substantially parallel to the same layer surface in the magnetic recording layer 10e.

Here, the magnetization of the magnetic recording layer 10e has a direction perpendicular or substantially perpendicular to its own layer surface. This magnetic recording layer 10e, if the resonance magnetic field in the same layer plane direction corresponding to the magnetic flux 60 is applied, to a ferromagnetic resonance frequency F _R or frequency in the vicinity thereof of the magnetic recording layer the frequency of the resonance magnetic field Thus, it is possible to significantly reduce the value of the write magnetic field in the vertical direction by the magnetic flux 61 necessary for writing. Here, the range in the vicinity of the reduction effect can be expected ferromagnetic resonance frequency F _R of the write magnetic field is approximately ± 0.5 GHz.

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.

  As described above, according to the magnetic recording method described above, it is understood that a data signal can be written with high accuracy on a magnetic disk having a large coercive force without using so-called thermal assist (heating). Furthermore, according to the thin film magnetic head described above, 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. Cost can be reduced. In particular, in the present embodiment, since it is not necessary to provide a new coil, further downsizing and cost reduction are further ensured.

  FIG. 7 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 rotationally drives the magnetic disk 10, 70 is a motor driver that is a driver of the spindle motor 11, 71 is a VCM driver that is a driver of the VCM 17, and 72 is a motor driver 70 that is controlled by a computer 73. And a hard disk controller (HDC) for controlling the VCM driver 71, 74 a read / write IC circuit including a head amplifier 74a and a read / write channel 74b of the thin film magnetic head 13, 75 a microwave supply circuit for supplying a microwave excitation signal, 76 These show coupling and isolation circuits provided on the transmission line (write head element wiring member 22) to the write head element of the thin film magnetic head 13, respectively.

  The recording / reproducing and resonance control circuit 19 shown in FIG. 1 includes the above-described HDC 72, computer 73, read / write IC circuit 74, microwave supply circuit 75, coupling and isolation means 76, and the like.

  FIG. 8 is a block diagram showing a circuit configuration of a transmission line, a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit to the write head element in this embodiment, and FIG. 9 shows a specific configuration thereof. FIG.

As shown in these drawings, the read / write IC circuit 74 that outputs a balanced write signal includes an inductive write head element 13b via two directional couplers 80 and 81 provided on the microwave transmission line 22. Are connected to the write coil 13b ₃ (42). The directional couplers 80 and 81 are coupled to a microwave oscillator 83 composed of, for example, a monolithic microwave integrated circuit (MMIC) and an impedance matching circuit via a balun composed of baluns. ing. Microwave oscillator 83, the ferromagnetic resonance frequency _{F R} or frequency near the example 1～15GHz, generating a microwave excitation signal having a. The balance-unbalance converter 82 and the microwave oscillator 83 correspond to the above-described microwave supply circuit 75, and the directional couplers 80 and 81 correspond to the coupling and isolation circuit 76.

These directional couplers 80 and 81, by superimposing the microwave excitation signal from the microwave oscillator 83 to a write signal from the read write IC circuit 74, these microwave excitation signal and the write signal to the write coil 13b ₃ Although it is allowed to be applied, it is configured to prevent the microwave excitation signal from being applied to the read / write IC circuit 74. That is, the microwave excitation signal from the microwave oscillator 83 is first converted into two signals having a phase difference of 180 ° by passing through the balance-unbalance converter 82. The balanced microwave excitation signal and the balanced write signal from the read / write IC circuit 74 are superimposed on the two directional couplers 80 and 81 and applied to the write coil 13b ₃ to apply the write head element. To drive. At this time, the microwave excitation signal does not appear on the output side of the read / write IC circuit 74 due to the characteristics of the directional couplers 80 and 81.

FIG. 10 is a diagram showing waveforms of respective parts in the present embodiment. Fig (A) represents the microwave excitation signal waveforms of the ferromagnetic resonance frequency F _R which is outputted from the microwave oscillator 83 (amplitude characteristics with respect to time), and FIG. (B) and (C) a balun 82 Represents a waveform (amplitude characteristics with respect to time) and a frequency spectrum (the horizontal axis represents frequency and the vertical axis represents amplitude) of the microwave excitation signal after being converted into a balanced signal by. FIGS. 4D and 4E show the waveform (amplitude characteristics with respect to time) and the frequency spectrum (the horizontal axis is frequency and the vertical axis is amplitude) of the write signal output from the read / write IC circuit 74. FIG. 4F shows the frequency spectrum (the horizontal axis is frequency and the vertical axis is amplitude) of the write signal after the microwave excitation signals are superimposed in the directional couplers 80 and 81. Further, FIG. 5G shows the frequency spectrum (the horizontal axis is frequency and the vertical axis is amplitude) of the write signal after the microwave excitation signal is superimposed without using a directional coupler.

As is apparent from a comparison of FIGS. 8F and 9G, directional couplers 80 and 81 are provided on the write signal transmission line 22 as in the present embodiment, and the directional couplers 80 and 81 are provided. be synthesized microwave excitation signal using, by microwave excitation signal from flowing to the read write IC circuit 74 side, the amplitude modulated waveform in the vicinity of the frequency F _R as shown by (G) appears Thus, there is no inconvenience that the write signal is distorted. Of course, the application of the microwave excitation signal can also prevent the read / write IC circuit 74 from being damaged or destroyed. Therefore, it is possible to write a data signal with high accuracy on a magnetic recording medium having a large coercive force without heating.

  FIG. 11 is a plan view illustrating a specific configuration example of the directional coupler used in the present embodiment.

One directional coupler 110 is formed by arranging two strip-shaped transmission lines 110a and 110b in parallel to each other in a horizontal plane parallel to the substrate surface. The length of the transmission lines 110a and 110b has a quarter wavelength of the frequency _{F R} of the microwave excitation signal coupling (electrical length). Similarly, the other directional coupler 111 is formed by arranging two strip-shaped transmission lines 111a and 111b in parallel to each other in a horizontal plane parallel to the substrate surface. The length of the transmission lines 111a and 111b also has a quarter wavelength of the frequency _{F R} of the microwave excitation signal coupling (electrical length).

  In the configuration example shown in FIG. 11, two strip-shaped transmission lines are arranged in parallel to each other in a horizontal plane, but the two strip-shaped transmission lines are superposed in a direction perpendicular to the horizontal plane. Of course, similar directional couplers can be obtained even if they are arranged parallel to each other.

  FIG. 12 is a characteristic diagram schematically showing the frequency characteristics of the directional coupler shown in FIG. The horizontal axis represents frequency and the vertical axis represents amplitude.

In the figure, a indicates the frequency characteristic from terminal-1 to terminal-2, and the write signal from the read / write IC circuit propagates with little loss and appears at terminal-2 and is applied to the write coil. b shows the frequency characteristic of the terminal -3 to terminal -2, microwave excitation signal from the microwave oscillator appears at pin -2 only near the frequency F _R is propagated, it is applied to the write coil . c shows the frequency characteristic of the terminal -3 to terminals -1, since it is greatly attenuated in the vicinity of the frequency F _R, the microwave excitation signal from the microwave oscillator not appear almost terminals -1, Therefore, this microwave excitation signal is not applied to the read / write IC circuit.

  FIG. 13 shows a specific configuration of a transmission line (write head element wiring member), a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit to a write head element according to another embodiment of the present invention. It is a circuit diagram. In this embodiment, a thin film magnetic head driven by an unbalanced write signal is used. However, in FIG. 13, the same reference numerals are used for the same components as in FIG.

  As shown in FIG. 13, the present embodiment is configured such that an unbalanced write signal is output from the read / write IC circuit 130 and applied to the inductive write head element of the thin film magnetic head. Therefore, the microwave supply circuit does not include a balance / unbalance converter, and the microwave excitation signal from the microwave oscillator 83 is directly applied to the single directional coupler 80. . One terminal of the write coil 131 is connected to the directional coupler 80, and the other terminal of the write coil 131 is directly connected to the read / write IC circuit 130.

  Other configurations of the recording / reproducing and resonance control circuit in the present embodiment, the operational effects of the present embodiment, and the like are exactly the same as those in the embodiment of FIG.

  FIG. 14 is a perspective view schematically showing an entire thin film magnetic head in still another embodiment of the present invention, and FIG. 15 is a perspective view showing the structure of a write coil of the thin film magnetic head. This embodiment uses a thin film magnetic head in which a main coil that generates a write magnetic field and a sub-coil that generates a microwave band resonance magnetic field are provided independently, and further, a write signal and a microwave excitation signal are transmitted. This is a case where the transmission line is shared and propagated and then applied separately.

  As shown in FIG. 14, the thin film magnetic head corresponds to a slider substrate 140 having an ABS 140a processed so as to obtain an appropriate flying height, and one side surface when the ABS 140a is a bottom surface, and is perpendicular to the ABS 140a. The magnetic head element 141 provided on the element forming surface 140b, the covering portion 142 provided on the element forming surface 140b so as to cover the magnetic head element 141, and the five terminals exposed from the layer surface of the covering portion 142 Electrodes 143, 144, 145, 146 and 147 are provided.

  Here, the magnetic head element 141 includes an MR read head element 141a for reading a data signal and an inductive write head element 141b for writing the data signal, and the terminal electrodes 143 and 144 are MR read. The terminal elements 145, 146, and 147 are electrically connected to the head element 141a, and the terminal electrodes 145, 146, and 147 are electrically connected to the inductive write head element 141b. The terminal electrodes 143, 144, 145, 146 and 147 are not limited to the positions shown in FIG. 14, and may be arranged in any position on the element formation surface 140b. Further, for example, it may be provided on the slider end surface 140c on the surface opposite to the ABS 140a.

  In the MR read head element 141a and the inductive write head element 141b, one end of each element reaches the slider end face 140d on the surface on the ABS 140a side. Here, the slider end surface 140 d is a surface other than the ABS 140 a among the medium facing surfaces facing the magnetic disk of the thin film magnetic head, and is mainly a surface composed of the end surface of the covering portion 142. When one end of the MR read head element 141a and the inductive write head element 141b 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 DLC may be applied to one end of each element reaching the slider end surface 140d and the vicinity thereof for protection.

  As shown in FIG. 15, the inductive write head element 141b includes a main magnetic pole layer 150 as a main magnetic pole in which a write magnetic field is generated from an end on its ABS 140a (slider end face 140d) side when a data signal is written, The auxiliary magnetic pole layer 151 as an auxiliary magnetic pole that is magnetically connected to the main magnetic pole layer 150, and a portion separated from the end on the side of the end face 140d) have a spiral shape, and the main magnetic pole is at least in one turn. And a write coil 152 formed so as to pass between the layer 150 and the auxiliary magnetic pole layer 151.

  In this embodiment, the write coil 152 has a three-layer structure in which a write coil layer 152a and a resonance coil layer 152b are stacked with an insulating layer in between, and the remaining portion is a single layer. This is a write coil section 152c. The write coil layer 152a and the write coil portion 152c constitute a main coil that generates a write magnetic field. That is, using the terminal electrodes 145 and 146, a write signal is caused to flow from the outer peripheral end of the write coil 152 to the inner peripheral end via the write coil layer 152 a and then the write coil portion 152 c. As a result, a write magnetic field is generated in the magnetic circuit formed by the main magnetic pole layer 150 and the auxiliary magnetic pole layer 151.

The resonance coil layer 152b is provided as one layer of a three-layer structure in a portion from the outer peripheral end of the write coil 152 to the intermediate portion of the write coil 152, and constitutes a sub coil. By applying a microwave excitation signal to the resonance coil layer 152b using the terminal electrodes 145 and 147, the magnetic resonance frequency of the magnetic recording layer of the magnetic disk is formed in the magnetic circuit formed by the main magnetic pole layer 150 and the auxiliary magnetic pole layer 151. F _R or the resonance magnetic field is a high frequency magnetic field of the microwave band having a frequency in the vicinity thereof occurs. The resonance coil layer 152 b extends to the outermost periphery of the write coil 152.

  A tap lead layer 155 is electrically connected and provided at an intermediate portion of the write coil 152 and an end portion on the inner peripheral side of the resonance coil layer 152b. That is, the tap lead layer 155 electrically connects the end portion on the inner peripheral side of the resonance coil layer 152 b and the terminal electrode 147. The inner peripheral end of the write coil layer 152a and the outer peripheral end of the write coil portion 152c are electrically connected. Here, the write coil layer 152a and the write coil portion 152c may be formed of a single conductive material. Further, the outer peripheral end of the write coil layer 152c and the terminal electrode 145 are electrically connected by a lead layer 153, and the inner peripheral end of the write coil portion 152c and the terminal electrode 146 are electrically connected by a lead layer 154, respectively. ing.

  Thus, by making the resonance coil layer 152b a part of the write coil 152, the number of turns of the resonance coil layer 152b is limited, and an increase in effective inductance in the microwave band can be further reduced. Further, compared with the case where the resonance coil layer is provided separately from the write coil 152, the interference of the drive current can be greatly reduced. Of course, it is obvious that the present invention can be realized even if the sub-coil for generating the resonant magnetic field and the main coil for generating the write magnetic field are provided apart from each other.

  Further, since the resonance coil layer 152b extends to the outermost periphery of the write coil 152, both the resonance coil layer 152b and the write coil 152 themselves can be made sufficiently close to the trailing gap. The generation efficiency of the magnetic field is improved.

  FIG. 16 schematically shows the entire thin-film magnetic head in this embodiment, and is a cross-sectional view taken along line AA of FIG.

In the figure, reference numeral 140 denotes a slider substrate made of Al ₂ O ₃ —TiC or the like, and has an ABS 140a facing the magnetic disk surface. On the element formation surface 140b of the slider substrate 140, an MR read head element 141a, an inductive write head element 141b, and a covering portion 142 that protects these elements are mainly formed.

MR read head element 141a includes a MR stack 141a _1, and a lower shield layer 141a ₂ and the upper shield layer 141a ₃ disposed at positions sandwiching the laminate. The MR stack 141a ₁ is made of a CIP-GMR multilayer film, a CPP-GMR multilayer film, or a TMR multilayer film, and senses a signal magnetic field from a magnetic disk with very high sensitivity. The lower shield layer 141a ₂ and the upper shield layer 141a ₃ prevent the MR multilayer 141a _{1 from} being affected by an external magnetic field that causes noise.

When the MR multilayer 141a 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 141a ₂ and the upper shield layer 141a ₃ and the MR multilayer 141a _1. Each layer is provided. Further, an MR lead conductor layer for supplying a sense current to the MR multilayer 141a ₁ and taking out a reproduction output is formed. Meanwhile, MR stack 141a ₁ may include a CPP-GMR multilayer film or a TMR multilayered film also functions as each of the lower shield layer 141a ₂ and the upper shield layer 141a ₃ upper and lower electrode layers. In this case, the lower shield gap layer, the upper shield gap layer, and the MR lead conductor layer are unnecessary. Although not shown, an insulating layer or a bias insulating layer and a hard bias layer for applying a longitudinal bias magnetic field that stabilizes the magnetic domain structure are formed on both sides of the MR multilayer 141a _{1 in} the track width direction. The

For example, when the MR multilayer 141a ₁ includes a TMR multilayer film, an antiferromagnetic layer having a thickness of about 5 to 15 nm made of IrMn, PtMn, NiMn, RuRhMn, or the like, and two ferromagnetic films such as CoFe, for example, are Ru. A magnetization fixed layer whose magnetization direction is fixed by an antiferromagnetic layer, and a thickness of 0.5 to 5 made of Al, AlCu, Mg, or the like, for example. A tunnel barrier layer made of a nonmagnetic dielectric film in which a metal film of about 1 nm is oxidized by oxygen introduced into a vacuum apparatus or by natural oxidation, a ferromagnetic film made of, for example, CoFe, etc., and a NiFe film, etc. A magnetization free layer comprising a ferromagnetic film having a thickness of about 3 to 4 nm and a tunnel exchange coupling with the magnetization fixed layer via the tunnel barrier layer; It has sequentially stacked.

Further, the lower shield layer 141a ₂ and the upper shield layer 141a ₃ are formed by using, for example, a pattern plating method including a frame plating method or the like and having a thickness of about 0.1 to 3 μm, such as NiFe, CoFeNi, CoFe, FeN, or FeZrN. It is composed of a film or the like.

The inductive write head element 141b is for perpendicular magnetic recording, and includes a main magnetic pole layer 141b ₁ (150), a trailing gap layer 141b ₂ , a write coil 141b ₃ (152), a write coil insulating layer 141b _4, and an auxiliary A magnetic pole layer 141b ₅ (151), an auxiliary shield layer 141b ₆ as an auxiliary shield, and a leading gap layer 141b ₇ are provided.

The main magnetic pole layer 141b ₁ transmits a magnetic flux generated by applying a write current to the main coil (the write coil layer 152a and the write coil unit 152c) of the write coil 141b ₃ up to the magnetic recording layer of the magnetic disk on which writing is performed. This is a magnetic path for guiding while converging, and is composed of a main magnetic pole yoke layer 141b ₁₁ and a main magnetic pole main layer 141b ₁₂ . Here, the length (thickness) in the layer thickness direction at the end of the main magnetic pole layer 141b _{1 on} the ABS 140a (slider end surface 140d) side corresponds to the thickness of the main magnetic pole main layer 141b ₁₂ alone, and becomes smaller. 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. Main pole yoke layer 141b ₁₁ and the main magnetic pole main layer 141b ₁₂ is, for example, a sputtering method, formed using a pattern plating process or the like including a frame plating thickness 0.5~3.5μm about and thickness, respectively It is composed of a NiFe, CoFeNi, CoFe, FeN or FeZrN film having a thickness of about 0.1 to 1 μm.

The auxiliary magnetic pole layer 141b ₅ and the auxiliary shield layer 141b ₆ are disposed on the trailing side and the leading side of the main magnetic pole layer 141b ₁ , respectively. As described above, the auxiliary magnetic pole layer 141b ₅ is magnetically connected to the main magnetic pole layer 141b ₁ at a portion separated from the end portion on the ABS 140a (slider end surface 140d) side, but the auxiliary shield layer 141b ₆ not the main magnetic pole layer 141b ₁ and magnetically connected in this embodiment.

Each end of the slider end surface 140d side of the auxiliary magnetic pole layer 141b ₅ and the auxiliary shielding layer 141b _6, the layer cross-section has a broad trailing shield section 141b ₅₁ and leading shield section 141b ₆₁ than other portions. The trailing shield part 141b ₅₁ is opposed to the end part on the slider end face 140d side of the main magnetic pole layer 141b ₁ via the trailing gap layer 141b ₂ . Also, leading shield section 141b ₆₁ is opposed through the end portion and the leading gap layer 141b ₂ of the slider end surface 140d side of the main magnetic pole layer 141b _1. By providing such a trailing shield part 141b ₅₁ and a leading shield part 141b ₆₁ , due to the shunt effect of magnetic flux, between the trailing shield part 141b ₅₁ and the end of the main magnetic pole layer 141b ₁ , and the leading shield part 141b. _The magnetic field gradient of the write magnetic field between the end portion _{61 and} the end portion of the main magnetic pole layer 141b ₁ 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 141b ₅ or the auxiliary shield layer 141b ₆ is appropriately processed, and a part of the auxiliary magnetic pole layer 141b ₅ or the auxiliary shield layer 141b ₆ is arranged near both sides of the main magnetic pole layer 141b _{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 141b ₅₁ and the leading shield part 141b _{61 in} the layer thickness direction is set to about several tens to several hundreds times the thickness of the main magnetic pole layer 141b _{1 in} the same direction. It is preferable. In addition, the gap length of the trailing gap layer 141b 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 141b ₇ is preferably 0.1μm or more.

The auxiliary magnetic pole layer 141b ₅ and the auxiliary shield layer 141b ₆ are, 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 Further, the trailing gap layer 141b ₂ or the leading gap layer 141b ₇ is formed by using, for example, a sputtering method, a CVD method, or the like, and has a thickness of about 0.1 to ₃ μm of Al ₂ O ₃ , SiO ₂ , AlN, or DLC. It consists of a film or the like.

In the present embodiment, the resonance coil layer 152b is provided as one layer of a three-layer structure in the portion from the outer peripheral side end portion of the write coil 152 to the intermediate portion thereof, and the lead layer 153, the tap lead layer 155, It has become a part between. The resonance coil layer 152b is separated from the write coil layer 152a with the insulating layer 152d interposed therebetween. Note that the stacking order of the three-layer structure may be the resonant coil layer 152b, the insulating layer 152d, and the write coil layer 152a as in this embodiment, or vice versa. Here, the resonance coil layer 152 b, is applied to the microwave excitation signal, the in-plane or substantially in-plane direction of the longitudinal direction (magnetic disk surface between the end portion of the main magnetic pole layer 141b ₁ and the trailing shield portion 141b ₅₁ And a magnetic field for resonance in the track direction) is generated. 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. 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.

Write coil insulating layer 141b ₄ surrounds the write coil 141b _3, is provided in order to electrically insulate the write coil 141b ₃ from around the magnetic layer. The write coil portion 152c, the write coil layer 152a, the resonance coil layer 152b, the tap lead layer 155, and the lead layers 154 and 153 have a thickness of 0.1 to 5 μm formed by using, for example, a frame plating method or a sputtering method. It is composed of a Cu film or the like. The write coil insulating layer 141b ₄ is composed of, for example, a heat-cured photoresist having a thickness of about 0.5 to 7 μm formed by using a photolithography method or the like. Furthermore, the insulating layer 152d is formed of, for example, Al ₂ O ₃ , SiO ₂ having a thickness of about 0.1 to 2 μm, using the same photoresist as the write coil insulating layer 141b ₄ or a sputtering method, a CVD method, or the like. ₂ etc.

  Although the configuration of the thin film magnetic head 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 various other configurations can be adopted.

  FIG. 17 is a circuit diagram showing a specific configuration of a transmission line (write head element wiring member), a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit to the write head element in the present embodiment. . However, in the figure, the same reference numerals are used for the same components as in FIG.

  As shown in FIG. 17, a read / write IC circuit 74 that outputs a balanced write signal is connected to a duplexer 170 via two directional couplers 80 and 81 provided on a microwave transmission line. The duplexer 170 is connected to a main coil 171 that generates a write magnetic field of the inductive write head element and a subcoil 172 that generates a magnetic field for microwave band resonance. The directional couplers 80 and 81 are coupled to a microwave oscillator 83 composed of, for example, an MMIC and an impedance matching circuit via a balance-unbalance converter 82 composed of, for example, a balun. The balun 82 and the microwave oscillator 83 correspond to the microwave supply circuit 75 (see FIG. 7), and the directional couplers 80 and 81 correspond to the coupling and isolation circuit 76 (see FIG. 7). ing.

  These directional couplers 80 and 81 superimpose the microwave excitation signal from the microwave oscillator 83 on the write signal from the read / write IC circuit 74, so that the microwave excitation signal and the write signal are demultiplexer 170, Therefore, it is allowed to be applied to the main coil 171 and the subcoil 172, but it is configured to prevent the microwave excitation signal from being applied to the read / write IC circuit 74. That is, the microwave excitation signal from the microwave oscillator 83 is first converted into two signals having a phase difference of 180 ° by passing through the balance-unbalance converter 82. The balanced microwave excitation signal and the balanced write signal from the read / write IC circuit 74 are superimposed on the two directional couplers 80 and 81 and applied to the duplexer 170. At this time, the microwave excitation signal does not appear on the output side of the read / write IC circuit 74 due to the characteristics of the directional couplers 80 and 81.

  The demultiplexer 170 is a separating means for separating the write signal and the microwave excitation signal that are propagated by sharing the transmission line, and the write signal separated by this is applied to the main coil 171 and the microwave excitation is performed. A signal is applied to the secondary coil 172 to drive the write head element.

  Other configurations of the recording / reproducing and resonance control circuit in the present embodiment, the operational effects of the present embodiment, and the like are exactly the same as those in the embodiment of FIG.

  FIG. 18 shows specific configurations of a transmission line (write head element wiring member), a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit to a write head element in still another embodiment of the present invention. FIG. This embodiment uses a thin film magnetic head in which a main coil that generates a write magnetic field and a subcoil that generates a magnetic field for microwave band resonance are provided independently and is driven by an unbalanced write signal. In this case, the write signal and the microwave excitation signal are propagated by sharing the transmission line and then applied separately. However, in FIG. 18, the same reference numerals are used for the same components as in FIG.

  As shown in FIG. 18, in the present embodiment, an unbalanced write signal is output from the read / write IC circuit 130, and this is output via the directional coupler 80 and the duplexer 180 to the main coil 181 of the inductive write head element. It is comprised so that it may be applied to. Therefore, the microwave supply circuit does not include a balance / unbalance converter, and the microwave excitation signal from the microwave oscillator 83 is directly applied to the single directional coupler 80. . A branching filter 180 is connected to the directional coupler 80, and one terminal of the main coil 181 and the subcoil 182 is connected to its output terminal, and the other terminal of the main coil 181 and the subcoil 182 is connected. The terminals are directly connected to the read / write IC circuit 130.

  The duplexer 180 is a separating means for separating the write signal and the microwave excitation signal propagated using the transmission line in common, and the write signal separated by this is applied to the main coil 181 and the microwave excitation is performed. A signal is applied to the subcoil 182 to drive the write head element.

  Other configurations of the recording / reproducing and resonance control circuit in the present embodiment, the operational effects of the present embodiment, and the like are exactly the same as those in the embodiment of FIGS.

  19 is a circuit diagram showing a specific configuration of a transmission line to a write head element, a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit according to still another embodiment of the present invention. FIG. 21 is a developed plan view showing a specific configuration example of the transmission line and the coupling and isolation circuit shown in FIG. 19, and FIG. 21 is a cross-sectional view of the transmission line shown in FIG. In the present embodiment, the transmission line is constituted by a waveguide having a planar structure such as a microstrip line or a strip line, and an open stub is used for a coupling and isolation circuit. However, in FIG. 19, the same reference numerals are used for the same components as those in FIGS. 8 and 9.

As shown in FIG. 19, the read / write IC circuit 74 that outputs a balanced write signal has a write coil 13b ₃ (42) of the inductive write head element via a transmission line having a planar structure such as a microstrip line or a strip line. )It is connected to the. When the transmission line 190 is a microstrip line, as shown in FIGS. 20 and 21, a dielectric substrate 190a, a strip-shaped line conductor 190b formed on the surface of the dielectric substrate 190a, and a dielectric substrate 190a. And a ground conductor 190c formed on the back surface of the main body. 20A shows a conductor portion formed on the surface of the dielectric substrate 190a, and FIG. 20B shows a conductor portion formed inside the dielectric substrate 190a.

The transmission line 190 is connected to a balanced output terminal of a balun 82 having a planar structure which is a balanced / unbalanced converter. The unbalanced input terminal of the balun 82 is configured by MMIC and impedance matching circuit, a microwave generating microwave excitation signal having ferromagnetic resonance frequency F _R or frequency near the example 1～15GHz, the An oscillator 83 is connected. The balun 82, in the present embodiment mainly comprises four strip conductors 82a~82d having a length _{L 3} of the quarter wavelength of the ferromagnetic resonance frequency _{F R} is the frequency of the microwave excitation signal (electrical length) The strip conductors 82a and 82b connected to the unbalanced input terminal are formed inside the dielectric substrate 190a. As can be clearly seen from FIG. 21, strip conductors 82c and 82d connected as balanced output terminals to the coupling point 192 with the line conductor 190b are formed on the surface of the dielectric substrate 190a. The strip conductors 82c and 82d are configured to be vertically coupled to face the strip conductors 82a and 82b inside the dielectric substrate 190a. That is, the lower strip conductor 82a and the upper strip conductor 82c are opposed to each other to form a coupling portion, and the lower strip conductor 82b and the upper strip conductor 82d are opposed to each other to constitute a coupling portion. is doing.

Balun 82 and the quarter-wave (electric length) of the ferromagnetic resonance frequency _{F R} from the coupling point 192 or the line conductor 190b of the position by the length _{L 2} by the read write IC circuitry 74 direction corresponding to an odd multiple thereof , each ferromagnetic resonance frequency F 1/4 wavelength (electrical length) of the _R or two open stub 191 consisting of a strip conductor of a length L ₁ corresponding to an odd multiple thereof is connected.

Since the input impedance at the base of the open stub 191 having such a length L ₁ is very small close to zero, the input impedance at the coupling point 192 that is a distance L ₂ away from the input stub 191 becomes very large. As a result, the microwave excitation signal from the balun 82 is reflected at this position and is prevented from being applied to the read / write IC circuit 74. In this way, by providing the open stub 191 having the length L ₁ at a position away from the coupling point 192 by the distance L ₂ , the microwave excitation signal from the balun 82 is superimposed on the write signal from the read / write IC circuit 74. The microwave excitation signal and the write signal are allowed to be applied to the write coil 13 b ₃ , but the microwave excitation signal is prevented from being applied to the read / write IC circuit 74. That is, the microwave excitation signal from the microwave oscillator 83 is converted into two signals having a phase difference of 180 ° by first passing through the balun 82. A microwave excitation signal becomes the equilibrium, and the balanced write signal from the read write IC circuit 74, is superimposed in the bonding points 192 are applied to the write coil 13b ₃ for driving the write head element. At this time, the microwave excitation signal does not appear on the output side of the read / write IC circuit 74 due to the effect of the open stub 191.

_One of the width W ₁ (see FIG. 21) of the lower strip conductors 82a and 82b constituting the coupling portion and the width W ₂ (see FIG. 21) of the upper strip conductors 82c and 82d is 5 at most with respect to the other. It is desirable to configure so as to be wider by 3%, and it is more desirable to configure so as to be wider by 3% at the maximum. This makes it possible to absorb manufacturing variations while keeping the loss change in coupling within an allowable range. Hereinafter, this point will be described in detail.

  FIG. 22 is a characteristic diagram showing a change in coupling loss with respect to the ratio of the lower strip conductor and the upper strip conductor width.

However, this characteristic is that the width W ₁ of the lower strip conductor is constant at W ₁ = 0.5 mm, the width W ₂ of the upper strip conductor is decreased, and the conductor width ratio W ₂ / W ₁ is −2%, This is a change in coupling loss between the lower strip conductor and the upper strip conductor when −3%, −4%, and −5%. The thickness of the lower strip conductor and the upper strip conductor is constant. The width W ₂ of the upper strip conductors is constant, it is clear that the lower strip conductors Similar results the width W ₁ reduced is obtained.

From the figure, it can be seen that if the conductor width ratio W ₂ / W ₁ is within 3%, the coupling loss change is within the range of ± 1 dB. Therefore, it is desirable that one of the width W ₂ of width W ₁ and the upper strip conductors of the lower strip conductor is configured to be 3% wider at the maximum with respect to the other.

  Actually, in order to absorb variations in accuracy when the strip conductor is formed by etching, it is desirable that one of the conductors is widened by 5% at the maximum relative to the other. Hereinafter, this point will be described.

  In the magnetic disk drive, the wiring member, particularly the wiring member substrate in the HGA portion, is a flexible substrate made of polyimide (with a dielectric constant of about 3.5), and the conductor width formed thereon is 0.5 mm to It is about 1.0 mm. When forming a lower strip conductor and an upper strip conductor on such a substrate, etching is usually used, but it is formed depending on whether this etching is performed normally, overetched, or underetched. The width of the conductors to be used will be different.

  FIG. 23 is a diagram for explaining the difference in conductor width due to this etching.

  In the figure, a represents the side surface of the conductor when normal etching is performed, and the conductor width in this case is assumed to be W. b represents the side surface of the conductor when over-etching is performed, and c represents the side surface of the conductor when under-etching is performed. The maximum angle between the conductor side surface b when over-etching is performed and the conductor side surface c when under-etching is performed and the conductor plane is 45 °. Therefore, when over-etching is performed, the conductor width is minimum (W−2t). When under etching is performed, the conductor width is (W + 2t) at the maximum. Where t is the thickness of the conductor.

  There are multiple types of conductors (copper foil) formed on a flexible substrate, such as 18 μm, 35 μm, and 70 μm. However, when microwaves are used, current flows only on the surface due to the skin effect, and the thinner one is Usually, 18 μm copper foil is used because it is inexpensive and does not impair the flexibility of the HGA suspension. Therefore, the conductor width has a maximum variation of 36 μm (0.036 mm).

  The reason why the conductor width has the largest variation between the upper strip conductor and the lower strip conductor is that, for example, as shown in FIG. 24, the upper strip conductor is over-etched and the lower strip conductor is normally etched or This is a case of under etching. In this case, since the width of the lower surface of the upper strip conductor is narrowed by a conductor thickness 2t which is twice as much as the maximum, if the width of the upper strip conductor is increased by that amount, that is, 2t, the upper strip conductor and the lower strip conductor are formed. The amount of binding with will not change. Here, 2t = 36 μm (0.036 mm) corresponds to a variation of about 7.2% of the original conductor width of 0.5 mm. However, giving a change of 7.2% is so large that the characteristic change is too large as can be seen from the characteristic diagram of FIG. 22, so if the width of the upper strip conductor is set to be 5% wider at the maximum, Even in the case of the maximum variation of 7.2%, the conductor width change is 2.2%, and as a result, it can be seen from FIG. 22 that the coupling loss change is within the range of ± 1 dB.

  When the conductor width is narrower than 0.5 mm, the maximum variation of 36 μm occupies a larger proportion. For example, when the conductor width is 0.2 mm, 0.036 / 0.2 = 17.5%. Such large variations cannot be absorbed by the correction of the conductor width, but when the conductor width changes by 17.5%, the impedance itself changes. Doing itself is a mistake. Therefore, it is out of the scope of the present invention.

  When the conductor width is wider than 0.5 mm, the maximum variation of 36 μm occupies a smaller ratio. For example, when the conductor width is 1 mm, 0.036 / 1 = 3.6%. Therefore, in this case, even if the width of the conductor is increased to some extent, the variation value of about 36 μm is originally relatively small, so that there is no problem. As described above, when the strip conductors are vertically coupled, the relative value of the variation due to etching decreases as the conductor width increases. This is therefore within the scope of the present invention.

Line distance D between the line conductor 190b in the transmission line 190 of the coplanar coupling for connecting the read write IC circuit 74 and the write coil _13b 3 of the inductive write head element (42) is a quarter wavelength of the ferromagnetic resonance frequency _{F R} It is desirable to be less than (electric length). Hereinafter, this point will be described.

  FIG. 25 is an equivalent circuit diagram when two line conductors parallel to each other are represented as a lumped constant circuit.

The transmission line, that is, two line conductors parallel to each other, is a distributed constant circuit. When this is replaced with a lumped constant circuit in order to obtain the impedance, it is expressed as shown in FIG. When the inductance of each coil element is L and the capacitance of each capacitor element is C, the impedance Z _{0 of} this line is Z ₀ = √ (L / C). Here, when the line spacing D (electric length) is sufficiently short with respect to the wavelength, the dielectric (resin, air, etc.) existing between the lines behaves as a capacitor.

On the other hand, when the line interval D (electrical length) becomes wide and cannot be ignored with respect to the wavelength, the equivalent circuit changes as shown in FIG. This is a case where the line interval D (electric length) is ¼ wavelength, and is the same equivalent circuit as when a parallel resonant circuit is connected between the lines. The impedance Z ₀ at this time is such that C in Z ₀ = √ (L / C) is
At frequencies below the resonance point of the parallel resonant circuit, it becomes a capacitor,
At frequencies exceeding the resonance point of the parallel resonant circuit, it becomes a coil,
At the resonance point, the resistance is infinite.

  When the line spacing D (electrical length) is further increased to ½ wavelength, the equivalent circuit is as shown in FIG. This is equivalent to the case where a series resonant circuit is inserted between the lines.

Thus, when the line spacing D (electrical length) is a non-negligible distance with respect to the wavelength or an integral multiple of a quarter wavelength, the denominator within the square root in Z ₀ = √ (L / C) Since the condition of the term (must be a capacitor) is not satisfied, the impedance is considerably different from the calculated value, and the role as a transmission line cannot be performed. This condition change occurs when the line interval D (electric length) is an integral multiple of a quarter wavelength. Therefore, in order to keep the condition of Z ₀ = √ (L / C), that is, to maintain the characteristics as a transmission line, the line interval D (electric length) is made as short as possible and at least less than ¼ wavelength. There is a need.

  Other configurations of the recording / reproducing and resonance control circuit in the present embodiment, the operational effects of the present embodiment, and the like are exactly the same as those in the embodiments of FIGS.

  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.

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 perspective view showing a structure of a write coil of the thin film magnetic head of FIG. 3. FIG. 4 schematically shows an entire thin film magnetic head in the embodiment of FIG. 1, and is a cross-sectional view taken along line AA of 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. FIG. 2 is a block diagram schematically showing an electrical configuration of the magnetic disk drive device in the embodiment of FIG. 1. FIG. 2 is a block diagram illustrating a circuit configuration of a transmission line, a read / write IC circuit, a microwave supply circuit, and an isolation unit to a write head element in the embodiment of FIG. 1. FIG. 9 is a circuit diagram of a specific configuration of the circuit shown in FIG. 8. It is a figure showing the waveform of each part in embodiment of FIG. FIG. 2 is a plan view illustrating a specific configuration example of a directional coupler used in the embodiment of FIG. 1. It is a characteristic view which shows typically the frequency characteristic of the directional coupler shown in FIG. It is a circuit diagram which shows the specific structure of the transmission line to the write head element in other embodiment of this invention, a read / write IC circuit, a microwave supply circuit, and a coupling | bonding and isolation circuit. It is a perspective view which shows roughly the whole thin film magnetic head in other embodiment of this invention. It is a perspective view which shows the structure of the write coil of the thin film magnetic head of FIG. FIG. 15 schematically shows an entire thin film magnetic head in the embodiment of FIG. 14 and is a cross-sectional view taken along line AA of FIG. 14. FIG. 15 is a circuit diagram illustrating a specific configuration of a transmission line, a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit to the write head element in the embodiment of FIG. 14. FIG. 10 is a circuit diagram showing a specific configuration of a transmission line to a write head element, a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit in still another embodiment of the present invention. FIG. 6 is a circuit diagram showing a specific configuration of a transmission line to a write head element, a read / write IC circuit, a microwave supply circuit, and a coupling and isolation circuit in still another embodiment of the present invention. It is a top view which expands and shows the concrete structural example of the transmission line shown in FIG. 19, a coupling | bonding, and an isolation circuit. It is sectional drawing of the transmission line shown in FIG. It is a characteristic view showing the change of coupling loss to the ratio of the lower strip conductor and the upper strip conductor width. It is a figure for demonstrating the difference in the conductor width by an etching. It is a figure explaining the case where a conductor width has the largest dispersion | variation. It is an equivalent circuit diagram in the case where two line conductors parallel to each other are represented as a lumped constant circuit.

Explanation of symbols

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 Write Head Element Wiring Member 22a Upper Ground Conductor 22b, 22c Dielectric Layer 22d Conductor Line 23 Wire 30, 140 Slider Substrate 30a, 140a ABS
30b, 140b element formation surface 30c, 30d, 140c, 140d slider end surface 31,141 magnetic head element 31a, 141a MR read head element 31a _1, 141a ₁ MR stack 31a _2, 141a ₂ a lower shield layer 31a _3, 141a ₃ upper shielding layer 31b, 141b inductive write head element 31b _1, 40,141b _1, 150 main magnetic pole layer 31b _11, 141b ₁₁ main pole yoke layer 31b _12, 141b ₁₂ main magnetic pole main layer 31b _2, 141b ₂ trailing gap layer 31b ₃ , 42,131,141b _3, 152 write coil 31b _4, 141b ₄ write coil insulating layer 31b _5, 41,141b _5, 151 auxiliary magnetic layer 31b _51, 141b ₅₁ trailing shield section 31b , 141b ₆ auxiliary shield layer 31b _61, 141b ₆₁ leading shield section 31b _7, 141b ₇ leading gap layer 32,142 covering portion 33,34,35,36,143,144,145,146,147 terminal electrodes 43 and 44, 153, 154 Lead layer 60, 61 Magnetic flux 70 Motor driver 71 VCM driver 72 HDC
73 Computer 74, 130 Read / write IC circuit 74a Head amplifier 74b Read / write channel 75 Microwave supply circuit 76 Coupling and isolation circuit 80, 81, 110, 111 Directional coupler 82 Balanced unbalanced converter 82a, 82b, 82c, 82d Strip conductor 83 Microwave oscillator 110a, 110b, 190 Transmission line 152a Write coil layer 152b Resonance coil layer 152c Write coil part 155 Tap lead layer 170, 180 Splitter 171, 181 Main coil 172, 182 Subcoil 190a Dielectric substrate 190b Line conductor 190c Ground conductor 191 Open stub 192 Connection point

Claims (18)

A magnetic recording medium having a magnetic recording layer, the ferromagnetic resonance frequency of the magnetic recording layer in response to a write magnetic field generating means and microwave excitation signal for generating a write magnetic field to the magnetic recording layer in accordance with a write signal F _R or A thin film magnetic head having a resonance magnetic field generating means for generating a microwave band resonance magnetic field having a frequency in the vicinity thereof, a write signal generating means for generating the write signal, and a microwave oscillating means for generating the microwave excitation signal And combining the microwave excitation signal generated by the microwave oscillating means and the write signal generated by the write signal generating means, applying the microwave excitation signal to the resonance magnetic field generating means, and applying the write signal to the resonance magnetic field generating means. A composition for applying to the writing magnetic field generating means and further preventing the microwave excitation signal from being applied to the writing signal generating means. And a magnetic recording / reproducing apparatus comprising a thin-film magnetic head with a microwave band magnetic drive function.   The synthesizing and isolating means includes directional coupling means inserted between the microwave oscillating means, the write signal generating means, the write magnetic field generating means and the resonant magnetic field generating means of the thin film magnetic head. The magnetic recording / reproducing apparatus according to claim 1, wherein:   The directional coupling means simply applies an unbalanced microwave excitation signal from the microwave oscillating means to the resonant magnetic field generating means and applies a write signal from the write signal generating means to the write magnetic field generating means. 3. The magnetic recording / reproducing apparatus according to claim 2, further comprising a directional coupler.   An input port of the directional coupler is connected to the microwave oscillating means, an isolation input port of the directional coupler is connected to the write signal generating means, and a combined output of the directional coupler 4. The magnetic recording / reproducing apparatus according to claim 3, wherein a port is connected to the write magnetic field generating means and the resonance magnetic field generating means.   The microwave oscillation means further includes a balance / unbalance conversion means having an unbalanced input terminal connected thereto, and the directional coupling means outputs the microwave excitation signal from the balance output terminal of the balance / unbalance conversion means. 3. A magnetic recording / reproducing apparatus according to claim 2, further comprising two directional couplers for applying the write signal from the write signal generating means to the write magnetic field generating means and applying the write signal to the resonant magnetic field generating means. apparatus.   An input port of each directional coupler is connected to the balance-unbalance conversion means, and an isolation input port of each directional coupler is connected to the write signal generating means, and each directional coupling 6. The magnetic recording / reproducing apparatus according to claim 5, wherein a coupled output port of the detector is connected to the write magnetic field generating means and the resonance magnetic field generating means. The synthesis and isolation means, the quarter wavelength (electrical length) of the ferromagnetic resonance frequency F _R from the point of attachment to the write signal and the microwave excitation signal or the length the write corresponding to an odd multiple thereof provided in a position closer to the signal generating means side, characterized in that it contains an open stub quarter wavelength (electrical length) or a length corresponding to an odd multiple of said ferromagnetic resonance frequency F _R The magnetic recording / reproducing apparatus according to claim 1. The microwave oscillation means further comprises a balance-unbalance conversion means having an unbalanced input terminal connected thereto, and the combining and isolation means is a coupling point between the balance output of the balance-unbalance conversion means and the write signal. respectively provided on the ferromagnetic resonance frequency F 1/4 wavelength (electrical length) of the _R or a position near by a length corresponding to the write signal generating means side to an odd multiple thereof from, the ferromagnetic resonance frequency F _R 2. The magnetic recording / reproducing apparatus according to claim 1, comprising two open stubs each having a length corresponding to a quarter wavelength (electrical length) of 1 or an odd multiple thereof.   9. The magnetic recording / reproducing apparatus according to claim 8, wherein the balance-unbalance conversion means is composed of a planar structure type circuit.   The balance-unbalance conversion means includes a coupling portion composed of an upper line conductor and a lower line conductor laminated with a dielectric interposed therebetween, and one line width of the upper line conductor and the lower line conductor in the coupling portion. 10. The magnetic recording / reproducing apparatus according to claim 9, wherein is configured to be 5% wider than the other line width.   The balance-unbalance conversion means includes a coupling portion composed of an upper line conductor and a lower line conductor laminated with a dielectric interposed therebetween, and one line width of the upper line conductor and the lower line conductor in the coupling portion. 10. The magnetic recording / reproducing apparatus according to claim 9, wherein is configured to be 3% wider than the other line width.   12. The magnetic recording / reproducing apparatus according to claim 7, wherein the open stub is constituted by a circuit having a planar structure. The line spacing of the transmission path from the write signal generating means to the write magnetic field generating means, the ferromagnetic resonance frequency F 12 from claim 7, characterized in that _R is less than a quarter wavelength (electrical length) of The magnetic recording / reproducing apparatus of any one of Claims 1.   14. The magnetic recording / reproducing apparatus according to claim 1, wherein the write magnetic field generating means and the resonance magnetic field generating means of the thin film magnetic head are different coil means.   15. The magnetic recording / reproducing apparatus according to claim 14, further comprising demultiplexing means for separating the write signal and the microwave excitation signal and applying them to the different coil means.   14. The magnetic recording / reproducing apparatus according to claim 1, wherein the write magnetic field generating means and the resonance magnetic field generating means of the thin film magnetic head are the same coil means.   The thin film magnetic head is formed on an element forming surface of a substrate having a medium facing surface, and a main magnetic pole for generating a write magnetic field from an end on the medium facing surface side during writing and an end on the medium facing surface side Are formed such that a portion separated from the auxiliary magnetic pole magnetically connected to the main magnetic pole and at least between the main magnetic pole and the auxiliary magnetic pole, the write magnetic field generating means and the resonance magnetic field generation 17. A magnetic recording / reproducing apparatus according to claim 1, further comprising an inductive write head element having coil means constituting the means.   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 1, wherein the magnetic recording / reproducing apparatus is set to have a substantially in-plane direction.

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