JP2006303097A - Magnetoresistance effect element, thin-film magnetic head with it, head-gimbals assembly with thin-film magnetic head, magnetic disk drive with head-gimbals assembly and method for reproducing magnetic recording using thin-film magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an MR effect element capable of realizing both a reproducing output being not subject to the effect of an ambient-temperature history, being stable and having low noises and a high reproducing sensibility. <P>SOLUTION: The MR effect element has an MR laminate receiving a magnetic field and changing its own resistance value. The MR effect element is provided as having a conductive magnetic-path means capable of applying a bias magnetic field to the MR laminate, and a magnetic-flux variable means capable of inducing magnetic fluxes having at least two dimensions to the conductive magnetic-path means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetoresistive (MR) effect element, a thin film magnetic head having the MR effect element as a read magnetic head element, a head gimbal assembly (HGA) having the thin film magnetic head, and a magnetic disk apparatus having the HGA. (HDD). Furthermore, the present invention relates to a magnetic recording / reproducing method using such a thin film magnetic head.

  In recent years, magnetoresistive (MR) effect elements such as giant magnetoresistive (GMR) effect elements or tunneling magnetoresistive (TMR) effect elements have been used as read magnetic head elements in thin film magnetic heads in order to cope with the large capacity and miniaturization of HDDs. Widely adopted. By using these elements, it is possible to read a signal magnetic field with very high sensitivity and obtain a large reproduction output.

  Here, in order to further reduce the capacity of the HDD, it is necessary to increase the recording density. At this time, it is necessary to further reduce the width in the track width direction and the gap length of the magnetic head element. However, such a further reduction in size reduces the reproduction output of the MR effect element by reducing the perceivable signal magnetic flux. Bring.

  As a countermeasure against the deterioration of the reproduction output, for example, in Patent Document 1, a flux guide protruding from the shield layer is provided in the vicinity of the free layer of the MR effect element so that the reproduction sensitivity does not cause a baseline shift of the reproduction output waveform. Techniques for improving the above are disclosed.

JP 2004-265517 A

  However, even in the conventional MR element to which the above-mentioned measures are taken, there are problems that the reproduction output deteriorates or the noise during the reproduction output increases when experiencing various temperature environments.

  Currently, HDDs are widely installed in notebook personal computers, mobile phones, and other mobile devices, and are actively used as storage for large-capacity information such as music and video. These devices have many outdoor use opportunities due to their portability, and the use temperature range is considerably wide, such as use in direct sunlight and below freezing.

  However, depending on the environmental temperature history experienced by the conventional MR effect element as described above, the reproduction output of the MR effect element may be deteriorated or the noise during the reproduction output may increase. In order to suppress such a phenomenon, for example, it has been found that it is effective to increase the strength of the bias magnetic field in the track width direction that is normally applied to the MR multilayer of the MR effect element. However, if the bias magnetic field strength is set high, the reproduction sensitivity for sensing the signal magnetic field is lowered, and as a result, the reproduction output is deteriorated. That is, it has been very difficult to set a bias magnetic field that achieves both reproduction output stability and reproduction sensitivity with respect to environmental temperature history.

  Accordingly, an object of the present invention is to provide an MR effect element capable of realizing both a stable low-noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history, a thin film magnetic head including the MR effect element, An object of the present invention is to provide an HGA equipped with the thin film magnetic head and an HDD equipped with the HGA.

  Still another object of the present invention is to realize both a stable low-noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history by applying an appropriate bias magnetic field to the MR stack. It is to provide a magnetic recording / reproducing method.

  Before describing the present invention, terms used in the specification will be defined. In the laminated structure of the magnetic head elements formed on the element formation surface of the substrate, it is assumed that the component on the element formation surface side of the reference layer is “down” or “downward” and viewed from the reference layer. It is assumed that the component on the side opposite to the element formation surface is “upper” or “upper”. For example, “there is a shield layer on the insulating layer” means that there is a shield layer on the side opposite to the element formation surface of the insulating layer. Further, when comparing the positions of two components in one laminated structure, the closer to the element formation surface is defined as “lower”, and the farther is defined as “upper”. For example, of the two magnetic pole layers provided in the electromagnetic coil element, the “lower magnetic pole layer” means the one closer to the element formation surface.

  According to the present invention, there is provided an MR effect element including an MR laminate that senses a magnetic field and changes its own resistance value, and a magnetic path means that can apply a bias magnetic field to the MR laminate, There is provided an MR effect element comprising magnetic flux varying means capable of inducing magnetic flux of at least two magnitudes in a magnetic path means. At this time, the bias magnetic field is preferably in the track width direction. Furthermore, it is preferable that a static bias magnetic field applying means capable of applying a static bias magnetic field to the MR multilayer is provided adjacent to the MR multilayer.

  The bias magnetic field applied to the MR laminate can be changed by appropriately selecting the magnetic flux induced in the magnetic path means using the magnetic flux varying means. As a result, a sufficiently large bias magnetic field can be applied to eliminate the adverse effects of environmental temperature history, and the magnetization in the MR stack can be changed to a magnitude that can sufficiently follow the signal magnetic field. High read sensitivity can be obtained by applying a bias magnetic field. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  Here, the magnetic path means is one magnetic path layer having two magnetic poles that are near the MR laminate and are opposed to each other and can generate a bias magnetic field between them. It is preferable that the variable means is a bias coil portion formed by using one magnetic path layer as a magnetic core.

  According to such a configuration, the bias coil unit becomes an induction coil, and a magnetic flux according to the amount of current applied to the bias coil unit can be induced to the magnetic path layer. Therefore, the coil magnetic field generated between the two magnetic poles and applied to the MR laminate can be set to a desired value within a continuous range. As a result, various effects such as optimization of the bias point and initialization of the magnetization state of the MR stack can be realized.

  Further, the magnetic path means is two yoke layers each having a magnetic pole located in the vicinity of the MR laminate, and both of these magnetic poles are opposed to each other to generate a bias magnetic field between them. The magnetic flux changing means includes a hard magnetic portion and is movable, and two end portions of the magnetic flux generating portion are connected to two opposite poles of the two yoke layers. It is also preferable to include a magnetic flux generation unit driving means for connecting to each end or separating from the two ends. At this time, it is preferable that the magnetic flux generation unit driving means includes a micro electro mechanical system (MEMS) unit that moves the magnetic flux generation unit.

  Furthermore, it is also preferable that this MEMS part is provided with at least one set of parallel plate electrodes for moving the magnetic flux generating part in the direction within the layer surfaces of the two yoke layers. Furthermore, it is also preferable that the MEMS unit includes at least one comb electrode set that moves the magnetic flux generation unit in a direction within the layer surfaces of the two yoke layers or in a direction perpendicular to the layer surfaces. Furthermore, it is also preferable to include a rotary actuator that rotates the magnetic flux generator.

  According to such a configuration, by driving the MEMS portion, the magnetic flux generating portion can be connected to the yoke layer or separated from the yoke layer by a predetermined distance. Thereby, the magnetic flux according to the distance of a magnetic flux generation part and a yoke layer can be induced | guided | derived to a yoke layer. Therefore, the yoke magnetic field generated between the magnetic poles and applied to the MR stack can be set to a desired value within a continuous range. As a result, various effects such as optimization of the bias point and initialization of the magnetization state of the MR stack can be realized.

  Further, according to the present invention, there is provided a thin film magnetic head including at least one MR effect element as described above for reading and further including at least one electromagnetic coil element for writing.

  Further, according to the present invention, at least one thin-film magnetic head is provided, a lead wire for supplying power to the magnetic flux varying means, a signal wire for the MR effect element and the electromagnetic coil element described above, and this An HGA further provided with a support mechanism for supporting the thin film magnetic head is provided.

  According to the present invention, furthermore, at least one HGA is provided, and a magnetic flux control circuit for controlling power supplied to the magnetic flux varying means, and a recording / reproducing circuit for controlling read and write operations. Further provided HDDs are provided. At this time, it is preferable to include a CPU that controls the magnetic flux control circuit and the recording / reproducing circuit, and drives the magnetic flux control circuit in synchronization with the read and / or write operation.

  By using such a CPU, for example, it is possible to drive the magnetic flux varying means in accordance with the read operation and adjust the bias magnetic field applied to the MR stack to an optimum size for reading. Furthermore, various other magnetic field application operations that are linked with the read and write operations can be realized.

  Further, according to the present invention, the first bias magnetic field is applied to the MR multilayer body in the MR effect element for reading at the time of non-reading including the time of writing, and then the MR multilayer at the time of reading operation by the MR effect element. There is provided a magnetic recording / reproducing method for applying a second bias magnetic field smaller than the first bias magnetic field to a body. At this time, the first and second bias magnetic fields are preferably in the track width direction.

  First, at the time of non-reading, an adverse effect of the environmental temperature history is eliminated by applying a sufficiently large first bias magnetic field to the MR stack to stably maintain the magnetization state of the MR stack. Next, at the time of reading, a second bias magnetic field that is smaller than the first bias magnetic field and that can sufficiently follow the signal magnetic field in the MR stack is applied. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  Here, the static magnetic field generated by the static bias magnetic field applying means installed adjacent to the MR laminate is used as the first bias magnetic field, and then the coil magnetic field generated by energizing the first bias magnetic field and the induction coil It is also preferable that the second bias magnetic field is obtained by synthesizing. In this case, the static magnetic field generated by the static bias magnetic field applying unit and the coil magnetic field generated by energizing the induction coil are set so that their directions are opposite to each other, or in a direction in which the magnitude is smaller than the static magnetic field by synthesis. Will be.

  Furthermore, the static magnetic field generated by the static bias magnetic field applying means installed adjacent to the MR laminate and the magnetic flux from the magnetic flux generating part including the hard magnetic part are passed through a yoke layer magnetically connected to the magnetic flux generating part. The yoke magnetic field generated by the propagation is combined to form a first bias magnetic field, and then the magnetic flux generator is separated from the yoke layer to reduce the yoke magnetic field, and the bias magnetic field and the reduced yoke magnetic field are It is also preferable that the second bias magnetic field is synthesized.

  According to the present invention, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail, referring an accompanying drawing. In the drawings, the same 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 an HDD according to the present invention, and FIG. 2 is a perspective view showing an embodiment of an HGA according to the present invention. FIG. 3 is a perspective view showing a thin film magnetic head (slider) attached to the tip of the HGA in the embodiment of FIG.

  In FIG. 1, 10 is a plurality of magnetic disks rotating around the rotation axis of the spindle motor 11, 12 is an assembly carriage device for positioning a thin film magnetic head (slider) 21 on a track, and 13 is this thin film. A recording / reproducing and magnetic flux control circuit for controlling writing and reading operations of the magnetic head and controlling a magnetic flux for bias described later are shown.

  The assembly carriage device 12 is provided with a plurality of drive arms 14. These drive arms 14 can be angularly swung about a pivot bearing shaft 16 by a voice coil motor (VCM) 15 and are stacked in a direction along the shaft 16. An HGA 17 is attached to the tip of each drive arm 14. Each HGA 17 is provided with a thin film magnetic head (slider) 21 so as to face the surface of each magnetic disk 10. A single magnetic disk 10, drive arm 14, HGA 17, and slider 21 may be provided.

  As shown in FIG. 2, the HGA 17 is configured by fixing a slider 21 having a magnetic head element to the tip of a suspension 20 and electrically connecting one end of a wiring member 25 to a terminal electrode of the slider 21. The

  The suspension 20 includes a load beam 22, a flexure 23 having elasticity fixedly supported on the load beam 22, a base plate 24 provided at the base of the load beam 22, and a lead conductor provided on the flexure 23. And the wiring member 25 which consists of the connection pad electrically connected to the both ends is comprised mainly. Although not shown, a head driving IC chip may be mounted in the middle of the suspension 20.

  As shown in FIG. 3, the thin film magnetic head (slider) 21 in this embodiment includes an ABS 30 processed to obtain an appropriate flying height, a magnetic head element 32 formed on an element forming surface 31, and an element Four signal terminal electrodes 36 and two drive terminal electrodes 37 exposed from the layer surface of the covering layer 38 formed on the formation surface 31 are provided. Here, the magnetic head element 32 includes an MR effect element 33 for reading and an electromagnetic coil element 34 for writing. Here, the four signal terminal electrodes 36 are connected to the MR effect element 33 and the electromagnetic coil element 34, and the two drive terminal electrodes 37 are connected to a magnetic flux varying means (described later) installed in the MR effect element. Has been.

  The two drive terminal electrodes 37 are arranged on both sides of the group of four signal terminal electrodes 36, respectively. This is an arrangement capable of preventing crosstalk between the wiring of the MR effect element 33 and the wiring of the electromagnetic coil element 34 as described in JP-A-2004-234792. However, when crosstalk is allowed, the two drive terminal electrodes 37 may be disposed at a position between any of the four signal terminal electrodes 36, for example. In addition, the number of these terminal electrodes is not limited to the form of FIG. In FIG. 3, the number of terminal electrodes is six. However, for example, the number of electrodes may be five and the ground may be grounded to the slider substrate.

  4 is a plan view of the MR effect element 33 in the embodiment of FIG. 3 as seen through from the element forming surface 31 side.

  According to FIG. 4, the MR multilayer 332 is arranged on the element formation surface so that the end side is in contact with the head end surface 300 on the same side as the ABS. The MR multilayer 332 is a main part of the MR effect element 33 that senses a signal magnetic field and changes its own resistance value according to the magnetic field strength to cause an output change. A bias hard magnetic layer 335 is disposed adjacent to both ends of the MR multilayer 332 in the track width direction. The bias hard magnetic layer 335 is a means for applying a static bias magnetic field and applies a hard bias magnetic field 42 in the track width direction to the MR stack 332 by a static magnetic field from a ferromagnetic material, and is sufficiently large with respect to the sensed signal magnetic field. This contributes to the formation of a linear output having a thickness.

  The magnetic path layer 40 is located slightly above the MR multilayer 332 and the bias hard magnetic layer 335, but its two ends 40a are in the vicinity of the respective ends of the MR multilayer 332 in the track width direction. Is located. The bias coil section 41 includes a bias coil layer formed with the magnetic path layer 40 as a magnetic core, and can induce a magnetic flux in the magnetic path layer 40 when energized. By induction of this magnetic flux, a magnetic field is generated between the two ends 40 a of the magnetic path layer 40, and as a result, the coil magnetic field 43 can be applied to the MR multilayer 332. Here, the magnetic path layer 40 is a magnetic path means to the MR effect element 332.

  With such a configuration, the bias magnetic field applied to the MR multilayer 332 can be changed by adjusting the energization to the bias coil unit 41. For example, when not energized, as described above, the MR multilayer 332 is applied with the hard bias magnetic field 42 as the first bias magnetic field. Next, when the bias coil unit 41 is energized, a combined magnetic field 44 of the hard bias magnetic field 42 and the coil magnetic field 43 is applied to the MR multilayer 332 as the second bias magnetic field. Here, in the figure, the second bias magnetic field is changed to the first bias magnetic field by selecting the direction of current application to the bias coil section and making the directions of the coil magnetic field 43 and the hard bias magnetic field 42 opposite to each other. It is set to be smaller. The bias coil unit 41 serves as a magnetic flux varying means for changing the magnetic flux induced in the magnetic path layer 40 in order to change the bias magnetic field.

  As described above, according to this embodiment, the bias magnetic field applied to the MR stack can be changed and adjusted as necessary. Therefore, for example, as will be described later, a sufficiently large first bias magnetic field is applied during non-writing to stably maintain the magnetization state of the MR multilayer, and during reading, the first bias magnetic field is higher than the first bias magnetic field. It is possible to apply a second bias magnetic field that is small and allows the magnetization of the magnetization free layer in the MR stack to sufficiently follow the signal magnetic field. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  Furthermore, by selecting the value of the current flowing through the bias coil section, it is possible to apply various magnitudes of magnetic fields to the MR stack, not limited to the first and second bias magnetic fields. Therefore, for example, it is possible to realize an optimum bias point as the MR effect element by finely adjusting the current value or by adjusting the feedback from the reproduction output. In addition, by increasing the applied magnetic field sufficiently, when the magnetic domain state of the magnetization free layer is disturbed and noise increases, the magnetization state of the magnetization free layer is prevented from adversely affecting the magnetization of the magnetization fixed layer. Can also be initialized.

  In this embodiment, the magnetic path layer has two ends serving as magnetic poles. However, if the bias magnetic field can be reliably applied to the MR multilayer, one magnetic pole may be used. . Further, as a means for applying a static bias magnetic field to the MR laminate, an in-stack bias laminate may be used instead of the bias hard magnetic layer. The in-stack bias stack has a structure in which a nonmagnetic layer, a ferromagnetic layer, and an antiferromagnetic layer are sequentially stacked on a magnetization free layer, and magnetization (in the track width direction) is caused by the antiferromagnetic layer. The magnetization free layer is biased by a static magnetic field generated from the fixed ferromagnetic layer.

  5A is a cross-sectional view taken along the line CC of FIG. 4 in the MR effect element 33 of the embodiment of FIG. 4, and FIG. 5B is a cross-sectional view of the MR effect element 33 of the embodiment of FIG. 4 is a cross-sectional view taken along the line D-D in FIG. 4, and FIG. 5C is a cross-sectional view taken along the line A-A in FIG. 3 for explaining the terminal electrode portion in the embodiment of FIG. 3.

  According to FIG. 5A, a lower shield layer 330 is formed on a slider substrate and an insulating layer (not shown). On the lower shield layer 330, a magnetization fixed layer 3323, a nonmagnetic intermediate layer 3324, and a magnetization free layer 3325 are sequentially formed to constitute the MR multilayer 332. An upper shield layer 334 is further formed on the MR multilayer 332. The MR laminated body 332 has a current-in-plane (CIP (Current In Plain)) giant magnetoresistance (GMR (Giant Magneto Resistive)) type, a vertical conduction type (CPP (Current Perpendicular to Plain)) GMR type, or a tunnel magnetoresistance. Any of (TMR (Tunnel Magneto Resistive)) type may be used. Here, the MR effect element 33 becomes a CIP-GMR effect element, a CPP-GMR effect element, or a TMR effect element corresponding to each case of the MR multilayer 332. In the present embodiment, the MR multilayer 332 is a CPP-GMR type or TMR type. In this case, the upper and lower shield layers 334 and 330 serve to prevent the MR multilayer 332 from receiving an external magnetic field that causes noise, and also function as upper and lower electrodes for flowing a sense current to the MR multilayer 332. To do.

  Here, at the time of reading, it is the magnetization free layer 3325 that senses the signal magnetic field, and the magnetization direction of the magnetization free layer 3325 changes according to the signal magnetic field. At this time, the MR multilayer 332 exhibits a resistance value corresponding to an angle formed by the magnetization of the magnetization free layer 3325 and the magnetization fixed layer 3323, and as a result, a reproduction output voltage corresponding to the signal magnetic field is obtained. It will be.

  Further, a bias hard magnetic layer 335 is formed adjacent to both ends of the MR multilayer 332 in the track width direction. Furthermore, a magnetic path layer 40 is formed on the bias hard magnetic layer 335 via a second MR insulating layer 51 described later. With such a configuration, a coil magnetic field in the track width direction generated between the two ends 40 a of the magnetic path layer 40 can be applied to the magnetization free layer 3325.

  In addition, the magnetic path layer 40 is, for example, an alloy composed of any two or three of Ni, Fe, and Co having a thickness of about 0.1 μm to about 5.0 μm, or a predetermined element mainly composed of these. Can be formed from an alloy to which is added.

  According to FIG. 5B, a plurality of first bias coil layers 410, a first bias coil insulating layer 412, and a second MR insulating layer 51 are formed on a first MR insulating layer 50 described later. The magnetic path layer 40, the third MR insulating layer 52, the plurality of second bias coil layers 411, the second bias coil insulating layer 413, and the fourth MR insulating layer 53 are sequentially stacked. Has been. Here, although not shown in the drawings, the first bias coil layers 410 and the second bias coil layers 411 are electrically connected in series with their end portions alternately overlapped with each other. That is, the plurality of first and second bias coil layers 410 and 411 together with the first and second bias coil insulating layers 412 and 413 constitute a bias coil section 41 wound around the magnetic path layer 40. is doing. Note that the number of turns of the coil layer of the bias coil unit 41 is not limited to the number of turns shown in FIG.

  The first and second bias coil layers 410 and 411 can be formed of, for example, Cu having a thickness of about 0.5 μm to about 3 μm. The first and second bias coil insulating layers 412 and 413 can be formed of a thermally cured resist layer having a thickness of about 0.1 μm to about 5 μm, for example.

  In FIG. 5C, lead electrodes 410a and 411a drawn from the bias coil portion 41 appear in the cross section shown in FIG. Here, the extraction electrodes 410a and 411a are electrically connected to the respective ends of the coil winding formed from the first and second bias coil layers 410 and 411, respectively. Conductive electrode film members 54 and 57 are formed on the extraction electrodes 410a and 411a, respectively. On the electrode film members 54 and 57, bumps 55 and 58 extending upward are formed by electroplating using the electrode film members 54 and 57 as electrodes. The electrode film members 54 and 57 and the bumps 55 and 58 can be formed of a conductive material such as Cu. The electrode film members 54 and 57 have a thickness of about 10 nm to about 200 nm, and the bumps 55 and 58 have a thickness of about 5 μm to about 30 μm.

  The upper ends of the bumps 55 and 58 are exposed from the coating layer 38, and pads 56 and 59 are provided on these upper ends, respectively. A current is supplied to the bias coil unit 41 through the pads 56 and 59. Similarly, the MR effect element 33 and the electromagnetic coil element 34 are connected to the signal terminal electrode 36 (FIG. 3), but these connection structures are not shown for the sake of easy viewing.

  6 is a cross-sectional view taken along the line BB of FIG. 3 showing the configuration of the magnetic head element 32 for longitudinal magnetic recording as an embodiment of the magnetic head element of FIG. Note that the number of turns of the write coil layer for writing in FIG. 6 is shown to be smaller than the number of turns in FIG. 3 in order to simplify the drawing. The write coil layer may be one layer, two layers or more, or a helical coil.

  In FIG. 6, reference numeral 210 denotes a slider substrate which has an ABS 30 facing the surface of the magnetic disk and floats with a predetermined flying height hydrodynamically on the rotating magnetic disk surface during writing and reading operations. An MR effect element 33 for reading, an electromagnetic coil element 34 for writing, and, for example, a magnetic guide as a magnetic path means are formed on the element forming surface 31 which is one side surface when the ABS 30 of the slider substrate 210 is the bottom surface. A path layer 40 and, for example, a bias coil layer 41 as a magnetic flux varying means are mainly formed.

  As described above, the MR effect element 33 includes the MR multilayer 332, the upper and lower shield layers 334 and 330 disposed at positions sandwiching the multilayer, and the bias hard magnetic layer 335 for applying a hard bias magnetic field. And. In this embodiment, the MR multilayer 332 is a CPP-GMR type or a TMR type. However, when the MR multilayer 332 is a CIP-GMR type, each of the upper and lower shield layers 334 and 330 and the MR multilayer 332 are provided. Between the upper and lower shield gap layers for insulation. Further, an MR lead conductor layer for supplying a sense current to the MR multilayer 332 and taking out a reproduction output is formed.

  The electromagnetic coil element 34 is for longitudinal magnetic recording in the present embodiment, and includes a lower magnetic pole layer 340, a gap layer 341, a write coil layer 343, and an upper magnetic pole layer 345. The lower magnetic pole layer 340 and the upper magnetic pole layer 345 form a magnetic flux path of the magnetic flux induced by the write coil layer 343, and the end portions on the head end surface 300 side of the gap layer 341 are sandwiched between the end portions 340a and 345a. Yes. Writing to the magnetic disk for longitudinal magnetic recording is performed by the leakage magnetic field from the end of the gap layer 341. Note that the ends of the lower magnetic pole layer 340 and the upper magnetic pole layer 345 on the magnetic disk side reach the head end surface 300, but the head end surface 300 is coated with diamond-like carbon (DLC) or the like as an extremely thin protective film. It has been subjected.

  Next, the configuration of the magnetic head element 32 will be described in more detail with reference to FIG.

For example, an insulating layer 60 made of Al ₂ O ₃ or the like and having a thickness of about 0.05 to 10 μm is formed on the slider substrate 210 made of AlTiC (Al ₂ O ₃ —TiC) or the like. On this insulating layer 60, a lower shield layer 330 having a thickness of about 0.3 to 3 μm made of, for example, NiFe, NiFeCo, CoFe, FeN, or FeZrN is formed. A hard magnetic layer 335 is formed.

Further, first and second MR insulating layers 50 and 51 made of, for example, Al ₂ O ₃ are formed so as to surround the MR multilayer 332 and cover the bias hard magnetic layer 335. On the MR insulating layers 50 and 51, a bias coil portion 41 and a magnetic path layer 40 are formed. Further, a third MR insulating layer 52 made of, for example, Al ₂ O ₃ or the like is formed on the magnetic path layer 40. Further, on the bias coil portion 41 and the third MR insulating layer 52, for example, Al _A fourth MR insulating layer 53 made of ₂ O ₃ or the like is formed.

On the fourth MR insulating layer 53, an upper shield layer 334 made of, for example, NiFe, NiFeCo, CoFe, FeN, FeZrN or the like and having a thickness of about 0.3 to 4 μm is formed. Next, an inter-element insulating layer 61 made of Al ₂ O ₃ or the like and having a thickness of about 0.1 to 2.0 μm is formed on the upper shield layer 334.

A lower magnetic pole layer 340 having a thickness of about 0.3 to 3 μm made of, for example, NiFe, NiFeCo, CoFe, FeN, or FeZrN is formed on the inter-element insulating layer 61. Further, on the lower magnetic pole layer 340, For example, a gap layer 341 made of Al ₂ O ₃ or DLC having a thickness of about 0.01 to 0.5 μm is formed. Further, on the gap layer 341, a thickness 0 made of, for example, a heat-cured resist layer or the like is formed. A first coil insulating layer 3440 having a thickness of about 1 to 5 μm is formed. On the first coil insulating layer 3440, a write coil layer 343 made of, for example, Cu or the like and having a thickness of about 0.5 to 3 μm is formed. Further, for example, thermosetting is performed so as to cover the write coil layer 343. A second coil insulating layer 3441 having a thickness of about 0.1 to 5 μm is formed from the resist layer and the like.

Further, an upper magnetic pole layer 345 made of, for example, NiFe, NiFeCo, CoFe, FeN, FeZrN or the like and having a thickness of about 0.5 to 5 μm is formed so as to cover the second coil insulating layer 3441. Further, a covering layer 38 made of, for example, Al ₂ O ₃ is formed so as to cover the MR effect element 33 and the electromagnetic coil element 34.

  7 is a cross-sectional view taken along line BB of FIG. 3 showing the configuration of a magnetic head element 32 ′ for perpendicular magnetic recording as another embodiment of the magnetic head element of FIG. In FIG. 6, the same or corresponding components as those of the magnetic head element 32 for longitudinal magnetic recording in FIG. 6 are denoted by the same reference numerals as those in FIG. The explanation is omitted.

  In FIG. 7, the electromagnetic coil element 34 ′ is for perpendicular magnetic recording in this embodiment, and includes a main magnetic pole layer 340 ′, an auxiliary magnetic pole layer 345 ′, and a writing coil layer 343 ′. The main magnetic pole layer 340 ′ is a magnetic path for guiding the magnetic flux induced by the write coil layer 343 ′ while converging it to the perpendicular magnetic recording layer of the magnetic disk on which writing is performed. It is composed of a magnetic pole auxiliary layer 3401 ′. Here, the length (thickness) in the layer thickness direction of the end 340a ′ on the head end surface 300 side of the main magnetic pole layer 340 ′ corresponds to the layer thickness of only the main magnetic pole main layer 3400 ′, and is small. Yes. As a result, a fine write magnetic field corresponding to higher recording density can be generated.

  The end of the auxiliary magnetic pole layer 345 ′ on the head end surface 300 side is a trailing shield part 3450 ′ having a wider layer cross section than the other part of the auxiliary magnetic pole layer 345 ′. By providing the trailing shield part 3450 ′, the magnetic field gradient becomes steeper between the end part 3450a ′ of the trailing shield part 3450 ′ and the end part 340a ′ of the main magnetic pole layer 340 ′. As a result, the jitter of the signal output is reduced, and the error rate at the time of reading can be reduced.

  Here, the configuration of the magnetic head element 32 'will be described in more detail with reference to FIG. Components that are the same as or correspond to those of the magnetic head element 32 shown in FIG.

  On the formed inter-element insulating layer 61, for example, a thickness of 0 made of an alloy composed of any two or three of Ni, Fe and Co, or an alloy to which a predetermined element is added as a main component thereof, etc. A main magnetic pole main layer 3400 ′ of about 0.01 to 0.5 μm, an alloy composed of any two or three of, for example, Ni, Fe and Co, or an alloy to which a predetermined element is added as a main component thereof And a main magnetic pole auxiliary layer 3401 ′ having a thickness of about 0.5 to 3 μm.

On the main magnetic pole auxiliary layer 3401 ′, a gap layer 341 ′ having a thickness of about 0.01 to 0.5 μm made of, for example, Al ₂ O ₃ or DLC is formed. Further, on the gap layer 341 ′, for example, A first coil insulating layer 3440 ′ having a thickness of about 0.1 to 5 μm made of a heat-cured resist layer or the like is formed. On the first coil insulating layer 3440 ′, a write coil layer 343 ′ made of, for example, Cu or the like and having a thickness of about 0.5 to 3 μm is formed. Further, the write coil layer 343 ′ is covered so as to cover the write coil layer 343 ′. For example, a second coil insulating layer 3441 ′ having a thickness of about 0.1 to 5 μm made of a heat-cured resist layer or the like is formed.

Further, for example, an alloy composed of any two or three of Ni, Fe and Co, or an alloy to which a predetermined element is added as a main component so as to cover the second coil insulating layer 3441 ′. An auxiliary magnetic pole layer 345 ′ having a thickness of about 0.5 to 5 μm is formed. Further, a covering layer 43 made of, for example, Al ₂ O ₃ is formed so as to cover the MR effect element 33, the electromagnetic coil element 34 ′, and the like.

  FIG. 8 is a schematic diagram for explaining the configuration of another embodiment of the magnetic guide path means and the magnetic flux varying means of the present invention.

  According to FIG. 8 (A), in this embodiment, the magnetic path means is composed of two yoke layers 80, and the magnetic flux variable means is the magnetic flux generator 81 and the MEMS that is the magnetic flux generator drive means. Part 82. Here, the two yoke layers 80 are located slightly above the MR multilayer 332 and the bias hard magnetic layer 335, but the respective ends 80a of the MR multilayer 332 at both ends in the track width direction. Located in the vicinity. The magnetic flux generation unit 81 includes a hard magnetic portion 810 and two contact portions 811 connected to both ends of the hard magnetic portion 810 in the track width direction. The magnetic flux generator 81 is in contact with the respective ends of the two yoke layers 80 and magnetically connected at the two contact portions 811, but can be moved by the MEMS portion 82. Yes.

  The MEMS unit 82 serves as a magnetic flux generation unit driving unit that moves the magnetic flux generation unit 81. The MEMS unit 82 is fixed to the magnetic flux generation unit 81 and is movable, and includes two first comb electrodes 820 and 822, The wiring portion 824 includes two second comb-shaped electrodes 821 and 823 which have and are fixed to comb teeth provided at positions where the comb-tooth electrodes mesh with the comb teeth. The wiring part 824 electrically connects the first and second comb-tooth electrodes 820 and 821 and the first and second comb-tooth electrodes 822 and 823 in parallel, and a voltage for driving them simultaneously. Can be applied. Note that the terminals 824a and 824b of the wiring portion are connected to the drive terminal electrode 37 (FIG. 3), respectively.

  In the state of FIG. 8A, the two yoke layers 80 and the magnetic flux generator 81 are magnetically connected, so that the magnetic field from the hard magnetic portion 810 causes a yoke magnetic field 83 between the ends 80a of the yoke layer 80. Occurs. Here, the direction of the yoke magnetic field 83 is aligned with the direction of the hard bias magnetic field 84 by the bias hard magnetic layer 335 by selecting the direction of magnetization of the hard magnetic portion 810. Accordingly, a larger combined magnetic field of the yoke magnetic field 83 and the hard bias magnetic field 84 by the bias hard magnetic layer 335 is applied to the MR multilayer 332 as the first bias magnetic field 85.

Next, as shown in FIG. 8B, appropriate voltages are applied between the first and second comb electrodes 820 and 821 and between the first and second comb electrodes 822 and 823, respectively. When applied, the first comb electrode portions 820 and 822 are attracted to the fixed first and second comb electrode portions 822 and 823 by Coulomb force, respectively. As a result, the magnetic flux generating section 81, by moving in the direction of arrow 86 in a direction of the layer surface of the yoke layer 80, a yoke layer from the yoke layer 80 spaced apart by a sufficient distance D _Y 80 and magnetically Almost cut off. As a result, a second bias magnetic field 87 that is substantially the magnitude of the hard bias magnetic field 84 and smaller than the first bias magnetic field is applied to the MR multilayer 332. Therefore, for example, as will be described later, a sufficiently large first bias magnetic field is applied during non-writing to stably maintain the magnetization state of the MR multilayer, and during reading, the first bias magnetic field is higher than the first bias magnetic field. It is possible to apply a second bias magnetic field that is small and allows the magnetization of the magnetization free layer to sufficiently follow the signal magnetic field. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

Further, by selecting the voltage applied to the MEMS unit 82, by adjusting the distance D _Y between the yoke layer 80 and the magnetic flux generating section 81 is not limited to the first and second bias magnetic fields of various sizes Can be applied to the MR stack. Therefore, for example, an optimum bias point as an MR effect element can be realized, or the magnetization state of the magnetization free layer can be initialized.

  In this embodiment, two yoke layers are provided. However, one yoke layer may be used as long as a bias magnetic field can be reliably applied to the MR multilayer. Furthermore, in the present embodiment, two sets of the first and second comb electrodes are provided, but if only one magnetic flux generator can be stably moved as necessary, only one may be provided. Three or more may be provided. Furthermore, as a means for applying a static bias magnetic field to the MR laminate, an in-stack bias laminate may be used instead of the bias hard magnetic layer.

  FIG. 9 is a schematic diagram for explaining a change mode of the MEMS unit 82.

According to FIG. 9A, the MEMS portion 82 ′ is fixed to the magnetic flux generating portion 81 ′ and is movable in the direction of the double layer arrow 90 in the direction of the layer surface of the yoke layer 80 ′. An electrode 820 ′ and a second flat plate electrode 821 ′ facing and fixed to the first flat plate electrode 820 ′ are provided. Here, by applying a voltage to both electrodes, the magnetic flux generator 81 ′ can be moved in the direction of the arrow 90 in the direction in the layer surface of the yoke layer 80 ′ by Coulomb force. As a result, it is possible to adjust the bias magnetic field applied to the MR stack by separating the magnetic flux generator 81 ′ from the yoke layer 80 ′ by the distance D _Y ′.

According to FIG. 9B, the MEMS section 82 ″ is fixed to the magnetic flux generating section 81 ″, is perpendicular to the layer surface of the yoke layer 80 ″, and is movable in the direction of the double arrow 92. And a second comb electrode 821 ″ having a comb tooth provided at a position that meshes with the comb teeth of the first comb electrode 820 ″ and fixed. ing. Here, by applying a voltage to both electrodes, the magnetic flux generator 81 ″ can be moved in the direction of the arrow 93 perpendicular to the layer surface of the yoke layer 80 ″ by the Coulomb force. As a result, it is possible to adjust the bias magnetic field applied to the MR stack by separating the magnetic flux generating portion 81 ″ from the yoke layer 80 ″ by the interval D _{Y ″} .

  Also in the above two modifications, the number of the first and second electrode sets may be one, or two or more. In the case of a plurality, it is preferable that these sets of electrode portions are connected in parallel to each other.

  FIG. 10 is a schematic diagram for explaining the configuration of still another embodiment of the magnetic guide path means and the magnetic flux varying means of the present invention.

  FIG. 10A is a principle diagram of the rotary actuator 94 used in the present embodiment. According to the figure, the rotary actuator 94 surrounds the rotor 940 in a position that can be opposed to each pole of the rotor 940 having two or more poles that can rotate about its center. And a stator 941 having two or more poles arranged in this manner. When a voltage is applied between the rotor 940 and the stator 941, torque is generated by the Coulomb force, and the rotor 940 rotates. Here, the rotor 940 and the stator 941 may have two or more poles. For example, the rotor 940 may have four poles and the stator 941 may have three poles. In any case, the rotation angle of the rotor can be selected by applying a predetermined voltage pattern.

  According to FIG. 10B, the hard magnetic portion 96 corresponding to the magnetic flux generating portion in the present embodiment is fixed to the rotor 940. Both ends of the hard magnetic portion 96 are in contact with or adjacent to each end of the yoke layer 95 in a state where no voltage is applied to the rotary actuator 94, and are magnetically connected. Yes. In this case, a combined magnetic field of the magnetic field generated by the magnetic flux from the hard magnetic part 96 and the bias magnetic field from the static bias magnetic field applying means adjacent to the MR multilayer is applied to the MR multilayer as the first bias magnetic field.

  Next, by applying a predetermined voltage pattern to the rotary actuator 94 corresponding to the MEMS unit that is the magnetic flux generating unit driving means in the present embodiment, the hard magnetic unit 96 is moved to 90 as shown in FIG. Rotate degrees. Due to this rotation, both ends of the hard magnetic portion 96 and the respective ends of the yoke layer are separated from each other, so that the magnetic flux from the hard magnetic portion hardly reaches the yoke layer. As a result, the bias magnetic field from the static bias magnetic field applying means adjacent to the MR multilayer is applied to the MR multilayer as a second bias magnetic field that is smaller than the first bias magnetic field. As a result, for example, as described later, a sufficiently large first bias magnetic field is applied during non-writing to stably maintain the magnetization state of the MR multilayer, and during reading, the first bias magnetic field is The second bias magnetic field can be applied so that the magnetization of the magnetization free layer can sufficiently follow the signal magnetic field. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  Further, by selecting a voltage pattern to be applied to the rotary actuator 94, the rotation angle of the rotor 940 is adjusted, and not only the first and second bias magnetic fields but also various magnetic fields are applied to the MR laminate. Can be applied. Therefore, for example, an optimum bias point as an MR effect element can be realized, or the magnetization state of the magnetization free layer can be initialized.

  In the present embodiment, two yoke layers are provided, but one yoke layer may be used as long as a bias magnetic field can be reliably applied to the MR multilayer. Furthermore, a yoke layer having two or more branches that are arranged at a position surrounding the rotating hard magnetic portion 96 may be provided.

  As described above, the embodiment in which the MEMS unit as described in FIGS. 8 to 10 is used as the magnetic flux generation unit driving means or the modified embodiment is compared with the embodiment in which the bias coil unit is provided as the magnetic flux varying unit as shown in FIG. Thus, there is an advantage that the power consumption of the magnetic flux varying means can be considerably reduced. In particular, when operating the magnetic flux varying means at the time of reading, it is not necessary to place a heavy burden on the preamplifier unit that supplies the power for reading.

Note that the electrodes and the like of these MEMS parts can be processed and formed using, for example, Si or the like as a material, using a photolithography method, a dry etching method, or the like. In addition, the conductive portion such as the wiring portion can be formed using, for example, Al formed by an electron beam evaporation method, a sputtering method, or the like. Furthermore, the insulating portion can be formed using, for example, a silicon oxide (SiO ₂ ) film formed by a thermal oxidation method.

  FIG. 11 is a block diagram showing the circuit configuration of the HDD recording / reproducing and magnetic flux control circuit 13 in the embodiment of FIG.

  In FIG. 1, the recording / reproducing and magnetic flux control circuit 13 includes a CPU 1100, a recording / reproducing channel 1101, and a preamplifier unit 1102. The recording data output from the recording / reproducing channel 1101 is supplied to the preamplifier unit 1102. The preamplifier unit 1102 receives the recording control signal output from the CPU 1100 by the write gate 1103, and supplies the recording data to the electromagnetic coil element 34 only when the recording control signal instructs a writing operation. At this time, the preamplifier unit 1102 sends a write current to the coil layer 343 in accordance with the recording data, and recording is performed on the magnetic disk.

  Also, a constant current flows from the preamplifier unit 1102 to the MR multilayer 332 only when the reproduction control signal output from the CPU 1100 and received by the read gate 1104 instructs a read operation. At this time, the reproduction signal received by the preamplifier unit 1102 from the MR effect element 33 is amplified and demodulated and output to the recording / reproduction channel 1101 as reproduction data.

  The preamplifier unit 1102 receives a magnetic flux control signal output from the CPU 1100. When this magnetic flux control signal is an on operation instruction, a current or voltage is applied to the magnetic flux varying means 41, and a magnetic field for bias is applied to the MR multilayer 332 from both ends of the magnetic path means 40. The current value or voltage value at this time is controlled to a value corresponding to the magnetic flux control signal.

  In FIG. 11, the preamplifier unit 1102 includes both a recording / reproducing circuit and a magnetic flux control circuit. Here, the CPU 1100 controls both of these circuits, and can drive the magnetic flux control circuit in synchronization with the read and / or write operations.

  Further, it is clear that the circuit configuration of the recording / reproducing and magnetic flux control circuit 13 is not limited to that shown in FIG. For example, the recording / reproducing circuit and the magnetic flux control circuit may be provided independently, or power may be supplied to the magnetic flux changing means using an independent power source.

  FIG. 12 is a time chart for explaining two embodiments of the magnetic recording / reproducing method according to the present invention.

  According to FIG. 12A, first, power is not applied to the magnetic flux varying means during non-reading including writing when the write gate is in the ON state. Next, at the same time as or immediately before the read operation by the MR effect element is started when the read gate is turned on, power is supplied to the magnetic flux varying means. Further, at the same time as or immediately after the read operation by the MR effect element is completed when the read gate is turned off, the application of power to the magnetic flux changing means is completed.

  Here, when electric power is applied to the magnetic flux varying means, a magnetic field is applied to the MR multilayer via the magnetic path means. At this time, as shown in FIGS. 4 and 8 to 10, the direction of the magnetic field is opposite to the direction of the static magnetic field by the static bias magnetic field applying means installed adjacent to the MR laminate. Is set. As a result, first, at the time of non-reading, a sufficiently large first bias magnetic field by the static bias magnetic field applying means can be applied to the MR multilayer to stably maintain the magnetization state of the MR multilayer. Next, at the time of reading, it is possible to apply a second bias magnetic field that is smaller than the first bias magnetic field by a magnetic field generated by applying power and that the magnetization of the magnetization free layer can sufficiently follow the signal magnetic field. Become. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  In this case, the magnetic flux varying means consumes electric power only during reading, and does not place a heavy burden on the preamplifier section as a power source.

  Next, another embodiment will be described with reference to FIG. In this embodiment, the direction of the magnetic field generated in the MR multilayer when power is supplied to the magnetic flux varying means is opposite to that described with reference to FIG. Set to align with the direction of.

  Under such a setting, power is supplied to the magnetic flux varying means from a predetermined time point during the writing operation in which the write gate is in the ON state or after the end of the writing operation. Further, at the same time as or immediately before the read operation by the MR effect element is started when the read gate is turned on, the application of power to the magnetic flux varying means is completed.

  During the write operation, in particular, Joule heat from the write coil layer propagates to the MR multilayer, and the temperature of the MR multilayer rises. During this time, in order to avoid unnecessary power consumption, no power is supplied to the magnetic flux varying means. As a result, the first bias magnetic field by the static bias magnetic field applying means is applied to the MR multilayer. Next, in a situation where such a temperature history has passed, a second bias magnetic field that is larger than the first bias magnetic field by the amount of magnetic field generated by applying power is applied to the MR stack before or after the end of the write operation. Thus, the magnetization state of the MR stack is stabilized. Thereafter, at the same time as the start of reading or immediately before the start of the reading, the power supply to the magnetic flux varying means is terminated. As a result, the first first bias magnetic field that allows the magnetization of the magnetization free layer to sufficiently follow the signal magnetic field is applied to the MR stack. As a result, it is possible to achieve both a stable low noise reproduction output and high reproduction sensitivity that are not affected by the environmental temperature history.

  In this case, the magnetic flux changing means consumes power only for a predetermined time before the reading operation, and setting the predetermined time as small as possible avoids placing a heavy burden on the preamplifier unit as a power source. Is done.

  In the embodiment of FIG. 12B, the magnetic flux changing means is powered on at a predetermined time during the writing operation or immediately after the end of the writing operation. As a result, it is also possible to use the detection result of the environmental temperature in the HDD or the temperature of the thin film magnetic head or MR effect element. That is, when a predetermined temperature or temperature history is recognized, an instruction to turn on the power is generated. In this case, temperature detection can be performed by installing a temperature sensor near each object. Further, when the MR effect element is a GMR effect element, the temperature can be detected by monitoring the resistance value of the GMR element instead of the temperature sensor.

  The magnetic recording / reproducing method described above is not possible until at least two bias magnetic fields can be applied to the MR multilayer body at an appropriate timing in accordance with a read or write operation. Here, even if any embodiment or modification of the thin film magnetic head of the present invention is used, the bias magnetic field generated from the magnetic path means can be freely changed by applying power to the magnetic flux varying means. As a result, the magnetic recording / reproducing method described above can be realized.

  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 an HDD according to the present invention. It is a perspective view which shows one Embodiment of HGA by this invention. It is a perspective view which shows the thin film magnetic head with which the front-end | tip part of HGA in the embodiment of FIG. 2 is mounted | worn. FIG. 4 is a plan view of the MR effect element in the embodiment of FIG. 3 as seen through from the element formation surface side. 4 is a cross-sectional view taken along line CC and DD in FIG. 4, and a cross-sectional view taken along line AA in FIG. 3 for explaining the terminal electrode portion in the embodiment in FIG. It is. FIG. 4 is a cross-sectional view taken along the line B-B in FIG. 3 showing the configuration of the magnetic head element for longitudinal magnetic recording as one embodiment of the magnetic head element in FIG. 3. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3 showing a configuration of a magnetic head element for perpendicular magnetic recording as another embodiment of the magnetic head element in FIG. 3. It is the schematic for demonstrating the structure of other embodiment in the magnetic path means and magnetic flux variable means of this invention. It is the schematic for demonstrating the change aspect of a MEMS part. It is the schematic for demonstrating the structure of other embodiment in the magnetic path means and magnetic flux variable means of this invention. FIG. 2 is a block diagram showing a circuit configuration of an HDD recording / reproducing and magnetic flux control circuit in the embodiment of FIG. 1. It is a time chart explaining two embodiment of the magnetic recording / reproducing method by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic disk 11 Spindle motor 12 Assembly carriage apparatus 13 Recording / reproducing and magnetic flux control circuit 14 Drive arm 15 VCM
16 Pivot bearing shaft 17 HGA
20 Suspension 21 Slider 210 Slider substrate 22 Load beam 23 Flexure 24 Base plate 25 Wiring member 30 ABS
DESCRIPTION OF SYMBOLS 300 Head end surface 31 Element formation surface 32 Magnetic head element 33 MR effect element 330 Lower shield layer 332 MR laminated body 3323 Magnetization fixed layer 3324 Nonmagnetic intermediate layer 3325 Magnetization free layer 334 Upper shield layer 335 Bias hard magnetic layer 34 Electromagnetic coil element 340 Lower magnetic pole layer 340 'Main magnetic pole layer 340a, 340a', 345a, 3450a 'End 3400' Main magnetic pole main layer 3401 'Main magnetic pole auxiliary layer 341, 341' Gap layer 343, 343 'Writing coil layer 3440, 3440' First Coil insulation layer 3441, 3441 'Second coil insulation layer 345 Upper magnetic pole layer 345' Auxiliary magnetic pole layer 3450 'Trailing shield part 36 Signal terminal electrode 37 Drive terminal electrode 38 Cover layer 40 Conductive path layer 40a, 80a End 41 Bias coil section 41 0 first bias coil layer 410a, 411a lead electrode 411 second bias coil layer 412 first bias coil insulating layer 413 second bias coil insulating layer 42, 84 hard bias magnetic field 43 coil magnetic field 44 composite magnetic field 50 first MR insulating layer 51 Second MR insulating layer 52 Third MR insulating layer 53 Fourth MR insulating layer 54, 57 Electrode film member 55, 58 Bump 56, 59 Pad 60 Insulating layer 61 Inter-element insulating layer 80, 80 ′, 80 ″, 95 Yoke layer 81, 81 ′, 81 ″ Magnetic flux generation unit 810, 96 Hard magnetic unit 811 Contact unit 82, 82 ′, 82 ″ MEMS unit 820, 820 ′, 820 ″, 822 1 comb-tooth electrode 821, 821 ′, 821 ″, 823 2nd comb-tooth electrode 824 wiring portion 824a, 824b terminal 83 yoke Field 85 first bias magnetic field 86,91,93 arrow 87 the second bias magnetic field 90, 92 both arrows 94 rotary actuator 940 rotor 941 stator 1100 CPU
1101 Recording / reproduction channel 1102 Preamplifier section 1103 Write gate 1104 Read gate

Claims (18)

  A magnetoresistive effect element comprising a magnetoresistive laminate that senses a magnetic field and changes its own resistance value, wherein a magnetic path means that can apply a bias magnetic field to the magnetoresistive laminate, and the magnetic guide means A magnetoresistive effect element comprising: a magnetic flux varying means capable of inducing at least two magnetic fluxes.   The magnetic path means is one magnetic path layer having two magnetic poles in the vicinity of the magnetoresistive laminate and facing each other and capable of generating the bias magnetic field between each other, 2. The magnetoresistive effect element according to claim 1, wherein the magnetic flux varying means is a bias coil portion formed using the one magnetic path layer as a magnetic core.   The magnetic path means is two yoke layers each having a magnetic pole located in the vicinity of the magnetoresistive laminate, both of the magnetic poles facing each other and generating the bias magnetic field between each other The magnetic flux changing means includes a hard magnetic portion and is movable, and the two end portions of the magnetic flux generating portion are opposite to the magnetic poles of the two yoke layers. The magnetoresistive effect element according to claim 1, further comprising a magnetic flux generation unit driving means for connecting to or separating from the two ends on the side.   The magnetoresistive effect element according to claim 3, wherein the magnetic flux generation unit driving means includes a micro electro mechanical system unit that moves the magnetic flux generation unit.   5. The magnetism according to claim 4, wherein the microelectromechanical system unit includes at least one set of parallel plate electrodes for moving the magnetic flux generation unit in a direction within a layer surface of the two yoke layers. Resistive effect element.   5. The magnetism according to claim 4, wherein the micro electro mechanical system unit includes at least one set of comb-tooth electrodes for moving the magnetic flux generation unit in a direction within a layer surface of the two yoke layers. Resistive effect element.   The said micro electro mechanical system part is provided with at least 1 set of the comb-tooth electrode which moves the said magnetic flux generation | occurrence | production part in the direction perpendicular | vertical to the layer surface of the said two yoke layers. Magnetoresistive effect element.   The magnetoresistive effect element according to claim 4, wherein the micro electro mechanical system unit includes a rotary actuator that rotates the magnetic flux generation unit.   The magnetoresistive effect element according to claim 1, wherein the bias magnetic field is in a track width direction.   10. The static bias magnetic field applying means capable of applying a static bias magnetic field to the magnetoresistive laminate is provided adjacent to the magnetoresistive laminate, according to claim 1. The magnetoresistive effect element as described.   11. A thin film magnetic head comprising at least one magnetoresistive effect element according to claim 1 for reading, and further comprising at least one electromagnetic coil element for writing. .   12. A thin film magnetic head according to claim 11, comprising at least one thin film magnetic head, a lead wire for supplying electric power to the magnetic flux varying means, a signal wire for the magnetoresistive effect element and the electromagnetic coil element, and the thin film A head gimbal assembly, further comprising a support mechanism for supporting the magnetic head.   A head gimbal assembly according to claim 12, further comprising: a magnetic flux control circuit for controlling power supplied to the magnetic flux varying means; and a recording / reproducing circuit for controlling read and write operations. A magnetic disk device comprising:   14. The CPU according to claim 13, further comprising: a CPU that controls the magnetic flux control circuit and the recording / reproducing circuit, and drives the magnetic flux control circuit in synchronization with a read and / or write operation. The magnetic disk device described.   At the time of non-reading including writing, a first bias magnetic field is applied to the magnetoresistive multilayer body in the magnetoresistive effect element for reading, and then at the time of read operation by the magnetoresistive effect element, A magnetic recording / reproducing method, wherein a second bias magnetic field smaller than the first bias magnetic field is applied.   The static magnetic field generated by the static bias magnetic field applying means installed adjacent to the magnetoresistive laminate is used as the first bias magnetic field, and then the coil magnetic field generated by energizing the first bias magnetic field and the induction coil; The magnetic recording / reproducing method according to claim 15, wherein the second bias magnetic field is obtained by combining the two.   The magnetic field generated by the static bias magnetic field applying means installed adjacent to the magnetoresistive laminate and the magnetic flux from the magnetic flux generating unit including the hard magnetic unit are passed through the yoke layer magnetically connected to the magnetic flux generating unit. The yoke magnetic field generated by the propagation is combined into the first bias magnetic field, and then the magnetic flux generator is separated from the yoke layer to reduce the yoke magnetic field, thereby reducing the bias magnetic field. The magnetic recording / reproducing method according to claim 15, wherein the second bias magnetic field is obtained by combining the yoke magnetic field.   18. The magnetic recording / reproducing method according to claim 15, wherein the first and second bias magnetic fields are in a track width direction.

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