JP2005322279A - Thin-film magnetic head equipped with heater, head gimbal assembly equipped with the same, and magnetic disk device equipped with the head gimbal assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin-film magnetic head capable of maintaining signal reading capability by limiting the transmission of heat to a magneto-resistance effect layer while actively utilizing a TPTP phenomenon to prevent thermal asperity, an HGA, and a magnetic disk device. <P>SOLUTION: The thin-film magnetic head is provided with a slider having an air lubricant surface, a reading magnetic head element, a writing magnetic head element disposed in a position opposite the slider of the reading magnetic head element and having a magnetic pole part, an overcoat layer formed on the slider to cover a writing magnetic head element and the reading magnetic head element, and a heater disposed in the overcoat layer to generate heat during the operation of the reading magnetic head element or the writing magnetic head element. The heater is disposed in a position opposite the slider of the writing magnetic head element, and the end of the air lubricant surface side of the heater is disposed in a position same distant or farther from a PTR surface compared with the end of a side opposite the air lubricant surface of the magnetic pole part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thin film magnetic head including a heating element, a head gimbal assembly (HGA) including the thin film magnetic head, and a magnetic disk device including the HGA.

  In a magnetic disk device, a thin film magnetic head writes and reads signals to and from a magnetic disk rotated by a spindle motor. The thin film magnetic head has a slider fixed to the tip of the suspension of the HGA as a main body, and has an inductive electromagnetic transducer for writing and a magnetoresistive element for reading formed on the slider. At the time of signal writing or reading, the thin film magnetic head is driven to a desired position on the magnetic disk by a swingable arm.

The thin film magnetic head floats with a predetermined gap (magnetic spacing (d _MS )) hydrodynamically on the rotating magnetic disk when writing or reading a signal. In this floating state, the thin-film magnetic head writes a signal to the magnetic disk using a magnetic field generated from the dielectric electromagnetic transducer, and reads and reads the signal magnetic field from the magnetic disk by the magnetoresistive element.

  In recent years, magnetic disk devices have been increased in capacity and recording density, and accordingly, the track width of thin-film magnetic heads has become narrower. When the track width is narrowed, the signal writing ability to the magnetic disk is lowered in the write magnetic head element, and the signal reading ability from the magnetic disk is lowered in the read magnetic head element. On the other hand, the recording bits on the magnetic disk on which data has been written have been miniaturized year by year as the recording density has increased, and higher readability has been required for read magnetic head elements.

To avoid such a problem of writing and / or reading capabilities, in a recent magnetic disk devices tend to a smaller d _MS. That is, it is utilized that the signal magnetic field from the magnetic disk reaching the thin film magnetic head becomes stronger as _dMS is smaller. Therefore, nowadays with an increase in recording density, the value of d _MS is designed to be reduced to about 10 nm.

However, at the time of signal writing, Joule heat due to the signal current is generated from the coil layer in the dielectric electromagnetic transducer, and further, heat accompanying eddy current loss is generated in the upper and lower magnetic pole layers in the dielectric electromagnetic transducer. This heat generation is accumulated inside, and the overcoat layer, which is an insulating film, thermally expands, and a TPTP (Thermal Pole Tip Protrusion) phenomenon occurs in which the dielectric electromagnetic conversion element and the magnetoresistive effect element are pushed out toward the magnetic disk surface. Therefore, when the design value of d _MS is very small, the magnetoresistive element portion protruding contacts the magnetic disk surface, the electrical resistance of the magnetoresistive element is changed by the frictional heat of the abnormal signal (Thermal asperity) may occur.

To avoid this thermal asperity, a method for controlling the d _MS it has been proposed. For example, Patent Document 1 discloses a method of providing a heating element in a slider body including a transducer that is a magnetic head element or in the vicinity of a transducer in the slider body or between the slider body and the transducer. Yes. The heating element is heated by conduction, by utilizing the difference in thermal expansion coefficient between the transducer forming region and the slider body including a protective film, and controls the d _MS is protruded transducer.

  Patent Document 2 discloses a thin film magnetic head structure in which an element for writing and reading is brought close to a magnetic disk surface by energizing a thermal expansion body. In this structure, a heating element and a thermal expansion body are arranged in pairs, the thermal expansion body paired with the heating element is thermally expanded by the heat of the heating element, and the overcoat layer is distorted by the distortion force. Elements for writing and reading are brought close to the magnetic disk surface.

Further, Patent Document 3 discloses a thin film magnetic head provided with heat generating means provided at a position opposite to the air lubrication surface of the magnetic head element. By heating means it is brought into heat during operation of the magnetic head element, a magnetic head element to protrude air bearing surface direction to adjust the d _MS.

US Pat. No. 5,991,113 JP 2003-272335 A JP 2003-168274 A

  However, the thin film magnetic head provided with such a heating element and / or a thermal expansion body has a problem particularly in a magnetic head element for reading which is sensitive to heat.

  As described above, with the increase in capacity and recording density of magnetic disk devices, high performance and high reliability are required for each element constituting the device. In particular, in the magnetoresistive effect element for reading, the element size is reduced due to the narrowing of the track width and the request to detect the minute signal magnetic field with high resolution, while flowing to the element to ensure high output. The current density is very high. Therefore, the magnetoresistive effect element has a considerably high temperature even during normal operation. Further, as the magnetic field sensitivity of the magnetoresistive effect element is improved, the output of the element is strongly dependent on the temperature. Therefore, in order to stably secure the signal reading capability, temperature control, particularly suppression of further temperature rise, is an essential requirement.

  However, in the techniques described in Patent Documents 1 to 3 above, there is a problem in that heat from the heating element causes a further temperature increase in the magnetoresistive effect layer in the magnetoresistive effect element, thereby reducing the signal reading ability. It was happening.

  That is, in Patent Document 1, since the heating element is installed in the slider body or between the slider body and the transducer, the heat of the heating element is directed from the slider side toward the entire transducer formation region including the protective film. Propagate. At this time, the shield layer in the magnetoresistive effect element is generally a metal, and its thermal conductivity is generally higher than that of the overcoat layer which is an insulator. Therefore, the heat received on the shield layer surface easily reaches the magnetoresistive layer sandwiched between the shield layers. In Patent Documents 2 and 3, since the heating element is installed in the vicinity of the magnetoresistive effect element, the heat of the heating element or the heating means is easily propagated to the magnetoresistive effect layer through the shield layer.

  That is, in the techniques described in these documents, since a means for preventing the heat from the heating element or the heating means from reaching the magnetoresistive effect layer is not adopted, in addition to the amount of heat generated by the magnetoresistive effect element itself, The amount of heat as a disturbance is added, and the temperature of the magnetoresistive effect layer may rise above an allowable limit, causing a problem that a desired reading ability cannot be obtained.

  Furthermore, in the technique of Patent Document 1 or 3, the heating element is provided in the slider, or the heating element is in contact with the slider, or the distance between the heating means and the slider is reduced. Therefore, much of the heat from the heating element is absorbed by the slider having a relatively high thermal conductivity and released outside the thin film magnetic head. That is, the thermal efficiency for causing the TPTP phenomenon is low. If the amount of heat generation is increased to cope with this, the temperature of the magnetoresistive effect layer is increased through the shield layer, and as a result, the reading ability of the magnetoresistive effect element is lowered.

Accordingly, an object of the present invention, while avoiding the thermal asperity by adjusting sufficiently small predetermined value d _MS by utilizing positively the TPTP phenomenon, limiting the propagation of heat to the magneto-resistive layer for reading An object of the present invention is to provide a thin film magnetic head capable of maintaining a signal reading capability, an HGA including the thin film magnetic head, and a magnetic disk device including the HGA.

  According to the present invention, a slider having an air-lubricated surface, at least one read magnetic head element provided on the slider, and provided at a position opposite to the slider of the at least one read magnetic head element, At least one write magnetic head element having a magnetic pole portion, an overcoat layer formed on the slider so as to cover the at least one write magnetic head element and at least one read magnetic head element, and provided in the overcoat layer A thin film magnetic head comprising at least one read magnetic head element or at least one heat generating element that generates heat during at least operation of the at least one read magnetic head element, the at least one heat generating element comprising: Of at least one write magnetic head element The air-lubricated surface of the magnetic pole part is provided at a position opposite to the rider, and the end of the air-lubricated surface side of the at least one heating element is compared with the end of the magnetic pole part opposite to the air-lubricated surface. There is provided a thin film magnetic head provided at a position that is the same distance from a head end face (PTR (Pole Tip Recession) face) or a position that is further away from the head end face.

  Since the heating element is provided at a position opposite to the slider of the write magnetic head element, a predetermined distance is ensured with the slider. Therefore, the amount of heat from the heating element that is absorbed by the slider and released outside the thin film magnetic head is reduced. Therefore, the heat from the heating element can be used to cause the TPTP phenomenon more efficiently. As a result, the energization amount to the heating element required to obtain the predetermined protrusion amount of the magnetic head element can be smaller than that in the conventional technique. As a result, the amount of heat propagating to the magnetoresistive effect layer can also be reduced, and the temperature rise is prevented, so that the signal reading ability of the magnetoresistive effect element is maintained.

  Also, the end of the heating element on the air lubrication surface side is provided at the same distance from the PTR surface or at a position farther from the end opposite to the air lubrication surface of the magnetic pole part. The surface of the body facing the slider and the surface of the magnetic pole portion opposite to the slider do not have overlapping portions. Furthermore, the heating element is separated from the vicinity of the magnetoresistive effect layer facing the PTR surface and the magnetic pole portion having high thermal conductivity by a predetermined distance or more. As a result, the propagation of heat from the heating element to the magnetoresistive effect layer for reading is suppressed, and the signal read capability of the magnetoresistive effect element is maintained.

  In other words, by defining the position of the heating element as described above, while avoiding thermal asperity, the propagation of heat to the magnetoresistive effect layer for reading that could not be conventionally avoided or controlled is limited. The read capability of the thin film magnetic head can be maintained.

  Further, since the write magnetic head element is located between the read magnetic head element and the heating element, the heat from the heating element is read compared to the configuration in which the read magnetic head element is adjacent to the heating element. Hard to reach the magnetic head element. As a result, the temperature rise of the magnetoresistive effect layer is suppressed, and the signal reading ability is easily maintained.

  The magnetic pole portion includes a lower magnetic pole layer and an upper magnetic pole layer that is magnetically connected to the lower magnetic pole layer and is located on the opposite side of the slider of the lower magnetic pole layer. The opposite end is preferably the end opposite to the air lubrication surface of the bottom pole layer.

  The distance from the end of the air lubrication surface side of at least one heating element to the PTR surface is preferably in the range of 0.083 to 0.250 in terms of the height of the slider. When the heating element is within this range, the propagation of heat from the heating element to the magnetoresistive effect layer is suppressed, and the TPTP phenomenon having a sufficiently large size is achieved as compared with the case where the heating element is located outside the above range. Can cause. As a result, the bit error rate when a predetermined signal is written and read using a thin film magnetic head is reduced by about an order of magnitude or more compared to the case where the read signal is out of this range. The overall writing ability and reading ability of the head are further improved.

  The distance between the surface of the at least one heating element facing the slider and the surface of the pole layer opposite to the slider is within the range of 0.017 to 0.040 in terms of the slider height. Preferably there is. When the heating element is within this range, heat radiation to the outside of the thin film magnetic head can be suppressed, and the TPTP phenomenon can be caused with higher thermal efficiency. As a result, the bit error rate when a predetermined signal is written and read using a thin film magnetic head is reduced by about an order of magnitude or more compared to the case where the read signal is out of this range. The overall writing ability and reading ability of the head are further improved.

  The magnetic pole portion includes a lower magnetic pole film and an upper magnetic pole film that is magnetically connected to the lower magnetic pole film and is located on the opposite side of the slider of the lower magnetic pole film, and is opposite to the slider of the magnetic pole part. It is preferable that the surface on the side is the surface on the side opposite to the slider of the upper magnetic pole layer.

  At least one read magnetic head element includes an in-plane energization type (CIP (Current In Plain)) giant magnetoresistive effect (GMR (Giant Magneto Resistive)) element, a vertical energization type (CPP (Current Perpendicular to Plain)) GMR element, or A tunnel magnetoresistive (TMR (Tunnel Magneto Resistive)) element is preferable. All of the CIP-GMR element, CPP-GMR element, and TMR element have very high magnetic field sensitivity, but their output strongly depends on temperature. By using these elements as the read magnetic head elements of the thin film magnetic head according to the present invention, it is possible to effectively use the high magnetic field sensitivity of these elements while avoiding a decrease in read ability due to a temperature rise.

  According to the present invention, the thin film magnetic head described above, at least one read magnetic head element of the thin film magnetic head, a signal line to the at least one write magnetic head element, and at least one heat generation of the thin film magnetic head are further provided. An HGA including a lead wire for supplying a current to the body and a support mechanism for supporting the thin film magnetic head is provided.

  According to the present invention, there is further provided a magnetic disk device that includes at least one HGA as described above and further includes current control means for controlling a current supplied to at least one heating element.

  The current control means is preferably control means for supplying a current to the at least one heating element during at least operation of at least one read magnetic head element and / or at least one write magnetic head element.

  This current control means has a heating element control signal system, and this heating element control signal system is independent of the operation control signal system of at least one read magnetic head element and / or at least one write magnetic head element. Thus, it is preferable to control the current supplied to the heating element. In this way, by providing a heating element control signal system independent of the recording / reproducing operation control signal system, not only energization to the heating element linked to the recording / reproducing operation but also various energization modes are realized. can do.

A thin film magnetic head of the present invention, according to the magnetic disk device equipped with HGA and the HGA with the thin-film magnetic head, a thermal by adjusting sufficiently small predetermined value d _MS by utilizing positively the TPTP phenomenon While avoiding asperity, the propagation of heat to the magnetoresistive layer for reading can be restricted to maintain the signal reading capability.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated in detail, referring an accompanying drawing.

  FIG. 1 is a perspective view schematically showing a configuration of a main part in an embodiment of a magnetic disk apparatus according to the present invention, FIG. 2 is a perspective view showing an entire HGA, and FIG. 3 is attached to a front end portion of the HGA. 2 is a perspective view of a thin film magnetic head (slider) that is used. FIG.

  In FIG. 1, reference numeral 10 denotes a plurality of magnetic disks that rotate around a rotation axis 11 of a spindle motor, 12 denotes an assembly carriage device for positioning a thin film magnetic head (slider) on a track, and 13 denotes a read / write operation of the thin film magnetic head. And a recording / reproducing circuit for controlling the heating operation.

  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 slider so as to face the surface of each magnetic disk 10. The magnetic disk 10, the drive arm 14, the HGA 17, and the thin film magnetic head (slider) may be singular.

  As shown in FIG. 2, the HGA 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.

  It is obvious that the suspension structure in the HGA of the present invention is not limited to the structure described above. Although not shown, a head driving IC chip may be mounted in the middle of the suspension 20.

  As shown in FIG. 3, the slider in this embodiment includes a write magnetic head element and a read magnetic head element 30 stacked on each other, four signal terminal electrodes 31 connected to these elements, and FIG. Two drive terminal electrodes 32 for current flowing through a heater that is not provided are provided on the element forming surface 33. In FIG. 3, reference numeral 34 denotes an air lubrication surface of the slider.

  FIG. 4 is a diagram showing a schematic configuration in an embodiment of a thin film magnetic head according to the present invention.

  In the figure, a slider 40 has an air lubrication surface 50, and floats with a predetermined gap hydrodynamically on a rotating magnetic disk surface 52 during a writing or reading operation. On one side surface (element formation surface) when the air lubrication surface of the slider 40 is the bottom surface, a magnetoresistive effect element 42 for reading, a dielectric electromagnetic transducer element 44 for writing, and an overcoat covering these elements are provided. A coat layer 47 is formed.

  The magnetoresistive effect element 42 includes a magnetoresistive effect layer 42c, and a lower shield layer 42a and an upper shield layer 42f arranged at positions sandwiching this layer. The magnetoresistive effect layer 42c is made of a CIP-GMR multilayer film, a CPP-GMR multilayer film, or a TMR multilayer film, and senses a signal magnetic field with very high sensitivity. The lower shield layer 42a and the upper shield layer 42f are magnetic layers and have a role of blocking an external magnetic field that becomes noise with respect to the magnetoresistive effect layer 42c. The dielectric electromagnetic transducer 44 includes a lower magnetic pole layer 44a, an upper magnetic pole layer 44f, and a coil layer 44c. The lower magnetic pole layer 44a and the upper magnetic pole layer 44f are magnetic paths for guiding the magnetic flux generated from the coil 44 layer c while converging it to the magnetic disk surface 52 on which writing is performed.

The ends of the magnetoresistive effect element 42 and the dielectric electromagnetic conversion element 44 on the magnetic disk surface 52 side reach the PTR surface 51. Here, the PTR surface 51 is coated with DLC (Diamond Like Carbon) or the like as a protective film. The distance of the magnetic head element during the operation of the PTR surface and the magnetic disk surface of the magnetic head element portion is d _MS.

  The heating element 46 is formed on the overcoat layer 47. As a result, the heating element 46 is provided at a position opposite to the slider 40 of the magnetoresistive effect element 42 and the dielectric electromagnetic conversion element 44. Further, an overcoat layer 48 is formed on the overcoat layer 47 so as to cover the heating element 46.

  Next, the configuration of the thin film magnetic head in the embodiment of FIG. 4 will be described in more detail. 5 is a plan view of the thin film magnetic head in the embodiment of FIG. 4 as seen through from the element forming surface side of the slider, FIG. 6 is a sectional view taken along line AA, and FIG. 7 is a line taken along line BB. It is sectional drawing. Note that the number of turns of the coil in FIG. 6 is shown to be smaller than the number of turns in FIG. 5 in order to simplify the drawing. The coil may be a two-layer or helical coil. 5 and 6, the configuration of the heating element 46 is also shown in a simplified manner for the purpose of detailed description later.

In these drawings, reference numeral 40 denotes a slider made of, for example, AlTiC (Al ₂ O ₃ —TiC), and 41 denotes an insulating film having a thickness of about 0.05 μm to about 10 μm made of, for example, Al ₂ O ₃ laminated on the slider 40. The layer 42a is laminated on the insulating layer 41, for example, a lower shield layer made of, for example, NiFe, NiFeCo, CoFe, FeN, FeZrN or the like with a thickness of about 0.3 μm to about 3 μm, and 42b is laminated on the lower shield layer 42a. For example, a lower shield gap layer made of Al ₂ O ₃ or DLC having a thickness of about 0.005 μm to about 0.5 μm, 42c is laminated on the lower shield gap layer 42b, for example, CIP-GMR multilayer film, CPP-GMR multilayer The magnetoresistive effect layer 42d comprising a film or a TMR multilayer film has a magnetic bias layer and is connected to both ends of the magnetoresistive effect layer 42c. The element lead conductor layer 42e made of Cu or the like, for example, has a thickness of about 0.005 μm to about 0.005 m made of, for example, Al ₂ O ₃ or DLC laminated on the magnetoresistive effect layer 42c and the element lead conductor layer 42d. An upper shield gap layer having a thickness of about 5 μm and 42 f are upper shield layers having a thickness of about 0.3 μm to about 4 μm made of, for example, NiFe, NiFeCo, CoFe, FeN, or FeZrN, which are stacked on the upper shield gap layer 42 e. . The reproduction gap length, which is the distance between the upper and lower shield layers 42f and 42a, is about 0.03 μm to about 1 μm.

43 is an insulating layer made of, for example, Al ₂ O ₃ or the like, which is laminated on the upper shield layer 42f, and has a thickness of about 0.1 μm to about 2.0 μm, and 44a is, for example, NiFe, NiFeCo, CoFe laminated on the insulating layer 43. , FeN or FeZrN or the like, and a lower magnetic pole layer having a thickness of about 0.3 μm to about 3 μm, and 44b having a thickness of about 0.03 μm to about 3 μm made of Al ₂ O ₃ or DLC, etc. A magnetic gap layer having a thickness of 0.5 μm (corresponding to a recording gap length), 44c is a coil layer having a thickness of about 0.5 μm to about 3 μm made of, for example, Cu laminated on the magnetic gap layer 44b, and 44d is a coil layer 44c. A coil insulating layer having a thickness of about 0.1 μm to about 5 μm, for example, a covering layer such as a heat-cured resist layer, and 44e is, for example, Cu or NiFe electrically connected to one end of the coil layer 44c. A coil lead conductor layer 44f, which forms a magnetic pole and a magnetic yoke together with the lower magnetic pole layer 44a, for example, an upper magnetic pole layer made of NiFe, NiFeCo, CoFe, FeN, FeZrN or the like having a thickness of about 0.5 μm to about 5 μm; An overcoat layer made of Al ₂ O ₃ or the like is shown. Note that the insulating layer 43 is not necessarily provided.

Reference numeral 46 denotes a heating element formed on the overcoat layer 47 that covers the upper magnetic pole layer 44f. Since the heating element 46 is formed on the overcoat layer 47, the heating element 46 is always provided at a position opposite to the slider of the magnetoresistive effect element 42 and the dielectric electromagnetic conversion element 44. Reference numeral 48 denotes an overcoat layer made of, for example, Al ₂ O ₃ that covers the entire heating element 46. The position of the heating element 46 is the thickness D _YORK of the overcoat layer 47 from the surface of the upper magnetic pole layer 44f opposite to the slider, and the end of the heating element 46 on the PTR surface 51 side to the PTR surface 51. Defined by the distance _DPTR .

  FIG. 8 is a diagram showing the configuration of the heating element 46 of the thin film magnetic head in the embodiment of FIG. FIG. 9 is a cross-sectional view taken along line CC in FIG. 5 for illustrating the configuration of the electrode pad portion of the heating element 46.

  According to FIG. 8, the heating element 46 has a heating part 46a in which one line meanders in the layer, and lead electrodes 46b and 46c connected to both ends of the heating part 46a, respectively. It is a long current path.

  More specifically, the heat generating portion 46 a includes an ascending portion 66 formed so as to meander in a rectangular wave shape from a predetermined starting point 60 to a turning point 61, and an ascending portion 66 from the turning point 61 to an end point 62 in the vicinity of the starting point 60. , And a connecting portion 74 that connects the start point 60 and the extraction electrode 46c, and a connection portion 74 that connects the end point 62 and the extraction electrode 46b. Further, the interval 70 between the ascending portion 66 and the descending portion 67 formed along each other is narrower than the interval 72 between the ascending portions 66 facing each other and the interval 73 between the descending portions 87 facing each other. Is set to

  The heat generating portion 46a has a thickness of about 100 nm to about 5000 nm, for example, and is made of a material containing NiCu, for example. Here, the content ratio of Ni in NiCu is, for example, about 15 to about 60 atomic%, and preferably 25 to 45 atomic%. Further, the additive for NiCu contains at least one element of Ta, Al, Mn, Cr, Fe, Mo, Co, Rh, Si, Ir, Pt, Ti, Nb, Zr and Hf. Also good. The content of these additives is preferably 5 atomic% or less.

  Moreover, the heat generating part 46a may be made of a material containing NiCr, for example. In this case, the content ratio of Ni in NiCr is, for example, about 55 to about 90 atomic%, and preferably 70 to 85 atomic%. Further, the additive for NiCr contains at least one element of Ta, Al, Mn, Cu, Fe, Mo, Co, Rh, Si, Ir, Pt, Ti, Nb, Zr and Hf. Also good. The content of these additives is preferably 5 atomic% or less. The lead electrodes 46b and 46c are made of the same material as the heat generating portion 46a.

  According to FIG. 9, conductive electrode film members 80b and 80c are formed on the extraction electrodes 46b and 46c, respectively. On the electrode film members 80b and 80c, bumps 81b and 81c extending upward are formed by electroplating using the electrode film members 80b and 80c as electrodes. The electrode film members 80b and 80c and the bumps 81b and 81c are made of a conductive material such as Cu. The electrode film members 80b and 80c have a thickness of about 10 nm to about 200 nm, and the bumps 81b and 81c have a thickness of about 5 μm to about 30 μm.

  The upper ends of the bumps 81b and 81c are exposed from the overcoat layer 48, and pads 82b and 82c for the heating element 46 are provided on these upper ends, respectively. A current is supplied to the heating element 46 through the pads 82b and 82c. Similarly, the magnetoresistive effect element 42 and the inductive electromagnetic transducer 44 are connected to the signal terminal electrode 31 (FIG. 3), but these connection structures are not shown for the sake of simplification of the drawing. .

  FIG. 10 is a process diagram for explaining a manufacturing process of the thin film magnetic head in the embodiment of FIG. 4, and shows a cross section taken along line AA of FIG.

  The manufacturing process of the thin film magnetic head in this embodiment will be briefly described below with reference to FIG. First, as shown in FIG. 10A, an insulating layer 41 is stacked on the substrate 40 by, eg, sputtering. Next, the lower shield layer 42a is formed on the insulating layer 41 by plating, for example. Next, the lower shield gap layer 42b, the magnetoresistive effect layer 42c, the element lead conductor layer 42d including the magnetic bias layer, and the upper shield gap layer 42e are formed by, for example, sputtering. Next, the upper shield layer 42f is formed by, for example, a plating method. Thereafter, a planarization layer 47a is formed on the rear side as viewed from the PTR surface. The formation of the magnetoresistive element 42 is completed through the above steps.

Next, as shown in FIG. 10B, the insulating layer 43, the lower magnetic pole layer 44a, and the magnetic gap layer 44b are formed on the upper shield layer 42f by, for example, sputtering, and the rear side as viewed from the PTR surface. Then, a planarizing layer 47b is formed. Next, the coil insulating layer 44d and the upper magnetic pole layer 44f are formed on the magnetic gap layer 44b so as to cover the coil layer 44c by a known method such as photolithography and dry etching. The formation of the inductive electromagnetic transducer 44 is completed through the above steps. Furthermore, a flattened overcoat layer 47c is formed in preparation for the formation of the heating element 46 as the next step (FIG. 10C). At this time, the thickness D _YORK of the overcoat layer 47c from the upper magnetic pole layer 44f is formed to be a value within a predetermined range.

Next, as shown in FIG. 10D, the heat generating portion 46a and the extraction electrodes 46b and 46c are formed at predetermined positions on the overcoat layer 47c by, for example, sputtering. This position is determined so that the distance D _PTR from the end of the heat generating portion 46a on the PTR surface 51 side to the PTR surface 51 becomes a value within a predetermined range. Finally, an overcoat layer 48 that covers the heating element 46 is formed (FIG. 10E).

  FIG. 11 is a block diagram showing a circuit configuration of the recording / reproducing circuit 13 of the magnetic disk apparatus in the embodiment of FIG. FIG. 12 is a block diagram showing the configuration of the heating element control circuit of the magnetic disk device in the embodiment of FIG.

  In FIG. 11, reference numeral 90 denotes a recording / reproduction control LSI, which includes a thermal asperity (TA) detection circuit 90a. 91 is a write gate that receives recording data from the recording / reproduction control LSI 90, 92 is a write circuit, 93 is a ROM that stores a control table for the current value to the heating element, etc. 95 is a sense current supplied to the magnetoresistive effect element 42 , A constant current circuit 96, an amplifier that amplifies the output voltage of the magnetoresistive effect element 42, 97 a demodulation circuit that outputs reproduction data to the recording / reproduction control LSI 90, 98 a temperature detector, and 99 a heating element 46. Each control circuit is shown.

  The recording data output from the recording / reproducing control LSI 90 is supplied to the write gate 90. The write gate 90 supplies recording data to the write circuit 92 only when a recording control signal output from the recording / reproducing control LSI 90 instructs a writing operation. The write circuit 92 applies a write current to the coil layer 44c in accordance with the recording data, and performs recording on the magnetic disk 10 (FIG. 1) by the dielectric electromagnetic conversion element 44.

  A constant current flows from the constant current circuit 95 to the magnetoresistive effect layer 42c only when the reproduction control signal output from the recording / reproduction control LSI 90 instructs a read operation. The signal reproduced by the magnetoresistive effect element 42 is amplified by the amplifier 96 and then demodulated by the demodulation circuit 97, and the obtained reproduction data is output to the recording / reproduction control LSI 90.

  The heating element control circuit 99 in the present embodiment is configured as shown in FIG. That is, a series circuit including a DC constant voltage circuit 99a, a switching transistor 99b, and a variable resistor 99c is connected to the heat generating portion 46a of the heat generating body 46. The heating element ON / OFF signal output from the recording / reproducing control LSI 90 is supplied to the switching transistor 99b. The heating element current value control signal output from the recording / reproducing control LSI 90 is converted into an analog signal by the D / A converter 99d and then supplied to the variable resistor 99c.

  When the heating element ON / OFF signal is an ON operation instruction, the switching transistor 99b is turned on and a current flows to the heating part 46a of the heating element 46. The current value at this time is controlled to a value corresponding to the heating element current value control signal converted into analog in the variable resistor 99c.

  Thus, by providing the heating element ON / OFF signal and the heating element current value control signal system independently of the recording / reproducing operation control signal system, not only the energization of the heating element in conjunction with the recording / reproducing operation is performed. More various energization modes can be realized.

In actual operation, a current corresponding to a predetermined energization mode flows through the heat generating portion 46a of the heat generating element 46. Due to this current, the portion of the heating element 46 and its surroundings are heated and thermally expanded, and the dielectric electromagnetic conversion element 44 and the magnetoresistive effect element 42 slightly project in the direction of the PTR surface 51. Thus, it is possible to reduce only the d _MS during a write operation and a read operation. Thus, by reducing the _dMS only during the operation of the magnetic head element, the signal writing capability and / or the signal accompanying the narrowing of the track width can be achieved without increasing the probability of a crash of the slider colliding with the magnetic disk surface. It is possible to compensate for the weakening of the reading magnetic field and the weakening of the signal magnetic field accompanying the miniaturization of the recording bit. This d _MS value can be adjusted with high accuracy by a heating element current value control signal for controlling the current flowing through the heating portion 46a.

  Obviously, the circuit configuration of the recording / reproducing circuit 13 is not limited to that shown in FIGS. The write operation and the read operation may be specified by a signal other than the recording control signal and the reproduction control signal. In addition, it is desirable to generate heat in the heating element 46 at least during both the write operation and the read operation. However, only one of the write operation and the read operation, or the write operation and the read operation are continued within a certain period. Thus, the heating element 46 can also generate heat. Furthermore, it is possible to use not only a direct current but also an alternating current or a pulse current as a current to be supplied to the heating element 46.

  Hereinafter, an embodiment of the energization mode for the heating element 46 will be described.

First, a description will be given of the initial setting of the power supplied to the heating element for controlling the d _MS. In general, the d _MS value of each thin film magnetic head varies. Therefore, first, an AE (Acoustic emission) component in the reproduction data is detected by the TA detection circuit 90a in the innermost track of the magnetic disk, and the heating element 46 is energized to a current amount that generates AE (Acoustic emission) exceeding the reference range. Then, the limit current amount is determined. This amount of current is recorded in the ROM 93. Why Use innermost track, since d _MS in a seek operation is smallest at the innermost, because a reference of the upper limit of the current amount. Then, using a table of general recorded in ROM93 "current vsTPTP protrusion amount", it sets the amount of current becomes a desired _{d MS.}

  Next, power supply during normal operation of the magnetic disk device will be described. First, writing and reading are performed while the heating element 46 is energized with the set current amount. If the AE generation amount is within the reference range, the operation is performed as it is. When exceeding the reference range, the current amount is decreased by a predetermined unit, and the AE generation amount is continuously monitored. Thereafter, this cycle is repeated. At this time, if the amount of AE generated exceeds the reference range even after a predetermined number of repetitions, the flag indicating that the head is suspended is assumed to be unstable or a sign of a crash. Notify the CPU.

_Next, a description will be given of a temperature compensation of the _{d MS.} Slider for floating hydrodynamically, d _MS is influenced by the temperature of the apparatus. Further, the protrusion amount of the magnetic head element due to the TPTP phenomenon is also affected by the temperature inside the apparatus as a background. Therefore, a table of “temperature vs. _MS change inside device” based on the characteristics of the temperature detector 98 (for example, resistance type sensor) and the TPTP protrusion amount is stored in the ROM 93, and the temperature is monitored by the temperature detector 98. . Corresponding to the apparatus internal temperature to adjust the amount of current by referring to this table, to ensure a constant d _MS.

Next, a description will be given compensation by other factors d _MS. d _MS also fluctuates due to atmospheric pressure changes or external vibrations in the device. However, normally, no atmospheric pressure sensor or vibration sensor is installed in the magnetic disk device. Therefore, first, _dMS is adjusted based on the temperature inside the apparatus. After this adjustment, if the amount of generated AE is still a reference range, it is regarded as a variation of the d _MS by pressure changes, or vibration, etc., to reduce the current supplied to the first predetermined amount heating element. If the AE generation amount is still outside the reference range, the current is decreased by a second predetermined amount. Thereafter, this cycle is repeated. At this time, if the amount of AE generated exceeds the reference range even after a predetermined number of repetitions, the flag indicating that the head has been suspended is used as an indication that the head is in an unstable state or is a precursor to a crash. Notice.

Furthermore d _MS also varies depending on the position in the magnetic disk. This is because the medium moving speed is different between the inner peripheral side and the outer peripheral side even at the same rotational speed. Therefore, it is possible in accordance with the radius of the recording and reproducing position in the magnetic disk, achieving a constant of d _MS the current supplied to the heating element is finely adjusted.

Further, when used in an in-vehicle device such as a car navigation system, a strong vibration mode (AE frequency mode) can be set such that energization is set to the evacuation mode and _dMS is sufficiently increased.

  Hereinafter, the influence of the position of the heating element 46 on the TPTP phenomenon caused by the heating element 46 will be described.

In FIG. 4, the heating element 46 generates heat by energization and supplies heat to the vicinity of the overcoat layers 47 and 48. As a result, the overcoat layers 47 and 48 accumulate heat and thermally expand in accordance with the temperature distribution. This thermal expansion, the magnetoresistive element 42 and the inductive element 44 is pushed to the magnetic disk surface 52 direction, d _MS is smaller PTR surface 51 protrudes. At this time, the amount of decrease in d _MS becomes controllable by the amount of current supplied to the heater 46.

  Here, the heat generated from the heating element 46 propagates to the upper and lower magnetic pole layers 44a and 44f and the upper and lower shield layers 42f and 42a by an amount corresponding to the positional relationship with the heating element 46. As described above, these pole layers and shield layers are generally metals such as NiFe, and their thermal conductivity is higher than that of an overcoat layer that is an insulator. Therefore, for example, heat propagated from the heating element 46 and received by the upper shield layer 42f is positively transmitted to the magnetoresistive effect layer 42c sandwiched between the shield layers. As a result, when the amount of heat increases, the temperature of the magnetoresistive effect layer 42c is increased to an allowable limit or more, and the reading ability of the magnetoresistive effect element 42 is lowered.

As a means for preventing this decrease, the position of the heating element 46 in the overcoat layers 47 and 48 is adjusted. That is, by adjusting the position, the amount of heat that propagates to the pole layer and the shield layer is limited. At this time, as described above, the position parameter of the heating element 46 faces the distance D _PTR from the end of the heating unit 46a of the heating element 46 on the PTR surface 51 side to the PTR surface 51 and the slider 40 of the heating element 46. A distance D _YORK between the surface and the surface of the upper magnetic pole layer 44f opposite to the slider 40 is used.

FIG. 13 is a diagram showing the relationship between _DPTR or its standard value and the bit error rate in the thin film magnetic head in the embodiment of FIG. FIG. 14 is a diagram showing the positions of typical heating elements 46 having different _DPTR values.

In FIG. 13, the horizontal axis indicates D _PTR or its standard value ND _PTR . ND _PTR is the value of D _PTR when the slider height H _S is 1, and in this embodiment, H _S = 300 μm, so ND _PTR = D _PTR (μm) / 300 (μm) Become. The vertical axis, the temperature rise of the magnetoresistive layer 42c, and the simulation value of the amount of change d _MS, and shows the measured values of the bit error rate. The bit error rate is a ratio of bits in which an error occurs in the reproduction data when data is written and read by the thin film magnetic head to be measured in a state where the heating element 46 is heated by energization, This is the value when no digital signal processing is performed. A spin stand was used in the measurement of the bit error rate. As the channel IC, Diamondback manufactured by Agere was used, the data rate was 650 Mbps, and the recording density of the signal recorded on the magnetic disk was 700 kFCI. The sample size was 1 × 10 ⁹ bits. The size of the heating part 46a of the heating element 46 is 100 μm (height) × 100 μm (width), and the power supplied to the heating element is 100 mW. Furthermore, D _YORK was 7 μm, and the length of the lower magnetic pole layer was 25 μm.

According to FIG. 13, the bit error rate shows a good value of 1 × 10 ⁻⁶ or less when D _PTR (ND _PTR ) is in the range of 25 to 75 μm (0.083 to 0.250). However, when D _PTR is smaller than 25 μm, the bit error rate increases rapidly and exceeds the value of the lower half of the 10 ⁻⁵ range that is allowed as a magnetic disk device. On the other hand, when the D _PTR is greater than 75 [mu] m, was similarly increased bit error rate, albeit within acceptable magnetic disk device becomes an order of magnitude or more higher values. Thus, the bit error rate, D _PTR becomes smaller cut 25 [mu] m, or an critical change becomes greater beyond 75 [mu] m. Therefore, D _PTR is 25~75μm range, compared with other regions, it is clear that a range of a very remarkable effect that about one order of magnitude or more low bit error rate.

Here, the factors that change the bit error rate will be described. When _DPTR is less than 25 μm (near position a in FIG. 14), the length of the lower magnetic pole layer is 25 μm. Therefore, the surface of the heating element 46 and the surface of the lower magnetic pole layer 44a always have portions that overlap each other and face each other. Become. Further, the heating element 46 is positioned in the vicinity of the magnetoresistive effect layer 42c facing the PTR surface and the upper and lower shield layers and the upper and lower pole layers having high thermal conductivity. As a result, the magnetoresistive layer 42c receives a considerable amount of heat from the heating element 46, so that the temperature becomes very high. Therefore, the signal reading ability of the magnetoresistive effect element 42 is reduced. At this time, the TPTP phenomenon also becomes prominent and the PTR surface protrudes up to 51a (FIG. 14), and _dMS is reduced. However, the above-described decrease in the reading capability is exceeded, and the bit error rate is eventually increased.

On the other hand, the distance D when the _PTR exceeds 75 [mu] m (near the position c in FIG. 14), the temperature rise of the magnetoresistive layer 42c but is considerably suppressed, sufficient heat of the heating element 46 is in the overcoat layer in the vicinity of both elements Since it is not propagated, the protrusion amount 51c (FIG. 14) of the magnetoresistive effect element 42 and the dielectric electromagnetic transducer 44 becomes very small. Therefore, since sufficiently small d _MS in a predetermined range can not be secured, the signal magnetic field in the magnetoresistive layer 42c position become weak, the bit error rate is increased.

Unlike ranges stated _above, in the _{D PTR} is 25~75μm range (near position b in FIG. 14), side heating elements 46 and the lower magnetic pole layer 44a faces have no portion facing overlap each other. Further, the heating element 46 is separated from the magnetoresistive effect layer 42c facing the PTR surface by a predetermined distance from the upper and lower shield layers and the upper and lower pole layers having high thermal conductivity. As a result, the magnetoresistive effect layer 42c does not receive much heat from the heating element 46, and its temperature rise falls within an allowable range. Therefore, the signal reading capability of the magnetoresistive effect element 42 is maintained within the necessary range. On the other hand, the heating element 46 within this position range can supply a sufficient amount of heat to the overcoat layer in the vicinity of the magnetic head element to cause the protrusion 51b (FIG. 14) due to a predetermined TPTP phenomenon. As a result, a sufficiently small d _MS predetermined range because it is ensured, a sufficiently low bit error rate signal magnetic field is reliably perceived is realized.

FIG. 15 is a diagram showing the relationship between D _YORK or its standard value and the bit error rate in the thin film magnetic head in the embodiment of FIG. FIG. 16 is a diagram showing the positions of typical heating elements 46 having different D _YORK values.

In FIG. 15, the horizontal axis indicates D _YORK or its standard value ND _YORK . The normalization is the same as in FIG. 13, and ND _YORK = D _YORK (μm) / 300 (μm). The vertical axis is also the same as in FIG. The measurement conditions of the bit error rate are the same as the measurement in FIG. The size of the heating part 46a of the heating element 46 is 100 μm (height) × 100 μm (width), and the power supplied to the heating element is 100 mW. Further, _DPTR was 50 μm, and the length of the bottom pole layer was 25 μm.

According to FIG. 15, the bit error rate shows a good value of 1 × 10 ⁻⁶ or less when D _YORK (ND _YORK ) is in the range of 5 to 12 μm (0.017 to 0.040). However, when D _YORK becomes smaller than 5 μm or becomes larger than 12 μm, the bit error rate shows a critical change, which is about an order of magnitude or more within the allowable range of the magnetic disk device. Large value. Therefore, the range of D _{YORK of 2} to 12 μm is a range showing a very remarkable effect of a low bit error rate of about one digit or more as compared with other regions.

Here, the factors that change the bit error rate will be described. The position where D _YORK is less than 5 μm is the position where the heating element 46 is closer to the slider 40 (near position d in FIG. 16). Here, the slider 40 is a material having a relatively high thermal conductivity such as an AlTiC substrate as described above. As a result, most of the heat from the heating element 46 is finally absorbed by the slider 40 via the overcoat layer 47 and released outside the thin film magnetic head. Accordingly, since the amount of heat for causing the TPTP phenomenon is reduced by that amount, the protrusion 51d (FIG. 16) of the magnetoresistive element 42 and the dielectric electromagnetic transducer 44 in the direction of the magnetic disk surface 52 becomes small. As a result, the bit error rate is increased since a sufficiently small d _MS in a predetermined range can not be secured. Since the amount of heat radiated by the slider is large and the amount of heat transmitted to the upper and lower shield layers 42f and 42a is not so large, the temperature rise of the magnetoresistive layer 42c can be kept small. Therefore, the signal reading ability of the magnetoresistive effect element 42 is not significantly affected by the temperature rise.

On the other hand, when D _YORK exceeds 12 μm, the heating element 46 is far away from the slider 40 and the upper magnetic pole layer 44f (near position f in FIG. 16). Therefore, the heat from the heating element 46 is not transmitted to the overcoat layer in the vicinity of the magnetoresistive effect element 42 and the dielectric electromagnetic conversion element 44, but increases the amount of heat radiated to the outside of the thin film magnetic head. The protrusion 51f due to (FIG. 16) becomes smaller. As a result, the bit error rate is increased since small enough d _MS in a predetermined range can not be secured. Even in this range, the amount of heat transmitted to the upper and lower shield layers 42f and 42a is not so large, so that the temperature rise of the magnetoresistive layer 42c can be kept small. Therefore, the signal reading ability of the magnetoresistive effect element 42 is not significantly affected by the temperature rise.

Unlike the range described above, the distance D _YORK in the range of 5 to 12 μm (near the position e in FIG. 16) efficiently propagates the heat from the heating element 46 to the overcoat layer near the magnetic head element. TPTP phenomenon causing the protrusion 51e (FIG. 16) by which to secure a sufficiently small _{d MS} in a predetermined range. As a result, the signal magnetic field is reliably sensed and a sufficiently low bit error rate is realized.

  The position range of the heating element 46 that realizes the low bit error rate described above is a condition that exhibits a particularly remarkable effect of efficiently causing the TPTP phenomenon without adversely affecting the magnetoresistive effect element. Here, the protrusion amount itself in the TPTP phenomenon caused is not related to the signal recording density. Therefore, it is clear that this position range does not depend on the signal recording density on the magnetic disk in the above-described embodiment.

  On the other hand, the absolute value of the bit error rate depends on the signal recording density. Accordingly, in order to obtain a predetermined low bit error rate value at a higher signal recording density, the gap length of the dielectric electromagnetic transducer is narrowed, the recording magnetic field strength and gradient of the element are improved, and the magnetoresistive element It is necessary to narrow the reproduction gap length and improve the magnetoresistive effect change rate of the element. On the other hand, the limitation of the position range of the heating element in the present embodiment is a condition that exhibits a very remarkable effect of a low bit error rate of about one digit or more in the recording / reproducing environment defined by these measures. It has become.

  Furthermore, it is clear that the position range of the heating element in the present embodiment hardly depends on the power supplied to the heating element. That is, the absolute value of the calorific value has an approximately linear effect on the temperature at each point in the heat distribution by the heating element. On the other hand, the shape of the isotherm of the heat distribution, when the thermal equilibrium state is reached, depends on the relative positional relationship between the magnetoresistive layer and the magnetic head element adjacent to the heating element and the heating element. Mostly determined. Therefore, the limitation of the position range of the heating element in the present embodiment provides a condition showing a very remarkable effect of a low bit error rate of about one digit or more in a given power supply situation. .

  Further, all of the embodiments described above are merely illustrative of the present invention and are not intended to be limiting, and the present invention can be implemented in various other variations and modifications. 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 disk device according to the present invention. FIG. It is a perspective view showing the whole HGA in embodiment of FIG. 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. 1 is mounted | worn. 1 is a diagram showing a schematic configuration in an embodiment of a thin film magnetic head according to the present invention. FIG. 5 is a plan view of the thin film magnetic head in the embodiment of FIG. 4 as seen through from the element forming surface side of the slider. FIG. 6 is a cross-sectional view taken along line AA of FIG. 5, showing the configuration of the thin film magnetic head in the embodiment of FIG. 4. FIG. 6 is a cross-sectional view taken along line B-B in FIG. 5, showing the configuration of the thin film magnetic head in the embodiment of FIG. 4. It is a figure which shows the structure of the heat generating body of the thin film magnetic head in embodiment of FIG. It is sectional drawing in the CC line of FIG. 5 which shows the structure of the electrode pad part of a heat generating body. It is process drawing explaining the manufacturing process of the thin film magnetic head in embodiment of FIG. FIG. 2 is a block diagram showing a circuit configuration of a recording / reproducing circuit of the magnetic disk device in the embodiment of FIG. 1. FIG. 2 is a block diagram showing a configuration of a heater control circuit of the magnetic disk device in the embodiment of FIG. 1. FIG. 5 is a diagram showing the relationship between _DPTR or its standard value and the bit error rate in the thin film magnetic head in the embodiment of FIG. 4. It is the figure which showed the position of the typical heat generating body which has a different _DPTR value. FIG. 5 is a diagram showing a relationship between D _YORK or its standard value and a bit error rate in the thin film magnetic head in the embodiment of FIG. 4. It is the figure which showed the position of the typical heat generating body which has a different _DYORK value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic disk 11 Spindle motor rotating shaft 12 Assembly carriage apparatus 13 Recording / reproducing circuit 14 Drive arm 15 Voice coil motor 16 Pivot bearing shaft 17 HGA
20 Suspension 21, 40 Slider 22 Load beam 23 Flexure 24 Base plate 25 Wiring member 30 Write and read magnetic head element 31 Signal terminal electrode 32 Drive terminal electrode 33 Element formation surface 34, 50 Air lubrication surface 41, 43, 46b Insulating layer 42a Lower part Shield layer 42b Lower shield gap layer 42c Magnetoresistive effect layer 42d Element lead conductor layer 42e Upper shield gap layer 42f Upper shield layer 44a Lower pole layer 44b Magnetic gap layer 44c Coil layer 44d Coil insulation layer 44e Coil lead conductor layer 44f Upper pole layer 46 Heating element 46a Heating part 46b, 46c Lead electrode 47, 47c, 48 Overcoat layer 47a, 47b Planarization layer 51 PTR surface 51a, 51b, 51c, 51d, 51e, 1f Protruding PTR surface 52 Magnetic disk surface 60 Start point 61 Folding point 62 End point 66 Up part 67 Down part 70, 72, 73 Spacing 74, 75 Connection part 80b, 80c Electrode film member 81b, 81c Bump 82b, 82c Pad 90 Recording / reproduction Control LSI
90a TA detection circuit 91 Write gate 92 Write circuit 93 ROM
95 constant current circuit 96 amplifier 97 demodulation circuit 98 temperature detector 99 heater control circuit 99a DC constant voltage circuit 99b switching transistor 99c variable resistor 99d D / A converter

Claims (10)

  A slider having an air-lubricating surface; at least one read magnetic head element provided on the slider; and at least one read magnetic head element at a position opposite to the slider and having a magnetic pole portion One write magnetic head element, an overcoat layer formed on the slider so as to cover the at least one write magnetic head element and the at least one read magnetic head element, and provided in the overcoat layer A thin film magnetic head comprising at least one heating element that generates heat during at least operation of the at least one reading magnetic head element or the at least one writing magnetic head element, wherein the at least one heating element is Of at least one write magnetic head element The end of the at least one heating element on the side of the air lubrication surface is compared with the end of the magnetic pole portion on the side opposite to the air lubrication surface, A thin-film magnetic head, characterized in that it is provided at a position that is the same distance or farther from a head end surface that the end of the magnetic pole portion on the side of the air lubrication surface faces.   The magnetic pole portion includes a lower magnetic pole layer, and an upper magnetic pole layer that is magnetically connected to the lower magnetic pole layer and is located on a side opposite to the slider of the lower magnetic pole layer. 2. The thin film magnetic head according to claim 1, wherein an end opposite to the air lubrication surface is an end of the lower magnetic pole layer opposite to the air lubrication surface.   The distance from the end on the air lubrication surface side of the at least one heating element to the end surface of the head is within a range of 0.083 to 0.250 in terms of the height of the slider. Item 3. The thin film magnetic head according to Item 1 or 2.   The distance between the surface of the at least one heating element facing the slider and the surface of the magnetic pole portion opposite to the slider is specified by the height of the slider from 0.017 to 0.07. 4. The thin film magnetic head according to claim 1, wherein the thin film magnetic head is in a range of 040. 5.   The magnetic pole portion includes a lower magnetic pole layer, and an upper magnetic pole layer that is magnetically connected to the lower magnetic pole layer and is located on a side opposite to the slider of the lower magnetic pole layer. 5. The thin film magnetic head according to claim 4, wherein a surface opposite to the slider is a surface opposite to the slider of the upper magnetic pole layer.   6. The thin film magnetic head according to claim 1, wherein the at least one read magnetic head element is a giant magnetoresistive element or a tunnel magnetoresistive element.   7. The thin film magnetic head according to claim 1, the signal line to the at least one read magnetic head element and the at least one write magnetic head element of the thin film magnetic head, and the thin film magnetic head A head gimbal assembly comprising: a lead wire for supplying a current to the at least one heating element; and a support mechanism for supporting the thin film magnetic head.   8. A magnetic disk drive comprising at least one head gimbal assembly according to claim 7, further comprising current control means for controlling a current supplied to said at least one heating element.   The current control means is a control means for supplying a current to the at least one heating element during at least operation of the at least one read magnetic head element and / or the at least one write magnetic head element. Item 9. The magnetic disk device according to Item 8. The current control means has a heating element control signal system, and the heating element control signal system is an operation control signal system of the at least one read magnetic head element and / or the at least one write magnetic head element. 10. The magnetic disk device according to claim 8, wherein the current supplied to the heating element is controlled independently.

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