JP2006190473A - Magnetic head slider - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic disk device which allows a head element to be prevented from colliding with minute projections on a surface of a magnetic disk, and damage of the head element and thermal asperity to be reduced, even when temperature is increased. <P>SOLUTION: In this magnetic head slider, a magnetic head section 2 is provided with an electric conductive film 9 embedded in an insulating film and for heating a head element section 3. The electric conductive film 9 is formed so that a first film portion, and a second film portion formed on the plane where the first film portion is formed, folded back from the first film portion and adjoin the first film portion, become a pair. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a floating or sliding magnetic head slider on which a magnetic head for reading and writing information on a magnetic disk is mounted, and a magnetic disk device including the same.

  In order to meet the demand for higher recording density of magnetic disk devices, in recent years, the flying height of magnetic head sliders (also simply referred to as sliders) has been increasingly required. On the other hand, as the flying height of the slider progresses, collision between the R / W (Read / Write) element and the minute protrusion due to the roughness of the magnetic disk surface is likely to occur. In recent years, the flying height of a slider with respect to a magnetic disk has been reduced to 30 nm or less, and the collision probability between a minute protrusion on the surface of the magnetic disk and a magnetic head element (also simply referred to as a head element) has increased. When the head element collides with the minute protrusion, in the case of a magnetoresistive head, the element generates heat and an abnormal signal is generated due to thermal asperity (hereinafter abbreviated as TA). In general, a protective film such as carbon is attached to the surface of the head element to prevent damage such as corrosion. However, the protective film on the surface of the head element is worn due to a collision with a minute protrusion on the surface of the magnetic disk. As a result, the head element is not protected, and the head element is easily damaged, and the life of the magnetic disk is shortened.

  In Japanese Patent Application Laid-Open No. 10-269527, the magnetic head element structure is provided with a step which is concave with respect to the front slider, thereby avoiding collision between the minute protrusions on the magnetic disk and the element, and the magnetoresistive effect type. Means for preventing signal abnormality due to thermal asperity (TA) of the head is described.

Japanese Patent Laid-Open No. 10-269527

  When a magnetic signal is recorded / reproduced, a current flows through the magnetic head element, so the head element generates heat and the temperature rises. In addition, due to heat generated by the spindle motor or the like, the temperature of the entire magnetic disk housing increases, and the increased temperature may reach 60 ° C. On the other hand, in the head element portion, the magnetic head element is generally formed of a nickel-based alloy and a cobalt-based alloy, and the insulating film is formed of ceramics such as alumina. When the thermal expansion coefficient of the nickel-based alloy and cobalt-based alloy is larger than that of the ceramic of the insulating film and the temperature rises, the thermal expansion amount of the element is larger than that of the ceramic of the insulating film. Project in the direction of the surface.

The following calculates the amount of protrusion of an element as an example. The element material is a Ni—Fe alloy, and the linear thermal expansion coefficient δl / l is 1.45 × 10 ⁻⁵ / K. The length of the element in the slider thickness direction is 0.05.
mm. The insulating film is alumina, and the linear thermal expansion coefficient δl / l is 7.5 × 10 ⁻⁶ / K. Here, assuming that the temperature rise is 20 K and the element and alumina expand independently, the protrusion amount δl of the element is 7 nm (= 7.0 × 10 ⁻⁶ /K×20×0.05×10 ⁶ ). .

  In the technique described in Japanese Patent Laid-Open No. 10-269527, when the temperature rises greatly if the step between the head element portion and the front slider portion is small, the element portion is This is the lowest flying point (the closest point to the disk surface). As a result, the probability of colliding with a minute protrusion on the surface of the magnetic disk increases, and there arises a problem that signal damage due to element damage or thermal asperity occurs.

  Also, when the step between the head element and the front slider is large, or when used in a low temperature environment (for example, near 0 ° C.), the distance between the head element and the magnetic medium (magnetic spacing) increases when the slider floats. This causes a problem that recording / reproduction becomes impossible.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk device capable of preventing a collision between a head element and minute protrusions on a magnetic disk surface even when the temperature rises, and reducing damage to the head element and thermal asperity. It is in. It is another object of the present invention to provide a magnetic disk device capable of normal recording / reproduction even when it is subjected to changes in the environmental temperature such as the temperature inside the magnetic disk device or the outside air temperature.

  In order to achieve the above object, the magnetic head slider of the present invention floats on the magnetic disk by the rotation of the magnetic disk, and records information on the magnetic disk by the head element section formed on the magnetic head section mounted on the outflow end. In addition, in the magnetic head slider for reproducing information from the magnetic disk, the magnetic head portion includes an electrically conductive film embedded in an insulating film for heating the head element portion, and the electrically conductive film is a first film. And a second film portion formed on the surface on which the first film portion is formed and folded back from the first film portion so as to be adjacent to the first film portion. It is formed as follows.

  At this time, the first film portion and the second film portion are formed in the thickness direction of the slider, and a folded portion from the first film portion to the second film portion is defined as the magnetic disk of the slider. At the end of the first film portion and the second film portion opposite to the surface of the slider opposite to the magnetic disk, on the electrically conductive film. A wiring for applying a voltage may be connected.

  Further, the electrically conductive film is preferably provided in parallel with the head element portion interposed therebetween.

  According to the present invention, even if the temperature rises, the magnetic disk device or the magnetic head slider can prevent the head element from colliding with the minute projections on the magnetic disk surface, and can reduce damage to the head element and thermal asperity. Can provide.

  Further, it is possible to provide a magnetic disk device capable of normal recording / reproduction even with respect to changes in environmental temperature such as the temperature inside the magnetic disk device or outside air temperature.

  In addition, the first conductive film is formed on the surface on which the first film portion and the first film portion are formed so that the electric conductive film is folded back from the first film portion and adjacent to the first film portion. By forming the film portions to form a pair, a structure that does not generate a magnetic field that interferes with recording and reproduction when a voltage is applied can be obtained.

  Moreover, the temperature of the head element portion can be made uniform by providing the electrically conductive film in parallel with the head element portion interposed therebetween.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A magnetic head slider according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4 by taking a magnetoresistive head as an example.

  FIG. 1 is an enlarged side view of the magnetic head portion, and FIG. 2 is a side view of the magnetic head slider.

  FIG. 22 schematically shows the configuration of the magnetic disk device according to the present invention. FIG. 22 shows a perspective view of a magnetic head device 100 having a magnetic head slider 104 described below.

  In the magnetic disk device 101, a hub 103 to which a plurality of magnetic disks 101 rotating inside a casing (case) 111 is attached is rotated around a rotation shaft 102 by a spindle motor (not shown). A slider 104 positioned on the disk surface by the rotation of the magnetic disk 101 floats through a minute gap and is supported by the suspension 105.

  A gimbal (flexure) portion is provided at the front end side of the suspension 105 so that the slider 104 can be rotated around the front and rear and left and right axes. The gimbal portion is attached to the suspension 105 and supported by the slider 104. Has been.

  The suspension 105 is attached to the carriage 106 on the base side opposite to the slider 104, and the suspension 105 is supported on the magnetic disk. The carriage 106 is rotatably mounted around the pivot shaft 108 of the pivot portion 107 on the side opposite to the suspension, and is attached to and supported by a coil bobbin 109 provided on the other side of the carriage 106 with the pivot 107 interposed therebetween. The suspension 105 and the slider 104 are positioned on the magnetic disk 101 by the electromagnetic force applied to the coil by the voice coil motor 110 including the coil.

  Information on the disk is recorded or reproduced by a magnetic head mounted on a magnetic head slider 104 positioned on the magnetic disk 101, and a signal of the recorded / reproduced information is provided on a flexible printed circuit (FPC). The signal is transmitted to the outside of the magnetic head or the magnetic disk device through the signal line.

The configuration of this embodiment will be described. A magnetic head 2 is mounted at the outflow end of the slider 1. The head element unit 3 includes shield films 4a and 4b, a magnetoresistive read element 5, an insulating film 6, a coil 7, a magnetic core 8, and the like. Then, wirings 11 a, 11 b, 11 c, and 11 c are arranged in the vicinity of the magnetic head unit 2 or the element unit 3 with a predetermined interval so as to sandwich the head element unit 3.
Two electrically conductive films 9a and 9b that generate heat by application of voltage through 11d are formed substantially in parallel. As a control method, when the environmental temperature is low or the element temperature is low, a voltage or a current is applied to the electric conductive film to cause the electric conductive film to generate heat, thereby maintaining a constant appropriate element temperature. In addition, when the environmental temperature increases or when the element temperature increases due to recording / reproduction, the voltage or current applied to the electric conductive film is decreased to maintain an appropriate element temperature.

  Here, the heights of the disk-facing surface of the slider 1 and the disk-facing surface of the head element unit 3 are different, and the difference is called a processing step (PTR) 10. The processing step occurs when the air bearing surface is polished, and since the hardness of the head element portion 3 is lower than that of the slider 1, it is polished much and is recessed from the slider 1 surface.

  In the present embodiment, two electrically conductive films are not necessarily required, and may be one sheet. Further, two or more electric conductive films may be provided in order to uniformly apply temperature to the element portion.

  Moreover, as for the electrically conductive film material, it is sufficient that heat can be generated by applying a voltage, such as metal or semiconductor. For example, a nickel alloy or a cobalt alloy may be selected. The electrical resistance of the electrical conductive film may be selected as necessary, for example, 10Ω.

  Further, it is only necessary that the dimensions of the electric conductive films 9a and 9b can be arranged in the magnetic head 2. For example, the thickness may be 10 to 50 μm, the width may be larger than the width of the element, and the length in the slider thickness direction may be the same as that of the element. In the present embodiment, although an electrically conductive film is used, it may be a lump of electrically conductive material or a wire. In short, any material that generates heat so that the temperature of the element can be raised by voltage application. For example, an elongated continuous structure as shown in FIG. 3 may be adopted. Further, it is desirable that the electrically conductive film has a structure that does not generate a magnetic field that interferes with recording and reproduction when a voltage is applied.

  In the present embodiment, the electrically conductive films 9a and 9b are arranged in the longitudinal direction of the slider in front of and behind the head element. In short, any structure may be used as long as the structure can provide the amount of heat necessary for the element to rise to a predetermined temperature by voltage application.

  In FIG. 1 of the present embodiment, the electrically conductive film is embedded in the magnetic head portion, but the electrically conductive film 9e may be attached to the rear end portion of the head 2 as shown in FIG. In addition, as shown in FIG. 5, the electrically conductive films 9 f and 9 g may be attached to both sides of the head 2 corresponding to both end surfaces in the width direction of the slider 1.

  Next, the operation of this embodiment will be described with reference to FIGS.

  FIG. 6 is an example of a measurement result of the deformation amount of the head element 3 with respect to the disk surface (in the slider thickness direction) measured by changing the environmental temperature in a conventional magnetic head slider in which an electrically conductive film is not formed. . The displacement shown in FIG. 6 was normalized based on the ambient temperature of 25 ° C. FIG. 6 shows that when the environmental temperature is changed to 8 to 60 ° C., the amount of deformation of the head element (the amount of protrusion in the disk surface direction) reaches 5 nm or more.

  FIG. 7 shows the measurement of the amount of deformation of the head element 3 protruding in the disk surface direction by changing the head element temperature by energizing the coil of the write head in a conventional magnetic head slider in which no electrically conductive film is formed. It is an example of a measurement result. FIG. 7 shows that when the temperature of the magnetic head element is changed in the range of 25 to 125 ° C., the deformation amount of the head element reaches 13 nm or more.

  FIG. 8 shows the temporal change of the head element temperature when a 40 mA direct current is applied to the write coil. It takes about 1 s for the head element temperature to rise to a certain value after the current is applied.

  As shown in FIGS. 6 and 7, in the case of a conventional magnetic head in which the electrically conductive films 9a and 9b are not formed, when the temperature is low (for example, immediately after the start of recording), the magnetic head Since the element is recessed, the spacing between the magnetic head element and the recording medium increases, and writing may become impossible. For example, as shown in FIG. 8, if it is impossible to write for 1 s until the head element temperature rises, the normal recording speed is performed at a level of several mega (106) hertz to several hundred megahertz. The inability to record / reproduce corresponds to a loss of several megabytes or hundreds of megabytes of data.

  Further, when the temperature of the head element unit 3 is high due to an increase in environmental temperature or due to heat generation of the element itself, the head element approaches the disk surface as shown in FIG. Therefore, the protruding head element may collide with the minute protrusion 13 on the magnetic disk surface, and the head element may be damaged, or the signal may be abnormal due to the formation of thermal asperity. In other words, due to deformation of the element due to temperature within the operating temperature range of the head element, it is not possible to maintain a certain magnetic spacing, resulting in a recording / reproducing error at low temperature, damage to the element at high temperature, or thermal asperity. There are things to do.

  In the first embodiment, the magnetic head 2 is mounted at the outflow end of the slider 1. The head element unit 3 includes shield films 4a and 4b, a magnetoresistive reproducing element 5, an insulating film 6, a coil 7, a magnetic core 8, and the like. Then, two electric conductive films 9a that generate heat by applying voltage through 11a, 11b, 11c, and 11d in the vicinity of the magnetic head unit 2 or the element unit 3 with a predetermined interval so as to sandwich the head element unit 3 therebetween. 9b are formed substantially in parallel. As a method of controlling the amount of heat generated by the electric conductive films 9a and 9b, when the element temperature is low, a voltage or current is applied to the electric conductive film to cause the electric conductive film to generate heat and maintain a certain appropriate element temperature. This makes it possible to maintain an appropriate and constant spacing between the element and the recording medium, and to prevent a recording / reproducing error at a low temperature. Further, when the environmental temperature becomes high or the element temperature rises due to recording / reproduction, the voltage or current applied to the electric conductive film can be decreased to maintain a constant appropriate element temperature. This makes it possible to maintain an appropriate and constant spacing between the element and the recording medium, so that the head element does not collide with the minute protrusions on the magnetic disk surface, the head element is damaged, or the thermal asperity is reduced. It is possible to prevent signal abnormality due to formation.

  A second embodiment of the magnetic head slider of the present invention will be described with reference to FIGS. FIG. 10 is a side view of the magnetic head part in which a temperature sensor is attached to the rear part of the head. FIG. 11 is a side view of a magnetic head portion in which a temperature sensor is attached to the back surface of the head. FIG. 12 is a view seen from the back side of the magnetic head portion in which the temperature sensor is attached to the side surface of the head.

  The configuration of this embodiment will be described. In the present embodiment, in the configuration of the first embodiment of the present invention, a temperature sensor 14a is further provided at the rear portion of the magnetic head, and the voltage or current applied to the electrically conductive film is controlled using the temperature sensor. A control circuit 15 for controlling the temperature of the head element unit 3 is provided.

  In this embodiment, the temperature sensor 14b may be provided on the back surface of the magnetic head as shown in FIG. 11, or the temperature sensors 14b and 14c may be provided on the side surface of the magnetic head as shown in FIG. The position where the temperature sensor is provided is preferably near the head 2 or the element 3, but may be provided on the slider 1. Further, as a method of attaching the sensor, it may be attached, a thin film may be deposited, or it may be embedded in the head portion.

Next, the operation of this embodiment will be described. In the case of this embodiment, a temperature sensor 14a and a temperature control circuit 15 are provided in addition to the first embodiment. Therefore, the temperature of the head element can be controlled by controlling the voltage or current applied to the electric conductive films 9a and 9b by feedback control while constantly monitoring the temperature of the head element 3, and the temperature of the element and the recording medium at the low temperature can be controlled. It is possible to prevent a recording / reproducing error due to a large magnetic spacing, an element damage or a thermal asperity due to a small magnetic spacing between the element and the recording medium at a high temperature. Specifically, voltage (current) is applied to the electric conductive films 9a and 9b when the temperature of the magnetic head element is low, and application of voltage (current) is stopped when the temperature is high. As described above, in this embodiment, the temperature can be fed back by the temperature sensor, so that there is an advantage that the element position can be controlled more accurately than in the first embodiment.

  A third embodiment of the magnetic head slider of the present invention will be described with reference to FIGS. FIG. 13 is a side view of a magnetic head unit in which an electrically conductive film is connected to a load / unload (L / UL) control circuit. FIG. 14 is a flowchart of load / unload control.

  The configuration of this embodiment will be described. This embodiment is the same as the head configuration of the first embodiment of the present invention. When no current is applied to the head element 3 or the electrically conductive films 9a and 9b, the head element 3 has a head structure having a processing step (PTR). It has become. In the present embodiment, a load / unload mechanism is provided, and control of application of voltage or current to the electrically conductive film is controlled by an operation command for load / unload control of the magnetic head slider 1. Specifically, there is provided a control circuit 16 that reduces or stops the voltage or current applied to the electric conductive films 9a and 9b when the magnetic head slider 1 is loaded / unloaded.

  Next, the operation of this embodiment will be described. The feature of this embodiment is that a load / unload (L / UL) circuit is provided in addition to the first embodiment, and the heat generation of the electrically conductive film is controlled in conjunction with this. (Because the temperature sensor 14a and the temperature control circuit 15 are provided, the temperature of the head element 3 is controlled by controlling the voltage or current applied to the electric conductive films 9a and 9b by feedback control while constantly monitoring the temperature of the head element 3. Recording / reproducing error due to the large magnetic spacing between the element and the recording medium at low temperature, and element damage and thermal asperity due to the small magnetic spacing between the element and the recording medium at high temperature can be prevented.)

  In addition, application of voltage or current to the electric conductive film is controlled by an operation command for load / unload control of the magnetic head slider 1, and when the magnetic head slider 1 is loaded / unloaded, the voltage or electric current is applied to the electric conductive films 9a and 9b. A control circuit 16 for reducing the current or stopping the application is provided. For this reason, when the slider is loaded / unloaded, the thermal expansion of the head element is small and the processing step (PTR) can be maintained, so that the head element does not come into contact with the disk surface during loading / unloading. Can be prevented. As an example, a flowchart of slider load / unload control is shown in FIG. If the loading / unloading of the slider is controlled according to FIG. 14, there is no contact between the head element and the disk during loading / unloading, and damage to the head element can be prevented.

  Regarding the setting of the initial processing step (PTR) amount, it is desirable that the head element 3 does not protrude at the maximum use temperature. The maximum operating temperature of the head element section varies depending on the usage environment of the magnetic disk device, the heat generation of the spindle motor, the specifications of the head element itself, etc., but is generally between 40 and 80 ° C. Therefore, as shown in FIG. 6 or FIG. 7, it is desirable to set the initial PTR to 2 to 7 nm on the basis of room temperature (25 ° C.).

  Hereinafter, a fourth embodiment of the magnetic head slider of the present invention will be described with reference to FIGS. FIG. 15 is an enlarged side view of the magnetic head portion, and FIG. 16 is a side view of the magnetic head slider.

  The configuration of this embodiment will be described. A magnetic head 2 is mounted at the outflow end of the slider 1. The head element unit 3 includes shield films 4a and 4b, a magnetoresistive reproducing element 5, an insulating film 6, a coil 7, a magnetic core 8, and the like. Then, two thermal expansion films 17a and 17b are formed substantially parallel to the thickness direction of the magnetic head 2 or the slider 1 with a predetermined interval so as to sandwich the head element portion 3 therebetween. The thermal expansion films 17a and 17b are preferably formed at least in the main part below the center surface of the thickness of the magnetic head 2 or slider 1, that is, on the magnetic disk side.

As for the thermal expansion film material, for example, in the case of a nickel-based alloy having a linear expansion coefficient δl / l of the element material of 1.45 × 10 ⁻⁵ / K, a nickel alloy having a linear expansion coefficient equivalent to the element (δl / l About 1.45 × 10 ⁻⁵ / K) or a cobalt-based alloy (δl / l about 1.4 × 10 ⁻⁵ / K) may be selected. Further, as examples of dimensions of the thermal expansion films 17a and 17b, the thickness may be 10 to 50 μm, the width may be larger than the width of the element, and the length in the slider thickness direction may be the same dimension as the element. In this embodiment, the film is a film, but it may be a lump of a thermally expandable material, and in short, any element that deforms the magnetic head 2 in the disk surface direction by the heat expansion may be used.

  Next, the operation of this embodiment will be described with reference to FIGS. 17 and 18. As shown in FIG. 17, in the case of a magnetic head in which the thermal expansion films 17a and 17b are not formed, the head element moves toward the magnetic disk 10 due to thermal expansion due to heat generation of the element itself or a temperature rise of the head element unit 3. Protruding. The protruding head element collides with the minute projections 11 on the magnetic disk surface, and the head element is damaged or a signal abnormality occurs due to the formation of thermal asperity.

  In this embodiment, as shown in FIG. 18, since the thermal expansion films 17a and 17b are formed, the thermal expansion film is also formed together with the head element when the temperature of the magnetic head 2 rises or when the head element itself generates heat. It expands and the periphery of the head element portion is deformed. Therefore, the head element does not relatively protrude toward the magnetic disk, and a direct collision between the head element and the minute protrusion on the magnetic disk surface can be avoided. Therefore, it is possible to prevent signal abnormality due to damage to the head element or formation of thermal asperity.

  A fifth embodiment of the present invention will be described using a magnetoresistive head as an example with reference to FIGS. In FIG. 19, the configuration of the magnetic head 2 is the same as that of the first embodiment, and is omitted here. A thermal expansion film 17c is formed on the side of the disk 10 from the center surface of the slider or magnetic head in a substantially parallel manner with a predetermined distance from the head element unit 3 on the slider side.

  Next, the operation of this embodiment will be described with reference to FIG. In the case of this embodiment, even if the head element thermally expands due to the temperature rise of the magnetic head and protrudes toward the magnetic disk, the thermal expansion film 17c formed close to the slider also thermally expands, and the rear of the thermal expansion film is the disk Bent away from 10 As a result, the spacing between the head element portion 3 and the minute protrusions 11 on the disk 10 can be maintained, so that the collision between the head element and the minute protrusions can be avoided. Therefore, it is possible to prevent signal abnormality due to damage of each element or formation of thermal asperity.

The amount of deformation of the magnetic head 2 due to heat can be adjusted as necessary by selecting the material of the thermal expansion film 17 and adjusting the size and position of formation. As an example, the element material is a Ni—Fe alloy, the linear thermal expansion coefficient δl / l is 1.45 × 10 ⁻⁵ / K, the length of the head element in the slider thickness direction is 0.05 mm, the insulating film is alumina, A case where the linear thermal expansion coefficient δl / l is 7.5 × 10 ⁻⁶ / K will be described. When the temperature rise is 20 k, it has been found by calculation that the protrusion amount δl of the element is 7 nm. Therefore, in order to deform the same amount as the protrusion amount of the element, a pico slider with a slider thickness of 0.3 mm and a thermal When a thermal expansion film having an expansion coefficient δl / l of 2.9 × 10 ⁻⁵ / K is adopted, the thickness of the thermal expansion film may be 0.05 mm and the distance between the thermal expansion film and the element may be 0.15 mm. It will be.

  Next, another embodiment of the magnetic head slider according to the present invention will be described with reference to FIG. Since the configuration of the head element unit 3 is the same as that of the first embodiment, a description thereof is omitted here. In the direction closer to the slider 1 side than the head element unit 3 and at a predetermined distance from the head element unit 3 and in a direction substantially parallel and toward the magnetic disk surface of the slider, the slider center line of the slider thickness is closer to the disk 12 side. In addition to forming the thermal expansion film 9, the electric conductive wires 14 a and 14 b or the electric conductive film for applying a voltage to the thermal expansion film 9 were provided. The temperature of the thermal expansion film can be controlled by applying a voltage.

  In this embodiment, the thermal expansion film is provided inside the magnetic head film member 2 where the magnetic head element portion 3 is formed and in the vicinity of the element. Further, a thermal expansion film 9 is disposed along the joint surface between the magnetic head film member 2 and the slider body 1.

  The operation of the present embodiment will be described. The action of preventing damage to the head element and thermal asperity due to the thermal expansion of the thermal expansion film 9 is the same as that of the above-described embodiment, and is omitted here. However, by adjusting the voltage applied to the thermal expansion film 9, the expansion of the thermal expansion film can be adjusted to the amount expected for preventing element damage. For example, the control method may be the same as that of the fifth embodiment.

  A thermal expansion film 9 is provided along the joint surface between the magnetic head (film) 2 and the slider body 1, and the magnetic head element section 3 is disposed on the slider rear end side (air outflow end side) of the expansion film 9. Has been. Further, since the thermal expansion film 9 is arranged on the side of the slider in the thickness direction close to the magnetic disk, the protrusion amount of the head element unit 3 can be easily adjusted, and the magnetic head film member 2 is moved away from the disk 12. It can be easily deformed greatly.

  As is clear from the above description, according to the above embodiment of the present invention, the voltage or current applied to the electrically conductive film can be applied even when the environmental temperature increases or the element temperature increases due to recording / reproduction. By changing, it is possible to maintain a constant and appropriate element temperature, and by maintaining an appropriate and constant spacing between the element and the recording medium, the head element collides with a minute protrusion on the magnetic disk surface. In other words, it is possible to prevent the head element from being damaged or causing a signal abnormality due to the formation of thermal asperity.

  In addition, when the element temperature is low, a voltage or current is applied to the electric conductive film, the electric conductive film generates heat, and a constant appropriate element temperature is maintained, thereby maintaining an appropriate constant scan between the element and the recording medium. By maintaining pacing, recording / reproducing errors at low temperatures can be prevented.

  As described above, according to the present invention, even if the temperature rises, the head element can be prevented from colliding with the minute protrusions on the magnetic disk surface, and damage to the head element and thermal asperity can be reduced. A magnetic disk device or a magnetic head slider can be provided.

  Further, it is possible to provide a magnetic disk device capable of normal recording / reproduction even when it is subjected to changes in the environmental temperature such as the temperature inside the magnetic disk device and the outside air temperature.

It is an enlarged view of the magnetic head part of 1st Embodiment of the magnetic head slider which concerns on this invention. FIG. 2 is a side view of the magnetic head slider shown in FIG. 1. It is a figure which shows an example of the electrically conductive film of the magnetic head slider shown in FIG. It is the figure which affixed the electrically conductive film on the rear part of the head with respect to a slider advancing direction. It is the figure seen from the head rear part with respect to a slider advancing direction. This is an example of measuring the deformation of the head element with respect to a change in environmental temperature when an electrically conductive film is not formed. This is an example of measuring the deformation of the head element when the write coil is energized when the electrically conductive film is not formed. It is a figure which shows a time-dependent change of head element temperature, when 40-mA direct current is applied to a write coil. It is a figure which shows the state which collides with the magnetic head element protruded with the heat | fever, and the microprotrusion on a magnetic disc surface. It is a magnetic head part side view which affixed the temperature sensor on the rear part of the head. It is a side view of the magnetic head part which affixed the temperature sensor on the back surface of the head. It is the figure seen from the back surface of the magnetic head part which affixed the temperature sensor on the side surface of the head. It is a side view of the magnetic head part which connected the electroconductive film to the load / unload control circuit. It is a flowchart figure of slider load / unload control. It is an enlarged view of the magnetic head part of another embodiment of the magnetic head slider which concerns on this invention. FIG. 16 is a side view of the magnetic head slider shown in FIG. 15. 2 is a conceptual diagram in which a head element protrudes toward a magnetic disk 1 due to thermal expansion. FIG. It is a figure explaining the effect | action of the thermal expansion film of the magnetic head slider shown in FIG. It is an enlarged view of the magnetic head part of another embodiment of the magnetic head slider which concerns on this invention. It is a figure explaining the effect | action of the thermal expansion film | membrane of FIG. 19 of this invention. It is an enlarged view which shows the magnetic head part of another embodiment of the magnetic head slider which concerns on this invention. 1 is a perspective view showing a schematic configuration of a magnetic disk device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Slider, 2 ... Magnetic head, 3 ... Head element part, 4a, 4b ... Shield film, 5 ... Magnetoresistive reproducing element, 6 ... Insulating film, 7 ... Coil, 8 ... Magnetic core, 9a, 9b ... Electrical conduction Films, 11a, 11b, 11c, 11d ... wiring, 14a, 14b, 14c ... temperature sensor, 15 ... control circuit, 17a, 17b ... thermal expansion film, 100 ... magnetic disk device, 101 ... magnetic disk, 102 ... rotating shaft, DESCRIPTION OF SYMBOLS 103 ... Hub, 104 ... Slider, 105 ... Suspension, 106 ... Carriage, 107 ... Pivot part, 108 ... Pivot shaft, 109 ... Coil bobbin, 110 ... Voice coil motor, 111 ... Case (case).

Claims (3)

In a magnetic head slider that floats on a magnetic disk by the rotation of the magnetic disk and records information on the magnetic disk by a head element unit formed on the magnetic head unit mounted at the outflow end and reproduces information from the magnetic disk.
The magnetic head unit includes an electrically conductive film that is embedded in an insulating film and heats the head element unit,
The electrically conductive film is formed on the surface on which the first film portion and the first film portion are formed so as to be folded back from the first film portion and adjacent to the first film portion. A magnetic head slider characterized in that the two film portions are paired with each other. The magnetic head slider according to claim 1,
Forming the first film portion and the second film portion in the thickness direction of the slider;
A folded portion from the first film portion to the second film portion is provided on the surface of the slider facing the magnetic disk;
A wire for applying a voltage to the electric conductive film was connected to each end of the first film portion and the second film portion on the opposite side of the slider facing the magnetic disk. A magnetic head slider characterized by that. The magnetic head slider according to claim 1,
The magnetic head slider according to claim 1, wherein the electrically conductive film is provided in parallel with the head element portion interposed therebetween.

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