JP2013137857A - Head slider - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve long-distance drive by performing control of a floating amount between a disk and a head during operation of a storage device at a low voltage.SOLUTION: The head slider includes: a first column 202 and a second column 203 that are fixed on an end face of a slider substrate having the end face crossing with the floating surface, with the first column 202 and second column 203 mutually spaced in the in-plane direction of the floating surface; first actuating parts 218a-f fixed ends of which are fixed to the first column and that drive movable ends in the vertical direction of the floating surface; second actuation parts 318a-f fixed ends of which are fixed to the second column and that drive the movable ends in the vertical direction of the floating end; a bridge part 201 that is fixed to the movable ends of the first and second actuation parts and suspended between the first and second actuation parts; and a magnetic head provided on the bridge part.

Description

  The present invention relates to a head slider including a piezoelectric actuator for controlling a flying height.

  In recent years, miniaturization and precision of information equipment have been advanced. In a storage device that rotates a disk for storing information, floats a recording head on the surface of the disk, and reads / writes information on the disk, the recording density of the disk tends to increase. Since reading and writing are performed on a disk whose recording density is increasing, the distance between the head and the disk (the flying height) tends to be short. Particularly in a magnetic disk, the recording density is remarkably improved, and the current flying height is about 10 nm or less. In such a magnetic disk device with a small flying height, the influence of the flying height variation during the read / write operation of the magnetic head is large.

  In order to solve this problem, various micro-movement mechanisms for controlling the flying height have been proposed. As one method for controlling the flying height, for example, a method in which a heater circuit is mounted on a head slider and the recording head protrudes from the flying surface (the surface facing the disk) of the slider substrate using the thermal expansion of the recording head. Has been proposed. However, control using the heater circuit is binary control by turning the heater on and off. Also, there is a delay in the thermal response of the recording head, and it is difficult to perform the ejecting operation of the recording head at high speed.

  As another method for controlling the flying height, for example, a method using a piezoelectric element has been proposed. The piezoelectric element is deformed by energization, and the ejecting operation of the recording head is performed by the deformation of the piezoelectric element. The flying height control by the piezoelectric actuator can be continuously controlled, and can respond faster than the thermal actuator. However, a micro-movement mechanism that can eject the recording head at high speed, has a large amount of displacement per voltage applied to the piezoelectric body, and is easy to incorporate and design has not been developed.

JP 2005-11413 A JP 2000-348321 A

  It is an object of the present invention to provide a head slider that can maintain the distance between the disk and the head (the flying height) during the operation of the storage device, and can be easily assembled and designed.

According to one aspect of the invention,
A slider substrate having an end surface intersecting the air bearing surface; a first column and a second column fixed on the end surface in an in-plane direction of the air bearing surface; and a fixed end on the first column. A first actuating unit that is fixed and drives the movable end in the vertical direction of the air bearing surface, and a second actuating unit that has a fixed end fixed to the second column and drives the movable end in the vertical direction of the air bearing surface. A bridge portion fixed to the movable ends of the first and second operating portions and suspended between the first and second operating portions, and a magnetic head provided on the bridge portion. A head slider is provided.

  The head slider of the present invention can maintain the distance (flying height) between the disk and the head during operation of the storage device, and is easy to design and manufacture.

FIG. 2 is a plan view showing the inside of the magnetic disk device, and FIG. 2 is a diagram showing a schematic configuration of a circuit for controlling the magnetic disk device. It is a figure which shows schematic structure of the circuit which controls a magnetic disk apparatus. It is the figure which showed the magnetic head support body. It is a perspective view which shows schematic structure of the head slider of 1st and 2nd embodiment. FIG. 5 is a schematic cross-sectional view of a cross section A in the head slider of FIG. 4. It is typical sectional drawing for demonstrating a deformation | transformation of an action | operation part. FIG. 6 is a perspective view showing only the arrangement of electrodes, connecting portions, electrode wires, and electrode pads for the actuator of the head slider in FIGS. 4 and 5. FIG. 5 is a schematic cross-sectional view of a cross section A in the head slider of FIG. 4. It is a figure which shows a suspension. It is an example of a flowchart for controlling the flying height to be constant. It is sectional drawing which shows the manufacturing method of the head slider of 1st Embodiment. It is sectional drawing which shows the modification of the manufacturing method of the head slider of 1st Embodiment. It is the perspective view which showed the actuator which comprises the head slider of 2nd Embodiment. It is the perspective view which showed the shape of the action | operation part of the head slider of 2nd Embodiment. It is a cross-sectional schematic diagram which shows the actuator with a piezoelectric material which produces the displacement of d15 mode. It is a cross-sectional schematic diagram which shows a shape when a voltage is applied to the action | operation part of the actuator of FIG. It is a figure which shows structural parameters, such as a size of an actuator used by the 3rd and 4th simulation. It is sectional drawing which shows an example of the wiring pattern for supplying an electric potential to the electrode which comprises the action | operation part of the head slider of 2nd Embodiment. It is sectional drawing which shows the manufacturing method of the head slider of 2nd Embodiment. It is sectional drawing which shows the manufacturing method of the head slider of 2nd Embodiment. It is sectional drawing which shows the manufacturing method of the head slider of 2nd Embodiment.

-Magnetic disk unit-
A magnetic disk device (storage device) equipped with the head slider of the present invention will be described. FIG. 1 is a plan view showing the inside of the magnetic disk device, and FIG. 2 is a diagram showing a schematic configuration of a circuit for controlling the magnetic disk device.

  A magnetic disk device 101 shown in FIG. 1 is a hard disk drive (HDD), and has a housing 102 as an exterior. Inside the housing 102, a magnetic disk 104 mounted on the rotating shaft 103 and rotating, a slider 105 on which a magnetic head for recording and reproducing information on the magnetic disk 104 is mounted, and a suspension for holding the slider 105 106, a carriage arm 108 to which the suspension 106 is fixed and moved along the surface of the magnetic disk 4 about the arm shaft 107, and an electromagnetic actuator 109 for driving the carriage arm 108 are provided. Note that a cover (not shown) is attached to the housing 102, and the above-described components are accommodated in an internal space formed by the housing 102 and the cover.

  The magnetic disk device 101 further includes a control unit 110 that controls the operation of the magnetic disk device 101 as shown in FIG. The control unit 110 is mounted on a control board (not shown) provided inside the housing 102, for example. As shown in FIG. 2, the control unit 110 stores a CPU (Central Processing Unit) 112, a RAM (Random Access Memory) 114 for temporarily storing data processed by the CPU 112, a control program, and the like. A ROM (Read Only Memory) 115, an input / output circuit 119 for inputting / outputting signals to / from the outside, a bus 117 for transmitting signals between these circuits, and the like.

As shown in FIG. 2, the slider 105 has a head portion 105b formed on a slider substrate 105a. The head unit 105 b includes a head element 105 d provided with a recording magnetic pole for generating a recording magnetic field on the magnetic disk 104 and a sensor for reading magnetic information recorded on the magnetic disk 104. The head element 105d is connected to, for example, the input / output circuit 119 and the wirings 111a and 111b in the control unit 110, and records information (write operation) on the magnetic disk 104 and reproduces (reads) information stored on the magnetic disk 4. Operation). When performing this read operation or write operation, the carriage arm 8 is driven by the electromagnetic actuator 9 to move the head element 105 d to a desired track on the magnetic disk 104.

  Specifically, the read operation and the write operation are performed as follows. During the write operation, the control unit 110 inputs an electric signal (electric recording signal) to the head element 105d. The head element 105d applies a magnetic field corresponding to the recording signal to each minute area of the magnetic disk 104, and records the information carried in the recording signal (substituting the magnetization direction of each minute area). During the read operation, the head element 105d extracts information recorded in each minute area as an electric signal (electric reproduction signal) corresponding to the magnetization of each minute area.

  The CPU 112 controls the flying height of the magnetic head provided on the slider 105 with high accuracy by using the piezoelectric device provided at the bent portion of the suspension 106 to slightly displace the bending angle of the bent portion.

-Magnetic head support-
FIG. 3 is a view showing a magnetic head support (HGA). 3A is a perspective view of the magnetic head support, and FIG. 3B is a view of the magnetic head support as viewed in the X direction shown in FIG. As shown in FIG. 3, the direction perpendicular to the air bearing surface and away from the magnetic disk is defined as the Z direction, and the direction perpendicular to the X axis and the Z axis is defined as the Y direction. In the following drawings, the X axis, Y axis, and Z axis follow the directions of FIG.

  As shown in FIG. 3, the magnetic head support 120 generally refers to a structure in which the base plate 122 and the head slider 105 are attached to the suspension 106, but the state before the base plate 122 and the head slider 105 are attached, That is, only the suspension 106 may be called a magnetic head support. Further, a structure in which either the base plate 122 or the head slider 105 is attached to the suspension 106 may be referred to as a magnetic head support 120. Here, the suspension 106 is a plate-like member made of, for example, stainless steel having a thickness of 20 μm. A base plate 122 is joined to one end of the suspension 106 on the carriage arm 108 side, and a head slider 105 is attached to the other end (tip portion 106p). More specifically, for example, the head slider 105 is fixed to a gimbal 106 g provided at the tip 106 p of the suspension 106. The head slider 105 is disposed at a position facing the magnetic disk surface 104c. Further, an acceleration sensor 123 made of a piezoelectric material is provided on the suspension 106 in order to detect a variation in the flying height.

  Also, as shown in FIG. 3B, when the magnetic disk rotates in the direction of arrow C, an air flow is generated in the direction of arrow Air, and the air bearing surface 105f of the head slider (the surface facing the magnetic disk) 105f Air flows down. The lift force on the flying surface of the head slider due to the air flow balances with the force pressing the head slider toward the disk by the spring of the suspension. A head element 105d (not shown) provided with a recording magnetic pole for generating a recording magnetic field on the magnetic disk 104c in the head portion (not shown) and a sensor for reading magnetic information recorded on the magnetic disk 104c. The distance between the surface on the flying surface 105f side of the magnetic disk 104c and the magnetic disk 104c (the distance in the spacing direction S: the flying height) is kept constant.

-Head slider of the first embodiment-
FIG. 4 is a perspective view showing a schematic structure of the head slider according to the first embodiment.
As shown in FIG. 4, the actuator 105c is disposed at the end of the slider substrate 105a. A head portion 105b provided with a head element 105d is disposed on the opposite side of the slider substrate 105a with the actuator 105c interposed therebetween. That is, the head portion 105b is located on the opposite side of the slider substrate 105a with the actuator 105c interposed therebetween.

The slider substrate 105a is made of a ceramic such as an AlTiC (Al ₂ O ₃ —TiC) material. The Altic material is a fired product of alumina (Al ₂ O ₃ ) and titanium carbide (TiC).

  The head unit 105b is provided in the storage device for recording information on the storage medium or reproducing information on the recording medium. The head part 105b includes a head element 105d and an insulating part 37 provided around the head element 105d. The thickness of the head part 105b is, for example, about 30 μm.

  The head element 105d is an element provided for recording or reproducing information on a storage medium in the storage device. For example, examples of the element used in the magnetic disk device include a recording element having a function of writing information on a recording medium and a reproducing element having a function of taking out magnetic information recorded on the recording medium as an electric signal. The recording element includes, for example, a write coil, a main magnetic pole layer, and an auxiliary magnetic pole layer. The write coil has a function of generating magnetic flux. The main magnetic pole layer has a function of accommodating magnetic flux generated in the write coil and emitting the magnetic flux toward the magnetic disk. The auxiliary magnetic pole layer has a function of circulating the magnetic flux emitted from the main magnetic pole layer via the magnetic disk. Examples of the reproducing element include an MR element (magnetoresistance effect element). The head element 105d only needs to have at least one of the recording element and the reproducing element, and may have both of them.

  For example, as shown in FIG. 4, the head portion 105b is provided with external terminals 44 and 47 for applying a voltage to the actuator 105c.

The insulating portion 37 is provided to electrically and magnetically insulate between the actuator 105c and the head portion 105b and between a plurality of elements. The insulating portion 37 is a film made of an insulating material and having a thickness of about 1 to 50 μm, for example. Examples of materials that can be used for the insulating portion 37 include nonmagnetic and nonconductive materials such as metal oxides such as alumina (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), and titanium oxide (TiO ₂ ). It is done.

  The layer structure of the head portion 105b is not particularly limited, and a magnetic head used in the magnetic storage device can be provided in accordance with the application. The details of the layer configuration and manufacturing method of the head portion 105b are omitted in this specification.

  FIG. 5 is a schematic sectional view in section A of the head slider of FIG. An insulating layer 6z is provided between the actuator 105c and the slider substrate 105a. An electrode 33 is further provided between the insulating layer 6z and the slider substrate 105a. An insulating layer 34 is further provided between the slider substrate 105a and the actuator 105c for electrically insulating the slider substrate 105a.

  The actuator 105c has a function of controlling the distance between the storage medium 104 and the flying surface of the head element 105d by operating inside the storage device. The actuator 105c includes piezoelectric bodies 6a, 6b, 6c, and 6d (hereinafter sometimes collectively referred to as piezoelectric body 6), first electrodes 9a, 9b, 9c, and 9d (hereinafter collectively referred to as first electrode 9). The second electrodes 10a, 10b, 10c, and 10d (hereinafter sometimes collectively referred to as the second electrode 10), the resins 11a, 11b, 11c, 11d, and 11e (hereinafter collectively referred to as the resin 11). Is). The piezoelectric body 6 is sandwiched between a pair of electrodes including a first electrode 9 and a second electrode 10 having elasticity. The portions 18a, 18b, 18c, and 18d composed of the pair of electrodes 9 and 10 and the piezoelectric body 6 correspond to the operating portion (piezoelectric element) in the head slider of the present invention. Hereinafter, the portions 18a, 18b, 18c, and 18d may be collectively referred to as the operating portion 18.

  In the storage device, the surface facing the magnetic disk, that is, the air bearing surface 105f is usually polished to the position of the air bearing surface 105ff in FIG.

  The operating unit 18 applies a voltage perpendicular to the polarization direction of the piezoelectric body 6 to deform the operating units 18 a and 18 c based on the displacement of the d15 mode (piezoelectric shear effect), and applies a voltage in the polarization direction of the piezoelectric body 6. By doing so, it is comprised from the operation parts 18b and 18d which produce the deformation | transformation which applied the displacement of the d31 mode (piezoelectric lateral effect) of the piezoelectric material 6. FIG. 6 is a schematic cross-sectional view for explaining the deformation of the operating portion (piezoelectric element).

  FIGS. 6A and 6B are schematic cross-sectional views of the piezoelectric element 13a that causes displacement in the d15 mode. The piezoelectric body 6 is sandwiched between the electrodes 19 and 20. The electrodes 19 and 20 can apply an electric field EA to the piezoelectric body 6 in a direction crossing the polarization direction PA of the piezoelectric body 6. It is preferable that the electrodes 19 and 20 apply an electric field EA to the piezoelectric body 6 in a direction perpendicular to the direction of polarization PA of the piezoelectric body 6 from the viewpoint of increasing the deformation amount of the piezoelectric actuator 10. When the two electrodes 19 and 20 are given a potential difference, the piezoelectric body 6 generates d15 mode displacement (shear displacement). Even if both the polarization direction and the electric field application direction are reversed, the shear displacement direction is the same. If one of the polarization direction or the electric field application direction is reversed, the shear displacement direction is also reversed.

  FIGS. 6C and 6D are schematic cross-sectional views of the piezoelectric element 13b that generates displacement in the d31 mode. The piezoelectric body 6 is sandwiched between the electrodes 29 and 30. The electrode 29 has a function of changing the displacement direction of the piezoelectric body 6 by supporting the piezoelectric body 6. The electrode 29 is less likely to be deformed by an external force than the electrode 30. This difficulty of deformation can be quantitatively expressed by the product of the Young's modulus (elongation elastic modulus) of the electrode and the thickness. The electrode 29 and the electrode 30 are usually made of the same material because they are easy to manufacture. At this time, the electrode 29 is thicker than the electrode 30. The electrodes 29 and 30 can apply an electric field EB along the polarization direction PB of the piezoelectric body 6 to the piezoelectric body 6. Although the electric field EB causes a force to contract in the direction perpendicular to the electric field EB to the piezoelectric body 6, the electrode 29 and the electrode 30 try to restrain deformation of the piezoelectric body 6. Since the electrode 29 and the electrode 30 have higher rigidity than the electrode 29, the deformation amount is small on the side close to the electrode 29 of the piezoelectric body 6. As a result, the electrode 29 is deformed into a convex shape with the electrode 29 facing upward as shown in FIG. Even if both the direction of polarization and the direction of electric field application are reversed, the piezoelectric body 6 is subjected to a force of contracting in the same direction, so that the deformation is the same.

The piezoelectric body 6 is made of a piezoelectric material. Examples of the piezoelectric material that can be used for the piezoelectric body 6 include lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT) or lead lanthanum zirconate titanate ((Pb, La) (Zr, Ti). ) O ₃ : PLZT), Nb-added PZT, PNN-PZT {Pb (Ni, Nb) O ₃ -PbTiO ₃ -PbZrO ₃ }, PMN-PZT {Pb (Mg, Nb) O ₃ -PbTiO ₃ -PbZrO ₃ } and the like perovskite oxide. In addition to these materials, potassium niobate (KNbO ₃ ), aluminum nitride (AlN), or the like can be used.

  Examples of materials that can be used for the electrodes 19, 20, 29, and 30 (the first electrode 9 and the second electrode 10) include conductive materials. Examples include metals such as nickel (Ni), platinum (Pt), iridium (Ir), chromium (Cr), and copper (Cu), and nitrides such as titanium nitride (TiN) and tungsten carbide (WC). Such carbides or oxides such as indium tin oxide (ITO) can also be used.

  The head slider according to the first embodiment will be described with reference to FIG. 5 again. In the head slider according to the first embodiment, the substrate 105a is disposed at one end of the operating portion 18, and the head portion 105b is disposed at the other end. Actuators that generate d15 mode displacement and actuators that generate d31 mode displacement from the air bearing surface side of the actuator 105c are alternately arranged. The major surfaces of the piezoelectric bodies 6a and 6c included in the actuating portions 18a and 18c that generate the d15 mode displacement are the main surfaces of the piezoelectric bodies 6b and 6d included in the actuating portions 18b and 18d that generate the d31 mode displacement. And substantially parallel to the air bearing surface 105f. In other words, the main surface of the piezoelectric body that generates the d15 mode displacement and the main surface of the piezoelectric body that generates the d31 mode displacement are arranged to face the air bearing surface.

  The first electrode 9 and the second electrode 10 are provided so as to be adjacent to the main surface of each operating portion 18. Of the electrodes included in the d31 mode operating portions 18b and 18d, the second electrodes 10b and 10d far from the air bearing surface are thicker than the first electrodes 9b and 9d, respectively. On the other hand, the relationship between the thicknesses of the first electrodes 9a and 9b and the second electrodes 10a and 10b included in the d15 mode operating portions 18a and 18b is not particularly limited, and the thicknesses of the first electrodes 9a and 9b The thickness of the second electrodes 10a and 10b may be the same or different.

  The piezoelectric bodies 6a and 6c constituting the operating portions 18a and 18c that generate the d15 mode displacement are previously polarized in the direction from the ceramic substrate 105a toward the head portion 105b. The piezoelectric bodies 6b and 6d included in the actuating portions 18b and 18d that generate the d31 mode displacement are normally polarized in the same direction when the piezoelectric bodies 6a and 6c are polarized. However, when an electric field higher than anti-electrolysis is applied from the first electrode 9b to the second electrode 10b, the direction from the first electrode 9b to the second electrode 10b (crossing the direction from the ceramic substrate 105a to the head portion 105b). Can be polarized in the direction.

  The piezoelectric bodies 6a and 6c that generate the d15-mode displacement and the piezoelectric bodies 6b and 6d that generate the d31-mode displacement are in-plane in which the actuator of the slider substrate 105a is provided in the head portion 105b with reference to the slider substrate 105a. The displacement S is generated in substantially the same direction.

  The resin 11 is disposed between the adjacent operating portions 18. (For example, the resin 11b is disposed between the operating portions 18a and 18b.) The resin 11 has electrical insulation, is made of a material other than the piezoelectric material, and includes the first electrode 9 and the first electrode 9. Those that are easier to deform (higher flexibility) than the two electrodes 10 and the piezoelectric body 6 are preferable. Examples of materials that can be used for the resin 11 include urethane, polyimide, epoxy, and aramid resin, and a polyimide resin is preferably used from the viewpoint of heat resistance. In addition, materials other than resin can be used as long as the insulating material has a Young's modulus lower than that of the piezoelectric body. For example, ceramics containing a lot of fine bubbles such as foam glass may be used. Further, the resin 11 may be a gap.

  In order to apply a potential to the first electrode 9 and the second electrode 10, wirings (not shown) such as vias electrically connected to the first electrode 9 and the second electrode 10 are provided. From the point that the wiring is not complicated, the second electrode 10a and the first electrode 9b, the second electrode 10b and the first electrode 9c, and the second electrode 10c and the first electrode 9d are electrically connected by the connecting portions 21a, 21b, and 21c, respectively. Are preferably connected. In addition, an electric field higher than anti-electrolysis, which is an electric field necessary for changing the polarization direction, is applied to the piezoelectric bodies 6b and 6d that generate the d31 mode displacement, and the piezoelectric bodies 6a and 6c that generate the d15-mode displacement are more than anti-electrolytic. In order not to apply an electric field, the length in the direction perpendicular to the air bearing surface of the piezoelectric bodies 6b and 6d that generate the d31 mode displacement is preferably smaller than that of the piezoelectric bodies 6a and 6c that generate the d15 mode displacement. More preferably, it is 1/2 or less of that of the piezoelectric bodies 6a and 6c.

  7 shows only the arrangement of the first electrode 9, the second electrode 10, the connecting portions 21a to 21c, the electrode lines 15 and 16, and the electrode pads 14 and 17 with respect to the actuator 105c of the head slider in FIGS. FIG.

  The electrode pad 14 is electrically connected to an external terminal 44 (not shown) in FIG. The electrode line 15 is electrically connected to the electrode pad 14. The electrode line 15 branches at a plurality of locations and is electrically connected to the first electrode 9a, the connection portion 21b, and the second electrode 10d. The potential from the control unit 110 is supplied to the first electrode 9a, the second electrode 10b, the first electrode 9c, and the second electrode via the wiring formed on the suspension, the external terminal 44, the electrode pad 14, and the electrode line 15. 10d.

  The electrode pad 17 is electrically connected to an external terminal 44 (not shown) in FIG. The electrode line 16 is electrically connected to the electrode pad 17. The electrode wire 16 branches at a plurality of locations and is electrically connected to the connection portion 21a and the connection portion 21c. The potential from the control unit 110 is supplied to the second electrode 10a, the first electrode 9b, the second electrode 10c, and the first electrode via the wiring formed on the suspension, the external terminal 44, the electrode pad 14, and the electrode line 15. 9d.

  When a ground side potential is supplied to the electrode pad 14 and a bias side potential is supplied to the electrode pad 17, an electric field E in the direction shown in FIG. 5 is applied to each of the piezoelectric bodies 18a to 18d. The main displacement direction of the actuator that generates the displacement in the d15 mode and the main displacement direction of the actuator that generates the displacement in the d31 mode are the spacing directions S shown in FIGS. 3 and 5.

  The head slider according to the first embodiment will be described again with reference to FIG. As described above, the substrate 105a is made of hard Altic. The thickness (the length in the Y direction) is about 1 mm. On the other hand, the head portion 105b is made of various metal oxides and metals, but mainly includes a material softer than AlTiC. The thickness (the length in the Y direction) is usually about several tens of μm, which is very thin compared to the substrate 105a. Therefore, as shown in FIG. 6, when the operating portions 18a to 18d are respectively deformed, the substrate 105a side is fixed to the substrate 105a so that the shape hardly changes, whereas the head portion 105b side is changed to the floating surface 105f. Large displacement in the vertical direction. Inside the storage device, the head unit 105b is largely displaced in the direction between the recording / reproducing element and the magnetic disk medium (spacing direction: arrow S direction in FIG. 3). Therefore, the distance (flying height) between the head element 105d of the head portion 105b and the storage medium 104 is controlled by the displacement amount in the arrow S direction at the portion B on the flying surface 105f side and the head portion 105b side of the actuator 105c. Can be controlled by.

  As a comparative embodiment, an actuator composed only of an operating part that generates a displacement in d15 mode can be mentioned. Since this actuator has a large amount of displacement per unit electric field applied to the piezoelectric body, the length in the direction from the slider substrate 105a to the head portion 105b (the length in the Y direction) is, for example, about 4 to 6 μm. A displacement amount in the S direction can be obtained. In order to mount this actuator, due to the nature of the piezoelectric effect, the polarization directions of adjacent piezoelectric bodies are alternately reversed, or the polarization directions of adjacent piezoelectric bodies are aligned in one direction, and the electrodes sandwiching each piezoelectric body are patterned. Must be independent. In the former, since the polarization component (particularly the polarization component in the direction opposite to the polarization PA in FIG. 5) generated during the manufacture of the head slider gradually decreases, the displacement amount in the S direction gradually decreases. In the latter case, the polarization component generated during the production of the head slider may be gradually reduced as in the former case. Further, the latter actuator needs to electrically insulate the electrode 9 and the electrode 10 in order to drive the operating portion. From the viewpoint of ensuring the insulation between the electrode 9 and the electrode 10, a patterning step for removing the connecting portion 21a is required at the time of manufacture. This patterning process is difficult to realize if the interval (pitch) between the piezoelectric bodies is narrow.

  Further, as another comparative embodiment, an actuator composed only of an operating part that generates a d31 mode displacement can be cited. This actuator is suitable for the use of a head slider over a long period of time because there is no fear of a decrease in the amount of polarization because the direction of polarization of the actuator is the same as the direction of the electric field required to cause displacement. However, since the amount of displacement per unit electric field applied to the piezoelectric body is small, the length in the direction from the slider substrate 105a toward the head portion 105b is sufficient to cause sufficient displacement in the S direction with an applied voltage of, for example, about 10 to 30V. It is necessary to increase (the length in the Y direction) to about 20 to 30 μm, for example. The width (length in the direction perpendicular to the air bearing surface: length in the Z direction) of the piezoelectric body that causes the d31 mode displacement is, for example, about 0.5 to 2 μm. Since the length in the direction from the slider substrate 105a to the head portion 105b is larger than the width of the piezoelectric body, when the piezoelectric body is formed by an etching process in the manufacturing process of the head slider, the piezoelectric body has high shape accuracy. Difficult to form.

  In the head slider according to the present embodiment, since the actuators that generate the d15 mode displacement and the actuators that generate the d31 mode displacement are alternately arranged as shown in FIG. 5, the electrode 9 and the electrode 10 are manufactured at the time of manufacture. No patterning process is required to ensure the insulation. Further, since the patterning step is unnecessary, the interval (pitch) between the piezoelectric bodies can be reduced. Therefore, the obtained head slider is small and has high driving force. Such a head slider is suitable for long-term use.

  In addition, the head slider of this embodiment has a d15 mode displacement in the direction from the slider substrate to the head portion of the piezoelectric body, even though the actuator includes 50% of the actuator that generates the d31 mode displacement. Even if it is almost the same as the actuator composed of only the actuating part that is generated, the displacement amount in the spacing direction is comparable to that of the actuator composed of only the actuating part of the d15 mode. Accordingly, when the shape of the piezoelectric body is formed by an etching process in the head slider manufacturing process, a piezoelectric body with high shape accuracy can be formed.

  FIG. 8 is a cross-sectional view of a head slider similar to FIG. For example, with respect to a head slider including a head portion 105b, an actuator 105c, and an AlTiC substrate 105a as shown in FIG. 8, the amount of displacement in the spacing direction (Z direction) at point B1 when an electric field of 10 V is applied between the electrodes is simulated. Determined by Note that the air bearing surface 105f of the head slider is polished to the position of the air bearing surface 105ff. The direction of polarization and the direction of applying an electric field are the same as those of the head slider of FIG. 5, but are not shown.

(First simulation)
Twenty-five d15 mode operating parts and 24 d31 mode operating parts were alternately arranged. The height of the actuator 105c (H1 in FIG. 8) was 4 μm. In the d15 mode operating portion, the piezoelectric body 6a has a width (W6a in FIG. 8) of 2 μm, a height (H1 in FIG. 8) of 4 μm, and a length (length in the X-axis direction in FIG. 8) of 500 μm. In the d31 mode operation section, the piezoelectric body 6b has a width (W6b in FIG. 8) of 1 μm, a height (H1 in FIG. 8) of 4 μm, and a length (length in the depth direction in FIG. 8) of 500 μm. The second electrode 10b provided in the d31 mode operation unit has a width (W10b in FIG. 8) of 1 μm, a height (H1 in FIG. 8) of 4 μm, and a length (length in the depth direction in FIG. 8) of 500 μm. Have The first electrode 9a, the second electrode 10a provided in the d15 mode operating part, and the first electrode 9b provided in the d31 mode operating part have a width (W9a, W10a, W9b in FIG. 8) of 150 nm and a height (FIG. H1 in FIG. 8 has a size of 4 μm and a length (length in the depth direction in FIG. 8) of 500 μm.

  Other operating parts that cause d15 mode displacement other than the operating part 18a have the same size as the operating part 18a. Other operating parts that cause the d31 mode displacement other than the operating part 18b have the same size as the operating part 18b. The resin 11 has a width (W11b in FIG. 8) of 2 μm, a height (H1 in FIG. 8) of 4 μm, and a length (length in the depth direction in FIG. 8) of 500 μm, excluding the resin exposed on the air bearing surface. Have. The total height of the insulating layer 35 and the head portion 105b (H2 in FIG. 8) was 30 μm.

  The displacement in the spacing direction at point B when an electric field of 10 V was applied between the electrodes was 3.6 nm.

(Second simulation)
A simulation was performed for a head slider similar to the head slider of the first simulation except that the portion where the resin 11 was provided was a gap. The amount of displacement in the spacing direction at point B when an electric field of 10 V was applied between the electrodes was 3.8 nm.

(Comparison simulation)
A simulation was performed for a head slider similar to the head slider of the first simulation, except that 49 d15 mode operating parts were replaced. The displacement in the spacing direction at point B when an electric field of 10 V was applied between the electrodes was 5.4 nm. In this structure, the polarization direction must be aligned in one direction, and each drive electrode of the piezoelectric body must be made independent by patterning, and it is extremely difficult to manufacture a 4 μm pitch piezoelectric body, which is the design value of the simulation.

  Since the head slider of the present embodiment has a small length in the direction from the slider substrate to the head portion, the shape of the portion moved by the actuator, that is, the shape of the head portion and the actuator portion is small, and the resonance frequency of the portion is high. Therefore, the drive frequency of the operating part can be set high. When the resonance frequency of the part moved by the actuator is close to the drive frequency for driving the operating part, the normal driving of the operating part may be hindered by the resonance of the part moved by the actuator. Therefore, in order to be able to perform control without being affected by such influence, the operating portion is driven at a frequency lower than the resonance frequency of the portion moved by the actuator. Therefore, if the drive frequency of the operating unit can be set high, the flying height of the magnetic head can be controlled at high speed.

  In the present embodiment, resin is provided between the operating portion 18a and the operating portion 18b, between the operating portion 18b and the operating portion 18c, and between the operating portion 18c and the operating portion 18d. Similarly to the first electrode and the second electrode, the portion may be formed of a conductive material. At this time, the second electrode 10a and the first electrode 9b are integrated, the second electrode 10b and the first electrode 9c are integrated, and the second electrode 10c and the first electrode 9d are integrated. In the head slider of this aspect, although the deformation amount of the actuator 105c is smaller than that in the above embodiment in which resin is provided between the operating parts, the deformation amount of the piezoelectric element is reduced in long-term use as in the above embodiment. There are few, and the design and manufacture are easy.

  As in the head slider of this embodiment, it is preferable from the viewpoint of the stability of the operation and the durability of the actuator that the actuators that cause the displacement of the d15 mode and the d31 mode are alternately arranged in order from the air bearing surface side. It is not always necessary to arrange them alternately. In addition, the actuator only needs to include at least one operating unit that generates d15 mode displacement and at least one operating unit that generates d31 mode displacement. Further, as in the head slider of the present embodiment, the proportion of the d15 mode operating portion is not limited to 50%. From the standpoint of enduring long-term use and easy design and manufacture, the proportion of the d15 mode operating portion is preferably 40 to 60%.

  Hereinafter, the head slider of the first embodiment will be described with reference to FIG. 5 again.

An insulating layer 6z is provided between the actuator 105c and the slider substrate 105a. The insulating layer 6z has a function of preventing an electrical short circuit between the slider substrate 105a made of a conductive material such as Altic and the first electrode 9 or the second electrode 10. The material that can be used for the insulating layer 6z is not particularly limited as long as it has insulating properties. For example, in addition to the piezoelectric material used for the piezoelectric body 6 described later, alumina (Al ₂ O ₃ ) or oxidation titanium (TiO _2), and the like. In particular, as shown in the head slider manufacturing method described later, an insulating layer can be provided without increasing the number of manufacturing steps, so that the piezoelectric material used for the piezoelectric body 6 is integrated with the piezoelectric bodies 6a to 6d. It is preferable to provide them.

An electrode 33 may be further provided between the insulating layer 6z and the slider substrate 105a. The electrode 33 is provided to apply an electric field that causes the piezoelectric body to generate polarization in a direction from the slider substrate 105a toward the head unit 105, which is necessary for an operating unit to be described later to generate a d15 mode displacement. In the head slider of this embodiment, the electrode provided on the opposite side of the electrode 33 across the actuator 105c is removed during the manufacturing process and does not exist. Examples of the material of the electrode 33 include a high melting point metal such as platinum (Pt), a chemically stable noble metal such as gold (Au) and iridium (Ir), strontium ruthenate (SrRuO ₃ ), titanium nitride (TiN), and the like. Is mentioned.

An insulating layer 34 for electrically insulating the slider substrate 105a and the actuator 105c may be provided between the slider substrate 105a. The insulating layer 34 is a film made of an insulating material having a film thickness of 500 nm, for example, and is formed on the end surface of the slider substrate 105a as shown in FIG. Examples of materials that can be used for the insulating layer 34 include alumina (Al ₂ O ₃ ) and titanium oxide (TiO ₂ ). By providing such an insulating layer 34, the slider substrate 105a can be completely insulated from the electrode of the actuator 105c, and noise on the actuator 105c side can be prevented from leaking to the slider substrate 105a.

  In the head slider of this embodiment, the insulating layer 34 and the electrode 33 are provided. However, the insulating layer 6z and the actuator 105c may be provided on the conductive slider substrate 105a such as Altic without providing them. Good. In this case, the ceramic substrate 105a is used as an electrode for applying the polarization necessary to cause the d15 mode displacement.

An insulating layer 35 is provided between the actuator 105c and the head element 105d for electrically insulating the actuator 105c and the head element 105d. The insulating layer 35 is a film made of an insulating material having a film thickness of 500 nm, for example. Examples of materials that can be used for the insulating layer 35 include alumina (Al ₂ O ₃ ) and titanium oxide (TiO ₂ ).

  An example of a method for controlling the flying height in the magnetic disk device will be described with reference to FIGS. FIG. 9 is a view showing the suspension 106. FIG. 9A is a side view of the suspension, and FIG. 9B is a plan view of the suspension viewed from the air bearing surface 105f side.

  In parallel with the wirings 111a and 111b connecting the head element 105d and the input / output circuit 119, wirings 111c and 111d for voltage control supplied to the actuator 105c are arranged. An acceleration sensor 123 made of a piezoelectric element is mounted on the suspension 106. The acceleration sensor 123 is connected to the input / output circuit 119 via wirings 111e and 111f.

  When the flying height fluctuates, the acceleration sensor 123 outputs a voltage signal. The output voltage signal is amplified by an operational amplifier (amplifying circuit) 118 via wirings 111e and 111f and an input / output circuit 119. The amplified signal is input as the operating voltage of the actuator 105c via the wirings 111c and 111d.

  FIG. 10 is an example of a flowchart for controlling the flying height to be constant. The CPU 112 causes the magnetic head 105 to seek to the reading or writing position on the magnetic disk 104 (S101). During the seek operation, the flying height variation is sensed by the acceleration sensor 123 (S102). When the acceleration sensor outputs a voltage due to the fluctuation of the flying height (S103), an operating voltage is applied to the actuator 105c (S104). At this time, the actuator 105c operates to cancel the fluctuation of the flying height, and keeps the flying height constant. Thereafter, a read or write operation is performed (S105). Steps 102-105 are repeated until the read or write operation is completed. When the read or write operation is completed, the operation again moves to the seek operation (S101).

  In this way, the actuator 105c can be finely driven according to the fluctuation of the flying height, and as a result, the flying height can be kept constant. Specifically, the air bearing surface of the slider (105f in FIG. 3B) and the storage medium (FIG. 3B) due to various factors such as changes in atmospheric pressure, thermal expansion, impact due to head crashes, and vibration caused by the motor of the storage device. It is possible to easily correct the flying height in accordance with the change in the distance between 104 c) and b). Furthermore, the flying height can be stabilized in response to high-speed fluctuations caused by the flying height of the disk during one rotation due to the undulation of the magnetic disk, local unevenness, and rotation of the rotating shaft.

-Manufacturing Method of Head Slider of First Embodiment-
FIG. 11 is a cross-sectional view illustrating the method of manufacturing the head slider according to the first embodiment. In the following description, the thickness means the length in the direction in which the film is deposited on the substrate (Y direction).

On the AlTiC substrate 105a, an insulating layer 34 (thickness 500 nm, Al ₂ O ₃ ), a lower electrode 33 (150 nm, Pt / Ti), a piezoelectric body 6 (thickness 5 μm, PZT), an upper electrode 43 (thickness 150 nm, Al ) Is formed by sputtering (FIGS. 11 (1) to (4)). The piezoelectric body 6 is formed at a high temperature (500 to 700 ° C.) for crystallization. The lower electrode 33 may be a noble metal such as Ir, and the piezoelectric body 6 may be a piezoelectric material other than PZT, such as PLZT. The upper electrode 43 is preferably made of Al that can be patterned by wet etching.

Next, a polarization process is performed by applying a voltage between the upper electrode 43 and the lower electrode 33. Upper electrode 4
If 3 is Al, it may be removed by wet etching after the end of polarization. Next, the mask is patterned using photolithography, and the piezoelectric body 6 is etched by dry etching (
FIG. 11 (5)).

Next, a plating seed layer of 300 nm (Cu / Cr) is formed by sputtering, and further copper (Cu) plating is performed, and the grooves formed by etching are filled with copper to be the first electrode 9 and the second electrode 10 ( FIG. 11 (6)). Next, the surface of the surface of the piezoelectric body 6 and the upper surface thereof are planarized by polishing (FIG. 11 (7)). Further, the copper existing in the portion where the resin 11 is provided is dry-etched (FIG. 11 (8)). The resin 11 is filled in the groove 49 formed by etching (FIG. 11 (9)), and the surface of the piezoelectric body 6 is surfaced by polishing (FIG. 11 (10)). After forming the insulating layer 35 (thickness 500 nm, Al ₂ O ₃ ) on the surface, the head portion 105b is formed (FIG. 11 (11)).

  FIG. 12 is a cross-sectional view showing a modification of the method of manufacturing the head slider according to the first embodiment. Up to FIG. 12 (8), the same steps as in FIG. 11 (8) are performed. Thereafter, it is bonded to the upper surface of the piezoelectric body 6 using a substrate 48 such as Si (FIG. 12 (9)). An adhesive may be used for bonding, but a surface activated bonding method or the like is desirable. Alternatively, eutectic bonding may be used by sputtering Au / Sn on the bonding surface. The groove 49 is left as it is.

Next, the thickness of the substrate 48 is reduced by polishing, and further reduced to about 10 μm by etching (FIG. 12 (10)). An insulating layer 35 (500 nm, Al ₂ O ₃ ) is formed thereon, and then a head portion 105b is formed (FIG. 12 (11)).

  The head slider is used after being polarized in a direction parallel to the interelectrode direction by applying an electric field higher than the coercive electric field between the electrodes 9 and 10 adjacent to the piezoelectric body 6 causing the d31 mode displacement. To do.

-Head slider of the second embodiment-
The head slider of the second embodiment has a schematic structure similar to the schematic structure of the head slider of the first form shown in FIG. The structure of the actuator 105c is different between the head slider of the second embodiment and the head slider of the first embodiment. In the following description, the structure of the actuator 105c will be mainly described, and description of portions overlapping with those of the first embodiment will be omitted.

FIG. 13 is a perspective view showing only the actuator 105c of the head slider according to the second embodiment. The head slider shown in FIG. 13 is a view of the actuator 105c viewed from the same direction as the perspective view of FIG. The actuator 105 c includes a first pillar 202, a second pillar 203, a bridge part 201 having both ends attached to the first pillar 202 and the second pillar 203, and a plurality of parts provided between the first pillar 202 and the bridge part 201. First operating parts 218a to 218f (hereinafter may be collectively referred to as first operating part 218) and a plurality of second operating parts 318a to 318f (hereinafter referred to as the first operating part 218 and the bridge part 201). And may be collectively referred to as a second operating unit 318). In addition, although the six 1st action | operation parts 218 and the 2nd action | operation parts 318 are each provided, at least one each should just exist. The first pillar 202 and the second pillar 203 exist in the upper left direction of the first pillar 202 and the second pillar 203 in FIG. 6 and are adjacent to the slider substrate 105a (not shown). On the other hand, a gap 204 is provided between the first operating part 218, the second operating part 318, and the bridge part 201 and the ceramic substrate 105a. Moreover, the bridge part 201 exists in the lower right direction of the bridge part 201 in FIG. 6, and is adjacent to the head part 105b which is not illustrated. On the other hand, a gap 205 is provided between the first pillar 202 and the first operating part 218 and the head part 105b, and a gap 305 is provided between the second pillar 203 and the second operating part 318 and the head part 105b. It has been.

  FIG. 14 is a perspective view showing the shape of the first operating portion 218 of the head slider according to the second embodiment. 14 is a view as seen from the same direction as the perspective view of FIG. The first operation unit 218 includes a piezoelectric body 206 and a pair of electrodes 209 and 210 for applying an electric field to the piezoelectric body 206. The main surfaces of the piezoelectric body 206 and the electrodes 209 and 210 are arranged so as to face the air bearing surface (the air bearing surface 105f in FIG. 4). The piezoelectric body 206, the electrode 209, and the electrode 210 correspond to the piezoelectric body 6, the electrode 9, and the electrode 10 of the first embodiment, respectively. In the second embodiment, the operating unit 218 may cause a d15 mode displacement or a d31 mode displacement. The shape of the operating portion according to the drive mode and the direction in which the displacement is generated, the direction of polarization of the piezoelectric body, and the direction of application of the electric field to the piezoelectric body are as described with reference to FIG. The driving modes of the plurality of first operating parts 218 may be the same or different from each other. Further, the second operating part 318 can have the same shape as the first operating part 218. The driving modes of the plurality of second operating units 318 may be the same or different.

  In order to stabilize the operation of the bridge unit 201, it is preferable that the plurality of first operating units 218 and the plurality of second operating units 318 have the same shape.

  FIGS. 15A and 15B are schematic cross-sectional views showing an actuator having a piezoelectric body (active portion) that generates a displacement of d15 mode (piezoelectric shear effect). The deformation | transformation of the actuator of 2nd Embodiment is demonstrated using FIG. FIG. 15A shows the actuator 105c viewed from the head element 105d side, and FIG. 15B shows the actuator 105c viewed from the upper side (Z-axis direction) of the head slider. The actuating part 218 has a polarization P1 from the first pillar 202 toward the bridge part 201, and the actuating part 318 has a polarization P2 from the second pillar 203 towards the bridge part 201.

  FIGS. 16A and 16B are schematic cross-sectional views showing shapes when a voltage is applied to the actuators 218 and 318 of the actuator of FIG. 16A shows the actuator 105c viewed from the head element 105d side, and FIG. 16B shows the actuator 105c viewed from the upper side (Z-axis direction) of the head slider. As shown in FIG. 16A, an electric field E1 is applied to the operating unit 218, and an electric field E2 is applied to the operating unit 318. Then, the operating parts 218 and 318 cause the displacement in the d15 mode described in FIGS. 6 (a) and 6 (b). The first pillar 202 and the second pillar 203 are fixed to a slider substrate 105a (not shown). On the other hand, a gap 204 is provided between the first operating part 218, the second operating part 318, and the bridge part 201 and the slider substrate 105a. Therefore, the bridge part 201 is displaced in the −Z direction with respect to the first pillar 202 and the second pillar 203. When the electric field application direction or the polarization direction is reversed, the bridge portion 201 is displaced in the + Z direction with respect to the first column 202 and the second column 203.

  Gaps 211 and 311 are provided between the operating portions 218 and 318, respectively. When the actuator 105c has insufficient strength to support the head portion 105b, reinforcing members such as alumina may be provided in the gaps 211 and 311.

(Third simulation)
The displacement of the head slider according to the second embodiment was simulated. A finite element simulation (ANSYS 11.0) was used as a calculation tool. Structural parameters such as the size of the actuator used in the simulation will be described with reference to FIG. 17A shows the actuator 105c viewed from the head element 105d side, and FIG. 17B shows the actuator 105c viewed from the upper side (Z-axis direction) of the head slider. FIG. 17C is an enlarged view of the operating portions 218 and 318 in FIG. Between the first column 202 and the bridge portion 201, eight d15 mode first operation portions 218 are arranged, and between the second column 203 and the bridge portion 201, eight d15 mode second operation portions 318 are arranged.

  The height of the actuator (H1 in FIG. 17B) is 6 μm, the height of the bridge 201 (H3 in FIG. 17B), the height of the first pillar 202, and the height of the second pillar 203 (FIG. H4) in 17 (b) was 5 μm. The height of the gap 204 (H5 in FIG. 17B), and the gap 205 and the gap 305 (H6 in FIG. 17B) were set to 1 μm. The heights (H7 in FIG. 17B) of the operating portions 218 and 318 were each 4 μm.

  The length of the actuator (length X1 in the X direction in FIG. 17B) is 700 μm, the length of the bridge portion 201 (length X3 in FIG. 17B) is 420 μm, the first pillar 202 and the second pillar. The length (length X4 in FIG. 17B) was 120 μm, and the lengths of the first operating portion 218 and the second operating portion 318 (length X7 in FIG. 17B) were 20 μm.

  The length of the actuator in the Z direction (length W1 in FIG. 17A) was 230 μm. In each operating portion 218 and 318, the length of the piezoelectric body 206 in the Z-axis direction (length W206 in FIG. 17C) is 2 μm, and the length of the electrodes 209 and 210 in the Z-axis direction (in FIG. 17C). The lengths W209 and W210) were each 4 μm.

  Each actuating part was configured using the lanthanum zirconate titanate lead PZT (Zr / Ti = 52/48) as the piezoelectric body 206 and the electrodes 209 and 210 using copper. The bridge portion 201, the first pillar 202, and the second pillar 203 are the PZT (Zr / Ti = 52/48). It is assumed that gaps 211 and 311 exist between the operating parts 218 and 318. The lengths of the gaps 211 and 311 in the Z direction were all 20 μm.

  Further, a slider substrate 105a (not shown) made of 230 μm (Z direction) × 700 μm (X direction) × 850 μm (Y direction) Altic as a substrate for supporting the head slider, and 230 μm (Z direction) × 700 μm A head element 105b having a size of (X direction) × 35 μm (Y direction) was arranged. The voltage applied to the piezoelectric body 206 was 5V. The portion of the suspension 106 restrained by the head gimbal 106 is the upper surface of the slider substrate 105a (not shown) (the surface opposite to the air bearing surface).

  As a result, the head element portion showed a uniform protrusion, and the displacement amount of the head element portion in the −Z direction was 48.1 nm. In the current magnetic disk device, the flying height is 10 nm or less, which suggests that a sufficiently low voltage drive is possible.

(4th simulation)
The displacement amount was simulated for the head slider having the same structure as that of the third simulation except that the gaps 211 and 311 were filled with alumina.

  As a result, the head element portion showed a uniform protrusion, and the displacement amount of the head element portion in the −Z direction was 11.8 nm. In the current magnetic disk device, the flying height is 10 nm or less, which suggests that a sufficiently low voltage drive is possible.

  FIG. 18 is a cross-sectional view showing an example of a wiring pattern for supplying a potential to an electrode that constitutes the operating part of the head slider according to the second embodiment. In each operating portion 218, the electrode on the air bearing surface side is electrically connected to the wiring 215, and the electrode on the opposite side of the air bearing surface is electrically connected to the wiring 216. In each operating portion 318, the electrode on the air bearing surface side is electrically connected to the wiring 315, and the electrode on the opposite side of the air bearing surface is electrically connected to the wiring 316. The wiring 216 and the wiring 316 are electrically connected, but may be independent wirings. When a ground potential is applied to the wirings 215 and 315 and a bias potential is applied to the wirings 216 and 316, the electric fields E1 and E2 in the directions shown in FIG. 16 can be applied to the piezoelectric body.

  When the actuator of the second embodiment is configured to include an operating portion that generates a d15 mode displacement, the piezoelectric body constituting the operating portion is previously provided in a direction perpendicular to the air bearing surface and the surface of the slider substrate on which the actuator is provided. Create polarization. One electrode for generating polarization for displacement in the d15 mode is provided between the first column 202 and the piezoelectric body 206 with respect to the operating portion 218, and the other electrode is sandwiched between the piezoelectric body 206 and the other electrode. Provided on the opposite side. Examples of the material constituting the polarization electrode provided in the second embodiment include metals such as nickel (Ni), platinum (Pt), iridium (Ir), chromium (Cr), and copper (Cu). Furthermore, a nitride such as titanium nitride (TiN), a carbide such as tungsten carbide (WC), or an oxide such as indium tin oxide (ITO) can be used. An example of the location where the electrode for polarization is arranged will be described in the method for manufacturing the head slider according to the second embodiment described later.

  The head slider according to the second embodiment includes a bridge portion in which both ends are attached to a set of pillars on a slider substrate via a piezoelectric actuator, and a recording head provided on the bridge portion. In the head slider having such a structure, a gap is generated between the bridge portion provided with the head portion and the slider substrate, and the restraining force of the head portion on the slider substrate is reduced. Therefore, even if the voltage applied to the piezoelectric body of the operating part (piezoelectric element) constituting the actuator is low, a large amount of displacement can be obtained.

-Manufacturing Method of Head Slider of Second Embodiment-
19 to 21 are cross-sectional views illustrating the method of manufacturing the head slider according to the second embodiment. FIG. 20 is a cross-sectional view taken along the line BB ′ in FIG.

As an example of the slider substrate 105a, the sacrificial layer 51 is formed on the AlTiC substrate with a thickness of 1 μm by sputtering. The material used for the sacrificial layer 51 is a material that can be removed by an etching solution that cannot remove the slider substrate 105a, the piezoelectric body 206, and the electrodes 209 and 210. Examples of the material constituting the sacrificial layer include SiO ₂ : silica. Next, a resist is applied onto the sacrificial layer 51, and as an example, patterning is performed using an i-line stepper, dry etching using ICP is performed, and the sacrificial layer is patterned (FIG. 19A). Next, an insulating layer 52 made of alumina, for example, is formed on the sacrificial layer 51 to a thickness of 2 μm. Thereafter, the Al ₂ O ₃ : insulating layer 52 is planarized by CMP. The insulating layer 52 provided on the sacrificial layer 51 is deformed together with the actuator 105c of the completed head slider. Therefore, the thickness of the insulating layer 52 provided on the sacrificial layer 51 is preferably such that the actuator 105c can be deformed, for example, 0.4 μm or less. On the other hand, the thickness of the insulating layer 52 provided on the sacrificial layer 51 is preferably, for example, 0.2 μm or more from the viewpoint of imparting strength to the actuator 105c, but the sacrificial layer 51 is exposed. It may be good. After the insulating layer 52 is planarized, as an example, the ground-side wiring 53 is formed of Pt by a damancin process (FIG. 19B). Here, the damascene process refers to a technique for embedding wiring by exposure, etching, plating, and CMP. Next, PZT to be a piezoelectric body 206 which becomes an active part of the actuator is formed (FIGS. 19C and 20A). The thickness of the piezoelectric body 206 is 5 μm, for example, and can be formed using a sputtering method. Polarizing electrode patterns 54a to 54d made of Cu, for example, embedded by a damascene process are formed on the piezoelectric body 206 (FIG. 19D). In order to polarize in the directions of arrows P1 and P2 shown in FIG. 19 (e), potentials are respectively applied to the polarization electrodes 54a to 54d. The distance between the polarization electrodes 54a and 54b and the distance between 54c and 54d are, for example, 20 μm, and the width between 54b and 54c is, for example, 420 μm. Further, the distance from the polarizing electrode 54a to the end portion in the −X direction and the distance from the polarizing electrode 54d to the end portion in the X direction are both 120 μm, for example. For example, a DC voltage of 300 V is applied to the piezoelectric body 206 between the polarization electrodes 54a and 54b and between the polarization electrodes 54a and 54d.

After the polarization treatment, for example, the piezoelectric body 206 serving as an active portion is dry-etched by inductively coupled plasma (ICP) to form a groove 207 between the piezoelectric bodies 206 (FIG. 20B). Copper (Cu) to be the electrodes 209 and 210 is embedded in the formed groove 207 by a damascene process (FIGS. 20C and 20D). The embedded copper is dry-etched by ICP, for example, to form electrodes 209 and 210 (FIG. 20E). Next, in order to form the gap 211 between the operating parts, SiO ₂ : silica is formed as a sacrificial layer 212 by sputtering (FIG. 20F), and further flattened (FIG. 20G, FIG. 21). (A)).

  For example, in the case of filling the gap 211 between the operating parts with alumina, planarization is performed after forming the alumina by sputtering instead of silica.

  Next, a metal material such as copper (Cu) is formed on the upper surface, and further copper is patterned by lift-off of an i-line resist or the like, and the wiring 215 electrically connected to the electrodes 209 and 210 constituting each operation unit. 216, 315, and 316 are formed (FIG. 21B).

  Thereafter, for example, a layer made of silica is formed by sputtering, a resist is applied on the silica layer, patterning is performed using an i-line stepper, dry etching by ICP is performed, and the sacrificial layer 56 is patterned (FIG. 5). 21 (c)). Next, after the alumina layer 57 is formed, a via 58 for connection to the upper head element is formed by a damascene process (FIG. 21D).

  After the actuator layer is formed, a head portion 105b including a head element having normal read and write elements is formed (FIG. 21E). Here, a terminal (not shown) electrically connected to the via 58 for applying a voltage to the actuator is formed on the upper surface of the head portion 105. This terminal is electrically connected in advance by using a wiring provided on the gimbal side of the suspension and a gold pad or the like, and is electrically controlled through each arithmetic element mounted on the HDD, a driver and a controller.

  Next, the sacrificial layer is removed (FIG. 21F). The head element (not shown) is generally covered with alumina, but the read and write elements that communicate with the magnetic disk are exposed. An important part that appears on the air bearing surface of the head element such as the read and write elements is made of a magnetic alloy material and corroded by the etchant of the sacrificial layer, so that it is protected with a patterned resist. Thereafter, it is immersed in an etchant made of buffered hydrofluoric acid to selectively remove silica as a sacrificial layer formed during film formation, and voids 204, 205, 305 are formed, and a head slider having the structure of the present invention is obtained. It is done. In FIG. 21 (f), a region F1 surrounded by a dotted line corresponds to the first pillar 202 in FIG. 15, the region F2 corresponds to the second pillar 203 in FIG. 15, and the region F3 corresponds to the first operating part in FIG. The region F4 corresponds to the second actuating portion 318 in FIG. 15, and the region F5 corresponds to the bridge portion 201.

  The structure described above and the manufacturing process for realizing the structure are merely examples, and an arbitrary structure and method, process replacement, and another means can be taken.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

6, 6a to 6d Piezoelectric body 6z Insulating layer 9, 9a to 9d First electrode 10, 10a to 10d Second electrode 11, 11a to 11e Resin 13a, 13b Piezoelectric element 14 Electrode pad 15, 16 Electrode line 17 Electrode pad 18, 18a-18d Actuator (piezoelectric element)
19, 20, 29, 30 Electrode 21a to 21c Connection part 33 (Lower) electrode 34 Insulating layer 35 Insulating layer 37 Insulating part 43 Upper electrode substrate 44, 47 External terminal 48 Substrate 49 Groove 51 Sacrificial layer 52 Insulating layer 53 On the ground side Wiring 54a to 54d Polarizing electrode 56 Sacrificial layer 57 Alumina layer 58 Via 101 Hard disk drive 102 Housing 103 Rotating shaft 104 Magnetic disk 105 Slider 105a Slider substrate 105b Head portion 105c Actuator 105d Head element 105f, 105ff Floating surface 106 Suspension 106g Gimbal 107 Arm Axis 108 Carriage arm 109 Electromagnetic actuator 110 Controller 111a to 111h Wiring 112 CPU
114 RAM
115 ROM
117 bus 118 operational amplifier 119 input / output circuit 120 magnetic head support 122 base plate 123 acceleration sensor 201 bridge 202 first pillar 203 second pillar 204, 205, 305 gap 206 piezoelectric body 207 groove 209, 210 electrode 211, 311 gap 215, 216, 315, 316 wiring 218, 218a-218f 1st operation part 318, 318a-318f 2nd operation part

Claims (3)

A slider substrate having an end surface intersecting the air bearing surface;
A first column and a second column fixed on the end surface, spaced apart from each other in an in-plane direction of the air bearing surface;
A first actuating portion having a fixed end fixed to the first pillar and driving the movable end in the vertical direction of the air bearing surface;
A second actuating portion having a fixed end fixed to the second column and driving the movable end in the vertical direction of the air bearing surface;
A bridge portion fixed to the movable ends of the first and second actuating parts and suspended between the first and second actuating parts;
A magnetic head provided on the bridge portion;
A head slider characterized by comprising: The first operating portion includes a plate-like first piezoelectric body having one end fixed to the first pillar and the bridge portion fixed to the other end, the main surface facing a plane including the air bearing surface. ,
The second operating portion includes a plate-like second piezoelectric body having one end fixed to the second column and the bridge portion fixed to the other end, and a main surface facing a plane including the air bearing surface. ,
The first and second actuating parts are further provided with a first electrode (209) provided on the main surface on the air bearing surface side of the first and second piezoelectric bodies and a second electrode provided on the other main surface. (210)
When an electric field is applied between the first electrode (209) and the second electrode (210), the first and second piezoelectric bodies cause a displacement in a d15 mode or a displacement in a d31 mode, and the bridge portion is Drive,
A head slider characterized by that.   3. The head slider according to claim 1, wherein a plurality of the first and second actuating portions are respectively arranged in a vertical direction of the air bearing surface.