JP2006114209A - Head gimbal assembly having float amount adjusting function, hard disk drive using same, and method and system for adjusting float amount - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head gimbal assembly having a satisfactory float amount adjusting function. <P>SOLUTION: The head gimbal assembly comprises a magnetic head slider, a suspension for supporting the magnetic head slider, a float amount controller for controlling a float amount of the magnetic head slider, and a flexible cable electrically connected to the magnetic head slider and the float amount controller. The float amount controller comprises at least one piezoelectric member arranged between the magnetic head slider and the suspension. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a head gimbal assembly and a hard disk drive having a good flying height adjustment function, and to a flying height adjustment method and system.

  An information storage device such as a disk drive usually includes one or a plurality of magnetic disks that are rotated at a constant rotational speed by a spindle motor. In order to record / reproduce data from / to the magnetic disk, one or more information storage heads (generally referred to as “magnetic head sliders”) that float on the disk are included. This magnetic head slider has an air bearing surface called ABS, and this ABS surface faces the magnetic disk. When the magnetic disk rotates, the air pressure between the magnetic disk and the ABS surface increases, and a flying force that causes the magnetic head slider to float on the magnetic disk surface is generated hydrodynamically.

  Here, conventionally, the magnetic head slider is mounted on a suspension supported by each drive arm. The suspension equipped with the magnetic head slider is generally called “head gimbal assembly” and is abbreviated as “HGA”. The drive arm is moved and controlled by a voice coil motor (VCM).

  However, the flying height (flying height) of the magnetic head slider can be easily changed by (1) high rotation speed of the magnetic disk, (2) dimensional error of the ABS surface, and (3) suspension suspension posture. The change in the flying height greatly affects the performance of the disk drive. In other words, if the flying height is too high, the magnetic head slider that records and reproduces data on the magnetic disk will be affected. If the flying height is too low, the magnetic disk will be damaged by the impact of the magnetic head slider. The magnetic disk and the magnetic head slider can be damaged. On the other hand, in recent disk drives, the storage capacity is rapidly increasing, and the track interval and the track width of the disk drive are narrower. Therefore, since the flying height of the magnetic head slider is lower, dynamic flying height adjustment of the magnetic head slider is more important.

  In order to achieve the above-described requirements, Patent Document 1 discloses an apparatus for controlling the dynamic flying height of a magnetic head slider. Referring to FIG. 21, the disk device includes a magnetic disk 100 rotated at high speed by a spindle motor 110 and a head gimbal assembly 120 to which a magnetic head slider that floats on the magnetic disk 100 is mounted. A flying height controller 130 for controlling the dynamic flying height is mounted on the head gimbal assembly 120. FIG. 22 is an enlarged view of the flying height controller 130 portion. The flying height controller 130 includes a base portion 131 and a movable portion 132 that is movable by aerodynamic force. The movable portion 132 is configured to rotate at an edge 135 between the base portion 131 and the movable portion 132. Further, the movable portion 132 can move from a closed state substantially parallel to the base portion 131 to an open state perpendicular to the base portion 131. In the closed state, the flying height controller 130 does not affect the flying height control. However, in the open state, the flying height controller 130 pushes down the head gimbal assembly 120, and thereby the magnetic head slider. It works to reduce the flying height.

US Pat. No. 5,611,707

  However, since the flying height controller 130 only decreases the flying height and cannot increase it, the flying height adjustment performance has a limit. That is, in practice, it is necessary to increase the flying height in order to correct variations in assembling the magnetic head slider and the head gimbal assembly. In addition, since the flying height controller 130 is mounted on the head gimbal assembly 130, the weight of the head gimbal assembly increases, and the performance of the head gimbal assembly 120 such as its frequency characteristics and impact resistance can be greatly affected. There was also a problem. Further, since the flying height controller 130 is separated from the magnetic head slider, there is a problem that the adjustment accuracy is low. Furthermore, since the flying height controller 130 has a complicated structure, there arises a problem that a great amount of time is spent for manufacturing and the cost increases.

  For this reason, a flying height adjustment method and system, head gimbal assembly, and disk drive that have improved the disadvantages of the conventional example are desired.

  Accordingly, the present invention improves the disadvantages of the above-described conventional example, and in particular, a head gimbal assembly, a disk drive, and a head gimbal assembly and a disk using the flying height adjustment method having good flying height adjustment performance. Its purpose is to provide a drive. Another object of the present invention is to provide a system that dynamically adjusts the flying height.

  In order to achieve the above object, a head gimbal assembly according to an embodiment of the present invention includes a magnetic head slider, a suspension that supports the magnetic head slider, and a flying height controller that controls the flying height of the magnetic head slider. And a flexible cable electrically connected to the magnetic head slider and the flying height controller. The flying height controller includes at least one piezoelectric member disposed between the magnetic head slider and the suspension. The head gimbal assembly further includes an anisotropic conductive film (ACF) that connects the suspension and the flexible cable to the flying height controller.

  In the present invention, the at least one piezoelectric member is formed of a thin film piezoelectric member, a ceramic piezoelectric member, or a piezoelectric single crystal member (PMN-Pt piezoelectric member), and in particular, the at least one piezoelectric member is Single layer structure or multilayer structure. Further, at least one piezoelectric member is bonded to one surface or both surfaces of the suspension tongue portion forming portion of the suspension. Further, the present invention is characterized in that at least one groove portion is formed at a suspension tongue portion forming portion of the suspension.

  Further, the method for controlling the flying height using the head gimbal assembly includes (1) a step of rotating a disk for storing information, (2) a step of accessing information by a magnetic head slider; Moving the flying height controller for controlling the height of the magnetic head slider relative to the disk when the disk is rotating.

  The disk drive of the present invention includes a disk for storing information and a head gimbal assembly. The head gimbal assembly is electrically connected to the magnetic head slider, a suspension that supports the magnetic head slider, a flying height controller that controls the flying height of the magnetic head slider, and the magnetic head slider and the flying height controller. And a flexible cable.

  Furthermore, the flying height adjustment system of the present invention includes a servo control system that detects a position error signal and divides the position error signal into two signal paths, and a VCM that drives a voice coil motor to adjust the position of the magnetic head slider. VCM controller that receives one of the position error signals to control the coil motor driver, and calculates the required flying height adjustment value by receiving the other of the position error signals and comparing it with the request signal of the servo control system And a flying height adjustment counter that outputs the driving voltage at that time, and a PZT driving driver that receives the driving voltage and supplies the driving voltage to the flying height controller so as to change the flying height of the magnetic head slider. It is a feature.

  Comparing the present invention with the prior art, first, since the present invention does not require a structurally complex flying height controller in the head gimbal assembly, the weight of the head gimbal assembly corresponding to the flying height controller as in the conventional example can be reduced. There is no need to do this, and there is no need to consider impact resistance. In addition, other performance such as resonance characteristics of the head gimbal assembly is not affected. In addition, since the flying height controller of the present invention is a PZT member disposed below the magnetic head slider, the flying height of the magnetic head slider can be adjusted more accurately. Furthermore, in the present invention, the flying height of the magnetic head slider can be adjusted as necessary. In addition, the present invention can easily adjust the flying height as compared with the prior art, and can also reduce the manufacturing cost.

  In order that the present invention can be easily understood, embodiments of the present invention will be described below with reference to the accompanying drawings.

  A first embodiment of the present invention will be described. A head gimbal assembly 2 (HGA) according to the first embodiment includes a magnetic head slider 240, a flying height controller, and a suspension 100, as shown in FIG. This configuration will be further described in detail.

  1 and 2, the magnetic head slider 240 includes a plurality of electrical connection pads 241 on one end surface thereof. The flying height controller is formed of a piezoelectric member 30 (PZT) having two electrical connection pads 301 at both ends. The suspension 100 includes a load beam 219, a flexure 217, a hinge 215, and a base plate 213. The flexure 217 is connected to the hinge 215, and the load beam 219 and the base plate 213 are joined by laser welding.

  In the present embodiment, the load beam 219 includes one dimple 329 and one limiter 511 on the load beam as shown in FIG. In addition, two holes 201 and 203 are formed in the hinge 215 and the base plate 213, respectively. Here, a hole denoted by reference numeral 201 is used for swinging the head gimbal assembly 2 and a drive arm (not shown), and a hole denoted by reference numeral 203 is formed to reduce the load on the suspension.

  1 and 2, a plurality of connection pads 251 to which a control system (not shown) is connected are formed at one end of the flexure 217. A plurality of electrical connection pads 351 and 361 are formed at the other end of the flexure 217. The connection pad 251 formed on the flexure 217 is connected to the electrical connection pads 351 and 361 on the other end side by the plurality of electrical multi-trace wirings 210.

  In this embodiment, the flexure 217 is formed with a suspension tongue 328 used to support the magnetic head slider 240, and the dimple 329 (see FIG. 4) provided on the load beam 219 is provided. Thus, a load is constantly applied to the central portion of the magnetic head slider 240. Further, the suspension tongue 328 has two electrical connection pads 351 arranged at positions corresponding to the electrical connection pads 301 on the PZT member 30. Furthermore, a plurality of electrical connection pads 361 corresponding to the electrical connection pads 241 of the magnetic head slider 240 are formed on the suspension tongue 328.

  Referring to FIGS. 5 and 6, the PZT member 30 in the present invention is a single layer PZT member 380 or a multilayer PZT member 382. The single-layer PZT member 380 includes a PZT layer 373, two electrode layers 372, and two substrate layers 371. Here, the PZT layer 373 is sandwiched between two electrode layers 372, and the two substrate layers 371 are used to support and protect the PZT layer 373 and the electrode layer 372.

  In the present invention, the single layer PZT member 380 is, for example, a thin film PZT member, a ceramic PZT member, or a PMN-Pt piezoelectric member (piezoelectric single crystal member). The thickness of the PZT layer 373 is about 1 to 3 μm, and the thickness of the electrode layer 372 is thinner than 1 μm. The thickness of the substrate layer is between 0.1 μm and several microns. Therefore, the entire thickness of the single layer PZT member 380 is very thin.

  In the present invention, the multilayer PZT member 382 is formed by combining two or more single-layer PZT members 380 (single-layer PZT members without the substrate layer 371), and a plurality of single-layer PZT members 382 are combined. The PZT member 380 is combined with two substrate layers 371 so as to surround the PZT member 380. The two single-layer PZT members 380 in the multilayer PZT member 382 are coupled to each other by epoxy or resin 383. According to the above configuration, not only the “sledge” of the magnetic head slider (the warp (curve) in the width direction, which is known as the “sledge” of the magnetic head slider) is changed, but also the flying height is increased together with the “sledge” of the magnetic head slider. The bending performance of the PZT member 30 for adjusting more easily can be improved. The thickness of the epoxy or resin 383 for adhering the single-layer PZT member 380 is desirably 5 μm or less, which is a good adjustment function even though the PZT member 30 is in a very thin state. It is the thickness it has.

  Referring to FIG. 2, the suspension tongue 328 is formed with two grooves 218 in order to reduce the rigidity of the suspension tongue 328. According to this configuration, when the PZT member 30 is bent, the suspension tongue 328 is easily bent, so that a favorable flying height adjustment can be realized as described later. The suspension tongue 328 has an opening 512 corresponding to a limiter 511 provided on the load beam 219. The limiter 511 is arranged to extend through the opening 512 in order to suppress excessive movement of the suspension tongue 328.

  Referring to FIG. 2, at the time of assembly, first, the PZT member 30 is bonded to the suspension tongue 328 by the ACF member 70 (anisotropic conductive film). Accordingly, in order to establish an electrical connection between the PZT member 30 and the suspension tongue 328, the two electrical connection pads 351 on the suspension tongue 328 are connected to the electrical connection pads 301 on the PZT member 30. Electrically connected. Thereafter, the magnetic head slider 240 is disposed on the suspension tongue 328 and alignment is performed, whereby the PZT member 30 is sandwiched between the magnetic head slider 240 and the suspension tongue 328.

  In the present invention, the magnetic head slider 240 is partially bonded to the suspension tongue 328 with epoxy or adhesive 257 (see FIG. 4). In addition, the electrical connection pads 361 of the suspension tongue 328 and the electrical connection pads 241 of the magnetic head slider 240 are joined by a plurality of metal balls 501 (gold ball joint or solder bump joint (GBB, SBB)). Thus, the magnetic head slider 240 is electrically connected to the suspension tongue 328. Thus, the head gimbal assembly 2 is formed as shown in FIGS.

  Next, the operation principle of the PZT member 30 will be described with reference to FIGS. 7 (a) to 7 (c). First, when no voltage is applied to the PZT member 30, the PZT member 30 remains stationary and remains at the initial position, and the magnetic head slider 240 remains in the initial shape as shown in FIG. Then, as shown in FIGS. 8A and 8C, when a positive DC voltage 411 is applied to the PZT member 30 having a positive polarity, the PZT member 30 is bent by the piezoelectric effect. At this time, the suspension tongue portion 328 has low rigidity, and the PZT member 30 to which a positive voltage is applied is sandwiched between the magnetic head slider 240 and the suspension tongue portion 328. Is bent in the positive direction, the outer shape (mainly warpage) of the magnetic head slider 240 is also warped in the positive direction as shown in FIG. 7B.

  On the other hand, as shown in FIG. 8D, when a negative DC voltage 411a is supplied to the PZT member 30 having a positive polarity, the outer shape (mainly warpage) of the magnetic head slider 240 is as shown in FIG. As shown to (c), it follows the negative curve of the PZT member 30 which has a positive polarity, and will be in the state along a negative direction.

  Here, referring to FIG. 8B and FIG. 8C, when a positive DC voltage 411 is supplied to the PZT member 30 having a negative polarity, the PZT 30 is bent due to the piezoelectric effect. At this time, the suspension tongue 328 has low rigidity, and the PZT member 30 having a negative polarity to which a positive voltage is applied is sandwiched between the magnetic head slider 240 and the suspension tongue 328. As the PZT member 30 is bent, the outer shape (mainly warpage) of the magnetic head slider 240 is warped in the negative direction as shown in FIG.

  On the other hand, as shown in FIG. 8D, when a negative DC voltage 411a is supplied to the PZT member 30 having a negative polarity, the outer shape (mainly warpage) of the magnetic head slider 240 is as shown in FIG. As shown in (b), according to the curvature of the PZT member 30, it will be in the state along the positive direction.

  Furthermore, another operation example will be described with reference to FIGS. In these drawings, the PZT member 30 is mounted on the back surface of the suspension tongue 328. Thus, since the PZT member 30 is mounted on the back surface of the suspension tongue 328, the magnetic head slider 240 is directly disposed on the surface opposite to the back surface of the suspension tongue 328.

  As described above, first, when no voltage is applied to the PZT member 30, the PZT member 30 remains stationary and remains at the initial position, and the magnetic head slider 240 has an initial shape as shown in FIG. Remains. Here, when a positive DC voltage is applied to the PZT member 30 having a positive polarity, the PZT member 30 is bent due to the piezoelectric effect. At this time, since the suspension tongue 328 has low rigidity and the PZT member 30 to which a positive voltage is applied is mounted on the back surface of the suspension tongue 328, the PZT member 30 bends in the positive direction. Accordingly, the outer shape (mainly warp) of the magnetic head slider 240 is also warped in the positive direction, as shown in FIG. 9B.

  On the contrary, when a negative DC voltage is supplied to the PZT member 30 having a positive polarity, the outer shape (mainly warpage) of the magnetic head slider 240 has a positive polarity as shown in FIG. In accordance with the negative curvature of the PZT member 30 having, the state is along the negative direction.

  When the PZT member 30 has a negative polarity, the operation principle is the same as described above, and the description thereof is omitted.

  As a modification of the present embodiment, two or more PZT members 30 are provided on one surface or both surfaces of the suspension tongue 328. Thereby, the performance of adjusting the outer shape (mainly warpage) of the magnetic head slider can be improved. As a result, the flying height adjustment performance of the magnetic head slider 240 can be improved.

  Here, FIG. 10 shows the relationship between the warp of the magnetic head slider 240 and the flying height in the present invention. As can be seen from this figure, as the warp of the magnetic head slider 240 increases, the flying height decreases.

  A second embodiment of the present invention will be described. In the head gimbal assembly in the present embodiment, as shown in FIG. 11, the suspension tongue 328 is divided into two members, one being a movable part 703 and the other being a fixed part 702. Further, two narrow groove-shaped cut portions 298 are formed in the fixed portion 702, and a dimple 329 (see FIG. 13) provided on the load beam 219 is positioned between the two cut portions 298. is doing.

  11 to 13, at the time of assembly, first, the PZT member 30 is bonded to the movable portion 703 of the suspension tongue 328 by the ACF member 70 (anisotropic conductive film). Thereafter, the magnetic head slider 240 is disposed on the suspension tongue 328 and alignment is performed, whereby the PZT member 30 is sandwiched between the magnetic head slider 240 and the suspension tongue 328.

  In this embodiment, the magnetic head slider 240 is partially bonded to the fixed portion 702 of the suspension tongue 328 with epoxy or adhesive 257. Similarly to the above, the electrical connection among the magnetic head slider 240, the suspension tongue 328, and the PZT member 30 is then established via the metal ball 501 and the ACF member 70.

  Next, a third embodiment of the present invention will be described. As shown in FIGS. 14 and 15, the head gimbal assembly according to the present embodiment further includes a ceramic U having two PZT members 803 on both sides on the above-described PZT member 30 having two electrical connection pads 301. A character frame 801 is provided. The magnetic head slider 240 is accommodated in the U-shaped frame 801 with the four electrical connection pads 241 exposed outside.

  Further, the PZT member 803 of the U-shaped frame 801 is formed of two thin film PZT members or a ceramic PZT member. Each of these two PZT members 803 has two electrical connection pads 802.

  The suspension tongue 328 is composed of two separation members such as a movable part 703 ′ and a fixed part 702 ′. The fixed part 702 ′ has two widths for reducing the rigidity of the suspension tongue 328. Narrow groove 218 is formed. Further, on the suspension tongue 328, a plurality of electrical connection pads 824 corresponding to the electrical connection pads 802 formed on the U-shaped frame 801 are formed on the fixing portion 702 ′, and the PZT member 30 and a plurality of electrical connection pads 351 and 361 corresponding to the electrical connection pads 301 and 241 formed on the magnetic head slider 240, respectively.

  In addition, a connection pad 251 connected to a control system (not shown) is formed on one end of the flexure 217, and a plurality of electrical multi-trace wirings 210 and 211 are formed on the other end. . The connection pad 251 is electrically connected to the magnetic head slider 240 through the electrical multi-trace wirings 210 and 211, and the PZT member 30 and the two PZT members 803 are connected to a control system (not shown).

  Here, in this embodiment, at the time of assembly, first, the PZT member 30 is physically bonded to the movable portion 703 ′ of the suspension tongue 328 by the ACF member 70 (anisotropic conductive film). The electrical connection pad 301 is connected to the electrical connection pad 351 of the movable portion 703 ′. Thereafter, the U-shaped frame 801 is partially attached to the suspension tongue 328, and two PZT members of the U-shaped frame 801 are connected with a plurality of metal balls (gold ball bonding, solder bump bonding (GBB, SBB)). In order to connect 803 to the electrical trace wiring 211, the electrical connection pad 802 and the electrical connection pad 824 on the suspension tongue 328 are connected. Further, in order to electrically connect the magnetic head slider 240 to the suspension tongue 328, the electrical connection pads 241 of the magnetic head slider 240 and the electric power on the suspension tongue 328 are connected by a plurality of metal balls (GBB, SBB). The connection pad 361 is connected.

  When a driving voltage is supplied to the PZT member 803 of the U-shaped frame 801 through the electrical trace wiring 211, the PZT member 803 expands and contracts to deform the U-shaped frame 801, thereby causing the magnetic head slider to move. In order to achieve good positioning control, the magnetic head slider 240 can be rotated along the radial direction of the magnetic disk. Further, when a drive voltage is supplied to the PZT member 30 as a flying height controller through the electrical trace wiring 210, the PZT member 30 causes a change in the outer shape (mainly warp) of the magnetic head slider 240, thereby Good adjustment of flying height can be realized.

  Next, a fourth embodiment of the present invention will be described with reference to FIGS. The head gimbal assembly in the present embodiment includes a metallic support base 860 and a PZT unit 850 instead of the ceramic U-shaped frame 801 having the two PZT members 803 described above.

  The PZT unit 850 is composed of two thin film PZT members 853 (or ceramic PZT members are acceptable), and a plurality of electrical connection pads (not shown) are formed on one surface. The support base portion 860 includes a base portion 861, a lead beam 862, and a movable plate 865 having two side beams 863 on both sides.

  In this embodiment, the width of the lead beam 862 is narrower than the width of the movable plate 865. The PZT unit 850 is physically bonded to the support base portion 860 by a conventional technique such as an adhesive.

  In addition, the suspension tongue 328 of the suspension 100 is configured to be divided into two parts, a movable part 703 ″ and a fixed part 702 ″. The fixing portion 702 ″ is formed with two narrow groove portions 218 ′ to reduce the rigidity of the suspension tongue portion 328. As shown in FIG. 18, the fixing portion 702 ″ is provided on the load beam 219. A dimple 328 is positioned between the two groove portions 218 ′ to support the fixing portion 702 ″.

  16 to 18, in the present invention, after the PZT unit 850 forming the auxiliary microactuator and the support base portion 860 are joined, the auxiliary microactuator is electrically and physically connected to the flexure 217. Of the auxiliary microactuator and the suspension tongue 328 in parallel so that the auxiliary microactuator can move smoothly. A gap 313 is formed, and then the PZT member 30 is joined to the movable portion 703 ″ of the suspension tongue 328 by the ACF 70. Thereafter, the magnetic head slider 240 is positioned on the PZT member 30 and the auxiliary actuator, and is partially and physically joined to the movable plate 865 of the support base portion 860 with an ACF or an adhesive 257 ′. At this time, the magnetic head slider 240 moves together with the auxiliary microactuator by being physically joined, and electrostatic breakdown (ESD) of the magnetic head slider 240 is suppressed by being electrically connected. it can.

  In this embodiment, four metal balls 501 (GBB or SBB) are used to electrically connect the two electric multi-trace wirings 210 to the magnetic head slider 240. Further, the PZT unit 850 on the suspension tongue 328 is connected to the electrical multi-trace 211 via the electrical connection pad by ACF or conductive adhesive. The connection pads 251 on the flexure 217 electrically connect the magnetic head slider 240, the PZT member 30, the auxiliary microactuator and a control system (not shown) through the electrical multi-trace wirings 210 and 211.

  Then, when driving power is supplied to the PZT unit 850 through the electrical trace wiring 211, the PZT member 850 expands and contracts to deform the support base portion 860, thereby magnetically realizing a good positioning control. The magnetic head slider 240 can be rotated along the radial direction of the disk. Further, when a driving voltage is supplied to the PZT member 30 through the electrical trace wiring 210, the PZT member 30 causes a change in the outer shape (mainly warpage) of the magnetic head slider 240, thereby achieving a good flying height. Adjustment can be realized.

  In the present invention, after assembling the head gimbal assembly 2 (HGA), the HGA 2 is fixed to the drive arm 587. At this time, the head gimbal assembly 2 is then housed in the housing 581 and fixedly equipped. Other main components such as a magnetic disk 583, a spindle motor 585, and a voice coil motor 914 '(VCM) are also mounted in the housing 581. Thus, a disk drive is configured as shown in FIG.

  The flying height control method using the head gimbal assembly according to the present invention includes (1) a step of rotating a disk 583 for storing information, (2) a step of accessing information by a magnetic head slider 240, And 3) driving the PZT member 30 to control the height of the magnetic head slider 240 relative to the disk 583 when the disk 583 is rotating.

  FIG. 20 shows an electric control circuit for adjusting the flying height in the disk drive according to the present invention. The magnetic head slider 240 floats on the magnetic disk 580 in order to perform data recording / reproduction with respect to the magnetic disk 583. Then, a position error signal (PES) is detected by a servo control system (not shown), and the signal is divided into two signal paths (channels) indicated by reference numerals 904 and 905. Thereafter, the signal indicated by reference numeral 904 is transmitted to the VCM controller 907 that controls the VCM driver 908. The VCM driver 908 controls to drive and adjust the VCM 909 in order to perform the position length of the magnetic head slider. Further, the signal indicated by reference numeral 905 is converted into a signal of PW50 (amplitude 50%), and then transmitted to the flying height adjustment controller 910. The flying height adjustment controller 910 calculates the required FH (flying height) adjustment amount in comparison with the required PW50 signal of a servo control system (not shown), and then the flying height of the magnetic head slider 240 is increased. A drive voltage for expanding and contracting the PZT member 30 so as to change the amount is output. Thereafter, the drive voltage is sent to the PZT drive driver 911 and finally supplied to the PZT member 30 in order to adjust the flying height.

  Here, the present invention is not limited to the above-described embodiments, and can be implemented in other forms without departing from the technical idea of the present invention. Accordingly, the examples and embodiments are to be considered in all respects only as illustrative and not restrictive, and the invention is not limited to the details described herein. Absent.

  According to the above-described head gimbal assembly and a hard disk drive equipped with the head gimbal assembly, a good head position adjustment function can be realized, and thus the industrial applicability is achieved.

It is a perspective view which shows the structure of the head gimbal assembly in Example 1 of this invention. FIG. 2 is a partially enlarged exploded view of the head gimbal assembly disclosed in FIG. 1. FIG. 2 is a partially enlarged view showing a state where the head gimbal assembly disclosed in FIG. 1 is assembled. It is sectional drawing which shows the micro actuator part of the head gimbal assembly disclosed in FIG. It is sectional drawing of the PZT element in the Example of this invention. It is sectional drawing of PZT in another Example of this invention. 7 (a)-(c) show three different operating states of the PZT in an embodiment of the present invention. FIGS. 8A to 8D are explanatory views showing a state when two different voltages are supplied to the PZT. FIGS. 9 (a)-(c) show three different operating states of the PZT in another embodiment of the present invention. It is a figure which shows the relationship between the flying height of a magnetic head slider, and sled. It is the elements on larger scale which show the structure of the head gimbal assembly in Example 2 of this invention. FIG. 12 is a partially enlarged view showing a state where the head gimbal assembly disclosed in FIG. 11 is assembled. It is sectional drawing which shows the micro actuator part of the head gimbal assembly disclosed in FIG. It is a perspective view which shows the structure of the head gimbal assembly in Example 3 of this invention. FIG. 15 is a partially enlarged exploded view showing the configuration of the head gimbal assembly disclosed in FIG. 14. It is a disassembled perspective view which shows the structure of the head gimbal assembly in Example 4 of this invention. FIG. 17 is a partially enlarged view of the head gimbal assembly disclosed in FIG. 16. FIG. 17 is a cross-sectional view showing a microactuator portion of the head gimbal assembly disclosed in FIG. 16. It is a perspective view which shows the structure of the disk drive of this invention. It is a block diagram which shows the structure of the flying height dynamic adjustment system of this invention. It is a perspective view which shows the structure of the conventional system which controls the flying height of a magnetic head slider. It is the elements on larger scale which show the structure of the flying height controller in the prior art example shown in FIG.

Explanation of symbols

2 Head Gimbal Assembly 30 Piezoelectric member (PZT)
70 Anisotropic Conductive Film (ACF)
100 Suspension 213 Base plate 215 Hinge 217 Flexure 218 Groove 219 Load beam 240 Magnetic head slider 298 Notch 328 Suspension tongue 329 Dimple 511 Limiter 581 Base plate 587 Drive arm 702 Fixed part (suspension tongue)
703 Movable part (suspension tongue part)
801 U-shaped frame 850 PZT unit 860 Support base portion 861 Base portion 862 Lead beam 863 Side beam 865 Movable plate 907 VCM controller 908 VCM driver 910 Flying height adjustment controller 911 PZT drive driver

Claims (14)

A magnetic head slider, a suspension that supports the magnetic head slider, and a flying height controller that controls the flying height of the magnetic head slider;
A flexible cable electrically connected to the magnetic head slider and the flying height controller;
Head gimbal assembly characterized by that.   The head gimbal assembly according to claim 1, wherein the flying height controller includes at least one piezoelectric member disposed between the magnetic head slider and the suspension.   The head gimbal assembly according to claim 1, further comprising an anisotropic conductive film that connects the suspension and the flexible cable to the flying height controller.   The head gimbal assembly according to claim 2, wherein the at least one piezoelectric member is formed of a thin film piezoelectric member, a ceramic piezoelectric member, or a piezoelectric single crystal member (PMN-Pt piezoelectric member). .   5. The head gimbal assembly according to claim 2, wherein the at least one piezoelectric member has a single layer structure or a multilayer structure.   6. The head gimbal assembly according to claim 2, wherein the at least one piezoelectric member is mounted on one surface or both surfaces of a suspension tongue portion forming portion of the suspension.   7. The head gimbal assembly according to claim 1, wherein at least one groove portion is formed at a suspension tongue portion forming portion of the suspension. A method for controlling the flying height using the head gimbal assembly according to claim 1,
Rotate the disk that stores information,
Access information by magnetic head slider,
Moving the flying height controller for controlling the height of the magnetic head slider relative to the disk when the disk is rotating;
A flying height control method characterized by the above.   9. The flying height control method according to claim 8, wherein the flying height controller includes at least one piezoelectric member between the magnetic head slider and the suspension.   10. The flying height control method according to claim 8, wherein the anisotropic conductive film is used for connecting the flying height controller to the suspension and the flexible cable. A disk for storing information and a head gimbal assembly;
The head gimbal assembly includes a magnetic head slider that floats on the disk, a suspension that supports the magnetic head slider, a flying height controller that controls the flying height of the magnetic head slider, the magnetic head slider, and the flying height controller. A flexible cable electrically connected to the
A disk drive characterized by that.   12. The disk drive according to claim 11, wherein the flying height controller includes at least one piezoelectric member disposed between the magnetic head slider and the suspension.   13. The disk drive according to claim 11 or 12, further comprising an anisotropic conductive film that connects the suspension and the flexible cable to the flying height controller. A servo control system that detects a position error signal and divides the position error signal into two signal paths;
A VCM controller that receives one of the position error signals to control a VCM coil motor driver that drives a voice coil motor to adjust the position of the magnetic head slider;
Receiving the other of the position error signals, calculating a required flying height adjustment value by comparing with a request signal of the servo control system, and outputting a driving voltage at that time, a flying height adjustment counter;
A PZT drive driver that receives the drive voltage and supplies the drive voltage to the flying height controller to change the flying height of the magnetic head slider;
A dynamic flying height adjustment system characterized by comprising:

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