JP5983649B2 - Head assembly - Google Patents

Description

  The present invention relates to a head assembly provided with a head rotation mechanism such as a microactuator in order to increase the recording density of a magnetic disk device used in a storage device of a computer.

  In recent years, the recording density of magnetic disks in magnetic disk devices has been increasing. The magnetic disk device is provided with a slider on which a magnetic head for recording and reproducing data with respect to the magnetic disk is mounted, and this slider is supported by a head support mechanism. The head support mechanism is mounted on the head actuator arm, and is configured so that the head actuator arm can be rotated by a voice coil motor (VCM). By this VCM, the magnetic head mounted on the slider is positioned and controlled at an arbitrary position on the magnetic disk. However, in order to record data on the magnetic disk at a higher density, it is necessary to increase the positioning of the magnetic head with respect to the magnetic disk. However, the head actuator arm is simply rotated by the VCM, and the magnetic head is moved. Even if the positioning is performed, the positioning of the magnetic head cannot be improved.

  Patent Document 1 discloses the overall configuration of a head assembly including a conventional head rotation mechanism. A thin film piezoelectric element is formed at the flexure at the tip of the head assembly, and when a voltage is applied to the thin film piezoelectric element, the thin film piezoelectric element expands and contracts, thereby rotating the slider around the fulcrum protrusion. Thus, the position of the magnetic head is finely displaced, and precise positioning control is performed on the track. At this time, the head element wiring arranged on the outer periphery of the thin film piezoelectric element is expanded and contracted together with the displacement of the thin film piezoelectric element.

JP 2011-138596 A

  A thin film piezoelectric element is formed on a wafer by sputtering, but the cost is determined by the number of elements obtained from one wafer, so how many elements can be obtained from one film formation is a big problem. Become. Therefore, a more efficient driving method is required to ensure a predetermined displacement with a smaller element.

  The present invention has been made in view of such circumstances, and provides a head assembly that enables efficient driving to obtain a desired displacement of the head element without increasing the size of the thin film piezoelectric element. Objective.

  A head assembly according to the present invention is a head assembly in which a slider having a head element is supported on a slider support plate that is formed on a flexure and is rotatable around a fulcrum protrusion provided at the tip of a load beam. A first link connected to the slider support plate, a first link connected between the second joint connected to the first fixing portion, and the slider support plate. A second link connected and disposed between the third joint, a fourth joint connected to the second fixing portion, a first drive means for driving the first link, And a second driving means for driving the two links.

  With this configuration, it is possible to reduce the driving load acting on the thin film piezoelectric element when the slider reciprocates around the fulcrum, and to amplify the head displacement.

  Further, an intersection of the first line connecting the first joint and the second joint and the second line connecting the third joint and the fourth joint extending so as to coincide with the fulcrum protrusion. You may comprise. With this configuration, the driving load acting on the thin film piezoelectric element can be further reduced.

  Further, the first and second links may be constituted by a wiring portion that transmits a signal to the head element and a reinforcing plate that partially reinforces the wiring portion. This reinforcing plate etches the stainless steel substrate constituting the flexure. Thereby, it is possible to easily provide a reinforcing plate without newly adding a machining process and to realize a stable head positioning operation.

  Also, a first separation groove provided between the first driving means and the second joint and a second separation groove provided between the second joint of the second driving means are provided. It is good also as a structure. With this configuration, the amount of deformation of the driving means can be increased.

  Further, the aspect ratio L / W of the area of the first and second driving means may be 2 or more. With this configuration, the balance between the amount of displacement and the rotational rigidity of the slider can be set to an optimum state.

  According to the present invention, a head assembly that enables efficient driving in order to obtain a desired amount of displacement of the head element by reducing the driving load acting on the thin film piezoelectric element without increasing the size of the thin film piezoelectric element. Can be provided.

1 is a schematic plan view of a magnetic disk device on which a head assembly according to a preferred embodiment of the present invention is mounted. 1 is a perspective view of a head assembly according to a preferred embodiment of the present invention. 1 is an exploded perspective view of a head assembly according to a preferred embodiment of the present invention. It is a disassembled perspective view of the flexure with which the head assembly which concerns on suitable embodiment of this invention is provided. It is a top view of the 1st drive means with which the head assembly which concerns on suitable embodiment of this invention is provided. It is AA sectional drawing in FIG. 5a. It is BB sectional drawing in FIG. 5a. It is the top view which looked at the front-end | tip principal part of the head assembly which concerns on suitable embodiment of this invention from the upper surface side. It is the top view which looked at the front-end | tip principal part of the head assembly which concerns on suitable embodiment of this invention from the lower surface side. It is CC sectional drawing in FIG. It is DD sectional drawing in FIG. It is FF sectional drawing in FIG. It is HH sectional drawing in FIG. It is GG sectional drawing in FIG. FIG. 4 is a cross-sectional view showing a cross section of a portion where a first driving unit is bonded to a flexure in a head assembly according to a preferred embodiment of the present invention. It is a model figure of the rotation mechanism of the slider in the head assembly which concerns on suitable embodiment of this invention. It is the model figure which showed the mode of the rotational motion of the slider in the head assembly which concerns on suitable embodiment of this invention. It is a model figure of the rotation mechanism of the slider of a prior art example. It is a model figure of the rotation mechanism of the slider of an Example. It is a figure which shows the relationship between the aspect ratio of the thin film piezoelectric element of an Example, and head displacement amount. It is a figure which shows the relationship between the aspect ratio of the thin film piezoelectric element of an Example, and slider rotation rigidity.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined. In addition, various omissions, substitutions, or changes of the components can be made without departing from the scope of the present invention.

  FIG. 1 schematically shows the overall configuration of a load / unload magnetic disk device (HDD device) 1 on which a head assembly according to a preferred embodiment of the present invention is mounted. As shown in FIG. 1, a magnetic disk device 1 includes a housing 4, a magnetic disk 6 that is driven to rotate about a shaft 5 by a spindle motor, a head assembly 2 in which a slider 3 having a head element 7 is mounted at the tip, It comprises a support arm 8 that supports the head assembly 2 at its tip.

  A coil portion of a voice coil motor (VCM) is attached to the rear end portion of the support arm 8, and the support arm 8 can be rotated in parallel with the surface of the magnetic disk 6 about the horizontal rotation shaft 9. ing. The VCM is composed of a coil part (not shown) and a magnet part 10 covering the coil part. A ramp mechanism 11 is provided from the outside of the data area of the magnetic disk 6 to the outside of the magnetic disk 6. It is separated from the disk 6 and is in an unloaded state.

  During the operation of the magnetic disk device 1 (during high-speed rotation of the magnetic disk), the slider 3 faces the surface of the magnetic disk 6 and floats with a low flying height and is in a loaded state. On the other hand, at the time of non-operation (while the magnetic disk is stopped or during low-speed rotation at the time of starting and stopping), the tab 12 at the tip of the head assembly 2 is on the ramp mechanism 11, so the slider 3 is in an unloaded state.

  FIG. 2 is a perspective view schematically showing the overall configuration of the head assembly 2 according to a preferred embodiment of the present invention. Hereinafter, for convenience of explanation, the Z-axis positive direction in the figure is referred to as the upper surface side of the head assembly 2, and the Z-axis negative direction is referred to as the back surface side or the lower surface side of the head assembly 2. The slider 3 includes a head element 7 composed of an inductive write head element and an MR read thin film magnetic head such as a giant magnetoresistive (GMR) read head element or a tunnel magnetoresistive (TMR) read head element. The trailing edge is provided on the Y-axis positive side in FIG.

  As shown in FIG. 2, the head assembly 2 includes a base plate 13, a load beam 14, a flexure 15, a first thin film piezoelectric element as a first driving means 16a, and a second driving means 16b as main components. A second thin film piezoelectric element and a slider 3 are provided. Further, the base plate 13 is configured to be attached to the distal end portion of the support arm 8.

  As shown in FIG. 2, the load beam 14 is fixed to the base plate 13 by a plurality of beam welding points 17a and the like. Further, a leaf spring 18 is formed on the load beam 14 so that a predetermined pressing force is generated on the slider 3. Furthermore, the load beam 14 has a structure in which bending portions 19 are provided on both sides to increase the strength. The flexure 15 is fixed to the load beam 14 by a beam welding point 17b. In FIG. 2, the pitch direction of the attitude angle of the slider 3 is indicated by Dp, the roll direction is indicated by Dr, and the yaw direction is indicated by Dy.

  FIG. 3 is an exploded perspective view schematically showing the head assembly 2 according to a preferred embodiment of the present invention. That is, the head assembly 2 is disassembled into a load beam 14, a flexure 15, a base plate 13, driving means 16a and 16b, and a slider 3.

  As shown in FIG. 3, the slider 3 is bonded and fixed on a slider support plate 20 formed on the flexure 15. A fulcrum projection 21 is integrally formed on the center line in the vicinity of the tip of the load beam 14, and the fulcrum projection 21 is supported by the first outrigger 22 a and the second outrigger 22 b. The structure which becomes the pivot structure which contacts is formed. Thus, the slider 3 is configured to smoothly follow the flying posture corresponding to the undulation of the disk surface.

  The first driving means 16a and the second driving means 16b are thin film piezoelectric elements, and are bonded on the first piezoelectric support section 23a and the second piezoelectric support section 23b. Note that the first piezoelectric support portion 23a and the second piezoelectric support portion 23b are formed only of the insulating layer forming the flexure 15.

  FIG. 4 is an exploded perspective view showing the configuration of the flexure 15 provided in the head assembly according to the preferred embodiment of the present invention. The flexure 15 is a wiring board manufactured using a material in which an insulating layer is generally coated on a thin stainless steel plate of about 20 μm and a copper foil is plated thereon, and an arbitrary shape is precisely formed by an etching process. Can be processed. In FIG. 4, the flexure substrate 24 made of stainless steel and the head element wiring 25 (wiring portion) are separated and displayed for easy understanding, although the flexure is originally an integral one.

  FIG. 5a is a plan view of the first driving means 16a provided in the head assembly according to the preferred embodiment of the present invention. Moreover, FIG. 5b represents the AA cross section in FIG. 5a, and FIG. 5c represents the BB cross section in FIG. 5a. An upper electrode 27a is formed on the upper surface side of the thin film piezoelectric body 26, and a lower electrode 27b is formed on the lower surface side. Since the first and second driving means 16a and 16b are very thin and easily damaged, a base 28 is provided as a reinforcing material.

  The entire first and second driving means 16 a and 16 b are covered with an insulating cover 30 made of polyimide in order to protect the thin film piezoelectric body 26. Note that the insulating cover 30 is partially removed from the C and D portions in FIG. 5a. In part C, the lower electrode 27b is exposed and is electrically connected to the first electrode pad 29a. In the portion D, the upper electrode 27a is exposed and is electrically connected to the second electrode pad 29b. Further, by applying a voltage to the first electrode pad 29a (third electrode pad 29c) and the second electrode pad 29b (fourth electrode pad 29d), the first driving means 16a (second driving) The thin film piezoelectric body 26 of the means 16b) can be expanded and contracted. The direction of polarization of the thin film piezoelectric body 26 is indicated by an arrow. When a negative voltage is applied to the first electrode pad 29a and a positive voltage is applied to the second electrode pad 29b, the thin film piezoelectric body 26 contracts in the in-plane direction of the piezoelectric film due to the piezoelectric constant d31.

  FIG. 6 is a plan view of the main portion of the tip of the head assembly 2 according to the preferred embodiment of the present invention as viewed from the upper surface side (slider 3 side). FIG. 7 is a plan view of the main part of the tip of the head assembly according to the preferred embodiment of the present invention as viewed from the lower surface side (plan view of the head assembly 2 of FIG. 6 as viewed from the rear surface side). The load beam 14 is excluded from the figure. The slider 3 is bonded onto the slider support plate 20, and a head element wiring 25 (wiring portion) corresponding to the head electrode terminal 31 is installed and connected by a solder ball.

  In FIG. 6, the slider support plate 20 has a first bent portion 32a and a second bent portion 32b partially formed on first and second outriggers 22a and 22b arranged on both sides. Further, the intersections in the extending direction of the left and right first and second bent portions 32 a and 32 b are configured to coincide with the fulcrum protrusion 21. Further, the slider support plate 20 is configured to rotate around the fulcrum protrusion 21 by the action of the first bent portion 32a and the second bent portion 32b provided at the intermediate position between the first and second outriggers 22a and 22b. It has become.

  The slider support plate 20 is formed with a counter balance 33 set so that the inertial axis in the yaw direction of the rotating portion including the slider 3 coincides with the fulcrum protrusion 21. The slider support plate 20 is formed with a T-type limiter 34 for lifting the slider 3 when the slider 3 is unloaded from the disk. The slider support plate 20 engages with a hole 35 formed in the load beam 14. Yes. Note that the T-type limiter 34 and the hole 35 are not in contact with each other through a gap during normal operation.

  The head element wiring 25 (wiring portion) is arranged so as to surround the slider 3, and its end is connected to the head electrode terminal 31 of the slider 3. The head element wiring 25 (wiring section) has first and second outriggers 22a and 22b fixed thereto (CC section in FIG. 6), and a first drive rib 36a extending from the slider support plate 20. The second drive rib 36b is also fixed in the same manner (FF portion in FIG. 6).

  The first and second driving means 16a and 16b are driven by applying a voltage to the first, second, third and fourth electrode pads 29a, 29b, 29c and 29d. The drive wiring 37a is arranged to input inputs to the first electrode pad 29a of the first drive means 16a and the fourth electrode pad 29d of the second drive means 16b, and the ground wiring 37b is connected to the first electrode pad 29a. The second electrode pad 29b of the driving unit 16a is connected to the third electrode pad 29c of the second driving unit 16b. Thus, when an alternating drive signal is input to the drive wiring 37a, the first drive unit 16a and the second drive unit 16b expand and contract in opposite directions.

  In the flexure 15, an insulating layer 41 such as polyimide is formed on a stainless material having a thickness of 18 μm, and a head element wiring 25 (wiring portion) is formed thereon. Further, the wiring cover layer 42 such as polyimide is used for the purpose of insulating or protecting the wiring. The flexure 15 secures necessary mechanical functions by etching the flexure substrate 24 made of stainless steel into an arbitrary shape. The flexure configuration shown in FIG. 6 (FIG. 7) is shown in several cross-sections using FIGS. 8a to 8e. FIG. 8a is a cross-sectional view taken along the line CC in FIG. 8b is a sectional view taken along the line DD in FIG. 6, FIG. 8c is a sectional view taken along the line FF in FIG. 6, FIG. 8d is a sectional view taken along the line HH in FIG. The DD cross-section and the GG cross-section have the same cross-sectional shape, and the stainless material below the head element wiring 25 (wiring portion) is removed by etching.

  FIG. 9 is a view showing a cross-section (cross-section EE in FIG. 6) of the portion where the first driving means 16a is bonded to the flexure 15 in the head assembly 2 according to the preferred embodiment of the present invention. The first driving means 16a has a first piezoelectric body support portion 23a at a position where the tip portion of the first link 39a is formed with the reinforcing plate 43a while leaving a part of the flexure substrate 24 and the front end portion overlaps the reinforcing plate 43a. It is glued on top. Similarly, the second driving means 16b supports the second piezoelectric body at a position where the tip portion overlaps the reinforcing plate 43b on the second link 39b in which the reinforcing plate 43b is formed leaving a part of the flexure substrate 24. Bonded on the portion 23b. This is because the displacement of the thin film piezoelectric body 26 is reliably transmitted to the first link 39a (second link 39b). As shown in FIG. 9, the first links 39 a and 39 b are composed of a head element wiring portion 25 that transmits a signal to the head element 7 and reinforcing plates 43 a and 43 b that partially reinforce the head element wiring portion 25. Composed.

  The first link 39a is connected and installed between the first joint 40a and the second joint 40b. The first joint 40a is connected to the first drive rib 36a, and the second joint 40b is connected to the first fixing portion 24a that is a part of the flexure 15 (FIG. 7). Similarly, the second link 39b is connected and installed between the third joint 40c and the fourth joint 40d, and the third joint 40c is connected to the second drive rib 36b and the fourth joint 40d. Is supported by a second fixing portion 24b which is a part of the flexure 15 (FIG. 7). The third and fourth joints 40c and 40d have the same structure as the first and second joints 40a and 40b. As shown in FIG. 8e, the first joint 40a is formed by a head element wiring 25 (wiring portion) obtained by removing the flexure substrate 24 of the flexure 15 by etching. Similarly, as shown in FIG. 8d, the second joint 40b is formed by the head element wiring 25 (wiring portion) obtained by removing the flexure substrate 24 of the flexure 15 by etching. Since the first and second joints 40a and 40b are more flexible than the first link 39a, when the first drive means 16a expands and contracts, the first link 39a becomes the second joint 40b. It is comprised so that a micro rotational movement may be carried out centering on. Similarly, when the second drive unit 16b expands and contracts, the second link 39b performs a fine rotation about the fourth joint 40d.

  The base plate 13 and the load beam 14 of the head assembly 2 are line symmetric with respect to the central axis parallel to the Y-axis direction in each drawing. Also, the first link 39a and the second link 39b, the first joint 40a and the second joint 40b, the third joint 40c and the fourth joint 40d, the first driving means 16a and the second driving means. Similarly, the structure such as 16b is line-symmetric with respect to the central axis parallel to the Y-axis direction in each drawing.

  6 and 7, a first separation groove 44a for separating the first driving means 16a from the second joint 40b and the flexure substrate 24 is provided, and the first separation groove 44a is a thin film piezoelectric film. It is formed along a range corresponding to the length of the body 26 in the longitudinal direction (X-axis direction). By the first separation groove 44a, the displacement of the thin film piezoelectric body 26 is released from the restraint of the second joint 40b including the head element wiring 25 (wiring portion) and the flexure substrate 24, so that the displacement can be maximized. Since the head assembly 2 has a line-symmetric shape with respect to an axis of symmetry parallel to the Y axis, the same applies to the second separation groove 44b from FIG.

  FIG. 10 is a simplified model view of the mechanism in which the slider 3 pivots around the fulcrum protrusion 21 by the first and second driving means 16a and 16b in FIG. 6, and is viewed from the back side of the head assembly 2. ing. One end of the first driving means 16 a is fixed to the first link 39 a drawn in an L shape, and the other end is fixed to the flexure substrate 24. A first joint 40a and a second joint 40b are formed at both ends of the first link 39a.

  The first joint 40a is a region sandwiched between the first drive rib 36a and the first link 39a in FIG. Similarly, the second joint 40b corresponds to a region sandwiched between the first link 39a and the flexure substrate 24 in FIG. Similarly, the third joint 40c is a region sandwiched between the second link 39b and the second drive rib 36b, and the fourth joint 40d is a region sandwiched between the second link 39b and the flexure substrate 24. It corresponds to. These first to fourth joints 40a to 40d bend relatively flexibly because the flexure substrate 24 is removed by etching.

  10, the first line segment L1 connecting the first joint 40a and the second joint 40b and the second line segment L2 connecting the third joint 40c and the fourth joint 40d are It is preferable to intersect at the fulcrum protrusion 21. This is because the first line segment L1 rotates about the joint 40b and the second line segment L2 rotates about the joint 40d, but the first line segment L1, the second line segment L2, and the slider 3 The instantaneous center in the slider rotation movement is a mechanism constituted by the fulcrum protrusion 21. That is, if the fulcrum protrusion 21 coincides with the instantaneous center, there is no load on the rotational operation, and a larger rotational displacement can be obtained.

  FIG. 11 is a model diagram in which the state in which the slider 3 is rotated about the fulcrum protrusion 21 by the first and second driving means 16a and 16b in FIG. Seen from. The operation of the turning mechanism configured as described above will be described with reference to FIG. First, a voltage is applied to the second driving means 16b, an electric field is applied in the polarization direction, and the second driving means 16b contracts. On the other hand, since the same voltage is applied to the first driving means 16a in the reverse direction with respect to the second driving means 16b, the first driving means 16a expands. The deformed shape of the drive means alone is indicated by a broken line. As a result, the first link 39a rotates clockwise about the second joint 40b, and the second link 39b rotates about the fourth joint 40d in the same direction. Here, since the fulcrum protrusion 21, the first joint 40a, and the second joint 40b are arranged on a straight line, the first joint 40a rotates around the fulcrum protrusion 21. Similarly, since the fulcrum protrusion 21, the third joint 40c, and the fourth joint 40d are in a straight line, the third joint 40c rotates around the fulcrum protrusion 21. However, the slider 3 rotates counterclockwise around the fulcrum protrusion 21.

  Hereinafter, the embodiment and the conventional example will specifically show that the head displacement amount can be amplified according to the present embodiment. FIG. 12 is a simplified model diagram of the head assembly 2 having a conventional configuration (conventional example). Calculation of the head displacement amount x is shown using FIG.

  Formula 1 is a formula for calculating the head displacement amount x1 [nm / V] of the conventional example. d31 is the piezoelectric constant, V is the applied voltage, L is the length of the piezoelectric body, E is the longitudinal elastic modulus of the piezoelectric body, W is the width of the piezoelectric body, K is the upper electrode 27a, lower electrode 27b, first and second Mechanical loads 38 and t of the bent portions 32a and 32b, each joint portion, etc., t is the thickness of the piezoelectric body, C3 is the distance between the fulcrum protrusion 21 and the head element 7, and C4 is the distance between the conventional joint 40e and the fulcrum protrusion 21. Distance. From Formula 1, for example, the displacement x1 of the head element in the conventional model when the effective displacement length L of the thin film piezoelectric element is 90 μm and the effective displacement width W is 360 μm is 9.15 nm.

  FIG. 13 is a model diagram in which the configuration of the head assembly 2 of the example based on the configuration of the embodiment is simplified. In the embodiment, thin film piezoelectric elements 16a and 16b (first and second driving means 16a and 16b) having the same size as the conventional example are used. The calculation of the head displacement x2 is shown using FIG. Formula 2 is a calculation formula of the head displacement amount x2 [nm / V] of the embodiment, and a is the X direction between the fourth joint 40d and the end of the second driving means 16b on the side away from the slider 3. C1 is the distance between the third joint 40c and the fourth joint 40d, C2 is the distance between the third joint 40c and the fulcrum protrusion 21, and C3 is the distance between the fulcrum protrusion 21 and the head element 7. C4 is the distance in the X direction between the head element 7 and the third joint 40c. When calculated using Equation 2, the displacement x2 of the head element in this example was 17.3 nm.

  Comparing the results of the conventional example and the example, the head displacement amount x1 of the conventional example x1 = 9.15 nm compared to the head displacement amount x2 = 17.3 nm of the example. Therefore, the example is displaced compared to the conventional example. It was confirmed that the amount x was improved about twice.

  FIG. 14 is a model of FIG. 13, in which the area (= L * W) of the effective displacement portion of the thin film piezoelectric element (first and second driving means 16a and 16b) is constant, and the horizontal axis indicates the thin film piezoelectric element. The result of calculating the head displacement when the ratio of the length L to the width W of the (first and second driving means 16a, 16b) and the aspect ratio L / W are changed is shown. Line 1 is the case of the reference mechanical load 38, line 2 is the case of the mechanical load 38 that is twice the reference, and line 3 is the result of the case of the mechanical load 38 that is three times the reference. Yes. Of course, the displacement decreases as the mechanical load 38 increases. Further, when the head displacement amount is increased by increasing the aspect ratio L / W, the head displacement amount x is improved, but the degree of improvement gradually decreases. When the aspect ratio L / W is increased in a certain area, the width dimension is naturally reduced and the drive load cannot be endured. Therefore, there is a limit to increasing the aspect ratio L / W. The head displacement amount x refers to the amount of movement of the head element 7 when the slider 3 is rotated about the fulcrum protrusion 21 by the thin film piezoelectric element (first and second driving means 16a, 16b). The larger the head displacement amount x, the better.

  FIG. 15 is a diagram showing the rotational rigidity of the slider 3 with the aspect ratio L / W of the thin film piezoelectric element (first and second driving means 16a, 16b) as the horizontal axis. As the aspect ratio L / W increases, the rotational rigidity of the slider 3 decreases. That is, in FIG. 14, when the aspect ratio L / W is 2 or more, the improvement degree of the displacement is dull. In FIG. 15, when the aspect ratio L / W is 2 or more, the decrease in the rotational rigidity of the slider 3 becomes moderate. It can be said that the displacement amount characteristic of FIG. 14 and the rotational rigidity characteristic of FIG. 15 are in a trade-off. Therefore, the aspect ratio L / W is an aspect ratio L / W of the thin film piezoelectric element (first and second driving means 16a, 16b) in which the head displacement is stable and the rotational rigidity of the slider 3 is as large as possible. W should be 2 or more. When the aspect ratio L / W is 5 or more, the effect of improving the head displacement amount is lost, and the rotational rigidity of the slider 3 is reduced. Therefore, the aspect ratio L / W is preferably 5 or less.

  As described above, according to the present embodiment, the desired amount of displacement of the head element can be obtained efficiently without increasing the size of the thin film piezoelectric elements (first and second driving means 16a and 16b), and the efficiency can be improved. The head assembly 2 that enables efficient driving can be realized. Further, unlike the wiring structure described in Patent Document 1, since the wiring does not surround the thin film piezoelectric element, when the thin film piezoelectric element (first and second driving means 16a and 16b) is deformed, the wiring In this configuration, the displacement of the thin film piezoelectric element is not suppressed by simply expanding and contracting, but rather the displacement is efficiently amplified by using a wiring portion to form a link configuration. As a result, a predetermined amount of displacement can be secured with a smaller thin film piezoelectric element, and the cost of the assembly can be reduced.

DESCRIPTION OF SYMBOLS 1 Magnetic disk apparatus 2 Head assembly 3 Slider 4 Housing 5 Spindle motor shaft 6 Magnetic disk 7 Head element 8 Support arm 9 Horizontal rotation shaft 10 of VCM Magnet part 11 Lamp mechanism 12 Tab 13 Base plate 14 Load beam 15 Flexure 16a 1st Drive means (thin film piezoelectric element)
16b Second driving means (thin film piezoelectric element)
17a, 17b Beam welding point 18 Leaf spring 19 Bending portion 20 Slider support plate 21 Support point projection 22a First outrigger 22b Second outrigger 23a First piezoelectric support 23b Second piezoelectric support 24 Flexure substrate 24a First fixing portion 24b Second fixing portion 25 Head element wiring 26 Thin film piezoelectric body 27a Upper electrode 27b Lower electrode 28 Base 29a First electrode pad 29b Second electrode pad 29c Third electrode pad 29d Fourth Electrode pad 30 Insulating cover 31 Head electrode terminal 32a First bent portion 32b Second bent portion 33 Counterbalance 34 T-type limiter portion 35 Load beam hole portion 36a First drive rib 36b Second drive rib 37a Drive wiring 37b Ground wiring 38 Mechanical load 39a First link 39b Second Link 40a First joint 40b Second joint 40c Third joint 40d Fourth joint 40e, 40f Conventional joint 41 Insulating layer 42 Wiring cover layers 43a, 43b Reinforcement plate 44a First separation groove 44b Second separation groove

Claims (6)

A slider having a head element is a head assembly supported on a slider support plate that is formed on a flexure and is rotatable around a fulcrum projection provided at a tip portion of a load beam,
A first link connected and disposed between the first joint connected to the slider support plate and the second joint connected to the first fixed portion;
A second link connected and disposed between a third joint connected to the slider support plate and a fourth joint connected to the second fixed portion;
First driving means for driving the first link;
Second driving means for driving the second link ;
First and second outriggers disposed on both sides of the slider support plate;
The first and second joints are formed by a wiring portion from which the flexure substrate of the flexure is removed,
The third and fourth joints are formed by a wiring portion from which the flexure substrate of the flexure is removed,
The head assembly is characterized in that the first and third joints rotate around the fulcrum protrusion .   An intersection of the first line connecting the first joint and the second joint and the second line connecting the third joint and the fourth joint is extended to the fulcrum protrusion. The head assembly according to claim 1, wherein the head assemblies coincide with each other.   3. The head according to claim 1, wherein each of the first and second links includes a wiring portion that transmits a signal to the head element and a reinforcing plate that partially reinforces the wiring portion. Assembly. A first separation groove provided between the first driving means and the second joint, and a second separation groove provided between the second driving means and the fourth joint; The head assembly according to any one of claims 1 to 3, wherein the head assembly is provided.   The head assembly according to any one of claims 1 to 4, wherein an aspect ratio L / W of an area of the first and second driving means is 2 or more. The first link is configured to pivot about the second joint;
The head assembly according to any one of claims 1 to 5, wherein the second link is configured to rotate about the fourth joint.

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