JP2008034091A - Microactuator, head gimbal assembly with microactuator, and method of manufacturing head gimbal assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve cost-effectiveness by increasing the displacement of a microactuator, while imparting excellent dynamic performance and shock resistance to an HGA (Head Gimbal Assembly). <P>SOLUTION: The microactuator 20 is configured by including a base part and a metal frame 22 that has two arms facing each other and extending from the base part. At least two thin films PZT are separately loaded on the side surface of each arm so that the displacement of each arm may be increased by the synergetic effect if each arm and the thin film PZT loaded thereon is simultaneously displaced in accordance with driving signals applied to the thin film PZT 21. Moreover, because at least two thin films PZT are loaded on the side surface of each arm, the synergetic effect is generated, thereby achieving an increase in the arm displacement. The at least the two thin films PZT can be arranged on the front side of the same side of the arm, or be separately arranged on the front side of the outer side and/or the inner side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information recording facility, and more particularly to a head gimbal assembly (HGA) microactuator used in a disk drive unit and a method of manufacturing a head gimbal assembly including the microactuator.

  At present, people are seeking to improve the recording density of information recording facilities using various methods. FIG. 1 is a diagram illustrating a conventional disk drive unit used as an information recording apparatus. Among them, the spindle motor 15 drives the rotation of the disk 14, and the drive arm 12 controls a magnetic head (not shown) disposed on the head gimbal assembly 18, which flies over the surface of the disk 14. Let me do that. Normally, a voice coil motor (VCM) 16 is used to control the operation of the drive arm 12 and coarsely adjusts the position of the drive arm 12 on the disk 14. As shown in FIG. 2a, the figure shows a head gimbal assembly (HGA) 18 having the conventional PZT (Piezoelectric Lead Zirconate Titanate) microactuator 181 shown in FIG. When the magnetic head is driven independently, there is an inherent error (dynamic vibration) in the displacement of the magnetic head, so the suspension tongue 1831 of the suspension 183 of the HGA 18 is used for fine position control with respect to the magnetic head. Installed microactuator. Usually, the microactuator 181 installed around the magnetic head is a PZT microactuator and is used to finely adjust the displacement of the magnetic head. That is, the VCM 16 is used for coarse adjustment, and the PZT microactuator compensates for the vibration of the drive arm caused by driving the VCM 16 by adjusting the displacement of the magnetic head with a smaller width. The HGA 18 having such a configuration can provide a track width that is very small and can be recorded, and therefore, the number of tracks per inch (TPI) can be increased by about 50%.

  More specifically, in the conventional HGA 18 shown in FIG. 2a, a magnetic head (not shown) is mounted on a slider 182 to form the magnetic head. The slider 182 is used to maintain a predetermined height from the surface of the disk 14 (see FIG. 1) of the magnetic head (not shown). FIG. 2 b shows a structure of a conventional microactuator 181, in which the U-shaped microactuator 181 includes a ceramic frame, which includes two ceramic arms 1811 on which a slider 182 can be placed, And two ceramic PZTs 1813 mounted on the outer surface of each ceramic arm 1811. Also, referring to FIG. 2a, the PZT microactuator 181 is physically mounted on the suspension tongue 1813 of the suspension 183 of the HGA 18, so that the slider 182 is responsive to the voltage applied to the ceramic PZT 1813. The ceramic 1813 moves independently of the suspension 183 by the action of the ceramic 1813. More specifically, there are three electronic connection balls 185 (GBB or SBB, gold balls or solder balls) on each side surface of the ceramic arm 1811, and thereby the microactuator 181 becomes a suspension trace 184. Similarly, the slider 182 is attached to the suspension trace 184 by four electronic connection balls 186 (GBB or SBB). In addition, the other end of the trace is connected to the suspension pad 187 so as to provide power through the suspension trace 184. The expansion and contraction of the PZT causes deformation of the ceramic arm 1811 of the U-shaped microactuator 181, but this causes the slider 182 to move on the disk, and accordingly, with respect to the magnetic head mounted on the slider 182. Precise position adjustment.

  Since the conventional HGA employs a U-shaped ceramic microactuator and the PZT element is also formed from a ceramic material, the larger mass of the ceramic material can affect the dynamic performance of the HGA. In addition, since the ceramic material is a fragile material, the impact resistance of the ceramic microactuator is limited, and undesired granules are generated in the course of work.

  In order to reduce the weight of the microactuator and improve the dynamic performance of the HGA, U.S. Pat. More specifically, the frame is made of stainless steel. By utilizing a metal frame, the dynamic performance of the microactuator can be significantly improved.

  On the other hand, in recent years, a method for solving the problems of low impact resistance and granule formation using a kind of thin film PZT has been submitted. However, since the number of layers of the thin film PZT is limited, sufficient displacement cannot be generated. Displacement of the thin film PZT can be increased by forming the thin film PZT in a plurality of layers. However, since the thin film PZT manufacturing technology is localized, if the number of layers of the thin film PZT exceeds two layers, the cost increases. Extremely high.

  In view of the above problems, it is necessary to increase the displacement of the thin film PZT of the microactuator by adopting a cost-effective method.

US Pat. No. 6,950,288

  The present invention provides an HGA microactuator for use in a disk drive unit, which can provide good dynamic performance and impact resistance to the HGA, and can increase the displacement of the microactuator to achieve cost effectiveness. The main purpose.

  In order to achieve the above object, a microactuator according to the present invention includes a metal frame having a base portion and two relative arms extending from the base portion, where a drive signal applied to the thin film PZT is applied. Accordingly, when each arm and the thin film PZT mounted thereon are displaced together, at least two sheets are separately provided on the side surface of each arm so that the displacement of each arm is increased by the polymerization effect. Wear thin film PZT.

  Specifically, the present invention provides a microactuator formed by attaching a thin film PZT to the side surface of each arm of a metal frame to reduce the total mass of the HGA, and Improve dynamic performance. By mounting at least two thin film PZTs on one side, the side surface of each arm of the metal frame, a displacement effect of the magnetic head is generated so that a polymerization effect is generated in the displacement of the arm, that is, the displacement of the magnetic head. Achieve the purpose of increase.

  In addition, compared with ceramic PZT, thin film PZT has an extremely small mass, so that it has a great effect on HGA performance and manufacturing technology. For example, if the mass is reduced, the impact resistance is further improved. On the other hand, in the process of manufacturing the thin film PZT, fine control over the size of the thin film PZT can be realized, and manufacturing errors can be reduced.

  Furthermore, in the present invention, since the thin film PZT can be operated at a lower voltage, granule formation and consumption during operation are further reduced, and high impact resistance and extremely safe operating conditions can be obtained.

  Here, it is preferable that the two thin films are attached to the outer and inner surfaces of the arms. With such a double-sided mounting structure, even if the number of equivalent working layers of the thin film PZT mounted on each arm is doubled, the actual number of layers of each thin film PZT does not increase, so the displacement of the macro actuator can be greatly increased. . This increases the displacement of the microactuator and provides good cost effectiveness.

  The two thin film PZTs mounted on the outer and inner surfaces of each arm are preferably connected together mechanically and electrically via a substrate, which attaches the thin film PZT to the side surface of the arm. It is also effective for localization.

  Further, by bending a shared substrate of the at least two thin film PZTs so that it straddles the front end or the rear end of the arm, the at least two thin film PZTs are connected through the substrate, These at least two thin film PZTs are preferably arranged on both sides of the arm.

  Further, by bending a shared substrate of the at least two thin film PZTs so that it straddles the upper edge of the arm, the at least two thin film PZTs are connected via the substrate, and at least these Two thin film PZTs are preferably arranged on both sides of the arm.

  Preferably, the substrate is formed of a flexible polymer material, and an electric trace used for electrically connecting the at least two thin film PZTs is formed thereon.

  Of course, the two thin film PZTs can be attached to each arm of the metal frame by other methods. More specifically, the two thin film PZTs can be mounted on the same surface of each arm. That is, the two thin film PZTs can be mounted on the outer or inner surface of each arm in series. Even in this case, the polymerization effect can be obtained. However, in order to achieve the maximum displacement, the length of each thin film PZT needs to be about 1 mm.

  A support part for supporting the slider is formed at the other end of each arm facing the base part, and the support part is arranged on a parallel plane different from the base part, so that the bottom part of the support part and the base It is preferable to form a gap between the bottom of the part.

  The present invention provides a head gimbal assembly including the microactuator as described above, a slider, and a suspension. The slider includes at least one magnetic sensor, is housed in a metal frame and is driven by the microactuator, and the suspension is fixed to a base portion of the metal frame on the suspension tongue. An actuator is provided on the suspension to allow independent movement of the two arms and slider relative to the suspension.

  The present invention includes a disk, a pivot center (the disk rotates around the pivot center), a VCM for driving a magnetic head to move on the disk surface, and a magnetic force coupled to the VCM. There is provided a disk unit for recording information including a head gimbal assembly for adjusting displacement of the head. Among them, the head gimbal assembly includes a microactuator as described above.

  And, the present invention includes a step of attaching two thin film PZTs to the outer and inner surfaces of each arm to form a microactuator, a step of attaching a slider having a magnetic sensor to the microactuator, By fixing the base portion of the metal frame to the suspension tongue of the suspension, the step of mounting the microactuator on the suspension, the microactuator and the suspension, and the slider including the magnetic sensor and the suspension are electrically connected. A method of manufacturing a head gimbal assembly.

  Here, the step of attaching the thin film PZT to the outer and inner surfaces of the arms respectively includes two thin film PZTs that are mechanically and electrically connected through a substrate. Providing a thin film PZT; bending each thin film PZT at the center of the substrate so that the two thin films PZT constituting each thin film PZT are substantially parallel to each other; and each arm Are sandwiched between two thin film PZTs after bending, and the two thin film PZTs after bending are separately applied to the outer and inner surfaces of each arm so that the substrate straddles the arm. Preferably, further comprising the step of mounting.

  Therefore, another method for manufacturing a head gimbal assembly is to mount two thin film PZTs on the same side surface of each arm in a series manner, and a slider with a magnetic sensor in the microactuator. A mounting step; a step of mounting the microactuator to the suspension by fixing a base portion of the metal frame to a suspension tongue of the suspension; a slider including the microactuator and the suspension; and the magnetic sensor. Electrically joining the suspension.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the attached drawings, the same or similar parts are denoted by the same or similar reference numerals.

  3a to 3c are diagrams illustrating in detail the structure of the microactuator and its components according to the first embodiment of the present invention.

  FIG. 3a shows the microactuator 20 after assembly according to the first embodiment of the present invention. The microactuator 20 includes a thin film PZT 21 and a metal frame 22, and the thin film PZT 21 is attached to the metal frame 22. Hereinafter, the structure and assembly process of the thin film PZT 21 and the metal frame 22 will be described in detail.

  FIG. 3 b shows a thin film PZT 21 used for the microactuator 22. The thin film PZT 21 includes a first thin film PZT piece 211 and a second thin film PZT piece 212. By connecting these through a flexible polymer substrate 213, the thin film PZT 21 is connected in the vertical direction (in series). The first and second thin film PZT pieces 211 and 212 are installed on the substrate 213 and separated from each other by a predetermined distance. In other words, the substrate 213 is a substrate shared by the two thin films PZT 211 and 212, and the ends of the two thin films PZT 211 and 212 face each other. An electrical trace (not shown) is formed on the substrate 213 and is used to electrically connect the two thin films PZT 211 and 212.

  FIG. 3c is a view showing the structure of the metal frame 22 according to the first embodiment of the present invention. The metal frame 22 is preferably made of a stainless material and includes a base portion 221 and two arms 222 extending from the base portion 221. The support part 223 is formed at the other end of the arm 222 facing the substrate 221. In other words, the two arms 222 are substantially perpendicular to the base part 221 and the support part 223 at each end thereof and extend from the base part 221 and the support part 223. In this embodiment, the metal frame 22 is formed by bending a single metal plate twice, and a gap 224 is formed in the middle of the base portion 221.

  FIG. 3 d is a side view of the metal frame 22. As seen from the drawing, the base part 221 is formed on a different plane from the support part 223, and a height step 225 is formed between the base part 221 and the support part 223 along the vertical direction. ing. This height difference is great for smooth movement of the front portion of the frame 22, as will be described later, when the base portion 221 is attached to the suspension tongue portion of the suspension of the HGA.

  FIG. 3e is a diagram showing a structural state of the thin film PZT 21 after being bent around the middle portion of the flexible substrate 213 made of a flexible polymer. Among them, the first and second thin film PZT pieces 211 and 212 are substantially parallel to each other, and an internal interval is formed between them. This internal spacing is applied to mounting the thin film PZT pieces on the outer and inner surfaces of the arms 222 of the metal frame 22.

  By attaching the bent thin film PZT 21 to the metal frame 22, the two thin film PZT pieces 211 and 212 are attached to the inner and outer surfaces of the arm 222, respectively, and the middle part 214 is located behind (or in front of) the arm 222. ) Cross over the edge. That is, when the arm 222 is sandwiched between two thin film PZT pieces 211 and 212, the microactuator 20 according to the first embodiment shown in FIG. 3A is formed.

  According to such a double-sided mounting structure, even when the actual number of layers of each thin film PZT is not increased, the number of equivalent working layers of the thin film PZT mounted on each arm is actually doubled. The displacement can be greatly increased. Thus, the displacement of the microactuator is a superposition of the displacement of the two thin films PZT 211 and 212 attached to each arm of the metal frame. More specifically, when the two-layer thin film PZT is mounted on the arm through the double-side mounting method, the number of equivalent layers of the thin film PZT in each arm is four. The displacement of the microactuator can be increased by a factor of 2, and thus the displacement can be increased at low cost and high efficiency.

  FIG. 3f shows another embodiment 22 ′ of the metal frame that can be used in the above embodiment, in which the gap 224 ′ is formed not on the base portion 221 ′ but on the support portion 223 ′ of the metal frame 22 ′. ing.

  The present embodiment of the present invention provides a microactuator formed by attaching a thin film PZT to a metal frame, which can reduce the total mass of the HGA and can provide static and dynamic HGA. In addition to improving performance, the thin film PZT is mounted on the inner and outer surfaces of each arm of the metal frame so that the magnetic head has sufficient displacement.

  4a to 4c show a second embodiment of the microactuator according to the present invention. More specifically, FIG. 4a is a view showing two thin film PZTs 31 used in the second embodiment of the microactuator. Among them, each thin film PZT 31 includes a first thin film PZT piece 311 and a second thin film PZT piece 312, and is connected through a substrate 313 along the horizontal direction (parallel). The first and second thin film PZT pieces 311 and 312 are placed on the substrate 313 and separated from each other by a predetermined distance. This second embodiment is different from the first embodiment in that the two thin film PZTs are connected to the common substrate 313 as described above, so that the sides of the two thin film PZTs are mutually connected. It is to make it conflict. Similarly, an electrical trace (not shown) is formed on the substrate 313 and used to electrically connect the two thin film PZTs.

  Since the metal frame 22 of the microactuator 30 in the second embodiment is the same as the metal frame according to the first embodiment, further description thereof is omitted. Similarly, another type of metal frame 22 'can be applied to the second embodiment.

  FIG. 4 b is a structural diagram showing a state after the two thin film PZTs 31 are bent at the middle part 314 of the substrate 313. In order to achieve the purpose of bending, the substrate 313 is preferably formed of a flexible polymer material. In such a bent state, the first and second thin film PZT pieces 311 and 312 are substantially parallel to each other, and an internal space is formed between them. This is applied to the outer and inner surfaces of the arm of the metal frame 22.

  FIG. 4 c is a view showing the structure of the microactuator according to the second embodiment formed by assembling the two thin film PZTs 31 and the metal frame 22. The microactuator is formed by the following method: In other words, the bent thin film PZT 31 is mounted on the metal frame 22 so that the two thin film PZT pieces 311 and 312 are separately mounted on the outer surface of each arm. At this time, the middle portion 314 crosses over the upper edge of the arm. That is, each arm of the metal frame 22 is sandwiched between the two thin film PZT pieces 311 and 312.

  Similarly, since the microactuator 30 in this second embodiment also has an increased number of equivalent thin film PZT layers, this can generate a polymerization effect of the displacement of the arm.

  It is clear to the engineers in this area that in the first and second embodiments of the present invention, two thin film PZTs mounted on the outer surface of each arm of the metal frame are connected via a substrate. However, the present invention is not limited to this. For example, the two thin film PZTs can be completely separated from each other and can be connected without passing through the substrate. In this case, the first thin film PZT piece and the second thin film PZT piece can be electrically connected to the suspension pad by their own suspension traces.

  FIG. 5 is a diagram showing simulation data corresponding to the PZT length and the number of layers of the PZT displacement. From the drawing, it becomes clear that the displacement of PZT increases as the number of PZT layers increases. Therefore, by increasing the number of equivalent layers of the thin film PZT attached to each arm, the displacement of the PZT can be effectively increased in the first and second embodiments of the present invention.

  On the other hand, according to FIG. 5, it is clear that the displacement of PZT is first increased as the length of PZT is increased, but is decreased as the length of PZT is further increased. The maximum displacement of the PZT is generated at a certain point of the PZT (according to FIG. 5, the length at which the maximum displacement is generated is about 1 mm). Based on such characteristics of PZT, the displacement of PZT can be increased by selecting an appropriate length for each thin film PZT piece.

  6a to 6c are views showing the structure of the microactuator and its thin film PZT according to the third embodiment of the present invention based on the above principle.

  FIG. 6 a shows the structure of the microactuator 40 after assembly in the third embodiment, and the microactuator includes a metal frame 22 and a thin film PZT piece 41. More specifically, FIG. 6 b shows the two thin film PZT pieces 41, each of which is constituted by a first thin film PZT piece 411 and a second thin film PZT piece 412, which are also interposed via a substrate 413. Connected. Thereby, the first and second thin film PZT pieces 411 and 412 are placed on the substrate 213 along the vertical direction (series). As shown in the figure, the arrangement of the thin film PZT piece 41 of the third embodiment is similar to that of the first embodiment. The third embodiment is different from the first embodiment in that the two thin film PZT pieces 41 are directly mounted on the outer surface of each arm of the metal frame 22 without bending. Similarly, an electrical trace (not shown) is formed on the substrate 413 and used to electrically connect the two thin film PZT pieces 411 and 412.

  Since the metal frame 22 of the microactuator in the third embodiment is the same as the metal frame in the first and second embodiments, further description thereof is omitted. Similarly, another type of metal frame 22 'can be applied to the third embodiment.

  In FIG. 6 a, only the two thin film PZT pieces 41 are separately attached to the outer surfaces of the two arms of the metal frame 22. Of course, the two thin film PZT pieces 41 are separately made of metal. It can also be attached to the inner surface of the two arms of the frame 22. If a polymerization effect can be generated, one thin film PZT piece 41 can be mounted on the inner surface of one arm, and the other can be mounted on the outer surface of another arm.

  Even if the optimum length of 1 mm as shown in FIG. 5 cannot be adopted for each thin film PZT piece 411, 412 in this embodiment due to the limitation of the total length of the microactuator arm, each thin film PZT piece 411, 412 is the best possible. By making the length long, the maximum displacement of each PZT piece can be realized. Since the thin film PZT pieces 411 and 412 are fixed to the arms of the metal frame 22, the displacement of each arm is a superposition of the displacement of the two thin film PZT pieces 411 and 412. That is, the displacement of the microactuator 40 can be increased also by the structure of the third embodiment.

  FIG. 7a is a diagram showing the overall structure of an HGA 50 including the microactuator 20 (or 30, 40) according to the present invention. In the suspension tongue portion 1831 of the HGA suspension 183, a microactuator 20 used for precise localization with respect to the magnetic head is disposed. FIG. 7 b is an enlarged view of the front portion of the suspension 183.

  7a and 7b, a slider 182 and at least one magnetic sensor (not shown) provided with at least one magnetic sensor by fixing the base portion of the metal frame of the microactuator 20 to the suspension tongue portion 1831 of the suspension 183. The assembly having 20 is installed on the suspension tongue 1831 of the suspension 183. The slider 182 is mounted between the two arms of the microactuator and is displaced according to a drive signal applied to the thin film PZT. The slider 182 is electrically connected to the suspension pad 187 via gold ball welding (GBB) or solder ball welding (SBB) 186 and a suspension trace 184. The thin film PZT is also electrically connected to the suspension pad 187 via the suspension trace 184. Here, since the technique for electrical connection is well known to those skilled in the art, a detailed description thereof will be omitted. In the above embodiment, the drive signal is applied to all the thin film PZT pieces of each arm of the metal frame. However, when the displacement of the arm by a part of the thin film PZT is sufficient, only one of the metal frames is provided. It is also possible to apply a drive signal to the two thin film PZT of the arm and not apply a drive signal to the other arms.

  FIG. 7 c is a side view of the microactuator 20 installed on the suspension tongue 1831 of the suspension 183. The metal frame 22 supports the slider 182 through the support portion 223, and the base portion 221 is partially attached to the suspension tongue 1831 through an insulating layer made of a polymer material or the like. The protrusion 501 of the suspension load beam 502 supports the suspension tongue 1831. As described above, when a voltage is applied to the thin film PZT, the slider 182 moves smoothly due to the gap 225 of about 30 to 50 μm formed between the suspension tongue 1831 and the bottom surface of the support 223 of the metal frame 22. Secure.

  Of course, the HGA according to the present invention is not limited to the above structure. Although not shown here, a magnetic head driving IC chip can also be mounted in the middle of the suspension 183.

  FIG. 8c is a flowchart showing a manufacturing process of the HGA according to the present invention.

  This manufacturing process starts from step 601. In step 602, the two thin film PZTs are respectively attached to the outer surfaces of the arms of the metal frame, thereby forming the microactuator disclosed in the first or second embodiment. Next, in step 603, a slider provided with a magnetic sensor is attached to the microactuator. In step 604, the base portion of the microactuator is mounted on the suspension tongue portion of the head gimbal assembly, thereby mounting the assembly including the slider and the microactuator thereon. Next, in step 605, the microactuator is electrically connected to the suspension pad via the suspension trace, and the slider is electrically connected to the suspension pad. Finally, in step 606, the manufacturing process is terminated, and the HGA according to the present invention is manufactured.

  It should be noted that after the HGA is completed, the performance of the mounted slider and thin film PZT can be tested.

  Alternatively, the HGA according to the present invention can be manufactured by a different process. In this manufacturing process, the step of attaching the metal frame of the microactuator to the suspension is performed before the step of attaching the PZT thin film to the arm of the metal frame and the step of attaching the slider to the microactuator.

  In the manufacturing process described above, the step of attaching the thin film PZT to the side surfaces of the two arms of the metal frame includes: (1) Two thin film PZTs mechanically and electrically coupled via the substrate. Providing two thin film PZTs constituted by: (2) by bending each thin film PZT in the middle of the substrate, the two thin film PZTs constituting each thin film PZT And (3) mounting the two thin film PZTs after bending on the outer and inner surfaces of one arm, respectively, so that each arm has the two thin film PZTs. And a step of sandwiching between the two.

  On the other hand, another manufacturing process for forming the HGA having the microactuator 40 in the third embodiment is as follows. First, two thin film PZTs are mounted on the same surface of each arm of the metal frame in a serial manner to form the microactuator in the third embodiment. Then, a slider equipped with a magnetic sensor is mounted in the microactuator. Next, the base portion of the metal frame is fixed to the suspension tongue portion of the suspension, thereby attaching the microactuator to the suspension. Then, the microactuator and the suspension, and the slider provided with the magnetic sensor and the suspension are electrically joined. Since this manufacturing process is similar to the process shown in FIG. 8, the flow is not shown in other drawings. Similarly, also in this manufacturing process, before attaching the PZT thin film to the arm of the metal frame and attaching the slider to the microactuator, first, the metal frame of the microactuator can be attached to the suspension.

  FIG. 9 is a diagram showing an HDD 80 using the thin film PZT microactuator 20, 30 or 40 according to the present invention. The HDD 80 includes a housing 801, a disk 802 accommodated in the housing 801, a pivot center 803, and a VCM 804, in which the disk includes a pivot center 803 in the housing. The VCM 804 is rotated about the center and drives the HGA 50 connected to the VCM 804 so as to move on the surface of the disk 802. The HGA 50 may include a microactuator 20, 30 or 40 according to the present invention.

  Of course, in the above embodiment, the microactuator is used in the HGA of the disk drive unit. However, the present invention is not limited to this, and can be used in other devices that require displacement adjustment. In addition, the present invention is intended to include such modifications and changes without departing from the technical idea thereof. For example, by combining the first and third embodiments in any other manner, two or more thin film PZTs can be mounted on the side surface of each arm of the metal frame, that is, each arm One or more thin films PZT are installed on the outer and inner surfaces, respectively, so that a larger displacement can be obtained by the polymerization effect.

FIG. 1 is a diagram showing a typical disk drive using a conventional microactuator for localization control of a magnetic head. FIG. 2a is a detailed diagram illustrating the structure of the HGA shown in FIG. FIG. 2b shows a conventional microactuator in detail. 3a to 3f are views showing a microactuator according to a first embodiment of the present invention, its components, and variations thereof. 4a to 4c are views showing a microactuator and its components according to a second embodiment of the present invention. FIG. 5 is a diagram showing simulation data of PZT displacement corresponding to the length and the number of layers of PZT. 6a to 6b are views showing a microactuator and its components according to a third embodiment of the present invention. FIG. 7a is a structural diagram of an HGA having a microactuator according to the present invention. FIG. 7b is a perspective view showing in detail the front part of the suspension of the HGA shown in FIG. 7a. FIG. 7c is a side view of the front portion of the suspension of the HGA shown in FIG. 7a, in which the microactuator according to the present invention is arranged. FIG. 8 is a flowchart illustrating a process of manufacturing an HGA according to the present invention. FIG. 9 shows a disk drive unit using the microactuator according to the present invention.

Claims (13)

A microactuator comprising a base and a metal frame having two relative arms extending from the base,
When each arm and the thin film PZT mounted thereon are displaced according to a driving signal applied to the thin film PZT, the side surface of each arm is increased so that the displacement of each arm is increased by the polymerization effect. The microactuator is characterized in that at least two thin film PZTs are mounted separately.   2. The microactuator according to claim 1, wherein the at least two thin film PZTs are separately mounted on the outer and inner surfaces of each arm.   3. The microactuator according to claim 2, wherein the at least two thin film PZTs mounted on the outer and inner surfaces of each arm are mechanically and electrically connected via a substrate. .   The common substrate of the at least two thin film PZTs is bent so that the at least two thin film PZTs are located on both sides of the arm, so that it straddles the front end or the rear end of the arm. 4. The microactuator according to claim 3, wherein the at least two thin film PZTs are connected via a substrate.   The common substrate of the at least two thin film PZTs is bent so that the at least two thin film PZTs are positioned on both sides of the arm so that the substrate straddles the upper edge of the arm. 4. The microactuator according to claim 3, wherein at least two thin film PZTs are connected via each other.   2. The microactuator according to claim 1, wherein the at least two thin film PZTs are mounted on the same side surface of each arm in a series manner.   The microactuator according to claim 6, wherein the at least two thin film PZTs mounted on the same side surface of each arm are mechanically and electrically connected to each other through a substrate.   4. The substrate is formed of a flexible polymer material, and electric traces for electrically connecting the at least two thin film PZTs are formed thereon. Or the microactuator of 7. Including the microactuator according to any one of claims 1 to 8, a slider, and a suspension;
The slider includes at least one magnetic sensor, is housed in a metal frame and is driven by the microactuator,
The suspension is provided with the microactuator on the suspension by fixing the base portion of the metal frame to the suspension tongue portion, so that the two arms and the slider can move independently with respect to the suspension. Head gimbal assembly characterized by A disc,
A pivot center and the disk rotates about the pivot center;
A VCM for driving the magnetic head to move on the disk surface;
A head gimbal assembly connected to the VCM and used for adjusting displacement of a magnetic head, and an information recording disk unit,
9. The disk unit according to claim 1, wherein the head gimbal assembly includes the microactuator according to any one of claims 1 to 8. Attaching two thin film PZTs to the outer and inner surfaces of each arm to form a microactuator according to claim 2;
Attaching a slider with a magnetic sensor to the microactuator;
Attaching the microactuator to the suspension by fixing the base portion of the metal frame to the suspension tongue of the suspension;
Electrically bonding the microactuator and the suspension, and a slider including the magnetic sensor and the suspension;
A method for manufacturing a head gimbal assembly, comprising: The step of attaching the two thin film PZTs to the outer and inner surfaces of each arm, respectively,
Providing two thin film PZTs composed of two thin film PZTs mechanically and electrically connected through a substrate;
Bending each thin film PZT at the center of the substrate so that the two thin film PZTs constituting each thin film PZT are substantially parallel to each other;
The two thin film PZTs that are bent between the two thin film PZTs after the respective arms are bent and the substrate is straddled between the arms are separately attached to the outer and inner sides of each arm. The method for manufacturing the head gimbal assembly according to claim 11, further comprising a step of attaching to the surface of the head gimbal assembly. Forming the microactuator according to claim 6 by mounting two thin film PZTs on the same side surface of each arm in a series manner;
Mounting a slider with a magnetic sensor in the microactuator;
Attaching the microactuator to the suspension by fixing the base portion of the metal frame to the suspension tongue of the suspension;
Electrically joining the microactuator and the suspension, and a slider comprising the magnetic sensor and the suspension;
A method for manufacturing a head gimbal assembly, comprising:

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