JP6067347B2 - Manufacturing method of head gimbal assembly, manufacturing method of flexure constituting the same, and flexure sheet used for manufacturing head gimbal assembly and flexure - Google Patents

Description

  The present invention relates to a method for manufacturing a head gimbal assembly on which a head slider on which a thin film magnetic head is formed is mounted, a method for manufacturing a flexure constituting the head gimbal assembly, and a flexure sheet used for manufacturing the head gimbal assembly and the flexure.

  A hard disk device has a large recording capacity and is widely used as the center of a storage device. The hard disk device records and reproduces data with respect to a hard disk (recording medium) by a thin film magnetic head. A component on which the thin film magnetic head is formed is called a head slider, and a component on which the head slider is mounted at the tip is a head gimbal assembly (also referred to as HGA).

  In the hard disk device, the head slider is floated from the surface of the recording medium while rotating the recording medium, thereby recording and reproducing data on the recording medium.

  On the other hand, since the recording density of recording media has increased with the increase in capacity of hard disk drives, it is difficult to control the position of the thin-film magnetic head accurately using only the voice coil motor (hereinafter also referred to as “VCM”). Became. Therefore, conventionally, a technique is known in which an auxiliary actuator (auxiliary actuator) is mounted on the HGA in addition to the main actuator by VCM, and minute position control that cannot be controlled by VCM is performed by the auxiliary actuator.

  The technique for controlling the position of the thin film magnetic head by the main actuator and the auxiliary actuator is also called a two-stage actuator system (dual stage system).

  In the two-stage actuator system, the main actuator rotates the drive arm to position the head slider on a specific track of the recording medium. The auxiliary actuator finely adjusts the position of the head slider so that the position of the thin film magnetic head is optimized. Such a two-stage actuator system is disclosed in, for example, Patent Literature 1, Patent Literature 2, Patent Literature 3, Patent Literature 4, Patent Literature 5, and the like.

  Conventionally, a microactuator using a piezoelectric element (for example, a PZT element) is known as an auxiliary actuator, and there are roughly two types called a millitype and a microtype. In any case, by using a piezoelectric element, track tracking and searching can be performed with high accuracy.

  The millimeter type uses a pair of bulk PZT elements. These PZT elements are placed on a base plate. For the micro type, a pair of thin film PZT elements or a pair of bulk PZT elements are used. These PZT elements are placed on a gimbal. In any type, in the HGA, the PZT element is mounted on the suspension.

JP 2002-133803 A JP 2008-152908 A JP 2007-317349 A JP 2011-66321 A JP 2008-140536 A

  In the conventional microactuator described above, a pair of PZT elements are used. Each of them is controlled by applying the same AC signal or an AC signal of opposite phase.

  However, the pair of PZT elements must operate in opposite directions even when the same AC control signal is applied. That is, when the control signal is a positive voltage, if one PZT element extends to push the head slider, the other PZT element must contract to pull the head slider back. If the control signal is a negative voltage, expansion and contraction must be interchanged in each PZT element.

  Moreover, the performance of both PZT elements must be maintained with good controllability and operating range in common.

  However, a conventional HGA is manufactured by fixing a flexure to a suspension support plate and a slider support plate on a load beam, and then fixing a pair of PZT elements to the flexure. Therefore, the conventional HGA has not solved the following problems.

  A conventional HGA has a suspension 301 and a head slider 302, for example, as an HGA 300 shown in FIG. The suspension 301 includes a load beam 303, a slider support plate 304, a flexure support plate 305, a flexure 306, and a pair of PZT elements 307a and 307b. The PZT elements 307a and 307b are fixed to the tongue region 306a of the flexure 306.

  The HGA 300 is manufactured by bonding the flexure 306 to the slider support plate 304 and the suspension support plate 305 on the load beam 303 and then fixing the PZT elements 307 a and 307 b to the flexure 306.

  However, in the HGA 300, as shown in FIG. 18, the slider support plate 304 is supported by the dimples 303a of the load beam 303, while the flexure support plate 305 is disposed at a position away from the dimples 303a.

  At this time, the portion (the tongue region 306a) to which the PZT elements 307a and 307b of the flexure 306 are fixed is bent or waved, and the surface thereof is not flat. In addition, the bending or undulation of the portion to which the PZT element 307a is fixed differs from the bending or undulation of the portion to which the PZT element 307b is fixed.

  In the HGA 300, since the PZT elements 307a and 307b are fixed to the flexure 306 in such a state, a gap is easily formed between the PZT elements 307a and 307b and the surface of the flexure 306 after the fixing. Moreover, the gap that can be formed in the PZT element 307a is different from the gap that can be formed in the PZT element 307b. Therefore, there is a difference between the fixed state of the PZT element 307a and the fixed state of the PZT element 307b. Therefore, it is difficult to increase the commonness of the operation performance in both, and it is also possible to maintain the common operation performance. could not.

  Further, since the flexure 306 is formed using a flexible material, the suspension 301 is easily deformed in the tongue region 306a. In particular, in the HGA 300, since the flexure 306 is fixed so that the tongue region 306a straddles the slider support plate 304 and the flexure support plate 305, the suspension 301 is easily deformed.

  However, when the suspension 301 is deformed, the tongue region 306a is not always bent in the same manner. For this reason, there is a possibility that a mismatch occurs in the deformation size or the like of the PZT elements 307a and 307b fixed to the tongue region 306a, and the commonality of the operation performance may not be maintained.

  In order to solve such a problem, there is an idea of mounting a fixing member on the lower side of the flexure 306 (on the load beam 303 side) so that the deformation in the tongue region 306a of the suspension 301 does not occur.

  However, in the HGA 300, it is difficult to secure a mounting space for the fixing member below the flexure 306. Therefore, in the HGA 300, it is difficult to maintain the commonality in the operation performance of the PZT elements 307a and 307b with high accuracy.

  On the other hand, in the conventional HGA, each PZT element is provided with a member for keeping the operation performance common.

  However, when factors such as temperature and humidity change due to environmental changes, the characteristics (for example, expansion characteristics) of the member may differ between one PZT element and the other PZT element. . In this case, there is also a problem that it becomes difficult to maintain the commonality of the operation performance because the operation performance of each PZT element is different.

  Accordingly, the present invention has been made to solve the above-described problems, and a method of manufacturing a head gimbal assembly that controls the position of a head slider by a two-stage actuator system, a method of manufacturing a flexure constituting the head gimbal assembly, and a head gimbal assembly Another object of the present invention is to increase the accuracy of commonality in the operational performance of each of a pair of piezoelectric elements and to maintain the same operational performance in each flexure sheet used for flexure manufacture.

In order to solve the above-described problems, the present invention provides a method for manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension that supports the head slider. In the flexure manufacturing process for manufacturing the piezoelectric element, on the surface of the base insulating layer formed on the flexure substrate serving as the base of the flexure, a piezoelectric element and an upper insulating layer formed on each of the upper and lower sides of the piezoelectric element, and A flexure with a piezoelectric element is manufactured by fixing a pair of piezoelectric element portions having a common structure in which the upper insulating layer and the lower insulating layer have the same material and dimensions, and the piezoelectric element includes the lower insulating layer. The suspension is manufactured by joining the flexure with the tip to the load beam and the base plate. And suspension manufacturing process features a method of making a head gimbal assembly having a slider mounting step of mounting the head slider to the suspension.

  In this manufacturing method, the flexure with a piezoelectric element is manufactured in the flexure manufacturing process, and it is joined to the load beam and the base plate in the suspension manufacturing process. Therefore, after the flexure with the piezoelectric element is joined to the load beam and the base plate, Separately, the head gimbal assembly is manufactured without fixing the piezoelectric element portion. At this time, it is desirable to short-circuit the signal terminals for controlling the piezoelectric elements of the flexure with piezoelectric elements in order to prevent ESD (electrostatic breakdown).

The present invention also relates to a method of manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension that supports the head slider, and manufacturing the flexure to which the head slider is mounted. For the base sheet in which the base insulating layer is formed on at least one surface, each of the piezoelectric element and the piezoelectric element on the surface of the base insulating layer in the base area surrounded by the base line indicating the outer shape of the flexure An upper insulating layer and a lower insulating layer formed on the upper and lower sides, respectively, and the upper insulating layer and the lower insulating layer are fixed to a pair of piezoelectric element portions having a common structure with common materials and dimensions. A flexure sheet manufacturing process for manufacturing a flexure sheet with a piezoelectric element, and A cutting process for manufacturing a flexure with a piezoelectric element by cutting out a base area from a flexure sheet, and a suspension manufacturing process for manufacturing a suspension by joining the flexure with a piezoelectric element to a load beam and a base plate; There is provided a method for manufacturing a head gimbal assembly including a slider mounting step for mounting a head slider.

  Also in this manufacturing method, after the flexure with a piezoelectric element is joined to the load beam and the base plate, the head gimbal assembly is manufactured without fixing the piezoelectric element portion separately. The flexure with a piezoelectric element is manufactured by fixing a pair of piezoelectric element portions to the surface of the base insulating layer in the base area of the base sheet.

  In the case of the above manufacturing method, in the flexure sheet manufacturing process, a multi-base sheet in which a plurality of base areas are formed is used as the base sheet. The flexure sheet is manufactured by fixing the parts, and in the cutting process, a plurality of flexures with piezoelectric elements are manufactured by cutting out the respective base areas from the flexure sheet. In the suspension manufacturing process, each flexure sheet with piezoelectric elements is manufactured. It is preferable that a plurality of suspensions are manufactured by joining each to another load beam and a base plate, and a head slider is mounted on each suspension in the slider mounting step.

  In the case of this manufacturing method, a plurality of flexures with piezoelectric elements can be manufactured at a time by using a multi-base sheet in the flexure sheet manufacturing process.

  Further, in the case of the above manufacturing method, the flexure manufacturing process forms a metal sheet in which a base area is formed so as to be connected to the outer frame inside the outer frame, and is formed on at least one surface of the metal sheet. A base sheet manufacturing process for manufacturing the base sheet is further formed by forming the base insulating layer, and the flexure sheet manufacturing process manufactures the flexure sheet using the base sheet manufactured by the base sheet manufacturing process. It is preferable.

  Further, the flexure manufacturing process includes a wiring forming process for forming a connection wiring connected to the pair of piezoelectric element portions or the head slider on the surface of the base insulating layer, and a protective insulating layer formation for forming a protective insulating layer covering the connection wiring. In the protective insulating layer forming step, the protective insulating layer is preferably formed so as to cover the pair of piezoelectric element portions together with the connection wiring.

According to another aspect of the present invention, there is provided a flexure manufacturing method used for manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension for supporting the head slider. The manufacturing method of the flexure which has the process shown to (2) is provided.
(1) For a base sheet having a base insulating layer formed on at least one surface, a piezoelectric element and a piezoelectric element on the surface of the base insulating layer in the base area surrounded by the base line indicating the outer shape of the flexure An upper insulating layer and a lower insulating layer formed on the upper and lower sides, respectively, and the upper insulating layer and the lower insulating layer are fixed to a pair of piezoelectric element portions having a common structure with common materials and dimensions. A flexure sheet manufacturing process for manufacturing a flexure sheet with a piezoelectric element, and (2) a cutting process for manufacturing a flexure with a piezoelectric element by cutting out a base area from the flexure sheet

  The manufacturing method uses a multi-base sheet in which a plurality of base areas are formed as a base sheet in the flexure sheet manufacturing process, and the multi-base sheet has a pair of piezoelectric element portions on the surface of the base insulating layer in each base area. It is preferable to manufacture a plurality of flexures with piezoelectric elements by manufacturing a flexure sheet by sticking and cutting out each base area from the flexure sheet in the cutting step.

  Further, in the manufacturing method, a metal sheet having a base area formed so as to be connected to the outer frame is formed inside the outer frame, and a base insulating layer is formed on at least one surface of the metal sheet. Accordingly, it is preferable to further include a base sheet manufacturing process for manufacturing the base sheet, and the flexure sheet manufacturing process preferably uses the base sheet manufactured by the base sheet manufacturing process to manufacture the flexure sheet.

The present invention provides a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension for supporting the head slider, wherein the suspension has a base insulating layer on at least one surface of the flexure substrate. The flexure has a structure with a piezoelectric element in which a pair of piezoelectric element portions each having a piezoelectric element are fixed on the base insulating layer, and the pair of piezoelectric element portions or the head slider And a protective insulating layer formed on the surface of the base insulating layer so as to cover the connection wiring and the pair of piezoelectric element portions, and the pair of piezoelectric element portions are internally provided along with the connection wiring. Each of the piezoelectric element portions has an upper insulating layer and an upper insulating layer on each of the upper and lower sides of the piezoelectric element. Has a lower insulating layer, the upper insulating layer and the lower insulating layer provides a head gimbal assembly having a common structure materials and dimensions are common.

The present invention also provides a flexure sheet for use in manufacturing a flexure that constitutes a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension that supports the head slider. For a rectangular base sheet made of a metal material with a base insulating layer formed on the surface, a plurality of base areas surrounded by a base line indicating the outer shape of the flexure are formed, and on the surface of the base insulating layer in each base area Each having a piezoelectric element and an upper insulating layer and a lower insulating layer formed on the upper and lower sides of the piezoelectric element, respectively, and the upper insulating layer and the lower insulating layer are common in material and size. Provided is a flexure sheet to which a pair of piezoelectric element portions having a structure are fixed.

  In the case of the flexure sheet, the base sheet has a base insulating layer formed on at least one surface of a metal sheet in which a plurality of base areas are formed so as to be connected to the outer frame inside the outer frame. Preferably it is.

  Further, a connection wiring connected to the pair of piezoelectric element portions or the head slider is formed on the surface of the base insulating layer, and further includes a protective insulating layer formed so as to cover the pair of piezoelectric element portions together with the connection wiring. preferable.

  As described above in detail, according to the present invention, a method of manufacturing a head gimbal assembly that controls the position of the head slider by using a two-stage actuator system, a method of manufacturing a flexure constituting the head gimbal assembly, and a head gimbal assembly and flexure are manufactured. In the flexure sheet used, it is possible to increase the accuracy of the commonality in the operation performance of each of the pair of piezoelectric elements and to maintain the same operation performance of each piezoelectric element.

It is the perspective view which looked at the whole HGA concerning an embodiment of the invention from the front side. It is the perspective view which looked at the principal part of HGA of Drawing 1 from the front side. It is the perspective view which looked at the principal part of the suspension which comprises HGA of Drawing 1 from the front side. It is the perspective view which looked at the whole HGA of FIG. 1 from the back side. It is the perspective view which looked at the flexure which concerns on embodiment of this invention from the front side. Similarly, it is the perspective view which looked at the principal part of the flexure from the front side. Similarly, it is the perspective view which expanded and showed the part to which the piezoelectric element part of a flexure was fixed. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7. It is sectional drawing to which the part enclosed by c9 of FIG. 8 was expanded. FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. It is the top view which showed typically the metal sheet used for manufacture of the flexure which concerns on embodiment of this invention. Similarly, it is the top view which showed the base sheet typically. Similarly, it is the top view which showed the flexure sheet | seat typically. Similarly, it is the top view which showed typically the flexure sheet | seat in which the connection wiring was formed. (A) is the sectional view on the 15a-15a line of FIG. 12, (b) is the sectional view on the 15b-15b line of FIG. 1 is a perspective view showing a hard disk device including an HGA according to an embodiment of the present invention. It is a disassembled perspective view which shows an example of the conventional HGA. Similarly, it is a side view.

Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is used for the same element and the overlapping description is abbreviate | omitted.
(HGA structure)
First, the structure of the HGA according to the embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a perspective view of the entire HGA 1 according to the embodiment of the present invention as viewed from the front side, and FIG. 2 is a perspective view of the main part of the HGA 1 as viewed from the front side. 3 is a perspective view of the main part of the suspension 50 constituting the HGA 1 as viewed from the front side, and FIG. 4 is a perspective view of the entire HGA 1 as viewed from the back side.

  Since the HGA 1 is manufactured using the flexure 6 having a structure with a piezoelectric element shown in FIGS. 5 to 10, a gap due to the shape of the surface of the flexure such as a conventional HGA is not formed. 5 is a perspective view of the flexure 6 viewed from the front side, and FIG. 6 is a perspective view of the main part viewed from the front side. FIG. 7 is an enlarged perspective view showing a portion where the piezoelectric element portion 12b of the flexure 6 is fixed. 8 is a cross-sectional view taken along line 8-8 in FIG. 7, and FIG. 9 is an enlarged cross-sectional view of a portion surrounded by c9 in FIG. 10 is a cross-sectional view taken along line 10-10 of FIG.

  The HGA 1 has a suspension 50 and a head slider 60 as shown in FIGS. The suspension 50 includes a base plate 2, a load beam 3, a flexure 6, and a damper 7, and has a structure in which these are joined and integrated by welding or the like.

  The base plate 2 is a component for fixing the suspension 50 to a drive arm 209 of the hard disk device 201 described later, and is formed using a metal such as stainless steel.

  A load beam 3 is fixed to the base plate 2. As shown in detail in FIG. 4, the load beam 3 has a shape in which the width gradually decreases as the distance from the base plate 2 increases. The load beam 3 has a load bending portion that generates a force for pressing the head slider 60 against a hard disk 202 (to be described later) of the hard disk device 201.

  As shown in FIGS. 1 to 3, the flexure 6 includes a flexure substrate 4, a base insulating layer 5, a connection wiring 11, and piezoelectric element portions 12a and 12b, and a protective insulating layer described later. 25 (not shown in FIGS. 1 to 7, see FIG. 8). In the flexure 6, the base insulating layer 5 is formed on the flexure substrate 4, and the connection wiring 11 and the piezoelectric element portions 12a and 12b are fixed thereon. Furthermore, a protective insulating layer 25 is formed so as to cover the connection wiring 11 and the piezoelectric element portions 12a and 12b.

  The flexure 6 has a structure with a piezoelectric element that is provided with a piezoelectric element by bonding the piezoelectric element portions 12 a and 12 b to the surface of the base insulating layer 5 in addition to the connection wiring 11.

  The flexure 6 has a gimbal portion 10 on the tip side (load beam 3 side). The gimbal portion 10 is secured with a tongue portion 19 on which the head slider 60 is mounted, and a plurality of connection pads 20 are formed on the tip side of the tongue portion 19. The connection pad 20 is electrically connected to an electrode pad (not shown) of the head slider 60.

  The flexure 6 expands and contracts the piezoelectric element portions 12 a and 12 b, and accordingly expands and contracts a stainless steel portion (also referred to as an outrigger portion) that protrudes outside the tongue portion 19. As a result, the position of the head slider 60 moves very slightly around a dimple (not shown), so that minute position control of the head slider 60 is performed.

  The flexure substrate 4 is a substrate that supports the entire flexure 6 and is formed using stainless steel. The back surface is fixed to the base plate 2 and the load beam 3 by welding. As shown in FIG. 1, the flexure substrate 4 has a center portion 4 a that is fixed to the surfaces of the load beam 3 and the base plate 2, and a wiring portion 4 b that extends outward from the base plate 2.

  The base insulating layer 5 covers the surface of the flexure substrate 4. The base insulating layer 5 is formed using polyimide, for example, and has a thickness of about 5 μm to 10 μm. Further, as shown in detail in FIG. 3, the insulating base layer 5 is divided into two portions, the first wiring portion 5a and the other wiring portion 5b. It has become. The piezoelectric element portion 12a and the piezoelectric element portion 12b are fixed to the respective surfaces.

  The first wiring portion 5a and the second wiring portion 5b are each provided with a non-existing zone 5c where the flexure substrate 4 does not exist as shown in detail in FIGS. The part corresponding to the non-existing zone 5c is missing). The piezoelectric element portion 12a and the piezoelectric element portion 12b are fixed so as to straddle the absence zone 5c. Note that the nonexistence zone 5c where the flexure substrate 4 does not exist expands and contracts, so that the head slider 60 can be moved with high precision.

  Further, in each of the first wiring portion 5a and the second wiring portion 5b, the nonexistence zone 5c is slightly inclined. That is, as for the second wiring portion 5b, the portion sandwiched between the dotted lines L1 and L2 shown in FIG. 7 in the nonexisting zone 5c is from the dotted line L1 side (base plate 2 side) as shown in FIG. It is inclined so as to rise slightly toward the dotted line L2 side (head slider 60 side) (this inclination is also referred to as a minute upward inclination). A portion sandwiched between the dotted lines L1 and L2 is also referred to as an inclined portion.

  A plurality of connection wirings 11 are formed on the respective surfaces of the first wiring part 5a and the second wiring part 5b. Each connection wiring 11 is formed using a conductor such as copper. Each connection wire 11 has one end connected to the piezoelectric element portions 12 a and 12 b or each connection pad 20.

  As shown in FIG. 9, the piezoelectric element portion 12b (the same applies to the piezoelectric element portion 12a) has cover insulating layers 13 and 15 formed on the upper and lower surfaces of the PZT element 14 with the electrode layers 17a and 17b interposed therebetween, respectively. It has a structure.

  The piezoelectric element portions 12b and 12a are fixed to the surface of the base insulating layer 5 using an epoxy resin. This epoxy resin constitutes an epoxy resin layer 16 (thickness of about 1 μm) shown in FIG.

The piezoelectric element portion 12b has a structure in which the upper side and the lower side are symmetrical with respect to the PZT element 14. That is, the insulating cover layers 13 and 15, the electrode layer 17a, and a 17b has a material, dimensions, any shape a common structure. The piezoelectric element portion 12b is formed in a substantially rectangular shape. Note that, like the piezoelectric element portion 12b shown in FIGS. 9 and 10, the piezoelectric element portion 12a also has a structure in which the upper side and the lower side are symmetrical with the PZT element 14 in between .

  The cover insulating layers 13 and 15 are both formed using polyimide, for example. Each of them has a thickness of about 1 μm to 2 μm, for example.

The PZT element 14 is a piezoelectric element using lead zirconate titanate (Pb (Zr, Ti) O ₃ ), and is formed in a thin film having a thickness of about 2 μm to 5 μm. Instead of using the PZT element 14, piezoelectric ceramics such as barium titanate and lead titanate (many of which are ferroelectrics) or non-leaded piezoelectric ceramics containing no titanium or lead can be used.

  In the electrode layers 17a and 17b, wiring (not shown) connected to the PZT element 14 is formed. These wirings are connected to the connection wiring 11 through the electrode pads 18a and 18b.

  As shown in FIG. 10, the protective insulating layer 25 covers the surface of the base insulating layer 5 so as to cover the entire surface of the connection wiring 11, the piezoelectric element portion 12a, and the piezoelectric element portion 12b. The protective insulating layer 25 is formed using polyimide, for example, and has a thickness of about 5 μm to 10 μm. The protective insulating layer 25 is preferably manufactured integrally with a cover layer (not shown) of the flexure 6. However, when the piezoelectric element portions 12a and 12b have a protective insulating layer in advance, the piezoelectric element portions 12a and 12b may not be covered with the protective insulating layer 25.

  The flexure 6 has a structure (piezoelectric element incorporation structure) in which the piezoelectric element portion 12a and the piezoelectric element portion 12b are incorporated together with the connection wiring 11 by forming the protective insulating layer 25 on the surface. ing.

  2, 3, and 5 to 7, for convenience of illustration, the connection wiring 11, the piezoelectric element portion 12 a, and the piezoelectric element portion 12 b are shown, but these are covered with the protective insulating layer 25. Therefore, it is not exposed on the surface of the flexure 6.

  The head slider 60 is formed with a thin film magnetic head (not shown) for recording and reproducing data. In addition, a plurality of electrode pads (not shown) are formed on the head slider 60, and each electrode pad is connected to the connection pad 20.

(Method for producing HGA)
Next, a method for manufacturing the HGA 1 having the above configuration will be described with reference to FIGS. 11 to 13 are plan views schematically showing the metal sheet 70, the base sheet 80, and the flexure sheet 90, respectively. FIG. 14 is a plan view schematically showing a flexure sheet 90 on which connection wiring is formed. 15A is a cross-sectional view taken along line 15a-15a in FIG. 12, and FIG. 15B is a cross-sectional view taken along line 15b-15b in FIG.

  The manufacturing method of the HGA 1 includes a flexure manufacturing process, a suspension manufacturing process, and a slider mounting process. Since each of the processes is characterized by a flexure manufacturing process, this process will be described in detail.

  The flexure manufacturing process is a process for manufacturing the flexure 6 described above, and includes a base sheet manufacturing process, a flexure sheet manufacturing process, a wiring forming process, a protective insulating layer forming process, and a cutting process. . Hereinafter, each process is demonstrated in order.

  The base sheet manufacturing process is a process for manufacturing the base sheet 80 shown in FIG. 12, and is specifically executed as follows.

  First, a metal sheet 70 as shown in FIG. 11 is formed using a stainless steel substrate that has a predetermined thickness (for example, about 20 μm) and has a flat front surface and back surface. The metal sheet 70 is a sheet-like member in which a stainless steel substrate is formed in a rectangular shape having a predetermined size, and includes an outer frame 70a, a plurality of base areas 71, a connecting portion 70b, and an intermediate line 70c. The area is divided into two upper and lower areas (each area is also referred to as a frame area) across the intermediate line 70c.

  A plurality (approximately 10) of base areas 71 are formed side by side in each area. Each base area 71 is disposed inside the outer frame 70a, and is connected to the outer frame 70a or the intermediate line 70c by the connecting portion 70b. In any area, a portion other than the base area 71 and the connection portion 70b is an unnecessary region 72.

  The base area 71 is an elongated region surrounded by a base line 71 a that indicates the outer shape of the flexure 6 described above, and is a portion that will later become the flexure substrate 4. The connecting portion 70 b is a portion that connects each base area 71 to the outer frame 70 a or the intermediate line 70 c, and the intermediate line 70 c is a portion that becomes a boundary between the upper and lower areas of the metal sheet 70.

  Next, the base sheet 80 is manufactured using the metal sheet 70 as shown in FIG. The base sheet 80 is a sheet-like member obtained by forming the base insulating layer 73 on the surface of the metal sheet 70 on the side where the base area 71 is drawn. The base sheet 80 has a configuration as a multi-base sheet in which a plurality of base areas 71 are formed.

  The base insulating layer 73 is formed using polyimide, for example, and has a thickness of about 5 μm to 10 μm. The insulating base layer 73 is a portion that will later become the insulating base layer 5. The insulating base layer 73 can be formed by applying polyimide to the surface of the metal sheet 70 and curing it.

  Subsequently, a flexure sheet manufacturing process is executed. This step is a step of manufacturing the flexure sheet 90 shown in FIG. 13, and is specifically executed as follows.

  That is, for the base sheet 80, the piezoelectric element portions 12a and 12b are fixed to the surface of the base insulating layer 73 in each base area 71 using an epoxy resin. The piezoelectric element portions 12a and 12b are fixed to portions of the base areas 71 that will become the tongue portions 19 later. As shown in FIG. 13, the flexure sheet 90 is a sheet-like member obtained by fixing the piezoelectric element portions 12 a and 12 b to the base areas 71 of the base sheet 80. The base sheet 80 can be formed using FPC (Flexible printed circuits). In this case, the flexure sheet 90 is a sheet-like member in which the base area 71 is formed in the FPC and the piezoelectric element portions 12 a and 12 b are fixed.

  Next, a wiring formation process is performed. This step is a step of forming the connection wiring 11 described above. As shown in FIG. 14, the connection wiring 11 is formed on the surface of the base insulating layer 73 of each base area 71. Then, electrode pads 18a and 18b are formed by solder bonding with a laser or the like, and the piezoelectric element portions 12a and 12b are connected to the connection wiring 11 and a ground line (not shown). The connection wiring 11 is formed as follows, for example.

  First, a thin film made of a metal such as copper is formed on the surface of the base insulating layer 73 in each base area 71. Next, a resist pattern corresponding to the connection wiring 11 is formed at a position where the connection wiring 11 is to be formed using a photoresist. Then, the portion of the thin film that is not covered with the resist pattern is removed by etching, and then the resist pattern is removed, whereby the connection wiring 11 can be formed.

  Thereafter, a protective insulating layer forming step is performed. In this step, the protective insulating layer 25 described above is formed. The protective insulating layer 25 is formed, for example, by applying polyimide to the surface of the flexure sheet 90 and curing it.

  As described above, before the protective insulating layer 25 is formed, the piezoelectric element portions 12 a and 12 b are fixed to the surface of the base sheet 80, so that the connection wiring 11 and the piezoelectric element portions 12 a and 12 b are connected to the surface of the flexure sheet 90. Is exposed. Therefore, the protective insulating layer 25 can be formed so as to cover them.

  Then, the flexure 6 with a piezoelectric element is manufactured by executing a cutting process. In this cutting process, each base area 71 is cut out from the flexure sheet 90 on which the protective insulating layer 25 is formed, and the flexure 6 with a piezoelectric element is manufactured.

  For example, after applying a photoresist on the flexure sheet 90, patterning is performed using a predetermined photomask. Thus, a resist pattern (not shown) that covers the base area 71 and exposes the other is formed on the flexure sheet 90.

  Subsequently, etching is performed using the resist pattern as a mask, and a portion of the flexure sheet 90 that is not covered with the resist pattern is removed. Then, each base area 71 can be cut out from the flexure sheet 90. In each base area 71, the connection wiring 11 is already formed, and the piezoelectric element portions 12a and 12b are fixed. Therefore, a plurality of flexures 6 with piezoelectric elements can be manufactured by cutting out each base area 71.

  This completes the flexure manufacturing process. Then, the suspension manufacturing process is executed. In this step, the suspension 50 is manufactured by joining the flexure 6 with a piezoelectric element to the load beam 3 and the base plate 2. In this case, since a plurality of flexures 6 with piezoelectric elements are manufactured in the flexure manufacturing process, each flexure 6 is joined to a separate load beam 3 and base plate 2. Thus, a plurality of suspensions 50 are manufactured.

  Following the suspension manufacturing process, a slider mounting process is performed. In this step, the head slider 60 is fixed to the tongue portion 19 of each suspension 50 manufactured in the steps described above. The HGA 1 can be manufactured through the above steps.

(Functional effects of HGA)
The HGA 1 manufactures the flexure 6 by cutting the base area 71 from the flexure sheet 90 before manufacturing the flexure to the load beam 3 and the base plate 2. Since the piezoelectric element portions 12 a and 12 b are fixed to the base area 71 of the flexure sheet 90, the flexure 6 has a structure with a piezoelectric element in the HGA 1.

  By the way, when a pair of piezoelectric elements is fixed to the flexure after the flexure is joined to the load beam and the base plate, the pair of piezoelectric elements is fixed to the tongue of the flexure.

  However, in this tongue portion, the surface of the protective insulating layer is inclined and is not a complete plane. Moreover, the inclined state of the surface on one piezoelectric element side and the surface on the other piezoelectric element side is not common. This is because, when the flexure is bonded to the load beam and the base plate, the height of the surface such as the base insulating layer 5 shown in FIG. 8 is increased on the base insulating layer and the protective insulating layer of the flexure due to the shape of the load beam. This is due to the difference in size. Since the difference in height is about 10 μm to 18 μm, it is about the same as or more than the thickness of the piezoelectric element portion (about 12 μm to 13 μm).

  Therefore, when the flexure is bonded to the load beam and the base plate as in the prior art, a pair of piezoelectric element portions are fixed to the surface of the flexure. It is easy to create a gap between the one piezoelectric element portion and the other piezoelectric element portion.

  In particular, as shown in FIG. 8, the direction of the base insulating layer 5 changes at a position (parts indicated by dotted lines L <b> 1 and L <b> 2 in FIG. 8) slightly away from the end facing the nonexistence zone 5 c of the flexure substrate 4. Therefore, when an HGA is manufactured with the piezoelectric element portion fixed so as to straddle the area as in the prior art, a portion that does not adhere to the base insulating layer is easily formed on the back surface of the piezoelectric element portion. Easy to do.

  Therefore, in the conventional HGA, a difference occurs in the fixing state of both piezoelectric element portions, and the fixing state cannot be made common.

  On the other hand, in the HGA 1 according to the present invention, since the flexure 6 has a structure with a piezoelectric element and is joined to the load beam 3 and the base plate 2, the piezoelectric element part 12a and the other piezoelectric element part 12b are connected. The fixed state can be made common.

  That is, the flexure 6 is manufactured by being cut out from the flexure sheet 90 with a piezoelectric element. Therefore, in the HGA 1, it is necessary to separately fix the piezoelectric element portion to the flexure after being bonded to the load beam and the base plate. There is no. Since the HGA 1 is manufactured without going through the process of fixing the piezoelectric element portion to the flexure, a gap due to the above-described inclination of the surface of the base insulating layer can be formed between the piezoelectric element portion and the surface of the flexure. Because there is no.

  Therefore, in the HGA 1, since the commonality of the mounting state of the piezoelectric element portion 12a and the piezoelectric element portion 12b is improved, the common performance of the PZT element 14 in both is improved. Therefore, in HGA1, the accuracy of commonality in the operational performance of the pair of PZT elements 14 and 14 can be increased, and the operational performance can be maintained common.

  Further, since the flexure sheet 90 is manufactured using the base sheet 80, a plurality of flexures 6 can be manufactured in a single process, and the manufacturing efficiency of the flexure 6 is enhanced.

  Further, the piezoelectric element portion 12 a and the piezoelectric element portion 12 b are incorporated into the flexure 6 by the protective insulating layer 25 of the flexure 6. The piezoelectric element portions 12a and 12b are less susceptible to external influences than when the piezoelectric element portions 12a and 12b are not incorporated into the flexure 6 (that is, formed outside the protective insulating layer 25).

  For this reason, the commonality in the operation performance of the pair of PZT elements 14 and 14 is not easily impaired by factors outside the flexure 6. Therefore, the HGA 1 can further improve the accuracy of commonality in the operational performance of the pair of PZT elements 14 and 14, and can more reliably maintain the common operational performance.

  On the other hand, in the piezoelectric element portion 12a and the piezoelectric element portion 12b, the cover insulating layers 13 and 15 and the electrode layers 17a and 17b are formed on the upper side and the lower side of the PZT element 14, respectively. It has a structure.

  In the conventional piezoelectric element portion, a layer (not shown) for maintaining strength and balance is formed in addition to the insulating cover layer and the electrode layer in order to increase the accuracy of commonality in operation performance.

  However, these layers are different from PZT in terms of expansion characteristics due to temperature and moisture absorption. Therefore, these layers may affect the expansion characteristics of the PZT element as the temperature and humidity vary.

  On the other hand, in the case of the HGA 1, since the accuracy of the commonality in the operation performance of the pair of PZT elements 14 and 14 is increased, a layer for maintaining the strength and balance of both is necessary for the piezoelectric element portions 12 a and 12 b. And not. In the piezoelectric element portions 12a and 12b, only the insulating cover layers 13 and 15 and the electrode layers 17a and 17b are formed on the upper and lower sides of the PZT element 14, respectively.

  Therefore, the pair of PZT elements 14 and 14 are not affected by the layer for maintaining the strength and balance. Thereby, in HGA1, the precision of the commonality in the operation performance of a pair of PZT elements 14 and 14 can be improved further, and common operation performance can also be maintained more reliably.

  In addition, since the layer for maintaining strength and balance is not affected by the deterioration over time, the pair of PZT elements 14 and 14 can more reliably maintain the common operation performance.

  In addition, since the piezoelectric element portions 12a and 12b are vertically symmetrical with respect to the PZT element 14, the external factor applied to the PZT element 14 is balanced between the upper side and the lower side of the PZT element 14. Be drunk.

  In addition, the manufacturing cost of the HGA 1 can be reduced because the layer for maintaining strength and balance is unnecessary.

  On the other hand, since the flexure 6 has a structure with a piezoelectric element, the manufacturing process of the dual stage HGA and the manufacturing process of the single stage HGA can be made common from the flexure joining process.

  In this regard, conventionally, when manufacturing a dual stage HGA, it has been necessary to perform a step of fixing the piezoelectric element portion after bonding the flexure.

  However, in the HGA of the present application, it is not necessary to perform the process of fixing the piezoelectric element portion after the flexure is joined, so that the commonality with the manufacturing process of the single stage HGA can be enhanced. Therefore, the cost of the entire HGA manufacturing process is reduced. In particular, in the HGA of the present application, an expensive facility for fixing the piezoelectric element portion to the flexure bonded to the load beam is not necessary, so that the manufacturing cost can be reduced.

  In addition, since the piezoelectric element portions 12a and 12b are long squares having the same shape, there is no difference between the two depending on the shape. Then, the piezoelectric element portions 12a and 12b do not need to be distinguished for one side and the other side, which improves the yield. However, the piezoelectric element portion does not need to be a long square like the piezoelectric element portions 12a and 12b, and can be generally trapezoidal as in the prior art. In this case, since the width on the tip side is reduced, the width of the HGA can be reduced.

(Modification)
In the above-described manufacturing process of the HGA, the base sheet 80 as a multi-base sheet is used. However, a base sheet (not shown) in which the size of the sheet is subdivided and only one base area 71 is formed is used. HGA can also be manufactured. Alternatively, the base sheet 80 may be prepared in advance, and the flexure sheet 90 may be formed by fixing the piezoelectric element portions 12 a and 12 b to the base area 71.

  Moreover, although the piezoelectric element portions 12a and 12b are fixed to the base sheet 80 and then the connection wiring 11 is formed, the order may be reversed. That is, the connection wiring 11 may be formed on the base sheet 80 first, and then the flexure sheet 90 may be formed by fixing the piezoelectric element portions 12 a and 12 b to the base sheet 80. The flexure sheet 90 has a structure as shown in FIG.

  In the base sheet 80 described above, the connection wiring 11 is not formed as shown in FIG.

  However, when the connection wiring 11 is formed earlier than the piezoelectric element portions 12a and 12b, the connection wiring 11 is formed first on the base sheet 80, although not shown. When manufacturing the HGA 1, the base sheet may not have the connection wiring 11 formed as in the base sheet 80 shown in FIG. 12, or the connection wiring 11 may be formed.

  The base sheet 80 has a frame area that is divided into two upper and lower stages across the intermediate line 70c. However, the frame area may be only one stage or may be divided into three or more stages.

(Embodiment of Head Gimbal Assembly and Hard Disk Device)
Next, an embodiment of a head gimbal assembly and a hard disk device will be described with reference to FIG.

  FIG. 16 is a perspective view showing a hard disk device 201 including the above-described HGA 1. The hard disk device 201 includes a hard disk (magnetic recording medium) 202 that rotates at a high speed and the HGA 1. The hard disk device 201 is a device that operates the HGA 1 to record and reproduce data on the recording surface of the hard disk 202. The hard disk 202 has a plurality of disks (four in the figure). Each disk has a recording surface facing the head slider 60.

  The hard disk device 201 positions the head slider 60 on the track by the assembly carriage device 203. A thin film magnetic head (not shown) is formed on the head slider 60. In addition, the hard disk device 201 has a plurality of drive arms 209. Each drive arm 209 is rotated about a pivot bearing shaft 206 by a voice coil motor (VCM) 205 and stacked in a direction along the pivot bearing shaft 206. An HGA 1 is attached to the tip of each drive arm 209.

  Further, the hard disk device 201 has a control circuit 204 that controls recording and reproduction.

  When the hard disk device 201 rotates the HGA 1, the head slider 60 moves in the radial direction of the hard disk 202, that is, in the direction crossing the track line.

  Since the HGA 1 and the hard disk device 201 have the flexure 6 having a structure with a piezoelectric element, it is possible to increase the accuracy of commonality in the operation performance of each of the pair of PZT elements 14. In addition, the PZT elements 14 can maintain common operating performance.

  The above description is the description of the embodiment of the present invention, and does not limit the apparatus and method of the present invention, and various modifications can be easily implemented. In addition, an apparatus or method configured by appropriately combining components, functions, features, or method steps in each embodiment is also included in the present invention.

  By applying the present invention, it is possible to increase the accuracy of commonality in the operational performance of each of the pair of piezoelectric elements and to maintain the same operational performance of each piezoelectric element. The present invention is applied to a method for manufacturing a head gimbal assembly for controlling the position of a head slider by a two-stage actuator system, a method for manufacturing a flexure constituting the head gimbal assembly, and a flexure sheet used for manufacturing the head gimbal assembly and the flexure. Can do.

  DESCRIPTION OF SYMBOLS 1 ... HGA, 2 ... Base plate, 3 ... Load beam, 4 ... Flexure board | substrate, 5 ... Base insulation layer, 6 ... Flexure, 11 ... Connection wiring, 12a, 12b ... Piezoelectric element part, 13, 15 ... Cover insulation layer, 14 ... PZT element, 17a, 17b ... electrode layer, 25 ... protective insulating layer, 50 ... suspension, 60 ... head slider, 70 ... metal sheet, 70a ... outer frame, 70b ... connecting portion, 71 ... base area, 71a ... baseline 72 ... Unnecessary region 73 ... Base insulating layer 80 ... Base sheet 90 ... Flexure sheet

Claims (12)

A method of manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed, and a suspension for supporting the head slider,
In a flexure manufacturing process for manufacturing a flexure to which the head slider is mounted, a piezoelectric element and an upper side and a lower side of the piezoelectric element are respectively formed on the surface of a base insulating layer formed on a flexure substrate serving as a base of the flexure. A piezoelectric element having an upper insulating layer and a lower insulating layer formed on each other, and the upper insulating layer and the lower insulating layer fixing a pair of piezoelectric element portions having a common structure with common materials and dimensions Manufactured flexure with
A suspension manufacturing process for manufacturing the suspension by bonding the flexure with a piezoelectric element to a load beam and a base plate;
And a slider mounting step of mounting the head slider on the suspension. A method of manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed, and a suspension for supporting the head slider,
In a flexure manufacturing process for manufacturing a flexure to which the head slider is mounted, the base in a base area surrounded by a base line indicating the outer shape of the flexure is obtained for a base sheet having a base insulating layer formed on at least one surface. The surface of the insulating layer has a piezoelectric element, and an upper insulating layer and a lower insulating layer formed on the upper and lower sides of the piezoelectric element, respectively, and the upper insulating layer and the lower insulating layer are made of a material and A flexure sheet manufacturing process for manufacturing a flexure sheet with a piezoelectric element by fixing a pair of piezoelectric element portions having a common structure with common dimensions;
A cutting step of manufacturing a flexure with a piezoelectric element by cutting out the base area from the flexure sheet;
A suspension manufacturing process for manufacturing the suspension by bonding the flexure with a piezoelectric element to a load beam and a base plate;
And a slider mounting step of mounting the head slider on the suspension. In the flexure sheet manufacturing process, a multi-base sheet in which a plurality of the base areas are formed is used as the base sheet, and the multi-base sheet has the pair of piezoelectric elements on the surface of the base insulating layer in each of the base areas. By fixing the part, the flexure sheet is manufactured,
In the cutting step, a plurality of flexures with piezoelectric elements are manufactured by cutting each base area from the flexure sheet,
In the suspension manufacturing step, a plurality of the suspensions are manufactured by joining each of the flexures with piezoelectric elements to the load beam and the base plate.
3. The method of manufacturing a head gimbal assembly according to claim 2, wherein in the slider mounting step, the head slider is mounted on each suspension. In the flexure manufacturing process, a metal sheet having the base area formed so as to be connected to the outer frame is formed inside the outer frame, and the base insulating layer is formed on at least one surface of the metal sheet. And further comprising a base sheet manufacturing process for manufacturing the base sheet,
4. The method of manufacturing a head gimbal assembly according to claim 2, wherein the flexure sheet manufacturing process manufactures the flexure sheet using the base sheet manufactured by the base sheet manufacturing process. The flexure manufacturing process includes a wiring forming process for forming connection wirings connected to the pair of piezoelectric element portions or the head slider on the surface of the base insulating layer, and protective insulation for forming a protective insulating layer covering the connection wirings. A layer forming step,
5. The method for manufacturing a head gimbal assembly according to claim 1, wherein in the protective insulating layer forming step, the protective insulating layer is formed so as to cover the pair of piezoelectric element portions together with the connection wiring. A flexure manufacturing method used for manufacturing a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension for supporting the head slider,
For a base sheet having a base insulating layer formed on at least one surface, a piezoelectric element and an upper side of the piezoelectric element are respectively formed on the surface of the base insulating layer in a base area surrounded by a base line indicating the outer shape of the flexure. And an upper insulating layer and a lower insulating layer formed respectively on the lower side, and the upper insulating layer and the lower insulating layer fix a pair of piezoelectric element portions having a common structure with common materials and dimensions. A flexure sheet manufacturing process for manufacturing a flexure sheet with a piezoelectric element,
A flexure manufacturing method comprising: a cutting step of manufacturing a flexure with a piezoelectric element by cutting out the base area from the flexure sheet. In the flexure sheet manufacturing process, a multi-base sheet in which a plurality of the base areas are formed is used as the base sheet, and the multi-base sheet has the pair of piezoelectric elements on the surface of the base insulating layer in each of the base areas. By fixing the part, the flexure sheet is manufactured,
The flexure manufacturing method according to claim 6, wherein, in the cutting step, a plurality of flexures with piezoelectric elements are manufactured by cutting each base area from the flexure sheet. A metal sheet having the base area formed so as to be connected to the outer frame is formed inside the outer frame, and the base insulating layer is formed on at least one surface of the metal sheet to thereby form the base. It further has a base sheet manufacturing process for manufacturing a sheet,
The said flexure sheet manufacturing process is a manufacturing method of the flexure of Claim 6 or 7 which manufactures the said flexure sheet using the said base sheet manufactured by this base sheet manufacturing process. A head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension for supporting the head slider,
The suspension has a flexure in which a base insulating layer is formed on at least one surface of a flexure substrate;
The flexure has a structure with a piezoelectric element in which a pair of piezoelectric element portions each having a piezoelectric element are fixed on the base insulating layer, and connection wiring connected to the pair of piezoelectric element portions or the head slider And a protective insulating layer formed on the surface of the base insulating layer so as to cover the connection wiring and the pair of piezoelectric element portions, and the pair of piezoelectric element portions are incorporated in the inside together with the connection wiring. Having a structure
Each of the piezoelectric element portions has an upper insulating layer and a lower insulating layer on the upper and lower sides of the piezoelectric element, respectively, and the upper insulating layer and the lower insulating layer have a common structure in which the material and dimensions are common. Head gimbal assembly having. A flexure sheet used for manufacturing a flexure constituting a head gimbal assembly having a head slider on which a thin film magnetic head is formed and a suspension for supporting the head slider,
A rectangular base sheet made of a metal material having a base insulating layer formed on at least one surface has a plurality of base areas surrounded by a base line indicating the outer shape of the flexure, and the base in each base area The surface of the insulating layer has a piezoelectric element, and an upper insulating layer and a lower insulating layer formed on the upper and lower sides of the piezoelectric element, respectively, and the upper insulating layer and the lower insulating layer are made of a material and A flexure sheet to which a pair of piezoelectric element portions having a common structure with common dimensions are fixed. The base sheet is inside the outer frame, according to claim wherein the base insulating layer is formed in a plurality of said at least one surface of a metal sheet in which the base area is formed to be connected to the external frame The flexure sheet according to 10 . Connection wires connected to the pair of piezoelectric element portions or the head slider are formed on the surface of the base insulating layer,
The flexure sheet according to claim 10 or 11 , further comprising a protective insulating layer formed so as to cover the pair of piezoelectric element portions together with the connection wiring.