JP6241705B2 - Suspension substrate, suspension, suspension with head, hard disk drive, and method for manufacturing suspension substrate - Google Patents

Description

  The present invention relates to a suspension substrate, a suspension, a suspension with a head, a hard disk drive, and a method for manufacturing a suspension substrate. The present invention relates to a suspension substrate, a suspension, a suspension with a head, a hard disk drive, and a method for manufacturing a suspension substrate capable of suppressing a decrease.

  Generally, a hard disk drive (HDD) includes a suspension substrate (flexure) on which a magnetic head slider for writing and reading data to and from a disk storing data is mounted. The suspension substrate is formed to extend from a head region on which the magnetic head slider is mounted to a tail region connected to an FPC substrate (flexible printed circuit board), and a metal support layer and an insulating layer on the metal support layer And a wiring layer having a plurality of wirings stacked via each other, and by writing an electric signal through each wiring, data is written to or read from the disk.

  In such a hard disk drive, in order to move the magnetic head slider to a desired data track on the disk, a VCM actuator (voice coil motor) that rotates an actuator arm that supports the magnetic head slider is provided by a servo control system. I have control.

  In recent years, there has been an increasing demand for an increase in disk capacity. In order to meet this demand, the density of the disk is increased and the width of the track is reduced. For this reason, it may be difficult to accurately align the magnetic head slider to a desired track by the VCM actuator.

  In order to cope with this, a dual actuator type suspension is known in which a VCM actuator and a PZT microactuator (Dual Stage Actuator: DSA) cooperate to move a magnetic head slider to a desired track (for example, , See Patent Document 1). This PZT microactuator is composed of a piezo element (piezoelectric element) made of PZT (lead zirconate titanate), and expands and contracts when a voltage is applied to move the magnetic head slider minutely. In such a dual actuator type suspension, the VCM actuator roughly adjusts the position of the magnetic head slider, and the PZT microactuator finely adjusts the position of the magnetic head slider. In this way, the magnetic head slider is aligned with a desired track quickly and accurately.

  In Patent Document 1, a piezo element is mounted on a head region of a suspension substrate. In this case, since the piezo element can be disposed close to the head slider, it is possible to improve the accuracy of alignment of the head slider. In Patent Document 1, a housing opening for housing the piezoelectric element is provided in the metal support layer, and the piezoelectric element is arranged in a portion of the insulating layer exposed to the housing opening. In addition, a terminal opening is provided in the insulating layer, and an element connection terminal that is electrically connected to the piezo element is provided in the terminal opening.

JP 2012-99204 A

  However, in Patent Document 1, the lower surface of the element connection terminal provided in the terminal opening is formed on the same plane as the lower surface of the insulating layer. As a result, there is a problem that it is difficult to improve the reliability of electrical connection between the piezoelectric element and the element connection terminal. For example, when a piezo element and an element connection terminal are electrically connected using a solder ball, the solder ball is likely to be displaced from the element connection terminal. In this case, it may be difficult to electrically connect the actuator element and the element connection terminal with a solder material. Further, in the case of using the solder paste, there is a problem that the solder paste spreads from the element connection terminal to the surroundings. Even in this case, the actuator element and the element connection terminal may be electrically connected by the solder material. Can be difficult.

  In addition, when the piezo element and the element connection terminal are electrically connected by a solder material, there is a problem that the reliability of the actuator element can be lowered. That is, when the solder material is welded to the electrode of the actuator element, the solder material is heated. At this time, the actuator element may be thermally damaged.

  The present invention has been made in view of the above points, and the suspension substrate is capable of improving the reliability of the electrical connection with the mounted actuator element and suppressing the decrease in the reliability of the actuator element. An object of the present invention is to provide a method for manufacturing a suspension, a suspension with a head, a hard disk drive, and a suspension substrate.

  The present invention provides a suspension substrate having a head region on which a head slider and a telescopic actuator element that displaces the head slider are mounted, a metal support layer, an insulating layer provided on the metal support layer, A wiring layer provided on the insulating layer and having an element connection terminal, and in the head region, the metal support layer is provided with an accommodating opening for accommodating the actuator element, and the insulating layer is provided with: A terminal opening that exposes the element connection terminal to the accommodation opening is provided, and a conductive layer that connects the actuator element and the element connection terminal is provided in the terminal opening, and the conductive layer includes the element Solder layer provided on the surface of the connection terminal on the insulating layer side, and conductive adhesive provided on the surface of the solder layer on the side opposite to the element connection terminal side If, to provide a substrate for suspension, characterized in that a.

  In the suspension substrate described above, a part of the conductive adhesive layer may be formed in the terminal opening.

  In the suspension substrate described above, the conductive adhesive layer may protrude from the terminal opening toward the housing opening.

  In the suspension substrate described above, the surface of the solder layer on the conductive adhesive layer side may be disposed on the same plane as the surface of the insulating layer on the metal support layer side. Good.

  In the suspension substrate described above, the conductive adhesive layer may be formed on a part of the surface of the solder layer on the conductive adhesive layer side.

  The present invention includes a base plate, the above-described suspension substrate attached to the base plate via a load beam, and the actuator element mounted on the head region of the suspension substrate. To provide a suspension.

  The present invention provides a suspension with a head comprising the above-described suspension and a head slider mounted on the head region of the suspension substrate.

  The present invention provides a hard disk drive including the above-described suspension with a head.

  The present invention relates to a method for manufacturing a suspension substrate having a head region on which a head slider and a telescopic actuator element that displaces the head slider are mounted, and is provided on the metal support layer and the metal support layer. A substrate material body including an insulating layer and a wiring layer provided on the insulating layer and having an element connection terminal, wherein the actuator element is accommodated in the metal support layer in a region forming the head region. And a step of preparing a substrate material body provided with a terminal opening that exposes the element connection terminal to the accommodation opening, and the insulating layer is mounted in the terminal opening. Forming a conductive layer that connects the actuator element and the element connection terminal, wherein the step of forming the conductive layer includes the element connection terminal. Forming a solder layer on the surface on the insulating layer side, and forming a conductive adhesive layer on the surface of the solder layer opposite to the element connection terminal side. A suspension substrate manufacturing method is provided.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the reliability of the electrical connection with the actuator element mounted, the reliability fall of an actuator element can be suppressed.

FIG. 1 is a plan view showing an example of a suspension with a head according to an embodiment of the present invention. FIG. 2 is an enlarged plan view showing a head region in the suspension with a head shown in FIG. FIG. 3 is a partial cross-sectional view showing the head region of FIG. 4 is a partially enlarged cross-sectional view of FIG. FIG. 5 is a perspective view showing an example of a hard disk drive including the suspension with a head shown in FIG. 6 (a) to 6 (c) are diagrams illustrating a method for manufacturing a suspension substrate according to an embodiment of the present invention. 7A and 7B are views for explaining a method of mounting a piezoelectric element on the suspension substrate shown in FIG. FIG. 8 is a cross-sectional view showing a modification of FIG.

  A manufacturing method of a suspension substrate, a suspension, a suspension with a head, a hard disk drive, and a suspension substrate according to an embodiment of the present invention will be described with reference to FIGS. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones.

  As shown in FIG. 1, the suspension with head 111 includes a suspension 101 and a head slider 112 mounted on the head region 2 of the suspension substrate 1. Of these, the head slider 112 is for writing and reading data on a disk 123 (see FIG. 5) described later, and is bonded to the head region 2 of the suspension substrate 1 described later using an adhesive. ing. A slider terminal (not shown) of the head slider 112 is electrically connected to the head terminal 41 by a solder material.

  The suspension 101 includes a base plate 102, a load beam 103 attached on the base plate 102, a suspension substrate 1 attached to the load beam 103, and a pair of piezo elements (mounted on the head region 2 of the suspension substrate 1). Actuator element) 104. Of these, the base plate 102 and the load beam 103 are both preferably made of stainless steel and are fixed to each other by welding.

  The load beam 103 is attached to the metal support layer 20 (described later) of the suspension substrate 1 by welding. The load beam 103 is provided with a jig hole (not shown), and the suspension substrate 1 is aligned with the jig hole of the load beam 103 as shown in FIG. A jig hole 5 for performing the above is provided. Thus, when the load beam 103 is attached to the suspension substrate 1, the suspension substrate 1 and the load beam 103 can be aligned. The jig hole of the load beam 103 and the jig hole 5 of the suspension substrate 1 are arranged on the longitudinal axis (X) shown in FIG.

  As shown in FIGS. 1 and 2, the piezo element 104 is configured to be stretchable in the longitudinal direction (P direction in FIG. 2). As a result, the pair of piezo elements 104 can displace the head slider 112 in the sway direction (the turning direction, the arrow Q direction in FIG. 2). Further, as shown in FIG. 3, each piezo element 104 includes a pair of electrodes (first electrode 104a, second electrode 104b) and a piezoelectric material portion 104c made of piezoelectric ceramics such as PZT (lead zirconate titanate). And have. The pair of electrodes 104a and 104b is formed at both ends (first element end 104d and second element end 104e) of the piezoelectric material portion 104c in the expansion / contraction direction on the surface of the piezoelectric material portion 104c on the insulating layer 10 side. Has been. That is, the piezo element 104 has a first element end 104d and a second element end 104e as ends in the expansion / contraction direction, the first electrode 104a is formed on the first element end 104d, A second electrode 104b is formed on the two-element end portion 104e.

  As shown in FIGS. 2 and 3, the first electrode 104a of the piezo element 104 is connected to a first element connection terminal 45 (described later) of the suspension substrate 1 via a first conductive layer 71 described later. . The first element connection terminal 45 is connected to the metal support layer 20 through a conductive connection portion 60 (described later) and is electrically grounded. The second electrode 104b is electrically connected to a second element connection terminal 46 (described later) of the suspension substrate 1 via a second conductive layer 72 described later. The second element connection terminal 46 is connected to an element wiring 44 which will be described later, and a predetermined voltage is applied to the second element connection terminal 46 in order to expand and contract the piezo element 104.

  As shown in FIG. 3, a non-conductive adhesive (for example, UV curable resin) 106 is applied to each of the element end portions 104d and 104e. The non-conductive adhesive 106 is for mechanically joining the piezo element 104 to the suspension substrate 1.

  The piezoelectric material portions 104c of the pair of piezo elements 104 are formed to have polarization directions different from each other by 180 °. When a predetermined voltage is applied, one piezo element 104 contracts and the other piezo element 104 104 extends. That is, the piezoelectric element 104 is configured as a piezoelectric element that can expand and contract in the direction of arrow P in FIG. 2 when a predetermined voltage is applied between the electrodes 104a and 104b.

  As shown in FIG. 1, such a piezo element 104 is formed in an elongated rectangular shape along the longitudinal axis (X), and its expansion / contraction direction is parallel to the longitudinal axis (X). ing. The piezo elements 104 are arranged symmetrically with respect to the longitudinal axis (X) so that the expansion and contraction of each piezo element 104 is evenly transmitted to the head slider 112.

  Next, the suspension substrate 1 will be described.

  As shown in FIG. 1, the suspension substrate 1 includes a head region (gimbal region) 2 on which the head slider 112 and the piezoelectric element 104 are mounted, and a tail region 3 to which an FPC substrate (external connection substrate) 131 is connected. ,have. The head region 2 is provided with a plurality of head terminals 41 connected to the head slider 112, and the tail region 3 is provided with a plurality of tail terminals (external connection substrate terminals) 42 connected to the FPC board 131. Yes. The head terminal 41 and the tail terminal 42 are respectively connected by a plurality of signal wirings 43 described later.

  As shown in FIGS. 1 to 3, the suspension substrate 1 includes a metal support layer 20, an insulating layer 10 provided on the metal support layer 20, and a plurality of wirings 43 and 44 provided on the insulating layer 10. And a wiring layer 40 having. That is, the wiring layer 40 is laminated on the metal support layer 20 via the insulating layer 10. A protective layer 50 that covers the wirings 43 and 44 is provided on the insulating layer 10. The head slider 112 described above is disposed on the protective layer 50 side (on the protective layer 50) of the suspension substrate 1, and the piezo element 104 is disposed on the metal support layer 20 side. In FIGS. 1 and 2, the protective layer 50 is omitted for the sake of clarity.

  As shown in FIGS. 2 to 4, the metal support layer 20 includes a metal support layer main body 21 and a tongue portion 22 that is disposed in the head region 2 and to which the head slider 112 is attached. The metal support layer main body 21 and the tongue portion 22 are connected by a central connecting portion 24 that extends along the longitudinal axis (X). The width of the central connecting portion 24 is reduced, whereby the central connecting portion 24 has flexibility, prevents the pivot movement of the head slider 112 from being inhibited, and prevents the piezoelectric element 104 from expanding and contracting. Is prevented.

  In the head region 2, a rectangular accommodation opening 25 that accommodates the piezoelectric element 104 is provided in the metal support layer 20. The accommodation opening 25 is disposed on both sides of the central coupling portion 24. That is, the central connecting portion 24 is disposed between the pair of accommodation openings 25. In the present embodiment, the member constituting the metal support layer 20 is not formed on the outer side of the accommodation opening 25 (the side opposite to the side of the central coupling portion 24). However, if there is no problem in the expansion / contraction operation of the piezo element 104, a member constituting the metal support layer 20 may be formed outside the accommodation opening 25.

  The wiring layer 40 includes a plurality of wirings, that is, a signal wiring 43 including a pair of reading wirings and a pair of writing wirings, and a pair of element wirings 44 connected to the piezoelectric element 104. Among these, the signal wiring 43 connects the head terminal 41 and the tail terminal 42, and an electric signal is passed through the signal wiring 43, so that the head slider 112 receives data from the disk 123 (see FIG. 6). Write or read. The element wiring 44 extending from the tail terminal 42 is connected to the second element connection terminal 46, and applies a predetermined voltage to the second electrode 104 b of the piezo element 104.

  The wiring layer 40 includes a first element connection terminal 45 connected to the first electrode 104a of the piezo element 104 and a second element connection terminal 46 connected to the second electrode 104b of the piezo element 104. . Among these, the first element connection terminal 45 is for grounding the first electrode 104a of the piezo element 104 and grounding the piezo element 104, and the metal support layer is connected via a conductive connection portion 60 described later. It is electrically connected to 20 tongue portions 22. As described above, the second element connection terminal 46 is for applying a predetermined voltage to the second electrode 104b of the piezo element 104, and the element wiring 44 is connected to the second element connection terminal 46. Yes.

  As shown in FIG. 3, a terminal opening 11 is provided in the insulating layer 10 to expose the element connection terminals 45 and 46 to the piezoelectric element 104 side. A plating layer (not shown) formed by applying nickel (Ni) plating and gold (Au) plating in this order is provided on a portion of the element connection terminals 45 and 46 exposed to the terminal opening 11. Yes. This prevents the element connection terminals 45 and 46 from corroding and reduces the connection resistance between the electrodes 104 a and 104 b of the piezoelectric element 104 and the element connection terminals 45 and 46. The head terminal 41 and the tail terminal 42 are similarly provided with plating layers.

  As shown in FIGS. 3 and 4, the terminal openings 11 have conductive layers (first conductive layer 71 and second conductive layer 72) that electrically connect the piezoelectric element 104 and the element connection terminals 45 and 46. Is provided. Among these, the first conductive layer 71 is provided in the terminal opening 11 corresponding to the first element connection terminal 45, and the second conductive layer 72 is the terminal opening 11 corresponding to the second element connection terminal 46. Is provided inside. In FIG. 4 (the same applies to FIGS. 6 to 8 described later), the first conductive layer 71 is shown, but the second conductive layer 72 can have the same configuration as the first conductive layer 71. Therefore, a partial enlarged cross-sectional view showing the second conductive layer 72 is omitted.

  As shown in FIG. 4, the conductive layers 71 and 72 include a solder layer 73 provided on the surface of the element connection terminals 45 and 46 on the insulating layer 10 side, and the element connection terminals 45 and 46 side of the solder layer 73. Has a conductive adhesive layer 74 provided on the opposite surface (the surface on the piezoelectric element 104 side). Among these, the conductive adhesive layer 74 is formed of a conductive adhesive such as a silver paste (a paste in which a binder such as an epoxy resin and a silver filler are mixed). The conductive adhesive layer 74 is connected to the electrodes 104 a and 104 b of the piezo element 104. In this way, the electrodes 104 a and 104 b of the piezoelectric element 104 and the element connection terminals 45 and 46 are electrically connected through the solder layer 73 and the conductive adhesive layer 74. Note that the conductive adhesive layer 74 is preferably provided on the entire surface of the solder layer 73 on the side of the conductive adhesive layer 74 (the surface on the side of the piezoelectric element 104). Further, it is preferable that the conductive adhesive layer 74 protrudes so as to rise from the terminal opening 11 to the housing opening 25 side (piezo element 104 side).

  As shown in FIG. 4, a part of the conductive adhesive layer 74 is formed in the terminal opening 11. That is, the surface of the solder layer 73 on the piezo element 104 side is arranged on the upper side (element connection terminals 45 and 46 side) of the surface of the insulating layer 10 on the metal support layer 20 side.

  Such conductive layers 71 and 72 including the solder layer 73 and the conductive adhesive layer 74 are handled as members constituting the suspension substrate 1 in the present embodiment.

  As described above, the first element connection terminal 45 is electrically connected to the tongue portion 22 of the metal support layer 20 by the conductive connection portion (via) 60. That is, the insulating layer through hole 12 is provided in the insulating layer 10, and the wiring layer through hole 48 is provided in the wiring layer 40, and nickel plating or copper plating is applied to the insulating layer through hole 12 and the wiring layer through hole 48. As a result, the conductive connection portion 60 is formed. In this way, the first element connection terminal 45 is grounded. In the form shown in FIG. 3, the conductive connection portion 60 is covered with a protective layer 50 to prevent corrosion of the conductive connection portion 60.

  Next, materials constituting each layer of the suspension substrate 1 will be described in detail.

  The material of the insulating layer 10 is not particularly limited as long as it is a material having a desired insulating property. For example, it is preferable to use polyimide (PI). Note that the material of the insulating layer 10 can be a photosensitive material or a non-photosensitive material. Moreover, it is preferable that the thickness of the insulating layer 10 is 5 micrometers-10 micrometers. As a result, the insulation performance between the metal support layer 20 and the wirings 43 and 44 can be ensured, and loss of the rigidity of the suspension substrate 1 as a whole can be prevented.

  The wirings 43 and 44 of the wiring layer 40 are configured as conductors for transmitting electrical signals, and the materials of the wirings 43 and 44 are particularly limited as long as they have a desired conductivity. However, it is preferable to use copper (Cu). In addition to copper, any material having electrical characteristics similar to pure copper can be used. Here, it is preferable that the thickness of each wiring 43 and 44 is 5 micrometers-18 micrometers. As a result, it is possible to ensure the transmission characteristics of the wirings 43 and 44 and to prevent the flexibility of the suspension substrate 1 as a whole from being lost. The head terminal 41, the tail terminal 42, and the element connection terminals 45 and 46 have the same material and the same thickness as the wirings 43 and 44, and constitute the wiring layer 40.

  The material of the metal support layer 20 is not particularly limited as long as it has desired conductivity, elasticity, and strength. For example, stainless steel, 42 alloy, aluminum, beryllium copper, or other copper Alloys can be used, and among these, stainless steel is preferred. The thickness of the metal support layer 20 is preferably 15 μm to 20 μm. As a result, the conductivity, rigidity, and elasticity of the metal support layer 20 can be ensured.

  As a material of the protective layer 50, it is preferable to use a resin material, for example, polyimide. The material of the protective layer 50 can be a photosensitive material or a non-photosensitive material. The thickness of the protective layer 50 is preferably 3 μm to 10 μm on the wirings 43 and 44.

  Next, the hard disk drive 121 in the present embodiment will be described with reference to FIG. The hard disk drive 121 shown in FIG. 5 has a case 122, a disk 123 that is rotatably attached to the case 122 and stores data, a spindle motor 124 that rotates the disk 123, and a desired flying height on the disk 123. And a suspension 111 with a head including a head slider 112 that writes and reads data to and from the disk 123. Of these, the suspension with head 111 is movably attached to the case 122, and a voice coil motor 125 that moves the head slider 112 of the suspension with head 111 along the disk 123 is attached to the case 122. Yes. The suspension with head 111 is attached to the voice coil motor 125 via an arm 126, and is connected to an FPC board 131 (see FIG. 1) connected to a control unit (not shown) that controls the hard disk drive 121. ing. In this way, an electrical signal is transmitted between the control unit and the head slider 112 via the suspension board 1 and the FPC board 131.

  Next, a method for manufacturing the suspension substrate 1 according to the present embodiment will be described with reference to FIG.

  First, a substrate material body 1a is prepared (see FIG. 6A). Here, the substrate material body 1a is a substrate for producing the suspension substrate 1 including the conductive layers 71 and 72 in the present embodiment. As shown in FIG. It means a substrate at a stage before 72 is formed. Here, the case where the board | substrate material body 1a is manufactured by a subtractive method as an example is demonstrated.

  First, a laminate (not shown) in which the metal support layer 20, the insulating layer 10, and the wiring layer 40 are laminated is prepared. Subsequently, the wiring layer 40 is etched into a desired shape, so that the head terminal 41, the tail terminal 42, the wirings 43 and 44, and the element connection terminals 45 and 46 are formed. Next, the protective layer 50 covering the wirings 43 and 44 is formed on the insulating layer 10 in a desired shape. Subsequently, the insulating layer 10 is etched into a desired shape. At this time, a terminal opening 11 is formed in the insulating layer 10 in a region forming the head region 2. Thereafter, the metal support layer 20 is etched into a desired shape and is subjected to outer shape processing. In the region forming the head region 2, the tongue portion 22 and the accommodation opening portion 25 are formed in the metal support layer 20. In this way, the substrate material body 1a is obtained.

  After the substrate material body 1a is prepared, conductive layers 71 and 72 for connecting the piezoelectric element 104 and the element connection terminals 45 and 46 are formed.

  In this case, first, the solder layer 73 is formed on the surface exposed to the terminal opening 11 of the element connection terminals 45 and 46 (see FIG. 6B).

  The method for forming the solder layer 73 is not particularly limited. For example, a solder ball is supplied into the terminal opening 11 and the solder ball is irradiated with laser light to heat the solder ball. The solder layer 73 melted and welded to the element connection terminals 45 and 46 can be obtained. Note that when the solder ball is melted, the solder ball is preferably heated to 300 ° C. or higher.

  Further, as a method for forming the solder layer 73, the solder layer 73 can be formed by, for example, a printing method in addition to the method using a solder ball. In this case, a solder layer 73 welded to the element connection terminals 45 and 46 can be obtained by applying a solder paste (also referred to as cream solder) in the terminal opening 11 and heating and melting it. Here, the solder paste is a paste in which fine powdery solder particles are formed by a flux. For this reason, when heated after printing, the solder grains are melted, and a solder layer 73 welded to the exposed surfaces of the element connection terminals 45 and 46 is formed. Further, the solder jet method can be used to supply molten solder into the terminal opening 11 to obtain the solder layer 73 welded to the element connection terminals 45 and 46, or to obtain the solder layer 73 by plating. You can also.

  After the solder layer 73 is formed, a conductive adhesive layer 74 is formed on the surface of the solder layer 73 opposite to the element connection terminals 45 and 46 (see FIG. 6C). In this case, first, a conductive adhesive is applied onto the solder layer 73 by a printing method. At this time, the conductive adhesive to be applied is preferably applied so as to rise from the terminal opening 11.

  In this manner, the suspension substrate 1 in which the conductive layers 71 and 72 including the solder layer 73 and the conductive adhesive layer 74 are provided in the terminal opening 11 according to the present embodiment is obtained.

  Next, a method for manufacturing the suspension 101 using the suspension substrate 1 obtained as described above will be described with reference to FIG.

  First, the above-described suspension substrate 1 is attached to the base plate 102 (see FIG. 1) via the load beam 103 by welding. In this case, first, the load beam 103 is fixed to the base plate 102 by welding, then, a jig hole (not shown) provided in the load beam 103 and a jig hole 5 provided in the suspension substrate 1. Thus, alignment of the load beam 103 and the suspension substrate 1 is performed. Thereafter, the metal support layer 20 of the suspension substrate 1 is welded, and the load beam 103 and the suspension substrate 1 are joined and fixed to each other.

  Next, the piezo element 104 is mounted on the head region 2 of the suspension substrate 1 (see FIG. 7A). In this case, first, the piezo element 104 is accommodated in the accommodation opening 25. As a result, the electrodes 104 a and 104 b of the piezoelectric element 104 are electrically connected to the conductive adhesive layer 74 of the conductive layers 71 and 72.

  Thereafter, the conductive adhesive of the conductive adhesive layer 74 is baked and cured. Note that the baking treatment is preferably performed at 200 ° C. for a predetermined time.

  After the conductive adhesive is cured, the non-conductive adhesive 106 is applied to both ends of the piezo element 104 (potting). Thereafter, the applied non-conductive adhesive 106 is left in an air environment to be cured (see FIG. 7B). As a result, the piezo element 104 is mechanically bonded to the suspension substrate 1, and the piezo element 104 is mounted on the head region 2.

  In this way, the piezo element 104 is mounted on the suspension substrate 1, and the suspension 101 according to the present embodiment is obtained.

  Thereafter, the head slider 112 is mounted on the obtained suspension 101, and the suspension with head 111 according to the present embodiment is obtained.

  Further, the suspension with head 111 is attached to the arm 126 of the hard disk drive 121 and the FPC board 131 (see FIG. 1) is connected to the tail terminal 42 of the suspension board 1 to obtain the hard disk drive 121 shown in FIG. It is done.

  When writing and reading data in the hard disk drive 121 shown in FIG. 5, the disk 123 is rotated by the spindle motor 124, and the head slider 112 of the suspension with head 111 is moved along the disk 123 by the voice coil motor 125. At this time, the head slider 112 floats while maintaining a desired flying height on the disk 123 while performing a pivot motion together with the tongue 22 under the influence of the airflow generated by the rotation of the disk 123. In this state, data is exchanged between the head slider 112 and the disk 123. During this time, an electrical signal is transmitted between the head slider 112 and a control unit (not shown) connected to the FPC board 131 via the suspension board 1 and the FPC board 131. Such an electric signal is transmitted between the head terminal 41 (see FIG. 1) and the tail terminal 42 by each signal wiring 43 in the suspension board 1.

  When moving the head slider 112, the voice coil motor 125 roughly adjusts the position of the head slider 112, and the piezo element 104 finely adjusts the position of the head slider 112. That is, by applying a predetermined voltage to the second electrode 104b of the piezo element 104, one piezo element 104 contracts in the direction along the longitudinal axis (X) (the direction of arrow P in FIG. 2) and the other This piezo element 104 extends. In this case, a predetermined voltage is input to the piezoelectric element 104 via the element wiring 44, the second element connection terminal 46, and the second conductive layer 72.

  When the piezo element 104 expands and contracts, the head slider 112 mounted on the head region 2 moves in the sway direction (the arrow Q direction in FIG. 2). Thus, the head slider 112 can be accurately aligned with a desired track on the disk 123.

  As described above, according to the present embodiment, the conductive layers 71 and 72 that connect the piezoelectric element 104 to be mounted and the element connection terminals 45 and 46 are provided in the terminal opening. As a result, the conductive layers 71 and 72 can be locked to the terminal opening 11. Therefore, the conductive layers 71 and 72 can be prevented from being displaced from the element connection terminals 45 and 46, and the reliability of electrical connection between the piezo element 104 and the element connection terminals 45 and 46 can be improved.

  Further, according to the present embodiment, a part of the conductive adhesive layer 74 is formed in the terminal opening 11. As a result, the conductive adhesive layer 74 can be locked to the terminal opening 11. Therefore, the conductive layers 71 and 72 can be further prevented from being displaced from the element connection terminals 45 and 46, and the reliability of electrical connection between the piezoelectric element 104 and the element connection terminals 45 and 46 is further improved. be able to. In this case, when the conductive adhesive forming the conductive adhesive layer 74 is applied, the applied conductive adhesive reaches the metal support layer 20 by spreading around the terminal opening 11. Short-circuiting can be suppressed, and the reliability of electrical connection can be improved.

  In addition, according to the present embodiment, as described above, a part of the conductive adhesive layer 74 is formed in the terminal opening 11 so that the conductive adhesive layer from the terminal opening 11 is formed. The protrusion amount of 74 can be reduced. Therefore, the piezo element 104 can be mounted close to (or in close contact with) the insulating layer 10, and the mounting of the piezo element 104 can be stabilized.

  Further, according to the present embodiment, the solder layer 73 is interposed between the element connection terminals 45 and 46 and the conductive adhesive layer 74. Here, the conductive adhesive has a relatively large contact resistance with the plating layer formed on the element connection terminals 45 and 46. Therefore, by interposing the solder layer 73 between the plating layer and the conductive adhesive layer 74, the connection resistance between the piezo element 104 and the element connection terminals 45 and 46 can be reduced. The reliability of electrical connection with the element connection terminals 45 and 46 can be improved.

  Further, according to the present embodiment, the piezoelectric element 104 can be electrically connected to the element connection terminals 45 and 46 via the conductive layers 71 and 72 including the solder layer 73 and the conductive adhesive layer 74. it can. As a result, the amount of the relatively expensive conductive adhesive can be reduced, and the material cost of the suspension substrate 1 can be reduced. Moreover, the printing work of a conductive adhesive can be made easy by reducing the usage-amount of a conductive adhesive. In this case, the baking time after application of the conductive adhesive can be shortened, and thermal damage to the piezo element 104 can be suppressed.

  Further, according to the present embodiment, after the solder layer 73 is formed in the terminal opening 11, the conductive adhesive layer 74 is formed, and then the piezo element 104 is accommodated in the accommodation opening 25. In this case, the solder material for forming the solder layer 73 can be heated and melted before the piezoelectric element 104 is accommodated in the accommodation opening 25. That is, when the solder material is melted, the piezo element 104 can be prevented from being thermally damaged. As a result, it is possible to suppress a decrease in the reliability of the piezo element 104. Note that the piezoelectric element 104 can be heated when firing the conductive adhesive, but the temperature at which the conductive adhesive is fired is lower than the temperature at which the solder is melted. Thermal damage to the piezo element 104 can be reduced as compared with the case where the terminals 45 and 46 are connected by a solder material without using a conductive adhesive.

  Furthermore, according to the present embodiment, the conductive adhesive layer 74 protrudes from the terminal opening 11 toward the accommodation opening 25. Accordingly, the connection area between the conductive adhesive layer 74 and the electrodes 104a and 104b of the piezo element 104 can be increased, and the reliability of electrical connection can be improved.

  In the above-described embodiment, an example in which a part of the conductive adhesive layer 74 is disposed in the terminal opening 11 has been described. However, the present invention is not limited to this. For example, as shown in FIG. 8, the conductive adhesive layer 74 may be formed so as not to enter the terminal opening 11. That is, the surface of the solder layer 73 on the conductive adhesive layer 74 side may be arranged on the same plane as the surface of the insulating layer 10 on the metal support layer 20 side. In this case, the amount of the conductive adhesive used to form the conductive adhesive layer 74 can be further reduced. Therefore, the material cost can be further reduced, the printing workability of the conductive adhesive can be further improved, and the firing time can be further shortened. Here, the term “same” is not limited to the meaning of exactly the same, but is used as a meaning including a manufacturing error that can be regarded as the same.

  Moreover, in this Embodiment mentioned above, the conductive adhesive layer 74 demonstrated the example provided in the whole surface by the side of the conductive adhesive layer 74 of the solder layer 73. FIG. However, the present invention is not limited to this, and the conductive adhesive layer 74 may be formed on a part of the surface of the solder layer 73 on the conductive adhesive layer 74 side. In this case, the conductive adhesive layer 74 is formed on a part of the surface of the solder layer 73, and the other part of the surface is exposed. Thereby, the usage-amount of the conductive adhesive for forming the conductive adhesive layer 74 can be reduced further. Therefore, the material cost can be further reduced, the printing workability of the conductive adhesive can be further improved, and the firing time can be further shortened.

  Although the embodiments of the present invention have been described in detail above, the suspension substrate, suspension, suspension with head, hard disk drive, and suspension substrate manufacturing method according to the present invention are not limited to the above-described embodiments. Instead, various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Suspension board | substrate 2 Head area | region 10 Insulating layer 11 Terminal opening part 20 Metal support layer 25 Accommodating opening part 40 Wiring layer 45 1st element connection terminal 46 2nd element connection terminal 71 1st conductive layer 72 2nd conductive layer 73 Solder layer 74 Conductive adhesive layer 101 Suspension 102 Base plate 103 Load beam 104 Piezo element 111 Suspension with head 112 Head slider 121 Hard disk drive

Claims (9)

In a suspension substrate having a head region on which a head slider and a telescopic actuator element that displaces the head slider are mounted,
A metal support layer;
An insulating layer provided on the metal support layer;
A wiring layer provided on the insulating layer and having an element connection terminal;
In the head region, the metal support layer is provided with an accommodation opening for accommodating the actuator element,
The insulating layer is provided with a terminal opening that exposes the element connection terminal to the accommodation opening,
A conductive layer that connects the actuator element and the element connection terminal is provided in the terminal opening,
The conductive layer includes a solder layer provided on the surface of the element connection terminal on the insulating layer side, and a conductive adhesive layer provided on a surface of the solder layer opposite to the element connection terminal side; Have
A plating layer is provided on a portion of the element connection terminal exposed to the terminal opening,
The suspension substrate, wherein the solder layer of the conductive layer is connected to the element connection terminal through the plating layer.   The suspension substrate according to claim 1, wherein a part of the conductive adhesive layer is formed in the terminal opening.   The suspension substrate according to claim 1, wherein the conductive adhesive layer protrudes from the terminal opening toward the accommodation opening.   2. The suspension substrate according to claim 1, wherein a surface of the solder layer on the conductive adhesive layer side is disposed on the same plane as a surface of the insulating layer on the metal support layer side. .   The suspension substrate according to claim 1, wherein the conductive adhesive layer is formed on a part of a surface of the solder layer on the conductive adhesive layer side. A base plate;
The suspension substrate according to any one of claims 1 to 5, attached to the base plate via a load beam;
And the actuator element mounted on the head region of the suspension substrate. The suspension according to claim 6;
And a head slider mounted on the head region of the suspension substrate.   A hard disk drive comprising the suspension with a head according to claim 7. In a method for manufacturing a suspension substrate having a head region on which a head slider and a telescopic actuator element that displaces the head slider are mounted,
A substrate material body comprising a metal support layer, an insulating layer provided on the metal support layer, and a wiring layer provided on the insulating layer and having an element connection terminal, which forms the head region In the region, a substrate material body in which the metal support layer is provided with an accommodation opening for accommodating the actuator element, and the insulating layer is provided with a terminal opening for exposing the element connection terminal to the accommodation opening. The process of preparing
Forming a conductive layer in the terminal opening for connecting the actuator element to be mounted and the element connection terminal, and
The step of forming the conductive layer includes a step of forming a solder layer on the surface of the element connection terminal on the insulating layer side, and a step of forming the solder layer, and then the element connection terminal side of the solder layer. Forming a conductive adhesive layer on the opposite surface,
In the step of preparing the substrate material body, a plating layer is provided on a portion of the element connection terminal exposed to the terminal opening,
In the step of forming the conductive layer, the solder layer of the conductive layer is connected to the element connection terminal through the plating layer.

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