JP3835998B2 - Head support mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a head support mechanism provided in a disk device such as a magnetic disk used as a storage device of a computer, and more particularly to a head support mechanism suitable for increasing data recording density in a magnetic disk device.
[0002]
[Prior art]
The recording density of the magnetic disk provided in the magnetic disk device has been increasing. Accordingly, a head support mechanism that supports a magnetic head that records and reproduces data on a magnetic disk is required to be able to position the magnetic head with respect to the magnetic disk with higher accuracy.
[0003]
A conventional head support mechanism will be described with reference to FIG.
[0004]
Reference numeral 102 denotes a magnetic head that records and reproduces data on a magnetic disk (not shown) that is rotationally driven. The magnetic head 102 is supported on one end of the suspension arm 104. The other end of the suspension arm 104 is supported so as to be rotatable within a small angle range around the rotation center 108. The carriage 106 is supported so as to be rotatable with respect to a shaft member 110 fixed to the housing of the magnetic disk device.
[0005]
A permanent magnet (not shown) is fixed to the carriage 106. The carriage 106 is rotated with respect to the shaft member 110 by controlling an excitation current flowing in the drive coil 114 which is a part of the magnetic circuit 112 fixed to the housing side. Thereby, the magnetic head 102 is moved along the substantial radial direction of the magnetic disk.
[0006]
A pair of piezoelectric elements 116 </ b> A and 116 </ b> B is provided between the carriage 106 and the suspension arm 104. The two piezoelectric elements 116 </ b> A and 116 </ b> B are attached in a state where the longitudinal directions of the carriage 106 are slightly inclined in directions opposite to each other. Then, by applying voltages having opposite polarities to the two piezoelectric elements 116A and 116B, one piezoelectric element 116A (or 116B) is connected to A14.₁(Or A14₂) And the other piezoelectric element 116B (or 116A) at the same time as A14.₂ (Or A14₁The suspension arm 104 is rotated around the rotation center 108 by contracting along the direction of As a result, the magnetic head 102 attached to the tip of the suspension arm 104 is displaced in a minute range along the surface of the magnetic disk, and can be positioned with high accuracy at an arbitrary position on the magnetic disk.
[0007]
[Problems to be solved by the invention]
However, in the head support mechanism, not only the magnetic head 102 but also the suspension arm 104 to which the magnetic head 102 is attached are driven by the piezoelectric elements 116A and 116B, and the suspension arm 104 is attached to the magnetic head 102. It is considerably longer and has a larger mass.
[0008]
The magnetic head 102 and the suspension arm 104 are connected by ball bonding.
[0009]
Therefore, the moment of inertia of the suspension arm 104 is increased, and a large driving torque is required for the suspension arm 104 due to expansion and contraction of the piezoelectric elements 116A and 116B. Therefore, the magnetic head 102 cannot always respond with high speed and high accuracy to a command by voltage.
[0010]
For the above reasons, the head support mechanism cannot position the magnetic head 102 on the track on the disk with high speed response and high accuracy when controlling the minute displacement with respect to the magnetic head 102.
[0011]
Therefore, the present invention provides a head support mechanism for a disk device that can finely displace a magnetic head with high-speed responsiveness when controlling the minute displacement of the magnetic head for tracking correction or the like for the magnetic disk. Providing is a problem to be solved.
[0012]
Another object of the present invention is to provide a head support mechanism that sets the attitude of a slider with high accuracy with respect to a target value.
[0013]
[Means for Solving the Problems]
  According to a first aspect of the present invention, a head element is mounted, a slider having an electrode terminal electrically connected to the head element, a slider that supports the slider, and is connected to the electrode terminal to transmit a signal. A slider support portion having a head wiring terminal for communication, and the slider is supported by the slider support portion in a state where the electrode terminal and the head wiring terminal are in close contact with each other.The electrode terminal is disposed in the vicinity of the center portion of the slider on the supported surface of the slider, passes through the head element wiring on the back surface of the support surface of the slider support portion, and reaches the electrode terminal. A connection hole is opened, and the electrode terminal and the head wiring terminal are connected by ball bonding through the connection hole.It is characterized by this.
  As a result, the electrode terminal and the head wiring terminal are connected in close contact with each other. Therefore, when the slider and the slider support portion are connected vertically on the side surface of the slider as in the prior art, the slider support portion is fixed. Therefore, the weight of the head support mechanism can be reduced and the manufacturing cost can be reduced.
  In addition, since the load due to the electrode terminal and the head wiring terminal is applied to the center of the slider, the moment of inertia is reduced, and the slider can be made more stable.
  In addition, the electrode terminal and the head wiring terminal can be easily adhered and connected.
  Furthermore, since the electrode terminal and the head wiring terminal are connected via the connection hole, it is possible to prevent the displacement of the connection position.
[0014]
  The invention according to claim 2 of the present invention isA slider having a head element and having an electrode terminal electrically connected to the head element; and a slider support portion having a head wiring terminal that supports the slider and connects the electrode terminal to exchange signals. And the slider is supported by the slider support portion in a state where the electrode terminal and the head wiring terminal are in close contact with each other, and the electrode terminal is in the vicinity of the center portion of the slider on the supported surface of the slider The connection hole reaching the head wiring terminal is opened on the back surface of the support surface of the slider support portion, and the electrode terminal and the head wiring terminal are ultrasonically welded through the connection hole. ConnectingIt is characterized by this.
  ThisSince the electrode terminal and the head wiring terminal are connected in close contact, it is necessary to fix the slider support portion when the slider and the slider support portion are connected vertically on the side surface of the slider as in the prior art. Since the existing metal member becomes unnecessary, the head support mechanism can be reduced in weight and the manufacturing cost can be reduced.
  Also,Since the load due to the electrode terminal and the head wiring terminal is applied to the center of the slider, the moment of inertia is reduced and the slider can be made more stable.
  In addition, the electrode terminal and the head wiring terminal can be easily adhered and connected.
  Furthermore, since the electrode terminal and the head wiring terminal are connected via the connection hole, it is possible to prevent the displacement of the connection position.
[0021]
  Claims of the invention3The invention described in claim1Or claims2In the head support mechanism described in the above, the connection hole isBe providedThe slider support portion is made of polyimide.
[0022]
Thereby, since the polyimide which forms a slider support part is soft, the hole for a connection can be opened easily.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of a head support mechanism according to the present invention will be described in detail with reference to the drawings.
[0026]
FIG. 1 is a perspective view showing an entire head support mechanism according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view showing the head support mechanism.
[0027]
FIG. 3A is a perspective view of the slider in the head support mechanism, and FIG. 3B is a back view of the slider.
[0028]
4 is an exploded perspective view showing the structure of the flexure in the head support mechanism, FIG. 5 is a plan view of the thin film piezoelectric element unit in the head support mechanism, and FIG. 6 is an AA in FIG. It is sectional drawing in a line.
[0029]
7 is a plan view of the flexure as viewed from the side where the slider is attached, FIG. 8 is a cross-sectional view taken along line BB in FIG. 7, and FIG. 9 is a cross-sectional view taken along line CC in FIG. FIG.
[0030]
10 is a side view of the head support mechanism, FIG. 11 is a drive explanatory view of the thin film piezoelectric element unit in the head support mechanism, FIG. 12 is a drive explanatory view of the head support mechanism, and FIG. FIG. 14 is a diagram showing response characteristics when the head support mechanism is driven, FIG. 14 is a cross-sectional view when the slider is attached to the head support portion by ultrasonic welding, and FIG. 15 is a head support portion by ball bonding. It is sectional drawing at the time of attaching to.
[0031]
The head support mechanism 100 includes a base plate 10, a load beam 20, a flexure 30, a thin film piezoelectric element unit 40, a slider 50, and a head element 60.
[0032]
The base plate 10 is attached to a head actuator arm (not shown).
[0033]
The load beam 20 is for applying a predetermined load to the disk surface on which information is to be written. The load beam 20 is fixed to the base plate 10 and a neck extending from the base end 21. A portion 22, an opening 23 formed in a central region of the neck portion 22, a beam main portion 24 coupled to the neck portion 22, and a tip support portion 25 coupled to the tip of the beam main portion 24.
[0034]
Both side portions of the opening portion 23 in the neck portion 22 are configured as leaf spring portions 27a and 27b.
[0035]
The flexure 30 includes a flexure substrate 31, a slider support portion 32, and a wiring flexible substrate 33. On the wiring flexible substrate 33, a head element wiring 34 and a thin film piezoelectric element wiring 35 are patterned. The wiring flexible substrate 33 includes elastic hinge portions 33d and 33e and bifurcated piezoelectric support portions 33a and 33b.
[0036]
The flexure substrate 31 is made of metal, preferably stainless steel. The wiring flexible substrate 33 is made of an insulating film such as polyimide resin. On the wiring flexible substrate 33, the head element wiring 34 and the thin film piezoelectric element wiring 35 are patterned.
[0037]
The thin film piezoelectric element wiring 35 is configured such that the first thin film piezoelectric element driving wiring 35a, the second thin film piezoelectric element driving wiring 35b, the third thin film piezoelectric element driving wiring 35c, and the slider 50 are grounded. Ground wiring 35d for the purpose.
[0038]
The wiring flexible substrate 33 is connected to the main beam portion 24 of the load beam 20 except for the distal end thereof, and is connected to the base end portion 21 of the load beam 20 for external connection. The terminal holding part 33Y, the flexible substrate main part 33X, and the external connection terminal holding part 33Y have a crank connecting part 33Z that connects in a crank shape.
[0039]
The flexible substrate main portion 33X of the wiring flexible substrate 33 includes bifurcated piezoelectric support portions 33a and 33b, a slit 33c between the piezoelectric support portions 33a and 33b, and a distal end side of the piezoelectric support portions 33a and 33b. The elastic hinge portions 33d and 33e are locally formed with a narrow width with a constriction, and the slider holding portion 32 that connects the elastic hinge portions 33d and 33e at the distal ends is integrally formed. . The slit 33 c extends from the piezoelectric support portions 33 a and 33 b to the slider holding portion 32. The wiring flexible board 33 including the elastic hinge portions 33d and 33e is entirely made of polyimide resin or the like, and also serves as an insulating film for the head element wiring 34 and the thin film piezoelectric element wiring 35.
[0040]
In the slider 50, a head element 60 such as an MR element is mounted on a ceramic slider main body 51, and four electrode terminals 52 a, 52 b, 52 c, 52 d connected to the head element 60 are embedded in the slider main body 51. Some of them are arranged in a row and exposed on the slider supported surface.
[0041]
The upper surface of the slider body 51 is an air bearing surface 53 against an air flow generated by the magnetic disk that is driven to rotate. The air bearing surface 53 allows the air flow to flow along the pitching direction of the slider 50 (the tangential direction of the magnetic disk) to form an air lubricant film between the air bearing surface 53 and the magnetic disk.
[0042]
The head element wiring 34 of the wiring flexible substrate 33 includes a first head element wiring 34a and a second head element wiring 34b that are wired along the left side, and a third head wiring that is wired along the right side. There are a head element wiring 34c and a fourth head element wiring 34d. These wires extend to the slider support portion 32, where they form head wire terminals 34a ', 34b', 34c ', 34d', respectively. The head wiring terminals 34 a ′, 34 b ′, 34 c ′, 34 d ′ correspond to the electrode terminals 52 a, 52 b, 52 c, 52 d of the head provided on the surface opposite to the air bearing surface 53 of the slider 50.
[0043]
The wiring terminal 35c ′ of the third thin film piezoelectric element driving wiring 35c is disposed in the vicinity of the back end of the slit 33c, and the wiring terminal 35a ′ of the first thin film piezoelectric element driving wiring 35a and the second wiring terminal 35c ′ are arranged. The wiring terminals 35b 'of the thin film piezoelectric element driving wiring 35b are arranged on both the left and right sides of the wiring terminal 35c'.
[0044]
The ground wiring terminal 35d 'of the ground wiring 35d is disposed in the vicinity of the end on the tip end side of the slit 33c, and then connects to the wiring terminal 35c' of the third thin film piezoelectric element driving wiring 35c through both sides of the slit 33c. Has been. The ground wiring terminal 35 d ′ corresponds to the electrode terminal 52 e of the slider 50.
[0045]
The slider 50 is attached to the slider support part 32 of the flexure 30. The head wiring terminals 34a ', 34b', 34c ', 34d' and the ground wiring terminal 35d 'are bonded to the electrode terminals 52a, 52b, 52c, 52d, 52e.
[0046]
At this time, as shown in FIG. 14, through holes reaching the head wiring terminals 34a ', 34b', 34c ', 34d' are provided on the back surface of the slider support surface of the slider support portion 32. From the head wiring terminals 34a ', 34b', 34c ', 34d'. Using this through hole, the ultrasonic welding probe 62 is used to connect the ground wiring terminal 35d 'and the electrode terminals 52a, 52b, 52c, 52d, 52e to the head wiring terminals 34a', 34b ', 34c', 34d ', respectively. Connect by ultrasonic welding.
[0047]
Further, as shown in FIG. 15, as another method for connecting the head wiring terminals 34a ', 34b', 34c ', 34d' and the electrode terminals 52a, 52b, 52c, 52d, 52e of the slider 50, The wiring terminals 34a ', 34b', 34c ', 34d' are provided with a through hole having a diameter of about 0.05 mm at the center, from which the electrode terminals 52a, 52b, 52c, 52d, 52e of the slider 50 are provided. Appears. Using this through hole, each of the electrode terminals 52a, 52b, 52c, 52d, 52e of the slider 50 is connected to each of the head wiring terminals 34a ', 34b', 34c ', 34d' by the gold ball 61 by a ball bonder. You can also.
[0048]
The elastic hinge portion 33 d is composed of a ground wiring 35 d, a first head element wiring 34 a, a second head element wiring 34 b, and an insulating film of the flexible substrate 33. Similarly, the elastic hinge portion 33e is composed of the third head element wiring 34c, the fourth head element wiring 34d, and the insulating film of the flexible substrate 33. The movement of the thin film piezoelectric body is connected to the slider holding portion 32 via an elastic hinge.
[0049]
In the manufacture, the flexure 30 is molded on a stainless steel plate serving as a base of the flexure substrate 31 so as to cover the head element wiring 34 and the thin film piezoelectric element wiring 35. After the forming, a trimming process by etching is performed on the stainless steel plate to reveal the flexure substrate 31.
[0050]
The slider support portion 32 is flexible with respect to the flexure substrate 31 in the pitching direction and the rolling direction of the slider 50 via the elastic hinge portions 33 d and 33 e of the wiring flexible substrate 33. The pitching direction is the tangential direction of the recording track of the magnetic disk, and the rolling direction is the radial direction of the magnetic disk.
[0051]
A first head element wiring 34a and a second head element wiring 34b are wired at the outer edge of the piezoelectric support 33a, and a ground wiring 35d is wired at the inner edge. The first and second head element wirings 34a and 34b are each extended to the head support portion 32, where wiring terminals 34a 'and 34b' are formed, respectively. Further, the third head element wiring 34c and the fourth head element wiring 34d are wired at the outer edge of the piezoelectric support 33b, and the ground wiring 35d is wired at the inner edge. The third and fourth head element wirings 34c and 34d are each extended to the head support portion 32, where wiring terminals 34c 'and 34d' are formed, respectively.
[0052]
The thin film piezoelectric element unit 40 includes a first thin film piezoelectric element 40a and a second thin film piezoelectric element 40b which are bifurcated and connected only at the base, and both the first and second thin film piezoelectric elements. A slit 40c is formed between the elements 40a and 40b. The specific structure of the thin film piezoelectric element unit 40 will be described later.
[0053]
Thus, the individual description of each component of the base plate 10, the load beam 20, the flexure 30, the thin film piezoelectric element unit 40, the slider 50, and the head element 60 is completed.
[0054]
Next, the mutual relationship of each component will be described. The load beam 20 is integrally fixed to the base plate 10 at the base end portion 21 by beam welding or the like. The flexure 30 is integrally fixed to the load beam 20 through beam welding or an adhesive except for the tip side. The external connection terminal holding portion 33Y of the flexure 30 is fixed to the proximal end portion 21 of the load beam 20, the flexible substrate main portion 33X is fixed to the beam main portion 24 except for the distal end side, and the slider mounting portion 32 is supported at the distal end. It is placed on the part 25.
[0055]
At this time, the piezoelectric body support portions 33 a and 33 b of the flexure 30 are mounted in a non-bonded manner with respect to the beam main portion 24 of the load beam 20.
[0056]
The pair of left and right thin film piezoelectric elements 40a and 40b of the thin film piezoelectric element unit 40 are integrally bonded to the pair of left and right piezoelectric support portions 33a and 33b by adhesion. The wiring connection to the thin film piezoelectric element unit 40 will be described later.
[0057]
The terminals of the slider 50 equipped with the head element 60 are connected to the head wiring terminals 34a ′, 34b ′, 34c ′, 34d ′ and the ground wiring terminal 35d ′ of the slider support portion 32 by electrode terminals 52a, 52b, 52c, 52d, 52e. They are fixed integrally by ultrasonic welding or ball bonding, and are electrically connected.
[0058]
In the conventional head support mechanism, the center of rotation of the head element 60 is located considerably rearward in the longitudinal direction of the load beam 20, whereas in the embodiment of the present invention, the slider 50 including the head element 60 is The center of rotation is located in a state where the center of the load beam 20 is sufficiently shifted in the longitudinal direction.
[0059]
In comparison with FIG. 16, in the case of the conventional head support mechanism, the occupying length of the rotating element is in the range of L1 occupied by the suspension arm 104 and the head 102 on the free end side from the rotating center 108. In the case of the head support mechanism of the present embodiment, the length is considerably shortened corresponding to the range of L2 corresponding to only the magnetic head. Furthermore, the slider support portion 32 is made the minimum necessary size, and the conventional slider is fixed to the slider support portion with an adhesive, but the slider is fixed by ultrasonic welding or ball bonding to reduce the weight.
[0060]
Next, a specific structure of the thin film piezoelectric element unit 40 will be described with reference to FIGS. 5 and 6. FIG. 5 is a plan view of the thin film piezoelectric element unit 40. 6 is a cross-sectional view taken along line AA in FIG. In FIG. 6, the scale in the thickness direction is drawn larger than the actual size in order to help understanding.
[0061]
The thin film piezoelectric element unit 40 has left and right first thin film piezoelectric elements 40a and second thin film piezoelectric elements 40b that are bifurcated through a slit 40c and connected only at the base.
[0062]
The first thin film piezoelectric element 40a and the second thin film piezoelectric element 40b have the same structure. Its structure is as follows. The upper thin film piezoelectric element 41 and the lower thin film piezoelectric element 42 are integrally joined via a conductive adhesive 43 in a laminated state. The upper thin film piezoelectric element 41 is obtained by integrating the first electrode metal film 41a and the second electrode metal film 41b on both surfaces of the thin film piezoelectric element 41p. Further, the third electrode metal film 42c and the fourth electrode metal film 42d are integrated on both surfaces of the thin film piezoelectric body 42p. The conductive adhesive 43 is interposed between the second electrode metal film 41b and the third electrode metal film 42c, and both are integrally joined. The entire thin film piezoelectric elements 40a and 40b are covered with a flexible coating resin 44, and the left and right thin film piezoelectric elements 40a and 40b are integrated. Connection for filling the ground metal films 47a and 47b for electrically connecting the second electrode metal film 41b and the third electrode metal film 42c at the bases of both thin film piezoelectric elements 40a and 40b Holes 45a and 45b are formed.
[0063]
8 is a cross-sectional view taken along line BB in FIG. FIG. 8 is a cross-sectional view irregularly cut for easy understanding of the wiring state.
[0064]
As shown in FIG. 8, the pair of left and right first thin film piezoelectric elements 40 a and second thin film piezoelectric elements 40 b of the thin film piezoelectric element unit 40 are respectively bifurcated piezoelectric elements of the wiring flexible substrate 33 in the flexure 30. It is placed on the body support portions 33a and 33b and is integrally joined via an adhesive.
[0065]
The first thin film piezoelectric element 40a on the left side is disposed between the first and second head element wirings 34a and 34b and the ground wiring 35d. The right second thin film piezoelectric element 40b is disposed between the third and fourth head element wirings 34c, 34d and the ground wiring 35d.
[0066]
FIG. 9 shows a cross section taken along line CC in FIG. In the first thin film piezoelectric element 40 a on the left side of the thin film piezoelectric element unit 40, the first electrode metal film 41 a on the upper side of the upper thin film piezoelectric element 41 and the first thin film piezoelectric element 42 on the lower side of the lower thin film piezoelectric element 42. The fourth electrode metal film 42d is connected to the wiring terminal 35a 'of the first thin film piezoelectric element driving wiring 35a through the wire bond line 46a. Further, in the second thin film piezoelectric element 40b on the right side of the thin film piezoelectric element unit 40, the upper side of the upper first thin film piezoelectric element 41 and the lower side of the lower thin film piezoelectric element 42 are below. The fourth electrode metal film 42d is connected to the wiring terminal 35b 'of the second thin film piezoelectric element driving wiring 35b via a wire bond line 46b. A positive voltage is applied to the first thin film piezoelectric element drive wiring 35a and the second thin film piezoelectric element drive wiring 35b. Accordingly, in the thin film piezoelectric elements 40a and 40b, the first electrode metal film 41a and the fourth electrode metal film positioned on both outer sides of the two electrode metal films sandwiching the thin film piezoelectric elements 41p and 41b in a sandwich shape. A positive voltage is applied to 42d.
[0067]
In the left and right thin film piezoelectric elements 40a and 40b in the thin film piezoelectric element unit 40, ground metal films 47a and 47b are filled in the respective connection holes 45a and 45b, and the ground metal films 47a and 47b are interposed therebetween. The second electrode metal film 41b below the upper thin film piezoelectric element 41 and the third electrode metal film 42c above the lower thin film piezoelectric element 42 are connected in a short circuit, and the ground metal film 47a. , 47b are connected to the wiring terminals 35c 'of the third thin film piezoelectric element driving wiring 35c via wire bond lines 48a, 48b, respectively. The third thin film piezoelectric element driving wiring 35c is connected to the ground. Therefore, in the thin film piezoelectric elements 40a and 40b, the second electrode metal film 41b and the third electrode metal film located inside both of the two electrode metal films sandwiching the thin film piezoelectric elements 41p and 41b in a sandwich shape. A ground potential is applied to 42c.
[0068]
The head element wiring 34 including the first head element wiring 34a, the second head element wiring 34b, the third head element wiring 34c, and the fourth head element wiring 34d is retained from the crank connecting portion 33Z as an external connection terminal. It is routed to the portion 33Y and connected to the external connection wiring terminal 36 formed in the external connection terminal holding portion 33Y. Also, a thin film piezoelectric element wiring 35 comprising a first thin film piezoelectric element driving wiring 35a, a second thin film piezoelectric element driving wiring 35b, a third thin film piezoelectric element driving wiring 35c, and a ground wiring 35d. Is routed from the crank connecting portion 33Z to the external connection terminal holding portion 33Y and connected to the external connection wiring terminal 37 formed in the external connection terminal holding portion 33Y. The external connection wiring terminals 36 and 37 are connected to an external drive circuit.
[0069]
The first thin film piezoelectric element drive wiring 35a and the second thin film piezoelectric element drive wiring 35b are connected to a common high potential side drive wiring 35ab, and are connected via a wiring terminal 37 in the external connection terminal holding portion 33Y. And connected to a high potential side power supply terminal in the power supply circuit. The ground wiring 35d is connected to the ground in the power supply circuit via the wiring terminal 36 in the external connection terminal holding portion 33Y.
[0070]
Next, attachment of the slider 50 to the flexure 30 will be described. The slider 50 is attached to the slider support portion 32 at the distal end portion of the flexure 30, but the geometric center (center) of the slider 50 is ultrasonically welded to the wiring terminal 35 e of the slider support portion 32, The lower part of the front end is ultrasonically welded to the wiring terminals 35a, 35b, 35c, and 35d of the slider support portion 32 and integrally joined and fixed. The wiring terminals 34a ′, 34b ′, 34c ′, 34d ′ at the end of the head element wiring 34 and the electrode terminals 52a, 52b, 52c, 52d that connect the head element 60 in the slider 50 are electrically and physically connected. It is connected to the.
[0071]
By adjusting the height of the wiring terminal 35d, the tilt angle of the slider 50 in the pitching direction can be freely set.
[0072]
Next, the operation of the head support mechanism 100 of the embodiment configured as described above will be described.
[0073]
As shown in FIGS. 11A to 11C, the first thin film piezoelectric element 40a on the left side and the second thin film piezoelectric element 40b on the right side are applied with voltages having opposite phases. It has become. As the applied voltage, a bias voltage Vo (this voltage may be 0 volt) is given.
[0074]
For example, in the period T1, the applied voltage to the left first thin film piezoelectric element 40a increases with respect to the bias voltage Vo, and the applied voltage to the right second thin film piezoelectric element 40b is synchronized with the bias voltage. The voltage is controlled so as to decrease with respect to Vo. On the contrary, in the period T2, the applied voltage to the left first thin film piezoelectric element 40a decreases with respect to the bias voltage Vo, and the applied voltage to the right second thin film piezoelectric element 40b is biased synchronously. The voltage is controlled so as to increase with respect to the voltage Vo.
[0075]
FIG. 12B schematically shows the configuration of FIG. The left piezoelectric support portion 33a and the left first thin film piezoelectric element 40a constitute the left first beam B1. The right piezoelectric support portion 33b and the right second thin film piezoelectric element 40b constitute the right second beam B2. The slider support portion 32 constitutes the link L. The step-bending slider holding portion 32a constitutes the rotation center O of the link L. The slider 50 constitutes an arm A1 having a length d integral with the link L. A head element 60 is present at the tip of the arm A1.
[0076]
The link L is rotatable relative to the first beam B1 and the second beam B2 at both ends thereof. This is due to the constricted elastic hinge portions 33d and 33e. The elastic hinge portions 33d and 33e constitute the swing fulcrums C1 and C2. The elastic hinge portions 33d and 33e have a flexible configuration in both the pitching direction and the rolling direction of the slider 50, and give good flying characteristics of the slider 50 to the magnetic disk.
[0077]
In the period T1, for example, as shown in FIG. 12, when the first thin film piezoelectric element 40a on the left side contracts in the direction of arrow D in the length direction, the second thin film piezoelectric element 40b on the right side reversely changes to the arrow E. Stretch along the direction. In the period T2, the direction of expansion and contraction is opposite to the above.
[0078]
The flexible film 33 for wiring of the flexure 30 that is integrally bonded to the lower side of the stretching force in the opposite directions of the first thin film piezoelectric element 40a on the left side and the second thin film piezoelectric element 40b on the right side. To the piezoelectric support portions 33a and 33b.
[0079]
Piezoelectric support portions 33a and 33b to which the thin film piezoelectric elements 40a and 40b are integrally joined, and a head support portion 32 that fixes the lower edge of the front end of the slider 50, and a constricted elastic hinge portion 33d and 33e. Connected through.
[0080]
The contraction force along the arrow D direction acts on the piezoelectric support portion 33a, and at the same time, the extension force along the arrow E direction acts on the piezoelectric support portion 33b, so that the constricted elastic hinge portions 33d and 33e are interposed. Then, the head support portion 32 causes the head to swing in the direction of arrow F together with the slider support portion 32 that is the lower support. This corresponds to the period T1. In the period T2, the swinging motion of the slider support portion 32 is in the counter arrow F direction.
[0081]
The lower surface of the slider holding portion 32 of the slider 50 is supported in an unfixed state by the fulcrum protrusion 28 of the load beam 20 at the position of the wiring terminal 35 d at the geometric center of the air bearing surface of the slider. Therefore, when the slider support portion 32 swings, the swing motion is performed around the fulcrum projection 28 at the wiring terminal 35d.
[0082]
Accordingly, the slider 50 also swings around the fulcrum protrusion 28 as the center of rotation, and the head element 60 arranged at the center of the front end surface of the slider 50 rotates around the fulcrum protrusion 28 as the center of rotation. .
[0083]
That is, it moves along the arrow F direction or the counter arrow F direction, and this direction is a direction across the track on the magnetic disk 70. In FIG. 12B, d represents the radius of rotation of the head element 60 with the fulcrum protrusion 28 (slider holding portion 32) as the center of rotation.
[0084]
In the load beam 20, the beam main portion 24 to which the wiring flexible substrate 33, which is the main portion of the flexure 30, is held with respect to the base end portion 21 via a pair of leaf spring portions 27 a and 27 b. A biasing force in the normal direction to the beam surface by the plate spring portions 27a and 27b is applied to the beam main portion 24.
[0085]
The urging force in the beam main portion 24 is applied as a load load from the fulcrum projection 28 to the slider 50 via the wiring terminal 35 d of the slider support portion 32. The load load is, for example, 20 to 30 mN (millinewton). Since this load load acts between the fulcrum protrusion 28 and the slider support part 32 and expresses a frictional force, the slider support part 32 only rotates with respect to the fulcrum protrusion 28 around the fulcrum protrusion 28 as a rotation center. No misalignment other than that occurs.
FIG. 13A shows the result of measuring the response characteristics of the head with respect to the input signal. In FIG. 13, the resonance at 15 kHz (p point) is caused by the spring constant of the thin film piezoelectric element and the inertia of the slider support 32 and the slider 50.
[0086]
At this time, as shown in FIG. 13B, the slider support portion 70 is a stainless steel base and occupies a larger range than the outer dimension of the slider, and is connected to the head terminal by a ball bond. For this reason, the moment of inertia of the slider holding portion is increased.
[0087]
On the other hand, in the present application, the moment of inertia is reduced by arranging the electrode 52 of the slider 50 in FIG. 13C on the back side of the air bearing surface and bringing the connecting portion as close as possible to the rotation center of the slider.
[0088]
Further, as a means for fixing the slider, a fixing method using an adhesive has been adopted, but the slider is fixed only by the head wiring. As a result, the inertia of the rotationally driven portion can be reduced, so that the resonance is improved to the point q (20 kHz) in FIG. As a result, it is possible to increase the response speed for controlling and positioning the head.
[0089]
In the above description, in the flexure 30, the left piezoelectric support part 33a and the right piezoelectric support part 33b are separated by the slit 33c. You may comprise in the state which connected 33a, 33b to a series one-on-one. In this case, it is possible to advantageously develop cancellation of harmful vibrations in the normal direction of the thin film piezoelectric element unit 40.
[0090]
In FIG. 4, a stainless steel flexure substrate 31 is provided and the load beam and the flexure are bonded to each other by spot welding. However, the flexure substrate 31 may be directly bonded to the load beam without providing the flexure substrate 31. This can greatly reduce the cost of manufacturing the flexure. Further, in order to further reduce the moment of inertia of the slider rotating portion, the characteristics may be improved by making the slider thinner.
[0091]
Further, in FIG. 14, by connecting the electrode terminal 52 of the slider at the position of the through hole of the head wiring terminals 34a ', 34b', 34c ', 34d', the fixing strength and the fixing position accuracy can be improved.
[0092]
In the case of the head support mechanism 100 of the present embodiment described above, the slider 50 loaded with the head element 60 mounted at the tip of the load beam 20 is mounted on the tip of the load beam 20. The beam 20 is supported so as to be rotatable, and a rotational force is applied to the slider 50.
[0093]
Therefore, in the case of the head support mechanism 100 according to the present embodiment, the load beam 20 is not rotated during the minute displacement control for tracking correction of the head element 60 and the like. While the load beam 20 is stationary, a sufficiently small slider 50 is rotated with respect to the load beam 20. That is, the object to be rotated for controlling the minute displacement of the head element 60 is not the entire load beam 20 including the slider 50, but is independent of the slider 50 in a state separate from the load beam 20. The structure is a rotation.
[0094]
Therefore, the slider 50 equipped with the head element 60 has a sufficiently short dimension and a sufficiently light weight compared to a load beam corresponding to the suspension arm. Therefore, the moment of inertia of the slider 50 itself having the head element 60 is small, and the driving torque of the slider 50 may be sufficiently small. And since it is small and lightweight, the response in tracking correction etc. is excellent. Therefore, the accuracy of tracking correction and the like becomes extremely high. It is possible to provide a head support mechanism of a disk device that can displace the head element with high accuracy and high speed with high speed response of the head element displacement for tracking correction or the like for the disk.
[0095]
The head support mechanism is preferably applied to a magnetic disk device, but is not necessarily limited to a magnetic disk device, and may be applied to an optical disk device, a magneto-optical disk device, or the like.
[0096]
【The invention's effect】
According to the head support mechanism of the present invention, a head element is mounted, a slider having an electrode terminal electrically connected to the head element, and the slider is supported and connected to the electrode terminal to exchange signals. A slider support portion having a head wiring terminal, and the slider is supported by the slider support portion in a state where the electrode terminal and the head wiring terminal are in close contact with each other.
[0097]
As a result, the electrode terminal and the head wiring terminal are brought into close contact with each other, and the slider support portion is made of a resin structure coated with an insulating film such as polyimide resin. When the part is connected vertically, the metal member necessary for fixing the slider support part becomes unnecessary. Therefore, a slider that is sufficiently light in weight and has a sufficiently small moment of inertia can be obtained, and the drive torque of the slider due to the operation of the displacement member may be sufficiently small, and the response in tracking correction and the like is excellent. Further, since the metal member is not necessary, the manufacturing cost can be reduced.
[0098]
In addition, by opening a metal welding hole for connecting the electrode terminal and the head wiring terminal on the back surface of the support surface of the slider support portion, the electrode terminal and the head wiring terminal are connected via the metal welding hole. Since the connection is made in close contact by ultrasonic welding, the electrode terminal and the head wiring terminal can be reliably connected, and displacement of the connection position can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an entire head support mechanism according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a head support mechanism according to an embodiment of the present invention.
FIGS. 3A and 3B are a perspective view and a rear view showing a slider in the head support mechanism according to the embodiment of the invention. FIGS.
FIG. 4 is an exploded perspective view showing a flexure structure in the head support mechanism according to the embodiment of the invention.
FIG. 5 is a plan view showing a thin film piezoelectric element unit in the head support mechanism according to the embodiment of the invention.
6 is a cross-sectional view taken along line AA in FIG.
FIG. 7 is a plan view of the tip portion of the flexure in the head support mechanism according to the embodiment of the invention.
8 is a cross-sectional view taken along line BB in FIG. 7 and a cross-sectional view cut irregularly for easy understanding of the wiring state.
FIG. 9 is a cross-sectional view taken along the line CC in FIG. 7 and a cross-sectional view cut irregularly for easy understanding of the wiring state.
FIG. 10 is a side view of the head support mechanism according to the embodiment of the invention.
FIG. 11 is a driving explanatory diagram of a thin film piezoelectric element unit in the head support mechanism according to the embodiment of the invention.
FIG. 12 is a drive explanatory diagram of a head support mechanism according to an embodiment of the present invention.
FIG. 13 is a diagram showing frequency response characteristics in the head support mechanism according to the embodiment of the invention.
FIG. 14 is a cross-sectional view when the slider according to the embodiment of the present invention is attached to the head support portion by ultrasonic welding.
FIG. 15 is a cross-sectional view when the slider according to the embodiment of the present invention is attached to the head support portion by a ball bond.
FIG. 16 is a plan view showing an example of a head support mechanism of a disk device according to a conventional technique.
[Explanation of symbols]
10 …… Base plate
20 …… Load beam
21 …… Base end
22 …… Neck
23 …… Opening
24 …… Beam main part
25 …… Tip support part
26 …… Regulation Department
27a, 27b ... leaf spring
28 …… Protrusion protrusion
30 ... Flexure
31 ... Flexure substrate
32, 70 ... Slider support
33 …… Flexible substrate for wiring
33X: Flexible substrate main part
33Y: External connection terminal holder
33Z …… Crank connecting part
33a, 33b ...... Forked piezoelectric support
33c …… Slit
33d, 33e …… Elastic hinge part
33f …… Flexure tip
34. Head element wiring
35 …… Wiring for thin film piezoelectric element
40 …… Thin film piezoelectric element unit
40a: first thin film piezoelectric element
40b ...... second thin film piezoelectric element
40c …… Slit
50 …… Slider
60 …… Head element
61 …… Ball bonding
62 …… Ultrasonic welding probe

Claims (3)

A slider mounted with a head element and having an electrode terminal electrically connected to the head element;
A slider support unit having a head wiring terminal for supporting the slider and connecting the electrode terminal to exchange signals;
In a state where the electrode terminal and the head wiring terminal are in close contact, the slider is supported by the slider support portion ,
The electrode terminal is disposed in the vicinity of the center of the slider on the supported surface of the slider,
On the back surface of the support surface of the slider support portion, through the head element wiring, open a connection hole reaching the electrode terminal,
A head support mechanism, wherein the electrode terminal and the head wiring terminal are connected by ball bonding through the connection hole . A slider mounted with a head element and having an electrode terminal electrically connected to the head element;
A slider support unit having a head wiring terminal for supporting the slider and connecting the electrode terminal to exchange signals;
In a state where the electrode terminal and the head wiring terminal are in close contact, the slider is supported by the slider support portion,
The electrode terminal is disposed in the vicinity of the center of the slider on the supported surface of the slider,
On the back surface of the support surface of the slider support portion, a connection hole reaching the head wiring terminal is opened,
A head support mechanism, wherein the electrode terminal and the head wiring terminal are connected by ultrasonic welding through the connection hole . In the head support mechanism according to claim 1 or 2,
The head support mechanism , wherein the slider support portion provided with the connection hole is made of polyimide .

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