JP7225917B2 - Piezoelectric driving device, manufacturing method of piezoelectric driving device, and robot - Google Patents

Description

TECHNICAL FIELD The present invention relates to a piezoelectric drive device, a method for manufacturing a piezoelectric drive device, and a robot.

An ultrasonic actuator is a driving device that is used in, for example, a lens driving unit and capable of driving a lens accurately. In such an ultrasonic actuator, a piezoelectric vibrating body having a piezoelectric element is brought into contact with the driven body to vibrate the piezoelectric vibrating body, thereby driving the driven body.

Patent Document 1 discloses an ultrasonic motor including a vibrator composed of a diaphragm and a piezoelectric element, and a flexible substrate electrically connected to the piezoelectric element, and a lens holding member that is linearly moved by the driving force generated by the ultrasonic motor. and a lens secured to a lens retaining member. In such a device, electrical connection is achieved by crimping a flexible substrate against the electrodes of the piezoelectric element.

On the other hand, a structure has been studied in which the electrodes of the piezoelectric element are pulled out to the end face of the diaphragm, and the terminal provided on the end face and the flexible substrate are electrically connected. Specifically, the electrodes provided on the main surface of the film-shaped piezoelectric element are pulled out to the end surface of the diaphragm that supports the piezoelectric element to form the terminals. Then, the terminals formed on the end face of the diaphragm and the terminals of the flexible substrate are electrically connected. Further, by stacking another diaphragm on the main surface of the piezoelectric element, a structure is formed in which the piezoelectric element is sandwiched between two diaphragms. At that time, the electrode of the piezoelectric element and another diaphragm are adhered via an adhesive.

JP 2015-133864 A

In the structure as described above, the electrodes of the piezoelectric element are adhered to another diaphragm via an adhesive, while the terminals formed by drawing out the electrodes are electrically connected to the flexible substrate. However, even if the constituent materials of the electrodes are appropriately selected, there is a problem that it is difficult to reduce the contact resistance in electrical connection while increasing the adhesive strength in adhesion.

A piezoelectric driving device according to an application example of the present invention includes:
a first piezoelectric element unit having a first diaphragm and a first piezoelectric element having an electrode and provided on the first diaphragm;
a second piezoelectric element unit having a second diaphragm and a second piezoelectric element provided on the second diaphragm;
The first piezoelectric element unit and the second piezoelectric element unit are bonded such that the first piezoelectric element and the second piezoelectric element are positioned between the first diaphragm and the second diaphragm. an adhesive;
a first metal film provided between the electrode and the adhesive;
a conductive second metal film provided between the electrode and the first metal film and on an end surface of the first diaphragm;
a wiring substrate electrically connected to the second metal film;
a driven body driven by the vibration of the first piezoelectric element and the vibration of the second piezoelectric element;
with
The adhesive is an epoxy adhesive, a silicone adhesive, a urethane adhesive or an acrylic adhesive,
a combination in which the main material of the first metal film is TiW and the main material of the second metal film is Ni ;
meet .

1 is a plan view showing a piezoelectric drive device according to a first embodiment; FIG. FIG. 2 is a plan view showing the arrangement of electrodes of the vibrator shown in FIG. 1; FIG. 2 is a plan view showing the arrangement of electrodes of the vibrator shown in FIG. 1; FIG. 2 is a plan view showing the arrangement of wiring layers of the vibrator shown in FIG. 1; FIG. 2 is a plan view showing the arrangement of wiring layers of the vibrator shown in FIG. 1; FIG. 6 is a cross-sectional view taken along the line AA of FIGS. 2 to 5; FIG. 6 is a cross-sectional view taken along line BB of FIGS. 2 to 5; FIG. 6 is a sectional view taken along line CC of FIGS. 2 to 5; FIG. 6 is a cross-sectional view taken along line DD of FIGS. 2 to 5; FIG. 6 is a cross-sectional view taken along line EE of FIGS. 2 to 5; 11 is a cross-sectional view showing a state in which the piezoelectric element unit shown in FIG. 10 is electrically connected to a wiring substrate; FIG. FIG. 12 is a partially enlarged view of FIG. 11; FIG. 11 is a sectional view showing a state in which a plurality of piezoelectric element units shown in FIG. 10 are laminated and electrically connected to a wiring board; 4 is a diagram showing an example of an alternating voltage applied to the vibrating section shown in FIG. 3; FIG. 2 is a plan view showing a driving state of the vibrating portion shown in FIG. 1; FIG. 2 is a plan view showing a driving state of the vibrating portion shown in FIG. 1; FIG. FIG. 2 is a cross-sectional view taken along line FF in FIG. 1; 2 is a block diagram showing the control device of FIG. 1; FIG. It is a cross-sectional view showing a part of the piezoelectric driving device according to the second embodiment. It is process drawing which shows the manufacturing method of the piezoelectric drive device which concerns on 3rd Embodiment. It is a figure for demonstrating the manufacturing method of the piezoelectric drive device which concerns on 3rd Embodiment. It is a figure for demonstrating the manufacturing method of the piezoelectric drive device which concerns on 3rd Embodiment. It is a figure for demonstrating the manufacturing method of the piezoelectric drive device which concerns on 3rd Embodiment. It is a perspective view which shows the robot based on 4th Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a piezoelectric drive device, a method of manufacturing a piezoelectric drive device, and a robot according to the present invention will be described below in detail with reference to the accompanying drawings.

<First embodiment>
First, the piezoelectric driving device according to the first embodiment will be described.

FIG. 1 is a plan view showing the piezoelectric driving device according to the first embodiment. FIG. 2 and 3 are plan views showing the arrangement of electrodes of the vibrator shown in FIG. 1, respectively. 4 and 5 are plan views showing the arrangement of the wiring layers of the vibrator shown in FIG. 1, respectively. FIG. 6 is a cross-sectional view taken along line AA of FIGS. 2 to 5. FIG. FIG. 7 is a cross-sectional view taken along line BB of FIGS. 2 to 5. FIG. FIG. 8 is a sectional view taken along line CC of FIGS. 2 to 5. FIG. FIG. 9 is a sectional view taken along line DD of FIGS. 2 to 5. FIG. FIG. 10 is a cross-sectional view taken along line EE of FIGS. 2 to 5. FIG.

In the following, for convenience of explanation, the three axes orthogonal to each other are defined as the X-axis, the Y-axis, and the Z-axis, the direction parallel to the X-axis is the X-axis direction, the direction parallel to the Y-axis is the Y-axis direction, and the Z-axis. The parallel direction is also called the Z-axis direction. Also, the arrow side of each axis is also called "plus side", and the opposite side to the arrow is also called "minus side".

In the following description, "provided on a surface" means either the state of being directly positioned on the surface, or the state of being indirectly positioned on the surface via some kind of intervening material. Point.

A piezoelectric drive device 1 shown in FIG. 1 includes a disk-shaped rotor 2 as a driven body rotatable around a central axis O, and a vibration actuator 3 that abuts on an outer peripheral surface 21 of the rotor 2 . In such a piezoelectric drive device 1, when the vibration actuator 3 is vibrated, the rotor 2 rotates around the central axis O parallel to the X axis. Note that the configuration of the piezoelectric driving device 1 is not limited to the configuration shown in FIG. For example, a plurality of vibration actuators 3 may be arranged along the circumferential direction of the rotor 2 and the rotor 2 may be rotated by driving the plurality of vibration actuators 3 . Also, the vibration actuator 3 may be in contact with the main surface 22 of the rotor 2 instead of the outer peripheral surface 21 of the rotor 2 . Further, the driven body is not limited to a rotating body such as the rotor 2, and may be, for example, a linearly moving slider.

Further, in this embodiment, the rotor 2 is provided with an encoder 9 , and the behavior of the rotor 2 , particularly the amount of rotation and angular velocity, can be detected by the encoder 9 . The encoder 9 is not particularly limited. For example, it may be an incremental encoder that detects the amount of rotation of the rotor 2 when it rotates. It may be an absolute type encoder that detects the position.

The encoder 9 according to the present embodiment has a scale 91 fixed to the surface of the rotor 2 on the plus side of the X axis, and an optical element 92 provided on the plus side of the X axis of the scale 91 . The scale 91 has a disk shape, and a pattern (not shown) is provided on the surface on the positive side of the X axis. On the other hand, the optical element 92 has a light emitting element 921 that emits light toward the pattern of the scale 91 and an imaging element 922 that images the pattern of the scale 91 . The encoder 9 having such a configuration can detect the amount of rotation, the driving speed, the absolute position, etc. of the rotor 2 by performing template matching on the image of the pattern acquired by the imaging device 922 . However, the configuration of the encoder 9 is not limited to the above configuration. For example, instead of the imaging element 922, a configuration including a light receiving element that receives reflected light or transmitted light from the scale 91 may be used.

The vibration actuator 3 also includes a vibrating body 4 , a biasing member 5 that biases the vibrating body 4 toward the rotor 2 , and a control device 7 that controls driving of the vibrating body 4 .

2 to 5, the vibrating body 4 includes a vibrating portion 41, a support portion 42 that supports the vibrating portion 41, a connection portion 43 that connects the vibrating portion 41 and the support portion 42, and a tip portion 44 connected to the vibrating portion 41 and transmitting the vibration of the vibrating portion 41 to the rotor 2 .

The vibrating portion 41 has a thickness direction in the X-axis direction and has a plate-like shape extending in the YZ plane including the Y-axis and the Z-axis. bending vibration. Further, the vibrating portion 41 has a substantially rectangular shape with a major axis extending in the Y-axis direction, which is the stretching direction, in plan view from the X-axis direction. However, the shape of the vibrating portion 41 is not particularly limited as long as it can exhibit its function.

3, the vibrating portion 41 includes driving piezoelectric elements 6A to 6F for vibrating the vibrating portion 41, a detection piezoelectric element 6G for detecting the vibration of the vibrating portion 41, have

The piezoelectric elements 6C and 6D are arranged along the longitudinal direction of the vibrating portion 41, that is, along the Y-axis direction, respectively, in the central portion of the vibrating portion 41 in the Z-axis direction. The piezoelectric element 6C is located on the Y-axis direction plus side of the piezoelectric element 6D, while the piezoelectric element 6D is located on the Y-axis direction minus side of the piezoelectric element 6C. A piezoelectric element 6G is arranged between the piezoelectric element 6C and the piezoelectric element 6D. Also, the piezoelectric element 6C and the piezoelectric element 6D are electrically connected to each other.

A single piezoelectric element may be provided instead of the two piezoelectric elements 6C and 6D.

Piezoelectric elements 6A and 6B are arranged side by side in the longitudinal direction of the vibrating section 41 on the positive side of the vibrating section 41 in the Z-axis direction with respect to the piezoelectric elements 6C and 6D. 6F are arranged side by side in the longitudinal direction of the vibrating portion 41 . Further, the piezoelectric elements 6A to 6F expand and contract in the longitudinal direction of the vibrating portion 41 when energized. Also, the piezoelectric elements 6A and 6F are electrically connected to each other, and the piezoelectric elements 6B and 6E are electrically connected to each other. As will be described later, alternating voltages having different phases and the same frequency are applied to the piezoelectric elements 6C and 6D, the piezoelectric elements 6A and 6F, and the piezoelectric elements 6B and 6E. , the vibrating portion 41 can be bent and vibrated in an S-shape in its plane.

The piezoelectric element 6G is located between the piezoelectric elements 6C and 6D. That is, the piezoelectric element 6G is arranged side by side with respect to the piezoelectric elements 6C and 6D in the expansion/contraction direction, that is, in the Y-axis direction. The piezoelectric element 6G receives an external force corresponding to the vibration of the vibrating portion 41 accompanying the driving of the piezoelectric elements 6A to 6F, and outputs a signal corresponding to the received external force. Therefore, the vibration state of the vibrating portion 41 can be detected based on the signal output from the piezoelectric element 6G. Note that "the piezoelectric element 6G is arranged side by side with respect to the piezoelectric elements 6C and 6D in the expansion/contraction direction" means an area extending the piezoelectric element 6C in the expansion/contraction direction and an area extending the piezoelectric element 6D in the expansion/contraction direction. It means that at least a part of the piezoelectric element 6G is located in the overlapping area, and preferably, it means that the entire piezoelectric element 6G is located.

The piezoelectric element 6G is arranged at a node of the bending vibration of the vibrating portion 41 . A bending vibration node is a portion where the amplitude in the Z-axis direction is substantially zero, that is, a portion where bending vibration does not substantially occur. In this way, by arranging the piezoelectric element 6G so as to line up with the piezoelectric elements 6C and 6D in the expansion/contraction direction thereof, and by arranging the piezoelectric element 6G in a portion including the node of bending vibration of the vibrating section 41, the piezoelectric element 6G vibrates. The stretching vibration of the portion 41 in the Y-axis direction is easily transmitted, and the bending vibration of the vibrating portion 41 in the Z-axis direction is less likely to be transmitted. That is, it is possible to reduce the sensitivity to bending vibration while increasing the sensitivity to stretching vibration. Therefore, the stretching vibration of the vibrating portion 41 in the Y-axis direction can be detected with higher accuracy by the piezoelectric element 6G.

However, the arrangement of the piezoelectric element 6G is not particularly limited as long as it can detect the stretching vibration of the vibrating section 41 in the Y-axis direction. may Also, the piezoelectric element 6G may be divided into a plurality of parts.

Further, the support portion 42 supports the vibrating portion 41 . The support portion 42 has a U-shape surrounding the base end side of the vibrating portion 41, that is, the negative side in the Y-axis direction when viewed from above in the X-axis direction. However, the shape and arrangement of the support portion 42 are not particularly limited as long as the function can be exhibited.

The connecting portion 43 connects the portion of the vibrating portion 41 that becomes a node of bending vibration, specifically, the center portion of the vibrating portion 41 in the Y-axis direction and the support portion 42 . However, the configuration of the connecting portion 43 is not particularly limited as long as it can exhibit its function.

As shown in FIGS. 6 to 10, the vibrating portion 41, the supporting portion 42, and the connecting portion 43 described above are configured by bonding two piezoelectric element units 60 facing each other. That is, in the cross-sectional views shown in FIGS. 6 to 10, the configurations of the piezoelectric element units 60 satisfy a mirror image relationship with respect to the line passing through the middle of them.

Further, each piezoelectric element unit 60 is composed of a laminated body in which a plurality of layers are laminated, and each of these layers is a piezoelectric body, an electrode, a wiring layer, and an insulating film, which will be described later.

2 to 5 are plan views of respective layers of the laminate constituting the piezoelectric element unit 60, respectively. Each layer shown in FIGS. 2 to 5 is electrically insulated via an insulating film (not shown).

First, the first electrode 601 shown in FIG. 2 is provided on the first surface 613a (first main surface) shown in FIG. common electrode.

Six second electrodes 603 shown in FIG. 3 are individual electrodes for the piezoelectric elements 6A to 6F, and one third electrode 604 shown in FIG. 3 is an individual electrode for the piezoelectric element 6G. The second electrode 603 and the third electrode 604 are opposed to the first electrode 601 via a piezoelectric body 602, which will be described later.

Furthermore, one first wiring layer 605 shown in FIG. 4 is a wiring for leading out the first electrode 601 to the outside. The first wiring layer 605 is electrically connected to the first electrode 601 via a contact (not shown). The first wiring layer 605 is routed through the connection portion 43 to the end portion of the support portion 42 on the negative side in the Y-axis direction.

Also, the six first wiring layers 606 shown in FIG. 5 are wiring for drawing out the second electrode 603 or the third electrode 604 to the outside. The first wiring layer 606 is electrically connected to the second electrode 603 or the third electrode 604 via contacts (not shown). The first wiring layer 606 is routed through the connecting portion 43 to the end of the supporting portion 42 on the negative side in the Y-axis direction.

6 to 8 are cross-sectional views of the vibrating portion 41 shown in FIGS. 2 to 5, and the positions of the cut surfaces are different from each other. 9 and 10 are sectional views of the support portion 42 shown in FIGS. 2 to 5 described above. In the following description, of the two piezoelectric element units 60 shown in FIGS. 6 to 10, the piezoelectric element unit 60 located on the negative side of the X axis in each figure will be described as a representative.

The piezoelectric element unit 60 shown in FIGS. 6 to 8 includes a diaphragm 61, driving piezoelectric elements 60A, 60B, 60C, and 60D arranged on a first surface 613a (first main surface) of the diaphragm 61, A first insulating film 63 covering 60E, 60F and a detecting piezoelectric element 60G, each of the piezoelectric elements 60A to 60G, and a second insulating film covering a first rear surface 615 which is the surface of the vibration plate 61 on the negative side of the X axis. 64 and a third insulating film 65 covering the end surface 611 of the diaphragm 61 .

6 to 8, the piezoelectric elements 60A to 60F are arranged on the first electrode 601 arranged on the first surface 613a of the diaphragm 61 and on the surface of the first electrode 601 on the positive side of the X axis. and a second electrode 603 arranged on the surface of the piezoelectric body 602 on the positive side of the X axis. That is, the first electrode 601 is provided on the surface 6021 of the piezoelectric body 602 on the negative side of the X axis, and the second electrode 603 is provided on the surface 6022 of the piezoelectric body 602 on the positive side of the X axis. The second electrode 603 is a drive electrode that vibrates the piezoelectric bodies 602 of the drive piezoelectric elements 60A to 60F based on the drive signal.

7, the piezoelectric element 60G includes the first electrode 601 arranged on the first surface 613a of the diaphragm 61 and the piezoelectric element 601 arranged on the surface of the first electrode 601 on the X-axis plus side. It has a body 602 and a third electrode 604 arranged on the surface of the piezoelectric body 602 on the X-axis plus side. That is, the first electrode 601 is provided on the surface 6021 of the piezoelectric body 602 on the negative side of the X axis, and the third electrode 604 is provided on the surface 6022 of the piezoelectric body 602 on the positive side of the X axis. The third electrode 604 is a detection electrode that outputs a detection signal corresponding to the vibration of the piezoelectric body 602 of the detection piezoelectric element 60G to the control device 7, which will be described later.

The two piezoelectric element units 60 are bonded via an adhesive 691 with the surfaces on which the piezoelectric elements 60A to 60G are arranged facing each other. By bonding a plurality of piezoelectric element units 60 together in this manner, the output of the piezoelectric drive device 1 can be increased.

Examples of the adhesive 691 include epoxy-based adhesive, silicone-based adhesive, urethane-based adhesive, acrylic-based adhesive, and the like. Among these, epoxy-based adhesives are preferably used from the viewpoint of adhesive strength, heat resistance, and the like.

Further, the first electrode 601 shown in each figure is an electrode common to the piezoelectric elements 6A to 6G, but is not limited to this, and is divided for each piezoelectric element and connected to each other by wiring or the like. may be

On the other hand, FIGS. 9 and 10 show a cross section of the support portion 42, but the support portion 42 is not provided with the piezoelectric elements 60A to 60G. Instead, a spacer structure 68 is provided having the same structure as the piezoelectric elements 60A-60G. The spacer structure 68 has the same structure as the piezoelectric elements 60A to 60G, but the parts corresponding to the electrodes are not connected to wiring, or are not energized even if they are connected.

9 and 10, the supporting portion 42 includes the diaphragm 61, the spacer structure 68 arranged on the first surface 613a of the diaphragm 61, and the second structure covering the spacer structure 68. 1 insulating film 63 , a second insulating film 64 covering the first rear surface 615 of the diaphragm 61 , and a third insulating film 65 covering the end surface 611 of the diaphragm 61 .

A first insulating film 63 shown in FIGS. 6 to 10 is provided to cover the piezoelectric elements 60A to 60G or the spacer structure 68. As shown in FIG. Thereby, insulation between the piezoelectric elements 60A to 60G or the spacer structure 68 and the first wiring layers 605 and 606 is achieved.

Also, the second insulating film 64 shown in FIGS. 6 to 10 is provided so as to cover the first rear surface 615 of the diaphragm 61 . Thereby, insulation of the first back surface 615 of the diaphragm 61 is achieved.

Furthermore, the third insulating film 65 shown in FIGS. 6 to 10 is provided so as to cover the end surface 611 of the diaphragm 61 . Thereby, insulation of the end face 611 of the diaphragm 61 is achieved. Since the third insulating film 65 is an insulating film continuous from the first insulating film 63, it also covers the end surfaces of the piezoelectric elements 60A to 60G and the spacer structure 68. FIG. As a result, the first insulating film 63 and the third insulating film 65 cover the entire structure located on the X-axis plus side of the diaphragm 61 as a single film. As a result, the diaphragm 61, the piezoelectric elements 60A to 60G and the spacer structure 68 are surrounded by the first insulating film 63, the second insulating film 64 and the third insulating film 65. FIG. Thereby, insulation and weather resistance can be improved, and a highly reliable vibrating body 4 can be obtained.

Also, the first wiring layers 605 and 606 are routed on the surface 633 of the first insulating film 63 on the X-axis plus side, as shown in FIG. As shown in FIG. 10, the first wiring layer 605 is routed to the end of the supporting portion 42 on the negative side in the Y-axis direction. Also, although not shown, the first wiring layer 606 is the same.

The piezoelectric element unit 60 shown in FIG. 10 further has a second wiring layer 607 provided on the end face 611 of the vibration plate 61 via the end face of the spacer structure 68 . This second wiring layer 607 is a wiring layer continuous from the first wiring layers 605 and 606 . Therefore, the electrodes of the piezoelectric elements 60A to 60G are drawn out to the end surface 611 of the vibration plate 61 through the first wiring layers 605, 606 and the second wiring layer 607. FIG.

By providing such a second wiring layer 607, in the piezoelectric element unit 60, on the first surface 613a which is the surface of the diaphragm 61 on the positive side of the X axis and on the first rear surface 615 which is the surface on the negative side of the X axis. Instead, it becomes possible to establish an electrical connection with the outside on the end surface 611 .

11 is a cross-sectional view showing a state in which the piezoelectric element unit 60 shown in FIG. 10 is electrically connected to the wiring board 8. As shown in FIG.

A wiring board 8 shown in FIG. 11 is a wiring board that electrically connects the piezoelectric element unit 60 and the control device 7 shown in FIG. The wiring board 8 includes a flexible board 81 and wiring 82 provided on one surface of the flexible board 81 . A plurality of wirings 82 are routed so as to correspond to the plurality of second wiring layers 607 included in the piezoelectric element unit 60 .

Including the flexible substrate 81 in the wiring board 8 facilitates handling of the wiring board 8 . Therefore, the size of the piezoelectric driving device 1 can be reduced. Moreover, even if the wiring board 8 thermally expands, the distortion is easily absorbed by the bending of the wiring board 8 itself.

Further, the piezoelectric drive device 1 shown in FIG. 11 includes two piezoelectric element units 60 stacked on each other. It is electrically connected to the wiring board 8 via the wiring layer 607 . Therefore, even when a plurality of piezoelectric element units 60 are stacked, it is possible to collectively connect the stacked piezoelectric element units 60 and the wiring board 8 . Therefore, it is not necessary to connect the piezoelectric element units 60 to the wiring board 8 while stacking them one by one.

Further, in the piezoelectric drive device 1 shown in FIG. 11, the piezoelectric element unit 60 and the wiring board 8 are mechanically and electrically connected via a conducting member 83 as shown in FIG.

Examples of the conductive member 83 include solder, brazing material, conductive metal such as metal paste, anisotropic conductive paste, anisotropic conductive material such as anisotropic conductive sheet, conductive adhesive, wire bonding material, and the like. is mentioned. Of these, the conductive member 83 that electrically connects the second wiring layer 607 and the wiring board 8 is preferably made of a conductive metal or an anisotropic conductive material. By using these materials, electrical connection can be made efficiently at a relatively low temperature and with low contact resistance. Therefore, the production efficiency of the piezoelectric drive device 1 can be enhanced.

Also, of the two piezoelectric element units 60 shown in FIG. 10, the lower piezoelectric element unit 60 is referred to as "first piezoelectric element unit 60a" and the upper piezoelectric element unit 60 is referred to as "second piezoelectric element unit 60b".

At this time, in FIG. 10, the first wiring layer 605 of the first piezoelectric element unit 60a and the first wiring layer 605 of the second piezoelectric element unit 60b face each other with the adhesive 691 interposed therebetween. An element unit 60a and a second piezoelectric element unit 60b are laminated. Also, although not shown, the first wiring layer 606 is the same.

In FIG. 11 , the first piezoelectric element unit 60 a and the second piezoelectric element unit 60 b can be connected to the wiring substrate 8 via the conductive member 83 . Along with this, the piezoelectric elements 60A are connected to each other between the first piezoelectric element unit 60a and the second piezoelectric element unit 60b. As a result, the "piezoelectric element 6A" is configured from the two piezoelectric elements 60A.

The same is true for the other piezoelectric elements 60B to 60G. Two piezoelectric elements 60B form a "piezoelectric element 6B", two piezoelectric elements 60C form a "piezoelectric element 6C", and two piezoelectric elements 60D form a "piezoelectric element 6B". Two piezoelectric elements 60E constitute a "piezoelectric element 6E", two piezoelectric elements 60F constitute a "piezoelectric element 6F", and two piezoelectric elements 60G constitute a "piezoelectric element 6G". It is configured.

The constituent material of the piezoelectric body 602 is not particularly limited, and examples thereof include lead zirconate titanate (PZT), barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, and zinc oxide. , barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, and lead scandium niobate. In addition to the piezoelectric ceramics described above, polyvinylidene fluoride, crystal, or the like may be used as the piezoelectric body 602 .

Also, the method for forming the piezoelectric body 602 is not particularly limited, and it may be formed from a bulk material, or may be formed using a sol-gel method or a sputtering method. In this embodiment, the piezoelectric body 602 is formed using the sol-gel method. That is, the piezoelectric elements 60A to 60G (first piezoelectric elements) according to this embodiment have the piezoelectric body 602 in contact with the first electrode 601, the second electrode 603 and the third electrode 604. 602 is a sol-gel film. As a result, for example, the piezoelectric body 602 can be thinner than when it is formed from a bulk material, and the thickness of the vibration actuator 3 can be reduced.

Here, FIG. 12 is a partially enlarged view of FIG.
As shown in FIG. 12, the first piezoelectric element unit 60a includes a first wiring layer 605 provided on the surface 633 of the first insulating film 63 on the positive side of the X axis, and a wiring layer 605 on the negative side of the Y axis of the third insulating film 65. and a second wiring layer 607 provided on the surface 651 .

Among them, as shown in FIG. 12, the first wiring layer 605 includes a first metal film 6052 located on the second piezoelectric element unit 60b side, a second metal film 6054 located on the first insulating film 63 side, It is composed of a multilayer film containing The first metal film 6052 is adhered to the second piezoelectric element unit 60b with an adhesive 691 interposed therebetween.

On the other hand, the second wiring layer 607 is composed of one layer of the second metal film 6054 . The second metal film 6054 is joined to the wiring substrate 8 via the conductive member 83 and electrically connected.

In this embodiment, the main material of the first metal film 6052 and the main material of the second metal film 6054 satisfy a specific combination. Specifically, the following four combinations are mentioned. Here, the main material means the material with the largest weight ratio among the materials constituting the metal film.

- First combination TiW and Au are mentioned as a first combination.

Since the main material of the first metal film 6052 is TiW, the affinity between the first wiring layer 605 and the adhesive 691 can be enhanced, and the adhesive force can be enhanced. As a result, peeling of the adhesive 691 is suppressed, and the reliability of the piezoelectric drive device 1 can be further enhanced.

The TiW mentioned above means a titanium-tungsten alloy. A titanium-tungsten alloy refers to an alloy containing both Ti and W. In this case, the total content of Ti and W in the first metal film 6052 is preferably 70% by mass or more. As long as Ti and W are contained within this range, the first wiring layer 605 can exhibit the above-described effects, so any element can be added as an additive or impurity. Among these, examples of additives include N, Al, Ni, Cu, Cr, Ru, Ta, and Si.

Although the film thickness of the first metal film 6052 whose main material is TiW is not particularly limited, it is preferably 10 nm or more and 100 nm or less, more preferably 25 nm or more and 50 nm or less. If the film thickness is within this range, the effect of enhancing the affinity with the adhesive 691 can be sufficiently exhibited, and the time required for film formation of the first wiring layer 605 can be prevented from becoming longer.

The first metal film 6052 is formed by, for example, sputtering, physical vapor deposition such as vacuum vapor deposition, or chemical vapor deposition such as CVD.

Since the main material of the second metal film 6054 is Au, the contact resistance between the second wiring layer 607 and the conductive member 83 can be reduced. As a result, the electrical conductivity between the first piezoelectric element unit 60a and the wiring board 8 is enhanced, and the piezoelectric drive device 1 in which wasteful power consumption is suppressed can be realized. In addition, since the adhesion between TiW and Au is relatively good, there is an effect that problems such as interfacial separation are less likely to occur.

Note that the above-mentioned Au includes not only simple Au but also Au-based alloys containing 70% by mass or more of Au. As long as Au is contained within this range, the second metal film 6054 can exhibit the above-described effects, so any element can be added as an additive or impurity. Among these, examples of additives include Ge, Ni, Si, Sn, Zn, Ag, Cu, and Pt.

Although the film thickness of the second metal film 6054 mainly made of Au is not particularly limited, it is preferably 0.10 μm or more and 5.0 μm or less, more preferably 1.0 μm or more and 2.0 μm or less. If the film thickness is within this range, the conductivity of the second metal film 6054 is enhanced, so that the resistance of the conduction path continuing from the first wiring layer 605 to the second wiring layer 607 can be reduced. As a result, the piezoelectric driving device 1 with low power consumption can be obtained. In addition, sufficient bonding strength can be ensured between the second wiring layer 607 and the conductive member 83 .

The second metal film 6054 is formed by, for example, a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method, or a chemical vapor deposition method such as a CVD method, in addition to the plating method.

- Second combination TiW and Ni are listed as a second combination.

Since the main material of the first metal film 6052 is TiW, the same effects as in the case of the first combination can be obtained.

Since the main material of the second metal film 6054 is Ni, the second metal film 6054 having a sufficient thickness can be formed in a relatively short time. That is, since Ni can be formed into a film by a plating method, a sufficient film thickness can be secured in a short time. Also, the volume resistivity is relatively small. Therefore, it is possible to easily obtain the second metal film 6054 with a low resistance in the conduction path. In addition, since the adhesion between TiW and Ni is relatively good, there is also an effect that problems such as interfacial separation are less likely to occur.

In addition to Ni alone, Ni includes Ni-based alloys containing 70% by mass or more of Ni. As long as Ni is contained within this range, the second metal film 6054 can exhibit the above-described effects, and therefore any element can be added as an additive or impurity. Among these, examples of additives include P, B, N, and the like.

Although the film thickness of the second metal film 6054 mainly made of Ni is not particularly limited, it is preferably 0.10 μm or more and 5.0 μm or less, more preferably 1.0 μm or more and 2.0 μm or less. If the film thickness is within this range, the conductivity of the second metal film 6054 is enhanced, so that the resistance of the conduction path continuing from the first wiring layer 605 to the second wiring layer 607 can be reduced. As a result, the piezoelectric driving device 1 with low power consumption can be obtained. In addition, since the second metal film 6054 also imparts a buffer effect, sufficient bonding strength can be ensured in bonding the second wiring layer 607 and the conductive member 83 .

The second metal film 6054 is formed by, for example, a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method, or a chemical vapor deposition method such as a CVD method, in addition to the plating method.

- Third combination Furthermore, Ni and Au can be mentioned as a third combination.

Since the main material of the first metal film 6052 is Ni, the affinity between the first wiring layer 605 and the adhesive 691 can be enhanced, and the adhesive force can be enhanced. As a result, peeling of the adhesive 691 is suppressed, and the reliability of the piezoelectric drive device 1 can be further enhanced.

In addition to Ni alone, Ni includes Ni-based alloys containing 70% by mass or more of Ni. If Ni is contained within this range, the first metal film 6052 can exhibit the above-described effects, and therefore any element can be added as an additive or impurity. Among these, examples of additives include P, B, N, and the like.

Although the film thickness of the first metal film 6052 mainly made of Ni is not particularly limited, it is preferably 0.10 μm or more and 5.0 μm or less, more preferably 1.0 μm or more and 2.0 μm or less. If the film thickness is within this range, the effect of enhancing the affinity with the adhesive 691 can be sufficiently exhibited, and the first wiring layer 605 can be prevented from becoming thicker than necessary.

The first metal film 6052 is formed by, for example, a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method, or a chemical vapor deposition method such as a CVD method, in addition to the plating method.

Since the main material of the second metal film 6054 is Au, the same effects as in the case of the first combination can be obtained. In addition, since the adhesion between Ni and Au is relatively good, there is an effect that problems such as interfacial peeling are less likely to occur.

- Fourth combination Cu and Au are mentioned as a fourth combination.

Since the main material of the first metal film 6052 is Cu, the affinity between the first wiring layer 605 and the adhesive 691 can be enhanced, and the adhesive force can be enhanced. As a result, peeling of the adhesive 691 is suppressed, and the reliability of the piezoelectric drive device 1 can be further enhanced.

In addition to Cu alone, the above-mentioned Cu also includes a Cu-based alloy containing 70% by mass or more of Cu. As long as Cu is contained within this range, the first metal film 6052 can exhibit the effects described above, so any element can be added as an additive or impurity. Among these, examples of additives include P, B, N, and the like.

Although the film thickness of the first metal film 6052 mainly made of Cu is not particularly limited, it is preferably 0.10 μm or more and 5.0 μm or less, more preferably 1.0 μm or more and 2.0 μm or less. If the film thickness is within this range, the effect of enhancing the affinity with the adhesive 691 can be sufficiently exhibited, and the first wiring layer 605 can be prevented from becoming thicker than necessary.

The first metal film 6052 is formed by, for example, a physical vapor deposition method such as a sputtering method or a vacuum vapor deposition method, or a chemical vapor deposition method such as a CVD method, in addition to the plating method.

Since the main material of the second metal film 6054 is Au, the same effects as in the case of the first combination can be obtained. In addition, since the adhesion between Cu and Au is relatively good, there is an effect that problems such as interfacial separation are less likely to occur.

Four combinations that can be satisfied by the main material of the first metal film 6052 and the main material of the second metal film 6054 have been described above. A film other than the metal film 6052 and the second metal film 6054 may be included.

For example, in the first wiring layer 605, the first metal film 6052 is closer to the first insulating film 63, for example, between the first metal film 6052 and the second metal film 6054, or between the second metal film 6054 and the second metal film 6054. Another film interposed between the first insulating film 63 may be provided.

Similarly, the second wiring layer 607 is provided with another film interposed between the second metal film 6054 and the third insulating film 65 , that is, between the second metal film 6054 and the third insulating film 65 . may be

As described above, the piezoelectric driving device 1 according to the present embodiment includes a first vibration plate 61a having a first surface 613a (first main surface) and an end surface 611 and a second surface 613b shown in FIGS. (second main surface), piezoelectric elements 60A to 60G (first piezoelectric elements), first metal film 6052, second metal film 6054, wiring board 8, and and a rotor 2 which is a driven body shown and driven by vibration of the piezoelectric elements 60A to 60F. The first diaphragm 61a is the diaphragm 61 of the first piezoelectric element unit 60a, and the second diaphragm 61b is the diaphragm 61 of the second piezoelectric element unit 60b.

Of these, the piezoelectric elements 60A to 60G (first piezoelectric elements) of the first piezoelectric element unit 60a are, as shown in FIGS. and is provided on the first surface 613a. That is, the piezoelectric elements 60A to 60G are provided between the first diaphragm 61a and the second diaphragm 61b.

Also, the piezoelectric elements 60A to 60G (second piezoelectric elements) of the second piezoelectric element unit 60b are provided on the second surface 613b, as shown in FIGS. The first piezoelectric element unit 60a and the second piezoelectric element unit 60b are bonded together with an adhesive 691 interposed therebetween.

Also, the first metal film 6052 of the first piezoelectric element unit 60a is provided between the electrode and the adhesive 691, as shown in FIG. Furthermore, as shown in FIG. 12, the second metal film 6054 of the first piezoelectric element unit 60a is provided between the electrode and the first metal film 6052 and on the end surface 611 of the first vibration plate 61a. It is electrically conductive. Also, the wiring substrate 8 is connected to the second metal film 6054 exposed on the end surface 611 via the conductive member 83 .

In the piezoelectric driving device 1 according to this embodiment, the combinations of the main material of the first metal film 6052 and the main material of the second metal film 6054 are the first combination, the second combination, and the third combination. Any one combination of the combination and the fourth combination is satisfied.

According to such a piezoelectric driving device 1, as shown in FIG. , the first metal film 6052 is exposed. Since the first metal film 6052 has an affinity for the adhesive 691 as described above, high adhesion can be obtained.

On the other hand, the piezoelectric drive device 1 according to this embodiment includes the conducting member 83 having conductivity as described above. is provided. The second metal film 6054 is exposed at the interface with the conduction member 83 .

Since the second metal film 6054 has a low contact resistance as described above, the electrical resistance between the second metal film 6054 and the wiring board 8 can be reduced. In this embodiment, the first wiring layers 605 and 606 to be bonded with the adhesive 691 employ a two-layer structure in which the first metal film 6052 is exposed, and are used to bond with the conductive member 83 . A structure in which the second metal film 6054 is exposed is adopted for the second wiring layer 607 . Therefore, it is possible to achieve both high adhesive strength and low electrical resistance. As described above, the piezoelectric driving device 1 with high reliability can be realized.

Also, by using the first metal film 6052 and the second metal film 6054 together, the above effect can be obtained without using a special substance or the like. Therefore, high reliability as described above can be achieved at low cost.

In FIG. 12, the piezoelectric element unit 60 and the wiring board 8 are adhered via an adhesive 693 in addition to the conductive member 83 . Thereby, the piezoelectric element unit 60 and the wiring board 8 can be connected more reliably. Further, even if the mechanical connection by the conductive member 83 is insufficient, it can be reinforced by the adhesive 693, so that the constituent material of the conductive member 83 can be selected so as to give priority to the electrical connection. Especially the resistance can be lowered.

Although the adhesive 693 is not particularly limited, it is appropriately selected from, for example, the adhesives 691 described above. Also, the adhesive 693 may be provided as necessary, and may be omitted.

Also, instead of the second piezoelectric element unit 60b, a single second diaphragm 61b may be provided. That is, the adhesive 691 may be configured to bond the second surface 613b and the first metal film 6052 together.

On the other hand, in the present embodiment, as described above, the first piezoelectric element unit 60a and the second piezoelectric element unit 60b having the same configuration are bonded together to form one stack unit. That is, piezoelectric elements 60A to 60G (second piezoelectric elements) are provided between the second diaphragm 61b and the adhesive 691, as shown in FIGS. In other words, this second piezoelectric element is provided between the second surface 613 b and the first metal film 6052 .

With such a configuration, the output can be increased compared to one piezoelectric element unit 60 . Thereby, for example, the piezoelectric driving device 1 that can be driven with high torque can be realized.

FIG. 13 is a sectional view showing a state in which a plurality of piezoelectric element units 60 shown in FIG. 10 are laminated and electrically connected to the wiring substrate 8. As shown in FIG.

A piezoelectric drive device 1 shown in FIG. 13 includes a plurality of stack units. Specifically, first, two piezoelectric element units 60 are laminated via an adhesive 691 to form one stack unit. Further, by bonding the stack units together via an adhesive 692, a stack structure in which the piezoelectric element units 60 are laminated in multiples of two is obtained. Moreover, each stack unit is electrically connected to the wiring board 8 via the conducting member 83 .

By providing a plurality of stack units in this way, it is possible to realize the piezoelectric drive device 1 capable of generating a particularly high output. In addition, since a plurality of stack units can be collectively connected to the wiring board 8 with a simple structure, the piezoelectric drive device 1 can achieve both high output and simplification.

Although the adhesive 692 is not particularly limited, it is appropriately selected from, for example, the adhesives 691 described above.

Examples of the first diaphragm 61a and the second diaphragm 61b include a silicon substrate, a silicon carbide substrate, a compound semiconductor substrate, and the like. Among them, the first diaphragm 61a or the second diaphragm 61b is preferably a silicon substrate. As a result, the silicon semiconductor manufacturing technology can be diverted to manufacture the first piezoelectric element unit 60a or the second piezoelectric element unit 60b. Therefore, the first piezoelectric element unit 60a or the second piezoelectric element unit 60b can be manufactured efficiently and with high precision.

The tip portion 44 is provided at the tip of the vibrating portion 41 and protrudes from the vibrating portion 41 toward the positive side in the Y-axis direction. The tip portion 44 is in contact with the outer peripheral surface 21 of the rotor 2 . Therefore, the vibration of the vibrating portion 41 is transmitted to the rotor 2 via the tip portion 44 . The constituent material of the tip portion 44 is not particularly limited, but examples include various ceramics such as zirconia, alumina, and titania. As a result, the distal end portion 44 has excellent durability.

14 is a diagram showing an example of alternating voltage applied to the vibrating portion shown in FIG. 3. FIG. 15 and 16 are plan views showing driving states of the vibrating section shown in FIG. 1, respectively. FIG. 17 is a cross-sectional view taken along line FF in FIG. 18 is a block diagram showing the control device of FIG. 1. FIG.

In such vibrating body 4, when alternating voltage V1 shown in FIG. 14 is applied to piezoelectric elements 6A and 6F, alternating voltage V2 is applied to piezoelectric elements 6C and 6D, and alternating voltage V3 is applied to piezoelectric elements 6B and 6E, As shown in FIG. 15, the vibrating portion 41 performs bending vibration in the Z-axis direction while stretching and vibrating in the Y-axis direction. At this time, the alternating voltage V2 applied to the piezoelectric elements 6C and 6D causes the vibrating portion 41 to generate stretching vibration. On the other hand, the alternating voltage V1 applied to the piezoelectric elements 6A and 6F and the alternating voltage V3 applied to the piezoelectric elements 6B and 6E cause the vibrating section 41 to generate bending vibration. Then, when these vibrations are synthesized, the tip of the tip portion 44 makes an elliptical motion drawing an elliptical orbit counterclockwise as indicated by the arrow A1. Therefore, the alternating voltages V1, V2 and V3 are the drive signal Sd in the vibration actuator 3. FIG. The rotor 2 is sent out by such an elliptical motion of the tip portion 44, and the rotor 2 rotates clockwise as indicated by an arrow B1. Also, in response to the vibration of the vibrating portion 41, a detection signal Ss is output from the piezoelectric element 6G.

In the elliptical motion of the tip portion 44 indicated by the arrow A1 in FIG. 15, the tip portion 44 contacts the outer peripheral surface 21 of the rotor 2 from the point A1′ to the point A1″ to send the rotor 2 in the direction of the arrow B1. , A1″ to A1′, the tip portion 44 is separated from the outer peripheral surface 21 of the rotor 2 . Therefore, from point A1″ to point A1′, the rotation of rotor 2 in the direction opposite to arrow B1 is suppressed.

When the alternating voltages V1 and V3 are switched to each other, that is, the alternating voltage V1 is applied to the piezoelectric elements 6B and 6E, the alternating voltage V2 is applied to the piezoelectric elements 6C and 6D, and the alternating voltage V3 is applied to the piezoelectric elements 6A and 6F. Then, as shown in FIG. 16, the vibrating portion 41 undergoes stretching vibration in the Y-axis direction and bending vibration in the Z-axis direction. Also at this time, the alternating voltage V2 applied to the piezoelectric elements 6C and 6D causes the vibrating portion 41 to generate stretching vibration. On the other hand, the alternating voltage V1 applied to the piezoelectric elements 6B and 6E and the alternating voltage V3 applied to the piezoelectric elements 6A and 6F cause the vibrating section 41 to generate bending vibration. When these vibrations are combined, the tip portion 44 makes an elliptical motion clockwise as indicated by arrow A2. The rotor 2 is sent out by such an elliptical motion of the tip portion 44, and the rotor 2 rotates counterclockwise as indicated by an arrow B2. Further, corresponding to such vibration of the vibrating portion 41, a detection signal Ss is output from the piezoelectric element 6G.

In the elliptical motion of the tip portion 44 indicated by the arrow A2 in FIG. 16, the tip portion 44 comes into contact with the outer peripheral surface 21 of the rotor 2 from the point A2' to the point A2'' and sends the rotor 2 in the direction of the arrow B2. , A2″ to A2′, the tip portion 44 is separated from the outer peripheral surface 21 of the rotor 2 . Therefore, from point A2″ to point A2′, rotation of the rotor 2 in the direction opposite to arrow B2 is suppressed.

As long as the rotor 2 can be rotated in at least one direction, the pattern of the alternating voltage applied to the piezoelectric elements 6A to 6F is not limited to the illustrated pattern. The voltage applied to the piezoelectric elements 6A to 6F may be, for example, a DC voltage applied intermittently instead of the alternating voltage.

As described above, the piezoelectric drive device 1 according to the present embodiment further includes the distal end portion 44 (contact portion) that makes an elliptical motion due to the vibration of the piezoelectric elements 6A to 6F (first piezoelectric elements). The tip portion 44 is provided on the side opposite to the wiring substrate 8 of the first diaphragm 61a. The elliptical motion of the tip portion 44 drives the rotor 2 as a driven body.

Such elliptical motion is motion based on vibration in a plane parallel to the interface between the piezoelectric body 602 and the first electrode 601 , that is, the surface of the first electrode 601 . Vibration in such a plane is highly efficient vibration in the vibrating section 41 . Therefore, by driving the rotor 2 based on such vibration, it is possible to contribute to the reduction of the power consumption of the piezoelectric drive device 1 .

In addition, the term “parallel” in this specification means that the angle formed by the plane of stretching vibration and bending vibration and the surface of the first electrode 601 is 0°, and the angle is within the range of ±5°. It is a concept that refers to a state in

Further, by providing the tip portion 44 on the opposite side of the wiring board 8 of the first diaphragm 61a, it is possible to prevent the wiring board 8 and the rotor 2 from interfering with each other. Therefore, it is possible to increase the degree of freedom in arranging the wiring board 8, and realize the piezoelectric driving device 1 that is excellent in ease of assembly and space saving.

Note that the distal end portion 44 may be provided as necessary, and may be replaced by other members.

The biasing member 5 is a member that biases the tip portion 44 toward the outer peripheral surface 21 of the rotor 2 . The biasing member 5 has a first substrate 51 located on the X-axis plus side of the vibrating body 4 and a second substrate 52 located on the X-axis minus side of the vibrating body 4, as shown in FIG. The vibrating body 4 is sandwiched between the first substrate 51 and the second substrate 52 . The first substrate 51 and the second substrate 52 are not particularly limited, but for example, silicon substrates can be used.

Further, as shown in FIG. 17, a spacer 53 having the same thickness as the vibrating body 4 is provided between the first substrate 51 and the second substrate 52 . In addition, a through hole 59 is formed through the portion in the X-axis direction, and the biasing member 5 is screwed to the housing or the like using the through hole 59 . By fixing the biasing member 5 to the housing or the like with the spring portion 513 shown in FIG. It can be biased toward surface 21 .

The configuration of the biasing member 5 is not particularly limited as long as it can bias the distal end portion 44 toward the outer peripheral surface 21 of the rotor 2 . For example, either one of the first substrate 51 and the second substrate 52 may be omitted. Also, for example, a coil spring, a leaf spring, or the like may be used as the biasing member 5 .

The control device 7 controls the driving of the rotor 2 by the vibrator 4 by appropriately adjusting the alternating voltages V1, V2, and V3 applied to the piezoelectric elements 6A to 6F.

As shown in FIG. 18, the control device 7 includes a drive pulse signal generator 71 that generates a drive pulse signal Pd, and drive signals that are applied from the drive pulse signal Pd to the piezoelectric elements 6A, 6B, 6C, 6D, 6E, and 6F. Sd, a detection pulse signal generator 73 that binarizes the detection signal Ss output from the piezoelectric element 6G to generate the detection pulse signal Ps, the drive pulse signal Pd and the detection pulse signal Ps and a drive controller 75 that controls driving of the drive pulse signal generator 71 based on the phase difference.

The drive pulse signal generator 71 is a circuit that generates a drive pulse signal Pd for generating the drive signal Sd. As shown in FIG. 18, the drive pulse signal Pd generated by the drive pulse signal generator 71 is a rectangular wave binarized to High/Low. The drive pulse signal generator 71 can change the duty of the drive pulse signal Pd. By changing the duty of the drive pulse signal Pd, the amplitude of the drive signal Sd can be changed. For example, if the duty is 50%, the amplitude of the drive signal Sd becomes maximum, and the amplitude of the drive signal Sd decreases as the duty approaches 0%.

The configuration of the drive pulse signal generation unit 71 is not particularly limited as long as it can generate the drive pulse signal Pd described above and change the duty of the drive pulse signal Pd. As shown in FIG. 18, the drive pulse signal generator 71 according to the present embodiment has an electrode 71A having a GND potential, an electrode 71B having a +VDD potential, and a switching element 71C. The drive pulse signal Pd is generated by alternately switching between a state in which the electrode 71A and the switching element 71C are connected and a state in which the electrode 71B and the switching element 71C are connected. there is Further, in the present embodiment, the drive pulse signal generator 71 generates three different drive signals, for example, alternating voltages V1, V2, and V3 and signals with different phases, so that the first drive pulse signal generator 711 , a second drive pulse signal generator 712 and a third drive pulse signal generator 713 .

The drive signal generator 72 is a circuit that generates the drive signal Sd, which is an analog signal, from the drive pulse signal Pd generated by the drive pulse signal generator 71 . As shown in FIG. 18, the drive signal Sd generated by the drive signal generator 72 is a substantially sinusoidal signal.

The configuration of the drive signal generator 72 is not particularly limited as long as it can generate the drive signal Sd described above. As shown in FIG. 18, the drive signal generator 72 according to this embodiment mainly includes a buffer 72A and a coil 72B. Further, in the present embodiment, the drive signal generator 72 generates three different drive signals, for example, alternating voltages V1, V2, and V3 and signals with different phases, so that the first drive pulse signal generator 711 , a second drive signal generator 722 connected to the second drive pulse signal generator 712, and a third drive signal generator 713 connected to and a generation unit 723 .

By applying the three drive signals generated by the drive signal generation unit 72, here alternating voltages V1, V2, and V3, to the piezoelectric elements 6A, 6B, 6C, 6D, 6E, and 6F, as described above, the vibrating body 4 vibrates and the rotor 2 rotates accordingly.

The detection pulse signal generator 73 is a circuit that binarizes the detection signal Ss, which is an analog signal, output from the piezoelectric element 6G with the vibration of the vibrating body 4, and generates a detection pulse signal Ps, which is a digital signal. . As shown in FIG. 18, the detection signal Ss output from the piezoelectric element 6G is a substantially sinusoidal signal corresponding to the amplitude of the vibrating body 4, and the detection pulse signal Ps changes the detection signal Ss between High and Low. It is a quantified rectangular wave signal. The configuration of the detection pulse signal generator 73 is not particularly limited as long as it can generate the detection pulse signal Ps described above.

The phase difference acquisition section 74 is a circuit that acquires the phase difference between the drive pulse signal Pd and the detection pulse signal Ps. By acquiring the phase difference in this way, the vibration state of the vibrating body 4 can be monitored.

The drive control section 75 is a circuit that controls driving of the drive pulse signal generation section 71 based on the phase difference acquired by the phase difference acquisition section 74 . The drive control unit 75 changes the frequency of each drive pulse signal Pd as needed, for example, so that the phase difference tracks a predetermined value. Since there is a correlation between the amplitude of the vibrating body 4 and the phase difference, the rotor 2 can be rotated at a higher speed by adjusting the phase difference to a value that maximizes the amplitude of the vibrating body 4 .
As described above, the driving of the rotor 2 by the vibrating body 4 can be controlled.

The control device 7 is composed of a computer having a processor such as a CPU, a memory, an interface, and the like. The operation of each section is controlled by executing a predetermined program stored in the memory by the processor. Note that the program may be downloaded from the outside via an interface. Alternatively, all or part of the configuration of the control device 7 may be provided outside the piezoelectric drive device 1 and connected via a communication network such as a LAN (Local Area Network).

<Second embodiment>
Next, a piezoelectric drive device according to a second embodiment will be described.
FIG. 19 is a cross-sectional view showing part of the piezoelectric driving device according to the second embodiment.

The second embodiment will be described below. In the following description, differences from the above-described embodiment will be mainly described, and descriptions of the same items will be omitted. Moreover, in FIG. 19, the same code|symbol is attached|subjected about the structure similar to the said embodiment.

The second embodiment is the same as the first embodiment except that the conducting member 83 is omitted.
That is, in the piezoelectric driving device 1 shown in FIG. 19, the second metal film 6054 and the wiring board 8 are electrically connected without using the conducting member 83 . In other words, the contact between the second metal film 6054 and the wiring substrate 8 establishes electrical continuity.

Also in such a second embodiment, the same effect as in the first embodiment can be obtained. That is, the second metal film 6054 is characterized by low contact resistance because its main material satisfies the combination described above. Therefore, even when the wiring substrate 8 is brought into contact without the conducting member 83, the electrical resistance between the second metal film 6054 and the wiring substrate 8 can be reduced. As a result, it is possible to obtain a highly reliable piezoelectric driving device 1 in which wasteful power consumption is suppressed.

<Third Embodiment>
Next, a method for manufacturing the piezoelectric driving device according to the third embodiment will be described.

20A to 20C are process diagrams showing a method of manufacturing the piezoelectric driving device according to the third embodiment. 21 to 23 are diagrams for explaining the method of manufacturing the piezoelectric driving device according to the third embodiment.

The third embodiment will be described below, but in the following description, the points of difference from the above-described embodiment will be mainly described, and the description of the same items will be omitted. In addition, in FIGS. 20 to 23, the same reference numerals are assigned to the same configurations as in the above-described embodiment.

Here, as a method of manufacturing the piezoelectric driving device according to the third embodiment, a method of manufacturing the piezoelectric driving device 1 shown in FIGS. 6 to 12 will be described as an example.

This manufacturing method includes, as shown in FIG. 20, a member preparation step S1, an adhesion step S2, an etching step S3, a conduction step S4, and an assembly step S5. Each step will be described below in sequence.

[1] Member preparation step S1
First, the necessary first member 600a is prepared. As shown in FIG. 21, the first member 600a is provided with a first diaphragm 61a having a first surface 613a (first main surface) and an end surface 611, and on the first surface 613a and the end surface 611. A first metal film 6052, a second metal film 6054 provided between the first surface 613a and the first metal film 6052 and between the end surface 611 and the first metal film 6052, and a first diaphragm and piezoelectric elements 60A to 60G (first piezoelectric elements) provided between 61a and the second metal film 6054.

Note that the main material of the first metal film 6052 and the main material of the second metal film 6054 are the first combination, the second combination, the third combination, and the fourth combination described above. selected to satisfy any one combination of

[2] Bonding step S2
Next, the second member 600b is prepared. This second member 600b is the same as the first member 600a except that it has a second diaphragm 61b instead of the first diaphragm 61a. That is, as shown in FIG. 22, the second member 600b includes a second vibration plate 61b having a second surface 613b (second main surface), a first metal film 6052, a second metal film 6054, and a piezoelectric element. 60A to 60G.

Next, an adhesive 691 is interposed between the first surface 613a and the second surface 613b, more specifically, between the adhesive surface of the first member 600a and the adhesive surface of the second member 600b, as shown in FIG. As shown, the first member 600a and the second member 600b are glued together. At this time, the adhesive 691 is provided between the first surface 613 a and the second surface 613 b, but is not provided on the end surface 611 .

[3] Etching step S3
Next, the first member 600a and the second member 600b that are adhered to each other are subjected to an etching process. For example, wet etching or dry etching is used for this etching process. Among these, wet etching is preferably used. Specifically, an etchant that dissolves the first metal film 6052 but does not dissolve the second metal film 6054 is used. As a result, as shown in FIG. 23, the first metal film 6052 exposed from the adhesive 691 and located on the end face 611 is dissolved, leaving the second metal film 6054 at that portion. Then, part of the second metal film 6054 is exposed.

Such an etchant is appropriately selected according to the magnitude relationship between the solubility of the main material of the first metal film 6052 and the solubility of the main material of the second metal film 6054 .

Thus, the portion of the first metal film 6052 located on the end surface 611 is removed by etching. Thereby, the first metal film 6052 located on the end surface can be efficiently and selectively removed. That is, since the portion of the first metal film 6052 located on the first surface 613a is covered with the adhesive 691, it is hardly removed even if it is subjected to the etching process. On the other hand, the portion of the first metal film 6052 located on the end face 611 is not covered with the adhesive 691 and can be easily removed.

[4] Continuity process S4
Next, a wiring board 8 is prepared. Then, the exposed portion of the second metal film 6054 and the wiring board 8 are joined together via the conductive member 83 as shown in FIG. Thereby, the second metal film 6054 and the conducting member 83 can be electrically connected.

As described above, the first metal film 6052 can be firmly adhered by the adhesive 691, and the second metal film 6054 can be electrically connected by the conductive member 83 while suppressing the contact resistance.

[5] Assembly process S5
Next, the tip portion 44, the biasing member 5, and the like are assembled to the piezoelectric element unit 60, and the rotor 2 is assembled. The piezoelectric driving device 1 is obtained as described above.

As described above, the method for manufacturing the piezoelectric drive device 1 according to the present embodiment includes the first vibration plate 61a having the first surface 613a (first main surface) and the end surface 611, the first surface 613a and the end surface 611. A first metal film 6052 provided, a second metal film 6054 provided between the first surface 613a and the first metal film 6052, and between the end surface 611 and the first metal film 6052, and a second A first member 600a, which is a first piezoelectric element unit including piezoelectric elements 60A to 60G (first piezoelectric elements) provided between one vibration plate 61a and a second metal film 6054, and a second surface 613b ( a second member 600b, which is a second piezoelectric element unit including a second diaphragm 61b having a second main surface) and piezoelectric elements 60A to 60G (second piezoelectric elements) provided on the second diaphragm 61b; , and interposing an adhesive 691 between the first member 600a and the second member 600b to bond the first member 600a and the second member 600b; A step S3 of removing a portion located on the end face 611 to expose a portion of the second metal film 6054, and a step of preparing the wiring substrate 8 and connecting a portion of the second metal film 6054 and the wiring substrate 8. and S4. The combination of the main material of the first metal film 6052 and the main material of the second metal film 6054 is one of the first combination, the second combination, the third combination, and the fourth combination described above. satisfy any combination.

According to such a manufacturing method, the first metal film 6052 can be used for bonding with the adhesive 691 and the second metal film 6054 can be used for bonding with the conductive member 83 . As a result, the affinity between the first metal film 6052 and the adhesive 691 can be used to obtain a high adhesive force, and the low contact resistance of the second metal film 6054 can reduce the electrical resistance between the wiring substrate 8 and the wiring substrate 8 . can. As a result, the piezoelectric drive device 1 having high mechanical and electrical reliability can be manufactured at low cost.

<Fourth Embodiment>
FIG. 24 is a perspective view showing the robot according to the fourth embodiment.

A robot 1000 shown in FIG. 24 can perform operations such as material supply, material removal, transportation, and assembly of precision equipment and its component parts. The robot 1000 is a six-axis robot, and includes a base 1010 fixed to the floor or ceiling, an arm 1020 rotatably connected to the base 1010, an arm 1030 rotatably connected to the arm 1020, and an arm 1030 arm 1040 rotatably connected to arm 1040, arm 1050 rotatably connected to arm 1040, arm 1060 rotatably connected to arm 1050, and arm 1060 rotatably connected to It has an arm 1070 and a control device 1080 that controls the driving of these arms 1020 , 1030 , 1040 , 1050 , 1060 and 1070 .

Further, the arm 1070 is provided with a hand connecting portion, and an end effector 1090 corresponding to the work to be executed by the robot 1000 is attached to the hand connecting portion. A piezoelectric drive device 1 is mounted on all or part of each joint, and the arms 1020, 1030, 1040, 1050, 1060, and 1070 are rotated by driving the piezoelectric drive device 1. FIG. Note that the piezoelectric drive device 1 may be mounted on the end effector 1090 and used to drive the end effector 1090 .

The control device 1080 is composed of a computer and has, for example, a processor such as a CPU, a memory, an interface, and the like. Then, the processor controls the driving of each part of the robot 1000 by executing a predetermined program stored in the memory. The program may be downloaded from an external server via an interface. All or part of the configuration of the control device 1080 may be provided outside the robot 1000 and connected via a communication network such as a LAN (local area network).

Such a robot 1000 includes the piezoelectric drive device 1 as described above.
That is, the robot 1000 includes a first diaphragm 61a having a first surface 613a (first principal surface) and an end surface 611, a second diaphragm 61b having a second surface 613b (second principal surface), and a piezoelectric element 60A. 60G, a first metal film 6052, a second metal film 6054, a wiring board 8, and a rotor 2 (driven body) driven by vibration of the piezoelectric elements 60A to 60F. I have.

The piezoelectric elements 60A to 60G of the first piezoelectric element unit 60a have electrodes such as a first electrode 601, a second electrode 603 and a third electrode 604, and have a first surface 613a and a second surface 613b. is provided between Also, the first metal film 6052 of the first piezoelectric element unit 60a is provided between the electrode and the second surface 613b. Furthermore, the second metal film 6054 of the first piezoelectric element unit 60a is provided between the electrode and the first metal film 6052 and on the end face 611 of the first vibration plate 61a, and is electrically conductive. have. Also, the wiring substrate 8 is connected to the second metal film 6054 exposed on the end surface 611 via the conductive member 83 . Furthermore, the combination of the main material of the first metal film 6052 and the main material of the second metal film 6054 is one of the first combination, the second combination, the third combination, and the fourth combination described above. Satisfies any one combination.

In such a piezoelectric driving device 1, the affinity between the first metal film 6052 and the adhesive 691 is used to obtain a high adhesive force, and the low contact resistance of the second metal film 6054 allows the connection between the piezoelectric driving device 1 and the wiring substrate 8 to be improved. Electric resistance can be lowered. As a result, the robot 1000 including the piezoelectric drive device 1 having high mechanical and electrical reliability can be realized at low cost.

Although the piezoelectric drive device, the method for manufacturing the piezoelectric drive device, and the robot according to the present invention have been described above based on the illustrated embodiments, the present invention is not limited to these, and the configuration of each part of the above-described embodiments is as follows. , can be replaced with any configuration having similar functions. Also, in the above embodiments, other optional components may be added. Further, the method for manufacturing the piezoelectric driving device according to the embodiment may be added with an arbitrary step. Further, each embodiment may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1... Piezoelectric driving device 2... Rotor 3... Vibration actuator 4... Vibrating body 5... Biasing member 6A... Piezoelectric element 6B... Piezoelectric element 6C... Piezoelectric element 6D... Piezoelectric element 6E... Piezoelectric element , 6F... Piezoelectric element, 6G... Piezoelectric element, 7... Control device, 8... Wiring board, 9... Encoder, 21... Peripheral surface, 22... Main surface, 41... Vibration part, 42... Support part, 43... Connection part, 44... Tip part 51... First substrate 52... Second substrate 53... Spacer 59... Through hole 60... Piezoelectric element unit 60A... Piezoelectric element 60B... Piezoelectric element 60C... Piezoelectric element 60D... Piezoelectric element 60E Piezoelectric element 60F Piezoelectric element 60G Piezoelectric element 60a First piezoelectric element unit 60b Second piezoelectric element unit 61 Diaphragm 61a First diaphragm 61b Second Diaphragm 63 First insulating film 64 Second insulating film 65 Third insulating film 68 Spacer structure 71 Drive pulse signal generator 71A Electrode 71B Electrode 71C Switching element 72 drive signal generation unit 72A buffer 72B coil 73 detection pulse signal generation unit 74 phase difference acquisition unit 75 drive control unit 81 flexible substrate 82 wiring 83 conduction member DESCRIPTION OF SYMBOLS 91... Scale 92... Optical element 513... Spring part 600a... First member 600b... Second member 601... First electrode 602... Piezoelectric body 603... Second electrode 604... Third electrode 605 First wiring layer 606 First wiring layer 607 Second wiring layer 611 End face 613a First surface 613b Second surface 615 First back surface 633 Surface 651 Surface 691 Adhesive 692 Adhesive 693 Adhesive 711 First drive pulse signal generator 712 Second drive pulse signal generator 713 Third drive pulse signal generator 721 First drive Signal generator 722 Second drive signal generator 723 Third drive signal generator 921 Light emitting device 922 Imaging device 1000 Robot 1010 Base 1020 Arm 1030 Arm 1040 Arm 1050 Arm 1060 Arm 1070 Arm 1080 Control device 1090 End effector 6021 Surface 6022 Surface 6052 First metal film 6054 Second metal film A1 Arrow A2... arrow, B1... arrow, B2... arrow, O... central axis, Pd... drive pulse signal, Ps... detection pulse signal, S1... process, S2... process, S3... process, S4... process, S5... process, Sd ... drive signal, Ss ... detection signal

Claims (15)

a first piezoelectric element unit having a first diaphragm and a first piezoelectric element having an electrode and provided on the first diaphragm;
a second piezoelectric element unit having a second diaphragm and a second piezoelectric element provided on the second diaphragm;
The first piezoelectric element unit and the second piezoelectric element unit are bonded such that the first piezoelectric element and the second piezoelectric element are positioned between the first diaphragm and the second diaphragm. an adhesive;
a first metal film provided between the electrode and the adhesive;
a conductive second metal film provided between the electrode and the first metal film and on an end surface of the first diaphragm;
a wiring substrate electrically connected to the second metal film;
a driven body driven by the vibration of the first piezoelectric element and the vibration of the second piezoelectric element;
with
The adhesive is an epoxy adhesive, a silicone adhesive, a urethane adhesive or an acrylic adhesive,
a combination in which the main material of the first metal film is TiW and the main material of the second metal film is Ni ;
A piezoelectric drive device characterized by satisfying : a first piezoelectric element unit having a first diaphragm and a first piezoelectric element having an electrode and provided on the first diaphragm;
a second piezoelectric element unit having a second diaphragm and a second piezoelectric element provided on the second diaphragm;
The first piezoelectric element unit and the second piezoelectric element unit are bonded such that the first piezoelectric element and the second piezoelectric element are positioned between the first diaphragm and the second diaphragm. an adhesive;
a first metal film provided between the electrode and the adhesive;
a conductive second metal film provided between the electrode and the first metal film and on an end surface of the first diaphragm;
a wiring substrate electrically connected to the second metal film;
a driven body driven by the vibration of the first piezoelectric element and the vibration of the second piezoelectric element;
with
The adhesive is an epoxy adhesive, a silicone adhesive, a urethane adhesive or an acrylic adhesive,
a combination in which the main material of the first metal film is TiW and the main material of the second metal film is Au ;
a combination in which the main material of the first metal film is Ni and the main material of the second metal film is Au; and
a combination in which the main material of the first metal film is Cu and the main material of the second metal film is Au;
A piezoelectric drive device characterized by satisfying any combination of The first diaphragm and the second diaphragm are bonded to the wiring board via an adhesive other than the adhesive,
3. The piezoelectric drive device according to claim 1, wherein said another adhesive is epoxy adhesive, silicone adhesive, urethane adhesive or acrylic adhesive. The first diaphragm and the second diaphragm each have a main surface and the end surface,
An insulating film provided so as to extend from the main surface to the end surface,
4. The piezoelectric driving device according to claim 3, wherein said another adhesive adheres said insulating film provided on said end surface and said wiring board. 5. A contact part provided on the opposite side of the first diaphragm from the wiring board, and for driving the driven body by elliptical motion caused by vibration of the first piezoelectric element. 2. The piezoelectric driving device according to item 1 . 6. The piezoelectric drive device according to claim 1, wherein said wiring substrate includes a flexible substrate. 7. The piezoelectric driving device according to claim 1, wherein said first diaphragm or said second diaphragm is a silicon substrate. The first piezoelectric element has a piezoelectric body in contact with the electrode,
The piezoelectric drive device according to any one of claims 1 to 7 , wherein the piezoelectric body is a sol-gel film. 9. The piezoelectric driving device according to claim 1, further comprising a conductive member provided between said second metal film and said wiring substrate and having electrical conductivity. a first diaphragm;
a second diaphragm;
a first piezoelectric element having an electrode and provided between the first diaphragm and the second diaphragm;
a first metal film provided between the electrode and the second diaphragm;
a conductive second metal film provided between the electrode and the first metal film and on an end surface of the first diaphragm;
an adhesive bonding the second diaphragm and the first metal film;
a wiring substrate electrically connected to the second metal film;
a driven body driven by vibration of the first piezoelectric element;
with
The adhesive is an epoxy adhesive, a silicone adhesive, a urethane adhesive or an acrylic adhesive,
a combination in which the main material of the first metal film is TiW and the main material of the second metal film is Ni ;
A piezoelectric drive device characterized by satisfying : a first diaphragm;
a second diaphragm;
a first piezoelectric element having an electrode and provided between the first diaphragm and the second diaphragm;
a first metal film provided between the electrode and the second diaphragm;
a conductive second metal film provided between the electrode and the first metal film and on an end surface of the first diaphragm;
an adhesive bonding the second diaphragm and the first metal film;
a wiring substrate electrically connected to the second metal film;
a driven body driven by vibration of the first piezoelectric element;
with
The adhesive is an epoxy adhesive, a silicone adhesive, a urethane adhesive or an acrylic adhesive,
a combination in which the main material of the first metal film is TiW and the main material of the second metal film is Au ;
a combination in which the main material of the first metal film is Ni and the main material of the second metal film is Au; and
a combination in which the main material of the first metal film is Cu and the main material of the second metal film is Au;
A piezoelectric drive device characterized by satisfying any combination of 12. The piezoelectric driving device according to claim 10, further comprising a second piezoelectric element provided between said second diaphragm and said adhesive. a first diaphragm, a first metal film provided on the first main surface and the end surface of the first diaphragm, between the first main surface and the first metal film and between the end surface and the first metal film; a first piezoelectric element unit having a second metal film provided between the metal film and a first piezoelectric element having an electrode and provided on the first vibration plate; a second vibration plate; and a second piezoelectric element unit having a second piezoelectric element provided on the second vibration plate, an adhesive is interposed between the first piezoelectric element and the second piezoelectric element, and the first bonding the piezoelectric element unit and the second piezoelectric element unit;
removing a portion of the first metal film located on the end surface to expose a portion of the second metal film;
connecting a portion of the second metal film and a wiring substrate;
including
a first combination in which the main material of the first metal film is TiW and the main material of the second metal film is Au;
a second combination in which the main material of the first metal film is TiW and the main material of the second metal film is Ni;
a third combination in which the main material of the first metal film is Ni and the main material of the second metal film is Au; and
A fourth combination in which the main material of the first metal film is Cu and the main material of the second metal film is Au;
A method of manufacturing a piezoelectric driving device, characterized by satisfying any combination of 14. The method of manufacturing a piezoelectric driving device according to claim 13 , wherein said portion of said first metal film is removed by etching. A piezoelectric drive device according to any one of claims 1 to 12 ;
and an arm rotated by the piezoelectric drive device.

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