JP2017069998A - Piezoelectric drive device, manufacturing method for the same, motor, robot and pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric drive device capable of achieving high output.SOLUTION: A piezoelectric drive device 100 includes: a silicon substrate 10 having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction; piezoelectric elements 30 being provided on the silicon substrate 10 and having first electrodes 32, second electrodes 36 and piezoelectric substances 34 positioned among the first electrodes 32 and the second electrodes 36; and a protrusion portion 40 being provided at a leading end 12 in the longitudinal direction and brought into contact with a driven body 2. A Young's modulus in the transverse direction of the silicon substrate 10 is smaller than a Young's modulus in the longitudinal direction of the silicon substrate 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a piezoelectric drive device and a manufacturing method thereof, a motor, a robot, and a pump.

  A piezoelectric actuator (piezoelectric drive device) that drives a driven body by vibrating a piezoelectric body is used in various fields because a magnet and a coil are not required (see, for example, Patent Document 1). In general, such a piezoelectric drive device uses a piezoelectric element (bulk piezoelectric element) including a bulk piezoelectric body (see, for example, Patent Document 2).

  On the other hand, as a piezoelectric element, a thin film piezoelectric element (thin film piezoelectric element) is known. Thin film piezoelectric elements are mainly used for ejecting ink in the heads of ink jet printers.

JP 2004-320979 A JP 2008-227123 A

  If the thin film piezoelectric element as described above is used in a piezoelectric driving device, the piezoelectric driving device and the device driven by the piezoelectric driving device can be reduced in size. However, the piezoelectric drive device using such a thin film piezoelectric element is small in size, and therefore, the output may be insufficient.

  One of the objects according to some aspects of the present invention is to provide a piezoelectric driving device capable of achieving high output. Another object of some aspects of the present invention is to provide a method of manufacturing a piezoelectric driving device capable of achieving high output. Another object of some embodiments of the present invention is to provide a motor, a robot, and a pump including the above-described piezoelectric driving device.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the piezoelectric drive device according to the present invention is:
A silicon substrate having a longitudinal direction and a transverse direction orthogonal to the longitudinal direction;
A piezoelectric element provided on the silicon substrate and having a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode;
A protrusion provided at the distal end in the longitudinal direction and in contact with the driven body;
Including
The Young's modulus in the short direction of the silicon substrate is smaller than the Young's modulus in the longitudinal direction of the silicon substrate.

In such a piezoelectric driving device, the amplitude of the bending vibration along the short direction of the silicon substrate can be increased by setting the direction in which the Young's modulus of the silicon substrate is small to the short direction instead of the long direction, High output can be achieved.

[Application Example 2]
In application example 1,
The silicon substrate may be a {110} substrate.

  In such a piezoelectric driving device, the Young's modulus in two directions orthogonal to each other in the plane of the silicon substrate can be made different.

[Application Example 3]
In application example 2,
The longitudinal direction of the silicon substrate is a <110> direction,
The short side direction of the silicon substrate may be a <100> direction.

  In such a piezoelectric drive device, high output can be achieved.

[Application Example 4]
In application example 2,
The longitudinal direction of the silicon substrate is a <111> direction,
The short side direction of the silicon substrate may be a <112> direction.

  In such a piezoelectric drive device, high output can be achieved.

[Application Example 5]
In any one of Application Examples 1 to 4,
The piezoelectric body may have a thickness of 50 nm to 20 μm.

  In such a piezoelectric drive device, high output can be achieved while preventing dielectric breakdown of the piezoelectric body.

[Application Example 6]
One aspect of a method for manufacturing a piezoelectric drive device according to the present invention is as follows.
Preparing silicon wafers having different Young's moduli in two directions perpendicular to each other in a plane;
Forming a piezoelectric element having a first electrode, a second electrode, and a piezoelectric body located between the first electrode and the second electrode on the silicon wafer;
Processing the silicon wafer to take out a chip having a silicon substrate having a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, and the piezoelectric element formed on the silicon substrate;
Attaching a protrusion contacting the driven body to the tip in the longitudinal direction of the chip;
Including
The chips are arranged in the silicon wafer such that the Young's modulus in the short direction of the silicon substrate is smaller than the Young's modulus in the longitudinal direction of the silicon substrate.

  In such a method for manufacturing a piezoelectric driving device, a piezoelectric driving device capable of achieving high output can be manufactured.

[Application Example 7]
In Application Example 6,
The silicon substrate may be a {110} substrate.

  In such a method for manufacturing a piezoelectric driving device, the Young's moduli in two directions orthogonal to each other in the plane of the silicon substrate can be made different.

[Application Example 8]
In Application Example 7,
The longitudinal direction of the silicon substrate is a <110> direction,
The short side direction of the silicon substrate may be a <100> direction.

  In such a method for manufacturing a piezoelectric driving device, a piezoelectric driving device capable of achieving high output can be manufactured.

[Application Example 9]
In Application Example 7,
The longitudinal direction of the silicon substrate is a <111> direction,
The short side direction of the silicon substrate may be a <112> direction.

  In such a method for manufacturing a piezoelectric driving device, a piezoelectric driving device capable of achieving high output can be manufactured.

[Application Example 10]
In any one of Application Examples 6 to 9,
The piezoelectric body may have a thickness of 50 nm to 20 μm.

  With such a method for manufacturing a piezoelectric drive device, it is possible to manufacture a piezoelectric drive device that can achieve high output while suppressing the occurrence of cracks in the piezoelectric body.

[Application Example 11]
One aspect of the motor according to the present invention is:
The piezoelectric drive device according to any one of Application Examples 1 to 5, and
A rotor rotated by the piezoelectric drive device;
including.

  Since such a motor includes the piezoelectric drive device according to the present invention, high output can be achieved.

[Application Example 12]
One aspect of the robot according to the present invention is:
A plurality of link parts;
A joint part connecting a plurality of the link parts;
The piezoelectric drive device according to any one of Application Examples 1 to 5 in which a plurality of the link portions are rotated by the joint portions;
including.

  Such a robot can include the piezoelectric driving device according to the present invention.

[Application Example 13]
One aspect of the robot according to the present invention is:
The piezoelectric drive device according to any one of Application Examples 1 to 5, and
A tube that transports the liquid;
A plurality of fingers for closing the tube by driving the piezoelectric driving device;
including.

  Such a pump can include a piezoelectric drive according to the present invention.

The top view which shows typically the piezoelectric drive device which concerns on this embodiment. 1 is a cross-sectional view schematically showing a piezoelectric drive device according to an embodiment. The top view which shows typically the piezoelectric drive device which concerns on this embodiment. The top view for demonstrating the longitudinal direction and transversal direction of a silicon substrate. The top view for demonstrating the longitudinal direction and transversal direction of a silicon substrate. The figure for demonstrating the electrical connection state of the piezoelectric drive device and drive circuit which concern on this embodiment. The figure for demonstrating operation | movement of the piezoelectric drive device which concerns on this embodiment. The flowchart for demonstrating the manufacturing method of the piezoelectric drive device which concerns on this embodiment. The top view which shows typically the manufacturing process of the piezoelectric drive device which concerns on this embodiment. The table | surface which shows the basic constant of the silicon | silicone used when calculating the Young's modulus. In-plane distribution of Young's modulus in a silicon (110) wafer. In-plane distribution of Young's modulus in a silicon (110) wafer. The figure for demonstrating the robot which concerns on this embodiment. The figure for demonstrating the wrist part of the robot which concerns on this embodiment. The figure for demonstrating the pump which concerns on this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. Piezoelectric Drive Device First, a piezoelectric drive device according to the present embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing a piezoelectric driving device 100 according to this embodiment. 2 is a cross-sectional view taken along the line II-II of FIG. 1 schematically showing the piezoelectric driving device 100 according to the present embodiment. FIG. 3 is a plan view schematically showing the piezoelectric driving device 100 according to the present embodiment.

  As shown in FIGS. 1 to 3, the piezoelectric driving device 100 includes a silicon substrate 10, a mounting portion 20, a piezoelectric element 30, and a protruding portion 40. The piezoelectric driving device 100 and the rotor (driven body) 2 constitute a motor 101. The rotor 2 is rotated by the piezoelectric driving device 100. For convenience, illustration of members of the rotor 2 and the piezoelectric element 30 is omitted in FIG. 3.

  The silicon substrate 10 is, for example, a {110} substrate. The silicon substrate 10 is, for example, a substrate cut out on the {110} plane. Here, {110} represents a plane equivalent to (110). Therefore, the silicon substrate 10 may be, for example, a (110) substrate, a (−110) substrate, or a (−1-10) substrate. In the present specification, “1 bar” and “2 bar” in the negative plane orientation or negative direction of the unit cell are respectively expressed as “−1” and “−2”.

  As shown in FIGS. 1 and 3, the silicon substrate 10 has a shape having a longitudinal direction and a short direction perpendicular to the longitudinal direction. In the illustrated example, the planar shape of the silicon substrate 10 is a rectangle. The longitudinal direction is the direction in which the long side extends, and the short side direction is the direction in which the short side extends.

  As shown in FIGS. 1 and 3, the attachment portions 20 are provided on the silicon substrate 10 via, for example, three connection portions 22 that extend from the long side of the silicon substrate 10 in plan view. The material of the attachment portion 20 and the connection portion 22 may be the same material as that of the silicon substrate 10. The attachment part 20 and the connection part 22 may be provided integrally with the silicon substrate 10 as shown in FIG. The attachment portion 20 is used for attaching the piezoelectric driving device 100 to another member with a screw 24.

  The piezoelectric element 30 is provided on the silicon substrate 10. Although not shown, the piezoelectric element 30 may be formed on the silicon substrate 10 via, for example, an adhesion layer that improves the adhesion between the piezoelectric element 30 and the silicon substrate 10. The silicon substrate 10, the attachment part 20, the connection part 22, and the piezoelectric element 30 constitute a chip 110. As illustrated in FIG. 2, the piezoelectric element 30 includes a first electrode 32, a piezoelectric body 34, and a second electrode 36.

  The first electrode 32 is provided on the silicon substrate 10. In the example illustrated in FIG. 1, the planar shape of the first electrode 32 is a rectangle. The first electrode 32 may be constituted by an iridium layer provided on the silicon substrate 10 and a platinum layer provided on the iridium layer. The thickness of the iridium layer is, for example, not less than 5 nm and not more than 100 nm. The thickness of the platinum layer is, for example, not less than 50 nm and not more than 300 nm. The first electrode 32 is a metal layer made of Ti, Pt, Ta, Ir, Sr, In, Sn, Au, Al, Fe, Cr, Ni, Cu, or a mixture or stack of two or more of these. It may be a thing. The first electrode 32 is one electrode for applying a voltage to the piezoelectric body 34.

  The piezoelectric body 34 is provided on the first electrode 32. The piezoelectric body 34 is located between the first electrode 32 and the second electrode 36. The thickness of the piezoelectric body 34 is, for example, not less than 50 nm and not more than 20 μm, preferably not less than 1 μm and not more than 7 μm. Thus, the piezoelectric element 30 is a thin film piezoelectric element. When the thickness of the piezoelectric body 34 is smaller than 50 nm, the output of the piezoelectric driving device 100 may be small. Specifically, when the voltage applied to the piezoelectric body 34 is increased in order to increase the output, the piezoelectric body 34 may cause dielectric breakdown. If the thickness of the piezoelectric body 34 is greater than 20 μm, cracks may occur in the piezoelectric body 34.

As the piezoelectric body 34, a perovskite oxide piezoelectric material is used. Specifically, the material of the piezoelectric body 34 is, for example, lead zirconate titanate (Pb (Zr, Ti) O ₃ : PZT), lead zirconate titanate niobate (Pb (Zr, Ti, Nb) O ₃ ). : PZTN).

  The second electrode 36 is provided on the piezoelectric body 34. The second electrode 36 may be configured by an adhesion layer provided on the piezoelectric body 34 and a conductive layer provided on the adhesion layer. The thickness of the adhesion layer is, for example, 10 nm or more and 100 nm or less. The adhesion layer is, for example, a TiW layer, a Ti layer, a Cr layer, a NiCr layer, or a laminate thereof. The thickness of the conductive layer is, for example, 1 μm or more and 10 μm or less. The conductive layer is, for example, a Cu layer, an Au layer, an Al layer, or a laminate thereof. The second electrode 36 is the other electrode for applying a voltage to the piezoelectric body 34.

In the piezoelectric element 30, as shown in FIGS. 1 and 2, the first electrode 32 is formed as one continuous conductor layer (first electrode layer). On the other hand, the second electrode 36 is divided into five conductor layers (second electrode layers) 36a, 36b, 36c, 36d, and 36e. Similarly, the piezoelectric body 34 is divided into five piezoelectric layers 34a, 34b, 34c, 34d, and 34e.
In the illustrated example, the piezoelectric layers 34a to 34d have the same area, and the piezoelectric layer 34e has a larger area than the piezoelectric layers 34a to 34d. The piezoelectric layers 34a and 34b are provided side by side in the longitudinal direction of the piezoelectric layer, the piezoelectric layers 34c and 34d are provided side by side in the longitudinal direction of the piezoelectric layer, and the piezoelectric layers 34a and 34b and the piezoelectric layer 34c, 34 is provided with a piezoelectric layer 34e. The second electrode layers 36a to 36e are provided on the piezoelectric layers 34a to 34e, respectively. In the example shown in FIG. 1, the planar shapes of the piezoelectric layers 34 a to 34 e and the second electrode layers 36 a to 36 e are rectangular.

  Although not shown, the second electrode 36 may be formed as one continuous conductive layer, and the first electrode 32 may be divided into five conductive layers. In the example shown in FIG. 2, the piezoelectric element 30 is provided on one main surface of the silicon substrate 10, but the other main surface of the silicon substrate 10 (the main surface opposite to the one main surface) is also provided. A piezoelectric element 30 may be provided.

The protruding portion 40 is provided at the distal end portion 12 in the longitudinal direction A of the silicon substrate 10. In the illustrated example, the protrusion 40 is provided on the side surface in the longitudinal direction A of the silicon substrate 10. The protrusion 40 is a member that contacts the rotor 2 and transmits the movement of the silicon substrate 10 to the rotor 2. The protrusion 40 may be provided on the silicon substrate 10 via an adhesive (not shown). The material of the protrusion 40 is, for example, ceramics (specifically, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), silicon nitride (Si ₃ N), etc.).

  4 and 5 are plan views for explaining the longitudinal direction A and the short direction B of the silicon substrate 10. FIG. As shown in FIGS. 4 and 5, a large number of chips 110 can be obtained from a single silicon wafer 4 by arranging a large number of chips 110 on the silicon wafer 4. The orientation in which the chips 110 are arranged is determined in consideration of the Young's modulus of the silicon substrate 10.

  4 and 5, “OF” means an orientation flat (orientation flat), and in the <111> direction (for example, when the silicon substrate 10 is a (110) substrate, (In the [−111] direction).

  As shown in FIG. 4, the longitudinal direction A (direction of arrow A) of the silicon substrate 10 is the <110> direction, and the short direction B (direction of arrow B) of the silicon substrate 10 is the <100> direction. There may be. Here, the <110> direction represents a direction equivalent to the [110] direction, and the <100> direction represents a direction equivalent to the [100] direction. For example, when the silicon substrate 10 is a (110) substrate, the longitudinal direction A of the silicon substrate 10 may be the [−110] direction, and the short direction B of the silicon substrate 10 may be the [001] direction.

  Alternatively, as shown in FIG. 5, the longitudinal direction A of the silicon substrate 10 may be the <111> direction, and the short direction B of the silicon substrate 10 may be the <112> direction. Here, the <111> direction represents a direction equivalent to the [111] direction, and the <112> direction represents a direction equivalent to the [112] direction. For example, when the silicon substrate 10 is a (110) substrate, the longitudinal direction A of the silicon substrate 10 is the [−111] direction, and the short direction B of the silicon substrate 10 is the [1-12] direction. Good.

  In the silicon substrate 10, the Young's modulus is different in two directions perpendicular to each other in the plane. The Young's modulus in the short direction B of the silicon substrate 10 is smaller than the Young's modulus in the longitudinal direction A of the silicon substrate 10. The silicon substrate 10 can be deformed by the deformation of the piezoelectric element 30.

Here, FIG. 6 is a diagram for explaining an electrical connection state between the piezoelectric driving device 100 and the driving circuit 50. As shown in FIG. 6, among the two second electrode layers 36 a to 36 e, the pair of second electrode layers 36 a and 36 d that are diagonally connected are electrically connected to each other via the wiring 60, and the other pair The pair of second electrode layers 36 b and 36 c at the corners are electrically connected to each other through the wiring 62. The wirings 60 and 62 may be formed by a film forming process or may be realized by a wire-like wiring. In the illustrated example, the three second electrode layers 36b, 36e, 36d and the first electrode 32 are electrically connected to the drive circuit 50 via wirings 70, 72, 74, 76, respectively.

  The drive circuit 50 generates an alternating voltage or a pulsating voltage that periodically changes between the pair of second electrode layers 36 a and 36 d and the first electrode 32 and between the second electrode layer 36 e and the first electrode 32. By applying this, the piezoelectric driving device 100 can be ultrasonically vibrated, and the rotor (driven body) 2 that contacts the protrusion 40 can be rotated in a predetermined rotation direction. Here, the “pulsating voltage” means a voltage obtained by adding a DC offset to an AC voltage, and the direction of the voltage (electric field) is one direction from one electrode to the other electrode. The drive circuit 50 applies an alternating voltage or a pulsating voltage between the other pair of second electrode layers 36b and 36c and the first electrode 32, and between the second electrode layer 36e and the first electrode 32. By doing so, it is possible to rotate the rotor 2 which contacts the protrusion part 40 in a reverse direction.

  FIG. 7 is a diagram for explaining the operation of the piezoelectric driving device 100. The protrusion 40 is in contact with the outer periphery of the rotor 2 as shown in FIG. The drive circuit 50 applies an alternating voltage or a pulsating voltage between the pair of second electrode layers 36 a and 36 d and the first electrode 32. Thereby, the piezoelectric layers 34a and 34d expand and contract in the direction of the arrow x in FIG. In response to this, the silicon substrate 10 bends and vibrates in the plane of the silicon substrate 10 (for example, bends and vibrates along the short direction B of the silicon substrate 10 when no voltage is applied to the piezoelectric element 30). To meandering shape (S-shape). Further, the drive circuit 50 applies an alternating voltage or a pulsating voltage between the second electrode layer 36 e and the first electrode 32. As a result, the piezoelectric layer 34e expands and contracts in the direction of the arrow y in FIG. As a result, the silicon substrate 10 vibrates longitudinally within the plane of the silicon substrate 10 (for example, longitudinal vibration along the longitudinal direction A of the silicon substrate 10 in a state where no voltage is applied to the piezoelectric element 30). Due to the bending vibration and longitudinal vibration of the silicon substrate 10 as described above, the protrusion 40 moves elliptically as indicated by an arrow z in FIG. As a result, the rotor 2 rotates in the predetermined direction R (clockwise direction in FIG. 7) around the center 2a.

  When the drive circuit 50 applies an alternating voltage or a pulsating voltage between the pair of second electrode layers 36b and 36c and the first electrode 32, the rotor 2 is in a direction opposite to the direction R (total Rotate in the rotation direction).

  Moreover, it is preferable that the resonance frequency of the flexural vibration and the resonance frequency of the longitudinal vibration of the silicon substrate 10 are the same. Thereby, the rotor 2 can be efficiently rotated.

  The piezoelectric drive device 100 has the following features, for example.

  In the piezoelectric driving device 100, the Young's modulus in the short direction of the silicon substrate 10 is smaller than the Young's modulus in the longitudinal direction of the silicon substrate 10. Thus, in the piezoelectric driving device 100, the amplitude of the bending vibration along the short direction of the silicon substrate 10 is increased by setting the direction in which the Young's modulus is small in the silicon substrate 10 to the short direction instead of the longitudinal direction. Therefore, high output can be achieved.

Here, the larger the amplitude of the bending vibration along the short direction of the silicon substrate, the higher the output of the piezoelectric driving device. On the other hand, the longitudinal vibration along the longitudinal direction of the silicon substrate acts on the contact and separation between the rotor and the protrusion, and does not affect the output of the piezoelectric driving device compared to the bending vibration. Therefore, in the piezoelectric driving device 100, the amplitude of the bending vibration along the short direction of the silicon substrate 10 is formed by forming the silicon substrate 10 so that the Young's modulus in the short direction is smaller than the Young's modulus in the long direction. The output can be increased, and the output can be increased.

  In the piezoelectric driving device 100, the silicon substrate 10 is a {110} substrate. Therefore, the silicon substrate 10 can have different Young's moduli in two directions perpendicular to each other in the plane of the silicon substrate (see an experimental example described later). In the piezoelectric driving device 100, the longitudinal direction and the lateral direction of the silicon substrate 10 can be aligned in two directions orthogonal to each other in the plane of the silicon substrate.

  In the piezoelectric driving device 100, the thickness of the piezoelectric body 34 is not less than 50 nm and not more than 20 μm. Therefore, in the piezoelectric driving device 100, it is possible to increase the output while suppressing the occurrence of cracks in the piezoelectric body 34.

  In the above example, the protrusion 40 is provided at the front end 12 in the longitudinal direction of the silicon substrate 10. However, the piezoelectric driving device according to the present invention has a metal plate made of stainless steel or the like, and has a protrusion. The part 40 may be provided at the front end in the longitudinal direction of the metal plate. In this case, the silicon substrate 10 is provided on a metal plate. However, in order to increase the output of the piezoelectric drive device by forming the silicon substrate 10 so that the Young's modulus in the short direction is smaller than the Young's modulus in the longitudinal direction, the piezoelectric drive device 100 described above is used. Further, it is preferable that no metal plate is provided.

2. Next, a method for manufacturing the piezoelectric drive device 100 according to the present embodiment will be described with reference to the drawings. FIG. 8 is a flowchart for explaining a method of manufacturing the piezoelectric driving device 100 according to this embodiment. FIG. 9 is a plan view schematically showing the manufacturing process of the piezoelectric driving device 100 according to the present embodiment.

  As shown in FIG. 9, silicon wafers 4 having different Young's moduli in two directions orthogonal in the plane are prepared (S1). In the example shown in FIG. 9, the silicon wafer 4 is a silicon wafer cut out on the (110) plane, and has a Young's modulus in the <110> direction (the direction in which the silicon substrate 10 is in the longitudinal direction A) and the <100> direction. This is different from the Young's modulus (the direction in which the silicon substrate 10 is the short direction B).

  As shown in FIG. 4, the piezoelectric element 30 is formed on the silicon wafer 4 (S2). Specifically, the first electrode 32 is formed on the silicon wafer, the piezoelectric body 34 is formed on the first electrode 32, and the second electrode 36 is formed on the piezoelectric body 34. The first electrode 32 and the second electrode 36 are formed by, for example, forming a conductive layer by sputtering, CVD (Chemical Vapor Deposition), or plating, and patterning the conductive layer by photolithography and etching. The The piezoelectric body 34 is formed by, for example, forming an insulating layer by a sol-gel method or a MOD (Metal Organic Deposition) method, and patterning the insulating layer by photolithography and etching.

  Next, the silicon wafer 4 is processed, and the chip 110 (see FIGS. 1 and 2) having the silicon substrate 10, the attachment portion 20, the connection portion 22, and the piezoelectric element 30 is taken out (S3). Specifically, the chip 110 is taken out by photolithography and etching the silicon wafer 4.

As shown in FIGS. 4 and 5, a large number of chips 110 can be taken out from a single silicon wafer 4 by arranging a large number of chips 110 on the silicon wafer 4. In steps S2 and S3, the orientation in which the chips 110 are arranged is determined in consideration of the Young's modulus of the silicon substrate 10. Specifically, the chips 110 are arranged in the silicon wafer 4 so that the Young's modulus in the short direction of the silicon substrate 10 is smaller than the Young's modulus in the longitudinal direction of the silicon substrate 10.

  As shown in FIGS. 1 and 2, the protrusion 40 is attached to the tip portion 12 in the longitudinal direction of the chip 110 (the tip portion in the longitudinal direction of the silicon substrate 10 in the illustrated example) 12 (S4). Specifically, the protrusion 40 is bonded to the tip 12 using an adhesive.

  The piezoelectric driving device 100 can be manufactured through the above steps.

  In the method for manufacturing the piezoelectric driving device 100, the chips 110 are arranged in the silicon wafer 4 so that the Young's modulus in the short direction of the silicon substrate 10 is smaller than the Young's modulus in the longitudinal direction of the silicon substrate 10. Therefore, the piezoelectric drive device 100 that can achieve high output can be manufactured.

3. Experimental Example An experimental example is shown below to describe the present invention more specifically. The present invention is not limited by the following experimental examples.

  As an experimental example, the Young's modulus in the in-plane direction of a silicon (110) wafer (a silicon wafer cut out by the (110) plane) was calculated. Young's modulus was calculated using an elastic stiffness matrix. FIG. 10 is a table showing the basic constants of silicon used when calculating the Young's modulus. In FIG. 10, “cij” indicates the stiffness, and “sij” indicates the compliance.

  11 and 12 are diagrams showing the in-plane distribution of Young's modulus in the silicon (110) wafer calculated by the above method. In FIGS. 11 and 12, the Young's modulus distribution is indicated by a bold line. In FIGS. 11 and 12, the orientation flat is in the [−111] direction.

  As shown in FIG. 11, the Young's modulus in the [001] direction was the smallest in the silicon (110) wafer and was 130.8 GPa. The Young's modulus in the [−110] direction orthogonal to the [001] direction was 169.7 GPa. Therefore, as shown in FIG. 11, the longitudinal direction of the silicon substrate 10 constituting the piezoelectric driving device is the [−110] direction, and the short direction is the [001] direction. The Young's modulus can be made larger than the Young's modulus in the longitudinal direction of the silicon substrate 10. Particularly, since the [001] direction has the smallest Young's modulus in the silicon (110) wafer, the amplitude of the bending vibration along the short direction is the largest in the silicon substrate 10 formed from the silicon (110) wafer. can do.

  As shown in FIG. 12, the Young's modulus in the [1-12] direction was 169.7 GPa. The Young's modulus in the [−111] direction orthogonal to the [1-12] direction was 188.4 GPa. Therefore, as shown in FIG. 12, by setting the longitudinal direction of the silicon substrate 10 constituting the piezoelectric driving device as the [−111] direction and the short direction as the [1-12] direction, The Young's modulus in the direction can be made larger than the Young's modulus in the longitudinal direction of the silicon substrate 10. The [−111] direction is the direction having the largest Young's modulus in the silicon (110) wafer. As shown in FIGS. 11 and 12, the Young's modulus in the [1-11] direction was the same as the Young's modulus in the [−111] direction, and was 188.4 GPa.

4). Device Using Piezoelectric Drive Device The piezoelectric drive device according to the present invention can apply a large force to a driven body by utilizing resonance, and can be applied to various devices. The piezoelectric drive device according to the present invention is, for example, as a drive device in various devices such as a robot (including an electronic component transfer device (IC handler)), a dosing pump, a calendar feeding device for a clock, and a paper feeding mechanism for a printing device. Can be used. Hereinafter, representative embodiments will be described. Hereinafter, an apparatus including the piezoelectric driving apparatus 100 will be described as the piezoelectric driving apparatus according to the present invention.

4.1. Robot FIG. 13 is a diagram for explaining a robot 2050 using the piezoelectric driving device 100. The robot 2050 includes an arm 2010 (a plurality of link portions 2012 (also referred to as “link members”) and a plurality of joint portions 2020 that connect the link portions 2012 in a rotatable or bendable state. It is also called “arm”.

  Each joint portion 2020 includes a piezoelectric drive device 100, and the joint portion 2020 can be rotated or bent by an arbitrary angle using the piezoelectric drive device 100. A robot hand 2000 is connected to the tip of the arm 2010. The robot hand 2000 includes a pair of grip portions 2003. The robot hand 2000 also has a built-in piezoelectric driving device 100, and the piezoelectric driving device 100 can be used to open and close the gripping unit 2003 to grip an object. Further, the piezoelectric driving device 100 is also provided between the robot hand 2000 and the arm 2010, and the robot hand 2000 can be rotated with respect to the arm 2010 using the piezoelectric driving device 100.

  FIG. 14 is a view for explaining a wrist portion of the robot 2050 shown in FIG. The wrist joint portion 2020 sandwiches the wrist rotating portion 2022, and the wrist link portion 2012 is attached to the wrist rotating portion 2022 so as to be rotatable around the central axis O of the wrist rotating portion 2022. . The wrist rotation unit 2022 includes the piezoelectric driving device 100, and the piezoelectric driving device 100 rotates the wrist link unit 2012 and the robot hand 2000 around the central axis O. The robot hand 2000 is provided with a plurality of gripping units 2003. The proximal end portion of the grip portion 2003 is movable in the robot hand 2000, and the piezoelectric drive device 100 is mounted on the base portion of the grip portion 2003. For this reason, by operating the piezoelectric driving device 100, the gripping portion 2003 can be moved to grip the target. The robot is not limited to a single-arm robot, and the piezoelectric drive device 100 can be applied to a multi-arm robot having two or more arms.

  Here, in the wrist joint 2020 and the robot hand 2000, in addition to the piezoelectric drive device 100, a power line for supplying power to various devices such as a force sensor and a gyro sensor, a signal line for transmitting a signal, and the like And requires a lot of wiring. Therefore, it is very difficult to arrange wiring inside the joint portion 2020 and the robot hand 2000. However, since the piezoelectric drive device 100 can reduce the drive current as compared with a normal electric motor, wiring can be arranged even in a small space such as the joint portion 2020 (particularly, the joint portion at the tip of the arm 2010) or the robot hand 2000. Is possible.

4.2. Pump FIG. 15 is a diagram for explaining an example of a liquid feed pump 2200 using the piezoelectric driving device 100. The liquid feed pump 2200 includes a reservoir 2211, a tube 2212, a piezoelectric driving device 100, a rotor 2222, a deceleration transmission mechanism 2223, a cam 2202, a plurality of fingers 2213, 2214, 2215, 2216, and a case 2230. 2217, 2218, and 2219 are provided.

  The reservoir 2211 is a storage unit for storing a liquid to be transported. The tube 2212 is a tube for transporting the liquid sent out from the reservoir 2211. The protrusion 40 of the piezoelectric driving device 100 is provided in a state of being pressed against the side surface of the rotor 2222, and the piezoelectric driving device 500 rotationally drives the rotor 2222. The rotational force of the rotor 2222 is transmitted to the cam 2202 via the deceleration transmission mechanism 2223. Fingers 2213 to 2219 are members for closing the tube 2212. When the cam 2202 rotates, the fingers 2213 to 2219 are sequentially pushed outward in the radial direction by the protrusion 2202A of the cam 2202. The fingers 2213 to 2219 close the tube 2212 in order from the upstream side in the transport direction (reservoir 2211 side). Thereby, the liquid in the tube 2212 is transported to the downstream side in order. In this way, it is possible to realize a small liquid feed pump 2200 that can feed a very small amount with high accuracy.

  In addition, arrangement | positioning of each member is not restricted to what was illustrated. Further, a member such as a finger may not be provided, and a ball or the like provided on the rotor 2222 may close the tube 2212. The liquid feed pump 2200 as described above can be used for a medication device that administers a drug solution such as insulin to the human body. Here, since the drive current can be made smaller than that of a normal electric motor by using the piezoelectric drive device 100, the power consumption of the dosing device can be suppressed. Therefore, it is particularly effective when the medication apparatus is battery-driven.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 2 ... Rotor, 2a ... Center, 4 ... Silicon wafer, 10 ... Silicon substrate, 12 ... Tip part, 20 ... Mounting part, 22 ... Connection part, 24 ... Screw, 30 ... Piezoelectric element, 32 ... 1st electrode, 34 ... Piezoelectric material, 34a, 34b, 34c, 34d, 34e ... piezoelectric material layer, 36 ... second electrode, 36a, 36b, 36c, 36d, 36e ... second electrode layer, 40 ... projection, 50 ... drive circuit, 60, 62, 70, 72, 74, 76 ... wiring, 100 ... piezoelectric drive device, 101 ... motor, 110 ... chip, 2000 ... robot hand, 2003 ... gripping part, 2010 ... arm, 2012 ... link part, 2020 ... joint part, 2050 ... Robot, 2200 ... Liquid feed pump, 2202 ... Cam, 2202A ... Projection, 2211 ... Reservoir, 2212 ... Tube, 2213, 2214, 2215, 2 16,2217,2218,2219 ... finger, 2222 ... rotor, 2223 ... deceleration transmission mechanism, 2230 ... case

Claims (13)

A silicon substrate having a longitudinal direction and a transverse direction orthogonal to the longitudinal direction;
A piezoelectric element provided on the silicon substrate and having a first electrode, a second electrode, and a piezoelectric body positioned between the first electrode and the second electrode;
A protrusion provided at the distal end in the longitudinal direction and in contact with the driven body;
Including
The piezoelectric drive device, wherein the Young's modulus in the short direction of the silicon substrate is smaller than the Young's modulus in the longitudinal direction of the silicon substrate. In claim 1,
The piezoelectric drive device, wherein the silicon substrate is a {110} substrate. In claim 2,
The longitudinal direction of the silicon substrate is a <110> direction,
The piezoelectric drive device, wherein the lateral direction of the silicon substrate is a <100> direction. In claim 2,
The longitudinal direction of the silicon substrate is a <111> direction,
The piezoelectric drive device, wherein the lateral direction of the silicon substrate is a <112> direction. In any one of Claims 1 thru | or 4,
The piezoelectric driving device, wherein the piezoelectric body has a thickness of 50 nm or more and 20 μm or less. Preparing silicon wafers having different Young's moduli in two directions perpendicular to each other in a plane;
Forming a piezoelectric element having a first electrode, a second electrode, and a piezoelectric body located between the first electrode and the second electrode on the silicon wafer;
Processing the silicon wafer to take out a chip having a silicon substrate having a longitudinal direction and a transverse direction orthogonal to the longitudinal direction, and the piezoelectric element formed on the silicon substrate;
Attaching a protrusion contacting the driven body to the tip in the longitudinal direction of the chip;
Including
A method of manufacturing a piezoelectric drive device, wherein the chips are arranged in the silicon wafer such that a Young's modulus in the short direction of the silicon substrate is smaller than a Young's modulus in the longitudinal direction of the silicon substrate. In claim 6,
The method for manufacturing a piezoelectric driving device, wherein the silicon substrate is a {110} substrate. In claim 7,
The longitudinal direction of the silicon substrate is a <110> direction,
The method for manufacturing a piezoelectric driving device, wherein the short direction of the silicon substrate is a <100> direction. In claim 7,
The longitudinal direction of the silicon substrate is a <111> direction,
The method for manufacturing a piezoelectric driving device, wherein the lateral direction of the silicon substrate is a <112> direction. In any one of Claims 6 thru | or 9,
The method for manufacturing a piezoelectric driving device, wherein the piezoelectric body has a thickness of 50 nm to 20 μm. A piezoelectric driving device according to any one of claims 1 to 5,
A rotor rotated by the piezoelectric drive device;
Including a motor. A plurality of link parts;
A joint part connecting a plurality of the link parts;
The piezoelectric driving device according to any one of claims 1 to 5, wherein a plurality of the link portions are rotated by the joint portions,
Including robots. A piezoelectric driving device according to any one of claims 1 to 5,
A tube that transports the liquid;
A plurality of fingers for closing the tube by driving the piezoelectric driving device;
Including a pump.

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