JP2018085866A - Oscillator, piezoelectric actuator, piezoelectric motor, robot, electronic component transfer device, and method of manufacturing oscillator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillator capable of improving current efficiency and a method of manufacturing the oscillator, as well as a piezoelectric actuator, a piezoelectric motor, a robot, and an electronic component transfer device comprising the oscillator.SOLUTION: An oscillator comprises: a substrate; and a piezoelectric element having an electrode arranged on one surface side of the substrate. The substrate includes: a first semiconductor part formed from one of a p-type semiconductor and an n-type semiconductor; and a second semiconductor part that is arranged on the surface of the electrode of the first semiconductor part so as to overlap at least a portion of the electrode in plan view as seen from a direction in which the first semiconductor part and the electrode overlap each other, and that is formed from the other one of the p-type semiconductor and the n-type semiconductor.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vibrator, a piezoelectric actuator, a piezoelectric motor, a robot, an electronic component transport apparatus, and a vibrator manufacturing method.

  Conventionally, a piezoelectric actuator including a vibrator using a piezoelectric element is known (see, for example, Patent Document 1). For example, an actuator described in Patent Document 1 includes a silicon substrate and a piezoelectric element configured by laminating a lower electrode, lead zirconate titanate (PZT), and an upper electrode in this order on the silicon substrate. I have.

JP 2006-096187 A

  In a piezoelectric actuator in which a piezoelectric element is arranged on a silicon substrate like the actuator described in Patent Document 1, generally, a dielectric film such as a silicon oxide film is provided between the silicon substrate and the lower electrode of the piezoelectric element. Is done. The film thickness of such a dielectric film is generally relatively thin for convenience of production efficiency and the like. Therefore, conventionally, since the capacitance between the lower electrode and the silicon substrate is relatively large, when a current for driving the piezoelectric element is supplied to the lower electrode, a part of the current passes through the dielectric film. As a result, there is a problem that current efficiency is lowered.

  An object of the present invention is to provide a vibrator capable of improving current efficiency and a method of manufacturing the vibrator, and to provide a piezoelectric actuator, a piezoelectric motor, a robot, and an electronic component transport device including the vibrator. .

The above object is achieved by the present invention described below.
The vibrator of the present invention includes a substrate,
A piezoelectric element disposed on the substrate,
The piezoelectric element has an electrode between the substrate and
The substrate is
a first semiconductor portion composed of one of a p-type semiconductor and an n-type semiconductor;
Between the first semiconductor part and the electrode, joined to the first semiconductor, and arranged to overlap at least part of the electrode in a plan view as seen from the direction in which the first semiconductor part and the electrode overlap; and a second semiconductor portion made of the other of the p-type and n-type semiconductors.

  According to such a vibrator, the first semiconductor part and the second semiconductor part form a pn junction, thereby restricting the flow of current between the electrode and the substrate, and reducing leakage current in the vibrator. can do. Therefore, the current efficiency of the vibrator can be improved.

The vibrator according to the aspect of the invention preferably includes a dielectric layer disposed between the substrate and the electrode.
Thereby, it is possible to make it difficult for current to flow from the electrode to the substrate.

In the vibrator according to the aspect of the invention, it is preferable that the second semiconductor portion is disposed between the first semiconductor portion and the dielectric layer.
Thereby, a pn junction is interposed between the electrode and the first semiconductor portion, and the current flow between the electrode and the substrate can be effectively limited.

In the resonator according to the aspect of the invention, the first semiconductor portion is formed of a p-type semiconductor,
The second semiconductor part is preferably made of an n-type semiconductor.
Thereby, the flow of current from the electrode to the substrate (first semiconductor part) can be limited.

In the vibrator according to the aspect of the invention, it is preferable that the piezoelectric element includes a piezoelectric body containing lead zirconate titanate.
Thereby, a piezoelectric element having excellent piezoelectricity can be realized. Therefore, the current efficiency of the vibrator can be further improved.

In the vibrator according to the aspect of the invention, it is preferable that the piezoelectric body has a bulk shape.
Thereby, manufacture of a piezoelectric element can be made easy.

In the vibrator according to the aspect of the invention, it is preferable that the electrode is electrically connected to a drive circuit that generates a drive signal for driving the piezoelectric element.
Thus, when a drive signal is input to the electrode on the substrate, the effect of increasing the current efficiency of the vibrator by limiting the current flow between the electrode and the substrate becomes significant.

The piezoelectric actuator of the present invention includes the vibrator of the present invention,
And a convex portion provided on the vibrator.
According to such a piezoelectric actuator, it is possible to efficiently generate a driving force by improving the current efficiency of the vibrator.

The piezoelectric motor of the present invention includes the vibrator of the present invention.
According to such a piezoelectric motor, it is possible to efficiently generate a driving force (rotational force) by improving the current efficiency of the vibrator.

A robot according to the present invention includes the vibrator according to the present invention.
According to such a robot, the characteristics of the robot can be improved by improving the current efficiency of the vibrator.

An electronic component conveying apparatus according to the present invention includes the vibrator according to the present invention.
According to such an electronic component transport apparatus, the characteristics of the electronic component transport apparatus can be improved by improving the current efficiency of the vibrator.

The method for manufacturing a vibrator according to the present invention includes a substrate preparation step of preparing a substrate,
An element disposing step of disposing a piezoelectric element having an electrode on one surface side of the substrate,
The substrate prepared in the substrate preparation step is disposed on the first semiconductor unit and the first semiconductor unit composed of one of a p-type semiconductor and an n-type semiconductor, A second semiconductor part composed of the other semiconductor of
The element arranging step includes at least a part of the electrode in a plan view as viewed from a direction in which the first semiconductor part and the electrode overlap on the opposite side of the second semiconductor part from the first semiconductor part. The piezoelectric element is disposed so as to overlap the second semiconductor portion.

  According to such a method for manufacturing a vibrator, a vibrator having excellent current efficiency can be obtained.

It is a top view which shows schematic structure of the piezoelectric motor which concerns on 1st Embodiment of this invention. It is a disassembled perspective view of the piezoelectric actuator with which the piezoelectric motor shown in FIG. 1 is provided. It is the sectional view on the AA line in FIG. It is a figure for demonstrating operation | movement of the piezoelectric motor shown in FIG. It is a schematic diagram for demonstrating the effect | action of the pn junction part with which the piezoelectric actuator shown in FIG. 3 is provided. It is a schematic diagram for demonstrating the effect | action of the modification of the pn junction part with which the piezoelectric actuator shown in FIG. 3 is provided. 2 is a flowchart for explaining a method of manufacturing a vibrator included in the piezoelectric motor (piezoelectric actuator) shown in FIG. 1. It is sectional drawing which shows the piezoelectric actuator which concerns on 2nd Embodiment of this invention. It is a perspective view of the board | substrate with which the piezoelectric actuator shown in FIG. 8 is provided. It is sectional drawing which shows the piezoelectric actuator which concerns on 3rd Embodiment of this invention. It is a perspective view of the support substrate with which the piezoelectric actuator shown in FIG. 10 is provided. It is a perspective view which shows embodiment of the robot of this invention. It is a perspective view which shows embodiment of the electronic component conveying apparatus of this invention. It is a perspective view of the electronic component holding part with which the electronic component conveyance apparatus shown in FIG. 13 is provided.

  Hereinafter, a vibrator, a piezoelectric actuator, a piezoelectric motor, a robot, an electronic component transport apparatus, and a vibrator manufacturing method according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

(Piezoelectric motor)
First, the piezoelectric motor of the present invention (piezoelectric motor including the vibrator or piezoelectric actuator of the present invention) will be described.

<First Embodiment>
FIG. 1 is a plan view showing a schematic configuration of the piezoelectric motor according to the first embodiment of the present invention. FIG. 2 is an exploded perspective view of the piezoelectric actuator provided in the piezoelectric motor shown in FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is a diagram for explaining the operation of the piezoelectric motor shown in FIG. In the following, for convenience of explanation, the upper side in FIG. 3 is also referred to as “upper” and the lower side is also referred to as “lower”.

  A piezoelectric motor 200 shown in FIG. 1 includes a rotor 210 that is a driven portion (driven portion) that can rotate around a rotation axis O, and a piezoelectric actuator 100 that contacts an outer peripheral surface 211 of the rotor 210. Yes. In the piezoelectric motor 200, the driving force is transmitted to the rotor 210 by driving (vibrating) the piezoelectric actuator 100, and the rotor 210 is rotated (rotated) around the rotation axis O. In addition, although the piezoelectric motor 200 is a structure which rotates a to-be-driven part in illustration, it is not limited to this, For example, the structure to which a to-be-driven part is linearly moved may be sufficient. Further, the piezoelectric motor 200 may have a configuration in which a plurality of piezoelectric actuators 100 are brought into contact with one driven part.

[Piezoelectric actuator]
The piezoelectric actuator 100 includes the vibrator 1 and a convex portion 110 provided on the vibrator 1.

  As shown in FIG. 2, the vibrator 1 includes a pair of substrates 2 and 3, and a piezoelectric element 4 and a spacer 5 disposed between the substrates 2 and 3. Here, the wiring 61 is disposed on the surface of the substrate 2 on the substrate 3 side (the upper surface in FIG. 2). A wiring 62 is disposed on the surface of the substrate 3 on the substrate 2 side (the lower surface in FIG. 2). As shown in FIG. 3, the upper surface of the substrate 2 and the lower surface of the piezoelectric element 4 are connected so that the piezoelectric element 4 (more specifically, a first electrode 41 described later) is electrically connected to the wiring 61. Are bonded via an insulating adhesive 71. Similarly, the lower surface of the substrate 3 and the upper surface of the piezoelectric element 4 are made of an insulating adhesive so that the piezoelectric element 4 (more specifically, a second electrode 43 described later) is electrically connected to the wiring 62. 72. Although not shown, the upper surface of the substrate 2, the lower surface of the substrate 3, and the spacer 5 are bonded via an adhesive similar to the adhesives 71 and 72. Each of the adhesives 71 and 72 is not particularly limited, and examples thereof include various adhesives such as epoxy, acrylic, and silicon. Further, the adhesives 71 and 72 may be omitted as long as they are solid bonding such as Au-Au bonding without using an adhesive.

  The substrate 2 includes a vibrating part 21 joined to the piezoelectric element 4 by the adhesive 71 described above, a support part 22 joined to the spacer 5 by an adhesive (not shown), and a pair of connections connecting them. Part 23. The vibration part 21 has a rectangular shape (longitudinal shape) in a plan view (hereinafter also simply referred to as “plan view”) viewed from the direction in which the substrates 2 and 3 overlap. Further, the support portion 22 has a shape that surrounds the outer periphery of a portion on one end side in the longitudinal direction of the vibration portion 21 in a plan view. Further, the pair of connection portions 23 connect both ends of the vibration portion 21 in the width direction (a direction orthogonal to the longitudinal direction) and the support portion 22.

  In the present embodiment, the substrates 2 and 3 have substantially the same plan view shape, and the substrate 3 is bonded to the piezoelectric element 4 by the adhesive 72 described above, similarly to the substrate 2. 31, a support portion 32 joined to the spacer 5 by an adhesive (not shown), and a pair of connection portions 33 that connect them.

  In addition, the shape, arrangement | positioning, etc. of the vibration parts 21 and 31, the support parts 22 and 32, and the connection parts 23 and 33 are not limited to the thing of illustration. For example, the support parts 22 and 32 may be provided separately for each of the connection parts 23 and 33. Further, the number, shape, arrangement, and the like of the connecting portions 23 and 33 are arbitrary. Moreover, the planar view shapes of the substrates 2 and 3 may be different from each other.

  The substrates 2 and 3 are not particularly limited, and for example, a semiconductor substrate such as a silicon substrate or a silicon carbide substrate can be used. By using a semiconductor substrate (particularly a silicon substrate) as the substrates 2 and 3, the substrates 2 and 3 having the vibration parts 21 and 31, the support parts 22 and 32, and the connection parts 23 and 33 as described above are formed into a silicon wafer process (MEMS). Process) with high productivity and high accuracy.

  As shown in FIG. 3, a dielectric layer 24 is provided on the surface (upper surface) of the substrate 2 on the piezoelectric element 4 side. Thereby, the short circuit of the wiring 61 through the board | substrate 2 can be reduced. Similarly, a dielectric layer 34 is provided on the surface (lower surface) of the substrate 3 on the piezoelectric element 4 side. Thereby, the short circuit of the wiring 62 through the board | substrate 3 can be reduced. For example, when the substrates 2 and 3 are silicon substrates, the dielectric layers 24 and 34 are silicon oxide films formed by thermally oxidizing the surface of the silicon substrate.

  In addition, the substrate 2 includes a plate-like first semiconductor unit 25 and a plurality of second semiconductor units 26 provided on the surface of the first semiconductor unit 25 on the piezoelectric element 4 side. Here, one of the first semiconductor unit 25 and the second semiconductor unit 26 is configured by an n-type semiconductor, and the other is configured by a p-type semiconductor. A pn junction is formed between the first semiconductor unit 25 and the second semiconductor unit 26.

In particular, the plurality of second semiconductor portions 26 are provided corresponding to a plurality of first electrodes 41 of the piezoelectric element 4 described later, and are respectively interposed between the first electrodes 41 and the first semiconductor portion 25. . By arranging the second semiconductor part 26 in this way, a pn junction by the first semiconductor part 25 and the second semiconductor part 26 is formed so as to block the flow of current between the plurality of first electrodes 41 via the substrate 2. Can be arranged. Thereby, the flow of current between the first electrode 41 and the substrate 2 can be restricted, and the leakage current in the vibrator 1 can be reduced. As a result, the current efficiency of the vibrator 1 can be improved. This point will be described in detail later.
The semiconductor constituting the substrate 3 may be either an n-type or p-type semiconductor, or may be a genuine semiconductor that does not contain impurities. The substrate 3 may have the same configuration as the substrate 2.

  In addition, the board | substrate 2 may have parts other than the 1st semiconductor part 25 and the 2nd semiconductor part 26 which were mentioned above, for example, the surface on the opposite side to the 2nd semiconductor part 26 of the 1st semiconductor part 25 ( On the lower surface, a semiconductor portion made of a semiconductor having a different conductivity type or doping amount from the first semiconductor portion 25 may be provided. Further, in the drawing, the interface between the first semiconductor unit 25 and the second semiconductor unit 26 is clearly shown, but such an interface may not be clear. For example, in the vicinity of the interface, the first semiconductor unit 25 and the impurities contained in the second semiconductor part 26 may be mixed.

  The vibrating portions 21 and 31 of the substrates 2 and 3 described above sandwich the piezoelectric element 4 and constitute a “vibrating plate” that vibrates together with the piezoelectric element 4. At one end portion (tip portion) in the longitudinal direction of such a vibration portion, a convex portion 110 is provided at the center portion in the width direction. The convex portion 110 functions as a transmission portion that transmits the vibration of the vibrator 1 to the rotor 210 by frictional sliding. For example, a member made of a material having excellent wear resistance such as ceramics is used as the one end. It is comprised by joining to a part with an adhesive agent etc. In addition, the shape of the convex part 110 should just be able to transmit a driving force to the rotor 210 (driven part), and is not limited to the shape of illustration.

  As shown in FIGS. 1 and 2, the piezoelectric element 4 has a plurality (five in the drawing) of first electrodes 41, piezoelectric bodies 42, and second electrodes 43, which are stacked in this order. Has been configured. The piezoelectric body 42 has a plate shape, and has the same planar view shape as the vibrating portions 21 and 31 of the substrates 2 and 3 described above. Five first electrodes 41 are provided on one surface (lower surface) of the piezoelectric body 42, and second electrodes 43 are provided on the other surface (upper surface).

  The five first electrodes 41 include a first electrode 41e disposed along the longitudinal direction of the piezoelectric body 42 at the center in the width direction of the piezoelectric body 42, and the width direction of the piezoelectric body 42 with respect to the first electrode 41e. Two first electrodes 41a and 41b arranged along the longitudinal direction of the piezoelectric body 42 on one side of the piezoelectric body 42 and the longitudinal direction of the piezoelectric body 42 on the other side in the width direction of the piezoelectric body 42 with respect to the first electrode 41e. And two first electrodes 41c and 41d arranged along the line.

  And the laminated body containing the 1st electrode 41a, the piezoelectric material 42, and the 2nd electrode 43 comprises the piezoelectric element 4a. Similarly, the laminated body including the first electrodes 41b, 41c, 41d, and 41e, the piezoelectric body 42, and the second electrode 43 constitutes the piezoelectric elements 4b, 4c, 4d, and 4e. Thus, the piezoelectric element 4 has five piezoelectric elements 4a, 4b, 4c, 4d, and 4e.

  Thus, the first electrodes 41a, 41b, 41c, 41d, and 41e are individual electrodes that are individually provided for the piezoelectric elements 4a, 4b, 4c, 4d, and 4e. On the other hand, the second electrode 43 is a common electrode provided in common to the piezoelectric elements 4a, 4b, 4c, 4d, and 4e. The piezoelectric body 42 is integrally provided in common with the piezoelectric elements 4a, 4b, 4c, 4d, and 4e. Note that the piezoelectric body 42 may be provided individually for each of the piezoelectric elements 4a, 4b, 4c, 4d, and 4e.

  The constituent materials of the first and second electrodes 41 and 43 are not particularly limited. For example, aluminum (Al), nickel (Ni), gold (Au), platinum (Pt), iridium (Ir), copper Examples thereof include metal materials such as (Cu).

  The piezoelectric body 42 expands and contracts in the direction along the longitudinal direction of the vibrating portions 21 and 31 of the substrates 2 and 3 described above when an electric field in the direction along the thickness direction of the piezoelectric body 42 is applied. Examples of the constituent material of the piezoelectric body 42 include lead zirconate titanate (PZT), barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, zinc oxide, Examples thereof include piezoelectric ceramics such as barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, and lead scandium niobate. In addition to the above-described piezoelectric ceramics, polyvinylidene fluoride, crystal, or the like may be used as the constituent material of the piezoelectric body 42.

  Among these, as a constituent material of the piezoelectric body 42, it is preferable to use lead zirconate titanate. Thus, when the piezoelectric element 4 has the piezoelectric body 42 containing lead zirconate titanate, the piezoelectric element 4 having excellent piezoelectricity can be realized. Therefore, the current efficiency of the vibrator 1 can be further improved.

  The piezoelectric body 42 may be formed from, for example, a bulk material, or may be formed using a sol-gel method or a sputtering method, but is preferably formed from a bulk material. That is, the piezoelectric body 42 is preferably in a bulk shape. Thereby, manufacture of the piezoelectric element 4 becomes easy. “Bulk” means a material that is not a thin film, for example, a thick mass, and includes a collection of a plurality of materials, for example, a stack.

  Further, the support portions 22 and 32 of the substrates 2 and 3 described above sandwich the spacer 5, the support portion 22 supports the vibrating portion 21 via a pair of connection portions 23, and the support portion 32 The vibration part 31 is supported via a pair of connection parts 33. Neither the piezoelectric element 4 nor the spacer 5 is disposed between the connecting portions 23 and 33, and a gap corresponding to the thickness of the piezoelectric element 4 or the spacer 5 is formed.

  The spacer 5 has substantially the same shape and size as the support portions 22 and 32 of the substrates 2 and 3 described above in a plan view. The spacer 5 has a function of increasing the rigidity of the support portions 22 and 32. Further, at least the surface of the spacer 5 has a dielectric property. Thereby, the short circuit of the wirings 61 and 62 can be prevented via the spacer 5. The constituent material of the spacer 5 is not particularly limited, and examples thereof include various ceramics such as zirconia, alumina, and titania, silicon, and various resin materials. Note that the spacer 5 can also be configured using a conductive material such as a metal material. In this case, the surface of the spacer 5 may be insulated. The spacer 5 may be composed of a single member, but may be composed of a plurality of members, for example, a laminate in which a plurality of layers are laminated and bonded.

  As shown in FIG. 2, the wiring 61 is disposed on the dielectric layer 24 described above, and is located between the substrate 2, the piezoelectric element 4, and the spacer 5. On the other hand, the wiring 62 is disposed on the dielectric layer 34 described above and is located between the substrate 3, the piezoelectric element 4, and the spacer 5. Thus, the wiring 61 is arranged on one side (lower side) with respect to the piezoelectric element 4 and the spacer 5, and the wiring 62 is arranged on the other side (upper side), thereby preventing a short circuit between the wiring 61 and the wiring 62. However, the degree of freedom of arrangement of the wiring 61 and the wiring 62 can be increased.

  The wiring 61 includes a plurality of wirings 61a, 61b, 61c, 61d, and 61e. The wirings 61 a, 61 b, 61 c, 61 d, 61 e are respectively disposed on the vibration part 21 and the support part 22 via the connection part 23 of the substrate 2, and one end part is disposed on the vibration part 21. The other end portion is disposed on the support portion 22. One ends of the wirings 61a, 61b, 61c, 61d, and 61e are provided corresponding to the piezoelectric elements 4a, 4b, 4c, 4d, and 4e, and are connected to the first electrodes 41a, 41b, 41c, 41d, and 41e. It is connected. The other end portions of the wirings 61a, 61b, 61c, 61d, and 61e are exposed from between the support portion 22 of the substrate 2 and the spacer 5, and are electrically connected to a driving circuit (not shown) through a flexible wiring substrate (not shown). It is connected to the.

  On the other hand, the wiring 62 is disposed over the vibration part 31 and the support part 32 via the connection part 33 of the substrate 3, one end is disposed on the vibration part 31, and the other end is on the support part 32. Is arranged. One end of the wiring 62 is connected to the second electrode 43 of the piezoelectric element 4. The other end portion of the wiring 62 is exposed from between the support portion 32 of the substrate 3 and the spacer 5 and is electrically connected (grounded) to a ground potential via a flexible wiring substrate (not shown).

  The constituent material of the wirings 61 and 62 is not particularly limited, and examples thereof include metal materials such as aluminum (Al), nickel (Ni), gold (Au), platinum (Pt), and copper (Cu). It is done. Moreover, it does not specifically limit as a formation method of the wiring 61 and 62, For example, vapor deposition, sputtering, a plating method etc. can be used.

  The piezoelectric motor 200 configured as described above operates when a drive signal having a predetermined frequency is input to the first electrode 41 of the piezoelectric element 4 via the wiring 61 from a drive circuit (not shown). For example, the phase difference between the drive signal to the piezoelectric elements 4a and 4d and the drive signal to the piezoelectric elements 4b and 4c is 180 °, and the order of the drive signal to the piezoelectric elements 4a and 4d and the drive signal to the piezoelectric element 4e is By setting the phase difference to 30 °, the piezoelectric elements 4 are formed into an S-shape as shown in FIG. 4 together with the vibrating portions 21 and 31 of the substrates 2 and 3 by expansion and contraction of the piezoelectric elements 4a, 4b, 4c, 4d, and 4e. It bends and vibrates, whereby the tip of the convex portion 110 moves elliptically. As a result, the outer surface 211 of the rotor 210 repeatedly receives a driving force in one direction from the convex portion 110 and rotates around the rotation axis O in the direction of the arrow. If the drive signal is applied to the piezoelectric element 4e so that the phase difference from the drive signal to the piezoelectric elements 4a and 4d is 210 ° (that is, the phase is opposite to the phase condition that has been rotated once), The rotor 210 can be reversely rotated.

Hereinafter, the first semiconductor part 25 and the second semiconductor part 26 of the substrate 2 will be described in detail.
FIG. 5 is a schematic diagram for explaining the operation of the pn junction provided in the piezoelectric actuator shown in FIG. FIG. 6 is a schematic diagram for explaining the operation of a modified example of the pn junction provided in the piezoelectric actuator shown in FIG.

  As described above, the vibrator 1 includes the substrate 2 and the piezoelectric element 4 having the first electrode 41 that is an “electrode” disposed on one surface (upper surface) side of the substrate 2. The substrate 2 is formed on the first semiconductor part 25 made of one of the p-type and n-type semiconductors, and on the surface of the first semiconductor part 25 on the first electrode 41 side. The second semiconductor unit 26 is arranged to overlap at least a part of the first electrode 41 in a plan view as viewed from the direction in which the first electrode 41 and the first electrode 41 overlap, and is configured by the other semiconductor of the p-type and the n-type. And having.

  According to such a vibrator 1, the first semiconductor portion 25 and the second semiconductor portion 26 form a pn junction, thereby restricting the flow of current between the first electrode 41 and the substrate 2. The leakage current in 1 can be reduced. Therefore, the current efficiency of the vibrator 1 can be improved. In addition, since the part which overlaps with the 1st electrode 41 in planar view of the wiring 61 is electrically connected to the 1st electrode 41, it can be regarded as a part of 1st electrode 41, In that case, the said part and It can be said that the first electrode 41 constitutes an “electrode”.

  More specifically, as shown in FIG. 5, the first electrode 41 that is an “electrode” is electrically connected to a drive circuit 10 that generates a drive signal for driving the piezoelectric element 4. A current is input from the drive circuit 10 to the first electrode 41 of the piezoelectric element 4 as a drive signal. At this time, the current input to the first electrode 41 flows to the second electrode 43 via the piezoelectric body 42 as shown by the solid arrow in FIG. 5, thereby driving the piezoelectric element 4. When the drive signal is input to the first electrode 41 on the substrate 2 as described above, the current of the vibrator 1 by limiting the flow of current between the first electrode 41 and the substrate 2 as described below. The effect of increasing the efficiency becomes remarkable.

  The vibrator 1 includes a dielectric layer 24 disposed between the substrate 2 and a first electrode 41 that is an “electrode”. Thereby, it is possible to make it difficult for current to flow from the first electrode 41 to the substrate 2.

  However, the first electrode 41 faces the substrate 2 which is a semiconductor substrate through the dielectric layer 24, and the dielectric layer 24 forms the capacitor Cs. Since the dielectric constant of the dielectric layer 24 is smaller than that of the piezoelectric body 42, if the thickness and area are the same, the capacitor Cs is smaller than the capacitor Cp formed by the piezoelectric body 42, but the thickness of the dielectric layer 24 is piezoelectric. Since the thickness of the body 42 is extremely thin, the difference in capacitance between the capacitor Cs and the capacitor Cp may be reduced.

  Therefore, if the substrate 2 is, for example, a simple silicon substrate, at least a part of the current input to the first electrode 41 passes through the dielectric layer 24 as indicated by a two-dot chain line arrow in FIG. 2 flows as a leakage current. Such a leakage current (hereinafter, also simply referred to as “leakage current”) is input to the other first electrode 41 through the substrate 2 serving as the resistance R, leading to a decrease in the current efficiency of the vibrator 1 or the vibrator 1. May cause unintentional vibration.

  Therefore, in the vibrator 1, as described above, by providing a pn junction on the substrate 2, a current flow from the first electrode 41 to the substrate 2 or a current flow from the substrate 2 to the first electrode 41 can be achieved. Limit and reduce leakage current as described above.

  For example, as illustrated in FIG. 5, when the first semiconductor unit 25 is configured by a p-type semiconductor and the second semiconductor unit 26 is configured by an n-type semiconductor, the current input to the first electrode 41 is Even if it flows to the n-type second semiconductor portion 26 immediately below the first electrode 41, the first pn junction formed by the lower surface and side surfaces of the second semiconductor portion 26 and the p-type first semiconductor portion 25 causes the first The flow to the semiconductor unit 25 is prevented. Therefore, it can be reduced that the current input to the first electrode 41 becomes a leakage current and is input to the other first electrode 41.

  In addition, as shown in FIG. 6, when the first semiconductor unit 25 is formed of an n-type semiconductor and the second semiconductor unit 26 is formed of a p-type semiconductor, the current input to the first electrode 41 is Even if it flows to the p-type second semiconductor part 26 immediately below the first electrode 41, it flows to the n-type first semiconductor part 25, but the lower surface and side surfaces of the other second semiconductor part 26 and the n-type first semiconductor The pn junction formed by the portion 25 is prevented from flowing to the other second semiconductor portion 26. Therefore, it can be reduced that the current input to the first electrode 41 becomes a leakage current and is input to the other first electrode 41.

Thus, one of the first semiconductor part 25 and the second semiconductor part 26 is composed of a p-type semiconductor,
Although the other is made of an n-type semiconductor, leakage current can be reduced. However, as shown in FIG. 5 described above, the first semiconductor portion 25 is made of a p-type semiconductor, and the second semiconductor portion 26 is made. Is preferably composed of an n-type semiconductor. Thereby, as described above, the flow of current from the first electrode 41 to the substrate 2 (first semiconductor unit 25) can be limited. Therefore, the leakage current is reduced from flowing through the first semiconductor unit 25, and the current efficiency of the vibrator 1 can be effectively improved.

  The second semiconductor unit 26 is disposed between the first semiconductor unit 25 and the dielectric layer 24. As a result, a pn junction is interposed between the first electrode 41 and the first semiconductor unit 25, and the current flow between the first electrode 41 and the substrate 2 can be effectively limited.

  Here, the second semiconductor unit 26 does not have to overlap at least a part of the corresponding first electrode 41 and the other first electrode 41 in plan view, but both the wiring 61 and the first electrode 41 are not included. It is preferable that the first electrode 41 and the first electrode 41 are disposed over the region. Thereby, the flow of current between the first electrode 41 and the substrate 2 can be effectively limited (blocked). For example, in plan view, the outer peripheral edge of the second semiconductor unit 26 is located outside the outer peripheral edge of the portion of the wiring 61 that overlaps the first electrode 41, and a distance L1 (see FIG. 3) between these outer peripheral edges is set. It is preferable that it is 2 micrometers or more. Further, in plan view, the outer peripheral edge of the second semiconductor portion 26 is located outside the outer peripheral edge of the first electrode 41, and the distance L2 (see FIG. 3) between these outer peripheral edges is 2 μm or more. Is more preferable.

  In addition, the piezoelectric actuator 100 includes the vibrator 1 as described above and the convex portion 110 provided on the vibrator 1. Thereby, as described above, the driving force can be efficiently generated by improving the current efficiency of the vibrator 1.

  Further, as described above, the piezoelectric motor 200 includes the piezoelectric actuator 100 and the rotor 210 that is driven (rotated) by the piezoelectric actuator 100. Therefore, the piezoelectric motor 200 includes the vibrator 1 as described above. Thereby, as described above, the driving force (rotational force) can be generated efficiently by improving the current efficiency of the vibrator 1.

(Manufacturing method of vibrator)
Next, a method for manufacturing the vibrator 1 will be described.
FIG. 7 is a flowchart for explaining a method of manufacturing a vibrator included in the piezoelectric motor (piezoelectric actuator) shown in FIG.

  As shown in FIG. 1, the method for manufacturing the vibrator 1 includes a substrate preparation step S10 and an element placement step S20. Hereinafter, each process will be described sequentially.

[Board preparation process]
In the substrate preparation step S10, the substrates 2 and 3 are prepared. Specifically, first, for example, a silicon substrate made of p-type or n-type silicon is prepared. Next, this silicon substrate is processed by etching so as to have a planar view shape of the substrate 2. Then, the second semiconductor part 26 is formed on one surface of the silicon substrate by doping with impurities by ion implantation and then performing an activation process by heat. At this time, when the p-type second semiconductor portion 26 is formed, the silicon substrate is composed of an n-type semiconductor, and an impurity such as boron (B) is used as an impurity, while the n-type second semiconductor portion 26 is formed. When formed, the silicon substrate is made of a p-type semiconductor, and an impurity such as phosphorus (P) is used. By forming the second semiconductor portion 26 in this way, the portion other than the second semiconductor portion 26 of the silicon substrate becomes the first semiconductor portion 25. Thereafter, the dielectric layer 24 is formed by thermally oxidizing the one surface of the silicon substrate. Thereby, the substrate 2 is obtained. Further, the wiring 61 is formed on the substrate 2 by a known film forming method.

  Further, the substrate 3 is obtained in the same manner as the substrate 2 except that the impurity doping and the heat treatment are omitted. Further, the wiring 62 is formed on the substrate 3 by a known film forming method.

  On the other hand, the piezoelectric material 4 is obtained by processing the bulk material of the piezoelectric body to form the piezoelectric body 42 and forming the first electrode 41 and the second electrode 43 using a known film forming method.

[Element placement process]
In the element arranging step S20, the piezoelectric element 4 is arranged on one surface side of the substrate 2. Specifically, the surface on the first electrode 41 side of the piezoelectric element 4 is bonded to the surface on the wiring 61 side of the substrate 2 with an adhesive. At this time, the substrate 2 and the piezoelectric element 4 are bonded in a state where the corresponding wiring 61 and the first electrode 41 are in contact with each other. Similarly, the surface on the second electrode 43 side of the piezoelectric element 4 is bonded to the surface on the wiring 62 side of the substrate 3 with an adhesive.

  The vibrator 1 is obtained as described above. The piezoelectric actuator 100 is obtained by bonding the convex portion 110 to the vibrator 1 with an adhesive.

  In the method for manufacturing the vibrator 1 described above, the substrate preparation step S10 for preparing the substrate 2 and the element arrangement in which the piezoelectric element 4 having the first electrode 41 that is an “electrode” is arranged on one surface side of the substrate 2. Step S20. The substrate 2 to be prepared in the substrate preparation step S10 is arranged on the first semiconductor unit 25 made of one of the p-type and n-type semiconductors and the first semiconductor unit 25, and is of p-type and n-type. And a second semiconductor portion 26 made of the other semiconductor. The element placement step S20 is a plan view as viewed from the direction in which the first semiconductor part 25 and the first electrode 41 that is an “electrode” overlap each other on the opposite side of the second semiconductor part 26 from the first semiconductor part 25. Thus, the piezoelectric element 4 is arranged so that at least a part of the first electrode 41 overlaps the second semiconductor portion 26. According to such a method of manufacturing the vibrator 1, the vibrator 1 having excellent current efficiency can be easily obtained as described above.

Second Embodiment
Next, a piezoelectric actuator according to a second embodiment of the present invention will be described.

  FIG. 8 is a sectional view showing a piezoelectric actuator according to the second embodiment of the present invention. FIG. 9 is a perspective view of a substrate provided in the piezoelectric actuator shown in FIG. In the following description, the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. 8 and 9, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  A piezoelectric actuator 100A shown in FIG. 8 includes two vibrators 1A each having a piezoelectric element 4A, and the surfaces on the piezoelectric element 4A side are bonded to each other via an adhesive 73 similar to the adhesives 71 and 72 described above. ing. Here, the two vibrators 1A have the same configuration as each other, and are configured to be symmetrical (a mirror image relationship).

  The vibrator 1 </ b> A includes a substrate 2 and a piezoelectric element 4 </ b> A disposed on the substrate 2. Here, the piezoelectric element 4A has a plurality of first electrodes 41, a piezoelectric body 42A, and a second electrode 43, which are stacked in this order. A protective layer 44 is provided on the outer surface of the piezoelectric element 4A. As a constituent material of the protective layer 44, for example, a silicone resin, an epoxy resin, a polyimide resin, or the like can be used. The protective layer 44 can be formed by using, for example, a spin coating method.

  Further, as shown in FIG. 9, a wiring 61 </ b> A including a plurality of wirings 61 a, 61 b, 61 c, 61 d, 61 e is disposed on one surface of the substrate 2. One end portions of the wirings 61a, 61b, 61c, 61d, and 61e are disposed on the vibrating portion 21 of the substrate 2 and also serve as the first electrodes 41a, 41b, 41c, 41d, and 41e of the piezoelectric element 4A. Such first electrodes 41a, 41b, 41c, 41d, and 41e can be formed together with the wirings 61a, 61b, 61c, 61d, and 61e by a known film forming method. The piezoelectric body 42A can be formed on the substrate 2 by a known film formation method (for example, sol-gel method) after the wiring 61A is formed.

  The current efficiency can also be improved by the second embodiment as described above. In the drawing, the surfaces of the two vibrators 1A on the piezoelectric element 4A side are joined together by the adhesive 73, but the faces of the two vibrators 1A on the substrate 2 side may be joined together by the adhesive 73.

<Third Embodiment>
Next, a piezoelectric actuator according to a third embodiment of the present invention will be described.

  FIG. 10 is a cross-sectional view showing a piezoelectric actuator according to a third embodiment of the present invention. FIG. 11 is a perspective view of a support substrate provided in the piezoelectric actuator shown in FIG. In the following description, the present embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted. 10 and 11, the same reference numerals are given to the same configurations as those in the above-described embodiment.

  A piezoelectric actuator 100B shown in FIG. 10 includes two vibrators 1B each having a piezoelectric element 4A, and a substrate 8 disposed therebetween, and these are the same adhesives as the adhesives 71 and 72 described above. 74 is joined. Here, the two vibrators 1 </ b> B have the same configuration as each other and are configured to be symmetrical (a mirror image relationship with each other).

  The vibrator 1B includes a substrate 2B and a piezoelectric element 4A disposed on the substrate 2B. Here, the substrate 2 </ b> B is configured by the vibration part 21 of the substrate 2 described above.

  As shown in FIG. 11, the substrate 8 connects the vibration part 81 joined to the piezoelectric element 4 </ b> A by an adhesive 74 and a pair of support parts 82 arranged with the vibration part 81 interposed therebetween. And six connecting portions 83. Here, each of the pair of support portions 82 is provided with a plurality of fixing holes 821, and these holes 821 are used to fix a member (not shown) with screws or the like. The vibration part 81 is supported by the pair of support parts 82 through six connection parts 83 so as to vibrate, and vibrates together with the piezoelectric element 4A. A convex portion 811 is provided at the tip of the vibration portion 81. As a constituent material of the substrate 8, the same material as that of the substrate 2 described above may be used, or a metal material may be used.

  The current efficiency can also be improved by the third embodiment as described above. In the drawing, the surface of the two vibrators 1B on the piezoelectric element 4A side is bonded to the substrate 8 by the adhesive 74, but the surface of the two vibrators 1B on the substrate 2B side is bonded to the substrate 8. 74 may be joined.

(robot)
Next, an embodiment of the robot of the present invention will be described.
FIG. 12 is a perspective view showing an embodiment of the robot of the present invention.

  The robot 1000 shown in FIG. 12 can perform operations such as feeding, removing, transporting and assembling precision instruments and parts (objects) constituting the precision equipment. The robot 1000 is a six-axis robot, and includes a base 1010 fixed to a floor or a ceiling, an arm 1020 rotatably connected to the base 1010, an arm 1030 rotatably connected to the arm 1020, and an arm 1030. An arm 1040 that is pivotally connected to the arm 1040, an arm 1050 that is pivotally coupled to the arm 1040, an arm 1060 that is pivotally coupled to the arm 1050, and a arm 1060 that is pivotally coupled to the arm 1060. An arm 1070 and a control unit 1080 that controls driving of the arms 1020, 1030, 1040, 1050, 1060, and 1070 are provided. Further, the arm 1070 is provided with a hand connection unit, and an end effector 1090 corresponding to an operation to be executed by the robot 1000 is attached to the hand connection unit. In addition, a piezoelectric motor 200 is mounted on all or a part of each joint portion, and the arms 1020, 1030, 1040, 1050, 1060, 1070 are rotated by driving the piezoelectric motor 200. The piezoelectric motor 200 includes any one of the piezoelectric actuators 100, 100A, and 100B. The driving of each piezoelectric motor 200 is controlled by the control unit 1080.

  The robot 1000 as described above includes the vibrator 1 as described above (including the piezoelectric motor 200). Thereby, the current efficiency of the vibrator 1 can be improved, and the characteristics of the robot 1000 can be improved.

(Electronic component conveyor)
Next, an embodiment of the electronic component carrying device of the present invention will be described.
FIG. 13 is a perspective view showing an embodiment of the electronic component carrying apparatus of the present invention. FIG. 14 is a perspective view of an electronic component holding unit provided in the electronic component transport apparatus shown in FIG. In the following, for convenience of explanation, the three axes orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis.

  An electronic component conveying apparatus 2000 shown in FIG. 13 is applied to an electronic component inspection apparatus, and includes a base 2100 and a support base 2200 disposed on the side of the base 2100. Further, on the base 2100, the upstream stage 2110 on which the electronic component Q to be inspected is placed and transported in the Y-axis direction, and the inspected electronic component Q is placed and transported in the Y-axis direction. A downstream stage 2120 and an inspection table 2130 that is located between the upstream stage 2110 and the downstream stage 2120 and inspects the electrical characteristics of the electronic component Q are provided. Examples of the electronic component Q include semiconductors, semiconductor wafers, display devices such as CLD and OLED, crystal devices, various sensors, inkjet heads, various MEMS devices, and the like.

  The support table 2200 is provided with a Y stage 2210 that can move in the Y-axis direction with respect to the support table 2200, and the Y stage 2210 can move in the X-axis direction with respect to the Y stage 2210. A stage 2220 is provided. The X stage 2220 is provided with an electronic component holder 2230 that can move in the Z-axis direction with respect to the X stage 2220.

  As shown in FIG. 14, the electronic component holding unit 2230 has a fine adjustment plate 2231 that can move in the X-axis direction and the Y-axis direction, and a rotation that can turn around the Z-axis with respect to the fine adjustment plate 2231. And a holding portion 2233 that is provided in the rotating portion 2232 and holds the electronic component Q. The electronic component holding unit 2230 includes a piezoelectric actuator 100 (100x) for moving the fine adjustment plate 2231 in the X-axis direction and a piezoelectric actuator 100 (100y) for moving the fine adjustment plate 2231 in the Y-axis direction. And a piezoelectric actuator 100 (100θ) for rotating the rotating unit 2232 around the Z-axis. Note that the piezoelectric actuators 100x, 100y, and 100θ may be the piezoelectric actuators 100A or 100B.

  The electronic component transport apparatus 2000 as described above includes the vibrator 1 as described above (including the piezoelectric actuators 100, 100A, and 100B). Thereby, the current efficiency of the vibrator 1 can be improved, and the characteristics of the electronic component transport apparatus 2000 can be improved.

  As described above, the vibrator and the manufacturing method thereof, the piezoelectric actuator, the piezoelectric motor, the robot, and the electronic component transport device of the present invention have been described based on the illustrated embodiment, but the present invention is not limited thereto. The configuration of each part can be replaced with any configuration having a similar function. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment suitably.

  In the above-described embodiment, the configuration in which the vibrator is applied to a robot or an electronic component transport apparatus has been described. However, the vibrator can be applied to various other electronic devices. Specifically, for example, the vibrator (piezoelectric actuator, piezoelectric motor) can be applied to a drive source of a paper feed roller of a printer, a drive source of an inkjet head of a printer, and the like.

DESCRIPTION OF SYMBOLS 1 ... Vibrator 1A ... Vibrator 1B ... Vibrator 2 ... Substrate 2B ... Substrate 3 ... Substrate 4 ... Piezoelectric element 4A ... Piezoelectric element 4a ... Piezoelectric element 4b ... Piezoelectric element 4c ... Piezoelectric Element, 4d ... piezoelectric element, 4e ... piezoelectric element, 5 ... spacer, 8 ... substrate, 10 ... drive circuit, 21 ... vibrating part, 22 ... supporting part, 23 ... connecting part, 24 ... dielectric layer, 25 ... first Semiconductor part 26 ... Second semiconductor part 31 ... Vibration part 32 ... Support part 33 ... Connection part 34 ... Dielectric layer 41 ... First electrode (electrode) 41a ... First electrode (electrode) 41b ... 1st electrode (electrode), 41c ... 1st electrode (electrode), 41d ... 1st electrode (electrode), 41e ... 1st electrode (electrode), 42 ... Piezoelectric body, 42A ... Piezoelectric body, 43 ... 2nd electrode 44 ... protective layer 61 ... wiring 61A ... wiring 61a ... wiring 61b wiring 61c wiring 61 ... wiring, 61e ... wiring, 62 ... wiring, 71 ... adhesive, 72 ... adhesive, 73 ... adhesive, 74 ... adhesive, 81 ... vibration part, 82 ... support part, 83 ... connection part, 100 ... piezoelectric actuator , 100A ... piezoelectric actuator, 100B ... piezoelectric actuator, 100x ... piezoelectric actuator, 100y ... piezoelectric actuator, 100θ ... piezoelectric actuator, 110 ... convex part, 142 ... fixed part, 143 ... connecting part, 200 ... piezoelectric motor, 210 ... rotor, 211 ... outer peripheral surface, 811 ... convex portion, 821 ... hole, 1000 ... robot, 1010 ... base, 1020 ... arm, 1030 ... arm, 1040 ... arm, 1050 ... arm, 1060 ... arm, 1070 ... arm, 1080 ... control unit 1090: End effector, 2000: Electronic parts conveyance Apparatus, 2100 ... Base, 2110 ... Upstream stage, 2120 ... Downstream stage, 2130 ... Inspection table, 2200 ... Supporting table, 2210 ... Y stage, 2220 ... X stage, 2230 ... Electronic component holder, 2231 ... Fine adjustment Plate, 2232 ... rotating part, 2233 ... holding part, Cp ... capacitor, Cs ... capacitor, L1 ... distance, L2 ... distance, O ... rotating shaft, Q ... electronic component, R ... resistor, S10 ... substrate preparation process, S20: Element placement process

Claims (12)

A substrate,
A piezoelectric element disposed on the substrate,
The piezoelectric element has an electrode between the substrate and
The substrate is
a first semiconductor portion composed of one of a p-type semiconductor and an n-type semiconductor;
Between the first semiconductor part and the electrode, joined to the first semiconductor, and arranged to overlap at least part of the electrode in a plan view as seen from the direction in which the first semiconductor part and the electrode overlap; and a second semiconductor portion made of the other of the p-type and n-type semiconductors.   The vibrator according to claim 1, further comprising a dielectric layer disposed between the substrate and the electrode.   The vibrator according to claim 2, wherein the second semiconductor part is disposed between the first semiconductor part and the dielectric layer. The first semiconductor part is composed of a p-type semiconductor,
4. The vibrator according to claim 1, wherein the second semiconductor portion is formed of an n-type semiconductor.   5. The vibrator according to claim 1, wherein the piezoelectric element has a piezoelectric body containing lead zirconate titanate.   The vibrator according to claim 5, wherein the piezoelectric body has a bulk shape.   The vibrator according to claim 1, wherein the electrode is electrically connected to a drive circuit that generates a drive signal for driving the piezoelectric element. The vibrator according to any one of claims 1 to 7,
And a convex portion provided on the vibrator.   A piezoelectric motor comprising the vibrator according to claim 1.   A robot comprising the vibrator according to claim 1.   An electronic component conveying apparatus comprising the vibrator according to claim 1. A substrate preparation process for preparing a substrate;
An element disposing step of disposing a piezoelectric element having an electrode on one surface side of the substrate,
The substrate prepared in the substrate preparation step is disposed on the first semiconductor unit and the first semiconductor unit composed of one of a p-type semiconductor and an n-type semiconductor, A second semiconductor part composed of the other semiconductor of
The element arranging step includes at least a part of the electrode in a plan view as viewed from a direction in which the first semiconductor part and the electrode overlap on the opposite side of the second semiconductor part from the first semiconductor part. Wherein the piezoelectric element is arranged so as to overlap the second semiconductor part.

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