JP2003070265A - Electrostatic actuator and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic actuator which is excellent in thrust performance consequently by narrowing the gap between the driver of a stator and a mover or an object to be moved. SOLUTION: In this electrostatic actuator, the base of a stator is provided with a step, and the driver composed of three electrodes is arranged at the upper stage of the board of the stator, and at least two out of three pieces of aggregate wirings are arranged at the lower stage of the board of the stator, and at the section where a plurality of aggregate wirings at the lower stage of the board cross one another, an insulator is interposed to prevent the short circuit between the aggregate wirings. The surface of the stator of the upper part of the driver is positioned equal to or higher than the surface of the stator on the lower stage of the board.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic actuator using an electrostatic force as a power source.

[0002]

2. Description of the Related Art Electrostatic actuators are roughly classified into two types: pulse drive induction charge type electrostatic actuators and AC drive double electrode type electrostatic actuators.

First, a pulse drive induction charge type electrostatic actuator will be described with reference to FIGS. Figure 1
1 is a schematic view of a pulse drive induction charge type electrostatic actuator. This electrostatic actuator includes a stator 1 and a mover 2.
It consists of two. The stator 1 has a large number of strip-shaped electrodes 3 wired in three phases, and its surface is covered with an insulating film 4. On the other hand, the mover 2 has the resistor layer 6 having a weak conductivity on the dielectric layer 5, and does not have a tooth-like structure such as an electrode.

The driving principle will be described with reference to FIGS. When driving, the mover 2 is placed on the stator 1, initial charging is performed, charges are accumulated in the mover 2, driving and recharging are repeated, and the mover 2 is driven stepwise.
Next, a more detailed description will be given. Initially, the mover 2 has no charge. First, as shown in FIG. 12, the electrode 3 of the stator 1 is
A voltage of (0, −V, + V) is applied to the electric field to induce electric charges on the mover 2 with a polarity opposite to that of the electrodes. As a result, the pattern of the electrodes 3 of the stator 1 is transferred onto the mover 2 as a charge pattern. When the charging is completed, the moving element 2 is attracted vertically downward and is strongly held by friction. Next, as shown in FIG. 13, the voltage is changed to (-V, + V,-).
V). As a result, the charges on the electrodes are exchanged instantaneously, but it takes a certain amount of time for the charge arrangement of the moving element 2 to change to a new equilibrium state, like the initial charging. The charge placement appears. At this time, the electric charge of the moving element 2 and the electric charge of the electrode 3 immediately below the moving element 2 have the same sign, so that a floating force acts on the moving element 2.
At the same time, a rightward driving force acts on the mover 2 due to the effect of the charges of the electrode 3 diagonally below, and as a result, the mover 2 is driven to the right by one electrode pitch as shown in FIG. Since the electric charge of the moving element 2 is lost during the driving, the thrust is reduced when the moving element 2 is continuously driven. Therefore, in the state where the mover 2 is stationary, the positive and negative voltages are applied to the electrodes 3 by shifting by one phase as shown in FIG. 15, and recharge is performed. After that, the electrodes 3 to which a voltage is applied are shifted one phase at a time, and the electrodes 3 shown in FIGS.
By repeating the steps of, continuous driving is performed.

Next, an AC drive double electrode type electrostatic actuator will be described with reference to FIGS. FIG. 16 is a schematic view of an AC driven dual electrode type electrostatic actuator.
This electrostatic actuator is composed of two parts, a stator 1 and a mover 2. Both the stator 1 and the mover 2 have a large number of strip electrodes 3 connected in three phases, and their surfaces are covered with an insulating film 4. One three-phase sine wave is applied to both the stator 1 and the mover 2 so that the connection order is opposite. As a result, a sinusoidal electric potential distribution 7 is generated on the stator 1 and the mover 2 in opposite directions.
The actuator is driven by the electrostatic force acting between these two potential distributions.

When the above electrostatic actuator is actually manufactured, the stator 1 is used in the case of a pulse drive induction charge type electrostatic actuator, and the stator 1 is used in the case of an AC drive double electrode type electrostatic actuator. As shown in the plan view of FIG. 9 and the side view of FIG. 10, it is necessary to form the first electrode 3a, the second electrode 3b, and the third electrode 3c on the moving element 2 and the moving element 2, respectively. As the arrangement of the electrode collective wiring 8b and the third electrode collective wiring 8c, an insulating layer 13 is installed as shown in FIG. 9 and FIG. As one of the methods, there is proposed a manufacturing method described in Japanese Patent Laid-Open No. 7-255185, in which multiple layers are formed via an adhesive layer and an insulating layer.

[0007]

In the electrostatic actuator, the force for driving in the horizontal direction, that is, the thrust is the most important characteristic. In order to increase the thrust, narrowing the gap between the stator 1 and the mover 2 is an effective means. However, simply, on the surface of the substrate 9, the first electrode 3a, the second electrode 3b, and the third electrode 3c, which are belt-shaped electrodes for driving, and the first electrode collective wiring 8a and the second electrode collective wiring 8b, which are the collective wiring thereof, are formed. , The third electrode collective wiring 8c, and the insulating layer 13 for preventing a short circuit between the second electrode collective wiring 8b and the third electrode collective wiring 8c are formed into a multilayer structure, the insulating layer 13 is an electrode for driving. The first electrode 3a, the second electrode 3b, and the third electrode 3c have a shape protruding from the surface. Then, when the stator 1 and the mover 2 are opposed to each other, the insulating layers 13 interfere with each other, so that the stator 1
The gap between the moving element 2 and the moving element 2 cannot be narrowed, which is an obstacle to increasing the thrust.

The present invention has been made to solve the above problems, and it becomes possible to narrow the gap between the drive portion of the stator 1 and the moving element 2 (or the object to be moved), resulting in thrust performance. To provide an excellent electrostatic actuator.

[0009]

In order to solve the above problems, the present invention has at least a stator, and three electrodes are provided on the surface of the base of the stator, and a voltage from a power source is applied to each of the three electrodes. And three insulating wires for applying a voltage, and an insulating film formed so as to cover the electrodes and the collective wire,
In an electrostatic actuator that moves an object or a mover arranged on a stator by applying a voltage to a driving unit including the three electrodes, a step is provided on a base of the stator, and the three electrodes are provided. The drive unit consisting of is arranged on the upper stage of the base body of the stator, and at least two of the three collective wirings are connected to the base body of the stator via an insulating layer in order to prevent a short circuit between the collective wirings. Electrostatically characterized in that it is disposed in the lower stage, and the stator surface above the drive unit is at the same height or higher position as the stator surface above the lower stage of the base on the stator surface. Provide an actuator. As a result, it is possible to reduce the distance between the drive unit of the stator and the object or the mover arranged on the stator while preventing a short circuit of the collective wiring, and it is possible to obtain high thrust.

In a preferred aspect of the present invention, the base body of the stator is made of a rigid material. By doing so, the step can be freely formed by grinding and polishing.

In a preferred aspect of the present invention, the step portion is provided in a step shape. This makes it possible to reduce the distance between the drive unit of the stator and the object or the mover arranged on the stator while preventing a short circuit of the collective wiring, and it is possible to obtain high thrust. It becomes easy to form electrodes by printing, patterning by vapor deposition + etching, patterning by plating + etching, and the like.

In a preferred aspect of the present invention, the step is formed in a slope shape. This makes it possible to reduce the distance between the drive unit of the stator and the object or the mover arranged on the stator while preventing a short circuit of the collective wiring, and it is possible to obtain high thrust. It becomes easy to form electrodes by printing, patterning by vapor deposition + etching, patterning by plating + etching, and the like.

In a preferred aspect of the present invention, the upper edge of the step and / or the end of the upper surface of the stator is chamfered.
This makes it easier to form electrodes by printing, patterning by vapor deposition + etching, patterning by plating + etching, and the like. Further, the “chamfer” referred to here may be either C chamfer or R chamfer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION First, the definitions of terms used in the present invention will be explained. In the present invention, the “base of the stator” refers to the entire supporting portion for disposing the driving portion and the collective wiring. It may be a substrate made of a single material or a substrate made of a plurality of materials. Further, the “step” refers to a height difference intentionally provided on the upper surface of the stator base material. Therefore, not only the step shape, but also the continuous slope or slope shape is included. Further, the “upper part” means a position above the “lower part”, which is an opposing position.
The part may be horizontal or may be inclined. Further, the "lower step portion" means a position below the "upper step portion", which is the opposite position. The part may be horizontal or may be inclined. Further, the "insulating coating" means a coating formed on the surface of the stator for protecting the electrodes and the collective wiring, and its material is preferably polyimide, alumina, aluminum nitride or the like. Further, the "insulator" in claim 1 means an insulator interposed between a plurality of collective wirings so as to prevent a short circuit between the collective wirings, for example, polyimide, alumina, Aluminum nitride or the like can be preferably used. The material of this "insulator" is "insulating film"
May be the same or different. In addition, the "insulator" may be interposed in a layered manner in the lower part of the stator base material, or the collective wiring may be pre-coated with an insulator. The rigid material means a material such as a thin film material that does not easily deform even when the weight of the material itself or external stress is applied, and specifically, such as ceramics, glass, and plastics. A sheet-like bulk body having a thickness of several to several tens of mm is preferably used.

A preferred embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view of a first embodiment according to the present invention, and FIG. 2 is a side view of the first embodiment according to the present invention. In the figure, a first electrode 3a and a second electrode 3 which are three strip electrodes are provided on a base body 9 of a stator 1.
b, a third electrode 3c, and a first electrode collective wiring 8a, a second electrode collective wiring 8b, and a third electrode collective wiring 8c, which are three collective wirings for applying a voltage from a power source to each of the three electrodes.
An insulating layer 13 for preventing a short circuit between the second electrode collective wiring 8b and the third electrode collective wiring 8c is formed. A step portion 12 is provided on the surface of the stator base 9, and the insulating layer 13 is provided on the lower step portion 10 of the first electrode 3 which is three strip electrodes.
A drive unit including a, the second electrode 3b, and the third electrode 3c is provided in the upper step portion 11. The upper surface of the insulating layer 5 is located below the drive section. When a voltage is applied to the drive unit, when the object is placed above it in a floating manner, the object obtains thrust and moves in the horizontal direction. Here, since the upper surface of the insulating layer 13 is located below the drive unit, the gap between the drive unit and the mover 2 can be set small, so that the thrust force per unit applied voltage is reduced. Can be increased.

As the material of the stator base 9, an insulating material such as ceramics or glass is used. Thickness is several tens of μ
Change from m to several tens of mm as necessary depending on the required rigidity and the like. First electrode 3a, second electrode 3b, third electrode 3c, first electrode collective wiring 8a, second electrode collective wiring 8
b, as the material of the third electrode collective wiring 8c, an electrode material such as gold, silver, platinum, copper, aluminum, titanium, tungsten, molybdenum, TiC, or ITO is used. Manufacturing methods include plating, PVD, CVD, printing, transfer, etc.
Adopt a manufacturing method according to the material. The thickness is 0. Adjust from several μm to several tens of μm according to the material and manufacturing method. As the material of the insulating layer 13, an insulating material such as ceramics, glass, or polyimide is used. PVD,
A manufacturing method suitable for the material is adopted, such as CVD, printing, a sol-gel method, and a thermal spraying method. The thickness is adjusted to several μm to several hundreds μm according to the material and the manufacturing method. For the insulating film 4, the same material and manufacturing method as the insulating layer 13 can be used.

FIG. 2 shows a side view of the first embodiment according to the present invention. Lower step portion 1 on which insulating layer 5, second electrode collective wiring 8b, and third electrode collective wiring 8c are previously formed by grinding or the like.
0 is set to be lower than the upper portion 11 by, for example, several μm to several hundreds μm. After that, the first electrode 3a, the second electrode 3b, the third electrode 3c, the first electrode collective wiring 8a, the second electrode collective wiring 8b, the insulating layer 13, and the third electrode collective wiring 8c are sequentially formed. And finally, the insulating film 4 is formed. As a result, while preventing the short circuit of the collective wiring, there is no part protruding from the drive part of the stator, so the distance between the drive part of the stator and the object or mover arranged on the stator should be shortened. It becomes possible to obtain a high thrust.

FIG. 3 shows a plan view of a second embodiment according to the present invention, and FIG. 4 shows a side view. The step portion 12 and / or the insulating layer 13 are provided in a stepwise shape of, for example, several μm to several tens of μm. As a result, while preventing the short circuit of the collective wiring, there is no part protruding from the drive part of the stator, so the distance between the drive part of the stator and the object or mover arranged on the stator should be shortened. It becomes possible to obtain a high thrust.

FIG. 5 shows a plan view of a third embodiment according to the present invention, and FIG. 6 shows a side view. The stepped portion 12 and / or the corner of the insulating layer 13 is chamfered. As a result, while preventing the short circuit of the collective wiring, there is no part protruding from the drive part of the stator, so the distance between the drive part of the stator and the object or mover arranged on the stator should be shortened. It becomes possible to obtain a high thrust.

FIG. 7 shows a plan view of a fourth embodiment according to the present invention, and FIG. 8 shows a side view. The stepped portion 12 and / or the corner of the insulating layer 13 is formed into a slope shape of, for example, several degrees to several tens of degrees. As a result, while preventing the short circuit of the collective wiring, there is no part protruding from the drive part of the stator, so the distance between the drive part of the stator and the object or mover arranged on the stator should be shortened. It becomes possible to obtain a high thrust.

FIG. 9 is a plan view of the prior art, and FIG.
A side view is shown in. Although the short circuit of the collective wiring is prevented, there is a portion protruding from the drive portion of the stator.

[0022]

According to the present invention, it is possible to narrow the gap between the drive portion of the stator and the moving element or the object to be moved, and as a result, it is possible to provide an electrostatic actuator having excellent thrust performance. It will be possible.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment according to the present invention.

FIG. 2 is a side view of the first embodiment according to the present invention.

FIG. 3 is a plan view of a second embodiment according to the present invention.

FIG. 4 is a side view of a second embodiment according to the present invention.

FIG. 5 is a plan view of a third embodiment according to the present invention.

FIG. 6 is a side view of a third embodiment according to the present invention.

FIG. 7 is a plan view of a fourth embodiment according to the present invention.

FIG. 8 is a side view of a fourth embodiment according to the present invention.

FIG. 9 is a plan view of the related art.

FIG. 10 is a side view in the related art.

FIG. 11 is a side view of a pulse drive induction charge type electrostatic actuator.

FIG. 12 is a side view for explaining a driving principle of a pulse drive induction charge type electrostatic actuator.

FIG. 13 is a side view for explaining a driving principle of a pulse drive induction charge type electrostatic actuator.

FIG. 14 is a side view for explaining a driving principle of a pulse drive induction charge type electrostatic actuator.

FIG. 15 is a side view for explaining a driving principle of a pulse drive induction charge type electrostatic actuator.

FIG. 16 is a side view of an AC-driven double-electrode type electrostatic actuator.

[Explanation of symbols]

1 ... Stator, 2 ... Mover, 3 ... Strip-shaped electrode, 3a ... 1st
Electrode, 3b ... second electrode, 3c ... third electrode, 4 ... insulating film,
5 ... Dielectric layer, 6 ... Resistor layer, 7 ... Sinusoidal potential distribution, 8a ... First electrode collective wiring, 8b ... Second electrode collective wiring, 8c ... Third electrode collective wiring, 9 ... Base body, 10 ... Lower part, 11 ... Upper part, 12 ... Step part, 13 ... Insulating layer

Claims (5)

[Claims] 1. At least a stator, on the surface of a base of the stator, three electrodes, three collective wirings for applying a voltage from a power source to each of the three electrodes, the electrode and the An electrostatic actuator that has an insulating coating formed to cover the assembly wiring, and moves an object or a moving element arranged on a stator by applying a voltage to a driving unit formed of the three electrodes, A step is provided on the base of the stator, and the drive unit composed of the three electrodes is arranged on the upper stage of the base of the stator. At least two of the three collective wirings are connected to each other. In order to prevent a short circuit, the stator is disposed on the lower step of the base of the stator through an insulator, and the stator surface on the upper part of the drive unit is on the lower surface of the stator on the stator surface. Same height as the surface or higher An electrostatic actuator characterized in that 2. The electrostatic actuator according to claim 1, wherein the base body of the stator is made of a rigid material. 3. The electrostatic actuator according to claim 1, wherein the step is provided stepwise. 4. The electrostatic actuator according to claim 1, wherein the step has a slope shape. 5. The electrostatic actuator according to claim 1, wherein an upper edge portion of the step and / or an end portion of an upper surface of the stator is chamfered.