JPH0686570A - Narrow gap linear electrostatic microactuator - Google Patents

Abstract

PURPOSE:To obtain a large displacement and a strong force with a simple structure by opposing, at a narrow interval, comb structure ends of stationary electrodes to comb structure ends of a moving portion formed on both sides. CONSTITUTION:Both side ends of a moving portion 1 made of silicon, etc., are formed into comb structure ends 2, and comb structure ends 4 of stationary electrodes 3 made of glass, etc., are opposed to the respective comb structure ends 2. A parallel spring 5 made of silicon, etc., and a glass substrate 6 are provided for the moving portion 1 and the stationary electrodes 3, and connection terminal portions 7 that are connected to the comb structure ends 4 are provided on the stationary electrodes 3. The moving portion 1 is displaced when a voltage is applied. A stronger force can be output by increasing the number of comb teeth. The parallel spring 5 supports the electrodes 3 elastically, and provides a larger anisotropy of compliance. The glass substrates 6 serves to reduce the parasitic capacitance and increase the breakdown voltage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a narrow gap linear electrostatic microactuator. More specifically, the present invention relates to a new linear electrostatic microactuator useful as an actuator for micromachines in various fields such as electronics and medical electronics.

[0002]

2. Description of the Related Art In recent years, in various fields such as electronics and medical electronics, researches on micromachines and their fine elements have been vigorously pursued. In the development of these micromachines, how to configure the actuators such as the driving part has become an important issue, and some proposals for it have already been made.

For such an actuator, a structure having a finer structure and capable of easily extracting a larger displacement and a large generated force is desired, but any of the actuators proposed so far is desired. Many of them have complicated structures, and none of them are practically satisfactory in terms of simplification, high performance, and further miniaturization and miniaturization.

The present invention has been made in view of the above-mentioned circumstances, solves the drawbacks of conventional actuators for micromachines, has a simple structure and features of operation, and has a large displacement and a large displacement. It is an object of the present invention to provide a new linear microactuator capable of taking out generated force.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is arranged such that the comb-blade structure ends of a fixed electrode are opposed to each other at a narrow interval with the comb-blade structure ends provided at both ends of a movable part. A narrow gap linear electrostatic microactuator is provided. This actuator makes it possible to take out a larger force by utilizing a large electrostatic force, and is characterized by its simple structure.

Hereinafter, the linear electrostatic microactuator of the present invention will be described in more detail with reference to the accompanying drawings.

[0007]

FIG. 1 of the accompanying drawings illustrates a narrow gap linear electrostatic microactuator of the present invention. For example, as shown in FIG. 1, the linear electrostatic microactuator of the present invention is Comb blade structure ends (2) are formed on both ends of a movable part (1) made of silicon (Si) or the like, and a comb electrode structure end of a fixed electrode (3) made of glass or the like is formed so as to face each of them. (4) is provided. The movable part (1) and the fixed electrode (3) are provided with a parallel leaf spring (5) made of silicon or the like and a glass substrate (6). The fixed electrode (3) is also provided with a connection terminal portion (7) connected to the end (4) of the comb blade structure.

A plurality of linear actuators may be formed by disposing further movable parts on the fixed electrodes (3) on both sides and forming a facing relationship by the comb blade structure ends (2) and (4). . In this structure, the comb blade structure end (2) of the movable part (1) and the comb blade structure end (4) of the fixed electrode (3) are used.
The existence of a narrow gap between and makes use of a large electrostatic attraction, and in this structure,
The thickness of the movable part (1) can be increased so that a larger force can be taken out.

By applying a voltage, the movable part (1) becomes a linear actuator which is displaced in the X direction in the figure. In this case, a larger force can be obtained by increasing the number of comb blades. This increase in the number of comb blades can be achieved by etching as fine processing.

The parallel leaf springs (5) elastically support the electrodes, and the anisotropy of compliance also increases.
Further, by using the glass substrate (6), the parasitic capacitance is reduced and the pressure resistance is increased. Of course, in this structure, the position of the movable part (1) can be detected and controlled by measuring the electrostatic capacitance between the opposing electrodes. The position detecting electrode and the driving electrode may be the same or different.

For example, the linear electrostatic actuator of the present invention exemplified as the above structure can be manufactured as follows. Manufacturing of Movable Part (1) As illustrated in FIG. 2, both sides of a plate material (11) such as silicon are photo-etched to a depth of 1 μm or less, and further dicing or etching is performed to form a groove (12).

Manufacturing of Fixed Electrode (3) As illustrated in FIG. 3, a metal film (32) is vapor-deposited and / or plated on the surface of a plate material (31) such as glass, and dicing or etching is performed to form a groove (33). To form. Joining of the movable part (1) and the fixed electrode (3) As illustrated in FIG. 4, the movable part (1) and the fixed electrode (3).
Are anodically bonded to each other, the gap (8) is filled with resin, and then cut to a predetermined thickness and polished.

Photoetching of metal vapor deposition film, formation of interlayer insulating film, photoetching, photoetching of metal film,
And resin removal. Next, Au mask vapor deposition is performed on the surface. The bonded silicon of the silicon parallel leaf spring (5) is oxidized, photoetched into a predetermined pattern, and SiO ₂ is removed after the silicon etching is completed to manufacture.

The silicon parallel leaf spring (5) is anodically bonded to the glass substrate (6). As a result, for example, as shown in FIG. 5, the predetermined portions (A) and (B) of silicon are bonded to the glass substrate (6). Final Joining The joined body of the movable part (1) and the fixed electrode (3) obtained in FIG. 4 and the joined body of the silicon parallel leaf spring (5) and the glass substrate (6) obtained in FIG. , As shown in FIG. 6, anodic bonding and Au-Si eutectic bonding (Cr-Au,
And AuGe).

Next, dicing is performed at the positions (C) and (D) in the figure. Finally, leads are attached to complete the actuator of the present invention.

[0016]

As described in detail above, according to the present invention, a linear electrostatic actuator having a simple structure is realized, and the actuator is useful for precision positioning, displacement gauges and the like.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an actuator of the present invention.

FIG. 2 is a perspective cross-sectional view illustrating the manufacture of a movable part.

FIG. 3 is a perspective cross-sectional view illustrating the manufacture of a fixed electrode.

FIG. 4 is a perspective sectional view exemplifying joining of a movable portion and a fixed electrode.

FIG. 5 is a perspective view illustrating an example of joining a parallel leaf spring and a substrate.

FIG. 6 is a perspective view illustrating final joining.

[Explanation of symbols]

 1 Movable part 2 Comb blade structure end 3 Fixed electrode 4 Comb blade structure end 5 Parallel leaf spring 6 Substrate 7 Connection terminal part 8 Gap 11 Plate material such as silicon 12 Groove 31 Plate material such as glass 32 Metal film 33 Groove

Claims (1)

[Claims] 1. A comb blade structure end provided at both ends of a movable part,
A narrow gap linear electrostatic microactuator, characterized in that the fixed electrode comb blade structure ends are arranged facing each other with a narrow gap.