JPH04133226A - Electrostatic relay - Google Patents

Abstract

PURPOSE:To suppress the production costs and enhance the durability or the reliability against varying temp. by using an electroconductive material as the base board of a fixed electrode block, and thereby enabling simple and effective performance of processings. CONSTITUTION:A movable electrode block A and a fixed electrode block B are joined together by a joining means such as adhesive. The base board material of this movable electrode block A is isolated from the base board 60 of the fixed electrode block B by a Si dioxide film 16 of the movable electrode block A. Between these block A base board material and block B base board 60, a potential is generated by applying a voltage between drive electrodes 14, 50, which generates an electrostatic attraction force to cause a movable plate 20 to be attracted to the base board 60. As a result, a contact electrode 30 of this movable plate 20 is contacted to contact electrodes 40, 40 of the block B, and a contact circuitry is closed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrostatic relay, and more specifically, the present invention relates to an electrostatic relay, and more specifically, a relay that uses electrostatic force generated when a voltage is applied as a drive mechanism to open and close contacts. It concerns electrostatic relays.

[Conventional technology]

Electrostatic relays do not require an electromagnetic coil to generate electromagnetic force like conventional relays, and have the feature that the overall structure of the relay can be made extremely compact, with an element size of 10 mm or less. Research and development is progressing with the hope that it will become possible to manufacture relays as well.

FIGS. 7 and 8 show the structure of a conventional electrostatic relay. In FIG. 7, the electrode portion is cross-hunted to make it easier to distinguish it from other portions. The electrostatic relay is composed of a movable electrode block A, a fixed electrode block B, and a spacer block C which is integrally joined with the blocks A and B facing each other with a gap between them. The movable electrode block A is made of a silicon substrate, and the necessary structural parts are formed by processing this silicon substrate by microfabrication means such as selective etching.

The movable electrode block A includes a thin movable plate 20 connected to the frame part 10 through a thin T-shaped connecting part 12 at the center of a frame part 10 constituting the outer periphery. By elastically deforming the connecting portion 12, the other end side of the movable plate 20 pivots toward the fixed electrode block B side. On the surface of the movable plate 20 facing the fixed electrode block B, a U-shaped contact electrode 30 is formed along the outer periphery of the movable plate 20 from a protruding piece 22 that protrudes along the longitudinal side of the movable plate 20. . A fixed electrode block B is provided with a drive electrode 14 for applying a drive voltage to the movable plate 20 on the upper surface of the frame part 10.
is made of a flat glass material, and on its surface, contact electrodes 40 and 40 are formed at positions facing both ends of the U-shape of the movable side contact electrode 30, and contact electrodes 40 and 40 are formed at positions facing the movable plate 20. To explain the operation of the electrostatic relay as described above in which the fixed drive electrode 50 is formed, when a voltage is applied between the drive electrode 14 of the movable electrode block A and the drive electrode 50 of the fixed electrode block B, Electrostatic attraction is generated between the two, and the movable plate 20 is attracted to the fixed drive electrode 50. As a result, both ends of the contact electrodes 30 of the movable plate 20 come into contact with the fixed side contact electrodes 40, 40, and a contact circuit is closed. That is, the opening and closing of the output circuit connected to the contact electrodes 40, 40 can be controlled by inputting the voltage applied between the drive electrodes 14, 50.

In addition to the above, the structure of the electrostatic relay is basically the same as the above structure, but instead of providing a spacer block C, a square or other shape is provided on the opposing surface of the movable electrode block A or fixed electrode block B. A movable plate 2 is formed by forming a recess.
A structure in which a gap forming a contact gap is provided between the contact point B and the fixed electrode block B has also been proposed. If there is no spacer block C, the movable plate 20 and fixed electrode pro.

Since the spacing between B and B can be set accurately, the contact gap can be set with high precision, and the performance of the electrostatic relay can be improved.

As can be seen from the structure and operation of electrostatic relays explained above, electrostatic relays can be manufactured using semiconductor element manufacturing techniques such as photolithography, plate making technology, and microfabrication technology, so they are extremely It has many advantages, such as being able to manufacture small products, making it suitable for mass production, and generating less heat during operation.

[Problem to be solved by the invention]

However, in the electrostatic relay of the conventional structure described above, an electrically insulating substrate such as a glass material is used as the substrate of the fixed electrode block B, and drive electrodes and contact electrodes are formed on it. There was a problem in that it took time and effort to manufacture.

For example, in conventional electrostatic relays, drive electrodes and contact electrodes must be formed on each of the movable electrode block side and the fixed electrode block side, so at least four types of electrode patterns must be formed. The process was extremely complicated.

Further, since glass substrates and the like are materials that are extremely difficult to process, it is extremely difficult to cut minute patterns or perform etching processes that create steps of 1n or more. In particular, in a structure in which the spacer block C is not provided and the fixed electrode block B is provided with recesses, as in the conventional example described above, there is a drawback that the amount of etching processing increases and the processing time is extremely long. .

Furthermore, since the movable electrode block A is usually made of a silicon substrate, there is a large difference in thermal expansion coefficient from the fixed electrode block B made of a glass substrate, and if there is a drastic temperature change,
There was also the problem that the joints between the blocks would peel off or cracks would form at the joints.

Therefore, an object of the present invention is to provide an electrostatic relay as described above, which is easy to manufacture such as electrode block processing and electrode fabrication, and has excellent durability against temperature changes. .

[Means to solve the problem]

The electrostatic relay according to the present invention solves the above problems,
A movable electrode block and a fixed electrode block are arranged facing each other with an interval, and the movable electrode block includes a movable plate whose one end is movably supported, and a contact electrode provided on the surface of the movable plate on the side of the fixed electrode block. The fixed electrode block includes a drive electrode for applying a voltage to the movable plate, and the fixed electrode block includes an electrostatic drive section provided at a position facing the movable plate, and an electrostatic drive section provided at a position facing the movable side contact electrode. In an electrostatic relay equipped with a contact electrode, the substrate constituting the fixed electrode block is made of a conductive material, and the parts of the fixed electrode block that require insulation are made of an insulating material.

The basic structure of the movable electrode block and fixed electrode block is the same as that of a normal electrostatic relay. As for the shape and support structure of the movable plate of the movable electrode block, any structure can be adopted as long as it can operate as an electrostatic relay as described above. The arrangement structure of the contact electrodes formed on the movable electrode block and the fixed electrode block or the drive electrodes of the movable electrode block may be the same as in the case of a normal electrostatic relay.

In this invention, the substrate material constituting the movable electrode block is the same as a semiconductor substrate material such as a silicon substrate as in a normal electrostatic relay, but the substrate material constituting the fixed electrode block is A conductive material such as a silicon substrate is used instead of a glass substrate as used in electrostatic relays. Here, the conductive material includes not only a conductor in a narrow sense, but also a semiconductor as long as it can function as an electrostatic drive unit, which will be described later. The parts of the fixed electrode block that require insulation are made of an insulating material. Specifically, if the entire fixed electrode block is made of a conductive material and an insulating film such as a silicon oxide film or a silicon nitride film is formed using normal thin film forming methods only in the areas where insulation is required. good. A structure may also be used in which a member made of an insulating material is bonded to a part of a substrate made of a conductive material. It is preferable that the portions of the fixed electrode block that require a large amount of etching or fine cutting be made of a conductive material.

When forming contact electrodes on the surface of a fixed electrode block, the contact electrodes can be insulated and isolated by forming an insulating film on the surface of a substrate made of a conductive material and producing the contact electrodes thereon.

In the fixed electrode block, the electrostatic drive section that faces the movable plate and generates electrostatic force therebetween is preferably constructed from a substrate itself made of a conductive material. That is,
If a voltage can be applied between the movable plate of the movable electrode block and the substrate facing the movable plate, the movable plate of the movable electrode block can be used as an electrostatic drive unit that attracts the movable plate of the movable electrode block with electrostatic attraction. It can perform its functions. In this case, unlike conventional electrostatic relays, there is no need to form a drive electrode with a large area as an electrostatic drive section using a thin film forming means or the like.

In order to apply voltage to the substrate of the fixed electrode block, it is possible to form a drive electrode on a part of the substrate for connection to an external circuit, or to connect the terminal of the external circuit directly to the substrate itself. can.

[For production]

If the substrate constituting the fixed electrode block is made of a conductive material, microfabrication such as etching can be easily performed compared to conventional glass plates or the like. For example, it is possible to easily manufacture a structure in which a fixed electrode block is provided with recesses without using a spacer block, as in the conventional example described above.

A substrate made of a conductive material can itself be used as an electrostatic drive unit. This is because if a voltage is applied between the movable plate and the substrate facing the movable plate, an electrostatic force is generated between the movable plate and the substrate, which can attract the movable plate to the substrate, and the fixed electrode block substrate itself. performs the same function as the drive electrode in a conventional electrostatic relay. As a result, the effort and cost of producing drive electrodes on the fixed electrode block can be reduced.

The substrate made of conductive material has a coefficient of thermal expansion similar to that of the movable electrode blocks, which are usually made of silicon substrates, so even if there are large temperature changes during use, the bonding between the movable electrode block and the fixed electrode block will not occur. No parts will peel off or crack.

〔Example〕

Next, embodiments of the present invention will be described below with reference to the drawings.

Figures 1 and 2 show the overall structure of an electrostatic relay, and the electrostatic relay consists of a movable electrode block A and a fixed electrode block B.
are integrally joined in such a way that they face each other. FIGS. 3 and 4 show the structures of opposing surfaces of the movable electrode block A and the fixed electrode block B, respectively.

The movable electrode block A is made of a silicon substrate, and is provided with a thin plate-shaped movable plate 20 connected to the frame part 10 via a thin T-shaped connecting part 12 at the center of a frame part 10 forming the outer periphery. The movable plate 20 is provided with a protruding piece 22 that protrudes along its longitudinal side, and the thickness of the movable plate 20 is formed to be an appropriate thickness for the movable plate 20 to pivot due to electrostatic attraction, for example, about 30 Ira. has been done. The above structure on the movable electrode block is processed by anisotropic etching. The surface of the movable electrode block A facing the fixed electrode block B is covered with a silicon dioxide film 16. On the surface of this silicon dioxide film 16, a contact electrode 30 is provided in a U-shape from the protrusion piece 22 of the movable plate 20 along the outer peripheral piece of the movable plate 20. Also, on the opposite side of the movable electrode block A, the upper surface of the frame portion 10 is covered with a silicon dioxide film 16, and the drive electrode 1 is placed on the silicon dioxide film 16.
4 is formed. A portion of the drive electrode 14 penetrates the silicon dioxide film 16 and is electrically connected to the substrate surface, so that a voltage can be applied from the drive electrode 14 to the movable plate 20 through the substrate. Contact electrode 30
The drive electrode 14 is manufactured by ordinary electrode forming means such as vapor deposition or pattern etching.

Next, the solid electrode block B has a silicon substrate 6 as a whole.
Of the substrate 6o, the movable plate 20
A rectangular recess 62 is dug by anisotropic etching at a position facing the .

The depth of the recess 62 is such that an appropriate contact gap is formed between the movable plate 2o and the substrate 6o, for example, 10μ.
It is set to a certain degree. The portion where the recessed portion 62 is formed in the substrate 6o becomes an electrostatic drive portion that faces the movable plate 2o.

A contact electrode 40 is formed on the surface of the substrate 60 with a silicon dioxide layer 42 interposed therebetween. The contact electrode 40 extends from the bottom surface of the recess 62 facing the U-shaped ends of the movable contact electrode 3o to the top surface via the side wall, and has a generally angular shape. The silicon dioxide layer 42 is slightly larger than the contact electrode 4o and is provided to electrically isolate the surface of the substrate 60 and the contact electrode 4o. silicon dioxide layer 4
2 is fabricated by a thermal oxidation method and an etching method, and the contact electrode 40 is fabricated by a normal electrode forming method such as a vapor deposition method or an etching method.

The movable electrode block A and the fixed electrode block B are integrally joined by a joining means such as an adhesive. The substrate material of the movable electrode block A and the substrate 60 of the fixed electrode block B are insulated and isolated by the silicon dioxide film 16 of the movable electrode block A.

The operation of the electrostatic relay having the above structure will be explained. By applying a voltage between the drive electrodes 14 and 50, a potential is generated between the substrate material to the movable electrode block and the substrate 60 of the fixed electrode block B, and electrostatic attraction is generated, causing the movable plate 20 to touch the substrate. 60, and as a result, the contact electrode 30 of the movable plate 20 is attracted to the contact electrode 4 of the fixed electrode block B.
0.40 and the contact circuit is closed. If the voltage applied between the drive electrodes 14 and 50 is eliminated (the electrostatic force will also disappear,
The deformation in the connecting portion 12 of the movable plate 20 is resiliently recovered, the movable plate 20 returns to its original position, and the contact circuit is opened.

Next, FIG. 5 and FIG. 6 show another embodiment. The basic structure is the same as that of the previous embodiment. however,
In this embodiment, the drive electrode 50 is not provided on the fixed electrode block B, and the drive electrode lead terminal 70 is directly connected to the fixed electrode block B.
It is connected to the back surface of a substrate 60 made of a conductive material by using a conductive paste or gold eutectic to bond it. For the contact electrodes 40, 40 of the fixed electrode block B and the drive electrodes 14 of the movable electrode block A, wires 78, 74 made of ordinary gold wire or the like are used to connect the respective lead terminals 76.
．． It is connected to 72 by wire bonding.

In this embodiment, a drive electrode 50 is placed on the fixed electrode block B side.
Since there is no substrate 6, the effort required for electrode production is reduced.
By making the connection between 0 and the lead terminal by die bonding, the effort of wire bonding can be saved.

〔Effect of the invention〕

According to the electrostatic relay according to the present invention described above,
By using a conductive material as the substrate material of the fixed electrode block, processing can be performed more easily and efficiently than with conventional glass substrates. As a result, the shape and structure of the fixed electrode block can be freely designed, making it possible to improve the functionality and performance of the electrostatic relay, while increasing production efficiency and reducing manufacturing costs. In particular, it has become possible to easily and accurately manufacture electrostatic relays with a structure in which the contact gap is formed by making recesses in the fixed electrode block without providing spacers, improving the performance of electrostatic relays. can make a major contribution to

Furthermore, the substrate itself can be used as an electrostatic drive section, and the effort and cost of manufacturing a wide drive electrode that becomes the electrostatic drive section can be reduced. As a result, the overall production efficiency of electrostatic relays can be increased and production costs can be reduced.

Furthermore, since the difference in thermal expansion coefficient between the movable electrode block and the fixed electrode block is reduced, the durability and reliability of electrostatic relays against temperature changes can be increased, contributing to the expansion of applications and demand for electrostatic relays. be able to.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the electrostatic relay according to the present invention, FIG. 2 is a sectional view, FIG. 3 is a bottom view of a movable electrode block, FIG. 4 is a plan view of a fixed electrode block, and FIG. The figure is a sectional view showing another embodiment, FIG. 6 is a plan view with the movable electrode block removed, FIG. 7 is a plan view of the conventional example, and FIG. 8 is a plan view of the conventional example.
The figure is a sectional view. A...Movable electrode block 14...Drive electrode 20
...Movable plate 30...Contact electrode B...Fixed electrode block 40...Contact electrode 50...Drive electrode
60... Board Figure 1 Agent Patent Attorney Takehiko Matsumoto Figure 2 Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] 1. A movable electrode block and a fixed electrode block are arranged to face each other, and the movable electrode block includes a movable plate whose one end is movably supported, and a movable plate provided on the surface of the movable plate on the fixed electrode block side. The fixed electrode block includes a drive electrode for applying a voltage to the contact electrode and the movable plate, and the fixed electrode block includes an electrostatic drive section provided at a position facing the movable plate, and a position facing the movable side contact electrode. In an electrostatic relay comprising a contact electrode provided at Characteristic electrostatic relay. 2. The electrostatic relay according to claim 1, wherein the conductive material of the substrate constituting the fixed electrode block is made of silicon, and the insulating material is made of at least one of a silicon oxide film and a silicon nitride film. 3. The electrostatic relay according to claim 1 or 2, wherein the electrostatic drive section of the fixed electrode block is composed of a substrate itself made of a conductive material.