JP2001068006A - Micro relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay, securing initial gap required for insulation and enhanced in contact pressure without increasing the drive voltage by composing a movable board with a first moving piece cut out by forming a slit and a second moving piece formed in a first moving piece and less elastically deformable than the first movable piece and forming a moving contact on the lower surface of a second movable piece. SOLUTION: When electrostatic attraction is generated by applying a voltage between a fixed board 10 and a movable electrode 23, the movable electrode 23 which is easier to elastically deform than a second moving piece 27 is attracted to the fixed board 10 side and bent. Thereby, even after a moving contact 28 is lowered and abuts on fixed contacts 14b, 17b, the distance between the fixed board 10 and the movable electrode 23 is reduced, so that larger electrostatic attraction is generated between them. The movable electrode 23 further approaches the fixed board 10 and is attracted by the fixed board 10. As a result, the second moving piece 27 is bent to provide large contact pressure, and a signal is transmitted stably between signal wires 14a, 17a. Preferably, the movable electrode (first moving piece) is formed into a counterswastika- shaped form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a micro relay.

[0002]

2. Description of the Related Art Conventionally, a micro relay, particularly an electrostatic drive type micro relay, has a larger driving force than a heat drive type micro relay having the same external dimensions, drive voltage, and contact interval. It is hard to get strength. For this reason, it is necessary to increase the facing area of the opposing drive electrodes and reduce the distance between the drive electrodes. For example, the driving force generated at the initial stage of driving the driving electrodes is inversely proportional to the square of the distance between the opposing driving electrodes. Therefore, in order to drive at a low drive voltage, it is necessary to reduce the distance between the drive electrodes. The contact pressure of the contact is determined by the difference between the electrostatic attraction between the drive electrodes during operation and the spring force of the drive electrodes. The electrostatic attraction between the driving electrodes during operation is determined by the distance between the driving electrodes. Therefore, when trying to obtain a desired contact pressure,
It is necessary to reduce the distance between the drive electrodes during operation.

However, when the distance between the opposing drive electrodes is reduced, the contacts also approach each other, so that not only is it difficult to dispose the contacts on the opposing surface of the drive electrodes, but also the withstand voltage between the drive electrodes is reduced. For this reason, there is a limit to improving the operation characteristics by reducing the distance between the drive electrodes.

On the other hand, in order to increase the electrostatic attraction, it is conceivable to use a charging material such as an electret which is easily charged. However, there is a problem that the electret lacks stability and is not practical.

[0005] In view of the above problems, an object of the present invention is to provide a micro relay capable of securing an initial gap necessary for insulation and increasing a contact pressure without increasing a driving voltage.

[0006]

According to the present invention, there is provided a micro-relay which includes a movable substrate opposed to a fixed substrate and a voltage generated by applying a voltage between the two substrates. The movable substrate is driven by an attractive force, and a movable contact formed on the lower surface of the movable substrate is brought into contact with and separated from a pair of fixed contacts arranged side by side on the upper surface of the fixed substrate, so that signal wiring extending from each fixed contact is separated. In the micro relay for conducting / interrupting, the movable substrate is provided with a first movable piece cut out by providing a slit, and a second movable piece is formed in the first movable piece and is less elastically deformable than the first movable piece. A movable piece is provided, and the movable contact is provided on a lower surface of the second movable piece.

With this configuration, at the beginning of driving, the first movable piece is driven first, and after the movable contact comes into contact with the fixed contact,
The first movable piece is attracted to the fixed substrate.

[0008] The first movable piece may be formed in a substantially swastika shape on a plane. With this configuration, the first movable piece moves up and down perpendicularly to the plate thickness direction.

A second movable piece may be cut out by arranging a pair of slits in the first movable piece, or the second movable piece may be formed by partially thinning the first movable piece. You may. With these configurations, it is possible to form a second movable body that is integral with the first movable piece.

Further, a concave portion may be formed on at least one of the opposing fixed substrate and the movable substrate, and a contact may be arranged on the bottom surface of the concave portion. According to this configuration, by providing the recess on the facing surface and providing the contact on the bottom surface, the height of the contact can be substantially reduced, and the distance between the opposing drive electrodes can be further reduced. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the accompanying drawings of FIGS. The micro relay according to the first embodiment includes a fixed substrate 10, a movable substrate 20, and a cap 30, as shown in FIGS.

As shown in FIGS. 1 and 3, the fixed substrate 10 has a sheet shape and constitutes a fixed electrode by itself. That is, a recess 11 is formed on the upper surface of the fixed substrate 10, and a recess 12 is formed at the center of the recess 11. The entire upper surface of the fixed substrate 10 is covered with the insulating oxide film 13. Further, on the upper surface of the fixed substrate 10, wire bonding pads 14, 15, 1 are formed by sputtering, vapor deposition, plating, screen printing, or the like.
6, 17, signal wirings 14a, 17a, and connection pods 18a, 18b, 18c are formed. The signal wirings 14a and 17a are fixed contacts 14b and 17b whose one ends are arranged at predetermined intervals. Further, the pad 15 is formed with a through hole 15 a that is electrically connected to the fixed substrate 10. Further, one end of the signal line extended from the pad 16 serves as a connection pad 16a. On the other hand, a recess 19 is formed in a portion of the lower surface of the fixed substrate 10 located immediately below the recess 12 to have a thin structure (see FIG. 7A). This is because elastic deformation is easy.

As shown in FIGS. 1 and 2, the movable substrate 20 has a sheet shape having an insulating oxide film 21 formed on the entire lower surface thereof, and can be bent by arranging a pair of slits 22 and 22 side by side. The movable electrode 23 (first movable piece) is cut out. Further, a pair of slits 26, 26 are formed in the center of the movable electrode 23, and a second movable piece 27 is cut out. A conductive layer 24 is formed on a portion of the lower surface of the insulating oxide film 21 located below the movable electrode 23 and a portion corresponding to the connection pod 18a of the fixed substrate 10. This conductive layer 24
The connection portion 24a connected to the connection pad 16a of the fixed substrate 10 extends. Further, an insulating layer 25 is formed on a portion of the lower surface of the conductive layer 24 located below the movable electrode 23. A movable contact 28 is provided at the center of the insulating oxide film 21 exposed from the lower surface of the second movable piece 27.

As shown in FIG. 1, the cap 30 is in the form of a sheet which can be placed on the upper surface of the fixed substrate 10, and has a recess 31 formed on the lower surface for accommodating the entire movable substrate 20.

Next, a method of manufacturing a micro relay having the above-described structure will be described. First, a recess 11 is formed on the upper surface of a silicon wafer 100 for a fixed substrate (fixing wafer) 100 shown in FIG. 4A, and then a recess 12 is formed in the center thereof (FIG. 4B). Then, the upper surface of the fixing wafer 100 is covered with the insulating oxide film 13 (FIG. 4C). Further, as shown in FIG.
Pad 1 for bonding by plating, screen printing, etc.
4, 15, 16, 17, signal wirings 14a, 17a, fixed contacts 14b, 17b, and connection pods 18a, 1
By forming 8b and 18c, the fixed substrate 10 is completed.

On the other hand, the lower surface of the movable substrate silicon wafer (movable wafer) 101 shown in FIG.
1 (FIG. 5B). Then, as shown in FIG. 5C, sputtering, vapor deposition, plating, and screen printing are performed on the lower surface of the insulating oxide film 21 except for the opposing edges and the portion that becomes the second movable piece 27. Thus, the conductive layer 24 made of Au / Cr, the connection portion 24a, and the movable contact 28 are formed. Further, an insulating film 29 is formed on a portion of the lower surface of the conductive layer 24 located below the second movable piece 27.

Next, as shown in FIG. 6A, the movable wafer 101 is overlapped on the fixed substrate 10 and positioned.
A part of the conductive layer 24 is joined and integrated with the joining pod 18a of the fixed substrate 10. At the same time, the connection portion 24a of the conductive layer 24 is connected to the connection pad 16a of the wire bonding pad 16. Then, a concave portion 19 is formed in the center of the lower surface of the fixed substrate 10 (FIG. 6B), and the fixed contact 14 is formed.
b and 17b are thinned immediately below. Next, the upper surface of the movable wafer 101 is deleted, and the thickness is reduced to a thickness that functions as a movable electrode (FIG. 6C). Then, the movable wafer 101 is etched to form the slits 22 and 22 and the slits 26 and 26, so that
The second movable pieces 23 and 27 are cut out. At the same time, the peripheral edges of the movable wafer 101 are also appropriately etched so that the bonding pads 14, 15, 16, 1 are formed.
7 and fixed substrate 1 for joining cap 30
0 is exposed (FIG. 7A). In the present embodiment, since the movable substrate 20 is formed in a state where the movable substrate 20 is joined and integrated with the fixed substrate 10, the movable substrate 20 is not deformed during the production and no residual stress is generated. Then, the cap 30 in which the recess 31 is formed is positioned on the fixed substrate 10, joined and integrated and sealed to complete the micro relay.

Next, the operation of the micro relay having the above configuration will be described. That is, when no voltage is applied to the fixed substrate 10 and the movable electrode 23, no electrostatic attraction is generated. Therefore, the movable electrode 23 is kept horizontal by its own elastic force. As a result, the movable contact 28
Are separated from the fixed contacts 14b and 17b.

The wire bonding pad 1
A voltage is applied between the substrate 10 and the movable electrode 23 via 5, 5 to generate an electrostatic attraction. As a result, the movable electrode (first movable piece) 23 that is more easily elastically deformed than the second movable piece 27 is sucked toward the fixed substrate 10 and curved. Therefore, the movable contact 28 descends, and the fixed contacts 14b, 17b
Contact At the same time, the spring forces of both the movable electrode 23 and the second movable piece 27 are combined and act as a reaction force. Further, even after the movable contact 28 comes into contact with the fixed contacts 14b and 17b, the distance between the fixed substrate 10 and the movable electrode 23 is reduced, and a larger electrostatic attraction is generated between the two. That is, the electrostatic attraction increases in inverse proportion to the square of the distance.
Since the fixed contacts 14b and 17b are formed on the bottom surface of the concave portion 12 and are low, the movable electrode 23 can be brought closer to the fixed substrate 10 and the movable electrode 23 is attracted to the fixed substrate 10. As a result, the second movable piece 27 is curved, a large contact pressure is obtained, and the signal is stably propagated between the signal wirings 14a and 17a.

In the above embodiment, the case where the concave portion 12 is formed only in the fixed substrate 10 has been described. However, the present invention is not limited to this, and as shown in FIG.
A concave portion 27a is formed on the lower surface of the
8 may be formed (second embodiment). According to the present embodiment, the height dimensions of the fixed contacts 14b, 17b and the movable contact 28 are substantially reduced. For this reason, the fixed substrate 10
The movable electrode 23 can be arranged close to the first electrode, and the distance between the opposing surfaces can be reduced. As a result, there is an advantage that a larger electrostatic attraction is obtained and the driving voltage is reduced.

In the third embodiment, as shown in FIGS. 9 and 10, a large number of opposed ridges 17c, 17c are provided on the surfaces of the fixed contacts 14b, 17b. The other parts are the same as those of the first embodiment, and the description is omitted. According to this embodiment, there is an advantage that the movable contact 28 does not easily come into contact with the fixed contacts 14b and 17b, and the contact reliability is improved.

In the fourth embodiment, as shown in FIG. 11, a shield layer 32 made of a conductive material is formed on the ceiling surface of a recess 31 of a cap 30, while the cap 30 is formed so as to correspond to the shield layer 32. Is a case where the shield layer 33 is formed on the upper surface of the substrate. Then, the shield layers 32, 33
Are provided. According to the present embodiment, magnetic shielding can be performed via the shield layers 32 and 33. For this reason, there is an advantage that the influence of leakage or disturbance of a high-frequency signal can be prevented, and high-frequency characteristics are improved.

In the fifth embodiment, as shown in FIG. 12, a shield layer 32 made of a conductive material is formed on a ceiling surface of a recess 31 of a cap 30 and the recess 3 is formed from the shield layer 32.
This is a case where the connecting portion 36 extends to the edge of the opening of the first opening. In addition, the movable substrate 20 is grounded through a wire bonding pad 20a provided on the upper surface edge. According to the present embodiment, there is an advantage that a micro relay having high high-frequency characteristics can be obtained as in the fourth embodiment.

In the above-described embodiment, the case where the first and second movable pieces are supported at both ends has been described. However, a cantilever structure or a multi-point support structure such as a substantially swastika shape on a plane may be used.

[0025]

As is apparent from the above description, according to the micro relay of the first aspect of the present invention, first, the first movable piece is driven, and the movable contact contacts the fixed contact. Further, after the contact, the movable substrate is attracted against the resultant force of the spring force of the first movable piece and the spring force of the second movable piece, and the first movable piece is attracted to the fixed substrate. Therefore, by adjusting the spring force of the first movable piece, the movable substrate can be driven with a low drive voltage at the beginning of operation, and the contact can be contacted with a high contact pressure at the time of operation. A relay is obtained.

According to the second aspect, the movable substrate is displaced in the plate thickness direction since the movable substrate has a substantially swastika shape in a plane. For this reason, the contact of the contact is eliminated, and the contact reliability is improved. According to the third and fourth aspects, a movable substrate provided with the second movable piece integrated with the first movable piece can be obtained. And the first and second
By adjusting the spring force of the movable piece, a micro relay having desired operating characteristics can be easily obtained. According to the fifth aspect, since the contact is provided on the bottom surface of the concave portion provided on the opposing surface, the height of the contact is substantially reduced, and the fixed substrate and the movable substrate can be brought closer to each other. For this reason, the distance between the opposing surfaces is shortened, and the driving voltage can be further reduced.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a micro relay according to the present invention.

FIG. 2 is a bottom view of the movable substrate shown in FIG.

FIG. 3 is a plan view of the fixed substrate shown in FIG.

FIG. 4 is a process chart of the fixed substrate shown in FIG. 1;

FIG. 5 is a process chart of the movable substrate shown in FIG. 1;

FIG. 6 is a process step diagram showing a manufacturing method after a movable substrate is joined and integrated with a fixed substrate.

FIG. 7 is a process step diagram showing a manufacturing method after a movable substrate is joined and integrated with a fixed substrate.

FIG. 8 is a sectional view showing a second embodiment of the micro relay according to the present invention.

FIG. 9 is an exploded perspective view showing a third embodiment of the micro relay according to the present invention.

10 is a partially enlarged view of the fixed contact shown in FIG.

FIG. 11 is an exploded perspective view showing a fourth embodiment of a micro relay according to the present invention.

FIG. 12 is an exploded perspective view showing a micro relay according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Fixed substrate (fixed electrode) 11 ... Recess 12 ... Recess 13 ... Insulating oxide film 14, 15, 16, 17 ... Pad for wire bonding 14a, 17a ... Signal wiring 14b, 17b ... Fixed contact 18a, 18b, 18c ... Connection pod 19 ... concave portion 20 ... movable substrate 22 ... slit 23 ... movable electrode (first movable piece) 26 ... slit 27 ... second movable piece 28 ... movable contact 30 ... cap member 31 ... recess 32, 33 ... shield layer 34, 35 ... Through-hole

Continuing on the front page (72) Inventor Tomonori Sumi, O-Muron Co., Ltd., 10-10 Hanazono Todo-cho, Ukyo-ku, Kyoto-shi, Kyoto (72) Inventor Minoru Sakata 10-Ohmron Todo-cho, Hanazono-ku, Ukyo-ku, Kyoto, Kyoto

Claims (5)

[Claims] 1. A movable substrate is disposed opposite to a fixed substrate, the movable substrate is driven by an electrostatic attraction generated by applying a voltage between the two substrates, and a movable contact formed on a lower surface of the movable substrate is connected to the movable substrate. By contacting / separating a pair of fixed contacts arranged side by side on the upper surface of the fixed substrate, the signal wiring extending from each fixed contact is electrically connected and disconnected.
In the microrelay to be interrupted, the movable substrate is provided with a first movable piece cut out by providing a slit, and a second movable piece is formed in the first movable piece and is less elastically deformable than the first movable piece. Wherein the movable contact is provided on a lower surface of the second movable piece. 2. The microrelay according to claim 1, wherein the first movable piece is formed in a substantially swastika shape on a plane. 3. The apparatus according to claim 1, wherein a pair of slits are arranged in the first movable piece and a second movable piece is cut out.
Or the microrelay according to 2. 4. The apparatus according to claim 1, wherein said first movable piece is partially thinned to form a second movable piece.
The microrelay according to any one of the above. 5. The method according to claim 1, wherein a concave portion is formed on at least one of the opposing fixed substrate and the movable substrate, and a contact is disposed on a bottom surface of the concave portion. The microrelay according to any one of the preceding claims.