KR20080093766A - Micro electro mechanical systems actuator and various applicable device using thereof - Google Patents

Abstract

A MEMS(Micro Electro Mechanical Systems) actuator and an application device using the same are provided to reduce resistance compositions due to the arrangement of electric wiring by driving third conductive layers using electric field distribution. A MEMS actuator comprises insulation substrates(210), first conductive layers(220) formed on the insulation substrates, second conductive layers(230) separated from the first conductive layers, third conductive layers(240), and power units(260). The third conductive layers are separated from the first and second conductive layers. The power units apply a voltage to the first and second conductive layers. The first and second conductive layers have different areas.

Description

MICRO ELECTRO MECHANICAL SYSTEMS ACTUATOR AND VARIOUS APPLICABLE DEVICE USING THEREOF

1 is a perspective view showing a conventional actuator.

2 is a cross-sectional view of a conventional actuator taken along the line A-A '.

3 is a cross-sectional view showing a variable capacitor using a conventional actuator.

4 and 5 illustrate an actuator according to an embodiment of the present invention.

6 and 7 are diagrams showing electric field distribution of an actuator according to an embodiment of the present invention.

8 to 10 are diagrams illustrating a capacitor using an actuator according to an embodiment of the present invention.

11 and 12 illustrate a switch according to an embodiment of the present invention.

13 and 14 illustrate electric field distributions of a switch according to an exemplary embodiment of the present invention.

       ***** Explanation of symbols for main parts of drawing *****

110, 210, 310: insulated substrate

120, 220, 320: first conductive layer

130, 230, 330: second conductive layer

240 and 340: third conductive layer

140, 250, 350: support part

150, 260, 300: power supply

160: capacitor

270: first capacitor

280: second capacitor

290: Synthetic Capacitor

360: first signal transmission line

370: second signal transmission line

380 dimple

390: insulation layer

The present invention relates to a micro electromechanical system (MEMS) actuator.

Microelectromechanical systems (MEMS) are typically used in critical parts such as sensors or printer heads of information equipment. In addition, microelectromechanical systems are based on the structure technology of semiconductor integrated circuits and employ microfabrication technology on silicon wafers. One example of a microelectromechanical system using such a microfabrication technique is an actuator.

Hereinafter, with reference to the accompanying drawings will be described a conventional actuator.

1 and 2 are perspective views showing the structure of a conventional actuator.

Referring to FIG. 1, a conventional microelectromechanical system actuator includes an insulating substrate 110 and a first conductive layer 120 on the insulating substrate 110. Subsequently, there is a second conductive layer 130 facing and spaced apart from the insulating substrate 110. Subsequently, there is a support 140 that supports the second conductive layer 130 from the insulating substrate 110. Here, the support 140 is an electrically conductive material. In addition, the supporter 140 may be configured of a pillar and a pillar connected to the insulating substrate 110 and a connection portion connecting the second conductive layer 130. Subsequently, there is a power supply unit 150 that applies a voltage to the first conductive layer 120 and the supporter 140.

FIG. 2 is a cross-sectional view taken along line AA ′ of the actuator of FIG. 1. FIG.

Referring to FIG. 2, the driving method of the conventional actuator is first applied to the first conductive layer 120 and the supporter 140 formed on the insulating substrate 110, respectively. In this case, the voltage applied to the support 140 is transferred to the second conductive layer 130. Thereafter, an electric field distribution is formed between the first conductive layer 120 and the second conductive layer 130 by the applied voltage. The charge in the electric field distribution is stored between the first conductive layer 120 and the second conductive layer 130. This is described later with reference to FIG. Subsequently, electrostatic attraction acts between the first conductive layer 120 and the second conductive layer 130 by the charge in the electric field distribution. By the electrostatic attraction, the second conductive layer 130 moves in the direction of the first conductive layer 120. At this time, the restoring force acts by the support part 140 supporting the second conductive layer 130 from the insulating substrate 110. Here, the restoring force by the support 140 acts in the opposite direction to the electrostatic force. Accordingly, the second conductive layer 130 moves to a point where the electrostatic force and the restoring force are in equilibrium with each other. Therefore, the conventional actuator is electrostatically driven as the electrostatic force and the restoring force act on the second conductive layer 130 by the applied voltage.

Next, an actuator for storing electric charges induced by electric field distribution will be described.

As described above, charge is stored between the first conductive layer 120 and the second conductive layer 130 of the actuator. This is represented by a capacitor 160 having the first conductive layer 120 and the second conductive layer 130 as an electrode plate, as shown in FIG. Here, the second conductive layer 130 constituting the electrode of the capacitor 160 is moved toward the first conductive layer 120 by the electrostatic driving of the actuator. As the second conductive layer 130 moves, the distance between the first conductive layer 120 and the second conductive layer 130 is adjusted. This is to control the interval of the capacitor consisting of the first conductive layer 120 and the second conductive layer 130. Therefore, the capacitance varies between the first conductive layer 120 and the second conductive layer 130 of the actuator.

In order to drive such a conventional actuator, a voltage is applied to the first conductive layer 120 and the supporter 140 formed on the insulating substrate 110. In this case, in order for the actuator to be driven at a low voltage, the restoring force of the connection part connected to the second conductive layer 130 should be weak. In addition, in order for the restoring force of the connection to be weakly designed, the thickness and width of the support 140 must be thin. In this case, the support 140 inevitably has a large resistance value. In addition, an electrical wiring is additionally installed in the second conductive layer 130 for electrostatic driving of the actuator. In this case, the equivalent driving resistance of the actuator is increased by the additional electrical wiring of the second conductive layer 130. Therefore, as the resistance component is increased, there is a problem that the performance of the actuator is lowered as a whole.

An object of the present invention to solve this problem is to provide an actuator of a microelectromechanical system with a reduced resistance component.

       In addition, to provide an application device using an actuator with a reduced resistance component.

An actuator according to the present invention for solving the technical problem is an insulating substrate, a first conductive layer formed on the insulating substrate, a second conductive layer formed to be spaced apart from the first conductive layer, the first conductive layer and And a third conductive layer facing the second conductive layer and spaced apart from each other, and a power supply unit applying a voltage to the first conductive layer and the second conductive layer.

       Preferably, the first conductive layer and the second conductive layer are formed in different areas.

       Preferably, an insulating film is formed on the first conductive layer and the second conductive layer.

       The third conductive layer preferably includes one of polycrystalline silicon or a metal doped with a dopant.

       It is preferable to further include a support portion formed between the third conductive layer and the insulating substrate to support the third conductive layer.

       The electric field distribution is preferably formed between the first conductive layer, the second conductive layer, and the third conductive layer by the applied voltage.

       It is preferable that the said 3rd conductive layer moves to the said 1st conductive layer and the 2nd conductive layer direction by the said electric field distribution.

       Capacitors are formed between the first conductive layer and the third conductive layer and between the second conductive layer and the third conductive layer by the electric field distribution, and the capacitance is changed according to the movement of the third conductive layer. It is preferable.

The switch according to the present invention is opposed to and spaced apart from an insulating substrate, a first conductive layer formed on the insulating substrate, a second conductive layer spaced apart from the first conductive layer, the first conductive layer and the second conductive layer. A third conductive layer formed, a power supply unit applying a voltage to the first conductive layer and the second conductive layer, a dimple disposed below the third conductive layer, a first signal transmission line and the first signal transmission line formed on the insulating substrate And a second signal transmission line spaced apart from the second signal transmission line.

       Preferably, an insulating film is formed on the first conductive layer and the second conductive layer.

       The third conductive layer preferably includes one of polycrystalline silicon or a metal doped with a dopant.

       It is preferable to further include a support portion formed between the third conductive layer and the insulating substrate to support the third conductive layer.

       The electric field distribution is preferably formed between the first conductive layer, the second conductive layer, and the third conductive layer by the applied voltage.

       It is preferable that the said 3rd conductive layer moves to the said 1st conductive layer and the said 2nd conductive layer direction by the said electric field distribution.

       Preferably, the dimple is electrically connected to the first signal transmission line and the second signal transmission line by the movement of the third conductive layer to transmit a signal.

       Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention;

       [Actuator]

       4 to 8 are diagrams showing the structure and electric field distribution of the actuator according to the present invention.

       4 and 5 are diagrams showing the structure of an actuator according to an embodiment of the present invention.

       4 and 5, an actuator according to an embodiment of the present invention may include an insulating substrate 210, a first conductive layer 220 formed on the insulating substrate, and a second conductive layer spaced apart from the first conductive layer. Voltages on the third conductive layer 240 and the first conductive layer 220 and the second conductive layer 230 which are formed to face the first conductive layer 220 and the second conductive layer 230 and are spaced apart from each other. It includes a power supply unit 260 for applying.

4 and 5, the structure of the actuator will be described in detail.

First, there is an insulating substrate 210 of the actuator. The insulating substrate 210 may be formed of one of a glass substrate, a ceramic substrate, a silicon substrate, and a polymer substrate to have insulation and surface precision. The polymer substrate may include a plastic substrate. Subsequently, a first conductive layer 220 and a second conductive layer 230 are formed on the insulating substrate 210. Here, the first conductive layer 220 and the second conductive layer 230 are spaced apart from each other. In addition, the first conductive layer 220 and the second conductive layer 230 may have different areas. In addition, an insulating film is formed on the first conductive layer 220 and the second conductive layer 230 to prevent discharge due to the contact of the third conductive layer 240. Subsequently, a power supply unit 260 for applying a voltage to the first conductive layer 220 and the second conductive layer 230 is connected. Subsequently, there is a third conductive layer 240 facing and spaced apart from the first conductive layer 220 and the second conductive layer 230. The third conductive layer 240 is in an electrically floating state with the insulating substrate 210, the first conductive layer 220, and the second conductive layer 230. In addition, the third conductive layer 240 may be formed of one of polycrystalline silicon or metal doped with a dopant. As such, the third conductive layer 240 is formed of one of polycrystalline silicon or metal doped with a dopant, so that the third conductive layer 240 can be driven by a subsequent electric field distribution. Subsequently, there is a support part 250 connecting the third conductive layer 240 and the insulating substrate 210. In this case, the support part 250 supports the third conductive layer 240 from the insulating substrate 210 to be in a floating state. The support part 250 includes a first horizontal part horizontally connected to the third conductive layer 240, a pillar formed to have a predetermined height from the insulating substrate 210, and a second horizontal part connecting the first horizontal part and the pillar. can do.

        Next, the driving method of the actuator according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

        First, different voltages are applied to the first conductive layer 220 and the second conductive layer 230, respectively. As a result, as shown in FIG. 6, a strong electric field distribution is formed in the vicinity of the first conductive layer 220 and the second conductive layer 230 adjacent to each other. The electric field distribution thus formed is formed as shown in FIG. 7 by the third conductive layer 240 which is electrically floating. The electric field distribution is divided into regions 1 and 2 based on the third conductive layer 240 as shown in FIG. 7. The charge in the electric field distribution of the region 1 is stored between the first conductive layer 220 and the third conductive layer 240 and between the second conductive layer 230 and the third conductive layer 240, respectively. This will be described later with reference to FIG. Subsequently, the electric field distributions formed in the regions 1 and 2 are unbalanced by the third conductive layer 240 which is electrically floating. Due to the unbalanced electric field distribution between the regions 1 and 2, the third conductive layer 240 moves in the direction of the first conductive layer 220 and the second conductive layer 230. Therefore, the actuator is electrostatically driven by the third conductive layer 240 being moved by the unbalance of the electric field distribution.

       Next, an actuator for storing charges induced by the electric field distribution will be described in detail with reference to the accompanying drawings.

       As described above, charges in the electric field distribution of the region 1 are stored between the first conductive layer 220 and the third conductive layer 240, and the second conductive layer 230 and the third conductive layer 240, respectively. For convenience of explanation, as shown in FIG. 8, the first conductive layer 220 and the third conductive layer 240 are the first capacitor 270, and the second conductive layer 230 and the third conductive layer are illustrated in FIG. 8. Layer 240 will be referred to as a second capacitor 280. Here, since the first capacitor 270 and the second capacitor 280 use the third conductive layer 240 as a common electrode plate, they are connected in series. In addition, the third conductive layer 240, which is a common electrode plate of the first capacitor 270 and the second capacitor 280, may be formed by the first conductive layer 220 and the second conductive layer. Move in the direction (230). As the third conductive layer 240 moves as described above, the intervals of the respective conductive layers are adjusted. This is to control the capacitance of the capacitor consisting of each conductive layer. Therefore, the capacitance of the first capacitor 270 and the second capacitor 280 of the actuator is variable. In addition, the first conductive layer 220 and the second conductive layer 230 having different areas may be installed in the actuator in order to vary the capacitance of the first capacitor 270 and the second capacitor 280.

Next, FIG. 9 illustrates a first capacitor 270 including the first conductive layer 220 and the third conductive layer 240, and a second layer including the second conductive layer 230 and the third conductive layer 240. An equivalent circuit of the capacitor 280 is shown. In addition, the composite capacitor 290 illustrated in FIG. 9 is represented as shown in FIG. 10. Here, the equivalent synthetic capacitance of the synthetic capacitor is obtained by the following.

, c ₁ is the capacitance of the first capacitor 270, c ₂ is the capacitance of the second capacitor 280, C is the equivalent composite capacitance of the first capacitor and the second capacitor.

       [switch]

11 and 12 illustrate a switch according to an embodiment of the present invention.

11 and 12, the switch according to the present invention includes an insulating substrate 310, a first conductive layer 320 formed on the insulating substrate, and a second conductive layer formed to be spaced apart from the first conductive layer 320. 330, the third conductive layer 340, the first conductive layer 320, and the second conductive layer 330 which are formed to face the first conductive layer 320 and the second conductive layer 330, and are spaced apart from each other. Spaced apart from the power supply unit 300 to be applied, a dimple 380 disposed under the third conductive layer 340, the first signal transmission line 360 and the first signal transmission line 360 provided on the insulating substrate 310. And a second signal transmission line 370 provided.

       Hereinafter, a structure of a switch according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

       11 and 12, there is an insulating substrate 310 of a switch. The insulating substrate 310 may be formed of one of a glass substrate, a ceramic substrate, a silicon substrate, and a polymer substrate to have insulation and surface precision. Here, the polymer substrate may be a plastic substrate. Subsequently, there is a first conductive layer 320 and a second conductive layer 330 formed of an electrically conductive material on the insulating substrate 310. Here, the first conductive layer 320 and the second conductive layer 330 are spaced apart from each other. Subsequently, there is a power supply unit 300 that applies a voltage to the first conductive layer 320 and the second conductive layer 330. Subsequently, the first signal transmission line 360 and the second transmission line 370 are spaced apart between the first conductive layer 320 and the second conductive layer 330. The first signal transmission line 360 and the second transmission line 370 are also spaced apart from the first conductive layer 320 and the second conductive layer 330. Subsequently, there is a third conductive layer 340 facing and spaced apart from the first conductive layer 320 and the second conductive layer 330. The third conductive layer 340 may be formed of an insulating substrate 310, a first conductive layer 320 and a second conductive layer 330, and a first signal transmission line 360 and a second signal transmission line 370. It is electrically floating. In addition, the third conductive layer 340 may be formed of one of polycrystalline silicon or metal doped with a dopant. As such, the third conductive layer 340 is formed of one of polycrystalline silicon or metal doped with a dopant, so that the third conductive layer 340 can be driven by a subsequent electric field distribution. Subsequently, there is a support part 350 connecting the third conductive layer 340 to the insulating substrate 310. In this case, the support part 350 supports the third conductive layer 340 from the insulating substrate 310 to be in a floating state. The support part 350 includes a first horizontal part horizontally connected to the third conductive layer 340, a pillar formed to have a predetermined height from the insulating substrate 310, and a second horizontal part connecting the first horizontal part and the pillar. can do. Subsequently, there is a dimple 380 that transmits signals of the first signal transmission line 360 and the second transmission line 370 under the third conductive layer 340. In addition, the insulating layer 390 is preferably provided between the dimple 380 and the third conductive layer 340. The insulating layer 390 electrically insulates the third conductive layer 340 from the first signal transmission line 360 and the second signal transmission line 370.

Next, a driving method of a switch according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

      As described above, different voltages are applied to the first conductive layer 320 and the second conductive layer 330, respectively. Thereafter, as shown in FIG. 13 to which a voltage is applied, a strong electric field is formed in the vicinity of the first conductive layer 320 and the second conductive layer 330 adjacent to each other. The electric field distribution thus formed is formed as shown in FIG. 14 by the third conductive layer 340 electrically floating. The electric field distribution is divided into regions 1 and 2 based on the third conductive layer 340 as shown in FIG. The electric field distributions formed in the region 1 and the region 2 are unbalanced by the third conductive layer 340 electrically floating. As the electric field distributions of the regions 1 and 2 are unbalanced, the third conductive layer 340 is oriented in the direction of the first conductive layer 320 and the second conductive layer 330 as indicated by the arrows in FIG. Will move to. Accordingly, the dimple 380 disposed under the third conductive layer 340 also moves in the direction of the first conductive layer 320 and the second conductive layer 330. The dimple 380 moved in the direction of the first conductive layer 320 and the second conductive layer 330 is in contact with the first signal transmission line 360 and the second signal transmission line 370 formed on the insulating substrate 310. . Therefore, the dimple 380 serves to electrically connect the first signal transmission line 360 and the second signal transmission line 370 spaced apart from each other. In addition, when the dimple 380 contacts the first signal transmission line 360 and the second signal transmission line 370 to transmit a signal, the potential formed in the third conductive layer 340 may have a first potential. It serves as an electrical insulation so as not to affect the signal transmitted between the signal transmission line 360 and the second signal transmission line 370.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the above-described technical configuration of the present invention may be embodied in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced.

Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

       As described above in detail, in the actuator and the switch according to the present invention, the third conductive layer electrically floating by using the electric field distribution is driven, so that electrical wiring for driving is not additionally installed. This reduces the resistance of the actuators and switches due to the placement of additional electrical wiring.

       In addition, since the resistance component is reduced, there is an effect that the Q-Factor of the variable capacitor is increased.

Claims (16)

Insulating substrate; A first conductive layer formed on the insulating substrate; A second conductive layer spaced apart from the first conductive layer; A third conductive layer facing and spaced apart from the first conductive layer and the second conductive layer; And        A power supply unit applying a voltage to the first conductive layer and the second conductive layer; Including, the actuator.        The method of claim 1,        And the first conductive layer and the second conductive layer are formed in different areas. The method according to claim 1 or 2, An actuator having an insulating film formed on the first conductive layer and the second conductive layer.        The method of claim 1,        And the third conductive layer comprises one of polycrystalline silicon or metal doped with dopant.        The method of claim 1,        And a support formed between the third conductive layer and the insulating substrate to support the third conductive layer.        The method of claim 1,        And an electric field distribution is formed between the first conductive layer, the second conductive layer, and the third conductive layer by the applied voltage.        The method of claim 6,        And the third conductive layer moves in the direction of the first conductive layer and the second conductive layer by the electric field distribution.        The method of claim 6,        Capacitors are formed between the first conductive layer and the third conductive layer and between the second conductive layer and the third conductive layer by the electric field distribution, and the capacitance is changed according to the movement of the third conductive layer. , Actuator. Insulating substrate; A first conductive layer formed on the insulating substrate; A second conductive layer spaced apart from the first conductive layer; A third conductive layer facing and spaced apart from the first conductive layer and the second conductive layer;       A power supply unit applying a voltage to the first conductive layer and the second conductive layer;       Dimples disposed under the third conductive layer;       A first signal transmission line provided on the insulating substrate;       A second signal transmission line spaced apart from the first signal transmission line;       Switch comprising a.       The method of claim 9,       The switch further comprises an insulating layer provided between the third conductive layer and the dimple. The method of claim 9, And an insulating film is formed on the first conductive layer and the second conductive layer.        The method of claim 9,        And the third conductive layer comprises one of doped polycrystalline silicon or metal doped.        The method of claim 9,        And a support formed between the third conductive layer and the insulating substrate to support the third conductive layer.        The method of claim 9,        And a field distribution is formed between the first conductive layer, the second conductive layer, and the third conductive layer by the applied voltage.        The method of claim 14,        And the third conductive layer moves in the direction of the first conductive layer and the second conductive layer by the electric field distribution.        The method according to claim 9 or 15,        And the dimple is electrically connected to the first signal transmission line and the second signal transmission line by the movement of the third conductive layer to transmit a signal.

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