JP2020089946A - Microstructure and method for controlling microstructure - Google Patents

Abstract

To provide a microstructure which has a simple structure and small energy necessary for restoring operation.SOLUTION: A microstructure has a substrate, a support body, a beam, long piece driving means, and short piece driving means. The substrate is a solid that has rigidity and has spreading on the plane. The support body forms a support shaft parallel to the surface of the substrate, and supports the beam. The beam is formed with a long piece which is supported by the support shaft at a position shifted from the center in its drawing direction and has a length longer from the support shaft to the end, and a short piece which has a length shorter from the support shaft to the end. The beam is configured to be rotated the support shaft as a shaft. The long piece driving means drives the long piece, and the short piece driving means drives the short piece. The driving force of the short piece driving means is force inversely proportional to the square of the distance or a force inversely proportional to a function with an increase quicker the square or higher of the distance.SELECTED DRAWING: Figure 1

Description

The present invention relates to microstructures and methods of controlling microstructures.

As a microstructure used in MEMS (Micro Electro Mechanical Systems) and the like, a structure in which a cantilever or double-supported beam structure is installed on a substrate is known. In this structure, for example, the beam and the substrate can be moved closer to each other or separated from each other. By using this operation, it is possible to configure a switch that is turned on when the beam and the substrate come close to each other, and can be turned off when they are separated from each other, or it is possible to drive a micro pump, for example.

An electrostatic force, a magnetic force, a piezoelectric deformation force, or the like is used as an operation source for driving the beam. When an electrostatic force is used as the actuation source, an apparatus similar to that used in the semiconductor process can be applied, so that the manufacturing is easy and the manufacturing cost is expected to be reduced.

In such a beam structure, it is often the case that a part of the beam is fixed and the beam is bent. In many cases, the force of the actuation source is used for this operation, and the elastic force (spring force) of the beam is used for returning. However, in the return by the spring force, there is a problem in the certainty of the return because the spring force itself is not larger than the electromagnetic force and the spring force is deteriorated due to the deterioration of the beam.

For this reason, a method of ensuring the return of the switch is being studied. For example, Patent Document 1 discloses a technique for ensuring the return of a beam supported above a substrate surface with a predetermined gap. In this technique, a first fixed electrode that pulls the beam toward the substrate to establish a conductive state is provided on the substrate, and a second fixed electrode that is fixed above the beam with a predetermined gap is provided. The second fixed electrode is used to pull the beam away from the substrate to enhance the certainty of returning to the non-conductive state.

In addition, Patent Document 2 discloses a microswitch that configures a seesaw structure with the center of the beam as a fulcrum and drives both ends of the beam by electrostatic force from the substrate side. With this switch, since the same driving force as that for turning on is used for returning from turning on, that is, the operation of turning off the switch, it is possible to increase the certainty of returning.

Patent No. 5478060 JP, 2001-076605, A

However, the technique of Patent Document 1 has a problem that the structure becomes complicated because the second fixed electrode fixed in the air is provided above the beam. Further, the technique of Patent Document 2 has a problem that the same voltage is required for the main operation and the sub-operation for restoration. As is clear from the fact that the structure using the spring force of the beam is preferred, there is a demand to reduce the energy used for the returning operation. The technology of Patent Document 2 has not been able to meet this demand.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a microstructure having a simple structure and a small energy required for a returning operation.

In order to solve the above-mentioned subject, a microstructure has a base, a support, a beam, a long piece drive means, and a short piece drive means. The substrate is a solid that has rigidity and spreads over the surface. The support forms a support axis parallel to the surface of the substrate and supports the beam. The beam is supported by the support shaft at a position deviated from the center in the extending direction, and a long piece having a long length from the support shaft to the end and a short piece having a short length from the support shaft to the end are formed. .. The beam can rotate about a support shaft. The long piece driving means drives the long piece, and the short piece driving means drives the short piece. The driving force of the short piece driving means is a force that is inversely proportional to the square of the distance or a force that is inversely proportional to a function that increases faster than the square of the distance.

An advantage of the present invention is that it is possible to provide a microstructure having a simple structure and a small energy required for the returning operation.

It is a side view and a top view showing a microstructure of a 1st embodiment. It is sectional drawing and the top view which show the microstructure of 2nd Embodiment. It is sectional drawing and the top view which show operation|movement of the microstructure of 2nd Embodiment. 9A and 9B are a cross-sectional view and a plan view showing the method for manufacturing the microstructure of the second embodiment. It is sectional drawing and the top view which show the microstructure of 3rd Embodiment. It is sectional drawing and a top view which show a part of manufacturing method of the microstructure of 3rd Embodiment. It is sectional drawing and the top view which show another one part of the manufacturing method of the microstructure of 3rd Embodiment. It is the side view and top view which show the microstructure of 4th Embodiment. It is sectional drawing which shows the microstructure of 5th Embodiment. It is sectional drawing which shows another example of the microphone structure of 5th Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments described below have technically preferable limitations for implementing the present invention, but the scope of the invention is not limited to the following. It should be noted that similar components in each drawing are denoted by the same reference numerals, and description thereof may be omitted.

(First embodiment)
FIG. 1 is a side view and a plan view showing the microstructure of the present embodiment. The microstructure has a base 1, a support 2, a beam 3, a long piece drive means 4 and a short piece drive means 5.

The base body 1 is a solid having rigidity and having a spread on the surface. In the example of FIG. 1, the shape is flat, but the shape of the substrate 1 is not limited to this, and may be, for example, a shape having a curved surface.

The support body 2 forms a support shaft 2 a parallel to the surface of the base body 1 and supports the beam 3.

The beam 3 is a solid having a shape extending in a direction along the surface of the base 1. The beam 3 is supported by the support shaft 2a at a position displaced from the center in the extending direction. As a result, a long piece 3a having a long length from the support shaft 2a to the end and a short piece 3b having a short length from the support shaft 2a to the end are formed. The beam 3 can rotate about the support shaft 2a.

The long piece driving means 4 drives the long piece 3a. The driving force can be, for example, a suction force, but may be a repulsive force. The short piece driving means 5 drives the short piece. The driving force of the short piece driving means 5 can be a suction force or a repulsive force like the long piece driving means 4. Here, at least the driving force generated by the short piece driving means 5 is a force that is inversely proportional to the square of the distance or a force that is inversely proportional to a function that increases faster than the square of the distance.

In the above configuration, the displacement amount of the end portion of the long piece 3a in the rotating operation of the beam 3 is always smaller than the displacement amount of the end portion of the short piece 3b. When the distance between the end of the short story 3b and the support shaft 2a becomes shorter, the moment of rotation decreases in proportion to the first power of the distance. On the other hand, the gap between the end of the short piece 3b and the short piece drive means 5 becomes smaller in proportion to the first power of the distance. As described above, the driving force generated by the short-piece driving means 5 is a force that is inversely proportional to the square of the distance or a force that is inversely proportional to a function that increases faster than the square of the distance. As a result, the shorter the length of the short piece 3b, the greater the force exerted by the short piece drive means 5 on the end of the short piece 3b. That is, when the driving of the long piece 3a is the main operation and the driving of the short piece 3b is the returning operation, the energy required for the returning operation can be reduced.

As described above, according to this embodiment, it is possible to provide a microstructure having a simple structure and a small energy required for the returning operation.

(Second embodiment)
2A and 2B are a cross-sectional view and a plan view showing the microstructure of the second embodiment. FIG. 2A shows a cross section taken along line XX′ of FIG. The microstructure has a substrate 10, a supporting portion 20, and a beam 30 supported by the supporting portion 20.

On the substrate 1, a supporting portion 20, a long piece driving means 41, a short piece driving means 42, and a board side signal line 43 are provided. The long piece driving means 41, the short piece driving means 42, and the board-side signal line 43 may be formed inside the board 1.

The supporting part 20 forms a supporting shaft 21 parallel to the surface of the substrate, for example, in a double-supported shape. Here, the both-sided support is a structure in which two base portions support two portions of the shaft. The example of FIG. 2 shows an example in which the beam 30 and the supporting portion 20 are integrated, but a structure such as a hinge structure which is not integrated may be used.

The beam 30 is supported by the support shaft 21 at a position deviated from the center in the extending direction, and can rotate about the support shaft 21. By supporting the beam asymmetrically in this manner, the beam 30 is provided with a long piece 31 having a long length from the support shaft 21 to the end and a short piece 32 having a short length from the support shaft 21 to the end.

Further, in the example of FIG. 2, the long piece driving element 51 is provided near the end of the long piece 31, and the short piece driving element 52 is provided near the end of the short piece 32. The long piece driving element 51 receives the driving force of the long piece driving means 41, and the short piece driving element 52 receives the driving force of the short piece driving means 42. The positions of the long piece driving element 51 and the short piece driving element 52 are not particularly limited, but the long piece driving element 51 is arranged so that the distance from the support shaft 21 is longer.

In the example of FIG. 2, the beam-side signal line 53 is provided at a position corresponding to the board-side signal line 43 of the long piece 31. Then, when the long piece driving element 51 is attracted to the long piece driving means 41 and the beam side signal line 53 approaches the board side signal line 43, signals are transmitted and received between the two. That is, the microstructure of FIG. 2 forms a microswitch that turns on when the long piece 31 approaches the substrate 10, turns off when the short piece 32 approaches the substrate 10, and turns off when the long piece 31 moves away from the substrate 10. A signal is externally supplied to the board-side signal line 43 via the terminal 11. Further, a driving signal for generating a driving force is input to each of the long piece driving means 41 and the short piece driving means 42 via the terminal 11. In the example of FIG. 2, the beam-side signal line 53 is provided on the surface of the long piece 31 far from the substrate 10, but it may be provided on the surface of the long piece 31 on the substrate 10 side. It may be provided in. Alternatively, the long piece 31 itself may serve as a signal line. Further, in FIG. 2, the beam-side signal line 53 is arranged on the support shaft 21 side of the long piece drive element 51, but it may be reversed. However, the relationship (distance from the support shaft 21 to the long piece driving element 51)>(distance from the support shaft 21 to the short piece driving element 52) is always satisfied.

The long piece drive means 41 generates an attractive force or a repulsive force with respect to the long piece drive element 51. In addition, the short piece driving means 42 generates an attractive force or a repulsive force with respect to the short piece driving element 52. Here, an explanation will be given using an example in which the force generated by the long piece driving means 41 and the short piece driving means 42 is a suction force for sucking the long piece driving element 51 and the short piece driving element 52 which form a pair. The long piece driving means 41 and the short piece driving means 42 cooperate with each other and operate so as not to interfere with each other's operations. For example, when the long piece driving means 41 is generating the suction force, the short piece driving means 42 does not generate the suction force, and when the short piece driving means 42 is generating the suction force, the short piece driving means 42 is It works so as not to generate force. The force generated by the long piece driving means 41 can be, for example, an electrostatic force, a magnetic force, an attraction force, or the like. Further, the force generated by the short piece driving means 42 is a force having the principle of being inversely proportional to a function that increases faster than the square of the distance. This force can be, for example, an electrostatic force, a magnetic force, an attraction force, or the like.

FIG. 3 is a cross-sectional view showing the operation of the microstructure of the second embodiment. FIG. 3A shows a state in which the long piece drive means 41 attracts the long piece drive element 51 and the micro switch is turned on. As shown in FIGS. 2 and 3, when the beam 30 and the support portion 20 are integrated, the connection portion between the support portion 20 and the beam 30 serves as the support shaft 21, and the support shaft 21 is twisted, so that the beam 30 is Performs a seesaw-like turning operation.

As shown in FIG. 3A, the displacement d2 of the short piece drive element 52 from the flat state to the on state is smaller than the displacement d1 of the long piece drive element 51. Further, FIG. 3B shows a state in which the short piece driving means 42 attracts the short piece driving element 52 and the micro switch is turned off. Here, the displacement d2′ of the short piece driving element 52 from the flat state to the off state is smaller than the displacement d1′ of the long piece driving element 51. As is clear from these examples, the displacement of the short piece drive element 52 when the beam 30 rotates is always smaller than the displacement of the long piece drive element 51. As described above, the lever principle is inversely proportional to the first power of the distance, and the suction force of the short piece driving means 42 is inversely proportional to a function that increases faster than the second power of the distance. Therefore, the energy applied to the short piece drive means 42 for attracting the short piece drive element 52 is smaller than the energy applied to the long piece drive means 41 for attracting the long piece drive element 51. For example, when the attractive force is generated by an electrostatic force, the voltage applied to the short piece driving means 42 can be reduced. When electrostatic force is used, the short piece driving means 42 and the long piece driving means 41 can be electrodes, for example.

Next, a method for manufacturing the microstructure of this embodiment will be described. FIG. 4 is a sectional view and a plan view showing this manufacturing method. First, each of the long piece driving means 41, the substrate side signal line 43, and the short piece driving means 42 is formed on the substrate 10 by using an arbitrary method such as vapor deposition via a metal mask or plating accompanied by photolithography. Form elements [FIG. 4(a)].

Next, the sacrifice layer 60 serving as the base of the beam 30 and the support portion 20 is formed by using an arbitrary method such as metal mask and vapor deposition, photolithography, and plating. Further, a portion other than the sacrificial layer 60 is protected by a mask layer 70 such as a resist or a metal mask [FIG. 4(b)].

Next, on the sacrificial layer 60, a layer that will be the source of the beam 30 and the support portion 20 is formed by using an arbitrary method such as vapor deposition, CVD, or plating. This layer is processed by photolithography and an arbitrary method such as dry etching or wet etching to form the beam 30 and the support portion 20. Then, the sacrificial layer 60 and the mask layer 70 are removed [FIG. 2(c)]. Next, the beam side signal line 53, the long piece driving element 51, the short piece driving element 52, the terminal 11 and these elements are formed on the beam 30 by using an arbitrary construction method such as a metal mask and vapor deposition or photolithography and plating. Forming a wiring for connecting. [FIG. 2(d)] Thus, the microstructure is completed.

As described above, according to this embodiment, it is possible to manufacture a microstructure having a simple structure and a small energy required for the returning operation.

(Third Embodiment)
FIG. 5 is a cross-sectional view and a plan view showing the microstructure of the third embodiment. FIG. 5A is a sectional view taken along line BB′ of the plan view of FIG. In the microstructure of the present embodiment, the pedestal 42b is provided between the short piece driving means 42a and the substrate 10 to reduce the distance between the short piece driving means 42a and the short piece driving element 52. Other configurations are similar to those of the second embodiment.

As described in the second embodiment, the force generated by the short piece driving means 42a is a force that is inversely proportional to the square of the distance or a force that is inversely proportional to a function that increases faster than the square of the distance. Therefore, when the short piece driving means 42a of the present embodiment is used, when the same force is applied to the short piece driving element 52, the energy to be supplied should be smaller than that of the short piece driving means 42 of the second embodiment. You can For example, if the force generated by the short piece driving means 42a is an electrostatic force, the voltage to be supplied can be reduced.

Next, a method for manufacturing the microstructure of this embodiment will be described. 6 and 7 are a sectional view and a plan view showing this manufacturing method. First, each element of the substrate side signal line 43, the long piece driving means 41, and the short piece driving means 42 is formed on the substrate 101 by using an arbitrary construction method such as metal mask and vapor deposition, photolithography and plating. FIG. 6A].

Next, the pedestal 42b and the short piece driving means 42a are formed on the substrate 10 by using an arbitrary method such as metal mask and vapor deposition, photolithography and plating [FIG. 6(b)].

Next, the sacrifice layer 60 which will be the base of the beam 30 and the support portion 20 is formed by using an arbitrary method such as metal mask and vapor deposition, photolithography and plating [FIG. 6(c)]. At this time, depending on the formation process of the sacrificial layer 60 and the heights of the pedestal 42b and the short piece driving means 42a, the sacrificial layer 60 on the short piece driving means 42a is, as shown in FIG. Highly formed. In this case, the entire surface is protected by a resist 71 [FIG. 4(d)] and flattened by a method such as CMP [FIG. 7(e)]. Then, the resist 71 on the remaining sacrificial layer 60 is removed [FIG. 4(f)]. The resist removal part 72 processed here is shown in FIG.7(f).

Next, on the sacrificial layer 60, a layer that will be the source of the beam 30 and the support portion 20 is formed by using an arbitrary method such as vapor deposition, CVD, or plating. This layer is processed by photolithography and an arbitrary method such as dry etching or wet etching to form the beam 30 and the support portion 20. Then, the sacrificial layer 60 and the mask layer 70 are removed [FIG. 7(g)].

Next, on the beam 30, the beam side signal line 53, the long piece driving element 51, and the short piece driving element 52 are connected to these elements by using an arbitrary construction method such as a metal mask and vapor deposition or photolithography and plating. Wiring is formed [FIG.7(h)]. Thus, the microstructure of this embodiment is completed.

As described above, according to this embodiment, it is possible to obtain the microstructure in which the energy required for the returning operation is reduced.

(Fourth Embodiment)
FIG. 8 is a side view and a plan view showing the microstructure of the fourth embodiment. In the first to third embodiments, the structure in which the beam is integrated with the support part has been described, but the beam may not be integrated. For example, the beam may have a shaft at a position deviated from the center of the extending direction, and the supporting portion may have a bearing having the shaft.

FIG. 8 is a side view and a plan view showing an example of a microstructure having such a structure. As shown in FIGS. 8A and 8B, the beam 30a has a shaft 33a at a position displaced from the center of the extending direction. The support portion 20a has a hole into which a shaft 33a coupled to the beam 30a is inserted. Since the shaft support portion 20a rotatably supports the shaft 33a, the beam 30a forms a structure in which the long piece 31a and the short piece 32a shorter than the long piece 31a perform a seesaw operation. Operations similar to those in the embodiment can be performed.

As described above, according to the present embodiment, it is possible to configure a microstructure having a simple structure and a small energy required for the returning operation.

(Fifth Embodiment)
As shown in FIG. 3B of the second embodiment, in the microstructure of the second embodiment, when the short piece 32 is sucked toward the substrate 10, the long piece driving element located on the opposite side of the seesaw structure. The gap between 51 and the long piece drive means 41 becomes large. The increase in this gap increases the energy required for the long piece driving means 41 to drive the long piece 31. In this embodiment, a configuration for reducing this energy will be described.

FIG. 9 shows a cross-sectional view of a structure in which the cap 80 having the stopper 81 is covered with the microstructure of the second embodiment. The cap 80 is fixed to the substrate 10. In this fixed state, the stopper 81 is arranged so as to face the long piece 31 with a predetermined gap. The stopper 81 has a function of preventing the beam 30 from rotating more than a certain amount when the beam 30 rotates in the direction in which the beam side signal line 53 and the board side signal line 43 are separated from each other. The gap between the stopper 81 and the long piece 31 when the beam 30 is in a flat state can be appropriately determined. For example, when the short piece driving element 52 and the short piece are d2 during the ON operation (the end portion of the long side 31 is sucked by the long piece driving means 41), the long piece driving element 51 and the long piece driving during the OFF state are performed. The distance to the means 41 is set to be approximately the same as d2. With such a configuration, not only the energy at the time of restoration, but also the main operation, that is, the energy for attracting the long piece toward the substrate can be reduced. Since the long piece 31 receives a downward force from the stopper 81, it is desirable that the long piece 31 be formed of a flexible material so as not to be damaged by deformation. In addition, the stopper 81 and these elements are not in contact with each other so as not to electrically interfere with the beam-side signal line 53 and the long-piece driving element 51, or the stopper is made of a non-conductive material. Is desirable.

FIG. 10 is a sectional view showing a modified example of the configuration of FIG. In this example, the stopper 81a is supported by the stopper support 80a fixed to the substrate 10. The positional relationship between the stopper 81a and the long piece 31 may be the same as in FIG. With this configuration, the stopper 81a can be formed by the same method as the manufacturing method shown in FIG.

As described above, according to this embodiment, it is possible to configure the microstructure in which the energy for driving the long piece is reduced.

The present invention has been described above using the above-described embodiment as an exemplary example. However, the present invention is not limited to the above embodiment. That is, the present invention can apply various aspects that can be understood by those skilled in the art within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Base 2 Supports 2a, 21 Support shafts 3, 30 Beams 4, 41 Long piece drive means 5, 42 Short piece drive means 10 Board 11 Terminal 20 Support part 43 Board side signal line 51 Long piece drive element 52 Short piece drive element 53 Beam Side signal line 60 Sacrificial layer 70 Mask layer

Claims (10)

A substrate having rigidity,
A support body forming a support shaft parallel to the surface of the base body at a predetermined height of the base body;
The long piece having a long length from the support shaft to the end and the short piece having a short length from the support shaft to the end are supported by the support shaft and rotate with respect to the support shaft. With possible beams,
Long piece driving means fixed on the base body and generating a force for driving the long piece in the direction of the base body;
Fixed on the base body, and a short piece drive means for generating a force for driving the short piece in the direction of the base body,
The microstructure characterized in that the force generated by the short piece driving means is a force inversely proportional to the square of the distance, or a force inversely proportional to a function that increases faster than the square of the distance. The microstructure according to claim 1, wherein the force generated by the short piece driving means is an electromagnetic force. The microstructure according to claim 2, wherein the electromagnetic force is an electrostatic force. The microstructure according to claim 1, wherein a gap between the short piece and the short piece driving means is smaller than a gap between the long piece and the long piece driving means. The microstructure according to any one of claims 1 to 4, wherein the long piece has a stopper that restricts movement of the long piece in a direction away from the base body. 6. A movable-side long-piece driving element that forms a driving force in pairs with the long-piece driving means is provided at a position of the long piece corresponding to the long-piece driving means. The microstructure according to claim 1. 7. A movable-side short piece drive element that is paired with the short piece drive means to generate a driving force is provided at a position of the short piece corresponding to the short piece drive means. The microstructure of paragraph. A first electromagnetic element arranged on the long piece, and a second electromagnetic element arranged on the base body and interacting with the first electromagnetic element when the long piece approaches the base body. A first pair or a fourth electromagnetic element arranged on the short piece, and a fourth electromagnetic element arranged on the base body to bring the short piece closer to the base body to interact with the third electromagnetic element. The microstructure according to claim 1, further comprising at least one of a second pair including an electromagnetic element. Forming a support shaft parallel to the surface of the base at a predetermined height of the base having rigidity,
A long piece having a long length from the supporting shaft to the end and a short piece having a short length from the supporting shaft to the end are supported,
The beam is rotatable with respect to the support shaft,
Driving the strip in the direction of the substrate,
The force that drives the short piece in the direction of the base body and the short piece in the direction of the base body is a force that is inversely proportional to the square of the distance or a force that is inversely proportional to a function that increases faster than the square of the distance. A method for controlling a microstructure characterized by: The method for controlling a microstructure according to claim 9, wherein the force that drives the short piece in the direction of the base body is an electromagnetic force.

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