JP2001150392A - Semiconductor micro-actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor micro-actuator capable of reducing the energy necessary for displacing a movable element. SOLUTION: A movable element 2 having a rectangular peripheral edge is mounted inside of a frame-like supporting base 1 displaceably in the thickness direction of the supporting base 1. The supporting base 1 and the movable element 2 are connected through an arm member 3 capable of displacing the movable element 2 by its thermal expansion and contraction. The arm member 3 has a flexible part 8 obtained by stacking a flexible layer 7 on a flexible layer 6, and the flexible part 8 is deflected by the heat generated in accompany with the energization to the flexible layer 7, whereby displacing the movable element 2. The arm member 3 is connected to two sides along the longitudinal direction of the movable element, and extended in parallel with a central line along the lateral direction of the movable element 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor microactuator.

[0002]

2. Description of the Related Art Various miniature semiconductor microactuators manufactured by a semiconductor manufacturing process have been proposed. In this type of semiconductor microactuator, a movable element is generally arranged inside a frame-shaped support substrate made of a semiconductor, and the support substrate and the movable element are connected to each other via a flexible member having flexibility in a thickness direction of the support substrate. It has a linked structure. Therefore, the movable member can be displaced in the thickness direction of the support substrate by bending the flexible member in the thickness direction of the support substrate. As a configuration to bend the flexible member, a bimetal is formed by laminating a plurality of bending layers having different coefficients of thermal expansion, and the bimetal is directly heated (the bimetal itself has a heater) or indirectly heated (the bimetal is a bimetal). A configuration in which heating is performed using a separate heater is common.

A semiconductor microactuator of this type has a flexible member formed over the entire circumference of a mover, such as that described in Japanese Patent Application Laid-Open No. 4-506392, and Japanese Patent Application Laid-Open No. Hei 5-187574. The flexible member is radially formed as described in the above. As shown in FIGS. 4 and 5, an arm piece 3 as a flexible member is connected to four sides of the mover 2 having a peripheral edge formed in a rectangular shape, and the mover 2 is connected via the arm piece 3. A configuration connected to the frame-shaped support substrate 1 is also considered. When each arm 3 is linear as shown in FIGS. 4 and 5, the arm 3 is formed so as to form a cross with the movable element 2 as a center.
Furthermore, in order to make the arm piece 3 easily bendable by forming the arm piece 3 long, it is also conceivable to form each arm piece 3 into a substantially L-shape. In this case, a swastika shape is formed around the mover.

[0004]

In the conventional semiconductor microactuator described above, the movable element 2 is
Since the movable member 2 is restrained from a number of directions since the flexible member is formed in more than the direction, relatively large energy is required to displace the movable member 2. For example, when the arm pieces 3 are arranged in a cross shape, the thermal expansion of the arm pieces 3 occurs not only in the extending direction of the arm pieces 3 but also in the width direction. The joint between the arm piece 3 and the arm piece 3 is curved along the width direction of the arm piece 3 when viewed microscopically. As a result, the arm 3 is less likely to bend, and the energy for displacing the mover 2 increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor microactuator that requires less energy to displace a mover than before.

[0006]

According to a first aspect of the present invention, there is provided a frame-shaped support substrate made of a semiconductor, a movable element made of a semiconductor disposed inside the support substrate and capable of being displaced in the thickness direction of the support substrate, and Arm for connecting the armature and the support substrate, and having flexibility in the thickness direction of the support substrate and displacing the armature by thermal expansion and contraction, wherein the arm arm is parallel to one center line of the armature. It has been extended. According to this configuration, since the arm piece extends in parallel with one center line of the mover, the arm piece extends in one or two directions from the mover, and the mover is restrained. Since the direction of movement is smaller than in the conventional configuration, the mover can be displaced with lower energy than in the conventional configuration. In other words, the displacement of the mover with respect to the supplied energy is larger than in the conventional configuration.

According to a second aspect of the present invention, in the first aspect of the invention, the support substrate has a rectangular frame shape, and a periphery of the movable element has a rectangular shape parallel to each side of the support substrate. The piece is connected to two opposing sides of the mover and extends in a direction parallel to the other two sides. According to this configuration, since the planar shape is simple, manufacturing in a semiconductor manufacturing process is facilitated.

According to a third aspect of the present invention, in the second aspect of the invention, two arm pieces are connected to each side of the mover,
It is arranged symmetrically with respect to one center line of the mover. According to this configuration, since the arm has two pieces in each direction, the mover can be moved in parallel.

According to a fourth aspect of the present invention, in the third aspect of the present invention, there is provided a guide for restricting the moving direction of the movable element by slidingly contacting two sides of the periphery of the movable element to which the arm pieces are not connected. Things. According to this configuration, the moving direction of the mover is regulated by the guide, and the moving direction is stabilized.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the arm has a flexible portion in which a plurality of flexible layers having different coefficients of thermal expansion are stacked, And a connecting portion for thermal insulation. According to this configuration, the flexible portion functions as a bimetal, and the amount of bending can be increased. Moreover, since the flexible portion is thermally insulated from the support substrate, the flexible portion can be bent with relatively small heat energy. That is, the displacement amount of the mover with respect to the supplied energy can be increased.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the flexible portion includes a bimetal in which a flexible layer made of a semiconductor and a second flexible layer made of a metal film are overlapped, and a heating section for heating the bimetal. And a bending section that changes the amount of bending according to the amount of current supplied to the heating section. According to this configuration, since the flexible portion is flexed by the direct heat type bimetal, the size can be reduced, and the heat energy can be efficiently transmitted to the flexible portion. Can be displaced.

According to a seventh aspect of the present invention, in the invention of the sixth aspect, a heat insulating portion for thermally insulating the movable element and the flexible portion is provided on the arm piece. According to this configuration, since the flexible portion and the mover are thermally insulated, the supplied thermal energy can efficiently act on the flexible portion to bend the flexible portion. That is, the displacement of the mover with respect to the supplied energy can be further increased.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments described below, a microvalve using a semiconductor microactuator is exemplified. However, the application of the microactuator is not limited to the microvalve. It can also be used as a source.

(First Embodiment) As shown in FIG. 1, a semiconductor microactuator according to the present embodiment is a movable member made of silicon as a valve element for opening and closing a valve port 11 formed in a base 10 made of a silicon substrate. The valve port 11 is opened and closed by moving the mover 2 in a direction perpendicular to the opening surface of the valve port 11. The mover 2 is formed in a truncated quadrangular pyramid shape, and a surface facing the valve port 11 is flat.
Here, the plane shape of the mover 2 is rectangular as shown in FIG. A valve seat 12 protruding from other parts is formed on a surface of the valve port 11 facing the mover 2 at a position facing the mover 2. Finished flat so that it can be closed. Then
In the present embodiment, the valve port 11 is opened in a rectangular shape.

The mover 2 is connected to a support substrate 1 which is overlapped and joined to a base 10 via an arm 3 as a flexible member. The support substrate 1 is formed in a rectangular frame shape, and the mover 2 is arranged inside the support substrate 1. Also,
In the present embodiment, four arm pieces 3 that couple the support substrate 1 and the mover 2 are provided, and two arm pieces 3 are provided on two of the peripheral edges of the mover 2 along the longitudinal direction of the mover 2. Are connected (see FIG. 2). Each arm 3 is arranged so as to be symmetric with respect to the center line along the lateral direction of the mover 2. Therefore, when the movable element 2 is displaced in the thickness direction of the support substrate 1 due to the expansion and contraction of the arm piece 3, the movable element 2 can be moved in parallel if the amount of expansion and contraction of each arm piece 3 is equal. The mover 2 can be brought into close contact with 11 without any gap.

A connecting portion 4 is provided at an end of the arm piece 3 on the support substrate 1 side, and a heat insulating section 5 is provided at an end of the arm piece 3 on the movable element 2 side. The connecting portion 4 is mainly formed using a synthetic resin such as a polyimide resin having a higher thermal insulation performance than silicon, and a portion made of silicon is provided at an end in the width direction. The portion made of silicon can be used for electrical connection with a heating section described later. The heat insulating portion 5 is formed using a synthetic resin such as a polyimide resin having a higher heat insulating performance than silicon.
The portion of the arm piece 3 between the connecting portion 4 and the heat insulating portion 5 may be provided with a bimetal formed by laminating a flexible layer 6 made of silicon and a flexible layer 7 made of a metal film of aluminum or nickel. A heating section (not shown) as a heater for heating the bimetal is formed on the flexible layer 8 of the flexible section 8 by diffusion resistance. That is, the flexible portion 8 functions as a direct heat type bimetal. Here, in order to prevent the flexible layer 7 from diffusing into the flexible layer 6, to increase the bonding force between the flexible layer 6 and the flexible layer 7, and to insulate the heating section from the flexible layer 7, It is desirable that a material be appropriately interposed between the flexible layer 6 and the flexible layer 7.

The arm 3 has the above-described structure,
When the heating section is energized, the flexible section 8 changes the amount of bending of the arm piece 3 due to thermal expansion and contraction due to a difference in expansion coefficient between the flexible layer 6 and the flexible layer 7. Generally, metal has a larger expansion coefficient than silicon, and therefore, as in this embodiment, the flexible layer 6
When the flexible layer 7 is formed on the side opposite to the base 10, the size is set so that the mover 2 is separated from the valve port 11 at normal temperature, so that the flexible layer 7 It is possible to close the valve port 11 by bringing the mover 2 close to the valve port 11 during energization. That is, the present embodiment constitutes a normally-open microvalve.

Further, a connecting portion 4 mainly made of synthetic resin is formed at one end of the arm piece 3 and a heat insulating portion 5 made of synthetic resin is formed at the other end, so that the bending layer 6 and the bending The bimetal composed of the layer 7 is thermally insulated from the support substrate 1 and the movable element 2, so that the heat generated in the bending portion 6 does not escape to the support substrate 1 and the movable element 2, and most of the heat is transferred to the arm piece. 3 can be used to flex. As a result, it is possible to increase the amount of bending of the arm piece 3 with respect to the amount of electricity supplied to the heating unit. In other words, the mover 2 can be operated with low power.
Can be displaced by a desired amount.

By the way, as described above, two arms 3 are extended from two sides along the longitudinal direction of the mover 2 and each arm 3 is parallel. Are not constrained in the left-right direction. Therefore, even if there is a variation in the amount of deformation of the flexible portion 8 with respect to the amount of electricity supplied to the heating section, the movable element 2 is hardly restrained by the flexible portion 8 having a small amount of deformation, and the movable element 2 2 can be displaced. That is, the displacement amount of the mover 2 with respect to the supplied energy can be made larger than in the conventional configuration.

In the above example, the base 10 is a silicon substrate, but a glass substrate may be used.

(Second Embodiment) In this embodiment, FIG.
As shown in (1), guides 9 are provided to be in sliding contact with two sides of the periphery of the mover 2 along the lateral direction, and the guide 9 regulates the moving direction of the mover 2. The guide 9 is connected to the support substrate 1 and is formed of a material with good slip so as not to hinder the movement of the mover 2.

As described above, since the guide 9 is provided to regulate the moving direction of the movable element 2, the movable element 2 moves without tilting even if the bending amount of the arm piece 3 varies, and the valve port 11 is closed. It can be securely closed. Other configurations and operations are the same as those of the first embodiment.

[0023]

According to the first aspect of the present invention, there is provided a frame-shaped support substrate made of a semiconductor, a movable element made of a semiconductor disposed inside the support substrate and capable of being displaced in a thickness direction of the support substrate, a movable element and the support substrate. And an arm that is flexible in the thickness direction of the support substrate and displaces the mover by thermal expansion and contraction, the arm extending parallel to one center line of the mover. The arm piece extends in one or two directions from the mover by extending the arm piece in parallel with one center line of the mover, and the direction in which the mover is restrained. Is smaller than in the conventional configuration, so that there is an advantage that the mover can be displaced with lower energy than in the conventional configuration. In other words, the displacement of the mover with respect to the supplied energy is larger than in the conventional configuration.

According to a second aspect of the present invention, in the first aspect, the support substrate has a rectangular frame shape, and a periphery of the movable element has a rectangular shape parallel to each side of the support substrate. The armature is connected to two opposing sides of the mover and is extended in a direction parallel to the other two sides. The simple shape of the plane makes it easy to manufacture in a semiconductor manufacturing process. is there.

According to a third aspect of the present invention, in the second aspect of the invention, two arm pieces are connected to each side of the mover.
Since the armature is arranged symmetrically with respect to one center line of the armature and has two arm pieces in each direction, there is an advantage that the armature can be moved in parallel.

According to a fourth aspect of the present invention, in the third aspect of the present invention, there is provided a guide for restricting the moving direction of the mover by slidingly contacting two sides of the periphery of the mover to which the arm pieces are not connected. This has the advantage that the moving direction of the mover is regulated by the guide and the moving direction is stabilized.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the arm piece has a flexible portion in which a plurality of flexible layers having different coefficients of thermal expansion are stacked; And a connecting portion for heat insulation. The flexible portion functions as a bimetal to increase the amount of bending, and the flexible portion is thermally insulated from the supporting substrate. Therefore, there is an advantage that the flexible portion can be bent with relatively small heat energy. That is, the displacement amount of the mover with respect to the supplied energy can be increased.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the flexible portion includes a bimetal in which a flexible layer made of a semiconductor and a second flexible layer made of a metal film are stacked, and a heating section for heating the bimetal. The flexible part is bent by the direct heat type bimetal, so that it is possible to reduce the size and to use heat energy. There is an advantage that the movable member can be displaced with a small supply energy, because the movable member can be efficiently transmitted to the flexible portion.

According to a seventh aspect of the present invention, in the invention of the sixth aspect, a heat insulating portion for thermally insulating the movable element and the flexible portion is provided on the arm piece. Since the movable element is thermally insulated, there is an advantage that the supplied thermal energy can efficiently act on the flexible portion to bend the flexible portion. That is, the displacement of the mover with respect to the supplied energy can be further increased.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a first embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a plan view showing a second embodiment of the present invention.

FIG. 4 is a partially broken perspective view showing a conventional example.

FIG. 5 is a plan view of the same.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support substrate 2 mover 3 arm piece 4 connecting part 5 heat insulating part 6 flexible layer 7 flexible layer 8 flexible part 9 guide

Continued on the front page (72) Inventor Kenji Toyoda 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Inventor Keiko Fujii 1048 Odaka Kadoma Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Invention Person Yoshiaki Tomonari 1048 Kazuma Kadoma, Kadoma City, Osaka Prefecture (72) Inventor Hiroshi Kawada 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Works Co., Ltd. (72) Inventor Jin Yoshida Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Masayu Kamakura, Kazumasa Kamakura, Osaka, Japan 1048 Matsushita Electric Works Co., Ltd., Kazumasa Yoshida Kazushi Yoshida 1048, Matsushita Electric Works, Kazuma, Kadoma, Osaka Prefecture Within a stock company

Claims (7)

[Claims] 1. A frame-shaped support substrate made of a semiconductor, a movable element made of a semiconductor disposed inside the support substrate and capable of being displaced in a thickness direction of the support substrate, a movable element and the support substrate being connected to each other. An arm piece having flexibility in the thickness direction and displacing the mover by thermal expansion and contraction, wherein the arm piece is extended in parallel with one center line of the mover. Actuator. 2. The method according to claim 1, wherein the supporting substrate has a rectangular frame shape, and a periphery of the movable element has a rectangular shape parallel to each side of the supporting substrate.
2. The semiconductor microactuator according to claim 1, wherein the arm pieces are respectively connected to two opposing sides of the mover and extend in a direction parallel to the other two sides. 3. The semiconductor according to claim 2, wherein two arm pieces are connected to each side of the mover, and are arranged symmetrically with respect to one center line of the mover. Micro actuator. 4. The semiconductor micro-device according to claim 3, wherein a guide is provided to regulate the moving direction of the mover by slidingly contacting two sides of the periphery of the mover to which the arm pieces are not connected. Actuator. 5. The arm piece comprises: a flexible portion in which a plurality of flexible layers having different coefficients of thermal expansion are stacked; and a connecting portion which connects the flexible portion and the support substrate and thermally insulates the flexible portion. The semiconductor microactuator according to any one of claims 1 to 4, wherein 6. The heating device according to claim 6, wherein the flexible portion includes a bimetal in which a first flexible layer made of a semiconductor and a second flexible layer made of a metal film are stacked, and a heating portion that heats the bimetal. 6. The semiconductor microactuator according to claim 5, wherein the amount of deflection is changed according to the amount of current. 7. The semiconductor microactuator according to claim 5, wherein a heat insulating portion for thermally insulating between the mover and the flexible portion is provided on the arm piece.