JP2002138946A - Semiconductor microactuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor microactuator capable of surely obtaining a displacement and a driving force of a movable portion with a low electric power consumption. SOLUTION: This semiconductor microactuator comprises a semiconductor substrate 3; at least one flexible portion 2 connected to the semiconductor substrate 3, and displacing in a given direction in accordance with variation of a temperature; a movable portion 1 suspended by the flexible portion 2 and displacing in accordance with variation of the flexible portion 2; and at least one stopper portion 4 preventing at least one of the flexible portion 2 and the movable portion 1 from displacing in an opposite direction to the given direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor microactuator for obtaining a displacement of a movable portion by using a displacement of a flexible portion.

[0002]

2. Description of the Related Art In a conventional semiconductor microactuator, for example, a flexible portion has a bimetal structure in which at least two materials having different coefficients of thermal expansion are combined. There is a method of obtaining the displacement of the movable part using the difference. This type is described in JP-A-2000-246676.

Here, the bimetal structure is shown in FIG.
As shown in FIG. 10B, at least two materials having different coefficients of thermal expansion are bonded together or brought into contact so as to overlap with each other. In principle, when heat is applied to the bimetal structure portion, the structure shown in FIG. As shown, a driving force is generated such that the material 50 having a large coefficient of thermal expansion expands and the material 51 having a small coefficient of thermal expansion contracts.

FIG. 9 shows the structure of the semiconductor microactuator described in the above publication, FIG. 9 (a) is a sectional view, FIG. 9 (b) is a top view, and FIG. It is a perspective view of a fracture.

The following is an explanation based on FIG. The semiconductor microactuator as described above is a semiconductor substrate 3 having a hollow, substantially square frame made of silicon or the like.
And an inclined portion 9 which is joined to the inside thereof at four places via suspension means 5 and is suspended from the semiconductor substrate 3 via beams 6.
And a boss 7.

The movable part 1 has an inclined part 9 and a boss 7 and is made of silicon.
It is formed in a hollow truncated pyramid shape so that the opening is formed in a square shape and the width of the inclined portion 9 becomes narrower downward, and a boss 7 is formed in the center. The one-piece beam 6 made of four silicons extends outwardly from each of the four sides of the opening on the upper surface of the movable portion 1 to support the movable portion 1. Each of the four beams 6 forms a substantially cross shape with the inclined portion 9 and the boss 7 interposed therebetween.

[0007] The flexible portion 2 has a suspension means 5 and a beam 6, and the suspension means 5 and the beam 6 are arranged in contact with each other so as to overlap each other. Then, the suspension means 5 made of polyimide, fluorinated resin, or the like, which is formed in contact with the upper part of the beam 6 so as to overlap with the upper part of the beam 6, is joined to the surface of the semiconductor substrate 3,
The semiconductor substrate 3 and the movable section 1 are joined. Further, the beam 6 has a heating means 8 including a diffusion resistance for heating the beam 6.
Is provided.

Here, in order to displace the movable portion 1 in the direction indicated by the arrow A in FIG. 9A, the thermal expansion coefficient of the suspension means 5 needs to be larger than the thermal expansion coefficient of the beam 6. . For example, when the suspension means 5 is made of polyimide and the beam 6 is made of silicon, the coefficient of thermal expansion of the polyimide is 2.2 ×
10 ⁻⁵ / K, and the thermal expansion coefficient of silicon is 3.0 ×
10 ⁻⁶ / K. The coefficient of thermal expansion of polyimide is about seven times that of silicon. By heating the beam 6 by the heating means 8, a driving force is generated such that the suspension means 5 expands and the beam 6 contracts, and the movable part 1 is displaced in the direction indicated by the arrow A.

[0009]

However, in the above-mentioned semiconductor microactuator, the suspension means 5 and the beam 6 are deformed due to defective initial molding or external force, so that the suspension means 5 having a large thermal expansion coefficient is elongated. The beam 6 having a small coefficient of thermal expansion may not be displaced in the contracting direction but may be displaced in the opposite direction. Therefore, there is a problem that more power consumption is required than in normal operation in order to obtain the target displacement and driving force.

In the case where a plurality of materials such as the suspension means 5 and the beam 6 are arranged so as to be in contact with each other so as to overlap each other as in the case of the semiconductor microactuator described above, the flexible portion 2 is formed. When the fixed state of each material end is unstable, the movable part 1 may be deformed temporarily and convexly in the direction opposite to the displacement direction immediately after the start of the deformation. Therefore, there is a problem that more power consumption is required than in normal operation in order to obtain the target displacement and driving force.

The present invention has been made to solve the above problems, and has as its object to provide a semiconductor microactuator capable of reliably obtaining displacement and driving force of the movable unit 1 with low power consumption. It is assumed that.

[0012]

According to a first aspect of the present invention, there is provided a semiconductor microactuator, comprising: a semiconductor substrate; and at least one flexible portion joined to the semiconductor substrate and displaced in a predetermined direction in accordance with a temperature change. And a movable part 1 suspended by the flexible part 2 and displaced in accordance with a change of the flexible part 2
And at least one stopper portion 4 for preventing at least one of the flexible portion 2 and the movable portion 1 from being displaced in a direction opposite to the predetermined direction. It is.

According to a second aspect of the present invention, in the semiconductor microactuator according to the first aspect, the stopper portion has a projection portion, and the projection portion faces the movable portion. It is characterized by having been provided.

According to a third aspect of the present invention, in the semiconductor microactuator according to the first aspect, the stopper portion has a projection portion, and the projection portion faces the flexible portion. It is characterized by having been provided.

According to a fourth aspect of the present invention, in the semiconductor microactuator according to the third aspect, the stopper portion has a plate-like structure, and the stopper portion and the flexible portion are provided. And are arranged so as to overlap with each other.

According to a fifth aspect of the present invention, in the semiconductor microactuator according to the third aspect, the stopper portion 4 adjusts an arrangement position of the movable portion 1 in a direction substantially perpendicular to a displacement direction of the movable portion 1. It is characterized by having a function.

According to a sixth aspect of the present invention, in the semiconductor microactuator according to the second, third, or fifth aspect, the stopper portion 4 is arranged so that the stopper portion 4 is substantially in the direction of displacement of the movable portion 1. It has a function of adjusting a horizontal arrangement position.

According to a seventh aspect of the present invention, in the semiconductor microactuator according to the second, third, or sixth aspect, at least the flexible portion 2 or the movable portion 1 in the stopper portion 4 is provided. The thermal conductivity of the protrusion 41 for preventing the displacement of the flexible portion 2 or the movable portion 1 in the opposite direction by contacting with the flexible portion 2 or the flexible portion 2 at the position where the protrusion 41 contacts. It is characterized in that the thermal conductivity is equal to or less than the thermal conductivity of the movable part 1.

According to an eighth aspect of the present invention, in the semiconductor microactuator according to the seventh aspect, the material forming the protrusion 41 is glass.

A semiconductor microactuator according to a ninth aspect of the present invention is the semiconductor microactuator according to the seventh aspect, wherein the material forming the tip end portion 42 of the projection 41 is polyimide. .

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The premise of the present invention will be described below with reference to FIG.
It will be described based on. Although the arrangement of each part of the semiconductor microactuator has been described in the related art, only necessary parts will be described again. In the following embodiments, a semiconductor microactuator having the structure shown in FIG. 9 is commonly used, but is not limited to this structure.

As described above, the semiconductor microactuator includes a semiconductor substrate 3 made of silicon or the like, which is a hollow and substantially rectangular frame, a movable part 1 having an inclined part 9 and a boss 7, and a movable part. 1 and a flexible portion 2 formed by contacting the suspension means 5 so as to overlap with each other, and the suspension means 5 is joined to the surface of the semiconductor substrate 3 so that the semiconductor substrate 3 The movable portion 1 is configured to be joined. Further, the beam 6 is provided with a heating means 8 composed of a diffusion resistance or the like for heating the beam 6. In the following embodiment of the present invention, a heating means 8 of a type in which an electric current (not shown) is applied to heat the beam 6 is used.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a structure of a semiconductor microactuator according to a first embodiment of the present invention, and FIG.
1A is a cross-sectional view, and FIG. 1B is a top view. First, the configuration of the stopper portion 4 will be described with reference to FIG.

The stopper portion 4 has an L-shaped end portion, a support portion 43 having both end portions joined to the semiconductor substrate 3, and a conical projection 41 provided substantially at the center of the support portion 43. Do it. In addition, the protrusion 41 is disposed toward the boss 7 that constitutes the movable portion 1, and as shown in FIG. 1A, the tip of the protrusion 41 does not press against the boss 7 or the boss 7. It is configured to be disposed at a position in contact with

The semiconductor substrate 3 and the movable portion 1 are made of silicon, the suspension means 5 is made of polyimide, the coefficient of thermal expansion of silicon is 3.0 × 10 ⁻⁶ / K, and the coefficient of thermal expansion of polyimide is 2.2 × 10 ⁻⁵ / K.

Here, the suspension means 5 is made of polyimide, but the material is not limited to this, and has a heat insulating function, and is a material constituting the movable portion 1, in this embodiment, silicon. It is sufficient that the thermal expansion coefficient is different from the thermal expansion coefficient of the beam. Particularly, the thermal expansion coefficient of the suspension means 5 is larger than the thermal expansion coefficient of the beam 6, and it is desirable that the difference between the thermal expansion coefficients is large. .

The support 43 is made of aluminum, and the projection 41 is made of glass. The thermal conductivity of glass is 0.55 W / mK, and the thermal conductivity of silicon is
148 W / mK.

The shape of the protruding portion 41 is conical, but the shape is not limited to this, and the movable portion 1
Any other shape such as a conical shape, a columnar shape, or a spherical shape may be used as long as it restricts the movement of the boss 7 (especially, the boss 7). The projection 41 is made of glass, but the material is not limited to glass. Preferably, the projection 41 is made of a material having a thermal conductivity smaller than that of the movable portion 1 (particularly, the boss 7). Escapes from the movable portion 1 (especially, the boss 7) to the protruding portion 41, thereby reducing power consumption. In addition, the support portion 43
Although aluminum was used, the material is not limited to this, and any material having high rigidity such as metal or glass may be used.

The operation will be described below. First, at the time of normal operation, the beam 6 is heated by the heating means 8 so that the suspension means 5 is expanded, the beam 6 is contracted, and the movable part 1 is also moved according to the change of the flexible part 2 as indicated by an arrow in FIG. A is displaced in the direction shown in FIG. In this case, the protrusion 41 is in a state where the movement of the movable portion 1 is not hindered.

FIG. 2 shows the result of simulating the relationship between the power consumption and the displacement of the movable portion 1 (boss 7) using the finite element method. The horizontal axis represents the power consumption, and the vertical axis represents the movable amount. The displacement amount of the portion 1 (boss 7) is taken.

In FIG. 9, a state in which initial deformation failure is applied to the movable portion 1 (boss 7) in the direction opposite to the arrow A is set as an initial state, and the stopper section 4 of the present embodiment is added to the initial state. The case in which the stopper portion 4 is provided is denoted by a, and the case in which the stopper portion 4 is not provided is denoted by b. As can be seen from FIG. 2, the displacement amount at the same power consumption is larger in the case of a than in the case of b. From FIG. 2, in order to obtain the displacement amount L of the same movable portion 1 (boss 7), W1 (W) is necessary in the case of a,
In the case of b, W2 (W) is required. Here, W1 is
It is smaller than W2. From the above, it can be seen that the stopper portion 4 is effective in reducing power consumption.

In such a semiconductor microactuator, when the movable portion 1 has an initial molding defect, the defective portion is suppressed, and when the movable portion 1 is deformed by an external force, the deformation is suppressed. it can. Further, when an external force is excessively applied in a direction opposite to the arrow A,
The movable part 1 can be prevented from being damaged. In addition, as described above, the suspension means 5 and the beam 6 are not displaced in the direction of the arrow A due to initial molding failure or deformation due to external force, and therefore, when the movable part 1 is displaced in the opposite direction, the protrusions are formed. 41 restricts the movement of the movable part 1 and can prevent the movable part 1 from being displaced in the direction opposite to the arrow A. Further, by setting the thermal conductivity of the protrusion 41 to be equal to or less than the thermal conductivity of the movable portion 1, the heat dissipation from the movable portion 1 to the protrusion 41 is reduced by the heat insulating effect, so that the power consumption can be reduced. it can.

Hereinafter, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the stopper 4 of the first embodiment has a function of adjusting the gap between the tip of the projection 41 and the boss 7. 3A and 3B show a structure of a semiconductor microactuator according to a second embodiment of the present invention. FIG. 3A is a sectional view, and FIG. 3B is a top view. Except for a part of the configuration of the stopper portion 4, the configuration is the same as that of the first embodiment, and the description of the common portion is omitted.
First, the configuration of the stopper portion 4 will be described with reference to FIG.

The stopper portion 4 has an L-shape at both ends and has a support portion 43 having both ends joined to the semiconductor substrate 3, and is provided substantially at the center of the support portion 43 so as to be screwed with the support portion 43. And a conical protrusion 41. Further, the protrusion 41 is configured to be disposed toward the boss 7.
The support portion 43 is provided with a hole through which the protrusion 41 is passed, and a female screw (not shown) is provided in the hole, and a male screw (not shown) is provided in a part of the protrusion 41 (near the hole). And screw each other.

Here, the support portion 43 does not need to be a female screw. For example, a method may be employed in which a male screw provided on the projection 41 engages while threading the support portion 43. What is necessary is just to have a function of adjusting the arrangement position of the projection 41 in a direction substantially horizontal to the displacement direction.

The operation will be described below. When there is deformation due to defective initial molding or external force, the shape of the movable portion 1 and the like varies between products, and the distance between the support portion 43 and the movable portion 1 may differ between products. In such a case, the gap between the tip of the projection 41 and the boss 7 may not be constant. Therefore, the gap is adjusted by turning the head of the projection 41, and the projection 41 is
Of the boss 7 or a position where the boss 7 comes into contact without being pressed.

In the semiconductor microactuator, in addition to the effects of the first embodiment, the gap can be easily adjusted even when there is a variation between products due to defective initial molding.

Hereinafter, a third embodiment of the present invention will be described with reference to FIG. 4A and 4B show the structure of a semiconductor microactuator according to a third embodiment of the present invention. FIG. 4A is a sectional view, and FIG. 4B is a top view. First, the configuration of the stopper portion 4 will be described with reference to FIG.

The stopper portion 4 has an L-shaped end toward each of the two suspension means 5 opposed to each other with the boss 7 interposed therebetween, and a support portion 43 having the end joined to the semiconductor substrate 3; 43, and a conical projection 41 provided at the other end. Further, the protrusion 41 is provided toward the suspension means 5 constituting the flexible part 2, and as shown in FIG. 4A, the tip of the protrusion 41 is in the vicinity of the suspension means 5 or the suspension means 5. Is placed in a position where it touches without pressure.

The semiconductor substrate 3 and the movable part 1 are made of silicon, and the suspension means 5 is made of nickel. Nickel has a thermal expansion coefficient of 1.5 × 10 ⁻⁵ / K, which is about five times that of silicon. The support 43 is made of aluminum, and the protrusion 41 is made of glass. The thermal conductivity of nickel is 90 W / mK.

Here, similarly to the first embodiment, the protrusion 41
The material and the material of the supporting portion 43 are not limited to those shown in the second embodiment.

The operation will be described below. First, at the time of normal operation, by heating the beam 6 by the heating means 8, the suspension means 5 is extended, the beam 6 is contracted, and the movable part 1 is displaced in the direction shown by the arrow A in FIG. In this case, the projection 4
Reference numeral 1 denotes a state in which the movement of the suspension means 5 constituting the flexible portion 2 is not hindered.

In such a semiconductor microactuator, if there is an initial molding defect in the flexible portion 2, the defective portion can be suppressed. In the case of an abnormal operation in which the flexible portion 2 is temporarily deformed in a direction opposite to the direction of the arrow A immediately after the start of the deformation as described above, the protrusion 41 restricts the movement of the suspension means 5. However, it is possible to prevent the flexible portion 2 from being displaced in the direction opposite to the arrow A. Further, by setting the thermal conductivity of the projection 41 to be equal to or less than the thermal conductivity of the flexible portion 2, heat is prevented from escaping from the flexible portion 2 to the projection 41 due to a heat insulating effect, and power consumption is reduced. be able to.

Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG. In the fourth embodiment, the stopper 4 of the third embodiment has a function of adjusting the gap between the tip of the projection 41 and the suspension means 5. FIG. 5 shows a structure of a semiconductor microactuator according to a fourth embodiment of the present invention, FIG. 5 (a) is a sectional view, and FIG.
Is a top view. Except for a part of the configuration of the stopper portion 4, the configuration is the same as that of the third embodiment, and the description of the common portion is omitted. First, the configuration of the stopper 4 will be described with reference to FIG.

The stopper portion 4 has an L-shaped end at both ends, and a first support portion 45 having both ends joined to the semiconductor substrate 3.
And a conical projection 41 provided toward each of the two suspension means 5 opposed to each other with the boss 7 interposed therebetween, and an L-shaped end having both ends joined to the first support portion 45 for adjustment. The first support portion 45 includes a second support portion 46 provided with a portion 47, and an adjustment portion 47 provided toward a substantially central portion of the first support portion 45. The adjustment unit 47
The distance between the first support 45 and the second support 46 is adjusted, and the distance between the protrusion 41 and the suspension means 5 is adjusted. The second support portion 46 is provided with a hole through which the adjustment portion 47 passes, and a female screw (not shown) is provided in the hole portion, and a male screw (not shown) is provided in a part (near the hole portion) of the adjustment portion 47. , Are provided and screw each other.

Here, the second support portion 46 does not need to be a female screw. For example, a method in which a male screw provided on the adjusting portion 47 engages while cutting the second support portion 46 may be used. What is necessary is just to have a function of adjusting the arrangement position of the protrusion 41 in a direction substantially horizontal to the direction of displacement of the movable part 1.

The first support part 45, the second support part 46, and the adjustment part 47 are made of aluminum. The adjustment section 47
It has a conical shape provided substantially at the center of the support portion 46 so as to be screwed with the support portion 46. Note that the first support portion 45,
Although aluminum was used for the second support portion 46 and the adjustment portion 47, the material is not limited to this, and any material having high rigidity such as metal or glass may be used.

The operation will be described below. When there is deformation due to poor initial molding or external force, the shape of the flexible portion 2 and the like varies between products, and the first support portion 45 and the movable portion 1
Distance may differ between products. In such a case, the gap between the tip of the projection 41 and the suspension means 5 may not be constant. By turning the head of the adjusting part 47, the gap is adjusted, and the protruding part 41 is brought close to the vicinity of the suspension means 5 or to a position where the suspension means 5 comes into contact with the suspension means 5 without being pressed.

In this semiconductor microactuator, in addition to the effects of the third embodiment, even when there is a variation between products due to defective initial molding or the like, the projection 41
The distance between the flexible part 2 and the flexible part 2 can be easily adjusted. Further, even when a plurality of flexible portions 2 are provided in one semiconductor microactuator, all the flexible portions 2 provided with the protruding portions 41 are provided.
(In the present embodiment, the protrusions 41 are provided toward two of the four flexible portions 2).

Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 shows a structure of a semiconductor microactuator according to a fifth embodiment of the present invention, where FIG. 6A is a sectional view and FIG. 6B is a top view. The following is a description of the configuration and operation of the stopper unit 4 with reference to FIG.

The stopper portion 4 has an L-shape at each end and a plate-like structure at the other end, and only the both ends are formed on the semiconductor substrate 3.
, And are arranged so as to overlap or be in contact with each other without being joined to the upper part of the suspension means 5. Semiconductor substrate 3
The movable part 1 is made of silicon, and the suspension means 5 is made of nickel. The stopper 4 is made of glass.

Although the stopper portion 4 is made of glass, the material is not limited to glass, and any material having high rigidity such as metal may be used. If the material has a lower thermal conductivity, the escape of heat from the suspension means 5 to the stopper portion 4 is reduced, and power consumption is reduced.

The lower surface of the stopper portion 4 restrains the movement of the suspension means 5 constituting the flexible portion 2, and the flexible portion 2 is moved as shown in FIG.
In the direction opposite to the direction of arrow A.

In such a semiconductor microactuator, the formation of the stopper portion 4 is easy. In addition, since the stopper portion 4 is made of glass, sufficient hardness can be secured, so that wear due to repeated use can be reduced. Further, by setting the thermal conductivity of the stopper portion 4 to be equal to or less than the thermal conductivity of the flexible portion 2, heat dissipation from the stopper portion 4 to the flexible portion 2 is reduced by a heat insulating effect, so that power consumption is reduced. be able to.

Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG. In the sixth embodiment, the stopper portion 4 of the third embodiment has a function of adjusting the position of the projection 41 in a direction substantially perpendicular to the direction of displacement of the movable portion 1. 7A and 7B show the structure of a semiconductor microactuator according to a sixth embodiment of the present invention. FIG. 7A is a sectional view, and FIG. 7B is a top view. Except for a part of the configuration of the stopper portion 4, the configuration is the same as that of the third embodiment, and the description of the common portion is omitted. The following is a description of the configuration and operation of the stopper unit 4 using FIG.

The stopper portion 4 has an L-shaped end and has a support portion 43 whose end is joined to the semiconductor substrate 3 and a support portion having the other end as a free end toward a portion where the flexible portion 2 exists. 43
And a long hole 48 provided substantially in parallel with the surface of the flexible portion 2.

The projection 41 moves along the long hole 48 to adjust the position of the projection 41. A concave portion (not shown) is provided in the long hole portion 48, and a convex portion (not shown) is provided in a part (near the groove portion) of the projection portion 41. Do not get out of the hole 48.

Here, the projection 41 and the elongated hole 48 are not limited to such an engagement relationship, and the arrangement of the projection 41 is substantially perpendicular to the direction of displacement of the movable part 1 (the direction of arrow A). What is necessary is just to have the function to adjust a position.

The projection 41 or the elongated hole 48 may have a function of fixing the projection 41 at the position of the projection 41 once the position of the projection 41 is determined.

In such a semiconductor microactuator, in addition to the effects of the third embodiment, when one semiconductor microactuator has a plurality of flexible portions 2, each flexible portion having a projection 41 is provided. 2 can be adjusted in accordance with the initial molding variation and the variation due to deformation (in the present embodiment, the projections 41 are directed toward two of the four flexible portions 2 toward the flexible portions 2). Is provided).

Hereinafter, a seventh embodiment of the present invention will be described with reference to FIG. In the seventh embodiment, since the stopper 4 of the sixth embodiment has a function of adjusting the gap between the tip of the protrusion 41 and the suspension means 5, the semiconductor micro device according to the sixth embodiment is different. FIG. 7 showing the structure of the actuator is used again for the description of the seventh embodiment. Since the configuration of the stopper part 4 is the same as that of the sixth embodiment except for a part of the configuration, the description of the common part will be omitted.

The projecting portion 41 and the long hole portion 48 each have a male screw and a female screw (not shown) and are screwed together, and the gap is formed by turning the head of the projecting portion 41. By adjusting, the protrusion 41 can be brought close to the vicinity of the suspension means 5 or to a position where the suspension 41 contacts the suspension means 5 without being pressed. The protrusion 41 and the long hole 48 are not limited to such a screwing relationship,
What is necessary is just to have the function of adjusting the gap.

In this semiconductor microactuator, in addition to the effects of the sixth embodiment, the protrusion 41
The position can be easily adjusted according to the large variation of the flexible portion 2.

Hereinafter, an eighth embodiment of the present invention will be described with reference to FIG. In the eighth embodiment, the configuration of the protrusion 41 of the stopper portion of the first embodiment is changed. FIG. 8 shows a structure of a semiconductor microactuator according to an eighth embodiment of the present invention, where FIG. 8A is a sectional view and FIG. 8B is a top view. Projection 41 of stopper 4
Since the configuration other than the above is the same as that of the first embodiment, the description of the common parts is omitted.

The projection 41 has a tip 42 in contact with the movable part 1 and a projection base 41a other than the tip 42. The projection base 41a is made of glass, and the tip 42 is made of polyimide. The thermal conductivity of the polyimide is 1.17 × 10 ^-1 W / mK.

In this semiconductor microactuator, in addition to the effects of the first embodiment, the tip 42
The thermal conductivity of the movable part 1 or less,
Heat can be reduced from escaping from the movable portion 1 to the tip portion 42,
Low power consumption can be achieved. Further, when the material forming the tip portion 42 is polyimide, the formation of the protrusion 41 is easy. The present invention is not limited to the semiconductor microactuator of the above embodiment, and is not limited thereto. Various modifications are possible within the scope of the contents described in the paragraphs, and the present invention includes all of them.

In particular, although the embodiment relating to the bimetal structure has been described for the flexible portion 2, there is no particular problem as long as it can displace the movable portion 1, and the shape memory that changes its shape due to external factors such as heat is used. Of course, it may be made of a material or the like.

[0068]

As described above, in the semiconductor microactuator according to the first aspect of the present invention, at least the semiconductor substrate and the semiconductor microactuator which is bonded to the semiconductor substrate and displaces in a predetermined direction in accordance with a temperature change. One flexible portion, a movable portion suspended by the flexible portion and displaced in accordance with a change in the flexible portion, and at least one of the flexible portion and the movable portion is in a direction opposite to the predetermined direction. And at least one stopper portion for preventing the displacement in the opposite direction, and has the effect of reducing the power consumption required due to the displacement in the opposite direction.

Further, in the semiconductor microactuator according to the second aspect, in the invention according to the first aspect, the stopper has a projection, and the projection is provided toward the movable section. In the case where there is an initial molding defect in the movable portion, the defective portion is held down,
Further, when the movable portion is deformed by an external force, the deformation can be suppressed. Further, when an external force is excessively applied in the opposite direction, the movable portion or the damage can be prevented.

Further, in the semiconductor microactuator according to the third aspect, in the invention according to the first aspect, the stopper has a projection, and the projection is directed toward the flexible part. In this case, when there is an initial molding defect in the flexible portion, it is possible to suppress the defective portion. Further, there is an effect that the flexible portion can be temporarily prevented from being deformed in a convex shape in the direction opposite to the displacement direction of the movable portion immediately after the start of the deformation.

According to a fourth aspect of the present invention, in the semiconductor micro-actuator according to the third aspect, the stopper portion has a plate-like structure, and the stopper portion and the flexible portion are provided. Are arranged so as to overlap with each other, and the effect that the stopper portion can be easily formed is achieved.

According to a fifth aspect of the present invention, in the semiconductor micro-actuator according to the third aspect, the stopper portion adjusts an arrangement position in a direction substantially perpendicular to a displacement direction of the movable portion. In the case where a plurality of flexible portions are provided in one semiconductor microactuator, the initial molding variation of each of the flexible portions, and the variation corresponding to the variation due to deformation. This has the effect that the position of the stopper can be adjusted.

According to a sixth aspect of the present invention, in the semiconductor microactuator according to the second, third, or fifth aspect, the stopper is provided with respect to a displacement direction of the movable part. It has a function of adjusting the arrangement position in a substantially horizontal direction, and even when there is variation between products due to defective initial molding or the like, the distance between the stopper portion and the flexible portion or the movable portion can be reduced. The effect that adjustment is easy is produced. Further, even when a plurality of flexible portions are provided in one semiconductor microactuator, there is an effect that all the flexible portions can be pressed by the same amount.

According to a seventh aspect of the present invention, in the semiconductor microactuator according to the second, third, or sixth aspect, at least the flexible portion or the movable portion in the stopper portion. The protrusion has a thermal conductivity that prevents displacement of the flexible portion or the movable portion in the opposite direction by contact with the flexible portion or the movable portion at a position where the protrusion contacts. In this case, the heat dissipation is reduced by the heat insulation effect, so that the power consumption can be reduced.

Further, in the semiconductor microactuator according to the eighth aspect, in the invention according to the seventh aspect, the material forming the projection 41 is glass. 41 has an effect that a sufficient hardness can be secured, so that wear due to repeated use is small.

Further, in the semiconductor microactuator according to the ninth aspect, in the invention according to the seventh aspect, the material forming the tip end portion 42 of the projection 41 is polyimide. This has the effect that the projections 41 can be easily formed.

[Brief description of the drawings]

FIG. 1 is a sectional view and a top view of a semiconductor microactuator according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the power consumption of the semiconductor microactuator according to the first embodiment of the present invention and the displacement of the movable part.

FIG. 3 is a sectional view and a top view of a semiconductor microactuator according to a second embodiment of the present invention.

FIG. 4 is a sectional view and a top view of a semiconductor microactuator according to a third embodiment of the present invention.

FIG. 5 is a sectional view and a top view of a semiconductor microactuator according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view and a top view of a semiconductor microactuator according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view and a top view of a semiconductor microactuator according to sixth and seventh embodiments of the present invention.

FIG. 8 is a sectional view and a top view of a semiconductor microactuator according to an eighth embodiment of the present invention.

FIG. 9 is a sectional view, a top view, and a partially cutaway perspective view of a semiconductor microactuator according to a conventional example.

FIG. 10 is a sectional view showing a bimetal structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Movable part 2 Flexible part 3 Semiconductor substrate 4 Stopper part 5 Suspension means 6 Beam 7 Boss 8 Heating means 9 Inclined part 41 Projection part 42 Tip part 43 Support part 45 First support part 46 Second support part 47 Adjustment part 48 Length Hole

Claims (9)

[Claims] 1. A semiconductor substrate, at least one flexible portion joined to the semiconductor substrate and displaced in a direction determined in accordance with a temperature change, and suspended by the flexible portion in response to a change in the flexible portion. A movable portion that displaces the movable portion, and at least one stopper portion that prevents at least one of the flexible portion and the movable portion from displacing in a direction opposite to the predetermined direction. Semiconductor microactuator. 2. The semiconductor microactuator according to claim 1, wherein the stopper has a protrusion, and the protrusion is provided toward the movable portion. 3. The semiconductor microactuator according to claim 1, wherein the stopper has a protrusion, and the protrusion is provided toward the flexible portion. 4. The semiconductor microactuator according to claim 3, wherein the stopper has a plate-like structure, and the stopper and the flexible portion are arranged so as to overlap with each other. . 5. The semiconductor microactuator according to claim 3, wherein the stopper has a function of adjusting an arrangement position in a direction substantially perpendicular to a displacement direction of the movable part. 6. The stopper according to claim 2, wherein the stopper has a function of adjusting an arrangement position in a substantially horizontal direction with respect to a displacement direction of the movable part. A semiconductor microactuator according to item 1. 7. The thermal conductivity of the protruding portion in the stopper portion, which is in contact with at least the flexible portion or the movable portion and prevents displacement of the flexible portion or the movable portion in the opposite direction, 7. The semiconductor microactuator according to claim 2, wherein the thermal conductivity of the flexible portion or the movable portion at a position where the protrusion contacts is lower than the thermal conductivity of the flexible portion or the movable portion. 8. 8. The semiconductor microactuator according to claim 7, wherein a material forming the protrusion is glass. 9. A material forming a tip portion of the projection,
The semiconductor microactuator according to claim 7, wherein the semiconductor microactuator is polyimide.