JPH0556666A - Guide mechanism for actuator and its manufacture - Google Patents

Abstract

PURPOSE:To give a mobile electrode a desired action and simplify the manufacture process. CONSTITUTION:In an actuator which is equipped with a base 1, fixed electrodes 2a and 2b made on this base 1, and a mobile electrode provided between these fixed electrodes 2a and 2b, and in which the mobile electrode is free of shifting on the base 1 by applying voltage between the fixed electrodes 2a and 2b and the mobile electrode so as to make static power work, a plurality of recessed guide grooves 5 are made on the base 1, and projecting guide rails 6 engaging with the guide grooves 5 are made on the face on the side of the mobile electrode corresponding to these guide grooves 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator guide mechanism and a method for manufacturing the same.

[0002]

2. Description of the Related Art An example of the structure of a conventional actuator using electrostatic force will be described with reference to FIG. Here, a pantograph type structure will be described. Fixed electrodes 2a and 2b are provided on the base 1 at opposite positions on the left and right sides. A pantograph-type electrode 3 having a pantograph-type structure is disposed inside the fixed electrodes 2a and 2b, and the pantograph-type electrode 3 has four vertices a,
b, c, d are formed. In this case, the vertices a, c and the vertices b, d are formed at opposite positions, the vertices a, b, c are displaceable, and the apex d is fixed to the fixed end 4. Rod-shaped movable electrodes 3a and 3b are formed at the vertices a and c. A voltage V can be applied between the fixed end 4 and the fixed electrodes 2a and 2b.

In such a structure, the fixed electrode 2a,
2b and the fixed end 4 connected to the apex d of the pantograph-type electrode 3, a voltage V is applied between the movable electrodes 3a and 3b.
Are attracted to the left and right fixed electrodes 2a and 2b by electrostatic force, and the pantograph-type electrode 3 is deformed into a shape in which the rhombus is collapsed. Thereby, the vertex b can be displaced in the X direction inside thereof. Therefore, it becomes possible to draw out the force by connecting the vertex b to the outside.

[0004]

In the above-mentioned device, when the movable electrodes 3a, 3b are attracted to the fixed electrodes 2a, 2b side by electrostatic force, the electrostatic force acting as the attractive force is 2 times the distance. The movable electrode 3 has a characteristic inversely proportional to the power.
When the side edges of a and 3b come close to the fixed electrodes 2a and 2b, they are more strongly attracted, and as a result, the movable electrodes 3a and 3b are prone to unstable movement such as rotation. Such a phenomenon is caused by the displacement of the movable electrodes 3a, 3
This can be prevented by providing a guide mechanism in the area b. However, there is no example of providing such a guide mechanism by the conventional surface micromachining technique, which results in the unstable movement as described above.

[0005]

According to a first aspect of the present invention, a base, a fixed electrode formed on the base,
A movable electrode provided between the fixed electrodes is provided, and the movable electrode is made movable on the base by applying a voltage between the fixed electrode and the movable electrode to apply an electrostatic force. In the actuator, a plurality of concave guide grooves are formed on the base, and a convex guide rail engaging with the guide groove is formed on a surface of the movable electrode side corresponding to the guide grooves.

According to a second aspect of the present invention, there is provided a base, a fixed electrode formed on the base, and a movable electrode having a pantograph structure having four vertices provided between the fixed electrodes. An actuator in which the movable electrode is displaceable on the base by applying a voltage between the fixed electrode and the movable electrode to apply an electrostatic force, and corresponds to at least one apex of the movable electrode. Forming a concave guide groove on the base,
A convex guide rail engaging with the guide groove is formed on the apex side surface corresponding to the guide groove.

According to the third aspect of the present invention, the first sacrificial layer having a small film thickness is formed on the base, and the second sacrificial layer having a larger film thickness is formed on the first sacrificial layer. (2) By etching the surface of the sacrificial layer, a recess having a shape that engages with the guide rail is formed. After the movable member is deposited over the entire surface of the second sacrificial layer having the recess, the movable member is etched. The first sacrificial layer is formed in the shape of the movable electrode by performing the first sacrificial layer and is located below the recess of the second sacrificial layer when the second sacrificial layer is removed by an etching solution.
The sacrificial layer is also etched at the same time, so that the guide rail is formed on the movable electrode and at the same time, the first rail is formed.
A guide groove that engages with the guide rail is formed on the surface of the sacrificial layer.

[0008]

According to the present invention, the convex guide rail engaging with the guide groove is formed on the movable electrode side surface corresponding to the concave guide groove formed on the base. The movable part that moves due to electrostatic force does not move in a direction other than the direction of the guide groove or unstable movement due to rotation.

According to the third aspect of the invention, the guide rail and the guide groove that engages with the guide rail can be simultaneously manufactured in the same process.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. Here, an actuator having a pantograph type structure of a conventional example (see FIG. 7) will be described as an example. The same reference numerals are used for the same parts as those of the conventional example.

FIG. 1 (a) shows the area surrounded by broken lines at the vertices a, b and c in FIG. In this case, on the base 1 located below the vertices a, b and c of the pantograph type electrode 3, the vertices a and c are in the Y direction and the vertices b.
In, the two parallel concave guide grooves 5 are formed along the X direction (X and Y directions in FIG. 7). A convex guide rail 6 that engages with the guide groove 5 is formed on the surface of the pantograph-type electrode 3 on the apex a, b, c side corresponding to the guide groove 5.

In such a structure, the process of manufacturing the convex guide rail 6 formed on the surface of the pantograph type electrode 3 on the apex a, b, c side and the guide groove 5 formed on the base 1 will be described. 2 and FIG. 3 will be described. First, in FIG. 2, a c-Si substrate (crystal Si) 7
SiO ₂ 8 is deposited on the upper surface by ₂ μm (a). Next, etching is performed with HF to form 1 μm on the SiO ₂ 8.
A recess 9 having a depth of m is formed (b). Next, the recess 9
4μ of poly-Si 10 on the SiO ₂ 8 formed with
m Deposition (c). Next, the poly-Si 10 is etched into the shape of the pantograph-type structure 11 by RIE (reactive ion etching) (d).
Next, by removing SiO ₂ 8 with HF, the pantograph-type electrode 3 can be obtained, and at the same time, the convex guide rail 6 can be formed on the back surface side (e). Such guide rails 6 are formed at the vertices a, b and c of the pantograph type electrode 3.

Further, in FIG. 3, c- as a base is used.
Poly-Si 13 is deposited on the Si substrate 12 by 2 μm (a). Next, RI is applied to the poly-Si13.
A recess having a depth of 0.5 μm is formed by E (b). As a result, the guide groove 5 can be formed on the base 1.

Then, the guide groove 5 shown in FIG.
By placing the guide rail 6 of (e), it is possible to realize an actuator in which the pantograph-type electrode 3 moves only along the guide groove 5. Therefore, by providing the actuator with the guide mechanism including the guide rail 6 and the guide groove 5, the fixed electrodes 2a and 2b can be provided.
Even if a stronger electrostatic force is applied in the vicinity, the pantograph-type electrode 3 can be moved without deviating from the guide groove 5, and furthermore, unstable movement due to rotation or the like does not occur.

Next, a second embodiment of the present invention will be described with reference to FIGS. Here, an example in the case of being applicable to an actuator other than the pantograph structure as in the above-described first embodiment (see FIG. 1) is shown, and the basic configuration is almost the same, but as described below. It is characterized by a simple manufacturing process.

As shown in FIG. 4, two concave guide grooves 15 are formed on the base 14. A convex guide rail 17 that engages with the guide groove 15 is formed on the surface of the movable electrode 16 side that corresponds to the guide groove 15. Thereby, the guide rail 17 can move while being restrained by the guide groove 15 due to the electrostatic force.

With such a structure, the manufacturing process of this embodiment will be described with reference to FIG. First, Si ₃ N ₄ as the first sacrificial layer is formed on the c-Si substrate 18 as the base.
After depositing 19 of 0.5 μm, a second
SiO ₂ 20 as a sacrificial layer is deposited to a thickness of 2.0 μm (a). Then, the SiO ₂ 20 is etched by HF to form a recess 21 having a shape that engages with the guide rail 17 to a depth of 1.9 μm (b).
Next, a poly-Si 22 as a movable member is deposited from above on the entire surface including the recess 21 (c).
Next, the poly-Si 22 is etched by RIE to form the movable electrode 16 (d). Next, H
By completely removing the SiO ₂ 20 by F, a convex guide rail 17 can be obtained below the movable electrode 16 (e).

When the SiO ₂ 20 is etched by HF, the Si ₃ N ₄ 19 located below the guide rail 17 which is used for a long time in the HF etching solution is also etched by about 0.1 μm at the same time. _A recess 23 is formed in ₃ N ₄ 19 and this recess 23 becomes the guide groove 15 (f). By etching the SiO ₂ 20 in this way, the released movable electrode 16 falls to the substrate side below due to the bending of the support due to its gravity.
The 1.5 μm convex guide rail 17 is engaged with the guide groove 15, whereby a guide mechanism can be configured. Therefore, by using such a manufacturing process, the guide rail 17 and the guide groove 15 can be manufactured at the same time, and as a result, two separate manufacturing processes (see FIGS. Figure 3
Since it is not necessary to manufacture the semiconductor device by using the above method, it is possible to simplify the process.

Next, a third embodiment of the present invention will be described with reference to FIG. Here, the second embodiment described above (see FIG.
However, the description of the structure of the actuator is omitted.

On the c-Si substrate 24 as a base,
Poly-Si25 as the first sacrificial layer is deposited by 1 μm (a). Next, the poly-Si2
The surface of No. 5 was etched using RIE to a depth of 0.
A recess of 9 μm, that is, a guide groove 26 is formed (b).
Next, SiO ₂ 27 as a second sacrificial layer is deposited by ₂ μm over the entire surface where the guide groove 26 is formed (c). Next, poly-Si 28 as a movable member is deposited by 4 μm over the entire upper surface of the SiO ₂ 27 (d). Next, the poly-Si 28 is etched by RIE to form the movable electrode 29 (e). Next, HF etching is performed to remove all of the SiO ₂ 27, thereby forming the guide rail 30 below the movable electrode 29 (f). By this etching with HF, the released movable electrode 16 falls to the substrate side below due to the deflection of the support due to its gravity, and the convex guide rail 3
0 engages with the guide groove 26, whereby a guide mechanism can be configured (g). Therefore, also in the case of this embodiment, it is possible to simultaneously manufacture the guide rail 30 and the guide groove 26 in one manufacturing process as in the second embodiment described above, which simplifies the process. It is possible to plan.

[0021]

The invention according to claim 1 comprises a base, a fixed electrode formed on the base, and a movable electrode provided between the fixed electrode, and the fixed electrode and the movable electrode. In the actuator in which the movable electrode is movable on the base by applying a voltage between the electrodes to apply an electrostatic force, a plurality of concave guide grooves are formed on the base. Since a convex guide rail that engages with the guide groove is formed on the surface corresponding to the movable electrode side, the movable portion that is moved by electrostatic force is unstable due to movement in a direction other than the direction of the guide groove or rotation. The movement does not occur, so that it is possible to realize a guide mechanism having a stable driving force at all times.

According to a second aspect of the present invention, there is provided a base, a fixed electrode formed on the base, and a movable electrode having a pantograph type structure having four apexes provided between the fixed electrodes, An actuator in which the movable electrode is displaceable on the base by applying a voltage between the fixed electrode and the movable electrode to apply an electrostatic force, and corresponds to at least one apex of the movable electrode. A concave guide groove is formed on the base, and a convex guide rail that engages with the guide groove is formed on the apex-side surface corresponding to the guide groove.
The same effects as the described invention can be obtained.

According to a third aspect of the present invention, the first sacrificial layer having a small film thickness is formed on the base, and the second sacrificial layer having a larger film thickness is formed on the first sacrificial layer. (2) By etching the surface of the sacrificial layer, a recess having a shape that engages with the guide rail is formed. After the movable member is deposited over the entire surface of the second sacrificial layer having the recess, the movable member is etched. By doing so, when the second sacrificial layer is formed into the shape of the movable electrode, the first sacrificial layer located below the recess of the second sacrificial layer is also etched at the same time when the second sacrificial layer is removed by an etching solution. Since the guide rail is formed on the movable electrode and the guide groove engaging with the guide rail is formed on the surface of the first sacrificial layer, the guide rail and the guide groove engaging with the guide rail are the same. It is possible to produce simultaneously at process, thereby is capable of achieving process simplification further.

[Brief description of drawings]

FIG. 1A is a plan view showing a state of a guide mechanism formed in a region of one apex of a pantograph type electrode according to a first embodiment of the present invention, and FIG. 1B is a sectional view taken along the line AA. is there.

FIG. 2 is a process drawing showing a manufacturing process of a guide rail formed on the movable electrode side.

FIG. 3 is a process drawing showing a process of manufacturing a guide groove formed on the base on the fixed electrode side.

FIG. 4A is a plan view showing a second embodiment of the present invention,
(B) is the AA sectional view.

FIG. 5 is a process drawing showing a process by which a guide rail and a guide groove can be simultaneously manufactured.

FIG. 6 is a process drawing showing a third embodiment of the present invention.

FIG. 7 is a configuration diagram showing a state of an actuator having a pantograph type structure which is a conventional example.

[Explanation of symbols]

 1 Base 2a, 2b Fixed electrode 3a, 3b Movable electrode 5 Guide groove 6 Guide rail 15 Guide groove 16 Movable electrode 17 Guide rail 19 First sacrificial layer 20 Second sacrificial layer 22 Movable member 25 First sacrificial layer 26 Guide groove 27th 2 Sacrificial layer 28 Movable member 29 Movable electrode 30 Guide rail

Claims (3)

[Claims] 1. A base, a fixed electrode formed on the base, and a movable electrode provided between the fixed electrodes, wherein a voltage is applied between the fixed electrode and the movable electrode to maintain static electricity. In the actuator in which the movable electrode is movable on the base by applying electric power, a plurality of concave guide grooves are formed on the base, and the movable electrode side corresponding to the guide groove is formed. A guide mechanism for an actuator, characterized in that a convex guide rail that engages with the guide groove is formed on the surface. 2. A fixed electrode formed on the base, a fixed electrode formed on the base, and a movable electrode having a pantograph structure having four apexes provided between the fixed electrodes, the fixed electrode and the movable electrode. In an actuator in which the movable electrode is displaceable on the base by applying a voltage between the movable electrode and the electrode, a concave shape is formed on the base corresponding to at least one apex of the movable electrode. The guide mechanism of the actuator, wherein the guide groove is formed, and a convex guide rail that engages with the guide groove is formed on the apex side surface corresponding to the guide groove. 3. A first sacrificial layer having a small film thickness is formed on a base, and a second sacrificial layer having a larger film thickness is formed on the first sacrificial layer. A recess having a shape that engages with the guide rail is formed by etching, the movable member is deposited over the entire surface of the second sacrificial layer having the recess, and then the movable member is etched to remove the movable electrode. When the second sacrificial layer is formed into a shape, the first sacrificial layer located below the recess of the second sacrificial layer is etched at the same time when the second sacrificial layer is removed by an etching solution, whereby the guide is provided to the movable electrode. A method of manufacturing a guide mechanism for an actuator, characterized in that a guide groove that engages with the guide rail is formed on the surface of the first sacrificial layer at the same time when the rail is formed.