JP2002321198A - Micro structural body, micromechanical sensor, microactuator, microoptical polariscope, optical scanning display and manufacruring method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro structural body with high elasticity in vertical direction for twist axis while maintaining sufficient compliance in twist direction. SOLUTION: The micro structural body has a substrate 120 and at least an oscillating element 130. The oscillating element 130 is elastically and oscillation freely supported by at least a pair of torsion springs 128 and 129 comprising a plurality of torsion bars 122-125 for the substrate 120. The pair of torsion springs 128 and 129 includes at least two torsion bars 122-125 which are so placed that the long axis are parallel and close to each other, and the bars have the cross sectional shape of the face vertical to the long axis being flat and so placed that the direction most easily twist may cross.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the field of micromachines or microstructures. More specifically, the present invention relates to a micro mechanical quantity sensor, a micro actuator, a micro optical deflector, and the like having a member that swings around a torsion center axis.

[0002]

2. Description of the Related Art It is well known that when an attempt is made to reduce the size of a mechanical element, the ratio of surface force becomes larger than that of body force, and the influence of friction becomes larger than that of a machine having a normal size. For this reason, in designing a micromachine, it is common to consider to minimize the sliding portion and the rotating portion.

Here, a conventional example of an optical deflector having a member that swings around an axis will be described. FIG. 23 shows U.S. Pat.
1 shows a perspective view of an optical deflector disclosed in the specification of Japanese Patent No. 17611. FIG. 24 is a view for explaining the internal structure.
It is the figure which disassembled and displayed the said optical deflector. FIG.
5 and FIG. 26 correspond to cutting lines 1003 and 1 in FIG.
006 shows a cross-sectional view of the silicon thin plate 1020.

In the above optical deflector, a recess 1012 is formed in a substrate 1010 made of an insulating material. A pair of drive electrodes 101 is provided at the bottom of the recess 1012.
4, 1016 and a mirror support 1032 are arranged. The silicon thin plate 1020 has a torsion bar 10
22, 1024 and the mirror 1030 are integrally formed. The mirror 1030 has a surface coated with a substance having high light reflectance, and has a torsion bar 1022,
024 for free swinging. The silicon thin plate 1020 is disposed on the substrate 1010 so as to keep a predetermined distance from the drive electrodes 1014 and 1016.

[0005] Here, the silicon thin plate 1020 is
It is electrically grounded. Therefore, the drive electrode 1014,
By alternately applying a voltage to 1016, the mirror 103
The mirror 1030 is swung around the major axis of the torsion bar 1022, 1024 by applying an electrostatic attraction to zero.

The sectional shape of the torsion bars 1022, 1024 is trapezoidal as shown in FIG. However, such a microstructure having a torsion bar having such a cross-sectional shape has a problem in that the torsion bar is easily bent, so that external vibration is picked up or the axis of the torsion bar is shaken, so that accurate driving cannot be performed. was there.

Therefore, when such an optical deflector is applied to an optical scanning display, there is a problem that an image is blurred or a spot shape is changed by external vibration. This becomes a greater problem when the optical scanning display is made in a portable form.

In order to make the torsion bar hard to bend, the following structure has been proposed. FIG.
10th International Conference on Solid-State Senso
rs and Actuators (Transducers '99) A gimbal for a hard disk head disclosed in pp. 1002-1005.
The gimbal is attached to the tip of the suspension for the hard disk head, and allows the magnetic head to elastically allow the roll and pitch to move. The gimbal 2020 has a roll torsion bar 2022 inside,
A support frame 2031 that is rotatably supported at 2024 is provided. A head support 2030 rotatably supported by pitch torsion bars 2026 and 2028 is formed inside the support frame 2031. Roll torsion bar 2022, 2024 and pitch torsion bar 2
The torsional axes of 026 and 2028 (see the orthogonal chain lines in FIG. 27) are orthogonal to each other, and are responsible for the roll and pitch movement of the head support 2030, respectively.

FIG. 28 is a cross-sectional view taken along section line 2006 in FIG. As shown in FIG. 28, the torsion bar 2022 has a T-shaped cross section, and the gimbal 2020 has a structure having ribs.

The manufacturing process of the gimbal will be described with reference to FIG. First, a silicon wafer 2091 for molding is used.
Next, vertical etching is performed using an etching method such as ICP-RIE (inductively coupled plasma-reactive ion etching) (a). This molding silicon wafer 2091
Can be reused. Next, a sacrifice layer 2092 made of a silicon oxide film and phosphoric glass is formed on the silicon wafer 2091 for molding (b). Subsequently, a polysilicon layer 2093 to be a structure is formed (c).
Then, the polysilicon layer 2093 is patterned (d). Finally, the sacrificial layer 2092 is removed, and the polysilicon layer 2093 is bonded to the patterned pad 2095 with the epoxy resin 2094 (e).

The torsion bar having a T-shaped cross section manufactured as described above has a smaller secondary moment of area J than a torsion bar having a cross-sectional shape such as a circular cross section or a rectangular cross section. There is a feature that the moment I is large. Therefore, it is possible to provide a torsion bar that does not easily bend, although it is relatively easy to twist. That is,
While ensuring sufficient compliance in the torsional direction,
A rigid torsion bar can be provided in the direction perpendicular to the axis of twist.

Further, since a torsion bar having a short length for obtaining necessary compliance and an allowable torsion angle can be provided, there is an advantage that the size can be further reduced.

Thus, by using the torsion bar having the T-shaped cross section, a micro gimbal which has sufficient compliance in the roll and pitch directions, has sufficient rigidity in other directions, and can be made more compact. Can be provided.

[0014]

However, this microstructure has the following problems. 1. The torsion bar having a T-shaped cross section is fragile when twisted because stress concentration occurs at a portion 2050 in FIG. 2. In a torsion bar having a T-shaped cross section, the center of the torsion does not coincide with the center of the center of gravity axis. Therefore, an exciting force in a direction perpendicular to the axis of the torsion is generated at the time of swinging.
Therefore, unnecessary movement occurs during driving. 3. Since the internal loss of polysilicon is larger than that of single crystal silicon, the mechanical Q value is reduced. Therefore, when driving utilizing mechanical resonance, the vibration amplitude cannot be increased. In addition, energy efficiency is low due to large loss.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and to provide a micro-mechanical sensor or micro-actuator having a member swinging about an axis, a micro-actuator, a micro-machine or a micro-structure which can be applied to a micro optical deflector and the like. It is to provide a manufacturing method.

[0016]

A microstructure according to the present invention for solving the above problems has a substrate and at least one or more oscillating body, and the oscillating body comprises a plurality of torsion bars. In a microstructure that is elastically and freely swingably supported on the substrate by more than one set of torsion springs, one set of torsion springs is arranged in parallel and close to each other so that their long axes are parallel to each other. The cross section of the plane perpendicular to the major axis is flat, and includes at least two torsion bars arranged so that the directions in which the bending is most likely to intersect.

If a plurality of torsion bars are arranged in parallel and close to each other so that their major axes are parallel to each other, they will reinforce each other against bending in the direction perpendicular to the axis of torsion. Is less likely to occur. Further, since the torsion spring is constituted by a plurality of torsion bars, the cross-sectional shape of each torsion bar can be made relatively simple (typically, a simple flat shape), and a portion where stress concentration occurs is less likely to be generated. It becomes hard to break.

Further, since the plurality of torsion bars constituting a set of torsion springs include at least two torsion bars arranged so that the directions in which they are most likely to intersect each other, the torsion bars in the direction perpendicular to the axis of torsion can be formed. Since the members mutually reinforce each other more effectively against the deflection, the excitation force in this direction is less likely to be generated.

After all, according to the structure of the present invention, at least two torsion bars are arranged in parallel so that a plurality of torsion bars constituting a set of torsion springs are flat in cross-section and intersect in the direction in which they are most flexible. Including bars.

Based on the above basic configuration, the following more specific forms are possible. The plurality of torsion bars constituting a set of torsion springs are arranged so that when cut along a cross section perpendicular to the long axis, the cross-sectional shape is symmetric (see FIG. 4). Are arranged so as to be vertically and horizontally symmetrical (see FIGS. 11 and 17). However, if necessary, an inverted C-shaped or torsion-shaped torsion spring having an asymmetrical cross-sectional shape, a cross-shaped or H-shaped torsion spring having an asymmetrical vertical or horizontal cross-sectional shape may be used. .

Typically, the material of the torsion bar is a single crystal material such as silicon single crystal or quartz. Further, the substrate, the oscillator, and the torsion spring can be integrally formed by etching or the like from a single crystal material substrate such as a common silicon single crystal or quartz.

Further, a (100) silicon substrate is used, and a torsion spring is formed by anisotropic etching of the (100) silicon substrate so that an inclined surface of the (100) substrate surface which defines the outer surface thereof is (111). ) Surface. At this time, an outer surface of a base of a torsion spring connected to the substrate or the oscillator is defined (100).
The surface with respect to the substrate surface can also be the (111) plane.
Since the (111) plane is formed with high precision and smoothness, the produced torsion spring is difficult to break. Furthermore, if the surface of the root portion of the torsion spring is also a (111) slope, stress concentration there can be reduced, and the reliability of the torsion spring can be increased.

Further, a flat substrate made of silicon or the like is used, and a torsion spring is used for the ICP-RIE of the flat substrate.
It is also possible to form the surface defining the outer surface from the flat substrate surface and a surface perpendicular or parallel to the surface by the deep etching using the method described above.

The cross-sectional shape of the torsion spring has a shape such as an inverted C shape, a C shape, a cross shape, and an H shape.

The corners of the torsion spring may be lightly rounded by isotropic etching to reduce stress concentration there.

The cross-sectional shapes of the two or more sets of torsion springs supporting the oscillator may be different from each other with respect to the torsion springs opposed to each other across the oscillator. Thereby, it is possible to provide a structure that is less likely to bend in the direction perpendicular to the axis of the torsion while sufficiently maintaining the compliance of the torsion. That is, in this structure, the directions in which the torsion springs that oppose each other with the oscillator interposed therebetween are easy to bend. Therefore, the oscillation or displacement of the oscillator in this direction, which is unnecessary in a micro structure such as a micro optical deflector, Can be reduced.

More typically, the cross-sectional shapes of the torsion springs that face each other with the rocking member interposed therebetween can be arranged symmetrically with respect to a plane including the torsion center axis of the opposing torsion springs. A typical example of this is that the oscillating body is a flat oscillating plate (in a micro-optical deflector, a reflection surface is usually formed on this flat portion), and a torsion spring opposed to the oscillating plate is used. The cross-sectional shape is to be arranged symmetrically with respect to a plane including the torsion center axis of the opposing torsion spring and parallel to the rocking plate. Thereby, the directions in which the torsion springs easily bend can be symmetrically crossed. Therefore, it is possible to have a structure that is difficult to bend effectively in the direction perpendicular to the axis of the torsion, which is a preferable form of the above basic configuration.

As the form of the microstructure, the above-mentioned oscillating body is one, and one or two oscillating bodies extend substantially along a straight line.
It is possible to adopt a form in which the rocking body is elastically supported by the set of torsion springs about the straight line with respect to the substrate. The form of the two sets of torsion springs is described in the embodiment described later. However, if the rocking body is sufficiently lightweight and can be freely and freely supported by the set of torsion springs, such a form may also be used depending on the application. Can be used.

As another form of the microstructure, there are a plurality of the rocking bodies, the plurality of rocking bodies are arranged in a nested manner, and each rocking body is composed of two sets of torsion extending substantially along each straight line. A form in which the spring is elastically supported by the spring on the outer swinging body or the substrate so as to freely swing around each of the straight lines may be employed. An example in which two oscillators are nested is shown in FIG. If necessary, a form in which three or more rockers are nested can be realized. The angle formed by the straight lines is typically 90 degrees (see the example in FIG. 27), but may be an angle other than 90 degrees if necessary.

As still another form of the microstructure, there are a plurality of the oscillators, the plurality of oscillators are arranged in series with a torsion spring interposed, and the outermost oscillator is attached to the substrate. A form supported by a torsion spring may be employed. For example, a relatively small mass oscillator is sandwiched between relatively large mass oscillators with a torsion spring interposed, and the large mass oscillators on both sides are connected to a substrate with a torsion spring interposed, and these three torsion springs are connected. As a form extending substantially along a straight line, in this form, a large-mass oscillator is driven indirectly by driving a large-mass oscillator. In any case, in the microstructure of the present invention, a pair of torsion springs are arranged in parallel and close to each other so that their major axes are parallel to each other, and the cross-sectional shape of a plane perpendicular to the major axis is flat. It is characterized by including at least two torsion bars arranged so that the directions in which they are most likely to intersect, and the form may be various depending on the application.

Further, a micro mechanical quantity sensor according to the present invention for solving the above-mentioned problems comprises the above-mentioned micro structure,
It is characterized by having a displacement detecting means for detecting a relative displacement between the substrate and the oscillator. As the displacement detecting means, a conventionally known means can be used. For example, there is a means for detecting a relative change between the substrate and the oscillating body by detecting a change in capacitance by a voltage change. Specific examples thereof include JP-A-8-145717,
JP-A-2000-65664, JP-A-2000-29243
No. 4 and the like.

Furthermore, a microactuator according to the present invention for solving the above-mentioned problems is characterized in that the microactuator has the above-mentioned microstructure and driving means for driving the oscillator relatively to the substrate. . As the driving means, a fixed core, a coil orbiting the fixed core (made of a soft magnetic material), and a movable core (a soft magnetic or hard magnetic permanent magnet) joined to the oscillating body are used. In the former, the magnetic pole of the soft magnetic material is not fixed, and when the magnetic flux is generated in the fixed core, the direction of the cross-sectional area of the soft magnetic material that increases the magnetic flux of the magnetic circuit increases. A driving force is generated to attract the soft magnetic material into the magnetic flux,
When the magnetic flux disappears, it is released from it, whereas in the latter, the magnetic pole of the hard magnetic material is fixed, and a magnetic force (attraction or repulsion) between different or same magnetic poles is a driving force). Or use electrostatic attraction.

Further, a micro optical deflector according to the present invention for solving the above problems is provided with the micro structure, a driving means for driving the oscillating body relatively to the substrate, and a oscillating body. It is characterized by having a light reflecting means provided. The driving means is as described above. The light reflecting means includes a light reflecting surface or a diffraction grating. In the latter, one beam can be deflected as a plurality of beams (diffraction light).

Further, an optical scanning type display according to the present invention for solving the above-mentioned problems comprises a micro-optical deflector, a light source capable of modulation (such as a semiconductor laser), the modulation of the light source and the micro-optical deflection. It has a control means for controlling the operation of the rocking body of the vessel.

Further, a method for manufacturing a microstructure according to the present invention for solving the above-mentioned problems includes a step of forming a mask layer on both sides of a (100) silicon substrate, And a step of patterning according to the form of the torsion spring, and a step of anisotropically etching the (100) silicon substrate using an alkaline solution or the like.

Further, another method of manufacturing the microstructure according to the present invention for solving the above-mentioned problems includes a step of forming mask layers on both surfaces of a material substrate such as a silicon substrate, and a method of forming the mask layers on both surfaces. A step of patterning according to the form of the oscillator and the torsion spring, a step of deeply etching the material substrate from one side using ICP-RIE, and a step of etching the material substrate from the other side using ICP-RIE or the like. It is characterized by including a deep etching step.

In the method of manufacturing these microstructures, the corners of the torsion spring may be lightly isotropically etched to round it, thereby reducing stress concentration there.

[0038]

The operation of the microstructure of the present invention will be described. FIG. 21 illustrates a case where the cross-sectional shape is an ellipse, as an example of a torsion bar having a flat cross-sectional shape. The torsion bar having an elliptical cross section as shown in FIG. 21 is most likely to bend in the direction of the minor axis of the ellipse (minimum secondary moment of area), and is least likely to bend in the direction of the minor axis of the ellipse (minimum secondary moment of area). ). Generally, there are two directions in which the second moment of area takes an extreme value, and it is known that these directions are orthogonal to each other.

In the microstructure of the present invention, a structure that is hardly bent is realized by combining a plurality of torsion bars having a relatively simple shape with a flat cross section so that the directions in which the most easily bendable intersect. ing.

In the microstructure of the present invention, since a plurality of torsion bars having a simple shape are used, T
Since a point where stress concentration occurs unlike a torsion bar having a V-shaped cross section is less likely to occur, it is more difficult to break when a torsion spring having the same torsion spring constant and the same length is considered. Also, considering the same allowable torsion angle, a shorter torsion spring can be realized as compared with a torsion bar having a T-shaped cross section.

In the microstructure of the present invention,
Combining a torsion bar with a flat cross-section so that the cross-section becomes symmetrical in the vertical and horizontal directions allows the center of the torsion axis to easily match the center of gravity of the torsion spring. Excitation forces in the direction perpendicular to the axis of torsion can be prevented from occurring more effectively.

Further, in the microstructure of the present invention,
When a single crystal material is used for the material, the single crystal material has a smaller internal loss than polysilicon, so that the mechanical Q value can be increased. Therefore, when using mechanical resonance, the vibration amplitude can be increased, and the energy efficiency is increased. As the single crystal material, it is preferable to use single crystal silicon that is easily available and has excellent mechanical properties (that is, it is relatively lightweight but has excellent physical strength, durability, and life).

[0043]

Embodiments of the present invention will be described below with reference to the drawings to clarify the embodiments of the present invention.

Embodiment 1 FIG. 1 is a perspective view for explaining a micro optical deflector according to Embodiment 1 of the present invention. FIG.
FIG. 2 is an exploded view of the micro optical deflector for describing an internal structure. FIG. 3 is a sectional view for explaining the operation of the micro optical deflector of the present embodiment. FIG.
FIG. 2 is a cross-sectional view of the silicon single crystal thin plate 120 taken along a cutting line 106 in FIG. 1 for explaining the structure of the torsion spring which is a feature of the present embodiment.

In the micro optical deflector of the first embodiment, a concave portion 112 is formed in a glass substrate 110.
A pair of drive electrodes 114 and 11 are provided at the bottom of the recess 112.
6 and a triangular prism-shaped mirror support 132 are arranged. The mirror support 132 is provided to realize more stable swing, but this can be omitted. The silicon single crystal thin plate 120 is provided with the torsion springs 128 and 129 and the mirror 1 by bulk micromachining technology.
30 are integrally formed. As shown in FIG. 4, the torsion springs 128, 129, which are the features of this embodiment, are formed by grouping two flat torsion bars 122, 123; 124, 125 as shown in FIG. It is composed of

The mirror 130 is formed by coating a material having a high light reflectance on the surface of a flat plate, and is supported by torsion springs 128 and 129 so as to swing freely. The silicon single crystal thin plate 120 is disposed on the glass substrate 110 so that the mirror 130 keeps a predetermined distance from the drive electrodes 114 and 116. The lower surface of the mirror 130 along the torsion axis of the torsion springs 128, 129 is in contact with the top line of the mirror support 132, and the mirror 130 rotates around the pivot axis along the top line.
Can be swung.

The silicon single crystal thin plate 120 is electrically grounded. Therefore, by alternately applying a voltage to the drive electrodes 114 and 116, an electrostatic attraction is applied to the mirror 130, and the mirror 130 can be swung around the swing axis. The driving force is not limited to the electrostatic attractive force, but may be a magnetic force or the like. In this case, a configuration is adopted in which an electromagnet is provided instead of the drive electrode and a permanent magnet made of a hard magnetic material is fixed to the lower surface of the mirror 130.

The method of manufacturing the above optical deflector will be described in detail below with reference to FIGS. 6 (a) to 6 (e)
Represents a cross section taken along a cutting line 106 in FIG. 1, and FIG.
(E) shows a cross section taken along the cutting line 109 in FIG.

First, as shown in FIG.
The processing of No. 20 will be described. 1. The mask layer 15 is formed on both sides of the silicon single crystal thin plate 120.
0 (for example, SiO ₂ or silicon nitride produced by low-pressure chemical vapor deposition). As the silicon single crystal thin plate 120, a (100) substrate is used. Then, the mask layer 150 is patterned by photolithography (a). This mask pattern is the portion of the torsion spring 128 and 129, a stripe-shaped opening of each of the substrate 120 upper and lower side width W _a width W _b are formed. Striped opening of width W _b is formed as a pair across a stripe-shaped mask layer 150, the stripe-shaped opening having a width W _a is formed one on top location corresponding to the stripe-shaped mask layer. Width W _a is of two torsion bars 1
22,123; 124,125 is set to the interval of the top, the width _{W b} of the width of the stripe-shaped mask layer 150 between the two openings of two torsion bars 122 and 123; 1
24 and 125 are set at the lowest interval. In this mask pattern, an opening having an appropriate width is also formed on the upper surface of the substrate 120 along the outer shape of the mirror 130.

2. Using an anisotropic etching solution which is an alkaline solution such as KOH, a silicon single crystal thin plate 120 is used.
Etching is performed from both sides. Since the anisotropic etching of silicon proceeds quickly on the (100) plane and proceeds slowly on the (111) plane, the etching first proceeds such that the opening becomes narrower as the hole is dug (b, c).

3. The etching proceeds until it penetrates the substrate 120 from both sides, and stops at the mask layer 150 (d). As shown in FIG. 5, since the (111) plane of silicon has an angle of 54.7 degrees with respect to the (100) plane, the relationship between the width w of the opening and the depth d of the V groove is d = w / 2 ・ ta
n54.7 °. Therefore, in order to penetrate the substrate 120, it is necessary to satisfy the W _a, the relationship W _b> 2t / tan54.7 °. Here, t is the thickness of the silicon single crystal thin plate 120.

At this time, since the (111) plane is formed with high precision and smoothness, the produced torsion springs 128 and 129 having the inverted C-shaped cross section are hard to be broken. Further, by the anisotropic etching, the surface of the V-groove at the root of the torsion springs 128 and 129 (FIG. 2)
2A (shown by 128a and 129a in FIG. 2A) (FIG. 2B).
20 (a cross-sectional view of FIG. 20), the (111) slope is formed, so that stress concentration can be reduced, the reliability of the torsion spring can be increased, and the light deflection angle of the mirror can be increased.

4. After the anisotropic etching, isotropic etching may be performed with a gas or an acid to round the corners of the torsion spring. In this way, stress concentration on these portions can be reduced.

5. Next, the mask layer 150 is removed (e). 6. Finally, the mirror 130 is washed, and a light reflection film is formed on the surface.

Next, a method of processing the glass substrate 110 will be described with reference to FIG. 1. A mask layer 151 (resist or the like) is formed on both surfaces of the glass substrate 110 (a).

2. The mask layer 151 is patterned (b). Triangular prism shaped mirror support 132 and recess 112
Is patterned so as to be formed by etching. 3. Etching is performed so that the depth of the concave portion 112 becomes 25 μm (c). At this time, a mirror support 132 having a triangular prism shape is formed.

4. The mask layer 151 is removed, and the recess 11 is removed.
2, drive electrodes 114 and 116 having a predetermined pattern are formed (d). 5. The silicon single crystal thin plate 120 and the glass substrate 110 are joined so as to form a micro optical deflector as shown in FIG. 1 (e).

As described above, according to the manufacturing method of this embodiment, the torsion bars 122, 123; 124, and 125 having flat cross sections are combined in an inverted C shape by performing the anisotropic etching only once. Torsion spring 12
8, 129 can be manufactured.

As shown in FIG. 4, in the torsion spring 128 (129) of the optical deflector of this embodiment, 2
Book flat torsion bars 122 (124) and 123 (1
25) are arranged at an angle of 70.6 ° to each other. That is, since the directions in which the flat torsion bar is most likely to be bent (low bending rigidity) are combined so as not to be parallel, the torsion spring as a whole has a structure with high bending rigidity.

According to the present embodiment, unlike the torsion bar having a T-shaped cross section, a large stress concentration does not occur. Therefore, when a torsion spring having the same torsion spring constant and the same length is considered, the microstructure is more difficult to break. Can be realized. Further, according to the present embodiment, a microstructure that can be further reduced in size as compared with a torsion bar having a T-shaped cross section can be realized when considering the same allowable torsion angle. Further, by using single crystal silicon as a material, a microstructure having a larger mechanical Q value than polysilicon can be realized.

According to this embodiment, it is possible to realize a micro optical deflector that is harder to break, can be made smaller, and has a large vibration amplitude when driven by resonance. Further, by using the manufacturing method of this embodiment, the microstructure of the present invention can be manufactured relatively easily.

A modification of the first embodiment will be described with reference to FIG. FIG. 8 is a perspective view (a) and a sectional view (b) for explaining a micro optical deflector according to a modification of the first embodiment of the present invention. In this modification, the torsion bar has a flat cross section surrounded by the substrate surface and the (111) plane of silicon, and the two torsion springs 528 and 529 are combined in an inverted C shape and a C shape. ing. The side surfaces of the reflection surface 530 and the frame 520 have a shape in which the (111) plane of silicon is exposed. However, in FIG. 8, for simplicity, the side surfaces are drawn perpendicular to the reflection surface 530. This is the same in other drawings.

The micro optical deflector of this modification is similar to that of FIG.
As shown in (b), the shape of the cross section AA ′ and the shape of the cross section BB ′ of the torsion bar are parallel to the substrate surface (more precisely, the torsion center axis of the opposing torsion spring). (A plane parallel to the reflecting surface 530). Thereby, at the time of torsional resonance driving, unnecessary motion modes such as flexural vibration generated due to one torsion bar structure and the influence of disturbance can be canceled by the other torsion bar structure, and drive stability is improved. be able to.

In the micro optical deflector according to this modification, similar to the first embodiment (only the pattern of the mask layer 150 in FIG. 6 is changed (upside down) for the other torsion bar structure). By performing the isotropic etching only once, the torsion springs 528 and 529 combining the torsion bars having a flat cross section can be easily manufactured.

In this modification, the process is easy, and the cross-sectional shapes of the two torsion springs are different from each other, thereby canceling out the influence of disturbance at the time of driving caused by the respective torsion springs as described above. It is possible to provide a micro optical deflector having a structure in which the torsion bar has no stress concentration portion and is hardly broken.

[Embodiment 2] FIG. 9 is a perspective view illustrating an acceleration sensor according to Embodiment 2 of the present invention. FIG.
0 is an exploded view of the acceleration sensor for describing the internal structure. FIG. 11 is a cross-sectional view of the silicon thin plate 220 taken along a cutting line 206 in FIG.

In the acceleration sensor of this embodiment, a concave portion 212 is formed in the insulating substrate 210. A detection electrode 216 is arranged at the bottom of the recess 212.
A pair of torsion springs 228 and 229 and a movable member 230 are integrally formed on the silicon thin plate 220. The torsion spring 22 which is a feature of this embodiment
8, 229 are flat torsion bars 221 to 221 respectively.
As shown in FIG. 11, 223, 224 to 226 are arranged in a combination of three pieces in an H shape. As can be seen from FIG. 11, the torsion springs 228 and 229 are configured such that the directions in which the bending stiffness of the flat torsion bar is low are not all parallel, and are symmetrical in the vertical and horizontal directions. .

The movable member 230 is swingably supported by its torsion springs 228 and 229 around its long axis. The silicon single crystal thin plate 220 is placed on the insulating substrate 21 so as to keep a predetermined distance from the detection electrode 216.
0 and are electrically grounded.

In the above configuration, when acceleration acts on the silicon single crystal thin plate 220 in a direction perpendicular thereto, inertial force acts on the movable member 230, and the movable member 230 moves around the major axis of the torsion springs 228, 229. Rotational displacement. When the movable member 230 is rotationally displaced, the detection electrode 2
Since the distance between the movable member 230 and the detection electrode 216 changes, the capacitance between the movable member 230 and the detection electrode 216 changes. Therefore, the acceleration can be detected by detecting the capacitance between the detection electrode 216 and the silicon single crystal thin plate 220 by a conventionally known means.

Conversely, when a voltage is applied to the detection electrode 216, an electrostatic attraction acts between the movable member 230 and the detection electrode 216, and the movable member 230
8,229 swing around the long axis. That is, the acceleration sensor according to the present embodiment can also be used as an electrostatic actuator.

FIG. 1 shows a method of manufacturing the acceleration sensor.
2 and FIG. 13 will be described in detail below. FIG.
(A) to (e) show a section taken along the cutting line 206 in FIG. 8, and FIGS. 13 (a) to (e) show sections taken along the cutting line 209 in FIG.

First, a method of processing a single-crystal silicon thin plate 220 (this plane orientation does not matter) will be described with reference to FIG. 1. A mask layer 250 (for example, a resist or the like) is formed on both surfaces of the silicon thin plate 220, and patterning is performed by photolithography so that the silicon thin plate 220 having the form shown in FIG. 10 can be formed by etching (a).

2. Using a deep etching method such as ICP-RIE, H-shaped torsion springs 228,
Vertical etching is performed on the torsion bar 29, the movable member 230, and the silicon thin plate portion other than the frame portion to a certain depth from both surfaces (b). This depth defines the thickness of the torsion bars 222 and 225 of the separated horizontal bar portions having an H-shaped cross section (approximately twice this depth is the thickness of the horizontal bar portions). Vertical torsion bars 221, 223; 22
4 and 224 are defined by the width of a pair of relatively narrow stripe portions on both sides of the relatively wide central stripe portion of the mask layer 250.

3. After removing the mask layer 250, a new mask layer 251 is formed and patterned (c). At this time, unlike the patterning of the mask layer 250, the mask layer 251 is not formed on the horizontal bar portions of the torsion springs 228 and 229. 4. Again, vertical etching is performed using an etching method such as ICP-RIE. First, etching is performed from the lower surface in the figure. The process is performed until the depth of the place dug in the step reaches the center of the thickness of the silicon thin plate 220 (c).

5. This time, 2. The vertical etching is performed from the upper surface in the figure until the place dug in the above penetrates the silicon thin plate 220 (d). 6. Finally, the mask layer 251 is removed (e).

Next, a method of processing the insulating substrate 210 will be described with reference to FIG. 1. A mask layer 252 (resist or the like) is formed on both surfaces of the insulating substrate 210 (a).

2. The mask layer 252 is formed so that the insulating substrate 210 having the form shown in FIG. 10 can be formed by etching.
Is patterned (b). 3. Etching is performed so that the depth of the concave portion 212 becomes 15 μm to form the concave portion 212 (c).

4. The mask layer 252 is removed, and the recess 21 is removed.
Then, a detection electrode 216 is formed on the substrate 2 by vapor deposition or the like (d). 5. The silicon thin plate 220 and the glass substrate 210 are joined so as to form an acceleration sensor as shown in FIG. 9 (e).

In the torsion springs 228 and 229 in which the flat torsion bar as shown in FIG. 11 is combined so as to have an H-shaped cross section, the direction in which the bending rigidity of the flat torsion bar is low is a feature of this embodiment. Since they are all assembled so as not to be parallel, the bending rigidity is high as a whole.

Further, according to the present embodiment, unlike the torsion bar having a T-shaped cross section, no large stress concentration occurs.
When a torsion spring having the same torsion spring constant and the same length is considered, a microstructure that is more difficult to break can be realized. Also, considering the same allowable torsion angle, it is possible to realize a microstructure smaller than a torsion bar having a T-shaped cross section. Furthermore, by using single crystal silicon as the material, it is possible to realize a microstructure having a large mechanical Q value compared to polysilicon. Can be realized without generating a vibrating force in a direction perpendicular to the axis.

Further, according to the present embodiment, it is possible to realize a mechanical quantity sensor which is harder to break than the conventional one and can be downsized, and a mechanical quantity sensor having a higher mechanical Q value and higher sensitivity than the conventional one. . Further, since the movable portion is less likely to vibrate in the direction perpendicular to the axis of the torsion when swinging, a dynamic quantity sensor with less noise can be realized.

Further, according to the present embodiment, a microactuator that is harder to break than the conventional one and can be miniaturized can be realized, and the mechanical Q value is higher than the conventional one, so that the amplitude can be reduced when the resonance drive is performed. It is possible to realize a microactuator which can be made large and has high energy efficiency. Furthermore, since the movable portion is unlikely to vibrate in the direction perpendicular to the axis of torsion during swinging, a microactuator with high movement accuracy can be realized. Further, according to this embodiment, the microstructure of the present invention can be manufactured relatively easily.

Third Embodiment FIG. 14 is a perspective view for explaining a micro optical deflector according to a third embodiment of the present invention. 15 and 16 are a top view and a side view, respectively. In FIG. 16, a portion of the silicon single crystal thin plate 320 is cut away for easy understanding. FIG. 17 is a sectional view of the silicon single crystal thin plate 320 taken along a cutting line 306 in FIG. 14 for explaining the structure of the torsion spring which is a feature of the present embodiment.

In the micro optical deflector of this embodiment, the torsion springs 328 and 329 and the mirror 330 are integrally formed on the silicon single crystal thin plate 320 by bulk micromachining technology. Mirror 330
A movable core 341 made of a soft magnetic material is fixed to an end of the movable core 341. The torsion springs 328 and 329, which are features of the present embodiment, are flat torsion bars 321 and 32.
2, 323; 324, 325, and 326 are arranged in groups of three as shown in the cross-sectional view of FIG.

The surface of the mirror 330 is coated with a substance having a high light reflectance, and is supported by the torsion springs 328 and 329 so as to be swingable around a torsion axis which is a long axis thereof.

A fixed core 342 made of a soft magnetic material having the shape shown in FIG. 15 is disposed on the glass substrate 340, and a coil 345 is wrapped around the fixed core 342. Then, the silicon single crystal thin plate 320 and the glass substrate 340 are joined such that the surfaces of the movable core 341 and the fixed core 342 that are substantially parallel to each other are kept at a predetermined interval. That is, when the mirror 330 swings, the overlapping area (the cross-sectional area where the movable core 341 cuts off the magnetic flux generated by the fixed core 342) changes while these opposing surfaces remain substantially parallel. ing. Movable core 34
1 and the fixed core 342 form a closed series magnetic circuit including two gaps.

The operation of the optical deflector of this embodiment will be described with reference to FIG. When the coil 345 is energized, the fixed core 342 is excited. In FIG. 18, the fixed core 342
In the drawing, the near side is excited to the N pole, and the far side is excited to the S pole. Then, the movable core 341 is attracted in the direction in which the overlapping area of the opposing surfaces increases (the direction in which the magnetic flux generated by the fixed core 342 is attracted), that is, the direction of the arrow in FIG. The movable core 341 and the fixed core 342
As shown in FIG. 16, when the power is not supplied, the heights are different so that the overlapping area of the facing surfaces can be increased. Therefore, a counterclockwise rotational moment is generated around the torsion springs 328 and 329. ON / OFF of energization to coil 345 according to resonance frequency of mirror 330
Then, the mirror 330 moves the torsion spring 328,
Resonance occurs around 329. In this state, the mirror 330
Light can be scanned by inputting a light beam to the.

Next, a method for manufacturing the present optical deflector will be described.
First, a method for processing the silicon single crystal thin plate 320 will be described with reference to FIG. The left side in the figure is the cutting line 306 in FIG.
, And the right side is a cross-sectional view taken along a cutting line 309.

1. First, a seed electrode layer 360 is formed on one surface of a silicon single crystal thin plate 320. (A).

2. A thick resist layer 361 (for example, SU-8 manufactured by MicroChem) is formed on the seed electrode layer 360, and patterning for forming the movable core 341 is performed by photolithography (b).

3. A soft magnetic layer 362 is formed on the seed electrode layer 360 by electrolytic plating (c).

4. Thick resist layer 361 and seed electrode layer 3
60 is removed (d). The seed electrode layer 360 under the soft magnetic layer 362 remains as it is.

[0093] 5. On both sides of the silicon single crystal thin plate 320,
A mask layer 350 (for example, a resist or the like) is formed, and FIG.
Patterning for forming the single crystal thin plate 320 of the form shown in FIG. 4 is performed by photolithography (e).

6. Using an etching method such as ICP-RIE, vertical etching is performed from both surfaces to a certain depth (f). This depth defines the thickness of the horizontal bar portions on both sides of the torsion springs 328 and 329 having a cross-shaped cross section. Double the depth is the thickness of the bar.

7. The mask layer 350 is removed, and a new mask layer 351 is formed and patterned (g). This patterning differs from the patterning of the mask layer 350 in that the torsion springs 328 and 329 leave the striped mask layer 351 only in the central vertical bar portion.

8. Again, vertical etching is performed from the lower surface using an etching method such as ICP-RIE. Etching is performed in 6. The depth of the place dug by the silicon single crystal thin plate 32
This is performed until the center of the thickness reaches 0 (h).

9. Further, vertical etching is performed from the upper surface by using an etching method such as ICP-RIE. Etching is performed in 6. (I) until the place dug in step (1) penetrates the silicon single crystal thin plate 320. At the cross-shaped torsion springs 328 and 329, stop at the places where the horizontal bars on both sides are separated and left. The thickness of the central vertical bar portion (typically equal to the thickness of the horizontal bar portion) is defined by the width of the stripe portions on the upper and lower surfaces of the mask layer 351.

10. Finally, the mask layer 351 is removed (j).

Next, referring to FIG. 20, a glass substrate 340 will be described.
Will be described. FIG. 20 shows a section line 30 of FIG.
It is sectional drawing in 7.

1. Seed electrode layer 3 on one side of glass substrate 340
A film 70 is formed (a). 2. A thick resist layer 371 is formed on the seed electrode layer 370, and patterning for forming the fixed coil 342 is performed (b). 3. The lower wiring layer 3 of the coil 345 is placed on the seed electrode layer 370.
A film 72 is formed by electrolytic plating (c). 4. The thick resist layer 371 and the seed electrode layer 370 other than the lower wiring layer 372 are removed (d). 5. An insulating layer 373 is formed on the lower wiring layer 372, and patterning for forming the wiring layers 382 and 383 on both sides is performed (e).

6. A seed electrode layer 374 is formed on the insulating layer 373.
(F). 7. A thick resist layer 375 is formed on the seed electrode layer 374, and is patterned so that the soft magnetic layer 376 as the fixed core 342 and the wiring layers 382 and 383 on both sides can be formed (g). 8. On the portion of the seed electrode layer 374 without the thick film resist layer 375, the soft magnetic layer 376 and the wiring layers 382, 38 on both sides are provided.
3 is formed by electrolytic plating (h).

9. Thick resist layer 375 and seed electrode layer 37
4 (i). 10. The insulating layer 377 is formed again, and patterning for forming the upper wiring layer 380 is performed (j). With this patterning,
The insulating layer 377 is removed only at the top of the wiring layers 382 and 383 on both sides.

11. The seed electrode layer 37 is formed on the insulating layer 377.
8 is formed (k). 12. A thick resist layer 379 is formed on the seed electrode layer 378 and patterned (l). By this patterning, the thick resist layer 379 is formed on the wiring layers 382, 3 on both sides.
Only the area outside 83 is removed.

13. On the seed electrode layer 378, the upper wiring layer 3
80 is formed by electrolytic plating (m). 14． Finally, the thick resist layer 379 and the seed electrode layer 378
(N). Finally, the silicon single crystal thin plate 320 and the glass substrate 340 are joined so as to form an optical deflector as shown in FIG.

In the torsion springs 328 and 329 in which flat torsion bars are combined so as to have a cross-sectional shape as shown in FIG. 17, which is a feature of this embodiment, all the directions in which the bending rigidity of the flat torsion bars are low are not parallel. Therefore, the bending rigidity is high as a whole.

Unlike the torsion bar having a T-shaped cross section, the torsion spring of the present embodiment does not cause a large stress concentration, so that it is harder to break when a torsion spring having the same torsion spring constant and the same length is considered. There is. Also, considering the same allowable torsion angle, a shorter torsion spring can be provided as compared with a torsion bar having a T-shaped cross section.

Further, since single crystal silicon is used as a material, the mechanical Q value is larger than that of polysilicon.
Further, since the cross-sectional shape is symmetrical in the vertical and horizontal directions, it is possible to realize a torsion spring that does not generate an exciting force in a direction perpendicular to the axis of the torsion when swinging.

As described above, according to the present embodiment, it is possible to realize an optical deflector which is harder to break than the conventional one and can be downsized. Further, since the optical deflector of the present embodiment has a higher mechanical Q value than the conventional one, the amplitude is large and the energy efficiency is high when the resonance driving is performed. In addition, since the movable portion does not easily vibrate in the direction perpendicular to the torsion axis during swinging, an optical deflector with high accuracy and stable driving can be realized.

[Fourth Embodiment] FIG. 22 is a view for explaining an optical scanning display according to a fourth embodiment. The X light deflector 401 and the Y light deflector 402 are the same as the light deflector of the third embodiment. The controller 409 includes an X light deflector 401 and a Y light deflector 401.
By controlling the optical deflector 402, the laser beam 410 is scanned in a raster shape, and the laser oscillator 40 is controlled in accordance with information to be displayed.
By modulating 5, an image is displayed two-dimensionally on the screen 407.

By applying the optical deflector of the present invention to an optical scanning display, the optical deflector is harder to break and can be reduced in size than before, an optical scanning display with high energy efficiency, resistant to disturbance and stable. An optical scanning display capable of performing a customized display can be realized.

[0111]

As described above, according to the present invention, according to the present invention, the long axes are arranged in parallel and close to each other so that the long axes are parallel to each other, and the cross section of the plane perpendicular to the long axis is flat. , At least two of which are arranged such that the most flexible directions intersect
Since the torsion spring includes the two torsion bars, it is possible to realize a torsion spring having a large secondary moment of area I, while having a small secondary moment of area J. Therefore, a microstructure having high rigidity in the direction perpendicular to the torsion axis can be realized while ensuring sufficient compliance in the torsion direction.

Also, a compact microstructure having a short torsion spring for ensuring sufficient compliance in the torsion direction, and a compact microstructure having a short length for the torsion spring for securing a required torsion angle. Can be realized

When a single crystal is used as a material, a compact microstructure having a large mechanical Q value as compared with polysilicon can be realized. Furthermore, if the shape is symmetrical in the vertical and horizontal directions, it is possible to realize a micro structure that does not generate an exciting force in the direction perpendicular to the axis of torsion when swinging, and it is difficult for stress concentration to occur, so that the micro structure is hard to break Can be realized.

Further, according to the present invention, the torsion spring has a sufficient compliance in the torsion direction, so that the deflection angle can be increased. In addition, the torsion spring has a sufficient rigidity in the other directions, so that the torsion spring is resistant to disturbances and can be downsized. When a single crystal material is used, the mechanical Q value can be increased, and a micro optical deflector that is hard to vibrate in the direction perpendicular to the axis of the torsion spring when swinging and is hard to break can be realized.

Further, according to the present invention, since the torsion spring has a sufficient compliance in the torsion direction, the sensitivity can be increased, and since the torsion spring has a sufficient rigidity in other directions, it is resistant to disturbance and can be further reduced in size. When using a single crystal material, the mechanical Q value is high, so noise can be reduced, and when it swings, it is difficult to vibrate in the direction perpendicular to the axis of the torsion spring. A quantity sensor can be realized.

Further, according to the present invention, the torsion spring has a sufficient compliance in the torsion direction, so that the stroke can be increased. In addition, the torsion spring has a sufficient rigidity in the other directions, so that it is resistant to disturbance and can be downsized. Therefore, when a single crystal material is used, the mechanical Q value can be increased, and since it does not easily vibrate in the direction perpendicular to the axis of the torsion spring when swinging, the accuracy can be increased, and a microactuator that is hard to break can be realized.

Further, by using the production method of the present invention,
The microstructure, the micro optical deflector, the micro mechanical quantity sensor, and the micro actuator of the present invention can be manufactured relatively easily.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an optical deflector according to a first embodiment of the present invention.

FIGS. 2A and 2B are an exploded view for explaining an optical deflector according to a first embodiment, and a longitudinal sectional view of a torsion spring. FIGS.

FIG. 3 is a cross-sectional view illustrating an optical deflector according to the first embodiment.

FIG. 4 is a cross-sectional view of a torsion bar for explaining the optical deflector according to the first embodiment.

FIG. 5 is a diagram illustrating anisotropic etching of silicon.

FIG. 6 is a view for explaining a process for producing a silicon single crystal thin plate of the optical deflector of Example 1.

FIG. 7 is a diagram illustrating a process for manufacturing a glass substrate of the optical deflector according to the first embodiment.

FIGS. 8A and 8B are a perspective view illustrating an optical deflector according to a modification of the first embodiment and a cross-sectional view of a torsion spring;

FIG. 9 is a perspective view illustrating an acceleration sensor according to a second embodiment of the present invention.

FIG. 10 is an exploded view for explaining an acceleration sensor according to a second embodiment.

FIG. 11 is a cross-sectional view of a portion of a torsion spring for explaining an acceleration sensor according to a second embodiment.

FIG. 12 is a diagram illustrating a process for manufacturing a silicon single crystal thin plate of the acceleration sensor according to the second embodiment.

FIG. 13 is a diagram illustrating a process for manufacturing the glass substrate of the acceleration sensor according to the second embodiment.

FIG. 14 is a perspective view illustrating an optical deflector according to a third embodiment of the present invention.

FIG. 15 is a top view illustrating an optical deflector according to a third embodiment.

FIG. 16 is a partially cutaway side view illustrating an optical deflector according to a third embodiment.

FIG. 17 is a cross-sectional view illustrating a torsion bar of the optical deflector according to the third embodiment.

FIG. 18 is a diagram illustrating the operation principle of the optical deflector according to the third embodiment.

FIG. 19 is a diagram illustrating a process for manufacturing a silicon single crystal thin plate of the optical deflector according to the third embodiment.

FIG. 20 is a diagram illustrating a process for manufacturing a fixed core and a coil of the optical deflector according to the third embodiment.

FIG. 21 is a diagram illustrating a cross-sectional shape of an example of the torsion bar of the present invention.

FIG. 22 is a diagram illustrating an optical scanning display according to a fourth embodiment of the present invention.

FIG. 23 is a perspective view for explaining a conventional optical deflector.

FIG. 24 is an exploded view for explaining a conventional optical deflector.

FIG. 25 is a cross-sectional view for explaining a conventional optical deflector.

FIG. 26 is a sectional view of a portion of a torsion bar for explaining a conventional optical deflector.

FIG. 27 is a top view illustrating a conventional hard disk gimbal.

FIG. 28 is a cross-sectional view for explaining a conventional hard disk gimbal.

FIG. 29 is a view for explaining a process of manufacturing a conventional hard disk gimbal.

[Explanation of symbols]

110, 210, 340 Glass substrate 112, 212 Depressed portion 114, 116 Drive electrode 120, 220, 320, 520 Silicon single crystal thin plate 122-125, 221-226, 321-326
Flat torsion bar 128, 129, 228, 229, 328, 329, 5
28, 529 	 Torsion spring 128a, 129a Slope at the base of torsion spring 130, 330, 530 Mirror 132 Mirror support 150, 151, 250, 251, 350, 351
Mask layer 216 Detection electrode 230 Swing member 341 Movable core 342 Fixed core 345 Coil 360, 370, 374, 378 Seed electrode layer 362, 376 Soft magnetic material layer 361, 371, 375, 379 Thick resist layer 372 Lower wiring layer 373 377 Insulating layer 380 Upper wiring layer 382, 383 Side wiring layer 401 X light deflector 402 Y light deflector 405 Laser oscillator 407 Screen 409 Controller 410 Laser beam 1010 Insulating substrate 1014, 1016 Driving electrode 1020 Silicon thin plate 1022, 1024 , 2001, 2002 Torsion bar 1030, 2011 Mirror 1032 Mirror support 2020 Gimbal 2022, 2024 Roll torsion bar 2026, 2028 Pitch torsion bar 2030 Head support 2 31 the support frame 2091 type take-up silicon wafer 2092 sacrificial layer 2093 of polysilicon layer 2094 epoxy resin 2095 pad

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 26/08 G02B 26/08 E 26/10 104 26/10 104Z (72) Inventor Futa Hirose Ota, Tokyo 3-30-2 Shimomaruko-ku Canon Inc. (72) Inventor Takayuki Yagi 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hidemasa Mizutani 3-chome Shimomaruko, Ota-ku, Tokyo 30-2 Canon Inc. (72) Inventor Yasuhiro Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2H041 AA12 AB14 AC05 AC06 AZ02 AZ05 AZ08 2H042 DA12 DA19 DB08 DE00 2H045 AB16 AB22 AB73 2H049 AA06 AA12 AA44 AA60 AA62

Claims (32)

[Claims] 1. A substrate having at least one or more oscillating body, said oscillating body being elastically and freely swingably supported on said substrate by at least one set of torsion springs comprising a plurality of torsion bars. In the microstructure, a pair of torsion springs are arranged in parallel and close to each other so that their major axes are parallel to each other, and the cross-sectional shape of a plane perpendicular to the major axis is flat, and is most easily bent. A microstructure comprising at least two torsion bars arranged to cross directions. 2. A plurality of torsion bars constituting a set of torsion springs are arranged such that when cut along a cross section perpendicular to the long axis, the cross section has a symmetrical shape. The microstructure according to claim 1, wherein 3. A plurality of torsion bars constituting a set of torsion springs are arranged such that when cut at a cross section perpendicular to the long axis, the cross section shape is vertically and horizontally symmetric. The microstructure according to claim 1, characterized in that: 4. The microstructure according to claim 1, wherein said torsion bar is made of a single crystal material. 5. The microstructure according to claim 4, wherein said single crystal material is a silicon single crystal. 6. The microstructure according to claim 1, wherein the substrate, the oscillator, and the torsion spring are formed integrally from a common substrate. 7. A (100) silicon substrate is used, and a torsion spring is formed by anisotropic etching of the silicon substrate. The microstructure according to any one of claims 1 to 6, wherein: 8. The micro-device according to claim 7, wherein a surface with respect to the (100) silicon substrate surface, which defines an outer surface of a base of a torsion spring connected to the substrate or the oscillator, is a (111) surface. Structure. 9. The torsion spring according to claim 7, wherein said torsion spring has an inverted cross-section or an inverted C-shape.
Or the microstructure according to 8. 10. A flat substrate is used, and a torsion spring is formed by deep etching of the flat substrate, and a surface defining an outer surface of the flat substrate is defined by a plane perpendicular to or parallel to the flat substrate surface. The microstructure according to any one of claims 1 to 6, wherein the microstructure is formed. 11. The microstructure according to claim 1, wherein the torsion spring has a transverse cross-sectional shape of an inverted C or a U-shape, a cross, or an H-shape. 12. The torsion spring according to claim 1, wherein the corners of the torsion spring are lightly rounded by isotropic etching to reduce stress concentration on the corners of the torsion spring. 3. The microstructure according to claim 1. 13. A cross-sectional shape of at least two sets of torsion springs for supporting said oscillating body is different from each other with respect to torsion springs opposed to each other with the oscillating body interposed therebetween. 3. The microstructure according to claim 1. 14. The torsion spring according to claim 13, wherein the cross-sectional shapes of the opposing torsion springs are symmetrical with respect to a plane including a torsion center axis of the opposing torsion spring. Microstructure. 15. The oscillating body is a flat oscillating plate, and a cross-sectional shape of a torsion spring opposed to the oscillating plate is parallel to the oscillating plate including a torsion center axis of the opposed torsion spring. The microstructure according to claim 14, wherein the microstructures are arranged symmetrically with respect to a plane. 16. The oscillator according to claim 1, wherein one or two sets of torsion springs extend substantially along a straight line so that the rocker resiliently swings around the straight line relative to the substrate. The microstructure according to any one of claims 1 to 15, wherein the microstructure is freely supported. 17. A plurality of oscillating bodies, wherein the plurality of oscillating bodies are arranged in a nested manner, and each of the oscillating bodies is constituted by two sets of torsion springs extending substantially along each straight line. The microstructure according to any one of claims 1 to 15, wherein the microstructure is elastically supported on the substrate so as to swing freely around each of the straight lines. 18. The microstructure according to claim 17, wherein said straight lines extend at an angle to each other. 19. The microstructure according to claim 18, wherein said angle is 90 degrees. 20. A plurality of said oscillators, said plurality of oscillators being arranged in series with a torsion spring interposed therebetween, and an outermost oscillator being supported by said substrate with a torsion spring interposed therebetween. The microstructure according to any one of claims 1 to 15, wherein: 21. A micro mechanical quantity sensor comprising: the micro structure according to claim 1; and a displacement detecting means for detecting a relative displacement between the substrate and the oscillating body. 22. A microactuator comprising: the microstructure according to claim 1; and driving means for driving the oscillator relative to the substrate. 23. The microcontroller according to claim 22, wherein said driving means is an electromagnetic actuator comprising a fixed core, a coil surrounding said fixed core, and a movable core joined to said oscillator. Actuator. 24. The microstructure according to claim 1, wherein the driving means drives the oscillating body relatively with respect to the substrate, and the light reflecting means provided on the oscillating body comprises: A micro optical deflector comprising: 25. The micro-controller according to claim 24, wherein said driving means is an electromagnetic actuator comprising a fixed core, a coil surrounding the fixed core, and a movable core joined to the oscillator. Optical deflector. 26. The micro optical deflector according to claim 24, wherein said light reflecting means is a light reflecting surface or a diffraction grating. 27. A micro-optical deflector according to claim 24, a modulatable light source, and control means for controlling the modulation of said light source and the operation of the oscillator of said micro-optical deflector. An optical scanning display characterized by the above-mentioned. 28. The method for manufacturing a microstructure according to claim 7, wherein a mask layer is formed on both surfaces of the (100) silicon substrate, and A method for manufacturing a microstructure, comprising: a step of patterning according to the shape of an oscillator and a torsion spring; and a step of anisotropically etching the (100) silicon substrate. 29. The method according to claim 28, wherein the anisotropic etching is performed using an alkaline solution. 30. The method for manufacturing a microstructure according to claim 10, wherein a mask layer is formed on both surfaces of the substrate, and the mask layers on both surfaces are formed by the oscillator and the torsion spring. Patterning according to, and a step of deeply etching the substrate from one side,
A method for manufacturing a microstructure, comprising a step of etching the substrate deeper than another surface. 31. The method according to claim 30, wherein the substrate is a silicon substrate. 32. The method according to claim 2, further comprising the step of lightly and isotropically etching the corners of the torsion spring to round it, thereby reducing stress concentration thereon.
32. The method for manufacturing a microstructure according to any one of 8 to 31.