JP2002321197A - 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 microstructure having an oscillating element which is vibration freely supported by a torsion spring that is difficult to twist vertical or parallel direction for the oscillating element. SOLUTION: The microstructure has a substrate 120 and an oscillating element 130. The oscillating element 130 is elastically and oscillation freely supported by torsion springs 128 and 129 for the substrate 120. The torsion springs 128 and 129 have at least a part whose cross sectional shape of a face vertical to the long axis inclines for the plane of the flat oscillating element 130.

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 swinging around an 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.

A conventional example of an optical deflector having a member that swings around an axis will be described. FIG. 23 shows U.S. Pat.
FIG. 1 shows a perspective view of an optical deflector disclosed in the specification of Japanese Patent Application Laid-open No. 1-No. FIG. 24 is an exploded view of the optical deflector for explaining its internal structure. FIGS. 25 and 26 are cut lines 1003 and 1006 in FIG. 23, respectively.
10 shows a cross-sectional view of the silicon thin plate 1020 in FIG.

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.

Here, the silicon thin plate 1020 is electrically grounded. Therefore, the drive electrodes 1014, 101
6 by applying a voltage alternately, an electrostatic attraction is applied to the mirror 1030, and the mirror 1030 is swung around the major axis of the torsion bar 1022, 1024.

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-mentioned problems has a substrate and at least one or more plate-shaped oscillators, and the oscillator has at least one oscillator. A torsion spring is a microstructure elastically supported by the substrate so as to freely swing freely, wherein the torsion spring has at least a part of a cross-sectional shape perpendicular to a major axis of the microstructure. Characterized by being inclined with respect to the plane of the oscillator. The cross-sectional shape in a plane perpendicular to the major axis of the torsion spring (also referred to as the cross-sectional shape or transverse cross-sectional shape of the torsion spring in this specification) is changed to the plane of a plate-shaped oscillator (the micro-optical deflector includes a reflecting surface or the like). Is formed so as to have a portion that is inclined with respect to the plane of the oscillating body.

Based on this basic configuration, the following more specific forms are possible. With the above basic configuration, the torsion spring can be easily made to pass through the vicinity of the center of gravity of the plate-shaped oscillating body. By configuring the torsion spring torsion axis center to pass near the center of gravity of the oscillator, the oscillator can be stably torsional vibrated. If the center of the torsion spring's torsion axis does not match the center of gravity of the oscillating body, this inconsistency will occur due to the torsional vibration of the oscillating body. Vibration and displacement are likely to occur. Therefore, unnecessary vibration of a micro structure such as a micro optical deflector can be reduced by using a configuration in which the center of the torsion passes near the center of gravity of the oscillator.

The sectional shape of a plane perpendicular to the major axis of the torsion spring can be easily made to have a symmetrical shape with respect to the plane including the torsion center axis. By forming the cross-sectional shape of the torsion spring so as to have a portion inclined with respect to the plane of the oscillating body, and by further making it symmetric,
A structure that is easy to twist around the axis of the torsion and that is more difficult to bend in the direction perpendicular to the axis of the torsion can be obtained.

The material of the torsion spring is preferably made of a single crystal material such as silicon single crystal. This makes it possible to realize a swing mechanism that can reduce internal loss and have high energy efficiency. In addition, by using a single crystal material as a material, a structure having a high mechanical Q value can be realized. 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). Using a (100) silicon single crystal substrate, the inclined surface of the torsion spring can be easily made to be the (111) plane of silicon single crystal.

Further, the single crystal material is a (100) silicon single crystal substrate, and a torsion spring is formed by anisotropic etching to define an outer surface thereof.
The slope with respect to the substrate surface can be set to be the (111) plane.
At this time, the surface with respect to the (100) substrate surface, which defines the outer surface of the base of the torsion spring connected to the substrate or the oscillating body, may be the (111) surface. (111)
Since the surface is formed with high precision and smoothness, the manufactured 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.

Typically, 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.

The cross-sectional shape of the torsion spring has a shape such as a V or inverted V shape, an X shape, a square shape, a square shape or an inverted square shape. The V-shape, the X-shape, and the C-shape are substantially symmetrical in the embodiments described later, but may be asymmetrical if necessary.

The corners (steep wedges and the like) of the torsion spring may be lightly rounded by isotropic etching to reduce stress concentration there.

The cross-sectional shape of the two or more sets of torsion springs that support the oscillator may be different for the torsion springs that face each other with the oscillator interposed therebetween. This makes it possible to provide a structure that is less likely to bend in a direction perpendicular to the axis of the twist while sufficiently maintaining the compliance of the twist. That is, in this structure, the directions in which the torsion springs opposed to 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, becomes unnecessary. Can be reduced.

Further, the cross-sectional shape of the torsion spring opposed to the rocking body is set to a plane including the torsion center axis of the opposed torsion spring (this plane is typically
It is a plane including the torsion center axis of the opposing torsion spring and parallel to the plane of the rocking plate, and this is the case in each of the modified examples described later). This allows the directions in which the torsion springs are easily bent to intersect symmetrically. Therefore, it is possible to effectively make the structure hard to bend in the direction perpendicular to the axis of the torsion, which is a preferable form in which the opposed torsion springs have different shapes.

As the form of the microstructure, there is one rocking body, and the rocking body is elastically moved relative to the substrate by one or a pair of torsion springs extending along a straight line. It can take a form supported around a free swing. The form of the pair of torsion springs is described in the following embodiment. However, if the rocking body is sufficiently lightweight and can be freely rocked and supported by one torsion spring, such a form may be used depending on the application. it can.

As another form of the microstructure, there are a plurality of the rockers, the plurality of rockers are nested, and each rocker is formed by a pair of torsion springs extending along each straight line. It is also possible to adopt a form in which the outer swinging body or the substrate is elastically supported to be able to swing freely around each of the straight lines. 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, the plurality of oscillators are arranged in series with a torsion spring interposed therebetween, 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 interposed 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 therebetween, and these three torsion springs are connected. As a form extending along a straight line, in this form, a large-mass oscillator is indirectly driven by driving a large-mass oscillator. In any case, the microstructure of the present invention is characterized in that at least a part of the cross-sectional shape of the torsion spring is inclined with respect to the plane of the plate-shaped oscillator, and the form depends on the application. It can be various.

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.

Further, a microactuator according to the present invention for solving the above-mentioned problems has a feature in that the microactuator has the above-mentioned microstructure and driving means for driving the oscillating body relative to the substrate. . As the driving means, a fixed core and the fixed core (made of a soft magnetic material)
And a movable core (made of a soft magnet or a hard magnet permanent magnet) joined to the oscillating body. The driving principle is different between the two, and in the former, the magnetic pole of the soft magnetic body is fixed. However, when a magnetic flux is generated in the fixed core, a driving force is generated in which the soft magnetic material is attracted into the magnetic flux in a direction in which the cross-sectional area of the soft magnetic material that cuts off the magnetic flux of the magnetic circuit increases, and is released from the magnetic flux when the magnetic flux disappears. On the other hand, in the latter case, the magnetic pole of the hard magnetic material is fixed, and the magnetic actuator (magnetic force (attractive force or repulsive force) between the fixed core and the movable core or between the magnetic poles is a driving force). , Or may utilize electrostatic attraction.

Further, a micro optical deflector according to the present invention for solving the above problems is provided with the micro structure, driving means for driving the oscillating body relative to the substrate, and provided on the oscillating body. It is characterized by having a light deflector provided.
The driving means is as described above. As the light deflector, there is a light reflection surface or a diffraction grating.
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), modulation of the light source, and micro-light 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 surfaces of a (100) single-crystal silicon substrate; The method includes a step of patterning according to the form of the oscillator and the torsion spring, and a step of anisotropically etching the (100) silicon substrate using an alkaline solution or the like.

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

[0035]

The operation of the microstructure of the present invention will be described. In the microstructure of the present invention, as described above, the cross-sectional shape of the torsion spring is inclined with respect to the plane of the oscillating body (in a micro-optical deflector, a deflector such as a reflection surface is provided here). With such a configuration, it is possible to effectively realize a structure that is hardly bent in directions perpendicular and parallel to the plane of the oscillator (reflection surface of the micro optical deflector). For example, in a micro-optical deflector, a functional element of an actuator (for example, in the case of an electrostatically driven actuator, Since the plate electrodes (parallel electrodes facing in parallel) are formed, vibration and displacement due to unnecessary force in the perpendicular and parallel directions are likely to occur with respect to the reflection surface. Therefore, by forming an inclined portion in the sectional shape of the torsion spring, rigidity against the vertical and parallel deflections can be increased with a simple structure, and unnecessary vibration of the micro optical deflector can be reduced.

[0036]

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 cutting line 109 of FIG. 2 for explaining the operation of the micro optical deflector of the present embodiment.
FIG. FIG. 4 is a cross-sectional view for explaining the structure of the torsion spring which is a feature of the present embodiment, and shows a cross section of the silicon single crystal thin plate 120 taken along a cutting line 106 in FIG.

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 may be omitted if possible. The silicon single crystal thin plate 120 is provided with a torsion spring 128 by bulk micromachining technology.
129 and the mirror 130 are integrally formed. The torsion springs 128 and 129 which are features of the present embodiment.
Has a V-shaped symmetrical cross section as shown in FIG. This is because one interior angle is 289.4 ° 7
It is rectangular and has two cross-sectional shapes inclined with respect to the plane of the mirror 130.

The mirror 130 is formed by coating the surface of a flat plate with a substance having a high light reflectance, and is supported by V-shaped torsion springs 128 and 129 so as to swing freely around its long axis. I have. Then, the mirror 130 is connected to the drive electrode 11 by the silicon single crystal thin plate 120.
The glass substrate 110 is kept at a predetermined distance from
It is located above (FIG. 3). The lower surface of the mirror 130 along the major axis of the torsion springs 128 and 129 is in contact with the top line of the mirror support 132 as shown in FIG. 3, and the mirror 130 rotates around the pivot axis along the top line. Swingable.

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, an electromagnet is provided instead of the driving electrode, and a 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. On both sides of the silicon single crystal thin plate 120,
A mask layer 150 (for example, SiO ₂ or silicon nitride manufactured by a low-pressure chemical vapor deposition method) is formed. As the silicon single crystal thin plate 120, a (100) substrate is used. And
The mask layer 150 is patterned by photolithography (a). In Figure 6, the substrate 120 upper surface, a lower surface side, respectively, two openings are formed in one opening and the width W _b of width W _a. Striped mask layer 150 between the two openings having a width W _b extends corresponds to the center line of the aperture width W _a. Width _{W a} is approximately set to the width of the top opening of the torsion spring 128 and 129 of the V-shape,
Width W striped mask layer 15 between the two openings of _b
The width of 0 is V-shaped torsion spring 128, 12
9 is set almost at the bottom width.

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). At this time, the side surface of the etched portion becomes a smooth (111) surface.

3. In the opening having a width of W _b,
The etching proceeds until it penetrates the substrate 120.
_{In the} opening having the width _a , the etching is stopped shortly before penetrating the substrate 120, and the bottom portions of the V-shaped torsion springs 128 and 129 are formed (d). As shown in FIG. 5, the (111) plane is different from the (100) plane.
Since it has an angle of 54.7 degrees, the relationship between the width w of the opening and the depth d of the V-groove is d = w / 2 · tan54.7 °. Therefore, as described above, the V-shaped torsion springs 128, 1
In order to 29 is _{formed, W a <2t / tan54.7 °} , W b> 2t
Satisfies the relationship of /tan54.7°. Here, t is the thickness of the silicon single crystal thin plate 120.

As described above, in the etching from the upper surface, before reaching the lower surface of the substrate 120, all the surfaces become (111) planes and the etching is stopped, so that a V-shaped groove is formed. The etching from the lower surface proceeds until the etching penetrates the substrate 120 and stops at the mask layer 150.

At this time, the mask layer 15 on the lower surface side is formed so that another etching penetration portion around the mirror 130 is also formed.
0 patterning is performed. Further, since the (111) plane is formed with high precision and smoothness, the formed V-shaped torsion springs 128 and 129 are not easily broken. Further, due to the anisotropic etching, the surfaces of the V-grooves at the roots of the torsion springs 128 and 129 (shown as 128a and 129a in FIG. 2A) are also shown in FIG.
Since the (111) slope is formed as shown in (b), stress concentration on the slope 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 sharp wedge portion of the V-groove or the corner 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 springs 128 and 129 having the V-shaped cross section can be manufactured only by performing the anisotropic etching once. As shown in FIG. 4, the torsion spring 1 of the optical deflector of this embodiment having a V-shaped cross section.
28 (129) has a structure that is easy to be twisted and hardly bends, like the conventional T-shaped torsion bar. Also, since the cross-sectional shape of the torsion springs 128 and 129 has two portions that intersect with the plane (mirror 130) of the plate-shaped oscillating body and is inclined, the torsion springs 128 and 129 bend in the directions perpendicular and parallel to the plane of the oscillating body. It has a difficult structure. Furthermore, according to the present embodiment, a microstructure having a larger mechanical Q value than polysilicon can be realized by using single crystal silicon as a material of the torsion spring.

Further, according to the present embodiment, by using a single crystal material for the material of the torsion spring, it is harder to break and the size can be reduced, and the vibration amplitude is large and the energy efficiency is high when driven by resonance. A micro optical deflector can be realized. Further, by using the manufacturing method of this embodiment, the microstructure of this embodiment can be manufactured relatively easily.

A modification of the first embodiment will be described. FIG.
(A) is a perspective view for explaining the micro optical deflector of this modification. Torsion springs 628, 629
Has a V-shaped cross section or an inverted V-shaped cross section surrounded by the substrate surface and the (111) plane of silicon. The side surfaces of the mirror 630 and the frame body 620 on which the reflection surface is formed have a shape in which the (111) plane of silicon is exposed. However, in FIG. . This is the same in other drawings.

The micro optical deflector of this modification is different from the first embodiment in that two sets of torsion springs 628 and 6 are provided.
29 is characterized in that the cross-sectional shape is different as shown in FIG. Thereby, it is possible to provide a structure that is easily twisted and hardly bends. Further, at the time of torsional resonance driving, the influence of unnecessary motion modes such as flexural vibration generated due to the structure of one torsion spring 628 or 629 or the influence of disturbance can be offset by the structure of the other torsion spring 629 or 628. The driving stability can be improved.

More specifically, as shown in FIG. 8B, the shape of the torsion springs 628 and 629 in the AA ′ section and the shape in the BB ′ section are mutually aligned on the substrate surface (the torsion springs 628 and 629). It is symmetrical with respect to the plane parallel to the plane of the mirror 630 (including the torsion center axis). Further, the center of gravity of the mirror 630 coincides with the torsional rotation axes of the two sets of torsion springs 628 and 629, and the driving stability can be further improved.

The micro optical deflector according to the present modification is manufactured by processing a silicon substrate using crystal anisotropic etching, as in the first embodiment. Although the manufacturing process described with reference to FIG. 6 may be used, the mask layer 150 on which the other torsion spring is formed is turned upside down from the pattern of FIG. As described above, the torsion springs 628 and 629 in which the portions having the flat cross section are combined upside down can be easily manufactured only by performing the anisotropic etching once.

According to this modification, a micro optical deflector which can easily process and cancel out the influence of disturbance at the time of driving caused by the respective torsion springs because the two torsion springs have different sectional shapes is provided. realizable.

Embodiment 2 FIG. 9 is a perspective view illustrating a micro optical deflector according to Embodiment 2 of the present invention. FIG.
FIG. 2 is an exploded view of the micro optical deflector for describing an internal structure. FIG. 11 shows a section line 1 in FIG.
6 shows a cross section of the silicon single crystal thin plate 120 at 06. A cross-sectional view taken along a cutting line 109 in FIG. 10 is the same as FIG.

In the micro optical deflector of the second embodiment,
A recess 112 is formed in the glass substrate 110. At the bottom of the recess 112, a pair of drive electrodes 114,
116 and a triangular prism-shaped mirror support 132 are arranged. The torsion spring 12 is applied to the silicon single crystal thin plate 120 by bulk micromachining technology.
2, 124 and the mirror 130 are integrally formed.
The torsion springs 122, 1
24 has an X-shaped cross section as shown in FIG. This shape, as is clear from FIG.
It is a dodecagon having two interior angles larger than 180 degrees and a rotationally symmetric shape. Further, it has a cross-sectional shape portion that intersects and is inclined with respect to the plane of the mirror 130.

The mirror 130 is formed by coating the surface of a flat plate with a substance having a high light reflectance, and is supported by the X-shaped torsion springs 122 and 124 so as to swing freely around its long axis. I have. Then, the mirror 130 is connected to the drive electrode 11 by the silicon single crystal thin plate 120.
The glass substrate 110 is kept at a predetermined distance from
It is located above. Torsion spring 12
The lower surface of the mirror 130 along the long axis of the mirror 124 is in contact with the top line of the mirror support 132, and the mirror 130 can swing around a swing axis along the top line.

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 method of manufacturing the above-mentioned optical deflector will be described in detail with reference to FIG. The process of FIG. 7 is also used in this embodiment. 13 (a) to 13 (g) are cut lines 1 in FIG.
6 (a) to 7 (e) show a cross section at 06.
The cross section at the section line 109 of 0 is shown.

As shown in FIG.
Is described.

1. On both sides of the silicon single crystal thin plate 120,
A mask layer 150 (for example, SiO ₂ or silicon nitride manufactured by a low-pressure chemical vapor deposition method) is formed. As the silicon single crystal thin plate 120, a (100) substrate is used. And
The mask layer 150 is patterned by photolithography (a). FIG. 12 shows a mask pattern used for this patterning. The mask pattern shown in FIG.
0 of the opening 191 having a width of W _a is formed along the outer shape and an opening 190 having a width of W _g is formed along the longitudinal center line of the torsion spring of a width W _b ing.

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 rapidly on the (100) plane and proceeds slowly on the (111) plane, the etching first proceeds such that the opening becomes narrower as the digging proceeds (b).

3. In the opening 190 having a width of W _g , before reaching the center of the substrate 120, all surfaces are (11).
1) Since the surface is formed and the etching is stopped, a V-shaped groove (a depth d _g and a width W _g as shown in FIG. 11) is formed. Further, in the opening 191 having _a width of Wa, the etching proceeds until it penetrates the substrate 120 (c). As shown in FIG. 5, the (111) plane is (10)
Since it has an angle of 54.7 degrees with respect to the 0) plane, the relationship between the width w of the opening and the depth d of the V-groove is d = w / 2 · tan54.7 °. Accordingly, _{where, W g <2t / tan54.7 °} , W a> 2t
Satisfies the relationship of /tan54.7°. Here, t is the thickness of the silicon single crystal thin plate 120.

4. After the holes from above and below the opening 191 have penetrated, the etching proceeds to the side (d, e).

5. The etching reaches the (111) plane and stops. At this time, the torsion spring 12
The cross section of 2, 124 becomes X-shaped (f). As shown in FIG. 11, the depth of the V-groove at the side of the X-shaped cross section is k _b and the width is t.
It is. At this time, since the (111) plane is formed with high precision and smoothness, the manufactured X-shaped torsion springs 122 and 124 are difficult to break. Furthermore, the torsion spring 12
The surface of the V-groove at the base of 2, 124 (1 in FIG. 10A)
22a and 124a) also have a (111) slope as shown in FIG. 10 (b), 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. .

6. After the anisotropic etching, isotropic etching may be performed with a gas or an acid to round the sharp wedge portion of the V-groove or the corner of the torsion spring. In this way, stress concentration on these portions can be reduced.

7. Next, the mask layer 150 is removed (g). 8. Finally, the mirror 130 is washed, and a light reflection film is formed on the surface.

The method for processing the glass substrate 110 is the same as that described in the first embodiment with reference to FIG.

As described above, according to the manufacturing method of this embodiment, the torsion springs 122 and 124 having the X-shaped cross section can be manufactured only by performing the anisotropic etching once. As shown in FIG. 11, the torsion spring 122 (124) of the optical deflector of this embodiment having an X-shaped cross section has a large secondary moment of area I, despite a small secondary moment of area J. There are features. In addition, since the cross-sectional shape is rotationally symmetric, a microstructure that does not generate an exciting force in the direction perpendicular to the axis of torsion when swinging can be realized. Furthermore, torsion spring 1
The cross-sectional shapes of the cross-sections 22 and 124 have crossing portions that are inclined with respect to the plane (mirror 130) of the plate-shaped oscillator, so that the structure is more difficult to bend in the directions perpendicular and parallel to the plane of the oscillator. I have.

Also according to the present embodiment, by using single crystal silicon as the material of the torsion spring, it is harder to break and more compact than polysilicon,
A microstructure having a large vibration amplitude and high energy efficiency and a large mechanical Q value when driven by resonance can be realized.

Further, it is difficult to vibrate in the direction perpendicular to the axis of the torsion spring when swinging, so that a highly accurate micro optical deflector can be realized. A micro optical deflector with a large amplitude and high energy efficiency can be realized. Further, by using the manufacturing method of this embodiment, a torsion spring having an X-shaped cross section can be manufactured relatively easily.

A modification of the second embodiment will be described. FIG.
(A) is a perspective view for explaining the micro optical deflector of this modification. Torsion springs 728, 729
Has a flat cross section surrounded by the substrate surface 720 and the (111) plane of silicon.

The micro optical deflector of this modification is different from the second embodiment in that two sets of torsion springs 728 and 7 are provided.
29 is characterized in that it has a different cross-sectional shape. Thereby, it is possible to provide a structure that is easily twisted and hardly bends. Further, at the time of torsional resonance drive, 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 the drive stability can be improved. .

More specifically, as shown in FIG. 14B, the shape of the torsion bar 728 taken along the line AA ′ and the shape of the torsion bar 729 taken along the line BB ′ correspond to the substrate surface 72.
0 (also the plane of the mirror 730; more precisely, a plane parallel to the plane of the mirror 730 including the torsion bar 728, 729 torsion center axis). In addition, the center of gravity of the two sets of torsion bars 728 and 729 (which is also the center of gravity of the mirror 730) coincides with the torsional rotation axis, and the driving stability can be further improved.

The micro optical deflector according to the present modification is manufactured by processing a silicon substrate using crystal anisotropic etching, as in the second embodiment. FIG. 15 is a cross-sectional view illustrating the manufacturing process.

First, mask layers 731 and 732 made of silicon nitride are formed on both surfaces of a single crystal silicon substrate 720 having a plane orientation of (100) by low pressure chemical vapor deposition (see FIG. 15A). Next, the mask layers 731 and 732 are patterned by photolithography and dry etching using CF ₄ gas (FIG. 15B).
reference). Here, the mask layer is left on the upper and lower surfaces of the substrate 720 by the width of the torsion bar, and these remaining mask layer portions are shifted left and right according to the inclination of the torsion bar. Next, silicon 720 is subjected to crystal anisotropic etching using a 30% aqueous potassium hydroxide solution heated to 100 ° C. (see FIG. 15C). Further, the substrate 720 is penetrated by continuing this etching (see FIG. 15D). The etching direction at this time is as shown in the figure. Further, by continuing the above-mentioned etching, a leaf spring-like torsion bar 728 or 729 having a Si (111) side surface is formed (FIG. 15).
(E)). The other torsion bar 729 or 728 on the opposite side of the mirror 730 is also formed at the same time. In this portion, the mask layer is patterned in an upside down manner from FIG. 15 and anisotropically etched. .

Here, the mask layer may be removed. Further, a reflection film may be formed on the surface of the reflection surface. As described above, according to the manufacturing method of this modification, the torsion bar 7 having a flat cross section can be obtained only by performing the anisotropic etching once.
28 and 729 can be easily manufactured.

According to this modification, the following micro optical deflector can be provided. Here, the two sets of torsion springs have a simple structure in which each is a single leaf spring, and the process is easy. It is possible to cancel the influence of disturbance at the time of driving caused by each torsion spring. Furthermore, the center of gravity of the two sets of torsion bars and the torsional rotation axis can be easily matched,
Driving can be easily stabilized, and the torsion bar has no stress concentration portion and has a structure that is hard to break.

Third Embodiment FIG. 16 is a perspective view for explaining a micro optical deflector according to a third embodiment of the present invention. FIG.
FIG. 7 is an exploded view of the micro optical deflector for explaining the internal structure. FIG. 18 is a cross-sectional view illustrating a cross section of the silicon single crystal thin plate 120 taken along a cutting line 106 in FIG. 16 and illustrating a structure of a torsion spring which is a feature of the present embodiment. Cutting line 109 in FIG.
Is the same as FIG.

In the micro optical deflector of the third embodiment,
A recess 112 is formed in the glass substrate 110. At the bottom of the recess 112, a pair of drive electrodes 114,
116 and a triangular prism-shaped mirror support 132 are arranged. The torsion spring 12 is applied to the silicon single crystal thin plate 120 by bulk micromachining technology.
8, 129 and the mirror 130 are integrally formed.
The torsion spring 128, 1
29 is a flat torsion bar 122, 123;
As shown in FIG. 18, two sets 125 are arranged in pairs, and the cross-sectional shape is arranged in an inverted C shape.

The mirror 130 is formed by coating the surface of a flat plate with a substance having a high light reflectance, 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. These configurations are the same as those in the first and second embodiments.

The method of manufacturing the optical deflector of this embodiment will be described in detail below with reference to FIG. The process of FIG. 7 is also used in this embodiment. FIGS. 19A to 19E show cross sections taken along a cutting line 106 in FIG. 16, and FIGS.
Represents a cross section taken along a cutting line 109 in FIG.

As shown in FIG.
Is 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 accuracy and smoothness, the formed torsion springs 128 and 129 having the inverted C-shaped cross section are hard to be broken. Further, the surface of the V-groove at the root of the torsion springs 128 and 129 by the anisotropic etching (FIG. 1)
7 (a) are indicated by 128a and 129a).
As shown in (cross-sectional view of the silicon single crystal thin plate 120 at the cutting line 190 in FIG. 17A), the (111) slope is formed, so that stress concentration can be reduced, and the reliability of the torsion spring is improved. 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.

The method for processing the glass substrate 110 is the same as that described in the first embodiment with reference to FIG.

As described above, according to the manufacturing method of this embodiment, the torsion bars 122, 123; 124, and 125 having a flat cross section 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. 18, in the torsion spring 128 (129) of the optical deflector of this embodiment,
Two flat torsion bars 122 (124) and 123
(125) 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. Further, since the cross-sectional shape of the torsion springs 128 and 129 has two portions which intersect with the plane of the flat rocking body (mirror 130), they are perpendicular to the plane of the rocking body.
It has a structure that is less likely to bend in the parallel direction.

According to the present embodiment, unlike a torsion bar having a T-shaped cross section, a large stress concentration does not occur, so that a microstructure that is more difficult to break when a torsion spring having the same torsion spring constant and the same length is considered. 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 the present embodiment, it is possible to realize a micro optical deflector that is harder to break, can be made more compact, 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 third embodiment will be described with reference to FIG. FIG. 20 is a perspective view (a) and a cross-sectional view (b) illustrating a micro optical deflector according to a modification of the third embodiment of the present invention.
It is. 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. FIG.
Even if it is 0, the side surface shape of the reflection surface 530 and the frame 520 is a shape in which the (111) plane of silicon is exposed, but is drawn as a side surface perpendicular to the reflection surface 530 for simplicity.

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 correspond to the substrate surface (more precisely, the reflection surface including the torsion center axis of the opposed torsion spring). (Plane parallel to 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 third embodiment (only the pattern of the mask layer 150 shown in FIG. 19 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 sets of 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. This makes it possible to realize a micro optical deflector having a structure in which the torsion bar has no stress concentration portion and is hardly broken.

[Fourth Embodiment] FIG. 21 is a schematic perspective view for explaining a micro optical deflector according to a fourth embodiment of the present invention. Also in the micro optical deflector of this embodiment, the torsion spring (not shown) and the mirror 330 as described in the above embodiment or the modification are integrally formed on the silicon single crystal thin plate by the bulk micromachining technology. ing. A movable core 341 made of a soft magnetic material is fixed to an end of the mirror 330. Mirror 330
Has a surface coated with a substance having a high light reflectance, and is supported by a torsion spring so as to be swingable around a torsion axis which is its long axis.

On the other hand, on a glass substrate (not shown), a fixed core 342 made of a soft magnetic material is arranged.
A coil (not shown) orbits the fixed core 342. Then, the silicon single crystal thin plate and the glass substrate 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 oscillates, the overlapping area (the cross-sectional area of the movable core 341 that cuts off the magnetic flux generated in the fixed core 342) changes while these opposing surfaces remain substantially parallel. ing. The movable core 341 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. When the coil is energized, the fixed core 342 is excited. FIG. 21 illustrates a state where the near side of the fixed core 342 in the figure 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 facing surfaces increases (the direction in which the movable core 341 is attracted to the magnetic flux path generated in the fixed core 342), that is, the direction of the arrow in FIG. Since the movable core 341 and the fixed core 342 are arranged at different heights when power is not supplied so that the overlapping area of the opposing surfaces can be increased, a counterclockwise rotational moment is generated around the torsion spring. When energization of the coil is turned ON / OFF in accordance with the resonance frequency of the mirror 330,
The mirror 330 resonates around the torsion spring. In this state, light rays can enter the mirror 330 to perform light scanning.

[Embodiment 5] FIG. 22 is a view for explaining an optical scanning display of Embodiment 5. The X light deflector 401 and the Y light deflector 402 are the same as the light deflectors of the above-described embodiments and the modifications. The controller 409 controls the X light deflector 401 and the Y light deflector 402 to scan the laser beam 410 in a raster shape and modulate the laser oscillator 405 in accordance with the information to be displayed.
The image is displayed two-dimensionally on the top.

By applying the optical deflector of the present invention to an optical scanning display, an optical scanning display which can form a fine image and has high energy efficiency can be realized.

[0110]

As described above, according to the present invention,
The cross-sectional shape of the torsion spring supporting the oscillator
Since the torsion spring is formed so as to have an inclined part with respect to the plane of the flat rocking body, it is difficult for the torsion spring to bend in the vertical and parallel directions to the plane of the rocking body, enabling accurate rocking movement of the rocking body The microstructure can be effectively realized. Further, if the material is a single crystal material, it is possible to provide a microstructure having a large mechanical Q value having a torsion spring that is easily twisted and hardly bends. In addition, there is little noise due to the high mechanical Q value,
A highly sensitive dynamic quantity sensor can be provided. Also, since the mechanical Q value is high, the amplitude is large when driven by resonance,
Further, a microactuator with high energy efficiency can be provided. Further, since the mechanical Q value is high, it is possible to provide a micro optical deflector having a large amplitude when driven by resonance and having high energy efficiency.

By applying the optical deflector of the present invention to an optical scanning display, an optical scanning display capable of forming a fine image can be provided. Furthermore, by using the manufacturing method of the present invention, the micro structure, 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 bar. FIGS.

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

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 Example 1 and the like.

FIGS. 8A and 8B are a perspective view for explaining an optical deflector according to a modification of the first embodiment of the present invention, and a cross-sectional view of a torsion spring.

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

FIGS. 10A and 10B are an exploded view for explaining an optical deflector according to a second embodiment, and a longitudinal sectional view of a torsion spring; FIGS.

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

FIG. 12 is a plan view illustrating an optical deflector according to a second embodiment.

FIG. 13 is a diagram illustrating a process for producing a silicon single crystal thin plate of the optical deflector according to the second embodiment.

FIGS. 14A and 14B are a perspective view for explaining an optical deflector according to a modification of the second embodiment of the present invention, and a cross-sectional view of a torsion spring.

FIG. 15 is a diagram illustrating a process for manufacturing a silicon single crystal thin plate of an optical deflector according to a modification of the second embodiment.

FIG. 16 is a perspective view illustrating an optical deflector according to a third embodiment of the present invention.

17A is an exploded view for explaining the optical deflector according to the third embodiment, and FIG.

FIG. 18 is a cross-sectional view of a part of a torsion spring for explaining an optical deflector according to a 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.

FIGS. 20A and 20B are a perspective view for explaining an optical deflector according to a modification of the third embodiment of the present invention, and a cross-sectional view of a torsion spring; FIGS.

FIG. 21 is a schematic perspective view illustrating the operation principle of the optical deflector according to the fourth embodiment.

FIG. 22 is a diagram illustrating an optical scanning display according to a fifth 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 glass substrate 112 recess 114, 116 drive electrode 120, 620, 720 silicon single crystal thin plate 122, 123, 124, 125, 128, 129, 5
28, 529, 628, 629, 728, 729
Torsion spring (torsion bar) 122a, 124a, 128a, 129a Slope at the base of torsion spring 130, 330, 630, 730 Mirror 132 Mirror support 150, 731, 732 Mask layer 190, 191 Opening 341 Movable core 342 Fixed core 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 2031 Support frame 20 91 Silicon wafer for molding 2092 Sacrificial layer 2093 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 26/10 104Z 26/10 104 7/18 Z (72) Inventor Futa Hirose Ota, Tokyo 3-30-2 Shimomaruko-ku, Canon Inc. (72) Inside the Canon Takayuki Yagi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hidemasa Mizutani 3-chome Shimomaruko, Ota-ku, Tokyo No. 30-2 Canon Inc. (72) Inventor Yasuhiro Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2H041 AA12 AB14 AC04 AZ01 AZ08 2H043 AE16 AE18 BB05 BC08 2H045 AB06 AB10 AB16 AB73 2H049 AA06 AA37 AA44 AA50 AA68 AA69

Claims (30)

[Claims] 1. A micro-computer comprising: a substrate; and at least one plate-shaped oscillating body, wherein the oscillating body is elastically supported by the at least one torsion spring such that the oscillating body is freely swingable. In the structure, the torsion spring is characterized in that at least a part of a cross-sectional shape of a surface perpendicular to a major axis thereof is inclined with respect to a plane of the plate-shaped oscillator. 2. The microstructure according to claim 1, wherein a torsional center axis of said torsion spring passes near a center of gravity of said plate-shaped oscillator. 3. The microstructure according to claim 1, wherein a cross-sectional shape of a plane perpendicular to a major axis of the torsion spring has a symmetrical shape with respect to a plane including the torsion center axis. 4. The microstructure according to claim 1, wherein said torsion spring 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 5, wherein the inclined surface of the torsion spring is a (111) plane of silicon single crystal. 7. The microstructure according to claim 1, wherein the substrate, the oscillator, and the torsion spring are integrally formed from a common single crystal material substrate. 8. The single crystal material is a (100) substrate,
The microstructure according to claim 5, 6 or 7, wherein the torsion spring is formed by anisotropic etching, and a slope of the torsion spring with respect to the (100) substrate surface that defines the outer surface is a (111) surface. 9. The microstructure according to claim 8, wherein a surface with respect to the (100) substrate surface, which defines an outer surface of a base portion of a torsion spring connected to the substrate or the oscillator, is a (111) surface. . 10. The torsion spring according to claim 1, wherein the torsion spring has a V-shaped cross section, an inverted V-shaped cross section, an X-shaped cross section, a U-shaped cross section, or a C-shaped or inverted C-shaped cross section. The microstructure according to any one of the above. 11. 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. 12. 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 across said oscillating body. 3. The microstructure according to claim 1. 13. The torsion spring according to claim 12, wherein the cross-sectional shapes of the torsion springs opposed to each other with the rocking member interposed therebetween are symmetrical with respect to a plane including the torsion center axis of the opposed torsion springs. Micro structure. 14. A cross-sectional shape of the torsion springs opposed to each other with the rocking plate interposed therebetween is symmetrically arranged with respect to a plane including a torsion center axis of the opposed torsion springs and parallel to a plane of the rocking plate. 14. The method according to claim 13, wherein
The described microstructure. 15. An oscillator according to claim 1, wherein said oscillator is elastically movable relative to said substrate by one or a pair of torsion springs extending along a straight line. The microstructure according to claim 1, wherein the microstructure is supported. 16. A plurality of said rocking bodies, said plurality of rocking bodies being arranged in a nested manner, and each rocking body is formed by a pair of torsion springs extending along each straight line, and the rocking body on the outer side thereof or said rocking body. The microstructure according to any one of claims 1 to 14, wherein the microstructure is elastically supported on the substrate so as to freely swing around each of the straight lines. 17. The microstructure according to claim 16, wherein said straight lines extend at an angle to each other. 18. The microstructure according to claim 17, wherein said angle is 90 degrees. 19. A plurality of oscillators are arranged in series with a torsion bar interposed therebetween, and the outermost oscillator is supported by the substrate with a torsion bar interposed therebetween. The microstructure according to any one of claims 1 to 14, wherein: 20. 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 oscillator. 21. A microactuator comprising: the microstructure according to claim 1; and driving means for driving the oscillator relative to the substrate. 22. A micro-actuator according to claim 21, 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. . 23. A microstructure according to claim 1, wherein said microstructure comprises a driving means for driving said oscillator relative to said substrate, and a light deflector provided on said oscillator. A micro optical deflector comprising: 24. The micro-micrometer according to claim 23, wherein a part of a cross-sectional shape of a surface perpendicular to a major axis of the torsion spring is inclined with respect to a surface on which the light deflector is formed. Optical deflector. 25. An electromagnetic actuator according to claim 23, 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. Micro optical deflector. 26. The light deflector is a light reflecting surface or a diffraction grating.
The micro optical deflector as described. 27. A micro-optical deflector according to claim 23, a light source capable of modulation, and control means for controlling modulation of said light source and operation of an oscillator of said micro-optical deflector. An optical scanning type display characterized by the above-mentioned. 28. The method for manufacturing a microstructure according to claim 8, wherein a mask layer is formed on both surfaces of the (100) single crystal silicon substrate, and the mask layers on both surfaces are formed. Patterning according to the form of said oscillator and torsion spring, and anisotropically etching said (100) silicon substrate. 29. The method according to claim 28, wherein the anisotropic etching is performed using an alkaline solution. 30. The method according to claim 30, further comprising the step of lightly and isotropically etching the corners of the torsion spring to round the corners of the torsion spring to reduce stress concentration on the corners of the torsion spring. The method for producing a microstructure according to claim 28 or 29.