JP3230827B2 - Composite structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite structure particularly suitable for forming a microstructure forming a micro robot or the like.

[0002]

2. Description of the Related Art Recently, with the research and development of microrobots, means for forming a structure using thin film technology has become a useful means for constructing a micromachine. Moreover,
In the case of micromachines, in addition to planar and immovable structures, research on three-dimensional and movable structures has been actively conducted in recent years.

That is, FIG. 10 shows a micro-crank mechanism (IEEE, Proceeding of Micro Robot and
Tereoperators Workshop, '87.゛ From ICs to
Microstructures "), in which two polysilicon levers 1 and 2 formed on a silicon substrate are connected by a link 3. That is, the levers 1 and 2 can swing about shafts 4 and 5, respectively. And both ends of the link 3 are pivotally connected to one ends of levers 1 and 2, respectively.

[0004] In the crank mechanism including the lever and the like, the four joints perform the sliding motion in a sliding manner. As a result, the crank mechanism can realize the motion in the plane.

FIG. 11 shows a structure in which a silicon column 7 is erected on a silicon substrate 6 and another electrode 9 made of a silicon thin plate is supported by a polyimide beam 8 formed thereon. The polyimide member is a main material and also serves as an insulating material, and the silicon electrode is made movable by providing a potential difference between the substrate 6 and the supported silicon electrode 9 (IEEE, Proceeding o
f Micro ElectroMechanical Systems, '89 “Design an
d Fabrication of Movable SiliconPlates Suspended b
y Flexible Supports ").

[0006]

However, such a structure has the following problems. That is, in the structure shown in FIG. 10, a sliding motion can be performed, but the energy efficiency is deteriorated because the frictional force becomes relatively large as compared with the inertial force with miniaturization. , High speed, high load, and prolonged exercise cannot be performed.

Further, in the structure shown in FIG. 11, since a portion corresponding to the electrode 9 is supported only by the beam 8 made of polyimide, it is applied as a structure for a mechanism which is weak in strength and works on the outside world. It is impossible to do.

That is, in a microstructure manufactured by a conventional thin film technology, a member formed integrally is substantially planar, including a closed link structure, and capable of three-dimensional movement. Is very difficult to construct.

In view of the above, the present invention does not require three-dimensional and fine machining or thin film processing.
It is an object of the present invention to provide a composite structure capable of forming a three-dimensional structure, facilitating assembly, performing bending movement without sliding if necessary, and improving energy efficiency.

[0010]

According to a first aspect of the present invention, in a composite structure, a three-dimensional solid is formed by folding a plane pattern developed on a plane, and each of the three-dimensional solids is formed. The member is formed by a surface member made of a substance having a large Young's modulus, and a portion corresponding to a ridge portion of a three-dimensional solid connecting the surface members to each other is
A member made of a material having a small Young's modulus generates a suction force or a repulsive force between members made of the material having a large Young's modulus or between the member and the substrate, and the Young's modulus of the material located at the ridge line portion is reduced. One of the members made of a material having a large Young's modulus is swung relative to an adjacent member made of a material having a large Young's modulus or a substrate, with a member made of a small material as an axis. Also,
According to a second aspect of the present invention, in the first aspect, a voltage is applied between members made of a substance having a large Young's modulus or between the member and the substrate, so that an attractive force or a repulsive force is generated therebetween. It is characterized by doing so.

According to a third aspect of the present invention, in the first aspect, the three-dimensional solid body has at least one open surface, and the open portion is provided with a unidirectional actuator for changing the length of a diagonal portion. It is characterized by being. The fourth
According to a third aspect of the present invention, in the third aspect, a driven arm such as a leg or an arm is provided on at least one surface driven by the actuator.

[0012]

In the operation for forming the composite structure of the present invention, a final three-dimensional shape can be realized only by bending the above-mentioned substance having a small Young's modulus, and the three-dimensional shape can be stabilized on each surface as necessary. The members can be connected by mating connection,
Work effort can be significantly reduced.

Further, relative movement between the surface members made of a material having a high Young's modulus can be performed by bending the material having a low Young's modulus through an actuator or the like. In this case, sliding occurs. No exercise can be continued for a long time.

In the third aspect, when the length of the diagonal portion is changed by the actuator, a predetermined surface member is displaced in a predetermined direction. Therefore, the leg can be exercised by, for example, projecting the leg on the surface member.

Here, the "substance having a high Young's modulus" and the "substance having a low Young's modulus" are determined from the relative relationship between the two.

[0016]

FIG. 1 is a diagram showing a basic structure in which a composite structure according to the present invention is applied to a microstructure. That is, 10
Is a silicon substrate, and S on the silicon substrate 10
Bearing 1 made of SiO ₂ or PSG (phosphosilicate glass)
1, a first plate-shaped member 12 made of polysilicon, which is a substance having a relatively large Young's modulus, is attached to the first plate-shaped member 12 on one side of the plate-shaped member 12. Strip 1 made of polyimide, which is a substance with a smaller Young's modulus
3 is fixed to the other side of the strip 13,
Holes 1 made of the same polysilicon as the plate-shaped member 12 of FIG.
The second plate-shaped member 14 having 4a is connected.

Incidentally, such a structure is formed by standard thin film technology.

That is, first, Si is placed on the silicon substrate 10.
O ₂ or PSG (phosphosilicate glass) and polysilicon are laminated in this order by CVD. Next, a photoresist is applied to the upper surface of the polysilicon, and the patterns of the first plate member 12 and the second plate member 14 are drawn,
After the development, the polysilicon is etched according to the pattern to form polysilicon portions constituting the first and second plate-like members 12 and 14 shown in FIG.

Further, after a polyimide portion constituting the strip 13 is formed in a similar process, the photoresist is removed, and the SiO ₂ or PSG portion is dissolved away with hydrofluoric acid.

Since the second plate-like member 14 is provided with a plurality of (four in the figure) openings 14a by etching, the lower layer of SiO ₂ or PSG portion is in contact with the openings 14a. Reacts with hydrofluoric acid and completely dissolves away. On the other hand, the lower SiO ₂ or PSG portion 11 of the first plate member 12 does not react with hydrofluoric acid on the upper surface, and the reaction proceeds only on the side portion having a small reaction area, and as shown in FIG. The above remains on the silicon substrate 10.

In this manner, the Young's modulus is reduced by sandwiching the polyimide portion made of a material having a small Young's modulus on one side of the first plate-like member 12 attached to the support portion 11 made of SiO ₂ or PSG. A second plate-like member 14 made of large polysilicon is supported and connected in a cantilever manner.

Thus, the second plate-shaped member 14 can easily bend without sliding in the polyimide portion having a Young's modulus of 10% or less of polysilicon.

FIGS. 2 and 3 show a three-dimensional micro three-dimensional structure having a hexahedral structure. A silicon substrate and a SiO 2 substrate are formed by the same manufacturing method as in the first embodiment shown in FIG.
₂ or a PSG base 30 is fixed on a hexahedral polysilicon bottom surface 31. The hexahedral side surfaces 32a, 32a,
32b, 32c, 32d and the upper surface 32e are formed as a planar pattern obtained by developing a hexahedron on a plane.

That is, a polyimide portion 33 having a Young's modulus smaller than that of polysilicon is provided on each side of the bottom portion 31.
a, 33b, 33c, 33d, a square side surface portion 3
2a, 32b, 32c, and 32d are connected to each other,
A square upper surface portion 32e is further connected to the front end side of c through a polyimide portion 33e. On the side surface portion 32a,
Fitting grooves 34 _a1 , 34 _a2 extending in parallel with each side are provided on both sides, that is, both sides orthogonal to the polyimide portion 33a.
Is provided, and a fitting projection 35a is provided on the tip side.

On the side surfaces 32b and 32d, fitting protrusions _35b1 and _35d1 are respectively provided on the side portions near the side surface 32a, and the polyimide portions 33 are provided on the opposite side portions.
fitting grooves 34 extending in the directions orthogonal to b and 33d, respectively.
b, 34d. Further, fitting protruding pieces 35 _b2 and 35 _d2 are protrudingly provided on the tip side.

Fitting projections _35c1 and _35c2 are provided on both sides of the side surface 32c, and the upper surface 32e.
On both sides and the tip side of are formed _fitting grooves 34 _e1 , 34 _e2 , and 34 _e3 extending parallel to each side.

Therefore, each of the polyimide parts 33a, 33b,
In 33c, 33d and 33e, each side surface 32a-
And 32d and the upper surface portion 32e bent, as shown in FIG. 3, the insertion engagement side portions 32d, 32d of the fitting protruding pieces 35 _b1, 35 _d1 of the fitting groove 34 _a1, 34 _a2, respectively side face 32a Further, the fitting protrusions 35 _c1 and 35 _c2 of the side surface portion 32 _c are inserted and engaged with the fitting grooves 34 b and 34 d of the side surface portions 32 b and 32 d, respectively, and furthermore, the fitting grooves 34 _e1 and 3 of the upper surface portion 32 _e .
4 _e2 and 34 _e3 are fitted to the fitting projections 35 _a , 35 _b2 and 35 _d2 of the side portions 32 a, 32 b and 32 d, respectively.
A three-dimensional micro solid can be assembled. The dimensions of the three-dimensional micro three-dimensional body assembled here are about 150 μm in diagonal length of the surface member.

The microstructure having the hexahedral structure is simply interposed in the connecting portion between the surface members, and the non-sliding bending of the polyimide portion forming the three-dimensional ridge portion, the fitting groove, and the fitting protrusion. It is easy to assemble by fitting with the piece, and the shape stability after assembling can be sufficiently ensured. After the fitting, it can be fastened by a frictional force or an appropriate method.

FIG. 4 shows a microstructure according to the present invention which can be used as an actuator. Similarly to the above-described embodiments, a silicon substrate 40 is made of polysilicon via a base made of SiO ₂ or PSG. Substrate 41 made of
Are attached, and side surfaces 43a and 43b made of polysilicon are connected to opposite sides of the substrate portion 41 via polyimide portions 42a and 42b, and the other sides are connected via a polyimide portion 42c. A movable surface portion 44 made of polysilicon is connected. Then, the side portions 43a, 4
On one side of 3b, a spring portion 45 having a fitting groove 45a at the tip is integrally formed.

Accordingly, the side portions 43a and 43b and the movable surface portion 44 are respectively connected to the polyimide portions 42a and 42b.
And 42c, the fitting groove 45a of the spring portion 45 is fitted to the fitting protrusions 44 provided on both sides of the distal end portion of the movable surface portion 44.
A microstructure is formed by fitting into a.

When a voltage is applied between the silicon substrate 40 and the movable surface portion 44 by appropriate means, the silicon substrate 40 and the movable surface portion 4 made of polysilicon are applied.
Attraction force is generated by electrostatic force between the four, and the movable surface portion 44 moves toward the silicon substrate 40 with the polyimide portion 42c as an axis. When the applied voltage is removed, the spring 45
The movable surface portion 44 moves in a direction away from the silicon substrate 40 by the spring force of. Therefore, by repeatedly applying and removing the voltage, the movable surface portion can be brought into a vibrating state. The dimensions of the actuator shown here are about 500 μm in diagonal length of the movable surface portion.

FIGS. 5 and 6 show an embodiment in which a deformable three-dimensional solid body is formed by the composite structure of the present invention. In this case, the polysilicon member is removed from the silicon substrate. In this embodiment, a skeleton is formed by combining a plurality of simple regular triangles so as to be easily realized as a microactuator.

That is, according to the manufacturing method described above, as shown in FIG. 5, a polyimide portion 51a in which eight regular triangular polysilicon portions 50a, 50b,... , 51b ... 51g
Are formed as a planar development plane pattern connected via the. Then, both ends 52a, 5 of this pattern
By fitting or elastically connecting 2b, a cylindrical cube composed of eight equilateral triangles with upper and lower ends open is formed. That is, in this case, the upper and lower ends 5
3a and 53b are both regular squares, and are shifted from each other by 45 ° around the central axis (FIG. 6).

However, in this embodiment, since the upper and lower surfaces are spaces, it can be deformed.
By performing the OFF control, the polysilicon portion 50a,
50b... 50h can be deformed.

In the above embodiment, eight regular triangles are used as the polysilicon portion. However, the present invention is not limited to this shape, and a hollow structure can be constituted by a plurality of flat members.

FIG. 7 is a view showing an embodiment in which the structure shown in FIG. 6 is applied to a leg movement mechanism.
Actuators 54a, 54b, 54c, 54d are provided on each diagonal line so as to expand and contract the diagonal line, and one polysilicon portion 50c forming a side wall is provided.
Is provided with a leg 55. Here, the actuators 54a to 54d are configured to operate in pairs. That is, when the actuator 54a is contracted, the actuator 54b is extended, and when the actuator 54b is contracted, the actuator 54a is extended so that the actuator 54c and 54d are operated in the same manner. When one of the actuators in the group is operated, the other actuator may be free, and the operation of one of the actuators may be performed using the elastic force of the low Young's modulus portion.

Then, as shown in FIG. 7 (a), the actuator 54a is actuated and the vertices A,
When the position A is approached, the leg 55 moves downward, and the actuator 54b is actuated. When the position between the vertices B and B is approached, the leg 55 moves upward. When the actuator 54c is actuated to move the vertices C and C closer to each other, the leg 55 moves leftward in the drawing as shown in FIG. 7B, and the actuator 54d is actuated to move the vertices D and D closer to each other. Fig. 7
The leg 55 moves rightward in the drawing as shown in FIG.

Accordingly, the actuator 54a is actuated to move the leg 55 downward to come into pressure contact with, for example, the surface of a floor or the like.
When the distance is reduced, a force to the left acts on the leg 55 in FIG. 7 and the leg 55 moves to the right with the cube itself, and a walking operation can be performed by sequentially repeating this operation.

As described above, FIG. 7 shows the structure of one leg. For example, in order to make a ant-like movement, six legs are combined and three legs are alternately moved. You can also walk. Further, the above-described leg 55 can be used as a substitute for the arm or the like.

FIG. 8 shows an example in which the micro three-dimensional structure is applied to a wing flapping mechanism. Side plates 61 and 62 made of polysilicon are used.
The wings 63 are attached via hinge portions 63 and 64 made of polyimide. Further, linear actuators 65 and 66 similar to those described above are mounted inside between the side plates 61 and 62 and between the side plate 61 and the wing portion 63.

The linear actuator 6
By alternately contracting and expanding 5, 66, the wings 63 swing about the hinges 63, 64 made of polyimide. Therefore, if the vibration of the actuator is made to coincide with the resonance point of the microstructure, a flapping motion with good energy efficiency becomes possible.

The above-mentioned hinge portion made of polyimide may be replaced by a suitable rotation holding mechanism, or the allowable movable range of the fitting mechanism as described above may be used.

FIG. 9 shows a specific example of the structure shown in FIG. 8, in which a U-shaped plate 70a, 70b, 70c made of polysilicon and hinges 71a, 71b made of polyimide are used.
A wing portion 72 made of polysilicon is provided on both sides of the top end of the V-shaped main body portion 72 through hinge portions 71c and 71d made of polyimide.
a and 72b are connected. Similarly, a U-shaped drive mechanism 74 composed of polysilicon plate-like portions 73a, 73b, 73c and polyimide hinge portions 71e, 71f is provided with a cut 75 extending in a direction orthogonal to the hinge portion 71e and the like. Both ends of the drive mechanism 74 are separated from each other by polyimide polyimide hinges 71c, 71d with respect to the polysilicon wings 72a, 72b. It is connected by the parts 71g and 71h. Note that FIG.
The structure shown in (1) is constructed so that each hinge portion is bent to form a complete planar body.

The main body 72 and the drive mechanism 7
4 is insulated from each other by a hinge portion made of polyimide. Therefore, if an appropriate potential difference is applied between the plate-like portions 70b and 73b, an electrostatic force is generated, and an attractive force is generated between the two. When the applied voltage is removed, the two are separated from each other. Therefore, by repeating this alternately, the wing 72
a, 72b can be swung between a solid line position and a two-dot chain line position. Note that a repulsive force may be generated between the plate portions 70b and 73b by applying a potential difference between the plate portions 70b and 73b.

In each of the above embodiments, the conductor can be buried in the manufacturing process, and the space efficiency of the wiring portion can be improved. Furthermore, when the material having a low Young's modulus used for the refraction section is a material whose plastic deformation and elastic deformation can be controlled by heating, etc., it is plastically deformed so as to be bent as necessary, and the shape is kept stable. Can also be planned.

In the above embodiment, polysilicon is used as the substance having a high Young's modulus.
Aluminum, gold, silver, copper, nickel, glass, etc. can be used.In addition, as a material having a low Young's modulus, besides polyimide, polyamide, phenol, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyester , Epoxy, bismaleide, polyetheretherketone, polyamideimide and the like can be used.

[0047]

According to the present invention constructed as described above, 3
When realizing a three-dimensional solid, there is no need for three-dimensional and fine machining or thin film processing, it is only necessary to bend a planar development pattern at a ridge line made of a material with a low Young's modulus,
The labor and time can be significantly reduced as compared with the conventional assembling work performed for each independent part. In addition, after creating a development pattern by approximating a plane to a curved solid, it is only necessary to assemble the same method. Therefore, it is not necessary to prepare a special processing jig for each shape, and several hundred μm
Assembling of a three-dimensional microscopic solid having a size of about the same size can be easily performed. In addition, since it bends without sliding in the low Young's modulus portion, even if there is no friction and the bending motion is performed for a long period of time, it can be used with a small amount of energy and without causing deterioration in shape accuracy or destruction. The exercise state of time can be maintained.

If the flat portion is made of a member having a motion function, and the bent portion having a low Young's modulus is made of an insulating material in which an energy transmitting member is embedded, the thin film technology can also be used. In this case, the number of components can be reduced, and high reliability and high accuracy can be achieved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic structure of a composite structure of the present invention.

FIG. 2 is a plane development pattern diagram of a three-dimensional micro solid in one embodiment of the present invention.

FIG. 3 is a diagram illustrating a process of three-dimensionally configuring the pattern of FIG. 2;

FIG. 4 is a diagram showing another embodiment in which the composite structure of the present invention is configured as an actuator.

FIG. 5 is a plane development pattern diagram of a solid according to another embodiment of the present invention.

FIG. 6 is a perspective view of a solid formed by the pattern of FIG. 5;

FIG. 7 is an explanatory diagram of a motion state when the solid in FIG. 6 is applied to a leg motion mechanism.

FIG. 8 is a diagram showing the principle of applying the composite structure of the present invention to a fluttering mechanism.

FIG. 9 is a diagram showing an example in which the principle diagram of FIG. 8 is embodied;

FIG. 10 shows an example of a conventional microstructure.

FIG. 11 is a view showing another example of a conventional microstructure.

[Explanation of symbols]

10, 40 Silicon substrate 11 Bearing 12 First plate-shaped member 13 Strip made of polyimide 14 Second plate-shaped member 32a, 32b, 32c, 32d Side surface 32e Top surface 33a, 33b, 33c, 33d, 33e Polyimide Part 41 Substrate part 42a, 42b, 42c Polyimide part 44 Movable surface part 45 Spring part 50a ... 50h Silicon part 51a, ... 51g Polyimide part 54a, 54b, 54c, 54d Actuator 55 Leg 63, 72a, 72b Wing part

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B29K 83:00 B29K 83:00 B29L 31:00 B29L 31:00 (72) Inventor Hirofumi Miura 7-23- Tamagawa Gakuen, Machida-shi, Tokyo 2 (72) Inventor Isao Shimoyama 3-32-11-504 Akatsuka Shinmachi, Itabashi-ku, Tokyo (56) References JP-A-63-240092 (JP, A) JP-A-3-1777093 (JP, A) JP-A-4-19080 (JP, A) JP-A-50-50008 (JP, A) JP-A-62-19379 (JP, A) JP-A-4-132914 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) B81B 1/00 B29C 69/00 B29D 31/00 B81C 3/00 B29K 79:00 B29K 83:00 B29L 31:00

Claims (5)

(57) [Claims] 1. A three-dimensional solid is formed by folding a plane pattern developed on a plane, and each member constituting the three-dimensional solid is formed by a surface member made of a substance having a large Young's modulus. The parts corresponding to the ridges of the three-dimensional solid connecting the respective surface members to each other are:
It is composed of a member made of a material with a small Young's modulus.
Between or between members made of a substance having a high Young's modulus
A suction force or a repulsive force is generated between the
A member made of a material with a small Young's modulus
One of the members made of a material with a large Young's modulus
Contacting a member or substrate made of a substance with a large Young's modulus
A composite structure characterized by being swung in relation to the composite structure. 2. The method according to claim 1, wherein a voltage is applied between members made of a substance having a high Young's modulus or between the member and the substrate to generate an attractive force or a repulsive force therebetween. The composite structure according to claim 1, wherein 3. The three-dimensional solid body has at least one surface open.
Ri, characterized in that the unidirectional actuator is provided to vary the length of a diagonal line portion in a portion that is an opening, according to claim 1 composite structure according. 4. The composite structure according to claim 3, wherein at least one surface driven by the actuator is provided with a driven arm such as a leg or an arm. 5. The method according to claim 1, wherein the plane pattern forming the three-dimensional solid is integrally formed through a process of forming a thin film, exposing, printing, and etching. Composite structure.