JP2003153518A - Planar type electromagnetic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption when a movable part oscillates in a planar type electromagnetic actuator which oscillates the movable part of a semiconductor substrate sandwiched by a pair of magnetic-field generating means in the two-axis directions. SOLUTION: In this planar type electromagnetic actuator in which the movable part 5 having an outer movable plate 3 and an inner movable plate 4, a first torsion bar 6 for journaling the outer movable plate 3, and a second torsion bar 7 for journaling the inner movable plate are integrated and formed with the semiconductor substrate 2, driving coils 8, 9 are formed at the movable part 5, and the magnetic-field generating means 10a, 10b for supplying a magnetic field H0 are disposed so as to sandwich the semiconductor substrate 2 and face each other, the magnetic fields generated by the magnetic-field generating means 10a, 10b improve magnetic force supplied to the driving coils 8, 9. As a result, the magnetic force supplied to the driving coils 8, 9 can be improved by the magnetic field H0 , thus reducing the power consumption generated when the movable part 5 oscillates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar electromagnetic actuator capable of freely swinging a movable portion of a semiconductor substrate sandwiched by a pair of magnetic field generating means in two orthogonal axial directions by using an electric signal. In particular, since the magnetic field generated by the pair of magnetic field generating means improves the magnetic force applied to the drive coil of the movable part, it is possible to reduce the power consumption when the movable part swings. The present invention relates to a planar electromagnetic actuator.

[0002]

2. Description of the Related Art In recent years, development of a technology relating to an ultra-small planar electromagnetic actuator which can be formed by utilizing semiconductor manufacturing technology has been advanced, and an example of such technology is described in Japanese Patent Publication No. 2987750. There was something that was done. As shown in FIG. 5, for example, a conventional planar electromagnetic actuator 1 of this type includes a movable portion 5 including a frame-shaped outer movable plate 3 and an inner movable plate 4 arranged inside the semiconductor substrate 2, as shown in FIG. First torsion bars 6 and 6 pivotally supporting the outer movable plate 3 and the inner movable plate 4 whose axial direction is orthogonal to the first torsion bars 6 and 6.
Is integrally formed with the second torsion bar 7, 7, which pivotally supports the above, and the first drive coil 8 and the second drive coil 9 are formed at the peripheral portions of the outer movable plate 3 and the inner movable plate 4, respectively. ,
A pair of magnetic field generating means 10a and 10b for applying a magnetic field to the drive coils 8 and 9 are arranged to face each other with the semiconductor substrate 2 sandwiched in the diagonal direction of the movable portion 5. As a result, as shown in FIG. 6, a magnetic field H ₀ is generated from the magnetic field generating means 10a to 10b, and this magnetic field H ₀ obliquely moves the movable portion 5 (see FIG. 5) of the semiconductor substrate 2. It was supposed to cross.

In such a planar type electromagnetic actuator 1, when current flows through the first drive coil 8 and the second drive coil 9 provided on the peripheral portions of the outer movable plate 3 and the inner movable plate 4, respectively. The Lorentz force acts on the movable portion 5 so that the movable portion 5 can swing in two dimensions. The operation of such a planar electromagnetic actuator 1 will be described below. Here, the magnetic field H ₀ shown in FIG.
Is a transverse component magnetic field H ₁ orthogonal to the axial direction of the first torsion bars 6 and 6 shown in FIG. 5, and a longitudinal component magnetic field orthogonal to the axial direction of the second torsion bars 7 and 7 shown in FIG. H
_It will be explained by decomposing it into vector components with ₂ .

First, electric power is supplied to the electrode pad 11 shown in FIG. 5 to provide a first portion provided on the peripheral portion of the outer movable plate 3.
When a current is passed through the drive coil 8, a Lorentz force F ₁ shown in the following equation (1) acts on the first drive coil 8 by the lateral component magnetic field H ₁ shown in FIG. F ₁ = n × I ₁ × B ₁ (1) Here, n is the number of turns of the drive coil 8, I ₁ is the current flowing through the drive coil 8, and B ₁ is the magnetic flux density of the lateral component magnetic field H ₁ .

The Lorentz force F ₁ causes the movable portion 5 to rotate about the axial direction of the first torsion bars 6 and 6, so that the Lorentz force F ₁ and the first torsion bar 6 are twisted and returned. It stands still at a position where it balances with the force to be tried. From the above formula (1), the Lorentz force F
_{Since 1} is proportional to the current I ₁ flowing through the drive coil 8, by controlling the current I ₁ , the movable portion 5 is set to the first position.
The angle of rotation of the torsion bars 6, 6 about the axial direction is controlled.

Further, the second electric power supply is provided to the electrode pad 12 shown in FIG.
When a current flows through the drive coil 9, the second drive coil 9
The vertical component magnetic field H ₂ shown in FIG. Therefore, by controlling the current flowing through the drive coil 9, the angle at which the movable portion 5 shown in FIG. 5 rotates about the axial direction of the second torsion bars 7, 7 is controlled. As described above, the first movable members provided on the peripheral portions of the outer movable plate 3 and the inner movable plate 4
The movable part 5 of the semiconductor substrate 2 is controlled by controlling the currents flowing through the drive coil 8 and the second drive coil 9, respectively.
Can be rotated at an arbitrary angle in the directions of two orthogonal axes. Therefore, the movable portion 5 can be freely swung in the two-dimensional direction by alternately flowing the current in the opposite direction at regular intervals.

[0007]

However, the planar structure is such that the pair of static magnetic field generating means 10a and 10b are arranged so as to sandwich the semiconductor substrate 2 in one diagonal direction of the movable portion 5. In the electromagnetic electromagnetic actuator 1, the pair of static magnetic field generating means 10a and 10b are
They were arranged at a predetermined distance l ₁ . here,
Since the magnetic flux density of the magnetic field is inversely proportional to the square of the distance, when the distance l ₁ between the pair of static magnetic field generating means 10a and 10b becomes large, the magnetic field H ₀ between them becomes small, and accordingly the magnetic field H ₀ becomes a vector. The decomposed lateral component magnetic field H ₁ and vertical component magnetic field H _{2 become} smaller. In such a case, the above (1)
In order to secure the Lorentz force shown in the formula, the magnetic field H
_It is necessary to flow a current corresponding to the decrease of ₀ , and at that time, there is a problem that power consumption when swinging the movable portion 5 increases.

Therefore, the present invention addresses such a problem and improves the magnetic force applied to the drive coil of the movable portion by the magnetic field generated by the pair of magnetic field generating means. An object of the present invention is to provide a planar type electromagnetic actuator capable of reducing power consumption when the unit swings.

[0009]

In order to achieve the above object, a planar type electromagnetic actuator according to the present invention comprises a semiconductor substrate having a movable portion composed of a frame-shaped outer movable plate and an inner movable plate disposed inside thereof. A first torsion bar pivotally supporting the outer movable plate, and a second torsion bar axially orthogonal to the first torsion bar and pivotally supporting the inner movable plate. Are integrally formed, and drive coils are formed on the peripheral portions of the outer movable plate and the inner movable plate, and a pair of magnetic field generating means for applying a magnetic field to the drive coils is formed on the semiconductor substrate in a diagonal direction of the movable portion. In the planar type electromagnetic actuator arranged so as to face each other with the magnetic field generated between the pair of magnetic field generating means, the magnetic force applied to the drive coil of the movable portion is improved.

With this configuration, the magnetic force generated by the pair of magnetic field generating means and applied to the drive coil of the movable portion by the magnetic fields generated by the pair of magnetic field generating means is improved.

Here, the pair of magnetic field generating means are arranged close to each other with respect to the movable portion formed on the semiconductor substrate. As a result, the magnetic force applied to the drive coil of the movable section is improved by the pair of magnetic field generating means arranged close to each other with respect to the movable section formed on the semiconductor substrate.

Further, both ends of the movable portion formed on the semiconductor substrate in the diagonal direction of the movable portion are sandwiched by a pair of rod-shaped magnetic field generating means in a contact state. As a result, the pair of rod-shaped magnetic field generating means sandwiches both ends of the semiconductor substrate in a contact state, and the pair of magnetic field generating means are arranged close to each other.

Further, both ends of the movable portion formed on the semiconductor substrate are cut in a diagonal direction of one of the movable portions, and the both ends are sandwiched by a pair of rod-shaped magnetic field generating means in a contact state. Is. As a result, the pair of rod-shaped magnetic field generating means sandwiches the semiconductor substrate whose both ends have been cut into contact with each other, and the pair of magnetic field generating means are arranged close to each other.

Further, the pair of magnetic field generating means may be formed in a shape that can match the outer shapes of both ends of the semiconductor substrate in the diagonal direction of one of the movable portions formed on the semiconductor substrate. As a result, the volume of the pair of magnetic field generating means formed in a shape that can match the outer shapes of both ends of the semiconductor substrate increases, and the magnetic field generating means sandwiches both end portions of the semiconductor substrate.

Then, both ends of the semiconductor substrate are cut in a diagonal direction of one of the movable parts formed on the semiconductor substrate, and the both ends are sandwiched by the pair of magnetic field generating means. As a result, the volume of the pair of magnetic field generating means formed in a shape suitable for the outer shape of the semiconductor substrate increases, and the magnetic field generating means sandwiches both ends of the semiconductor substrate.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view showing a first embodiment of a planar electromagnetic actuator 1 according to the present invention. This planar type electromagnetic actuator 1
Is a device for freely swinging a movable part 3 formed by using a semiconductor manufacturing technique in two orthogonal directions using an electric signal. The semiconductor substrate 2 and a pair of magnetic field generating means 10a, 10 are used.
b and magnetic path forming means 13.

The semiconductor substrate 2 is formed with a movable portion which can be swung in the directions of two orthogonal axes. The semiconductor substrate 2 includes a silicon layer and has the same structure as the conventional one shown in FIG. That is, a movable portion 5 composed of a frame-shaped outer movable plate 3 and an inner movable plate 4 arranged inside the semiconductor substrate 2, and a first torsion bar pivotally supporting the outer movable plate 3. 6, 6 and the second torsion bars 7, 7 which are axially orthogonal to the first torsion bars 6, 6 and pivotally support the inner movable plate 4 by, for example, anisotropic etching. It is integrally formed by applying. Here, the first torsion bars 6, 6 and the second torsion bars 7, 7 are formed thinner than the thickness of the semiconductor substrate 2 itself, and the movable portion 5 can rotate at a predetermined angle. It is like this. A first drive coil 8 and a second drive coil 9 are provided on the peripheral edge portions of the outer movable plate 3 and the inner movable plate 4, respectively.

A pair of magnetic field generating means 1 is provided in a diagonal direction of one of the outer movable plate 3 and the inner movable plate 4 of the semiconductor substrate 2.
0a and 10b are arranged to face each other. The pair of magnetic field generating means 10a, 10b applies a magnetic field H ₀ to the drive coils 8, 9 of the movable portion 5 formed on the semiconductor substrate 2, and the magnetic pole generating means 10a has the N pole and the magnetic field generating means. It is composed of a pair of permanent magnets arranged so that the S poles of 10b face each other. Thereby, the magnetic field H ₀ is provided between the magnetic field generating means 10a and the magnetic field generating means 10b with a simple structure.
Will occur. The magnetic field H ₀ obliquely crosses the movable portion 5 of the semiconductor substrate 2.

The pair of magnetic field generating means 10a, 10b
Is fixed to the magnetic path forming means 13 which is arranged so as to surround it. As shown in FIG. 1, the magnetic path forming means 13 forms a path of a magnetic force line that exits from the S pole of the left side magnetic field generating means 10a and enters the N pole of the right side magnetic field generating means 10b so that the magnetic field is in the surroundings. It reduces leakage and is made of a magnetic material such as iron. As a result, the strength of the magnetic field between the pair of magnetic field generating means 10a and 10b is improved.

Here, in the present invention, the planar type electromagnetic actuator 1 includes the pair of magnetic field generating means 1.
The magnetic field H ₀ generated from 0a and 10b improves the magnetic force applied to the drive coils 8 and 9 of the movable part 5. Here, the pair of magnetic field generating means 10a and 10b arranged so as to face each other are arranged close to each other with respect to the movable portion 5 formed on the semiconductor substrate 2.

For example, as shown in FIG. 1, both ends of the movable portion 5 formed on the semiconductor substrate 2 in the diagonal direction of the semiconductor substrate 2 have a pair of rod-shaped magnetic field generating means 10 at both ends.
It is sandwiched by a and 10b in a contact state. At this time, the distance l ₂ between the pair of rod-shaped magnetic field generating means 10a, 10b is closer than the conventional case shown in FIG. 5 (l ₂ <
l ₁ ). Therefore, when the strength of the magnetic field H ₀ acting between the pair of magnetic field generating means 10a and 10b is compared with the conventional case, the magnetic flux density of the magnetic field is inversely proportional to the square of the distance, and therefore (l ₁ / l ₂ ) by a factor of ^two larger. Thereby, the pair of magnetic field generating means 10a,
By 10b, the magnetic force applied to the drive coils 8 and 9 of the movable portion 5 can be improved. Therefore, even if the value of the current flowing through the drive coils 8 and 9 is small, the same Lorentz force (see the formula (1)) as in the conventional case can be ensured, so that when the movable part 5 is swung. Power consumption can be reduced.

FIG. 2 is a plan view showing a second embodiment of the planar type electromagnetic actuator 1 according to the present invention. The planar type electromagnetic actuator 1 according to this embodiment cuts both ends of the movable portion 5 formed on the semiconductor substrate 2 shown in FIG. The magnetic field generating means 10a and 10b sandwich the contact state. At this time, in FIG. 2, the semiconductor substrate whose both ends are cut off is formed in a quadrangle as a whole (see reference numeral 14). The length of the semiconductor substrate 14 is l ₃ (l ₃ <l ₂ ). As a result, the pair of rod-shaped magnetic field generating means 10a, 10
b can be disposed so as to be in contact with each other by a distance l _{3 from} each other with respect to the movable portion 5 formed on the semiconductor substrate 14. Therefore, the strength of the magnetic field H ₀ between the pair of magnetic field generating means 10a and 10b is improved, and the power consumption when the movable portion 5 is swung can be reduced. Since the semiconductor substrate 14 has a square shape, the semiconductor substrate 14 and the pair of rod-shaped magnetic field generating means 10a and 10b can be easily mounted.

FIG. 3 is a plan view showing a third embodiment of the planar electromagnetic actuator 1 according to the present invention. In the planar electromagnetic actuator 1 according to this embodiment, the pair of magnetic field generating means 10a and 10b shown in FIG. 1 are provided on both ends of the movable portion 5 formed on the semiconductor substrate 2 in the diagonal direction. It is formed in a shape (see reference numerals 15a and 15b in FIG. 3) that can fit the outer shape. Then, the pair of magnetic field generating means 15a and 15b are arranged opposite to each other with the both ends of the semiconductor substrate 2 sandwiched therebetween. As a result, the volumes of the pair of magnetic field generating means 15a and 15b are increased, and the magnetic force applied to the drive coils 8 and 9 of the movable portion 5 can be improved. At this time, the semiconductor substrate 2
When a pair of magnetic field generating means 15a and 15b formed in a shape compatible with the above shape are arranged close to the semiconductor substrate 2, the distance between the central portions becomes l ₂ and the outer portion As you go to, the distance between them is gradually narrowing. Thereby, the magnetic field generating means 15a,
The strength of the magnetic field H ₀ between 15b is improved, and the power consumption when the movable portion 5 is swung can be further reduced.

FIG. 4 is a plan view showing a fourth embodiment of the planar electromagnetic actuator 1 according to the present invention. In the planar electromagnetic actuator 1 according to this embodiment, both ends of the semiconductor substrate 2 are cut in the diagonal direction of one of the movable portions 5 formed on the semiconductor substrate 2 shown in FIG. 3 (see reference numeral 16 in FIG. 4). , A pair of magnetic field generating means 17 whose both ends are formed in a shape that can fit the outer shape of the semiconductor substrate 16.
It is sandwiched between a and 17b. As a result, the volume of the pair of magnetic field generating means 17a, 17b is increased, and the magnetic force applied to the drive coils 8, 9 of the movable part 5 can be improved. At this time, the pair of magnetic field generating means 17
When the semiconductor substrate 16 whose both ends are cut by a and 17b are arranged opposite to each other, the center-to-center distance becomes a distance l ₃ (l ₃ <l ₂ ), and the distance between them becomes closer to the outer side. It is gradually narrowing. As a result, the strength of the magnetic field H ₀ between the magnetic field generating means 17a and 17b is further improved, and the power consumption when the movable portion 5 is swung can be further reduced.

[0025]

Since the present invention is constructed as described above,
According to the first aspect of the invention, the pair of magnetic field generating means for applying a magnetic field to the drive coil of the movable portion formed on the semiconductor substrate causes the magnetic field generated by the pair of magnetic field generating means to the drive coil of the movable portion. The magnetic force applied can be improved. Therefore, even if the value of the current flowing through the drive coil is small, the force acting on the drive coil can be secured, and thus the power consumption when swinging the movable portion can be reduced.

According to the second aspect of the present invention, the pair of magnetic field generating means are arranged close to each other with respect to the movable portion formed on the semiconductor substrate. The magnetic force applied to the drive coil of the movable section can be improved by the pair of magnetic field generating means arranged close to each other with respect to the movable section formed on the substrate. Therefore, the current flowing through the drive coil formed on the semiconductor substrate can be reduced, and the power consumption when swinging the movable portion can be reduced.

According to the third aspect of the present invention, both ends of the movable portion formed on the semiconductor substrate in the diagonal direction are in contact with each other by a pair of rod-shaped magnetic field generating means. Since the pair of rod-shaped magnetic field generating means sandwiches both end portions of the semiconductor substrate in a contact state, the pair of magnetic field generating means can be arranged close to each other. Therefore, the strength of the magnetic field applied to the drive coil of the movable part can be improved, and the power consumption when swinging the movable part can be reduced. Moreover, mounting of the semiconductor substrate can be facilitated.

Further, according to the invention of claim 4, both end portions of the movable portion formed on the semiconductor substrate are cut in a diagonal direction of the movable portion, and the both end portions are cut into a pair of rod-shaped magnetic fields. Since the pair of rod-shaped magnetic field generating means sandwiches the semiconductor substrate whose both ends are cut into contact with each other, the pair of magnetic field generating means sandwiches the pair of magnetic field generating means from each other. Can be placed close together. Therefore, the strength of the magnetic field applied to the drive coil of the movable part can be improved, and the power consumption when swinging the movable part can be reduced.

According to the invention of claim 5, the pair of magnetic field generating means are adapted to the outer shapes of both ends of the semiconductor substrate in one diagonal direction of the movable part formed on the semiconductor substrate. By forming the obtained shape, the volume of the pair of magnetic field generating means formed in a shape that can conform to the outer shapes of both ends of the semiconductor substrate is increased, and the both end portions of the semiconductor substrate are sandwiched by the magnetic field generating means. . Therefore, the strength of the magnetic field applied to the drive coil of the movable part can be improved, and the power consumption when swinging the movable part can be reduced.

According to the sixth aspect of the invention, both ends of the semiconductor substrate are cut in a diagonal direction of one of the movable parts formed on the semiconductor substrate, and the both ends generate the pair of magnetic fields. When sandwiched by the means, the volume of the pair of magnetic field generating means formed in a shape that can fit the outer shape of the semiconductor substrate increases, and the magnetic field generating means sandwiches both ends of the semiconductor substrate. Therefore, the strength of the magnetic field applied to the drive coil of the movable portion can be improved,
It is possible to reduce power consumption when swinging the movable portion.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of a planar electromagnetic actuator according to the present invention.

FIG. 2 is a plan view showing a second embodiment of the electromagnetic actuator.

FIG. 3 is a plan view showing a third embodiment of the electromagnetic actuator.

FIG. 4 is a plan view showing a fourth embodiment of the electromagnetic actuator.

FIG. 5 is a perspective view illustrating a conventional planar electromagnetic actuator.

FIG. 6 is an explanatory diagram showing the operating principle of the electromagnetic actuator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Planar electromagnetic actuators 2, 14, 16 ... Semiconductor substrate 3 ... Outer movable plate 4 ... Inner movable plate 5 ... Movable parts 8, 9 ... Drive coils 10, 15, 17 ... Magnetic field generating means 13 ... Magnetic path forming means H ₀ ... magnetic field l ₂ , l ₃ ... distance between a pair of magnetic field generating means

Claims (6)

[Claims] 1. A semiconductor substrate having a movable portion composed of a frame-shaped outer movable plate and an inner movable plate disposed inside thereof, and a first torsion bar pivotally supporting the outer movable plate.
A second torsion bar, which has an axial direction orthogonal to the first torsion bar and pivotally supports the inner movable plate, is integrally formed, and a drive coil is provided on each peripheral portion of the outer movable plate and the inner movable plate. And a pair of magnetic field generating means for applying a magnetic field to the drive coil are opposed to each other with the semiconductor substrate sandwiched in the diagonal direction of one of the movable parts. A planar type electromagnetic actuator characterized in that a magnetic field generated from the magnetic field enhances a magnetic force applied to the drive coil of the movable part. 2. The planar electromagnetic actuator according to claim 1, wherein the pair of magnetic field generating means are arranged close to each other with respect to a movable portion formed on the semiconductor substrate. 3. A pair of rod-shaped magnetic field generating means sandwiching both ends of the movable portion in a contact state in a diagonal direction of one of the movable portions formed on the semiconductor substrate. 2. The planar electromagnetic actuator according to 2. 4. The semiconductor substrate is cut at both ends thereof in a diagonal direction of one of the movable parts formed on the semiconductor substrate, and the both ends are sandwiched by a pair of rod-shaped magnetic field generating means in a contact state. The planar type electromagnetic actuator according to claim 2. 5. The pair of magnetic field generating means is formed in a shape that can be fitted to the outer shapes of both ends of the semiconductor substrate in the diagonal direction of one of the movable portions formed on the semiconductor substrate. The planar electromagnetic actuator according to claim 1. 6. A semiconductor device according to claim 1, wherein both end portions of the semiconductor substrate are cut in a diagonal direction of one of the movable portions formed on the semiconductor substrate, and the both end portions are sandwiched by the pair of magnetic field generating means. Item 5. The planar electromagnetic actuator according to Item 5.