JP2003029176A - Optical switch, manufacturing method therefor, and optical switch system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical switch which enables a mirror to be fixedly held in a light reflection position with a simple structure and does not need energy for fixedly holding it. SOLUTION: An optical switch 1 is provided with a mirror 2 on the upper face of a substrate 4 and is provided with a core 5, which pierces their center parts and is made of a ferromagnetic body. The substrate 4 is supported by a leaf spring 6, and a pair of permanent magnets 7 and 8 are arranged above and below the substrate 4, and electromagnetic coils 3 are formed on surfaces facing each other of permanent magnets 7 and 8. When the core 5 is attracted to the upper permanent magnet 8, the optical switch is turned on, and the mirror 2 reflects a signal light. When a current is made to flow to the upper electromagnetic coil 3 for making an electromagnet repelling the upper permanent magnet 8 of the core 5 in the switch-on state, the core 5 is separated from the upper permanent magnet 8 and is moved to the lower permanent magnet 7, to go into turn off position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical switch having a mirror, a method for manufacturing the same, and an optical switch system using the optical switch.

[0002]

2. Description of the Related Art In recent years, the amount of communication information transmitted through optical fiber networks has increased explosively due to the spread of the Internet. In order to cope with this increase in transmission amount, a wavelength division multiplexing (WDM) transmission technique in which signals of different wavelengths are superimposed on one optical fiber for transmission and reception is becoming more and more important.

By the way, the WDM system currently introduced is mainly a point-to-point system in which communication between two points is combined by wavelength division multiplexing using an optical multiplexer / demultiplexer, but the demand for communication increases. In order to cover the situation, a method of branching or inserting a specific fixed wavelength at a relay station is also introduced in urban areas. Furthermore, in order to flexibly respond to communication demands that change from moment to moment and breakdowns of communication lines, a system for branching or inserting an arbitrary wavelength using an optical switch is under study. As this optical switch system, a small-scale system with 1 input and 2 outputs (1 × 2) can be used.
0x1000) is required, but at present, only a small-scale optical switch system is put into practical use, and a large-scale optical switch system is not put into practical use.

The optical switch used in the above-mentioned small-scale optical switch system is of a system in which an optical fiber, an optical waveguide or a mirror is mechanically moved. Among them, the movable optical fiber type includes a type that moves an optical fiber by magnetism or thermal expansion. Further, there is a movable waveguide type in which an optical waveguide is mechanically moved, and a 2 × 2 type optical switch system or the like is realized by using such an optical switch. However, these optical switches have a slow response and are difficult to be structurally miniaturized, and therefore are not suitable for a large-scale optical switch system with multiple inputs and multiple outputs.

On the other hand, as a movable mirror type optical switch, for example, "An Electromagnetic MEMS 2 * 2 Fiber Optic Byp
ass Switch ", International Conference on Solid-Stat
There is an optical switch described in e Sensors and Actuators, 1997, pp89-92. This optical switch is of a type in which an optical fiber is fixed in an X-shaped groove formed in silicon, and a silicon micromirror is taken in and out at the intersection thereof by high speed switching. Since only a small-scale optical switch system is currently realized because it does not require a large amount of force to move in and out, it is considered that increasing the scale is relatively easy.

The above optical switch has a structure in which a silicon plate on which a micromirror is mounted is supported by a beam of the silicon plate, a copper coil is provided on the back side of the micromirror, and a rare earth magnet is provided below. It has been placed. When the micromirror is inserted in the optical path, that is, when the switch is turned on, a current is passed through the copper coil to generate a magnetic field. Then, the magnetic field causes a repulsive force between the lower magnet and the micro mirror to move upward, enter the optical path, and reflect light. When the current flow is stopped, the micromirror goes down and out of the optical path, turning the switch off.

[0007]

However, in the above movable mirror type optical switch, when the micromirror enters the optical path and reflects light, the position where the elastic force of the beam and the repulsive force due to gravity and the magnetic field are balanced. Since there is no mechanism for fixing and holding this position only because the micromirror is placed in the position, the position of the micromirror changes when external vibration is applied, and the signal light is not output to the predetermined optical fiber. Further, in order to keep the micromirror in the optical path and reflect the light, it is necessary to keep the current flowing through the copper coil, so that power consumption becomes large in such an optical switch system. further,
When an abnormality such as a power failure occurs, the micromirror returns to the initial position, and the reliability is low.

The present invention has been made in view of the above circumstances, and an object thereof is to enable a mirror to be fixedly held at a light reflection position with a simple structure, and energy for this fixed holding is unnecessary. To provide a simple optical switch.

[0009]

In order to achieve the above object, the invention of claim 1 is directed to an optical switch which operates so that a mirror for reflecting signal light enters and retracts into a signal light path.

A pair of permanent magnets, which are arranged opposite to each other and each have an electromagnetic coil, and a core, which is disposed between the pair of permanent magnets, is made of a ferromagnetic material and constitutes an electromagnet together with the electromagnetic coil. A substrate having the mirror and an elastic member that supports the substrate together with the mirror so that the core can be moved into and out of the signal optical path, and the electromagnet has the core attracted to one of the permanent magnets. When the electromagnetic coil is energized, the core is moved from the one permanent magnet to the other permanent magnet and is attracted to the other permanent magnet. When one of the cores is attracted to one of the two, the mirror enters the signal optical path, while when the core is attracted to the other, the mirror is retracted from the signal optical path. It is assumed to be configured.

According to the first aspect of the invention, the core, which is a ferromagnetic material, holds the substrate in a fixed state by being attracted to one of the pair of permanent magnets, so that the mirror enters the signal light path. Both the state where the signal light is reflected and the state where the mirror retracts from the signal light path and the signal light goes straight are maintained. At this time, it is not necessary to apply energy for fixing and holding the substrate. Further, when releasing the attraction from the state where the core is attracted to one permanent magnet and moving it toward the other permanent magnet, a current is passed through the electromagnetic coil to repel the attracted permanent magnet. Creates such a magnetic field in the core. During this movement, the substrate is supported by the elastic member and always guided to the same entry position and retreat position.

Next, the invention of claim 2 is directed to an optical switch which operates so that a mirror for reflecting signal light enters and retracts into a signal light path.

A pair of permanent magnets, which are arranged to face each other and each have an electromagnet, and a substrate, which is disposed between the pair of permanent magnets, has a fixed holding portion made of a ferromagnetic material and the mirror. An elastic member that supports the substrate together with the mirror so as to enter and retract into the signal optical path, and the electromagnet is configured so that when the fixed holding portion is attracted to one of the electromagnets, the other When the electromagnet is energized, the fixed holding portion moves from the one electromagnet to the other electromagnet and is attracted to the other electromagnet, and the fixed holding portion is attracted to one of the two electromagnets. While the mirror is entering the signal light path, the fixed holding portion is attracted to the other,
It is assumed that the mirror is configured to be retracted from the signal light path.

According to the structure of the second aspect of the present invention, since the fixed holding portion, which is a ferromagnetic material, holds the substrate by being attracted to one of the pair of electromagnets, the mirror enters the signal optical path. Thus, both the state of reflecting the signal light and the state of the mirror retracting from the signal light path and the signal light traveling straight are maintained. At this time, since the core of the electromagnet is magnetized by the permanent magnet, it is not necessary to apply energy for fixing and holding the substrate. Further, when the fixed holding portion is moved from the state in which it is attracted to one electromagnet to the other electromagnet to attract it, a current is passed through the other electromagnet to attract more than the attraction force of the one electromagnet. Generate force. At the time of this movement, the substrate is supported by the elastic member and is always guided to the same entry position and retreat position as in the first aspect.

Next, the invention of claim 3 is directed to a method of manufacturing an optical switch according to claim 1.

Then, a step of etching the silicon plate to integrally form the mirror, the substrate and the elastic member, a step of forming the core on the substrate by plating, and a step of forming the electromagnetic coil at least by plating. And.

The invention of claim 4 is directed to a method of manufacturing an optical switch according to claim 2.

Then, the step of etching the silicon plate to integrally form the mirror, the substrate and the elastic member, the step of forming the fixed holding portion on the substrate by plating, and the electromagnetic coil of the electromagnet at least plated. And the step of forming by.

According to the configurations of claims 3 and 4,
Since the process of manufacturing the substrate portion of the optical switch by sequentially etching and plating the silicon plate and the process of manufacturing the electromagnetic coil or electromagnet provided on the permanent magnet by plating are separately performed, the manufacturing can be performed in a short time. Also,
In each process, each step is simple, and the positional accuracy of each part can be easily increased. In order to increase the magnetic field generated when a current is applied, the electromagnetic coil of the electromagnet is preferably stacked in a plurality of stages by combining plating and coating / patterning of an insulator.

Next, a fifth aspect of the present invention is directed to an optical switch system in which a plurality of optical switches according to the first or second aspect are arranged to switch a plurality of signal light emission locations.

The plurality of optical switches share a pair of permanent magnets.

According to the fifth aspect of the invention, since the plurality of optical switches share the pair of permanent magnets, the structure is simple, the manufacturing process is simple, and the cost is reduced.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

-Embodiment 1- FIG. 1 is a schematic view of an optical switch 1 according to Embodiment 1 as viewed from diagonally above. In this optical switch 1, a substrate 4 having a mirror 2 is movably supported by a leaf spring (elastic member) 6, and a pair of permanent magnets 7 and 8 are arranged above and below the substrate 4 so as to face each other. Is to have.

The optical switch 1 will be described in detail below.

A silicon substrate 4 is arranged in the central portion of the optical switch 1, and a mirror 2 also made of silicon is provided on the upper surface thereof. The mirror 2 is in the shape of an octagonal prism, and this one cylindrical surface serves as a signal light reflecting surface 10. As shown in FIG. 2, through holes 2a and 4a are formed vertically through the mirror 2 and the central portion of the substrate 4, respectively, and the through holes 2a and 4a communicate with each other. A core 5 made of permalloy, which is a ferromagnetic material, is formed so as to fill the communicating through holes 2a and 4a and project to the upper side of the mirror 2 and the lower side of the substrate 4.

Although the leaf spring 6 projects from the outer frame 9, both the outer frame 9 and the leaf spring 6 are made of silicon and are integrally formed with the substrate 4. This leaf spring 6 has an outer frame 9 that faces the leaf spring 6.
And the substrate 4 are connected in a zigzag spring shape parallel to them. The zigzag spring shape is used in this manner in order to reduce the amount of strain per unit length of the leaf spring 6 at the time of deformation by increasing the length of the leaf spring 6.
Further, in order to surely support the substrate 4, it is preferable to support one substrate 4 by two or more leaf springs 6. It is particularly preferable to form the four leaf springs 6 on one substrate 4 because the substrate 4 can be supported more reliably.

Electromagnetic coils 3 are provided on the surfaces of the pair of permanent magnets 7, 8 arranged above and below the substrate 4 on the substrate 4 side via a coil base 11, respectively. That is, both permanent magnets 7 and 8 each have an electromagnetic coil. A through hole 20 having a diameter larger than the outer diameter of the core 5 is provided at the center of the coil base 11, and the electromagnetic coil 3 is formed around the through hole 20. The electromagnetic coil 3 is combined with the core 5 to form an electromagnet. However, in order to increase the generated magnetic field, the core 5 is
When attracted to the permanent magnets 7 and 8, the electromagnetic coil 3
There is a positional relationship that goes inside. Also, core 5
Enters the through hole of the coil base 11, contacts the permanent magnets 7, 8 and is attracted.

Next, a method of manufacturing the optical switch will be described.

FIG. 3 is a cross-sectional view showing the process of manufacturing the substrate 4 and its related parts by silicon micromachining and plating. FIG. 3A is a sectional view of the silicon plate 12 having a three-layer structure.
Has Si layers 14a and 14b laminated on both sides of the SiO ₂ layer 13. The upper Si layer 14a in the figure is the lower S layer.
It is formed thicker than the i layer 14b, and is a portion that forms the mirror 2. The lower Si layer 14b is a portion forming the substrate 4, the outer frame 9, and the leaf spring 6. This silicon plate 1
The two Si layers 14a and 14b and the SiO ₂ layer 13 are subjected to thermal oxide film formation, patterning and etching to form the substrate 4, the mirror 2, the outer frame 9 and the leaf spring 6 (see FIG. 3B. )). Through holes 15 are formed in the substrate 4 and the mirror 2 so as to communicate with each other. Then, in order to form the core 5 in the next step, the electrode 16 is formed of the chromium thin film by the sputter deposition method around the through hole 15 on the lower surface of the substrate 4 (FIG. 3).
(C)).

Permalloy, which is a ferromagnetic material, is deposited in the through hole 15 by electrolytic plating using the electrode 16 described above.
The core 5 is formed (FIG. 3 (d)). In this way, the substrate 4 and its related parts are completed. At this time, it is preferable to make the diameter of the core 5 larger than the diameter of the through-hole of the substrate 4 so that the core 5 and the substrate 4 can integrally move when the optical switch described later is driven.

4A to 4C are views showing the manufacturing process of the electromagnetic coil 3 in order of cross section. The electromagnetic coil 3 is formed on the upper surface of the coil base 11 which is a silicon plate.
In the coil base 11, a silicon oxide plate is formed with a thermal oxide film, patterned, and etched to form a through hole 20 into which the core 5 is inserted in the central portion (FIG. 4B). next,
Patterning is performed by applying a photosensitive polyimide, exposing and developing, and an insulating film 17 for a coil pattern having a recess 18 on the surface is formed around the through hole 20 (FIG. 4).
(C)). Copper plating is applied to the recess 18 of the insulating film 17 to form a single-layer copper coil 19 (FIG. 4D). The formation of the insulating film 17 and the copper plating are repeated to form the electromagnetic coil 3 in which a plurality of single-layer copper coils 19 are laminated (FIG. 4E). Although not shown in the figure, at this time, the current supply wiring to the electromagnetic coil 3 is also simultaneously connected to the coil base 11.
It is preferable to form it.

Next, the lower surface of the coil base 11 is bonded to the permanent magnets 7 and 8, respectively, so that the electromagnetic coil 3 formed as described above is installed on the permanent magnets 7 and 8. Then, the permanent magnets 7 and 8 are arranged so that the surfaces to which the coil bases 11 are bonded face each other, and the substrate 4 and its related parts are arranged between them to complete the optical switch 1.

Next, the drive mechanism of the optical switch 1 will be described. The optical switch 1 has a position (hereinafter, referred to as an ON position) in which the mirror 2 enters a signal light path for reflecting the signal light,
Position retracted from signal light path (hereinafter referred to as OFF position)
The optical switch 1 is driven by moving a current through the electromagnetic coil 3 to make the core 5 an electromagnet. Here, the principle of the electromagnet is shown in FIG. When a current is applied to the electromagnetic coil 22 wound around the rod-shaped ferromagnetic core 21, the core 21 is magnetized and becomes an electromagnet. In the figure, since a current is applied to the electromagnetic coil 22 counterclockwise when viewed from above, the upper side of the core 21 is the N pole and the lower side is the S pole. In FIG. 5, 23
Are magnetic lines of force.

A driving method utilizing such a function of the electromagnet is schematically shown in a cross section in FIG. In FIG. 6, the optical switch 1 moves from the ON position to the OFF position in sequence. In FIG. 6, the coil base 11
Is not shown. The driving method shown in FIG. 6 utilizes both the repulsive force between the core 5 that is an electromagnet and the upper permanent magnet 8 and the attraction force between the lower permanent magnet 7. The upper and lower permanent magnets 7 and 8 have different poles facing each other. FIG. 6A shows a state in which the optical switch 1 is in the ON position. In this state, since the core 5 is a ferromagnetic body, it is attracted to the upper permanent magnet 8 by magnetic force, and no current flows in the upper and lower electromagnetic coils 3a and 3b. Mirror 2, substrate 4 together with core 5
Is also fixed to the upper side, and the leaf spring 6 is bent upward.

Next, a current is passed through the upper electromagnetic coil 3a for driving (FIG. 6 (b)). The current is supplied by a wire (not shown) formed on the coil base. 25, 2
Reference numeral 6 is a symbol indicating the direction of the current, 25 is the direction from the back side to the front side of the paper, and 26 is the direction from the front side to the back side of the paper. When viewed from above, this current flows around the core 5 in the counterclockwise direction.
The top is the N pole and the bottom is the S pole. Therefore, since the N poles come into contact with the attracted upper permanent magnet 8, repulsive force is generated here, the attraction is released, and the core 5 separates from the upper permanent magnet 8. Even after being separated, the core 5 is still repulsed by the repulsive force and the restoring force of the bent leaf spring 6.
Is driven downwards.

Then, the core 5 has the permanent magnets 7 from the top to the bottom.
The current supply to the electromagnetic coil 3a on the upper side is stopped on the way to, and this time, the electric current in the opposite direction to the electromagnetic coil 3b on the lower side is made to flow (FIG. 6 (c)). Then, the lower side of the core 5 becomes an N pole and attracts the S pole of the lower permanent magnet 7 to each other, so that the core 5 is driven downward. When the core 5 is attracted to the lower permanent magnet 7 (OFF position), the current continues to be attracted even if the current is not passed, so the current supply is stopped (FIG. 6).
(D)). The current supply to the lower electromagnetic coil 3b may be stopped before the core 5 is attracted to the lower permanent magnet 7. To drive from the OFF position to the ON position,
In the state of FIG. 6 (d), the electromagnetic coil 3b on the lower side is
When the current flowing in the opposite direction to that shown in (c) is passed and the core 5 moves away from the lower permanent magnet 7 toward the upper permanent magnet 8, the upper electromagnetic coil 3 a is moved to the upper electromagnetic coil 3 a. (B)
It suffices to pass a current in the opposite direction to that shown in.

As described above, in order to move the optical switch 1 from the ON position to the OFF position, or vice versa, from the OFF position to the ON position, it is necessary to pass a current through the electromagnetic coils 3a and 3b. In order to maintain the position of the optical switch 1 in the ON position or the OFF position, it is not necessary to pass a current. That is, power is not consumed to hold the position of the optical switch 1, and the position of the optical switch 1 does not change even if power is cut off due to a power failure or the like while the optical switch 1 is operating, and the reliability is high.

Next, a schematic diagram of a 2-input 2-output optical switch system using four optical switches 1 of the present embodiment is shown in FIG.
Shown in. In FIG. 7, the pair of permanent magnets 7 and 8 are shared by the four optical switches 1 (1a, 1b, 1c, and 1d), and the upper permanent magnet 8 is removed and viewed from above. is there. These four optical switches 1 (1a, 1b, 1
c, 1d), each outer frame 9 is connected and extends to the outside, and each optical switch 1 is arranged in each hole 37 provided in the silicon plate that is the outer frame 9. ing. The first output optical fiber 31, the second output optical fiber 32, the first input optical fiber 33, and the second input optical fiber 34 for input and output are each made of silicon in a portion extending to the outside of the outer frame 9. It is fixed to each of the four V grooves 35.

In FIG. 7A, the optical switch 1 at the upper left of the drawing is shown.
a and the lower right optical switch 1d are attracted and fixed to the lower permanent magnet 7 and are in the OFF position, and the upper right optical switch 1b and the lower left optical switch 1c are attached to the upper permanent magnet 8. It is fixed by suction and is in the ON position. Therefore, the light emitted from the first outgoing optical fiber 31 is reflected by the optical switch 1c at the lower left to be reflected by the first incoming optical fiber 33.
to go into. The light emitted from the second emission optical fiber 32 passes above the lower right optical switch 1d, and passes through the upper right optical switch 1b.
Is reflected by and enters the second incident optical fiber 34.

In FIG. 7B, four optical switches 1a,
The ON and OFF positions of 1b, 1c, and 1d are shown in FIG.
Since it is the reverse of (a), the first outgoing optical fiber 3
The light emitted from 1 passes above the optical switch 1c at the lower left,
It is reflected by the upper left optical switch 1a and enters the second incident optical fiber 34. The light emitted from the second outgoing optical fiber 32 is reflected by the lower right optical switch 1d and enters the first incoming optical fiber 33.

From the above description, the optical switch 1 according to the present embodiment has a pair of permanent magnets in which the core 5 made of a ferromagnetic material formed on the substrate 4 having the mirror 2 is placed above and below the substrate 4. By adsorbing to one of 7 and 8, the ON position and the OFF position of the optical switch 1 are fixedly held, so that even if vibration is applied from the outside, the position does not change and the operation is stable. Such switching between the ON position and the OFF position can be performed by passing a current through the electromagnetic coil 3 provided on the permanent magnets 7 and 8, so that the switch operation can be easily performed. Further, since the optical switch 1 is fixedly held in the ON position or the OFF position, no electric power is consumed, so that the optical switch 1 can be used at low cost, and even if the power is shut down due to an abnormal situation, the optical switch 1 is in the ON position at that time. Or OF
Since the F position does not change, the reliability is high. Further, the manufacturing of the optical switch 1 is performed by etching the silicon plate, then forming the core 5 by plating, and forming the electromagnetic coil 3 by plating in another step, so that the steps are simple and easy, and Can be formed with high positional accuracy.

-Embodiment 2- FIG. 8 is a schematic view of the optical switch 1 according to Embodiment 2 as seen from diagonally above. The present embodiment is substantially the same as the first embodiment except that the permanent magnets 7 and 8 are provided with the electromagnets 41 instead of the electromagnetic coils, and therefore only the portions different from the first embodiment will be described.

In the present embodiment, the fixed holding portion 42 having the same material and shape as the core 5 of the first embodiment is formed on the substrate 4, and the fixed holding portion 42 is the core of the electromagnet as in the first embodiment. Instead, the magnets are attracted to the upper and lower electromagnets 41, respectively, whereby the optical switch 1 is fixedly held in the ON position and the OFF position. If the diameter of the fixed holding portion 42 is made larger than the diameter of the through hole 4a of the substrate 4, the fixed holding portion 42 is driven when the optical switch 1 described later is driven.
This is preferable because the substrate 4 and the substrate 4 can move integrally assuredly.

FIG. 9 schematically shows the structure of the electromagnet 41 (the electromagnet 41 shown in FIG. 9 is provided on the lower permanent magnet 7, but is provided on the upper permanent magnet 8). The thing is the same as that provided on the lower permanent magnet 7 except that the vertical relationship is reversed). The electromagnet 41 has a comb-teeth shape (three teeth) and has a lower core connecting portion 62.
The three cores 44, 45a, 45b are connected by. The electromagnetic coil 3 is provided only in the central core 44 of these, and a magnetic field is generated by passing a current through the electromagnetic coil 3. In the figure, since the current flows counterclockwise as viewed from above, the upper side of the central core 44 becomes the N pole, and the upper sides of the cores 45a, 45b at the first and second ends become S poles.
It is a pole. With such a comb-like shape, the generated magnetic flux is not leaked to the outside, so that the fixed holding portion 42 of the ferromagnetic material arranged above the central core 44 can be efficiently attracted.

The actual electromagnet 41 of this embodiment is shown in FIG.
As shown in FIG. 4, the core connecting portion 62 is a rectangular parallelepiped and has a bottom surface. The first and second end cores 45a and 45b form a pair of side surfaces facing each other, and a central core 44 narrower than the side surfaces is provided vertically from the center of the bottom surface to the upper surface of the rectangular parallelepiped. The electromagnetic coil 3 is provided around the central core 44, and the remaining portion of the rectangular parallelepiped is filled with the insulator 61.

FIG. 10 shows the electromagnetic coil 3 of the electromagnet 41.
FIG. 10 is a diagram showing the configuration of FIG. 10 (note that FIG. 10 shows a state in which the central core 44 is horizontal). As shown in FIG. 10A, the electromagnetic coil 3 has a rectangular shape for one round corresponding to the cross-sectional shape of the central core 44.
As shown in FIG. 10B, this one round is divided into four parts on each side. In order to form such an electromagnetic coil 3, first, a rectangular bottom portion 4 having a rectangular shape is formed.
A plurality of 6 are arranged in parallel and formed. And the bottom part 4
Cylindrical side portions 4 that are substantially vertically opposed to both ends of 6
7 are formed in a plural number, and a plurality of strip-shaped upper side portions 48 are formed so as to connect the upper ends of the opposite side side portions 47 to each other.

Next, a method of manufacturing the above electromagnet 41 will be described. FIG. 11 is a diagram sequentially showing the first half of the process of manufacturing the electromagnet 41 in cross section. 11 (a)-
(D) corresponds to the AA cross section of FIG. 15, and corresponds to a state in which the first end core 45a is located on the lower side and the second end core 45b is located on the upper side.

First, the permalloy plate 50 which is a ferromagnetic material.
Is prepared (FIG. 11A), and a photosensitive polyimide insulating film 51 is formed on the upper surface thereof (FIG. 11B). The permalloy plate 50 serves as the core 45a at the first end of the electromagnet 41, and the insulating film 51 serves to insulate the core 45a at the first end from the electromagnetic coil 3 and becomes a part of the insulator 61. .
The left end portion of the permalloy plate 50 is not coated with a photosensitive polyimide in order to connect the cores 45a and 45b at both ends and the core 44 at the center later.

Then, the photosensitive polyimide is applied again,
Exposure and development are performed to form a pattern so that the portion where the coil pattern is to be formed is the recess 49 (FIG. 11).
(C)). A bottom portion 46 is formed in the recess 49 by electrolytic copper plating (FIG. 11 (d)). This FIG. 11 (d)
FIG. 13 is a view on arrow D in this state. In the following, a cross section (BB cross section) connecting the upper end portions of the respective bottom side portions 46 in FIG. 13 and a cross section (C along the length direction of one bottom side portion 46).
(C cross section) is also shown as appropriate. Next, in order to insulate the central core 44 from the electromagnetic coil 3, a photosensitive polyimide insulating film 53 is formed.
Is formed by applying, exposing, and developing, and further, a photosensitive polyimide insulating film 54 for forming the side portion 47 and the central core 44 of the electromagnetic coil 3 is applied thereon, and a pattern is formed by exposing and developing. (FIG. 11E). As a result, the recess 55 for forming the side portion 47 is formed, and the recess 56 for forming the central core 44 is formed.

FIG. 12 is a cross-sectional view showing the latter half of the process of manufacturing the electromagnet 41 following FIG. 11 in order. Figure 1
After 1 (e), the side portions 47 of the electromagnetic coil 3 and the central core 44 are formed in the recesses 55 and 56 by electrolytic plating (FIG. 12A). At this time, the side portion 47 is made of copper, and the central core 44 is made of permalloy. In addition, in the BB cross section and the CC cross section, the bottom portion 46 and the side portion 47 are not shown as a boundary between them but are shown integrally.

Next, a photosensitive polyimide insulating film 57 is formed by coating, exposing and developing for insulating the central core 44 from the electromagnetic coil 3, and the upper side portion 48 of the electromagnetic coil 3 is further formed thereon. A photosensitive polyimide insulating film 58 for forming the above is applied, exposed and developed to form a pattern, and then copper electroplating is performed to form the upper side portion 48 of the electromagnetic coil 3 (FIG. 12B). In addition, BB
In the cross section and the CC cross section, the side portion 47 and the upper side portion 48 do not show the boundary between the two and are shown integrally.

Then, the second end core 4 to be formed next is formed.
Insulation film 59 of photosensitive polyimide is formed on all of these upper surfaces by coating in order to insulate it from 5b (FIG. 12).
(C)). Then, the second end core 45b is formed on the upper surface of the insulating film 59, and the connecting portion 62 of the three cores 50, 44, 45b is formed by permalloy electrolytic plating on the left end side of the laminated portion formed so far. With electromagnet 4
1 is completed (FIG. 12 (d)).

Next, a method of driving the optical switch of this embodiment will be described.

In FIG. 14, the optical switch 1 moves from the ON position to the O position.
The section from the OFF position to the returning to the ON position is shown in cross section in order. This method is a driving method utilizing the attractive force between the electromagnet 41 and the fixed holding portion 42, and the upper and lower permanent magnets 7 and 8 face different poles. FIG. 14A shows a state in which the optical switch 1 is in the ON position. In this state, no current flows in the upper and lower electromagnetic coils 3a and 3b, but the cores 44a and 44b of the electromagnet are ferromagnetic bodies,
It is magnetized because it is in contact with the upper and lower permanent magnets 7 and 8. Therefore, the fixed holding portion 42, which is a ferromagnetic material, is attracted to the upper electromagnet 41a by magnetic force. Fixed holding part 4
Along with 2, the mirror 2 and the substrate 4 are also fixed to the upper side, and the leaf spring 6 is bent upward.

Next, a current is passed through the lower electromagnetic coil 3b for driving (FIG. 14 (b)). The electric current is supplied by a wiring (not shown) formed on the lower permanent magnet 7.
Due to the supply of this current, the upper side of the central core 44b of the lower electromagnet 41b becomes an N pole, and a strong magnetic field is generated, so that the attractive force of the lower electromagnet 41b is generated between the fixed holding portion 42 and the upper electromagnet 41a. Fixed holding part 4
2 moves away from the upper electromagnet 41a and moves downward. At this time, the restoring force of the leaf spring 6 also cooperates with the downward driving. In this way, if the fixed holding unit 42 moves to the lower electromagnet 41b and is attracted, the current continues to be attracted without passing the current, so that the current supply is stopped (FIG. 14C). This state is the OFF position of the optical switch 1. The current supply may be stopped immediately before the fixed holding portion 42 is attracted to the lower electromagnet 41b.

Next, the optical switch 1 is turned on from the off position.
In order to set the position, a current is passed through the upper electromagnetic coil 3a, and the lower side of the central core 44a of the upper electromagnet 41a is moved to S
A strong magnetic field is generated as a pole (FIG. 14 (d)). Then, a phenomenon similar to that described with reference to FIG. 14B occurs, the optical switch 1 is driven to the upper side, is attracted to the upper electromagnet 41a, and returns to the ON position (FIG. 14E). .

An optical switch system using four optical switches 1 of the present embodiment has the same structure and operates as the optical switch system of the first embodiment.

The optical switch 1 of this embodiment is the same as that of the first embodiment.
It has the same effect as the optical switch of.

The two embodiments described above are examples of the present invention, and the present invention is not limited to these examples. The mirror 2, the substrate 4, the leaf spring 6, the coil base 11 and the like may be made of metal or resin. The shape of the mirror 2 may be a polygonal prism such as a triangular prism or a quadrangular prism, or may be a flat plate shape standing on the substrate 4. The substrate 4 may also have a polygonal shape other than a square or a circular shape. The leaf springs 6 may also protrude from the outer frame 9 so as to extend around the substrate 4 from about a half circumference to one round. Further, even if the leaf springs 6 protrude from the outer frame 9 or stand up from a lower base or the like. Good. Further, the elastic member is not limited to the leaf spring 6. Electromagnetic coil 3
The number of stacked layers, size, shape, etc. are not particularly limited. In the first embodiment, the electromagnetic coil 3 may be directly formed on the surfaces of the permanent magnets 7 and 8. In the second embodiment,
The shape of the electromagnet 41 does not have to be a comb tooth shape, for example,
The simplest shape having one columnar core may be used, or any shape may be used as long as the fixed holding portion 42 can be driven up and down. In addition, in the second embodiment, the electromagnet 4
1 may be directly formed on the surfaces of the permanent magnets 7 and 8, or may be formed on a silicon plate, a metal plate or the like. The substance forming the electromagnetic coil 3 may be any substance as long as it functions as a coil. Core 5,44,
The substance forming 45 and the fixed holding part 42 may be any substance as long as it is a ferromagnetic substance. The shape of the core 5 and the fixed holding portion 42 does not have to be a cylindrical shape, and the formation place does not have to be in the through hole of the mirror 2 and may be separated from the mirror 2.

Also, in the method of manufacturing the optical switch 1, the order of steps may be changed or other steps may be inserted. Moreover, any method may be used for the silicon etching or plating, such as an etching method such as RIE or wet etching, or a plating method such as electrolytic plating or electroless plating.

Further, as for the driving method, in the method shown in FIG. 6 of the first embodiment, the timing of stopping the current is particularly limited after the current is passed through the upper electromagnetic coil 3a and the core 5 is separated from the upper permanent magnet. Alternatively, in FIGS. 6B and 6C, current may be passed through both the upper and lower electromagnetic coils 3a and 3b. The upper and lower permanent magnets 7 and 8 may have the same poles facing each other, and at this time, the directions of the currents flowing through the upper and lower electromagnetic coils 3a and 3b are the same. Also in the driving method of the second embodiment, the timing of supplying / stopping the current is not particularly limited, and the upper and lower permanent magnets 7 and 8 may have the same poles facing each other. The number of optical switches used in the optical switch system is not particularly limited, and the optical switches may be arranged in any manner.

[0063]

The present invention is carried out in the form as described above, and has the following effects.

According to the first aspect of the present invention, the core made of a ferromagnetic material formed on the substrate of the optical switch is attracted to one of the pair of permanent magnets placed above and below the optical switch, thereby causing the mirror to signal. Since the position that has entered the optical path or the position that has retracted is fixedly held, even if vibration is applied, the position does not fluctuate and stable operation is achieved. Further, the movement between the position where the mirror enters the signal light path and the position where it retracts is performed by passing a current through the electromagnetic coil provided in the permanent magnet, so that the switching operation of the optical switch can be easily performed. . Furthermore, since power is not consumed to hold the optical switch fixedly at the position where the mirror has entered the signal optical path or at the retracted position, it can be used at low cost, and
Even if the power is cut off due to an abnormal situation, the position of the optical switch does not change, so the reliability of the optical switch system is high.

According to the second aspect of the invention, the fixed holding portion made of a ferromagnetic material formed on the substrate of the optical switch is provided on one of the electromagnets respectively provided on the pair of permanent magnets placed above and below the optical switch. By adsorbing, the mirror holds the position where the mirror has entered or retracted into the signal optical path, so that even if vibration is applied, the position does not change and the mirror operates stably. Further, the movement between the position where the mirror enters the signal light path and the position where it retracts is performed by passing a current through the electromagnet provided in the permanent magnet, so that the switching operation of the optical switch can be easily performed. The fact that there is no power consumption for fixed holding and that there is no position fluctuation when the power is cut off are the same as in the first aspect of the invention.

Since the manufacturing of the optical switch is performed by etching the silicon plate and then forming the core by plating, and by forming the electromagnetic coil or the electromagnet by plating and insulating film patterning in another process, the process is simple. It is simple and each part can be formed with high positional accuracy.

Since a pair of permanent magnets are shared by a plurality of optical switches to form an optical switch system, the structure is simple, the manufacturing is easy, and the cost is reduced.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an optical switch according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of the optical switch according to the first embodiment.

3A and 3B are views showing a manufacturing process of a substrate portion of the optical switch according to the first embodiment, FIG. 3A is a cross-sectional view of a silicon plate having a three-layer structure, and FIG. It is a figure, (c) is sectional drawing which formed the electrode for core formation, (d) is sectional drawing which formed the core by permalloy plating.

4A and 4B are diagrams showing a manufacturing process of the electromagnetic coil of the optical switch according to the first embodiment, FIG. 4A is a cross-sectional view of a silicon coil base, and FIG. 4B is a through-hole formed in the coil base. It is sectional drawing, (c) is sectional drawing which formed the insulating film for coil patterns, (d) is sectional drawing which formed the copper coil of single layer by copper plating, (e) is (c), It is sectional drawing which repeated (d) several times and formed the electromagnetic coil.

FIG. 5 is a diagram showing the principle of an electromagnet.

6A and 6B are diagrams showing a method of driving the optical switch according to the first embodiment, in which FIG. 6A is a sectional view showing an ON position;
(B) is a cross-sectional view showing a state in which a current is started to flow through an electromagnetic coil for driving, (c) is a cross-sectional view showing a movement from an ON position to an OFF position, and (d) is an OFF position. It is sectional drawing shown.

7A and 7B are schematic plan views showing different connection states of the optical switch system using the four optical switches according to the first embodiment.

FIG. 8 is a schematic perspective view of an optical switch according to a second embodiment.

FIG. 9 is a schematic perspective view of an electromagnet according to a second embodiment.

FIG. 10A is a perspective view showing a structure of an electromagnetic coil in the electromagnet according to the second embodiment, and FIG. 10B is a perspective view showing a structure of the electromagnetic coil.

FIG. 11 is a diagram showing the first half of the manufacturing process of the electromagnet according to the second embodiment, (a) is a sectional view of a permalloy plate, and (b) is a sectional view in which an insulating film is formed,
(C) is a sectional view in which an insulating film for a coil pattern is formed in a bottom portion, (d) is a sectional view in which a bottom portion is formed by copper plating, and (e) is a coil pattern in a side portion and a center portion. It is sectional drawing which formed the insulating film for core patterns.

FIG. 12 is a diagram showing the latter half of the electromagnet manufacturing process according to the second embodiment, wherein (a) is a cross-sectional view showing a side portion formed by copper plating and a central core formed by electrolytic plating; ) Is a cross-sectional view in which an upper side portion is formed by copper plating after forming an insulating film, (c) is a cross-sectional view in which an insulating film is formed on the entire upper surface, and (d) is a top core formed by electrolytic plating. FIG.

FIG. 13 is a top view showing a state where the bottom portion of the electromagnetic coil is formed during manufacturing of the electromagnet.

FIG. 14 is a diagram showing a method of driving the optical switch according to the second embodiment, in which (a) is a cross-sectional view showing an ON position;
(B) is a sectional view showing a state in which a current is started to flow through the electromagnetic coil for driving from ON to OFF, and (c) is OFF.
It is a sectional view showing a position, (d) is a sectional view showing a state in which a current has begun to flow through an electromagnetic coil for driving from OFF to ON, and (e) is a sectional view showing returning to an ON position. Is.

FIG. 15 is a schematic view of the electromagnet according to the second embodiment as viewed obliquely from above.

[Explanation of symbols]

1 optical switch 2 mirror 3 electromagnetic coil 4 substrates 5 cores 6 leaf spring (elastic member) 7 Lower permanent magnet 8 Upper permanent magnet 12 Silicon plate 41 Electromagnet 42 Fixed holding part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Manabu Murayama             4-3 Ikejiri, Itami City, Hyogo Prefecture Mitsubishi Electric Cable             Industrial Co., Ltd. Itami Works F-term (reference) 2H041 AA14 AA15 AA16 AB13 AC05                       AZ02 AZ05 AZ08

Claims (5)

[Claims] 1. An optical switch in which a mirror for reflecting signal light is operated to enter and retract into a signal light path, and a pair of permanent magnets arranged opposite to each other, each having an electromagnetic coil, and the pair of permanent magnets. A substrate disposed between magnets, the substrate having a core made of a ferromagnetic material and forming an electromagnet together with the electromagnetic coil, and the mirror, and the substrate, together with the mirror, supported so as to be able to move in and out of the signal optical path. The electromagnet includes an elastic member, and when the core is attracted to one of the permanent magnets, the core moves from the one permanent magnet to the other permanent magnet by energizing the electromagnetic coil. And is attracted to the other permanent magnet. When the core is attracted to one of the two permanent magnets, the mirror enters the signal optical path. Person,
An optical switch, characterized in that the mirror is retracted from the signal light path when the core is attracted to the other. 2. A pair of permanent magnets arranged opposite to each other, each of which has an electromagnet, and a pair of permanent magnets, wherein the pair of permanent magnets are mirrors that reflect the signal light and operate so as to move in and out of the signal light path. A substrate having a fixed holding part made of a ferromagnetic material and the mirror, and an elastic member for supporting the substrate together with the mirror so as to enter and retract into the signal optical path, Means that when the fixed holding portion is attracted to one of the two electromagnets, the fixed holding portion moves from the one electromagnet to the other electromagnet by energizing the other electromagnet to move the other electromagnet. When the fixed holding portion is attached to one of the electromagnets, the mirror is entering the signal optical path, while the fixed holding portion is attached to the other. Sometimes, an optical switch, characterized by being configured to mirror is retracted from the optical signal path. 3. The method of manufacturing an optical switch according to claim 1, wherein a step of etching a silicon plate to integrally form the mirror, the substrate and the elastic member, and forming the core on the substrate by plating. And a step of forming the electromagnetic coil by plating at least. 4. The method of manufacturing an optical switch according to claim 2, wherein a step of etching a silicon plate to integrally form the mirror, the substrate and the elastic member, and plating the fixed holding portion on the substrate. And a step of forming at least the electromagnetic coil of the electromagnet by plating. 5. An optical switch system for arranging a plurality of the optical switches according to claim 1 or 2 to switch a plurality of signal light emission locations, wherein the plurality of optical switches share a pair of permanent magnets. An optical switch system characterized in that