JP2019074766A - Mirror drive device and manufacturing method of the same - Google Patents

Abstract

To secure a magnetic field acting on a drive coil, and attain miniaturization when the drive coil is arranged in a surface on an opposite side of a mirror in a movable part.SOLUTION: A mirror drive device 1 comprises: a support part 20; a movable part 22; a permanent magnet 10 that forms a magnetic field around the movable part 22; and a wire substrate 12 that is arranged between the support part 20 and the permanent magnet 10 in an opposing direction of a pair of principal surfaces of the movable part 22 so that the movable part 22 is located on an inner side when viewed from the opposing direction. The movable part 22 includes: a mirror arrangement part 36; a mirror 48 that is arranged on a side of the principal surface 36b; and a drive coil 46 that is arranged on a side of the principal surface 36a so as to face the permanent magnet 10. The support 20 has: a base 24 that is connected to a connection member 38; and a reinforcement part 26 that extends from the base 24 toward a side away from the permanent magnet 10 and the wire substrate 12. The drive coil 46 is connected to electrodes 56a to 56d by lead-out conductors 42a to 42d.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a mirror drive device and a method of manufacturing the same.

  2. Description of the Related Art In recent years, research on mirror drive devices using MEMS (Micro Electro Mechanical System) technology (also referred to as micromachine technology) in which mechanical elements of minute size and electronic circuit elements are fused has been actively conducted. Patent documents 1 and 2 disclose an example of an electromagnetic mirror drive device.

  For example, the mirror drive device disclosed in Patent Document 2 includes a support portion, a movable portion, a mirror, a drive coil, and a pair of permanent magnets. The support portion pivotally supports the movable portion via the connection member. The mirror is disposed on the surface of the movable part. The drive coil is disposed on the back surface which is the surface on the same side as the mirror or the surface opposite to the mirror in the movable portion. The pair of permanent magnets are disposed such that the movable portion is positioned therebetween in a direction intersecting the normal direction of the surface of the movable portion.

  When current flows in the drive coil, Lorentz force is generated in the drive coil by interaction with the magnetic field generated around the movable part by the pair of permanent magnets, and the movable part swings. When the movable portion swings, the direction of the mirror disposed on the surface of the movable portion changes, so that the optical path of the reflected light from the mirror is changed. Such a mirror driving device is applied to, for example, an optical switch for optical communication, an optical scanner, and the like.

Japanese Patent Application Laid-Open No. 2002-040355 JP-A-11-231252

  When the drive coil is disposed on the back of the movable portion, the following advantages are obtained. That is, since the drive coil does not exist on the surface on the same side as the mirror in the movable portion, (1) the mirror can be formed large, and (2) the mirror is not affected by the unevenness of the drive coil, and a flat mirror is formed. it can.

  By the way, when the movable part is disposed between a pair of permanent magnets in the direction crossing the normal direction of the surface of the movable part as in the mirror driving device described in Patent Document 2, the permanent magnet and the movable part are movable. The distance to the drive coil formed in the portion tends to be large, and a sufficiently large magnetic field may not easily act on the drive coil. Therefore, there is a demand for bringing the permanent magnet closer to the drive coil and causing a larger magnetic field to act on the drive coil. Therefore, it is conceivable to adopt one permanent magnet disposed so as to overlap the support portion and the movable portion when viewed in the normal direction of the surface of the movable portion. In this case, since the permanent magnet and the movable portion are adjacent to each other in the normal direction, the permanent magnet as a whole approaches the drive coil. Therefore, a larger magnetic field can act on the drive coil.

  On the other hand, there is also a demand to miniaturize the mirror drive device. However, as described above, when the drive coil is disposed on the back surface of the movable portion and one permanent magnet is disposed so as to overlap the support portion and the movable portion when viewed from the normal direction, for the following reasons. There is a tendency for the device to become larger. That is, in order to supply power to the drive coil to drive the mirror, it is necessary to electrically connect the mirror drive device to the electrode of the wiring board which is located outside and connected to the power supply. . Specifically, a lead conductor is laid from the end of the drive coil to the support portion, and the lead conductor is connected to an electrode disposed on the same side of the support portion as the back surface of the movable portion, It is necessary to electrically connect the electrodes of the wiring board. Conventionally, a wire bonding method has generally been adopted for such electrical connection. Therefore, in order to secure a region for providing an electrode in the support portion or to arrange a wire in the vicinity of the support portion Space for the Then, the support portion becomes larger than necessary, and the mirror drive device also becomes larger as a whole by the space secured around the support portion.

  Therefore, in the present disclosure, when the drive coil is disposed on the surface on the opposite side to the mirror in the movable portion, the mirror drive device capable of achieving miniaturization while securing the magnetic field acting on the drive coil and the same The manufacturing method will be described.

  A mirror drive device according to one aspect of the present disclosure includes a support having a frame shape, and first and second main surfaces located on the inner side of the support and opposed to each other, and the support via a coupling member. The movable portion supported so as to be pivotable, and the first and second principal surfaces are positioned to face the support portion and the second principal surface in the opposing direction, and a magnetic field is formed around the movable portion A movable magnetic body having a frame shape, and a wiring board disposed between the support portion and the magnetic body in the opposite direction so that the movable portion is located inside when viewed from the opposite direction, The portion includes a base including the first and second main surfaces, a mirror disposed on the first main surface, and a drive coil disposed on the second main surface so as to face the magnetic body. The support portion has a frame shape, a base portion connected to the connection member, and a frame shape, and the magnetic body and the wiring in the opposing direction The drive coil includes a reinforcing portion extending from the base in a direction away from the plate, and an electrode disposed on the surface of the base facing the magnetic body and in a position overlapping the reinforcing portion when viewed from the opposite direction. The electrode is connected to the electrode by a lead conductor extending from the movable portion to the support via the connecting member, and the electrode is electrically connected to the wiring substrate.

  In the mirror drive device according to one aspect of the present disclosure, the drive coil is disposed on the surface side facing the magnetic body of the base by the lead conductor extending from the movable portion to the support portion via the coupling member. The electrode is connected with the wiring substrate, and the electrode is electrically connected with the wiring substrate disposed between the support portion and the magnetic body in the opposing direction of the first and second main surfaces. Thus, the presence of the wiring board between the support portion and the magnetic body makes it possible to electrically connect the electrode and the wiring board disposed on the surface side of the base facing the magnetic body. Therefore, even when the drive coil is disposed on the surface of the movable portion opposite to the mirror, the drive coil can be electrically connected to the outside.

  In the mirror drive device according to one aspect of the present disclosure, the magnetic body faces the second main surface in the facing direction. Therefore, since the magnetic body and the movable portion are adjacent to each other in the facing direction, the magnetic body as a whole approaches the drive coil disposed on the second main surface side of the movable portion. Therefore, the magnetic field acting on the drive coil can be secured.

  In the mirror driving device according to one aspect of the present disclosure, the wiring substrate is disposed between the support portion and the magnetic body and the movable portion is on the inner side of the wiring substrate when viewed from the opposing direction of the first and second main surfaces. It is located in Therefore, the wiring board located between the support portion and the magnetic body also functions as a spacer for separating the movable portion and the magnetic body. Therefore, the space for swinging the movable portion can be secured by the wiring board. In addition, since the wiring board has both the function of supplying electricity to the drive coil and the function of the spacer, the mirror drive device can be miniaturized.

  In the mirror drive device according to one aspect of the present disclosure, the electrode is disposed on the surface side of the base facing the magnetic body and at a position overlapping the reinforcing portion when viewed from the facing direction. Therefore, when a stress or the like occurs when the wiring substrate and the drive coil are electrically connected, the reinforcing portion mainly receives the stress or the like through the electrode and the base. Therefore, the movable portion is less susceptible to the stress and the like.

  In the present specification, "the opposing direction of the first and second main surfaces" means the opposing direction in the non-driven state (the non-energized state in which the current does not flow in the drive coil) of the mirror drive device. I assume. In the non-driven state of the mirror drive device, the second main surface of the movable portion and the surface of the magnetic body facing the second main surface substantially face each other.

  The wiring board may be disposed on the surface of the magnetic body facing the second main surface.

  In the opposite direction, the sum of the thickness of the base and the reinforcing portion may be thicker than the thickness of the movable portion. In this case, since the strength of the support portion is further increased, even if a stress or the like occurs when the wiring substrate and the drive coil are electrically connected, the movable portion is further less affected by the stress or the like.

  The mirror drive device according to one aspect of the present disclosure may further include a bump electrode which is disposed between the wiring substrate and the support portion and which connects the wiring substrate and the electrode. In this case, since the bump electrode exists between the magnetic body and the support portion, the distance between the second main surface and the magnetic body is further increased. Therefore, the space in which the movable portion swings can be further secured.

  The base material includes a groove portion located on the second main surface side and extending in a spiral shape as viewed from the direction orthogonal to the second main surface, and the drive coil is a first metal disposed in the groove portion While being comprised by material, it may be spirally wound seeing from the direction orthogonal to the main surface.

  The movable portion covers the opening of the groove portion and a covering layer made of a second metal material which suppresses diffusion of the first metal material, and an insulating layer disposed on the second major surface and on the covering layer And may be further included. In this case, the first metal material constituting the drive coil is difficult to diffuse into the insulating layer, and the occurrence of short circuit is prevented. Therefore, the conduction failure due to the short circuit can be eliminated. Along with this, a drive coil wound at high density is realized, so that a greater Lorentz force can be exerted on the drive coil. As a result, it is possible to obtain a mirror drive device in which the movable range of the mirror is large.

  The first metal material may be Cu or Au, and the second metal material may be Al or an alloy containing Al. The first metal material, Cu or Au, is a material that has relatively low electrical resistivity but is relatively easy to diffuse, but the presence of the covering layer can suppress the diffusion of these materials. In particular, since the second metal material forming the covering layer is Al or an alloy containing Al, the diffusion of the first metal material is extremely well suppressed. Therefore, it is possible to prevent the occurrence of a short circuit while reducing the electrical resistivity of the drive coil.

  The movable portion may further include an insulating layer covering the opening of the groove.

  The material forming the insulating layer is SiN, and the thickness of the insulating layer may be 50 nm or more. In this case, the diffusion of the metal material constituting the drive coil is suppressed.

  The movable portion has a mirror placement portion including a portion on which the mirror is disposed in the base, an outer portion including a frame-like portion surrounding the outer periphery of the mirror placement portion on the base, and two drive coils. The outer portion is pivotally supported by the support portion via the coupling member, and the mirror placement portion is pivotally supported at the outer portion through another coupling member extending in a direction intersecting the coupling member. Each of the two drive coils is spirally wound as viewed in the direction orthogonal to the second main surface, and one of the two drive coils is on the side of the second main surface of the mirror arrangement portion. The other drive coil of the two drive coils is disposed on the side of the second main surface in the outer portion, and the surface of the magnetic body facing the second main surface is along the surface A set of magnetic poles consisting of south poles and north poles arranged side by side in the direction appears Cage, the other drive coils may have a portion located in a first region where the magnetic flux density of the magnetic field formed around the movable portion by pole pairs exhibits a substantially maximum value. In this case, since the mirror arrangement portion is swingably supported on the outer side portion through another connection member extending in the direction intersecting the connection member, the outer side portion and the mirror arrangement portion with respect to different swing axes Swing. Therefore, it is possible to two-dimensionally scan the reflected light of the mirror. By the way, when the reflected light of the mirror is two-dimensionally scanned, the mirror placement portion is quickly swung to scan the reflected light at high speed along the first scanning direction, and intersects the first scanning direction. In order to scan the reflected light intermittently along the second scanning direction, it is conceivable to swing the outer portion at a swing angle larger than that of the mirror placement portion. At this time, as described above, the other drive coil is located in the first region in which the magnetic flux density substantially shows the maximum value in the magnetic field formed around the movable portion by the set of the first and second magnetic poles. By including the portion, it is possible to increase the Lorentz force acting on the other drive coil while reducing the magnitude of the current supplied to the other drive coil disposed in the outer side. Therefore, low power consumption can be achieved while increasing the swing angle of the outer portion.

  In the present specification, “approximately maximum value” refers to a range having the maximum value as the upper limit and 80% of the maximum value as the lower limit. Further, the “maximum value” refers to the largest value of the magnetic flux density of the magnetic field formed by the permanent magnet at the position of the movable part.

  The magnetic body has first to third magnetic portions arranged in order to form a Halbach array along a predetermined direction, and the other drive coil has a portion located in the first region. May be In this case, the magnetic flux density in the vicinity of the other drive coil is further increased by the first to third magnetic parts constituting the Halbach arrangement.

  The magnetic body includes: first and second magnetic portions adjacent along a first direction orthogonal to the opposite direction; third and fourth magnetic portions adjacent along the first direction; The fifth and sixth magnetic parts are arranged along a second direction orthogonal to both of the first directions, and the fifth and sixth magnetic parts are a second magnetic part and a third magnetic part. And adjacent to the second and third magnetic portions in the first direction, and the magnetization directions of the first, third and fifth magnetic portions are all on the first main surface. The direction of the magnetization of the second, fourth and sixth magnetic parts is from the side of the second main surface toward the side of the first main surface, and the other drive coil The may have a portion located in the first area. In this case, the first to sixth magnetic parts arranged in the specific state as described above can form a larger magnetic flux density in the vicinity of the other drive coils.

  One drive coil may have a portion located in a second area other than the first area. By the way, current of a frequency corresponding to the resonance frequency of the mirror placement portion may be supplied to one drive coil, and the reflected light may be scanned at high speed along the first scanning direction. That is, since the mirror placement part swings due to resonance, it is not necessary for the large Lorentz force to act on one of the drive coils in order to swing the mirror placement part. In this case, when one drive coil has a portion located in the second area, the other drive coil is likely to be located in the first area. Therefore, the Lorentz force acting on the other drive coil can be further increased.

  According to another aspect of the present disclosure, there is provided a method of manufacturing a mirror drive device including: a support having a frame shape; and first and second main surfaces located on the inner side of the support and opposed to each other. A movable portion rotatably supported by the support portion, the movable portion including a base including the first and second main surfaces, a mirror disposed on the first main surface, and a second And the support portion has a frame shape, and the base connected to the connecting member and the frame shape have the first and second main surfaces. A reinforcing portion extending from the base in a direction from the second main surface to the first main surface in the opposing direction in which the The driving coil extends from the movable portion to the support portion via the connecting member, and Preparing a mirror structure connected to the electrode by the lead conductor, and a magnetic body forming a magnetic field around the movable portion facing the support portion and the second main surface in the opposite direction, and in a frame shape Assembling the mirror structure, the magnetic body, and the wiring board such that the wiring board exhibiting the symbol is positioned outside the movable portion as viewed from the facing direction and the wiring board is positioned between the support portion and the magnetic body in the facing direction; Electrically connecting the wiring substrate and the drive coil via the electrodes.

  In the method of manufacturing a mirror drive device according to another aspect of the present disclosure, the surface side located on the opposite side to the reinforcing portion in the base by the lead conductor extending from the movable portion to the support via the coupling member. And the wiring substrate positioned between the support portion and the magnetic body in the opposing direction in which the first and second principal surfaces face each other. ing. Thus, by the presence of the wiring substrate between the support portion and the magnetic body, an electrical connection between the electrode and the wiring substrate disposed on the surface side opposite to the reinforcing portion in the base is obtained. It is possible. Therefore, even when the drive coil is disposed on the surface of the movable portion opposite to the mirror, the drive coil can be electrically connected to the outside.

  In the method of manufacturing a mirror drive device according to another aspect of the present disclosure, the magnetic body faces the second main surface in the facing direction. Therefore, since the magnetic body and the movable portion are adjacent to each other in the facing direction, the magnetic body as a whole approaches the drive coil disposed on the second main surface side of the movable portion. Therefore, the magnetic field acting on the drive coil can be secured.

  In the method of manufacturing a mirror drive device according to another aspect of the present disclosure, the wiring substrate is located outside the movable portion as viewed from the opposing direction and viewed from the opposing direction when the first and second main surfaces face each other. The wiring board is located between the support portion and the magnetic body in the direction. Therefore, the wiring board located between the support portion and the magnetic body also functions as a spacer for separating the movable portion and the magnetic body. Therefore, the space for swinging the movable portion can be secured by the wiring board. In addition, since the wiring board has both the function of supplying electricity to the drive coil and the function of the spacer, the mirror drive device can be miniaturized.

  In the method of manufacturing a mirror drive device according to another aspect of the present disclosure, the electrode is disposed on the surface side of the base facing the magnetic body and at a position overlapping the reinforcing portion when viewed from the facing direction. Therefore, when a stress or the like occurs when the wiring substrate and the drive coil are electrically connected, the reinforcing portion mainly receives the stress or the like through the electrode and the base. Therefore, the movable portion is less susceptible to the stress and the like.

  According to another aspect of the present disclosure, there is provided a method of manufacturing a mirror drive device, in which a wire is formed on a part of the surface of a magnetic body after preparing a mirror structure and before electrically connecting the wiring board and the drive coil. The method may further include disposing the substrate. In this case, since the wiring substrate exists between the magnetic body and the support portion, the linear distance between the second main surface and the magnetic body is further increased. Therefore, a space in which the movable portion swings can be sufficiently secured. Further, in this case, in the manufacture of the mirror drive device, the mirror structure may be mounted on the wiring substrate such that the support portion overlaps the wiring substrate. Therefore, at the time of manufacture of the mirror drive device, a load hardly acts on the mirror with small intensity. Therefore, since the mirror is less likely to be damaged in the manufacturing process of the mirror drive device, the yield can be increased.

  A method of manufacturing a mirror drive device according to another aspect of the present disclosure further includes disposing a bump electrode on the electrode after preparing the mirror structure and before electrically connecting the wiring substrate and the drive coil. When the wiring substrate and the drive coil are electrically connected, the mirror structure and the bump electrode, and the magnetic body and the wiring substrate may be assembled by connecting the bump electrode to the wiring substrate. In this case, since the bump electrode exists between the magnetic body and the support portion, the distance between the second main surface and the magnetic body is further increased. Therefore, the space in which the movable portion swings can be further secured.

  According to the mirror drive device and the method of manufacturing the same according to the present disclosure, when the drive coil is disposed on the surface of the movable portion opposite to the mirror, miniaturization is achieved while securing the magnetic field acting on the drive coil. It becomes possible.

FIG. 1 is a perspective view showing a mirror drive device according to the present embodiment. FIG. 2 is a plan view showing a mirror drive device according to the present embodiment. FIG. 3 is a cross-sectional view taken along line II-II of FIG. FIG. 4 is a perspective view showing a permanent magnet. FIG. 5 is a plan view showing the upper surface side of the wiring substrate. FIG. 6 is a plan view showing the lower surface side of the mirror structure. 7 is a cross-sectional view taken along line VII-VII in FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. FIG. 9 is a view for explaining a part of the manufacturing process of the mirror drive device according to the present embodiment. FIG. 10 is a diagram for illustrating the process following FIG. FIG. 11 is a plan view showing the upper surface side of a wiring board according to another example. FIG. 12 is a plan view showing the lower surface side of a mirror structure according to another example. FIG. 13 is a plan view showing the upper surface side of a wiring board according to another example. FIG. 14 is a cross-sectional view showing another configuration example in the vicinity of the drive coil. FIG. 15 is a plan view showing the upper surface side of a mirror structure according to another example. FIG. 16 is a plan view showing the upper surface side of a mirror structure according to another example. FIG. 17 is a perspective view showing a mirror drive device provided with a mirror structure according to another example. FIG. 18 is a perspective view showing a permanent magnet according to another example. 19A shows a cross section taken along line XIXA-XIXA of FIG. 18, and FIG. 19B shows a magnetic field formed around the movable portion by permanent magnets in the cross section taken along line XIXA-XIXA of FIG. It is a graph which shows the appearance of magnetic flux density. FIG. 20A shows a cross section taken along line XXA-XXA of FIG. 18, and FIG. 20B shows a cross section taken along line XXA-XXA of FIG. It is a graph which shows the appearance of magnetic flux density. (A) of FIG. 21 shows a cross section taken along line XXIA-XXIA of FIG. 18, and (b) of FIG. 21 shows a cross section taken along line XXIB-XXIB of FIG. FIG. 22 is a perspective view showing a permanent magnet according to another example.

  Embodiments of the present invention will be described with reference to the drawings, but the following present embodiments are exemplifications for describing the present invention, and are not intended to limit the present invention to the following contents. In the description, the same elements or elements having the same function will be denoted by the same reference numerals, and redundant description will be omitted.

  The mirror drive device 1 is provided with the permanent magnet 10, the wiring board 12, and the mirror structure 14 as FIG. 1-FIG. 3 show. The permanent magnet 10, the wiring board 12 and the mirror structure 14 are arranged in this order in the Z-axis direction (vertical direction in FIG. 1 etc. and hereinafter simply referred to as "Z-axis direction") shown in FIG. It is.

  The permanent magnet 10 is a flat plate having a rectangular shape as shown in FIGS. 3 and 4. The permanent magnet 10 forms a magnetic field (magnetic field) around movable parts 22 (driving coils 40 and 46 described later) described later. The thickness of the permanent magnet 10 may be set to, for example, about 2 mm to 3 mm.

  The permanent magnet 10 has a pair of main surfaces 10a and 10b having a rectangular shape. That is, when viewed from the Z-axis direction, the main surfaces 10a and 10b are a pair of sides extending along the X-axis direction orthogonal to the Z-axis direction, and a Y-axis orthogonal to both the Z-axis direction and the X-axis direction And a pair of sides extending along the direction. The main surfaces 10a and 10b have a planar shape. The normal direction of the main surfaces 10a and 10b of the permanent magnet 10 coincides with the Z-axis direction in the present embodiment.

  The permanent magnet 10 has magnetic parts 10A to 10C. As shown in FIG. 4, the magnetic parts 10A and 10C are respectively located on one end side and the other end side in the diagonal direction of the bottom of the permanent magnet 10. The magnetic portion 10B is located between the magnetic portion 10A and the magnetic portion 10C. That is, the magnetic parts 10A to 10C are arranged in this order in a predetermined direction.

  A boundary surface 10D is formed by a surface where the magnetic portion 10A and the magnetic portion 10B are in contact with each other. A boundary surface 10E is formed by the surface where the magnetic portion 10B and the magnetic portion 10C are in contact with each other. The boundary surfaces 10D and 10E extend substantially parallel to the Z-axis direction and substantially parallel to each other. The boundary surfaces 10D and 10E intersect in both the X-axis direction and the Y-axis direction. The boundary surfaces 10D and 10E may be orthogonal to a bisector that bisects an angle formed by the X axis and the Y axis, for example.

  Returning to FIG. 3, the magnetic portion 10A has magnetic poles 10A1 and 10A2 of different polarities. The magnetic pole 10A1 is located on the main surface 10a side. The magnetic pole 10A2 is located on the main surface 10b side. The magnetic portion 10B has magnetic poles 10B1 and 10B2 of different polarities. The magnetic pole 10B1 is located on the boundary surface 10D side. The magnetic pole 10B2 is located on the boundary surface 10E side. The magnetic portion 10C has magnetic poles 10C1 and 10C2 of different polarities. The magnetic pole 10C1 is located on the main surface 10b side. The magnetic pole 10C2 is located on the main surface 10a side.

  In the present embodiment, the magnetic poles 10A1, 10B1, and 10C1 are S poles. On the other hand, the magnetic poles 10A2, 10B2 and 10C2 are N poles. Therefore, a demagnetizing field is generated in the magnetic portion 10A from the major surface 10b to the major surface 10a. Inside the magnetic portion 10B, a demagnetizing field is generated from the interface 10E to the interface 10D. Inside the magnetic portion 10C, a demagnetizing field is generated from the major surface 10a to the major surface 10b. From the above, on the main surface 10a, a set of the magnetic pole 10B1 (S pole) and the magnetic pole 10B2 (N pole) arranged adjacent to each other in the direction along the main surface 10a appears.

  The directions of the demagnetizing fields are orthogonal to each other between the adjacent magnetic parts 10A and 10B. The directions of the demagnetizing fields are orthogonal to each other between the adjacent magnetic parts 10B and 10C. In the magnetic parts 10A and 10C located with the magnetic part 10B in between, the directions of the demagnetizing fields are opposite to each other. Thus, the magnetic parts 10A to 10C constitute a Halbach arrangement. Therefore, a magnetic field is formed intensively on the main surface 10 a side of the permanent magnet 10 and in the vicinity of the movable portion 22 described later. Specifically, a magnetic field is formed intensively on the main surface 10a side of the permanent magnet 10 and in the vicinity of the boundary of the set of the magnetic pole 10B1 and the magnetic pole 10B2. The magnetic flux density of the magnetic field formed around the movable portion 22 by the combination of the magnetic pole 10B1 and the magnetic pole 10B2 shows a substantially maximum value near the boundary of the pair of the magnetic pole 10B1 and the magnetic pole 10B2 and tends to decrease as it goes away from the boundary It is in.

  The wiring board 12 is, for example, a flexible printed board. As shown in FIGS. 1, 3 and 5, the wiring board 12 is a frame-like member having a rectangular outer shape as viewed from the Z-axis direction, and has an annular shape with a central portion opened. The wiring substrate 12 is attached on the major surface 10 a of the permanent magnet 10 by, for example, an adhesive. The wiring substrate 12 extends along each side of the permanent magnet 10 on the major surface 10 a of the permanent magnet 10. That is, wiring board 12 includes a pair of first portions 12a extending along the X-axis direction and a pair of second portions extending along the Y-axis direction, corresponding to each side of permanent magnet 10. And a portion 12b (see FIG. 5).

  Electrodes 16a to 16d are disposed on the surface 12c of one of the pair of second portions 12b. Electrodes 18a to 18d are disposed on the surface 12c of the other of the pair of second portions 12b. The surface 12c of the second portion 12b where the electrodes 16a to 16d and 18a to 18d are disposed is opposite to the surface 12d of the second portion 12b facing the major surface 10a of the permanent magnet 10 (see FIG. 3) It is a side surface, that is, a surface facing the mirror structure 14.

  Returning to FIG. 5, the electrodes 16 a to 16 d are electrically connected to drive coils 40 and 46 described later. On the other hand, the electrodes 18a to 18d are dummy electrodes for height adjustment, and are not electrically connected to drive coils 40 and 46 described later.

  The mirror structure 14 has a support portion 20 and a movable portion 22 as shown in FIG. The support portion 20 is a frame-like member having a rectangular shape, and a central portion is opened. The thickness of the support portion 20 may be set to, for example, about 250 μm to 300 μm.

  The support portion 20 overlaps the main surface 10 a of the permanent magnet 10 and the wiring substrate 12 when viewed from the Z-axis direction (the normal direction of the main surface 10 a of the permanent magnet 10). The support portion 20 has a surface 20 a on the side facing the permanent magnet 10 and the wiring board 12 and a surface 20 b on the side farther from the permanent magnet 10 and the wiring board 12 than the surface 20 a. The support 20 includes a base 24 and a reinforcement 26.

  The base portion 24 and the reinforcing portion 26 are both frame-like members having a rectangular shape, and the central portion is opened. The base 24 is located on the surface 20 a side of the support portion 20. The thickness of the base 24 is substantially the same as the thickness of the movable portion 22. The reinforcing portion 26 is located on the surface 20 b side of the support portion 20. That is, the reinforcing portion 26 extends from the base 24 toward the side away from the permanent magnet 10 and the wiring board 12. Therefore, in the Z-axis direction, the thickness of the support portion 20 (the sum of the thicknesses of the base portion 24 and the reinforcing portion 26) is larger than the thickness of the movable portion 22. Both the base 24 and the reinforcing portion 26 may be made of, for example, Si (silicon).

  An insulating layer 28 is disposed on the surface 20 a side of the base 24. That is, the surface of the insulating layer 28 forms the surface 20 a of the support portion 20. As shown in FIG. 6, electrodes 56 a to 56 d are disposed on insulating layer 28 at positions corresponding to electrodes 16 a to 16 d of wiring board 12, and positions corresponding to electrodes 18 a to 18 d of wiring board 12. The electrodes 58a to 58d are disposed on the The electrodes 58a to 58d are dummy electrodes for height adjustment, and are not electrically connected to drive coils 40 and 46 described later. The electrodes 56a to 56d and 58a to 58d are located at the end of the base 24 (support portion 20) close to the permanent magnet 10.

  As shown in FIG. 3, the electrodes 56a to 56d are electrically and physically connected to the corresponding electrodes 16a to 16d by the bump electrode 60. The electrodes 58a to 58d are electrically and physically connected to the corresponding electrodes 18a to 18d by the bump electrode 60. Therefore, the bump electrode 60 is disposed between the wiring substrate 12 and the support portion 20.

An insulating layer 30 is disposed between the base 24 and the reinforcing portion 26. An insulating layer 32 is disposed on the surface 20 b side of the reinforcing portion 26. That is, the surface of the insulating layer 32 forms the surface 20 b of the support portion 20. The insulating layers 28, 30, 32 may be made of, for example, silicon dioxide (SiO ₂ ).

  The movable portion 22 is located inside (within the opening) of the support portion 20 as shown in FIGS. 1 to 3. The movable portion 22 has one main surface facing the permanent magnet 10 and the other main surface facing the permanent magnet 10 on the opposite side. The opposing direction of the pair of main surfaces coincides with the Z-axis direction in the non-driven state of the mirror drive device 1 (the non-energized state in which no current flows through the drive coils 40 and 46 described later). The movable portion 22 is separated from the permanent magnet 10 and the support portion 20. The movable portion 22 does not overlap the wiring substrate 12 as viewed in the Z-axis direction. Therefore, the movable portion 22 is located inside (within the opening) of the wiring substrate 12 when viewed in the Z-axis direction. That is, the wiring board 12 is located outside the movable portion 22. The movable portion 22 has an outer portion 34 located outside and a mirror placement portion 36 located inside the outer portion 34.

  The outer side part 34 is a flat frame-like member which exhibits a rectangular shape. The outer side portion 34 surrounds the outer periphery of the mirror placement portion 36. The outer portion 34 has a main surface 34 a facing the permanent magnet 10 and a main surface 34 b facing the opposite side of the permanent magnet 10. The major surface 34 a is included in one major surface of the movable portion 22, and the major surface 34 b is included in the other major surface of the movable portion 22.

  The outer portion 34 is pivotably attached to the base 24 of the support portion 20 via a pair of connecting members 38 aligned in a straight line, as shown in FIGS. 1, 2 and 6. That is, the outer side portion 34 is supported so as to be capable of reciprocating rotational movement with respect to the base portion 24 (support portion 20) via the pair of connecting members 38. The swing angle of the outer portion 34 is, for example, about ± 5 ° to ± 10 °. The connecting member 38 has a linear shape in the present embodiment.

  As shown in FIG. 6, the drive coil 40 is disposed on the main surface 34 a side of the outer portion 34. Therefore, the drive coil 40 faces the main surface 10 a of the permanent magnet 10. A plurality of drive coils 40 are spirally wound on the main surface 34 a side of the outer portion 34 as viewed in the normal direction of the main surface 34 a. Drive coil 40 is positioned in a region where the magnetic flux density has a substantially maximum value among magnetic fields formed around movable portion 22 by magnetic portions 10A to 10B (a set of magnetic pole 10B1 and magnetic pole 10B2) in a Halbach array. Part has. The entire drive coil 40 may be located in the area.

  One end of the drive coil 40 is located outside the spiral drive coil 40. One end of a lead conductor 42 a is electrically connected to the outer end of the drive coil 40. The other end of the lead conductor 42a extends on the surface 20a of the connecting member 38 and the support portion 20 and is connected to the electrode 56d.

  The other end of the drive coil 40 is located inside the spiral drive coil 40. One end of the lead conductor 42 b is electrically connected to the inner end of the drive coil 40. The other end of the lead conductor 42b extends on the surface 20a of the connecting member 38 and the support portion 20 and is connected to the electrode 56b.

  The mirror placement portion 36 is a flat plate having a rectangular shape. The mirror placement portion 36 has a main surface 36 a facing the permanent magnet 10 and a main surface 36 b facing the opposite side of the permanent magnet 10. The major surface 36 a is included in one major surface of the movable portion 22, and the major surface 36 b is included in the other major surface of the movable portion 22.

  As shown in FIGS. 1, 2 and 6, the mirror placement portion 36 is swingably attached to the outer portion 34 via a pair of connection members 44 aligned on the same straight line. That is, the mirror placement portion 36 is supported for reciprocal rotational movement with respect to the outer side portion 34 via the pair of connecting members 44. The swing angle of the mirror placement portion 36 is, for example, about ± 5 ° to ± 10 °. The connecting member 44 has a linear shape in the present embodiment. The direction in which the pair of connecting members 44 are arranged is substantially orthogonal to the direction in which the pair of connecting members 38 are arranged as viewed from the Z-axis direction.

  As shown in FIG. 6, the drive coil 46 is disposed on the main surface 36 a side of the mirror placement portion 36. Therefore, the drive coil 46 faces the main surface 10 a of the permanent magnet 10. A plurality of drive coils 46 are spirally wound on the main surface 36 a side of the mirror placement portion 36 as viewed in the normal direction of the main surface 36 a.

  One end of the drive coil 46 is located outside the spiral drive coil 46. One end of the lead conductor 42 c is electrically connected to the outer end of the drive coil 46. The other end of the lead conductor 42c extends on the connecting member 44, the major surface 34a of the outer portion 34, the connecting member 38 and the surface 20a of the support portion 20, and is connected to the electrode 56c.

  The other end of the drive coil 46 is located inside the spiral drive coil 46. One end of the lead conductor 42 d is electrically connected to the inner end of the drive coil 46. The other end of the lead conductor 42d extends on the connecting member 44, the major surface 34a of the outer portion 34, the connecting member 38 and the surface 20a of the support portion 20, and is connected to the electrode 56a.

  As shown in FIGS. 1 to 3, the mirror 48 is disposed on the main surface 36 b side of the mirror placement portion 36. The mirror 48 is a light reflecting film made of a metal thin film. As a metal material which constitutes mirror 48, aluminum (Al), gold (Au), silver (Ag) is mentioned, for example.

As shown in FIG. 3, an insulating layer 50 is disposed on the surface of the outer portion 34, the mirror placement portion 36, and the coupling members 38 and 44 on the side facing the permanent magnet 10. That is, the surface of the insulating layer 50 forms the major surface 34 a of the outer portion 34 and the major surface 36 a of the mirror placement portion 36. An insulating layer 52 is disposed on the surface of the outer side portion 34, the mirror placement portion 36, and the connection members 38 and 44 on the side facing the permanent magnet 10 side. That is, the surface of the insulating layer 52 forms the major surface 34 b of the outer portion 34 and the major surface 36 b of the mirror placement portion 36. An insulating layer 54 is disposed on the surface of the mirror 48 facing the side opposite to the main surface 36 b of the mirror placement portion 36. The insulating layers 50, 52, 54 may be made of, for example, silicon dioxide (SiO ₂ ).

  Subsequently, the structure in the vicinity of the drive coil 46 will be described below. The structure in the vicinity of the drive coil 40 is the same as that in the vicinity of the drive coil 46, so the description thereof will be omitted.

  As shown in FIG. 7, the mirror placement portion 36 has a substrate 100, a drive coil 46, a covering layer 102, and an insulating layer 104. The base 100 has a groove 100 a having a shape corresponding to the drive coil 46 on the surface on the main surface 36 a side of the mirror placement portion 36. That is, the groove portion 100 a extends in a spiral shape as viewed from the normal direction of the main surface 36 a of the mirror placement portion 36. The thickness of the substrate 100 may be set to, for example, about 20 μm to 60 μm.

The insulating layer 100 b is disposed on the surface of the base 100 on the main surface 36 a side of the mirror placement portion 36 and the inner wall surface of the groove 100 a. The insulating layer 100 b is a thermal oxide film obtained by thermally oxidizing the base material 100. The insulating layer 100b may be made of, for example, SiO ₂ (silicon oxide). The seed layer 100c is disposed on the inner wall surface of the groove 100a and on the insulating layer 100b. That is, the seed layer 100 c is located between the insulating layer 100 b and the drive coil 46. The metal material constituting the seed layer 100c may be, for example, TiN.

  In the groove portion 100a and on the seed layer 100c, a metal material constituting the drive coil 46 is disposed. Examples of the metal material include Cu or Au. The thickness of the drive coil 46 may be set to, for example, about 5 μm to 10 μm.

  The covering layer 102 extends on the surface on the main surface 36 a side of the mirror placement portion 36 so as to cover the opening of the groove portion 100 a. That is, the cover layer 102 covers the entire surface of the drive coil 46 on the side of the main surface 36 a of the mirror arrangement portion 36 as viewed in the normal direction of the main surface 36 a of the mirror arrangement portion 36. It covers the perimeter of 100a.

  The metal material forming the covering layer 102 has a function of suppressing the diffusion of the metal material forming the drive coil 46. Examples of the metal material constituting the covering layer 102 include Al or an alloy containing Al. Examples of the alloy containing Al include an Al-Si alloy, an Al-Cu alloy, and an Al-Si-Cu alloy. The composition ratio of the Al-Si alloy may be, for example, 99% of Al and 1% of Si. The composition ratio of the Al-Cu alloy may be, for example, 99% of Al and 1% of Cu. The composition ratio of the Al-Si-Cu alloy may be, for example, 98% of Al, 1% of Si, and 1% of Cu. The thickness of the covering layer 102 may be set to, for example, about 1 μm.

The insulating layer 104 is disposed to cover the upper surfaces of the substrate 100 and the covering layer 102. As a material for forming the insulating layer 104, for _example, SiO 2, SiN, is TEOS and the like. The insulating layer 104 is the same element as the insulating layer 50 shown in FIG.

  Subsequently, with reference to FIG. 8, the connection state between the inner end of the drive coil 40 and one end of the lead conductor 42b will be described. The connection between the outer end of the drive coil 40 and one end of the lead conductor 42a, the connection between the outer end of the drive coil 46 and one end of the lead conductor 42c, and the inner end of the drive coil 46 and one end of the lead conductor 42d The connection state with is the same as the connection state between the inner end of the drive coil 40 and one end of the lead conductor 42b, and thus the description thereof is omitted.

  As shown in FIG. 8, the upper side of the inner end of the drive coil 40 to which one end of the lead conductor 42 b is connected is not covered by the insulating layer 104. That is, the covering layer 102 at the inner end of the drive coil 40 is exposed to the outside through the opening 104 a formed in the insulating layer 104. One end of the lead conductor 42 b is embedded in the opening 104 a and is physically and electrically connected to the covering layer 102. The other part of the lead conductor 42 a is disposed on the insulating layer 104.

  Subsequently, with reference to FIGS. 9 and 10, a method of manufacturing the mirror driving device 1 described above will be described.

  First, as shown in FIG. 9A, for example, a silicon bonded substrate (so-called SOI substrate) of about 300 μm is prepared. The silicon bonded substrate is obtained by bonding the substrate 200, the intermediate layer 202, and the substrate 204 in this order. The thickness of the substrate 200 is, for example, about 50 μm. The intermediate layer 202 is made of a silicon oxide layer. The thickness of the intermediate layer 202 is, for example, about 1 μm. The thickness of the substrate 204 is, for example, about 250 μm.

  A silicon oxide film 206 is formed on the surface of the substrate 204 by thermal oxidation. The thickness of the silicon oxide film 206 is, for example, about 0.5 μm. Next, the groove 100 a is formed on the surface of the substrate 200. The groove portion 100 a is formed, for example, by forming a mask of a predetermined pattern on the surface of the substrate 200 and subsequently etching the substrate 200 through the mask.

  Next, the surface of the substrate 200 is thermally oxidized to form the insulating layer 100 b. Next, a seed layer 100c is formed on the insulating layer 100b, which is an inner wall surface of the groove 100a. The seed layer 100c is obtained by sputtering a dense metal material having adhesiveness to the metal material constituting the drive coil 46 on the base 100 (insulating layer 100b).

  Next, the drive coil 46 is formed in the groove 100a. Specifically, the drive coil 46 is obtained by embedding a metal material on the seed layer 100c by a damascene method. Examples of the method for embedding the metal material in the groove 100a include plating, sputtering, and CVD. After the metal material is disposed in the groove 100a, the surface of the substrate 200 (the surface on the main surface 36a side of the mirror placement portion 36) may be planarized by chemical mechanical polishing.

  Next, the covering layer 102 is formed to cover the opening of the groove 100a. The covering layer 102 is obtained by depositing a metal material on the entire surface of the substrate 200 by, for example, a sputtering method or a CVD method, and then patterning the metal material.

  Subsequently, as shown in FIG. 9B, the insulating layer 104 is formed. The insulating layer 104 is obtained, for example, by depositing an insulating material on the entire surface of the substrate 200 and then etching away portions corresponding to both ends of the drive coils 40 and 46. Next, lead conductors 42a to 42d and electrodes 56a to 56d and 58a to 58d are formed on the insulating layer 104 by photolithography. At this time, both ends of the drive coils 40 and 46 and the ends of the corresponding lead conductors 42a to 42d are physically and electrically connected.

  Subsequently, as shown in FIG. 9C, a predetermined portion of the substrate 200 is removed by anisotropic etching down to the intermediate layer 202. Next, the exposed portion of the intermediate layer 202 due to the removal of the substrate 200 is removed by dry etching. Thus, the movable portion 22 other than the mirror 48 and the insulating layer 54, the base 24 and the connecting members 38 and 44 are formed. At this time, the insulating layer 104 becomes the insulating layers 28 and 50, and the intermediate layer 202 becomes the insulating layers 30 and 52.

  Subsequently, as shown in FIG. 10A, predetermined portions of the silicon oxide film 206 and the substrate 204 are removed by etching. Thereby, the reinforcement part 26 is formed. At this time, the silicon oxide film 206 becomes the insulating layer 32.

  Subsequently, as shown in FIG. 10B, the mirror 48 and the insulating layer 54 are formed on the insulating layer 52. Thereby, the mirror structure 14 is formed. Next, one bump electrode 60 is connected on each of the electrodes 56a to 56d and 58a to 58d.

  Subsequently, as shown in (c) of FIG. 10, the permanent magnet 10 and the wiring board 12 on which the electrodes 16a to 16d and 18a to 18d are disposed on the surface 12c are prepared. Next, the wiring substrate 12 is attached on the permanent magnet 10 with an adhesive so that the main surface 10 a of the permanent magnet 10 and the surface 12 d of the wiring substrate 12 face each other.

  Next, the mirror structure 14 is positioned on the permanent magnet 10 and the wiring substrate 12. At this time, the main surface 36 a of the mirror placement portion 36 faces the main surface 10 a of the permanent magnet 10. The electrodes 56a to 56d of the support portion 20 face the electrodes 16a to 16d of the corresponding wiring substrate 12, respectively. The electrodes 58a to 58d of the support portion 20 face the electrodes 18a to 18d of the corresponding wiring substrate 12, respectively. Therefore, when viewed in the Z-axis direction, the wiring board 12 is located between the support portion 20 and the permanent magnet 10 but does not overlap the movable portion 22.

  Next, each bump electrode 60 is placed on each of the electrodes 16a to 16d and 18a to 18d to connect each bump electrode 60 with the corresponding electrodes 16a to 16d and 18a to 18d. Thereby, the drive coils 40 and 46 are electrically connected to the wiring substrate 12 through the lead conductors 42a to 42d, the electrodes 56a to 56d, 58a to 58d, the bump electrodes 60, and the electrodes 16a to 16d and 18a to 18d. Be done. By the above, the permanent magnet 10, the wiring board 12, and the mirror structure 14 are assembled, and the mirror drive device 1 is completed.

  In the present embodiment as described above, the permanent magnet 10 is opposed to the main surfaces 34a and 36a in the Z-axis direction. Therefore, since the permanent magnet 10 and the movable portion 22 are adjacent in the Z-axis direction, the permanent magnet 10 as a whole approaches the drive coils 40 and 46 disposed on the main surfaces 34 a and 36 a of the movable portion 22. Therefore, the magnetic field acting on the drive coils 40 and 46 can be sufficiently secured.

  In the present embodiment, the drive coils 40 and 46 are closer to the permanent magnet 10 in the support 20 by the lead conductors 42 a to 42 d extending from the movable part 22 to the support 20 via the connection members 38 and 44. The electrodes 56a to 56d and 58a to 58d located at the end are connected. Further, the electrodes 56 a to 56 d and 58 a to 58 d are electrically connected to the wiring substrate 12 positioned between the support portion 20 and the permanent magnet 10 when viewed in the Z-axis direction. Thus, the presence of the wiring substrate 12 between the support portion 20 and the permanent magnet 10 allows the electrodes 56a to 56d, 58a to 58d to be located at the end (surface 20a) of the support portion 20 near the permanent magnet 10. Electrical connection between 58 d and wiring board 12 is achieved. Therefore, even when the drive coils 40 and 46 are disposed on the surface (principal surface 36 a) of the movable portion 22 opposite to the mirror 48, the drive coils 40 and 46 are electrically connected to the outside. Is possible.

  In the present embodiment, the wiring substrate 12 is disposed on the major surface 10 a of the permanent magnet 10 as viewed in the Z-axis direction, but does not overlap the movable portion 22. Therefore, the wiring substrate 12 positioned between the support portion 20 and the permanent magnet 10 also functions as a spacer for separating the movable portion 22 and the permanent magnet 10 from each other. Therefore, the space for swinging the movable portion 22 can be secured by the wiring board 12. In addition, since the wiring board 12 has both the original function of supplying electricity to the drive coils 40 and 46 and the function of the spacer, it is possible to miniaturize the mirror drive device 1 as a whole.

  It is also conceivable to impart the function as a spacer to the permanent magnet 10 by causing the portion overlapping the support portion 20 in the Z-axis direction of the permanent magnet 10 to protrude toward the support portion 20. In this case, the shape of the permanent magnet 10 is complicated, and the magnetic field formed around the movable portion 22 by the permanent magnet 10 is complicated, and the drive coil 40 is disposed in the region where the magnetic flux density shows a substantially maximum value. It becomes difficult to align. However, in the present embodiment, since the wiring substrate 12 has the function of a spacer and the main surface 10a of the permanent magnet 10 has a planar shape, the magnetic field formed around the movable portion 22 by the permanent magnet 10 In the above, it is easy to identify the region where the magnetic flux density shows the substantially maximum value. Therefore, it becomes easy to position the drive coil 40 in the area concerned.

  In the present embodiment, the electrodes 56a to 56d and 58a to 58d are disposed on the surface side of the base 24 facing the permanent magnet 10 and at a position overlapping the reinforcing portion 26 when viewed from the facing direction. Therefore, when a stress or the like occurs when the wiring substrate 12 and the drive coils 40 and 46 are electrically connected, the reinforcing portion 26 mainly performs the stress or the like through the electrodes 56a to 56d and 58a to 58d and the base 24. receive. Therefore, the movable portion 22 is less susceptible to the stress and the like.

  In the present embodiment, the thickness of the support portion 20 is larger than the thickness of the movable portion 22 in the Z-axis direction. Therefore, since the strength of the support portion 20 is further enhanced, even if a stress or the like occurs when the wiring substrate 12 and the drive coils 40 and 46 are electrically connected, the movable portion 22 is further influenced by the stress or the like. It becomes difficult to receive. Therefore, breakage of the movable portion 22 can be suppressed.

  In the present embodiment, the bump electrode 60 is disposed between the wiring substrate 12 and the support portion 20, and the electrodes 16a to 16d, 18a to 18d of the wiring substrate 12 and the electrodes 56a to 56d, 58a to 58b of the support portion 20. Electrically connect with 58 d. In this case, since the bump electrode 60 exists between the permanent magnet 10 and the support portion 20, the distance between the main surface 36a of the mirror placement portion 36 and the permanent magnet 10 is further increased. Therefore, a space in which the movable portion 22 swings can be further secured.

  In the present embodiment, the covering layer 102 covers the opening of the groove 100 a. In addition, the metal material forming the covering layer 102 has a function of suppressing the diffusion of the metal material forming the drive coil 46. Therefore, it is difficult for the metal material constituting the drive coils 40 and 46 to diffuse into the insulating layer 104, and the occurrence of short circuit is prevented. Therefore, the conduction failure due to the short circuit can be eliminated. Along with this, since the drive coils 40 and 46 wound in high density are realized, a larger Lorentz force can be applied to the drive coils 40 and 46. As a result, it is possible to obtain the mirror drive device 1 in which the movable range of the mirror 48 is large.

  In the present embodiment, the metal material constituting the drive coil 46 is Cu or Au, and the metal material constituting the covering layer 102 is Al or an alloy containing Al. Although Cu or Au is a relatively easily diffused material while having a low electrical resistivity, the presence of the covering layer 102 can suppress the diffusion of these materials. In particular, since the metal material constituting the covering layer 102 is Al or an alloy containing Al, the diffusion of Cu or Au is extremely well suppressed. Therefore, the electrical resistivity of the drive coils 40 and 46 can be reduced and the occurrence of a short can be prevented.

  In the present embodiment, the wiring substrate 12 is attached to the permanent magnet 10 with an adhesive before assembling the permanent magnet 10, the wiring substrate 12 and the mirror structure 14. In this case, in manufacturing the mirror driving device 1, the mirror structure 14 may be mounted on the wiring substrate 12 so that the support portion 20 overlaps the wiring substrate 12. Therefore, when the mirror driving device 1 is manufactured, the load hardly acts on the mirror 48 with small intensity. Accordingly, since the mirror 48 is less likely to be damaged in the manufacturing process of the mirror driving device 1, the yield can be increased.

  In the present embodiment, the outer portion 34 is swingably attached to the base 24 of the support portion 20 via a pair of connecting members 38 aligned in the same straight line, and the mirror placement portion 36 is in the same straight line It is swingably attached to the outer portion 34 via a pair of connecting members 44 aligned with each other. The direction in which the pair of connecting members 44 are arranged is substantially orthogonal to the direction in which the pair of connecting members 38 are arranged, as viewed from the Z-axis direction. Move. Therefore, it becomes possible to scan the reflected light of the mirror 48 two-dimensionally.

  By the way, when the reflected light of the mirror 48 is two-dimensionally scanned, the mirror placement portion 36 is quickly swung to scan the reflected light at high speed along the first scanning direction, and the first scanning direction In order to scan the reflected light intermittently along the second scanning direction crossing (for example, substantially orthogonal to) the outer portion 34 is considered to be swung at a larger swing angle than the mirror placement portion 36. At this time, in the present embodiment, the magnetic flux density of the magnetic field formed on the main surface 10a side of the permanent magnet 10 and around the movable portion 22 by the combination of the magnetic poles 10A1 and 10B1 and the magnetic poles 10B2 and 10C2 has a substantially maximum value Has a portion located in the area shown. Therefore, it is possible to increase the Lorentz force acting on the drive coil 40 while reducing the magnitude of the current supplied to the drive coil 40 disposed in the outer portion 34. Therefore, low power consumption can be achieved while increasing the swing angle of the outer portion 34.

  In the present embodiment, when viewed from the Z-axis direction, the drive coil 40 is in the above-described region where the magnetic flux density has a substantially maximum value among the magnetic fields formed around the movable portion 22 by the magnetic portions 10A to 10C forming the Halbach array. Has a portion located at Therefore, the magnetic flux density in the vicinity of the drive coil 40 is further increased by the magnetic portions 10A to 10C forming the Halbach arrangement.

  As mentioned above, although embodiment of this invention was described in detail, you may add various deformation | transformation to said embodiment within the range of the summary of this invention. For example, the mirror drive device 1 may not have the electrodes 18a to 18d and 58a to 58d functioning as dummy electrodes. In this case, for example, as shown in FIG. 11, two electrodes 16a and 16d are disposed on the surface 12c of one second portion 12b of the wiring substrate 12, and the other second portion 12b of the wiring substrate 12 is Two electrodes 16b and 16c may be disposed on the surface 12c. At this time, the electrodes 56a to 56d disposed on the surface 20a of the support portion 20 are disposed at positions corresponding to the electrodes 16a to 16d, as shown in FIG. As described above, when the electrodes 18a to 18d and 58a to 58d are arranged without being biased to one side, the mirror structure 14 is a permanent magnet when the mirror structure 14 is disposed on the permanent magnet 10 and the wiring substrate 12 It can suppress that it inclines with respect to 10 and the wiring board 12.

  Although not shown, two electrodes 16 a and 16 d are disposed on the surface 12 c of one first portion 12 a of the wiring substrate 12, and two electrodes 16 a and 16 d are disposed on the surface 12 c of the other first portion 12 a of the wiring substrate 12. Two electrodes 16b and 16c may be arranged. Similarly, although not shown, one of the electrodes 16 a to 16 d may be disposed on each of the portions 12 a and 12 b of the wiring substrate 12. Also in these cases, the electrodes 56a to 56d disposed on the surface 20a of the support portion 20 are disposed at positions corresponding to the electrodes 16a to 16d.

  The shape of the wiring board 12 may not have an annular shape. For example, as shown in FIG. 13, the wiring board 12 may be configured by two members 12A and 12B. Both members 12A and 12B shown in FIG. 13A have a C-shape. Both members 12A and 12B shown in (b) of FIG. 13 have a linear shape. That is, in the present specification, “frame-like” includes not only an endless annular frame member itself but also a set of members consisting of a plurality of portions obtained by cutting at least a part of the endless annular frame member. The frame-shaped wiring board 12 may extend along the periphery of the permanent magnet 10.

  As shown in FIG. 13, electrodes 16a to 16d are disposed on the surface 12c of the member 12A. Electrodes 18a to 18d are disposed on the surface 12c of the member 12B. The wiring board 12 may be composed of three or more members. Even when the wiring board 12 is formed of a plurality of members, the wiring board 12 is located between the support portion 20 and the permanent magnet 10, and between the movable portion 22 and the permanent magnet 10. Is not located. Thus, a space for swinging the movable portion 22 can be provided between the movable portion 22 and the permanent magnet 10, and the swing of the movable portion 22 is not inhibited by the wiring board 12.

  The two members 12A and 12B shown in FIG. 13 are arranged in one direction (X-axis direction) orthogonal to the opposing direction (Z-axis direction) of the main surface of the movable portion 22, and the Z-axis direction and one direction It may extend in another direction (Y-axis direction) orthogonal to both (X-axis direction). The plurality of electrodes 16a to 16d disposed on the member 12A and the plurality of electrodes 18a to 18d disposed on the member 12B are opposed to each other in the X-axis direction. The electrodes 16a to 16d are aligned in the Y-axis direction. The electrodes 18a to 18d are aligned in the Y-axis direction. Also in this case, a space for swinging the movable portion 22 can be provided between the pair of members 12A and 12B, and the swing of the movable portion 22 is not inhibited by the wiring board 12. In addition, the support portion 20 is supported in a well-balanced manner by the plurality of electrodes 16a to 16d and 18a to 18d which are paired in the first direction. If it has a pair of parts or members opposed in the X-axis direction and extending in the Y-axis direction, even in the case of an endless annular frame member, a plurality of portions in which at least a part of the endless annular frame member is cut Even in the case of a pair of members, the effect is exerted. In addition, even in the case where the electrode is a dummy electrode, the effect is exhibited.

  In addition to the wiring substrate 12, the base portion 24 and the reinforcing portion 26 may have a frame shape, or the support portion 20 may have a frame shape as a whole. The “frame-like” referred to here also includes not only an endless annular frame member itself but also a set of members consisting of a plurality of portions in which at least a part of the endless annular frame member is cut.

With regard to the structure in the vicinity of the drive coils 40 and 46, for example, as shown in FIG. 14, instead of covering the opening of the groove 100a with the covering layer 102, the entire surface of the substrate 100 is covered with the insulating layer 106 and 108. It is also good. The insulating layer 106 may be made of, for example, SiN. The thickness of the insulating layer 106 may be set to, for example, about 50 nm or more. The thickness of the insulating layer 106 may be set to, for example, about 500 nm or less. In this case, the insulating layer 106 suppresses the diffusion of the metal material forming the drive coil 46. The insulating layer 108 may be made of, for example, SiO ₂ . The thickness of the insulating layer 108 may be set to, for example, 500 nm or more.

  Although the linear connecting member 38 has been described as an example in the above embodiment, the configuration of the connecting member 38 is not limited to this, and may be another shape. As another example of the connection member 38, the connection member 38 which exhibits a serpentine shape is shown in FIGS. Here, as shown in FIG. 16, the connecting member 44 linearly extends along the X-axis direction toward the outer portion 34, and after being bifurcated, extends along the Y-axis direction. Good. In this case, the length of the connecting member 44 in the X-axis direction can be shortened.

  As shown in FIG. 17, a pair of beam members 62 may be disposed on the major surface 34 b of the outer portion 34. The beam member 62 is a protrusion extending along a direction in which the pair of connecting members 44 are arranged (a straight line orthogonal to a straight line in which the pair of connecting members 38 are arranged) when viewed in the Z-axis direction in FIG. The height of the beam member 62 may be set to be equal to the height of the reinforcing portion 26. In this case, since the load generated on the outer side portion 34 by the swinging of the mirror placement portion 36 is supported by the beam member 62, it is possible to suppress the deflection generated on the outer side portion 34. As a result, the strength of the outer portion 34 can be improved. The shape of the beam member 62 may not be as thin as a protrusion if the strength of the outer portion 34 can be improved. That is, the beam member 62 may not extend from the vicinity of one end of the outer portion 34 to the vicinity of the other end in the direction in which the pair of connecting members 44 are arranged. For example, in the direction in which the pair of connecting members 44 are arranged, the plurality of beam members 62 may be arranged in a mutually separated state.

  As long as the magnetic field can be formed intensively on the main surface 10a side of the permanent magnet 10 and in the vicinity of the movable portion 22, the permanent magnet 10 does not have to be constituted by the magnetic portions 10A to 10C forming the Halbach arrangement. . The permanent magnet 10 which concerns on another example is demonstrated with reference to FIGS. 18-21. The permanent magnet 10 according to another example has magnetic parts 10F to 10L.

  The magnetic portion 10F and the magnetic portion 10G are adjacent to each other along a first direction (X-axis direction) orthogonal to the opposing direction (Z-axis direction) of the main surface of the movable portion 22. The magnetic portion 10K and the magnetic portion 10L are adjacent to each other along the first direction (X-axis direction). The magnetic portions 10H, 10J, and 10I are arranged in this order so as to be adjacent to each other along a second direction (Y-axis direction) orthogonal to both the facing direction and the first direction.

  The magnetic units 10H to 10J are located between the magnetic unit 10G and the magnetic unit 10K in the first direction, and are sandwiched by the magnetic unit 10G and the magnetic unit 10K. Therefore, the magnetic parts 10H to 10J are adjacent to the magnetic parts 10G and 10K in the first direction.

  A boundary surface 10M is formed by the surface where the magnetic portion 10F and the magnetic portion 10G are in contact with each other. A boundary surface 10N is formed by a surface where the magnetic portion 10G and the magnetic portions 10H to 10J are in contact with each other. A boundary surface 10O is formed by a surface where the magnetic portion 10H and the magnetic portion 10J are in contact with each other. A boundary surface 10P is formed by the surface where the magnetic portion 10I and the magnetic portion 10J are in contact with each other. A boundary surface 10Q is formed by the surfaces where the magnetic portions 10K and the magnetic portions 10H to 10J are in contact with each other. A boundary surface 10R is formed by a surface where the magnetic portion 10K and the magnetic portion 10L are in contact with each other. The boundary surfaces 10M, 10N, 10Q, and 10R are substantially orthogonal to the X-axis direction. The boundary surfaces 10O and 10P are substantially orthogonal to the Y-axis direction.

  As shown in (a) of FIG. 19 and FIG. 21, the magnetic portion 10F has magnetic poles 10F1 and 10F2 of different polarities. The magnetic pole 10F1 is an N pole and is located on the main surface 10a side. The magnetic pole 10F2 is a south pole and is located on the main surface 10b side. That is, the direction of magnetization of the magnetic portion 10F is directed from the main surface 10b side to the main surface 10a side.

  The magnetic portion 10G has magnetic poles 10G1 and 10G2 of mutually different polarities, as shown in (a) of FIG. 19 and FIG. The magnetic pole 10G1 is a south pole and is located on the main surface 10a side. The magnetic pole 10G2 is an N pole and is located on the main surface 10b side. That is, the direction of magnetization of the magnetic portion 10G is from the main surface 10a side to the main surface 10b side.

  As shown in (a) of FIG. 20 and (b) of FIG. 21, the magnetic portion 10H has magnetic poles 10H1 and 10H2 of different polarities. The magnetic pole 10H1 is a south pole and is located on the main surface 10a side. The magnetic pole 10H2 is an N pole and is located on the main surface 10b side. That is, the direction of the magnetization of the magnetic portion 10H is from the main surface 10a side to the main surface 10b side.

  As shown in (a) of FIG. 20 and (a) of FIG. 21, the magnetic portion 10I has magnetic poles 10I1 and 10I2 of different polarities. The magnetic pole 10I1 is an N pole and is located on the main surface 10a side. The magnetic pole 10I2 is a south pole and is located on the main surface 10b side. That is, the magnetization direction of the magnetic portion 10I is directed from the main surface 10b side to the main surface 10a side.

  The magnetic portion 10J is not magnetized as shown in (a) of FIG. 19 and (a) of FIG. Therefore, the magnetic moments cancel each other in the magnetic portion 10J, and the magnetization in the magnetic portion 10J is substantially zero.

  The magnetic portion 10K has magnetic poles 10K1 and 10K2 of different polarities, as shown in (a) of FIG. 19 and FIG. The magnetic pole 10K1 is an N pole and is located on the main surface 10a side. The magnetic pole 10K2 is a south pole and is located on the main surface 10b side. That is, the direction of magnetization of the magnetic portion 10K is directed from the main surface 10b side to the main surface 10a side.

  The magnetic portion 10L has the magnetic poles 10L1 and 10L2 of different polarities, as shown in (a) of FIG. 19 and FIG. The magnetic pole 10L1 is a south pole and is located on the main surface 10a side. The magnetic pole 10L2 is an N pole and is located on the main surface 10b side. That is, the magnetization direction of the magnetic portion 10L is directed from the main surface 10a side to the main surface 10b side.

  From the above, on the main surface 10a, a set of the magnetic pole 10F1 (N pole) and the magnetic pole 10G1 (S pole) aligned in the first direction adjacent to each other appears. On the main surface 10a, a set of a magnetic pole 10K1 (N pole) and a magnetic pole 10L1 (S pole) arranged adjacent to each other in the first direction appears. Therefore, a magnetic field is formed intensively on the main surface 10 a side of the permanent magnet 10 and in the vicinity of the movable portion 22. The magnetic flux density in the magnetic field is the main surface 10a side of the permanent magnet 10 in the first direction (X-axis direction) as shown in (b) of FIG. 19 and a set of the magnetic pole 10F1 and the magnetic pole 10G1. It tends to be particularly large in the vicinity of the boundary (boundary surface 10M) and in the vicinity of the boundary (boundary surface 10R) of the pair of the magnetic pole 10K1 and the magnetic pole 10L1 on the main surface 10a side of the permanent magnet 10 It is in. The magnetic flux density in the magnetic field is the main surface 10a side of the permanent magnet 10 in the second direction (Y-axis direction) as shown in (b) of FIG. 20, and the magnetic pole 10H1 and the magnetic pole 10I1 are In particular, the distance between the magnetic portions 10J and the distance between the magnetic portions 10J increases.

  Also in the case where the permanent magnet 10 according to the other example described above is used, the drive coil 40 is a first magnetic flux density having a substantially maximum value among magnetic fields formed around the movable portion 22 by the magnetic portions 10F to 10L. It has a portion located in the area. Therefore, a magnetic flux density larger in the vicinity of the drive coil 40 can be formed by the magnetic portions 10F to 10L arranged in a specific state.

  On the other hand, when the permanent magnet 10 according to the other example described above is used, the drive coil 46 has a portion located in the second area other than the first area. In other words, the drive coil 46 is located between the interface 10M and the interface 10R when viewed from the opposite direction. When a current of a frequency corresponding to the resonance frequency of the mirror placement portion 36 is supplied to the drive coil 46 and the reflected light is scanned at high speed along the first scanning direction, the mirror placement portion 36 oscillates due to resonance. The large Lorentz force may not act on the drive coil 46 in order to swing the mirror placement portion 36. Therefore, when the drive coil 46 has a portion located in the second area, the drive coil 40 can be easily located in the first area. Therefore, the Lorentz force acting on the drive coil 40 can be further increased.

  Although the permanent magnet 10 which concerns on said other example had the magnetic part 10J which is not magnetized, it is not necessary to have the said magnetic part 10J, as FIG. 22 shows. In this case, the magnetic portion 10H and the magnetic portion 10I are adjacent along the second direction (Y-axis direction), and the boundary surface 10S is formed by the surface where the magnetic portion 10H and the magnetic portion 10I are in contact with each other. .

  The shape of the mirror 48 may be circular or polygonal (for example, square or octagonal).

  The shape of the bump electrode 60 may be, for example, a spherical shape, a hemispherical shape, a columnar shape, a conical shape, or a shape in which these are partially cut away.

  The permanent magnet 10 may be obtained by magnetizing a ferromagnetic material or a ferrimagnetic material.

  The wiring substrate 12 may not be directly mounted on the major surface 10 a of the permanent magnet 10 as long as the wiring substrate 12 is disposed between the support portion 20 and the permanent magnet 10. Also in this case, the wiring board 12 located between the support portion 20 and the permanent magnet 10 functions as a spacer for separating the movable portion 22 and the permanent magnet 10 from each other. Therefore, the space for swinging the movable portion 22 can be secured by the wiring board 12.

  In the manufacturing process of the mirror drive device 1, the mirror 48 may be formed after the drive coils 40 and 46 are formed.

  In the manufacturing process of the mirror drive device 1, the permanent magnet 10, the wiring board 12 and the mirror structure 14 may be assembled in an order different from that of the above embodiment. For example, first, one bump electrode 60 is connected on each of the electrodes 56 a to 56 d and 58 a to 58 d of the obtained mirror structure 14. Next, the wiring substrate 12 not attached to the permanent magnet 10 is prepared, and the electrodes 16 a to 16 d and 18 a to 18 d of the wiring substrate 12 are connected to the respective bump electrodes 60 respectively. Next, the surface 12 d of the wiring substrate 12 is connected to the major surface 10 a of the permanent magnet 10 with an adhesive or the like.

  The electrical connection between the electrodes 16a to 16d and 18a to 18d and the electrodes 56a to 56d and 58a to 58d is not limited to the bump electrode 60. For example, a conductive adhesive film may be used.

DESCRIPTION OF SYMBOLS 1 ... Mirror drive device, 10 ... Permanent magnet, 10A-10C ... Magnetic part, 10a, 10b ... Principal surface, 12 ... Wiring board, 14 ... Mirror structure, 16a-16d ... Electrode, 18a-18d ... Electrode, 20 ... Support part 22 movable part 24 base part 26 reinforcement part 36 mirror arrangement part 36a, 36b main surface 38, 44 connection member 40, 46 drive coil 42a to 42d lead conductor , 48: mirror, 56a to 56d: electrode, 58a to 58d: electrode, 60: bump electrode, 100: base material, 100a: groove portion, 102: coating layer, 104: insulating layer.

Claims (16)

A frame-shaped support portion,
A movable portion having first and second main surfaces located inside and opposite to the support portion, and pivotally supported by the support portion via a coupling member;
A magnetic body positioned so as to face the support portion and the second main surface in an opposite direction in which the first and second main surfaces face each other, and forming a magnetic field around the movable portion;
And a wiring substrate disposed between the support portion and the magnetic body in the opposing direction so that the movable portion is inward when viewed from the opposing direction.
The movable portion is
A substrate including the first and second main surfaces;
A mirror disposed on the first main surface side;
A drive coil disposed on the second main surface side so as to face the magnetic body,
The support portion is
A base having a frame shape and connected to the connection member;
A reinforcing portion having a frame shape and extending from the base in a direction away from the magnetic body and the wiring board in the opposing direction;
It has a first and a second electrode arranged on the surface side of the base facing the magnetic body and facing the movable portion as viewed from the facing direction.
The reinforcing portion, the base portion, the first electrode, the wiring board, and the magnetic body are disposed to overlap in this order in the opposing direction, and the reinforcing portion, the base portion, The second electrode, the wiring board, and the magnetic body are arranged to overlap in this order in the facing direction,
The drive coil is electrically connected to at least one of the first and second electrodes by a lead conductor extending from the movable portion to the support portion via the connection member.
The mirror drive device, wherein the first and second electrodes are electrically and physically connected to the wiring substrate.   The mirror drive device according to claim 1, wherein the wiring substrate is disposed on a surface of the magnetic body facing the second main surface.   The mirror drive device according to claim 1 or 2, wherein in the opposite direction, the total thickness of the base and the reinforcing portion is larger than the thickness of the movable portion.   The bump electrode which is arrange | positioned between the said wiring board and the said support part, and connects the said wiring board and the said, 1st and 2nd electrode is further provided in any one of Claims 1-3. Mirror drive. The base material includes a groove portion located on the second main surface side and extending in a spiral shape as viewed from a direction orthogonal to the second main surface,
5. The drive coil according to claim 1, wherein the drive coil is formed of a first metal material disposed in the groove, and is spirally wound as viewed in a direction orthogonal to the second main surface. The mirror drive device according to any one of the above. The movable portion is
A covering layer made of a second metal material which covers the opening of the groove and suppresses the diffusion of the first metal material;
The mirror drive device according to claim 5, further comprising: an insulating layer disposed on the second major surface and the covering layer. The first metal material is Cu or Au,
The mirror drive device according to claim 6, wherein the second metal material is Al or an alloy containing Al.   The mirror drive device according to claim 5, wherein the movable portion further includes an insulating layer covering an opening of the groove portion. The material constituting the insulating layer is SiN,
The mirror drive device according to claim 8, wherein a thickness of the insulating layer is 50 nm or more. The movable portion is
A mirror placement portion including a portion of the substrate on which the mirror is disposed;
An outer portion including a frame-like portion surrounding the outer periphery of the mirror placement portion in the base material;
And two said drive coils,
The outer portion is swingably supported by the support portion via the connection member,
The mirror arrangement portion is swingably supported on the outer portion through another connection member extending in a direction intersecting the connection member,
Each of the two drive coils is spirally wound as viewed in a direction orthogonal to the second main surface,
One drive coil of the two drive coils is disposed on the side of the second main surface of the mirror arrangement portion,
The other drive coil of the two drive coils is disposed on the second main surface side of the outer side,
On the surface of the magnetic body on the side facing the second main surface, a pair of magnetic poles consisting of an S pole and an N pole arranged adjacent to each other in the direction along the surface appears.
10. The other drive coil according to any one of claims 1 to 9, wherein a portion of the magnetic field formed around the movable portion by the set of magnetic poles has a portion located in a first region where the magnetic flux density exhibits a substantially maximum value. The mirror drive device according to any one of the preceding claims. The magnetic body has first to third magnetic portions arranged in order to form a Halbach arrangement along a predetermined direction,
The mirror drive device according to claim 10, wherein the other drive coil has a portion located in the first area. The magnetic body includes first and second magnetic portions adjacent along a first direction orthogonal to the opposing direction, and third and fourth magnetic portions adjacent along the first direction. And fifth and sixth magnetic portions aligned along a second direction orthogonal to both the opposing direction and the first direction,
The fifth and sixth magnetic portions are located between the second magnetic portion and the third magnetic portion, and are adjacent to the second and third magnetic portions in the first direction. ,
The magnetization directions of the first, third and fifth magnetic parts are all directed from the first main surface side to the second main surface side,
The magnetization directions of the second, fourth and sixth magnetic parts are all directed from the second main surface side to the first main surface side,
The mirror drive device according to claim 10, wherein the other drive coil has a portion located in the first area.   The mirror drive device according to claim 12, wherein the one drive coil has a portion located in a second area other than the first area. Preparing a wiring board having a frame shape;
A frame-shaped support portion, and a movable portion having first and second main surfaces located on the inner side of the support portion and opposed to each other and swingably supported by the support portion via a connection member The movable portion includes a base including the first and second main surfaces, a mirror disposed on the first main surface, and a drive coil disposed on the second main surface. And the support portion is in the shape of a frame, and is in the shape of a frame connected to the base connected to the connection member, in the opposing direction in which the first and second main surfaces are opposed. A reinforcing portion extending from the base in a direction from the second main surface toward the first main surface, and a surface side of the base opposite to the reinforcing portion and in the opposite direction And the first and second electrodes disposed to face each other with the movable portion facing each other as viewed from Providing a mirror structure electrically connected to at least one of the first and second electrodes by a lead conductor extending from the movable portion to the support portion via the connection member; ,
Preparing a magnetic body that forms a magnetic field around the movable portion;
The magnetic body is disposed to face the support portion and the second main surface in the facing direction, and the reinforcing portion, the base, the first electrode, the wiring board, and the magnetic body Are disposed so as to overlap in this order in the opposing direction, and the reinforcing portion, the base, the second electrode, the wiring board, and the magnetic body are arranged so as to overlap in this opposing direction in this order A method of manufacturing a mirror drive device including assembling the mirror structure, the magnetic body, and the wiring board, and electrically and physically connecting the first and second electrodes to the wiring board.   After preparing the mirror structure and before electrically connecting the wiring substrate and the drive coil, the method further includes disposing the wiring substrate on a part of the surface of the magnetic body. The method according to 14. The method further includes disposing a bump electrode on the first and second electrodes after preparing the mirror structure and before electrically connecting the wiring substrate and the drive coil.
When the wiring substrate and the drive coil are electrically connected, the mirror structure and the bump electrode, the magnetic body, and the wiring substrate are connected by connecting the bump electrode to the wiring substrate. The method according to claim 14 or 15, which is assembled.

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