JP5520566B2 - Planar actuator and manufacturing method thereof - Google Patents

Description

  The present invention relates to a planar actuator and a method for manufacturing the same, and more particularly to a planar actuator and a method for manufacturing the same that can secure a large mirror installation space and can secure a driving force of a movable part.

Conventionally, as an actuator having a structure in which a plate-like movable part is pivotally supported on a frame-like fixed part, for example, using a semiconductor manufacturing technique, a silicon substrate is anisotropically etched to form a frame-like fixed part. A flat movable part and a torsion bar that pivotally supports the movable part are integrally formed, and a drive coil is provided on the movable part, and a static magnetic field is generated such as a permanent magnet that applies a static magnetic field to the drive coil of the movable part. There is known an electromagnetic drive type planar actuator that provides a means for swinging a movable part using Lorentz force generated by the interaction between a magnetic field generated in a drive coil by energization and a static magnetic field generated by a static magnetic field generating means. Yes.
Such an actuator is applied to, for example, an optical scanner that deflects and scans a light beam by providing a mirror on a movable part.

  As such an actuator, conventionally, a thin film coil is laid along the peripheral edge of the movable part on the front and back surfaces of the movable part, and the stress generated in the movable part is balanced between the front and back surfaces of the movable part. Thus, a technique for preventing the warp and deformation of the movable part and improving the driving force is disclosed (for example, see Patent Document 1).

  In addition, as another actuator, a technique is disclosed in which an inclined surface is formed on the outer periphery of the movable portion, and a drive coil is provided on the inclined surface to increase the rigidity of the movable portion (for example, Patent Document 2). reference).

JP 2004-264684 A JP 2007-271787 A

  However, the actuator disclosed in Patent Document 1 has a problem that when the mirror is installed on the movable part, the drive coil becomes an obstacle and a large installation space for the mirror cannot be secured. Further, in the actuator disclosed in Patent Document 2, an inclined surface is formed on the movable part, and therefore, when the movable part swings, the balance is poor and the driving force is reduced. have.

  The present invention has been made in view of the above points, and provides a planar actuator capable of ensuring a large mirror installation space and ensuring the driving force of the movable portion, and a method of manufacturing the same. It is the purpose.

In order to achieve the above object, a planar actuator according to the invention described in claim 1 includes a frame-shaped fixing portion,
Inside the fixed part, a flat plate-like movable part supported movably through a torsion bar;
At least a portion is formed on the outer side surface of the movable portion and a driving coil for driving the movable part,
The drive coil is formed by alternately laminating patterned conductive material layers and insulating material layers .
According to a second aspect of the present invention, in the first aspect, the outer surface is orthogonal to the front surface or the rear surface of the movable part.

According to a third aspect of the present invention, in the first or second aspect , the torsion bar is formed so as to have a height dimension smaller than a height dimension of the movable part, and the outside of the movable part Form a step with the same height as the torsion bar,
The drive coil is formed on an outer surface of the movable part and an upper surface of the torsion bar parallel to the surface of the movable part .

According to a fourth aspect of the invention, according to claim 1 or claim 2, wherein the drive coil has an outer side surface of the movable portion, and the side surfaces parallel to the outer surface of the movable portion of the torsion bar, the fixed characterized in that it is formed on an inner surface facing the outer surface of the movable portion of the part.

According to a fifth aspect of the present invention, there is provided a planar actuator manufacturing method comprising a plate-like movable portion that is rotatably supported via a torsion bar and driven by a drive coil inside a frame-like fixed portion. In a planar actuator manufacturing method for manufacturing an actuator,
Etching from the surface side of the first wafer made of silicon to remove the parts other than the fixed part, the torsion bar and the movable part, and slightly remove the part corresponding to the torsion bar from the movable part Removing to reduce the height dimension;
Forming an outer side surface of the movable portion, the coil wire constituting the drive coil in an upper surface parallel to the surface of the movable portion of the torsion bar,
It is characterized by having.

According to a sixth aspect of the present invention, there is provided a planar actuator manufacturing method comprising a flat plate-like movable portion that is rotatably supported via a torsion bar and driven by a drive coil inside a frame-like fixed portion. In a planar actuator manufacturing method for manufacturing an actuator,
Etching from the surface side of the first wafer made of silicon, removing the parts other than the fixed part, the torsion bar and the movable part;
Coils constituting an outer side surface of the movable portion, and the side surfaces parallel to the outer surface of the movable portion of the torsion bar, the drive coil and an inner surface facing the outer surface of the movable portion of the fixed portion Forming a wiring; and
It is characterized by having.

According to the invention described in claim 1, since at least a part of the driving coil is to be formed on the outer side surface of the movable portion, there is no need to form a drive coil on the front and back surfaces of the movable part, as a result The mirror can be installed over almost the entire area of the movable part, and a large space for installing the mirror can be secured. In addition, since the film stress due to the formation of the drive coil does not act on the front and back surfaces of the movable part, it is possible to reduce the warp and deformation of the movable part, and it is possible to secure a sufficient driving force with a small current.

According to the third aspect of the present invention, since the drive coil is formed on the outer surface of the movable part and the upper surface of the torsion bar, it is not necessary to form the drive coil on the front and back surfaces of the movable part, and the mirror A large space can be secured. In addition, warping and deformation of the movable part can be reduced, and a sufficient driving force can be ensured with a small current.

According to the invention described in claim 4, the outer side surface of the movable portion of the driving coil, so that so as to form on the inner surface of the side and the fixed portion of the torsion bar, the drive coils on the front and back surfaces of the movable portion forming Therefore, a large space for installing the mirror can be secured. In addition, warping and deformation of the movable part can be reduced, and a sufficient driving force can be ensured with a small current.

According to the invention of claim 5, since so as to form a coil wire constituting the drive coil on the upper surface of the outer side and the torsion bar of the movable portion, to form a readily drive coil by the wafer manufacturing process In addition, it is not necessary to form drive coils on the front and back surfaces of the movable part, a large space for installing the mirror can be secured, and warping and deformation of the movable part can be reduced. A sufficient driving force can be ensured with a small current.

According to the invention of claim 6, the outer side surface of the movable portion, so that so as to form a coil wire constituting the drive coil on the inner surface of the side and the fixed portion of the torsion bar, easily by a wafer production process A drive coil can be formed, and it is not necessary to form a drive coil on the front and back surfaces of the movable part, so that a large space for installing a mirror can be secured, and warping and deformation of the movable part can be reduced. In addition, a sufficient driving force can be secured with a small current.

1 is a schematic plan view showing a first embodiment of a planar actuator according to the present invention. It is a perspective view of the movable part which shows 1st Embodiment of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the 1st wafer which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 1st layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the through-hole electroconductive part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 2nd layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the through-hole electroconductive part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 3rd layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the 2nd wafer which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the oxide film which shows the manufacturing method of the planar type actuator which concerns on this invention. It is a perspective view of the movable part which shows 2nd Embodiment of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the 1st wafer which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 1st layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the through-hole electroconductive part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 2nd layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the through-hole electroconductive part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the 3rd layer coil wiring formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the through-hole electroconductive part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the terminal part formation process which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the 2nd wafer which shows the manufacturing method of the planar type actuator which concerns on this invention. It is explanatory drawing of the etching process of the oxide film which shows the manufacturing method of the planar type actuator which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a first embodiment of a planar actuator according to the present invention. As shown in FIG. 1, the planar actuator 1 of this embodiment includes a frame-shaped fixing portion 2 installed on a device substrate (not shown). Inside the fixed portion 2, a movable portion 4 is swingably supported via a torsion bar 3. A step portion 5 is formed on the lower outer periphery of the movable portion 4, and the upper surface of the step portion 5 is formed to have the same height as the upper surface of the torsion bar 3. The fixed portion 2, the movable portion 4, and the torsion bar 3 are integrally formed.

  Further, in the present embodiment, as shown in FIG. 2, a drive coil 6 for driving the movable part 4 is provided on the outer surface of the movable part 4. The torsion bar 3 is configured to be drawn around the fixing portion 2 through the upper surface. Further, around the fixed portion 2, two pairs of static magnetic field generating members (not shown) arranged with the opposite magnetic poles facing each other across the movable portion 4 are arranged. The static magnetic field generating member may be a permanent magnet or an electromagnet.

  Next, a method for manufacturing the planar actuator of the present invention will be described.

  First, as shown in FIG. 3, the surface of the first wafer 10 is patterned in a state where the second wafer 12 is bonded to the back surface of the first wafer 10 made of single crystal silicon via the oxide film 11. Then, the parts other than the fixed part 2, the movable part 4 and the torsion bar 3 are removed, and the part corresponding to the torsion bar 3 is removed so that the height dimension is slightly smaller than the movable part 4.

  Next, as shown in FIG. 4, a coil wiring 13 made of a conductive material and constituting the drive coil 6 is formed on the outer peripheral portion of the movable portion 4 and the upper surface portion of the torsion bar 3.

  Hereinafter, a method for forming the coil wiring 13 will be described in more detail.

  As shown in FIG. 5, first, a conductive material is coated on the surface of the first wafer 10, patterned, and then the excess portion of the conductive material is removed by etching. A coil wiring 13 serving as a first layer is formed on the upper surface portion of the torsion bar 3.

  Next, after coating the surface of the first layer coil wiring 13 with an insulating material, coating with a conductive material and patterning, as shown in FIG. A through-hole conductive portion 14 is formed in a portion corresponding to the end portion. Subsequently, similarly, an insulating material is coated, and then a conductive material is coated and patterned to form a coil wiring 13 as a second layer as shown in FIG.

  Thus, as shown in FIG. 8, the through-hole conductive portion 14 is formed, and as shown in FIG. 9, the third-layer coil wiring 13 and the terminal portion 15 are formed to form three turns. The coil wiring 13 is formed. The coil wiring 13 can be formed in an arbitrary number of turns by the above method.

  Thereafter, as shown in FIG. 10, portions other than the fixed portion 2 are removed by patterning and etching the back side of the second wafer 12. Subsequently, as shown in FIG. 11, the planar type actuator is formed by etching the oxide film 11 between the first wafer 10 and the second wafer 12 and removing portions other than the fixed portion 2. The

  Next, the operation of this embodiment will be described.

  Since the driving principle of the planar actuator 1 is described in detail in, for example, Japanese Patent No. 2722314, etc., a brief description will be given below using an optical scanner as an example.

  When a current is passed through the drive coil 6 of the movable part 4, a magnetic field is generated, and a Lorentz force is generated by the interaction between this magnetic field and the static magnetic field generated by the static magnetic field generating means, and the movable part 4 parallel to the axial direction of the torsion bar 3. Rotational forces in opposite directions are generated on opposite sides of the movable portion 4, and the movable portion 4 is rotated to a position where the rotational force and the restoring force of the torsion bar 3 are balanced.

  Then, by passing a direct current through the drive coil 6, the movable portion 4 is stopped at a rotation position corresponding to the amount of drive current, whereby the light beam can be deflected in a desired direction by the reflection mirror.

  On the other hand, when an alternating current is passed through the drive coil 6, the movable part 4 swings, and the light beam can be deflected and scanned by the reflection mirror. Since the rotational force for rotating the movable part 4 is proportional to the drive current value supplied to the drive coil 6, the swing angle (light beam) of the movable part 4 is controlled by controlling the drive current value supplied to the drive coil 6. Can be controlled. In the present embodiment, the operation has been described by taking the case of an optical scanner as an example. However, the present invention can be applied to other than the optical scanner.

  As described above, in the present embodiment, since the drive coil 6 is formed on the outer surface of the movable part 4, it is not necessary to form the drive coil 6 on the front and back surfaces of the movable part 4, As a result, it is possible to install a mirror over almost the entire area of the movable portion 4, and to secure a large space for installing the mirror. In addition, since the film stress due to the formation of the drive coil 6 does not act on the front and back surfaces of the movable portion 4, warpage and deformation of the movable portion 4 can be reduced, and sufficient driving force can be secured with a small current. Can do.

  Next, a planar actuator according to a second embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 12, drive coils 6 for driving the movable portion 4 are provided on the outer surface of the movable portion 4, the side surface of the torsion bar 3, and the inner peripheral surface of the fixed portion 2. Other configurations are the same as those of the first embodiment.

  Next, a method for manufacturing the planar actuator of the present invention will be described.

  First, as shown in FIG. 13, the surface of the first wafer 10 is patterned in a state where the second wafer 12 is bonded to the back surface of the first wafer 10 made of single crystal silicon via the oxide film 11. Then, parts other than the fixed part 2, the movable part 4 and the torsion bar 3 are removed.

  Next, as shown in FIG. 14, the coil wiring 13 made of a conductive material is formed on the outer peripheral portion of the movable portion 4 and the upper surface portion of the torsion bar 3.

  Hereinafter, a method for forming the coil wiring 13 will be described in more detail. In the following description, only the upper half of the fixed portion 2 and the movable portion 4 will be illustrated and described for convenience.

  As shown in FIG. 15, first, a conductive material is coated on the surface of the first wafer 10, patterned, and then the excess conductive material is removed by etching. A coil wiring 13 serving as a first layer is formed on the side surface of the bar 3 and the inner side surface portion of the fixing portion 2.

  Next, after coating an insulating material on the surface of the coil wiring 13 of the first layer, a conductive material is coated and patterned, so that the coil wiring 13 of the first layer is formed as shown in FIG. A through-hole conductive portion 14 is formed in a portion corresponding to the end portion. Subsequently, similarly, an insulating material is coated, and then a conductive material is coated and patterned to form a coil wiring 13 as a second layer as shown in FIG.

  Then, as shown in FIG. 18, the through-hole conductive portion 14 is formed, and as shown in FIG. 19, the third-layer coil wiring 13 is formed. Further, as shown in FIG. 20, after the through-hole conductive portion 14 is formed, the terminal portion 15 is formed in the fixed portion 2 as shown in FIG. 21, whereby the coil wiring 13 for three turns is formed. Is.

  Thereafter, as shown in FIG. 22, parts other than the fixing portion 2 are removed by patterning and etching the back side of the second wafer 12. Subsequently, as shown in FIG. 23, the planar film type actuator is formed by etching the oxide film 11 between the first wafer 10 and the second wafer 12 and removing portions other than the fixed portion 2. The

  As described above, in this embodiment as well, as in the first embodiment, the drive coil 6 is formed on the outer surface of the movable portion 4, so that the mirror is provided over almost the entire area of the movable portion 4. It can be installed, and a large space for installing the mirror can be secured. In addition, warping and deformation of the movable portion 4 can be reduced, and a sufficient driving force can be secured with a small current.

  The present invention is not limited to the above embodiments, and various modifications can be made based on the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Planar type actuator 2 Fixed part 3 Torsion bar 4 Movable part 5 Step part 6 Drive coil 10 1st wafer 11 Oxide film 12 2nd wafer 13 Coil wiring 14 Through-hole conductive part 15 Terminal part

Claims (6)

A frame-shaped fixing part;
Inside the fixed part, a flat plate-like movable part supported movably through a torsion bar;
At least a portion is formed on the outer side surface of the movable portion and a driving coil for driving the movable part,
The drive coil is a planar actuator in which patterned conductive material layers and insulating material layers are alternately laminated . 2. The planar actuator according to claim 1, wherein the outer surface is orthogonal to a front surface or a back surface of the movable part. The torsion bar is formed to have a height dimension smaller than the height of the movable part, and a stepped part having the same height dimension as the torsion bar is formed outside the movable part,
3. The planar type according to claim 1, wherein the drive coil is formed on an outer surface of the movable portion and an upper surface of the torsion bar parallel to the surface of the movable portion. Actuator. The drive coil has an outer side surface of the movable portion, and the side surfaces parallel to the outer surface of the movable portion of said torsion bar, it is formed on an inner surface facing the outer surface of the movable portion of the fixed portion The planar actuator according to claim 1 , wherein the planar actuator is provided. In a planar actuator manufacturing method for manufacturing an actuator composed of a plate-shaped movable part that is rotatably supported via a torsion bar and driven by a drive coil inside a frame-shaped fixed part.
Etching from the surface side of the first wafer made of silicon to remove the parts other than the fixed part, the torsion bar and the movable part, and slightly remove the part corresponding to the torsion bar from the movable part Removing to reduce the height dimension;
Forming an outer side surface of the movable portion, the coil wire constituting the drive coil in an upper surface parallel to the surface of the movable portion of the torsion bar,
A planar actuator manufacturing method comprising: In a planar actuator manufacturing method for manufacturing an actuator composed of a plate-shaped movable part that is rotatably supported via a torsion bar and driven by a drive coil inside a frame-shaped fixed part.
Etching from the surface side of the first wafer made of silicon, removing the parts other than the fixed part, the torsion bar and the movable part;
Coils constituting an outer side surface of the movable portion, and the side surfaces parallel to the outer surface of the movable portion of the torsion bar, the drive coil and an inner surface facing the outer surface of the movable portion of the fixed portion Forming a wiring; and
A planar actuator manufacturing method comprising:

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