JP2010219727A - Actuator, driving device and imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: an actuator which prevents destruction and degradation of characteristics, and achieves desired displacement; a driving device using the actuator; and an imaging device. <P>SOLUTION: The actuator that moves a target object has a movable part in which specified parts are movable, and a standard part in which the movable part is fixed. In the actuator, the movable part is structured so that a plurality of layers including a first layer, a second layer that performs expansion or shrinking corresponding to heating, which is different from the first layer, and a third heat-generating layer are laminated, and the amount of heat generation of the third layer per specified area of the movable part increases in high heat-releasing areas. In the movable part, the movable part bends corresponding to heat generation of the third layer, and then a specified part becomes movable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an actuator, a driving device using the actuator, and an imaging device.

  In recent years, mobile phones equipped with a camera unit having a zoom function and an autofocus (AF) function are commercially available. In this camera unit, a small actuator for driving the optical lens is required.

  As such an actuator, a semiconductor microactuator capable of driving a movable element with low power consumption has been proposed (for example, Patent Document 1). Specifically, a bimetal element film is provided on one surface side of a plurality of beams of a flexible movable element, and the surface of the bimetal element film is covered with a thermal insulating film, so that one surface side of the beam When the movable element is driven by energization heating with respect to the diffusion resistance layer formed in the above, low power consumption due to an increase in thermal efficiency is realized.

JP 2001-138295 A

  However, in Patent Document 1, attention is paid to the increase in thermal efficiency, but the heat distribution in the actuator is not considered at all. For example, in an actuator, even if heat is evenly applied, the heat distribution becomes non-uniform due to the influence of the connecting and contacting members. Then, due to the non-uniformity of the heat distribution, a phenomenon occurs in which the actuator is displaced in a direction different from the desired direction.

  In such a case, if the actuator is heated too much in order to realize a desired displacement, there is a risk that the original function is lost due to plastic deformation of the bimetal beyond the elastic deformation region. In addition, when shape memory alloy (SMA) is used instead of bimetal, if the actuator is heated too much in order to achieve a desired displacement, stress exceeding a predetermined allowable range is applied to the SMA. If the SMA forgets the memory shape, the original function may be lost. That is, it can be said that the actuator is easily broken or the characteristics are deteriorated. Such a problem is common to actuators that cause displacement by application of heat.

  The present invention has been made in view of the above problems, and provides an actuator capable of realizing a desired displacement while suppressing destruction and deterioration of characteristics, and a drive device and an imaging device using the actuator. For the purpose.

  In order to solve the above-described problem, an actuator according to a first aspect of the present invention is an actuator that moves a moving object, and a movable part in which a predetermined part is displaced, and a reference on which the movable part is fixed. A plurality of layers including a first layer, a second layer that expands or contracts different from the first layer in response to heating, and a third layer that generates heat. The heat radiation amount of the third layer per predetermined region of the movable portion increases as the heat dissipation performance increases, and the movable portion is configured according to the heat generation of the third layer. The predetermined portion is displaced by bending.

  The actuator according to a second aspect of the present invention is the actuator according to the first aspect, wherein the third layer generates heat per predetermined area as the movable part is farther from the reference part. It is characterized in that the quantity is configured to be increased.

  Further, an actuator according to a third aspect of the present invention is the actuator according to the first or second aspect, wherein the third layer includes a heat generating part that generates heat in response to energization, and among the movable parts The electric resistance of the heat generating part per predetermined area of the movable part is reduced as the area is farther from the reference part.

  An actuator according to a fourth aspect of the present invention is the actuator according to the third aspect, wherein the electric resistance of the heat generating part per predetermined region of the movable part is adjusted by the thickness of the heat generating part. It is characterized by.

  Moreover, the actuator which concerns on the 5th aspect of this invention is an actuator which concerns on a 4th aspect, Comprising: The thickness of the said heat generating part is adjusted with the width | variety of the said heat generating part, It is characterized by the above-mentioned.

  Moreover, the actuator which concerns on the 6th aspect of this invention is an actuator which concerns on a 4th aspect, Comprising: The thickness of the said heat generating part is adjusted with the thickness of the said heat generating part, It is characterized by the above-mentioned.

  An actuator according to a seventh aspect of the present invention is the actuator according to the third aspect, wherein the heat generating portion is arranged per predetermined area of the movable portion according to the arrangement density of the heat generating portion per predetermined area of the movable portion. The electrical resistance of the heat generating part is adjusted.

  An actuator according to an eighth aspect of the present invention is the actuator according to any one of the first to seventh aspects, wherein the second layer includes a shape memory alloy.

  An actuator according to a ninth aspect of the present invention is the actuator according to any one of the first to seventh aspects, wherein the first layer includes a first material, and the second The layer includes a second material having a linear expansion coefficient different from that of the first material.

  An actuator according to a tenth aspect of the present invention is the actuator according to any one of the first to ninth aspects, and includes the first layer, the second layer, and the third layer. At least a part thereof is manufactured using photolithography.

  The drive device according to an eleventh aspect of the present invention includes the actuator according to any one of the first to tenth aspects and a moving object that is moved in accordance with the bending of the movable part. Features.

  An imaging device according to a twelfth aspect of the present invention includes the actuator according to any one of the first to tenth aspects, an imaging element, and an optical system that guides light from a subject to the imaging element. The at least one of the image sensor and the optical system is moved according to the bending of the movable part.

  Even with the actuator according to any one of the first to tenth aspects of the present invention, the amount of heat generated is adjusted according to the heat dissipating property, so that the heat distribution in the movable part is made uniform. An actuator capable of realizing a desired displacement while suppressing the above can be provided.

  Further, according to the actuator of the second aspect of the present invention, since the heat generation amount is increased as the movable part is separated from the fixed reference part, the heat in the movable part is increased. The distribution can be made uniform.

  Further, according to the actuator of the third aspect of the present invention, the electrical resistance per predetermined area of the heat generating portion is reduced as the movable portion is separated from the fixed reference portion. Therefore, the heat distribution in the movable part can be made uniform.

  In addition, in the actuator according to any of the fourth to sixth aspects of the present invention, the electric resistance of the heat generating portion per predetermined region of the movable portion is adjusted by the thickness of the heat generating portion, so that the movable portion The uniform heat distribution can be easily achieved.

  Further, according to the actuator of the seventh aspect of the present invention, the heat distribution of the movable portion is adjusted by the configuration in which the electric resistance of the heat generating portion per predetermined area of the movable portion is adjusted by the arrangement density of the heat generating portions. Uniformity can be easily achieved.

  Further, according to the drive device according to the eleventh aspect of the present invention, when the moving object is moved according to the bending of the actuator, the heat distribution of the movable part is made uniform, so that the destruction and the deterioration of the characteristics are achieved. It is possible to provide a drive device using an actuator that can achieve a desired displacement while suppressing the above-described problem.

  Further, according to the imaging device of the twelfth aspect of the present invention, when at least one of the imaging element and the optical system is moved according to the bending of the actuator, the heat distribution of the movable part is made uniform. Therefore, it is possible to provide an imaging device using an actuator that can realize a desired displacement while suppressing destruction and deterioration of characteristics.

It is a schematic diagram which shows schematic structure of the mobile telephone carrying the camera module which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram paying attention to the 1st housing | casing which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram of the camera module which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram of a lens group. It is a cross-sectional schematic diagram of a lens group. It is a lower surface external view of a 1st lens structure layer. It is an upper surface external view of a 2nd lens structure layer. It is a figure for demonstrating the shape of a spacer layer. It is an upper surface external view of a lens position adjustment layer. It is a side external view of a lens position adjustment layer. It is an upper surface external view of an actuator layer. It is a side external view of an actuator layer. It is sectional drawing which shows the structure of a beam part typically. It is a figure which shows the structure of a heater layer typically. It is a lower surface external view of a 1st and 2nd parallel spring. It is a figure which shows the 1st parallel spring with which the lens group was mounted | worn. It is a figure which shows the 2nd parallel spring with which the lens group was mounted | worn. It is a flowchart which shows the manufacturing process of a camera module. It is a top view of a lens constituent layer wafer concerning the 1st and 2nd lens constituent layers. It is a top view of the spacer layer wafer which concerns on a spacer layer. It is a figure which shows the mode of preparation of the 1st lens structure layer. It is a figure which shows the mode of preparation of the 2nd lens structure layer. It is a top view which shows the structural example of the sheet | seat to prepare. It is a figure which shows the preparation process of an assembly jig. It is a figure which shows typically a mode that the prepared sheet | seat etc. are laminated | stacked and joined. It is a figure which shows the mounting process of a 1st frame layer sheet. It is a figure which shows the joining process of a 1st parallel spring sheet | seat. It is a figure which shows the joining process of a 2nd frame layer sheet. It is a figure which shows the attachment process of a lens group. It is a figure which shows the joining process of a 2nd parallel spring sheet | seat. It is a figure which shows the joining process of an actuator layer sheet | seat. It is a figure which shows the joining process of a cover layer sheet. It is a figure which shows the joining process of a lens position adjustment layer sheet. It is a figure which shows typically the structure of the heater layer which concerns on a comparative example. It is a figure which shows the simulation result of the shape of the beam part which concerns on an Example. It is a figure which shows the simulation result of the temperature distribution of the beam part which concerns on an Example. It is a figure which shows the simulation result of the shape of the beam part which concerns on a comparative example. It is a figure which shows the simulation result of the temperature distribution of the beam part which concerns on a comparative example. It is a figure which shows typically the structure of the heater layer which concerns on the 1st modification of this invention. It is sectional drawing which shows typically the structure of the heater layer which concerns on the 1st modification of this invention. It is a figure which shows typically the structure of the heater layer which concerns on the 2nd modification of this invention. It is a figure which shows the aspect which moves the image pick-up element which concerns on the other modification of this invention.

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

<Schematic configuration of mobile phone>
FIG. 1 is a schematic diagram showing a schematic configuration of a mobile phone 100 equipped with a camera module 500 according to an embodiment of the present invention. In FIG. 1 and the drawings after FIG. 1, three axes XYZ orthogonal to each other are appropriately attached in order to clarify the orientation relationship.

  As shown in FIG. 1, the mobile phone 100 is configured as a foldable mobile phone, and includes a first housing 200, a second housing 300, and a hinge part 400.

  Each of the first casing 200 and the second casing 300 is a plate-shaped rectangular parallelepiped, and has a role as a casing for storing various electronic members. Specifically, the first casing 200 includes a camera module 500 and a display (not shown), and the second casing 300 includes a control unit that electrically controls the mobile phone 100, buttons, and the like. And an operating member (not shown).

  The hinge part 400 connects the first casing 200 and the second casing 300 so as to be rotatable. For this reason, the mobile phone 100 can be folded.

  FIG. 2 is a schematic cross-sectional view of the mobile phone 100 focusing on the first housing 200.

  As shown in FIG. 1 and FIG. 2, the camera module 500 is a small imaging device, so-called micro camera unit, having an XY cross section of about 5 mm square and a thickness (depth in the Z direction) of about 3 mm. (MCU).

  Hereinafter, the configuration of the camera module 500, the manufacturing process thereof, and the like will be sequentially described.

<Configuration of camera module>
FIG. 3 is a schematic cross-sectional view of the camera module 500, and the direction indicated by the arrow AR1 corresponds to the + Z direction. In the drawings subsequent to FIG. 3, an arrow AR <b> 1 indicating a direction corresponding to the + Z direction is attached to clarify the orientation relation.

  As shown in FIG. 3, the camera module 500 includes an optical unit KB in which a lens group 20 as a photographing optical system is movably provided, and an imaging unit PB that acquires a photographed image related to a subject image. Yes.

  The imaging unit PB has a configuration in which, for example, an imaging element layer 18 having an imaging element 181 such as a COMS sensor or a CCD sensor, and a cover glass layer 17 are stacked in this order in the + Z direction. The cover glass layer 17 may include a filter layer that cuts infrared rays (IR).

  The optical unit KB includes a lid layer 10, a first frame layer 11, a first parallel spring (upper parallel spring) 12, a second frame layer 13, a second parallel spring (lower parallel spring) 14, an actuator layer 15, and lens position adjustment. The layer 16 and the lens group 20 are provided. The lid layer 10, the first frame layer 11, the first parallel spring 12, the second frame layer 13, the second parallel spring 14, the actuator layer 15, the lens position adjustment layer 16, and the lens group 20 are all in a wafer state (wafer Produced by level). These manufacturing processes will be described later.

  In the optical unit KB, the lens position adjusting layer 16, the actuator layer 15, the second parallel spring 14, the second frame layer 13, the first parallel spring 12, the first frame layer 11, and the lid layer 10 are arranged in this order in the + Z direction. The lens group 20 is held between the second parallel spring 14 and the first parallel spring 12 which are stacked. And the 1st parallel spring 12, the 2nd parallel spring 14, and the actuator layer 15 cooperate, and the lens group 20 which is a moving object is moved to the direction along a Z-axis.

  In the camera module 500, the lid layer 10, the first and second frame layers 11 and 13, the lens position adjustment layer 16, the cover glass layer 17, and the imaging element layer 18 serve as a fixing portion for the lens group 20. The lens group 20 is supported by first and second parallel springs 12 and 14 coupled to the fixed portion.

  More specifically, the second parallel spring 14 is interposed between the actuator layer 15 on the −Z side of the lens group 20 and the lens group 20. A first parallel spring 12 is interposed between the first frame layer 11 on the + Z side of the lens group 20 and the lens group 20. That is, the lens group 20 is sandwiched between the first parallel spring 12 and the second parallel spring 14.

  Here, since the lens group 20 is clamped by the first and second parallel springs 12 and 14, the posture of the lens group 20 is maintained regardless of the movement of the lens group 20, and the optical axis of the lens group 20 is substantially constant. Retained.

  Further, the first and second parallel springs 12 and 14 apply a force in a direction opposite to the moving direction of the lens group 20 (that is, the + Z direction) when the lens group 20 as the moving object moves in the + Z direction. The lens group 20 is given. When the lens group 20 moves in the −Z direction, the direction of the force applied to the lens group 20 by the first and second parallel springs 12 and 14 is the moving direction of the lens group 20 (that is, −Z). Direction).

  Further, in a non-driving state in which the lens group 20 is not moving in the + Z direction (for example, a stationary state before driving), the lens group 20 is moved by the elastic force of the first and second parallel springs 12 and 14 from the lens position adjusting layer 16. The lens group 20 is supported by the lens position adjusting layer 16 by being pressed against the upper end surface of the protrusion 162. In this non-driven state, the lens group 20 is disposed at a predetermined position on the most −Z side of the range (displaceable range) that can be displaced along the Z axis and is stationary.

  Thus, in the non-driven state, the lens group 20 is pressed against the lens position adjusting layer 16 by the elastic force of the first and second parallel springs 12 and 14, so that a strong impact is applied to the camera module 500. Even in such a case, the posture of the lens group 20 is maintained.

  Further, the predetermined position is set to a position where the focal point of the optical unit KB is arranged on the + Z side surface (hereinafter also referred to as “imaging surface”) on which a large number of pixel circuits are arranged in the image sensor 181, for example. Is done. Here, the focal point of the optical unit KB refers to a point where light beams emitted from the optical unit KB gather at one point when parallel light beams enter the optical unit KB from the + Z side. In the present embodiment, the lens group 20 corresponds to the “optical system” of the present invention.

  The actuator layer 15 has a predetermined displacement generator that generates a drive displacement in the + Z direction, and is disposed on the −Z side of the lens group 20. The displacement generator comes into contact with the first protrusion 201 that protrudes toward the −Z side of the lens group 20, and the drive displacement generated by the displacement generator is transmitted to the lens group 20 via the first protrusion 201. That is, the actuator layer 15 moves the lens group 20 that is a moving object in a predetermined direction (here, the + Z direction). In a scene where the drive displacement in the + Z direction in the displacement generating portion is reduced, the lens group 20 is in a direction opposite to the predetermined direction (−Z direction) by the elastic force of the first and second parallel springs 12 and 14. Move to.

  As described above, in the camera module 500, the lens group 20 that is a moving object is coupled to the first and second parallel springs 12 and 14 disposed at positions facing each other via the lens group 20, The first and second parallel springs 12 and 14 are elastically deformed in a direction perpendicular to the lens group 20 (+ Z direction), and hold the posture of the lens group 20. The lens group 20 receives a driving force from the displacement generating portion of the actuator layer 15 and displaces the position along the Z axis.

  As described above, the optical unit KB provided in the camera module 500 can displace the lens group 20 in the optical axis direction (+ Z direction) of the lens group 20, and drive the camera module 500 to displace the lens group 20. To function as a device.

  In addition, the actuator layer 15 according to the present embodiment has a configuration in which the displacement generation unit is displaced according to heat, and the configuration in which the heat distribution is adjusted is adopted, so that the displacement generation unit stabilizes the desired displacement. It is comprised so that it may occur. The detailed configuration and operation of the actuator layer 15 will be described later.

<About the lens group>
The lens group 20 is manufactured at a wafer level using a glass substrate as a base material, and is formed by, for example, superposing two or more lenses. In the present embodiment, a case where the lens group 20 is configured by overlapping two optical lenses is illustrated. In the present embodiment, the lens group 20 functions as an imaging lens that guides light from the subject to the imaging element 181.

  4 and 5 are schematic cross-sectional views of the lens group 20, and the direction indicated by the arrow AR2 corresponds to the + Z direction. FIG. 6 is a bottom view of the lens group 20, and FIG. 7 is a top view of the lens group 20.

  As shown in FIGS. 4 and 5, the lens group 20 includes a first lens constituent layer LY1 having a first lens G1, a second lens constituent layer LY2 having a second lens G2, and a spacer layer RB. . The first lens constituent layer LY1 and the second lens constituent layer LY2 are coupled via the spacer layer RB. Here, the outer edges of the non-lens portions of the first and second lens constituent layers LY1, LY2 have a substantially square shape.

  As shown in FIGS. 4 to 6, the first main surface (here, −Z side) of the first lens constituent layer LY1 having the first lens G1 has a first non-lens portion that does not function as a lens. A protrusion 201 is provided. Further, as shown in FIGS. 4, 5, and 7, the one main surface (here, + Z side) of the second lens constituent layer LY2 having the second lens G2 is provided with a non-lens portion that does not function as a lens. A second protrusion 202 is provided.

  FIG. 8 is a view of the spacer layer RB as viewed from the −Z side, focusing on the shape of the spacer layer RB. As shown in FIG. 8, the spacer layer RB is provided along the outer edge of the non-lens portion of the first and second lens constituting layers LY1, LY2, and the outer edge and the inner edge of the XY cross section are rectangular in shape. It has a configuration.

  The optical axis of the lens group 20 is set in a direction along the Z axis.

<About each functional layer>
Below, the detail of each functional layer which comprises the camera module 500 is demonstrated. For each functional layer, the −Z side surface is referred to as one main surface, and the + Z side surface is referred to as the other main surface.

○ Image sensor layer 18:
As shown in FIG. 3, the image sensor layer 18 receives light from the subject that has passed through the optical unit KB, and generates an image signal related to the image of the subject, its peripheral circuit, and the image sensor 181. It is a member provided with the outer peripheral part which surrounds. The image sensor 181 is configured by arranging a large number of pixel circuits.

  Note that a solder ball HB for performing reflow soldering is provided on one main surface (the surface on the −Z side) of the imaging element layer 18. Although not shown here, various types of wiring for applying a signal to the image sensor 181 and reading a signal from the image sensor 181 are connected to one main surface of the image sensor layer 18. Terminals are provided.

○ Cover glass layer 17:
As shown in FIG. 3, the cover glass layer 17 has a substantially flat plate shape and an XY cross section having a substantially square shape, and is made of transparent glass or the like. The cover glass layer 17 is bonded to the other main surface (+ Z side surface) of the image sensor layer 18 and has a function of protecting the image sensor 181.

  The image sensor substrate 178 is configured with the cover glass layer 17 bonded to the image sensor layer 18.

○ Lens position adjustment layer 16:
The lens position adjustment layer 16 is configured by using a resin material, is disposed between the image sensor 181 and the lens group 20, and is a member that adjusts the distance between the image sensor 181 and the lens group 20. Specifically, the lens position adjustment layer 16 defines the position (initial position) of the lens group 20 in the non-driven state. The lens position adjustment layer 16 is generated using, for example, a method of etching a resin.

  FIG. 9 is a top view of the lens position adjusting layer 16. FIG. 10 is a side view of the lens position adjustment layer 16.

  As shown in FIG. 9, the lens position adjustment layer 16 includes a frame body 161 and a protrusion 162.

  The frame 161 is a substantially rectangular annular portion that constitutes the outer peripheral portion of the lens position adjusting layer 16, and has a plate-like shape substantially parallel to the XY plane. The frame 161 forms a hole (through-hole) 16H penetrating in the direction along the Z axis, and the + Y side plate-like member and the −Y side plate-like member constituting the frame 161 are: Each has a protruding portion 161T that protrudes toward the through hole 16H.

  Further, one main surface of the frame body 161 is bonded to the adjacent cover glass layer 17, and the other main surface of the frame body 161 is adjacent to the adjacent actuator layer 15 (specifically, the frame body 152 ( To be described later)).

  The projecting portion 162 is configured to stand in the + Z direction in the vicinity of the inner edge of the convex portion 161T constituting the frame body 161. The projection 162 is a plate-like portion having a substantially rectangular board surface substantially parallel to the XZ plane, and the longitudinal direction of the projection 162 is a direction substantially parallel to the X axis, and the short direction of the projection 162 Is a direction substantially parallel to the Z-axis. The end surface on the + Z side of the protrusion 162 has a function of placing the lens group 20 at the initial position when the lens group 20 abuts.

  In FIG. 9, a region where a plurality of pixel circuits constituting the image sensor 181 are arranged (hereinafter also referred to as “pixel array region”), that is, an outer edge of the front surface (image pickup surface) of the image sensor 181 is indicated by a broken line. Yes. As shown in FIG. 9, the imaging surface is configured so that the relationship of (short side length) :( long side length) :( diagonal length) = 3: 4: 5 is established. Yes. The protrusion 162 is disposed at a position that sandwiches the optical path from the subject through the lens group 20 to the pixel array region of the image sensor 181 in the direction in which the width of the pixel array region is the narrowest. That is, the protrusion 162 is installed so as not to adversely affect the photographing and increase the size of the apparatus.

○ Actuator layer 15:
The actuator layer 15 is a thin plate-like member in which a displacement element (hereinafter also referred to as “actuator element”) for generating a driving force is provided on a metal or silicon (Si) substrate. FIG. 11 is a schematic view of the actuator layer 15 as viewed from above. FIG. 12 is a schematic view of the actuator layer 15 as viewed from the side.

  As shown in FIG. 11, the actuator layer 15 includes a frame body 152 constituting an outer peripheral portion and two plate-like beams protruding from the frame body 152 with respect to a hollow portion inside the frame body 152. Part 151. That is, one end of the beam portion 151 is fixed to the frame body 152. In the present embodiment, the beam portion 151 corresponds to the “movable portion” of the present invention, and the frame body 152 corresponds to the “reference portion” of the present invention.

  The beam portion 151 is configured by laminating a plurality of layers. FIG. 13 is a diagram for explaining the laminated structure of the beam portion 151, and the direction indicated by the arrow AR3 corresponds to the + Z direction.

  As shown in FIG. 13, the beam portion 151 includes a substrate 1501, an insulating layer 1502, an actuator element layer 1503, an insulating layer 1504, and a heater layer 1505 stacked in this order from the −Z side to the + Z side. It is configured. Here, the actuator element layer 1503 is made of a shape memory alloy (SMA) thin film, the insulating layers 1502 and 1504 are made of silica, and the heater layer 1505 is made of a patterned metal such as platinum. Is done.

  In this embodiment, the substrate 1501 corresponds to the “first layer” of the present invention, the actuator element layer 1503 corresponds to the “second layer” of the present invention, and the heater layer 1505 corresponds to the “first layer” of the present invention. It corresponds to the “third layer”.

  FIG. 14 is a diagram showing a detailed configuration of one main surface of the actuator layer 15.

  As shown in FIG. 14, a terminal portion 1521, a wiring portion 1522, a heater layer 1505, a wiring portion 1523, a heater layer 1505, a wiring portion 1524, and a terminal portion 1525 are provided on one main surface side of the actuator layer 15. Are electrically connected in this order. When a voltage is applied between the two terminal portions 1521 and 1525, a current corresponding to the energization flows through the heater layer 1505, and the heater layer 1505 generates heat by its own Joule heat. In the present embodiment, the heater layer 1505 corresponds to the “heat generating portion” of the present invention.

  Note that the terminal portions 1521 and 1525, the wiring portions 1521 to 1524, and the heater layer 1505 may be made of the same material or different materials. However, from the viewpoint of reducing power consumption, the resistance per unit length of the heater layer 1505 is preferably set to be higher than that of other portions.

  The heater layer 1505 is linearly disposed from one end (fixed end) ST side fixed to the frame body 152 on the other main surface side of the beam portion 151 to the vicinity of the other end (free end) FT. A U-turn is made in the vicinity of the end (free end) FT, and it is linearly arranged from the vicinity of the other end (free end) FT to the one end (fixed end) ST side. In other words, the heater layer 1505 is configured to have a long and thin substantially U-shaped line. The heater layer 1505 is disposed over substantially the entire region of the beam portion 151 along the direction in which the beam portion 151 extends.

  While the heater layer 1505 has a substantially constant thickness in the Z direction, the line width (line width) increases in accordance with the separation distance from the frame body 152. If the line width of the heater layer 1505 is relatively wide, the thickness of the heater layer 1505 is relatively large, and the electrical resistance of the heater layer 1505 is relatively reduced. Here, it is preferable that the cross-sectional area of the heater layer 1505 in the vicinity of the free end FT is set to be about 5 to 10 times the cross-sectional area of the heater layer 1505 in the vicinity of the fixed end ST.

  Here, consider the electric resistance of the heater layer 1505 disposed in each region (predetermined region) in which the other main surface of the beam portion 151 is divided into a plurality of sections having the same area from the fixed end ST to the free end FT. In the beam portion 151, the electric resistance of the heater layer 1505 per predetermined region of the beam portion 151 is adjusted by the thickness of the heater layer 1505. In other words, the electric resistance of the heater layer 1505 per predetermined region of the beam portion 151 is reduced as the region of the beam portion 151 is farther from the frame body 152. Therefore, in the beam portion 151, when a voltage is applied to the heater layer 1505 and energized, the heat generation amount of the heater layer 1505 per predetermined region decreases as the region is away from the frame 152. Become.

  For example, when the beam portion 151 is equally divided into three regions from the fixed end ST to the free end FT, the first region on the fixed end ST side, the second region in the middle, and the third region on the free end FT side It is divided into and. The electric resistance of the heater layer 1505 in the first region is the highest, the electric resistance of the heater layer 1505 in the third region is the lowest, and the electric resistance of the heater layer 1505 in the order of the first region, the second region, and the third region. Is set to be low. That is, when a voltage is applied to the heater layer 1505 and energized, the heat generation amount of the heater layer 1505 in the first region is the largest, and the heat generation amount of the heater layer 1505 in the third region is the smallest. The amount of heat generated by the heater layer 1505 decreases in the order of the second region and the third region.

  In the actuator layer 15 described above, the heat generated by the heater layer 1505 is conducted from the beam portion 151 to the frame body 152 through the fixed end ST. For this reason, as the beam portion 151 is closer to the fixed end ST, natural cooling is more likely to occur, and heat dissipation becomes higher. Therefore, if heat is uniformly applied to the entire area of the beam portion 151, the temperature of the beam portion 151 decreases as it approaches the fixed end ST, and the temperature of the beam portion 151 decreases as it approaches the free end FT. The temperature of 151 becomes high. Therefore, under such conditions, the deformation of the beam portion 151 becomes uneven, and a desired displacement by the beam portion 151 cannot be obtained.

  With respect to such a problem, in the present embodiment, the higher the heat dissipation of the beam portion 151, the more current is supplied to the heater layer 1505. The heating amount of the heater layer 1505 is configured to increase. The temperature distribution, deformation mode, and advantages of the beam portion 151 obtained by adopting such a configuration will be described later.

  Moreover, the actuator layer 15 is manufactured by applying, for example, a photolithography technique frequently used in a semiconductor manufacturing process or the like. Specifically, the actuator layer 15 is manufactured by the following process.

  First, an insulating layer 1502 made of silica, the actuator element layer 1503 made of SMA, and an insulating layer 1504 made of silica are stacked in this order on the substrate 1501 by sputtering or vapor deposition. Next, a desired resist pattern is formed on the insulating layer 1504, and a metal heater layer 1505 is formed by a sputtering method, a vapor deposition method, or the like. Then, a desired resist pattern is formed, and the beam portion 151, the frame body 152, and the hollow portion are formed by etching or the like. Thereafter, the beam 151 is set in a mold having a shape to be memorized, and a heating process (shape memory process) is performed at a predetermined temperature (for example, 600 ° C.).

  The SMA has a characteristic that when it exceeds a predetermined phase transformation temperature by heating and reaches a predetermined temperature, it is restored to a predetermined contracted shape (memory shape) stored in advance. For this reason, when the SMA is heated by energization of the heater layer 1505, the SMA contracts and deforms so as to have a memory shape. The actuator element layer 1503 contracts in response to heating by the function of SMA, while the substrate 1501 expands in response to heating. For this reason, when the heater layer 1505 generates heat, the actuator element layer 1503 contracts relative to the substrate 1501, and as shown in FIG. 12, the beam portion 151 moves so that the free end FT moves in the + Z direction. Turn to. That is, the portion on the free end FT side of the beam portion 151 functions as a displacement generating portion. In the present embodiment, the frame body 152 becomes a reference portion for displacement of the beam portion 151.

  The heater layer 1505 is energized from an electrode provided on the imaging element layer 18, and the conduction from the electrode to the heater layer 1505 via the terminal portions 1521 and 1525 includes, for example, the actuator layer 15 and the lens. What is necessary is just to carry out via the thin conductive member (not shown) affixed on the side surface of the position adjustment layer 16 and the cover glass layer 17.

  The frame body 152 of the actuator layer 15 is joined to the fixed frame body 141 (see FIG. 15) of the second parallel spring 14. In the joined state, the free end FT side of each beam portion 151 comes into contact with the corresponding first protrusion 201. For this reason, the displacement generated at the free end FT of each beam portion 151 is transmitted to the lens group 20 via each first protrusion 201. That is, each beam portion 151 applies a force to the lens group 20 in the + Z direction, thereby displacing the lens group 20 in the + Z direction.

○ Second parallel spring 14:
FIG. 15 is an external view of the lower surface of the second parallel spring 14. FIG. 16 is a view showing the second parallel spring 14 joined to the lens group 20.

  As shown in FIG. 15, the second parallel spring 14 is an elastic member having a fixed frame body 141 and an elastic part 142, and is a layer (elastic layer) that forms a spring mechanism.

  The fixed frame 141 constitutes the outer peripheral portion of the second parallel spring 14 and is joined to the frame 152 of the adjacent actuator layer 15.

  The elastic part 142 has a connection part PG1 with the fixed frame 141 and a joint part PG2 with the lens group 20, and the connection part PG1 and the joint part PG2 are connected by a plate-like member EB. Then, as shown in FIG. 16, the second parallel spring 14 is joined to the lens group 20 at a joint portion PG <b> 2 provided in the elastic portion 142.

  The first projecting portion 201 contacts the vicinity of the free end FT of the actuator layer 15 through the gap between the fixed frame body 141 of the second parallel spring 14 and the plate-like member EB. That is, the second parallel spring 14 has a shape that does not contact the first protrusion 201 of the lens group 20.

  For this reason, as the lens group 20 is moved in the + Z direction with respect to the fixed frame body 141, the positions of the connecting portion PG1 and the joint portion PG2 are shifted in the Z direction, and the plate-like member EB undergoes bending deformation (flexure deformation). Resulting in curvature. That is, the second parallel spring 14 can be elastically deformed in the optical axis direction (± Z direction) of the lens group 20 by elastic deformation of the plate-like member EB, and functions as a spring mechanism.

  The second parallel spring 14 is manufactured using a SUS metal material or phosphor bronze. For example, when the second parallel spring 14 is made of a SUS-based metal material, a resist in the shape of a parallel spring is patterned on the metal material by photolithography, and wet etching is performed by immersing in an iron chloride-based etchant. As a result, a pattern of parallel springs is formed.

○ Second frame layer 13:
As shown in FIG. 3, the second frame layer 13 is a ring-shaped member in which the outer edge and the inner edge of the XY cross section are each substantially rectangular, and forms a hollow portion that penetrates along the Z-axis. The second frame layer 13 surrounds the lens group 20 from the side by arranging the lens group 20 in the hollow portion. In addition, resin, glass, etc. are mentioned as a raw material which comprises the 2nd frame layer 13, The 2nd frame layer 13 is manufactured by what is called a press method using a metal metal mold | die, the injection molding method, etc.

  The lower end surface (one main surface) located on the −Z side of the second frame layer 13 is joined to the fixed frame body 141 of the adjacent second parallel spring 14. Further, the upper end surface (other main surface) located on the + Z side of the second frame layer is joined to the adjacent first parallel spring 12 (specifically, a fixed frame body 121 (described later) of the first parallel spring 12). The

○ First parallel spring 12:
As shown in FIG. 15, the first parallel spring 12 is an elastic member having the same configuration and function as the second parallel spring 14, and includes a fixed frame body 121 and an elastic portion 122.

  One main surface of the fixed frame 121 is joined to the other main surface of the adjacent second frame layer 13, and the other main surface of the fixed frame 121 is connected to the adjacent first frame layer 11 (in detail, the first frame It is joined to the lower end surface (described later) on the −Z side of the layer 11.

  FIG. 17 is a view showing the first parallel spring 12 joined to the lens group 20. As shown in FIG. 17, the joint part PG <b> 2 provided in the elastic part 122 is joined to the upper end surface on the + Z side of the projection part 202 of the lens group 20.

  For this reason, when the lens group 20 is moved relative to the fixed frame 121 in the + Z direction, elastic deformation occurs in the plate member EB, and the first parallel spring 12 functions as a spring mechanism.

○ First frame layer 11:
As shown in FIG. 3, the first frame layer 11 is a ring-shaped member in which the outer edge and the inner edge of the XY cross section are each substantially rectangular like the second frame layer 13 and penetrates along the Z axis. Forming a hollow portion. The hollow portion of the first frame layer 11 serves as a space in which the plate-like member EB and the protrusion 202 that are elastically deformed when the lens group 20 is moved in the + Z direction can move. The first frame layer 11 is formed by the same material and manufacturing method as the second frame layer 13.

  The lower end surface (one main surface) located on the −Z side of the first frame layer 11 is joined to the fixed frame body 121 of the adjacent first parallel spring 12. Moreover, the upper end surface (other end surface) located on the + Z side of the first frame layer 11 is joined to the adjacent lid layer 10 (specifically, near the outer peripheral portion of the lid layer).

○ Cover layer 10:
As shown in FIG. 3, the outer edge of the XY cross section has a substantially square shape, and the lid layer 10 has a hole (through hole) 10 </ b> H penetrating in a direction parallel to the Z axis at a substantially center, and is substantially in the XY plane. It is a plate-like member having a parallel board surface. The through hole 10H is a hole for guiding light from the subject to the image sensor 181 through the lens group 20, and the lid layer 10 is formed by pressing a flat resin material or patterning the resin material. The through hole 10H is formed and manufactured by a method of etching later.

  In addition, although illustration is abbreviate | omitted in FIG. 3, on the upper surface (other main surface) side of the lid | cover layer 10 so that dust etc. may not penetrate | invade into the camera module 500 from the through-hole 10H of the lid | cover layer 10, A transparent protective layer composed of glass or the like is provided as appropriate.

<Camera module manufacturing process>
Here, the manufacturing process of the camera module 500 will be described in detail.

  FIG. 18 is a flowchart showing the manufacturing process of the camera module 500. As shown in FIG. 18, (Process A) generation of the lens group 20 (Step SP1), (Process B) preparation of the sheet (Step SP2), (Process C) preparation of the assembly jig (Step SP3), (Process D) First bonding of the sheet (step SP4), (Process E) Mounting of the lens group 20 (Step SP5), (Process F) Second bonding of the sheet (Step SP6), (Process G) Image sensor substrate 178 (Step SP7) and (process H) dicing (step SP8) are sequentially performed, and the camera module 500 is manufactured. Hereinafter, each step will be described.

○ Generation of lens group 20 (step A):
In step SP1, the lens group 20 is generated.

  First, a wafer in which a large number of lens groups 20 are arranged in a matrix (hereinafter also referred to as a “lens group wafer”) is manufactured, and a large number of lens groups 20 are separated into pieces by dicing. Produced.

  The lens group wafer includes a wafer in which a large number of first lens constituent layers LY1 are arranged (first lens constituent layer wafer), a wafer in which a large number of spacer layers RB are arranged (spacer layer wafer), and a large number of second lenses. A wafer (second lens constituent layer wafer) on which the constituent layers LY2 are arranged is stacked and bonded to each other.

  FIG. 19 is a plan view schematically showing the first and second lens component layer wafers U20a and U20c. FIG. 20 is a plan view schematically showing the spacer layer wafer U20b.

  As shown in FIG. 19, the first lens component layer wafer U20a is integrally formed by arranging a large number of first lens component layers LY1 in a matrix at first predetermined intervals. In addition, the second lens component layer wafer U20c is configured integrally by arranging a large number of second lens component layers LY2 in a matrix at first predetermined intervals.

  In addition, as shown in FIG. 20, the spacer layer wafer U20b is configured integrally with a large number of spacer layers RB arranged in a matrix at first predetermined intervals. In other words, the spacer layer wafer U20b has a lattice structure in which a large number of through-holes having a substantially square outer edge are arranged in a matrix at first predetermined intervals.

  The first lens component layer wafer U20a, the spacer layer wafer U20b, and the second lens component layer wafer U20c are stacked in this order and bonded to each other, and then the broken lines shown in FIGS. Each lens group 20 is separated into individual pieces by dicing along the line.

  Here, a manufacturing method of the first and second lens component layer wafers U20a and U20c will be described. The manufacturing method of each first lens constituent layer LY1 in the first lens constituent layer wafer U20a is the same, and the manufacturing method of each second lens constituent layer LY2 in the second lens constituent layer wafer U20c is also the same. For this reason, here, description will be given focusing on the production of the first and second lens constituent layers LY1, LY2.

  The first and second lens constituent layers LY1, LY2 are both produced by the same method using a glass substrate as a base material. FIG. 21 is a diagram showing a state of manufacturing the first lens constituent layer LY1 having the first lens G1, and FIG. 22 is a diagram showing a state of manufacturing the second lens constituent layer LY2 having the second lens G2. is there.

  As shown in FIG. 21, a wafer-like substrate 20BS is prepared. Examples of the material of the substrate 20BS include glass such as so-called Tempax (registered trademark), resin such as so-called PPMA, and the like.

  Next, a highly transparent acrylic or epoxy ultraviolet (UV) curable resin is applied to both surfaces of the substrate 20BS. Then, a transparent lens molding die 20CA having one curved surface shape of the first lens G1 is pressed from the upper surface of the substrate 20BS with a predetermined pressure, and the other curved surface of the first lens G1 is pressed from the lower surface of the substrate 20BS. A transparent lens molding die 20CB having the shape and the shape of the first protrusion 201 is pressed with a predetermined pressure. At this time, the ultraviolet rays UV1 are irradiated to form the polymer lenses GP1 and GP2 and the first protrusions 201 on the respective surfaces of the substrate 16BS. By such a method, the first lens constituent layer wafer U20a is manufactured. The tip of the first protrusion 201 is a surface that contacts the actuator layer 15.

  Further, as shown in FIG. 22, a highly transparent acrylic or epoxy ultraviolet (UV) curable resin is applied to both surfaces of the substrate 20BS. Then, a transparent lens molding die 20CC having the shape of one curved surface of the second lens G2 and the shape of the second protrusion 202 is pressed from the upper surface of the substrate 20BS with a predetermined pressure, and the second lens G2 is pressed from the lower surface of the substrate 20BS. A transparent lens molding die 20CD having the shape of the other curved surface of the two lenses G2 is pressed with a predetermined pressure. At this time, ultraviolet rays UV1 are irradiated to form polymer lenses GP3 and GP4 and second protrusions 202 on each surface of the substrate 16BS. By such a method, the second lens constituent layer wafer U20c is manufactured. The tip of the second protrusion 202 is a surface joined to the first parallel spring 12.

  Further, the spacer layer wafer U20b is manufactured, for example, by processing a wafer-like glass substrate by etching or the like.

  The first and second lens component layer wafers U20a and U20c and the spacer layer wafer U20b manufactured in this way are formed with alignment marks for alignment at two or more predetermined locations.

  Then, it is assembled into an integrated lens group 20 so that the spacer layer RB is sandwiched between the first and second lens constituent layers LY1, LY2.

  Specifically, the first lens component layer wafer U20a, the spacer layer wafer U20b, and the second lens component layer wafer U20c are aligned and bonded while confirming the respective alignment marks using a mask aligner or the like. The At this time, the first and second lens constituent layers LY1, LY2 and the spacer layer RB constitute the lens group 20.

  As a method of bonding the three wafers U20a to U20c, for example, UV curing layers are provided on the upper and lower surfaces of the spacer layer RB to be bonded to the first and second lens constituent layers LY1 and LY2, and bonded by irradiating ultraviolet rays. Or a method of irradiating the upper and lower surfaces of the spacer layer RB with plasma of an inert gas and bonding the surfaces of the spacer layer RB while being activated (surface activated bonding method).

  Further, when forming a diaphragm in the camera module 500, for example, a technique of forming a diaphragm layer with a resin material or the like colored separately in black is used.

  In this manner, a wafer (lens group wafer) in which a large number of lens groups 20 are arranged in a matrix is manufactured, and a large number of individual lens groups 20 are manufactured by dicing.

○ Sheet preparation (process B):
In step SP2, a sheet relating to each functional layer constituting the camera module 500 is formed for each layer. FIG. 23 is a plan view illustrating a configuration example of a sheet to be prepared. Here, it is assumed that a wafer-level disk-shaped sheet is prepared.

  In the sheet for each functional layer, a large number of chips corresponding to members related to the functional layer are formed in a matrix in a predetermined arrangement.

  For example, as shown in FIG. 23, a large number of chips corresponding to the first frame layer 11 are formed in a predetermined arrangement on the sheet (first frame layer sheet) U11 of the first frame layer 11. Here, the expression “predetermined arrangement” is used to include a state in which a large number of chips are arranged at predetermined intervals in a predetermined direction.

  The first frame layer sheet U11 has a lattice shape in which side surfaces of chips corresponding to the first frame layer 11 are connected to each other. The first frame layer sheet U11 is made of a resin material, glass, or the like.

  For example, when the first frame layer sheet U11 is made of a resin material, the first frame layer sheet U11 is manufactured by a method such as press molding or injection molding using a metal mold. When the first frame layer sheet U11 is made of glass or the like, the first frame layer sheet U11 is manufactured, for example, by so-called blasting using a metal or ceramic shadow mask.

  In addition, in the lens position adjustment layer 16 sheet (lens position adjustment layer sheet) U16, a large number of chips corresponding to the lens position adjustment layer 16 are formed in a predetermined arrangement. The lens position adjustment layer sheet U16 has a shape in which side surfaces of chips corresponding to the lens position adjustment layer 16 are connected to each other. The lens position adjustment layer sheet U16 is made of a resin material or the like.

  For example, the lens position adjusting layer sheet U16 is manufactured by manufacturing a mold having the shape of the lens position adjusting layer sheet U16, pouring resin into the mold, heating the resin together with the mold, and then cooling. The The lens position adjustment layer sheet U16 may be manufactured using injection molding or the like.

  Thus, in step SP2, as with the first frame layer sheet U11 and the lens position adjustment layer 16, the lid layer 10, the first parallel spring 12, the second frame layer 13, the second parallel spring 14, and the actuator layer 15 are used. Each of the sheets U10, U12 to U15 on which a large number of chips related to each functional layer are formed in a predetermined arrangement, and a chip related to the image sensor substrate 178 formed by joining the cover glass layer 17 and the image sensor layer 18 Including sheets (imaging element substrate sheets) U178 are prepared. That is, eight sheets U10 to 16 and U178 are prepared.

○ Preparation of assembly jig (process C):
In step SP3, the assembly jig 300 is prepared.

  FIG. 24 is a diagram focusing on the part of the assembly jig 300 that is used to manufacture each camera module 500. The assembly jig 300 is configured by providing a large number of protrusions 301 having substantially the same shape on a flat base, in a predetermined arrangement.

  In the assembly jig 300, alignment marks for alignment are formed at two or more predetermined locations. Further, the upper surface of the protrusion 301 is configured to be substantially parallel to the main surface of the flat base.

○ First joining of sheets (process D):
In step SP4, three sheets U11 to U13 among the eight prepared sheets U10 to 16 and U178 are joined.

  FIG. 25 shows a state in which three sheets U11 to U13 are laminated and joined in step S4, a state in which the lens group 20 is attached in step S5, and four sheets U10 and U14 to U16 are laminated in step S6. It is a figure which shows typically a mode that it joins, and a mode that the image pick-up element board | substrate sheet | seat U178 is joined in step SP7.

  In step SP4, as shown in FIG. 25, for the first frame layer sheet U11, the first parallel spring sheet U12, and the second frame layer sheet U13, the chips included in the sheets U11 to U13 are stacked on each other. Thus, alignment (alignment) is performed with the sheet shape. And each sheet | seat U11-U13 is joined using an adhesive agent etc.

  FIG. 26 to FIG. 28 are diagrams showing how the sheets U11 to U13 are stacked and joined, focusing on each chip constituting one camera module 500. FIG. 26 to 28, the camera module 500 shown in FIG. 3 is shown upside down for convenience of the process.

  As shown in FIG. 26, the first frame layer sheet U11 is placed on the assembly jig 300 so that each first frame layer 11 is placed at a predetermined position on the base of the assembly jig 300. Placed. In FIG. 26, the moving direction of the first frame layer sheet U11 when the first frame layer sheet U11 is carried on the assembly jig 300 is indicated by an arrow YJ1.

  Next, as shown in FIG. 27, the first frame layer sheet is formed by joining the fixed frame 121 constituting the outer peripheral portion of the first parallel spring 12 on one main surface of the first frame layer 11. The first parallel spring seat U12 is joined to U11.

  Specifically, the fixed frame 121 is pressed against the one main surface of the first frame layer 11 in the direction indicated by the arrow YJ2, and the other main surface of the fixed frame 121 and the first frame layer 11 The main surface is joined. At this time, the joint portion PG2 of the first parallel spring 12 is brought into contact with the upper surface of the protrusion 301 of the assembly jig 300, whereby the substantially parallel plate shape of the first parallel spring 12 is maintained.

  Further, as shown in FIG. 28, the other main surface of the second frame layer 13 is joined to one main surface of the fixed frame 121 constituting the outer peripheral portion of the first parallel spring 12, so that the first The second frame layer sheet U13 is joined to the parallel spring sheet U12.

  Specifically, the second frame layer 13 is pressed against the main surface of the fixed frame 121 of the first parallel spring 12 in the direction indicated by the arrow YJ3, and the main surface of the fixed frame 121 The other main surface of the two-frame layer 13 is joined.

○ Attaching the lens group (Process E):
FIG. 29 shows how the lens group 20 is attached.

  In step SP5, as shown in FIG. 29, the lens group 20 generated in step SP1 is attached to a hollow portion of each second frame layer 13 of the unit manufactured in step SP4 by a predetermined mounter. That is, the lens group 20 is inserted into each gap of the second frame layer sheet U13 having a lattice shape.

  Specifically, the end surfaces of the two second protrusions 202 of the lens group 20 are respectively joined to the joint PG <b> 2 of the first parallel spring 12. At this time, while the lens group 20 is pressed against the joint portion PG2 in the direction indicated by the arrow YJ4, the end surface of the second protrusion 202 is joined to the one main surface side of the joint portion PG2.

  As a joining method, an adhesive (ultraviolet curable adhesive) that is cured by irradiation of ultraviolet rays is applied in advance to the end surface of the second protrusion 202 of the lens group 20, and the second protrusion 202 of the lens group 20 is applied. The method of joining by irradiation of an ultraviolet-ray etc. in the state which contact | abutted with respect to the junction part PG2 of the 1st parallel spring 12 is mentioned.

○ Sheet second joining (process F):
In step SP6, as shown in FIG. 25, four sheets U10 and U14 to U16 of the eight sheets U10 to 16 and U178 prepared in step SP2 are joined.

  Specifically, in step SP6, each chip included in the second parallel spring sheet U14 and the actuator layer sheet U15 is attached to the second frame layer sheet with respect to one main surface side of the units generated up to step SP5. Positioning (alignment) is performed while maintaining the sheet shape so as to be stacked on each chip included in U13. And each sheet | seat U14, U15 is joined using an adhesive agent etc. in order.

  Further, the sheet is so formed that each chip included in the lid layer sheet U10 is stacked with respect to each chip included in the first frame layer sheet U11 with respect to the other main surface side of the first frame layer sheet U11. Alignment (alignment) is performed in the shape. In this state, the lid layer sheet U10 is bonded to the other main surface side of the first frame layer sheet U11 using an adhesive or the like.

  Further, the sheet-like shape is formed so that each chip included in the lens position adjustment layer sheet U16 is stacked on each chip included in the actuator layer sheet U15 with respect to one main surface side of the actuator layer sheet U15. The alignment (alignment) is performed as it is. In this state, the lens position adjustment layer sheet U16 is bonded to the other main surface side of the actuator layer sheet U15 using an adhesive or the like.

  FIG. 30 to FIG. 33 are diagrams showing how the sheets U10 and U14 to U16 are stacked and joined, focusing on each chip constituting one camera module 500. FIG. 30 and 31, as in FIGS. 26 to 28, the camera module 500 shown in FIG. 3 is shown upside down for convenience of the process. On the other hand, in FIGS. 32 and 33, the upper and lower sides of the camera module 500 shown in FIG. 3 are shown in the same state.

  As shown in FIG. 30, the second parallel is formed on the one main surface of the second frame layer sheet U13 so that the second parallel spring 14 is bonded to the one main surface side of the second frame layer 13 and the lens group 20. The spring seat U14 is joined.

  Specifically, while the fixed frame 141 of the second parallel spring 14 is pressed against the one main surface of the second frame layer 13 in the direction indicated by the arrow YJ5, the other main surface of the fixed frame 141 is It is joined to one main surface of the second frame layer 13 by an adhesive or the like. At this time, the joint part PG2 of the second parallel spring 14 is joined to the non-lens part of the first lens constituent layer LY1 of the lens group 20 by an adhesive or the like.

  Next, as shown in FIG. 31, the actuator layer sheet U <b> 15 is bonded onto one main surface of the second parallel spring sheet U <b> 14 so that the actuator layer 15 is bonded to one main surface of the second parallel spring 14. The

  Specifically, while the frame body 152 of the actuator layer 15 is pressed in the direction indicated by the arrow YJ6 against one main surface of the fixed frame body 141 of the second parallel spring 14, the other main surface of the frame body 152 is pressed. And one main surface of the fixed frame 141 are joined together by an adhesive or the like.

  Furthermore, at this time, the free end FT side of each beam portion 151 of the actuator layer 15 abuts on the corresponding first protrusion 201 and the free end FT of each beam portion 151 is pushed up in the direction corresponding to the −Z side. It becomes the state.

  Next, as shown in FIG. 32, the unit formed by joining the actuator layer sheet U15 on the second parallel spring sheet U14 is removed from the assembly jig 300, and the lid layer sheet is attached to the unit. U10 is joined. When the unit is removed from the assembly jig 300, the lens group 20 is held by the first and second parallel springs 12, 14, so that the lens group 20 floats in the air. It becomes.

At this time, the unit joined up to the actuator layer sheet U15 is turned upside down, and the outer peripheral portion of the lid layer 10 is pressed against the other main surface of the first frame layer 11 in the direction indicated by the arrow YJ7. Meanwhile, the other main surface of the first frame layer 11 and one main surface of the outer peripheral portion of the lid layer 10 are joined by an adhesive or the like.

  Furthermore, as shown in FIG. 33, the lens with respect to one main surface of the actuator layer sheet U15 is so that the frame body 161 of the lens position adjusting layer 16 is bonded to one main surface of the frame body 152 of the actuator layer 15. The position adjustment layer sheet U16 is joined.

  Specifically, the unit formed by joining up to the lid layer sheet U10 is placed on the other main surface of the lens position adjustment layer sheet U16, and the unit is pushed down in the direction indicated by the arrow YJ8. The other main surface of the lens position adjustment layer sheet U16 and one main surface of the actuator layer sheet U15 are bonded together with an adhesive or the like.

  At this time, the upper end surface of the protrusion 162 of the lens position adjustment layer 16 contacts a part of the non-lens portion of the first lens constituent layer LY1 of the lens group 20, and the lens group 20 is pushed up to the lid layer 10 side. . Further, the force by which the beam portion 151 of the actuator layer 15 is pushed down by the first projection 201 is reduced, and the free end FT of the beam portion 151 of the actuator layer 15 that has been pushed down by the first projection 201 rises in the + Z direction. To do. And the beam part 151 produces little elastic force, ie, the shape of the beam part 151 becomes a substantially flat plate shape.

  However, the extending distance along the Z axis of the first protrusion 201 and the protrusion 162 is set so that the state where the first protrusion 201 and the free end FT are in contact with each other is maintained. With such a setting, when the beam portion 151 is deformed and the free end FT is displaced in the + Z direction, the free end FT does not come into contact with the first protrusion 201 and is swung freely. Is prevented.

  Further, at this time, both the first and second parallel springs 12 and 14 have a large displacement in the + Z direction position of the joint portion PG2 with respect to the connection portion PG1, that is, bending deformation (flexure deformation) of the plate member EB. That is, each plate member EB is elastically deformed and stress (elastic force) is charged so that each joint portion PG2 is displaced toward the lid layer 10 side.

  Therefore, the lens group 20 is pressed against the upper end surface of the protrusion 162 of the lens position adjusting layer 16 by the elastic force generated in each plate member EB. The pressing force of the lens group 20 against the protrusion 162 suppresses the occurrence of deviations in the posture and position of the lens group 20 such as the tilt amount regardless of the holding posture of the camera module 500 by the user.

○ Mounting of image sensor substrate (process G):
In step SP7, the lens position adjusting layer sheet is bonded so that the outer peripheral portion of the image sensor substrate 178 is bonded to the frame 161 of the lens position adjusting layer 16 of the unit formed by bonding the lens position adjusting layer 16. The other main surface of the imaging element substrate sheet U178 is bonded to one main surface of U16.

○ Dicing (Process H):
In step SP8, a large number of lens groups 20 are inserted, and a laminated member formed by laminating eight sheets U10 to U16 and U178 is protected by a dicing tape or the like and then separated for each chip by a dicing device. . At this time, a large number of camera modules 500 are completed.

<Lens drive in camera module>
In the camera module 500, as described above, the lens group 20 is pressed against the lens position adjusting layer 16 by the elastic force of the first and second parallel springs 12 and 14 in the non-driven state, and the lens group 20 Is placed in the initial position. At this time, the camera module 500 focuses on a subject located at infinity with the camera module 500 as a reference.

  And the beam part 151 of the actuator layer 15 deform | transforms, and the free end FT pushes the 1st projection part 201 to + Z direction. The beam 151 pushes up the lens group 20 in the + Z direction against the elastic force of the first and second parallel springs 12 and 14. At this time, the distance between the lens group 20 and the image sensor 181 is changed, and auto-focus (AF) control capable of focusing on subjects located at various distances with the camera module 500 as a reference is realized. Is done.

  As described above, the actuator element layer 1503 contracts and deforms due to heating by energization of the heater layer 1505 provided in the actuator layer 15. Then, the free end FT of the beam portion 151 is displaced in the + Z direction. Note that the amount of displacement generated on the free end FT side of the beam portion 151 varies depending on the heating temperature of the SMA, and the amount of displacement is adjusted by controlling the amount of current supplied to the heater layer 1505. Here, since the electric resistance of the heater layer 1505 also changes in accordance with the deformation of the heater layer 1505 accompanying the deformation of the SMA, the current resistance value of the heater layer 1505 is monitored, and the displacement amount of the free end FT, that is, the lens It is possible to control the displacement amount of the group 20.

  In the camera module 500, the thickness along the Z axis of the first frame layer 11 ensures a space in which the lens group 20 moves, that is, a movable range (stroke) along the Z axis of the lens group 20. The extension distance along the Z axis of the second protrusion 202 is such that the lens group 20 is pushed up in the + Z direction when the lens position adjusting layer 16 is bonded to the actuator layer 15 and the lens group 20. Is equal to or greater than the total of the distance movable in the + Z direction (movable distance).

<Temperature distribution and deformation of the beam>
Hereinafter, the temperature distribution in the beam portion 151 (example) of the actuator layer 15 incorporated in the camera module 500 and the simulation result performed on the deformation mode will be described.

  This simulation was performed using ANSYS (registered trademark), which is a finite element method analysis program. In this simulation, it is assumed that the first protrusion 201 applies a stress that pushes the vicinity of the free end FT of the beam 151 in the −Z direction in accordance with various conditions relating to the actual camera module 500. Further, regarding the size of the beam portion 151, the extension distance (length) is about 4 mm, the width is about 0.3 mm, the thickness is about 0.04 mm, and the diameter of the first protrusion 201 is about 0.00 mm. It was 3 mm. For the heater layer 1505, the material was platinum, the thickness was about 200 nm, and the line width (thickness) was about 5 to 30 μm. Specifically, the line width of the heater layer 1505 was gradually increased in the range of about 5 to 30 μm from the vicinity of the fixed end ST to the vicinity of the free end FT so as to be proportional to the distance from the fixed end ST. Further, the temperature around the beam portion 151 (environmental temperature) is set to about 25 ° C. (room temperature), and 0.3 seconds after the voltage is applied to the heater layer 1505 so that the free end FT performs a desired displacement. The state was analyzed.

  Further, here, as shown in FIG. 34, a heater layer 1505 is a constant heater layer 1505CM having a line width of about 30 μm, and a beam portion (comparative example) 151CM in which other conditions are the same as those in the above-described embodiment. For the provided actuator layer 15CM, a simulation was performed on the temperature distribution similar to that of the example and the deformation mode.

<Simulation results according to example>
FIG. 35 is a diagram illustrating a simulation result of the shape of the beam portion 151 according to the example. FIG. 35 is a view of the shape of the beam portion 151 viewed from the side, and the direction indicated by the arrow AR1 corresponds to the + Z direction. FIG. 36 is a diagram illustrating a simulation result of the temperature distribution of the beam portion 151 according to the example. In FIG. 36, the horizontal axis indicates the distance from the fixed end ST, the vertical axis indicates the temperature, and the temperatures at points P0 to P9 in FIG. 35 are indicated by black circles.

  As shown in FIG. 35, the shape of the beam portion 151 was displaced in the + Z direction according to the distance from the fixed end ST. That is, good displacement of the beam portion 151 was obtained.

  As shown in FIG. 36, the temperature distribution of the beam portion 151 has a tendency that the temperature simply rises from the fixed end ST to the free end FT, but the temperature change range is about 30 ° C. ( Specifically, the temperature was within a relatively narrow temperature range of about 105 to 135 ° C.

<Simulation results according to comparative example>
FIG. 37 is a diagram illustrating a simulation result of the shape of the beam portion 151CM according to the comparative example. FIG. 37 is a view of the shape of the beam portion 151CM viewed from the side as in FIG. 35, and the direction indicated by the arrow AR1 corresponds to the + Z direction. FIG. 38 is a diagram illustrating a simulation result of the temperature distribution of the beam portion 151CM according to the comparative example. In FIG. 38, as in FIG. 36, the horizontal axis indicates the distance from the fixed end ST, the vertical axis indicates the temperature, and the temperatures at points Pc0 to Pc9 in FIG. 37 are indicated by black circles.

  As shown in FIG. 37, regarding the shape of the beam portion 151CM, the portion near the fixed end ST of the beam portion 151CM is hardly displaced, and the central portion of the beam portion 151CM (the fixed end ST and the free end FT The middle part) was slightly displaced in the −Z direction, and the portion close to the free end FT was relatively greatly displaced in the + Z direction. In other words, in the beam portion 151CM, the vicinity of the central portion is recessed, and a displacement in the + Z direction that should originally occur over the entire region of the beam portion 151CM cannot be obtained.

  As shown in FIG. 38, the temperature distribution of the beam portion 151CM is rapidly increased from about 30 ° C. to about 140 ° C. from the fixed end ST to the vicinity of the center portion (middle between the fixed end ST and the free end FT). The temperature rose to a relatively high temperature (about 140 to 155 ° C.) from the vicinity of the central portion (middle between the fixed end ST and the free end FT) to the free end FT. That is, the vicinity of the fixed end ST in contact with the frame body 142 is not sufficiently heated as compared with the vicinity of the free end FT, and conversely, it is overheated from the vicinity of the central portion to the free end FT.

<Comparison of Examples and Comparative Examples>
As shown in FIG. 37 and FIG. 38, in the comparative example, although heat is applied substantially uniformly from the heater layer 1505CM in almost the entire region of the beam portion 151CM, the beam portion varies depending on the heat dissipation property of each region. The heat distribution at 151 CM was non-uniform. Since the beam portion 151CM is displaced in a direction different from the desired direction, the beam portion 151CM is overheated from the central portion to the free end FT in order to realize the desired displacement. For this reason, a stress exceeding a predetermined allowable range is applied to the SMA, and there is a possibility that the original function is lost due to the SMA forgetting the memory shape.

  On the other hand, as shown in FIG. 35 and FIG. 36, in the embodiment, the closer to the fixed end ST that has relatively high heat dissipation, the larger the amount of heat from the heater layer 1505. Is granted. For this reason, compared with the heat distribution which concerns on a comparative example, the heat distribution in the beam part 151 was remarkably equalized. As a result, a satisfactory displacement in which each region of the beam portion 151 is displaced in the + Z direction according to the distance from the fixed end ST is realized. Therefore, the desired displacement can be realized while suppressing the occurrence of problems such as breakage and deterioration of characteristics of the beam portion 151 that lose its original function.

  As described above, in the camera module 500 according to the embodiment of the present invention, the heat distribution of the heater layer 1505 is adjusted according to the heat dissipation property of the beam portion 151, so that the heat distribution in the beam portion 151 is made uniform. Figured. For this reason, it is possible to provide an actuator (in this case, the actuator layer 15) capable of realizing a desired displacement while suppressing destruction and deterioration of characteristics.

  And the amount of heat generated by the heater layer 1505 increases as the beam portion 151 moves away from the fixed frame body 152. Specifically, the electrical resistance per predetermined region of the heater layer 1505 is reduced as the beam portion 151 is further away from the fixed frame body 152. For this reason, the heat distribution in the beam portion 151 can be made uniform.

  Furthermore, the electrical resistance of the heater layer 1505 per predetermined area in the beam portion 151 is adjusted by the thickness (specifically, line width) of the heater layer 1505. With such a configuration, the heat distribution in the beam portion 151 can be made uniform easily.

<Modification>
It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

  For example, in the embodiment described above, the electric resistance of the heater layer 1505 per predetermined region of the beam portion 151 is adjusted by the line width of the heater layer 1505, but is not limited thereto. For example, the electrical resistance of the heater layer per predetermined region of the beam portion may be adjusted by appropriately changing the thickness of the heater layer or the density at which the heater layer is disposed. Hereinafter, a specific example (specifically, a first modification and a second modification) will be shown and described.

<First Modification>
In the actuator layer 15A according to the first modification, the electric resistance of the heater layer 1505A per predetermined region of the beam portion 151A is adjusted by changing the thickness of the heater layer 1505A.

  FIG. 39 is a diagram illustrating a detailed configuration of one main surface of the actuator layer 15A according to the first modification. 40 is a schematic cross-sectional view taken along section line C40-C40 of FIG. 39, focusing on the beam portion 151A of the actuator layer 15A.

  The actuator layer 15A is changed from the heater layer 1505 to a heater layer 1505A having a different shape as compared to the actuator layer 15 according to the above-described embodiment, and the beam portion 151 is changed to the beam portion 151A in accordance with this change. Is. As a result of this configuration change, the optical unit KB is changed to the optical unit KBA, the camera module 500 is changed to the camera module 500A, the first casing 200 is changed to the first casing 200A, and the mobile phone 100 is changed. Is changed to the mobile phone 100A. Moreover, the actuator layer sheet | seat U15 for forming the actuator layer 15 which concerns on the said one embodiment is changed into the actuator layer sheet | seat U15A (FIG. 25) by the change of the said structure. Further, since the other configuration of the actuator layer 15A is the same as the configuration of the actuator layer 15 according to the above-described embodiment, the same reference numerals are given and description thereof is omitted. In the first modification, the beam portion 151A corresponds to the “movable portion” of the present invention, and the heater layer 1505A corresponds to the “third layer” and the “heat generating portion” of the present invention.

  As shown in FIG. 39 and FIG. 40, the heater layer 1505A has a constant line width (line width), and has a thickness in the Z direction that is increased according to the separation distance from the frame 152. If the thickness of the heater layer 1505A is relatively thick, the thickness of the heater layer 1505A is relatively thick, and the electrical resistance of the heater layer 1505A is relatively reduced. It is preferable that the sectional area of the heater layer 1505A in the vicinity of the free end FT is set to be about 5 to 10 times the sectional area of the heater layer 1505A in the vicinity of the fixed end ST.

  Here, as in the above embodiment, the electricity of the heater layer 1505A disposed in each region (predetermined region) in which the other main surface of the beam portion 151A is divided into sections of the same area from the fixed end ST to the free end FT. Think of resistance. In the beam portion 151A, the electric resistance of the heater layer 1505A per predetermined region of the beam portion 151A is adjusted by the thickness of the heater layer 1505A. Specifically, the electric resistance of the heater layer 1505A per predetermined region of the beam portion 151A is reduced as the region is farther from the frame body 152 in the beam portion 151A. Therefore, in the beam portion 151A, as in the beam portion 151 of the above-described one embodiment, when the voltage is applied to the heater layer 1505A and energized, the more the region is farther from the frame body 152, the more The amount of heat generated by the heater layer 1505A is reduced.

  That is, in the actuator layer 15A according to the first modified example, as in the actuator layer 15 of the above-described embodiment, when the beam portion 151A has a higher heat dissipation property, the heater layer 1505A is energized. In addition, the heat generation amount of the heater layer 1505A per predetermined region of the beam portion 151A is increased.

  For example, when the beam portion 151A is equally divided into three regions from the fixed end ST to the free end FT, the first region on the fixed end ST side, the second region in the middle, and the third region on the free end FT side It is divided into and. The electric resistance of the heater layer 1505A in the first region is the highest, the electric resistance of the heater layer 1505A in the third region is the lowest, and the electric resistance of the heater layer 1505A in the order of the first region, the second region, and the third region. Is set to be low. That is, when a voltage is applied to the heater layer 1505A and energized, the heat generation amount of the heater layer 1505A in the first region is the largest, and the heat generation amount of the heater layer 1505A in the third region is the smallest. The amount of heat generated by the heater layer 1505A decreases in the order of the second region and the third region.

  The actuator layer 15A is manufactured by applying, for example, a photolithography technique frequently used in a semiconductor manufacturing process, similarly to the actuator layer 15 of the above-described embodiment. Note that, as a method of changing the thickness of the metal heater layer 1505A, for example, a method of changing the time for depositing metal using a mask or the like according to the distance from the portion corresponding to the frame body 152 can be given. It is done. However, it is not easy to vary the thickness of the heater layer 1505A continuously and gradually according to the distance from the frame 152. For this reason, considering the ease of manufacturing, for example, the time during which the metal is deposited is varied in a plurality of stages (three stages, etc.), and in a plurality of stages (three stages, etc.) according to the distance from the frame 152. It is preferable to employ a configuration in which the thickness of the heater layer 1505A is changed stepwise.

  As described above, in the actuator layer 15A according to the first modification, the thickness of the heater layer 1505A is adjusted, so that the heat distribution in the beam portion 151A can be easily made uniform.

<Second Modification>
In the actuator layer 15B according to the second modification, the electric resistance of the heater layer 1505B per predetermined region of the beam portion 151B is adjusted by the arrangement density of the heater layers 1505B per predetermined region of the beam portion 151B.

  FIG. 41 is a diagram illustrating a detailed configuration of one main surface of the actuator layer 15B according to the second modification.

  Compared with the actuator layer 15 according to the above-described embodiment, the actuator layer 15B has the heater layer 1505 changed to a heater layer 1505B having a different shape, and the beam portion 151 has been changed to the beam portion 151B in accordance with this change. Is. By this change in configuration, the optical unit KB is changed to the optical unit KBB, the camera module 500 is changed to the camera module 500B, the first casing 200 is changed to the first casing 200B, and the mobile phone 100 is changed. Is changed to the mobile phone 100B. Moreover, the actuator layer sheet | seat U15 for forming the actuator layer 15 which concerns on the said one embodiment is changed into the actuator layer sheet | seat U15B (FIG. 25) by the change of the said structure. Further, since the other configuration of the actuator layer 15B is the same as the configuration of the actuator layer 15 according to the above-described embodiment, the same reference numerals are given and description thereof is omitted. In the second modification, the beam portion 151B corresponds to the “movable portion” of the present invention, and the heater layer 1505B corresponds to the “third layer” and the “heat generating portion” of the present invention.

  As shown in FIG. 41, the heater layer 1505B has a constant line width (line width) and thickness, but has a density (arrangement density) arranged according to the separation distance from the frame body 152. It is low. Specifically, the heater layer 1505B is arranged to meander on the other main surface side of the beam portion 151B, and the frequency of meandering is adjusted, so that the heater layer 1505B is a region near the frame body 152 in the beam portion 151B. It is adjusted so that the arrangement density of the heater layer 1505B becomes higher as there is more. It is preferable that the arrangement density of the heater layer 1505B in the vicinity of the fixed end ST is set to be about 5 to 10 times the arrangement density of the heater layer 1505B in the vicinity of the free end FT.

  Here, as in the above embodiment, the electricity of the heater layer 1505B disposed in each region (predetermined region) in which the other main surface of the beam portion 151B is divided into sections of the same area from the fixed end ST to the free end FT. Think of resistance. In the beam portion 151B, the electric resistance of the heater layer 1505B per predetermined region of the beam portion 151B is adjusted by the arrangement density of the heater layer 1505B. Specifically, the closer to the frame 152 in the beam portion 151B, the lower the electric resistance of the heater layer 1505B per predetermined region of the beam portion 151B. Accordingly, in the beam portion 151B, as in the beam portion 151 of the above-described embodiment, when a voltage is applied to the heater layer 1505B and energized, the more the region is farther from the frame body 152, the more the region per predetermined region is. The amount of heat generated by the heater layer 1505B increases.

  That is, in the actuator layer 15B according to the second modified example, when the beam portion 151B is a region having higher heat dissipation, the heater layer 1505B is energized as in the actuator layer 15 of the above-described embodiment. In addition, the amount of heat generated by the heater layer 1505B per predetermined area of the beam portion 151B is reduced.

  For example, when the beam portion 151B is equally divided into three regions from the fixed end ST to the free end FT, the first region on the fixed end ST side, the second region in the middle, and the third region on the free end FT side It is divided into and. The electric resistance of the heater layer 1505B in the first region is the highest, the electric resistance of the heater layer 1505B in the third region is the lowest, and the electric resistance of the heater layer 1505B in the order of the first region, the second region, and the third region. Is set to be low. That is, when a voltage is applied to the heater layer 1505B and energized, the heat generation amount of the heater layer 1505B in the first region is the largest, and the heat generation amount of the heater layer 1505B in the third region is the smallest. The amount of heat generated by the heater layer 1505B decreases in the order of the second region and the third region.

  The actuator layer 15B is manufactured by applying, for example, a photolithography technique frequently used in a semiconductor manufacturing process, similarly to the actuator layer 15 of the above-described embodiment.

  As described above, in the actuator layer 15B according to the second modification, the distribution of the heater layers 1505B is adjusted, so that the heat distribution in the beam portion 151B can be easily made uniform.

<Other variations>
In the above-described embodiment, one end of the beam portion 151 is the fixed end ST and the other end is the free end FT. However, the present invention is not limited to this. The present invention can also be applied to, for example, a beam portion in which both ends are fixed to the frame and the center portion is displaced most. Thus, when both ends are fixed ends, both ends of the beam portion are relatively higher in heat dissipation than the center portion of the beam portion. For this reason, according to heat dissipation, it should just be comprised so that the emitted-heat amount of a heater layer may become small, so that it approaches the center part from a fixed end.

  In the above-described embodiment, the lens group 20 includes the first and second lenses G1 and G2. However, the present invention is not limited to this. For example, the lens group 20 may be an optical system having one lens. . That is, the optical system that is the moving object may include one or more optical lenses.

  In the above-described embodiment, the focus control is performed by moving the lens group 20. However, the present invention is not limited to this. For example, a so-called zoom operation may be realized by moving the lens group 20.

  In the above-described embodiment, the actuator element layer 1503 is configured using SMA, but is not limited thereto. For example, the actuator layer 15 may be configured by stacking three or more layers, one layer generating heat, and the other two layers expanding or contracting differently depending on heating. .

  Specifically, for example, so-called bimetal (Bi-metallic strip) may be applied. That is, in the actuator layer, a so-called bimetal configuration is formed by a layer constituted by the first material and a layer constituted by the second material having a different thermal expansion coefficient (linear expansion coefficient) from the first material. It may be realized.

  Specifically, there is a configuration in which a layer (metal layer) of a metal material such as aluminum or nickel is formed on one main surface side of a silicon substrate. In such a configuration, when the substrate and the metal layer are heated by energization of the heater layer, the beam portion is deformed due to the difference in thermal expansion coefficient, and the free end of the beam portion is displaced in the + Z direction.

  And also when applying a bimetal to an actuator layer, the effect similar to the said one embodiment is acquired. Specifically, when a bimetal is applied to the actuator layer, in order to realize a desired displacement, the actuator layer is heated too much, and the bimetal is plastically deformed beyond the elastic deformation region. There is a possibility that the original function of the is impaired. However, the heat distribution in the beam portion can be made uniform by adjusting the amount of heat generated by the heater layer in accordance with the heat radiation property in the beam portion. For this reason, overheating in the actuator layer is suppressed. As a result, it is possible to provide an actuator capable of realizing a desired displacement while suppressing destruction and deterioration of characteristics.

  The actuator element layer may be formed of a thin film (piezoelectric thin film) of a piezoelectric element such as an inorganic piezoelectric material (PZT) or an organic piezoelectric material (PVDF).

  In the above embodiment, the actuator layer is manufactured using so-called photolithography, but at least a part of the plurality of layers constituting the actuator layer may be manufactured using photolithography. . Note that as a technique for performing microfabrication without using photolithography, an evaporation method using a desired mask pattern, or the like can be given.

  In the embodiment described above, the plate-like first and second parallel springs 12 and 14 are employed as members for restricting the movement of the lens group 20, but the present invention is not limited to this. For example, various elastic members including a helical spring may be employed.

  In the above embodiment, the object moved by the beam 151 (moving object) is the lens group 20 that is a so-called optical system, but is not limited thereto. For example, other members such as an image sensor may be used as the moving object. For example, the lens group 20d corresponding to the optical system that guides light from the subject to the image sensor may be fixed, and the image sensor layer may be moved in the Z direction by a configuration similar to the configuration in which the lens group 20 is moved in the one embodiment. . Even with such a configuration, a desired displacement can be realized while suppressing destruction and deterioration of characteristics as in the above-described embodiment.

  FIG. 42 is a diagram illustrating a conceptual diagram of an aspect in which the lens group 20d is fixed and the imaging element layer 18d is moved back and forth in a direction along the optical axis Ax of the lens group 20d. In FIG. 42, an imaging unit PBD that moves the imaging element layer 18d back and forth along the optical axis Ax is depicted. In such a configuration, the image pickup element layer 18d is moved back and forth along the optical axis Ax according to the operation of the actuator layer, and the distance between the lens group 20d and the image pickup element layer 18d is changed. Control is realized. As described above, when at least one of the image sensor and the optical system is moved in accordance with the bending of the beam portion, the autofocus control is realized.

  Moreover, the target object (moving target object) moved by the actuator is not limited to an element constituting the imaging apparatus such as an optical system or an imaging element. For example, the moving object may be another object such as an objective lens of an optical pickup lens. That is, the present invention can be applied to an actuator and a driving device in which a moving object is moved according to the bending of the actuator.

  It goes without saying that all or a part of each of the above-described embodiment and various modifications can be appropriately combined within a consistent range.

DESCRIPTION OF SYMBOLS 10 Lid layer 11 1st frame layer 12 1st parallel spring 13 2nd frame layer 14 2nd parallel spring 15, 15A, 15B Actuator layer 16 Lens position adjustment layer 17 Cover glass layer 18, 18d Image pick-up element layer 20 Lens group 151, 151A, 151B Beam 181 Image sensor 500, 500A, 500B Camera module 1501 Substrate 1502, 1504 Insulating layer 1503 Actuator element layer 1505, 1505A, 1505B Heater layer FT Free end KB, KBA, KBB Optical unit PB, PBD Image sensor ST Fixed end

Claims (12)

An actuator for moving a moving object,
A movable part in which a predetermined part is displaced;
A reference portion on which the movable portion is fixed;
With
The movable part is
A plurality of layers including a first layer, a second layer that expands or contracts different from the first layer in response to heating, and a third layer that generates heat are stacked and configured to have high heat dissipation. The region is configured such that the amount of heat generated by the third layer per predetermined region of the movable part increases.
The actuator according to claim 1, wherein the predetermined portion is displaced by bending of the movable portion in response to heat generation of the third layer. The actuator according to claim 1,
The movable part is
The actuator configured to reduce the amount of heat generated by the third layer per predetermined area as the area is farther from the reference portion. The actuator according to claim 1 or 2,
The third layer includes a heat generating part that generates heat in response to energization,
The actuator characterized in that the electrical resistance of the heat generating part per predetermined area of the movable part is reduced in a region away from the reference part of the movable part. The actuator according to claim 3, wherein
The actuator according to claim 1, wherein the electric resistance of the heat generating part per predetermined area of the movable part is adjusted by the thickness of the heat generating part. The actuator according to claim 4, wherein
The actuator, wherein a thickness of the heat generating part is adjusted by a width of the heat generating part. The actuator according to claim 4, wherein
The actuator, wherein the thickness of the heat generating part is adjusted by the thickness of the heat generating part. The actuator according to claim 3, wherein
The actuator, wherein an electrical resistance of the heat generating portion per predetermined area of the movable portion is adjusted by an arrangement density of the heat generating portions per predetermined region of the movable portion. The actuator according to any one of claims 1 to 7,
The actuator, wherein the second layer contains a shape memory alloy. The actuator according to any one of claims 1 to 7,
The first layer includes a first material;
The actuator, wherein the second layer includes a second material having a linear expansion coefficient different from that of the first material. The actuator according to any one of claims 1 to 9, wherein
An actuator, wherein at least a part of the first layer, the second layer, and the third layer is manufactured using photolithography. The actuator according to any one of claims 1 to 10, and
A moving object that is moved according to the bending of the movable part;
A drive device comprising: The actuator according to any one of claims 1 to 10, and
An image sensor;
An optical system for guiding light from a subject to the image sensor;
With
An imaging apparatus, wherein at least one of the imaging element and the optical system is moved according to the bending of the movable part.

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