JP5402277B2 - Actuator, drive device, and imaging device - Google Patents

Description

  The present invention relates to an actuator, and a drive device and an imaging device equipped with the actuator.

  In recent years, camera modules are often mounted on small electronic devices such as mobile phones, and further miniaturization of camera modules is aimed at.

  With regard to this camera module, conventionally, a lens barrel and a lens holder that support a lens, a holder that supports an infrared (IR) cut filter, a substrate, an image sensor, and an optical element, and a housing that holds the stack. There is a need for a body and a resin for sealing the laminate. Therefore, it is not easy to produce a camera module by accurately combining a large number of components while reducing the size of the large number of components.

  Therefore, a laminated member is formed by pasting a substrate, a semiconductor sheet on which a large number of imaging elements are formed, and a lens array sheet on which a large number of imaging lenses are formed via a resin layer, and the laminated member is diced. A technique for completing individual camera modules has been proposed (for example, Patent Document 1). With this technology, it is possible to cut out several hundred camera modules from a single wafer-like laminated member, and matching with a fine processing process is also good. For this reason, it is considered that the camera module greatly contributes to miniaturization, thinning, and cost reduction.

  However, in the technique disclosed in Patent Document 1, it is difficult to dispose an actuator that forms a part (movable part) for moving the imaging lens, such as a voice coil motor, because wafer-like members are stacked. Accordingly, it has been difficult to incorporate autofocus and zoom functions into a small camera module.

  By the way, an actuator using a shape memory alloy can be considered as an actuator applicable to a small camera module (for example, Patent Document 2). The actuator using this shape memory alloy can obtain a very large force even if it is small in size, and the response that is a general problem because the ratio of the surface area to the volume increases with the downsizing. Therefore, it can be said that matching with a small camera module is good.

JP 2007-12995 A JP 2008-19751 A

  However, a compact actuator is required to have a configuration that can withstand power consumption and withstand impact and external force loads. However, Patent Document 2 does not consider countermeasures for these requirements.

  The present invention has been made in view of the above-described problems, and provides an actuator that can withstand an impact or an external force load while suppressing power consumption, and a drive device and an imaging device equipped with the actuator. The purpose is to provide.

In order to solve the above-described problem, an actuator according to a first aspect is configured using a film-shaped shape memory alloy, generates a heat in response to energization, and deforms in response to the heat generation, and the movable First and second members to which the part is fixed, and recognition means for recognizing the displacement of the movable part by detecting the electrical resistance of the movable part , wherein the first member is substantially parallel to each other. And is included in a plate-shaped fixed frame body having two substantially flat main surfaces, and a part of the shape memory alloy of the movable part is on the main surface of the fixed frame body on the fixed frame body The first member is fixed to the first member by being formed into a film shape along the first and second sides so that the movable part reciprocates at least once between the first member and the second member. Ru Tei is bridged between the and the member second member.

The actuator according to the second aspect is the actuator according to the first aspect, wherein the first and second members are respectively included in the fixed frame, and the fixed frame is the two main elements. has a hollow portion passing through the surface, the movable part, that is bridged so as to cross the hollow portion.

Third driving apparatus according to the embodiment of the comprises an actuator according to the second aspect, and a moving object to contact via the abutment or another member relative to the movable portion.

The actuator according to the fourth aspect, an actuator according to the first aspect, before Symbol second member is a moving member that moves relative to the first member.

The actuator which concerns on a 5th aspect is an actuator which concerns on a 4th aspect, Comprising: The said 1st member is provided in the circumference | surroundings of the said 2nd member through the hollow part , and the said movable part is a said 2nd member. Is installed between the first member and the second member so as to straddle the hollow portion at substantially equal intervals.

Sixth driving apparatus according to the embodiment of the comprises an actuator according to the fourth or fifth aspect, a mobile object to be fixed to the second member.

An imaging device according to a seventh aspect includes the actuator according to any one of the second , fourth , and fifth aspects, an imaging element, and an optical system that guides light from a subject to the imaging element, At least one of the image sensor and the optical system is moved by deformation of the movable part.

An imaging device according to an eighth aspect is the imaging device according to the seventh aspect, and has an annular shape having an imaging element holding member that holds the imaging element and a hollow portion in which the optical system is disposed. The imaging element holding member and the annular member are plate-like members each having two substantially flat main surfaces that are substantially parallel to each other, the imaging element holding member and the annular member An annular member and the actuator are stacked .

The actuator according to any one of the first , second , fourth , and fifth aspects allows the movable portion to have a longer arrangement path while maintaining the cross-sectional area of the movable portion, so Therefore, an actuator that can withstand a load of an impact or an external force while suppressing power consumption can be provided.

According to the actuator according to the first aspect, since the amount of change in the electrical resistance value with respect to the displacement relating to the movable portion becomes large, the displacement relating to the movable portion can be accurately recognized regardless of the influence of the disturbance. .

With the drive device according to any of the third and sixth aspects, it is possible to provide a drive device equipped with an actuator that can withstand an impact or an external force load while suppressing power consumption.

According to the actuator which concerns on a 5th aspect, since a moving member is supported by a movable part, manufacture of an actuator becomes easy by simplification of a structure and a manufacturing process.

According to the imaging device according to the seventh aspect, it is possible to provide an imaging device equipped with an actuator capable of withstanding an impact or an external force load while suppressing power consumption.

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 plane external view of an image sensor layer. It is a plane external view of an image sensor holding layer. It is a plane external view of a spacer layer. It is a plane external view of an actuator layer. It is a plane external view of a 1st and 2nd parallel spring layer. It is a plane external view of an imaging lens layer. It is a plane external view of a cover layer. It is a figure which shows the relative arrangement | positioning relationship between an actuator layer and a lens unit. It is a figure for demonstrating operation | movement of the lens unit by the deformation | transformation of SMA. It is a figure for demonstrating operation | movement of the lens unit by the deformation | transformation of SMA. It is a figure for demonstrating the function of a 1st and 2nd parallel spring layer. It is a figure for demonstrating the function of a 1st and 2nd parallel spring layer. It is a flowchart which shows an example of the manufacturing process of a camera module. It is a figure for demonstrating the manufacturing process of a camera module. It is a mimetic diagram concerning the example of composition of the actuator layer concerning one modification. It is a figure for demonstrating operation | movement of the optical lens part which concerns on one modification. It is a figure for demonstrating operation | movement of the optical lens part which concerns on one modification. It is a figure which illustrates the composition which moves the image sensor concerning one modification.

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

<(1) 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 has a plate-like substantially rectangular parallelepiped shape and serves as a casing for storing various electronic members. Specifically, the first casing 200 includes a camera module 500 and a display, and the second casing 300 includes a control unit that electrically controls the mobile phone 100 and an operation member such as a button. Have. In addition, the hinge part 400 connects the 1st housing | casing 200 and the 2nd housing | casing 300 so that rotation is possible. For this reason, the mobile phone 100 can be folded.

  In addition, the current supply driver 600, the electric resistance detection unit 700, and the contrast detection unit 800 are mounted on the first casing 200. The current supply driver 600 controls the supply of current to the shape memory alloy (SMA) film 41 (FIG. 7) of the camera module 500. The electrical resistance detector 700 detects the electrical resistance in the SMA film 41. The contrast detection unit 800 detects the contrast of the image signal obtained by the image sensor 11 (FIG. 3) of the camera module 500. In addition, a focusing control unit 310 is mounted on the second casing 300. The focusing control unit 310 controls the amount of current supplied to the SMA film 41 via the current supply driver 600 in accordance with the input of signals from the electrical resistance detection unit 700 and the contrast detection unit 800, so that the camera module Auto focus control for adjusting the in-focus state of 500 is performed.

  FIG. 2 is a schematic cross-sectional view focusing on the first casing 200 of the mobile phone 100. 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 several mm. (MCU).

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

<(2) Configuration of camera module>
FIG. 3 is a schematic cross-sectional view of the camera module 500. As shown in FIG. 3, the camera module 500 includes an imaging element layer 10, an imaging element holding layer 20, a spacer layer 30, an actuator layer 40, a first parallel spring layer 50, an imaging lens layer 60, and a second parallel spring layer 70. , And 8 layers of the lid layer 80 are laminated in this order. Since the two adjacent layers included in the eight layers are joined by a resin such as an epoxy resin, the resin is interposed between the layers.

  Each of the layers 10 to 80 has a substantially identical rectangular shape (here, a square having a side of about 5 mm) on the surface in the ± Z direction. As will be described later, for the imaging lens layer 60, during the manufacturing of the camera module 500, for example, connecting portions 64a and 64b that connect the fixed frame 60F (FIG. 9) and the protrusions 61a and 61b (FIG. 9). Is cut, and the lens unit 60U including the optical lens portion 63, the protrusions 61a and 61b, and the lens holding portions 62a and 62b and the fixed frame 60F are separated.

  In the camera module 500, the lens unit 60 </ b> U is moved by the actuator layer 40 in a direction along the optical axis PL of the optical lens unit 63 (here, ± Z direction), so that the imaging element 11 and the lens of the imaging element layer 10 are moved. The distance from the unit 60U is changed. By changing the distance, autofocus control in which the in-focus state of the camera module 500 is adjusted is realized.

  The camera module 500 is configured in detail as follows.

  An image sensor holding layer 20 for holding the image sensor layer 10 is disposed on the upper surface (+ Z side surface) of the image sensor layer 10, and a spacer is provided on the upper surface (+ Z side surface) of the image sensor layer 20. Layer 30 is disposed. The spacer layer 30 has a function of securing a space in which the SMA film 41 of the actuator layer 40 is elastically deformed by the depression of the lens unit 60U in the −Z direction by the first and second parallel spring layers 50 and 70.

  In addition, the actuator layer 40, the first parallel spring layer 50, the imaging lens layer 60, and the second parallel spring layer 70 are stacked in this order on the upper surface of the spacer layer 30, thereby moving the optical lens unit 63. Mechanism (moving mechanism) is configured.

  In this moving mechanism, the lens holding portions 62a and 62b of the lens unit 60U are sandwiched from the ± Z direction by the first parallel spring layer 50 and the second parallel spring layer 70, and thus in the direction along the optical axis PL. The mechanism (parallel link mechanism) supported so that a movement is possible is comprised. For this reason, the lens unit 60U does not tilt relative to the fixed frame 60F due to the movement in the ± Z direction. In addition, contact portions 61Ta and 61Tb arranged on the −Z side of the protrusions 61a and 61b of the lens unit 60U come into contact with the SMA film 41 of the actuator layer 40. Therefore, a driving device is formed in which the lens unit 60U is moved in the direction along the optical axis PL in accordance with the deformation of the SMA film 41.

  A lid layer 80 made of a transparent material such as glass is disposed on the upper surface of the second parallel spring layer 70.

  And as above-mentioned, the eight layers 10-80 are mutually joined by adhesive agents, such as an epoxy resin, in an outer peripheral part. For this reason, the camera module 500 forms a sealed space including a space in which the optical lens unit 63 moves. The camera module 500 is manufactured, for example, in a clean room or a clean bench, and is maintained so that dust and dust do not enter the sealed space formed by the camera module 500. As a result, it is possible to suppress the problem that dust or dust adheres to the moving mechanism having a fine gap and the occurrence of air convection in the sealed space. As a result, the variation in load on the drive mechanism is reduced, and the movement accuracy of the optical lens unit 63 is improved.

  In the camera module 500, the image sensor holding layer 20, the spacer layer 30, and the actuator layer 40 are sequentially formed from the upper surface (+ Z side surface) of the image sensor layer 10 to the upper surface of the actuator layer 40 (+ Z side surface). Through holes (through holes) CVa and CVb are provided. The inner diameters of the minute through holes CVa and CVb are set to about several tens of μm, for example. The through holes CVa and CVb are filled with a conductive material, and the imaging element layer 10 and the SMA film 41 of the actuator layer 40 are electrically connected.

<(2-1) Each functional layer>
Below, the detail of each functional layer which comprises the camera module 500 is demonstrated. 4 to 10 are configuration examples of the imaging element layer 10, the imaging element holding layer 20, the spacer layer 30, the actuator layer 40, the first and second parallel spring layers 50 and 70, the imaging lens layer 60, and the lid layer 80. FIG. 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.

<(2-1-1) Image sensor layer>
As shown in FIG. 4, the imaging element layer 10 is a chip including an imaging element 11 formed by, for example, a COMS sensor or a CCD sensor, a peripheral circuit thereof, and an outer peripheral portion 12 surrounding the imaging element 11. Although not shown here, wiring for applying a signal to the image sensor 11 and reading a signal from the image sensor 11 is provided on the back surface (the surface on the −Z side) of the image sensor layer 10. Various terminals for connecting are provided.

  For example, the back surface of the imaging element layer 10 is soldered by a reflow method using a solder ball, so that the imaging element layer 10, the current supply driver 600, the electric resistance detection unit 700, the contrast detection unit 800, etc. Are connected so as to be conductive or capable of transmitting and receiving data.

<(2-1-2) Image sensor holding layer>
The imaging element holding layer 20 is a chip that holds the imaging element layer 10 that is formed of a material such as a resin and attached by bonding.

Specifically, as shown in FIG. 5, an opening 20H having a substantially square cross section is provided along the Z direction at a substantially center of the image sensor holding layer 20, and the cross section of the opening 20H goes to the + Z side. The smaller it becomes. Note that the quadrangle drawn with a broken line in FIG. 5 indicates the outer edge of the opening 20H on the −Z side surface. In addition, minute holes (through holes) CV _2a and CV _2b penetrating along the Z direction are provided in two predetermined portions of the plate-like portion that forms one side of the outer peripheral portion of the imaging element holding layer 20. The through holes CV _2a and CV _2b are filled with a conductive material. The opening 20H and the through holes CV _2a and CV _2b are formed by, for example, embossing.

  Furthermore, one main surface and the other main surface of the image sensor holding layer 20 are substantially flat, and the one main surface and the other main surface are in a substantially parallel relationship. One main surface of the outer peripheral portion of the image sensor holding layer 20 is bonded to the adjacent image sensor layer 10, and the other main surface of the outer peripheral portion is bonded to the adjacent spacer layer 30.

<(2-1-3) Spacer layer>
The spacer layer 30 is a chip that is formed of, for example, a material such as resin and secures a moving space for the lens unit 60U.

Specifically, as shown in FIG. 6, each of the outer edge and the inner edge has an annular shape having a rectangular shape, and has a hollow portion 30 </ b> H penetrating in the Z direction. Similarly to the image sensor holding layer 20, minute holes (through holes) CV _3a and CV _3b penetrating along the Z direction are provided at two predetermined portions of the rod-shaped portion forming one side of the spacer layer 30. The through holes CV _3a and CV _3b are filled with a conductive material. The hollow portion 30H and the through holes CV _3a and CV _3b are formed by, for example, embossing.

  Further, one main surface and the other main surface of the spacer layer 30 are substantially flat, and the one main surface and the other main surface are in a substantially parallel relationship. Then, one main surface of the spacer layer 30 is bonded to the adjacent image sensor holding layer 20, and the other main surface is bonded to the adjacent actuator layer 40.

<(2-1-4) Actuator layer>
As shown in FIG. 7, the actuator layer 40 includes a fixed frame body 40 </ b> F, electrode portions 40 </ b> Ea and 40 </ b> Eb, and an SMA film 41.

  The fixed frame 40F is formed of a material that is not a conductor, such as silicon. The fixed frame body 40F has an annular shape in which the outer edge and the inner edge are each rectangular, and has a hollow portion 40H penetrating in the Z direction. From another point of view, the fixed frame 40F includes plate-like portions (plate-like portions) 40Fa and 40Fc extending in the X direction and facing each other, and plates extending in the Y direction and facing each other. Shaped portions (plate-like portions) 40Fb and 40Fd. The fixed frame body 40F has a shape such that the four plate-like portions 40Fa to 40Fd are connected in this order. Note that the fixed frame body 40F constitutes the outer peripheral portion of the camera module 500 and functions as a fixing member in the camera module 500.

Similarly to the image sensor holding layer 20 and the spacer layer 30, minute holes (through holes) CV _4a and CV _4b penetrating along the Z direction are provided at two predetermined positions of the plate-like portion 40Fa. The through holes CV _4a and CV _4b are filled with a conductive material. Here, the through holes CV _4a and CV _4b and the hollow portion 40H are formed by various etchings or the like.

Here, the conductive material filled in the through hole CV _4a is electrically connected to the conductive material filled in the through holes CV _2a and CV _3a , and the conductive material filled in the through hole CV _4b is the through hole CV. _2b and CV _3b are electrically connected to the conductive material filled. Specifically, the through hole CVa is formed by the through holes CV _{2a to} CV _4a , and the through hole CVb is formed by the through holes CV _{2b to} CV _4b . The through holes CVa and CVb are filled with a conductive material, whereby through wirings are formed. The imaging element layer 10 and the actuator layer 40 are electrically connected by the through wiring. The electrical connection between the imaging element layer 10 and the actuator layer 40 can also be realized by providing wiring on the side surface of the camera module 500 using a printing technique or the like.

The two electrode portions 40Ea and 40Eb are provided apart from each other on the other main surface of the plate-like portion 40Fa. Specifically, the electrode portion 40Ea is provided on one main surface side of the through hole CV _4a , and the electrode portion 40Eb is provided on the other main surface side of the through hole CV _4b .

  The SMA film 41 is configured using a shape memory alloy (SMA). The SMA film 41 includes a first movable part 41a and a second movable part 41b. The first movable portion 41a includes three beam portions 411a to 413a and first and second connection portions C1 and C2, and the second movable portion 41b includes the three beam portions 411b to 413b and the fourth and fourth portions. It is comprised by 5 connection part C4, C5. And each beam part 411a-413a, 411b-413b is constructed between the plate-shaped part 40Fa and plate-shaped part 40Fc which mutually oppose. That is, the plate-like portion 40Fa and the plate-like portion 40Fc function as members to which the beam portions 411a to 413a and 411b to 413b are fixed.

  The first, third, and fifth connecting portions C1, C3, and C5 are provided on the other main surface of the plate-like portion 40Fc, and the second and fourth connecting portions C2 and C4 are provided on the other main surface of the plate-like portion 40Fa. Provided on top.

  Specifically, one end portion of the beam portion 411a is electrically connected to the electrode portion 40Ea by being formed on the electrode portion 40Ea. The other end portion of the beam portion 411a is electrically connected to one end portion of the beam portion 412a by the first connection portion C1 on the other main surface of the plate-like portion 40Fc. The other end portion of the beam portion 412a is electrically connected to one end portion of the beam portion 413a by the second connection portion C2 on the other main surface of the plate-like portion 40Fa. The other end portion of the beam portion 413a is electrically connected to one end portion of the beam portion 411b by the third connection portion C3 on the other main surface of the plate-like portion 40Fc. The other end portion of the beam portion 411b is electrically connected to one end portion of the beam portion 412b by the fourth connection portion C4 on the other main surface of the plate-like portion 40Fa. The other end portion of the beam portion 412b is electrically connected to one end portion of the beam portion 413b by the fifth connection portion C5 on the other main surface of the plate-like portion 40Fc. And the other end part of the beam part 413b is electrically connected with respect to this electrode part 40Eb by being formed on the electrode part 40Eb.

  That is, the first movable portion 41a is reciprocated halfway between the plate-like portion 40Fa and the plate-like portion 40Fc by the three beam portions 411a to 413a and the first and second connection portions C1 and C2. It is constructed between the plate-like portion 40Fa and the plate-like portion 40Fc. Further, the second movable portion 41b is reciprocated halfway between the plate-like portion 40Fa and the plate-like portion 40Fc by the three beam portions 411b to 413b and the fourth and fifth connection portions C4 and C5. It is constructed between the plate-like portion 40Fa and the plate-like portion 40Fc.

  In the SMA film 41, the extension distance of the third connection part C3 of the first to fifth connection parts C1 to C5 is set to be several tens of times longer than the extension distance of the other connection parts. The first movable part 41a and the second movable part 41b are relatively separated from each other.

  As described above, the SMA film 41 includes the beam portion 411a, the first connection portion C1, the beam portion 412a, the second connection portion C2, the beam portion 413a, and the third connection portion C3 between the electrode portion 40Ea and the electrode portion 40Eb. The beam portion 411b, the fourth connection portion C4, the beam portion 412b, the fifth connection portion C5, and the beam portion 413b are electrically connected in series. Therefore, when a voltage is applied between the electrode part 40Ea and the electrode part 40Eb, a current flows through the SMA film 41. At this time, the first and second movable parts 41a and 41b generate heat due to Joule heat generated in response to energization and deform in response to the heat generation.

  Further, one main surface and the other main surface of the actuator layer 40 are substantially flat, and the one main surface and the other main surface are in a substantially parallel relationship. Then, one main surface of the actuator layer 40 is bonded to the adjacent spacer layer 30 and the other main surface is bonded to the adjacent first parallel spring layer 50. In addition, between the SMA film | membrane 41 and the 1st parallel spring layer 50, resin etc. which are used for joining interpose, and between the electrode parts 40Ea and 40Eb and the SMA film | membrane 41 and the 1st parallel spring layer 50 are used. It is configured so as not to cause a short circuit. However, from the viewpoint of preventing a short circuit between the electrode portions 40Ea and 40Eb and the SMA film 41 and the first parallel spring layer 50, the first parallel spring layer 50 of the other main surfaces of the actuator layer 40 is joined. It is preferable that an insulating film is formed on the portion.

<(2-1-5) First and second parallel spring layers>
Since the first and second parallel spring layers 50 and 70 have the same configuration, the first parallel spring layer 50 will be specifically described here as an example.

  As shown in FIG. 8, the first parallel spring layer 50 is an elastic member having a fixed frame body 50F and an elastic portion 51, and is a layer (elastic layer) forming a spring mechanism. As a material of the first parallel spring layer 50, for example, a metal material such as stainless steel, phosphor bronze, or the like is employed.

  The fixed frame 50 </ b> F constitutes the outer peripheral portion of the first parallel spring layer 50.

  The elastic portion 51 includes connection portions 51a and 51b with the fixed frame 50F and joint portions 52a and 52b with the lens unit 60U, and the connection portions 51a and 51b and the joint portions 52a and 52b are plate-like members 50EB. Connected with The first parallel spring layer 50 is bonded to the lens holding portions 62a and 62b of the lens unit 60U at the bonding portions 52a and 52b. Here, the abutting portion 61Ta of the lens unit 60U passes through the hollow portion formed inside the elastic portion 51 and contacts the substantially central portion of the portion where the first movable portion 41a of the actuator layer 40 is installed. Touch. Furthermore, the first parallel spring layer 50 has a shape that does not come into contact with the protrusions 61a and 61b and the contact portions 61Ta and 61Tb of the lens unit 60U. Here, the abutting portion 61Tb of the lens unit 60U passes through the hollow portion formed inside the elastic portion 51 and contacts the substantially central portion of the portion where the second movable portion 41b of the actuator layer 40 is installed. Touch.

  As the lens unit 60U is moved in the + Z direction with respect to the fixed frame 50F, the positions of the connecting portions 51a and 51b and the joint portions 52a and 52b in the Z direction are shifted, and the plate-like member 50EB is bent and deformed (deflection). Deformation) and bends. That is, the first parallel spring layer 50 can be elastically deformed in the optical axis direction (± Z direction) of the optical lens portion 63 by elastic deformation of the plate-like member 50EB, and functions as a spring mechanism.

  Further, one main surface and the other main surface of the fixed frame 50F are configured to be substantially flat, and the one main surface and the other main surface are configured to be substantially parallel. Then, one main surface of the fixed frame 50F is joined to the fixed frame 40F of the adjacent actuator layer 40, and the other main surface of the fixed frame 50F is fixed to the fixed frame 60F of the imaging lens layer 60 (FIG. 9). Joined with.

  By the way, as shown in FIG. 8, the second parallel spring layer 70 has a fixed frame body 50 </ b> F, an elastic portion 51, connection portions 51 a and 51 b, joint portions 52 a and 52 b, as compared with the first parallel spring layer 50. The plate-like member 50EB is changed to a fixed frame 70F, an elastic portion 71, connection portions 71a and 71b, joint portions 72a and 72b, and a plate-like member 70EB each having the same configuration. That is, the second parallel spring layer 70 is also a layer (elastic layer) forming a spring mechanism. However, in the second parallel spring layer 70, one main surface of the fixed frame 70F is joined to the fixed frame 60F (FIG. 9) of the adjacent imaging lens layer 60, and the other main surface of the fixed frame 70F is adjacent. It is joined to the outer periphery of the lid layer 80.

<(2-1-6) Imaging lens layer>
As shown in FIG. 9, the imaging lens layer 60 includes a fixed frame 60F and a lens unit 60U. Examples of the material constituting the imaging lens layer 60 include phenolic resins and acrylic resins.

  The fixed frame 60F constitutes the outer periphery of the imaging lens layer 60, and has a thickness corresponding to the thickness of the lens unit 60U in the Z direction. Specifically, the fixed frame 60F has an annular shape in which the outer edge and the inner edge are each rectangular, and has a hollow portion 60H penetrating in the Z direction. The one main surface and the other main surface of the fixed frame 60F are configured to be substantially flat, and the one main surface and the other main surface are configured to be substantially parallel. Then, one main surface of the fixed frame 60F is joined to the fixed frame 50F of the adjacent first parallel spring layer 50, and the other main surface of the fixed frame 60F is adjacent to the fixed frame of the second parallel spring layer 70. Joined to 70F.

  The lens unit 60U is disposed in the hollow portion 60H and includes an optical lens portion 63, protrusions 61a and 61b, and lens holding portions 62a and 62b.

  The optical lens unit 63 is an optical system that guides light from a subject to the image sensor 11 and has positive lens power.

  The protruding portion 61 a is a portion protruding from the side surface of the optical lens portion 63 in the −X direction. Further, an abutting portion 61Ta (FIG. 3) projecting in the −Z direction is provided in the vicinity of the tip of the protruding portion 61a, and the tip of the corresponding contacting portion 61Ta abuts on the first movable portion 41a.

  The protruding portion 61 b is a portion that protrudes in the + X direction from the side surface of the optical lens portion 63. Further, a contact portion 61Tb (FIG. 3) protruding in the −Z direction is provided in the vicinity of the tip of the protrusion 61b, and the tip of the corresponding contact portion 61Tb contacts the second movable portion 41b.

  In this way, the lens unit 60U that is the moving object comes into contact with the first and second movable parts 41a and 41b by the contact parts 61Ta and 61Tb. Here, in order to stabilize the contact between the contact portion 61Ta and the first movable portion 41a and the contact between the contact portion 61Tb and the second movable portion 41b, the tips of the contact portions 61Ta and 61Tb, respectively. It is preferable that a groove portion in which the first and second movable portions 41a and 41b are disposed is provided in the portion.

  The lens holding portion 62a is a portion protruding from the side surface of the optical lens portion 63 along the diagonal line of the fixed frame 60F. The front end portion of the lens holding portion 62a has a shape protruding in each of the + Z direction and the −Z direction, and one main surface and the other main surface of the front end portion are configured to be substantially flat, and the one main surface and the other The main surface is configured substantially parallel. Then, one main surface of the tip portion of the lens holding portion 62a is bonded to the bonding portion 52a of the first parallel spring layer 50, and the other main surface of the tip portion of the lens holding portion 62a is bonded to the second parallel spring layer 70. It joins with respect to the joining part 72a.

  The lens holding portion 62b is a portion protruding along the diagonal line of the fixed frame 60F from the side surface of the optical lens portion 63 that is substantially opposite to the surface on which the lens holding portion 62a is protruded. The front end portion of the lens holding portion 62b has a shape protruding in each of the + Z direction and the −Z direction, and one main surface and the other main surface of the front end portion are configured to be substantially flat, and the one main surface and the other The main surface is configured substantially parallel. Then, one main surface of the tip portion of the lens holding portion 62b is bonded to the bonding portion 52b of the first parallel spring layer 50, and the other main surface of the tip portion of the lens holding portion 62b is bonded to the second parallel spring layer 70. Are joined to the joint 72b.

  As for the imaging lens layer 60, for example, when the lens holding portions 62a and 62b are joined to the first parallel spring layer 50, the connecting portions 64a and 64b (FIG. 9) drawn by broken lines are femtoseconds. By cutting with a laser or the like, the fixed frame 60F and the lens unit 60U are separated.

<(2-1-7) Lid layer>
As shown in FIG. 10, the lid layer 80 is a plate-like member having a board surface whose outer edge in the XY section is substantially square and substantially parallel to the XY plane. The lid layer 80 is made of a transparent material such as a resin, plays a role of introducing light from the subject into the camera module 500, and seals the inside of the camera module 500 so that the inside of the camera module 500 is sealed. It plays a role to prevent dust and dust from entering. In addition, one main surface of the outer peripheral portion of the lid layer 80 is bonded to the fixed frame 70 </ b> F of the second parallel spring layer 70.

<(2-2) Movement of lens unit>
FIG. 11 is a schematic diagram showing a relative arrangement relationship between the actuator layer 40 and the lens unit 60U. In FIG. 11, the structure which paid its attention to only the actuator layer 40 and the lens unit 60U of the imaging lens layer 60 is shown, and about other layers, such as the 1st and 2nd parallel spring layers 50 and 70, The illustration is omitted.

  As shown in FIG. 11, the actuator layer 40 has a pair of movable parts (specifically, first and second movable parts 41 a and 41 b) with the optical axis of the optical lens part 63 interposed therebetween. As for the movable portion 41a, one end is fixed to the plate-like portion 40Fa, and is constructed so as to reciprocate 1.5 times between the plate-like portion 40Fa and the plate-like portion 40Fc, and the other end is the plate-like portion 40Fc. Fixed to. In addition, the movable portion 41b has one end fixed to the plate-like portion 40Fc, constructed so as to reciprocate 1.5 times between the plate-like portion 40Fc and the plate-like portion 40Fa, and the other end is plate-like. It is fixed to the part 40Fa.

  And in each movable part 41a, 41b, beam part 411a-413a is electrically connected in series by 1st and 2nd connection part C1, C2, and beam part 411b-413b is 4th and 5th connection part C4. Electrically connected in series by C5.

  As shown in FIG. 11, a power supply PW is connected between the electrode portions 40Ea and 40Eb from the outside, and the electrode portion 40Ea and the electrode portion 40Eb are connected according to the opening / closing of the switch SW in the current supply driver 600. A voltage is applied between them. Thereby, each movable part 41a, 41b is heated by generation | occurrence | production of the Joule heat by electricity supply, and deform | transforms so that it may shrink in the extending direction. Moreover, each movable part 41a, 41b is deformed so as to extend in the extending direction by being cooled (air-cooled here) from a state where it is heated by the end of energization. The deformation of each of the movable parts 41a and 41b and the movement of the lens unit 60U will be specifically described below.

  12 and 13 are schematic diagrams for explaining the operation of the lens unit 60U due to the deformation of the SMA film 41. FIG. FIGS. 12 and 13 show a configuration focusing on the lens unit 60U, the SMA film 41, and the fixed frame body 40F.

  As shown in FIGS. 12 and 13, the contact portions 61Ta and 61Tb of the lens unit 60U are in contact with the substantially central portions of the portions where the first and second movable portions 41a and 41b are installed.

  In a state where the first and second movable parts 41a and 41b are not heated by energization (non-driven state), as shown in FIG. 12, the plate-like members 50EB of the first and second parallel spring layers 50 and 70, The force that pushes the lens unit 60U down in the −Z direction is acted on by the elastic force of 70EB becoming flat. At this time, the central portions of the first and second movable portions 41a and 41b are pushed down by the contact portions 61Ta and 61Tb, and the first and second movable portions 41a and 41b are bent. Accordingly, the actuator layer 40 is precharged by the first and second parallel spring layers 50 and 70.

  Further, when the first and second movable parts 41a, 41b are shifted from the non-driven state to a state where the first and second movable parts 41a, 41b are heated by energization (drive state), as shown in FIG. 41b is deformed in the direction of contraction from the bent state to a flat shape. That is, the first and second movable parts 41a and 41b are deformed so as to reduce the amount of bending. At this time, a force that pushes up the lens unit 60U by the first and second movable portions 41a and 41b against the elastic force of the plate-like members 50EB and 70EB is applied, and the lens unit 60U moves in the + Z direction.

  Further, when the first and second movable parts 41a and 41b are shifted from the driving state to a state where the first and second movable parts 41a and 41b are not heated by energization (non-driving state), the position of the lens unit 60U is the original position shown in FIG. Return to the initial position.

Here, in FIG. 13, the shapes of the first and second movable parts 41a and 41b shown in FIG. 12 are indicated by thick broken lines. If the central portion of the first and second movable portions 41a and 41b is pushed down in the −Z direction by the distance δ ₀ in the non-driven state, the lens along the optical axis of the optical lens portion 63 in the driven state. The unit 60U can be moved in the + Z direction within the range up to the distance δ ₀ with reference to the initial position.

  As described above, in the actuator layer 40, the beam portions 411a to 413a are electrically connected in series by the first and second connection portions C1 and C2, and the beam portions 411b to 413b are connected to the fourth and fifth connection portions C4 and C4. Electrically connected in series by C5. Therefore, the total value of the cross-sectional areas of the beam portions 411a to 413a related to the plane perpendicular to the extending direction of the beam portions 411a to 413a, that is, the cross-sectional area of the portion where the first movable portion 41a is installed is While being kept large to some extent, the total value of the cross-sectional areas of the beam portions 411b to 413b related to the plane perpendicular to the extending direction of the beam portions 411b to 413b, that is, the portion where the second movable portion 41b is installed The arrangement path of each movable part 41a, 41b is extended while the cross-sectional area is kept large to some extent. As a result, the electrical resistance value between the one end and the other end of each movable portion 41a, 41b is increased.

  By the way, when the mobile phone 100 is dropped on the ground or when the mobile phone 100 is shaken violently, an inertial force is generated in the lens unit 60U and instantaneously applied to the first and second movable parts 41a and 41b. It is assumed that a large force is applied to

  With respect to such a problem, in the present embodiment, as described above, the cross-sectional area of the portion where the first and second movable parts 41a and 41b are installed is kept large to some extent. For this reason, the capacity | capacitance (henceforth "allowable force") which the 1st and 2nd movable parts 41a and 41b can endure the load of an impact or external force increases. Further, the maximum force (maximum possible output) that the first and second movable parts 41a, 41b can apply to the lens unit 60U is also increased. Furthermore, if the voltage applied between the electrode portions 40Ea and 40Eb is the same due to an increase in the electrical resistance value in the SMA film 41, the current consumption is reduced and the power consumption is suppressed. Then, by appropriately adjusting the cross-sectional area of the part where the first and second movable parts 41a and 41b are installed and the number of beam parts electrically connected in series, the electric resistance and the allowable force are adjusted. It can be set appropriately. Accordingly, the degree of freedom in designing the SMA layer 41 is increased.

  14 and 15 are schematic diagrams for explaining the functions of the first and second parallel spring layers 50 and 70. FIG. 14 and 15 are schematic views of the lens unit 60U and the elastic portions 51 and 71 as viewed from the side. As shown in FIGS. 14 and 15, the elastic units 51 and 71 are joined to the lens unit 60U at the joints 52a, 52b, 72a, and 72b, respectively, thereby sandwiching the lens unit 60U. FIG. 14 shows a state where the elastic portions 51 and 71 are hardly deformed (initial state), and FIG. 15 shows a state where the elastic portions 51 and 71 are deformed to some extent (deformed state). Yes.

  As described above, the elastic portions 51 and 71 have the same configuration, and are similarly fixed to the fixed frame bodies 50F and 70F at two locations (the connection portions 51a and 51b and the connection portions 71a and 71b). Is done. Similarly, the elastic portions 51 and 71 are joined to the lens unit 60U at two locations (joining portions 52a and 52b and joining portions 72a and 72b). Then, due to the deformation of the first and second movable portions 41a and 41b, as shown in FIG. 15, when the lens unit 60U is pushed up in the + Z direction, the elastic portions 51 and 71 perform substantially the same deformation. For this reason, the optical lens unit 63 included in the lens unit 60U moves in the vertical direction (here, the direction along the Z axis) without the optical axis being inclined. That is, the distance between the optical lens unit 63 and the image sensor 11 is changed without shifting the direction of the optical axis of the optical lens unit 63. As a result, the distance between the image sensor 11 and the optical lens unit 63 is changed, and autofocus control for performing focus adjustment is executed.

<(2-3) Autofocus control in camera module>
The autofocus control in the camera module 500 is realized by the current supply driver 600, the electric resistance detection unit 700, the contrast detection unit 800, and the focus control unit 310 shown in FIG.

  Specifically, the electrical resistance detection unit 700 detects the electrical resistance of the SMA film 41 and outputs a signal indicating the electrical resistance to the focusing control unit 310. The focusing control unit 310 detects deformation of the SMA film 41 (specifically, displacement of the central portions of the first and second movable parts 41a and 41b) based on the electrical resistance of the SMA film 41. That is, the electrical resistance detection unit 700 and the focus control unit 310 detect the electrical resistances related to the first and second movable parts 41a and 41b, so that the displacements related to the first and second movable parts 41a and 41b are changed. Be recognized. Here, the displacement of the central part of the first and second movable parts 41a and 41b becomes the displacement of the lens unit 60U.

  About the detection of the displacement of the center part of the 1st and 2nd movable parts 41a and 41b, the relationship between the shape and electric resistance in the SMA film | membrane 41 (specifically 1st and 2nd movable parts 41a and 41b) is unambiguous. Is determined and used. Then, the focus control unit 310 controls the supply of current to the SMA film 41 via the current supply driver 600 while detecting the displacement of the central portions of the first and second movable units 41a and 41b. The amount of deformation of the first and second movable parts 41a and 41b, that is, the displacement of the central part of the first and second movable parts 41a and 41b is controlled. At this time, when the abutting portions 61Ta and 61Tb are pushed up by the central portion, the lens unit 60U is moved in the + Z direction, so that the separation distance between the optical lens portion 63 and the image sensor 11 is changed, and the focal position is changed. Is changed.

  Further, the contrast detection unit 800 detects the contrast of the image signal obtained by the image sensor 11. For example, a numerical value obtained by accumulating differences in gradation values between adjacent pixels for the entire image is detected as an evaluation value indicating contrast. A signal indicating the evaluation value indicating the contrast is output to the focus control unit 310.

  When autofocus control is performed, first, the separation distance between the lens unit 60U and the image sensor 11 is sequentially set to a preset multi-step separation distance under the control of the focusing control unit 310, and each separation distance is set. An image signal is acquired by the imaging device 11 in a state where the lens unit 60U and the imaging device 11 are set to the distance. In other words, the extension position of the lens unit 60U in the + Z direction is set to a preset multi-stage position, and an image signal is output by the imaging device 11 at the time when the lens unit 60U is disposed at each extension position. To be acquired. At this time, the focus control unit 310 controls the supply of current to the SMA film 41 via the current supply driver 600 while monitoring the electrical resistance of the SMA film 41 detected by the electrical resistance detection unit 700. Thus, the feeding position of the lens unit 60U is changed.

  Next, the focus control unit 310 detects a feeding position at which the evaluation value indicating the contrast is maximum based on the evaluation value indicating the contrast detected for each feeding position by the contrast detection unit 800. The state where the lens unit 60U is disposed at the extended position where the evaluation value indicating the contrast is maximum corresponds to the state where the subject is in focus. Then, under the control of the focus control unit 310, the lens unit 60U is moved to the extended position where the evaluation value indicating the contrast is maximized, thereby achieving focusing on the subject in the camera module 500. That is, autofocus control is realized.

  Here, in the SMA film 41, since the beam portions 411a to 413a and the beam portions 411b to 413b are electrically connected in series by the first to fifth connection portions C1 to C5, the electric resistance value of the SMA film 41 is increased. . For this reason, the amount of change in the electrical resistance value of the SMA film 41 corresponding to the displacement of the first and second movable parts 41a and 41b increases. As a result, the influence of disturbance in the detection of the change in the electrical resistance value is reduced, and the detection sensitivity of the displacement of the lens unit 60U is increased, so that the accuracy of autofocus control is improved.

<(3) Camera module manufacturing process>
FIG. 16 is a flowchart illustrating the procedure of the manufacturing process of the camera module 500. As shown in FIG. 16, (Process A) preparation of a plurality of sheets (Step S1), (Process B) joining of a plurality of sheets (Step S2), and (Process C) dicing (Step S3) are sequentially performed. As a result, the camera module 500 is manufactured. Hereinafter, each step will be described.

<(3-1) Preparation of a plurality of sheets (Process A)>
As shown in FIG. 17, the imaging element layer sheet U10, the imaging element holding layer sheet U20, the spacer layer sheet U30, the actuator layer sheet U40, the first parallel spring layer sheet U50, the imaging lens layer sheet U60, and the second parallel spring layer. A sheet U70 and a lid layer sheet U80 are prepared. Here, an example in which each sheet has a disk shape will be described.

  The imaging element layer sheet U10 is a sheet in which a large number of chips corresponding to the imaging element layer 10 are formed in a matrix-like predetermined arrangement. The imaging element layer sheet U10 is manufactured, for example, by forming the imaging element 11 and various circuits on a disk-shaped silicon substrate.

The imaging element holding layer sheet U20 is a sheet in which a large number of chips corresponding to the imaging element holding layer 20 are formed in a matrix-like predetermined arrangement. The image pickup element holding layer sheet U20, for example, with respect to the material disc-like wafer which is formed by a resin or the like, the opening 20H and the through hole CV _2a by embossing or the like, CV _2b is formed, the through hole CV _2a , CV _2b is manufactured by being filled with a conductive material by metal plating or the like.

The spacer layer sheet U30 is a sheet in which a large number of chips corresponding to the spacer layer 30 are formed in a matrix-like predetermined arrangement. The spacer layer sheet U30, for example, with respect to the material disc-like wafer which is formed by a resin or the like, the hollow portion and the through-hole CV _3a, CV _3b is formed by embossing or the like, through hole CV _3a, CV _{The 3b} is manufactured by being filled with a conductive material by metal plating or the like.

  The actuator layer sheet U40 is a sheet in which a large number of chips corresponding to the actuator layer 40 are formed in a matrix-like predetermined arrangement. The actuator layer sheet U40 is manufactured, for example, by sequentially performing the following steps (I) to (VII).

(I) A silicon substrate is prepared. (II) Through holes CV _4a and CV _4b are formed in the silicon substrate by etching or the like using a photolithography technique. The through holes CV _4a and CV _4b may be formed by etching such as DRIE (Deep Reactive Ion Etching). (III) The through holes CV _4a and CV _4b are filled with a conductive material by metal plating or the like. (IV) The electrode portions 40Ea and 40Eb are formed at positions covering the through holes CV _4a and CV _4b of the silicon substrate by coating or vapor deposition using a printing technique. (V) A thin film of shape memory alloy is formed on the silicon substrate by sputtering or the like. (VI) The shape memory alloy thin film is subjected to a heat treatment (memory heat treatment) for memorizing the shape so that it shrinks during high temperature heating. Here, the thin film of shape memory alloy memorizes a planar shape. (VII) The SMA film 41 having the first and second movable parts 41a and 41b and the third connection part C3 is formed on the thin film of shape memory alloy by etching or the like using a photolithography technique. (VIII) The hollow portion 40H is formed by subjecting the silicon substrate to selective etching using hydrofluoric acid which is a mixed liquid of hydrofluoric acid and nitric acid. At this time, the first and second movable parts 41a and 41b are installed so as to straddle the hollow part 40H.

  The first parallel spring layer sheet U50 is a sheet in which a number of chips corresponding to the first parallel spring layer 50 are formed in a matrix-like predetermined arrangement. For example, the first parallel spring layer sheet U50 is formed by applying a resist in the shape of a parallel spring on a metal material by photolithography on a disk-shaped wafer formed of a metal material such as stainless steel or a material such as phosphor bronze. A pattern of parallel springs is formed by performing wet etching by immersing in an iron chloride-based etching solution.

  The imaging lens layer sheet U60 is a sheet in which a large number of chips corresponding to the imaging lens layer 60 are formed in a matrix-like predetermined arrangement. However, in the imaging lens layer sheet U60, in each chip, the fixed frame 60F and the protruding portions 61a and 61b are connected by the connecting portions 64a and 64b. The imaging lens layer sheet U60 is manufactured, for example, by resin molding.

  The second parallel spring layer sheet U70 is a sheet in which a number of chips corresponding to the second parallel spring layer 70 are formed in a matrix-like predetermined arrangement. The second parallel spring layer sheet U70 is manufactured in the same process as the first parallel spring layer sheet U50.

  The lid layer sheet U80 is a sheet in which a large number of chips corresponding to the lid layer 80 are formed in a matrix-like predetermined arrangement. The lid layer sheet U80 is manufactured, for example, by resin molding. In addition, when the shape of the cover layer 80 may be a simple flat plate, the cover layer sheet U80 may be flat glass.

  The eight sheets U10 to U80 prepared in step A are provided with marks (alignment marks) for alignment in the sheet joining step at substantially the same position. Examples of the alignment mark include a cross mark, and the like, and are preferably provided at two or more positions in the vicinity of the outer peripheral portion of the upper surface of each of the sheets U10 to U80.

<(3-2) Joining of multiple sheets (Process B)>
As shown in FIG. 17, the eight sheets U10 to U80 prepared in step A are sequentially stacked and joined.

  First, each chip of the imaging element layer sheet U10, the imaging element holding layer sheet U20, the spacer layer sheet U30, the actuator layer sheet U40, the first parallel spring layer sheet U50, and the imaging lens layer sheet U60 is laminated immediately above. Thus, alignment (alignment) is performed with the sheet shape.

Specifically, first, the imaging element layer sheet U10 and the imaging element holding layer sheet U20 are set in a known aligner apparatus, and alignment using a previously formed alignment mark is performed. At this time, a so-called epoxy resin adhesive or ultraviolet curable adhesive is applied in advance to the surface (joint surface) to which the image sensor layer sheet U10 and the image sensor holding layer sheet U20 are joined. Sheets U10 and U20 are joined. Alternatively, a method may be used in which the joining surfaces are activated by irradiating the joining surfaces with O ₂ plasma and both sheets U10 and U20 are directly joined.

  Subsequently, the spacer layer sheet U30 is joined on the imaging element holding layer sheet U20 by the same alignment and joining method as described above, and then the actuator layer sheet U40 is joined on the spacer layer sheet U30. The first parallel spring layer sheet U50 is joined onto the actuator layer sheet U40, and the imaging lens layer sheet U60 is joined onto the first parallel spring layer sheet U50.

  At this time, each lens holding portion 62a of the imaging lens layer sheet U60 is joined to each joining portion 52a of the first parallel spring layer sheet U50, and each contact portion 61Ta of the imaging lens layer sheet U60 is the first movable. It abuts against the substantially central portion of the portion 41a. In addition, each lens holding portion 62b of the imaging lens layer sheet U60 is joined to each joining portion 52b of the first parallel spring layer sheet U50, and each contact portion 61Tb of the imaging lens layer sheet U60 is a second movable portion. It abuts against the substantially central portion of 41b.

In addition, here, the three sheets U20 to U40 are joined, so that the conductive materials filled in the through holes CV _{2a to} CV _4a are electrically connected to each other, thereby forming the through holes CVa. A through wiring is formed. Further, the conductive material filled in the through holes CV _{2b to} CV _4b is electrically connected to each other, thereby forming a through wiring formed by the through hole CVb.

  Further, in a state where the imaging lens layer sheet U60 is bonded onto the first parallel spring layer sheet U50, the connecting portions 64a and 64b that connect the fixed frame body 60F and the projecting portions 61a and 61b are cut, thereby being fixed. The frame 60F and the protrusions 61a and 61b are separated.

  Next, the second parallel spring layer sheet U70 and the lid layer sheet U80 are laminated and joined in this order from the bottom to the upper surface of the laminate formed by laminating the six sheets U10 to U60. About the alignment and the joining method, it is the same as that of the method which concerns on the sheet | seats U10-U60 mentioned above, and each chip | tip of the sheet | seats U10-U80 is each laminated | stacked immediately on top.

  At this time, each lens holding part 62a of the imaging lens layer sheet U60 is joined to each joining part 72a of the second parallel spring layer sheet U70, and each lens holding part 62b of the imaging lens layer sheet U60 is joined to the first lens holding part 62a. The two parallel spring layer sheets U70 are joined to each joint 72b.

<(3-3) Dicing (Process C)>
The laminated member formed by laminating the eight sheets U10 to U80 is separated for each chip by the dicing apparatus, and a large number of camera modules 500 in which the eight layers 10 to 80 are laminated are generated. That is, the camera module 500 is completed.

  As described above, in the mobile phone 100 equipped with the camera module 500 according to the embodiment of the present invention, the actuator layer 40 has a section related to the plane perpendicular to the extending direction of the first and second movable parts 41a and 41b. The electrical resistance value in the first and second movable parts 41a and 41b can be increased by lengthening the arrangement path of the first and second movable parts 41a and 41b while maintaining the area. . For this reason, the actuator layer 40 that can withstand a load of an impact or an external force while suppressing power consumption is realized.

  The first movable portion 41a is electrically connected in series with the plurality of beam portions 411a to 413a, and the second movable portion 41b is electrically connected in series with the plurality of beam portions 411b to 413b. Thereby, the arrangement | positioning path | route of 1st and 2nd movable part 41a, 41b becomes long. For this reason, the electrical resistance values of the first and second movable parts 41a and 41b increase, so that the displacements related to the first and second movable parts 41a and 41b can be accurately recognized regardless of the influence of disturbance. can do.

<(4) 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 above-described embodiment, both ends of each of the beam portions 411a to 413a and 411b to 413b are fixed to the fixed frame body 40F as a fixing member. For example, one end of each beam portion may be fixed to a fixed member, and the other end of each beam portion may be fixed to a moving member that moves relative to the fixed member. That is, at least one of the members to which the end portions of the beam portions are fixed may be a fixing member. Hereinafter, a specific embodiment having a configuration in which one end portion of each beam portion is fixed to the moving member will be described.

  FIG. 18 is a schematic diagram according to a configuration example of an actuator layer 40A according to a modification. In this modification, an actuator layer 40A is employed instead of the actuator layer 40, the first parallel spring layer 50, the imaging lens layer 60, and the second parallel spring layer 70 that constitute the camera module 500 according to the above-described embodiment. Thus, description will be made assuming that the mobile phone 100A having the first housing 200A on which the camera module 500A is mounted is configured.

  As shown in FIG. 18, the actuator layer 40A includes a fixed frame 40FA as a fixed member, a lens holder 63HD as a moving member, electrode portions 40Ea and 40Eb, and an SMA film 41A as a movable portion.

  The fixed frame body 40FA is formed of, for example, resin or the like, and has a hollow portion 40HA that penetrates in the center direction in the Z direction. The hollow portion 40HA has a substantially circular cross section.

  The lens holder 63HD is formed of, for example, resin or the like, and is an annular member whose outer edge and inner edge are substantially circular, and is disposed in the hollow portion 40HA. That is, the fixed frame body 40FA is provided around the lens holder 63HD. Although not shown in FIG. 18, a bias spring BA (FIGS. 19 and 20) is provided on the other main surface side of the lens holder 63HD, and the bias spring BA is located with respect to the lens holder 63HD. -Applying a force to push down in the Z direction. In addition, by attaching the optical lens unit 63 as a moving object to the lens holder 63HD, a driving device that moves the optical lens unit 63 by the actuator layer 40A is configured.

  The electrode portions 40Ea and 40Eb are portions on the other main surface of the fixed frame 40FA, and are portions for applying a voltage to one end and the other end of the SMA film 41A. Here, the position of the through wiring is appropriately set according to the arrangement of the electrode portions 40Ea and 40Eb.

  The SMA film 41A is configured using a shape memory alloy, and includes eight beam portions 411A to 418A and nine first to ninth connection portions CA1 to CA9. Each of the beam portions 411A to 418A is installed between the fixed frame body 40FA and the lens holder 63HD, and holds the lens holder 63HD so as to be movable in the direction along the Z axis. Here, the installation positions of the eight beam portions 411A to 418A are substantially equidistant places around the lens holder 63HD. With such an installation form, the lens holder 63HD is held in a well-balanced manner, and the optical axis of the optical lens unit 63 is prevented from being inclined.

  Here, the first, third, fifth, seventh, and ninth connecting portions CA1, CA3, CA5, CA7, CA9 are arranged on the other main surface of the fixed frame 40FA, and the second, fourth, The sixth and eighth connection portions CA2, CA4, CA6, CA8 are disposed on the other main surface of the lens holder 63HD. In addition, about 1-9th connection part CA1-CA9, you may be comprised with the raw material which has the other electroconductivity which is not a shape memory alloy.

  Also, one end of the first connection portion CA1 is electrically connected to the electrode portion 40Ea, and the other end of the first connection portion CA1 is electrically connected to one end of the beam portion 411A. . The other end portion of the beam portion 411A is electrically connected to one end portion of the second connection portion CA2, and the other end portion of the second connection portion CA2 is electrically connected to one end portion of the beam portion 412A. Is done. The other end portion of the beam portion 412A is electrically connected to one end portion of the third connection portion CA3, and the other end portion of the third connection portion CA3 is electrically connected to one end portion of the beam portion 413A. Is done. The other end portion of the beam portion 413A is electrically connected to one end portion of the fourth connection portion CA4, and the other end portion of the fourth connection portion CA4 is electrically connected to one end portion of the beam portion 414A. Is done. The other end portion of the beam portion 414A is electrically connected to one end portion of the fifth connection portion CA5, and the other end portion of the fifth connection portion CA5 is electrically connected to one end portion of the beam portion 415A. Is done.

  Furthermore, the other end portion of the beam portion 415A is electrically connected to one end portion of the sixth connection portion CA6, and the other end portion of the sixth connection portion CA6 is electrically connected to one end portion of the beam portion 416A. Connected to. The other end portion of the beam portion 416A is electrically connected to one end portion of the seventh connection portion CA7, and the other end portion of the seventh connection portion CA7 is electrically connected to one end portion of the beam portion 417A. Is done. The other end portion of the beam portion 417A is electrically connected to one end portion of the eighth connection portion CA8, and the other end portion of the eighth connection portion CA8 is electrically connected to one end portion of the beam portion 418A. Is done. The other end portion of the beam portion 418A is electrically connected to one end portion of the ninth connection portion CA9, and the other end portion of the ninth connection portion CA9 is electrically connected to the electrode portion 40Eb.

  As described above, the SMA film 41A is moved between the fixed frame body 40FA and the lens holder 63HD so that the eight beam portions 411A to 418A reciprocate between the fixed frame body 40FA and the lens holder 63HD four times. It will be erected.

  And in SMA film | membrane 41A, 1st connection part CA1, beam part 411A, 2nd connection part CA2, beam part 412A, 3rd connection part CA3, beam part 413A, 4th connection part CA4, beam part 414A, 5th connection Part CA5, beam part 415A, sixth connection part CA6, beam part 416A, seventh connection part CA7, beam part 417A, eighth connection part CA8, beam part 418A, and ninth connection part CA9 are electrically connected in this order. Connected in series. Therefore, when a voltage is applied between the electrode part 40Ea and the electrode part 40Eb, a current flows through the SMA film 41A. At this time, the SMA film 41A generates heat due to Joule heat generated in response to energization and deforms in response to the heat generation.

  Further, since the SMA film 41A formed integrally is connected to the fixed frame body 40FA and the lens holder 63HD in each of the connection portions, the area of the entire connection portion is increased, so that the impact and external force are increased. The ability to withstand the load will increase.

  19 and 20 are schematic diagrams for explaining the operation of the optical lens unit 63 due to the deformation of the SMA film 41A. 19 and 20 show a configuration in which attention is paid to the optical lens portion 63, the SMA film 41A, and the fixed frame body 40FA.

  In a state where the SMA film 41A is not heated by energization (non-driven state), as shown in FIG. 19, a force that pushes down the lens holder 63HD in the −Z direction acts by the bias spring BA. At this time, the lens holder 63HD is pushed down and the SMA film 41A is bent. Therefore, the actuator layer 40A is precharged by the bias spring BA.

  Further, when the SMA film 41A is shifted from the non-driving state to a state where the SMA film 41A is heated by energization (driving state), as shown in FIG. 20, the beam portions 411A to 418A of the SMA film 41A are bent. It is deformed in the direction that it is shrunk and becomes flat. That is, the SMA film 41A is deformed so as to decrease the amount of bending. At this time, a force to push up the lens holder 63HD by the SMA film 41A against the elastic force of the bias spring BA is applied, and the lens holder 63HD to which the optical lens unit 63 is attached moves in the + Z direction.

  Further, when the SMA film 41A is not heated by energization (non-driving state) from the driving state, the position of the lens holder 63HD to which the optical lens unit 63 is attached is the original position shown in FIG. Return to (initial position).

Here, in the non-driven state, if the lens holder 63HD is pushed down the distance δ _{0 in the} −Z direction from the position of the lens holder 63HD when the SMA film 41A is substantially flat, the light of the optical lens unit 63 It is possible to move the lens holder 63HD, to which the optical lens unit 63 is attached, along the axis in the + Z direction within the range of the distance δ ₀ with reference to the initial position.

  As described above, in the actuator layer 40A, the eight beam portions 411A to 418A are electrically connected in series by the first to ninth connection portions CA1 to CA9. For this reason, the total value of the cross-sectional areas of the beam portions 411A to 418A related to the plane perpendicular to the extending direction of the beam portions 411A to 418A, that is, the cross-sectional area of the installation portion of the SMA film 41A is kept large to some extent. The installation path of the erection part in the SMA film 41A is extended while being sag, and the electrical resistance value between the one end and the other end of the SMA film 41A is increased. Therefore, similarly to the above-described embodiment, an actuator layer 40A that can withstand a load of impact or external force while suppressing power consumption is realized.

  The lens holder 63HD is supported by the SMA film 41A. For this reason, the actuator layer 40A can be easily manufactured by simplifying the configuration and manufacturing process of the actuator layer 40A.

  In this modification, the bias spring BA is provided. However, the bias spring BA is not limited thereto. For example, as in the above-described embodiment, the first and second parallel spring layers that sandwich the lens holder 63HD may be provided. good. In the present modification, the SMA film 41A has the eight beam portions 411A to 418A, but is not limited thereto, and may be configured to have, for example, three or more beam portions. Furthermore, in this modification, the optical lens unit 63 as a moving object is attached to the lens holder 63HD, but the present invention is not limited to this. For example, the SMA film may be formed so that a beam portion is provided between the fixed frame body 40FA and the optical lens portion 63.

  In the above embodiment, each of the movable portions 41a and 41b is installed so as to make one and a half reciprocations between the plate-like portion 40Fa and the plate-like portion 40Fc. As long as it is constructed like this.

  In the above embodiment, the lens unit 60U, which is a moving object, is in direct contact with the first and second movable parts 41a and 41b. However, the present invention is not limited to this. For example, the shape of the first parallel spring layer 50 is changed, and the lens unit 60U is brought into contact with the first and second movable portions 41a and 41b via another member such as the first parallel spring layer 50. Also good.

  In the above-described embodiment and the above-described modification, the layered actuator layers 40 and 40A are employed. However, the present invention is not limited to this. For example, an actuator having a certain thickness may be used.

  In addition, in the above-described embodiment and the above-described modification, the moving object is the optical lens unit 63, but is not limited thereto. For example, other members such as an image sensor may be used as the moving object. For example, the optical lens unit corresponding to the optical system that guides light from the subject to the image sensor is fixed, and the image sensor layer is formed by the same configuration as the configuration for moving the optical lens unit 63 in the above-described embodiment or modification. It may be moved in the direction.

  FIG. 21 is a diagram illustrating a conceptual diagram of an aspect in which the optical lens unit 63B is fixed and the imaging element layer 10B is moved back and forth in a direction along the optical axis Ax of the optical lens unit 63B. In FIG. 21, an actuator AC that moves the imaging element layer 10B back and forth along the optical axis Ax is depicted. In such a configuration, the image sensor layer 10B is moved back and forth along the optical axis Ax in accordance with the operation of the actuator AC, and the distance between the optical lens unit 63B and the image sensor layer 10B is changed. Focus control is realized. As described above, when at least one of the image sensor and the optical system is moved in accordance with the deformation of the SMA films 41 and 41A, 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 configured using SMA and a driving device in which a moving object is moved in accordance with deformation of the SMA.

  Of course, it is needless to say that all or a part of the configurations of the above-described embodiment and various modifications can be combined as appropriate within a consistent range.

DESCRIPTION OF SYMBOLS 10, 10B Image pick-up element layer 11 Image pick-up element 40, 40A Actuator layer 40F, 40FA Fixed frame body 40Fa-40Fd Plate-shaped part 41A Shape alloy film (SMA) film | membrane 41a 1st movable part 41b 2nd movable part 50 1st parallel spring layer 60 Image pickup lens layer 60U Lens unit 61a, 61b Projection part 61Ta, 61Tb Contact part 62a, 62b Lens holding part 63, 63B Optical lens part 63HD Lens holder 70 Second parallel spring layer 100, 100A Mobile phone 310 Focus control part 411a 413a, 411b to 413b, 411A to 418A Beam section 500, 500A Camera module 600 Current supply driver 700 Electric resistance detection section 800 Contrast detection section C1 to C5, CA1 to CA9 Connection section

Claims (8)

A movable part that is configured using a film-shaped shape memory alloy and generates heat in response to energization and deforms in response to the heat generation;
First and second members to which the movable part is fixed;
Recognizing means for recognizing a displacement associated with the movable part by detecting an electrical resistance associated with the movable part ;
With
The first member is
It is included in a plate-like fixed frame body having two main surfaces that are substantially parallel to each other and substantially flat,
A part of the shape memory alloy of the movable part is
It is fixed to the first member by being formed in a film shape along the main surface of the fixed frame on the fixed frame,
The movable part is
Wherein the first member between said second member at least once for reciprocal actuator characterized by Tei Rukoto is bridged between the second member and the first member. The actuator according to claim 1,
The first and second members are
Each included in the fixed frame,
The fixed frame is
A hollow portion penetrating the two main surfaces;
The movable part is
Actuator characterized that you have been bridged so as to cross the hollow portion. An actuator according to claim 2 ;
A moving object that abuts against the movable part or via a separate member;
Drive apparatus according to claim Rukoto equipped with. The actuator according to claim 1 ,
The actuator, wherein the second member is a moving member that moves relative to the first member . An actuator according to claim 4,
The first member is
A hollow portion is provided around the second member;
The movable part is
Actuator according to claim erection is Rukoto to straddle the hollow portion between the first member and the second member in a substantially equally spaced locations around said second member. An actuator according to claim 4 or 5 , and
A moving object fixed to the second member;
Drive apparatus according to claim Rukoto equipped with. An actuator according to any one of claims 2, 4 and 5 ;
An image sensor;
An optical system for guiding light from a subject to the image sensor;
With
An imaging device at least one of the imaging element and the optical system, characterized in that it is moved by the deformation of the movable portion. The imaging apparatus according to claim 7 ,
An image pickup device holding member for holding the image pickup device; and an annular member having a hollow portion in which the optical system is arranged,
The imaging element holding member and the annular member are plate-like members each having two main surfaces that are substantially parallel to each other and substantially flat,
Imaging device and the imaging element holding member and the annular member and the actuator is characterized that you have been laminated.

Images