WO2011040250A1

WO2011040250A1 - Actuator, drive device, and camera module

Info

Publication number: WO2011040250A1
Application number: PCT/JP2010/066036
Authority: WO
Inventors: 泰啓本多; 隆松尾
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2009-09-29
Filing date: 2010-09-16
Publication date: 2011-04-07
Also published as: JP5056984B2; JPWO2011040250A1

Abstract

Disclosed is a technology of accurately controlling, with a simple configuration, displacement generated in an actuator, irrespective of variance of the thickness and the qualities of thin films for controlling displacement, said variance being generated among actuators. The actuator is provided with: a reference section; and a movable section, which has a fixed section fixed to the reference section, and which has a displacement section that is displaced due to deformation that corresponds to energy applied thereto. In the actuator, the movable section has a deforming film, which is configured using a conductor material and/or a semiconductor material, and deforms corresponding to deformation of the movable section, and the reference section has a reference film that is formed using the material same as the material for the deforming film, in the same step wherein the deforming film is formed.

Description

Actuator, drive device, and camera module

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

In recent years, many small camera units (micro camera units) have been produced for the purpose of mounting on small electronic devices such as mobile phones.

This micro camera unit (MCU) has a very high demand for miniaturization and price reduction. On the other hand, with respect to the MCU, as the number of pixels increases (higher pixels), it is becoming essential to have an autofocus (AF) function in order to satisfy image quality and user convenience.

Therefore, in response to the demand for reduction in size and price for MCU, 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 are arranged through a resin layer. A technique has been proposed in which a laminated member is formed by pasting, and the laminated member is diced to complete individual camera modules (for example, Patent Document 1). According to this technology, it is possible to cut out hundreds of camera modules from a single wafer-like laminated member, and the matching with the microfabrication process is good. This is considered to contribute greatly to cost reduction.

Japanese Patent Laid-Open No. 2007-12995

However, in the technique of Patent Document 1, it is difficult to arrange an actuator for moving an imaging lens such as a voice coil motor for realizing an AF function in order to stack wafer-like members. In addition, in order to perform AF control for moving the imaging lens, it is necessary to detect the displacement of the imaging lens. For example, if a conventional technique for detecting displacement using an encoder, a photosensor, or the like is applied, the MCU Increase in size and cost.

By the way, as an actuator applicable to a small camera module formed in a wafer state, for example, at least one of a piezoelectric element (PZT), a shape memory alloy (SMA), and a bimetal (Bi-metallic layer) is used. A thin-film actuator having a unimorph shape including the above configuration is conceivable.

Then, by providing a thin film mainly made of a conductive material at the deformed portion and detecting a change in electrical resistance accompanying the deformation in the thin film, the imaging lens is not increased in size and cost. It is conceivable to detect the displacement. In addition, as such a thin film, the structure used for a general strain gauge etc. can be considered. With respect to the strain gauge, in order to suppress variation between elements, a metal stay or the like is precisely processed to ensure detection accuracy.

However, when a thin film is formed on a part of the actuator, variations in the thickness and quality of the thin film occur between production lots due to changes in various conditions in the manufacturing process. For this reason, when the electric resistance in the thin film varies, the displacement of the imaging lens cannot be detected with high accuracy, and as a result, the displacement amount of the imaging lens cannot be controlled with high accuracy. Such a problem is common to various actuators for moving a moving object, and a drive device and a camera module in which the actuator is mounted.

The present invention has been made in view of the above problems, and an actuator capable of accurately controlling displacement generated in an actuator with a simple configuration regardless of variations in the thickness and film quality of the displacement control thin film generated between the actuators. It is an object of the present invention to provide a driving device and a camera module on which the actuator is mounted.

In order to solve the above problem, an actuator according to a first aspect includes a reference portion and a fixed portion fixed to the reference portion, and a displacement portion that is displaced by deformation according to the application of energy. A movable part. In the actuator, the movable portion includes a deformation film that is configured using at least one material of a conductor and a semiconductor and is deformed along with the deformation of the movable portion, and the reference portion is the deformation The reference film is formed in the same process using the same material as the film.

An actuator according to a second aspect is the actuator according to the first aspect, wherein the first electrically connected to the deformation film and electrically connectable to an element outside the actuator. A terminal portion and a second terminal portion electrically connected to the reference film and electrically connectable to an external element of the actuator, wherein the first and second element portions are , Provided in the reference portion.

The actuator according to the third aspect is the actuator according to the first aspect, wherein the reference film and the deformation film are formed simultaneously in the same step.

The actuator according to the fourth aspect is the actuator according to any one of the first to third aspects, wherein the reference film and the deformation film have the same thickness and the same crystal state.

An actuator according to a fifth aspect is the actuator according to any one of the first to fourth aspects, wherein the reference film and the deformation film are formed as an integral film formed using the same material. included.

The actuator according to a sixth aspect is the actuator according to any one of the first to fifth aspects, wherein the movable part includes a base part and a shape memory part configured using a shape memory material. And deforming according to the deformation of the shape memory unit according to the temperature change.

An actuator according to a seventh aspect is the actuator according to any one of the first to sixth aspects, wherein the deformable film generates a driving force in response to application of energy, whereby the movable part is Deform.

The actuator according to an eighth aspect is the actuator according to any one of the first to fifth aspects, wherein the movable portion includes first and second layers having different thermal expansion coefficients and the deformation film. It has a structure in which a plurality of layers including are laminated and is deformed according to a temperature change.

The actuator according to the ninth aspect is the actuator according to any one of the first to eighth aspects, and the deformation film includes a heater portion that generates heat in response to energization.

The drive device according to the tenth aspect is determined in accordance with the impedance relation between the actuator according to any one of the first to ninth aspects, the reference film and the deformation film, and the impedance relation. And a control unit that controls a supply amount of the energy applied to the movable unit according to at least one of the electrical information.

The drive device according to the eleventh aspect is the drive device according to the tenth aspect, wherein the impedance relationship includes an impedance ratio between the reference film and the deformation film.

A drive device according to a twelfth aspect is the drive device according to the eleventh aspect, wherein a target value of a ratio of electrical resistance between the reference film and the deformation film with respect to each displacement amount of the displacement portion. Includes a target value storage unit that stores target value information associated with each of the target value information. In the driving device, the control unit supplies the energy to be applied to the movable unit such that a ratio of the electrical resistance matches the target value with respect to a target displacement amount of the displacement unit. Perform feedback control to adjust the amount.

A drive device according to a thirteenth aspect is the drive device according to the twelfth aspect, wherein at least one of the reference film and the deformation film stores a reference value of electric resistance in the reference value storage unit. A reference value storage unit that stores a reference value of the electrical resistance according to the above, and a detection unit that detects an actual electrical resistance value related to at least one of the reference film and the deformation film.

A drive device according to a fourteenth aspect is the drive device according to the thirteenth aspect, wherein the target value information is changed in accordance with a deviation amount from a reference value of the electrical resistance to the actual electrical resistance value. And an information changing unit.

A driving apparatus according to a fifteenth aspect is the driving apparatus according to the thirteenth aspect, wherein an electrical index determined with respect to an impedance relationship between the reference film and the deformation film and the electrical index A control information storage unit for storing control parameter information indicating the relationship between the amount of deviation from the target value of the current and the amount of change in the amount of energy supplied, and from the reference value of the electrical resistance to the value of the actual electrical resistance. An information changing unit that changes the control parameter information in accordance with the amount of deviation.

A drive device according to a sixteenth aspect is the drive device according to any one of the tenth to fifteenth aspects, wherein the reference film and the deformation film are electrically connected in series.

A camera module according to a seventeenth aspect includes a drive device according to any one of the tenth to sixteenth aspects, an image sensor, and an optical system that guides light from a subject to the image sensor. In the camera module, the movable unit moves at least one of the image sensor and the optical system according to the displacement of the displacement unit, thereby reducing the distance between the image sensor and the optical system. change.

The actuators according to any of the first to ninth aspects have the same thickness and quality of the reference film and the deformable film. For example, the information relating to the impedance relationship between the reference film and the deformable film Accordingly, the displacement can be controlled with high accuracy. Therefore, the displacement generated in the actuator can be accurately controlled with a simple configuration regardless of variations in the thickness and quality of the displacement control thin film generated between the actuators.

According to the actuator according to the third aspect, since the thickness and quality of the reference film and the deformation film are further similar, the displacement is controlled according to the information related to the impedance relationship between the reference film and the deformation film. Can be performed with higher accuracy.

According to the actuator according to the fifth aspect, it is possible to simplify the configuration for detecting the electrical state or electrical characteristics of the reference film and the deformation film.

Even in the actuator according to any of the seventh and ninth aspects, the configuration of the movable portion can be simplified.

The drive device according to any of the tenth to sixteenth aspects has the same thickness and quality of the reference film and the deformation film. For example, information relating to the impedance relationship between the reference film and the deformation film Accordingly, the displacement can be accurately controlled. Therefore, the displacement generated in the actuator can be accurately controlled with a simple configuration regardless of variations in the thickness and quality of the displacement control thin film generated between the actuators.

The drive device according to any of the thirteenth to fifteenth aspects can suppress the influence of changes and deterioration due to the environmental temperature of the deformation film on the displacement control in the actuator.

Also with the drive device according to the sixteenth aspect, the displacement generated in the actuator can be accurately controlled with a simpler configuration.

According to the camera module of the seventeenth aspect, the displacement generated in the actuator can be accurately controlled with a simple configuration regardless of variations in the thickness and quality of the displacement control thin film generated between the actuators. For this reason, the distance between the image sensor and the optical system can be changed with high accuracy.

FIG. 1 is a schematic diagram showing a schematic configuration of a mobile phone equipped with a camera module according to an embodiment and a modification. FIG. 2 is a schematic cross-sectional view focusing on the first housing according to the embodiment and the modification. FIG. 3 is a schematic cross-sectional view of a camera module according to an embodiment. FIG. 4 is a schematic side view of a camera module according to an embodiment. FIG. 5 is a schematic diagram showing the configuration of the lens group. FIG. 6 is a schematic diagram showing the configuration of the lens group. FIG. 7 is a schematic diagram illustrating the configuration of the lens group. FIG. 8 is a schematic diagram showing the configuration of the lens group. FIG. 9 is a schematic diagram showing the configuration of the lens group. FIG. 10 is a schematic top view showing the structure of the lens position adjusting layer. FIG. 11 is a schematic cross-sectional view showing the structure of the lens position adjusting layer. FIG. 12 is a schematic bottom view showing the configuration of the actuator layer. FIG. 13 is a schematic view of the configuration of the actuator layer viewed from the side. FIG. 14 is a diagram for explaining the configuration of the actuator layer. FIG. 15 is a diagram for explaining the configuration of the low thermal expansion layer. FIG. 16 is a diagram for explaining the configuration of the heat conductive layer. FIG. 17 is a diagram for explaining the configuration of the high thermal expansion layer. FIG. 18 is a diagram for explaining the configuration of the insulating layer. FIG. 19 is a diagram for explaining the configuration of the heater layer. FIG. 20 is a schematic bottom view illustrating a detailed configuration of an actuator layer according to an embodiment. FIG. 21 is a diagram for explaining the operation of the movable part. FIG. 22 is a diagram for explaining the operation of the movable part. FIG. 23 is a schematic bottom view showing the structure of the second parallel spring. FIG. 24 is a schematic diagram showing the relationship between the lens group and the second parallel spring. FIG. 25 is a schematic bottom view showing the structure of the first parallel spring. FIG. 26 is a schematic diagram showing the relationship between the lens group and the first parallel spring. FIG. 27 is a flowchart showing the manufacturing flow of the camera module. FIG. 28 is a flowchart showing a manufacturing flow of the actuator layer sheet. FIG. 29 is a schematic view illustrating the configuration of an actuator layer sheet. FIG. 30 is a diagram schematically showing the manufacturing process of the camera module. FIG. 31 is a block diagram illustrating a functional configuration for realizing feedback control of the displacement amount of the lens group according to an embodiment. FIG. 32 is a schematic bottom view illustrating a detailed configuration of an actuator layer according to a modification. FIG. 33 is a block diagram showing a functional configuration for realizing feedback control of the displacement amount of the lens group according to a modification. FIG. 34 is a block diagram showing a functional configuration for realizing feedback control of the displacement amount of the lens group according to a modification. FIG. 35 is a diagram conceptually illustrating a configuration of a camera module according to a 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 other 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 casing 200, a second casing 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 source 600 and the contrast detection unit 800 are mounted on the first casing 200. The current source 600 is a driver that controls supply of current to the heater layer 155 (FIGS. 19 and 20) of the actuator layer 15 (FIG. 3). The contrast detector 800 detects the contrast of the image signal obtained by the image sensor 181 (FIG. 3) of the camera module 500.

Also, in the second casing 300, a focusing control unit 310, a storage unit 320, and a variable resistor 330 are mounted on a circuit board that controls the overall operation of the mobile phone 100. The focus control unit 310 includes a CPU and a RAM, the storage unit 320 includes a non-volatile storage medium, and the variable resistor 330 includes, for example, a digital potentiometer. Composed.

Then, the focus control unit 310 is supplied to the heater layer 155 via the current source 600 in accordance with an electrical state (voltage in the present embodiment) in the camera module 500 and a signal input from the contrast detection unit 800. The amount of current supplied is controlled using various information stored in the storage unit 320 and a circuit including the variable resistor 330. Thereby, AF control for adjusting the in-focus state of the camera module 500 is executed.

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 3 mm. (MCU).

Hereinafter, the configuration of the camera module 500, the manufacturing process of the camera module 500, and the AF control in 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, and the direction indicated by the arrow AR1 in FIG. 3 corresponds to the + Z direction. In other drawings subsequent to FIG. 3, an arrow AR 1 indicating a direction corresponding to the + Z direction is appropriately attached in order to clarify the orientation relationship. FIG. 4 is a side view of the camera module 500 as viewed from the side.

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 the subject image.

The imaging unit PB has, for example, a configuration in which an imaging element layer 18 having an imaging element 181 such as a CMOS 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 further 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. The first parallel spring 12, the second parallel spring 14, and the actuator layer 15 cooperate with each other to move the lens group 20 in the direction along the 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 are fixed relatively to the lens group 20. Part (fixed part). The camera module 500 and the optical unit KB are manufactured in a wafer state (at the wafer level), and their four side surfaces (side surfaces parallel to the Z axis in FIG. 4) are cut surfaces formed by dicing. And in this cut surface, the laminated structure of the multiple layer which comprises the optical unit KB and the imaging part PB is exposed.

Here, the lens group 20 is supported by the 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 and the lens group 20 on the −Z side of the lens group 20 (the side on which the image sensor 181 is disposed). Further, a first parallel spring 12 is interposed between the first frame layer 11 and the lens group 20 on the + Z side (the side where the lid layer 10 is disposed) of the lens group 20. 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 (ie, −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, 14. 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. For this reason, even when a strong impact is applied to the camera module 500, the posture of the lens group 20 is maintained. In this non-driven state, the lens group 20 is placed at a predetermined position on the most −Z side of a range (displaceable range) that can be displaced along the Z axis and is stationary.

The predetermined position is, for example, a position where the focal point of the optical unit KB is disposed 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. Is set. 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.

The actuator layer 15 as an actuator has

movable portions

15a and 15b (FIG. 12) that generate drive displacement in the + Z direction, and is disposed on the −Z side of the lens group 20. The

movable portions

15a and 15b are in contact with the first protrusion 201 protruding to the −Z side of the lens group 20, and the drive displacement generated in the

movable portions

15a and 15b is transmitted to the lens group 20 via the first protrusion 201. Is done. 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

movable portions

15a and 15b is reduced, the lens group 20 is moved in the direction opposite to the predetermined direction (−Z) by the elastic force of the first and second parallel springs 12 and 14. Direction).

The side wirings 21a to 21c are thin conductive members disposed on one of the four side surfaces of the camera module 500, as shown in FIG. The side wirings 21a to 21c electrically connect the imaging element layer 18 and the heater layer 155 (FIG. 19). For this reason, the heater layer 155 (FIG. 19), the current source 600 and the variable resistor 330 are electrically connected to each other via the imaging element layer 18. Insulating portions 14ep are provided between the second parallel spring 14 and the side wirings 21a to 21c so that the side wirings 21a to 21c and the second parallel spring 14 are not short-circuited.

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

movable portions

15a and 15b of the actuator layer 15 and displaces the position along the Z axis. Therefore, 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 the camera module 500 can be used as a driving device for displacing the lens group 20. Make it work.

<(2-1) 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.

5 and 6 are schematic cross-sectional views of the lens group 20, and the direction indicated by the arrow AR2 corresponds to the + Z direction. 7 is a bottom view of the lens group 20 when the lens group 20 is viewed from below (−Z side), and FIG. 8 is a top view of the lens group 20 when the lens group 20 is viewed from above (+ Z side). It is.

As shown in FIGS. 5 and 6, 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. . Then, the first lens constituent layer LY1 and the second lens constituent layer LY2 are coupled via the spacer layer RB. Here, the outer edge of the cross section along the XY plane of the non-lens portion of the first and second lens constituent layers LY1, LY2 has a substantially square shape.

Further, as shown in FIGS. 5 to 7, the first lens constituting layer LY1 having the first lens G1 has a first main surface (here, −Z side) on the non-lens portion that does not function as a lens. A protrusion 201 is provided. Further, as shown in FIGS. 5, 6, and 8, a non-lens portion that does not function as a lens is formed on one main surface (here, + Z side) of the second lens constituent layer LY 2 having the second lens G 2. A second protrusion 202 is provided.

FIG. 9 is a view of the spacer layer RB as viewed from above (+ Z side), focusing on the shape of the spacer layer RB. As shown in FIG. 9, 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 shape of the outer edge and inner edge of the cross section along the XY plane is rectangular. It has the cyclic structure which is. Then, the optical axis of the lens group 20 is set in a direction along the Z axis.

<(2-2) 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.

<(2-2-1) Image sensor layer>
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 soldering by a reflow method 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. A terminal is provided.

Note that the current source 600 and the contrast detection unit 800 are provided on the circuit board of the second casing 300, for example, and the contrast detection unit 800 is electrically connected to the image sensor layer 18 by reflow soldering. For example, a mode in which the current source 600 is electrically connected to the actuator layer 15 via the imaging element layer 18 is conceivable.

<(2-2-2) Cover glass layer>
As shown in FIG. 3, the cover glass layer 17 has a substantially flat plate shape and has a substantially square cross section along the XY plane, 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.

<(2-2-3) Lens position adjustment layer>
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. 10 is a top view of the lens position adjusting layer 16 as seen from above (+ Z side). FIG. 11 is a cross-sectional view of the lens position adjusting layer 16 as viewed in the direction of the arrow at the cut surface XII-XII of the lens position adjusting layer 16. As shown in FIGS. 10 and 11, the lens position adjustment layer 16 includes a frame body 161 and a protrusion 162.

The frame body 161 is a substantially rectangular annular portion constituting the outer peripheral portion of the lens position adjusting layer 16, and has a plate shape substantially parallel to the XY plane. The frame body 161 forms a hole (through hole) 16H penetrating in the direction along the Z-axis. The + Y side plate-like member and the −Y side plate-like member constituting the frame body 161 are: Each plate-like portion has a portion (convex portion) 161T protruding from the lower portion to the through-hole 16H side. 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 connected to the adjacent actuator layer 15 (specifically, the frame body 15 f of the actuator layer 15 ( 12)).

The protrusion 162 is erected upward (+ Z direction) in the vicinity of the inner edge of the convex portion 161T provided on 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 comes into contact therewith.

Further, in FIG. 10, an area where a plurality of pixel circuits constituting the image sensor 181 are arranged (pixel arrangement area), that is, an outer edge of the front surface (imaging surface) of the image sensor 181 is indicated by a broken line. As shown in FIG. 10, the imaging surface is configured so that a relationship of (short side length) :( long side length) :( diagonal length) = 3: 4: 5 is established. . The two protrusions 162 are arranged at positions where the optical path from the subject through the lens group 20 to the pixel array area of the image sensor 181 is sandwiched in the direction in which the width of the pixel array area is the narrowest.

<(2-2-4) Actuator layer>
FIG. 12 is a bottom view of the actuator layer 15 as viewed from below (−Z side). FIG. 13 is a side view of the actuator layer 15 as seen from the side. FIG. 14 is a diagram schematically showing the layer structure of the actuator layer 15. FIGS. 15 to 19 are diagrams showing the configuration of each layer constituting the actuator layer 15.

As shown in FIG. 12, the actuator layer 15 includes a frame body 15f constituting the outer peripheral portion, and two plate-like movable portions projecting from the frame body 15f with respect to a hollow portion inside the frame body 15f. 15a and 15b. That is, the

movable parts

15a and 15b are fixed with respect to the frame 15f as a reference part. One main surface of the frame 15f is bonded to the adjacent lens position adjustment layer 16 (specifically, the frame 161), and the other main surface of the frame 15f is the adjacent second parallel spring 14. (Specifically, it is joined to the fixed frame 141 (FIG. 23)).

As shown in FIG. 14, the actuator layer 15 includes a low thermal expansion layer 151 (FIG. 15), a heat conduction layer 152 (FIG. 16), a high thermal expansion layer 153 (FIG. 17), an insulating layer 154 (FIG. 18), The heater layer 155 (FIG. 19) is laminated in this order from the + Z side to the −Z side. That is, the

movable parts

15a and 15b have a structure in which a plurality of layers including a low thermal expansion layer 151 and a high thermal expansion layer 153 and a heater layer 155 having different thermal expansion coefficients are stacked, that is, a so-called bimetal (Bi-metallic layer). Is adopted.

As shown in FIG. 15, the low thermal expansion layer 151 is composed of a frame portion 151f constituting the frame body 15f, and two plate-like protrusions projecting from the frame portion 151f with respect to a hollow portion inside the frame portion 151f. Protruding

portions

151a and 151b are provided. Here, the protruding portion 151a constitutes the movable portion 15a, and the protruding portion 151b constitutes the movable portion 15b. The low thermal expansion layer 151 is made of a material having a smaller coefficient of thermal expansion than the material forming the high thermal expansion layer 153. As a material constituting the low thermal expansion layer 151, for example, an iron / nickel alloy having a thermal expansion coefficient of 1.1 × 10 ⁻⁶ / ° C. is preferably employed. However, the thermal conductivity of this material is relatively low, about 8.8 W · m ⁻¹ · K ⁻¹ .

As shown in FIG. 16, the heat conductive layer 152 protrudes from the frame portion 152 f with respect to the frame portion 152 f constituting the frame body 15 f and the hollow portion inside the frame portion 152 f, similarly to the low thermal expansion layer 151. Two plate-like projecting

portions

152a and 152b are provided. Further, the heat conductive layer 152 is made of a material having a thermal conductivity larger than that of the material constituting the low thermal expansion layer 151 and the high thermal expansion layer 153. The material constituting the heat conducting layer 152, for example, copper and copper alloys thermal conductivity of 105.5W · m ^{^-1} · K ^-1, heat conductivity in 204W · m ^{^-1} · K ^-1 Any one of aluminum and nickel having a thermal conductivity of 90 W · m ⁻¹ · K ⁻¹ may be used.

As shown in FIG. 17, the high thermal expansion layer 153 protrudes from the frame portion 153f with respect to the frame portion 153f constituting the frame body 15f and the hollow portion inside the frame portion 153f, similarly to the low thermal expansion layer 151. Two plate-like projecting

portions

153a and 153b are provided. Here, the projecting portion 153a constitutes the movable portion 15a, and the projecting portion 153b constitutes the movable portion 15b. The high thermal expansion layer 153 is made of a material having a larger coefficient of thermal expansion than the material constituting the low thermal expansion layer 151. The material constituting the high thermal expansion layer 153, for example, iron-nickel-manganese alloy thermal expansion coefficient is 20 × 10 ^-6 / ℃, manganese-copper thermal expansion coefficient is 30 × 10 ^-6 / ℃ nickel alloy, any of the thermal expansion coefficient of 18 × 10 ^-6 / ℃ iron-nickel-chromium alloys is, and thermal expansion coefficient of 18 × 10 ^-6 / ℃ iron-molybdenum-nickel alloy is 1 One material is enough. However, the thermal conductivity of these materials is relatively low. For example, the thermal conductivity of an iron / nickel / manganese alloy is about 8.8 W · m ⁻¹ · K ⁻¹ .

As shown in FIG. 18, the insulating layer 154 protrudes from the frame portion 154f with respect to the frame portion 154f constituting the frame body 15f and the hollow portion inside the frame portion 154f, similarly to the low thermal expansion layer 151. Provided with two projecting portions 154a and 154b. Here, the projecting portion 154a constitutes the movable portion 15a, and the projecting portion 154b constitutes the movable portion 15b. The insulating layer 154 is made of an insulator such as silica (silicon dioxide). The insulating layer 154 is provided for the purpose of preventing a short circuit between the heater layer 155 and the high thermal expansion layer 153.

The heater layer 155 is patterned on the back surface (the surface on the −Z side) of the insulating layer 154 and is made of a conductive metal such as gold (Au). As shown in FIG. 19, the heater layer 155 includes first to third electrode parts E1 to E3, a reference conductor part 155s as a reference film, first and second heater parts 155ha and 155hb as deformation films, And first to third wiring portions 155c1 to 155c3. The first to third electrode portions E1 to E3, the reference conductor portion 155s, and the first to third wiring portions 155c1 to 155c3 constitute a frame body 15f, and the heater portion 155ha constitutes a movable portion 15a. And the heater part 155hb comprises the movable part 15b. Hereinafter, the first and second heater portions 155ha and 155hb are collectively referred to as “heater portion 155h” as appropriate.

Specifically, the first electrode part E1 and the second electrode part E2 are electrically connected by the reference conductor part 155s, and the second electrode part E2 and the third electrode part E3 are connected to the first heater part 155ha and the first electrode part 155ha. The two wiring parts 155c2 are electrically connected by wirings connected in this order (hereinafter also referred to as “one wiring”), and the first wiring part 155c1, the second heater part 155hb, and the third wiring part 155c3 are connected. They are electrically connected by wirings connected in this order (hereinafter also referred to as “other wirings”).

In the present embodiment, a potential difference is applied between the first electrode portion E1 and the third electrode portion E3, and a current flows. For this reason, one wiring and the other wiring are electrically connected in parallel between the second electrode portion E2 and the third electrode portion E3, and the reference conductor portion 155s is connected to the one wiring and the other wiring. Are electrically connected in series. That is, here, the heater portion 155h and the reference conductor portion 155s are formed using the same material and included in an integral film, and the heater portion 155h and the reference conductor portion 155s are electrically connected in series. Connected to.

FIG. 20 is a schematic diagram showing a detailed configuration of the actuator layer 15 as viewed from the back side (−Z side).

As shown in FIG. 20, each of the first to third electrode portions E1 to E3 has one plate-like shape among the four plate-like portions (first to fourth plate-like portions) constituting the frame body 15f. Provided in the portion (first plate-like portion). Specifically, the second electrode portion E2 is provided near one end in the longitudinal direction of the first plate-like portion, and the third electrode portion E3 is provided near the other end in the longitudinal direction of the first plate-like portion. In addition, the first electrode portion E1 is provided near the center in the longitudinal direction of the first plate-like portion. Here, the first to third electrode portions E1 to E3 serve as terminal portions that can be electrically connected to various elements and the like disposed outside the actuator layer 15 through various wirings and the like. The reference conductor portion 155s is disposed from the vicinity of one end of the first plate member to the vicinity of the center.

Further, the first wiring portion 155c1 is formed in substantially the entire area in the longitudinal direction in the second and third plate-like portions forming two sides adjacent to each other among the first to fourth plate-like portions constituting the frame body 15f. It extends in a letter shape. The second wiring portion 155c2 extends along the longitudinal direction in the first plate-like portion where the first electrode portion E1 is disposed. The third wiring portion 155c3 extends along the vicinity of the end portion of the third plate-like portion and the region near the entire area in the longitudinal direction of the fourth plate-like portion.

The first heater portion 155ha extends from the vicinity of the fixed portion (fixed end) fixed to the frame 15f, which is one end in the longitudinal direction of the movable portion 15a, to the vicinity of the other end (free end FT). , Folded in the vicinity of the free end FT, and further extended from the free end FT to the fixed end. With such a configuration, the pattern of the elongated first heater portion 155ha is disposed over substantially the entire area on the back surface side of the movable portion 15a. The second heater portion 155hb extends from the vicinity of the portion (fixed end) fixed to the frame 15f that is one end in the longitudinal direction of the movable portion 15b to the vicinity of the other end (free end FT), It is folded in the vicinity of the free end FT and further extends from the free end FT to the fixed end. With such a configuration, the pattern of the elongated second heater portion 155hb is disposed over substantially the entire back surface side of the movable portion 15b.

The reference conductor portion 155s, the first to third electrode portions E1 to E3, the first to third wiring portions 155c1 to 155c3, and the first and second heater portions 155ha have substantially the same film thickness. The first and second heater portions 155ha and 155hb are sufficiently narrower and narrower than the reference conductor portion 155s, the first to third electrode portions E1 to E3, and the first to third wiring portions 155c1 to 155c3. Form. Therefore, in the wiring that electrically connects the first electrode portion E1 and the third electrode portion E3, the reference conductor portion 155s, the first to third electrode portions E1 to E3, and the first to third wiring portions 155c1. The first and second heater portions 155ha and 155hb are configured to have higher electrical resistance than ˜155c3.

Accordingly, when a voltage is applied between the first electrode portion E1 and the third electrode portion E3, the first and second heater portions 155ha and 155hb having relatively high electric resistance generate heat due to their own Joule heat. . That is, the first and second heater portions 155ha and 155hb generate heat in response to the supply of power energy. The first to third electrode portions E1 to E3 are exposed on the side surface of the camera module 500 in the dicing process. The exposed first to third electrode portions E1 to E3 of the heater layer 155 are provided with side wirings 21a to 21b (FIGS. 3 and 4), respectively, so that voltage is supplied via the

side wirings

21a and 21c. And current is supplied.

FIG. 21 and FIG. 22 are schematic views showing a mode in which the

movable portions

15a and 15b are deformed in response to heat generated by the first and second heater portions 155ha and 155hb. In addition, since the deformation | transformation aspect of

movable part

15a, 15b is respectively the same, in FIG.21 and FIG.22, the deformation | transformation aspect of the movable part 15a is shown as an example, Here, deformation | transformation of the movable part 15a is shown. An embodiment will be described as an example.

As shown in FIG. 21, the movable portion 15a has a flat shape when the first heater portion 155ha is not generating heat.

On the other hand, as shown in FIG. 22, the protruding portion 153 a of the high thermal expansion layer 153 becomes the protruding portion of the low thermal expansion layer 151 due to heat generated in response to the supply of electrical energy to the first heater portion 155 ha. It expands more than 151a. Here, the amount of heat generated by the first heater portion 155ha exceeds the amount of heat released from the projecting

portions

151a and 153a to the surrounding atmosphere and the frame 15f, whereby the temperature of the movable portion 15a increases. If the thickness of the movable portion 15a is made very thin, such as about 30 to 50 μm, the temperature of the movable portion 15a rises in a relatively short time. When the temperature of the movable portion 15a rises, the movable portion 15a is counteracted with the fixed end fixed to the frame body 15f as a fulcrum due to the difference in expansion between the protruding portion 151a and the protruding portion 153a. The free end FT as the displacement portion is displaced upward (+ Z direction). At this time, the first heater portion 155ha is also deformed along with the deformation of the movable portion 15a.

On the other hand, when the energization to the first heater portion 155ha is stopped, the heat of the movable portion 15a is rapidly transmitted to the frame body 15f due to the presence of the heat conductive layer 152, and the movable portion 15a is rapidly moved by heat dissipation from the frame body 15f. To be cooled. At this time, the upward displacement (+ Z direction) of the free end FT is reduced, and the movable portion 15a returns to a flat shape as shown in FIG.

Incidentally, the shape and electric resistance in the first heater portion 155ha have a unique relationship, and the displacement amount of the lens group 20 and the shape of the first heater portion 155ha have a unique relationship. For this reason, it is possible to control the amount of displacement of the lens group 20 using the change in the electrical resistance of the first heater portion 155ha. Since the control of the displacement amount of the lens group 20 is included in the AF control of the camera module 500, it will be described later.

Here, since the reference conductor portion 155s is provided on one main surface of the frame body 15f, the reference conductor portion 155s is not substantially deformed together with the frame body 15f regardless of the deformation of the

movable portions

15a and 15b. Retain shape.

<(2-2-5) Second parallel spring>
FIG. 23 is an external view of the lower surface of the second parallel spring 14 when the second parallel spring 14 is viewed from below (−Z direction). FIG. 24 is a diagram showing the second parallel spring 14 joined to the lens group 20. As shown in FIG. 23, the second parallel spring 14 is an elastic member having a fixed frame body 141 and an elastic portion 142, and is a layer (elastic layer) forming a spring mechanism.

The fixed frame 141 constitutes the outer peripheral portion of the second parallel spring 14 and is joined to the frame 15f of the adjacent actuator layer 15. Here, the distance between the heater layer 155 of the actuator layer 15 and the second parallel spring 14 is usually narrow. Therefore, when the side wirings 21a to 21c for supplying voltage and current to the heater layer 155 are simply provided from the imaging element layer 18 to the actuator layer 15 by printing or the like, for example, the side wirings 21a to 21c are formed on the fixed frame 141. It may take up to. That is, the side wirings 21a to 21c and the second parallel spring 14 may be short-circuited.

Therefore, for the purpose of preventing this short circuit, a notch 143 that is recessed near the both ends of the plate-like member constituting one side of the fixed frame 141 of the second parallel spring 14 and at the outer edge near the center thereof is provided. The notch 143 is an epoxy system used for joining when the second frame layer 13 and the second parallel spring 14 are joined and when the second parallel spring 14 and the actuator layer 15 are joined. Insulating part 14ep (FIGS. 3 and 4) is formed by filling an adhesive such as resin. Due to the presence of the insulating portion 14ep, unnecessary short circuit due to contact between the side wirings 21a to 21c and the second parallel spring 14 is prevented.

The elastic part 142 has a connection part PG1 with the fixed frame body 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. 24, the second parallel spring 14 is joined to the lens group 20 at a joint portion PG 2 provided in the elastic portion 142. Here, the first protrusion 201 contacts the free end FT of the actuator layer 15 through the gap between the fixed frame 141 of the second parallel spring 14 and the plate member EB.

Then, as the lens group 20 is moved in the + Z direction with respect to the fixed frame 141, the positions of the connecting portion PG1 and the joint portion PG2 shift in the Z direction, and the plate-like member EB undergoes bending deformation (deflection deformation). Bend. 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 a photolithography technique, and dipped in an iron chloride-based etching solution to be wet. Etching is performed to form a parallel spring pattern.

<(2-2-6) Second frame layer>
As shown in FIG. 3, the second frame layer 13 is an annular member whose outer edge and inner edge in a cross section along the XY plane are each substantially rectangular, and forms a hollow portion penetrating 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. The upper end surface (other main surface) located on the + Z side of the second frame layer 13 is adjacent to the adjacent first parallel spring 12 (specifically, the fixed frame body 121 (FIG. 25) of the first parallel spring 12). Be joined.

<(2-2-7) First parallel spring>
FIG. 25 is an external view of the lower surface of the first parallel spring 12 when the first parallel spring 12 is viewed from below (−Z direction). As shown in FIG. 25, the first parallel spring 12 is an elastic member having the same configuration and function as the second parallel spring 14 except that the notch portion 143 is not provided. 121 and an elastic part 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 1 frame layer 11 at the −Z side lower end surface).

FIG. 26 is a view showing the first parallel spring 12 joined to the lens group 20. As illustrated in FIG. 26, the joint portion PG 2 provided in the elastic portion 122 is joined to the upper end surface on the + Z side of the protrusion 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-like member EB, and the first parallel spring 12 functions as a spring mechanism.

<(2-2-8) First frame layer>
As shown in FIG. 3, the first frame layer 11 is an annular member in which the outer edge and the inner edge of the cross section along the XY plane are each substantially rectangular like the second frame layer 13, and extends along the Z axis. To form a hollow portion penetrating through. The hollow portion of the first frame layer 11 becomes a space in which the plate-like member EB and the protruding portion 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 is joined to the adjacent lid layer 10 (specifically, near the outer peripheral portion of the lid layer).

<(2-2-9) Lid layer>
As shown in FIG. 3, the lid layer 10 has a substantially square outer edge in a cross section along the XY plane, and has a hole (through hole) 10 H penetrating in a direction parallel to the Z axis at a substantially center. It is a plate-like member having a board surface substantially parallel to the XY plane. 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, for example, a technique of pressing a flat resin material or a resin material. The through-hole 10H is formed by a technique such as etching after patterning.

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.

<(3) Camera module manufacturing process>
Here, a manufacturing process of the camera module 500 will be briefly described. FIG. 27 is a flowchart showing the manufacturing process of the camera module 500. As shown in FIG. 27, (process A) generation of the lens group 20 (step SP1), (process B) sheet preparation (step SP2), (process C) assembly jig preparation (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.

<(3-1) Generation of Lens Group (Process A)>
In step SP1, the lens group 20 is generated. Here, 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. Group 20 is 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 laminated and bonded together.

<(3-2) Preparation of sheet (Process B)>
In step SP2, a sheet relating to each functional layer constituting the camera module 500 is formed for each layer. Here, a disc-shaped sheet at the wafer level is prepared. A large number of chips corresponding to members related to the functional layer are formed in a matrix on the sheet for each functional layer. Specifically, in step SP2, the functions such as 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, and the lens position adjustment layer 16 are performed. Each of the sheets U10 to U16 in which a large number of chips relating to the layers are formed in a predetermined arrangement, and a large number of chips relating to the image pickup element substrate 178 formed by joining the cover glass layer 17 and the image pickup element layer 18 are formed in a predetermined arrangement. Prepared sheets (imaging element substrate sheets) U178 are prepared. That is, eight sheets U10 to 16 and U178 are prepared. In each of the sheets U10 to U16, U178, alignment marks for alignment are formed at two or more predetermined positions.

FIG. 28 is a flowchart showing a manufacturing flow of a sheet (actuator layer sheet) U15 in which a number of actuator layers 15 are arranged. Here, a manufacturing method of the actuator layer sheet U15 will be described with reference to FIG.

First, in step ST21, a bimetallic flat plate is prepared. Here, a bimetallic disk-shaped wafer is prepared in which a layer corresponding to the low thermal expansion layer 151, a layer corresponding to the heat conductive layer 152, and a layer corresponding to the high thermal expansion layer 153 are stacked. As for the disk-shaped wafer, for example, a laminated body in which three flat plates of materials constituting the low thermal expansion layer 151, the heat conductive layer 152, and the high thermal expansion layer 153 are stacked is rolled into a disk shape. It is made by punching.

In step ST22, an insulating layer is formed on the bimetallic flat plate prepared in step ST21 by vapor deposition or the like.

In step ST23, a resist film pattern is formed on the insulating layer formed in step ST22 by photolithography or the like. The resist film pattern formed here is a pattern in which patterns corresponding to the shape of the heater layer 155 are arranged in a matrix.

In step ST24, a thin film of metal (for example, gold) is formed on the insulating layer on which the resist film pattern is formed in step ST23 by sputtering or the like. In forming a metal thin film by sputtering, it is difficult to reproduce the same thickness repeatedly. However, here, the respective parts constituting the heater layer 155 (first to third electrode parts E1 to E3, reference conductor part 155s, first and second heater parts 155ha and 155hb, and first to third wiring parts 155c1 to 155c1) 155c3) are simultaneously formed in the same process using the same material. At this time, normally, even if the metal thin film is formed by the same batch process, the film thickness and film quality tend to be different from the whole wafer. However, when attention is paid to a region corresponding to the chip of one actuator layer 15, each part constituting the heater layer 155 is formed in a very close region. For this reason, the thickness and film quality of each part which comprises the heater layer 155 become substantially the same. And as this film quality, the state of a crystal (metal structure) etc. are mentioned, for example.

In step ST25, the metal thin film formed on the resist film pattern in step ST24 is removed together with the resist film pattern by the lift-off method. At this time, a metal thin film pattern in which patterns corresponding to the heater layer 155 are arranged in a matrix is completed.

In step ST26, the hollow portion of each actuator layer 15 is formed by press working or the like. At this time, the actuator layer sheet U15 is completed. FIG. 29 is a schematic diagram showing the configuration of the actuator layer sheet U15. In FIG. 29, a configuration focusing on a part of the actuator layer sheet U15 is shown, and the thick broken lines indicate the boundary lines of a plurality of chips respectively corresponding to the actuator layer 15.

<(3-3) Preparation of assembly jig (Process C)>
In step SP3 of FIG. 27, an assembly jig is prepared. The assembling jig is configured by providing a plurality of protrusions having substantially the same shape on a flat base in a predetermined arrangement. In the assembly jig, alignment marks for alignment are formed at two or more predetermined locations. The upper surface of the protrusion is configured to be substantially parallel to the main surface of the flat base. A unit corresponding to the camera module 500 is manufactured on the upper surface of each protrusion.

<(3-4) Sheet First Joining (Step D)>
In step SP4, three sheets U11 to U13 of the eight sheets U10 to U16 and U178 prepared in step SP2 are joined. Here, the first frame layer sheet U11, the first parallel spring sheet U12, and the second frame layer sheet U13 are aligned in the sheet shape so that the chips included in the sheets U11 to U13 are stacked on each other. (Alignment) is performed. Then, the sheets U11 to U13 are joined using an adhesive or the like.

FIG. 30 shows a state in which three sheets U11 to U13 are laminated and joined in step SP4, a lens group 20 is attached in step SP5, and four sheets U10 and U14 to U16 are laminated in step SP6. 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 by step SP7.

<(3-5) Attaching the lens group (Process E)>
In step SP5, the lens group 20 produced | generated by step SP1 is each attached to the hollow part of each 2nd frame layer 13 of the unit produced by step SP4 with 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. Here, while the lens group 20 is pressed against the joint PG2, the end surface of the second protrusion 202 is joined to the one main surface side of the joint PG2. In addition, as this joining method, the method etc. which join using the adhesive agent (UV curing adhesive) hardened | cured by irradiation of an ultraviolet-ray are mentioned.

<(3-6) Sheet second joining (process F)>
In step SP6, four sheets U10, U14 to U16 of the eight sheets U10 to U16 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 one main surface side of the actuator layer sheet U15 using an adhesive or the like.

<(3-7) Mounting of image pickup device substrate (process G)>
In step SP7, the outer peripheral portion of the image sensor substrate 178 is bonded to the frame 161 of each lens position adjustment layer 16 of the unit formed by bonding the lens position adjustment layer 16 by step SP6. The other principal surface of the imaging element substrate sheet U178 is joined to one principal surface of the lens position adjustment layer sheet U16.

<(3-8) Dicing (Process H)>
In step SP8, a large number of lens groups 20 are respectively 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. The actuator layer sheet U15 is cut along the thick broken line shown in FIG.

Further, the side wirings 21a to 21c are formed during the dicing process. Specifically, when dicing along one direction is performed, each heater layer 155 is exposed at a cut surface corresponding to the side surface of each camera module 500. Therefore, a conductive material for forming the side wirings 21a to 21c is applied to the cut surface, and then dicing along the other direction is performed, so that a large number of camera modules 500 are completed.

<(4) AF control in camera module>
<(4-1) Functional configuration related to feedback control of lens group displacement>
FIG. 31 is a block diagram showing a functional configuration for realizing feedback control of the displacement amount of the lens group 20 in the AF control of the camera module 500. Here, in order to prevent the description from becoming complicated, the wiring other than the reference conductor portion 155s and the heater portion 155h in the heater portion 155 will be described as having an electrical resistance that is small enough to be ignored.

As shown in FIG. 31, a current is supplied from a current source 600 to a reference conductor portion 155s and a heater portion 155h that are electrically connected in series. Specifically, the current source 600 is electrically connected to the reference conductor portion 155s via the first electrode portion E1, and the reference conductor portion 155s and the heater portion 155h are connected via the second electrode portion E2. The heater portion 155h is electrically connected to the ground wiring GND through the third electrode portion E3. That is, the third electrode portion E3 is grounded. With such an aspect, it is possible to flow current from the current source 600 in the order of the reference conductor portion 155s and the heater portion 155h.

The variable resistor 330 is configured using, for example, a so-called digital potentiometer. One electrode portion of the variable resistor 330 is electrically connected to the first electrode portion E1, and the other electrode portion of the variable resistor 330 is electrically connected to the ground wiring GND. For this reason, the other electrode portion is grounded, and a voltage V _ref is applied between the one electrode portion and the other electrode portion. Specifically, the first electrode portion E1 and the third electrode sandwiching the reference conductor portion 155s and the heater portion 155h electrically connected in series between one electrode portion and the other electrode portion of the variable resistor 330. The same voltage V _ref as that applied between the part E3 and the part E3 is applied. The slidable electrode portion (slide electrode portion) of the variable resistor 330 is electrically connected to a feedback control unit 312 described later.

Here, the electric resistance between the one electrode part and the other electrode part of the variable resistor 330 is set to be sufficiently larger than the total value of the electric resistances of the reference conductor part 155s and the heater part 155h. It is preferable. By adopting such a setting, since a relatively small current flows through the variable resistor 330, unnecessary heat generation is suppressed, and as a result, power consumption is suppressed.

The focus control unit 310 includes a resistance control unit 311 and a feedback control unit 312 as functional configurations. The second electrode unit E2 is electrically connected to the feedback control unit 312 and the slide electrode unit of the variable resistor 330 is electrically connected to the feedback control unit 312.

The resistance control unit 311 changes the position of the slide electrode unit in the variable resistor 330, that is, the partial pressure, by referring to information (target value information) stored in a target value storage unit 321 described later.

The feedback control unit 312 includes a voltage (sense voltage) V _sns applied between the second electrode unit E2 and the third electrode unit E3, and a voltage between the slide electrode unit and the other electrode unit of the variable resistor 330. depending on the relationship between the (divided voltage) V _vr, adjusts the amount of current flowing through the reference conductor portion 155s and the heater portion 155h from the current source 600. Here, the voltage V _vr is input as a positive value and the voltage V _sns is input as a negative value to the feedback control unit 312. Then, the feedback control unit 312 refers to information (gain information) stored in the gain storage unit 322 according to a numerical value (V _vr −V _sns ) _obtained by subtracting the sense voltage V _sns from the _divided voltage V _vr. Then, a control signal for adjusting the current amount I _drv flowing from the current source 600 through the reference conductor portion 155 s and the heater portion 155 h is output to the current source 600.

The feedback control unit 312 is set to have a sufficiently high impedance (input impedance) related to input from the second electrode unit E2 and the slide electrode unit. This is because a large current does not flow through the feedback control unit 312 and the current easily flows through the heater unit 155h and the like, which contributes to detection of a weak signal in the feedback control unit 312.

The storage unit 320 includes a target value storage unit 321 and a gain storage unit 322.

The target value storage unit 321 obtains the ratio of the electrical resistance (reference film resistance) R _{ref of} the reference conductor portion 155s and the electrical resistance (deformed film resistance) R _sns of the heater portion 155h, which is obtained in advance by measurement, and the lens group 20 Is stored information (target value information) indicating the relationship with the amount of displacement in the + Z direction (that is, the amount of displacement of the free end FT). Specifically, each displacement amount of the free end FT in increments of a predetermined amount is set as a target displacement amount. For each target displacement amount, the corresponding electric resistance (reference film resistance) R _{ref of} the reference conductor portion 155s and the electric power of the heater portion 155h. A ratio with the resistance (deformed membrane resistance) R _sns is stored as a target value. When the

movable parts

15a and 15b are in a non-driving state having a flat plate shape, the ratio between the electric resistance R _ref and the electric resistance R _sns is determined by design.

The gain storage unit 322 _generates a value (V _vr -V _sns ) _obtained by subtracting the sense voltage V _sns from the _divided voltage V _vr from the current source 600 for each value (V _vr -V _sns ) in increments of a predetermined value. Information (control parameter information) associated with a change amount (specifically, an amount to increase the current) of the electric energy supplied to the reference conductor portion 155s and the heater portion 155h is stored. Here, each numerical value (V _vr −V _sns ) is a sense voltage V _sns , which is an electrical index determined by the electrical resistance relationship between the reference conductor portion 155 s and the heater portion 155 _h, and the electrical resistance. This corresponds to the amount of deviation from the _divided voltage _Vvr , which is the target value of the electrical index determined by the relationship.

<(4-2) Operation related to feedback control of lens group displacement>
Here, an operation relating to feedback control of the displacement amount of the lens group 20 will be described with reference to FIG. Here, as described above, the reference film resistance related to the reference conductor portion 155s is R _ref , the deformation film resistance related to the heater portion 155h is R _sns , and is applied between the first electrode portion E1 and the third electrode portion E3. V _{ref is} a reference voltage to be applied, V _sns is a sense voltage applied between the second electrode portion E2 and the third electrode portion E3, and a _divided voltage of the slide electrode portion is V _vr. Let I _drv be the current (drive current) supplied to the reference conductor portion 155s and the heater portion 155h.

First, the reference voltage V _ref is _expressed by the following expression (1) using the drive current I _drv , the reference film resistance R _ref , and the deformation film resistance R _sns .

V _ref = I _drv × (R _ref + R _sns ) (1)

The sense voltage V _sns is _expressed by the following expression (2) using the reference voltage V _ref , the reference film resistance R _ref , and the deformation film resistance R _sns .

V _sns = R _sns / (R _ref + R _sns ) × V _ref (2)

In addition, the resistance value (first voltage _dividing resistance value) between one electrode portion to which the reference voltage V _ref of the variable resistor 330 is applied and the slide electrode portion is set to R1, and the slide electrode portion and the ground are grounded. Assuming that the resistance value (second voltage _dividing resistance value) between the other electrode part is R2, the _divided voltage V _vr related to the slide electrode part of the variable resistor 330 is expressed by the following expression (3).

V _vr = R2 / (R1 + R2) × V _ref (3)

Here, the feedback control unit 312 compares the input _divided voltage V _vr with the sense voltage V _sns, and if the _divided voltage V _vr is larger than the sense voltage V _sns , the drive current I _drv is increased. Such a control signal is output to the current source 600. On the other hand, if the _divided voltage V _vr is smaller than the sense voltage V _sns , a control signal is output to the current source 600 so that the drive current I _drv decreases.

That is, when the relationship of V _vr > V _sns is established, that is, when the relationship of the following equation (4) is established, control is performed such that the drive current I _drv is increased.

R2 / (R1 + R2)> R _sns / (R _ref + R _sns ) (4)

At this time, in the actuator layer 15, the deformation amount of the

movable parts

15a and 15b increases. Then, the drive current I _drv increases until the value on the left side and the value on the right side of the above equation (4) have an equivalent relationship.

On the other hand, when the relationship of V _vr <V _sns is established, that is, when the relationship of the following equation (5) is established, control is performed such that the drive current I _drv is reduced.

R2 / (R1 + R2) <R _sns / (R _ref + R _sns ) (5)

At this time, in the actuator layer 15, the deformation amount of the

movable parts

15a and 15b decreases. Then, the drive current I _drv decreases until the value on the left side and the value on the right side of the above equation (5) have an equivalent relationship.

In this way, the ratio between the reference _voltage resistance R _ref and the deformed film resistance R _sns is set to the target value with the ratio of the first _{voltage dividing} resistance value R1 and the second _{voltage dividing} resistance value R2 in the variable resistor 330 as the target value. Feedback control of the drive current I _drv is performed so as to be equivalent to the value. Specifically, the electrical applied to the

movable portions

15a and 15b in accordance with the sense voltage V _sns as electrical information determined corresponding to the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h. Energy supply is controlled.

Incidentally, the absolute values of the electric resistances of the reference conductor portion 155s and the heater portion 155h tend to vary slightly for each actuator layer 15 due to the manufacturing process. However, in one actuator layer 15 according to the present embodiment, since the reference conductor portion 155s and the heater portion 155h are formed at the same time in the same process, the film thickness and the like between the reference conductor portion 155s and the heater portion 155h are reduced. The film quality is substantially the same. For this reason, the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h is a value corresponding to the amount of deformation of the heater portion 155h. That is, the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h and the deformation amount of the heater portion 155h have a one-to-one relationship. In this embodiment, the amount of displacement of the free ends FT of the

movable portions

15a and 15b is controlled so that the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h matches the target value.

Here, the wiring other than the reference conductor portion 155s and the heater portion 155h in the heater portion 155 has been described as being small enough to ignore the electric resistance, but is not limited thereto. For example, the reference voltage V _ref and the sense voltage V _sns may be handled by adding the electric resistances related to the wiring other than the reference conductor portion 155s and the heater portion 155h to the reference film resistance R _ref and the deformation film resistance R _sns , respectively. good.

<(4-3) AF control operation>
The focus control unit 310 changes the separation distance between the lens group 20 and the image sensor 181 by the feedback control of the displacement amount of the lens group 20 described above, and the focus position of the optical unit KB is changed.

The contrast detection unit 800 shown in FIG. 1 detects the contrast of the image signal obtained by the image sensor 181. 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 related to the evaluation value indicating the contrast is output to the focus control unit 310.

When performing AF control, first, the separation distance between the lens group 20 and the image sensor 181 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 image sensor 181 in the set state. In other words, the extension position of the lens group 20 in the + Z direction is set to a preset multistage position, and an image signal is output by the image sensor 181 at the time when the lens group 20 is disposed at each extension position. To be acquired. At this time, the feeding position of the lens group 20 is changed by feedback control of the displacement amount of the lens group 20 by the focus control unit 310.

Next, the focus control unit 310 detects a feeding position where 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 group 20 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. For this reason, focusing on the subject in the camera module 500 is realized by moving the lens group 20 to the extended position where the evaluation value indicating the contrast is maximized under the control of the focusing control unit 310. That is, AF control is realized.

As described above, in the camera module 500 according to this embodiment, the thickness and film quality of the reference conductor portion 155s and the heater portion 155h are the same. For this reason, the displacement control according to the relationship of the electrical resistance between the reference conductor portion 155s and the heater portion 155h is accurately performed. Therefore, the displacement generated in the actuator can be accurately controlled with a simple configuration regardless of variations in the thickness and quality of the displacement control thin film generated between the actuators. In addition, since it is possible to perform highly accurate displacement control in the actuator with a simple configuration, it is possible to suppress an increase in cost required for manufacturing the actuator.

Further, in the same actuator, the thickness and film quality of the reference conductor portion 155s and the heater portion 155h are the same. For this reason, it becomes possible to control the displacement according to the relationship of the electrical resistance between the reference conductor portion 155s and the heater portion 155h with higher accuracy.

Further, the reference conductor portion 155s and the heater portion 155h are included in the heater layer 155 which is an integral film. For this reason, the structure for detecting an electrical state such as a voltage applied to the reference conductor portion 155s and the heater portion 155h can be simplified. Further, the reference conductor portion 155s and the heater portion 155h are electrically connected in series, so that the wiring and configuration outside the actuator layer 15 can be simplified as compared with the case where they are not connected in series. Therefore, the displacement generated in the actuator can be accurately controlled with a simpler configuration.

Further, since the heater portion 155h also serves as a deformation film for controlling the deformation, the configuration of the

movable portions

15a and 15b can be simplified.

<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, in the heater layer 155, the reference conductor portion 155s and the heater portion 155h are included in an integral film and electrically connected in series. However, the present invention is not limited to this. For example, in the heater layer, the reference conductor portion and the heater portion may not be included in the integral film and may be spaced apart from each other. Hereinafter, a specific example will be described.

FIG. 32 is a diagram schematically showing a detailed configuration of an actuator layer 15A according to a modification. Compared with the camera module 500, the first casing 200, and the mobile phone 100 according to the above-described embodiment shown in FIGS. 1 to 3, the camera module 500A according to the present modification, the first casing, and the first casing 200 are compared. The body 200A and the mobile phone 100A have the actuator layer 15 changed to an actuator layer 15A having a different configuration. As shown in FIG. 32, compared to the actuator 15 according to the above-described embodiment, the actuator layer 15A according to the present modified example is different from the heater layer 155A in which the movable portion 15b is removed and the heater layer 155 has a different configuration. It has been changed. Further, a side wiring and a configuration matched to the side wiring are adopted according to the configuration of the heater layer 155A. Other configurations are almost the same. In addition, about the structure similar to the actuator 15 which concerns on the said one Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

As shown in FIG. 32, the heater layer 155A includes first to fourth electrode portions EA1 to EA4, a reference conductor portion 155sA, a first heater portion 155ha, and a wiring portion 155cA that are simultaneously formed in the same process such as sputtering. Is provided. The reference conductor portion 155sA electrically connects the first electrode portion EA1 and the second electrode portion EA2. Further, the third electrode part EA3 and the fourth electrode part EA4 are electrically connected by the wiring arranged in the order of the first heater part 155ha and the wiring part 155cA. In addition, about the frame 15f which concerns on the said one Embodiment, since the structure of 155A of heater layers has a different structure from the heater layer 155 which concerns on the said one Embodiment, it is changed into the frame 15fA in this modification. .

Even if such a configuration is adopted, for example, if wiring outside the actuator layer 15A is devised, the functional configuration for realizing feedback control of the displacement amount of the lens group 20 shown in FIG. It can also be realized.

The reference conductor portion 155sA and the first heater portion 155ha are not electrically connected in series, and a current source is provided separately for the reference conductor portion 155sA and the first heater portion 155ha, and a so-called current mirror is provided. A configuration in which the same current is supplied to the reference conductor portion 155sA and the first heater portion 155ha using a circuit is also conceivable. In such a configuration, for example, the absolute values of the electrical resistances of the reference conductor portion 155sA and the first heater portion 155ha are detected, the ratio of the electrical resistances is calculated, and the lens group is calculated using the electrical resistance ratio. It is also possible to control 20 displacement amounts.

In the above embodiment, the absolute values of the electrical resistances of the reference conductor portion 155s and the heater portion 155h were not measured, but the present invention is not limited to this. For example, the measured value of the electrical resistance of at least one of the reference conductor part 155s and the heater part 155h is monitored as an index of the amount of deformation caused by the environmental temperature of the reference conductor part 155s and the heater part 155h, and the measured electric resistance is measured. Various information used for feedback control of the displacement amount of the lens group 20 may be changed according to the change in value. Here, a mode for compensating for the deformation amount caused by the environmental temperature of the reference conductor portion 155s and the heater portion 155h using the actual measured values of the electric resistance of the reference conductor portion 155s and the heater portion 155h will be described with a specific example. .

FIG. 33 is a block diagram showing a functional configuration for realizing feedback control of the displacement amount of the lens group 20 in the AF control of the camera module 500 according to one modification. Here, as compared with the block diagram shown in FIG. 31, a resistance detector 703 for detecting the electrical resistance (reference film resistance) R _ref of the reference conductor portion 155s and the electrical resistance (deformed film resistance) R of the heater portion 155h. A resistance detection unit 704 that detects _sns , a target value change unit 313, and a reference resistance storage unit 323 are added. Here, the reference resistance storage unit 323 only needs to be added to the storage unit 320. For example, the reference resistance storage unit 323 is configured by an EEPROM or the like, and the absolute value of the electrical resistance related to the reference conductor unit 155s and the heater unit 155h at the time of shipment is the reference. Stored as a value. The target value changing unit 313 may be functionally realized in the focusing control unit 310.

For example, in the non-driving state, from the reference value related to the reference film resistance R _ref stored in the reference resistance storage unit 323 to the actual value (actual measurement value) of the reference film resistance R _ref detected by the resistance detection unit 703. The amount of deviation (specifically, the direction of deviation such as positive and negative and the absolute value of the amount of deviation) is the amount of variation in the absolute value of the electrical resistance caused by the environmental temperature. Therefore, the target value information stored in the target value storage unit 321 is changed by the target value changing unit 313 according to the deviation amount. The amount of change may be an amount that cancels out the amount of change in the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h that occurs according to the amount of deviation. Further, the target value information may be changed according to the deviation amount between the reference value and the actual measurement value of the deformation membrane resistance R _sns instead of the deviation amount between the reference value and the actual measurement value of the reference membrane resistance R _ref .

For this reason, the absolute value of the electrical resistance relating to at least one of the reference conductor portion 155s and the heater portion 155h at the time of shipment is stored as a reference value in the reference resistance storage portion 323, and the reference conductor portion 155s and the heater portion 155h Any configuration may be used as long as the absolute value of one of the electrical resistances stored in the reference resistance storage unit 323 is detected. In such a configuration, the amount of displacement of the lens group 20 due to the environmental temperature is indirectly detected according to the change in the absolute value of the electrical resistance related to at least one of the reference conductor portion 155s and the heater portion 155h. The target value information stored in the target value storage unit 321 may be changed so that the displacement amount is canceled out.

Further, instead of changing the target value information stored in the target value storage unit 321 by the target value changing unit 313, as shown in FIG. 34, a gain changing unit functionally realized in the focus control unit 310 By 314, the control parameter information stored in the gain storage unit 322 may be changed according to the change in the absolute value of the electrical resistance related to at least one of the reference conductor portion 155s and the heater portion 155h.

When such a configuration is adopted, the influence of the change due to the environmental temperature of the heater 155h on the displacement control in the actuator is suppressed.

In addition, when a thermometer for measuring the temperature of the

movable parts

15a and 15b is provided, and fluctuations in the absolute values of the electrical resistances of the reference conductor part 155s and the heater part 155h are monitored together with fluctuations in the temperature of the

movable parts

15a and 15b, Deterioration of the reference conductor portion 155s and the heater portion 155h is indirectly detected. In response to the occurrence of such deterioration, by changing at least one of the target value information stored in the target value storage unit 321 and the control parameter information stored in the gain storage unit 322, the heater unit 155h, etc. You may make it compensate the influence which deterioration of it has on the operation | movement of an actuator. When such a configuration is adopted, the influence of the deterioration of the heater portion 155h on the displacement control in the actuator is suppressed.

In the above-described embodiment, the variable resistor 330 is configured using a digital potentiometer. However, the present invention is not limited to this. For example, a mode using a manual trimmer resistor is also conceivable.

In the above-described embodiment, the

movable portions

15a and 15b are configured using so-called bimetals. However, the present invention is not limited to this. For example, the movable portion has a plate-like base portion (base portion) and a shape. A configuration having a portion (shape memory portion) provided in a thin film shape on the base portion using a shape memory material such as a memory alloy (SMA) may be employed. In such a configuration, for example, by directly applying a current that is electrical energy to the shape memory unit, the movable unit generates heat, and the shape memory unit is deformed in accordance with a temperature change, so that the driving force is increased. It is possible to generate and deform the movable part. And the shape memory | storage part can also be made to play a role as a deformation | transformation film | membrane.

In addition, the structure which gives a heat energy with the heater part provided separately with respect to a shape memory | storage part can also be considered.

In the above embodiment, the

movable parts

15a and 15b generate heat by applying electrical energy to the

movable parts

15a and 15b. However, the present invention is not limited to this. For example, the movable portion may be configured to include a portion that generates a driving force by applying at least one or more of various types of energy such as heat, voltage, current, light, and magnetism. .

In the above embodiment, the reference conductor portion 155s as the reference film and the heater portion 155h as the deformation film are both configured using the conductive material (conductor). However, the present invention is not limited to this. For example, the reference film may be either a conductor or a semiconductor. In addition, if a configuration in which the deformation film does not generate heat when energized is employed, the deformation film may be a semiconductor. That is, the reference film and the deformation film may be formed by the same process using at least one material of a conductor or a semiconductor and change in electrical resistance to some extent.

In the above embodiment, the feedback control of the displacement amount of the lens group 20 is _such that the ratio of the reference film resistance R _ref and the deformation film resistance R _sns is equivalent to the target value. It is not limited to this. For example, it may be assumed that there is a part having a component such as reactance or inductance related to a capacitor or coil in the circuit, so that the impedance ratio between the reference film and the deformation film is equivalent to the target value. Such control may be used. That is, the feedback control unit 312 determines the energy applied to the movable unit according to at least one of the impedance relationship between the reference membrane and the deformation membrane and the electrical information determined corresponding to the impedance relationship. The supply amount may be controlled.

In the embodiment described above, the displacement amount of the lens group 20 is controlled using the sense voltage V _sns and the _divided voltage V _vr , but the present invention is not limited to this. Directly after the electrical resistance of the reference conductor portion 155s and the heater portion 155h is detected and A / D conversion is performed, the ratio of the electrical resistance between the reference conductor portion 155s and the heater portion 155h is calculated, Feedback control may be performed so as to match the target value of the resistance ratio.

In the above embodiment, the formation of the metal thin film corresponding to the pattern of the heater layer 155 is realized by sputtering. However, the present invention is not limited to this. For example, any of a metal vapor deposition process, a metal plating process, a metal coating process, a bonding process of a metal thin film produced in a separate process, and a process of forming a thin film by rolling after a metal material is laminated and pasted These steps may be adopted. Regardless of which step is employed, the thickness and film quality of each part constituting the heater layer 155 are substantially the same.

In the above embodiment, the reference conductor portion 155s as the reference film and the heater portion 155h as the deformation film are formed at the same time using the same material in the same process. However, the present invention is not limited to this. For example, it is conceivable that the reference conductor portion 155s as the reference film and the heater portion 155h as the deformation film are formed sequentially in time by repeating the same process using the same material twice. The same process mentioned here includes, for example, sputtering under the same conditions using the same material. Different masks are used, and the reference conductor portion 155s as the reference film and the heater portion 155h as the deformation film are sequentially timed. A method such as forming in this way can be considered. However, from the viewpoint of the uniformity of the film thickness and film quality between the reference film and the deformation film, it is preferable to form them simultaneously.

In the above embodiment, the object moved by the

movable parts

15a and 15b (moving object) is the lens group 20 as an 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 20B corresponding to the optical system that guides light from the subject to the image sensor is fixed, and the image sensor layer is moved in the Z direction by a configuration similar to the configuration adopted for moving the lens group 20 in the one embodiment. It may be moved.

FIG. 35 is a diagram illustrating a conceptual diagram of one aspect in which the lens group 20B is fixed and the imaging element layer 18B is moved back and forth in a direction along the optical axis Ax of the lens group 20B. In FIG. 35, an imaging unit PBB that moves the imaging element layer 18B back and forth along the optical axis Ax is depicted. In such a configuration, the image pickup element layer 18B is moved back and forth along the optical axis Ax in accordance with the operation of the actuator layer, and the distance between the lens group 20B and the image pickup element layer 18B is changed. Is realized. Thus, AF control is realized if at least one of the image sensor and the optical system is moved in accordance with the displacement of the free end FT due to the bending deformation of the

movable portions

15a and 15b. In any configuration, the same effect as in the above-described embodiment can be obtained. For this reason, the distance between the image sensor and the optical system can be changed with high accuracy.

Further, an object (moving 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 drive device in which a moving object is moved according to deformation of the actuator. And according to such a drive device, the effect similar to the said one Embodiment is acquired.

In the above embodiment, the two

movable parts

15a and 15b are provided. However, the present invention is not limited to this, and the number of movable parts may be one or three or more.

In the above embodiment, the

movable parts

15a and 15b have a so-called cantilever structure in which one end is fixed to the frame 15f. However, the present invention is not limited to this. For example, what has what is called a doubly-supported beam structure in which both ends of the movable part are fixed to the frame is also conceivable.

◎ Needless to say, all or a part of the configuration of the above-described embodiment and various modifications can be combined as appropriate within a consistent range.

15,

15A Actuator layer

15a, 15b

Movable part

100, 100A Mobile phone 151 Low thermal expansion layer 152 Thermal conduction layer 153 High thermal expansion layer 154 Insulating

layer

155, 155A Heater layer 155h Heater part 155ha First heater part 155hb

Second heater part

155s, 155 sA Reference conductor 181 Image sensor 20 Lens group 310 Focus control unit 311 Resistance control unit 312 Feedback control unit 313 Target value change unit 314 Gain change unit 320 Storage unit 321 Target value storage unit 322 Gain storage unit 323 Reference resistance storage unit 330 variable resistor 500,500A camera module 600

current sources

703 and 704. resistor detector E1 ~ E3, EA1 ~ EA4 electrode portion FT free end R1, R2 dividing resistor value R _ref reference film resistor R _sns deformation film resistor V _ref reference Voltage V _sns sense voltage V _vr divided voltage

Claims

A reference section;
A movable part having a fixed part fixed to the reference part and having a displacement part that is displaced by deformation according to the application of energy;
With
The movable part is
It has a deformation film that is configured using at least one material of a conductor and a semiconductor and is deformed along with the deformation of the movable part,
The reference portion is
An actuator comprising a reference film formed in the same process using the same material as the deformation film.
The actuator according to claim 1,
A first terminal portion electrically connected to the deformation membrane and electrically connectable to an external element of the actuator;
A second terminal portion electrically connected to the reference film and electrically connectable to an external element of the actuator;
With
The actuator characterized in that the first and second element portions are provided in the reference portion.
The actuator according to claim 1,
The reference film and the deformation film are
An actuator formed simultaneously in the same step.
The actuator according to claim 1,
The reference film and the deformation film are
An actuator having the same thickness and the same crystal state.
The actuator according to claim 1,
The reference film and the deformation film are
It is contained in the integral film | membrane formed using the said same raw material, The actuator characterized by the above-mentioned.
The actuator according to claim 1,
The movable part is
An actuator having a base portion and a shape memory portion configured using a shape memory material, and deforming according to deformation of the shape memory portion according to a temperature change.
The actuator according to claim 1,
The deformation membrane is
An actuator characterized in that the movable part is deformed by generating a driving force in response to application of energy.
The actuator according to claim 1,
The movable part is
An actuator having a structure in which a plurality of layers including first and second layers having different coefficients of thermal expansion and the deformation film are stacked, and is deformed according to a temperature change.
The actuator according to claim 1,
The deformation membrane is
An actuator comprising a heater portion that generates heat in response to energization.
An actuator according to claim 1;
The supply amount of the energy applied to the movable part is controlled in accordance with at least one of the impedance relationship between the reference membrane and the deformable membrane and the electrical information determined corresponding to the impedance relationship. A control unit,
A drive device comprising:
The drive device according to claim 10,
The impedance relationship is
A driving apparatus comprising an impedance ratio between the reference film and the deformation film.
The drive device according to claim 11,
A target value storage unit that stores target value information in which a target value of a ratio of electrical resistance between the reference film and the deformation film is associated with each displacement amount of the displacement unit,
The control unit is
Feedback control is performed to adjust the supply amount of the energy applied to the movable portion so that the ratio of the electrical resistance matches the target value with respect to the target displacement amount of the displacement portion. To drive.
The drive device according to claim 12, wherein
A reference value storage unit that stores a reference value of electrical resistance according to at least one of the reference film and the deformation film;
A detection unit for detecting an actual electric resistance value according to at least one of the reference film and the deformation film in which a reference value of electric resistance is stored in the reference value storage unit;
A drive device further comprising:
The drive device according to claim 13,
An information changing unit that changes the target value information according to a deviation amount from a reference value of the electrical resistance to the actual electrical resistance value;
A drive device further comprising:
The drive device according to claim 13,
The relationship between the deviation | shift amount of the electric parameter | index determined with respect to the impedance relationship between the said reference | standard film | membrane and the said deformation | transformation film | membrane, the target value of this electric parameter | index, and the change amount of the said energy supply amount is shown. A control information storage unit for storing control parameter information;
An information changing unit that changes the control parameter information according to a deviation amount from a reference value of the electrical resistance to the actual electrical resistance value;
A drive device comprising:
The drive device according to claim 10,
The reference film and the deformation film are
A drive device that is electrically connected in series.
A drive device according to claim 10;
An image sensor;
An optical system for guiding light from a subject to the image sensor;
With
The movable part is
A camera module, wherein a distance between the image sensor and the optical system is changed by moving at least one of the image sensor and the optical system according to displacement of the displacement unit.