JP2008153881A - Camera module, and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module and an imaging apparatus capable of securing a magnetic shield while attaining miniaturization. <P>SOLUTION: A flexible substrate 6 provided with a terminal connection part 6b and a grounding potential terminal connection part 6c comprises a grounding potential pattern 6d (shown in the figure by a thick line) disposed including the grounding potential terminal connection part 6c, and a base attaching part 6e disposed so as to surround the periphery of the terminal connection part 6b and the grounding potential terminal connection part 6c, to which the end face of a base is attached. The base attaching part 6e is provided with a soldering region 6f (shown in the figure by diagonal lines) where the end face of the base is soldered and an adhesion region 6g (shown in the figure by dashed lines) where the end face of the base is adhered with a non-conductive adhesive. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a camera module and an imaging device mounted on, for example, a mobile phone.

In recent years, camera systems have been mounted on mobile phones and the like. In such a camera system, a camera module that forms a subject image on an image sensor using a microlens is widely used.
As mobile phones and the like are miniaturized, further miniaturization of camera modules is required.

As a technique related to a camera module that achieves downsizing and high focus accuracy, a technique corresponding to Patent Document 1 has been conventionally known.
Patent Document 1 discloses that “a lens, a lens barrel that supports the lens, an image sensor chip that captures an image by a sensor unit based on light incident through the lens, and outputs an imaging signal; and a wiring having a window unit. Here, the lens barrel is fixed on the surface of the wiring board, and the image sensor chip has the lens barrel of the wiring board so that the sensor portion is positioned at the window portion of the wiring board. Is fixed on the surface opposite to the fixed surface. "The technique is disclosed.

JP 2003-51973 A

  Here, in a mobile phone equipped with a camera module, electrical noise generated inside the camera module adversely affects other electrical devices, or electrical noise is input from other electrical devices to the camera module. Conventionally, a technique related to a magnetic shield for preventing such a situation has been proposed. However, it has been difficult to achieve both the miniaturization of the camera module and the securing of the magnetic shield even when the conventionally proposed technology is used.

  The present invention has been made in order to solve the technical problems as described above, and an object of the present invention is to provide a camera module and an imaging apparatus capable of securing a magnetic shield while realizing miniaturization. It is to provide.

  For this purpose, the camera module to which the present invention is applied has a conductive pedestal that covers at least the image sensor, an optical member disposed in a light incident path to the image sensor, and a ground potential pattern. And a substrate having an attachment region to which the pedestal is attached, wherein the ground potential pattern crosses the attachment region.

  Here, the portion of the ground potential pattern crossing the attachment region may be a portion where the pedestal is soldered to the substrate. In the attachment region, a non-conductive adhesive may be used except for a portion where the ground potential pattern crosses.

  From another viewpoint, the camera module to which the present invention is applied has conductivity, a pedestal that covers at least the image sensor, an optical member that is disposed in a light incident path to the image sensor, and the pedestal A substrate having an attachment region to be attached, a plurality of terminals electrically connected to the imaging device, and a ground potential pattern electrically connected to a part of the plurality of terminals; The mounting region includes a first region electrically connected to the ground potential pattern and a second region electrically unconnected to the ground potential pattern.

  In the first region, the pedestal may be soldered to the substrate. In the second region, the pedestal may be fixed to the substrate with a non-conductive adhesive.

  Further, from another viewpoint, the imaging apparatus to which the present invention is applied includes an imaging element that converts incident light into an electrical signal and outputs the cover, and a cover that transmits light to the imaging element as the incident light. A member, a substrate that holds the imaging element and the cover member, receives the electrical signal output from the imaging element, and has a ground potential pattern; a lens that focuses the incident light on the imaging element; A pedestal holding a lens and having a side wall attached to the substrate; and a signal processing unit connected to the substrate and processing the electrical signal output from the substrate, wherein the ground potential pattern includes The mounting area of the board to which the side wall of the pedestal is mounted is traversed.

  According to the present invention, both miniaturization and securing of a magnetic shield can be achieved.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is an external perspective view showing a camera module 1 according to the present embodiment, and FIG. 2 is an exploded perspective view of the camera module 1 according to the present embodiment.
As shown in FIGS. 1 and 2, the camera module 1 includes a lens unit (optical component) 2, a pedestal (pedestal mount) 3 that holds the lens unit 2, and a pedestal 3. A filter (optical component) 4 that transmits light, a sensor (imaging device) 5 that receives light transmitted through the filter 4 and performs photoelectric conversion, a flexible substrate (FPC: Flexible Printed Circuit, circuit substrate) 6 to which the base 3 is attached, A plate-like glass cover (cover member) 7 (see FIG. 3) for attaching the sensor 5 to the base 3 is provided. A part formed by attaching the lens unit 2 to the pedestal 3 may be referred to as a lens barrel. Further, the state in which the flexible substrate 6 is not included may be referred to as the camera module 1.

The pedestal 3 is configured integrally with a cylindrical portion 3 a to which the lens unit 2 is attached and a rectangular portion 3 b having a space for accommodating and holding the filter 4 and the sensor 5 therein. The base 3 is configured such that the internal space of the cylindrical portion 3a and the internal space of the rectangular portion 3b are continuous. The pedestal 3 has a flange portion 3d (see FIG. 3) formed so as to extend from the inner surface and narrow the internal space.
On the inner peripheral surface of the cylindrical portion 3a of the pedestal 3, a female female 3c is formed. A male screw 2 c corresponding to the female female 3 c is formed on the outer peripheral surface of the lens unit 2. As will be described later, the lens unit 2 is attached to the cylindrical portion 3a of the pedestal 3 by screwing. More specifically, an end face (side wall part) 3e opposite to the cylindrical part 3a in the rectangular part 3b of the base 3 is fixed to the flexible substrate 6 with a predetermined adhesive or the like.

  Here, the base 3 is formed so as to have conductivity. That is, the pedestal 3 is manufactured with a conductive material, or is formed with a conductive film on the surface after being formed with a non-conductive material. For example, the pedestal 3 is made of non-conductive resin such as ABS (acrylonitrile butadiene styrene), nylon, PPS (polyphenylene sulfide), polycarbonate, noryl and liquid crystal polymer, and carbon, Al and magnesium as conductive materials. It is possible to use a conductive resin mixed with the above metal filler. In particular, by mixing carbon into the resin, it is conceivable that the pedestal 3 is made conductive and the pedestal 3 is blackened so that light is not reflected. It is also conceivable to lower the resistivity by evaporating a metal film such as Al on the resin surface or performing a plating treatment. Furthermore, it is also conceivable to use a combination of a conductive resin and a vapor deposition film or a plating film. The plating film or the vapor deposition film may be formed only on the surface (outer surface) or the inner surface of the pedestal 3, but it may be formed on both the inner surface and the outer surface.

FIG. 3 is a longitudinal sectional view of the camera module 1 according to the present embodiment.
As shown in FIG. 3, the lens unit 2 includes a barrel (holder) 2a of the lens unit main body and a lens 2b held by the barrel 2a. An opening 2d is formed on the end surface of the barrel 2a. The lens 2 b is an optical element for condensing external light on the light receiving region of the sensor 5. In other words, the lens 2 b forms a predetermined optical system so that light (optical image) from the opening 2 d forms an image and enters the sensor 5. The lens 2b can be composed of a single lens or a plurality of lens groups.

Here, the barrel 2a of the lens unit 2 is made of a metal tube such as conductive resin or stainless steel. The lens 2b has a surface that is made conductive by providing a transparent conductive thin film. As such a transparent conductive thin film, ITO, tin oxide (SiO ₂ ), zinc oxide (ZnO) film or the like can be used. These transparent conductive thin films can be formed on the surface of the lens 2b by a coating method, a sputtering method, or the like.

  The filter 4 is a film-like member that removes a specific frequency component of external light. In the present embodiment, an infrared ray removal filter (IRCF: Infrared Cut Filter) made of a conductive material is used. The filter 4 is attached to the flange portion 3d with a conductive adhesive. When the filter 4 is attached to the flange portion 3d, the internal space of the base 3 is divided into two. The filter 4 is disposed in the vicinity of the sensor 5, thereby suppressing the influence of irregular reflection.

  The sensor 5 is an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). In the present embodiment, a sensor having a CSP (Chip Scale Package) structure is used. The sensor 5 generates and outputs a signal according to light incident on the light receiving region via the lens unit 2.

The flexible substrate 6 is a circuit substrate having flexibility, flexibility, and space saving. Generally, a circuit is formed on a polyester (PET) film by printing or etching. And the base 3 is arrange | positioned at the one end part of the flexible substrate 6, and the connector 6a (refer FIG. 1 or FIG. 2) is arrange | positioned at the other end part of the flexible substrate 6. FIG. The connector 6a is connected to the sensor 5 by the flexible substrate 6 and has a function of electrically connecting to an external device (not shown). In addition, in order to increase the strength of the flexible substrate 6 having flexibility, a reinforcing plate (not shown) can be fixed to the position corresponding to the base 3 of the flexible substrate 6 with an adhesive.
In addition, the flexible substrate 6 has a terminal connection part (terminal) 6b and a ground potential terminal connection part (terminal) 6c (see FIG. 4) on the front side (pedestal mounting side). In other words, the connection terminal portion 6 b extends to the back side of the flexible substrate 6 using, for example, a through hole or the like and is electrically connected to a connector 6 a located outside the pedestal 3. The ground potential terminal connection 6c (see FIG. 4) is connected to a ground potential pattern 6d that extends from the inside of the base 3 to the outside of the base 3.

  The glass cover 7 is a plate-like member for attaching the sensor 5 to the pedestal 3, and is disposed between the filter 4 and the sensor 5. The glass cover 7 is fixed to the inner peripheral surface of the base 3 with a predetermined adhesive.

More specifically, the sensor 5 is attached to the glass cover 7. That is, a wiring pattern is provided in advance on the emission surface (lower surface in FIG. 3) side of the glass cover 7. A plurality of solder bumps 8 are positioned so as to connect the electrodes of the wiring pattern and the sensor 5. Thus, the sensor 5 is fixed to the glass cover 7 and electrically connected to the electrodes of the glass cover 7 by the solder bumps 8 attached to the positions of the electrodes.
Further, solder bumps 9 are arranged at other positions of the electrodes on the light exit surface side of the glass cover 7. By attaching the solder bumps 9 to the terminal connection portions 6 b of the flexible substrate 6, when the glass cover 7 is solder-mounted on the flexible substrate 6, electrical connection between the glass cover 7 and the flexible substrate 6 is ensured. Is done.

In the camera module 1 configured as described above, light that enters the camera module 1 from the opening 2d of the lens unit 2 is refracted by the lens 2b and then passes through the through hole 3i and passes through the filter 4. Then, when the light passes through the filter 4, a predetermined infrared ray is removed from the light, passes through the glass cover 7, forms an image on the light receiving region of the sensor 5, and enters. In addition, the filter 4 is arrange | positioned in the vicinity of the sensor 5, and, thereby, suppresses the influence of irregular reflection.
Then, a signal is generated according to the light incident on the light receiving area in the sensor 5 and output to the outside. A signal output from the sensor 5 is sent to the glass cover 7 via the solder bumps 8, and is input from the wiring pattern of the glass cover 7 to the flexible substrate 6 via the solder bumps 9. The connector 6a (see FIG. 1 or FIG. 2), for example, to a mobile device equipped with the camera module 1. The operation of the mobile device equipped with the camera module 1 will be described later.

  In the camera module 1, the barrel 2a, the lens 2b, and the pedestal 3 are all made conductive. For this reason, the barrel 2a and the lens 2b constituting the lens unit 2 are electrically connected to each other, and the lens unit 2 and the pedestal 3 are also electrically connected to each other. When the pedestal 3 is attached to the flexible substrate 6, the pedestal 3 is electrically connected to the ground potential terminal connection portion 6 c (see FIG. 4) and the ground potential pattern 6 d of the flexible substrate 6. Thereby, the camera module 1 is shielded electromagnetically. For this reason, the electrical noise (electromagnetic wave noise) generated in the camera module 1 is blocked from entering other electrical devices, and the electrical noise is blocked from entering the camera module 1 from the outside. Therefore, it is possible to prevent the external electrical noise from affecting the photographed image and the like, and the electrical noise of the camera module 1 from affecting other electrical devices.

FIG. 4 is a plan view showing a portion of the flexible substrate 6 to which the base 3 is attached.
As shown in FIG. 4, the flexible substrate 6 is soldered with solder bumps 9 to enable transmission and reception of a predetermined signal between the sensor 5 and the connector 6 a of the flexible substrate 6 (see FIG. 1 or FIG. 2). A terminal connection 6b is provided. In addition, the flexible substrate 6 has a ground potential terminal connection portion 6c for soldering solder bumps 9 and grounding the sensor 5 and the like.

  Further, the flexible substrate 6 is disposed so as to surround the ground potential pattern 6d including the ground potential terminal connection portion 6c and the terminal connection portion 6b and the ground potential terminal connection portion 6c, and the end surface 3e of the base 3 is disposed. And a pedestal attachment portion (attachment region) 6e to which (see FIG. 3) is attached. The ground potential pattern 6d is shown by a bold line.

Here, the pedestal mounting portion 6e has a non-conductive adhesion between the soldering region (first region) 6f to which the end surface 3e (see FIG. 3) of the pedestal 3 is soldered and the end surface 3e (see FIG. 3) of the pedestal 3 And 6 g of a bonding area (second area) bonded with an agent. Note that the soldering region 6f is illustrated with diagonal lines, and the bonding region 6g is illustrated with one-dot chain lines.
More specifically, the ground potential pattern 6d extends outside the pedestal mounting portion 6e from a range surrounded by the pedestal mounting portion 6e. That is, the ground potential pattern 6d is arranged so as to cross (cross) the base attaching portion 6e. And the part which overlaps with the grounding potential pattern 6d among the base attachment parts 6e is the soldering area | region 6f.

Here, the comparative example about this Embodiment is demonstrated. FIG. 5 is a plan view for explaining the flexible substrate 60 of the comparative example. FIG. 5 corresponds to FIG. 4 showing the flexible substrate 6 of the present embodiment.
As shown in FIG. 5, the flexible substrate 60 has a terminal connection portion 6 b and a ground potential terminal connection portion 6 c, similarly to the flexible substrate 6. Further, the flexible substrate 60 is disposed so as to surround the terminal connection portion 6b and the ground potential terminal connection portion 6c, and has a pedestal attachment portion 60e to which the end surface 3e (see FIG. 3) of the pedestal 3 is attached by soldering. In addition, the flexible substrate 60 has a ground potential pattern 60d disposed so as to include the pedestal mounting portion 60e. The ground potential pattern 60d is arranged including the ground potential terminal connection portion 6c. The ground potential pattern 60d is illustrated by a thick line, and the pedestal mounting portion 60e is illustrated by a broken line.

In the flexible substrate 60 of the comparative example, the ground potential pattern 60d is adjacent to all the terminal connection portions 6b. Therefore, it is necessary to take care not to touch during assembly, and it is difficult to improve workability. Therefore, in order to improve the workability, it is necessary to increase the distance between the ground potential pattern 60d and the terminal connection portion 6b. As a result, it becomes difficult to realize downsizing, and the mounting area of the camera module is reduced. Becomes larger.
On the other hand, in the flexible substrate 6 of the present embodiment, the ground potential pattern 6d is arranged avoiding the vicinity of the terminal connection portion 6b which is a connection portion other than the ground potential terminal connection portion 6c. For this reason, some of the terminal connection portions 6b are not adjacent to the ground potential pattern 6d, so that the workability at the time of assembly can be improved without increasing the distance between the terminal connection portion 6b and the ground potential pattern 6d. This can be improved compared to the comparative example. Therefore, the assembly workability can be improved while reducing the mounting area due to the miniaturization of the camera module 1.

FIG. 6 is a diagram for explaining an assembly procedure of the camera module 1.
As shown in FIG. 6, first, the lens unit 2 and the filter 4 are attached to the pedestal 3, and the glass cover 7 with the sensor 5 is attached with an adhesive. Solder bumps 9 are attached to the glass cover 7.
Further, a non-conductive adhesive is applied to the end surface 3e (see FIG. 3) of the base 3. More specifically, a non-conductive adhesive is not applied to the entire end surface 3e (see FIG. 3) of the pedestal 3, but a soldering region 6f (see FIG. 4) of the flexible substrate 6 in the end surface 3e (see FIG. 3). The non-conductive adhesive is not applied to the portion corresponding to (). In other words, the non-conductive adhesive is applied to the end face 3e (see FIG. 3) except for the portion corresponding to the soldering region 6f (see FIG. 4) of the flexible substrate 6. As this non-conductive adhesive, one having heat resistance and thermosetting is used.

  The pedestal 3 thus assembled is placed on the flexible substrate 6. In this case, a portion of the end surface 3e (see FIG. 3) of the base 3 to which the non-conductive adhesive is applied is placed on the adhesion region 6g (see FIG. 4) of the flexible substrate 6. In other words, a portion of the end surface 3e (see FIG. 3) of the pedestal 3 where the non-conductive adhesive is applied is prevented from being placed on the soldering region 6f of the flexible substrate 6.

  Then, it is put in a reflow furnace and soldered. That is, each of the solder bumps 9 is soldered to the terminal connection portion 6b or the ground potential terminal connection portion 6c of the flexible substrate 6. As a result, the electrical signal photoelectrically converted by the sensor 5 is input to the flexible substrate 6. The pedestal 3 is electrically connected to the flexible substrate 6 through the soldering region 6f. As described above, the pedestal 3 is also electrically connected to the barrel 2a and the lens 2b. For this reason, the entire camera module 1 is magnetically shielded, and adverse effects due to electrical noise can be prevented.

Next, a mobile phone 100 as an imaging device including the camera module 1 of the present embodiment will be described. In addition to the mobile phone 100, the camera module 1 according to the present embodiment is applied to, for example, a camera mounted on a personal computer or a PDA (Personal Digital Assistant), a camera mounted on a car, a surveillance camera, or the like. It is possible.
FIG. 7 is a block diagram showing a configuration of the mobile phone 100. As illustrated in FIG. 7, the mobile phone 100 performs an image processor (ISP) 101 as an example of a signal processing unit that performs image processing on an image signal from the camera module 1 and various controls in the mobile phone 100. An MPU (Micro Processing Unit) 102 and an input key 103 for giving an instruction from the user to the MPU 102 are provided. The mobile phone 100 displays, for example, a telephone number at the time of outgoing and incoming calls, a remaining battery level, a radio wave reception state, and the like, and a liquid crystal display as an example of an image output unit that displays a subject photographed by the camera module 1. (LCD) 104 is provided. The mobile phone 100 includes a memory 105 that stores various information for controlling the mobile phone 100 and a memory card 106 as an example of a recording medium that records image data.
Furthermore, the mobile phone 100 receives radio waves in a mobile phone band or a wireless local area network (LAN) band via an antenna 107 and performs radio communication with a server provided by a mobile phone carrier or the like. Unit 108, baseband unit 109 that generates a signal for communication, audio codec unit 110 that reproduces sound such as voice during a call and ringing melody, and ringing sound based on a signal from audio codec unit 110 Is provided, and an LED 112 is provided to notify the incoming call by light.
Further, the camera module 1 communicates with the MPU 102 through an interface such as IIC or SPI, and transmits and receives signals.

  In the mobile phone 100, when the digital camera use mode is selected with the input key 103, the MPU 102 starts communication with the camera module 1. Then, the MPU 102 transmits a control signal to the camera module 1. Then, the light from the subject that has passed through the lens unit 2 of the camera module 1 is converted into an electrical signal by the sensor 5 of the camera module 1, and signal processing is performed by the ISP 101. The image signal processed by the ISP 101 is temporarily stored in the memory 105 of the mobile phone 100 and displayed on the LCD 104 as a through image.

By the way, the photographing of the subject is performed by the shutter button on the input key 103. When the shutter button is pressed, the MPU 102 stores the image data processed by the ISP 101 in the memory 105. The MPU 102 includes a compression / decompression circuit using a technique such as JPEG or MPEG, and the image data stored in the memory 105 is compressed by the MPU 102 and recorded on the memory card 106. Further, the image data recorded on the memory card 106 can be decompressed by the MPU 102, read into the memory 105, and displayed again on the LCD 104.
Note that the MPU 102 can select a shooting mode and set white balance, exposure, sensitivity, and the like by an operation from the input key 103. Further, when the image data processed by the ISP 101 is stored in the memory 105, digital zoom processing can be performed.

It is an external appearance perspective view which shows the camera module which concerns on this Embodiment. It is a disassembled perspective view of the camera module which concerns on this Embodiment. It is a longitudinal cross-sectional view of the camera module which concerns on this Embodiment. It is a top view which shows the part of the flexible substrate to which a base is attached. It is a top view for demonstrating the flexible substrate of a comparative example. It is a figure for demonstrating the assembly procedure of a camera module. It is a block diagram which shows the structure of a mobile telephone.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Camera module, 2 ... Lens unit, 3 ... Base, 4 ... Filter, 5 ... Sensor, 6 ... Flexible substrate, 6a ... Connector, 6b ... Terminal connection part, 6c ... Ground potential terminal connection part, 6d ... Ground potential pattern , 6e ... pedestal mounting portion, 6f ... soldering area, 6g ... adhesion area, 7 ... glass cover, 100 ... mobile phone

Claims (7)

A pedestal having conductivity and covering at least the image sensor;
An optical member disposed in a light incident path to the image sensor;
A substrate having a ground potential pattern and having an attachment region to which the pedestal is attached;
Including
The camera module according to claim 1, wherein the ground potential pattern crosses the attachment region.   2. The camera module according to claim 1, wherein a portion of the ground potential pattern crossing the attachment region is a portion where the pedestal is soldered to the substrate.   2. The camera module according to claim 1, wherein a non-conductive adhesive is used in the attachment region except a portion where the ground potential pattern crosses. A pedestal having conductivity and covering at least the image sensor;
An optical member disposed in a light incident path to the image sensor;
A substrate having an attachment region to which the pedestal is attached, a plurality of terminals electrically connected to the imaging device, and a ground potential pattern electrically connected to a part of the plurality of terminals When,
Including
The camera module according to claim 1, wherein the attachment region includes a first region electrically connected to the ground potential pattern and a second region electrically unconnected to the ground potential pattern.   The camera module according to claim 4, wherein the pedestal is soldered to the substrate in the first region.   The camera module according to claim 4, wherein in the second region, the pedestal is fixed to the substrate with a non-conductive adhesive. An image sensor that converts incident light into an electrical signal and outputs the electrical signal;
A cover member that transmits light to the image sensor as the incident light;
A substrate that holds the image sensor and the cover member, receives the electrical signal output by the image sensor, and has a ground potential pattern;
A lens that focuses the incident light on the imaging device;
A pedestal holding the lens and having a side wall attached to the substrate;
A signal processing unit connected to the substrate and processing the electrical signal output from the substrate;
Including
2. The imaging apparatus according to claim 1, wherein the ground potential pattern traverses an attachment region of the substrate to which the side wall portion of the pedestal is attached.

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