JP2009182381A - Imaging module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging module in which electromagnetic radiation noise to an imaging device is satisfactorily shut off and whose productivity is high. <P>SOLUTION: The imaging module 1 includes: an imaging substrate 2 on which an imaging device 2a for converting light into an electric signal is mounted: a lens member 3 which supports a lens 3a for condensing subject light on the imaging device 2a, by a holder 3b; a plurality of support pins 4 which have one sides 4a attached to the holder 3b and penetrate the imaging substrate 2 and support the imaging device 2a in such a state that the imaging device 2a overlaps the lens member 3 with a prescribed gap between them, while holding the imaging substrate 2 by pressing parts 4b on the other sides; and a shield member 5 which has elasticity and is disposed between the imaging substrate 2 and the holder 3b so as to surround the imaging element 2a and presses the imaging substrate 2 toward the pressing parts 4b. Since the imaging substrate 2 is held and fixed by elasticity of the shield member 5 and by pressing the imaging substrate 2 by the pressing parts 4b of the support pins 4, attachment of the shield member 5 and alignment of the imaging substrate 2 are facilitated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an imaging module such as a camera module.

  As a small image pickup module using an image sensor such as a CCD as an image pickup device, a shield member is disposed around the image pickup device, and the image pickup substrate and the shield member are attached to the lens member by a plurality of support pins. Modules are known (see, for example, Patent Document 1).

Such a camera module collects light from a subject on an image pickup device by an optical lens and converts the light into an electric signal to obtain an image. The shield member is an electromagnetic radiation noise generated by an image sensor used as the image pickup device. Is provided for the purpose of blocking electromagnetic radiation noise in order to reduce the noise of the electric signal generated by. The support pin fixes the imaging board to the lens member, and adjusts the distance between the imaging element and the lens member and the angle between the lens and the imaging board when the imaging board is attached to the lens member. Thus, it has a function of aligning the imaging substrate.
JP 2007-28430

  However, in the conventional imaging module, when the imaging board and the support pin are aligned, for example, the imaging board is moved while holding the imaging board with a separately prepared jig or the like, and the position of the imaging board is adjusted. After it has been determined, it is necessary to fix it to the support pin using a connecting material such as solder, which causes a problem that the assembly of the imaging module becomes complicated.

  In addition, the shield member arranged between the imaging board and the holder makes it difficult to hold the imaging board, and the structure of jigs and equipment used for alignment between the imaging board and the support pins is complicated. was there.

  The present invention has been devised to solve these problems in the prior art, and an object of the present invention is to provide an imaging module that is excellent in blocking electromagnetic radiation noise on the imaging substrate and has high productivity. is there.

  An imaging module according to the present invention includes an imaging board on which an imaging device that converts light into an electrical signal is mounted, a lens member that supports a lens that focuses subject light on the imaging device with a holder, and one side of the lens member. A plurality of attachments that are attached to the holder and that pass through the imaging substrate and are held by the other pressing portion while supporting the imaging element in a state of being overlapped with the lens member while maintaining a predetermined gap. A support pin and an elastic shield member disposed between the imaging substrate and the holder so as to surround the imaging element and pressing the imaging substrate toward the pressing portion are provided. Is.

  In the imaging module of the present invention, in the above configuration, the shield member is preferably a metal plate in which a curved portion is provided between the imaging substrate and the holder.

  According to the imaging module of the present invention, an imaging board on which an imaging element that converts light into an electrical signal is mounted, a lens member that supports a lens that focuses subject light on the imaging element, and a lens member on one side. A plurality of support pins that are attached to the holder and pass through the imaging substrate and held by the other side pressing portion, and support the imaging element in a state of being superposed while maintaining a predetermined gap with respect to the lens member; The image pickup board has elasticity and is arranged so as to surround the image pickup device between the image pickup board and the holder and presses the image pickup board toward the pressing portion. Therefore, the image pickup board uses the elasticity of the shield member. The support pin is pushed into the holder with the arrangement in which one main surface of the image sensor is pressed, and the image pickup substrate is moved by adjusting the force to press the other main surface of the image pickup substrate by the holding portion of the support pin. When the position of the image pickup board is determined, the movement of the support pin is stopped, and the other main surface of the image pickup board is pressed by the holding portion of the support pin while pressing the one main face of the image pickup board by the elasticity of the shield member. Since the image pickup board can be held and fixed at a desired position in the adjustment range, it is possible to easily attach the shield member and align the image pickup board in the assembly of the camera module. The imaging module has a good interception of electromagnetic radiation noise and high productivity.

  Further, according to the imaging module of the present invention, when the shield member is a metal plate provided with a curved portion between the imaging substrate and the holder, the imaging substrate is moved by the shielding member even if the area where the shielding member is arranged is small. Since a sufficient pressing force can be obtained, the imaging module can be reduced in size. Then, while pressing one main surface of the imaging substrate by the elasticity of the shield member made of a metal plate provided with the curved portion, the other main surface of the imaging substrate is pressed by the pressing portion of the support pin. Since it can be held and fixed, it is possible to easily attach the shield member and align the imaging substrate in the assembly of the imaging module.

  Hereinafter, an imaging module of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the subject side of the imaging module is called the front side, and the opposite side is called the back side.

  FIG. 1 is a cross-sectional view of a camera module which is an example of an embodiment of an imaging module of the present invention. The camera module 1 shown in the figure has an imaging substrate 2, a lens member 3, a support pin 4, and a shield member 5 as a basic configuration.

  Such a camera module 1 is, for example, a camera module 1 used for in-vehicle use, and has a function of imaging a white line on a road or imaging a blind spot of a driver who drives a vehicle, and controls driving of the automobile. The operation is controlled by an ECU (Electronic Control Unit) (not shown). The electrical signal output from the camera module 1 is converted into an image signal by the ECU and displayed on a display (not shown) installed in front of the driver's seat, for example.

  The imaging substrate 2 is a substrate on which an imaging element 2a for converting light into an electrical signal is mounted on one main surface. For example, a glass cloth is impregnated with an epoxy resin, or a glass filler is added to the epoxy resin. It is comprised by the printed wiring board formed in this way.

  The image pickup device 2a mounted on the image pickup substrate 2 is a semiconductor image sensor device such as a CCD image sensor or a CMOS image sensor, and is usually housed in the sub-board 2b. The sub board 2b is made of, for example, a ceramic wiring board mainly composed of alumina, and has a function of housing the image pickup element 2a in a cavity 2c formed on the subject side. The cavity 2c is sealed with a light-transmitting lid 2d such as glass. A plurality of terminals (not shown) extend from the sub-board 2b and are fixed to the imaging board 2 with a bonding material such as solder. The imaging element 2a and a wiring conductor described later of the imaging substrate 2 are electrically connected by a terminal, and the sub-substrate 2b is fixed and supported on the imaging substrate 2. Note that the amount of glass cloth or glass filler used for the imaging substrate 2 is preferably set so that the thermal expansion coefficient of the sub-substrate 2 b is equal to the thermal expansion coefficient of the imaging substrate 2.

  In addition, on the surface or inside of the imaging board 2, electrical connection with terminals of the sub-board 2b and terminals of other components to be mounted, wiring conductors (not shown) for fixing them, and ground wirings (not shown) (Shown) is formed. For such wiring conductors and ground wirings, a method of forming a conductive metal such as copper or gold by a plating method, a method of bonding a metal foil previously formed in a wiring pattern shape, or a metal foil is deposited on the entire surface It is formed on the surface of the printed wiring board or inside by using a method of etching away unnecessary portions from the substrate by etching.

  Such an imaging substrate 2 is prepared, for example, by preparing a commercially available copper-clad substrate with a copper foil applied to the entire front and back surfaces, cutting the substrate into a desired size, and applying the copper foil applied to the surface to dilute hydrochloric acid or the like. It is manufactured by etching a desired wiring pattern with an acidic solution. If necessary, a through hole is formed using a laser or a drill, and the through hole is filled with a metal paste to embed the through conductor, thereby electrically connecting the wiring patterns on the front and back of the board. Is possible.

  On the other main surface on the opposite side of the image pickup substrate 2 where the image pickup device 2a is disposed, an IC 6 for processing an electric signal from the image pickup device 2a, a wiring conductor of the image pickup substrate 2 and an ECU (not shown) are electrically connected. Components such as a connector 7 for connecting a cable (not shown) to be connected to are mounted.

  The lens member 3 is a lens 3a that condenses subject light on the image sensor 2a and is supported by a holder 3b. The lens 3a has a function of condensing light from the subject on the image sensor 2a, and normally, a first lens 31 having a convex shape on the subject side in order to collect light at a wide angle, and a first lens The lens group is composed of a second lens 32 and a third lens 33 for bringing the light passing through 31 close to parallel as a light beam. When the lens 3a is composed of the above three lenses, for example, the first lens 31, the second lens 32, and the third lens 33 are arranged so as to overlap in this order from the subject side.

  In this example, the holder 3b includes a retainer 34 as a pressing jig disposed on the subject side, and a barrel 35 as a lens holder disposed on the imaging element 2a side. The second lens 32 and the third lens 33 are fixed to the barrel 35 of the holder 3b, and the first lens 31 is fixed to the barrel 35 by the retainer 34.

  The retainer 34 and the barrel 35 are produced by the following method, for example.

  The barrel 35 has a predetermined shape by preparing a mold for injection molding having a cavity provided in accordance with the shape of the barrel 35, pouring the raw material for the barrel 35 into the cavity, solidifying and molding. It can produce using the conventionally well-known injection molding method formed in this. Similarly, the retainer 34 is formed by preparing a mold for injection molding having a cavity formed in a shape corresponding to the shape of the retainer 34, and pouring the raw material for the retainer 34 into the cavity and solidifying it. By doing so, it can be formed in a predetermined shape. Such a retainer 34 and barrel 35 are made of a non-conductive resin such as polycarbonate (PC) or polyphthalamide (PPA), for example, and are reduced in weight. Normally, in order to match the thermal expansion and thermal contraction of the retainer 34 and the barrel 35, it is preferable to use the same material for both.

  Such a lens member 3 and the imaging substrate 2 are fixed to each other by a plurality of support pins 4. In the camera module 1 of this example, one side 4a of the support pin 4 is attached to the back side of the holder 3b of the lens member 3, and passes through the imaging substrate 2 and is held by the other side pressing portion 4b while taking an image. The imaging substrate 2 on which the element 2a is mounted is supported in a state where it is overlapped with the lens member 3 while maintaining a predetermined gap. The plurality of support pins 4 are preferably three or more from the viewpoint of stably fixing the imaging substrate 2. For example, in the camera module 1 of the present example, although not shown in the drawing, a rectangular imaging is provided. The substrate 2 is used, and four support pins 4 are used for this, and the support pins 4 are attached in the vicinity of the four corners of the imaging substrate 2, respectively. When a different type of lens 3a is used by supporting a plurality of support pins 4 in a state where the imaging substrate 2 on which the imaging element 2a is mounted is superposed on the lens member 3 while maintaining a predetermined gap. Even if the focal position of the lens 3a moves, the imaging element 2a can be easily moved to the focal position of the lens 3a by changing the distance of the gap between the imaging substrate 2 and the lens member 3 using the support pins 4. It is possible to hold it.

  The support pin 4 is formed in a substantially rod shape using a highly conductive metal having excellent rust prevention properties such as an iron-chromium-nickel alloy, and one side 4a attached to the holder 3b is For example, it is formed in a rod shape having a diameter of 0.4 to 1.5 mm. The imaging board 2 is provided with a plurality of through holes through which one side 4a of the support pin 4 can be passed. In addition, the pressing portion 4b provided on the other side of the support pin 4 is set to a diameter that cannot pass through the through hole of the imaging substrate 2 through which the one side 4a of the support pin 4 has penetrated. The imaging substrate 2 is pressed against the other principal surface in the vicinity. For example, if the diameter of the through hole is 1.2 mm, the diameter of the pressing portion 4b may be set to 1.5 to 3.0 mm. A ground potential electrode (not shown) is provided around the plurality of through-holes on the other main surface of the imaging substrate 2, and the support pin 4 has a pressing portion 4 b with the ground potential electrode. Is in contact with the ground wiring of the image pickup substrate 2.

  In the camera module 1 of this example, the elastic shield member 5 is disposed between the imaging substrate 2 and the holder 3b so as to surround the imaging element 2a, and presses the imaging substrate 2 toward the pressing portion 4b. is doing.

  With such a configuration, the support pin 4 is pushed into the holder 3b with one main surface of the imaging substrate 2 being pressed using the elasticity of the shield member 5, and the support pin 4 The force that presses the other main surface of the imaging board 2 by the pressing portion 4b is adjusted to move the imaging board 2. When the position of the imaging board 2 is determined, the movement of the support pins 4 is stopped, and the elasticity of the shield member 5 is increased. By pressing the other main surface of the imaging substrate 2 with the pressing portion 4b of the support pin 4 while pressing one main surface of the imaging substrate 2, the imaging substrate 2 is held at a desired position in the adjustment range. Since it can be fixed, it is possible to easily attach the shield member 5 and align the image pickup substrate 2 in the assembly of the camera module 1, and the electromagnetic radiation noise with respect to the image pickup element 2a is well blocked. And it can have high productivity camera module 1.

  Such a shield member 5 is disposed so as to surround the image sensor 2a and has a function of blocking electromagnetic radiation noise that enters the image sensor 2a from the surroundings, such as a copper-nickel-zinc alloy or aluminum. The plate material made of a highly conductive metal material can be cut into a predetermined shape and formed into a shape having elasticity. Further, in the camera module 1 of this example, the shield member 5 is a metal plate provided with a curved portion between the imaging substrate 2 and the holder 3b, or the shield member 5 is shielded even if the area where the shield member 5 is disposed is small. Since sufficient force to press the imaging substrate 2 by the member 5 can be obtained, the camera module 1 can be downsized. If the shield member 5 has a substantially semicircular cross section, the shield member 5 can be lightened while ensuring the desired elasticity, and thus the weight of the camera module 1 can be reduced.

For example, using copper-nickel-zinc alloy, if the plate thickness is in the range of 0.2 to 0.4 mm and the radius when the cross section is semicircular is set in the range of 0.15 to 0.5 mm, the longitudinal elastic modulus is 90,000 to It can be in the range of 210,000 N / m ² .

  A case 11 is attached to the back side of the camera module 1. The case 11 is provided with a storage recess 11a that opens toward the subject side. The camera module 1 includes the imaging substrate 2 and the shield member 5 in a space surrounded by the recess 11a and the holder 3b. It has been stored. The case 11 is preferably made of the same material as that of the holder 3b so that the holder 3b and the thermal expansion / shrinkage are matched.

  The camera module 1 of this example is assembled by the method shown below, for example. The mounting of the imaging element 2a and the like on the imaging substrate 2 and the support of the lens 3a on the lens member 3 by the holder 3b are each completed in advance using a well-known method.

  The assembly method of the camera module 1 of the present example basically includes a first assembly process for penetrating the case 11 through the plurality of support pins 4, a second assembly process for penetrating the support pins 4 through the imaging substrate 2, and imaging. A third assembly step of attaching the shield member 5 to the substrate 2 and attaching one side 4a of the support pin 4 to the holder 3b of the lens member 3 while maintaining the image sensor 2a with respect to the lens member 3 with a predetermined gap. A fourth assembling step for superimposing and a fifth assembling step for fixing the case 11 and the support pin 4 to each other are provided.

  In the first assembly process, four support pins 4 are prepared, and one side 4a of the four support pins 4 is inserted from the back side into the four recesses 11a provided on the back side of the case 11. The case 11 is penetrated. The support pin 4 is a male screw having a spiral groove formed on one side 4a and a screw driving groove having a diameter larger than that of the pressing portion 4b at the other end. A portion 4c is provided. Further, the support pins 4 do not allow the case 11 to pass completely, but the head portion 4 c protrudes from the back side of the case 11.

  In the second assembly step, one side 4a of the support pin 4 is inserted into the through hole of the imaging substrate 2 from the other main surface side, and the holding portion 4b of the support pin 4 is penetrated through the other main surface of the imaging substrate 2. The electrode is brought into contact with a ground potential electrode provided around the hole.

  In the third assembly step, the shield member 5 made of a curved metal plate is disposed on one main surface of the imaging substrate 2 with the end in the direction of generating elasticity being joined. Further, if the shield member 5 is arranged outside the support pin 4 when viewed from the image sensor 2a, the distance between the image sensor 2a and the shield member 5 is increased. The generated electrostatic capacity can be reduced, and the performance of the camera module 1 is hardly impaired. In addition, the shield member 5 can be electrically connected to the ground wiring of the imaging substrate 2 by keeping the shield member 5 in contact with the support pins 4.

  In the fourth assembly step, one side 4a of the support pin 4 is inserted into the back side of the holder 3b of the lens member 3, and the support pin 4 is screwed into the holder 3b by rotating the head portion 4c on the other side. At this time, while screwing the support pin 4 and moving the image pickup board 2 by the pressing portion 4b of the support pin 4, an object for image adjustment is arranged on the front side at the same time, and the other main body of the image pickup board 2 is placed. The electrical signal obtained by the imaging device 2a is confirmed via a cable connected to the connector 7 mounted on the surface, and the angle between the direction in which the lens 3a condenses and the imaging substrate 2 is adjusted. The alignment with the support pins 4 is adjusted for each of the support pins 4 and the screwing of the support pins 4 is stopped at an appropriate position.

  In the fifth assembly step, the opening of the case 11 is pressed against the back side of the holder 3b of the lens member 3, and an adhesive made of an ultraviolet curable resin is placed around the head portion 4c of the support pin 4 so as to absorb the ultraviolet rays. Is applied to cure the adhesive, thereby fixing the case 11 and the support pin 4 to each other.

  According to the method of assembling the camera module 1 of this example as described above, an assembly including the imaging substrate 2, the support pins 4, the shield member 5, and the case 11 is prepared, and this assembly is attached to the lens member 3. Since it is an assembly method of attaching, if such an assembly is prepared in advance, the camera module 1 can be assembled by selecting and attaching the lens member 3 in which the lens 3a is changed. It is an assembly method of the camera module 1 that can be easily changed according to the above.

  Actually, as the imaging module of the present invention, the case 11, the barrel 35 and the retainer 34 are formed using polyphthalamide, and the lens member 3 supporting the lens 3a on the holder 3b composed of the barrel 35 and the retainer 34 is prepared. Using a copper-nickel-zinc alloy, preparing a shield member 5 with a plate thickness of 0.2 mm and a radius of 0.2 mm when the cross section is semicircular, using an iron-chromium-nickel alloy, A support pin 4 having a diameter of one side 4a of 0.8 mm and a diameter of the presser part 4b of 2.0 mm is prepared, and is made of a glass cloth base epoxy resin having a length of 12 mm, a width of 12 mm, and a thickness of 0.8 mm. A substrate 2 is prepared, a CCD image sensor is mounted on the imaging substrate 2 as the imaging element 2a, and the camera module 1 is assembled by the assembly method according to the first to fifth assembly steps described above. It was. Such a camera module 1 which is an imaging module of the present invention has a low noise in an electric signal obtained as an image signal, is easy to assemble, and has a particularly complicated structure for jigs and equipment used for assembling. Was never needed.

  As described above, according to the image pickup module of the present invention, the electromagnetic radiation noise with respect to the image pickup element is well blocked, and the image pickup board on which the image pickup element is mounted on the lens member and the shield member in the assembly of the image pickup module is mounted. As a result, it was possible to easily adjust the position of the material and to improve productivity.

  The present invention is not limited to the embodiments described above, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, in the example of the camera module 1 described above, the case where the lens member 3 includes three lenses 3a has been described as an example. However, even if the lens 3a includes one lens, the lens 3a includes two lenses 3a. It may be a case where the number of lenses 3a is four, or more.

  In the example of the camera module 1 described above, a cable connected to the connector 7 is used as a means for electrically connecting the wiring conductor of the imaging substrate 2 and the outside of the case 11. A flexible substrate may be used in place of the cable. In this case, the flexible substrate can be arranged with sufficient curvature even in a narrow space, so that the gap between the shield member 5 and the case 11 can be reduced. This is preferable.

  In the example of the camera module 1 described above, the pressing portion 4b of the support pin 4 is provided by setting the entire other side to a diameter that cannot pass through the through hole of the imaging substrate 2. 4 may be provided by setting only a part of the other side of 4 to a diameter incapable of passing through the through hole of the imaging substrate 2.

  In the example of the camera module 1 described above, the imaging substrate 2 and the lens member 3 are supported after the support pins 4 have passed through the case 11. For example, first, the support pins 4 are attached to the imaging substrate 2 on the other side. The shield member 5 is disposed on the back side of the lens member 3, the one side 4 a of the support pin 4 is inserted into the holder 3 b, and the imaging substrate 2 is aligned, and then the case The 11 openings may be bonded to the back side of the holder 3b. In this case, the back side portion of the case 11 may be bonded to the other side of the support pin 4.

It is sectional drawing of the camera module which is an example of embodiment in the imaging module of this invention.

Explanation of symbols

1. Camera module (imaging module)
2 ... Imaging substrate 2a ... Imaging device 2b ... Sub-substrate 2c ... Cavity 2d ... Lid 3 ... Lens member 3a ... Lens
31 ··· First lens
32 ... Second lens
33 ··· Third lens 3b ··· Holder
34 ... Retainer
35 ··· Barrel 4 ··· Support pin 4a ··· One side of the support pin 4b ··· Presser portion 4c ··· Head portion 5 ··· Shield member 6 ··· ..IC
7: Connector
11 ... Case
11a ・ ・ ・ ・ Recess

Claims (2)

An imaging substrate on which an imaging device for converting light into an electrical signal is mounted;
A lens member that supports a lens for condensing subject light on the image sensor with a holder;
One side is attached to the holder of the lens member, and the imaging element is overlapped with the lens member while maintaining a predetermined gap while penetrating the imaging substrate and being held by a pressing part on the other side. A plurality of support pins to support in a state;
An imaging module comprising: a shield member that has elasticity and is disposed between the imaging substrate and the holder so as to surround the imaging element and presses the imaging substrate toward the pressing portion.   The imaging module according to claim 1, wherein the shield member is a metal plate provided with a curved portion between the imaging substrate and the holder.

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