JP4652149B2 - The camera module - Google Patents

Description

  The present invention relates to a camera module manufacturing method and a camera module.

  A camera module including a lens group and an image sensor is known (for example, Patent Document 1). In such a camera module, it is necessary to adjust the position of the lens group and the image sensor in the optical axis direction to an appropriate position during assembly.

FIG. 6 is a cross-sectional view showing a conventional camera module. A conventional camera module 101 includes a lens barrel 103 that holds a lens group 102 and a case 106 that holds a substrate 105 on which an image sensor 104 is provided. In the adjustment of the position of the lens group 102 of the camera module 101 and the image sensor 104 in the optical axis direction, the substrate 105 from the side opposite to the lens group 102 (the right side of the drawing) with respect to the support member 106a provided on the case 106. The lens barrel 103 is moved in the optical axis direction with respect to the case 106 and finely adjusted while referring to the image picked up by the image pickup device 104 while being positioned in the optical axis direction.
JP 2003-46875 A

  In recent years, downsizing of camera modules such as in-vehicle cameras and mobile phone cameras has been desired. However, for example, if the lens barrel and the case are integrated for miniaturization, the lens group cannot be moved with respect to the case, and the relative position in the optical axis direction between the lens group and the image sensor is adjusted. I can't.

  An object of the present invention is to provide a method for manufacturing a camera module and a camera module that can adjust the relative position between the lens and the image pickup element while the lens is fixed to a case.

  The method for manufacturing a camera module of the present invention is a method for manufacturing a camera module in which a support member extending in the optical axis direction of a lens is provided in a case, and a substrate that holds an image sensor is fixed to a side surface of the support member. A lens fixing step of fixing the lens to the case; and a substrate fixing step of fixing the substrate on which the imaging element is provided to the case to which the lens is fixed. , Positioning the substrate in the direction of the optical axis while fixing the substrate with respect to the side surface of the support member while referring to the image quality of the image picked up by the light from the lens being imaged on the imaging device To do.

  The camera module of the present invention includes a lens, an image sensor on which light from the lens forms an image, a substrate that holds the image sensor, and a case that holds the lens and the substrate. A support member extending in the optical axis direction of the lens is provided, and the substrate is held by the case by being fixed to a side surface of the support member.

  Preferably, the side surface of the support member to which the substrate is fixed is formed by a plane or a curved surface extending in parallel to the optical axis so that the substrate can be fixed while adjusting the position in the optical axis direction of the substrate. .

  Preferably, the substrate has a through hole through which the support member is inserted.

  Suitably, the said through-hole is a notch part which notched the edge part of the said board | substrate.

  Preferably, the substrate is fixed to the support member with solder.

  Preferably, the support member has a C-shaped cross section.

  Preferably, the case includes a front surface case member integrally formed including a front surface portion that covers the lens side of the substrate and a lens holding portion that contacts the lens and holds the lens. The support member is provided on the front side case member.

  Preferably, the lens holding portion is formed to include a protruding portion protruding from the front surface portion to at least one of the outer side and the inner side of the case, and holds the lens on the protruding portion.

  Preferably, a shield body that shields the substrate is further provided, the support member has conductivity, and the ground of the substrate and the shield body are electrically connected by the support member.

  According to the present invention, it is possible to adjust the relative position between the lens and the image sensor while the lens is fixed to the case.

  FIG. 1 is a cross-sectional view showing a camera module 1 according to an embodiment of the present invention. The camera module 1 is configured as an in-vehicle camera for imaging a white line on a road or a blind spot of a vehicle, for example, and an ECU (Engine Control Unit) (not shown) that controls driving of the automobile The operation is controlled by. 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), for example.

  The camera module 1 includes a lens group 2, an image sensor 3 on which light from the lens group 2 forms an image, a main board 4 that holds the image sensor 3, and a case 5 that holds the lens group 2 and the main board 4. I have.

  The lens group 2 includes, for example, a first lens 7, a second lens 8, and a third lens 9 that are stacked from the subject side (the left side of the drawing). Each of the lenses 7 to 9 is made of, for example, glass or plastic. The first lens 7 is in contact with the subject side surface of the lens holding portion 5 a of the case 5 and is restrained from the subject side by the retainer 11. The retainer 11 is fixed to the side surface of the lens holding portion 5a with, for example, an adhesive or solder. The second lens 8 and the third lens 9 are press-fitted into an opening 5b that opens in the lens holding portion 5a, and are fixed by, for example, an adhesive or solder. The second lens 8 and the third lens 9 are in contact with a positioning portion (not shown) protruding from the wall surface of the opening 5b, for example, and the positions in the optical axis direction are fixed. Note that a mask or a diaphragm may be provided at an appropriate position of the lens group 2, or the outer periphery of the first lens 7 may be fixed by the lens holding portion 5a like the second lens 8 or the like.

  The image sensor 3 is configured by, for example, a CCD or a CMOS. The image sensor 3 is housed in the sub-board 13. The sub-board 13 is made of, for example, a ceramic wiring board whose main component is alumina, and houses the imaging device 3 in a cavity (not shown) formed on the subject side. The cavity is sealed with a glass lid 4. A plurality of terminals 13 a extend from the sub-board 13 and are fixed to the main board 4 with solder or the like. The image pickup device 3 and the main board 4 are electrically connected by the terminal 13a, and the sub board 13 is supported by the main board 4.

  The main substrate 4 is constituted by, for example, a printed wiring board formed by impregnating a glass cloth with an epoxy resin or adding a glass filler to the epoxy resin. The addition amount of the glass cloth or the glass filler is preferably set so that the thermal expansion coefficient of the sub-board 13 and the thermal expansion coefficient of the main board 4 are equal. On the surface of the main board 4 opposite to the image pickup device 3, an IC 16 for processing an electric signal from the image pickup device 3, a connector 17 for connecting a cable 18 for connecting the main substrate 4 and an ECU (not shown), and the like. Is provided.

  The case 5 includes a front-side case member 21 disposed on the subject side and a back-side case member 22 disposed on the back side thereof, and a housing space defined by the front-side case member 21 and the back-side case member 22. The image pickup device 3 and the main substrate 4 are accommodated in the main body. The front side case member 21 and the back side case member 22 are made of, for example, a resin such as polycarbonate (PC) or polyphthalamide (PPA) to reduce weight.

  The front side case member 21 includes a front surface portion 21 a that covers the subject side of the image sensor 3 and the main substrate 4, and a side surface portion 21 b that is continuous with the front surface portion 21 a and surrounds the periphery of the image sensor 3 and the main substrate 4. . The front surface portion 21a is generally formed in a cone shape as a whole, and the lens holding portion 5a described above is provided on the center side. The lens holding part 5a, the front part 21a, and the side part 21b are integrally formed by injection molding or the like.

  A boss 21c protruding in the optical axis direction is provided inside the front surface portion 21a of the front case member 21. A support member 24 for holding the main board 4 is fixed to the boss 21c, and a shield case 25 for shielding the image pickup device 3, the main board 4 and the like is fixed. The support member 24 and the shield case 25 are formed of a conductive material such as metal and are electrically connected to each other in the boss 21c. For example, the support member 24 and the shield case 25 are arranged in a cavity that forms the front side case member 21 in a state of being connected to each other, and molten resin is poured into the cavity to form the front side case member 21. Thus, the front case member 21 is fixed.

  The shield case 25 is, for example, formed in a box shape that is slightly smaller than the case 5 as a whole, is disposed along the inner peripheral surface of the case 5, and includes a side surface that surrounds the image sensor 3 and the main substrate 4. The front side case member 21 has a front surface portion that is disposed along the inner peripheral surface of the front surface portion 21 a and covers the subject side of the main substrate 4.

  The back side case member 22 includes a side surface portion 22 a that is continuous with the side surface portion 21 b of the front surface side case member 21, and a back surface portion 22 b that covers the back surface side of the main substrate 4 (the side opposite to the imaging device 4). The side surface portion 21b of the front side case member 21 and the side surface portion 22a of the back side case member 22 are fixed to each other by, for example, an adhesive or solder. An opening for inserting the cable 18 is opened in the back surface portion 22b.

  The cable 18 includes, for example, a plurality of cables 27 extending from the connector 17 in the case 5 and a cable 29 connected to the plurality of cables 27 via the connector 28 and extending from the case 5. The back side case member 22 is fixed by being fixed to the opening of the portion 22b with an adhesive or the like.

  FIG. 2 is a schematic view showing a mounting structure between the front case member 21 and the main board 4, and is a perspective view seen from the back side of the camera module 1 (the right side in FIG. 1). For example, four support members 24 are provided corresponding to the four corners of the rectangular main substrate 4. The support member 24 is generally formed in an axial shape, and extends in parallel with the optical axis LL (see also FIG. 1).

  On the other hand, the main substrate 4 has a through hole 4a through which the support member 24 is inserted. The through-hole 4a is also a cut-out part in which the edge of the main substrate 4 is cut out. In FIG. 2, the through-hole 4a in the upper part of the paper and the through-hole 4a in the lower part of the paper are cut out. The case where the direction is set to a direction orthogonal to each other is illustrated.

  FIG. 3 is a cross-sectional view of the support member 24 shown in a state where the support member 24 is inserted into the through hole 4a. The cross-sectional shape of the support member 24 is C-shaped. The outer diameter of the support member 24 and the inner diameter of the through hole 4a are set so that a gap is generated between the support member 24 and the through hole 4a. Regarding the dimensions of the support member 24 and the like, for example, the inner diameter D1 of the through hole 4a is 1.5 mm, the outer diameter D2 of the support member 24 is 1.0 mm, and the thickness t1 of the support member 24 is 0.15 mm.

  The main substrate 4 is fixed to the side surface (side surface in the longitudinal direction, surface parallel to the optical axis LL) of the support member 24 by, for example, solder. Further, since it is fixed by solder, the ground layer of the main board 4 is electrically connected to the shield case 25 via the support member 24. In order to make the fixing by soldering firmer, it is preferable to form a metal-based thin film on the inner peripheral surface of the through hole 4a of the main substrate 4 in advance and perform metallization.

  A method for assembling the camera module 1 will be described.

  First, the lens group 2 is attached to the front case member 21 and fixed by the retainer 11 (lens fixing step). As a result, the lens group 2 cannot move with respect to the front side case member 21 in any of the optical axis direction, the direction around the optical axis, and the direction orthogonal to the optical axis.

  Next, the main board 4 to which the image sensor 3 and the sub board 13 are attached is fixed to the front case member 21 (board fixing process). Specifically, first, the main board 4 is positioned by inserting the support member 24 into the through hole 4 a of the main board 4. At this time, the cable 18 is connected to an inspection device (not shown), and an image captured by the image sensor 3 is referred to and evaluated by the inspection device. For example, it is evaluated whether or not the camera module 1 is focused on a test subject that is separated from the lens group 2 by a predetermined distance. The image quality may be evaluated by displaying an image captured by the image sensor 3 on a monitor and allowing the operator to visually recognize the image. Then, the main board 4 is positioned based on the evaluation. In positioning, the position of the main substrate 4 with respect to the lens group 2 in the optical axis direction, the tilt with respect to the optical axis, and the position in the direction orthogonal to the optical axis are adjusted. Thereafter, the main board 4 is fixed to the support member 24 with solder.

  In addition, in the above assembly, a part or all may be automated, or an operator may perform it manually.

  According to the above embodiment, since the support member 24 extending in the optical axis direction of the lens group 2 is provided in the case 5 and the main substrate 4 is fixed to the side surface of the support member 24, the main substrate 4 is supported. The main substrate 4 can be fixed at an appropriate position by moving along the member 24. In other words, the distance between the lens group 2 and the image sensor 3 can be appropriately set by adjusting the position of the image sensor 3 in the optical axis direction. Therefore, for example, the lens holding portion 5a for holding the lens and the front surface portion 21a of the front case member can be integrally formed to reduce the size.

  Since the main board 4 has a through-hole 4a through which the support member 24 is inserted, the main board 4 can be easily attached to the support member 24 and fixed from a liquefied state such as solder or adhesive. When fixed by means, the main substrate 4 and the support member 24 can be fixed more firmly than in the case where the through hole 4a is not provided. Specifically, this is as shown in FIG. FIG. 4A is an enlarged view of the through hole 4 a and the support member 24 when the support member 24 is inserted into the through hole 4 a and soldered. As shown in this figure, when the support member 24 is inserted and fixed in the through hole 4a, the solder 35 spreads evenly around the support member 24, and the main board 4 extends along the longitudinal direction of the support member 24. The main board 4 can be fixed to the support member 24 in a state of spreading to both sides.

  Since the through-hole 4a is also a cutout portion in which the edge of the main board 4 is cut out, the support board 24 and the support board 24 due to the thermal expansion of the main board 4 are used as shown in FIG. 4 is absorbed by the deformation on the edge side of the main board 4 and the main board 4 is prevented from being damaged.

  Since the support member 24 has a C-shaped cross section, the stress from the main board 4 to the support member 24 due to thermal expansion of the support member 24 and the main board 4 is caused by the support member 24 as shown in FIG. The main substrate 4 is prevented from being damaged by being absorbed by the deformation that causes the 24 notch portions to approach or separate from each other.

  Since the ground layer of the main substrate 24 and the shield case 25 are electrically connected by the support member 24, it is not necessary to provide a member for connecting the main substrate 24 and the shield case 25, and the size can be further reduced. Figured.

  FIG. 5A and FIG. 5B are diagrams showing a part of another embodiment of the present invention. In addition, about the structure similar to the above-mentioned embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  5A, in the lens group 2, the lens holding portion 51a for holding the second lens 8 and the second lens 9 in the lens group 2 is from the front side 51b of the front side case member 51 to the subject side (upper side in the drawing). It is formed so as to protrude. In other words, the region SP1 indicated by the dotted line of the front surface portion 51b is cut. For this reason, the stress due to the thermal expansion of the front case member 51 is directly transmitted only to the case side (the lower side of the drawing surface) of the lens holding portion 51a that is continuous with the front portion 51b, and to the front end side (the drawing surface of the lens holding portion 51a). The stress from the front side case member 51 is not easily transmitted to the protruding portion 51c on the upper side. Therefore, even if the lens holding part and the case are integrally formed to reduce the size, the lens can be protected from stress due to thermal expansion from the case. 5A illustrates the state in which only the second lens 8 is held by the protruding portion 51c, the third lens 9 may also be held by the protruding portion 51c.

  5B, in the lens group 2, the lens holding portion 61a that holds the second lens 8 and the second lens 9 in the lens group 2 extends from the front surface portion 61b of the front surface side case member 61 to the case inner side (the lower side of the drawing). ) Protruding. In other words, the region SP2 indicated by the dotted line of the front surface portion 61b is cut. For this reason, as in FIG. 5A, in the protrusion 61c inside the case of the lens group 2, the stress due to thermal expansion of the front case member 51 is difficult to be transmitted, and the lens is protected from the stress due to thermal expansion from the case. it can. 5B illustrates a state in which only the third lens 9 is held by the protruding portion 61c, the second lens 8 may also be held by the protruding portion 61c.

  Note that the first lens 7 may be fixed to the subject side surface of the front surface 51b or 61b by a retainer, for example. In the present embodiment, since the first lens 7 is not surrounded by the case on the outer peripheral side like the second lens 8 and the third lens 9, the influence of thermal expansion of the case is small.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The camera module is not limited to a vehicle-mounted one, and may be for a mobile phone, for example. The lens group only needs to include at least one lens that forms an optical image on the image sensor. The case only needs to hold a substrate on which a lens and an image sensor are provided. Therefore, it is not limited to the case-like one, and in the case of the case-like shape, it is not limited to the one constituted by the front side case member and the rear side case member. For example, as shown in FIG. It may be configured by a box and a lid, or may be a lid disposed on the subject side and a box disposed on the back side.

  The support member extends in the optical axis direction, and it is sufficient that the substrate can be fixed to the side surface. Therefore, for example, it may be integrally formed with the case, may not have electrical conductivity, the cross-sectional shape may not be C-shaped, and is provided on the side surface instead of the front surface portion of the case. It may be. In the embodiment, the case where the support member and the shield case are arranged in the cavity at the time of molding the case is illustrated, but the support member and the shield body may be fixed by an adhesive or the like after the case is molded. The shield body is not an essential requirement for the present invention.

  The method for fixing the substrate and the support member is not limited to fixing by solder as long as the substrate can be fixed at an appropriate position on the side surface of the support member. For example, it may be fixed with an adhesive. However, if it is fixed by soldering, it is easy to electrically connect the support member and the substrate. Further, the through hole is not essential. For example, the edge of the rectangular substrate may be brought into contact with the side surface of the support member as it is to fix the substrate to the support member.

  The front side cover integrally formed including the lens holding part and the front part is not limited to the one integrally formed by injection molding. Two or more members are not necessarily fixed to each other, and may be formed, for example, by bending a metal. When the case is made of metal, the case can also serve as a shield body.

  In addition, from the above-mentioned embodiment, it is provided with a lens, an image sensor on which light from the lens forms an image, a substrate that holds the image sensor, and a case that holds the lens and the substrate, A front portion covering the lens side of the substrate and a lens holding portion that contacts the lens and holds the lens are formed by integral molding, and the lens holding portion extends from the front portion in the optical axis direction. The invention of the camera module formed so as to protrude can be extracted. In the invention, preferably, the case has a side surface portion that is continuous with the front surface portion and surrounds the periphery of the substrate.

Sectional drawing which shows the camera module of embodiment of this invention. The perspective view which shows the attachment structure of the board | substrate of the camera module of FIG. FIG. 2 is an enlarged cross-sectional view of a support member of the camera module in FIG. 1. The enlarged view of the attachment structure of the camera module of FIG. Sectional drawing which shows a part of camera module of other embodiment of this invention. Sectional drawing which shows the conventional camera module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Camera module, 3 ... Image sensor, 4 ... Main board | substrate, 5 ... Case, 7, 8, 9 ... Lens, 24 ... Support member.

Claims (9)

A lens,
An image sensor on which light from the lens forms an image;
A substrate for holding the image sensor;
A case for holding the lens and the substrate;
With
The case is provided with a support member extending in the optical axis direction of the lens,
In the substrate, the inner diameter is larger than the outer diameter of the support member, and a through hole through which the support member is inserted is opened.
The substrate is held by the case by being fixed to a side surface of the support member by a fixing means that is solidified from a liquefied state ,
The imaging module and the substrate are spaced apart from the lens and the case, and are positioned relative to the case only by the fixing means and the support member . The support member has one end on the lens side fixed to the case, and the other end is a free end separated from the case.
The camera module according to claim 1. A shield body for shielding the substrate;
Wherein the support member has a conductive are ground and electrically connected to the substrate,
The case has a boss protruding in the optical axis direction,
It said supporting member and said shield body, a camera module according to claim 1 or 2 are electrically connected to each other with a part thereof being fixed to the casing by being embedded in the boss. The shield body is separated from the case except for the boss.
The camera module according to claim 3. A lens,
An image sensor on which light from the lens forms an image;
A substrate for holding the image sensor;
A case for holding the lens and the substrate;
With
The case is provided with a support member extending in the optical axis direction of the lens,
The substrate is held on the case by being fixed to the side surface of the support member,
The substrate has a through hole through which the support member is inserted,
The through hole is a cutout portion formed by cutting out an edge portion of the substrate.
Camera module. The camera module according to claim 5 , wherein the support member has a C-shaped cross section. The side surface to which the substrate of the support member is fixed is formed by a plane or a curved surface extending in parallel to the optical axis so that the substrate can be fixed while adjusting the position in the optical axis direction of the substrate . 7. The camera module according to any one of 6 . The case includes a front surface case member formed integrally including a front surface portion that covers the lens side of the substrate and a lens holding portion that contacts the lens and holds the lens.
Wherein the support member, a camera module according to any one of claims 1 to 7 provided on the front side case member. The camera according to claim 8, wherein the lens holding portion is formed to include a protruding portion that protrudes from the front surface portion to at least one of the outer side and the inner side of the case, and holds the lens in the protruding portion. module.

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