JP2007228463A - Camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module which can accurately fix the photodetection plane of an imaging device vertically with respect to the optical axis of a lens and whose imaging performance is high. <P>SOLUTION: The camera module comprises an imaging device 1 which converts light into an electric signal; a board 21 electrically connecting the imaging device; a lens 41 which converges light from an object to form an image in the imaging device 1; a bracket 42 which holds the lens 41; and a plate 11 having a first plane, wherein the first plane of the plate 11 is brought into contact with the rear side of the imaging device 1 and is fixed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera module that integrates an image sensor and a lens and is used for an in-vehicle camera, a mobile phone, or the like.

  2. Description of the Related Art Conventionally, a camera module is known that is used for an in-vehicle camera, a mobile phone, and the like by combining a lens and a circuit board including an image pickup device and an image pickup processing circuit so as to be integrated and reduced in size and thickness.

  FIG. 3 shows a structural diagram of a conventional camera module. The imaging element 101 is held by soldering the lead wire 102 to the substrate 103 and is electrically connected to an imaging processing circuit mounted on the same substrate. The lens 105 is held by the lens bracket 104. The substrate 103 on which the image sensor 101 is mounted and the lens bracket 104 holding the lens 105 are fastened with screws 106.

  With this structure, light from the object is condensed on the image sensor 101 by the lens 105, the light is converted into an electric signal by the image sensor 101, and an image signal is formed by the image pickup processing circuit mounted on the substrate 103. The

In such a camera module, in order to correctly form light from the object on the light receiving surface 108 of the image sensor 101, the light receiving surface 108 of the image sensor 101 should be kept perpendicular to the optical axis 107 of the lens 105. Become important. Since the perpendicularity between the optical axis of the lens 105 and the substrate 103 is maintained via the lens bracket 104, the parallelism of the lens 105 is maintained by holding the image sensor 101 parallel to the substrate 103 when mounting the image sensor 101. A perpendicularity with the optical axis 107 is ensured (see, for example, Patent Document 1).
JP 2002-182270 A (FIG. 1)

  However, in the conventional camera module, the perpendicularity of the light receiving surface 108 of the image sensor 101 with respect to the optical axis 107 of the lens 105 depends on the mounting accuracy of the lead wire 102, so that the light receiving surface 108 may be mounted on the substrate 103 depending on the soldering state. There is a problem that it is difficult to ensure the perpendicularity to the optical axis 107 of the lens 101.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a camera module that secures the perpendicularity between the light receiving surface of an image sensor and the optical axis of a lens and has high imaging performance.

  The camera module of the present invention includes an imaging device that converts light into an electrical signal, a substrate that electrically connects the imaging device, a lens that collects light from an object and forms an image on the imaging device, and a lens. A holding bracket and a plate having a first plane are provided, and the first plane of the plate is fixed in contact with the back surface of the image sensor.

  With this configuration, the parallelism between the image sensor and the plate can be maintained without being affected by mounting variations during soldering, so that the light receiving surface of the image sensor can be accurately and vertically fixed to the lens optical axis. And a camera module with high imaging performance can be realized.

  The plate of the camera module of the present invention further includes a second plane and a first mounting hole for coupling to the substrate, and is more than the thickness between the first plane and the second plane. It is set as the structure formed so that the thickness of the part which has 1 attachment hole was thickened.

  With this configuration, the fixing member for attaching the substrate to the plate is inserted while securing the length of the soldered portion of the lead wire obtained by subtracting the total thickness of the plate and the substrate from the length of the lead wire of the imaging device. The thickness of the part can be ensured.

  In addition, the plate of the camera module of the present invention is configured to have a recess having a shape corresponding to the outer shape of the image sensor.

  With this configuration, the concave portion serves as an insertion guide when the imaging element is inserted into the lead wire insertion hole of the substrate while passing through the hole of the plate, so that the insertion operation is facilitated.

  The plate of the camera module of the present invention further includes a second mounting hole for coupling to the bracket, and the substrate includes a mounting hole provided for coupling to the plate at a position corresponding to the first mounting hole. And a notch provided at a position corresponding to the second mounting hole.

  With this configuration, the image pickup device module in which the image pickup device and the substrate are combined via the plate can be formed independently of the lens bracket, and when the image pickup device module is connected to the lens bracket, the substrate is formed by a connecting operation. Can be prevented from being distorted or damaged.

  The plate of the camera module of the present invention is made of metal.

  With this configuration, the upper and lower surfaces are ensured to have horizontality and flatness, and deformation due to heat during soldering does not occur.

  Furthermore, the plate of the camera module of the present invention is made of an aluminum alloy. With this configuration, it is composed of an aluminum alloy that has high rigidity and good thermal conductivity, so that the upper and lower surfaces are ensured to be horizontal and flat, and can be prevented from being deformed by heat during soldering. The weight of the camera module can be reduced.

    The camera module of the present invention has an effect that the light receiving surface of the image sensor can be accurately and vertically fixed with respect to the optical axis of the lens, and a camera module with high imaging performance can be realized.

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

  FIG. 1 is a sectional view showing a schematic structure of a camera module of the present invention. The camera module according to the embodiment of the present invention includes an imaging device 1 that converts light into an electrical signal, a substrate 21 that electrically connects the imaging device 1, and light from an object to be collected on the imaging device 1. The lens 41 includes an image forming lens 41, a bracket 42 that holds the lens 1, and a plate 11 having two planes, an upper surface and a lower surface.

By superimposing the back surface of the image sensor 1 and the upper surface of the plate 11, the image sensor 1 and the plate 11 are in surface contact. The plate 11 and the substrate 21 are fixed with screws 31.

  By soldering the lead wire 2 of the image sensor 1 to the substrate 21, the image sensor 1 and the substrate 21 are electrically connected, and the back surface of the image sensor 1 and the plate 11 are fixed while maintaining parallelism. .

  Further, the plate 11 is fixed to the lens bracket 42 in which the lens 41 is preliminarily incorporated by the screws 32. As a result, a camera module is formed in which the imaging device 1, the plate 11, the substrate 21, the lens 41, and the lens bracket 42 are integrally assembled.

  The lens bracket 42 is formed so that the perpendicularity between the optical axis 43 of the lens 41 and the plate 11 can be secured by fixing with the screw 32. Therefore, by ensuring the parallelism between the image sensor 1 and the plate 11, the light receiving surface 3 of the image sensor 1 can be accurately fixed perpendicularly to the optical axis 43 of the lens 41.

  FIG. 2 is a perspective view showing the structure of the camera module of the present invention. The structure and assembly method of the camera module of the present invention will be described with reference to FIG.

  As described with reference to FIG. 1, the camera module includes the imaging device 1, the substrate 21, the lens 41, the bracket 42 that holds the lens 41, and the plate 11 having a flat surface.

  First, the back surface of the image sensor 1 and the upper horizontal plane of the plate 11 are set so as to come into surface contact. Further, the plate 11 and the substrate 21 are fixed by passing through the plate mounting hole 22 provided in the substrate 21 and fastening with the screw 31 to the substrate mounting hole 13 provided in the plate 11.

  The plate 11 is formed so that the boundary between the thickened portion and the thinned portion corresponds to the outer shape of the image sensor 1. As a result, the recess 15 formed in the portion having a different thickness of the plate 101 serves as an insertion guide when the imaging element 1 is inserted into the lead wire hole 23 of the substrate 21 while passing through the imaging element insertion hole 12. Becomes easier.

  Further, the plate 11 is provided with a substrate mounting 13 for coupling with the substrate 21 and a bracket mounting hole 14 for coupling with the bracket. As a result, the joining work between the plate 11 and the substrate 21 can be performed independently of the joining work between the plate 11 and the lens bracket 42, so that the assembly is easy.

  Next, in this state, the image sensor 1 and the substrate 21 are electrically connected by fixing the lead wire 2 of the image sensor 1 to the substrate 21 by soldering. At this time, soldering is performed with the upper horizontal plane of the plate 11 in contact with the back surface of the image sensor 1. Thereby, the image sensor 1 and the plate 11 are fixed while maintaining parallelism.

  Here, the lens bracket 42 is formed so as to ensure the perpendicularity between the optical axis 43 of the lens 41 and the plate 11 by fixing with the screw 32. Therefore, by ensuring the parallelism between the image pickup device 1 and the plate 11, the light receiving surface 3 of the image pickup device 1 can be accurately fixed perpendicularly to the optical axis 43 of the lens 41, and high image pickup performance can be realized.

In order to solder the lead wire 2 of the image sensor 1 during the soldering operation, the solder margin portion of the lead wire 2 requires about 1.5 mm. The length of the lead wire 2 is usually 3 from the lower surface of the image sensor 1.
. Although it is about 5 mm, the thickness of the plate 11 is 1 mm or less when a total of 2.5 mm, which is 1.5 mm of the soldering portion necessary for soldering and the thickness of 1 mm of the substrate 21, is subtracted from the length of the lead wire 2 of the image sensor 1. Must be.

  On the other hand, in order to fix the substrate 21 and the plate 11 with the screws 31, the plate 11 needs to have a thickness of about 2 mm. In order to solve this, the plate 11 is formed so that the thickness of the portion having the substrate mounting hole 13 is increased, and the thickness of the portion where the back surface of the image sensor 1 and the upper surface of the plate 11 are in contact with each other is reduced. Thereby, while ensuring the solder margin length of the lead wire 2 to 1.5 mm or more, the thickness of the plate 11 can be secured to 2 mm so that the substrate 21 and the plate 11 can be fixed with the screws 31.

  Further, since the plate 11 is made of the same metal as the lens bracket 42, such as an aluminum alloy, the plate 11 has the same coefficient of thermal expansion and thus is not easily deformed and has high heat resistance against heat during soldering.

  Next, the plate 11 is fixed to the lens bracket 42 by fastening the screw 32 to the fixing screw hole (not shown) provided in the bracket 42 via the bracket mounting hole 14 provided in the plate 11. . The lens bracket 42 incorporates the lens 41 in advance, and the camera module is completed.

  The substrate 21 is provided with a plate mounting hole 22 provided at a position corresponding to the plate mounting hole 13 and a notch 24 provided at a position corresponding to the bracket mounting hole 14. Thereby, when the plate 11 is coupled to the lens bracket 42, it is not necessary to fasten together with the substrate 21, so that the substrate 21 can be prevented from being distorted or damaged by the coupling operation.

  Further, the plate 11 forms an end face by reducing the thickness around the bracket mounting hole 14. On the other hand, by increasing the thickness of the portion corresponding to the end surface of the lens bracket 42 side, the lens bracket 42 side serves as a guide when the two are combined, and also has a role of preventing rotation when fixed with the screw 32.

  As described above, according to the embodiment of the present invention, the image pickup device 1 and the plate 11 are fixed while maintaining parallelism, and the light receiving surface 3 of the image pickup device 1 is fixed vertically accurately with respect to the optical axis of the lens 41. Therefore, it is possible to correctly form an image on the light receiving surface 3 and to realize a camera module with high imaging performance.

  In the present embodiment, the case where the imaging device 1 and the substrate 21 are held horizontally by the plate 11 has been described. However, depending on the configuration of the camera module, the optical axis 43 of the lens 41 and the light receiving surface 3 of the imaging device 1 May have a plane having a certain angle with respect to the substrate 21 as long as it has a plane that is held vertically.

  The camera module according to the present invention can accurately fix the light receiving surface of the image sensor perpendicular to the lens optical axis, so that the image sensor and the lens are integrated into a camera module or the like used for an in-vehicle camera or a mobile phone. Useful.

Sectional drawing which shows the structure of the camera module of this invention The perspective view which shows the structure of the camera module of this invention Sectional drawing which shows the structure of the conventional camera module

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pick-up element 2 Lead wire 3 Light-receiving surface 11 Plate 12 Image pick-up element insertion hole 13 Substrate attachment hole 14 Bracket attachment hole 15 Recess 21 Substrate 22 Plate attachment hole 23 Lead wire hole 24 Notch 31, 32 Screw 41 Lens 42 Lens bracket 43 Optical axis

Claims (6)

An image sensor that converts light into an electrical signal;
A substrate for electrically connecting the image sensor;
A lens that focuses light from the object and forms an image on the image sensor;
A bracket holding the lens;
A camera module comprising: a plate having a first plane; wherein the first plane of the plate is fixed in contact with the back surface of the imaging device. The plate includes a second plane;
A first mounting hole for coupling with the substrate;
2. The camera module according to claim 1, wherein a thickness of a portion having the first mounting hole is made thicker than a thickness between the first plane and the second plane. The camera module according to claim 1, wherein the plate has a recess having a shape corresponding to an outer shape of the imaging element. The plate further includes a second mounting hole for coupling with the bracket;
The substrate has a mounting hole provided for coupling to the plate at a position corresponding to the first mounting hole;
The camera module according to claim 1, further comprising a notch portion provided at a position corresponding to the second attachment hole. The camera module according to claim 1, wherein the plate is made of metal. The camera module according to claim 1, wherein the plate is an aluminum alloy.

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