JP2013078026A - Imaging module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging module capable of outputting a clear image.SOLUTION: An imaging module 1 comprises; a lens 2; an imaging device 3 where light from the lens 2 forms an image; a package 13 having the imaging device 3 mounted on the inner bottom surface; an imaging board 4 to which the package 13 is connected via plural pieces of solders 25; and a case 5 which holds the lens 2 and the imaging board 4. In order that the light-receiving surface of the imaging device 3 become parallel to the lens 2, the heights of the pieces of solder 25 are made different from one another. Since the inclination of the imaging device 3 is corrected in order that the light-receiving surface of the imaging device 3 become parallel to the lens 2, the image becomes clear.

Description

  The present invention relates to an imaging module.

  The image sensor is mounted on the inner bottom surface of the package via a bonding material. The outer bottom surface of this package is mounted on the main surface on the lens side of the imaging substrate.

JP 2007-4068

  If the thickness of the bonding material is not uniform, the light receiving surface of the image sensor is tilted, the light receiving surface is not parallel to the lens, and the image is unclear.

  An imaging module of the present invention includes a lens, an imaging device on which light from the lens forms an image, a package on which the imaging device is mounted on the inner bottom surface, and an imaging substrate to which the package is connected via a plurality of solders And a case for holding the lens and the imaging substrate, wherein a difference in height of the plurality of solders is provided so that a light receiving surface of the imaging element is parallel to the lens. It is a feature.

  An imaging module of the present invention includes a lens, an imaging element on which light from the lens forms an image, a package on which the imaging element is mounted on the inner bottom surface, and an imaging in which the package is connected via a plurality of lead members. An imaging module having a substrate and a case for holding the lens and the imaging substrate, wherein the lead member has a difference in length so that a light receiving surface of the imaging element is parallel to the lens. It is a feature.

  The imaging module of the present invention includes a lens, an imaging element on which light from the lens forms an image, a package on which the imaging element is mounted on the inner bottom surface, and the package connected to one main surface on the lens side. An imaging module having an imaging substrate, and a case for holding the lens and the imaging substrate, wherein an outer bottom surface of the package and one main surface of the imaging substrate are inclined with respect to each other, and a lower surface of the imaging element The angle formed by the inner bottom surface of the package is the same as the angle formed by the outer bottom surface of the package and one main surface of the imaging substrate.

  According to the imaging module of the present invention, since the tilt of the imaging device is corrected so that the light receiving surface of the imaging device and the lens are parallel, the image becomes clear.

It is sectional drawing which shows the imaging module of embodiment of this invention. It is a perspective view which shows the attachment structure of the imaging substrate of the imaging module of FIG. (A) is the perspective view which extracted the bottom face of the package and the bonding | jointing material. It is a perspective view of other embodiment different from what was shown in FIG. It is sectional drawing which shows the imaging module of the other example of embodiment of this invention. It is sectional drawing which shows the imaging module of the other example of embodiment of this invention. It is sectional drawing which shows the imaging module of the other example of embodiment of this invention. It is sectional drawing which shows the imaging module of the other example of embodiment of this invention.

  Hereinafter, an exemplary embodiment of an imaging module of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an imaging module 1 according to an embodiment of the present invention, which is configured as, for example, an in-vehicle camera for imaging a white line on a road or a blind spot of a vehicle. The operation is controlled by the illustrated ECU (Engine Control Unit). The electrical signal output from the imaging module 1 is converted into an image signal by the ECU and displayed on a display (not shown), for example.

  The imaging module 1 includes a lens group 2, an imaging device 3 on which light from the lens group 2 forms an image, an imaging substrate 4 that holds the imaging device 3, and a case 5 that holds the lens group 2 and the imaging substrate 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 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. In addition, an imaging element 3 and an imaging substrate 4 described later are accommodated. 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 21a that covers the subject side of the image sensor 3 and the imaging substrate 4, and a side surface portion 21b that is continuous with the front surface portion 21a and surrounds the periphery of the image sensor 3 and the main substrate 4. . The front surface portion 21a is generally formed in a rectangular parallelepiped shape as a whole, and the above-described lens holding portion 5a 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.

  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 imaging substrate 4 (the side opposite to the image sensor 3). 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 (not shown) for inserting the cable opens in the back surface portion 22b.

FIG. 2 is a schematic view showing a mounting structure between the front case member 21 and the imaging substrate 4, and is a perspective view seen from the back side (the right side in FIG. 1) of the imaging module 1. For example, four support members 24 are provided corresponding to the four corners of the rectangular imaging 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 imaging 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 image pickup 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.
Regarding the dimensions of the support member 24 and the like, for example, the inner diameter of the through hole 4a is 1.5 mm, and the outer diameter of the support member 24 is 1.0 mm.

  The imaging substrate 4 is fixed to the side surface (a side surface in the longitudinal direction, a surface parallel to the optical axis LL) of the support member 24 by, for example, solder. Further, in order to make the fixing by soldering firmer, it is preferable to form a thin film mainly composed of metal on the inner peripheral surface of the through hole 4a of the main substrate 4 in advance and perform metallization.

  The imaging substrate 4 is configured by, for example, a printed wiring board formed by impregnating a glass cloth with an epoxy resin or adding a glass filler to an epoxy resin. The addition amount of the glass cloth or the glass filler is preferably set so that the thermal expansion coefficient of the package 13 and the thermal expansion coefficient of the imaging substrate 4 are equal. An IC (not shown) that processes an electrical signal from the image pickup device 3 and a cable (not shown) that connects the image pickup substrate 4 and an ECU (not shown) are provided on the surface of the image pickup substrate 4 opposite to the image pickup device 3. A connector (not shown) for connection is provided.

  The image sensor 3 is configured by, for example, a CCD or a CMOS.

  The package 13 includes a housing 13a having a cavity for housing the image pickup device 3, and a glass plate 13b for sealing the cavity. The housing 13a is made of a ceramic material mainly composed of alumina, for example.

  As shown in FIG. 1, the image sensor 3 is mounted on the inner bottom surface of the package 13 via a bonding material 27. The thickness of the bonding material 27 changes so that the lower surface of the image sensor 3 and the inner bottom surface of the package 13 are inclined. In the example shown in FIG. 1, the bonding material 27 increases in thickness from the lower side to the upper side. As the bonding material 27, a resin material such as an epoxy resin, or solder is used.

  When the package 13 is mounted on the imaging substrate 4 as usual with such a configuration, the light receiving surface of the imaging device 3 is not parallel to the lens group 2 due to the non-uniform thickness of the bonding material 27. In order to suppress this, the following configuration is adopted.

  As shown in FIG. 1, the outer bottom surface of the package 13 is electrically connected to one main surface 4 </ b> A of the imaging substrate 4 via a plurality of solders 25. The plurality of solders 25 are provided with a difference in height so that the light receiving surface of the image sensor 3 is parallel to the lens group 2.

  In other words, the angle formed between the lower surface of the image sensor 3 and the inner bottom surface of the package 13 is the same as the angle formed between the outer bottom surface of the package and one main surface of the imaging substrate 4.

  According to these configurations, the light receiving surface of the image pickup device 3 tilted with respect to the lens group 2 can be corrected so as to be parallel to the lens group 2, so that an image output from the image pickup module 1 is clear. It becomes.

Here, the term “parallel” includes not only a completely parallel relationship but also a case where an inclination of 0.5 ° or less occurs. With this degree of inclination, there is no problem in the clarity of the output image of the imaging module 1.

  In order to provide a difference in height between the plurality of solders 25, for example, a method of providing a difference in the amount of solder paste supplied can be used. For example, if the supply amount of the solder paste is reduced, the diameter of the solder in the form of a ball is reduced, so that the height of the solder 25 is inevitably reduced. Conversely, when the amount of solder paste supplied increases, the height of the solder 25 increases.

  Next, changes in the height (diameter) of the plurality of solders 25 as viewed from the outer bottom surface of the package 13 will be described with reference to FIGS. 3 and 4.

  As shown in FIG. 3A, the thickness of the bonding material 27 provided on the inner bottom surface of the package 13 increases in the direction of arrow A (the direction parallel to the side of the imaging substrate 4). Therefore, in order to correct this, in the example shown in FIG. 3B, the height of the solder 25 decreases in the direction of the arrow A. As a result, the light receiving surface of the image sensor 3 can be made parallel to the lens 2 as described above.

  4A, the bonding material 27 provided on the inner bottom surface of the package 13 increases in thickness in the direction of arrow B (diagonal line direction of the imaging substrate 4). Therefore, in order to correct this, in the example shown in FIG. 4B, the height of the solder 25 decreases in the direction of the arrow B. More specifically, when the outer bottom surface of the package 13 is divided into nine areas 13a to 13l, the area 13g, the areas 13d and 13h, the areas 13a, 13e, and 13i, the areas 13b and 13f, and the area 13c are arranged in this order. The inner solder 25 is high. In this one area, for example, four solders 25 are provided.

  As shown in FIGS. 3 and 4, the heights of the plurality of solders 25 change so that the outer bottom surface of the package 13 and the one main surface 4 </ b> A of the imaging substrate 4 are inclined.

  In the above, the method of providing the height difference depending on the supply amount of the solder 25 has been described. However, when the inclination of the image pickup element 3 with respect to the lens group 2 can be predicted in advance, the package is adjusted to the inclination. The size of the surface area of the solder pads on the outer bottom surface 13 may be changed in advance. Thereby, even if the supply amount of the solder paste is constant, the height of the solder 25 inevitably changes as the width of the solder 25 changes. For example, if the solder 25 is desired to be high, the solder 25 can be formed small in the width direction and large in the height direction by reducing the surface area of the solder pad.

  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. 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 image sensor 2 is mounted on the inner bottom surface of the package 13 via the bonding material 27. As shown in FIG. 1, the bonding material 27 has a non-uniform thickness so that the lower surface of the image sensor 3 and the inner bottom surface of the package 13 are inclined with respect to each other. The part to which the bonding material 27 is applied in advance may be either the lower surface of the image sensor 2 or the inner bottom surface of the package 13.

  Next, the inclination between the lower surface of the image sensor 3 and the inner bottom surface of the package 13 due to the uneven thickness of the bonding material 27 is measured.

  Next, this inclination is corrected, and solder paste is applied while adjusting the amount so that the light receiving surface of the image sensor 3 and the lens group 2 are parallel. The part to which the solder paste is applied in advance may be either a solder pad (not shown) on the outer bottom surface of the package 13 or an electrode pad (not shown) on the one main surface 4A of the imaging substrate 4. . The solder paste is supplied by a dispenser or the like.

  Next, the solder paste is cured by heat to form solder 25, and the package 13 and the imaging substrate 4 are electrically connected. In order to apply heat, reflow or the like is used.

  Next, the imaging substrate 4 with the package 13 attached is fixed to the front case member 21. Specifically, first, the main board 4 is positioned by inserting the support member 24 into the through hole 4 a of the imaging board 4. At this time, a cable (not shown) 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 imaging 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 imaging substrate 4 is positioned based on the evaluation. In positioning, the position of the imaging substrate 4 in the optical axis direction with respect to the lens group 2, the inclination with respect to the optical axis, and the position in the direction orthogonal to the optical axis are adjusted. Thereafter, the imaging substrate 4 is fixed to the support member 24 with solder.

  Thereafter, 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.

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

  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, the attachment of the imaging substrate 4 to the case 5 is performed by the support member 24 in the example shown in FIG. 1, but a screw may be used as shown in FIG. In the example illustrated in FIG. 5, a cylindrical member 21 d that protrudes in the optical axis direction and has a screw hole is provided inside the front surface portion 21 a of the front side case member 21. A screw 28 for holding the main board 4 is fixed to the cylindrical member 21d. The screw 28 penetrates the through hole 4a of the imaging substrate 4, and the imaging substrate 4 is fixed by the screw thread and the end of the cylindrical member 21d.

  As shown in FIG. 6, the periphery of the imaging substrate 4 may be directly attached to the front case member 21. In the example shown in FIG. 6, the side part 21b of the front case member 21 is thick and protrudes toward the package 13 side. And the peripheral part of the imaging board | substrate 4 is attached to this protruding part in the front side case member 21. As shown in FIG. In the attachment, an adhesive material such as a resin material is used.

  Further, in the example shown in FIG. 1, the case where the thickness of the bonding material 27 is non-uniform is shown, but for example, as in the example shown in FIG. 7, the thickness of the bonding material 27 is uniform and the package 13 A configuration in which the inner bottom surface is inclined may be employed. Even in such a configuration, when the package 13 is mounted on the image pickup substrate 4 as usual, the light receiving surface of the image pickup device 3 is not parallel to the lens group 2, but both of them are caused by the difference in height of the plurality of solders 25. Can be parallel.

For example, as shown in FIG. 8, a plurality of lead members 26 may extend from the package 13 and may be fixed to one main surface of the imaging substrate 4 with solder or the like. The plurality of lead members 26 are provided with a difference in height so that the light receiving surface of the image sensor 3 is parallel to the lens group 2. Even with such a configuration, the light receiving surface of the image pickup device 3 tilted with respect to the lens group 2 can be corrected so as to be parallel to the lens group 2. Becomes clear.

1: Imaging module 2: Lens 3: Imaging element 4: Imaging substrate 5: Case 13: Package 25: Solder 26: Lead member 27: Bonding material

Claims (7)

A lens,
An image sensor on which light from the lens forms an image;
A package in which the image sensor is mounted on the inner bottom surface;
An imaging substrate to which the package is connected via a plurality of solders;
A case for holding the lens and the imaging substrate;
An imaging module comprising:
An imaging module, wherein a difference in height of the plurality of solders is provided so that a light receiving surface of the imaging element is parallel to a lens. The image sensor is mounted on the inner bottom surface of the package via a bonding material,
2. The imaging module according to claim 1, wherein a thickness of the bonding material is changed so that a lower surface of the imaging element and an inner bottom surface of the package are inclined. A lens,
An image sensor on which light from the lens forms an image;
A package in which the image sensor is mounted on the inner bottom surface;
An imaging substrate to which the package is connected via a plurality of lead members;
A case for holding the lens and the imaging substrate;
An imaging module comprising:
An imaging module, wherein a difference is provided in the length of the lead member such that a light receiving surface of the imaging element is parallel to the lens. The image sensor is mounted on the inner bottom surface of the package via a bonding material,
The imaging module according to claim 3, wherein a thickness of the bonding material is changed so that a lower surface of the imaging element and an inner bottom surface of the package are inclined. A lens,
An image sensor on which light from the lens forms an image;
A package in which the image sensor is mounted on the inner bottom surface;
An imaging substrate in which the package is connected to one main surface on the lens side;
A case for holding the lens and the imaging substrate;
An imaging module comprising:
The outer bottom surface of the package and the one main surface of the imaging substrate are inclined to each other,
The angle formed by the lower surface of the image sensor and the inner bottom surface of the package is the same as the angle formed by the outer bottom surface of the package and one main surface of the image pickup substrate. The image sensor is mounted on the inner bottom surface of the package via a bonding material,
The imaging module according to claim 5, wherein a thickness of the bonding material is changed so that a lower surface of the imaging element and an inner bottom surface of the package are inclined. The outer bottom surface of the package is connected to one main surface of the imaging substrate via a plurality of solders,
8. The imaging module according to claim 6, wherein the plurality of solders have different heights so that an outer bottom surface of the package and one main surface of the imaging substrate are inclined.

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