JP4346077B2 - Assembly method for small imaging module - Google Patents

Description

  The present invention relates to a method for assembling a small imaging module.

  An imaging device incorporated in a digital camera, a notebook computer with a camera, a mobile phone, or the like includes a solid-state imaging device and components such as a circuit board, a lens, a lens holder, and a filter. In the process of assembling the imaging device, the positional relationship between optical components such as lenses and filters and the solid-state imaging device must be finished with high accuracy. In particular, a compact imaging module is used for a camera-equipped mobile phone or the like. For example, when the solid-state imaging device has a level of 100,000 pixels, it appears to be in focus even if the focal position is shifted by about 50 μm, but 300,000 pixels. If it is above, the image appears blurred when it is shifted by about 20 μm. Therefore, as a device for ensuring the positional relationship with high accuracy, a device in which the deposition position of an integrated circuit, which is a solid-state image sensor, is variable has been devised (see, for example, Patent Document 1).

  The configuration of such a conventional small imaging module will be described with reference to the drawings. FIG. 4 is a perspective view of a conventional small imaging module, and FIG. 5 is a sectional view of the same. 4 and 5, 51 is a small imaging module, and 52 is a holder made of a resin molded product which is a housing of the small imaging module 51. The holder 52 includes a cylindrical portion 53 having an upper and lower opening and a rectangular circuit portion 54 continuous from the lower end of the cylindrical portion 53.

  A screw 52a is formed at the inner periphery of the cylindrical portion 53, and a stepped portion 52b is formed at the lower portion thereof. In the circuit portion 54, wiring is formed from the inner surface 52c to the lower end surface 52d. Reference numeral 61 denotes a barrel for holding an optical component. The barrel 61 has an end face having an aperture 61a at one end, and a screw 61b is formed on the outer periphery of the cylindrical portion. Reference numeral 10 denotes a first lens incorporated in the barrel 61. A ring-shaped pressing member 62 is fixed to the inner periphery of the barrel 61 by pressing the second lens 8 from the outside.

  Reference numeral 59 denotes an annular light shielding member sandwiched between the first lens 10 and the second lens 8, which is made of a film such as PET or PC, or a metal plate such as Al or SUS, and adjusts the amount of light passing through the lens. This is for blocking light passing through a portion other than the spherical surface. Reference numeral 6 denotes a filter that cuts infrared rays (Ir) fixed to the inner peripheral step 52b.

  Reference numeral 5 denotes an IC which is a solid-state imaging device, and reference numeral 15 denotes a bump formed on the pad portion of the IC 5. The IC 5 is mounted on the connection electrode (not shown) on the inner surface 52 c of the circuit unit 54 via the bump 15. The circuit portion 54 is formed with a wiring pattern that conducts from the connection electrode to a terminal electrode formed on the lower end surface 52d.

  Next, a method for assembling the small imaging module 51 will be described. First, the IC 5 is mounted on the holder 52. Next, the filter 6 is assembled in the inner peripheral step portion 52b of the holder 52 and fixed by adhesion. On the other hand, the first lens 10, the light shielding member 59, and the second lens 8 are sequentially assembled in the barrel 61, and then the second lens 8 is pressed and fixed from the outside by the pressing member 62. Next, the screw part 61 b of the barrel 61 is screwed into the screw part 52 a of the holder 52. To adjust the focus, the small imaging module 51 is attached to the circuit board of a dedicated adjustment device, and the barrel 61 is turned one by one while finely adjusting the monitor image while checking the monitor image. After adjustment, the screwed part is adhered and fixed.

In the small imaging module 51 described above, the incident light that has passed through the diaphragm 61a is refracted through the first lens 10 and the second lens 8, the infrared ray is cut by the filter 6, and the solid-state imaging device surface that is the surface of the IC 5 Tie the image to.
JP 2001-333332 (page 2-3, FIG. 1)

  However, a multi-piece mold is used for forming the lens. Therefore, the size of the molded lens can ensure sufficient accuracy for lenses from the same cavity, but varies between different cavities. The device of Patent Document 1 cannot cope with this problem. Therefore, it is necessary to adjust the focal position. In the case of the small image pickup module 51, the number of parts is increased due to the two housings, the number of processing steps is increased, and the parts cost is increased. In addition, assembly and focus adjustment require a lot of man-hours, increasing the cost of the product.

  The present invention has been made to solve such a conventional problem, and an object of the invention is to provide a method for assembling a small imaging module that can reduce the cost by eliminating the focus adjustment and improving the productivity. It is to be.

Means of the present invention for achieving the above object, the method of assembling compact imaging module with a fixed IC is an optical component and the solid-state imaging device in the housing including a lens and filter, wherein the lens is a plurality of cavities Is formed with a multi- cavity mold, and before assembling each of the parts, a focus is placed on the solid-state imaging device corresponding to each lens formed from the same cavity in advance using an adjustment tool. The thickness dimension of the filter is set experimentally so as to tie, and after that , the first step portion and the second step portion are formed in the cylindrical portion first, which is the opposite surface of the second step portion of the holder. and mounting the IC to the inner surface, then Nde write set the filter size set in advance to the second stage portion from the upper opening of the holder is bonded and fixed, the the first step portion second shielding member, the Two lenses, first shield Incorporate member and the first lens in order, characterized in that holds and fixes the first lens from the outside at the end stop.

According to the present invention, in an assembling method of a small imaging module in which an optical component including a lens and a filter and an IC that is a solid-state imaging device are fixed to a housing, the adjustment tool is used in advance before assembling the components. Since the thickness dimension of the filter is experimentally set so as to focus on the solid-state image sensor corresponding to the lens, and then the filter having a preset dimension is incorporated, the adjustment step This eliminates the need to reduce the cost of the small imaging module.

  Hereinafter, a method for assembling a small image pickup module according to the best embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a small imaging module to which the assembling method of the present invention is applied.

  First, the configuration of a small imaging module to which the assembling method of the present invention is applied will be described. In FIG. 1, the same reference numerals and names are used for the same constituent elements as in the prior art, and description thereof is omitted. Reference numeral 1 denotes a small imaging module. 2 is a holder, 3 is a cylindrical part which comprises the holder 2, and the 1st step part 2a and the 2nd step part 2b are formed in the cylindrical part 3. As shown in FIG. A filter 6 is fixed to the second stage 2b.

  Reference numeral 7 denotes an annular second light shielding member similar to the light shielding member 59, and is fixed to the first step portion 2a. A second lens 8, a first light shielding member 9, and a first lens 10 are incorporated in that order, and 11 is a stop, which is fixed to the cylindrical portion 3 while pressing the outside of the first lens 10.

  Next, a method for assembling the small imaging module 1 according to the embodiment of the present invention will be described. To assemble the small imaging module 1, first, the IC 5 is mounted on the inner surface 2 c of the holder 2. Next, the optical components are sequentially inserted from the upper opening of the holder 2 and assembled. First, the filter 6 is assembled and fixed to the second step 2b. Next, after the second light shielding member 7, the second lens 8, the first light shielding member 9, and the first lens 10 are sequentially assembled in the first step portion 2 a, the first lens 10 is pressed from the outside by the diaphragm 11. Assembly is completed by fixing.

  However, the first lens 10 and the second lens 8 incorporated here are known from which cavity of a multi-cavity mold. Further, each of the first light shielding member 9, the second light shielding member 7 and the filter 6 functions as a focus adjustment member at least independently, and the thickness dimension of each of the first light shielding member 9, the second light shielding member 7 and the filter 6 has been set in advance experimentally before incorporation. Is.

  Here, focusing in this assembling method will be described. FIG. 2 is an explanatory diagram for explaining the principle of focus adjustment. FIG. 3 is a partially enlarged view in which the portion A of FIG. 2 is enlarged. In FIG. 2, reference numeral 20 denotes a test chart surface. Light emitted from the chart surface 20 passes through the first lens 10, the first light shielding member 9, the second lens 8, the second light shielding member 7, and the filter 6, and the IC5 surface. Tie the image to. In FIG. 3, for example, when the thickness W of the filter 6 is W1, the focus is set on the position P1. If the conditions of the other parts are constant, when the thickness W is W2 indicated by a dotted line, the optical path length of the lens changes to focus on the position P2 indicated by the dotted line.

  Therefore, when the IC5 surface is at the position P1, the thickness W of the filter 6 may be set to W1, and when the IC5 surface is at the position P2, the thickness W of the filter 6 may be set to W2. In this way, the focal position can be adjusted by experimentally setting an appropriate thickness of the filter 6 in advance corresponding to the lens formed by a specific cavity of the multi-cavity mold. Further, the focal length can be adjusted by appropriately setting the thickness of the first light shielding member 9 or the second light shielding member 7 instead of the filter 6.

  The effect of this embodiment will be described. As described above, the thickness of each of the focus adjustment members is experimentally set in advance using an adjustment tool before assembling, and the focus is adjusted in a predetermined size for each lens combination during assembly. Since the members are selected and combined, the number of parts of the small imaging module can be reduced, and the post-assembly focus adjustment process, which has conventionally been required, can be omitted. Accordingly, it is possible to automatically assemble a small imaging module.

  In the above description, two lenses have been described. However, the number of lenses is not necessarily limited to two. The first light shielding member is sandwiched between a plurality of lenses, and the second light shielding member is sandwiched between the inner peripheral step portion of the housing and the lens.

  The method for assembling a small image pickup module of the present invention is not limited to the small image pickup module of the present embodiment, and can be widely applied to various other image pickup apparatuses.

It is sectional drawing which shows the small imaging module to which the assembly method of this invention is applied. It is explanatory drawing explaining the principle of the focus adjustment in the assembly method of the small image pick-up module which is embodiment of this invention. It is the elements on larger scale which expanded the A section of FIG. It is a perspective view of the conventional small image pick-up module. It is sectional drawing of the conventional small imaging module.

Explanation of symbols

1 Small imaging module 2 Holder 5 IC
6 Filter 7 Second light shielding member 8 Second lens 9 First light shielding member 10 First lens

Claims (1)

In a method for assembling an optical component including a lens and a filter, and a small imaging module in which an IC that is a solid-state imaging device is fixed to a housing, the lens is molded by a multi-cavity mold including a plurality of cavities. the as to correspond to each of the lens molded from the same cavity using preconditioned device prior to assembly of the parts focused on the solid-experimentally the thickness dimension of the filter First , after mounting the IC on the inner surface which is the opposite surface of the second step portion of the holder in which the first step portion and the second step portion are first formed in the cylindrical portion, Nde write from the opening set the filter size set in advance to the second stage portion is bonded and fixed, the the first stage unit incorporating the second shielding member, the second lens, the first light shielding member and the first lens in order And finally Method of assembling compact imaging module, characterized in that holds and fixes the Ride the first lens from the outside.

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