KR101037481B1 - Method of Fabricating Camera Module - Google Patents

Abstract

The present invention relates to a manufacturing method of a camera module, (a) the adhesive and the solder is mixed, the passive film to prevent the noise of the camera module is mounted on the upper surface of the solder film is attached to the protective film on both sides, Attaching to the center of the lower surface of the first substrate having electrode pads formed on the outer surface of the surface and the lower surface; (b) A semiconductor chip and a passive device for driving an image sensor are mounted, and the center portion of the upper surface of the second substrate on which the electrode pad is formed is formed outside the upper surface so as to match the electrode pad formed on the first substrate. Making a step; And (c) a pad formed at the center of the lower surface of the first substrate and the center of the upper surface of the second substrate by the adhesive, and formed outside the lower surface of the first substrate and the upper surface of the second substrate. And applying heat to the electrode pads formed on the first substrate and the second substrate while simultaneously applying pressure to the first substrate and the second substrate so that the pad formed on the substrate is bonded and fixed by the solder. Bonding force of the central portion of the second substrate is improved to prevent a poor opening of the pad during manufacture and handling of the camera module.

Solder Film, Camera, Adhesive

Description

Manufacturing Method of Camera Module {Method of Fabricating Camera Module}

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

Currently, the camera module (Compact Camera Module; CCM) is employed in most mobile mobile communication devices, such as camera phones, PDAs, smartphones.

Such a camera module is manufactured by using an image sensor such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) as a main component, and the camera module condenses an image of an object through an image sensor to store a memory in the device. Data is stored on the screen, and the stored data is displayed as an image through a display device such as an LCD or a PC monitor.

In general, a camera module is manufactured by a method such as a chip on board (COB), a chip on flexible (COF), a chip scale package (CSP), etc. At present, a COB method and a COF method having a relatively simple manufacturing structure are mainly used. .

At this time, the COB method is mainly applied to the standardization of the camera module, and is connected to the flexible printed circuit board by a hot-bar process using a solder or an anisotrofic conductive film (ACF). The production of is complete.

Although the COB method of manufacturing a camera module has been adopted as a standardized model because of low material cost and relatively simple manufacturing process, the flexible circuit board is bonded to connect to an external device. Due to the thermal deformation of the housing and the printed circuit board due to the thermocompression process is used for the change of the focal length and the optical axis, there is a disadvantage that the poor optical characteristics.

On the other hand, the COF type camera module does not need a space to attach the wire, the package area is reduced, and as the flexible printed circuit board is directly attached to the lower part of the housing, the height of the module can be lowered, thereby making it light and small. As the image sensor is attached to the lowermost side, additional circuit connection is not easy.

Hereinafter, the conventional camera module will be described in more detail with reference to the accompanying drawings.

1 is an exploded perspective view schematically showing a camera module according to the prior art.

As shown in FIG. 1, the camera module according to the related art includes a first substrate 112, a second substrate 110, an image sensor 114, an infrared cut-off filter 116, and a housing. 118 and the lens barrel 120.

Here, the first substrate 112 is composed of a rigid printed circuit board (RPCB), the second substrate 110 is a rigid flexible printed circuit board (RF-PCB) or flexible It consists of a Flexible Printed Circuit Board (FPCB).

In addition, passive elements for preventing noise of the camera module are mounted on an upper surface of the first substrate 112, and a plurality of electrode pads 110a connected to the second substrate 110 are formed outside the lower surface. do.

In addition, passive elements such as capacitors and resistors for driving the image sensor 114 and various electronic components such as semiconductor devices are mounted on the second substrate 110, and the first substrate 112 is disposed outside the upper surface. A plurality of electrode pads 112a are formed at portions corresponding to the electrode pads 110a formed in the substrate.

The camera module according to the related art having such a configuration has a structure in which the pad 112a formed on the lower portion of the first substrate 112 and the pad 110a formed on the upper portion of the second substrate 110 coincide with each other. After arranging the second substrate 110 in the lower portion, the pads 110a and 112a are bonded with solder to fix the first substrate 112 on the second substrate 110 to manufacture a camera module.

However, when the first substrate 112 and the second substrate 110 is fixed in this manner, the bonding force is not present at the center of the second substrate 110 and the first substrate 112. When an external shock occurs when the camera module is handled, an open (ie, short) defect of the pads 110a and 112a may be caused by an external shock.

Accordingly, in order to solve the above problems, the present invention arranges a solder film mixed with an adhesive and a solder between the first and second substrates, and then adheres the center portion of the first and second substrates with a solder film. It is an object of the present invention to provide a method for manufacturing a camera module that can prevent an open failure of a pad during manufacture and handling of the camera module by improving the bonding force at the center portion.

In the manufacturing method of the camera module according to the embodiment of the present invention (a) the adhesive and the solder is mixed, the passive film to prevent the noise of the camera module on the upper surface of the solder film is attached to the protective film on both sides, Attaching to a lower surface of the first substrate having electrode pads formed around the upper surface and the lower surface; (b) A semiconductor chip and passive devices for driving an image sensor are mounted, and the upper surface of the second substrate on which the electrode pad is formed outside the upper surface is attached to the solder film so as to match the electrode pad formed on the first substrate. step; And (c) a pad formed at the center of the lower surface of the first substrate and the center of the upper surface of the second substrate by the adhesive, and formed outside the lower surface of the first substrate and the upper surface of the second substrate. And applying heat to the electrode pads formed on the first substrate and the second substrate while simultaneously applying pressure to the first substrate and the second substrate so that the pad formed on the substrate is bonded and fixed by the solder.

In the method of manufacturing a camera module according to an embodiment of the present invention, the step (a) includes: (a-1) removing the protective film attached to one surface of the solder film; And (a-2) attaching the surface from which the protective film is removed to the lower surface of the first substrate.

In the method of manufacturing a camera module according to an embodiment of the present invention, the first substrate is composed of a rigid printed circuit board, and the second substrate is composed of any one of a flexible printed circuit board or a flexible printed circuit board.

According to an embodiment of the present invention, a solder film in which an adhesive and a solder are mixed is disposed between a first substrate and a second substrate, and then bonded and fixed to a central portion of the first substrate and a second substrate with an adhesive, and formed on the first substrate with solder. Since the electrode pad and the electrode pad formed on the second substrate are bonded to each other, the bonding force of the central portion of the first substrate and the second substrate is improved, thereby preventing the failure of opening of the pad during manufacture and handling of the camera module.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is an exploded perspective view illustrating a method of manufacturing a camera module according to an exemplary embodiment of the present invention, and FIGS. 3 to 6 are exploded views illustrating an assembly process of a first substrate, a solder film, and a second substrate illustrated in FIG. 2. Perspective view.

As shown in Figure 2 to 6, the camera module according to an embodiment of the present invention is the first substrate 12, the solder film 30, the second substrate 10, the image sensor 14, the infrared cut filter 16, the housing 18 and the lens barrel 20.

In the camera module having the above-described configuration, first, passive elements for preventing noise of the camera module are mounted on an upper surface thereof, and a first substrate having a plurality of electrode pads 12a formed on the outer side of the upper surface and the outer side of the lower surface ( 12), an adhesive such that the adhesive 30b and the solder 30a are mixed, the solder film 30 with the protective film 30c attached to both sides of the adhesive portion, and an electronic chip such as a semiconductor chip for driving the image sensor 14. Passive elements such as components, capacitors, and resistors are mounted, and a second substrate having a plurality of electrode pads 10a formed at a portion corresponding to the electrode pads 12a formed on the first substrate 12 on the outer side of the upper surface ( 10) Prepare.

At this time, the first substrate 12 is composed of a rigid printed circuit board (RPCB), the second substrate 10 is composed of either a flexible printed circuit board (RF-PCB) or a flexible printed circuit board (FPCB). .

As such, when the first substrate 12, the solder film 30, and the second substrate 10 are prepared, the solder film 30 and the second substrate 12 are disposed below the first substrate 12 as shown in FIG. 3. The board | substrate 10 is arrange | positioned sequentially.

In this case, the second substrate 10 is disposed below the first substrate 12 such that the electrode pad 10a formed on the outer side of the upper surface matches the electrode pad 12a formed on the first substrate 12.

After the first substrate 12, the solder film 30, and the second substrate 10 are disposed as described above, one surface of the protective film 30c attached to both surfaces of the solder film 30 (that is, the first substrate 12). The protective film 30c attached to the substrate 12 facing the substrate 12 is removed.

Thereafter, as shown in FIG. 4, the portion from which the protective film 30c is removed is attached to the lower surface of the first substrate 12.

In this case, the solder film 30 is attached to the lower surface of the first substrate 12 to cover all of the pads 12a formed on the first substrate 12.

As such, after the solder film 30 is attached to the lower surface of the first substrate 12, the protective film 30c remaining on one surface of the solder film 30 is removed.

Thereafter, the second substrate 10 is brought into close contact with the solder film 30 to attach the upper surface of the second substrate 10 to the solder film 30 as shown in FIG. 5.

In this case, the solder film 30 is attached to the upper surface of the second substrate 10 to cover all of the pad 10a formed on the upper surface of the second substrate 10.

After attaching the solder film 30 to the lower surface of the first substrate 12 and the upper surface of the second substrate 10, the pressure is applied to the first substrate 12 and the second substrate 10 simultaneously. Heat is applied to the electrode pads 10a and 12a formed on the first substrate 12 and the second substrate 10.

Accordingly, as shown in FIG. 6, the center of the lower surface of the first substrate 12 and the center of the upper surface of the second substrate are bonded and fixed by the adhesive 30b to the first substrate 12. The formed electrode pad 12a and the electrode pad 10a formed on the second substrate 10 are bonded and fixed by the solder 30a.

That is, when pressure is applied to the first substrate 12 and the second substrate 10 and heat is applied to the electrode pads 10a and 12a formed on the first substrate 12 and the second substrate 10, the adhesive ( The solder 30a mixed with 30b is removed from the adhesive part by the heat applied to the electrode pads 10a and 12a and attached to the electrode pads 10a and 12a as shown in FIG. 6.

As a result, the electrode pads 10a and 12a are bonded and fixed by the solder 30a.

At this time, the portions in which the solder 30a is removed are filled with the adhesive 30b.

Thus, the adhesive 30b is attached between the pad 10a or 12a and the pad 10a or 12a as shown in FIG. 6 to bond the central portion of the first substrate 12 and the second substrate 10 to each other.

Here, the method for attaching the solder film 30 to the lower portion of the first substrate 12 after sequentially placing the solder film 30 and the second substrate 10 in the lower portion of the first substrate 12. Although described, the second substrate 10 may be disposed below the first substrate 12 after the solder film 30 is attached to the bottom surface of the first substrate 12.

In addition, the solder film 30 is first attached to the lower surface of the first substrate 12, but is first attached to the upper surface of the second substrate 10, and then the first substrate on the upper portion of the solder film 30 The lower surface of (12) may be attached.

After bonding the first substrate 12 and the second substrate 10 in this manner, it is made of CCD or CMOS, and converts the light introduced through the infrared cut filter 16 through the lens group L into an electrical signal. The image sensor 14 is installed on the upper surface of the first substrate 12 by flip chip bonding.

That is, the electrode pads formed outside the upper surface of the first substrate 12 and the electrode pads formed outside the lower surface of the image sensor 14 are connected by a flip chip bonding method.

In this case, in the step of installing the image sensor 14 on the upper surface of the first substrate 12, the second substrate 10 is installed below the first substrate 12 through the method as illustrated in FIGS. 3 to 6. The step may be performed before the step or after the second substrate 10 is bonded to the lower portion of the first substrate 12.

As such, after the image sensor 14 is installed on the upper surface of the first substrate 12, the image sensor module including the first substrate 12, the second substrate 10, and the image sensor 14 is replaced. A lens barrel 20 composed of a plurality of lenses L is installed at a lower portion of the housing 18 coupled therein by screwing.

In this case, an infrared cut filter 16 is installed at a lower step portion of the housing 18 to block infrared light having a long wavelength included in the light flowing into the image sensor 14, and the image sensor module is provided with the image sensor 14. ) Is installed in the lower portion of the housing 18 so that the upper portion thereof is disposed under the infrared cut filter 16.

As such, when assembling the image sensor module to the housing 18, a lens barrel 20 in which an aperture, a condenser lens, and the like are assembled from an upper opening is pre-mounted in the housing 18, or the image sensor module is attached to the housing 18. After assembling in the housing 18, the lens barrel 20 may be mounted in the housing 18.

That is, after assembling the housing 18 and the image sensor module first, the lens barrel 20 is assembled to the housing 18 by a screw method, or the lens barrel 20 is assembled to the housing 18 by a screw method. The image sensor module may be assembled in the housing 18.

As described above, in the method of manufacturing the camera module according to the embodiment of the present invention, the solder film 30 having the adhesive 30b and the solder 30a mixed is disposed between the first substrate 12 and the second substrate 10. After the adhesive 30b, the center of the lower surface of the first substrate 12 and the center of the upper surface of the second substrate 10 are bonded and fixed, and the electrode pads 12a formed on the first substrate 12 by solder 30a. ) And the electrode pads 10a formed on the second substrate 10 are bonded to each other to fix the center pads of the first and second substrates 12 and 10 to improve the bonding strength of the camera module. It is possible to prevent the open failure of the.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and various substitutions, modifications, and changes within the scope of the technical spirit of the present invention for those skilled in the art to which the present invention pertains. Changes may be made, but such substitutions, changes and the like should be regarded as belonging to the following claims.

1 is an exploded perspective view for illustrating a method of assembling a camera module according to the prior art.

2 is an exploded perspective view illustrating a method of manufacturing a camera module according to an embodiment of the present invention.

3 to 6 are exploded perspective views illustrating an assembly process of the first substrate, the solder film, and the second substrate illustrated in FIG. 2.

<Description of the symbols for the main parts of the drawings>

10, 12, 110, 112: substrate 10a, 12a, 110a, 112a: electrode pad

14, 114: image sensor 16, 116: infrared cut filter

18, 118: housing 20, 120: lens barrel

30: solder film 30a: solder

30b: adhesive 30c: protective film

Claims (3)

(A) Passive elements are mounted to prevent the noise of the camera module on the upper surface of the solder film is mixed with the adhesive and solder, the protective film is attached on both sides, and the electrode pad is formed on the upper and outer edges 1 attaching to the bottom surface of the substrate; (b) A semiconductor chip and passive devices for driving an image sensor are mounted, and the upper surface of the second substrate on which the electrode pad is formed outside the upper surface is attached to the solder film so as to match the electrode pad formed on the first substrate. step; And  (c) a center portion of the lower surface of the first substrate and a center portion of the upper surface of the second substrate are bonded and fixed to each other by the adhesive, and formed on the outside of the upper surface of the pad and the upper surface of the second substrate. And applying heat to electrode pads formed on the first and second substrates while simultaneously applying pressure to the first and second substrates so that the formed pads are bonded and fixed by the solder. Method of preparation. The method according to claim 1, In step (a), (a-1) removing the protective film attached to one surface of the solder film; And (a-2) The method of manufacturing a camera module, further comprising the step of attaching a surface from which the protective film is removed to the lower surface of the first substrate. The method according to claim 1, The first substrate is composed of a rigid printed circuit board, the second substrate is a manufacturing method of a camera module, characterized in that composed of any one of a flexible printed circuit board or a flexible printed circuit board.

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