KR100854748B1 - Camera module - Google Patents

Abstract

A camera module is provided to prevent a flow of a foreign substance in a screw joining portion in assembling a housing and a lens barrel and adjusting a focus, and enable the foreign substance flowing in the assembled camera module to be absorbed into an adhesive coated with the internal circumference, thereby preventing a black point or a color point caused by the foreign substance fundamentally. A camera module(100) includes a lens barrel(130), a lens fixing cap(150), a housing(120), and a substrate(110). A lens insertion hole(132) is formed in the lens barrel to mount at least one lens(140) in the central portion. The lens barrel has a circular groove. A female screw portion is formed in the internal circumference of the lens barrel to the outside of the lens insertion hole. The lens fixing cap covers the upper portion of the lens barrel and supports the upper surface of the lens. The housing is inserted into the circular groove of the lens barrel. A barrel joining portion(121) is upward extended from the housing. A male screw portion(121a) is formed in the barrel joining portion to be joined to the female screw portion. The substrate is closely attached to the lower portion of the housing. An image sensor(111) is mounted to the substrate to pick up light passing through the lens. An adhesive is coated with the internal wall surface of the housing and the lens barrel to absorb a foreign substance.

Description

Camera module

1 is an exploded perspective view of a camera module manufactured by a conventional COB method.

Figure 2 is a schematic cross-sectional view of a conventional COB type camera module.

3 is a cross-sectional view of another conventional camera module.

4 is an assembled perspective view of the camera module according to the present invention.

5 is a cross-sectional view of the camera module according to the present invention.

6 is a cross-sectional view of another embodiment of a camera module according to the present invention;

7 is a cross-sectional view of the adhesive is applied to the camera module according to the present invention.

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

110. Substrate 111. Image Sensor

120. Housing 121. Barrel Coupling

121a. Male thread 130. Lens barrel

131. Circular groove 132. Lens insert

133.Rib 140.Lens

IR filter layer 150.Lens fixing cap

The present invention relates to a camera module manufactured in a wire bonding (COB) or flip chip (COF) type using a wafer lens, and more particularly, miniaturization of a camera module as a wafer lens is adopted. The present invention relates to a camera module that enables thinning and prevents inflow of foreign matters by allowing screwing to be made on the outside of the housing, and an adhesive is applied to the inner circumferential surface of the housing and the lens barrel to allow adsorption of fluid foreign matters.

Currently, camera modules are installed in the production of automobiles and endoscopes, including mobile communication terminals, IT devices such as PDAs and MP3 players, and these camera modules are centered on high pixels with the development of technology at 300,000 pixels (VGA level). At the same time, miniaturization and thinning are being progressed according to the mounting target, and various additional functions such as auto focusing (AF) and optical zoom (OPTICAL ZOOM) are being implemented at low cost.

In addition, the current camera module is equipped with an image sensor module manufactured by a wire bonding method (COB; chip of board), flip chip method (COF; Chip Of Flexible) and chip scale package (CSP) It is mainly manufactured in the form of being connected to the main board through electrical connection means such as a printed circuit board (PCB) or a flexible printed circuit board (FPCB).

In such a camera module, an image sensor such as a CCD or a CMOS is mainly manufactured in a state of being attached to a substrate by a wire bonding or flip chip method. The data is stored on the image, and the stored data is converted into an electrical signal and displayed as an image on a display medium such as an LCD or a PC monitor in the device.

A brief structure of the COB method, which is a typical camera module manufacturing method, will be described below with reference to the drawings shown below.

FIG. 1 is an exploded perspective view of a camera module manufactured by a conventional COB method, and FIG. 2 is a cross-sectional view schematically illustrating a camera module of a conventional COB method. The conventional camera module 1 includes an image sensor 2 of a CCD or a CMOS. The lens barrel in which the printed circuit board B mounted by the wire bonding method is coupled to the lower portion of the plastic housing 3 and the cylindrical body 5 extends downward in the barrel 4 extending above the housing 3. (6) is produced by the combination.

The camera module 1 is a screw combination of the female threaded portion 4a formed on the inner circumferential surface of the barrel 4 and the male threaded portion 5a formed on the outer circumferential surface of the cylindrical body 5 so that the housing 3 and the lens barrel 6 mutually interact with each other. Combined.

At this time, the IR filter 8 is disposed between the upper surface of the printed board B, that is, the lens L mounted on the lower end of the lens barrel 6 and the image sensor 2 attached to the lower surface of the printed board B. By being combined, the infrared rays of excessive long wavelength flowing into the image sensor 2 are blocked.

In the camera module assembled as described above, light flowing from a specific object passes through the lens L, and the image is inverted to focus on the surface of the image sensor 2, where the screw is coupled to the upper end of the housing 3. While rotating the lens barrel 6, the adhesive is injected between the clearance between the housing 3 and the lens barrel 6 at the point where the optimal focus is achieved, and the housing 3 and the lens barrel 6 are adhesively fixed to the final camera. Modular products are produced.

However, the lens barrel 6 screwed to the housing 3 to adjust the focus of the image on the image sensor 2 after assembling the lens barrel 6 with the lens L mounted thereon with the housing 3. When rotating vertically by rotating left and right, foreign substances such as particles generated by friction between the screw coupling portion of the housing 3 and the lens barrel 6 are transferred to the upper surface of the IR filter 8 or the image sensor 2. There is a disadvantage in that a foreign material defect occurs as it is exposed on the light receiving area of the image sensor 2 apart.

As such, the particles P generated between the housing 3 and the lens barrel 6 are forced to enter the upper surface of the IR filter 8 or the light receiving region of the image sensor 2. Problems that act as defects such as black spots or color spots have been pointed out when reproducing images.

The camera module for solving such a problem has been filed and disclosed by the present applicant (Korean Patent Publication No. 2006-94247), briefly look at the structure as follows.

3 is a cross-sectional view of a conventional camera module, the lens group 10 having at least one lens as shown, and the entrance hole having an inner space so that the lens group 10 is arranged along the optical axis and opened in the front center The housing 30 and the lens group having a lens receiving portion 20 and a male screw portion 30a coupled to a female screw portion 23a formed on an inner surface of the lens receiving portion 20 on an outer circumferential surface of the body. An image area in which light passing through 10 is formed is formed, and an image sensor 40 is formed, and a filter member 50 is disposed between the lens group 10 and the image sensor 40.

The camera module having such a configuration is provided with a lens accommodating part 20 which is inserted into the housing 30 so that the lens 10 inserted therein is aligned along the optical axis, and for fixing the lens 10. Since the cylindrical lens accommodating part 20 must be separately provided, assembly is not easy, and the width of the module must be increased by the thickness of the lens accommodating part 20. have.

Therefore, the present invention was devised to solve the above-mentioned disadvantages and problems raised in the conventional camera module, and prevents the inflow of foreign substances generated at the screw coupling portion during assembly and focusing of the housing and the lens barrel, and internal flow. It is an object of the present invention to provide a camera module which can prevent black spots or color spots caused by foreign matters, thereby improving image quality and improving product reliability by allowing foreign substances to be adsorbed on the adhesive applied to the inner circumferential surface.

The above object of the present invention is a lens barrel having a lens insertion hole in which at least one lens is mounted at a central portion thereof, and having a circular groove having a female threaded portion formed on an inner circumferential surface of the lens insertion hole, and an upper surface of a wafer lens on the lens barrel. A lens fixing cap which is supported and covered with a cap, a barrel coupling portion inserted into a circular groove of the lens barrel, and a barrel coupling portion having a male thread portion to be screwable with the female screw portion, and tightly coupled to a lower portion of the housing; And a camera module including a substrate on which an image sensor having a light-receiving area in which light passing through the wafer lens is imaged on an upper surface thereof is provided.

The housing and the lens barrel are tightly coupled by screwing the male screw portion formed in the outer circumferential surface of the barrel engaging portion and the female screw portion formed in the circular groove, respectively, and focusing is achieved by rotating the lens barrel about the screw engaging portion.

In addition, the lens barrel has a rib extending into the lens insertion hole in the center portion of the lower surface of the lens to be inserted therein is supported.

At this time, the lens is an IR coating lens that is deposited or coated on one surface of the IR filter layer is employed.

In addition, the lens may be a wafer lens having an IR filter layer on one surface.

The wafer lens is manufactured by injection molding through a replica method at a wafer level, and is cut into a rectangular unit wafer lens and mounted inside the lens barrel.

The image sensor mounted on the substrate is manufactured by a wire bonding (COB) method using a wire.

In addition, the image sensor mounted on the substrate is manufactured in a flip chip (COF) method.

Matters relating to the operational effects including the technical configuration of the camera module according to the present invention will be clearly understood by the following detailed description with reference to the drawings showing preferred embodiments of the present invention.

First, Figure 4 is an assembled perspective view of the camera module according to the present invention, Figure 5 is a cross-sectional view of the camera module according to the invention, Figure 6 is a cross-sectional view of another embodiment of the camera module according to the present invention, Figure 7 is the present invention The cross-sectional view of the adhesive is applied to the camera module according to.

As shown, the camera module 100 of the present invention is a housing 120 is coupled to the substrate 110 mounted with the image sensor 111 at the bottom, and a lens barrel coupled to the upper portion of the housing 120 ( 130).

The housing 120 is formed in an enclosure having an open lower portion, and a cylindrical barrel engaging portion 121 is formed to extend upward, and an external thread portion 121a is provided on an outer circumferential surface of the barrel engaging portion 121.

The inner wall surface of the housing 120 is configured to have a thickness that becomes thinner toward the bottom, which is a substrate 110 coupled to the lower portion of the housing 120 and an image sensor 111 mounted on the substrate 110. This is to secure the wire bonding position with), which will be described in more detail later.

The lens barrel 130 coupled to the housing 120 is configured to have a cylindrical shape so as to be compatible with the barrel coupling portion 121 of the housing 120, and the barrel coupling portion 121 is vertically transportable therein at a lower surface thereof. Circular groove 131 is provided.

The depth of the circular groove 131 may be formed to a depth corresponding to the length of the barrel coupling portion 121, it may be formed to a depth within the transfer range of the upper end of the barrel coupling portion 121.

In addition, the lens barrel 130 is provided with a lens insertion hole 132 in which the lens 140 is employed at the center portion, and a rib 133 extending inwardly is formed at the lower portion of the lens insertion hole 132 so that the lens insertion hole is formed. Supports the bottom surface of one or more lenses 140 stacked on 132.

Here, the lens insertion hole 132 may vary according to the shape of the lens 140. In the case of a general injection lens, the lens insertion hole 132 may be formed in a circular shape, and in the case of a wafer lens, the lens insertion hole 132 may be formed of a rectangular groove or hole.

In this case, the lens 140 mounted in the lens insertion hole 132 is an IR coating lens coated with an IR filter layer 141 on one of an upper surface or a lower surface, or is manufactured in an array form at a wafer level and dicing into individual rectangular lenses. Wafer lenses may optionally be employed.

Like the IR coating lens, the wafer lens is deposited or coated with an IR filter layer 141 on one surface of the upper and lower surfaces.

On the other hand, the lens fixing cap 150 of the circular ring shape is coupled to the upper portion of the lens barrel 130 so that the external light is incident only through the central portion of the lens 140 at the same time as the lens 140 is fixed.

The lens fixing cap 150 allows the lens 140 to be firmly fixed by compressing the upper surface of the lens 140 by the lens support 151 of the inner ring, and the upper surface of the lens barrel 130. The adhesive injected into the adhesive injection groove 134 formed therein is fixed by curing.

In addition, the lens fixing cap 150 is preferably formed of a black-based material so that light is not penetrated through the portion except the opening of the central portion.

The lens barrel 130 in which the lens 140 and the lens fixing cap 150 are mounted is fixed by screwing the male screw portion 121a and the female screw portion 131a in the upper portion of the housing 120. The lens barrel 130 is rotated at an upper portion thereof so that the lens barrel 130 is moved up and down along the screw coupling portion, thereby adjusting the gap between the lens 140 and the image sensor 111 thereunder.

In this case, as the screw coupling of the housing 120 and the lens barrel 130 is made on the outer circumferential surface of the housing 120, foreign matter that may be generated at the screw coupling portion may be introduced into the camera module 100. Is prevented.

In addition, the foreign material flowing inside the camera module 100 is adsorbed to the inner wall surface of the housing 120 and the lower surface of the lens barrel 130, that is, the portion indicated by the dotted line in the cross-sectional view of the camera module illustrated in FIG. 9. The adhesive 160 is coated.

Accordingly, when the housing 120 and the lens barrel 130 are assembled, fine foreign matter that may be introduced into the housing 120 is adsorbed onto the surface of the pressure-sensitive adhesive 160 during the flow in the camera module 100, thereby causing The defect is blocked at the source.

Here, the male screw portion 121a and the female screw portion 131a formed for the coupling of the housing 120 and the lens barrel 130 are adapted to achieve a smooth focus adjustment when the upper and lower portions of the lens barrel 130 are transferred. At least 3 pitches should be threaded.

This, when the lens barrel 130 is coupled to the upper portion of the housing 120, the upper end of the barrel coupling portion 121 of the housing 120 is in close contact with the lower surface of the lens barrel 130 to adjust the focus in one direction rotation When this is done, it is to find the correct focusing position with a sufficient conveying distance within the focusing distance of the lens 140.

Therefore, it is preferable that each thread pitch of the screw engagement portion has a minimum pitch of 3 in a state not exceeding the design height of the camera module, and is formed to 0.3 μm in consideration of the focusing distance thereof.

The substrate 110 on which the image sensor 111 is mounted is tightly coupled to the lower portion of the housing 120, and is fixed by an adhesive interposed between the lower end of the housing 120 and the upper surface of the substrate 110.

At this time, the image sensor 111 mounted on the substrate 110 is mounted by a wire bonding method using a wire or by a flip chip method using an anisotrofic conductive film (ACF) as shown in FIG. 6 shown below. It is tightly coupled to the upper and lower surfaces of).

The image sensor 111 is mounted to have a predetermined distance from the lens 140, that is, a separation distance corresponding to a focal length given when the lens 140 is designed, and the image sensor 111 is a substrate ( The image barrel 110 and the lens 140 may be vertically transferred from the upper and lower portions of the housing 120 by mounting the lens barrel 130 on which the lens 140 is mounted since the position thereof may be fixed. In order to have a focal length that follows the design criteria of the lens 140.

Meanwhile, as shown in FIG. 5, when mounting the image sensor 111 of the substrate 110 using the wire bonding method, the inner wall surface of the housing 120 coupled to the upper surface of the substrate 110 becomes thinner toward the bottom. It is composed of an inclined surface (122).

This is to secure the bonding path of the wire W when bonding is performed using the wire W between the pad 110a formed on the substrate 110 and the pad 111a formed on the upper surface of the image sensor 111.

That is, when the inner wall surface of the housing 120 is formed vertically, when the wire bonding of the substrate 110 and the image sensor 111 is performed, interference in the bonding path between the wires W may inevitably occur. Will be processed.

Preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and various substitutions, modifications, and changes within the scope without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains. It will be possible, but such substitutions, changes and the like should be regarded as belonging to the following claims.

As described above, the camera module of the present invention prevents the inflow of foreign matters generated at the screw coupling portion during assembly and focusing of the housing and the lens barrel, and at the same time, the foreign matter in the assembled camera module is adsorbed to the adhesive coated on the inner circumferential surface. By doing so, there is an advantage that the black spot or color spot phenomenon due to foreign matter can be fundamentally prevented.

Claims (14)

A lens barrel having a lens insertion hole in which at least one lens is mounted at a central portion thereof, and having a circular groove having a female screw portion formed on an inner circumferential surface of the lens insertion hole; A lens fixing cap covered on an upper portion of the lens barrel and supporting an upper surface of the lens; A housing which is inserted into a circular groove of the lens barrel and has a barrel coupling portion upwardly formed with a male screw portion to enable screwing with the female screw portion; And And a substrate, which is tightly coupled to a lower portion of the housing and has an image sensor mounted on an upper surface thereof to form light passing through the lens. Camera module coated with a pressure-sensitive adhesive is adsorbed on the inner wall surface of the housing and the lens barrel. The method of claim 1, The housing and the lens barrel are screwed on the outer peripheral surface of the housing by a male screw portion formed on the outer circumferential surface of the barrel coupling portion and a female screw portion formed on the circular groove, and the focus adjustment is performed by rotating the lens barrel about the screw coupling portion. Camera module, characterized in that. The method according to claim 1 or 2, The male screw portion and the female screw portion have a minimum pitch of 3 pitches without exceeding the design height of the camera module, and each screw thread has a size of 0.3 μm. The method of claim 1, The lens barrel is a camera module, characterized in that the lower surface of the lens is seated and supported on the upper surface of the rib formed inwardly into the lens insertion port. The method of claim 4, wherein The lens insertion port is a camera module, characterized in that consisting of a circular shape or a square groove. The method of claim 1, The circular groove is a camera module, characterized in that formed in a depth corresponding to the extension length of the barrel engaging portion or a depth within the transport range of the upper end of the barrel engaging portion. The method of claim 1, The lens module, characterized in that the IR filter layer is deposited or coated on any one of the upper surface and the lower surface. The method of claim 1, The lens module is a camera module, characterized in that the wafer lens is provided with an IR filter layer on any one of the upper surface and the lower surface. The method of claim 8, The wafer lens is manufactured by injection molding through a replica method in a wafer level state, and the camera module, characterized in that cut to a rectangular unit wafer lens. The method of claim 1, The image sensor mounted on the substrate, the camera module, characterized in that electrically connected to the substrate by wire bonding (COB) using a wire. The method of claim 1, The housing is a camera module, characterized in that consisting of an inclined surface of the inner wall surface is thinner toward the bottom in order to secure the wire bonding position of the image sensor mounted on the substrate. The method of claim 1, The lens fixing cap is a camera module, characterized in that formed of a black-based material so that the external light does not penetrate through the portion except the center portion. delete A lens barrel having a lens insertion hole in which at least one lens is mounted at a central portion thereof, and having a circular groove having a female screw portion formed on an inner circumferential surface of the lens insertion hole; A lens fixing cap covered on an upper portion of the lens barrel and supporting an upper surface of the lens; A housing which is inserted into a circular groove of the lens barrel and has a barrel coupling portion upwardly formed with a male screw portion to enable screwing with the female screw portion; And And a substrate, which is tightly coupled to a lower portion of the housing and has an image sensor mounted on an upper surface thereof by imaging light passing through the lens by a flip chip (COF) method. Camera module coated with a pressure-sensitive adhesive is adsorbed on the inner wall surface of the housing and the lens barrel.

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