Camera module and method for making the same

A camera module includes a lens barrel, a lens, a sensing element, and an electromagnetic shield. The lens barrel defines a receiving space. The lens is mounted in the receiving space. The sensing element is covered by the lens barrel, is disposed below the lens, and is spaced apart from the lens. The sensing element includes a top face, a bottom face, a side face extending between the top and bottom faces, a plurality of first conductors mounted on the bottom face, at least one second conductor mounted on one of the top, bottom, and side faces, and a grounding element having one end connected to one of the first conductors and the other end connected to the second conductor. The electromagnetic shield is coupled to the lens barrel and includes a grounding portion electrically connected to the second conductor.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese Application No. 200810026312.4, filed on Feb. 3, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a camera module, more particularly to a camera module which has protection against electromagnetic interference. The invention also relates to a method for making the camera module.

2. Description of the Related Art

Referring toFIGS. 1 and 2, a conventional camera module1includes a lens barrel11defining a receiving space111, a lens12received in the receiving space111, a sensing element13covered by the lens barrel11and disposed below the lens12, and an electromagnetic shield14. The sensing element13includes a plurality of conductors131mounted on a bottom face thereof. The electromagnetic shield14is formed with two opposite engaging holes141and has two opposite grounding portions142below the engaging holes141. The lens barrel11has two opposite engaging blocks112. The electromagnetic shield14is engaged to the lens barrel11mechanically or manually by anchoring the engaging blocks112of the lens barrel11in the engaging holes141of the electromagnetic shield14correspondingly so as to provide protection against electromagnetic interference.

A circuit board15is provided with a plurality of first conductive pads151for connecting to the grounding portions142of the electromagnetic shield14correspondingly, and a plurality of second conductive pads152for connecting to the conductors131of the sensing element13correspondingly. When the camera module1is assembled to the circuit board15by surface mount technology, it is required to have precise sizes and locations for the first and second conductive pads151,152, the grounding portions142of the electromagnetic shield14, and the conductors131of the sensing element13so as to connect the grounding portions142and the conductors131to the first and second conductive pads151,152correspondingly and precisely. However, there are tolerances for the grounding portions142and the conductors131. Therefore, it is relatively difficult to connect the grounding portions142of the electromagnetic shield14and the conductors131of the sensing element13to the first and second conductive pads151,152of the circuit board15correspondingly and precisely during assembly of the lens barrel1to the circuit board15. The yield of the conventional camera module1is not satisfactory, and the cost for producing the conventional camera module1is relatively high.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a camera module the yield of which is increased and the production cost thereof is lowered. Another object of the present invention is to provide a method for making the camera module.

In the first aspect of this invention, a camera module includes a lens barrel, a lens, a sensing element, and an electromagnetic shield. The lens barrel defines a receiving space, and has a top opening communicated with the receiving space. The lens is mounted in the receiving space, and is aligned with the top opening. The sensing element is covered by the lens barrel, is disposed below the lens, and is spaced apart from the lens. The sensing element includes a top face, a bottom face, a side face extending between the top and bottom faces, a plurality of first conductors mounted on the bottom face, at least one second conductor mounted on one of the top, bottom, and side faces, and a grounding element having one end connected to one of the first conductors and the other end connected to the second conductor. The electromagnetic shield is coupled to the lens barrel, and includes a grounding portion electrically connected to the second conductor.

In the second aspect of this invention, a method for making a camera module includes the steps of:

providing a lens unit, an electromagnetic shield, and a sensing element, the lens unit including a lens barrel and a lens mounted in the lens barrel, the electromagnetic shield including a grounding portion, the sensing element including a top face, a bottom face, a side face extending between the top and bottom faces, a plurality of first conductors mounted on the bottom face, at least one second conductor mounted on one of the top, bottom, and side faces, and a grounding element having one end connected to one of the first conductors and the other end connected to the second conductor;

coupling the electromagnetic shield to the lens barrel and the sensing element; and

connecting the grounding portion of the electromagnetic shield to the second conductor of the sensing element.

In the third aspect of this invention, an electronic device includes a main body and a camera module. The main body is formed with a receiving space and an opening communicated with the receiving space. The camera module is received in the receiving space, and includes a lens barrel, a lens, a sensing element, and an electromagnetic shield. The lens barrel defines a receiving space, and has a top opening communicated with the receiving space of the lens barrel and aligned with the opening of the main body. The lens is mounted in the receiving space of the lens barrel, and is aligned with the top opening. The sensing element is covered by the lens barrel, is disposed below the lens, and is spaced apart from the lens. The sensing element includes a top face, a bottom face, a side face extending between the top and bottom faces, a plurality of first conductors mounted on the bottom face, at least one second conductor mounted on one of the top, bottom, and side faces, and a grounding element having one end connected to one of the first conductors and the other end connected to the second conductor. The electromagnetic shield is coupled to the lens barrel, and includes a grounding portion electrically connected to the second conductor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 3 to 5, the first preferred embodiment of a camera module300according to this invention is installed in an electronic device20, which is illustrated as a cellular phone. The camera module300can be installed in a personal digital assistant (PDA) or other portable electronic devices. The electronic device20includes a main body200and the camera module300. The main body200is formed with a receiving space21and an opening22communicated with the receiving space21. The camera module300is received in the receiving space21, and includes a lens unit3, a sensing element4, a dustproof element5, and an electromagnetic shield35.

The lens unit3includes a lens barrel31, a lens32, a filter33, and a spacing ring34. The lens barrel31is made of a plastic material, defines a receiving space311, and has a top opening312communicated with the receiving space311and aligned with the opening22of the main body200. The lens32, the filter33, the spacing ring34, and the dustproof element5are mounted in the receiving space311of the lens barrel31. The lens32is aligned with the top opening312, and is mounted on the filter33. The filter33used in the preferred embodiment is an infrared (IR) filter. The spacing ring34is mounted between the filter33and the dustproof element5. The spacing ring34has a certain thickness, and confines a through hole341aligned with the opening22of the main body200and the top opening312of the lens barrel31.

The sensing element4is covered by the lens barrel31, is disposed below the dustproof element5, and is spaced apart from the lens32. The sensing element includes a top face42, a bottom face41, two side faces43each extending between the top and bottom faces42,41, a plurality of first conductors44mounted on the bottom face41, two second conductors45mounted opposite to each other on the top face42, and two grounding elements46. Each of the second conductors45is formed as a conductive metal pad. Each of the grounding elements46is made of a metal material, and has one end461connected to one of the first conductors44and the other end462connected to a corresponding one of the second conductors45.

The electromagnetic shield35is made of a metal material and provides protection against electromagnetic interference. In this preferred embodiment, the electromagnetic shield35is embedded in the lens barrel31by insert molding so as to be coupled to the lens barrel31. The electromagnetic shield35includes a shield body351and two grounding portions352extending from the shield body351and electrically connected to the second conductors45correspondingly so that each of the grounding portions352of the electromagnetic shield35is connected electrically to a corresponding one of the first conductors44via a corresponding one of the second conductors45and a corresponding one of the grounding elements46. In this preferred embodiment, each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the second conductors45of the sensing element4.

Since the distance between the sensing element4and the lens32is maintained by using the spacing ring34, the effect of assembly tolerance can be minimized and the need to adjust the focal distance can be avoided. It should be noted that the thickness of the spacing ring34is chosen according to requirements, i.e., the desired focal distance between the lens32and the sensing element4. Furthermore, since the electromagnetic shield35is embedded in the lens barrel31by insert molding, and since each of the grounding portions352of the electromagnetic shield35is connected electrically to a corresponding one of the first conductors44via a corresponding one of the second conductors45and a corresponding one of the grounding elements46, the grounding portions352of the electromagnetic shield35can be connected electrically to the circuit board7in an easy and precise manner by connecting the first conductors44to the conductive pads71of the circuit board7correspondingly. Therefore, the yield of the camera module300is increased as compared to the aforesaid prior art.

Referring toFIGS. 6 to 9, a method for making the first preferred embodiment of the camera module300includes the steps of:

A) Providing a Lens Unit3, the Electromagnetic Shield35, and the Sensing Element4:

The lens unit3includes the lens barrel31, and the lens32, the filter33, and the spacing ring34mounted in the lens barrel31. The electromagnetic shield35includes two opposite grounding portions352. A plurality of the sensing elements4are provided on a wafer40, and a plurality of the dustproof elements5are respectively mounted on the sensing elements4in an automated manner. The sensing element4includes the top face42, the bottom face41, the side faces43extending between the top and bottom faces42,41, the first conductors44mounted on the bottom face41, the second conductors45mounted on the top face42, and the grounding elements46each having one end461connected to one of the first conductors44and the other end462connected to a corresponding one of the second conductors45.

B) Coupling the Electromagnetic Shield35to the Lens Barrel31:

The electromagnetic shield35is embedded in the lens barrel31by insert molding so as to be coupled to the lens barrel31.

C) Coupling the Electromagnetic Shield35to the Sensing Element4:

A plurality of the lens units3are mounted on the sensing elements4of the wafer4correspondingly, and the grounding portions352of the electromagnetic shields35are connected to the second conductors45of the sensing elements4correspondingly, for example, using a glue, so as to assemble the lens units3to the sensing elements4correspondingly. The wafer4is baked so that the lens units3are firmly connected to the sensing elements4. A plurality of the camera modules300are obtained by cutting the wafer4.

Referring toFIG. 10, the second preferred embodiment of a camera module300according to this invention is shown to be similar to the first preferred embodiment except that the second conductors45are formed as conductive pads mounted on the bottom face41of the sensing element4and extending to the side faces43of the sensing element4and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the side faces43of the sensing element4and a corresponding one of the conductive pads.

Referring toFIG. 11, the third preferred embodiment of a camera module300according to this invention is shown to be similar to the first preferred embodiment except that each of the second conductors45is formed as a conductive pad mounted on a corresponding one of the side faces43of the sensing element4and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the conductive pads.

Referring toFIGS. 12 to 14, the fourth preferred embodiment of a camera module300according to this invention is shown to be similar to the first preferred embodiment except that the electromagnetic shield35is sleeved on the lens barrel31and that the camera module300further includes a housing36sleeved around the lens barrel31, the electromagnetic shield35, and the sensing element4.

A method for masking the fourth preferred embodiment is similar to that for the first preferred embodiment except that the electromagnetic shield35is coupled to the sensing element4by sleeving the electromagnetic shield35on the sensing element4and that the method for making the fourth preferred embodiment further includes a step of sleeving the housing36around the lens barrel31, the electromagnetic shield35, and the sensing element4by insert molding.

Referring toFIG. 15, the fifth preferred embodiment of a camera module300according to this invention is shown to be similar to the fourth preferred embodiment except that the second conductors45are formed as conductive pads mounted on the bottom face41of the sensing element4and extending to the side faces43of the sensing element4and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the side faces43of the sensing element4and a corresponding one of the conductive pads.

Referring toFIG. 16, the sixth preferred embodiment of a camera module300according to this invention is shown to be similar to the fourth preferred embodiment except that each of the second conductors45is formed as a conductive pad mounted on a corresponding one of the side faces43of the sensing element4and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the conductive pads.

Referring toFIGS. 17 and 18, the seventh preferred embodiment of a camera module300according to this invention is similar to the first preferred embodiment except that two lenses32are mounted in the lens barrel31and that the electromagnetic shield35is sleeved around the lens barrel31and the sensing element4. Furthermore, in this preferred embodiment, the second conductor45is formed as a conductive pad mounted on the bottom face41of the sensing element4. The grounding portion352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against the conductive pad. A filter and a spacing ring (not shown in the figures) can be optionally received in the lens barrel31.

Referring toFIGS. 18 to 20, a method for making the seventh preferred embodiment includes the steps of:

A′) Providing the Lens Unit3, the Electromagnetic Shield35, and the Sensing Element4:

The lens unit3includes the lens barrel31, and two lenses32mounted in the lens barrel31. The electromagnetic shield35includes two opposite grounding portions352. A plurality of the sensing elements4are provided on a wafer (not shown in the figures), and a plurality of the dustproof elements5are respectively mounted on the sensing elements4(best shown inFIG. 18). The sensing element4includes the top face42, the bottom face41, the side faces43extending between the top and bottom faces42,41, the first conductors44mounted on the bottom face41, the second conductors45mounted on the bottom face41, and the grounding elements46each having one end461connected to one of the first conductors44and the other end462connected to a corresponding one of the second conductors45.

B′) Assembling the Lens Unit3to the Sensing Element4:

A plurality of the lens units3are assembled to the sensing elements4of the wafer correspondingly, for example, using a glue. The wafer is baked so that the lens units3are firmly connected to the sensing elements4. The wafer is cut to obtain a plurality of intermediate products.

C′) Sleeving the Electromagnetic Shield35Around the Lens Barrel31and the Sensing Element4:

The electromagnetic shield35is sleeved around the lens barrel31and the sensing element4of each of the intermediate products so as to obtain the camera module300.

Referring toFIG. 21, the eighth preferred embodiment of a camera module300according to this invention is shown to be similar to the seventh preferred embodiment except that the second conductors45are formed as conductive pads mounted on the top face42of the sensing element4and extending to the side faces43of the sensing element4, and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the side faces43of the sensing element4and a corresponding one of the conductive pads.

Referring toFIG. 22, the ninth preferred embodiment of a camera module300according to this invention is shown to be similar to the seventh preferred embodiment except that each of the second conductors45is formed as a conductive pad mounted on a corresponding one of the side faces43of the sensing element4and that each of the grounding portions352of the electromagnetic shield35is formed as a connecting leg provided at a bottom part of the lens barrel31and abutting against a corresponding one of the conductive pads.

Referring toFIG. 23, the tenth preferred embodiment of a camera module300according to this invention is shown to be similar to the first preferred embodiment except that the lens barrel31includes an outer peripheral face315and a bottom face316laterally extending from the outer peripheral face315and that the electromagnetic shield35is a metal layer plated on the outer peripheral face315and the bottom face316of the lens barrel31so that the electromagnetic shield35is coupled to the lens barrel31.