Method for making camera modules and camera module made thereby

A method for making lens modules includes the steps of: a) providing a wafer including an array of sensor chips; b) mounting a plurality of lens assemblies on the sensor chips, respectively, thereby defining a plurality of intersecting spacing grooves among the lens assemblies; c) forming substrate layer by filling in the spacing grooves with a resin material; and d) cutting the wafer and the substrate layer along intersecting cutting lines each extending along one of the spacing grooves and each intervening the lens assemblies, the substrate layer being divided into a plurality of barrels respectively surrounding the lens assemblies. A lens module made by the method is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese Application No. 200810029455.0, filed on Jul. 10, 2008.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a method for making lens modules, more particularly to a method for making lens modules in a manner of wafer level packaging. The invention also relates to a lens module made by the method.

2. Description of the Related Art

Referring toFIG. 1, Taiwanese Utility Model No. M314431 discloses a lens module1including a substrate11, a sensor chip assembly12, and a lens assembly13. The sensor chip assembly12is mounted on the substrate11, and is electrically connected to the substrate11via solder balls121. The lens assembly13covers the sensor chip assembly12, and includes a barrel131and a lens132.

Conventionally, the aforesaid lens module1is made individually. Therefore, the productivity is low and the production cost is relatively high.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a method for making lens modules in a manner of wafer level packaging so that the productivity can be increased and that the production cost and the size of the lens module can be reduced.

Another object of the present invention is to provide a lens module made by the method of this invention.

In the first aspect of this invention, a method for making lens modules includes the steps of: a) providing a wafer including an array of sensor chips; b) mounting a plurality of lens assemblies on the sensor chips, respectively, thereby defining a plurality of intersecting spacing grooves among the lens assemblies; c) forming a substrate layer by filling in the spacing grooves with a resin material; and d) cutting the wafer and the substrate layer along intersecting cutting lines each extending along one of the spacing grooves and each intervening the lens assemblies, the substrate layer being divided into a plurality of barrels respectively surrounding the lens assemblies.

In the second aspect of this invention, a lens module includes a sensor chip, a lens assembly, and a barrel. The sensor chip has a first surface and a second surface opposite to the first surface. The lens assembly is mounted on the first surface of the sensor chip and has a cross-section smaller than that of the sensor chip so that the first surface of the sensor chip has an excess surface portion around the lens assembly. The barrel is mounted on the excess surface portion of the first surface of the sensor chip and surrounds the lens assembly. The barrel has an outer lateral surface flush with a peripheral end of the sensor chip.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 2A to 2G, the first preferred embodiment of a method for making lens modules according to this invention includes the steps of:

A) providing a wafer:

Referring toFIG. 2A, a wafer220is provided, which includes an array of sensor chips22, and has a first surface221and a second surface222opposite to the first surface221.

B) mounting a surrounding wall:

Referring toFIG. 2B, a surrounding wall3is mounted on the first surface221of the wafer220. The surrounding wall3extends along the periphery of the wafer220. In the preferred embodiment, the surrounding wall3is connected to the first surface221of the wafer220in a gluing manner.

C) mounting a plurality of lens assemblies:

Referring toFIG. 2C, a plurality of lens assemblies24are simultaneously mounted on the sensor chips22, respectively, using an automatic equipment (not shown), thereby defining a plurality of intersecting spacing grooves4among the lens assemblies24. The lens assemblies24and the spacing grooves4are surrounded by the surrounding wall3. The lens assemblies24are fixed on the first surface221of the wafer220in a gluing manner. Each of the lens assemblies24has a light-transmissive portion241on top thereof.

D) filling a resin material:

Referring toFIG. 2D, a resin material is filled into the surrounding wall3and the spacing grooves4to form a substrate layer210. In the preferred embodiment, the substrate layer210is substantially flush with the lens assemblies24so as to prevent the light-transmissive portion241of each of the lens assemblies24from being covered with the resin material. The resin material is preferably filled into the surrounding wall3and the spacing grooves4at a plurality of filling spots so as to shorten the filling period.

E) mounting a plurality of conductive blocks:

Referring toFIG. 2E, a plurality of conductive blocks23are mounted on bonding pads (not shown) on the second surface222of the wafer220using a surface mounting technology after the resin material is solidified. In the preferred embodiment, the conductive blocks23are solder balls. Alternatively, the conductive blocks23can be conductive bumps.

F) cutting the wafer and the substrate layer:

Referring toFIG. 2F, the wafer220and the substrate layer210are cut along intersecting cutting lines6each extending along one of the spacing grooves4and each intervening the lens assemblies24. The substrate layer210is divided into a plurality of barrels21(best shown inFIG. 2G) respectively surrounding the lens assemblies24.

Referring toFIG. 2G, a plurality of lens modules2are made simultaneously by the aforesaid method. Each of the lens modules2includes the sensor chip22, the lens assembly24, the barrel21, and a plurality of the conductive blocks23.

The sensor chip22has a first surface221′ and a second surface222′ opposite to the first surface221′. The second surface222′ is provided with a plurality of bonding pads (not shown) thereon.

The lens assembly24is mounted on the first surface221′ of the sensor chip22and has the light-transmissive portion241on top thereof. The lens assembly24has a cross-section smaller than that of the sensor chip22so that the first surface221′ of the sensor chip22has an excess surface portion around the lens assembly24.

The barrel21is mounted on the excess surface portion of the first surface221′ of the sensor chip22and surrounds the lens assembly24. The barrel21has an outer lateral surface flush with a peripheral end of the sensor chip22. The barrel21is opaque. In the preferred embodiment, the barrel21is made of black epoxy resin.

The conductive blocks23are mounted on the second surface222′ of the sensor chip22. In the preferred embodiment, the conductive blocks23are solder balls. Alternatively, the conductive blocks23can be conductive bumps.

Referring toFIGS. 3A to 3H, the second preferred embodiment of a method for making lens modules according to this invention is substantially identical to the first preferred embodiment except for the following.

Referring toFIG. 3D, after the lens assemblies24are simultaneously mounted on the sensor chips22, respectively, a cover layer250is mounted on the lens assemblies24. The cover layer250is in the form of a thin circular plate having a diameter identical to an inner diameter of the surrounding wall3. The cover layer250includes a plurality of light-transmissive holes252corresponding to the light-transmissive portions241of the lens assemblies24, and a plurality of injecting holes251spaced apart from each other and communicated with the spacing grooves4.

Referring toFIG. 3E, after the cover layer250is mounted on the lens assemblies24, the resin material is filled into the surrounding wall3and the spacing grooves4via the injecting holes251of the cover layer250to form the substrate layer210. In the preferred embodiment, the substrate layer210has a thickness so that the top surface of the substrate layer210is substantially flush with the bottom surface of the cover layer250.

Referring toFIG. 3H, each of the lens modules2made by the second preferred embodiment is substantially similar to each of the lens modules2made by the first preferred embodiment except that each of the lens modules2made by the second preferred embodiment includes a cover25. The cover25is mounted on the barrel21and the lens assembly24, and has a light-transmissive through hole corresponding to the light-transmissive portion241of the lens assembly24. The cover25has an outer lateral surrounding surface substantially flush with the outer lateral surface of the barrel21and with the peripheral end of the sensor chip22. The barrel21is mounted between the cover25and the sensor chip22.

Referring toFIGS. 4A to 4I, the third preferred embodiment of a method for making lens modules according to this invention includes the steps of:

I) providing a wafer:

Referring toFIG. 4A, a wafer220is provided, which includes an array of sensor chips22, and has a first surface221and a second surface222opposite to the first surface221.

II) mounting a plurality of lens assemblies:

Referring toFIG. 4B, a plurality of lens assemblies24are simultaneously mounted on the sensor chips22, respectively, using an automatic equipment (not shown), thereby defining a plurality of intersecting spacing grooves4between the lens assemblies24. The lens assemblies24are fixed on the first surface221of the wafer220in a gluing manner. Each of the lens assemblies24has a light-transmissive portion241on top thereof.

III) mounting the wafer in a mold:

Referring toFIGS. 4C and 4D, a mold5is provided, which includes an upper mold part53, a lower mold part51cooperating with the upper mold part53to define a mold cavity55, and a plurality of ejecting pins220opposite to the upper mold part53and inserted into the lower mold part51. The wafer220is mounted in the lower mold part51. The upper mold part53is then mounted on the lower mold part51so as to close the mold5and to receive the wafer220with the lens assemblies24in the mold cavity55. The upper mold part53includes an upper mold component531and a lower mold component532cooperating with the upper mold component531to define a runner56. The lower mold component532is provided with a plurality of openings533communicating with the spacing grooves4.

IV) filling a resin material:

Referring toFIG. 4E, a resin material is filled into the lower mold part51and the spacing grooves4through the runner56, and the openings533of the lower mold component532of the upper mold part53so as to form a substrate layer210by insert molding. In the preferred embodiment, the resin material is filled into the lower mold part51and the spacing grooves4through a plurality of the openings533so as to shorten the filling period.

V) taking the wafer out of the mold:

Referring toFIGS. 4E and 4F, after the resin material is solidified, the upper mold part53is moved away from the lower mold part51, and the ejecting pins220are moved upward so as to eject and take the wafer220out of the lower mold part51.

VI) mounting a plurality of conductive blocks:

Referring toFIG. 4G, a plurality of conductive blocks23are mounted on bonding pads (not shown) on the second surface222of the wafer220using a surface mounting technology. In the preferred embodiment, the conductive blocks23are solder balls. Alternatively, the conductive blocks23can be conductive bumps.

VII) cutting the wafer and the substrate layer:

Referring toFIG. 4H, the wafer220and the substrate layer210are cut along intersecting cutting lines6each extending along one of the spacing grooves4and each intervening the lens assemblies24. The substrate layer210is divided into a plurality of barrels21(best shown inFIG. 4I) respectively surrounding the lens assemblies24.

Referring toFIG. 4I, a plurality of lens modules2are made simultaneously by the aforesaid method. Each of the lens modules2made by the third preferred embodiment of the method of this invention is identical to that made by the first preferred embodiment of the method of this invention.

Referring toFIGS. 5A to 5J, the fourth preferred embodiment of a method for making lens modules according to this invention is substantially identical to the third preferred embodiment except for the following.

Referring toFIG. 5D, after the wafer220is mounted in the lower mold part51, a cover layer250is mounted on the lens assemblies24. The cover layer250is in the form of a thin circular plate having a diameter identical to an inner diameter of the lower mold part51. The cover layer250includes a plurality of light-transmissive holes252corresponding to the light-transmissive portions241of the lens assemblies24, and a plurality of injecting holes251spaced apart from each other and communicated with the spacing grooves4.

Referring toFIGS. 5E and 5F, after the mold5is closed, the resin material is filled into the lower mold part51and the spacing grooves4through the runner56, the openings533of the lower mold component532of the upper mold part53, and the injecting holes251of the cover layer250so as to form a substrate layer210by insert molding.

Referring toFIG. 5J, a plurality of lens modules2are made simultaneously by the aforesaid method. Each of the lens modules2made by the fourth preferred embodiment of the method of this invention is identical to that made by the second preferred embodiment of the method of this invention.

In view of the aforesaid, a plurality of lens modules2each having a miniaturized size can be made by the method of this invention. Therefore, the yield is increased and the production cost is reduced.