TWI396923B - Miniature camera module and method for making same - Google Patents

Description

Micro camera module and manufacturing method thereof

The present invention relates to the field of optical imaging, and in particular, to a miniature camera module and a method of fabricating the same.

In recent years, electronic products with camera functions, such as mobile phones, have become more and more popular among consumers. However, as mobile phones are becoming more and more thin and light, the conventional camera modules are difficult to integrate into mobile phones due to their large size, so that the mobile phones have both camera functions.

See "Novel Wafer Level Package Technology Studies for Image Sensor Devices" by Gautham Viswanadam et al., at the 2005 Electronics Packaging Technology Conference, which discloses a micro camera module in a wafer level package that includes a semiconductor image sensing. A semiconductor (Semiconductor Imaging Chip) and a lens module assembled with a semiconductor image sensing chip to form a single module. This kind of miniature camera module is expected to be applied to the next generation of thin and light mobile phones due to its small size and low cost.

Since the miniature camera module has a smaller size than the conventional camera module, the entire process will be different from the conventional camera module in order to meet the size requirements and mass production requirements; and the lens module The optical performance requirements of the group will also tend to be strict to achieve better image quality.

In view of this, it is necessary to provide a miniature camera module with better imaging quality and a method of manufacturing the same.

A miniature camera module includes: an image sensing unit including a photosensitive area; and a lens unit coupled to one side of the image sensing unit adjacent to the photosensitive area, the lens unit including a glass lining a bottom, a transparent nucleation layer on the glass substrate and a lens on the transparent nucleation layer, the lens having a main optical axis disposed on a main optical axis of the lens and associated with the lens Unit interval setting.

And a method of fabricating a miniature camera module, comprising the steps of: providing a semiconductor wafer (wafer) formed with a plurality of photosensitive regions; providing a glass wafer having a transparent nucleation layer deposited thereon and a plurality of vias An embossing process is formed on the transparent nucleation layer, the plurality of lenses respectively have a main optical axis; and the glass wafer is bonded to the side of the semiconductor wafer on which one of the plurality of photosensitive regions is formed, the plural a photosensitive area spaced from the glass wafer and the plurality of photosensitive areas are located on a main optical axis of the lens corresponding thereto, thereby forming a wafer level micro camera module array; and cutting the micro camera module array to obtain A plurality of individual miniature camera modules separated from each other.

The miniature camera module and the method of fabricating the same, which control the surface tension of the lens of the lens unit during formation and enhance the adhesion between the lens and the glass substrate by providing a transparent nucleation layer. On the one hand, the control of the surface tension can inhibit the lens from excessively shrinking due to excessive surface tension during its formation to prevent its optical performance from deteriorating; on the other hand, the enhancement of the adhesion force can tightly bond the lens to the glass substrate without falling off.

10, 30‧‧‧ miniature camera module

12‧‧‧Image sensing unit

121‧‧‧Semiconductor substrate

123‧‧‧Photosensitive area

13‧‧‧ spacer

14‧‧‧Transparent cover

15‧‧‧Infrared cut filter

16‧‧‧Interval unit

17‧‧‧ lens unit

171‧‧‧ glass substrate

173‧‧‧Transparent nucleation layer

175‧‧‧ lens

221‧‧‧Semiconductor wafer

23‧‧‧ spacer wafer

231‧‧‧through hole

24‧‧‧ Transparent Cover Wafer

25‧‧‧Infrared cut filter

26‧‧‧Interval unit wafer

261‧‧‧through hole

271‧‧‧glass wafer

273‧‧‧Transparent nucleation layer

36‧‧‧Interval unit

37‧‧‧ lens unit

371‧‧‧ glass substrate

373‧‧‧Transparent nucleation layer

375‧‧‧ lens

46‧‧‧Interval unit wafer

471‧‧‧glass wafer

473‧‧‧Transparent nucleation layer

1 is a schematic cross-sectional view of a miniature camera module according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a method for fabricating the miniature camera module of FIG. 1 according to an embodiment of the present invention; FIG. A partial schematic of the state.

3 is a top plan view of an array of wafer level miniature camera modules fabricated in accordance with an embodiment of the present invention.

4 is a schematic cross-sectional view showing another miniature camera module according to a second embodiment of the present invention.

FIG. 5 is a partial schematic view showing a process state of a method for manufacturing the miniature camera module shown in FIG. 4 according to an embodiment of the present invention.

The technical solution will be further described in detail below with reference to the accompanying drawings and embodiments.

First embodiment

Referring to FIG. 1 , a miniature camera module 10 according to a first embodiment of the present invention includes an image sensing unit 12 , a spacer layer 13 , a transparent cover 14 , and an infrared cut filter (Infra-red Cut Filter). A layer 15, a spacer unit 16, and a lens unit 17.

The image sensing unit 12 is a solid-state image sensing device such as a charge coupled sensing device (CCD) or a complementary metal oxide semiconductor (CMOS) device. The image sensing unit may include a semiconductor substrate 121 and a photosensitive region 123 formed on a side of the semiconductor substrate 121 via a semiconductor process; the semiconductor substrate 121 may be a germanium substrate.

The spacer layer 13 is bonded to one side of the image sensing unit 12 on which the photosensitive region 123 is formed, which is an annular structure, such as a square ring structure. The square annular structure can have a square outline and a circular through hole. The spacer layer 13 may be bonded to the image sensing unit 12 via an adhesive (not shown) such as an ultraviolet curable resin or a thermosetting resin.

The transparent cover 14 is joined to one side of the spacer layer 13 away from the image sensing unit 12, and is spaced apart from the photosensitive area 123 by a predetermined distance via the spacer layer 13. The transparent cover 14 can be bonded to the spacer layer 13 via an adhesive (not shown) such as an ultraviolet curable resin or a thermosetting resin. Together, the photosensitive area 123 is sealed. The transparent cover 14 may be made of a transparent material such as glass.

The infrared cut filter layer 15 is disposed on a side of the transparent cover 14 away from the photosensitive area 123 for filtering infrared light. It can be understood that, depending on the application of the miniature camera module 10, for example, for infrared imaging, the infrared cut filter layer 15 needs to be changed to an infrared-infrared filter (Infra-red Pass Filter) filter layer accordingly.

The spacer unit 16 is bonded between the infrared cut filter layer 15 and the lens unit 17 to form a predetermined interval between the infrared cut filter layer 15 and the lens unit 17. The spacer unit 16 is an annular structure, and the material thereof is preferably a black light blocking material.

The lens unit 17 is coupled to one side of the spacing unit 16 away from the infrared cut filter layer 15 for optical imaging of the object; the optical imaging can be sensed by the photosensitive area 123 of the image sensing unit 12 Generate corresponding electronic image signals. The lens unit 17 includes a glass substrate 171, a transparent nucleation layer 173 on the glass substrate 171, and a lens 175 on the transparent nucleation layer 173. The lens 175 has a main optical axis OO'. The transparent nucleation layer 173 is used to control the surface tension of the lens 175 during its formation and the adhesion between the lens 175 and the glass substrate 171; thus, on the one hand, the lens 175 can be inhibited from being excessively excessive due to excessive surface tension during its formation. Shrinkage to prevent its optical performance from degrading; on the other hand, the lens 175 can be tightly bonded to the glass substrate 171 without falling off. The transparent nucleation layer 173 is made of a material different from the glass substrate 171 and the lens 175, and may be made of an inorganic transparent material such as cerium oxide (SiOx, x is 1 to 2) or titanium dioxide (TiO2). The lens 175 can be a plastic lens such as a spherical, aspherical or folded hybrid plastic lens. The lens 175 can be formed by an imprint process such as UV Embossing, Hot Embossing, or Nitrogen Embossing.

It should be noted that the micro camera module 10 of the first embodiment of the present invention may not be provided with the transparent cover 14, the infrared cut filter layer 15 and the spacer unit 16, but The lens unit 17 is directly bonded to one side of the image sensing unit 12 adjacent to the photosensitive region 123 via the spacer layer 13 and an adhesive (not shown), and the photosensitive layer 123 is disposed via the spacer layer 13 Interval by a preset distance. In addition, it can be understood that the size of the preset distance can be adjusted by setting the thickness of the spacer layer 13. Further, the lens unit 17 is not limited to providing a transparent nucleation layer and a lens on only one side of the glass substrate 171, and a transparent nucleation layer and a lens may be provided on both surfaces of the glass substrate 171.

Referring to Figures 2 and 3, a method of fabricating the miniature camera module 10 will be specifically described below, which may generally include the following steps:

Step (a): providing a semiconductor wafer (Wafer) 221 on which a plurality of photosensitive regions 123 are formed via a semiconductor process; in this embodiment, the semiconductor wafer 221 is a germanium wafer.

Step (b): providing a spacer wafer 23, forming a plurality of through holes 231, such as circular through holes, on the spacer wafer 23 by etching, or laser drilling, or ultrasonic drilling.

Step (c): providing a transparent cover wafer 24, and forming an infrared cut filter layer 25 on one surface of the transparent cover wafer 24 by sputtering or evaporation; in this embodiment, The transparent cover wafer 24 is a glass wafer.

Step (d): providing a black spacer cell wafer 26, forming a plurality of via holes 261, such as circular via holes, on the spacer cell wafer 26 by etching, or laser drilling, or ultrasonic drilling.

Step (e): providing a glass wafer 271, depositing a transparent nucleation layer 273 on the glass wafer 271; the transparent nucleation layer 273 may be deposited on the glass wafer 271 by evaporation or sputtering. The surface tension and the adhesion of the lens 175 to the glass wafer 271 are controlled during the formation of the subsequent lens 175. The material of the transparent nucleation layer 273 is different from the glass wafer 271, which may be an inorganic transparent material such as cerium oxide or titanium dioxide. Then, a plurality of lenses 175 are formed on the transparent nucleation layer 273 via an imprint process.

Specifically, the imprint process may be (i) ultraviolet embossing: embossing a UV curable resin layer formed on the transparent nucleation layer 273 by using a molding surface of a stamper to form a plurality of lens preforms, And curing the lens preform by ultraviolet light to obtain a plurality of the lenses 175; (ii) hot stamping: stamping a thermoplastic resin layer formed on the transparent nucleation layer 273 by using a molding surface of a stamper The embossing process controls the embossing temperature and the pressure applied to the back surface of the stamper relative to the molding surface thereof, for example, 100 to 2000 Newtons to obtain a plurality of lens preforms, and after cooling, a plurality of the lenses are obtained. 175; or (iii) nitrogen static pressure imprint: a plurality of the lenses 175 are imprinted by applying pressure to the back surface of the stamper relative to the molding surface thereof by nitrogen gas, and the pressure acting on the back surface of the stamper is due to the fact that nitrogen is a fluid. The distribution is relatively uniform, which in turn helps to improve the quality of the lens 175 that is ultimately formed. It should be noted that the surface shape design of the lens 175 may depend on the shape of the molding surface of the stamper.

Step (f): the semiconductor wafer 221, the spacer wafer 23, the transparent cover wafer 24, the spacer cell wafer 26, and the glass crystal on which the transparent nucleation layer 273 and the plurality of lenses 175 are sequentially formed The circle 271 is stacked one on another, and the adjacent two may be bonded together via an ultraviolet curing resin or a thermosetting resin (not shown) to bond the glass wafer 271 to the semiconductor wafer 221 Forming one side of the plurality of photosensitive regions 123; the plurality of photosensitive regions 123 and the glass wafer 271 are spaced apart and the plurality of photosensitive regions 123 are respectively located on the main optical axis O0' of the lens 175 corresponding thereto, thereby forming A wafer level miniature camera module array 100 (shown in Figure 3).

Step (g): Cutting the micro camera module array 100, a plurality of single micro camera modules 10 separated from each other can be obtained.

It should be noted that the order of steps (a) to (g) in this embodiment is merely an example, and is not intended to limit the present invention; those skilled in the art may appropriately change the order of steps (a) to (g). Only it does not deviate from the technical effects of the present invention.

Second embodiment

Referring to FIG. 4, a miniature camera module 30 according to a second embodiment of the present invention is substantially the same as the micro camera module 10 provided in the first embodiment, and includes an image sensing unit 12, a spacer layer 13, and a transparent a cover 14 , an infrared cut filter layer 15 , a spacer unit 16 , and a lens unit 17 . The image sensing unit 12 includes a semiconductor substrate 121 and a semiconductor substrate 121 . Photosensitive area 123 on one side. The difference is that the miniature camera module 30 further includes a lens unit 37 and another spacing unit 36 between the lens unit 37 and the lens unit 17. The lens unit 37 includes a glass substrate 371, a transparent nucleation layer 373 on the glass substrate 371, and a lens 375 on the transparent nucleation layer 373. The lens 375 of the lens unit 37 is disposed on the main optical axis OO' of the lens 175 of the lens unit 17, and the lens unit 37 is coupled with the lens unit 17 and is spaced apart from the lens unit 17 by the spacing unit 36. distance. The transparent nucleation layer 373 is substantially the same as the transparent nucleation layer 173 of the first embodiment, and therefore will not be described again. The lens 375 and the lens 175 can be spherical, aspherical or folded plastic lenses. The arrangement of the double lens unit 17 facilitates the correction of optical aberrations, thereby improving the imaging quality of the entire miniature camera module 30.

In addition, it can be understood by those skilled in the art that the micro camera module 30 in this embodiment is not limited to only including two lens units, and may further include more lens units, and the specific number may be according to actual application requirements. set.

Referring to FIG. 5 , the micro camera module 30 is manufactured in substantially the same manner as the micro camera module 10 . The difference is that the micro camera module 30 has a dual lens unit structure and is configured in the micro camera module. In the manufacturing process of 30, a glass wafer 471 on which a transparent nucleation layer 473 and a plurality of lenses 375 are sequentially formed, and another spacer unit wafer 46 are further provided. The transparent nucleation layer 473 and the spacer unit wafer 46 are substantially the same as the transparent nucleation layer 273 and the spacer unit wafer 26 in the manufacturing method of the micro camera module 10, and will not be described herein.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. but, The above is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Micro Camera Module

12‧‧‧Image sensing unit

121‧‧‧Semiconductor substrate

123‧‧‧Photosensitive area

13‧‧‧ spacer

14‧‧‧Transparent cover

15‧‧‧Infrared cut filter

16‧‧‧Interval unit

17‧‧‧ lens unit

171‧‧‧ glass substrate

173‧‧‧Transparent nucleation layer

175‧‧‧ lens

Claims (9)

A miniature camera module includes: an image sensing unit including a photosensitive area; a first lens unit coupled to one side of the image sensing unit adjacent to the photosensitive area, the lens unit including a glass a substrate, a transparent nucleation layer on the glass substrate, and a lens on the transparent nucleation layer, the lens having a main optical axis disposed on a main optical axis of the lens and The lens unit is spaced apart; a transparent cover having a filter layer formed on the surface thereof; and a black annular spacer unit; wherein the transparent cover is coupled between the image sensing unit and the first lens unit for sealing Covering the photosensitive area; the black annular spacer unit is coupled between the transparent cover and the first lens unit for spacing the transparent cover and the first lens unit. The micro camera module of claim 1, wherein the material of the transparent nucleation layer is an inorganic transparent material different from glass. The micro camera module of claim 2, wherein the material of the transparent nucleation layer is tantalum oxide or titanium dioxide. The miniature camera module of claim 2, wherein the lens is a plastic lens. The miniature camera module of claim 1, further comprising an annular spacer layer coupled between the image sensing unit and the first lens unit for spacing the photosensitive region and the Lens unit. The micro camera module of claim 1, further comprising a second lens unit coupled to the side of the first lens unit away from the image sensing unit and Separating from the first lens unit by a predetermined distance; the second lens unit comprises a glass substrate, a transparent nucleation layer on the glass substrate, and a lens on the transparent nucleation layer; the second The lens of the lens unit is disposed on a main optical axis of the lens of the first lens unit. A method for fabricating a miniature camera module, comprising the steps of: providing a semiconductor wafer formed with a plurality of photosensitive regions; providing a transparent cover wafer; providing a black spacer unit wafer on the black spacer unit wafer Forming a plurality of through holes; providing a glass wafer having a transparent nucleation layer and a plurality of lenses formed on the transparent nucleation layer via an embossing process, the plurality of lenses respectively having a main optical axis; The semiconductor wafer, the transparent cover wafer, the black spacer cell wafer, and the glass wafer are sequentially stacked, and the glass wafer is bonded to the semiconductor wafer to form the plurality of photosensitive regions. One side, the plurality of photosensitive regions are spaced apart from the glass wafer and the plurality of photosensitive regions are respectively located on a main optical axis of the lens corresponding thereto, thereby forming a wafer level micro camera module array; and cutting the micro camera The module array is used to obtain a plurality of individual micro camera modules separated from each other. The method of fabricating the miniature camera module of claim 7, wherein the material of the transparent nucleation layer is an inorganic transparent material different from glass, and the lens is a plastic lens. The method for manufacturing a miniature camera module according to claim 7, wherein the imprinting process is one selected from the group consisting of ultraviolet embossing, hot embossing, and nitrogen static embossing.