KR20030088887A - Miniature image sensing and processing module and manufacturing method thereof - Google Patents

Abstract

The present invention provides a compact image sensing and processing module and a method of manufacturing the same. After installing the image sensor package unit and the digital signal processor chip on the top and bottom surfaces of the substrate, respectively, the lens holder is mounted on the substrate to surround the top of the image sensor package unit. Since the packaged part is an image sensor package unit, the wires of the image sensor chip will not be damaged during assembly of the lens holder, providing improved reliability to the module structure as well as preventing particles from contaminating the chip. Therefore, the present invention achieves the result that it is easy to integrate and automate production with the aim of minimizing volume. It also offers the advantage of being easy to manufacture, high yield and easy to rework.

Description

Miniature image sensing and processing module and its manufacturing method {MINIATURE IMAGE SENSING AND PROCESSING MODULE AND MANUFACTURING METHOD THEREOF}

The present invention relates to an image sensing module, and more particularly, to a structure of a compact image sensing and processing module and a method of manufacturing the module.

In general, various mobile electronic products such as cellular phones, PDAs and digital cameras have functions for network transmission of multimedia information and multimedia applications. In that regard, as image transfer becomes popular, photography has become increasingly part of the life of mobile communications. Palm-size devices with built-in digital cameras, such as PDAs and cellular phones, can take pictures or transfer images at any time, making our daily lives easier and more enjoyable.

To meet the requirements of embedded digital cameras, the miniaturization of image sensing and processing modules is critical. The superposition of the image sensor chip and the digital signal processor (DSP) chip with each other is advantageous for miniaturization purposes. The prior art achieves this goal using Chip On Board (COB) technology. In the conventional method, referring to FIG. 1, first, the DSP chip 12 is fixed to a flexible printed circuit board (FPC) 10. Next, the image sensor chip 13 is fixed to the DSP chip 12. Subsequently, a wire bonding process is performed by using a plurality of gold wires 16 to electrically interconnect the chips 12 and 14 and the flexible printed circuit board 10. Finally, the lens holder 18 is fixed on the flexible printed circuit board 10 after covering the lens holder 18. However, this technique has several disadvantages. (1) Since the image sensor chip 14 is fixed to the DSP chip 12 by using an adhesive, especially when the size of the image sensor chip 14 is larger than the DSP chip 12, the image sensor 14 It may miss or fall out. (2) Since these two chips 12 and 14 are covered by the molding compound, the height and width of the entire module will be large. Moreover, the molding process cannot be performed because the molding compound should not cover the photosensitive area on the top surface of the image sensor chip 14. Thus, the molding process is omitted in the prior art. In addition, in the prior art, the gold wire 16 may be damaged during assembly of the lens holder 18 and may cause particle contamination on the image sensor chip 14. As a result, production yields will be severely impaired and will affect production efficiency. (3) The reliability is low because the module is protected only by combining the lens holder 18 and the FPC 10. (4) The test can be performed only after the lens holder 18 is assembled. If the chip fails, the entire module must be destroyed because regeneration is not possible.

Another conventional technique shown in FIG. 2 is to fix the DSP chip 12 on the lower surface of the flexible printed circuit board 10, and then perform a wire bonding and molding process on the DSP chip, and then an image sensor on the upper surface of the FPC 10. After fixing the chip 14, a wire bonding process of the image sensor chip 14 is performed, and finally the lens holder is assembled by fixing the lens holder 18 on the FPC 10. This assembly technique may protect the DSP chip 12 with the molding compound 20. However, the image sensor chip 14 is not protected due to the above limitations. Since this technique requires the manufacture of a mold for the molding process for the DSP chip 12, the manufacturing process becomes more complicated and additional costs are incurred. More seriously, this technique also has the same problems as in (2), (3) and (4).

Therefore, in order to solve the above problems, the present invention provides a structure of a compact image sensing and processing module and a method of manufacturing the same, which can solve various disadvantages of the prior art.

It is a main object of the present invention to provide a structure of a compact image sensing and processing module and a method for manufacturing the same, which can achieve an easy result to integrate and automate production, with the aim of volume minimization.

Another object of the present invention is to assemble the image sensor package unit on the substrate to prevent damage to the wire during the assembly of the lens holder and to prevent the contamination of the chip by the particles, high reliability small image detection and processing module To provide the structure.

Another object of the present invention is to provide the advantages of easy to manufacture, high yield, and easy to recycle, by applying to the process and equipment currently used in the packaging factory.

In order to achieve the above object, a compact image sensing and processing module is fabricated by assembling a digital signal processor chip on the bottom surface of a substrate. The electrical signal is then electrically interconnected between the digital signal processor chip and the substrate, and then the image sensor package unit is assembled on the top surface of the substrate and the image sensor package unit and the substrate are electrically interconnected. Finally, the lens holder is installed on the substrate to surround the outside of the image sensor package unit.

The objects, related techniques, advantages and effects thereof will be more readily understood with reference to the following description of the embodiments of the present invention and examples of the drawings.

1 is a cross-sectional view of a prior art image sensing and processing module.

2 is a cross-sectional view of another prior art image sensing and processing module.

3 to 5 are cross-sectional views of each process of manufacturing the miniature image sensing and processing module of the present invention.

Description of the main parts of the drawing

32: substrate

34: digital signal processor chip

36: bump

38: molding compound

40: image sensor package unit

402: installation room

404: upper window

406: image sensor chip

3 to 5 are cross-sectional views of each step of the process of manufacturing the miniature image sensing and processing module of the present invention. First, reference is made to FIG. 5 which schematically shows the structure of the present invention. The miniature image sensing and processing module 30 preferably comprises a substrate 32, which is a flexible printed circuit board (FPC), and a digital signal processor (DSP) chip 134, wherein the DSP chip includes a bump 36; And electrically interconnected with the substrate 32 to form flip chips on the bottom surface of the substrate 32. The molding compound 38 is filled around the bump 36, the image sensor package unit 40 is assembled on the top surface of the substrate 32, and the image sensor package unit and the substrate 32 are electrically interconnected. The image sensor package unit 40 includes an installation chamber 402, an upper window 404, and an image sensor chip 406, which are assembled inside the installation chamber 402 and using wire bonding. It is electrically interconnected with the lower part of the installation chamber 402. The photosensitive area of the image sensor chip 406 faces upward through the window 404 and covers the upper window 404 with a transparent cap 408, usually made of plastic or glass, to prevent the image sensor chip 406 from contamination or damage. Sealing the installation room 402 to protect the wires and wires and reduce the impact of the environment. The lens holder 42 surrounds the outside of the image sensor package unit 40, and the optical lens 44 is installed on the upper side of the lens holder 42, and the lens holder 42 is formed of the substrate 32 by an adhesive material. And are fixed.

After understanding the overall structure of the present invention, reference is made to FIGS. 3 to 5 to understand its manufacturing method and the structure of each layer. First, as shown in FIG. 3, a method of manufacturing a small image sensing and processing module includes the following steps, the first step of providing a substrate 32 and a digital signal processor (DSP) chip 34. Step. The substrate 32 is usually a flexible printed circuit board (FPC), and a plurality of solder pads are provided in advance on the surface of the DSP chip 34 as connection points of the I / O signals (not shown in FIG. 3). An electrically conductive bump 36 is formed on each solder pad of the DSP chip 34. The DSP chip 34 is formed as a flip chip on the substrate 32 using the bumps 36. The molding compound 38 is then filled in the gap between the DSP chip 34 and the substrate 32 by scanning the adhesive.

After assembling the DSP chip 34 on the substrate 34, the top of the substrate 32 is faced downward so that the DSP chip 34 is located on the bottom surface of the substrate 32, as shown in FIG. The image sensor package unit 40 is mounted on the top surface of the substrate 32 by surface mount technology (SMT). In that regard, the image sensor package unit may typically be a plastic leadless chip carrier (PLCC) and a ceramic leadless chip carrier (CLCC) consisting of an installation chamber 402, an image sensor chip 406, and a transparent cap 408. . Through PLCC packaging, after the electrical signal of the image sensor chip 406 is conducted to the internal lead of the PLCC installation chamber 402, the electrical signal is connected to the internal lead of the PLCC installation chamber 402 and the external lead. The external lead wires are electrically connected to the substrate 32 by the SMT process. After assembling the image sensor package unit 40, as shown in FIG. 5, the substrate holder 32 surrounds the outside of the image sensor package unit 40 with the lens holder 42 having the lens 44 on the upper side. ), The entire assembly process is completed. As a result, a small image sensing and processing module 30 is formed.

In the present invention, the production yield of PLCC or CLCC is about 95%, and about 99.9% for the flip chip process of DSP chip 34, such as SMT. The yield of the whole production process is above 94%. However, about 50% of the prior art COB manufacturing process. The present invention achieves both the advantages of being easy to manufacture and of high yield using the manufacturing processes and equipment currently used on the production line of the packaging factory. Furthermore, since the present invention mounts the image sensor package unit 40 on the substrate 32 and covers the upper portion of the image sensor chip 406 with the transparent cap 48, the interior of the image sensor package unit 408 Both damage to the gold wire and particle contamination of the image sensor chip 406 are avoided, providing high yield and high productivity gains. In addition, the image sensor package unit 40 is highly reliable because it is a fully packaged carrier, thus effectively reducing the disadvantages of the low reliability of prior art modules that block external environments only by the combination between the lens holder and the printed circuit board. .

In addition, the present invention may perform the first test after each step of completing the DSP chip 34 as a flip chip and completing the installation of the image sensor package unit 40. The final test can be performed after the lens holder 42 is assembled. If one of the DSP chip 34 and the image sensor package unit 40 is defective, only the defective one is replaced and then reworked. This approach solves the problem of the prior art, in which the entire module had to be discarded because regeneration was not possible.

Accordingly, the compact image sensing and processing module provided by the present invention achieves the purpose of volume minimization, the effect of easy to integrate and automate production, the assembly advantage of high yield and easy reproduction, and maintenance of product reliability. . This relates to various disadvantages of the prior art.

The above has described the features of the present invention through the examples. Its purpose is to enable those skilled in the art to understand and practice the contents of the present invention. However, this does not limit the claims of the present invention. Accordingly, those skilled in the art can make various modifications without departing from the subject matter defined only by the appended claims.

Claims (18)

Compact image sensing and processing module A substrate; A digital signal processor chip assembled on a bottom surface of the substrate and electrically interconnected with the substrate; An image sensor package unit assembled on an upper surface of the substrate and electrically interconnected with the substrate; Lens holder assembled on the substrate and surrounding the outside of the image sensor package unit Small image detection and processing module comprising a. The method of claim 1, wherein the image sensor package unit, An installation room with an upper window, An image sensor chip comprising: an image sensor chip assembled within the installation chamber and electrically interconnected with a lower portion of the installation chamber, wherein the photosensitive region of the image sensor chip faces upward through the upper window; Transparent cap that is assembled on the upper window of the installation chamber to seal the installation chamber The miniature image detection and processing module comprising a. The miniature image sensing and processing module of claim 2, wherein the image sensor chip is electrically interconnected with a lower portion of the installation chamber using a wire bonding method. The miniature image sensing and processing module of claim 2, wherein the material of the transparent cap is selected from glass and plastic. The miniature image sensing and processing module of claim 1, wherein the substrate is a printed circuit board. The miniature image sensing and processing module of claim 1, wherein the substrate is a flexible printed circuit board. The miniature image sensing and processing module of claim 1, wherein the digital signal processor chip is formed as a flip chip on a bottom surface of the substrate using a plurality of bumps. 8. The miniature image sensing and processing module of claim 7, wherein a molding compound is filled around the bumps. The miniature image sensing and processing module of claim 1, wherein an adhesive material is used at the connection site between the lens holder and the substrate. A method of manufacturing a compact image sensing and processing module, Providing a substrate and assembling a digital signal processor chip on a bottom surface of the substrate; Assembling an image sensor package unit on an upper surface of the substrate; Assembling a lens holder to surround the outside of the image sensor package unit. Small image detection and processing module manufacturing method comprising a. The method of claim 10, wherein the image sensor package unit, An installation room with an upper window, An image sensor chip comprising: an image sensor chip assembled within the installation chamber and electrically interconnected with a lower portion of the installation chamber, wherein the photosensitive region of the image sensor chip faces upward through the upper window; And a transparent cap assembled on the upper window of the installation chamber to seal the installation chamber. The method of claim 11, wherein the image sensor chip is electrically interconnected with a lower portion of the installation chamber using a wire bonding method. 12. The method of claim 11 wherein the material of the transparent cap is selected from glass and plastic. The method of claim 10, wherein the substrate is a printed circuit board. The method of claim 10, wherein the substrate is a flexible printed circuit board. The method of claim 10, wherein installing the digital signal processor chip comprises forming a flip chip on a bottom surface of the substrate using a plurality of bumps. 17. The method of claim 16, further comprising, after the digital signal processor chip installation step, filling a molding compound around the bumps. 12. The method of claim 10 wherein the step of installing the image sensor package unit is performed by using surface mount technology (SMT).