CMOS image sensor package structure

Abstract

The application provides a CMOS image sensor packaging structure, which comprises an image sensor chip and metal wires electrically connected to the image sensor chip, a first end of the metal wires is bonded to a pad of the image sensor chip, and a second end of the metal wires is suspended in the image sensor chip; the metal wires comprise a first wire arc bonded to the image sensor chip, a second wire arc extending from the second end to the image sensor chip, and a middle wire arc connected to the first wire arc and the second wire arc; and an included angle between the middle wire arc and the second wire arc in an anticlockwise direction is less than 180 degrees. The application changes the wire type of the metal wires, increases the elasticity of the metal wires, so that the metal wires can well absorb the influence caused by the warping of the FPC, and the occurrence of false welding is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of image sensor, in particular to a CMOS image sensor packaging structure. BACKGROUND

[0002] The image sensor is in the form of image sensor chip to play its function of sensing optical image information and converting it into a usable output signal. The image sensor chip is vulnerable to pollution from the outside environment during operation, so the image sensor chip needs to be packaged to make the image sensor chip in a sealed environment, thereby avoiding the influence of the outside environment on the image sensor chip, thereby improving the performance and service life of the image sensor chip.

[0003] At present, all image sensor chip packaging adopts production line packaging of extremely clean environment, high pollution complex process equipment and materials, mainly including chip on board (COB), chip scale package (CSP) and flip chip (FC).

[0004] In addition, Chinese invention patent application: CN 201510641103.0 discloses a kind of assembly method of camera module, discloses a new CIS (CMOS Image Sensor) packaging method, which comprises: providing image sensor chip with suspended metal wire, the first end of the metal wire is bonded to the pad of the image sensor chip, and the second end is suspended in the image sensor chip;The image sensor chip and lens module are assembled to form a standard part, and then the standard part and the circuit board are assembled to form a camera module through the second end of the metal wire.This kind of packaging method has many advantages such as low module height, good packaging reliability, excellent optical performance, small module inclination error and small cost compared with COB and CSP.The core of this packaging method is to make a metal wire with one end bonded to the pad of the image sensor chip and the other end suspended.When the chip with this packaging structure is mounted on the flexible circuit board, the metal wire needs to touch the pad of the circuit board, but the FPC (flexible circuit board) has warping, when the FPC warping is large, the gold wire cannot completely contact the pad of the FPC, and during the welding process, it will bring about about 0.5% or more product false welding, affecting the reliability of the product. SUMMARY

[0005] The purpose of the present application is to provide a CMOS image sensor packaging structure, to avoid the influence of FPC warping on welding, and to improve packaging efficiency and yield.

[0006] Based on the above considerations, the application provides a CMOS image sensor packaging structure, comprising: an image sensor chip and a metal wire electrically connected with the image sensor chip, characterized in that a first end of the metal wire is bonded to a pad of the image sensor chip, and a second end of the metal wire is suspended in the image sensor chip; the metal wire comprises a first wire arc bonded to the image sensor chip, a second wire arc extending from the second end to the image sensor chip, and a middle wire arc connected to the first wire arc and the second wire arc; wherein the included angle between the middle wire arc and the second wire arc in the counterclockwise direction is less than 180°.

[0007] Optionally, the middle wire arc is in a straight line or a curve.

[0008] Optionally, the middle wire arc is in a straight line, and the included angle between the middle wire arc and the horizontal direction is 50-80°.

[0009] Optionally, the included angle between the second wire arc and the horizontal direction is 10-23°.

[0010] Optionally, the middle arc is in an M shape or a V shape or an S shape.

[0011] Optionally, the metal wire is a gold wire.

[0012] Optionally, the second end is attached with a solder layer.

[0013] The CMOS image sensor packaging structure of the application has the following beneficial effects:

[0014] By changing the wire type of the metal wire, the elasticity of the metal wire is increased, so that the metal wire can well absorb the influence of the warping of the FPC, and the occurrence of false welding is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Other features, objects and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings.

[0016] Figure 1 A schematic diagram of the CMOS image sensor packaging structure provided in Example 1 is shown.

[0017] Figure 2 A schematic diagram of the CMOS image sensor packaging structure provided in Example 2 is shown.

[0018] Figure 3 A schematic diagram of the CMOS image sensor packaging structure provided in Example 3 is shown.

[0019] Figure 4 A schematic diagram of the CMOS image sensor packaging structure provided in Example 4 is shown.

[0020] Throughout the figures, the same or similar reference numerals denote the same or similar devices (modules) or steps. Detailed Implementation

[0021] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the present invention is described in detail using schematic diagrams. When describing the embodiments of the present invention in detail, the schematic diagrams are merely examples for ease of explanation and should not limit the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the method of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] Example 1

[0025] like Figure 1 As shown, the present invention provides a CMOS image sensor packaging structure, including: an image sensor chip 101 and a metal wire electrically connected to the image sensor chip 101. The first end 11 of the metal wire is bonded to the pads of the image sensor chip 101, and the second end 12 is suspended from the image sensor chip 101. The metal wire includes a first arc 13 bonded to the image sensor chip, a second arc 14 extending from the second end 12 toward the image sensor chip 101, and an intermediate arc 15 connecting the first arc 13 and the second arc 14. The angle α between the intermediate arc 15 and the second arc 14 in the counterclockwise direction is less than 180°.

[0026] The intermediate arc can be straight, curved, or other shapes. In this embodiment, such as... Figure 1 As shown, the middle arc 15 is a straight line. In other embodiments, the middle arc can also be curved or other shapes, such as M-shaped, V-shaped or S-shaped, which can be set as needed.

[0027] Preferably, the angle β between the intermediate arc 15 and the horizontal direction is 50~80°. Preferably, the angle γ between the second arc 14 and the horizontal direction is 10~23°. By increasing the angle β between the intermediate arc 15 and the horizontal direction or decreasing the angle γ between the second arc 14 and the horizontal direction, the elasticity of the metal conductor is increased. Moreover, by setting the second arc 14 to be closer to the horizontal, it can make better contact with the FPC board, increasing the welding yield.

[0028] The metal conductor can be gold wire or other metal wire. Preferably, gold wire is used as the metal conductor.

[0029] The second end of the metal wire can be attached with a solder layer, which facilitates the subsequent mounting of the packaged chip onto the flexible circuit board.

[0030] Example 2

[0031] This embodiment provides a CMOS image sensor packaging structure, which is basically the same as the technical solution of Embodiment 1. The difference from Embodiment 1 is that the middle line segment is curved and M-shaped.

[0032] like Figure 2 As shown, the middle arc 25 is M-shaped. Other technical solutions are the same as in Embodiment 1 and will not be repeated here. The M-shaped middle arc can significantly increase the overall elasticity of the metal conductor.

[0033] By changing the shape of the metal conductors and increasing their elasticity, the enhanced elasticity of the metal conductors can effectively absorb the effects of FPC warpage during the subsequent mounting of the packaged chip onto the FPC, reducing the occurrence of cold solder joints.

[0034] Example 3

[0035] This embodiment provides a CMOS image sensor packaging structure, which is basically the same as the technical solution of Embodiment 1. The difference from Embodiment 1 is that the middle line segment is curved, specifically V-shaped.

[0036] like Figure 3 As shown, the middle arc 35 is V-shaped. Other technical solutions are the same as in Embodiment 1, and will not be repeated here. The V-shaped middle arc greatly increases the overall elasticity of the metal conductor.

[0037] By changing the shape of the metal conductors and increasing their elasticity, the enhanced elasticity of the metal conductors can effectively absorb the effects of FPC warpage during the subsequent mounting of the packaged chip onto the FPC, reducing the occurrence of cold solder joints.

[0038] Example 4

[0039] This embodiment provides a CMOS image sensor packaging structure, which is basically the same as the technical solution of Embodiment 1. The difference from Embodiment 1 is that the middle line segment is curved, specifically S-shaped.

[0040] like Figure 4 As shown, the middle arc 45 is S-shaped. Other technical solutions are the same as in Embodiment 1 and will not be repeated here. The S-shaped middle arc greatly increases the overall elasticity of the metal conductor.

[0041] By changing the line type of the metal wire and increasing the elasticity of the metal wire, the elasticity of the metal wire can well absorb the influence of the warping of the FPC in the subsequent process of mounting the packaged chip on the FPC, and the occurrence of false welding is reduced.

[0042] In conclusion, the application provides a CMOS image sensor packaging structure, by changing the line type of the metal wire and increasing the elasticity of the metal wire, so that the metal wire can well absorb the influence of the warping of the FPC, and the occurrence of false welding is reduced.

[0043] It will be obvious to a person skilled in the art that the application is not limited to the details of the above-described exemplary embodiments, but that the application can be implemented in other concrete forms without departing from the spirit or the essential characteristics of the application. The embodiments are therefore to be considered in all respects as illustrative and not restrictive. Furthermore, it is clear that the word "comprising" does not exclude other elements and steps and the word "a" or "an" does not exclude a plurality. A plurality of elements can also be presented by one element in device claims. The terms first, second and the like do not denote any ordinal number, but are used to distinguish different steps of the method.

Claims

1. A CMOS image sensor packaging structure, comprising an image sensor chip and metal wires electrically connected to the image sensor chip, characterized in that, The first end of the metal wire is bonded to the pad of the image sensor chip, and the second end is suspended above the image sensor chip. The metal wire includes a first arc bonded to the image sensor chip, a second arc extending from the second end toward the image sensor chip, and an intermediate arc connecting the first arc and the second arc. The second arc is positioned to be horizontal, and the angle γ between the second arc and the horizontal line is 10-23°. The angle β between the intermediate arc and the horizontal direction is greater than γ. This ensures that the second arc near the suspended end is closer to the horizontal than the end of the intermediate arc near the second arc, thereby improving contact with the FPC board and increasing the soldering yield. The angle α between the intermediate arc and the second arc in the counterclockwise direction is less than 180°.

2. The CMOS image sensor packaging structure according to claim 1, characterized in that, The intermediate line arc can be straight or curved.

3. The CMOS image sensor packaging structure according to claim 2, characterized in that, The intermediate arc is straight, and the angle between the intermediate arc and the horizontal direction is 50~80°.

4. The CMOS image sensor packaging structure according to claim 1 or 2, characterized in that, The angle between the second arc and the horizontal direction is 10~23°.

5. The CMOS image sensor packaging structure according to claim 2, characterized in that, The intermediate arc is M-shaped, V-shaped, or S-shaped.

6. The CMOS image sensor packaging structure according to claim 1, characterized in that, The metal wire is gold wire.

7. The CMOS image sensor packaging structure according to claim 1, characterized in that, The second end is attached with a solder layer.

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