Image sensor packaging structure

Abstract

The invention relates to an image sensor packaging structure. The image sensor packaging structure comprises an image sensing wafer, a metal bank and a light-transmitting substrate, an active surface of a wafer body of the image sensing wafer comprises a light sensing area on which a light sensing layer is formed and a non-sensing area surrounding the light sensing area; the metal bank is formed on the non-induction area in an electric insulation manner, surrounds the light sensing layer, keeps a distance from the light sensing layer, and has a thickness; the surface of the light-transmitting substrate is provided with a glue bank corresponding to the metal bank so as to align and adhere to the metal bank, and the thickness of the glue bank is smaller than that of the metal bank. Therefore, compared with the existing full-glue embankment, the combined structure of the metal embankment and the glue embankment has the advantages that the use amount of the glue of the glue embankment and the residual glue overflowing inwards can be effectively reduced, and the yield of the packaging structure of the image sensor is improved.

Description

Technical Field

[0001] The present invention relates to a semiconductor packaging structure, in particular to an image sensor packaging structure. Background Art

[0002] See also Figure 5 In the manufacturing process of the conventional image sensor packaging structure, a liquid adhesive is formed on a transparent substrate 40 to form an adhesive dam 50, and then an active surface 61 of an image sensor chip 60 is directed toward the surface 41 of the transparent substrate 40, and the light sensing layer 62 of the image sensor chip 60 is located within the range of the adhesive dam 50; Figure 6 As shown, the image sensor chip 60 is pressed downward and bonded to the adhesive dam 50 so as to be spaced apart from the transparent substrate 40 .

[0003] When the image sensor chip 60 is pressed down and bonded to the adhesive dam 50, since the adhesive dam 50 is still in liquid state, the downward pressure of the image sensor chip 60 will squeeze the adhesive dam 50, causing it to overflow inward and outward. If the residual adhesive 51 overflows to the photosensitive layer 62 on the active surface 61 of the image sensor chip 60, it will contaminate the photosensitive layer 62, resulting in a poor yield of the existing image sensor packaging structure, so it is necessary to improve it. Summary of the invention

[0004] In view of the above-mentioned disadvantage that the residual glue of the glue dam of the conventional image sensor packaging structure may contaminate the light sensing layer on the active surface of the image sensor chip and thus result in poor yield, the present invention proposes an improved image sensor packaging structure to improve the yield.

[0005] To achieve the above-mentioned purpose, the main technical means used by the present invention is to make the above-mentioned image sensor packaging structure include:

[0006] An image sensing chip, wherein a chip body comprises two opposite active surfaces and a back surface; wherein the active surface comprises a light sensing area and a non-sensing area surrounding the light sensing area, and a light sensing layer is disposed on the light sensing area;

[0007] A metal dam is electrically insulated and formed on the non-sensing area of ​​the active surface of the chip body, surrounds the photosensitive layer, and keeps a distance from the outer side surface of the photosensitive layer; wherein the metal dam has a first thickness; and

[0008] A transparent substrate has a surface facing the active surface of the chip body and a glue dam is arranged corresponding to the metal dam to align and bond to the metal dam; wherein the glue dam has a second thickness which is smaller than the first thickness.

[0009] As can be seen from the above description, the image sensor packaging structure of the present invention mainly forms the metal dam on the non-sensing area of ​​the active surface of the chip body of the image sensor chip in an electrically insulated manner, and sets the glue dam on the surface of the transparent substrate corresponding to the metal dam, so that the glue dam is aligned and bonded to the metal dam, and the second thickness of the glue dam is less than the first thickness of the metal dam; thus, the combined structure of the metal dam and the glue dam of the present invention can effectively reduce the amount of glue used in the glue dam compared to the existing full glue dam, and is more helpful to solve the problem of inward overflow of the liquid glue dam during the manufacturing process, thereby effectively improving the yield of the image sensor packaging structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 : A cross-sectional view of a first embodiment of an image sensor packaging structure of the present invention.

[0011] Figure 2 : Figure 1 A partial enlarged view of the F area.

[0012] Figure 3 : A partially enlarged cross-sectional view of a second embodiment of the image sensor packaging structure of the present invention.

[0013] Figure 4 : A cross-sectional view of a third embodiment of the image sensor packaging structure of the present invention.

[0014] Figure 5 : A cross-sectional view of an existing image sensor packaging structure showing an image sensor chip before being pressed down and bonded to a transparent substrate.

[0015] Figure 6 : A cross-sectional view of an existing image sensor packaging structure after an image sensor chip is pressed down and bonded to a transparent substrate.

[0016] Wherein, the reference numerals are:

[0017] 10: Image sensor chip 11: Chip body

[0018] 12: Active surface 120: Photosensitive layer

[0019] 121: Outer side 122: Light sensing area

[0020] 123: Non-sensing area 13: Back side

[0021] 14: Conductive through hole 15: Inner metal pad

[0022] 16: External connector 17: External metal pad

[0023] 18: Circuit layer 181: Insulation layer

[0024] 182: Metal circuit 183: Passivation layer

[0025] 184: Dielectric layer 19: Rewiring layer

[0026] 20: Metal dam 21: Light absorption layer

[0027] 30: light-transmitting substrate 31: surface

[0028] 32: Rubber dam 40: Translucent substrate

[0029] 41: Surface 50: Rubber embankment

[0030] 51: overflow residual glue 60: image sensor chip

[0031] 61: Active surface 62: Photosensitive layer DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

[0033] The present invention provides an improved image sensor packaging structure. The technical content of the present invention is described in detail below with reference to a plurality of embodiments and drawings.

[0034] See also Figure 1 , which is a first embodiment of the image sensor package structure of the present invention, includes an image sensor chip 10 , a metal dam 20 and a transparent substrate 30 .

[0035] Please continue reading Figure 1 A chip body 11 of the image sensor chip 10 includes an active surface 12, a back surface 13 opposite to the active surface 12, and a photosensitive layer 120. The active surface 12 includes a photosensitive area 122 and a non-sensing area 123, wherein the non-sensing area 123 surrounds the photosensitive area 122. The photosensitive layer 120 is disposed on the photosensitive area 122 of the active surface 12.

[0036] See also Figure 1 and Figure 2In one embodiment, the image sensor chip 10 may further include a plurality of conductive through holes 14, a plurality of inner metal pads 15, a plurality of outer metal pads 17, a plurality of external connectors 16 and a circuit layer 18. The conductive through holes 14 are formed through the chip body 11 and are located in the non-sensing area 123 of the active surface 12. The inner metal pads 15 are formed on the active surface 12 of the chip body 11 and are respectively connected to the conductive through holes 14. The outer metal pads 17 are formed on the back side 13 of the chip body 11 corresponding to the conductive through holes 14 and are respectively connected to the conductive through holes 14. The external connectors 16 are respectively formed on the outer metal pads 17; in one embodiment, each of the external connectors 16 may be a solder ball or a metal bump, but is not limited thereto. In combination with Figure 2 As shown, the circuit layer 18 is formed on the active surface 12 of the chip body 11 to electrically connect the photosensitive layer 120 and the inner metal pads 15, and the circuit layer 18 includes a plurality of metal circuits 182 and an insulating layer 181; wherein the metal circuits 182 are formed on the active surface 12 and connect the photosensitive layer 120 and the inner metal pads 15, and the insulating layer 181 covers the metal circuits 182; in one embodiment, the insulating layer 181 includes a passivation layer 183 and a dielectric layer 184, that is, the passivation layer 183 first covers the metal circuits 182, and the dielectric layer 184 is then formed on the passivation layer 183.

[0037] Please continue reading Figure 1 and Figure 2 The metal dam 20 is electrically insulated and formed on the non-sensing area 123 of the active surface 12 of the chip body 11 of the image sensor chip 10, and surrounds the photosensitive layer 120, and is kept away from an outer side surface 121 of the photosensitive layer 120, and the metal dam 20 has a first thickness T1. Specifically, Figure 2 As shown, the metal dam 20 can be formed on the dielectric layer 184 of the insulating layer 181 of the circuit layer 18 of the image sensor chip 10, so the metal dam 20 can be electrically insulated from the metal circuits 182, the inner metal pads 15 and the conductive through holes 14 located in the non-sensing area 123, and the material of the metal dam 20 can be electroless metal. In this embodiment, the first thickness T1 can be about 30μm, but is not limited thereto. Figure 2 and Figure 3 As shown, in one embodiment, the exposed surface of the metal dam 20 may form a light absorbing layer 21, especially toward Figure 2The surface of the photosensitive layer 120 is shown; preferably, the light absorbing layer 21 can be an oxide metal layer or a black light absorbing layer to prevent the metal dam 20 from reflecting light and causing light sensing noise. In addition, the melting point of the metal material used for the metal dam 20 can be higher than or equal to 300°C, such as copper, to prevent the metal dam 20 from melting during the reflow process of the image sensor packaging structure.

[0038] The transparent substrate 30 is disposed on the image sensor chip 10 at intervals, and a surface 31 of the transparent substrate 30 faces the active surface 12 of the chip body 11 of the image sensor chip 10. A glue dam 32 is disposed on the surface 31 corresponding to the metal dam 20. The glue dam 32 is aligned with and bonded to the metal dam 20, so that the transparent substrate 30 can be bonded to the image sensor chip 10 at intervals. Figure 2 and Figure 3 The adhesive dam 32 has a second thickness T2, wherein the percentage of the second thickness T2 to the sum T3 of the first and second thicknesses T1 and T2 may be approximately between 14.3% and 25%; in other words, the second thickness T2 may be approximately between 5 μm and 10 μm, but is not limited thereto. In this embodiment, if Figure 2 As shown, the second thickness T2 may be approximately 5 μm; in one embodiment, as Figure 3 In one embodiment, the transparent substrate 30 and the chip body 11 have the same lateral dimensions, so the outer side of the transparent substrate 30, the outer side of the glue dam 32 and the outer side of the metal dam 20 are flush with the outer side of the chip body 11.

[0039] Please see again Figure 4 , is a second embodiment of the image sensor packaging structure of the present invention, and its structure is similar to Figure 1 The structure of the first embodiment of the present invention is substantially the same as that of the first embodiment of the present invention, except that the back surface 13 of the chip body 11 of the image sensor chip 10 is not formed as shown in FIG. Figure 1 The outer metal pads 17 shown further form a redistribution layer 19 to connect with the conductive through-holes 14 . The outer connectors 16 are formed on the redistribution layer 19 . Therefore, the redistribution layer 19 connects the conductive through-holes 14 and the outer connectors 16 .

[0040] As can be seen from the above description, the image sensor packaging structure of the present invention mainly forms the metal dam on the non-sensing area of ​​the active surface of the chip body of the image sensor chip in an electrically insulated manner, and sets the glue dam on the surface of the transparent substrate corresponding to the metal dam, so that the glue dam is aligned and bonded to the metal dam, and the second thickness of the glue dam is less than the first thickness of the metal dam; thus, the combined structure of the metal dam and the glue dam of the present invention can effectively reduce the amount of glue used in the glue dam compared to the existing full glue dam, and is more helpful to solve the problem of inward overflow of the liquid glue dam during the manufacturing process, thereby effectively improving the yield of the image sensor packaging structure.

[0041] The above description is only an embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above by the embodiment, it is not used to limit the present invention. Any person with ordinary knowledge in the technical field can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An image sensor packaging structure, characterized in that: Include: An image sensing chip, wherein a chip body comprises two opposite active surfaces and a back surface; wherein the active surface comprises a light sensing area and a non-sensing area surrounding the light sensing area, and a light sensing layer is disposed on the light sensing area; A metal dam is electrically insulated and formed on the non-sensing area of ​​the active surface of the chip body, surrounds the photosensitive layer, and keeps a distance from the outer side surface of the photosensitive layer; wherein the metal dam has a first thickness; and A transparent substrate has a surface facing the active surface of the chip body and a glue dam is arranged corresponding to the metal dam to align and bond to the metal dam; wherein the glue dam has a second thickness which is smaller than the first thickness.

2. The image sensor package structure as claimed in claim 1, wherein: The percentage of the second thickness to the sum of the first thickness and the second thickness is between 14.3% and 25%.

3. The image sensor package structure as claimed in claim 2, wherein: The first thickness is 30 μm, and the second thickness is between 5 μm and 10 μm.

4. The image sensor package structure according to claim 1 or 2, wherein: The outer side of the chip body of the image sensing chip, the outer side of the metal dam, the outer side of the light-transmitting substrate and the outer side of the glue dam of the light-transmitting substrate are flush.

5. The image sensor package structure according to claim 1 or 2, wherein: The image sensor chip further comprises: A plurality of conductive through holes are formed through the chip body and are located in the non-sensing area; A plurality of inner metal pads are formed on the non-sensing area of ​​the active surface of the chip body and are respectively connected to the conductive through holes; as well as A circuit layer is formed on the active surface of the chip body, and the metal dam is electrically insulated and formed on the circuit layer; wherein the circuit layer includes: A plurality of metal circuits are formed on the active surface of the chip body and connect the light sensing layer and the inner metal pads; and An insulating layer is formed on the active surface of the chip body and covers the metal lines and is provided for the metal dam to be formed thereon.

6. The image sensor package structure as claimed in claim 5, wherein: The image sensor chip further comprises: A plurality of external metal pads are formed on the back surface of the chip body and are respectively connected to the conductive through holes; and A plurality of external connection members are respectively formed on the external metal pads.

7. The image sensor package structure as claimed in claim 5, wherein: A redistribution layer is further formed on the back side of the chip body of the image sensing chip, and a plurality of external connection members are formed on the redistribution layer; wherein the redistribution layer connects the conductive through holes and the external connection members.

8. The image sensor package structure as claimed in claim 5, wherein: The insulating layer of the circuit layer comprises: a passivation layer formed on the active surface of the chip body and covering the metal circuits; and A dielectric layer is formed on the passivation layer, and the metal dam is formed on the dielectric layer.

9. The image sensor package structure according to claim 1 or 2, wherein: The exposed surface of the metal bank further forms a light absorbing layer.

10. The image sensor package structure as claimed in claim 5, wherein: The material of the metal bank is electroless metal.

11. The image sensor package structure as claimed in claim 10, wherein: The melting point of the metal material of the metal bank is higher than or equal to 300°C.

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