TWM455258U - Image sensor structure with air gap - Google Patents

Description

Image sensor structure with air gap

The present invention is an image sensor structure, in particular, an image sensor structure having a gas chamber gap.

FIG. 1A is a schematic diagram showing the structure of a conventional image sensor. FIG. 1B is a schematic diagram showing the tilting of the optical unit and causing a crack in the manufacturing process of the conventional image sensor. FIG. 1C is a schematic diagram showing the tilting of the optical unit and the overflow of the glue during the manufacturing process of the conventional image sensor.

As shown in FIG. 1A, the conventional image sensor 100 is substantially composed of a circuit substrate 10 (eg, Printed Circuit Board, PCB), an image sensing chip 20 (Die), an optical unit 30 (eg, a light transmissive plate), and a package. The glue 40 is composed of. The image sensing chip 20 is disposed on the circuit substrate 10, and electrically connects the image sensing wafer 20 and the circuit on the circuit substrate 10 by the wire bonding method, and the optical unit 30 utilizes epoxy resin (Epoxy). The adhesive 29 covers the sensing area (not shown) of the image sensing wafer 20, and the periphery of the metal wire 25, the image sensing wafer 20, and the optical unit 30 are further encapsulated by the molding adhesive 40. Wrap it around.

However, as shown in FIG. 1B, if the amount or height of the adhesive 29 is different, the optical unit 30 adhered to the sensing region (not shown) of the image sensing wafer 20 during the mold-forming process. The unevenness of the placement (for example, left and right skew) will cause the tilt of the optical unit 30 relative to the image sensing wafer 20 or the circuit substrate 10 to be too large, which not only affects the sensing quality of the image sensor, but also enables molding. When the mold 50 is pressed in the molding process, the optical unit 30 is easily broken and lowered. The yield of the image sensor is manufactured.

In addition, as shown in FIG. 1C, when the mold-forming process is performed, the gas in the space surrounded by the optical unit 30, the image sensing wafer 20, and the adhesive 29 is heated by the high ambient temperature to cause unevenness. The increase in internal pressure caused by expansion and expansion not only pushes the optical unit 30 to cause the optical unit 30 to tilt, but also pushes the adhesive 29 outward to form an overflow, thereby reducing the yield of the image sensor.

The present invention is an image sensor structure having a gas chamber gap, comprising: a circuit substrate, an image sensing wafer, an adhesive layer and an optical unit. This creation can achieve the situation that the pressure of the air chamber is balanced by the pressure in the air chamber and the outside of the air chamber to avoid the internal pressure pushing the optical unit and the adhesive layer to cause the optical unit to tilt or overflow.

The present invention provides an image sensor structure having a gas chamber gap, comprising: a circuit substrate having a bearing surface and a bottom surface; the carrier surface is provided with a plurality of first conductive contacts; an image sensing wafer, The first surface is coupled to the bearing surface; the second surface has a sensing area; and the plurality of second conductive contacts are disposed on the outer side of the sensing area, and the second conductive The contacts are electrically connected to the first conductive contacts by a plurality of metal wires respectively; an adhesive layer is disposed on the second surface and the region between the sensing regions and the second conductive contacts is not covered And the optical unit is adhered to the second surface through the adhesive layer, and an air chamber is formed between the image sensing wafer and the optical unit, and the air chamber communicates with the outside with a gas chamber gap.

With the implementation of this creation, at least the following advancements can be achieved:

First, the gas chamber gap can balance the pressure inside the gas chamber and outside the gas chamber, avoiding the situation that the internal pressure pushes the adhesive layer and causes the glue to overflow.

Second, the gas chamber gap can balance the pressure inside the gas chamber and outside the gas chamber, avoiding the problem that the internal pressure pushes the optical unit and causes the optical unit to tilt.

In order to enable any skilled artisan to understand the technical content of the present invention and implement it according to the contents of the present specification, the scope of the patent application and the drawings The objects and advantages of the present invention can be easily understood by those skilled in the art, and thus the detailed features and advantages of the present invention will be described in detail in the embodiments.

100‧‧‧Study image sensor

10‧‧‧ circuit board

11‧‧‧ bearing surface

12‧‧‧First conductive contacts

13‧‧‧Drive ICs and passive components

14‧‧‧ bottom

200‧‧‧Image sensor structure with air gap

20‧‧‧Image sensing wafer

21‧‧‧ first surface

22‧‧‧ second surface

23‧‧‧Sensing area

24‧‧‧Second conductive contacts

25‧‧‧Metal wire

26‧‧‧Adhesive layer

27‧‧‧Spherical support

28..‧‧‧ gas chamber gap

28’‧‧‧ gas chamber gap

29‧‧‧Adhesive

30‧‧‧ Optical unit

301‧‧‧Translucent plate

302‧‧‧Intermediate

303‧‧‧ Frame-shaped concave edge

304‧‧‧Depression

305‧‧‧ upper surface

31‧‧‧ air chamber

40‧‧‧Package

50‧‧‧Mold

60‧‧‧Filled rubber

FIG. 1A is a schematic diagram showing the structure of a conventional image sensor.

FIG. 1B is a schematic diagram showing the tilting of the optical unit and causing a crack in the manufacturing process of the conventional image sensor.

FIG. 1C is a schematic diagram showing the tilting of the optical unit and the overflow of the glue during the manufacturing process of the conventional image sensor.

2 is a cross-sectional view showing the structure of an image sensor having a cell gap in the present embodiment.

FIG. 3A is a top plan view of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention.

FIG. 3B is a top plan view 2 of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention.

FIG. 3C is a cross-sectional view showing the structure of an image sensor having a cell gap and an adhesive layer thereof according to an embodiment of the present invention.

4 is a top plan view 3 of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention.

Fig. 5A is a perspective view of an intermediate layer of the present embodiment.

FIG. 5B is a perspective view showing a combination of an intermediate layer and a light-transmitting plate according to the embodiment of the present invention.

FIG. 5C is a cross-sectional view showing another structure of an image sensor having a cell gap in the present embodiment.

Fig. 5D is a plan view of Fig. 5C.

FIG. 6A is a cross-sectional view showing the structure of a package of an image sensor having a gas cell gap according to an embodiment of the present invention.

FIG. 6B is a cross-sectional view 2 of the image sensor package with a gas cell gap according to an embodiment of the present invention.

2 is a cross-sectional view showing the structure of an image sensor having a cell gap in the present embodiment. FIG. 3A is a top plan view of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention. FIG. 3B is a top plan view 2 of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention. FIG. 3C is a cross-sectional view showing the structure of an image sensor having a cell gap and an adhesive layer thereof according to an embodiment of the present invention.

4 is a top plan view 3 of an image sensor having a gas cell gap and an adhesive layer thereof according to an embodiment of the present invention. Fig. 5A is a perspective view of an intermediate layer of the present embodiment. FIG. 5B is a perspective view showing a combination of an intermediate layer and a light-transmitting plate according to the embodiment of the present invention. FIG. 5C is a cross-sectional view showing another structure of an image sensor having a cell gap in the present embodiment. Fig. 5D is a plan view of Fig. 5C. FIG. 6A is a cross-sectional view showing the structure of a package of an image sensor having a gas cell gap according to an embodiment of the present invention. FIG. 6B is a cross-sectional view 2 of the image sensor package with a gas cell gap according to an embodiment of the present invention.

As shown in FIG. 2 and FIG. 3A , the present embodiment is an image sensor structure 200 having a gas cell gap, comprising: a circuit substrate 10 , an image sensing chip 20 , an adhesive layer 26 , and a Optical unit 30.

The circuit substrate 10 has a bearing surface 11 and a bottom surface 14. A plurality of first conductive contacts 12 are disposed on the bearing surface 11 for electrical connection during wire bonding. In addition, the driving IC and the passive component 13 are selectively disposed on the carrying surface 11, and the driving IC and the passive component 13 are electrically connected to the circuit on the carrying surface 11.

The image sensing chip 20 can be a complementary CMOS image sense A wafer or a charge coupled device. The image sensing wafer 20 has a first surface 21, a second surface 22, and a plurality of second conductive contacts 24.

The first surface 21 is a lower surface of the image sensing wafer 20 , and is coupled to the bearing surface 11 through a glue to bond the image sensing wafer 20 to the circuit substrate 10 . The second surface 22 is the upper surface of the image sensing wafer 20, and the second surface 22 has a sensing region 23 for receiving and sensing light. In addition, a plurality of second conductive contacts 24 are disposed on the outer side of the sensing region 23 on the second surface 22, and can be electrically connected to the first conductive contacts 12 on the carrying surface 11 by the metal wires 25, respectively. Therefore, the image sensing chip 20 can be electrically connected to the driving IC and the passive component 13 through the circuit on the carrying surface 11 .

The adhesive layer 26 is disposed on the second surface 22 around the sensing region 23. For example, the adhesive layer 26 can be disposed between the sensing region 23 and the second conductive contacts 24 to sense the package. The region 23 can be accommodated in the space formed by the adhesive layer 26 and the optical unit 30, thereby preventing the sensing region 23 from being externally attacked. At the same time, the adhesive layer 26 does not cover the sensing area 23 during coating, thereby avoiding affecting the sensing area 23 to receive and sense light. The adhesive layer 26 can be a photocurable adhesive layer, and can be an ultraviolet (UltraViolet, UV) photocurable adhesive layer. Therefore, the adhesive layer 26 exhibits a gel state before it is cured by ultraviolet light.

The optical unit 30 can be a light transmissive plate made of a glass. The optical unit 30 is adhered to the second surface 22 through the adhesive layer 26, and the optical unit 30 is fixed by curing the adhesive layer 26, and an air chamber 31 is formed between the adhesive layer 26, the image sensing wafer 20 and the optical unit 30. The gas chamber 31 has a gas chamber notch 28 communicating with the outside to balance the pressure in the gas chamber 31 and outside the gas chamber 31. As a result, when the adhesive layer 26 is cured, the gas in the gas chamber 31 expanded by heating will be dissipated from the gas chamber notch 28 to the outside of the gas chamber 31, thereby avoiding the excessive gas internal pressure pushing the optical unit 30. The tilting problem of the optical unit 30 or the excessive gas internal pressure pushes the overflow of the adhesive layer 26.

The above-described gas chamber notch 28 can be formed in the following manner. For example, the adhesive layer 26 may have a C-shaped structure, and the opening of the C-shaped structure overlaps between the optical unit 30 over the adhesive layer 26 and the image sensing wafer 20 under the adhesive layer 26. The air chamber notch 28 is formed.

As shown in FIG. 3B, the adhesive layer 26 may also have two L-shaped structures disposed opposite to each other, and the two L-shaped structures are respectively located at opposite diagonals to form two openings respectively on the other two diagonals, and the openings The image sensing wafer 20 under the opening and adhesive layer 26 and the optical unit 30 overlying the adhesive layer 26 constitute the gas cell gaps 28.

As shown in FIG. 3C, since the adhesive layer 26 is gel-like before uncured, it is easy to cause the optical unit 30 disposed thereon to be excessively inclined due to the inconsistent amount or height applied during coating, which affects the image feeling. The quality of the test. Therefore, the adhesive layer 26 can be further provided with a plurality of ball spacers 27, which can maintain the optical unit 30 and the image sensing wafer 20 at an optimum spacing to control the tilt of the optical unit 30. Degree is within reasonable limits.

As shown in FIGS. 3C to 5B, in the case where the spherical support member 27 is not added to the adhesive layer 26, in order to maintain the optical unit 30 and the image sensing wafer 20 at an optimum spacing, the tilt of the optical unit 30 is controlled. Degree is within reasonable limits. The optical unit 30 can include an intermediate layer 302 and a light transmissive plate 301. The intermediate layer 302 of the fixed height controls the spacing between the light transmissive plate 301 and the image sensing wafer 20. At this point, the adhesive layer 26 can assume a closed loop structure that allows the adhesive layer 26 to hermetically adhere the optical unit 30 to the second surface 22.

The intermediate layer 302 is a monogram structure. When the intermediate layer 302 is associated with the adhesive layer 26 and adhered to the adhesive layer 26, the sensing region 23 may not be covered. In addition, a frame-shaped concave edge 303 may be formed inside the upper surface 305 of the intermediate layer 302 so that the light-transmitting plate 301 can be adhered to the frame-shaped concave edge 303 to be combined with the intermediate layer 302. The material of the intermediate layer 302 may be a glass, a ceramic, a liquid crystal polymer, a molding compound, a decyloxyalkyl polymer, a photosensitive dry film or a solder mask.

As shown in FIG. 5A to FIG. 5D, the inner side of the intermediate layer 302 may have a recessed portion 304, such that when the light-transmitting plate 301 is combined with the intermediate layer 302, for example, when the light-transmitting plate 301 is adhered to the frame-shaped concave edge 303, The airtight gap 28' is formed between the light-transmitting plate 301 and the recessed portion 304 because it cannot be completely hermetically bonded. The air chamber notch 28' communicates with the air in the air chamber 31 and outside the air chamber 31, so that the pressure in the air chamber 31 is greater than the external pressure. The force affects the adhesion stability of the optical unit 30.

As shown in FIG. 5C to FIG. 6A, an image sensor structure 200 having a gas cell gap in the present embodiment further includes a filling material 60 disposed in the gas chamber notch 28/28' to be closed. The gas chamber gap 28/28' forms a closed space for the gas chamber 31 to prevent the sensing area 23 from being externally attacked.

As shown in FIG. 6A, the image sensor structure 200 having a gas cell gap further includes an encapsulant 40 that can be coated on the circuit substrate 10 by a moding packaging process or a dispensing technique. The image sensing wafer 20, the adhesive layer 26, the filling material 60, and the side of the optical unit 30. In more detail, the side of the optical unit 30 and the side of the optical unit 30, the side of the circuit board 10 and the circuit board 10, and the closed circuit pattern, the C-shaped pattern or the double L-shaped pattern can be adhered by the encapsulant 40. The space between the outer layers of layer 26 is sealed. Thereby, the side edges of the circuit substrate 10 can be covered by the encapsulant 40 to prevent the side edges of the circuit substrate 10 from being damaged by impact.

As shown in FIG. 6B, the image sensor structure 200 having a gas cell gap further includes a package adhesive 40 which can be disposed on the circuit substrate 10 through a molding process or a dispensing technique. And covering the image sensing wafer 20, the adhesive layer 26, the filling material 60 and the side of the optical unit 30. In more detail, the side of the optical unit 30 and the lower side of the optical unit 30, but not the side of the circuit substrate 10, and the closed circuit pattern, the C-shaped pattern or the double L-shaped pattern can be formed by the encapsulant 40. The space between the outer periphery of the adhesive layer 26 is sealed.

The image sensor structure with a gas chamber gap in the embodiment of the present invention can balance the pressure in the gas chamber and the gas chamber by the gas chamber gap, and avoid the excessive gas internal pressure pushing the optical unit to cause the optical unit to tilt or push the adhesive layer. Causes spillage. In addition, the inclination of the optical unit can be controlled within a reasonable range by the arrangement of the spherical support or the intermediate layer.

However, the above embodiments are intended to illustrate the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the contents of the present invention and to implement it, and not to limit the scope of the patent of the present invention. Complete the spirit of revealing Equivalent modifications or modifications are still included in the scope of the patent application described below.

200‧‧‧Image sensor structure with air gap

10‧‧‧ circuit board

11‧‧‧ riding surface

12‧‧‧First conductive contacts

13‧‧‧Drive ICs and passive components

14‧‧‧ bottom

20‧‧‧Image sensing wafer

21‧‧‧ first surface

23‧‧‧Sensing area

24‧‧‧Second conductive contacts

25‧‧‧Metal wire

26‧‧‧Adhesive layer

30‧‧‧ Optical unit

31‧‧‧ air chamber

Claims (15)

An image sensor structure having a gas chamber gap, comprising: a circuit substrate having a bearing surface and a bottom surface, wherein the bearing surface is provided with a plurality of first conductive contacts; and an image sensing wafer having a first surface is coupled to the bearing surface; a second surface having a sensing region; and a plurality of second conductive contacts disposed on an outer side of the sensing region, and the second conductive portions The contacts are electrically connected to the first conductive contacts by a plurality of metal wires; an adhesive layer is disposed on the second surface between the sensing region and the second conductive contacts and The sensing area is not covered; and an optical unit is adhered to the second surface through the adhesive layer, and a gas chamber is formed between the image sensing wafer and the optical unit, and the air chamber has a gas chamber gap Connected with the outside world. The image sensor structure of claim 1, further comprising a filling material disposed in the gas chamber gap to close the gas chamber gap. The image sensor structure of claim 2, further comprising a package material disposed on the circuit substrate and covering the image sensing wafer, the adhesive layer, and the optical unit Side of it. The image sensor structure of claim 2, further comprising a package adhesive covering the circuit substrate, the image sensing wafer, the adhesive layer and the side of the optical unit. The image sensor structure of claim 1, wherein the image sensing chip is a complementary MOS image sensing chip or a charge coupled device. The image sensor structure of claim 1, wherein the adhesive layer is in a closed loop pattern structure, and the optical unit comprises: an intermediate layer having a mouth-shaped structure corresponding to the adhesive layer Adhering to the adhesive layer, a mask-shaped concave edge is formed on the inner surface of the upper surface of the intermediate layer, and the intermediate layer has a concave portion; and a light-transmitting plate is adhesively disposed on the frame-shaped concave edge. When the light-transmitting plate is combined with the intermediate layer, the light-transmitting plate and the concave portion constitute the gas chamber gap. The image sensor structure of claim 6, wherein the material of the intermediate layer is a glass, a ceramic, a liquid crystal polymer, a molding compound, a methoxyalkyl polymer, and a photosensitive property. Dry film or a solder mask. The image sensor structure of claim 1, wherein the adhesive layer has a C-shaped structure, and the opening of the C-shaped structure and the image sensing wafer and the optical unit form the gas cell gap. The image sensor structure of claim 1, wherein the adhesive layer is formed in two L-shaped structures opposite to each other to form two openings on the diagonal, and the openings and the image sensing wafer And the optical unit constitutes the gas chamber gaps. The image sensor structure of any one of clauses 6 to 9, further comprising a filling material disposed in the gas chamber gap to close the gas chamber gap. The image sensor structure of claim 10, further comprising a package material disposed on the circuit substrate and covering the image sensing wafer, the adhesive layer, and the optical unit Side of it. The image sensor structure of claim 10, further comprising a package material coated on the circuit substrate, the image sensing chip, the Adhesive layer and the side of the optical unit. The image sensor structure of claim 8 or claim 9, wherein the adhesive layer is further provided with a plurality of spherical supports. The image sensor structure of claim 13, wherein the optical unit is a light transmissive plate made of a glass. The image sensor structure of claim 14, wherein the adhesive layer is a photocurable adhesive layer.