A novel image sensor packaging structure and packaging method

Abstract

The present invention relates to the field of chip packaging technology, and in particular to a novel image sensor packaging structure and packaging method, including a substrate, a cavity for installing a chip is opened on the upper surface of the substrate, the chip is installed inside the cavity by patch glue, and a plurality of solder balls are fixed on the lower surface of the substrate by back pin pads. A novel image sensor packaging structure and packaging method of the present invention forms a cavity by digging grooves on the substrate, and the chip is placed in the cavity. The glue dispensing area of ​​the cover light-transmitting plate is increased by borrowing the substrate area, so that some chips with a small distance from the photosensitive area to the chip edge can also be made into iBGA packaging, which can adapt to a wider range of customer needs; the encapsulation material encapsulates the metal wires and the sensor chip on all sides, which can effectively block foreign matter such as water vapor and environmental particles from entering the cavity to affect the chip operation, and also protect the metal wires from oxidation corrosion, thereby improving reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and in particular to a novel image sensor packaging structure and packaging method. Background Art

[0002] The existing iBGA image sensor packaging method in the industry is to attach the sensor chip to the surface of the substrate to complete the packaging. The disadvantages of this method are: there are strict requirements on the distance from the chip's photosensitive area to the chip edge. If the distance is too small, there is no glue dispensing position or the glue dispensing position is insufficient, and there is a risk that the glue will be harmful to the photosensitive area. As a result, many image chips cannot be packaged in iBGA and can only be packaged in PLGA and CLGA. PLGA packaging is commonly used in consumer electronics and is large in size. The reliability level is low and cannot meet the requirements of automotive regulations. CLGA packaging is large in size and expensive. Summary of the invention

[0003] The technical problems to be solved by the present invention are: a method to solve the problem that the distance between the photosensitive area of ​​the optical chip and the edge of the chip is too small and it cannot be made into an iBGA package; meet the current automotive-grade requirements and achieve high-reliability packaging of image sensors; and a packaging method to achieve this packaging structure.

[0004] The technical solution adopted by the present invention to solve its technical problem is: a new image sensor packaging structure, including a substrate, a chip is installed in the cavity of the substrate, front gold fingers are fixed on both sides of the chip on the substrate, an external protective device is installed on the upper surface of the substrate covering the upper ends of the chip and the front gold fingers, and a plurality of solder balls are fixed on the lower surface of the substrate through the back pin pads.

[0005] The upper surface of the substrate is provided with a cavity for mounting a chip, the chip is mounted inside the cavity by patch adhesive, the front gold fingers are fixedly mounted on the upper surface of the substrate, located on both sides of the cavity, the upper surface of the chip is fixed with chip pin pads on both sides of the photosensitive area, and the front gold fingers are connected to the chip pin pads by metal wires;

[0006] The external protection device comprises a light-transmitting plate fixed at the opening position of the upper end of the cavity by DAM glue and an encapsulating glue located outside the light-transmitting plate.

[0007] The substrate is made of resin material, glass, ceramic, or silicon material. Considering the cost, resin is preferred.

[0008] The size of the cavity is larger than the chip size, and the groove depth of the cavity and the thickness of the chip match each other.

[0009] A safe distance is left between the photosensitive area on the upper surface of the chip and the DAM glue.

[0010] The encapsulation glue gradually extends from the connecting surface of the light-transmitting plate to the outer side surface of the substrate.

[0011] The metal wire can be a gold wire, a copper wire, or an alloy wire.

[0012] The light-transmitting plate can be glass, acrylic, PC board, or PVC transparent board.

[0013] An external protective frame is mounted on the outer side of the substrate to reduce the warping of the substrate.

[0014] A novel image sensor packaging method is characterized in that: a cavity is formed in a patch area of ​​a substrate for installing a chip, glue is dispensed in the cavity, the amount of glue is controlled, the chip is mounted in the cavity, the patch glue fills the gap between the chip and the substrate, the upper surface of the chip is flush with the upper surface of the substrate, and the glue is cured to firmly bond the chip and the substrate; the metal wire is connected to the chip pin pad on the chip and the front gold finger on the substrate through lead welding, so as to achieve electrical conduction, DAM glue is dispensed in the connection area between the chip and the upper surface of the substrate, the glue thickness and width are controlled, and a safe distance is maintained from the photosensitive area to prevent the glue from overflowing into the photosensitive area, a patch device is used to place a light-transmitting plate on the DAM glue, and it is firmly bonded through UV irradiation and oven baking, and liquid black glue is used for pouring and encapsulation to wrap the light-transmitting plate, the DAM glue, and the metal wire, and the encapsulation glue extends to the outer side of the substrate, and finally a solder ball is planted on the back pin pad to make an iBGA package.

[0015] The beneficial effects of the present invention are:

[0016] (1) A novel image sensor packaging structure and packaging method of the present invention forms a cavity by digging a groove on a substrate, placing the chip in the cavity groove, and increasing the glue dispensing area of ​​the cover transparent plate by using the substrate area, so that some chips with a small distance from the photosensitive area to the chip edge can also be made into iBGA packaging, adapting to a wider range of customer needs;

[0017] (2) The encapsulation material encapsulates the metal wires and sensor chip on all sides, which can effectively block foreign matter such as water vapor and environmental particles from entering the cavity and affecting the chip operation. It also protects the metal wires from oxidation and corrosion, thereby improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of the cavity in the present invention.

[0021] Figure 3 It is a schematic diagram of the chip assembly state in the present invention.

[0022] Figure 4 It is a schematic diagram of the structure after the metal wire is installed in the present invention.

[0023] Figure 5 It is a schematic diagram of the structure after the DAM glue in the present invention is installed.

[0024] Figure 6 It is a schematic diagram of the structure after the light-transmitting plate in the present invention is installed.

[0025] Figure 7 It is a schematic diagram of the structure after the encapsulation glue is installed in the present invention.

[0026] Figure 8 It is a schematic structural diagram of the second embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] Figure 1 to Figure 7 A novel image sensor packaging structure shown in the figure includes a substrate 1, a chip 2 is installed in the cavity of the substrate 1, front gold fingers 7 are fixed on both sides of the chip on the substrate 1, an external protective device is installed on the upper surface of the substrate 1, and a plurality of solder balls 6 are fixed on the lower surface of the substrate 1 through the back pin pads 5.

[0030] A cavity 3 for mounting a chip 2 is provided on the upper surface of the substrate 1. The chip 2 is mounted inside the cavity 3 by a patch adhesive 4. A front gold finger 7 is fixedly mounted on the upper surface of the substrate 1 and located on both sides of the cavity 3. Chip pin pads 9 are fixed on the upper surface of the chip 2 and located on both sides of the photosensitive area 8. The front gold finger 7 is connected to the chip pin pad 9 by a metal wire 10.

[0031] The external protection device includes a light-transmitting plate 12 fixed at the upper opening of the cavity 3 by DAM glue 11 and an encapsulating glue 13 located outside the light-transmitting plate 12 .

[0032] The substrate 1 is made of resin, glass, ceramic or silicon. Considering the cost, resin is preferred. The size of the cavity 3 is larger than that of the chip 2 , and the groove depth of the cavity 3 and the thickness of the chip 2 match each other.

[0033] A safe distance is left between the photosensitive area 8 on the upper surface of the chip 2 and the DAM glue 11; the encapsulation glue 13 gradually extends from the connection surface of the light-transmitting plate 12 to the outer side surface of the substrate.

[0034] The metal wire 10 can be a gold wire, a copper wire, or an alloy wire; the light-transmitting plate 12 can be glass, acrylic, a PC board, or a PVC transparent board.

[0035] like Figure 8 As shown, in Embodiment 2, an outer protective frame 14 for reducing the warping of the substrate 1 is mounted on the outer side of the substrate 1 . The material of the outer protective frame 14 is the same as that of the substrate 1 , and the amount of the encapsulating glue 13 can be reduced.

[0036] A bottom card slot of a U-shaped structure is provided at the outer edge of the lower end of the substrate 1 to facilitate fixing the external protection frame 14, so as to facilitate fixing and assembling the external protection frame 14. The upper end of the external protection frame 14 protrudes upward, which can facilitate the outer side limitation of the encapsulation glue 13 and reduce the amount used.

[0037] A new image sensor packaging method, such as Figure 2 As shown, a cavity is formed in the patch area of ​​the substrate 1 to install the chip 2; Figure 3 As shown, glue is dispensed in the cavity 3, the glue amount is controlled, and the chip 2 is mounted in the cavity 3. The gap between the chip 2 and the substrate 1 is filled with the patch glue, so that the upper surface of the chip 2 is flush with the upper surface of the substrate 1, and the glue is cured to make the chip 2 and the substrate 1 firmly bonded; Figure 4 As shown, the metal wire 10 is connected to the chip pin pad 9 on the chip 2 and the front gold finger 7 on the substrate 1 by wire welding, so as to achieve electrical conduction; Figure 5 As shown, DAM glue 11 is applied to the connection area between the chip 2 and the upper surface of the substrate 1, and the glue thickness and width are controlled to keep a safe distance from the photosensitive area 8 to prevent the glue from overflowing to the photosensitive area 8; Figure 6 As shown, a patch device is used to place the light-transmitting plate 12 on the DAM glue 11, and it is firmly bonded by UV irradiation and oven baking; Figure 7 As shown, liquid black glue is used for encapsulation, and the transparent plate 12, DAM glue 11, and metal wire 10 are wrapped. The encapsulation glue 13 extends to the outer side of the substrate 1, and finally the solder ball 6 is planted on the back pin pad 5 to make an iBGA package, such as Figure 1 shown.

[0038] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A novel image sensor packaging structure, comprising a substrate (1), characterized in that: A chip (2) is installed in the cavity of the substrate (1); front gold fingers (7) are fixed on both sides of the chip on the substrate (1); an external protective device is installed on the upper surface of the substrate (1) covering the upper ends of the chip (2) and the front gold fingers (7); and a plurality of solder balls (6) are fixed on the lower surface of the substrate (1) via back pin pads (5); The upper surface of the substrate (1) is provided with a cavity (3) for mounting a chip (2); the chip (2) is mounted inside the cavity (3) via a patch adhesive (4); the front gold fingers (7) are fixedly mounted on the upper surface of the substrate (1) and are located on both sides of the cavity (3); the upper surface of the chip (2) is fixed with chip pin pads (9) located on both sides of the photosensitive area (8); the front gold fingers (7) and the chip pin pads (9) are connected via metal wires (10); The external protection device comprises a light-transmitting plate (12) fixed at the upper opening position of the cavity (3) by means of DAM glue (11) and an encapsulating glue (13) located outside the light-transmitting plate (12).

2. The novel image sensor packaging structure according to claim 1 is characterized in that: The substrate (1) is made of resin material, glass, ceramic, or silicon material. Considering the cost, resin is preferred.

3. The novel image sensor packaging structure according to claim 1 is characterized in that: The size of the cavity (3) is larger than the size of the chip, and the groove depth of the cavity (3) and the thickness of the chip (2) match each other.

4. The novel image sensor packaging structure according to claim 1 is characterized in that: A safe distance is left between the photosensitive area (8) on the upper surface of the chip (2) and the DAM glue (11).

5. The novel image sensor packaging structure according to claim 1 is characterized in that: The encapsulating glue (13) gradually extends from the connecting surface of the light-transmitting plate (12) to the outer side surface of the substrate.

6. The novel image sensor packaging structure according to claim 1 is characterized in that: The metal wire (10) may be a gold wire, a copper wire, or an alloy wire.

7. The novel image sensor packaging structure according to claim 1 is characterized in that: The light-transmitting plate (12) can be glass, acrylic, PC board, or PVC transparent board.

8. The novel image sensor packaging structure according to claim 1 is characterized in that: An external protective frame (14) is mounted on the outside of the substrate (1) to reduce the warping of the substrate (1).

9. A novel image sensor packaging method, characterized in that: A cavity is formed by slotting the patch area of ​​the substrate (1) to install the chip (2), and glue is dispensed in the cavity (3) to control the amount of glue. The chip (2) is mounted in the cavity (3), and the patch glue fills the gap between the chip (2) and the substrate (1) so that the upper surface of the chip (2) and the upper surface of the substrate (1) are flush. The glue is cured to firmly bond the chip (2) and the substrate (1); a metal wire (10) is connected to the chip pin pad (9) on the chip (2) and the front gold finger (7) on the substrate (1) through lead welding, thereby achieving electrical conduction, and the chip (2) is connected to the front gold finger (7) on the substrate (1). DAM glue (11) is applied to the area connected to the upper surface of the substrate (1), and the thickness and width of the glue are controlled. A safe distance is maintained from the photosensitive area (8) to prevent the glue from overflowing to the photosensitive area (8). A patch device is used to place the light-transmitting plate (12) on the DAM glue (11), and the light-transmitting plate (12), the DAM glue (11), and the metal wire (10) are firmly bonded by UV irradiation and oven baking. Liquid black glue is used for injection encapsulation to wrap the light-transmitting plate (12), the DAM glue (11), and the metal wire (10). The encapsulation glue (13) is extended to the outer side of the substrate (1), and finally a solder ball (6) is planted on the back pin pad (5) to make an iBGA package.

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