Internal sealing device of flip driving IC (integrated circuit) chip and display screen

Abstract

The utility model relates to an internal sealing device of a flip drive IC chip and a display screen, the internal sealing device comprises a substrate, the drive IC chip and an LED chip, the drive IC chip is welded on the front surface of the substrate through flip structure solder paste, and the LED chip is installed on the front surface of the substrate and is electrically connected with the drive IC chip; the driving IC chip, the LED chip and the substrate are packaged into a whole through LED packaging glue; at least four spherical bonding pads are arranged on the back surface of the substrate according to a row-column structure; the first spherical bonding pad, the second spherical bonding pad, the third spherical bonding pad and the fourth spherical bonding pad form four vertexes of a rectangle on the back surface of the substrate, and the first spherical bonding pad and the second spherical bonding pad are diagonally arranged. According to the utility model, the size of the device can be reduced, the traditional wire welding process is saved, and the reliability is improved.

Description

Technical Field

[0001] The utility model relates to the field of LED devices, in particular to an inner encapsulation device and a display screen of a flip-chip driving IC chip. Background Art

[0002] With the rapid development of the chip industry, there are more and more types of chips. A major branch of LED chips is used for display screens. People's main requirements for LED chips are small area, low power consumption, high luminous brightness, and long service life. However, traditional packaging processes cannot meet these requirements. Traditional LED devices use individual packaging of LED chips, and then an external driving IC chip is used to drive the LED chips to work. In this packaging method, the external driving IC chip is easily affected by the external environment, resulting in problems such as failure of the entire LED device, thereby shortening the service life of the LED device. Therefore, the method of integrating the driving IC chip is adopted to solve these problems. The existing LED devices with built-in driving IC chips encapsulate the driving IC chip in the LED device and connect the driving IC chip and the LED chip by means of internal wire bonding. However, the wire bonds are prone to breakage. The method of internal wire bonding will result in a low yield rate and low production efficiency of the LED device. Moreover, due to the existence of wire bonds, the wire bond layout of the chip is increased, thereby increasing the area. Summary of the Invention

[0003] In view of the existing deficiencies, the utility model provides an inner encapsulation device and a display screen of a flip-chip driving IC chip.

[0004] The technical solution adopted by the utility model to solve its technical problems is: an inner encapsulation device of a flip-chip driving IC chip, including a substrate, a driving IC chip, and an LED chip. The driving IC chip and the LED chip are both soldered to the front surface of the substrate in a flip-chip structure with solder paste, and the LED chip is electrically connected to the driving IC chip; the driving IC chip, the LED chip, and the substrate are encapsulated into one body by an LED encapsulation glue; at least four solder pads are arranged on the back surface of the substrate in a row-column structure. The four solder pads are respectively a first spherical solder pad connected to the power supply pin of the driving IC chip, a second spherical solder pad connected to the ground pin of the driving IC chip, a third spherical solder pad connected to the input pin of the driving IC chip, and a fourth spherical solder pad connected to the output pin of the driving IC chip; the first spherical solder pad, the second spherical solder pad, the third spherical solder pad, and the fourth spherical solder pad form the four vertices of a rectangle on the back surface of the substrate, and the first spherical solder pad and the second spherical solder pad are diagonally arranged.

[0005] Preferably, the LED chip includes a red LED chip, a green LED chip, and a blue LED chip, and the red LED chip, the green LED chip, and the blue LED chip are connected in parallel to the driving IC chip.

[0006] Preferably, a Zener diode and / or a capacitor connected between a power pin and a ground pin of the driving IC chip are further built in the front surface of the substrate.

[0007] Preferably, a groove for mounting the capacitor and the Zener diode is recessed in the front surface of the substrate, and the surfaces of the Zener diode and / or the capacitor are covered with a white reflective adhesive layer.

[0008] A display screen adopts the inner-sealing device of the flip-chip driving IC chip as described in any one of the foregoing.

[0009] The beneficial effects of the present utility model are as follows: The utility model integrates and packages the driving IC chip and the LED chip together, with a simple structure, reducing the production cost. At the same time, they are both in a flip-chip structure and soldered to the front surface of the substrate by means of solder paste, eliminating the need to set up bonding wires on the substrate for electrical connection, simplifying the structural arrangement. Each spherical solder pad and the driving IC chip and the LED chip are on opposite sides of the substrate, enabling all the electronic components of the LED device to be built in, further simplifying the electrical connection structure between the electronic components of the LED device, improving the product yield and production efficiency, and also meeting the miniaturization requirements of the LED device; during use, the positions of the solder pads facilitate the connection between multiple devices, and the electronic components are no longer affected by the external environment, improving the reliability. While reducing the cost, the performance of the product is also enhanced. Description of the Drawings

[0010] Figure 1 is a schematic cross-sectional structure view of the first embodiment of the present utility model along the driving IC chip;

[0011] Figure 2 is a schematic structure view of the back surface of the first embodiment of the present utility model;

[0012] Figure 3 is a schematic structure view of the front surface of the first embodiment of the present utility model;

[0013] Figure 4 is a schematic cross-sectional structure view of the first embodiment of the present utility model along the capacitor

[0014] Figure 5 is a schematic structure view of the first embodiment of the present utility model in which multiple devices are connected to form an LED module;

[0015] Figure 6 is a schematic structure view of the back surface of the second embodiment of the present utility model;

[0016] Names and serial numbers of components in the figure: 1 - Substrate, 10 - Groove, 11 - White reflective adhesive layer, 2 - Driving IC chip, 3 - LED chip, 30 - Red LED chip, 31 - Green LED chip, 32 - Blue LED chip, 4 - First ball grid array pad, 5 - Second ball grid array pad, 6 - Third ball grid array pad, 7 - Fourth ball grid array pad, 8 - Zener diode, 9 - Capacitor. Detailed implementation

[0017] The following will further illustrate the present utility model in conjunction with embodiments. A clear and complete description should be understood. These embodiments are used to illustrate the present utility model but not to limit its scope. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers. The implementation conditions not specified are usually those in conventional experiments. In addition, the directional terms mentioned in the present utility model, such as "up", "down", "front", "rear", "left", "right", "inside", "outside", etc., are only references to the directions in the attached drawings. The directional terms used are for better and clearer illustration and understanding of the present utility model, rather than indicating or implying the azimuth that the present utility model must have. Therefore, it cannot be understood as a limitation to the present utility model.

[0018] As shown in the embodiments of the present utility model Figures 1 to 6 shown in, an internal encapsulation device for a flip-chip driving IC chip includes a substrate 1, a driving IC chip 2, and an LED chip 3. The driving IC chip 2 and the LED chip 3 are both soldered to the front side of the substrate in a flip-chip structure using solder paste, that is, both the driving IC chip 2 and the LED chip 3 are flip-chip and soldered to the front side of the substrate by means of solder paste printing, as Figure 3 shown in. The LED chip 3 includes a red LED chip 30, a green LED chip 31, and a blue LED chip 32. The red LED chip 30, the green LED chip 31, and the blue LED chip 32 are connected in parallel to the driving IC chip 2. During production, first, solder paste is printed on the substrate 1 by means of solder paste printing, then the driving IC chip 2 and the LED chip 3 are die-bonded to the substrate 1, and then they are soldered to the substrate 1 through reflow soldering. At this time, the LED chip 3 is electrically connected to the driving IC chip 2. By adopting a flip-chip structure and solder paste soldering, it is no longer necessary to use bonding wires to connect them, thus solving the problem that bonding wires are easily broken, improving the yield of LED devices, saving the steps of bonding wires. Without the bonding wires on the substrate 1, the structure is simplified, enabling the substrate 1 to be miniaturized, and also facilitating the heat dissipation of the chips. After the LED chip 3 and the driving IC chip 2 are soldered to the substrate 1, the driving IC chip 2, the LED chip 3, and the substrate 1 are encapsulated into an integrated structure using LED encapsulation glue, forming an LED device with built-in electronic components, which facilitates its installation and use. The built-in structure solves the problem of failure caused by the influence of the external environment, and improves the service life of the LED device; asFigure 2 , Figure 5 and Figure 6 As shown in Figure 6 , at least four pads are arranged on the back surface of the substrate 1 in a row-column structure. The four pads are respectively a first ball pad 4 connected to the power pin of the driving IC chip 2, a second ball pad 5 connected to the ground pin of the driving IC chip 2, a third ball pad 6 connected to the input pin of the driving IC chip 2, and a fourth ball pad 7 connected to the output pin of the driving IC chip 2. When they are used for soldering connection, the pads have a larger contact surface, a larger routing space between the pads, and less stress concentration at the solder joints, which increases the reliability of the solder joints and improves the soldering yield rate. The first ball pad 4, the second ball pad 5, the third ball pad 6, and the fourth ball pad 7 form the four vertices of a rectangle on the back surface of the substrate 1, and the first ball pad 4 and the second ball pad 5 are diagonally arranged. That is, when the first ball pad 4 is located in the upper left corner of the back surface of the substrate 1, the second ball pad 5 is located in the lower right corner of the back surface of the substrate 1. At the same time, the third ball pad 6 is located in the upper right corner of the back surface of the substrate 1, and the fourth ball pad 7 is located in the lower left corner of the back surface of the substrate 1. This facilitates the layout of the connecting wires between the devices when multiple devices are assembled into an LED module and is more conducive to use.

[0019] For further improvement, as Figure 3 and Figure 4 shown, a Zener diode 8 and / or a capacitor 9 connected between the power pin and the ground pin of the driving IC chip 2 are also built in on the front surface of the substrate 1. That is, according to the usage requirements, the Zener diode 8 or the capacitor 9 is encapsulated into an integrated structure with the driving IC chip 2 and the LED chip 3 on the front surface of the substrate 1, or the Zener diode 8 and the capacitor 9 are simultaneously encapsulated into an integrated structure with the driving IC chip 2 and the LED chip 3 on the front surface of the substrate 1. The Zener diode 8 is used to keep the voltage passing through the chip stable and increase the electrostatic resistance of the device. The capacitor 9 is a surface mount capacitor, and the capacitor 9 is used to achieve stable display. For the arrangement structure of the Zener diode 8 and the capacitor 9 on the front surface of the substrate 1, a groove 10 for installing the capacitor 9 and the Zener diode 8 is recessed on the front surface of the substrate 1. Installing the Zener diode 8 and the capacitor 9 in the groove 10 makes them not protrude from the surface of the substrate 1, so that they will not block the light emitted by the LED chip and facilitate the emission of light. At this time, a white reflective glue layer 11 is covered on the surface of the Zener diode 8 and / or the capacitor 9. After the Zener diode 8 and the capacitor 9 are installed in the groove 10, white reflective glue is poured into the groove, and the white reflective glue wraps the Zener diode 8 and the capacitor 9 to form the white reflective glue layer 11. Through the reflection of the white reflective glue layer 11, the absorption of the light emitted by the LED chip 3 by the Zener diode 8 and the capacitor 9 can be effectively reduced, increasing the light output, improving the light extraction efficiency, and reducing the energy consumption.

[0020] A display screen adopts an inner-sealed device of the flip-chip driving IC chip described in any one of the foregoing, arranges the foregoing multiple devices in a structure of one column or one row, and then connects the multiple devices in a manner that the fourth ball pad 7 of the previous device is connected to the third ball pad 6 of the next device to form an LED module. Then, multiple LED modules are used to form a display screen. At the same time, the first ball pads 4 of the multiple devices are all connected to one connection line, and the second ball pads 5 are all connected to another connection line.

[0021] Although the present utility model has been described in detail with general descriptions and specific embodiments above, based on the present utility model, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present utility model all fall within the scope of protection required by the present utility model.

Claims

1. An internal packaging device for an inverted drive IC chip, characterized in that: It includes a substrate, a driving IC chip and an LED chip. The driving IC chip and the LED chip are both soldered to the front of the substrate in a flip-chip structure with solder paste, and the LED chip is electrically connected to the driving IC chip; the driving IC chip, the LED chip and the substrate are encapsulated into one body by an LED encapsulation glue; at least four pads are arranged on the back of the substrate in a row-column structure, and the four pads are respectively a first ball-shaped pad connected to the power pin of the driving IC chip, a second ball-shaped pad connected to the ground pin of the driving IC chip, a third ball-shaped pad connected to the input pin of the driving IC chip, and a fourth ball-shaped pad connected to the output pin of the driving IC chip; the first ball-shaped pad, the second ball-shaped pad, the third ball-shaped pad and the fourth ball-shaped pad form the four vertices of a rectangle on the back of the substrate, and the first ball-shaped pad and the second ball-shaped pad are arranged diagonally.

2. The internal packaging device of the flip-chip driving IC chip according to claim 1, characterized in that : The LED chip includes a red LED chip, a green LED chip and a blue LED chip, and the red LED chip, the green LED chip and the blue LED chip are connected in parallel to the driving IC chip.

3. The internal encapsulation device of the flip-chip driving IC chip according to claim 1, characterized in that : A Zener diode and / or a capacitor connected between the power pin and the ground pin of the driving IC chip are also built in the front of the substrate.

4. The inner package device of the flip-chip driving IC chip according to claim 3, characterized in that : A groove for installing the capacitor and the Zener diode is recessed on the front of the substrate, and the surface of the Zener diode and / or the capacitor is covered with a white reflective glue layer.

5. A display screen, characterized in that: An inner-sealed device using the flip-chip driving IC chip according to any one of claims 1 to 4.

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