An LED device with a built-in driving chip and a manufacturing method thereof

Abstract

The application relates to an LED device with a built-in driving chip and a preparation method thereof and an LED display module, wherein the LED device with the built-in driving chip comprises a first substrate (11) and a second substrate (12) which are stacked in a thickness direction, a light-emitting unit (20) arranged on the second substrate (12), and a driving chip (30) arranged on the first substrate (11); the driving chip (30) is electrically connected with the light-emitting unit (20) to control the brightness of the light-emitting unit (20); the second substrate (12) is provided with a containing opening (120) penetrating through the second substrate (12), the containing opening (120) and the first substrate (11) form an open structure containing cavity, and the driving chip (30) is contained in the containing cavity. The LED device with the built-in driving chip can improve the light-emitting efficiency of the light-emitting unit, and further improve the performance of the LED device.

Description

Technical Field

[0001] This invention relates to the technical field of LED devices, and in particular to an LED device with a built-in driver chip and its fabrication method. Background Technology

[0002] Full-color LED devices with built-in driver chips (i.e., IC chips) are widely used in various LED display products, such as transparent advertising screens and ultra-thin all-in-one machines, due to their good display effect, low power consumption, and thin and light design.

[0003] Existing full-color LED devices with built-in ICs use a bracket structure for packaging, fixing the driver chip and LED light-emitting chip on the same bracket. Electrical connections for positive and negative terminals, inputs, and outputs are then established using wire bonding. This process requires wire bonding, increasing the risk of defects, processing time, and production costs. The introduction of flip-chip technology reduces the cost of packaging full-color LED devices with built-in driver chips. Using a solder-brushing process with a PCB board, the driver chip and LED light-emitting chip are electrically connected via die bonding, eliminating the need for wire bonding and effectively reducing material waste.

[0004] However, regardless of whether it is wire bonding or flip-chip technology, the existing driver chip is relatively larger than the commonly used LED light-emitting chip. The height of the driver chip is often higher than the light-emitting surface of the LED light-emitting chip (the height difference between the two is often 100-150μm). Therefore, after packaging, it will block the light emission of the LED light-emitting chip, affecting its luminous efficiency and thus affecting the performance of the LED device. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or deficiencies of the prior art. On the one hand, it provides an LED device with a built-in driver chip, which can improve the luminous efficiency of the light-emitting unit and thus improve the performance of the LED device.

[0006] An LED device with a built-in driver chip includes a first substrate and a second substrate stacked along the thickness direction, a light-emitting unit disposed on the second substrate, and a driver chip disposed on the first substrate; the driver chip is electrically connected to the light-emitting unit to control the brightness of the light-emitting unit; the second substrate has a receiving opening penetrating the second substrate, the receiving opening and the first substrate forming an open receiving cavity, and the driver chip is housed in the receiving cavity.

[0007] Compared to existing technologies, the LED device with a built-in driver chip of the present invention reduces the setting height of the driver chip by setting the driver chip and the light-emitting unit on a first substrate and a second substrate with different heights, thereby reducing the amount of light emitted by the light-emitting unit that is blocked by the large driver chip, thus improving the luminous efficiency of the light-emitting unit and improving the performance of the LED device.

[0008] In one embodiment, the highest point of the driving chip is not higher than the lowest point of the light-emitting surface of the light-emitting unit.

[0009] In one embodiment, the top of the first substrate is provided with a driving pad assembly, and the driving chip is electrically connected to the driving pad assembly; the top of the second substrate is provided with a light-emitting pad assembly, the light-emitting unit is electrically connected to the light-emitting pad assembly, and the light-emitting pad assembly is electrically connected to the driving pad assembly.

[0010] In one embodiment, a connection structure is provided between the first substrate and the second substrate, the connection structure partially penetrating the second substrate, and the driving pad assembly is electrically connected to the light-emitting pad assembly through the connection structure.

[0011] In one embodiment, the driver chip has a power supply terminal, a ground terminal, and a driver terminal; the driver pad assembly includes a power supply pad electrically connected to the power supply terminal, a ground pad electrically connected to the ground terminal, and a driver pad electrically connected to the driver terminal, wherein the power supply pad, the ground pad, and the driver pad are not in contact with each other; the light-emitting unit has an A-pole and a B-pole with opposite polarities; the light-emitting pad assembly includes an A-pole pad electrically connected to the A-pole of the light-emitting unit and a B-pole pad electrically connected to the B-pole of the light-emitting unit, wherein the A-pole pad and the B-pole pad are not in contact with each other; the driver pad is electrically connected to the A-pole pad through the connection structure; the ground pad is electrically connected to the B-pole pad through the connection structure.

[0012] In one embodiment, the driver chip has three driving terminals; the driver pad assembly includes three driver pads that correspond one-to-one with the driving terminals; the number of light-emitting units is three, and the second substrate is provided with light-emitting pad assemblies that correspond one-to-one with the light-emitting units. The A-pole of each light-emitting unit is electrically connected to the A-pole pad in a group of light-emitting pad assemblies, and its B-pole is electrically connected to the B-pole pad in the same group of light-emitting pad assemblies. Each driver pad is electrically connected to one of the A-pole pads through the connection structure, and each of the B-pole pads is electrically connected to the ground pad through the connection structure.

[0013] In one embodiment, the driver chip further has a signal input terminal and a signal output terminal; the driver pad assembly includes a signal input pad electrically connected to the signal input terminal of the driver chip, and a signal input pad electrically connected to the signal output terminal of the driver chip.

[0014] In one embodiment, the connection structure includes a conductive component, the conductive component including a conductive element corresponding to each of the A-pole pads, the conductive element penetrating the second substrate along the thickness direction, and each drive pad being electrically connected to an A-pole pad through one of the conductive elements.

[0015] In one embodiment, the connection structure further includes a connection component connected to the conductive component. The connection component is disposed on the second substrate at a position outside the receiving opening. The connection component is mirror-symmetrical to the driving pad component, such that when the second substrate is stacked on top of the first substrate, the connection component overlaps with the driving pad component.

[0016] On the other hand, the present invention also provides a method for fabricating an LED device with a built-in driver chip, comprising the following steps:

[0017] A drive pad assembly is formed on the top of the first substrate, and an accommodating opening is formed in the second substrate that penetrates the second substrate;

[0018] A connection structure is formed at the bottom of the second substrate;

[0019] The second substrate is placed on top of the first substrate, so that the connection structure and the drive pad assembly make corresponding contact.

[0020] A light-emitting pad assembly is formed on the top of the second substrate;

[0021] A driver chip is mounted on the driver pad assembly located at the bottom of the accommodating opening, and a light-emitting unit is mounted on the light-emitting pad assembly.

[0022] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of an exemplary LED device with a built-in driver chip according to the present invention.

[0024] Figure 2 This is a top front view of the first substrate in an exemplary LED device with a built-in driver chip according to the present invention.

[0025] Figure 3 This is a top front view of the second substrate in an exemplary LED device with a built-in driver chip according to the present invention.

[0026] Figure 4 This is a top rear view of the second substrate in an exemplary LED device with a built-in driver chip according to the present invention.

[0027] Figure 5 This is a top front view of an exemplary LED device with a built-in driver chip according to the present invention.

[0028] Figure 6 This is a top front view of an exemplary LED device with a built-in driver chip, without the driver chip and light-emitting unit installed.

[0029] Figure 7 This is a top front view of an exemplary LED device with a built-in driver chip, having the driver chip and light-emitting unit installed.

[0030] Figure 8 This is a cross-sectional view (uncut) of the first substrate in an exemplary LED device with a built-in driver chip according to the present invention.

[0031] Figure 9 This is a cross-sectional view (uncut) of the first substrate and the second substrate after being stacked in an exemplary LED device with a built-in driver chip according to the present invention.

[0032] Figure 10 This is a cross-sectional view (uncut) of an LED device with an exemplary built-in driver chip according to the present invention, after the first substrate and the second substrate are stacked to form a through hole.

[0033] Figure label:

[0034] 11. First substrate; 110. Drive pad assembly; 1100. Power supply pad; 1102. Ground pad; 1104. Drive pad; 1104a. First drive pad; 1104b. Second drive pad; 1104c. Third drive pad; 1106. Signal input pad; 1108. Signal output pad;

[0035] 12. Second substrate; 120. Accommodating opening; 122. Light-emitting pad assembly; 122a. A-pole pad; 122b. B-pole pad; 124. Connection structure; 1240. Connection component; 1242. Conductive component;

[0036] 20. Light-emitting unit;

[0037] 30. Driver chip;

[0038] 40. Through hole;

[0039] 50. Pin assembly. Detailed Implementation

[0040] Existing LED devices with built-in driver chips typically have the driver chip and LED device die-bonded on the same side of the substrate. However, due to the relatively large size of existing driver chips and the relatively small size and thickness of the light-emitting unit, the driver chip often protrudes above the light-emitting surface of the light-emitting unit. This results in the driver chip blocking the light emitted by the light-emitting unit after packaging, affecting the luminous efficiency of the light-emitting unit. To solve this problem, this invention reduces the height of the driver chip, preventing it from blocking the light emitted by the light-emitting unit, thereby improving the luminous efficiency of the light-emitting unit.

[0041] Based on the above technical concept, this invention provides an open accommodating cavity in a substrate structure formed by stacking two substrates, and then houses the driver chip within this cavity, thereby reducing the height of the driver chip and preventing it from obstructing the light-emitting unit. Furthermore, electrical connection between the driver chip and the light-emitting unit is achieved through wiring on the two substrates.

[0042] The present invention will now be described in detail with reference to the accompanying drawings.

[0043] Figure 1-7 The specific structure of an exemplary LED device with a built-in driver chip according to the present invention is shown. Figure 1 As shown, the device includes a first substrate 11 and a second substrate 12 stacked sequentially from bottom to top along the thickness direction. A light-emitting unit 20 is disposed on the second substrate 12, and a driving chip 30 is disposed on the first substrate 11. The driving chip 30 is electrically connected to the light-emitting unit 20 to control the brightness of the light-emitting unit 20. The light-emitting unit 20 can be an LED light-emitting chip or an LED lamp bead. The specific structure of the LED device in this embodiment is described below using an LED light-emitting chip as an example.

[0044] Specifically, the first substrate 11 and the second substrate 12 are square or rectangular in shape. The second substrate 12 has a receiving opening 120 extending through it along its thickness direction. The receiving opening 120 is rectangular or square, and it, together with the first substrate 11 located below it, forms an open receiving cavity. The driver chip 30 is housed within this cavity. A driver pad assembly 110 is disposed on the top of the first substrate 11. The driver pad assembly 110 includes a power supply pad 1100, a ground pad 1102, and three driver pads 1104. The power supply pad 1100, ground pad 1102, and driver pads 1104 are all exposed at the bottom of the receiving cavity. The three driver pads 1104 are designated as the first driver pad 1104a, the second driver pad 1104b, and the third driver pad 1104c. The driver chip 30 has a power supply terminal, a ground terminal, and three driving terminals. When the driver chip 30 is die-bonded to the driving pad assembly 110 within the accommodating cavity, the power supply terminal of the driver chip 30 is in contact with the power supply pad 1100, the ground terminal is in contact with the ground pad 1102, and the three driving terminals are in contact with the first driving pad 1104a, the second driving pad 1104b, and the third driving pad 1104c, respectively. The top of the second substrate 12 is provided with three sets of light-emitting pad assemblies 122 corresponding one-to-one with the driving pads 1104. Each set of light-emitting pad assemblies 122 includes an A-pole pad 122a and a B-pole pad 122b. The three sets of light-emitting pad assemblies 122 are used for die-bonding three light-emitting chips. The light-emitting chip has A and B electrodes with opposite polarities. When the light-emitting chip is die-bonded to the second substrate 12, the A and B electrodes of each light-emitting chip are electrically connected to the A electrode pad 122a and B electrode pad 122b of a set of light-emitting pads 122, respectively. The three light-emitting chips are a red light-emitting chip, a green light-emitting chip, and a blue light-emitting chip. Here, the light-emitting chip can be at least one of a standard chip, a flip chip, and a vertically structured chip, but a flip chip is preferred. Flip chips can be directly mounted on the pads for electrical connection without the need for wire bonding, making the packaged LED device more reliable and the outer surface of the device more regular and aesthetically pleasing.

[0045] Thus, by forming a cavity by stacking two substrates along the thickness direction and housing the driver chip 30 within this cavity, the overall height of the driver chip 30 can be reduced, minimizing its obstruction of the light emitted by the light-emitting chip. This improves the luminous efficiency of the light-emitting chip and ultimately enhances the performance of the LED device. Preferably, the height of the highest point of the driver chip 30 is not higher than the height of the lowest point of the light-emitting surface of the light-emitting chip. This more effectively prevents the larger driver chip 30 from obstructing the light emitted from the light-emitting surface of the light-emitting chip.

[0046] Furthermore, to achieve electrical connection between the driver chip 30 and the light-emitting chip located on different substrates, a connection structure 124 is provided between the first substrate 11 and the second substrate 12. The connection structure 124 consists of a connection component 1240 and a conductive component 1242 connected to the connection component 1240. The connection component 1240 is located at the bottom of the second substrate 12, outside the receiving opening 120. The connection component 1240 at the bottom of the second substrate 12 is mirror-symmetrical to the driving pad assembly 110 at the top of the first substrate 11. In other words, the connection component 1240 includes multiple connectors that correspond one-to-one with each pad in the driving pad assembly 110 and do not contact each other. Thus, when the second substrate 12 is stacked on the first substrate 11, the connection component 1240 overlaps with the driving pad assembly 110, and each connector contacts its corresponding pad in the driving pad assembly 110 to achieve electrical connection. The conductive component 1242 includes multiple conductive elements corresponding to the connectors, specifically conductive vias penetrating the second substrate 12 along its thickness direction. Figure 1-7 In the illustrated embodiment, the conductive component 1242 includes six conductive elements, with each pair of conductive elements corresponding to a set of light-emitting pad assemblies 122. One of these two conductive elements is electrically connected to an A-pole pad 122a, and the other is electrically connected to a B-pole pad 122b. Thus, the three driving pads 1104 disposed on the first substrate 11 are electrically connected to the three A-pole pads disposed on the second substrate 12 via the connection structure 124, and the ground pad 1102 disposed on the first substrate 11 is also electrically connected to the B-pole pad via the connection structure 124. The three driving terminals 304 of the driving chip 30 are electrically connected to the three light-emitting units 20 via the driving pad assembly 110, the connection structure 124, and the light-emitting pad assembly 122, respectively. The brightness of the light-emitting units 20 can be controlled by supplying power to or from the three light-emitting units 20.

[0047] Thus, by setting a connection structure 124 between the first substrate 11 and the second substrate 12, not only can the driving chip 30 located on different substrates be electrically connected to the light-emitting unit 20, but most of the wiring of the LED device is also hidden between the first substrate 11 and the second substrate 12, making the packaged LED device more reliable and the device appearance more aesthetically pleasing.

[0048] Of course, as an alternative, the connection structure 124 may not include the connection component 1240, as long as it is ensured that each conductive element in the conductive component 1242 can be electrically connected to the corresponding pad in the drive pad component 110 after the first substrate 11 and the second substrate 12 are stacked.

[0049] To connect the LED device with the built-in driver chip to an external circuit, a pin assembly 50 is provided at the bottom of the first substrate 11 of the LED device with the built-in driver chip. The pin assembly 50 includes a power supply pin (not shown) and a ground pin (not shown), which are located at the corners of the first substrate 11. Through-holes 40 are provided at the corresponding positions of the power supply pin (not shown) and ground pin (not shown) on the first substrate 11, and the through-holes 40 are filled with conductive material. The power supply pad 1100 and ground pad 1102 on the top of the first substrate 11 are electrically connected to the corresponding power supply pin (not shown) and ground pin (not shown) through a through-hole 40, respectively. Thus, power can be supplied to the LED device with the built-in driver chip through an external circuit.

[0050] In one embodiment, to assemble the aforementioned LED devices with multiple built-in driver chips onto a circuit board to form an LED display module or LED display panel, and to control the LED devices with each built-in driver chip under the same control signal to adjust the brightness of the corresponding light-emitting unit 20, the driver chip 30 also has a signal input terminal and a signal output terminal. The driver pad assembly 110 further includes a signal input pad 1106 electrically connected to the signal input terminal of the driver chip 30, and a signal output pad 1108 electrically connected to the driver chip 30. The signal input pad 1106 and the signal output pad 1108 are also located at the bottom of the accommodating cavity. Corresponding to the signal input pad 1106 and the signal output pad 1108, a signal input pin (not shown) and a signal output pin (not shown) are also provided at the corner of the bottom of the first substrate 11. The first substrate 11 also has through-holes 40 filled with conductive material at the corresponding signal input pins (not shown) and signal output pins (not shown). Signal input pads 1106 and 1108 are electrically connected to the signal input pins (not shown) and signal output pins (not shown) respectively through through-holes 40. In this way, multiple LED devices with built-in driver chips can be mounted on the circuit board via pin assemblies to form an LED display module. The LED devices within the LED display module receive control signals at the signal input terminal to control the brightness of the corresponding three light-emitting units 20, and simultaneously output control signals to the LED devices connected in series or parallel through the signal output terminal to regulate the display effect of the LED display module.

[0051] Furthermore, the present invention also provides a method for fabricating the aforementioned LED device with a built-in driver chip, such as... Figure 8-10 As shown, it includes the following steps:

[0052] S1: A drive pad assembly 110 is formed on the top of the first substrate 11;

[0053] Specifically, such as Figure 8As shown, a BT resin board with a thickness of 0.1-0.2 mm and a copper layer plated on the top is etched to form a drive pad assembly 110. The drive pad assembly 110 includes a power supply pad 1100, a ground pad 1102, a signal input pad 1106, a signal output pad 1108, and three drive pads 1104 (first drive pad 1104a, second drive pad 1104b, and third drive pad 1104c) to form a first substrate 11, wherein the thickness of the copper layer is 10-15 μm.

[0054] Furthermore, an accommodating opening 120 is formed on the second substrate 12, extending through the second substrate 12 in the thickness direction;

[0055] Specifically, another BT resin board with a thickness of 0.2-0.4mm and copper plating on both the top and bottom is used to create a receiving opening 120. The size of the receiving opening 120 is (a+30μm)*(b+30μm), where a and b are the length and width of the driving chip 30, respectively. By setting the receiving opening 120 to have a cross-sectional area larger than that of the driving chip 30, there is a certain gap between the driving chip 30 and the sidewall of the receiving cavity during die bonding. This can improve the problem of the driving chip 30 being prone to twisting or misalignment during die bonding, effectively improving the process efficiency and yield of the sample.

[0056] Then, the connecting component 1240 is etched on the copper layer at the bottom of the BT resin board to form the second substrate 12. The connecting component 1240 includes multiple connectors. The distribution of each connector is mirror-symmetrical to the distribution of each pad in the drive pad assembly 110, so that when the second substrate 12 is stacked on top of the first substrate 11, the connecting component 1240 overlaps with the drive pad assembly 110.

[0057] S2: The second substrate 12 is stacked on top of the first substrate 11, so that the drive pad assembly 110 contacts the connection assembly 1240, and then the first substrate 11 and the second substrate 12 are laminated together.

[0058] Specifically, the lamination pressure range is 250-5000 PSI, and the temperature is controlled at 150-190℃. The high temperature and high pressure soften and fuse the driving pad assembly 110 on the top of the first substrate 11 and the connecting assembly 1240 on the bottom of the second substrate 12 to achieve the bonding effect.

[0059] During lamination bonding, a prepreg, specifically glass fiber or polyimide, can be added between the first substrate 11 and the second substrate 12. These materials can bond well with the BT resin board. Thus, by adding the prepreg, the bonding force between the first substrate 11 and the second substrate 12 is enhanced, thereby improving the reliability of the device.

[0060] S3: A light-emitting pad assembly 122 is formed on the top of the second substrate 12;

[0061] Specifically, by etching the copper layer on the top of the second substrate 12, three sets of light-emitting pad assemblies 122 are formed. Each set of light-emitting pad assemblies 122 includes A-pole pads 122a and B-pole pads 122b that do not contact each other.

[0062] Holes are drilled and filled with conductive material at the positions of each A-pole pad 122a and each B-pole pad 122b on the second substrate 12 to form conductive components 1242, such that each conductive component 1242 is electrically connected to an A-pole pad 122a or a B-pole pad 122b and a connecting component 1240.

[0063] S4: A driver chip 30 is die-bonded on the driver pad assembly 110 located at the bottom of the accommodating opening 120, and a light-emitting unit 20 is die-bonded on the light-emitting pad assembly 122 to form an LED device with a built-in driver chip.

[0064] In this way, the height difference between the highest point of the driver chip 30 and the light-emitting surface of the light-emitting unit 20 can be reduced to <50μm. By reducing the height of the driver chip 30, the obstruction of light emitted by the light-emitting unit 20 by the driver chip 30 can be reduced. Among these options, reducing the height of the driver chip 30 to a height no higher than the light-emitting surface of the light-emitting unit 20 is optimal, as it can more effectively prevent light emitted from the light-emitting surface of the light-emitting unit 20.

[0065] To enable the LED device with the built-in driver chip to connect to external circuits, after forming the driver pad assembly 110 in step S1, pin assemblies 50 are provided at the four corners of the bottom of the first substrate 11. The pin assemblies include power supply pins (not shown), ground pins (not shown), signal input pins (not shown), and signal output pins (not shown). Then, through-holes 40 are drilled at the corresponding four pin positions on the first substrate 11. Conductive material is filled into the through-holes 40, allowing the power supply pad 1100, ground pad 1102, signal input pad 1106, and signal output pad 1108 to be electrically connected to the power supply pin (not shown), ground pin (not shown), signal input pin (not shown), and signal output pin (not shown), respectively, through a through-hole. Thus, the LED device with the built-in driver chip can connect to external circuits to receive power and control signals.

[0066] Alternatively, after forming the light-emitting pad assembly 122 in step S3, holes are drilled at the four corners of the second substrate 12 to form through holes 40 that penetrate the first substrate 11 and the second substrate 12 and are filled with conductive material. The pin assembly 50 at the bottom of the first substrate 11 is connected through the through holes 40.

[0067] Compared to existing technologies, the LED device with a built-in driver chip, its fabrication method, and the LED display module of this invention reduce the height of the driver chip by placing the driver chip and the light-emitting unit on a first substrate and a second substrate with a height difference. This reduces the amount of light the driver chip obstructs from the light-emitting surface of the light-emitting unit, thereby improving the luminous efficiency of the light-emitting unit and ultimately enhancing the performance of the LED device. Furthermore, by establishing a conductive connection structure between the first and second substrates, an electrical connection is achieved between the driver chip on the first substrate and the light-emitting unit on the second substrate. This allows the driver chip to control the brightness of the light-emitting unit, while simultaneously hiding the wiring on both substrates between them, preventing damage to the wiring and improving the reliability of the device. It also results in a cleaner and more aesthetically pleasing appearance for the LED device. This invention is ingeniously conceived, simple in structure, and highly practical.

[0068] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments and claims of this application are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that, unless otherwise stated, “a plurality” means two or more; the terms “first,” “second,” “third,” etc., are used only to distinguish and not to describe a particular order or sequence, nor should they be construed as indicating or implying relative importance. The term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items. When the above description relates to drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0069] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for fabricating an LED device with a built-in driver chip, characterized in that: The method comprises the following steps: S1: preparing a first substrate (11) and a second substrate (12) in a square or rectangular shape, forming a driving pad assembly (110) on the top of the first substrate (11), and then forming a pin assembly (50) on the bottom of the first substrate (11), wherein the driving pad assembly (110) comprises a power supply pad (1100), a ground pad (1102), a signal input pad (1106), a signal output pad (1108), and three driving pads (1104) which are not in contact with each other, the pin assembly (50) comprises a power supply pin, a ground pin, a signal input pin, and a signal output pin, which are distributed at the four corner positions of the first substrate (11); then, holes are drilled at the positions of the corresponding four pins of the first substrate (11) to form through holes (40), and the through holes (40) are filled with conductive material, so that the power supply pad (1100), the ground pad (1102), the signal input pad (1106), and the signal output pad (1108) are respectively electrically connected to the power supply pin, the ground pin, the signal input pin, and the signal output pin through the through holes; And, a containing opening (120) is formed in the second substrate (12) to pass through the second substrate (12), and a connecting structure (124) is formed on the bottom of the second substrate (12), wherein the connecting structure (124) comprises a connecting assembly (1240) and a conductive assembly (1242) connected to the connecting assembly (1240), the connecting assembly (1240) is arranged on the bottom of the second substrate (12) at a position outside the containing opening (120), the connecting assembly (1240) formed on the bottom of the second substrate (12) is mirror-symmetric to the driving pad assembly (110) formed on the top of the first substrate (11), and the conductive assembly (1242) penetrates the second substrate (12); S2: covering the second substrate (12) on the top of the first substrate (11) so that the connecting assembly (1240) of the connecting structure (124) is in corresponding contact with the driving pad assembly (110), so that the connecting assembly (1240) coincides with the driving pad assembly (110); then, the driving pad assembly (110) on the top of the first substrate (11) and the connecting assembly (1240) on the bottom of the second substrate (12) are softened and fused by high temperature and high pressure, so that the first substrate (11) and the second substrate (12) are connected together; S3: Forming three groups of light-emitting pad assemblies (122) at positions where the conductive assemblies on the top of the second substrate (12) are penetrated, so that the three groups of light-emitting pad assemblies (122) are respectively electrically connected with three driving pads (1104) through the connecting structures (124), wherein the three groups of light-emitting pad assemblies (122) are arranged in sequence along a first edge length direction of the second substrate, and the areas where the three groups of light-emitting pad assemblies (122) are located and the positions where the accommodating openings (120) are located are distributed in parallel along a second edge length direction of the second substrate, the second edge length direction being perpendicular to the first edge length direction; S4: Mounting a driving chip (30) on the driving pad assembly (110) located at the bottom of the accommodating opening (120), wherein the driving chip (30) has a power supply end electrically connected with the power supply pad (1100), a ground end electrically connected with the ground pad (1102), a signal input end electrically connected with the signal input pad (1106), a signal output end electrically connected with the signal output pad (1108), and three driving ends, wherein each driving end is electrically connected with a corresponding driving pad (1104); And mounting one light-emitting unit (20) on each group of light-emitting pad assemblies (122).

2. An LED device with a built-in driver chip prepared according to the preparation method of claim 1, characterized in that: A display device includes a first substrate (11) and a second substrate (12) stacked in a thickness direction, a light-emitting unit (20) provided on the second substrate (12), and a driving chip (30) provided on the first substrate (11); The driving chip (30) is electrically connected with the light-emitting unit (20) to control brightness of the light-emitting unit (20). The second substrate (12) is provided with an accommodating opening (120) penetrating the second substrate (12), the accommodating opening (120) and the first substrate (11) form an open structure accommodating cavity, and the driving chip (30) is accommodated in the accommodating cavity.

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