LED display array and preparation method thereof

Abstract

The invention discloses an LED display array and a preparation method thereof, and relates to the field of LED display, and the preparation method of the LED display array comprises the following steps: providing a substrate, an LED chip and a control chip; a plurality of control chips are placed on the first surface of the substrate, port electrodes of the control chips make contact with the first surface, a plurality of LED chips are placed on the first surface of the substrate, a single-color LED group composed of a plurality of LED chips with the same light emitting color is formed, and each control chip corresponds to at least one single-color LED group; a packaging body wrapping all the control chips and the LED chips is arranged outside the substrate; and respectively preparing an upper wiring layer and a lower wiring layer on the upper surface and the lower surface of the packaging body. The preparation process of the LED display array is simpler, the control chip and the LED chip can be reliably protected, and the use reliability and the quality of the product can be improved.

Description

Technical Field

[0001] This invention relates to the field of LED display technology, and in particular to an LED display array and its fabrication method. Background Technology

[0002] The display screen comprises a large number of LED chips, which emit light to display a wealth of visual information.

[0003] Currently, some LED display arrays drive the corresponding LED chips to emit light through row and column signal lines in a scanning manner, making it impossible to independently control the emission of each LED chip using digital signals. Furthermore, during display fabrication, mass transfer equipment is required to precisely place each LED chip in a designated position, demanding high precision but resulting in low efficiency. Additionally, the reliability of the LED chips is crucial; if any LED chip has quality issues, the screen will exhibit dead pixels such as black spots or bright spots, affecting the display quality.

[0004] Some LED display arrays include a circuit board with wiring and multiple LED chip packaging units distributed on the circuit board. Each LED chip packaging unit includes a packaged LED chip and several exposed pads. The LED chip packaging units need to be connected to the circuit board by a bonding process, which is relatively complex. The product quality is easily affected by the soldering quality between the LED chip packaging units and the circuit board. In addition, each LED chip packaging unit needs to occupy a certain volume, resulting in a large circuit board area and a large product size.

[0005] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects.

[0006] The above content is only used to help understand the technical solution of this application and does not constitute an admission that the above is prior art. Summary of the Invention

[0007] The purpose of this invention is to provide an LED display array and its manufacturing method to improve its operational reliability.

[0008] To achieve the above-mentioned objectives, in a first aspect, the present invention proposes a method for fabricating an LED display array, characterized by comprising the following steps:

[0009] S1. Provide a substrate, an LED chip, and a control chip, wherein the LED chip includes an electrode pair, and the electrode pair includes a first electrode and a second electrode located on opposite sides of the LED chip;

[0010] S2. A plurality of control chips are placed on the first surface of the substrate, with the port electrodes of the control chips in contact with the first surface. A plurality of LED chips are placed on the first surface of the substrate to form a monochromatic LED group composed of a plurality of LED chips with the same emitting color. Each control chip corresponds to at least one monochromatic LED group.

[0011] S3. An encapsulation covering all the control chips and LED chips is provided on the outside of the substrate;

[0012] S4. An upper wiring layer and a lower wiring layer are respectively prepared on the upper and lower surfaces of the package. The control chip and the corresponding monochrome LED group, as well as multiple control chips, are electrically connected through the lower wiring layer.

[0013] Furthermore, in step S2, when multiple LED chips are placed on the first surface of the substrate, multiple LED chips with the same emission color are randomly scattered in the same target area to form a monochromatic LED group composed of multiple LED chips with the same emission color. LED chips whose second electrode is in contact with the first surface are called effective LED chips, and LED chips whose second electrode is not in contact with the first surface are called ineffective LED chips.

[0014] Furthermore, in step S2, each control chip is provided with three monochrome LED groups, and the LED chips in the three monochrome LED groups corresponding to the same control chip emit different colors.

[0015] Furthermore, in step S2, each group of monochrome LEDs contains no fewer than 8 LED chips.

[0016] Furthermore, in step S2, randomly scattering multiple LED chips of the same emission color in the same target area includes: pouring the multiple LED chips of the same emission color into the target area.

[0017] Further, in step S2, randomly distributing multiple LED chips of the same emission color in the same target area includes:

[0018] Multiple LED chips of the same color are placed in a liquid to form an LED paste;

[0019] The LED paste is transferred to the target area.

[0020] Furthermore, the LED paste is transferred to the target area by screen printing, embossing, spraying, or printing.

[0021] Further, the upper wiring layer includes an upper conductive line and an upper insulating layer, and the lower wiring layer includes a lower conductive line and a lower insulating layer. Step S4, in which the upper wiring layer and the lower wiring layer are fabricated on the upper and lower surfaces of the package, respectively, includes the following steps:

[0022] Remove the substrate to expose the second electrode of the active LED chip and the port electrode of the control chip;

[0023] Upper conductive lines and lower conductive lines are respectively fabricated on the upper and lower surfaces of the package, wherein the lower surface is the surface of the package that exposes the port electrodes of the control chip;

[0024] Prepare a first metallized via connecting the upper conductive line and the lower conductive line;

[0025] An upper insulating layer and a lower insulating layer are respectively prepared on the upper and lower surfaces of the package, with the upper insulating layer covering the surface of the upper conductive line and the lower insulating layer covering the surface of the lower conductive line.

[0026] Furthermore, the lower conductive line includes a power supply line, a ground line, a signal line, and a connecting line. The control chip is electrically connected to the power supply line and the ground line. Multiple control chips are connected in series through the signal line to transmit digital signals. The second electrode of the effective LED chip is connected to the control chip through a connecting line. The first electrode of the effective LED chip is connected to the power supply line or the ground line through the upper conductive line and the first metallized via.

[0027] Furthermore, in step S4, before preparing the upper conductive line, the following step is also included: thinning the upper surface of the package to expose the first electrode of the LED chip.

[0028] Furthermore, the center of gravity of the LED chip is close to the second electrode;

[0029] The LED chip includes a metal mass block connected to its second electrode; and / or,

[0030] The cross-sectional area of ​​the end where the second electrode of the LED chip is located is larger than the cross-sectional area of ​​the end where the first electrode is located.

[0031] Furthermore, the LED chip is in the shape of a cuboid or a cube;

[0032] The LED chip includes two sets of electrode pairs, with the second electrodes of each set of electrode pairs located on two adjacent surfaces of the LED chip; or,

[0033] The LED chip includes three sets of electrode pairs, with the second electrodes of the three sets of electrode pairs located on three adjacent surfaces of the LED chip.

[0034] Secondly, the present invention proposes an LED display array, comprising:

[0035] Multiple monochrome LED groups, each monochrome LED group including multiple LED chips with the same emitting color, each LED chip including an electrode pair, the electrode pair including a first electrode and a second electrode located on opposite sides of the LED chip;

[0036] Multiple control chips, each control chip including multiple port electrodes, and each control chip correspondingly having at least one monochrome LED group;

[0037] The package covers the control chip and all the LED chips.

[0038] An upper wiring layer is disposed on the upper surface of the package; and,

[0039] A lower wiring layer is disposed on the lower surface of the package, and the control chip and the corresponding monochrome LED group, as well as multiple control chips, are electrically connected through the lower wiring layer.

[0040] Furthermore, the position and orientation of the LED chips in the monochromatic LED group are random. LED chips whose second electrode and the port electrode are located on the same plane are called effective LED chips, and LED chips whose second electrode is not located on the same plane as the port electrode are called ineffective LED chips. The control chip is electrically connected to the second electrode of the effective LED chip in the corresponding monochromatic LED group.

[0041] Furthermore, multiple control chips are connected in series to transmit digital signals.

[0042] Furthermore, the multiple port electrodes of the control chip include a first signal transmission electrode and a second signal transmission electrode for signal transmission, and the first signal transmission electrode of the former control chip and the second signal transmission electrode of the latter control chip are electrically connected.

[0043] Furthermore, the lower wiring layer includes lower conductive lines and a lower insulating layer covering the lower conductive lines, wherein the lower conductive lines include power supply lines, ground lines, signal lines and connecting lines;

[0044] The first signal transmission electrode of the control chip described above and the second signal transmission electrode of the control chip described below are connected by the signal line;

[0045] The control chip is connected to the power supply line and the ground line;

[0046] The upper wiring layer includes an upper conductive line electrically connected to the first electrode of the active LED chip and an upper insulating layer covering the upper conductive line. The upper conductive line is connected to the power supply line or the ground line through a first metallized via through the package.

[0047] Furthermore, the lower wiring layer includes a power supply port pad, a ground port pad, and a signal port pad exposed on the lower insulating layer. The power supply port pad is electrically connected to the power supply line for connecting to an external power source; the ground port pad is electrically connected to the ground line; and the signal port pad is electrically connected to the first signal transmission electrode of the first control chip for inputting control signals.

[0048] Furthermore, each of the control chips is provided with three monochrome LED groups, and the LED chips in the three monochrome LED groups emit different colors.

[0049] Compared with existing technologies, the present invention has the following advantages: According to at least one embodiment of the present invention, multiple control chips and multiple monochrome LED groups of an LED display array are packaged in the same package and electrically connected through upper and lower wiring layers located on both surfaces of the package. This simplifies the manufacturing process and provides reliable protection for the control chips and LED chips, thus improving product reliability and quality. Furthermore, compared to bonding individual LED chip packaging units to a circuit board, the spacing between adjacent light-emitting units can be smaller, reducing product size. Moreover, since a monochrome LED group comprises multiple LED chips, even with damaged LED chips, the monochrome LED group can still emit light normally, significantly reducing the reliability requirements of the LED chips, increasing process tolerance, and resulting in a more reliable LED display array. Attached Figure Description

[0050] Figure 1a This is a schematic diagram showing the positions of the control chip and monochrome LED group in some embodiments of the present invention. In the figure, the boundaries between the light-emitting units are indicated by a single-dotted line.

[0051] Figure 1b This is a cross-sectional view of a substrate surface with a control chip and a group of monochrome LEDs.

[0052] Figure 2 This is a schematic diagram showing the positions of the control chip and the group of monochrome LEDs in a single light-emitting unit.

[0053] Figure 3 This is a schematic diagram showing that, in some embodiments of the present invention, the control chip and the LED chip are placed on the same surface of the substrate.

[0054] Figure 4 yes Figure 3 The diagram shown is a schematic of the structure with an encapsulation.

[0055] Figure 5 yes Figure 4 The diagram shown illustrates the structure with an upper wiring layer and a lower wiring layer.

[0056] Figure 6 This is a schematic diagram showing the positions of the upper conductive lines and monochrome LED groups in some embodiments of the present invention.

[0057] Figure 7 yes Figure 4 The diagram shown illustrates the process of removing the substrate from the structure.

[0058] Figure 8 yes Figure 7 The diagram shown is a schematic of the structure after the conductive wires have been fabricated.

[0059] Figure 9 This is a schematic diagram of some embodiments of the present invention where the package body has upper and lower conductive lines on both sides, which is consistent with... Figure 8 The cross-sectional directions and positions are different.

[0060] Figure 10 yes Figure 9 The diagram shown is a schematic of the fabrication of the first metallized via.

[0061] Figure 11 yes Figure 10 The diagram shows the structure after the upper and lower insulating layers are fabricated on both sides.

[0062] Figure 12 This is a partial cross-sectional schematic diagram of an LED display array according to some embodiments of the present invention.

[0063] Figure 13 This is a schematic diagram showing the connection between the control chip and the monochrome LED group in a single light-emitting unit in some embodiments of the present invention.

[0064] Figure 14 This is a schematic diagram showing the positions of the upper and lower conductive lines in some embodiments of the present invention.

[0065] Figure 15 This is a circuit diagram of an LED display array according to some embodiments of the present invention.

[0066] Figure 16 This is a schematic diagram showing the connection between the port pads and the lower conductive lines in some embodiments of the present invention.

[0067] Figure 17This is a schematic diagram showing the positions of the control chip and monochrome LED array in a single light-emitting unit in some embodiments of the present invention. The LED chip array is distributed in the diagram.

[0068] Figure 18 These are schematic diagrams of several different orientations of LED chips in some embodiments of the present invention.

[0069] Figure 19 This is a schematic diagram of LED chips in some embodiments of the present invention.

[0070] Figure 20 This is a schematic diagram of LED chips in some embodiments of the present invention.

[0071] Figure 21 This is a schematic diagram of LED chips in some embodiments of the present invention.

[0072] Figure 22 This is a three-dimensional schematic diagram of an LED chip according to some embodiments of the present invention.

[0073] Figure 23 yes Figure 22 The diagram shows the front view of the LED chip.

[0074] Figure 24 This is a three-dimensional schematic diagram of an LED chip according to some embodiments of the present invention.

[0075] Figure 25 This is a schematic diagram of the target area when the auxiliary plate blocks part of some embodiments of the present invention. Detailed Implementation

[0076] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0077] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0078] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0079] Some embodiments of the present invention provide a method for fabricating an LED display array (a first method for fabricating an LED display array), which includes the following steps:

[0080] S1. A substrate 6, an LED chip 1, and a control chip 2 are provided. The LED chip 1 includes an electrode pair, comprising a first electrode 10 and a second electrode 11 located on opposite sides of the LED chip 1. One of the first electrode 10 and the second electrode 11 is a positive electrode, and the other is a negative electrode. It is understood that the positions of the first electrode 10 and the second electrode 11 determine the direction of current flow to light up the LED chip 1. In some embodiments, the LED chip 1 is a vertically structured LED chip. By using a vertical chip, luminous efficiency can be guaranteed while significantly reducing the size of the LED chip.

[0081] S2. For example Figure 1a and Figure 1b As shown, multiple control chips 2 are placed on the first surface 60 of the substrate 6, with the port electrodes 20 of the control chips 2 in contact with the first surface 60. Multiple LED chips 1 are also placed on the first surface 60 of the substrate 6, forming a monochromatic LED group composed of multiple LED chips 1 of the same emitting color. Each control chip 2 corresponds to at least one monochromatic LED group. The control chip 2 and its corresponding monochromatic LED group constitute a light-emitting unit 7. The control chip 2 can control the light emission of its corresponding monochromatic LED group. Figure 1 shows a schematic diagram of multiple light-emitting units 7. In the figure, the boundaries of a single light-emitting unit 7 are indicated by a dashed line. Figure 2 and Figure 3 A top view and a cross-sectional view of a light-emitting unit are shown respectively for a clearer description.

[0082] It is understandable that in step S2, the control chip 2 can be placed first and then the LED chip 1, or the LED chip 1 can be placed first and then the control chip 2, or the control chip 2 and the LED chip 1 can be placed simultaneously.

[0083] S3. For example Figure 4 As shown, a package 3 is prepared on the outside of the substrate 6 to cover all the control chip 2 and LED chip 1, so as to fix the control chip 2 and LED chip 1 and provide protection.

[0084] S4. For example Figure 5 As shown, an upper wiring layer 51 and a lower wiring layer 52 are respectively prepared on the upper and lower surfaces of the package 3. The control chip 2 and the corresponding monochrome LED group, as well as multiple control chips 2, are electrically connected through the lower wiring layer 52, so that the control chip 2 can control the corresponding monochrome LED group to emit light.

[0085] Understandably, all light-emitting units 7 are encapsulated within the package 3 and electrically connected via the upper wiring layer 51 and lower wiring layer 52 outside the package 3. This simplifies the manufacturing process and provides reliable protection for the control chip 2 and LED chip 1, thus improving product reliability and quality. Furthermore, compared to bonding individual LED chip packages to the circuit board, the spacing between adjacent light-emitting units 7 can be smaller, reducing product size.

[0086] It is understandable that since a monochrome LED group includes multiple LED chips 1, even if there are damaged LED chips 1, the monochrome LED group can still emit light normally, which greatly reduces the reliability requirements of the LED chips 1, increases the process fault tolerance, and makes the LED display array more reliable in use.

[0087] It is understandable that an LED display array can include a large number of light-emitting units 7 to achieve display functions.

[0088] In some embodiments, such as Figure 5 As shown, the upper wiring layer 51 includes an upper conductive line 510 and an upper insulating layer 511 covering the upper conductive line 510. The lower wiring layer 52 includes a lower conductive line 520 and a lower insulating layer 521 covering the lower conductive line 520. The control chip 2 of the light-emitting unit 7 and the monochrome LED group, as well as the control chips 2 of different light-emitting units 7, are electrically connected through the lower conductive line 520. Each monochrome LED group is connected to the upper conductive line 510. The upper conductive line 510 can cover the entire upper surface of the package 3, or it can be connected to... Figure 6 As shown, a portion of the package 3 has multiple branches connecting to a group of monochrome LEDs.

[0089] Optionally, in step S4, the preparation of the upper wiring layer 51 and the lower wiring layer 52 on the upper and lower surfaces of the package 3 respectively includes the following steps:

[0090] A1. As Figure 7 As shown, the substrate 6 is removed, exposing the second electrode 11 of the effective LED chip 1a and the port electrode 20 of the control chip 2.

[0091] A2. For example Figure 8 and Figure 9As shown, upper conductive lines 510 and lower conductive lines 520 are fabricated on the upper and lower surfaces of the package 3, respectively. The lower surface is the surface of the package 3 that exposes the port electrodes 20 of the control chip 2. Figure 8 and Figure 9 Schematic diagrams showing different cutting directions and positions are provided.

[0092] A3. For example Figure 10 As shown, a first metallized via 50 is prepared to connect the upper conductive line 510 and the lower conductive line 520.

[0093] A4. For example Figure 5 and Figure 11 As shown, an upper insulating layer 511 and a lower insulating layer 521 are prepared on the upper and lower surfaces of the package 3, respectively, with the upper insulating layer 511 covering the surface of the upper conductive line 510 and the lower insulating layer 521 covering the surface of the lower conductive line 520.

[0094] It is understood that the upper insulating layer 511 and the lower insulating layer 521 can cover the entire outer surface of the package 3. Furthermore, in the illustrated embodiment, the size and position of each component (e.g., target area, LED chip, control chip, etc.) are illustrative. For example, when a smaller LED chip 1 is used, its thickness can be less than that of the control chip 2. In this case, a partial structural schematic diagram of a possible LED display array is shown below. Figure 12 As shown, the first electrode 10 of the LED chip 1 can be exposed by thinning a local area on the package 3 (at least corresponding to the monochrome LED group), which facilitates the arrangement of the upper conductive line 510. Optionally, the outer surface of the upper insulating layer 511 is flat so that the insulating material in the area corresponding to the monochrome LED group is thicker, which is beneficial to improving the protection effect.

[0095] Optionally, in step S4, before fabricating the upper conductive line 510, the following step is also included: thinning the upper surface of the package 3 to expose the electrodes of the LED chip 1.

[0096] As a feasible example, such as Figure 13 and Figure 14As shown, the lower conductive line 520 includes a power supply line 5200, a ground line 5201, a signal line 5202, and a connecting line 5203. The power supply line 5200 is used to connect to an external power source, and the ground line 5201 is used for grounding. The control chip 2 is electrically connected to the power supply line 5200 and the ground line 5201 to enable it to work normally. Specifically, some of the port electrodes 20 of the control chip 2 are divided into voltage port electrodes 202 and ground port electrodes 203, a first signal transmission electrode 200, a second signal transmission electrode 201, and a control electrode 204 according to their functions. The voltage port electrode 202 is connected to the power supply line 5200, and the ground port electrode 203 is connected to the ground line 5201. The control electrode 204 is connected to the connecting line 5203. Optionally, the connecting line 5203 is widened to form a larger connecting portion 52030 to electrically connect to more LED chips 1.

[0097] like Figure 14 As shown, Figure 14 A schematic diagram showing the positions of the upper conductive line 510 and the lower conductive line 520 is provided. The upper conductive line 510 is at least partially positioned opposite the connecting line 5203 (specifically, the connecting portion 52030), and is electrically connected to the first electrode 10 of the effective LED chip 1a. It is also connected to the power supply line 5200 or ground line 5201 of the lower conductive line 520 through the first metallized via 50. Obviously, when the first electrode 10 is positive, the upper conductive line 510 is connected to the power supply line 5200, and the control chip 2 drives the LED chip 1 to emit light by inputting a high level to the second electrode 11. When the first electrode 10 is negative, the upper conductive line 510 is connected to the ground line 5201, and the control chip 2 controls the LED chip 1 to emit light by controlling the second electrode 11 to be connected to a low level (e.g., grounded). The target area 61 corresponds to the area where the projections of the upper conductive line 510 and the connecting line 5203 (specifically, the connecting portion 52030) overlap along the thickness direction of the package 3. Optionally, the projection of the upper conductive line 510 completely covers the connecting portion 52030. In this case, the outer contour of the connecting portion 52030 can be regarded as the area of ​​the target region 61.

[0098] like Figure 15As shown, multiple control chips 2 are connected in series via signal lines 5202 to transmit digital signals. Specifically, the second signal transmission electrode 201 (TX port in the figure) of the preceding control chip 2 and the first signal transmission electrode 200 (BRX port in the figure) of the following control chip 2 are electrically connected. The foremost control chip 2 is used to input external control signals. The control signals include the address information of the monochrome LED group and the light emission information corresponding to the address information. The control chip 2 can identify the light emission information corresponding to its own monochrome LED group based on the address information, and control the corresponding monochrome LED group to emit light according to the light emission information. At the same time, the control chip 2 will continue to transmit the control signal to the following control chip 2 so that the following control chip 2 can receive the control signal and control the corresponding monochrome LED group to emit light according to the light emission information corresponding to its own address in the control signal. Figure 15 For ease of illustration, only a portion of the port electrodes of the control chip 2 are shown in the diagram.

[0099] Each row includes multiple light-emitting units 7. The control signals of the light-emitting units 7 in the same row are transmitted in the same direction, while the control signals of adjacent rows are transmitted in opposite directions. Figure 15 In the middle row, the control signal transmission direction of the bottom row light-emitting unit 7 is from left to right, the control signal transmission direction of the middle row light-emitting unit 7 is from right to left, and the control signal transmission direction of the top light-emitting unit 7 is from left to right. Thus, in the two adjacent control chips 2 at the end of adjacent rows, one of the later control chip 2 (e.g., Figure 15 The first signal transmission electrode 200 of 2a) and another preceding control chip 2 (e.g. Figure 15 In section 2b), the second signal transmission electrode 201 is located on the same side and can be easily connected via signal line 5202, facilitating wiring. Control signals can be transmitted to all light-emitting units 7 through the same control signal input terminal. Furthermore, each row of light-emitting units 7 has a ground line 5201 (sub-ground line 52010) and a power supply line (sub-power supply line 52000) on both sides for easy connection to the light-emitting units 7 in that row. In three adjacent rows of light-emitting units 7, two adjacent rows share the same ground line 5201 (sub-ground line 52010) located between them, and another two adjacent rows share the same power supply line 5200 (sub-power supply line 52000) located between them, making the circuit structure more compact.

[0100] In some embodiments, such as Figure 15 and Figure 16As shown, the lower wiring layer 52 also includes multiple port pads exposed outside the LED display array, enabling the LED display array to be easily connected to external circuits (such as the control circuit of the display), for example, to achieve power input, grounding, and input control signals. The port pads are all located on the surface of the lower insulating layer 521 away from the package 3 for easy wiring. Optionally, the lower wiring layer 52 includes a power supply port pad 523, a signal port pad 525, and a ground port pad 524. The power supply port pad 523 is connected to the power supply line 5200, the signal port pad 525 is connected to the signal line 5202 connected to the first signal transmission electrode 200 of the first control chip 2, and the ground port pad 524 is connected to the ground line 5201. Since the port pads and the lower conductive lines 520 are separated by the lower insulating layer 521, they can be connected through a second metallized via 522 passing through the lower insulating layer 521.

[0101] Optionally, the port pads are all located on the surface of the lower insulating layer 521 facing away from the package body 3 to facilitate connection with external circuitry.

[0102] Step S4 also includes the following steps:

[0103] A5. Prepare port pads on the surface of the lower insulating layer 521;

[0104] A6. A second metallized via 522 is formed between the lower insulating layer 521 and the port pad.

[0105] In some embodiments, the upper conductive line 510 and the lower conductive line 520 may be a metal conductive layer, ITO, or a metal mesh.

[0106] Optionally, the upper insulating layer 511 can be made of a transparent material, and the upper conductive line 510 can also be transparent, for example, by using a transparent material or controlling its line width and thickness to allow light to pass through. This allows the light from the LED chip 1 to be reliably emitted to the outside and observed by the human eye. The package 3 can be made of a transparent or opaque material. When made of an opaque material, crosstalk between light rays can be reduced. When made of a transparent material, the entire LED display array is transparent, allowing for a transparent screen and double-sided display.

[0107] In some embodiments, as shown in Figure 1 and Figure 2As shown, each control chip 2 is equipped with three monochrome LED groups, and the LED chips 1 contained in the three monochrome LED groups corresponding to the same control chip 2 emit different colors. For example, the three monochrome LED groups may contain a first-color LED chip, a second-color LED chip, and a third-color LED chip, respectively. The first-color LED chip, the second-color LED chip, and the third-color LED chip emit different colors, for example, one emits red light, one emits green light, and one emits blue light. The three monochrome LED groups are connected to different port electrodes 20 of the control chip 2 so that they can be driven to emit light independently. In this way, by mixing colors, the light-emitting unit 7 can emit more colors of light.

[0108] In some embodiments, in step S2, the LED chip 1 is placed on the first surface 60 of the substrate 6 using a conventional point-to-point mass transfer method, such as... Figure 17 As shown, optionally, the first surface 60 of the substrate 6 has a pre-defined target area 61 corresponding to the position of the control chip 2. The approximate area of ​​the target area 61 is shown in the figure with a double-dotted line frame. When transferring the LED chip 1, it is simply moved to the target area 61. When the light-emitting unit 7 has three monochromatic LED groups, LED chips 1 of different emitting colors can be moved to the corresponding target areas 61 in stages. For example, the target area 61 can be a first-color target area 61a, a second-color target area 61b, and a third-color target area 61c according to the emitting color of the LED chip 1 it carries. The first-color LED chip can be moved to the first-color target area 61a, the second-color LED chip can be moved to the second-color target area, and the third-color LED chip can be moved to the third-color target area in stages.

[0109] Through point-to-point mass transfer (such as nano-stamp handling), each LED chip 1 has high positional accuracy and its orientation is basically consistent.

[0110] like Figure 2 As shown, in some embodiments, in step S2, when placing multiple LED chips 1 on the first surface 60 of the substrate 6, multiple LED chips 1 of the same emission color are randomly distributed in the same target area 61 to form a monochromatic LED group composed of multiple LED chips 1 of the same emission color. It is understood that the position and orientation (e.g., electrode orientation) of the randomly distributed LED chips 1 are random. Therefore, the second electrode 11 of the LED chip 1 may or may not be in contact with the first surface 60. LED chips 1 whose second electrode 11 is in contact with the first surface 60 are referred to as effective LED chips 1a, and LED chips 1 whose second electrode 11 is not in contact with the first surface 60 are referred to as ineffective LED chips 1b. Figure 18The diagram shows the possible orientations of several LED chips 1 when they are randomly distributed. LED chips 1 that are in contact with the target area 61 by the second electrode 11 are called effective LED chips 1a because they can be driven to emit light normally. The other LED chips 1 cannot be driven to emit light normally and are called ineffective LED chips 1b.

[0111] It should be noted that the target area 61 is a virtual area defined by the user (for example, it may exist in computer software), and a target area 61 with clear boundaries may not necessarily exist on the actual product. In addition, the order in which the LED chip 1 and the control chip 2 are placed is not limited. For example, the control chip 2 can be placed first, followed by the LED chip 1, or vice versa, or they can be placed simultaneously.

[0112] It is understandable that although the ineffective LED chip 1b cannot be driven to emit light, as long as there is one emitting LED chip 1 in the monochrome LED group, the monochrome LED group can achieve the function of emitting light. Furthermore, under constant current source driving conditions, when the forward conduction voltage (Vf) of multiple parallel LED chips is similar, the total current output by the constant current source is approximately evenly distributed among the LED chips. Since the total current is constant, the total luminous power and overall brightness remain unchanged regardless of the number of parallel LED chips. In other words, even if the number of effective LED chips 1a in the monochrome LED group is different, as long as the monochrome LED group is driven by a constant current source, the luminous brightness of the monochrome LED group can be nearly uniform. Of course, more accurate uniformity can be further optimized through algorithms. The more emitting LED chips 1 there are in the monochrome LED group, the more uniform the brightness of the pixels corresponding to that monochrome LED group will be.

[0113] Understandably, in the case of random distribution, a monochrome LED group usually has a large number of effective LED chips 1a, such as two, three or more effective LED chips 1a (the effective LED chips 1a are usually more when using point-to-point mass transfer). Therefore, even if there are damaged LED chips 1, the monochrome LED group can still emit light normally, which greatly reduces the reliability requirements of LED chips 1, increases the process fault tolerance, and makes the LED display array more reliable in use.

[0114] Understandably, by randomly distributing the LED chips 1 in the target area 61, the positional requirements for each individual LED chip 1 can be greatly reduced, avoiding the high precision requirements of traditional mass transfer. This eliminates the need for expensive, high-precision mass transfer equipment, significantly improving production efficiency and reducing production costs. Furthermore, invalid LED chips 1b can be retained in the target area 61 without requiring processing, greatly simplifying the process.

[0115] LED chip 1 can be a Micro LED chip or a Mini LED chip. When randomly distributed, because there is no need for point-to-point mass transfer, the size of LED chip 1 can be made very small, and the cost of a single LED chip 1 is lower. A large number of LED chips 1 can be randomly distributed in a small target area 61, such as a dozen, dozens, hundreds or even more LED chips 1, thereby improving the reliability and uniformity of light emission.

[0116] It is understandable that, given a large number of randomly distributed LED chips 1, it is almost inevitable that there will be a valid LED chip 1a in the target area 61. In addition, the number of valid LED chips 1a in the target area 61 can be further increased through various means.

[0117] In some embodiments, the center of gravity of the LED chip 1 is set close to the second electrode 11. This makes the LED chip 1 more stable when its second electrode 11 is facing downwards, especially when randomly distributed across at least the target region 61. Therefore, the probability of the second electrode 11 of the LED chip 1 facing downwards is significantly increased. As a possible example, refer to... Figure 19 The LED chip 1 includes a metal mass block 110 connected to its second electrode 11. The center of gravity of the LED chip 1 is changed by adding the metal mass block 110. As a feasible example, such as... Figure 20 As shown, the second electrode 11 of the LED chip 1 is widened and / or thickened to bring its center of gravity closer to the second electrode 11. As a possible example, such as... Figure 21 As shown, the cross-sectional area of ​​the end where the second electrode 11 of the LED chip 1 is located is larger than the cross-sectional area of ​​the end where the first electrode 10 is located, and its overall shape is smaller at the top and larger at the bottom, so that its center of gravity is close to the second electrode 11. It can be understood that the above examples can be used in combination to further ensure the effect.

[0118] In some embodiments, the LED chip 1 is in the shape of a cuboid or a cube, and includes at least two sets of electrode pairs. As described above, each set of electrode pairs includes a first electrode 10 and a second electrode 11 located on opposite surfaces of the LED chip 1, respectively. The two second electrodes 11 of the two sets of electrode pairs are located on two adjacent surfaces of the LED chip 1, respectively. Similarly, the two second electrodes 11 of the two sets of electrode pairs are also located on two adjacent surfaces of the LED chip 1, respectively. Optionally, the two first electrodes 10 of the two sets of electrode pairs are connected to each other and are integral, for example, extending from one surface of the LED chip 1 to another surface. The two second electrodes 11 of the two sets of electrode pairs are connected to each other and are integral, for example, extending from one surface of the LED chip 1 to another surface. Figure 22 and Figure 23A schematic diagram is shown when two sets of electrodes are provided on the LED chip 1. Since the number of second electrodes 11 on the surface of the LED chip 1 is increased, the probability of the second electrodes 11 of the LED chip 1 contacting the target area 61 can be greatly increased. Specifically, assuming that the probability of each side of the LED chip 1 facing down is the same, the probability of having a downward-facing second electrode 11 is one-sixth and one-third when the second electrodes 11 are provided on only one side and on both sides, respectively.

[0119] In some embodiments, such as Figure 24 As shown, the LED chip 1 includes three sets of electrode pairs. The three second electrodes 11 of the three sets of electrode pairs are located on three adjacent surfaces of the LED chip 1, and the three first electrodes 10 of the three sets of electrode pairs are located on the other three adjacent surfaces of the LED chip 1. Assuming that the probability of each surface of the LED chip 1 facing down is the same, when three sets of electrode pairs are set, the probability of the second electrode 11 of the LED chip 1 facing down is half, which greatly increases the probability. When the number of LED chips 1 randomly distributed in the target area 61 is 10, the probability of having a valid LED chip 1a can be greater than 99.9%. If combined with the aforementioned center of gravity adjustment or other methods, the probability can be further improved. For example, the center of gravity of the LED chip 1 can be set close to one of the second electrodes 11, or it can be set close to the connection position of two or three second electrodes 11. Optionally, the three first electrodes 10 of the three sets of electrode pairs are interconnected and are integral, for example, extending from one surface of the LED chip 1 to the other two surfaces. The three second electrodes 11 of the three sets of electrode pairs are interconnected and are integral, for example, extending from one surface of the LED chip 1 to the other two surfaces.

[0120] Optionally, the surface of the second electrode 11 is provided with conductive adhesive, so that when the second electrode 11 comes into contact with the target area 61, it is less likely to flip or roll, thereby improving the reliability of the contact between the second electrode 11 and the target area 61.

[0121] Understandably, the probability of the second electrode 11 being on the bottom can also be increased in other ways. For example, the probability can be increased by applying an external magnetic field: a small amount of magnetic metal can be deposited on the side of the second electrode 11 or unidirectional magnetic particles can be adhered, and a magnetic field can be applied below the substrate 6 to align the LED chip 1 in the correct orientation. Alternatively, the probability can be increased by applying an external sound field or electric field.

[0122] Optionally, each group of monochromatic LEDs contains no fewer than 8 LED chips 1 to increase the probability of a valid LED chip 1a appearing.

[0123] In step S2, multiple LED chips 1 with the same emitting color are randomly scattered on the same target area 61, which can be achieved in various ways.

[0124] In some embodiments, multiple LED chips 1 of the same emitting color are directly poured onto the target area 61. Specifically, a large number of LED chips 1 can be placed in a storage container, and then the LED chips 1 are released to the target area 61 through the storage container. Since the posture of the LED chips 1 in the storage container is random, and the randomness of the LED chips 1 is also increased during the falling process, the LED chips 1 are also randomly distributed after falling into the target area 61. Specifically, the position and posture (e.g., the position of the electrodes) of the LED chips 1 are diverse.

[0125] In other embodiments, randomly distributing multiple LED chips 1 of the same emission color on the same target area 61 includes the following steps:

[0126] A1. Place multiple LED chips 1 of the same emitting color in a liquid to form an LED slurry.

[0127] A2. Transfer the LED paste to the target area 61.

[0128] It is understandable that the more uniformly the LED chip 1 is distributed in the liquid, the more uniformly the LED chip 1 will be distributed in the target area 61 after it is transferred to the target area 61. When the volume of LED paste carried by each target area 61 is similar, the number of LED chips 1 contained in each target area 61 is also relatively similar, which is conducive to increasing the uniformity of light emission.

[0129] Since the orientation of LED chip 1 in the liquid is random, its position and orientation in the target area 61 are also random after the LED slurry is transferred to the target area 61, resulting in diverse electrode positions for LED chip 1. It is understandable that by controlling the concentration of LED chip 1 (i.e., the number of LED chips 1 contained in a unit volume of slurry), the number of LED chips 1 that may exist in the target area 61 can be controlled, thereby controlling the probability of the presence of a valid LED chip 1a.

[0130] The liquid can be deionized water, an aqueous solution with added surfactants, an organic solvent, or an inert liquid with a density higher than water. Understandably, the liquid does not dissolve, expand, encapsulate, or bond materials, nor does it undergo electrochemical reactions with metals.

[0131] It is understandable that the liquid on substrate 6 can be removed by methods such as solvent evaporation, solution annealing, and capillary drainage. For liquids that can be cured, they can also be cured and retained.

[0132] Optionally, in step A2, the LED paste is transferred to the target area 61 by means of screen printing, embossing, spraying, or printing. In screen printing, the LED paste is embossed onto the target area 61 using a screen mask. In embossing, the LED paste is first applied to an open stencil and then transferred to the target area. In spraying, the LED paste is sprayed onto the surface of the target area. Printing can be, for example, inkjet printing or dispensing printing.

[0133] It is understandable that an LED display array includes a large number of target areas, and LED chips 1 can be randomly distributed in different target areas 61 in stages, or LED chips 1 can be randomly distributed simultaneously in all target areas 61 used to carry LED chips 1 of the same emission color. When the LED display array includes target areas carrying LED chips of different emission colors, LED chips 1 of different colors can be distributed to the corresponding target areas in stages.

[0134] For example, by means of screen printing or inkjet printing, the LED chips 1 of the corresponding light-emitting colors are randomly distributed in three stages in the first color target area 61a, the second color target area 61b and the third color target area 61c. Specifically, the first color LED chips 1 are printed on all the first color target areas 61a first, then the second color LED chips 1 are printed on all the second color target areas 61b, and then the third color LED chips 1 are printed on all the third color target areas 61c (of course, the order can be adjusted).

[0135] For example, when randomly scattering a certain color LED chip 1 by tilting, an auxiliary plate can be set up to block the target area that does not correspond to that color LED chip 1. The auxiliary plate can be set up to only expose the corresponding target area, so that the LED chip 1 can be reliably scattered in the target area to be scattered. For example, such as... Figure 25 As shown, when the first-color LED chip 1 is distributed in the first-color target area 61a, the first-color target area 61a can be exposed through the auxiliary plate, while other areas are blocked (the blocked target areas are indicated by dashed lines in the figure). In this way, when the first-color LED chip 1 is tilted, it will not be mistakenly located in the second-color target area 61b and the third-color target area 61c. A similar method can be used when tilting other-color LED chips 1.

[0136] This invention also proposes a method for fabricating an LED display array (a second method for fabricating an LED display array), which includes the following steps:

[0137] S1. Provide a substrate 6, an LED chip 1 and a control chip 2, wherein the LED chip 1 includes an electrode pair, and the electrode pair includes a first electrode 10 and a second electrode 11 located on opposite sides of the LED chip 1;

[0138] S2. A plurality of control chips 2 are placed on the first surface 60 of the substrate 6, with the port electrodes 20 of the control chips 2 in contact with the first surface 60. A plurality of LED chips 1 are placed on the first surface 60 of the substrate 6 to form a monochrome LED group composed of a plurality of LED chips 1 with the same light emission color. Each control chip 2 corresponds to at least one monochrome LED group. The control chip 2 and its corresponding monochrome LED group, as well as the plurality of control chips 2, are electrically connected through the substrate 6.

[0139] S3. An encapsulation body 3 is provided on the outside of the substrate 6 to cover all the control chips 2 and the LED chips 1;

[0140] S4. An upper wiring layer 51 is prepared on the upper surface of the package 3.

[0141] In the second fabrication method, the substrate 6 may include the lower wiring layer 52 described above or have the same structure as the lower wiring layer 52 described above, which includes a lower insulating layer 521 and a lower conductive line 520. That is, the lower conductive line 520 has been pre-fabricated on the substrate 6 (or the lower wiring layer 52 described above has been pre-fabricated). When the control chip 2 and the LED chip 1 are placed on the substrate 6, they are placed at the positions corresponding to the lower conductive line 520 to achieve electrical contact. Reliable connection with the lower conductive line 520 can be achieved by soldering or other methods, without the need to fabricate the lower wiring layer 52 separately, which is more convenient.

[0142] For further details regarding the second preparation method, please refer to the above text.

[0143] The present invention also proposes an LED display array, which can be fabricated using the LED display array fabrication method described above. The structure of the LED display array has been described in detail above, and its main parts are briefly described below.

[0144] In some embodiments, as shown in Figure 1, Figure 2 , Figure 5 and Figure 11 As shown, the LED display array includes multiple monochrome LED groups, multiple control chips 2, a package 3, an upper wiring layer 51, and a lower wiring layer 52.

[0145] Each group of monochrome LEDs includes multiple LED chips 1 that emit the same color. Each LED chip 1 includes a first electrode 10 and a second electrode 11 located on opposite sides of it. One of the first electrode 10 and the second electrode 11 is a positive electrode and the other is a negative electrode.

[0146] The package 3 covers the control chip 2 and all the LED chips 1.

[0147] The upper wiring layer 51 and the lower wiring layer 52 are respectively disposed on opposite surfaces of the package body 3. Specifically, the upper wiring layer 51 is disposed on the upper surface of the package body 3, and the lower wiring layer 52 is disposed on the lower surface of the package body 3. The control chip 2 and the corresponding monochrome LED group, as well as multiple control chips 2, are electrically connected through the lower wiring layer 52. The control chip 2 and the corresponding monochrome LED group constitute a light-emitting unit 7.

[0148] In some embodiments, such as Figure 17 As shown, the position of LED chip 1 is regular and its orientation is fixed. For example, LED chip 1 can be moved to the corresponding target area using a traditional point-to-point mass transfer method.

[0149] In some embodiments, such as Figure 2 As shown, the position and orientation of LED chip 1 are random to reduce the requirements for handling accuracy of LED chip 1. For example, a monochromatic LED group can be formed by random scattering as described above. LED chip 1 with the second electrode 11 and the port electrode 20 located on the same plane is called effective LED chip 1a, and LED chip 1 with the second electrode 11 not located on the same plane as the port electrode 20 is called ineffective LED chip 1b. The control chip 2 is electrically connected to the second electrode 11 of the effective LED chip 1a of the corresponding monochromatic LED group.

[0150] In some embodiments, such as Figure 5 and Figure 11 As shown, the upper wiring layer 51 includes an upper conductive line 510 and an upper insulating layer 511 covering the upper conductive line 510. The lower wiring layer 52 includes a lower conductive line 520 and a lower insulating layer 521 covering the lower conductive line 520. The control chip 2 of the light-emitting unit 7 and the monochrome LED group, as well as the control chips 2 of different light-emitting units 7, are electrically connected through the lower conductive line 520. Each monochrome LED group is connected to the upper conductive line 510. Multiple control chips 2 are connected in series through the lower conductive line 520 to transmit digital signals.

[0151] As a feasible example, such as Figures 13 to 15As shown, the lower conductive line 520 includes a power supply line 5200, a ground line 5201, a signal line 5202, and a connecting line 5203. The control chip 2 is electrically connected to the power supply line 5200 and the ground line 5201 to enable it to function properly. Specifically, the control chip 2 includes a voltage port electrode 202, a ground port electrode 203, a first signal transmission electrode 200, a second signal transmission electrode 201, and a control electrode 204. The voltage port electrode 202 is connected to the power supply line 5200, and the ground port electrode 203 is connected to the ground line 5201. The first signal transmission electrode 200 of the preceding control chip 2 and the second signal transmission electrode 201 of the following control chip 2 are electrically connected via the signal line 5202. The control electrode 204 and the corresponding monochrome LED group are connected via the connecting line 5203.

[0152] The upper conductive line 510 is connected to the power supply line 5200 or the ground line 5201 through the first metallized via 50 passing through the package 3.

[0153] In some embodiments, such as Figure 15 and Figure 16 As shown, the lower wiring layer 52 also includes multiple port pads exposed outside the LED display array, enabling the LED display array to be easily connected to external circuits, such as for power input, grounding, and input control signals. The port pads are all located on the surface of the lower insulating layer 521 away from the package 3 for easy wiring. Optionally, the lower wiring layer 52 includes a power supply port pad 523, a signal port pad 525, and a ground port pad 524. The power supply port pad 523 is connected to the power supply line 5200, the signal port pad 525 is connected to the signal line 5202 connected to the first signal transmission electrode 200 of the first control chip 2, and the ground port pad 524 is connected to the ground line 5201. Since the port pads and the lower conductive lines 520 are separated by the lower insulating layer 521, they can be connected through a second metallized via 522 passing through the lower insulating layer 521.

[0154] It is understood that other embodiments or structural details of LED display arrays can be found in the description above, and will not be repeated here.

[0155] It is understood that the location, size, and quantity of target areas, LED chips, and other structures in the accompanying drawings of this specification are illustrative and do not represent the actual form of the product.

[0156] It should be noted that, in the absence of conflict, the various embodiments described herein can be combined with each other to obtain more implementation schemes.

[0157] The above are merely specific embodiments of the present invention, and any improvements made based on the concept of the present invention shall be considered within the scope of protection of the present invention.

Claims

1. A method for fabricating an LED display array, characterized in that, Includes the following steps: S1. Provide a substrate (6), an LED chip (1) and a control chip (2), wherein the LED chip (1) includes an electrode pair, the electrode pair including a first electrode (10) and a second electrode (11) located on opposite sides of the LED chip (1). S2. Place multiple control chips (2) on the first surface (60) of the substrate (6), with the port electrode (20) of the control chip (2) in contact with the first surface (60), and place multiple LED chips (1) on the first surface (60) of the substrate (6) to form a monochrome LED group composed of multiple LED chips (1) with the same light emission color, with each control chip (2) corresponding to at least one monochrome LED group; S3. An encapsulation (3) covering all the control chips (2) and the LED chips (1) is provided on the outside of the substrate (6). S4. An upper wiring layer (51) and a lower wiring layer (52) are respectively prepared on the upper and lower surfaces of the package (3). The control chip (2) and the corresponding monochrome LED group and the multiple control chips (2) are electrically connected through the lower wiring layer (52).

2. The method for fabricating an LED display array as described in claim 1, characterized in that, In step S2, when multiple LED chips (1) are placed on the first surface (60) of the substrate (6), multiple LED chips (1) with the same emission color are randomly scattered in the same target area (61) to form a monochromatic LED group composed of multiple LED chips (1) with the same emission color. LED chips (1) whose second electrode (11) is in contact with the first surface (60) are called effective LED chips (1a), and LED chips (1) whose second electrode (11) is not in contact with the first surface (60) are called ineffective LED chips (1b).

3. The method for fabricating an LED display array as described in claim 1, characterized in that, In step S2, each control chip (2) is provided with three monochrome LED groups, and the LED chips (1) contained in the three monochrome LED groups corresponding to the same control chip (2) have different light emission colors.

4. The method for fabricating an LED display array as described in claim 1, characterized in that, In step S2, each monochrome LED group contains no less than 8 LED chips (1).

5. The method for preparing an LED display array as described in claim 2, characterized in that, In step S2, randomly scattering multiple LED chips (1) with the same emitting color in the same target area (61) includes: pouring the multiple LED chips (1) with the same emitting color into the target area (61).

6. The method for fabricating an LED display array as described in claim 1, characterized in that, In step S2, randomly distributing multiple LED chips (1) of the same emitting color in the same target area (61) includes: Multiple LED chips (1) with the same emitting color are placed in a liquid to form an LED paste; The LED paste is transferred to the target area (61).

7. The method for fabricating an LED display array as described in claim 6, characterized in that, The LED paste is transferred to the target area (61) by means of screen printing, embossing, spraying or printing.

8. The method for fabricating an LED display array as described in claim 1, characterized in that, The upper wiring layer (51) includes an upper conductive line (510) and an upper insulating layer (511), and the lower wiring layer (52) includes a lower conductive line (520) and a lower insulating layer (521). In step S4, the preparation of the upper wiring layer (51) and the lower wiring layer (52) on the upper and lower surfaces of the package (3) respectively includes the following steps: Remove the substrate (6) to expose the second electrode (11) of the effective LED chip (1a) and the port electrode (20) of the control chip (2). Upper conductive lines (510) and lower conductive lines (520) are respectively prepared on the upper and lower surfaces of the package (3), and the lower surface is the surface of the package (3) that exposes the port electrodes (20) of the control chip (2); A first metallized via (50) is prepared to connect the upper conductive line (510) and the lower conductive line (520). An upper insulating layer (511) and a lower insulating layer (521) are respectively prepared on the upper and lower surfaces of the package (3), and the upper insulating layer (511) covers the surface of the upper conductive line (510), and the lower insulating layer (521) covers the surface of the lower conductive line (520).

9. The method for fabricating an LED display array as described in claim 8, characterized in that, The lower conductive line (520) includes a power supply line (5200), a ground line (5201), a signal line (5202), and a connecting line (5203). The control chip (2) is electrically connected to the power supply line (5200) and the ground line (5201). Multiple control chips (2) are connected in series through the signal line (5202) to transmit digital signals. The second electrode (11) of the effective LED chip (1a) and the control chip (2) are connected through the connecting line (5203). The first electrode (10) of the effective LED chip (1a) is connected to the power supply line (5200) or the ground line (5201) through the upper conductive line (510) and the first metallized via (50).

10. The method for preparing an LED display array as described in claim 8, characterized in that, In step S4, before preparing the upper conductive line (510), the following step is also included: thinning the upper surface of the package (3) to expose the first electrode (10) of the LED chip (1).

11. The method for manufacturing an LED display array according to any one of claims 1 to 10, characterized in that, The center of gravity of the LED chip (1) is close to the second electrode (11). The LED chip (1) includes a metal mass block connected to its second electrode (11); and / or, The cross-sectional area of ​​the end where the second electrode (11) of the LED chip (1) is located is greater than the cross-sectional area of ​​the end where the first electrode (10) is located.

12. The method for manufacturing an LED display array according to any one of claims 1 to 10, characterized in that, The LED chip (1) is in the shape of a cuboid or a cube; The LED chip (1) includes two sets of electrode pairs, and the second electrodes (11) of the two sets of electrode pairs are located on two adjacent surfaces of the LED chip (1); or, The LED chip (1) includes three sets of electrode pairs, and the second electrodes (11) of the three sets of electrode pairs are located on three adjacent surfaces of the LED chip (1).

13. An LED display array, characterized in that, include: Multiple monochrome LED groups, each monochrome LED group includes multiple LED chips (1) with the same emitting color, each LED chip (1) includes an electrode pair, the electrode pair including a first electrode (10) and a second electrode (11) located on opposite sides of the LED chip (1). Multiple control chips (2), each control chip (2) includes multiple port electrodes (20), and each control chip (2) is provided with at least one monochrome LED group; The package (3) covers the outside of the control chip (2) and all the LED chips (1); An upper wiring layer (51) is disposed on the upper surface of the package (3); as well as, The lower wiring layer (52) is disposed on the lower surface of the package (3), and the control chip (2) and the corresponding monochrome LED group, as well as the multiple control chips (2), are electrically connected through the lower wiring layer (52).

14. The LED display array as described in claim 13, characterized in that, The position and orientation of the LED chip (1) of the monochrome LED group are random. The LED chip (1) whose second electrode (11) is on the same plane as the port electrode (20) is called a valid LED chip (1a). The LED chip (1) whose second electrode (11) is not on the same plane as the port electrode (20) is called an invalid LED chip (1b). The control chip (2) and the second electrode (11) of the valid LED chip (1a) of the corresponding monochrome LED group are electrically connected.

15. The LED display array as described in claim 13, characterized in that, Multiple control chips (2) are connected in series to transmit digital signals.

16. The LED display array as described in claim 15, characterized in that, The multiple port electrodes (20) of the control chip (2) include a first signal transmission electrode (200) and a second signal transmission electrode (201) for signal transmission, and the first signal transmission electrode (200) of the former control chip (2) and the second signal transmission electrode (201) of the latter control chip (2) are electrically connected.

17. The LED display array as described in claim 16, characterized in that, The lower wiring layer (52) includes a lower conductive line (520) and a lower insulating layer (521) covering the lower conductive line (520). The lower conductive line (520) includes a power supply line (5200), a ground line (5201), a signal line (5202), and a connecting line (5203). The first signal transmission electrode (200) of the former control chip (2) and the second signal transmission electrode (201) of the latter control chip (2) are connected by the signal line (5202); The control chip (2) is connected to the power supply line (5200) and the ground line (5201); The upper wiring layer (51) includes an upper conductive line (510) electrically connected to the first electrode (10) of the active LED chip (1a) and an upper insulating layer (511) covering the upper conductive line (510). The upper conductive line (510) is connected to the power supply line (5200) or the ground line (5201) through a first metallized via (50) passing through the package (3).

18. The LED display array as described in claim 17, characterized in that, The lower wiring layer (52) includes a power supply port pad (523), a ground port pad (524), and a signal port pad (525) exposed on the lower insulating layer (521). The power supply port pad (523) is electrically connected to the power supply line (5200) for connecting to an external power source. The ground port pad (524) is electrically connected to the ground line (5201). The signal port pad (525) is electrically connected to the first signal transmission electrode (200) of the first control chip (2) for inputting control signals.

19. The LED display array as described in any one of claims 13 to 18, characterized in that, Each of the control chips (2) is provided with three monochrome LED groups, and the LED chips (1) of the three monochrome LED groups have different light emission colors.

Images