Display lamp panel, display equipment and preparation method

Abstract

The invention discloses a display lamp panel, display equipment and a preparation method. The display lamp panel comprises a circuit substrate, a micro light-emitting diode array, an adhesive layer and a semi-permeable membrane structure, the micro light-emitting diode arrays and the adhesive layer are arranged on the circuit substrate, the adhesive layer is filled between the micro light-emitting diode arrays, the semi-permeable membrane structure covers and is connected to the micro light-emitting diode arrays and the adhesive layer, and each micro light-emitting diode array comprises a plurality of micro light-emitting diodes; each miniature light-emitting diode is provided with a plurality of electrodes, the plurality of electrodes are connected with the plurality of substrate bonding pads in a one-to-one correspondence manner, the substrate bonding pads are arranged on the circuit substrate, the plurality of substrate bonding pads are provided with respective corresponding via holes and conductive hole rings, and the conductive hole rings, the via holes and the electrodes are coaxially arranged. And the micro light-emitting diodes are electrically connected with the circuit substrate in a wiring manner. The number of pixels per inch in micro light emitting diode display can be increased under the condition that the contrast ratio and the brightness are considered.

Description

Technical Field

[0001] The present application relates to the field of screen display technology, and in particular to a display light board, a display device and a preparation method thereof. Background Art

[0002] Micro LED (micro light emitting diode) technology, namely LED (micro light emitting diode) miniaturization and matrix technology, refers to a high-density, tiny-sized LED array integrated on a driving substrate. For example, each pixel of an LED display can be addressed and driven and lit individually. It can be regarded as a miniature version of a commercial LED display, reducing the pixel distance from millimeters to micrometers. Micro LED is a new generation of display technology with technical characteristics such as higher brightness, low power consumption, high PPI (pixels per inch), transparency, and flexibility. Therefore, it can be used in wearable displays and large-screen displays with high performance and process requirements.

[0003] In existing designs, due to the tiny size of Micro LED chips and the complex packaging, the existing process precision cannot guarantee the integration of more LED chips in a limited area while maintaining the stable connection of each chip; in the process of pursuing high PPI, the trade-off between brightness and contrast makes it difficult to ensure excellent display effects at the same time. Reducing the transmittance of the sealing material will increase the contrast but lose brightness, while filling with black glue may increase costs and be limited by process precision. Therefore, the existing technology cannot achieve the goal of high PPI in Micro LED display.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The main purpose of the present application is to provide a display light board, a display device and a preparation method, aiming to solve the problem in the prior art that the micro-light emitting diode chip is small in size and complex in packaging, resulting in a low number of pixels per inch in the micro-light emitting diode display while taking into account both contrast and brightness.

[0006] A first aspect of an embodiment of the present application provides a display light board, which includes a circuit substrate, a micro-light emitting diode array, a glue layer and a semi-permeable membrane structure; the micro-light emitting diode array and the glue layer are arranged on the circuit substrate, and the glue layer is filled between the micro-light emitting diode array, the semi-permeable membrane structure is covered and connected to the micro-light emitting diode array and the glue layer, and the micro-light emitting diode array includes a plurality of micro-light emitting diodes; each of the micro-light emitting diodes is provided with a plurality of electrodes, and the plurality of electrodes are connected one-to-one with a plurality of substrate pads, the substrate pads are arranged on the circuit substrate, and the plurality of substrate pads are provided with respective corresponding vias and conductive hole rings, and the conductive hole rings, the vias and the electrodes are coaxially arranged to electrically connect the micro-light emitting diodes with the circuit substrate for wiring.

[0007] Optionally, in one embodiment of the present application, in the micro-light emitting diode array, a solder resist ink layer is provided between each two adjacent columns of the micro-light emitting diodes, and the solder resist ink layer is connected to the circuit substrate.

[0008] Optionally, in one embodiment of the present application, the cross-section of the solder resist ink layer is arched, and the solder resist ink layer is used for guiding when forming the adhesive layer.

[0009] Optionally, in one embodiment of the present application, the semipermeable membrane structure is a semipermeable membrane that is bonded at room temperature or cured by ultraviolet light, the semipermeable membrane is tightly bonded to the adhesive layer, and the semipermeable membrane is used to protect the micro light emitting diode array.

[0010] Optionally, in one embodiment of the present application, the circuit substrate includes a first circuit board and a second circuit board which are stacked, the micro light emitting diode array, the plurality of substrate pads and the solder resist ink layer are respectively connected to the second circuit board, the first circuit board and the second circuit board are respectively provided with a plurality of connecting holes, and the corresponding plurality of connecting holes on the first circuit board and the second circuit board are connected one-to-one with the plurality of vias.

[0011] A second aspect of an embodiment of the present application provides a display device, wherein the display device includes a display light board as described in any one of the above solutions.

[0012] A third aspect of an embodiment of the present application provides a method for preparing a display light board, wherein the preparation method is used to prepare a display light board as described in any of the above schemes, and the preparation method of the display light board includes: preparing a circuit substrate and a plurality of micro-light emitting diodes, wherein the micro-light emitting diodes are provided with a plurality of electrodes, the circuit substrate is provided with a plurality of substrate pads, the plurality of substrate pads are provided with respective corresponding vias and conductive hole rings, and the conductive hole rings are coaxially arranged with the vias; arranging the plurality of micro-light emitting diodes on the circuit substrate to form a micro-light emitting diode array, so that the plurality of electrodes are connected to the plurality of substrate pads in a one-to-one correspondence, and the conductive hole rings, the vias and the electrodes are coaxially arranged; filling the space between the micro-light emitting diode arrays with filling material on the circuit substrate to form a light board with a glue layer; and laminating the glue layer of the light board and the micro-light emitting diode array with a semi-permeable membrane structure to obtain a display light board.

[0013] Optionally, in one embodiment of the present application, the filling material is used to fill the space between the micro-light emitting diode arrays on the circuit substrate to form a lamp board with a glue layer, specifically comprising: setting a vertical strip solder resist ink layer between every two columns of the micro-light emitting diodes in the micro-light emitting diode array to form a lamp board to be injected with glue; using a multi-head needle tube to inject the filling material into the lamp board to be injected with glue along the solder resist ink layer to obtain a lamp board with a glue layer.

[0014] Optionally, in one embodiment of the present application, the filling material is liquid black glue; the filling material is injected into the lamp board to be injected with glue along the solder resist ink layer using a multi-head needle tube to obtain a lamp board with a glue layer, specifically comprising: installing the lamp board to be injected with glue on a rotating bracket so that the lamp board to be injected with glue is inclined; using a multi-head needle tube to inject liquid black glue along the direction of the solder resist ink layer that penetrates the lamp board to be injected with glue, so that the black glue flows downward along the direction of the solder resist ink layer to cover the gaps between the plurality of micro-light-emitting diodes; rotating the lamp board to be injected with glue at a uniform speed along the plane where the rotating bracket is located, so that the black glue flows along the arched surface of the black ink to the horizontal gaps between the micro-light-emitting diodes, and solidifies to form a glue layer, so as to obtain a lamp board with a glue layer.

[0015] Optionally, in one embodiment of the present application, the semipermeable membrane structure is a semipermeable membrane; the semipermeable membrane structure is used to coat the adhesive layer of the light board and the micro-light emitting diode array to obtain a display light board, specifically: at room temperature, the semipermeable membrane is rolled and bonded to the surface of the adhesive layer and the micro-light emitting diode array to obtain a display light board; or under ultraviolet irradiation, the semipermeable membrane is rolled and bonded to the surface of the adhesive layer and the micro-light emitting diode array to obtain a display light board.

[0016] Beneficial effects: The present application provides a display light board, a display device and a preparation method. The display light board can effectively utilize the space inside the pad for wiring by pulling the via and the conductive hole ring into the substrate pad, avoiding the space occupied by separately setting the via next to the chip, and improving the signal transmission quality and welding quality, thereby increasing the number of pixels per inch in the micro light emitting diode display while taking into account the contrast and brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A cross-sectional view showing a preferred embodiment of a light panel for this application;

[0019] Figure 2 A planar structural diagram of a micro-light emitting diode array in a preferred embodiment of a display light board of the present application;

[0020] Figure 3 For this application Figure 2 A schematic diagram of the structure enlargement at the center A;

[0021] Figure 4 A cross-sectional view of a preferred embodiment of the display light board of the present application after a solder resist ink layer is provided;

[0022] Figure 5 This is a cross-sectional view of a preferred embodiment of the display light board of the present application after the glue layer is formed;

[0023] Figure 6 A schematic diagram of the structure of installing the light board to be injected with glue on a rotating bracket for injection in a preferred implementation of the display light board of the present application;

[0024] Figure 7 It is a flow chart of a preferred embodiment of the method for preparing a display light board of the present application.

[0025] Description of reference numerals:

[0026] 100. Display light board;

[0027] 10. Circuit substrate; 20. Micro light emitting diode array; 30. Glue layer; 40. Semi-permeable membrane structure; 21. Micro light emitting diode; 211. Electrode; 22. Substrate pad; 23. Via hole; 24. Conductive hole ring; 25. Solder resist ink layer; 26. Solder.

[0028] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and effect of the present application clearer and more specific, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. The described embodiments are only possible technical implementations of the present application, not all possible implementations. Based on the embodiments in the present application, those skilled in the art can completely combine the embodiments of the present application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present application.

[0030] It should be noted that high PPI (pixels per inch) is an important indicator pursued by Micro LED technology. It means that more pixels can be displayed under the same screen size, thus providing more delicate and clear images. However, to achieve high PPI, more LED chips need to be integrated in a limited area, which puts extremely high demands on process precision and packaging technology.

[0031] In the related technology, the current Micro LED display and Mini LED direct display light board driver substrate adopts a multi-layer circuit board, via holes are set next to the LED pads to connect the lower circuit, and solder mask ink is set between the pads. The LED chip is bonded to the driver substrate through a transfer process, and a layer of encapsulation glue with a certain transmittance is molded on the LED chip side of the light board to protect the chip and conceal blemishes. This kind of sealing process reduces the transmittance of the sealing material in order to improve the display contrast, resulting in a large loss of brightness and a high temperature of the light board.

[0032] Another way is to fill the gap between LED chips with black ink printing or black glue film pressing and plasma slurry cleaning after the mass transfer process is completed to improve the contrast of the light board, and then press a layer of semi-transparent glue on top to protect the chip and conceal blemishes. This method can solve the contrast and brightness problems to a certain extent, but due to the small size of MicroLED chips, especially after the MiP (Micro LED in Package) package, the LED height-to-length ratio increases, the bottom pad layout is complex, and the process precision problem cannot complete the processing of light boards smaller than P0.5mm. In addition, it is expensive and has a low yield when processing products with specifications below P0.6.

[0033] That is, the process accuracy problem existing in the prior art is as follows: the size of the Micro LED chip is small, especially after being made into MiP (Micro LED in Package) package, the aspect ratio of the LED increases, and the bottom pad layout becomes complicated, which makes it difficult to ensure process accuracy and low yield when processing lamp boards with specifications less than P0.5mm. Due to the limitation of process accuracy, it is difficult for the prior art to ensure that each LED chip can be accurately and stably connected to the driving substrate while maintaining a high PPI. In the trade-off between brightness and contrast of the prior art: in order to improve the display contrast, the existing solution usually reduces the transmittance of the sealing material, but this will cause a large loss of brightness and an increase in the temperature of the lamp board; another solution is to fill the gap between the LED chips with black glue to improve the contrast, but this is also limited by process accuracy and may increase costs. The trade-off between brightness and contrast makes it difficult to simultaneously ensure excellent display effects while pursuing high PPI. That is, the promotion purpose of high PPI Micro LED display cannot be achieved according to the prior art solution.

[0034] The following is an introduction to the terms involved in the embodiments of the present application:

[0035] LED: micro light-emitting diode, a semiconductor device that can convert electrical energy into light energy, with a package size of about 2 to 6 mm;

[0036] Micro LED: Micro light-emitting diode, in which the size of the LED is greatly reduced and integrated on the driver substrate to form a high-density array, with a size of ≤50um;

[0037] Mini LED: Sub-micro light-emitting diode, similar to Micro LED, but larger in size, 50um<size≤300um; may have different technical characteristics, usually used for direct display;

[0038] Via hole: a metallized hole used to connect circuits on different layers in a multi-layer circuit board.

[0039] PPI (Pixels Per Inch): The number of pixels per inch, used to measure the resolution of display devices;

[0040] MiP (Micro LED in Package): Micro LED in package, refers to the technology of packaging Micro LED in a specific structure;

[0041] UV: Ultraviolet light, commonly used to cure materials such as glue or paint;

[0042] AR (Augmented Reality): Augmented reality is a technology that enhances or supplements the user's perception of the real world through computer-generated images and information.

[0043] VR (Virtual Reality): Virtual reality is a simulated environment generated by computer technology that users can interact with through devices (such as head-mounted displays).

[0044] MR (Mixed Reality): Mixed reality combines the technologies of AR and VR to combine virtual elements with the real world.

[0045] RGBC: Red, Green, Blue, and another color (which may be white or another color, depending on the application), used in display technology to produce full-color images.

[0046] The display light board, display device and preparation method of the embodiment of the present application are described below with reference to the accompanying drawings. In view of the problem that the micro-light emitting diode chip in the above-mentioned related art is small in size and complex in packaging, resulting in a low number of pixels per inch in the micro-light emitting diode display while taking into account both contrast and brightness, the present application provides a display light board. In this method, by pulling the vias and the conductive hole rings into the substrate pads, the space inside the pads can be effectively utilized for wiring, avoiding the space occupied by the vias separately set next to the chip, and improving the signal transmission quality and welding quality, thereby increasing the number of pixels per inch in the micro-light emitting diode display while taking into account both contrast and brightness. Thus, the technical problem that the micro-light emitting diode chip in the related art is small in size and complex in packaging, resulting in a low number of pixels per inch in the micro-light emitting diode display while taking into account both contrast and brightness is solved.

[0047] This application can achieve the performance requirements of high contrast and high brightness under high PPI and high resolution specifications, while reducing production costs and improving yield.

[0048] This application can be applied to a variety of display devices such as ultra-high-definition TVs, LED displays, AR / VR / MR displays, monitors, laptops, mobile phones, tablets, etc.

[0049] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0050] Figure 1The numbers in the brackets identify the mechanism to which the component belongs. For example, 21 (20) indicates that the micro-LED 21 belongs to the micro-LED array 20, and 211 belongs to the electrode of the micro-LED 21.

[0051] The display light board 100 described in the preferred embodiment of the present application is as follows: Figure 1 , Figure 2 and Figure 3 As shown, the display light board 100 includes a circuit substrate 10, a micro-LED array 20, a glue layer 30 and a semi-permeable membrane structure 40; the micro-LED array 20 and the glue layer 30 are arranged on the circuit substrate 10, and the glue layer 30 is filled between the micro-LED array 20, the semi-permeable membrane structure 40 is covered and connected to the micro-LED array 20 and the glue layer 30, the micro-LED array 20 includes a plurality of micro-LEDs 21; each of the micro-LEDs 21 is provided with a plurality of electrodes 211; a plurality of substrate pads 22 are arranged on the circuit substrate, and the plurality of substrate pads 22 correspond to the plurality of electrodes 211 in one-to-one position, and the plurality of substrate pads 22 are provided with respective corresponding vias 23 and conductive hole rings 24, and the substrate pads 22, the conductive hole ring 24, the vias 23 and the micro-LED electrodes 211 are coaxially arranged to electrically connect the micro-LEDs to the circuit substrate through wiring.

[0052] Specifically, the micro-LED 21 is provided with a special-shaped electrode, which is used to encapsulate the internal circuit wiring; each micro-LED 21 is connected to the circuit board pad through the electrode 211, and the pad is a specific area on the circuit board designed to solder the pins or electrodes of electronic components. It can be understood that the metal via 23 passes through the multi-layer structure of the circuit board at the position of the substrate pad 22 to connect the circuits between different layers. The conductive hole ring 24 is an annular conductive area surrounding the via 23, which ensures a reliable electrical connection between the via 23 and the substrate pad 22. The circular conductive hole ring 24 is slightly larger than the square substrate pad 22, but the conductive hole ring 24 and the substrate pad are on the same copper sheet. It should be noted that the vias and conductive hole rings in the conventional solution are not on the pad. This solution is because the space is limited due to the high ppi MicroLED display, so the vias and conductive hole rings are pulled into the pad.

[0053] The main function of the via 23 is to provide electrical connection between multiple layers of the circuit board, thereby realizing the wiring electrical connection between the chip and the circuit board. In the display light board, due to the extremely small pixel distance (micrometer level), the space of the circuit board is very limited. Therefore, the hole design needs to be very precise to ensure reliable electrical connection without occupying too much pad space. The introduction of the conductive hole ring 24 is to provide additional electrical connection area and strength within the limited pad space to ensure the reliability of the connection.

[0054] In a high-PPI Micro LED display panel, due to the small size and dense arrangement of Micro LED chips, the space on the circuit board becomes extremely limited. Traditional wiring methods may cause wiring difficulties or reduced wiring quality due to insufficient space. Based on this, the present application pulls the vias 23 and the hole rings into the four chip pads, which can effectively utilize the space inside the pads for wiring. This method avoids the space occupied by the vias 23 set separately next to the chip, thereby solving the space wiring problem.

[0055] The purpose of setting the via 23 and the conductive hole ring 24 on the substrate pad 22 is as follows: first, to ensure the stable transmission of the signal. By setting the via 23, a stable conductive channel can be established between the circuit boards of different layers to ensure the accurate transmission of the signal; second, to enhance the conductivity of the pad. The setting of the conductive hole ring 24 can further enhance the conductivity of the pad, reduce resistance and inductance, and improve the transmission efficiency of the signal; third, to keep the chip pad height consistent. When the four pads are all provided with vias 23, the height of the pads at the four positions of the chip can be ensured to be the same, which is conducive to the stable mounting and welding of the chip. Thus, the embodiment of the present application can achieve the following effects: improve the transmission quality of the signal. The stable conductive channel and enhanced conductive performance can ensure the accurate and fast transmission of the signal and reduce signal loss and interference; improve the welding quality. The consistency of the pad height and the setting of no solder mask ink can avoid the problem of poor welding caused by the chip riding on the ink, and improve the welding quality and reliability; optimize the wiring space. Pulling the via 23 and the hole ring into the pad can make full use of the limited space for wiring and optimize the layout and design of the circuit board.

[0056] That is, the present application can effectively solve the spatial wiring problem in high-PPI Micro LED display panels and improve the signal transmission quality and welding quality, thereby achieving the performance requirements of high contrast and high brightness under high PPI and high resolution specifications, while reducing production costs and improving yields.

[0057] Specifically, in the embodiment of the present application, the Micro LED display panel includes a circuit substrate 10, a Micro LED array (i.e., a micro light emitting diode array 20), black glue (i.e., a glue layer 30) and a semi-permeable membrane (i.e., a semi-permeable membrane structure 40). The circuit substrate 10 includes a multi-layer circuit board, a via 23, a conductive hole ring 24, a substrate pad 22 (corresponding to the position of the Micro LED pad), and a black solder resist ink layer 25. The via 23 is equipped with a conductive hole ring 24, and is arranged inside the substrate pad 22. There is no solder resist ink inside the substrate pad 22, and the solder resist ink layer 25 is arranged in a strip shape next to the Micro LED chip 21.

[0058] In one embodiment of the present application, in the micro-LED array 20 , a solder resist ink layer 25 is disposed between each two adjacent columns of the micro-LEDs 21 , and the solder resist ink layer 25 is connected to the circuit substrate 10 .

[0059] For details, see Figure 2 and Figure 3 In the Micro LED circuit substrate 10, each square frame is in the shape of a Micro LED, that is, a micro light-emitting diode 21 (LED). This is a MiP package. Each micro light-emitting diode 21 includes four square electrodes 211 of RGBC and a special-shaped electrode for routing the internal circuit of the package. These five conductive electrodes 211 need to maintain a safe conductive distance. Therefore, there is basically no conductive wiring space on the circuit board at the corresponding position, and it is impossible to set a Via hole next to the chip for connecting the lower circuit. Pulling the via 23 and the hole ring into the four chip pads solves the spatial wiring problem, and the four pads are all provided with vias 23 to ensure that the pad heights at the four positions of the chip are the same. At the same time, no solder mask ink is set between the four pads of the chip to prevent the chip from riding on the ink and causing poor welding. A long strip of ink that runs through the light board is set next to the chip to ensure the ink adhesion strength and to guide the subsequent black glue perfusion.

[0060] In one embodiment of the present application, the cross-section of the solder resist ink layer 25 is arched, and the solder resist ink layer 25 is used for guiding when forming the adhesive layer 30 .

[0061] Specifically, the Micro LED array is arranged behind the circuit substrate 10, the light board is tilted, a multi-head needle is used to inject liquid glue along the position of the strip solder mask ink, the tilted light board is slowly rotated along the plane of the tilted bracket at a uniform speed, and cured to complete the black glue filling. The black glue curing is heating curing or UV curing.

[0062] See also Figure 1 and Figure 4, the via 23, the conductive hole ring 24, the substrate pad 22 and the micro-LED electrode 211 are in a vertical direction. There is space between each substrate pad 22 (i.e., LED pad), and a solder resist ink layer 25 is set next to the micro-LED 21 (i.e., LED). The cross-section of the solder resist ink is mushroom-shaped (i.e., arched) and is set on the circuit substrate 10, which ensures the adhesion of the ink on the circuit substrate 10. The smooth arc surface serves as a guide for the subsequent glue filling process. The LED chip array (i.e., the micro-LED array 20) is set on the circuit substrate 10 through the mass transfer process, and the circuit connection between the LED electrode and the circuit pad circuit of the circuit substrate 10 is completed through the solder 26.

[0063] See also Figure 1 , Figure 5 and Figure 6 , preheat the lamp board to be injected with glue, place the lamp board on the rotating bracket, and make the lamp board present a certain tilt angle. Use a multi-tip needle to inject liquid black glue along the direction of the strip solder mask ink that runs through the lamp board. The high-temperature black glue flows down along the direction of the solder mask ink and is injected along the arc of the solder mask ink along the chip gap on both sides of the slope. The lamp board is rotated at a uniform speed along the plane of the rotating bracket. As the temperature of the black glue and the lamp board gradually decreases, the black glue gradually solidifies to form a glue layer 30, so that the black glue is evenly filled into the gap position between the LEDs.

[0064] This application uses a multi-tip needle to inject liquid black glue along the direction of the strip solder mask ink that runs through the light board. The light board is placed at an angle and rotates slowly and evenly along the plane of the rotating bracket to evenly fill the gaps between the LEDs with black glue. The high-temperature black glue gradually solidifies to achieve high contrast while maintaining brightness.

[0065] In one embodiment of the present application, the semi-permeable membrane structure 40 is a semi-permeable membrane that is bonded at room temperature or cured by ultraviolet light. The semi-permeable membrane is tightly bonded to the adhesive layer 30 , and the semi-permeable membrane is used to protect the micro-LED array 20 .

[0066] Specifically, the semi-permeable film is attached to the surface of the Micro LED array (ie, the micro light emitting diode array 20 ); the semi-permeable film is a room temperature bonding film or a UV curing film.

[0067] See also Figure 1 , when the light board still has a certain residual temperature, roll the semi-permeable film onto the surface of the LED light board, the semi-permeable film and the black glue are tightly fitted, and the surface is flat, so as to protect the light board and cover the blemishes. The semi-permeable film is a room temperature laminating film or a UV curing film.

[0068] In the present application, when the light board still has a certain residual temperature, the semi-permeable film is rolled and bonded to the surface of the LED light board. The semi-permeable film and the black glue are tightly fitted and the surface is smooth, thereby protecting the light board and concealing blemishes.

[0069] In the embodiment of the present application, the via 23 and the hole ring are pulled into the pad of the Micro LED chip, which solves the problem that the high PPI circuit board cannot be routed due to space limitations. At the same time, the solder resist ink is cleared between the pads at the bottom of the Micro LED chip, and a strip of ink is set next to the Micro LED chip to solve the problem of poor welding and ink loss caused by the Micro LED chip riding on the ink. The problem of filling the gap with black glue in small pitches is completed by tilting the light board and rotating it, and combined with the solution of attaching a semi-transparent film at room temperature, the problem of high PPI and high contrast light board sealing yield is solved, thereby improving production efficiency and reducing costs.

[0070] In one embodiment of the present application, the circuit substrate 10 includes a first circuit board and a second circuit board that are stacked, the micro light emitting diode array 20, the plurality of substrate pads 22 and the solder resist ink layer 25 are respectively connected to the second circuit board, and the first circuit board and the second circuit board are each correspondingly provided with a plurality of connecting holes, and the corresponding plurality of connecting holes on the first circuit board and the second circuit board are connected one-to-one with the plurality of vias 23.

[0071] For details, see Figure 1 , Figure 4 and Figure 5 The circuit substrate 10 includes a multi-layer circuit board, specifically three layers, wherein Figure 1 The first two layers from bottom to top are the first circuit board, and the third layer from bottom to top is the second circuit board. Both the first circuit board and the second circuit board are provided with connection holes (in an inverted trapezoidal shape), which are connected to the via holes 23 on the substrate pads 22 in correspondence.

[0072] Based on the above embodiments, the present application further provides a display device, wherein the display device includes a display light board 100 as described in any one of the above schemes. The Micro LED display device of the present application can be any one of an ultra-high-definition TV, an LED display, an AR\VR\MR display, a monitor, a laptop computer, a mobile phone, and a tablet computer.

[0073] The display device provided in the present application has all the above beneficial effects because it is provided with the display light board described in any of the above technical solutions, which will not be repeated here.

[0074] Based on the above embodiments, Figure 7 As shown, the present application also provides a method for preparing a display light board, the preparation method is used to prepare a display light board as described in any one of the above schemes, and the preparation method of the display light board comprises the following steps:

[0075] In step S101, a circuit substrate and a plurality of micro light emitting diodes are prepared, wherein the micro light emitting diodes are provided with a plurality of electrodes, the circuit substrate is provided with a plurality of substrate pads, the plurality of substrate pads are provided with respective corresponding vias and conductive hole rings, and the conductive hole rings are coaxially arranged with the vias.

[0076] Specifically, the circuit substrate includes a multi-layer circuit board, vias, conductive hole rings, substrate pads and a black solder mask ink layer. The vias and conductive hole rings are arranged inside the substrate pads, and there is no solder mask ink inside the pads. The solder mask ink layer is arranged in a strip shape next to the Micro LED chip.

[0077] This step is the basis of the entire preparation process and provides the necessary circuit connection and layout for subsequent steps. The setting of vias and conductive hole rings solves the problem of space limitation of high PPI circuit boards, while the strip setting of the solder mask ink layer facilitates the subsequent liquid glue injection.

[0078] In step S102, a plurality of the micro-LEDs are arranged on the circuit substrate to form a micro-LED array, so that a plurality of the electrodes are connected to a plurality of substrate pads in a one-to-one correspondence, and the conductive hole ring, the via hole and the electrode are arranged coaxially.

[0079] Specifically, the Micro LED chip array (micro light emitting diode array) is accurately placed on the circuit substrate through a mass transfer process, and the circuit connection between the LED electrode and the circuit substrate pad is completed through solder.

[0080] This step is the key to connecting the circuit substrate and the Micro LED chip, ensuring that each LED chip can work correctly and stably.

[0081] In step S103, a filling material is used to fill the space between the micro light emitting diode arrays on the circuit substrate to form a light board with an adhesive layer.

[0082] In one possible implementation, a vertical strip-shaped solder resist ink layer is arranged between every two columns of the micro-LEDs in the micro-LED array to form a lamp board to be injected with glue; a multi-head needle tube is used to inject filling material into the lamp board to be injected with glue along the solder resist ink layer to obtain a lamp board with a glue layer.

[0083] In a possible implementation, the filling material is liquid black glue. The lamp board to be injected with glue is mounted on a rotating bracket so that the lamp board to be injected with glue is tilted; a multi-head needle is used to inject liquid black glue along the direction of the solder resist ink layer that penetrates the lamp board to be injected with glue, so that the black glue flows downward along the direction of the solder resist ink layer to cover the gaps between the plurality of micro-LEDs; the lamp board to be injected with glue is rotated at a uniform speed along the plane where the rotating bracket is located, so that the black glue flows along the arched surface of the black ink to the horizontal gaps between the micro-LEDs, and solidifies to form a glue layer, thereby obtaining a lamp board with a glue layer.

[0084] Specifically, the light board is placed at an angle, and a multi-head needle is used to inject liquid black glue along the position of the strip solder mask ink; then, the inclined light board is slowly and evenly rotated along the plane of the inclined bracket to evenly fill the black glue into the gaps between the LEDs.

[0085] The liquid glue injection step solves the problem of filling the gaps between tiny gaps with black glue; the tilting and rotating method ensures that the black glue can evenly and completely cover the gaps between the LEDs, thereby improving the contrast and brightness of the display panel.

[0086] Curing the black glue by heating or UV curing is a necessary step after liquid glue injection, which ensures that the black glue can be stably fixed between the LEDs and will not fall off due to movement or temperature changes.

[0087] In step S104, a semi-permeable film structure is used to coat the adhesive layer and the micro light emitting diode array of the light board to obtain a display light board.

[0088] In a possible implementation, the semipermeable membrane structure is a semipermeable membrane. At room temperature, the semipermeable membrane is rolled and laminated on the surface of the adhesive layer and the micro-LED array to obtain a display light board; or under ultraviolet irradiation, the semipermeable membrane is rolled and laminated on the surface of the adhesive layer and the micro-LED array to obtain a display light board.

[0089] Specifically, under the condition that the light board still has a certain residual temperature, the semi-permeable film is rolled and bonded to the surface of the LED light board, so that the semi-permeable film and the black glue are closely fitted and the surface is flat.

[0090] This step is the final protection for the light board, ensuring the durability and concealment effect of the display panel. The lamination of the semi-permeable film needs to be carried out after the black glue is cured to ensure a close bond between the two.

[0091] Finally, the prepared Micro LED display light board will be applied to terminal products (display devices) such as ultra-high-definition TVs, LED displays, AR / VR / MR displays, monitors, laptops, mobile phones, and tablets.

[0092] In the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0093] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0095] It should be noted that: in this application, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0096] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A display light board, characterized in that: The display light board comprises a circuit substrate, a micro light emitting diode array, a glue layer and a semi-permeable membrane structure; The micro-LED array and the adhesive layer are arranged on the circuit substrate, and the adhesive layer is filled between the micro-LED arrays, the semi-permeable membrane structure is covered and connected to the micro-LED array and the adhesive layer, and the micro-LED array includes a plurality of micro-LEDs; Each of the micro-light emitting diodes is provided with a plurality of electrodes, and the plurality of electrodes are connected one-to-one with a plurality of substrate pads. The substrate pads are provided on the circuit substrate, and the plurality of substrate pads are provided with corresponding vias and conductive hole rings, respectively, and the conductive hole rings, the vias and the electrodes are coaxially arranged to electrically connect the micro-light emitting diodes with the circuit substrate through wiring.

2. The display light board according to claim 1, characterized in that: In the micro-LED array, a solder resist ink layer is arranged between each two adjacent columns of the micro-LEDs, and the solder resist ink layer is connected to the circuit substrate.

3. The display light board according to claim 2, characterized in that: The cross section of the solder resist ink layer is arched, and the solder resist ink layer is used for conducting flow when forming the adhesive layer.

4. The display light board according to claim 1, characterized in that: The semipermeable membrane structure is a semipermeable membrane that is bonded at room temperature or cured by ultraviolet rays. The semipermeable membrane is tightly bonded to the adhesive layer, and the semipermeable membrane is used to protect the micro light emitting diode array.

5. The display light board according to claim 2, characterized in that: The circuit substrate includes a first circuit board and a second circuit board which are stacked together, the micro light emitting diode array, the plurality of substrate pads and the solder resist ink layer are respectively connected to the second circuit board, the first circuit board and the second circuit board are respectively provided with a plurality of connection holes, and the corresponding plurality of connection holes on the first circuit board and the second circuit board are connected one-to-one with the plurality of vias.

6. A display device, characterized in that: The display device comprises the display light board according to any one of claims 1 to 5.

7. A method for preparing a display light panel, characterized in that: The preparation method is used to prepare the display light board according to any one of claims 1 to 6, and the preparation method of the display light board comprises: Prepare a circuit substrate and a plurality of micro-light emitting diodes, wherein the micro-light emitting diodes are provided with a plurality of electrodes, the circuit substrate is provided with a plurality of substrate pads, the plurality of substrate pads are provided with respective corresponding via holes and conductive hole rings, and the conductive hole rings are coaxially arranged with the via holes; Arranging a plurality of the micro-LEDs on the circuit substrate to form a micro-LED array, so that a plurality of the electrodes are connected to a plurality of substrate pads in a one-to-one correspondence, and the conductive hole ring, the via hole and the electrode are arranged coaxially; Filling the micro-LED arrays with filling material on the circuit substrate to form a light board with a glue layer; A semi-permeable film structure is used to coat the adhesive layer of the light board and the micro light emitting diode array to obtain a display light board.

8. The method for preparing a display light board according to claim 7, characterized in that: The method of using a filling material on the circuit substrate to fill the space between the micro light emitting diode arrays to form a light board with a glue layer specifically includes: A vertical strip-shaped solder resist ink layer is provided between every two columns of the micro-light emitting diodes in the micro-light emitting diode array to form a light board to be injected with glue; A multi-head needle tube is used to inject the filling material into the lamp board to be injected with glue along the solder resist ink layer to obtain a lamp board with a glue layer.

9. The method for preparing a display light board according to claim 8, characterized in that: The filling material is liquid black glue; The method of injecting the filling material into the light board to be injected with glue along the solder resist ink layer using a multi-head needle tube to obtain a light board with a glue layer specifically includes: Mounting the light board to be injected with glue on a rotating bracket so that the light board to be injected with glue is in an inclined state; Using a multi-head needle tube to inject liquid black glue along the direction of the solder resist ink layer that penetrates the light board to be injected, so that the black glue flows downward along the direction of the solder resist ink layer to cover the gaps between the plurality of micro light emitting diodes; The lamp board to be injected with glue is rotated at a uniform speed along the plane where the rotating bracket is located, so that the black glue flows along the arched surface of the black ink into the lateral gap of the micro-light-emitting diode array and solidifies to form a glue layer to obtain a lamp board with a glue layer.

10. The method for preparing a display light board according to claim 7, characterized in that: The semipermeable membrane structure is a semipermeable membrane; The semi-permeable film structure is used to coat the adhesive layer of the light board and the micro-light emitting diode array to obtain a display light board, specifically: At room temperature, rolling and laminating the semipermeable membrane on the surface of the adhesive layer and the micro-LED array to obtain a display light board; or Under ultraviolet irradiation, the semi-permeable membrane is rolled and laminated on the surface of the adhesive layer and the micro-light emitting diode array to obtain a display light board.

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