Display backplane assembly, LED display module and device, and related methods

Abstract

The present application relates to a display backplane assembly, an LED display module and device, and related methods. The display backplane assembly includes a display backplane and a planarization layer. The display backplane has a first surface, and an electrode connecting piece is provided on the first surface. The planarization layer is stacked on the first surface; the planarization layer is provided with a plurality of accommodating holes extending in the thickness direction, and the plurality of accommodating holes correspond to the electrode connecting piece; the plurality of accommodating holes include a first hole and a second hole, the first hole is filled with welding material, and the welding material is in contact with the electrode connecting piece; the second hole is filled with adhesive. The LED chip is pre-fixed with adhesive, and the welding material is only in contact but not fixed. At this time, an electrical connection stability test is performed. Because the welding material is only in contact with the electrode of the LED chip and is not fixed, it can prevent the welding material from being affected by the bad LED chip, and it is easier to repair another LED chip later.

Description

Technical Field

[0001] The present application relates to the field of display, and in particular to a display backplane assembly, an LED display module and device, and related methods. Background Art

[0002] Currently, micro light-emitting diode (micro LED) display panels, as a new generation of display technology, have advantages such as higher brightness, better luminous efficiency and lower power consumption, making micro LEDs widely used.

[0003] A Micro-LED display panel generally includes multiple pixel areas, each of which includes a red LED chip, a blue LED chip, and a green LED chip. During the display panel preparation process, the three chips need to be transferred from their respective growth substrates to the display backplane. The current transfer method is: use a temporary substrate to bond the red LED chip to a temporary substrate; then laser peel the growth substrate of the red LED chip, at which time the red LED chip is transferred to the temporary substrate; then use a transfer substrate to transfer the red LED chip on the temporary substrate to the display backplane. The blue LED chip and the green LED chip are transferred separately in the same way. The process of transferring the LED chip to the display backplane is also the process of mass welding.

[0004] However, current soldering methods require a post-soldering electrical connection stability test, during which the connection strength between the LED chip and the display backplane remains high. If a bad pixel is detected, the LED chip must be removed with considerable force, making the removal difficult and potentially removing the solder. This makes subsequent trimming of another LED chip to the bad pixel location more difficult. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of this application is to provide a display backplane assembly, an LED display module and device, and related methods, aiming to solve the problem that it is difficult to remove bad LED chips and subsequently repair another LED chip.

[0006] In a first aspect, the present application provides a display backplane assembly, comprising: a display backplane, the display backplane having a first surface, an electrode connecting piece being provided on the first surface; a planarization layer, the planarization layer being stacked on the first surface; the planarization layer being provided with a plurality of accommodating holes extending along its thickness direction, the plurality of accommodating holes corresponding to the electrode connecting piece; the plurality of accommodating holes including a first hole and a second hole, the first hole penetrating the planarization layer along the thickness direction so that at least a portion of the electrode connecting piece is exposed relative to the planarization layer; the second hole penetrating at least one side of the planarization layer away from the display backplane; the first hole being filled with welding material so that the welding material is in contact with the electrode connecting piece; the second hole being filled with adhesive glue; the welding material being used to electrically connect the electrode of the LED chip and the electrode connecting piece, and the adhesive glue being used to fix the LED chip on the planarization layer.

[0007] The soldering material contacts the LED chip's electrodes without securing them, while the adhesive bonds the LED chip's electrodes to the planarization layer, pre-fixing the LED chip to the display backplane. At this point, the LED chip is electrically connected to the display backplane, allowing for electrical connection stability testing. If a bad pixel is detected during testing, the chip can be removed simply by applying a slight force, as it is pre-secured with the adhesive. Furthermore, since the soldering material only contacts the LED chip's electrodes and is not secured, it is prevented from being affected by the bad chip, making subsequent repairs to another LED chip much easier.

[0008] Optionally, the first holes and the second holes are alternately spaced in a direction perpendicular to the thickness of the planarization layer. This allows for more uniform contact between the adhesive and the LED chip electrodes, thereby increasing the stability of the LED chip pre-fixing process. It also allows for more uniform contact between the soldering material and the LED chip electrodes, thereby increasing electrical connection stability and connection strength after subsequent soldering.

[0009] Optionally, in a direction perpendicular to the thickness direction of the planarization layer, there is a gap between any two adjacent receiving holes, and the radial dimension of the gap is larger than the aperture of the receiving hole. This can reduce the difficulty of processing the receiving holes and thus reduce costs.

[0010] Optionally, the gap size a and the aperture b of the receiving hole meet the following condition: a is greater than or equal to 2 times b and less than or equal to 2.5 times b. This ensures sufficient contact area between the solder material and the LED chip while reducing costs.

[0011] Optionally, the diameter of the receiving hole on the side close to the display back plate is larger than the diameter of the hole on the side away from the display back plate. The welding material and adhesive can be printed in a good manner using a jet printing method, thereby increasing the convenience of operation.

[0012] Alternatively, the aperture of the receiving hole on the side closest to the display backplane is smaller than the aperture on the side farther from the display backplane. This increases the contact area between the soldering material and the LED chip electrodes, strengthening the electrical connection. The adhesive also increases the contact area between the LED chip electrodes, increasing the stability of the LED chip pre-fixture.

[0013] Optionally, the diameter of the first hole on the side closest to the display backplane is larger than the diameter on the side further away from the display backplane; and the diameter of the second hole on the side closest to the display backplane is smaller than the diameter on the side further away from the display backplane. This increases the contact area between the adhesive and the LED chip electrodes, thereby enhancing the stability of the LED chip pre-fixing and facilitating the printing of solder material in the first hole.

[0014] Alternatively, the diameter of the first hole on the side closest to the display backplane is smaller than the diameter on the side further away from the display backplane; and the diameter of the second hole on the side closest to the display backplane is larger than the diameter on the side further away from the display backplane. This increases the contact area between the solder material and the LED chip's electrode, thereby enhancing the stability of the LED chip's electrical connection and facilitating the preparation of adhesive in the second hole.

[0015] Optionally, the soldering material is flush with the surface of the planarization layer facing away from the display backplane, or the soldering material protrudes relative to the surface of the planarization layer facing away from the display backplane, thereby increasing the reliability of the contact between the soldering material and the electrodes of the LED chip.

[0016] Optionally, the second hole also penetrates the side of the planarization layer facing the display backplane, thereby reducing the processing difficulty and saving costs.

[0017] Optionally, the material of the planarization layer includes at least one of polymethyl methacrylate, polystyrene, polymer derivatives having phenolic groups, acrylic polymers, imide polymers, aromatic ether polymers, amide polymers, fluorine polymers, paraxylene polymers and vinyl alcohol polymers.

[0018] The second aspect of the present application provides an LED display module, comprising an LED chip and a display backplane assembly according to any one of the first aspects of the present application; the LED chip is arranged on a side of the planarization layer facing away from the display backplane; the LED chip has an electrode, the electrode corresponds to at least part of the first hole and at least part of the second hole, the electrode is electrically connected to the electrode connecting sheet through a welding material, and the electrode is connected to the planarization layer through an adhesive.

[0019] A third aspect of the present application provides an LED display device, comprising the display module of any one of the second aspect of the present application.

[0020] The fourth aspect of the present application provides a method for preparing a display backplane assembly, including: preparing a planarization layer on the first surface of the display backplane; providing an electrode connecting piece on the first surface; opening a plurality of accommodating holes along the thickness direction of the planarization layer; the plurality of accommodating holes correspond to the electrode connecting piece, and at least part of the electrode connecting piece is exposed relative to the planarization layer; the plurality of accommodating holes include a first hole and a second hole; the first hole penetrates the planarization layer along the thickness direction so that at least part of the electrode connecting piece is exposed relative to the planarization layer; the second hole penetrates the side of the planarization layer away from the display backplane along the thickness direction; filling the first hole with welding material, and the welding material is in contact with the electrode connecting piece; and filling the second hole with adhesive glue.

[0021] In the LED display backplane prepared using the above method, the first hole is filled with solder material, and the second hole is filled with adhesive. When the LED chip is placed on the LED display backplane, the solder material electrically connects the LED chip to the electrode connector but does not secure it. The adhesive bonds the LED chip's electrodes to the planarization layer, thereby pre-fixing the LED chip to the display backplane. Since the LED chip is already electrically connected to the display backplane during pre-fixing, the LED chip can be tested for electrical connection stability after pre-fixing. If a bad pixel is detected during testing, the bad LED chip can be removed and another LED chip installed. Because the LED chip is pre-fixed with adhesive, removing the bad LED chip with a slight external force is relatively simple. Furthermore, because the solder material only contacts the LED chip's electrodes and is not secured, it is prevented from being affected by the bad LED chip, making subsequent repair of another LED chip easier.

[0022] The fifth aspect of the present application provides a method for preparing an LED display module, including: preparing a planarization layer on the first surface of a display backplane; providing an electrode connecting piece on the first surface; opening a plurality of accommodating holes on the planarization layer along its thickness direction; the plurality of accommodating holes correspond to the electrode connecting piece, and at least part of the electrode connecting piece is exposed relative to the planarization layer; the plurality of accommodating holes include a first hole and a second hole; the first hole penetrates the planarization layer along the thickness direction so that at least part of the electrode connecting piece is exposed relative to the planarization layer; the second hole penetrates at least one side of the planarization layer away from the display backplane; filling the first hole with welding material, the welding material contacts the electrode connecting piece; filling the second hole with adhesive glue; transferring the LED chip to the side of the planarization layer away from the display backplane; the LED chip has an electrode, the electrode corresponds to at least part of the first hole and at least part of the second hole, the electrode is electrically connected to the electrode connecting piece through the welding material, and the electrode is connected to the planarization layer through the adhesive glue.

[0023] In the LED display backplane prepared by the above method, the first hole is filled with soldering material and the second hole is filled with adhesive. The soldering material electrically connects the LED chip to the electrode connecting piece but does not fix it. The adhesive bonds the LED chip's electrodes to the planarization layer, thereby pre-fixing the LED chip to the display backplane. Since the LED chip is already electrically connected to the display backplane during pre-fixation, the LED chip can be tested for electrical connection stability after pre-fixation is completed. If a bad point is detected during the test, the bad LED chip can be removed and another LED chip can be installed. When removing the bad LED chip, since the LED chip is pre-fixed with adhesive, it can be removed with a slight external force, making the operation relatively simple. In addition, since the soldering material only contacts the LED chip's electrodes and is not fixed, it can be prevented from being affected by the bad LED chip, making it easier to subsequently repair another LED chip.

[0024] The sixth aspect of the present application provides a repair method, which is applied to the LED display module of the second aspect of the present application, or to the LED display device of the third aspect of the present application, including: detecting the electrical connection stability of the LED chip; when the electrical connection stability of the LED chip is detected to be abnormal, removing the LED chip from the display backplane assembly; adding another LED chip to the display backplane assembly; the other LED chip has an electrode, the electrode corresponds to at least part of the first hole and at least part of the second hole, the electrode is electrically connected to the electrode connecting piece through a welding material, and the electrode is connected to the planarization layer through an adhesive.

[0025] In this application, when removing a broken LED chip, because the LED chip is pre-fixed with adhesive, a slight external force can be applied to remove the broken LED chip, making the operation relatively simple. Furthermore, because the soldering material only contacts the electrodes of the LED chip and is not fixed, the soldering material is prevented from being affected by the broken LED chip, making it easier to repair another LED chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the growth substrate provided in an embodiment of the present application.

[0027] Figure 2 This is a schematic structural diagram of the growth substrate provided in another direction in an embodiment of the present application.

[0028] Figure 3 This is a schematic structural diagram of a temporary substrate provided in an embodiment of the present application bonded to a growth substrate.

[0029] Figure 4 This is a structural diagram of the process of transferring LED chips from a temporary substrate to a growth substrate provided in an embodiment of the present application.

[0030] Figure 5 This is a structural schematic diagram of a temporary substrate with LED chips transferred provided in an embodiment of the present application.

[0031] Figure 6 This is a structural schematic diagram of the temporary substrate provided in an embodiment of the present application for transferring an LED chip in another direction.

[0032] Figure 7 This is a structural diagram of transferring LED chips to a display backplane on a transfer substrate provided in an embodiment of the present application.

[0033] Figure 8 This is a structural diagram of a display backplane with LED chips transferred provided in an embodiment of the present application.

[0034] Figure 9 It is a structural schematic diagram of one of the display backplane components provided in an embodiment of the present application.

[0035] Figure 10 It is a structural schematic diagram of a display backplane assembly provided in another embodiment of the present application.

[0036] Figure 11 This is a structural diagram of a display backplane assembly provided in yet another embodiment of the present application.

[0037] Figure 12 This is a structural diagram of a display backplane assembly provided in yet another embodiment of the present application.

[0038] Figure 13 This is a structural diagram of a display backplane assembly provided in yet another embodiment of the present application.

[0039] Figure 14 It is a structural diagram of the LED display module provided in an embodiment of the present application.

[0040] Figure 15 This is a flow chart of the preparation process of the display backplane assembly provided in an embodiment of the present application.

[0041] Figure 16 It is a schematic diagram of a method for preparing a display backplane assembly provided in an embodiment of the present application.

[0042] Figure 17 This is a schematic diagram of the preparation process of the LED display module provided in an embodiment of the present application.

[0043] Figure 18 This is a flow chart of a method for preparing an LED display module provided in an embodiment of the present application.

[0044] Figure 19 This is a schematic diagram of the repair process of the LED display module provided in an embodiment of the present application.

[0045] Figure 20 This is a flow chart of a method for repairing an LED display module provided in an embodiment of the present application.

[0046] Explanation of the accompanying drawings: 10 - growth substrate, 20 - LED chip, 30 - temporary substrate, 40 - transfer substrate; 100 - display backplane, 110 - electrode connecting plate 200 - planarization layer, 210 - receiving hole, 211 - first hole, 212 - second hole, 300 - welding material, 400 - adhesive, X - thickness direction, Y - horizontal direction. DETAILED DESCRIPTION

[0047] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0049] For details, please refer to Figures 1 to 6 ,visible, Figure 1 is a schematic structural diagram of a growth substrate provided in an embodiment of the present application; Figure 2 This is a schematic structural diagram of the growth substrate provided in another direction according to an embodiment of the present application;

[0050] Figure 3 Schematic diagram of the structure of a temporary substrate bonded to a growth substrate provided in an embodiment of the present application; Figure 4 This is a structural diagram of the process of transferring an LED chip from a temporary substrate to a growth substrate provided by an embodiment of the present application; Figure 5 This is a structural diagram of a temporary substrate with an LED chip transferred thereto provided in an embodiment of the present application;

[0051] Figure 6 This is a structural schematic diagram of the temporary substrate provided in an embodiment of the present application for transferring an LED chip in another direction.

[0052] Generally, when the LED chip 20 is transferred to the display backplane 100, the red LED chip, blue LED chip and green LED chip are transferred separately. The following is explained using one LED chip 20 as an example. The same principle applies to the other two LED chips and will not be repeated in this application.

[0053] The LED chip 20 is transferred to the display backplane 100. The specific process is as follows:

[0054] Step S10: Provide a growth substrate 10 (wafer) with an LED chip 20 grown thereon. Then, using the adhesive layer on a temporary substrate 30, adhere the LED chip 20 to the temporary substrate 30. Next, peel off the growth substrate 10 from the LED chip 20. This allows the LED chip 20 to be transferred to the temporary substrate 30.

[0055] Step S11: selectively bonding the LED chip 20 to the transfer substrate 40 using the adhesive layer on the transfer substrate 40; Figure 7 , Figure 7 4 shows that the transfer substrate 40 selectively bonds the LED chip 20 to the temporary substrate 30 .

[0056] Step S12: Transfer the LED chip 20 on the transfer substrate 40 to the display backplane 100. Figure 8 , Figure 8 Figure 4 shows a schematic diagram of the successful transfer of LED chips 20 onto the display backplane 100. The process of transferring the LED chips 20 onto the display backplane 100 using the transfer substrate 40 also involves a mass soldering process. Therefore, after the transfer is complete, the LED chips 20 have completed the gold-indium eutectic bonding.

[0057] After the transfer is complete, that is, after the gold-indium eutectic bonding is complete, the electrical connection stability of the LED chip 20 is tested. If a bad pixel is detected, the bad LED chip 20 is removed and another LED chip 20 is added to the bad pixel. However, current soldering methods perform electrical connection stability testing after the gold-indium eutectic bonding is complete, during which the connection strength between the LED chip 20 and the display backplane 100 is relatively high. If a bad pixel is detected, the removal of the LED chip 20 requires a significant external force, which is difficult and can easily remove the solder, making subsequent trimming of another LED chip 20 to the bad pixel location more difficult.

[0058] Based on this, the present application hopes to provide a display backplane assembly, LED display module and device, and related methods that can solve the above-mentioned technical problems, the details of which will be explained in subsequent embodiments.

[0059] refer to Figure 9 , Figure 9 1 is a schematic structural diagram of a display backplane assembly provided in an embodiment of the present application. The display backplane assembly provided in an embodiment of the present application comprises: a display backplane 100 and a planarization layer 200. The planarization layer 200 is made of a non-conductive material.

[0060] The display back panel 100 has a first surface and a second surface that are oppositely disposed. Figure 9 With the center direction as a reference, the upper surface of the display backplane 100 is the first surface, and the lower surface is the second surface. An electrode pad 110 is provided on the first surface. A planarization layer 200 is laminated on the first surface. The planarization layer 200 is provided with a plurality of receiving holes 210 extending along its thickness direction X, corresponding to the electrode pad 110. The plurality of receiving holes 210 include a first hole 211 and a second hole 212. The first hole 211 penetrates the planarization layer 200 along the thickness direction X, exposing at least a portion of the electrode pad 110 relative to the planarization layer 200. The second hole 212 penetrates at least one side of the planarization layer 200 facing away from the display backplane 100 along the thickness direction X. The first hole 211 is filled with welding material 300, which contacts the electrode pad 110. The second hole 212 is filled with adhesive 400.

[0061] The soldering material 300 is used to electrically connect the electrodes of the LED chip 20 to the electrode connecting piece 110, and the adhesive 400 is used to secure the LED chip 20 to the planarization layer 200. Specifically, the LED chip 20 is disposed on a side of the planarization layer 200 facing away from the display backplane 100. The LED chip 20 has electrodes corresponding to at least a portion of the first hole 211 and at least a portion of the second hole 212. The electrodes are electrically connected to the electrode connecting piece 110 via the soldering material 300, and the electrodes are connected to the planarization layer 200 via the adhesive 400.

[0062] The display backplane 100 may be a thin film transistor (TFT) circuit board, and the soldering material 300 may be metallic indium. This soldering material 300 provides high reliability after soldering. The adhesive 400 may be NCF adhesive, which is relatively low-cost and has suitable adhesion. The adhesive 400 is made of a non-conductive material.

[0063] The material of planarization layer 200 includes at least one of organic materials selected from polymethyl methacrylate, polystyrene, polymer derivatives containing phenolic groups, acrylic polymers, imide polymers, aromatic ether polymers, amide polymers, fluorine polymers, paraxylene polymers, and vinyl alcohol polymers. In other words, planarization layer 200 can be made from any one of these materials, or a mixture of two or more. These materials are readily available, cost-effective, and easy to process.

[0064] In this embodiment, a planarization layer 200 is stacked on the display backplane 100. This planarization layer 200 can eliminate the step difference caused by differences in processing precision on the circuit backplane and facilitate the connection between the display backplane 100 and the LED chip 20. Specifically, a receiving hole 210 is provided on the planarization layer 200 at a position corresponding to the electrode connecting piece 110. The first hole 211 of the receiving hole 210 is filled with soldering material 300, and the second hole 212 is filled with adhesive 400. The electrode of the LED chip 20 is then aligned with the receiving hole 210. At this time, the upper and lower sides of the soldering material 300 contact the electrode of the LED chip 20 and the electrode connecting piece 110, respectively, thereby achieving an electrical connection between the LED chip 20 and the electrode connecting piece 110. The adhesive 400 bonds the electrode of the LED chip 20 to the planarization layer 200, thereby pre-fixing the LED chip 20 to the display backplane 100.

[0065] Since the LED chip 20 is already electrically connected to the display backplane 100 during pre-fixing, the LED chip 20 can be tested for electrical connection stability after pre-fixing is complete. If a bad pixel is detected during testing, the bad LED chip 20 can be removed and another LED chip 20 installed. Because the LED chip 20 is pre-fixed with adhesive 400, removing the bad LED chip 20 with a slight external force is relatively simple. Furthermore, because the soldering material 300 only contacts the electrodes of the LED chip 20 and is not fixed, the soldering material 300 is prevented from being affected by the bad LED chip 20, making subsequent repair of another LED chip 20 easier.

[0066] Once the repair is complete, a soft pressure plate can be placed over the LED chip 20, and then heated and pressurized to achieve mass soldering of the LED chip 20, effectively completing the gold-indium eutectic bonding. This secures the connection between the LED chip 20 and the solder material 300, ensuring a stable electrical connection. The soft pressure plate is a hard quartz substrate with a transfer substrate or polyurethane adhesive applied to it. This plate heats and pressurizes the LED chip 20 while also applying soft pressure to prevent damage.

[0067] Those skilled in the art will appreciate that an LED chip 20 generally has two electrodes, a positive electrode and a negative electrode. Therefore, each LED chip 20 requires two corresponding electrode connecting pieces 110: one positive electrode connecting piece 110 and one negative electrode connecting piece 110. As shown in the figure, the two electrodes of the LED chip 20 correspond one-to-one to the two electrode connecting pieces 110.

[0068] In some embodiments, the first holes 211 and the second holes 212 are alternately spaced in a direction perpendicular to the thickness direction X of the planarization layer 200. With reference to the directions in the figure, the X direction is the thickness direction X, and the Y direction is the horizontal direction Y, i.e., a direction perpendicular to the thickness direction X of the planarization layer 200. Because the first holes 211 are filled with solder material 300 and the second holes 212 are filled with adhesive 400, the first holes 211 and the second holes 212 are alternately spaced, i.e., the solder material 300 and the adhesive 400 are alternately spaced. This allows for more uniform contact points between the adhesive 400 and the electrodes of the LED chip 20, thereby increasing the stability of the pre-fixing of the LED chip 20. It also allows for more uniform contact points between the solder material 300 and the electrodes of the LED chip 20, thereby increasing the stability of the electrical connection and the connection strength after subsequent soldering.

[0069] In some embodiments, a gap exists between any two adjacent receiving holes 210 in a direction perpendicular to the thickness direction X of the planarization layer 200, and the size of the gap along the radial direction of the receiving hole 210 is larger than the diameter of the receiving hole 210. This prevents the gap from being too small, which could lead to communication between two adjacent receiving holes 210 due to machining accuracy. Setting the gap size larger than the diameter of the receiving hole 210 can reduce the difficulty of machining the receiving hole 210, thereby reducing costs.

[0070] Exemplarily, the following conditions are satisfied between the size a of the interval and the aperture b of the receiving hole 210: a is greater than or equal to 2 times b, and less than or equal to 2.5 times b. Because the interval is too large, the number of receiving holes 210 that can be set at the positions corresponding to the planarization layer 200 and the electrode connecting piece 110 is relatively small, and the corresponding filling welding material 300 and adhesive 400 are correspondingly less, and the contact area between the welding material 300 and the electrode of the LED chip 20 is correspondingly reduced, which increases the resistance and affects the welding connection strength and adhesion stability. If the interval is too small, the processing accuracy requirements are very high, resulting in increased costs. Setting the size a of the interval between 2 times and 2.5 times the aperture b of the receiving hole 210 can not only ensure that the welding material 300 and the LED chip 20 have sufficient contact area, but also reduce costs.

[0071] In some embodiments, as Figure 9 As shown, the diameter of the receiving hole 210 close to the display back plate 100 is equal to the diameter of the side away from the display back plate 100. That is, the diameter of the receiving hole 210 is consistent from top to bottom, which can facilitate processing.

[0072] refer to Figure 10 , Figure 10It is a structural schematic diagram of a display backplane assembly provided by another embodiment of the present application. In some embodiments, the aperture of the accommodating hole 210 on the side close to the display backplane 100 is larger than the aperture on the side away from the display backplane 100. Taking the direction in the figure as a reference, the aperture of the accommodating hole 210 gradually increases from top to bottom, presenting a shape that is small at the top and large at the bottom. Thus, when the welding material 300 is filled in the first hole 211, nanosilver can be used as the welding material 300, and nanosilver is sprayed on the planarization layer 200 by electrofluidic printing technology. After the sprayed layer of nanosilver is solidified, continue to spray on the solidified nanosilver layer until the nanosilver fills the entire first hole 211. The structure with a small top and a large bottom is more suitable for spraying nanosilver. Printing NCF glue in the second hole 212 and setting the second hole 212 to a structure with a small top and a large bottom is also convenient for printing NCF glue.

[0073] refer to Figure 11 , Figure 11 is a schematic structural diagram of a display backplane assembly provided by another embodiment of the present application. In other embodiments, the aperture of the receiving hole 210 on the side close to the display backplane 100 is smaller than the aperture on the side away from the display backplane 100. That is, the aperture of the receiving hole 210 gradually decreases from top to bottom, presenting a shape that is larger at the top and smaller at the bottom. As a result, the electrode contact area between the welding material 300 and the LED chip 20 is larger, which can increase the strength of the electrical connection. The adhesive 400 also has a larger contact area with the electrode of the LED chip 20, which can increase the stability of the pre-fixation of the LED chip 20.

[0074] refer to Figure 12 , Figure 12 is a schematic structural diagram of a display backplane assembly provided in yet another embodiment of the present application. In other embodiments, the aperture of the first hole 211 on the side close to the display backplane 100 is larger than the aperture on the side away from the display backplane 100; the aperture of the second hole 212 on the side close to the display backplane 100 is smaller than the aperture on the side away from the display backplane 100. In other words, the aperture of the first hole 211 gradually increases from top to bottom, and the aperture of the second hole 212 gradually decreases from top to bottom. This can increase the contact area between the adhesive 400 and the electrode of the LED chip 20, thereby enhancing the stability of the pre-fixation of the LED chip 20; and facilitate the printing of nanosilver in the first hole 211.

[0075] refer to Figure 13 , Figure 13is a schematic structural diagram of a display backplane assembly provided by another embodiment of the present application. In other embodiments, the aperture of the first hole 211 on the side close to the display backplane 100 is smaller than the aperture on the side away from the display backplane 100; the aperture of the second hole 212 on the side close to the display backplane 100 is larger than the aperture on the side away from the display backplane 100. That is, the aperture of the first hole 211 gradually decreases from top to bottom, and the aperture of the second hole 212 gradually increases from top to bottom. In this way, the contact area between the soldering material 300 and the electrode of the LED chip 20 can be increased, thereby increasing the stability of the electrical connection of the LED chip 20; and facilitating the preparation of the adhesive in the second hole 212.

[0076] In order to ensure that the soldering material 300 is in reliable contact with the electrodes of the LED chip 20 , the soldering material 300 is arranged to be flush with the surface of the planarization layer 200 facing away from the display back plate 100 .

[0077] In other embodiments, to increase the reliability of the contact between the soldering material 300 and the electrodes of the LED chip 20, the soldering material 300 protrudes from the surface of the planarization layer 200 away from the display backplane 100. For example, the soldering material 300 may be 1 micron higher than the planarization layer 200, thereby improving the reliability of the electrical connection.

[0078] As mentioned above, the second hole 212 must penetrate the side of the planarization layer 200 facing away from the display backplane 100 to facilitate the filling of the adhesive 400 and facilitate contact between the adhesive 400 and the electrodes of the LED chip 20 to pre-fix the LED chip 20. In some embodiments, the second hole 212 can be configured not to penetrate the side of the planarization layer 200 facing the display backplane 100, that is, the second hole 212 can be a blind hole. In other embodiments, the second hole 212 also penetrates the side of the planarization layer 200 facing the display backplane 100; that is, the first hole 211 and the second hole 212 are configured to be the same, both penetrating the planarization layer 200. This can reduce processing difficulty and save costs.

[0079] refer to Figure 14 , Figure 14 is a schematic diagram of the structure of the LED display module provided in an embodiment of the present application. Based on the display backplane assembly provided in any of the above embodiments, an embodiment of the present application further provides an LED display module, comprising an LED chip 20 and a display backplane assembly in any of the above embodiments. The LED chip 20 is disposed on a side of the planarization layer 200 facing away from the display backplane 100; the LED chip 20 has an electrode, which corresponds to at least a portion of the first hole 211 and at least a portion of the second hole 212. The electrode is electrically connected to the electrode connecting sheet 110 via a welding material 300, and the electrode is connected to the planarization layer 200 via an adhesive 400.

[0080] In this embodiment, a planarization layer 200 is stacked on the display backplane 100. Receiving holes 210 are provided on the planarization layer 200 at positions corresponding to the electrode connection sheets 110. The first holes 211 of the receiving holes 210 are filled with soldering material 300, and the second holes 212 are filled with adhesive 400. The electrodes of the LED chip 20 are then aligned with the receiving holes 210. At this point, the upper and lower sides of the soldering material 300 contact the electrodes of the LED chip 20 and the electrode connection sheet 110, respectively, thereby electrically connecting the LED chip 20 to the electrode connection sheet 110. The adhesive 400 bonds the electrodes of the LED chip 20 to the planarization layer 200, thereby pre-fixing the LED chip 20 to the display backplane 100.

[0081] Since the LED chip 20 is already electrically connected to the display backplane 100 during pre-fixing, the LED chip 20 can be tested for electrical connection stability after pre-fixing is complete. If a bad pixel is detected during testing, the bad LED chip 20 can be removed and another LED chip 20 installed. Because the LED chip 20 is pre-fixed with adhesive 400, removing the bad LED chip 20 with a slight external force is relatively simple. Furthermore, because the soldering material 300 only contacts the electrodes of the LED chip 20 and is not fixed, the soldering material 300 is prevented from being affected by the bad LED chip 20, making subsequent repair of another LED chip 20 easier.

[0082] Once the repair is complete, a soft pressure plate can be placed over the LED chip 20, and then heated and pressurized to achieve mass soldering of the LED chip 20, effectively completing the gold-indium eutectic bonding. This secures the connection between the LED chip 20 and the solder material 300, ensuring a stable electrical connection. The soft pressure plate is a hard quartz substrate with a transfer substrate 40 or polyurethane adhesive applied to it. This plate heats and pressurizes the LED chip 20 while also applying soft pressure to prevent damage.

[0083] The present invention also provides an LED display device including the display back panel assembly of any embodiment of the present invention. The LED display device can be an LED display screen, as well as a TV, computer, industrial computer, or other device using the LED display screen.

[0084] refer to Figure 15 and Figure 16 , Figure 15 is a flow chart of a method for preparing a display backplane assembly provided in an embodiment of the present application; Figure 16 Schematic diagram of the preparation process of the display backplane assembly provided in the embodiment of the present application. The following details the preparation method of the display backplane assembly in the above embodiment, including:

[0085] S20: A planarization layer 200 is formed on the first surface of the display backplane 100; the electrode connection sheet 110 is provided on the first surface. The planarization layer 200 can be formed by spray printing or by pre-forming the planarization layer 200 and then laminating and fixing the planarization layer 200 on the display backplane 100.

[0086] S21: A plurality of receiving holes 210 are formed in the planarization layer 200 along the thickness direction X. The plurality of receiving holes 210 correspond to the electrode connecting sheet 110, with at least a portion of the electrode connecting sheet 110 exposed relative to the planarization layer 200. The plurality of receiving holes 210 include a first hole 211 and a second hole 212. The first hole 211 penetrates the planarization layer 200 along the thickness direction X, so that at least a portion of the electrode connecting sheet 110 is exposed relative to the planarization layer 200. The second hole 212 penetrates the planarization layer 200 along the thickness direction X on a side facing away from the display backplane 100. Specifically, nanoimprint technology can be used to form a microstructure, which is the receiving hole 210.

[0087] S22: Fill the first hole 211 with soldering material 300, so that the soldering material 300 contacts the electrode connection sheet 110. Specifically, a high-precision metal mask can be used to prepare metal indium in the first hole 211. Alternatively, nanosilver can be spray-printed in the first hole 211 as the soldering material 300.

[0088] S23: Filling the second hole 212 with adhesive 400. Specifically, a high-precision metal mask can be used to prepare the adhesive 400 in the second hole 212.

[0089] The LED display backplane 100 prepared by the above method has the first hole 211 filled with solder material 300, and the second hole 212 filled with adhesive 400. When the LED chip 20 is placed on the LED display backplane 100, the solder material 300 electrically connects the LED chip 20 to the electrode connection sheet 110 but does not secure it. The adhesive 400 bonds the electrodes of the LED chip 20 to the planarization layer 200, thereby pre-fixing the LED chip 20 to the display backplane 100. Since the LED chip 20 is already electrically connected to the display backplane 100 during pre-fixing, the LED chip 20 can be tested for electrical connection stability after pre-fixing. If a bad pixel is detected during the test, the bad LED chip 20 can be removed and another LED chip 20 can be installed. When removing the bad LED chip 20, since the LED chip 20 is pre-fixed with adhesive 400, it can be removed with a slight external force, making the operation relatively simple. Furthermore, since the soldering material 300 is only in contact with the electrodes of the LED chip 20 but not fixed, the soldering material 300 can be prevented from being affected by the defective LED chip 20 , making it easier to subsequently repair another LED chip 20 .

[0090] refer to Figure 17 and Figure 18 , Figure 17 This is a schematic diagram of the preparation process of the LED display module provided in an embodiment of the present application; Figure 18 This is a flow chart of a method for preparing an LED display module provided in an embodiment of the present application. The following details the method for preparing the LED display module, including:

[0091] S30: Prepare a planarization layer 200 on the first surface of the display backplane 100; the first surface is provided with an electrode connection sheet 110. The planarization layer 200 can be prepared by inkjet printing or by pre-preparing the planarization layer 200 and then laminating and fixing the planarization layer 200 on the display backplane 100.

[0092] S31: Multiple receiving holes 210 are formed in the planarization layer 200 along the thickness direction X. The multiple receiving holes 210 correspond to the electrode connecting sheet 110, and at least a portion of the electrode connecting sheet 110 is exposed relative to the planarization layer 200. The multiple receiving holes 210 include a first hole 211 and a second hole 212. The first hole 211 penetrates the planarization layer 200 along the thickness direction X, so that at least a portion of the electrode connecting sheet 110 is exposed relative to the planarization layer 200. The second hole 212 penetrates the planarization layer 200 along the thickness direction X on a side facing away from the display backplane 100. Specifically, a microstructure, namely the receiving holes 210, can be formed using nanoimprint technology.

[0093] S32: Fill the first hole 211 with soldering material 300, so that the soldering material 300 contacts the electrode connection sheet 110. Specifically, a high-precision metal mask can be used to prepare metal indium in the first hole 211. Alternatively, nanosilver can be spray-printed in the first hole 211 as the soldering material 300.

[0094] S33: Filling the second hole 212 with adhesive 400. Specifically, a high-precision metal mask can be used to prepare the adhesive 400 in the second hole 212.

[0095] S34: Transfer the LED chip 20 to the side of the planarization layer 200 facing away from the display backplane 100. The LED chip 20 has electrodes corresponding to at least a portion of the first hole 211 and at least a portion of the second hole 212. The electrodes are electrically connected to the electrode connecting sheet 110 via the soldering material 300, and the electrodes are connected to the planarization layer 200 via the adhesive 400.

[0096] The LED display backplane 100 prepared by the above method has a soldering material 300 filled in the first hole 211 and an adhesive 400 filled in the second hole 212. The soldering material 300 electrically connects the LED chip 20 to the electrode connecting sheet 110 but does not secure it. The adhesive 400 bonds the electrodes of the LED chip 20 to the planarization layer 200, thereby pre-fixing the LED chip 20 to the display backplane 100. Since the LED chip 20 is already electrically connected to the display backplane 100 during pre-fixing, the LED chip 20 can be tested for electrical connection stability after pre-fixing. If a bad pixel is detected during the test, the bad LED chip 20 can be removed and another LED chip 20 can be installed. When removing the bad LED chip 20, since the LED chip 20 is pre-fixed with the adhesive 400, it can be removed with a slight external force, making the operation relatively simple. Furthermore, since the soldering material 300 is only in contact with the electrodes of the LED chip 20 but not fixed, the soldering material 300 can be prevented from being affected by the defective LED chip 20 , making it easier to subsequently repair another LED chip 20 .

[0097] refer to Figure 19 and Figure 20 , Figure 19 Schematic diagram of the repair process of the LED display module provided in an embodiment of the present application; Figure 20 This is a flow chart of a repair method for an LED display module provided in an embodiment of the present application. Based on the LED display module in the above embodiment, the present application also provides a repair method, including:

[0098] S40: Detecting the electrical connection stability of the LED chip 20 .

[0099] S41: When it is detected that the electrical connection stability of the LED chip 20 is abnormal, the LED chip 20 is removed from the display back panel assembly.

[0100] S42: Add another LED chip 20 to the display backplane assembly. The other LED chip 20 has electrodes corresponding to at least a portion of the first hole 211 and at least a portion of the second hole 212. The electrodes are electrically connected to the electrode connecting sheet 110 via soldering material 300 and are connected to the planarization layer 200 via adhesive 400.

[0101] When removing a broken LED chip 20, since the LED chip 20 is pre-fixed with adhesive 400, a slight force is sufficient to remove the broken LED chip 20, making the process relatively simple. Furthermore, since the soldering material 300 only contacts the electrodes of the LED chip 20 and is not fixed, the soldering material 300 is prevented from being affected by the broken LED chip 20, making it easier to repair another LED chip 20.

[0102] Once the repair is complete, a soft pressure plate can be placed over the LED chip 20, and then heated and pressurized to achieve mass soldering of the LED chip 20, effectively completing the gold-indium eutectic bonding. This secures the connection between the LED chip 20 and the solder material 300, ensuring a stable electrical connection. The soft pressure plate is a hard quartz substrate with a transfer substrate or polyurethane adhesive applied to it. This plate heats and pressurizes the LED chip 20 while also applying soft pressure to prevent damage.

[0103] It should be understood that the application of this application is not limited to the above examples. For ordinary technicians in this field, they can make improvements or changes based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A display back panel assembly, characterized in that: include: A display backplane, the display backplane having a first surface, an electrode connecting sheet being provided on the first surface; a planarization layer, wherein the display backplane is stacked on the first surface; the planarization layer is provided with a plurality of receiving holes extending in a thickness direction, wherein the plurality of receiving holes correspond to the electrode connecting pieces; the plurality of receiving holes include a first hole and a second hole, wherein the first hole penetrates the planarization layer in a thickness direction so as to expose at least a portion of the electrode connecting piece relative to the planarization layer; and the second hole penetrates the planarization layer in a thickness direction on a side facing away from the display backplane; the first hole is filled with a welding material, wherein the welding material contacts the electrode connecting piece; and the second hole is filled with an adhesive. The welding material is used to electrically connect the electrodes of the LED chip and the electrode connecting piece, and the adhesive is used to pre-fix the LED chip on the planarization layer.

2. The display back panel assembly according to claim 1, wherein: In a direction perpendicular to the thickness direction, the first holes and the second holes are alternately spaced.

3. The display back panel assembly according to claim 1, wherein: In a direction perpendicular to the thickness direction, there is a gap between any two adjacent receiving holes, and the size of the gap is larger than the aperture of the receiving hole.

4. The display back panel assembly according to claim 1, wherein: The aperture of the receiving hole close to the display back plate is larger than the aperture of the receiving hole away from the display back plate; Alternatively, the aperture of the receiving hole on the side close to the display back plate is smaller than the aperture of the side away from the display back plate; Alternatively, the aperture of the first hole close to the display backplane is larger than the aperture of the first hole away from the display backplane; the aperture of the second hole close to the display backplane is smaller than the aperture of the second hole away from the display backplane; Alternatively, the aperture of the first hole close to the display backplane is smaller than the aperture of the first hole away from the display backplane; the aperture of the second hole close to the display backplane is larger than the aperture of the second hole away from the display backplane.

5. The display back panel assembly according to claim 1, wherein: The welding material is flush with the surface of the planarization layer facing away from the display backplane; Alternatively, the welding material protrudes relative to the surface of the planarization layer away from the display backplane.

6. The display back panel assembly according to claim 1, wherein: The second hole also penetrates a side of the planarization layer facing the display backplane.

7. An LED display module, characterized in that: A display back panel assembly comprising an LED chip and any one of claims 1 to 6; The LED chip is arranged on the side of the planarization layer away from the display back panel; the LED chip has an electrode, the electrode corresponds to at least part of the first hole and at least part of the second hole, the electrode is electrically connected to the electrode connecting piece through the welding material, and the electrode is connected to the planarization layer through the adhesive.

8. An LED display device, characterized in that: Including the display module according to claim 7.

9. A method for preparing a display backplane assembly, characterized in that: include: preparing a planarization layer on the first surface of the display backplane; An electrode connecting piece is provided on the first surface; A plurality of receiving holes are formed on the planarization layer along a thickness direction; The plurality of receiving holes correspond to the electrode connecting sheet, and at least a portion of the electrode connecting sheet is exposed relative to the planarization layer; the plurality of receiving holes include a first hole and a second hole; The first hole penetrates the planarization layer along the thickness direction, so that at least a portion of the electrode connection sheet is exposed relative to the planarization layer; the second hole penetrates the planarization layer along the thickness direction on a side away from the display backplane; Filling the first hole with welding material, wherein the welding material is in contact with the electrode connecting piece; The second hole is filled with adhesive.

10. A repair method, applied to the LED display module according to claim 7, or applied to the LED display device according to claim 8, characterized in that: The repair method comprises: Test the electrical connection stability of LED chips; When detecting that the electrical connection stability of the LED chip is abnormal, removing the LED chip from the display back panel assembly; A new LED chip is added to the display back panel assembly; the new LED chip has an electrode, the electrode corresponds to at least part of the first hole and at least part of the second hole, the electrode is electrically connected to the electrode connecting piece through the welding material, and the electrode is connected to the planarization layer through the adhesive.

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