LED display module, manufacturing method and display device

Abstract

This invention discloses an LED display module, its fabrication method, and a display device. By using magnetic adsorption, the two electrodes of the LED light-emitting chip are respectively fixed to two pads within a sub-pixel region, eliminating the need for die bonding via stencil printing. This reduces costs, improves die bonding reliability, and meets the requirements for LED display devices with a pixel pitch of less than P0.5mm. Furthermore, since the magnetic poles of the two magnets within each sub-pixel region are opposite, the orientation of the LED light-emitting chip during die bonding is guaranteed to meet preset requirements, preventing reverse electrode connection during the die bonding process.

Description

Technical Field

[0001] This invention relates to the field of LED display technology, and in particular to an LED display module, a manufacturing method, and a display device. Background Technology

[0002] Currently, as users demand increasingly higher resolutions from display devices, and with the rapid development and maturation of LED packaging technology, the requirements for pixel pitch (the distance between the center points of two adjacent pixels) are becoming smaller, leading to a growing market demand for pixel pitches below 1.0mm. Traditional LED packaging typically employs Chips On Board (COB) packaging, where the LED light-emitting chip is fixed onto a printed circuit board (PCB) (a process known as die bonding) and then encapsulated.

[0003] In the process of fixing LED chips onto a printed circuit board, a die-bonding material (such as solder paste) is usually applied to the printed circuit board using stencil printing. The LED chips are then fixed to the printed circuit board by the die-bonding material.

[0004] However, with further reduction in dot pitch, uneven solder paste application during die bonding leads to unstable die bonding and high failure rates. Furthermore, when the dot pitch is below P0.5mm, stencil soldering becomes impossible, hindering die bonding. Therefore, the existing solder paste application process can no longer meet the process requirements. Summary of the Invention

[0005] This invention provides an LED display module, a manufacturing method, and a display device, which can reduce costs, improve the reliability of die bonding, and avoid reverse electrode connection during the die bonding process.

[0006] In a first aspect, embodiments of the present invention provide an LED display module, comprising: a substrate and a plurality of LED light-emitting chips arranged in an array;

[0007] The substrate includes a pin layer, an adsorption layer, and a pad layer. The pin layer and the pad layer are located on both sides of the adsorption layer. The substrate is divided into multiple sub-pixel regions corresponding to multiple LED light-emitting chips.

[0008] The adsorption layer includes a plurality of magnets and an insulator, wherein the insulator is located between two adjacent magnets and the magnetic pole direction of the magnets is perpendicular to the substrate.

[0009] Each sub-pixel region includes two magnets, the magnetic poles of the two magnets being in opposite directions;

[0010] The pad layer is provided with pads corresponding to the magnet;

[0011] The pin layer and the pad layer are electrically connected through metal vias penetrating the substrate;

[0012] The LED light-emitting chip includes two magnetic electrodes located on the same side of the LED light-emitting chip, with the magnetic poles of the two electrodes in opposite directions.

[0013] The LED light-emitting chip is fixed to the pad layer by the attraction between the electrode and the magnet, and the electrode is connected to the pad.

[0014] Optionally, a first insulating layer is provided between the adsorption layer and the pin layer, and a second insulating layer is provided between the adsorption layer and the pad layer.

[0015] Optionally, multiple sub-pixel regions are arranged in an array along the X and Y directions, with the X direction perpendicular to the Y direction, and at least two magnets are arranged along the X direction within each sub-pixel region;

[0016] The magnetic poles of two adjacent magnets along the Y direction are opposite.

[0017] Optionally, the substrate has a plurality of recessed receiving positions on the side near the LED light-emitting chip, and the electrode has a protrusion that matches the receiving position, the protrusion being located within the receiving position.

[0018] Optionally, the receiving position is a hemispherical recess, and the protrusion is a hemispherical protrusion.

[0019] Optionally, a tin layer is provided between the protrusion and the pad, and the protrusion and the pad are connected through the tin layer.

[0020] Optionally, the adsorption layer further includes a magnetic ring, which is sleeved around the periphery of the magnet, and the magnetic pole direction of the magnetic ring is opposite to that of the magnetic pole direction of the magnet.

[0021] Optionally, the area of ​​the magnetic ring's vertical projection on the substrate is smaller than the area of ​​the magnet's vertical projection on the substrate.

[0022] Secondly, embodiments of the present invention also provide a method for manufacturing an LED display module, comprising:

[0023] An adsorption plate is provided, the adsorption plate including a carrier and a magnet disposed on the carrier, the magnetic pole direction of the magnet being perpendicular to the carrier, and the magnetic pole directions of the magnets on the adsorption plate being the same;

[0024] Two adsorption plates are bonded together, and the sides of the two carriers on which the magnets are disposed are arranged opposite each other. The adsorption plates are divided into multiple sub-pixel regions, and each sub-pixel region includes two magnets with opposite magnetic pole directions.

[0025] Remove one of the carriers;

[0026] An insulator is filled between two adjacent magnets;

[0027] Remove the carrier to obtain the adsorption layer;

[0028] A pin layer, a pad layer, and metal vias for connecting the pin layer and the pad layer are formed on the adsorption layer. The pad layer is provided with pads corresponding to the magnet, and the metal vias penetrate the adsorption layer.

[0029] An LED light-emitting chip is fixed to the sub-pixel area, wherein the LED light-emitting chip includes two magnetic electrodes located on the same side of the LED light-emitting chip and having opposite magnetic pole directions. The LED light-emitting chip is fixed to the pad layer by the attraction between the electrodes and the magnet, and the electrodes are connected to the pad.

[0030] Optionally, a first insulating layer and a second insulating layer are also formed on opposite sides of the adsorption layer.

[0031] Optionally, the adsorption plate further includes magnetic rings spaced apart from the magnet, providing the adsorption plate comprising:

[0032] Provide a carrier;

[0033] A magnetic layer is formed on the carrier;

[0034] A portion of the magnetic layer is removed, and a plurality of magnets and magnetic rings are formed on the carrier, with the magnets and magnetic rings arranged at intervals.

[0035] Optionally, the adsorption plate further includes a magnetic ring sleeved around the periphery of the magnet, the magnetic pole direction of the magnetic ring being opposite to the magnetic pole direction of the magnet, providing an adsorption plate comprising:

[0036] Provide the primary carrier;

[0037] A magnetic layer is formed on the first carrier;

[0038] A portion of the magnetic layer is removed to form a plurality of magnets on the first carrier;

[0039] Provide a second carrier;

[0040] A magnetic layer is formed on the second carrier;

[0041] A portion of the magnetic layer is removed, and several magnetic rings are formed on the second carrier;

[0042] A first carrier with a magnet formed thereon and a second carrier with a magnetic ring formed thereon are attached together so that the magnet is nested inside the magnetic ring;

[0043] The second carrier is removed to obtain the adsorption plate.

[0044] Optionally, the electrodes of the LED light-emitting chip are provided with protrusions that match the receiving positions, and after removing one of the carriers, it further includes:

[0045] A portion of the magnet is removed, and a receiving position is formed at the end of the magnet that is away from the carrier.

[0046] Optionally, fixing the LED light-emitting chip to the sub-pixel area includes:

[0047] A layer of solder paste is applied to the surface of the protrusion;

[0048] Fix the LED light-emitting chip to the sub-pixel area;

[0049] The solder paste is heated to melt it, forming a tin layer between the bump and the pad, and the bump and the pad are connected by the tin layer.

[0050] Thirdly, embodiments of the present invention also provide a display device, including an LED display module as provided in the first aspect of the present invention.

[0051] The LED display module provided in this invention includes a substrate and a plurality of LED light-emitting chips arranged in an array. The substrate includes a lead layer, an adsorption layer, and a pad layer, with the lead layer and pad layer located on opposite sides of the adsorption layer. The substrate is divided into multiple sub-pixel regions corresponding to the multiple LED light-emitting chips. The adsorption layer includes multiple magnets and insulators, with the insulators located between two adjacent magnets, and the magnetic poles of the magnets perpendicular to the substrate. Each sub-pixel region includes two magnets with opposite magnetic pole directions. The pad layer has pads corresponding to the magnets. The lead layer and the pad layer are connected by metal vias penetrating the substrate. Each LED light-emitting chip includes two magnetic electrodes located on the same side of the LED light-emitting chip, with opposite magnetic pole directions. By magnetic adsorption, the two electrodes of the LED light-emitting chip are respectively fixed to two pads within the sub-pixel region, eliminating the need for die bonding via stencil printing, reducing costs, improving die bonding reliability, and meeting the requirements of LED display devices with a pixel pitch of less than P0.5mm. In addition, since the magnetic poles of the two magnets in each sub-pixel region are opposite, it can be ensured that the orientation of the LED chip meets the preset requirements during die bonding, thus avoiding the situation of reversed electrode connection during die bonding. Attached Figure Description

[0052] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0053] Figure 1 This is a top view of an LED display module provided in Embodiment 1 of the present invention;

[0054] Figure 2 for Figure 1 A cross-sectional view of the LED display module in the image;

[0055] Figure 3 A cross-sectional view of another LED display module provided in an embodiment of the present invention;

[0056] Figure 4 for Figure 1 Schematic diagram of the middle pad layer;

[0057] Figure 5 for Figure 1 A schematic diagram of the middle pin layer;

[0058] Figure 6 A cross-sectional view of another LED display module provided by the present invention;

[0059] Figure 7 A cross-sectional view of another LED display module provided in an embodiment of the present invention;

[0060] Figure 8 for Figure 7 A schematic diagram showing the distribution of the central magnet and magnetic ring;

[0061] Figure 9 for Figure 8 Schematic diagram of the magnet area;

[0062] Figure 10 A cross-sectional view of another LED display module provided in an embodiment of the present invention;

[0063] Figure 11 for Figure 10 Schematic diagram of the middle pad layer;

[0064] Figure 12 This is a flowchart illustrating a method for manufacturing an LED display module according to Embodiment 2 of the present invention;

[0065] Figure 13 This is a schematic diagram of a process for forming an adsorption plate;

[0066] Figure 14 This is a top view of an adsorption plate;

[0067] Figure 15 This is a schematic diagram of the two adsorption plates after they have been glued together.

[0068] Figure 16 for Figure 15 Schematic diagram of the distribution of the central magnet;

[0069] Figure 17 This is a schematic diagram after removing one carrier.

[0070] Figure 18 A schematic diagram showing the filling of an insulator between two adjacent magnets;

[0071] Figure 19 This is a schematic diagram of the adsorption layer formed after the carrier is removed;

[0072] Figure 20 This is a schematic diagram showing the formation of a lead layer and a pad layer on the adsorption layer, respectively.

[0073] Figure 21 This is a top view of another type of adsorption plate;

[0074] Figure 22 This is a top view of another type of adsorption plate;

[0075] Figure 23 This is a schematic diagram of forming a receiving position on a magnet. Detailed Implementation

[0076] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0077] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0078] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. Moreover, the terms "first" and "second" are used merely for descriptive distinction and have no specific meaning.

[0079] Example 1

[0080] Embodiment 1 of the present invention provides an LED display module, Figure 1 This is a top view of an LED display module provided in Embodiment 1 of the present invention. Figure 2 for Figure 1 A cross-sectional view of the LED display module, with the section lines shown as AA, as follows. Figure 1 and Figure 2 As shown, the LED display module includes a substrate 110 and multiple LED light-emitting chips 120 arranged in an array.

[0081] The substrate 110 includes a pin layer 111, an adsorption layer 113 and a pad layer 115. The substrate 110 is divided into multiple sub-pixel regions corresponding to multiple LED light-emitting chips 120, and each sub-pixel region contains one LED light-emitting chip 120.

[0082] Specifically, the adsorption layer 113 includes multiple magnets 1131 and insulators 1132, with the insulators 1132 located between two adjacent magnets 1131. Exemplarily, the magnets 1131 are columnar, and their magnetic poles are perpendicular to the substrate 110. Each sub-pixel region includes two magnets 1131 with opposite magnetic pole directions. Here, S represents the south pole of magnet 1131, and N represents the north pole of magnet 1131. In this embodiment of the invention, the magnetic pole direction refers to the direction from the north pole to the south pole.

[0083] The pad layer 115 includes multiple pads 1151, which are correspondingly arranged with magnets 1131. The LED light-emitting chip 120 includes two magnetic electrodes, namely electrode 121 and electrode 122, which are located on the same side of the LED light-emitting chip 120 and have opposite magnetic pole directions.

[0084] In the above embodiments, the magnet 1131 is made of an insulating magnetic material, so the pad layer 115 and the lead layer 111 can directly contact the magnet 1131. In another embodiment of the present invention, the magnet can be made of a conductive magnetic material. Therefore, an insulating layer needs to be provided between the adsorption layer and the pad layer, and between the adsorption layer and the lead layer, to prevent the pad layer and the lead layer from being electrically connected through the magnet.

[0085] Figure 3 A cross-sectional view of another LED display module provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the difference between this embodiment and the previous embodiment is that the magnet 1131 is made of an insulating magnetic material, a first insulating layer 112 is provided between the adsorption layer 113 and the lead layer 111, and a second insulating layer 114 is provided between the adsorption layer 113 and the pad layer 115, so as to prevent the pad layer 115 and the lead layer 111 from being electrically connected through the magnet 1131. The parts that are the same as those in the previous embodiment will not be described again here.

[0086] The LED chip 120 is fixed to the pad layer 115 by the attraction between its electrodes and the magnet 1131, and the electrodes are connected to the pads 1151. Specifically, the electrode 121 of the LED chip 120 is fixed to a pad 1151 in a sub-pixel area by magnetic attraction, and the electrode 121 is electrically connected to the pad 1151; the other electrode 122 of the LED chip 120 is fixed to another pad 1151 in the same sub-pixel area by magnetic attraction, and the electrode 122 is electrically connected to the pad 1151. By fixing the two electrodes of the LED chip 120 to the two pads 1151 in the sub-pixel area by magnetic attraction, die bonding is not required by stencil printing, which reduces costs, improves die bonding reliability, and can meet the requirements of LED display devices with a pixel pitch of less than P0.5mm. In addition, since the magnetic poles of the two magnets 1131 in each sub-pixel region are opposite, it can be ensured that the orientation of the LED light-emitting chip 120 (the direction of the line connecting electrode 121 to electrode 122) meets the preset requirements during die bonding, thus avoiding the situation where the electrodes are reversed during the die bonding process.

[0087] The pin layer 111 and the pad layer 115 are electrically connected through a metal via 116 penetrating the substrate 110. Specifically, the pin layer 111 may include a plurality of pins 1111 for connecting to external circuits, receiving drive signals sent from external circuits through the pins 1111, thereby driving the LED chip 120 to emit light. It should be noted that, in this embodiment of the invention, the pin layer 111 may also include lines for connecting the pins 1111, and the pad layer 115 may also include lines for connecting the pads 1151; these will not be elaborated further here.

[0088] The LED display module provided in this invention includes a substrate and a plurality of LED light-emitting chips arranged in an array. The substrate includes a lead layer, an adsorption layer, and a pad layer, with the lead layer and pad layer located on opposite sides of the adsorption layer. The substrate is divided into multiple sub-pixel regions corresponding to the multiple LED light-emitting chips. The adsorption layer includes multiple magnets and insulators, with the insulators located between two adjacent magnets, and the magnetic poles of the magnets perpendicular to the substrate. Each sub-pixel region includes two magnets with opposite magnetic pole directions. The pad layer has pads corresponding to the magnets. The lead layer and the pad layer are electrically connected through metal vias penetrating the substrate. Each LED light-emitting chip includes two magnetic electrodes located on the same side of the LED light-emitting chip, with opposite magnetic pole directions. By magnetic adsorption, the two electrodes of the LED light-emitting chip are respectively fixed to two pads within the sub-pixel region, eliminating the need for die bonding via stencil printing, reducing costs, improving die bonding reliability, and meeting the requirements of LED display devices with a pixel pitch of less than P0.5mm. In addition, since the magnetic poles of the two magnets in each sub-pixel region are opposite, it can be ensured that the orientation of the LED chip meets the preset requirements during die bonding, thus avoiding the situation of reversed electrode connection during die bonding.

[0089] In some embodiments of the present invention, multiple sub-pixel regions are arranged in an array along the X and Y directions, with the X direction perpendicular to the Y direction. Within each sub-pixel region, at least two magnets are arranged along the X direction, and the magnetic poles of two adjacent magnets along the Y direction are opposite.

[0090] Figure 4 for Figure 1 Schematic diagram of the middle pad layer, Figure 5 for Figure 1 A schematic diagram of the middle pin layer, as shown below. Figure 4 As shown, multiple sub-pixel regions P are arranged in an array along the X and Y directions, where the X direction is perpendicular to the Y direction. Within sub-pixel region P, two magnets 1131 are arranged along the X direction, with their magnetic poles facing opposite directions. Adjacent magnets 1131 along the Y direction also have opposite magnetic pole directions. Here, S represents the south pole of magnet 1131, and N represents the north pole of magnet 1131. By setting the magnetic pole directions of adjacent magnets 1131 in the Y direction to be opposite, the magnetic pole directions of the corresponding electrodes of magnets 1131 and adjacent LED light-emitting chips 120 in the Y direction are opposite. Their identical magnetic poles repel each other, preventing misalignment of the LED light-emitting chips 120 in the Y direction.

[0091] like Figure 4 , Figure 5As shown, three adjacent sub-pixel regions P form a pixel unit. Each pixel unit includes three LED chips of different emitting colors: a first-color LED chip, a second-color LED chip, and a third-color LED chip. In the same row of pixel units, the anode or cathode pads corresponding to all LED chips are connected together and connected to a corresponding pin 1111 on the pin layer. In the same column of pixel units, the cathode or anode pads corresponding to LED chips of the same color are connected together and connected to a corresponding pin 1111 of that color LED chip. It should be noted that this embodiment of the invention does not limit the arrangement of pins and traces on the pin layer, or pads and traces on the pad layer, as long as the above connection method can be achieved.

[0092] In some embodiments of the present invention, a plurality of receiving positions are recessed on the side of the substrate near the LED light-emitting chip, and the electrode is provided with a protrusion that matches the receiving position, the protrusion being located within the receiving position. By providing the receiving positions, during die bonding, the protrusion of the LED light-emitting chip electrode falls into the receiving position under the action of gravity and magnetic attraction, thereby improving the positional accuracy of the LED light-emitting chip.

[0093] Figure 6 A cross-sectional view of another LED display module provided by the present invention, as shown below. Figure 6 As shown, this embodiment is an improvement on the foregoing embodiment. The same parts as the foregoing embodiment will not be repeated here. The difference is:

[0094] The substrate 110 has multiple recessed receiving positions on the side near the LED chip 120, each receiving position being a hemispherical recess. Electrodes are provided with protrusions 123 that match the receiving positions; these protrusions 123 are hemispherical protrusions located within the receiving positions. By setting the receiving positions as hemispherical recesses and the protrusions 123 as hemispherical protrusions matching the receiving positions, the electrodes will slide along the surface of the hemispherical recesses of the substrate to the center of the receiving positions, further improving the positional accuracy of the LED chip, thanks to the triple guarantee of gravity, magnetic attraction, and the hemispherical design.

[0095] In some embodiments of the present invention, such as Figure 6As shown, a tin layer 130 is provided between the protrusion 123 and the pad 1151, and the protrusion 123 and the pad 1151 are connected through the tin layer 130. Specifically, during the die bonding process, a layer of low-temperature solder paste can be pre-coated on the surface of the protrusion 123. Under the action of magnetic adsorption and gravity, the protrusion 123 will automatically fall into the receiving position. Then, the low-temperature solder paste on the protrusion 123 is melted by low-temperature heating, which completely fills the gap between the hemispherical protrusion 123 and the hemispherical recessed receiving position. After cooling, the electrode and the pad 1151 can be firmly bonded together, ensuring the stability of the connection.

[0096] In some embodiments of the present invention, the adsorption layer further includes a magnetic ring, which is sleeved around the periphery of the magnet, and the magnetic pole direction of the magnetic ring is opposite to that of the magnet. Because the magnetic pole direction of the magnetic ring is opposite to that of the magnet, i.e., the magnetic ring is opposite to the same magnetic pole as the corresponding electrode, a repulsive force is generated around the electrode and points towards the center of the electrode. Under the adsorption effect of the magnet, the electrode can be more accurately fixed on the pad.

[0097] Figure 7 This is a cross-sectional view of another LED display module provided in an embodiment of the present invention. Figure 8 for Figure 7 A schematic diagram showing the distribution of the central magnet and magnetic ring. Figure 9 for Figure 8 A schematic diagram of the magnet region, as shown below. Figures 7-9 As shown, this embodiment is an improvement on the foregoing embodiment. The same parts as the foregoing embodiment will not be repeated here. The difference is:

[0098] The adsorption layer 113 also includes a magnetic ring 1133, which is sleeved around the periphery of the magnet 1131, and the magnetic pole direction of the magnetic ring 1133 is opposite to the magnetic pole direction of the sleeved magnet 1131.

[0099] In embodiments of the present invention, such as Figure 7As shown, since the magnitude of the magnetic force is related to the area of ​​the vertical projection, the area of ​​the vertical projection of the magnetic ring 1133 on the substrate 110 is set to be smaller than the area of ​​the vertical projection of the magnet 1131 on the substrate 110. This ensures that the repulsive force of the magnetic ring 1133 on the electrode is less than the attractive force of the magnet 1131 on the electrode, allowing the electrodes of the LED light-emitting chip to be more accurately fixed on the pads. For example, in a specific embodiment of the present invention, the ratio of the area of ​​the vertical projection of the magnetic ring 1133 on the substrate 110 to the area of ​​the vertical projection of the magnet 1131 on the substrate 110 is between 7:3 and 8:2 (inclusive). It should be noted that in the above embodiment, the LED display module includes 4 pixel units, each pixel unit including 3 LED light-emitting chips, and the 4 pixel units are arranged in a 2×2 matrix. In other embodiments of the present invention, the LED display module may also include other numbers of pixel units, such as 1×1 or 4×4. This embodiment of the present invention does not limit the number of pixel units.

[0100] In the above embodiments, such as Figure 4 As shown, the arrangement of pads 1151 on the substrate 110 can be symmetrical about a centerline parallel to the Y direction, such that the electrodes of two adjacent LED light-emitting chips 120 in the X direction are symmetrical about a centerline parallel to the Y direction. In other embodiments of the present invention, the arrangement of pads on the substrate can be a repeating arrangement along the X direction.

[0101] Figure 10 This is a cross-sectional view of another LED display module provided in an embodiment of the present invention. Figure 11 for Figure 10 A schematic diagram of the middle pad layer, as shown below. Figure 10 and Figure 11 As shown, the parts that are the same as those in the previous embodiments will not be repeated here. The difference is that the pads 1151 on the substrate 110 are arranged in a repeating pattern along the X direction. Therefore, the orientation of each LED chip is consistent, which is beneficial to improving die bonding efficiency.

[0102] It should be noted that in the above embodiments, the magnet 1131 can be a conductive magnetic material. When designing the metal via 116, it is necessary to avoid the magnet 1131 to prevent short circuits. In other embodiments of the present invention, the magnet 1131 can be a non-conductive magnetic material, in which case it is not necessary to avoid the magnet 1131 when designing the metal via 116.

[0103] Example 2

[0104] Figure 12 This is a flowchart of a method for manufacturing an LED display module according to Embodiment 2 of the present invention, as shown below. Figure 12 As shown, the method may specifically include the following steps:

[0105] S11. Provide an adsorption plate, which includes a carrier and a magnet disposed on the carrier. The magnetic pole direction of the magnet is perpendicular to the carrier, and the magnetic pole directions of the magnets on the adsorption plate are the same.

[0106] For example, the adsorption plate can be formed by etching. Figure 13 This is a schematic diagram of a process for forming an adsorption plate. Figure 14 This is a top view of an adsorption plate, such as... Figure 13 , Figure 14 As shown, a magnetic layer 1131a is first formed on the carrier, and then the magnetic layer 1131a is etched to remove part of the magnetic layer 1131a, resulting in the following: Figure 14 The multiple magnets 1131 shown are arranged in a preset manner.

[0107] S12. Two adsorption plates are bonded together, and the sides of the two carriers with magnets are arranged opposite each other. The adsorption plates are divided into multiple sub-pixel regions, and each sub-pixel region includes two magnets with opposite magnetic pole directions.

[0108] Specifically, adhesive can be applied to the surfaces of two adsorption plates, and then the sides of the two carriers with magnets can be placed together and bonded. Figure 15 This is a schematic diagram of the two adsorption plates after they have been glued together. Figure 16 for Figure 15 The diagram shows the distribution of the magnets. After the two adsorption plates are glued together, the magnets 1131 on the two adsorption plates are arranged alternately. Specifically, S represents the south pole of magnet 1131 and N represents the north pole of magnet 1131. Figure 16 In the diagram, the magnet marked S belongs to one adsorption plate, and the magnet marked N belongs to another adsorption plate.

[0109] The adsorption plate is divided into multiple sub-pixel regions P, and each sub-pixel region P includes two magnets 1131 with opposite magnetic pole directions. In this embodiment of the invention, the magnetic pole direction refers to the direction from the North Pole to the South Pole.

[0110] S13, Remove one of the carriers.

[0111] Specifically, one of the carriers can be removed by mechanical grinding. Figure 17 This is a schematic diagram after removing a carrier, such as... Figure 17 As shown, after removing one carrier 112, one end of the magnet 1131 and the gap between two adjacent magnets 1131 are exposed.

[0112] S14. Fill the space between two adjacent magnets with an insulator.

[0113] Figure 18 A schematic diagram showing the filling of an insulator between two adjacent magnets, as shown below. Figure 18 As shown, an insulator 1132 is filled between two adjacent magnets 1131. The insulator 1132 may be resin or other inorganic insulating materials.

[0114] S15. Remove the carrier to obtain the adsorption layer.

[0115] Figure 19 This is a schematic diagram of the adsorption layer formed after the carrier is removed, as shown below. Figure 19 As shown, the adsorption layer 113 after removing the carrier includes a plurality of magnets 1131 arranged at intervals and an insulator 1132 located between two adjacent magnets 1131.

[0116] S16. A pin layer, a pad layer, and metal vias for connecting the pin layer and the pad layer are formed on the adsorption layer. The pad layer is provided with pads corresponding to the magnet, and the metal vias penetrate the adsorption layer.

[0117] Specifically, a metal layer can be electroplated onto the surface of the adsorption layer using chemical or electroplating methods. Subsequently, drilling, chemical plating, or electroplating processes are performed to create metal vias, connecting the upper and lower metal layers. Then, circuit design is carried out through etching and development, forming a pin layer on the surface of the first insulating layer and a pad layer on the surface of the second insulating layer. The pad layer has pads corresponding to the magnet. Figure 20 This diagram illustrates the formation of the pin layer and pad layer on the adsorption layer. A top view of the pad layer can be found in the diagram. Figure 11 ,like Figure 20 As shown, the pad layer 115 and the pin layer 111 are respectively formed on two opposite surfaces of the adsorption layer 113. The pad layer 115 includes a plurality of pads 1151, which are correspondingly disposed with the magnet 1131. The pin layer 111 may include a plurality of pins 1111 for connection with external circuits.

[0118] S17. Fix the LED light-emitting chip to the sub-pixel area, wherein the LED light-emitting chip includes two magnetic electrodes located on the same side of the LED light-emitting chip and with opposite magnetic pole directions. The LED light-emitting chip is fixed to the pad layer by the attraction between the electrodes and the magnet, and the electrodes are connected to the pad.

[0119] Specifically, the LED display module obtained after die bonding can be found in [reference needed]. Figure 10The LED chip 120 includes two magnetic electrodes, electrode 121 and electrode 122, located on the same side of the LED chip 120 with opposite magnetic pole directions. The LED chip 120 is fixed to the pad layer 115 by the attraction between the electrodes and the magnet 1131, and the electrodes are connected to the pad 1151. Specifically, electrode 121 of the LED chip 120 is fixed to a pad 1151 in a sub-pixel area by magnetic attraction, and electrode 121 is electrically connected to the pad 1151; the other electrode 122 of the LED chip 120 is fixed to another pad 1151 in the same sub-pixel area by magnetic attraction, and electrode 122 is electrically connected to the pad 1151.

[0120] The LED display module fabrication method provided in this invention simplifies the fabrication process by bonding two adsorption plates together to form an adsorption layer. Furthermore, the fabricated LED display module uses magnetic adsorption to fix the two electrodes of the LED light-emitting chip onto two pads within the sub-pixel region, eliminating the need for die bonding via stencil printing, thus reducing costs, improving die bonding reliability, and meeting the requirements for LED display devices with a pixel pitch of less than 0.5mm. Additionally, since the magnetic poles of the two magnets within each sub-pixel region are opposite, the orientation of the LED light-emitting chip during die bonding meets preset requirements, preventing reverse electrode connection during the die bonding process.

[0121] In some embodiments of the present invention, the magnet 1131 is made of an insulating magnetic material, so the pad layer 115 and the lead layer 111 can directly contact the magnet 1131. In another embodiment of the present invention, the magnet can be made of a conductive magnetic material. Therefore, after forming the adsorption layer, a first insulating layer and a second insulating layer need to be formed on opposite sides of the adsorption layer before forming the lead layer, the pad layer, and the metal via, to prevent the pad layer and the lead layer from being electrically connected through the magnet.

[0122] In another embodiment of the invention, the adsorption plate further includes magnetic rings arranged at intervals from the magnet. Figure 21 A top view of another type of adsorption plate, wherein the adsorption plate includes:

[0123] A carrier is provided, and a magnetic layer 1131a is pre-formed on the carrier. Then, a portion of the magnetic layer 1131a is removed, and several magnets 1131 and magnetic rings 1133 are formed on the carrier. For example... Figure 21 As shown, magnets 1131 and magnetic rings 1133 are arranged at intervals.

[0124] When the two adsorption plates are bonded together, the magnet 1131 on the adsorption plate and the magnetic ring 1133 on the other adsorption plate are nested together to form an adsorption layer.

[0125] Other steps are similar to those in the aforementioned embodiments, and will not be repeated here.

[0126] In another embodiment of the invention, the adsorption plate further includes a magnetic ring sleeved around the periphery of the magnet, the magnetic pole direction of the magnetic ring being opposite to the magnetic pole direction of the magnet. Figure 22 A top view of another type of adsorption plate, wherein the adsorption plate includes:

[0127] A first carrier is provided, and a magnetic layer 1131a is formed on the first carrier. Then, a portion of the magnetic layer 1131a is removed, and a plurality of magnets 1131 are formed on the first carrier.

[0128] A second carrier is provided, and a magnetic layer 1131a is formed on the second carrier. Then, part of the magnetic layer 1131a is removed, and a plurality of magnetic rings 1133 are formed on the second carrier.

[0129] Then, the first carrier with the magnet 1131 and the second carrier with the magnetic ring 1133 are attached together so that the magnet 1131 is nested inside the magnetic ring 1133.

[0130] Finally, the second carrier is removed, resulting in the following: Figure 22 The adsorption plate shown has multiple magnets 1131 arranged in a preset manner, and each magnet 1131 is fitted with a magnetic ring 1133 around its periphery. The magnetic pole direction of the magnetic ring 1133 is opposite to the magnetic pole direction of the fitted magnet 1131.

[0131] By bonding the two adsorption plates together, an adsorption layer is obtained.

[0132] Other steps are similar to those in the aforementioned embodiments, and will not be repeated here.

[0133] In another embodiment of the invention, after removing one of the carriers, the method further includes: removing a portion of the magnet and forming a receiving position at the end of the magnet away from the carrier.

[0134] Figure 23 A schematic diagram of forming a receiving position on a magnet, such as Figure 23 As shown, after removing one of the carriers, a portion of the magnet 1131 is removed, forming a receiving position at the end of the magnet 1131 away from the carrier. Exemplarily, in this embodiment of the invention, the receiving position is a hemispherical recess. Correspondingly, the electrodes of the LED light-emitting chip are provided with protrusions that match the receiving position, and these protrusions are hemispherical protrusions.

[0135] Other steps are similar to those in the aforementioned embodiments, and will not be repeated here.

[0136] Based on the above embodiments, fixing the LED light-emitting chip to the sub-pixel area includes:

[0137] A layer of low-temperature solder paste is applied to the surface of the protrusion. Next, the LED chip is fixed to the sub-pixel area, and the solder paste is heated to melt it, filling the gap between the hemispherical protrusion and the hemispherical recess. After cooling, a solder layer is formed between the protrusion and the pad, allowing the electrode and the pad to adhere firmly together, ensuring the stability of the connection.

[0138] Other steps are similar to those in the aforementioned embodiments, and will not be repeated here.

[0139] This invention also provides a display device, including the LED display module provided in the foregoing embodiments. The display device has the corresponding functions and effects of the LED display module provided in the foregoing embodiments of this invention. The display device can be a portable smart device such as a smartphone or tablet computer, or a fixed vertical display device such as a computer monitor or a conference room monitor. This invention does not limit the scope of the invention.

[0140] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," etc., are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0141] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0142] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0143] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. An LED display module, characterized by The application relates to a substrate and a plurality of array-arranged LED light-emitting chips. The substrate comprises a pin layer, an adsorption layer and a pad layer, the pin layer and the pad layer are respectively located on two sides of the adsorption layer, and the substrate is divided into a plurality of sub-pixel regions corresponding to the plurality of LED light-emitting chips. The adsorption layer comprises a plurality of magnets and insulators, the insulators are located between two adjacent magnets, and the magnet pole directions of the magnets are perpendicular to the substrate. Each sub-pixel region comprises two magnets, and the magnet pole directions of the two magnets are opposite. The pad layer is provided with a pad corresponding to the magnet. The pin layer and the pad layer are electrically connected through a metal via hole penetrating through the substrate. The LED light-emitting chip comprises two electrodes with magnetism, the two electrodes are located on the same side of the LED light-emitting chip, and the magnet pole directions of the two electrodes are opposite. The LED light-emitting chip is fixed on the pad layer through the adsorption of the electrodes and the magnets, and the electrodes are connected with the pads. The plurality of sub-pixel regions are array-arranged along X and Y directions, the X direction is perpendicular to the Y direction, at least two magnets in the sub-pixel region are arranged along the X direction. The magnet pole directions of two adjacent magnets along the Y direction are opposite. The adsorption layer further comprises a magnetic ring, the magnetic ring is sleeved on the peripheral part of the magnet, and the magnet pole direction of the magnetic ring is opposite to that of the magnet. The area of the vertical projection of the magnetic ring on the substrate is smaller than that of the magnet on the substrate. A first insulating layer is arranged between the adsorption layer and the pin layer, and a second insulating layer is arranged between the adsorption layer and the pad layer.

2. The LED display module of claim 1, wherein, The side of the substrate close to the LED light-emitting chip is concave with a plurality of accommodating positions, the electrode is provided with a convex part matched with the accommodating position, and the convex part is located in the accommodating position.

3. The LED display module according to any of claims 1-2, characterized in that, The accommodating position is a semispherical recess, and the convex part is a semispherical protrusion.

4. The LED display module of claim 3, wherein, A tin layer is arranged between the convex part and the pad, and the convex part is connected with the pad through the tin layer.

5. The LED display module of claim 3, wherein, The application relates to a substrate and a plurality of array-arranged LED light-emitting chips.

6. A method of manufacturing an LED display module, characterized by, The substrate comprises a pin layer, an adsorption layer and a pad layer, the pin layer and the pad layer are respectively located on two sides of the adsorption layer, and the substrate is divided into a plurality of sub-pixel regions corresponding to the plurality of LED light-emitting chips. The adsorption layer comprises a plurality of magnets and insulators, the insulators are located between two adjacent magnets, and the magnet pole directions of the magnets are perpendicular to the substrate. Each sub-pixel region comprises two magnets, and the magnet pole directions of the two magnets are opposite. The plurality of sub-pixel regions are array-arranged along X and Y directions, the X direction is perpendicular to the Y direction, at least two magnets in the sub-pixel region are arranged along the X direction. The magnet pole directions of two adjacent magnets along the Y direction are opposite. The adsorption layer further comprises a magnetic ring, the magnetic ring is sleeved on the peripheral part of the magnet, and the magnet pole direction of the magnetic ring is opposite to that of the magnet. The area of the vertical projection of the magnetic ring on the substrate is smaller than that of the magnet on the substrate. A first insulating layer is arranged between the adsorption layer and the pin layer, and a second insulating layer is arranged between the adsorption layer and the pad layer. The side of the substrate close to the LED light-emitting chip is concave with a plurality of accommodating positions, the electrode is provided with a convex part matched with the accommodating position, and the convex part is located in the accommodating position. The accommodating position is a semispherical recess, and the convex part is a semispherical protrusion. A tin layer is arranged between the convex part and the pad, and the convex part is connected with the pad through the tin layer. The LED light emitting chip is fixed in the sub-pixel area, wherein the LED light emitting chip comprises two electrodes with magnetism, the two electrodes are located on the same side of the LED light emitting chip, the magnetic pole directions of the two electrodes are opposite, the LED light emitting chip is fixed on the pad layer by the adsorption of the electrodes and the magnet, and the electrodes are connected with the pads; The adsorption layer further comprises a magnetic ring, the magnetic ring is sleeved on the peripheral portion of the magnet, and the magnetic pole direction of the magnetic ring is opposite to the magnetic pole direction of the magnet; The area of the vertical projection of the magnetic ring on the substrate is smaller than the area of the vertical projection of the magnet on the substrate.

7. The method of claim 6, wherein the LED display module is prepared by the steps of: forming a plurality of LED display modules by the method of claim 1; and combining the plurality of LED display modules. First and second insulating layers are further formed on the opposite sides of the adsorption layer.

8. The method of claim 6, wherein the LED display module is prepared by the steps of: forming a plurality of LED display modules by the method of claim 1; and combining the plurality of LED display modules. The adsorption plate further comprises magnetic rings arranged at intervals with the magnets, and the adsorption plate comprises: A carrier is provided; A magnetic layer is formed on the carrier; Part of the magnetic layer is removed, and a plurality of magnets and magnetic rings are formed on the carrier, and the magnets and the magnetic rings are arranged at intervals.

9. The method of claim 6, wherein the LED display module is prepared by the steps of: forming a plurality of LED display modules by the method of claim 1; and combining the plurality of LED display modules. The adsorption plate further comprises a magnetic ring sleeved on the peripheral portion of the magnet, and the magnetic pole direction of the magnetic ring is opposite to the magnetic pole direction of the magnet, and the adsorption plate comprises: A first carrier is provided; A magnetic layer is formed on the first carrier; Part of the magnetic layer is removed, and a plurality of magnets are formed on the first carrier; A second carrier is provided; A magnetic layer is formed on the second carrier; Part of the magnetic layer is removed, and a plurality of magnetic rings are formed on the second carrier; The first carrier with the magnets and the second carrier with the magnetic rings are attached to each other, so that the magnets are nested in the magnetic rings; The second carrier is removed, and the adsorption plate is obtained.

10. The method of claim 6, wherein the LED display module is prepared by the steps of: forming a plurality of LED display modules by the method of claim 1; and combining the plurality of LED display modules. The side of the substrate close to the LED light emitting chip is recessed with a plurality of accommodating positions, and the electrodes of the LED light emitting chip are provided with protrusions matched with the accommodating positions, and after removing one of the carriers, the method further comprises: Part of the magnet is removed, and an accommodating position is formed at the end of the magnet away from the carrier.

11. The method for manufacturing an LED display module according to claim 10, characterized in that, The LED light emitting chip is fixed in the sub-pixel area, comprising: A layer of tin paste is coated on the surface of the protrusion; The LED light emitting chip is fixed in the sub-pixel area; The tin paste is heated to melt the tin paste, and a tin layer is formed between the protrusion and the pad, and the protrusion and the pad are connected through the tin layer.

12. A display device, characterized by comprising: The LED display module comprises any one of claims 1-5.

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