LED weakening structure and preparation method thereof

Abstract

The application discloses an LED weakening structure and a preparation method thereof. The LED weakening structure comprises a substrate, an auxiliary layer located on one side of the substrate, the auxiliary layer comprising a plurality of auxiliary structures and a plurality of grooves, a plurality of LED units located on the side of the auxiliary layer away from the substrate, the LED units being located in the grooves and not in contact with the surfaces of the grooves, and a connecting structure arranged between adjacent LED units, the connecting structure and the auxiliary structure being at least partially overlapped and at least partially in contact in the direction perpendicular to the substrate. In the process of transferring the LED units, the auxiliary structure is arranged in contact with the connecting structure between adjacent LED units, the breaking of the connecting structure is controlled, the residual of the connecting structure is reduced, and the yield of the LED unit transfer is improved.

Description

Technical Field

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

[0002] Micro LEDs are self-emissive display devices. As all-solid-state LEDs, they have the characteristics of long lifespan, high brightness, low power consumption, small size, and ultra-high resolution, and can be used in extreme environments such as high temperature or radiation.

[0003] However, due to the manufacturing process of Micro-LED, there is a core technical challenge in the industrialization of Micro-LED, namely the mass transfer problem. This leads to high transfer difficulty and low yield, which in turn seriously affects the display effect of the display panel formed by Micro-LED. Summary of the Invention

[0004] This invention provides an LED weakening structure and its preparation method to improve the transfer yield of LEDs.

[0005] In a first aspect, the present invention provides an LED attenuation structure, comprising:

[0006] Substrate;

[0007] An auxiliary layer, located on one side of the substrate, includes multiple auxiliary structures and multiple grooves;

[0008] Multiple LED units are located on the side of the auxiliary layer away from the substrate. The LED units are located within the groove and do not contact the surface of the groove.

[0009] A connection structure is provided between adjacent LED units. Along a direction perpendicular to the substrate, the connection structure at least partially overlaps with and at least partially contacts the auxiliary structure.

[0010] Secondly, embodiments of the present invention also provide a method for preparing an LED weakening structure, characterized in that the preparation method includes:

[0011] A growth substrate is provided, and a plurality of island-shaped structures are formed on one side of the growth substrate, with a first trench provided between adjacent island-shaped structures;

[0012] A sacrificial layer is prepared on the side of the island structure away from the growth substrate. The sacrificial layer includes a second trench embedded in the first trench.

[0013] An auxiliary layer is prepared, and a substrate is provided to be bonded to the auxiliary layer. The substrate is located on the side of the auxiliary layer away from the growth substrate. The auxiliary layer covers the island structure and fills the second trench. The auxiliary layer filling the second trench forms an auxiliary structure.

[0014] Remove the growth substrate, the island structure includes a buffer layer near the growth substrate, etch the buffer layer, and form an LED unit at the location of each island structure;

[0015] A connecting layer is fabricated to cover the LED units and a connecting structure is formed between adjacent LED units. Along a direction perpendicular to the substrate, the connecting structure at least partially overlaps with and at least partially contacts the auxiliary structure.

[0016] Removing the sacrificial layer causes the auxiliary layer to form a groove, the auxiliary structure surrounds the groove, and the LED unit is located within the groove and does not contact the surface of the groove.

[0017] The technical solution of this invention includes an LED weakening structure comprising a substrate; an auxiliary layer located on one side of the substrate, the auxiliary layer including multiple auxiliary structures and multiple grooves; multiple LED units located on the side of the auxiliary layer away from the substrate, the LED units being located within the grooves and not in contact with the surface of the grooves; and a connecting structure provided between adjacent LED units, along a direction perpendicular to the substrate, the connecting structure at least partially overlapping and at least partially contacting the auxiliary structure. This ensures that during LED unit transfer, the auxiliary structure contacts the connecting structure between adjacent LED units, controlling the breakage of the connecting structure, reducing the residue of the connecting structure, and improving the yield of LED unit transfer.

[0018] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of an LED weakening structure provided in an embodiment of the present invention;

[0021] Figure 2 This is a top view schematic diagram of an LED weakening structure provided in an embodiment of the present invention;

[0022] Figure 3 A top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0023] Figure 4 A top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0024] Figure 5 A top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0025] Figure 6 A top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0026] Figure 7 A top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0027] Figure 8 This is a schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of another LED weakening structure provided in an embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram of the process structure for preparing an LED weakening structure according to an embodiment of the present invention;

[0030] Figure 11 This is a schematic diagram of the LED weakening structure after step S101 provided in an embodiment of the present invention;

[0031] Figure 12 This is a schematic diagram of the LED weakening structure after step S102 provided in an embodiment of the present invention;

[0032] Figure 13 This is a schematic diagram of the LED weakening structure after step S1103 provided in an embodiment of the present invention;

[0033] Figure 14 This is a schematic diagram of the LED weakening structure after step S104 provided in an embodiment of the present invention;

[0034] Figure 15 This is a schematic diagram of the LED weakening structure after step S105 provided in an embodiment of the present invention;

[0035] Figure 16 This is a schematic diagram of the LED weakening structure after step S105 provided in an embodiment of the present invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0038] Figure 1 This is a schematic diagram of an LED weakening structure provided in an embodiment of the present invention. Figure 2 This is a top view schematic diagram of an LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 1 and Figure 2 As shown, the LED weakening structure 100 includes: a substrate 101; an auxiliary layer 102 located on one side of the substrate 101, the auxiliary layer 102 including a plurality of auxiliary structures 103 and a plurality of grooves 104; a plurality of LED units 105 located on the side of the auxiliary layer 102 away from the substrate 101, the LED units 105 being located within the grooves 104 and not in contact with the surface of the grooves 104; and a connecting structure 106 provided between adjacent LED units 105, along a direction perpendicular to the substrate 101 (as shown by the X direction in the figure), the connecting structure 106 at least partially overlapping with and at least partially contacting the auxiliary structures 103.

[0039] The substrate 101 can be a sapphire substrate or a silicon substrate, and the specific type can be selected according to actual design requirements. This embodiment of the invention does not impose specific limitations. The LED weakening structure 100 also includes multiple auxiliary structures 103 and grooves 104. The auxiliary structures 103 can be composed of organic materials, and the sidewalls of the auxiliary structures 103 are reused as the sidewalls of the grooves 104. The grooves 104 are used to place LED units 105, which can be micro-light-emitting elements such as sub-millimeter light-emitting diodes (Mini LEDs) or micro-light-emitting diodes (Micro LEDs). At the same time, the sidewall surface of the grooves 104 does not contact the LED units 105 to avoid damage to the LED units 105 and ensure the display effect of the LED units 105. A connecting structure 106 is provided between adjacent LED units 105. The connecting structure 106 is composed of inorganic materials, such as alumina, silicon oxide, silicon nitride, etc. The setting of the connecting structure 106 ensures that the mass transfer of multiple LED units 105 can be achieved by using a stamp transfer method. Simultaneously, along the direction X perpendicular to the substrate 101, the projections of the auxiliary structure 103 and the connecting structure 106 overlap and partially contact each other. The auxiliary structure 103 supports multiple LED units 105. During the mass transfer of LED units 105, when the polydimethylsiloxane (PDMS) stamp applies downward pressure to pick up the LED units 105, there are areas in the connecting structure 106 where the auxiliary structure 103 does not overlap with the connecting structure 106. These areas are easily subjected to external forces and may break, allowing each LED unit 105 to operate independently. This, in turn, enables the mass transfer of LED units 105 under the drive of the stamp transfer head, forming a display panel. Furthermore, the areas in the connecting structure 106 where the auxiliary structure 103 does not overlap with the connecting structure can be patterned to form a hollow structure 107. The hollow structure 107 penetrates the connecting structure 106, making the connecting structure 106 more prone to breakage under external forces, thus ensuring the effective transfer of LED units.

[0040] This invention improves the yield of LED unit transfer by setting an auxiliary structure in the LED weakening structure and setting a connecting structure between adjacent LED units. During the LED unit transfer process, the auxiliary structure contacts the connecting structure between adjacent LED units, thereby controlling the breakage of the connecting structure and reducing the residue of the connecting structure.

[0041] Optional, continue to refer to Figure 2 The connecting structure 106 is provided with at least one hollow structure 107, which is staggered from the auxiliary structure 103 along the X direction perpendicular to the substrate 101.

[0042] Specifically, by setting a connecting structure 106 between adjacent LED units 105 and setting a hollow structure 107 on the connecting structure 106, the hollow structure 107 is set on the side close to the LED unit 105, and the auxiliary structure 103 is set in the middle area of ​​adjacent LED units 105. Along the direction X perpendicular to the substrate 101, the hollow structure 107 and the auxiliary structure 103 are staggered. During the mass transfer of LED units 105, when the polydimethylsiloxane (PDMS) stamp applies downward pressure to pick up the LED units 105, the connecting structure 106 is subjected to external force, making the area where the hollow structure 107 exists a stress concentration area, which is prone to breakage, thereby realizing the transfer of LED units 105. At the same time, by reasonably setting the number, shape and position of the hollow structure 107, the residue of the connecting structure 106 on the LED unit 105 is reduced, thereby ensuring the display effect of the display panel composed of LED units 105.

[0043] Optional, Figure 3 This is a top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention. Figure 4 This is a top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 2 , Figure 3 and Figure 4 As shown, the shape of the hollow structure 107 includes at least one of the following: rectangle, triangle, circle, or ellipse.

[0044] For example, such as Figure 2 As shown, the hollow structure 107 is rectangular in shape; as Figure 3 As shown, the hollow structure 107 is triangular in shape; as Figure 4 As shown, the hollow structure 107 is circular in shape; the shape of the hollow structure 107 can be selected according to actual design requirements, and the embodiments of the present invention do not impose specific limitations.

[0045] Optional, Figure 5 This is a top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the hollow structure 107 includes multiple sub-hollow structures 108 located between the auxiliary structure 103 and the LED unit 105.

[0046] After the LED unit 105 is transferred, the hollow structure 107 is set to reduce the residue of the connecting structure 106 on each LED unit 105. Multiple sub-hollow structures 108 can be set on the connecting structure 106. For example, the figure shows two sub-hollow structures 108 set in the same column. The number and arrangement of the sub-hollow structures 108 are reasonably set so that when the polydimethylsiloxane (PDMS) stamp applies downward pressure to pick up the LED unit 105, it is easy for it to break at the sub-hollow structure 108, thus ensuring the picking effect of the LED unit 105.

[0047] Optional, Figure 6 This is a top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention. Figure 7 This is a top view schematic diagram of another LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 6 and Figure 7 As shown, along the direction X1 from the auxiliary structure 103 to the LED unit 105, the sum of the coverage areas of the sub-hollow structures 108 per unit area gradually increases.

[0048] In this process, along the direction X1 from the auxiliary structure 103 to the LED unit 105, the sum of the coverage areas of the sub-cutout structures 108 within a unit area gradually increases. This can be achieved by gradually varying the size or distribution density of the sub-cutout structures 108. For example... Figure 6 and Figure 7 The sub-cutout structure 108 is circular in shape as an example. In order to ensure that the influence of external stress gradually increases along the direction X1 from the auxiliary structure 103 to the LED unit 105, and at the same time, during the transfer of the LED unit 105, the residual of the connecting structure 106 on each LED unit 105 is reduced, the coverage area of ​​the sub-cutout structure 108 is controlled, the transfer effect of the LED unit 105 is guaranteed, and thus the display effect of the display panel is guaranteed.

[0049] Optional, continue to refer to Figure 6 Along the direction X1 from the auxiliary structure 103 to the LED unit 105, the coverage area of ​​the sub-hollow structure 108 gradually increases.

[0050] When the distribution density of the sub-hollow structures 108 is the same, by adjusting the coverage area of ​​the sub-hollow structures 108, the sum of the coverage areas of the sub-hollow structures 108 per unit area gradually increases along the direction X1 from the auxiliary structure 103 to the LED unit 105. Specifically, this allows the coverage area of ​​the sub-hollow structures to gradually increase along the direction X1 from the auxiliary structure 103 to the LED unit 105. During the transfer of the LED unit 105, the external force on the connecting structure 106 at the location with a larger coverage area of ​​the sub-hollow structures 108 gradually increases, making it more prone to breakage. Figure 6 As shown, for the setting of multiple columns of sub-cutout structures 108, the number of sub-cutout structures 108 in each column is the same. The coverage area of ​​each column of sub-cutout structures 108 is controlled to gradually increase, so that along the direction X1 from the auxiliary structure 103 to the LED unit 105, the coverage area of ​​the sub-cutout structures 108 gradually increases, ensuring the transfer effect of the LED unit 105, reducing the residue of the connecting structure 106 on each LED unit 105, and thus ensuring the display effect of the display panel.

[0051] Optional, continue to refer to Figure 7 Along the direction X1 from the auxiliary structure 103 to the LED unit 105, the distribution density of the sub-hollow structure 108 gradually increases.

[0052] When the coverage area of ​​the sub-cutout structures 108 is the same, by adjusting the distribution density of the sub-cutout structures 108, the sum of the coverage areas of the sub-cutout structures 108 per unit area along the direction X1 from the auxiliary structure 103 to the LED unit 105 gradually increases. Specifically, this can be achieved by gradually increasing the distribution density of the sub-cutout structures 108 along the direction X1 from the auxiliary structure 103 to the LED unit 105, i.e. Figure 7 As shown, for the multiple rows of sub-cutout structures 108, the number of sub-cutout structures 108 in each row is the same. The spacing between adjacent rows of sub-cutout structures 108 is adjusted so that in the direction X1 from the auxiliary structure 103 to the LED unit 105, during the transfer of the LED unit 105, the external force on the connecting structure 106 at the position with a higher distribution density of the sub-cutout structures 108 gradually increases, making it more prone to breakage. This causes the distribution density of the sub-cutout structures 108 to gradually increase in the direction X1 from the auxiliary structure 103 to the LED unit 105, ensuring the transfer effect of the LED unit 105, reducing the residue of the connecting structure 106 on each LED unit 105, and thus ensuring the display effect of the display panel 100.

[0053] Optional, Figure 8 This is a schematic diagram of another LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 8 As shown, the auxiliary structure 103 includes at least a first auxiliary structure 109 and a second auxiliary structure 110 that are spaced apart in the same direction. The first auxiliary structure 109 is in contact with the connecting structure 106 and is located in the direction X perpendicular to the substrate 101. The height h1 of the first auxiliary structure 109 is greater than the height h2 of the second auxiliary structure 110.

[0054] The auxiliary structure 103 includes a first auxiliary structure 109 and a second auxiliary structure 110 spaced apart in the same direction. That is, multiple auxiliary structures are spaced apart between adjacent LED units 105. During the transfer of LED units 105, when the polydimethylsiloxane (PDMS) stamp applies downward pressure to pick up the LED units 105, the first auxiliary structure 109 contacts the connecting structure 106. At the same time, along the direction X perpendicular to the substrate 101, the height h1 of the first auxiliary structure 109 is greater than the height h2 of the second auxiliary structure 110. This causes the connecting structure 106 to be subjected to an upward reaction force from the second auxiliary structure 110, which causes the connecting structure 106 to break under the reaction force. This improves the yield of LED unit 105 transfer and thus ensures the display effect of the display panel.

[0055] Optional, continue to refer to Figure 8 The second auxiliary structure 110 is located on the side of the first auxiliary structure 109 close to the LED unit 105, and the second auxiliary structure 110 does not contact the LED unit 105.

[0056] The second auxiliary structure 110 is located between the first auxiliary structure 109 and the LED unit 105, along a direction perpendicular to the substrate 101. The height of the first auxiliary structure 109 is greater than the height of the second auxiliary structure 110. Simultaneously, the second auxiliary structure 110 is controlled to prevent contact between the LED unit 105 and the LED unit 105. During the transfer of the LED unit 105, this ensures the breakage effect of the connection structure 106 between adjacent LED units 105, while preventing damage to the LED unit 105 during the transfer process, thus avoiding impact on the display effect. Furthermore, by controlling the spacing between the second auxiliary structure 110 and the LED unit 105, the breakage position of the connection structure 106 is adjusted, thereby affecting the residue of the connection structure 106 on the LED unit 105, ensuring the transfer yield of the LED unit 105, and the display effect of the display panel formed by the LED units.

[0057] Optional, Figure 9 This is a schematic diagram of another LED weakening structure provided in an embodiment of the present invention, as shown below. Figure 9 As shown, the LED unit 105 includes a first LED unit 111 and a second LED unit 112 located on both sides of the same first auxiliary structure 109. The second auxiliary structure 110 includes a first sub-auxiliary structure 1101 and a second sub-auxiliary structure 1102. The first sub-auxiliary structure 1101 is adjacent to the first LED unit 111 but not in contact with it, and the second sub-auxiliary structure 1102 is adjacent to the second LED unit 112 but not in contact with it. The first sub-auxiliary structure 1101, the first auxiliary structure 109 and the second sub-auxiliary structure 1102 are arranged sequentially along the direction from the first LED unit 111 to the second LED unit 112.

[0058] In this configuration, a first LED unit 111 and a second LED unit 112 are respectively disposed on both sides of the same first auxiliary structure 109. The first LED unit 111 and the second LED unit 112 are adjacent LED units. A first sub-auxiliary structure 1101 is disposed between the first auxiliary structure 109 and the first LED unit 111, and the first sub-auxiliary structure 1101 does not contact the first LED unit 111. A second sub-auxiliary structure 1102 is disposed between the first auxiliary structure 109 and the second LED unit 112, and the second sub-auxiliary structure 1102 does not contact the second LED unit 112. Furthermore, along the direction from the first LED unit 111 to the second LED unit 112, the first sub-auxiliary structure 1101, the first auxiliary structure 109, and the second sub-auxiliary structure... 1102 is arranged sequentially, that is, the first sub-auxiliary structure 1101, the first auxiliary structure 109 and the second sub-auxiliary structure 1102 are located on the same straight line, so that the first sub-auxiliary structure 1101 and the second sub-auxiliary structure 1102 can cause the connection structure 106 between the first LED unit 111 and the second LED unit 112 to break during the transfer of LED units, so as to ensure the transfer effect of each LED unit. At the same time, the spacing between the first sub-auxiliary structure 1101 and the first LED unit 111 and the spacing between the second sub-auxiliary structure 1102 and the second LED unit 112 are reasonably controlled, thereby reducing the residual connection structure 106 on the first LED unit 111 and the second LED unit 112, and ensuring the display effect of the display panel composed of LED units 105.

[0059] Optional, continue to refer to Figure 9 Along the direction X perpendicular to the substrate 101, the height h21 of the first sub-auxiliary structure 1101 is equal to the height h22 of the second sub-auxiliary structure 1102.

[0060] To ensure that the reaction forces received by the first sub-auxiliary structure 1101 and the second sub-auxiliary structure 1102 are the same when the pressure is applied downward by the polydimethylsiloxane (PDMS) stamp to pick up the LED unit 105, the height of the first sub-auxiliary structure 1101 and the height of the second sub-auxiliary structure 1102 can be controlled to be the same along the direction X perpendicular to the substrate 101. This makes the force uniform when the connection structure 106 between the first LED unit 111 and the second LED unit 112 breaks, while reducing the residue of the connection structure 106 on the LED unit 105, improving the yield of LED unit 105 transfer, and ensuring the display effect of the display panel composed of LED units 105.

[0061] Figure 10 This is a schematic diagram of the process structure for preparing an LED weakening structure according to an embodiment of the present invention, as shown below. Figure 10As shown, this preparation method is applied to the preparation of the LED weakening structure in the above embodiments. The specific preparation method includes:

[0062] S101 provides a growth substrate, on which multiple island-shaped structures are formed, and a first trench is provided between adjacent island-shaped structures.

[0063] in, Figure 11 This is a schematic diagram of the LED weakening structure after step S101 provided in an embodiment of the present invention, as shown below. Figure 11 As shown, the growth substrate 200 can be a silicon substrate or a sapphire substrate. Multiple island structures 201 are formed on one side of the growth substrate 200. Each island structure 201 includes at least an N-type barrier layer, a quantum well layer, a P-type barrier layer, a buffer layer, a current diffusion layer, and an electrode. A first trench 202 is provided between adjacent island structures 201. The island structures 201 and the first trench 202 share a sidewall. The first trench 202 is used to accommodate auxiliary structures in the future.

[0064] S102, Prepare a sacrificial layer. Prepare a sacrificial layer on the side of the island structure away from the growth substrate. The sacrificial layer includes a second trench, which is embedded in the first trench.

[0065] in, Figure 12 This is a schematic diagram of the LED weakening structure after step S102 provided in an embodiment of the present invention, as shown below. Figure 12 As shown, a sacrificial layer 203 is prepared on the side of the island structure 201 away from the growth substrate 200 using a spin coating method. The sacrificial layer 203 can be removed later. A second trench 204 is formed on the sacrificial layer 203 so that the second trench 204 is embedded in the first trench 202. The shape of the second trench 204 can facilitate the filling of the auxiliary layer material, so as to form an auxiliary structure of a predetermined shape.

[0066] S103, prepare an auxiliary layer and provide a substrate to bond with the auxiliary layer. The substrate is located on the side of the auxiliary layer away from the growth substrate. The auxiliary layer covers the island structure and fills the second trench. The auxiliary layer filling the second trench forms an auxiliary structure.

[0067] in, Figure 13 This is a schematic diagram of the LED weakening structure after step S1103 provided in an embodiment of the present invention, as shown below. Figure 13As shown, the auxiliary layer 102 can be composed of organic materials, and a substrate 101 is disposed on the side of the auxiliary layer 102 away from the growth substrate 200. The substrate 101 can be a silicon substrate or a sapphire substrate. The specific material of the substrate 101 can be selected according to actual design requirements, and the embodiments of the present invention do not impose specific limitations. The constituent materials of the auxiliary layer 102 fill the patterned second trench 204, thereby forming an auxiliary structure 103. At the same time, the auxiliary layer 102 is disposed as a whole layer. Along the direction perpendicular to the substrate, the auxiliary layer 102 covers the island-shaped structure 201, which facilitates the subsequent mass transfer of LED units 105 with the help of the auxiliary structure 103.

[0068] S104, Remove the growth substrate. The island structure includes a buffer layer near the growth substrate. Etch the buffer layer and form an LED unit at the location of each island structure.

[0069] in, Figure 14 This is a schematic diagram of the LED weakening structure after step S104 provided in an embodiment of the present invention, as shown below. Figure 14 As shown, the growth substrate 200 and the island structure 201 are separated by laser. The growth substrate 200 is removed, and the buffer layer 205 on the side close to the growth substrate 200 is etched to expose the buffer layer 205 on the side of the island structure 201 close to the substrate. This allows each island structure 201 to form an LED unit 105, which is convenient for subsequent transfer.

[0070] S105, a connecting layer is fabricated to cover the LED unit and a connecting structure is formed between adjacent LED units. Along the direction perpendicular to the substrate, the connecting structure and the auxiliary structure at least partially overlap and at least partially contact each other.

[0071] in, Figure 15 This is a schematic diagram of the LED weakening structure after step S105 provided in an embodiment of the present invention, as shown below. Figure 15 As shown, the connecting layer 206 can be composed of inorganic materials such as alumina, silicon oxide, and silicon nitride. The connecting layer 206 is fabricated on the side of the LED unit 105 away from the substrate. The connecting layer 206 is a continuous layer, perpendicular to the substrate, covering each LED unit 105. Connecting structures 106 are formed between adjacent LED units 105, and the connecting structures 106 at least partially overlap and contact the auxiliary structure 103. This facilitates the transfer of LED units 105, allowing the auxiliary structure 103 to break the connecting structure 106, enabling mass transfer of LED units 105, controlling the shape of the auxiliary structure 103, reducing the residue of the connecting structure 106 on the LED units 105, and ensuring a high transfer yield.

[0072] S106, the sacrificial layer is removed to form a groove in the auxiliary layer, the auxiliary structure surrounds the groove, the LED unit is located in the groove and does not contact the surface of the groove.

[0073] in, Figure 16 This is a schematic diagram of the LED weakening structure after step S105 provided in an embodiment of the present invention, as shown below. Figure 16 As shown, the sacrificial layer 203 can be removed by plasma etching or chemical etching. After the sacrificial layer 203 is removed, the auxiliary layer 102 forms a groove 104. The groove 104 surrounds the auxiliary structure 103. Since the LED unit 105 is located in the groove 104 and does not contact the surface of the groove 104, it is convenient to be subjected to external force when the LED unit 105 is transferred. The auxiliary structure 103 causes the connection structure 106 between adjacent LED units 105 to break, realizing the mass transfer of LED units 105.

[0074] This invention achieves mass transfer of LED units by rationally setting the positional relationship between LED units, auxiliary structures, and connecting structures, while avoiding excessive residue of connecting structures on LED units, ensuring transfer yield, and guaranteeing the display effect of the display panel formed by the LED units.

[0075] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An LED weakening structure, characterized in that, include: Substrate; An auxiliary layer, located on one side of the substrate, includes multiple auxiliary structures and multiple grooves; Multiple LED units are located on the side of the auxiliary layer away from the substrate. The LED units are located within the groove and do not contact the surface of the groove. A connection structure is provided between adjacent LED units, and along the direction perpendicular to the substrate, the connection structure at least partially overlaps with and at least partially contacts the auxiliary structure; The connecting structure is provided with at least one hollow structure, and the hollow structure is staggered from the auxiliary structure along the direction perpendicular to the substrate. The hollow structure includes multiple sub-hollow structures located between the auxiliary structure and the LED unit; Along the direction from the auxiliary structure to the LED unit, the sum of the coverage areas of the sub-hollow structures per unit area gradually increases.

2. The LED weakening structure according to claim 1, characterized in that, Along the direction from the auxiliary structure to the LED unit, the coverage area of ​​the sub-hollow structure gradually increases.

3. The LED weakening structure according to claim 1, characterized in that, Along the direction from the auxiliary structure to the LED unit, the distribution density of the sub-hole structure gradually increases.

4. The LED weakening structure according to claim 1, characterized in that, The shape of the hollow structure includes at least one of the following: rectangle, triangle, circle, or ellipse.

5. The LED weakening structure according to claim 1, characterized in that, The auxiliary structure includes at least a first auxiliary structure and a second auxiliary structure spaced apart in the same direction. The first auxiliary structure is in contact with the connecting structure and is perpendicular to the substrate. The height of the first auxiliary structure is greater than the height of the second auxiliary structure.

6. The LED weakening structure according to claim 5, characterized in that, The second auxiliary structure is located on the side of the first auxiliary structure closer to the LED unit, and the second auxiliary structure does not contact the LED unit.

7. The LED weakening structure according to claim 6, characterized in that, The LED unit includes a first LED unit and a second LED unit located on both sides of the same first auxiliary structure. The second auxiliary structure includes a first sub-auxiliary structure and a second sub-auxiliary structure. The first sub-auxiliary structure is adjacent to the first LED unit but not in contact with it, and the second sub-auxiliary structure is adjacent to the second LED unit but not in contact with it. The first sub-auxiliary structure, the first auxiliary structure and the second sub-auxiliary structure are arranged sequentially along the direction from the first LED unit to the second LED unit.

8. The LED weakening structure according to claim 7, characterized in that, Along a direction perpendicular to the substrate, the height of the first sub-auxiliary structure is equal to the height of the second sub-auxiliary structure.

9. A method for preparing an LED weakening structure, characterized in that, The preparation method is used to prepare the LED weakening structure according to any one of claims 1-8, and the preparation method includes: A growth substrate is provided, and a plurality of island-shaped structures are formed on one side of the growth substrate, with a first trench provided between adjacent island-shaped structures; A sacrificial layer is prepared on the side of the island structure away from the growth substrate. The sacrificial layer includes a second trench embedded in the first trench. An auxiliary layer is prepared, and a substrate is provided to be bonded to the auxiliary layer. The substrate is located on the side of the auxiliary layer away from the growth substrate. The auxiliary layer covers the island structure and fills the second trench. The auxiliary layer filling the second trench forms an auxiliary structure. Remove the growth substrate, the island structure includes a buffer layer near the growth substrate, etch the buffer layer, and form an LED unit at the location of each island structure; A connecting layer is fabricated to cover the LED units and a connecting structure is formed between adjacent LED units. Along a direction perpendicular to the substrate, the connecting structure at least partially overlaps with and at least partially contacts the auxiliary structure. Removing the sacrificial layer causes the auxiliary layer to form a groove, the auxiliary structure surrounds the groove, and the LED unit is located within the groove and does not contact the surface of the groove.

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