Mass transfer tool and mass transfer method

Abstract

This invention relates to a mass transfer fixture and a mass transfer method. The mass transfer fixture includes a fixture body having a first surface and a second surface facing away from each other. A hollow cavity is disposed on the fixture body, extending from the first surface to the second surface. A bearing surface is formed within the hollow cavity, or the first surface serves as the bearing surface. The distance between the bearing surface and the second surface is greater than a threshold value. The mass transfer fixture of this invention ensures that there is no interference between the micro-light-emitting diodes on the native substrate and the micro-light-emitting diodes on the target substrate during transfer.

Description

Technical Field

[0001] This invention relates to display panel manufacturing technology, and more particularly to a mass transfer fixture and mass transfer method. Background Technology

[0002] In micro LED manufacturing technology, the mass transfer of micro LEDs is the most critical technology. During the transfer, micro LEDs of the three primary colors of blue, green and red need to be transferred from their respective native substrates (WAFER) to the target substrate. The target substrate is divided into multiple pixel areas, and each pixel area needs to be transferred with LEDs of the three primary colors to achieve full-color display function.

[0003] Once one or two primary color LEDs have been transferred to the target substrate, interference may occur between the remaining primary color LEDs and the target substrate during the transfer process. Only by placing the original substrate and the target substrate at a certain distance and separating them can we ensure that the LEDs on the original substrate and the LEDs on the target substrate do not interfere with each other during the transfer process.

[0004] Existing transfer devices can transfer a native substrate onto a target substrate, but it is difficult to precisely control the spacing between the two substrates during the transfer process, making it impossible to ensure that the micro-LEDs on the native substrate and the target substrate do not interfere with each other. Therefore, ensuring that the micro-LEDs on the native substrate and the target substrate do not interfere with each other is an urgent problem to be solved. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a mass transfer fixture and a mass transfer method, which aims to solve the problem that existing transfer devices cannot ensure that the native substrate and the target substrate do not interfere with each other.

[0006] This invention provides a mass transfer fixture, comprising:

[0007] The fixture body has a first surface and a second surface that are opposite to each other;

[0008] A hollow chamber is disposed on the fixture body and extends from the first surface to the second surface; and

[0009] The hollow cavity contains a bearing surface or the first surface is a bearing surface, and the distance between the bearing surface and the second surface is greater than a threshold.

[0010] In the mass transfer fixture of the present invention, since a carrier surface for carrying micro light-emitting diodes is provided, and the distance between the carrier surface and the second surface is greater than a threshold, the native substrate and the target substrate can be precisely separated by the distance, which can ensure that the micro light-emitting diodes on the native substrate and the micro light-emitting diodes on the target substrate do not interfere with each other during transfer.

[0011] The hollow cavity includes a receiving cavity and a transfer cavity arranged sequentially along the direction from the first surface to the second surface. The receiving cavity has at least one limiting profile, each limiting profile including:

[0012] At least one of the aforementioned bearing surfaces is used to support a native substrate on which micro-light-emitting diodes are grown, wherein the native substrate is a polygonal substrate; and

[0013] Multiple sides are connected to the bearing surface, and each side is used to limit the edge of the original substrate.

[0014] Optionally, the accommodating cavity has only one limiting profile, the hollow cavity is a stepped cavity, and the bearing surface is the stepped surface of the stepped cavity.

[0015] Optionally, the accommodating cavity has at least two limiting contours, and in any one of the limiting contours, two adjacent sides intersect to form a limiting angle;

[0016] The bearing surfaces of each of the limiting contours are distributed at different depths of the accommodating cavity, and the limiting angles of each of the limiting contours are staggered on the cavity wall of the accommodating cavity.

[0017] Optionally, each of the limiting contours has a geometric center line located at the same position, and each of the limiting contours has a deflection angle centered on the geometric center line.

[0018] Optionally, in each of the limiting contours, at least two limiting contours have parallel geometric center lines that do not overlap, any two limiting contours have a deflection angle, and any two limiting contours share a common space.

[0019] Optionally, the distance between the bearing surface and the second surface ranges from 20µm to 80µm.

[0020] Optionally, the fixture body is made of a substrate material, which is one of silicon, sapphire, silicon carbide, gallium nitride, gallium arsenide, and indium phosphide.

[0021] Based on the same inventive concept, the present invention also provides a mass transfer method, comprising:

[0022] Provide a mass transfer fixture as described above;

[0023] A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate;

[0024] Provide a native substrate on which micro light-emitting diodes are grown;

[0025] The mass transfer fixture is placed on the target substrate, with the second surface contacting the target substrate, and the hollow chamber aligned with the target transfer area;

[0026] The native substrate is transferred to the carrier surface, such that the side of the native substrate on which the micro-light-emitting diodes are grown faces the same target transfer area;

[0027] The micro-LEDs to be transferred are removed from the native substrate by laser, causing the micro-LEDs to fall onto the corresponding electrode pads in the target transfer area.

[0028] This mass transfer method can use the mass transfer fixture to separate the native substrate and the target substrate by a distance greater than a threshold during the mass transfer process, thereby avoiding interference between the micro-LEDs on the native substrate and the micro-LEDs on the target substrate.

[0029] Based on the same inventive concept, the present invention also provides a mass transfer method, comprising:

[0030] Provide the aforementioned mass transfer fixture having the aforementioned limiting profile;

[0031] A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate;

[0032] Provide a native substrate on which micro light-emitting diodes are grown;

[0033] The mass transfer fixture is placed on the target substrate, with the second surface contacting the target substrate, and the hollow chamber aligned with the target transfer area;

[0034] The native substrate is transferred into the limiting contour so that the native substrate is placed on a bearing surface, and the corresponding plurality of the sides are limited at the edge of the native substrate, and the side on the native substrate on which the micro light-emitting diodes are grown faces the same target transfer area.

[0035] The micro-LEDs to be transferred are removed from the native substrate by laser, causing the micro-LEDs to fall onto the corresponding electrode pads in the target transfer area.

[0036] This mass transfer method uses a mass transfer fixture with a corresponding limiting contour, which not only avoids interference between the micro-LEDs on the native substrate and the micro-LEDs on the target substrate, but also allows the micro-LEDs on the native substrate to automatically align with the transfer cavity after the native substrate is placed into the limiting contour, which helps to improve the transfer efficiency.

[0037] Based on the same inventive concept, the present invention provides a mass transfer method, comprising:

[0038] Provide a mass transfer fixture with a profile having at least two of the aforementioned limits;

[0039] A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate;

[0040] Provide at least two native substrates on which micro-light-emitting diodes are grown, wherein the native substrates are monochrome native substrates and the micro-light-emitting diodes grown on each native substrate have different primary colors;

[0041] The mass transfer fixture is placed on the target substrate, with the second surface contacting the target substrate, and the hollow chamber aligned with the target transfer area;

[0042] Each of the original substrates is placed into different limiting contours so that each original substrate is placed on a different bearing surface. The corresponding multiple sides are limited at the edges of the original substrates. When any original substrate is placed into any limiting contour, the side of the original substrate with micro-light-emitting diodes (LEDs) faces the target transfer area. The micro-LEDs to be transferred on the original substrate are peeled off by laser so that the micro-LEDs fall onto the corresponding electrode pads of the target transfer area.

[0043] This mass transfer method employs a mass transfer fixture with at least two limiting contours, which not only avoids interference between the micro-LEDs on the native substrate and the micro-LEDs on the target substrate, but also allows the micro-LEDs on the native substrate to automatically align with the transfer cavity after the native substrate is placed into the limiting contours, thus improving transfer efficiency. Furthermore, using the same mass transfer fixture to transfer micro-LEDs of multiple primary colors helps reduce costs.

[0044] Optionally, the method for obtaining the native substrate of a single primary color is as follows: providing a substrate, growing a primary color micro-light-emitting diode on the substrate, and dividing the substrate to form multiple native substrates of corresponding primary colors.

[0045] Based on the same inventive concept, the present invention provides a method for manufacturing a mass transfer fixture, comprising:

[0046] A substrate is provided, the substrate having a first surface and a second surface facing away from each other;

[0047] A hollow cavity is formed on the substrate, the hollow cavity extends from the first surface to the second surface, a bearing surface is formed in the hollow cavity or the first surface is the bearing surface, and the distance between the bearing surface and the second surface is greater than a threshold.

[0048] The mass transfer fixture manufactured using this method forms a carrier surface for carrying micro-LEDs, and the distance between the carrier surface and the second surface is greater than a threshold, which allows the native substrate and the target substrate to be precisely separated by this distance. This ensures that the micro-LEDs on the native substrate and the micro-LEDs on the target substrate do not interfere with each other during transfer.

[0049] Optionally, a method for forming a hollow cavity on the substrate includes:

[0050] An accommodating cavity is formed by etching on the first surface. The accommodating cavity has at least one limiting profile, which includes a bottom surface for supporting the native substrate and multiple side surfaces for limiting the native substrate at its edge.

[0051] A transfer cavity is etched to form the bottom surface of the accommodating cavity, and the transfer cavity extends from the bottom surface of the accommodating cavity to the second surface.

[0052] Optionally, a method for forming a hollow cavity on the substrate includes:

[0053] A cavity is formed on the substrate, the cavity extending from the first surface to the second surface;

[0054] An accommodating cavity is etched on the first surface. The accommodating cavity has at least one limiting profile, which includes a bottom surface for supporting the native substrate and multiple side surfaces for limiting the native substrate at its edge.

[0055] Optionally, the method of forming the receiving cavity includes forming the limiting profile, and the method of forming a single limiting profile includes:

[0056] A mask layer with an etching window is formed on the first surface, the outline of which matches the outline of the original substrate.

[0057] The limiting contour is formed by photolithography of the substrate through the etching window at a preset depth, so that the gap is formed between the bottom surface of the limiting contour and the second surface.

[0058] Optionally, when forming at least two of the limiting contours, each limiting contour is formed one by one, and each limiting contour is formed by the method of forming a single limiting contour.

[0059] According to the formation order of each limiting contour, the corresponding etching window of the previous limiting contour and the corresponding etching window of the current limiting contour have a deflection angle, so that the edges of each window corresponding to each limiting contour are staggered, each etching window corresponding to each limiting contour has a common area, and the etching depth corresponding to each limiting contour is different.

[0060] Optionally, the spacing ranges from 20µm to 80µm.

[0061] Optionally, the cavity is formed by etching with a laser with a wavelength of 532 nm.

[0062] Optionally, the fixture body is made of a substrate material, which is one of silicon, sapphire, silicon carbide, gallium nitride, gallium arsenide, and indium phosphide.

[0063] Optionally, the cavity is formed by etching with a laser with a wavelength of 532 nm. Attached Figure Description

[0064] Figure 1 This is an exemplary structural schematic diagram of the mass transfer fixture of the present invention;

[0065] Figure 2 To adopt Figure 1 A schematic diagram of a mass transfer fixture performing mass transfer.

[0066] Figure 3 This is a schematic diagram illustrating an exemplary distribution of the regions to be transferred on the native substrate.

[0067] Figure 4 This is an exemplary distribution diagram of the target transfer regions on the target substrate;

[0068] Figure 5 This is another exemplary structural schematic diagram of the mass transfer fixture of the present invention;

[0069] Figure 6 This is another exemplary structural schematic diagram of the mass transfer fixture of the present invention;

[0070] Figure 7 for Figure 6 A schematic diagram showing the limiting contours of the mass transfer fixture in the diagram;

[0071] Figure 8 This is another exemplary structural schematic diagram of the mass transfer fixture of the present invention;

[0072] Figure 9 To adopt Figure 5 or Figure 6 or Figure 8A schematic diagram of a state during mass transfer using a mass transfer fixture;

[0073] Figure 10 To adopt Figure 6 or Figure 8 Another schematic diagram of the mass transfer fixture in the middle during mass transfer;

[0074] Figure 11 This is a schematic diagram showing the transfer of red, green, and blue light from the original substrate to the target substrate using red, green, and blue micro-LEDs.

[0075] Figure 12 This is a schematic diagram showing the transfer of a red micro-light-emitting diode from the native substrate to the target substrate;

[0076] Figure 13 This is a schematic diagram showing the transfer of green micro-light-emitting diodes from the native substrate to the target substrate;

[0077] Figure 14 This is a schematic diagram showing the transfer of blue micro-light-emitting diodes from the native substrate to the target substrate;

[0078] Figure 15 A schematic diagram for obtaining a native substrate by cutting a substrate;

[0079] Figure 16 A schematic diagram of the substrate provided for manufacturing mass transfer fixtures;

[0080] Figure 17 A schematic diagram of forming a mask layer on the first surface during the fabrication of a mass transfer fixture;

[0081] Figure 18 A schematic diagram for forming a limiting profile during the fabrication of a mass transfer jig.

[0082] Figure 19 A schematic diagram showing the formation of two limiting contours when creating a mass transfer fixture.

[0083] Explanation of reference numerals in the attached figures:

[0084] 100- Fixture body; 101- First surface; 102- Second surface; 110- Hollow cavity; 111- Accommodation cavity; 112- Transfer cavity; 111a- Bearing surface; 111b- Side side; 111c- Limiting angle; 100a- Substrate; 110b- Mask layer; 110c- Etching window;

[0085] 200 - Native substrate; 201 - Transfer area; Substrate - 200a;

[0086] 300 - Target substrate; 301 - Target transfer area; 310 - Pixel area;

[0087] 400 - Micro LED, 401 - Red micro LED, 402 - Green micro LED, 403 - Blue micro LED. Detailed Implementation

[0088] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0090] The main problem with existing solutions is that they cannot guarantee that the micro-LEDs on the native substrate and the micro-LEDs on the target substrate will not interfere with each other during the transfer process.

[0091] This application aims to provide a solution that can solve the above-mentioned technical problems, the details of which will be described in subsequent embodiments.

[0092] This application provides a mass transfer fixture; see [link to relevant documentation]. Figure 1 , Figures 5 to 8 The mass transfer fixture includes a fixture body 100 and a hollow chamber 110 disposed on the fixture body 100. The fixture body 100 has a first surface 101 and a second surface 102 facing away from each other. The hollow chamber 110 extends from the first surface 101 to the second surface 102. A bearing surface 111a is formed within the hollow chamber 110, or the first surface 101 is the bearing surface. The distance between the bearing surface and the second surface 102 is greater than a threshold value. For example, when the threshold value is 20 μm, the distance is greater than 20 μm.

[0093] In the mass transfer fixture of the present invention, since a carrier surface for carrying micro light-emitting diodes 400 is provided, and the distance between the carrier surface and the second surface 102 is greater than a threshold, the native substrate 200 and the target substrate 300 can be precisely separated by the distance, ensuring that the micro light-emitting diodes on the native substrate 200 and the micro light-emitting diodes on the target substrate 300 do not interfere with each other during transfer.

[0094] Accordingly, this application provides a mass transfer method, which is a method for transferring single-color micro-light-emitting diodes, see [link to relevant documentation]. Figure 2 , Figure 9 , Figure 10The method includes:

[0095] S100. A mass transfer fixture is provided, which may be the mass transfer fixture described above, or any of the following mass transfer fixtures.

[0096] S200: A target substrate 300 is provided, wherein a plurality of target transfer regions 301 are disposed on the target substrate 300. (See also...) Figure 4 ;

[0097] S300, provides a native substrate 200 on which micro-light-emitting diodes are grown,

[0098] S400: Place the mass transfer fixture on the target substrate 300, so that the second surface 102 contacts the target substrate 300, and align the hollow cavity 110 with a target transfer area 301;

[0099] S500, Transfer the native substrate 200 onto the bearing surface 111a, so that the side of the native substrate 200 on which the micro light-emitting diode 400 is grown faces the same target transfer area 301.

[0100] S600: The micro-light-emitting diodes to be transferred on the native substrate 200 are peeled off by laser, so that the peeled micro-light-emitting diodes fall onto the corresponding electrode pads of the target transfer area 301.

[0101] In actual implementation, see Figure 3 A transfer area 201 can be provided on the native substrate 200, and all micro light-emitting diodes 400 are provided in the transfer area 201. In step S500, when the side of the native substrate 200 on which the micro light-emitting diodes 400 are grown faces a target transfer area 301, it can be understood as the transfer area 201 of the native substrate 200 is facing a target transfer area 301.

[0102] In some embodiments of the present invention, see Figure 1 The first surface 101 is directly used as the bearing surface 111a. In the corresponding mass transfer method, see [link to relevant documentation]. Figure 2 In step S500, the native substrate 200 is transferred to the bearing surface 111a, that is, to the first surface 101.

[0103] In other embodiments of the invention, see Figures 5 to 10 The bearing surface 111a is disposed within the hollow cavity 110. The hollow cavity 110 includes a receiving cavity 111 and a transfer cavity 112 arranged sequentially along the direction from the first surface 101 to the second surface 102. The receiving cavity 111 has at least one limiting profile. Figure 5In the middle, the accommodating cavity 111 has a limiting profile K, Figures 6-8 In the middle, the accommodating cavity has a first limiting profile K1 and a second limiting profile K2.

[0104] Each limiting profile includes a bearing surface 111a and multiple side surfaces 111b. The bearing surface 111a is used to support the native substrate 200 on which micro-light-emitting diodes are grown. Each side surface 111b is connected to the corresponding bearing surface 111a and is used to limit the native substrate 200 at its corresponding edge. In the figures of this invention, the outline of the native substrate 200 is quadrilateral. Therefore, each limiting profile is provided with four side surfaces 111b. The four side surfaces 111b are used to limit the native substrate 200 at its four edges. In actual implementation, if the outline of the native substrate 200 is a triangle, hexagon, or other polygonal shape, the number of side surfaces 111b is equal to the number of edges of the native substrate 200, and they are limited at each edge of the native substrate 200 in a one-to-one correspondence.

[0105] This type of mass transfer fixture can not only separate the native substrate 200 and the target substrate 300 with precise spacing, but also restrict the position of the native substrate 200. When the native substrate 200 is placed into the corresponding limiting contour, the micro light-emitting diodes 400 on the native substrate 200 can automatically align with the transfer cavity 112.

[0106] When using this type of mass transfer fixture with a limiting profile for mass transfer, refer to [reference needed]. Figures 5 to 10 In step S500, "transferring the native substrate 200 to the bearing surface 111a" is achieved by transferring the native substrate 200 into the limiting contour. After the native substrate 200 is transferred into the limiting contour, not only is the native substrate 200 placed on the corresponding bearing surface 111a, but the corresponding multiple side surfaces 111b are also limited to the edge of the native substrate.

[0107] To achieve full-color display, see [link / reference]. Figures 11-14 The red LED 401, green LED 402, and blue LED 403 need to be selectively transferred from their respective native substrates 200 to the target substrate 300 in sequence. Each pixel area 310 needs to have one red LED 401, one green LED 402, and one blue LED 403 transferred accordingly; see [link to relevant documentation]. Figure 12 When transferring the red micro-LED 401 to the target substrate 300, a distance D1 needs to be maintained between the native substrate 200 and the target substrate 300 to avoid direct interference between the red micro-LED 401 and the target substrate 300; see [link to relevant documentation]. Figure 13When transferring the green micro-LED 402 onto the target substrate 300, to avoid interference between the green micro-LED 402 and the red micro-LED already transferred to the target substrate 300, a spacing D2 greater than D1 is maintained between the original substrate 200 and the target substrate 300; see [link to relevant documentation]. Figure 14 When transferring the blue micro-light-emitting diode to the target substrate 300, in order to avoid interference between the blue micro-light-emitting diode 403 and the green and red micro-light-emitting diodes that have been transferred to the target substrate 300, a distance D3 greater than D2 needs to be maintained between the original substrate 200 and the target substrate 300.

[0108] It should be noted that, for ease of understanding, the description of this invention may be described by sequentially changing the transfer order of the red micro-light-emitting diode 401, the green micro-light-emitting diode 402, and the blue micro-light-emitting diode 403. However, in application, this invention does not restrict the transfer order of the three primary colors of micro-light-emitting diodes, and the transfer order of each primary color can be arbitrarily changed.

[0109] In some embodiments of the present invention, see Figure 5 The accommodating cavity 111 has only one limiting contour K. The hollow cavity 110 is a stepped cavity, and the bearing surface 111a is the stepped surface of the stepped cavity. That is, the contour of the accommodating cavity 111 itself is the limiting contour. When transferring the three primary color micro-light-emitting diodes sequentially onto the target substrate 300, three jigs can be used respectively. The distance between the bearing surface 111a and the second surface 102 of the three jigs is not equal, so that the distance between the corresponding original substrate and the target substrate is different when transferring red micro-light-emitting diodes, green micro-light-emitting diodes, and blue micro-light-emitting diodes.

[0110] In other embodiments of the present invention, the receiving cavity 111 has at least two limiting contours, see [reference needed]. Figures 6-8 The accommodating cavity 111 has a first limiting contour K1 and a second limiting contour K2. In any limiting contour, two adjacent side surfaces 111b intersect to form a limiting angle 111c. The bearing surfaces 111a of each limiting contour are distributed at different depths within the accommodating cavity 111, and the limiting angles 111c of each limiting contour are staggered on the cavity wall of the accommodating cavity 111. This structure allows for the positioning of multiple primary color substrates 200 at positions with different distances from the target substrate 300 using only a single mass transfer fixture, enabling the transfer of micro-light-emitting diodes of at least two primary colors, thus reducing costs.

[0111] When using this mass transfer fixture with at least two limiting contours for mass transfer, at least two primary colors of light-emitting diodes can be transferred. The corresponding mass transfer method requires adjustment to step S300 in the aforementioned mass transfer method, and repetition of step S500, as follows:

[0112] In step S300, at least two native substrates on which micro-light-emitting diodes are grown are provided. The native substrates are monochrome native substrates, and the micro-light-emitting diodes grown on each native substrate have different primary colors.

[0113] In step S500, each of the original substrates is sequentially placed into different limiting contours (such as K1 and K2) so that each original substrate is placed on a different bearing surface 111a, and the corresponding plurality of side surfaces 111b are limited to the edges of the original substrates. When any original substrate is placed into any limiting contour, the side of the original substrate on which the micro-light-emitting diodes are grown faces the target transfer area. For example, combined with Figures 6 to 10 The original substrate of the previous primary color can be placed in the first limiting contour K1 first, and after the transfer is completed, it can be taken out, and then the original substrate of the current primary color can be placed in the second limiting contour K2.

[0114] For example, (not shown in the figure) in step S300, a mass transfer fixture with at least three limiting contours—a first limiting contour, a second limiting contour, and a third limiting contour—can be provided. The bearing surface of the first limiting contour is defined as the first bearing surface, the bearing surface of the second limiting contour is defined as the second bearing surface, and the bearing surface of the third limiting contour is defined as the third bearing surface. The distance between the first bearing surface and the second surface is less than the distance between the second bearing surface and the second surface, and the distance between the second bearing surface and the second bearing surface is less than the distance between the third bearing surface and the second surface. When transferring the red, green, and blue micro-LEDs from their respective native substrates to the target substrate in sequence, placing the red micro-LED within the first limiting contour, the green micro-LED within the second limiting contour, and the blue micro-LED within the third limiting contour can achieve positioning during the transfer process, ensuring that the micro-LEDs on the native substrate and the micro-LEDs on the target substrate do not interfere with each other, which is beneficial to improving the transfer reliability.

[0115] In some embodiments of the present invention, see Figure 7 Each of the aforementioned limiting contours has a geometric center line O located at the same position, and each of the aforementioned limiting contours has a deflection angle β centered on the geometric center line O. In other embodiments of the invention, at least two limiting contours have parallel and non-overlapping geometric center lines, any two of the aforementioned limiting contours have a deflection angle, and any two of the aforementioned limiting contours share a common space, for example, Figure 8In the middle, the center line O1 of the limiting profile K1 and the center line O2 of the limiting profile K2 are not collinear, and the limiting profiles K1 and K2 share a common space.

[0116] or

[0117] In some embodiments of the present invention, the distance between any two adjacent bearing surfaces 111a is equal. In actual implementation, the distance between any two adjacent bearing surfaces 111a may not be equal.

[0118] In some embodiments of the present invention, the distance between the bearing surface 111a and the second surface 102 ranges from 20 μm to 80 μm. This distance range helps to ensure that the two substrates do not contact each other and helps to ensure that the impact force generated by the laser acting on the gas released from the primary substrate can reliably transfer the micro-light-emitting diode from the primary substrate to the target substrate.

[0119] In some embodiments of the present invention, the fixture body 100 is made of a substrate material, which is one of silicon, sapphire, silicon carbide, gallium nitride, gallium arsenide, and indium phosphide. Using these substrate materials gives the fixture body 100 good flatness. In actual implementation, silicon wafers are preferably used to fabricate the mass transfer fixture, as silicon wafers have very good flatness, which is beneficial for separating the native substrate 200 and the target substrate 300 at a precise distance.

[0120] In some embodiments, see Figure 15 The method for obtaining the native substrate 200 is as follows: a native wafer 200a is provided, micro light-emitting diodes are grown on the native wafer 200a, and the native wafer 200a is divided to form a plurality of the native substrates 200.

[0121] In other words, the mass transfer method of the present invention does not directly transfer the micro-light-emitting diodes on the native wafer 200a to the target substrate 300. Instead, it cuts the native substrate 200 to form a native substrate and then transfers it to the target substrate 300. The overall flatness of the cut native substrate 200 is better than that of the native wafer 200a, which helps to reduce the defects caused by the warping of the native wafer 200a during the transfer process.

[0122] Accordingly, the mass transfer jig can be manufactured using the following method, which includes:

[0123] Step B100, see Figure 16 A substrate 100a is provided, the substrate 100a having a first surface 101 and a second surface 102 facing away from each other.

[0124] Step B200: A hollow cavity 110 is formed on the substrate 100a, such that the hollow cavity 110 extends from the first surface 101 to the second surface 102. A bearing surface 111a is formed within the hollow cavity 110, or the first surface 101 serves as the bearing surface 111a. The distance between the bearing surface 111a and the second surface 102 is greater than a threshold value. The resulting mass transfer fixture is described in [reference needed]. Figure 1 or Figures 5 to 8 .

[0125] The mass transfer fixture manufactured using this method has a bearing surface 111a for supporting the native substrate, and there is a gap between the bearing surface 111a and the second surface 102, which allows the native substrate 200 and the target substrate 300 to be precisely separated by this gap. This ensures that the micro-light-emitting diodes on the native substrate 200 and the micro-light-emitting diodes on the target substrate 300 do not interfere with each other during transfer.

[0126] In some embodiments, step B200, the method of forming the hollow cavity 110 on the substrate 200a includes:

[0127] Step B210: An accommodating cavity 111 is formed by etching on the first surface 101, see [link to relevant documentation]. Figure 18 or Figure 19 The accommodating cavity 111 has at least one limiting profile, which includes a bottom surface for supporting the native substrate 200 and a plurality of side surfaces 111b for limiting the native substrate 200 at its edge; the bottom surface here and the bottom surface below are used as the supporting surface 111a of the native substrate 200 when transferring the micro light-emitting diode 400, and the cross-sectional area of ​​the limiting profile matches the profile of the native substrate 200.

[0128] In step B220, a transfer cavity 112 is etched on the bottom surface of the accommodating cavity 111 to form a transfer cavity 112, which extends from the bottom surface of the accommodating cavity 111 to the second surface 102.

[0129] In some other embodiments, step B200, the method of forming the hollow cavity 110 on the substrate 200a, includes:

[0130] Step B201: A cavity is formed on the substrate 200a, the cavity extending from the first surface 101 to the second surface 102;

[0131] Step B210: An accommodating cavity 111 is etched on the first surface 101. The accommodating cavity 111 has at least one limiting profile, which includes a bottom surface for supporting the native substrate 200 and a plurality of side surfaces 111b for limiting the native substrate 200 at its edge.

[0132] Both of the above methods form a accommodating cavity 111 with a limiting profile. By simply placing the native substrate 200 into the accommodating cavity 111, the native substrate 200 and the target substrate 300 can be separated by a distance greater than a threshold and limited to the edge of the native substrate 200, so that the micro light-emitting diode 400 on the native substrate 200 can automatically align with the target transfer area 301.

[0133] In some embodiments, in step S210, the method of forming the receiving cavity 111 includes forming at least one of the limiting contours, and the method of forming a single limiting contour includes:

[0134] S211, see also Figure 17 A mask layer 110b with an etching window 110c is formed on the first surface 101, the outline of which matches the outline of the native substrate 200.

[0135] S212. The limiting contour is formed by photolithography of the substrate 200a through the etching window 110c at a preset depth, so that a distance greater than the threshold is formed between the bottom surface of the limiting contour and the second surface 102. Of course, after photolithography is completed, the mask layer 110b needs to be removed.

[0136] In step 212, photolithography is used to form the limiting contour, which helps to achieve precise control of the etching depth and make the final spacing more accurate.

[0137] In some embodiments, if at least two limiting contours are formed in step S210, each limiting contour is formed one by one, and each limiting contour is formed by the method of forming a single limiting contour, that is, steps S211 and S212 are used.

[0138] According to the formation order of each limiting contour, the corresponding etched window 110c of the previous limiting contour and the corresponding etched window 110c of the current limiting contour have a deflection angle, so that the edges of the windows corresponding to each limiting contour are staggered, and the etched windows 110c corresponding to each limiting contour have a common area; the etching depth of each limiting contour is different. During implementation, the etching depth of each contour can gradually decrease or gradually increase. Figure 19 In the process, two limiting contours, K1 and K2, are formed, and the window edges of the etching window 110c corresponding to these two limiting contours are staggered.

[0139] The accommodating cavity 111 formed by this method can limit the position of the native substrate, and at least two limiting contours are formed in the accommodating cavity 111, so that native substrates 200 of different primary colors can be placed in different limiting contours, and at least two primary color micro light-emitting diodes 400 can be transferred using a single mass transfer fixture.

[0140] In some embodiments of the present invention, the method for making the corners of the windows corresponding to each of the limiting contours offset from each other includes:

[0141] The etched windows 110c of each limiting contour share the same geometric center, and the pattern of the current etched window 110c is formed by rotating the pattern of the previous etched window 110c around the geometric center at the deflection angle.

[0142] In some embodiments of the present invention, the spacing ranges from 20µm to 80µm. When multiple limiting contours are formed in the accommodating cavity 111, the etching depth can be controlled to decrease or increase by an equal variable of 10µm or other values, or it can decrease or increase by unequal variables.

[0143] In some embodiments of the present invention, the fixture body 100 is made of a substrate material, which is one of silicon, sapphire, silicon carbide, gallium nitride, gallium arsenide, and indium phosphide.

[0144] In some embodiments of the present invention, when forming the accommodating cavity 111, a laser with a wavelength of 532nm is used for etching, which enables precise control of the spacing.

[0145] For example, in one embodiment of the present invention, a 4-inch silicon wafer with a thickness of 430 μm is provided as a substrate. The silicon wafer has a first surface and a second surface. When forming the accommodating cavity, a first limiting contour, a second limiting contour, a third limiting contour, a fourth limiting contour, a fifth limiting contour, a sixth limiting contour, and a seventh limiting contour are formed sequentially. The etching window corresponding to the current limiting contour has a deflection angle of 20° relative to the etching window corresponding to the previous limiting contour. The etching depth of each limiting contour can be as follows:

[0146] The distance between the bottom surface of the first limiting contour and the second surface is, for example, 80 μm, and the corresponding etching depth is 430-80 μm = 350 μm. The etching depth of the first limiting contour is 350 μm, and the depth of the transfer cavity is 80 μm.

[0147] If the distance between the bottom surface of the second limiting contour and the second surface is, for example, 70 μm, then the etching depth is 430 - 70 = 360 μm.

[0148] The spacing corresponding to the third limiting contour is, for example, 60um, and the corresponding etching depth is 430-60=370um;

[0149] The spacing corresponding to the fourth limiting contour is, for example, 50um, and the corresponding etching depth is 430-50=380um;

[0150] The spacing corresponding to the fifth limiting contour is, for example, 40um, and the corresponding etching depth is 430-40=390um;

[0151] The spacing corresponding to the sixth limiting contour is, for example, 30um, and the corresponding etching depth is 430-30=400um;

[0152] The spacing corresponding to the seventh limiting contour is, for example, 20um, and the corresponding etching depth is 430-20=410um.

[0153] After completing the above etching process step by step, taking the initial 80µm gap and the final 20µm gap as examples, the state diagrams of the mass transfer fixture applied to the micro-LED transfer are respectively shown below. Figure 10 and Figure 9 .

[0154] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A mass transfer fixture, characterized in that, include: The fixture body has a first surface and a second surface that are opposite to each other; and A hollow chamber is disposed on the fixture body and extends from the first surface to the second surface; The hollow cavity contains a bearing surface, and the distance between the bearing surface and the second surface is greater than a threshold value; the distance between the bearing surface and the second surface ranges from 20 μm to 80 μm. The hollow cavity includes a receiving cavity and a transfer cavity arranged sequentially along the direction from the first surface to the second surface. The receiving cavity has at least one limiting profile, each limiting profile including: At least one of the aforementioned bearing surfaces is used to support a native substrate on which micro-light-emitting diodes are grown, wherein the native substrate is a polygonal substrate; and Multiple sides are connected to the bearing surface, and each side is used to limit the edge of the original substrate.

2. The mass transfer fixture according to claim 1, characterized in that: The accommodating cavity has only one limiting contour, the hollow cavity is a stepped cavity, and the bearing surface is the stepped surface of the stepped cavity.

3. The mass transfer fixture according to claim 1, characterized in that: The accommodating cavity has at least two limiting contours, and in any one of the limiting contours, two adjacent sides intersect to form a limiting angle; The bearing surfaces of each of the limiting contours are distributed at different depths of the accommodating cavity, and the limiting angles of each of the limiting contours are staggered on the cavity wall of the accommodating cavity.

4. The mass transfer fixture according to claim 3, characterized in that: Each of the limiting contours has a geometric center line located at the same position, and each of the limiting contours has a deflection angle centered on the geometric center line.

5. The mass transfer fixture according to claim 3, characterized in that: In each of the limiting contours, at least two limiting contours have parallel geometric center lines that do not overlap, any two limiting contours have a deflection angle, and any two limiting contours share a common space.

6. The mass transfer fixture according to claim 1, characterized in that: The fixture body is made of a substrate material, which is one of silicon, sapphire, silicon carbide, gallium nitride, gallium arsenide, and indium phosphide.

7. A mass transfer method, characterized in that, include: Provide a mass transfer fixture as described in any one of claims 1-6; A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate; Provide a native substrate on which micro light-emitting diodes are grown; The mass transfer fixture is placed on the target substrate, so that the second surface contacts the target substrate, and the hollow cavity is aligned with a target transfer area; The native substrate is transferred to the carrier surface, such that the side of the native substrate on which the micro-light-emitting diodes are grown faces the same target transfer area; The micro-LEDs to be transferred are removed from the native substrate by laser, causing the micro-LEDs to fall onto the corresponding electrode pads in the target transfer area.

8. A mass transfer method, characterized in that, include: Provide a mass transfer fixture as described in any one of claims 1-6; A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate; Provide a native substrate on which micro light-emitting diodes are grown; The mass transfer fixture is placed on the target substrate, so that the second surface contacts the target substrate, and the hollow cavity is aligned with a target transfer area; The native substrate is transferred into the limiting contour so that the native substrate is placed on a bearing surface, and the corresponding plurality of the sides are limited at the edge of the native substrate, and the side on the native substrate on which the micro light-emitting diodes are grown faces the same target transfer area. The micro-LEDs to be transferred are removed from the native substrate by laser, causing the micro-LEDs to fall onto the corresponding electrode pads in the target transfer area.

9. A mass transfer method, characterized in that: Provide a mass transfer fixture as described in any one of claims 3-5; A target substrate is provided, wherein at least one target transfer region is disposed on the target substrate; Provide at least two native substrates on which micro-light-emitting diodes are grown, wherein the native substrates are monochrome native substrates and the micro-light-emitting diodes grown on each native substrate have different primary colors; The mass transfer fixture is placed on the target substrate, so that the second surface contacts the target substrate, and the hollow cavity is aligned with a target transfer area; Each of the original substrates is placed into different limiting contours so that each original substrate is placed on a different bearing surface, and the corresponding multiple sides are limited at the edge of the original substrate; and when any original substrate is placed into any limiting contour, the side of the original substrate on which the micro light-emitting diode is grown faces the same target transfer area. The micro light-emitting diode to be transferred on the original substrate is peeled off by laser so that the micro light-emitting diode falls onto the corresponding electrode pad of the target transfer area.

10. The mass transfer method according to any one of claims 7-9, characterized in that: The method for obtaining the native substrate is as follows: a native wafer is provided, micro light-emitting diodes are grown on the native wafer, and the native wafer is divided to form multiple native substrates.

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