A Micro-LED chip carrier substrate and a manufacturing method thereof

Abstract

The present invention discloses a Micro-LED chip carrier substrate and a manufacturing method thereof. The Micro-LED chip carrier substrate includes a substrate, a connection layer connected to the front surface of the substrate on the back surface, and a plurality of microstructures disposed on the front surface of the connection layer. The microstructures have elasticity, and each microstructure is arranged in an array on the front surface of the connection layer. The Micro-LED chip carrier substrate of the present invention is used for temporarily bonding with a Micro-LED chip. When the Micro-LED chip is peeled off from a sapphire substrate by using a laser lift-off technology (LLO), the Micro-LED chip carrier substrate can effectively prevent the Micro-LED chip from cracking and / or shifting in position.

Description

Technical Field

[0001] The present invention relates to the field of LED displays, and particularly to a Micro-LED chip carrier substrate and a manufacturing method thereof. Background Art

[0002] With the rapid development of the information industry, the application of electronic products is becoming more and more extensive. For electronic products such as mobile phones, tablet computers, notebooks, and televisions, display technology is very crucial. Currently, the most common display technology is light-emitting diodes. Micro-LED chips are a new generation of display technology. Micro-LED chips have the advantages of low power consumption, high brightness, high efficiency, high reliability, short response time, long life, ultra-high resolution, and color saturation. There is data showing that compared with LCD and OLED, the power consumption of Micro-LED chips is about 10% of that of LCD and 50% of that of OLED. It can be seen that Micro-LED chips have very obvious advantages and have great application prospects in the future.

[0003] In the prior art, in the production process of a Micro-LED display panel based on Micro-LED chips, tens of millions of Micro-LED chips need to be first peeled off from a sapphire substrate, and then the Micro-LED chips are assembled onto a driving backplane. When the Micro-LED chips are peeled off from the sapphire substrate, the Micro-LED chips need to be temporarily bonded to a carrier substrate for temporary use with a temporary bonding material first, and then a laser lift-off technology (LLO) is used to peel the Micro-LED chips from the sapphire substrate, so that the Micro-LED chips are transferred onto the carrier substrate. The temperature during the epitaxial growth of Micro-LED chips is as high as 1000 degrees Celsius, and the thermal expansion coefficients of the gallium nitride epitaxial layer of Micro-LED chips and the sapphire substrate are quite different, resulting in unevenly distributed internal stresses between the gallium nitride epitaxial layer and the sapphire substrate. When the laser lift-off technology (LLO) is used to peel the Micro-LED chips from the sapphire substrate, the internal stresses released by each Micro-LED chip temporarily bonded to the carrier substrate will have differences in magnitude and direction, thereby causing the Micro-LED chips to crack and / or shift in position. Summary of the Invention

[0004] The object of the present invention is to provide a Micro-LED chip carrier substrate and a manufacturing method thereof. The Micro-LED chip carrier substrate is used for temporarily bonding with a Micro-LED chip. When the Micro-LED chip is peeled off from a sapphire substrate by using a laser lift-off technology (LLO), the Micro-LED chip carrier substrate can effectively prevent the Micro-LED chip from cracking and / or shifting in position.

[0005] To achieve the above object, the solution of the present invention is as follows:

[0006] A Micro-LED chip carrier substrate includes a substrate, a connection layer whose back surface is connected to the front surface of the substrate, and a plurality of microstructures arranged on the front surface of the connection layer; the microstructures are elastic, and each microstructure is distributed in an array on the front surface of the connection layer and protrudes from the front surface of the connection layer.

[0007] The material of the microstructures is a polymer elastomer.

[0008] The microstructures are hemispherical or columnar.

[0009] There are gaps between the microstructures.

[0010] The microstructure includes a column body with one end connected to the front surface of the connection layer and a cover body connected to the other end of the column body. The diameter of the cover body is larger than that of the column body, and the cross-section of the microstructure is T-shaped.

[0011] There are gaps between the microstructures, and the diameter of the column body of the microstructure is smaller than the distance between the microstructures.

[0012] A manufacturing method of a Micro-LED chip carrier substrate includes the following steps in sequence:

[0013] Step 1: Fabricate a forming mold, and a plurality of grooves are arranged on the surface of the forming mold, and each groove is distributed in an array;

[0014] Step 2: Coat a liquid forming layer on the surface of the forming mold. The liquid forming layer fills the grooves on the surface of the forming mold, and the forming layer can be cured; then place a substrate on the forming layer so that the front surface of the substrate contacts the forming layer, and use a support member to support the substrate so that a space is formed between the substrate and the forming mold, thereby obtaining a semi-finished carrier substrate;

[0015] Step 3: Cure the liquid forming layer in the semi-finished carrier substrate. The cured forming layer forms a connection layer whose back surface is connected to the front surface of the substrate and a plurality of microstructures arranged on the front surface of the connection layer, wherein the microstructures are fitted in the grooves;

[0016] Step 4: Remove the forming mold and the support member to obtain the Micro-LED chip carrier substrate.

[0017] The method for manufacturing the forming mold is specifically as follows: Etch a mold plate so that the grooves distributed in an array are formed on the front surface of the mold plate, thereby obtaining the forming mold.

[0018] In Step 1, after the forming mold is manufactured, clean the forming mold.

[0019] The grooves are hemispherical, and the diameter of the grooves is 100 nanometers to 5 micrometers.

[0020] The method for manufacturing the forming mold specifically includes the following steps in sequence:

[0021] Step R1: Spin-coat a liquid photoresist layer on the front surface of a mold plate, and bake the liquid photoresist layer to preliminarily cure the photoresist layer. The material of the photoresist layer is a positive photoresist, and the mold plate has light transmittance.

[0022] Step R2: Parallelly arrange a first mask plate having a plurality of first light-transmitting structures distributed in an array on the upper side of the mold plate, and irradiate the first mask plate with a first ultraviolet light source to expose the photoresist layer; and parallelly arrange a second mask plate having a plurality of second light-transmitting structures distributed in an array on the lower side of the mold plate, and irradiate the second mask plate with a second ultraviolet light source to expose the photoresist layer; wherein the diameter of the second light-transmitting structures of the second mask plate is larger than the diameter of the first light-transmitting structures of the first mask plate, and the areas of the photoresist layer exposed by the first ultraviolet light source and the areas of the photoresist layer exposed by the second ultraviolet light source correspond one by one.

[0023] Step R3: Develop the exposed photoresist layer to remove the exposed part of the photoresist layer, so that the grooves distributed in an array are formed on the front surface of the photoresist layer. The grooves include a cover hole and a column hole that are connected to each other, and the diameter of the cover hole is larger than the diameter of the column hole; then bake the photoresist layer to completely cure the photoresist layer, and further obtain the forming mold.

[0024] In Step 4 of the manufacturing method of the Micro-LED chip carrier substrate, when removing the forming mold, use a photoresist stripping solvent to remove the photoresist layer of the forming mold, so that the forming mold is separated from the substrate to remove the forming mold.

[0025] The material of the forming layer is polydimethylsiloxane.

[0026] Another manufacturing method of the Micro-LED chip carrier substrate includes the following steps in sequence:

[0027] Step 1: Fabricate a forming mold and fabricate a preliminary carrier substrate blank; wherein the surface of the forming mold is provided with a plurality of grooves, each groove is arranged in an array, and the grooves are columnar; and the preliminary carrier substrate blank includes a substrate and a curable forming layer attached to the front surface of the substrate, and the surface layer of the forming layer is cured;

[0028] Step 2: Press the preliminary carrier substrate blank and the forming mold together so that the forming layer of the preliminary carrier substrate blank deforms and fills the grooves on the surface of the forming mold;

[0029] Step 3: Preliminarily cure the forming layer of the preliminary carrier substrate blank so that the forming layer of the preliminary carrier substrate blank is preliminarily cured to form a connection layer whose back surface is connected to the front surface of the substrate and a plurality of micro-structure embryos arranged on the front surface of the connection layer, wherein the micro-structure embryos are fitted in the grooves;

[0030] Step 4: First remove the forming mold; then use a pressing plate to extrude the ends of the micro-structure embryos on the preliminary carrier substrate blank so that each micro-structure embryo deforms to form a micro-structure; finally, finally cure the connection layer and each micro-structure on the preliminary carrier substrate blank, and remove the pressing plate after the connection layer and each micro-structure are finally cured, thereby obtaining a Micro-LED chip carrier substrate; wherein the micro-structure includes a column body whose one end is connected to the front surface of the connection layer and a cover body connected to the other end of the column body, the diameter of the cover body is larger than the diameter of the column body, and the cross-section of the micro-structure is T-shaped.

[0031] The method for fabricating the forming mold includes the following steps in sequence:

[0032] Step S1: Etch an inverted template so that convex columns arranged in an array are formed on the front surface of the etched inverted template, and perform plasma cleaning on the etched inverted template;

[0033] Step S2: Coat a liquid mold layer on the front surface of the inverted template, the mold layer is curable, and the liquid mold layer covers the convex columns on the front surface of the inverted template; then place a mold plate on the liquid mold layer so that the mold plate contacts the mold layer, and use a support member to support the mold plate so that a gap is formed between the mold plate and the inverted template, thereby obtaining a semi-finished forming mold;

[0034] Step S3: Cure the mold layer in the semi-finished forming mold, the cured mold layer is connected to the mold plate, and the cured mold layer has a plurality of grooves for sleeving the convex columns;

[0035] Step S4: Remove the inverted template and the support member to obtain the forming mold.

[0036] The method for fabricating the preliminary carrier substrate blank is: spin-coat a curable forming layer on the front surface of a substrate, and slightly cure the forming layer to obtain the preliminary carrier substrate blank.

[0037] After adopting the above solution, when the Micro-LED chip carrier substrate of the present invention is temporarily bonded to the Micro-LED chip, the Micro-LED chip is adhered to the microstructure of the Micro-LED chip carrier substrate by van der Waals force. When the Micro-LED chip carrier substrate A is temporarily bonded to the Micro-LED chip and then the laser lift-off technology is used to separate the Micro-LED chip from the sapphire substrate, the microstructure can be deformed to absorb the internal stress released by the gallium nitride epitaxial layer of the Micro-LED chip, thereby avoiding the problems of cracking and / or displacement of the Micro-LED chip caused by impact. Description of the Drawings

[0038] Figure 1 Schematic diagram of the manufacturing method of the Micro-LED chip carrier substrate according to Embodiment 1 of the present invention;

[0039] Figure 2 Schematic diagram of the manufacturing method of the Micro-LED chip carrier substrate according to Embodiment 2 of the present invention;

[0040] Figure 3 Schematic diagram of the method for manufacturing the molding die according to Embodiment 2 of the present invention;

[0041] Figure 4 Schematic diagram of the manufacturing method of the Micro-LED chip carrier substrate according to Embodiment 3 of the present invention;

[0042] Label Description:

[0043] Micro-LED chip carrier substrate A, semi-finished carrier substrate A', initial embryo of carrier substrate A''

[0044] Substrate 1

[0045] Molding layer 2, connecting layer 21, microstructure 22, initial embryo of microstructure 22', column 221, cover 222

[0046] Molding die B, semi-finished molding die B', groove B1, cover hole B11, column hole B12, die plate B2, mold layer B3, photolithography layer B4

[0047] Supporting member C

[0048] Pressing plate D

[0049] Inverted template E, convex column E1

[0050] First mask plate F, first light-transmitting structure F1

[0051] Second mask plate G, second light-transmitting structure G1 Detailed Description of the Invention

[0052] As Figures 1 to 4 shown, the present invention discloses a Micro-LED chip carrier substrate A, which includes a substrate 1, a connection layer 21 whose back surface is connected to the front surface of the substrate 1, and a plurality of microstructures 22 disposed on the front surface of the connection layer 21; wherein the microstructures 22 are elastic, and the microstructures 22 are arranged in an array on the front surface of the connection layer 21 and protrude from the front surface of the connection layer 21, and the microstructures 22 can be integrally formed with the connection layer 21; the materials of the microstructures 22 and the connection layer 21 can be polymer elastomers, such as polydimethylsiloxane or polyurethane acrylate resin.

[0053] When the Micro-LED chip carrier substrate A of the present invention is temporarily bonded to the Micro-LED chip, the Micro-LED chip is bonded to the microstructures 22 of the Micro-LED chip carrier substrate A by van der Waals force. When the Micro-LED chip carrier substrate A is temporarily bonded to the Micro-LED chip and then the Micro-LED chip is peeled off from the sapphire substrate by using a laser lift-off technique, the microstructures 22 can be deformed to absorb the internal stress released by the gallium nitride epitaxial layer of the Micro-LED chip, thereby avoiding the problems of cracking and / or displacement of the Micro-LED chip due to impact.

[0054] In order to further explain the technical solution of the present invention, the present invention will be elaborated in detail through several embodiments below.

[0055] Embodiment 1:

[0056] In the first embodiment of the present invention, there are gaps between the microstructures 22 of the Micro-LED chip carrier substrate A to provide deformation space for the microstructures 22, and the distances between the microstructures 22 can be set to be equal, so that the microstructures 22 are independent of each other to reduce the interference between the microstructures 22.

[0057] Cooperating with Figure 1 shown, in the first embodiment of the present invention, the manufacturing method of the Micro-LED chip carrier substrate A includes the following steps in sequence:

[0058] Step 1: Fabricate a molding die B, the surface of which is provided with a plurality of grooves B1, and the grooves B1 are arranged in an array, and the grooves B1 are used for forming the microstructures;

[0059] Step 2: Coat a liquid forming layer 2 on the surface of the forming mold B. The liquid forming layer 2 fills the grooves B1 on the surface of the forming mold B, and the forming layer 2 can be cured. Then, place a substrate 1 on the liquid forming layer 2 so that the front surface of the substrate 1 contacts the forming layer 2, and use a support C to support the substrate 1 to form a gap between the substrate 1 and the forming mold B, thereby obtaining a carrier substrate semi-finished product A'.

[0060] Step 3: Cure the liquid forming layer 2 in the carrier substrate semi-finished product A'. After curing, the forming layer forms a connection layer 21 with its back surface connected to the front surface of the substrate 1 and several microstructures 22 arranged on the front surface of the connection layer 21. The microstructures 22 are fitted into the grooves B1.

[0061] Step 4: Remove the forming mold B and the support C to obtain the Micro-LED chip carrier substrate A.

[0062] In the first embodiment of the present invention, the method for manufacturing the forming mold B is specifically as follows: Etch a mold plate B2 so that the front surface of the mold plate B2 forms the grooves B1 distributed in an array, thereby obtaining the forming mold B. The mold plate B2 can be a wafer, a sapphire sheet, or a glass sheet that can be precisely etched. In step 1, after the forming mold B is manufactured, clean the forming mold B to remove dirt on the forming mold. The cleaning method can be plasma cleaning. The plasma cleaning method can specifically be to use oxygen plasma to clean the surface of the forming mold B under a gas pressure environment of 50 - 80 Pa, and the cleaning time is 30 - 60 seconds.

[0063] In the first embodiment of the present invention, the groove B1 is hemispherical so that the microstructure 22 is hemispherical, and the diameter of the groove B1 is 100 nanometers to 5 micrometers so that the diameter of the hemispherical microstructure is 100 nanometers to 5 micrometers. In the first embodiment of the present invention, the groove B1 can also be cylindrical so that the microstructure 22 is cylindrical, and the diameter of the groove B1 is 1 micrometer to 5 micrometers so that the diameter of the cylindrical microstructure 22 is 1 micrometer to 5 micrometers. The depth of the groove B1 is 0.8 - 1.5 times the diameter of the groove B1 so that the height of the microstructure 22 is 0.8 - 1.5 times the diameter of the microstructure 22. The manufacturing method of the Micro-LED chip carrier substrate A in the first embodiment of the present invention can achieve high-precision processing of the groove B1, thereby enabling the manufacture of microstructures with small sizes.

[0064] In step 2 of the first embodiment of the present invention, before coating a liquid forming layer 2 on the surface of the forming mold B, dimethyl silicone oil can be sprayed on the surface of the forming mold B, and the spraying thickness is not greater than 10 micrometers. The dimethyl silicone oil can make the connection layer 21 and the microstructures 22 easier to separate from the forming mold B.

[0065] In the first embodiment of the present invention, the support member C can be clamped between the substrate 1 and the molding die B so that a gap is formed between the substrate 1 and the molding die B. The support member C can be glass, a quartz sheet, or a silicon wafer. The thickness of the support member C (i.e., the gap between the substrate and the molding die) determines the thickness of the connection layer 21.

[0066] In the first embodiment of the present invention, the material of the molding layer 2 is polydimethylsiloxane. In this way, the materials of both the connection layer 21 and the microstructure 22 are polydimethylsiloxane. Polydimethylsiloxane has elasticity and viscosity after curing. The viscosity can make the microstructure 22 more reliably combined with the Micro-LED chip. In the first embodiment of the present invention, the curing of the liquid molding layer 2 specifically includes: allowing the carrier substrate semi-finished product A' to stand in a vacuum environment for 1 to 2 hours, and then keeping it warm at 60 to 70 degrees Celsius for 24 to 36 hours.

[0067] Embodiment Two:

[0068] Cooperate Figure 2 As shown, in the second embodiment of the present invention, the microstructure 22 includes a column 221 whose one end is connected to the front surface of the connection layer 21 and a cover 222 connected to the other end of the column 221. The diameter of the cover 222 is larger than the diameter of the column 221, and the cross-section of the microstructure 22 is in a T shape. The purpose of setting the cover 222 is to increase the bonding area between the microstructure 22 and the Micro-LED chip, making the combination of the microstructure 22 and the Micro-LED chip more stable.

[0069] In the second embodiment of the present invention, there are gaps between the microstructures 22 to provide deformation space for the microstructures 22 and avoid interference between the microstructures 22. The distances between the microstructures 22 can be set to be equal. The diameter of the column 221 of the microstructure 22 can be smaller than the distances between the microstructures 22, so that the deformation space of the column 221 is large.

[0070] Cooperate Figure 2 and Figure 3 As shown, in the second embodiment of the present invention, the manufacturing method of the Micro-LED chip carrier substrate A includes the following steps in sequence:

[0071] Step One: Fabricate the molding die B and fabricate the carrier substrate embryo A''. The surface of the molding die B is provided with a plurality of grooves B1, and the grooves B1 are arranged in an array. The grooves B1 are columnar. The carrier substrate embryo A'' includes a substrate 1 and a layer of curable molding layer 2 attached to the front surface of the substrate 1. The surface layer of the molding layer 2 is cured, and the cured surface layer of the molding layer 2 has the ability of plastic deformation.

[0072] Step 2: Press-fit the carrier substrate embryo A'' and the molding die B so that the molding layer 2 of the carrier substrate embryo A'' deforms and fills the grooves B1 on the surface of the molding die B. The environment for the press-fitting is a vacuum environment, and the pressure for the press-fitting is 10 - 15 KPa;

[0073] Step 3: Preliminarily cure the molding layer 2 of the carrier substrate embryo A'' so that the molding layer 2 of the carrier substrate embryo A'' is preliminarily cured to form a connection layer 21 with its back surface connected to the front surface of the substrate 1 and several micro-structure embryos 22' arranged on the front surface of the connection layer 21, wherein the micro-structure embryos 22' are fitted into the grooves B1;

[0074] Step 4: First, remove the molding die B; then use a pressing plate D to extrude the ends of the micro-structure embryos 22' on the carrier substrate embryo A'' so that each micro-structure embryo 22' deforms to form a micro-structure 22. The pressing plate D is a flat plate, and the material of the pressing plate D can be a material with light-transmitting properties such as quartz, glass, or silicon wafer, etc. The pressure for the extrusion can be 15 - 20 KPa; finally, perform final curing on the connection layer 21 and each micro-structure 22 on the carrier substrate embryo A'', and remove the pressing plate D after the connection layer 21 and each micro-structure 22 are finally cured, thereby obtaining the Micro-LED chip carrier substrate A.

[0075] Cooperate Figure 3 As shown, in the second embodiment of the present invention, the method for manufacturing the molding die B includes the following sequential steps:

[0076] Step S1: Etch an inverted template E so that convex columns E1 arranged in an array are formed on the front surface of the etched inverted template E, and perform plasma cleaning on the etched inverted template E; the inverted template E can be a silicon wafer, a sapphire sheet, or glass, etc., which are sheet bodies that can be precisely etched. The specific method of plasma cleaning can be to use oxygen plasma to clean the surface of the inverted template E in an air pressure environment of 50 - 80 Pa, and the cleaning time is 30 - 50 seconds;

[0077] Step S2: Coat a liquid mold layer B3 on the front surface of the inverted template E. The mold layer B3 can be cured, and the liquid mold layer B3 covers the convex columns E1 on the front surface of the inverted template E; then place a mold plate B2 on the liquid mold layer B3 so that the mold plate B2 contacts the mold layer B3, and use a support member C to support the mold plate B2 so that a gap is formed between the mold plate B2 and the inverted template E, thereby obtaining a molding die semi-finished product B';

[0078] Step S3: Cure the mold layer B3 in the molding die semi-finished product B'. The cured mold layer B3 is connected to the mold plate B2, and the cured mold layer B3 has several grooves B1 sleeving the convex columns E1;

[0079] Step S4: Remove the reverse mold E and the support member C to obtain the formed mold B; the formed mold B includes a mold plate B2 and a cured mold layer B3 fitted on the mold plate B2.

[0080] In the step S2 of the second embodiment of the present invention, before applying a layer of liquid mold layer B3 on the front surface of the reverse mold E, dimethyl silicone oil can be sprayed on the front surface of the cleaned reverse mold E first, and the spraying thickness is not greater than 10 microns; the dimethyl silicone oil can make the mold layer B3 easier to separate from the reverse mold E.

[0081] In the second embodiment of the present invention, the support member C can be clamped between the mold plate B2 and the reverse mold E to form a gap between the mold plate B2 and the reverse mold E. The support member C can be glass, a quartz sheet, or a silicon wafer. The thickness of the support member C (i.e., the gap between the mold plate and the reverse mold) determines the thickness of the mold layer B3.

[0082] In the second embodiment of the present invention, the material of the mold layer B3 is polydimethylsiloxane. Specifically, curing the liquid mold layer B3 is as follows: Let the semi-finished formed mold B' stand in a vacuum environment for 1 hour, and then keep it warm at 60 °C for 24 hours.

[0083] In the second embodiment of the present invention, the method for manufacturing the carrier substrate blank A'' is as follows: Spin-coat a curable forming layer 2 on the front surface of a substrate 1, and slightly cure the forming layer 2 so that the surface layer of the forming layer 2 is cured to obtain the carrier substrate blank A''. The material of the forming layer 2 is polyurethane acrylate resin; slightly curing the forming layer 2 is as follows: Use an ultraviolet light source to irradiate the forming layer 2 from the back side of the substrate 1. The irradiation power density of the ultraviolet light source is 5 - 10 mW / cm 2 , and the irradiation time is 40 - 50 seconds; preliminarily curing the forming layer 2 is as follows: Use an ultraviolet light source to perform two-way irradiation on the forming layer 2 from the front side and the back side of the substrate 1. The irradiation power density of the ultraviolet light source is 50 - 60 mW / cm 2 , and the irradiation time is 25 - 30 seconds; finally curing the connecting layer 21 and each microstructure 22 is as follows: Use an ultraviolet light source to irradiate the connecting layer 21 and each microstructure 22 through the pressing plate D. The irradiation power density of the ultraviolet light source is 500 - 520 mW / cm 2 , and the irradiation time is 50 - 60 seconds.

[0084] In the step two of the second embodiment of the present invention, before pressing the carrier substrate blank A'' and the formed mold B together, dimethyl silicone oil can be sprayed on the surface of the formed mold B first, and the spraying thickness is not greater than 10 microns. The dimethyl silicone oil can make the connecting layer 21 and the microstructure blank 22' easier to separate from the formed mold B.

[0085] Embodiment 3:

[0086] Cooperate with Figure 4 As shown, in Embodiment 3 of the present invention, the microstructure 22 includes a column 221 with one end connected to the front surface of the connection layer 21 and a cover 222 connected to the other end of the column 221. The diameter of the cover 222 is larger than that of the column 221, and the cross-section of the microstructure 22 is T-shaped; the purpose of setting the cover 222 is to increase the bonding area between the microstructure 22 and the Micro-LED chip, making the bonding between the microstructure 22 and the Micro-LED chip more stable.

[0087] In Embodiment 3 of the present invention, there are gaps between the microstructures 22 to provide deformation space for the microstructures 22 and avoid interference between the microstructures 22. The distances between the microstructures 22 can be set to be equal; the diameter of the column 221 of the microstructure 22 can be smaller than the distances between the microstructures 22, so that the deformation space of the column 221 is large.

[0088] Cooperate with Figure 4 As shown, in Embodiment 3 of the present invention, the manufacturing method of the Micro-LED chip carrier substrate A includes the following steps in sequence:

[0089] Step 1: Fabricate a forming mold B. The surface of the forming mold B is provided with a plurality of grooves B1, and the grooves B1 are arranged in an array. The grooves B1 are used to form the microstructures 22. The grooves B1 include a cover hole B11 and a column hole B12 that are connected to each other. The diameter of the cover hole B11 is larger than that of the column hole B12. The cover hole B11 is used to form the cover 222 of the microstructure 22, and the column hole B12 is used to form the column 221 of the microstructure 22;

[0090] Step 2: Coat a liquid forming layer 2 on the surface of the forming mold B. The liquid forming layer 2 fills the grooves B1 on the surface of the forming mold B, and the forming layer 2 can be cured; then a substrate 1 is placed on the liquid forming layer 2 so that the front surface of the substrate 1 contacts the forming layer 2, and a support member C is used to support the substrate 1 so that there is a gap between the substrate 1 and the forming mold B, thereby obtaining a carrier substrate semi-finished product A';

[0091] Step 3: Cure the liquid forming layer 2 in the carrier substrate semi-finished product A'. After curing, the forming layer 2 forms a connection layer 21 with the back surface connected to the front surface of the substrate 1 and a plurality of microstructures 22 arranged on the front surface of the connection layer 21, wherein the microstructures 22 are fitted in the grooves B1;

[0092] Step 4: Remove the forming mold B and the support member C, thereby obtaining the Micro-LED chip carrier substrate A.

[0093] In the third embodiment of the present invention, the method for manufacturing the molding die B includes the following steps in sequence:

[0094] Step R1: Spin-coat a layer of liquid photoresist layer B4 on the front surface of a mold plate B2, and bake the liquid photoresist layer B4 to preliminarily cure the photoresist layer B4; wherein the mold plate B2 can be a quartz wafer, and the mold plate B2 has light transmissivity so that ultraviolet light can pass through the mold plate B2; the material of the photoresist layer B4 is a positive photoresist, and the part of the positive photoresist exposed to ultraviolet light can be dissolved by the developer; the way of baking the liquid photoresist layer B4 is: first bake at 80 - 85 °C for 5 - 10 minutes, and then bake at 90 - 95 °C for 10 - 15 minutes;

[0095] Step R2: Parallelly arrange a first mask plate F with a plurality of first light-transmitting structures F1 distributed in an array on the upper side of the mold plate B2, and use a first ultraviolet light source to irradiate the first mask plate F to expose the photoresist layer B4; and parallelly arrange a second mask plate G with a plurality of second light-transmitting structures G1 distributed in an array on the lower side of the mold plate B2, and use a first ultraviolet light source to irradiate the second mask plate G to expose the photoresist layer B4; wherein each first light-transmitting structure F1 of the first mask plate F and each second light-transmitting structure G1 of the second mask plate G can transmit ultraviolet light, so that the ultraviolet light of the first ultraviolet light source can pass through the first light-transmitting structures F1 of the first mask plate F to expose the photoresist layer B4, and the ultraviolet light of the second ultraviolet light source can pass through the second light-transmitting structures G1 of the second mask plate G to expose the photoresist layer B4; in step R2, by controlling the positions of the first mask plate F and the second mask plate G, the areas of the photoresist layer B4 exposed by the first ultraviolet light source and the areas of the photoresist layer B4 exposed by the second ultraviolet light source are in one-to-one correspondence, and the diameter of the second light-transmitting structure G1 is larger than the diameter of the first light-transmitting structure F1. The diameter of the second light-transmitting structure G1 is used to control the diameter of the cover hole B11, and the diameter of the first light-transmitting structure F1 is used to control the diameter of the column hole B12;

[0096] Step R3: Develop the exposed photoresist layer B4 to remove the exposed part of the photoresist layer B4, so that the grooves B1 arranged in an array are formed on the front surface of the photoresist layer B4; then bake the photoresist layer B4 to completely cure the photoresist layer B4, and thus obtain the molding die B. The baking of the photoresist layer B4 is: bake at 100 °C for 10 minutes.

[0097] In the method of manufacturing the forming die B in the third embodiment of the present invention, high-precision machining of the groove B1 can be achieved, so that microstructures with small dimensions can be manufactured. In the third embodiment of the present invention, since the forming die B has a photolithography layer B4, when removing the forming die B in step four, a photoresist stripping solvent can be used to remove the photolithography layer B4 of the forming die B, so that the forming die B is separated from the substrate 1 to remove the forming die B, and it is very convenient to remove the forming die B in this way.

[0098] In the third embodiment of the present invention, the support member C can be clamped between the substrate 1 and the forming die B to form a gap between the substrate 1 and the forming die B. The support member C can be glass, a quartz wafer, or a silicon wafer. The thickness of the support member C (i.e., the gap between the substrate and the forming die) determines the thickness of the connection layer 21.

[0099] In the third embodiment of the present invention, the material of the forming layer 2 is polydimethylsiloxane. In this way, the materials of both the connection layer 21 and the microstructure 22 are polydimethylsiloxane. After polydimethylsiloxane is cured, it has elasticity and viscosity, and the viscosity can make the microstructure 22 more reliably combined with the Micro-LED chip A. In the third embodiment of the present invention, curing the liquid forming layer 2 specifically includes: allowing the semi-finished carrier substrate A' to stand in a vacuum environment for 1 hour, and then keeping it at 60 °C for 24 hours.

[0100] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by those of ordinary skill in the art shall be regarded as not departing from the patent scope of the present invention.

Claims

1. A manufacturing method of a Micro-LED chip carrier substrate, characterized in that: Including the following steps in sequence: Step 1: Fabricate a forming mold, on the surface of which there are a plurality of grooves, and the grooves are arranged in an array; Step 2: Coating a liquid forming layer on the surface of the forming mold, the liquid forming layer fills the grooves on the surface of the forming mold, and the forming layer can be cured; then placing a substrate on the forming layer so that the front surface of the substrate contacts the forming layer, and using a support member to support the substrate to form a gap between the substrate and the forming mold, thereby obtaining a semi-finished substrate carrier; Step 3: Curing the liquid forming layer in the semi-finished substrate carrier, and the cured forming layer forms a connection layer connecting the back surface and the front surface of the substrate and a plurality of microstructures arranged on the front surface of the connection layer, wherein the microstructures are fitted into the grooves; Step 4: Removing the forming mold and the support member, thereby obtaining a Micro-LED chip carrier substrate; The method for fabricating the forming mold specifically includes the following steps in sequence: Step R1: Spin-coating a liquid photoresist layer on the front surface of a mold plate, and baking the liquid photoresist layer to preliminarily cure the photoresist layer, the material of the photoresist layer is a positive photoresist, and the mold plate has light transmissivity; Step R2: Parallelly arranging a first mask plate with a plurality of first light-transmitting structures arranged in an array on the upper side of the mold plate, and irradiating the first mask plate with a first ultraviolet light source to expose the photoresist layer; and parallelly arranging a second mask plate with a plurality of second light-transmitting structures arranged in an array on the lower side of the mold plate, and irradiating the second mask plate with a second ultraviolet light source to expose the photoresist layer; wherein the diameter of the second light-transmitting structure of the second mask plate is larger than the diameter of the first light-transmitting structure of the first mask plate, and the areas of the photoresist layer exposed by the first ultraviolet light source and the areas of the photoresist layer exposed by the second ultraviolet light source correspond to each other one by one; Step R3: Developing the exposed photoresist layer to remove the exposed part of the photoresist layer, so that the front surface of the photoresist layer forms the grooves arranged in an array, the grooves include a cover hole and a column hole connected to each other, and the diameter of the cover hole is larger than the diameter of the column hole; then baking the photoresist layer to completely cure the photoresist layer, thereby obtaining the forming mold.

2. The manufacturing method according to claim 1, characterized in that: In Step 4, when removing the forming mold, using a photoresist stripping solvent to remove the photoresist layer of the forming mold, so that the forming mold is separated from the substrate to remove the forming mold.

3. The manufacturing method according to claim 1, characterized in that: The material of the forming layer is polydimethylsiloxane.

4. A manufacturing method of a Micro-LED chip carrier substrate, characterized in that: Including the following steps in sequence: Step 1: Fabricate a forming mold and fabricate a preliminary embryo of a substrate carrier; wherein there are a plurality of grooves on the surface of the forming mold, the grooves are arranged in an array, and the grooves are columnar; and the preliminary embryo of the substrate carrier includes a substrate and a layer of curable forming layer attached to the front surface of the substrate, and the surface layer of the forming layer is cured; Step 2: Pressing the preliminary embryo of the substrate carrier and the forming mold together, so that the forming layer of the preliminary embryo of the substrate carrier deforms and fills the grooves on the surface of the forming mold; Step 3: Initially cure the forming layer of the carrier substrate embryo, so that the forming layer of the carrier substrate embryo is initially cured to form a connection layer connecting the back surface to the front surface of the substrate and a plurality of micro-structure embryos disposed on the front surface of the connection layer, wherein the micro-structure embryos are fitted into the grooves; Step 4: First, remove the forming mold; then use a pressing plate to extrude the ends of the respective micro-structure embryos on the carrier substrate embryo, so that the respective micro-structure embryos are deformed to form micro-structures; finally, finally cure the connection layer and the respective micro-structures on the carrier substrate embryo, and remove the pressing plate after the connection layer and the respective micro-structures are finally cured, thereby obtaining a Micro-LED chip carrier substrate; Wherein the micro-structure includes a column body having one end connected to the front surface of the connection layer and a cover body connected to the other end of the column body, the diameter of the cover body is larger than the diameter of the column body, and the cross-section of the micro-structure is T-shaped.

5. The manufacturing method according to claim 4, characterized in that: The method for manufacturing the forming mold includes the following sequential steps: Step S1: Etch an inverted template so that convex columns arranged in an array are formed on the front surface of the etched inverted template, and perform plasma cleaning on the etched inverted template; Step S2: Coat a liquid mold layer on the front surface of the inverted template, the mold layer can be cured, and the liquid mold layer covers the convex columns on the front surface of the inverted template; then place a mold plate on the liquid mold layer so that the mold plate contacts the mold layer, and use a support member to support the mold plate so that a gap is formed between the mold plate and the inverted template, thereby obtaining a semi-finished forming mold; Step S3: Cure the mold layer in the semi-finished forming mold, the cured mold layer is connected to the mold plate, and the cured mold layer has a plurality of the grooves for sleeving the convex columns; Step S4: Remove the inverted template and the support member, thereby obtaining the forming mold.

6. The manufacturing method according to claim 4 or 5, characterized in that: The method for manufacturing the carrier substrate embryo is: spin-coat a curable forming layer on the front surface of a substrate, and slightly cure the forming layer, thereby obtaining the carrier substrate embryo.

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