Transparent flexible mini LED module and method of manufacturing the same

Abstract

The present application relates to a kind of transparent flexible mini LED module and its preparation method, which includes the following steps: forming a transparent electrode layer on one surface of the transparent flexible substrate, the transparent electrode layer has a plurality of pads;Covering a mask on the surface of the transparent electrode layer opposite to the transparent flexible substrate, the mask has a plurality of mesh holes penetrating through the mask, the position of the mesh hole corresponds to the pad one by one;Coating conductive paste on the surface of the mask opposite to the transparent electrode layer, so that the conductive paste flows out through the mesh hole and adheres to the pad, and then forms a conductive contact;Remove the mask;The positive and negative poles of mini LED are attached to one of the conductive contacts respectively, so that the mini LED is electrically connected with the transparent electrode layer, providing a kind of preparation method of transparent flexible mini LED module suitable for mass production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-emitting device display, in particular to a transparent flexible mini LED module and a preparation method thereof. BACKGROUND

[0002] Mini LED (micro light-emitting diode) display screen is a device that works by controlling the light-emitting of a micro LED matrix. In many use cases, it is required that the mini LED screen has the characteristics of light transmission, and it is also desired that the mini LED screen has the characteristics of flexible bending function so as to facilitate installation, transportation, etc. Therefore, it is necessary to consider how to form a mini LED matrix on a transparent flexible material.

[0003] In the conventional technology, the commonly used optical flexible material for making the substrate includes PI (Polyimide, polyimide), CPI (Colorless Polyimide, plastic colorless polyimide), PET (Polyethyleneterephthalate, polyethylene terephthalate), and the best bending property of these materials is CPI and PI, followed by PET. Among them, the PI material is not transparent and is commonly used to make FPC (Flexible Printed Circuit), which generally adopts a double-sided Cu (copper) plating layer and then uses etching and developing technology to make a circuit, and is not suitable for forming a transparent mini LED module. CPI is used as a bottom substrate in OLED (Organic Light-Emitting Diode, organic electroluminescent diode) and then evaporates R / G / B on it. The color of this bottom substrate is yellow, and it generally does not participate in the role of light transmission. The PET substrate is commonly used as a light transmission material for transparent touch electrodes, and generally uses ITO (Indium Tin Oxide, Indium Tin Oxide) and Cu on the surface of the material to make patterns and circuits by using etching and developing technology, but this ITO and Cu is not resistant to bending, and this design is rarely used for flexible structure. The conventional SMD (Surface Mount Device) mini LED is usually made by reserving pads on the etched circuit, and the etched circuit is a Cu circuit, which cannot be made transparent. In the above conventional technology, it is impossible to realize the SMD mini LED on the transparent flexible material, and it is impossible to obtain a transparent flexible mini LED module product. SUMMARY

[0004] Therefore, it is necessary to propose a preparation method of a transparent flexible mini LED module to solve the problem that the SMD mini LED cannot be realized on the transparent flexible material in the conventional technology. A transparent flexible mini LED module is also proposed.

[0005] The application discloses a preparation method of a transparent flexible mini LED module, and belongs to the technical field of LED module manufacturing.

[0006] The preparation method of the transparent flexible mini LED module comprises the following steps: providing a transparent flexible substrate; forming a transparent electrode layer on a surface of the transparent flexible substrate, wherein the transparent electrode layer is provided with a plurality of pads; covering a mask plate on a surface of the transparent electrode layer which is opposite to the transparent flexible substrate, wherein the mask plate is provided with a plurality of meshes which are arranged in one-to-one correspondence with the pads; coating conductive paste on a surface of the mask plate which is opposite to the transparent electrode layer, so that the conductive paste flows out of the meshes and is attached to the pads, thereby forming conductive contacts; removing the mask plate; and respectively attaching positive and negative poles of a mini LED to one of the conductive contacts, so that the mini LED is electrically connected to the transparent electrode layer.

[0006] The preparation method of the transparent flexible mini LED module can coat the conductive paste on the surface of the mask plate, so that the conductive paste flows out of the meshes and is firmly attached to the surface of the pad. The above method can not cause the thickness of the conductive paste on the surface of the pad, that is, the height of the conductive contact, to be uneven due to too low concentration of the conductive paste, thereby laying a good foundation for subsequent attachment of the mini LED. Meanwhile, the mask plate is used to assist in forming the conductive contacts, so that all the conductive contacts can be formed at one time, which is suitable for mass production, thereby providing a preparation method of the transparent flexible mini LED module which is suitable for mass production. The prepared transparent flexible mini LED module has the characteristics of transparency and bendability.

[0007] In one of the embodiments, the material of the transparent flexible substrate is PET polymer. The PET polymer has good light transmission and good flexibility, and can meet the dual requirements of light transmission and bendability.

[0008] In one of the embodiments, the transparent electrode layer comprises an electrode area and a bonding area, wherein the electrode area comprises a plurality of electrode lines arranged side by side, two ends of each electrode line are independently connected with a positive lead and a negative lead, the positive lead is led out from the edge of the electrode area and gathered in the bonding area, the negative lead is led out from the edge of the electrode area and gathered in the bonding area, each electrode line comprises a plurality of attachment areas arranged at intervals, each group of attachment areas comprises two pads separated from each other, and the adjacent attachment areas are connected by a wire; the step of attaching the positive and negative poles of the mini LED to the conductive contact respectively to electrically connect the mini LED and the transparent electrode layer specifically comprises: attaching one mini LED at each attachment area respectively, wherein the positive and negative poles of the mini LED are connected with the conductive contacts on the two pads in the attachment area respectively. After each attachment area of each electrode line is attached with a mini LED, each electrode line contains a plurality of mini LEDs connected in series, thereby providing larger power. Since a plurality of electrode lines are arranged in parallel, a mini LED matrix can be formed, thereby being applicable to a display such as an iPad display.

[0009] In one of the embodiments, the positive leads are gathered in the bonding area and form a positive area, the negative leads are gathered in the bonding area and form a negative area, and the positive area and the negative area are arranged side by side. The bonding area is used to connect with an external device, and the positive area and the negative area are arranged side by side, thereby simplifying the structure design of the connector of the external device.

[0010] In one of the embodiments, the step of forming a transparent electrode layer on the surface of the transparent flexible substrate, and the transparent electrode layer having a plurality of pads to which the mini LED is to be attached comprises: forming a nano-conductive layer on the surface of the transparent flexible substrate; and performing a patterning process on the nano-conductive layer to form the transparent electrode layer. The transparent electrode layer is processed by etching and developing and the like patterning technology, is suitable for batch processing, and can obtain a transparent electrode layer with any required shape structure.

[0011] In one of the embodiments, the nano-conductive layer is a nano-silver wire conductive layer. The nano-conductive layer is made of a nano-silver wire conductive layer, and the formed pattern structure is transparent in visual effect, thereby meeting the light transmission requirement.

[0012] In one of the embodiments, the roughness of the surface of the mask opposite to the transparent electrode layer is 5 nm-10 nm, and the roughness of the inner wall of the mesh hole is 5 nm-10 nm. When the conductive paste is coated, the conductive paste has good fluidity and can flow out of the mesh hole and adhere to the pads on the electrode line smoothly.

[0013] In one of the embodiments, the roughness of the surface of the mask facing the transparent electrode layer is 10-20 nm. When the mask is covered on the surface of the transparent electrode layer, the surface of the mask facing the transparent electrode layer is the contact surface with the transparent electrode layer, and the contact surface is set to have a relatively large roughness, so that the mask can be tightly attached to the transparent electrode layer. It has been verified that the roughness of 10-20 nm can make the mask tightly attached to the transparent electrode layer.

[0014] In one of the embodiments, the conductive paste is tin paste. The tin paste is widely available and easy to obtain, and is suitable for application in the coating process.

[0015] In one of the embodiments, before the step of covering the mask on the surface of the transparent electrode layer, the mask has a plurality of mesh holes penetrating through the mask, and the mesh holes correspond to the pads one by one, the method further comprises the steps of: forming a transparent insulating layer on the transparent electrode layer; and performing a patterning process on the insulating layer to form a plurality of opening regions corresponding to the pads, wherein the size of the opening region is larger than the size of the mesh hole in the direction parallel to the transparent electrode layer. Since the size of the opening region is larger than the size of the mesh hole, when the conductive paste flows into the opening region from the mesh hole, the conductive paste spreads in the horizontal direction, so that in the direction perpendicular to and away from the transparent electrode layer, the cross section of the conductive paste in the mesh hole and the opening region is inverted T-shaped, and the conductive paste has a large contact area with the pad and can be well attached to the pad.

[0016] A transparent flexible mini LED module is also provided, which is prepared by the method of any one of the preceding embodiments.

[0017] The transparent flexible mini LED module is prepared by simultaneously using the mask to assist in forming the conductive contacts, all the conductive contacts can be formed at one time, and the module is suitable for mass production and has the characteristics of transparency and bendability.

[0018] In one of the embodiments, the height of the conductive contact is 0.03-0.05 mm; the mini LED is attached to the conductive contact above the conductive contact, and there is a gap between the mini LED and the transparent flexible substrate. The gap between the mini LED and the transparent flexible substrate is beneficial to heat dissipation of the mini LED.

[0019] In one of the embodiments, in the direction perpendicular to and away from the transparent electrode layer, the cross section of the conductive contact is inverted T-shaped. In this case, the conductive contact has a large contact area with the pad and can be well attached to the pad. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The flow chart of the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application.

[0021] Figure 2 The structure schematic diagram in the preparation process of the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application Figure 1 .

[0022] Figure 3 The structure schematic diagram of the electrode line in the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application.

[0023] Figure 4 The structure schematic diagram in the preparation process of the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application Figure 2 .

[0024] Figure 5 The structure schematic diagram in the preparation process of the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application Figure 3 .

[0025] Figure 6 The top view schematic diagram of the product prepared by the preparation method of the transparent flexible mini LED module provided by the embodiment of the present application.

[0026] The elements in the figure are marked as follows:

[0027] 10, transparent flexible substrate; 20, transparent electrode layer; 210, electrode line; 211, attachment area; 2111, solder pad; 212, wire; 220, positive lead wire; 230, negative lead wire; 240, positive electrode area; 250, negative electrode area; 30, mini LED; 310, positive electrode; 40, mask; 410, mesh; 50, conductive paste; 60, conductive contact; 70, transparent insulating layer; 710, opening area. DETAILED DESCRIPTION

[0028] In order to make the above objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, a lot of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0029] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can also be present.

[0030] 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 in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this description, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0031] The conventional technology cannot realize the patching of mini LED on the transparent flexible material. In view of the above problems, the embodiment of the present application proposes a preparation method of a transparent flexible mini LED module, which is described in detail below in combination with the drawings.

[0032] Figure 1 The flow chart of the preparation method of the transparent flexible mini LED module in the embodiment of the present application is shown in FIG. 1. As shown in the figure, the preparation method comprises the following steps: Figure 1

[0033] S110, providing a transparent flexible substrate 10. In combination with FIG. 2, the transparent flexible substrate 10 is made of transparent and flexible material. Preferably, the transparent flexible substrate 10 can be made of transparent polymer, such as PET (polyethylene terephthalate), which can meet the dual requirements of light transmission and bendability, but the substrate is not limited to PET. Figure 2

[0034] S120, forming a transparent electrode layer 20 on the surface of the transparent flexible substrate 10, wherein the transparent electrode layer 20 has a plurality of pads 2111 to be attached to the mini LED 30.

[0035] As shown in FIG. 3, a transparent electrode layer 20 is formed on one surface of the transparent flexible substrate 10. As shown in FIG. 4, the transparent electrode layer 20 has a plurality of pads 2111 for attaching the mini LED 30. Specifically, the pads 2111 are square-shaped, and the size is 0.18mm x 0.08mm. Figure 2 Figure 6 As shown in FIG. 3, a transparent electrode layer 20 is formed on one surface of the transparent flexible substrate 10. As shown in FIG. 4, the transparent electrode layer 20 has a plurality of pads 2111 for attaching the mini LED 30. Specifically, the pads 2111 are square-shaped, and the size is 0.18mm x 0.08mm. Figure 3 Figure 6 As shown in FIG. 3, a transparent electrode layer 20 is formed on one surface of the transparent flexible substrate 10. As shown in FIG. 4, the transparent electrode layer 20 has a plurality of pads 2111 for attaching the mini LED 30. Specifically, the pads 2111 are square-shaped, and the size is 0.18mm x 0.08mm.

[0036] As shown in FIG. 3, a transparent electrode layer 20 is formed on one surface of the transparent flexible substrate 10. As shown in FIG. 4, the transparent electrode layer 20 has a plurality of pads 2111 for attaching the mini LED 30. Specifically, the pads 2111 are square-shaped, and the size is 0.18mm x 0.08mm. Figure 3 Figure 6 ​​​​​As shown, in an embodiment, the transparent electrode layer 20 can be formed by etching and developing technology, which includes an electrode area and a bonding area. The electrode area includes a plurality of electrode lines 210 arranged side by side, and each electrode line 210 has two ends independently connected with a positive lead 220 and a negative lead 230. The positive lead 220 is led out from the edge of the electrode area and gathered in the bonding area, and the negative lead 230 is led out from the edge of the electrode area and gathered in the bonding area. Each electrode line 210 includes a plurality of attachment areas 211 arranged at intervals, and each group of attachment areas 211 includes two pads 2111 separated from each other, and the adjacent attachment areas 211 are connected by a wire 212. In the bonding area, all the positive leads 220 are arranged in a straight line to form a positive area 240, all the negative leads 230 are arranged in a straight line to form a negative area 250, and the positive area 240 and the negative area 250 are arranged side by side. The bonding area is used to connect with external devices through a bonding process. The bonding area is used to connect with external devices, and the positive area 240 and the negative area 250 are arranged side by side, which simplifies the structure design of the connector of the external device.

[0037] In combination Figure 3 And Figure 5 As shown, each attachment area 211 includes two pads 2111 arranged at intervals, which are respectively used to connect with the positive electrode 310 and the negative electrode (not shown) of the mini LED 30. For the same electrode line 210, before the mini LED 30 is attached, since the adjacent pads 2111 are disconnected, the electrode line 210 is composed of a plurality of separated parts and is discontinuous. After the mini LED 30 is attached to each attachment area 211, the above-mentioned plurality of separated parts are connected in series through the mini LED 30. Specifically, in combination Figure 3 And Figure 6 As shown, 10 mini LEDs 30 are connected in series on each electrode line 210, and 6 electrode lines 210 form a parallel structure with 6 parallel units, and 60 mini LEDs 30 are attached to the transparent electrode layer 20 to form a 6x10 mini LED 30 matrix.

[0038] After the mini LED 30 is attached to each attachment area 211 of each electrode line 210, each electrode line 210 contains a plurality of mini LEDs 30 connected in series, thereby providing a larger power. Since a plurality of parallel electrode lines 210 are arranged, a mini LED 30 matrix can be formed, thereby being applied to a display, such as an iPad display.

[0039] Understandably, the number of electrode lines 210 is not limited to the aforementioned 6; it can be less than 6 or more than 6. Similarly, the number of mini LEDs 30 on each electrode line 210 is not limited to 10. Depending on the size of the transparent flexible substrate 10 and the size of the transparent electrode layer 20, the number of electrode lines 210 and mini LEDs 30 can be adjusted accordingly.

[0040] Furthermore, it is understood that the transparent electrode layer 20 is not limited to the structure described above. For example, all the electrode lines 210 can be configured to connect all the mini LEDs 30 in series. As another example, in the parallel structure with six parallel units described above, each parallel unit is an electrode line 210 connected in series with ten mini LEDs 30. In other embodiments, each parallel unit may further include multiple sub-parallel units connected in series, each sub-parallel unit comprising multiple mini LEDs 30 connected in parallel.

[0041] S130, a mask 40 is covered on the surface of the transparent electrode layer 20 opposite to the transparent flexible substrate 10. The mask 40 has a plurality of mesh holes 410 penetrating the mask 40, and the positions of the mesh holes 410 correspond one-to-one with the pads 2111.

[0042] like Figure 3 As shown, a mask 40 is applied to the transparent electrode layer 20. Specifically, the mask 40 is a mesh made of nano-silver with multiple mesh openings 410. The number of mesh openings 410 matches the number of pads 2111, and the distribution of the mesh openings 410 is the same as the distribution of the pads 2111. When the mask 40 covers the transparent electrode layer 20, the mesh openings 410 and pads 2111 correspond perfectly. Of course, the mask 40 is not limited to being made of nano-silver; it can be used as long as it forms multiple mesh openings 410 corresponding to the pads 2111.

[0043] S140. A conductive paste 50 is applied to the surface of the mask 40 opposite to the transparent electrode layer 20, so that the conductive paste 50 flows out through the mesh 410 and adheres to the pad 2111, thereby forming a conductive contact 60.

[0044] A conductive paste 50, such as solder paste, is coated onto the surface of the photomask 40. Coating methods include, but are not limited to, spin coating, roller coating, spray coating, blade coating, letterpress printing, and gravure printing. During the coating process, such as... Figure 2 As shown, conductive paste 50 flows out through mesh 410 and adheres to the surface of pad 2111, whereby it solidifies to form conductive contact 60. Figure 2 The conductive paste 50 in one mesh 410 is only schematically shown.

[0045] S150, remove the mask 40. As shown in Figure 4 After the mask 40 is removed, the conductive contacts 60 on the surface of the pads 2111 are exposed, and the subsequent mini LED 30 attachment process can be prepared.

[0046] S160, attach the mini LED 30 to the pad 2111, and electrically connect the mini LED 30 to the transparent electrode layer 20. Specifically, the positive and negative electrodes of each mini LED 30 are attached to the conductive contacts 60 on the two pads 2111 in the same group of attachment areas 211 through a silver glue dispensing process, so that the mini LED 30 is electrically connected to the transparent electrode layer 20. As shown in Figure 5 The positive electrode 310 of the mini LED 30 is attached to the conductive contact 60. The positive electrode 310 of the mini LED 30 is placed above the conductive contact 60, and then the silver glue is used to fix the mini LED 30. The situation when the negative electrode of the mini LED 30 is attached to the conductive contact 60 is exactly the same as Figure 5 as shown in the figure.

[0047] In the above preparation method, by coating the conductive paste 50 on the surface of the mask 40, the conductive paste 50 flows out through the mesh hole 410 and firmly adheres to the surface of the pad 2111. The above method will not cause the thickness of the conductive paste 50 on the surface of the pad 2111, i.e. the height of the conductive contact 60, to be uneven due to the low concentration of the conductive paste 50, thereby laying a good foundation for the subsequent attachment of the mini LED 30. At the same time, the mask 40 is used to assist in forming the conductive contact 60, which can form all the conductive contacts 60 at one time, which is suitable for mass production, thereby providing a preparation method for transparent and flexible mini LED 30 module suitable for mass production. The transparent and flexible mini LED 30 module prepared has the characteristics of transparency and flexibility.

[0048] In some embodiments, before step S120, that is, after the transparent electrode layer 20 is formed on the surface of the transparent and flexible substrate 10, the step of forming a plurality of pads 2111 to which the mini LED 30 is to be attached specifically includes: coating a nano-conductive layer on the surface of the transparent and flexible substrate 10; and performing a patterning process on the nano-conductive layer to form the transparent electrode layer 20. In specific implementation, the nano-conductive layer is a nano-silver (AGNW) conductive layer, as shown in Figure 6 The transparent electrode layer 20 formed includes a plurality of parallel electrode lines 210; as shown in Figure 3As shown, a plurality of pads 2111 are arranged on each electrode line 210 along the extension direction of the electrode line 210, and a positive electrode lead 220 and a negative electrode lead 230 are respectively and independently connected to the two ends of each electrode line 210, each electrode line 210 connects a plurality of mini LEDs 30 in series, and a plurality of electrode lines 210 with the mini LEDs 30 constitute a parallel structure.

[0049] In the embodiment, the transparent electrode layer 20 is formed by patterning the nanometer conductive layer, which is suitable for mass production. The patterning can be exposure, etching and development, and both positive etching and negative etching can be used.

[0050] In order to make the conductive paste 50 flow smoothly from the mesh hole 410 to the pad 2111. In some embodiments, the roughness of the surface of the mask 40 facing away from the transparent electrode layer 20 is 5-10 nm, and the roughness of the inner wall of the mesh hole 410 is 5-10 nm. When the conductive paste 50 is coated, the conductive paste 50 has good fluidity and can flow smoothly from the mesh hole 410 and adhere to the pad 2111 on the electrode line 210.

[0051] In the process of forming the conductive contact 60, it is desirable that the mask 40 is closely attached to the transparent electrode layer 20. To achieve the above purpose, in some embodiments, the roughness of the surface of the mask 40 facing the transparent electrode layer 20 is 10-20 nm. When the mask 40 is covered on the surface of the transparent electrode layer 20, the surface of the mask 40 facing the transparent electrode layer 20 is the contact surface with the transparent electrode layer 20, and the contact surface is set to have relatively large roughness, which can achieve close attachment of the mask 40 to the transparent electrode layer 20. It has been verified that within the above roughness of 10-20 nm, the mask 40 can be closely attached to the transparent electrode layer 20.

[0052] In a specific embodiment, the mask 40 is a nanometer silver mesh with mesh holes 410, and the transparent electrode layer 20 is a nanometer silver wire conductive layer. The roughness of the surface of the nanometer silver mesh facing away from the nanometer silver wire conductive layer is 6 nm, and the roughness of the inner wall of the mesh hole 410 is 6 nm; the roughness of the surface of the nanometer silver mesh facing the nanometer silver wire conductive layer is 15 nm. The nanometer silver mesh can be closely attached to the nanometer silver wire conductive layer, and when the conductive paste 50 is coated, the conductive paste 50 flows to the pad 2111 through the mesh hole 410 without obstruction, which is very smooth.

[0053] In some embodiments, prior to step 130, i.e., before covering the surface of the transparent electrode layer 20 with a mask 40 having a plurality of mesh holes 410 penetrating the mask 40, and before the position of the mesh holes 410 corresponding one-to-one with the pads 2111, the method further includes the steps of: forming a transparent insulating layer 70 on the transparent electrode layer 20; and patterning the insulating layer to form a plurality of opening regions 710 corresponding to the pads 2111, wherein the size of the opening region 710 is larger than the size of the mesh holes 410 along a direction parallel to the transparent electrode layer 20.

[0054] like Figure 2 As shown, after forming the transparent electrode layer 20, a transparent insulating layer 70 is then applied to the surface of the transparent electrode layer 20. The transparent insulating layer 70 serves to protect the transparent electrode layer 20. The transparent insulating layer 70 is made of a transparent polymer, such as PET. Then, the transparent insulating layer 70 is patterned using an etching and developing technique, such as... Figure 2 As shown, the transparent insulating layer 70 forms an opening region 710 corresponding to the position of the pad 2111, which is used to allow the conductive paste 50 flowing out from the mesh 410 to pass through. Figure 2 The diagram only schematically shows one opening area 710, but it should be noted that the number of opening areas 710 corresponds one-to-one with the number of pads 2111.

[0055] In specific implementation, the size of the opening region 710 is made larger than the size of the mesh 410 along a direction parallel to the transparent electrode layer 20. Here, "parallel to the transparent electrode layer 20" specifically refers to the direction parallel to the surface of the transparent electrode layer 20 opposite to the transparent flexible substrate 10. Figure 2 and Figure 4 In this context, the direction parallel to the transparent electrode layer 20 is horizontal. Since the size of the opening region 710 is larger than the size of the mesh 410, when the conductive paste 50 flows from the mesh 410 into the opening region 710, the conductive paste 50 diffuses horizontally in all directions. This results in the cross-section of the conductive paste 50 in the mesh 410 and the opening region 710 forming an inverted T-shape in the direction perpendicular to and away from the transparent electrode layer 20. In this case, the conductive paste 50 has a large contact area with the pad 2111 and can adhere well to the pad 2111. Here, the direction perpendicular to the transparent electrode layer 20 specifically refers to the direction perpendicular to and away from the transparent electrode layer 20 and the surface opposite to the transparent flexible substrate 10. Figure 2 and Figure 4In the above-mentioned direction vertically and away from the transparent electrode layer 20, the height of the conductive contact 60 is 0.03mm-0.05mm. The mini LED 30 is attached to the conductive contact 60 above the conductive contact 60, and the mini LED 30 has a gap with the transparent flexible substrate 10, which is beneficial to heat dissipation of the mini LED 30.

[0056] An embodiment of the present application also provides a transparent flexible mini LED module prepared by the method of any of the above-mentioned embodiments. The prepared transparent flexible mini LED module comprises a transparent substrate 10 and a transparent electrode layer 20 arranged on the surface of the transparent substrate 10, wherein the transparent electrode layer 20 has a plurality of pads 2111, each pad 2111 has a conductive contact 60, and the positive and negative electrodes of the mini LED 30 are respectively attached to a conductive contact 60, so that the mini LED 30 is electrically connected with the transparent electrode layer 20.

[0057] The transparent flexible mini LED module described above can use a mask to assist in forming the conductive contact 60, and all conductive contacts 60 can be formed at one time, which is suitable for mass production and has the characteristics of transparency and flexibility.

[0058] In some embodiments, the height of the conductive contact 60 in the prepared transparent flexible mini LED module is 0.03mm-0.05mm; the mini LED 30 is attached to the conductive contact 60 above the conductive contact 60, and the mini LED 30 has a gap with the transparent flexible substrate 10, which is beneficial to heat dissipation of the mini LED 30.

[0059] In some embodiments, in the direction vertically and away from the transparent electrode layer 20, the cross section of the conductive contact 60 is in the shape of an inverted T. In this case, the conductive contact 60 has a large contact area with the pad 2111 and can be well attached to the pad 2111.

[0060] The technical features of the above-mentioned embodiments can be combined in any way. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present application.

[0061] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of preparing a transparent flexible mini LED module, characterized by, The method comprises the following steps: providing a transparent flexible substrate; forming a transparent electrode layer on a surface of the transparent flexible substrate, the transparent electrode layer having a plurality of pads; forming a transparent insulating layer on the transparent electrode layer; performing a patterning process on the transparent insulating layer to form a plurality of opening regions corresponding to the pads; covering a mask on a surface of the transparent electrode layer opposite to the transparent flexible substrate, the mask having a plurality of meshes penetrating through the mask, the meshes corresponding to the pads one by one; applying a conductive paste on a surface of the mask opposite to the transparent electrode layer, so that the conductive paste flows out through the opening regions and the meshes and adheres to the pads, thereby forming conductive contacts, wherein in a direction parallel to the transparent electrode layer, the size of the opening regions is greater than the size of the meshes, so that the cross section of the conductive contacts is inverted T-shaped; removing the mask; attaching positive and negative poles of a mini LED to one of the conductive contacts respectively, so that the mini LED is electrically connected to the transparent electrode layer, and the mini LED has a gap with the transparent flexible substrate.

2. The method of claim 1, wherein the transparent flexible mini LED module is prepared by a process comprising: The material of the transparent flexible substrate is PET polymer. ​ 3. The method for fabricating a transparent flexible mini LED module according to claim 1, characterized in that, The transparent electrode layer comprises an electrode region and a bonding region, wherein the electrode region comprises a plurality of electrode lines arranged side by side, both ends of each electrode line are independently connected with positive and negative lead wires, the positive lead wires are led out from the edges of the electrode region and gathered in the bonding region, the negative lead wires are led out from the edges of the electrode region and gathered in the bonding region, each electrode line comprises a plurality of attachment regions arranged at intervals, each group of attachment regions comprises two pads separated from each other, and adjacent attachment regions are connected by wires. The step of attaching the positive and negative poles of the mini LED to one of the conductive contacts respectively, so that the mini LED is electrically connected to the transparent electrode layer, specifically comprises: attaching one mini LED at each attachment region respectively, wherein the positive and negative poles of the mini LED are connected to the conductive contacts on the two pads in the attachment region respectively.

4. The method for fabricating a transparent flexible mini LED module according to claim 3, characterized in that, The positive lead wires are gathered in the bonding region to form a positive region, and the negative lead wires are gathered in the bonding region to form a negative region, and the positive region and the negative region are arranged side by side.

5. The method of claim 1, wherein, The step of forming a transparent electrode layer on a surface of the transparent flexible substrate, the transparent electrode layer having a plurality of pads to be attached to mini LEDs, comprises: forming a nano-conductive layer on the surface of the transparent flexible substrate; performing a patterning process on the nano-conductive layer to form the transparent electrode layer.

6. The method of claim 5, wherein the transparent flexible mini LED module is prepared by a process comprising: The nano-conductive layer is a nano-silver wire conductive layer. ​ 7. A transparent flexible mini LED module, characterized in that, The transparent flexible mini LED module is prepared by the method of any one of claims 1-6.

8. The transparent flexible mini LED module of claim 7, wherein, The height of the conductive contact is 0.03mm-0.05mm; the mini LED is attached to the conductive contact above the conductive contact.

9. The transparent flexible mini LED module of claim 7, wherein, In a direction perpendicular to and away from the transparent electrode layer, the cross section of the conductive contact is inverted T-shaped.

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