Driving substrate, micro LED transfer device and transfer method

Abstract

This application provides a drive substrate, a transfer device for a micro LED, and a transfer method thereof. A binding metal layer (21) is disposed on the side surface of the drive substrate (2), and a positioning layer (22) is disposed around the binding metal layer (21), and the width of the positioning layer (22) at a position away from the drive substrate (2) is smaller than the width of the positioning layer (22) at a position close to the drive substrate (2). This structure solves the problem of misalignment when transferring a micro LED to the drive substrate.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from Chinese patent application having application number 202211400586.1, filed on November 9, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of display panels, and in particular to a driving substrate, a micro LED transfer device and a transfer method thereof. [Background technology]

[0003] With the development of photoelectric display technology and semiconductor manufacturing technology, organic light emitting diode (OLED) and liquid crystal display (LCD) display technologies are already being mass-produced on a large scale, and micro LED display technology is also under development.

[0004] Micro LED display technology is considered to be the best display technology in the future due to its high stability, long life, good display effect and high resolution.

[0005] The manufacturing process of a micro LED panel requires transferring millions to tens of millions of micro LED chips from a growth substrate to a driving backplane, which is a large-scale transfer. When LEDs are transferred to a backplane using large-scale transfer technology, the adhesive layer on the transfer substrate is easily deformed, which can result in slight deviations from the design value in the alignment position between the adhesive layer and the backplane circuit. If the product resolution is high and the alignment position area is small, the electrodes of the LED chips may not be accurately aligned with the alignment position, resulting in transfer defects. Summary of the Invention

[0006] The main technical problem to be solved by this application is to provide a pixel driving substrate, a micro LED transfer device and a transfer method thereof, which enable the light emitting element to always operate in a higher efficiency range.

[0007] In order to solve the above technical problems, the first technical solution adopted by the present application provides a drive substrate, in which a binding metal layer is installed on a side surface of the drive substrate, and a positioning layer is installed around the binding metal layer, and the width of the positioning layer at a position away from the drive substrate is smaller than the width of the positioning layer at a position close to the drive substrate.

[0008] Here, the sidewall of the positioning layer is connected to and installed on the binding metal layer, and the sidewall of the positioning layer and the binding metal layer form a funnel-shaped or bowl-shaped crater mouth, and the opening of the crater mouth on the side away from the drive substrate is larger than the opening on the side closer to the drive substrate.

[0009] In order to solve the above technical problem, the second technical solution adopted by the present application further provides a micro LED transfer device, which includes a transfer substrate and a micro LED installed on the transfer substrate, and is used to transfer the micro LED to any of the driving substrates described in the first technical solution, wherein each of the micro LEDs includes two electrodes, the electrodes extending toward a side away from the transfer substrate, and one end of the electrode away from the transfer substrate is arranged in a gentle taper.

[0010] Here, a slope or a convex surface is formed on the surface of the electrode that is away from the transfer substrate.

[0011] Here, a positioning member adjacent to the LED is further installed on the side surface of the transfer substrate on which the LED is installed, and the positioning member is composed of two funnel-shaped fixing members, and the two funnel-shaped fixing members are installed adjacent to each other so as to form a groove that aligns with the positioning layer.

[0012] Here, a breaking member is installed between the positioning member and the micro LED, and the breaking member is connected to the positioning member and the micro LED, and is easily broken by the action of an external force.

[0013] Here, a support member is placed between two electrodes of the same micro LED and engaged with the positioning layer between two adjacent binding metal layers.

[0014] Here, an adhesive layer is further provided between the transfer substrate and the micro LED, and the micro LED is adhered to the side surface of the transfer substrate via the adhesive layer.

[0015] In order to solve the above technical problems, a second technical solution adopted by the present application further provides a micro LED transfer method, wherein the micro LED includes an LED chip and a first electrode and a second electrode formed on a surface of the LED chip, and the micro LED is disposed on a transfer substrate, the micro LED transfer method including the steps of: providing a drive substrate; forming a bonding metal layer on a side surface of the drive substrate; forming a positioning layer around the binding metal layer, wherein the width of the positioning layer at a position away from the drive substrate is smaller than the width of the positioning layer at a position close to the drive substrate; placing the side of the transfer substrate on which the first electrode and the second electrode are disposed facing the drive substrate, and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer; and removing the transfer substrate and transferring the micro LED from the transfer substrate to the drive substrate.

[0016] Here, after the step of placing the side of the transfer substrate on which the first electrode and the second electrode are installed facing the drive substrate and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer, the micro LED transfer method includes welding the binding metal layer to the first electrode and / or the second electrode under predetermined temperature conditions.

[0017] Here, an adhesive layer is installed between the transfer substrate and the LED chip, and the step of removing the transfer substrate includes using a laser or a thermal decomposition process to remove the adhesive layer and then removing the transfer substrate.

[0018] Here, the sidewalls of the positioning layer and the binding metal layer form a funnel-shaped crater mouth, and the step of placing the side of the transfer substrate on which the first electrode and the second electrode are installed facing the drive substrate and moving the first electrode and the second electrode in a direction toward the binding metal layer with the assistance of the positioning layer until they are aligned with the binding metal layer includes moving the first electrode and / or the second electrode in a direction toward the binding metal layer along the sidewalls of the positioning layer under the action of gravity.

[0019] Here, the step of positioning the side wall of the positioning layer and the binding metal layer to form a funnel-shaped volcanic mouth, positioning the side of the transfer substrate on which the first electrode and the second electrode are installed facing the drive substrate, and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer includes performing a magnetization process on the first electrode and / or the second electrode, and moving the first electrode and / or the second electrode along the side wall of the positioning layer toward the binding metal layer with the action of a magnetic field force.

[0020] Here, the sidewalls of the positioning layer and the binding metal layer form a funnel-shaped crater mouth, and the step of placing the side of the transfer substrate on which the first electrode and the second electrode are installed facing the driving substrate and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer includes using a non-adhesive substrate to press the surface of the LED chip away from the first electrode and / or the second electrode, and moving the first electrode and / or the second electrode along the sidewalls of the positioning layer toward the binding metal layer.

[0021] Here, a flexible support structure is further installed between the first electrode and the second electrode, and the step of using the non-adhesive substrate to press the surface of the LED chip away from the first electrode and / or the second electrode and moving the first electrode and / or the second electrode along the side wall of the positioning layer in a direction toward the binding metal layer further includes deforming the flexible support structure with an external force, so that the flexible support structure engages with the positioning layer and fixes the LED chip.

[0022] Here, the material of the flexible support structure is an organic material containing an acidic group.

[0023] Here, the step of removing the transfer substrate further includes the step of removing the flexible support structure using an alkaline solution.

[0024] Here, a positioning member consisting of two funnel-shaped fixing members is further installed on both sides of the LED chip, and the positioning member is connected to the micro LED by a breaking member. After the step of removing the transfer substrate, the micro LED transfer method includes removing the positioning member using an adhesive substrate having an adhesive strength greater than the breaking strength of the breaking member and the LED chip, and the adhesive strength of the adhesive substrate is less than the fixing strength between the binding metal layer and the first electrode and / or the second electrode.

[0025] Here, the material of the binding metal layer is indium / tin metal.

[0026] Here, the step of forming a binding metal layer on the side surface of the driving substrate includes forming a binding metal layer on the side surface of the driving substrate by a deposition process.

[0027] The beneficial effects of the present application are as follows: The present application provides a driving substrate, a micro LED transfer device, and a transfer method thereof, in which a positioning layer is disposed around a binding metal layer disposed on the driving substrate, so that the width of the positioning layer away from the driving substrate is smaller than the width of the positioning layer close to the driving substrate, thereby forming a slope that is narrow at the top and wide at the bottom, which can help to achieve alignment between the first electrode or second electrode of the LED chip and the binding metal layer. [Brief explanation of the drawings]

[0028] In order to more clearly describe the technical solutions in the embodiments of the present application, the following briefly describes the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. Those skilled in the art can obtain other drawings from these drawings without any creative efforts. [Figure 1] 1 is a structural schematic diagram of the micro LED of the present application; [Figure 2] 1 is a structural schematic diagram of a first embodiment of a driving substrate of the present application. [Figure 3] FIG. 2 is a top schematic view of one embodiment of a drive substrate of the present application. [Figure 4] FIG. 4 is a structural schematic diagram of a second embodiment of a driving substrate of the present application. [Figure 5] 1 is a structural schematic diagram of an embodiment of a micro LED transfer system of the present application; FIG. [Figure 6] 1 is a structural schematic diagram of a first embodiment of a micro LED transfer device of the present application; FIG. [Figure 7]FIG. 2 is a structural schematic diagram of a second embodiment of the micro LED transfer device of the present application. [Figure 8] FIG. 10 is a structural schematic diagram of a third embodiment of the micro LED transfer device of the present application. [Figure 9] FIG. 10 is a structural schematic diagram of a fourth embodiment of the micro LED transfer device of the present application. [Figure 10] FIG. 10 is a structural schematic diagram of a fifth embodiment of the micro LED transfer device of the present application. [Figure 11] 1 is a flowchart of an embodiment of a micro LED transfer method of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, the technical solutions of the embodiments of the present application will be clearly and completely described with reference to the drawings of the embodiments of the present application. It should be understood that the described embodiments are only a part of the embodiments of the present application, but not all of them. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without inventive efforts fall within the scope of protection of the present application.

[0030] The terms used in the embodiments of this application are for the purpose of describing particular embodiments only and are not intended to limit the present application. As used in the embodiments and claims of this application, the singular forms "one," "the," and "the" are also intended to include the plural forms unless clearly indicated otherwise. "Plural types" typically include at least two types, but does not exclude the case where at least one type is included.

[0031] The term "and / or" used herein is merely intended to describe the association of related objects, and three relationships can exist. For example, A and / or B means that A exists alone, A and B exist simultaneously, or B exists alone. The character " / " used herein generally means that related objects are in an "or" relationship. Terms such as "first," "second," etc. in the specification and claims of this application and the above drawings are used to distinguish between similar objects and are not necessarily used to describe a specific order or chronological order.

[0032] As used herein, the terms "comprises," "having," and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, article of manufacture, or apparatus comprising a series of elements is not limited to the listed elements, but may optionally further include elements not listed, or may optionally further include other elements inherent in the process, method, article of manufacture, or apparatus.

[0033] All directional indications (e.g., up, down, left, right, front, back, etc.) in the embodiments of the present application are used to interpret the relative positional relationships, movement conditions, etc. between each part in a certain specific posture (e.g., as shown in the drawings), and when the specific posture changes, the directionality changes accordingly.

[0034] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described with reference to the embodiment may be included in at least one embodiment of the present application. The appearance of such a combination in various places in the specification does not necessarily refer to the same embodiment, nor does it mean that the embodiments are mutually exclusive, independent, or alternative embodiments. As will be understood by those skilled in the art, both explicitly and implicitly, the embodiments described herein can be combined with other embodiments.

[0035] The design concept of this application is as follows: To avoid the problem of misalignment occurring during the process of transferring the LED chip to the driving substrate, a positioning layer is installed on the driving substrate to help achieve alignment between the LED electrode and the metal layer installed on the driving substrate.

[0036] The present application provides a micro LED, specifically as shown in Figure 1, which is a structural schematic diagram of the micro LED of the present application. The micro LED 11, also called an LED or LED chip 11, includes an LED epitaxial layer 110 and an LED electrode, and the LED electrode includes a first electrode 111 and a second electrode 112.

[0037] The present application provides a driving substrate. Specifically, as shown in FIG. 2, FIG. 2 is a structural schematic diagram of a first embodiment of the driving substrate of the present application. As shown in FIG. 2, a binding metal layer 21 is disposed on the side of the driving substrate 2 close to the transfer substrate 1, and the binding metal layer 21 is disposed corresponding to the first electrode 111 and the second electrode 112, respectively. A positioning layer 22 is formed around the binding metal layer 21, and the width of the positioning layer 22 at a position away from the driving substrate 2 is smaller than the width of the positioning layer 22 at a position close to the driving substrate 2.

[0038] Here, the sidewalls of the positioning layer 22 form slopes with a predetermined angle, which allows the first electrode 111 and the second electrode 112 to easily approach and slide toward the binding metal layer 21 due to the action of the slopes, thereby realizing an aligned connection between the first electrode 111 and the second electrode 112 and the binding metal layer 21.

[0039] In a first specific embodiment, the sidewalls of the positioning layer 22 are disposed adjacent to the binding metal layer 21. In the first specific embodiment, the positioning layer 22 is disposed around each binding metal layer 21. Specifically, as shown in FIG. 3, FIG. 3 is a schematic top view of an embodiment of the drive substrate of the present application. As shown in FIG. 3, the sidewalls of the positioning layer 22 and the binding metal layer 21 form a funnel-shaped / bowl-shaped volcanic mouth. Here, the sidewalls of the positioning layer 22 refer to the sidewalls closest to the binding metal layer 21. The volcanic mouth is formed with the binding metal layer 21 as its bottom surface and the sidewalls of the positioning layer 22 as its wall surfaces. The opening of the volcanic mouth on the side away from the drive substrate 2 is larger than the opening of the volcanic mouth on the side closer to the drive substrate 2, i.e., a groove is formed that is wider at the top and narrower at the bottom. The bottom of the groove is the binding metal layer 21, thereby improving the alignment accuracy between the first electrode 111 and the second electrode 112 and the binding metal layer 21.

[0040] In this specific embodiment, the binding metal layer 21 has a certain height on the surface of the driving substrate 2, and the side of the binding metal layer 21 is perpendicular to the surface of the driving substrate 2. In other embodiments, the sidewall of the binding metal layer 21 and the surface of the driving substrate 2 form an inclined surface, which is not limited here.

[0041] In this specific embodiment, as shown in FIG. 2, the sidewall of the positioning layer 22 adjacent to the binding metal layer 21 is beveled.

[0042] In a second specific embodiment, the sidewall of the positioning layer 22 and the binding metal layer 21 form a bowl-shaped volcanic mouth. In this specific embodiment, the sidewall of the positioning layer 22 close to the binding metal layer 21 has an inward concave surface. Specifically, as further shown in FIG. 4, FIG. 4 is a structural schematic diagram of a second embodiment of the driving substrate of the present application. As shown in FIG. 4, the sidewall of the positioning layer 22 has an inward concave surface facing the binding metal layer 21. Similarly, the inward concave surface is disposed along the periphery of the binding metal layer 21. The inward concave sidewall of the positioning layer 22 provides a buffer region when the first electrode 111 and the second electrode 112 are slid toward the binding metal layer 21, preventing the first electrode 111 and the second electrode 112 from piercing the binding metal layer 21 due to excessive pressure or speed.

[0043] In this particular embodiment, the material of the binding metal layer 21 comprises a soft, easily pierced material such as tin or indium.

[0044] In other embodiments, the sidewalls of the positioning layer 22 are not connected to the binding metal layer 21. See specifically other embodiments and are not limited herein.

[0045] In the above embodiment, the first electrode 111 and the second electrode 112 are rectangular, or the sides of the first electrode 111 and the second electrode 112 that are close to the driving substrate 2 have diamond-shaped corners.

[0046] The present application further provides a micro LED transfer system, specifically as shown in Figure 5, which is a structural schematic diagram of an embodiment of the micro LED transfer system of the present application. As shown in Figure 5, the micro LED transfer system includes a micro LED transfer device and a driving substrate 2. The micro LED transfer device is used to transfer the micro LED onto the driving substrate 2. Here, the driving substrate 2 is the driving substrate in any of the above embodiments.

[0047] The micro LED transfer device includes a transfer substrate 1. Here, an LED chip 11 is placed / mounted on a side surface of the transfer substrate 1, and the LED chip 11 includes an LED epitaxial layer 110 and an LED electrode. Specifically, an adhesive layer 12 is provided between the transfer substrate 1 and the LED chip 11 to adhere the LED chip 11 to the side surface of the transfer substrate 1. Here, the LED epitaxial layer 110 is composed of a crystalline laminated layer. A first electrode 111 and a second electrode 112 are formed on the surface of each LED chip 11 away from the transfer substrate 1. Here, the first electrode 111 and the second electrode 112 are collectively referred to as LED electrodes. In one specific embodiment, multiple micro LEDs are arranged on the transfer substrate 1 to simultaneously transfer multiple micro LEDs / LED chips 11. Here, the multiple LED chips 11 are arranged in an array on the transfer substrate 1 and are spaced apart from each other, but this is not limited thereto.

[0048] Here, the LED electrode is placed in a gently tapered shape at one end away from the transfer substrate.

[0049] In the first embodiment, the first electrode 111 and the second electrode 112 have slopes formed on their ends away from the transfer substrate 1. Specifically, as shown in FIG. 6, FIG. 6 is a structural schematic diagram of the first embodiment of the micro LED transfer device of the present application. Here, the structure of the positioning layer 22 installed on the driving substrate 2 is as shown in FIG. 2, the sidewall of the positioning layer 22 is sloped, and the slopes of the first electrode 111 and the second electrode 112 match the slopes of the sidewall of the positioning layer 22, specifically, the inclination angles are the same, so that the first electrode 111 and the second electrode 112 can slide along the sidewall of the positioning layer 22.

[0050] The present application further provides a second micro LED transfer device, specifically as shown in FIG. 7, which is a structural schematic diagram of a second embodiment of the micro LED transfer device of the present application. As shown in the figure, convex surfaces are formed on the ends of the first electrode 111 and the second electrode 112 that are away from the transfer substrate 1. Here, the structure of the positioning layer 22 installed on the driving substrate 2 is as shown in FIG. 4, the sidewall of the positioning layer 22 has an inner concave surface, and the convex surfaces of the first electrode 111 and the second electrode 112 match the inner concave surface of the sidewall of the positioning layer 22.

[0051] As described in the above embodiment, the first electrode 111 and the second electrode 112 form a slope or convex surface that matches the sidewall of the positioning layer 22, improving the compatibility between the first electrode 111 and the second electrode 112 and the positioning layer 22 and preventing tilting or misalignment during the transfer process of the LED chip 11. In other embodiments, the LED electrodes do not need to be formed in a gradual tapered shape.

[0052] The present application further provides a third embodiment, and FIG. 8 is a structural schematic diagram of the third embodiment of the micro LED transfer apparatus of the present application. As shown in FIG. 8, a support member 13 is installed between a first electrode 111 and a second electrode 112. The support member 13 matches the structure of the positioning layer 22 between two adjacent binding metal layers 21, so that the support member 13 engages with the positioning layer 22 during the transfer process to fix the LED chip 11. In addition to the structure shown in FIG. 8, the support member 13 may also be a cone-shaped structure inserted between the two positioning layers 22 to support the micro LED, and is not limited thereto.

[0053] In this specific embodiment, the support member 13 is easily deformed and includes an organic material such as PI or PMMA. The support member 13 deforms as the first electrode 111 and the second electrode 112 approach the binding metal layer 21 and engages with the positioning layer 22, thereby fixing the LED chip 11 and preventing tilting of the LED chip 11. In this embodiment, the height of the support member 13 is the same as the height of the first electrode 111 and the second electrode 112. Here, the material of the support member 13 is an organic material containing a carboxy group, such as PI or PMMA. The support member 13 is easily removable in an alkaline solution, so that the support member 13 can be removed with an alkaline solution after the first electrode 111 and the second electrode 112 are aligned.

[0054] The present application further provides a fourth embodiment, and FIG. 9 is a structural schematic diagram of the fourth embodiment of the micro LED transfer device of the present application. As shown in FIG. 9, positioning members 14 are installed on both sides of the transfer substrate 1 corresponding to the LED chip 11. The positioning members 14 may have a double funnel-shaped or double bowl-shaped structure, or other structures. A groove is formed in the center of the positioning member 14, and the shape of the groove preferably matches the structure of the positioning layer 22.

[0055] In a specific embodiment, the positioning member 14 has a double funnel-shaped structure, that is, a groove is formed in the center of the positioning member 14. The groove may have a funnel-like or bowl-like shape as shown in FIG. 1, but is not limited thereto. In this embodiment, the positioning layer 22 disposed on the driving substrate 2 has a cone-like shape with a narrow top and a wide bottom, or other shapes. The positioning layer 22 matches the shape of the groove formed in the center of the positioning member 14, and the alignment between the LED chip 11 and the binding metal layer 21 can be achieved via the positioning layer 22 and the positioning member 14.

[0056] Compared to the structure in the previous embodiment, the positioning layer 22 in this embodiment is formed around every two binding metal layers 21 and is spaced apart from the binding metal layers so that the positioning layer 22 can be aligned with the positioning members 14 arranged on both sides of the LED chip.

[0057] The present application further provides a fifth embodiment, and Fig. 10 is a structural schematic diagram of the fifth embodiment of the micro LED transfer device of the present application. Fig. 10 is a further embodiment of Fig. 9. As shown in Fig. 10, the positioning member 14 is connected to the LED chip 11 by a breaking member 15, and the breaking member 15 is more easily broken by external force than the LED chip, which makes it easy to remove the positioning member 14 after alignment is completed.

[0058] Specifically, the breaking member 15 is connected to the positioning member 14 and the LED chip and is easily broken by an external force, thereby allowing the positioning member 14 to be easily removed. In other embodiments, the breaking member 15 may be another fixing member and can be easily removed after alignment is completed, and is not limited thereto. In this embodiment, the breaking member 15 may be removed by a weakly adhesive substrate, the adhesive strength of which is greater than the breaking force required to break the positioning member 14 and the LED chip 11 and less than the fixing force (welding force) between the binding metal layer 21 and the first electrode 111 and / or the second electrode 112.

[0059] In the above embodiment, the height / thickness of the positioning layer 22 disposed on the driving substrate 2 is smaller than the height / thickness of the first electrode 111 and / or the second electrode 112 disposed on the transfer substrate 1. Here, the heights of the first electrode 111 and the second electrode 112 are the same.

[0060] In order to achieve accurate alignment between the binding metal layer 21 and the LED electrode, the present application helps to achieve accurate alignment between the LED electrode and the binding metal layer 21 by forming a positioning layer having a slope around the binding metal layer 21.

[0061] The present application further provides a method for transferring a micro LED. Specifically, as shown in Figure 11, Figure 11 is a flowchart of an embodiment of the micro LED transfer method of the present application. Here, the micro LED includes an LED chip and a first electrode and a second electrode formed on the surface of the LED chip, and the LED chip is disposed on an array substrate. Here, the method for transferring a micro LED includes:

[0062] Step (S91): Provide a driving substrate.

[0063] Here, the driving substrate is a driving back plate such as LTPS-TFT, amorphous silicon TFT, IGZO-TFT, single crystal silicon MOS, etc., and is not limited thereto.

[0064] Step (S92): A binding metal layer is formed on the side surface of the driving substrate.

[0065] In a specific embodiment, a binding metal layer is formed on the surface of the driving substrate by vapor deposition, where the binding metal layer is disposed corresponding to the first electrode and the second electrode. In this embodiment, the binding metal layer is formed of a soft metal such as indium (In) / tin (Sn).

[0066] Step (S93): A positioning layer is formed around the binding metal layer.

[0067] Specifically, a positioning layer is formed around the binding metal layer using a film deposition technique or a photolithography technique, so that the positioning layer is positioned to incorporate the binding metal layer and can assist in aligning the LED electrode and the binding metal layer.

[0068] Here, the material of the positioning layer may be an organic material such as PI or PMMA, or an inorganic material such as SiNx or SiOx, and is not limited here.

[0069] In this embodiment, the width of the alignment layer formed at a position away from the driving substrate is smaller than the width at a position close to the driving substrate, i.e., the alignment layer is formed narrower at the top and wider at the bottom. The sidewalls of the alignment layer form a certain slope, which allows the first and second electrodes to slide to positions corresponding to the binding metal layer under the effect of gravity, thereby assisting in the alignment of the LED electrodes.

[0070] Step (S94): The side of the transfer substrate on which the first electrode and the second electrode are installed is placed toward the drive substrate, and the first electrode and the second electrode are moved in a direction approaching the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer.

[0071] Here, the alignment and connection includes alignment and connection, specifically welding the binding metal layer to the first electrode and the second electrode under a predetermined temperature condition, thereby fixing the LED chip via the binding metal layer, specifically melting the binding metal layer under a high temperature condition, causing the first electrode and the second electrode to sink into the binding metal layer and weld to the binding metal layer.

[0072] In this embodiment, the binding metal layer includes indium (In) / tin (Sn), where the melting temperature of indium is 160° C. or higher and the melting temperature of tin is 240° C. or higher. The preset temperature condition refers to a high temperature condition higher than 240° C.

[0073] In a specific embodiment, the positioning layer is disposed along the edge of the binding metal layer and connected to the edge of the binding metal layer. The sidewall of the positioning layer and the binding metal layer form a funnel-shaped volcanic mouth, a specific structure of which is shown in FIG. 1 . In a first specific embodiment, step S94 includes moving the first electrode and / or the second electrode along the sidewall of the positioning layer toward the binding metal layer under the action of gravity until the first electrode and / or the second electrode are aligned with the binding metal layer. In a second specific embodiment, step S94 includes magnetizing the first electrode and / or the second electrode and moving the first electrode and / or the second electrode along the sidewall of the positioning layer toward the binding metal layer under the action of a magnetic field to achieve alignment. In a third specific embodiment, step S94 includes using a non-adhesive substrate to press the backside of the LED chip, thereby moving the first electrode and / or the second electrode along the sidewall of the positioning layer toward the binding metal layer under pressure until the first electrode and / or the second electrode are aligned with the binding metal layer. Any of the above-described embodiments can achieve alignment and connection between the electrode and the binding metal layer.

[0074] Here, the sidewall of the positioning layer may be a slope, whereby the sidewall of the positioning layer forms a funnel-shaped volcanic mouth together with the binding metal layer, or the sidewall of the positioning layer may be an inward concave surface, whereby the sidewall of the positioning layer forms a bowl-shaped volcanic mouth together with the binding metal layer.

[0075] In another embodiment, a flexible support structure is further provided between the first electrode and the second electrode. Step S94 includes using an external force to deform the flexible support structure by pressure, engaging the flexible support structure with the positioning layer, and fixing the LED chip. This prevents tilting or other problems from occurring during the alignment process. The material of the flexible support structure includes an organic material formed with an acidic group, such as PI or PMMA. After step S94, a step of dissolving and removing the support structure using an alkaline solution is included. The flexible support structure may also be a support member in other structural embodiments, and is not limited thereto.

[0076] Step (S95): The transfer substrate is removed.

[0077] In one embodiment, an adhesive layer is further provided between the transfer substrate and the LED chip, where the adhesive layer has laser or thermal decomposition properties. After step S94, the process includes removing the transfer substrate by a laser or thermal decomposition process, thereby separating the transfer substrate from the LED chip and transferring the LED chip to the driving substrate.

[0078] In another specific embodiment, positioning members are installed on both sides of the LED chip, and the positioning members are connected to the micro LED via a breaking member. Step S95 includes removing the positioning members using an adhesive substrate whose adhesive strength is greater than the breaking force between the breaking member and the LED chip. Specifically, the breaking member and the LED chip are broken by adhesive action, thereby removing the breaking member and the positioning member after alignment is completed. The adhesive strength is also smaller than the fixing / welding force between the first electrode and the second electrode and the binding metal layer. In another embodiment, the breaking member may be a breaking groove, and the LED epitaxial layer is partially etched to form the breaking groove. Compared to the LED epitaxial layer, the layer forming the breaking member is very thin and easy to break, and the material of the breaking member is not limited here.

[0079] The beneficial effects of this application are as follows: By forming a positioning layer at least at the binding position installed on the driving substrate, the positioning layer and the binding metal layer form a funnel-shaped groove with an upper opening larger than the lower opening, thereby increasing the alignment area between the LED electrode and the binding metal layer, improving the alignment probability, and the slope of the positioning layer allows the LED electrode to be more accurately aligned with the binding metal layer. Furthermore, by installing a support member or positioning member on the transfer substrate and sharpening the electrode, the alignment accuracy between the LED electrode and the binding metal layer is improved.

[0080] The above are embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by utilizing the contents of the specification and drawings of the present application, or any directly or indirectly applicable to other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A drive substrate, comprising: a binding metal layer disposed on a side surface of the drive substrate; a positioning layer disposed around the binding metal layer; and a width of the positioning layer at a position away from the drive substrate that is smaller than a width of the positioning layer at a position closer to the drive substrate.

2. 2. The drive substrate of claim 1, wherein the sidewalls of the positioning layer are connected to and installed on the binding metal layer, and the sidewalls of the positioning layer and the binding metal layer form a funnel-shaped or bowl-shaped volcanic mouth, and the opening of the volcanic mouth on the side away from the drive substrate is larger than the opening on the side closer to the drive substrate.

3. A micro LED transfer device including a transfer substrate and a micro LED disposed on the transfer substrate, The micro LED is used to transfer the micro LED to the driving substrate according to any one of claims 1 to 2, A micro LED transfer apparatus, wherein each of the micro LEDs includes two electrodes, the electrodes extending toward a side away from the transfer substrate, and one end of the electrode away from the transfer substrate is arranged in a gentle taper.

4. The micro LED transfer apparatus according to claim 3 , wherein a slope or a convex surface is formed on the surface of the electrode away from the transfer substrate.

5. 4. The micro LED transfer apparatus of claim 3, wherein a positioning member adjacent to the micro LED is further provided on the side surface of the transfer substrate on which the micro LED is provided, the positioning member being composed of two funnel-shaped fixing members, the two funnel-shaped fixing members being arranged adjacent to each other so as to align with the positioning layer, and a recessed groove being formed.

6. 6. The micro LED transfer device according to claim 5, wherein a breaking member is installed between the positioning member and the micro LED, the breaking member being connected to the positioning member and the LED and being easily broken by the action of an external force.

7. 4. The micro LED transfer apparatus of claim 3, wherein a support member is disposed between two electrodes of the same micro LED and engaged with the positioning layer between two adjacent binding metal layers.

8. 4. The micro LED transfer apparatus according to claim 3, wherein an adhesive layer is further provided between the transfer substrate and the micro LED, and the micro LED is adhered to the side surface of the transfer substrate via the adhesive layer.

9. The micro LED includes an LED chip and a first electrode and a second electrode formed on a surface of the LED chip, and the micro LED is disposed on a transfer substrate; The micro LED transfer method includes: providing a drive substrate; forming a binding metal layer on a side surface of the driving substrate; forming a positioning layer around the binding metal layer, the width of the positioning layer at a position away from the drive substrate being smaller than the width of the positioning layer at a position closer to the drive substrate; placing the side of the transfer substrate on which the first electrode and the second electrode are provided facing the drive substrate, and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer; removing the transfer substrate and transferring the micro LEDs from the transfer substrate to the drive substrate; A micro LED transfer method comprising:

10. 10. The method for transferring a micro LED according to claim 9, further comprising: placing the side of the transfer substrate on which the first electrode and the second electrode are provided facing the drive substrate; and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer; and welding the binding metal layer to the first electrode and / or the second electrode under a preset temperature condition.

11. 10. The method of claim 9, wherein an adhesive layer is disposed between the transfer substrate and the LED chip, and the step of removing the transfer substrate comprises utilizing a laser or a thermal decomposition process to destroy the adhesive layer and remove the transfer substrate.

12. the sidewall of the positioning layer and the binding metal layer form a funnel-shaped volcanic mouth; 10. The micro LED transfer method of claim 9, wherein the step of placing the side of the transfer substrate on which the first electrode and the second electrode are provided facing the drive substrate and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode form alignment with the binding metal layer comprises moving the first electrode and / or the second electrode toward the binding metal layer along a sidewall of the positioning layer with the action of gravity.

13. the sidewall of the positioning layer and the binding metal layer form a funnel-shaped volcanic mouth; 10. The micro LED transfer method of claim 9, wherein the step of placing the side of the transfer substrate on which the first electrode and the second electrode are provided facing the drive substrate and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode are aligned with the binding metal layer includes performing a magnetization process on the first electrode and / or the second electrode, and moving the first electrode and / or the second electrode toward the binding metal layer along a sidewall of the positioning layer with the action of a magnetic field force.

14. the sidewall of the positioning layer and the binding metal layer form a funnel-shaped volcanic mouth; 10. The micro LED transfer method of claim 9, wherein the step of placing the side of the transfer substrate on which the first electrode and the second electrode are provided facing the drive substrate and moving the first electrode and the second electrode toward the binding metal layer with the assistance of the positioning layer until the first electrode and the second electrode form alignment with the binding metal layer comprises using a non-adhesive substrate to press a surface of the LED chip away from the first electrode and / or the second electrode, and moving the first electrode and / or the second electrode toward the binding metal layer along a sidewall of the positioning layer.

15. a flexible support structure is further disposed between the first electrode and the second electrode; 10. The micro LED transfer method of claim 9, wherein the step of using a non-adhesive substrate to press a surface of the LED chip away from the first electrode and / or the second electrode and moving the first electrode and / or the second electrode along the sidewall of the positioning layer in a direction toward the binding metal layer further comprises deforming the flexible support structure by an external force, causing the positioning layer to engage with the flexible support structure and fix the LED chip.

16. 16. The method of claim 15, wherein the material of the flexible support structure is an organic material containing acidic groups.

17. 20. The micro LED transfer method of claim 16, wherein removing the transfer substrate further comprises removing the flexible support structure using an alkaline solution.

18. A positioning member consisting of two funnel-shaped fixing members is provided on both sides of the LED chip, and the positioning member and the micro LED are connected via a breaking member; 10. The micro LED transfer method of claim 9, wherein after the step of removing the transfer substrate, the micro LED transfer method comprises removing the positioning member using an adhesive substrate having an adhesive strength greater than a breaking strength between the breaking member and the LED chip, and the adhesive strength of the adhesive substrate is less than a fixing strength between the binding metal layer and the first electrode and / or the second electrode.

19. 10. The method of claim 9, wherein the material of the binding metal layer is indium metal or tin metal.

20. 10. The method of claim 9, wherein forming a bonding metal layer on the side surface of the drive substrate comprises forming a bonding metal layer on the side surface of the drive substrate by a vapor deposition process.

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