Transfer method of light-emitting element and light-emitting structure

Abstract

The invention relates to a light-emitting element transfer method and a light-emitting structure, and relates to the technical field of display. The transfer method of the light-emitting element comprises the following steps: providing a first substrate, wherein the first substrate is provided with the light-emitting element; a second substrate is provided, a filling adhesive layer is arranged on the second substrate, and bubbles exist in the filling adhesive layer; the first substrate is moved to the position above the second substrate, so that the face, provided with the light-emitting element, of the first substrate is opposite to the face, provided with the filling adhesive layer, of the second substrate; irradiating the first substrate through laser, stripping the light-emitting element from the first substrate, and connecting the light-emitting element to the filling adhesive layer; the bubbles are filled in the filling adhesive layer, and after the filling adhesive layer is pressed, the bubbles can be broken along with heating and increase of gas pressure, so that the volume of the filling adhesive layer is reduced, the thickness of the filling adhesive layer is reduced, the light-emitting element can be conveniently pressed in, and the phenomena that the adhesive material is extruded and the adhesive material is accumulated during pressing are improved; the problem that the bonding effect of the light-emitting element is poor is solved.

Description

Technical Field

[0001] The present invention relates to the field of display technologies, and in particular to a method for transferring light-emitting elements and a light-emitting structure. Background Art

[0002] Micro LED display technology has excellent characteristics such as high brightness, high contrast, high reactivity, and power saving. However, one of the bottlenecks in mass-producing Micro LEDs currently is massive transfer. There are currently many massive transfer routes. To reduce the transfer steps and improve the transfer rate, existing technologies often adopt a non-contact transfer method.

[0003] The non-contact transfer method generally uses a backplane to make a UBM (metal layer), and then coats an adhesive layer so that the Micro LEDs can accurately fall onto the original position after being decomposed by laser. Then, a thermal pressing method is used to form a connection between the LEDs and the UBM. However, during the pressing process, after the upper pressing plate increases the pressure, there is no gap between the upper pressing plate and the backplane. Due to the extrusion effect of the adhesive material, the light-emitting elements will shift and a good bonding effect with the UBM cannot be achieved, and it will also cause the adhesive material to accumulate, resulting in uneven bright and dark lighting.

[0004] Regarding the above related technologies, there is a problem of poor bonding effect of the light-emitting elements. Summary of the Invention

[0005] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a method for transferring light-emitting elements and a light-emitting structure, aiming to solve the problem of poor bonding effect of the light-emitting elements.

[0006] A method for transferring light-emitting elements provided by the present application adopts the following technical solution: A method for transferring light-emitting elements, comprising the steps of:

[0007] Providing a first substrate, on which light-emitting elements are provided;

[0008] Providing a second substrate, on which a filling glue layer is provided, and there are bubbles in the filling glue layer;

[0009] Moving the first substrate above the second substrate so that the surface of the first substrate provided with the light-emitting elements is disposed opposite to the surface of the second substrate provided with the filling glue layer;

[0010] By irradiating the first substrate with a laser, peeling the light-emitting elements from the first substrate and receiving them on the filling glue layer;

[0011] Bonding the light-emitting elements to the second substrate by thermal pressing.

[0012] By adopting the above technical solution, the first substrate is placed above the second substrate, and the first substrate is irradiated with laser, so that the light-emitting element is separated from the first substrate, and the light-emitting element falls onto the filling adhesive layer, and then the light-emitting element is hot-pressed and bonded, and the filling adhesive layer is softened by heat, and finally the light-emitting element passes through the filling adhesive layer and is connected to the second substrate. Since the filling adhesive layer is filled with bubbles, after the filling adhesive layer is pressed, as the gas pressure increases, the bubbles will burst, thereby reducing the volume of the filling adhesive layer and the thickness of the filling adhesive layer, which is convenient for pressing the light-emitting element, and improves the phenomenon of the adhesive material being squeezed out and causing the adhesive material to accumulate during pressing, thereby solving the problem of poor bonding effect of the light-emitting element.

[0013] Optionally, after the first substrate is irradiated with laser to peel the light emitting element from the first substrate and attach it to the filling adhesive layer, the method further includes the following steps:

[0014] The second substrate carrying the light emitting element is placed in a sealed environment, and an inert gas is filled into the sealed environment.

[0015] By adopting the above technical solution, the enclosed space is filled with inert gas, so that the air in the enclosed space can be squeezed out, which is convenient for the subsequent bonding process between the light-emitting element and the electrode pad under pressurization and heating operations, and the inert gas chemical properties can be used to effectively prevent oxidation of the electrode pad.

[0016] Optionally, the step of bonding the light-emitting element to the second substrate by heat pressing specifically includes:

[0017] Providing a pressing plate, wherein a buffer layer is disposed on one side of the pressing plate;

[0018] Attaching the side of the laminated plate provided with the buffer layer to the light emitting surface of the light emitting element;

[0019] The light emitting element is continuously pressed by the pressing plate under a predetermined temperature and pressure, so that bubbles in the filling adhesive layer are ruptured by heat, and the light emitting element is bonded to the second substrate.

[0020] By adopting the above technical solution, the buffer layer can play a role of buffering and shock absorption, avoiding direct contact between the pressing plate and the light-emitting element, so that the pressing plate will not damage the light-emitting element during the process of squeezing the light-emitting element.

[0021] Optionally, the filling glue layer provided on the second substrate is prepared by the following steps:

[0022] Obtaining a glue material matrix and a dispersant for making the filling glue layer;

[0023] Adding the colloid matrix and the dispersant into a container;

[0024] An inert gas is introduced into the container and stirred and mixed to obtain a filled glue layer containing bubbles.

[0025] By adopting the above technical solution, the addition of the dispersant can improve and enhance the dispersion performance of the glue matrix, contribute to the crushing of particles and prevent the coagulation of the crushed particles, thereby maintaining the stability of the glue matrix. And the filled glue layer obtained through this preparation step contains bubbles. During the transfer process of the light-emitting element, after the filled glue layer is pressed, the bubbles burst, so that the volume of the filled glue layer decreases, improving the phenomenon that the glue material is extruded and piled up during pressing.

[0026] Optionally, the diameter of the bubbles contained in the filled glue layer is less than 4 microns.

[0027] By adopting the above technical solution, the diameter of the bubbles in the filled glue layer being less than 4 microns can prevent the light-emitting element from moving significantly when passing through the bubbles, which may affect the transfer of the light-emitting element.

[0028] Optionally, the volume ratio of the bubbles to the filled glue layer is between 2:5 and 4:7.

[0029] By adopting the above technical solution, the volume ratio of the bubbles to the filled glue layer being between 2:5 and 4:7 can prevent the surface of the filled glue layer from being broken by too large bubbles due to the too large volume ratio between the bubbles and the filled glue layer, resulting in pits on the surface of the filled glue layer and affecting the transfer of the light-emitting element.

[0030] Optionally, the glue matrix includes one or more of acrylic, epoxy, polyurethane, and silicone.

[0031] By adopting the above technical solution, the chemical properties of acrylic, epoxy, polyurethane, and silicone products are relatively stable and can maintain good stability in a heating environment.

[0032] Optionally, the inert gas includes any one or more of nitrogen, helium, or argon.

[0033] By adopting the above technical solution, selecting one or more of nitrogen, helium, or argon as the filling gas is on the one hand convenient for driving out the air in the container, and on the other hand, even in a high-temperature and high-pressure environment, these inert gases such as nitrogen, helium, and argon can maintain the stability of their own chemical properties.

[0034] A light-emitting structure is made by using the transfer method of the light-emitting element as described above, and includes:

[0035] A second substrate, on one side of which an electrode pad is provided;

[0036] A filling glue layer, the entire filling glue layer covers the side of the second substrate where the electrode pads are provided, and there are air bubbles in the filling glue layer;

[0037] A light-emitting element, the air bubbles in the filling glue layer are heated and burst under the action of hot pressing, so that the light-emitting element passes through the filling glue layer and is correspondingly bonded to the electrode pads.

[0038] By adopting the above technical solution, the glue of the filling glue layer extruded by the light-emitting electrode will accumulate around the light-emitting electrode, thereby increasing the connection stability between the light-emitting electrode and the electrode pads.

[0039] Optionally, the thickness of the filling glue layer is 5-7 microns.

[0040] By adopting the above technical solution, the thickness of the filling glue layer is 5-7 microns, which can keep the filling glue layer at a relatively small thickness while ensuring that the filling glue layer covers the motor pads, thereby weakening the extrusion effect of the glue material.

[0041] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0042] The first substrate is placed above the second substrate, and the first substrate is irradiated with laser light to separate the light-emitting element from the first substrate. The light-emitting element falls onto the filling glue layer, and then the light-emitting element is hot-pressed and bonded. The filling glue layer is softened by heating. Finally, the light-emitting element passes through the filling glue layer and is connected to the second substrate. Since the filling glue layer is filled with air bubbles, after the filling glue layer is pressed, as the heating progresses, the gas pressure increases and the air bubbles will burst, so that the volume of the filling glue layer decreases and the thickness of the filling glue layer decreases, which is convenient for the pressing-in of the light-emitting element, and improves the phenomenon that the glue material is extruded and piled up during pressing, and solves the problem of poor bonding effect of the light-emitting element. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0044] Figure 1 It is a flowchart of the method for transferring the light-emitting element in the embodiment of the present application.

[0045] Figure 2 It is a schematic structural diagram of laser irradiating the first substrate in the method for transferring the light-emitting element in the embodiment of the present application;

[0046] Figure 3It is a schematic structural diagram of a light-emitting element falling onto a second substrate in the transfer method of the light-emitting element in the embodiment of the present application;

[0047] Figure 4 It is a schematic structural diagram of bonding a light-emitting element to a second substrate by thermocompression in the transfer method of the light-emitting element in the embodiment of the present application;

[0048] Figure 5 It is a schematic structural diagram of electrical connection between a light-emitting element and an electrode pad in the transfer method of the light-emitting element in the embodiment of the present application;

[0049] Explanation of reference numerals: 1, first substrate; 2, second substrate; 21, electrode pad; 3, filling glue layer; 31, air bubble; 4, light-emitting element; 41, epitaxial layer; 42, light-emitting electrode; 5, laser; 6, buffer layer; 7, pressing plate. Detailed implementation manners

[0050] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0051] The following further describes the present application in detail with reference to the accompanying drawings of the specification.

[0052] The embodiment of the present application discloses a transfer method of a light-emitting element and a light-emitting structure.

[0053] As Figure 1 shown, a transfer method of a light-emitting element includes the steps:

[0054] S100. Provide a first substrate 1, and a light-emitting element 4 is arranged on the first substrate 1.

[0055] S200. Provide a second substrate 2, and a filling glue layer 3 is arranged on the second substrate 2, and air bubbles 31 exist in the filling glue layer 3.

[0056] S300. Move the first substrate 1 above the second substrate 2 so that the surface of the first substrate 1 with the light-emitting element 4 is arranged opposite to the surface of the second substrate 2 with the filling glue layer 3.

[0057] S400. Irradiate the first substrate 1 with a laser 5 to peel the light-emitting element 4 from the first substrate 1 and receive it on the filling glue layer 3.

[0058] S500. Bond the light-emitting element 4 to the second substrate 2 by thermocompression.

[0059] The first substrate 1 is placed above the second substrate 2, and the first substrate 1 is irradiated with a laser 5 so that the light-emitting element 4 is separated from the first substrate 1. The light-emitting element 4 drops onto the filling adhesive layer 3, and then the light-emitting element 4 is thermocompression bonded. The filling adhesive layer 3 is softened by heating, and finally the light-emitting element 4 passes through the filling adhesive layer 3 and is connected to the second substrate 2. Since the filling adhesive layer 3 is filled with air bubbles 31, after the filling adhesive layer 3 is pressed, as the heating progresses, the gas pressure increases, and the air bubbles 31 will burst, so that the volume of the filling adhesive layer 3 decreases and the thickness of the filling adhesive layer 3 decreases, facilitating the pressing-in of the light-emitting element 4 and improving the phenomenon that the adhesive material is extruded and piled up during pressing, thus solving the problem of poor bonding effect of the light-emitting element.

[0060] Furthermore, the method for transferring the light-emitting element specifically includes:

[0061] S100. Provide the first substrate 1, and the light-emitting element 4 is arranged on the first substrate 1.

[0062] As Figure 2 shown, specifically, for facilitating the subsequent laser 5 irradiation to separate the light-emitting element 4 from the first substrate 1, the first substrate 1 is a substrate with a certain transparency. For example, in the embodiment of the present invention, the first substrate 1 can be a sapphire substrate. There are multiple light-emitting elements 4, and the multiple light-emitting elements 4 are arranged in an array on the first substrate 1.

[0063] The light-emitting element 4 is a light-emitting diode, and the light-emitting element 4 can be any one of an organic light-emitting diode element, a Mini LED element, or a Micro LED element. In this embodiment, the multiple light-emitting elements 4 can emit multiple different colors of light or the same color of light, and the multiple light-emitting elements 4 are arranged in an array on the first substrate 1.

[0064] In a preferred embodiment, the light-emitting element 4 can emit three different colors, and the three light-emitting elements 4 are a red light-emitting diode, a green light-emitting diode, and a blue light-emitting diode respectively. It should be noted that the number and installation positions of the light-emitting elements 4 that can emit different colors on the first substrate 1 can be adjusted according to actual production needs, and no limitation is imposed thereon herein.

[0065] Furthermore, the light-emitting element 4 includes an epitaxial layer 41 and a light-emitting electrode 42. One side of the epitaxial layer 41 facing away from the second substrate 2 (i.e., the light-emitting surface of the epitaxial layer 41) is formed on the first substrate 1, and the light-emitting electrode 42 is arranged on the side of the epitaxial layer 41 close to the second substrate 2.

[0066] The epitaxial layer 41 includes an N-type semiconductor layer, a light-emitting layer, and a P-type semiconductor layer. The N-type semiconductor layer, the light-emitting layer, and the P-type semiconductor layer are sequentially stacked.

[0067] The light-emitting electrode 42 includes an N electrode and a P electrode. The N electrode is electrically connected to the N-type semiconductor layer, and the P electrode is electrically connected to the P-type semiconductor layer.

[0068] S200. Provide a second substrate 2, on which a filling glue layer 3 is provided, and air bubbles 31 exist in the filling glue layer 3.

[0069] As Figure 2 shown, specifically, the second substrate 2 is a thin-film transistor (TFT) backplane. An electrode pad 21 is provided on the side of the second substrate 2 facing the first substrate 1. The electrode pad 21 is used for electrically connecting to the light-emitting element 4. The entire filling glue layer 3 is coated on the second substrate 2 and wraps the electrode pad 21.

[0070] A plurality of electrode pads 21 are provided. The thicknesses of the plurality of electrode pads 21 on the second substrate 2 are the same, and the plurality of electrode pads 21 are arranged in an array on the second substrate 2. The number of electrode pads 21 is the same as the number of light-emitting electrodes 42, and the electrode pads 21 and the light-emitting electrodes 42 are in one-to-one correspondence.

[0071] The filling glue layer 3 is an elastic glue. The setting of the filling glue layer 3 facilitates the subsequent firm electrical connection between the light-emitting element 4 and the electrode pad 21, and the elastic property of the filling glue layer 3 itself can play a certain protective role for the light-emitting element 4 dropped from a height.

[0072] The filling glue layer 3 on the same side of the second substrate 2 as the light-emitting element 4 wraps the plurality of electrode pads 21. The filling glue layer 3 fills the gaps between the electrode pads 21. The thickness of the filling glue layer 3 is 5-7 microns, and the thickness of the filling glue layer 3 is 1-3 microns higher than that of the electrode pad 21.

[0073] The thickness of the filling glue layer is 5-7 microns, which can keep the thickness of the filling glue layer relatively small while ensuring that the electrode pads are covered by the filling glue layer, thereby weakening the extrusion effect of the glue material.

[0074] The thickness of the filling glue layer 3 is greater than that of the electrode pad 21, so that when the light-emitting element 4 falls onto the second substrate 2, it will not directly contact the electrode pad 21, but first land on the filling glue layer 3 for shock absorption and buffering, playing a certain protective role for the light-emitting element 4 and the electrode pad 21, and facilitating the normal subsequent electrical connection between the light-emitting element 4 and the electrode pad 21.

[0075] To give full play to the role of the filling glue layer 3, the filling glue layer 3 covers the outer surface of the second substrate 2, so that the filling glue layer 3 can wrap all the electrode pads 21 on the second substrate 2, protecting each light-emitting element 4 and each electrode pad 21 to ensure that each subsequent light-emitting element 4 can be smoothly electrically connected to each electrode pad 21.

[0076] The filling adhesive layer 3 is filled with dense bubbles 31, so that when the filling adhesive layer 3 is pressurized and heated, the bubbles 31 burst, reducing the volume of the filling adhesive layer 3 and making the filling adhesive layer 3 thinner, thereby improving the extrusion and stacking effect of the adhesive material during pressing to achieve a better bonding effect.

[0077] The gas in the bubble 31 is any inert gas of helium (He), argon (Ar) or nitrogen (N2). Due to the stability of the inert gas, even if the bubble 31 is broken, the gas in the bubble 31 will not react with the surrounding filling rubber layer 3.

[0078] S300 , moving the first substrate 1 to above the second substrate 2 , so that a surface of the first substrate 1 provided with the light emitting element 4 and a surface of the second substrate 2 provided with the filling adhesive layer 3 are arranged opposite to each other.

[0079] like Figure 2 As shown, specifically, the first substrate 1 is moved above the second substrate 2 until the light emitting element 4 contacts the filling glue layer 3. The present invention adopts a non-contact transfer method of laser transfer, and releases the light emitting element 4 by irradiation of laser 5, so that it falls onto the second substrate 2, and the transfer rate is relatively high.

[0080] Before using the laser 5 to separate the light-emitting element 4 from the first substrate 1, a positioning device is used to position the first substrate 1 and the second substrate 2 so that each light-emitting electrode 42 on each light-emitting element 4 can correspond one-to-one with each electrode pad 21 below, so that after the light-emitting element 4 is separated from the first substrate 1, the light-emitting element 4 can accurately fall into a preset position, so that each light-emitting electrode 42 can fall directly above the corresponding electrode pad 21.

[0081] S400 , irradiating the first substrate 1 with the laser 5 to peel off the light emitting element 4 from the first substrate 1 and attach it to the filling glue layer 3 .

[0082] like Figure 2 and Figure 3 As shown, specifically, when the laser 5 is used to irradiate the first substrate 1, the laser 5 is emitted from the side of the first substrate 1 away from the light-emitting element 4. Since the first substrate 1 is a sapphire substrate in the embodiment of the present invention, the laser 5 can pass through the first substrate 1 and be emitted to the junction of the first substrate 1 and the epitaxial layer 41 to separate the epitaxial layer 41 from the first substrate 1.

[0083] In a preferred embodiment, there are various ways to separate the light-emitting element 4 from the first substrate 1 by irradiating the first substrate 1 with the laser 5. By irradiating the first substrate 1 with the laser 5, the light-emitting elements 4 can fall one by one from the edge of the first substrate 1 onto the second substrate 2 in sequence, or two adjacent light-emitting elements 4 on the edge of the first substrate 1 can fall from the first substrate 1 onto the second substrate 2 in sequence, or they can fall from the edge of the first substrate 1 onto the second substrate 2 in the form of a 4×4 matrix. That is to say, the light-emitting elements 4 on the first substrate 1 can be laser-stripped by selective laser stripping, and the number of light-emitting elements 4 stripped each time depends on the size of the laser spot.

[0084] There is no limitation herein on the number of light-emitting elements 4 falling from the first substrate 1 each time when irradiated by the laser 5, the falling position, and the type category of the light-emitting elements 4 falling each time.

[0085] After step S400, the following steps are further included:

[0086] S10: Place the second substrate 2 carrying the light-emitting elements 4 in a closed environment and fill the closed environment with an inert gas.

[0087] Specifically, since the subsequent operation steps need to be carried out in a heated environment, and the electrode pads 21 on the second substrate 2 are used as UBMs, to prevent oxidation of the electrode pads 21 due to heat, before performing step S500, place the second substrate 2 carrying multiple light-emitting elements 4 in a closed environment and fill the closed environment with any one or more of nitrogen, helium, or argon as inert gases. In this embodiment, nitrogen can be selected as the inert gas to reduce costs.

[0088] The closed space is filled with an inert gas, so that the air in the closed space can be squeezed out. During the process of smoothly bonding the light-emitting elements 4 to the electrode pads 21 under pressure and heating, since the inert gas has an inactive chemical property, it can effectively prevent the electrode pads 21 from oxidizing.

[0089] S500: Bond the light-emitting elements 4 to the second substrate 2 by thermal pressing.

[0090] As Figure 4 and Figure 5 shown, specifically, a pressing plate 7 is provided on the side of the light-emitting element 4 facing away from the second substrate 2; a buffer layer 6 is provided on the side of the pressing plate 7 facing the light-emitting element 4.

[0091] Use a pressing plate 7 to perform hot pressing on the light-emitting element 4 that has fallen onto the second substrate 2, so that the light-emitting element 4 penetrates through the filling glue layer 3, and the light-emitting electrode 42 contacts the electrode pad 21 located in the filling glue layer 3 to achieve electrical connection between the light-emitting element 4 and the electrode pad 21.

[0092] A buffer layer 6 is provided between the light-emitting element 4 and the pressing plate 7.

[0093] Step S500 specifically includes the steps of:

[0094] S510. Provide a pressing plate 7, and a buffer layer 6 is provided on one side of the pressing plate 7.

[0095] Specifically, a pressing plate 7 is provided on the side of the light-emitting element 4 facing away from the second substrate 2; the pressing plate 7 is located directly above the light-emitting element 4, and the buffer layer 6 is provided on the side of the pressing plate 7 facing the light-emitting element 4.

[0096] The pressing plate 7 is one of a quartz glass plate and a sapphire plate. The pressing plate 7 can cover all the light-emitting elements 4 that have fallen onto the second substrate 2. Thus, the pressing plate 7 can simultaneously extrude a plurality of light-emitting elements 4 and simultaneously move a plurality of light-emitting elements 4 in the direction towards the second substrate 2, so that in subsequent steps, the light-emitting electrodes 42 on each light-emitting element 4 can penetrate through the filling glue layer 3 and contact the corresponding electrode pads 21 to achieve electrical connection between the light-emitting element 4 and the electrode pad 21.

[0097] The material of the buffer layer 6 is a silicone-based soft glue material. The buffer layer 6 is provided between the light-emitting element 4 and the pressing plate 7, and the pressing plate 7 extrudes the light-emitting element 4 through the conduction of the buffer layer 6.

[0098] The buffer layer 6 can play a role in buffering and shock absorption, avoiding direct contact between the pressing plate 7 and the light-emitting element 4, so that the pressing plate 7 does not damage the light-emitting element 4 during the extrusion process of the light-emitting element 4.

[0099] S520. Attach the side of the pressing plate 7 provided with the buffer layer 6 to the light-emitting surface of the light-emitting element 4.

[0100] Specifically, attach the side of the pressing plate 7 provided with the buffer layer 6 to the light-emitting surface of the light-emitting element 4, so that the pressing plate 7 can apply force to continuously press the light-emitting element 4 later.

[0101] S530. Under a predetermined temperature and pressure, continuously press the light-emitting element 4 through the pressing plate 7, so that the bubbles 31 in the filling glue layer 3 are heated and burst, and the light-emitting element 4 is bonded to the second substrate 2.

[0102] Specifically, under a predetermined temperature and pressure, use the pressing plate 7 to continuously apply pressure to the light-emitting element 4 that has fallen onto the second substrate 2.

[0103] During the process of pressing the light-emitting element 4 by the pressing plate 7, since the temperature of the working environment is increased, the filling glue layer 3 is heated and softened. Part of the glue of the filling glue layer 3 facing the light-emitting electrode 42 will be squeezed and filled into the gap between the light-emitting electrodes 42. Under the squeezing action of the pressing plate 7 on the light-emitting element 4, the light-emitting element 4 can conveniently pass through the filling glue layer 3 and be electrically connected to the electrode pad 21, and finally the bonding of the light-emitting element 4 and the second substrate 2 is realized.

[0104] Moreover, due to the increase in the temperature of the working environment and the extrusion of the filling glue layer 3 by the light-emitting element 4, the gas pressure of the bubbles 31 in the filling glue layer 3 increases. Finally, the bubbles 31 will burst, reducing the volume of the filling glue layer 3, decreasing the thickness of the filling glue layer 3, and making the filling glue layer 3 thinner. This alleviates the phenomenon that the light-emitting element 4 is deflected during the process of moving towards the second substrate 2 due to the extrusion effect of the filling glue layer 3, thereby achieving a good bonding effect between the light-emitting electrode 42 and the electrode pad 21. Also, since the thickness of the filling glue layer 3 is reduced and the overall becomes thinner, the amount of glue extruded by the light-emitting element 4 during the pressing process is reduced, thereby reducing the accumulation amount of the glue at the gap between the light-emitting electrodes 42 and improving the phenomenon of uneven brightness caused by the accumulation of the glue.

[0105] It should be noted that since the pressing plate 7 presses multiple light-emitting elements 4 simultaneously, the height difference of the light-emitting elements 4 can be covered, making the pressure on each light-emitting element 4 uniform and ensuring that each light-emitting element 4 is at the same height to achieve a good bonding effect.

[0106] It should be noted that in this application, the filling glue layer 3 provided on the second substrate 2 is prepared through the following steps:

[0107] T100. Obtain the glue matrix and dispersant for making the filling glue layer 3.

[0108] Specifically, since the chemical properties of acrylic, epoxy, polyurethane, and silicone products are relatively stable and can maintain good stability in a heating environment. The glue matrix includes one or more of acrylic, epoxy, polyurethane, and silicone.

[0109] T200. Add the glue matrix and the dispersant into a container.

[0110] T300. Introduce an inert gas into the container and stir and mix to obtain the filling glue layer 3 containing bubbles 31.

[0111] Specifically, the container is a high-pressure container that can withstand high pressure. Before stirring the rubber material matrix and the dispersant in the container, the gas filled into the container is any one or more inert gases among nitrogen, helium, or argon. On the one hand, it is convenient to drive out the air in the container, and the relative molecular mass of the inert gas is less than that of air; on the other hand, since the inert gas is introduced, even in a high-temperature and high-pressure environment, it can maintain the stability of its own chemical properties.

[0112] Continuously introduce the inert gas until the container is filled with the inert gas, and then stir the mixture in the container to disperse and mix the inert gas into the mixture, and finally obtain the filling rubber layer 3 containing bubbles 31. Dense bubbles 31 filled with any one of He, Ar, and N2 are formed in the solidified filling rubber layer 3, and the density and size of the bubbles 31 are controlled according to the ratio of the dispersant and the rubber material and the stirring speed. In this embodiment, the volume ratio of the bubbles 31 to the volume of the rubber material matrix is between 2:5 and 4:7, and the diameter of the bubbles 31 is less than 4 microns.

[0113] The volume ratio of the bubbles 31 to the filling rubber layer 3 between 2:5 and 4:7 can prevent the surface of the filling rubber layer 3 from being pitted due to the too large volume ratio between the bubbles 31 and the filling rubber layer 3, resulting in the bursting of the too large bubbles 31 and affecting the transfer of the light-emitting element 4.

[0114] The diameter of the bubbles 31 in the filling rubber layer 3 is less than 4 microns, which can prevent the light-emitting element 4 from moving significantly when passing through the bubbles 31 and affecting the transfer of the light-emitting element 4.

[0115] As Figure 5 shown, the present application also provides a light-emitting structure, which is made by using the above-described method for transferring a light-emitting element.

[0116] The light-emitting structure includes a second substrate 2, a filling rubber layer 3, and a light-emitting element 4. An electrode pad 21 is provided on one side of the second substrate 2; the filling rubber layer 3 entirely covers the side of the second substrate 2 where the electrode pad 21 is provided, and there are bubbles 31 in the filling rubber layer 3. The bubbles 31 in the filling rubber layer 3 are heated and burst under the action of hot pressing, so that the light-emitting element 4 passes through the filling rubber layer 3 and is correspondingly bonded to the electrode pad 21.

[0117] In summary, a method for transferring a light-emitting element includes the steps of:

[0118] S100. Provide a first substrate 1, and a light-emitting element 4 is provided on the first substrate 1.

[0119] S200. Provide a second substrate 2, and a filling rubber layer 3 is provided on the second substrate 2, and there are bubbles 31 in the filling rubber layer 3.

[0120] S300. Move the first substrate 1 above the second substrate 2 so that the surface of the first substrate 1 provided with the light-emitting element 4 faces the surface of the second substrate 2 provided with the filling glue layer 3.

[0121] S400. Irradiate the first substrate 1 with a laser 5 to peel the light-emitting element 4 from the first substrate 1 and receive it onto the filling glue layer 3.

[0122] S500. Bond the light-emitting element 4 to the second substrate 2 by hot pressing.

[0123] The first substrate 1 is placed above the second substrate 2, and the first substrate 1 is irradiated with a laser 5 so that the light-emitting element 4 is separated from the first substrate 1. The light-emitting element 4 falls onto the filling glue layer 3. Then, hot pressing bonding is performed on the light-emitting element 4. The filling glue layer 3 is softened by heating. Finally, the light-emitting element 4 passes through the filling glue layer 3 and is connected to the second substrate 2. Since the filling glue layer 3 is filled with air bubbles 31, after the filling glue layer 3 is pressed, as the heating progresses, the gas pressure increases, and the air bubbles 31 will burst, so that the volume of the filling glue layer 3 decreases and the thickness of the filling glue layer 3 decreases, facilitating the pressing-in of the light-emitting element 4, and improving the phenomenon that the glue material is extruded and piled up during pressing, thus solving the problem of poor bonding effect of the light-emitting element 4.

[0124] It should be noted that, without conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0125] It should be noted that the present invention takes a transfer method and a light-emitting structure of a light-emitting element as an example to introduce the specific structure and working principle of the present invention. However, the application of the present invention is not limited to a transfer method and a light-emitting structure of a light-emitting element, and can also be applied to the production and use of other similar workpieces.

[0126] It should be understood that the present invention is not limited to the exact structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

[0127] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for transferring a light-emitting element, characterized in that, The method includes: Providing a first substrate, on which a light-emitting element is disposed; Providing a second substrate, on which a filling glue layer is disposed, and there are air bubbles in the filling glue layer; Moving the first substrate above the second substrate so that the surface of the first substrate with the light-emitting element is disposed opposite to the surface of the second substrate with the filling glue layer; By irradiating the first substrate with a laser, peeling the light-emitting element from the first substrate and receiving it on the filling glue layer; Bonding the light-emitting element to the second substrate by hot pressing.

2. The method for transferring a light-emitting element according to claim 1, characterized in that, After peeling the light-emitting element from the first substrate by irradiating the first substrate with a laser and receiving it on the filling glue layer, the method further includes the steps of: Placing the second substrate with the light-emitting element received thereon in a sealed environment and filling the sealed environment with an inert gas.

3. The method for transferring a light-emitting element according to claim 1, characterized in that, The step of bonding the light-emitting element to the second substrate by hot pressing specifically includes: Providing a pressing plate, on one side of which a buffer layer is disposed; Attaching the surface of the pressing plate with the buffer layer to the light-emitting surface of the light-emitting element; At a predetermined temperature and pressure, continuously pressing the light-emitting element through the pressing plate so that the air bubbles in the filling glue layer are heated and burst, and the light-emitting element is bonded to the second substrate.

4. The method for transferring a light-emitting element according to claim 1, characterized in that, The filling glue layer disposed on the second substrate is prepared by the following steps: Obtaining a glue material matrix and a dispersant for making the filling glue layer; Adding the glue material matrix and the dispersant into a container; Introducing an inert gas into the container and stirring and mixing to obtain a filling glue layer containing air bubbles.

5. The method for transferring a light-emitting element according to any one of claims 1-4, characterized in that, The diameter of the air bubbles contained in the filling glue layer is less than 4 microns.

6. The method for transferring a light-emitting element according to any one of claims 1-4, characterized in that, The volume ratio of the air bubbles to the filling glue layer is between 2:5 and 4:

7.

7. The method for transferring a light-emitting element according to claim 4, characterized in that, The glue material matrix includes one or more of acrylic, epoxy, polyurethane, and silicone.

8. The method for transferring a light-emitting element according to claim 2 or 4, characterized in that, The inert gas includes any one or more of nitrogen, helium, or argon.

9. A light-emitting structure is manufactured by using the method for transferring a light-emitting element according to any one of claims 1 to 8; characterized in that, The light-emitting structure includes: A second substrate, on one side of which an electrode pad is disposed; A filling glue layer, which entirely covers the side of the second substrate with the electrode pad, and there are air bubbles in the filling glue layer; A light-emitting element, the air bubbles in the filling glue layer are heated and burst under the action of hot pressing, so that the light-emitting element passes through the filling glue layer and is correspondingly bonded to the electrode pad.

10. The light-emitting structure according to claim 9, characterized in that, The thickness of the filling glue layer is 5-7 microns.

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