Disclosure of Invention
The application provides a micro light-emitting diode display panel and a preparation method thereof, which can solve the problems that in the prior art, the probability of micro light-emitting diodes transferring to a driving back plate is low, the micro light-emitting diodes are easy to misplace with the driving back plate electrode, and the micro light-emitting diodes cannot be adhered to the driving back plate.
The technical scheme adopted by the application is as follows: provided is a micro light emitting diode display panel including: the driving back plate is provided with a plurality of grooves on one surface, the bottom of each groove is provided with a first magnetic electrode, and the section size of each groove is gradually increased from the bottom to the top; the micro light-emitting diode is embedded into the groove of the driving back plate, one end of the micro light-emitting diode is provided with a second magnetic electrode, the second magnetic electrode is in contact with the first magnetic electrode, and the maximum cross-sectional dimension of the micro light-emitting diode is not smaller than that of the groove.
Furthermore, the cross-sectional size of the micro light-emitting diode gradually increases from one end provided with the second magnetic electrode to the other end, and the cross section with the largest size of the micro light-emitting diode and the cross section with the largest size of the groove are located on the same horizontal plane.
Furthermore, the micro light-emitting diode is of a prismatic table structure, and the groove is matched with the prismatic table structure; preferably, the frustum pyramid structure is a triangular frustum pyramid structure, a square frustum pyramid structure, a five-frustum pyramid structure or a six-frustum pyramid structure.
Further, the first magnetic electrode and the second magnetic electrode have the same cross-sectional dimension.
Further, the first magnetic electrode and the second magnetic electrode have ferromagnetism, and the first magnetic electrode and the second magnetic electrode include at least one magnetic material of iron, cobalt, and nickel.
Another technical scheme adopted by the application is as follows: a preparation method of a micro light-emitting diode display panel is provided, and the preparation method comprises the following steps: putting a driving back plate into a container filled with fluid, wherein a plurality of grooves are formed in one surface of the driving back plate, a first magnetic electrode is arranged at the bottom of each groove, and the section size of each groove is gradually increased from the bottom to the top; applying a magnetic field to the fluid; releasing a micro light-emitting diode into fluid, and stirring the fluid, wherein one end of the micro light-emitting diode is provided with a second magnetic electrode, the second magnetic electrode is in contact with the first magnetic electrode, and the maximum cross-sectional dimension of the micro light-emitting diode is not less than that of the groove; the first electrode and the second electrode generate mutually attractive acting force, and the micro light-emitting diode is embedded into the groove; removing the drive back plate from the fluid; and forming a micro light-emitting diode display panel based on the taken out driving back plate.
Further, the step of applying a magnetic field to the fluid specifically comprises: different magnetic poles are respectively applied above and below the container, and under the action of the magnetic poles, the surfaces of the first magnetic electrode and the second magnetic electrode generate different polarities.
Further, the stirring speed is 5 to 30 rpm.
Further, in the process of releasing the micro light-emitting diode into the fluid, when the micro light-emitting diode is embedded into the groove, the vertical distance of the micro light-emitting diode falling in the fluid is 3cm-15 cm.
Further, the step of removing the drive back plate from the fluid comprises: removing the driving back plate from the fluid while maintaining the state of applying the magnetic field to the fluid; the step of forming a micro-led display panel based on the taken out driving backplane includes: and stopping applying the magnetic field to the fluid, and forming a micro light-emitting diode display panel based on the taken-out driving back plate.
The beneficial effect of this application is: a first magnetic electrode for adsorbing a micro light-emitting diode with a second magnetic electrode is arranged at the bottom of a groove of a driving back plate, when the micro light-emitting diode is transferred by adopting fluid assembly, under the action of an applied magnetic field, the surfaces of the first magnetic electrode and the second magnetic electrode generate different polarities, so that the first magnetic electrode and the second magnetic electrode can be mutually attracted, the clustering phenomenon generated by the mutual attraction between the second magnetic electrodes is avoided, the micro light-emitting diode and the groove of the driving back plate realize accurate alignment, furthermore, the groove is arranged into a structure with the section size gradually increased from the bottom to the top, the section size of the micro light-emitting diode is gradually increased from one end provided with the second magnetic electrode to one end of a light-emitting surface, and the section size of one end of the light-emitting surface of the micro light-emitting diode is not smaller than the maximum section size of the groove, the precision that little emitting diode falls into the recess of drive backplate can be further improved, prevent that little emitting diode from falling into the recess with wrong orientation, prevent promptly that little emitting diode from falling into the recess of drive backplate in to shorten little emitting diode and fall into the time of drive backplate recess, increase little emitting diode reaches the probability of drive backplate recess, improve little emitting diode's transfer efficiency, realize little emitting diode's huge transfer. In addition, the micro light-emitting diodes are transferred by adopting fluid assembly, the fluid is used as a transfer medium, the micro light-emitting diodes are not damaged, the one-time transfer amount is large, and the transfer rate and efficiency are ensured.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first" and "second" in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature.
Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of an embodiment of a micro light emitting diode display panel according to the present application, and as shown in fig. 1, a micro light emitting diode display panel 300 provided in the present application includes a driving back plate 100 and micro light emitting diodes 200.
Wherein, a surface of the driving backplate 100 is provided with a plurality of grooves a, the bottom of the grooves a is provided with a first magnetic electrode, and the sectional dimension of the grooves a is gradually increased from the bottom to the top. In this embodiment, the cross-sectional dimension of the groove a is set to be a structure with a wide top and a narrow bottom, which is beneficial for the matching between the micro light emitting diode 200 and the groove a, so that the micro light emitting diode 200 can accurately fall into the groove a of the driving backboard 100 in a correct direction, and the micro light emitting diode 200 is prevented from falling into the groove a in a wrong direction, i.e., the micro light emitting diode 200 is prevented from being embedded into the groove a of the driving backboard 100 upside down, and the accuracy of the micro light emitting diode falling into the groove of the driving backboard is improved.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a driving backplate according to an embodiment of the present disclosure, in which fig. 2a) is a longitudinal sectional view of the driving backplate, and fig. 2b) is a top view of the driving backplate. As shown in fig. 2, a plurality of grooves a are formed on the substrate 100, a first magnetic electrode 110 is disposed at the bottom of the grooves a, the first magnetic electrode 110 has ferromagnetism, and the first magnetic electrode 110 includes a ferromagnetic material, wherein the ferromagnetic material may be at least one of iron, cobalt, and nickel, or other ferromagnetic materials, and is not limited in this respect.
Preferably, the structure of the groove is matched with a frustum structure, such as a triangular frustum structure, a quadrangular frustum structure, a pentagonal frustum structure, a hexagonal frustum structure, and the like. Further preferably, as shown in fig. 2, the groove a is a groove matching with the hexagonal frustum structure, and the groove a is a groove matching with the hexagonal frustum structure, so that the directionality of the micro light emitting diode 200 falling into the groove a can be further ensured, the stability of the micro light emitting diode in the groove a can be ensured, and the micro light emitting diode 200 is prevented from rotating under the action of the fluid after falling into the groove a. Of course, the groove a may also be a groove matching with other frustum structures, such as a triangular frustum structure, a quadrangular frustum structure, a pentagonal frustum structure, or a hexagonal frustum structure, and the like, and is not limited specifically herein.
Referring to fig. 3, fig. 3 is a schematic structural diagram of an embodiment of a micro light emitting diode of the present application, wherein fig. 3a) is a longitudinal sectional view of the micro light emitting diode, and fig. 3b) is a top view of the micro light emitting diode. As shown in fig. 3, the micro light emitting diode 200 includes an LED epitaxial layer 220 and a second magnetic electrode 210, and the second magnetic electrode 210 is disposed on the LED epitaxial layer 220. The second magnetic electrode 210 has ferromagnetism, and the second magnetic electrode 210 includes a ferromagnetic material, where the ferromagnetic material may be at least one of iron, cobalt, and nickel, or may be other ferromagnetic materials, and is not limited in particular.
Optionally, one end of the micro light emitting diode 200 is a light emitting surface, the other end away from the light emitting surface is provided with the second magnetic electrode 210, the cross-sectional size of the micro light emitting diode 200 gradually increases from the end provided with the second magnetic electrode 210 to the end of the light emitting surface, and the cross-sectional size of the end of the light emitting surface of the micro light emitting diode is not smaller than the maximum cross-sectional size of the groove a. Of course, the micro led 200 may also be a double-sided light emitting micro led, and is not limited herein.
Optionally, in the micro light emitting diode display panel of the present application, the cross-sectional size of the micro light emitting diode 200 gradually increases from one end provided with the second magnetic electrode 210 to the other end, and the cross-section with the largest size of the micro light emitting diode 200 and the cross-section with the largest size of the groove a are located on the same horizontal plane.
Preferably, the micro light emitting diode is of a frustum pyramid structure, and further preferably, as shown in fig. 3, the LED epitaxial layer 220 is of a frustum pyramid structure, and can be fitted with a groove fitted with the frustum pyramid structure, so that the micro light emitting diode can be more favorably embedded into the groove, the directionality of the micro light emitting diode 200 when falling into the groove a can be ensured, the stability of the micro light emitting diode in the groove a can be ensured, the micro light emitting diode can be better fitted with the groove, and the micro light emitting diode 200 can be prevented from rotating and other actions under the action of fluid after falling into the groove a. Of course, the LED epitaxial layer 220 may also have other truncated pyramid structures, such as a triangular truncated pyramid structure, a quadrangular truncated pyramid structure, a pentagonal truncated pyramid structure, or a hexagonal truncated pyramid structure, and the like, and is matched with the groove a, which is not limited herein.
Further, the micro light emitting diodes 200 are embedded in the groove a of the driving backplate 100, and the outline of the micro light emitting diodes 200 is matched with the side wall of the groove a, so that the micro light emitting diodes 200 can smoothly fall into the groove a of the driving backplate 100, the directionality of the micro light emitting diodes 200 falling into the groove a can be ensured, the stability of the micro light emitting diodes 200 in the groove a can be ensured, the micro light emitting diodes 200 can be prevented from falling into the groove a in a wrong direction, that is, the micro light emitting diodes 200 can be prevented from being inversely embedded into the groove a of the driving backplate 100.
Optionally, in the above embodiment, one end of the micro light emitting diode 200 is a light emitting surface, the second magnetic electrode 210 is disposed at the other end away from the light emitting surface, and when the micro light emitting diode 200 is transferred by fluid assembly, under the action of an applied magnetic field, the surfaces of the first magnetic electrode 110 and the second magnetic electrode 210 generate different polarities, so that the first magnetic electrode 110 and the second magnetic electrode 210 are attracted to each other, and a cluster phenomenon generated by the attraction between the second magnetic electrodes 210 is avoided, so that the micro light emitting diode 200 and the groove a of the driving backplane 100 are accurately aligned, thereby shortening the time for the micro light emitting diode to fall into the groove of the driving backplane, increasing the probability for the micro light emitting diode to reach the groove of the driving backplane, improving the transfer efficiency of the micro light emitting diode, and realizing mass transfer.
In the above embodiment, it is preferable that the first magnetic electrode 110 and the second magnetic electrode 210 have the same cross-sectional size. The cross-sectional dimensions of the first magnetic electrode 110 and the second magnetic electrode 210 are the same, so that the micro light emitting diode 200 is arranged opposite to the groove a of the driving back plate 100, the micro light emitting diode 200 is uniformly distributed on the driving back plate 100, and the bonding force between the micro light emitting diode 200 and the driving back plate 100 under the action of the magnetic field is strongest. Of course, the cross-sectional dimensions of the first magnetic electrode 110 and the second magnetic electrode 210 may also be different, and are not limited herein. It should be noted that, the same size means the same shape, for example, the cross-sectional shape of the first magnetic electrode 110 is a circle, and the cross-sectional shape of the second magnetic electrode 210 is also a circle, but the cross-sectional shapes are the same and do not mean that the cross-sectional areas are the same, and the cross-sectional areas of the first magnetic electrode 110 and the second magnetic electrode 210 may be different or the same, which is not limited herein, and further, preferably, the cross-sectional areas of the first magnetic electrode and the second magnetic electrode are the same, so as to ensure that the bonding force between the micro light emitting diode 200 and the driving back plate 100 under the action of the magnetic field is strongest.
Referring to fig. 4, fig. 4 is a schematic flow chart illustrating a method for manufacturing a micro light emitting diode display panel according to an embodiment of the present disclosure. The micro leds 300 mentioned in the present application may specifically include red micro leds, green micro leds and blue micro leds, and a transmission assembly (not shown) may also be used in the micro led manufacturing process for realizing the transfer of the micro leds in the fluid process. Wherein the transmission assembly may be a mechanical arm or a vacuum nozzle, and is not limited herein. And before the micro light-emitting diode display panel is prepared, the method further comprises the following steps:
s100, preparing a plurality of micro light emitting diodes on an original substrate.
Wherein the original substrate may be a laser transparent substrate, such as a sapphire substrate, a silicon carbide (SiC) substrate, etc., and is not particularly limited herein.
With reference to the specific structure of the micro light emitting diode in fig. 3, step S100 in this embodiment may specifically include:
the LED epitaxial layer 220 is prepared and formed on the original substrate, and then the magnetic material is laid on the LED epitaxial layer 220 to form the second magnetic electrode 210, wherein the magnetic material may be laid by using a physical vapor deposition technique. It can be understood that the inside of the magnetic material is divided into a plurality of tiny regions, each tiny region is called a magnetic domain, each magnetic domain has its own magnetic moment (tiny magnetic field), generally, the magnetic moment directions of the magnetic domains are different, the magnetic fields cancel each other out, and the whole magnetic material does not show magnetism to the outside. When the magnetic material is put into a magnetic field, under the action of an external magnetic field, the magnetic moment directions of all magnetic domains tend to be consistent, and the whole magnetic material shows magnetism outwards. The magnetic material is a ferromagnetic material, which may be at least one of iron, cobalt, and nickel, or other ferromagnetic materials, and is not limited specifically herein.
And S110, stripping the micro light-emitting diode from the original substrate.
Further peel off a plurality of little emitting diode 300 from original substrate through the mode of laser peeling off to in conveniently putting into suspension fluid, the suspension can adopt easily volatile, get rid of totally, handle simple and convenient acetone solution easily in this application. Of course, in other embodiments, the suspension may be any one of ethanol, polyol, halogenated hydrocarbon or water, and is not specifically limited herein.
It is understood that steps S100-S110 are not essential to implementing the present invention, and may be modified or omitted by those skilled in the art according to the actual use situation.
With reference to fig. 5, fig. 5 is a schematic view of a scene of an embodiment of a method for manufacturing a micro light emitting diode according to the present application.
S120, the driving back plate is placed into a container containing fluid, a plurality of grooves are formed in one surface of the driving back plate, a first magnetic electrode is arranged at the bottom of each groove, and the cross section size of each groove is gradually increased from the bottom to the top.
And S130, applying a magnetic field to the fluid.
Alternatively, different magnetic poles may be applied above and below the container containing the fluid, respectively, and the surfaces of the first magnetic electrode and the second magnetic electrode generate different polarities under the action of the magnetic poles. The magnetic poles can be obtained by electrifying the electromagnetic coils, namely, the electromagnetic coils are respectively arranged at the upper end and the lower end of the fluid, and the current with different directions is respectively introduced into the electromagnetic coils arranged at the upper end and the lower end, so that different magnetic poles are generated at the upper end and the lower end of the fluid; the magnetic poles may be obtained by placing two magnets at the upper and lower ends of the fluid, respectively, such that the N-pole of the magnet placed at the upper end of the fluid faces the fluid and the S-pole of the magnet placed at the lower end of the fluid faces the fluid, or such that the S-pole of the magnet placed at the upper end of the fluid faces the fluid and the N-pole of the magnet placed at the lower end of the fluid faces the fluid.
Specifically, as shown in fig. 5, an N pole is applied to the upper end of the fluid, an S pole is applied to the lower end of the fluid, the N pole and the S pole are arranged oppositely, and under the action of the N pole and the S pole, the first magnetic electrode 110 and the second magnetic electrode 210 generate ferromagnetism, so that the surface of the first magnetic electrode 110 away from the bottom of the groove a is represented as the N pole, that is, the upper surface of the first magnetic electrode 110 is represented as the N pole, and the surface of the second magnetic electrode 210 away from the LED epitaxial wafer 220 is represented as the S pole, that is, the lower surface of the second magnetic electrode 210 is represented as the S pole. Since the upper surface of the first magnetic electrode 110 and the lower surface of the second magnetic electrode 210 are different in polarity, the first magnetic electrode 110 and the second magnetic electrode 210 generate a mutual attraction force, so that the micro light emitting diode 200 falls into the groove a on the driving backplate 100 under the combined action of the gravity of the micro light emitting diode 200 and the attraction force generated by the first magnetic electrode 110 of the driving backplate 100 in the process of flowing along with the fluid, and meanwhile, the polarity of the lower surface of the second magnetic electrode 210 is the same, so that the cluster phenomenon generated by the mutual attraction between the second magnetic electrodes 210 can be avoided, thereby shortening the time for the micro light emitting diode 200 to fall into the groove a of the driving backplate 100, increasing the probability that the micro light emitting diode 200 reaches the groove a of the driving backplate 100, improving the transfer efficiency of the micro light emitting diode 200, and realizing a mass transfer.
S140, releasing the micro light-emitting diode into the fluid, and stirring the fluid, wherein one end of the micro light-emitting diode is provided with a second magnetic electrode, the second magnetic electrode is in contact with the first magnetic electrode, and the maximum cross-sectional dimension of the micro light-emitting diode is not less than that of the groove.
The driving back plate 100 has a plurality of grooves a on a surface thereof, a first magnetic electrode 110 is disposed at the bottom of each groove a, the cross-sectional size of the groove gradually increases from the bottom to the top, one end of the micro light emitting diode 200 is a light emitting surface, the other end thereof away from the light emitting surface is provided with a second magnetic electrode 210, the cross-sectional size of the micro light emitting diode gradually increases from the end thereof provided with the second magnetic electrode to the end thereof, and the cross-sectional size of the end thereof on the light emitting surface of the micro light emitting diode is not smaller than the maximum cross-sectional size of the groove. The sectional dimensions of the groove a and the micro light emitting diode are set to be a structure with a wide top and a narrow bottom, and the sectional dimension of one end of the light emitting surface of the micro light emitting diode is not smaller than the maximum sectional dimension of the groove, so that the directionality of the micro light emitting diode 200 falling into the groove a can be ensured, the micro light emitting diode 200 is prevented from falling into the groove a in a wrong direction, and the micro light emitting diode 200 is prevented from being inversely embedded into the groove a of the driving back plate 100.
S150, the first magnetic electrode and the second magnetic electrode generate mutual attraction acting force, and the micro light-emitting diode is embedded into the groove.
Specifically, under the action of the applied magnetic field, the surfaces of the first magnetic electrode 110 and the second magnetic electrode 210 generate different polarities, so that the first magnetic electrode 110 and the second magnetic electrode 210 are attracted to each other, and the clustering phenomenon caused by the attraction between the second magnetic electrodes 210 is avoided, so that the micro light emitting diode 200 and the groove a of the driving back plate 100 are accurately aligned.
Preferably, in the process of embedding the micro light emitting diodes into the grooves, the fluid is stirred to realize the uniform distribution of the micro light emitting diodes in the fluid, so that the micro light emitting diodes are more effectively embedded into the grooves, and the transfer efficiency is further improved.
The stirring speed of the fluid is 5-30rpm, the vertical distance of the micro light-emitting diode falling in the fluid is 3-15 cm in the process of releasing the micro light-emitting diode into the fluid, and the micro light-emitting diode can be embedded into the groove with sufficient time to adjust the position of the micro light-emitting diode falling into the groove, and the micro light-emitting diode which does not fall into the groove in the correct position can be timely adjusted in position by the arrangement mode, so that the transfer efficiency is further improved.
Further, the stirring speed of the fluid and the vertical distance of the micro-leds falling in the fluid depend on the type and concentration of the fluid, for high concentration fluid, a higher stirring speed or a smaller vertical distance of the micro-leds falling in the fluid can be selected, and for low concentration fluid, a lower stirring speed or a larger vertical distance of the micro-leds falling in the fluid can be selected to ensure the efficiency of the micro-leds embedded in the grooves.
Preferably, the fluid can be selected to be ethanol, in this case, the stirring speed is selected to be 5-10rpm, preferably 8rpm, and the vertical distance of the micro light emitting diode falling in the fluid is selected to be 10-15cm, preferably 13 cm; the fluid may also be dichloromethane, in which case the stirring speed is chosen to be 20-25rpm, preferably 23rpm, and the vertical distance of the micro-leds falling in the fluid is chosen to be 5-10cm, preferably 7 cm. Through the parameter setting, the transfer can be completed in the shortest time, namely, the optimal transfer rate is achieved, and meanwhile, the transfer success rate can be improved to be more than 99.99%.
Further, after embedding the micro light emitting diode 300 in the groove a of the driving backplane 100, the method further includes:
s160, the back plate is removed from the fluid.
After the grooves on the driving back plate 100 and the micro light emitting diodes 200 are fixed, the fluid continues to be applied with the magnetic field after the container is kept still for a preset time, so as to ensure that all the grooves a on the driving back plate 100 are fixed with the micro light emitting diodes 200.
The application of the magnetic field to the fluid is further continued, and the driving back plate 100 is taken out from the fluid, at this time, the second magnetic electrode 210 on the micro light emitting diode 200 and the first magnetic electrode 110 on the driving back plate 100 are in complete contact.
And S170, forming a micro light-emitting diode display panel based on the taken driving back plate.
And stopping applying the magnetic field to the fluid, and forming the micro light-emitting diode display panel based on the taken out driving back plate. Specifically, after the driving back plate 100 is taken out, the residual fluid on the driving back plate 100 is removed and dried in the sun, and then the driving back plate 100 may be placed in a reflow apparatus, for example, a reflow furnace, to perform reflow soldering, so as to fix the micro light emitting diodes 200 in the array in the grooves of the driving back plate 100, thereby completing the mass transfer of the micro light emitting diodes 200 and realizing the preparation of the micro light emitting diode display panel.
In the above embodiment, the first magnetic electrode is disposed at the bottom of the groove of the driving back plate, and under the action of the applied magnetic field, the first magnetic electrode and the second magnetic electrode of the micro light emitting diode generate different polarities, so that the first magnetic electrode and the second magnetic electrode can attract each other, and the cluster phenomenon generated by the attraction between the second magnetic electrodes is avoided, so that the micro light emitting diode and the groove of the driving back plate realize accurate alignment, and the micro light emitting diode can accurately fall into and be fixed on the substrate under the dual actions of its own weight and magnetic force, and the groove is configured in a structure in which the cross-sectional size is gradually increased from the bottom to the top, and the cross-sectional size of the micro light emitting diode is gradually increased from the end where the second magnetic electrode is disposed to the end where the light emitting surface is disposed, and the cross-sectional size of the end where the light emitting surface of the micro light emitting diode is not smaller than the maximum cross-sectional size of the groove, the precision that little emitting diode falls into the recess of drive backplate can be further improved, prevent that little emitting diode from falling into the recess with wrong orientation, prevent promptly that little emitting diode from falling into the recess of drive backplate in to shorten little emitting diode and fall into the time of drive backplate recess, increase little emitting diode reaches the probability of drive backplate recess, thereby improve little emitting diode's transfer efficiency, realize little emitting diode's huge transfer. In addition, the micro light-emitting diodes are transferred by adopting fluid assembly, the fluid is used as a transfer medium, the micro light-emitting diodes are not damaged, the one-time transfer amount is large, and the transfer rate is ensured.
In summary, it is easy to understand by those skilled in the art that the present application provides a micro light emitting diode display panel and a method for manufacturing the same, wherein a first magnetic electrode is disposed at the bottom of a groove of a driving back plate, under the action of a magnetic field, the first magnetic electrode and the surface of a second magnetic electrode of a micro light emitting diode generate different polarities, so that the first magnetic electrode and the second magnetic electrode can attract each other, and a cluster phenomenon generated by the attraction between the second magnetic electrodes is avoided, so that the micro light emitting diode and the groove of the driving back plate can be accurately aligned, and the micro light emitting diode can accurately fall into and be fixed on a substrate under the dual actions of its own weight and magnetic force, and the groove is configured in a structure in which the cross-sectional size is gradually increased from the bottom to the top, and the cross-sectional size of the micro light emitting diode is gradually increased from the end where the second magnetic electrode is disposed to the end of a light emitting surface, the cross-sectional dimension of the light-emitting surface end of the micro light-emitting diode is not smaller than the maximum cross-sectional dimension of the groove, the accuracy of the micro light-emitting diode falling into the groove of the driving backboard can be further improved, the micro light-emitting diode is prevented from falling into the groove in a wrong direction, namely the micro light-emitting diode is prevented from being inversely embedded into the groove of the driving backboard, the time of the micro light-emitting diode falling into the groove of the driving backboard is shortened, the probability of the micro light-emitting diode reaching the groove of the driving backboard is increased, the transfer efficiency of the micro light-emitting diode is improved, and the huge transfer of the micro light-emitting diode is realized. In addition, the micro light-emitting diodes are transferred by adopting fluid assembly, the fluid is used as a transfer medium, the micro light-emitting diodes are not damaged, the one-time transfer amount is large, and the transfer rate and the transfer efficiency are ensured.
The above description is only for the purpose of illustrating embodiments of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings of the present application or are directly or indirectly applied to other related technical fields, are also included in the scope of the present application.