Spherical vertical micro LED and manufacturing method thereof, display panel and transfer method thereof

Abstract

The present invention provides a spherical vertical micro-LED and a manufacturing method thereof, a display panel and a transfer method thereof. The spherical vertical micro-LED comprises a first semiconductor layer, a second semiconductor layer, a light-emitting layer, a first electrode, an insulating layer and a second electrode; the light-emitting layer is arranged between the first semiconductor layer and the second semiconductor layer; the first electrode covers at least a portion of the surface of the first semiconductor layer, the second electrode covers at least a portion of the surface of the second semiconductor layer, and the insulating layer covers the outside of the light-emitting layer or covers the outside of the light-emitting layer and a portion of the surface of the first semiconductor layer and the second semiconductor layer. The first semiconductor layer, the second semiconductor layer and the light-emitting layer form a spherical structure, and the first electrode, the insulating layer and the second electrode form a spherical structure covering the outer layer, thereby forming a spherical vertical micro-LED, which prevents the micro-LED from being stuck outside the loading well during the transfer process, facilitates accurate alignment with the loading well during the transfer process, and can effectively improve the transfer yield and production efficiency.

Description

Technical Field

[0001] The present invention relates to the fields of display technology and LED technology, and relates to a spherical vertical micro-LED and a manufacturing method thereof, and also relates to a display panel including the spherical vertical micro-LED and a transfer method thereof. Background Art

[0002] Micro LED is an important component of the next generation of display technology. Compared with the existing liquid crystal display, it has more ideal photoelectric efficiency, brightness and contrast, and lower power consumption. It can also be combined with flexible panels to achieve flexible display. Therefore, the industry regards Micro LED as the next generation of display technology.

[0003] In order to realize the display function, multiple Micro LEDs need to be loaded onto the backplane to form a micro LED array. In the process of forming the Micro LED array, mass transfer technology is the key. At present, mass transfer technologies mainly include electrostatic transfer, micro-printing and fluid assembly. Among them, fluid assembly is to use a brush bucket to roll on the substrate so that the Micro LED is placed in a liquid suspension, and the LED falls into the corresponding loading well on the substrate through fluid force.

[0004] However, the Micro LEDs in the prior art are all rectangular or cylindrical structures. When the Micro LED falls into the loading well on the substrate, it is difficult for the Micro LED to be accurately aligned with the loading well on the substrate due to its structure. It is easy for the Micro LED to fail to embed into the loading well, which greatly limits the transfer yield and production efficiency.

[0005] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a spherical vertical micro-LED and a manufacturing method thereof, a display panel and a transfer method thereof, in view of the above-mentioned defects of the prior art, which have the advantage of easy alignment and can effectively improve the transfer yield and production efficiency.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0008] A spherical vertical micro LED, which is used to be arranged in a loading well on a back plate to form a micro LED array, comprising:

[0009] A first semiconductor layer, a second semiconductor layer and a light emitting layer, wherein the light emitting layer is disposed between the first semiconductor layer and the second semiconductor layer;

[0010] A first electrode, an insulating layer, and a second electrode, wherein the first electrode covers at least a portion of the surface of the first semiconductor layer, the second electrode covers at least a portion of the surface of the second semiconductor layer, and the insulating layer covers the outside of the light-emitting layer or covers the outside of the light-emitting layer and a portion of the surface of the first semiconductor layer and the second semiconductor layer;

[0011] The first semiconductor layer, the second semiconductor layer and the light emitting layer form a spherical structure, and the first electrode, the insulating layer and the second electrode form a spherical surface structure.

[0012] Compared with the prior art, the beneficial effects of the present technical solution are: the first semiconductor layer, the second semiconductor layer and the light-emitting layer form a spherical structure, and the first electrode, the insulating layer and the second electrode form a spherical structure covering the outer layer, forming a spherical vertical micro-LED, which prevents the micro-LED from being stuck outside the loading well, facilitates precise alignment with the loading well during the transfer process, and can effectively improve the transfer yield and production efficiency.

[0013] Furthermore, the second electrode comprises a magnetic conductive material, and the magnetism of the second electrode is opposite to the magnetism of the magnetic metal gasket disposed in the loading well.

[0014] The beneficial effect of adopting the above scheme is: a magnetic conductive material is used as the second electrode, and a magnetic metal gasket is provided in the loading well accordingly, and the magnetism of the second electrode is opposite to that of the magnetic metal gasket. During the transfer process, the spherical vertical micro LED is adsorbed onto the loading well through the action of magnetic force, and effective contact between the second electrode and the magnetic metal gasket can be ensured.

[0015] Furthermore, the magnetic conductive material in the second electrode forms a patterned shape. Specifically, the patterned shape is a triangle, a rectangle, a circle, a cross, or a ring.

[0016] The beneficial effect of adopting the above solution is that it is easy to fix different spherical vertical micro LEDs at specific positions.

[0017] Furthermore, the surface of the second electrode is provided with an alignment protrusion for alignment;

[0018] Correspondingly, an alignment recess is provided in the loading well, and the shape of the alignment protrusion matches the shape of the alignment recess.

[0019] The beneficial effect of adopting the above solution is that the spherical vertical micro LED can be more accurately and firmly arranged on the loading well by nesting the alignment protrusion on the second electrode in the alignment recess on the loading well.

[0020] Furthermore, the cross section of the alignment protrusion is triangular, rectangular, circular, cross-shaped or ring-shaped;

[0021] Correspondingly, the cross section of the alignment recess is triangular, rectangular, circular, cross-shaped or ring-shaped.

[0022] The beneficial effect of adopting the above solution is that the alignment protrusion and the alignment depression are set to different shapes, so that different spherical vertical micro-LEDs can be embedded in different depressions respectively.

[0023] Furthermore, the spherical vertical micro-LED includes an R-type LED, a G-type LED and a B-type LED, and the diameters of the spherical structures of the R-type LED, the G-type LED and the B-type LED are different.

[0024] The beneficial effect of adopting the above solution is that by setting the diameters of the spherical structures on the R-type LED, the G-type LED and the B-type LED to be different, automatic arrangement can be achieved during the transfer process, further improving the transfer efficiency.

[0025] Furthermore, the material of the first electrode is a transparent material, and the material of the second electrode is a conductive material with high reflectivity; specifically, silver.

[0026] The beneficial effects of adopting the above solution are: using a conductive material with high reflectivity as the second electrode to improve the light extraction efficiency; using a transparent material as the first electrode to ensure that light can be emitted smoothly.

[0027] Furthermore, the material of the first semiconductor layer is n-GaN, the material of the second semiconductor layer is p-GaN, the material of the light-emitting layer is InGaN or InN, the material of the first electrode is ITO, and the material of the insulating layer is silicon dioxide.

[0028] A method for manufacturing a spherical vertical micro LED comprises the following steps:

[0029] Forming an epitaxial layer on the substrate by deposition, wherein the epitaxial layer includes a second semiconductor layer, a light emitting layer and a first semiconductor layer arranged on the substrate from top to bottom;

[0030] Etching the second semiconductor layer and part of the light-emitting layer to obtain a first chip hemisphere;

[0031] depositing a first insulating layer on the first chip hemisphere;

[0032] etching the first insulating layer to expose the second semiconductor layer;

[0033] Plating a second electrode on the second semiconductor layer;

[0034] Flip the first chip hemisphere over and cover the soft layer on the bonding substrate;

[0035] peeling off the substrate to expose the first semiconductor layer;

[0036] Etching the first semiconductor layer and part of the light-emitting layer to obtain a second chip hemisphere;

[0037] depositing a second insulating layer on the second chip hemisphere;

[0038] etching the second insulating layer to expose the first semiconductor layer;

[0039] Plating a first electrode on the first semiconductor layer;

[0040] The bonding substrate and soft layer are peeled off to obtain spherical vertical micro-LEDs.

[0041] Compared with the prior art, the beneficial effects of the present technical solution are: by means of deposition and etching, two hemispherical structures are successively formed on the first semiconductor layer, the second semiconductor layer and the light-emitting layer, and the first electrode, the insulating layer and the second electrode are obtained by electroplating, thereby forming a spherical vertical micro-LED, which prevents the micro-LED from being stuck outside the loading well, facilitates precise alignment with the loading well during the transfer process, and can effectively improve the transfer yield and production efficiency.

[0042] A spherical vertical micro LED display panel, comprising:

[0043] A back plate, wherein a plurality of loading wells are arranged on the back plate, and the plurality of loading wells form a loading well array;

[0044] A plurality of spherical vertical micro LEDs, wherein the spherical vertical micro LEDs are the spherical vertical micro LEDs described above, and the plurality of spherical vertical micro LEDs are respectively disposed in the plurality of loading wells to form a micro LED array;

[0045] A transparent connection circuit, wherein the transparent connection circuit is used to connect the first electrode of the spherical vertical micro-LED and the first port on the backplane to achieve electrical connection between the first electrode and the outside world;

[0046] A magnetic metal gasket is arranged in the loading well, and is used to connect the second electrode of the spherical vertical micro-LED and the second port on the backplane to achieve electrical connection between the second electrode and the outside world.

[0047] Compared with the prior art, the beneficial effect of this technical solution is that multiple spherical vertical micro-LEDs are respectively embedded in multiple loading wells of the back panel to form a display panel, which not only has more ideal photoelectric efficiency, brightness and contrast and lower power consumption, but also can improve transfer yield and production efficiency.

[0048] A method for transferring a spherical vertical micro LED display panel comprises the following steps:

[0049] The following steps are involved:

[0050] Placing a plurality of spherical vertical micro-LEDs in a suspension, wherein the spherical vertical micro-LEDs are the spherical vertical micro-LEDs described above;

[0051] A back plate is placed in the suspension, and the spherical vertical micro LED is floated above the back plate; wherein a plurality of loading wells are arranged on the back plate, and the plurality of loading wells form a loading well array; a magnetic metal gasket is arranged in the loading well, and the second electrode is a magnetic conductive material, and the magnetism of the second electrode is opposite to the magnetism of the magnetic metal gasket arranged in the loading well;

[0052] The spherical vertical micro-LEDs are adsorbed into the loading well by the magnetic force between the second electrode and the magnetic metal gasket to form a micro-LED array, thereby completing the transfer.

[0053] Compared with the prior art, the beneficial effects of the present technical solution are as follows: a magnetic metal gasket is provided in the loading well on the back panel, and a magnetic conductive material is used as the second electrode. The spherical vertical micro-LED is adsorbed into the loading well by utilizing the opposite magnetism of the second electrode and the magnetic metal gasket, which facilitates precise alignment with the loading well during the transfer process, and can effectively improve the transfer yield and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a structural schematic diagram of a spherical vertical micro LED of the present invention.

[0055] Figure 2 It is a structural schematic diagram of a substrate and an epitaxial layer in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0056] Figure 3 It is a schematic diagram of the structure of etching the first hemisphere in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0057] Figure 4 It is a schematic structural diagram of depositing an insulating layer on the first hemisphere in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0058] Figure 5 It is a structural schematic diagram of the first etching of the insulating layer in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0059] Figure 6 It is a structural schematic diagram of plating a second electrode in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0060] Figure 7 It is a structural schematic diagram of loading a bonding substrate in a method for manufacturing a spherical vertical micro-LED according to the present invention.

[0061] Figure 8 It is a structural schematic diagram of peeling off the substrate in a method for manufacturing a spherical vertical micro-LED according to the present invention.

[0062] Fig. 9 It is a structural schematic diagram of etching a second hemisphere in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0063] Fig.10 It is a structural schematic diagram of depositing an insulating layer on the second hemisphere in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0064] Fig.11 It is a structural schematic diagram of the second etching of the insulating layer in a method for manufacturing a spherical vertical micro-LED of the present invention.

[0065] Fig.12 It is a structural schematic diagram of plating a first electrode in a method for manufacturing a spherical vertical micro-LED according to the present invention.

[0066] Fig.13 It is a schematic diagram of a transfer method of a spherical vertical micro LED display panel of the present invention.

[0067] Fig.14 This is a first schematic diagram of a patterned shape in a spherical vertical micro-LED of the present invention.

[0068] Fig.15 This is a second schematic diagram of a patterned shape in a spherical vertical micro-LED of the present invention.

[0069] Fig.16 This is a third schematic diagram of a patterned shape in a spherical vertical micro-LED of the present invention.

[0070] In the figure, the components represented by the reference numerals are as follows:

[0071] A first semiconductor layer 1, a second semiconductor layer 2, a light emitting layer 3, a first electrode 4, an insulating layer 5, a second electrode 6, and a patterned shape 7;

[0072] Back plate 101 , substrate 102 , bonding substrate 103 , soft layer 104 , first chip hemisphere 105 , and second chip hemisphere 106 . DETAILED DESCRIPTION

[0073] In order to make the purpose, technical solution and advantages of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0074] In the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0075] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two components. When a component is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other component or there can also be a central component. When a component is considered to be "connected" to another element, it can be directly connected to the other element or there can be a central element at the same time. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] Mass transfer is the process of transferring a large number of tiny-sized Micro LEDs to a substrate to form a micro LED array, and then to form an LED display panel. Traditional LED chips are usually rectangular or cylindrical structures. During the transfer process, due to their shape, Micro LEDs will be stuck outside the loading well, making it difficult to accurately align with the loading well on the substrate. It is easy for Micro LEDs to fail to fit into the loading well, greatly limiting the transfer yield and production efficiency. In response to the above problems, the present invention provides spherical vertical micro LEDs and their manufacturing methods, display panels and their transfer methods, so as to simplify the mass transfer process and make the transfer efficiency far exceed that of traditional solutions. The following is combined with Figure 1-Figure 13 The technical solution of the present invention is described in detail.

[0077] like Figure 1As shown, a spherical vertical micro-LED is used to be arranged in a loading well on a back plate 101 to form a micro-LED array. The spherical vertical micro-LED includes a first semiconductor layer 1, a second semiconductor layer 2, a light-emitting layer 3, a first electrode 4, an insulating layer 5, and a second electrode 6. The working principle of the spherical vertical micro-LED is as follows: the insulating layer 5 separates the first electrode 4 and the second electrode 6, and the first semiconductor layer 1 and the second semiconductor layer 2 are electrically connected to the outside through the first electrode 4 and the second electrode 6, respectively. Electrons and holes are injected from the first electrode 4 and the second electrode 6 into the first semiconductor layer 1 and the second semiconductor layer 2, respectively, and then recombine in the light-emitting layer 3 between the first semiconductor layer 1 and the second semiconductor layer 2, and release energy in the form of photons, thereby achieving light emission.

[0078] The innovation of the present invention is that the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3 form a spherical structure, and the first electrode 4, the insulating layer 5 and the second electrode 6 form a spherical structure. The first electrode 4, the insulating layer 5 and the second electrode 6 form a spherical structure to wrap the spherical structure formed by the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3, forming a vertical micro-LED that is spherical as a whole. Specifically, the light-emitting layer 3 is arranged between the first semiconductor layer 1 and the second semiconductor layer 2; the first electrode 4 covers at least part of the surface of the first semiconductor layer 1, the second electrode 6 covers at least part of the surface of the second semiconductor layer 2, and the insulating layer 5 covers the outside of the light-emitting layer 3 or covers the outside of the light-emitting layer 3 and part of the surface of the first semiconductor layer 1 and the second semiconductor layer 2.

[0079] The function of the insulating layer 5 is to separate the first semiconductor layer 1 from the second semiconductor layer 2. When manufacturing a spherical vertical micro-LED, the first electrode 4 can completely cover the outside of the first semiconductor layer 1, the second electrode 6 can completely cover the outside of the second semiconductor layer 2, and the insulating layer 5 can only cover the outside of the light-emitting layer 3. Figure 1 As shown, the first electrode 4 covers part of the first semiconductor layer 1, the second electrode 6 covers part of the second semiconductor layer 2, and the insulating layer 5 covers part of the first semiconductor layer 1 and the second semiconductor layer 2 in addition to the light-emitting layer 3. In short, the function of the insulating layer is to separate the first electrode from the second electrode. Therefore, from a structural point of view, the insulating layer can be only arranged on the corresponding outer side of the light-emitting layer, and in addition, it can be further extended on this basis to cover the first semiconductor layer and the second semiconductor layer.

[0080] Through the above technical scheme, the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3 form a spherical structure, and the first electrode 4, the insulating layer 5 and the second electrode 6 form a spherical structure covering the outer layer. After the spherical vertical micro-LED is formed by the spherical structure and the spherical structure, it is only necessary to set a plurality of hemispherical loading wells on the back plate 101 to effectively avoid the micro-LED being stuck outside the loading well, so as to conveniently, quickly and efficiently transfer the spherical vertical micro-LED to the back plate 101, realize precise alignment, and effectively improve the transfer yield and production efficiency.

[0081] The present invention also creatively utilizes magnetic force to improve the transfer efficiency of spherical vertical micro-LEDs: preferably, the second electrode 6 is a magnetic conductive material, and the magnetism of the second electrode 6 is opposite to the magnetism of the magnetic metal gasket arranged in the loading well.

[0082] A magnetic conductive material is used as the second electrode 6, and a magnetic metal gasket is arranged in the loading well, and the magnetic properties of the second electrode 6 are opposite to those of the magnetic metal gasket, and an interactive magnetic force is generated between the magnetic metal gasket and the second electrode 6. The magnetic metal gasket is fixed in the loading well, and the magnetic metal gasket adsorbs the second electrode 6 of the spherical vertical micro-LED through magnetic force, thereby adsorbing the spherical vertical micro-LED to the loading well. In addition, the magnetic metal gasket also has an electrical connection function. The above technical solution can not only improve the transfer efficiency of the spherical vertical micro-LED, but also ensure the effective contact between the second electrode 6 and the magnetic metal gasket.

[0083] Preferably, the magnetic conductive material in the second electrode forms a patterned shape 7; Fig.14 , Fig.15 and Fig.16 As shown, the patterned shape 7 is a triangle or a rectangle or a circle or a cross or a ring. Correspondingly, the magnetic metal gasket is set to a patterned shape 7; the patterned shape 7 is also a triangle or a rectangle or a circle or a cross or a ring. Simply put, a part of the second electrode is magnetic and the other part is not magnetic. From the outside, the surface of the sphere formed by the magnetic part can be various shapes, such as a triangle, a square, a circle, etc. This magnetic part with a patterned painting is also conducive to alignment. It should be noted that the patterned shape referred to here refers to the projection shape formed on the spherical surface.

[0084] The above technical solution can facilitate fixing different spherical vertical micro-LEDs in specific positions. For example, the patterned shapes of the magnetic metal gasket are set to triangles and circles, and the corresponding spherical vertical micro-LEDs with triangular and circular magnetic conductive materials are produced. During transfer, first put in the spherical vertical micro-LED with triangular magnetic conductive material, and most of this part of the spherical vertical micro-LED will be adsorbed and fixed by the triangular magnetic metal gasket; even if a small amount is adsorbed by the circular magnetic metal gasket, since the shape of this part does not match, the magnetic force generated is not very strong, and it only needs to be shaken lightly to make it fall off; similarly, put in the spherical vertical micro-LED with circular magnetic conductive material, and this part of the spherical vertical micro-LED will be adsorbed and fixed by the circular magnetic metal gasket. In this way, convenient transfer is achieved.

[0085] Preferably, the surface of the second electrode 6 is provided with a positioning protrusion for positioning; correspondingly, the loading well is provided with a positioning recess, that is, the loading well is further formed with a positioning recess by recessing, and the shape of the positioning protrusion matches the shape of the positioning recess. Specifically, the cross section of the positioning protrusion can be set to be a triangle, a rectangle, a circle, a cross or a ring; correspondingly, the cross section of the positioning recess is a triangle, a rectangle, a circle, a cross or a ring.

[0086] As is known to all, the three optical primary colors include red, green and blue. After the three optical primary colors are mixed, they can form all the colors required for display, thereby displaying the corresponding effects on the display screen. Based on this, the spherical vertical micro-LED in the present invention includes R-type LED, G-type LED and B-type LED, wherein the R-type LED emits red light, the G-type LED emits green light, and the B-type LED emits blue light. In the process of using spherical vertical micro-LEDs to make display panels, it is necessary to arrange the R-type LED, G-type LED and B-type LED into a specific pattern to achieve the display function. In the prior art, it is difficult to arrange the R-type LED, G-type LED and B-type LED in a specific position because the volume of the LED chip is too small and the number is too large. The present invention can solve this problem by aligning the shape and external contour of the protruding portion and the recessed portion.

[0087] The shapes of the alignment protrusions on the R-type LED, the G-type LED, and the B-type LED are different. For example, the cross-section of the alignment protrusion of the R-type LED is set to a rectangle, the cross-section of the alignment protrusion of the G-type LED is set to a circle, and the cross-section of the alignment protrusion of the B-type LED is set to a triangle; correspondingly, the cross-sections of some loading wells are set to rectangles, circles, and triangles according to a predetermined pattern. During transfer, the magnetic metal gaskets on all loading wells will generate magnetic force on the second electrodes 6 on all spherical vertical micro-LEDs. However, when the shapes of the alignment protrusions and the alignment recesses do not match, this adsorption force will be smaller, and the incorrectly matched light-emitting diodes can be separated from the backplane 101 and re-adsorbed by vibration until all are correctly matched, thereby achieving the effect of improving yield and production efficiency.

[0088] Generally, LED chips can be divided into upright chips, flip chips and vertical chips. The micro-LED involved in the present invention belongs to vertical chips. Structurally, the light-emitting layer of the vertical chip is located between the first semiconductor layer and the second semiconductor layer. When working, the light-emitting layer emits photons in all directions. When the emitted photons point to the first semiconductor layer, the photons will pass through the first semiconductor layer and the first electrode and directly emit to the outside world; when the emitted photons point to the second semiconductor layer, the photons need to change direction after passing through the second semiconductor layer and the second electrode, and then be emitted to the outside world through the first semiconductor layer and the first electrode. In this regard, the material of the first electrode is a transparent material, and the material of the second electrode is a conductive material with high reflectivity. A conductive material with high reflectivity is used as the second electrode to improve the light extraction efficiency; a transparent material is used as the first electrode to ensure that the light can be emitted smoothly.

[0089] Specifically, the material of the first semiconductor layer 1 is n-GaN, the material of the second semiconductor layer 2 is p-GaN, the material of the light-emitting layer 3 is InGaN or InN, the material of the first electrode 4 is ITO, and the material of the insulating layer 5 is silicon dioxide. In addition, the following implementations can also be adopted: the material of the first semiconductor layer includes one of N-type gallium arsenide and N-type copper phosphide, and the material of the second semiconductor layer includes one of P-type gallium arsenide and P-type copper phosphide; the material of the light-emitting layer is one or more of indium gallium aluminum nitride, gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, indium arsenic phosphide or indium gallium arsenide; the material of the first electrode includes one or any combination of titanium, aluminum, nickel and their alloys. It should be noted that the above materials are only one of the implementations, and do not limit the materials of the first semiconductor layer 1, the second semiconductor layer 2, the light-emitting layer 3, the first electrode 4 and the insulating layer 5. Other materials that achieve the same function based on the same principle should also be one of the embodiments of the present invention, and are not exhaustively listed here.

[0090] Correspondingly, the present invention also provides a method for manufacturing a spherical vertical micro-LED, which specifically includes the following steps:

[0091] An epitaxial layer is formed on the substrate 102 by deposition, wherein the epitaxial layer includes a second semiconductor layer 2, a light emitting layer 3 and a first semiconductor layer 1 which are arranged on the substrate 102 from top to bottom;

[0092] Etching the second semiconductor layer 2 and part of the light emitting layer 3 to obtain a first chip hemisphere 105;

[0093] Depositing a first insulating layer on the first chip hemisphere 105 to cover the first chip hemisphere 105;

[0094] Etching the first insulating layer to expose the second semiconductor layer 2;

[0095] A second electrode 6 is plated on the second semiconductor layer 2; preferably, a magnetic conductive material is used as the second semiconductor layer 2;

[0096] Turn the first chip hemisphere 105 over and cover the soft layer 104 on the bonding substrate 103;

[0097] The substrate 102 is peeled off to expose the first semiconductor layer 1;

[0098] Etching the first semiconductor layer 1 and part of the light emitting layer 3 to obtain a second chip hemisphere 106;

[0099] Depositing a second insulating layer on the second chip hemisphere 106 so that the second insulating layer covers the second chip hemisphere 106 ;

[0100] Etching the second insulating layer to expose the first semiconductor layer 1;

[0101] Plating a first electrode 4 on the first semiconductor layer 1;

[0102] The bonding substrate 103 and the soft layer 104 are peeled off to obtain a spherical vertical micro-LED.

[0103] Combine the following Figure 2-Figure 12 , the above method is explained according to the process of production process.

[0104] like Figure 2 As shown, an epitaxial layer is first formed on the substrate 102 , and the epitaxial layer includes a first semiconductor layer 1 , a second semiconductor layer 2 and a light emitting layer 3 ; wherein the light emitting layer 3 is located between the first semiconductor layer 1 and the second semiconductor layer 2 .

[0105] like Figure 3As shown, the epitaxial layer is etched out into a first chip hemisphere 105 by a dry etching process. The first chip hemisphere 105 is specifically a hemispherical structure left by etching away a part of the second semiconductor layer and the light emitting layer.

[0106] like Figure 4 As shown, a first insulating layer is obtained by deposition on the second semiconductor layer 2 and the light-emitting layer 3, and the first insulating layer covers the second semiconductor layer and the light-emitting layer.

[0107] like Figure 5 As shown, the first insulating layer covering the upper portion of the first chip hemisphere 105 is etched away to expose the second semiconductor layer on the first chip hemisphere 105, leaving only a small portion of the first insulating layer at the junction of the second semiconductor layer and the light emitting layer for insulation.

[0108] like Figure 6 As shown, after the second semiconductor layer is exposed on the first chip hemisphere 105, a second electrode 6 is further plated on the second semiconductor layer. Preferably, the second electrode 6 is a magnetic conductive material to prepare for mass transfer. The magnetic properties of the second electrode 6 are opposite to those of the magnetic metal pad disposed in the loading well.

[0109] like Figure 7 As shown, after the second electrode 6 is plated, the first chip hemisphere 105 is turned upside down and covered on the bonding substrate 103. The bonding substrate 103 is provided with a soft layer 104, so the turned first chip hemisphere 105 is equivalent to covering the soft layer 104 on the bonding substrate 103. After completing this step, the first chip hemisphere 105 changes from facing up to facing down.

[0110] like Figure 8 As shown, the substrate 102 at the top layer is peeled off to expose the first semiconductor layer 1. On the semi-finished spherical vertical micro LED, the structure from top to bottom is the first semiconductor layer 1, the light-emitting layer 3 and the second semiconductor layer 2, and the second semiconductor layer 2 is covered with a second electrode 6.

[0111] like Fig. 9 As shown, after the substrate 102 is peeled off to expose the first semiconductor layer 1, the second chip hemisphere 106 is etched out by a dry etching process, and the second chip hemisphere 106 is specifically a hemispherical structure left by etching away part of the first semiconductor layer 1 and the light-emitting layer 3. At this time, the second chip hemisphere 106 and the first chip hemisphere 105 form a complete spherical structure, and this complete spherical structure is a spherical structure formed by the first semiconductor layer, the second semiconductor layer and the light-emitting layer 3.

[0112] like Fig.10As shown, a second insulating layer is obtained by deposition on the first semiconductor layer 1 and the light-emitting layer 3 , and the second insulating layer covers the first semiconductor layer and the light-emitting layer.

[0113] like Fig.11 As shown, the second insulating layer covering the upper part of the second chip hemisphere 106 is etched away to expose the first semiconductor layer on the second chip hemisphere 106, leaving only a small portion of the second insulating layer at the junction of the first semiconductor layer and the light-emitting layer to play an insulating role. The remaining first insulating layer and the second insulating layer are combined into an insulating layer 5 of a complete structure to isolate the first semiconductor layer from the second semiconductor layer.

[0114] like Fig.12 As shown, after the first semiconductor layer 1 is exposed on the second chip hemisphere 106, the first electrode 4 is further plated on the first semiconductor layer 1. Preferably, the second electrode 6 is a transparent material to facilitate the emission of light. At this time, the first electrode 4, the insulating layer 5 and the second electrode 6 form a spherical structure, and the spherical structure wraps the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3 into a spherical structure, thereby obtaining a spherical vertical micro LED.

[0115] In general, two hemispherical structures are formed successively on the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3 by deposition and etching, and the first electrode 4, the insulating layer 5 and the second electrode 6 are obtained by electroplating, thereby forming a spherical vertical micro-LED, which prevents the micro-LED from being stuck outside the loading well and facilitates precise alignment with the loading well during the transfer process, which can effectively improve the transfer yield and production efficiency.

[0116] Correspondingly, the present invention also provides a spherical vertical micro LED display panel, the main structure of which includes a back plate 101. In particular, the spherical vertical micro LED is mounted on the back plate 101 to form a spherical vertical micro LED display panel.

[0117] Specifically, a plurality of loading wells matching the size of the spherical vertical micro-LEDs are provided on the back plate 101, and a magnetic metal gasket matching the second electrode 6 is provided in the loading wells. When a plurality of spherical vertical micro-LEDs are fixed to the loading wells on the back plate 101, a micro-LED array can be formed. A transparent transparent connection circuit is plated on the first electrode 4, and the transparent connection circuit is used to connect the first electrode 4 of the spherical vertical micro-LED and the first port on the back plate 101 to realize the electrical connection between the first electrode 4 and the outside world. In addition, the second electrode 6 is connected to the second port on the back plate 101 through the magnetic metal gasket to realize the electrical connection between the second electrode 6 and the outside world.

[0118] Preferably, the magnetism of the second electrode 6 is opposite to that of the magnetic metal gasket disposed in the loading well, so that the spherical vertical micro LED can be adsorbed to the loading well by magnetic force during the transfer process, and effective contact between the second electrode 6 and the magnetic metal gasket can be ensured.

[0119] Preferably, the surface of the second electrode 6 is provided with a positioning protrusion for positioning; correspondingly, the loading well is provided with a positioning recess, and the shape of the positioning protrusion matches the shape of the positioning recess. In addition, the cross section of the positioning protrusion is triangular, rectangular, circular, cross-shaped or annular; correspondingly, the cross section of the positioning recess is triangular, rectangular, circular, cross-shaped or annular.

[0120] Preferably, the spherical vertical micro-LEDs include an R-type LED, a G-type LED and a B-type LED, and the diameters of the spherical structures of the R-type LED, the G-type LED and the B-type LED are different.

[0121] Correspondingly, the present invention also provides a method for transferring a spherical vertical micro LED display panel, comprising the following steps:

[0122] like Fig.13 As shown, first, a plurality of spherical vertical micro-LEDs are placed in a suspension, wherein the spherical vertical micro-LEDs are the spherical vertical micro-LEDs described above;

[0123] Secondly, a back plate 101 is placed in the suspension, and the spherical vertical micro LED is floated above the back plate 101; wherein a plurality of loading wells are arranged on the back plate 101, and the plurality of loading wells form a loading well array; a magnetic metal gasket is arranged in the loading well, and the second electrode 6 is a magnetic conductive material, and the magnetism of the second electrode 6 is opposite to the magnetism of the magnetic metal gasket arranged in the loading well.

[0124] Again, the spherical vertical micro-LEDs are adsorbed into the loading well by the magnetic force between the second electrode 6 and the magnetic metal gasket to form a micro-LED array, thus completing the transfer.

[0125] It should be noted that the above is only the process of transferring the spherical vertical micro LED to the backplane, and does not include the packaging process. Further packaging is required to form a complete spherical vertical micro LED display panel.

[0126] A large number of spherical vertical micro LEDs are placed in the suspension, and a magnetic metal gasket is provided on the back plate 101. The magnetic metal gasket has a magnetic property opposite to that of the second electrode 6. The spherical vertical micro LEDs are adsorbed into the loading well by the action of magnetic force, so that the spherical vertical micro LEDs are accurately aligned in the loading well of the back plate 101. There are two ways to implement the magnetic metal gasket. One is to use magnetic materials as magnetic metal gaskets, and there is direct magnetic force; the other is to use electromagnetic induction to generate magnetic force after power is turned on. When the suspension flows, the second electrode 6 and the second metal pad are adsorbed to each other by the adsorption of the magnetic electrode.

[0127] The spherical vertical micro-LED includes an R-type LED, a G-type LED and a B-type LED. The surface of the second electrode is provided with an alignment protrusion for alignment; correspondingly, an alignment recess is provided in the loading well, and the shape of the alignment protrusion matches the shape of the alignment recess. The shapes or sizes of the alignment protrusions on the R-type LED, the G-type LED and the B-type LED are different. For example, the cross section of the alignment protrusion of the R-type LED is set to a rectangle, the cross section of the alignment protrusion of the G-type LED is set to a circle, and the cross section of the alignment protrusion of the B-type LED is set to a triangle; correspondingly, according to a predetermined pattern, the cross section of some loading wells is set to a rectangle, a circle and a triangle. During transfer, the magnetic metal gaskets on all loading wells will generate magnetic force on the second electrodes on all spherical vertical micro-LEDs. However, when the shapes of the alignment protrusion and the recess do not match, the adsorption force will be small, and the light-emitting diodes with incorrect matching can be separated from the backplane and re-adsorbed by vibration until all are correctly matched, thereby achieving the effect of improving yield and production efficiency.

[0128] In addition to differentiating different spherical vertical micro-LEDs by setting the alignment protrusions and alignment depressions to different shapes, different spherical vertical micro-LEDs can also be distinguished by setting their spherical structures to different sizes. For example, the R-type LED is set to a spherical structure with a radius of R1, the G-type LED is set to a spherical structure with a radius of R2, and the B-type LED is set to a spherical structure with a radius of R3; correspondingly, according to a predetermined pattern, some loading wells are set to circles with cross-sectional radii of R1, R2, and R3. In this way, the yield rate and production efficiency can also be improved.

[0129] Assuming R1>R2>R3, when using suspension transfer assembly, the three different colors of LEDs, R-type LED, G-type LED, and B-type LED, are of different sizes and can be transferred from large to small. For example, the largest R-type LED is transferred first. The R-type LED will only be stably adsorbed and fixed in the loading well of size R1. At this time, even if a small number of R-type LEDs are adsorbed in the loading well of size R2 or R2, since the size of this part does not match, the magnetic force generated is not very strong, and it only needs to be gently shaken to make it fall off. The same principle can be used to transfer G-type LED and B-type LED in turn, thereby greatly improving the transfer efficiency.

[0130] In summary, the present invention provides a spherical vertical micro-LED and a manufacturing method thereof, a display panel and a transfer method thereof. By means of deposition and etching, two hemispherical structures are successively formed on the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3, and the first electrode 4, the insulating layer 5 and the second electrode 6 are obtained by electroplating, thereby forming a spherical vertical micro-LED to prevent the micro-LED from being stuck outside the loading well, facilitate precise alignment with the loading well during the transfer process, and effectively improve the transfer yield and production efficiency.

[0131] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A spherical vertical micro LED, characterized in that: include: A first chip hemisphere, wherein the first chip hemisphere includes a light emitting layer and a second semiconductor layer disposed on the light emitting layer; A second electrode, the second electrode is disposed in the middle of the second semiconductor layer, and the second electrode portion has magnetic properties; a first insulating layer, the first insulating layer being provided on both sides except a middle portion of the second semiconductor layer; a second chip hemisphere, wherein the second chip hemisphere and the first chip hemisphere share the light-emitting layer; the second chip hemisphere comprises a first semiconductor layer disposed under the light-emitting layer; a first electrode, the first electrode being disposed in the middle of the first semiconductor layer; a second insulating layer, the second insulating layer being provided on both sides except a middle portion of the first semiconductor layer; The second chip hemisphere and the first chip hemisphere form a spherical structure, and the first electrode, the first insulating layer, the second insulating layer and the second electrode form a spherical surface structure of the spherical structure.

2. The spherical vertical micro LED according to claim 1, characterized in that: The second electrode includes a magnetic conductive material, and the magnetic properties of the second electrode are opposite to the magnetic properties of the magnetic metal pad disposed in the loading well.

3. The spherical vertical micro-LED according to claim 2, characterized in that: The magnetic conductive material in the second electrode forms a patterned shape.

4. The spherical vertical micro LED according to claim 3, characterized in that: The patterned shape is a triangle, a rectangle, a circle, a cross or a ring.

5. The spherical vertical micro LED according to claim 3, characterized in that: The spherical vertical micro-LEDs include an R-type LED, a G-type LED, and a B-type LED, and the diameters of the spherical structures on the R-type LED, the G-type LED, and the B-type LED are different.

6. The spherical vertical micro-LED according to claim 1, characterized in that: The first electrode is made of a transparent material, and the second electrode is made of a conductive material with high reflectivity.

7. The spherical vertical micro-LED according to claim 1, characterized in that: The material of the first semiconductor layer is n-GaN, the material of the second semiconductor layer is p-GaN, the material of the light-emitting layer is InGaN or InN, the material of the first electrode is ITO, and the material of the insulating layer is silicon dioxide.

8. A method for manufacturing a spherical vertical micro LED, characterized in that: The following steps are involved: Forming an epitaxial layer on the substrate by deposition, wherein the epitaxial layer includes a second semiconductor layer, a light emitting layer and a first semiconductor layer arranged on the substrate from top to bottom; Etching the second semiconductor layer and part of the light-emitting layer to obtain a first chip hemisphere; depositing a first insulating layer on the first chip hemisphere; etching the first insulating layer to expose the second semiconductor layer; Plating a second electrode on the second semiconductor layer; Flip the first chip hemisphere over and cover the soft layer on the bonding substrate; peeling off the substrate to expose the first semiconductor layer; Etching the first semiconductor layer and part of the light-emitting layer to obtain a second chip hemisphere; depositing a second insulating layer on the second chip hemisphere; etching the second insulating layer to expose the first semiconductor layer; Plating a first electrode on the first semiconductor layer; The bonding substrate and soft layer are peeled off to obtain spherical vertical micro-LEDs.

9. A micro LED display panel, characterized in that: include: A back plate, wherein a plurality of loading wells are arranged on the back plate, and the plurality of loading wells form a loading well array; A plurality of spherical vertical micro LEDs, wherein the spherical vertical micro LEDs are manufactured by the manufacturing method of the spherical vertical micro LEDs according to claim 8, and the plurality of the spherical vertical micro LEDs are respectively arranged in the plurality of the loading wells to form a micro LED array; A transparent connection circuit, wherein the transparent connection circuit is used to connect the first electrode of the spherical vertical micro-LED and the first port on the backplane to achieve electrical connection between the first electrode and the outside world; A magnetic metal gasket is arranged in the loading well, and is used to connect the second electrode of the spherical vertical micro-LED and the second port on the backplane to achieve electrical connection between the second electrode and the outside world.

10. A method for transferring a micro LED display panel, characterized in that: The following steps are involved: placing a plurality of spherical vertical micro-LEDs in a suspension, wherein the spherical vertical micro-LEDs are manufactured by the method for manufacturing spherical vertical micro-LEDs as claimed in claim 8; A back plate is placed in the suspension, and the spherical vertical micro LED is floated above the back plate; wherein a plurality of loading wells are arranged on the back plate, and the plurality of loading wells form a loading well array; a magnetic metal gasket is arranged in the loading well, and the second electrode comprises a magnetic conductive material, and the magnetism of the second electrode is opposite to the magnetism of the magnetic metal gasket arranged in the loading well; The spherical vertical micro-LEDs are adsorbed into the loading well by the magnetic force between the second electrode and the magnetic metal gasket to form a micro-LED array, thereby completing the transfer.

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