CN211350681U

CN211350681U - Spherical vertical micro LED and display panel thereof

Info

Publication number: CN211350681U
Application number: CN202020382543.5U
Authority: CN
Inventors: 唐彪; 许时渊; 刘海平
Original assignee: Chongqing Kangjia Photoelectric Technology Research Institute Co Ltd
Current assignee: Chongqing Kangjia Optoelectronic Technology Co ltd
Priority date: 2020-03-23
Filing date: 2020-03-23
Publication date: 2020-08-25
Anticipated expiration: 2030-03-23

Abstract

The utility model provides a spherical vertical micro LED and a display panel thereof, wherein the spherical vertical micro LED comprises a first semiconductor layer, a second semiconductor layer, a luminescent 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 part of the surface of the first semiconductor layer, the second electrode covers at least part of the surface of the second semiconductor layer, and the insulating layer covers outside the light-emitting layer or covers outside the light-emitting layer and part of the surfaces 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, the first electrode, the insulating layer and the second electrode form a spherical structure covering the outer layer, and further form a spherical vertical micro LED, so that the micro LED is prevented from being clamped outside the loading well in the transfer process, the micro LED is convenient to align with the loading well accurately in the transfer process, and the transfer yield and the production efficiency can be effectively improved.

Description

Spherical vertical micro LED and display panel thereof

Technical Field

The utility model relates to a show technical field and LED technical field, relate to a spherical perpendicular miniature LED, relate to a display panel including above-mentioned spherical perpendicular miniature LED simultaneously.

Background

The Micro LED is an important component of a new generation display technology, has more ideal photoelectric efficiency, brightness and contrast and lower power consumption compared with the existing liquid crystal display, and can realize flexible display by combining a flexible panel. Therefore, Micro LEDs are considered as the next generation display technology in the industry.

In order to realize the display function, a plurality of Micro LEDs are loaded on the back plate to form a Micro LED array. Bulk transfer techniques are critical in forming Micro LED arrays. The current bulk transfer techniques mainly include electrostatic transfer, micro-printing, and fluid assembly. The fluid assembly is to roll on the substrate by using a brush barrel, so that the Micro LED is placed in the liquid suspension, and the LED falls into a corresponding loading well on the substrate through the fluid force.

However, the Micro LEDs in the prior art are all in a cuboid or cylindrical structure, and are limited in structure in the process of falling into the loading well on the substrate, so that the Micro LEDs are difficult to align with the loading well on the substrate accurately, the problem that the Micro LEDs cannot be embedded into the loading well easily occurs, and the transfer yield and the production efficiency are greatly limited.

Accordingly, the prior art is yet to be improved and developed.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to prior art's above-mentioned defect, provide spherical perpendicular miniature LED and display panel, have the advantage of being convenient for counterpoint, can effectively improve transfer yield and production efficiency.

The utility model provides a technical scheme that technical problem adopted as follows:

a spherical vertical micro LED for forming an array of micro LEDs in a loading well disposed on a backplane, comprising:

the light emitting diode comprises a first semiconductor layer, a second semiconductor layer and a light emitting layer, wherein the light emitting layer is arranged between the first semiconductor layer and the second semiconductor layer;

the light-emitting diode comprises a first electrode, an insulating layer and a second electrode, wherein the first electrode covers at least part of the surface of a first semiconductor layer, the second electrode covers at least part of the surface of a 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 part of the surfaces 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.

Compared with the prior art, the technical scheme has the beneficial effects that: the first semiconductor layer, the second semiconductor layer and the light-emitting layer form a spherical structure, the first electrode, the insulating layer and the second electrode form a spherical structure covering the outer layer, spherical vertical micro LEDs are formed, the micro LEDs are prevented from being clamped outside the loading trap, accurate alignment between the micro LEDs and the loading trap in the transferring process is facilitated, and the transferring yield and the production efficiency can be effectively improved.

Further, the second electrode comprises a magnetic conductive material, and the magnetism of the second electrode is opposite to that of the magnetic metal gasket arranged in the loading well.

The beneficial effect who adopts above-mentioned scheme is: the magnetic conductive material is adopted as the second electrode, the magnetic metal gasket is correspondingly arranged in the loading trap, the magnetism of the second electrode is opposite to that of the magnetic metal gasket, the spherical vertical micro LED is adsorbed on the loading trap through the magnetic force effect in the transferring process, and the effective contact of the second electrode and the magnetic metal gasket can be guaranteed.

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

The beneficial effect who adopts above-mentioned scheme is: it is convenient to fix different spherical vertical micro-LEDs at specific positions.

Furthermore, the surface of the second electrode is provided with a contraposition bulge part for contraposition;

correspondingly, a contraposition depressed part is arranged in the loading trap, and the shape of the contraposition raised part is matched with that of the contraposition depressed part.

The beneficial effect who adopts above-mentioned scheme is: the alignment convex part on the second electrode is nested in the alignment concave part on the loading trap, so that the spherical vertical micro LED can be more accurately and firmly arranged on the loading trap.

Further, the cross section of the alignment convex part is triangular, rectangular, circular, cross-shaped or annular;

correspondingly, the cross section of the alignment recess is triangular or rectangular or circular or cross-shaped or annular.

The beneficial effect who adopts above-mentioned scheme is: the alignment convex part and the alignment concave part are set to be different shapes, so that different spherical vertical micro LEDs can be conveniently embedded into different concave parts respectively.

Further, the spherical vertical micro LED comprises 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.

The beneficial effect who adopts above-mentioned scheme is: the diameters of the spherical structures of the R-type LED, the G-type LED and the B-type LED are set to be different, so that automatic arrangement in a transfer process can be realized, and the transfer efficiency is further improved.

Furthermore, the first electrode is made of a transparent material, and the second electrode is made of a high-reflectivity conductive material; in particular silver.

The beneficial effect who adopts above-mentioned scheme is: a high-reflectivity conductive material is adopted as the second electrode, so that the light extraction efficiency is improved; and a transparent material is adopted as the first electrode, so that smooth light emergence is ensured.

Further, the first semiconductor layer is made of n-GaN, the second semiconductor layer is made of p-GaN, the light emitting layer is made of InGaN or InN, the first electrode is made of ITO, and the insulating layer is made of silicon dioxide.

A spherical vertical micro LED display panel comprising:

the device comprises a back plate, a plurality of loading wells and a plurality of loading wells, wherein the loading wells form a loading well array;

the spherical vertical micro LEDs are the spherical vertical micro LEDs, and are respectively arranged in the loading wells to form a micro LED array;

the transparent connecting circuit is used for connecting a first electrode of the spherical vertical micro LED and a first port on the back plate to realize the electric connection of the first electrode and the outside;

the magnetic metal gasket is arranged in the loading trap and used for connecting a second electrode of the spherical vertical micro LED and a second port on the back plate to realize the electric connection of the second electrode and the outside.

Compared with the prior art, the technical scheme has the beneficial effects that: the spherical vertical micro LEDs are respectively embedded into the loading wells of the back plate, so that the display panel is formed, more ideal photoelectric efficiency, brightness, contrast and lower power consumption are achieved, and transfer yield and production efficiency can be improved.

Drawings

Fig. 1 is a schematic structural view of a spherical vertical micro LED of the present invention.

Fig. 2 is a schematic structural view of the substrate and the epitaxial layer in the spherical vertical micro LED of the present invention.

Fig. 3 is a schematic structural diagram of the first hemisphere etched in the spherical vertical micro LED of the present invention.

Fig. 4 is a schematic structural diagram of the insulating layer deposited on the first hemisphere in the spherical vertical micro LED of the present invention.

Fig. 5 is a schematic structural view of the first etching of the insulating layer in the spherical vertical micro LED of the present invention.

Fig. 6 is a schematic structural view of the spherical vertical micro LED of the present invention with the second electrode plated thereon.

Fig. 7 is a schematic structural diagram of a mounting substrate in a spherical vertical micro LED.

Fig. 8 is a schematic structural view of the substrate for peeling off in the spherical vertical micro LED of the present invention.

Fig. 9 is a schematic structural view of a spherical vertical micro LED according to the present invention, in which a second hemisphere is etched.

Fig. 10 is a schematic diagram of a spherical vertical micro LED according to the present invention, wherein an insulating layer is deposited on a second hemisphere.

Fig. 11 is a schematic structural view of the second etching of the insulating layer in the spherical vertical micro LED of the present invention.

Fig. 12 is a schematic structural view of the first electrode plated in the spherical vertical micro LED of the present invention.

Fig. 13 is a schematic diagram of the transferring process of the spherical vertical micro LED display panel of the present invention.

Fig. 14 is a first schematic diagram of a patterned shape in a spherical vertical micro LED of the present invention.

Fig. 15 is a second schematic diagram of the patterned shapes in a spherical vertical micro LED of the present invention.

Fig. 16 is a third schematic view of the patterned shapes in a spherical vertical micro LED according to the present invention.

In the figures, the list of components represented by the various reference numbers is as follows:

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;

the chip comprises a back plate 101, a substrate 102, a bonding substrate 103, a soft layer 104, a first chip hemisphere 105 and a second chip hemisphere 106.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and clearer, the present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or assembly referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. When an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The specific meaning of the above terms in the present invention can be understood in specific cases for those skilled in the art.

And (3) huge transfer, namely, transferring a large number of Micro LEDs with Micro sizes onto a substrate to form a Micro LED array, thereby forming the process of an LED display panel. Traditional LED chip is cuboid or cylinder structure usually, in the transfer process, is subject to its shape, and Micro LED can block outside loading the trap, is difficult to with the accurate counterpoint of loading the trap on the base plate, appears the unable embedding problem of loading the trap of Micro LED easily, has greatly restricted transfer yield and production efficiency. To the above problem, the utility model provides a spherical perpendicular miniature LED and display panel thereof to make the huge transfer process simple, and make the transfer efficiency far beyond traditional scheme. The technical solution of the present invention will be described in detail with reference to fig. 1 to 13.

As shown in fig. 1, a spherical vertical micro LED is used in a loading well disposed on a backplane 101 to form a micro LED array, and 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 miniature LED is as follows: the insulating layer 5 separates the first electrode 4 from 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 recombined at the light emitting layer 3 between the first semiconductor layer 1 and the second semiconductor layer 2, and energy is released in the form of photons, thereby realizing light emission.

The utility model discloses an innovation point lies in: 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 a spherical structure formed by the first semiconductor layer 1, the second semiconductor layer 2 and the light-emitting layer 3, so as to form the vertical micro LED which is spherical as a whole. Specifically, the light emitting layer 3 is disposed 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 light-emitting layer 3 or covers the light-emitting layer 3 and part of the surfaces of the first semiconductor layer 1 and the second semiconductor layer 2.

The insulating layer 5 is used for separating the first semiconductor layer 1 from the second semiconductor layer 2, so that when the spherical vertical micro LED is manufactured, the first electrode 4 completely covers the first semiconductor layer 1, the second electrode 6 completely covers the second semiconductor layer 2, and the insulating layer 5 only covers the light-emitting layer 3. In addition, as shown in fig. 1, the first electrode 4 covers a portion of the first semiconductor layer 1, the second electrode 6 covers a portion of the second semiconductor layer 2, and the insulating layer 5 covers a portion of the first semiconductor layer 1 and the second semiconductor layer 2 in addition to the light emitting layer 3. In brief, the insulating layer serves to separate the first electrode from the second electrode, and thus, structurally, the insulating layer may be provided only on the corresponding outer side of the light-emitting layer, and in addition thereto, may further extend to cover the first semiconductor layer and the second semiconductor layer.

Through the technical scheme, the first semiconductor layer 1, the second semiconductor layer 2 and the luminous layer 3 form a spherical structure, 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 through the spherical structure and the spherical structure, only a plurality of hemispherical loading wells are required to be arranged on the back plate 101, the micro LED can be effectively prevented from being clamped outside the loading wells, and therefore the spherical vertical micro LED is conveniently, quickly and efficiently transferred to the back plate 101, accurate alignment is realized, and the transfer yield and the production efficiency can be effectively improved.

The utility model discloses still creatively utilize magnetic force to improve spherical perpendicular miniature LED's transfer efficiency: preferably, the second electrode 6 is made of a magnetic conductive material, and the magnetism of the second electrode 6 is opposite to that of the magnetic metal gasket arranged in the loading well.

The magnetic conductive material is adopted as the second electrode 6, the magnetic metal gasket is arranged in the loading well, the magnetism of the second electrode 6 is opposite to that of the magnetic metal gasket, 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, the second electrode 6 of the spherical vertical micro LED is attracted by the magnetic metal gasket through the magnetic force, and therefore the spherical vertical micro LED is attracted to the loading well. In addition, the magnetic metal gasket also has an electric connection effect, and the technical scheme can not only improve the transfer efficiency of the spherical vertical micro LED, but also ensure the effective contact of the second electrode 6 and the magnetic metal gasket.

Preferably, the magnetic conductive material in the second electrode forms patterned shapes 7; as shown in fig. 14, 15, and 16, 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 arranged in a patterned shape 7; the patterned shapes 7 are also triangular or rectangular or circular or cross-shaped or ring-shaped. In short, a part of the second electrode has magnetism and another part does not have magnetism, and the surface of the sphere formed by the magnetic part can be various shapes such as triangle, square, circle and the like, and the magnetic part with the pattern is also beneficial to alignment. The term "patterned shape" as used herein refers to a shape formed by projecting a pattern on a spherical surface.

The technical scheme can be convenient for fixing different spherical vertical micro LEDs at a specific position. For example, the patterned shapes of the magnetic metal pads are arranged in a triangle and a circle, and the corresponding spherical vertical micro LEDs with the triangular and the circle magnetic conductive materials are produced. When transferring, firstly putting the triangular spherical vertical micro LED made of the magnetic conductive material, wherein most of the spherical vertical micro LED is adsorbed and fixed by the triangular magnetic metal gasket; even if a small amount of the magnetic material is adsorbed by the circular magnetic metal gasket, the magnetic force generated by the magnetic material is not strong because the shapes of the magnetic material and the magnetic material are not matched, and the magnetic material can fall off only by shaking lightly and forcefully; similarly, a spherical vertical micro-LED with a circular magnetic conductive material is placed, and the spherical vertical micro-LED is attracted and fixed by the circular magnetic metal pad. Thereby, convenient transfer is achieved.

Preferably, the surface of the second electrode 6 is provided with an alignment convex part for alignment; correspondingly, a contraposition depressed part is arranged in the loading trap, namely the contraposition depressed part is further formed in the loading trap in a depressed mode, and the shape of the contraposition raised part is matched with that of the contraposition depressed part. Specifically, the cross section of the alignment convex part can be arranged in a triangle, a rectangle, a circle, a cross or a ring shape; correspondingly, the cross section of the alignment recess is triangular or rectangular or circular or cross-shaped or annular.

As is well known, the three primary optical colors include red, green and blue, and when the three primary optical colors are mixed, all colors required for display can be formed, so that corresponding effects can be displayed on the display screen. Based on this, the utility model provides a spherical perpendicular miniature LED includes R type LED, G type LED and B type LED, and wherein, R type LED sends ruddiness, G type LED sends the green glow, and B type LED sends the blue light. In the process of manufacturing the display panel by using the spherical vertical micro-type, the R-type LEDs, the G-type LEDs and the B-type LEDs need to be arranged in a specific pattern to realize the display function. In the prior art, the volume of the LED chip is too small and the number of the LED chip is too large, so that the R-type LED, the G-type LED and the B-type LED are difficult to arrange at a specific position. The utility model can solve the problem by the shape and the external contour of the alignment convex part and the alignment concave part.

The shapes of the aligning convex parts on the R-type LED, the G-type LED and the B-type LED are different. For example, the cross section of the aligning lug boss of the R-type LED is set to be rectangular, the cross section of the aligning lug boss of the G-type LED is set to be circular, and the cross section of the aligning lug boss of the B-type LED is set to be triangular; correspondingly, the cross-section of the partial loading wells is arranged in a rectangular, circular and triangular shape according to a predetermined pattern. During the transfer, the magnetic metal gasket on all loading traps can produce magnetic force to the second electrode 6 on all spherical perpendicular miniature LEDs, but, when the shape of counterpoint bellying and counterpoint depressed part does not match, this adsorption affinity can be less, can make mismatching's emitting diode break away from backplate 101 and adsorb again through the vibration, until all match correctly to reach the effect that improves yield and production efficiency.

Generally, the LED chip can be divided into a front-mounted chip, a flip chip and a vertical chip, and the utility model relates to a miniature LED belongs to the vertical chip. Structurally, the light emitting layer of the vertical chip is located between the first semiconductor layer and the second semiconductor layer. When the semiconductor device works, photons are emitted from all directions by the light-emitting layer, and when the emitted photons point to the first semiconductor layer, the photons can be directly emitted to the outside through the first semiconductor layer and the first electrode; when the emitted photons point to the second semiconductor layer, the photons need to change direction through reflection after passing through the second semiconductor layer and the second electrode, and then are emitted to the outside through the first semiconductor layer and the first electrode. In contrast, the first electrode is made of a transparent material, and the second electrode is made of a conductive material with high reflectivity. A high-reflectivity conductive material is adopted as the second electrode, so that the light extraction efficiency is improved; and a transparent material is adopted as the first electrode, so that smooth light emergence is ensured.

Specifically, the first semiconductor layer 1 is made of n-GaN, the second semiconductor layer 2 is made of p-GaN, the light emitting layer 3 is made of InGaN or InN, the first electrode 4 is made of ITO, and the insulating layer 5 is made of silicon dioxide. Besides, the following implementation modes can be adopted: the material of the first semiconductor layer comprises one of N-type gallium arsenide, N-type copper phosphide and the like, and the material of the second semiconductor layer comprises one of P-type gallium arsenide, P-type copper phosphide and the like; the material of the luminous 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 comprises one or any combination of titanium, aluminum, nickel and alloy thereof. It should be noted that the above materials are only one of the embodiments, and 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 are not limited, and other materials that achieve the same function by the same principle should also be one of the embodiments of the present invention, and are not exhaustive here.

Correspondingly, the utility model also provides a spherical perpendicular miniature LED's preparation flow, specifically include following step:

forming an epitaxial layer on the substrate 102 by deposition, wherein the epitaxial layer comprises 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;

etching the second semiconductor layer 2 and part of the light emitting layer 3 to obtain a first chip hemisphere 105;

depositing a first insulating layer on the first chip hemisphere 105, and covering the first insulating layer on the first chip hemisphere 105;

etching the first insulating layer to expose the second semiconductor layer 2;

plating a second electrode 6 on the second semiconductor layer 2; preferably, a magnetic conductive material is used as the second semiconductor layer 2;

the first chip hemisphere 105 is overturned to cover the soft layer 104 on the bonding substrate 103;

peeling off the substrate 102 to expose the first semiconductor layer 1;

etching the first semiconductor layer 1 and part of the light-emitting layer 3 to obtain a second chip hemisphere 106;

depositing a second insulating layer on the second chip hemisphere 106 such that the second insulating layer covers the second chip hemisphere 106;

etching the second insulating layer to expose the first semiconductor layer 1;

plating a first electrode 4 on the first semiconductor layer 1;

and stripping the bonding substrate 103 and the soft layer 104 to obtain the spherical vertical micro LED.

The above-described flow is explained in accordance with the flow of the production process with reference to FIGS. 2 to 12.

As shown in fig. 2, an epitaxial layer is formed on a 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.

As shown in fig. 3, the epitaxial layer is etched to form a first hemispherical chip 105 by a dry etching process, where the first hemispherical chip 105 is a hemispherical structure left by etching away a portion of the second semiconductor layer and the light emitting layer.

As shown in fig. 4, 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.

As shown in fig. 5, the first insulating layer covering the upper portion of the first hemisphere 105 is etched away to expose the second semiconductor layer on the first hemisphere 105, and only a small portion of the first insulating layer is left at the interface between the second semiconductor layer and the light emitting layer for insulation.

As shown in fig. 6, after the second semiconductor layer is exposed on the first chip hemisphere 105, the second electrode 6 is further plated on the second semiconductor layer. Preferably, the second electrode 6 is a magnetically conductive material to provide for bulk transfer. The magnetic properties of the second electrode 6 are opposite to those of the magnetic metal pad disposed in the loading well.

After plating the second electrode 6, the first chip hemisphere 105 is turned upside down to cover the bonding substrate 103, as shown in fig. 7. The bonding substrate 103 is provided with a soft layer 104, so that the turned-over first chip hemisphere 105 is equivalent to covering the soft layer 104 on the bonding substrate 103. After this step is completed, the first chip hemisphere 105 is turned from the original upward orientation to the downward orientation.

As shown in fig. 8, the substrate 102 located at the uppermost layer at this time is peeled off to expose the first semiconductor layer 1. The semi-finished product of the spherical vertical micro LED is structurally composed of a first semiconductor layer 1, a light emitting layer 3 and a second semiconductor layer 2 from top to bottom, and a second electrode 6 covers the second semiconductor layer 2.

As shown in fig. 9, after the substrate 102 is peeled off to expose the first semiconductor layer 1, a second chip hemisphere 106 is etched by a dry etching process, where the second chip hemisphere 106 is a hemispherical structure left by etching and removing a portion 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, which is a spherical structure formed by the first semiconductor layer, the second semiconductor layer and the light emitting layer 3.

As shown in fig. 10, 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.

As shown in fig. 11, the second insulating layer covering the upper portion of the second chip hemisphere 106 is etched away to expose the first semiconductor layer on the second chip hemisphere 106, and only a small portion of the second insulating layer is left at the interface between the first semiconductor layer and the light emitting layer for insulation. The remaining first and second insulating layers combine to form an insulating layer 5 of complete structure, isolating the first and second semiconductor layers.

As shown in fig. 12, 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 made of a transparent material to facilitate the exit 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 in a spherical structure, so as to obtain the spherical vertical micro LED.

Generally speaking, through the mode of deposit and etching, form hemisphere structure twice successively on first semiconductor layer 1, second semiconductor layer 2 and luminescent layer 3 to obtain first electrode 4, insulating layer 5 and second electrode 6 through electroplating, and then form the perpendicular miniature LED of sphere, avoid miniature LED card outside the loading trap, be convenient for with the accurate counterpoint of loading trap in the in-process of transferring, can effectively improve transfer yield and production efficiency.

Correspondingly, the utility model also provides a spherical perpendicular miniature LED display panel, its actual primary structure includes a backplate 101. In particular, the spherical vertical micro LED is mounted on the back plate 101, so as to form the spherical vertical micro LED display panel.

Specifically, the back plate 101 is provided with a plurality of loading wells matched with the size of the spherical vertical micro LED, and magnetic metal gaskets matched with the second electrodes 6 are arranged in the loading wells. When a plurality of spherical vertical micro LEDs are fixed in the loading wells on the back plate 101, an array of micro LEDs is formed. And a transparent connecting circuit is plated on the first electrode 4 and is used for connecting the first electrode 4 of the spherical vertical micro LED and a first port on the back plate 101, so that the first electrode 4 is electrically connected with the outside. In addition, the second electrode 6 is connected to the second port on the back plate 101 through the magnetic metal gasket, so that the second electrode 6 is electrically connected to the outside.

Preferably, the magnetic properties of the second electrode 6 are opposite to those of the magnetic metal pad disposed in the loading well. The spherical vertical micro LED is conveniently adsorbed on the loading trap through the magnetic action in the transferring process, and the effective contact between the second electrode 6 and the magnetic metal gasket can be ensured.

Preferably, the surface of the second electrode 6 is provided with an alignment convex part for alignment; correspondingly, a contraposition depressed part is arranged in the loading trap, and the shape of the contraposition raised part is matched with that of the contraposition depressed part. In addition, the cross section of the alignment bulge part is triangular, rectangular, circular, cross-shaped or annular; correspondingly, the cross section of the alignment recess is triangular or rectangular or circular or cross-shaped or annular. Specifically, the spherical vertical micro-LEDs include R-type LEDs, G-type LEDs, and B-type LEDs, and the diameters of the spherical structures of the R-type LEDs, the G-type LEDs, and the B-type LEDs are different from each other.

Correspondingly, the utility model discloses still a spherical perpendicular miniature LED display panel's transfer flow, including following step:

as shown in fig. 13, first, a plurality of spherical vertical micro LEDs, which are the spherical vertical micro LEDs described above, are placed in a suspension;

secondly, putting a back plate 101 into the suspension liquid, and enabling the spherical vertical micro LED to float above the back plate 101; a plurality of loading wells are arranged on the back plate 101, and form a loading well array; a magnetic metal gasket is arranged in the loading trap, the second electrode 6 is made of a magnetic conductive material, and the magnetism of the second electrode 6 is opposite to that of the magnetic metal gasket arranged in the loading trap.

And thirdly, adsorbing the spherical vertical micro LED in the loading trap through the magnetic force between the second electrode 6 and the magnetic metal gasket to form a micro LED array, and finishing the transfer.

It should be noted that the above is only the process of transferring the spherical vertical micro-LEDs onto the backplane, and does not include the packaging process. Further packaging is required to form a whole spherical vertical micro LED display panel.

A large number of spherical vertical micro LEDs are placed in the suspension, magnetic metal pads having magnetism opposite to that of the second electrodes 6 are arranged on the back plate 101, and the spherical vertical micro LEDs are adsorbed in the loading wells under the action of magnetic force, so that the spherical vertical micro LEDs are accurately aligned to the loading wells of the back plate 101. The magnetic metal gasket has two realization modes, namely, a magnetic material is adopted as the magnetic metal gasket, and magnetic force exists directly; secondly, magnetic force is generated after electrification by utilizing electromagnetic induction. While the suspension flows, the second electrode 6 and the second metal pad are attracted to each other by the attraction of the magnetic electrode.

The spherical vertical micro-LEDs include R-type LEDs, G-type LEDs, and B-type LEDs. The surface of the second electrode is provided with an alignment bulge part for alignment; correspondingly, a contraposition depressed part is arranged in the loading trap, and the shape of the contraposition raised part is matched with that of the contraposition depressed part. The shapes or the sizes of the aligning convex parts on the R-type LED, the G-type LED and the B-type LED are different. For example, the cross section of the aligning lug boss of the R-type LED is set to be rectangular, the cross section of the aligning lug boss of the G-type LED is set to be circular, and the cross section of the aligning lug boss of the B-type LED is set to be triangular; correspondingly, the cross-section of the partial loading wells is arranged in a rectangular, circular and triangular shape according to a predetermined pattern. During the transfer, the magnetic metal gasket on all loading traps can produce magnetic force to the second electrode on all spherical perpendicular miniature LEDs, but, when the shape of counterpoint bellying and depressed part does not match, this adsorption affinity can be less, can make mismatching's emitting diode break away from the backplate and adsorb again through the vibration, until all matches correctly to reach the effect that improves yield and production efficiency.

In addition to differentiating the different spherical vertical micro LEDs by setting the alignment convex portions and the alignment concave portions to different shapes, the different spherical vertical micro LEDs may also be differentiated by setting the spherical structures of the different spherical vertical micro LEDs to different sizes. For example, the R-type LED is provided in a sphere structure having a radius of R1, the G-type LED is provided in a sphere structure having a radius of R2, and the B-type LED is provided in a sphere structure having a radius of R3; correspondingly, the partial-loading traps are arranged in a predetermined pattern in a circle with cross-sectional radii R1, R2 and R3. Therefore, the effect of improving the yield and the production efficiency can be achieved.

To sum up, the utility model provides a spherical perpendicular miniature LED and display panel thereof through the mode of deposit and etching, successively forms twice hemisphere structure on first semiconductor layer 1, second semiconductor layer 2 and luminescent layer 3 to obtain first electrode 4, insulating layer 5 and second electrode 6 through electroplating, and then form the spherical perpendicular miniature LED and avoid miniature LED card outside loading the trap, be convenient for at the in-process that shifts and the accurate counterpoint of loading the trap, can effectively improve transfer yield and production efficiency.

Assuming that R1 is larger than R2 is larger than R3, when the suspension liquid is used for transferring and assembling, the sizes of the three LEDs with different colors, namely the R type LED, the G type LED and the B type LED, are different, and the LEDs can be transferred from large to small. For example, when the largest R-type LED is transferred first, the R-type LED is only stably adsorbed and fixed in the loading well with the size of R1, and at this time, even if a small number of R-type LEDs are adsorbed in the loading well with the size of R2 or R2, since the sizes of the parts are not matched, the generated magnetic force is not strong, and the R-type LEDs can be separated only by shaking with slight force. By the same reason, the G-type LED and the B-type LED can be transferred in sequence, so that the transfer efficiency is greatly improved.

It is to be understood that the invention is not limited to the above-described embodiments, and that modifications and variations may be made by those skilled in the art in light of the above teachings, and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.

Claims

1. A spherical vertical micro LED, comprising:

2. The spherical vertical micro LED of claim 1, wherein: the second electrode comprises a magnetic conductive material, and the magnetism of the second electrode is opposite to that of the magnetic metal gasket arranged in the loading well.

3. The spherical vertical micro LED of claim 2, wherein: the magnetic conductive material in the second electrode forms a patterned shape.

4. The spherical vertical micro LED of claim 3, wherein: the patterned shape is a triangle or a rectangle or a circle or a cross or a ring.

5. The spherical vertical micro LED of claim 3, wherein: the spherical vertical micro LED comprises an R-type LED, a G-type LED and a B-type LED, wherein the diameters of spherical structures on the R-type LED, the G-type LED and the B-type LED are different.

6. The spherical vertical micro LED of claim 1, wherein: the first electrode is made of a transparent material, and the second electrode is made of a high-reflectivity conductive material.

7. The spherical vertical micro LED of claim 6, wherein: the material of the first electrode is ITO.

8. The spherical vertical micro LED of claim 6, wherein: the second electrode is made of silver.

9. The spherical vertical micro LED of claim 1, wherein: 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, and the material of the insulating layer is silicon dioxide.

10. The utility model provides a miniature LED display panel is perpendicular to spherical which characterized in that includes:

a plurality of spherical vertical micro-LEDs, the spherical vertical micro-LEDs of any of claims 1-9, the plurality of spherical vertical micro-LEDs being disposed in the plurality of loading wells, respectively, forming a micro-LED array;