Micro-LED display chip and its manufacturing method

Abstract

The present invention provides a Micro-LED display chip and a manufacturing method thereof. The method includes providing a driving substrate including a driving circuit and a contact electrically connected to the driving circuit, providing a first LED layer including a plurality of first LED units, a first filling structure located between the first LED units, and a first columnar conductor penetrating the first filling structure, bonding the first LED layer and the driving substrate, electrically connecting the first LED units and the first columnar conductor to the contact respectively, disposing a second LED layer on the first LED layer, the second LED layer including a plurality of second LED units and a second filling structure located between the second LED units, electrically connecting the second LED units to the first columnar conductor directly below them, and the emission colors of the second LED units and the first LED units being different. It is advantageous for reducing the difficulty of the manufacturing process of a full-color Micro-LED display chip.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from a PCT application with application number PCT / CN2023 / 098893 filed with the China Patent Office on June 15, 2022 (which PCT application claimed priority from a Chinese patent application with application number 202210675860.X filed with the China Patent Office on June 15, 2022, entitled "Micro-LED display chip and manufacturing method thereof"), the entire contents of which are hereby incorporated by reference into this application.

[0002] The present specification relates to the field of semiconductor electronic components, and in particular to a Micro-LED display chip and a manufacturing method thereof. [Background technology]

[0003] With the emergence of Micro-LED display technology, high-resolution micro devices are being created for display devices such as Augmented Reality (AR), Near-Eye Display (NED) devices, and wearable display devices. Micro-LED has great market potential due to its advantages such as small size, high brightness, fast response, and long lifespan.

[0004] Currently, Micro-LED full-color display chips typically incorporate a wavelength conversion layer into a monochrome display chip to set the three primary colors RGB required for full-color display, thereby meeting the full-color display requirements. However, the LED array in a Micro-LED display is densely packed, and the LED pixel pitch within the array is in the 0.1-100 micron range. The smaller the pixel of the Micro-LED display chip, the more difficult it is to fabricate the wavelength conversion layer, making it significantly more difficult to fabricate a Micro-LED display chip for color display. Summary of the Invention

[0005] In light of this, several embodiments of this specification propose a Micro-LED display chip and its manufacturing method for realizing multi-color or full-color display of the Micro-LED display chip, aiming to reduce the difficulty of manufacturing the multi-color or full-color Micro-LED display chip, to some extent avoid damage to the driving substrate during the manufacturing process, improve yield, and reduce manufacturing costs.

[0006] In an embodiment of the present specification, a method for manufacturing a micro-LED display chip is provided, the method including: providing a driving substrate including a driving circuit and contacts electrically connected to the driving circuit; providing a first LED layer including a plurality of first LED units, a first filling structure located between the first LED units, and a first columnar conductor penetrating the first filling structure; bonding the first LED layer and the driving substrate so that the first LED units and the first columnar conductors are electrically connected to the contacts, respectively; and arranging a second LED layer on the first LED layer, the second LED layer including a plurality of second LED units and a second filling structure located between the second LED units, the second LED units being electrically connected to the first columnar conductor directly below them, and the second LED units and the first LED units having different emission colors.

[0007] An embodiment of the present specification provides a micro-LED display chip, comprising: a driving substrate including a driving circuit and contacts electrically connected to the driving circuit; a first LED layer including a plurality of first LED units, a first filling structure located between the first LED units, and a first columnar conductor penetrating the first filling structure, the first LED layer being disposed on the driving substrate so as to be electrically connected to the contacts together with the first columnar conductors; and a second LED layer including a plurality of second LED units and a second filling structure located between the second LED units, the second LED layer being electrically connected to the first columnar conductor directly below the second LED unit, and disposed on the first LED layer so as to have a different emission color from the first LED units.

[0008] In an embodiment of the present specification, a display panel is provided, and the display panel includes any of the above-mentioned Micro-LED display chips.

[0009] In an embodiment of the present specification, a display device is provided, which includes any of the above-mentioned Micro-LED display chips.

[0010] The manufacturing method of the micro-LED display chip according to the embodiment of the present specification includes: 1st The LED display chip achieves multicolor display even without a wavelength conversion layer, thereby reducing the difficulty of manufacturing the LED chip.

[0011] Furthermore, after forming the first LED layer and the second LED layer respectively, the first LED layer and the second LED layer are sequentially connected to the driving substrate, so that the driving substrate drives and controls the first LED unit and the second LED unit respectively, thereby reducing the number of times the driving substrate is inserted into the process, protecting the driving substrate and preventing damage to the driving substrate during the manufacturing process to some extent, thereby improving the yield of Micro-LED display chips to some extent and reducing costs. [Brief explanation of the drawings]

[0012] [Figure 1] 1A and 1B are diagrams illustrating a structure of a drive substrate according to an embodiment. [Figure 2a-2m] 1A to 1C are diagrams illustrating the structure of each manufacturing stage in a method for manufacturing a Micro-LED display chip according to an embodiment. [Figures 3a-3h]1A to 1C are diagrams illustrating the structure of each manufacturing stage in a method for manufacturing a Micro-LED display chip according to an embodiment. [Figure 4] FIG. 2 shows the structure of a second LED layer according to one embodiment. [Figure 5] FIG. 2 shows the structure of a third LED layer according to one embodiment. [Figure 6] FIG. 1 is a diagram showing the structure of a Micro-LED display chip according to one embodiment. [Figure 7] FIG. 1 is a diagram showing the structure of a Micro-LED display chip according to one embodiment. [Figure 8] FIG. 1 is a diagram showing the structure of a Micro-LED display chip according to one embodiment. [Figure 9] FIG. 1 is a diagram showing the structure of a Micro-LED display chip according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the technical solutions of some embodiments of this specification will be clearly and fully described with reference to the drawings of some embodiments of this specification, but it is clear that the described embodiments are only some embodiments of this specification and not all embodiments. All embodiments that a person skilled in the art can obtain based on the embodiments in this specification without performing any creative work are within the scope of this specification.

[0014] An embodiment of the present specification provides a method for manufacturing a Micro-LED display chip, which includes the following steps:

[0015] S110: Providing a driving substrate 300, the driving substrate 300 including a driving circuit and a contact point electrically connected to the driving circuit.

[0016] Referring to FIG. 1 , in some embodiments, the drive substrate 300 includes a semiconductor material. The semiconductor material may be at least one of silicon, silicon carbide, gallium nitride, germanium, gallium arsenide, indium phosphide, etc. The drive substrate 300 may be made of a non-conductive material, such as glass, plastic, or a sapphire wafer. The drive substrate 300 may be a CMOS substrate or a TFT substrate. The drive substrate 300 includes a drive circuit (not shown in FIG. 1 ) that provides electrical signals to the LED units and controls the brightness of the LED units using the electrical signals. The LED unit may be understood to mean one or more of the first LED unit 210, the second LED unit 410, and the third LED unit 510.

[0017] Referring to FIG. 1 , in some embodiments, the driving substrate 300 includes contacts 310. There may be multiple contacts 310, and the contacts 310 may be spaced apart from one another. The material of the contacts 310 includes at least one of Cu, Ag, Au, Al, W, Mo, Ni, Ti, Pt, Pd, etc. The contacts 310 are connected to the driving circuit and the LED unit, respectively, thereby electrically connecting the driving circuit and the LED unit, thereby enabling the driving circuit to drive the LED unit and causing the LED unit to emit light. The contacts 310 may be located on the surface of the substrate, which is advantageous for electrically connecting the driving circuit and the LED unit.

[0018] S120: Provide a first LED layer 200. The first LED layer 200 includes a plurality of first LED units 210, first filling structures 220 positioned between the first LED units 210, and first columnar conductors 221 penetrating the first filling structures 220.

[0019] 2a, in some embodiments, the first LED unit 210 is formed by processing a first LED epitaxial layer 200a including a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213. In the first LED epitaxial layer 200a, a partial area of ​​the first doped semiconductor layer 211, the active layer 212, and a partial thickness of the second doped semiconductor layer 213 can be removed to form the first LED unit 210.

[0020] In some embodiments, the materials of the first doped semiconductor layer 211 and the second doped semiconductor layer 213 may be II-VI or III-V nitrides. Specifically, for example, the first doped semiconductor layer 211 and the second doped semiconductor layer 213 may each be a single-layer or multi-layer semiconductor structure made of one or more of ZnSe, ZnO, GaN, AlN, InN, InGaN, GaP, AlInGaP, or AlGaAs. The active layer 212 may have a single quantum well structure, a multi-quantum well (MQW) structure, or a structure in which quantum wells and barrier layers are stacked. The active layer 212 is located between the first doped semiconductor layer 211 and the second doped semiconductor layer 213. Holes and electrons are excited in the active layer 212 when light of a specific wavelength is emitted.

[0021] In some embodiments, the first doped type semiconductor layer 211 may be a P-type semiconductor layer, and the second doped type semiconductor layer 213 may be an N-type semiconductor layer. The first doped type semiconductor layer 211 and the second doped type semiconductor layer 213 may be electrically connected to a contact 310 and a common electrode 600, respectively, and the common electrode 600 may be a cathode. The contact 310 may be electrically connected to the first doped type semiconductor layer 211 through an anode. In some embodiments, the first doped type semiconductor layer 211 may be an N-type semiconductor layer, while the second doped type semiconductor layer 213 is a P-type semiconductor layer.

[0022] Referring to Figure 2a, in some embodiments, the first LED epitaxial layer 200a includes a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213. The first LED epitaxial layer 200a may be grown on a substrate 100. The substrate 100 may be any of a sapphire, Si, GaAs, InP, GaN, AlN, SiC substrate, etc.

[0023] In some embodiments, the first LED layer 200 includes a plurality of first LED units 210, which can be driven independently. The first LED units 210 include a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213. The first doped semiconductor layer 211 may be used for electrical connection to the contact 310, and the second doped semiconductor layer 213 may be used for electrical connection to the common electrode 600.

[0024] In some embodiments, a conductive layer may be formed on the first doped semiconductor layer 211 of the first LED unit 210. The conductive layer may be a metallic material or indium tin oxide. The first LED unit 210 and the contacts are electrically connected through the conductive layer of the first doped semiconductor layer 211.

[0025] 2a and 2b. In some embodiments, the step of providing a first LED layer includes providing a first LED epitaxial layer 200a and etching the first LED epitaxial layer 200a to form a plurality of first LED units 210, each of the first LED units 210 including a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213, and the second doped semiconductor layers 213 of adjacent first LED units 210 are connected to each other. It can be seen that the first LED epitaxial layer 200a includes the first doped semiconductor layer 211, the active layer 212, and the second doped semiconductor layer 213, and that removing a portion of the first doped semiconductor layer 211, the active layer 212, and a portion of the thickness of the second doped semiconductor layer 213 forms the plurality of first LED units 210. A portion of the first doped semiconductor layer 211, the active layer 212, is completely removed, but the second doped semiconductor layer 213 is partially retained. Accordingly, a plurality of first LED units 210 are formed, and the first LED units 210 are connected to each other via the second doped semiconductor layer 213. FIG. 2b shows two first LED units 210 connected by the second doped semiconductor layer 213. A portion of the first LED epitaxial layer 200a may be removed by an etching process. Specifically, the etching process may be dry etching or wet etching.

[0026] In some embodiments, the step of providing the first LED layer 200 includes providing a first LED epitaxial layer 200a, and etching the first LED epitaxial layer 200a to form a plurality of spaced-apart first LED units 210, each of the first LED units 210 including a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213. Specifically, the first LED epitaxial layer 200a may be provided, where the first LED epitaxial layer 200a includes the first doped semiconductor layer 211, the active layer 212, and the second doped semiconductor layer 213, and some regions of the first LED epitaxial layer 200a may be removed to form the plurality of spaced-apart first LED units 210. A portion of the first LED epitaxial layer 200a is removed, while a plurality of first LED units 210 are formed in the remaining first LED epitaxial layer 200a, and a spatial gap is provided between the plurality of first LED units 210, thereby forming a plurality of first LED units 210 spaced apart from one another.

[0027] In some embodiments, the first LED units 210 are independent of each other, and are formed by removing part or all of the thickness of the first LED epitaxial layer 200a in some regions, so that the first LED epitaxial layer 200a is not held between the multiple first LED units 210, or only part of the thickness of the epitaxial layer 200a of the first LED unit 210 is held. Therefore, an uneven surface is formed between the multiple first LED units 210.

[0028] See FIG. 2c. In some embodiments, the step of providing a first LED layer includes disposing the first filling structure 220 between the first LED units 210. The first LED layer 200 includes the first filling structure 220 that causes the plurality of first LED units 210 to form a first flat surface. By disposing the first filling structure 220, the unevenness of the surface formed by the plurality of first LED units 210 is reduced. By disposing the first filling structure 220, the thickness of the first LED layer 200 in each region is approximately the same, thereby forming the first flat surface.

[0029] In some embodiments, the first filling structure 220 is disposed between the first LED units 210, and the first filling structure 220 is positioned at least in the circumferential direction of the first LED units 210. See FIG. 2c. The first filling structure 220 may be positioned in the circumferential direction of the first LED units 210. See FIG. 3a. Alternatively, the first filling structure 220 covers the first LED units 210. Specifically, The first filling structure 220 is positioned in the circumferential direction of the first LED unit 210 and covers the surface of the first doped semiconductor layer 211 of the first LED unit 210 opposite to the second doped semiconductor layer 213 of the first LED unit 210. The first filling structure 220 may be formed by at least one process such as deposition, coating, etc. The material of the first filling structure 220 may be selected from polyimide, wall protection tape, OC adhesive, SU8 photoresist, or benzocyclobutene (BCB). In some embodiments, when the first LED units 210 are spaced apart from one another, the first filling structure 220 is located at least between the first LED units 210. The first filling structure 220 may be located between the first LED units 210, or the first filling structure 220 may be located between the first LED units 210 and cover the first LED units 210. See FIG. 2d. In some embodiments, a first columnar conductor 221 is disposed in the first filling structure 220 and penetrates the first filling structure 220. A first opening is formed through the first filling structure 220, and a conductive material is disposed in the first opening to form the first columnar conductor 221. The material of the first columnar conductor 221 may be a transparent conductive material. Specifically, for example, the transparent conductive material may be indium tin oxide. Of course, the material of the first columnar conductor 221 may also include a metal material. The first columnar conductor 221 is used to electrically connect the first LED unit 210 to the contact 310. The first columnar conductor 221 is also used to electrically connect an LED unit having a different emission color from the first LED unit 210 to the contact 310. For example, the first columnar conductor 221 is used to electrically connect a second LED unit to the contact 310.

[0030] The first LED layer 200 includes a first filling structure 220, which is beneficial for planarizing the first LED layer 200 and reducing the difficulty of bonding the first LED layer to the driving substrate 300. The first filling structure 220 also serves to protect and stabilize the first LED units. Even for the first LED units 210 that are spaced apart from each other, the first filling structure 220 improves the difficulty of bonding the first LED units 210 to the driving substrate 300 and the stability after bonding between the first LED units 210 and the driving substrate 300, thereby reducing the risk of peeling of the first LED units 210 during the manufacturing process and improving the yield of Micro-LED display chips.

[0031] S130: The first LED layer 200 and the driving substrate 300 are bonded together, and the first LED unit 210 and the first columnar conductor 221 are electrically connected to the contacts 310, respectively.

[0032] 2e. In some embodiments, the first LED units 210 and the first columnar conductors 221 are each electrically connected to the contact 310. The first LED layer 200 includes first columnar conductors 221 located between the first LED units 210. The first LED layer 200 also includes first columnar conductors 221 in contact with the first doped semiconductor layers 211 of the first LED units 210. The first LED units 210 are electrically connected to the contact 310 via the first columnar conductors 221. In some embodiments, the first filling structures 220 are located only in the circumferential direction of the first LED units 210, and the first columnar conductors 221 may not be located between the first LED units 210 and the first columnar conductors 221, but the first LED units 210 are electrically connected to the contact 310 via the first doped semiconductor layers 211.

[0033] The process flow of forming the first LED layer 200 including the first LED units 210, the first filling structures 220, and the first columnar conductors 221 and then bonding the driving substrate 300 protects the driving substrate 300 and improves yield. If the first LED layer 200 is defective, only the first LED layer 200 is repaired or discarded without affecting the driving substrate 300, which is advantageous for reducing costs.

[0034] S140: A second LED layer 400 is arranged on the first LED layer 200, and the second LED layer 400 includes a plurality of second LED units 410 and second filling structures 420 located between the second LED units 410, and the second LED units 410 are electrically connected to the first columnar conductors 221 directly below them, and the second LED units 410 and the first LED units 210 have different emission colors.

[0035] 2c, 2b, and 2f. In some embodiments, when the first LED epitaxial layer 200a is etched to form a plurality of first LED units 210, each of the first LED units 210 including a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213, and the second doped semiconductor layers 213 of adjacent first LED units 210 are connected to each other, before the step of arranging the second LED layer 400 on the first LED layer, the method further includes thinning the second doped semiconductor layer 213 of the first LED unit 210 until the tips of the first columnar conductors 221 are exposed, and the plurality of first LED units 210 are spaced apart from each other after thinning. The second doped semiconductor layer 213 of the first LED unit 210 may be thinned by etching, or each region of the second doped semiconductor layer 213 may be thinned simultaneously. Due to the surface contact between the first filling structure 220 and the second doped semiconductor layer 213, the first columnar conductor 221 penetrates the first filling structure 220. Therefore, when the tip of the first columnar conductor 221 is exposed, the second doped semiconductor layer 213 that realizes the connection of the multiple first LED units 210 is blocked, and the surface of the first columnar conductor 221 opposite to the first doped semiconductor layer 211 is exposed, so that the multiple first LED units 210 are spaced apart from each other, and the first filling structure 220 is between the first LED units 210.

[0036] By retaining a portion of the thickness of the second doped semiconductor layer 213 and thinning the second doped semiconductor layer 213 after bonding the first LED layer 200 and the driving substrate 300, the stability of the first LED unit 210 is improved and the first LED unit 210 is prevented from falling off during the bonding process. In addition, after being thinned, the first LED units 210 are spaced apart from one another, which contributes to the electrical connection and independent driving of the second LED unit 410 and the contact 310.

[0037] In some embodiments, the first LED layer 200 is disposed on the surface of the substrate 100, or the first LED epitaxial layer 200a is grown on the substrate 100. Before thinning the second doped semiconductor layer 213 of the first LED unit 210, the removal of the substrate 100 is included. Retaining a portion of the thickness of the second doped semiconductor layer 213 reduces the risk of simultaneously removing the first LED unit 210 during the substrate 100 removal process, thereby improving the manufacturing yield to some extent.

[0038] In some embodiments, after forming the plurality of spaced-apart first LED units 210, a conductive layer is formed on the second doped semiconductor layer 213 of the first LED unit 210. The conductive material of the conductive layer is a metal material or indium tin oxide. The first LED unit 210 is electrically connected to the second columnar conductor 421 through the conductive layer of the second doped semiconductor layer 213. FIG. 2f does not show the conductive layer of the second doped semiconductor layer 213. In some embodiments, a conductive layer is disposed on the surface of the first and second doped semiconductor layers of the LED unit, and the conductive layer is used to electrically connect the LED unit to a corresponding contact or a corresponding columnar conductor. The LED unit may be the first LED unit, the second LED unit, or the third LED unit.

[0039] 2g and 2h, in some embodiments, the step of disposing the second LED layer 400 on the first LED layer 200 includes providing a second LED layer 400, the second LED layer 400 including a plurality of second LED units 410 and second filling structures 420 positioned between the second LED units 410, bonding the second LED layer 400 to the first LED layer 200, and electrically connecting the second LED units 410 to the first pillar-shaped conductors 221 directly below the second LED units 410, thereby achieving electrical connection with the contacts 310.

[0040] In some embodiments, the second LED epitaxial layer 400a includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer, and with reference to FIG. 2a, it can be understood that the first doped semiconductor layer, the active layer, and the second doped semiconductor layer are not shown in FIG. 2g, respectively. The active layer included in the second LED epitaxial layer 400a and the active layer 212 included in the first LED epitaxial layer 200a may be different, thereby realizing the second LED unit 410 and the first LED unit 210 having different emission colors. The first doped semiconductor layer and the second doped semiconductor layer included in the second LED epitaxial layer 400a may be the same as or different from the first doped semiconductor layer 211 and the second doped semiconductor layer 213 included in the first LED epitaxial layer 200a.

[0041] In some embodiments, the second LED units 410 are formed by processing a second LED epitaxial layer 400a including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer, and refer to the formation of the first LED unit 210. The second LED units 410 formed after processing the second LED epitaxial layer 400a may be spaced apart from each other or connected via the second doped semiconductor layer. Figure 2h shows two second LED units 410.

[0042] In some embodiments, the second filling structure 420 refers to the first filling structure 220. See Figure 2i. In some embodiments, the second filling structure 420 is located at least circumferentially around the second LED unit 410. Specifically, the second filling structure 420 may be located circumferentially around the second LED unit 410, but the second filling structure 420 may also cover the second LED unit 410.

[0043] In some embodiments, a conductive layer may be formed on the surface of the first doped semiconductor layer of the second LED unit 410. The conductive material of the conductive layer is a metal material or indium tin oxide. The second LED unit 210 and the first columnar conductor 221 are electrically connected through the conductive layer of the first doped semiconductor layer of the second LED unit 210. The conductive layer on the surface of the first doped semiconductor layer is not shown in Figures 2j and 2k.

[0044] 2j. In some embodiments, second columnar conductors 421 are disposed in the second LED layer 400, penetrating the second filling structure 420, and the number and positions of the second columnar conductors 421 are determined by the first LED unit 210. The second LED layer 400 includes second columnar conductors 421 located directly above the first LED unit 210. The second columnar conductors 421 are used to electrically connect the first LED unit 210 and the common electrode 600.

[0045] See FIG. 2k. In some embodiments, the second LED unit 410 achieves electrical connection with the contact 310 through electrical connection with the first columnar conductor 221 directly below it. In some embodiments, the second LED unit 410 and the first LED unit 210 are spaced apart from each other. The orthogonal projection of the first columnar conductor 221 directly below the second LED unit 410 on the second LED unit 410 is located within the first doped semiconductor layer of the second LED unit 410. The first doped semiconductor layer of the second LED unit 410 is electrically connected to the first columnar conductor 221 directly below the second LED unit 410, thereby achieving electrical connection between the second LED unit 410 and the contact 310. In some embodiments, the first doped semiconductor layer of the second LED unit 410 and the first columnar conductor 221 are electrically connected, achieving electrical connection through direct contact.

[0046] In some embodiments, the second LED layer 400 has second columnar conductors 421 disposed therein, penetrating the second filling structure 420. The second columnar conductors 421 disposed directly above the first LED units 210 are electrically connected to the second doped semiconductor layers 213 of the first LED units 210, which is advantageous for electrical connection between the first LED units 210 and the common electrode 600. The emission color of the second LED units 410 and the emission color of the first LED units 210 are different, which allows for multicolor display without a wavelength conversion structure, and reduces the difficulty and improves the efficiency of fabrication.

[0047] See FIG. 2l. In some embodiments, the second LED epitaxial layer 400a is disposed on the substrate 100. When the second LED layer 400 and the first LED layer 200 are bonded, the substrate 100 is removed. When the second LED layer 400 is connected to the second doped semiconductor layer of the second LED unit 410, the second LED layer 400 is thinned until the tips of the second columnar conductors 421 are exposed. Specifically, the above-mentioned thinning of the second doped semiconductor layer 213 of the first LED unit 210 until the tips of the first columnar conductors 221 are exposed can be referred to, and therefore will not be described here.

[0048] In some embodiments, the second LED layer 400 is disposed on the first LED layer 200 by bonding the second LED units 410 to the first LED layer 200, respectively, and disposing a second filling structure 420 between the second LED units 410. Also, a second columnar conductor 421 may be disposed through the second filling structure 420.

[0049] In the manufacturing method of the Micro-LED display chip according to the embodiment of the present specification, the second LED unit 410 and the first LED unit 210 having different emission colors are arranged, thereby realizing multi-color display even without a wavelength conversion layer. Because the LED units of the Micro-LED display chip are small in size, the wavelength conversion layer is difficult to manufacture and has low conversion efficiency. Therefore, by arranging the second LED unit 410 and the first LED unit 210 having different emission colors, the manufacturing difficulty is reduced and the luminous efficiency is improved. The process flow of forming the first LED layer 200 including the first LED unit 210, the first filling structure 220, and the first columnar conductors 221, and then bonding the first LED layer 200 to the driving substrate 300 protects the driving substrate 300, improves yield, and reduces costs.

[0050] In some embodiments, the first LED unit 210 and the second LED unit 410 are driven independently by electrically connecting the second doped semiconductor layer and the second columnar conductor 421 of the second LED unit 410 to a common electrode 600, respectively.

[0051] See Figure 2m. In some embodiments, the second doped semiconductor layer 213 and the second columnar conductor 421 of the second LED unit 410 are electrically connected to the common electrode 600 by direct contact, or by providing other conductive structures to achieve the electrical connection.

[0052] In some embodiments, a common electrode 600 is disposed on the surface of the second LED layer 400 opposite to the driving substrate 300, and the second doped semiconductor layer 213 and the second columnar conductor 421 of the second LED unit 410 are electrically connected to the common electrode 600, so that the second LED unit 410 and the first LED unit 210 are driven independently. The common electrode 600 is advantageous in reducing the difficulty of driving.

[0053] In some embodiments, a plurality of common electrodes 600 are disposed, where the second doped semiconductor layer 213 and the second columnar conductors 421 of the second LED unit 410 are electrically connected to the common electrode 600, respectively. Each second LED unit 410 and each first LED unit 210 may be disposed with a corresponding common electrode 600.

[0054] 3a, 3b, and 3c. In some embodiments, the first LED unit 210 is electrically connected to the contact 310 of the driving substrate 300 via a corresponding first pillar-shaped conductor 221. Specifically, in the first LED layer 200, the first filling structure 220 covers the first LED unit 210, and the step of arranging the first pillar-shaped conductor 221 penetrating the first filling structure 220 includes arranging the first pillar-shaped conductor 221 on the first LED unit 210, and the first LED unit 210 is electrically connected to the contact 310 via the corresponding first pillar-shaped conductor 221.

[0055] In some embodiments, the first filling structure 220 covers the first doped semiconductor layer 211 of the first LED unit 210 by disposing a through-hole in the first doped semiconductor layer 211 for passing through the first filling structure 220, and filling the through-hole with a conductive material to form a first columnar conductor 221 for connecting the first LED unit 210. Meanwhile, the first LED layer 200 and the driving substrate 300 are joined, and the first columnar conductor 221 for connecting the first LED unit 210 realizes an electrical connection between the first LED unit 210 and the contact 310, and the first LED unit 210 and the contact 310 realize an electrical connection through an indirect connection.

[0056] By arranging the first filling structure 220 to cover the first LED unit 210, the difficulty of manufacturing the first filling structure 220 is reduced, and by arranging the first columnar conductor 221, the bonding strength between the first LED layer 200 and the driving substrate 300 is improved, peeling of the first LED layer and the driving substrate 300 during the manufacturing process is avoided, and yield is improved.

[0057] See Fig. 3e. In some embodiments, the second filling structure 420 covers the second LED unit 410 by disposing a through-hole in the second filling structure 420 of the first doped semiconductor layer covering the second LED unit 410, and filling the through-hole with a conductive material to form a second columnar conductor 421 for connecting the second LED unit 410 and the first columnar conductor 221. Meanwhile, the second LED unit 410 is electrically connected to the contact 310 via the first columnar conductor 221 and the second columnar conductor 421. The second LED unit 410 and the first columnar conductor 221 achieve an electrical connection through an indirect connection.

[0058] 3b, 3d, 3e and 4, the second filling structure 420 has second pillar-shaped conductors 421 disposed therein, penetrating the second filling structure 420, and the second pillar-shaped conductors 421 are electrically connected to the first pillar-shaped conductors 221 directly below them.

[0059] See FIG. 3f. In some embodiments, the second LED epitaxial layer 400a is disposed on the substrate 100. When the second LED layer 400 and the first LED layer 200 are bonded, the substrate 100 is removed. When the second LED layer 400 is connected to the second doped semiconductor layer of the second LED unit 410, the second LED layer 400 is thinned until the tips of the second columnar conductors 421 are exposed. Specifically, the above-mentioned thinning of the second doped semiconductor layer 213 of the first LED unit 210 until the tips of the first columnar conductors 221 are exposed can be referred to, and therefore will not be described here.

[0060] In some embodiments, a conductive layer may be formed on the surface of the second doped semiconductor layer of the second LED unit 410. The conductive material of the conductive layer may be a metal material or indium tin oxide. The conductive layer of the second doped semiconductor layer of the second LED unit 210 is used to electrically connect the second LED unit 210 and the third columnar conductor 521.

[0061] 3g and 5. In some embodiments, the manufacturing method of the Micro-LED display chip further includes disposing a third LED layer 500 on the second LED layer 400, wherein the third LED layer 500 includes a plurality of third LED units 510 and third filling structures 520 positioned between the third LED units 510, the third LED units 510 being electrically connected to the contacts 310 via first columnar conductors 221 and second columnar conductors 421 directly below the third LED units 510, and the third LED units 510, the second LED units 410, and the first LED units 210 emitting different colors of light. By disposing the second columnar conductors 421 electrically connected to the first columnar conductors 221 and the third LED units emitting different colors of light from the first and second LED units, the color display range of the Micro-LED display chip and the application range of the Micro-LED display chip are expanded.

[0062] In some embodiments, the third LED unit 510 is formed by processing a third epitaxial layer including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer. The third LED unit 510 includes a stack of the first doped semiconductor layer, the active layer, and the second doped semiconductor layer. The manufacturing process for the first LED unit 210 can be referenced, and is therefore omitted here.

[0063] In some embodiments, a conductive layer is formed on the surface of the first doped semiconductor layer of the third LED unit 510. The conductive material of the conductive layer is a metal material or indium tin oxide. When the third columnar conductor 521 is not disposed directly below the third LED unit 510, the third LED unit 510 and the second columnar conductor 421 are electrically connected by the conductive layer on the first doped semiconductor layer of the third LED unit 510.

[0064] See Figures 3g and 5. In some embodiments, the third filling structure 520 covers the third LED unit 510 by disposing a through-hole penetrating the third filling structure 520 in the first doped semiconductor layer, and filling the through-hole with a conductive material to form a third columnar conductor 521 for electrically connecting the third LED unit 510. Meanwhile, the third LED unit 510 is electrically connected to the contact 310 via the first columnar conductor 221, the second columnar conductor 421, and the third columnar conductor 521 directly below it. The third LED unit 510 and the second columnar conductor 421 achieve an electrical connection through an indirect connection.

[0065] In some embodiments, a conductive layer is formed on the surface of the first doped semiconductor layer of the third LED unit 510. The conductive material of the conductive layer is a metal material or indium tin oxide. The third LED unit 510 and the third columnar conductor 521 are electrically connected through the conductive layer on the first doped semiconductor layer of the third LED unit 510.

[0066] In some embodiments, the light emitting color of the third LED unit 510, the light emitting color of the second LED unit 410, and the light emitting color of the first LED unit 210 may be different, and the light emitting color of the third LED unit 510, the light emitting color of the second LED unit 410, and the light emitting color of the first LED unit 210 may be red, blue, and green, respectively. By arranging multiple LED units with different light emitting colors, the range of display colors of the Micro-LED display chip can be widened, and the application range of the Micro-LED display chip can be widened.

[0067] See FIG. 3h. In some embodiments, the third filling structure 520 further includes a third columnar conductor 521 disposed therein, the third filling structure 520 penetrating the third filling structure 520, and the method for manufacturing a Micro-LED display chip further includes disposing a common electrode 600 on the third LED layer, wherein the first LED unit 210 is electrically connected to the common electrode 600 via the second columnar conductor 421 and the third columnar conductor 521 disposed thereon, the second LED unit 410 is electrically connected to the common electrode 600 via the third columnar conductor 521 disposed thereon, and the third LED unit 510 is electrically connected to the common electrode 600. The third LED unit 510 is electrically connected to the common electrode 600 via a second doped semiconductor layer. The third LED unit 510, the second LED unit 410, and the first LED unit 210 are each independently driven. The common electrode 600 may be made of a transparent conductive material. The common electrode 600 is formed by a deposition process. By disposing the common electrode 600 on the surface of the third LED layer 500 opposite to the driving substrate 300, the flatness of the common electrode 600, the stability of electrical connection, and the yield are improved.

[0068] An embodiment of the present specification provides a Micro-LED display chip, which includes a driving substrate 300 including a driving circuit and a contact 310 electrically connected to the driving circuit, a first LED layer 200 disposed on the driving substrate 300, and a second LED layer 400 disposed on the first LED layer 200, wherein the first LED layer 200 includes a plurality of first LED units 210, a first filling structure 220 positioned between the first LED units 210, and a first columnar conductor penetrating the first filling structure 220. The first LED unit 210 and the first columnar conductor 221 are each electrically connected to a contact 310, the second LED layer 400 includes a plurality of second LED units 410 and a second filling structure 420 located between the second LED units 410, the second LED units 410 are electrically connected to the first columnar conductor 221 directly below them, and the second LED units 410 and the first LED units 210 have different emission colors.

[0069] 6. In some embodiments, the first LED layer 200 includes a plurality of spaced-apart first LED units 210, each including a first doped semiconductor layer 211, an active layer 212, and a second doped semiconductor layer 213, wherein the first doped semiconductor layer 211, the active layer 212, and the second doped semiconductor layer 213 of the plurality of first LED units 210 are all spaced apart from one another. The first doped semiconductor layer 211, the active layer 212, and the second doped semiconductor layer 213 are stacked, and the active layer 212 is located between the first doped semiconductor layer 211 and the second doped semiconductor layer 213, such that the second doped semiconductor layer 213 is located on the opposite side of the first doped semiconductor layer 211 from the driving substrate 300. In some embodiments, the first columnar conductor 221 directly below the second LED unit 410 is located such that an orthogonal projection of the first columnar conductor 221 onto the second LED unit 410 is located within the first doped semiconductor layer of the second LED unit 410. The first columnar conductor 221 directly below the second LED unit 410 is connected to the first doped semiconductor layer of the second LED unit 410, and the second LED unit 410 is electrically connected to the contact 310 via the first columnar conductor 221.

[0070] In some embodiments, the first LED unit 210 is electrically connected to the contact 310 of the driving substrate 300. See Figure 6. The first pillar-shaped conductor 221 may not be disposed between the first LED unit 210 and the driving substrate 300.

[0071] 6 and 2c. In some embodiments, the first LED layer 200 includes a first filling structure 220 positioned between the first LED units 210. The first filling structure 220 is used to form a first flat surface on the first LED layer 200. The first LED units 210 are spaced apart, and height differences are formed between the first LED units 210. The first filling structures 220 are positioned between at least a plurality of the first LED units 210 in the circumferential direction around the first LED units 210, reducing or eliminating the height differences between the first LED units 210, improving the flatness of the entire micro-LED display chip, and improving the stability of the micro-LED display chip structure.

[0072] See Figure 6. In some embodiments, the first filling structure 220 is located in the circumferential direction of the first LED unit 210. The first filling structure 220 is located in the circumferential direction of the first LED unit 210, for example, the first filling structure 220 is located between the first LED units 210 and on the side of the first LED unit 210.

[0073] 7. In some embodiments, the first LED unit 210 is embedded in the first filling structure 220. Meanwhile, the first filling structure 220 is positioned in the circumferential direction of the first LED unit 210 and covers the surface of the first doped semiconductor layer 211 of the first LED unit 210 that is close to the base 300. The first LED unit 210 is embedded in the structure of the first filling structure 220. This reduces the difficulty of manufacturing the first filling structure 220 and improves manufacturing efficiency.

[0074] 7 , in some embodiments, when the first LED unit 210 is embedded in the first filling structure 220, a first columnar conductor 221 is disposed directly below the first LED unit 210, penetrating the first filling structure 220, and the first columnar conductor 221 is electrically connected to the first doped semiconductor layer 211 of the first LED unit 210 and the contact 310.

[0075] In some embodiments, the first columnar conductor 221 directly below the first LED unit 210 contacts the surface of the first doped semiconductor layer 211 of the first LED unit 210 opposite the second doped semiconductor layer 213 of the first LED unit 210.

[0076] See Figure 6 or Figure 7. In some embodiments, the first filling structure 220 has a first columnar conductor 221 disposed therein, penetrating the first filling structure 220, spaced apart from the first columnar conductor 221 and the first LED unit 210, and used for electrical connection with the second LED unit 410.

[0077] In some embodiments, the second LED layer 400 is disposed on the side of the first LED layer 200 opposite the driving substrate 300, and in the second LED layer, at least the second filling structure 420 contacts the first LED layer 200, or the second filling structure 420 and the first doped semiconductor layer 211 of the first LED unit 210 contact the first LED layer 200.

[0078] See Figure 6. In some embodiments, the second filling structure 420 is positioned circumferentially around the second LED unit 410. The second filling structure 420 is positioned circumferentially around the second LED unit 410, for example, the second filling structure 420 is positioned between the second LED units 410 and on the side of the second LED unit 410.

[0079] See Fig. 7. In some embodiments, the second LED unit 410 is embedded in a second filling structure 420. Specifically, the second filling structure 420 is positioned in the circumferential direction of the second LED unit 410 and covers the surface of the second LED unit 410 that is close to the first LED unit 210. This reduces the difficulty of manufacturing the second filling structure 420 and improves manufacturing efficiency.

[0080] 7 , in some embodiments, when the second LED unit 410 is embedded in the second filling structure 420, a second columnar conductor 421 penetrating the second filling structure 420 is further disposed directly below the second filling structure 420, and the second columnar conductor 421 is electrically connected to the first doped semiconductor layer of the second LED unit 410 and the first columnar conductor 221.

[0081] In some embodiments, the second pillar-shaped conductor 421 directly below the second filling structure 420 contacts the surface of the first doped semiconductor layer of the second LED unit 410 that is closest to the first LED unit 210.

[0082] In some embodiments, the second filling structure 420 has a second columnar conductor 421 disposed therein that penetrates the second filling structure 420, spacing the second columnar conductor 421 and the second LED unit 410, and is used for electrical connection with the first LED unit 210.

[0083] In some embodiments, the second LED unit 410 emits a different color light than the first LED unit 210. The first LED unit 210 and the first columnar conductor 221 are electrically connected to the contact 310, and the second LED unit 410 is electrically connected to the first columnar conductor 221 directly below it. The first LED unit 210 and the second LED unit 410 are driven independently, enabling multi-color display of the micro-LED display chip and expanding the application range of the micro-LED display chip. The multiple second LED units 410 are omitted here, as they can be referenced to the multiple first LED units 210 spaced apart.

[0084] In the Micro-LED display chip according to the embodiment of the present specification, the first LED unit 210 and the second LED unit 410 with different emission colors are arranged on the first LED layer 200 and the second LED layer 400, respectively, and multi-color display is realized without a wavelength conversion layer. However, since the LED units of the Micro-LED display chip are small in size, the wavelength conversion layer has the disadvantage of being difficult to manufacture and having low conversion efficiency. Therefore, by arranging the first LED unit 210 and the second LED unit 410 with different emission colors, the manufacturing difficulty is reduced and the luminous efficiency and yield are improved. In addition, the first filling structure 220 and the second filling structure 420 are arranged to protect the first LED unit 210 and the second LED unit 410, and to improve the flatness between the film layers and the stability of the Micro-LED display chip structure.

[0085] 8. In some embodiments, the second filling structure 420 has a second pillar-shaped conductor 421 disposed therein, and the Micro-LED display chip further includes a third LED layer 500 disposed on the second LED layer 400, wherein the third LED layer 500 includes a plurality of third LED units 510 and third filling structures 520 disposed between the third LED units 510, and the third LED units 510 are electrically connected to the contacts 310 via the first pillar-shaped conductors 221 and second pillar-shaped conductors 421 directly below the third LED units 510, and the third LED units 510, the second LED units 410, and the first LED units 210 all have different light emission colors.

[0086] See Figure 8. In some embodiments, the first conductor pillars 221, the second conductor pillars 421, and the third conductor pillars 521 may be made of the same material, such as a transparent conductive material or a metal.

[0087] In some embodiments, the third LED layer 500 includes a plurality of spaced-apart third LED units 510. Each third LED unit 510 includes a first doped semiconductor layer, an active layer, and a second doped semiconductor layer, whereas the first doped semiconductor layer, the active layer, and the second doped semiconductor layer of each of the plurality of third LED units 510 are spaced apart from one another. It can be seen that the first doped semiconductor layer, the active layer, and the second doped semiconductor layer are stacked, and the active layer is located between the first doped semiconductor layer and the second doped semiconductor layer, and the second doped semiconductor layer of each of the third LED units 510 is located on the side of the first doped semiconductor layer of each of the third LED units 510 opposite the driving substrate 300. The first doped semiconductor layer of each of the third LED units 510 is electrically connected to the second columnar conductor 421 and the first columnar conductor 221 directly below it. The third LED unit 510 and the contact point 310 are electrically connected.

[0088] In some embodiments, the third LED layer 500 further includes a third packing structure 520. The third packing structure 520 is used to form the plurality of third LED units 510 on a third flat surface in the third LED layer 500. The third packing structure 520 is positioned in the circumferential direction of the third LED unit 510. The third packing structure 520 is positioned in the circumferential direction of the third LED unit 510, for example, the third packing structure 520 is positioned between the third LED units 510 on a side of the third LED unit 510 as the center.

[0089] In some embodiments, the third LED unit 510 is embedded in a third filling structure 520. Specifically, the third filling structure 520 is located in the circumferential direction of the first LED unit 210 and covers the surface of the first doped semiconductor layer of the third LED unit 510 that is close to the second LED unit 410. The third filling structure 520 reduces the difficulty of manufacturing and improves manufacturing efficiency.

[0090] 8. In some embodiments, when the third LED unit 510 is embedded in the third filling structure 520, a third columnar conductor 521 penetrating the third filling structure 520 is disposed directly below the third LED unit 510, and the third columnar conductor 521 and the first doped semiconductor of the third LED unit 510 are electrically connected. The third LED unit 510 is electrically connected to the contact 310 via the third columnar conductor 521, the second columnar conductor 421, and the first columnar conductor 221 directly below it.

[0091] In some embodiments, the third pillar-shaped conductor 521 directly below the third LED unit 510 contacts the surface of the first doped semiconductor layer that is closest to the second LED unit 410 .

[0092] In some embodiments, the third filling structure 520 further includes third columnar conductors 521 that penetrate the third filling structure 520. The third filling structure 520 includes third columnar conductors 521 located between the third LED units 510 and used for electrically connecting the second LED unit 410 or the first LED unit 210 to the common electrode. The third filling structure 520 includes third columnar conductors 521 located directly below the third LED units 510 and used for electrically connecting the third LED units 510 to the contacts 310.

[0093] In some embodiments, the Micro-LED display chip further includes a common electrode 600 disposed on the third LED layer 500, wherein the first LED unit 210 is electrically connected to the common electrode 600 via the second pillar conductor 421 and the third pillar conductor 521 directly above it, the second LED unit 410 is electrically connected to the common electrode 600 via the third pillar conductor 521 directly above it, and the third LED unit 510 is electrically connected to the common electrode 600.

[0094] In some embodiments, the light emitting color of the first LED unit 210, the light emitting color of the second LED unit 410, and the light emitting color of the third LED unit 510 are each selected from red, green, and blue. The light emitting color of the first LED unit 210, the light emitting color of the second LED unit 410, and the light emitting color of the third LED unit 510 are different from each other, which is advantageous for realizing a full-color display. In some embodiments, the light emitting color of the first LED unit 210, the light emitting color of the second LED unit 410, and the light emitting color of the third LED unit 510 are selected from any color, such as purple or yellow, which broadens the application range of Micro-LED display chips.

[0095] In some embodiments, the Micro-LED display chip is divided into a plurality of pixel units arranged in an array, and each pixel unit includes at least one first LED unit 210, at least one second LED unit 410, and at least one third LED unit 510, where the number of first LED units 210, the number of second LED units 410, and the number of third LED units 510 included in each pixel unit are not identical. See Figure 9. One pixel unit shown in the dashed-line frame in Figure 9 includes two first LED units 210, one second LED unit 410, and one third LED unit 510.

[0096] In some embodiments, the light emitting colors of the first LED unit 210, the second LED unit 410, and the third LED unit 510 are red, green, and blue, respectively, and in one pixel unit, the number of second LED units 410 is greater than the number of first LED units 210, and the number of second LED units 410 is greater than the number of third LED units 510, and one pixel is constructed from the number of first LED units, second LED units, and third LED units, thereby providing a method for forming multiple single pixels.

[0097] In an embodiment of the present specification, a display panel is provided, and the display panel includes any of the above-mentioned Micro-LED display chips.

[0098] In this embodiment, the display panel includes any of the above-mentioned Micro-LED display chips, and the display color range of the Micro-LED display chip is increased, so the display color range of the display panel and the application range of the display panel are increased.

[0099] In an embodiment of the present specification, a display device is provided, which includes any of the above-mentioned Micro-LED display chips.

[0100] In this embodiment, the display device includes any of the above-mentioned Micro-LED display chips, and the display color range of the Micro-LED display chip is increased, and the display color range of the display device is increased, thereby increasing the application range of the display device.

[0101] The present specification emphasizes the differences between the various embodiments and other embodiments, and each embodiment should be interpreted in light of the other embodiments. Any combination of the various embodiments in the present specification made by a person skilled in the art based on common technical knowledge is also included in the scope of the present specification.

[0102] The technical features of the above embodiments may be combined in any desired manner. For the sake of convenience, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combinations of these technical features, they should all be considered within the scope of this specification.

[0103] The above description is merely a partial embodiment of the present specification, and does not limit the present specification, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present specification should be included within the disclosure scope of the present specification.

Claims

1. A method for manufacturing a Micro-LED display chip, comprising: A driving substrate including a driving circuit and a contact electrically connected to the driving circuit; a plurality of first LED units; and a first filling structure positioned between the first LED units; a first LED layer including a first columnar conductor penetrating the first filling structure; and electrically connecting the first LED unit and the first columnar conductor to the contacts, respectively. bonding the first LED layer and the driving substrate together so that a second LED layer including a plurality of second LED units and a second filling structure located between the second LED units, electrically connecting the second LED units to the first columnar conductor directly below the second LED units, and arranging the second LED layer on the first LED layer so that the second LED units and the first LED units have different emission colors.

2. The step of forming the first LED unit includes: providing a first LED epitaxial layer including a doped semiconductor layer and an active layer; and etching the first LED epitaxial layer to form a plurality of the first LED units; The step of forming the second LED units includes: providing a second LED epitaxial layer including a doped semiconductor layer and an active layer; and etching the second LED epitaxial layer to form a plurality of the second LED units; The method for manufacturing a Micro-LED display chip according to claim 1, characterized in that the active layer of the second LED epitaxial layer and the active layer of the first LED epitaxial layer are arranged differently, thereby realizing that the second LED unit and the first LED unit have different emission colors.

3. In the step of providing a first LED layer, providing a first LED epitaxial layer; Etching the first LED epitaxial layer to form a plurality of first LED units, each of the first LED units including a first doped semiconductor layer, an active layer and a second doped semiconductor layer, and the second doped semiconductor layers of adjacent first LED units are connected to each other; disposing the first filling structure between the first LED units; and disposing the first pillar-shaped conductors penetrating the first filling structures.

4. Before the step of disposing the second LED layer on the first LED layer, 4. The method for manufacturing a Micro-LED display chip according to claim 3, further comprising: thinning the second doped semiconductor layer of the first LED unit until the tip of the first columnar conductor is exposed, and the first LED units are spaced apart from each other after thinning.

5. In the step of providing a first LED layer, providing a first LED epitaxial layer; Etching the first LED epitaxial layer to form a plurality of spaced-apart first LED units, each of the first LED units including a first doped semiconductor layer, an active layer, and a second doped semiconductor layer; disposing the first filling structure between the first LED units; and disposing the first pillar-shaped conductors penetrating the first filling structures.

6. In the first LED layer, the first filling structure covers the first LED unit; In contrast, in the step of arranging the first columnar conductors penetrating the first filling structure, 2. The method for manufacturing a Micro-LED display chip according to claim 1, further comprising: disposing a first columnar conductor on the first LED unit; and electrically connecting the first LED unit to the contact point through the corresponding first columnar conductor.

7. The first filling structure covers the first LED unit, The first filling structure is positioned in the circumferential direction of the first LED unit and covers a surface of the first doped type semiconductor layer of the first LED unit opposite to the second doped type semiconductor layer of the first LED unit; or 7. The method for manufacturing a micro-LED display chip according to claim 6, wherein the first filling structure is located between a plurality of first LED units spaced apart from each other and covers the first LED units.

8. In the step of disposing a second LED layer on the first LED layer, providing a second LED layer including a plurality of second LED units and a second filling structure positioned between the second LED units; The method for manufacturing a Micro-LED display chip according to claim 1 further comprises bonding the second LED layer and the first LED layer so that the second LED unit is electrically connected to the first columnar conductor directly below it, thereby achieving electrical connection with the contact.

9. The second filling structure further includes a second columnar conductor penetrating the second filling structure, and the second columnar conductor is electrically connected to the first columnar conductor directly below the second columnar conductor. The manufacturing method for the Micro-LED display chip further includes:

2. The method for manufacturing a Micro-LED display chip according to claim 1, further comprising: disposing a third LED layer on the second LED layer, wherein the third LED layer comprises a plurality of third LED units and third filling structures located between the third LED units, the third LED units being electrically connected to the contacts via the first and second columnar conductors directly below the third LED units, and the third LED units, the second LED units, and the first LED units having different emission colors.

10. The third filling structure further includes a third columnar conductor penetrating the third filling structure, and the manufacturing method of the Micro-LED display chip further comprises:

10. The method for manufacturing a Micro-LED display chip according to claim 9, further comprising disposing a common electrode on the third LED layer, wherein the first LED unit is electrically connected to the common electrode via the second columnar conductor and the third columnar conductor directly above it, the second LED unit is electrically connected to the common electrode via the third columnar conductor directly above it, and the third LED unit is electrically connected to the common electrode.

11. A Micro-LED display chip, a drive substrate including a drive circuit and a contact electrically connected to the drive circuit; a first LED layer disposed on the driving substrate, the first LED layer including a plurality of first LED units, a first filling structure located between the first LED units, and a first columnar conductor penetrating the first filling structure; a plurality of second LED units, and a second filling structure located between the second LED units, the second LED units being electrically connected to the first columnar conductor directly below the second LED units; and a second LED layer disposed on the first LED layer so that the light emitted from the second LED units differs from the light emitted from the first LED units; the first LED units being embedded in the first filling structure, and the first LED units being electrically connected to the contacts via the first columnar conductor directly below the first LED units.

12. the first LED unit is formed by etching a first LED epitaxial layer, the first LED epitaxial layer including a doped semiconductor layer and an active layer; the second LED unit is formed by etching a second LED epitaxial layer, the second LED epitaxial layer including a doped semiconductor layer and an active layer; The micro-LED display chip of claim 11, wherein the active layer of the second LED epitaxial layer and the active layer of the first LED epitaxial layer are different, thereby realizing the second LED unit and the first LED unit having different emission colors.

13. The first LED layer, wherein the first filling structure covers the first LED unit, and wherein: The first filling structure is located in the circumferential direction of the first LED unit and covers a surface of the first doped semiconductor layer of the first LED unit opposite to the second doped semiconductor layer of the first LED unit; or The micro-LED display chip according to claim 11, wherein the first filling structure is located between a plurality of first LED units spaced apart from each other and covers the first LED units.

14. The second filling structure further includes a second columnar conductor disposed therein and penetrating the second filling structure; 12. The micro-LED display chip according to claim 11, further comprising: a third LED layer disposed on the second LED layer, wherein the third LED layer comprises a plurality of third LED units and third filling structures located between the third LED units, the third LED units electrically connecting with the contacts through the first pillar-shaped conductors and the second pillar-shaped conductors directly below the third LED units, and the light emitting colors of the third LED units, the second LED units and the first LED units are different from each other.

15. 15. The micro-LED display chip of claim 14, wherein the third filling structure further includes a third columnar conductor penetrating the third filling structure, and the micro-LED display chip further includes a common electrode disposed on the third LED layer, wherein the first LED unit is electrically connected to the common electrode via the second columnar conductor and the third columnar conductor directly above it, the second LED unit is electrically connected to the common electrode via the third columnar conductor directly above it, and the third LED unit is electrically connected to the common electrode.

16. 15. The Micro-LED display chip of claim 14, wherein the Micro-LED display chip is divided into a plurality of pixel units arranged in an array, and each pixel unit includes at least one of the first LED unit, at least one of the second LED unit, and at least one of the third LED unit, and wherein the numbers of the first LED unit, the second LED unit, and the third LED unit included in each pixel unit are not all the same.

17. 15. The micro-LED display chip according to claim 14, wherein the light emitting color of the first LED unit, the light emitting color of the second LED unit, and the light emitting color of the third LED unit are selected from red, green, and blue, respectively.

18. The Micro-LED display chip described in Claim 14, characterized in that the second LED unit is embedded in the second filling structure, and the second LED unit realizes electrical connection with the contact via the second columnar conductor and the first columnar conductor directly below it.

Images