CN119730483A

CN119730483A - LED chip assembly, manufacturing method thereof and LED chip stripping method

Info

Publication number: CN119730483A
Application number: CN202311245560.9A
Authority: CN
Inventors: 王子川; 戴广超; 马非凡; 陈德伪; 马振琦
Original assignee: Chongqing Kangjia Optoelectronic Technology Co ltd
Current assignee: Chongqing Kangjia Optoelectronic Technology Co ltd
Priority date: 2023-09-25
Filing date: 2023-09-25
Publication date: 2025-03-28

Abstract

The invention relates to an LED chip assembly, a manufacturing method thereof and an LED chip stripping method. The manufacturing method of the LED chip assembly comprises the steps of providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate, a sacrificial layer and a functional layer, the sacrificial layer and the functional layer are sequentially laminated on the substrate, the sacrificial layer can be decomposed by illumination, the functional layer is patterned to form a plurality of LED epitaxial structures on the substrate, channels between adjacent LED epitaxial structures expose the sacrificial layer, a passivation layer is deposited on the epitaxial wafer, the passivation layer at least covers the LED epitaxial structures, electrode holes are formed in the passivation layer, and electrodes are evaporated in the electrode holes to enable the electrodes to be connected with the LED epitaxial structures. Through this scheme, can effectively reduce MicroLED when the laser is peeled off, microLED peels off and drops and produces passivation layer piece.

Description

LED chip assembly, manufacturing method thereof and LED chip stripping method

Technical Field

The invention relates to the technical field of LED chips, in particular to an LED chip assembly, a manufacturing method thereof and an LED chip stripping method.

Background

Micro-LEDs refer to Micro-LEDs or Mini-LEDs, which are reduced in size from millimeter to Micro-nanometer compared with conventional LEDs, and when integrated into high-density, small-sized arrays and applied to the display field, have the advantages of high brightness, high resolution, high contrast, low energy consumption, long service life and the like, and simultaneously have excellent performance in the aspects of response speed, thermal stability and the like.

The manufacturing MicroLED of the array firstly requires that semiconductor materials are grown on a substrate such as sapphire, monocrystalline gallium nitride, silicon carbide, gallium arsenide and the like, independent light-emitting units are formed through a semiconductor process, and then the independent light-emitting units are peeled off from the substrate and then transferred to a proper transfer substrate. Among them, the light emitting unit is peeled off from the substrate mainly by chemical peeling, mechanical peeling, thermal peeling, laser peeling, and the like. The laser stripping technology mainly utilizes the characteristics that the semiconductor material and the substrate have different absorption to laser and part of the semiconductor material can be decomposed after the laser is absorbed to realize the stripping purpose. Compared with other modes, the laser stripping technology has the characteristics of high efficiency, no pollution, small device damage, high yield and the like, so that the requirements of industrial production can be better met.

However, during the process of peeling MicroLED from the substrate, microLED peel-off followed by passivation layer chipping is typically encountered, affecting subsequent process yields.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present application is directed to an LED chip assembly, a method for manufacturing the same, and a method for peeling an LED chip, which are intended to solve the problem that passivation layer chips are left after MicroLED is peeled off during MicroLED laser peeling, which affects the yield of subsequent processes.

In a first aspect, the present application provides a method for manufacturing an LED chip assembly, including:

Providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate, and a sacrificial layer and a functional layer which are sequentially laminated on the substrate, and the sacrificial layer can be decomposed by illumination;

patterning the functional layer to form a plurality of LED epitaxial structures on the substrate such that channels between adjacent LED epitaxial structures expose the sacrificial layer, and

Depositing a passivation layer on the epitaxial wafer to enable the passivation layer to at least cover the LED epitaxial structure;

And an electrode hole is formed in the passivation layer, and an electrode is evaporated in the electrode hole, so that the electrode is connected with the LED epitaxial structure.

In the embodiment of the application, when the patterning functional layers (namely the main layer structure forming the LED epitaxy at least comprises an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer) form a plurality of LED epitaxy structures, the sacrificial layers on the channels between the adjacent LED epitaxy structures are reserved, so that when the LED chips in the LED chip assembly are peeled off later, the sacrificial layers on the channels between the adjacent LED epitaxy structures are decomposed, so that at least part of passivation layers and the substrate are suspended, the passivation layers on the LED chips are broken through shearing force when the LED chips are separated from the substrate, and the problem that passivation layer fragments appear when the LED chips are separated from the substrate due to the fact that the passivation layers are directly connected with the substrate in a traditional mode is solved.

In an alternative embodiment, after said patterning of said functional layer, said method further comprises:

and thinning the sacrificial layer exposed by the channel to enable the thickness of the sacrificial layer exposed by the channel to be 0.1-2um.

In the embodiment of the application, if the thickness of the sacrificial layer exposed by the channel is greater than a certain threshold value, when the LED chip is peeled off, the LED chip is connected with the thicker sacrificial layer on the channel after photodecomposition of the sacrificial layer connected with the substrate, so that the LED chip is difficult to separate from the substrate. Therefore, in the embodiment of the application, the thickness of the sacrificial layer exposed by the channel needs to be controlled so as to improve the peeling efficiency of the LED chip. According to the application, a large amount of experimental experience shows that the thickness of the sacrificial layer on the channel is kept at 0.1-2um, so that the stripping efficiency of the LED chip can be effectively improved.

In an alternative embodiment, the passivation layer covers only the surface of the LED epitaxial structure.

In the embodiment of the application, after the passivation layer is deposited, the passivation layer on the channel between the adjacent LED epitaxial structures can be removed in an etching manner, so that the passivation layer only covers the surface of the LED epitaxial structures. Thus, only the sacrificial layer is connected with the substrate on the channel, and the LED chip is not affected by the passivation layer when being stripped. It is understood that the passivation layer on the trench may be removed by other methods, and the removing method is not limited by the embodiment of the present application.

In an alternative embodiment, the passivation layer covers the surface of the LED epitaxial structure and the sacrificial layer exposed over the channel.

In the embodiment of the application, after the passivation layer is deposited, the passivation layer on the channel is not treated, and when the LED chip is stripped, the part of the sacrificial layer, which is close to the LED chip, on the channel can be decomposed, so that the passivation layer and the substrate are suspended, and when the LED chip is separated from the substrate, the passivation layer can be broken through shearing force, thereby reducing the probability of fragments of the passivation layer. In addition, in this embodiment, after the passivation layer is deposited, the passivation layer on the channel is not processed, so that a process can be reduced, and thus, the manufacturing cost can be reduced.

In an alternative embodiment, the material of the sacrificial layer includes one or more of gallium nitride, BCB glue, silicon carbide.

In a second aspect, based on the same inventive concept, the present application also provides an LED chip assembly, comprising:

a substrate;

A sacrificial layer laminated on the substrate;

a plurality of LED epitaxial structures are arranged on the sacrificial layer at intervals;

the surface of each LED epitaxial structure is covered with a passivation layer;

the passivation layer is provided with an electrode hole, an electrode is arranged in the electrode hole, and the electrode is connected with the LED epitaxial structure.

In the embodiment of the application, the sacrificial layer is arranged on the channel between the adjacent LED epitaxial structures, so that the sacrificial layer on the channel between the adjacent LED epitaxial structures is decomposed when the LED chips in the LED chip assembly are stripped later, so that at least part of passivation layers and the substrate are suspended, the passivation layers on the LED chips are broken through shearing force when the LED chips are separated from the substrate, and the problem that the passivation layers are broken through shearing force when the LED chips are separated from the substrate is solved.

In an alternative embodiment, the thickness of the sacrificial layer on the channel between adjacent LED epitaxial structures is 0.1-2um.

In an alternative embodiment, the passivation layer also covers a sacrificial layer on the channel.

In a third aspect, based on the same inventive concept, the present application further provides an LED chip peeling method, including:

providing the LED chip assembly of the first or second aspect, wherein the LED epitaxial structure of the LED chip assembly, the passivation layer on the LED epitaxial structure, and the electrode connected to the LED epitaxial structure constitute the LED chip;

providing a substrate;

arranging the LED chip assembly corresponding to the substrate;

Irradiating the sacrificial layer with laser light, the sacrificial layer decomposing to transfer the irradiated LED chips on the LED chip assembly to the substrate;

the light spot area is larger than the projection area of the LED chip on the sacrificial layer, and the light spot area is the coverage area of the light spot irradiated by the laser on the sacrificial layer.

In the embodiment of the application, the sacrificial layer on the channel between the adjacent LED epitaxial structures is reserved. When the LED chips in the LED chip assembly are stripped by laser, the irradiation area of light spots irradiated by the laser is larger than the projection area of the LED chips on the sacrificial layer, so that at least part of the sacrificial layer on a channel between adjacent LED epitaxial structures can be decomposed, at least part of the passivation layer is suspended from the substrate, and the passivation layer on the LED chips is broken with the substrate by shearing force when the LED chips are separated from the substrate. The probability that the laser stripped LED chip is broken in the passivation layer can be effectively reduced.

Drawings

Fig. 1 is a schematic diagram of a conventional laser-stripped LED chip;

fig. 2 is a schematic flow chart of a method for manufacturing an LED chip assembly according to an embodiment of the present application;

Fig. 3 is a schematic structural diagram of a functional layer patterning process in the method for manufacturing an LED chip assembly according to an embodiment of the present application;

Fig. 4 is a schematic structural diagram of a thinned sacrificial layer in the method for manufacturing an LED chip assembly according to the embodiment of the present application;

Fig. 5 is a schematic structural diagram of an LED chip assembly according to an embodiment of the present application after a passivation layer is deposited;

Fig. 6 is a schematic structural diagram of another method for manufacturing an LED chip assembly according to an embodiment of the present application after depositing a passivation layer;

Fig. 7 is a schematic structural diagram of an LED chip assembly according to an embodiment of the present application;

Fig. 8 is a schematic structural diagram of another LED chip assembly according to an embodiment of the present application

Fig. 9 is a schematic structural diagram of another LED chip assembly according to an embodiment of the present application

FIG. 10 is a schematic flow chart of a method for stripping an LED chip;

Fig. 11 is a schematic diagram of a process structure in an LED chip peeling method according to an embodiment of the present application.

Reference numerals illustrate:

10-substrate, 20-functional layer, 21-LED epitaxial structure, 30-passivation layer, 31-passivation layer debris, 40-electrode, 50-sacrificial layer, 60-substrate.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to fall within the scope of the invention.

The disclosure of the present invention provides many different embodiments or examples for implementing different structures of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described herein. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Generally, the terminology may be understood, at least in part, in accordance with the usage of the application. For example, the term "one or more" as used herein depends at least in part on the application and may be used to describe any component, structure or feature in the singular or may be used to describe any combination of components, structures or features in the plural. Similarly, terms such as "a," "an," or "the" may also be construed to convey a singular usage or a plural usage depending, at least in part, on the application above. In addition, the term "based on" may be understood as not necessarily intended to convey an exclusive set of factors, but rather as may be dependent, at least in part, upon the above that the application may instead allow for the presence of additional factors that are not necessarily explicitly described.

It should be readily understood that the meanings of "on," "over," and "above" in the present invention should be interpreted in the broadest sense so that "on" means not only "directly on" but also "on" including an intermediate member or layer that exists therebetween, and "on" or "over" means not only "on" or "over" but also the meaning of "on" or "over" without an intermediate member or layer therebetween.

Furthermore, spatially relative terms, such as "below," "under," "lower," "above," "upper," and the like, may be used herein for ease of description to describe one element or component's relationship to another element or component as illustrated in the figures. In addition to the orientations depicted in the drawings, the spatially relative terms are intended to encompass different orientations of the device in use or operation. The device may be rotated 90 deg. in other orientations or in other orientations and the spatially relative descriptors used in the present invention may be interpreted accordingly as such.

The term "layer" as used in the present invention refers to a portion of material comprising regions having a certain thickness. The layers may extend over the entire underlying or overlying structure, or may have a degree less than the extent of the underlying or overlying structure. Furthermore, the layer may be a region of homogeneous or heterogeneous continuous structure having a thickness less than the thickness of the continuous structure. For example, the layer may be located between the top and bottom surfaces of the continuous structure or between any pair of horizontal planes therebetween. The layers may extend horizontally, vertically and/or along a tapered surface. The substrate may be a layer, may include one or more layers therein, and/or may have one or more layers thereon, and/or thereon. One layer may comprise multiple layers. For example, the semiconductor layer may include one or more doped or undoped semiconductor layers, and may have the same or different materials.

Referring to fig. 1, a schematic diagram of a conventional laser lift-off LED chip is shown. As shown, the LED chip includes an LED epitaxial structure 21, a passivation layer 30, and electrodes 40, the LED chip being disposed on a substrate. In order to fully cover the side wall of the LED chip by the passivation layer and solve the problem of etching equipment precision when manufacturing the LED chip, the passivation layer on the channel is partially etched after the passivation layer is deposited, so that the passivation layer on the part of the channel close to the side wall of the LED is directly covered on the substrate. When the LED chip is stripped by laser, after gallium nitride (sacrificial layer) on the contact surface of the LED epitaxial structure and the substrate is decomposed by the laser, impact force is generated on the LED chip, so that the LED chip is separated from the substrate. In this process, since the passivation layer on the portion of the channel near the side wall of the LED is directly covered on the substrate, a pulling force is generated between the passivation layer on the LED chip and the passivation layer covered on the substrate, resulting in the passivation layer being partially broken to generate passivation layer chipping 31. The drop of passivation layer debris 31 can affect subsequent process yields. In addition, the phenomenon of breaking the LED chip can also occur due to the influence of the pulling force between the passivation layer around the side wall of the LED chip and the substrate.

Based on this, the present application is intended to provide a solution to the above technical problem, the details of which will be described in the following examples.

Referring to fig. 2, a flow chart of a method for manufacturing an LED chip assembly according to an embodiment of the present application is provided, where the method includes:

And 101, providing an epitaxial wafer, wherein the epitaxial wafer comprises a substrate, and a sacrificial layer and a functional layer which are sequentially laminated on the substrate, and the sacrificial layer can be decomposed by illumination.

In the embodiment of the application, the functional layer is a main epitaxial layer structure of the LED, and the functional layer may include an active layer and a second semiconductor layer of a first semiconductor layer sequentially stacked on the sacrificial layer, where the first semiconductor layer and the second semiconductor layer are doped semiconductor layers of different types.

The first semiconductor layer may be an N-doped semiconductor layer or a P-doped semiconductor layer, and the second semiconductor layer may be a P-doped semiconductor layer or an N-doped semiconductor layer. The active layer may be a multiple quantum well structure (Multiple Quantum Well, MQW). Specifically, the semiconductor layer may be a group III-V compound semiconductor material such as GaN, alGaN, inGaN, alInP, gaInP, alGaInP, the quantum well or quantum layer may be InGaN, alGaN, inN, inAlN, alInGaN, and the quantum barrier alternately stacked with the quantum well layer may be GaN, alN, alGaN, alInGaN, inAlN, or the like, the multiple quantum well structure may include one or two or three or four or five or six or seven or eight quantum wells (or at least one quantum hole), and the wavelength emitted by the active layer may be a wavelength of blue light band, a wavelength of green light band, or a wavelength of red light band.

In the embodiment of the application, the sacrificial layer is made of a material which can be decomposed by light irradiation so as to separate the functional layer from the substrate, and for example, the material of the sacrificial layer comprises one or more of gallium nitride, BCB (binary coded decimal) glue, shellac, silicon carbide and the like.

In the embodiment of the application, the substrate may be a growth substrate or a temporary substrate. For example, the epitaxial wafer may be a GaN-based blue-green light epitaxial wafer, the substrate is sapphire, the sacrificial layer is U-shaped GaN, and the functional layer includes an N-type GaN layer, an active layer and a P-type GaN layer stacked in order. For another example, the epitaxial wafer may be an indium gallium aluminum phosphide-based red light epitaxial wafer, the substrate may be a temporary substrate sapphire, the sacrificial layer may be BCB glue, gaN, silicon carbide, or the like, and the functional layer may include a P-type AlInP (or AlGaInP) layer, an active layer, and an N-type AlInP (or AlGaInP) layer stacked in this order. It is understood that the substrate may be a temporary substrate, regardless of whether the functional layer corresponds to blue-green light or red light, which is not limited by the present application.

And 102, patterning the functional layer to form a plurality of LED epitaxial structures on the substrate, and exposing the sacrificial layer through channels between adjacent LED epitaxial structures.

The patterning refers to forming the layer structure into a predetermined pattern shape through a plurality of photolithography, etching, and the like. After the patterning of the functional layers 20, a plurality of independent LED epitaxial structures 21 are formed, each LED epitaxial structure 21 is separated from the other LED epitaxial structures 21, the original functional layers between the adjacent LED epitaxial structures 21 are removed to form channels, and the sacrificial layers 50 are exposed on the channels, as shown in fig. 3.

The LED epitaxial structure has the same layer structure as the functional layer and comprises an LED main epitaxial layer structure, namely an active layer of a first semiconductor layer and a second semiconductor layer.

In an alternative embodiment, after the patterning of the functional layer, the method further comprises thinning the sacrificial layer exposed by the channel such that the thickness of the sacrificial layer exposed by the channel is 0.1-2um.

In the embodiment of the application, the thickness of the sacrificial layer after the thinning on the channel between the adjacent LED epitaxial structures may be 0.1-0.3um, 0.3-0.5um, 0.5-1um, 1-2um, 0.2-2um or 2-2.5um.

It is understood that the above-mentioned thinning of the sacrificial layer may be performed simultaneously with a part of the process in the patterning of the functional layer, or may be performed separately after the patterning of the functional layer is completed. For example, the sacrificial layer may be etched simultaneously with the channel etching described above when patterning the functional layer. A schematic structure after thinning the sacrificial layer on the channel can be seen in fig. 4.

And 103, depositing a passivation layer on the epitaxial wafer, so that the passivation layer at least covers the LED epitaxial structure.

In an embodiment of the present application, the passivation layer covers a surface of the LED epitaxial structure, and is used for protecting the LED epitaxial structure. The passivation layer can be one or more of Al ₂O₃、AlN、SiN、SiO₂ and AlON films.

In an alternative embodiment, the passivation layer covers the surface of the LED epitaxial structure and the sacrificial layer exposed over the channel, as shown in fig. 5.

In an alternative embodiment, the passivation layer covers only the surface of the LED epitaxial structure, as shown in fig. 6.

And 104, forming an electrode hole on the passivation layer, and evaporating an electrode in the electrode hole to enable the electrode to be connected with the LED epitaxial structure, as shown in figures 7-9.

In an embodiment of the present application, the electrode 40 is one or more metals that can form ohmic contact with the LED epitaxial structure for conducting current, for example, the electrode 40 can be formed as a combination of one or more of Cr, pt, ti, ni, au, sn.

Referring to fig. 7 to 9, based on the same inventive concept, the present application also provides an LED chip assembly, which comprises a substrate 10, a sacrificial layer 50 laminated on the substrate, a plurality of LED epitaxial structures 21 spaced apart on the sacrificial layer, a passivation layer 30 covering the surface of each LED epitaxial structure, and an electrode hole provided on the passivation layer, wherein an electrode 40 is provided in the electrode hole, and the electrode is connected with the LED epitaxial structures.

In an embodiment of the present application, the layer structure of the LED epitaxial structure includes an active layer and a second semiconductor layer of a first semiconductor layer sequentially stacked on the sacrificial layer, where the first semiconductor layer and the second semiconductor layer are doped semiconductor layers of different types.

It is understood that the LED epitaxial structure described above may also include other layer structures, such as current spreading layers, ohmic contact layers, and the like.

In the embodiment of the application, the sacrificial layer on the channel between the adjacent LED epitaxial structures is reserved, so that the sacrificial layer on the channel between the adjacent LED epitaxial structures is decomposed when the LED chips in the LED chip assembly are stripped later, so that at least part of passivation layers and the substrate are suspended, the passivation layers on the LED chips are broken through shearing force when the LED chips are separated from the substrate, and the problem that passivation layer fragments appear due to the fact that the passivation layers are directly connected with the substrate and separated from the substrate through pulling force in the traditional mode is solved.

In an alternative embodiment, as shown in fig. 9, the thickness of the sacrificial layer on the channel between adjacent LED epitaxial structures is set to 0.1-2um.

In the embodiment of the application, the thickness of the sacrificial layer on the channel between the adjacent LED epitaxial structures can be 0.1-0.3um, 0.3-0.5um, 0.5-1um or 1-2um.

In an alternative embodiment, as shown in fig. 7, the passivation layer covers the surface of the LED epitaxial structure and the sacrificial layer over the channel.

In an alternative embodiment, as shown in fig. 8, the passivation layer covers only the surface of the LED epitaxial structure.

Referring to fig. 10, a flow chart of an LED chip peeling method provided by the application is shown, and the method includes:

An LED chip assembly is provided 201.

In an embodiment of the present application, the LED chip assembly is the LED chip assembly described in any one of the foregoing embodiments, wherein the LED epitaxial structure of the LED chip assembly, the passivation layer on the LED epitaxial structure, and the electrode connected to the LED epitaxial structure form the LED chip.

202, Providing a substrate.

In an embodiment of the present application, the substrate includes a temporary substrate or a driving back plate.

And 203, arranging the LED chip assembly corresponding to the substrate.

And 204, irradiating the sacrificial layer by using laser, wherein the sacrificial layer is decomposed so as to transfer the irradiated LED chips on the LED chip assembly to the substrate.

In the embodiment of the application, the sacrificial layer on the channel between the adjacent LED epitaxial structures is reserved. When the LED chips in the LED chip assembly are stripped by laser, the irradiation area of light spots irradiated by the laser is larger than the projection area of the LED chips on the sacrificial layer, so that at least part of the sacrificial layer on a channel between adjacent LED epitaxial structures can be decomposed, at least part of the passivation layer is suspended from the substrate, and the passivation layer on the LED chips is broken with the substrate by shearing force when the LED chips are separated from the substrate. The probability of passivation layer scraps generated when the LED chip is stripped by laser can be effectively reduced.

In an alternative embodiment, the sacrificial layer is irradiated with a laser, the sacrificial layer is decomposed such that before transferring the irradiated LED chips on the LED chip assembly to the substrate, the method further comprises irradiating the sacrificial layer on the channels adjacent to the LED chips with a laser, and at least partially decomposing the sacrificial layer on the channels adjacent to the LED chips. This ensures that the subsequent step of irradiating the sacrificial layer with a laser, which is decomposed such that the irradiated LED chip on the LED chip assembly is transferred to the substrate, is suspended between the sacrificial layer adjacent to the LED chip on the adjacent channel and the substrate, such that the passivation layer and/or the sacrificial layer breaks in a shearing force manner when the LED chip is detached.

Referring to fig. 11, a schematic diagram of a process structure in an LED chip stripping method according to an embodiment of the present application is provided, as shown in the drawing, an LED chip assembly and a substrate described in the foregoing embodiment are provided first, then the substrate and the LED chip assembly are disposed opposite to each other, and then a sacrificial layer (for example, U-shaped GaN) where the stripped LED chip is located is irradiated with laser, where an area of the sacrificial layer irradiated with a spot of the laser is larger than an area of the LED chip projected onto the sacrificial layer, and after the sacrificial layer is irradiated with the laser, N ₂ and metal Ga are decomposed, and the LED chip is separated from the substrate and transferred to the substrate under the generated N ₂ impact force. The sacrificial layer is arranged on the channel between the adjacent LED chips on the LED chip assembly, and the area of the sacrificial layer irradiated by the light spot of the laser during laser stripping is larger than the projected area of the LED chip on the sacrificial layer, so that the sacrificial layer and/or the passivation layer, which are close to the LED chip to be stripped, on the channel are broken due to shearing force when the LED chip is separated from the substrate. Therefore, the generation of passivation layer scraps caused when the LED chip is stripped can be effectively reduced.

It is to be understood that the invention is not limited in its application to the examples described above, but is capable of modification and variation in light of the above teachings by those skilled in the art, and that all such modifications and variations are intended to be included within the scope of the appended claims.

Claims

1. A method for manufacturing an LED chip assembly, comprising:

Providing an epitaxial wafer, the epitaxial wafer comprising a substrate, and a sacrificial layer and a functional layer sequentially stacked on the substrate;

Patterning the functional layer to form a plurality of LED epitaxial structures on the substrate, and allowing the channels between adjacent LED epitaxial structures to expose the sacrificial layer; and

Depositing a passivation layer on the epitaxial wafer so that the passivation layer at least covers the LED epitaxial structure;

An electrode hole is opened on the passivation layer, and an electrode is evaporated in the electrode hole to connect the electrode to the LED epitaxial structure.

2. The method for manufacturing an LED chip assembly according to claim 1, characterized in that after patterning the functional layer, the method further comprises:

The sacrificial layer exposed by the channel is thinned so that the thickness of the sacrificial layer exposed by the channel is 0.1-2 um.

3 . The method for manufacturing an LED chip assembly according to claim 1 , wherein the passivation layer only covers the surface of the LED epitaxial structure.

4 . The method for manufacturing an LED chip assembly according to claim 1 , wherein the passivation layer covers the surface of the LED epitaxial structure and the sacrificial layer exposed on the channel. 5 .

5. The method for manufacturing an LED chip assembly according to any one of claims 1 to 4, characterized in that the material of the sacrificial layer comprises one or more of gallium nitride, BCB glue, and silicon carbide.

6. An LED chip assembly, comprising:

substrate;

a sacrificial layer stacked on the substrate;

The passivation layer is provided with an electrode hole, an electrode is provided in the electrode hole, and the electrode is connected to the LED epitaxial structure.

7 . The LED chip assembly according to claim 6 , wherein the thickness of the sacrificial layer on the channel between adjacent LED epitaxial structures is 0.1-2 um.

8 . The LED chip assembly according to claim 7 , wherein the passivation layer also covers the sacrificial layer on the channel.

9 . The LED chip assembly according to claim 6 , wherein the material of the sacrificial layer comprises one or more of gallium nitride, BCB glue, and silicon carbide.

10. A method for stripping an LED chip, comprising:

Providing an LED chip assembly as described in any one of claims 6 to 8;

providing a substrate;

The LED chip assembly is arranged corresponding to the substrate;

Using laser to irradiate the sacrificial layer, the sacrificial layer is decomposed, so that the irradiated LED chip on the LED chip assembly is transferred to the substrate;

The light spot area is larger than the area projected by the LED chip on the sacrificial layer, and the light spot area is the area covered by the light spot irradiated by the laser on the sacrificial layer.