WO2022230952A1

WO2022230952A1 - Led transfer member and method for manufacturing led device

Info

Publication number: WO2022230952A1
Application number: PCT/JP2022/019137
Authority: WO
Inventors: 一尊本田; 昌貴西田; 元雄青山
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2021-04-27
Filing date: 2022-04-27
Publication date: 2022-11-03
Also published as: TW202310323A

Abstract

This LED transfer member includes, in at least a part of a surface thereof, a region in which tack strength is decreased by optical irradiation, and has a tensile strength at 50℃ of 1 MPa to 10 MPa. The LED transfer member is employed in a method for manufacturing an LED device.

Description

Method for manufacturing LED transfer member and LED device

The present disclosure relates to an LED transfer member and a method for manufacturing an LED device.

Conventionally, image display devices using LEDs (Light Emitting Diodes) have used LED packages (chip LEDs) with a size of about 1 mm or more, in which LED elements are mounted on a substrate by wire bonding. In recent years, from the viewpoint of high pixel density and high response speed for image display devices, a method of mounting mini or micro LED elements on a substrate of an image display device by flip chip has been used.
Micro LED devices are generally fabricated by epitaxial growth on a crystal growth substrate such as sapphire. In order to mount the micro LED element on the substrate of the image display device, it is first necessary to separate the crystal growth substrate and the micro LED element from the crystal growth substrate by a laser lift-off (LLO) process (see, for example, Patent Documents 1). After separating the micro LED element from the crystal growth substrate, the micro LED element is picked up and aligned, and then mounted on the substrate of the image display device. In order to prevent the micro LED elements from scattering when the micro LED elements are separated from the crystal growth substrate by LLO, a transfer member is attached to the surface of the crystal growth substrate on which the micro LED elements are formed. The micro LED element separated from the crystal growth substrate is temporarily fixed to the surface of the transfer member to prevent scattering.
In addition, in the present disclosure, a micro LED element means an LED element having a side length of 100 μm or less.

Japanese Unexamined Patent Application Publication No. 2015-23240

Since the micro LED element is very small and thin, it is easily cracked and difficult to handle. When the micro LED element is fixed to the crystal growth substrate, it is difficult for cracks to occur. I have something to do.
In addition, even if the transfer member can solve the above problems at the time of LLO, if it does not temporarily fix the micro LED element with an appropriate adhesive force, the micro LED element cannot be picked up from the transfer member and transferred to the substrate. Defects may occur.
Also, the micro LED element fabricated on the crystal growth substrate is singulated by etching or the like. In order to manufacture more micro LED elements on the crystal growth substrate for the purpose of cost reduction, the interval between individual micro LED elements is generally set to a width of several tens of μm, which is very narrow. Therefore, when picking up the micro LED elements by the pick-up means, it is desirable that the intervals between the individual micro LED elements are widened.
Furthermore, when mounting micro LED elements on a substrate of an image display device, for example, when red, blue, and green micro LED elements are arranged on the substrate, it is necessary to provide an interval of 100 μm or more between blue micro LED elements. be. When the micro LED elements are mounted on the substrate at intervals using a die mounter or the like, it may take a long time, resulting in low productivity.
The present disclosure has been made in view of the above-described conventional circumstances, and according to one aspect of the present disclosure, an LED transfer member excellent in transfer rate and stretchability of micro LED elements in a laser lift-off method, and using this LED transfer member An object of the present invention is to provide a method for manufacturing an LED device that has

Specific means for achieving the above object are as follows.
<1> having a region on at least a part of the surface where the adhesive strength is reduced by light irradiation,
An LED transfer member having a tensile strength of 1 MPa to 10 MPa at 50°C.
<2> The LED relocating member according to <1>, which has a substrate and an adhesive layer disposed on the substrate, wherein the adhesive layer is a region whose adhesive strength is reduced by light irradiation.
<3> The LED relocating member according to <1> or <2>, wherein the adhesive strength of the region where the adhesive strength is reduced after light irradiation is 0.7 N/25 mm or less.
<4> A method for manufacturing an LED device using the LED transfer member according to any one of <1> to <3>.
<5> An optical device substrate having a crystal growth substrate, a buffer layer formed on the crystal growth substrate and an LED element formed on the buffer layer in a state of being divided into individual devices. The surface of the LED transfer member according to any one of <1> to <3> on which the LED elements are formed is brought into contact with the optical device substrate by affixing the LED relocation member to form an affixed body;
irradiating the buffer layer with laser light to destroy the buffer layer;
transferring the LED element to the LED transfer member by separating the crystal growth substrate and the LED transfer member;
expanding the distance between the LED elements transferred to the LED transfer member by extending the LED transfer member;
A method of manufacturing an LED device, comprising irradiating the extended LED relocation member with light to reduce adhesive strength of the LED relocation member.
<6> The method for manufacturing an LED device according to <5>, wherein the length of the long side of the LED element is 100 μm or less.

According to one embodiment of the present disclosure, it is possible to provide an LED transfer member excellent in transfer rate and stretchability of micro LED elements in the laser lift-off method, and a method for manufacturing an LED device using this LED transfer member.

FIG. 2 is a cross-sectional view of a transfer member 10 having a two-layer structure; FIG. 3 is a cross-sectional view of a transfer member 20 having a one-layer structure; 3 is a cross-sectional view of an optical device substrate 30; FIG. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device. It is a figure for demonstrating the manufacturing method of an LED device.

A detailed description will be given below of the embodiment for implementing the present disclosure. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

In the present disclosure, the term "process" includes a process that is independent of other processes, and even if the purpose of the process is achieved even if it cannot be clearly distinguished from other processes. .
In the present disclosure, the numerical range indicated using "-" includes the numerical values before and after "-" as the minimum and maximum values, respectively.
In the numerical ranges described step by step in the present disclosure, the upper limit or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described step by step. . Moreover, in the numerical ranges described in the present disclosure, the upper or lower limits of the numerical ranges may be replaced with the values shown in the examples.
In the present disclosure, each component may contain multiple types of applicable substances. When there are multiple types of substances corresponding to each component in the composition, the content rate or content of each component is the total content rate or content of the multiple types of substances present in the composition unless otherwise specified. means quantity.
In the present disclosure, the term “layer” or “film” refers to the case where the layer or film is formed in the entire region when observing the region where the layer or film is present, and only a part of the region. It also includes the case where it is formed.
In the present disclosure, the term "laminate" indicates stacking layers, and two or more layers may be bonded, or two or more layers may be detachable.
In the present disclosure, "(meth)acryloyl group" means at least one of acryloyl group and methacryloyl group.
In the present disclosure, the average thickness of a layer or film is a value obtained by measuring the thickness of the target layer or film at five points and giving the arithmetic mean value.
The thickness of a layer or film can be measured using a micrometer or the like. In this disclosure, when the thickness of a layer or film can be measured directly, it is measured using a micrometer. On the other hand, when measuring the thickness of one layer or the total thickness of a plurality of layers, the thickness may be measured by observing the cross section of the object to be measured using an electron microscope.

<LED transfer member>
The LED transfer member of the present disclosure has a region on at least a part of the surface where the adhesive force is reduced by light irradiation, and has a tensile strength of 1 MPa to 10 MPa at 50°C. Hereinafter, the LED transfer member of the present disclosure may be simply referred to as "transfer member".
According to the LED transfer member of the present disclosure, the micro LED transfer rate in the LLO method is excellent. Although the reason is not clear, it is presumed as follows.
The LED transfer member of the present disclosure has a region where the adhesive force is reduced by light irradiation, and before light irradiation, the LED element attached to the region is more firmly held by the LED transfer member than after light irradiation, It becomes possible to separate the LED element from the substrate for crystal growth in the LLO method. In addition, the occurrence of cracks, misalignment, etc. due to a weak external force in the LLO method is suppressed. Therefore, the transfer rate from the crystal growth substrate to the LED transfer member is improved.
On the other hand, after light irradiation, the adhesive strength of the area is lowered, so that the LED element temporarily fixed to the area can be easily picked up. Therefore, the transfer rate from the LED transfer member is improved.
From the above, according to the LED transfer member of the present disclosure, it is inferred that the micro LED transfer rate in the LLO method is improved.
Furthermore, in the present disclosure, the tensile strength of the transfer member at 50° C. is set to 1 MPa to 10 MPa. If the tensile strength of the transfer member at 50° C. is 1 MPa or more, the force for extending the distance between the micro LED elements transferred to the transfer member is sufficient when the transfer member is stretched, and the distance between the micro LED elements can be easily expanded. tend to be able. If the tensile strength of the transfer member at 50° C. is 10 MPa or less, the transfer member tends to be easily stretched by an expanding device or the like.
The tensile strength of the transfer member at 50° C. is preferably 2 MPa to 9 MPa, more preferably 3 MPa to 8 MPa.
The tensile strength of the transfer member at 50°C is a value measured using a test piece with a width of 20 mm and a tensile tester at 50°C and a tensile speed of 5 mm/s.

The layer structure of the transfer member is not particularly limited, and may be a structure of one layer or two or more layers. When the transfer member has two or more layers, the material forming one surface of the transfer member and the material forming the other surface of the transfer member can be appropriately selected. power can be adjusted. Therefore, by increasing the adhesive strength of one surface of the transfer member and setting the other surface to exhibit no adhesive strength in the temperature range in which the LLO method is performed, the process adaptability of the transfer member can be improved. .
Hereinafter, the LED transfer member of the present disclosure will be described with reference to the drawings. In addition, the LED transfer member of the present disclosure is not limited to the following embodiments. In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this. In addition, in each drawing, the same reference numerals are given to the same members, and redundant description may be omitted.

FIG. 1 is a cross-sectional view of a transfer member 10 having a two-layer structure.
In FIG. 1 , the transfer member 10 has a base material 12 and an adhesive layer 14 arranged on the base material 12 . The adhesive layer 14 corresponds to the region where the adhesive strength is reduced by light irradiation.
The base material 12 is polyester film such as polyethylene terephthalate film; polytetrafluoroethylene film, polyethylene film, polypropylene film, polymethylpentene film, polyvinyl acetate film, poly-4-methylpentene-1 or other α-olefin alone. Polyolefin films containing polymers, copolymers thereof, and ionomers of the above homopolymers or copolymers; polyvinyl chloride films; polyimide films; and various plastic films such as urethane resin films. The substrate 12 is not limited to a single-layer film, and may be a multi-layer film obtained by combining two or more of the above plastic films or two or more of the same type of plastic films.

From the standpoint of stretchability, the substrate 12 is preferably a polyolefin film or a urethane resin film. The substrate 12 may contain various additives such as an antiblocking agent, if necessary.

The average thickness of the base material 12 may be appropriately set as required. The average thickness of the base material 12 is preferably 50 μm to 500 μm.
If the average thickness of the base material 12 is 50 μm or more, there is a tendency that the deterioration of the extensibility of the transfer member is suppressed. If the average thickness of the base material 12 is 500 μm or less, the strain of the transfer member tends to be suppressed when the transfer member is stretched.
As long as there is no problem with the handling of the transfer member, the thickness of the substrate 12 is preferably thin from the viewpoint of cost, more preferably 50 μm to 400 μm, even more preferably 50 μm to 300 μm.
However, the average thickness of the base material 12 is preferably a thickness that does not hinder the transmission of high energy rays when a high energy ray (in particular, ultraviolet) curable adhesive is used as the adhesive constituting the adhesive layer 14 . From such a point of view, the thickness is preferably 50 μm to 500 μm, more preferably 50 μm to 300 μm.
When the substrate 12 is composed of a plurality of film-like substrates as described above, it is preferable to adjust the average thickness of the entire substrate 12 within the above range.

The base material 12 may be chemically or physically surface-treated as necessary in order to improve adhesion with the adhesive layer 14 . The surface treatments include, for example, corona treatment, chromic acid treatment, ozone exposure, flame exposure, high voltage shock exposure, and ionizing radiation treatment.

The adhesive layer 14 is not particularly limited as long as it has a characteristic that the adhesive strength is reduced by light irradiation.

The adhesive layer 14 is preferably composed of an adhesive component that has adhesive strength to the LED element on the crystal growth substrate at 25°C.
Examples of the base resin of the adhesive component that constitutes the adhesive layer 14 include acrylic resins, various synthetic rubbers, natural rubbers, polyimide resins, and the like. Among these, acrylic resins are preferred. From the viewpoint of reducing the adhesive residue of the adhesive component, the base resin preferably has a functional group such as a hydroxyl group or a carboxyl group that can react with the cross-linking agent described below.

A (meth)acryloyl group may be introduced into the base resin using a functional group such as a hydroxyl group or a carboxyl group contained in the base resin as a starting point. A (meth)acryloyl group may be introduced into the base resin by reacting the hydroxyl group contained in the base resin with a compound containing a hydroxyl group-reactive functional group such as 2-methacryloxyethyl isocyanate and a (meth)acryloyl group. Alternatively, a (meth)acryloyl group may be introduced into the base resin by reacting the carboxyl group contained in the base resin with a compound containing a functional group capable of reacting with the carboxyl group such as glycidyl methacrylate and a (meth)acryloyl group. When such a curable resin is used as the base resin, the adhesive strength of the adhesive layer 14 can be reduced by curing the base resin by light irradiation.

Moreover, in order to adjust the adhesive force of the adhesive layer 14, the adhesive component may contain a cross-linking agent capable of cross-linking reaction with the functional group of the base resin. The type of cross-linking agent is not particularly limited, and can be selected according to the type of base resin and the like. Specifically, isocyanate cross-linking agents, melamine cross-linking agents, peroxide cross-linking agents, metal alkoxide cross-linking agents, metal chelate cross-linking agents, metal salt cross-linking agents, carbodiimide cross-linking agents, oxazoline cross-linking agents, aziridine cross-linking agents, amine cross-linking agents, etc. is mentioned. These cross-linking agents may be used alone or in combination of two or more.
Among the cross-linking agents, isocyanate cross-linking agents are preferred from the viewpoint of stable adhesion properties.
If the reaction rate between the base resin and the cross-linking agent is slow, catalysts such as amines and tin-based compounds may be used as necessary.

The isocyanate cross-linking agent is not particularly limited, and can be selected from known compounds having an isocyanate group (isocyanate compounds). From the viewpoint of reactivity, bifunctional isocyanate compounds (compounds having two isocyanate groups) and polyfunctional isocyanates (compounds having three or more isocyanate groups) are preferred, and polyfunctional isocyanate compounds are more preferred.

In addition, in order to appropriately adjust the adhesive properties of the adhesive layer 14, the adhesive component may appropriately contain optional ingredients such as rosin-based, terpene resin-based tackifiers, and various surfactants.

When the base resin contains a (meth)acryloyl group, the adhesive layer 14 may contain a photopolymerization initiator so that the base resin is cured by light irradiation. The photopolymerization initiator is not particularly limited as long as it can be decomposed by light irradiation to generate radicals to initiate polymerization of the base resin. The type and content of the photopolymerization initiator are appropriately selected in consideration of the wavelength of light applied to the adhesive layer 14, the intensity of light, the amount of (meth)acryloyl groups contained in the base resin, and the like.

In order to prevent contamination and destruction of the LED element due to volatilization of the components contained in the adhesive layer 14, the content of the component having a boiling point or sublimation point of 100 ° C. or less is set in the entire adhesive layer 14. is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1.5% by mass or less.
The boiling point or sublimation point of each component contained in the adhesive layer 14 can be determined, for example, by thermogravimetry.

The average thickness of the adhesive layer 14 is preferably 1 μm to 100 μm, more preferably 2 μm to 50 μm, even more preferably 5 μm to 40 μm. By setting the average thickness of the adhesive layer to 1 μm or more, it is possible to ensure sufficient adhesive strength with the LED element. On the other hand, from the viewpoint of economy, the average thickness of the adhesive layer 14 is preferably 100 μm or less.

The adhesive strength of the adhesive layer 14 after light irradiation is preferably 0.7 N/25 mm or less, more preferably 0.5 N/25 mm or less, from the viewpoint of suppressing a decrease in the transfer rate of the LED elements from the transfer member. is more preferably 0.4 N/25 mm or less, and particularly preferably 0.3 N/25 mm or less. The adhesive strength of the adhesive layer 14 after light irradiation may be 0.01 N/25 mm or more from the viewpoint of suppressing the occurrence of positional displacement of the LED elements.
The adhesive strength of the adhesive layer 14 before light irradiation is preferably 0.8 N/25 mm or more, and preferably 1.0 N/25 mm or more, from the viewpoint of stably holding the LED element by the adhesive layer 14 in the LLO process. is more preferable, and 1.2 N/25 mm or more is even more preferable. The adhesive strength of the adhesive layer 14 before light irradiation may be 5.0 N/25 mm or less.
The adhesive strength of the adhesive layer 14 refers to the peel strength with SUS. Adhesive strength refers to a value obtained by measuring peel strength by a method conforming to JIS C 5016:1994 (conductor peeling strength).

FIG. 2 is a cross-sectional view of the transfer member 20 having a one-layer structure. The transfer member 20 as a whole corresponds to a region where the adhesive strength is reduced by light irradiation.
The component constituting the transfer member 20 having a one-layer structure may be the same component as the adhesive layer 14 constituting the transfer member 10 shown in FIG. Since the transfer member 20 does not have a base material, it is preferable that the components constituting the transfer member 20 have higher mechanical strength than the adhesive layer 14 in order to improve the strength of the transfer member 20 itself. . For example, it is preferable to increase the amount of the cross-linking agent added or the amount of the catalyst added compared to the adhesive layer 14 .
A frame-shaped structure for reinforcing the transferable member 20 may be arranged on the periphery of the transferable member 20 .

The method of manufacturing the transfer member is not particularly limited, and the transfer member can be manufactured according to techniques known in the art. For example, the two-layer transfer member 10 can be manufactured according to the following method.
On the protective film, a coating liquid containing the components of the adhesive layer and a solvent is applied by a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, a curtain coating method, or the like, and the solvent is removed. A sticky layer is formed by removal. Specifically, the solvent is preferably removed by heating at 50° C. to 200° C. for 0.1 minute to 90 minutes. The drying conditions are preferably such that the organic solvent in the adhesive layer evaporates up to 1.5% by mass or less, provided that voids are not generated in the coating and drying steps and the adjustment of the viscosity of the coating solution is not affected.
The prepared protective film with an adhesive layer and the base material are laminated under a temperature condition of room temperature to 60 ° C. so that the adhesive layer and the base material face each other, and are laminated using a roll laminator or the like. A transfer member having a layer structure can be obtained. The protective film is removed when the transfer member 10 is used.
Further, by peeling the protective film from the adhesive layer-attached protective film, a transfer member having a single-layer structure can be obtained.

Examples of films that can be suitably used as protective films include A-63 (release agent: modified silicone) manufactured by Teijin DuPont Films Limited, and A-31 (release agent: modified silicone) manufactured by Teijin DuPont Films Limited. Pt-based silicone) and the like.

The average thickness of the protective film is appropriately selected within a range that does not impair workability, and is usually preferably 100 μm or less from an economical point of view. The average thickness of the protective film is more preferably in the range of 10 μm to 75 μm, still more preferably 25 μm to 50 μm. If the average thickness of the protective film is 10 μm or more, troubles such as tearing of the protective film during production of the transfer member tend not to occur. Further, when the average thickness of the protective film is 100 μm or less, the protective film tends to be easily peeled off when the transfer member is used.

<Method for manufacturing LED device>
The manufacturing method of the LED device of the present disclosure uses the LED transfer member of the present disclosure. The manufacturing method of the LED device of the present disclosure is not particularly limited as long as it uses the LED transfer member of the present disclosure. Since the LED transfer member of the present disclosure has a region on at least a part of the surface in which the adhesive strength is reduced by light irradiation, the method for manufacturing an LED device of the present disclosure reduces the adhesive strength of the transfer member at any stage. It is preferable to irradiate light as much as possible.
One embodiment of the method for manufacturing an LED device of the present disclosure includes, for example, a crystal growth substrate, a buffer layer formed on the crystal growth substrate in a state of being divided into individual devices, and a buffer layer formed on the buffer layer. and the side of the optical device substrate on which the LED elements are formed is brought into contact with the surface of the LED transfer member of the present disclosure on the side having the region where the adhesive strength is reduced, and the optical device substrate The LED relocating member is affixed to form an affixed body, the buffer layer is irradiated with laser light to break the buffer layer, and the crystal growth substrate and the LED relocating member are separated by separating the moving the LED element to the LED moving member, extending the LED moving member to extend the distance between the LED elements moved to the LED moving member, irradiating the extended LED moving member with light, It may include reducing the adhesive force of the LED transfer member.
The manufacturing method of the LED device of the present disclosure is suitable for manufacturing a micro LED element having a long side length of 100 μm or less.

An example of a method for manufacturing an LED device using the LED transfer member of the present disclosure will be described below with reference to the drawings. In the following description, the case of using the transfer member 10 having a two-layer structure shown in FIG. 1 will be described as an example, but the layer structure of the transfer member is not particularly limited.
FIG. 3 is a cross-sectional view of the optical device substrate 30. As shown in FIG. The optical device substrate 30 includes a crystal growth substrate 32, a buffer layer 34 formed on the crystal growth substrate 32 in a state of being divided into individual devices, and LED elements (micrometers) formed on the buffer layer 34. LED element) 36.

The crystal growth substrate 32 serves as a base for forming the LED elements 36 on its surface. Examples of the crystal growth substrate 32 include sapphire (AlO), SiC, Si, GaAs, GaN, MgAl ₂ O ₄ and the like. From the viewpoint of crystal growth, sapphire, SiC, Si, GaN substrates, and the like are preferable for crystal formation of GaN-based semiconductors used for blue LEDs. For AlInGaP-based or AlGaAs-based crystal growth used for red LEDs, a GaAs substrate is preferable from the viewpoint of crystal growth.

The buffer layer 34 is a layer that is destroyed by laser light irradiation, and functions as a separation layer for separating the LED element 36 from the crystal growth substrate 32 . The components constituting the buffer layer 34 are appropriately selected in consideration of the components of the crystal growth substrate 32 and the LED elements 36 . Also, the method of forming the buffer layer 34 is not particularly limited.

The LED element 36 is responsible for the light emission characteristics of the micro LED, and the LPE method (Liquid Phase Epitaxy) and the MOVPE method (Metal Organic Vapor Phase Epitaxy) are formed on the crystal growth substrate 32. growth method), molecular beam epitaxy (MBE), or the like. The components of the LED element 36 are, for example, aluminum gallium arsenide (AlGaAs): red, gallium arsenide phosphide (GaAsP): red/orange/yellow, and indium gallium nitride (InGaN)/gallium nitride (GaN)/aluminum gallium nitride (AlGaN). : orange/yellow/green/blue/purple, gallium phosphide (GaP): red/yellow/green, zinc selenide (ZnSe): green/blue, and aluminum indium gallium phosphide (AlGaInP): orange/yellow-orange/yellow・ Green is mentioned.

A bump 38 that is a conductive protrusion may be provided on the LED element 36 . As the material of the bumps, gold, silver, copper, tin-silver-based, tin-lead-based, tin-bismuth-based, tin-copper-based solders, tin, nickel, indium, etc. are used as main components. Bump 38 may be composed of a single component or multiple components. When bumps 38 are composed of a plurality of components, these metal components may be formed so as to form a laminated structure.

In the LED device manufacturing method, as shown in FIG. 4, the transfer member 10 is attached to the optical device substrate 30 by bringing the adhesive layer 14 side of the transfer member 10 into contact with the side of the optical device substrate 30 on which the LED elements 36 are formed. A patch 40 is obtained by sticking.
The method of adhering the transfer member 10 to the optical device substrate 30 is not particularly limited, and conventionally known lamination methods can be used. Examples of the lamination method include a lamination method using a roll laminator, a diaphragm type laminator, a vacuum roll laminator, a vacuum diaphragm type laminator, and the like.

Lamination conditions may be appropriately set depending on the physical properties and characteristics of the optical device substrate 30 and the transfer member 10 . For example, in the case of a roll-type laminator, the lamination temperature is preferably room temperature (25°C) to 200°C, more preferably room temperature (25°C) to 150°C, and even more preferably room temperature (25°C) to 100°C. If the lamination temperature is 25° C. or higher, the transfer member 10 can be firmly adhered to the optical device substrate 30, so the transfer member 10 and the crystal growth substrate 32 are separated after irradiating the buffer layer 34 with laser light. In this case, the separation of the LED element 36 from the transfer member 10 and the occurrence of positional deviation of the LED element 36 tend to be prevented. If the lamination temperature is 200° C. or less, a difference in thermal expansion between the transfer member 10 and the optical device substrate 30 is unlikely to occur, and distortion, sagging, etc. due to low elasticity of the base material 12 constituting the transfer member 10 are unlikely to occur. Therefore, there is a tendency to prevent the LED element 36 from being displaced.
In the case of a diaphragm-type laminator, the temperature conditions are the same as those of the roll-type laminator described above. The crimping time is preferably 5 seconds to 300 seconds, more preferably 5 seconds to 200 seconds, even more preferably 5 seconds to 100 seconds. If the crimping time is 5 seconds or longer, the transfer member 10 can be firmly attached to the optical device substrate 30, so the transfer member 10 and the crystal growth substrate 32 are separated after the buffer layer 34 is irradiated with the laser light. In this case, the separation of the LED element 36 from the transfer member 10 and the occurrence of positional deviation of the LED element 36 tend to be prevented. If the crimping time is 200 seconds or less, the productivity of LED devices tends to improve.
The lamination pressure is preferably 0.1 MPa to 3 MPa, more preferably 0.1 MPa to 2 MPa, even more preferably 0.1 MPa to 1 MPa. If the lamination pressure is 0.1 MPa or more, the transfer member 10 can be firmly attached to the optical device substrate 30, so that the transfer member 10 and the crystal growth substrate 32 are separated after the buffer layer 34 is irradiated with the laser light. In this case, the separation of the LED element 36 from the transfer member 10 and the positional deviation of the LED element 36 tend to be prevented. If the lamination pressure is 3 MPa or less, damage to the LED elements 36 due to the bonding pressure applied to the LED elements 36 is prevented, and the occurrence of cracks and the like tends to be suppressed.

Next, as shown in FIG. 5, the buffer layer 34 is irradiated with laser light 50 . In FIG. 5, the buffer layer 34 is irradiated with the laser light 50 from the opposite side of the optical device substrate 30 where the LED elements 36 are formed, but the irradiation direction of the laser light 50 is particularly limited. Alternatively, the buffer layer 34 may be irradiated with the laser light 50 from the substrate 12 side of the transfer member 10 .
By irradiating the buffer layer 34 with the laser light 50, the buffer layer 34 is destroyed.

Examples of lasers include lamp-excited lasers (xenon flash lamps, etc.) using a discharge lamp as an excitation light source, diode-excited lasers (LD-excited) excited by an LD (laser diode), and the like. The medium includes solids, gases, semiconductors, etc. YAG lasers (using a YAG rod composed of yttrium (Y), aluminum (A), and garnet (G)) are used for solids, and excimer lasers are used for gases (gas). Laser), _CO2 laser, etc. are commonly used.
Diode-pumped lasers generally use solid-state lasers (diode-pumped solid-state lasers: DPSS lasers) (DPSS: Diode Pumping Solid-State). A DPSS laser is preferable to an excimer laser because it is inexpensive and easy to maintain.

Next, as shown in FIG. 6, the crystal growth substrate 32 and the transfer member 10 are separated. At this time, the LED elements 36 formed on the crystal growth substrate 32 are transferred while being adhered to the adhesive layer 14 of the transfer member 10 .

Then, as shown in FIG. 7, the transfer member 10 is stretched. In FIG. 7, the transfer member 10 is extended in the planar direction of the transfer member indicated by the arrow in FIG. By extending the transfer member 10, the interval between the LED elements 36 is widened in the planar direction of the transfer member. Since the LED elements 36 are stuck to the adhesive layer 14 of the transfer member 10 when the transfer member 10 is extended, the separation of the LED elements 36 from the transfer member 10 and the displacement of the LED elements 36 do not occur. It tends to be prevented from occurring.

A method for stretching the transfer member 10 is not particularly limited, and includes, for example, a push-up method and a pulling method.
The push-up method is a method in which the transfer member 10 is stretched by raising a stage having a predetermined shape after fixing the transfer member 10 . The pulling method is a method in which the moving member 10 is stretched by pulling in a predetermined direction in parallel with the moving member 10 that has been set after fixing the moving member 10 . The push-up method is preferable because the space between the LED elements 36 can be uniformly extended and the device area required (occupied) is small and compact.

The stretching conditions may be appropriately set according to the characteristics of the transfer member 10 . For example, the amount of pushing up or pulling is preferably 10 mm to 500 mm, more preferably 10 mm to 300 mm. If the amount of push-up or the amount of pull is 10 mm or more, there is a tendency that the interval between the LED elements 36 can be sufficiently extended. If the thrust amount or the pull amount is 500 mm or less, scattering of the LED elements 36, positional displacement, etc. tend to be prevented.
The temperature during stretching may be appropriately set according to the characteristics of the transfer member 10 . The temperature during stretching is, for example, preferably 10°C to 200°C, more preferably 10°C to 150°C, even more preferably 20°C to 100°C. If the temperature during stretching is 10° C. or higher, there is a tendency that the transfer member 10 can be easily stretched. If the temperature during stretching is 200° C. or less, distortion, sagging, and the like due to thermal expansion, low elasticity, and the like of the transfer member 10 are prevented, and scattering and positional displacement of the LED elements 36 tend to be prevented. be.
The stretching speed may be appropriately set according to the characteristics of the transfer member 10 . For example, the stretching speed is preferably 0.1 mm/sec to 500 mm/sec, more preferably 0.1 mm/sec to 300 mm/sec, and even more preferably 0.1 mm/sec to 200 mm/sec. If the stretching speed is 0.1 mm/sec or more, deterioration of productivity tends to be suppressed. If the drawing speed is 500 mm/sec or less, scattering of the LED elements 36 tends to be suppressed.

After that, the transfer member 10 is irradiated with light. As a result, the adhesive strength of the adhesive layer 14 on the transfer member 10 is reduced, making it easier to pick up the LED element 36 from the transfer member 10 .

Next, as shown in FIG. 8, the LED element 36 is picked up from the transfer member 10 using the pickup means 52, and as shown in FIG. After mounting, the bumps 38 and the pads 56 are bonded to manufacture the micro LED.

The mounting board 54 on which the LED element 36 is mounted is not particularly limited as long as it is a normal circuit board. The mounting substrate 54 is mainly composed of glass, glass epoxy, polyester, ceramic, epoxy, bismaleimide triazine, polyimide, or the like, and a wiring pattern is formed by removing unnecessary portions of a metal layer formed on the surface of the substrate by etching. substrate, a substrate having a wiring pattern formed on its surface by metal plating or the like, a substrate having a wiring pattern formed by printing a conductive substance on its surface, and the like can be used.

The surface of the wiring pattern including the pads 56 on the mounting board 54 is mainly composed of gold, silver, copper, tin-silver-based, tin-lead-based, tin-bismuth-based, tin-copper-based solder, tin , nickel, indium tin oxide (ITO), indium, or the like. The wiring pattern may consist of only a single component, or may consist of a plurality of components. Moreover, the wiring pattern may have a structure in which a plurality of metal layers are laminated.

Methods for picking up the LED element 36 include a method of picking up the LED element 36 using a pick-up tool such as a flip chip bonder and a die mounter with an air pressure difference, and a pick-up method of providing an adhesive on the pick-up tool and picking up with an adhesive force. After being picked up, the LED elements 36 are aligned and mounted on the pads 56 provided on the mounting substrate 54 . The LED element 36 may be picked up using a roller or the like provided with an adhesive.

A carrier can also be used when picking up the LED element 36 from the transfer member 10 .
As shown in FIG. 6, the crystal growth substrate 32 and the transfer member 10 are separated, and then the transfer member 10 is extended as shown in FIG. 7. After that, as shown in FIG. A carrier 60 is adhered to the surface of the transferred side. Light irradiation to the transferable member 10 may be performed after the transferable member 10 is stretched, and may be applied before or after the carrier 60 is adhered to the transferable member 10 .

Then, the carrier 60 and the transfer member 10 are separated. The LED element 36 is transferred to the carrier 60 . Next, as shown in FIG. 11, the LED elements 36 transferred to the carrier 60 are mounted on the pads 56 provided on the mounting board 54, and the bumps 38 and the pads 56 are bonded to manufacture the micro LED.

The method of transferring the LED elements 36 to the carrier 60 is not particularly limited, and conventionally known lamination methods can be used. Examples of the lamination method include a lamination method using a roll laminator, a diaphragm type laminator, a vacuum roll laminator, a vacuum diaphragm type laminator, and the like.

Lamination conditions may be appropriately set depending on the physical properties and characteristics of the carrier 60 and the transfer member 10 . For example, in the case of a roll-type laminator, the lamination temperature is preferably room temperature (25°C) to 200°C, more preferably room temperature (25°C) to 150°C, and even more preferably room temperature (25°C) to 100°C. If the lamination temperature is 25° C. or higher, the carrier 60 can be firmly attached to the transfer member 10 , so when the carrier 60 and the transfer member 10 are separated, the LED element 36 can be removed from the transfer member 10 or the carrier 60 . This tends to prevent the occurrence of separation, positional deviation of the LED element 36, and the like. If the lamination temperature is 200° C. or lower, a difference in thermal expansion between the transfer member 10 and the carrier 60 is less likely to occur, and distortion, sagging, etc. due to low elasticity of the base material 12 constituting the transfer member 10 are less likely to occur. This tends to prevent the positional deviation of the LED element 36 from occurring.
In the case of a diaphragm-type laminator, the temperature conditions are the same as those of the roll-type laminator described above. The crimping time is preferably 5 seconds to 300 seconds, more preferably 5 seconds to 200 seconds, even more preferably 5 seconds to 100 seconds. If the crimping time is 5 seconds or more, the carrier 60 can be firmly attached to the transfer member 10, so that when the carrier 60 and the transfer member 10 are separated, the LED element 36 cannot be removed from the transfer member 10 or the carrier 60. This tends to prevent the occurrence of separation, positional deviation of the LED element 36, and the like. If the crimping time is 200 seconds or less, the productivity of LED devices tends to improve.
The lamination pressure is preferably 0.1 MPa to 3 MPa, more preferably 0.1 MPa to 2 MPa, even more preferably 0.1 MPa to 1 MPa. If the lamination pressure is 0.1 MPa or more, the carrier 60 can be firmly attached to the transfer member 10, so that when the carrier 60 and the transfer member 10 are separated, the LED element 36 cannot be removed from the transfer member 10 or the carrier 60. Detachment, displacement of the LED element 36, and the like tend to be prevented. If the lamination pressure is 3 MPa or less, damage to the LED elements 36 due to the bonding pressure applied to the LED elements 36 is prevented, and the occurrence of cracks and the like tends to be suppressed.

The carrier 60 is not particularly limited as long as it can withstand the temperature and pressure at the time of attachment, prevents the LED elements 36 from being damaged, and maintains the distance between the LED elements 36 . Carrier 60 is preferably heat resistant to withstand the lamination temperatures described above.
The material of the carrier 60 is not particularly limited, but examples thereof include silicon, glass, SUS, iron, Cu plates, glass epoxy substrates, and the like.

The average thickness of the carrier 60 is preferably 100 μm to 5 mm, more preferably 100 μm to 4 mm, even more preferably 100 μm to 3 mm. If the average thickness of the carrier 60 is 100 μm or more, the handleability is improved. Even if the carrier 60 is thick, it is not expected that the handling efficiency will be significantly improved.

The carrier 60 may consist of multiple layers. In addition to the layer responsible for heat resistance and handleability described above, there may be a layer laminated with an adhesive layer or a temporary fixing material from the viewpoint of imparting adhesion control. The adhesive force may be set as appropriate. From the viewpoint of transferability of the LED elements 36 from the transfer member 10 to the carrier 60, the adhesive strength imparted to the carrier 60 is preferably higher than the adhesive strength of the adhesive layer 14 after light irradiation.

The method of mounting the LED elements 36 from the carrier 60 to the mounting board 54 is not particularly limited, and conventionally known lamination methods can be used. Examples of the lamination method include a lamination method using a roll laminator, a diaphragm type laminator, a vacuum roll laminator, a vacuum diaphragm type laminator, and the like.

The lamination conditions may be appropriately set according to the physical properties and characteristics of the carrier 60, the mounting board 54 and the LED element 36. An underfill material may be supplied on the mounting board 54 in advance for the purpose of protecting the bumps 38, protecting the connecting portions between the bumps 38 and the mounting board 54, improving the reliability of the micro LED, and the like. When the underfill material is supplied, the LED elements 36 are easily fixed to the mounting substrate 54, and the positional deviation of the LED elements 36 tends to be less likely to occur.

For example, in the case of a roll-type laminator, the lamination temperature is preferably room temperature (25°C) to 200°C, more preferably room temperature (25°C) to 150°C, and even more preferably room temperature (25°C) to 100°C. If the lamination temperature is 25° C. or higher, the LED element 36 can be firmly fixed to the mounting board 54 , so when the carrier 60 and the mounting board 54 are separated, the LED element 36 does not detach from the mounting board 54 . This tends to prevent occurrence of positional displacement of the element 36 and the like. If the lamination temperature is 200° C. or less, a difference in thermal expansion between the carrier 60 and the mounting board 54 is less likely to occur, and positional displacement of the LED elements 36 tends to be prevented.
In the case of a diaphragm-type laminator, the temperature conditions are the same as those of the roll-type laminator described above. The crimping time is preferably 5 seconds to 300 seconds, more preferably 5 seconds to 200 seconds, even more preferably 5 seconds to 100 seconds. If the crimping time is 5 seconds or more, the LED element 36 can be firmly fixed to the mounting board 54, so when the carrier 60 and the mounting board 54 are separated, the LED element 36 is detached from the mounting board 54, and the LED This tends to prevent occurrence of positional displacement of the element 36 and the like. If the crimping time is 200 seconds or less, the productivity of LED devices tends to improve.
The lamination pressure is preferably 0.1 MPa to 3 MPa, more preferably 0.1 MPa to 2 MPa, even more preferably 0.1 MPa to 1 MPa. If the lamination pressure is 0.1 MPa or more, the LED element 36 can be firmly fixed to the mounting substrate 54, so when the carrier 60 and the mounting substrate 54 are separated, the LED element 36 does not detach from the mounting substrate 54, This tends to prevent the occurrence of positional deviation of the LED element 36 and the like. If the lamination pressure is 3 MPa or less, damage to the LED element 36 due to the pressure applied to the LED element 36 is prevented, and the occurrence of cracks and the like tends to be suppressed.

It should be noted that the present disclosure is not limited to the specific configuration of the embodiment as described above, and various modifications can be made without departing from the gist of the present disclosure.

Hereinafter, the present disclosure will be described more specifically based on examples, but the present disclosure is not limited to these examples.

(Production of acrylic resin)
1000 g of ethyl acetate, 650 g of 2-ethylhexyl acrylate, 350 g of 2-hydroxyethyl acrylate and 3.0 g of azobisisobutyronitrile were mixed in an autoclave with a capacity of 4000 ml equipped with a three-one motor, a stirring blade and a nitrogen inlet tube, and mixed uniformly. After stirring until the content became , nitrogen bubbling was performed for 60 minutes at a flow rate of 100 ml/min to deaerate dissolved oxygen in the system. The temperature was raised to 60° C. over 1 hour, and polymerization was carried out for 4 hours after the temperature was raised. After that, the temperature was raised to 90° C. over 1 hour, held at 90° C. for 1 hour, and then cooled to room temperature.
Then 1000 g of ethyl acetate was added and diluted with stirring. To this, 0.1 g of methoquinone as a polymerization inhibitor and 0.05 g of dioctyltin dilaurate as a urethanization catalyst were added. After reacting for 6 hours at , it was cooled to room temperature. Thereafter, ethyl acetate was added to adjust the non-volatile content in the acrylic resin solution to 35% by mass, thereby obtaining an acrylic resin solution having a functional group capable of chain polymerization.
When the acid value and hydroxyl value of this resin were measured according to JIS K0070:1992, no acid value was detected. A hydroxyl value was found to be 121 mgKOH/g.
The obtained acrylic resin solution was vacuum-dried overnight at 60° C., and the obtained solid content was subjected to elemental analysis using a fully automatic elemental analyzer (varioEL) manufactured by Elemental. From the measured nitrogen content, the content of 2-methacryloxyethyl isocyanate introduced into the acrylic resin was calculated to be 0.59 mmol/g.
In addition, SD-8022 / DP-8020 / RI-8020 manufactured by Tosoh Corporation is used, Gelpack GL-A150-S / GL-A160-S manufactured by Showa Denko Materials Co., Ltd. is used for the column, and tetrahydrofuran is used as the eluent. As a result of GPC measurement using the acrylic resin, the polystyrene-equivalent weight average molecular weight of the acrylic resin was 420,000.

(Production of transfer member A)
For this acrylic resin solution (100 parts by mass in terms of the solid content of the acrylic resin), 1 part by mass of a polyfunctional isocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate L, solid content 75% by mass) as a solid content as a cross-linking agent, 1 part by mass of 1-hydroxycyclohexylphenyl ketone (Irgacure 184, manufactured by IGM Resins B.V.) as a photopolymerization initiator, and ethyl acetate was added so that the total solid content was 27% by mass, and the mixture was uniformly mixed for 10 minutes. was stirred to After that, the obtained solution was coated on a release-treated polyethylene terephthalate (average thickness of 25 μm) as a protective film so that the average thickness of the adhesive layer when dried was 10 μm, and then dried to form an adhesive layer. . Furthermore, the adhesive layer surface was laminated on the substrate film (average thickness 100 μm). After that, aging was performed at 40° C. for 4 days. Thus, the transfer member A was obtained.

The base film is an ionomer resin Himilan 1706 (manufactured by DuPont Mitsui Polychemicals, ionomer resin), an ethylene/1-hexene copolymer, a butene/α-olefin copolymer, and Himilan 1706 laminated in this order. A three-layer resin film (Himilan 1706/ethylene/1-hexene copolymer and butene/α-olefin copolymer/Himilan 1706, average thickness 100 μm) was used.

The adhesive layer and protective film and base film were laminated with a roll laminator at 40°C to form a protective film/adhesive layer/base film order. When used as a transfer member, the protective film was removed before use.

(Production of transfer members B to E)
Transfer members B to E were produced in the same manner except that the ratio of the adhesive layer components and the type of base material were changed.
In the transfer member B, the ratio of the adhesive layer components was set to 100 parts by mass of acrylic resin, 4 parts by mass of Coronate L, and 184 parts by mass of Irgacure.
In the transfer member C, the ratio of the adhesive layer components was set to acrylic resin: 100 parts by mass, Coronate L: 0.2 parts by mass, and Irgacure 184:1 parts by mass.
In the transfer member D, the ratio of the adhesive layer components was set to acrylic resin: 100 parts by mass, Coronate L: 1 part by mass, and Irgacure 184: 1 part by mass.
In the transfer member E, the ratio of the adhesive layer components was set to acrylic resin: 100 parts by mass, Coronate L: 1 part by mass, and Irgacure 184: 1 part by mass.
The base film of the transfer member D was changed to a silicone sheet, and the base film of the transfer member E was changed to a polyethylene terephthalate film.

The method of preparing the evaluation sample and various conditions are described below.

A transfer member was placed on a test vehicle (Test Vehicle, made by Nitride Semiconductor) in which LED elements were formed through a buffer layer in a state divided into individual devices on a 3.1 mm x 3.6 mm sapphire die. was laminated. The transfer member had a size of 200 mm×200 mm and an average thickness of 110 μm. The size of the LED element was 25 μm×50 μm×6 μmt, and the bump size provided on the LED element was 15 μm×15 μm×2 μmt. There were 4465 LED elements on the sapphire die. A diaphragm-type vacuum laminator (Laminator V130, manufactured by Nikko Materials) was used to laminate the transfer member onto the sapphire die to obtain an adhered body. This was used as a measurement sample. The lamination conditions were 40° C./0.5 MPa/10 seconds.

(Measurement of LLO transfer rate)
A laser was irradiated from the sapphire die side of the prepared sample. DFL7560 (manufactured by DISCO Corporation) was used as the LLO device. The irradiation intensity of the laser beam was set to 1W. After the laser irradiation, the sapphire die and the transfer member were separated. The transfer rate of the LED element to the transfer member when separated was measured. An LED element that could be transferred to the transfer member without cracks or misalignment was regarded as a non-defective product. When the LED elements remained on the sapphire die side, or when the sapphire die and the transfer members were separated, the LED elements were detached or displaced from the transfer members, and the number of the LED elements was counted as defective products.
Six sapphire dies (4465 x 6 LED elements) were evaluated, and the number of successfully transferred LED elements was divided by the total number of LED elements (4465 x 6) and multiplied by 100 for transfer. This value was taken as the LLO transfer rate. A is given when the LLO transfer rate is 95% or more, B is given when it is 90% or more but less than 95%, and C is given when it is less than 90%. If the evaluation is A or B, there is no practical problem.

(Measurement of transfer rate to carrier)
Using the transfer member obtained by separating the sapphire die for the measurement of the LLO transfer rate as a sample, the LED element was transferred from the transfer member to the carrier. After the transfer member was irradiated with UV (UV exposure machine ML-320FSAT, manufactured by Mikasa Co., Ltd.), the transfer member was laminated on the carrier. As a carrier, a carrier having a configuration of Si die/adhesive layer was used. The Si die had a diameter of 20 mm and a thickness of 725 μmt. The component ratios of the adhesive layer were acrylic resin: 100 parts by mass, Coronate L: 7 parts by mass, and Irgacure: 1 part by mass. The average thickness of the adhesive layer was 10 μm, and the adhesive strength was 1.1 N/25 mm.
After lamination, the transfer member and the carrier were separated. The UV irradiation condition was 300 mJ/cm ² . For lamination, a diaphragm-type vacuum laminator (Laminator V130, manufactured by Nikko Materials) was used. The lamination conditions were 40° C./0.5 MPa/30 seconds. An LED element that could be transferred from the transfer member to the carrier without cracks or misalignment was regarded as a non-defective product. When the LED elements remained on the transfer member, or when the LED elements were separated from the carrier when the transfer member and the carrier were separated, the LED elements were counted as defective products.
Evaluate the transfer member to which the LED elements for 6 sapphire dies (4465 LED elements x 6) have been transferred, and calculate the number of LED elements successfully transferred from the transfer member to the carrier as the total number of LED elements (4465 The value obtained by dividing by 6) and multiplying by 100 was calculated as the transfer rate, and this value was taken as the transfer rate to the carrier. A was given when the transfer rate to the carrier was 95% or more, B was given when it was 90% or more but lower than 95%, and C was given when it was less than 90%. If the evaluation is A or B, there is no practical problem.

(Adhesion measurement)
The adhesive strength of the transfer member before and after UV irradiation was measured by the following method.
Using a laminator GK-13DX (manufactured by Lamy Corporation) on SUS (width 25 mm) having an average thickness of 0.5 mm, a sample before UV irradiation was obtained by laminating the transfer member at a lamination temperature of 40°C. Using an ultraviolet exposure machine (Mikasa Co., Ltd. "ML-320FSAT"), this sample was irradiated with ultraviolet rays under the conditions of an ultraviolet wavelength of 365 nm and an exposure amount of 300 mJ/cm ² to obtain a sample after UV irradiation. The peel strength of each of the sample before UV irradiation and the sample after UV irradiation was measured by a method conforming to JIS C 5016:1994 (Peeling strength of conductor). The peel strength was defined as adhesive strength.

(Tensile strength measurement)
An autograph (AG-Xplus, manufactured by Shimadzu Corporation) was used to measure the tensile strength at 50°C. An evaluation sample with a width of 20 mm was cut from the transfer member. Using this evaluation sample, measurement was performed at 25 mm between chucks, a pulling speed of 5 mm/s, and 50°C. The value when the sample for evaluation was stretched 100% (twice the initial length) was taken as the tensile strength.

(Expanding process evaluation)
The transferred member obtained by separating the sapphire die when measuring the LLO transfer rate was set in a 12-inch expander device (MX-5154FN manufactured by Omiya Kogyo Co., Ltd.). The stage temperature) was pushed up at 50° C., and the transfer member was stretched. If the distance between the LED elements after stretching the relocating member can be expanded from the initial value (approximately 50 μm) to 1 mm or more, A is the case. B was given when an apparatus error occurred because the width of the transfer member could not be increased, or when the distance between the LED elements could not be increased to 1 mm even when pushed up by 100 mm.

As is clear from the evaluation results in Table 1, the LED transfer member of the present disclosure is excellent in the transfer rate and stretchability of the micro LED elements.

The disclosure of Japanese Patent Application No. 2021-075245 filed on April 27, 2021 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.

10, 20 Transfer member 12 Base material 14 Adhesive layer 30 Optical device substrate 32 Crystal growth substrate 34 Buffer layer 36 LED element 38 Bump 40 Attached body 50 Laser beam 52 Pickup means 54 Mounting substrate 56 Pad 60 Carrier

Claims

At least a part of the surface has a region where the adhesive strength is reduced by light irradiation,
An LED transfer member having a tensile strength of 1 MPa to 10 MPa at 50°C.
The LED relocating member according to claim 1, comprising a base material and an adhesive layer disposed on the base material, wherein the adhesive layer is a region whose adhesive strength is reduced by light irradiation.
The LED relocating member according to claim 1 or 2, wherein the adhesive strength after light irradiation of the area where the adhesive strength is lowered is 0.7 N/25 mm or less.
A method for manufacturing an LED device using the LED transfer member according to any one of claims 1 to 3.
The LED of an optical device substrate having a crystal growth substrate, a buffer layer formed on the crystal growth substrate in a state of being divided into individual devices, and an LED element formed on the buffer layer. The LED is transferred to the optical device substrate by bringing the surface of the LED transfer member according to any one of claims 1 to 3, which has a region where the adhesive force is reduced, into contact with the side on which the element is formed. affixing a member to form an adhered body;
irradiating the buffer layer with laser light to destroy the buffer layer;
transferring the LED element to the LED transfer member by separating the crystal growth substrate and the LED transfer member;
expanding the distance between the LED elements transferred to the LED transfer member by extending the LED transfer member;
A method of manufacturing an LED device, comprising irradiating the extended LED relocation member with light to reduce adhesive strength of the LED relocation member.
The manufacturing method of the LED device according to claim 5, wherein the length of the long side of the LED element is 100 µm or less.