Electrode peripheral embedded material, electrode peripheral embedded material prebaked film, method for manufacturing electrode peripheral embedded material prebaked film, and micro LED display element

Abstract

An electrode peripheral embedded material according to the present invention is a positive photosensitive adhesive composition containing the following components (A), (B), (C), and (D). Component (A): an alkali-soluble resin having a phenolic hydroxyl group, a glass transition temperature (Tg) of the polymer being 60°C or less Component (B): a cross-linking agent Component (C): a photosensitizer containing quinonediazide Component (D): a solvent

Description

Electrode periphery filling material, electrode periphery filling material pre-baked film, method for manufacturing electrode periphery filling material pre-baked film, and micro LED display element

[0001] The present invention relates to an electrode periphery filling material, a pre-baked film of the electrode periphery filling material, a manufacturing method of a pre-baked film of the electrode periphery filling material, and a micro LED display element, and in particular to an electrode periphery filling material used in a micro LED display element, a pre-baked film of the electrode periphery filling material for a micro LED display element, and a micro LED display element using the pre-baked film of the electrode periphery filling material for a micro LED display element and its underfill film.

[0002] Currently, liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDs) are primarily used in flat panel displays used in mobile phones, monitors, and TVs. While LCDs have well-established mass production technology, they are inexpensive and can be made large. However, the need for a backlight for display results in poor form factor and flexibility. OLEDs, while offering superior flexibility, face the challenge of shortening their lifespan as the brightness of the display increases. To address these drawbacks, micro-LED display elements, which use inorganic light-emitting diodes arranged on each pixel of an array substrate, have been developed in recent years. Because micro-LED display elements use micrometer-sized inorganic light-emitting diodes as light sources, they can achieve higher brightness, higher color purity, and a longer lifespan than LCDs and OLEDs. Furthermore, because LEDs are arranged for each pixel, each pixel can be isolated and the display is highly flexible.

[0003] The LED elements that serve as light sources are supplied as small pieces by epitaxially growing a semiconductor layer on a sapphire substrate, forming electrodes, and then dicing the substrate. Micro LED display elements require the LED elements manufactured in this way to be arranged on an array substrate with high precision. The pick-and-place method, in which each LED element is installed individually, has been considered as a method for arranging LED elements on an array substrate. However, this method requires a significant amount of time to install the LEDs, making it unsuitable for mass production.

[0004] Therefore, in recent years, a stamp method has been proposed in which a large number of LED elements are picked up from a sapphire substrate at once using an adhesive base material (stamp), mass-transferred to an array substrate, and then the LED elements are metal-bonded to the electrodes of the array substrate by thermocompression bonding using a bonding head or by laser heating (Non-Patent Documents 1 and 2).This method is expected to significantly improve throughput compared to the pick-and-place method, as it allows a large number of LED elements to be arranged on the array substrate and bonded to the array substrate at once.

[0005] Adv. Optical Mater. 2015, 3, 1313-1335SID 2017 DIGEST, 257

[0006] As described above, the stamp-based mass transfer method has the potential to significantly improve throughput compared to the pick-and-place method, in which LED elements are individually arranged on an array substrate. However, this method involves mass-transferring LED elements from a sapphire substrate to an array substrate, due to the difference in adhesiveness between the array substrate and the LED elements and the stamp and the LED elements. Therefore, an adhesive film is required on the array substrate. However, forming a film on the array substrate for mass transfer presents the problem of difficulty in subsequent wiring extraction.

[0007] Furthermore, when mass-transferred LED elements are metal-bonded to an array substrate by thermocompression bonding or laser heating, it is known that if an oxide film is formed on the electrode portion of the array substrate or LED element, metal bonding cannot be achieved and electrical continuity is poor. For this reason, when joining LED elements, a flux treatment to remove the metal oxide film is usually required before bonding.

[0008] Therefore, the present invention aims to provide an electrode periphery embedding material that has photosensitivity, flux property, and adhesive property, and that, by forming a film only in necessary locations on an array substrate by patterning as necessary, facilitates the placement of LED elements on the LED mounting electrode on the substrate and enables efficient metal bonding between the electrode of the LED element and the electrode on the LED mounting electrode.

[0009] Another object of the present invention is to provide a pre-baked film of a material for filling up the periphery of an electrode that is patterned on an array substrate and that uses the material for filling up the periphery of an electrode to enable efficient mass transfer and metal bonding of LED elements.

[0010] Another object of the present invention is to provide a method for producing a pre-baked film of a material for filling up the periphery of an electrode, which uses the material for filling up the periphery of an electrode and enables efficient mass transfer and metal bonding of an LED element.

[0011] The present invention aims to provide a micro LED display element having a pre-baked film of a material filling the periphery of an electrode, which enables efficient mass transfer and metal bonding of the LED element.

[0012] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have discovered the present invention. Specifically, the present invention relates to the following: 1. A filling material for the periphery of an electrode containing the following components (A), (B), (C), and (D): Component (A): an alkali-soluble resin that is a polymer having a phenolic hydroxyl group, the polymer having a glass transition temperature (Tg) of 60°C or less; Component (B): a crosslinking agent; Component (C): a photosensitizer having a quinone diazide; and Component (D): a solvent. 2. The filling material for the periphery of an electrode according to 1, wherein the component (A) is a polymer containing a structural unit derived from a monomer (A2) that gives a homopolymer having a Tg of 0°C or less. 3. The filling material for the periphery of an electrode according to 2, wherein the component (A) is an acrylic polymer containing, as structural components, a monomer (A1) having a phenolic hydroxyl group and a polymerizable unsaturated group, and a structural unit derived from a monomer (A2) that gives a homopolymer having a Tg of 0°C or less. 4. 4. The electrode periphery filling material according to 3, wherein the monomer (A1) having a phenolic hydroxyl group and a polymerizable unsaturated group is selected from the group consisting of p-hydroxystyrene, m-hydroxystyrene, α-methyl-p-hydroxystyrene, and compounds represented by the following formula (1): In formula (1), P represents a (meth)acrylic group, a (meth)acrylamide group, an N-methyl(meth)acrylamide group, or a maleimide group; １ represents a single bond, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, or a combination thereof; １represents a single bond, —O—, —COO—, or —OCO—; d １ represents a substituted or unsubstituted hydroxyphenyl group. 5. The electrode periphery filling material according to any one of 3 to 4, wherein the monomer (A2) that gives a homopolymer having a Tg of 0°C or less is a compound represented by the following formula (2): In formula (2), R ２ represents a hydrogen atom or a methyl group; ２ represents an oxygen atom or a sulfur atom, b ２ represents a linear, branched, or cyclic alkylene group having 2 to 20 carbon atoms, or a combination thereof, and —CH ２ - may be replaced by an oxygen atom, provided that they are not adjacent to each other. ２ represents a single bond, —O—, —COO—, or —OCO—; d ２ represents a hydrogen atom or a hydroxyl group. 6. The electrode periphery filling material according to any one of 1 to 5, wherein the component (A) is an acrylic polymer further containing, as a constituent, a constituent unit derived from a monomer (A3) containing an aromatic hydrocarbon group represented by the following formula (3): In formula (3), R ３ represents a hydrogen atom or a methyl group; ３ is an oxygen atom, a sulfur atom, -NH-, or -N(CH ３ )-, b ３ represents a single bond, or a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or a combination thereof, and —CH ２ - may be replaced by an oxygen atom, provided that they are not adjacent to each other. ３ represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -N(CH ３ )CO-, or -CON(CH ３ )-, d ３represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms. 7. The electrode periphery filling material according to any one of 1 to 6, wherein the amount of component (B) is 5 to 60 parts by mass per 100 parts by mass of component (A). 8. The electrode periphery filling material according to any one of 1 to 7, wherein the amount of component (C) is 10 to 100 parts by mass per 100 parts by mass of component (A). 9. The electrode periphery filling material according to any one of 1 to 8, further comprising a surfactant as component (E), the content of which is 0.01 to 1.0 part by mass per 100 parts by mass of component (A). 10. A prebaked film of the electrode periphery filling material obtained by prebaking a coating film of the electrode periphery filling material according to any one of 1 to 9. 11. A patterned prebaked film of the electrode periphery filling material, the positive photosensitive adhesive film according to 10. 12. 12. An LED element mounting substrate comprising: an array substrate that serves as a substrate for a micro LED display element; and a pre-baked film of electrode periphery embedding material provided on the array substrate and obtained by pre-baking a coating film of the electrode periphery embedding material described in any one of 1 to 9. 13. An LED element mounting substrate according to 12, wherein the pre-baked film of electrode periphery embedding material is patterned according to the mounting location of an LED element. 14. A micro LED display element comprising: an LED element mounting substrate according to 12 or 13; and an LED element bonded to the LED element mounting substrate, wherein an electrode of the LED element is bonded to an LED mounting electrode of the LED element mounting substrate, and the periphery of the joint between the electrode of the LED element and the LED mounting electrode is fixed and protected by a post-baked film of the electrode periphery embedding material pre-baked film.

[0013] The electrode periphery filling material of the present invention has photosensitivity, flux property and adhesive property, and can form a pre-baked film of electrode periphery filling material, which is a positive photosensitive adhesive film that can be patterned only in the required areas on the array substrate.By using this patterned pre-baked film of electrode periphery filling material, it is possible to form an electrode periphery filling material that enables the mass transfer and metal bonding of LED elements to be made more efficient.

[0014] The electrode periphery filling material of the present invention is a positive photosensitive adhesive composition containing the following components (A), (B), (C), and (D): Component (A): an alkali-soluble resin having a phenolic hydroxyl group, the polymer of which has a glass transition temperature (Tg) of 60°C or lower Component (B): a crosslinking agent Component (C): a photosensitizer having a quinone diazide Component (D): a solvent (hereinafter also referred to as solvent (D)) Each component will be described in detail below.

[0015] <Component (A)> The component (A) is an alkali-soluble resin that is a polymer having a phenolic hydroxyl group and has a glass transition temperature (Tg) of 60° C. or lower. The alkali-soluble resin is preferably an acrylic polymer.

[0016] In the present invention, the acrylic polymer refers to a polymer obtained using a monomer having a polymerizable unsaturated group, i.e., a polymerizable group containing a carbon-carbon double bond in its structure, such as an acrylic acid ester, a methacrylic acid ester, styrene, maleimide, etc. The alkali-soluble resin of component (A) is preferably an alkali-soluble acrylic polymer, and there are no particular limitations on the types of main chain skeleton and side chains of the polymer constituting the acrylic polymer.

[0017] If the weight-average molecular weight of the alkali-soluble resin of component (A) is too low, less than 20,000, the alkali resistance decreases in the alkali development step of lithography, and the desired pattern may not be formed, whereas if the weight-average molecular weight is too high, exceeding 150,000, residues may remain during development. From the viewpoint of these patterning properties, the weight-average molecular weight of the alkali-soluble resin is preferably in the range of 20,000 to 150,000, and more preferably in the range of 30,000 to 100,000.

[0018] The alkali-soluble resin of component (A) can be synthesized simply by copolymerizing a monomer mixture containing a monomer (A1) having a phenolic hydroxyl group and a polymerizable unsaturated group, and a monomer (A2) that provides a homopolymer with a Tg of 0° C. or less. Here, the term "homopolymer" refers to a polymer of the monomer (A2) alone, and is a polymer having a weight-average molecular weight of 3,000 or more that can be obtained by polymerizing the monomer (A2) at a temperature of 50 to 110° C. in a solvent optionally containing a polymerization initiator or the like, or by polymerizing the monomer (A2) in the presence of a photoradical generator or the like by irradiating it with ultraviolet light.

[0019] The constituent monomers of component (A) are described in detail below. Monomer (A1) is a monomer having a phenolic hydroxyl group and a polymerizable unsaturated group, and is preferably at least one monomer selected from p-hydroxystyrene, m-hydroxystyrene, α-methyl-p-hydroxystyrene, and compounds represented by the following formula (1): In formula (1), P represents a (meth)acrylic group, a (meth)acrylamide group, an N-methyl(meth)acrylamide group, or a maleimide group, and is preferably a (meth)acrylic group. １ represents a single bond, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, or a combination thereof, and is preferably a single bond or a linear alkylene group having 1 to 6 carbon atoms. １ represents a single bond, —O—, —COO—, or —OCO—, and is preferably a single bond or —O—. １ represents a substituted or unsubstituted hydroxyphenyl group, preferably a p-hydroxyphenyl group. Substituents on the hydroxyphenyl group include halogen atoms, alkyl groups having 1 to 3 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, alkoxy groups having 1 to 3 carbon atoms, fluoroalkyl groups having 1 to 3 carbon atoms, fluoroalkenyl groups having 2 to 3 carbon atoms, fluoroalkoxy groups having 1 to 3 carbon atoms, alkyloxycarbonyl groups having 2 to 3 carbon atoms, cyano groups, and nitro groups. The presence of these hydroxyphenyl groups not only makes component (A) alkali-soluble, but also exhibits fluxing properties.

[0020] Examples of the monomer (A1) include p-hydroxystyrene, α-methyl-p-hydroxystyrene, N-(p-hydroxyphenyl)maleimide, N-(p-hydroxyphenyl)acrylamide, N-(p-hydroxyphenyl)methacrylamide, p-hydroxyphenyl acrylate, and p-hydroxyphenyl methacrylate, which can be used alone or in combination of two or more. Among these, monomers selected from p-hydroxyphenyl acrylate and p-hydroxyphenyl methacrylate are preferred.

[0021] Monomer (A2) is a monomer that gives a homopolymer having a Tg of 0° C. or less, and is preferably a compound represented by the following formula (2). In formula (2), R ２ represents a hydrogen atom or a methyl group. ２ represents an oxygen atom or a sulfur atom, preferably an oxygen atom. represents a linear, branched, or cyclic alkylene group having 2 to 20 carbon atoms, or a combination thereof, preferably a linear, branched, or cyclic alkylene group having 2 to 12 carbon atoms, or a combination thereof, more preferably a linear or branched alkylene group having 2 to 12 carbon atoms. ２ -CH in the alkylene group ２ - may be replaced by an oxygen atom, provided that they are not adjacent to each other. ２ represents a single bond, —O—, —COO—, or —OCO—, and preferably represents a single bond or —O—. ２ represents a hydrogen atom or a hydroxyl group.

[0022] Specific examples of the monomer (A2) include ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-hexyl methacrylate, n-heptyl acrylate, n-heptyl methacrylate, n-octyl acrylate, n-octyl methacrylate, nonyl acrylate, nonyl methacrylate, isononyl acrylate, isononyl methacrylate, lauryl acrylate, lauryl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, 3-hydroxypropyl ... Examples of the acrylate include propyl acrylate, 4-hydroxybutyl acrylate, ethyl carbitol acrylate, glycidyl acrylate, methoxytriethylene glycol acrylate, methoxytriethylene glycol methacrylate, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl acrylate, 2-ethoxyethyl methacrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 3-methoxybutyl methacrylate, diethylene glycol monoacrylate, and diethylene glycol monomethacrylate, which may be used alone or in combination of two or more, but are not limited to these.

[0023] From the viewpoint of suitably achieving the effects of the present invention, the constituent units derived from monomer (A1) in component (A) preferably account for 10 to 50 mass% of the total of the constituent units derived from monomer (A1) and the constituent units derived from monomer (A2), and the constituent units derived from monomer (A2) in component (A) preferably account for 50 to 90 mass% of the total of the constituent units derived from monomer (A1) and the constituent units derived from monomer (A2).

[0024] In the present invention, when obtaining the acrylic polymer of component (A), it is preferable to contain a monomer (A3) containing an aromatic hydrocarbon group represented by the following formula (3). In formula (3), R ３ represents a hydrogen atom or a methyl group. ３is an oxygen atom, a sulfur atom, -NH-, or -N(CH ３ )-, preferably an oxygen atom or -NH-, more preferably an oxygen atom. ３ is a single bond, or a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or a combination thereof, preferably a linear, branched, or cyclic alkylene group having 2 to 12 carbon atoms, or a combination thereof, more preferably a linear alkylene group having 2 to 8 carbon atoms. ３ In the alkylene group, non-adjacent —CH ２ - may be replaced by an oxygen atom, provided that they are not adjacent to each other. ３ represents a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -N(CH ３ )CO-, or -CON(CH ３ )-, preferably a single bond, —O—, —COO—, or —OCO—, and more preferably a single bond or —O—. ３ represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms, preferably a substituted or unsubstituted phenyl group. Examples of substituents on the aromatic hydrocarbon group include halogen atoms, alkyl groups having 1 to 3 carbon atoms, alkenyl groups having 2 to 3 carbon atoms, alkoxy groups having 1 to 3 carbon atoms, fluoroalkyl groups having 1 to 3 carbon atoms, fluoroalkenyl groups having 2 to 3 carbon atoms, fluoroalkoxy groups having 1 to 3 carbon atoms, alkyloxycarbonyl groups having 2 to 3 carbon atoms, cyano groups, and nitro groups. When component (A) contains a structural unit derived from a monomer having an aromatic hydrocarbon group represented by formula (3), the alkali resistance of unexposed areas is improved in the development step after exposure, and the contrast ratio when patterned can be improved.

[0025] Specific examples of monomer (A3) include 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, phenyl acrylate, phenyl methacrylate, 4-methylphenyl acrylate, 4-methylphenyl methacrylate, 3-phenoxypropyl acrylate, 3-phenoxypropyl methacrylate, 4-phenoxybutyl acrylate, 4-phenoxybutyl methacrylate, 6-phenoxyhexyl acrylate, 8-phenoxyoctyl acrylate, 2-phenoxypropyl 2-methyl-2-propenoate, 2-(1-methyl-2-phenoxyethoxy)ethyl 2-methyl-2-propenoate, benzyl acrylate, benzyl methacrylate, 4-ethoxybenzyl methacrylate, naphthyl acrylate, and naphthyl methacrylate, which may be used alone or in combination of two or more thereof, but are not limited thereto. Of these, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, phenyl acrylate, phenyl methacrylate, 4-methylphenyl acrylate, 3-phenoxypropyl acrylate, 3-phenoxypropyl methacrylate, 4-phenoxybutyl acrylate, 4-phenoxybutyl methacrylate, and benzyl methacrylate are preferred.

[0026] When component (A) contains structural units derived from monomer (A3), from the viewpoint of suitably achieving the effects of the present invention, the total of the structural units derived from monomer (A1) and the structural units derived from monomer (A2) in component (A) is preferably 40 to 100% by mass, more preferably 40 to 80% by mass, and even more preferably 50 to 70% by mass, based on the total of the structural units derived from monomer (A1), the structural units derived from monomer (A2), and the structural units derived from monomer (A3). The structural units derived from monomer (A3) in component (A) are preferably 0 to 60% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass, based on the total of the structural units derived from monomer (A1), the structural units derived from monomer (A2), and the structural units derived from monomer (A3).

[0027] In the present invention, when obtaining the acrylic polymer of component (A), other monomers copolymerizable with the above-mentioned monomers (A1) to (A3) can be used in combination. Specific examples of the other monomers include acrylic acid ester compounds, methacrylic acid ester compounds, maleimides, acrylamide compounds, acrylonitrile, styrene compounds, and vinyl compounds. Specific examples of the other monomers are listed below, but are not limited to these.

[0028] Examples of the acrylic acid ester compound include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, 2-methyl-2-adamantyl acrylate, anthryl acrylate, anthrylmethyl acrylate, 2,2,2-trifluoroethyl acrylate, 2-aminoethyl acrylate, 2-propyl-2-adamantyl acrylate, caprolactone 2-(acryloyloxy)ethyl ester, and poly(ethylene glycol) ethyl ether acrylate.

[0029] Examples of the methacrylic acid ester compound include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 2-methyl-2-adamantyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, anthryl methacrylate, anthrylmethyl methacrylate, 2,2,2-trifluoroethyl methacrylate, 2-aminomethyl methacrylate, γ-butyrolactone methacrylate, 2-propyl-2-adamantyl methacrylate, caprolactone 2-(methacryloyloxy)ethyl ester, and poly(ethylene glycol) ethyl ether methacrylate.

[0030] Examples of the acrylamide compound include N-methylacrylamide, N-methylmethacrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylamide, N-methoxymethylacrylamide, N-methoxymethylmethacrylamide, N-butoxymethylacrylamide, and N-butoxymethylmethacrylamide.

[0031] Examples of the vinyl compound include methyl vinyl ether, benzyl vinyl ether, cyclohexyl vinyl ether, vinyl naphthalene, vinyl anthracene, vinyl carbazole, allyl glycidyl ether, 3-ethenyl-7-oxabicyclo[4.1.0]heptane, 1,2-epoxy-5-hexene, and 1,7-octadiene monoepoxide.

[0032] Examples of the styrene compound include styrenes having no hydroxy group, such as styrene, α-methylstyrene, chlorostyrene, and bromostyrene.

[0033] The method for obtaining the alkali-soluble resin used in the present invention is not particularly limited, but it can be obtained, for example, by carrying out a polymerization reaction at a temperature of 50 to 110°C in a solvent containing the monomer (A1) and the monomer (A2), optionally the monomer (A3) and the other monomers described above, and optionally a polymerization initiator, etc. The solvent used in this case is not particularly limited as long as it dissolves the monomers constituting the alkali-soluble resin and the alkali-soluble resin. Specific examples include the solvents described below in the section on (D) solvent.

[0034] The alkali-soluble resin (hereinafter also referred to as the specific copolymer) thus obtained is usually in the form of a solution dissolved in a solvent.

[0035] The specific copolymer solution obtained as described above can be reprecipitated by adding the solution to a solvent such as diethyl ether or water under stirring. The resulting precipitate can then be filtered and washed, and then dried at room temperature or by heating under normal or reduced pressure to obtain a powder of the specific copolymer. This procedure can remove polymerization initiators and unreacted monomers coexisting with the specific copolymer, resulting in a purified powder of the specific copolymer. If sufficient purification cannot be achieved in a single procedure, the resulting powder can be redissolved in a solvent and the above procedure repeated. In the present invention, the specific copolymer powder can be used as is, or the powder can be redissolved in, for example, the solvent (D) described below and used in the form of a solution. In the present invention, the alkali-soluble resin of component (A) can be a mixture of multiple specific copolymers.

[0036] <Component (B)> Component (B) is a crosslinking agent, more specifically, a compound having a structure capable of forming a crosslinked structure upon thermal reaction with component (A). Specific examples are given below, but the present invention is not limited to these. The thermal crosslinking agent is preferably selected from, for example, (B1) a crosslinkable compound represented by formula (4) or (5) described below, and (B2) a crosslinking agent having an isocyanurate skeleton. These crosslinking agents can be used alone or in combination of two or more.

[0037] The component (B1) may contain a crosslinkable compound represented by formula (4) or formula (5).

[0038] In formula (4), k is an integer of 2 to 10, m is an integer of 0 to 4, and X ４ represents an organic group having a valence of k. Multiple m's may be the same or different.

[0039] In formula (5), k is an integer of 2 to 10, and X ５ represents a k-valent organic group.

[0040] The component (B1) is not particularly limited as long as it is a compound having a cycloalkene oxide structure represented by formula (4) or a compound having a glycidyl structure represented by formula (5). Specific examples include compounds represented by formulas E-2-1 and E-2-2 below and the commercially available products shown below.

[0041]

[0042]

[0043] Commercially available products include Epolead GT-401, GT-403, GT-301, GT-302, Celloxide 2021, and Celloxide 3000 (trade names manufactured by Daicel Corporation), alicyclic epoxy resins such as Denacol EX-252 (trade names manufactured by Nagase Chemtex Corporation), CY175, CY177, and CY179 (trade names manufactured by CIBA-GEIGY A.G.), Araldite CY-182, CY-192, and CY-184 (trade names manufactured by CIBA-GEIGY A.G.), Epiclon 200 and 400 (trade names manufactured by DIC Corporation), and Epicoat (trade names manufactured by Yuka Shell Epoxy Co., Ltd.). Examples of suitable crosslinkable compounds include EPOCALIC DE-102 and DE-103 (manufactured by ENEOS Corporation), jER152, jER871, and jER872 (manufactured by Mitsubishi Chemical Corporation), and OGSOL-CG500 (manufactured by Osaka Gas Chemicals Co., Ltd.). These crosslinkable compounds may be used alone or in combination of two or more.

[0044] Among these, from the viewpoints of process resistance such as heat resistance, solvent resistance, and long-term baking resistance, as well as transparency, preferred are the compounds represented by the above formulas E-2-1 and E-2-2, which have a cyclohexene oxide structure, Epolead GT-401, GT-403, GT-301, GT-302, Celloxide 2021, Celloxide 3000, Epocalic DE-102, and Epocalic DE-103.

[0045] When component (B1) is selected as the crosslinking agent, the content thereof is 10 to 60 parts by mass, preferably 10 to 50 parts by mass, and more preferably 20 to 40 parts by mass per 100 parts by mass of component (A).

[0046] The positive-type photosensitive adhesive composition of the present invention may also contain a compound having an isocyanurate skeleton as component (B2). Examples of compounds having an isocyanurate skeleton and two or more polymerizable unsaturated double bonds include compounds having an isocyanurate skeleton and two or more polymerizable unsaturated double bonds, such as trimethallyl isocyanurate, tris(2-acryloyloxyethyl)isocyanurate, and tris(2-methacryloyloxyethyl)isocyanurate, and compounds having an isocyanurate skeleton and two or more epoxy moieties, such as triglycidyl isocyanurate, TEPIC-FL, and TEPIC-VL (all manufactured by Nissan Chemical Industries, Ltd.). Inclusion of these compounds having an isocyanurate skeleton in the positive-type photosensitive adhesive composition of the present invention improves the adhesion of mass-transferred LED chips, potentially reducing process defects in the mass-transfer process.

[0047] These compounds can be used alone or in combination of two or more.

[0048] The content of the component (B2) in the positive photosensitive adhesive composition of the present invention is preferably 5 to 60 parts by mass, more preferably 10 to 50 parts by mass, per 100 parts by mass of the component (A).

[0049] <Component (C)> Component (C) is a photosensitizer containing quinone diazide, preferably a photosensitizer containing 1,2-naphthoquinone diazide. The quinone diazide compound is a compound containing either a hydroxyl group or an amino group, or both a hydroxyl group and an amino group, in which preferably 10 to 100 mol %, and particularly preferably 20 to 95 mol %, of these hydroxyl groups or amino groups (when both hydroxyl groups and amino groups are present, the total amount of these groups) is esterified or amidated with quinone diazide sulfonic acid.

[0050] Examples of the compound having a hydroxyl group include phenol, o-cresol, m-cresol, p-cresol, hydroquinone, resorcinol, catechol, methyl gallate, ethyl gallate, 1,3,3-tris(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)propane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 4,4'-dihydroxyphenyl sulfone, 4,4-hexafluoroisopropylidenediphenol, 1,1,1-tris(4-hydroxyphenyl)ethane, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol, 2,4-dihydroxyphenyl Examples of suitable hydroxybenzophenones include phenolic compounds such as 2,3,4-trihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2',3,4,4'-pentahydroxybenzophenone, and 2,5-bis(2-hydroxy-5-methylbenzyl)benzene; and aliphatic alcohols such as ethanol, 2-propanol, 4-butanol, cyclohexanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 2-methoxyethanol, 2-butoxyethanol, 2-methoxypropanol, 2-butoxypropanol, ethyl lactate, and butyl lactate.

[0051] Examples of the compound containing an amino group include anilines such as aniline, o-toluidine, m-toluidine, p-toluidine, 4-aminodiphenylmethane, 4-aminodiphenyl, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, and 4,4'-diaminodiphenyl ether, and aminocyclohexane.

[0052] Furthermore, examples of compounds containing both a hydroxyl group and an amino group include aminophenols such as o-aminophenol, m-aminophenol, p-aminophenol, 4-aminoresorcinol, 2,3-diaminophenol, 2,4-diaminophenol, 4,4'-diamino-4''-hydroxytriphenylmethane, 4-amino-4',4''-dihydroxytriphenylmethane, bis(4-amino-3-carboxy-5-hydroxyphenyl)ether, bis(4-amino-3-carboxy-5-hydroxyphenyl)methane, 2,2-bis(4-amino-3-carboxy-5-hydroxyphenyl)propane, and 2,2-bis(4-amino-3-carboxy-5-hydroxyphenyl)hexafluoropropane; and alkanolamines such as 2-aminoethanol, 3-aminopropanol, and 4-aminocyclohexanol.

[0053] These quinone diazide compounds can be used alone or in combination of two or more.

[0054] The content of component (C) in the positive-type photosensitive adhesive composition of the present invention is preferably 10 to 100 parts by mass, more preferably 15 to 50 parts by mass, and even more preferably 20 to 40 parts by mass, relative to 100 parts by mass of component (A). If the content is less than 10 parts by mass, the difference in dissolution rate between exposed and unexposed portions of the positive-type photosensitive adhesive composition in a developer may become small, making patterning by development difficult. If the content exceeds 100 parts by mass, the quinone diazide compound may not be sufficiently decomposed by short-term exposure, resulting in a decrease in sensitivity, or component (C) may absorb light, reducing the transparency of the cured film.

[0055] <Component (D)> The component (D) solvent used in the present invention dissolves the components (A), (B), and (C), and also dissolves the component (E) described below, which is added as desired. There are no particular limitations on the type or structure of the solvent, as long as it has such dissolving ability.

[0056] Examples of such solvents (D) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-butanone, 3-methyl-2-pentanone, 2- Examples of the solvent include pentanone, 2-heptanone, γ-butyrolactone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0057] These solvents can be used alone or in combination of two or more. Among these (D) solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, 2-heptanone, propylene glycol propyl ether, propylene glycol propyl ether acetate, ethyl lactate, butyl lactate, etc. are preferred from the viewpoints of good film-forming properties and high safety. These solvents are generally used as solvents for photoresist materials.

[0058] <Component (E)> The component (E) is a surfactant. The positive photosensitive adhesive composition of the present invention may further contain a surfactant for the purpose of improving the coating property, as long as the effect of the present invention is not impaired.

[0059] The surfactant of component (E) is not particularly limited, but examples thereof include fluorine-based surfactants, silicone-based surfactants, and nonionic surfactants. Commercially available surfactants of this type are available from manufacturers such as 3M Japan Ltd., DIC Corporation, and AGC Seimi Chemical Co., Ltd. These commercially available products are convenient because they are readily available. Specific examples include Polyfox PF-136A, 151, 156A, 154N, 159, 636, 6320, 656, and 6520 (manufactured by Omnova), Megafac R30, R08, R40, R41, R43, F251, F477, F552, F553, F554, F555, F556, F557, F558, F559, F560, and F56. 1, F562, F563, F565, F567, F570 (manufactured by DIC Corporation), FC4430, FC4432 (manufactured by 3M Japan Ltd.), Asahiguard AG710, Surflon S-386, S-611, S-651 (manufactured by AGC Seimi Chemical Co., Ltd.), Ftergent FTX-218, DFX-18, 220P, 251, 212M, 215M fluorine-based surfactants such as BYK-300, 302, 306, 307, 310, 313, 315, 320, 322, 323, 325, 330, 331, 333, 342, 345, 346, 347, 348, 349, 370, 377, 378, 3455 (manufactured by BYK Japan Co., Ltd.), SH3746, SH3749, SH377 Examples of silicone surfactants include SH8400, SH8410, SH8700, and SF8428 (manufactured by Dow Corning Toray Silicone Co., Ltd.), and KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-618, KF-6011, and KF-6015 (manufactured by Shin-Etsu Chemical Co., Ltd.). The surfactant of component (E) can be used alone or in combination of two or more.

[0060] When a surfactant is used, its content is usually 0.01 to 1.0 part by mass, and preferably 0.02 to 0.8 part by mass, based on 100 parts by mass of component (A).

[0061] <Other Additives> Furthermore, the positive photosensitive resin composition of the present invention may contain, as necessary, a rheology modifier, a pigment, a dye, a storage stabilizer, an antifoaming agent, or a dissolution promoter such as a polyhydric phenol or a polycarboxylic acid, as long as the effects of the present invention are not impaired. Furthermore, the positive photosensitive adhesive composition of the present invention may further contain a fluxing agent to support the fluxing effect of component (A), as long as the effects of the present invention are not impaired. Examples of fluxing agents include nitrogen-containing compounds having unshared electron pairs (imidazoles, amines, etc.), carboxylic acids, phenols, and alcohols. Specific examples include carboxylic acids such as 8-quinolinol, malonic acid, succinic acid, maleic acid, glutaric acid, suberic acid, adipic acid, and sebacic acid, ethylenediamine, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, alkylbenzimidazole (Tough Ace F2 series: manufactured by Shikoku Chemical Industries, Ltd.), diphenylguanidine hydrobromide, cyclohexylamine hydrobromide, diethylamine hydrochloride, triethanolamine hydrobromide, and monoethanolamine hydrobromide.

[0062] <Positive-type photosensitive adhesive composition> The positive-type photosensitive resin composition of the present invention is a composition in which a copolymer obtained by copolymerizing (A) component (A1) to (A2) and, if desired, (A3), a crosslinking agent as a component (B), and a 1,2-quinonediazide compound as a component (C) are dissolved in a solvent (D), and may further contain, if desired, one or more of a surfactant as a component (E) and other additives.

[0063] The proportion of solids in the positive-type photosensitive adhesive composition of the present invention is not particularly limited as long as each component is uniformly dissolved in the solvent, but is, for example, 1 to 80 mass %, or 5 to 60 mass %, or 10 to 50 mass %. Here, the solids refer to all components of the positive-type photosensitive adhesive composition excluding the solvent (D).

[0064] The method for preparing the positive photosensitive adhesive composition of the present invention is not particularly limited, but examples of the preparation method include a method in which component (A) (alkali-soluble resin) is dissolved in solvent (D), and the resulting solution is mixed with component (B) of a crosslinking agent and component (C) of a 1,2-quinonediazide compound in a predetermined ratio to prepare a homogeneous solution, or a method in which component (E) (surfactant) and other additives are further added and mixed, if necessary, at an appropriate stage of this preparation method.

[0065] In preparing the positive-type photosensitive adhesive composition of the present invention, the solution of the copolymer obtained by the polymerization reaction in the (D) solvent can be used as it is, and in this case, when the (B) component, the (C) component, etc. are added to the (A) component solution as described above to prepare a uniform solution, the (D) solvent may be further added for the purpose of adjusting the concentration. In this case, the (D) solvent used in the process of forming the specific copolymer and the (D) solvent used for adjusting the concentration in preparing the positive-type photosensitive adhesive composition may be the same or different.

[0066] The prepared solution of the positive photosensitive adhesive composition is preferably used after being filtered using a filter having a pore size of about 0.2 to 5.0 μm.

[0067] <Coated Film and Cured Film> The positive photosensitive adhesive composition of the present invention can be applied onto a semiconductor substrate (e.g., a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, a substrate coated with a metal such as aluminum, molybdenum, or chromium, a glass substrate, a quartz substrate, an ITO substrate, etc.) by spin coating, flow coating, roll coating, slit coating, spin coating followed by slitting, inkjet coating, or the like, and then pre-dried on a hot plate or in an oven, etc., to form a coated film. The coated film is then pre-baked to form a pre-baked film of an electrode periphery filling material, which is a positive photosensitive adhesive film.

[0068] The conditions for this heat treatment are, for example, a heating temperature and a heating time selected appropriately from the ranges of 70 to 160°C and 0.3 to 60 minutes, respectively. The heating temperature and heating time are preferably 80 to 140°C and 0.5 to 10 minutes.

[0069] The thickness of the pre-baked film of the electrode periphery filling material formed from the positive photosensitive adhesive composition is, for example, 0.1 to 30 μm, or, for example, 1.0 to 10 μm, or, further, for example, 2.0 to 8 μm.

[0070] A mask having a predetermined pattern is attached to the coating film obtained above, and the film is irradiated with light such as ultraviolet light, and then developed with an alkaline developer, whereby the exposed areas are washed out and a sharp pattern is obtained at the end faces.

[0071] Examples of alkaline developers that can be used include aqueous solutions of alkali metal hydroxides such as potassium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline, and aqueous amine solutions such as ethanolamine, propylamine, and ethylenediamine. Furthermore, surfactants and the like can also be added to these developers.

[0072] Among the above, a 0.1 to 2.38 mass % aqueous solution of tetraethylammonium hydroxide is generally used as a developer for photoresists, and the photosensitive adhesive composition of the present invention can also be developed satisfactorily using this alkaline developer without causing problems such as swelling.

[0073] The developing method may be any of the puddle method, dipping method, and swing immersion method, etc. The developing time is usually 15 to 180 seconds.

[0074] After development, the positive photosensitive adhesive film is washed with running water for, for example, 20 to 120 seconds, followed by air drying with compressed air or compressed nitrogen or by spinning, thereby removing water from the substrate and obtaining a patterned film.

[0075] Subsequently, the pattern-forming film is post-baked for thermal curing, specifically by heating using a hot plate, oven, or the like, to obtain a film having excellent heat resistance, transparency, flattening properties, low water absorption, chemical resistance, and the like, and having a good pattern.

[0076] Post-baking is generally performed at a heating temperature selected from the range of 140 to 270° C. for 5 to 30 minutes on a hot plate or for 30 to 90 minutes in an oven.

[0077] Thus, by such post-baking, it is possible to obtain a cured film having the desired good pattern shape.

[0078] As described above, the pre-baked film of electrode periphery filling material obtained from the positive photosensitive adhesive composition of the present invention has photosensitivity, flux property and adhesiveness, and can be suitably used for applications such as a pre-baked film of electrode periphery filling material that enables the efficiency of mass transfer and metal bonding of LED elements by forming a film only in the necessary areas on an array substrate by patterning.

[0079] More specifically, the positive-type photosensitive adhesive composition of the present invention can be used to arrange LED elements at each pixel on an array substrate that serves as a substrate for a micro LED display element. Specifically, a coating film is formed using the positive-type photosensitive adhesive composition of the present invention at the location where the LED elements are to be arranged on the array substrate, and the coating film is prebaked to form a pre-baked film of an electrode periphery filling material. This film is then patterned as necessary to form an LED element mounting substrate having an unpatterned or patterned pre-baked film of an electrode periphery filling material. The LED elements are then mass-transferred onto the pre-baked film of the electrode periphery filling material, which corresponds to the pixel, from the LED element mounting electrodes. The LED mounting electrodes and the electrodes of the LED elements are then metal-bonded by heating and pressing with a bonding head or laser. The pre-baked film of the electrode periphery filling material around the joint is then post-baked to fix and protect the joint between the electrodes of the LED elements and the electrodes on the array substrate. The pre-baked film of the electrode periphery filling material, which is patterned as needed, functions to adhesively fix the LED elements to be mass-transferred and also functions as a flux to remove oxide coatings from the surfaces of the electrodes of the LED elements. The LED elements may be mass-transferred as described above, or may be individually arranged by epitaxially growing a semiconductor layer on a sapphire substrate, for example, to form electrodes, and then dicing the substrate. The micro LED display element of the present invention can be manufactured by placing the LED elements manufactured as described above on a substrate provided on an array substrate and provided with a pre-baked film of the electrode periphery filling material, which is patterned as needed, and then metal-bonding the LED mounting electrodes to the electrodes of the LED elements, followed by post-baking the pre-baked film of the electrode periphery filling material.

[0080] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The abbreviations of the compounds used and the measurement methods for each physical property are as follows. (Monomers) HQMA: p-hydroxyphenyl methacrylate PEA: 2-phenoxyethyl acrylate NOAA: n-octyl acrylate 2EHA: 2-ethyl-n-hexyl acrylate BA: n-butyl acrylate AA: acrylic acid MAA: methacrylic acid MMA: methyl methacrylate HEMA: 2-hydroxyethyl methacrylate NHPMA: N-(4-hydroxyphenyl)methacrylamide CHMI: N-cyclohexylmaleimide Of the above monomers, HQMA, PEA, and NHPMA correspond to monomer (A1), NOAA, 2EHA, and BA correspond to monomer (A2), and AA, MAA, MMA, HEMA, and CHMI correspond to other monomers. (Radical polymerization initiator) AIBN: α,α'-azobisisobutyronitrile (Photosensitizer) QD: Ester of 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]bisphenol and 6-diazo-5,6-dihydro-5-oxo-1-naphthalenesulfonic acid (manufactured by Toyo Gosei Co., Ltd.) (Crosslinkable compound) T1: Epolead GT-401 (butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl) modified ε-caprolactone, manufactured by Daicel Corporation) T2: Epocalic DE-102 (manufactured by ENEOS Corporation) T3: TEPIC-FL (manufactured by Nissan Chemical Industries, Ltd.) (Solvent) PGME: Propylene glycol monomethyl ether

[0081] <Measurement of Molecular Weight> The molecular weight of the polymer was measured using a room temperature gel permeation chromatography (GPC) apparatus (GPC-101) (manufactured by Showa Denko K.K.) and a column (KD-803, KD-805 in series) (manufactured by Showa Denko K.K.) as follows: Column temperature: 50°C Eluent: N,N-dimethylformamide (with lithium bromide monohydrate (LiBr.H) as an additive). ２o-Phosphoric acid) at 30 mmol / L, anhydrous crystalline o-phosphate (o-phosphoric acid) at 30 mmol / L, tetrahydrofuran (THF) at 10 mL / L) Flow rate: 1.0 ml / min Standard samples for preparing a calibration curve: TSK standard polyethylene oxide (molecular weight: approximately 900,000, 150,000, 100,000, and 30,000) (manufactured by Tosoh Corporation) and polyethylene glycol (molecular weight: approximately 12,000, 4,000, and 1,000) (manufactured by Polymer Laboratory Co., Ltd.).

[0082] <Measurement of Glass Transition Temperature (Tg)> The Tg of the polymer obtained in the synthesis examples was measured using a differential scanning calorimetry (DSC) DSC1 (manufactured by METTLER TOREDO) under the following conditions: Heating rate: 10°C / min, Measurement temperature: -50°C to 150°C, Number of measurements: 2. Tg was calculated from the result of the second heating run.

[0083] <Synthesis of Acrylic Polymer> (Synthesis Example 1) HQMA (6.0 g), PEA (6.0 g), and NOAA (8.0 g) were used as monomer components constituting the acrylic polymer, and AIBN (0.2 g) was used as a radical polymerization initiator. These were polymerized in a solvent PGME (16.8 g) at a temperature of 60 ° C. to obtain a solution P1 (acrylic polymer concentration: 30.0 mass%) of an alkali-soluble acrylic polymer component (specific copolymer) having Mn (number average molecular weight): 8,100 and Mw (weight average molecular weight): 50,000. This specific polymer solution was reprecipitated in water and then vacuum dried at 50 ° C. to obtain a viscous resin. The Tg of the obtained acrylic polymer was -1 ° C.

[0084] Synthesis Examples 2 to 6 The polymerization reaction was carried out in the same manner as in Synthesis Example 1, except that the ratio (mass ratio) of the monomer components constituting the acrylic polymer to the radical polymerization initiator used was changed as shown in Table 1, to obtain acrylic polymer solutions P2 to P6 (acrylic polymer concentration: 30.0 mass%) having the molecular weights and Tg shown in Table 1.

[0085] (Synthesis Example 7) As the monomer components constituting the acrylic polymer, NHPMA (4.0 g), HEMA (2.0 g), and CHMI (4.0 g) were used, and AIBN (0.2 g) was used as a radical polymerization initiator. These were polymerized in a solvent PGME (46.5 g) at a temperature of 90 ° C., to obtain a solution P7 (acrylic polymer concentration: 18.0 mass%) of an alkali-soluble acrylic polymer component (specific copolymer) with Mn (number average molecular weight): 5,600 and Mw (weight average molecular weight): 9,300. The obtained acrylic polymer did not show a clear Tg up to 150 ° C.

[0086]

[0087] <Preparation of Positive Photosensitive Adhesive Composition> (Example 1-1) A resin solution was prepared by adding a photosensitizer, a crosslinkable compound, and a solvent to the acrylic polymer solution (P1) obtained in Synthesis Example 1 above, and then stirring the mixture at room temperature for 2 hours to prepare a positive photosensitive adhesive composition V1 having the composition shown in Table 2.

[0088] (Examples 1-2 to 1-5) and (Comparative Examples 1-1 to 1-3) The types and amounts of resin solution, photosensitizer, crosslinking compound, and solvent were changed as shown in Table 2 and added, and then stirred at room temperature for 2 hours to prepare positive-type photosensitive adhesive compositions V2 to V5 and RV1 to RV3 having the compositions shown in Table 2.

[0089]

[0090] Example 2-1 <Adhesion Strength Evaluation> The positive photosensitive adhesive composition V1 prepared in Example 1-1 was applied to a 5 cm x 5 cm ITO substrate using a spin coater, and then prebaked on a hot plate at 100°C for 120 seconds to form a prebaked film with a thickness of 3 μm. Thereafter, using a texture analyzer manufactured by Stable Micro Systems, the peel strength of the coating surface was measured at room temperature (23°C) using a probe (diameter: 25 mm, material: polypropylene), a compression speed: 1 mm / s, a tensile speed: 1 mm / s, a compression load: 400 g, and a compression hold time: 10 s. A value of 0.3 g or more was evaluated as ◯, and a value of less than 0.3 g was evaluated as ×. The results are shown in Table 3.

[0091] <Patterning Evaluation> The positive photosensitive adhesive composition V1 prepared in Example 1-1 was applied to a 5 cm x 5 cm ITO substrate using a spin coater, and then prebaked on a hot plate at a temperature of 100°C for 120 seconds to form a prebaked film with a thickness of 3 μm. This prebaked film was then exposed to a light intensity of 200 mJ / cm at a wavelength of 365 nm. ２ The substrate was irradiated with ultraviolet light through a mask to produce a pattern with lines and spaces spaced 30 μm apart. The substrate was then developed by immersion in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH) for 60 seconds, followed by rinsing with running ultrapure water for 30 seconds. The substrate was then post-baked at 230°C for 30 minutes using an ADVANTEC clean oven to form a cured film. The pattern height of the resulting cured film was evaluated as good (◯) when it was less than ±10% of the pre-baked film thickness of 3 μm, and as poor (×) when it was ±10% or more. Residue within the cutout pattern was evaluated as excellent (◎) when the residue was less than 30 nm, good (◯) when it was 30 nm or more but less than 60 nm, and poor (×) when it was 60 nm or more. The results are shown in Table 3.

[0092] (Examples 2-2 to 2-5 and Comparative Examples 2-1 to 2-3) Using the positive photosensitive adhesive compositions V2 to V5 and RV1 to RV3 prepared in Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-3, the adhesive strength and patterning ability were evaluated in the same manner as in Example 2-1. The results are shown in Table 3.

[0093]

[0094] As shown in Table 3, all of the positive-type photosensitive adhesive compositions of the examples exhibited good adhesive strength and patterning properties. In contrast, the positive-type photosensitive adhesive compositions using acrylic polymers with glass transition temperatures (Tg) of 100°C or higher exhibited insufficient adhesive strength (Comparative Examples 2-1 and 2-3). Furthermore, the compositions in which the acidic component in the acrylic polymer was a carboxylic acid exhibited poor alkali resistance, and no pattern shape could be obtained (Comparative Examples 2-1 to 2-2).

[0095] (Example 3-1) <Flip chip bonding test> As a mounting sample, a TEG (Test Element Group) chip (5.1 mm × 5.1 mm × thickness 700 μm) having 1,700 electrodes with an electrode area of ​​20 μm × 20 μm and an electrode height of 5.5 μm (SnAg solder height 2.3 μm, copper post electrode height 3.2 μm) and a TEG substrate (15 mm × 15 mm × thickness 700 μm) in which copper electrodes were wired to form a daisy chain with the electrodes of the TEG chip were prepared. The positive photosensitive adhesive composition V1 prepared in Example 1-1 was applied to the TEG substrate using a spin coater, and then prebaked on a hot plate at a temperature of 100 ° C. for 120 seconds to form a prebaked film with a thickness of 6 μm. Next, using a Panasonic flip chip bonder, a TEG chip was flip chip bonded to the TEG substrate with this pre-baked film at a stage temperature of 60°C, a head temperature of 370°C for 60 seconds, and a head pressure of 150 N. This was followed by post-baking (post-curing) at 230°C for 30 minutes to obtain a bonded assembly. The resulting bonded assembly was evaluated for the presence or absence of TEG chip peeling (no peeling: ◯, peeling: ×) and the conduction resistance value (less than 100Ω: ◯, 100Ω or more: ×). The results are shown in Table 4.

[0096] (Examples 3-2 to 3-4, Comparative Example 3-1) Using the positive photosensitive adhesive compositions V2 to V4 and RV3 prepared in Examples 1-2 to 1-4 and Comparative Example 1-3, a flip chip bonding test was carried out in the same manner as in Example 3-1. The results are shown in Table 4.

[0097] (Comparative Example 3-2) A bonded body was formed in the same manner as in Example 3-1, except that instead of using a positive photosensitive adhesive composition, the TEG chip and the TEG substrate were washed with a 5% by mass aqueous solution of sulfuric acid before flip-chip bonding to remove the surface oxide film, and the presence or absence of peeling of the TEG chip was confirmed and the conductive resistance value was measured. The results are shown in Table 4.

[0098]

[0099] As shown in Table 4, the TEG bonded bodies using the positive photosensitive adhesive compositions of the examples did not experience TEG chip peeling and had good conduction resistance values ​​(Examples 3-1 to 3-4). In contrast, the TEG bonded bodies using the positive photosensitive adhesive compositions of the comparative examples did not experience TEG chip peeling, but had poor conduction resistance values, suggesting that the resin composition between the electrodes was not sufficiently expelled during flip-chip bonding (Comparative Example 3-1). Furthermore, when the positive photosensitive adhesive composition was not used, TEG chip peeling significantly increased, making it impossible to reproducibly measure resistance values ​​(Comparative Example 3-2).

Claims

1. A material for filling the periphery of an electrode, comprising the following components (A), (B), (C), and (D): Component (A): an alkali-soluble resin which is a polymer having a phenolic hydroxyl group and has a glass transition temperature (Tg) of 60° C. or lower; Component (B): a crosslinking agent; Component (C): a photosensitizer having a quinone diazide; Component (D): a solvent.

2. The electrode periphery filling material according to claim 1, wherein the component (A) is a polymer containing a structural unit derived from a monomer (A2) having a homopolymer Tg of 0° C. or lower.

3. The electrode periphery filling material described in claim 2, wherein the component (A) is an acrylic polymer containing as constituent components structural units derived from a monomer (A1) having a phenolic hydroxyl group and a polymerizable unsaturated group, and a monomer (A2) having a homopolymer Tg of 0°C or lower.

4. The electrode periphery filling material according to claim 3, wherein the monomer (A1) having a phenolic hydroxyl group and a polymerizable unsaturated group is selected from the group consisting of p-hydroxystyrene, m-hydroxystyrene, α-methyl-p-hydroxystyrene, and compounds represented by the following formula (1): In formula (1), P represents a (meth)acrylic group, a (meth)acrylamide group, an N-methyl(meth)acrylamide group, or a maleimide group; １ represents a single bond, or a linear, branched, or cyclic alkylene group having 1 to 12 carbon atoms, or a combination thereof; １ represents a single bond, -O-, -COO-, or -OCO-; d １ represents a substituted or unsubstituted hydroxyphenyl group.

5. The electrode periphery filling material according to any one of claims 3 to 4, wherein the monomer (A2) having a homopolymer Tg of 0°C or less is a compound represented by the following formula (2): In formula (2), R ２ represents a hydrogen atom or a methyl group; ２ represents an oxygen atom or a sulfur atom, b ２ represents a linear, branched, or cyclic alkylene group having 2 to 20 carbon atoms, or a combination thereof, and —CH ２ - may be replaced with an oxygen atom, provided that they are not adjacent to each other. ２ represents a single bond, -O-, -COO-, or -OCO-; d ２ represents a hydrogen atom or a hydroxyl group.

6. An electrode periphery filling material according to any one of claims 1 to 5, wherein the component (A) is an acrylic polymer further containing, as a constituent component, a constituent unit derived from a monomer (A3) containing an aromatic hydrocarbon group represented by the following formula (3): In formula (3), R ３ represents a hydrogen atom or a methyl group; ３ is an oxygen atom, a sulfur atom, -NH-, or -N(CH ３ )-, b ３ represents a single bond, or a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or a combination thereof, and —CH ２ - may be replaced with an oxygen atom, provided that they are not adjacent to each other. ３ is a single bond, -O-, -COO-, -OCO-, -NHCO-, -CONH-, -N(CH ３ )CO-, or -CON(CH ３ )-, d ３ represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms.

7. A filling material for filling the periphery of an electrode according to any one of claims 1 to 6, wherein the amount of component (B) is 5 to 60 parts by mass per 100 parts by mass of component (A).

8. A filling material for filling the periphery of an electrode according to any one of claims 1 to 7, wherein the amount of component (C) is 10 to 100 parts by mass per 100 parts by mass of component (A).

9. An electrode periphery filling material according to any one of claims 1 to 8, further comprising a surfactant as component (E) in an amount of 0.01 to 1.0 part by mass per 100 parts by mass of component (A).

10. A pre-baked film of a material for filling up the periphery of an electrode, obtained by pre-baking a coating film of the material for filling up the periphery of an electrode according to any one of claims 1 to 9.

11. The pre-baked film of the material for filling up the periphery of an electrode according to claim 10, which is patterned.

12. A substrate for mounting an LED element, comprising: an array substrate which serves as a substrate for a micro LED display element; and a pre-baked film of an electrode periphery embedding material provided on the array substrate, the pre-baked film being obtained by pre-baking a coating film of the electrode periphery embedding material described in any one of claims 1 to 9.

13. The LED element mounting substrate according to claim 12, wherein the pre-baked film of the material for embedding around the electrode is patterned in accordance with the mounting position of the LED element.

14. A micro LED display element comprising a substrate for mounting an LED element as described in claim 12 or 13, and an LED element bonded to the substrate for mounting an LED element, wherein an electrode of the LED element is bonded to an electrode for mounting an LED of the substrate for mounting an LED element, and the periphery of the joint between the electrode of the LED element and the electrode for mounting an LED is fixed and protected by a post-bake film of the pre-bake film of the electrode periphery embedding material.

Images