Photosensitive compositions, dry films, cured products, and electronic components

Abstract

To provide a photosensitive composition excellent in low dielectric characteristics and development contrast.SOLUTION: A photosensitive composition contains polyphenylene ether A, polyphenylene ether B, a radical-polymerizable compound, and a photo radical generator. The polyphenylene ethers A, B are each obtained from raw material phenols containing phenols satisfying the condition 1 and phenols satisfying the condition 2. The polyphenylene ether A has a weight average molecular weight of more than 40,000 and 200,000 or less and a content of the phenols satisfying the condition 2 of less than 20 mol% relative to the total raw material phenols. The polyphenylene ether B has a content of the phenols satisfying the condition 2 of 20 mol% or more relative to the total raw material phenols. (condition 1) Having a hydrogen atom at the ortho position and the para position. (condition 2) Having a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive composition, a dry film, a cured product, and an electronic component, each containing a polyphenylene ether. [Background technology]

[0002] 2. Description of the Related Art In electronic components such as semiconductor devices, photolithography is often used to form patterns of insulating layers, protective films, and conductor layers.

[0003] Photolithography is a method in which a layer of a photosensitive composition is formed on a substrate such as a silicon wafer or a copper-clad laminate, and then the layer is irradiated (exposed) to light in a predetermined pattern, and then either the unexposed or exposed areas are dissolved and removed in a developer to form a pattern. Such photolithography methods include a method in which the exposed area is dissolved in a developer, known as a positive type, and a method in which the unexposed area is dissolved in a developer (exposed area becomes insoluble in the developer), known as a negative type.

[0004] Considering such differences in the development process, for example, in order to form a negative pattern with high resolution, the photosensitive composition used is required to have both resistance to dissolution in a developer of the exposed portion and excellent solubility in a developer of the unexposed portion, in other words, a large difference in development speed (development contrast) between the exposed portion and the unexposed portion.

[0005] On the other hand, in insulating materials for electronic components, reduction of dielectric properties such as relative permittivity (Dk) and dielectric loss tangent (Df) has been studied from the viewpoint of suppressing transmission loss for high-frequency band signals. For example, Patent Documents 1 and 2 disclose negative photosensitive resin compositions with reduced dielectric loss tangent that are useful for solder resists, which are permanent protective films for printed wiring boards. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-15890 A [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-68242 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the photosensitive resin compositions such as those described in Patent Documents 1 and 2, there is a limit to the reduction of dielectric properties due to the presence of hydrophilic groups such as carboxyl groups for imparting developability and (meth)acrylate groups for photopolymerization as composition components.

[0008] An object of the present invention is to provide a photosensitive composition having low dielectric properties and excellent development contrast. [Means for solving the problem]

[0009] The present inventors have conducted extensive research, focusing on the solubility of branched polyphenylene ethers in organic solvents and the use of such organic solvents as developers in photolithography. As a result, the present inventors have found that the above-mentioned problems can be advantageously solved by a photosensitive composition containing a combination of two types of polyphenylene ethers obtained from specific raw material phenols and a compound that undergoes radical polymerization with the unsaturated carbon bonds introduced into the polyphenylene ethers, and have thus completed the present invention. Specifically, the present invention is as follows:

[0010] The present invention provides Polyphenylene ether A, Polyphenylene ether B, a compound having an unsaturated carbon bond and a radically polymerizable functional group; a photoradical generator; The polyphenylene ether A and the polyphenylene ether B are obtained from raw material phenols containing phenols that satisfy at least the following condition 1 and phenols that satisfy at least the following condition 2, respectively: the polyphenylene ether A has a weight-average molecular weight of more than 40,000 and not more than 200,000, and the content of phenols satisfying condition 2 relative to the total amount of raw material phenols during synthesis is less than 20 mol %; The polyphenylene ether B is a photosensitive composition in which the content of phenols satisfying condition 2 relative to the total amount of raw material phenols during synthesis is 20 mol % or more. (Condition 1) Contains hydrogen atoms at the ortho and para positions (Condition 2) It has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond.

[0011] The polyphenylene ether B preferably has a weight average molecular weight of 5,000 or more and 40,000 or less. The content ratio of the polyphenylene ether A to the polyphenylene ether B (polyphenylene ether A:polyphenylene ether B) is preferably 25:75 to 75:25 in mass ratio. The functional group capable of radically polymerizing with the unsaturated carbon bond is preferably a thiol group and / or an allyl group.

[0012] The present invention may also be a dry film having a resin layer made of the photosensitive composition.

[0013] The present invention may also be a cured product of the photosensitive composition or the resin layer.

[0014] The present invention may also relate to an electronic component having the cured product. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a photosensitive composition having low dielectric properties and excellent development contrast. DETAILED DESCRIPTION OF THE INVENTION

[0016] The curable composition according to this embodiment is a photosensitive composition used in photolithography.

[0017] Hereinafter, the photosensitive composition may be simply referred to as a "curable composition." Furthermore, in this specification, the term "resin composition" may also be used to mean the "curable composition."

[0018] When the compounds described have isomers, all possible isomers can be used in the present invention unless otherwise specified.

[0019] In the present invention, unless otherwise specified, the term "unsaturated carbon bond" refers to an ethylenic or acetylenic carbon-carbon multiple bond (double bond or triple bond).

[0020] In the present invention, the functional group having an unsaturated carbon bond is not particularly limited, but may be an alkenyl group (e.g., a vinyl group or an allyl group), an alkynyl group (e.g., an ethynyl group), or a (meth)acryloyl group. From the viewpoint of excellent curability, a vinyl group, an allyl group, or a (meth)acryloyl group can be selected. Among these, from the viewpoint of excellent low dielectric properties, an allyl group is preferred. Note that the number of carbon atoms in these functional groups having an unsaturated carbon bond may be, for example, 15 or less, 10 or less, 8 or less, 5 or less, 3 or less, etc.

[0021] In the present invention, phenols that are used as raw materials for polyphenylene ether (PPE) and can become structural units of polyphenylene ether are collectively referred to as "raw material phenols."

[0022] In the present invention, when describing the raw material phenols, expressions such as "ortho position" and "para position" refer to the position of the phenolic hydroxyl group as the reference (ipso position) unless otherwise specified.

[0023] In the present invention, when simply expressed as "ortho position" or the like, it means "at least one of the ortho positions", etc. Therefore, unless a particular contradiction occurs, when simply expressed as "ortho position", it may be interpreted as indicating either one of the ortho positions or as indicating both ortho positions.

[0024] In the present invention, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) of polyphenylene ether are determined by gel permeation chromatography (GPC) using a Shodex K-805L column at a column temperature of 40°C, a flow rate of 1 mL / min, chloroform as the eluent, and polystyrene as the standard.

[0025] In this specification, monohydric phenols are mainly disclosed as the raw material phenols, but polyhydric phenols may also be used as the raw material phenols within the range that does not impair the effects of the present invention.

[0026] In this specification, when the upper and lower limits of a numerical range are separately stated, all combinations of each lower limit and each upper limit are considered to be substantially stated within a consistent range.

[0027] <<<<<<Components of the curable composition>>>>> The curable composition contains polyphenylene ether A, polyphenylene ether B, a compound having an unsaturated carbon bond and a radically polymerizable functional group, and a photoradical generator. The curable composition may also contain other components as needed. Each component will be described below.

[0028] <<<<Polyphenylene Ether A, B>>>> The polyphenylene ethers A and B contained in the curable composition of the present invention are obtained from raw material phenols, each of which contains a phenol satisfying at least the following condition 1 and a phenol satisfying at least the following condition 2. Specifically, examples of phenols satisfying at least the following condition 1 include phenols that satisfy condition 1 but do not satisfy condition 2, or phenols that satisfy both conditions 1 and 2, and examples of phenols that satisfy at least the following condition 2 include phenols that satisfy condition 2 but do not satisfy condition 1, or phenols that satisfy conditions 1 and 2. (Condition 1) Contains hydrogen atoms at the ortho and para positions (Condition 2) It has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond.

[0029] <<<Raw Phenol(s)>>> <<Phenols that meet condition 1>> Phenols that satisfy condition 1 have a hydrogen atom at the ortho position, and therefore, when oxidatively polymerized with phenols, ether bonds can be formed not only at the ipso and para positions but also at the ortho position. Therefore, polyphenylene ether obtained by using such phenols as raw material phenols can form a branched chain structure.

[0030] Specifically, polyphenylene ether obtained from a phenol satisfying condition 1 has a structure in which a part of the structure is branched by benzene rings ether-bonded at least at three positions, i.e., the ipso, ortho, and para positions.

[0031] Such a polyphenylene ether having a branched structure in its skeleton is called a branched polyphenylene ether, and such a branched polyphenylene ether exhibits excellent solubility in organic solvents.

[0032] Examples of phenols that satisfy condition 1 include phenol, o-cresol, m-cresol, o-ethylphenol, m-ethylphenol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, o-tert-butylphenol, m-tert-butylphenol, o-phenylphenol, m-phenylphenol, and 2-dodecylphenol, and one or more of these may be used alone or in combination.

[0033] <<Phenols that meet condition 2>> Phenols that satisfy condition 2 have functional groups containing unsaturated carbon bonds, and therefore polyphenylene ethers obtained using such phenols as raw material phenols have functional groups containing ethylenic or acetylenic carbon-carbon multiple bonds.

[0034] Specifically, a polyphenylene ether obtained from a phenol satisfying condition 2 has, as part of its structure, a functional group containing an unsaturated carbon bond at least at either the meta position or the ortho position of the benzene ring.

[0035] Such polyphenylene ethers having functional groups containing unsaturated carbon bonds in their skeletons are called photosensitive polyphenylene ethers, which exhibit radical polymerization by active species such as radicals.

[0036] Examples of phenols satisfying condition 2 include 2-allyl-6-methylphenol, 2-allyl-6-ethylphenol, 2-allyl-6-phenylphenol, 2-allyl-6-styrylphenol, 2,6-divinylphenol, 2,6-diallylphenol, 2,6-diisopropenylphenol, 2,6-dibutenylphenol, 2,6-diisobutenylphenol, 2,6-diisopentenylphenol, 2-methyl-6-styrylphenol, 2-vinyl-6-methylphenol, and 2-vinyl-6-ethylphenol. Either one type may be used alone, or two or more types may be used together.

[0037] <<Phenols that meet conditions 1 and 2>> Phenols that satisfy conditions 1 and 2 are phenols that have hydrogen atoms at the ortho and para positions and have a functional group containing an unsaturated carbon bond. Polyphenylene ether obtained using such phenols as raw material phenols has a structure in which a part of the structure is branched by benzene rings ether-bonded at at least three positions (ipso, ortho, and para positions) and has a hydrocarbon group containing at least one unsaturated carbon bond as a functional group.

[0038] Examples of phenols that satisfy conditions 1 and 2 include o-vinylphenol, m-vinylphenol, o-allylphenol, m-allylphenol, 3-vinyl-6-methylphenol, 3-vinyl-6-ethylphenol, 3-vinyl-5-methylphenol, 3-vinyl-5-ethylphenol, 3-allyl-6-methylphenol, 3-allyl-6-ethylphenol, 3-allyl-5-methylphenol, and 3-allyl-5-ethylphenol. Either one of these may be used alone, or two or more of these may be used together.

[0039] <<Phenols that do not satisfy either condition 1 or condition 2>> The raw material phenols used in the synthesis of the polyphenylene ether of the present invention may contain phenols that do not satisfy either condition 1 or condition 2, from the viewpoint of adjusting the solubility and radical polymerizability due to the branched structure.

[0040] Examples of such raw material phenols include phenols that have a hydrogen atom at the para position, no hydrogen atom at the ortho position, and no functional group containing an unsaturated carbon bond, such as 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-ethylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-n-butylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, and 2,6-ditolylphenol. These phenols form ether bonds at the ipso and para positions of the benzene ring, resulting in linear polymerization, which reduces branched structures and decreases solubility. Furthermore, the absence of a functional group containing an unsaturated carbon bond reduces radical polymerizability.

[0041] Furthermore, examples of phenols that do not satisfy either condition 1 or condition 2 include phenols that have no hydrogen atoms at the para- and ortho-positions and no functional group containing an unsaturated carbon bond. Such phenols can suppress the polymerization reaction of polyphenylene ether. Such phenols that do not satisfy either condition 1 or condition 2 may be used alone or in combination of two or more.

[0042] <<<Polyphenylene Ether A>>> The polyphenylene ether A in the present invention is obtained from raw material phenols containing at least phenols satisfying condition 1 and at least phenols satisfying condition 2, and is a polyphenylene ether in which the content of phenols satisfying condition 2 relative to the total amount of raw material phenols during synthesis is less than 20 mol % and the weight average molecular weight is more than 40,000 and not more than 200,000.

[0043] Polyphenylene ether A is a polyphenylene ether having a branched structure and functional groups containing unsaturated carbon bonds. However, the content ratio of phenols that satisfy condition 2 relative to the total raw material phenols during synthesis is lower than that of polyphenylene ether B. This prevents the deterioration of dielectric properties due to functional groups containing unsaturated carbon bonds, facilitates the polymerization reaction during synthesis, and has a relatively large weight-average molecular weight, resulting in excellent development resistance.

[0044] From the viewpoint of the balance between the developability of unexposed areas and the development resistance of exposed areas, the polyphenylene ether A preferably has a weight average molecular weight of more than 40,000 and not more than 200,000, and more preferably has a number average molecular weight of 10,000 or more and not more than 30,000, and more preferably has a number average molecular weight of 15,000 or more and not more than 20,000.

[0045] The content of phenols used in the synthesis of polyphenylene ether A that satisfy at least condition 1 can be 1 mol% or more and 99 mol% or less, preferably 5 mol% or more and 30 mol% or less, more preferably 5 mol% or more and 15 mol% or less, and even more preferably 10 mol% based on the total amount of raw material phenols used in the synthesis.

[0046] The content of phenols used in the synthesis of polyphenylene ether A that satisfy at least condition 2 can be less than 20 mol%, preferably 1 mol% or more but less than 20 mol%, more preferably 5 mol% or more but 15 mol% or less, and even more preferably 10 mol%, based on the total amount of raw material phenols used in the synthesis.

[0047] In the synthesis of polyphenylene ether A, phenols that do not satisfy either condition 1 or condition 2 can be used within a range that does not impair the effects of the present invention.

[0048] <<<Polyphenylene Ether B>>> The polyphenylene ether B in the present invention is obtained from raw material phenols containing phenols that at least satisfy condition 1 and phenols that at least satisfy condition 2, and the content of the phenols that satisfy condition 2 relative to the total amount of the raw material phenols during synthesis is 20 mol % or more.

[0049] Polyphenylene ether B is a polyphenylene ether having a branched structure and functional groups containing unsaturated carbon bonds, and the content ratio of phenols satisfying condition 2 relative to the total raw material phenols during synthesis is higher than that of polyphenylene ether A, and since it has many functional groups containing unsaturated carbon bonds, it has excellent radical polymerizability. On the other hand, the polymerization reaction is less likely to proceed due to the phenols satisfying condition 2, and the weight-average molecular weight is relatively small, so it exhibits excellent developability.

[0050] The polyphenylene ether B preferably has a weight-average molecular weight of 5,000 to 40,000, more preferably 10,000 to 20,000, in order to further improve radical polymerizability and developability, and a number-average molecular weight of preferably 5,000 to 20,000, more preferably 5,000 to 12,000.

[0051] The content of the phenols used in the synthesis of polyphenylene ether B, which satisfy at least condition 1, can be 1 mol % or more and 90 mol % or less, preferably 2 mol % or more and 50 mol % or less, and more preferably 5 mol % or more and 20 mol % or less, based on the total amount of raw material phenols used in the synthesis.

[0052] The content of phenols used in the synthesis of polyphenylene ether B that satisfy at least condition 2 can be 20 mol % or more, preferably 20 mol % or more and 90 mol % or less, and more preferably 50 mol % or more and 90 mol % or less, based on the total amount of raw material phenols used in the synthesis.

[0053] In the synthesis of polyphenylene ether B, phenols that do not satisfy either condition 1 or condition 2 can be used within a range that does not impair the effects of the present invention.

[0054] <<<Polyphenylene ether content>>> The content of polyphenylene ether (polyphenylene ether A and polyphenylene ether B) in the curable composition of the present invention is preferably 50 to 90 mass %, more preferably 60 to 80 mass %, based on the total amount of the curable composition excluding volatile components and inorganic fillers. The mass ratio of polyphenylene ether A to polyphenylene ether B in the curable composition (polyphenylene ether A:polyphenylene ether B) is preferably 10:90 to 90:10, more preferably 25:75 to 75:25, and can be 50:50 to 75:25 when improving the development resistance of exposed areas, or 25:75 to 50:50 when improving photoradical polymerizability (photosensitivity) or the developability of unexposed areas.

[0055] <<<Production Method of Polyphenylene Ether A and B>>> The polyphenylene ether A and polyphenylene ether B of the present invention can be produced by a known polyphenylene ether synthesis method, for example, the synthesis method disclosed in International Publication WO2020 / 017570, except that the raw material phenols used are changed.

[0056] The molecular weight of the polyphenylene ether depends on the type of raw material phenol used, but can be adjusted by changing the reaction temperature, reaction time, etc. when synthesizing the polyphenylene ether.

[0057] <<<<<Compounds with unsaturated carbon bonds and radically polymerizable functional groups>>>> The compound having a functional group capable of radical polymerization with an unsaturated carbon bond contained in the curable composition of the present invention (hereinafter also referred to as a radical polymerizable compound) is a compound having two or more functional groups capable of radical polymerization with the unsaturated carbon bond in the polyphenylene ether structure described above. The radical polymerizable functional group can be a known and commonly used functional group, such as a thiol group or an allyl group.

[0058] Examples of radical polymerization compounds include compounds having a thiol group such as trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]isocyanurate, pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), and dipentaerythritol hexakis(3-mercaptopropionate). Examples of compounds having an allyl group include triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, and diallyl 1,4-cyclohexanedicarboxylate.

[0059] <<<Content of compounds with unsaturated carbon bonds and radically polymerizable functional groups>>> The content of the radical polymerizable compound in the curable composition is preferably from 1 to 99% by mass, and more preferably from 10 to 20% by mass, based on the polyphenylene ether in the curable composition.

[0060] <<<<Photoradical generator>>>> The photoradical generator contained in the curable composition of the present invention is a compound that generates radicals by light irradiation (exposure), and the generated radicals cause radical polymerization of the polyphenylene ether or the radical polymerizable compound described above, thereby imparting development resistance to the exposed area.

[0061] As the photoradical generator, known and commonly used photoradical generators can be used, such as benzoin ethers, acetophenones, α-ketols, aromatic sulfonyl chlorides, photoactive oximes, benzoins, benzils, benzophenones, ketals, thioxanthones, and acylphosphine oxides.

[0062] Examples of benzoin ether-based photoradical generators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, and anisoin.

[0063] Examples of acetophenone-based photoradical generators include 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and methoxyacetophenone.

[0064] Examples of the α-ketol photoradical generator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)-phenyl]-2-hydroxy-2-methylpropan-1-one, and the like.

[0065] Examples of aromatic sulfonyl chloride photoradical generators include 2-naphthalenesulfonyl chloride, etc. Examples of photoactive oxime photopolymerization initiators include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)-oxime, etc.

[0066] Benzoin-based photoradical generators include, for example, benzoin.

[0067] Examples of benzyl-based photoradical generators include benzyl.

[0068] Examples of the benzophenone photoradical generator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone.

[0069] An example of the ketal-based photoradical generator is benzyl dimethyl ketal.

[0070] Examples of thioxanthone-based photoradical generators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0071] Examples of the acylphosphine oxide photoradical generator include bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)(2,4,4-trimethylpentyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-n-butylphosphine oxide, bis(2,6-dimethoxybenzoyl)-(2-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, bis(2,6-dimethoxybenzoyl)-(1-methylpropan-1-yl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)phenylphosphine oxide. Bis(2,6-dimethoxybenzoyl)cyclohexylphosphine oxide, Bis(2,6-dimethoxybenzoyl)octylphosphine oxide, Bis(2-methoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, Bis(2-methoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide, Bis(2,6-diethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, Bis(2,6-diethoxybenzoyl)(1-methylpropan-1-yl)phosphine oxide Bis(2,6-dibutoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4-dimethoxybenzoyl)(2-methylpropan-1-yl)phosphine oxide, bis(2,4,6-trimethylbenzoyl)(2,4-dipentoxyphenyl)phosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2 -phenylethylphosphine oxide, bis(2,6-dimethoxybenzoyl)benzylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylpropylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2-phenylethylphosphine oxide, 2,6-dimethoxybenzoylbenzylbutylphosphine oxide, 2,6-dimethoxybenzoylbenzyloctylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diisopropylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-4-methylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,5-diethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,3,5,6-tetramethylphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-di-n-butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)isobutylphosphine oxide, 2,6-dimethytoxybenzoyl-2,4,6-trimethyl Examples include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-2,4-dibutoxyphenylphosphine oxide, 1,10-bis[bis(2,4,6-trimethylbenzoyl)phosphine oxide]decane, and tri(2-methylbenzoyl)phosphine oxide.

[0072] These photoradical generators may be used alone or in combination of two or more.

[0073] <<<Photoradical generator content>>> The content of the photoradical generator in the curable composition is preferably 0.1 to 10 mass %, more preferably 1 to 5 mass %, based on the polyphenylene ether in the curable composition.

[0074] <<<<Solvent>>>> The curable composition of the present invention may contain a solvent as needed depending on the process of blending, application, etc. As the solvent, a solvent capable of dissolving the polyphenylene ether described above is preferred, and examples of solvents that are preferably used include conventionally usable solvents such as chloroform, methylene chloride, and toluene, as well as N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), cyclohexanone, propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), methyl ethyl ketone, and ethyl acetate. These may be used alone or in combination of two or more.

[0075] <<<<Other ingredients>>>> The curable composition of the present invention may contain other components in addition to the above-mentioned components, as long as the effects of the present invention are not impaired. For example, the composition may contain inorganic fillers such as silica, peroxides such as α,α'-bis(t-butylperoxy-m-isopropyl)benzene, resin and polymer components such as polyphenylene ethers other than the above-mentioned polyphenylene ethers, maleimide resins, and styrene-based elastomers, sensitizers, adhesion promoters, surfactants, leveling agents, plasticizers, adhesion agents, colorants, fibers, silane coupling agents, flame retardants, cellulose nanofibers, dispersants, thermosetting catalysts, thickeners, antifoaming agents, antioxidants, rust inhibitors, and adhesion promoters. These components may be blended in appropriate amounts depending on the application, etc. For example, when it is desired to improve the dielectric properties, the content of the peroxide in the curable composition is preferably 0.1 to 10 mass %, and more preferably 1 to 5 mass %, relative to the polyphenylene ether in the curable composition. These components may be used singly or in combination of two or more.

[0076] <<<<<<Dry film>>>>> The dry film has a resin layer made of the curable composition of the present invention on a film material, and is used by laminating the resin layer onto a substrate so that the resin layer is in contact with the substrate.

[0077] The dry film can be produced by uniformly applying the curable composition onto a carrier film (support film) by an appropriate method such as a blade coater, lip coater, comma coater, or film coater, drying the composition to form the resin layer, and preferably laminating a cover film (protective film) thereon. The cover film and the carrier film may be made of the same film material or different films.

[0078] The film materials for the carrier film and the cover film may be any of those known to be used for dry films.

[0079] As the carrier film, for example, a thermoplastic film such as a polyester film made of polyethylene terephthalate or the like having a thickness of 2 to 150 μm is used.

[0080] The cover film may be a polyethylene film, a polypropylene film, or the like, but it is preferable that the adhesive strength with the resin layer is weaker than that of the carrier film.

[0081] The thickness of the resin layer on the dry film is preferably 100 μm or less, more preferably in the range of 5 to 50 μm.

[0082] <<<<<Cured product>>>>> A cured product can be produced using the curable composition or a dry film having a resin layer made of the curable composition.

[0083] The curable composition according to the present embodiment is generally applied to a negative photolithography method. Hereinafter, a method for producing a pattern film, which is a cured product of the curable composition according to the present embodiment, by applying the curable composition according to the present embodiment to a negative photolithography method will be described.

[0084] First, in step 1, a curable composition is applied to a substrate and dried to form a resin layer, or a dry film is laminated onto the substrate to transfer a resin layer made of the curable composition. As a method for applying the curable composition to a substrate, a method conventionally used for applying a curable composition, such as a method using a spin coater, a bar coater, a blade coater, a curtain coater, a screen printing machine, or the like, a spray coating method using a spray coater, or even an inkjet method, can be used.

[0085] Methods for drying the coating film include air drying, heat drying using an oven or a hot plate, vacuum drying, etc. The drying conditions for the coating film are not particularly limited, but natural drying, air drying, or heat drying can be performed at 60 to 130°C for 1 to 30 minutes.

[0086] There are no particular limitations on the substrate, and the substrate can be widely applied to semiconductor substrates such as silicon wafers, wiring boards, and substrates made of various resins and metals.

[0087] Next, in step 2, the resin layer formed on the substrate is irradiated (exposed) to light through a patterned photomask or directly in a pattern. In the method of laminating a dry film, the film material is peeled off and exposed, or, if the film material is light-transmitting, the film material is left on the resin layer and exposed, and then the film material is peeled off. For exposure, light with a wavelength capable of activating the photoradical polymerization initiator is used. Specifically, light with a maximum wavelength in the range of 350 to 410 nm is preferred. Examples of suitable exposure devices include a contact aligner, a mirror projection, a stepper, and a laser direct exposure device.

[0088] Next, in step 3, the resin layer is treated with a developer. This removes the unexposed portions of the resin layer, forming a patterned film. After development, the resin layer may be washed with a rinse solution, if necessary.

[0089] The method used for development can be selected from conventionally known photoresist development methods, such as the rotary spray method, the paddle method, and the immersion method accompanied by ultrasonic treatment.

[0090] The developer may be a solvent that dissolves polyphenylene ether, which is the main component of the curable composition, and is preferably an organic solvent to prevent corrosion of circuits, etc. For example, solvents such as chloroform, methylene chloride, and toluene, as well as N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), cyclohexanone, propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), methyl ethyl ketone, and ethyl acetate may be used alone or in combination of two or more. In order to adjust the development speed, the developer may contain a solvent other than the organic solvents mentioned above, and may contain a suitable amount of a surfactant, etc., as required.

[0091] Examples of the rinse liquid include distilled water, methanol, ethanol, and isopropyl alcohol.

[0092] If necessary, the patterned film may be heated in step 5. The heating temperature is not particularly limited, but may be, for example, at 100 to 220° C. for about 30 to 120 minutes. The atmosphere (gas) used in this step may be air, or an inert gas such as nitrogen or argon.

[0093] <<<<<Electronic Components>>>>> The electronic component has the cured product of the present embodiment described above. The cured product of the present embodiment has excellent dielectric properties and heat resistance, and therefore can be used for various purposes as a material for constituting electronic components.

[0094] Although its use is not particularly limited, preferably, it can be used as an insulating material in electronic components such as high-capacity high-speed communication represented by the fifth-generation communication system (5G) and millimeter-wave radars for automotive ADAS (advanced driving assistance systems).

Example

[0095] <<<Synthesis of polyphenylene ether A>>> <<Synthesis of PPEA-1>> In a 3 L two-necked eggplant flask, 2.6 g of di-μ-hydroxo-bis[(N,N,N’,N’-tetramethylethylenediamine)copper(II)] chloride (Cu / TMEDA) and 3.18 mL of tetramethylethylenediamine (TMEDA) were added and dissolved thoroughly, and oxygen was supplied at 100 ml / min. A raw material solution was prepared by dissolving 89.1 g (90 mol%) of 2,6-dimethylphenol and 10.9 g (10 mol%) of 2-allylphenol, which are raw material phenols, in 1.5 L of toluene. This raw material solution was dropped into the flask and reacted at 40 °C for 10 hours while stirring at a rotation speed of 600 rpm. After the reaction was completed, it was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid and taken out by filtration, and dried at 80 °C for 24 hours to obtain PPEA-1. The number average molecular weight of PPEA-1 was 17,500, and the weight average molecular weight was 192,000.

[0096] <<Synthesis of PPEA-2>> Using the same method as the above-described synthesis method of PPEA-1, except that the reaction time was 8 hours, PPEA-2 was obtained. The number average molecular weight of PPEA-2 was 19,000, and the weight average molecular weight was 84,600.

[0097] <<Synthesis of PPEA-3>> Using the same method as the above-described synthesis method of PPEA-1, except that the reaction time was 6 hours, PPEA-3 was obtained. The number average molecular weight of PPEA-3 was 14,500, and the weight average molecular weight was 50,000.

[0098] <<Synthesis of PPEA-4>> PPEA-4 was obtained in the same manner as the above-described synthesis method of PPEA-1, except that the reaction time was 5 hours. The number-average molecular weight of PPEA-4 was 12,000, and the weight-average molecular weight was 36,000.

[0099] <<<Synthesis of polyphenylene ether B>>> <<Synthesis of PPEB-1>> In a 3-L two-neck eggplant flask, 0.050 g of di-μ-hydroxy-bis[(N,N,N’,N’-tetramethylethylenediamine)copper(II)] chloride (Cu / TMEDA) and 0.0047 g of tetramethylethylenediamine (TMEDA) were added and dissolved thoroughly, and oxygen was supplied at 50 ml / min. A raw material solution was prepared by dissolving 8.8 g (80 mol%) of 2,6-dimethylphenol, which is a raw material phenol, 0.67 g (10 mol%) of 2-allyl-6-methylphenol, and 1. "2 g (10 mol%) of allylphenol in 60 mL of toluene. This raw material solution was added dropwise to the flask and reacted at 40 °C for 18 hours while stirring at a rotation speed of 600 rpm. After completion of the reaction, it was reprecipitated with a mixed solution of 1.2 L of methanol and 4 mL of concentrated hydrochloric acid and taken out by filtration, and dried at 80 °C for 24 hours to obtain PPEB-1. The number-average molecular weight of PPEB-1 was 5,600, and the weight-average molecular weight was 11,500.

[0100] <<Synthesis of PPEB-2>> PPEB-2 was obtained in the same manner as the above-described synthesis method of PPEB-1, except that 5.5 g (50 mol%) of 2,6-dimethylphenol, which is a raw material phenol, was changed to 5.3 g (40 mol%) of 2-allyl-6-methylphenol. The number-average molecular weight of PPEB-2 was 5,400, and the weight-average molecular weight was 11,200.

[0101] <<Synthesis of PPEB-3>> PPEB-3 was obtained by the same method as in the synthesis of PPEB-1, except that the raw material phenols were changed to 1.1 g (10 mol%) of 2,6-dimethylphenol and 10.7 g (80 mol%) of 2-allyl-6-methylphenol. PPEB-2 had a number-average molecular weight of 5,600 and a weight-average molecular weight of 14,000.

[0102] <<<Preparation of curable composition>>> <<Example 1>> 75 parts by weight of PPEA-1, 25 parts by weight of PPEB-3, 3 parts by weight of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (manufactured by IGM Resins, trade name "Omnirad 819") as a photoradical generator, and 20 parts by weight of trimethylolpropane tris(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd., trade name "TMMP") as a thiol group-containing compound were blended, and 400 parts by weight of cyclohexanone was added. The mixture was mixed and stirred at 40°C for 30 minutes to achieve complete dissolution. Next, 2 parts by weight of α,α'-bis(t-butylperoxy-m-isopropyl)benzene (manufactured by NOF Corporation, trade name "Perbutyl P") as a peroxide was blended, and the mixture was stirred with a magnetic stirrer to obtain a varnish of the resin-curable composition of Example 1.

[0103] <<Examples 2 to 10, Comparative Examples 1 to 6>> Curable compositions were prepared in the same manner as in Example 1, except that the components and contents were as shown in Table 1, to obtain varnishes of the curable compositions of Examples 2-13 and Comparative Examples 1-3.

[0104] <<<Evaluation>>> Each curable composition and the cured film obtained by curing each curable composition were evaluated as follows. The evaluation results are shown in Table 1.

[0105] <<Photosensitivity and developability evaluation>> The varnish of each curable composition was applied to a silicon wafer using a spin coater so that the film thickness after drying would be approximately 3 μm, and then dried on a hot plate at 80° C. for 1 minute to form a resin layer made of each curable composition. The silicon wafer with the resin layer formed thereon was then cut into a shape of 2.5 × 15 cm to prepare a test sample for photosensitivity and developability. The resin layer of each test sample was exposed to light with a wavelength of 365 nm at an integrated light dose of 0 (unexposed), 400, 800, 1200, 1600, or 2000 mJ / cm. 2 The test samples were then irradiated with light and then immersed in cyclohexanone for 10 seconds for development. After the developed test samples were dried, the thickness of the remaining resin layer at each exposure dose was measured using a stylus surface profiler. Based on the difference in the remaining film thickness between the unexposed area and the exposed area (development contrast), the feasibility of photolithography was evaluated according to the following criteria. (Evaluation criteria) ◎◎: 800mJ / cm 2 With the above exposure, sufficient development contrast was obtained. ◎: 1200mJ / cm 2 With the above exposure, sufficient development contrast was obtained. ○: 2000mJ / cm 2 With this exposure, sufficient development contrast was obtained. △: 2000mJ / cm 2 A slight development contrast was obtained with an exposure of 1000 nm. ×: The exposed area does not have development resistance, or the unexposed area is not developed, and development contrast is not obtained.

[0106] <<Dielectric properties>> Each curable composition was applied to the shiny surface of 18 μm thick copper foil using an applicator so that the dried film thickness was 30 μm, and then dried in a hot air circulation drying oven at 90°C for 30 minutes. Next, the composition was cured in an inert oven at 200°C for 1 hour, and the copper foil was then etched to obtain a cured product (cured film) made of each composition.

[0107] The cured film was cut into a length of 80 mm and a width of 45 mm and used as a test piece to measure the dielectric constant Dk and dielectric loss tangent Df using the SPDR (Split Post Dielectric Resonator) resonator method. The measuring equipment used was a Keysight Technologies, LLC Vector Network Analyzer E5071C, an SPDR resonator, and a calculation program manufactured by QWED. The conditions were a frequency of 10 GHz and a measurement temperature of 25°C.

[0108] [Table 1]

[0109] [Table 2]

Claims

1. Polyphenylene ether A, Polyphenylene ether B; a compound having an unsaturated carbon bond and a radically polymerizable functional group; a photoradical generator; The polyphenylene ether A and the polyphenylene ether B are polyphenylene ethers synthesized from raw material phenols containing phenols that at least satisfy the following condition 1 and phenols that at least satisfy the following condition 2, respectively: the polyphenylene ether A has a weight-average molecular weight of more than 40,000 and not more than 200,000, and the content of phenols satisfying condition 2 relative to the total amount of raw material phenols during synthesis is less than 20 mol %; the polyphenylene ether B has a weight-average molecular weight of 5,000 or more and 40,000 or less, and the content of phenols satisfying condition 2 relative to the total amount of raw material phenols during synthesis is 20 mol % or more; The photosensitive composition has a content ratio of the polyphenylene ether A to the polyphenylene ether B (polyphenylene ether A:polyphenylene ether B) of 25:75 to 75:25 by mass. (Condition 1) Contains hydrogen atoms at the ortho and para positions (Condition 2) It has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond.

2. 2. The photosensitive composition according to claim 1, wherein the functional group capable of radical polymerization with the unsaturated carbon bond is a thiol group and / or an allyl group.

3. A dry film having a resin layer made of the photosensitive composition according to claim 1 or 2.

4. A cured product of the resin layer of the photosensitive composition according to claim 1 or 2 or the dry film according to claim 3.

5. An electronic part comprising the cured product according to claim 4.

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