Method for producing polyimide precursor, resin composition, method for producing cured product, cured product, and electronic component

Abstract

This method for producing a polyimide precursor comprises: a step for reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to obtain a polyimide precursor containing a polymerizable unsaturated bond; and a step for bringing the polyimide precursor into contact with an acid.

Description

Method for producing polyimide precursors, resin compositions, methods for producing cured products, cured products, and electronic components

[0001] This disclosure relates to a method for producing a polyimide precursor, a resin composition, a method for producing a cured product, a cured product, and an electronic component.

[0002] Polyimide films, which have excellent heat resistance, electrical properties, and mechanical properties, are widely used as resin films for passivation films and interlayer insulating films of electronic components. Polyimide films can be formed, for example, using a polyimide precursor that changes into polyimide by heat curing. Patent Document 1 describes a resin composition that includes a polyamidic acid ester having a photosensitive functional group as a polyimide precursor, as a material capable of forming polyimide films in a patterned manner.

[0003] Patent Document 1: International Publication No. 2008 / 123583

[0004] The polyimide precursor described in Patent Document 1 is synthesized by a condensation method in which a tetracarboxylic acid compound and a diamine are reacted in the presence of an organic dehydrating agent. Polyimide precursors obtained by the condensation method tend to gel when stored at room temperature, and there is room for improvement in storage stability. In view of the above circumstances, one embodiment of the present disclosure aims to provide a method for producing a polyimide precursor with excellent storage stability at room temperature, a resin composition, a method for producing a cured product using the resin composition, a cured product, and an electronic component.

[0005] The specific means for achieving the above objectives are as follows: <1> A method for producing a polyimide precursor, comprising the steps of: reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to obtain a polyimide precursor containing polymerizable unsaturated bonds; and contacting the polyimide precursor with an acid. <2> The method for producing a polyimide precursor according to <1>, wherein the step of contacting the polyimide precursor with an acid comprises adding the acid to a solution obtained by dissolving the polyimide precursor in a good solvent. <3> The method for producing a polyimide precursor according to <1> or <2>, wherein the step of contacting the polyimide precursor with an acid comprises adding the acid to a reaction solution containing the polyimide precursor. <4> The method for producing a polyimide precursor according to any one of <1> to <3>, wherein the step of contacting the polyimide precursor with an acid comprises contacting a solution obtained by dissolving the polyimide precursor in a good solvent with a poor solvent, and at least one of the good solvent or the poor solvent contains an acid. <5> The method for producing a polyimide precursor according to any one of <1> to <4>, wherein the pKa of the acid is 1 or less. <6> A method for producing a polyimide precursor according to any one of <1> to <5>, wherein the acid does not contain fluorine. <7> A resin composition comprising a polyimide precursor which is a reaction product of a tetracarboxylic acid compound and a diamine compound and contains polymerizable unsaturated bonds, and an acid. <8> The resin composition according to <7>, wherein the pKa of the acid is 1 or less. <9> The resin composition according to <7> or <8>, wherein the acid does not contain fluorine. <10> A method for producing a cured product comprising irradiating the resin composition according to any one of <7> to <9> with activated light in a pattern, and heating the resin composition irradiated with activated light. <11> A method for producing a cured product according to <10>, further comprising removing a portion of the resin composition irradiated with activated light. <12> A cured product of the resin composition according to any one of <7> to <9>. <13> An electronic component comprising the cured product according to <12>.

[0006] According to one embodiment of the present disclosure, a method for producing a polyimide precursor with excellent storage stability at room temperature and a resin composition are provided, as well as a method for producing a cured product using the resin composition, a cured product and an electronic component.

[0007] This is a manufacturing process diagram of an electronic component according to one embodiment of the present disclosure.

[0008] The forms for implementing this disclosure are described in detail below. However, this disclosure is not limited to the following embodiments. In this disclosure, the components (including elemental steps, etc.) are not essential unless otherwise explicitly stated. The same applies to numerical values ​​and their ranges, and they do not limit this disclosure. In this disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that are not clearly distinguishable from other processes, if their purpose is achieved. In this disclosure, numerical ranges indicated using "~" include the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple substances corresponding to each component exist in a composition, the content or amount of each component refers to the total content or amount of those multiple substances present in the composition, unless otherwise specified. In this disclosure, the terms "layer" or "film" include cases where the layer or film is formed over the entire region when the region in which it exists is observed, as well as cases where it is formed only on a part of the region. In this disclosure, the thickness of a layer or film is given as the arithmetic mean value obtained by measuring the thickness of five points on the layer or film in question. The thickness of a layer or film can be measured using a micrometer or the like. In this disclosure, if the thickness of a layer or film can be measured directly, it shall be measured using a micrometer. On the other hand, when measuring the thickness of a single layer or the total thickness of multiple layers, it may be measured by observing the cross-section of the object to be measured using an electron microscope.

[0009] In the present disclosure, the term “(meth)acryl group” means “acryl group” and “methacryl group”, the term “(meth)acrylate” means “acrylate” and “methacrylate”, and the term “(meth)acryloyl” means “acryloyl” and “methacryloyl”. In the present disclosure, when a functional group has a substituent, the number of carbon atoms in the functional group means the total number of carbon atoms including the carbon atoms of the substituent. When an embodiment is described with reference to the drawings in the present disclosure, the configuration of the embodiment is not limited to the configuration shown in the drawings. Also, the sizes of the members in each drawing are conceptual, and the relative relationships of the sizes between the members are not limited thereto.

[0010] <Manufacturing Method of Polyimide Precursor> The manufacturing method of the polyimide precursor of the present disclosure includes a step of reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to obtain a polyimide precursor containing a polymerizable unsaturated bond, and a step of bringing the polyimide precursor into contact with an acid.

[0011] The manufacturing method of the polyimide precursor of the present disclosure includes a step of reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to synthesize a polyimide precursor. That is, in the manufacturing method of the present disclosure, the polyimide precursor is synthesized by a condensation method.

[0012] The manufacturing method of the polyimide precursor of the present disclosure further includes a step of bringing the polyimide precursor into contact with an acid. As shown in the examples described later, the polyimide precursor brought into contact with an acid is suppressed in gelation under a room temperature environment compared to the polyimide precursor not brought into contact with an acid, and has excellent storage stability.

[0013] In the manufacturing method of the polyimide precursor of the present disclosure, the method of reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to synthesize a polyimide precursor is not particularly limited, and can be carried out by a known method.

[0014] Specific examples of organic dehydrating agents used in the reaction between tetracarboxylic acid compounds and diamine compounds include dicyclohexylcarbodiimide (DCC), diethylcarbodiimide, diisopropylcarbodiimide, ethylcyclohexylcarbodiimide, diphenylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and 1-cyclohexyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. Among these, dicyclohexylcarbodiimide is preferred from the viewpoint of reactivity. The organic dehydrating agent used in the reaction between tetracarboxylic acid compounds and diamine compounds may be a single agent or a combination of two or more agents.

[0015] In the method for producing a polyimide precursor according to this disclosure, the method for contacting the polyimide precursor with an acid is not particularly limited. Methods for contacting the polyimide precursor with an acid include Method 1, Method 2, or Method 3 described below. The contact between the polyimide precursor and the acid may be carried out by any one of Method 1, Method 2, or Method 3, or by a combination of two or more of these.

[0016] Method 1: A method for preparing a resin composition comprising a polyimide precursor and an acid. Method 2: A method for adding an acid to a reaction solution comprising a polyimide precursor. Method 3: A method comprising contacting a solution obtained by dissolving a polyimide precursor in a good solvent with a poor solvent, wherein at least one of the good solvent or the poor solvent contains an acid.

[0017] In Method 1, as a method of bringing a polyimide precursor into contact with an acid, a resin composition containing the polyimide precursor and the acid is prepared. The components of the resin composition prepared by Method 1 are not particularly limited as long as they contain the polyimide precursor and the acid. From the viewpoint of effectively bringing the polyimide precursor and the acid into contact in the resin composition, it is preferable that the resin composition further contains a solvent that dissolves the polyimide precursor and the acid. The type of the solvent contained in the resin composition is not particularly limited and can be selected from known organic solvents. Specific examples of the organic solvent include esters, ethers, ketones, hydrocarbons, aromatic hydrocarbons, sulfoxides, carbonates, ureas, and the like. The solvent contained in the resin composition may be only one type or a combination of two or more types. When the resin composition contains a solvent, the content of the solvent can be adjusted according to the desired viscosity of the resin composition and the like.

[0018] In Method 2, as a method of bringing a polyimide precursor into contact with an acid, an acid is added to a reaction solution containing the polyimide precursor. In the present disclosure, the "reaction solution containing the polyimide precursor" means a liquid containing a polyimide precursor synthesized from a tetracarboxylic acid compound and a diamine compound and a solvent used in the synthesis step of the polyimide precursor. In Method 2, the type of the acid added to the reaction solution containing the polyimide precursor is not particularly limited. From the viewpoint of effectively bringing the polyimide precursor and the acid into contact in the reaction solution, it is preferable that the acid added to the reaction solution is soluble in the reaction solution. The reaction solution to which the acid is added in Method 2 may be the one used for preparing the resin composition in Method 1 or may not be the one used for preparing the resin composition in Method 1. The reaction solution to which the acid is added in Method 2 may be the one brought into contact with a poor solvent in Method 3 or may not be the one brought into contact with a poor solvent in Method 3.

[0019] In Method 3, a solution obtained by dissolving the polyimide precursor in a good solvent is brought into contact with a poor solvent. Here, at least one of the good solvent or the poor solvent contains an acid. In Method 3, by bringing the solution obtained by dissolving the polyimide precursor in a good solvent into contact with the poor solvent, the polyimide precursor that was dissolved in the good solvent is precipitated in the poor solvent, and the precipitate can be recovered as a purified product of the polyimide precursor. In Method 3, any solvent with high solubility for the polyimide precursor can be used as the good solvent for dissolving the polyimide precursor without particular limitations. Specific examples of good solvents include solvents that may be used in the preparation of the resin composition described above in Method 1. In Method 3, any solvent with low solubility for the polyimide precursor can be used as the poor solvent for dissolving the polyimide precursor without particular limitations. Specific examples of poor solvents include water, polar solvents, or mixed solutions thereof. Specific examples of polar solvents include acetone, isopropanol, ethanol, etc. In Method 3, the type of acid contained in the good solvent or the poor solvent is not particularly limited. From the viewpoint of effectively contacting the polyimide precursor with the acid in a good solvent or poor solvent, it is preferable that the acid contained in the good solvent or poor solvent is soluble in the good solvent or poor solvent.

[0020] In Method 3, the method for contacting the good solvent in which the polyimide precursor is dissolved with the poor solvent is not particularly limited and can be carried out by known methods. For example, a solution obtained by dissolving the polyimide precursor in a good solvent may be added dropwise to the poor solvent. In Method 3, the reaction solution containing the polyimide precursor may be contacted with the poor solvent, or a solution different from the reaction solution containing the polyimide precursor (for example, a solution obtained by dissolving the polyimide precursor recovered from the reaction solution in a good solvent again) may be contacted with the poor solvent.

[0021] The amount of acid to be contacted with the polyimide precursor is not particularly limited and can be selected according to the type of polyimide precursor, acid, or solvent. For example, the amount of acid to be contacted with the polyimide precursor may be 0.1 parts by mass or more, 0.5 parts by mass or more, or 1 part by mass or more per 100 parts by mass of the polyimide precursor. For example, the amount of acid to be contacted with the polyimide precursor may be 50 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less per 100 parts by mass of the polyimide precursor. When the contact between the polyimide precursor and the acid is carried out in a solvent, the temperature of the solvent is not particularly limited. For example, the temperature of the solvent may be selected from the range of 0°C to 50°C.

[0022] Examples of acids used in contact with the polyimide precursor include carboxylic acids, sulfonic acids, thiol compounds, and phenolic compounds. From the viewpoint of affinity to the environment or living organisms, it is preferable that the acid used in contact with the polyimide precursor does not contain fluorine.

[0023] From the viewpoint of effectively improving the storage stability of resin compositions containing polyimide precursors, the acid to be contacted with the polyimide precursor is preferably an acid with a pKa of 5 or less, more preferably an acid with a pKa of 1 or less, and even more preferably an acid with a pKa of less than 0. In this disclosure, the pKa (acid dissociation constant) value of the acid is the value in water at 25°C. The pKa value of polyvalent acids is pK ａ１ This is the value of (first dissociation).

[0024] Among the acids mentioned above, organic acids such as carboxylic acids and sulfonic acids are preferred from the viewpoint of acid strength, and sulfonic acids are preferred from the viewpoint of improving storage stability. Specific examples of carboxylic acids include acetic acid (pKa: 4.8), citric acid (pKa: 3.1), formic acid (pKa: 3.8), gluconic acid (pKa: 3.9), lactic acid (pKa: 3.9), oxalic acid (pKa: 1.3), tartaric acid (pKa: 3.2), acetonedicarboxylic acid (pKa: 3.1), phthalic acid (pKa: 2.9), and benzoic acid (pKa: 4.0). Specific examples of sulfonic acids include methanesulfonic acid (pKa: -2.6), propanesulfonic acid (pKa: 1.9), butanesulfonic acid (pKa: 1.9), p-toluenesulfonic acid (pKa: -2.8), vinylsulfonic acid (pKa: -2.7), benzenesulfonic acid (pKa: 0.7), 10-camphorsulfonic acid (pKa: 1.2), trifluoromethanesulfonic acid (pKa: -14), and fluorosulfonic acid (pKa: -10). Acids with excellent solubility in water and organic solvents may be used as the acid to contact the polyimide precursor. Examples of acids with excellent solubility in water and organic solvents include p-toluenesulfonic acid and benzenesulfonic acid. The acid to contact the polyimide precursor may be one type or two or more types.

[0025] (Polyimide Precursors) In this disclosure, "polyimide precursor" means at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyamic acid salt, and polyamic acid amide. Polyamic acid esters and polyamic acid amides are compounds in which at least some of the hydrogen atoms of the carboxyl groups in a polyamic acid are replaced with monovalent organic groups, and polyamic acid salts are compounds in which at least some of the carboxyl groups in a polyamic acid form a salt structure with a basic compound.

[0026] The polyimide precursor undergoes an imidation reaction upon heating to form a polyimide resin. In this disclosure, "polyimide resin" means a polymer compound that contains an imide skeleton in all or part of its resin skeleton.

[0027] In this disclosure, "tetracarboxylic acid compound" means a tetracarboxylic acid (which may also be a tetracarboxylic acid dianhydride) or a derivative thereof. Examples of tetracarboxylic acid derivatives include compounds in which some of the hydrogen atoms in the carboxyl groups of a tetracarboxylic acid are replaced with monovalent organic groups. Specific examples of tetracarboxylic acid derivatives include tetracarboxylic acid esters such as tetracarboxylic acid diesters and tetracarboxylic acid monoesters.

[0028] Polyimide precursors contain polymerizable unsaturated bonds. Polyimide precursors containing polymerizable unsaturated bonds are suitably used, for example, when forming patterned films of polyimide resin. Examples of polymerizable unsaturated bonds include carbon-carbon double bonds contained in functional groups such as vinyl groups, acryloyl groups, and methacryloyl groups. Polyimide precursors containing polymerizable unsaturated bonds can be obtained, for example, by reacting a tetracarboxylic acid compound into which polymerizable unsaturated bonds have been introduced with a diamine compound.

[0029] The polyimide precursor may have a structural unit represented by the following general formula (1).

[0030]

[0031] In general formula (1), X represents a tetravalent organic group, Y represents a divalent organic group, and R １ and R ２ Each of these independently represents a hydrogen atom or a monovalent organic group. In general formula (1), X is a structure derived from a tetracarboxylic acid compound, and Y is a structure derived from a diamine.

[0032] In general formula (1), the structure of the tetravalent organic group represented by X is not particularly limited. For example, the number of carbon atoms in the tetravalent organic group may be 4 to 25, 6 to 20, or 6 to 12. In general formula (1), the tetravalent organic group represented by X may be one type or two or more types.

[0033] The tetravalent organic group may contain an aromatic ring. Examples of the aromatic ring include an aromatic hydrocarbon group (for example, the number of carbon atoms constituting the aromatic ring is 6 to 20), an aromatic heterocyclic group (for example, the number of atoms constituting the heterocyclic ring is 5 to 20), etc., and an aromatic hydrocarbon group is preferred. Examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, a phenanthrene ring, etc., and a benzene ring is preferred. When the tetravalent organic group contains an aromatic ring, each aromatic ring may have a substituent or may be unsubstituted. Examples of the substituent of the aromatic ring include an alkyl group, a fluorine atom, a halogenated alkyl group, a hydroxyl group, an amino group, etc.

[0034] When the tetravalent organic group contains a benzene ring, the number of benzene rings is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. When the tetravalent organic group contains two or more benzene rings, each benzene ring may be linked by a single bond or may be linked via a linking group. Specific examples of the linking group include an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (—O—), a sulfide bond (—S—), a silylene bond (—Si(R Ａ )) ２ —; the two Rs Ａ each independently represent a hydrogen atom, an alkyl group or a phenyl group.)), a siloxane bond (—O—(Si(R Ｂ )) ２ —O—)); the two Rs ｎ each independently represent a hydrogen atom, an alkyl group or a phenyl group, and n represents an integer of 1 or 2 or more.)), and a composite linking group formed by combining two or more of these linking groups. Further, a 5-membered or 6-membered ring containing a linking group may be formed between two benzene rings.

[0035] ​​At least a portion of the tetravalent organic group may or may not contain a biphenyl structure. In this disclosure, "biphenyl structure" means a structure in which two benzene rings are joined by a single bond. The benzene rings constituting the biphenyl structure may or may not have substituents. If the tetravalent organic group contains a biphenyl structure, the biphenyl structure may or may not have substituents, and it is preferable that it is not substituted.

[0036] The structure of the tetravalent organic group containing the biphenyl structure may also be represented by the following general formula (X1).

[0037]

[0038] In the general formula (X1), each R independently represents a monovalent substituent, n represents the number of R selected from 0 to 3, and * represents the bond position. If the structure represented by the general formula (X1) has two or more monovalent substituents, the two or more monovalent substituents may be the same or different.

[0039] Examples of monovalent substituents include alkyl groups, fluorine atoms, alkyl halides, hydroxyl groups, and amino groups. The alkyl group or alkyl halide preferably has 1 to 5 carbon atoms, more preferably 1 to 3, and even more preferably 1 carbon atom. Specific examples of alkyl groups include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, and t-butyl groups. Specific examples of alkyl halides include trifluoroalkyl groups such as trifluoromethyl groups. The monovalent substituent is preferably an unsubstituted alkyl group, and more preferably an unsubstituted methyl group.

[0040] The number of R represented by n in the general formula (X1) is preferably 0 or 1, and more preferably 0, independently.

[0041] In general formula (1), the structure of the divalent organic group represented by Y is not particularly limited. For example, the number of carbon atoms in the divalent organic group may be 4 to 25, 6 to 20, or 6 to 12. In general formula (1), the divalent organic group represented by Y may be one type or two or more types.

[0042] The divalent organic group may include an aromatic ring. Examples of aromatic rings include aromatic hydrocarbon groups (for example, groups with 6 to 20 carbon atoms) and aromatic heterocyclic groups (for example, groups with 5 to 20 atoms). Aromatic hydrocarbon groups are preferred. Examples of aromatic hydrocarbon groups include benzene rings, naphthalene rings, and phenanthrene rings. Benzene rings are preferred. When the divalent organic group includes an aromatic ring, each aromatic ring may have substituents or may be unsubstituted. Examples of substituents on aromatic rings include alkyl groups, fluorine atoms, alkyl halides, hydroxyl groups, and amino groups.

[0043] When a divalent organic group contains a benzene ring, the number of benzene rings is preferably one to four, more preferably one to three, and even more preferably one or two. When a divalent organic group contains two or more benzene rings, each benzene ring may be linked by a single bond or by a linking group. Specifically, linking groups include alkylene groups, halogenated alkylene groups, carbonyl groups, sulfonyl groups, ether bonds (-O-), sulfide bonds (-S-), and silylene bonds (-Si(R)). Ａ ) ２ -; Two R's Ａ Each of these independently represents a hydrogen atom, an alkyl group, or a phenyl group. ), siloxane bond (-O-(Si(R Ｂ ) ２ -O-) ｎ ; Two R's Ｂ Each of these independently represents a hydrogen atom, an alkyl group, or a phenyl group, and n represents an integer of 1 or more. Examples include ), and composite linking groups formed by combining two or more of these linking groups. In addition, a five-membered ring or a six-membered ring containing a linking group may be formed between two benzene rings.

[0044] At least a portion of the divalent organic group may or may not contain a biphenyl structure. If the divalent organic group contains a biphenyl structure, the biphenyl structure may or may not have substituents, but it is preferable that it has substituents. The substituents are preferably unsubstituted alkyl groups, and more preferably unsubstituted methyl groups.

[0045] The structure of the divalent organic group containing the biphenyl structure may be represented by the following general formula (Y1).

[0046]

[0047] In the general formula (Y1), each R independently represents a monovalent substituent, n represents the number of R selected from 0 to 4, and * represents the bond position. If the structure represented by the general formula (Y1) has two or more monovalent substituents, the two or more monovalent substituents may be the same or different.

[0048] Examples of monovalent substituents include alkyl groups, fluorine atoms, alkyl halides, hydroxyl groups, and amino groups. The alkyl group or alkyl halide preferably has 1 to 5 carbon atoms, more preferably 1 to 3, and even more preferably 1 carbon atom. Specific examples of alkyl groups include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, and t-butyl groups. Specific examples of alkyl halides include trifluoroalkyl groups such as trifluoromethyl groups. The monovalent substituent is preferably an unsubstituted alkyl group, and more preferably an unsubstituted methyl group.

[0049] The number of R atoms represented by n in general formula (Y1) is preferably 1 or 2, and more preferably 1, independently. When n in general formula (Y1) is 1 or more, the position of at least one R atom is preferably the ortho position relative to the bonding position of the two benzene rings constituting the biphenyl structure. That is, the structure represented by general formula (Y1) is preferably the structure represented by the following general formula (Y1').

[0050]

[0051] In the general formula (Y1'), each R independently represents a monovalent substituent, n represents the number of R selected from 0 to 3, and * represents the bond position. In the general formula (Y1'), each n is preferably 0 or 1, and more preferably 0. That is, the structure represented by the general formula (Y1) is preferably the structure represented by the following general formula (Y1'').

[0052]

[0053] In the general formula (Y1''), each R independently represents a monovalent substituent, and * represents a bond position.

[0054] The structures of X and Y in general formula (1) can be adjusted by selecting the type of compound used as a raw material for the polyimide precursor. For example, by using a tetracarboxylic acid compound having the structure represented by X and a diamine compound having the structure represented by Y as raw materials for the polyimide precursor, polyimide precursors having the structures represented by X and Y, respectively, can be obtained.

[0055] By using 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) or its derivatives as a raw material for the polyimide precursor, a polyimide precursor containing a tetravalent organic group X1 as X in general formula (1) can be obtained.

[0056] From the viewpoint of adjusting the physical properties of the cured product (e.g., resin film) obtained using the polyimide precursor, 4,4'-oxydiphthalic anhydride (ODPA) or a derivative thereof may be further used as a raw material for the polyimide precursor.

[0057] By using 4,4'-diaminobiphenyl (also known as benzidine) or its derivatives as a raw material for the polyimide precursor, a polyimide precursor containing a divalent organic group Y1 as Y in general formula (1) can be obtained. Specifically, examples of derivatives of 4,4'-diaminobiphenyl include 2,2'-dimethylbiphenyl-4,4'-diamine (DMAP).

[0058] From the viewpoint of adjusting the physical properties of the cured product (e.g., resin film) obtained using the polyimide precursor, at least one selected from the group consisting of p-phenylenediamine (PPD) or its derivatives, 4,4'-diaminodiphenyl ether or its derivatives, and 1,3-bis(3-aminophenoxy)benzene or its derivatives may be used as a raw material for the polyimide precursor.

[0059] The polymerizable unsaturated bond contained in the polyimide precursor is R in general formula (1). １ or R ２ It may be in a state in which it is contained in at least one of the monovalent organic groups represented by general formula (1). If there are multiple types of structural units represented by general formula (1), the R of each structural unit １ and R ２ The combinations may be the same or different. Also, R included in the same structural unit １ and R ２ The combinations may be the same or different. For example, R １ and R ２ One of them may be a hydrogen atom and the other a monovalent organic group, R １ and R ２ Each of these may be a hydrogen atom, R １ and R ２ Each of these may be a monovalent organic group.

[0060] R １ or R ２ The monovalent organic group represented by is preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms, or a monovalent organic group containing a polymerizable unsaturated bond. Specific examples of aliphatic hydrocarbon groups having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups, with ethyl, isobutyl, and t-butyl groups being preferred. Examples of polymerizable unsaturated bonds include carbon-carbon double bonds contained in functional groups such as vinyl, acryloyl, and methacryloyl groups. The monovalent organic group containing a polymerizable unsaturated bond is preferably a group represented by the following general formula (2).

[0061]

[0062] In general formula (2), R ３ ~R ５ Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, R ｘ This represents a divalent linking group.

[0063] R in general formula (2) ３ ~R ５ The aliphatic hydrocarbon group represented by has 1 to 3 carbon atoms, preferably 1 or 2. ３ ~R ５ Specific examples of the aliphatic hydrocarbon group represented by include methyl group, ethyl group, n-propyl group, isopropyl group, etc., with methyl group being preferred.

[0064] R in general formula (2) ３ ~R ５ As for combinations, R ３ and R ４ is a hydrogen atom, R ５ A combination in which is a hydrogen atom or a methyl group is preferred. That is, the monovalent organic group represented by general formula (2) preferably contains an acryloyl group or a methacryloyl group.

[0065] R in general formula (2) ｘ The linking group is a divalent linking group, preferably a hydrocarbon group having 1 to 10 carbon atoms. Examples of hydrocarbon groups having 1 to 10 carbon atoms include linear or branched alkylene groups. ｘ The number of carbon atoms is preferably 1 to 10, more preferably 2 to 5, and even more preferably 2 or 3.

[0066] The group represented by general formula (2) is preferably the group represented by the following general formula (2').

[0067]

[0068] In general formula (2'), R ３ ~R ５ Each of these independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and q represents an integer from 1 to 10.

[0069] In general formula (2'), q is an integer from 1 to 10, preferably from 2 to 5, and more preferably 2 or 3.

[0070] Polymerizable unsaturated bond is R in general formula (1) １ or R ２ In the case where it is contained in at least one of the monovalent organic groups represented by , all R contained in the polyimide precursor １ and R ２ Of these, the proportion of monovalent organic groups containing polymerizable unsaturated bonds is preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. The upper limit of the above content is not particularly limited and may be 100 mol%, 95 mol%, or 90 mol%. In some embodiments, the above content may be greater than 0 mol% and less than 60 mol%.

[0071] Polymerizable unsaturated bond is R in general formula (1) １ or R ２ In the case where it is contained in at least one of the monovalent organic groups represented by , all R contained in the polyimide precursor １ and R ２ Of these, the proportion of the group represented by general formula (2) is preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. The upper limit of the above content is not particularly limited and may be 100 mol%. In some embodiments, the above content may be greater than 0 mol% and less than 60 mol%.

[0072] In general formula (1), -COOR １ The group and the -CONH- group are preferably in the ortho position relative to each other, and -COOR ２ It is preferable that the group and the -CO- group are in the ortho position relative to each other.

[0073] A polymerizable polyimide precursor having unsaturated bonds can be obtained, for example, by the following methods (a) or (b): (a) by reacting a tetracarboxylic dianhydride with a compound represented by R-OH to synthesize a diester derivative, and then condensing the diester derivative with a diamine compound; (b) by reacting a tetracarboxylic dianhydride with a diamine compound to synthesize a polyamic acid, and then introducing an ester group by reacting the polyamic acid with a compound represented by R-OH.

[0074] By using a compound in which R contains a polymerizable unsaturated bond as at least a portion of the compound represented by R-OH used in the above method, １ or R ２ A polyimide precursor can be obtained in which at least one part of the monovalent organic group represented by contains polymerizable unsaturated bonds.

[0075] Compounds represented by R-OH have the R group represented by general formula (2). ｘ The compound may be one in which a hydroxyl group is bonded to the group, or one in which a hydroxyl group is bonded to the terminal methylene group of the group represented by general formula (2'). Specific examples of compounds represented by R-OH include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, and 4-hydroxybutyl methacrylate, among which 2-hydroxyethyl methacrylate (HEMA) and 2-hydroxyethyl acrylate (HEA) are preferred.

[0076] There are no particular restrictions on the molecular weight of the polyimide precursor; for example, it is preferably 10,000 to 200,000 in weight-average molecular weight, more preferably 10,000 to 100,000, and even more preferably 15,000 to 60,000. The weight-average molecular weight of the polyimide precursor can be measured, for example, by gel permeation chromatography and can be determined by conversion using a standard polystyrene calibration curve.

[0077] <Resin Composition> The resin composition of this disclosure comprises a polyimide precursor which is a reaction product of a tetracarboxylic acid compound and a diamine compound and contains polymerizable unsaturated bonds, and an acid.

[0078] As shown in the examples described later, a resin composition containing an acid along with a polyimide precursor containing polymerizable unsaturated bonds exhibits suppressed gelation at room temperature and superior storage stability compared to a resin composition containing a polyimide precursor containing polymerizable unsaturated bonds but without acid.

[0079] Details and preferred embodiments of the polyimide precursor contained in the resin composition of this disclosure are the same as details and preferred embodiments of the polyimide precursor produced by the method for producing the polyimide precursor described above. Details and preferred embodiments of the acid contained in the resin composition of this disclosure are the same as details and preferred embodiments of the acid used in the method for producing the polyimide precursor described above.

[0080] The polyimide precursor contained in the resin composition of this disclosure may be one type or two or more types. The polyimide precursor contained in the resin composition of this disclosure may be a polyimide precursor containing polymerizable unsaturated bonds, or a combination of a polyimide precursor containing polymerizable unsaturated bonds and a polyimide precursor not containing polymerizable unsaturated bonds.

[0081] In the resin composition of this disclosure, the proportion of the polyimide precursor containing polymerizable unsaturated bonds may be 50% to 100% by mass, 70% to 100% by mass, or 80% to 100% by mass of the total polyimide precursor contained in the resin composition.

[0082] From the viewpoint of ease of handling of the resin composition, it is preferable that the resin composition further contains a solvent. From the viewpoint of storage stability at room temperature, it is even more preferable that the polyimide precursor and acid are dissolved in the solvent.

[0083] The type of solvent included in the resin composition is not particularly limited, and any known organic solvent can be used. Specific examples of organic solvents include those used in the above-described method for producing the polyimide precursor. The resin composition may contain only one solvent or a combination of two or more solvents. The amount of solvent included in the resin composition can be adjusted according to the desired viscosity of the resin composition.

[0084] The amount of acid contained in the resin composition of this disclosure is not particularly limited and can be selected depending on the type of polyimide precursor, acid, or solvent. For example, the amount of acid contained in the resin composition may be 0.1 parts by mass or more, 0.5 parts by mass or more, or 1 part by mass or more per 100 parts by mass of the polyimide precursor. For example, the amount of acid contained in the resin composition may be 50 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less per 100 parts by mass of the polyimide precursor.

[0085] (Photopolymerization Initiator) The resin composition of this disclosure may contain a photopolymerization initiator. The photopolymerization initiator may be used alone or in combination of two or more. From the viewpoint of excellent exposure sensitivity and suppression of void generation during bonding, it is preferable to include an oxime-based photopolymerization initiator. Specific examples of oxime-based photopolymerization initiators include 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, and 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime. Examples include 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyloxime), O-acetyl-1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazole-3-yl]ethanone oxime, 1-[4-(4-hydroxyethyloxy-phenylthio)phenyl]-1,2-propanedione-2-(O-acetyloxime), etc.

[0086] If the resin composition of this disclosure contains a photopolymerization initiator, the total amount of the photopolymerization initiator is preferably 0.1 to 20 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 5 to 20 parts by mass, per 100 parts by mass of the resin component.

[0087] (Stabilizers) The resin compositions of this disclosure may contain stabilizers. The stabilizers may be used alone or in combination of two or more types.

[0088] Examples of stabilizers include p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, orthodinitrobenzene, paradinitrobenzene, metadinitrobenzene, phenanthaquinone, N-phenyl-2-naphthylamine, cuperone, 2,5-tholquinone, tannic acid, parabenzylaminophenol, nitrosamines, azo compounds, hindered amine compounds, and hindered phenol compounds.

[0089] If the resin composition of this disclosure contains a stabilizer, the amount of the stabilizer is preferably 0.05 parts by mass to 1.0 parts by mass, and more preferably 0.1 parts by mass to 0.8 parts by mass, per 100 parts by mass of the resin component.

[0090] (Crosslinking agent) The resin composition of this disclosure may contain a crosslinking agent. The crosslinking agent may be used alone or in combination of two or more types. By including a crosslinking agent in the resin composition, the heat resistance, mechanical properties, and chemical resistance of the cured product formed from the resin composition can be improved. The crosslinking agent may be used alone or in combination of two or more types.

[0091] Examples of crosslinking agents include compounds having two or more polymerizable unsaturated bonded groups (hereinafter also referred to as functional groups). From the viewpoint of polymerization reactivity, (meth)acryloyl groups and vinyl groups are preferred as functional groups, with (meth)acryloyl groups being more preferred.

[0092] Examples of bifunctional crosslinking agents include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane diacrylate, tricyclodecanedimethanol diacrylate, and tricyclodecanedimethanol dimethacrylate.

[0093] Examples of trifunctional crosslinking agents include trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, tris-(2-acryloxyethyl) isocyanurate, and tris-(2-methacryloxyethyl) isocyanurate.

[0094] Examples of crosslinking agents with four or more functions include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and tetrakisacrylate methanetetrayltetrakis (methyleneoxyethylene).

[0095] If the resin composition of this disclosure contains a crosslinking agent, the amount of the crosslinking agent is preferably 1 to 50 parts by mass, more preferably 3 to 50 parts by mass, and even more preferably 5 to 40 parts by mass, per 100 parts by mass of the resin component.

[0096] (Sensitizer) The resin composition of this disclosure may contain a sensitizer. The sensitizer may be used alone or in combination of two or more. Specific examples of sensitizers include benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, 4,4'-bis(diethylamino)benzophenone, o-methyl benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone, and other benzophenone derivatives.

[0097] If the resin composition of this disclosure contains a sensitizer, the amount of sensitizer is preferably 0.01 to 3 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the resin component.

[0098] (Ultraviolet absorber) The resin composition of this disclosure may contain an ultraviolet absorber. When the resin composition contains an ultraviolet absorber, crosslinking of unexposed areas due to diffuse reflection during exposure tends to be suppressed.

[0099] Examples of UV absorbers include benzotriazole compounds, salicylate ester compounds, benzophenone compounds, diphenyl acrylate compounds, cyanoacrylate compounds, diphenylcyanoacrylate compounds, benzothiazole compounds, azobenzene compounds, polyphenol compounds, and nickel complex salt compounds. UV absorbers may be used individually or in combination of two or more.

[0100] If the resin composition of this disclosure contains an ultraviolet absorber, the amount of ultraviolet absorber is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.2 to 2 parts by mass, per 100 parts by mass of the resin component.

[0101] (Rust Inhibitor) The resin composition of this disclosure may contain a rust inhibitor from the viewpoint of suppressing the modification (corrosion, discoloration, etc.) of metals that come into contact with the resin composition. Examples of rust inhibitors include azole compounds and purine derivatives. The rust inhibitor may be used alone or in combination of two or more types.

[0102] Specific examples of azole compounds include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-t-butyl-5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, phenyltriazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, hydroxyphenyltriazole, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 1H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benz Examples include zotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, and 1-methyl-1H-tetrazole.

[0103] Specific examples of purine derivatives include purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, 2,6-diaminopurine, 9-methyladenine, 2-hydroxyadenine, 2-methyladenine, 1-methyladenine, N-methyladenine, N,N-dimethyladenine, 2-fluoroadenine, 9-(2-hydroxyethyl)adenine, guanine oxime, N-(2-hydroxyethyl)adenine, and 8-amino Examples include adenine, 6-amino-8-phenyl-9H-purine, 1-ethyladenine, 6-ethylaminopurine, 1-benzyladenine, N-methylguanine, 7-(2-hydroxyethyl)guanine, N-(3-chlorophenyl)guanine, N-(3-ethylphenyl)guanine, 2-azaadenine, 5-azaadenine, 8-azaadenine, 8-azaguanine, 8-azapurine, 8-azaxanthine, 8-azahypoxanthine, and their derivatives.

[0104] If the resin composition of this disclosure contains a rust inhibitor, the amount of rust inhibitor is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the resin component.

[0105] (Thermal Radical Generator) The resin composition of this disclosure may contain a thermal radical generator from the viewpoint of improving the physical properties of the cured product. The thermal radical generator may be used alone or in combination of two or more types.

[0106] Specific examples of thermal radical generators include ketone peroxides such as methyl ethyl ketone peroxide, peroxyketals such as 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, and 1,1-di(t-butylperoxy)cyclohexane, hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide, and diamine peroxides such as dicumyl peroxide and di-t-butyl peroxide. Examples include diacyl peroxides such as lucyl peroxide, dilauroyl peroxide, and dibenzoyl peroxide; peroxydicarbonates such as di(4-t-butylcyclohexyl) peroxydicarbonate and di(2-ethylhexyl) peroxydicarbonate; peroxyesters such as t-butyl peroxy-2-ethylhexanoate, t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxybenzoate, and 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate; and bis(1-phenyl-1-methylethyl) peroxide. The thermal polymerization initiator may be used alone or in combination of two or more.

[0107] If the resin composition of this disclosure contains a thermal radical generator, the amount of the thermal radical generator may be 0.1 to 20 parts by mass, 1 to 15 parts by mass, or 1 to 10 parts by mass per 100 parts by mass of the resin component.

[0108] (Antioxidant) The resin composition of this disclosure may contain an antioxidant. The inclusion of an antioxidant in the resin composition of this disclosure can suppress oxidation of electrodes during insulation reliability testing. The antioxidant may be used alone or in combination of two or more types.

[0109] Specific examples of antioxidants include hindered phenol compounds, N,N'-bis[2-[2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethylcarbonyloxy]ethyl]oxamide, N,N'-bis-3-(3,5-di-tert-butyl-4'-hydroxyphenyl)propionylhexamethylenediamine, 1,3,5-tris(3-hydroxy-4-tert-butyl-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid. Antioxidants may be used individually or in combination of two or more.

[0110] If the resin composition of this disclosure contains an antioxidant, the amount of the antioxidant is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the resin component.

[0111] <Method for manufacturing a cured product> The method for manufacturing a cured product according to the present disclosure includes irradiating the resin composition according to the present disclosure with active light in a patterned manner (hereinafter also referred to as exposure treatment) and heating the resin composition that has been irradiated with active light (hereinafter also referred to as heat treatment).

[0112] The resin composition used in the above method contains a polyimide precursor containing polymerizable unsaturated bonds. Therefore, when the resin composition is irradiated with active light, a polymerization reaction occurs in the unsaturated bonds contained in the polyimide precursor, reducing its solubility in the developer.

[0113] In the exposure treatment, the resin composition is irradiated with active light. The conditions for the exposure treatment are not particularly limited as long as conditions are met for polymerization of the unsaturated bonds contained in the polyimide precursor. Examples of active light used in the exposure treatment include ultraviolet light such as i-rays, visible light, and radiation, with i-rays being preferred. From the viewpoint of promoting polymerization of the unsaturated bonds contained in the polyimide precursor, it is preferable to perform the exposure treatment of the resin composition on a layer of the resin composition formed on a substrate (hereinafter also referred to as the resin composition layer). The method for forming the resin composition layer on the substrate is not particularly limited. For example, the resin composition may be applied to the substrate by a spin coating method. After applying the resin composition, a drying treatment may be performed to remove the solvent contained in the resin composition layer. The drying treatment may be, for example, a treatment in which the resin composition layer is heated in an oven, on a hot plate, etc.

[0114] The substrates include glass substrates, semiconductor substrates such as Si substrates (silicon wafers), and TiO2. ２ Substrate, SiO ２ Examples include metal oxide insulating substrates, silicon nitride substrates, copper substrates, and copper alloy substrates.

[0115] The thickness of the resin composition layer formed on the substrate is not particularly limited and can be selected considering the thickness of the final cured product. The thickness of the resin composition layer immediately after coating the substrate may be selected from, for example, a range of 5 μm to 100 μm.

[0116] In the exposure treatment, the resin composition is irradiated with activated light in a patterned manner. By performing the exposure treatment in a patterned manner, the polymerization reaction of unsaturated bonds contained in the polyimide precursor proceeds in the areas of the resin composition irradiated with activated light (exposed areas), making them difficult to remove with the developer. In the areas of the resin composition not irradiated with activated light (unexposed areas), the polymerization reaction of unsaturated bonds contained in the polyimide precursor does not proceed, and a state that is easily removed by the developer is maintained.

[0117] The method of this disclosure may include removing a portion of the resin composition irradiated with active light (hereinafter also referred to as the developing step). In the developing step, for example, the unexposed portion of the resin composition after exposure treatment is removed by contacting it with a developer. Therefore, by performing exposure treatment on the resin composition in a pattern and then performing the developing step, a resin composition can be obtained in which the exposed portions remain in a pattern. The developer can be used without particular limitations as long as it is capable of removing the unexposed portion of the resin composition. For example, an organic solvent capable of dissolving the unexposed portion of the resin composition can be used.

[0118] In the heat treatment, the resin composition that has undergone exposure treatment and, if necessary, development treatment is heated. The heat treatment causes imidization to occur as the sites introduced into the polyimide precursor via ester bonds are removed. The conditions for the heat treatment are not particularly limited, as long as they allow imidization of the polyimide precursor to occur and form a polyimide resin. For example, the heat treatment temperature can be selected from the range of 80°C to 450°C. From the viewpoint of sufficiently advancing the imidization of the polyimide precursor to obtain a cured product with excellent heat resistance, the heat treatment temperature is preferably 100°C or higher, more preferably 150°C or higher, and even more preferably 200°C or higher. From the viewpoint of suppressing deterioration of the cured product obtained by the heat treatment, the heat treatment temperature is preferably 400°C or lower, more preferably 350°C or lower, and even more preferably 300°C or lower.

[0119] The duration of the heat treatment is not particularly limited, but it is preferably 5 hours or less, and more preferably 30 minutes to 3 hours. The atmosphere for the heat treatment may be air or an inert atmosphere such as nitrogen, but from the viewpoint of suppressing oxidation of the cured product obtained from the resin composition, it is preferable to use an inert atmosphere such as nitrogen.

[0120] <Cured Product> The cured product of this disclosure is a cured product of the resin composition of this disclosure. The resin composition of this disclosure contains a polyimide precursor. Therefore, a cured product of the resin composition can be obtained by heat-treating the resin composition of this disclosure. More specifically, by heat-treating the resin composition, imidization (dehydration and ring-closing reaction) of the polyimide precursor occurs, and the resin composition can be cured by changing it into a polyimide resin. That is, the cured product of this disclosure contains polyimide, which is an imidized product of the polyimide precursor.

[0121] Furthermore, the polyimide precursor contained in the resin composition of this disclosure contains polymerizable unsaturated bonds. Therefore, the cured product of this disclosure may be a patterned cured product (patterned cured product) obtained by performing a patterned exposure treatment and a development treatment on the resin composition before heat treatment. The cured product of this disclosure may be in the form of a film. If the cured product is in the form of a film, its thickness is not particularly limited and may be selected from, for example, a range of 1 μm to 30 μm.

[0122] The cured product of this disclosure can be used, for example, as a resin film used in electronic components. Specific examples of resin films include passivation films, buffer coat films, interlayer insulating films, cover coat layers, and surface protective films.

[0123] <Electronic Components> The electronic components of this disclosure include the cured products of this disclosure as described above. The electronic components include, for example, the cured products of this disclosure as interlayer insulating films, cover coat layers, surface protective films, passivation films, buffer coat films, etc.

[0124] An example of the manufacturing process for a semiconductor device, which is an electronic component of the present disclosure, will be described with reference to the drawings. Figure 1 is a manufacturing process diagram for a multilayer wiring structure semiconductor device, which is an electronic component according to one embodiment of the present disclosure. In Figure 1, a semiconductor substrate 1, such as a Si substrate having circuit elements, is covered with a protective film 2, such as a silicon oxide film, except for predetermined portions of the circuit elements, and a first conductor layer 3 is formed on the exposed circuit elements. Thereafter, an interlayer insulating film 4 is formed on the semiconductor substrate 1.

[0125] Next, a photosensitive resin layer 5, such as a chlorinated rubber-based or phenol novolac-based resin, is formed on the interlayer insulating film 4, and a window 6A is provided so that a predetermined portion of the interlayer insulating film 4 is exposed by known photographic etching techniques.

[0126] The interlayer insulating film 4 with window 6A exposed is selectively etched to create window 6B. Next, the photosensitive resin layer 5 is removed using an etching solution that corrodes the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed through window 6B.

[0127] Furthermore, a second conductor layer 7 is formed using a known photoetching technique, and an electrical connection is made with the first conductor layer 3. When forming a multilayer wiring structure of three or more layers, the above steps can be repeated to form each layer.

[0128] Next, the window 6C is opened by pattern exposure using the resin composition of this disclosure, and a surface protective film 8 is formed. The surface protective film 8 protects the second conductive layer 7 from external stress, alpha rays, etc., and the resulting semiconductor device has excellent reliability. In addition, in the above example, the interlayer insulating film 4 can also be formed using the resin composition of this disclosure.

[0129] The present disclosure will be described in more detail below based on examples and comparative examples. However, the present disclosure is not limited to the examples described below.

[0130] <Comparative Example 1> (Synthesis of Polyimide Precursor) 20 g of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride (BPDA) and 35 g of 4,4'-oxydiphthalic acid dianhydride (ODPA) were placed in a reaction vessel. Next, 50 g of 2-hydroxyethyl methacrylate (HEMA) and 400 ml of γ-butyrolactone (BLO) as a solvent were placed in the reaction vessel to obtain a reaction mixture. After the exothermic reaction was complete, the mixture was allowed to cool to room temperature and left for 16 hours.

[0131] Under ice cooling, 75 g of dicyclohexylcarbodiimide (DCC) was dissolved in 300 ml of BLO and added to the reaction mixture over 40 minutes with stirring. Subsequently, 20 g of 2,2'-dimethylbiphenyl-4,4'-diamine (DMAP) and 10 g of p-phenylenediamine (PPD) were suspended in 150 ml of BLO, and this suspension was added to the reaction mixture over 60 minutes with stirring. After stirring at room temperature for 2 hours, 50 ml of ethyl alcohol was added to the reaction mixture and stirred for 1 hour, and then 100 ml of BLO was added to obtain a reaction solution containing the polyimide precursor.

[0132] The reaction solution containing the polyimide precursor was added dropwise to water as a poor solvent to precipitate the polyimide precursor. The resulting precipitate was filtered off and vacuum-dried at 40°C for 48 hours to obtain a powdered polyimide precursor.

[0133] (Preparation of Resin Composition) The following components were mixed to prepare the resin composition: Polyimide precursor: 10 g Solvent: BLO: 20 g Polymerization inhibitor: 1,4,4-trimethyl-2,3-diazabicyclo[3.2.2]nona-2-ene-2,3-dioxide (Taobn): 0.5 g Crosslinking agent: TEGDMA (triethylene glycol dimethacrylate): 2 g Photopolymerization initiator: 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyloxime (Irgacure OXE1, BASF): 0.5 g

[0134] (Storage Test) The resin composition was placed in a sealed container immediately after preparation and stored at room temperature (25°C) for testing. Specifically, the number of days from the start of the test (day 0) until gelation was observed was investigated. As a result, gelation of the resin composition was observed 3 days after the start of the test.

[0135] <Examples 1-4> Resin compositions were prepared in the same manner as in Comparative Example 1, except that BLO with the acids shown in Table 1 added was used as the solvent for preparing the resin composition, and storage tests were conducted on the resin compositions. The results are shown in Table 1. The amounts of acid shown in Table 1 are per 100 parts by mass of polyimide precursor (parts by mass).

[0136]

[0137] As shown in Table 1, the resin compositions of the examples with added acid showed a longer period before gelation occurred and exhibited superior storage stability compared to the comparative example resin composition without added acid.

[0138] <Examples 5-7> Resin compositions were prepared in the same manner as in Comparative Example 1, except that the acids shown in Table 2 were added to the reaction solution containing the polyimide precursor, and storage tests were conducted on the resin compositions. The results are shown in Table 2. The amounts of acid shown in Table 2 are per 100 parts by mass of polyimide precursor (parts by mass).

[0139]

[0140] As shown in Table 2, the resin compositions of the examples in which acid was added to the reaction solution containing the polyimide precursor showed a longer period until gelation occurred and superior storage stability compared to the resin composition of Comparative Example 1 in which acid was not added to the reaction solution containing the polyimide precursor.

[0141] <Examples 8-10> Resin compositions were prepared in the same manner as in Comparative Example 1, except that water containing the acid shown in Table 3 was used as the poor solvent to dropwise add the reaction solution containing the polyimide precursor, and storage tests were conducted on the resin compositions. The results are shown in Table 3. The amounts of acid shown in Table 3 are per 100 parts by mass of polyimide precursor (parts by mass).

[0142]

[0143] As shown in Table 3, the resin compositions of the examples in which the reaction solution containing the polyimide precursor was added dropwise in a poor solvent containing an acid had a longer time until gelation occurred and exhibited superior storage stability compared to the resin composition of Comparative Example 1 in which the reaction solution containing the polyimide precursor was added dropwise in a poor solvent containing an acid.

Claims

A step of reacting a tetracarboxylic acid compound and a diamine compound in the presence of an organic dehydrating agent to obtain a polyimide precursor containing polymerizable unsaturated bonds, The process includes contacting the polyimide precursor with an acid, A method for producing polyimide precursors. 　 The method for producing a polyimide precursor according to claim 1, wherein the step of contacting the polyimide precursor with an acid is to prepare a resin composition containing the polyimide precursor and the acid. 　 The method for producing a polyimide precursor according to claim 1, wherein the step of contacting the polyimide precursor with an acid includes adding an acid to a reaction solution containing the polyimide precursor. 　 The step of contacting the polyimide precursor with an acid includes contacting a solution obtained by dissolving the polyimide precursor in a good solvent with a poor solvent. A method for producing a polyimide precursor according to claim 1, wherein at least one of the good solvent or the poor solvent contains an acid. 　 The method for producing a polyimide precursor according to claim 1, wherein the pKa of the acid is 1 or less. 　 The method for producing a polyimide precursor according to claim 1, wherein the acid does not contain fluorine. 　 A resin composition comprising a polyimide precursor, which is a reaction product of a tetracarboxylic acid compound and a diamine compound and contains polymerizable unsaturated bonds, and an acid. 　 The resin composition according to claim 7, wherein the pKa of the acid is 1 or less. 　 The resin composition according to claim 7, wherein the acid does not contain fluorine. 　 Irradiating the resin composition according to any one of claims 7 to 9 with activated light in a patterned manner, A method for producing a cured product, comprising heating the resin composition that has been irradiated with active light. 　 A method for producing a cured product according to claim 10, further comprising removing a portion of the resin composition that has been irradiated with active light. 　 A cured product of the resin composition according to any one of claims 7 to 9. 　 An electronic component comprising the cured product described in claim 12.

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