Photosensitive resin composition, cured film thereof, and semiconductor package including said cured film

Abstract

Provided is a photosensitive resin composition that produces a cured film having high adhesive strength with a metal even when imidized at a low temperature. The photosensitive resin composition contains: a polyamic acid resin having a structural unit (A) derived from a tetracarboxylic acid anhydride and a structural unit (B) derived from a diamine; and a non-ionic photobase generator.

Description

Photosensitive resin composition, cured film thereof, and semiconductor package including the cured film

[0001] The present invention relates to a photosensitive resin composition, a cured film of the photosensitive resin composition, and a semiconductor package including the cured film.

[0002] Conventionally, resin compositions containing polyimides, which have high insulating properties, heat resistance, mechanical strength, etc., have been used as coating materials for semiconductor elements, flexible wiring boards, and insulating interlayer materials in semiconductor packages. In recent years, photosensitive resin compositions, in which the resin itself is photosensitive, have been used as such resin compositions for reasons such as improving productivity and simplifying the manufacturing process. Meanwhile, in the manufacture of semiconductor packages, low-temperature curing of resin compositions is required from the viewpoints of protecting high-performance dies and materials with low heat resistance (e.g., encapsulants, temporary bonding materials, etc.) and improving yield, in addition to the viewpoints of manufacturing costs and environmental protection.

[0003] In view of the above, for example, Patent Document 1 discloses a photosensitive resin composition that can form a polyimide film by imidizing a polymer precursor having a repeating unit of polyamic acid or polyamic acid ester at a low temperature through a reaction with a nonionic photoreactive latent basic substance.

[0004] International Publication No. 2015 / 019802

[0005] Furthermore, photosensitive resin compositions are also required to have excellent adhesive strength between metals used in semiconductor materials such as wiring and polyimide resins. However, Patent Document 1 does not consider these properties. An object of the present invention is to provide a photosensitive resin composition that provides a cured film with high adhesive strength to metals even when imidized at low temperatures.

[0006] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have completed the present invention. That is, the present invention provides the following preferred embodiments: [1] A photosensitive resin composition comprising a polyamic acid resin having a tetracarboxylic anhydride-derived structural unit (A) and a diamine-derived structural unit (B), and a nonionic photobase generator. [2] The structural unit (B) is represented by the following formula (B1): [In formula (B1), X １ [3] The photosensitive resin composition according to [2], wherein X in formula (B1) is an aliphatic group having 14 or more carbon atoms. [4] The photosensitive resin composition according to [1], wherein X in formula (B1) is an aliphatic group having 14 or more carbon atoms. [5] The photosensitive resin composition according to [2], wherein X in formula (B1) is an aliphatic group having 14 or more carbon atoms. １ [5] The photosensitive resin composition according to [2] or [3], wherein the aliphatic diamine represented by formula (B1) is a saturated aliphatic group having 14 or more carbon atoms. [In formula (b1), m, n, p, and q each independently represent a number from 3 to 24, and the sum of m, n, p, and q is 12 to 60.] [6] The photosensitive resin composition according to [5], wherein in formula (b1), the sum of m and n is 6 to 40, and the sum of p and q is 6 to 40. [7] The structural unit (A) is a dimer diamine represented by formula (A1): [In the formula, R ａ１ each independently represent a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and each 1 is independently an integer of 0 to 3], and / or a structural unit (A1) derived from a tetracarboxylic acid anhydride represented by formula (A2): [In the formula, R ａ２ each independently represent a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and k represents an integer of 0 to 2. [8] The photosensitive resin composition according to any one of [1] to [6], wherein the nonionic photobase generator is a compound represented by the following formula (N): [9] The photosensitive resin composition according to any one of [1] to [7], wherein Pho is an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, and Am is an amino group having 1 to 20 carbon atoms. [In the formula, R １ ~R １０are each independently any one of hydrogen, methyl, ethyl, phenyl, methoxy, ethoxy, phenoxy, hydroxyl, nitro, cyano, halogen, trifluoromethyl, carboxymethyl ester, and carboxyethyl ester; １ , X ２ , X ３ are each independently any one of hydrogen, a methyl group, an ethyl group, and a cyano group.

[10] The photosensitive resin composition according to [8] or [9], wherein the amino group represented by Am contains tertiary nitrogen.

[11] The photosensitive resin composition according to any one of [8] to

[10] , wherein in formula (N), a nitrogen atom in the amino group represented by Am is bonded to a carbon atom in the carbonyl group.

[12] The photosensitive resin composition according to any one of [8] to

[11] , wherein Am is an amino group derived from any one of azoles, piperidines, guanidines, and amidines.

[13] A cured film of the photosensitive resin composition according to any one of [1] to

[12] .

[14] A semiconductor package comprising the cured film according to

[13] .

[0007] According to the present invention, it is possible to provide a photosensitive resin composition that can provide a cured film with high adhesive strength to metal even when imidized at low temperatures.

[0008] [Photosensitive Resin Composition] The photosensitive resin composition of the present invention comprises a polyamic acid resin having a tetracarboxylic anhydride-derived structural unit (A) and a diamine-derived structural unit (B), and a nonionic photobase generator. The inventors have unexpectedly discovered that by using a nonionic photobase generator to imidize the polyamic acid resin, a cured film with high adhesive strength to metals (particularly copper, silver, gold, and aluminum) can be obtained even when imidized at low temperatures. The reason for this is unclear, and although not intended to be limiting, the following mechanism of action is presumed. The nonionic photobase generator is an agent that generates a base upon excitation when irradiated with actinic rays, and its structure includes a photosensitive moiety and a base moiety that is released upon excitation. When the photosensitive resin composition of the present invention is irradiated with actinic rays, the base generated by the excitation promotes the imidization of the polyamic acid resin. On the other hand, it is believed that the photosensitive moieties remaining after the elimination of the base penetrate into gaps in the imidized product of the polyamic acid resin (polyimide-based resin) and contribute to the adhesive strength between the metal and the polyimide-based resin (hereinafter sometimes abbreviated as "PI-based resin"). The high adhesive strength between the metal and the PI-based resin can provide products containing the metal and the PI-based resin with excellent resistance to external forces such as chemical mechanical polishing and impact during the manufacturing process, as well as to the usage environment. Therefore, from the viewpoints of the yield during the manufacturing process of the product and the reliability of the product, it is a great advantage of the present invention that the photosensitive resin composition of the present invention produces a cured film with excellent adhesive strength to the metal even when imidized at low temperatures.

[0009] <Polyamic Acid Resin> The polyamic acid resin of the present invention has one or more tetracarboxylic anhydride-derived structural units (A) (hereinafter sometimes simply referred to as "structural units (A)") and one or more diamine-derived structural units (B) (hereinafter sometimes simply referred to as "structural units (B)"). From the viewpoint that a photosensitive resin composition containing the polyamic acid resin can provide higher adhesive strength to metal even when imidized at low temperatures, and from the viewpoint of having high film-formability and stability over time, the polyamic acid resin preferably has two or more types of structural units (A), and more preferably has two types of structural units (A). From the same viewpoint, the polyamic acid resin preferably has two or more types of structural units (B), and more preferably has two types of structural units (B).

[0010] The polyamic acid resin may be a block copolymer or a random copolymer. From the viewpoint that a photosensitive resin composition containing the polyamic acid resin can provide higher adhesive strength with metal even when imidized at low temperatures, the polyamic acid resin is preferably a block copolymer. When the polyamic acid resin is a block copolymer containing two or more structural units (A), for example, the two structural units (A1) and (A2) described below, i.e., when the polyamic acid resin is a block copolymer containing a block containing the structural unit (A1) and a block containing the structural unit (A2), the structural units (B) constituting both blocks may be the same or different. Similarly, when the polyamic acid resin is a block copolymer containing two or more structural units (B), for example, the two structural units (B1) and (B2) described below, i.e., when the polyamic acid resin is a block copolymer containing a block containing the structural unit (B1) and a block containing the structural unit (B2), the structural units (A) constituting both blocks may be the same or different. In the present invention, the term "structural unit derived from" means "a structural unit derived from", for example, "structural unit (A) derived from a tetracarboxylic acid anhydride" means "structural unit (A) derived from a tetracarboxylic acid anhydride", and the same applies to other structural units.

[0011] (Tetracarboxylic Acid Anhydride-Derived Structural Unit (A)) The tetracarboxylic acid anhydride-derived structural unit (A) is, for example, a structural unit represented by the formula (1): In the formula (1), Y represents a tetravalent organic group.

[0012] In formula (1), Y's each independently represent a tetravalent organic group, preferably a tetravalent organic group having 4 to 40 carbon atoms, and more preferably a tetravalent organic group having 4 to 40 carbon atoms and a cyclic structure. Examples of the cyclic structure include an alicyclic, aromatic ring, and heterocyclic structure. The organic group may have a hydrogen atom substituted with a halogen atom, a hydrocarbon group, an alkoxy group, or a halogenated hydrocarbon group, and in such cases, the number of carbon atoms in these groups is preferably 1 to 8. In the present invention, the polyamic acid resin may contain multiple types of Y's, and the multiple types of Y's may be the same or different. Examples of Y include groups or structures represented by formulas (31) to (40); groups in which a hydrogen atom in a group represented by formulas (31) to (40) is substituted with a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, fluoro group, chloro group, or trifluoromethyl group; and tetravalent chain hydrocarbon groups having 1 to 8 carbon atoms.

[0013] [In formulas (31) to (33), R １９ ~R ２６ and R ２３’ ~R ２６’ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R １９ ~R ２６ and R ２３’ ~R ２６’ The hydrogen atoms contained in V may be substituted with halogen atoms independently of each other, １ and V ２ are each independently a single bond (except when e+d=1), —O—, —CH ２ -, -CH ２ -CH ２ -, -CH(CH ３ ) -, -C(CH３ ) ２ -, -C(CF ３ ) ２ -, -SO ２ -, -S-, -CO-, -N(R ｊ ) - or formula (a): (In formula (a), R ２７ ~R ３０ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and each D independently represents a single bond, —C(CH ３ ) ２ - or - C(CF ３ ) ２ i represents an integer of 1 to 3, * represents a bond, ｊ represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom; e and d each independently represent an integer of 0 to 2 (provided that e+d is not 0); f represents an integer of 0 to 3; g and h each independently represent an integer of 0 to 4; in formula (39), Z represents a divalent organic group; R ａ３ each independently represents a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom; each s independently represents an integer of 0 to 3; and in formula (40), R ａ２ each independently represents a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom; each 1 independently represents an integer of 0 to 3; and * represents a bond.

[0014] From the viewpoint that a photosensitive resin composition containing the polyamic acid resin can provide higher adhesive strength to metal even when imidized at low temperatures, and further from the viewpoint that the polyamic acid resin can have higher film-forming properties and stability over time, the polyamic acid resin in the present invention preferably contains, as Y in formula (1), at least one structure selected from the group consisting of structures represented by formula (31), formula (32), formula (33), formula (39), and formula (40), more preferably contains at least one structure selected from the group consisting of structures containing a benzene skeleton, further preferably contains at least one structure selected from the group consisting of structures represented by formula (32), formula (39), and formula (40), and particularly preferably contains a structure represented by formula (32) and / or a structure represented by formula (40).

[0015] In formulas (31) to (33), R １９ ~R ２６ and R ２３’ ~R ２６’ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.

[0016] In formula (31), V １ and V ２ are each independently preferably a single bond (except when e+d=1), —O—, or —CH ２ -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ - or -CO-, and more preferably a single bond (except when e+d=1), -O-, -C(CH ３ ) ２ - or - C(CF ３ ) ２ Represents -.

[0017] In formula (31), e and d each independently preferably represent 0 or 1 (provided that e+d is not 0). Also, e+d preferably represents 1. In formula (31), when e is 0, the two benzene rings are V １When d is 0, the two benzene rings are V ２ indicates that there is no bond.

[0018] In the formulas (32) and (33), f preferably represents 0 or 1, and more preferably 0.

[0019] In formula (33), g and h each independently represent preferably an integer of 0 to 2, more preferably 0 or 1. Furthermore, g+h preferably represents an integer of 0 to 2. When f is 1 or greater, multiple g's and multiple h's may each independently be the same or different.

[0020] In formula (a), R ２７ ~R ３０ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom. i is preferably 1 or 2, and when i is 2 or more, a plurality of D and R ２７ ~R ３０ may be the same or different, independently of each other.

[0021] In formula (39), Z preferably represents a divalent organic group having 4 to 40 carbon atoms, more preferably a divalent organic group having 4 to 40 carbon atoms and a cyclic structure, still more preferably a divalent organic group having 4 to 40 carbon atoms and an aromatic ring, and particularly preferably a divalent organic group represented by formula (z1), formula (z2), or formula (z3): [In formulas (z1) to (z3), R ｚ１１ ~R ｚ１４ each independently represents a hydrogen atom or a monovalent hydrocarbon group which may have a halogen atom; R ｚ２ each independently represents a monovalent hydrocarbon group which may have a halogen atom; n represents an integer of 1 to 4; j represents each independently an integer of 0 to 3; * represents a bond], and particularly preferably represents a divalent organic group represented by formula (z1).

[0022] In formula (z1), R ｚ１１ ~R ｚ１４are each independently preferably a hydrogen atom or an alkyl group which may have a halogen atom, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, even more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms which may have a halogen atom, and particularly preferably a hydrogen atom. ｚ１１ ~R ｚ１４ In the benzene ring having R ｚ１１ ~R ｚ１４ At least one of R may be a monovalent hydrocarbon group which may have a halogen atom. ｚ１１ ~R ｚ１４ are particularly preferably all hydrogen atoms.

[0023] In formula (z1), n ​​is preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 2.

[0024] In formula (z2), R ｚ２ are each independently preferably an alkyl group which may have a halogen atom, more preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, and even more preferably an alkyl group having 1 to 3 carbon atoms which may have a halogen atom.

[0025] In formula (z2), j's are preferably each independently 0 or 1, more preferably 0, and even more preferably all j's are 0.

[0026] In formula (39), R ａ３ Preferably, each independently represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. ａ３ The hydrogen atoms contained in R may be substituted with halogen atoms independently of each other. ａ３ are each independently an alkyl group preferably having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.

[0027] In formula (39), each s preferably represents an integer of 0 to 2, more preferably 0 or 1, independently of one another.

[0028] In formula (40), R ａ２Preferably, each independently represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. ａ２ The hydrogen atoms contained in R may be substituted with halogen atoms independently of each other. ａ２ are each independently preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.

[0029] In formula (40), 1 preferably represents an integer of 0 to 2, more preferably 0 or 1, independently of one another.

[0030] Specific examples of the structures represented by formulas (31) to (33), (39) and (40) include structures represented by formulas (41) to (56). In these formulas, * represents a bond.

[0031]

[0032] (Structural Unit (A1) and Structural Unit (A2)) In one embodiment of the present invention, the structural unit (A) that constitutes the polyamic acid resin is represented by the formula (A1): [In formula (A1), R ａ１ each independently represent a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and each l independently represent an integer of 0 to 3], and / or a structural unit (A1) (hereinafter, sometimes abbreviated as simply "structural unit (A1)") derived from a tetracarboxylic acid anhydride represented by formula (A2): [In formula (A2), R ａ２ are each independently a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which optionally has a halogen atom, and k is an integer of 0 to 2.

[0033] When the polyamic acid resin contains the structural unit (A1) and / or the structural unit (A2) as the structural unit (A), the photosensitive resin composition containing the polyamic acid resin can exhibit higher adhesive strength with metals even when imidized at low temperatures, and can also have higher film-formability and stability over time. Higher adhesive strength with metals can improve the yield in the manufacturing process of products containing cured films of the photosensitive resin composition of the present invention, and can improve the reliability of the products. From the viewpoint of further enhancing the effects of the present invention, in one embodiment of the present invention, the polyamic acid resin more preferably contains at least the structural unit (A1) as the structural unit (A), and even more preferably contains both the structural unit (A1) and the structural unit (A2).

[0034] From the viewpoint of obtaining improved adhesive strength to metal even when the photosensitive resin composition is imidized at low temperature, and further from the viewpoint of higher film-forming property and stability over time of the photosensitive resin composition, in the formula (A1) and the formula (A2), R ａ１ and R ａ２ are preferably, each independently, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2-ethylpropyl group, and an n-hexyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group. R ａ１ and R ａ２ The hydrogen atoms contained in R may be substituted with halogen atoms, and examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. ａ1 and R ａ2are each independently preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms.

[0035] The bonding positions of the two carboxylic acid anhydrides bonded to the benzene rings constituting the biphenyl skeleton in formula (A1) are not particularly limited and may be, independently of one another, the 3,4-positions or the 2,3-positions based on the single bond bonding the two benzene rings. From the viewpoint of obtaining improved adhesive strength to metals even when the photosensitive resin composition is imidized at low temperatures, and further from the viewpoint of higher film-forming ability and stability over time of the photosensitive resin composition, the 3,4-positions are preferred. In formula (A1), 1 is each independently preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0036] The bonding positions of the two carboxylic acid anhydrides bonded to the benzene ring in formula (A2) are not particularly limited, but from the viewpoint of being able to obtain improved adhesive strength to metal even when the photosensitive resin composition is imidized at low temperature, and further from the viewpoint of higher film-forming ability and stability over time of the photosensitive resin composition, the bonding positions are preferably the 1,2-positions and the 4,5-positions, or the 1,2-positions and the 3,4-positions, and more preferably the 1,2-positions and the 4,5-positions. k is preferably 0 or 1, and more preferably 0.

[0037] In a preferred embodiment of the present invention, formula (A1) is represented by formula (A1-1): In another preferred embodiment of the present invention, the structural unit (A2) is a structural unit (A1-1) represented by the formula (A2-1): When the polyamic acid resin contains the structural unit (A1-1) and / or the structural unit (A2-1) as the structural unit (A), the adhesive strength to metal of a cured film of a photosensitive resin composition containing the polyamic acid resin can be further improved even when imidized at low temperatures, and the film-formability and stability over time of the photosensitive resin composition can be further improved. From the viewpoint of further enhancing the effects of the present invention, in one embodiment of the present invention, the polyamic acid resin more preferably contains at least the structural unit (A1-1) as the structural unit (A), and even more preferably contains both the structural unit (A1-1) and the structural unit (A2-1).

[0038] In one embodiment of the present invention, when the polyamic acid resin contains the structural unit (A1) and / or the structural unit (A2), the total content of the structural units (A) is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, particularly preferably 80 mol% or more, and particularly preferably 90 mol% or more, and may even be 100 mol%. Furthermore, when the polyamic acid resin contains the structural unit (A1), the content of the structural unit (A) is preferably 10 mol% or more, more preferably 15 mol% or more, and even more preferably 20 mol% or more, with the upper limit being 100 mol%. When the polyamic acid resin contains the structural unit (A2), the content of the structural unit (A) is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and particularly preferably 50 mol% or more, with the upper limit being 100 mol%, and preferably 90 mol% or less, more preferably 80 mol% or less, with the upper limit being 100 mol%. When the contents of the structural unit (A1) and the structural unit (A2) are each within the above ranges, the adhesive strength of the cured film of the photosensitive resin composition containing the polyamic acid resin to metal can be further improved even when imidized at low temperatures, and further the film-forming properties and stability over time of the photosensitive resin composition can be further improved. １It can be measured using H-NMR, or can be calculated from the charging ratio of raw materials. The same applies to the contents of other structural units below. Furthermore, in this specification, the "total amount" of a structural unit refers to the amount of that unit when the structural unit consists of one unit, and refers to the total amount of those units when the structural unit consists of two or more units.

[0039] In one embodiment of the present invention, when the polyamic acid resin contains the structural unit (A1) and the structural unit (A2), the content ratio (molar ratio, (A1):(A2)) is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 20:80 to 50:50. When the content ratio of the structural unit (A1) to the structural unit (A2) is within the above range, the above-mentioned effects of the present invention that are expected from having the structural unit (A1) and the structural unit (A2) are more easily achieved, and these effects can be further enhanced.

[0040] (Diamine-derived structural unit (B)) The diamine-derived structural unit (B) is not particularly limited as long as it is a structural unit derived from a diamine. The structural unit (B) may be, for example, a structural unit represented by the formula (B0): In the formula (B0), X represents a divalent organic group.

[0041] In formula (B0), X represents a divalent organic group, preferably a divalent organic group having 2 to 100 carbon atoms. Examples of the divalent organic group include a divalent aromatic group and a divalent aliphatic group. Examples of the divalent aliphatic group include a divalent acyclic aliphatic group or a divalent cyclic aliphatic group. Among these, a divalent cyclic aliphatic group and a divalent aromatic group are preferred, from the viewpoint that the adhesive strength of a cured film of the photosensitive resin composition to a metal can be further improved even after imidization at low temperatures. The divalent organic group may have a hydrogen atom substituted with a halogen atom, a hydrocarbon group, an alkoxy group, or a halogenated hydrocarbon group, and in such cases, the number of carbon atoms in these groups is preferably 1 to 8. In this specification, a divalent aromatic group is a divalent organic group having an aromatic group, and may include an aliphatic group or other substituent as part of its structure. Furthermore, the divalent aliphatic group is a divalent organic group having an aliphatic group, and may contain other substituents as part of its structure, but does not contain an aromatic group. In one embodiment of the present invention, the polyamic acid resin may contain multiple types of X, and the multiple types of X may be the same or different. When the polyamic acid resin contains multiple types of X, it is preferable that X contains at least one type of divalent cycloaliphatic group and at least one type of divalent aromatic group.

[0042] In one embodiment of the present invention, the structural unit (B) is represented by the following formula (B1): [In formula (B1), X １ is an aliphatic group having 14 or more carbon atoms]. In this embodiment, the adhesive strength of a cured film of a photosensitive resin composition containing a polyamic acid resin to a metal can be further improved even when imidized at low temperature, and the film formability and stability over time of the photosensitive resin composition can be improved. In this embodiment, the term "aliphatic diamine" refers to a diamine having an aliphatic group. Although an aliphatic diamine may contain other substituents as part of its structure, it is distinguished from the "aromatic diamine" described below in that it does not have an aromatic ring.

[0043] X in formula (B1) １The aliphatic group having 14 or more carbon atoms represented by the formula (I) may be linear, branched, or cyclic. It may also be a saturated aliphatic group or an unsaturated aliphatic group, and may contain a substituent as part of its structure, but does not include an aromatic group.

[0044] X in formula (B1) １ The number of carbon atoms in the aliphatic group represented by X is preferably 14 to 80, more preferably 16 to 70, and even more preferably 18 to 60. １ When the number of carbon atoms in the aliphatic group represented by the formula (I) is within the above range, the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal can be further improved even when imidized at low temperature, and further the film-forming property and the temporal stability of the photosensitive resin composition can be further improved.

[0045] Examples of the substituent include a halogen atom, an alkoxy group, an aryl group, and an aryloxy group.

[0046] X in formula (B1) １ The amino group preferably has the shortest carbon chain connecting the two amino groups, and if it has a cyclic structure, it has a carbon chain containing the cyclic structure (hereinafter also referred to as the "main chain"), and a carbon chain branching from the carbon chain (hereinafter also referred to as the "side chain"). In this case, the number of carbon atoms in the side chain is preferably 4 to 60, more preferably 8 to 40, and even more preferably 12 to 20. Examples of hydrocarbon groups constituting the main chain and side chain include saturated or unsaturated, linear or cyclic hydrocarbon groups, and hydrocarbon groups bonded by ether bonds or sulfide bonds, and may contain a siloxane moiety. Preferred are saturated or unsaturated, linear or cyclic hydrocarbon groups, and hydrocarbon groups bonded by ether bonds, more preferably saturated or unsaturated, linear or cyclic hydrocarbon groups, and particularly preferably saturated, linear or cyclic hydrocarbon groups.

[0047] In one embodiment of the present invention, the aliphatic diamine represented by formula (B1) is preferably a dimer diamine. When the structural unit (B1) is a structural unit derived from a dimer diamine, the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal can be further improved even when imidized at low temperatures, and the film-forming ability and stability over time of the photosensitive resin composition can be further improved.

[0048] Dimer diamine refers to a dimer acid in which all carboxyl groups have been substituted with primary amino groups or primary aminomethyl groups. Dimer acid mainly contains a dibasic acid having 36 carbon atoms obtained by dimerizing unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid, and depending on the degree of purification, may also contain a monomer acid having 18 carbon atoms, a trimer acid having 54 carbon atoms, and a polymerized fatty acid having 20 to 90 carbon atoms. Dimer acids typically contain double bonds, but the degree of unsaturation can be reduced by, for example, hydrogenation (reduction), from which a dimer diamine with a low degree of unsaturation or a saturated dimer diamine can be obtained.

[0049] In the present invention, the dimer diamine may be either an acyclic dimer diamine or a cyclic dimer diamine. Examples of the acyclic dimer diamine include those represented by the following formula (D1) and formula (D2): [In formula (D1) and formula (D2), m, n, p, and q each independently represent a number from 3 to 24, and the sum of m, n, p, and q is 14 to 36.] In formula (D1) and formula (D2), m+n is preferably 6 to 17, and p+q is preferably 8 to 19.

[0050] Specific examples of saturated or unsaturated acyclic dimer diamines include those having the following structure: In the formula, the bond represented by the solid line and the dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.

[0051] Examples of the cyclic dimer diamine include those represented by the following formulae (D3) to (D6): [In formulas (D3) to (D6), m, n, p, and q each independently represent a number from 3 to 24, the sum of m, n, p, and q is 14 to 36, and the bond represented by the solid line and the dashed line represents a carbon-carbon single bond or a carbon-carbon double bond.] In formulas (D3) to (D6), m+n is preferably 6 to 17, and p+q is preferably 8 to 19.

[0052] Specific examples of saturated or unsaturated monocyclic dimer diamines include those having the following structures: In the following structures, the bonds represented by solid and dashed lines represent carbon-carbon single bonds or carbon-carbon double bonds.

[0053] The cyclic dimer diamine may also have a structure in which two or more saturated or unsaturated hydrocarbon rings are condensed. Specific examples of saturated or unsaturated condensed polycyclic dimer diamines include those having the following structures: In the following structures, the bonds represented by solid and dashed lines represent carbon-carbon single bonds or carbon-carbon double bonds.

[0054] In one embodiment of the present invention, X in formula (B1) １ is preferably a saturated aliphatic group having 14 or more carbon atoms, and the aliphatic diamine represented by formula (B1) ... [In formula (b1), m, n, p, and q each independently represent a number from 3 to 24, and the sum of m, n, p, and q is 12 to 60.] When the structural unit (B) is a structural unit derived from a saturated aliphatic diamine having 14 or more carbon atoms, particularly a dimer diamine represented by formula (b1), the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal can be further improved even when imidized at low temperatures, and further the film-formability and stability over time of the photosensitive resin composition can be further improved.

[0055] In the formula (b1), the sum of m, n, p, and q is preferably 12 to 60, more preferably 14 to 50, and even more preferably 18 to 40. The sum of m and n is preferably 6 to 40, more preferably 8 to 30, and even more preferably 10 to 20. The sum of p and q is preferably 6 to 40, more preferably 8 to 30, and even more preferably 10 to 20. When m, n, p, and q are numbers that satisfy the above-mentioned ranges, the effects of the present invention that are expected from the polyamic acid resin having the diamine-derived structural unit (B1) are more easily achieved, and these effects can be further enhanced.

[0056] When the structural unit (B) in the polyamic acid resin includes the structural unit (B1), its content is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 35 mol% or less, relative to the total amount of the structural unit (B). It may be, for example, 25 mol% or less, and is also preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and particularly preferably 20 mol% or more. When the content of the structural unit (B1) is within the above range, the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to metal can be further improved even when imidized at low temperatures, and the film formability and stability over time of the photosensitive resin composition can be further improved. In particular, when the content of the structural unit (B1) derived from dimer diamine relative to the total amount of the structural unit (B) is within the above range, the expected effects of the present invention can be more easily achieved.

[0057] In one embodiment of the present invention, the structural unit (B) preferably includes a structural unit (B2) derived from an aromatic diamine (hereinafter, sometimes abbreviated as "structural unit (B2)"). In this embodiment, the adhesive strength of a cured film of a photosensitive resin composition containing a polyamic acid resin to a metal can be further improved even when imidized at low temperature, and the film-forming ability and stability over time of the photosensitive resin composition can also be further improved.

[0058] The structural unit (B2) is a structural unit derived from an aromatic diamine containing one or more, preferably 2 to 4, and more preferably 2, aromatic rings, and is, for example, a structural unit represented by the formula (B2): [In formula (B2), X２ represents a divalent aromatic group]. When the polyamic acid resin contains the structural unit (B2), the cured film of the photosensitive resin composition of the present invention can exhibit higher adhesive strength with metals even when imidized at low temperatures, and further, the photosensitive resin composition can achieve higher film-formability and stability over time. The higher adhesive strength with metals can improve the yield in the manufacturing process of products containing cured films of the photosensitive resin composition of the present invention, and can improve the reliability of the products. In this embodiment, the term "aromatic diamine" refers to a diamine having an aromatic ring, and may contain an aliphatic group or other substituent as part of its structure. The aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a fluorene ring, but are not limited to these. Among these, a benzene ring is preferred.

[0059] In formula (B2), X ２ is a divalent aromatic group, and a hydrogen atom in the aromatic group may be substituted with a halogen atom, a hydrocarbon group, an alkoxy group, or a halogenated hydrocarbon group, and in such cases, the number of carbon atoms in these groups is preferably 1 to 8.

[0060] In one embodiment of the present invention, X in formula (B2) ２ Examples of the group include groups (structures) represented by formulas (60) to (62), and groups in which a hydrogen atom in a group represented by formulas (60) to (62) is substituted with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a fluoro group, a chloro group, or a trifluoromethyl group. Among these, it is more preferable that the group contains a structure represented by formula (60). [In formula (60), R ａ and R ｂ each independently represents a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom; R ａ and R ｂ Each hydrogen atom contained in may be substituted with a halogen atom, and each W is independently a single bond, —O—, or —CH ２ -, -CH２ -CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ -, -COO-, -OOC-, -SO-, -SO ２ -, -S-, -CO-, -N(R ｃ )- or -CONH-, R ｃ represents a monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a hydrogen atom or a halogen atom, t' represents an integer of 0 to 4, u represents an integer of 0 to 4, n represents an integer of 0 to 4, and * represents a bond.

[0061] In formula (60), the bonds of each benzene ring may be bonded at any of the ortho-, meta-, or para-positions, or the α-, β-, or γ-positions, relative to -W- or the single bond connecting each benzene ring, and are preferably bonded at the meta- or para-positions, or the β- or γ-positions, more preferably the para- or γ-positions, from the viewpoint that the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal can be further improved even when imidized at low temperatures. When the amino group directly bonded to the benzene ring and the divalent linking group -W- are at the meta-positions, the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal tends to be further improved even when imidized at low temperatures.

[0062] In formula (60), R ａ and R ｂ are each independently preferably a halogen atom, or an alkyl group, alkoxy group or aryl group which may have a halogen atom, more preferably a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, and the aryl group having 6 to 12 carbon atoms include those exemplified above in relation to formula (A1) and formula (A2). R ａ and R ｂThe hydrogen atoms contained in R may be substituted, independently of one another, with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. ａ and R ｂ are each independently preferably an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms, and from the viewpoint of adhesion to metal foil and the like, are more preferably a fluorine-free alkyl group having 1 to 6 carbon atoms, even more preferably a fluorine-free alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.

[0063] In formula (60), t' and u are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

[0064] In formula (60), each W is preferably a single bond, —O—, or —CH ２ -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ -, -SO ２ -, -S-, -COO-, -OOC- or -CO-, and more preferably a single bond, -O- or -CH ２ -, -C(CH ３ ) ２ -, -C(CF ３ ) ２ -, -COO-, -OOC- or -CO-, and more preferably a single bond, -O- or -CH ２ - or -C(CH ３ ) ２ -, and particularly preferably -O- or -C(CH ３ ) ２ - is.

[0065] In formula (60), n is preferably an integer of 0 to 3, more preferably 1 to 3. When n is 2 or more, a plurality of W, R ａ and t' may be the same or different, and the positions of the bonds of each benzene ring relative to -W- may be the same or different.

[0066] Specific examples of the structure represented by formula (60) include the following structures: In these formulas, * represents a bond.

[0067]

[0068] In one embodiment of the present invention, the structural unit (B2) is represented by formula (b2): [In formula (b2), R ｂ２ are each independently a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and p is an integer of 0 to 4. When the structural unit (B) includes the structural unit (b2), the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to metal can be further improved even when imidized at low temperatures, and further the film formability and stability over time of the photosensitive resin composition can be further improved.

[0069] In formula (b2), R ｂ２ preferably each independently represents a halogen atom, or an alkyl group, alkoxy group, or aryl group which may have a halogen atom, and more preferably represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, and the aryl group having 6 to 12 carbon atoms include those exemplified above. R ｂ２ The hydrogen atoms contained in R may be substituted with halogen atoms, independently of each other, and examples of the halogen atoms include the same as those mentioned above. ｂ２ are each independently preferably an alkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group having 1 to 6 carbon atoms, and from the viewpoint of adhesion to metal foil and the like, are more preferably fluorine-free alkyl groups having 1 to 6 carbon atoms, are even more preferably fluorine-free alkyl groups having 1 to 3 carbon atoms, and are particularly preferably methyl groups.

[0070] In formula (b2), p's are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

[0071] In formula (b2), —NH bonded to each benzene ring ２ The group may be bonded at any of the ortho-, meta-, or para-positions, or the α-, β-, or γ-positions, based on the single bond connecting each benzene ring. From the viewpoint that the adhesive strength of a cured film of the photosensitive resin composition to a metal can be further improved even after imidization at low temperatures, the group is preferably bonded at the meta- or para-position, or the β- or γ-position, more preferably at the para- or γ-position.

[0072] In a preferred embodiment of the present invention, formula (b2) is represented by formula (b2'): When the polyamic acid resin has the structural unit (b2), particularly a structural unit derived from a diamine represented by formula (b2′), as the structural unit (B2), the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to metal can be further improved even when imidized at low temperatures, and the film-forming properties and stability over time of the photosensitive resin composition can also be further improved.

[0073] When the structural unit (B) in the polyamic acid resin includes the structural unit (B2), the content thereof is preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 85 mol% or less, and particularly preferably 80 mol% or less, relative to the total amount of the structural unit (B). It is also preferably 60 mol% or more, more preferably 65 mol% or more, and even more preferably 70 mol% or more, for example, 75 mol% or more. When the content of the structural unit (B2) is within the above range, the adhesive strength of the cured film of the photosensitive resin composition containing the polyamic acid resin to metal can be further improved even when imidized at low temperatures. In particular, when the content of the structural unit (b2) relative to the total amount of the structural unit (B) is within the above range, the expected effects of the present invention are more easily achieved.

[0074] In one embodiment of the present invention, the structural unit (B) in the polyamic acid resin preferably includes a structural unit (B1) and a structural unit (B2). In this embodiment, even when imidized at low temperatures, a cured film of the photosensitive resin composition of the present invention can exhibit higher adhesive strength with metals, and further, the photosensitive resin composition can achieve higher film-forming properties and stability over time. The higher adhesive strength with metals can improve the yield in the manufacturing process of products containing cured films of the photosensitive resin composition of the present invention, and can improve the reliability of the products.

[0075] When the structural unit (B) in the polyamic acid resin includes the structural unit (B1) and the structural unit (B2), the combined content thereof is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, particularly preferably 85 mol% or more, particularly more preferably 90 mol% or more, and particularly preferably 95 mol% or more, and may be 100 mol% based on the total amount of the structural unit (B). When the combined content of the structural unit (B1) and the structural unit (B2) is at least the above-mentioned lower limit, the effects of the present invention that are expected from the polyamic acid resin having the structural unit (B1) and the structural unit (B2) are more easily achieved, and these effects can be further enhanced.

[0076] Furthermore, when the structural unit (B) in the polyamic acid resin includes the structural unit (B1) and the structural unit (B2), the content ratio of the structural unit (B1) to the structural unit (B2) (molar ratio, (B1):(B2)) is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 20:80 to 50:50. When the content ratio of the structural unit (B1) to the structural unit (B2) is within the above range, the above-mentioned effects of the present invention that are expected from the polyamic acid resin having the structural unit (B1) and the structural unit (B2) are more easily achieved, and these effects can be further enhanced.

[0077] In one embodiment of the present invention, the polyamic acid resin preferably contains an amide structural unit (I) containing the structural unit (A) and the structural unit (B1), and an amide structural unit (II) containing the structural unit (A) and the structural unit (B2). By containing the amide structural unit (I) and the amide structural unit (II) in the polyamic acid resin, even when imidized at low temperatures, the cured film of the photosensitive resin composition of the present invention can have higher adhesive strength with metals, and further, the photosensitive resin composition can achieve higher film-forming properties and stability over time. The higher adhesive strength with metals can improve the yield in the manufacturing process of products containing cured films of the photosensitive resin composition of the present invention, and can improve the reliability of the products.

[0078] As described above, the polyamic acid resin may be a block copolymer or a random copolymer. When the polyamic acid resin is a block copolymer, the polyamic acid resin contains two or more types of amide structural units as blocks. In this case, the polyamic acid resin preferably contains amide structural units (I) and amide structural units (II) as blocks, i.e., contains an amide block (I) consisting of a plurality of amide structural units (I) and an amide block (II) consisting of a plurality of amide structural units (II). When the polyamic acid resin is a random copolymer, the polyamic acid resin contains two or more types of amide structural units randomly. In this case, the polyamic acid resin preferably contains the amide structural units (I) and the amide structural units (II) randomly.

[0079] The amide structural unit (I) preferably contains the structural unit (A1) in addition to the structural unit (B1), more preferably contains the structural unit (A1) and the structural unit (B1) derived from dimer diamine, and even more preferably contains the structural unit (A1) and the structural unit (b1). The amide structural unit (II) preferably contains the structural unit (A1) or (A2) in addition to the structural unit (B2), more preferably contains the structural unit (A2) in addition to the structural unit (B2), and even more preferably contains the structural unit (A2) and the structural unit (b2).

[0080] In one embodiment of the present invention, it is preferred that the amide structural unit (I) comprises the structural unit (A1) and the structural unit (B1), and that the amide structural unit (II) comprises the structural unit (A1) or (A2) and the structural unit (B2); it is more preferred that the amide structural unit (I) comprises the structural unit (A1) and the structural unit (B1) derived from dimer diamine, and that the amide structural unit (II) comprises the structural unit (A2) and the structural unit (B2); it is even more preferred that the amide structural unit (I) comprises the structural unit (A1) and the structural unit (b1), and that the amide structural unit (II) comprises the structural unit (A2) and the structural unit (b2).

[0081] When the polyamic acid resin is a block copolymer containing an amide block (I) and an amide block (II), the content ratio of the amide block (I) to the amide block (II) (molar ratio, amide block (I):amide block (II)) is preferably 5:95 to 40:60, more preferably 10:90 to 35:65, and even more preferably 15:85 to 30:70.

[0082] When the polyamic acid resin is a block copolymer, the polymerization form of the block copolymer is not particularly limited as long as two or more types of amide blocks are repeatedly arranged in a chained state to some extent, or two or more types of amide blocks are arranged alternately, and may be any of so-called A-B type double block, A-B-A type triblock, alternating multiblock, graft, brush type block, star type block, random block, etc. When the polyamic acid resin is a block copolymer, the polymerization form of the block copolymer is preferably alternating multiblock or random block, from the viewpoint that the adhesive strength of a cured film of a photosensitive resin composition containing the polyamic acid resin to a metal can be further improved even when imidized at low temperature.

[0083] The imide block content can be measured by, for example, proton NMR, although the method is not limited thereto. Specifically, the proton integral ratio derived from the monomer in the imide block segment is compared with the proton integral ratio derived from the monomer at the bonding point between the imide block (I) and the imide block (II), thereby calculating the number of bonding points for each imide block with respect to the segment repeating unit, and thereby calculating the imide block content.

[0084] The polyamic acid resin may contain structural units other than the tetracarboxylic acid anhydride-derived structural unit (A) and the diamine-derived structural unit (B), as long as the effects of the present invention are not adversely affected. Examples of such structural units include structural units derived from other tetracarboxylic acids, dicarboxylic acids and their anhydrides or derivatives, and tricarboxylic acids and their anhydrides or derivatives. Examples of other tetracarboxylic acids include water adducts of the above-mentioned tetracarboxylic acid anhydrides. Examples of dicarboxylic acids and their anhydrides or derivatives include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their anhydrides or related acid chloride compounds. Examples of tricarboxylic acids and their anhydrides or derivatives include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and their anhydrides or related acid chloride compounds. When the polyamic acid resin contains structural units other than the structural unit (A) and the structural unit (B), the total content of such structural units is preferably 20 mol % or less, more preferably 10 mol % or less, based on the total structural units constituting the polyamic acid resin. In one embodiment of the present invention, the polyamic acid resin is substantially free of any structural units other than the structural unit (A) and the structural unit (B).

[0085] The various physical properties (such as molecular weight) of the polyamic acid resin in the present invention may be appropriately determined based on, for example, the following preferred ranges depending on the role and application required of the polyamic acid resin.

[0086] In one embodiment of the present invention, the polyamic acid resin has a polystyrene-equivalent weight average molecular weight (Mw) of preferably 5,000 to 200,000, more preferably 10,000 to 100,000, and even more preferably 15,000 to 80,000, from the viewpoints of ease of production or film-forming property of the varnish and solvent resistance of the cured product. Mw can be determined by gel permeation chromatography (hereinafter sometimes referred to as GPC) measurement and calculated in terms of standard polystyrene.

[0087] <Method for Producing Polyamic Acid Resin> The method for producing the polyamic acid resin is not particularly limited, and the polyamic acid resin can be produced by any known method. An exemplary production method for a block copolymer polyamic acid resin will be described below using a method for producing a polyamic acid resin formed by block copolymerization of amide structural units (I) and amide structural units (II). However, the method for producing the polyamic acid resin of the present invention is not limited to this production method, and those skilled in the art will understand how to produce polyamic acid resins of the present invention other than the above polyamic acid resin. The same applies to the production method for a random copolymer described below. A polyamic acid resin formed by block copolymerization of amide structural units (I) and amide structural units (II) can be produced, for example, by a method including: (1) a step (1) of reacting a tetracarboxylic acid anhydride constituting the amide structural units (I) with an aliphatic diamine compound to obtain the amide structural units (I); and (2) a step (2) of reacting the obtained amide structural units (I) with an aromatic diamine compound constituting the amide structural units (II) with a tetracarboxylic acid anhydride.

[0088] Examples of tetracarboxylic acid anhydrides used in the synthesis of polyamic acid resins include aromatic tetracarboxylic acid anhydrides such as aromatic tetracarboxylic acid dianhydrides; and aliphatic tetracarboxylic acid anhydrides such as aliphatic tetracarboxylic acid dianhydrides. The tetracarboxylic acid anhydrides in the amide structural unit (I) and the amide structural unit (II) may be the same or different. The tetracarboxylic acid anhydride may be a dianhydride or a tetracarboxylic acid anhydride analog such as an acid chloride compound.

[0089] Examples of the tetracarboxylic acid anhydride include the tetracarboxylic acid anhydride represented by the formula (A1) and the tetracarboxylic acid anhydride represented by the formula (A2), and can be appropriately selected from tetracarboxylic acid anhydrides known in the art. Specific examples include pyromellitic dianhydride (hereinafter sometimes referred to as PMDA), 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride (hereinafter sometimes referred to as BPADA), 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (hereinafter sometimes referred to as BPDA), 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride (hereinafter sometimes referred to as 6FDA), 4,4'- Oxydiphthalic dianhydride (hereinafter sometimes referred to as ODPA), 2,2',3,3'-, 2,3,3',4'- or 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, p-phenylenebis(trimellitic acid monoester dianhydride) (hereinafter sometimes referred to as TAHQ), trimellitic anhydride and 2,2',3,3',5,5'-hexamethyl- Esterification product with 4,4'-biphenol (hereinafter sometimes referred to as TMPBP), 4,4'-bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-ylcarbonyloxy)biphenyl (hereinafter sometimes referred to as BP-TME), 2,3',3,4'-diphenyl ether tetracarboxylic acid dianhydride, bis(2,3-dicarboxyphenyl) ether dianhydride, 3,3",4,4"-p-terphenyl tetracarboxylic acid dianhydride, 2,3,3",4"-p-terphenyl Tetracarboxylic acid dianhydrides, 2,2",3,3"-p-terphenyltetracarboxylic acid dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-propane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,2,7,8-, 1,2,6,7-phenanthrene-tetracarboxylic dianhydride, 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)tetrafluoropropane dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (hereinafter sometimes referred to as HPMDA), 2,3,5,6-cyclohexanetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, cyclopentane-1,2,3, 4-tetracarboxylic dianhydride, 4,4'-bis(2,3-dicarboxyphenoxy)diphenylmethane dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter sometimes referred to as CBDA), norbornane-2-spiro-α'-spiro-2"-norbornane-5,5',6,6'-tetracarboxylic anhydride, p-phenylenebis(trimellitate anhydride), 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5 ,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic acid dianhydride, 2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 2,3,6,7-tetrachloronaphthalene-2,3,6,7-tetracarboxylic acid dianhydride, 1,4,5,8-tetrachloronaphthalene-1,4,5,8-tetracarboxylic acid dianhydride, 1,4,5,8-tetrachloronaphthalene Phthalene-2,3,6,7-tetracarboxylic dianhydride, 2,3,8,9-perylene-tetracarboxylic dianhydride, 3,4,9,10-perylene-tetracarboxylic dianhydride, 4,5,10,11-perylene-tetracarboxylic dianhydride, 5,6,11,12-perylene-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, etc. These tetracarboxylic acid anhydrides can be used alone or in combination of two or more. Among them, it is preferable to use BPDA and PMDA in combination, from the viewpoint that a photosensitive resin composition containing a polyamic acid resin can exhibit improved adhesive strength to metal even when imidized at low temperature.

[0090] The diamine compound used in synthesizing the amide structural unit (I) of the polyamic acid resin is an aliphatic diamine having 14 or more carbon atoms and represented by formula (B1), preferably dimer diamine. Such an aliphatic diamine, particularly a dimer diamine, can be appropriately selected from aliphatic diamine compounds known in the art, and examples thereof include the same diamine compounds as those exemplified above as aliphatic diamines and dimer diamines that can be used in the structural unit (B1) that constitutes the polyamic acid resin of the present invention. Among these, it is preferable to use a dimer diamine represented by formula (b1), from the viewpoint of being able to exhibit improved adhesive strength to metals even when a photosensitive resin composition containing a polyamic acid resin is imidized at low temperatures.

[0091] The diamine compound used in the synthesis of the amide structural unit (II) of the polyamic acid resin is an aromatic diamine compound, and can be appropriately selected from diamine compounds known in the art. Examples of the aromatic diamine compound include 4,4'-diamino-2,2'-dimethylbiphenyl (hereinafter sometimes referred to as m-Tb), 4,4'-diamino-3,3'-dimethylbiphenyl (hereinafter sometimes referred to as o-Tb), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (hereinafter sometimes referred to as TFMB), 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (hereinafter sometimes referred to as TMB), 4,4'-diaminodiphenyl ether, and the like. ter, 1,3-bis(3-aminophenoxy)benzene (hereinafter sometimes referred to as 1,3-APB), 1,4-bis(4-aminophenoxy)benzene (hereinafter sometimes referred to as TPE-Q), 1,3-bis(4-aminophenoxy)benzene (hereinafter sometimes referred to as TPE-R), 2,2-bis[4-(4-aminophenoxy)phenyl]propane (hereinafter sometimes referred to as BAPP), 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'- Diaminobiphenyl, 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)biphenyl, bis[1-(4-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 4,4'-methylenedianiline, 3,3'-methylenedianiline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3-diaminodiphenylether, 3,4'-diaminodiphenylether, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4"-diamino-p-terphenyl, 3,3"-diamino-p-terphenyl, m-phenylenediamine , p-phenylenediamine (hereinafter sometimes referred to as p-PDA), resorcinol-bis(3-aminophenyl)ether, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis(p-β-amino-tert-butylphenyl)ether, bis(p-β-methyl-δ-aminopentyl)benzene, p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5- Diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-tert-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, piperazine, 4,4"-diamino-p-terphenyl, bis(4-aminophenyl)terephthalate, 1,4-bis(4-aminophenoxy)-2,5-di-tert-butylbenzene, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 1,4-bis[2-(4 -aminophenyl)-2-propyl]benzene, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-(hexafluoropropylidene)dianiline, 2'-methoxy-4,4'-diaminobenzanilide, 4,4'-diaminobenzanilide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 9,Examples of aromatic diamine compounds include 9-bis[4-(3-aminophenoxy)phenyl]fluorene, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,5-diamino-1,3,4-oxadiazole, bis[4,4'-(4-aminophenoxy)]benzanilide, bis[4,4'-(3-aminophenoxy)]benzanilide, 2,6-diaminopyridine, and 2,5-diaminopyridine. These aromatic diamine compounds can be used alone or in combination. Among these, from the viewpoint of being able to exhibit improved adhesive strength to metals even when a photosensitive resin composition containing a polyamic acid resin is imidized at low temperatures, biphenyl skeleton-containing diamines represented by formula (b2) are preferred, with m-Tb, o-Tb, TMB, TFMB, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 3,3'-diaminobiphenyl, and 4,4'-dimethoxybenzidine being more preferred, and m-Tb being even more preferred.

[0092] In addition, the polyamic acid resin may be obtained by further reacting any acid component, such as other tetracarboxylic acids, dicarboxylic acids, tricarboxylic acids, and their anhydrides and derivatives, in addition to the tetracarboxylic acid anhydride used in the synthesis of the polyamic acid resin, as long as the effect of the present invention is not affected. Examples of other tetracarboxylic acids include water adducts of the above tetracarboxylic acid anhydrides. Examples of dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their analogous acid chloride compounds and acid anhydrides. Examples of tricarboxylic acid compounds include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and their analogous acid chloride compounds and acid anhydrides.

[0093] In both steps (1) and (2), the reaction between the diamine compound and the tetracarboxylic acid anhydride is preferably carried out in a solvent. In particular, it is preferable to first dissolve the diamine compound in a solvent, and then mix the resulting solution with the tetracarboxylic acid anhydride to carry out the reaction. The solvent is not particularly limited as long as it can dissolve the diamine compound used and does not affect the reaction. Examples of the solvent include alcohol-based solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; phenol-based solvents such as phenol and cresol; ester-based solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, and ethyl lactate; lactone-based solvents such as γ-butyrolactone (hereinafter sometimes referred to as GBL) and γ-valerolactone; acetone, methyl ethyl ketone, cyclopentanone, and cyclohexanone. Examples of suitable solvents include ketone-based solvents such as pentane, hexane, and heptane; aliphatic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile-based solvents such as acetonitrile; ether-based solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide-based solvents such as N,N-dimethylacetamide (hereinafter sometimes referred to as DMAc) and N,N-dimethylformamide (hereinafter sometimes referred to as DMF); sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide, and sulfolane; carbonate-based solvents such as ethylene carbonate and propylene carbonate; pyrrolidone-based solvents such as N-methylpyrrolidone (hereinafter sometimes referred to as NMP); and combinations thereof. Among these, from the viewpoint of solubility, phenol-based solvents, lactone-based solvents, amide-based solvents, and pyrrolidone-based solvents are preferred, and amide-based solvents are more preferred.

[0094] The amounts of the diamine compound and the tetracarboxylic acid anhydride used can be appropriately determined depending on the ratio of the respective constituent units of the desired polyamic acid resin. In one embodiment of the present invention, in step (1), when the total number of moles of the diamine compound used per mole of the total amount of the tetracarboxylic acid anhydride is defined as the amine ratio, the amine ratio is preferably 0.750 moles or more and preferably 1.60 moles or less.

[0095] The reaction conditions for the aliphatic diamine compound and the tetracarboxylic acid anhydride can be appropriately selected depending on the type and amount of the diamine compound and tetracarboxylic acid anhydride used. The reaction temperature in step (1) is, for example, preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, even more preferably 80°C or lower. When the reaction temperature is within the above upper and lower limits, the effects of the present invention are easily achieved, and the reaction rate tends to be increased and the polymerization time can be shortened. The reaction time is not particularly limited and may be, for example, about 0.5 to 36 hours, preferably 1 to 24 hours.

[0096] In step (2), it is preferable to mix and dissolve the aromatic diamine compound that constitutes the amide structural unit (II) with the solution containing the amide structural unit (I) obtained in step (1), and then mix the resulting solution with the tetracarboxylic acid anhydride that constitutes the amide structural unit (II). When mixing the aromatic diamine compound with the solvent containing the amide structural unit (I), it is preferable to also mix a solvent suitable for dissolving the aromatic diamine compound. Examples of such solvents include the same solvents as those exemplified above. The solvent used in step (1) and the solvent used in step (2) may be the same or different, but it is preferable that they are the same from the viewpoint of handleability, etc.

[0097] In one embodiment of the present invention, in step (2), from the viewpoint of molecular weight control, the amine ratio, defined as the total number of moles of diamine compounds used per mole of the total amount of tetracarboxylic acid anhydrides, is preferably 0.75 moles or more and 1.60 moles or less.

[0098] The reaction conditions for the aromatic diamine compound and tetracarboxylic acid anhydride can be appropriately selected depending on the type and amount of the diamine compound and tetracarboxylic acid anhydride used. The reaction temperature in step (2) is, for example, preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, and preferably 100°C or lower, more preferably 90°C or lower, even more preferably 80°C or lower. When the reaction temperature is within the above upper and lower limits, the effects of the present invention are easily achieved, and the reaction rate tends to be increased and the polymerization time shortened. The reaction time is not particularly limited and may be, for example, about 0.5 to 36 hours, preferably 1 to 24 hours.

[0099] In the production of the polyamic acid resin of the present invention, the amounts of diamine compounds, tetracarboxylic anhydrides, etc. used can be appropriately determined depending on the ratio of each structural unit of the desired polyamic acid resin. In one embodiment of the present invention, the amine ratio calculated from the total amount of all diamine compounds relative to the total amount of all tetracarboxylic anhydrides used in the preparation of the polyamic acid resin is preferably 0.75 mol to 1.60 mol, more preferably 0.85 mol to 1.50 mol, and even more preferably 0.95 mol to 1.45 mol. If the amine ratio is close to 1.0 mol, the molecular weight tends to increase rapidly during synthesis. If the amine ratio is significantly different from 1.0 mol, the molecular weight of the resulting polyamic acid resin tends to decrease. If the molecular weight increases rapidly, it grows unevenly within the synthesis mass, making the physical properties of the polyimide-based resin obtained from the polyamic acid resin less stable. On the other hand, if the molecular weight is too low, the mechanical properties of the cured film of a photosensitive resin composition containing the polyamic acid resin tend to decrease.

[0100] The reaction of the diamine compound with the tetracarboxylic acid anhydride in step (1) and step (2) may be carried out, as necessary, in an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere or under reduced pressure. It is preferable to carry out the reaction in an inert atmosphere, such as a nitrogen atmosphere or an argon atmosphere, in a strictly controlled dehydrated solvent while stirring.

[0101] The obtained polyamic acid resin may be isolated once by a conventional method, but the reaction liquid containing the polyamic acid resin obtained by synthesis of the polyamic acid resin may be appropriately diluted with a solvent as needed and used as a polyamic acid resin solution without isolation.

[0102] An exemplary production method for a polyamic acid resin that is a random copolymer will be described below using a method for producing a polyamic acid resin formed by random copolymerization of amide structural units (I) and amide structural units (II). A polyamic acid resin formed by random copolymerization of amide structural units (I) and amide structural units (II) can be produced, for example, by a method comprising: (1') a step (1') of mixing an aliphatic diamine compound that constitutes the amide structural units (I) with an aromatic diamine compound that constitutes the amide structural units (II) to obtain a diamine compound mixture; and (2') a step (2') of reacting the obtained diamine compound mixture with a tetracarboxylic acid anhydride that constitutes the amide structural units (I) and a tetracarboxylic acid anhydride that constitutes the amide structural units (II).

[0103] The tetracarboxylic acid anhydride and diamine compound used in synthesizing the polyamic acid resin, as well as the optional acid component, can be those described in the exemplary production method for when the polyamic acid resin is a block copolymer. In both steps (1') and (2'), the reaction between the diamine compound and the tetracarboxylic acid anhydride is preferably carried out in a solvent. It is particularly preferable to first dissolve the diamine compound in a solvent and then mix the resulting solution with the tetracarboxylic acid anhydride to carry out the reaction. That is, in step (1'), an aliphatic diamine compound and an aromatic diamine compound are preferably dissolved in a solvent, and in step (2'), the diamine compound mixture is preferably reacted with the tetracarboxylic acid anhydride constituting the amide structural unit (I) and the tetracarboxylic acid anhydride constituting the amide structural unit (II) in the resulting solution. In step (2'), the reaction is preferably carried out by dissolving the tetracarboxylic acid anhydride constituting the amide structural unit (I) in a solution containing the diamine compound mixture and then mixing the resulting solution with the tetracarboxylic acid anhydride constituting the amide structural unit (II). As the solvent, those described in the description of the exemplary production method when the polyamic acid resin is a block copolymer can be used.

[0104] The amounts of the diamine compound and tetracarboxylic acid anhydride used can be appropriately determined depending on the ratio of the respective constituent units of the desired polyamic acid resin. In one embodiment of the present invention, in step (2'), it is preferable that the diamine compound mixture is present in an excess amount relative to the tetracarboxylic acid anhydride. For example, the amine ratio, defined as the total number of moles of the diamine compound mixture used per mole of the total amount of tetracarboxylic acid anhydride, is preferably 1.001 moles or more and preferably 1.10 moles or less.

[0105] In step (1'), from the viewpoint of the solubility of the diamine compound mixture in the solvent, it is preferable to heat the solution containing the diamine compound mixture. The temperature in step (1') is preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, and is preferably 100°C or lower, more preferably 90°C or lower, even more preferably 80°C or lower. The heating time is not particularly limited and may be the time required for the diamine compound mixture to dissolve in the solvent, which may be, for example, 0.5 to 36 hours.

[0106] The reaction of the diamine compound mixture with the tetracarboxylic acid anhydride in step (2') may be carried out, if necessary, in an inert atmosphere such as a nitrogen atmosphere or an argon atmosphere or under reduced pressure. It is preferable to carry out the reaction in an inert atmosphere, such as a nitrogen atmosphere or an argon atmosphere, in a strictly controlled dehydrated solvent while stirring.

[0107] The obtained polyamic acid resin may be isolated once by a conventional method, but the reaction liquid containing the polyamic acid resin obtained by synthesis of the polyamic acid resin may be appropriately diluted with a solvent as needed and used as a polyamic acid resin solution without isolation.

[0108] <Nonionic Photobase Generator> A nonionic photobase generator is an agent that is excited by exposure to generate a base, and its structure includes a photosensitive moiety and a base moiety that is released by the excitation. The base generated by exposure can sufficiently promote the imidization of a polyamic acid resin even at low temperatures, thereby producing a PI resin with a high imidization rate. Since the resin composition of the present invention is photosensitive, for example, a patterned PI resin layer (a cured PI resin film) can be formed by coating the resin composition and exposing the resulting coating film while partially covering it with a mask. Specifically, while the resin composition is soluble in a developer, a PI resin with a high imidization rate has low solubility in the developer. By utilizing this, a PI resin layer is generated only in a portion (exposed portion) of the coating film by the exposure, and then the resin composition in the unexposed portion is removed with a developer, thereby forming a patterned PI resin layer. Even when a resin composition is not photosensitive, low-temperature imidization can be achieved by using an appropriate imidizing agent. However, forming a patterned PI-based resin layer using such a resin composition requires a complex manufacturing process and reduces productivity. In the present invention, such problems can be avoided by using a photosensitive resin composition and a nonionic photobase generator. Furthermore, the photosensitive moiety of the nonionic photobase generator remaining after the base is released from the photosensitive resin composition by exposure to light is believed to contribute to the adhesive strength between the metal and the PI-based resin by remaining in the gaps in the PI-based resin. Furthermore, since the photobase generator is nonionic, the photosensitive resin composition has excellent solubility in organic solvents typically contained in photosensitive resin compositions, and the photosensitive resin composition is less likely to become highly viscous, resulting in excellent film-forming properties. Furthermore, since the base is covalently bonded to the photobase generator, the base's performance is not expressed in the photosensitive resin composition, and therefore the photosensitive resin composition of the present invention has excellent stability over time.

[0109] The wavelength of a high-pressure mercury lamp generally used for exposure is 436 nm, 405 nm, or 365 nm, and the wavelength of a similarly generally used KrF excimer laser is 248 nm. Therefore, the nonionic photobase generator preferably absorbs any wavelength in the range of 240 to 450 nm, and more preferably absorbs at least one wavelength of 436 nm, 405 nm, 365 nm, and 248 nm.

[0110] In the present invention, the nonionic photobase generators may be used singly or in combination of two or more.

[0111] The nonionic photobase generator is preferably represented by the following formula (N): [In formula (N), Pho represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, and Am represents an amino group having 1 to 20 carbon atoms].

[0112] The Pho represents a photosensitive moiety, and the molecular weight of the moiety alone is preferably 90 or more, more preferably 100 or more, even more preferably 110 or more, and preferably 600 or less, more preferably 500 or less, and even more preferably 400 or less. When the molecular weight of the Pho moiety is within the above range, when the nonionic photobase generator is decomposed by exposure to light, the Pho moiety is less likely to volatilize, and diffusion, precipitation, or phase separation in a polyimide resin formed from a polyamic acid resin composition containing the nonionic base generator is less likely to occur. PI resins containing the Pho moiety tend to have increased adhesive strength with metals and a lower CTE.

[0113] The Pho moiety preferably has at least one polar functional group. Having a polar functional group makes it easier for the polar functional group to be ubiquitous at the interface between the PI resin and the metal when the PI resin and the metal are laminated, thereby improving the adhesive strength between the PI resin and the metal. The polar functional group is preferably a functional group that has electron-donating and electron-withdrawing properties and little steric hindrance, such as a methoxy group, an ethoxy group, a phenoxy group, a hydroxyl group, a nitro group, a cyano group, a carbonyl group, a carboxyl group, a halogen atom, a trifluoromethyl group, a carboxymethyl ester group, or a carboxyethyl ester group. More preferably, the polar functional group is a methoxy group, an ethoxy group, a hydroxyl group, a nitro group, a cyano group, a carbonyl group, a halogen atom, or a trifluoromethyl group. Still more preferably, the polar functional group is a hydroxyl group, a nitro group, a cyano group, or a carbonyl group. When the polar functional group is a hydroxyl group, a nitro group, a cyano group, or a carbonyl group, which are unlikely to cause steric hindrance, interaction is more likely to occur at the interface between the PI resin and the metal, and the adhesive strength between the PI resin and the metal is more likely to be improved.

[0114] The Pho moiety preferably has two or more aromatic ring structures, or a structure having at least one aromatic ring structure and at least one unsaturated bond. The aromatic ring structure and the unsaturated bond do not have to be conjugated with each other. The π-conjugated electrons of the multiple aromatic ring structures or unsaturated bonds form π-π interactions with the aromatic structure or imide skeleton of the PI resin, while easily forming coordinate interactions with the metal, which makes it easy to improve the adhesive strength at the interface between the PI resin and the metal.

[0115] In a preferred embodiment, Pho is represented by the following formulas (Pho1) to (Pho4): [In formulas (Pho1) to (Pho4), R １ ~R １０ are each independently any one of hydrogen, methyl, ethyl, phenyl, methoxy, ethoxy, phenoxy, hydroxyl, nitro, cyano, halogen, trifluoromethyl, carboxymethyl ester, and carboxyethyl ester; １ , X ２ , X ３are each independently a hydrogen atom, a methyl group, an ethyl group, or a cyano group.

[0116] In formulas (Pho1) to (Pho4), R １ ~R １０ are each independently preferably any one of hydrogen, methoxy, ethoxy, phenoxy, hydroxyl, nitro, and cyano, and more preferably any one of hydrogen, hydroxyl, nitro, and cyano. １ , X ２ , X ３ are preferably each independently any one of hydrogen, methyl, a nitro group and a cyano group.

[0117] In another preferred embodiment, Pho is represented by the following formulae (Pho5) to (Pho9): [In formula (Pho5), R １１ represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or Ar ２ represents Ar １ and Ar ２ each independently represents an aromatic ring which may have a substituent, n １ represents 0 or 1, and in formula (Pho6), R １２ ~R １６ are each independently a hydrogen atom, a cyano group, a nitro group, or —NR ３７ R ３８ , -OR ３７ , -COOR ３７ , -OCOR ３７ , -CO-R ３７ , -SR ３７ , a halogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, or an optionally substituted heterocyclic group having 2 to 20 carbon atoms; R ３７ and R ３８each independently represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, or an optionally substituted heterocyclic group having 2 to 20 carbon atoms; R １２ and R １３ , R １３ and R １４ , and R １４ and R １５ may be linked to each other to form a ring, in formula (Pho7), G represents a divalent aromatic group, in formula (Pho8), R １７ ~R ２７ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, a hydroxyl group, a halogen atom, or a cyano group, and in formula (Pho9), R ２８ ~R ３６ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkoxy group, a hydroxyl group, a halogen atom, or a cyano group; X １ represents an oxygen atom, a sulfur atom, a carbon atom, or a carbonyl group.

[0118] In formula (Pho5), R １１ Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, t-octyl, nonyl, isononyl, decyl, isodecyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, icosyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, and the like. These aliphatic hydrocarbon groups include -O-, -COO-, -OCO-, -CO-, -CS-, -S-, -SO-, -SO ２ The R and R' may be interrupted by -, -NR-, -NR-CO-, -CO-NR-, -NR-COO-, -OCO-NR- or -SiRR'- (however, these interrupting divalent groups are not adjacent to each other). The R and R' are unsubstituted aliphatic hydrocarbon groups, examples of which include R １１Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula include the same groups as those given as examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula:

[0119] In formula (Pho5), Ar １ and Ar ２ The aromatic rings represented by the formula (I) are each independently preferably an aromatic ring selected from the group consisting of a benzene ring, a naphthalene ring, a fluorene ring, a pyridine ring, a furan ring, a thiophene ring, an oxazole ring, an isoxazole ring, a thiadiazole ring, a carbazole ring, a benzofuran ring, a benzothiophene ring, a benzoxazole ring, a benzothiadiazole ring, a benzocarbazole ring, and a naphthofuran ring. １ and Ar ２ At least one of the rings is a carbazole ring, a benzoxazole ring, a benzothiadiazole ring, or a benzocarbazole ring.

[0120] In formula (Pho5), Ar １ and Ar ２ Examples of the substituent that the aromatic ring represented by the formula (I) may have include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a hydroxyl group, a thiol group, —COOH, SO ２ H, a hydrocarbon group having 1 to 20 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include R １１ In addition, phenyl, naphthyl, and fluorenyl are exemplified as the same groups as those exemplified as examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the formula: １１ In the case of phenyl, naphthyl, or fluorenyl, the linking portion to the aromatic ring may be -O-, -COO-, -OCO-, -CO-, -CS-, -S-, -SO-, or -SO ２ The R and R' may be interrupted once by -, -NR-, -NR-CO-, -CO-NR-, -NR-COO-, -OCO-NR- or -SiRR'-. The R and R' are unsubstituted aliphatic hydrocarbon groups, examples of which include R １１In formula (Pho5), n １ is preferably 0.

[0121] In formula (Pho6), R １２ ~R １６ Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0122] In formula (Pho6), R １２ ~R １６ , R ３７ and R ３８ Examples of the unsubstituted aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, t-octyl, nonyl, isononyl, decyl, isodecyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, icosyl, cyclopentyl, cyclohexyl, cyclohexylmethyl, etc. These aliphatic hydrocarbon groups include -O-, -COO-, -OCO-, -CO-, -CS-, -S-, -SO-, -SO ２ The R and R' may be interrupted by -, -NR-, -NR-CO-, -CO-NR-, -NR-COO-, -OCO-NR- or -SiRR'- (however, these interrupting divalent groups are not adjacent to each other). The R and R' are unsubstituted aliphatic hydrocarbon groups, examples of which include R １２ ~R １６ , R ３７ and R ３８ Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the formula (Pho6) include the same groups as those given as examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the formula (Pho6). １２ ~R １６ , R ３７ and R ３８ When the group represented by the formula (I) is interrupted or substituted by a group containing a carbon atom, the number of carbon atoms included in the number of carbon atoms is the specified number of carbon atoms.

[0123] In formula (Pho6), R１２ ~R １６ , R ３７ and R ３８ Examples of unsubstituted aromatic hydrocarbon groups having 6 to 20 carbon atoms represented by the formula (I) include phenyl, naphthyl, phenanthryl, pyrenyl, and biphenyl, as well as phenyl, naphthyl, phenanthryl, pyrenyl, and biphenyl substituted with an aliphatic hydrocarbon group. The alkylene moiety in these aromatic hydrocarbon groups is -O-, -COO-, -OCO-, -CO-, -CS-, -S-, -SO-, -SO ２ The aliphatic hydrocarbon group may be interrupted by -, -NR-, -NR-CO-, -CO-NR-, -NR-COO-, -OCO-NR-, or -SiRR'- (however, these interrupting divalent groups are not adjacent to each other). １２ ~R １６ , R ３７ and R ３８ The R and R' are unsubstituted aliphatic hydrocarbon groups, examples of which include the groups represented by R １２ ~R １６ , R ３７ and R ３８ Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula include the same groups as those given as examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula:

[0124] In formula (Pho6), R １２ ~R １６ , R ３７ and R ３８ Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms and having a substituent represented by the formula: and the aromatic hydrocarbon group having 6 to 20 carbon atoms and having a substituent represented by the formula: ２ and those substituted with H.

[0125] In formula (Pho6), R １２ ~R １６ , R ３７ and R ３８Examples of the unsubstituted heterocyclic group having 2 to 20 carbon atoms represented by the formula (I) include a tetrahydrofuran group, a dioxolanyl group, a tetrahydropyranyl group, a morpholylfuran group, a thiophene group, a methylthiophene group, a hexylthiophene group, a benzothiophene group, a pyrrole group, a pyrrolidine group, an imidazole group, an imidazolidine group, a pyrazole group, a pyrazolidine group, a piperidine group, and a piperazine group, as well as tetrahydrofuran groups, dioxolanyl groups, tetrahydropyranyl groups, morpholylfuran groups, thiophene groups, methylthiophene groups, hexylthiophene groups, benzothiophene groups, pyrrole groups, pyrrolidine groups, an imidazole group, an imidazolidine group, a pyrazole group, a pyrazolidine group, a piperidine group, and a piperazine group substituted with an aliphatic hydrocarbon group. The alkylene moiety in these heterocyclic groups and the bond between the heterocycle and the alkyl group may be -O-, -COO-, -OCO-, -CO-, -CS-, -S-, -SO-, or -SO ２ The aliphatic hydrocarbon group may be interrupted by -, -NR-, -NR-CO-, -CO-NR-, -NR-COO-, -OCO-NR-, or -SiRR'- (however, these interrupting divalent groups are not adjacent to each other). １２ ~R １６ , R ３７ and R ３８ The R and R' are unsubstituted aliphatic hydrocarbon groups, examples of which include the groups represented by R １２ ~R １６ , R ３７ and R ３８ Examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula include the same groups as those given as examples of the aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by the following formula:

[0126] In formula (Pho6), R １２ ~R １６ , R ３７ and R ３８ Examples of heterocyclic groups having 2 to 20 carbon atoms and having a substituent represented by the formula: ２and those substituted with H.

[0127] In formula (Pho7), G is a divalent aromatic group to which a formyl group (-C(=O)-H) is bonded, and which is bonded to the carbonyl group (-C(=O)-) in formula (N). The bonding positions of the formyl group and the carbonyl group in G are in an ortho-position relationship with each other. In other words, of the atoms constituting the ring skeleton of G, the atom to which the formyl group is bonded and the atom to which the carbonyl group is bonded are adjacent to each other in the ring skeleton of G and are directly bonded to each other.

[0128] In formula (Pho7), the divalent aromatic group represented by G may be either a divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group, or may be a divalent group formed by condensing an aromatic hydrocarbon group and an aromatic heterocyclic group (in the present disclosure, such a group is treated as an aromatic heterocyclic group). Furthermore, these aromatic hydrocarbon groups and aromatic heterocyclic groups may have a substituent. The divalent aromatic group represented by G may be either monocyclic or polycyclic, and the number of atoms constituting the ring skeleton (number of ring members) is not limited, but is preferably 3 to 20.

[0129] In formula (Pho7), examples of the divalent aromatic hydrocarbon group represented by G include a 1,2-phenylene group, a naphthalene-1,2-diyl group, a naphthalene-2,3-diyl group, a toluene-2,3-diyl group, a toluene-3,4-diyl group, an o-xylene-3,4-diyl group, an o-xylene-4,5-diyl group, an m-xylene-4,5-diyl group, a p-xylene-2,3-diyl group, an anthracene-1,2-diyl group, and an anthracene-2,3-diyl group. One or more hydrogen atoms of these aromatic hydrocarbon groups may be substituted with a substituent such as the above-mentioned aromatic hydrocarbon group or alkyl group. The number of carbon atoms in the substituted aromatic hydrocarbon group, including the number of carbon atoms of the substituent, is preferably 6 to 20.

[0130] In formula (Pho7), the alkyl group as the substituent (hereinafter also referred to as a "substituted alkyl group") may be linear, branched, or cyclic, and if cyclic, may be monocyclic or polycyclic. The number of carbon atoms in the substituted alkyl group is preferably 1 to 10.

[0131] In formula (Pho7), the linear or branched substituted alkyl group preferably has 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a 1-methylbutyl group, an n-hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 4-methylpentyl group, a 5-methylpentyl group, a 6-methylpentyl group, a 7-methylpentyl group, a 8-methylpentyl group, a 9-methylpentyl group, a 10-methylpentyl group, a 11-methylpentyl group, a 12-methylpentyl group, a 13-methylpentyl group, a 14-methylpentyl group, a 15-methylpentyl group, a 16-methylpentyl group, a 17-methylpentyl group, a 18-methylpentyl group, a 20-methylpentyl group, a 22-methylpentyl group, a 23-methylpentyl group, a 24-methylpentyl group, a 25-methylpentyl group, a 26-methylpentyl group, a 27-methylpentyl group, a 28-methylpentyl group, a 29-methylpentyl group, a 30-methylpentyl group, a 31-methylpentyl group, a 32-methylpentyl group, a 33-methylpentyl group, a 34-methylpentyl group, a 35-methylpentyl group, a 36-methylpentyl group, a 37-methylpentyl group, a 38-methylpentyl group, a 39-methylpentyl group, a 39-methylpentyl group, a 39-methylpentyl group, a 39-methylpentyl group, a 39- Examples of alkyl groups include octyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, n-octyl, isooctyl, 2-ethylhexyl, nonyl, and decyl groups.

[0132] In formula (Pho7), the cyclic substituted alkyl group preferably has 3 to 10 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, an isobornyl group, a 1-adamantyl group, a 2-adamantyl group, and a tricyclodecyl group. One or more hydrogen atoms in these cyclic alkyl groups may be substituted with a linear, branched, or cyclic alkyl group. Examples of the linear, branched, and cyclic alkyl groups substituting the hydrogen atoms include the same groups as the substituted alkyl groups described above.

[0133] In formula (Pho7), examples of the aromatic heterocyclic group represented by G include groups obtained by removing two hydrogen atoms bonded to the carbon atoms or heteroatoms constituting the ring structure from various aromatic heterocyclic compounds.Preferred examples of the aromatic heterocyclic compound include compounds having one or more sulfur atoms as atoms constituting the aromatic heterocyclic structure (sulfur-containing aromatic heterocyclic compounds), compounds having one or more nitrogen atoms as atoms constituting the aromatic heterocyclic structure (nitrogen-containing aromatic heterocyclic compounds), compounds having one or more oxygen atoms as atoms constituting the aromatic heterocyclic structure (oxygen-containing aromatic heterocyclic compounds), and compounds having two different heteroatoms selected from the group consisting of sulfur atoms, nitrogen atoms, and oxygen atoms as atoms constituting the aromatic heterocyclic structure.Examples of the sulfur-containing aromatic heterocyclic compounds include thiophene and benzothiophene. Examples of the nitrogen-containing aromatic heterocyclic compound include pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole, isoindole, benzimidazole, purine, indazole, quinoline, isoquinoline, quinoxaline, quinazoline, and cinnoline. Examples of the oxygen-containing aromatic heterocyclic compound include furan, benzofuran (1-benzofuran), and isobenzofuran (2-benzofuran). Examples of compounds having the above-mentioned two different heteroatoms as atoms constituting the aromatic heterocyclic skeleton include oxazole, isoxazole, thiazole, benzoxazole, benzisoxazole, and benzothiazole.

[0134] In formula (Pho7), among the atoms constituting the ring skeleton of the aromatic heterocyclic group, the atom to which the formyl group is bonded and the atom to which the carbonyl group is bonded may each be a carbon atom or a hetero atom, but it is preferable that both are carbon atoms. In the aromatic heterocyclic group, the number of hetero atoms constituting the ring skeleton is preferably 1 to 3, more preferably 1 or 2. When the number of hetero atoms is 2 or more, these hetero atoms may be the same or different.

[0135] In Formula (Pho7), examples of the substituent possessed by the aromatic hydrocarbon group or aromatic heterocyclic group represented by G include the substituted alkyl group, alkoxy group, aryloxy group, dialkylamino group, diarylamino group, alkylarylamino group, alkylcarbonyl group, arylcarbonyl group, alkyloxycarbonyl group, aryloxycarbonyl group, alkylcarbonyloxy group, arylcarbonyloxy group, alkylthio group, arylthio group, cyano group (-CN), halogen atom, nitro group, haloalkyl group (halogenated alkyl group), hydroxyl group (-OH), mercapto group (-SH), amino group, the aromatic hydrocarbon group, and the aromatic heterocyclic group. The number of the substituents may be one or more, and all hydrogen atoms may be substituted with the substituent. The number of the substituents depends on the number of substitutable hydrogen atoms, but is preferably, for example, one to four, more preferably one to three, and even more preferably one or two. When the number of the substituents is two or more, these substituents may be the same or different from each other.

[0136] Examples of the alkoxy group as a substituent include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a cyclopropoxy group, and other monovalent groups in which the substituted alkyl group is bonded to an oxygen atom.

[0137] In the aryloxy group that is a substituent, the aryl group bonded to the oxygen atom may be either monocyclic or polycyclic, and preferably has 6 to 10 carbon atoms. Examples of such aryl groups include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, and a xylyl group (dimethylphenyl group). One or more hydrogen atoms of these aryl groups may be further substituted with such an aryl group, the substituted alkyl group, or the like. The aryl group having such a substituent preferably has 6 to 10 carbon atoms, including the carbon atoms of the substituent.

[0138] Examples of the dialkylamino group as a substituent include an amino group (—NH ２) are substituted with the substituted alkyl group. In the dialkylamino group, the two alkyl groups bonded to the nitrogen atom may be the same or different. Examples of the diarylamino group as a substituent include monovalent groups in which two hydrogen atoms of an amino group are substituted with the aryl group, such as a diphenylamino group and a phenyl-1-naphthylamino group. In the diarylamino group, the two aryl groups bonded to the nitrogen atom may be the same or different. Examples of the alkylarylamino group as a substituent include monovalent groups in which one hydrogen atom of the two hydrogen atoms of an amino group is substituted with the substituted alkyl group and the other hydrogen atom is substituted with the aryl group, such as a methylphenylamino group.

[0139] Examples of the alkylcarbonyl group as a substituent include a monovalent group in which the substituted alkyl group is bonded to a carbonyl group (-C(=O)-), such as a methylcarbonyl group (acetyl group). Examples of the arylcarbonyl group as a substituent include a monovalent group in which the aryl group is bonded to a carbonyl group, such as a phenylcarbonyl group (benzoyl group).

[0140] Examples of the alkyloxycarbonyl group as a substituent include a monovalent group in which the alkoxy group is bonded to a carbonyl group, such as a methyloxycarbonyl group (methoxycarbonyl group), etc. Examples of the aryloxycarbonyl group as a substituent include a monovalent group in which the aryloxy group is bonded to a carbonyl group, such as a phenyloxycarbonyl group (phenoxycarbonyl group).

[0141] Examples of the alkylcarbonyloxy group as a substituent include a monovalent group in which the substituted alkyl group is bonded to a carbon atom of a carbonyloxy group (-C(=O)-O-), such as a methylcarbonyloxy group. Examples of the arylcarbonyloxy group as a substituent include a monovalent group in which the aryl group is bonded to a carbon atom of a carbonyloxy group, such as a phenylcarbonyloxy group.

[0142] Examples of the alkylthio group as a substituent include monovalent groups in which the substituted alkyl group is bonded to a sulfur atom, such as a methylthio group, an ethylthio group, an n-propylthio group, an isopropylthio group, and a cyclopropylthio group. Examples of the arylthio group as a substituent include monovalent groups in which the aryl group is bonded to a sulfur atom, such as a phenylthio group, a 1-naphthylthio group, and a 2-naphthylthio group.

[0143] Examples of the halogen atom as a substituent include a fluorine atom (-F), a chlorine atom (-Cl), a bromine atom (-Br), and an iodine atom (-I). Examples of the haloalkyl group as a substituent include groups in which one or more hydrogen atoms of the substituted alkyl group are substituted with a halogen atom. Examples of halogen atoms in the haloalkyl group include those previously exemplified as halogen atoms as substituents. The number of halogen atoms in the haloalkyl group is not particularly limited and may be one or two or more. When the number of halogen atoms in the haloalkyl group is two or more, these multiple halogen atoms may be the same or different. The haloalkyl group may be a perhaloalkyl group in which all hydrogen atoms in the alkyl group are substituted with halogen atoms. Specific examples of haloalkyl groups include a chloromethyl group, a dichloromethyl group, a trichloromethyl group, and a trifluoromethyl group.

[0144] In formula (Pho7), the substitution position of the substituent on the aromatic hydrocarbon group or aromatic heterocyclic group is not particularly limited.

[0145] In one embodiment of the present invention, the amino group represented by Am in formula (N) preferably contains one or more nitrogen atoms, more preferably one or more tertiary nitrogen atoms. In one embodiment of the present invention, it is preferred that the nitrogen atom in the amino group represented by Am is bonded to the carbon atom in the carbonyl group in formula (N).

[0146] The Am is preferably an amino group derived from any of azoles, piperidines, guanidines and amidines.

[0147] Specific preferred examples of the nonionic photobase generator represented by formula (N) include the following compounds.

[0148] The nonionic photobase generator usable in the present invention can be produced by a known method. Alternatively, commercially available nonionic photobase generators can be used, examples of which include WPBG-018, WPBG-140, WPBG-165, and WPBG-027 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0149] The amount of the nonionic photobase generator used may be appropriately selected depending on the types of polyamic acid resin and nonionic photobase generator used, the thickness of the cured film of the photosensitive resin composition, the type of solvent, if used, and / or the wavelength of light exposure. From the viewpoint of good imidization, the amount of the nonionic photobase generator is, for example, 1 to 40 parts by mass, preferably 3 to 35 parts by mass, and more preferably 7 to 30 parts by mass, relative to 100 parts by mass of the polyamic acid resin.

[0150] <Optional Components> The photosensitive resin composition of the present invention may optionally contain other components in addition to the polyamic acid resin and the nonionic photobase generator. For example, a solvent may be included. Such a solvent is not particularly limited as long as it dissolves the polyamic acid resin, the nonionic photobase generator, and other optional components. Examples of the solvent include alcohol-based solvents such as water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1-methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; phenol-based solvents such as phenol and cresol; ester-based solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, propylene glycol methyl ether acetate, and ethyl lactate; lactone-based solvents such as γ-butyrolactone (hereinafter sometimes referred to as GBL) and γ-valerolactone; ketone-based solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; and pentane, heptane, and the like. Examples of suitable solvents include aliphatic hydrocarbon solvents such as hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene, N,N'-dimethylacetamide, N,N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, pyridine, γ-butyrolactone, and diethylene glycol monomethyl ether. These solvents may be used alone or in combination of two or more.The amount of the solvent used may be appropriately selected depending on the viscosity of the photosensitive resin composition and / or the film thickness of the cured film of the photosensitive resin composition, and may be used in the range of, for example, 50 to 9000 parts by mass, preferably 70 to 5000 parts by mass, and more preferably 100 to 1000 parts by mass relative to 100 parts by mass of the polyamic acid resin.

[0151] Examples of optional components other than the solvent include sensitizers, adhesion aids, base amplifiers, dyes, surfactants, leveling agents, plasticizers, and fine particles. Known optional components can be used in appropriate amounts as long as they do not impair the effects of the present invention. The total amount of optional components other than the solvent is usually 0 to 10 parts by mass, preferably 0 to 5 parts by mass, per 100 parts by mass of the polyamic acid resin.

[0152] [Method for preparing photosensitive resin composition] The photosensitive resin composition can be prepared by mixing the polyamic acid resin, the nonionic photobase generator, and optional components, if added, preferably in the above-mentioned proportions using a known method. In preparing the photosensitive resin composition, a polyamic acid resin solution obtained by appropriately diluting a reaction solution containing the polyamic acid resin obtained by synthesizing the polyamic acid resin with a solvent as needed can also be used instead of the polyamic acid resin.

[0153] [Cured Film] The photosensitive resin composition of the present invention can produce a uniform cured film due to its excellent film-forming properties and / or stability over time. Therefore, the present invention also relates to a cured film of the photosensitive resin composition of the present invention. Because the cured film is an imidized product (PI resin) of the polyamic acid resin with a nonionic photobase generator, it has a high imidization rate and excellent adhesive strength to metals even when imidized at low temperatures. Furthermore, because the cured film is derived from a photosensitive resin composition, it can easily have a desired patterned shape by using a mask.

[0154] The imidization ratio in the cured film of the present invention is preferably 90% or more, more preferably 93% or more, and even more preferably 95% or more, and is usually 100% or less. From the viewpoint of the adhesive strength of the cured film to metal, it is preferable that the imidization ratio is equal to or greater than the above-mentioned lower limit. The imidization ratio indicates the ratio of the molar amount of imide bonds in the PI resin to twice the molar amount of structural units derived from tetracarboxylic acid anhydrides in the PI resin. Note that, when the PI resin contains a tricarboxylic acid compound, the imidization ratio indicates the ratio of the molar amount of imide bonds in the PI resin to the sum of twice the molar amount of structural units derived from tetracarboxylic acid anhydrides in the PI resin and the molar amount of structural units derived from tricarboxylic acid compounds. The imidization ratio can be determined by IR or NMR, for example.

[0155] [Method for Producing Cured Film] The cured film of the present invention can be produced, for example, by a method comprising: (1) a step of applying the photosensitive resin composition to a substrate and drying it to obtain a coating film; and (2) a step of heat-treating the dried coating film.

[0156] The coating in step (1) can be carried out by a method commonly used for coating photosensitive resin compositions. For example, coating can be carried out using a spin coater, bar coater, blade coater, curtain coater, or screen printing machine, spray coating using a spray coater, or inkjet coating. Drying (prebaking) of the coating film can also be carried out by a commonly used method, such as air drying, heat drying using an oven or hot plate, or vacuum drying. Drying of the coating film is preferably carried out under conditions that do not cause imidization of the polyamic acid resin in the photosensitive resin composition. Specifically, the drying is carried out at a temperature of, for example, 20°C to 180°C, preferably 40°C to 160°C, and more preferably 50°C to 140°C. The predrying time is, for example, 1 minute to 12 hours, preferably 5 minutes to 1 hour. One drying method may be used, or two or more drying methods may be combined. The substrate may be selected appropriately depending on its intended use and is not particularly limited. Examples of such compositions include protective films for silicon wafers, wiring boards, chips, various resins, metals, and semiconductor devices. The cured film of the photosensitive resin composition of the present invention has excellent adhesion to metals (especially copper, silver, gold, and aluminum), making it particularly suitable for use when the adherend is a metal or a material containing a metal. Furthermore, since the photosensitive resin composition of the present invention can achieve sufficient imidization even at low temperatures, it can be used as a substrate even for substrates that are not suitable for high-temperature treatment.

[0157] The pre-dried coating film is then heat-treated in step (2) to imidize the polyamic acid resin (post-baking). Since the photosensitive resin composition of the present invention contains a polyamic acid resin and a nonionic photobase generator, it is sufficiently imidized even at low temperatures. Therefore, the heat treatment temperature may be lower than the temperatures typically employed in conventional techniques, and may be, for example, 120 to 320°C, 140 to 300°C, 160 to 280°C, or 180 to 260°C.

[0158] In one embodiment of the present invention, when imidizing a polyamic acid resin, the temperature is increased from the initial temperature to the imidization temperature (the highest temperature in the imidization treatment temperature) in a single step or in two or more steps. In one embodiment of the present invention, the temperature increase rate is preferably 1° C. / min or more, more preferably 3° C. / min or more, and preferably 25° C. / min or less, more preferably 20° C. / min or less. The temperature increase time from the initial temperature to the imidization temperature can be appropriately selected depending on the temperature and the temperature increase rate, and is preferably 5 hours or less, more preferably 3 hours or less, even more preferably 2 hours or less, particularly preferably 1 hour or less, and also preferably 10 minutes or more, more preferably 15 minutes or more, and even more preferably 20 minutes or more.

[0159] In one embodiment of the present invention, it is preferable to include a step of maintaining the imidization temperature for a certain period of time after the temperature has been reached. The maintenance time can be appropriately selected depending on the type of polyamic acid resin and nonionic photobase generator contained in the photosensitive resin composition and / or the cured film thickness, and is, for example, 1 minute to 12 hours, preferably 5 minutes to 4 hours. Heating can be performed using conventionally known devices, such as a hot plate, an oven, or a temperature-programmable heating oven. The heat treatment atmosphere may be air or an inert gas such as nitrogen or argon.

[0160] In one embodiment of the present invention, the cured film can have a patterned shape. Such a cured film can be produced, for example, by a method comprising, after the step (1), the following steps: (1-1) exposing the resulting coating film through a photomask having a pattern; (1-2) heat-treating the exposed coating film; and (1-3) treating the heated coating film with a developer.

[0161] The actinic light used for exposure in step (1-1) is light having a wavelength capable of exciting the nonionic photobase generator to generate a base. Examples of usable exposure light sources include ultraviolet light such as i-line, g-line, and h-line, KrF excimer laser, and ArF excimer laser. Conventional exposure devices can be used, and examples thereof include contact aligners, mirror projection devices, steppers, and laser direct exposure devices.

[0162] The exposure intensity may be appropriately determined depending on the type and amount of the nonionic photobase generator, the coating film thickness, the absorbance of the coating film, etc., and may be, for example, 100 to 4000 mJ / cm ２ It is preferable that the amount of light emitted is about the same (equivalent to the amount of light emitted at a wavelength of 365 nm).

[0163] By the heat treatment in step (1-2), the base generated in the exposed areas acts as a catalyst, resulting in partial imidization of the polyamic acid resin. The temperature and time of the heat treatment are appropriately selected depending on the type of polyamic acid resin and nonionic photobase generator contained in the photosensitive resin composition and / or the coating thickness. For example, when the coating thickness to be heat treated is about 30 μm, it is typically preferable to heat at 80 to 200° C. for 1 to 120 minutes. By appropriately controlling the heating temperature, imidization in the exposed areas can be efficiently achieved, and a desired pattern can be formed by generating a difference in solubility in a developer between the exposed and unexposed areas.

[0164] In step (1-3), the coating film is treated with a developer to remove the photosensitive resin composition from unexposed areas of the coating film. This allows for the formation of a patterned cured film containing a PI resin on the substrate. The cured film may contain the nonionic photobase generator contained in the polyamic acid resin composition. Conventional development methods can be employed, including rotary spraying, paddle spraying, and immersion with ultrasonic treatment. Conventional developers can be used, including aqueous solutions of inorganic alkalis such as sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, sodium silicate, and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine; and quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide. The solvents described in the "Optional Components" section above can also be used as the developer. If necessary, water-soluble organic solvents such as methanol, ethanol, and isopropyl alcohol, and / or surfactants may be added to the developer. After treatment with the developer, the coating film may be washed with a rinse solution, if necessary. Examples of the rinse solution include water (distilled water), methanol, ethanol, isopropanol, and mixtures of two or more of these.

[0165] After the step (1-3), the imidization step (step (2)) is carried out, whereby a cured film having a patterned shape can be obtained.

[0166] [Semiconductor Package] The cured film of the present invention is a PI resin film, and therefore has excellent insulating properties, heat resistance, and mechanical strength. Therefore, it can be suitably used in applications requiring such functions, such as electronic and electrical components, optical components, building materials, lighting element sealing components, and sensor components. Therefore, the present invention also covers semiconductor packages containing the cured film of the present invention. Materials other than the cured film of the present invention contained in the semiconductor package can be those commonly used in the art.

[0167] The semiconductor package of the present invention can have excellent resistance to external forces such as chemical mechanical polishing and impact during the manufacturing process, as well as to the usage environment, due to the high adhesive strength between the cured film of the present invention and the metal. The adhesive strength can be evaluated by a peel strength determined by a peel test at the interface between the cured film and the metal, and the peel strength is preferably 0.55 kN or more, more preferably 0.70 kN or more. Furthermore, as described above, the cured film of the present invention can be easily patterned and can have a high imidization rate even at low temperatures. Therefore, the semiconductor package of the present invention can be manufactured with high productivity and yield, and can also have high reliability.

[0168] EXAMPLES The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0169] The abbreviations used in the examples and comparative examples represent the following compounds: BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride PMDA: pyromellitic anhydride DDA: dimer diamine ("PRIAMINE 1075" manufactured by Croda Japan Co., Ltd.) DMAc: dimethylacetamide m-Tb: 4,4'-diamino-2,2'-dimethylbiphenyl WPBG-140: 1-(anthraquinone-2-yl)ethylimidazole-1-carboxylate, a non-ionic photobase generator manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0170] 1. Synthesis of Polyamic Acid Resin Solution (Synthesis Example 1) Polyamic Acid Resin Solution 1 21.60 g (39.66 mmol) of DDA was dissolved in 139.0 g of DMAc. The resulting solution was heated to 70°C with stirring. 13.14 g (44.67 mmol) of BPDA was added to the solution and stirred for 1 hour. 266.1 g of DMAc and 33.67 g (158.6 mmol) of m-Tb were added to the resulting solution and dissolved, followed by the addition of 32.86 g (150.6 mmol) of PMDA and stirring for 3 hours to obtain Polyamic Acid Resin Solution 1 containing a polyamic acid resin, which is a block copolymer. The molar ratio of diamine monomer to acid dianhydride monomer used was 1.015.

[0171] Synthesis Example 2: Polyamic Acid Resin Solution 2: 3.848 g (7.066 mmol) of DDA was dissolved in 24.80 g of DMAc. The resulting solution was heated to 70°C with stirring. 2.352 g (7.993 mmol) of BPDA was added to the solution and stirred for 1 hour. 46.62 g of DMAc and 6.000 g (28.26 mmol) of m-Tb were added to the resulting solution and dissolved, followed by the addition of 5.656 g (25.93 mmol) of PMDA and stirring for 3 hours to obtain Polyamic Acid Resin Solution 2 containing a polyamic acid resin that is a block copolymer. The molar ratio of diamine monomer to acid dianhydride monomer used was 1.041.

[0172] Synthesis Example 3: Polyamic Acid Resin Solution 3: 4.490 g (8.243 mmol) of DDA and 7.000 g (32.97 mmol) of m-Tb were dissolved in 83.3 g of DMAc. The resulting solution was heated to 70°C with stirring. 2.744 g (9.325 mmol) of BPDA and 6.597 g (30.25 mmol) of PMDA were added to the solution, and the mixture was stirred for 1 hour to dissolve the PMDA. The mixture was then stirred for 3 hours to obtain Polyamic Acid Resin Solution 3, which contained a random copolymer polyamic acid resin. The molar ratio of diamine monomer to acid dianhydride monomer used was 1.041.

[0173] Example 1 Photosensitive resin composition 1 was obtained by adding 2.125 g of WPBG-140 to 104.4 g of polyamic acid resin solution 1 and stirring for 1 hour. The amount of nonionic photobase generator relative to 100 parts by mass of polyamic acid resin was approximately 10.2 parts by mass. Photosensitive resin composition 1 was applied to the roughened surface (surface roughness; Rz = 0.6 μm) of electrolytic copper foil (thickness 12 μm) to a dry thickness of 30 μm to obtain a coating film. The coating film was dried by heating at 80°C for 30 minutes to obtain a laminate of the dried coating film and electrolytic copper foil, and then the integrated i-line exposure value was 480 mJ / cm. ２The laminate was fixed to a metal frame and heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere with an oxygen concentration of 0.02 vol %, and then heated for 5 minutes to perform imidization, thereby obtaining a laminate (single-sided copper-clad laminate 1) of a cured film of photosensitive resin composition 1 and electrolytic copper foil. A 2 mm wide protective tape was attached to the copper foil surface of the obtained single-sided copper-clad laminate 1, and the laminate was immersed in a large volume of a 40 mass % aqueous ferric chloride solution at room temperature for 10 minutes, then removed, and the adhering ferric chloride aqueous solution was washed with pure water. After visually confirming that no copper remained other than in the areas protected by the protective tape, the protective tape was peeled off and the film was dried at 80 ° C. for 1 hour to obtain a polyimide resin film 1 having a 2 mm wide copper foil circuit.

[0174] Example 2 0.8205 g of WPBG-140 was added to 41.00 g of polyamic acid resin solution 2 and stirred for 1 hour to obtain photosensitive resin composition 2. The amount of nonionic photobase generator per 100 parts by mass of polyamic acid resin was approximately 10.0 parts by mass. A polyimide resin film 2 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that photosensitive resin composition 2 was used instead of photosensitive resin composition 1.

[0175] Example 3 1.113 g of WPBG-140 was added to 55.64 g of polyamic acid resin solution 3 and stirred for 1 hour to obtain photosensitive resin composition 3. The amount of nonionic photobase generator per 100 parts by mass of polyamic acid resin was approximately 10.0 parts by mass. A polyimide resin film 3 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that photosensitive resin composition 3 was used instead of photosensitive resin composition 1.

[0176] Comparative Example 1: 0.0410 g of 1,5-diazabicyclo[4.3.0]non-5-ene 2-(9-oxoxanthen-2-yl)propionate (ionic photobase generator) was added to 2.05 g of polyamic acid resin solution 1 and stirred for 24 hours, but the solution was not completely dissolved and the viscosity of the mixture increased. A resin composition was not obtained, and film formation was not possible.

[0177] Comparative Example 2 A polyimide resin film 4 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that the polyamic acid resin solution 1 was used instead of the photosensitive resin composition 1.

[0178] Comparative Example 3 A polyimide resin film 5 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that the polyamic acid resin solution 2 was used instead of the photosensitive resin composition 1.

[0179] Comparative Example 4 A polyimide resin film 6 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that the polyamic acid resin solution 3 was used instead of the photosensitive resin composition 1.

[0180] Comparative Example 5 0.5101 g of imidazole (not a photobase generator) was added to 50.59 g of polyamic acid resin solution 3 and stirred for 1 hour to obtain photosensitive resin composition 5. A polyimide resin film 7 having a copper foil circuit with a width of 2 mm was obtained in the same manner as in Example 1, except that photosensitive resin composition 5 was used instead of photosensitive resin composition 1.

[0181] The resin compositions and their cured products (polyimide resin films) obtained in the Examples and Comparative Examples were subjected to the following measurements and evaluations. <Additive Solubility> Each additive (photobase generator or imidazole) was added to each polyamic acid resin solution in the same proportion as in each Example and Comparative Example. While stirring at a speed of 150 rpm at room temperature, it was evaluated whether the additive dissolved within 24 hours from the start of stirring. Those that dissolved were evaluated as ◯, and those that did not completely dissolve were evaluated as ×.

[0182] <Stability over time> The resin compositions obtained in Examples 1 to 3 were left in the air at 5°C for one week to check whether their viscosities changed. In all cases, the viscosity change was 10% or less, demonstrating excellent stability over time. The viscosity of the resin compositions was confirmed using a digital viscometer (DV2T, manufactured by Brookfield).

[0183] <Measurement of Imidization Ratio> The imidization ratio of the polyimide resin film was calculated by infrared spectroscopy (IR, apparatus: FT-670 manufactured by Varian) using the apparatus shown below. Specifically, the imidization ratio of the dried coating film in a laminate with an electrolytic copper foil obtained by heating each of the above-mentioned polyamic acid resin solutions 1, 2, and 3 at 80°C for 30 minutes was set to 0%, and the imidization ratio of the cured film in a single-sided copper-clad laminate obtained by raising the temperature from room temperature to 360°C over 1 hour in a nitrogen atmosphere with an oxygen concentration of 0.02% by volume and heating at 360°C for 5 minutes was set to 100%, and the imidization ratio of the peak (approximately 1500 cm) that remains unchanged by curing was set to 0%. －１ When normalized with the peak derived from the imide group (approximately 1370 cm ; derived from the benzene ring C═C), －１ The imidization rate of the polyimide resin film was calculated from the peak intensity ratio of the imide group C—N (derived from the imide group C—N). Imidization rate [%] = [{1370(sample)−1370(initial)} / {1370(imide)−1370(initial)}]×100. In the above formula, 1370(sample), 1370(initial), and 1370(imide) each represent the peak intensity of about 1370 cm when the polyimide resin films obtained in the examples and comparative examples were subjected to IR analysis. －１ and a peak intensity of about 1370 cm when the dried coating film obtained by heating at 80° C. for 30 minutes was subjected to IR analysis. －１ and the peak intensity of about 1370 cm when the cured film obtained by heating at 360° C. for 5 minutes was subjected to IR analysis. －１ The imidization ratio was calculated using the values ​​of the peak intensity of 1370 (initial) and 1370 (imide) obtained from the dried coating film and cured film of polyamic acid resin solution 1 for polyimide resin film 1 and polyimide resin film 4, the values ​​of the dried coating film and cured film of 1370 (initial) and 1370 (imide) obtained from polyamic acid resin solution 2 for polyimide resin film 2 and polyimide resin film 5, and the values ​​of the dried coating film and cured film of 1370 (initial) and 1370 (imide) obtained from polyamic acid resin solution 3 for polyimide resin film 3 and polyimide resin film 6.

[0184] <Measurement of Peel Strength (Adhesive Strength)> Adhesive strength was evaluated by conducting a peel test at the interface between the copper foil and the resin film in the laminate. A polyimide-based resin film with a 2 mm-wide copper foil circuit was cut into a width of 10 mm and a length of 120 mm to obtain a test specimen. The 2 mm-wide copper foil circuit was cut so that it was positioned at the center of the width of the test specimen. The side of the test specimen without the copper foil circuit was fixed to an aluminum plate with double-sided tape. The 2 mm-wide copper foil circuit was peeled from the polyimide-based resin film of the test specimen at a speed of 10 mm / s for approximately 20 mm in a direction 90° to the test specimen, and the minimum peel strength was determined using a tensile tester (Shimadzu Corporation, product name: Small Desktop Tester EZ-L).

[0185]

Claims

1. A photosensitive resin composition comprising a polyamic acid resin having a structural unit (A) derived from a tetracarboxylic acid anhydride and a structural unit (B) derived from a diamine, and a nonionic photobase generator.

2. The structural unit (B) is represented by the following formula (B1): [In the formula, X １ is an aliphatic group having 14 or more carbon atoms.

3. The photosensitive resin composition according to claim 2, wherein the aliphatic diamine represented by formula (B1) is a dimer diamine.

4. X in the formula (B1) １ The photosensitive resin composition according to claim 2 , wherein is a saturated aliphatic group having 14 or more carbon atoms.

5. The aliphatic diamine represented by the formula (B1) is a diamine represented by the following formula (b1): [wherein m, n, p, and q each independently represent a number from 3 to 24, and the sum of m, n, p, and q is 12 to 60].

6. The photosensitive resin composition according to claim 5, wherein the sum of m and n in formula (b1) is 6 to 40, and the sum of p and q is 6 to 40.

7. The structural unit (A) is represented by the formula (A1): [In the formula, R ａ１ each independently represent a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and each 1 is independently an integer of 0 to 3], and / or a structural unit (A1) derived from a tetracarboxylic acid anhydride represented by formula (A2): [In the formula, R ａ２ each independently represent a halogen atom, or an alkyl group, alkoxy group, aryl group, or aryloxy group which may have a halogen atom, and k represents an integer of 0 to 2.

8. The nonionic photobase generator is represented by the following formula (N): [wherein Pho is an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, and Am is an amino group having 1 to 20 carbon atoms].

9. The Pho is represented by the following formulas (Pho1) to (Pho4): [In the formula, R １ ~R １０ are each independently any one of hydrogen, methyl, ethyl, phenyl, methoxy, ethoxy, phenoxy, hydroxyl, nitro, cyano, halogen, trifluoromethyl, carboxymethyl ester, and carboxyethyl ester; １ , X ２ , X ３ and each independently represents a hydrogen atom, a methyl group, an ethyl group, or a cyano group.

10. The photosensitive resin composition according to claim 8, wherein the amino group represented by Am contains a tertiary nitrogen.

11. The photosensitive resin composition according to claim 8, wherein in formula (N), a carbon atom in the carbonyl group is bonded to a nitrogen atom in the amino group represented by Am.

12. The photosensitive resin composition according to claim 8, wherein Am is an amino group derived from any one of azoles, piperidines, guanidines, and amidines.

13. A cured film of the photosensitive resin composition according to claim 1.

14. A semiconductor package comprising the cured film according to claim 13.

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