WO2025094401A1 - Resin composition, cured object, method for producing cured object, and electronic component - Google Patents

Abstract

Provided is a resin composition comprising a polyimide component including a polyimide precursor and/or a polyimide resin and a metal chelating agent. The polyimide component, in a cured state, has a degree of cyclization of 80% or less, or the resin composition further contains a thermal radical generator.

Description

Resin composition, cured product, method for producing cured product, and electronic component

This disclosure relates to a resin composition, a cured product, a method for producing the cured product, and an electronic component.

Polyimide resin, which has excellent heat resistance as well as electrical and mechanical properties, is widely used as a material for resin films used as surface protective films for elements in semiconductor devices, interlayer insulating films, etc. In recent years, it has been proposed to form resin films by pattern exposure using polyimide resins that have been given photosensitivity (see, for example, Patent Document 1).

Patent document 1: JP 2021-85977 A

A cured product formed using a polyimide resin as described in Patent Document 1 is required to have a reduced thermal expansion coefficient in order to prevent peeling from a substrate or an electrode due to expansion and contraction of the cured product.
An object of one embodiment of the present disclosure is to provide a resin composition that can provide a cured product having a small thermal expansion coefficient. Another object of the present disclosure is to provide a cured product obtained using the resin composition, a method for producing the cured product, and an electronic component.

Specific means for achieving the above object are as follows.
<1> a polyimide component containing at least one of a polyimide precursor and a polyimide resin;
a metal chelating agent,
A resin composition, wherein the cyclization rate of the polyimide component in a cured state is 80% or less.
<2> a polyimide component containing at least one of a polyimide precursor and a polyimide resin;
A metal chelating agent;
A resin composition comprising:
<3> The resin composition according to <1> or <2>, further comprising a photopolymerization initiator.
<4> The resin composition according to any one of <1> to <3>, wherein the metal chelating agent includes a titanium chelating agent or a zirconium chelating agent.
<5> A cured product of the resin composition according to any one of <1> to <4>.
<6> A method for producing a cured product, comprising: forming a layer of the resin composition according to any one of <1> to <4> on a substrate; and curing the layer of the resin composition.
<7> An electronic part comprising a cured product of the resin composition according to any one of <1> to <4>.

According to one embodiment of the present disclosure, a resin composition is provided that can produce a cured product with a small thermal expansion coefficient. According to one embodiment of the present disclosure, a cured product obtained using this resin composition, a method for producing the cured product, and an electronic component are also provided.

1A to 1C are diagrams illustrating a manufacturing process for an electronic component according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments.
In the present disclosure, constituent elements (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and do not limit the present disclosure.
In the present disclosure, the term "step" includes not only a step that is independent of other steps, but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.
In the present disclosure, the numerical ranges indicated using "to" include the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.
In the present disclosure, each component may contain multiple types of corresponding substances. When multiple types of substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified.
In the present disclosure, the terms "layer" and "film" include cases where the layer or film is formed over the entire area when the area in which the layer or film is present is observed, as well as cases where the layer or film is formed over only a portion of the area.
In the present disclosure, the thickness of a layer or film is determined as the arithmetic mean value of thicknesses measured at five points on the layer or film of interest.
The thickness of the layer or film can be measured using a micrometer or the like. In the present disclosure, when the thickness of the layer or film can be measured directly, it is measured using a micrometer. On the other hand, when the thickness of one layer or the total thickness of multiple layers is measured, it may be measured by observing the cross section of the measurement target using an electron microscope.

In the present disclosure, the term "(meth)acrylic group" means "acrylic group" and "methacrylic group", the term "(meth)acrylate" means "acrylate" and "methacrylate", and the term "(meth)acryloyl" means "acryloyl" and "methacryloyl".
In the present disclosure, when a functional group has a substituent, the number of carbon atoms in the functional group means the total number of carbon atoms including the number of carbon atoms in the substituent.
In the present disclosure, when an embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the size of the members in each drawing is conceptual, and the relative relationship between the sizes of the members is not limited to this.

<Resin composition (first embodiment)>
The first embodiment of the present disclosure is
a polyimide component including at least one of a polyimide precursor and a polyimide resin;
a metal chelating agent,
In the resin composition, the cyclization rate of the polyimide component in a cured state is 80% or less.

In the resin composition of the present embodiment, the cyclization rate of the polyimide component in the cured state is 80% or less. Therefore, compared with a resin composition having a cyclization rate of the polyimide component of more than 80%, shrinkage accompanying the curing reaction of the polyimide component is suppressed. Therefore, for example, when a resin film as a cured product is formed on a substrate, warping of the substrate due to the formation of the resin film is unlikely to occur.
Furthermore, the resin composition of the present embodiment contains a metal chelating agent. It is believed that the metal chelating agent bonds the molecules of the polyimide component to form a three-dimensional crosslinked structure. Therefore, it is believed that the thermal expansion coefficient of the obtained cured product is small even if the cyclization rate of the polyimide component is low.
The components contained in the resin composition and the components that may be contained therein will be described below.

(Polyimide component)
The polyimide component includes at least one of a polyimide precursor and a polyimide resin.
In the present disclosure, the term "polyimide precursor" refers to at least one selected from the group consisting of polyamic acid, polyamic acid ester, polyamic acid salt, and polyamic acid amide.
Polyamic acid esters and polyamic acid amides are compounds in which the hydrogen atoms of at least some of the carboxy groups in a polyamic acid are substituted with monovalent organic groups, and polyamic acid salts are compounds in which at least some of the carboxy groups in a polyamic acid form a salt structure with a basic compound having a pH of over 7.
In the present disclosure, the term "polyimide resin" refers to a resin having an imide skeleton in all or part of the resin skeleton.

The resin composition may contain a polyimide precursor and a polyimide resin as the polyimide component. In this case, the generation of volatile substances due to dehydration cyclization during imide ring formation can be suppressed compared to the case where only a polyimide precursor is contained as the polyimide component. Therefore, the generation of voids in the cured product tends to be suppressed.
The polyimide component is preferably in a state of being dissolved in a solvent.

In the resin composition of this embodiment, the cyclization rate of the polyimide component in the cured state is 80% or less.
From the viewpoint of suppressing shrinkage due to the cyclization reaction of the polyimide precursor, the cyclization rate of the polyimide component in the cured state is preferably 75% or less, more preferably 70% or less, and even more preferably 65% or less.
From the viewpoint of fully exhibiting the properties of the polyimide, the cyclization rate of the polyimide component in the cured state is preferably 30% or more, more preferably 35% or more, and even more preferably 40% or more.

In this disclosure, the cyclization rate of the polyimide component in the cured state is measured by the method described in the Examples.

As a method for making the cyclization rate of the polyimide component in a cured state 80% or less, a method for inducing a crosslinking reaction of the polyimide component can be mentioned.
More specifically, there is a method in which the cyclization of the polyimide component is inhibited by consuming a functional group that contributes to the cyclization (imidization) of the polyimide component in a crosslinking reaction.
Methods for causing a crosslinking reaction of a polyimide precursor include a method using a metal chelating agent or other crosslinking agents, and a method using a thermal radical generator.

(Polyimide precursor)
The polyimide precursor preferably contains a compound having a structural unit represented by the following general formula (1), which tends to give a cured product with high reliability.

The polyimide precursor may be a polyimide precursor having a polymerizable unsaturated bond (hereinafter, may be referred to as an "unsaturated polyimide precursor").
The polymerizable unsaturated bond may be a carbon-carbon double bond.
The unsaturated polyimide precursor may be a compound having a structural unit represented by the following general formula (1) in which at least one of R ⁶ and R ⁷ has a polymerizable unsaturated bond.

In formula (1), X represents a tetravalent organic group, Y represents a divalent organic group, and ^R6 and ^R7 each independently represent a hydrogen atom or a monovalent organic group.
The polyimide precursor may have a plurality of structural units represented by the above general formula (1), and X, Y, ^R6 and ^R7 in the plurality of structural units may be the same or different.
In addition, as long as R ⁶ and R ⁷ are each independently a hydrogen atom or a monovalent organic group, the combination is not particularly limited. For example, at least one of R ⁶ and R ⁷ may be a hydrogen atom and the remaining may be a monovalent organic group described below, or they may be the same or different monovalent organic groups. As described above, when the polyimide precursor has a plurality of structural units represented by the above general formula (1), the combinations of R ⁶ and R ⁷ of each structural unit may be the same or different.

In formula (1), the tetravalent organic group represented by X preferably has 4 to 25 carbon atoms, more preferably 5 to 13 carbon atoms, and even more preferably 6 to 12 carbon atoms.
The tetravalent organic group represented by X may contain an aromatic ring. Examples of the aromatic ring include aromatic hydrocarbon groups (e.g., aromatic rings having 6 to 20 carbon atoms) and aromatic heterocyclic groups (e.g., heterocyclic rings having 5 to 20 atoms). The tetravalent organic group represented by X is preferably an aromatic hydrocarbon group. Examples of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, and a phenanthrene ring.
When the tetravalent organic group represented by X contains an aromatic ring, each aromatic ring may have a substituent or may be unsubstituted. Examples of the substituent of the aromatic ring include an alkyl group, a fluorine atom, a halogenated alkyl group, a hydroxyl group, and an amino group.

When the tetravalent organic group represented by X contains a benzene ring, the tetravalent organic group represented by X preferably contains one to four benzene rings, more preferably contains one to three benzene rings, and even more preferably contains one or two benzene rings.
When the tetravalent organic group represented by X contains two or more benzene rings, the benzene rings may be linked by a single bond, or may be linked by a linking group such as an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R ^A ) ₂ -; each of the two R ^A 's independently represents a hydrogen atom, an alkyl group, or a phenyl group), a siloxane bond (-O-(Si(R ^B ) ₂ -O-) _n ; each of the two R ^B 's independently represents a hydrogen atom, an alkyl group, or a phenyl group, and n represents an integer of 1 or 2 or more), or a composite linking group formed by combining at least two of these linking groups. In addition, the two benzene rings may be linked at two points by at least one of a single bond and a linking group to form a five- or six-membered ring containing a linking group between the two benzene rings.

In formula (1), the --COOR ⁶ group and the --CONH-- group are preferably located at the ortho position relative to each other, and the --COOR ⁷ group and the --CO-- group are preferably located at the ortho position relative to each other.

Specific examples of the tetravalent organic group represented by X include groups represented by the following formulae (A) to (F). Among these, from the viewpoint of obtaining an insulating film excellent in flexibility and further suppressing the occurrence of voids at the bonding interface, a group represented by the following formula (E) is preferred. C in formula (E) is more preferably a group containing an ether bond, and even more preferably an ether bond. Formula (F) below is a structure in which C in formula (E) below is a single bond.
It should be noted that the present disclosure is not limited to the following specific examples.

In formula (D), A and B are each independently a single bond or a divalent group not conjugated with a benzene ring. However, A and B cannot both be single bonds. Examples of the divalent group not conjugated with a benzene ring include a methylene group, a halogenated methylene group, a halogenated methylmethylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R ^A ) ₂ -; each of the two R ^A 's independently represents a hydrogen atom, an alkyl group, or a phenyl group). Among these, A and B are each independently preferably a methylene group, a bis(trifluoromethyl)methylene group, a difluoromethylene group, an ether bond, a sulfide bond, or the like, and more preferably an ether bond.

In formula (E), C represents a single bond, an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a phenylene group, an ester bond (-O-C(=O)-), a silylene bond (-Si(R ^A ) ₂ -; two R ^A 's each independently represent a hydrogen atom, an alkyl group, or a phenyl group), a siloxane bond (-O-(Si(R ^B ) ₂ -O-) _n ; two R ^B 's each independently represent a hydrogen atom, an alkyl group, or a phenyl group, and n is an integer of 1 or 2 or more), or a divalent group combining at least two of these. C is preferably a group containing an ether bond, and is preferably an ether bond.

In formula (1), the divalent organic group represented by Y preferably has 4 to 25 carbon atoms, more preferably 6 to 20 carbon atoms, and even more preferably 12 to 18 carbon atoms.
The skeleton of the divalent organic group represented by Y may be the same as the skeleton of the tetravalent organic group represented by X, and a preferred skeleton of the divalent organic group represented by Y may be the same as the preferred skeleton of the tetravalent organic group represented by X. The skeleton of the divalent organic group represented by Y may be a structure in which two bonding positions of the tetravalent organic group represented by X are substituted with atoms (e.g., hydrogen atoms) or functional groups (e.g., alkyl groups).
The divalent organic group represented by Y may be a divalent aliphatic group or a divalent aromatic group. From the viewpoint of heat resistance, the divalent organic group represented by Y is preferably a divalent aromatic group. Examples of the divalent aromatic group include a divalent aromatic hydrocarbon group (e.g., an aromatic ring having 6 to 20 carbon atoms) and a divalent aromatic heterocyclic group (e.g., a heterocyclic ring having 5 to 20 atoms), and the like, with a divalent aromatic hydrocarbon group being preferred.

Specific examples of the divalent aromatic group represented by Y include groups represented by the following formulae (G) and (H). Among these, from the viewpoint of obtaining a cured product that is excellent in flexibility and in which the occurrence of voids at the bonding interface is further suppressed, the group represented by the following formula (H) is preferred, and among these, in the following formula (H), D is more preferably a group containing a single bond or an ether bond, even more preferably a group containing a single bond or an ether bond, particularly preferably a group containing an ether bond, and extremely preferably an ether bond.

In formulae (G) to (H), R each independently represents an alkyl group, an alkoxy group, a halogenated alkyl group, a phenyl group, or a halogen atom, and n each independently represents an integer of 0 to 4.
In formula (H), D represents a single bond, an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a phenylene group, an ester bond (-O-C(=O)-), a silylene bond (-Si( ^RA ) _2- ; two ^RA 's each independently represent a hydrogen atom, an alkyl group, or a phenyl group), a siloxane bond (-O-(Si( ^RB ) ₂ -O-) _n ; two ^RB 's each independently represent a hydrogen atom, an alkyl group, or a phenyl group, and n represents an integer of 1 or 2 or more), or a divalent group combining at least two of these. D may also be a structure represented by formula (C1) above. Specific examples of D in formula (H) are the same as the specific examples of C in formula (E).
It is preferable that each D in formula (H) independently represents a single bond, an ether bond, a group containing an ether bond and a phenylene group, a group containing an ether bond, a phenylene group and an alkylene group, or the like.

The alkyl group represented by R in formulas (G) to (H) is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms.
Specific examples of the alkyl group represented by R in formulae (G) to (H) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, and a t-butyl group.

The alkoxy group represented by R in formulas (G) to (H) is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably an alkoxy group having 1 or 2 carbon atoms.
Specific examples of the alkoxy group represented by R in formulae (G) to (H) include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, an s-butoxy group, and a t-butoxy group.

The halogenated alkyl group represented by R in Formulae (G) to (H) is preferably a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a halogenated alkyl group having 1 to 3 carbon atoms, and even more preferably a halogenated alkyl group having 1 or 2 carbon atoms.
Specific examples of the halogenated alkyl group represented by R in formulas (G) to (H) include alkyl groups in which at least one hydrogen atom contained in the alkyl group represented by R in formulas (G) to (H) is substituted with a halogen atom such as a fluorine atom or a chlorine atom. Among these, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, etc. are preferred.

In formulas (G) to (H), n is preferably 0 to 2, more preferably 0 or 1, and even more preferably 0.

Specific examples of the divalent aliphatic group represented by Y include linear or branched alkylene groups, cycloalkylene groups, and divalent groups having a polyalkylene oxide structure.

The linear or branched alkylene group represented by Y is preferably an alkylene group having 1 to 20 carbon atoms, more preferably an alkylene group having 1 to 15 carbon atoms, and even more preferably an alkylene group having 1 to 10 carbon atoms.
Specific examples of the alkylene group represented by Y include a tetramethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a 2-methylpentamethylene group, a 2-methylhexamethylene group, a 2-methylheptamethylene group, a 2-methyloctamethylene group, a 2-methylnonamethylene group, and a 2-methyldecamethylene group.

The cycloalkylene group represented by Y is preferably a cycloalkylene group having 3 to 10 carbon atoms, and more preferably a cycloalkylene group having 3 to 6 carbon atoms.
Specific examples of the cycloalkylene group represented by Y include a cyclopropylene group, a cyclohexylene group, and the like.

The unit structure contained in the divalent group having a polyalkylene oxide structure represented by Y is preferably an alkylene oxide structure having 1 to 10 carbon atoms, more preferably an alkylene oxide structure having 1 to 8 carbon atoms, and even more preferably an alkylene oxide structure having 1 to 4 carbon atoms. Of these, the polyalkylene oxide structure is preferably a polyethylene oxide structure or a polypropylene oxide structure. The alkylene group in the alkylene oxide structure may be linear or branched. The unit structure in the polyalkylene oxide structure may be of one type or two or more types.

The divalent organic group represented by Y may be a divalent group having a polysiloxane structure. Examples of the divalent group having a polysiloxane structure represented by Y include divalent groups having a polysiloxane structure in which a silicon atom in the polysiloxane structure is bonded to a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 18 carbon atoms.
Specific examples of the alkyl group having 1 to 20 carbon atoms bonded to a silicon atom in the polysiloxane structure include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-octyl group, a 2-ethylhexyl group, an n-dodecyl group, etc. Among these, a methyl group is preferable.
The aryl group having 6 to 18 carbon atoms bonded to the silicon atom in the polysiloxane structure may be unsubstituted or substituted with a substituent. Specific examples of the substituent when the aryl group has a substituent include a halogen atom, an alkoxy group, and a hydroxy group. Specific examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a naphthyl group, and a benzyl group. Of these, a phenyl group is preferred.
The alkyl group having 1 to 20 carbon atoms or the aryl group having 6 to 18 carbon atoms in the polysiloxane structure may be of one type or of two or more types.
The silicon atom constituting the divalent group having a polysiloxane structure represented by Y may be bonded to the NH group in general formula (1) via an alkylene group such as a methylene group or an ethylene group, or an arylene group such as a phenylene group.

The group represented by formula (G) is preferably a group represented by the following formula (G'), and the group represented by formula (H) is preferably a group represented by the following formula (H'), formula (H'') or formula (H'''). From the viewpoint of having a flexible skeleton and excellent bonding properties, it is more preferably a group represented by the following formula (H') or formula (H'').

In formula (H'"), each R independently represents an alkyl group, an alkoxy group, a halogenated alkyl group, a phenyl group, or a halogen atom. R is preferably an alkyl group, and more preferably a methyl group.

In the general formula (1), the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y is not particularly limited. Examples of the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y include the following.
A combination in which X is a group represented by formula (E) and Y is a group represented by formula (H). A combination in which X is a group represented by formula (F) and Y is a group represented by formula (H). A combination in which X is a group represented by formula (E) and Y is a group represented by formulas (G) and (H). A combination in which X is a group represented by formulas (A) and (E) and Y is a group represented by formula (H). A combination in which X is a group represented by formulas (E) and (F) and Y is a group represented by formula (H). Among the above combinations, the combination in which X is a group represented by formula (E) and Y is a group represented by formula (H) is preferred.

^R6 and ^R7 each independently represent a hydrogen atom or a monovalent organic group which may have an unsaturated double bond.
The monovalent organic group is preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms or an organic group having an unsaturated double bond, more preferably any one of a group represented by the following general formula (2), an ethyl group, an isobutyl group, or a t-butyl group, and further preferably contains an aliphatic hydrocarbon group having 1 or 2 carbon atoms or a group represented by the following general formula (2). In this case, at least one of R ⁶ and R ⁷ is a group represented by general formula (2).
When the monovalent organic group contains an organic group having an unsaturated double bond, preferably a group represented by the following general formula (2), the i-ray transmittance is high, and a good cured product tends to be formed even when cured at a low temperature of 400° C. or less. In addition, when the monovalent organic group contains an organic group having an unsaturated double bond, preferably a group represented by the following general formula (2), at least a part of the unsaturated double bond portion is eliminated by the compound (C).

Specific examples of aliphatic hydrocarbon groups having 1 to 4 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups, with ethyl, isobutyl, and t-butyl groups being preferred.

In formula (2), R ⁸ to R ¹⁰ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and R ^x represents a divalent linking group.

The carbon number of the aliphatic hydrocarbon group represented by R ⁸ to R ¹⁰ in general formula (2) is 1 to 3, and preferably 1 or 2. Specific examples of the aliphatic hydrocarbon group represented by R ⁸ to R ¹⁰ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc., and a methyl group is preferred.

As a combination of R ⁸ to R ¹⁰ in the general formula (2), a combination in which R ⁸ and R ⁹ are hydrogen atoms and R ¹⁰ is a hydrogen atom or a methyl group is preferred.

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

In general formula (1), it is preferable that at least one of ^R6 and ^R7 is a group represented by general formula (2), and it is more preferable that both of ^R6 and ^R7 are groups represented by general formula (2).

When the polyimide precursor contains a compound having a structural unit represented by the above-mentioned general formula (1), the ratio of ^R6 and ^R7 , which are groups represented by general formula (2), to the sum of ^R6 and ^R7 of all structural units contained in the compound is preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. There is no particular upper limit.
It may be 100 mol %.
The above ratio may be 0 mol % or more and less than 60 mol %.

The group represented by general formula (2) is preferably a group represented by the following general formula (2'):

In formula (2′), R ⁸ to R ¹⁰ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms; q represents an integer of 1 to 10.

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

The content of the structural unit represented by general formula (1) contained in the compound having the structural unit represented by general formula (1) is preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more, based on the total structural units. The upper limit of the aforementioned content is not particularly limited, and may be 100 mol%.

The polyimide precursor may be synthesized using a tetracarboxylic dianhydride and a diamine compound, in which case, in general formula (1), X corresponds to a residue derived from the tetracarboxylic dianhydride, and Y corresponds to a residue derived from the diamine compound.
The polyimide precursor may be synthesized by using a tetracarboxylic acid instead of a tetracarboxylic dianhydride.

Specific examples of tetracarboxylic dianhydrides include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, and 1,4,5,8-naphthalenetetracarboxylic dianhydride. dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, m-terphenyl-3,3',4,4'-tetracarboxylic dianhydride, p-terphenyl-3,3',4,4'-tetracarboxylic dianhydride, 1,1,4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 4,4'-oxydiphthalic anhydride, 1,3,3,3-hexafluoro-2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2- Bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis{4'-(2,3-dicarboxyphenoxy)phenyl}propane dianhydride, 2,2-bis{4'-(3,4-dicarboxyphenoxy)phenyl}propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis{4'-(2,3-dicarboxyphenoxy)phenyl}propane dianhydride 1,1,1,3,3,3-hexafluoro-2,2-bis{4'-(3,4-dicarboxyphenoxy)phenyl}propane dianhydride, 4,4'-oxydiphthalic dianhydride, 4,4'-sulfonyldiphthalic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, cyclopentanone bisspironorbornane tetracarboxylic acid dianhydride, 2,2-bis{4-(4'-phenoxy)phenyl}propane tetracarboxylic acid dianhydride, and the like.
Among these, at least one selected from the group consisting of 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-oxydiphthalic anhydride, and 3,3',4,4'-biphenyl tetracarboxylic dianhydride is preferable, at least one selected from the group consisting of pyromellitic dianhydride and 4,4'-oxydiphthalic anhydride is more preferable, and from the viewpoint of bonding at lower temperatures, it is even more preferable to include 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride.
The tetracarboxylic dianhydrides may be used alone or in combination of two or more kinds.

Specific examples of the diamine compound include 2,2'-dimethylbiphenyl-4,4'-diamine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 1,5-diaminonaphthalene, benzidine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 4, 4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,4'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 2,4'-diaminodiphenyl sulfide, 2,2'-diaminodiphenyl sulfide, o-tolidine, o-tolidine sulfone, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2,6-diisopropylaniline), 2 ,4-diaminomesitylene, 1,5-diaminonaphthalene, 4,4'-benzophenonediamine, bis-{4-(4'-aminophenoxy)phenyl}sulfone, 2,2-bis{4-(4'-aminophenoxy)phenyl}propane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis{4-(3'-aminophenoxy)phenyl}sulfone, 2,2-bis(4-aminophenyl)propane, 9,9-bis(4-aminophenyl)fluorene, 1,3-bis(3-aminophenoxy)benzene, 1, Examples of the diamine compound include 4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 2-methyl-1,5-diaminopentane, 2-methyl-1,6-diaminohexane, 2-methyl-1,7-diaminoheptane, 2-methyl-1,8-diaminooctane, 2-methyl-1,9-diaminononane, 2-methyl-1,10-diaminodecane, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, and diaminopolysiloxane. As the diamine compound, 2,2'-dimethylbiphenyl-4,4'-diamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, and 1,3-bis(3-aminophenoxy)benzene are preferred.
Among these, at least one selected from the group consisting of 2,2'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenyl ether, m-phenylenediamine, and 1,3-bis(3-aminophenoxy)benzene is more preferable, and from the viewpoint of having a flexible skeleton and excellent adhesiveness, at least one selected from the group consisting of 4,4'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, and 2,2-bis{4-(4'-aminophenoxy)phenyl}propane is even more preferable.
The diamine compounds may be used alone or in combination of two or more kinds.

A compound having a structural unit represented by general formula (1) in which at least one of ^R6 and ^R7 in general formula (1) is a monovalent organic group can be obtained, for example, by the following method (a) or (b).
(a) A tetracarboxylic dianhydride (preferably a tetracarboxylic dianhydride represented by the following general formula (8)) is reacted with a compound represented by R-OH in an organic solvent to form a diester derivative, and then the diester derivative is subjected to a condensation reaction with a diamine compound represented by H ₂ N-Y-NH ₂ .
(b) A tetracarboxylic dianhydride is reacted with a diamine compound represented by H ₂ N-Y-NH ₂ in an organic solvent to obtain a polyamic acid solution, and a compound represented by R-OH is added to the polyamic acid solution and reacted in the organic solvent to introduce an ester group.

Since at least one of R ⁶ and R ⁷ in the general formula (1) has a polymerizable unsaturated bond, at least one of R—OH in which R has a polymerizable unsaturated bond is used.

Here, Y in the diamine compound represented by H ₂ N-Y-NH ₂ is the same as Y in general formula (1), and specific examples and preferred examples are also the same. Furthermore, R in the compound represented by R-OH represents a monovalent organic group, and specific examples and preferred examples are the same as R ⁶ and R ⁷ in general formula (1).
The tetracarboxylic dianhydride represented by the general formula (8), the diamine compound represented by H ₂ N-Y-NH ₂ , and the compound represented by R-OH may each be used alone or in combination of two or more.

Examples of the organic solvent include N-methyl-2-pyrrolidone, γ-butyrolactone, dimethoxyimidazolidinone, and 3-methoxy-N,N-dimethylpropanamide, and among these, 3-methoxy-N,N-dimethylpropanamide is preferred.
An unsaturated polyimide precursor may be synthesized by reacting a polyamic acid solution with a dehydration condensation agent together with the compound represented by R-OH. The dehydration condensation agent preferably contains at least one selected from the group consisting of trifluoroacetic anhydride, N,N'-dicyclohexylcarbodiimide (DCC) and 1,3-diisopropylcarbodiimide (DIC).

The above-mentioned compound contained in the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH to form a diester derivative, then reacting it with a chlorinating agent such as thionyl chloride to convert it into an acid chloride, and then reacting a diamine compound represented by H ₂ N-Y-NH ₂ with the acid chloride.
The above-mentioned compound contained in the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH to form a diester derivative, and then reacting the diamine compound represented by H ₂ N-Y-NH ₂ with the diester derivative in the presence of a carbodiimide compound.

The above-mentioned compound contained in the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a diamine compound represented by H ₂ N-Y-NH ₂ to form a polyamic acid, then isoimidizing the polyamic acid in the presence of a dehydrating condensing agent such as trifluoroacetic anhydride, and then reacting the compound represented by R-OH. Alternatively, a compound represented by R-OH may be reacted in advance with a part of the tetracarboxylic dianhydride to react the partially esterified tetracarboxylic dianhydride with the diamine compound represented by H ₂ N-Y-NH ₂ .

In general formula (8), X is the same as X in general formula (1), and specific examples and preferred examples are also the same.

The compound represented by R-OH used in the synthesis of the above-mentioned compound contained in the unsaturated polyimide precursor may be a compound in which a hydroxy group is bonded to R ^x of the group represented by general formula (2), a compound in which a hydroxy group is bonded to the terminal methylene group of the group represented by general formula (2'), etc. Specific examples of the compound represented by R-OH include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, etc., among which 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate are preferred.

There is no particular restriction on the molecular weight of the polyimide precursor, and for example, the weight average molecular weight is preferably 10,000 to 200,000, more preferably 10,000 to 100,000, and even more preferably 10,000 to 50,000.
The weight average molecular weight of the polyimide precursor can be measured, for example, by gel permeation chromatography, and can be calculated using a standard polystyrene calibration curve.

The resin composition of the present disclosure may further include a dicarboxylic acid. The polyimide precursor contained in the resin composition may have a structure in which a part of the amino group in the polyimide precursor reacts with a carboxy group in the dicarboxylic acid. For example, when synthesizing the polyimide precursor, a part of the amino group of the diamine compound may react with a carboxy group of the dicarboxylic acid.
The dicarboxylic acid may be a dicarboxylic acid having a (meth)acrylic group, for example, a dicarboxylic acid represented by the following formula: In this case, when synthesizing the polyimide precursor, a methacryl group derived from the dicarboxylic acid can be introduced into the polyimide precursor by reacting a part of the amino group of the diamine compound with a carboxy group of the dicarboxylic acid.

(Polyimide resin)
The polyimide resin preferably contains a compound having a structural unit represented by the following general formula (X): This tends to give a cured product with high reliability.

In the general formula (X), X represents a tetravalent organic group, and Y represents a divalent organic group. Preferred examples of the substituents X and Y in the general formula (X) are the same as the preferred examples of the substituents X and Y in the general formula (1) described above.

When the resin composition contains a polyimide precursor and a polyimide resin, the ratio of the polyimide resin to the total of the polyimide precursor and the polyimide resin may be 15% by mass to 50% by mass, or 10% by mass to 20% by mass.

The resin composition may contain other resins that are not polyimide components as resin components. From the viewpoint of heat resistance, examples of other resins include novolac resins, acrylic resins, polyether nitrile resins, polyether sulfone resins, epoxy resins, polyethylene terephthalate resins, polyethylene naphthalate resins, polyvinyl chloride resins, etc. The other resins may be used alone or in combination of two or more.

In the resin composition, the content of the polyimide component relative to the total amount of resin components is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass.

(Metal Chelating Agent)
Examples of the metal chelating agent contained in the resin composition include a titanium chelating agent, a zirconium chelating agent, and an aluminum chelating agent. The metal chelating agents may be used alone or in combination of two or more.

Specific examples of the titanium chelating agent include titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetoacetate, titanium dodecylbenzenesulfonate compounds, titanium phosphate complexes, titanium octylene glycolate, and titanium ethylacetoacetate.
Specific examples of the zirconium chelating agent include zirconium tetraacetylacetonate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium tetraacetylacetonate, and zirconium ethylacetoacetate.
Specific examples of the aluminum chelating agent include aluminum trisacetylacetonate, aluminum bisethylacetoacetate monoacetylacetonate, and aluminum trisethylacetoacetate.

The content of the metal chelating agent in the resin composition is preferably 0.1 parts by mass or more per 100 parts by mass of the polyimide component, more preferably 0.2 parts by mass or more, and even more preferably 0.5 parts by mass or more.

The content of the metal chelating agent in the resin composition is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of the polyimide component.

<Other ingredients>
The resin composition may further contain components other than the polyimide component and the metal chelating agent. For example, the resin composition may contain a photopolymerization initiator, a stabilizer, a crosslinking agent, a sensitizer, an ultraviolet absorber, a rust inhibitor, a thermal radical generator, an antioxidant, a solvent, etc., which will be described later.

(Photopolymerization initiator)
The resin composition may contain a photopolymerization initiator. The photopolymerization initiator may be used alone or in combination of two or more.
From the viewpoints of achieving excellent exposure sensitivity and suppressing the occurrence of voids during bonding, it is preferable that the photopolymerization initiator contains an oxime-based photopolymerization initiator.
Specific examples of oxime-based photopolymerization initiators include 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, and 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime. , 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, 1-[4-(phenylthio)phenyl]octane-1,2-dione=2-(O-benzoyloxime), O-acetyl-1-[6-(2-methylbenzoyl)-9-ethyl-9H-carbazol-3-yl]ethanone oxime, 1-[4-(4-hydroxyethyloxy-phenylthio)phenyl]-1,2-propanedione-2-(O-acetyloxime), and the like.

When the resin composition contains a photopolymerization initiator, the total amount of the photopolymerization initiator is preferably 0.1 parts by mass to 20 parts by mass, more preferably 1 part by mass to 20 parts by mass, and even more preferably 5 parts by mass to 20 parts by mass, per 100 parts by mass of the polyimide component.

(Stabilizer)
The resin composition may contain a stabilizer. The stabilizer may be used alone or in combination of two or more.

Stabilizers include p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, ortho-dinitrobenzene, para-dinitrobenzene, meta-dinitrobenzene, phenanthraquinone, N-phenyl-2-naphthylamine, cupferron, 2,5-toluquinone, tannic acid, parabenzylaminophenol, nitrosamines, azo compounds, hindered amine compounds, hindered phenol compounds, etc.

If the resin composition contains a stabilizer, the content of the stabilizer is preferably 0.05 parts by mass to 1.0 parts by mass, and more preferably 0.1 parts by mass to 0.8 parts by mass, per 100 parts by mass of the polyimide component.

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

The crosslinking agent may be a compound having two or more groups (hereinafter also referred to as functional groups) that contain a polymerizable unsaturated bond. From the viewpoint of polymerization reactivity, the functional group is preferably a (meth)acryloyl group or a vinyl group, and more preferably a (meth)acryloyl group.

Bifunctional crosslinking agents include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, trimethylolpropane diacrylate, tricyclodecane dimethanol diacrylate, tricyclodecane dimethanol dimethacrylate, etc.

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

Examples of tetrafunctional or higher crosslinking agents include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tetramethylolmethane tetraacrylate, tetramethylolmethane tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tetrakisacrylate methanetetrayltetrakis (methyleneoxyethylene), etc.

When the resin composition contains a crosslinking agent, the content of the crosslinking agent is preferably 1 to 50 parts by mass, more preferably 3 to 50 parts by mass, and even more preferably 5 to 40 parts by mass, per 100 parts by mass of the polyimide component.

(Sensitizer)
The resin composition may contain a sensitizer. The sensitizer may be used alone or in combination of two or more kinds.
Specific examples of the sensitizer include benzophenone, N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, 4,4'-bis(diethylamino)benzophenone, o-benzoylmethylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and benzophenone derivatives such as fluorenone.

If the resin composition contains a sensitizer, the content of the sensitizer is preferably 0.01 to 3 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the polyimide component.

(Ultraviolet absorber)
The resin composition may contain an ultraviolet absorbing agent. When the resin composition contains an ultraviolet absorbing agent, crosslinking of the unexposed area due to diffuse reflection during exposure tends to be suppressed.

Examples of ultraviolet absorbents include benzotriazole-based compounds, salicylic acid ester-based compounds, benzophenone-based compounds, diphenylacrylate-based compounds, cyanoacrylate-based compounds, diphenylcyanoacrylate-based compounds, benzothiazole-based compounds, azobenzene-based compounds, polyphenol-based compounds, nickel complex salt-based compounds, etc. The ultraviolet absorbents may be used alone or in combination of two or more types.

If the resin composition contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.05 parts by mass to 5 parts by mass, more preferably 0.1 parts by mass to 3 parts by mass, and even more preferably 0.2 parts by mass to 2 parts by mass, per 100 parts by mass of the polyimide component.

(Rust inhibitor)
The resin composition may contain a rust inhibitor from the viewpoint of suppressing corrosion of metals such as copper and copper alloys, and from the viewpoint of suppressing discoloration of the metals. Examples of the rust inhibitor include azole compounds and purine derivatives. The rust inhibitor may be used alone or in combination of two or more kinds.

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

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

If the resin composition contains a rust inhibitor, the content of the rust inhibitor is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the polyimide component.

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

Specific examples of thermal radical generators include ketone peroxides such as methyl ethyl ketone peroxide, peroxyketals such as 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, and 1,1-di(t-butylperoxy)cyclohexane, hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, and diisopropylbenzene hydroperoxide, and dihydroperoxides such as dicumyl peroxide and di-t-butyl peroxide. Examples of the thermal polymerization initiator include alkyl peroxides, diacyl peroxides such as dilauroyl peroxide and dibenzoyl peroxide, peroxydicarbonates such as di(4-t-butylcyclohexyl)peroxydicarbonate and di(2-ethylhexyl)peroxydicarbonate, peroxy esters such as t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxybenzoate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, and bis(1-phenyl-1-methylethyl)peroxide. One type of thermal polymerization initiator may be used alone, or two or more types may be used in combination.

When the resin composition contains a thermal radical generator, the content of the thermal radical generator is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of the polyimide component.

(Antioxidants)
The resin composition may contain an antioxidant. The antioxidant may be used alone or in combination of two or more kinds.

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

When the resin composition contains an antioxidant, the content of the antioxidant is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the polyimide component.

(solvent)
The resin composition may contain a solvent. The solvent may be used alone or in combination of two or more.
Specific examples of the solvent include ketones such as cyclohexanone, cyclopentanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, and γ-butyrolactone; and sulfoxides such as dimethyl sulfoxide.

In one embodiment, the resin composition preferably contains at least one solvent selected from gamma-butyrolactone, ethyl lactate, and dimethyl sulfoxide, more preferably contains at least two solvents, and even more preferably contains all three solvents.

If the resin composition contains a solvent, the content of the solvent is preferably 10 parts by mass to 10,000 parts by mass, more preferably 50 parts by mass to 1,000 parts by mass, and even more preferably 100 parts by mass to 500 parts by mass, per 100 parts by mass of the polyimide component.

<Resin composition (second embodiment)>
The second embodiment of the present disclosure is
a polyimide component including at least one of a polyimide precursor and a polyimide resin;
A metal chelating agent;
and a thermal radical generator.

The resin composition of the present embodiment contains a thermal radical generator. Therefore, the cyclization rate of the polyimide component in the cured state of the resin composition is lower than the cyclization rate of the polyimide component in the cured state of a resin composition that does not contain a thermal radical generator. Therefore, shrinkage accompanying the curing of the polyimide component is suppressed compared to the case of curing a resin composition that does not contain a thermal radical generator. Therefore, for example, when a resin film as a cured product is formed on a substrate, warping of the substrate due to the formation of the resin film is unlikely to occur.
Furthermore, the resin composition of the present embodiment contains a metal chelating agent. It is believed that the metal chelating agent bonds the molecules of the polyimide component to form a three-dimensional crosslinked structure. Therefore, it is believed that even if the cyclization rate of the polyimide component is low, the obtained cured product exhibits a low thermal expansion coefficient.

The thermal radical generator contained in the resin composition may be, for example, one or more types selected from the thermal radical generators described above.
The content of the thermal radical generator in the resin composition is preferably 0.1 parts by mass to 15 parts by mass, more preferably 1 part by mass to 10 parts by mass, and even more preferably 1 part by mass to 5 parts by mass, relative to 100 parts by mass of the polyimide component.

The details and preferred aspects of the polyimide component, metal chelating agent, thermal radical generator, and other components contained in the resin composition of the second embodiment are the same as the details and preferred aspects of the polyimide component, metal chelating agent, thermal radical generator, and other components contained in the resin composition of the first embodiment.

[Main component content]
In the resin compositions of the first and second embodiments described above, the total content of the polyimide component, the metal chelating agent, the thermal radical generator, the photopolymerization initiator, the stabilizer, and the crosslinking agent may be 80% by mass or more, 90% by mass or more, or 95% by mass or more.

<Cured Product>
The cured product of the present disclosure can be obtained by curing the resin composition of the present disclosure.
When the resin composition has photosensitivity, the cured product of the present disclosure can be obtained by exposing the resin composition to light.
Examples of methods for imparting photosensitivity to a resin composition include a method of introducing a polymerizable unsaturated bond into a polyimide component contained in the polymerizable composition, and a method of adding a component having photocurability to the polymerizable composition.
The cured product of the present disclosure can be suitably used as a patterned cured product.
The average thickness of the cured product is preferably 5 μm to 20 μm.

<Method of producing the cured product>
The method for producing the cured product according to the present disclosure includes:
forming a layer of the resin composition of the present disclosure on a substrate;
and curing the layer of resin composition.

The method for forming a layer of the resin composition (hereinafter also referred to as the resin composition layer) on the substrate is not particularly limited. For example, the resin composition may be applied to the substrate using a spinner or the like, and then dried using a hot plate, oven, or the like.

Examples of the substrate include semiconductor substrates such as glass substrates and Si substrates (silicon wafers), metal oxide insulator substrates such as _TiO2 substrates and _SiO2 substrates, silicon nitride substrates, copper substrates, copper alloy substrates, etc. The surface of the substrate on which the resin composition layer is formed may be made of two or more different materials.

The average thickness of the resin composition layer formed on the substrate is preferably 5 μm to 100 μm, more preferably 6 μm to 50 μm, and even more preferably 7 μm to 30 μm.

The method for curing the resin composition layer formed on the substrate is not particularly limited.
When the resin composition has photosensitivity, the resin composition layer may be cured by exposure to light (and, if necessary, heat treatment after exposure).
The exposure may be carried out by pattern exposure (a method of carrying out exposure in a pattern consisting of exposed and unexposed areas).
The pattern exposure is performed by exposing a predetermined pattern through a photomask, for example.
Examples of actinic rays used for exposure include ultraviolet rays such as i-rays, visible light, and radiation, with i-rays being preferred.
As the exposure device, a parallel exposure device, an aligner, a projection exposure device, a stepper, a scanner exposure device, or the like can be used.

The exposed resin composition layer is developed to obtain a patterned resin film (patterned resin film). In general, when a negative photosensitive resin composition is used, the unexposed areas are removed with a developer.
As the developer, a good solvent for the photosensitive resin film can be used alone, or a suitable mixture of a good solvent and a poor solvent can be used. After development, the patterned resin film may be washed with a rinse liquid.
Examples of the good solvent include N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, α-acetyl-γ-butyrolactone, cyclopentanone, and cyclohexanone.
Examples of the poor solvent include toluene, xylene, methanol, ethanol, isopropanol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and water.

The developed resin film may be subjected to a heat treatment (post-baking) to obtain a patterned cured product.
By carrying out the heat treatment, for example, the polyimide precursor contained in the resin film after development undergoes a dehydration ring-closing reaction to become a polyimide resin.

The temperature of the heat treatment is preferably 250°C or lower, more preferably 120°C to 250°C, and even more preferably 160°C to 200°C.
By keeping the heat treatment temperature within the above range, damage to the substrate or device can be minimized, devices can be produced with a high yield, and energy savings can be achieved in the process.

The heat treatment time is preferably 5 hours or less, and more preferably 30 minutes to 3 hours.
The heat treatment may be performed in air or in an inert atmosphere such as nitrogen, but is preferably performed in a nitrogen atmosphere from the viewpoint of preventing oxidation of the patterned resin film.

Equipment used for heat treatment includes quartz tube furnaces, hot plates, rapid thermal annealing, vertical diffusion furnaces, infrared curing furnaces, electron beam curing furnaces, microwave curing furnaces, etc.

The cured product of the present disclosure can be used, for example, as a resin film.
Specific examples of the resin film include a passivation film, a buffer coat film, an interlayer insulating film, a cover coat film, and a surface protection film.

<Electronic Components>
The electronic component of the present disclosure includes the cured product of the present disclosure described above.
The electronic component includes, for example, the cured product of the present disclosure as a resin film.
Specific examples of electronic components include semiconductor devices, multilayer wiring boards, various electronic devices, and stacked devices (such as multi-die fan-out wafer level packages).
In the electronic component, the member in contact with the cured product of the present disclosure may be made of two or more materials (for example, silicon and metal).

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

Next, a photosensitive resin layer 5, such as a chlorinated rubber or phenol novolac type, is formed on the interlayer insulating film 4, and windows 6A are provided using known photoetching techniques to expose predetermined portions of the interlayer insulating film 4.

The interlayer insulating film 4 from which the window 6A is exposed is selectively etched to provide a window 6B.
Next, the photosensitive resin layer 5 is removed using an etching solution that will corrode the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed through the windows 6B.

Further, a second conductor layer 7 is formed by using a known photolithography technique, and is electrically connected to the first conductor layer 3 .
When forming a multi-layer wiring structure having three or more layers, the above-mentioned steps can be repeated to form each layer.

Next, the resin composition of the present disclosure is used to open windows 6C by pattern exposure to form a surface protective film 8. The surface protective film 8 protects the second conductor layer 7 from external stress, α-rays, and the like, and the resulting semiconductor device has excellent reliability.
In the above example, the interlayer insulating film 4 can also be formed using the resin composition of the present disclosure.

The present disclosure will be explained in more detail below based on examples and comparative examples. Note that the present disclosure is not limited to the following examples.

(Synthesis of polyimide precursor)
380 g of N-methyl-2-pyrrolidone (NMP, Mitsubishi Chemical Corporation) was placed in a 2 L separable flask, and 47.08 g (152 mmol) of 4,4'-oxydiphthalic anhydride (ODPA, Manac Corporation) was added and dissolved while stirring. Furthermore, 0.24 g (2.1 mmol) of DABCO (1,4-diazabicyclo[2.2.2]octane, Fujifilm Wako Pure Chemical Industries, Ltd.) was added and dissolved, and 5.54 g (42.6 mmol) of 2-hydroxyethyl methacrylate (HEMA, Fujifilm Wako Pure Chemical Industries, Ltd.) was added. This mixture was stirred at 30°C for 1 hour to obtain a reaction solution.

Separately, 27.4 g (129 mmol) of 2,2'-dimethylbiphenyl-4,4'-diamine (DMAP, Wakayama Seika Kogyo Co., Ltd.) was dissolved in 145 g of NMP to prepare a DMAP solution.
The reaction solution was stirred at 35°C while the DMAP solution was dropped, and then stirred at 30°C for 3 hours. Next, 59.7g (284mmol) of TFAA (trifluoroacetic anhydride, Fujifilm Wako Pure Chemical Industries, Ltd.) was dropped at 30°C. After stirring at 45°C for 2 hours, 0.08g (0.74mmol) of BQ (benzoquinone, Fujifilm Wako Pure Chemical Industries, Ltd.) was added, and 40.4g (310mmol) of HEMA was dropped. After stirring for 15 hours, the mixture was cooled to room temperature. The reaction solution was poured into purified water, and the precipitate was collected. The collected precipitate was washed with purified water, and then dried under reduced pressure to obtain a polyimide precursor having a polymerizable unsaturated bond.
The weight average molecular weight (Mw) of the obtained polyimide precursor was 22,100.

The weight average molecular weight of the polyimide precursor was calculated from a calibration curve of TSKgel standard polystyrene (Tosoh Corporation) by gel permeation chromatography (GPC). The apparatus and conditions are shown below. The measurement sample was prepared by dissolving 2 mg of the sample in 1 mL of eluent (tetrahydrofuran (THF)/dimethylformamide (DMF) = 1/1 (v/v)) and then filtering through a PTFE membrane filter with a pore size of 1 μm.
Equipment: Shimadzu Corporation, Prominence
Column: Resonac Co., Ltd., Gelpak GL S300MDT-5
Eluent: THF/DMF=1/1 (v/v), lithium bromide 0.03 mol/L, phosphoric acid 0.06 mol/L
・Flow rate: 1.0mL/min
・Measurement wavelength: 270nm
Injection volume: 10 μL

(Preparation of Resin Composition)
Resin compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared using the components and amounts shown in Table 1. Specifically, a mixture of the components was kneaded overnight at room temperature (25°C) in a general solvent-resistant container, and then pressure filtered using a filter with 0.2 µm pores to obtain a resin composition.

The amount of each component in Table 1 is expressed in parts by mass, and the numbers in parentheses in the solvent column indicate the content (mass%) in the solvent.
The components in Table 1 are as follows.
GBL: γ-butyrolactone EL: Ethyl lactate DMSO: Dimethyl sulfoxide Crosslinker 1: Tricyclodecane dimethanol diacrylate (bifunctional)
Crosslinking agent 2: Tris-(2-acryloxyethyl)isocyanurate (trifunctional)
Crosslinker 3: Triethylene glycol dimethacrylate (bifunctional)
Photopolymerization initiator: 1-[4-(phenylthio)phenyl]octane-1,2-dione = 2-(O-benzoyloxime (Irgacure OXE1, BASF)
Metal chelating agent 1: Titanium diisopropoxybis(ethyl acetoacetate) (Matsumoto Fine Chemical Co., Ltd.)
Metal chelating agent 2: Zirconium tetraacetylacetonate (Matsumoto Fine Chemical Co., Ltd.)
Thermal radical generator: dicumyl peroxide (NOF Corporation)
Cyclization promoter: N-phenyldiethanolamine (FUJIFILM Wako Pure Chemical Industries, Ltd.)

(Measurement of Cyclization Rate)
The resin composition was spin-coated on a silicon substrate and dried at 120° C. for 3 minutes to form a coating film (A) having a thickness of about 7 μm after drying. The entire surface of this coating film was irradiated with UV light at 800 mJ/cm ² using an exposure device (Mask Aligner MA8, manufactured by SUSS MicroTec Co., Ltd.).
The exposed coating film (A) was heated at 170° C. for 3 hours in a nitrogen atmosphere to obtain a cured film (B).
The exposed coating film (A) was heated at 375° C. for 1 hour in a nitrogen atmosphere to obtain a cured film (C).
The infrared absorption spectra of the coating film (A), the cured film (B) and the cured film (C) were measured to determine the absorbance of the peak due to the C=O stretching vibration of the imide bond at around 1780 cm ^-1 and the absorbance of the peak due to the C-H deformation vibration of the aromatic ring at around 964 cm ^- 1. An FTS 3000MX (manufactured by Digilab Corporation) was used to measure the infrared absorption spectra.

The cyclization rate of the coating film (A) was taken as 0% and the cyclization rate of the cured film (C) as 100%, and the cyclization rate of the cured film (B) was calculated from the following formula.
R ₀ =absorbance at 1780 cm ^-1 of coating film (A)/absorbance at 964 cm ^-1 R _T =absorbance at 1780 cm ^-1 of cured film (B)/absorbance at 964 cm ^-1 R ₁₀₀ =absorbance at 1780 cm ^-1 of cured film (C)/absorbance at 964 cm ^-1 Cyclization rate=100×(R ₀ -R _T )/(R ₀ -R ₁₀₀ )

(Measurement of Tg and CTE)
The resin composition was spin-coated on a silicon substrate and dried at 120° C. for 3 minutes to form a coating film having a thickness of about 12 μm after drying. The entire surface of the coating film was irradiated with UV light at 800 mJ/cm ² using an exposure device (Mask Aligner MA8, manufactured by SUSS MicroTec Co., Ltd.). The exposed coating film was heated at 170° C. for 3 hours in a nitrogen atmosphere to obtain a cured film.
The cured film after the heat treatment was immersed in an aqueous hydrofluoric acid solution and peeled off from the silicon substrate. The Tg and CTE of the peeled off cured film were measured using a thermomechanical analyzer TMA7100 (manufactured by Hitachi High-Tech Science). Specifically, the cured film was cut into a size of 2 mm wide and 30 mm long, attached to the device so that the measurement sample amount was 15 mm, and heated to 400°C with a load of 98 mN and a heating rate of 5°C/min. Tg is the glass transition temperature. CTE is the displacement of the length of the cured film when heated in the range of 100°C to 150°C.

As shown in Table 1, the resin compositions of Examples 1 to 4, in which the cyclization rate of the polyimide component was 80% or less (or which contained a thermal radical generator) and which contained a metal chelating agent, had high glass transition temperatures and small thermal expansion coefficients of the cured products.
The resin composition of Comparative Example 1, which does not contain a metal chelating agent, has a thermal expansion coefficient of a cured product that is greater than those of the Examples.
The resin composition of Comparative Example 2, in which the cyclization rate of the polyimide component is greater than 80% (or which does not contain a thermal radical generator), has a higher thermal expansion coefficient of the cured product than those of the Examples.

Claims (7)

a polyimide component including at least one of a polyimide precursor and a polyimide resin;
a metal chelating agent,
A resin composition, wherein the cyclization rate of the polyimide component in a cured state is 80% or less. a polyimide component including at least one of a polyimide precursor and a polyimide resin;
A metal chelating agent;
A resin composition comprising: The resin composition according to claim 1 or claim 2, further comprising a photopolymerization initiator. The resin composition according to claim 1 or 2, wherein the metal chelating agent includes a titanium chelating agent or a zirconium chelating agent. A cured product of the resin composition according to claim 1 or claim 2. A method for producing a cured product comprising the steps of forming a layer of the resin composition according to claim 1 or 2 on a substrate and curing the layer of the resin composition. An electronic component comprising a cured product of the resin composition according to claim 1 or 2.