WO2025099883A1 - Photosensitive resin composition, method for producing patterned cured product, patterned cured product, and electronic component - Google Patents

Abstract

A photosensitive resin composition containing a polyimide precursor having a polymerizable unsaturated bond, and a solvent, wherein the solvent contains N,N'-dimethylpropionamide.

Description

Photosensitive resin composition, method for producing patterned cured product, patterned cured product, and electronic component

The present disclosure relates to a photosensitive resin composition, a method for producing a patterned cured product, a patterned 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

It is desirable to improve the storage stability at room temperature of photosensitive resin compositions containing polyimide resins. In addition, in consideration of the impact on the environment and human body, it is desirable to reduce the amount of solvent used in photosensitive resin compositions.

In view of the above-mentioned conventional circumstances, one embodiment of the present disclosure aims to provide a photosensitive resin composition that has excellent storage stability at room temperature and can reduce the amount of solvent used, as well as a patterned cured product using this photosensitive resin composition, a method for producing the patterned cured product, and an electronic component.

Specific means for achieving the above object are as follows.
<1> A method for producing a polyimide composition comprising: a polyimide precursor having a polymerizable unsaturated bond; and a solvent;
The photosensitive resin composition, wherein the solvent comprises N,N'-dimethylpropionamide.
<2> The photosensitive resin composition according to <1>, wherein the polyimide precursor having a polymerizable unsaturated bond has a structural unit represented by the following general formula (1):

(In general formula (1), X represents a tetravalent organic group, and Y represents a divalent organic group. ^R6 and ^R7 each independently represent a hydrogen atom or a monovalent organic group, and at least one of ^R6 and ^R7 has a polymerizable unsaturated bond.)
<3> The photosensitive resin composition according to <1> or <2>, further comprising a photopolymerization initiator.
<4> The photosensitive resin composition according to any one of <1> to <3>, wherein the proportion of N,N'-dimethylpropionamide in the solvent is 50 mass% or more.
<5> A step of applying the photosensitive resin composition according to any one of <1> to <4> onto a substrate and drying the composition to form a photosensitive resin film;
a step of exposing the photosensitive resin film to a pattern to obtain a resin film;
developing the resin film after the patterned exposure with a developer to obtain a patterned resin film;
and heat-treating the patterned resin film.
<6> A patterned cured product obtained by curing the photosensitive resin composition according to any one of <1> to <4>.
<7> The patterned cured product according to <6>, which is used as an interlayer insulating film, a cover coat layer or a surface protective film.
<8> An electronic component comprising the patterned cured product according to <6>.

According to one embodiment of the present disclosure, there is provided a photosensitive resin composition that has excellent storage stability at room temperature and can reduce the amount of solvent used, as well as a patterned cured product using this photosensitive resin composition, a method for producing the patterned cured product, and an electronic component.

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

Below, the form for implementing this disclosure will be described in detail. However, this disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless specifically stated otherwise. The same applies to numerical values and their ranges, and they do not limit this 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, a "(meth)acryloyl group" means at least one of an acryloyl group and a methacryloyl group, and a "(meth)acryloyloxy group" means at least one of an acryloyloxy group and a methacryloyloxy group.
In the present disclosure, the average thickness of a layer or film is defined 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, a scanning stylus meter, an optical interference film thickness measuring device, etc. In the present disclosure, when the thickness of the layer or film can be measured directly, it is measured using an optical interference film thickness measuring device. 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.

<Photosensitive resin composition>
The photosensitive resin composition of the present disclosure comprises:
A polyimide precursor having a polymerizable unsaturated bond and a solvent,
The solvent includes N,N'-dimethylpropionamide.

As shown in the examples described later, a photosensitive resin composition containing N,N'-dimethylpropionamide as a solvent exhibits excellent storage stability at room temperature.
Furthermore, a photosensitive resin composition containing N,N'-dimethylpropionamide as a solvent has a lower viscosity than a photosensitive resin composition containing the same amount of another solvent, i.e., by using N,N'-dimethylpropanamide as a solvent, the amount of solvent required to adjust the resin composition to a predetermined viscosity can be reduced.
If the amount of solvent contained in the photosensitive resin composition can be reduced, it is expected that there will be an effect of reducing the amount of solvent remaining after curing.

The components contained in the photosensitive resin composition of the present disclosure are described below. The photosensitive resin composition of the present disclosure is preferably a negative photosensitive resin composition (i.e., a resin composition that forms a pattern by removing unexposed areas).

(Unsaturated polyimide precursor)
The photosensitive resin composition of the present disclosure contains 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 synthesized using a tetracarboxylic dianhydride and a diamine compound. The unsaturated polyimide precursor may be synthesized using a tetracarboxylic acid instead of a tetracarboxylic dianhydride.

The unsaturated polyimide precursor preferably has a structural unit represented by the following general formula (1):

In formula (1), X represents a tetravalent organic group, and Y represents a divalent organic group. ^R6 and ^R7 each independently represent a hydrogen atom or a monovalent organic group, and at least one of ^R6 and ^R7 has a polymerizable unsaturated bond.

The unsaturated 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 unsaturated polyimide precursor has a plurality of structural units represented by the above general formula (1), the combination 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 1 to 4 benzene rings, more preferably contains 1 to 3 benzene rings, and even more preferably contains 1 or 2 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 them, 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, and in the following formula (E), C is more preferably a group containing an ether bond, and even more preferably an ether bond. The following formula (F) is a structure in which C in the following formula (E) 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 comprising at least two of these. C preferably contains an ether bond, and is preferably an ether bond.
In addition, C may include a structure represented by the following formula (C1).

The alkylene group represented by C in formula (E) is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably an alkylene group having 1 or 2 carbon atoms.
Specific examples of the alkylene group represented by C in formula (E) include linear alkylene groups such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; a methylmethylene group, a methylethylene group, an ethylmethylene group, a dimethylmethylene group, a 1,1-dimethylethylene group, a 1-methyltrimethylene group, a 2-methyltrimethylene group, an ethylethylene group, a 1-methyltetramethylene group, a 2-methyltetramethylene group, a 1-ethyltrimethylene group, a 2-ethyltrimethylene group, a 1,1-dimethyl branched alkylene groups such as ethyltrimethylene group, 1,2-dimethyltrimethylene group, 2,2-dimethyltrimethylene group, 1-methylpentamethylene group, 2-methylpentamethylene group, 3-methylpentamethylene group, 1-ethyltetramethylene group, 2-ethyltetramethylene group, 1,1-dimethyltetramethylene group, 1,2-dimethyltetramethylene group, 2,2-dimethyltetramethylene group, 1,3-dimethyltetramethylene group, 2,3-dimethyltetramethylene group, and 1,4-dimethyltetramethylene group. Among these, a methylene group is preferred.

The halogenated alkylene group represented by C in formula (E) is preferably a halogenated alkylene group having 1 to 10 carbon atoms, more preferably a halogenated alkylene group having 1 to 5 carbon atoms, and even more preferably a halogenated alkylene group having 1 to 3 carbon atoms.
Specific examples of the halogenated alkylene group represented by C in formula (E) include alkylene groups in which at least one hydrogen atom contained in the alkylene group represented by C in formula (E) is substituted with a halogen atom such as a fluorine atom or a chlorine atom. Among these, a fluoromethylene group, a difluoromethylene group, a hexafluorodimethylmethylene group, etc. are preferred.

The alkyl group represented by R ^A or R ^B contained in the silylene bond or siloxane bond is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms. Specific examples of the alkyl group represented by R ^A or R ^B 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, a t-butyl group, and the like.

Specific examples of the tetravalent organic group represented by X may be groups represented by the following formulae (J) to (O).

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 an insulating film 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'"), and from the viewpoint of having a flexible skeleton and excellent bonding properties, a group represented by the following formula (H') or formula (H") is more preferable.

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 formula (A) and Y is a group represented by formula (H).

R ⁶ and R ⁷ each independently represent a hydrogen atom or a monovalent organic group, with the proviso that at least one of them has a polymerizable unsaturated 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. Furthermore, 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 imidization.

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 unsaturated 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. The upper limit is not particularly limited, and 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 unsaturated polyimide precursor may be synthesized using a tetracarboxylic dianhydride and a diamine compound. In this 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 unsaturated polyimide precursor may be synthesized using a tetracarboxylic acid instead of the 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 unsaturated 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 can be measured, for example, by gel permeation chromatography, and can be calculated using a standard polystyrene calibration curve.

The photosensitive resin composition of the present disclosure may further contain a dicarboxylic acid, and the unsaturated polyimide precursor contained in the photosensitive resin composition may have a structure in which a part of the amino group in the unsaturated polyimide precursor reacts with a carboxy group in the dicarboxylic acid. For example, when synthesizing the unsaturated polyimide precursor, a part of the amino group of a 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 unsaturated polyimide precursor, a part of the amino group of the diamine compound is reacted with a carboxy group of the dicarboxylic acid, whereby a methacryl group derived from the dicarboxylic acid can be introduced into the unsaturated polyimide precursor.

(Polyimide resin)
The photosensitive resin composition of the present disclosure may contain a polyimide resin in addition to the unsaturated polyimide precursor. By combining the unsaturated polyimide precursor and the polyimide resin, it is possible to suppress the generation of volatile matter due to dehydration cyclization during imide ring formation, and therefore the generation of voids tends to be suppressed. The polyimide resin referred to here refers to a resin having an imide skeleton in all or part of the resin skeleton. It is preferable that the polyimide resin is soluble in a solvent in the photosensitive resin composition using the unsaturated polyimide precursor.

The polyimide resin is not particularly limited as long as it is a polymeric compound having a plurality of structural units including imide bonds, and it is preferable that the polyimide resin contains, for example, a compound having a structural unit represented by the following general formula (X). This tends to result in a semiconductor device having an insulating film that exhibits high reliability.

In 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 general formula (X) are the same as the preferred examples of the substituents X and Y in general formula (1) described above.

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

The photosensitive resin composition of the present disclosure may contain other resins in addition to the unsaturated polyimide precursor and polyimide resin. Examples of the 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., from the viewpoint of heat resistance. The other resins may be used alone or in combination of two or more.

In the photosensitive resin composition of the present disclosure, the content of the unsaturated polyimide precursor relative to the total amount of solids 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.
The solid content refers to the residue when the photosensitive resin composition is dried at 200 to 400°C.

(solvent)
The photosensitive resin composition of the present disclosure contains N,N'-dimethylpropionamide as a solvent.

From the viewpoint of reducing the amount of solvent contained in the photosensitive resin composition while exhibiting excellent storage stability, the proportion of N,N'-dimethylpropionamide in the solvent contained in the photosensitive resin composition is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, particularly preferably 95% by mass or more, extremely preferably 99% by mass or more, and may be 100% by mass.

The photosensitive resin composition of the present disclosure may contain a solvent (other solvent) other than N,N'-dimethylpropionamide.
The other solvents may be used alone or in combination of two or more.
Examples of other solvents include ester solvents, ether solvents, ketone solvents, hydrocarbon solvents, aromatic hydrocarbon solvents, sulfoxide solvents, carbonate solvents, and urea solvents.

Ester solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate, isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate, γ-butyrolactone, ε-caprolactone, δ-valerolactone, alkyl alkoxy acetates such as methyl alkoxy acetate, ethyl alkoxy acetate, and butyl alkoxy acetate (e.g., methyl methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, and ethyl ethoxyacetate), alkyl 3-alkoxypropionates such as methyl 3-alkoxypropionate and ethyl 3-alkoxypropionate (e.g., methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, and ethyl 3-ethoxypropionate), and alkyl 3-alkoxypropionates such as ethyl 3-alkoxypropionate. 2-alkoxypropionic acid alkyl esters such as methyl 2-methoxypropionate, ethyl 2-methoxypropionate, propyl 2-methoxypropionate, methyl 2-ethoxypropionate and ethyl 2-ethoxypropionate, methyl 2-alkoxy-2-methylpropionate such as methyl 2-methoxy-2-methylpropionate, ethyl 2-alkoxy-2-methylpropionate such as ethyl 2-ethoxy-2-methylpropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl 2-oxobutanoate, ethyl 2-oxobutanoate, etc.

Examples of ether solvents include diethylene glycol dimethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate.
Examples of the ketone solvent include methyl ethyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, 3-heptanone, and N-methyl-2-pyrrolidone (NMP).
Examples of the hydrocarbon solvent include limonene.
Examples of aromatic hydrocarbon solvents include toluene, xylene, and anisole.
An example of a solvent for sulfoxides is dimethyl sulfoxide.
Examples of carbonate-based solvents include propylene carbonate, ethylene carbonate, and dimethyl carbonate.
Examples of the urea-based solvent include tetramethylurea and 1,3-dimethyl-2-imidazolidinone.

(Crosslinking Agent)
The photosensitive resin composition may contain a crosslinking agent that can be crosslinked or polymerized by heating.
In the process of applying, exposing, developing and then heat-treating the photosensitive resin composition, the crosslinking compound reacts with the unsaturated polyimide precursor to form a crosslink, or the crosslinking compound itself polymerizes. This increases the strength of the resulting cured film even at a relatively low curing temperature, for example, 200° C. or lower, and improves the mechanical properties, chemical resistance, flux resistance, etc.
The crosslinking agent may be used alone or in combination of two or more kinds.

The crosslinking agent may be a compound having two or more groups containing a polymerizable unsaturated bond (hereinafter also referred to as functional group). 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.
The crosslinking agent may be subjected to an alkoxylation treatment such as ethoxylation or propoxylation.

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, 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 photosensitive resin composition of the present disclosure 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 unsaturated polyimide precursor.

(Photopolymerization initiator)
The photosensitive resin composition of the present disclosure may contain a photopolymerization initiator.
The photopolymerization initiator is not particularly limited as long as it is a compound capable of generating radicals when irradiated with actinic rays, such as ultraviolet rays such as i-rays, visible light, and radiation.

Photopolymerization initiators include oxime compounds, acylphosphine oxide compounds, acyldialkoxymethane compounds, etc.

The photopolymerization initiator may be a compound represented by the following general formula (9A), a compound represented by the following general formula (9B), a compound represented by the following general formula (10A), or a compound represented by the following general formula (10B).

 

In general formula (9A), R ¹¹ is an alkyl group having 1 to 12 carbon atoms, and a1 is an integer of 0 to 5. R ¹² is a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R ¹³ and R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, or a tolyl group. When a1 is an integer of 2 or more, R ¹¹ may be the same or different.

R ¹¹ is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group. a1 is preferably 1. R ¹² is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an ethyl group. R ¹³ and R ¹⁴ are preferably each independently an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group.

An example of the compound represented by general formula (9A) is the compound represented by the following formula (9A-1), which is available as "IRGACURE OXE 02" manufactured by BASF Japan Ltd.

 

 

In general formula (9B), R ¹⁵ is -OH, -COOH, -OCH ₂ OH, -O(CH ₂ ) ₂ OH, -COOCH ₂ OH or -COO(CH ₂ ) ₂ OH, and R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 4 to 10 carbon atoms, a phenyl group or a tolyl group. b1 is an integer of 0 to 5. When b1 is an integer of 2 or more, R ¹⁵ may be the same or different.
R ¹⁵ is preferably —O(CH ₂ ) ₂ OH. b1 is preferably 0 or 1. R ¹⁶ is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or a hexyl group. R ¹⁷ is preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group, more preferably a methyl group or a phenyl group.

Examples of the compound represented by general formula (9B) include the compound represented by the following formula (9B-1), available as "IRGACURE OXE 01" manufactured by BASF Japan Ltd. Also included is the compound represented by the following formula (9B-2), available as "NCI-930" manufactured by ADEKA Corporation.

 

 

In general formula (10A), R ²¹ is an alkyl group having 1 to 12 carbon atoms, R ²² and R ²³ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (preferably 1 to 4 carbon atoms), an alkoxy group having 1 to 12 carbon atoms (preferably 1 to 4 carbon atoms), a cycloalkyl group having 4 to 10 carbon atoms, a phenyl group, or a tolyl group, and c1 is an integer of 0 to 5. When c1 is an integer of 2 or more, R ²¹ may be the same or different.
c1 is preferably 0. R ²² is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group. R ²³ is preferably an alkoxy group having 1 to 12 carbon atoms, more preferably an alkoxy group having 1 to 4 carbon atoms, and even more preferably a methoxy group or an ethoxy group.
An example of the compound represented by general formula (10A) is the compound represented by the following formula (10A-1) (1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime). This compound is available as "G-1820 (PDO)" manufactured by Lambson.

 

 

In the general formula (10B), R ²⁴ and R ²⁵ are each independently an alkyl group having 1 to 12 carbon atoms (preferably 1 to 4 carbon atoms), d and e are each independently an integer of 0 to 5, s and t are each independently an integer of 0 to 3, and the sum of s and t is 3. When d is an integer of 2 or more, R ²⁴ may be the same or different. When e is an integer of 2 or more, R ²⁵ may be the same or different. When s is an integer of 2 or more, the groups in the parentheses may be the same or different. When t is an integer of 2 or more, the groups in the parentheses may be the same or different.
d is preferably 0. ^{R 25} is preferably each independently an alkyl group having 1 to 4 carbon atoms, and is preferably a methyl group. e is preferably an integer of 2 to 4, and more preferably 3. The combination of s and t (s, t) is preferably (1, 2) or (2, 1).
Examples of the compound represented by general formula (10B) include a compound represented by the following formula (10B-1), which is available as "IRGACURE TPO" manufactured by BASF Japan Ltd. Also included are compounds represented by the following formula (10B-2), which is available as "IRGACURE 819" manufactured by BASF Japan Ltd.

 

The content of the photopolymerization initiator 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 6 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(Thermal Polymerization Initiator)
The photosensitive resin composition of the present disclosure may further contain a thermal polymerization initiator from the viewpoint of promoting the polymerization reaction.
As the thermal polymerization initiator, a compound that does not decompose when heated (dried) to remove a solvent during film formation but decomposes when heated during curing to generate radicals and promotes a polymerization reaction between polymerizable monomers or between an unsaturated polyimide precursor and a polymerizable monomer is preferred.
The thermal polymerization initiator is preferably a compound having a decomposition point of 110° C. to 200° C., and from the viewpoint of promoting the polymerization reaction at a lower temperature, a compound having a decomposition point of 110° C. to 175° C. is more preferable.

Specific examples of the thermal polymerization initiator 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, and p-menthane hydroperoxide, dialkyl peroxides such as dicumyl peroxide and di-t-butyl peroxide, dialkyl peroxides such as dicyclohexane, dicyclohexane, and dicyclohexane. Examples of the peroxyester include diacyl peroxides such as diuroyl peroxide and dibenzoyl peroxide; peroxydicarbonates such as di(4-t-butylcyclohexyl)peroxydicarbonate and di(2-ethylhexyl)peroxydicarbonate; peroxyesters 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.
Commercially available products include those under the trade names "Percumyl D", "Percumyl P", and "Percumyl H" (all manufactured by NOF Corporation).

When the photosensitive resin composition of the present disclosure contains a thermal polymerization initiator, the content of the thermal polymerization initiator is preferably 0.1 parts by mass to 20 parts by mass relative to 100 parts by mass of the unsaturated polyimide precursor, more preferably 0.2 parts by mass to 20 parts by mass to ensure good flux resistance, and even more preferably 0.3 parts by mass to 10 parts by mass from the viewpoint of suppressing a decrease in solubility due to decomposition during drying.

(Imidization accelerator)
The resin composition of the present disclosure may contain a nitrogen-containing compound as an imidization accelerator from the viewpoint of accelerating the imidization reaction.

Specific examples of nitrogen-containing compounds include 2-(methylphenylamino)ethanol, 2-(ethylanilino)ethanol, N-methylaniline, N-ethylaniline, N,N'-dimethylaniline, N-phenylethanolamine, 4-phenylmorpholine, 2,2'-(4-methylphenylimino)diethanol, 4-aminobenzamide, 2-aminobenzamide, nicotinamide, 4-amino-N-methylbenzamide, 4-aminoacetanilide, 4-aminoacetophenone, etc., and among these, N-methylaniline, N-ethylaniline, N,N'-dimethylaniline, N-phenylethanolamine, 4-phenylmorpholine, 2,2'-(4-methylphenylimino)diethanol, etc. are preferred. The nitrogen-containing compounds may be used alone or in combination of two or more.

When the photosensitive resin composition of the present disclosure contains an imidization accelerator, the content of the imidization accelerator is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the unsaturated polyimide precursor, and from the viewpoint of storage stability, is more preferably 0.3 to 15 parts by mass, and even more preferably 0.5 to 10 parts by mass.

(Sensitizer)
The photosensitive resin composition of the present disclosure may contain a sensitizer. By containing a sensitizer in the photosensitive resin composition, it is possible to maintain both the remaining film rate and good resolution in a wide range of exposure doses. The sensitizer may be used alone or in combination of two or more kinds.

Sensitizers include Michler's ketone, benzoin, 2-methylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, anthraquinone, methylanthraquinone, 4,4'-bis(diethylamino)benzophenone, acetophenone, benzophenone, thioxanthone, 1,5-acenaphthene, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, diacetyl benzyl, and benzyl dimethyl ketone. Tar, benzyl diethyl ketal, diphenyl disulfide, anthracene, phenanthrenequinone, riboflavin tetrabutylate, acridine orange, erythrosine, phenanthrenequinone, 2-isopropylthioxanthone, 2,6-bis(p-diethylaminobenzylidene)-4-methyl-4-azacyclohexanone, 6-bis(p-dimethylaminobenzylidene)-cyclopentanone, 2,6-bis(p-diethylaminobenzylidene)-4-phenylcyclohexanone, aminostyryl ketone, 3-ketocoumarin compounds, biscoumarin compounds, N-phenylglycine, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, etc.

When the photosensitive resin composition of the present disclosure contains a sensitizer, the amount of the sensitizer is not particularly limited, but is preferably 0.1 to 1.0 parts by mass, and more preferably 0.2 to 0.8 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(Stabilizer)
The photosensitive resin composition of the present disclosure may contain a stabilizer. When the photosensitive resin composition contains a stabilizer, the storage stability can be improved.

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.

The stabilizer may be used alone or in combination of two or more types. By combining two or more stabilizers, the photosensitive characteristics tend to be easier to adjust due to differences in reactivity. The hindered phenol compound may have both the function of a stabilizer and the function of an antioxidant described below, or it may have only one function.

Stabilizers include, for example, 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butyl-hydroquinone, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-thio-bis(3-methyl-6-t-butylphenol), 4,4'-butylidene-bis(3-methyl-6-t-butylphenol), thiamine, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylene bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylene bis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2, 2'-methylene-bis(4-ethyl-6-t-butylphenol), pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-isopropylbenzyl)-1,3,5-triazine-2,4,6-(1H, 3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-s-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione 1,3,5-tris[4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5,6-trimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5- Tris(4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5- Tris(4-t-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl -5-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], 2,2,6,6-tetramethylpiperidine 1-oxyl, 4-hydroxy-2,2,6,6,-tetramethylpiperidine 1-oxyl, and 1,4,4-trimethyl-2,3-diazabicyclo[3.2.2]non-2-ene-2,3-dioxide.

When the photosensitive resin composition of the present disclosure 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 unsaturated polyimide precursor.

(Antioxidants)
The photosensitive resin composition of the present disclosure may contain an antioxidant from the viewpoint of suppressing a decrease in adhesiveness by capturing oxygen radicals and peroxide radicals generated during high-temperature storage, reflow treatment, etc. When the photosensitive resin composition of the present disclosure contains an antioxidant, oxidation of the electrode during an insulation reliability test can be suppressed.

Specific examples of the antioxidant include the compounds exemplified above as the 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 photosensitive resin composition of the present disclosure contains an antioxidant, the content of the antioxidant is preferably 0.1 parts by mass to 20 parts by mass, more preferably 0.1 parts by mass to 10 parts by mass, and even more preferably 0.1 parts by mass to 5 parts by mass, relative to 100 parts by mass of the unsaturated polyimide precursor.

(Coupling Agent)
The photosensitive resin composition of the present disclosure may contain a coupling agent. By containing a coupling agent, the adhesion between the obtained cured product and a substrate can be further improved.

The coupling agent is not particularly limited, and examples thereof include 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalamic acid, benzophenone-3,3'-bis(N-[3-tolyl ... silane coupling agents such as N-[3-triethoxysilyl]propylamido)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamido)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, N-phenylaminopropyltrimethoxysilane, N,N'-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, 3-ureidopropyltriethoxysilane; aluminum-based adhesion aids such as aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), ethylacetoacetate aluminum diisopropylate, and the like.
The coupling agents may be used alone or in combination of two or more.

When the photosensitive resin composition of the present disclosure contains a coupling agent, the content of the coupling agent is preferably 0.1 parts by mass to 20 parts by mass, more preferably 1 part by mass to 10 parts by mass, and even more preferably 2 parts by mass to 10 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(Rust inhibitor)
The photosensitive resin composition of the present disclosure may contain a rust inhibitor. When the photosensitive resin composition contains a rust inhibitor, corrosion of copper and copper alloys can be suppressed and discoloration can be prevented.
Examples of the rust inhibitor include azole compounds and purine derivatives.
The rust inhibitors may be used alone or in combination of two or more.

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.

When the photosensitive resin composition of the present disclosure contains a rust inhibitor, the content of the rust inhibitor is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass, and even more preferably 0.5 parts by mass to 3 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(Ultraviolet absorber)
The photosensitive resin composition of the present disclosure may contain an ultraviolet absorber. When the photosensitive resin composition contains an ultraviolet absorber, crosslinking in unexposed areas due to diffuse reflection during exposure tends to be suppressed.
Examples of the ultraviolet absorbent 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 absorbent may be used alone or in combination of two or more kinds.

Benzotriazole compounds include 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole, 2-(3-tert-butyl-2-hydroxy-5-methylphenyl)-5-chloro-2H-benzotriazole, 2-(3,5-di-tert-pentyl-2-hydroxyphenyl)-2H-benzotriazole, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidylmethyl)phenol, 2- (2-hydroxy-4-octyloxyphenyl)-2H-benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)-2H-benzotriazole, 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-p-cresol), etc.

Examples of salicylic acid ester compounds include phenyl salicylate and 4-tert-butylphenyl salicylate.

Examples of benzophenone compounds include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 4-n-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid trihydrate, 2,2',4,4'-tetrahydroxybenzophenone, and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.

Diphenylacrylate compounds include ethyl 2-cyano-3,3-diphenylacrylate.

Examples of diphenyl cyanoacrylate compounds include 2-cyano-3,3-diphenylacrylic acid (2'-ethylhexyl).

Examples of azobenzene compounds include 4-[ethyl(2-hydroxyethyl)amino]-4'-nitroazobenzene.

Polyphenol compounds include pyrogallol, phloroglycine, catechin, epicatechin, gallocatechin, catechin gallate, gallocatechin gallate, epicatechin gallate, epigallocatechin gallate, epigallocatechin, rutin, quercetin, quercetagin, quercetagetin, gossypetin, pelargonidin, cyanidin, aurantidin, luteolinidin, peonidin, rosinidin, (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, and 1,7-bis(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione.

Examples of polyphenol compounds include [2,2'-thiobis(4-tert-octylphenolate)]-2-ethylhexylamine nickel(II).

Among the above, it is preferable to use at least one selected from the group consisting of benzotriazole-based compounds, benzophenone-based compounds, azobenzene-based compounds, and polyphenol-based compounds as the material ray absorbent.

Furthermore, from the viewpoint of resolution, it is more preferable to use at least one ultraviolet absorber selected from the group consisting of 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol, 2-(2H-benzotriazol-2-yl)-p-cresol), 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 4-[ethyl(2-hydroxyethyl)amino]-4'-nitroazobenzene, (1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, and 1,7-bis(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione.

When the photosensitive resin composition of the present disclosure contains an ultraviolet absorber, the content of the ultraviolet absorber is, from the viewpoint of resolution, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the unsaturated polyimide precursor.
Furthermore, from the viewpoint of preventing insufficient photocuring inside the coating film, the amount is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less.

(Surfactants and Leveling Agents)
The photosensitive resin composition of the present disclosure may contain at least one of a surfactant and a leveling agent. When the photosensitive resin composition contains at least one of a surfactant and a leveling agent, the coating property (e.g., suppression of striation (unevenness in film thickness)) and the developability can be improved.

Surfactants or leveling agents include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, etc. Commercially available products include products under the trade names "Megafac (registered trademark) F171", "F173", and "R-08" (all manufactured by DIC Corporation), "Fluorad FC430" and "FC431" (all manufactured by Sumitomo 3M Limited), and "Organosiloxane Polymer KP341", "KBM303", and "KBM803" (all manufactured by Shin-Etsu Chemical Co., Ltd.).

The surfactants and leveling agents may be used alone or in combination of two or more.

When the photosensitive resin composition of the present disclosure contains at least one of a surfactant and a leveling agent, the total content of the surfactant and leveling agent is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.05 parts by mass to 5 parts by mass, and even more preferably 0.05 parts by mass to 3 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(Other ingredients)
The photosensitive resin composition of the present disclosure may further contain other components and unavoidable impurities.
In the photosensitive resin composition of the present disclosure, the total amount of the unsaturated polyimide precursor, the crosslinking agent, the photopolymerization initiator, and the solvent may be 80% by mass or more, 90% by mass or more, or 95% by mass or more.
In addition, in the photosensitive resin composition of the present disclosure, the total amount of the unsaturated polyimide precursor, the crosslinking agent, the photopolymerization initiator, the solvent, the stabilizer, the sensitizer, the UV absorber, the rust inhibitor, the antioxidant, and the coupling agent may be 80% by mass or more, 90% by mass or more, 95% by mass or more, 97% by mass or more, 98% by mass or more, or 99% by mass or more.

<Cured product>
The cured product of the present disclosure can be obtained by curing the photosensitive resin composition of the present disclosure.
The cured product of the present disclosure may be used as a patterned cured product or as a non-patterned cured product.
The average thickness of the cured product is preferably 5 μm to 20 μm.

The breaking elongation of the cured product is preferably 25% or more, more preferably 35% or more, and even more preferably 50% or more. There is no particular upper limit to the breaking elongation of the cured product.

<Method for producing cured product, and electronic component>
The method for producing a patterned cured product of the present disclosure includes a step of applying the photosensitive resin composition of the present disclosure onto a substrate and drying to form a photosensitive resin film, a step of exposing the photosensitive resin film to a pattern to obtain a resin film, a step of developing the resin film after the patterned exposure using a developer to obtain a patterned resin film, and a step of heat-treating the patterned resin film.
In this way, a patterned cured product can be obtained.

A method for producing a patternless cured product includes, for example, a step of forming a photosensitive resin film of the present disclosure and a step of performing a heat treatment. It may further include a step of exposing the film to light.

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, and copper alloy substrates.

There are no particular limitations on the method for applying the photosensitive resin composition disclosed herein, and it can be done using a spinner or the like.

The drying can be carried out using a hot plate, an oven, or the like.
The drying temperature is preferably from 90° C. to 150° C., and from the viewpoint of ensuring the dissolution contrast, it is more preferably from 90° C. to 120° C.
The drying time is preferably from 30 seconds to 5 minutes.
The drying may be carried out two or more times.
This makes it possible to obtain a photosensitive resin film in which the photosensitive resin composition of the present disclosure is formed into a film shape.

The average thickness of the photosensitive resin film is preferably 1 μm to 100 μm, more preferably 2 μm to 50 μm, and even more preferably 3 μm to 30 μm.

The pattern exposure is performed by exposing a predetermined pattern through a photomask, for example.
The actinic rays to be irradiated include ultraviolet rays such as i-rays, visible light, and radiation, and are preferably i-rays.
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.

By developing, a resin film having a pattern formed thereon (patterned resin film) can be obtained. In general, when a negative type 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.
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.

A surfactant may be added to the developer. The amount added is preferably 0.01 parts by weight to 10 parts by weight, and more preferably 0.1 parts by weight to 5 parts by weight, per 100 parts by weight of the developer.

The development time can be set to, for example, twice the time required for the photosensitive resin film to be immersed and completely dissolved.
The developing time varies depending on the unsaturated polyimide precursor used, but is preferably from 10 seconds to 15 minutes, more preferably from 10 seconds to 5 minutes, and from the viewpoint of productivity, further preferably from 20 seconds to 5 minutes.

After development, washing may be carried out with a rinsing liquid.
As the rinse liquid, distilled water, methanol, ethanol, isopropanol, toluene, xylene, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, etc. may be used alone or in appropriate mixture, or in stepwise combination.

By subjecting the patterned resin film to a heat treatment, a patterned cured product can be obtained.
The unsaturated polyimide precursor undergoes a dehydration ring-closing reaction during the heat treatment step to become the corresponding 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.
When the heat treatment time is within the above range, the crosslinking reaction or the dehydration ring-closing reaction can proceed sufficiently.
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 as an interlayer insulating film, a cover coat layer, or a surface protective film. Furthermore, the cured product of the present disclosure can be used as a passivation film, a buffer coat film, etc.
Using one or more selected from the group consisting of the above passivation films, buffer coat films, interlayer insulating films, cover coat layers, and surface protection films, etc., highly reliable electronic components such as semiconductor devices, multilayer wiring boards, various electronic devices, and stacked devices (multi-die fan-out wafer level packages, etc.) can be manufactured.

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 photosensitive 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 photosensitive 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 Unsaturated Polyimide Precursor>
A 2L separable flask was charged with 380 g of N-methyl-2-pyrrolidone (NMP, Mitsubishi Chemical Corporation), 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, and the 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 added dropwise, and then stirred at 30°C for 3 hours. Next, 59.7g (284mmol) of TFAA (trifluoroacetic anhydride, Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise to the reaction solution at 30°C, and stirred at 45°C for 2 hours. Next, 0.08g (0.74mmol) of BQ (benzoquinone, Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction solution, and 40.4g (310mmol) of HEMA was added dropwise. The reaction solution was stirred for 15 hours, and then cooled to room temperature. The reaction solution was poured into purified water, and the precipitate was collected. The precipitate was washed with purified water and dried under reduced pressure to obtain an unsaturated polyimide precursor (unsaturated PI precursor in the table).
The weight average molecular weight (Mw) of the unsaturated polyimide precursor was 25,000.

The weight-average molecular weight of the unsaturated polyimide precursor was calculated by gel permeation chromatography (GPC) using a calibration curve based on TSKgel standard polystyrene (Tosoh Corporation). The equipment 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: 10μL

<Preparation of Photosensitive Resin Composition>
A homogeneous solution was prepared by mixing the components shown in Table 1 in the amounts shown in Table 1. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter having a pore size of 1 μm to obtain a photosensitive resin composition.
The viscosity (unit: mPa·s) of the resulting photosensitive composition at 25° C. was measured using a B-type rotational viscometer. The results are shown in Table 1.

Details of each component shown in Table 1 are as follows: The blending amount of each component in Table 1 is based on parts by mass.
Solvent 1: γ-butyrolactone (boiling point: 204°C)
Solvent 2: 3-methoxy-N,N'-dimethylpropanamide (boiling point: 215°C)
Solvent 3: N,N'-dimethylpropionamide (boiling point: 174.5°C)
Stabilizer: 1,4,4-trimethyl-2,3-diazabicyclo[3.2.2]non-2-ene-2,3-dioxide Crosslinker: Tetraethylene glycol dimethacrylate Photopolymerization initiator: 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime Coupling agent: 3-ureidopropyltriethoxysilane Rust inhibitor: 5-amino-1H-tetrazole

<HSP value of solvent>
Table 1 shows the dispersion force term (δD), polarity term (δP) and hydrogen bond term (δH), which are components of the HSP (Hansen solubility parameter) of the solvent used in the preparation of the photosensitive resin composition.

<Evaluation of storage stability 1>
A PB film and a developed film were prepared using the initial photosensitive resin composition (immediately after preparation) and the photosensitive resin composition after storage at room temperature (25° C.) for one or two weeks.
Specifically, the photosensitive resin composition was applied onto a Si wafer by spin coating to form a coating film, which was then prebaked (PB) at 100° C. for 2 minutes and then at 110° C. for 2 minutes to obtain a PB film having a thickness of 6.9±0.5 μm.
The PB film was exposed to light (exposure dose: 400 mJ/ ^cm2 ) using an i-line stepper and developed using cyclopentanone (10 seconds x 2 times) to obtain a developed film having a pattern consisting of 7 μm-wide lines (exposed areas) and 7 μm-wide spaces (unexposed areas).

The film thickness change rate was calculated from the film thickness of the PB film prepared using the initial photosensitive resin composition and the film thickness of the PB film prepared using the photosensitive resin composition after storage according to the following formula, and evaluated according to the following criteria. The results are shown in Table 1.
Film thickness change rate (%) = {(film thickness after storage/initial film thickness) × 100} - 100
A: The rate of change in film thickness is within ±2%. B: The rate of change in film thickness exceeds ±2%.

The residual film ratio of the post-development film prepared using the initial photosensitive resin composition and the residual film ratio of the post-development film prepared using the photosensitive resin composition after storage were each calculated by the following formula.
Residual film ratio (%)=(film thickness of exposed area after development/film thickness after PB)×100

Next, the residual film ratio of the film after development prepared using the initial photosensitive resin composition (initial residual film ratio) and the residual film ratio of the film after development prepared using the photosensitive resin composition after storage (residual film ratio) were calculated by the following formula and evaluated according to the following criteria. The results are shown in Table 1.
Change in remaining film ratio (%)={(remaining film ratio after storage/initial remaining film ratio)×100}−100
A: The rate of change in the remaining film ratio is within ±2%. B: The rate of change in the remaining film ratio exceeds ±2%.

<Evaluation of storage stability 2>
The developed film obtained in Evaluation of Storage Stability 1 was subjected to a curing treatment at 230° C. for 2 hours under a nitrogen atmosphere to prepare a cured film. The PB film was exposed to light at 200 J/cm ² , 300 J/cm ² and 400 mJ/cm ² . The cured film was cut, and the state of the cross section of the cured film was evaluated according to the following criteria. The results are shown in Table 1.
A: No pattern formation defect or peeling of the cured film is observed. B: No pattern formation defect or peeling of the cured film is observed.

As shown in Table 1, the photosensitive resin composition of Example 1, which uses N,N'-dimethylpropionamide as a solvent, has a sufficiently small change in film thickness and residual film ratio after storage at room temperature for one or two weeks. In addition, the state of the cured film obtained after storage of the photosensitive resin composition at room temperature for one or two weeks is also good. From the above results, it can be determined that the photosensitive resin composition of Example 1 has excellent storage stability.
Furthermore, the viscosity of the photosensitive resin composition of Example 1 was lower than the viscosities of the photosensitive resin compositions of Comparative Examples 1 and 2, which used γ-butyrolactone or 3-methoxy-N,N'-dimethylpropanamide as the solvent. This result suggests that the amount of solvent contained in the photosensitive resin composition can be reduced by using N,N'-dimethylpropionamide as the solvent.
Surprisingly, it was found that the N,N'-dimethylpropionamide used in Example 1 significantly reduced the viscosity of the photosensitive resin composition, even though it has properties (HSP) similar to those of the 3-methoxy-N,N'-dimethylpropanamide used in Comparative Example 1.

Claims (8)

A polyimide precursor having a polymerizable unsaturated bond and a solvent,
The photosensitive resin composition, wherein the solvent comprises N,N'-dimethylpropionamide. 2. The photosensitive resin composition according to claim 1, wherein the polyimide precursor having a polymerizable unsaturated bond has a structural unit represented by the following general formula (1):

(In general formula (1), X represents a tetravalent organic group, and Y represents a divalent organic group. ^R6 and ^R7 each independently represent a hydrogen atom or a monovalent organic group, and at least one of ^R6 and ^R7 has a polymerizable unsaturated bond.) The photosensitive resin composition according to claim 1, further comprising a photopolymerization initiator. The photosensitive resin composition according to claim 1, wherein the proportion of N,N'-dimethylpropionamide in the solvent is 50% by mass or more. A step of applying the photosensitive resin composition according to any one of claims 1 to 4 onto a substrate and drying the composition to form a photosensitive resin film;
a step of exposing the photosensitive resin film to a pattern to obtain a resin film;
developing the resin film after the patterned exposure with a developer to obtain a patterned resin film;
and heat-treating the patterned resin film. A patterned cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 4. The patterned cured product according to claim 6, which is used as an interlayer insulating film, a cover coat layer, or a surface protective film. An electronic component comprising the patterned cured product according to claim 6.