WO2024209647A1 - Photosensitive resin composition, method for producing patterned cured product, cured product, and electronic component - Google Patents

Abstract

This photosensitive resin composition contains: a polyimide precursor having a polymerizable unsaturated bond; and at least one among a nitrogen-containing compound having a solubility parameter of 32 or greater and a hydroxyl group, and a nitrogen-containing compound having a solubility parameter of 39 or greater.

Description

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

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

Conventionally, polyimide, polybenzoxazole, and the like, which have excellent heat resistance and electrical and mechanical properties, have been used for the surface protective films and interlayer insulating films of semiconductor elements. In recent years, photosensitive resin compositions in which these resins themselves have been given photosensitivity have been used, and their use can simplify the manufacturing process for patterned cured products and shorten the complicated manufacturing process (see, for example, Patent Document 1).

JP 2009-265520 A

In order to prevent a decrease in yield during production, it is desirable to cure photosensitive polyimide precursors at lower temperatures than before. However, curing photosensitive polyimide precursors at low temperatures reduces the peel strength, which is an indicator of adhesion and adhesion to copper substrates.

In view of the above-mentioned conventional circumstances, one embodiment of the present disclosure aims to provide a photosensitive resin composition that can improve the peel strength against a copper substrate even when cured at a lower temperature than conventionally, as well as a cured product using this photosensitive resin composition, a method for producing a patterned cured product, and an electronic component.

Specific means for achieving the above object are as follows.
<1> A photosensitive resin composition comprising: a polyimide precursor having a polymerizable unsaturated bond; and at least one selected from the group consisting of a nitrogen-containing compound having a solubility parameter of 32 or more and having a hydroxyl group, and a nitrogen-containing compound having a solubility parameter of 39 or more.
<2> The photosensitive resin composition according to <1>, wherein the nitrogen-containing compound includes inosine.
<3> The photosensitive resin composition according to <1> or <2>, 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.)
<4> The photosensitive resin composition according to any one of <1> to <3>, further comprising at least one selected from the group consisting of a polymerizable monomer, a photopolymerization initiator, a sensitizer, a coupling agent, and a solvent.
<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 cured product obtained by curing the photosensitive resin composition according to any one of <1> to <4>.
<7> The cured product according to <6>, which is a patterned cured product.
<8> The cured product according to <6> or <7>, which is used as an interlayer insulating film, a cover coat layer, or a surface protective film.
<9> An electronic part comprising the cured product according to any one of <6> to <8>.

According to one embodiment of the present disclosure, it is possible to provide a photosensitive resin composition that can improve the peel strength against a copper substrate even when cured at a lower temperature than conventionally, as well as a cured product using this photosensitive resin composition, a method for producing a 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.
In the present disclosure, "curing at a lower temperature than conventionally" means curing at 250°C, for example.

<Photosensitive resin composition>
The photosensitive resin composition of the present disclosure comprises a polyimide precursor having a polymerizable unsaturated bond, and at least one of a nitrogen-containing compound having a solubility parameter of 32 or more and a hydroxyl group and a nitrogen-containing compound having a solubility parameter of 39 or more. Hereinafter, the "solubility parameter" may also be referred to as the SP value.

According to the photosensitive resin composition having the above-mentioned configuration, even when cured at a low temperature, it is possible to improve the peel strength to a copper substrate. The reason for this is not clear, but is presumed to be as follows.
It has been revealed that when the photosensitive resin composition is cured, the nitrogen-containing compound is likely to exist near the interface. It is believed that by increasing the SP value of the nitrogen-containing compound existing near the interface, the difference in surface free energy between the copper base material and the nitrogen-containing compound layer, and between the nitrogen-containing compound layer and the resin layer is reduced, and the peel strength is improved. It has been revealed that the above effect can be achieved by using a nitrogen-containing compound with an SP value of 39 or more, or by having a hydroxyl group in the case of a nitrogen-containing compound with an SP value of 32 or more.

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. The photosensitive resin composition of the present disclosure may further contain at least one selected from the group consisting of a polymerizable monomer, a photopolymerization initiator, a sensitizer, a coupling agent, and a solvent.

(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 combinations of R ⁶ and R ⁷ of each structural unit may be the same or different.

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

When the tetravalent organic group represented by X contains a benzene ring, the tetravalent organic group represented by X preferably contains 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 further 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 formulas (E) and (F) 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 250° C. or less. In addition, when the monovalent organic group contains an organic group having an unsaturated double bond, preferably a group represented by the following general formula (2), at least a part of the unsaturated double bond portion is eliminated by the compound (C).

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

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

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

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

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

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

When the 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 a tetracarboxylic dianhydride.

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

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

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

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

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

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

The above-mentioned compound contained in the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH to form a diester derivative, then reacting the diester 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, and more preferably 10,000 to 100,000.
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 methacryl group derived from the dicarboxylic acid can be introduced into the unsaturated polyimide precursor by reacting a part of the amino group of the diamine compound with a carboxy group of the dicarboxylic acid.

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 substances 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 the 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.

(Nitrogen-containing compounds)
The photosensitive resin composition of the present disclosure contains at least one of a nitrogen-containing compound having an SP value of 32 or more and a hydroxyl group and a nitrogen-containing compound having an SP value of 39 or more. The "nitrogen-containing compound having an SP value of 32 or more and a hydroxyl group" and the "nitrogen-containing compound having an SP value of 39 or more" are also referred to as "specific nitrogen-containing compounds". The specific nitrogen-containing compounds may be used alone or in combination of two or more.

When the nitrogen-containing compound has a hydroxyl group, the SP value of the nitrogen-containing compound is 32 or more, preferably 33 or more, more preferably 34 or more, and even more preferably 35 or more.
When the nitrogen-containing compound does not have a hydroxyl group, the SP value of the nitrogen-containing compound is 39 or more, preferably 40 or more, more preferably 40 to 43, and even more preferably 40 to 42. In addition, when the SP value is 39 or more, nitrogen-containing compounds that do not have a hydroxyl group are also included.

The SP value is a solubility parameter calculated by the Fedors method [unit: (J/cm ³ ) ^1/2 ], and is a value expressed by the following formula.
SP value [cal/ ^cm3 ) ^1/2 ]=(ΔH/V) ^1/2
SP value [J/ ^cm3 ) ^1/2 ] = (ΔH/V) ^1/2 ×2.04598
In the formula, ΔH represents the molar heat of vaporization [cal], and V represents the molar volume [cm ³ ]. As ΔH and V, the sum ΣΔei (=ΔH) of the molar heat of vaporization (Δei) of the atomic groups and the sum ΣΔvi (V) of the molar volumes (Δvi) described in "POLYMER ENGINEERING AND SCIENCE, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (pp. 151-153)" can be used, and they can be calculated from (ΣΔei/ΣΔvi) ^1/2 .

When the specific nitrogen-containing compound has a hydroxyl group, the number of the hydroxyl groups may be one, two, three, or four or more.
When the specific nitrogen-containing compound has a hydroxyl group, it may be a sugar.

The specific nitrogen-containing compounds include orotic acid (SP value: 39.1), 6-azahypoxanthine (SP value: 39.1), 6-hydrazinouracil (SP value: 39.3), pyromellitic diimide (SP value: 39.5), 5-hydroxymethyluracil (SP value: 39.7), 5-formyluracil (SP value: 39.7), 1,2,4-triazole-3-carboxamide (SP value: 39.8), 4-amino-6-hydroxypyrazolo[3,4-d]pyrimidine (SP value: 39.9), 5-methyluridine (SP value: 40.1), 8-oxoadenosine (SP value: 40.5), inosine (SP value: 40.6), 5-methyluridine (SP value: 40.7), 5-methyluridine (SP value: 40.8), 5-methyluridine (SP value: 40.9 ... P value: 40.6), 6-azauracil (SP value: 40.9), oxypurinol (SP value: 41.3), xanthine (SP value: 41.3), 5-aminoorotic acid (SP value: 41.4), luminol (SP value: 41.5), guanosine (SP value: 41.9), uracil 1-β-D-arabinofuranoside (SP value: 42.3), uridine (SP value: 42.3), 5-hydroxyuracil (SP value: 42.9), urazole (SP value: 44.0), xanthosine (SP value: 44.1), 6-azauridine (SP value: 45.0), xanthopterin (SP value: 45.2), etc.
Among the above specific nitrogen-containing compounds, from the viewpoint of suppressing the generation of a residual film in the unexposed area, it is preferable to contain inosine, uridine, etc., and it is more preferable to contain inosine.

The photosensitive resin composition of the present disclosure may contain, in addition to the specific nitrogen-containing compound, another nitrogen-containing compound. The other nitrogen-containing compound is not particularly limited as long as it is a nitrogen-containing compound having a solubility parameter of less than 32 and a hydroxyl group, or a nitrogen-containing compound having a solubility parameter of less than 39 and no hydroxyl group, and examples of the other nitrogen-containing compound include azole compounds and purine derivatives.
The other nitrogen-containing compounds may be used alone or in combination of two or more.

From the viewpoint of improving adhesion between the cured product and the copper substrate, the ratio of the total amount of specific nitrogen-containing compounds to the total amount of nitrogen-containing compounds is preferably 80% by mass or more, more preferably 85% 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 content of the nitrogen-containing compound is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 10 parts by mass, and even more preferably 2.0 parts by mass to 5 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(solvent)
Examples of the solvent include ester solvents, ether solvents, ketone solvents, hydrocarbon solvents, aromatic hydrocarbon solvents, sulfoxide solvents, etc. The solvents may be used alone or in combination of two or more.

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, and ethyl 2-oxobutanoate.

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.

Among these, N-methyl-2-pyrrolidone, γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, N,N-dimethylformamide and N,N-dimethylacetamide are preferred from the viewpoint of excellent solubility of each component and coatability when forming a photosensitive resin film.

Also, a compound represented by the following general formula (11) may be used as the solvent.

In formula (11), R ⁴¹ to R ⁴³ each independently represent an alkyl group having 1 to 10 carbon atoms.

The alkyl groups represented by R ⁴¹ to R ⁴³ in formula (11) preferably have 1 to 3 carbon atoms, and more preferably 1 or 3 carbon atoms.
Specific examples of the alkyl group having 1 to 10 carbon atoms represented by R ⁴¹ to R ⁴³ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The compound represented by the general formula (11) is preferably 3-methoxy-N,N-dimethylpropanamide (for example, trade name "KJCMPA-100" (manufactured by KJ Chemicals Co., Ltd.)).

The amount of solvent is not particularly limited, but is generally 50 to 1,000 parts by weight per 100 parts by weight of the unsaturated polyimide precursor.

(Polymerizable Monomer)
The resin composition of the present disclosure may further contain a polymerizable monomer from the viewpoint of improving the physical properties of the cured film. The polymerizable monomer may be used alone or in combination of two or more kinds.

The polymerizable monomer preferably has at least one group containing a polymerizable unsaturated double bond, and more preferably has at least one (meth)acrylic group from the viewpoint of being polymerizable by a coupling agent or the like. From the viewpoint of improving crosslink density and improving photosensitivity, it is preferable for the polymerizable monomer to have two to four groups containing a polymerizable unsaturated double bond.

The polymerizable monomer having a (meth)acrylic group is not particularly limited, and examples thereof 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, trimethylolpropane triacrylate, trimethylolpropane triacrylate, and trimethylolpropane diacrylate. Examples of the acryloyloxyethyl isocyanurate include acryloyloxyethyl isocyanurate, ...
Among these, preferred polymerizable monomers are diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and tetraethylene glycol dimethacrylate.

When the resin composition of the present disclosure contains a polymerizable monomer, the proportion of the polymerizable monomer having a (meth)acrylic group in the total amount of polymerizable monomers 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, from the viewpoint of the physical properties of the cured film.

Polymerizable monomers other than those having a (meth)acrylic group are not particularly limited, and examples include styrene, divinylbenzene, 4-vinyltoluene, 4-vinylpyridine, N-vinylpyrrolidone, methylenebisacrylamide, N,N-dimethylacrylamide, and N-methylolacrylamide.

When the resin composition of the present disclosure contains a polymerizable monomer, the content of the polymerizable monomer is not particularly limited, and is preferably 1 to 50 parts by mass relative to 100 parts by mass of the polyimide precursor, and from the viewpoint of the thermal properties of the cured film, is more preferably 5 to 50 parts by mass, and even more preferably 5 to 40 parts by mass.

(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.

Examples of photopolymerization initiators include compounds represented by the following general formula (9A), compounds represented by the following general formula (9B), compounds represented by the following general formula (10A), and compounds 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 the general formula (10A) is the compound represented by the following formula (10A-1), which 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 is a compound 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 0.5 to 10 parts by mass, per 100 parts by mass of the unsaturated polyimide precursor.

(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 2.0 parts by mass, and more preferably 0.2 to 1.0 parts by mass, per 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 benzene-1,4-bis(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 compounds 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.

(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. 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-butyl phenol), 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-dimethyl benzyl)-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] 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.

The photosensitive resin composition of the present disclosure may further contain a thermal polymerization initiator, an imidization accelerator, an antioxidant, an ultraviolet absorber, a surfactant, a leveling agent, etc.

(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 an imidization accelerator from the viewpoint of promoting the imidization reaction.

Specific examples of the imidization accelerator include N-phenyldiethanolamine, 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, and 4-aminoacetophenone, among which N-methylaniline, N-ethylaniline, N,N'-dimethylaniline, N-phenylethanolamine, 4-phenylmorpholine, and 2,2'-(4-methylphenylimino)diethanol are preferred. The nitrogen-containing compounds may be used alone or in combination of two or more.

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

(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.

(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.

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 ultraviolet absorbent selected from the group consisting of benzotriazole-based compounds, benzophenone-based compounds, azobenzene-based compounds, and polyphenol-based compounds.

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 the 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, relative to 100 parts by mass of the unsaturated polyimide precursor.

The photosensitive resin composition of the present disclosure may further contain inevitable impurities.
In the photosensitive resin composition of the present disclosure, the total amount of the unsaturated polyimide precursor, the nitrogen-containing compound, the polymerizable monomer, the photopolymerization initiator, the sensitizer, the coupling agent, and the solvent may be 80% by mass or more, 90% by mass or more, or 95% by mass or more.

<Cured Product>
The cured product of the present disclosure can be obtained by curing the 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.

<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 5 μm to 100 μm, more preferably 6 μm to 50 μm, and even more preferably 7 μm to 30 μm.

The pattern exposure is performed by exposing the material to 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 with a rinsing solution may be carried out.
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 corrodes 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.

[Examples 1A to 3A and Comparative Example 1A]
Each component shown in Table 1 was mixed in the amount shown in Table 1 to prepare a homogeneous solution. The resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter having a pore size of 1 μm to obtain photosensitive resin compositions of Examples 1A to 3A and Comparative Example 1A.
The amount of each component in Table 1 is based on parts by mass. In Table 1, "-" means that the corresponding component is not contained.
Details of each component listed in Table 1 are as follows.

Synthesis of Unsaturated Polyimide Precursor (Polymer I)
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 dropped, and then stirred at 30°C for 3 hours. Next, 59.7g (284mmol) of TFAA (trifluoroacetic anhydride, Fujifilm Wako Pure Chemical Industries, Ltd.) was dropped at 30°C. After stirring at 45°C for 2 hours, 0.08g (0.74mmol) of BQ (benzoquinone, Fujifilm Wako Pure Chemical Industries, Ltd.) was added, and 40.4g (310mmol) of HEMA was dropped. After stirring for 15 hours, the mixture was cooled to room temperature. The reaction solution was poured into purified water, and the precipitate was collected, washed with purified water, and then dried under reduced pressure to obtain polymer I as an unsaturated polyimide precursor.
The weight average molecular weight (Mw) of Polymer I was 22,100.

The measurement conditions for the weight average molecular weight of the polymer calculated as standard polystyrene by the GPC method are as follows. The measurement was performed using 1 mL of a solution of a solvent [tetrahydrofuran (THF)/dimethylformamide (DMF)=1/1 (volume ratio)] per 0.5 mg of the polymer.
Measurement equipment: Detector, L4000UV manufactured by Hitachi, Ltd.
Pump: Hitachi L6000
Shimadzu Corporation C-R4A Chromatopac
Measurement conditions: Column Gelpack GL-S300MDT-5 x 2 Eluent: THF/DMF = 1/1 (volume ratio)
LiBr (0.03mol/L), _H3PO4 (0.06mol _/ L)
Flow rate: 1.0 mL/min, detector: UV 270 nm

·solvent:
I: N-methyl-2-pyrrolidone II: 3-methoxy-N,N-dimethylpropanamide Polymerizable monomer: Tetraethylene glycol dimethacrylate (TEGDMA, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Photopolymerization initiator: 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime (G-1820 (PDO), Lambson)
Sensitizer: 4,4'-bis(diethylamino)benzophenone (EMK, Merck)
Coupling agent: 3-ureidopropyltriethoxysilane ("UCT-801" manufactured by United Chemical Technology)
Nitrogen-containing compound I: Inosine (SP value: 40.6)
II: 6-azauracil (SP value: 40.9)
III: Uridine (SP value: 42.3)
IV: 1H-benzotriazole (SP value: 28.0)

(Preparation of cured film)
The above-mentioned resin composition was spin-coated on a Cu-plated wafer using a coating device Act8 (manufactured by Tokyo Electron Co., Ltd.), dried at 90°C for 100 seconds, and then dried at 100°C for 100 seconds to form a resin film. The obtained resin film was exposed to 400 mJ/ ^cm2 using a proximity exposure device MA8 (SUSS MicroTec mask aligner, broadband light: wavelength 350-450 nm). Thereafter, the film was developed with cyclopentanone using a developing device Act8. The developed resin film was heated at 250°C for 2 hours under a nitrogen atmosphere using an inert gas oven INL-60N1-S (manufactured by JTEKT Thermo Systems Co., Ltd.) to obtain a cured film (film thickness after curing: 6 μm).

(Measurement of Peel Strength)
Using SAICAS EN (manufactured by Daipla Wintes Co., Ltd.), the cured film was cut at a horizontal speed of 3.0 μm/sec and a vertical speed of 0.5 μm/sec, and when it reached the interface between the cured film and the substrate, the cutting blade was advanced only in the horizontal direction, and the average peel strength was measured from 180 seconds to 270 seconds. The results are shown in Table 1.
"A": Peel strength 0.26 kN/m or more; "B": Peel strength 0.15 kN/m or more but less than 0.26 kN/m; "C": Peel strength less than 0.15 kN/m

 

 

As shown in Table 1, the cured films obtained from the compositions of Examples 1A to 3A, which contained a specific nitrogen-containing compound, had higher peel strengths than Comparative Example 1A, which contained nitrogen-containing compound IV (1H-benzotriazole, SP value: 28.0), which is not a specific nitrogen-containing compound.

[Examples 4 to 6A]
Cured films of Examples 4A to 6A were prepared and evaluated in the same manner as in Example 1, except that the blending amount of nitrogen-containing compound I (inosine) was changed as shown in Table 2. The results are shown in Table 2.

 

As shown in Table 2, even when the amount of the specific nitrogen-containing compound was changed, the cured films obtained from the compositions of Examples 1A and 4A to 6A had superior peel strength compared to the cured film obtained from the composition of Comparative Example 1A.

[Examples 1B to 3B, Comparative Example 1B]
Cured films of Examples 1B to 3B and Comparative Example 1B were prepared and evaluated in the same manner as in Example 1A, etc., except that the unsaturated polyimide precursor was changed from Polymer I to Polymer II, and each component shown in Table 3 was blended in the blending amount shown in Table 3. The results are shown in Table 3. In Table 3, "-" means that the corresponding component was not contained.

(Synthesis of Polymer II)
In a 0.5 liter plastic bottle, 43.624 g (200 mmol) of pyromellitic dianhydride (PMDA) dried for 24 hours in a dryer at 160°C, 54.919 g (401 mmol) of 2-hydroxyethyl methacrylate, and 0.220 g of hydroquinone were dissolved in 394 g of N-methyl-2-pyrrolidone, and after adding a catalytic amount of 1,8-diazabicycloundecene, the mixture was stirred at room temperature (25°C) for 24 hours to carry out esterification, thereby obtaining a pyromellitic acid-hydroxyethyl methacrylate diester solution. This solution was used as a PMDA (HEMA) solution.

Separately, in a 0.5 liter plastic bottle, 15.5 g of 4,4'-oxydiphthalic anhydride (ODPA) that had been dried in a 160°C dryer for 24 hours, 14.1 g of 2-hydroxyethyl methacrylate, and 0.1 g of hydroquinone were dissolved in 118 g of N-methyl-2-pyrrolidone, and a catalytic amount of 1,8-diazabicycloundecene was added to prepare a mixed solution. The mixed solution was stirred at room temperature (25°C) for 48 hours and esterified to obtain a 4,4'-oxydiphthalic acid-hydroxyethyl methacrylate diester solution. This solution was designated as the ODPA (HEMA) solution.

In a 0.5 liter flask equipped with a stirrer and a thermometer, 493.2 g of PMDA (HEMA) solution and 148.1 g of ODPA (HEMA) solution were placed, and then 124.9 g of thionyl chloride was added dropwise using a dropping funnel under ice cooling so that the reaction solution temperature was kept below 10° C. At this time, the molar ratio of PMDA (HEMA) to ODPA (HEMA) was 3:1.
After the dropwise addition of thionyl chloride was completed, the reaction was carried out under ice-cooling for 2 hours to obtain a solution of acid chlorides of PMDA (HEMA) and ODPA (HEMA). Next, using a dropping funnel, a solution obtained by dissolving 80 g of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 83 g of pyridine, and 0.2 g of hydroquinone in 227 g of N-methyl-2-pyrrolidone was dropped while being careful not to allow the temperature of the reaction solution to exceed 10°C under ice-cooling. This reaction solution was dropped into distilled water, and the precipitate was collected by filtration and dried under reduced pressure to obtain polymer II as an unsaturated polyimide precursor. The weight-average molecular weight (Mw) of polymer II was 34,000.

 

As shown in Table 3, the cured films obtained from the compositions of Examples 1B to 3B had superior peel strength compared to the cured film obtained from the composition of Comparative Example 1B.

The results in Table 3 show that even if the type of unsaturated polyimide precursor is changed, the cured film obtained from the composition containing the specific nitrogen-containing compound has excellent peel strength, so it is inferred that the same effect can be obtained even if the unsaturated polyimide precursor is changed to the following polymers III to V.

Polymer III
Acid component: ODPA
Amine components: 4,4'-diaminodiphenyl ether (ODA) and m-phenylenediamine (MPD)

Polymer IV
Acid component: ODPA
Amine component: ODA

Polymer V
Acid component: 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) Amine component: ODA

[Examples 1C to 2C, Comparative Example 1C]
Cured films of Examples 1C and 2C and Comparative Example 1C were prepared and evaluated in the same manner as in Example 1A, etc., except that solvent I was changed to solvent II and each component shown in Table 4 was blended in the blending amount shown in Table 4. The results are shown in Table 4. In Table 3, "-" means that the corresponding component was not contained.

 

As shown in Table 4, even when the type of solvent was changed, the cured films obtained from the compositions of Examples 1C to 2C had superior peel strength compared to the cured film obtained from the composition of Comparative Example 1C, indicating that similar effects can be obtained with other solvents.

Reference Signs List 1 Semiconductor substrate 2 Protective film 3 First conductor layer 4 Interlayer insulating film 5 Photosensitive resin layer 6A, 6B, 6C Window 7 Second conductor layer 8 Surface protective film

Claims (9)

A photosensitive resin composition containing a polyimide precursor having a polymerizable unsaturated bond and at least one selected from the group consisting of nitrogen-containing compounds having a solubility parameter of 32 or more and a hydroxyl group, and nitrogen-containing compounds having a solubility parameter of 39 or more. The photosensitive resin composition according to claim 1, wherein the nitrogen-containing compound includes inosine. 3. 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 any one of claims 1 to 3, further comprising at least one selected from the group consisting of a polymerizable monomer, a photopolymerization initiator, a sensitizer, a coupling agent, and a solvent. 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 cured product obtained by curing the photosensitive resin composition according to any one of claims 1 to 4. The cured product according to claim 6, which is a patterned cured product. The cured product according to claim 6 or claim 7, which is used as an interlayer insulating film, a cover coat layer, or a surface protective film. An electronic component comprising the cured product according to any one of claims 6 to 8.