JP6874401B2 - An electronic device comprising a photosensitive resin composition and a resin film formed thereby. - Google Patents

Description

The present invention relates to a photosensitive resin composition, a resin film produced by the photosensitive resin composition, and an electronic device including the resin film.

So far, in the field of photosensitive resin compositions, various techniques have been developed for the purpose of improving the accuracy of resist patterns as the patterns become finer. Examples of this type of technology include the technology described in Patent Document 1. The document describes a radiation-sensitive resin composition containing a specific polymer and a specific acid generator. Then, the polymer is N- (t-butyloxycarbonylmethyl) maleimide, N- (1-methyl-1-cyclopentyloxycarbonylmethyl) maleimide, or N- (2-ethyl-2-adamantyloxycarbonylmethyl). By having a structural unit (I) which is maleimide and a structural unit (II) which is 2-norbornene, it is said that it is excellent in LWR (Line Width Rougness) performance and defect suppression property, which indicates a small amount of rattling in the line width. It is described (Patent Document 1).

Patent Document 1 describes that AIBN (azobisisobutyronitrile) is used as a radical polymerization initiator for the synthesis of the polymer (Examples 1 to 3 of Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-184458

However, as a result of the present inventor examining the heat resistance and chemical resistance of the photosensitive resin composition, the radiation-sensitive resin composition described in Patent Document 1 is further improved from the viewpoint of heat resistance and chemical resistance. It turned out that there was room for improvement. An object of the present invention is to provide a photosensitive resin composition having improved heat resistance and chemical resistance when formed into a resin film.

The present inventor has considered introducing a molecular structure that contributes to cross-linking into the molecular structure of a copolymer to improve the heat resistance and chemical resistance of the photosensitive resin composition.
Therefore, as a result of examining a conventional copolymer, the present inventor has found that it is effective to introduce a functional group that reacts with a cross-linking agent at the end of the copolymer.
As a result, it was found that reacting these functional groups with a cross-linking agent to form a cross-linked structure via the cross-linking agent contributes to the improvement of heat resistance and chemical resistance of the photosensitive resin composition. The present invention has been completed.

According to the present invention
With the copolymer represented by the following general formula (1),
With a cross-linking agent
Photosensitizer and
A positive photosensitive resin composition containing the above is provided.

（一般式（１）中、
ｌおよびｍはそれぞれ、共重合体中における、Ａ及びＢのモル含有率を示し、
ｌ＋ｍ＝１であり、０．１≦ｌ≦０．９、０．１≦ｍ≦０．９であり、
Ａは、一般式（Ａ２）により示される構造単位を含み、
Ｂは下記一般式（Ｂ１）、一般式（Ｂ２）、式（Ｂ３）、式（Ｂ４）、式（Ｂ５）または一般式（Ｂ６）により示される構造単位の１種以上を含み、
Ｘは前記架橋剤と反応する官能基を含む炭素数１以上３０以下の有機基であり、
Ｙは水素または炭素数１以上３０以下の有機基である。）

(In general formula (1),
l and m indicate the molar content of A and B in the copolymer, respectively.
l + m = 1, 0.1 ≦ l ≦ 0.9, 0.1 ≦ m ≦ 0.9,
A comprises a structure unit of displayed in accordance with one general formula (A2),
B includes one or more of the structural units represented by the following general formula (B1), general formula (B2), formula (B3), formula (B4), formula (B5) or general formula (B6).
X is an organic group having 1 to 30 carbon atoms and containing a functional group that reacts with the cross-linking agent.
Y is hydrogen or an organic group having 1 or more and 30 or less carbon atoms. )

（一般式（Ａ１）中、Ｒ_１、Ｒ_２、Ｒ_３およびＲ_４はそれぞれ独立して水素または炭素数１以上３０以下の有機基である。ただし、カルボキシル基を除く。
ａ_１は０、１または２である。）

(In the general formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms, except for the carboxyl group.
a ₁ is 0, 1 or 2. )

（一般式（Ａ２）中、Ｒ_５、Ｒ_６、Ｒ_７およびＲ_８はそれぞれ独立して水素または炭素数１以上３０以下の有機基であって、
Ｒ_５、Ｒ_６、Ｒ_７およびＲ_８に少なくとも１つのカルボキシル基を含み、
ａ_２は０、１または２である。）

(In the general formula (A2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms.
R ₅ , R ₆ , R ₇ and R ₈ contain at least one carboxyl group
a ₂ is 0, 1 or 2. )

（一般式（Ｂ１）中、Ｒ_９は、炭素数１以上３０以下の有機基である。）

(In the general formula (B1), R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

（一般式（Ｂ２）中、Ｒ_１０及びＲ_１１は、それぞれ独立して炭素数１以上３０以下の有機基である。）

(In the general formula (B2), R ₁₀ and R ₁₁ are independently organic groups having 1 or more and 30 or less carbon atoms.)

（一般式（Ｂ６）中、Ｒ_１２は炭素数１以上３０以下の有機基である。）

(In the general formula (B6), R ₁₂ is an organic group having 1 or more and 30 or less carbon atoms.)

Further, according to the present invention, a resin film made of the above-mentioned positive photosensitive resin composition is provided.

Further, according to the present invention, there is provided an electronic device including the cured film of the resin film.

According to the present invention, there is provided a photosensitive resin composition having improved heat resistance and chemical resistance when formed into a resin film.

It is sectional drawing which shows an example of the electronic apparatus which concerns on this embodiment.

Hereinafter, the present embodiment will be described with reference to the drawings as appropriate. In all drawings, similar components are designated by the same reference numerals, and the description thereof will be omitted.

The photosensitive resin composition according to the present embodiment contains a copolymer having a specific structure, a cross-linking agent, and a photosensitive agent.

In the field of photosensitive resin compositions that form resin films used in electronic devices, photosensitive resin compositions are required to have various properties. For example, an electronic device using a resin film as a rewiring layer is required to improve the heat resistance and chemical resistance of the rewiring layer from the viewpoint of improving the reliability of the electronic device. Therefore, the photosensitive resin film that forms such a resin film is required to have improved heat resistance and chemical resistance.

Here, as the copolymer used in the photosensitive resin composition, one or more kinds selected from the group consisting of a structural unit derived from a norbornene-type monomer and a group consisting of maleic anhydride, maleic anhydride derivative, maleimide and maleimide derivative. There are copolymers containing structural units. The present inventor investigated the molecular structure of the copolymer in order to further improve the heat resistance and chemical resistance of the photosensitive resin composition containing the copolymer.
First, the present inventor considered introducing a carboxyl group into the side chain of a structural unit derived from some norbornene-type monomers. That is, it was considered that the copolymer contains a structural unit derived from a norbornene-type monomer having a carboxyl group in the side chain. Then, in a photosensitive resin composition containing the above-mentioned copolymer, a cross-linking agent, and a photosensitive agent, an attempt was made to react the carboxyl group of the above-mentioned copolymer with the cross-linking agent to form a cross-linked structure. It was speculated that by forming such a crosslinked structure, the crosslinked density in the photosensitive resin composition could be increased, and the heat resistance and chemical resistance could be improved.
However, in the copolymer, the heat resistance and chemical resistance of the photosensitive resin composition are still insufficient with respect to the required level only by forming a crosslinked structure in the side chain of the structural unit derived from the norbornene type monomer. Met. Although the detailed mechanism is not clear, it is speculated that the formation of a crosslinked structure in the side chain of the structural unit derived from the norbornene-type monomer causes steric hindrance of the molecular orbital derived from the norbornene-type structure. As a result, it is considered that the molecular chain of the copolymer is not properly bound by the crosslinked structure from the viewpoint of improving heat resistance and chemical resistance.
Therefore, the present inventor further investigated the molecular structure of the above-mentioned copolymer, and found that heat resistance and chemical resistance can be improved by providing a functional group having active hydrogen at the end of the copolymer.

The photosensitive resin composition according to the present embodiment contains a copolymer, a cross-linking agent, and a photosensitizer, wherein the end of the copolymer contains a functional group that reacts with the cross-linking agent. Further, the copolymer contains a structural unit derived from a norbornene-type monomer and one or more structural units selected from the group consisting of maleic anhydride, maleic anhydride derivative, maleimide and maleimide derivative.
The reason why the heat resistance and chemical resistance are improved in the photosensitive resin composition according to the present embodiment is presumed as follows, although the detailed mechanism is not clear. It is presumed that the functional group at the end of the copolymer reacts with the cross-linking agent to form a cross-linked structure while alleviating the steric hindrance caused by the norbornene-type structural unit of the copolymer. As a result, the molecular chains of the copolymer are tightly bound. Therefore, the micro-Brownian motion of the molecular chain of the copolymer is suppressed, and the heat resistance of the photosensitive resin composition is improved. Further, the densely formed crosslinked structure prevents molecules of chemicals such as a solvent from entering the copolymer, and reduces the reactivity between the photosensitive resin composition and the chemicals. From the above, it is presumed that the photosensitive resin composition of the present embodiment can improve heat resistance and chemical resistance.

Hereinafter, each component of the photosensitive resin composition of the present embodiment will be described.

(Copolymer)
First, the copolymer according to this embodiment will be described.
The copolymer according to this embodiment is represented by the following general formula (1).

（一般式（１）中、
ｌおよびｍはそれぞれ、共重合体中における、Ａ及びＢのモル含有率を示し、
ｌ＋ｍ＝１であり、
Ａは下記一般式（Ａ１）または一般式（Ａ２）により示される構造単位の１種以上を含み、
Ｂは下記一般式（Ｂ１）、一般式（Ｂ２）、式（Ｂ３）、式（Ｂ４）、式（Ｂ５）または一般式（Ｂ６）により示される構造単位の１種以上を含み、
Ｘは前記架橋剤と反応する官能基を含む炭素数１以上３０以下の有機基であり、
Ｙは水素または炭素数１以上３０以下の有機基である。）

(In general formula (1),
l and m indicate the molar content of A and B in the copolymer, respectively.
l + m = 1,
A includes one or more of the structural units represented by the following general formula (A1) or general formula (A2).
B includes one or more of the structural units represented by the following general formula (B1), general formula (B2), formula (B3), formula (B4), formula (B5) or general formula (B6).
X is an organic group having 1 to 30 carbon atoms and containing a functional group that reacts with the cross-linking agent.
Y is hydrogen or an organic group having 1 or more and 30 or less carbon atoms. )

The arrangement of the above copolymers is not limited, and random copolymers, alternating copolymers, block copolymers, periodic copolymers, and the like can be selected.

The composition ratio of the structural unit of A and the structural unit of B in the copolymer will be described. When the molar content (mol%) of the structural unit of A in the copolymer is l and the molar content (mol%) of the structural unit of B is m, l + m = 1, for example, a numerical value of l. The range is preferably 0.1 ≦ l ≦ 0.9. Further, the numerical range of m is preferably 0.1 ≦ m ≦ 0.9.

In the copolymer represented by the above general formula (1), A is a structural unit derived from a norbornene-type monomer having no carboxyl group in the side chain represented by the following general formula (A1), or the following general formula. It contains a structural unit derived from a norbornene-type monomer having at least one carboxyl group in _{R 5 to} R _{8 represented} by (A2).

A preferably contains a structural unit represented by the following general formula (A2). Thus, it is possible to react with the carboxyl group of the side chain R ₅ to R ₈ of the general formula (A2), and a crosslinking agent. Therefore, in addition to the crosslinked structure at the end of the copolymer, a crosslinked structure is formed via the carboxyl group of the side chain. As a result, the crosslink density can be improved while alleviating steric hindrance and forming an appropriate crosslink structure. Therefore, the heat resistance and chemical resistance of the photosensitive resin composition can be improved.
Further, it is more preferable that A contains a structural unit represented by the following general formula (A1) and a structural unit represented by the following general formula (A2). Thereby, the acid value of the copolymer can be controlled, and any alkali solubility can be realized according to the characteristics of the desired copolymer or photosensitive resin composition.

（一般式（Ａ１）中、Ｒ_１、Ｒ_２、Ｒ_３およびＲ_４はそれぞれ独立して水素または炭素数１以上３０以下の有機基である。ただし、カルボキシル基を除く。
ａ_１は０、１または２である。）

(In the general formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms, except for the carboxyl group.
a ₁ is 0, 1 or 2. )

（一般式（Ａ２）中、Ｒ_５、Ｒ_６、Ｒ_７およびＲ_８はそれぞれ独立して水素または炭素数１以上３０以下の有機基であって、
Ｒ_５、Ｒ_６、Ｒ_７およびＲ_８に少なくとも１つのカルボキシル基を含み、
ａ_２は０、１または２である。）

(In the general formula (A2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms.
R ₅ , R ₆ , R ₇ and R ₈ contain at least one carboxyl group
a ₂ is 0, 1 or 2. )

In the present embodiment, the hydrogen or the organic group having 1 or more and 30 or less carbon atoms constituting _{R 1 to} R ₄ in the general formula (A1) _{and R 5 to} R ₈ in the general formula (A2) is Each independently may contain one or more atoms selected from O, N, S, P and Si in its structure.
Further, in the present embodiment, none of the organic groups constituting _{R 1} , R ₂ , R ₃ and R _{4 can have an acidic functional group.} This makes it possible to easily control the acid value in the copolymer.

_{In the present embodiment, R 1 to} R ₄ in the general formula (A1) _{and R 5 to} R ₈ in the general formula (A2) are independently hydrogen or carbon number 1 or more and 30 or less. It is an organic group, preferably hydrogen or an organic group having 1 or more and 15 or less carbon atoms, and more preferably hydrogen or an organic group having 1 or more and 10 or less carbon atoms.

_{In the present embodiment, examples of the organic groups constituting R 1 to} R ₄ in the general formula (A1) _{and R 5 to} R ₈ in the general formula (A2) include an alkyl group and an alkenyl group. Examples thereof include an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkalil group, a cycloalkyl group, an alkoxy group and a heterocyclic group.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group and a heptyl group. Examples include octyl group, nonyl group, and decyl group. Examples of the alkenyl group include an allyl group, a pentenyl group, and a vinyl group. Examples of the alkynyl group include an ethynyl group. Examples of the alkylidene group include a methylidene group and an ethylidene group. Examples of the aryl group include a tolyl group, a xsilyl group, a phenyl group, a naphthyl group, and an anthrasenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the alkaline group include a tolyl group and a xsilyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an s-butoxy group, an isobutoxy group and a t-butoxy group, an n-pentyloxy group and a neopentyloxy group. , N-hexyloxy group. Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

_{In the present embodiment, a 1} in the general formula (A1) _{and a 2} in the general formula (A2) are independently 0, 1 or 2, and even if they are 0 or 1. Well, it may be 0.

In the present embodiment, in the general formula _(A1), an organic group constituting R _1, R 2, _{R 3} and _{R 4} may include, for example, a carboxylic acid anhydride group. In this case, it is preferable that R ₁ or R ₂ and R ₃ or R ₄ are bonded via a carboxylic acid anhydride group to form a cyclic structure via the carboxylic acid anhydride group.

When the general formula (A1) has a cyclic structure via the carboxylic acid anhydride described above, a carboxyl group is formed by opening a part of the cyclic structure by hydrolysis to form a carboxyl group, and the general formula (A2) is described. ). Thereby, the amount of carboxyl groups in the side chain of the structural unit derived from the norbornene-type monomer of the copolymer can be adjusted. Therefore, a more suitable crosslinked structure can be formed.
The specific method of hydrolysis is not limited, and a conventionally known method can be used depending on the cyclic structure via the carboxylic acid anhydride group. For example, a method of adding alcohol such as methanol or ethanol or water to a solution containing a copolymer and heating the solution can be mentioned.

In the present embodiment, in the above general formula (A2), R ₅ , R ₆ , R ₇ and R ₈ contain at least one carboxyl group. As a result, the active hydrogen of the carboxyl group reacts with the cross-linking agent to further form a cross-linked structure in the copolymer. That is, in the copolymer, a crosslinked structure is formed in the side chain of the structural unit derived from the norbornene-type monomer which is the main chain. Thereby, the crosslink density can be improved. Therefore, heat resistance and chemical resistance can be further improved.

_{Further, in the present embodiment, the number of carboxyl groups contained in R 5} , R ₆ , R ₇ and R ₈ in the above general formula (A2) is not limited, and at least one carboxyl group may be contained. It may contain two or more carboxyl groups. By appropriately adjusting the number of carboxyl groups, an arbitrary crosslinked structure can be formed, and by adjusting the acid value, arbitrary alkali solubility can be realized.

Further, in the copolymer represented by the above general formula (1), B is the following general formula (B1), the following general formula (B2), the following formula (B3), the following formula (B4), and the following formula (B5). Alternatively, it includes one or more structural units represented by the following general formula (B6).

（一般式（Ｂ１）中、Ｒ_９は、炭素数１以上３０以下の有機基である。）

(In the general formula (B1), R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

（一般式（Ｂ２）中、Ｒ_１０及びＲ_１１は、それぞれ独立して炭素数１以上３０以下の有機基である。）

(In the general formula (B2), R ₁₀ and R ₁₁ are independently organic groups having 1 or more and 30 or less carbon atoms.)

（一般式（Ｂ６）中、Ｒ_１２は、炭素数１以上３０以下の有機基である。）

(In the general formula (B6), R ₁₂ is an organic group having 1 or more and 30 or less carbon atoms.)

B preferably contains the structural unit represented by the above formula (B5) or the above general formula (B6), and B more preferably contains the structural unit represented by the above general formula (B6). As a result, heat resistance and chemical resistance can be improved, and sensitivity can be maintained.

_{The organic groups having 1 to 30 carbon atoms constituting R 9 to} R ₁₂ in the general formula (B1), the general formula (B2) and the general formula (B6) have O, N, S and P in their structures. And one or more atoms selected from Si may be included.
Further, in the present embodiment _{, none of the organic groups constituting R 9 to} R ₁₂ can have an acidic functional group such as a carboxyl group. This makes it possible to easily control the acid value in the copolymer.

_{In the present embodiment, R 9 to} R ₁₂ in the general formula (B1), the general formula (B2) and the general formula (B6) are independently organic groups having 1 to 30 carbon atoms and carbon. It is preferably an organic group having a number of 1 or more and 15 or less, more preferably an organic group having 1 or more and 10 or less carbon atoms, and further preferably an organic group having 1 or more and 6 or less carbon atoms.

_{In the present embodiment, examples of the organic group constituting R 9 to} R ₁₂ in the general formula (B1), the general formula (B2) and the general formula (B6) include an alkyl group, an alkenyl group, an alkynyl group and an alkylidene. Examples include groups, aryl groups, aralkyl groups, alkaline groups, cycloalkyl groups, alkoxy groups and heterocyclic groups.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group and a heptyl group. Examples include octyl group, nonyl group, and decyl group. Examples of the alkenyl group include an allyl group, a pentenyl group, and a vinyl group. Examples of the alkynyl group include an ethynyl group. Examples of the alkylidene group include a methylidene group and an ethylidene group. Examples of the aryl group include a tolyl group, a xsilyl group, a phenyl group, a naphthyl group, and an anthrasenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the alkaline group include a tolyl group and a xsilyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an s-butoxy group, an isobutoxy group and a t-butoxy group, an n-pentyloxy group and a neopentyloxy group. , N-hexyloxy group. Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

In the copolymer represented by the general formula (1), X is an organic group containing a functional group that reacts with a cross-linking agent. Thereby, a crosslinked structure can be formed at at least one end of the copolymer.

In the copolymer represented by the general formula (1), X may be an organic group having 1 or more and 30 or less carbon atoms including a functional group that reacts with a cross-linking agent, and an organic group having 1 or more and 15 or less carbon atoms. It is more preferably an organic group having 1 or more and 10 or less carbon atoms, further preferably an organic group having 1 or more and 8 or less carbon atoms, and an organic group having 1 or more and 7 or less carbon atoms. Is particularly preferable.

The functional group that reacts with the cross-linking agent contained in X is not limited, but preferably contains active hydrogen. This makes it possible for the functional group of X to undergo a cross-linking reaction with the cross-linking agent to form a cross-linked structure without impairing the performance of the photosensitive resin composition.
The functional group containing active hydrogen contained in X is preferably a hydrophilic functional group. As a result, the reactivity with the cross-linking agent can be appropriately exhibited. Therefore, a suitable crosslinked structure can be formed.
Specific examples of the hydrophilic functional group containing active hydrogen include a carboxyl group; an amino group such as a primary amino group and a secondary amino group; a hydroxyl group; a nitrogen-containing heterocyclic group such as an imidazole group and an imidazoline group; an ester. Examples thereof include functional groups that form acidic groups by hydrolysis of groups, amide groups and the like. Among these, one or more types can be included.
Among these, it is preferable to contain at least one selected from the group consisting of a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an imidazoline group, an ester group and an amide group, and preferably contains a carboxyl group and a primary amino group. And more preferably include one or more selected from the group consisting of secondary amino groups. This makes it possible to cause a cross-linking reaction with the cross-linking agent while maintaining the performance as the photosensitive resin composition. Further, when X contains a carboxyl group as a functional group that reacts with the cross-linking agent, the reactivity between the copolymer and the cross-linking agent can be adjusted. This is preferable in that an appropriate crosslinked structure can be produced and unreacted active hydrogen is not generated.

Here, X may contain a structural unit derived from a radical polymerization initiator, or may be a structural unit derived from a radical polymerization initiator. This is because when a radical polymerization initiator is used as the polymerization initiator when synthesizing the copolymer represented by the general formula (1), X can be formed from the structure of the radical polymerization initiator. Is. Thereby, by selecting an arbitrary radical polymerization initiator, a copolymer having an arbitrary structure as X can be synthesized.
The fact that X contains a structural unit derived from a radical polymerization initiator ^{can be identified by, for example, 1} H-NMR measurement spectrum data.

The structure of X derived from the radical polymerization initiator is not limited, and specific examples thereof include the following formulas (X1) to (X5).
The structure derived from the radical polymerization initiator in X is one or more represented by the group consisting of the following formula (X1), formula (X2), formula (X3), formula (X4) and formula (X5). Is preferably included. This is because the structures of the following formulas (X1) to (X5) contribute to the cross-linking, so that the steric hindrance can be alleviated more effectively, and thus a stronger cross-linked structure can be formed. Guessed.
Among these, it is more preferable to include the following formula (X1) or formula (X2). Thereby, heat resistance and chemical resistance can be further improved.

The structure represented by the above formula (X1) can be formed, for example, by cleaving 4,4'-azobis (4-cyanovaleric acid), which is a radical polymerization initiator. The structure represented by the above formula (X2) is formed, for example, by cleaving 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], which is a radical polymerization initiator. Can be done. The structure represented by the above formula (X3) can be formed, for example, by cleaving 2,2'-azobis [N- (2-carboxyethyl) -2-methyl], which is a radical polymerization initiator. .. The structure represented by the above formula (X4) can be formed, for example, by cleaving 2,2'-azobis (2-methylpropion amidine) which is a radical polymerization initiator. The structure represented by the above formula (X5) can be formed, for example, by cleaving 2,2'-azobis [2- (2-imidazolin-2-yl) propane] which is a radical polymerization initiator. ..

In the copolymer represented by the general formula (1), Y is hydrogen or an organic group having 1 or more and 30 or less carbon atoms, preferably hydrogen or an organic group having 1 or more and 15 or less carbon atoms, and hydrogen or carbon. It is more preferably an organic group having a number of 1 or more and 10 or less, further preferably hydrogen or an organic group having 1 or more and 6 or less carbon atoms, and particularly preferably a hydrogen or an organic group having 1 or more and 4 or less carbon atoms. ..

Y may include a structural unit derived from a radical polymerization initiator, hydrogen, or a structural unit derived from a chain transfer agent, and is derived from a structural unit derived from a radical polymerization initiator, hydrogen, or a chain transfer agent. It may be a structural unit.
This is because when a radical polymerization initiator is used as the polymerization initiator when synthesizing the copolymer represented by the above general formula (1), Y is formed by a termination reaction of the radical chain reaction which is a polymerization reaction of the copolymer. Because it can be done.

The termination reaction of the radical chain reaction will be described. The radical chain reaction termination reaction occurs at the growth end of the copolymer in the radical chain reaction, that is, at the radical portion of the growing copolymer, by a reaction mechanism called recombination termination or disproportionation termination. In the radical chain reaction, recombination termination and disproportionation termination compete with each other.

The rebinding arrest is a termination reaction in which the radicals of the two growing copolymers react with each other. As a result, for example, when the copolymer in which the n-mer grows and the copolymer in which the m-mer grows cause recombination arrest, the copolymer of n + m-mer is generated and the radical chain reaction is stopped. .. The X and Y of the copolymer that has undergone recombination termination contain structural units derived from the radical polymerization initiator. That is, in the copolymer that has undergone recombination termination, the structural unit derived from the radical polymerization initiator in Y is the same as the structural unit derived from the radical polymerization initiator of X described above.

The disproportionation termination is a termination reaction in which radicals of a growing copolymer are transferred to another growing copolymer or a molecule such as a solvent. As a result, in the copolymer that has undergone disproportionation termination, X is a structural unit derived from the above-mentioned radical polymerization initiator, and Y is hydrogen.

Further, when a chain transfer agent is used at the time of synthesizing the copolymer, a chain transfer reaction occurs in the radical chain reaction which is a polymerization reaction. In the copolymer that has undergone the chain transfer reaction, X of the copolymer is a structural unit derived from the above-mentioned radical polymerization initiator, and Y is a structural unit derived from the chain transfer agent.
The structure of Y derived from the chain transfer agent can be confirmed, for example, by the relationship between the amount of the chain transfer agent added and the weight average molecular weight.

In the copolymer represented by the general formula (1), Y may contain a functional group that reacts with a cross-linking agent. When Y contains a functional group that reacts with a cross-linking agent, a cross-linked structure can be formed at both ends of the copolymer. A copolymer that forms a crosslinked structure at both ends can form a stronger crosslinked structure than a copolymer that contains a functional group that reacts with a crosslinker at one end. Thereby, heat resistance and chemical resistance can be improved.

The functional group that reacts with the cross-linking agent contained in Y is not limited, but is preferably a functional group containing active hydrogen. As a result, when X contains a functional group containing active hydrogen, the functional group and the cross-linking agent that react with the cross-linking agent contained in Y undergo a cross-linking reaction by the same reaction mechanism as the reaction caused by the functional group and the cross-linking agent of X. Wake up. Therefore, uniform reactivity can be generated at both ends of the copolymer, and the crosslinked structure can be formed more firmly.

The functional group containing the active hydrogen of Y is preferably a hydrophilic functional group. Thereby, the reactivity with the cross-linking agent can be appropriately exhibited. Therefore, a suitable crosslinked structure can be formed.
Specific examples of the hydrophilic functional group containing active hydrogen include a carboxyl group; an amino group such as a primary amino group and a secondary amino group; a hydroxyl group; a nitrogen-containing heterocyclic group such as an imidazole group and an imidazoline group; an ester group. Examples thereof include functional groups that form acidic groups by hydrolysis such as amide groups. Among these, one or more types can be included.
Among these, it is preferable to contain at least one selected from the group consisting of a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an imidazoline group, an ester group and an amide group, and preferably contains a carboxyl group and a primary amino group. And more preferably include one or more selected from the group consisting of secondary amino groups. This makes it possible to cause a cross-linking reaction with the cross-linking agent without impairing the performance of the photosensitive resin composition. Further, when Y contains a carboxyl group as a functional group that reacts with the cross-linking agent, the reactivity between the copolymer and the cross-linking agent can be adjusted. As a result, an appropriate crosslinked structure can be produced, and there is no inconvenience in that unreacted active hydrogen is not generated.

It is preferable that the functional group that reacts with the cross-linking agent contained in X and the functional group that reacts with the cross-linking agent contained in Y are the same. As a result, the reactivity at both ends of the copolymer can be made uniform and an appropriate crosslinked structure can be formed.

The structural unit derived from the radical polymerization initiator of Y is not limited, but may be the same as the structural unit derived from the radical polymerization initiator of X.

The structure of Y derived from the chain transfer agent is not limited, but is represented by a group consisting of the following formulas (Y1), (Y2), (Y3), (Y4) and (Y5). It preferably contains one or more structural units. Thereby, heat resistance and chemical resistance can be improved. This is because the structural units of the following formulas (Y1) to (Y5) contribute to cross-linking, so that steric hindrance can be alleviated more effectively, and a stronger cross-linked structure can be formed. It is presumed.

The structures represented by the above formulas (Y1) and (Y2) can be formed, for example, by using a chain transfer agent 2-{[(2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propionic acid. The structure represented by the above formula (Y3) can be formed by using, for example, trithiocarbonate bis {4- [ethyl- (2-hydroxyethyl) carbamoyl] benzyl} which is a chain transfer agent. The structures represented by the above formulas (Y4) and (Y5) can be formed, for example, by using a chain transfer agent 4-[(2-carboxyethyl sulfanylthiocarbonyl) sulfanyl] -4-cyanopentanoic acid. ..

Y may include a structure derived from a chain transfer agent. This is because when the copolymer represented by the general formula (1) is synthesized, the structure of Y can be formed from the structure of the chain transfer agent.

It is preferable that X and Y each contain a carboxyl group as a functional group that reacts with the cross-linking agent. As a result, although the detailed mechanism is not clear, the reactivity with the cross-linking agent can be made similar at both ends of the copolymer, and a denser cross-linked structure can be formed. ..

From the viewpoint of forming an appropriate crosslinked structure, the lower limit of the Mw (weight average molecular weight) of the copolymer according to the present embodiment may be, for example, 2000 or more, preferably 2500 or more, and 3000 or more. Further, from the same viewpoint as the lower limit value, the upper limit value of Mw of the copolymer may be, for example, 12000 or less, preferably 11000 or less, and further preferably 10000 or less.
Further, the upper limit of the polydispersity of the copolymer according to the present embodiment makes the physical properties of each molecular chain of the copolymer uniform, and the shape of the resin film made of the photosensitive resin composition containing the copolymer is good. For example, it is preferably 2.5 or less, preferably 2.2 or less, more preferably 2.0 or less, and even more preferably 1.5 or less. Further, from the same viewpoint as the upper limit value, the lower limit value of the polydispersity of the copolymer is preferably 1.0 or more, for example.
The degree of polydispersity is represented by Mw (weight average molecular weight) / Mn (number average molecular weight), and means the degree of dispersion indicating the width of the molecular weight distribution.

For the weight average molecular weight (Mw), the number average molecular weight (Mn), and the molecular weight distribution (Mw / Mn), polystyrene-equivalent values obtained from, for example, a calibration curve of standard polystyrene (PS) obtained by GPC measurement are used. The measurement conditions are as follows, for example.
Tosoh gel permeation chromatography device HLC-8320GPC
Column: Tosoh TSK-GEL Supermultipore HZ-M
Detector: RI detector for liquid chromatogram Measurement temperature: 40 ° C
Solvent: THF
Sample concentration: 2.0 mg / ml

In the copolymer according to the present embodiment, for example, in the molecular weight distribution curve obtained by GPC (Gel Permeation Chromatography), the peak area at a molecular weight of 1000 or less may be 1% or less of the whole.
As described above, by setting the ratio of the peak area of the molecular weight distribution curve obtained by GPC to the molecular weight of 1000 or less within the above range, the pattern shape of the film made of the resin composition containing the copolymer can be improved. it can. Therefore, it is possible to improve the operation reliability of a liquid crystal display device and a solid-state image sensor having the film as a permanent film.
The lower limit of the amount of the low molecular weight component in the copolymer is not limited. However, the copolymer according to the present embodiment allows a case where the peak area at a molecular weight of 1000 or less is 0.01% or more of the whole in the molecular weight distribution curve obtained by GPC.
The amount of the low molecular weight component in the copolymer is calculated from the ratio of the total area of the components corresponding to the molecular weight of 1000 or less to the total area of the molecular weight distribution based on the data on the molecular weight obtained by, for example, GPC measurement. ..

(Method for producing copolymer)
The copolymer according to this embodiment is produced, for example, as follows.
First, the copolymer is polymerized by the polymerization step (S1). Next, the low molecular weight component removal step (S2) removes the low molecular weight component to obtain a copolymer containing the copolymer as a main component.
Further, when the monomer B contains maleic anhydride, a ring-opening step (S3) and a washing step (S4) are performed after the polymerization step (S1) and before the low molecular weight component removing step (S2). May be good. In the ring-opening step (S3), a part of the maleic anhydride unit in the copolymer is opened. In addition, the washing step (S4) cleans the metal alkoxide as the base used for the ring opening in the ring opening step (S3), or the residual metal component derived from the hydroxide of the alkali metal as the alcohol and the base.
The details of each step will be described below.

(Polymerization step (S1))
First, the polymerization step of polymerizing the copolymer will be described.
First, a norbornene-type monomer and one or more selected from the group consisting of maleic anhydride, maleimide and maleimide derivatives are prepared. Further, one type of norbornene type monomer may be prepared, or two or more types may be prepared.
In the copolymer represented by the general formula (1), A is a structural unit derived from the norbornene-type monomer. Further, B is a structural unit derived from one or more selected from the group consisting of maleic anhydride, maleimide and maleimide derivatives.

As the monomer A, the monomer A1 represented by the following formula (2) or the monomer A2 represented by the following formula (3) can be used. The monomer A may contain a monomer A1 or a monomer A2, or may contain a monomer A1 and a monomer A2.
In Formula _(2), R 1 ~R ₄ may be the same as _R 1 to R ₄ in the general formula (A1) described above. Further, in the following formula (3) _may be R 5 to R ₈ are the same as _R 5 to R ₈ of general formula (A2) as described above.

（式（２）中、Ｒ_１、Ｒ_２、Ｒ_３、Ｒ_４およびａ_１は、上記一般式（Ａ１）と同様である。）

(In the formula (2), R ₁ , R ₂ , R ₃ , R ₄ and a ₁ are the same as the above general formula (A1).)

Specific examples of the monomer A1 represented by the above formula (2) include norbornene, norbornene, bicyclo [2.2.1] -hept-2-ene (common name: 2-norbornene), and 5-methyl-2. -Norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-allyl-2-norbornene, 5- (2-propenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5-ethynyl-2-norbornene, 5-benzyl-2-norbornene, 5-phenethyl-2-norbornene, 2-acetyl-5 -Norbornene, methyl 5-norbornene-2-carboxylate, 5-norbornene-2,3-dicarboxylic acid anhydride and the like can be mentioned.
As the monomer A1 represented by the above formula (2), one or more of these can be used.

（式（３）中、Ｒ_５、Ｒ_６、Ｒ_７、Ｒ_８及びａ_２は上記一般式（Ａ２）と同様である。）

(In the formula (3), R ₅ , R ₆ , R _7, R ₈ and a ₂ are the same as the above general formula (A2).)

Specific examples of the monomer A2 represented by the above formula (3) include 5-norbornene-2-carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid monomethyl and Examples thereof include monoethyl 5-norbornene-2,3-dicarboxylic acid. As the monomer A2, one or more of these can be used. Above all, it is preferable to use 5-norbornene-2-carboxylic acid from the viewpoint of forming a crosslinked structure and controlling alkali solubility.

Monomer B is one or more monomers selected from the group consisting of maleic anhydride, maleimide and the maleimide derivative represented by the following formula (4), and is maleimide and the maleimide derivative represented by the following formula (4). It is preferably one or more monomers selected from the group consisting of, and more preferably a maleimide derivative represented by the following formula (4). By using the maleimide derivative represented by the following formula (4), heat resistance and chemical resistance can be improved.
Further, in the following formula _{(4), R 12} may be the same as _{R 12} in formula (B6).

（Ｒ_１２は、炭素数１以上３０以下の有機基である。）

(R ₁₂ is an organic group having 1 or more and 30 or less carbon atoms.)

Examples of the maleimide derivative represented by the above formula (4) include N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (4-aminophenyl) maleimide, N-benzylmaleimide, and N-tert-butyl. Included are maleimide, N-ethylmaleimide, N- (2-hydroxyethyl) maleimide, N-methoxycarbonylmaleimide, 3-maleimide propionic acid, 4-maleimide butyric acid and 6-maleimidohexanoic acid. Among these, it is preferable to use N-methylmaleimide. Thereby, heat resistance and chemical resistance can be improved.

Next, the monomer A and the monomer B are addition-polymerized to synthesize a copolymer.
It should be noted that the use of one type or two or more types of monomers as the monomer A and the monomer B is not limited.
The method of addition polymerization is not limited, but in the present embodiment, a copolymer is synthesized by radical polymerization using a radical polymerization initiator.
By addition polymerization using a radical polymerization initiator, a copolymer having a structural unit derived from monomer A and a structural unit derived from monomer B and having a terminal derived from the radical polymerization initiator is synthesized. Can be done.
Here, the structural unit derived from the monomer A1 is the above general formula (A1). The structural unit derived from the monomer A2 is the above general formula (A2).
Further, by using maleic anhydride, maleimide, and the maleimide derivative represented by the above formula (4) as the monomer B, the structural units of the above formula (B3), the above formula (B5), and the above general formula (B6), respectively. A copolymer having the above can be obtained.

The molar ratio of monomer A to monomer B in the copolymer is preferably 0.5: 1 to 1: 0.5. The above 0.5: 1 to 1: 0.5 includes 0.5: 1 and 1: 0.5. Among these, the molar ratio is preferably 1: 1 from the viewpoint of improving the controllability of the molecular structure.
Addition polymerization is allowed to proceed by dissolving the monomer A, the monomer B, and the radical polymerization initiator in a solvent and then heating for a predetermined time. The heating temperature is, for example, 50 ° C. or higher and 80 ° C. or lower, and the heating time is 10 hours or longer and 20 hours or lower.
In addition, the addition polymerization does not limit the addition of additives such as chain transfer agents according to the performance required for the photosensitive resin composition. It is preferable to control the terminal structure of the copolymer by adding a chain transfer agent and introduce a functional group that reacts with the cross-linking agent into the terminal of the copolymer.

The radical polymerization initiator is not limited as long as it introduces a functional group that reacts with a cross-linking agent into X, which is one of the ends of the copolymer, and an azo compound or a peroxide can be used. Among these, it is preferable to use an azo compound.
Specifically, the azo compound has a carboxyl group such as 4,4'-azobis (4-cyanovaleric acid) and 2,2'-azobis [N- (2-carboxyethyl) -2-methyl]. Radical polymerization initiator; Radical polymerization initiator having an amino group such as 2,2'-azobis (2-methylpropionamidine), 2,2'-azobis [2- (2-imidazolin-2-yl) propane]; Examples thereof include radical polymerization initiators having a hydroxy group such as 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide]. Among these, it is preferable to use a radical polymerization initiator having a carboxyl group, and among them, it is more preferable to use 4,4'-azobis (4-cyanovaleric acid). Thereby, heat resistance and chemical resistance can be improved.

The amount (number of moles) of the radical polymerization initiator added is preferably 1% or more and 10% or less of the total number of moles of the monomer A and the monomer B. The weight average molecular weight (Mw) of the obtained copolymer can be adjusted by appropriately setting the amount of the radical polymerization initiator within the above range and appropriately setting the reaction temperature and the reaction time.

The chain transfer agent is preferably, but not limited to, one containing a functional group that reacts with the cross-linking agent. This makes it possible to introduce a functional group that reacts with the cross-linking agent into Y, which is one of the ends of the copolymer. Therefore, the number of copolymers containing a functional group that reacts with a cross-linking agent at both ends of the copolymer, X and Y, can be increased as compared with the case where the chain transfer agent is not used. This is because, in addition to the above-mentioned stop reaction, a chain transfer reaction occurs, and recombination stop, disproportionation stop, and chain transfer reaction compete with each other. As a result, the crosslinked structure can be formed more densely, and heat resistance and chemical resistance can be improved.
Specific examples of the chain transfer agent containing a functional group that reacts with the cross-linking agent include 2-{[(2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propanoic acid and 4-[(2-carboxyl). Ethyl sulfanylthiocarbonyl) Sulfanyl] -4-cyanopentanoic acid and other carboxyl group chain transfer agents, trithiocarbonate bis {4- [ethyl- (2-hydroxyethyl) carbamoyl] benzyl} and other hydroxyl group chain transfer Examples include agents. Among these, a chain transfer agent having a carboxyl group is preferable.

The amount of the chain transfer agent added (number of moles) is preferably 1% or more and 10% or less of the total number of moles of the monomer A and the monomer B. The weight average molecular weight (Mw) of the obtained copolymer can be adjusted by appropriately setting the amount of the polymerization initiator within the above range and appropriately setting the reaction temperature and the reaction time.

As the solvent, for example, one or more of diethyl ether, tetrahydrofuran, toluene and the like can be used.

By this polymerization step, a copolymer having a structural unit derived from monomer A and a structural unit derived from monomer B and having a terminal derived from a radical polymerization initiator can be synthesized.

(Low molecular weight component removing step (S2))
Next, the organic layer containing the copolymer and low molecular weight components such as residual monomers and oligomers is concentrated and then dissolved again in an organic solvent such as THF. Then, hexane and methanol are added to this solution to coagulate and precipitate the copolymer containing the copolymer. Here, the low molecular weight component includes a residual monomer, an oligomer, a polymerization initiator and the like. Then, filtration is performed and the obtained coagulated product is dried. As a result, it is possible to obtain a copolymer containing the copolymer from which the low molecular weight component has been removed as the main component (main product).
In the present embodiment, in the low molecular weight component removing step (S2), it is preferable to repeat the extraction operation until the content of low nuclei having a molecular weight of 1000 or less in the copolymer becomes 1% or less. Thereby, the amount of the low molecular weight component in the copolymer can be reduced to a sufficient extent to suppress the pattern deformation of the film at the time of curing.

When the monomer B contains maleic anhydride, the ring-opening step (S3) and the washing step (S4) may be performed after the polymerization step (S1) and before the low molecular weight component removing step (S2). .. This will be described below.

(Ring-opening step (S3))
In the ring-opening step, in the obtained copolymer, among the structural units derived from maleic anhydride, some repeating units are ring-closed and the remaining repeating units are ring-opened. Thereby, the amount of carboxyl groups in the copolymer can be adjusted. That is, the acid value of the produced copolymer can be controlled. Then, by controlling the acid value, the alkali solubility of the photosensitive resin composition can be adjusted.
In the present embodiment, among the repeating units derived from maleic anhydride of the copolymer, for example, 50% or more of the repeating units are not ring-opened, and the cyclic structure (anhydrous ring) of the remaining repeating units is opened. .. That is, the ring-opening rate of the copolymer is, for example, less than 50%. Among them, it is preferable to open the ring of 10% or more and 30% or less of the total number of repeating units of the cyclic structure derived from maleic anhydride of the copolymer.

Here, the ring-opening rate of the repeating unit derived from maleic anhydride can be measured as follows.
The IR absorption intensity (Abs1) of (C = O) in the acid anhydride structure of the copolymer before ring opening was measured, and the IR absorption intensity (Abs2) of (C = O) in the acid anhydride structure after ring opening was measured. The ring-opening rate is calculated by the following formula.
Ring-opening rate (%) = (((Abs1)-(Abs2)) / (Abs1)) × 100
Acetonitrile is used as an internal standard substance.

In particular,
(I) Metal alkoxide as a base (ii) Either alcohol or an alkali metal hydroxide as a base is added to the reaction solution in which the copolymer is polymerized in the polymerization step, and methyl ethyl ketone (i) is added to the reaction solution. An organic solvent such as MEK) is further added, and the mixture is stirred at 40 ° C. or higher and 50 ° C. or lower for 1 hour or more and 5 hours or less to obtain a reaction solution L1. In the reaction solution L1, a part of the anhydrous ring of the repeating unit derived from maleic anhydride of the copolymer is opened, and a part of the terminal formed by the ring opening is esterified. The remaining ends are not esterified and have a metal salt structure.

In the present embodiment, the number of moles of the metal alkoxide or alkali metal hydroxide is preferably 50% or less of the number of moles of maleic anhydride used in the polymerization step. Among them, the number of moles of the metal alkoxide or alkali metal hydroxide is preferably 40% or less, 10% or more, and further 30% or less of the number of moles of maleic anhydride used in the polymerization step. Is preferable. By doing so, the amount of the metal alkoxide or the hydroxide of the alkali metal can be reduced, and the alkali metal concentration in the finally obtained copolymer can be reduced.
By reducing the alkali metal concentration in the copolymer, it is possible to suppress the migration of metal ions when a device using this copolymer is formed.

As the above-mentioned metal alkoxide, those represented by M (OR ₉ ) (M is a monovalent metal, R ₉ is an organic group having 1 to 30 carbon atoms) are preferable. Examples of the metal M include alkali metals, and among them, sodium is preferable from the viewpoint of handleability. The R _9, are the same as those for _{R 9} in the example above general formula (B1).
As the metal alkoxide, two or more different types may be used. However, from the viewpoint of production stability, it is preferable to use one kind of metal alkoxide.

On the other hand, as described above, the structure derived from maleic anhydride of the copolymer may be ring-opened in the presence of (ii) an alcohol and a hydroxide of an alkali metal as a base.
As the alkali metal hydroxide, sodium hydroxide is preferable from the viewpoint of handleability.
As the alcohol, monohydric alcohol (R ₉ OH) is preferable. As the organic group R ₉ , the above-mentioned one can be used. It is preferable that R ₉ has 1 or more carbon atoms and 30 or less carbon atoms.

The repeating unit derived from maleic anhydride ring-opened in the ring-opening step (S3) has a structure represented by the following formula (5) and has a structure having a salt portion of a carboxyl group.

（Ｒ_９は炭素数１以上３０以下の有機基である。）

(R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

When the copolymer is opened with (i) a metal alkoxide as a base or (ii) an alcohol and an alkali metal hydroxide as a base, the following general formula (B2) and the following formula are used, although the amount is slight. The structure shown in (6) may be formed. In the following general formula (B2), R ₁₀ and R ₁₁ may be the same as the above R _8.

（Ｒ_１０、Ｒ_１１は、それぞれ独立して炭素数１以上３０以下の有機基である。）

(R ₁₀ and R ₁₁ are each independently an organic group having 1 or more and 30 or less carbon atoms.)

Next, the copolymer is acid-treated by adding an acidic aqueous solution such as hydrochloric acid or formic acid to the reaction solution L1 to replace the ^{metal ion (Na +} ) with a proton (H ^+).
The structural units represented by the above formulas (5) and (6) become the structural units represented by the following (B1) and (B4) by proton substitution, respectively.

（上記一般式（Ｂ１）中、Ｒ_９は炭素数１以上３０以下の有機基である。）

(In the above general formula (B1), R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

In this ring-opening step (S3), it is preferable not to open the ring of 50% or more of the repeating units derived from maleic anhydride of the copolymer. In the copolymer, as described above, a metal such as Na is bonded to one end formed by opening the anhydrous malein ring, but the repeating unit of 50% or more should not be opened. Therefore, the amount of metal contained in the product copolymer can be reduced. Thereby, the amount of the alkali metal in the copolymer finally obtained in the present embodiment can be reduced, and the desired property can be exhibited in the photosensitive resin composition using this copolymer. ..

(Washing step (S4))
When the ring-opening step (S3) is performed, the solution containing the copolymer after ring-opening obtained in the step is washed with a mixture of water and an organic solvent (for example, methyl ethyl ketone) to remove residual metal components. Remove. After ring opening, the copolymer, residual monomer and oligomer move to the organic layer. Then the aqueous layer is removed (first wash).
Then, the organic layer is washed again by adding a mixture of water and an organic solvent (for example, methyl ethyl ketone) (second washing).
In the present embodiment, the above cleaning step is repeated, for example, 5 times or more, more preferably 10 times. Further, by adjusting the amount of water and the organic solvent added in the washing step, it is preferable to remove 85% or more of the residual sodium by one washing step, and more preferably 90% or more. Thereby, the concentration of the alkali metal in the copolymer after ring opening can be sufficiently reduced. Further, when the residual sodium is removed with higher efficiency than this, an unnecessarily large amount of water and an organic solvent are used, and the copolymer yield may decrease, which is not preferable.
The washing step (S4) is preferably repeated so that the alkali metal concentration in the copolymer after ring opening is 10 ppm or less, preferably 5 ppm or less.

(Photosensitive resin composition)
In the present embodiment, the photosensitive resin composition can contain the above-mentioned copolymer, a cross-linking agent, and a photosensitive agent. In the present embodiment, for example, the crosslinked structure can be controlled by appropriately selecting the type and blending amount of each component contained in the photosensitive resin composition and the method for preparing the photosensitive resin composition. ..
The details of the cross-linking agent and the photosensitizer will be described below.

(Crosslinking agent)
In the present embodiment, the cross-linking agent is not limited as long as it is a compound containing a functional group that reacts with the active hydrogen of the copolymer.
The functional group that reacts with the active hydrogen of the copolymer preferably contains, for example, one or more selected from the group consisting of a glycidyl group, an oxetanyl group and a blocked isocyanate group, and preferably contains a glycidyl group or an oxetanyl group. Is more preferable, and it is more preferable to contain a glycidyl group. Thereby, an appropriate crosslinked structure can be formed.
Further, as the photosensitive resin composition, one kind or two or more kinds selected from a compound having a blocked isocyanate group, an epoxy compound and an oxetane compound can be used in combination.

Examples of the compound having a glycidyl group used as a cross-linking agent include allyl glycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, and bisphenol A. (Or F) glycidyl ether such as glycidyl ether, glycidyl ester such as adipic acid diglycidyl ester, glycidyl ester such as o-phthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate, 3, 4-epoxy-6-methylcyclohexylmethyl (3,4-epoxy-6-methylcyclohexane) carboxylate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, dicyclopentanediene oxide, bis (2, 3-Epoxycyclopentyl) ether, alicyclic epoxy such as Celoxide 2021, Celoxide 2081, Celoxide 2083, Celoxide 2085, Celoxide 8000, Epolide GT401, 2,2'-(((((1- (4)) -(2- (4- (Oxylan-2-ylmethoxy) phenyl) propan-2-yl) phenyl) ether-1,1-diyl) bis (4,1-phenylene)) bis (oxy)) bis (methylene) ) Bis (Oxylan) (for example, Techmore VG3101L (manufactured by Printec)), Epolite 100MF (manufactured by Kyoeisha Chemical Industry Co., Ltd.), Epiol TMP (manufactured by Nichiyu Co., Ltd.), 1,4-Cyclohexanedimethanol diglycidyl ether (New Japan) Aromas such as aliphatic glycidyl ethers such as those manufactured by Rika and Showa Denko, and fragrances such as 3,3', 5,5'-tetramethyl-4,4'-bis (glycidyloxy) -1,1'-biphenyl. Group glycidyl ether, 1,1,3,3,5,5-hexamethyl-1,5-bis (3- (oxylan-2-yl methoxy) propyl) tri-siloxane (for example, DMS-E09 (manufactured by Gerest) )) And other epoxy resins can be used.
Further, for example, bisphenol A type such as LX-01 (manufactured by Daiso), jER1001, 1002, 1003, 1004, 1007, 1009, 1010, 828, jER825 (trade name; manufactured by Mitsubishi Chemical Co., Ltd.). Epoxy resin, bisphenol F type epoxy resin such as jER807 (trade name; manufactured by Mitsubishi Chemical Co., Ltd.), jER152, 154 (trade name; manufactured by Mitsubishi Chemical Co., Ltd.), EPPN201, 202 (trade name; manufactured by Nippon Kayaku Co., Ltd.), etc. Phenol novolac type epoxy resin, EOCN102, 103S, 104S, 1020, 1025, 1027 (trade name; manufactured by Nippon Kayaku Co., Ltd.), jER157S70 (trade name; manufactured by Mitsubishi Chemical Co., Ltd.) and other cresol novolac type epoxy resins, Araldite. CY179, 184 (trade name; manufactured by Huntsman Advanced Materials), ERL-4206, 4221, 4234, 4299 (trade name: manufactured by Dow Chemical), Epicron 200, 400 (trade name; manufactured by DIC), jER871, Cyclic aliphatic epoxy resin such as 872 (trade name; manufactured by Mitsubishi Chemical Co., Ltd.), Poly [(2-oxyranyl) -1,2-cyclohexanediol] 2-ethyl-2- (hydroxymethyl) -1,3-propanediol ether ( A polyfunctional alicyclic epoxy resin such as 3: 1), EHPE-3150 (manufactured by Daicel) can also be used.
The photosensitive resin composition may contain one or more of the epoxy compounds exemplified above.

Examples of the compound having an oxetane group used as a cross-linking agent include 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene and bis [1-ethyl (3-oxetanyl)] methyl ether. , 4,4'-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, 4,4'-bis (3-ethyl-3-oxetanylmethoxy) biphenyl, ethylene glycol bis (3-ethyl-3-3) Oxetanylmethyl) ether, diethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, bis (3-ethyl-3-oxetanylmethyl) diphenoate, trimethylpropanthris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol Tetrax (3-ethyl-3-oxetanylmethyl) ether, poly [[3-[(3-ethyl-3-oxetanyl) methoxy] propyl] silaseskioxane] derivative, oxetanyl silicate, phenol novolac-type oxetane, 1,3- Examples thereof include oxetane compounds such as bis [(3-ethyloxetane-3-yl) methoxy] benzene.
The photosensitive resin composition may contain one or more of the oxetane compounds exemplified above.

The compound having a blocked isocyanate group used as a cross-linking agent is not limited, and is, for example, a compound in which the isocyanate group of a polyfunctional isocyanate is protected by a blocking agent.

The polyfunctional isocyanate is an organic compound having a plurality of isocyanate groups in one molecule. Examples of the polyfunctional isocyanate include 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 2,2,4-. Trimethyl-1,6-hexamethylene diisocyanate, lysine diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate), 1 , 3-Bis (isocyanate methyl) -cyclohexane, 4,4'-dicyclohexylmethane diisocyanate, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalenede Diisocyanate compounds such as isocyanate, trizine diisocyanate, xylylene diisocyanate; isocyanurate-modified polyfunctional isocyanate, bullet-modified polyfunctional isocyanate, urethane-modified polyfunctional isocyanate, etc. One or more selected from the derivatives of the diisocyanate compound and the like can be mentioned.

Examples of the blocking agent include alcohol compounds, phenol compounds, active methylene compounds, mercaptan compounds, acid amide compounds, acid imide compounds, imidazole compounds, urea compounds, and oximes. One or more selected from system compounds, amine compounds, imine compounds, barrous sulfate, pyridine compounds and the like can be mentioned.
Specific examples of the blocking agent include oxime, etanol, propanol, butanol, 2-ethylhexanol, methyl cellosolve, butyl cellosolve, methyl carpitor, benzyl alcohol, cyclohexanol and the like. Alcor compounds; phenol compounds such as phenol, cresol, ethylphenol, butylphenol, nonylphenol, dinonylphenol, styrenated phenol, hydroxybenzoic acid ester; malonic acid Active methylene compounds such as dimethyl, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone; mercaptan compounds such as butyl mercaptan and dodecyl mercaptan; Oxime-based compounds such as; oxyimide-based compounds such as succinateimide and maleateimide; imidazole-based compounds such as imidazole and 2-methylimidazole; urea-based compounds such as urea, thiourea and ethyleneurea. Compounds; Oxime compounds such as formaldehyde, acetoaldoxime, acetoxime, methylethylketooxime, cyclohexanone oxime; amine compounds such as diphenylamine, aniline, and carbazole; imide compounds such as ethyleneimine and polyethyleneimine; Das and other heavy sulfites; pyridine compounds such as 2-hydroxypyridine and 2-hydroxyquinoline can be mentioned.

Specific examples of the compound having a blocked isocyanate group used as such a cross-linking agent include Barnock D-500 (tolylene diisocyanate blocked product) and Barnock D-550 manufactured by Dainippon Ink and Chemicals Co., Ltd. 1,6-Hexamethylene diisocyanate blocked product), Burnock D-980K (1,6-hexamethylene diisocyanate blocked product); Takeda Chemical Co., Ltd. Takenate B-830 (Trilens isocyanate) -Toblocked product), Takenate B-815N (4,4'-methylenebis (cyclohexylisocyanate) blocked product), Takenate B-842N (1,3-bis (isocyanatemethyl) cyclohexaneblocked product), Takenate B-846N (1,3-Bis (isocyanatemethyl) cyclohexane blocked product), Takenate B-874N (isophoron diisocyanate blocked product), Takenate B-882N (1,6-hexamethylene diisocyanate blocked product) , Takenate B-890 (xylylene diisocyanate blocked); Takenate B-820NP (1,3-bis (isocyanatemethyl) cyclohexane blocked), Takenate B-885N (1,6-hexamethylene diisocyanate) -Toblocked product); Examples thereof include Duranate MF-B60X (1,6-hexamethylene diisocyanate blocked product) and Duranate MF-K60X (1,6-hexamethylene diisocyanate blocked product) manufactured by Asahi Kasei Co., Ltd. The photosensitive resin composition according to the present embodiment may contain one or more of these.

(Photosensitive agent)
When the photosensitive resin composition is of the positive type, a photoactive compound can be used as the photosensitizer, and for example, a diazoquinone compound can be used.
For example, any one or more of the following compounds can be used.

（ｎ２は、１以上、５以下の整数である。）

(N2 is an integer of 1 or more and 5 or less.)

In each of the above compounds, Q is any of the structures shown below or a hydrogen atom. However, at least one of the Qs of each compound is any of the following.
Of these, an o-naphthoquinonediazide sulfonic acid derivative having a Q of (a) or (b) is preferable from the viewpoint of transparency and dielectric constant of the photosensitive resin composition.

In addition to the above-mentioned photoactive compound, the positive photosensitive resin composition may contain an acid generator that generates an acid by light or heat. By including such an acid generator, the cross-linking reaction of the cross-linking agent can be promoted by exposing and developing the photosensitive resin composition and then irradiating or heating the photosensitive resin composition with light.
In this case, the amount of the acid generator is preferably 3 parts by mass or less with respect to 100 parts by mass of the cross-linking agent.
As the photoacid generator that generates acid by light, those described later can be used.
Examples of the thermoacid generator that generates an acid by heat include aromatic sulfonium salts such as SI-45L, SI-60L, SI-80L, SI-100L, SI-110L, and SI-150L (manufactured by Sanshin Chemical Industry Co., Ltd.). Can be used.
The content of the thermoacid generator is preferably 0.1% by mass or more and 5% by mass or less, for example, when the total solid content of the photosensitive resin composition is 100% by mass.
In the present embodiment, the total solid content of the photosensitive resin composition means a component excluding the solvent.

When the photosensitive resin composition is a negative type, a photoacid generator can be used as the photosensitive agent. The photoacid generator may be any agent that absorbs the energy of light to produce blended acid or Lewis acid, for example, triphenylsulfonium trifluoromethanesulfonate, tris (4-t-butylphenyl) sulfonium-trifluo. Sulfonium salts such as lomethanesulfonate; diazonium salts such as p-nitrophenyldiazonium hexafluorophosphate; ammonium salts; phosphonium salts; diphenyliodonium trifluoromethanesulfonates, iodonium salts such as (tricmill) iodonium-tetrakis (pentafluorophenyl) borate; quinonediazide , Diazomethanes such as bis (phenylsulfonyl) diazomethane; sulfonic acid esters such as 1-phenyl-1- (4-methylphenyl) sulfonyloxy-1-benzoylmethane, N-hydroxynaphthalimide-trifluoromethanesulfonate; diphenyl Disulfons such as disulfones; tris (2,4,6-trichloromethyl) -s-triazine, 2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, etc. Examples include compounds such as triazines. These photoacid generators can be used alone or in combination of two or more.

When the photosensitive resin composition is a negative type, a second cross-linking agent that crosslinks the copolymer by the action of an acid may be included. This second cross-linking agent cross-links the copolymer using the acid generated by the photo-acid generator as a catalyst, and is different from the compound used for the cross-linking agent.
For example, a melamine-based cross-linking agent, a urea-based cross-linking agent, and the like can be mentioned.
Examples of the melamine-based cross-linking agent include hexamethoxymethylmelamine, hexaethoxymethylmelamine, hexapropoxymethylmelamine, hexabutoxybutyl melamine and the like, and hexamethoxymethylmelamine is preferable.
Examples of the urea-based cross-linking agent include methylated urea resin, bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, bisbutoxymethylurea, and the like, and methylated urea resin is particularly preferable.
Examples of commercially available products of the methylated urea resin include MX-270, MX-280, and MX-290 (manufactured by Sanwa Chemical Co., Ltd.).

The ratio of the second cross-linking agent in the negative type photosensitive resin composition is preferably 5% by mass or more and 40% by mass or less when the total solid content of the resin composition is 100% by mass, and the resolution is high. From the viewpoint, it is more preferably 5% by mass or more and 30% by mass or less, and further preferably 10 to 25% by mass.

In the above photosensitive resin composition, when the photosensitive resin composition is a positive type, the ratio of each component is as follows, for example.
When the total solid content of the photosensitive resin composition is 100% by mass, it is preferable that the above-mentioned copolymer is contained in an amount of, for example, 30% by mass or more and 70% by mass or less, and in particular, 40% by mass or more and 60% by mass or less. It is preferably contained below.
Further, when the total solid content of the photosensitive resin composition is 100% by mass, the cross-linking agent is preferably contained, for example, 15% by mass or more and 50% by mass or less, and more than 20% by mass or more and 50% by mass or less. It is preferable to do so.
Furthermore, when the total solid content of the photosensitive resin composition is 100% by mass, it is preferable that the photoactive compound as a photosensitive agent is contained, for example, 5% by mass or more and 40% by mass or less, and 10% by mass or more and 30% by mass. It is more preferably contained in an amount of% by mass or less.

When the photosensitive resin composition is a negative type, the ratio of each component is as follows, for example.
When the total solid content of the photosensitive resin composition is 100% by mass, it is preferable that the above-mentioned copolymer is contained in an amount of, for example, 30% by mass or more and 70% by mass, and above all, 40% by mass or more and 60% by mass or less. It is preferable to contain it.
Further, when the total solid content of the photosensitive resin composition is 100% by mass, it is preferable to contain a cross-linking agent (excluding the second cross-linking agent), for example, 15% by mass or more and 50% by mass or less. It is preferably contained in an amount of 20% by mass or more and 50% by mass or less.
Furthermore, when the total solid content of the photosensitive resin composition is 100% by mass, the amount of the photoacid generator is, for example, 0.1% by mass or more and 40% by mass or less, forming a high-resolution pattern film. More preferably, it is 1% by mass or more and 30% by mass or less.

Additives such as a solvent, an antioxidant, a surfactant, an adhesion aid, a dissolution accelerator, a filler, a sensitizer, and polyphenols may be further added to the photosensitive resin composition.
The details of the representative components will be described below.

(solvent)
The photosensitive resin composition described in this embodiment can be used as a varnish by dissolving each of the above-mentioned components in a solvent.
Examples of such solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol. Monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, and ethyl and methyl pyruvate. -3-methoxypropionate and the like can be mentioned.

(Antioxidant)
By adding an antioxidant, it is possible to suppress the oxidation of the photosensitive resin composition during curing and the oxidation of the film in the subsequent process.
Antioxidants include pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t-butyl) propionate]. -4-Hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, octadecyl-3- (3,5-di) -T-Butyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl- 2,4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl- 4-Ethylphenol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-di-t-butyl-4-hydroxyphenyl) propionate, distearyl (3,5-di-t-butyl-4) -Hydroxybenzyl) phosphonate, thiodiethylene glycolbis [(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-t-butyl-m-cresol), 2-octylthio -4,6-di (3,5-di-t-butyl-4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-t-butyl-6-butylphenol), 2 , -2'-Methylenebis (4-ethyl-6-t-butylphenol), bis [3,3-bis (4-hydroxy-3-t-butylphenyl) butyl] glycol ester, 4,4'-butylidenebis (6) -T-butyl-m-cresol), 2,2'-etylidenebis (4,6-di-t-butylphenol), 2,2'-etylidenebis (4-s-butyl-6-t-butylphenol), 1,1,3-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, bis [2-t-butyl-4-methyl-6- (2-hydroxy-3-t-butyl-) 5-Methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-t-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-di) -T-Butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-Tris [(3,5-di-t-) Butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 2-t-butyl-4-methyl- 6- (2-acryloyloxy-3-t-butyl-5-methylbenzyl) phenol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5,5] Undecane-bis [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], triethylene glycol bis [β- (3-t-butyl-4-hydroxy-5-5-) Methylphenyl) propionate], 1,1'-bis (4-hydroxyphenyl) cyclohexane, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6) -T-butylphenol), 2,2'-methylenebis (6- (1-methylcyclohexyl) -4-methylphenol), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 3,9- Bis (2- (3-t-butyl-4-hydroxy-5-methylphenylpropionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 4 , 4'-thiobis (3-methyl-6-t-butylphenol), 4,4'-bis (3,5-di-t-butyl-4-hydroxybenzyl) sulfide, 4,4'-thiobis (6-- t-Butyl-2-methylphenol), 2,5-di-t-butylhydroquinone, 2,5-di-t-amyl-hydroquinone, 2-t-butyl-6- (3-t-butyl-2-) Hydroxy-5-methylbenzyl) -4-methylphenylacrylate, 2,4-dimethyl-6- (1-methylcyclohexyl) styrenated phenol, 2,4-bis ((octylthio) methyl) -5-methylphenol, etc. Phenol antioxidants; bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, tris (2,4-di-t-butylphenylphosphite), tetrakis (2, 4-di-t-butyl-5-methylphenyl) -4,4'-biphenylenediphosphonite, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, bis- (2,6-) Dikmylphenyl) pentaerythri Tall diphosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite, tris (mixed monoand di-nonylphenylphosphite), bis (2,4-di-t-) Butylphenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-methoxycarbonylethyl-phenyl) pentaerythritol diphosphite, bis (2,6-di-t-butyl-4-octadecyl) Phosphorus antioxidants such as oxycarbonylethylphenyl) pentaerythritol diphosphite; dilauryl-3,3'-thiodipropionate, bis (2-methyl-4- (3-n-dodecyl) thiopropionyloxy)- Examples thereof include thioether-based antioxidants such as 5-t-butylphenyl) sulfide, distearyl-3,3'-thiodipropionate, and pentaerythritol-tetrakis (3-lauryl) thiopropionate.
Among these, it is preferable to use a hindered phenolic antioxidant which is a phenolic antioxidant; and phosphite and phosphate which are phosphorus-based antioxidants.

(Surfactant)
Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether, and poly such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether. Nonionic surfactants such as polyoxyethylene dialkyl esters such as oxyethylene aryl ethers, polyoxyethylene dilaurate, and polyoxyethylene distearate, Ftop EF301, Ftop EF303, Ftop EF352 (manufactured by Shin-Akita Kasei Co., Ltd.) ), Mega Fuck F171, Mega Fuck F172, Mega Fuck F173, Mega Fuck F177, Mega Fuck F444, Mega Fuck F470, Mega Fuck F471, Mega Fuck F475, Mega Fuck F482, Mega Fuck F477 (manufactured by DIC), Florard FC- 430, Florard FC-431, Novell FC4430, Novell FC4432 (manufactured by Sumitomo 3M), Surflon S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-102, Surflon Organosiloxane copolymer KP341 (Shinetsu Chemical Industry Co., Ltd.), a fluorine-based surfactant commercially available under the names SC-103, Surflon SC-104, Surflon SC-105, Surflon SC-106, (manufactured by AGC Seimi Chemical Co., Ltd.) (Made by), (meth) acrylic acid-based copolymer polyflow No. 57, 95 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like can be mentioned. Among these surfactants, fluorine-based surfactants are preferable.
Among these, a fluorine-based surfactant having a perfluoroalkyl group is effective. Specifically, Mega Fvck F171, Mega Fvck F173, Mega Fvck F444, Mega Fvck F470, Mega Fvck F471, Mega Fvck F475, Mega Fvck F482, Mega Fvck F477 (manufactured by DIC), Surflon S-381, Surflon S- 383, Surflon S-393 (manufactured by AGC Seimi Chemical Co., Ltd.), Novec FC4430, Novec FC4432 (manufactured by Sumitomo 3M Ltd.) and the like can be mentioned.

(Adhesion aid)
The adhesion aid is a component that improves the adhesion of the photosensitive resin film obtained by using the photosensitive resin composition and the cured film thereof to other members.
Such adhesion aids are not limited, but are various silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, vinylsilane, and methacrylsilane; organosilicon having one carboxyl group in the molecule. Compounds: Includes organosilicon compounds having a plurality of carboxyl groups in the molecule. This makes it possible to further improve the adhesion of the photosensitive resin composition during development and after curing. Therefore, it is possible to realize more stable production of electronic devices.

(Dissolution accelerator)
The dissolution accelerator is a component capable of improving the solubility of the exposed portion of the resin film obtained by curing the photosensitive resin composition in a developing solution and improving the scum at the time of patterning.
As such a dissolution accelerator, for example, a compound having a phenolic hydroxyl group, an alkylol compound, a methylol compound, an acrylate compound and the like can be used. Of these, bifunctional or higher functional alkylol compounds, methylol compounds, and acrylate compounds, which can improve the mechanical properties of the permanent film by cross-linking in the permanent film, are preferable.

(Filler)
The filler is not limited, and for example, an organic filler or an inorganic filler can be used.
Specific examples of the organic filler include an organic filler formed of an epoxy resin, a melamine resin, a urea resin, an acrylic resin, a phenol resin, a polyimide resin, a polyamide resin, a polyester resin, a fluorine resin, or the like.
Specific examples of the inorganic filler include metal oxide fine particles such as alumina, silica, magnesia, ferrite, aluminum oxide, and zirconium oxide; silicates such as talc, mica, kaolin, and zeolite; barium sulfate, calcium carbonate, and fullerene. Such as fine particles can be mentioned. The photosensitive resin composition may contain one or more of these.

(Sensitizer)
The sensitizer is suitable for the function of increasing the sensitivity of the photoacid generator to light to reduce the time and energy required for activation (reaction or decomposition) of the photoacid generator, and for activating the photoacid generator. It has a function of changing the wavelength of active light to a wavelength.
Such a sensitizer is not limited, and can be appropriately selected depending on the sensitivity of the photoacid generator and the peak wavelength of absorption of the sensitizer. Specific sensitizers include anthracenes such as 9,10-dibutoxyanthracene (CAS number 76275-14-4), xanthones, anthraquinones, phenanthrenes, chrysene, benzpyrenes, and fluoranthenes. (Fluoranthenes), rubrenes, pyrenes, indance leans, thioxanthene-9-ones, etc. are exemplified, and any one or more of them can be used.

(Polyphenols)
Examples of polyphenols include phenol novolac, o-cresol novolak, p-cresol novolak, pt-butylphenol novolak, hydroxynaphthalene novolak, bisphenol A novolak, bisphenol F novolak, terpen-modified novolak, dicyclopentadiene-modified novolak, and para. Examples thereof include xylene-modified novolak and polybutadiene-modified phenol, and any one or more of them can be used.

The following phenolic compounds can also be used.
o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, bisphenol A, B, C, E, F and G, 4,4', 4 " -Methylidinetrisphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 4,4'-[1- [4- [1- (4-hydroxyphenyl)) -1-Methylethyl] phenyl] ethylidene] bisphenol, 4,4'-[1- [4- [2- (4-hydroxyphenyl) -2-propyl] phenyl] ethylidene] bisphenol, 4,4', 4 " − Ethylidinetrisphenol, 4- [bis (4-hydroxyphenyl) methyl] -2-ethoxyphenol, 4,4'-[(2-hydroxyphenyl) methylene] bis [2,3-dimethylphenol], 4, 4'-[(3-Hydroxyphenyl) methylene] bis [2,6-dimethylphenol], 4,4'-[(4-hydroxyphenyl) methylene] bis [2,6-dimethylphenol], 2,2' -[(2-Hydroxyphenyl) methylene] bis [3,5-dimethylphenol], 2,2'-[(4-hydroxyphenyl) methylene] bis [3,5-dimethylphenol], 4,4'-[ (3,4-dihydroxyphenyl) methylene] bis [2,3,6-trimethylphenol], 4- [bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) methyl] -1,2-benzenediol, 4,6-bis [(3,5-dimethyl-4-hydroxyphenyl) methyl] -1,2,3-benzenetriol, 4,4'-[(2-hydroxyphenyl) methylene] bis [3-methylphenol ], 4,4', 4 "-(3-methyl-1-propanol-3-iridin) trisphenol, 4,4', 4", 4 "'-(1,4-phenylenedimethylidine) tetrakis Phenol, 2,4,6-tris [(3,5-dimethyl-4-hydroxyphenyl) methyl] -1,3-benzenediol, 2,4,6-tris [(3,5-dimethyl-2-hydroxy) Phenyl) methyl] -1,3-benzenediol, 4,4'-[1- [4- [1- [4-hydroxy-3,5-bis [(hydroxy-3-methylphenyl) methyl] phenyl]- 1-Methylethyl] phenyl] etiliden] bis [2,6-bis (hydroxy-3-methylphenyl) methyl] phenol And so on.
Of these compounds, 4,4', 4 "-methylidinetrisphenol, 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenol, 4,4'-[1 -[4- [1- (4-Hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, 4,4'-[1- [4- [2- (4-hydroxyphenyl) -2-propyl]] Phenyl] ethylidene] bisphenol, 4,4', 4 "-ethylidinetrisphenol and the like are preferred. Any one or more of these can be used. More preferably, it is any one or more of the following compounds.

In the photosensitive resin composition, the content of polyphenols is preferably 0.1% by mass or more and 30% by mass or less, and is preferably 3% by mass or more and 30% by mass or less, when the solid content excluding the solvent is 100% by mass. % Or less is preferable.

(Preparation of photosensitive resin composition)
The method for preparing the photosensitive resin composition in the present embodiment is not limited, and it can be prepared by using a conventionally known method.
For example, each of the above components can be prepared by mixing and dissolving in a solvent. Thereby, a photosensitive resin composition as a varnish can be obtained.

(Use)
The resin film of the present embodiment is made of the above-mentioned photosensitive resin composition. The resin film is specifically a dry film or a cured film of a photosensitive resin composition.
The photosensitive resin composition of the present embodiment is used for forming a resin film such as a resist or a permanent film. Such applications are suitable from the viewpoint of heat resistance.
The resist is a resin film obtained by applying, for example, a photosensitive resin composition by a method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating to remove the solvent. It is composed.
The permanent film is composed of a cured film obtained by exposing and developing the resin film, patterning it into a desired shape, and then curing it by heat treatment or the like. The permanent film can be used, for example, as a protective film, an interlayer film, a dam material, or the like.

The electronic device 100 of the present embodiment can be an electronic device provided with the resin film. Specifically, in the electronic device 100, one or more of the group consisting of the passivation film 32, the insulating layer 42, and the insulating layer 44 can be a resin film. Here, it is preferable that the resin film is formed by exposing a coating film formed of a photosensitive resin material to ultraviolet rays, developing the coating film to pattern the coating film, and then heat-curing the coating film.

The electronic device 100 will be described below.
The electronic device 100 shown in FIG. 1 is, for example, a semiconductor chip. In this case, for example, a semiconductor package can be obtained by mounting the electronic device 100 on the wiring board via the bump 52. The electronic device 100 includes a semiconductor substrate provided with a semiconductor element such as a transistor, and a multilayer wiring layer (not shown) provided on the semiconductor substrate. The uppermost layer of the multilayer wiring layer is provided with an interlayer insulating film 30 and an uppermost layer wiring 34 provided on the interlayer insulating film 30. The top layer wiring 34 is made of, for example, aluminum Al. Further, a passivation film 32 is provided on the interlayer insulating film 30 and on the uppermost layer wiring 34. A part of the passivation film 32 is provided with an opening in which the uppermost layer wiring 34 is exposed.

A rewiring layer 40 is provided on the passivation film 32. The rewiring layer 40 includes an insulating layer 42 provided on the passivation film 32, a rewiring 46 provided on the insulating layer 42, and an insulating layer 44 provided on the insulating layer 42 and the rewiring 46. Has. The insulating layer 42 is formed with an opening for connecting to the uppermost layer wiring 34. The rewiring 46 is formed on the insulating layer 42 and in the openings provided in the insulating layer 42, and is connected to the uppermost layer wiring 34. The insulating layer 44 is provided with an opening for connecting to the rewiring 46.

Bumps 52 are formed in the openings provided in the insulating layer 44, for example, via the UBM (Under Bump Metallurgy) layer 50. The electronic device 100 is connected to a wiring board or the like via, for example, a bump 52.

（一般式（１）中、
ｌおよびｍはそれぞれ、共重合体中における、Ａ及びＢのモル含有率を示し、
ｌ＋ｍ＝１であり、
Ａは下記一般式（Ａ１）または一般式（Ａ２）により示される構造単位の１種以上を含み、
Ｂは下記一般式（Ｂ１）、一般式（Ｂ２）、式（Ｂ３）、式（Ｂ４）、式（Ｂ５）または一般式（Ｂ６）により示される構造単位の１種以上を含み、
Ｘは前記架橋剤と反応する官能基を含む炭素数１以上３０以下の有機基であり、
Ｙは水素または炭素数１以上３０以下の有機基である。）

（一般式（Ａ１）中、Ｒ _１ 、Ｒ _２ 、Ｒ _３ およびＲ _４ はそれぞれ独立して水素または炭素数１以上３０以下の有機基である。ただし、カルボキシル基を除く。
ａ _１ は０、１または２である。）

（一般式（Ａ２）中、Ｒ _５ 、Ｒ _６ 、Ｒ _７ およびＲ _８ はそれぞれ独立して水素または炭素数１以上３０以下の有機基であって、
Ｒ _５ 、Ｒ _６ 、Ｒ _７ およびＲ _８ に少なくとも１つのカルボキシル基を含み、
ａ _２ は０、１または２である。）

（一般式（Ｂ１）中、Ｒ _９ は、炭素数１以上３０以下の有機基である。）

（一般式（Ｂ２）中、Ｒ _１０ 及びＲ _１１ は、それぞれ独立して炭素数１以上３０以下の有機基である。）

（一般式（Ｂ６）中、Ｒ _１２ は炭素数１以上３０以下の有機基である。）
２． １．に記載の感光性樹脂組成物において、
前記架橋剤は、前記共重合体と反応する官能基として、グリシジル基、オキセタニル基及びブロックイソシアネート基からなる群より選択される１種以上を含む、感光性樹脂組成物。
３． １．または２．に記載の感光性樹脂組成物において、
前記一般式（１）で示される共重合体における前記Ｘは、前記架橋剤と反応する前記官能基として、カルボキシル基、一級アミノ基、二級アミノ基、ヒドロキシル基、イミダゾール基、イミダゾリン基、エステル基及びアミド基からなる群より選択される１種以上を含む、感光性樹脂組成物。
４． １．から３．のいずれかに記載の感光性樹脂組成物において、
前記一般式（１）で示される共重合体における前記Ａは、前記一般式（Ａ１）により示される構造単位及び前記一般式（Ａ２）により示される構造単位を含む、感光性樹脂組成物。
５． １．から４．のいずれかに記載の感光性樹脂組成物において、
前記一般式（１）で示される共重合体における前記Ｙは、架橋剤と反応する官能基としてカルボキシル基、一級アミノ基、二級アミノ基、ヒドロキシル基、イミダゾール類、イミダゾリン類、エステル基及びアミド基からなる群より選択される１種以上を含む、感光性樹脂組成物。
６． １．から５．のいずれかに記載の感光性樹脂組成物において、
前記一般式（１）で示される共重合体における前記Ｂは、前記式（Ｂ５）または前記一般式（Ｂ６）により示される構造単位を含む、感光性樹脂組成物。
７． １．から６．のいずれかに記載の感光性樹脂組成物からなる、樹脂膜。
８． ７．に記載の樹脂膜を備える、電子装置。
The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the embodiment will be added.
1. 1. With the copolymer represented by the following general formula (1),
With a cross-linking agent
Photosensitizer and
A photosensitive resin composition comprising.

(In general formula (1),
l and m indicate the molar content of A and B in the copolymer, respectively.
l + m = 1,
A includes one or more of the structural units represented by the following general formula (A1) or general formula (A2).
B includes one or more of the structural units represented by the following general formula (B1), general formula (B2), formula (B3), formula (B4), formula (B5) or general formula (B6).
X is an organic group having 1 to 30 carbon atoms and containing a functional group that reacts with the cross-linking agent.
Y is hydrogen or an organic group having 1 or more and 30 or less carbon atoms. )

(In the general formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms, except for the carboxyl group.
a ₁ is 0, 1 or 2. )

(In the general formula (A2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms.
R ₅ , R ₆ , R ₇ and R ₈ contain at least one carboxyl group
a ₂ is 0, 1 or 2. )

(In the general formula (B1), R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

(In the general formula (B2), R ₁₀ and R ₁₁ are independently organic groups having 1 or more and 30 or less carbon atoms.)

(In the general formula (B6), R ₁₂ is an organic group having 1 or more and 30 or less carbon atoms.)
2. 1. 1. In the photosensitive resin composition according to
The cross-linking agent is a photosensitive resin composition containing at least one selected from the group consisting of a glycidyl group, an oxetanyl group and a blocked isocyanate group as a functional group that reacts with the copolymer.
3. 3. 1. 1. Or 2. In the photosensitive resin composition according to
The X in the copolymer represented by the general formula (1) is a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an imidazole group, an imidazoline group, or an ester as the functional group that reacts with the cross-linking agent. A photosensitive resin composition containing one or more selected from the group consisting of a group and an amide group.
4. 1. 1. From 3. In the photosensitive resin composition according to any one of
The A in the copolymer represented by the general formula (1) is a photosensitive resin composition containing the structural unit represented by the general formula (A1) and the structural unit represented by the general formula (A2).
5. 1. 1. From 4. In the photosensitive resin composition according to any one of
The Y in the copolymer represented by the general formula (1) is a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, imidazoles, imidazolines, ester groups and amides as functional groups that react with the cross-linking agent. A photosensitive resin composition containing one or more selected from the group consisting of groups.
6. 1. 1. From 5. In the photosensitive resin composition according to any one of
The B in the copolymer represented by the general formula (1) is a photosensitive resin composition containing a structural unit represented by the formula (B5) or the general formula (B6).
7. 1. 1. From 6. A resin film comprising the photosensitive resin composition according to any one of.
8. 7. An electronic device comprising the resin film described in 1.

Next, examples of the present invention will be described.
First, each material used in the examples was prepared as shown below.

(Copolymer)
The copolymers of Synthesis Examples 1 to 3 below were prepared.
Hereinafter, the method for synthesizing each copolymer will be described in detail.

(Synthesis Example 1)
N-Methylmaleimide (2.8 g, 0.025 mol), 5-norbornene-2-carboxylic acid (1.7 g, 0.012 mol), 5- in an appropriately sized reaction vessel equipped with a stirrer and cooling tube. Methyl norbornene-2-carboxylate (1.9 g, 0.012 mol) and 4,4'-azobis (4-cyanovaleric acid) (0.06 g, 0.0002 mol) were weighed and dissolved in methyl ethyl ketone and toluene. ..
The solution was aerated with nitrogen for 10 minutes to remove oxygen, and then heated at 60 ° C. for 16 hours with stirring. Then, methyl ethyl ketone was further added to this solution.
Then, methanol and hexane were added to separate the organic layer to remove unreacted monomers.
Further, propylene glycol monomethyl ether acetate (PGMEA) was added, and methyl ethyl ketone, methanol and hexane in the system were distilled off under reduced pressure.
From the above, 20 g of a 20 mass% copolymer solution of Synthesis Example 1 containing each copolymer represented by the following formulas (7-1) and (7-2) was obtained (Mw = 8500 measured by GPC). , Mw / Mn = 1.8).

(Synthesis Example 2)
N-Methylmaleimide (2.8 g, 0.025 mol), 5-norbornen-2-carboxylic acid (1.7 g, 0.012 mol), 5- in a properly sized reaction vessel equipped with a stirrer and cooling tube. Methyl norbornen-2-carboxylate (1.9 g, 0.012 mol) and 4,4'-azobis (4-cyanovaleric acid) (0.07 g, 0.0002 mol), 2-{[(2-carboxyethyl) Sulfanylthiocarbonyl] sulfanyl} propanoic acid (0.006 g, 0.0002 mol) was weighed and dissolved in methyl ethyl ketone and toluene.
The solution was aerated with nitrogen for 10 minutes to remove oxygen, and then heated at 60 ° C. for 16 hours with stirring. Then, methyl ethyl ketone was further added to this solution.
Then, methanol and hexane were added to separate the organic layer to remove unreacted monomers.
Further, propylene glycol monomethyl ether acetate (PGMEA) was added, and methyl ethyl ketone, methanol and hexane in the system were distilled off under reduced pressure. As a result, 20 g of the 20 mass% copolymer solution of Synthesis Example 2 was obtained (Mw = 5500, Mw / Mn = 1.5 measured by GPC).

The obtained copolymer (0.03 g) of Synthesis Example 2 was distilled off under reduced pressure, dissolved in dimethyl sulfoxide (0.5 g), and ¹ H-NMR measurement was carried out with a nuclear magnetic resonance apparatus manufactured by JEOL Ltd. .. As a result, a peak of the terminal carboxyl group derived from 2-{[(2-carboxyethyl) sulfanylthiocarbonyl] sulfanyl} propanoic acid was confirmed at around 12.5 ppm. As a result, it was confirmed that a copolymer having a carboxyl group at the end of the copolymer was synthesized in Synthesis Example 2.
Further, compared with Mw = 8500 in Synthesis Example 1, Mw = 5500 in Synthesis Example 2. As a result, it was confirmed that radicals were transferred from the growth copolymer to the chain transfer agent in the process of synthesizing the copolymer.
From the above, the copolymer of Synthesis Example 2 is a copolymer having a structure represented by the following formulas (8-1), formula (8-2), formula (8-3) and formula (8-4). Including.

(Synthesis Example 3)
N-Methylmaleimide (2.8 g, 0.025 mol), 5-norbornene-2-carboxylic acid (1.7 g, 0.012 mol), 5- in an appropriately sized reaction vessel equipped with a stirrer and cooling tube. Methyl norbornene-2-carboxylate (1.9 g, 0.012 mol) and 2,2'-azobis (2-methylpropionic acid) dimethyl (0.06 g, 0.0002 mol) were weighed and dissolved in methyl ethyl ketone and toluene. I let you.
The solution was aerated with nitrogen for 10 minutes to remove oxygen, and then heated at 60 ° C. for 16 hours with stirring. Then, methyl ethyl ketone was further added to this solution.
Then, methanol and hexane were added to separate the organic layer to remove unreacted monomers.
Further, propylene glycol monomethyl ether acetate (PGMEA) was added, and methyl ethyl ketone, methanol and hexane in the system were distilled off under reduced pressure. As a result, 20 g of a 20 mass% copolymer solution of Synthesis Example 3 containing each of the copolymers represented by the following formulas (9-1) and (9-2) was obtained (Mw = measured by GPC). 10000, Mw / Mn = 1.5).

架橋剤２：下記式（１１）で表される、架橋剤（プリンテック社製、ＶＧ３１０１Ｌ）を使用した。

(Crosslinking agent)
Cross-linking agent 1: A cross-linking agent (LX-01 manufactured by Daiso Corporation) represented by the following formula (10) was used.

Cross-linking agent 2: A cross-linking agent (VG3101L manufactured by Printec Co., Ltd.) represented by the following formula (11) was used.

(Surfactant)
A surfactant having a perfluoroalkyl group (Megafuck F477, manufactured by DIC Corporation) was used as the surfactant 1.

(Photosensitive agent)
An esterified product of 4,4'-(1- {4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl} ethylidene) bisphenol and 1,2-naphthoquinonediazide-5-sulfonyl chloride (Daito Chemix) Manufacture: PA-28) was used as the photosensitizer 1.

(Preparation of Photosensitive Resin Compositions of Examples and Comparative Examples)
For each Example and each Comparative Example, a 20% PGMEA solution of the copolymer prepared in Synthesis Examples 1 to 3, a cross-linking agent, a surfactant, and a photosensitizer were added in an appropriate amount of propylene glycol 1 in the blending amounts shown in Table 1. -It was dissolved in monomethyl ether 2-acetylate (PGMEA) and stirred. After stirring, the mixture was filtered through a 0.2 μm filter to prepare a varnish-like photosensitive resin composition.
Here, in preparing the photosensitive resin compositions of each Example and each Comparative Example, PGMEA was prepared so that the content of the copolymer component was 30%.
All the compounding compositions shown in Table 1 are listed in parts by mass.

(sensitivity)
The photosensitive resin composition of Example 3 was rotationally coated on a 4-inch silicon wafer treated with HMDS (Hexamethyldisilazane), baked on a hot plate at 90 ° C. for 120 seconds, and then a thin film having a thickness of about 8.0 μm was obtained. This thin film was exposed to a Canon g + h + i line mask aligner (PLA-501F) using a mask having a line width of 10 μm and a space width of 1: 1. Next, the resist pattern formed by baking on a hot plate at 110 ° C. for 120 seconds and then developing with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds has a line width of 10 μm: space width =. The exposure amount (mJ / cm ² ) at 1: 1 was defined as the sensitivity.
As a result, it was confirmed that Example 3 was a photosensitive resin composition having appropriate sensitivity.

(Alkali soluble)
The photosensitive resin compositions of each Example and each Comparative Example were applied onto a silicon wafer and dried at 80 ° C. for 90 seconds to obtain a thin film having a thickness of about 5.0 μm. This thin film was immersed in a 2.38% TMAH developer for 3 minutes and then washed with pure water. The thin film after cleaning was visually observed, and the one without residue was marked with ◯, and the one with residue was marked with x.
From this, it was confirmed that each Example was a photosensitive resin composition having an appropriate alkali solubility.

(Preparation of resin film)
For each of each Example and each Comparative Example, a resin film was prepared as follows using the obtained photosensitive resin composition. First, a varnish-like photosensitive resin composition was applied to a 6-inch wafer, and then heat treatment was performed at 80 ° C. for 90 seconds to remove the solvent. Next, the photosensitive resin composition was heat-treated in an oven to cure the photosensitive resin composition. In each Example and each Comparative Example, the inside of the oven on which the wafer was placed was replaced with nitrogen at 30 ° C. for 30 minutes, the temperature was raised to 160 ° C. at a heating rate of 5 ° C./min, and then the temperature was increased to 160 ° C. The above heat treatment was performed by holding for 90 minutes. After the heat treatment, the temperature in the oven was lowered to 70 ° C. or lower at a temperature lowering rate of 5 ° C./min, and the wafer was taken out. Then, the cured film of the photosensitive resin composition was peeled off from the wafer using hydrofluoric acid, and dried under the conditions of 60 ° C. and 10 hours. As a result, a resin film was obtained.

(chemical resistance)
The chemical resistance of the resin film using the photosensitive resin composition of each Example and each Comparative Example was evaluated as follows.
First, the film thickness of the resin film prepared as described above was measured before immersion in the solvent. Next, the resin film was immersed in N-methylpyrrolidone (manufactured by Kanto Chemical Co., Inc.) at 60 ° C. for 10 minutes, rinsed with pure water, and then the film thickness after immersion in a solvent was measured.
From the film thickness before solvent immersion and the film thickness after solvent immersion measured from the above, the film thickness change rate was calculated using the following formula. The smaller the rate of change in film thickness, the higher the chemical resistance.
Film thickness change rate (%) = [{(Film thickness after solvent immersion)-(Film thickness before solvent immersion)} / (Film thickness before solvent immersion)] x 100

(Heat-resistant)
The glass transition temperature Tg was measured for the resin film using the photosensitive resin composition of each Example and each Comparative Example. The measurement was performed on a test piece made of a resin film (width 5 mm × length 10 mm or more × thickness 0.005 mm or more and 0.01 mm or less) using a thermomechanical analyzer (Thermo Mechanical Analysis: TMA) at a starting temperature of 30 ° C. The measurement was carried out under the conditions of a measurement temperature range of 30 ° C. to 400 ° C. and a heating rate of 5 ° C./min.

(Mechanical characteristics)
In addition to the above-mentioned chemical resistance and the above-mentioned heat resistance evaluation, mechanical properties were evaluated. This is because it is presumed that the photosensitive resin composition forming a dense crosslinked structure has improved mechanical properties.
The tensile elongation and tensile strength of the resin film using the photosensitive resin composition of each Example and each Comparative Example were measured as follows. First, a tensile test (tensile speed: 0.05 mm / min) was performed on a test piece made of a resin film (width 10 mm × length 60 mm or more × thickness 0.005 mm or more and 0.01 mm or less) at a temperature of 23 ° C. and a humidity of 55. Conducted in a% atmosphere. The tensile test was performed using a tensile tester (Tencilon RTC-1210A) manufactured by Orientec. Next, the tensile elongation and tensile strength were calculated from the results of the tensile test. Here, the above tensile test was performed with the number of tests n = 5, the maximum value of 5 times was obtained, and this was used as the measured value.
As a result of the evaluation of the mechanical properties, it was confirmed that the tensile elongation and the tensile strength were improved in Examples 2 and 3 using Synthesis Example 2 synthesized by using the chain transfer agent.

Table 1 below shows the blending amounts of each of the above-mentioned Examples and Comparative Examples, and the evaluation results.
A "-" in the evaluation result section indicates that no evaluation has been performed.

As shown in Table 1, it was confirmed that the photosensitive resin compositions of each example had improved heat resistance and chemical resistance as compared with the photosensitive resin compositions of each comparative example.

100 Electronic device 30 Interlayer insulating film 32 Passivation film 34 Top layer wiring 40 Rewiring layer 42, 44 Insulation layer 46 Rewiring 50 UBM layer 52 Bump

Claims (8)

With the copolymer represented by the following general formula (1),
With a cross-linking agent
Photosensitizer and
A positive photosensitive resin composition containing.

(In general formula (1),
l and m indicate the molar content of A and B in the copolymer, respectively.
l + m = 1, 0.1 ≦ l ≦ 0.9, 0.1 ≦ m ≦ 0.9,
A comprises a structure unit of displayed in accordance with one general formula (A2),
B includes one or more of the structural units represented by the following general formula (B1), general formula (B2), formula (B3), formula (B4), formula (B5) or general formula (B6).
X is an organic group having 1 to 30 carbon atoms and containing a functional group that reacts with the cross-linking agent.
Y is hydrogen or an organic group having 1 or more and 30 or less carbon atoms. )

(In the general formula (A1), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms, except for the carboxyl group.
a ₁ is 0, 1 or 2. )

(In the general formula (A2), R ₅ , R ₆ , R ₇ and R ₈ are each independently hydrogen or an organic group having 1 or more and 30 or less carbon atoms.
R ₅ , R ₆ , R ₇ and R ₈ contain at least one carboxyl group
a ₂ is 0, 1 or 2. )

(In the general formula (B1), R ₉ is an organic group having 1 or more and 30 or less carbon atoms.)

(In the general formula (B2), R ₁₀ and R ₁₁ are independently organic groups having 1 or more and 30 or less carbon atoms.)

(In the general formula (B6), R ₁₂ is an organic group having 1 or more and 30 or less carbon atoms.) In the positive photosensitive resin composition according to claim 1,
The cross-linking agent is a positive photosensitive resin composition containing at least one selected from the group consisting of a glycidyl group, an oxetanyl group and a blocked isocyanate group as a functional group that reacts with the copolymer. In the positive photosensitive resin composition according to claim 1 or 2.
The X in the copolymer represented by the general formula (1) is a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, an imidazole group, an imidazoline group, or an ester as the functional group that reacts with the cross-linking agent. A positive photosensitive resin composition containing one or more selected from the group consisting of a group and an amide group. The positive photosensitive resin composition according to any one of claims 1 to 3.
The A in the copolymer represented by the general formula (1) is a positive photosensitive resin composition containing the structural unit represented by the general formula (A1) and the structural unit represented by the general formula (A2). .. In the positive photosensitive resin composition according to any one of claims 1 to 4.
The Y in the copolymer represented by the general formula (1) is a carboxyl group, a primary amino group, a secondary amino group, a hydroxyl group, imidazoles, imidazolines, ester groups and amides as functional groups that react with the cross-linking agent. A positive photosensitive resin composition containing one or more selected from the group consisting of groups. The positive photosensitive resin composition according to any one of claims 1 to 5.
The B in the copolymer represented by the general formula (1) is a positive photosensitive resin composition containing a structural unit represented by the formula (B5) or the general formula (B6). A resin film comprising the positive photosensitive resin composition according to any one of claims 1 to 6. An electronic device comprising the cured film of the resin film according to claim 7.

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