JP2024157563A - Photosensitive resin composition - Google Patents

Abstract

The present invention provides a photosensitive resin composition capable of producing a resin film having a high Tg and thermal weight loss temperature and excellent chemical resistance while suppressing a decrease in the resolution of a relief pattern.
[Solution] A photosensitive resin composition comprising (A) a polyimide precursor, (B) a compound having a hydroxyl group and a polymerizable unsaturated bond, (C) a photosensitizer, (D) a solvent, and (E) free chlorine, wherein the amount of the free chlorine is 0.0001 to 2 ppm based on the total mass of the photosensitive resin composition.
[Selection diagram] None

Description

The present invention relates to a photosensitive resin composition.

Conventionally, polyimide resins, which have excellent heat resistance, electrical properties, and mechanical properties, have been used as insulating materials for electronic components, and as passivation films, surface protective films, and interlayer insulating films for semiconductor devices. Among these polyimide resins, those provided in the form of photosensitive polyimide precursors can easily form heat-resistant relief pattern films by applying the precursor, exposing it to light, developing it, and subjecting it to a thermal imidization treatment by curing it.

Meanwhile, there are various methods for packaging semiconductor devices. In recent years, the fan-out semiconductor packaging method has become mainstream. In a fan-out type semiconductor package, a chip sealing body larger than the chip size of the semiconductor chip is formed by covering the semiconductor chip with an encapsulant. Furthermore, a redistribution layer is formed that extends to the area of the semiconductor chip and the encapsulant. The redistribution layer is formed with a thin film thickness. Furthermore, because the redistribution layer can be formed up to the area of the encapsulant, the number of external connection terminals can be increased.

For example, the following Patent Document 1 is known as a fan-out type semiconductor device.

Patent No. 5563814

On the other hand, in recent years, the method of mounting semiconductor devices on printed wiring boards has changed in order to improve integration and computing functions, as well as to reduce chip size. In structures such as SiP, which allow for higher density mounting, a structure in which a polyimide coating directly contacts solder bumps has come to be used. When forming such a bump structure, the polyimide coating is required to have high heat resistance and chemical resistance. In the case of a resin composition that does not have heat resistance, a cured film with low heat resistance is produced when the resin composition is mounted on a substrate together with a semiconductor chip through a solder reflow process. A cured film with low heat resistance is prone to degassing and shrinkage due to temperature changes, and is prone to cracking and peeling.

More recently, there has been an increasing demand for thermosetting materials (low-temperature curing materials) that can be cured at low temperatures. Phenol resins have been widely developed as low-temperature curing materials for insulating film applications, but from the standpoint of chemical resistance and heat resistance, it is preferable to use polyimide resins. In order to cure polyimide resins, which are usually processed at 300 to 400°C, at low temperatures, it is common to use chemical imidization, in which a compound that promotes imidization is added, or to use soluble polyimides.

On the other hand, when heat treatment is performed at low temperatures, many low molecular weight compounds remain in the cured film and the interactions between the resins become weak, making it difficult to maintain the film's physical properties. In particular, in heating processes such as solder reflow in the processing of semiconductor devices, cracks and peeling are likely to occur due to degassing and shrinkage.

In order to prevent the resin film from peeling off from the Cu wiring during the reflow process, it is necessary to increase the glass transition point (Tg) and weight loss temperature of the resin film. However, in recent low-temperature heat curing processes, the curing process is performed at a temperature below the reflow temperature, so the Tg is lower than the reflow temperature, and there is a problem that low-molecular-weight compounds remain without volatilizing. There is a tendency for the Tg to increase by decreasing the molecular weight between crosslinking points of the cured film. However, if the functional group concentration or the amount of radical polymerizable compound that is generally used in combination with a polyimide precursor in a negative photosensitive resin composition is increased, the resolution of the relief pattern decreases, so it is difficult to improve the Tg of the resin film while maintaining the resolution. In addition, in order to increase the thermal weight loss temperature of the resin film, it is necessary to completely volatilize or fix the low-molecular-weight compounds in the resin film.

The present invention was made in consideration of these problems, and one of its objectives is to provide a photosensitive resin composition that can produce a resin film that has a high Tg and thermal weight loss temperature and excellent chemical resistance while suppressing a decrease in the resolution of the relief pattern.

｛式（１）中、Ｘ_１は、炭素数６～４０の４価の有機基であり、Ｙ_１は、炭素数６～４０の２価の有機基であり、ｎ１は、２～１５０の整数であり、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、又は炭素数１～４０の１価の有機基である。ただし、Ｒ_１及びＲ_２の少なくとも一方は、下記一般式（２）：

で表される基であり、式（２）中、Ｒ_３、Ｒ_４及びＲ_５は、それぞれ独立に、水素原子又は炭素数１～３の１価の有機基であり、そしてｍ１は、２～１０の整数である。｝
［４］
上記（Ａ）ポリイミド前駆体１００質量部に対し、上記（Ｄ）溶剤を１００～８６０質量部含む、項目１～３のいずれか１項に記載の感光性樹脂組成物。
［５］
上記（Ｄ）溶剤が、Ｎ，Ｎ－ジメチルホルムアミド、Ｎ－メチル－２－ピロリドン、Ｎ－エチル－２－ピロリドン、Ｎ，Ｎ－ジメチルアセトアミド、ジメチルスルホキシド、ジエチレングリコールジメチルエーテル、シクロペンタノン、γ－ブチロラクトン、α－アセチル－γ－ブチロラクトン、テトラメチル尿素、１，３－ジメチル－２－イミダゾリノン、Ｎ－シクロヘキシル－２－ピロリドン、及び２－オクタノンからなる群から選択される一つ又は複数の化合物を含む、項目１～４のいずれか１項に記載の感光性樹脂組成物。
［６］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、２つ以上の重合性不飽和結合を有する、項目１～５のいずれか１項に記載の感光性樹脂組成物。
［７］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、エポキシ樹脂と（メタ）アタクリル酸との反応物である、項目１～５のいずれか１項に記載の感光性樹脂組成物。
［８］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、下記一般式（３）または（４）で表される、項目１～５のいずれか１項に記載の感光性樹脂組成物。

｛式（３）中、Ｒ_１は、炭素数１～４０の１価の有機基である。｝

｛式（４）中、Ｒ_２は、炭素数１～４０の１価の有機基である。｝
［９］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、下記一般式（５）または（６）で表される、項目１～５のいずれか１項に記載の感光性樹脂組成物。

｛式（５）中、Ｒ_３は、炭素数１～４０の１価の有機基である。｝

｛式（６）中、Ｒ_４は、炭素数１～４０の１価の有機基である。｝
［１０］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、下記一般式（７）で表される化合物を含む、項目１～５のいずれか１項に記載の感光性樹脂組成物。

｛式（７）中、Ｒ₂は、炭素数１～４０の２価の有機基である。｝
［１１］
上記（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物が、下記一般式（８）で表される化合物を含む、項目１～５のいずれか１項に記載の感光性樹脂組成物。

｛式（８）中、Ｒ₆は、炭素数１～４０の２価の有機基である。｝
［１２］
（Ａ）ポリイミド前駆体と、
（Ｂ）ヒドロキシル基及び重合性不飽和結合を有する化合物と、
（Ｃ）感光剤と、
（Ｄ）溶剤と、
（Ｅ）遊離塩素と
を含む感光性樹脂組成物であって、
上記感光性樹脂組成物を、硬化後の膜厚が約１０μｍとなるように回転法で基板上に塗布し、１１０℃で１８０秒間ホットプレートで加熱して硬化させたとき、得られる塗膜に含まれる上記遊離塩素の量が、上記塗膜の全質量を基準として、０．０００１～５ｐｐｍである、感光性樹脂組成物。
［１３］
（Ｇ）エポキシ樹脂を更に含む、項目１～１２のいずれか１項に記載の感光性樹脂組成物。
［１４］
上記（Ｇ）エポキシ樹脂の量は、上記（Ａ）ポリイミド前駆体１００質量部に対して０．１～１０質量部である、項目１３に記載の感光性樹脂組成物。
［１５］
ネガ型感光性樹脂組成物である、項目１～１４のいずれか１項に記載の感光性樹脂組成物。
［１６］
（Ａ）ポリイミド前駆体と、
（Ｂ）ヒドロキシル基及び複数の重合性不飽和結合を有する化合物と、
（Ｃ）感光剤と、
（Ｄ）溶剤と、
（Ｅ）遊離塩素及び／又は共有結合性塩素と、
を含む感光性樹脂組成物であって、
上記感光性樹脂組成物を調整後、２３℃±０．５℃、相対湿度５０％±１０％で３日静置した際の上記感光性樹脂組成物中の全塩素量が、上記感光性樹脂組成物の全質量を基準として０．０００１～２５０ｐｐｍである、感光性樹脂組成物。 The present inventors have found that the above problems can be solved by a resin composition containing a compound having a hydroxyl group and a polymerizable unsaturated bond, and a specific amount of free chlorine and/or covalently bonded chlorine, and have completed the present invention. Examples of embodiments of the present invention are listed below.
[1]
(A) a polyimide precursor;
(B) a compound having a hydroxyl group and a polymerizable unsaturated bond;
(C) a photosensitizer; and
(D) a solvent;
(E) free chlorine;
A photosensitive resin composition comprising:
The amount of the free chlorine is 0.0001 to 2 ppm based on the total mass of the photosensitive resin composition.
[2]
2. The photosensitive resin composition according to item 1, wherein the photosensitizer (C) is a photopolymerization initiator.
[3]
3. The photosensitive resin composition according to item 1 or 2, wherein the polyimide precursor (A) is represented by the following general formula (1):

In formula (1), _X1 is a tetravalent organic group having 6 to 40 carbon atoms, _Y1 is a divalent organic group having 6 to 40 carbon atoms, n1 is an integer from 2 to 150, and _R1 and _R2 are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. However, at least one of _R1 and _R2 is represented by the following general formula (2):

In formula (2), R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and m1 represents an integer of 2 to 10.
[4]
The photosensitive resin composition according to any one of items 1 to 3, comprising 100 to 860 parts by mass of the solvent (D) relative to 100 parts by mass of the polyimide precursor (A).
[5]
The photosensitive resin composition according to any one of items 1 to 4, wherein the (D) solvent comprises one or more compounds selected from the group consisting of N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, and 2-octanone.
[6]
6. The photosensitive resin composition according to any one of items 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond has two or more polymerizable unsaturated bonds.
[7]
6. The photosensitive resin composition according to any one of items 1 to 5, wherein the (B) compound having a hydroxyl group and a polymerizable unsaturated bond is a reaction product of an epoxy resin and (meth)acrylic acid.
[8]
The photosensitive resin composition according to any one of items 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond is represented by the following general formula (3) or (4):

In formula (3), R ₁ is a monovalent organic group having 1 to 40 carbon atoms.

In formula (4), R ₂ is a monovalent organic group having 1 to 40 carbon atoms.
[9]
The photosensitive resin composition according to any one of items 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond is represented by the following general formula (5) or (6):

In formula (5), R ₃ is a monovalent organic group having 1 to 40 carbon atoms.

In formula (6), R ₄ is a monovalent organic group having 1 to 40 carbon atoms.
[10]
The photosensitive resin composition according to any one of items 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond includes a compound represented by the following general formula (7):

In formula (7), R ₂ is a divalent organic group having 1 to 40 carbon atoms.
[11]
The photosensitive resin composition according to any one of items 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond includes a compound represented by the following general formula (8):

In formula (8), R ₆ is a divalent organic group having 1 to 40 carbon atoms.
[12]
(A) a polyimide precursor;
(B) a compound having a hydroxyl group and a polymerizable unsaturated bond;
(C) a photosensitizer; and
(D) a solvent;
(E) a photosensitive resin composition comprising free chlorine,
The photosensitive resin composition is applied onto a substrate by a rotation method so that the film thickness after curing is about 10 μm, and when the composition is cured by heating on a hot plate at 110° C. for 180 seconds, the amount of the free chlorine contained in the resulting coating film is 0.0001 to 5 ppm based on the total mass of the coating film.
[13]
13. The photosensitive resin composition according to any one of items 1 to 12, further comprising (G) an epoxy resin.
[14]
Item 14. The photosensitive resin composition according to item 13, wherein the amount of the epoxy resin (G) is 0.1 to 10 parts by mass per 100 parts by mass of the polyimide precursor (A).
[15]
15. The photosensitive resin composition according to any one of items 1 to 14, which is a negative type photosensitive resin composition.
[16]
(A) a polyimide precursor;
(B) a compound having a hydroxyl group and a plurality of polymerizable unsaturated bonds;
(C) a photosensitizer; and
(D) a solvent;
(E) free chlorine and/or covalently bound chlorine;
A photosensitive resin composition comprising:
A photosensitive resin composition, wherein the total amount of chlorine in the photosensitive resin composition when the photosensitive resin composition is allowed to stand for 3 days at 23°C±0.5°C and a relative humidity of 50%±10% after preparation is 0.0001 to 250 ppm based on the total mass of the photosensitive resin composition.

According to the present invention, it is possible to provide a photosensitive resin composition capable of producing a resin film having a high glass transition temperature and a high thermal weight loss temperature and excellent chemical resistance while maintaining the resolution of the formed relief pattern. In one embodiment, the crosslink density of the polymer in the resin can be improved after the relief pattern is formed, and the glass transition temperature of the cured film tends to be high while maintaining the resolution. In one embodiment, the low boiling point compound in the film can be fixed by reaction, and the thermal weight loss temperature can be improved. Furthermore, in one embodiment, the high crosslink density and the specific amount of free chlorine prevent the intrusion of chemicals into the cured film, and therefore the chemical resistance of the relief pattern can be improved.

The following provides a detailed description of the form for carrying out the present invention (hereinafter, abbreviated as "embodiment"). Note that the present invention is not limited to the following embodiment, and can be carried out in various modifications within the scope of the gist. Throughout this specification, when a plurality of structures represented by the same symbol in a general formula are present in a molecule, they are each independently selected and may be the same or different from each other, unless otherwise specified. Furthermore, structures represented by a common symbol in different general formulas are also each independently selected and may be the same or different from each other, unless otherwise specified.

[Photosensitive resin composition]
The photosensitive resin composition of the present embodiment includes (A) a polyimide precursor, (B) a compound having a hydroxyl group and a polymerizable unsaturated bond, (C) a photosensitizer, (D) a solvent, and (E) a photopolymerizable copolymer. ) a specific amount of free chlorine and/or covalently bound chlorine. Optionally, the photosensitive resin composition contains other components. Each component is described in turn below.

The photosensitive resin composition may be either negative or positive depending on the desired application, and is preferably negative from the viewpoint of the physical properties of the polyimide precursor (A) described below.

｛式（１）中、Ｘ₁は、炭素数６～４０の４価の有機基であり、Ｙ₁は、炭素数６～４０の２価の有機基であり、ｎ_１は、２～１５０の整数であり、Ｒ_１及びＲ_２は、それぞれ独立に、水素原子、又は炭素数１～４０の１価の有機基である。ただし、Ｒ_１及びＲ_２の少なくともいずれかは、下記一般式（２）：

で表される基であり、式（２）中、Ｒ_３、Ｒ_４及びＲ_５は、それぞれ独立に、水素原子又は炭素数１～３の１価の有機基であり、そしてｍ_１は２～１０の整数である。} (A) Polyimide Precursor In this embodiment, (A) the polyimide precursor is a resin component contained in the photosensitive resin composition, and is preferably a polyamide having a structural unit represented by the following general formula (1).

In formula (1), X ₁ is a tetravalent organic group having 6 to 40 carbon atoms, Y ₁ is a divalent organic group having 6 to 40 carbon atoms, n ₁ is an integer from 2 to 150, and R ₁ and R ₂ are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. However, at least one of R ₁ and R ₂ is represented by the following general formula (2):

In formula (2), R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and m ₁ represents an integer of 2 to 10.

The ratio of the monovalent organic group represented by the above general formula (2) to all of R ₁ and R ₂ of the precursor represented by the above general formula (1) contained in the polyimide precursor (A) is preferably 50 mol % to 100 mol % from the viewpoint of high resolution, and more preferably 75 mol % to 100 mol % from the viewpoints of high chemical resistance and sensitivity.

In the above general formula (1), n1 is preferably an integer from 3 to 100, and more preferably an integer from 5 to 70, from the viewpoint of the photosensitive properties and mechanical properties of the photosensitive resin composition.

｛式（２０）中、Ｒ６は水素原子、フッ素原子、Ｃ１～Ｃ１０の炭化水素基、及びＣ１～Ｃ１０の含フッ素炭化水素基から成る群から選ばれる１価の基であり、ｌは０～２から選ばれる整数であり、ｍは０～３から選ばれる整数であり、そしてｎは０～４から選ばれる整数である。｝
で表される構造を有する基が挙げられるが、これらに限定されるものではない。また、Ｘ_１の構造は１種でも２種以上の組み合わせでもよい。上記式（２０）で表される構造を有するＸ_１基は、耐熱性と感光特性とを両立するという点で特に好ましい。 In the above general formula (1), the tetravalent organic group represented by _X1 is preferably an organic group having 6 to 40 carbon atoms, from the viewpoint of achieving both heat resistance and photosensitive properties, and more preferably an aromatic group in which the _-COOR1 group, the _-COOR2 group, and the -CONH- group are in the ortho position relative to each other, or an alicyclic aliphatic group. Specific examples of the tetravalent organic group represented by _X1 include organic groups having 6 to 40 carbon atoms containing an aromatic ring, such as the following general formula (20):

{In formula (20), R6 is a monovalent group selected from the group consisting of a hydrogen atom, a fluorine atom, a C1-C10 hydrocarbon group, and a C1-C10 fluorine-containing hydrocarbon group, l is an integer selected from 0 to 2, m is an integer selected from 0 to 3, and n is an integer selected from 0 to 4.}
Examples of the structure represented by the formula (20) include, but are not limited to, a group having a structure represented by the formula (20). The structure represented by the formula (20 ₎ may be a single type or a combination of two or more types. The group represented by the formula ( ₂₀ ) is particularly preferred in that it has both heat resistance and photosensitive properties.

｛式（２１）中、Ｒ６は水素原子、フッ素原子、Ｃ１～Ｃ１０の炭化水素基、及びＣ１～Ｃ１０の含フッ素炭化水素基から成る群から選ばれる１価の基であり、そしてｎは０～４から選ばれる整数である。｝
で表される構造が挙げられるが、これらに限定されるものではない。また、Ｙ_１の構造は１種でも２種以上の組み合わせでもよい。上記式（２１）で表される構造を有するＹ_１基は、耐熱性及び感光特性を両立するという点で特に好ましい。 In the above general formula (1), the divalent organic group represented by _Y1 is preferably an aromatic group having 6 to 40 carbon atoms in terms of achieving both heat resistance and photosensitive properties, and is, for example, a group represented by the following formula (21):

In formula (21), R6 is a monovalent group selected from the group consisting of a hydrogen atom, a fluorine atom, a C1 to C10 hydrocarbon group, and a C1 to C10 fluorine-containing hydrocarbon group, and n is an integer selected from 0 to 4.
Examples of the structure represented by the formula ( ₂₁ ) include, but are not limited to, the structure represented by the formula (21). The structure represented by the formula (21) may be a single type or a combination of two or more types. The structure represented by the formula ( ₂₁ ) is particularly preferred in that it provides both heat resistance and photosensitive properties.

で表される構造は、低温加熱時のイミド化率、脱ガス性、銅密着性、及び耐薬品性の観点から好ましい。 As the _Y1 group, among the structures represented by the above formula (21), the following formula:

The structure represented by the following formula is preferable from the viewpoints of the imidization rate during low-temperature heating, degassing properties, copper adhesion, and chemical resistance.

In the above general formula (2), _R3 is preferably a hydrogen atom or a methyl group, and _R4 and _R5 are preferably hydrogen atoms from the viewpoint of photosensitive properties. Also, _m1 is an integer of 2 to 10, preferably an integer of 2 to 4, from the viewpoint of photosensitive properties.

｛式（９）中、Ｒ_１、Ｒ_２、及びｎ_１は上記に定義したものである。｝
で表される構造単位を有するポリイミド前駆体を含むことが好ましい。 In one embodiment, the polyimide precursor (A) is represented by the following general formula (9):

In formula (9), R ₁ , R ₂ , and n ₁ are defined above.
It is preferable that the polyimide precursor contains a polyimide precursor having a structural unit represented by the following formula:

In formula (9), at least one of R ₁ and R ₂ is more preferably a monovalent organic group represented by formula (2) above.

｛式（１０）中、Ｒ_１、Ｒ_２、及びｎ_１は上記に定義したものである。｝
で表される構造単位を有するポリイミド前駆体を含むことが好ましい。 In one embodiment, the polyimide precursor (A) is represented by the following general formula (10):

In formula (10), R ₁ , R ₂ , and n ₁ are defined above.
It is preferable that the polyimide precursor contains a polyimide precursor having a structural unit represented by the following formula:

In formula (10), at least one of R ₁ and R ₂ is more preferably a monovalent organic group represented by formula (2) above.

(A) Method for Preparing Polyimide Precursor The polyimide precursor containing the structure represented by the general formula (1) in this embodiment can be obtained, for example, by a method comprising reacting a tetracarboxylic dianhydride containing a tetravalent organic group _X1 having 6 to 40 carbon atoms with (a) an alcohol having a structure in which a monovalent organic group represented by the general formula (2) and a hydroxyl group are bonded, and, if desired, with (b) an alcohol having a structure other than the group represented by the general formula (2) to prepare a partially esterified tetracarboxylic acid (hereinafter, also referred to as an acid/ester body); and subsequently polycondensing the obtained acid/ester body with a diamine containing a divalent organic group _Y1 having 6 to 40 carbon atoms.

(Preparation of Acid/Ester Forms)
In this embodiment, examples of tetracarboxylic dianhydrides containing a tetravalent organic group X ₁ having 6 to 40 carbon atoms include pyromellitic anhydride, diphenylether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, diphenylsulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane, etc. In addition, these can be used alone or in combination of two or more.

(b) Examples of alcohols having a structure other than the group represented by the general formula (2) above include aliphatic alcohols having 5 to 30 carbon atoms or aromatic alcohols having 6 to 30 carbon atoms, such as 1-pentanol, 2-pentanol, 3-pentanol, neopentyl alcohol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 3-octanol, 1-nonanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, and benzyl alcohol.

The content of the organic group of general formula (2) in the polyimide precursor is preferably 50 mol % or more relative to the total content of R ₁ , R ₂ , R ₆ , and R _7. When the content of the organic group of general formula (2) exceeds 50 mol %, it is preferable since desired photosensitive characteristics can be obtained.
The content of the organic group of general formula (2) in the photosensitive resin composition is preferably 75 mol % or more based on the total content of R ₁ , R ₂ , R ₆ , and R ₇ .

By dissolving and mixing the above tetracarboxylic dianhydride and the above alcohol (a) in a reaction solvent in the presence of a basic catalyst such as pyridine, the half-esterification reaction of the acid dianhydride proceeds, and the desired acid/ester body can be obtained. The reaction conditions are preferably a reaction temperature of 20 to 50°C and stirring for 4 to 10 hours.

The reaction solvent is preferably one that dissolves the acid/ester and the polyimide precursor, which is a polycondensation product of the acid/ester and diamines. Examples of reaction solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetramethylurea, gamma butyrolactone, ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, chlorobenzene, o-dichlorobenzene, hexane, heptane, benzene, toluene, and xylene. These may be used alone or in combination as needed.

(Preparation of polyimide precursor)
A known dehydration condensation agent is mixed with the above acid/ester (typically a solution in the above reaction solvent) under ice cooling to convert the acid/ester into a polyacid anhydride, and then a diamine containing a divalent organic group _Y1 having 6 to 40 carbon atoms dissolved or dispersed in a separate solvent is added dropwise to the acid/ester to polycondense, thereby obtaining a polyimide precursor. Examples of the dehydration condensation agent include dicyclohexylcarbodiimide, 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1,1-carbonyldioxy-di-1,2,3-benzotriazole, and N,N'-disuccinimidyl carbonate.

Examples of diamines containing a divalent organic group Y ₁ having 6 to 40 carbon atoms include p-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzo phenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4- bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, ortho-tolidine Also included are sulfone, 9,9-bis(4-aminophenyl)fluorene, and those in which some of the hydrogen atoms on the benzene ring are substituted with a methyl group, an ethyl group, a hydroxymethyl group, a hydroxyethyl group, a halogen, or the like, such as 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethytoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, and mixtures thereof. However, the diamines are not limited to these.

In order to improve the adhesion between the photosensitive resin layer formed on a substrate by applying the photosensitive resin composition of this embodiment onto the substrate and various substrates, diaminosiloxanes such as 1,3-bis(3-aminopropyl)tetramethyldisiloxane and 1,3-bis(3-aminopropyl)tetraphenyldisiloxane can also be copolymerized during preparation of the polyimide precursor (A).

After the polycondensation reaction is completed, the water-absorbing by-product of the dehydrating condensing agent coexisting in the reaction solution may be filtered off as necessary, and then a poor solvent such as water, aliphatic lower alcohol, or a mixture thereof may be added to the reaction solution to precipitate the polymer component. The polymer may be purified by repeating the above-mentioned redissolution and reprecipitation operations. The polymer may then be vacuum-dried to isolate the polyimide precursor. To improve the degree of purification, the polymer solution may be passed through a column packed with an anion and/or cation exchange resin swollen with an appropriate organic solvent to remove ionic impurities.

The molecular weight of the polyimide precursor (A), as measured by gel permeation chromatography in terms of polystyrene equivalent weight average molecular weight, is preferably 8,000 to 150,000, more preferably 9,000 to 50,000, and particularly preferably 18,000 to 40,000. A weight average molecular weight of 8,000 or more is preferable because of good mechanical properties, while a weight average molecular weight of 150,000 or less is preferable because of good dispersibility in the developer and resolution performance of the relief pattern. Tetrahydrofuran and N-methyl-2-pyrrolidone are recommended as developing solvents for gel permeation chromatography. The molecular weight is determined from a calibration curve prepared using standard monodisperse polystyrene. It is recommended to select the standard monodisperse polystyrene from among the organic solvent-based standard samples STANDARD SM-105 manufactured by Showa Denko KK.

｛上記式（３）～（６）中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、炭素数１～４０の１価の有機基である。｝ (B) Compound having hydroxyl group and polymerizable unsaturated bond The compound having hydroxyl group and polymerizable unsaturated bond (hereinafter, also simply referred to as "(B) compound") in this embodiment will be described. The (B) compound has at least one hydroxyl group and at least one polymerizable unsaturated bond in the molecule. The polymerizable unsaturated bond is not limited as long as it is a radically polymerizable functional group, and examples thereof include an acrylic group, a methacrylic group, an acryloyloxy group, a methacryloyloxy group, a vinyl group, and an allyl group, and an acryloyloxy group or a methacryloyloxy group (referred to as "(meth)acryloyloxy group" in this specification) is preferable. The (B) compound having a (meth)acryloyloxy group as a polymerizable unsaturated bond may be a reaction product of acrylic acid or a methacrylic group (referred to as "(meth)acrylic acid" in this specification) with an epoxy resin, or a reaction product of (meth)acrylic acid with a ring-opened epoxy resin. Among these, from the viewpoints of chemical resistance and thermal properties, reaction products of (meth)acrylic acid and epoxy resins, or reaction products of (meth)acrylic acid and ring-opened epoxy resins, represented by the following general formulas (3) to (6) are preferred.

{In the above formulas (3) to (6), R ₁ , R ₂ , R ₃ and R ₄ are monovalent organic groups having 1 to 40 carbon atoms.}

｛上記一般式中、Ｒ₂、Ｒ_３は、炭素数１～４０の２価の有機基である。｝
で表される化合物が挙げられる。 The compound (B) may have one, two or more, or three or more polymerizable unsaturated bonds in the same molecule. When the compound (B) has two polymerizable unsaturated bonds, the compound (B) may have a polymerizable unsaturated bond represented by the following general formula:

{In the above general formula, R ₂ and R ₃ are divalent organic groups having 1 to 40 carbon atoms.}
Examples of the compound include compounds represented by the following formula:

More specifically, examples of the compound (B) having two polymerizable unsaturated bonds include, but are not limited to, the following compound groups:

｛上記式中、Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は、それぞれ独立して、炭素数１～４０の２価の有機基である。｝で表される化合物が挙げられる。これらの中でも、下記一般式：

｛上記式（８）中、Ｒ_６は、炭素数１～４０の２価の有機基である。｝で表される化合物が好ましい。 The compound (B) having two or more polymerizable unsaturated bonds can be produced by reacting (meth)acrylic acid with a bifunctional or higher epoxy resin. In this case, a compound having a monofunctional or higher oxacyclopropyl group in the molecule may be produced as a reaction impurity. The reaction impurity may be a compound represented by the following general formula:

{In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a divalent organic group having 1 to 40 carbon atoms.} Among these, compounds represented by the following general formula:

In the above formula (8), R ₆ is a divalent organic group having 1 to 40 carbon atoms.

When the compound (B) has one polymerizable unsaturated bond, examples of the compound include, but are not limited to, the following compounds:

(B) Method for preparing a compound having a hydroxyl group and a polymerizable unsaturated bond The method for producing the compound (B) is not particularly limited as long as a compound having at least one hydroxyl group and at least one polymerizable unsaturated bond in the molecule can be obtained. From the viewpoint of adjusting the amount of free chlorine and/or covalently bonded chlorine to a specific amount, the compound (B) is preferably a compound derived from an epoxy resin. For example, the compound (B) can be produced by reacting a compound having a polymerizable unsaturated bond with an epoxy resin or a ring-opened product thereof. Preferably, the compound (B) may be produced by adding a basic catalyst and a polymerization inhibitor to an epoxy resin or a ring-opened product thereof to obtain a solution, adding methacrylic acid or acrylic acid to the solution, and reacting the solution. The reaction may be continued, for example, at 100° C. until the acid value becomes equal to or less than a certain value. After synthesis, the mixture is stirred in a mixed phase with an anion exchange resin for one day, and then filtered to obtain the compound (B). As the anion exchange resin, for example, IRA96SB can be used.

The epoxy resin used in the synthesis reaction of the compound (B) includes, but is not limited to, a structure represented by the following general formula:

｛上記式中、Ｒ_１及びＲ_２は、それぞれ独立して、炭素数１～４０の１価の有機基である。｝
で表される構造に変換された化合物であることが好ましい。 The ring-opened epoxy resin used in the synthesis reaction of the compound (B) is a ring-opened epoxy resin represented by the following general formula:

In the above formula, R ₁ and R ₂ are each independently a monovalent organic group having 1 to 40 carbon atoms.
It is preferable that the compound is a compound having a structure represented by the formula:

The photosensitive resin composition of the present embodiment contains the above-mentioned (B) compound, and thus can provide a resin film having a high glass transition temperature and a high thermal weight loss temperature while maintaining storage stability, and further having excellent chemical resistance. Without being bound by theory, it is believed that the reason for the increase in glass transition temperature is that the polymerizable unsaturated bonds that remain unpolymerized during exposure undergo an addition reaction with hydroxyl groups during high-temperature curing, resulting in a cured film that is crosslinked at a higher density than that of a normal polymerizable unsaturated bond-containing compound, and thus impeding the movement of the polymer that constitutes the resin. In addition, when the polymerizable unsaturated bond is a (meth)acrylic group, a Michael addition reaction proceeds. As for the reason for the improvement in chemical resistance, it is believed that the high crosslink density similarly reduces the solubility in chemicals, and that the amount of free chlorine and/or covalently bonded chlorine within a specific range suppresses the formation of ion pairs with chemicals that have a dissolution-promoting effect, thereby improving chemical resistance. The reason why the thermal weight loss temperature rises is thought to be that the polymerizable unsaturated bonds and hydroxyl groups undergo an addition reaction with the side chains of the polyimide precursor, which is a factor in lowering the thermal weight loss temperature, especially during low-temperature curing. Even when the temperature is raised above the curing temperature, the components derived from the side chains of the polyimide precursor do not volatilize but remain, preventing weight loss due to heating.

When a bifunctional or higher epoxy resin is used to synthesize compound (B), compound (B) may have unreacted epoxy groups. In this case, anionic polymerization proceeds with hydroxyl groups as the initiator during thermal curing, further increasing the crosslink density.

The amount of compound (B) is 1 to 60 parts by weight per 100 parts by weight of polyimide precursor (A), preferably 1 to 30 parts by weight from the viewpoint of storage stability, and more preferably 4 to 20 parts by weight from the viewpoint of resolution.

(C) Photosensitizer The photosensitive resin composition of the present embodiment contains a photosensitizer. In one embodiment, the photosensitizer may be a photopolymerization initiator. The photopolymerization initiator is preferable because it promotes curing of the relief pattern by light irradiation. The photopolymerization initiator is preferably a photoradical polymerization initiator, and examples of the photopolymerization initiator include benzophenone, o-benzoyl methyl benzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone and other benzophenone derivatives, 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone and other acetophenone derivatives, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, diethylthioxanthone and other thioxanthone derivatives, benzyl derivatives, benzil, benzil dimethyl ketal, benzyl-β-methoxyethyl acetal and other benzyl derivatives, benzoin, benzoin methyl ether and other benzoin derivatives, 1-phenyl-1,2-butanedione-2-(o-methoxy Preferred examples of the photopolymerization initiator include, but are not limited to, oximes such as 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, and 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime, N-arylglycines such as N-phenylglycine, peroxides such as benzoyl perchloride, aromatic biimidazoles, titanocenes, and photoacid generators such as α-(n-octanesulfonyloxyimino)-4-methoxybenzyl cyanide. Of the above photopolymerization initiators, oximes are more preferred, particularly in terms of photosensitivity.

The amount of the photopolymerization initiator is preferably 0.1 parts by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 8 parts by mass or less, relative to 100 parts by mass of the polyimide precursor (A). The amount is preferably 0.1 parts by mass or more from the viewpoint of photosensitivity or patterning property, and 20 parts by mass or less from the viewpoint of the physical properties of the photosensitive resin layer after curing of the photosensitive resin composition.

(D) Solvent The photosensitive resin composition of this embodiment contains a solvent. As the solvent, it is preferable to use a polar organic solvent from the viewpoint of solubility in the polyimide precursor (A). Specific examples of the solvent include N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, and 2-octanone, which can be used alone or in combination of two or more.

The above solvent can be used in an amount ranging from, for example, 30 parts by mass to 1500 parts by mass, preferably 100 parts by mass to 1000 parts by mass, and more preferably 100 parts by mass to 860 parts by mass, per 100 parts by mass of the polyimide precursor (A), depending on the desired coating thickness and viscosity of the photosensitive resin composition.

From the viewpoint of improving the storage stability of the photosensitive resin composition, a solvent containing an alcohol is preferred. The alcohol that can be suitably used is typically an alcohol that has an alcoholic hydroxyl group in the molecule and does not have an olefinic double bond. Specific examples include alkyl alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and tert-butyl alcohol; lactate esters such as ethyl lactate; propylene glycol monoalkyl ethers such as propylene glycol-1-methyl ether, propylene glycol-2-methyl ether, propylene glycol-1-ethyl ether, propylene glycol-2-ethyl ether, propylene glycol-1-(n-propyl) ether, and propylene glycol-2-(n-propyl) ether; monoalcohols such as ethylene glycol methyl ether, ethylene glycol ethyl ether, and ethylene glycol-n-propyl ether; 2-hydroxyisobutyric acid esters; and dialcohols such as ethylene glycol and propylene glycol. Of these, lactate esters, propylene glycol monoalkyl ethers, 2-hydroxyisobutyrate esters, and ethyl alcohol are preferred, with ethyl lactate, propylene glycol-1-methyl ether, propylene glycol-1-ethyl ether, and propylene glycol-1-(n-propyl) ether being particularly preferred.

When the solvent contains an alcohol that does not have an olefinic double bond, the content of the alcohol that does not have an olefinic double bond in the total solvent is preferably 5% by mass to 50% by mass, and more preferably 10% by mass to 30% by mass, based on the mass of the total solvent. When the content of the alcohol that does not have an olefinic double bond is 5% by mass or more, the storage stability of the photosensitive resin composition is good, while when it is 50% by mass or less, the solubility of the (A) polyimide precursor is good, which is preferable.

(E) Free Chlorine and/or Covalently Bonded Chlorine The photosensitive resin composition of the present embodiment contains chlorine in the form of free chlorine and/or covalently bonded chlorine. The term "free chlorine" refers to anionized chlorine, and the term "covalently bonded chlorine" refers to chlorine that is present in a molecule by forming a covalent bond.

In one embodiment, the amount of free chlorine is 0.0001 to 10 ppm, preferably 0.0001 to 5 ppm, more preferably 0.0001 to 2.0 ppm, and even more preferably 0.0001 to 0.5 ppm, based on the total mass of the photosensitive resin composition. In another embodiment, when the photosensitive resin composition is applied to a substrate by a rotation method so that the thickness of the resin film after curing is about 10 μm, and the composition is cured by heating on a hot plate at 110° C. for 180 seconds, the amount of free chlorine contained in the resulting coating film is 0.0001 to 15 ppm, preferably 0.0001 to 10 ppm, more preferably 0.0001 to 5 ppm, and even more preferably 0.0001 to 0.8 ppm, based on the total mass of the coating film. In yet another embodiment, the total amount of chlorine in the photosensitive resin composition (total amount of free chlorine and covalently bonded chlorine) after the photosensitive resin composition is prepared and left to stand for 3 days at 23°C±0.5°C and a relative humidity of 50%±10% is 0.0001 to 600 ppm, preferably 0.0001 to 420 ppm, more preferably 0.0001 to 250 ppm, and even more preferably 0.0001 to 40 ppm based on the total mass of the photosensitive resin composition.

The source of chlorine is not limited, and for example, the photosensitive resin composition can adjust the amount of chlorine within the above range by including a compound capable of generating free chlorine and/or a compound having covalently bonded chlorine. In general, epoxy resins contain a lot of chlorine in the form of free chlorine and/or covalently bonded chlorine in the resin, derived from epichlorohydrin, which is the raw material of the epoxy resin. Therefore, when the (B) compound is a compound derived from an epoxy resin, chlorine is included in the (B) compound, and as a result, chlorine is also included in the photosensitive resin composition, so it is easier to adjust the amount of chlorine within the above range. However, in the past, when a (B) compound derived from an epoxy resin was used in this way, the amount of chlorine was much greater than the above amount. Since the presence of such chlorine has been tolerated in the past, those skilled in the art have not paid attention to the amount of chlorine. However, the inventors have found that in a preferred embodiment of the present invention, when a (B) compound derived from an epoxy resin is used, it is preferable to remove the chlorine present in the compound and appropriately control the amount of chlorine.

The method for removing chlorine present in the (B) compound derived from the epoxy resin is not particularly limited. For example, chlorine can be removed by stirring the (B) compound in a mixed phase with an anion exchange resin. An example of an anion exchange resin used for removing chlorine is IRA96SB, but is not limited to this.

Other Components The photosensitive resin composition of the present embodiment may further contain components other than the above components (A) to (E). Examples of the other components include (A) a resin component other than the polyimide precursor, a sensitizer, (F) a monomer having a photopolymerizable unsaturated bond other than the compound (B), a bonding aid, (G) an epoxy resin, a thermal polymerization inhibitor, an azole compound, a hindered phenol compound, and an organic titanium compound.

The photosensitive resin composition may further contain an epoxy resin (G) from the viewpoint of obtaining a cured film with a high degree of crosslinking. The amount of the epoxy resin (G) is preferably 0.01 to 25 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polyimide precursor (A). When using a compound (B) derived from an epoxy resin, the raw epoxy resin may be included in the photosensitive resin composition, making it easier to adjust the amount of the epoxy resin to the above range.

In one embodiment, the photosensitive resin composition may further contain a resin component other than the polyimide precursor (A). Examples of resin components that can be contained in the photosensitive resin composition include polyimide, polyoxazole, polyoxazole precursor, phenolic resin, polyamide, epoxy resin, siloxane resin, and acrylic resin. The amount of these resin components is preferably in the range of 0.01 parts by mass to 20 parts by mass per 100 parts by mass of the polyimide precursor (A).

(A) When preparing a positive-type photosensitive resin composition using a polyoxazole precursor together with a polyimide precursor, a compound having a quinone diazide group, such as a compound having a 1,2-benzoquinone diazide structure or a 1,2-naphthoquinone diazide structure, may be used in combination as a positive-type photosensitive material.

In one embodiment, the photosensitive resin composition may optionally contain a sensitizer to improve photosensitivity. Examples of the sensitizer include Michler's ketone, 4,4'-bis(diethylamino)benzophenone, 2,5-bis(4'-diethylaminobenzal)cyclopentane, 2,6-bis(4'-diethylaminobenzal)cyclohexanone, 2,6-bis(4'-diethylaminobenzal)-4-methylcyclohexanone, 4,4'-bis(dimethylamino)chalcone, 4,4'-bis(diethylamino)chalcone, p-dimethylaminocinnamylidene indole, and the like. Non, p-dimethylaminobenzylidene indanone, 2-(p-dimethylaminophenylbiphenylene)-benzothiazole, 2-(p-dimethylaminophenylvinylene)benzothiazole, 2-(p-dimethylaminophenylvinylene)isonaphthothiazole, 1,3-bis(4'-dimethylaminobenzal)acetone, 1,3-bis(4'-diethylaminobenzal)acetone, 3,3'-carbonyl-bis(7-diethylaminocoumarin), 3-acetone ethyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7-dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, 3-ethoxycarbonyl-7-diethylaminocoumarin, N-phenyl-N'-ethylethanolamine, N-phenyldiethanolamine, N-p-tolyldiethanolamine, N-phenylethanolamine, 4-morpholinobenzophenone, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 2-mercaptobenzimidazole, 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, 2-(p-dimethylaminobenzoyl)styrene, and the like. These can be used alone or in combination of multiple types (e.g., 2 to 5 types).

The amount of sensitizer to be added is preferably 0.1 to 25 parts by weight per 100 parts by weight of (A) polyimide precursor.

In one embodiment, in order to improve the resolution of the relief pattern, the photosensitive resin composition may optionally contain (F) a monomer other than the compound (B) having a photopolymerizable unsaturated bond. As such a monomer, a (meth)acrylic compound that undergoes a radical polymerization reaction with a photopolymerization initiator is preferable, and examples thereof include, but are not limited to, mono- or diacrylates and methacrylates of ethylene glycol or polyethylene glycol, including diethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate, mono- or diacrylates and methacrylates of propylene glycol or polypropylene glycol, mono-, di- or triacrylates and methacrylates of glycerol, cyclohexane diacrylate and dimethacrylate, diacrylates and dimethacrylates of 1,4-butanediol, 1,6-hexafluoropropanediol, and 1,6-hexafluoropropanediol. Examples of such compounds include diacrylate and dimethacrylate of Sandiol, diacrylate and dimethacrylate of neopentyl glycol, mono- or diacrylate and methacrylate of bisphenol A, benzene trimethacrylate, isobornyl acrylate and methacrylate, acrylamide and its derivatives, methacrylamide and its derivatives, trimethylolpropane triacrylate and methacrylate, di- or triacrylate and methacrylate of glycerol, di-, tri-, or tetraacrylate and methacrylate of pentaerythritol, and ethylene oxide or propylene oxide adducts of these compounds.

The amount of the monomer having a photopolymerizable unsaturated bond is preferably 1 to 50 parts by mass per 100 parts by mass of the polyimide precursor (A).

In one embodiment, the photosensitive resin composition may optionally contain an adhesion aid to improve adhesion between the film formed using the photosensitive resin composition and the substrate. Examples of the adhesion aid include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalamine, and the like. Examples of such additives include silane coupling agents such as benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, and N-phenylaminopropyl trimethoxysilane, as well as aluminum-based adhesion promoters such as aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), and ethylacetoacetate aluminum diisopropylate.

Among these adhesive aids, it is more preferable to use a silane coupling agent in terms of adhesive strength. The amount of adhesive aid to be added is preferably in the range of 0.5 to 25 parts by mass per 100 parts by mass of (A) polyimide precursor.

In one embodiment, the photosensitive resin composition may optionally contain a thermal polymerization inhibitor in order to improve the stability of the viscosity and photosensitivity of the photosensitive resin composition, particularly during storage in a state of a solution containing a solvent. Examples of the thermal polymerization inhibitor include hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt.

The amount of thermal polymerization inhibitor to be added is preferably in the range of 0.005 parts by mass to 12 parts by mass per 100 parts by mass of (A) polyimide precursor.

For example, when a substrate made of copper or a copper alloy is used, the photosensitive resin composition may optionally contain an azole compound in order to suppress discoloration of the substrate. Examples of the azole compound include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-t-butyl-5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, phenyltriazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, hydroxyphenyltriazole, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 1H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, and the like. benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, 1-methyl-1H-tetrazole, etc. Particularly preferred are tolyltriazole, 5-methyl-1H-benzotriazole, and 4-methyl-1H-benzotriazole. These azole compounds may be used alone or in a mixture of two or more.

The amount of the azole compound is preferably 0.1 to 20 parts by mass per 100 parts by mass of the polyimide precursor (A), and more preferably 0.5 to 5 parts by mass from the viewpoint of photosensitivity characteristics. When the amount of the azole compound per 100 parts by mass of the polyimide precursor (A) is 0.1 part by mass or more, discoloration of the copper or copper alloy surface is suppressed when the photosensitive resin composition is formed on copper or a copper alloy, while when the amount is 20 parts by mass or less, photosensitivity is excellent, which is preferable.

In this embodiment, in order to suppress discoloration on copper, the photosensitive resin composition may contain a hindered phenol compound. Examples of the hindered phenol compound include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butyl-hydroquinone, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-thio-bis(3-methyl-6-t-butylphenol), 4,4'-butylyl 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrogen) rosinamide), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1 ,3,5-tris(3-hydroxy-2,6-dimethyl-4-isopropylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-s-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-t lion, 1,3,5-tris[4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-triazine-2,4,6- (1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5,6-trimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1, 3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy- 2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, etc., but are not limited thereto. Among these, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione is particularly preferred.

The amount of the hindered phenol compound is preferably 0.1 to 20 parts by mass per 100 parts by mass of the polyimide precursor (A), and more preferably 0.5 to 10 parts by mass from the viewpoint of photosensitivity characteristics. When the amount of the hindered phenol compound per 100 parts by mass of the polyimide precursor (A) is 0.1 part by mass or more, for example, when the photosensitive resin composition is formed on copper or a copper alloy, discoloration and corrosion of the copper or copper alloy is prevented, while when the amount is 20 parts by mass or less, photosensitivity is excellent, which is preferable.

In one embodiment, the photosensitive resin composition may contain an organotitanium compound. By containing an organotitanium compound, a photosensitive resin layer having excellent chemical resistance can be formed even when cured at a low temperature of about 250°C.

Examples of organotitanium compounds that can be used include those in which an organic chemical is bonded to a titanium atom via a covalent or ionic bond.

Specific examples of the organotitanium compound are shown below in I) to VII):
I) As the titanium chelate compound, a titanium chelate having two or more alkoxy groups is more preferable because it provides the storage stability of the photosensitive resin composition and a good pattern. Specific examples of the titanium chelate compound include titanium bis(triethanolamine)diisopropoxide, titanium di(n-butoxide)bis(2,4-pentanedionate), titanium diisopropoxide bis(2,4-pentanedionate), titanium diisopropoxide bis(tetramethylheptanedionate), titanium diisopropoxide bis(ethylacetoacetate), etc.

II) Examples of tetraalkoxytitanium compounds include titanium tetra(n-butoxide), titanium tetraethoxide, titanium tetra(2-ethylhexoxide), titanium tetraisobutoxide, titanium tetraisopropoxide, titanium tetramethoxide, titanium tetramethoxypropoxide, titanium tetramethylphenoxide, titanium tetra(n-nonyloxide), titanium tetra(n-propoxide), titanium tetrastearyloxide, and titanium tetrakis[bis{2,2-(allyloxymethyl)butoxide}].

III) Examples of titanocene compounds include pentamethylcyclopentadienyltitanium trimethoxide, bis(η ⁵ -2,4-cyclopentadiene-1-yl)bis(2,6-difluorophenyl)titanium, and bis(η ⁵ -2,4-cyclopentadiene-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium.

IV) Examples of monoalkoxytitanium compounds include titanium tris(dioctylphosphate) isopropoxide, titanium tris(dodecylbenzenesulfonate) isopropoxide, etc.

V) Examples of titanium oxide compounds include titanium oxide bis(pentanedionate), titanium oxide bis(tetramethylheptanedionate), phthalocyanine titanium oxide, etc.

VI) Examples of titanium tetraacetylacetonate compounds include titanium tetraacetylacetonate.

VII) Examples of titanate coupling agents include isopropyl tridodecylbenzenesulfonyl titanate, etc.

Among the above I) to VII), the organic titanium compound is preferably at least one compound selected from the group consisting of the above I) titanium chelate compounds, II) tetraalkoxytitanium compounds, and III) titanocene compounds, from the viewpoint of exhibiting better chemical resistance. In particular, titanium diisopropoxide bis(ethylacetoacetate), titanium tetra(n-butoxide), and bis(η ⁵ -2,4-cyclopentadiene-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium are preferred.

When an organic titanium compound is blended, the blending amount is preferably 0.05 parts by mass to 10 parts by mass, and more preferably 0.1 parts by mass to 2 parts by mass, per 100 parts by mass of the (A) resin. When the blending amount is 0.05 parts by mass or more, good heat resistance and chemical resistance are exhibited, while when the blending amount is 10 parts by mass or less, excellent storage stability is obtained, which is preferable.

A compound having a similar structure to the imidization accelerator (a compound exhibiting basicity) may be introduced into the polymer side chain. In this way, a higher imidization rate can be obtained than when the imidization accelerator is used as an additive, and a photosensitive resin composition that combines storage stability and chemical resistance can be obtained.

It is preferable that the photosensitive resin composition has a viscosity change rate of within 5% compared to the initial viscosity when the resin composition is stored for 4 weeks at a temperature of 23°C and a humidity of 50% Rh. Furthermore, it is preferable that the photosensitive resin composition has an imidization rate of 70% or more when the resin composition is heated at 170°C for 2 hours to obtain a cured coating film, and it is more preferable that the imidization rate of the cured coating film is 85% or more. Thus, in one embodiment, the photosensitive resin composition can provide a polyimide with a high imidization rate and excellent storage stability and chemical resistance.

｛一般式（１１）中、Ｘ^１及びＹ^１は、一般式（１）中のＸ_１及びＹ_１と同じであり、ｍは正の整数である。｝
一般式（１）中の好ましいＸ_１とＹ_１は、同じ理由により、一般式（１１）のポリイミドにおいても好ましい。一般式（１１）の繰り返し単位数ｍは、特に限定は無いが、２～１５０の整数であってもよい。
本発明によれば、上記で説明された感光性樹脂組成物をポリイミドに変換する工程を含む、ポリイミドの製造方法も提供することができる。 [Polyimide]
The structure of the polyimide contained in the cured relief pattern formed from the polyimide precursor composition is preferably represented by the following general formula (11).

{In general formula (11), ^X1 and ^Y1 are the same as _X1 and _Y1 in general formula (1), and m is a positive integer.}
For the same reason, the preferred _X1 and _Y1 in the general formula (1) are also preferred in the polyimide of the general formula (11). The number m of repeating units in the general formula (11) is not particularly limited, but may be an integer of 2 to 150.
According to the present invention, there can also be provided a method for producing a polyimide, which includes a step of converting the above-described photosensitive resin composition into a polyimide.

[Cured relief pattern]
According to the present invention, it is possible to provide a cured relief pattern using the above-described photosensitive resin composition, and a method for producing the same. In one embodiment, the method for producing the cured relief pattern includes the following steps (1) to (4):
(1) applying the photosensitive resin composition according to the present embodiment onto a substrate to form a photosensitive resin layer on the substrate;
(2) a step of exposing the photosensitive resin layer to light;
(3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) heat-treating the relief pattern to form a hardened relief pattern.

Each step will be described below.
(1) Step of applying the photosensitive resin composition of the present embodiment onto a substrate to form a photosensitive resin layer on the substrate In this step, the photosensitive resin composition of the present embodiment is applied onto a substrate, and then dried as necessary to form a photosensitive resin layer. As the application method, a method that has been conventionally used for applying a photosensitive resin composition, such as a method of applying with a spin coater, a bar coater, a blade coater, a curtain coater, a screen printer, etc., or a method of spray application with a spray coater, etc., can be used.

If necessary, the coating film made of the photosensitive resin composition can be dried, and examples of the drying method include air drying, heat drying in an oven or on a hot plate, and vacuum drying. It is desirable to dry the coating film under conditions that do not cause imidization of the (A) polyimide precursor in the photosensitive resin composition. Specifically, when air drying or heat drying is performed, drying can be performed at 20°C to 140°C for 1 minute to 1 hour. In this manner, a photosensitive resin layer can be formed on the substrate.

(2) Step of Exposing the Photosensitive Resin Layer In this step, the photosensitive resin layer formed in the above step (1) is exposed to an ultraviolet light source or the like through a photomask or reticle having a pattern, or directly, using an exposure device such as a contact aligner, a mirror projection, or a stepper.

After this, for the purpose of improving the photosensitivity, etc., a post-exposure bake (PEB) and/or a pre-development bake may be performed at any combination of temperature and time as necessary. The range of baking conditions is preferably a temperature of 40°C to 120°C and a time of 10 seconds to 240 seconds, but is not limited to this range as long as it does not impair the various properties of the negative photosensitive resin composition.

(3) Step of developing the exposed photosensitive resin layer to form a relief pattern In this step, when the photosensitive resin composition is a negative type, the unexposed portion of the exposed photosensitive resin layer is developed and removed. As a development method for developing the exposed (irradiated) photosensitive resin layer, any method can be selected from conventionally known photoresist development methods, such as a rotary spray method, a paddle method, and a dipping method accompanied by ultrasonic treatment. After development, for the purpose of adjusting the shape of the relief pattern, post-development baking may be performed at any combination of temperature and time, as necessary. As a developer used for development, for example, a good solvent for the negative photosensitive resin composition, or a combination of the good solvent and a poor solvent is preferable. As a good solvent, for example, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, etc. are preferable. As the poor solvent, for example, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate, water, etc. are preferable. When a good solvent and a poor solvent are used in combination, it is preferable to adjust the ratio of the poor solvent to the good solvent depending on the solubility of the polymer in the negative photosensitive resin composition. In addition, two or more kinds of each solvent, for example, several kinds, can be used in combination.

(4) Step of Heating the Relief Pattern to Form a Hardened Relief Pattern In this step, the relief pattern obtained by the above development is heated to disperse the photosensitive component and also imidize the polyimide precursor (A) to convert it into a hardened relief pattern made of polyimide. As a method of heat hardening, various methods can be selected, such as a method using a hot plate, an oven, or a method using a temperature-elevating oven that can be set to a temperature program. Heating can be performed, for example, under conditions of 170°C to 400°C for 30 minutes to 5 hours. As the atmospheric gas during heat hardening, air may be used, or an inert gas such as nitrogen or argon may also be used.

[Semiconductor device]
The photosensitive resin composition of the present embodiment can also provide a semiconductor device having a cured relief pattern obtained by the above-mentioned method for producing a cured relief pattern. Thus, a semiconductor device can be provided having a substrate that is a semiconductor element and a cured relief pattern of polyimide formed on the substrate by the above-mentioned method for producing a cured relief pattern. The present invention can also be applied to a method for producing a semiconductor device that uses a semiconductor element as the substrate and includes the above-mentioned method for producing a cured relief pattern as part of the process. The semiconductor device of the present invention can be produced by forming the cured relief pattern formed by the above-mentioned method for producing a cured relief pattern as a surface protective film, an interlayer insulating film, an insulating film for rewiring, a protective film for a flip chip device, or a protective film for a semiconductor device having a bump structure, and combining the method with a known method for producing a semiconductor device.

[Display device]
The photosensitive resin composition of the present embodiment can also provide a display device comprising a display element and a cured film provided on the upper portion of the display element, the cured film being the above-mentioned cured relief pattern. Here, the cured relief pattern may be laminated in direct contact with the display element, or may be laminated with another layer sandwiched therebetween. For example, the cured film can be a surface protective film, an insulating film, and a planarizing film for a TFT liquid crystal display element and a color filter element, a protrusion for an MVA type liquid crystal display device, and a partition wall for a cathode of an organic EL element.

In addition to being applicable to the semiconductor devices described above, the photosensitive resin composition of the present invention is also useful for applications such as interlayer insulation in multilayer circuits, cover coats for flexible copper-clad boards, solder resist films, and liquid crystal alignment films.

The present embodiment will be described in detail below with reference to examples, but the present embodiment is not limited thereto. In the examples, comparative examples, and production examples, the physical properties of the photosensitive resin composition were measured and evaluated according to the following methods.

[Measurement and evaluation methods]
(1) Weight-average molecular weight The weight-average molecular weight (Mw) of each resin was measured by gel permeation chromatography (standard polystyrene equivalent). The column used in the measurement was a "Shodex 805M/806M series" manufactured by Showa Denko K.K., the standard monodisperse polystyrene was "Shodex STANDARD SM-105" manufactured by Showa Denko K.K., the developing solvent was N-methyl-2-pyrrolidone, and the detector was "Shodex RI-930" manufactured by Showa Denko K.K.

(2) Measurement of the amount of free chlorine in the resin composition After preparing the photosensitive resin composition, the composition was left to stand for 3 days at room temperature (23.0°C ± 0.5°C, relative humidity 50% ± 10%), and then the amount of free chlorine in the resin composition was measured. The ion concentration was measured at 23.0°C using ThermoFicher ICS-3000. Based on the measurement results, the content of chlorine ions in the resin composition was calculated under the following measurement conditions.
2 g of the photosensitive resin composition was weighed out, added to 4 mL of NMP, and stirred for 10 minutes with a shaker to dissolve. 30 mL of ion-exchanged water was added, stirred for 10 minutes with a shaker, and the insoluble matter was removed with a centrifuge (CF15RN manufactured by Himac Co., Ltd.), and the mixture was filtered with a disk filter (JP050AN manufactured by DISMIC Co., Ltd.) and used. 1 mL of the treated sample solution was automatically inserted into the column by the autosampler.
・ Guard column for anion analysis: IonPac AS4A-SC (4 mm x 250 mm)
Guard column pump flow rate: 0.500 mL/min
・Anion analysis separation column: IonPac AS4A-SZ (4mm x 50mm)
Sample introduction line pump flow rate: 0.500 mL/min
・Negative ion chemical suppressor: ACRS-500 (for 4 mm)

(3) Measurement of the amount of free chlorine in the cured polyimide coating film The photosensitive resin composition was spin-coated on a 6-inch silicon wafer so that the film thickness after curing was about 10 μm, and heated on a hot plate at 110° C. for 180 seconds to obtain a cured polyimide coating film. The film thickness was measured using a film thickness measuring device, Lambda Ace (manufactured by Dainippon Screen Co., Ltd.). The amount of free chlorine in the obtained polyimide coating film was measured under the following measurement conditions.
2 g of polyimide coating film was weighed, added to 4 mL of NMP, and stirred for 10 minutes with a shaker to dissolve. 30 mL of ion-exchanged water was added, stirred for 10 minutes with a shaker, and insoluble matter was removed with a centrifuge (CF15RN manufactured by Himac Co., Ltd.) and filtered with a disk filter (JP050AN manufactured by DISMIC Co., Ltd.) for use. 1 mL of the treated sample solution was automatically inserted into the column by the autosampler.
・ Guard column for anion analysis: IonPac AS4A-SC (4 mm x 250 mm)
Guard column pump flow rate: 0.500 mL/min
・Anion analysis separation column: IonPac AS4A-SZ (4mm x 50mm)
Sample introduction line pump flow rate: 0.500 mL/min
・Negative ion chemical suppressor: ACRS-500 (for 4 mm)

(4) Measurement of Glass Transition Temperature of Cured Polyimide Coating Film A photosensitive resin composition was spin-coated on a 6-inch silicon wafer so that the film thickness after curing was about 10 μm, and the wafer was pre-baked on a hot plate at 110° C. for 180 seconds. The wafer was then heated at 170° C. for 2 hours in a nitrogen atmosphere using a temperature-programmable cure oven (VF-000 model, manufactured by Koyo Lindberg Co., Ltd.) to obtain a cured polyimide coating film. The film thickness was measured using a film thickness measuring device, Lambda Ace (manufactured by Dainippon Screen Co., Ltd.). The obtained polyimide coating film was taken out in a rectangular shape and measured with a thermomechanical testing device (Shimadzu Corporation TMA-50) at a load of 200 g/mm ² , a heating rate of 10° C./min, and a range of 20 to 500° C. The glass transition temperature (Tg) was determined as the intersection of the tangents to the thermal yield point of the polyimide film in the measurement chart with temperature on the horizontal axis and displacement on the vertical axis.

(5) Measurement of thermal weight loss temperature (5% weight loss temperature) of cured polyimide coating film A photosensitive resin composition was spin-coated on a 6-inch silicon wafer so that the film thickness after curing was about 10 μm, and the composition was pre-baked on a hot plate at 110° C. for 180 seconds, and then heated at 170° C. for 2 hours in a nitrogen atmosphere using a temperature-programmable cure oven (VF-2000 type, manufactured by Koyo Lindberg Co., Ltd.) to obtain a cured polyimide coating film. The film thickness was measured using a film thickness measuring device, Lambda Ace (manufactured by Dainippon Screen Co., Ltd.). The obtained polyimide coating film was scraped off, and the temperature at which the weight of the film was reduced by 5% (5% weight loss temperature) was measured using a thermogravimetric measuring device (manufactured by Shimadzu Corporation, TGA-50) when the temperature was raised from room temperature at 10° C./min, with the weight of the film at 170° C. being taken as 100%.

(6) Chemical resistance test of cured relief pattern on Cu A 200 nm thick Ti film and a 400 nm thick Cu film were sputtered in this order on a 6-inch silicon wafer (manufactured by Fujimi Electronics Co., Ltd., thickness 625±25 μm) using a sputtering device (L-440S-FHL type, manufactured by Canon Anelva Corporation). Next, a photosensitive resin composition prepared by the method described below was spin-coated on this wafer using a coater developer (D-Spin 60A type, manufactured by SOKUDO Co., Ltd.) and dried to form a coating film with a thickness of 10 μm. This coating film was irradiated with energy of 500 mJ/cm ² using a test pattern mask with Prisma GHI (manufactured by Ultratech Co., Ltd.). The coating was then spray-developed with a coater developer (D-Spin 60A type, manufactured by Sokudo Co., Ltd.) using cyclopentanone as a developer, and rinsed with propylene glycol methyl ether acetate to obtain a relief pattern on Cu.
The wafer on which the relief pattern was formed on Cu was subjected to a heat treatment in a temperature-rising programmable curing furnace (VF-2000 type, manufactured by Koyo Lindberg Co., Ltd.) at 170° C. for 2 hours in a nitrogen atmosphere to obtain a cured relief pattern made of resin having a thickness of about 6 to 7 μm on Cu.
The prepared relief pattern was immersed for 5 minutes in a resist peeling film (manufactured by ATMI, product name ST-44, main components being 2-(2-aminoethoxy)ethanol and 1-cyclohexyl-2-pyrrolidone) heated to 50°C, washed with running water for 30 minutes, and air-dried. Thereafter, the film surface was visually observed with an optical microscope, and the chemical resistance was evaluated based on the presence or absence of damage caused by the chemical solution, such as cracks, and the rate of change in film thickness after chemical treatment. Chemical resistance was evaluated based on the following criteria.
Film thickness change rate (%)=(film thickness after chemical treatment)−(film thickness before chemical treatment)/(film thickness before chemical treatment)×100
"Excellent": The rate of change in film thickness is less than 5% based on the film thickness before immersion in the chemical solution. "Good": The rate of change in film thickness is 5% to less than 10% based on the film thickness before immersion in the chemical solution. "Fair": The rate of change in film thickness is 10% to less than 15% based on the film thickness before immersion in the chemical solution. "Unfair": The rate of change in film thickness is 15% or more based on the film thickness before immersion in the chemical solution.

(7) Resolution of cured relief pattern on Cu A 6-inch silicon wafer (manufactured by Fujimi Electronics Co., Ltd., thickness 625±25 μm) was sputtered with a 200 nm thick Ti film and a 400 nm thick Cu film in this order using a sputtering device (L-440S-FHL type, manufactured by Canon Anelva Corporation). Next, a photosensitive resin composition prepared by the method described below was spin-coated on this wafer using a coater developer (D-Spin 60A type, manufactured by SOKUDO Co., Ltd.) and dried to form a coating film with a thickness of 10 μm. This coating film was irradiated with energy of 500 mJ/cm ² using a test pattern mask with Prisma GHI (manufactured by Ultratech Co., Ltd.). The coating was then spray-developed with a coater developer (D-Spin 60A type, manufactured by Sokudo Co., Ltd.) using cyclopentanone as a developer, and rinsed with propylene glycol methyl ether acetate to obtain a relief pattern on Cu.
The wafer on which the relief pattern was formed on Cu was subjected to a heat treatment in a temperature-rising programmable curing furnace (VF-2000 type, manufactured by Koyo Lindberg Co., Ltd.) at 170° C. for 2 hours in a nitrogen atmosphere to obtain a cured relief pattern made of resin having a thickness of about 6 to 7 μm on Cu.
The relief pattern thus produced was observed under an optical microscope to determine the size of the minimum opening pattern. If the area of the opening of the obtained pattern was 1/2 or more of the area of the corresponding opening in the pattern mask, the pattern was deemed resolved, and the length of the side of the mask opening corresponding to the opening having the smallest area among the resolved openings was taken as the resolution.
"Excellent": The minimum opening pattern size is less than 10 μm. "Good": The minimum opening pattern size is 10 μm or more and less than 14 μm. "Fair": The minimum opening pattern size is 14 μm or more and less than 18 μm. "Unfair": The minimum opening pattern size is 18 μm or more.

(8) Measurement of total chlorine content of resin composition After preparing the photosensitive resin composition, the composition was left to stand for 3 days at room temperature (23.0°C ± 0.5°C, relative humidity 50% ± 10%), and then the total chlorine content (total amount of free chlorine and covalently bonded chlorine) of the resin composition was measured. The photosensitive resin composition was burned and decomposed at 800°C, the decomposition gas was absorbed in ultrapure water, and the total chlorine content in the resin composition was determined by ion chromatography. The ion chromatography was composed of Dionex IC-1000 and IonPac AS12A (4 mm) column, and the eluent was 0.3 mM NaHCO ₃ /2.7 mM Na ₂ CO ₃ aqueous solution, and the measurement was performed at a flow rate of 1.5 mL/min.

[(A) Production of polyimide precursor]
<Production Example 1> Synthesis of Polyimide Precursor A-1 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 2 L separable flask, 131.2 g of 2-hydroxyethyl methacrylate (HEMA) and 400 mL of γ-butyrolactone were added and stirred at room temperature, and 81.5 g of pyridine was added while stirring to obtain a reaction mixture. After the heat generation due to the reaction had ceased, the reaction mixture was allowed to cool to room temperature and left to stand for 16 hours.
Next, under ice cooling, a solution of 206.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 180 mL of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring, followed by the addition of a suspension of 93.0 g of 4,4'-oxydianiline (ODA) suspended in 350 mL of γ-butyrolactone over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 mL of ethyl alcohol was added and stirred for 1 hour, and then 400 mL of γ-butyrolactone was added. The precipitate formed in the reaction mixture was removed by filtration to obtain a reaction liquid.
The obtained reaction solution was added to 3 L of ethyl alcohol to produce a precipitate consisting of a crude polymer. The produced crude polymer was filtered off and dissolved in 1.5 L of tetrahydrofuran to obtain a crude polymer solution. The obtained crude polymer solution was dropped into 28 L of water to precipitate the polymer, and the resulting precipitate was filtered off and then vacuum dried to obtain a powdered polymer (Polymer A-1). The molecular weight of Polymer (A-1) was measured by gel permeation chromatography (standard polystyrene equivalent) to find that the weight average molecular weight (Mw) was 20,000.

The weight average molecular weight of the resin obtained in each production example was measured by gel permeation chromatography (GPC) under the following conditions, and the weight average molecular weight was calculated in terms of standard polystyrene.
Pump: JASCO PU-980
Detector: JASCO RI-930
Column oven: JASCO CO-965 40°C
Column: Shodex KD-806M, 2 in series Mobile phase: 0.1 mol/L LiBr/NMP
Flow rate: 1 mL/min.

Production Example 2: Synthesis of polyimide precursor A-2 Polymer (A-2) was obtained by carrying out a reaction in the same manner as in the above Production Example 1, except that 147.1 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used instead of 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) in Production Example 1. The molecular weight of polymer (A-2) was measured by gel permeation chromatography (standard polystyrene equivalent) and found to have a weight average molecular weight (Mw) of 26,000.

Production Example 3 Synthesis of Polyimide Precursor A-3 Polymer (A-3) was obtained by carrying out a reaction in the same manner as in the above Production Example 1, except that 48.7 g of p-phenylenediamine was used instead of 93.0 g of 4,4'-oxydianiline (ODA) in Production Example 1. The molecular weight of polymer (A-3) was measured by gel permeation chromatography (standard polystyrene equivalent) and found to have a weight average molecular weight (Mw) of 24,000.

Production Example 4 Synthesis of Polyimide Precursor A-4 Polymer (A-4) was obtained by carrying out a reaction in the same manner as in the above Production Example 1, except that 98.6 g of 4,4'-diamino-2,2'-dimethylbiphenyl was used instead of 93.0 g of 4,4'-oxydianiline (ODA) in Production Example 1. The molecular weight of polymer (A-4) was measured by gel permeation chromatography (standard polystyrene equivalent) and found to have a weight average molecular weight (Mw) of 26,000.

[Production of compound (B)]
<Production Example 5> Synthesis of epoxy (meth)acrylate compound B-1 34.0 g of bisphenol A diglycidyl ether was placed in a 1 L separable flask, and 0.4 g of dimethylaniline, 0.04 g of p-methoxyphenol, and 15.5 g of methacrylic acid were added and reacted at 100° C. After confirming that the reaction had progressed by measuring the acid value, the mixture was mixed with 40.5 g of ion exchange resin IRA96SB, stirred overnight, and the ion exchange resin was removed by filtration. This process was repeated three times to obtain B-1 containing {[propane-2,2-diylbis(4,1-phenylene)]bis(oxy)}bis(2-hydroxypropane-3,1-diyl)=dimethacrylate as the main component.

Production Example 6 Synthesis of epoxy (meth)acrylate compound B-2 A reaction was carried out in the same manner as in the above Production Example 5, except that 13.0 g of acrylic acid was used instead of 15.5 g of methacrylic acid, to obtain B-2 containing {[propane-2,2-diylbis(4,1-phenylene)]bis(oxy)}bis(2-hydroxypropane-3,1-diyl)diacrylate as the main component.

<Production Example 7> Synthesis of epoxy (meth)acrylate compound B-3 Except for using 17.42 g of ethylene glycol diglycidyl ether instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-3 containing 1,2-bis(3-methacryloyloxy-2-hydroxypropyloxy)ethane as a main component.

<Production Example 8> Synthesis of epoxy (meth)acrylate compound B-4 Except for using 17.42 g of ethylene glycol diglycidyl ether instead of 34.0 g of bisphenol A diglycidyl ether and using 13.0 g of acrylic acid instead of 15.5 g of methacrylic acid, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-4 containing 1,2-bis(3-acryloyloxy-2-hydroxypropoxy)ethane as a main component.

<Production Example 9> Synthesis of epoxy (meth)acrylate compound B-5 Except for using 23.23 g of glycerin diglycidyl ether instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-5 containing glycerol 1,3-diglycerolate dimethacrylate as a main component.

<Production Example 10> Synthesis of epoxy (meth)acrylate compound B-6 A reaction was carried out in the same manner as in the above-mentioned Production Example 5, except that 23.23 g of glycerin diglycidyl ether was used instead of 34.0 g of bisphenol A diglycidyl ether and 13.0 g of acrylic acid was used instead of 15.5 g of methacrylic acid, to obtain B-6 containing glycerol 1,3-diglycerolate diacrylate as a main component.

<Production Example 11> Synthesis of epoxy (meth)acrylate compound B-7 Except for using 31.24 g of bisphenol F type epoxy instead of 34.0 g of bisphenol A diglycidyl ether, the reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-7 containing bis[p-(3-methacryloxy-2-hydroxypropoxy)phenyl)]methane as a main component.

<Production Example 12> Synthesis of epoxy (meth)acrylate compound B-8 Except for using 15.02 g of glycidyl phenyl ether instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-8 containing 2-hydroxy-3-phenoxypropyl methacrylate as a main component.

<Production Example 13> Synthesis of epoxy (meth)acrylate compound B-9 A reaction was carried out in the same manner as in the above-mentioned Production Example 5, except that 15.02 g of glycidyl phenyl ether was used instead of 34.0 g of bisphenol A diglycidyl ether, and 13.0 g of acrylic acid was used instead of 15.5 g of methacrylic acid, to obtain B-9 containing 2-hydroxy-3-phenoxypropyl acrylate as a main component.

<Production Example 14> Synthesis of epoxy (meth)acrylate compound B-10 Except for using 35.3 g of bisphenol A diglycidyl ether hydrogenated product instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-10 containing 2,2-bis[4-(2-hydroxy-3-methacryloxy-1-propoxy)phenyl]propane as a main component.

Production Example 15 Synthesis of epoxy (meth)acrylate compound B-11 Except for using 46.25 g of 9,9-bis[4-(2-glycidylethoxy)phenyl]fluorene instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above Production Example 5, to obtain B-11 containing 4,4'-(9-fluorenylidene)bis(2-hydroxy-3-phenoxypropyl methacrylate) as a main component.

<Production Example 16> Synthesis of epoxy (meth)acrylate compound B-12 Except for using 24.30 g of 1,6-bis(glycidyloxy)naphthalene instead of 34.0 g of bisphenol A diglycidyl ether, a reaction was carried out in the same manner as in the above-mentioned Production Example 5, to obtain B-12 containing 1,6-bis(3-methacryloyloxy-2-hydroxypropyloxy)naphthalene as a main component.

<Production Example 17> Synthesis of epoxy (meth)acrylate compound B-13 34.0 g of bisphenol A diglycidyl ether was placed in a 1 L separable flask, and 0.4 g of dimethylaniline, 0.04 g of p-methoxyphenol, and 17.4 g of methacrylic acid were added and reacted at 100° C. The progress of the reaction was confirmed by measuring the acid value, and B-13 containing {[propane-2,2-diylbis(4,1-phenylene)]bis(oxy)}bis(2-hydroxypropane-3,1-diyl)=dimethacrylate as the main component was obtained without removing free chlorine with an ion exchange resin.

[Production of photosensitive resin composition]
Example 1
A negative photosensitive resin composition was prepared using polyimide precursor A-1 by the following method, and the prepared composition was evaluated. (A) 100 g of A-1 as a polyimide precursor, (B) 10 g of B-1 as an epoxy (meth)acrylate compound, (C) 5 g of 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)-oxime (hereinafter referred to as PDO) as a photopolymerization initiator, (F) 5 g of tetraethylene glycol dimethacrylate (hereinafter referred to as M4G) as a monomer, and (D) 100 g of γ-butyrolactone (hereinafter referred to as GBL) were dissolved. The viscosity of the obtained solution was adjusted to about 40 poise by further adding a small amount of GBL to obtain a negative photosensitive resin composition. From the above procedure, the amount of free chlorine and the amount of total chlorine in (E) the photosensitive resin composition, and the amount of free chlorine contained in the cured film were adjusted. The composition was evaluated according to the above method. The results are shown in Table 1.

<Examples 2 to 18 and Comparative Examples 1 to 4>
Negative photosensitive resin compositions were prepared in the same manner as in Example 1, except that they were prepared in the blending ratios shown in Table 1, and evaluations were carried out in the same manner as in Example 1. The results are shown in Tables 1 and 2.

As is clear from Tables 1 and 2, the photosensitive resin composition of Example 1 had a glass transition temperature of 210°C, a 5% weight loss temperature of 300°C, a resolution of "excellent," and a chemical resistance test result of "excellent." Similarly, the photosensitive resin compositions of Examples 2 to 10 all had glass transition temperatures of 195°C or higher, 5% weight loss temperatures of 290°C or higher, resolution results of "fair" or higher, and chemical resistance test results of "fair" or higher.

In contrast, in Comparative Example 1, the resolution was "excellent," but the glass transition temperature was 170°C and the 5% weight loss temperature was 260°C. As a result of the chemical resistance test, the film thickness change rate changed by 20% based on the film thickness before immersion, and the evaluation was "unacceptable." In Comparative Example 2, the glass transition temperature was 210°C, the 5% weight loss temperature was 300°C, and the resolution was "good," but the chemical resistance changed by 15%, and the evaluation was "unacceptable." In Comparative Example 3, the glass transition temperature was 200°C and the 5% weight loss temperature was 300°C, but the resolution was "unacceptable." In Comparative Example 4, the chemical resistance was "unacceptable."

The above describes an embodiment of the present invention, but the present invention is not limited to this and can be modified as appropriate without departing from the spirit of the invention.

By using the photosensitive resin composition of the present invention, it is possible to improve the glass transition temperature and 5% weight loss temperature while maintaining high resolution in a cured film processed at low temperature, and to improve chemical resistance. Therefore, the photosensitive resin composition of the present invention can be suitably used in the field of photosensitive materials that are useful for manufacturing electrical and electronic materials such as semiconductor devices and multilayer wiring boards.

Claims (16)

(A) a polyimide precursor;
(B) a compound having a hydroxyl group and a polymerizable unsaturated bond;
(C) a photosensitizer; and
(D) a solvent;
(E) free chlorine;
A photosensitive resin composition comprising:
The amount of the free chlorine is 0.0001 to 2 ppm based on the total mass of the photosensitive resin composition. The photosensitive resin composition according to claim 1, wherein the photosensitizer (C) is a photopolymerization initiator. The photosensitive resin composition according to claim 1 or 2, wherein the polyimide precursor (A) is represented by the following general formula (1):

In formula (1), _X1 is a tetravalent organic group having 6 to 40 carbon atoms, _Y1 is a divalent organic group having 6 to 40 carbon atoms, _n1 is an integer from 2 to 150, and _R1 and _R2 are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. However, at least one of _R1 and _R2 is represented by the following general formula (2):

In formula (2), R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and m ₁ represents an integer of 2 to 10. The photosensitive resin composition according to any one of claims 1 to 3, comprising 100 to 860 parts by mass of the solvent (D) per 100 parts by mass of the polyimide precursor (A). The photosensitive resin composition according to any one of claims 1 to 4, wherein the (D) solvent contains one or more compounds selected from the group consisting of N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, and 2-octanone. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond has two or more polymerizable unsaturated bonds. The photosensitive resin composition according to any one of claims 1 to 5, wherein (B) the compound having a hydroxyl group and a polymerizable unsaturated bond is a reaction product of an epoxy resin and (meth)acrylic acid. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond is represented by the following general formula (3) or (4):

In formula (3), R ₁ is a monovalent organic group having 1 to 40 carbon atoms.

In formula (4), R ₂ is a monovalent organic group having 1 to 40 carbon atoms. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond is represented by the following general formula (5) or (6):

In formula (5), R ₃ is a monovalent organic group having 1 to 40 carbon atoms.

In formula (6), R ₄ is a monovalent organic group having 1 to 40 carbon atoms. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond includes a compound represented by the following general formula (7):

In formula (7), R ₂ is a divalent organic group having 1 to 40 carbon atoms. The photosensitive resin composition according to any one of claims 1 to 5, wherein the compound (B) having a hydroxyl group and a polymerizable unsaturated bond includes a compound represented by the following general formula (8):

In formula (8), R ₆ is a divalent organic group having 1 to 40 carbon atoms. (A) a polyimide precursor;
(B) a compound having a hydroxyl group and a polymerizable unsaturated bond;
(C) a photosensitizer; and
(D) a solvent;
(E) a photosensitive resin composition comprising free chlorine,
The photosensitive resin composition is applied onto a substrate by a rotation method so that the film thickness after curing is about 10 μm, and when the composition is cured by heating on a hot plate at 110° C. for 180 seconds, the amount of free chlorine contained in the resulting coating film is 0.0001 to 5 ppm based on the total mass of the coating film. The photosensitive resin composition according to any one of claims 1 to 12, further comprising (G) an epoxy resin. The photosensitive resin composition according to claim 13, wherein the amount of the epoxy resin (G) is 0.1 to 10 parts by mass per 100 parts by mass of the polyimide precursor (A). The photosensitive resin composition according to any one of claims 1 to 14, which is a negative type photosensitive resin composition. (A) a polyimide precursor;
(B) a compound having a hydroxyl group and a plurality of polymerizable unsaturated bonds;
(C) a photosensitizer; and
(D) a solvent;
(E) free chlorine and/or covalently bound chlorine;
A photosensitive resin composition comprising:
A photosensitive resin composition, wherein after the photosensitive resin composition is prepared, the photosensitive resin composition is allowed to stand for 3 days at 23°C±0.5°C and a relative humidity of 50%±10%, and the total amount of chlorine in the photosensitive resin composition is 0.0001 to 250 ppm based on the total mass of the photosensitive resin composition.