TWI897013B - Negative photosensitive resin composition and method for producing hardened relief pattern - Google Patents

Abstract

The subject of the present invention is to provide a negative photosensitive resin composition that has higher mechanical strength and exhibits better adhesion to aluminum, and a method for producing a hardened relief pattern using the photosensitive resin composition. The negative photosensitive resin composition of the present invention comprises: (A) having the following general formula (1): A polyimide precursor having a structure of {wherein, _X1 is a tetravalent organic group, _Y1 is a divalent organic group, _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, and at least one of _R1 and _R2 is a group having an ethylenically unsaturated bond}; (B) a plasticizer having a freezing point or melting point of not less than -40°C and having three or more repeating units; and (C) a photopolymerization initiator.

Description

Negative photosensitive resin composition and method for producing hardened relief pattern

The present invention relates to a negative photosensitive resin composition and a method for producing a hardened relief pattern.

Traditionally, insulating materials for electronic components and passivation films, surface protective films, and interlayer insulation films for semiconductor devices have relied on polyimide resins, which offer excellent heat resistance, electrical properties, and mechanical properties. Among these polyimide resins, photosensitive polyimide precursors are now available. Through thermal imidization treatments such as coating, exposure, development, and curing, these precursors can easily form heat-resistant, relief-patterned films. Compared to conventional non-photosensitive polyimides, these photosensitive polyimide precursors significantly reduce the number of steps required.

Meanwhile, in recent years, the method of mounting semiconductor devices on printed circuit boards has evolved to improve integration and functionality, while reducing chip size. Previous mounting methods, which utilized metal pins and lead-tin eutectic soldering, have shifted to structures that use polyimide films in direct contact with solder bumps. These structures, such as BGAs (ball grid arrays) and CSPs (chip-scale packages), enable higher-density mounting. The formation of these bump structures requires the film to exhibit high heat and chemical resistance.

Furthermore, as semiconductor devices become increasingly miniaturized, the problem of wiring delay has become increasingly prominent. To improve the wiring resistance of semiconductor devices, the industry has adopted methods such as replacing the gold or aluminum wiring used to date with copper or copper alloy wiring, which has lower resistance, or preventing wiring delay by improving the insulation between wiring. In recent years, low-k dielectric materials, as a material with high insulation properties, have become a common component of semiconductor devices. However, low-k dielectric materials are often brittle and easily damaged. Semiconductor devices containing low-k dielectric materials have the following problems: For example, during the reflow soldering step when they are mounted on a substrate together with the semiconductor chip, shrinkage caused by temperature fluctuations can damage the low-k dielectric material. While protective film materials with high heat resistance and excellent mechanical properties have been developed to prevent this, there is a problem: the film becomes hard, which deteriorates the adhesion with aluminum used in wiring, terminals, and pads.

Patent Document 1 discloses a photosensitive resin composition that achieves high mechanical strength through the use of a specific polyimide precursor. However, there has been a recent demand for photosensitive resin compositions with even higher mechanical strength, and no mention is made of adhesion to aluminum, suggesting that further improvement is needed. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2021-173787

[Identify the problem you want to solve]

Therefore, an object of the present invention is to provide a negative photosensitive resin composition that exhibits higher mechanical strength and better adhesion to aluminum, and a method for producing a hardened relief pattern using the photosensitive resin composition. [Technical Solution]

[Item 1] A negative photosensitive resin composition comprising: (A) a photosensitive resin having the following general formula (1): A polyimide precursor having a structure of {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, 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, and at least one of R ₁ and R ₂ is a group having an ethylenically unsaturated bond}; (B) a plasticizer having a freezing point or melting point of -40°C or higher and having three or more repeating units; and (C) a photopolymerization initiator. [Item 2] A negative photosensitive resin composition comprising: (A) a compound having the following general formula (1): [Chemical 2] A polyimide precursor having a structure of {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, 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, and at least one of R ₁ and R ₂ is a group having an ethylenically unsaturated bond}; (B) the following general formula (3): [Chemical 3] (wherein _n2 is an integer from 6 to 45, a and b are each independently an integer from 0 to 5; provided that the sum of a and b is an integer from 1 to 5; and _R6 , _R7 , R6 _' , R7 _' , _R8 , and _R9 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) a plasticizer; and (C) a photopolymerization initiator. [Item 3] A negative photosensitive resin composition as described in item 1 or 2, wherein _R1 and _R2 in the above general formula (1) are each independently a hydrogen atom, or the following general formula (2): [Chemistry 4] (wherein R ₃ , R ₄ , and R ₅ are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and m ₁ is an integer from 2 to 10) a monovalent organic group represented by, or a saturated aliphatic group having 1 to 4 carbon atoms. [Item 4] A negative photosensitive resin composition as described in any one of Items 1 to 3, wherein Y ₁ in the above general formula (1) comprises a structure represented by the following general formula (4). [Chemistry 5] (In the formula, R ₁₀ and R ₁₁ each independently represent an alkyl group having 1 to 4 carbon atoms, a fluorine atom, or a trifluoromethyl group) [Item 5] A negative photosensitive resin composition as described in any one of Items 1 to 4, wherein X ₁ in the general formula (1) comprises at least one structure selected from the group consisting of the following general formulas (5), (6), and (7). [Chemistry 6] [Chemistry 7] [Chemistry 8] [Item 6] The negative photosensitive resin composition according to any one of Items 1 to 5, comprising the plasticizer (B) having a structure represented by _n2 in the general formula (3) being an integer of 8 to 23. [Item 7] The negative photosensitive resin composition according to any one of Items 1 to 6, comprising 5 to 30 parts by mass of the plasticizer (B) per 100 parts by mass of the polyimide precursor (A). [Item 8] The negative photosensitive resin composition according to any one of Items 1 to 7, comprising a radically polymerizable compound (E). [Item 9] A negative photosensitive resin composition as described in any one of Items 1 to 8, which is a negative photosensitive resin composition for forming a surface protective film, an interlayer insulating film, a protective film for redistribution wiring, a protective film for a flip chip device, or a protective film for a semiconductor device having a bump structure. [Item 10] A method for producing a hardened relief pattern, comprising: (1) forming a photosensitive resin layer on a substrate by applying a negative photosensitive resin composition as described in any one of Items 1 to 9 onto the substrate; (2) exposing the photosensitive resin layer to light; (3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) hardening the relief pattern by heating the relief pattern. [Effects of the Invention]

According to the present invention, a negative photosensitive resin composition exhibiting high mechanical strength and adhesion to aluminum and capable of obtaining good resolution, a hardened relief pattern using the photosensitive resin composition, and a method for producing the same can be provided.

The following describes in detail a method for implementing the present invention (hereinafter referred to as the "present embodiment"). The present invention is not limited to the present embodiment and can be implemented with various modifications within the scope of its spirit. Unless otherwise specified, the characteristic values described in this embodiment are values measured using the methods described in the "Examples" section or methods recognized by the industry as equivalent.

In the following description, the upper or lower limit of a numerical range described in a segmented manner may be replaced with the upper or lower limit of another numerical range described in a segmented manner. Furthermore, the upper or lower limit of a numerical range described in a particular segmented manner may be replaced with the value described in the embodiments. Furthermore, the term "step" in the following description clearly encompasses independent steps. Even if a step cannot be clearly distinguished from other steps, as long as the function of the step is achieved, it is included in this term.

<Negative photosensitive resin composition> The negative photosensitive resin composition of this embodiment (hereinafter referred to as the photosensitive resin composition of this embodiment) comprises: (A) having the following general formula (1): [Chemical 9] A polyimide precursor having a structure of {wherein, _X1 is a tetravalent organic group, _Y1 is a divalent organic group, _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, and at least one of _R1 and _R2 is a group having an ethylenically unsaturated bond}; (B) a plasticizer having a freezing point or melting point of not less than -40°C and having three or more repeating units, or the following general formula (3): [Chemical 10] (wherein n ₂ is an integer from 6 to 45, a and b are each independently an integer from 0 to 5; the total of a and b is an integer from 1 to 5; and R ₆ , R ₇ , R _6' , R _7' , R ₈ , and R ₉ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); and (C) a photopolymerization initiator.

<(A) Polyimide Precursor> The (A) polyimide precursor used in this embodiment will be described. The resin component in the photosensitive resin composition of this embodiment is a polyimide having a structural unit represented by the following general formula (1). The (A) polyimide precursor is converted into polyimide by applying a thermal cyclization treatment. [Chemical 11] {wherein, _X1 is a tetravalent organic group, _Y1 is a divalent organic group, _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, and at least one of _R1 and _R2 is a group having an ethylenically unsaturated bond}

Furthermore, if _R1 and _R2 in the general formula (1) are independently hydrogen atoms, or the general formula (2): [Chemical 12] (wherein R ₃ , R ₄ , and R ₅ are independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and m ₁ is an integer from 2 to 10) or a saturated aliphatic group having 1 to 4 carbon atoms is more preferred from the viewpoint of resolution and compatibility. The group having an ethylenically unsaturated bond is preferably a monovalent organic group represented by the above general formula (2).

The ratio of hydrogen atoms in R ₁ and R ₂ in the general formula (1) is preferably 10% or less, more preferably 5% or less, and further preferably 1% or less, based on the total molar number of R _{1 and} R 2. Furthermore, the ratio of monovalent organic groups represented by the general formula (2) in R ₁ and R ₂ in the general formula (1) is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more, based on the total molar number of R ₁ and R _2. When the ratio of hydrogen atoms and the ratio of organic groups having the structure represented by the general formula (2) are within the above ranges, it is preferred from the viewpoint of photosensitivity and storage stability.

_n1 in the general formula (1) is not particularly limited and can be an integer of 2 to 150. From the viewpoint of the photosensitivity and mechanical properties of the negative photosensitive resin composition, it is preferably an integer of 3 to 100, and more preferably an integer of 5 to 70.

In general formula (1), from the perspective of achieving both heat resistance and photosensitivity, the tetravalent organic group represented by _X1 is preferably an organic group having 6 to 40 carbon atoms, and more preferably an aromatic group or an alicyclic aliphatic group in which _-COOR1 and _-COOR2 are adjacent to the -CONH- group. Specifically, the tetravalent organic group represented by _X1 includes an organic group having 6 to 40 carbon atoms and containing an aromatic ring. For example, the following general formula (9) can be exemplified: [Chemical 13] The present invention also includes a group having a structure represented by {wherein, R ₁₆ is at least one selected from the group consisting of a hydrogen atom, a fluorine atom, a C1-C10 monovalent alkyl group, and a C1-C10 monovalent fluorinated alkyl 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}, but is not limited thereto. Furthermore, X ₁ may be selected from only one group having the above-mentioned structure, or from a combination of two or more groups. The X ₁ group having the structure represented by formula (9) is particularly preferred from the viewpoint of achieving both heat resistance and photosensitivity.

If the negative photosensitive resin composition of this embodiment comprises a structure represented by formula (9), in particular, one selected from the following general formulas (5), (6), and (7): [Chemistry 15] [Chemistry 16] At least one structure in the group is preferably used as the _X1 group from the viewpoints of the imidization rate during low-temperature heating, degassing properties, adhesion, mechanical strength, and chemical resistance.

Furthermore, in the general formula (1), from the viewpoint of achieving both heat resistance and photosensitivity, the divalent organic group represented by _Y1 is preferably an aromatic group having 6 to 40 carbon atoms, for example, the following formula (10): The structure represented by {wherein, R ₁₇ is at least one selected from the group consisting of a hydrogen atom, a fluorine atom, a C1-C10 monovalent alkyl group, and a C1-C10 monovalent fluorinated alkyl group, and n is an integer selected from 0 to 4} is not limited thereto. Furthermore, Y ₁ may be selected from only one group having the above-mentioned structure, or from a combination of two or more groups. A Y ₁ group having the structure represented by formula (10) is particularly preferred from the viewpoint of achieving both heat resistance and photosensitivity.

If the negative photosensitive resin composition of this embodiment comprises the structure represented by formula (10), in particular, the following general formula (4): [Chemical 18] (wherein R ₁₀ and R ₁₁ independently represent an alkyl group having 1 to 4 carbon atoms, a fluorine atom, or a trifluoromethyl group) is preferably used as the Y ₁ group from the viewpoints of mechanical strength, chemical resistance, and adhesion.

In one embodiment, the polyimide precursor (A) preferably has the general formula (11): A polyimide precursor comprising structural units represented by {wherein R ₁ , R ₂ , and n ₁ have the same meanings as above}. More preferably, in general formula (11), at least one of R ₁ and R ₂ is a monovalent organic group represented by general formula (2). When the polyimide precursor (A) comprises a polyimide precursor represented by general formula (11), chemical resistance is particularly enhanced.

In one embodiment, from the viewpoint of thermal properties, the polyimide precursor (A) preferably has the general formula (12): A polyimide precursor comprising a structural unit represented by {wherein R ₁ , R ₂ , and n ₁ have the same meanings as above}. More preferably, in general formula (12), at least one of R ₁ and R ₂ is a monovalent organic group represented by general formula (2).

In one embodiment, from the viewpoint of thermal properties, the polyimide precursor (A) preferably has the general formula (13): A polyimide precursor comprising a structural unit represented by {wherein R ₁ , R ₂ , and n ₁ have the same meanings as above}. More preferably, in general formula (13), at least one of R ₁ and R ₂ is a monovalent organic group represented by general formula (2).

In one embodiment, from the viewpoint of mechanical strength, the polyimide precursor (A) preferably has the general formula (14): {wherein, R ₁ , R ₂ , and n ₁ have the same meanings as above}. More preferably, in general formula (14), at least one of R ₁ and R ₂ is a monovalent organic group represented by general formula (2).

In one embodiment, from the viewpoint of mechanical strength, the polyimide precursor (A) preferably has the general formula (15): {wherein, R ₁ , R ₂ , and n ₁ have the same meanings as above}. More preferably, in general formula (15), at least one of R ₁ and R ₂ is a monovalent organic group represented by general formula (2).

From the perspective of resolution and mechanical strength, the polyimide precursor (A) preferably contains one or more different structural units represented by the general formula (1). Furthermore, the polyimide precursor (A) may contain a mixture of polyimide precursors that are represented by the general formula (1) but have different structures. Here, different structural units represented by the same chemical formula refer to structural units having the same structure represented by the general formula (1) but having different structures due to different groups in the formula, or having different content ratios of the structural units. If the polyimide precursor (A) contains both the structural unit represented by the general formula (14) and the structural unit represented by the general formula (15), it is particularly preferable from the viewpoint of resolution and mechanical strength. For example, the polyimide precursor (A) may contain a copolymer of the structural unit represented by the general formula (14) and the structural unit represented by the general formula (15), or may contain a mixture of the polyimide precursor represented by the general formula (14) and the polyimide precursor represented by the general formula (15).

(A) Preparation Method of Polyimide Precursor Regarding the (A) polyimide precursor, first, a tetracarboxylic dianhydride containing the aforementioned tetravalent organic group _X1 is reacted with an alcohol having a photopolymerizable unsaturated double bond and an optional alcohol not having an unsaturated double bond to prepare a partially esterified tetracarboxylic acid (hereinafter also referred to as an acid/ester). Subsequently, the partially esterified tetracarboxylic acid is subjected to amide condensation with a diamine containing the aforementioned divalent organic group _Y1 to obtain the (A) polyimide precursor.

(Preparation of Acid/Ester) In this embodiment, the tetravalent organic group X is suitable for preparing (A) the polyimide precursor. Examples of the tetracarboxylic dianhydride of ₁ include the tetracarboxylic dianhydride represented by the above-mentioned general formula (9), such as 4,4'-oxydiphthalic dianhydride (ODPA), pyromellitic dianhydride (PMDA), diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA), diphenylsulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane. Preferred examples include, but are not limited to, 4,4'-oxydiphthalic dianhydride (ODPA), pyromellitic dianhydride (PMDA), diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, and biphenyl-3,3',4,4'-tetracarboxylic dianhydride (BPDA). Furthermore, these may be used alone or in combination of two or more.

In the present embodiment, the photopolymerizable unsaturated double bond alcohols suitable for preparing the polyimide precursor (A) include, for example, 2-acryloyloxyethanol, 1-acryloyloxy-3-propanol, 2-acrylamidoethanol, hydroxymethyl vinyl ketone, 2-hydroxyethyl vinyl ketone, 2-hydroxyethyl methacrylate (HEMA), 2-hydroxy-3-methoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-meth ...tert-butyl acrylate, 2-hydroxy-3-methoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-tert-butyl acrylate, 2-hydroxy-3-tert-butyl methacrylate, 2-hydroxy-3-methoxypropyl methacrylate, 2-hydroxy-3-cyclohexyloxypropyl methacrylate, 2-methacryloyloxyethanol, 1-methacryloyloxy-3-propanol, 2-methacrylamidoethanol, hydroxymethyl vinyl ketone, 2-hydroxyethyl vinyl ketone, 2-hydroxy-3-methoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-tert-butoxypropyl methacrylate, 2-hydroxy-3-cyclohexyloxypropyl methacrylate, etc.

The above-mentioned alcohols having photopolymerizable unsaturated double bonds may be mixed with a portion of alcohols not having unsaturated double bonds, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, 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, benzyl alcohol, etc.

Alternatively, a non-photosensitive polyimide precursor prepared solely from the aforementioned alcohols lacking unsaturated double bonds can be mixed with a photosensitive polyimide precursor to form the polyimide precursor. From the perspective of resolution, the non-photosensitive polyimide precursor is preferably present in an amount of 200 parts by weight or less based on 100 parts by weight of the photosensitive polyimide precursor.

The above-mentioned suitable tetracarboxylic dianhydride and the above-mentioned alcohol can be mixed in the presence of an alkaline catalyst such as pyridine, dissolved in a solvent as described below at a temperature of 20-50°C, and stirred for 4-24 hours to carry out an esterification reaction of the anhydride to obtain the desired acid/ester.

(Preparation of Polyimide Precursor) A suitable dehydrating condensing agent, such as dicyclohexylcarbodiimide (DCC), 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1,1-carbonyldioxy-di-1,2,3-benzotriazole, or N,N'-disuccinimide carbonate, can be added to the above-mentioned acid/ester compound (typically a solution of the acid/ester compound in the solvent described below) under ice cooling and mixed to convert the acid/ester compound into a polyanhydride. Subsequently, a diamine containing a divalent organic group _Y1 suitable for use in this embodiment, separately dissolved or dispersed in a solvent, is added dropwise to the mixture to carry out amide condensation, thereby obtaining the target polyimide precursor. Alternatively, the target polyimide precursor can be obtained by partially acylating the acid/ester using sulfinyl chloride or the like, and then reacting the resulting mixture with a diamine compound in the presence of a base such as pyridine.

Examples of diamines containing a divalent organic group _Y1 suitable for use in the present embodiment include diamines containing _Y1 having a structure represented by the above general formula (10), such as p-phenylenediamine (pPD), 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'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminodiphenylsulfone, Aminobenzophenone, 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]sulfonium, bis[4-(3-aminophenoxy)phenyl]sulfonium, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-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, o-toluidine sulfonate, 9,9-bis(4-aminophenyl)fluorene, and some of the hydrogen atoms on the benzene ring of these compounds are substituted by methyl, ethyl, or hydroxymethyl groups. , hydroxyethyl, halogen, etc., for example, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB), 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl (mTB: m-tolidine), 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, and mixtures thereof, but not limited thereto. Preferred examples include p-phenylenediamine (pPD), 2,2'-dimethyl-4,4'-diaminobiphenyl (mTB: m-tolidine), and 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB).

After the amide polycondensation reaction is completed, the hygroscopic byproducts of the dehydrated condensation agent present in the reaction solution are filtered and separated as needed. A poor solvent, such as water, aliphatic lower alcohols, or a mixture thereof, is then added to the resulting polymer components to precipitate them. Repeated redissolution and reprecipitation operations are then performed to purify the polymer. The purified polymer is vacuum dried to isolate the target polyimide precursor. To further improve the degree of purification, the polymer solution can be passed through a column packed with an anion- and/or cation-exchange resin swollen with a suitable organic solvent to remove ionic impurities.

When measured by polystyrene-equivalent weight average molecular weight obtained by gel permeation chromatography, the molecular weight of the polyimide precursor (A) is preferably 8,000 to 150,000, more preferably 9,000 to 50,000. When the weight average molecular weight of the polyimide precursor (A) is 8,000 or greater, good mechanical properties are achieved. When the weight average molecular weight of the polyimide precursor (A) is 150,000 or less, good dispersibility in the developer is achieved, resulting in good relief pattern resolution. Preferred developing solvents for gel permeation chromatography are tetrahydrofuran and N-methyl-2-pyrrolidone. The weight average molecular weight of the polyimide precursor (A) is determined from a calibration curve prepared using standard monodisperse polystyrene. The standard monodisperse polystyrene is preferably, but not limited to, the organic solvent standard sample STANDARD SM-105 manufactured by Showa Denko K.K.

<(B) Plasticizer> The (B) plasticizer used in this embodiment is a compound having a freezing point or melting point of -40°C or higher and having three or more repeating units, and/or a compound represented by the following general formula (3). [Chemical 24] (wherein _n2 is an integer from 6 to 45, a and b are each independently an integer from 0 to 5; the sum of a and b is an integer from 1 to 5; and _R6 , _R7 , R6 _' , R7 _' , _R8 , and _R9 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)

By adding the plasticizer (B), the hardened relief pattern formed using the photosensitive resin composition of this embodiment improves adhesion to aluminum, as well as Young's modulus and resolution. While the exact reason for this is unclear, the inventors speculate that the exposed film formed using the photosensitive resin composition of this embodiment becomes softer due to the plasticizer (B), improving its ability to follow the substrate and thereby achieving good adhesion to the aluminum. Furthermore, the inventors believe that when the relief pattern formed using the photosensitive resin composition of the present embodiment is heat-cured, the plasticizer (B) can improve the fluidity of the polyimide formed after the heat cyclization of the polyimide precursor (A) through its plasticizing effect. In turn, the volatilization of the plasticizer (B) during heating can improve the filling capacity of the polymer, thereby increasing the Young's modulus. Furthermore, the inventors of the present invention have discovered that, because the polymer (A) of the polyimide precursor in which _Y1 in the general formula (1) comprises a structure represented by the general formula (4) has a high Young's modulus and strong absorption of i-rays, when a photosensitive resin composition using such a polymer is exposed to i-rays, insufficient light reaches the bottom portion, resulting in insufficient curing, which often results in planer marks at the bottom portion of the formed relief pattern. By adding a plasticizer (B) to the composition, the transparency of the photosensitive resin composition is improved while maintaining other properties, and the bottom portion is also sufficiently cured, thereby improving resolution. Furthermore, the inventors of the present invention have determined that in order to achieve these properties, the plasticizer (B) must also have good compatibility with the other composition components. Even with commonly used plasticizers, if they are not the plasticizer (B) specified in this embodiment, the intended effects cannot be fully achieved. The following describes the method for producing a hardened relief pattern according to this embodiment. To ensure that the plasticizer (B) can achieve its various properties, it is advantageous for the plasticizer (B) to remain after the photosensitive resin composition is applied to the substrate and then dried, without evaporating. Therefore, the freezing point or melting point of the plasticizer (B) is preferably above -40°C. Furthermore, the inventors of the present invention and others believe that in order to suppress the volatility caused by drying after the photosensitive resin composition of this embodiment is applied to the substrate while the plasticizer (B) maintains compatibility and plasticizing properties, such effects can be advantageously obtained by having the plasticizer (B) have more than three repeating units. The above-mentioned plasticizer (B) preferably has more than three continuous repeating units of the same structure. Furthermore, taking into account volatility, compatibility, and plasticizing properties, the plasticizer (B) can also be represented by the general formula (3), for example. The above-mentioned freezing point and melting point can be measured using known techniques. In one embodiment, the freezing point and melting point are, for example, values measured using a differential scanning calorimeter (DSC). The melting point measures the temperature at which a solid melts and becomes a liquid, while the freezing point measures the temperature at which a liquid solidifies. From the perspective of non-volatility and plasticizing properties, the freezing point or melting point of the plasticizer (B) is preferably from -40°C to 60°C, more preferably from -30°C to 50°C. Furthermore, the lower limit of the freezing point or melting point of the plasticizer (B) is preferably from -40°C to -30°C, from -10°C to 0°C, from 5°C to 50°C, or from 10°C to 10°C. Furthermore, the upper limit of the freezing point or melting point of the plasticizer (B) is preferably from 60°C to 60°C, from 50°C to 40°C. Furthermore, the repeating units of the plasticizer (B) include, for example, alkylene oxides such as ethylene oxide, propyl oxide, butyl oxide, and pentyl oxide, or the structural unit represented by the following formula obtained by ring-opening ε-caprolactone, but are not limited thereto. From the perspective of compatibility, aliphatic groups are preferred, and alkylene oxides are more preferred. [Chemical 25]

To improve aluminum adhesion, Young's modulus, plasticity, and compatibility, the number of repetitions of the repeating structure units is preferably 3 or more and 45 or less, more preferably 4 or more and 45 or less, even more preferably 6 or more and 45 or less, and most preferably 8 or more and 23 or less. Furthermore, the lower limit of the number of repetitions of the repeating structure units is preferably 3 or more, 4 or more, 6 or more, or 8 or more. Furthermore, the upper limit of the number of repetitions of the repeating structure units is preferably 45 or less, 30 or less, 23 or less, or 22 or less.

Specific examples of (B) plasticizers include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polycaprolactone glycol, or those modified at one end with an alkyl group having 1 to 6 carbon atoms, such as polyoxyethylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxyethylene monopropyl ether, polyoxyethylene monobutyl ether, polyoxyethylene monopentyl ether, polyoxyethylene monohexyl ether, polyoxypropylene monomethyl ether, polyoxypropylene monoethyl ether, polyoxypropylene monopropyl ether, polyoxypropylene monobutyl ether, polyoxypropylene monopentyl ether, polyoxypropylene monohexyl ether, polyoxytetramethylene monomethyl ether, polyoxytetramethylene monopropyl ether, polyoxytetramethylene monobutyl ether, polyoxytetramethylene monopentyl ether, polyoxytetramethylene monohexyl ether, etc. Further, examples include polyoxyethylene dimethyl ether, polyoxyethylene diethyl ether, polyoxyethylene dipropyl ether, polyoxyethylene dibutyl ether, polyoxyethylene dipentyl ether, polyoxyethylene dihexyl ether, polyoxypropylene dimethyl ether, polyoxypropylene diethyl ether, polyoxypropylene dipropyl ether, polyoxypropylene dibutyl ether, polyoxypropylene dipentyl ether, polyoxypropylene dihexyl ether, polyoxytetramethylene dimethyl ether, polyoxytetramethylene dipropyl ether, polyoxytetramethylene dibutyl ether, polyoxytetramethylene dipentyl ether, and polyoxytetramethylene dihexyl ether, which are modified at both ends with an alkyl group having 1 to 6 carbon atoms.

Among the plasticizers (B), from the viewpoint of compatibility in the photosensitive resin composition of this embodiment, adhesion between the cured film and aluminum, and Young's modulus, preferably, _n2 in the general formula (3) is an integer of 8 to 23.

From the perspective of compatibility or resolution in the photosensitive resin composition of this embodiment, the sum of a and b is preferably an integer of 2 to 3. From the perspective of resolution or cured film reliability of the photosensitive resin composition of this embodiment, _R8 and/or _R9 are preferably alkyl groups having 1 to 6 carbon atoms. Furthermore, from the perspective of compatibility in the photosensitive resin composition of this embodiment, _R6 , _R7 , R6 _' , and R7 _' are preferably hydrogen atoms or methyl groups.

(B) Commercially available plasticizers include, for example, PEG #300, PEG #400, PEG #600, PEG #1000, Uniox M-400, Uniox M-550, Uniox M-1000, Uniox M-2000, Uniox MM-400, Uniol D-400G, Uniol D-700, Uniol D-1000, and Uniol D-1200 manufactured by NOF Corporation. Also, PTMG 650, PTMG 850, PTMG 1000, PTMG 1300, and PTMG 1500 manufactured by Mitsubishi Chemical Co., Ltd. Further examples include Placcel 208, Placcel 210, Placcel 212, and Placcel 210N manufactured by Daicel Corporation.

The content of the plasticizer (B) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, based on 100 parts by mass of the polyimide precursor (A), from the viewpoint of improving adhesion to aluminum and Young's modulus. From the viewpoint of improving compatibility and resolution in the photosensitive resin composition, the content is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

<(C) Photopolymerization Initiator> The (C) photopolymerization initiator used in this embodiment is described below. The photopolymerization initiator is preferably a photo-free radical polymerization initiator, preferably exemplified by: benzophenone, methyl o-benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, benzophenone derivatives such as fluorenone, acetophenone derivatives such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, 9-oxosulfonium, , 2-methyl 9-oxosulfuronium , 2-isopropyl 9-oxosulfonium , diethyl 9-oxosulfonium 9-Oxosulfuronium derivatives, benzoyl, benzoyl dimethyl ketal, benzoyl-β-methoxyethyl acetal and other benzoyl derivatives, benzoin, benzoin methyl ether and other benzoin derivatives, 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2 Oxime such as 1,3-diphenylpropane-2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropane-2-(o-benzoyl)oxime, N-arylglycine such as N-phenylglycine, peroxides such as benzoyl perchloride, aromatic biimidazoles, titanium cyclopentadiene, and photoacid generators such as α-(n-octylsulfonyloxyimino)-4-methoxyphenylacetonitrile, but are not limited thereto. Among the above-mentioned photopolymerization initiators, oximes are particularly preferred in terms of photosensitivity.

The content of the photopolymerization initiator (C) is preferably 0.1 to 20 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 1 to 5 parts by mass, based on 100 parts by mass of the polyimide precursor (A). From the perspective of photosensitivity or resolution, the above content is preferably 0.1 parts by mass or greater, and from the perspective of the physical properties of the cured film of the photosensitive resin composition, it is preferably 20 parts by mass or less.

<(D) Solvent> The negative photosensitive resin composition of this embodiment may also contain a (D) solvent. Examples of the solvent include amides, sulfoxides, ureas, ketones, esters, lactones, ethers, hydrocarbon halides, hydrocarbons, and alcohols. Examples of solvents include N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide (DMSO), tetramethylurea, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, and ethyl lactate. , methyl lactate, butyl lactate, γ-butyrolactone (GBL), 1,3-dimethyl-2-imidazolidinone (DMI), propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, benzyl alcohol, phenylene glycol, tetrahydrofuran methanol, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, morpholine, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, chlorobenzene, o-dichlorobenzene, anisole, hexane, heptane, benzene, toluene, xylene, mesitylene, etc. Among them, from the perspectives of solubility and stability of the photosensitive resin composition, as well as adhesion to the substrate, preferred are NMP, DMSO, tetramethylurea, butyl acetate, ethyl lactate, GBL, DMI, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethylene glycol dimethyl ether, benzyl alcohol, phenylene glycol, 3-methoxy-N,N-dimethylpropionamide, 3-butoxy-N,N-dimethylpropionamide, and tetrahydrofuranol. Among these solvents, those that completely dissolve the polyimide precursor are particularly preferred. Examples include NMP, N,N-dimethylacetamide, N,N-dimethylformamide, DMSO, tetramethylurea, GBL, DMI, 3-methoxy-N,N-dimethylpropionamide, and 3-butoxy-N,N-dimethylpropionamide. In particular, GBL, DMI, and 3-methoxy-N,N-dimethylpropionamide are preferred from the perspective of achieving in-plane uniformity when the photosensitive resin composition is applied to a substrate. (D) Solvents may be used singly or as a mixture of two or more. From the perspective of appropriately adjusting the stability of the photosensitive resin composition, a mixture of two or more solvents is preferred. When two or more solvents are used, from the perspective of in-plane uniformity, 50% by weight or more of the solvent is preferably GBL or 3-methoxy-N,N-dimethylpropionamide, with GBL being more preferred.

In the photosensitive resin composition of this embodiment, the content of the solvent (D) is preferably 100 to 1000 parts by mass, more preferably 120 to 700 parts by mass, and even more preferably 125 to 500 parts by mass, relative to 100 parts by mass of the polyimide precursor (A).

<(E) Radically Polymerizable Compound> The negative photosensitive resin composition of this embodiment may also contain a (E) radically polymerizable compound. The inclusion of the (E) radically polymerizable compound can improve resolution. To achieve good resolution, the (E) radically polymerizable compound is preferably included in an amount of 3 to 40 parts by mass, more preferably 5 to 30 parts by mass, and even more preferably 10 to 20 parts by mass, per 100 parts by mass of the (A) polyimide precursor.

The radical polymerizable compound (E) in this embodiment is not particularly limited as long as it is a compound that undergoes radical polymerization reaction with a photopolymerization initiator. It is preferably a (meth)acrylic acid compound, for example, preferably the following general formula (16): A compound represented by {wherein, X ₁₁ is an organic group, L ₁₁ , L ₁₂ and L ₁₃ are each independently a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms; and n ₁₁ is an integer of 1 to 10}.

(E) Examples of free radical polymerizable compounds include diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, mono- or diacrylate and methacrylate of ethylene glycol or polyethylene glycol; mono- or diacrylate and methacrylate of propylene glycol or polypropylene glycol; mono-, di- or triacrylate and methacrylate of glycerol; cyclohexane diacrylate and dimethacrylate; diacrylate and dimethacrylate of 1,4-butanediol; diacrylate and dimethacrylate of 1,6-hexanediol; diacrylate and dimethacrylate of neopentyl glycol; mono- or diacrylate of bisphenol A; Compounds such as diacrylates and mono- or dimethacrylates of bisphenol A, benzyltrimethacrylate, isothiocyanate and isothiocyanate methacrylate, acrylamide and its derivatives, methacrylamide and its derivatives, trihydroxymethylpropane triacrylate and methacrylate, glycerol di- or triacrylate and methacrylate, pentaerythritol di-, tri-, or tetraacrylate and methacrylate, tricyclodecane dimethanol diacrylate, tris-(2-acryloyloxyethyl) isocyanurate, and ethylene oxide or propylene oxide adducts of these compounds are also included, but are not particularly limited to these examples.

More specifically, as an example of the radical polymerizable compound (E), the following formula (17) can be cited: (wherein m is an integer greater than or equal to 1, and n is an integer greater than or equal to 1; wherein the total of m and n is 30) is a compound represented by, but is not limited to, the above.

In the present invention, when the number of radical polymerizable groups in the radical polymerizable compound (E) is one, it is considered monofunctional. When it contains two or more radical polymerizable groups, it is referred to as x-functional, depending on the number x of radical polymerizable groups. However, radical polymerizable groups having two or more functional groups are sometimes collectively referred to as polyfunctional. The radical polymerizable compound (E) may be monofunctional or difunctional or higher. From the perspective of resolution and mechanical strength of the cured film, radical polymerizable compounds having difunctional or higher functional groups are preferably difunctional or higher. Furthermore, the radical polymerizable compound (E) may be used alone or as a mixture of two or more.

The weight average molecular weight of the (E) radical polymerizable compound is preferably 100 or more, more preferably 200 or more, and even more preferably 300 or more. The upper limit is preferably 2000 or less, and even more preferably 1000 or less. By setting the weight average molecular weight within the above range, the resolution is improved.

<(F) Other Additives> ・Silane Coupling Agent The negative photosensitive resin composition of this embodiment may also contain a silane coupling agent to improve the adhesion between the film formed using the negative photosensitive resin composition and the substrate. The silane coupling agent is not particularly limited, and examples thereof include: γ-glycidoxypropylmethyldimethoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinylpropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalamide, benzophenone-3,3'-bis(N-[3-triethoxysilyl)propyl]phthalamide, 1,4-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, phenyl-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propylsuccinic anhydride, N-phenylaminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-(trialkoxysilyl)propylsuccinic anhydride, γ-butylpropylmethyldimethoxysilane, 3-butylpropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) KBM803, Chisso Co., Ltd.: trade name Sila-Ace S810), 3-Benzylpropyltriethoxysilane (Azmax Co., Ltd.: trade name SIM6475.0), 3-Benzylpropylmethyldimethoxysilane (Shin-Etsu Chemical Co., Ltd.: trade name LS1375, Azmax Co., Ltd.: trade name SIM6474.0), Benzylmethyltrimethoxysilane (Azmax Co., Ltd.: trade name SIM6473.5C), Benzylmethylmethyldimethoxysilane (Azmax Co., Ltd.: trade name SIM6473.0), 3-Alkylpropyldiethoxymethoxysilane, 3-Alkylpropylethoxydimethoxysilane, 3-Alkylpropyltripropoxysilane, 3-Alkylpropyldiethoxypropoxysilane, 3-Alkylpropylethoxydipropoxysilane, 3-Alkylpropyldimethoxypropoxysilane, 3-Alkylpropylmethoxydipropoxysilane, 2-Alkylethyltrimethoxysilane, 2-Alkylethyldiethoxymethoxysilane, 2-Alkylethyl Oxydimethoxysilane, 2-Alkylethyltripropoxysilane, 2-Alkylethyltripropoxysilane, 2-Alkylethylethoxydipropoxysilane, 2-Alkylethyldimethoxypropoxysilane, 2-Alkylethylmethoxydipropoxysilane, 4-Alkylbutyltrimethoxysilane, 4-Alkylbutyltriethoxysilane, 4-Alkylbutyltripropoxysilane, N-(3-triethoxysilylpropyl)urea (Shin-Etsu Chemical Co., Ltd.: trade name LS3610, Azmax Co., Ltd.: trade name SIU9055.0), N-(3-trimethoxysilylpropyl)urea (Azmax Co., Ltd.: trade name SIU9058.0), N-(3-diethoxymethoxysilylpropyl)urea, N-(3-ethoxydimethoxysilylpropyl)urea, N-(3-tripropoxysilylpropyl)urea, N-(3-diethoxypropoxysilylpropyl)urea, N-(3-ethoxydipropoxysilylpropyl)urea, N-(3-dimethoxypropoxysilylpropyl)urea, N-(3-methoxydipropoxysilylpropyl)urea, N-(3-trimethoxysilylethyl)urea, N-(3-ethoxydimethoxysilylethyl)urea Urea, N-(3-tripropoxysilylethyl)urea, N-(3-tripropoxysilylethyl)urea, N-(3-ethoxydipropoxysilylethyl)urea, N-(3-dimethoxypropoxysilylethyl)urea, N-(3-methoxydipropoxysilylethyl)urea, N-(3-trimethoxysilylbutyl)urea, N-(3-triethoxysilylbutyl)urea, N-(3-tripropoxysilylbutyl)urea, 3-(m-aminophenoxy)propyltrimethoxysilane (manufactured by Azmax Co., Ltd.: Trade name) SLA0598.0), γ-aminopropyl dimethoxysilane, N-(β-aminoethyl)-γ-aminopropyl methyl dimethoxysilane, m-aminophenyl trimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.0), p-aminophenyl trimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.1), aminophenyl trimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.2), etc.

Examples of the silane coupling agent include 2-(trimethoxysilylethyl)pyridine (manufactured by Azmax Co., Ltd.: trade name SIT8396.0), 2-(triethoxysilylethyl)pyridine, 2-(dimethoxysilylmethylethyl)pyridine, 2-(diethoxysilylmethylethyl)pyridine, (3-triethoxysilylpropyl)-tert-butylcarbamate, (3-glycidoxypropoxypropyl)triethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-isopropoxysilane, tetra-n-butoxysilane, tetra-isobutoxysilane, tetra-tert-butoxysilane, tetra(methoxyethoxysilane), tetra(methoxy Bis(triethoxysilyl)ethane, bis(trimethoxysilyl)hexane, bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, bis(triethoxysilyl)ethylene, bis(triethoxysilyl)octane, bis(triethoxysilyl)octadiene, bis[3-(triethoxysilyl)propyl]disulfide, bis[3-(triethoxysilyl)propyl]tetrasulfide, di-tert-butoxydiacetyloxy Silane, diisobutoxyaluminoxytriethoxysilane, phenylsilanetriol, methylphenylsilanediol, ethylphenylsilanediol, n-propylphenylsilanediol, isopropylphenylsilanediol, n-butylphenylsilanediol, isobutylphenylsilanediol, tert-butylphenylsilanediol, diphenylsilanediol, trimethoxyphenylsilane, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, trimethoxy(p-tolyl)silane, ethylmethylphenylsilanol, n-propylmethylphenylsilanol, isopropylmethyl Phenylsilanol, n-butylmethylphenylsilanol, isobutylmethylphenylsilanol, t-butylmethylphenylsilanol, ethyl-n-propylphenylsilanol, ethyl-isopropylphenylsilanol, n-butylethylphenylsilanol, isobutylethylphenylsilanol, t-butylethylphenylsilanol, methyldiphenylsilanol, ethyldiphenylsilanol, n-propyldiphenylsilanol, isopropyldiphenylsilanol, n-butyldiphenylsilanol, isobutyldiphenylsilanol, t-butyldiphenylsilanol, triphenylsilanol, and the like are not limited thereto.

The silane coupling agents listed above may be used alone or in combination. Among the silane coupling agents listed above, preferred from the viewpoint of preservation stability are phenylsilanetriol, trimethoxyphenylsilane, trimethoxy(p-tolyl)silane, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol, and the following formula: [Chemical 28] Silane coupling agent having the structure shown.

When a silane coupling agent is used, the content is preferably 0.01 to 20 parts by mass based on 100 parts by mass of the polyimide precursor (A), from the viewpoint of adhesion and compatibility with aluminum.

Heterocyclic Compounds The negative photosensitive resin composition of this embodiment may also contain a heterocyclic compound. The addition of a heterocyclic compound can improve the adhesion between the cured film produced from the photosensitive resin composition and aluminum. Examples of heterocyclic compounds include azole compounds and purine derivatives. Specific examples of azole compounds include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-tert-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)]-triazole, [C]-benzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-tert-pentyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxyl-1H-benzotriazole, 5-carboxyl-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, 1-methyl-1H-tetrazole, etc.

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

Among heterocyclic compounds, 5-amino-1H-tetrazole and 8-azaadenine are preferred from the perspective of adhesion. These heterocyclic compounds may be used alone or as a mixture of two or more. When the photosensitive resin composition contains a heterocyclic compound, the content is preferably 0.1 to 10 parts by mass per 100 parts by mass of the polyimide precursor (A). From the perspective of adhesion to aluminum, it is more preferably 0.5 to 5 parts by mass.

・Thermoalkali Generator The negative photosensitive resin composition of this embodiment may also contain a thermoalkali generator. A thermoalkali generator is a compound that generates a base upon heating. The inclusion of a thermoalkali generator can further promote the imidization of the photosensitive resin composition. The type of thermoalkali generator is not particularly limited, and examples include amine compounds protected by a tert-butoxycarbonyl group and the thermoalkali generator disclosed in International Publication No. 2017/038598. However, the composition is not limited to these, and other known thermoalkali generators may also be used.

Examples of the amine compound protected by the tert-butoxycarbonyl group include ethanolamine, 3-amino-1-propanol, 1-amino-2-propanol, 2-amino-1-propanol, 4-amino-1-butanol, 2-amino-1-butanol, 1-amino-2-butanol, 3-amino-2,2-dimethyl-1-propanol, 4-amino-2-methyl-1-butanol, hydroxyamino alcohol, and 3-amino-1,2-propanediol. , 2-amino-1,3-propanediol, tyramine, demethylephedrine, 2-amino-1-phenyl-1,3-propanediol, 2-aminocyclohexanol, 4-aminocyclohexanol, 4-aminocyclohexaneethanol, 4-(2-aminoethyl)cyclohexanol, N-methylethanolamine, 3-(methylamino)-1-propanol, 3-(isopropylamino)propanol, N-cyclohexylethanolamine, α-[2-(methylamino)ethyl]- ]Benzyl alcohol, diethanolamine, diisopropanolamine, 3-pyrrolidinol, 2-pyrrolidinolmethanol, 4-hydroxypiperidine, 3-hydroxypiperidine, 4-hydroxy-4-phenylpiperidine, 4-(3-hydroxyphenyl)piperidine, 4-piperidinemethanol, 3-piperidinemethanol, 2-piperidinemethanol, 4-piperidineethanol, 2-piperidineethanol, 2-(4-piperidinyl)-2-propanol, 1,4-butanol bis(3-aminopropyl) ether, 1,2 -bis(2-aminoethoxy)ethane, 2,2'-oxybis(ethylamine), 1,14-diamino-3,6,9,12-tetraoxotetradecane, 1-aza-15-crown-5, diethylene glycol bis(3-aminopropyl) ether, 1,11-diamino-3,6,9-trioxaundecane, or compounds in which the amino group of an amino acid and its derivatives is protected by a t-butoxycarbonyl group, but are not limited thereto.

The content of the hot alkali generator is preferably 0.1 to 30 parts by mass, more preferably 1 to 20 parts by mass, based on 100 parts by mass of the polyimide precursor (A). The above amount is preferably 0.1 parts by mass or more to promote the imidization effect, and is preferably 30 parts by mass or less to improve the physical properties of the photosensitive resin layer after curing of the negative photosensitive resin composition.

Hindered Phenol Compounds The negative photosensitive resin composition of this embodiment may optionally contain a hindered phenol compound to suppress discoloration on the substrate surface. The hindered phenol compound is not limited, and examples thereof include: 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-butyl-hydroquinone, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl 2,2-Dithio-ethylidene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-phenylpropionamide), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tris-(3,5-di-tert-butyl-4-hydroxyphenyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, etc.

Examples of hindered phenol compounds include 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-isopropylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-sec-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, ,6-dimethylbenzyl]-1,3,5-tri-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-triethylmethyl-3-hydroxyl-2,6-dimethylbenzyl]-1,3,5-tri-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-tri-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-3-hydroxyl-2,5,6-trimethylbenzyl)-1,3,5-tri-2,4,6-(1H,3H,5H)-trione, 1, 3,5-Tris(4-tert-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)- The present invention also includes, but is not limited to, 1,3,5-tris(4-tert-butyl-3-hydroxyl-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-3-hydroxyl-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-3-hydroxyl-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-3-hydroxyl-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-5-ethyl-3-hydroxyl-2- ...

Among them, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione is particularly preferred.

The content of the hindered phenol compound is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the polyimide precursor (A). From the perspective of photosensitivity, it is more preferably 0.5 to 10 parts by mass. When the content of the hindered phenol compound is 0.1 parts by mass or greater relative to 100 parts by mass of the polyimide precursor (A), for example, when the photosensitive resin composition of this embodiment is formed on a copper or copper alloy substrate, discoloration and corrosion of the copper or copper alloy can be prevented. On the other hand, when the content is 20 parts by mass or less, excellent photosensitivity is achieved.

Organic Titanium Compound The negative photosensitive resin composition of this embodiment may also contain an organic titanium compound. The inclusion of an organic titanium compound allows the formation of a photosensitive resin layer with excellent chemical resistance, even when curing at low temperatures.

Examples of usable organic titanium compounds include organic chemical substances bonded to titanium atoms via covalent bonds or ionic bonds.

Specific examples of organic titanium compounds are shown below in I) to VII): I) Titanium Chelate Compounds: Among titanium chelate compounds, titanium chelate compounds having two or more alkoxy groups are preferred because they can provide the storage stability of the negative photosensitive resin composition and a good relief pattern. Specific examples include titanium bis(triethanolamine)diisopropylate, titanium bis(2,4-pentanedioate)di-n-butanol, titanium bis(2,4-pentanedioate)diisopropylate, titanium bis(tetramethylpimelate)diisopropylate, and titanium diisopropylatedi(ethyl acetylacetate).

II) Tetraalkoxytitanium compounds: for example, titanium tetra-n-butoxide, titanium tetraethanol, titanium tetra(2-ethylhexanol), titanium tetraisobutoxide, titanium tetraisopropoxide, titanium tetramethanol, titanium tetramethoxypropoxide, titanium tetramethylphenol, titanium tetra-n-nonoxide, titanium tetra-n-propoxide, titanium tetrastearyl alcohol, and titanium tetra[bis{2,2-(allyloxymethyl)butanol}].

III) Titanium cyclopentadienyl compounds: for example, titanium (pentamethylcyclopentadienyl) trimethoxide, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluorophenyl)titanium, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium, and the like.

IV) Monoalkoxy titanium compounds: for example, titanium tris(dioctyl phosphate) isopropylate, titanium tris(dodecylbenzenesulfonate) isopropylate, etc.

V) Titanium oxide compounds: for example, bis(glutaric acid)titanium oxide, bis(tetramethylpimelic acid)titanium oxide, phthalocyanine titanium oxide, etc.

VI) Titanium tetraacetylpyruvate compound: for example, titanium tetraacetylpyruvate.

VII) Titanium ester coupling agent: for example, isopropyl tri(dodecylbenzenesulfonyl) titanium ester.

Among these, from the perspective of exhibiting better chemical resistance, the organic titanium compound is preferably at least one compound selected from the group consisting of I) titanium chelate compounds, II) tetraalkoxytitanium compounds, and III) titaniumocene compounds. Particularly preferred are titanium diisopropylate bis(ethyl acetylacetate), titanium tetra-n-butoxide, and bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium.

The content of the organic titanium compound is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the polyimide precursor (A). When the content is 0.05 parts by mass or greater, good heat resistance and chemical resistance are exhibited. On the other hand, when the content is 10 parts by mass or less, excellent storage stability is achieved.

Sensitizers The negative photosensitive resin composition of this embodiment may optionally contain a sensitizer to increase photosensitivity. Examples of such sensitizers include: Michler's ketone, 4,4'-bis(diethylamino)benzophenone, 2,5-bis(4'-diethylaminobenzylidene)cyclopentane, 2,6-bis(4'-diethylaminobenzylidene)cyclohexanone, 2,6-bis(4'-diethylaminobenzylidene)-4-methylcyclohexanone, 4,4'-bis(dimethylamino)chalcone, 4,4'-bis(diethylamino)chalcone, p-dimethylaminobenzene, Allylene dihydroindanone, p-dimethylaminobenzylidene dihydroindanone, 2-(p-dimethylaminophenylbenzene)-benzothiazole, 2-(p-dimethylaminophenylvinylene)benzothiazole, 2-(p-dimethylaminophenylvinylene)isonaphthothiazole, 1,3-bis(4'-dimethylaminobenzylidene)acetone, 1,3-bis(4'-diethylaminobenzylidene)acetone, 3,3'-carbonyl-bis(7-diethylamino)-benzothiazole Benzyl coumarin), 3-acetyl-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- Benzophenone, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 2-benzimidazole, 1-phenyl-5-benzyltetrazol, 2-benzylbenzimidazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, 2-(p-dimethylaminobenzyl)styrene, etc. These can be used alone or in combinations of 2 to 5.

When the photosensitive resin composition contains a sensitizer for improving photosensitivity, the content of the sensitizer is preferably 0.1 to 25 parts by mass relative to 100 parts by mass of the polyimide precursor (A).

Polymerization Inhibitor To improve the viscosity and photosensitivity stability of the negative photosensitive resin composition, particularly when stored as a solution containing a solvent, the negative photosensitive resin composition of this embodiment may optionally contain a polymerization inhibitor. Polymerization inhibitors that can be used include: hydroquinone, N-nitrosodiphenylamine, 4-tert-butylcatechol, phenanthridine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-4-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, N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt, etc.

Thermal Crosslinking Agent The negative photosensitive resin composition of this embodiment may optionally contain a thermal crosslinking agent to improve the heat resistance of the cured film. Examples of thermal crosslinking agents having one thermal crosslinking group include ML-26X, ML-24X, ML-236TMP, 4-Methylol 3M6C, ML-MC, and ML-TBC (all trade names, manufactured by Honshu Chemical Industry Co., Ltd.), and P-a Benzoxazine (trade name, manufactured by Shikoku Chemical Industry Co., Ltd.). Examples of compounds having two thermally crosslinkable groups include DM-BI25X-F, 46DMOC, 46DMOIPP, and 46DMOEP (trade names, manufactured by Asahi Chemical Industries, Ltd.), DML-MBPC, DML-MBOC, DML-OCHP, DML-PC, DML-PCHP, DML-PTBP, DML-34X, DML-EP, DML-POP, DML-OC, Dimethylol-Bis-C, Dimethylol-BisOC-P, DML-BisOC-Z, DML-BisOCHP-Z, DML-PFP, DML-PSBP, DML-MB25, DML-MTrisPC, DML-Bis25X-34XL, and DML-Bis25X-PCHP (trade names, manufactured by Honshu Chemical Industries, Ltd.), and NIKALAC MX-290 (trade name, manufactured by SANWA Chemical Co., Ltd.), B-a Benzoxazine, B-m Benzoxazine (all trade names, manufactured by Shikoku Chemical Co., Ltd.), 2,6-dimethoxymethyl-4-tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diethoxymethyl-p-cresol, etc. Examples of products with three thermally crosslinkable groups include TriML-P, TriML-35XL, and TriML-TrisCR-HAP (all trade names, manufactured by Honshu Chemical Co., Ltd.). Examples of compounds with four thermally crosslinkable groups include TM-BIP-A (trade name, manufactured by Asahi Organic Materials Co., Ltd.), TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, and TMOM-BP (trade names, manufactured by Honshu Chemical Industry Co., Ltd.), and NIKALAC MX-280 and NIKALAC MX-270 (trade names, manufactured by Sanwa Chemical Co., Ltd.). Examples of compounds with six thermally crosslinkable groups include HML-TPPHBA and HML-TPHAP (trade names, manufactured by Honshu Chemical Industry Co., Ltd.), and NIKALAC MW-390 and NIKALAC MW-100LM (trade names, manufactured by Sanwa Chemical Co., Ltd.). Among them, in the present embodiment, those containing at least two thermally crosslinkable groups are preferred, and more preferred are 46DMOC, 46DMOEP (trade names, manufactured by Asahi Organic Materials Industry Co., Ltd.), DML-MBPC, DML-MBOC, DML-OCHP, DML-PC, DML-PCHP, DML-PTBP, DML-34X, DML-EP, DML-POP, Dimethylol-BisOC-P, DML-PFP, DML-PSBP, DML-MTrisPC (trade names, manufactured by Honshu Chemical Industry Co., Ltd.), NIKALAC MX-290 (trade name, manufactured by SANWA Chemical Co., Ltd.), B-a type Benzoxazine, B-m type Benzoxazine (these are trade names, manufactured by Shikoku Chemical Industry Co., Ltd.), 2,6-dimethoxymethyl-4-tert-butylphenol, 2,6-dimethoxymethyl-p-cresol, 2,6-diethoxymethyl-p-cresol, etc., TriML-P, TriML-35XL (these are trade names, manufactured by Honshu Chemical Industry Co., Ltd.), etc., TM-BIP-A (these are trade names, manufactured by Asahi Chemical Industry Co., Ltd.), TML-BP, TML-HQ, TML-pp-BPF, TML-BPA, TMOM-BP (these are trade names, manufactured by Honshu Chemical Industry Co., Ltd.), NIKALAC MX-280, NIKALAC MX-270 (these are trade names, manufactured by SANWA CHEMICAL (manufactured by Honshu Chemical Co., Ltd.), HML-TPPHBA, HML-TPHAP (trade names, manufactured by Honshu Chemical Co., Ltd.), etc. Further preferred examples include NIKALAC MX-290, NIKALAC MX-280, NIKALAC MX-270 (trade names, manufactured by Sanwa Chemical Co., Ltd.), B-a type Benzoxazine, B-m type Benzoxazine (trade names, manufactured by Shikoku Chemical Co., Ltd.), NIKALAC MW-390, NIKALAC MW-100LM (trade names, manufactured by Sanwa Chemical Co., Ltd.), etc. To improve the heat resistance of the cured film, the thermal crosslinker content is preferably 0.5 to 20 parts by mass, more preferably 2 to 10 parts by mass, per 100 parts by mass of the polyimide precursor (A). A content of 0.5 parts by mass or greater exhibits excellent heat resistance, while a content of 20 parts by mass or less exhibits excellent storage stability.

<Method for manufacturing a hardened relief pattern and semiconductor device> The method for manufacturing a hardened relief pattern of this embodiment includes: (1) forming a photosensitive resin layer on a substrate by applying the negative photosensitive resin composition of this embodiment to a substrate; (2) exposing the photosensitive resin layer; (3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) hardening the relief pattern by heating the relief pattern.

(1) Photosensitive resin layer formation step In this step, the negative photosensitive resin composition of this embodiment is applied to the substrate and then dried as needed to form a photosensitive resin layer. The coating method can be a method previously used for coating photosensitive resin compositions, such as a method using a rotary coater, a rod coater, a doctor blade coater, a curtain coater, a screen printer, or a spray coater.

(2) Exposure Step In this step, the photosensitive resin layer formed above is exposed using an exposure device such as a contact aligner, a mirror projection exposure machine, or a stepper, through a patterned mask or a multiplying mask, or directly using an ultraviolet light source.

(3) Relief pattern formation step In this step, the unexposed portion of the exposed photosensitive resin layer is developed and removed. As a developing method for developing the exposed (irradiated) photosensitive resin layer, any method can be selected from previously known photoresist developing methods such as a rotary spray method, a liquid coating method, and an immersion method accompanied by ultrasonic treatment. In addition, after development, for the purpose of adjusting the shape of the relief pattern, a post-development baking can be performed according to any combination of temperature and time as needed.

The developer used for development is preferably a good solvent for the negative photosensitive resin composition, or a combination of such a good solvent and a poor solvent. Preferred good solvents include NMP, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, and α-acetyl-γ-butyrolactone. Preferred poor solvents include toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol monomethyl ether acetate, and water. When a good solvent and a poor solvent are mixed, the ratio of the poor solvent to the good solvent is preferably adjusted based on the solubility of the polymer in the negative photosensitive resin composition. Furthermore, two or more solvents, for example, several solvents, may be used in combination.

(4) Relief pattern hardening step In this step, the relief pattern obtained by the above-mentioned development is subjected to a heat treatment to dilute the photosensitive component and imidize the (A) polyimide precursor, thereby hardening the relief pattern and converting it into a hardened relief pattern containing polyimide. As a method of heat treatment, various methods can be selected, such as a method using a hot plate, a method using an oven, and a method using a temperature-programmable rising oven. The heat treatment can be carried out, for example, at 160°C to 350°C for 30 minutes to 5 hours. The temperature of the heat treatment is preferably not less than 200°C and not more than 280°C. The time of the heat treatment is preferably not less than 0.5 hours and not more than 10 hours. The atmosphere used during heat curing can be air, or inert gases such as nitrogen and argon.

<Semiconductor Device> This embodiment also provides a semiconductor device having a hardened relief pattern obtained by the above-described method for producing a hardened relief pattern. Thus, a semiconductor device can be provided having a substrate serving as a semiconductor element and a hardened relief pattern of polyimide formed on the substrate by the above-described method for producing a hardened relief pattern. Furthermore, the present invention can be applied to a method for producing a semiconductor device using a semiconductor element as a substrate and including the above-described method for producing a hardened relief pattern of this embodiment as a step. Semiconductor devices can be manufactured by forming the hardened relief pattern formed using the method for manufacturing a hardened relief pattern according to this embodiment into a surface protective film, an interlayer insulating film, a redistribution insulating film, a flip-chip device protective film, or a protective film for a semiconductor device with a bump structure, and combining this method with a conventional semiconductor device manufacturing method. The negative photosensitive resin composition according to this embodiment is preferably used as a negative photosensitive resin composition for forming surface protective films, interlayer insulating films, redistribution insulating films, a flip-chip device protective film, or a protective film for a semiconductor device with a bump structure.

<Display Device> In this embodiment, a display device is provided, comprising a display element and a cured film disposed on the display element, wherein the cured film comprises the aforementioned hardened relief pattern. The hardened relief pattern may be deposited directly in contact with the display element or via another layer. Examples of such cured films include surface protective films, insulating films, and planarizing films for TFT liquid crystal display elements and color filter elements, protrusions for MVA liquid crystal display devices, and spacers for cathodes in organic EL elements.

The negative photosensitive resin composition of this embodiment is preferably used to form insulating members or interlayer insulating films. In addition to being used in semiconductor devices as described above, the negative photosensitive resin composition of this embodiment can also be used for interlayer insulating films in multilayer circuits, top coatings for flexible copper foils, solder resist films, and liquid crystal alignment films. [Examples]

The present invention is described in detail below using examples, but the present invention is not limited thereto. In the examples, comparative examples, and preparation examples, the physical properties of the polymer or negative photosensitive resin composition were measured and evaluated according to the following methods.

(1) Weight Average Molecular Weight The weight average molecular weight (Mw) of each photosensitive resin composition was determined using gel permeation chromatography (standard polystyrene conversion) under the following conditions.

Pump: JASCO PU-980 Detector: JASCO RI-930 Column Oven: JASCO CO-965 40°C Column: Two Shodex KD-806M columns in series, manufactured by Showa Denko Co., Ltd., or Shodex 805M/806M columns in series, manufactured by Showa Denko Co., Ltd. Standard Monodisperse Polystyrene: Shodex STANDARD SM-105, manufactured by Showa Denko Co., Ltd. Mobile Phase: 0.1 mol/L LiBr/N-methyl-2-pyrrolidone (NMP) Flow Rate: 1 mL/min.

(2) Evaluation of the resolution of the hardened relief pattern (polyimide coating) The photosensitive resin composition was spin-coated onto a 6-inch silicon wafer (manufactured by Fujimi Electronic Industry Co., Ltd., thickness 625±25 μm) using a coating developer (D-Spin60A model, manufactured by SOKUDO Corporation) to a film thickness of approximately 10 μm, and pre-baked at 110°C for 240 seconds using a hot plate to form a coating. The coating was exposed to i-rays at an exposure wavelength of 365 nm using a stepper NSR2005i11A (manufactured by Nikon Corporation) through a multiplying mask with a test pattern attached, with i-rays irradiated at a step size of 50 mJ/ ^cm2 from an exposure dose of 400 mJ/ ^cm2 to 700 mJ/ ^cm2 . Next, a coating developer (D-Spin 60A, manufactured by SOKUDO) was used at 23°C using cyclopentanone as the developer solution. Development was performed by rotary spray for 1.4 times the time required to completely dissolve the unexposed areas. This was followed by rotary spray rinsing with propylene glycol monomethyl ether acetate for 10 seconds to obtain a relief pattern containing the resin film. Subsequently, the film was cured in a vertical curing oven (VF200B, manufactured by Koyo Thermo Systems) at 280°C for 2 hours under a nitrogen atmosphere to obtain a hardened relief pattern.

Each pattern obtained is observed under an optical microscope for pattern shape or pattern width, and the resolution is determined. Regarding resolution, a pattern with multiple openings of varying areas is formed using the same method as above by exposing through a reduced mask with a test pattern attached. If the area of the resulting pattern opening is at least 1/2 the area of the corresponding pattern mask opening, the pattern is considered resolved. The length of the mask opening corresponding to the smallest area of the resolved opening is used as the resolution. The exposure that yields the best resolution is designated as the optimal exposure, and the pattern accuracy is evaluated based on the following criteria. A rating of A to C indicates that the pattern is suitable for use as a hardened relief pattern for semiconductors.

A: The pattern cross-section is not wavy, and there are no planing marks, swelling, or bridging at the bottom. The resolution is 9 μm or less. B: The pattern cross-section is not wavy, and there are no planing marks, swelling, or bridging at the bottom. The resolution is 10 μm or less. C: The pattern cross-section is not wavy, and there are no planing marks, swelling, or bridging at the bottom. The resolution is 12 μm or less. D: None of conditions A to C are met.

(3) Evaluation of the Young's modulus of the hardened relief pattern (polyimide coating) The photosensitive resin composition was spin-coated onto a 6-inch silicon wafer (manufactured by Fujimi Electronic Industry Co., Ltd., thickness 625±25 μm) using a coating developer (D-Spin60A, manufactured by SOKUDO) to a film thickness of approximately 10 μm. The film was then pre-baked at 110°C for 240 seconds using a hot plate to form a coating. The entire surface was then exposed to 800 mJ/ ^cm² using a parallel beam mask alignment exposure system (PLA-501FA, manufactured by Canon). The film was then heated at 280°C for two hours in a programmable curing oven (VF-2000, manufactured by Koyo Lindberg) under a nitrogen atmosphere to produce a hardened relief pattern (thermocured polyimide coating). The resulting polyimide coating was cut into 3 mm wide strips using a dicing machine (DAD3350, manufactured by DISCO). These strips were then peeled from the silicon wafer using 46% hydrofluoric acid to produce polyimide tapes. The Young's modulus of the obtained polyimide tape was measured using a tensile tester (UTM-II-20, manufactured by Orientec) according to ASTM D882-09 and evaluated according to the following criteria. A rating of A to C indicates that the tape is suitable for use as a hardening film for semiconductors.

A: Young's modulus 6.5 GPa or higher B: Young's modulus 6.0 GPa or higher but less than 6.5 GPa C: Young's modulus 5.0 GPa or higher but less than 6.0 GPa D: Young's modulus less than 5.0 GPa

(4) Evaluation of Adhesion with Aluminum A 100 nm thick aluminum (Al) was sputter-coated on a 6-inch silicon wafer (Fujimi Electronic Industry Co., Ltd., thickness 625 ± 25 μm) using a sputtering device (L-440S-FHL, Canon Anelva). Subsequently, a photosensitive resin composition was spin-coated onto the wafer using a coating developer (D-Spin60A, SOKUDO) to a film thickness of approximately 10 μm. The film was pre-baked at 110°C for 240 seconds using a hot plate to form a coating. The entire surface was then exposed and heated at 280°C for two hours in a nitrogen atmosphere using a programmable curing furnace (VF-2000, manufactured by Koyo Lindberg) to obtain a hardened relief pattern (thermocured polyimide coating). The heat-treated film was evaluated for adhesion between the aluminum substrate and the hardened resin coating using the cross-cut method according to JIS K 5600-5-6, based on the following criteria. A rating of A to B indicates that the film is suitable for use as a hardened film for semiconductors.

A: The number of grids in the cured resin coating layer adjacent to the substrate is between 80 and 100. B: The number of grids in the cured resin coating layer adjacent to the substrate is between 40 and 80. C: The number of grids in the cured resin coating layer adjacent to the substrate is less than 40.

<Preparation Example 1> Synthesis of Polymer A1 as a Precursor for Polyimide (A) 155 g (0.5 mol) of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 2-L separable flask. 135 g (0.2 mol) of 2-hydroxyethyl methacrylate (HEMA) and 400 ml of γ-butyrolactone were added and stirred at room temperature. While stirring, 79.1 g of pyridine was added. After stirring for 16 hours, a reaction mixture was prepared.

Next, under ice cooling, a solution of 203 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes while stirring. This was followed by a suspension of 48 g (0.44 mol) of p-phenylenediamine (pPD) in 280 ml of γ-butyrolactone, also added over 60 minutes while stirring. The mixture was stirred at room temperature for 4 hours, followed by the addition of 40 ml of ethanol and stirring for 1 hour. Next, 1 liter of γ-butyrolactone was added. The precipitate from the reaction mixture was removed by filtration to obtain a reaction solution.

The resulting reaction solution was added to 4 liters of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 2.5 liters of tetrahydrofuran to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 30 liters of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polymer (Polymer A1). The molecular weight of Polymer A1 was determined by gel permeation chromatography (standard polystyrene conversion), and the weight average molecular weight (Mw) was 18,000.

<Preparation Example 2> Synthesis of Polymer A2 as a Precursor for Polyimide (A) The reaction was carried out in the same manner as described in Preparation Example 1, except that 94 g (0.44 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl (mTB: m-tolidine) was used in place of 48 g (0.44 mol) of p-phenylenediamine (pPD) in Preparation Example 1. Polymer A2 was obtained. The molecular weight of Polymer A2 was measured by gel permeation chromatography (based on standard polystyrene) and the weight-average molecular weight (Mw) was 24,000.

Preparation Example 3: Synthesis of Polymer A3 as a Precursor for Polyimide (A) The reaction was conducted in the same manner as in Preparation Example 1, except that 108 g (0.5 mol) of pyromellitic dianhydride (PMDA) was used in place of 155 g (0.5 mol) of 4,4'-oxydiphthalic dianhydride (ODPA) in Preparation Example 1, and 94 g (0.44 mol) of 2,2'-dimethyl-4,4'-diaminobiphenyl (mTB: m-tolidine) was used in place of 48 g (0.44 mol) of p-phenylenediamine (pPD). Polymer A3 was obtained. The molecular weight of Polymer A3 was measured by gel permeation chromatography (based on standard polystyrene) and the weight-average molecular weight (Mw) was 22,000.

<Preparation Example 4> Synthesis of Polymer A4 as a Precursor for Polyimide (A) The reaction was carried out in the same manner as described in Preparation Example 1, except that 140 g (0.44 mol) of 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl (TFMB) was used in place of 48 g (0.44 mol) of p-phenylenediamine (pPD) in Preparation Example 1. Polymer A4 was obtained. The molecular weight of Polymer A4 was measured by gel permeation chromatography (based on standard polystyrene) and the weight-average molecular weight (Mw) was 24,000.

<Preparation Example 5> Synthesis of Polymer A5 as a Precursor for Polyimide (A) The reaction was carried out in the same manner as described in Preparation Example 4, except that 147 g (0.5 mol) of 3,3'-,4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used in place of 155 g (0.5 mol) of 4,4'-oxydiphthalic dianhydride (ODPA) to obtain Polymer A5. The molecular weight of Polymer A5 was measured by gel permeation chromatography (based on standard polystyrene) and the weight-average molecular weight (Mw) was 24,000.

<Preparation of Photosensitive Resin Composition> Each compound was weighed according to the ratio listed in Table 1 and dissolved in a solvent (D) consisting of a mixture of GBL (D1) and DMSO (D2) at a weight ratio of 80:20 to obtain a solution. The viscosity of the resulting solution was adjusted to approximately 40 poise by adding the necessary amount of solvent (D) (80:20) of GBL (D1):DMSO (D2) to prepare a photosensitive resin composition. This composition was evaluated according to the above method, and the results are shown in Table 1. The values listed in Table 1 are parts by mass. For each compound (A) to (F) listed in Table 1, the freezing point or melting point and the number of repetitions of the unit structure of a portion of the compound (B) plasticizer and (F) other additives are listed in Table 2. Furthermore, the structures of the substituents and other components of the plasticizer (B) represented by formula (3) are shown in Table 3. Furthermore, F4 and F5, which are other additives (F) in Table 2, are conventional plasticizers that do not conform to the plasticizer (B) of this embodiment. Furthermore, although F6 to F8 do not conform to the plasticizer (B) of this embodiment, they are compounds having structures similar to the plasticizer (B) of this embodiment in terms of having compounds or repeating units represented by general formula (3).

[Table 1-A] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 (A) Polyimide precursor A1 100 100 A2 100 100 100 100 100 100 100 100 100 100 A3 A4 A5 (B) Plasticizer B1 15 B2 15 15 3 30 10 10 B3 5 B4 B5 15 B6 5 B7 10 B8 10 (C) Photopolymerization initiator C1 5 5 5 5 5 5 5 5 5 5 5 5 (D) Solvent D1 100 100 100 100 100 100 100 100 100 100 100 100 D2 25 25 25 25 25 25 25 25 25 25 25 25 (E) Radically polymerizable compound E1 5 E2 E3 E4 (F) Other additives F1 10 10 10 10 10 10 10 10 10 10 10 10 F2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 F3 5 5 5 5 5 5 5 5 5 5 5 5 F4 F5 F6 F7 F8 Evaluation results Aluminum adhesion A A A B A B B B A A A A Young's modulus C C B C B B C C B B B B resolution B A B B C B B C C B B A

[Table 1-B] Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 (A) Polyimide precursor A1 100 100 100 100 100 A2 100 100 100 A3 100 100 100 100 100 A4 100 A5 100 (B) Plasticizer B1 B2 15 40 10 10 10 B3 5 10 B4 15 B5 B6 B7 B8 (C) Photopolymerization initiator C1 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 (D) Solvent D1 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 D2 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 (E) Radically polymerizable compound E1 15 E2 5 E3 5 E4 5 (F) Other additives F1 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 F2 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 F3 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 F4 15 F5 15 F6 15 F7 15 F8 15 Evaluation results Aluminum adhesion B B A A B A A A C B C B C C C Young's modulus A C C C B B B B D D C D B B B resolution C B C C C A A A B D D C D D D

[Table 2] Freezing point (℃) Melting point (℃) Number of repetitions of unit structure (A) Polyimide precursor A1 Preparation of the polyimide precursor described in Example 1 - - - A2 Preparation of the polyimide precursor described in Example 2 - - - A3 Preparation of the polyimide precursor described in Example 3 - - - A4 Preparation of the polyimide precursor described in Example 4 - - - A5 Preparation of the polyimide precursor described in Example 5 - - - (B) Plasticizer B1 Polyoxyethylene monomethyl ether, Mw 400 (Trade name: Uniox M-400, manufactured by NOF Corporation) 0 - 8 B2 Polyoxyethylene dimethyl ether, Mw 400 (Trade name: Uniox MM-400, manufactured by NOF Corporation) 5 - 8 B3 Polyoxyethylene monomethyl ether, Mw 1000 (Trade name: Uniox M-1000, manufactured by NOF Corporation) 40 - twenty two B4 Polyethylene glycol, Mw 400 (trade name: PEG#400, manufactured by NOF Corporation) 6 - 9 B5 Polyethylene glycol, Mw 300 (trade name: PEG#300, manufactured by NOF Corporation) -8 - 6 B6 Polyoxyethylene monomethyl ether, Mw 2000 (Trade name: Uniox M-2000, manufactured by NOF Corporation) 50 - 45 B7 Polytetramethylene glycol, Mw 650 (trade name: PTMG650, manufactured by Mitsubishi Chemical Co., Ltd.) 11 - 9 B8 Polypropylene glycol, Mw 400 (Trade name: Uniol D-400G, manufactured by NOF Corporation) -31 -31 7 (C) Photopolymerization initiator C1 2-[[(Ethoxycarbonyl)oxy]imino]-1-phenylpropan-1-one (trade name: Speed Cure PDO, manufactured by Lambson) - - - (D) Solvent D1 γ-Butyrolactone (Mitsubishi Chemical Co., Ltd.) - - - D2 Dimethyl sulfoxide (manufactured by Toray Fine Chemicals) - - - (E) Radical polymerizable compound E1 Tetraethylene glycol dimethacrylate (trade name: NK Ester 4G, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) - - - E2 Tricyclodecanedimethanol diacrylate (trade name: NK Ester A-DCP, manufactured by Shin-Nakamura Chemical Industries, Ltd.) - - - E3 Ethoxylated bisphenol A dimethacrylate (trade name: NK Ester BPE-500, manufactured by Shin-Nakamura Chemical Industries, Ltd.) - - - E4 Tris-(2-acryloyloxyethyl) isocyanurate (trade name: NK Ester A-9300, manufactured by Shin-Nakamura Chemical Industries, Ltd.) - - - (F) Other additives F1 N-phenyldiethanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.) - - - F2 N-[3-(Triethoxysilyl)propyl]phthalamide - - - F3 Methylated urea resin (trade name: NIKALAC MX-290, manufactured by SANWA CHEMICAL Co., Ltd.) - - - F4 Di-2-ethylhexyl phthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) -50 -50 1 F5 Dicyclohexyl phthalate - 66 1 F6 Dipropylene glycol methyl ether acetate - -25 2 F7 Tripropylene glycol methyl ether -78 -78 3 F8 Tripropylene glycol butyl ether -75 -75 3

[Table 3] General formula (3) a+b n ₂ R ₆ R ₇ R _6' R _7' R ₈ R ₉ B1 2 8 H H H H CH ₃ H B2 2 8 H H H H CH ₃ CH ₃ B3 2 twenty two H H H H CH ₃ H B4 2 9 H H H H H H B5 2 6 H H H H H H B6 2 45 H H H H CH ₃ H B7 4 9 H H H H H H B8 2 (a＝1，b＝1) 7 CH ₃ H H H H H

The evaluation results in Table 1 show that Comparative Examples 1-7, which do not meet the requirements of this embodiment, fail to achieve a well-balanced performance in terms of aluminum adhesion, Young's modulus, and resolution. On the other hand, Examples 1-20 all demonstrate excellent performance in terms of aluminum adhesion, Young's modulus, and resolution. Comparisons of Comparative Examples 1, 2, and 4 with Example 2, and of Comparative Examples 3, 5, 6, and 7 with Example 13 demonstrate that the use of the plasticizer (B), a requirement of this embodiment, improves aluminum adhesion, Young's modulus, and resolution. Comparative Example 2 or Comparative Examples 4 to 7 contain compounds generally referred to as plasticizers or compounds having a structure similar to the plasticizer (B) of this embodiment. However, it is speculated that because they do not meet the freezing point or melting point specified in this embodiment, or the number of repetitions of the unit structure or the structure represented by general formula (3), they do not achieve a sufficient plasticizing effect or compatibility with other composition components, and thus fail to achieve the effects of improving adhesion to aluminum, Young's modulus, and resolution.

Comparing Example 2 with Example 3, Example 3, in which _Y1 of the polyimide precursor (A) comprises A2 of the general formula (4), exhibits superior Young's modulus. Furthermore, comparing Example 11 with Example 12 and Examples 18-20, Example 12 and Examples 18-20, in which the radically polymerizable compound (E) is included, exhibit superior resolution. The detailed structures of the plasticizer (B) are compared. Comparing Examples 1, 2, and 15, it is found that Examples 1 and 2, in which the plasticizer (B) comprises a plasticizer having a structure represented by Formula (3) and R ₈ and/or R ₉ is an alkyl group, exhibit good resolution, and Example 2, in which both R ₈ and R ₉ are alkyl groups, exhibits even better resolution. Furthermore, comparing Examples 9 with Examples 10 and 11, it is found that Examples 10 and 11, in which the plasticizer (B) comprises a plasticizer having a structure represented by Formula (3) and a total of 2 to 3 for a and b, exhibit good resolution. This is presumably because the plasticizer (B) has better compatibility with the photosensitive resin composition, resulting in improved resolution. When comparing Example 3 with Example 7, and Example 6 with Example 8, respectively, Example ₃ (n2 is 8) and Example 6 ( _n2 is 22), in which the plasticizer (B) is a plasticizer having a structural formula represented by the general formula (3) and n2 is 8 to ₂₃ , are superior in terms of performance balance. The reason is not certain, but it is believed that if the value of n2 is larger, as in Example 8 ( _n2 is 45), the compatibility or the effect of promoting the filling of the polymer during the heat treatment is reduced, and the contribution to improving the resolution or Young's modulus is often reduced. In addition, it is speculated that even if the value of _n2 is smaller, as in Example ₇ ( _n2 is 6), a sufficient plasticizing effect is not obtained, and the effect of improving the adhesion with aluminum or the Young's modulus is reduced (Example 7). Furthermore, regarding the plasticizer (B), if it contains 5 parts by mass or more relative to 100 parts by mass of the polyimide precursor (A), it is particularly effective in improving the adhesion to aluminum or the Young's modulus (based on a comparison between Example 3 and Example 4). Furthermore, if the plasticizer (B) contains more than 30 parts by mass relative to 100 parts by mass of the polyimide precursor (A), the resolution deteriorates. Therefore, it is more preferable to contain 5 to 30 parts by mass of the plasticizer (B) (based on a comparison between Example 2 and Example 16). [Industrial Applicability]

The photosensitive resin composition of the present invention can be used to produce a hardened relief pattern with high mechanical strength (Young's modulus), excellent adhesion to aluminum, and excellent resolution. The present invention is particularly suitable for use in the field of photosensitive materials useful in the manufacture of electrical and electronic materials, such as semiconductor devices and multilayer wiring boards.

Claims (10)

A negative photosensitive resin composition comprising: (A) a resin having the following general formula (1): A polyimide precursor having a structure of {wherein, _X1 is a tetravalent organic group, _Y1 is a divalent organic group, _n1 is an integer of 2 to 150, and _R1 and _R2 are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, and at least one of _R1 and _R2 is a group having an ethylenically unsaturated bond}; (B) a plasticizer having a freezing point or melting point of not less than -40°C and having three or more repeating units; and (C) a photopolymerization initiator; wherein the plasticizer (B) is contained in an amount of 1 to 40 parts by mass per 100 parts by mass of the polyimide precursor (A). A negative photosensitive resin composition comprising: (A) a resin having the following general formula (1): A polyimide precursor having a structure of {wherein, _X1 is a tetravalent organic group, _Y1 is a divalent organic group, _n1 is an integer of 2 to 150, and _R1 and _R2 are each independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, and at least one of _R1 and _R2 is a group having an ethylenically unsaturated bond}; (B) the following general formula (3): [Chemical 3] (wherein _n2 is an integer from 6 to 45, a and b are each independently an integer from 0 to 5; provided that the total of a and b is an integer from 1 to 5; and _R6 , _R7 , R6 _' , R7 _' , _R8 , and _R9 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); and (C) a photopolymerization initiator; wherein the plasticizer (B) is contained in an amount of 1 to 40 parts by mass per 100 parts by mass of the polyimide precursor (A). The negative photosensitive resin composition of claim 1 or 2, wherein R ₁ and R ₂ in the above general formula (1) are independently hydrogen atoms, or the following general formula (2): [Chemical 4] (wherein R ₃ , R ₄ and R ₅ are independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and m ₁ is an integer from 2 to 10) a monovalent organic group represented by, or a saturated aliphatic group having 1 to 4 carbon atoms. The negative photosensitive resin composition of claim 1 or 2, wherein _Y1 in the above general formula (1) comprises a structure represented by the following general formula (4): [Chemical 5] (wherein, R ₁₀ and R ₁₁ each independently represent an alkyl group having 1 to 4 carbon atoms, a fluorine atom, or a trifluoromethyl group). The negative photosensitive resin composition of claim 1 or 2, wherein _X1 in the general formula (1) comprises at least one structure selected from the group consisting of the following general formulas (5), (6) and (7), [Chemical 6] [Chemistry 7] [Chemistry 8] . The negative photosensitive resin composition of claim 2 comprises the plasticizer (B) having a structure represented by the general formula (3) wherein _n2 is an integer of 8 to 23. The negative photosensitive resin composition of claim 1 or 2 contains 5 to 30 parts by weight of the plasticizer (B) per 100 parts by weight of the polyimide precursor (A). The negative photosensitive resin composition of claim 1 or 2, comprising a free radical polymerizable compound (E). The negative photosensitive resin composition of claim 1 or 2 is a negative photosensitive resin composition for forming a surface protective film, an interlayer insulating film, an insulating film for redistribution wiring, a protective film for a flip-chip device, or a protective film for a semiconductor device having a bump structure. A method for producing a hardened relief pattern, comprising: (1) forming a photosensitive resin layer on a substrate by coating a negative photosensitive resin composition as claimed in claim 1 or 2 on the substrate; (2) exposing the photosensitive resin layer; (3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) hardening the relief pattern by heating the relief pattern.