TWI890044B - Negative photosensitive resin composition and method for producing hardened relief pattern - Google Patents

Abstract

The present invention is to provide a negative photosensitive resin composition having high resolution, minimal film thickness variation during thermal curing, and a suitable developing time even during thin film coating. The negative photosensitive resin composition of the present invention comprises (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent. The precursor resin (A) comprises the following general formula (1): The repeating units and the following general formula (3): A polyamide-imide proto-driver resin having repeating units of formula (3), wherein the molar fraction of the repeating units of formula (3) in the proto-driver resin (A) is greater than 25% and less than 100%.

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, polybenzoxazole resins, and phenolic resins, all of which offer excellent heat resistance, electrical properties, and mechanical properties. Among these resins, photosensitive resin compositions offer the potential for easily forming heat-resistant, relief-patterned films through coating, exposure, development, and subsequent curing through a thermal imidization process. These photosensitive resin compositions significantly reduce the number of steps required compared to conventional non-photosensitive materials.

There are various semiconductor packaging methods used in semiconductor devices. For example, a so-called packaging method involves covering a semiconductor chip with a sealing structure, which then forms a redistribution layer electrically connected to the semiconductor chip. Among these semiconductor packaging methods, fan-out has become the mainstream in recent years.

In one embodiment of a fan-out semiconductor package, a semiconductor chip is covered with a sealing structure, thereby forming a chip seal larger than the size of the semiconductor chip. Furthermore, a redistribution layer is formed to the region between the semiconductor chip and the sealing structure. The redistribution layer is formed with a relatively thin film thickness. Furthermore, since the redistribution layer can be formed only to the region of the sealing structure, the number of external connection terminals can be increased. For example, the device disclosed in Patent Document 1 below is known as a fan-out semiconductor device. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2005-167191

[Identify the problem you want to solve]

In fan-out semiconductor devices, with the increase in integration and functionality and the miniaturization of chip size, the redistribution layer has a multi-layer structure. In order to form copper wiring on each layer, the insulating layer (also called "interlayer insulation film") in the redistribution layer is required to have high flatness.

Here, a negative photosensitive resin obtained by curing a polyimide precursor resin (typically composed solely of a polyamide structure) is used as the insulating layer in the redistribution layer. However, the inventors discovered that during curing, components in the film, particularly the side chains of the polyimide precursor, volatilize as the imide cyclizes. This reduces the film volume, making it difficult to achieve a flat layer because the film conforms to the uneven topography of the substrate.

Furthermore, the insulating layer is required to achieve high resolution to achieve miniaturization of copper wiring in the redistribution layer. This trend often leads to thinner insulating layers as the pattern becomes finer. However, applying a thinner layer of photosensitive resin composition significantly shortens the development time, creating a difference in the time it takes for the developer to contact the surface, leading to poor development.

The present invention was developed in light of this practical situation. Specifically, one of the objects of the present invention is to provide a negative photosensitive resin composition (also referred to as "photosensitive resin composition" in this specification) that has high resolution, minimal film thickness variation during thermal curing, and an appropriate development time even for thin film coating. Furthermore, another object of the present invention is to provide a method for producing a cured relief pattern, a method for producing polyimide, a cured polyamide-imide product, a method for producing a cured polyamide-imide product, and a semiconductor device using the negative photosensitive resin composition. [Technical Means for Solving the Problem]

The inventors of the present invention have found that the above-mentioned problem can be solved by using a polyamide-imide precursor resin having an amide structure and an imide precursor structure in its main chain to form a negative photosensitive resin composition, thereby completing the present invention. The following are examples of embodiments of the present invention. [1] A negative photosensitive resin composition comprising: (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent; The precursor resin (A) comprises the following general formula (1): [Chemical 1] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [Chemical 2] [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): [Chemical 3] [ _2] A negative photosensitive resin composition as described in item 1, wherein at least one of R 1 and R ₂ is a monovalent organic group represented by the general formula (2). [3] A negative photosensitive resin composition comprising: ( _A ) a precursor resin; (B) a photopolymerization initiator; and (C ₎ a solvent; wherein the precursor resin (A) comprises the following general formula (1): [Chemical 4] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [Chemistry 5] [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): [Chemistry 6] [4] A negative photosensitive resin composition as described in any one of items 1 to 3, wherein X ₂ and Y ₂ are divalent organic groups and n is a positive integer, wherein the molecular weight ratio of the component represented by the general formula (2) in the above-mentioned propellant resin (A) is 1% or more and less than 30% relative to the repeating units of the propellant resin. [5] A negative photosensitive resin composition as described in any one of items 1 to 3, wherein X ₂ is a divalent organic group having a structure represented by the following general formula (4): [Chemical 7] {wherein, R _x is independently an alkyl group or CF ₃ , and a is an integer from 0 to 4}. [5] A negative photosensitive resin composition as described in any one of items 1 to 4, wherein the above-mentioned X ₂ is a divalent organic group that does not have a structure represented by -NH-CO-, and the above-mentioned X ₂ is a divalent organic group that does not have a nitrogen-containing heterocyclic structure. [6] A negative photosensitive resin composition as described in any one of items 1 to 5, wherein the above-mentioned X ₁ is at least one selected from the group consisting of the following general formulas (5) to (8): [Chemical 8] [7] The negative photosensitive resin composition according to any one of items 1 to 6, wherein _Y1 and _Y2 are at least one selected from the group consisting of the following general formulas (9) to (12): {wherein, R _y each independently represents a monovalent organic group having 1 to 10 carbon atoms, b each independently represents an integer from 0 to 4, A represents a methylene group, an oxygen atom, or a sulfur atom, B each independently represents an oxygen atom or a sulfur atom, and C is selected from the following formula: [Chemical 10] [8] The negative photosensitive resin composition according to any one of items 1 to 7, wherein X ₂ is at least one selected from the group consisting of the following general formulas (13) to (15): [Chemical 11] {wherein, R _z is independently a monovalent organic group having 1 to 10 carbon atoms, c is independently an integer from 0 to 4, and D is a methylene group, a carbonyl group, or an oxygen atom}. [9] A negative photosensitive resin composition as described in any one of items 1 to 8, wherein the precursor resin (A) is a random copolymer of repeating units of the general formula (1) and repeating units of the general formula (3). [10] A negative photosensitive resin composition as described in any one of items 1 to 9, wherein the photopolymerization initiator (B) has a structure represented by the following general formula (16): [Chemistry 12] {wherein, R ₆ , R ₇ and R ₈ are monovalent organic groups, and R ₆ and R ₇ may be linked to each other to form a ring structure}. [11] A negative photosensitive resin composition as described in any one of items 1 to 10, wherein the photopolymerization initiator (B) comprises a compound selected from the following general formula (17): [Chemical 13] (wherein, _Ra , _Rc , and _Rd are monovalent organic groups having 1 to 10 carbon atoms, _Rb is a monovalent organic group having 1 to 20 carbon atoms, and a is an integer from 0 to 2, and _Re is a monovalent organic group having 1 to 4 carbon atoms, and a ring may be formed by _Re ), the following general formula (18): [Chemical 14] (wherein, _Rf is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, _Rg is a monovalent organic group having 1 to 20 carbon atoms, and _Rh is an organic group having 1 to 10 carbon atoms), and the following general formula (19): [Chemical 15] (wherein R _i and R _j are monovalent organic groups having 1 to 10 carbon atoms). [12] A negative photosensitive resin composition as described in any one of items 1 to 11, further comprising (D) a polymerizable monomer. [13] A negative photosensitive resin composition as described in any one of items 1 to 12, further comprising (E) a plasticizer. [14] A negative photosensitive resin composition comprising: (A) a polyimide precursor resin having a thermal weight loss rate of less than 25% when maintained at 230°C for 2 hours; (B) a photopolymerization initiator; and (C) a solvent. [15] The negative photosensitive resin composition as described in item 14, wherein the precursor resin (A) comprises repeating units of the following general formula (1): [Chemical 16] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [Chemical 17] [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10], at least one of R ₁ and R ₂ is a group represented by the above general formula (2). [16] A negative photosensitive resin composition as described in item 14 or 15, wherein the above polyimide precursor resin (A) is a polyamide-polyimide precursor resin. [17] A method for producing a polyamide-imide, comprising the step of hardening the negative photosensitive resin composition as described in any one of items 1 to 16 to form a polyamide-imide. [18] A method for producing a hardened relief pattern, comprising the following steps: (1) coating a negative photosensitive resin composition as described in any one of items 1 to 16 on a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer; (3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) heating the relief pattern to form a hardened relief pattern. [19] A polyamide-imide cured product, comprising the following general formula (20): [Chemical 18] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, and m is a positive integer}, and the following general formula (3): [Chemical 19] The repeating units of the formula (3) are {wherein X ₂ and Y ₂ are divalent organic groups, and n is a positive integer}, and the molar fraction of the repeating units of the general formula (3) is greater than 25% and less than 100%. [20] A method for manufacturing a polyamide-imide cured product, comprising the following steps: coating a photosensitive resin composition on a substrate to form a photosensitive resin layer on the substrate; drying the obtained photosensitive resin layer; exposing the dried photosensitive resin layer; developing the exposed photosensitive resin layer; and heating the developed photosensitive resin layer to form the polyamide-imide cured product as described in item 19. [21] A semiconductor device having the polyamide-imide cured product as described in item 19 as an insulating layer disposed around wiring. [Effects of the Invention]

The present invention provides a negative photosensitive resin composition that exhibits high resolution, minimal film thickness variation during thermal curing (i.e., a high residual film rate after thermal curing), and a suitable development time even for thin film coating. Furthermore, the present invention provides a method for producing a cured relief pattern, a method for producing polyimide, a cured polyamide-imide product, a method for producing a cured polyamide-imide product, and a semiconductor device using the negative photosensitive resin composition.

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 main purpose. Throughout this specification, when multiple structures of moieties represented by the same symbol in a general formula exist in a molecule, they may be the same or different. In this specification, "(meth)acrylic acid" refers to both "methacrylic acid" and "acrylic acid."

Negative Photosensitive Resin Composition The negative photosensitive resin composition of this embodiment comprises: (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent. (A) The precursor resin comprises the following general formula (1): [Chemical 20] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [Chemical 21] [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): [Chemical 22] A polyamide-imide precursor resin having repeating units of {wherein _X2 and _Y2 are divalent organic groups and n is a positive integer}. Here, the molar fraction of the repeating units of general formula (3) in the precursor resin (A) of the negative photosensitive resin composition is 25% or more and less than 100%. With the above-described composition, a negative photosensitive resin composition can be provided that has high resolution, minimal film thickness variation during thermal curing, and a suitable developing time even during thin film coating.

Another aspect of the negative photosensitive resin composition of this embodiment comprises: (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent; (A) the precursor resin comprises the following general formula (1): [Chemical 23] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [Chemical 24] [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): [Chemical 25] A polyamide-imide precursor resin having repeating units of {wherein _X2 and _Y2 are divalent organic groups, and n is a positive integer}. In the precursor resin (A), the molecular weight ratio of the component represented by general formula (2) relative to the repeating units of the precursor resin is 1% or more and less than 30%. With the above composition, a negative photosensitive resin composition can be provided that has high resolution, minimal film thickness variation during thermal curing, and an appropriate developing time even during thin film coating.

Another aspect of the negative photosensitive resin composition of this embodiment is a negative photosensitive resin composition comprising: (A) a polyimide precursor resin having a thermal weight loss rate of less than 25% when maintained at 230°C for 2 hours; (B) a photopolymerization initiator; and (C) a solvent. This composition provides a negative photosensitive resin composition having high resolution, minimal film thickness variation during thermal curing, and a suitable developing time even for thin film coating.

In this specification, "organic group" means a alkyl group containing carbon and hydrogen, and its derivatives. The derivatives may contain atoms other than carbon and hydrogen (e.g., nitrogen, oxygen, sulfur, silicon).

From the perspective of achieving high sensitivity and high resolution, the negative photosensitive resin composition preferably contains 0.1 to 20 parts by weight of (B) a photopolymerization initiator based on 100 parts by weight of (A) a polyamide-imide precursor.

(A) Polyamide-Imide Precursor (A) The polyamide-imide precursor is a component represented by formulas (1) and (3) above and contained in the negative photosensitive resin composition. (A) The polyamide-imide precursor is converted into a polyamide-imide by a cyclization treatment using heat.

Based on the total molar number of _R1 and _R2 , the ratio of hydrogen atoms in _R1 and _R2 in formula (1) may be 0% or more, preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less.

It is preferred that at least one of _R1 and _R2 in formula (1) is a monovalent organic group represented by general formula (2), and it is also preferred that _R1 and _R2 are monovalent organic groups represented by general formula (2). Based on the total molar number of _R1 and _R2 , the ratio of _R1 and _R2 in formula (1) being monovalent organic groups represented by the above formula (2) may be 100% or less, preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. From the viewpoint of photosensitivity and storage stability, it is preferred that the ratio of hydrogen atoms and the ratio of organic groups in formula (2) be within the above ranges.

m in formula (1) and n in formula (3) may be integers of 1 to 150. From the viewpoint of the photosensitivity of the negative photosensitive resin composition, they are preferably integers of 1 to 100, and more preferably integers of 1 to 70.

In the polyamide-imide precursor (A), the molar fraction of the repeating unit of formula (3) is preferably 25% to 75%, more preferably 50% to 75%. Specifically, the molar ratio (X1: _X2 ) of the component _X1 in the repeating unit of formula (1) to the component _X2 in the repeating unit of formula ( ₃ ) is preferably 2.5:7.5 to 7.5:2.5, more preferably 2.5:7.5 to 5.0:5.0. By setting the molar fraction and/or molar ratio within the above range, a film having a small thickness variation during thermal curing and high flatness can be easily obtained. Regarding resolution, by keeping the molar fraction within the above range, the hydrogen bonds derived from the amide structure promote packing between the polymers, reducing solubility in the developer. This suppresses film swelling during development, making it easier to achieve high resolution. Furthermore, even when coating in thin films, it is easier to maintain an appropriate development time. By keeping the repeating units of the structural units of formula (3) below 75% relative to the overall polymer, the crosslinking density during exposure can be maintained, making it easier to obtain a good pattern.

In the polyamide-imide precursor (A), the molecular weight ratio of the component represented by formula (2) (side chain component) relative to the molecular weight of the repeating unit of the precursor resin is preferably 5% or more and less than 25%, and more preferably 9% or more and less than 23%. By keeping the ratio of the side chain component within the above range, good resolution performance is easily obtained, and the volatility of the side chain during thermal curing is suppressed, thereby easily reducing the change in film thickness associated with curing. Furthermore, the molecular weight of the repeating unit of the copolymer can be calculated by multiplying the molecular weight of each repeating unit by its content ratio (mass ratio) and taking the sum of these numbers.

(A) The (poly)amide portion of a polyamide-imide precursor readily forms strong hydrogen bonds between polymers. This results in a tendency for the density of the resulting coating to be higher than that of a polyimide precursor. Consequently, even in systems with equivalent volatility during the thermal curing step, the variation in film density and film thickness before and after curing tends to be smaller than with a polyimide precursor.

In the polyamide-imide precursor (A), the arrangement of the repeating units of the above formulae (1) and (3) is preferably random from the viewpoint of solvent compatibility. That is, the polyamide-imide precursor (A) is preferably a random copolymer comprising the repeating units of the above formulae (1) and (3). However, the polyamide-imide precursor (A) may also be a block copolymer comprising the repeating units of the above formulae (1) and (3).

In 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 the _-COOR1 group and the _-COOR2 group are adjacent to the -CONH- group. Examples of the tetravalent organic group represented by _X1 include organic groups having 6 to 40 carbon atoms containing an aromatic ring, such as a group having a structure selected from the group consisting of the following general formula (I): [Chemical 26] {wherein, R _<6> each independently represents at least one member selected from the group consisting of a hydrogen atom, a fluorine atom, a monovalent alkyl group having 1 to 10 carbon atoms, and a monovalent fluorine-containing alkyl group having 1 to 10 carbon atoms, l each independently represents an integer selected from 0 to 2, m each independently represents an integer selected from 0 to 3, and n each independently represents an integer selected from 0 to 4}. The structure of X _<1> may be one of the above or a combination of two or more. From the perspective of achieving both heat resistance and photosensitivity, the X _<1> group having the structure represented by formula (I) above is particularly preferred.

As the _X1 group, from the viewpoint of mechanical properties, copper adhesion, and chemical resistance, among the structures represented by the above formula (I), the structures represented by the following general formulas are particularly preferred: [Chemical 27] {wherein, R ₆ , 1 and m are the same as R ₆ , 1 and m in the above formula (I)}.

More specifically, from the viewpoints of mechanical properties, copper adhesion, and chemical resistance, _X1 is preferably at least one selected from the group consisting of the following general formulas (5) to (8):

In the above formula (3), the divalent organic group represented by X ₂ can be exemplified by the structures represented by the following general formulas (II) and (II-1): [Chemical 29] [Chemistry 30] {wherein, R _<6> is independently at least one selected from the group consisting of a hydrogen atom, a fluorine atom, a monovalent alkyl group having 1 to 10 carbon atoms, and a monovalent fluorine-containing alkyl group having 1 to 10 carbon atoms; n is independently an integer selected from 0 to 4; and p is an integer selected from 1 to 20}.

_X2 preferably does not contain -NH-CO- bonds, and more preferably does not contain -NH-COO- or -NH-CO-NH-. Urethane and urea bonds have low thermal decomposition temperatures. Therefore, the absence of these bonds can easily prevent their decomposition and volatility during the thermal curing step, which in turn increases the film thickness variation. "Does not contain -NH-CO- bonds" includes conditions below the detection limit when using known analytical methods.

As X ₂ , among the structures represented by the above formula (II) and formula (II-1), an aromatic group having 6 to 40 carbon atoms is preferred from the viewpoint of heat resistance and chemical resistance. As X ₂ , from the viewpoint of heat resistance, chemical resistance, and resolution, at least one selected from the group consisting of the following general formulae (13) to (15) is particularly preferred: [Chemical 31] {wherein, R _z each independently represents a monovalent organic group having 1 to 10 carbon atoms, c each independently represents an integer from 0 to 4, and D represents a methylene group, a carbonyl group, or an oxygen atom}.

For example, from the same viewpoint as above, X ₂ is preferably a divalent organic group having a structure represented by the following general formula (4): [Chemical 32] {wherein, R _x is independently an alkyl group or CF ₃ , and a is an integer from 0 to 4}.

More specifically, from the viewpoints of heat resistance, chemical resistance, and resolution, _X2 is preferably a divalent group represented by the following general formula: {wherein, R _x , a, and A are the same as R _z , c, and D in the above formulae (13) to (15)}.

From the perspective of achieving both heat resistance and photosensitivity, the divalent organic group represented by Y ₁ in formula (1) and Y ₂ in formula (3) is preferably an aromatic group having 6 to 40 carbon atoms, for example, the structure represented by formula (II).

_Y1 and _Y2 may be the same or different, and may each be a combination of two or more of the above structures. From the perspective of both heat resistance and _{photosensitivity, Y1 and Y2} having the structure represented by formula (II) _are particularly preferred.

From the viewpoint of heat resistance, chemical resistance, and resolution, _Y1 and _Y2 are preferably at least one selected from the group consisting of the following general formulae: (9) to (12): {wherein, R _y each independently represents a monovalent organic group having 1 to 10 carbon atoms, b each independently represents an integer from 0 to 4, A represents a methylene group, an oxygen atom, or a sulfur atom, B each independently represents an oxygen atom or a sulfur atom, and C is selected from the following formula: [Chemical 35] At least one of the groups formed.

More specifically, from the viewpoints of heat resistance, chemical resistance, and resolution, _Y1 and _Y2 are more preferably divalent groups represented by the following general formula: {wherein, R ₆ and n are the same as R _z and b in the above formulae (9) to (12)}.

More specifically, from the viewpoints of mechanical properties, copper adhesion, and chemical resistance, and from the viewpoints of heat resistance, chemical resistance, and resolution, _Y1 and _Y2 are preferably divalent groups represented by the following general formula: {wherein, R ₇ is a hydrogen atom or a monovalent alkyl group having 1 to 5 carbon atoms, and R ₈ is at least one member selected from the group consisting of a hydrogen atom, a fluorine atom, a monovalent alkyl group having 1 to 5 carbon atoms, and a monovalent fluorine-containing alkyl group having 1 to 5 carbon atoms}.

(A) Preparation Method of Polyamide-Imide Progenitor Resin The polyamide-imide progenitor resin can be obtained as follows: First, the tetracarboxylic dianhydride containing the tetravalent organic group _X1 , a photopolymerizable unsaturated double bond alcohol, and any other alcohol (e.g., an alcohol without an unsaturated double bond) are reacted to prepare a partially esterified tetracarboxylic acid (hereinafter also referred to as "acid/ester"). Photopolymerizable unsaturated double-bond alcohols are used in the above reaction, thereby introducing photosensitive groups (e.g., ethylenic double-bond groups) into the side chains of the resulting acid/ester, and further into the side chains of the resulting polyamide-imide precursor resin.

Thereafter, the partially esterified tetracarboxylic acid, the dicarboxylic acid containing the divalent organic group X ₂ , and the diamine containing the divalent organic group Y ₁ are subjected to amide polycondensation.

(Preparation of Acid/Ester) Tetracarboxylic dianhydrides containing a tetravalent organic group _X1 suitable for preparing polyamide-imide precursor resins are represented by tetracarboxylic dianhydrides having the structure represented by the above formula (I), for example: pyromellitic dianhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, diphenylsulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4 ,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane, etc., preferably pyromellitic dianhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride. These may be used alone or in combination of two or more.

Examples of photopolymerizable unsaturated divalent alcohols suitable for preparing polyamide-imide precursor resins include 2-(meth)acryloyloxyethyl alcohol, 1-(meth)acryloyloxy-3-propyl alcohol, 2-(meth)acrylamidoethyl alcohol, hydroxymethyl vinyl ketone, 2-hydroxyethyl ketone, 2-hydroxyethyl (meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, 2-hydroxy-3-tert-butoxypropyl (meth)acrylate, and 2-hydroxy-3-cyclohexyloxypropyl (meth)acrylate.

Other alcohols (e.g., alcohols without unsaturated double bonds) may also be mixed with the above-mentioned photopolymerizable alcohols having unsaturated double bonds. Examples of other alcohols include 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, and benzyl alcohol.

As the polyamide-imide precursor resin, a non-photosensitive polyamide-imide precursor resin prepared solely from the aforementioned alcohols without unsaturated double bonds can also be mixed with a photosensitive polyamide-imide precursor resin. From the perspective of resolution, the non-photosensitive polyamide-imide precursor resin is preferably present in an amount of 200 parts by mass or less per 100 parts by mass of the photosensitive polyamide-imide precursor.

Tetracarboxylic dianhydride and an alcohol are stirred, dissolved, and mixed in a solvent such as the following in the presence of an alkaline catalyst such as pyridine to induce an esterification reaction of the anhydride to obtain the desired acid/ester. The stirring, dissolving, and mixing are preferably carried out at a temperature of 20-50°C for 4-24 hours.

(Preparation of Polyamide-Imide Procurer Resin) A dicarboxylic acid containing a divalent organic group x ₂ can be added to the above-mentioned acid/ester compound (typically, in the form of a solution in the following solvent). A suitable dehydration condensation agent, such as dicyclohexylcarbodiimide, 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1,1-carbonyldioxy-1,2,3-benzotriazole, or N,N'-disuccinimide carbonate, can be added and mixed under ice-cooling to convert the acid/ester compound and the dicarboxylic acid into a polyacid anhydride. A diamine containing divalent organic groups _Y and _Y, separately dissolved or dispersed in a solvent, can be added dropwise to the obtained polyacid anhydride to undergo amide condensation to obtain a polyamide-imide proto-driver resin. Alternatively, the acid/ester and dicarboxylic acid can be acylated with sulfinyl chloride or the like, followed by a reaction with a diamine compound in the presence of a base such as pyridine to obtain a polyamide-imide proto-driver resin.

Examples of dicarboxylic acids containing a divalent organic group _X2 include dicarboxylic acids having the structure represented by the general formula (II). Examples thereof include 4,4'-biphenyldicarboxylic acid, terephthalic acid, azelaic acid, isophthalic acid, 4,4'-dicarboxydiphenyl ether, hexadecanedioic acid, sebacic acid, glutaric acid, 1,9-nonanedicarboxylic acid, adipic acid, tetradecanedioic acid, 1,3-adamantanedicarboxylic acid, phthalic acid, benzophenone-4,4'-dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, bicyclo[2.2.2]octane-1,4-dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclohexane-1,1-dicarboxylic acid, biphenyldicarboxylic acid, succinic acid, and mixtures thereof.

Examples of the diamines containing divalent organic groups Y ₁ and Y ₂ include diamines having a structure represented by the general formula (II), such as p-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenylsulfone, 4 ,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]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-dimethylbenzene Aniline sulfonate and 9,9-bis(4-aminophenyl)fluorene, as well as compounds in which a portion of the hydrogen atoms on the benzene rings are substituted with methyl, ethyl, hydroxymethyl, hydroxyethyl, halogen, etc., such as 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, and mixtures thereof.

After the amide polycondensation reaction is completed, hygroscopic byproducts of the dehydrated condensation agent present in the reaction solution are filtered and separated as needed. Subsequently, a poor solvent such as water, aliphatic lower alcohols, or a mixture thereof is added to the resulting polymer components to precipitate them. The polymer is then purified by repeated redissolution and reprecipitation, followed by vacuum drying to isolate the target polyamide-imide precursor resin. 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.

The molecular weight of the polyamide-imide precursor resin, as measured by gel permeation chromatography (PCC) as a polystyrene-equivalent weight-average molecular weight, is preferably 8,000 to 150,000, more preferably 9,000 to 50,000. A weight-average molecular weight of 8,000 or greater provides excellent mechanical properties, while a weight-average molecular weight of 150,000 or less provides good dispersibility in the developer and good relief pattern resolution. Preferred developing solvents for gel permeation chromatography are tetrahydrofuran and N-methyl-2-pyrrolidone. The weight-average molecular weight is determined based on a calibration curve prepared using standard monodisperse polystyrene. As the standard monodisperse polystyrene, preferably selected is the organic solvent-based standard sample STANDARD SM-105 manufactured by Showa Denko Co., Ltd.

(B) Photopolymerization Initiator: As the photopolymerization initiator, preferably a photo-free radical polymerization initiator, preferably exemplified are: benzophenone derivatives such as benzophenone, methyl o-benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and fluorenone; acetophenone derivatives such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, and 1-hydroxycyclohexylphenyl ketone; 9-sulfuron , 2-methyl 9-oxosulfuronium , 2-isopropyl 9-oxosulfonium , diethyl 9-oxosulfonium 9-oxosulfur Derivatives; Benzyl derivatives such as benzoyl, benzoyl dimethyl ketal, and benzoyl-β-methoxyethyl acetal; Benzoin derivatives such as benzoin and benzoin methyl ether; Oxime such as 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-(o-benzyl)oxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, and 1-phenyl-3-ethoxypropanetrione-2-(o-benzyl)oxime; N-arylglycine acids such as N-phenylglycine; peroxides such as benzoyl peroxide; aromatic biimidazoles and titaniumocenes; photoacid generators such as α-(n-octylsulfonyloxyimino)-4-methoxybenzyl cyanide. Among the above photopolymerization initiators, oximes are particularly preferred in terms of sensitivity.

From the viewpoint of photosensitivity, the oxime-based photopolymerization initiator preferably has a structure (oxime ester structure) represented by the following general formula (16): [Chemical 38] {wherein, R ₆ , R ₇ and R ₈ are monovalent organic groups, and R ₆ and R ₇ may be linked to each other to form a ring structure}.

Among the compounds having the oxime ester structure of the above formula (16), from the viewpoint of photosensitivity, the oxime photopolymerization initiator is more preferably selected from the following general formulas (17), (18) and (19): (wherein, _Ra , _Rc and _Rd are monovalent organic groups having 1 to 10 carbon atoms, _Rb is a monovalent organic group having 1 to 20 carbon atoms, and a is an integer from 0 to 2, and _Re is a monovalent organic group having 1 to 4 carbon atoms, and a ring may be formed by _Re ), the following general formula (18): [Chemical 40] (wherein, _Rf is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, _Rg is a monovalent organic group having 1 to 20 carbon atoms, and _Rh is an organic group having 1 to 10 carbon atoms), and the following general formula (19): [Chemical 41] (wherein, R _i and R _j are monovalent organic groups having 1 to 10 carbon atoms) at least one member selected from the group consisting of

In the polyamide-imide proto-driver resin composition, the amount of the photopolymerization initiator (B) is preferably 10 parts by mass or less, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the polyamide-imide proto-driver resin.

(C) Solvent Examples of solvents include amides, sulfides, ureas, ketones, esters, lactones, ethers, hydrocarbon halides, hydrocarbons, and alcohols.

Examples of the solvent include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, ethyl lactate, methyl lactate, butyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, ethyl acetylacetate, succinate, dimethyl malonate, propylene glycol monomethyl ether, benzyl alcohol, phenylene glycol, tetrahydrofuran methyl alcohol, ε-caprolactone, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, morpholine, dimethyl malonate, dichloromethane, 3-methoxy-N,N-dimethylpropionamide, 1,2-dichloroethane, 1,4-dichlorobutane, chlorobenzene, o-dichlorobenzene, anisole, hexane, heptane, benzene, toluene, xylene, 1,3,5-trimethylbenzene. Among them, from the viewpoints of resin solubility, resin composition stability, and substrate adhesion, preferred are N-methyl-2-pyrrolidone, dimethyl sulfoxide, tetramethylurea, butyl acetate, ethyl lactate, γ-butyrolactone, dimethyl succinate, ε-caprolactone, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, diethylene glycol dimethyl ether, 3-methoxy-N,N-dimethylpropionamide, benzyl alcohol, dimethyl malonate, phenylene glycol, ethyl acetylacetate, and tetrahydrofuryl alcohol.

Among these solvents, γ-butyrolactone, dimethyl sulfoxide, tetrahydrofuranyl alcohol, ethyl acetylacetate, dimethyl succinate, dimethyl malonate, and ε-caprolactone are particularly preferred. The inclusion of these organic solvents can reduce the variation in film thickness during thermal curing. While the reason for the reduction in film thickness variation during thermal curing by the inclusion of these organic solvents is unclear, the inventors speculate as follows. Previously, amide-based solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide have been used as organic solvents for dissolving photosensitive resin compositions containing polyimide precursors. While these solvents have a very high ability to dissolve polyimide precursors, they tend to remain in the pre-baked film in large quantities due to the strong hydrogen bonds formed between the solvent's amide structure and the polymer's amide structure, particularly the amide structure in formula (3). Consequently, they evaporate during thermal curing, causing a significant change in film thickness. On the other hand, by including the aforementioned solvents, such as γ-butyrolactone, the amount of solvent in the pre-baked film can be reduced, resulting in a film with less change in film thickness during thermal curing.

In the polyamide-imide protodiene resin composition, the amount of the solvent used 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 polyamide-imide protodiene resin.

(D) Photopolymerizable Compound (Polymerizable Monomer) The polyamide-imide precursor resin composition preferably further comprises a photopolymerizable compound. A photopolymerizable compound is a monomer having photopolymerizable unsaturated bonds that can be crosslinked with the polyamide-imide precursor resin upon exposure. Preferred monomers are (meth)acrylic compounds that undergo free radical polymerization with a photopolymerization initiator. Examples of photopolymerizable compounds include diethylene glycol di(meth)acrylate and tetraethylene glycol di(meth)acrylate. That is, examples of photopolymerizable compounds include mono- or di-(meth)acrylates of ethylene glycol or polyethylene glycol, mono- or di-(meth)acrylates of propylene glycol or polypropylene glycol, mono-, di- or tri-(meth)acrylates of glycerol, cyclohexane di-(meth)acrylate, 1,4-butanediol di-(meth)acrylate, 1,6-hexanediol di-(meth)acrylate, neopentyl glycol di-(meth)acrylate, mono- or di-(meth)acrylates of bisphenol A, benzene tri-(meth)acrylate, isobutyl (meth)acrylate, (meth)acrylamide and its derivatives, trihydroxymethylpropane tri-(meth)acrylate, di- or tri-(meth)acrylates of glycerol, di-, tri- or tetra-(meth)acrylates of pentaerythritol, and ethylene oxide or propylene oxide adducts of these compounds.

When the polyamide-imide precursor resin composition contains the aforementioned monomer having a photopolymerizable unsaturated bond, the amount of the monomer having a photopolymerizable unsaturated bond is preferably 1 to 80 parts by weight per 100 parts by weight of the polyamide-imide precursor resin. An amount of 1 part by weight or greater achieves good sensitivity during exposure, while an amount of 80 parts by weight or less results in excellent in-plane uniformity of the coating. Furthermore, from the perspective of suppressing film thickness variation during thermal curing, the amount of the monomer having a photopolymerizable unsaturated bond is more preferably 20 to 80 parts by weight per 100 parts by weight of the polyamide-imide precursor resin.

Among these photopolymerizable compounds, diethylene glycol di(meth)acrylate is preferred from the perspective of resolution performance. From the perspective of suppressing curing shrinkage and chemical resistance, compounds having multiple (e.g., three or more) free radical polymerizable functional groups are preferred. Free radical polymerizable compounds may be used alone or in combination. The number of free radical polymerizable functional groups in a compound having multiple free radical polymerizable functional groups may be, for example, three or more and six or less.

(E) Plasticizer A plasticizer is a compound that improves the fluidity of the polyamide-imide precursor resin (A) during heat curing of the relief pattern formed using the photosensitive resin composition of this embodiment. The inclusion of a plasticizer helps to minimize film thickness variation during curing.

Examples of the plasticizer include polycarboxylic acid ester plasticizers, sulfonamide plasticizers, phosphate plasticizers, polyester plasticizers, and polyalkylene glycol plasticizers.

Specific examples of polycarboxylic acid ester plasticizers include methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, pentyl benzoate, heptyl benzoate, n-octyl benzoate, nonyl benzoate, isononyl benzoate, isodecyl benzoate, 2-ethylhexyl benzoate, isodecyl benzoate, butylbenzyl benzoate, cyclopropyl benzoate, cyclobutyl benzoate, cyclopentyl benzoate, cyclohexyl benzoate, cycloheptyl benzoate, allyl benzoate, butylbenzyl benzoate, and phenyl benzoate. Benzoate esters; dimethyl phthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dipentyl phthalate, diheptyl phthalate, dioctyl phthalate, dinonyl phthalate, diisononyl phthalate, diisodecyl phthalate, bis(2-ethylhexyl) phthalate, diisodecyl phthalate, butylbenzyl phthalate, dicyclopropyl phthalate, dicyclobutyl phthalate, dicyclopentyl phthalate, dicyclohexyl phthalate Phthalate esters such as dicyclohexyl formate, dicycloheptyl phthalate, diallyl phthalate, dibutylbenzyl phthalate, and diphenyl phthalate; trimethyl trimellitate, triethyl trimellitate, tripropyl trimellitate, tributyl trimellitate, tripentyl trimellitate, triheptyl trimellitate, tri-n-octyl trimellitate, trinonyl trimellitate, triisononyl trimellitate, triisodecyl trimellitate, tri(2-ethylhexyl) trimellitate, and trimellitate. Trimellitic acid esters such as triisodecyl formate, tributylbenzyl trimellitate, tricyclopropyl trimellitate, tricyclobutyl trimellitate, tricyclopentyl trimellitate, tricyclohexyl trimellitate, tricycloheptyl trimellitate, triallyl trimellitate, tributylbenzyl trimellitate, and triphenyl trimellitate; dimethyl adipate, diethyl adipate, dipropyl adipate, dibutyl adipate, dipentyl adipate, diheptyl adipate, dioctyl adipate, dinonyl adipate, and diisobutyl adipate Adipates such as nonyl adipate, diisodecyl adipate, di(2-ethylhexyl) adipate, diisodecyl adipate, butylbenzyl adipate, dicyclopropyl adipate, dicyclobutyl adipate, dicyclopentyl adipate, dicyclohexyl adipate, dicycloheptyl adipate, diallyl adipate, dibutylbenzyl adipate, and diphenyl adipate; adipates such as trimethyl trimellitate, triethyl trimellitate, tripropyl trimellitate, tributyl trimellitate, tripentyl trimellitate, triheptyl trimellitate, and trimellitate; Triphthalate esters such as tri-n-octyl trimellitate, tri-nonyl trimellitate, tri-isononyl trimellitate, tri-isodecyl trimellitate, tri-(2-ethylhexyl) trimellitate, tri-isodecyl trimellitate, tributylbenzyl trimellitate, tricyclopropyl trimellitate, tricyclobutyl trimellitate, tricyclopentyl trimellitate, tricyclohexyl trimellitate, tricycloheptyl trimellitate, triallyl trimellitate, tributylbenzyl trimellitate, and triphenyl trimellitate; dimethyl sebacate , sebacic acid esters such as diethyl sebacate, dipropyl sebacate, dibutyl sebacate, dipentyl sebacate, diheptyl sebacate, di-n-octyl sebacate, dinonyl sebacate, diisononyl sebacate, diisodecyl sebacate, bis(2-ethylhexyl) sebacate, diisodecyl sebacate, butylbenzyl sebacate, dicyclopropyl sebacate, dicyclobutyl sebacate, dicyclopentyl sebacate, dicyclohexyl sebacate, dicycloheptyl sebacate, diallyl sebacate, dibutylbenzyl sebacate, and diphenyl sebacate; Dimethyl succinate, diethyl succinate, dipropyl succinate, dibutyl succinate, dipentyl succinate, diheptyl succinate, di-n-octyl succinate, dinonyl succinate, diisononyl succinate, diisodecyl succinate, bis(2-ethylhexyl) succinate, diisodecyl succinate, butylbenzyl succinate, dicyclopropyl succinate, dicyclobutyl succinate, dicyclopentyl succinate, dicyclohexyl succinate, dicycloheptyl succinate, diallyl succinate, dibutylbenzyl succinate, diphenyl succinate.

Specific examples of sulfonamide plasticizers include aromatic sulfonamide plasticizers, specifically N-butylbenzenesulfonamide, p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfonamide, N-ethyl-p-toluenesulfonamide, N-ethyl-o-toluenesulfonamide, N-n-butylbenzenesulfonamide, and N-cyclohexyl-p-toluenesulfonamide. N-butylbenzenesulfonamide is preferred.

Specific examples of phosphate ester plasticizers include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, triphenyl phosphate, tricresyl phosphate, trixylphenyl phosphate, cresyl diphenyl phosphate, and 2-ethylhexyl diphenyl phosphate.

Specific examples of polyester plasticizers include: Polyesters containing acid components such as adipic acid, terephthalic acid, isophthalic acid, and diphenyl dicarboxylic acid, and glycol components such as propylene glycol, 1,3-butanediol, 1,4-butanediol, ethylene glycol, and diethylene glycol; Polyesters containing hydroxycarboxylic acids such as polycaprolactone. These polyesters may be end-capped with monofunctional carboxylic acids or monofunctional alcohols, or with epoxy compounds, for example.

Specific examples of polyalkylene glycol plasticizers include: Polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, ethylene oxide addition polymers of bisphenols, and propylene oxide addition polymers of bisphenols; Terminal-capped compounds such as the aforementioned terminal epoxy-modified compounds, terminal ester-modified compounds, and terminal ether-modified compounds.

Specific examples of other plasticizers include: Glycerol fatty acid esters such as glyceryl monoacetyl monolaurate, glyceryl diacetyl monolaurate, and glyceryl monoacetyl monostearate; fatty amides such as stearyl amide; aliphatic carboxylic acid esters such as butyl oleate; oxygen-containing acid esters such as methyl acetylic ricinoleate and butyl acetylic ricinoleate; pentaerythritol; and various sorbitols.

Thermal Alkali Generator The polyamide-imide precursor resin composition may contain an alkali generator. An alkali generator is a compound that generates an alkali upon heating. The inclusion of a thermal alkali generator can further promote the imidization of the polyamide-imide precursor resin composition.

Examples of the thermal base generator include amine compounds protected by a tert-butoxycarbonyl group and the thermal base generator disclosed in International Publication No. 2017/038598. However, other known thermal base generators may also be used.

Examples of the amine compound protected by the tert-butoxycarbonyl group include p-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, valerinol, 3-amino- -1,2-Propanediol, 2-amino-1,3-propanediol, tyramine, norephedrine, 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)-1-propanol] [Amino)ethyl]benzyl alcohol, diethanolamine, diisopropanolamine, 3-pyrrolidinol, 2-pyrrolidinylmethanol, 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) Compounds obtained by protecting the amino group of, but not limited to, 1,2-bis(2-aminoethoxy)ethane, 2,2'-oxybis(ethylamine), 1,14-diamino-3,6,9,12-tetraoxatetradecane, 1-aza-15-crown-5, diethylene glycol bis(3-aminopropyl) ether, 1,11-diamino-3,6,9-trioxateundecane, or amino acids and their derivatives.

The amount of the thermal alkali generator added per 100 parts by mass of the polyamide-imide precursor resin (A) is preferably from 0.1 to 30 parts by mass, more preferably from 1 to 20 parts by mass. From the perspective of accelerating imidization, the amount is preferably from 0.1 to 20 parts by mass. From the perspective of the physical properties of the photosensitive resin layer after curing of the polyamide-imide precursor resin composition, the amount is preferably from 20 to 20 parts by mass.

Nitrogen-Containing Heterocyclic Compounds When using a polyamide-imide precursor resin composition to form a cured film on a copper or copper alloy substrate, the polyamide-imide precursor resin composition may optionally contain a nitrogen-containing heterocyclic compound to suppress discoloration on the copper. Examples of nitrogen-containing heterocyclic compounds include azole compounds and purine derivatives.

Examples of the azole compound include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-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)phenyl]-1H-triazole, and the like. [1-Hydroxy]-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 series, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-hydroxy-1H-benzotriazole, 5-hydroxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, 1-methyl-1H-tetrazole.

Among them, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, and 5-amino-1H-tetrazole are preferred. These azole compounds may be used alone or as a mixture of two or more.

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- Aminadenine, 6-amino-8-phenyl-9H-purine, 1-ethyladenine, 6-ethylaminopurine, 1-benzyladenine, N-methylguanine, 7-(2-hydroxyethyl)guanine, N-(3-chlorophenyl)guanine, N-(3-ethylphenyl)guanine, 2-azaadenine, 5-azaadenine, 8-azaadenine, 8-azaguanine, 8-azapurine, 8-azaxanthine, 8-azahypoxanthine, and derivatives thereof.

When the polyamide-imide pro-driver resin composition contains the aforementioned azole compound or purine derivative, the amount thereof is preferably 0.1 to 20 parts by weight relative to 100 parts by weight of the polyamide-imide pro-driver resin (A), and more preferably 0.5 to 5 parts by weight from the perspective of sensitivity. When the amount of the azole compound is 0.1 parts by weight or greater relative to 100 parts by weight of the polyamide-imide pro-driver resin (A), discoloration of the copper or copper alloy surface is suppressed when the polyamide-imide pro-driver resin composition is formed on copper or a copper alloy. On the other hand, when the amount is 20 parts by weight or less, excellent sensitivity is achieved.

(F) Hindered Phenol Compounds To suppress discoloration on the copper surface, the polyamide-imide pro-driver resin composition may optionally contain (F) hindered phenol compounds. Examples of the hindered phenol compound include 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-butylhydroquinone, 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'-thio-bis(3-methyl-6-tert-butylphenol), 4,4'-butylene-bis(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- 4-hydroxyphenyl) propionate], 2,2-thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-phenylpropionamide), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], tris-(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene.

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-trisin-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-triethylmethyl-3-hydroxyl-2,6-dimethylbenzyl]-1,3,5-trisin-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-trisin-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-3-hydroxyl-2,5,6-trimethylbenzyl)-1,3,5-trisin-2,4,6-(1H,3H,5H)-trione ketone, 1,3,5-tris(4-tert-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(2,4,6-(1H,3H,5H)-trione, trione, 1,3,5-tris(4-tert-butyl-3-hydroxy-2-methylbenzyl)-1,3,5-tris(4-tert-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-tris(4-tert-butyl-5-ethyl-3-hydroxy-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 amount of the hindered phenol compound blended is preferably 0.1 to 20 parts by mass per 100 parts by mass of the polyamide-imide proto-driver resin (A), and more preferably 0.5 to 10 parts by mass from the perspective of sensitivity. When the amount of the hindered phenol compound blended is 0.1 parts by mass or greater per 100 parts by mass of the polyamide-imide proto-driver resin (A), discoloration and corrosion of the copper or copper alloy can be prevented, for example, when the polyamide-imide proto-driver resin composition is formed on copper or a copper alloy. On the other hand, when the amount is 20 parts by mass or less, excellent sensitivity is achieved.

Organic Titanium Compounds Polyamide-imide precursor resin compositions may contain an organic titanium compound. This compound allows the formation of a photosensitive resin layer with excellent chemical resistance, even when cured at low temperatures.

Usable organic titanium compounds include organic chemicals bonded to titanium atoms via covalent or ionic bonds. Specific examples of organic titanium compounds are shown in Sections I) to VII) below: I) Titanium chelate compounds: Titanium chelates having two or more alkoxy groups are particularly preferred for achieving stable storage and good patterning of the polyamide-imide protodiene resin composition. Specific examples include titanium bis(triethanolamine)diisopropylate, titanium bis(2,4-pentanedioate)di-n-butanedioate, titanium bis(2,4-pentanedioate)diisopropylate, titanium bis(tetramethylpimelic acid)diisopropylate, and titanium bis(ethylacetoacetic acid)diisopropylate. II) Titanium tetraalkoxy compounds: for example, titanium tetra(n-butanol), titanium tetraethanol, titanium tetra(2-ethylhexanol), titanium tetraisobutanol, titanium tetraisopropanol, titanium tetramethanol, titanium tetramethoxypropanol, titanium tetramethylphenoxide, titanium tetra(n-nonanol), titanium tetra(n-propanol), titanium tetrastearoyl, and titanium tetra[bis{2,2-(allyloxymethyl)butanol}]. III) Titanium cyclopentadienyl trimethoxide compounds: for example, titanium pentamethylcyclopentadienyl trimethanol, 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, etc. IV) Titanium monoalkoxy compounds: for example, titanium tris(dioctylphosphate)isopropylate, titanium tris(dodecylbenzenesulfonate)isopropylate. V) Titanium oxide compounds: for example, titanium bis(glutaric acid)oxide, titanium bis(tetramethylpimelic acid)oxide, and titanium phthalocyanine oxide. VI) Titanium tetraacetylacetonate compounds: for example, titanium tetraacetylacetonate. VII) Titanium ester coupling agent: for example, isopropyl tri(dodecylbenzenesulfonyl) titanium ester. From the perspective of achieving 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) titanocene compounds. Particularly preferred are titanium diisopropyl bis(ethylacetoacetate), titanium tetra(n-butoxide), and bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium.

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

Adhesion Aids To improve the adhesion between the film formed using the polyamide-imide pro-driver resin composition and the substrate, the polyamide-imide pro-driver resin composition may optionally contain an adhesion aid. Examples of the bonding aid include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-butylpropylmethyldimethoxysilane, 3-methacryloyloxypropyldimethoxymethylsilane, 3-methacryloyloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinylpropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl) Silane coupling agents such as terephthalamide, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propylsuccinic anhydride, N-phenylaminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-(trialkoxysilyl)propylsuccinic anhydride, and aluminum-based bonding agents such as tris(ethyl acetylacetate)aluminum and tris(acetylacetonate)aluminum.

Among these bonding agents, silane coupling agents are more preferred in terms of adhesion. When the polyamide-imide proto-driver resin composition contains a bonding agent, the amount of the bonding agent is preferably in the range of 0.5 to 25 parts by weight per 100 parts by weight of the polyamide-imide proto-driver resin (A).

Examples of the silane coupling agent include 3-butylpropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name KBM803, manufactured by Chisso Co., Ltd.: trade name Sila-Ace S810), 3-butylpropyltriethoxysilane (manufactured by Azmax Co., Ltd.: trade name SIM6475.0), 3-butylpropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name LS1375, manufactured by Azmax Co., Ltd.: trade name SIM6474.0), butylmethyltrimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SIM6473.5C), butylmethylmethyldimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SIM6473.0), 3-Alkylpropyldiethoxymethoxysilane, 3-Alkylpropylethoxydimethoxysilane, 3-Alkylpropyltripropoxysilane, 3-Alkylpropyldiethoxypropoxysilane, 3-Alkylpropylethoxydipropoxysilane, 3-Alkylpropyldimethoxypropoxysilane, 3-Alkylpropylmethoxydipropoxysilane, 2-Alkylethyltrimethoxysilane, 2-Alkylethyl Diethoxymethoxysilane, 2-Alkylethylethoxydimethoxysilane, 2-Alkylethyltripropoxysilane, 2-Alkylethyltripropoxysilane, 2-Alkylethylethoxydipropoxysilane, 2-Alkylethyldimethoxypropoxysilane, 2-Alkylethylmethoxydipropoxysilane, 4-Alkylbutyltrimethoxysilane, 4-Alkylbutyltriethoxysilane, 4-Alkylbutyltripropoxysilane.

Examples of silane coupling agents include N-(3-triethoxysilylpropyl)urea (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name LS3610, manufactured by Azmax Co., Ltd.: trade name SIU9055.0), N-(3-trimethoxysilylpropyl)urea (manufactured by 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), m-aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.0), p-aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.1), and aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: trade name SLA0599.2) can be enumerated.

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)-t-butyl carbamate, (3-glycidyloxypropyl)triethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-isopropoxysilane, tetra-n-butoxysilane, tetra-isobutoxysilane, tetra-t-butoxysilane, tetra(methoxyethoxy)-t-butylcarbamate, and tetra-n-butoxysilane. silane), tetrakis(methoxy-n-propoxysilane), tetrakis(ethoxyethoxysilane), tetrakis(methoxyethoxyethoxysilane), bis(trimethoxysilyl)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]tetrakis Thioether, di-tert-butoxydiethoxysilane, di-isobutoxyaluminoxytriethoxysilane, phenylsilanetriol, methylphenylsilanediol, ethylphenylsilanediol, n-propylphenylsilanediol, isopropylphenylsilanediol, n-butyldiphenylsilanediol, isobutylphenylsilanediol, tert-butylphenylsilanediol, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, ethylmethylphenylsilanol, n-propylmethylphenylsilanediol, isopropyl Methylphenylsilanol, 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.

The silane coupling agents listed above can be used alone or in combination. Among the silane coupling agents listed above, preferred from the perspective of storage stability are phenylsilanetriol, trimethoxyphenylsilane, trimethoxy(p-tolyl)silane, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol, and silane coupling agents having a structure represented by the following formula. [Chemistry 42]

When a silane coupling agent is used, the amount thereof is preferably 0.01 to 20 parts by mass relative to 100 parts by mass of the polyamide-imide pro-driver resin (A).

Sensitizers To increase sensitivity, the polyamide-imide precursor resin composition may optionally contain a sensitizer. Examples of 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-dimethylaminobenzylidene Methylaminocinnamylene indanone, p-dimethylaminobenzylidene indanone, 2-(p-dimethylaminophenyl biphenylene)-benzothiazole, 2-(p-dimethylaminophenyl vinylene)benzothiazole, 2-(p-dimethylaminophenyl vinylene) isonaphthothiazole, 1,3-bis(4'-dimethylaminobenzylidene)acetone, 1,3-bis(4'-diethylaminobenzylidene)acetone, 3,3'-carbonyl-bis(7- diethylaminocoumarin), 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-Benzolinylbenzophenone, 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. These can be used alone or in combinations of 2 to 5.

When the polyamide-imide proto-drug resin composition contains a sensitizer for increasing sensitivity, the amount thereof is preferably 0.1 to 25 parts by mass relative to 100 parts by mass of the polyamide-imide proto-drug resin (A).

(G) Polymerization Inhibitors To improve the viscosity and photosensitivity stability of the polyamide-imide proto-resin composition, particularly when stored in a solution containing a solvent, the polyamide-imide proto-resin composition may optionally contain a polymerization inhibitor. Examples of polymerization inhibitors include hydroquinone, N-nitrosodiphenylamine, p-tert-butyl o-catechol, phenanthridine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt.

"Method for Producing a Hardened Relief Pattern" The method for producing a hardened relief pattern of this embodiment comprises: (1) coating the negative photosensitive resin composition of this embodiment on a substrate to form a photosensitive resin layer on the substrate (resin layer forming step); (2) exposing the photosensitive resin layer (exposure step); (3) developing the exposed photosensitive resin layer to form a relief pattern (relief pattern forming step); and (4) heating the relief pattern to form a hardened relief pattern (hardened relief pattern forming step).

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

The coating comprising the photosensitive resin composition can be dried as needed. Examples of drying methods include air drying, heat drying in an oven or on a hot plate, and vacuum drying. Specifically, air drying or heat drying can be performed at 20°C to 150°C for 1 minute to 1 hour. As described above, a photosensitive resin layer can be formed on the substrate.

(2) Exposure Step In this step, an exposure device such as a contact aligner, a mirror projection exposure machine, or a stepper is used to expose the photosensitive resin layer formed above by a UV light source, etc., through a photomask or a reticle having a pattern, or directly. By this exposure, the polymerizable groups of the (A) polyamide-imide precursor contained in the negative photosensitive resin composition are crosslinked by the action of the (B) photopolymerization initiator. By this crosslinking, the exposed portion is made insoluble in the developer described below, thereby forming a relief pattern.

To improve sensitivity, a post-exposure bake (PEB) or pre-development bake, or both, may be performed as needed, using any combination of temperature and time. The baking conditions are preferably 40°C to 120°C and 10 to 240 seconds, but are not limited to these ranges as long as they do not impair the properties of the photosensitive resin composition of this embodiment.

(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. After development, in order to adjust the shape of the relief pattern, a post-development bake based on any combination of temperature and time can be performed as needed.

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

(4) Hardened relief pattern formation step In this step, the relief pattern obtained by the above-mentioned development is subjected to a heat treatment to disperse the photosensitive component and partially imidize the imide precursor of the (A) polyamide-imide precursor, thereby converting it into a hardened relief pattern containing polyamide-imide. As a method for heat treatment, various methods can be selected, such as a method based on a heating 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 150°C to 350°C and for 30 minutes to 5 hours. The temperature of the heat treatment is 150°C to 250°C, preferably 150°C to 230°C, and more preferably 170°C to 230°C. As the atmosphere gas during heat curing, air can be used, or inert gases such as nitrogen and argon can be used.

The negative photosensitive resin composition of this embodiment can be cured to form a polyamide-imide (cured polyamide-imide). The polyamide-imide formed from the photosensitive resin composition of this embodiment comprises the following general formula (20): The following general formula (20): [Chemical 43] {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, and m is a positive integer}, and the following general formula (3): [Chemical 44] The molar fraction of the repeating units of _the general formula (3) in the polyamide-imide is greater than 25% and less than ₁₀₀ %.

Preferred X ₁ , X ₂ , Y ₁ , and Y ₂ in formulas (1) and (3) are also preferred in the polyimide structures represented by the above formulas for the same reasons. In the above formulas, the polyimide structure and the polyamide structure preferably form a random copolymer. The number of repeating units in formulas (20) and (3) is preferably an integer between 2 and 150.

"Method for Producing Cured Polyamide-Imide" The method for producing a cured polyamide-imide according to this embodiment comprises: coating the aforementioned photosensitive resin composition on a substrate to form a photosensitive resin layer on the substrate; drying the resulting photosensitive resin layer; exposing the dried photosensitive resin layer to light; developing the exposed photosensitive resin layer; and heating the developed photosensitive resin layer to form the cured polyamide-imide according to this embodiment. The examples and preferred embodiments listed in the aforementioned "Method for Producing a Hardened Relief Pattern" can also be similarly applied to the method for producing a cured polyamide-imide product.

Semiconductor Device The present invention also provides a semiconductor device having a hardened relief pattern obtained by the above-described method for producing a hardened relief pattern. For example, a semiconductor device can be provided that includes: a substrate serving as a semiconductor element; and a hardened relief pattern of a polyamide-imide formed on the substrate by the above-described method for producing a hardened relief pattern. Furthermore, a method for producing a semiconductor device can be provided that uses a semiconductor element as a substrate and includes the above-described method for producing a hardened relief pattern as a step. Semiconductor devices can be manufactured by using the hardened relief pattern formed using the method for manufacturing a hardened relief pattern of the present invention as a surface protective film, an interlayer insulating film, an insulating film for redistribution wiring, a protective film for flip-chip devices, or a protective film for semiconductor devices with bump structures, and combining this method with conventional semiconductor device manufacturing methods.

The above-mentioned cured polyamide-imide (cured polyamide-imide film) is used, for example, as an insulating layer (also called a "rewiring insulating film" or "interlayer insulating film") in semiconductor devices. This insulating layer is placed around the wiring that electrically connects the semiconductor chip to external terminals in a semiconductor device. The insulating layer may be provided in one, two, or more layers.

Display Device The present invention provides a display device comprising a display element and a cured film disposed on the display element, the cured film being the aforementioned hardened relief pattern. The hardened relief pattern may be laminated directly in contact with the display element or interposed between other layers. Examples of the cured film include surface protective films, insulating films, and planarizing films for TFT (Thin Film Transistor) liquid crystal display elements and color filter elements, protrusions for MVA (Multi-Domain Vertical Alignment) liquid crystal display devices, and spacers for cathodes in organic EL elements.

In addition to being applicable to semiconductor devices such as those described above, the negative photosensitive resin composition of this embodiment is also useful for interlayer insulation in multilayer circuits, cover coatings for flexible copper-clad laminates, solder resists, and liquid crystal alignment films. [Examples]

The present embodiment is described in detail below by way of examples. The physical properties of the polyamide-imide precursor or negative photosensitive resin composition were measured and evaluated according to the following methods.

<Measurement and Evaluation Methods> (1) Weight Average Molecular Weight The weight average molecular weight (Mw) of each resin was measured by gel permeation chromatography (converted to standard polystyrene) under the following conditions. Pump: JASCO PU-980 Detector: JASCO RI-930 Column Oven: JASCO CO-965 40°C Column: Shodex KD-805/KD-804/KD-803 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.

<Derivation of the Shortest Development Time> Each photosensitive resin composition prepared by the following method was spin-coated onto a 6-inch silicon wafer using a spin coater (Model D-SPIN60A, manufactured by SOKUDO Corporation) and dried on a hot plate at 100°C for 240 seconds to form a coating with a thickness of 7.5 μm ± 0.2 μm. The resulting coating was spray-developed with cyclopentanone using a developer (Model D-SPIN636, manufactured by Dainippon Screen Co., Ltd.). The shortest development time was defined as the shortest time required for complete development removal of the coating (the shortest development completion time), and was evaluated according to the following criteria. A: Minimum development time is 10 seconds or longer but less than 20 seconds. B: Minimum development time is 5 seconds or longer but less than 10 seconds. C: Minimum development time is less than 5 seconds.

Fabrication and Evaluation of Relief Patterned Films: A 6-inch wafer (Fujimi Electronics Co., Ltd., thickness 625 ± 25 μm) was sputter-coated with 200 nm of Ti and 400 nm of Cu in sequence using a sputter coating system (Model L-440S-FHL, Canon Aneva Co., Ltd.) to prepare a sputter-coated Cu wafer substrate. A photosensitive resin composition was spin-coated onto the sputter-coated Cu wafer substrate using a spin coater (Model D-SPIN60A, SOKUDO Co., Ltd.) and dried on a hot plate at 100°C for 240 seconds to produce a coating with a thickness of 7.5 μm ± 0.2 μm. The spin-coated film was exposed using a PrismaGHI S/N5503 (Ultratech) projection exposure system equipped with a GH-cut filter and a 5 μm-diameter circular pattern with a test pattern attached. The exposure dose was varied from ³⁰ mJ/ ^cm² to 270 mJ/ ^cm² on a 20 mJ/cm² scale. The coating, formed on a sputter-coated Cu wafer, was then spray-developed using cyclopentanone using a developer (Model D-SPIN636, Dainippon Screen Co., Ltd.) and rinsed with propylene glycol methyl ether acetate to obtain a polyamide pattern. Furthermore, the developing time of the spray developing method was set to 1.4 times the shortest developing time obtained above.

<Evaluation of Maximum Resolution> Based on the above-mentioned change in circular pattern diameter, the minimum value of the mask size of the circular relief pattern obtained is defined as the maximum resolution (μm), and evaluation is performed based on the following criteria. Furthermore, regarding the quality of the circular relief pattern opening, those that meet both criteria (I) and (II) below are considered acceptable. (I) The area of the pattern opening is at least 1/2 of the area of the corresponding pattern mask opening. (II) The pattern cross-section has no flanging, undercuts, bulging, or bridging. A: Maximum resolution is 5 μm or less B: Maximum resolution is greater than 5 μm and less than 6 μm C: Maximum resolution is greater than 6 μm and less than 7 μm D: Maximum resolution is greater than 7 μm

<Residual Film Ratio After Curing> A 6-inch silicon wafer (Fujimi Electronics Co., Ltd., thickness 625 ± 25 μm) was sputter-coated with 200 nm of Ti and 400 nm of Cu in that order using a sputtering apparatus (Model L-440S-FHL, Canon Aneva Co., Ltd.). Subsequently, a photosensitive resin composition prepared as described below was spin-coated onto the wafer using a coating developer (Model D-Spin60A, SOKUDO Co., Ltd.) and pre-baked on a hot plate at 110°C for 180 seconds, resulting in a coating film approximately 7.5 μm thick. The spin-coated film was fully exposed using a Prisma GHI S/N5503 (Ultratech) projection exposure system equipped with a GH-ray cutoff filter, using the exposure dose that yielded the highest resolution in the "Evaluation of Maximum Resolution" section above. The exposed film was then spray-developed using cyclopentanone using a developer (model D-SPIN636, Dainippon Screen Co., Ltd.) and rinsed with propylene glycol methyl ether acetate to obtain a developed film on Cu. The spray development time was set to 1.4 times the shortest development time determined above. The thickness of the developed film was measured and defined as the post-development film thickness.

The developed film was heated at 230°C for 2 hours in a nitrogen atmosphere using a temperature-programmed curing furnace (Model VF-2000, manufactured by Koyo Lindberg) to obtain a hardened relief pattern. The thickness of the resulting cured film was measured and defined as the post-curing film thickness. The post-curing residual film rate was defined according to the following formula and evaluated based on the criteria A to E. Residual film rate after curing = (Film thickness after curing / Film thickness after development) × 100 (%) A: Residual film rate after curing is 90% or higher B: Residual film rate after curing is 88% or higher but less than 90% C: Residual film rate after curing is 86% or higher but less than 88% D: Residual film rate after curing is 84% or higher but less than 86% E: Residual film rate after curing is less than 84%

<Calculation of Thermogravimetric Weight Loss> Thermogravimetric weight loss of each resin was measured under the following conditions using a simultaneous differential thermal analysis and thermogravimetric (TG/DTA) instrument (DTG-60A, Shimadzu Corporation). Measurement atmosphere: Nitrogen Gas flow rate: 50 ml/min Temperature profile: The initial temperature was set at 23°C, and the temperature was increased at a rate of 5°C/min to 230°C, followed by holding at 230°C for 2 hours. The weight loss at 230°C is defined according to the following formula: Weight loss at 230°C = (1 - (sample weight after measurement / sample weight before measurement)) × 100 (%)

<Elongation at Break after Reliability Testing> A photosensitive resin composition prepared as described below was spin-coated onto a 6-inch silicon wafer (Fujimi Electronics Co., Ltd., thickness 625 ± 25 μm) using a coating developer (Model D-Spin60A, manufactured by SOKUDO). This was then pre-baked on a hot plate at 110°C for 180 seconds to form a coating with a thickness of approximately 10.0 μm. The entire surface of the coating was exposed to light using a PrismaGHI (manufactured by Ultratech) at an exposure dose of 1000 mJ/ ^cm² . The exposed film was heated at 230°C for 2 hours in a nitrogen atmosphere using a temperature-programmed curing furnace (Model VF-2000, manufactured by Koyo Lindberg) to obtain a cured film (polyimide film). The cured film was then heated in air at 130°C and 85% RH for 168 hours using a highly accelerated life tester (PC-R8D, manufactured by Hirayama Seisakusho). The heated cured film was then cut into 3 mm wide strips using a wafer dicing machine (Model DAD3350, manufactured by DISCO Corporation) and peeled from the silicon wafer using 46% hydrofluoric acid. This yielded a polyimide tape. The resulting polyimide tapes were conditioned for at least 24 hours at a temperature of 23°C and a humidity of 50%. The elongation at break (%) of the tapes was measured using a tensile testing machine (Model UTM-II-20, manufactured by Orientec) at a speed of 40 mm/min and an initial weight of 0.5 fs. Evaluation was performed based on the following criteria. "A": 60% or more "B": 50% or more and less than 60% "C": 40% or more and less than 50% "D": 30% or more and less than 40% "E": less than 30% Furthermore, the elongation at break (%) of the polyimide tape is calculated by the following formula: Elongation (%) = 100 × (L-L0) / L0 L: The length of the polyimide tape before it breaks in the tensile test L0: The length of the polyimide tape before the test

(A) Examples of Polyamide-Imide Producer Resins <Synthesis Example 1> Synthesis of Polymer A-1 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 5 L separable flask. 67.7 g of 2-hydroxyethyl methacrylate (HEMA) and 200 mL of γ-butyrolactone were added and stirred at room temperature. While stirring, 40.0 g of pyridine was added to obtain a reaction mixture. After the reaction heat dissipated, the mixture was cooled to room temperature and allowed to stand for 16 hours.

Next, 64.6 g of 4,4'-dicarboxydiphenyl ether was added and stirred. Under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Subsequently, a solution of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 2000 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution.

The resulting reaction solution was added to 3 L of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 2 L of γ-butyrolactone to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polyamide-imide protodiene resin A-1. Vacuum drying was continued until the moisture content of the polyamide-imide protodiene resin A-1 reached less than 1.0%. The molecular weight of polyamide-imide protodiol resin A-1 was determined by gel permeation chromatography (based on standard polystyrene) and found to have a weight average molecular weight (Mw) of 25,000.

<Synthesis Example 2> Synthesis of Polymer A-2 38.8 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 5 L separable flask. 33.8 g of 2-hydroxyethyl methacrylate (HEMA) and 200 mL of γ-butyrolactone were added and stirred at room temperature. While stirring, 40.0 g of pyridine was added to obtain a reaction mixture. After the reaction heat dissipated, the mixture was cooled to room temperature and allowed to stand for 16 hours.

Next, 96.8 g of 4,4'-dicarboxydiphenyl ether was added and stirred. Under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Subsequently, a solution of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 2000 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution.

The resulting reaction solution was added to 3 L of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 2 L of γ-butyrolactone to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polyamide-imide proto-driver resin A-2. The molecular weight of the polyamide-imide proto-driver resin A-2 was determined by gel permeation chromatography (standard polystyrene conversion), and the weight average molecular weight (Mw) was 23,000.

<Synthesis Example 3> Synthesis of Polymer A-3 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 88.5 g of 2,2'-dimethylbiphenyl-4,4'-diamine was used in place of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyamide-imide protodiene resin A-3 was obtained. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-3 was 21,000.

<Synthesis Example 4> Synthesis of Polymer A-4 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 73.6 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used in place of 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA). Polyamide-imide protodiene resin A-4 was obtained. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-4 was 22,000.

<Synthesis Example 5> Synthesis of Polymer A-5 A polyamide-imide protodiene resin A-6 was obtained by the same method as described in Synthesis Example 1, except that 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) was used in place of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-5 was 20,000.

<Synthesis Example 6> Synthesis of Polymer A-6 116.3 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 5 L separable flask. 101.5 g of 2-hydroxyethyl methacrylate (HEMA) and 200 mL of γ-butyrolactone were added and stirred at room temperature. 59.3 g of pyridine was added while stirring to obtain a reaction mixture. After the reaction heat dissipated, the mixture was cooled to room temperature and allowed to stand for 16 hours.

Next, 32.3 g of 4,4'-dicarboxydiphenyl ether was added and stirred. Under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Next, a solution of 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 2000 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution.

The resulting reaction solution was added to 3 L of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 2 L of γ-butyrolactone to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polyamide-imide proto-driver resin A-6. The molecular weight of the polyamide-imide proto-driver resin A-6 was determined by gel permeation chromatography (standard polystyrene conversion), and the weight average molecular weight (Mw) was 20,000.

<Synthesis Example 7> Synthesis of Polymer A-7 38.8 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 5 L separable flask. 33.8 g of 2-hydroxyethyl methacrylate (HEMA) and 200 mL of γ-butyrolactone were added and stirred at room temperature. While stirring, 19.8 g of pyridine was added to obtain a reaction mixture. After the reaction heat dissipated, the mixture was cooled to room temperature and allowed to stand for 16 hours.

Next, 96.8 g of 4,4'-dicarboxydiphenyl ether was added and stirred. Under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Next, a solution of 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 2000 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution.

The resulting reaction solution was added to 3 L of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 2 L of γ-butyrolactone to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polyamide-imide proto-drug resin A-7. The molecular weight of the polyamide-imide proto-drug resin A-7 was determined by gel permeation chromatography (standard polystyrene conversion), and the weight average molecular weight (Mw) was 22,000.

<Synthesis Example 8> Synthesis of Polymer A-8 A polyamide-imide protodiene resin A-8 was obtained by the same method as described in Synthesis Example 1, except that 73.6 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used in place of 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA) and 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) was used in place of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-8 was 22,500.

<Synthesis Example 9> Synthesis of Polymer A-9 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 129.4 g of 4,4'-methylenebis(2,6-diethylaniline) was used in place of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyamide-imide protodiene resin A-9 was obtained. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-9 was 24,000.

<Synthesis Example 10> Synthesis of Polymer A-10 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 54.5 g of pyromellitic anhydride (PMDA) was used in place of 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA). Polyamide-imide protodiene resin A-10 was obtained. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-10 was 21,000.

<Synthesis Example 11> Synthesis of Polymer A-11 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 60.6 g of 4,4'-biphenyldicarboxylic acid was used in place of 64.6 g of 4,4'-dicarboxydiphenyl ether and 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) was used in place of 171.1 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyamide-imide protodiene resin A-11 was obtained. The weight average molecular weight (Mw) of polyamide-imide protodiene resin A-11 was 22,000.

<Synthesis Example 12> Synthesis of Polymer A-12 A polyamide-imide protodiene resin A-12 was obtained by the same method as described in Synthesis Example 1, except that 60.6 g of 4,4'-biphenyl dicarboxylic acid was used in place of 64.6 g of 4,4'-dicarboxydiphenyl ether. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-12 was 20,500.

<Synthesis Example 13> Synthesis of Polymer A-13 A reaction was conducted in the same manner as described in Synthesis Example 1, except that 67.6 g of benzophenone-4,4'-dicarboxylic acid was used in place of 64.6 g of 4,4'-dicarboxydiphenyl ether. Polyamide-imide protodimer resin A-13 was obtained. The weight-average molecular weight (Mw) of polyamide-imide protodimer resin A-13 was 21,500.

<Synthesis Example 14> Synthesis of Polymer A-14 A polyamide-imide protodiene resin A-13 was obtained by the same method as described in Synthesis Example 1, except that 41.5 g of terephthalic acid was used in place of 64.6 g of 4,4'-dicarboxydiphenyl ether. The weight-average molecular weight (Mw) of polyamide-imide protodiene resin A-14 was 19,500.

<Synthesis Example 15> Synthesis of Polymer A'-1 Place 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) in a 5 L separable flask. Add 135.4 g of 2-hydroxyethyl methacrylate (HEMA) and 300 mL of γ-butyrolactone and stir at room temperature. While stirring, add 79.1 g of pyridine to obtain a reaction mixture. After the reaction heat dissipates, cool to room temperature and allow to stand for 16 hours.

Next, under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Subsequently, a solution of 179.6 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 800 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution. The resulting reaction solution was added to 3 L of ethanol to produce a precipitate containing a crude polymer. The resulting crude polymer was separated by filtration and dissolved in 1.5 L of γ-butyrolactone to obtain a crude polymer solution. The resulting crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The resulting precipitate was separated by filtration and then vacuum-dried to obtain a powdered polyamide resin, PI precursor resin A'-1. The molecular weight of PI precursor resin A'-1 was determined by gel permeation chromatography (standard polystyrene conversion), and the weight average molecular weight (Mw) was 24,000.

<Synthesis Example 16> Synthesis of Polymer A'-2 A reaction was conducted in the same manner as described in Synthesis Example 15, except that 92.9 g of 2,2'-dimethylbiphenyl-4,4'-diamine was used in place of 179.6 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyimide protodiene resin A'-2 was obtained. The weight-average molecular weight (Mw) of polyimide protodiene resin A'-2 was 23,000.

<Synthesis Example 17> Synthesis of Polymer A'-3 A polyimide protodiol resin A'-3 was obtained by the same method as described in Synthesis Example 15, except that 147.1 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used in place of 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA). The weight-average molecular weight (Mw) of polyimide protodiol resin A'-3 was 24,000.

<Synthesis Example 18> Synthesis of Polymer A'-4 A polyimide protodiol resin A'-4 was obtained by the same method as described in Synthesis Example 15, except that 87.6 g of 4,4'-diaminodiphenyl ether was used in place of 179.6 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The weight-average molecular weight (Mw) of polyimide protodiol resin A'-4 was 22,000.

<Synthesis Example 19> Synthesis of Polymer A'-5 A reaction was conducted in the same manner as described in Synthesis Example 15, except that 147.1 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used in place of 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA), and 87.6 g of 4,4'-diaminodiphenyl ether was used in place of 179.6 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyimide protodiene resin A'-5 was obtained. The weight average molecular weight (Mw) of polyimide protodiene resin A'-5 was 21,000.

<Synthesis Example 20> Synthesis of Polymer A'-6 A reaction was conducted in the same manner as described in Synthesis Example 15, except that 135.8 g of 4,4'-methylenebis(2,6-diethylaniline) was used in place of 179.6 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. Polyimide protodiene resin A'-6 was obtained. The weight-average molecular weight (Mw) of polyimide protodiene resin A'-6 was 23,000.

<Synthesis Example 21> Synthesis of Polymer A'-7 A reaction was conducted in the same manner as described in Synthesis Example 15, except that 109.1 g of pyromellitic anhydride was used in place of 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA). Polyimide protodiol resin A'-7 was obtained. The weight-average molecular weight (Mw) of polyimide protodiol resin A'-7 was 21,500.

<Synthesis Example 22> Synthesis of Polymer A'-8 Place 124.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) in a 5 L separable flask. Add 108.3 g of 2-hydroxyethyl methacrylate (HEMA) and 200 mL of γ-butyrolactone and stir at room temperature. While stirring, add 63.3 g of pyridine to obtain a reaction mixture. After the reaction heat dissipates, cool to room temperature and allow to stand for 16 hours.

Next, 25.8 g of 4,4'-dicarboxydiphenyl ether was added. Under ice cooling, a solution of 203.3 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 mL of γ-butyrolactone was added to the reaction mixture over 30 minutes while stirring. Next, a solution of 83.4 g of 4,4'-diaminodiphenyl ether (DADPE) dissolved in 500 mL of γ-butyrolactone was added over 60 minutes while stirring. After mixing with 2000 mL of γ-butyrolactone, the reaction mixture was further stirred at room temperature for 4 hours, followed by the addition of 50 mL of ethanol and stirring for 30 minutes. The resulting precipitate was removed by filtration to obtain a reaction solution.

Synthesis Examples 1 to 22 are summarized in the following table. [Table 1] Table 1 Precursor resin X1/X2 (Molar ratio) X ₁ X ₂ Synthesis example 1 A-1 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 2 A-2 2.5/7.5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 3 A-3 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 4 A-4 5/5 3,3',4,4'-Biphenyltetracarboxylic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 5 A-5 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 6 A-6 7.5/2.5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis Example 7 A-7 2.5/7.5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 8 A-8 5/5 3,3',4,4'-Biphenyltetracarboxylic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 9 A-9 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether Synthesis example 10 A-10 5/5 Pyromellitic anhydride 4,4'-Dicarboxydiphenyl ether Synthesis Example 11 A-11 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Biphenyldicarboxylic acid Synthesis example 12 A-12 5/5 4,4'-Oxydiphthalic dianhydride 4,4'-Biphenyldicarboxylic acid Synthesis example 13 A-13 5/5 4,4'-Oxydiphthalic dianhydride Benzophenone-4,4'-dicarboxylic acid Synthesis Example 14 A-14 5/5 4,4'-Oxydiphthalic dianhydride terephthalic acid Synthesis Example 15 A'-1 10/0 4,4'-Oxydiphthalic dianhydride - Synthesis Example 16 A'-2 10/0 4,4'-Oxydiphthalic dianhydride - Synthesis Example 17 A'-3 10/0 3,3',4,4'-Biphenyltetracarboxylic dianhydride - Synthesis example 18 A'-4 10/0 4,4'-Oxydiphthalic dianhydride - Synthesis example 19 A'-5 10/0 3,3',4,4'-Biphenyltetracarboxylic dianhydride - Synthesis example 20 A'-6 10/0 4,4'-Oxydiphthalic dianhydride - Synthesis Example 21 A'-7 10/0 Pyromellitic anhydride - Synthesis example 22 A'-8 8/2 4,4'-Oxydiphthalic dianhydride 4,4'-Dicarboxydiphenyl ether [Table 2] Table 2 Precursor resin _Y1 and _Y2 Synthesis example 1 A-1 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 2 A-2 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 3 A-3 2,2'-Dimethylbiphenyl-4,4'-diamine Synthesis example 4 A-4 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 5 A-5 4,4'-Diaminodiphenyl ether Synthesis example 6 A-6 4,4'-Diaminodiphenyl ether Synthesis Example 7 A-7 4,4'-Diaminodiphenyl ether Synthesis example 8 A-8 4,4'-Diaminodiphenyl ether Synthesis example 9 A-9 4,4'-Methylenebis(2,6-diethylaniline) Synthesis example 10 A-10 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis Example 11 A-11 4,4'-Diaminodiphenyl ether Synthesis example 12 A-12 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 13 A-13 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis Example 14 A-14 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis Example 15 A'-1 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis Example 16 A'-2 2,2'-Dimethylbiphenyl-4,4'-diamine Synthesis Example 17 A'-3 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 18 A'-4 4,4'-Diaminodiphenyl ether Synthesis example 19 A'-5 4,4'-Diaminodiphenyl ether Synthesis example 20 A'-6 4,4'-Methylenebis(2,6-diethylaniline) Synthesis Example 21 A'-7 2,2-Bis[4-(4-aminophenoxy)phenyl]propane Synthesis example 22 A'-8 4,4'-Diaminodiphenyl ether

<Preparation of Propellant Resin Composition> <Examples 1-22 and Comparative Examples 1-8> The propellant resin compositions of Examples 1-22 and Comparative Examples 1-8 were prepared by mixing (A) propellant resin, (B) photopolymerization initiator, (C) solvent, (D) photopolymerizable compound, (E) plasticizer, (F) hindered phenol compound, and (G) polymerization inhibitor in the amounts shown in the table below. The amounts in the table below represent the weight of each component, based on 100 parts by weight of component (A). The resulting solution was filtered through a polyethylene filter with a pore size of 0.2 μm to prepare the resin composition. The symbols in the table represent the following components. The composition was evaluated according to the above method, and the evaluation results are shown in the table below.

The above-mentioned (A-1) to (A-14) are used as the (A) polyamide-imide pro-driver resin, and the above-mentioned (A'-1) to (A'-8) are used as the (A') polyimide pro-driver resin.

The following (B-1) was used as the photopolymerization initiator (B). (B-1): 1-[4-(phenylthio)phenyl]-3-propane-1,2-dione-2-(O-acetyl oxime) (trade name: PBG-3057, manufactured by Changzhou Qiangli Electronics Co., Ltd.)

The following (C-1) to (C-3) were used as the photopolymerizable compound (C). (C-1): γ-Butyrolactone (C-2): Dimethylsulfoxide (C-3): N-methyl-2-pyrrolidone

The following (D-1) and (D-2) were used as the photopolymerizable compound (D). (D-1): Tris-(2-acryloyloxyethyl) isocyanurate (A-9300, manufactured by Shin-Nakamura Chemical Industries, Ltd.) (D-2): Tetraethylene glycol dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.)

The following (E-1) to (E-3) were used as plasticizers (E). (E-1): N-Butylbenzenesulfonamide (manufactured by Tokyo Chemical Industry Co., Ltd.) (E-2): Diphenyl phthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) (E-3): N,N-Bis(2-hydroxyethyl)-p-toluenesulfonamide (manufactured by Tokyo Chemical Industry Co., Ltd.)

In addition, the following components were used. (F-1) 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-tris(II)-2,4,6-(1H,3H,5H)-trione (G-1) 2-nitroso-1-naphthol [Table 3] Table 3 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 (A) Precursor resin A-1 100 100 100 100 100 100 100 A-2 100 A-3 100 A-4 100 A-5 100 A-6 A-7 A-8 A-9 A-10 A-11 A-12 A-13 A-14 A'-1 A'-2 A'-3 A'-4 A'-5 A'-6 A'-7 A'-8 (B) Photopolymerization initiator B-1 2 2 2 2 2 2 2 2 2 2 2 (C) Solvent C-1 225 225 225 225 225 225 225 225 225 225 225 C-2 C-3 (D) Photopolymerizable compound D-1 30 30 30 30 30 15 50 10 30 30 30 D-2 15 (E) Plasticizer E-1 5 E-2 5 E-3 5 (F) Hindered phenol compounds Fl 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (G) Polymerization inhibitor Gl 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Side chain ratio in each polymer repeating unit % 16.5 9.2 16.5 16.5 16.5 16.5 16.5 16.5 22.0 16.7 22.5 Thermogravimetric loss rate % 18.2 14.5 18.2 18.2 18.2 18.2 18.2 18.2 20.8 18.5 21.6 Residual film rate after hardening - B A A A A B A C A B B Highest resolution - B B B B B A B B A A A Minimum development time - A A A A A A A A A A A Elongation at break after reliability test - B B A B A B B C D C C [Table 4] Table 4 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 (A) Precursor resin A-1 100 100 A-2 A-3 A-4 A-5 A-6 100 A-7 100 A-8 100 A-9 100 A-10 100 A-11 100 A-12 100 A-13 100 A-14 100 A'-1 A'-2 A'-3 A'-4 A'-5 A'-6 A'-7 A'-8 (B) Photopolymerization initiator B-1 2 2 2 2 2 2 2 2 2 2 2 (C) Solvent C-1 225 225 225 225 225 225 225 225 225 180 C-2 45 C-3 225 (D) Photopolymerizable compound D-1 30 30 30 30 30 30 30 30 30 30 30 D-2 (E) Plasticizer E-1 E-2 E-3 (F) Hindered phenol compounds F-1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (G) Polymerization inhibitor G-1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Side chain ratio in each polymer repeating unit % 29.7 13.0 22.8 18.9 17.5 22.8 16.7 16.4 17.5 16.5 16.5 Thermogravimetric loss rate % 24.3 15.4 21.3 20.1 19.2 22.5 18.5 18.0 19.5 18.2 18.2 Residual film rate after hardening - C A A B B B B B B B C Highest resolution - B A A B A A A B A B B Minimum development time - B A A A A A A A A A B Elongation at break after reliability test - C C D D D D C D D B B [Table 5] Table 5 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Comparative example 8 (A) Precursor resin A-1 A-2 A-3 A-4 A-5 A-6 A-7 A-8 A-9 A-10 A-11 A-12 A-13 A-14 A'-l 100 A'-2 100 A'-3 100 A'-4 100 A'-5 100 A'-6 100 A'-7 100 A'-8 100 (B) Photopolymerization initiator B-1 2 2 2 2 2 2 2 2 (C) Solvent C-1 225 225 225 225 225 225 225 225 C-2 C-3 (D) Photopolymerizable compound D-1 30 30 30 30 30 30 30 30 D-2 (E) Plasticizer E-1 E-2 E-3 (F) Hindered phenol compounds F-1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 (G) Polymerization inhibitor G-1 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Side chain ratio in each polymer repeating unit % 27.5 34.9 28.0 35.4 36.2 30.8 30.5 31.0 Thermogravimetric loss rate % 26.4 28.8 26.7 29.4 30.5 27.8 27.8 27.2 Residual film rate after hardening - E E E E D E E D Highest resolution - D C C D C D C C Minimum development time - C B B C B C B C Elongation at break after reliability test - D E E D E E E D

As shown in the above table, Examples 1 to 22 were found to provide negative photosensitive resin compositions having high resolution, small film thickness variation during thermal curing, and suitable developing times even for thin film coating.

"Preparation of Polyamide-Imide Cured Films and Preparation of Cured Relief Patterns" As shown in the sections "Preparation of Relief Pattern Films" and "Film Thickness Change Before and After Curing" above, the negative photosensitive resin compositions of Examples 1 to 22 can be used to suitably produce polyamide-imide cured films (Examples 1-1 to 22-1) and cured relief patterns (Examples 1-2 to 22-2).

Semiconductor Device Fabrication Semiconductor devices (Examples 1-3 to 22-3) using the polyamide-imide cured films of Examples 1-1 to 22-1 as insulating layers were fabricated using conventional methods and operated without any problems. [Industrial Applicability]

By using the photosensitive resin composition of the present invention, a cured relief pattern with high resolution, minimal film thickness variation during curing, and a suitable developing time can be obtained. The present invention can be advantageously utilized in the field of photosensitive materials useful in the manufacture of electrical and electronic materials, such as semiconductor devices and multilayer wiring boards.

Claims (21)

A negative photosensitive resin composition comprises: (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent; wherein the precursor resin (A) comprises the following general formula (1): {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): [Chemical 3] A polyamide-imide protodiol resin having repeating units of {wherein X ₂ and Y ₂ are divalent organic groups and n is a positive integer}, wherein the molar fraction of the repeating units of the general formula (3) in the protodiol resin (A) is greater than 25% and less than 100%. The negative photosensitive resin composition of claim 1, wherein at least one of R ₁ and R ₂ is a monovalent organic group represented by the general formula (2). A negative photosensitive resin composition comprises: (A) a precursor resin; (B) a photopolymerization initiator; and (C) a solvent; wherein the precursor resin (A) comprises the following general formula (1): {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [wherein R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a repeating unit of a monovalent organic group, and the following general formula (3): A polyamide-imide protopolymer resin having repeating units of {wherein X ₂ and Y ₂ are divalent organic groups and n is a positive integer}, wherein in the protopolymer resin (A), the molecular weight ratio of the component represented by the general formula (2) is greater than 1% and less than 30% relative to the repeating units of the protopolymer resin. The negative photosensitive resin composition of claim 1 or 3, wherein _X2 is a divalent organic group having a structure represented by the following general formula (4): {wherein, R _x is independently an alkyl group or CF ₃ , and a is an integer from 0 to 4}. The negative photosensitive resin composition of claim 1 or 3, wherein X ₂ is a divalent organic group not having a structure represented by -NH-CO-. The negative photosensitive resin composition of claim 1 or 3, wherein _X1 is at least one selected from the group consisting of the following general formulas (5) to (8): The negative photosensitive resin composition of claim 1 or 3, wherein _Y1 and _Y2 are at least one selected from the group consisting of the following general formulas (9) to (12): {wherein, R _y each independently represents a monovalent organic group having 1 to 10 carbon atoms, b each independently represents an integer from 0 to 4, A represents a methylene group, an oxygen atom, or a sulfur atom, B each independently represents an oxygen atom or a sulfur atom, and C is selected from the following formula: At least one of the groups formed. The negative photosensitive resin composition of claim 1 or 3, wherein _X2 is at least one selected from the group consisting of the following general formulas (13) to (15): {wherein, R _z each independently represents a monovalent organic group having 1 to 10 carbon atoms, c each independently represents an integer from 0 to 4, and D represents a methylene group, a carbonyl group, or an oxygen atom}. The negative photosensitive resin composition of claim 1 or 3, wherein the precursor resin (A) is a random copolymer of repeating units of the general formula (1) and repeating units of the general formula (3). The negative photosensitive resin composition of claim 1 or 3, wherein the photopolymerization initiator (B) has a structure represented by the following general formula (16): {wherein, R ₆ , R ₇ and R ₈ are monovalent organic groups, and R ₆ and R ₇ may be linked to each other to form a ring structure}. The negative photosensitive resin composition of claim 1 or 3, wherein the photopolymerization initiator (B) is selected from the following general formula (17): (wherein, _Ra , _Rc , and _Rd are monovalent organic groups having 1 to 10 carbon atoms, _Rb is a monovalent organic group having 1 to 20 carbon atoms, and a is an integer from 0 to 2, and _Re is a monovalent organic group having 1 to 4 carbon atoms, and a ring may be formed by _Re ), the following general formula (18): (wherein, _Rf is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, _Rg is a monovalent organic group having 1 to 20 carbon atoms, and _Rh is an organic group having 1 to 10 carbon atoms), and the following general formula (19): (wherein, R _i and R _j are monovalent organic groups having 1 to 10 carbon atoms). The negative photosensitive resin composition of claim 1 or 3 further comprises (D) a polymerizable monomer. The negative photosensitive resin composition of claim 1 or 3 further comprises (E) a plasticizer. A negative photosensitive resin composition comprising: (A) a polyimide precursor resin having a thermal weight loss rate of less than 25% when maintained at 230°C for 2 hours; (B) a photopolymerization initiator; and (C) a solvent. The negative photosensitive resin composition of claim 14, wherein the precursor resin (A) comprises repeating units of the following general formula (1): {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, m is a positive integer, R ₁ and R ₂ are a hydrogen atom, a saturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, or the following general formula (2): [wherein, R ₃ , R ₄ and R ₅ are hydrogen atoms or organic groups having 1 to 3 carbon atoms, and m1 is an integer selected from 2 to 10] a monovalent organic group represented by, at least one of R ₁ and R ₂ is a group represented by the above general formula (2)}. The negative photosensitive resin composition of claim 14, wherein the polyimide precursor resin (A) is a polyamide-polyimide precursor resin. A method for producing polyamide-imide comprises the step of curing the negative photosensitive resin composition of claim 1 or 3 to form polyamide-imide. A method for producing a hardened relief pattern comprises the following steps: (1) applying a negative photosensitive resin composition as claimed in claim 1 or 3 onto a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer; (3) developing the exposed photosensitive resin layer to form a relief pattern; and (4) heating the relief pattern to form a hardened relief pattern. A polyamide-imide cured product comprises the following general formula (20): {wherein, X ₁ is a tetravalent organic group, Y ₁ is a divalent organic group, and m is a positive integer}, and the following general formula (3): {wherein, X ₂ and Y ₂ are divalent organic groups, and n is a positive integer}, and the molar fraction of the repeating units of the general formula (3) in the cured polyamide-imide is greater than 25% and less than 100%. A method for producing a cured polyamide-imide comprises the following steps: applying a photosensitive resin composition onto a substrate to form a photosensitive resin layer on the substrate; drying the obtained photosensitive resin layer; exposing the dried photosensitive resin layer to light; developing the exposed photosensitive resin layer; and heat-treating the developed photosensitive resin layer to form the cured polyamide-imide according to claim 19. A semiconductor device having a polyamide-imide cured product as claimed in claim 19 as an insulating layer disposed around wiring.