Polyimide precursor composition, polyimide resin, wiring circuit board, and electronic device

Abstract

This polyimide precursor composition comprises a polyamide acid, a photosensitizer, a development accelerator, and an amine compound, wherein the amine compound is a triazole compound. The blending amount of the amine compound is 0.03-2.00 parts by mass per 100 parts by mass of the polyamide acid.

Description

Polyimide precursor composition, polyimide resin, wiring circuit board, and electronic device

[0001] The present invention relates to a polyimide precursor composition, a polyimide resin, a wiring circuit board, and an electronic device.

[0002] BACKGROUND ART Conventionally, a laminate in which a metal substrate, an insulating layer, a wiring layer, and a coating layer are laminated has been known as a wired circuit board used in an electronic device.

[0003] As a material for the insulating layer and the covering layer used in such a wired circuit board, for example, a polyimide precursor composition is known (see, for example, Patent Document 1 below).

[0004] However, polyimide resins formed from such polyimide precursor compositions have poor adhesion to wiring layers (e.g., copper wiring layers), and voids form at the boundary between the polyimide resin and the wiring layer, resulting in reduced reliability when used in wiring circuit boards. Therefore, it has been proposed to form a metal underlayer (e.g., a nickel layer or a chromium layer) between the wiring layer and the polyimide resin to improve adhesion (see, for example, Patent Document 2 below).

[0005] JP 7-179604 A JP 2013-100441 A

[0006] However, in the wired circuit board of Patent Document 2, a nickel layer is formed between the polyimide resin and the wiring layer to improve adhesion and ensure high reliability, but since the nickel layer must be formed separately, there is a problem in that production efficiency is poor.

[0007] In other words, in order to improve the reliability of the wiring circuit board, the polyimide resin formed from the polyimide precursor composition is required to have high adhesion to the wiring layer. Furthermore, it is also desired that the polyimide resin has adhesion sufficient to enable roll-to-roll production without a metal underlayer, thereby improving production efficiency.

[0008] The present invention provides a polyimide precursor composition, a polyimide resin, a wiring circuit board, and an electronic device that have excellent adhesion to a wiring layer and excellent production efficiency.

[0009] The present invention [1] includes a polyimide precursor composition comprising a polyamic acid, a photosensitizer, a development accelerator, and an amine compound, wherein the amine compound is a triazole-based compound, and the amount of the amine compound blended is 0.03 parts by mass or more and 2.00 parts by mass or less per 100 parts by mass of the polyamic acid.

[0010] The present invention [2] includes the polyimide precursor composition according to [1], wherein the amine compound is benzotriazole or a benzotriazole derivative.

[0011] The present invention [3] includes the polyimide precursor composition according to [2], in which the amine compound is benzotriazole.

[0012] The present invention [4] includes the polyimide precursor composition according to any one of [1] to [3], wherein the development accelerator is a 4-hydroxybenzoic acid.

[0013] The present invention [5] includes the polyimide precursor composition according to any one of [1] to [4], in which the amount of the amine compound blended is 1.00 parts by mass or less per 100 parts by mass of the polyamic acid.

[0014] The present invention [6] includes the polyimide precursor composition according to any one of [1] to [5], wherein the polyamic acid is a reaction product of an acid dianhydride component and a diamine component, the diamine component contains p-phenylenediamine, and the content of the p-phenylenediamine in the diamine component is 70 mol % or more.

[0015] The present invention [7] includes a polyimide resin formed from the polyimide precursor composition according to any one of [1] to [6].

[0016] The present invention [8] includes the polyimide resin according to [7], wherein the polyimide resin has a shear strength to metal of 20 MPa or more.

[0017] The present invention [9] includes a printed circuit board containing the polyimide resin according to [7] or [8].

[0018] The present invention

[10] includes an electronic device including the wired circuit board described in [9] above.

[0019] The polyimide precursor composition of the present invention contains a polyamic acid, a photosensitizer, a development accelerator, and an amine compound, the amine compound being a triazole-based compound, and the amount of the amine compound blended per 100 parts by mass of the polyamic acid is 0.03 parts by mass or more and 2.00 parts by mass or less. Therefore, the polyimide precursor composition has excellent adhesion to a wiring layer and can further improve production efficiency.

[0020] The polyimide resin of the present invention is formed from the polyimide precursor composition of the present invention, and therefore has excellent adhesion to the wiring layer and can also improve production efficiency.

[0021] The wired circuit board of the present invention contains the polyimide resin of the present invention, and therefore has excellent reliability and production efficiency.

[0022] The electronic device of the present invention includes the wired circuit board of the present invention, and therefore has excellent reliability and production efficiency.

[0023] 1A to 1E show an example of a method for forming a coating layer using a polyimide resin formed from a polyimide precursor composition according to one embodiment of the present invention, where Fig. 1A shows a lamination step, Fig. 1B shows an etching step, Fig. 1C shows a coating step, Fig. 1D shows an exposure step, and Fig. 1E shows a development step.

[0024] 1. Polyimide Precursor Composition The polyimide precursor composition of the present invention contains a polyamic acid, a photosensitizer, a development accelerator, and an amine compound. The polyimide precursor composition can be patterned by photolithography and becomes a polyimide resin by heating.

[0025] <Polyamic Acid> Polyamic acid is a polyimide precursor, for example, a reaction product of an acid dianhydride component and a diamine component. In polyamic acid, adjacent amide groups and carboxyl groups in the repeating unit react (imidization reaction) to form an imide group-containing closed ring structure, thereby forming a polyimide resin. The imidization reaction proceeds, for example, by heating.

[0026] [Acid Dianhydride Component] Examples of the acid dianhydride component include tetracarboxylic dianhydrides. Examples of the tetracarboxylic dianhydrides include aliphatic tetracarboxylic dianhydrides and aromatic tetracarboxylic dianhydrides. Preferably, aromatic tetracarboxylic dianhydrides are used.

[0027] Examples of the aliphatic tetracarboxylic dianhydride include cyclopentanetetracarboxylic dianhydride and tricarboxycyclopentylacetic dianhydride.

[0028] Examples of aromatic tetracarboxylic dianhydrides include benzenetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, biphenylsulfonetetracarboxylic dianhydride, and naphthalenetetracarboxylic dianhydride.

[0029] Examples of benzenetetracarboxylic dianhydrides include benzene-1,2,4,5-tetracarboxylic dianhydride (also known as pyromelotic dianhydride). Examples of benzophenone tetracarboxylic dianhydrides include 3,3'-4,4'-benzophenone tetracarboxylic dianhydride. Examples of biphenyl tetracarboxylic dianhydrides include 3,3'-4,4'-biphenyl tetracarboxylic dianhydride, 2,2'-3,3'-biphenyl tetracarboxylic dianhydride, 2,3,3',4'-biphenyl tetracarboxylic dianhydride, and 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride. Examples of biphenyl sulfone tetracarboxylic dianhydrides include 3,3',4,4'-biphenyl sulfone tetracarboxylic dianhydride. Examples of naphthalenetetracarboxylic dianhydrides include 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,4,5-naphthalenetetracarboxylic dianhydride, and 1,4,5,8-naphthalenetetracarboxylic dianhydride.

[0030] The acid dianhydride component may be used alone or in combination of two or more kinds.

[0031] From the viewpoint of mechanical strength, the acid dianhydride component is preferably a tetracarboxylic dianhydride. More preferably, an aromatic tetracarboxylic dianhydride is used. Even more preferably, biphenyltetracarboxylic dianhydride is used. Particularly preferably, 3,3'-4,4'-biphenyltetracarboxylic dianhydride is used. 3,3'-4,4'-biphenyltetracarboxylic dianhydride is sometimes abbreviated simply as BPDA.

[0032] [Diamine Component] Examples of the diamine component include aromatic diamines and aliphatic diamines. Preferably, aromatic diamines are used.

[0033] Examples of aromatic diamines include aromatic diamines having a single aromatic ring and aromatic diamines having multiple aromatic rings.

[0034] Examples of aromatic diamines having a single aromatic ring include phenylenediamine and its derivatives, and xylylenediamine. Phenylenediamine is preferred.

[0035] Examples of phenylenediamines include o-phenylenediamine, p-phenylenediamine, and m-phenylenediamine. Preferably, p-phenylenediamine is used. Note that p-phenylenediamine is sometimes simply abbreviated as PDA.

[0036] Examples of the phenylenediamine derivatives include those in which an alkyl group is bonded to phenylenediamine, such as 4-methyl-1,2-phenylenediamine, 4-methyl-1,3-phenylenediamine, 4,5-dimethyl-1,2-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, and 2,4,6-trimethyl-1,3-phenylenediamine.

[0037] Xylylenediamines include, for example, m-xylylenediamine and o-xylylenediamine.

[0038] Examples of aromatic diamines having multiple aromatic rings include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane, 4,4'-diaminophenylmethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-diaminobenzene, 2,5-diaminodiphenylmethane, 4,4' ... Examples of the amine compound include 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)-2,2-dimethylpropane, 4,4'-diaminobenzophenone, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, benzidine, 3,3'-dimethylbenzidine (o-tolidine), 2,2'-dimethylbenzidine (m-tolidine), 3,3'-dimethoxybenzidine, and 2,2'-dimethoxybenzidine. Preferred examples include 4,4'-diaminodiphenyl ether, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and 2,2'-dimethylbenzidine (m-tolidine). More preferred are 4,4'-diaminodiphenyl ether and 2,2'-dimethylbenzidine (m-tolidine). 4,4'-Diaminodiphenyl ether may be abbreviated simply as ODA. 2,2'-Bis(trifluoromethyl)-4,4'-diaminobiphenyl may be abbreviated simply as TFMB. 2,2'-Dimethylbenzidine (m-tolidine) may be abbreviated as m-TD.

[0039] Examples of aliphatic diamines include hexamethylenediamine, 1,8-diaminooctane, 1,12-diaminododecane, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane.

[0040] The diamine component may be used alone or in combination of two or more thereof, preferably in combination of two or more thereof.

[0041] Examples of the diamine component include a combination of p-phenylenediamine and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, a combination of p-phenylenediamine and 4,4'-diaminodiphenyl ether, and a combination of p-phenylenediamine and 2,2'-dimethylbenzidine (m-tolidine).Preferably, a combination of p-phenylenediamine and 4,4'-diaminodiphenyl ether, and a combination of p-phenylenediamine and 2,2'-dimethylbenzidine (m-tolidine) are used.

[0042] The polyamic acid includes, for example, a first structural unit represented by the following general formula (1).

[0043]

[0044] In general formula (1), R1 is an alkyl group having 1 to 3 carbon atoms, m is 0 or a positive integer of 4 or less, and n is a positive integer of 4 or less.

[0045] An example of a diamine component forming the first structural unit represented by the general formula (1) is p-phenylenediamine. That is, in the general formula (1), m is preferably 0 and n is preferably 1.

[0046] When the diamine component contains p-phenylenediamine, the molar fraction of p-phenylenediamine in the diamine component is, for example, 30 mol% to 99 mol%, preferably 40 mol% to 95 mol%, more preferably 50 mol% to 95 mol%, even more preferably 55 mol% to 90 mol%, particularly preferably 60 mol% to 90 mol%, most preferably 60 mol% to 87 mol%, or even 65 mol% to 85 mol%.

[0047] When the diamine component contains p-phenylenediamine, the molar fraction of p-phenylenediamine in the diamine component is, for example, 30 mol% or more, preferably 40 mol% or more, more preferably 50 mol% or more, even more preferably 55 mol% or more, particularly preferably 60 mol% or more, and most preferably 65 mol% or more, and for example, 99 mol% or less, preferably 95 mol% or less, more preferably 90 mol% or less, even more preferably 87 mol% or less, and particularly preferably 85 mol% or less.

[0048] The polyamic acid is obtained by reacting an acid dianhydride component and a diamine component in an organic solvent. Specifically, the polyamic acid is obtained by reacting an acid dianhydride component containing 3,3',4,4'-biphenyltetracarboxylic dianhydride with two or more diamine components in an organic solvent. Preferably, the polyamic acid is obtained by reacting an acid dianhydride component containing 3,3',4,4'-biphenyltetracarboxylic dianhydride with a diamine component containing two or more aromatic diamines in an organic solvent.

[0049] That is, the polyamic acid is obtained as a solution. The organic solvent is not particularly limited, and examples thereof include known organic solvents. Preferred examples include the organic solvents described below.

[0050] The solids concentration of the polyamic acid solution is, for example, 1% by mass to 60% by mass, or preferably 3% by mass to 50% by mass.

[0051] The solids concentration of the polyamic acid solution is, for example, 1 mass % or more, preferably 3 mass % or more, and for example, 60 mass % or less, preferably 50 mass % or less.

[0052] The content of the polyamic acid (solid content) in the polyimide precursor composition (solid content) is, for example, 30% by mass to 90% by mass, preferably 50% by mass to 85% by mass, more preferably 55% by mass to 80% by mass, even more preferably 60% by mass to 80% by mass, particularly preferably 65% ​​by mass to 80% by mass, and most preferably 70% by mass to 80% by mass.

[0053] The content of polyamic acid (solid content) in the polyimide precursor composition (solid content) is, for example, 30 mass% or more, preferably 50 mass% or more, more preferably 55 mass% or more, even more preferably 60 mass% or more, particularly preferably 65 mass% or more, and most preferably 70 mass% or more, and for example, 90 mass% or less, preferably 85 mass% or less, more preferably 80 mass% or less.

[0054] When the content of the polyamic acid (solid content) in the polyimide precursor composition (solid content) is within the above range, the polyimide precursor composition has a good viscosity.

[0055] The imide group concentration is, for example, 20% by mass or more, preferably 25% by mass, and for example, 50% by mass or less, preferably 40% by mass or less. The imide group concentration refers to the percentage of imide groups (-(CO) in a polyimide resin obtained by imidizing a polyamic acid. ２ -N-) divided by the molecular weight of the entire polyimide resin.

[0056] <Photosensitizer> The photosensitizer is a component that promotes imidization of polyamic acid in the portion irradiated with light (exposed portion) in the exposure step of the photolithography method (the portion where imidization of polyamic acid is promoted becomes less soluble in the developer used in the development step that follows the exposure step). Therefore, it is possible to improve adhesion to the metal that is the material of the wiring layer.

[0057] Examples of the photosensitizer include pyridine-based photosensitizers.

[0058] Examples of pyridine-based photosensitizers include compounds (1,4-dihydropyridine derivatives) represented by the following general formula (2): In general formula (2), R2, R3, R4, R5, and R6 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and may be the same as or different from one another. Also, in general formula (2), Ar represents an aryl group having a nitro group at the ortho position.

[0059]

[0060] In general formula (2), R2 is, for example, a hydrogen atom or a methyl group. R3 is, for example, a hydrogen atom or a methyl group. R4 is, for example, a methyl group or an ethyl group. R5 is, for example, a methyl group or an ethyl group. R6 is, for example, a methyl group or an ethyl group. Ar is, for example, a 2-nitrophenyl group.

[0061] Examples of pyridine-based photosensitizers represented by general formula (2) include 1-ethyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine, 1-methyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine, 1-propyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine, and 1-propyl-3,5-diethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine.

[0062] A preferred example of the pyridine-based photosensitizer is 1-ethyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine represented by the following formula (3).

[0063]

[0064] Pyridine-based photosensitizers (1,4-dihydropyridine derivatives) can be obtained, for example, by reacting a substituted benzaldehyde with a twice-fold molar amount of alkylpropiolate (propargylic acid alkyl ester) and a specific primary amine in glacial acetic acid under reflux (Khim. Geterotsikl. Soed., pp. 1067-1071, 1982).

[0065] The content of the photosensitizer in the polyimide precursor composition (solid content) is, for example, 1.0 mass % to 20 mass %, preferably 3.0 mass % to 15 mass %, more preferably 5.0 mass % to 12 mass %, even more preferably 5.0 mass % to 10 mass %, particularly preferably 6.0 mass % to 10 mass %, and most preferably 7.0 mass % to 9.0 mass %.

[0066] The content of the photosensitizer in the polyimide precursor composition (solid content) is, for example, 1.0 mass% or more, preferably 3.0 mass% or more, more preferably 5.0 mass% or more, even more preferably 6.0 mass% or more, particularly preferably 7.0 mass% or more, and for example, 20 mass% or less, preferably 15 mass% or less, more preferably 12 mass% or less, even more preferably 10 mass% or less, particularly preferably 9.0 mass% or less.

[0067] When the content of the photosensitizer in the polyimide precursor composition (solid content) is equal to or greater than the lower limit, the solubility of the exposed portion in a developer can be sufficiently reduced, and the adhesion to the metal material of the wiring layer can be improved.

[0068] When the content of the photosensitizer in the polyimide precursor composition (solid content) is equal to or less than the upper limit, precipitation of the solid content during storage of the polyimide precursor composition can be suppressed, and further, reduction in the thickness of the polyimide resin formed in the heat curing step after the development step of the photolithography method can be suppressed.

[0069] The amount of the photosensitizer blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 1.0 to 30.0 parts by mass, preferably 3.0 to 25.0 parts by mass, more preferably 5.0 to 20.0 parts by mass, even more preferably 7.0 to 15.0 parts by mass, and particularly preferably 9.0 to 12.0 parts by mass.

[0070] The amount of the photosensitizer blended relative to 100 parts by mass of polyamic acid (solid content) is, for example, 1.0 part by mass or more, preferably 3.0 parts by mass or more, more preferably 5.0 parts by mass or more, even more preferably 7.0 parts by mass or more, particularly preferably 9.0 parts by mass or more, and for example, 30.0 parts by mass or less, preferably 25.0 parts by mass or less, more preferably 20.0 parts by mass or less, even more preferably 15.0 parts by mass or less, particularly preferably 12.0 parts by mass or less.

[0071] <Development Accelerator> The development accelerator accelerates the dissolution of the portion that has not been irradiated with light in the exposure step of the photolithography method (unexposed portion) in the developer in the development step.

[0072] Examples of development accelerators include ester compounds. If the development accelerator has an ester bond, when a basic developer is used in the development step, the ester bond of the development accelerator is hydrolyzed by the basic developer to generate an alcohol and a carboxylic acid. This increases the hydrophilicity, making it easier for the basic developer to penetrate into the polyamic acid.

[0073] In this way, the use of an ester compound improves the permeability of the basic developer into the polyamic acid, and the unexposed areas can be more reliably removed in the development step, resulting in the formed polyimide resin having excellent patterning precision.

[0074] The development accelerators may be used alone or in combination of two or more.

[0075] Examples of the ester compound include nitrogen-free ester compounds and nitrogen-containing ester compounds. From the viewpoint of heat resistance, nitrogen-free ester compounds are preferred.

[0076] Examples of the nitrogen-free ester compound include nitrogen-free ester compounds that do not contain an aromatic ring and nitrogen-free ester compounds that contain an aromatic ring. Preferably, nitrogen-free ester compounds that contain an aromatic ring are used.

[0077] Examples of the nitrogen-free ester compound that does not contain an aromatic ring include cyclic ester compounds.

[0078] Examples of cyclic ester compounds include ε-caprolactone, glycolide, DL-lactide, tetramethylglycolide, delta-octanolactone, DL-mevalonolactone, and gamma-heptanolactone.

[0079] Examples of the aromatic ring-containing nitrogen-free ester compound include aromatic ring-containing aliphatic carboxylic acid ester compounds and aromatic carboxylic acid ester compounds. From the viewpoint of heat resistance, aromatic carboxylic acid ester compounds are preferred.

[0080] Examples of aromatic ring-containing aliphatic carboxylic acid ester compounds include aromatic ring-containing acetate ester compounds.

[0081] Examples of aromatic ring-containing acetate ester compounds include (3-methylphenyl)acetate, methyl-2-hydroxy-2-phenylacetate, methyl-2-(4-hydroxyphenyl)acetate, ethyl-2-(2-methylphenyl)acetate, ethyl-2-(4-hydroxy-3-methoxyphenyl)acetate, and ethyl-2-hydroxy-2-(3-hydroxy-4-methoxyphenyl)acetate.

[0082] Examples of aromatic carboxylic acid ester compounds include benzoic acid ester compounds, phthalic acid ester compounds, and trimellitic acid ester compounds. Benzoic acid ester compounds are preferred.

[0083] Examples of the benzoic acid ester compound include ethyl 3-hydroxybenzoate, ethyl 2-acetyloxybenzoate, ethyl 2-ethoxy-6-hydroxybenzoate, ethyl 3,5-dihydroxybenzoate, ethyl 2,4-dihydroxy-6-methylbenzoate, 2-hydroxyethyl-2-hydroxybenzoate, and phenyl benzoate (phenyl benzoate), and preferably phenyl benzoate (phenyl benzoate).

[0084] The benzoic acid ester compound also includes, for example, 4-hydroxybenzoic acid (paraben) compounds represented by the following general formula (4):

[0085]

[0086] In general formula (4), R7 is, for example, a hydrocarbon group having 4 or more carbon atoms.

[0087] Examples of 4-hydroxybenzoic acids (parabens) include butyl-4-hydroxybenzoate (butylparaben) represented by the following formula (5).

[0088]

[0089] Examples of 4-hydroxybenzoic acid (parabens) include isobutyl-4-hydroxybenzoate (isobutylparaben), hexyl-4-hydroxybenzoate (hexylparaben), 2-methylpropyl-4-hydroxybenzoate, 2-ethylhexyl-4-hydroxybenzoate, and benzyl-4-hydroxybenzoate (benzylparaben). Preferred examples of 4-hydroxybenzoic acid (parabens) include butyl-4-hydroxybenzoate (butylparaben).

[0090] Examples of phthalate compounds include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, dihexyl phthalate, diphenyl phthalate, and bis(2-methoxyethyl) phthalate.

[0091] The trimellitic acid ester compounds include trimethyl trimellitate, tripropyl trimellitate, tributyl trimellitate, and tris(2-ethylhexyl) trimellitate.

[0092] The nitrogen-free ester compound is preferably a benzoate ester compound. From the viewpoint of improving hydrophilicity, a benzoate ester compound having a phenolic hydroxyl group is more preferably used. Examples of the benzoate ester compound having a phenolic hydroxyl group include 4-hydroxybenzoic acid (parabens). Preferably, butyl-4-hydroxybenzoate (butylparaben) is used.

[0093] Examples of the nitrogen-containing ester compound include imide acrylate compounds.

[0094] Examples of imide acrylate compounds include N-acryloyloxyethylhexahydrophthalimide, N-acryloyloxyethyl-1,2,3,6-tetrahydrophthalimide, and N-acryloyloxyethyl-3,4,5,6-tetrahydrophthalimide.

[0095] Examples of development accelerators include ester compounds. Preferably, nitrogen-free ester compounds are used. More preferably, nitrogen-free ester compounds containing an aromatic ring are used. Even more preferably, aromatic carboxylic acid ester compounds are used. Particularly preferably, benzoic acid ester compounds are used. Most preferably, 4-hydroxybenzoic acid (parabens) are used. Furthermore, as 4-hydroxybenzoic acid (parabens), preferably, butyl-4-hydroxybenzoate (butylparaben) is used.

[0096] The content of the development accelerator in the polyimide precursor composition (solid content) is, for example, 5.0% by mass to 50% by mass, preferably 8.0% by mass to 40% by mass or less, more preferably 10% by mass to 40% by mass, even more preferably 10% by mass to 35% by mass, particularly preferably 10% by mass to 33% by mass, and most preferably 11% by mass to 25% by mass.

[0097] The content of the development accelerator in the polyimide precursor composition (solid content) is, for example, 5.0% by mass or more, preferably 8.0% by mass or more, more preferably 10% by mass or more, even more preferably 11% by mass or more, and for example, 50% by mass or less, preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 33% by mass or less, and particularly preferably 25% by mass or less.

[0098] The amount of the development accelerator blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 5 parts by mass to 90 parts by mass, preferably 10 parts by mass to 90 parts by mass, more preferably 12 parts by mass to 70 parts by mass, even more preferably 12 parts by mass to 60 parts by mass, particularly preferably 14 parts by mass to 50 parts by mass, and most preferably 14 parts by mass to 30 parts by mass.

[0099] The amount of the development accelerator blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, more preferably 12 parts by mass or more, even more preferably 14 parts by mass or more, and for example, 90 parts by mass or less, preferably 70 parts by mass or less, more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less.

[0100] When the blending amount of the development accelerator per 100 parts by mass of the polyamic acid (solid content) is equal to or greater than the above lower limit, excessive imidization of the polyamic acid can be suppressed. On the other hand, when the blending amount of the development accelerator per 100 parts by mass of the polyamic acid (solid content) is equal to or less than the above upper limit, compatibility is excellent and development contrast can be improved.

[0101] <Amine Compound> The amine compound protects the carboxyl group of the polyamic acid, thereby inhibiting the formation of a complex with the metal that is the wiring layer material and promoting imidization. More specifically, the amine compound can promote the imidization of the polyamic acid at the interface between the metal and the polyimide precursor composition, thereby improving the adhesion between the metal that is the wiring layer material and the polyimide resin.

[0102] The amine compound is a triazole-based compound. If the amine compound is a triazole-based compound, a layer of the triazole-based compound is formed at the interface between the metal and the polyimide precursor composition, which can inhibit the formation of a complex between the carboxyl group of the polyamic acid and the metal. As a result, the adhesion between the metal, which is the material of the wiring layer, and the polyimide resin is improved.

[0103] Examples of the triazole compound include aromatic-free triazole compounds and aromatic-containing triazole compounds, and aromatic-containing triazole compounds are preferred.

[0104] The non-aromatic triazole compounds include triazoles (specifically, 1H-triazoles) and alkyltriazoles, such as 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 1,5-dimethyltriazole, and 4,5-diethyl-1H-triazole.

[0105] Examples of aromatic-containing triazole compounds include phenyltriazole (e.g., 5-phenyl-1H-triazole) and derivatives thereof (e.g., 5-hydroxyphenyl-1H-triazole, p-ethoxyphenyltriazole), benzyltriazole and derivatives thereof, tolyltriazole and derivatives thereof, and benzotriazole (specifically, 1H-benzotriazole shown in the following formula (6)) and derivatives thereof. Preferably, benzotriazole and derivatives thereof are used.

[0106]

[0107] Examples of benzotriazole derivatives include 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, and 5-chlorobenzotriazole.

[0108] The amine compound may be a triazole compound, preferably benzotriazole or its derivatives, more preferably benzotriazole.

[0109] The amine compounds may be used alone or in combination of two or more.

[0110] The content of the amine compound in the polyimide precursor composition (solid content) is, for example, 0.010 mass % to 3.00 mass %, preferably 0.013 mass % to 2.00 mass %, more preferably 0.015 mass % to 1.50 mass %, even more preferably 0.020 mass % to 1.20 mass %, and particularly preferably 0.020 mass % to 1.00 mass %.

[0111] The content of the amine compound in the polyimide precursor composition (solid content) is, for example, 0.010 mass% or more, preferably 0.013 mass% or more, more preferably 0.015 mass% or more, even more preferably 0.020 mass% or more, and for example, 3.00 mass% or less, preferably 2.00 mass% or less, more preferably 1.50 mass% or less, even more preferably 1.20 mass% or less, and particularly preferably 1.00 mass% or less.

[0112] When the content of the amine compound in the polyimide precursor composition (solid content) is within the above range, the adhesion between the metal material of the wiring layer and the polyimide resin can be improved. Specifically, peeling does not occur at the interface between the wiring layer and the polyimide resin, and sufficient adhesion (shear strength of the polyimide resin to the metal) can be obtained for roll-to-roll production.

[0113] The amount of the amine compound to be blended relative to 100 parts by mass of polyamic acid (solid content) is 0.03 parts by mass to 2.00 parts by mass, preferably 0.03 parts by mass to 1.50 parts by mass, more preferably 0.03 parts by mass to 1.30 parts by mass, even more preferably 0.03 parts by mass to 1.00 parts by mass, particularly preferably 0.03 parts by mass to 0.60 parts by mass, and most preferably 0.05 parts by mass to 0.20 parts by mass.

[0114] The amount of the amine compound per 100 parts by mass of polyamic acid (solid content) is 0.03 parts by mass or more, preferably 0.05 parts by mass or more, and 2.00 parts by mass or less, preferably 1.50 parts by mass or less, more preferably 1.30 parts by mass or less, even more preferably 1.00 parts by mass or less, particularly preferably 0.6 parts by mass or less, and most preferably 0.20 parts by mass or less.

[0115] When the amount of the amine compound blended relative to 100 parts by mass of the polyimide precursor composition (solid content) is within the above range, the adhesion between the metal material of the wiring layer and the polyimide resin can be improved. Specifically, peeling does not occur at the interface between the wiring layer and the polyimide resin, and sufficient adhesion (shear strength of the polyimide resin to the metal) can be obtained for roll-to-roll production.

[0116] In a polyamic acid in which the imide group concentration in the polyimide resin is less than 30% by mass, the amount of the amine compound blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 0.03 to 2.00 parts by mass, preferably 0.10 to 1.50 parts by mass, more preferably 0.15 to 1.30 parts by mass, even more preferably 0.20 to 1.00 parts by mass, and particularly preferably 0.23 to 0.70 parts by mass.

[0117] In a polyamic acid in which the imide group concentration in the polyimide resin is less than 30% by mass, the amount of the amine compound per 100 parts by mass of the polyamic acid (solid content) is, for example, 0.03 parts by mass or more, preferably 0.10 parts by mass or more, more preferably 0.15 parts by mass or more, even more preferably 0.20 parts by mass or more, particularly preferably 0.23 parts by mass or more, and for example, 2.00 parts by mass or less, preferably 1.50 parts by mass or less, more preferably 1.30 parts by mass or less, even more preferably 1.00 parts by mass or less, particularly preferably 0.70 parts by mass or less.

[0118] In a polyamic acid in which the imide group concentration in the polyimide resin is 30% by mass or more, the amount of the amine compound to be blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 0.03 to 2.00 parts by mass, preferably 0.03 to 1.00 parts by mass, more preferably 0.03 to 0.50 parts by mass, even more preferably 0.03 to 0.30 parts by mass, particularly preferably 0.03 to 0.20 parts by mass, and most preferably 0.03 to 0.10 parts by mass.

[0119] In a polyamic acid in which the imide group concentration in the polyimide resin is 30% by mass or more, the amount of the amine compound blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 0.03 part by mass or more, and for example, 2.00 parts by mass or less, preferably 1.00 part by mass or less, more preferably 0.50 part by mass or less, even more preferably 0.30 part by mass or less, particularly preferably 0.20 part by mass or less, and most preferably 0.10 part by mass or less.

[0120] The amount of the amine compound blended relative to 100 parts by mass of the development accelerator is, for example, 0.01 parts by mass to 9.0 parts by mass, preferably 0.05 parts by mass to 5.0 parts by mass, more preferably 0.05 parts by mass to 4.0 parts by mass, still more preferably 0.08 parts by mass to 3.0 parts by mass, and particularly preferably 0.10 parts by mass to 2.0 parts by mass.

[0121] The amount of the amine compound blended relative to 100 parts by mass of the development accelerator is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.08 parts by mass or more, even more preferably 0.10 parts by mass or more, and is, for example, 9.0 parts by mass or less, preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, even more preferably 3.0 parts by mass or less, and particularly preferably 2.0 parts by mass or less.

[0122] When the blending amount of the amine compound relative to 100 parts by mass of the development accelerator is within the above range, the adhesion between the metal material of the wiring layer and the polyimide resin can be improved. Specifically, peeling does not occur at the interface between the wiring layer and the polyimide resin, and sufficient adhesion (shear strength of the polyimide resin to the metal) can be obtained for roll-to-roll production.

[0123] The polyimide precursor composition may contain other components, such as a photosensitizer.

[0124] Examples of photosensitizers include 3,3'-carbonylbis(7-N,N-dimethoxy)coumarin, 3-benzoylcoumarin, 3-benzoyl-7-N,N-methoxycoumarin, and benzalacetophenone.

[0125] The amount of the photosensitizer blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 0.05 to 20 parts by mass.

[0126] The polyimide precursor composition can be prepared, for example, by mixing a polyamic acid, a photosensitizer, a development accelerator, an amine compound, and other components added as needed. The polyimide precursor composition can be prepared as a diluted solution (varnish) of the polyimide precursor composition by mixing a solution of the polyamic acid, a photosensitizer, a development accelerator, an amine compound, and other components added as needed. Alternatively, the polyimide precursor composition can be prepared as a diluted solution (varnish) of the polyimide precursor composition by mixing a polyamic acid, a photosensitizer, a development accelerator, an amine compound, and other components added as needed in an organic solvent. Specifically, the diluted solution (varnish) of the polyimide precursor composition can be prepared by adding a photosensitizer, a development accelerator, an amine compound, and other components as needed to a solution of the polyamic acid obtained by reacting a tetracarboxylic dianhydride with a diamine component in an organic solvent.

[0127] The organic solvent may be, for example, an aprotic polar solvent.

[0128] Examples of aprotic polar solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethylsulfoxide, dimethylformamide, and hexamethylphosphoramide.

[0129] The amount of the organic solvent to be blended relative to 100 parts by mass of the polyamic acid (solid content) is, for example, 150 to 2000 parts by mass.

[0130] The content of the polyamic acid (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 5% by mass to 20% by mass, preferably 8% by mass to 17% by mass, and more preferably 10% by mass to 15% by mass.

[0131] The content of polyamic acid (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 5 mass% or more, preferably 7.5 mass% or more, more preferably 10 mass% or more, and for example, 20 mass% or less, preferably 17 mass% or less, more preferably 15 mass% or less.

[0132] When the content of polyamic acid (solid content) in the diluted solution (varnish) of the polyimide precursor composition is within the above range, a good viscosity of the polyimide precursor composition can be ensured.

[0133] The content of the photosensitizer (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.1 mass % to 10 mass %, preferably 0.3 mass % to 7.5 mass %, more preferably 0.5 mass % to 5.0 mass %, even more preferably 0.8 mass % to 3.0 mass %, and particularly preferably 1.0 mass % to 2.0 mass %.

[0134] The content of the photosensitizer (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.1 mass% or more, preferably 0.3 mass% or more, more preferably 0.5 mass% or more, even more preferably 0.8 mass% or more, and particularly preferably 1.0 mass% or more, and for example, 10 mass% or less, preferably 7.5 mass% or less, more preferably 5.0 mass% or less, even more preferably 3.0 mass% or less, and particularly preferably 2.0 mass% or less.

[0135] When the content of the photosensitizer (solid content) in the diluted solution (varnish) of the polyimide precursor composition is equal to or greater than the lower limit, the imidization of the polyamic acid by heating in the exposed area of ​​the polyimide precursor composition is promoted, the solubility of the exposed area in a developer is reduced, and a polyimide resin with excellent electrical properties can be formed. When the content of the photosensitizer (solid content) in the diluted solution (varnish) of the polyimide precursor composition is equal to or less than the upper limit, a reduction in the thickness of the polyimide resin pattern can be suppressed during the heating step.

[0136] The content of the development accelerator (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.5% by mass to 15% by mass, preferably 1.0% by mass to 15% by mass, more preferably 1.5% by mass to 13% by mass, even more preferably 1.8% by mass to 11% by mass, particularly preferably 2.0% by mass to 9.0% by mass, and most preferably 2.0% by mass to 8.0% by mass.

[0137] The content of the development accelerator (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.5% by mass or more, preferably 1.0% by mass or more, more preferably 1.5% by mass or more, even more preferably 1.8% by mass or more, and particularly preferably 2.0% by mass or more, and for example, 15% by mass or less, preferably 13% by mass or less, more preferably 11% by mass or less, even more preferably 9.0% by mass or less, and particularly preferably 8.0% by mass or less.

[0138] When the content of the development accelerator (solid content) in the diluted solution (varnish) of the polyimide precursor composition is equal to or greater than the lower limit, excessive imidization of the polyamic acid can be suppressed. When the content of the development accelerator (solid content) in the diluted solution (varnish) of the polyimide precursor composition is equal to or less than the upper limit, sufficient compatibility can be ensured, and development contrast can be improved.

[0139] The content of the amine compound (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.001 mass % to 0.50 mass %, preferably 0.002 mass % to 0.45 mass %, more preferably 0.003 mass % to 0.40 mass %, and even more preferably 0.003 mass % to 0.35 mass %.

[0140] The content of the amine compound (solid content) in the diluted solution (varnish) of the polyimide precursor composition is, for example, 0.001 mass% or more, preferably 0.002 mass% or more, more preferably 0.003 mass% or more, and for example, 0.50 mass% or less, preferably 0.45 mass% or less, more preferably 0.40 mass% or less, and even more preferably 0.35 mass% or less.

[0141] When the content of the amine compound (solid content) in the diluted solution (varnish) of the polyimide precursor composition is within the above range, the adhesion between the metal that is the material of the wiring layer and the polyimide resin can be improved.

[0142] The polyimide precursor composition (or varnish) forms a polyimide resin by heat curing.

[0143] 2. Polyimide Resin The polyimide resin is formed from the polyimide precursor composition. The polyimide resin is used, for example, as a coating layer for a printed circuit board.

[0144] The shear strength of the polyimide resin to a metal is, for example, 4 MPa or more, preferably 5 MPa or more, more preferably 10 MPa or more, even more preferably 15 MPa or more, and particularly preferably 20 MPa or more. The upper limit of the shear strength of the polyimide resin to a metal is not particularly limited, and is, for example, 100 MPa or less.

[0145] When the shear strength of the polyimide resin to metal is equal to or greater than the lower limit, the polyimide resin has sufficient adhesion for roll-to-roll production, thereby improving production efficiency.

[0146] The shear strength of the polyimide resin against metal can be measured by the method described in the examples below.

[0147] 3. Wired Circuit Board The wired circuit board includes, for example, a base material, an insulating layer, a wiring layer, and a coating layer in this order in the thickness direction. The coating layer is disposed so as to cover the wiring layer. The coating layer contains a polyimide resin formed from the polyimide precursor composition described above.

[0148] The shape of the substrate may be, for example, a film (including a sheet) having a predetermined thickness, or a plate.

[0149] Examples of materials for the substrate include metals, preferably aluminum, stainless steel, and copper, and more preferably stainless steel.

[0150] The thickness of the substrate is, for example, 5 μm to 300 μm, preferably 10 μm to 200 μm, and more preferably 20 μm to 150 μm.

[0151] The material of the insulating layer is not particularly limited, and known materials can be used. A preferred example of the material of the insulating layer is a polyimide resin. Alternatively, a polyimide resin formed from the polyimide precursor composition described above may be used.

[0152] The thickness of the insulating layer is, for example, 1 μm to 50 μm, or preferably 5 μm to 30 μm.

[0153] Examples of materials for the wiring layer include metals, preferably chromium and copper, and more preferably copper.

[0154] The material for the wiring layer may be used alone or in combination of two or more kinds, preferably a combination of chromium and copper.

[0155] The thickness of the wiring layer is, for example, 1 μm to 100 μm, preferably 5 μm to 50 μm, and more preferably 10 μm to 30 μm.

[0156] Next, a method for forming a coating layer of polyimide resin from the above polyimide precursor composition on the wired circuit board 1 will be described with reference to FIGS. 1A to 1E.

[0157] 1A, an insulating layer material (e.g., a polyimide precursor composition) is first applied to a substrate S and cured to form an insulating layer 10. A metal wiring layer material is then laminated as a base by sputter deposition to form a metal layer 21. A plating resist 30 having a reverse pattern to a predetermined wiring pattern is then formed using a dry film resist, and then a conductor pattern 20 (wiring layer) that forms the predetermined wiring pattern is formed by copper plating 22 in the portions of the metal layer 21 where the plating resist is not formed by a semi-additive method (lamination process).

[0158] Thereafter, as shown in FIG. 1B, the plating resist 30 is removed by chemical etching, and the metal layer 21 on which the plating resist was formed is also removed by chemical etching (etching step).

[0159] Next, as shown in FIG. 1C, a diluted solution (varnish) of the polyimide precursor composition is applied and then dried by heating to form a coating 40A (application step).

[0160] Examples of the application method include spin coating and screen printing.

[0161] The drying temperature is, for example, 100° C. to 200° C. The drying time is, for example, 1 minute to 15 minutes.

[0162] The thickness of the coating 40A is in the range of, for example, 1 μm to 50 μm, or preferably 10 μm to 40 μm.

[0163] The coating 40A has a thickness of, for example, 1 μm or more, preferably 10 μm or more, and for example, 50 μm or less, preferably 40 μm or less.

[0164] 1D, the coating 40A is irradiated with ultraviolet light through a photomask M (exposure step). The photomask M has openings Ma corresponding to the pattern shape of the conductor pattern 20 (wiring layer).

[0165] The wavelength of the irradiated ultraviolet light is, for example, 300 nm to 450 nm. The cumulative irradiation amount of the ultraviolet light is, for example, 100 mJ / cm. ２ ~1000mJ / cm ２ is.

[0166] The film 40A is irradiated with ultraviolet light through the photomask M, resulting in exposed portions 41 and unexposed portions 42. After the ultraviolet light irradiation, the film 40A may be preheated.

[0167] The preheating temperature is, for example, 100° C. to 300° C. The preheating time is, for example, 1 minute to 30 minutes.

[0168] Next, as shown in FIG. 1E, the coating 40A is developed. Specifically, the unexposed portions 42 of the coating 40A are dissolved and removed by a developer (development step). After development, the exposed portions 41 are heated. As a result, a polyimide resin is formed in the exposed portions 41 of the coating 40A, forming a coating layer 40B.

[0169] The developer may be, for example, a basic developer. Examples of the basic developer include an inorganic alkaline solution and an organic alkaline solution. Examples of the inorganic alkaline solution include an aqueous solution of sodium hydroxide and an aqueous solution of potassium hydroxide. Examples of the organic alkaline solution include an aqueous solution of tetramethylammonium hydroxide (TMAH) and a TMAH / equinene solution. A TMAH / equinene solution is preferred.

[0170] Examples of the developing method include a dipping method, a spray method, and a puddle method.

[0171] The heating temperature is, for example, 300° C. to 450° C. The heating time is, for example, 1 hour to 10 hours.

[0172] In this manner, a laminate is formed on the substrate S, which is made of the insulating layer 10, the conductor pattern 20 (wiring layer) having a predetermined pattern shape, and the coating layer 40B made of polyimide resin and coating the conductor pattern 20 (wiring layer). This results in the wired circuit board 1.

[0173] The wired circuit board produced by this method does not require the formation of a metal underlayer (for example, a nickel layer or a chromium layer), and therefore has excellent production efficiency.

[0174] 4. Electronic Device The electronic device includes the above-described printed circuit board.

[0175] Examples of electronic devices include notebook personal computers and mobile phones.

[0176] The polyimide precursor composition of the present invention contains a polyamic acid, a photosensitizer, a development accelerator, and an amine compound, the amine compound being a triazole-based compound, and the amount of the amine compound per 100 parts by mass of the polyamic acid is 0.03 parts by mass or more and 2.00 parts by mass or less. Therefore, the polyimide precursor composition has excellent adhesion to a wiring layer and can further improve production efficiency.

[0177] Specifically, in the polyimide precursor composition of the present invention, the amine compound is a triazole-based compound, and the amount of the amine compound is 0.03 parts by mass or more and 2.00 parts by mass or less per 100 parts by mass of polyamic acid. Therefore, a layer of the triazole-based compound is formed at the interface between the metal and the polyimide precursor composition, which can inhibit the formation of a complex between the carboxyl group of the polyamic acid and the metal. As a result, a polyimide resin with excellent adhesion to the wiring layer can be formed.

[0178] Therefore, the polyimide resin formed from the polyimide precursor composition of the present invention has excellent adhesion, which eliminates the need for forming a nickel layer, and allows the production of wired circuit boards and electronic devices with excellent reliability and production efficiency.

[0179] The present invention will be described in more detail below with reference to examples, comparative examples, and reference examples. It should be noted that the present invention is not limited to the examples, comparative examples, and reference examples. The specific numerical values ​​of the blending ratios (contents), physical properties, parameters, etc. used in the following description can be replaced with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (contents), physical properties, parameters, etc. described in the above-mentioned "Modes for Carrying Out the Invention."

[0180] <Details of Components> The trade names and abbreviations of the components used in each example and each comparative example are described in detail below.

[0181] BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride PDA: p-phenylenediamine TFMB: 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl ODA: 4,4'-diaminodiphenyl ether m-TD: 2,2'-dimethylbenzidine (m-tolidine) NMP: N-methyl-2-pyrrolidone BTA: Benzotriazole NKS-4: 1-ethyl-3,5-dimethoxycarbonyl-4-(2-nitrophenyl)-4-hydropyridine n-BP: Butyl-4-hydroxybenzoate TMAH: Tetramethylammonium hydroxide Equinene: Ethanol-based mixed solvent

[0182] Preparation of Polyimide Precursor Composition Example 1 First, polyamic acid (A) was synthesized. Specifically, in a 1000 mL four-neck flask, a solution containing 94.15 g (320 mmol) of BPDA, 27.68 g (256 mmol) of PDA, 20.50 g (64 mmol) of TFMB, and 874 g of NMP was stirred at room temperature (25°C) (synthesis of polyamic acid (A)). This resulted in an NMP solution containing polyamic acid (A). The synthesized polyamic acid (A) contained the first structural unit described above. In this polyamic acid (A), m in the general formula (1) representing the first structural unit is 0, and n in the general formula (1) is 1. The proportion of the first structural unit in this polyamic acid (A) was 80 mol%. When a polyimide resin was formed using polyamic acid (A), the imide group concentration was 28.7 mass%.

[0183] Next, 0.36 g (0.003 mol) of BTA (amine compound) was added to the NMP solution containing polyamic acid (A) and stirred at room temperature (25°C). After stirring, NKS-4 (photosensitizer) and n-BP (development accelerator) were mixed to prepare a varnish of a photosensitive polyimide precursor composition. The polyimide precursor composition was prepared by mixing the above polyamic acid (A) (solids), NKS-4 (photosensitizer), n-BP (development accelerator), and BTA (amine compound) in a composition ratio (mass ratio) of 100:10:50:0.25. This resulted in a solution (varnish) of the polyimide precursor composition of Example 1.

[0184] Examples 2 and 3, Comparative Examples 1 to 3, Reference Examples 1 and 2 The polyimide precursor compositions of each Example, Comparative Example, and Reference Example were prepared in the same manner as the polyimide precursor composition of Example 1, except that the amount of the amine compound was changed so as to obtain the composition ratio shown in Table 1. The polyimide precursor compositions of Comparative Example 1 and Reference Examples 1 and 2 had the same composition and did not contain an amine compound.

[0185] Example 4 A polyimide precursor composition of Example 4 was prepared in the same manner as the polyimide precursor composition of Example 1, except that polyamic acid (A) was changed to polyamic acid (B) and the amounts of the development accelerator and amine compound were changed so as to obtain the composition ratio shown in Table 2. The preparation of polyamic acid (B) is described below.

[0186] In a 500 mL four-neck flask, a solution containing 20.0 g (68.0 mmol) of BPDA, 6.24 g (57.8 mmol) of PDA, 2.04 g (10.2 mmol) of ODA, and 174 g of NMP was stirred at room temperature (25°C) (synthesis of polyamic acid (B)). This resulted in an NMP solution containing polyamic acid (B). The synthesized polyamic acid (B) contains the first structural unit described above. In this polyamic acid (B), m in the general formula (1) representing the first structural unit is 0, and n in the general formula (1) is 1. The proportion of the first structural unit in this polyamic acid (B) is 85 mol%. When a polyimide resin was formed using polyamic acid (B), the imide group concentration was 32.6 mass%.

[0187] Examples 5 to 8 and Comparative Example 4 Polyimide precursor compositions of each Example and Comparative Example 4 were prepared in the same manner as the polyimide precursor composition of Example 4, except that the amount of the amine compound was changed so as to obtain the composition ratio shown in Table 2. Note that the polyimide precursor composition of Comparative Example 4 did not contain an amine compound.

[0188] Example 9 A polyimide precursor composition of Example 9 was prepared in the same manner as the polyimide precursor composition of Example 1, except that polyamic acid (A) was changed to polyamic acid (C) and the amounts of the development accelerator and amine compound were changed so as to obtain the composition ratio shown in Table 3. The preparation of polyamic acid (C) is described below.

[0189] In a 3000 mL four-neck flask, a solution containing 182.90 g (622 mmol) of BPDA, 46.21 g (427 mmol) of PDA, 40.43 g (190 mmol) of m-TD, and 1656 g of NMP was stirred under heating (80°C) (synthesis of polyamic acid (C)). This resulted in an NMP solution containing polyamic acid (C). The synthesized polyamic acid (C) contained the first structural unit described above. The proportion of the first structural unit in this polyamic acid (C) was 69.2 mol%. The imide group concentration in a polyimide resin formed using polyamic acid (C) was 32.3 mass%.

[0190] Examples 10 and 11 and Comparative Example 5 Polyimide precursor compositions of each example and Comparative Example 5 were prepared in the same manner as the polyimide precursor composition of Example 9, except that the amount of the amine compound was changed so as to obtain the composition ratio shown in Table 3. Note that the polyimide precursor composition of Comparative Example 5 did not contain an amine compound.

[0191] <Evaluation> [Appearance] A solution (varnish) of the polyimide precursor composition of each Example and Comparative Example was spin-coated onto a copper foil (300 mm × 300 mm, thickness: 100 μm) and heated at 165° C. for 3 minutes to obtain a coating film with a thickness of 20 μm. Next, half of the obtained coating film was covered with SUS foil and exposed to an exposure dose of 200 mJ / cm using an exposure machine. ２ After that, the film was heated for 5 minutes at 185° C. As a result, a laminate (copper foil / polyimide resin) containing polyimide resin and patterned into two parts, having a thickness of 20 μm, was obtained.

[0192] In Reference Example 1, a laminate (copper foil / chromium layer / polyimide resin) was obtained in the same manner as above, except that a chromium layer was formed as a metal underlayer on a copper foil, and then a solution (varnish) of the polyimide precursor composition of Reference Example 1 was spin-coated onto the chromium layer. In Reference Example 2, a laminate (copper foil / nickel layer / polyimide resin) was obtained in the same manner as above, except that a nickel layer was formed as a metal underlayer on a copper foil, and then a solution (varnish) of the polyimide precursor composition of Reference Example 2 was spin-coated onto the nickel layer.

[0193] In the resulting laminates containing the polyimide resin of each Example, Comparative Example, and Reference Example, the interface between the polyimide resin and the copper foil at the boundary between the unexposed and exposed areas (note that in Reference Examples 1 and 2, the interface between the polyimide resin and the metal underlayer and the interface between the metal underlayer and the copper foil) was visually inspected. The appearance was evaluated according to the following criteria. The results are shown in Tables 1 to 3.

[0194] {Criteria} A: No peeling at the interface, adherence B: Peeling at the interface

[0195] <Evaluation> [Shear Strength] A solution (varnish) of the polyimide precursor composition of each Example and Comparative Example was spin-coated onto a copper foil (300 mm × 300 mm, thickness: 100 μm) and heated at 165° C. for 3 minutes to obtain a coating film with a thickness of 20 μm. Then, the coating film was exposed to light at a dose of 200 mJ / cm using an exposure machine. ２ After that, the resist pattern was exposed to light at 185° C. for 5 minutes, and then developed by dipping the resist pattern in a TMAH / equine solution for 2 seconds each time. After rinsing with deionized water, the resist pattern was dried at 350° C. to obtain a wiring circuit board.

[0196] In Reference Example 1, a wiring circuit board was obtained in the same manner as above, except that a chromium layer was formed as a metal underlayer on a copper foil, and then the chromium layer was spin-coated with a solution (varnish) of the polyimide precursor composition of Reference Example 1. In Reference Example 2, a wiring circuit board was obtained in the same manner as above, except that a nickel layer was formed as a metal underlayer on a copper foil, and then the nickel layer was spin-coated with a solution (varnish) of the polyimide precursor composition of Reference Example 2.

[0197] The resulting wiring circuit boards containing the polyimide resins of each Example, Comparative Example, and Reference Example were subjected to a shear test using a Bond Tester 4000 Plus (manufactured by Nordson DAGE) and evaluated according to the following criteria. The results are shown in Tables 1 to 3.

[0198] The shear test involves setting a tool attached to a load sensor at a predetermined height from the contact surface between the copper foil and the polyimide resin, pressing the polyimide resin with the tool, and measuring the load at which the polyimide resin peels off. For samples that successfully peeled off at the interface between the copper foil and the polyimide resin, the load at that time was taken as the shear strength of the polyimide resin against the metal (copper foil). Since the shear strength was calculated in gf, it was converted to MPa.

[0199] {Criteria} A: 20 MPa or more B: 4 MPa or more, less than 20 MPa C: Less than 4 MPa or not measurable

[0200]

[0201]

[0202]

[0203] The above invention is provided as an exemplary embodiment of the present invention, but this is merely an example and should not be interpreted as limiting. Modifications of the present invention that are obvious to those skilled in the art are intended to be included in the scope of the following claims.

[0204] The polyimide resin formed from the polyimide precursor composition containing the polyamic acid of the present invention is suitable for use in an insulating layer and / or a coating layer used in a wiring circuit board. The wiring circuit board using the polyimide resin is suitable for use in electronic devices such as notebook personal computers and smartphones.

[0205] REFERENCE SIGNS LIST 1 Wired circuit board S Substrate 10 Insulating layer 20 Conductor pattern (wiring layer) 21 Metal layer 22 Copper plating 30 Plating resist 40A Coating 40B Covering layer 41 Exposed portion 42 Unexposed portion

Claims

1. A polyimide precursor composition comprising a polyamic acid, a photosensitizer, a development accelerator, and an amine compound, wherein the amine compound is a triazole-based compound, and the amount of the amine compound compounded with respect to 100 parts by mass of the polyamic acid is 0.03 parts by mass or more and 2.00 parts by mass or less.

2. The polyimide precursor composition according to claim 1, wherein the amine compound is benzotriazole or a benzotriazole derivative.

3. The polyimide precursor composition according to claim 2, wherein the amine compound is benzotriazole.

4. The polyimide precursor composition according to claim 1, wherein the development accelerator is 4-hydroxybenzoic acids.

5. The polyimide precursor composition according to claim 1, wherein the amount of the amine compound compounded with respect to 100 parts by mass of the polyamic acid is 1.00 parts by mass or less.

6. The polyimide precursor composition according to claim 1, wherein the polyamic acid is a reaction product of an acid dianhydride component and a diamine component, the diamine component contains p-phenylenediamine, and the content ratio of p-phenylenediamine in the diamine component is 70 mol% or more.

7. A polyimide resin formed from the polyimide precursor composition according to any one of claims 1 to 6.

8. The polyimide resin according to claim 7, wherein the shear strength of the polyimide resin with respect to a metal is 20 MPa or more.

9. A wiring circuit board comprising the polyimide resin according to claim 8.

10. An electronic device comprising the wiring circuit board according to claim 9.

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