Photosensitive resin composition, cured product, and semiconductor element

Abstract

Provided is a cured product of a photosensitive resin composition. The photosensitive resin composition contains a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator. The maleimide resin is a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3). The amine (a2) includes a dimer diamine and the (meth)acrylic monomer includes a multifunctional (meth)acrylic monomer. The cured product has a Tg of 80°C or more and a coefficient of linear expansion at -20°C to 40°C of 120 ppm / °C or less.

Description

Photosensitive resin composition, cured product, and semiconductor element

[0001] The present disclosure relates to a photosensitive resin composition, a cured product, and a semiconductor device.

[0002] As semiconductor elements become more highly integrated, smaller, and more minute, insulating films used in surface protection layers, interlayer insulating layers, rewiring layers, and the like of semiconductor elements are required to have better electrical properties, heat resistance, mechanical properties, and the like. As materials for forming insulating films having these properties, photosensitive resin compositions containing alkali-soluble resins have been developed (see, for example, Patent Documents 1, 2, and 3). These photosensitive resin compositions are applied to a substrate and dried to form a resin film, which is then exposed to light and developed to obtain a patterned resin film (a patterned resin film). The patterned resin film can then be heat-cured to form a patterned cured film (a patterned cured film), which can be used as an insulating film.

[0003] JP 2008-309885 A JP 2007-057595 A International Publication No. 2010 / 073948

[0004] In modules requiring high-speed transmission, insulating films used in rewiring layers and the like are required to have low dielectric properties (low dielectric constant and low dielectric loss tangent) to support high frequencies. Furthermore, when wiring is formed on an insulating film, distortion of the wiring, wrinkles in the insulating film, and the like can cause deformation of the wiring. Deformation of the wiring can cause problems such as fluctuations in the wiring line width and fluctuations in the space between wiring lines. The present inventors have found that this wiring deformation is more likely to occur in insulating films with low dielectric properties.

[0005] Therefore, an object of the present disclosure is to provide a cured product, a semiconductor element, and a photosensitive resin composition that can achieve both low dielectric properties and suppression of wiring deformation.

[0006] One aspect of the present disclosure relates to the following cured product, semiconductor device, and photosensitive resin composition. [1] A cured product of a photosensitive resin composition, the photosensitive resin composition containing a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator, the maleimide resin being a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the amine (a2) including a dimer diamine, and the (meth)acrylic monomer including a polyfunctional (meth)acrylic monomer, the cured product having a Tg of 80°C or higher and a linear expansion coefficient at -20 to 40°C of 120 ppm / °C or lower. [2] The cured product according to [1] above, wherein the cured product has an elastic modulus at 20°C of 1000 MPa or higher. [3] The cured product according to [1] or [2] above, which is used as an insulating film and on which wiring is formed. [4] The cured product according to any one of [1] to [3] above, which is used as an insulating film for a redistribution layer. [5] A semiconductor device comprising a redistribution layer including an insulating film made of the cured product according to any one of [1] to [4] above. [6] A photosensitive resin composition containing a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator, wherein the maleimide resin is a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the amine (a2) includes a dimer diamine, and the (meth)acrylic monomer includes a polyfunctional (meth)acrylic monomer, and the cured product of the photosensitive resin composition has a Tg of 80°C or higher and a linear expansion coefficient at -20 to 40°C of 120 ppm / °C or lower. [7] The photosensitive resin composition according to [6] above, wherein the cured product has an elastic modulus of 1000 MPa or higher at 20°C. [8] The photosensitive resin composition according to any one of [6] to [7] above, which is used to form an insulating film and on which wiring is formed. [9] The photosensitive resin composition according to any one of [6] to [8] above, which is used to form an insulating film for a rewiring layer.

[0007] According to the present disclosure, it is possible to provide a cured product, a semiconductor device, and a photosensitive resin composition that can achieve both low dielectric properties and suppression of wiring deformation.

[0008] 1 is a schematic cross-sectional view showing a structure having a wiring layer produced in an example; 2 is a diagram showing a wiring design in a structure having a wiring layer produced in an example; 3 is a micrograph of a wiring produced in an example; and 4 is a diagram showing a method for measuring the deformation amount of a wiring produced in an example.

[0009] Preferred embodiments of the present disclosure will be described in detail below. However, the present disclosure is not limited to the following embodiments and can be implemented in various modifications within the scope of the present disclosure.

[0010] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit of a numerical range in a certain stage can be arbitrarily combined with the upper or lower limit of a numerical range in another stage. In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. "A or B" may include either A or B, or may include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0011] In this specification, the terms "layer" and "film" include not only structures with shapes formed over the entire surface when observed in a plan view, but also structures with shapes formed on a portion of the surface. The term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0012] In this specification, "(meth)acryloyl" means at least one of "acryloyl" and its corresponding "methacryloyl", and the same applies to other similar expressions such as (meth)acrylic acid and (meth)acrylate.

[0013] [Cured Product] The cured product according to this embodiment is a cured product of a photosensitive resin composition, the photosensitive resin composition containing a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator, the maleimide resin being a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the amine (a2) comprising a dimer diamine, the (meth)acrylic monomer comprising a polyfunctional (meth)acrylic monomer, and the cured product having a Tg of 80°C or higher and a linear expansion coefficient at -20 to 40°C of 120 ppm / °C or lower. Because the cured product is a cured product of a photosensitive resin composition containing the above components, it can have low dielectric properties (low dielectric constant and low dielectric dissipation factor). Furthermore, because the Tg and linear expansion coefficient (CTE) are within the above ranges, it is possible to suppress wiring deformation when wiring is formed on the cured product while maintaining the low dielectric properties. Therefore, the cured product can achieve both low dielectric properties and suppression of wiring deformation.

[0014] From the viewpoint of suppressing wiring deformation, the Tg (glass transition temperature) of the cured product according to this embodiment is 80° C. or higher, preferably 90° C. or higher, more preferably 100° C. or higher, and even more preferably 110° C. or higher. The upper limit of the Tg of the cured product is not particularly limited, but may be, for example, 250° C. or lower, or 200° C. or lower. Tg can be measured by the method described in the examples.

[0015] From the viewpoint of suppressing wiring deformation, the coefficient of linear expansion (CTE) of the cured product according to this embodiment at -20 to 40°C is 120 ppm / °C or less, preferably 115 ppm / °C or less, more preferably 110 ppm / °C or less, and even more preferably 100 ppm / °C or less. The lower limit of the CTE of the cured product is not particularly limited, but may be, for example, 30 ppm / °C or more, or 60 ppm / °C or more. The CTE can be measured by the method described in the examples.

[0016] The elastic modulus at 20°C of the cured product according to this embodiment is preferably 1000 MPa or more, more preferably 1200 MPa or more, and even more preferably 1600 MPa or more, from the viewpoint of further suppressing wiring deformation. The upper limit of the elastic modulus of the cured product is not particularly limited, but may be, for example, 5000 MPa or less or 3000 MPa or less. The elastic modulus at 20°C can be measured by the method described in the examples.

[0017] The cured product according to this embodiment may have a dielectric constant of less than 2.8 at 10 GHz. The cured product may have a dielectric loss tangent of less than 0.0060 at 10 GHz. The dielectric constant and dielectric loss tangent can be measured by the methods described in the examples.

[0018] The cured product according to this embodiment can be suitably used as an insulating film that serves as a base when forming wiring, and can suppress deformation of wiring formed on the insulating film. The cured product can also be suitably used as an insulating film having vias. Furthermore, the cured product is suitable as an insulating film for a rewiring layer, for example, in a semiconductor package such as an in-vehicle fan-out wafer level package (FOWLP). The semiconductor package may have a structure in which a first insulating film layer is formed on a substrate, wiring is formed on the insulating film, and then a second insulating film layer is formed on the first insulating film layer and the wiring, and vias connected to the wiring are provided in the second insulating film layer. Furthermore, multiple wiring layers and insulating films may be stacked alternately on the second insulating film layer.

[0019] The cured product can be formed using the following photosensitive resin composition.

[0020] [Photosensitive Resin Composition] The photosensitive resin composition according to this embodiment contains a maleimide resin (hereinafter also referred to as "component (A)"), a (meth)acrylic monomer (hereinafter also referred to as "component (B)"), and a photopolymerization initiator (hereinafter also referred to as "component (C)"). The maleimide resin is a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), and the amine (a2) includes a dimer diamine. The (meth)acrylic monomer includes a polyfunctional (meth)acrylic monomer.

[0021] The photosensitive resin composition according to this embodiment may further contain, as necessary, a thermal polymerization initiator (hereinafter also referred to as "component (D)"), a coupling agent (hereinafter also referred to as "component (E)"), an organic solvent (hereinafter also referred to as "component (F)"), a polymerization inhibitor, a crosslinking agent, a rust inhibitor, etc. The photosensitive resin composition according to this embodiment is a negative photosensitive resin composition. Each component used in the photosensitive resin composition according to this embodiment will be described in more detail below.

[0022] (Component (A): Maleimide Resin) The maleimide resin can be obtained by reacting a tetracarboxylic dianhydride (a1) (hereinafter also referred to as "component (a1)"), an amine (a2) (hereinafter also referred to as "component (a2)"), and maleic anhydride (a3) ​​(hereinafter also referred to as "component (a3)"). That is, the component (A) is a maleimide resin obtained by reacting the components (a1), (a2), and (a3). Here, the component (a2) contains dimer diamine. The component (A) may have multiple maleimide groups in the molecule. The component (A) may be a bismaleimide resin. The component (A) may be used alone or in combination of two or more types.

[0023] The tetracarboxylic dianhydride of component (a1) can be any known polyimide raw material. Examples of component (a1) include pyromellitic anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone ... ,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene- 2,3,5,6-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid) 1,4-phenylene, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-(ethyne-1,2-diyl)diphthalic anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, dicyclohexyl-3,4,3',4'-tetracarbo Examples of the component (a1) include norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic dianhydride, 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic-5,5',6,6'-dianhydride, and 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride. Among these, pyromellitic anhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride are preferred from the viewpoints of heat resistance and ease of availability. The component (a1) can be used alone or in combination of two or more.

[0024] The component (a1) may contain a tetracarboxylic acid dianhydride having an aromatic ring, or may contain a tetracarboxylic acid dianhydride having a fluorene skeleton. From the viewpoints of low dielectric properties, a high Tg, or a low coefficient of linear expansion (CTE), the component (a1) may contain at least one of 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride and 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride as the tetracarboxylic acid dianhydride having a fluorene skeleton.

[0025] The component (a2) contains dimer diamine. As described in, for example, Japanese Patent Application Laid-Open No. 9-12712, dimer diamine is a compound derived from a dimer acid, which is a dimer of an unsaturated fatty acid such as oleic acid. By using dimer diamine as the component (a2), the dielectric properties of the cured product can be reduced. In this embodiment, any known dimer diamine can be used without particular limitation. The dimer diamine preferably contains, for example, at least one of a compound represented by the following general formula (1) and a compound represented by the following general formula (2):

[0026]

[0027] In formulas (1) and (2), m, n, p, and q each represent an integer of 1 or greater selected so that m+n=6 to 17 and p+q=8 to 19, and the bond shown by a dashed line represents a carbon-carbon single bond or a carbon-carbon double bond. However, when the bond shown by a dashed line is a carbon-carbon double bond, formulas (1) and (2) have a structure in which the number of hydrogen atoms bonded to each carbon atom constituting the carbon-carbon double bond is reduced by one from the number shown in formulas (1) and (2).

[0028] The dimer diamine may be one represented by the above general formula (2), particularly a compound represented by the following formula (3), from the viewpoints of solubility in organic solvents, heat resistance, heat-resistant adhesion, low viscosity, etc.

[0029] Commercially available dimer diamine products include, for example, PRIAMINE 1075 and PRIAMINE 1074 (both manufactured by Croda Japan Co., Ltd.).

[0030] The (a2) component may consist solely of dimer diamine, or may contain an amine other than dimer diamine (hereinafter also referred to as "second amine"). The second amine is an amine that does not fall under the category of the above-mentioned dimer diamine. The second amine may be a diamine or triamine, or may be a diamine. By using an alicyclic diamine as the second amine, the dielectric constant can be further reduced. By using an aromatic diamine as the second amine, the elastic modulus, Tg, and CTE of the cured product can be improved.

[0031] When the second amine is a diamine, examples of the diamine include 1,3-diaminopropane, norbornanediamine, metaxylylenediamine, 4,4'-methylenedianiline, 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 9,9-bis(4- 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(aminomethyl)norbornane, 4,4'-(hexafluoroisopropylidene)dianiline, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 ２，６]decane, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 1,1-bis(4-aminophenyl)cyclohexane, 2,7-diaminofluorene, 4,4'-ethylenedianiline, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2-ethyl-6-methylaniline), 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]methane, 4,4'-bis(4-aminophenoxy)biphenyl , bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ketone, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethylbiphenyl-4,4'-diamine, (4,4'-diamino)diphenyl ether, (3,3'-diamino)diphenyl ether, paraphenylenediamine, orthophenylenediamine, metaphenylenediamine, 2,2'-dimethylbiphenyl-4,4'-diamine, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, etc. These can be used alone or in combination of two or more.

[0032] When the second amine is a triamine, examples of the triamine include tris(aminomethyl)amine, tris(2-aminoethyl)amine, tris(2-aminopropyl)amine, 2-(aminomethyl)-2-methyl-1,3-propanediamine, trimer triamine, 3,4,4'-triaminodiphenyl ether, 1,2,4-triaminobenzene, 1,3,5-triaminobenzene, 1,2,3-triaminobenzene, 1,3,5-triazine-2,4,6-triamine, 2,4,6-triaminopyrimidine, 1,3,5-tris(4-aminophenyl)benzene, and 1,3,5-tris(4-aminophenoxy)benzene.

[0033] The second amine may contain one or both of the above-mentioned diamines and triamines. Among these, from the viewpoint of photocurability, aliphatic amines and alicyclic amines are preferred, and norbornanediamine, isophoronediamine, and tris(2-aminoethyl)amine are more preferred. These may be used alone or in combination of two or more. Furthermore, the second amine may contain an amine other than a diamine or a triamine.

[0034] From the viewpoint of a high Tg and a high modulus of elasticity, the second amine may contain at least one of norbornanediamine and 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene.

[0035] The second amine may include an amine having an aromatic ring, or an amine having a biphenyl skeleton. The aromatic ring and the biphenyl skeleton may have a lower alkyl (e.g., methyl, ethyl, propyl, etc.) as a substituent. The amine having an aromatic ring may be used in combination with a tetracarboxylic acid dianhydride having an aromatic ring. Furthermore, the amine having a biphenyl skeleton may be used in combination with a tetracarboxylic acid dianhydride having a fluorene skeleton. From the viewpoint of increasing the Tg of the cured product, the amine having a biphenyl skeleton may contain at least one selected from 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-diethylbiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-diethylbiphenyl, 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl, 4,4'-diamino-3,3',5,5'-tetraethylbiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 4,4'-diamino-2,2'-dimethoxybiphenyl, and 4,4'-diamino-3,3'-dimethoxybiphenyl. The amine having a biphenyl skeleton may be a diamine having a biphenyl skeleton.

[0036] In component (a2), the molar ratio of the second amine to the total amount of amines (moles of second amine / (moles of dimer diamine+moles of second amine)) may be 0.70 or less, or may be 0.50 or less. When this ratio is 0.70 or less, the dielectric properties of the cured product can be further reduced.

[0037] When the second amine contains a diamine, the molar ratio of the diamine in the second amine to the total amount of diamine in component (a2) (number of moles of diamine in the second amine / (number of moles of dimer diamine + number of moles of diamine in the second amine)) may be 0.70 or less, or may be 0.50 or less. When this ratio is 0.70 or less, the dielectric properties of the cured product can be further reduced.

[0038] Component (A) can be produced by various known methods. For example, components (a1) and (a2) are first subjected to a polyaddition reaction at a temperature of about 60 to 120°C, preferably 70 to 90°C, for typically about 0.1 to 2 hours, preferably 0.1 to 1.0 hour. The resulting polyaddition product is then subjected to an imidization reaction, i.e., a dehydration ring-closing reaction, at a temperature of about 80 to 250°C, preferably 100 to 200°C, for about 0.5 to 30 hours, preferably 0.5 to 10 hours. The product of the dehydration ring-closing reaction is then subjected to a maleimidization reaction, i.e., a dehydration ring-closing reaction, with component (a3) ​​at a temperature of about 60 to 250°C, preferably 80 to 200°C, for about 0.5 to 30 hours, preferably 0.5 to 10 hours, to obtain the desired component (A).

[0039] In the imidization reaction or maleimidization reaction, various known reaction catalysts, dehydrating agents, and organic solvents can be used.

[0040] Examples of the reaction catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, heterocyclic tertiary amines such as pyridine, picoline, isoquinoline, and organic acids such as methanesulfonic acid, paratoluenesulfonic acid monohydrate, etc. Examples of the dehydrating agent include aliphatic acid anhydrides such as acetic anhydride, and aromatic acid anhydrides such as benzoic anhydride.

[0041] Examples of organic solvents used in the reaction include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, and pseudocumene; alcoholic solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, and phenol; ketone solvents such as acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, hexanone, cyclopentanone, cyclohexanone, isophorone, and acetophenone; cellosolves such as methyl cellosolve and ethyl cellosolve, ester solvents such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate, butyl formate, and γ-butyrolactone; and ethylene glycol mono-n-butyl ether. glycol ether solvents such as ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-iso-butyl ether, triethylene glycol monoethyl ether, triethylene glycol mono-n-butyl ether, and tetraethylene glycol mono-n-butyl ether; and nitrogen-containing compounds such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. The organic solvents can be used alone or in combination of two or more.

[0042] The organic solvent used in the reaction preferably has a boiling point of 150 to 200° C. Examples of organic solvents having a boiling point of 150 to 200° C. include 1,2,3,5-tetramethylbenzene (boiling point: 198° C.), n-propylbenzene (boiling point: 160° C.), 2-ethyltoluene (boiling point: 164° C.), 3-ethyltoluene (boiling point: 158° C.), 4-ethyl-m-xylene (boiling point: 186° C.), 1,2,3-trimethylbenzene (hemimellitene, boiling point: 176° C.), phenetole (ethoxybenzene) (boiling point: 173° C.), cumene (boiling point: 152° C.), and 1,2,4-trimethylbenzene. Examples of suitable organic solvents include methyl ether (pseudocumene, boiling point: 169°C), 1,3,5-trimethylbenzene (mesitylene, boiling point: 165°C), anisole (boiling point: 154°C), butyl cellosolve (boiling point: 171°C), methyl carbitol (boiling point: 194°C), dipropylene glycol monomethyl ether (boiling point: 188°C), dipropylene glycol dimethyl ether (boiling point: 171°C), N,N-dimethylformamide (boiling point: 153°C), and N,N-dimethylacetamide (boiling point: 165°C). Examples of suitable organic solvents having a boiling point of 150 to 200°C include petroleum-based solvents such as solvent naphtha (boiling point: 150 to 185°C), which is a distillation component of naphtha. Specific examples of solvent naphtha include T-SOL100 (trade name, manufactured by ENEOS Corporation), Swasol 1000 (trade name, manufactured by Cosmo Matsuyama Oil Co., Ltd.), and Ipsol 100 (trade name, manufactured by Idemitsu Kosan Co., Ltd.).

[0043] Component (A) can be purified by various known methods to increase its purity. For example, first, component (A) dissolved in an organic solvent and pure water are placed in a separatory funnel. The separatory funnel is then shaken and allowed to stand. Subsequently, the aqueous layer and the organic layer are separated, and only the organic layer is recovered, thereby purifying component (A).

[0044] An example of the structure of component (A) produced by the above method is shown in general formula (4) below.

[0045] In general formula (4), each X independently represents a tetravalent organic group, each Y independently represents a divalent organic group, and a represents an integer of 1 or greater. However, at least one of the multiple Ys represents the divalent organic group derived from the dimer diamine. Furthermore, X and Y may be an aliphatic group, an organic group having an alicyclic structure, or an aromatic ring, and may contain a heteroatom.

[0046] The molecular weight of component (A) can be controlled by the number of moles of component (a1) and component (a2), and the smaller the number of moles of component (a1) is relative to the number of moles of component (a2), the smaller the molecular weight can be. For the purpose of easily achieving the effects of the present disclosure, the number of moles of component (a1) per mole of component (a2), i.e., [number of moles of component (a1)] / [number of moles of component (a2)], is usually in the range of about 0.30 to 0.95, preferably 0.50 to 0.85.

[0047] From the viewpoint of solubility in solvents and heat resistance, the molecular weight of component (A) is preferably a weight average molecular weight (Mw) of 3,000 to 40,000, more preferably 4,000 to 30,000, and even more preferably 5,000 to 28,000, or 7,000 to 27,000. A weight average molecular weight of 40,000 or less tends to provide good solubility in organic solvents, while a weight average molecular weight of 3,000 or more tends to provide a sufficient effect of improving heat resistance. Mw can be measured by gel permeation chromatography (GPC) and converted using a calibration curve of standard polystyrene.

[0048] From the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of component (A) may be 40 to 90 parts by mass, 45 to 98 parts by mass, 50 to 97 parts by mass, or 55 to 95 parts by mass, where the total amount of component (A) and component (B) is taken as 100 parts by mass.

[0049] When the component (A) is obtained using the component (a2) containing a second amine, from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of the component (A) is preferably more than 50 parts by mass, and may be 55 to 99 parts by mass, 60 to 98 parts by mass, 70 to 97 parts by mass, or 80 to 95 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0050] When the component (A) is obtained using only dimer diamine as the component (a2), from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of the component (A) is preferably 40 to 75 parts by mass, or may be 45 to 75 parts by mass, 50 to 70 parts by mass, or 55 to 65 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0051] (Component (B): (meth)acrylic monomer) The (meth)acrylic monomer is a compound having a (meth)acryloyl group. The component (B) is a compound having one or more (meth)acryloyl groups, and may be a polyfunctional compound having two or more (meth)acryloyl groups. The component (B) contains at least a polyfunctional (meth)acrylic monomer having two or more (meth)acryloyl groups, and may contain a bifunctional (meth)acrylic monomer having two (meth)acryloyl groups. When the component (B) contains a polyfunctional (meth)acrylic monomer, photocurability is improved, curing can be achieved with a low exposure dose, and it becomes possible to open minute vias. The component (B) can be used alone or in combination of two or more types.

[0052] Examples of bifunctional (meth)acrylic monomers include tricyclodecane dimethanol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, dioxane glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol di(meth)acrylate, ethoxylated isocyanuric acid di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, etc. Among these, tricyclodecane dimethanol di(meth)acrylate and 1,10-decanediol di(meth)acrylate are preferred from the viewpoints of low dielectric properties and heat resistance.

[0053] The component (B) may contain another (meth)acrylic monomer other than the bifunctional (meth)acrylic monomer. Examples of the other (meth)acrylic monomer include isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tris-(2-(meth)acryloyloxyethyl)isocyanurate, pentaerythritol tetra(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, and ethoxylated trimethylolpropane tri(meth)acrylate. Among these, tris-(2-(meth)acryloyloxyethyl)isocyanurate is preferred from the viewpoints of high Tg and low CTE.

[0054] From the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of component (B) is preferably 1 to 60 parts by mass, or may be 2 to 55 parts by mass, 3 to 50 parts by mass, or 5 to 45 parts by mass, relative to 100 parts by mass of the total amount of component (A) and component (B).

[0055] When the component (A) is obtained using the component (a2) containing a second amine, from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of the component (B) is preferably less than 50 parts by mass, and may be 1 to 45 parts by mass, 2 to 40 parts by mass, 3 to 30 parts by mass, or 5 to 20 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0056] When the component (A) is obtained using only dimer diamine as the component (a2), from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and fine processability, the content of the component (B) is preferably 25 to 60 parts by mass, or may be 25 to 55 parts by mass, 30 to 50 parts by mass, or 35 to 45 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0057] From the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and photocurability, the content of the polyfunctional (meth)acrylic monomer is preferably 1 to 60 parts by mass, or may be 2 to 55 parts by mass, 3 to 50 parts by mass, or 5 to 45 parts by mass, relative to 100 parts by mass of the total amount of the (A) component and the (B) component.

[0058] When the component (A) is obtained using the component (a2) containing a second amine, from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and photocurability, the content of the polyfunctional (meth)acrylic monomer is preferably less than 50 parts by mass, and may be 1 to 40 parts by mass, 2 to 30 parts by mass, 3 to 20 parts by mass, or 5 to 15 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0059] When the component (A) is obtained using only dimer diamine as the component (a2), from the viewpoint of further improving the balance between low dielectric properties, suppression of wiring deformation, and photocurability, the content of the polyfunctional (meth)acrylic monomer is preferably 25 to 60 parts by mass, or may be 25 to 55 parts by mass, 30 to 50 parts by mass, or 35 to 45 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0060] (Component (C): Photopolymerization Initiator) The photopolymerization initiator is not particularly limited as long as it is a compound that initiates polymerization upon irradiation with actinic rays (ultraviolet rays, etc.), and examples thereof include alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, intramolecular hydrogen abstraction photopolymerization initiators, and oxime ester-based photopolymerization initiators.

[0061] Alkylphenone-based photopolymerization initiators are commercially available, for example, from IGM Resins B.V. as Omnirad 651, Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127, Omnirad 907, Omnirad 369, Omnirad 379EG, etc. Acylphosphine oxide-based photopolymerization initiators are commercially available, for example, from IGM Resins B.V. as Omnirad 819, Omnirad TPO H, etc. Intramolecular hydrogen abstraction photopolymerization initiators are commercially available, for example, from IGM Resins B.V. Omnirad MBF, Omnirad 754, etc. manufactured by BASF Japan Ltd. Oxime ester photopolymerization initiators are commercially available, for example, as Irgacure OXE01, Irgacure OXE02, etc. manufactured by BASF Japan Ltd. In order to promote the photoreaction, a titanocene photopolymerization initiator (for example, Irgacure 784 manufactured by BASF Japan Ltd.) may be used in combination.

[0062] From the viewpoints of photocurability and storage stability, the content of the component (C) may be 0.1 to 10 parts by mass, 0.5 to 8 parts by mass, or 1 to 5 parts by mass relative to 100 parts by mass of the total amount of the component (A) and the component (B).

[0063] (Component (D): Thermal Polymerization Initiator) The photosensitive resin composition according to this embodiment may further contain a thermal polymerization initiator from the viewpoint of promoting the polymerization reaction of the thermally polymerizable crosslinking agent. The component (D) is preferably a compound that decomposes when heated during curing to generate radicals and promotes the polymerization reaction between the component (D) and the component (A) or the component (B). Examples of the component (D) include organic peroxides.

[0064] Examples of organic peroxides include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methylacetoacetate peroxide, acetylacetone peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-di-t- butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, n-butyl-4,4-bis(t-butylperoxy)valerate, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, t-butyl hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl 2,5-bis(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy)diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di(3-methyl-3-methoxybutyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butyl Examples of peroxymaleic acid include peroxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m-toluoyl benzoate, t-butylperoxybenzoate, bis(t-butylperoxy)isophthalate, t-butylperoxyallyl monocarbonate, and 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone.

[0065] The content of the (D) component is not particularly limited, but may be 0.1 to 10.0 parts by mass, 0.5 to 5.0 parts by mass, or 0.7 to 3.0 parts by mass relative to 100 parts by mass of the total amount of the (A), (B), and crosslinking agent.

[0066] (Component (E): Coupling Agent) The photosensitive resin composition according to this embodiment may further contain a coupling agent from the viewpoint of improving the adhesion of a cured product of the photosensitive resin composition. Component (E) may be a silane coupling agent. The silane coupling agent may have, for example, a vinyl group, an epoxy group, a styryl group, an acryloyl group, a methacryloyl group, an amino group, a ureido group, an isocyanate group, an isocyanurate group, a mercapto group, or the like.

[0067] Examples of silane coupling agents having a vinyl group include KBM-1003 and KBE-1003 (trade names manufactured by Shin-Etsu Chemical Co., Ltd.; the same applies hereinafter). Examples of silane coupling agents having an epoxy group include KBM-303, 402, 403, KBE-402, 403, X-12-981S, and X-12-984S. Examples of silane coupling agents having a styryl group include KBM-1403. Examples of silane coupling agents having a methacryloyl group include KBM-502, 503, KBE-502, and 503. Examples of silane coupling agents having an acryloyl group include KBM-5103, X-12-1048, and X-12-1050. Examples of silane coupling agents having an amino group include KBM-602, 603, 903, 573, 575, KBE-903, 9103P, and X-12-972F. Examples of silane coupling agents having a ureido group include KBE-585. Examples of silane coupling agents having an isocyanate group include KBE-9007 and X-12-1159L. Examples of silane coupling agents having an isocyanurate group include KBM-9659. Examples of silane coupling agents having a mercapto group include KBM-802, 803, X-12-1154, and X-12-1156. The silane coupling agent may be a silane coupling agent having a methacryloyl group. The silane coupling agents may be used alone or in combination of two or more.

[0068] The content of the component (E) may be 0.01 to 10 parts by mass, 0.1 to 8 parts by mass, or 0.5 to 5 parts by mass relative to 100 parts by mass of the total amount of the components (A) and (B).

[0069] (Component (F): Organic Solvent) The photosensitive resin composition according to this embodiment may contain an organic solvent for dissolving and dispersing each component. This facilitates application of the photosensitive resin composition onto a substrate, enabling the formation of a coating film of uniform thickness. The component (F) may contain a high-boiling solvent with a boiling point of 150 to 200°C in order to improve the smoothness of the coating film surface when a thick coating film is formed, and to improve the via opening property when a thick insulating film is formed. The component (F) may be used alone or in combination of two or more types.

[0070] Examples of high boiling point solvents having a boiling point of 150 to 200°C include 1,2,3,5-tetramethylbenzene (boiling point: 198°C), n-propylbenzene (boiling point: 160°C), 2-ethyltoluene (boiling point: 164°C), 3-ethyltoluene (boiling point: 158°C), 4-ethyl-m-xylene (boiling point: 186°C), 1,2,3-trimethylbenzene (hemimellitene, boiling point: 176°C), phenetole (ethoxybenzene) (boiling point: 173°C), cumene (boiling point: 152°C), 1,2,4 ...phenetole (ethoxybenzene) (boiling point: 173°C), cumene (boiling point: 152°C), phenetole (ethoxybenzene) (boiling point: 173°C), phenetole (ethoxybenzene) (boiling point: 173°C), phenetole (ethoxybenzene) (boiling point: 173°C), phenetole (ethoxybenzene) (boiling point: 173°C), phenetole (ethoxybenzene) (boiling point: Examples of high-boiling solvents having a boiling point of 150 to 200°C include petroleum-based solvents such as solvent naphtha (boiling point: 150 to 185°C), which is a distillation component of naphtha. Specific examples of solvent naphtha are as described above. Among these, solvent naphtha, pseudocumene, and mesitylene are preferred from the viewpoint of availability. The high-boiling solvent having a boiling point of 150 to 200°C may have a boiling point of 150 to 190°C or 150 to 185°C, from the viewpoint of further improving the smoothness of the coating film surface when a thick coating film is formed and further improving the via opening property when a thick insulating film is formed.

[0071] Component (F) may contain a solvent other than the high-boiling solvent having a boiling point of 150 to 200° C. Examples of other solvents include ketones such as methyl ethyl ketone and cyclopentanone; aromatic hydrocarbons such as toluene and xylene; glycol ethers such as methyl cellosolve and propylene glycol monomethyl ether; esters such as ethyl acetate and butyl acetate; and nitrogen-containing compounds.

[0072] From the viewpoints of further improving the smoothness of the coating film surface when a thick coating film is formed and further improving the via opening property when a thick insulating film is formed, the content of component (F) is preferably an amount such that the nonvolatile components in the photosensitive resin composition are 45 to 70 mass%, 50 to 65 mass%, or 50 to 60 mass%. Here, the nonvolatile components refer to nonvolatile components excluding volatile substances (water, solvents, etc.) contained in the photosensitive resin composition, and also include components that are liquid, starch syrup-like, or wax-like at room temperature (around 25°C). The nonvolatile components of the photosensitive resin composition can be measured by the method described in the Examples.

[0073] The content of the high-boiling point solvent having a boiling point of 150 to 200°C may be 50 to 100 mass%, 60 to 100 mass%, or 70 to 100 mass%, based on the total amount of component (F), from the viewpoints of further improving the smoothness of the coating film surface when a thick coating film is formed and further improving the via opening property when a thick insulating film is formed.

[0074] (Polymerization Inhibitor) The photosensitive resin composition according to this embodiment may further contain a polymerization inhibitor from the viewpoint of storage stability.

[0075] Examples of polymerization inhibitors include 4-tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, ortho-dinitrobenzene, para-dinitrobenzene, meta-dinitrobenzene, phenanthraquinone, N-phenyl-2-naphthylamine, cupferron, 2,5-toluquinone, tannic acid, parabenzylaminophenol, tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanuric acid, and nitrosamines. One type of polymerization inhibitor may be used alone, or two or more types may be used in combination.

[0076] The content of the polymerization inhibitor may be 0.01 to 10 parts by mass, 0.05 to 5 parts by mass, or 0.10 to 2 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0077] (Rust inhibitor) The photosensitive resin composition according to this embodiment may further contain a rust inhibitor in order to suppress corrosion or prevent discoloration of copper wiring. Examples of the rust inhibitor include triazole derivatives such as benzotriazole, and tetrazole derivatives. The rust inhibitor may be used alone or in combination of two or more.

[0078] The content of the rust inhibitor may be 0.01 to 10 parts by mass, 0.03 to 5 parts by mass, or 0.05 to 3 parts by mass, per 100 parts by mass of the total amount of components (A) and (B).

[0079] (Crosslinking Agent) The photosensitive resin composition according to this embodiment may contain a crosslinking agent other than the component (B). The crosslinking agent may be a polymerizable crosslinking agent. The polymerizable group may be a photopolymerizable group or a thermally polymerizable group. Examples of the polymerizable group include an allyl group and a vinyl group from the viewpoint of dielectric properties and heat resistance. The crosslinking agent may be a polyfunctional compound having two or more polymerizable groups. Furthermore, the crosslinking agent may crosslink not only with itself but also with the component (A) or the component (B), for example, during exposure of the photosensitive layer. Furthermore, the crosslinking agent may crosslink with itself, for example, during heating of the resin film after pattern formation. The crosslinking agent may be used alone or in combination of two or more.

[0080] Examples of polymerizable crosslinking agents having an allyl group include 1,3,4,6-tetraallyl glycoluril, triallyl isocyanurate, diallyl monoglycidyl isocyanurate, diallyl monomethyl isocyanurate, diallyl isocyanurate, triallyl trimellitate, and triallyl orthoformate.

[0081] Examples of the polymerizable crosslinking agent having a vinyl group include a polyvinylbenzyl compound and a polyvinylbenzyl ether compound.

[0082] The polymerizable crosslinking agent having an allyl group or a vinyl group may contain at least one selected from the group consisting of 1,3,4,6-tetraallyl glycoluril, triallyl isocyanurate, diallyl isocyanurate, and a polyvinyl benzyl ether compound from the viewpoint of dielectric properties and microprocessability, and may contain 1,3,4,6-tetraallyl glycoluril from the viewpoint of dielectric properties.

[0083] From the viewpoint of photocurability and low dielectric properties, the content of the crosslinking agent may be 0.1 to 20 parts by mass, 0.5 to 15 parts by mass, or 1 to 10 parts by mass, relative to 100 parts by mass of the total amount of the (A) component and the (B) component.

[0084] The preparation means, conditions, etc. of the photosensitive resin composition are not particularly limited. For example, a method may be used in which predetermined amounts of various components are thoroughly and uniformly stirred and mixed using a mixer or the like, and then kneaded using a mixing roll, an extruder, a kneader, a roll, an extruder, etc. The kneading method is not particularly limited.

[0085] From the viewpoint of coatability, the viscosity of the photosensitive resin composition according to this embodiment at 25°C may be 300 to 5000 mPa·s, 350 to 4000 mPa·s, or 400 to 3000 mPa·s. The viscosity of the photosensitive resin composition at 25°C can be measured by the method described in the examples.

[0086] The photosensitive resin composition according to this embodiment has a cured product with a Tg of 80° C. or higher and a linear expansion coefficient of 120 ppm / ° C. or lower at −20 to 40° C. The cured product of the photosensitive resin composition has a linear expansion coefficient of 120 ppm / ° C. or lower at −20 to 40° C. For example, when a photosensitive layer formed using the photosensitive resin composition is exposed to an integrated light dose of 100 to 5000 mJ / cm 2 , ２ (For example, 3000 mJ / cm ２ ) and then further performing a curing treatment at 150 to 250° C. for 0.1 to 5 hours (for example, at 200° C. for 1 hour).

[0087] The photosensitive resin composition according to the present embodiment can form an insulating film that exhibits low dielectric properties and can suppress wiring deformation. The photosensitive resin composition according to the present embodiment can be used to fabricate a semiconductor element having an interlayer insulating layer formed from a cured product of the photosensitive resin composition, and an electronic device including the semiconductor element.

[0088] [Semiconductor Element] The semiconductor element according to this embodiment includes an insulating film made of the cured product according to this embodiment. The semiconductor element may be, for example, a memory, a package, or the like having a multilayer wiring structure, a rewiring structure, or the like. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk suspensions. By including an insulating film made of the cured product according to this embodiment, semiconductor elements and electronic devices with excellent reliability can be provided. The semiconductor element according to this embodiment may include a rewiring layer including an insulating film made of the cured product according to this embodiment. Semiconductor elements and electronic devices including a rewiring layer including an insulating film made of the cured product according to this embodiment are suitable as semiconductor elements and electronic devices for use in vehicles.

[0089] [Method for forming insulating film] An insulating film having via holes can be formed by photolithography using the photosensitive resin composition according to this embodiment. That is, the method for forming an insulating film according to this embodiment includes the steps of applying the photosensitive resin composition to a substrate and drying it to form a photosensitive layer, and exposing and developing the photosensitive layer to form an insulating film having via holes. The method for forming an insulating film according to this embodiment may also include the step of further heating and curing the photosensitive layer after exposure and / or development. Each step will be described in more detail below.

[0090] First, the photosensitive resin composition of the present embodiment is applied to a substrate and dried to form a photosensitive layer. In this process, a glass substrate, a semiconductor, a metal oxide insulator (e.g., TiO ２ , SiO ２ The photosensitive resin composition of the present embodiment is applied to a substrate such as a silicon nitride substrate, a silicon substrate, or a copper substrate using a spin coater or the like to form a coating film. By using the photosensitive resin composition of the present embodiment, a thick coating film with excellent smoothness can be formed by spin coating.

[0091] The substrate on which the coating film has been formed is dried using a hot plate, oven, or the like. There are no particular restrictions on the drying temperature or drying time, but drying may be performed at 80 to 150°C for 3 to 30 minutes. This results in a photosensitive layer being formed on the substrate. The thickness of the photosensitive layer may be 1 μm or more, 1 to 100 μm, 15 to 100 μm, 20 to 50 μm, or 20 to 40 μm.

[0092] Next, the photosensitive layer is exposed to actinic rays in a pattern so that via holes are formed in the photosensitive layer after development, and the exposed areas are photocured. The exposure of the photosensitive layer can be carried out using a known projection exposure method, contact exposure method, direct writing exposure method, etc.

[0093] The light source for actinic rays is not particularly limited as long as it is a commonly used, well-known light source. For example, those that effectively emit ultraviolet light, such as carbon arc lamps, mercury vapor arc lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid-state lasers such as YAG lasers, and semiconductor lasers such as gallium nitride blue-violet lasers, can be used. Also, those that effectively emit visible light, such as photographic flood lamps and sun lamps, can be used. Among these, from the viewpoint of further improving via opening properties, light sources capable of emitting monochromatic i-line light with an exposure wavelength of 365 nm, light sources capable of emitting monochromatic h-line light with an exposure wavelength of 405 nm, or light sources capable of emitting actinic rays with exposure wavelengths that are crossed by i, h, and g may be used. In particular, light sources capable of emitting monochromatic i-line light with an exposure wavelength of 365 nm may be used. Examples of light sources capable of emitting monochromatic i-line light with an exposure wavelength of 365 nm include ultra-high pressure mercury lamps. Light sources capable of emitting light with an exposure wavelength of 375 nm may also be used.

[0094] After exposure, the unexposed portions of the photosensitive layer can be removed with a developer to form an insulating film having via holes. Suitable examples of the developer include aqueous alkali solutions such as sodium carbonate, sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, and tetramethylammonium hydroxide (TMAH), as well as organic solvents such as cyclopentanone, cyclohexanone, and propylene glycol monomethyl ether acetate (PGMEA). Development using a developer can be performed by shower development, spray development, immersion development, paddle development, or the like.

[0095] After exposure, a heat treatment may be carried out. After exposure and development, the photosensitive layer may be further heat-cured. Heat-curing can be carried out, for example, using a dryer or the like at 150 to 250°C for 0.1 to 5 hours.

[0096] By the above method, an insulating film made of a cured product of the photosensitive resin composition of this embodiment can be formed.

[0097] The present disclosure will be specifically described below with reference to examples and comparative examples, but the present disclosure is not limited thereto. In each example, parts and percentages are by mass unless otherwise specified.

[0098] <Measurement Method> (Weight Average Molecular Weight) The weight average molecular weight (Mw) of the maleimide resin was measured by gel permeation chromatography (GPC). A sample prepared by dissolving maleimide resin in tetrahydrofuran (THF) to a concentration of 3% by mass was injected in an amount of 50 μL into a column (GL-R420 x 1, GL-R430 x 1, GL-R440 x 1 (all manufactured by Hitachi High-Tech Fielding Corporation)) heated to 30°C, and measurement was performed using THF as the developing solvent at a flow rate of 1.6 mL / min. The detector used was an L-3350 RI detector (manufactured by Hitachi, Ltd.), and the weight average molecular weight (Mw) was calculated from the elution time using a molecular weight / elution time curve created using standard polystyrene (manufactured by Tosoh Corporation).

[0099] (Non-volatile component (N.V.)) 0.75 g±0.25 g of the maleimide resin solution or photosensitive resin composition was weighed out using a precision balance and placed in an aluminum dish, and then dried in a hot air dryer at 150°C for 0.5 hours, and the non-volatile component (N.V.) was calculated using the following formula: N.V. (mass %)={(W3-W1) / W2}×100, where W1: mass (g) of the empty aluminum dish, W2: mass (g) of the maleimide resin solution or photosensitive resin composition before drying, and W3: mass (g) of the aluminum dish after drying plus the remaining maleimide resin or photosensitive resin composition.

[0100] (Viscosity) The viscosity of the photosensitive resin composition was measured using an E-type viscometer (product name "RE85R", manufactured by Toki Sangyo Co., Ltd.) The measurement conditions were a sample amount of 1.0 mL, a measurement temperature of 25.0°C, a preheat time of 2 minutes, and a measurement time of 3 minutes.

[0101] <Synthesis of Maleimide Resin> (Synthesis Example 1) 30.94 parts by mass of 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (manufactured by JFE Chemical Corporation, trade name "BPAF"), 133.10 parts by mass of pseudocumene (manufactured by Toyo Gosei Co., Ltd., aromatic high-boiling point solvent), 28.53 parts by mass of Solmix A-11 (trade name, manufactured by Japan Alcohol Sales Co., Ltd., alcohol-based solvent), and 31.00 parts by mass of γ-butyrolactone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., polar solvent) were added to a 0.3 L flask equipped with a condenser, a nitrogen inlet tube, a thermocouple, and a stirrer. After addition, the temperature was raised to 80°C and maintained at that temperature for 0.5 hours, and 33.83 parts by mass of dimer diamine (DDA) (trade name "PRIAMINE 1075", manufactured by Croda Japan Co., Ltd.) was added dropwise. After the dropwise addition, 5.73 parts by mass of 4,4'-diamino-2,2'-dimethylbiphenyl (manufactured by Seika Corporation, trade name "m-TB-HG") was added. After the addition, 1.73 parts by mass of an aqueous methanesulfonic acid solution (70% by mass aqueous solution, manufactured by BASF, trade name "Lutropur MSA") was added. The mixture was then heated to 160°C. After the temperature was raised, 40.00 parts by mass of toluene (manufactured by Yamaichi Chemical Industry Co., Ltd.) was added, and a dehydration ring-closing reaction was carried out at 160°C for 1 hour. The water and alcohol in the reaction solution were removed, and an intermediate polyimide resin was obtained. Subsequently, the obtained polyimide resin was cooled to 130°C, and 6.62 parts by mass of maleic anhydride (manufactured by Fuso Chemical Co., Ltd.) was added. The mixture was heated to 160°C, and a dehydration ring-closing reaction was carried out at 160°C for 4 hours. The water in the reaction solution was removed, and a solution containing a maleimide resin was obtained.

[0102] The resulting maleimide resin-containing solution was placed in a separatory funnel, and 500 parts by mass of pure water was added. The separatory funnel was shaken and allowed to stand. After standing, the aqueous and organic layers separated, and only the organic layer was recovered. The recovered organic layer was placed in a 1 L glass vessel equipped with a cooler, a nitrogen inlet tube, a thermocouple, a stirrer, and a vacuum pump, heated to 88-93°C, and water was removed. The vessel was then heated to 100°C and the solvent was partially removed for 0.5 hours under reduced pressure of 0.1 MPa from atmospheric pressure, yielding a solution of maleimide resin (A-1), which is component (A). The Mw of maleimide resin (A-1) and the N.V. of the maleimide resin (A-1) solution are shown in Table 1.

[0103] (Synthesis Examples 2 to 4) Solutions of maleimide resins (A-2) to (A-4) were obtained in the same manner as in Synthesis Example 1, except that the type and amount of each component were changed as shown in Table 1. In Table 1, "PMDA" is pyromellitic anhydride (manufactured by Daicel Corporation), which was used in place of "BPAF." Furthermore, "NBDA" is norbornanediamine (manufactured by Mitsui Fine Chemicals, Inc.), which was used in place of "m-TB-HG." In (A-4), the component substituted for "m-TB-HG" was not used. Table 1 shows the Mw of maleimide resins (A-2) to (A-4) and the N.V. of the solutions of maleimide resins (A-2) to (A-4).

[0104]

[0105] Examples 1 to 9 and Comparative Examples 1 and 2 Preparation of Photosensitive Resin Composition and Cured Sheet Photosensitive resin compositions were prepared by blending the components shown below in the compositions (unit: parts by mass) shown in Table 2. Next, using an applicator, the photosensitive resin composition was applied to a Cu foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name "3EC-M2S-VLP") so that the thickness after drying would be 100 μm, and the composition was dried in a dryer at 130°C for 30 minutes. Subsequently, using a UV irradiator (a UV irradiator with a conveyor, manufactured by GS Yuasa Corporation, using a metal halide lamp (MAL 500NAL)), the composition was irradiated with an accumulated light dose of 3000 mJ / cm. ２ After UV irradiation, the sheet was cured in a nitrogen dryer at 200°C for 1 hour. After curing, the sheet was cooled to room temperature, and the copper foil was removed by etching with an aqueous ammonium persulfate solution. The sheet was then dried at 110°C for 30 minutes to produce a cured sheet.

[0106] Component (A): Maleimide resin Solutions of maleimide resins (A-1) to (A-4) prepared in Synthesis Examples 1 to 4 above Component (B): (meth)acrylic monomer (B-1) A-DCP (trade name, tricyclodecane dimethanol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.) (B-2) A-DOD-N (trade name, 1,10-decanediol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.) (B-3) FA-731A (trade name, tris(2-acryloyloxyethyl)isocyanurate, manufactured by Resonac Corporation) Component (C): Photopolymerization initiator (C-1) Omnirad 819 (trade name, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, manufactured by IGM Resins B.V.) (C-2) Irgacure OXE02 (trade name, 1-[({1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethylidene}amino)oxy]ethanone, manufactured by BASF Japan Ltd.) Component (D): thermal polymerization initiator (D-1) DCP (trade name "Percumyl D", dicumyl peroxide, manufactured by NOF Corporation) Component (E): silane coupling agent (E-1) KBM-503 (trade name, 3-methacryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Silicones Co., Ltd.) Component (F): organic solvent (F-1) pseudocumene (1,2,4-trimethylbenzene, manufactured by Toyo Gosei Co., Ltd.)

[0107] [Measurement of Elastic Modulus and Tg] Test pieces measuring 20 mm × 10 mm were prepared using the cured sheets, and the elastic modulus at 20°C and Tg (tan δ peak) were measured using a dynamic viscoelasticity measuring device (manufactured by SII NanoTechnology Inc., product name "DMS6100") under the conditions of a frequency of 1 Hz, a measurement temperature of -40°C to 220°C, and a heating rate of 10°C / min. The results are shown in Table 2.

[0108] [Coefficient of Linear Expansion (CTE)] A test specimen measuring 30 mm x 4 mm was prepared from the cured sheet. The coefficient of linear expansion (CTE) of this test specimen was measured using a thermomechanical analyzer (manufactured by Hitachi High-Tech Science Corporation, product name "TMA / SS7100"). The measurement mode was tensile mode, the measurement load was 50 mN, the measurement atmosphere was air, the measurement temperature range was -50 to 250°C, and the heating rate was 5°C / min. The measurement result from the second run at -20 to 40°C was taken as the CTE. The results are shown in Table 2.

[0109] [Evaluation of Dielectric Properties] A test specimen measuring 50 mm x 100 mm was prepared using the cured sheet. Using this test specimen, the relative permittivity (Dk) and dielectric loss tangent (Df) at 10 GHz were measured at room temperature (20°C) using a network analyzer (manufactured by KEYSIGHT Technologies, product name "P5003A") and a split cylinder resonator (manufactured by KEYSIGHT Technologies). The measurement results were evaluated based on the following criteria. When the evaluation result was A or B, it can be said that the dielectric properties were sufficiently low. The results are shown in Table 2. <Dk Evaluation Criteria> A: Less than 2.5 B: 2.5 or more and less than 2.8 C: 2.8 or more <Df Evaluation Criteria> A: Less than 0.0040 B: 0.0040 or more and less than 0.0060 C: 0.0060 or more

[0110] [Evaluation of Wiring Deformation] A structure 100 having a wiring layer as shown in FIG. 1 was fabricated by the following procedure. A photosensitive resin composition was applied to a silicon wafer 1 (12 inches) with a Cu sputter 2 using a spin coater so that the film thickness after drying would be 25 μm. After application, the composition was dried on a hot plate at 130° C. for 10 minutes. After drying, a direct exposure machine (manufactured by Oak Manufacturing Co., Ltd., product number "FDi-5") was used to irradiate the film with light having a wavelength of 375 nm at an integrated light dose of 1000 mJ / cm. ２After the light irradiation, the substrate was subjected to a heat treatment on a hot plate at 80°C for 5 minutes. After the heat treatment, the substrate was developed twice for 25 seconds with cyclopentanone at room temperature using a paddle-type developing device (manufactured by Mikasa Co., Ltd., product name "AD-3000"), and then rinsed once for 10 seconds with PGMEA (propylene glycol monomethyl ether acetate), followed by air drying at 3000 rpm. Thereafter, the substrate was subjected to a heat treatment at 200°C for 1 hour in a nitrogen dryer, and a first insulating film 3 was formed.

[0111] Next, a sputtering apparatus (manufactured by ULVAC, product number "SIV-500") was used to form a seed layer of Ti with a thickness of 25 nm and Cu with a thickness of 150 nm on the first insulating film 3. A dry film (manufactured by Resonac Co., Ltd., product name "RY-5115") was attached to the seed layer using a vacuum laminator (manufactured by Nikko Materials Co., Ltd., product number "CV-300") under the conditions of upper plate 60°C / lower plate 40°C, pressure 0.5 MPa, and for 60 seconds. After attachment, a direct exposure machine (manufactured by Oak Manufacturing Co., Ltd., product number "FDi-5") was used to irradiate the seed layer with light of a wavelength of 375 nm at an integrated light intensity of 150 mJ / cm. ２ The light irradiation was carried out so as to form a wiring pattern with the design shown in FIG. 2 . The white areas in FIG. 2 are unirradiated areas (areas where wiring is formed), the width (target width) of the space L between the wirings is 15 μm, and the width (target width) of the wiring at the top of the space L in the figure is 5 μm. After the light irradiation, a heat treatment was carried out in a dryer (in the atmosphere) at 70°C for 5 minutes. After the heat treatment, a flat developer was used to develop the film with an alkaline aqueous solution of 1 mass % sodium carbonate at 30°C for 70 seconds. After the development, a plasma ashing was carried out with oxygen gas at 500 W for 120 seconds using a plasma asher (manufactured by Nordson Advanced Technologies, Inc., product number "AP-1000"). Thereafter, a Cu plating treatment was carried out, which consisted of acid washing, electrolytic copper plating, and water washing in that order. After the plating treatment, the dry film was peeled off with a chemical solution, and seed etching was carried out to produce a structure 100 having a wiring layer in which a wiring pattern consisting of a sputtered film 4 and Cu plating 5 was formed on an insulating film 3.

[0112] The formed wiring was observed under a microscope in region A of FIG. 2, and the appearance and wiring deformation were evaluated as follows. The results are shown in Table 2. (Appearance Evaluation) A case in which the insulating film 3 in the space L was free of wrinkles was rated "A," and a case in which the insulating film 3 in the space L was wrinkled was rated "B." FIG. 3(a) is a micrograph of a case in which the insulating film 3 in the space L was free of wrinkles and rated "A," while FIG. 3(b) is a micrograph of a case in which the insulating film 3 in the space L was wrinkled and rated "B." Note that FIG. 3(a) is a micrograph of Example 1, and FIG. 3(b) is a micrograph of Comparative Example 2. (Evaluation of Wiring Deformation) As shown in FIG. 4, the absolute value of the difference between the space width a between the wirings at position x1 and the space width b between the wirings at position x2 was calculated as the wiring deformation amount X (unit: μm). When the wiring is deformed, the space width between the wirings changes, so the larger the value of X, the more deformation there is in the wiring. The distance from x1 to x2 was 90 μm. The wire deformation was evaluated based on the value of X according to the following criteria. The results are shown in Table 2. A: X≦0.5 μm B: 0.5 μm<X≦1.0 μm C: X>1.0 μm

[0113]

[0114] 1... silicon wafer, 2... Cu sputtering, 3... insulating film, 4... sputtering film, 5... Cu plating, 100... structure

Claims

1. A cured product of a photosensitive resin composition, wherein the photosensitive resin composition contains a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator, the maleimide resin is a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the amine (a2) comprises a dimer diamine, and the (meth)acrylic monomer comprises a polyfunctional (meth)acrylic monomer, and the cured product has a Tg of 80°C or higher and a linear expansion coefficient at -20 to 40°C of 120 ppm / °C or lower.

2. The cured product according to claim 1, wherein the modulus of elasticity of the cured product at 20°C is 1000 MPa or more.

3. The cured product according to claim 1, which is used as an insulating film and on which wiring is formed.

4. The cured product according to claim 1, which is used as an insulating film for a rewiring layer.

5. A semiconductor device comprising a rewiring layer containing an insulating film made of the cured product according to any one of claims 1 to 4.

6. A photosensitive resin composition containing a maleimide resin, a (meth)acrylic monomer, and a photopolymerization initiator, wherein the maleimide resin is a reaction product of a tetracarboxylic dianhydride (a1), an amine (a2), and maleic anhydride (a3), the amine (a2) comprises a dimer diamine, the (meth)acrylic monomer comprises a polyfunctional (meth)acrylic monomer, and the cured product of the photosensitive resin composition has a Tg of 80°C or higher and a linear expansion coefficient at -20 to 40°C of 120 ppm / °C or lower.

7. The photosensitive resin composition according to claim 6, wherein the cured product has an elastic modulus of 1000 MPa or more at 20°C.

8. The photosensitive resin composition according to claim 6, which is used for forming an insulating film, and wiring is formed on the insulating film.

9. The photosensitive resin composition according to claim 6, which is used to form an insulating film for a rewiring layer.

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