TWI856214B - Resin composition, method for producing cured product, cured product, coating, surface protective film, and electronic component - Google Patents

Abstract

A resin composition comprises: (A) a polyimide precursor having a structural unit represented by the following formula (1); and (C) one or more selected from the group consisting of an antioxidant and a compound having a structure represented by the following formula (21).

Description

Resin composition, method for producing cured product, cured product, coating, surface protective film, and electronic component

The present invention relates to a resin composition, a method for producing a cured product, a cured product, a covering coating, a surface protective film and an electronic component.

Polyimide resins are mainly used as insulators for semiconductor components due to their heat resistance, and have now become an indispensable chemical material in electronic devices such as computers, smartphones, cars, and TVs. In recent years, polyimide resins are expected to be used in power modules. Power modules are used in a variety of products such as direct current-direct current (DC-DC) converters for civil equipment, inverters for automotive or air conditioning purposes, and transportation vehicles such as trains and Shinkansen and their power transmission and distribution. The scope of application and market size are increasing.

Patent document 1 describes a resin composition comprising a polyimide precursor or a polybenzoxazole precursor, a photosensitizer, and a phenol compound. [Prior art document] [Patent document]

Patent document 1: Japanese Patent Publication No. 2009-230098

An object of the present invention is to provide a resin composition capable of forming a cured product whose appearance discoloration after curing and after a pressure cooker test is suppressed, a method for producing the cured product, the cured product, a covering coating, a surface protective film, and an electronic component.

In order to achieve miniaturization, low thermal resistance and high reliability in power modules, a structure is being studied in which a semiconductor chip is connected to a direct copper bonding (DBC) substrate using copper pins and sealed using epoxy resin or the like. In this structure, a wiring path is formed using copper wiring formed on a DCB substrate, a semiconductor chip including a hardened material, and copper pins. Therefore, the inventors and others have found that in the peripheral materials thereof, when exposed to the high voltage and high temperature conditions of the power module, at least one of discoloration of the hardened material on the copper and discoloration of the copper will occur. The inventors and others have conducted diligent research and have invented a resin composition that suppresses discoloration of the hardened material on the copper or the copper by a combination of specific components.

According to the present invention, the following resin compositions and the like are provided. 1. A resin composition comprising: (A) a polyimide precursor having a structural unit represented by the following formula (1); and (C) one or more selected from the group consisting of an antioxidant and a compound having a structure represented by the following formula (21). [Chemical 1] (In formula (1), _X1 is a tetravalent group having one or more aromatic groups, _-COOR1 and -CONH- are adjacent to each other, and _-COOR2 and -CO- are adjacent to each other. _Y1 is a divalent organic group. _R1 and _R2 are independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.) [Chemistry 2] 2. The resin composition according to 1, wherein _R1 and _R2 are hydrogen atoms. 3. The resin composition according to 1 or 2, wherein the antioxidant is a compound having a structure represented by the following formula (11). (In formula (11), R ₁₁ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms.) 4. The resin composition according to any one of 1 to 3, wherein the antioxidant is a compound represented by the following formula (12). [Chemical 4] (In formula (12), R ₁₁ is a hydrogen atom, an aliphatic alkyl group having 1 to 10 carbon atoms, or an aromatic alkyl group having 6 to 30 carbon atoms. R ₁₂ is an aliphatic alkyl group having 1 to 10 carbon atoms, or an aromatic alkyl group having 6 to 30 carbon atoms. When there are two or more R _12s , the two or more R _12s may be the same or different. n is an integer from 0 to 3.) 5. The resin composition as described in 3 or 4, wherein R ₁₁ is a hydrogen atom. 6. The resin composition as described in 3, wherein the compound having a structure represented by formula (11) is a compound having two or more structures represented by formula (11). 7. The resin composition as described in any one of 1 to 6, further comprising a solvent. 8. A method for producing a cured product, comprising: a step of applying the resin composition described in any one of 1 to 7 on a substrate and drying it to form a resin film; and a step of heat-treating the resin film. 9. A cured product, obtained by curing the resin composition described in any one of 1 to 7. 10. A covering coating or a surface protective film, obtained by using the cured product described in 9. 11. An electronic component, comprising the covering coating or the surface protective film described in 10. 12. The electronic component described in 11, which is a power module.

According to the present invention, there can be provided a resin composition capable of forming a cured product having suppressed discoloration of appearance after curing and after an autoclave test, a method for producing the cured product, the cured product, a covering coating, a surface protective film, and an electronic component.

The resin composition, the method for producing the cured product, the cured product, the coating, the surface protection film, and the electronic component of the present invention are described in detail below. The present invention is not limited to the following embodiments.

In this specification, "A or B" may include either A or B, or both. In addition, in this specification, the term "step" includes not only independent steps, but also steps that achieve the desired effect of the step even if they cannot be clearly distinguished from other steps. The numerical range represented by "~" indicates a range that includes the numerical values recorded before and after "~" as the minimum and maximum values, respectively. In addition, in this specification, when there are multiple substances equivalent to each component in the composition, unless otherwise specified, the content of each component in the composition refers to the total amount of the multiple substances in the composition. Furthermore, unless otherwise specified, the exemplified materials may be used alone or in combination of two or more.

The resin composition of the present invention comprises: (A) a polyimide precursor having a structural unit represented by the following formula (1) (hereinafter, also referred to as "component (A)"); and (C) one or more selected from the group consisting of an antioxidant and a compound having a structure represented by the following formula (21) (hereinafter, also referred to as "component (C)"). [Chemistry 5] (In formula (1), _X1 is a tetravalent group having one or more aromatic groups, _-COOR1 and -CONH- are adjacent to each other, and _-COOR2 and -CO- are adjacent to each other. _Y1 is a divalent organic group. _R1 and _R2 are independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.) [Chemistry 6]

This makes it possible to form a cured product that suppresses discoloration of the appearance after curing and after the autoclave test. As an additional effect, a cured product with excellent adhesion (for example, adhesion to Cu) can be formed.

In the tetravalent group having one or more (preferably one to three, more preferably one or two) aromatic groups represented by _X1 in formula (1), the aromatic group may be an aromatic alkyl group or an aromatic heterocyclic group. An aromatic alkyl group is preferred.

Examples of the aromatic hydrocarbon group represented by X ₁ in the formula (1) include a divalent to tetravalent (divalent, trivalent or tetravalent) group formed from a benzene ring, a divalent to tetravalent group formed from naphthalene, and a divalent to tetravalent group formed from perylene.

Examples of the tetravalent group having one or more aromatic groups as _X1 in formula (1) include, but are not limited to, the tetravalent groups of formula (6) below. (In formula (6), X and Y each independently represent a divalent group or a single bond that is not conjugated to the benzene ring to which they are bonded. Z is a carbonyl group (-C(=O)-), an ether group (-O-) or a sulfide group (-S-) (preferably -C(=O)-).)

In formula (6), the divalent group of X and Y that is not conjugated to the benzene ring to which each is bonded is preferably -O-, -S-, methylene, bis(trifluoromethyl)methylene, or difluoromethylene, and more preferably -O-.

Examples of the divalent organic group represented by _Y1 in formula (1) include a divalent group having a disiloxane structure, a divalent aliphatic hydrocarbon group, and a divalent aromatic group.

Preferably, the divalent group having a disiloxane structure further includes (preferably two or more, more preferably two) divalent aliphatic hydrocarbon groups. The divalent group having a disiloxane structure may have a substituent. Examples of the substituent of the divalent group having a disiloxane structure include a methyl group, an ethyl group, and the like.

The divalent aromatic group represented by _Y1 in formula (1) may be a divalent aromatic alkyl group or a divalent aromatic heterocyclic group. Preferably, it is a divalent aromatic alkyl group.

In addition, the divalent organic group of _Y1 in formula (1) may be a divalent group formed by two divalent aromatic hydrocarbon groups bonded by a single bond; a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, and a silicon atom; a divalent aliphatic hydrocarbon group; or an organic group such as a ketone group, an ester group, and an amide group.

Regarding the divalent organic group represented by _Y1 in formula (1), the divalent aliphatic alkyl group and the divalent aromatic alkyl group may have a substituent. Examples of the substituents of the divalent aliphatic alkyl group and the divalent aromatic alkyl group include a methyl group, an ethyl group, and an amide group (e.g., -C(=O) _-NH2 ).

Regarding the divalent organic group represented by _Y1 in formula (1), the divalent aliphatic hydrocarbon group (preferably having 1 to 30 carbon atoms, more preferably 1 to 5 or 5 to 18 carbon atoms) includes, for example, an alkylene group (e.g., a methylene group, an ethylene group, a propylene group, a decenyl group, a dodecenyl group), a cyclopentylene group, a cyclohexylene group, a cyclooctylene group, and a divalent bicyclic ring.

In addition, as for the divalent organic group represented by Y ₁ in formula (1), examples of the divalent aromatic hydrocarbon group (preferably having 6 to 30 carbon atoms) include phenylene groups (e.g., m-phenylene and p-phenylene groups) and naphthylene groups.

_R1 and _R2 in formula (1) are preferably hydrogen atoms.

Examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms (preferably 1 or 2 carbon atoms) for _R1 and _R2 in formula (1) include methyl, ethyl, n-propyl, 2-propyl, n-butyl and the like.

Regarding the molecular weight of component (A), the weight average molecular weight converted to polystyrene is preferably 10,000 to 200,000, more preferably 15,000 to 150,000, and further preferably 17,000 to 120,000. In the case of the above range, the viscosity of the resin composition can be made appropriate. The weight average molecular weight is determined by measuring by gel permeation chromatography and converting using a standard polystyrene calibration curve. In addition, the dispersion obtained by dividing the weight average molecular weight by the number average molecular weight is preferably 1.0 to 4.0, and more preferably 1.0 to 3.5.

The resin composition of the present invention contains the component (C), thereby suppressing the oxidation of copper.

From the viewpoint of inhibiting the oxidation of copper, the antioxidant is preferably a compound having a structure represented by the following formula (11). (In formula (11), R ₁₁ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms.)

From the viewpoint of adhesion to copper, the antioxidant is preferably a compound represented by the following formula (12). (In formula (12), R ₁₁ is a hydrogen atom, an aliphatic alkyl group having 1 to 10 carbon atoms, or an aromatic alkyl group having 6 to 30 carbon atoms. R ₁₂ is an aliphatic alkyl group having 1 to 10 carbon atoms, or an aromatic alkyl group having 6 to 30 carbon atoms. When there are two or more R ₁₂ , the two or more R ₁₂ may be the same or different. n is an integer of 0 to 3 (preferably 1 or 2).)

From the viewpoint of improving adhesion to copper, R ₁₁ is preferably a hydrogen atom.

Regarding R ₁₁ in formula (11) and formula (12), and regarding R ₁₂ in formula (12), examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms (preferably 1 or 2, and more preferably 3 or 4) include methyl, ethyl, n-propyl, 2-propyl, n-butyl, and tert-butyl.

Regarding R ₁₁ in the formula (11) and the formula (12), and regarding R ₁₂ in the formula (12), examples of the aromatic hydrocarbon group having 6 to 30 (preferably 6 to 10) carbon atoms include phenyl and naphthyl.

From the viewpoint of suppressing copper oxidation, the compound having a structure represented by formula (11) is preferably a compound having two or more (preferably two to four, more preferably two) structures represented by formula (11).

The compound having the structure represented by formula (21) is preferably a compound having two or more (preferably two to four, more preferably two) structures represented by formula (21). The compound having the structure represented by formula (21) is preferably a compound having the structure represented by the following formula (22). [Chemical 10] (In formula (22), _R21 is a divalent aliphatic hydrocarbon group.)

Examples of the divalent aliphatic hydrocarbon group for R ₂₁ in the formula (22) include the same groups as the divalent aliphatic hydrocarbon group for the divalent organic group for Y ₁ in the formula (1).

Examples of the compound having the structure represented by formula (21) include dodecanedioic acid bis[N2-(2-hydroxybenzoyl)hydrazide] and the like.

The component (C) may be used alone or in combination of two or more.

The content of the component (C) is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and further preferably 0.3 to 11 parts by mass, based on 100 parts by mass of the component (A).

The resin composition of the present invention may also contain (B) one or more selected from the group consisting of compounds containing a triazole structure and compounds containing a tetrazole structure (hereinafter also referred to as "component (B)"). This can further suppress the oxidation of copper.

From the viewpoint of suppressing oxidation by reacting with the copper surface at low temperature, the component (B) is preferably a compound containing a tetrazole structure (a 5-membered aromatic heterocyclic structure containing one carbon atom and four nitrogen atoms). As compounds containing a tetrazole structure, there can be listed: 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 1H-tetrazole, 5-(methylthio)-1H-tetrazole, 5-(ethylthio)-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-nitro-1H-tetrazole, 1-methyl-1H-tetrazole, 5,5'-bis-1H-tetrazole, etc. From the viewpoint of storage stability (for example, inhibition of the reaction of component (A) at room temperature), the compound containing a tetrazole structure is preferably one or more selected from the group consisting of 5-amino-1H-tetrazole and 5-methyl-1H-tetrazole.

The component (B) preferably contains a compound containing a triazole structure (a 5-membered aromatic heterocyclic structure containing two carbon atoms and three nitrogen atoms) and a compound containing a tetrazole structure.

Examples of the compound containing a triazole structure include benzotriazole (e.g., 1,2,3-benzotriazole), 1,2,4-triazole, 1,2,3-triazole, 1,2,5-triazole, 3-ol-4-methyl-4H-1,2,4-triazole, 3-ol-1,2,4-triazole, 4-amino-3,5-dimethyl-4H-1,2,4-triazole, 4-amino-3,5-dipropyl-4H-1,2,4-triazole, 3-amino-5-isopropyl-1,2,4-triazole, 4-amino-3-ol-5-methyl- 4H-1,2,4-triazole, 3-amino-5-methyl-1,2,4-triazole, 3-amino-5-methyl-4H-1,2,4-triazole, 4-amino-1,2,4-triazole, 4-amino-3,5-dimethyl-1,2,4-triazole, 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol, 3,5-diamino-1H-1,2,4-triazole, 5-methyl-1H-benzotriazole, 5,6-dimethylbenzotriazole, 5-amino-1H-benzotriazole, benzotriazole-4-sulfonic acid, etc. From the viewpoint of being less likely to decompose and volatilize when heated at high temperatures, the compound containing a triazole structure is preferably benzotriazole.

The component (B) may be used alone or in combination of two or more.

The content of the component (B) is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and further preferably 0.3 to 4 parts by mass, based on 100 parts by mass of the component (A).

The resin composition of the present invention may further contain a solvent.

As the solvent, there is no particular limitation as long as it can fully dissolve other components. Examples include: N-methyl-2-pyrrolidone, γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N,N-dimethylformamide, N,N-dimethylacetamide, hexamethylphosphatamide, tetramethylene sulfone, cyclohexanone, cyclopentanone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, etc. Among them, from the viewpoint of solubility of each component and the viewpoint of coating properties, N-methyl-2-pyrrolidone, γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, N,N-dimethylformamide, and N,N-dimethylacetamide are preferred.

The solvent may be a single type or a combination of two or more types.

The content of the solvent is not particularly limited, but is usually 1 to 1000 parts by mass, preferably 50 to 600 parts by mass, and more preferably 100 to 500 parts by mass, based on 100 parts by mass of the component (A).

The resin composition of the present invention may also contain an amine compound having an acryl group or a methacryl group as a crosslinking agent.

Examples of the amine compound having an acryl group or a methacryl group include, but are not limited to, N,N-diethylaminopropyl methacrylate, N,N-dimethylaminopropyl methacrylate, N,N-diethylaminopropyl acrylate, and N,N-diethylaminoethyl methacrylate.

In the case of imparting negative photosensitivity to the resin composition of the present invention, it is generally preferred to further contain a photopolymerization initiator such as a free radical polymerization initiator. In this way, negative photosensitivity can be imparted to the resin composition. The photopolymerization initiator is preferably in an amount of 0.1 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and further preferably 0.2 to 10 parts by mass, relative to 100 parts by mass of component (A).

In addition, the resin composition of the present invention may also contain other components such as an adhesion promoter and an acid generator as needed within a range that does not impair the heat resistance and mechanical properties.

The resin composition of the present invention is essentially composed of (A) component and (C) component, and any (B) component, a crosslinking agent, a photopolymerization initiator, a bonding aid, and an acid generator, in addition to the solvent, and may contain other inevitable impurities within the range that does not impair the effect of the present invention. In addition to the solvent, the resin composition of the present invention may be composed of, for example, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 100% by mass (A) component and (C) component; or (A) component and (C) component, and any (B) component, a crosslinking agent, a photopolymerization initiator, a bonding aid, and an acid generator.

The cured product of the present invention can be obtained by curing the resin composition. The film thickness of the cured product of the present invention is preferably 5 μm to 30 μm.

The method for manufacturing the hardened product of the present invention may include: applying the resin composition on a substrate and drying it to form a resin film; and heating the resin film. Furthermore, it may also include an exposure (for example, non-patterned) step. Thereby, the hardened product of the present invention can be obtained.

As the substrate, there can be listed: glass substrate; semiconductor substrates such as silicon carbide substrate, lithium tantalum substrate, lithium niobate substrate, Si substrate (silicon wafer); metal oxide insulator substrates such as _TiO2 substrate, _SiO2 substrate; Cu-plated wafer, silicon nitride substrate (for example, SiN layer formed wafer), aluminum substrate, copper substrate, copper alloy substrate, etc.

The coating method is not particularly limited, and the coating can be performed using a spinner or the like.

Drying can be performed using a heating plate, an oven, etc. The drying temperature is preferably 90°C to 150°C, and more preferably 90°C to 120°C from the perspective of the flatness of the coating film. The drying time is preferably 30 seconds to 5 minutes. Drying can also be performed twice or more. In this way, a resin film can be obtained in which the resin composition is formed into a film.

The thickness of the resin film is preferably 5 μm to 100 μm, more preferably 8 μm to 50 μm, and further preferably 10 μm to 30 μm.

In the exposure step, the actinic radiation irradiated may include broadband light (wavelength 350 nm to 450 nm), ultraviolet light such as i-ray, visible light, radiation, etc., preferably i-ray. As the exposure device, a parallel exposure machine, a projection exposure machine, a stepper, a scanning exposure machine, a proximity exposure machine, etc. can be used.

By heat-treating the resin film, a hardened material can be obtained. The polyimide precursor of component (A) can undergo a dehydration and ring-closing reaction by the heat treatment step, thereby becoming the corresponding polyimide.

The temperature of the heat treatment is preferably below 400°C, and more preferably 180°C to 370°C. By keeping the temperature within the above range, damage to the substrate or device can be minimized, devices can be produced with good yield, and energy saving of the process can be achieved.

The heat treatment time is preferably less than 5 hours, more preferably 30 minutes to 3 hours. By being within the above range, the crosslinking reaction or dehydration and ring closing reaction can be fully carried out. The heat treatment environment can be in the atmosphere or in an inert environment such as nitrogen, but from the perspective of preventing oxidation of the resin film, it is preferably in a nitrogen environment.

As the apparatus used in the heat treatment, there can be listed: a quartz tube furnace, a heating plate, a rapid annealing furnace, a vertical diffusion furnace, an infrared hardening furnace, an electron beam hardening furnace, a microwave hardening furnace, etc.

The cured product of the present invention can be used as a passivation film, a buffer coating, a cover coating, or a surface protective film. Using one or more selected from the group consisting of the passivation film, the buffer coating, the cover coating, and the surface protective film, it is possible to manufacture highly reliable semiconductor devices, multi-layer wiring boards, various electronic devices, power modules, and other electronic parts. [Example]

Hereinafter, the present invention will be described in more detail based on embodiments and comparative examples. Furthermore, the present invention is not limited to the following embodiments.

Synthesis Example 1 (Synthesis of A1) In a 200 ml flask under a nitrogen atmosphere, 13.0 g of 4,4'-oxydiphenylamine, 0.9 g of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, and 140 g of N-methyl-2-pyrrolidone (NMP) were placed and stirred at room temperature for 15 minutes to dissolve the monomers. Then, 7.8 g of pyromellitic dianhydride (PMDA) and 11.5 g of 3,3',4,4'-benzophenonetetracarboxylic dianhydride were added and stirred for further 60 minutes to obtain polyimide precursor A1. The weight average molecular weight was calculated by using the gel permeation chromatograph (GPC) method under the following conditions and by conversion to standard polystyrene. The weight average molecular weight of A1 is 106,000.

The measurement was performed using 1 mL of a solution of a solvent [tetrahydrofuran (THF)/dimethylformamide (DMF) = 1/1 (volume ratio)] relative to 0.5 mg of A1.

Measurement equipment: Detector: L4000UV manufactured by Hitachi, Ltd. Pump: L6000 manufactured by Hitachi, Ltd. Chromatopac C-R4A manufactured by Shimadzu Corporation Measurement conditions: Column Gelpack GL-S300MDT-5 × 2 roots Eluent: THF/DMF = 1/1 (volume ratio) LiBr (0.03 mol/L), H ₃ PO ₄ (0.06 mol/L) Flow rate: 1.0 mL/min, Detector: UV 270 nm

Synthesis Example 2 (Synthesis of A2) In a 200 ml flask under a nitrogen atmosphere, 4.0 g of 4,4'-oxydiphenylamine, 2.2 g of m-phenylenediamine, and 164 g of NMP were placed, and heated and stirred at 40°C for 15 minutes to dissolve the monomers. Then, 13.0 g of 3,3',4,4'-benzophenonetetracarboxylic dianhydride was added, and further stirred for 30 minutes to obtain polyimide precursor A2. The weight average molecular weight was determined using the GPC method under the same conditions as in Synthesis Example 1. The weight average molecular weight of A2 was 50,000.

Example 1 to Example 8 and Comparative Example 1 to Comparative Example 2 (Preparation of resin composition) The resin compositions of Example 1 to Example 8 and Comparative Example 1 to Comparative Example 2 were prepared according to the components and blending amounts shown in Table 1 and Table 2. The blending amounts in Table 1 and Table 2 are the mass parts of each component relative to 100 mass parts of A1.

The components used are as follows.

(A) Components A1: A1 obtained in Synthesis Example 1 A2: A2 obtained in Synthesis Example 2

(C) Component C1: 4-methyl-2-tert-butylphenol (manufactured by Honshu Chemical Industry Co., Ltd.) C2: 3-methyl-6-tert-butylphenol (manufactured by Honshu Chemical Industry Co., Ltd.) C3: 3,5-di-tert-butyl-4-hydroxytoluene (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) C4: ANTAGE HP-300 (manufactured by Kawaguchi Chemical Industry Co., Ltd., N,N'-bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionylhexamethylenediamine, a compound represented by the following formula C4) [Chemical 11] C5: CDA-6 (manufactured by ADEKA Co., Ltd., dodecanedioic acid bis[N2-(2-hydroxybenzoyl)hydrazide], a compound represented by the following formula C5) [Chemical 12]

Solvent NMP: N-methyl-2-pyrrolidone

(Production of hardened product) The obtained resin composition was spin-coated on a Cu-plated wafer (Si wafer with a Cu-plated layer of 0.5 μm thickness) using a coating device Act8 (manufactured by Tokyo Electron Co., Ltd.) so that the film thickness after hardening was 10 μm, and then dried at 100°C for 2 minutes and then at 110°C for 2 minutes to form a resin film. Then, the obtained resin film was heated at 250°C for 2 hours in a nitrogen atmosphere using a vertical diffusion furnace μ-TF (manufactured by Koyo Thermo Systems Co., Ltd.) to obtain a hardened product (film thickness after hardening was 10 μm).

(PCT) The hardened material obtained in the production of the hardened material was treated for 168 hours at 121°C, 100% relative humidity (RH), and 2 atm using a pressure cooker test (PCT) test device HASTEST (manufactured by Hirayama Seisakusho Co., Ltd., PC-R8D). The hardened material was taken out from the PCT test device to obtain a hardened material after PCT.

(Appearance evaluation) The appearance of the hardened product and the hardened product after PCT was evaluated visually. The color of the resin film on the Cu-plated wafer that was spin-coated and dried at 110°C for 2 minutes during the production of the hardened product was evaluated as 0. The color that changed to yellow-green was evaluated as △. The color that changed to black was evaluated as ×. The results are shown in Tables 1 and 2. In the table, "-" means not measured.

(Cu Adhesion Evaluation) Regarding the hardened material and the hardened material after PCT, the adhesion of these hardened materials to the Cu-plated wafer was evaluated based on the crosscut method of Japanese Industrial Standards (JIS) K 5600-5-6 and the following criteria. Specifically, the number of grids of the hardened material adhering to the Cu-plated wafer in a 10×10 grid was evaluated. The results are shown in Tables 1 and 2. In the table, "-" means not measured. "◎": The number of grids of the hardened material bonded to the Cu-plated wafer is 100 "0": The number of grids of the hardened material bonded to the Cu-plated wafer is 80 to 99 "△": The number of grids of the hardened material bonded to the Cu-plated wafer is 50 to 79 "×": The number of grids of the hardened material bonded to the Cu-plated wafer is 20 to 49 "××": The number of grids of the hardened material bonded to the Cu-plated wafer is less than 20

[Table 1] Embodiment 1 Embodiment 2 Embodiment 3 Embodiment 4 Embodiment 5 Embodiment 6 Comparison Example 1 (A) Ingredients A1 100 100 100 100 100 100 100 A2 - - - - - - - (C) Ingredients C1 5 - - - - - - C2 - 5 - - - - - C3 - - 10 - - - - C4 - - - 5 10 - - C5 - - - - - 0.25 - Solvent NMP 430 430 430 430 430 430 430 Appearance evaluation After hardening ○ ○ ○ △ ○ △ × Post-PCT ○ ○ ○ △ ○ △ × Cu Adhesion Evaluation After hardening △ ○ △ ○ ○ △ ×× Post-PCT ◎ ◎ × △ ○ × ××

[Table 2] Embodiment 7 Embodiment 8 Comparison Example 2 (A) Ingredients A1 - - - A2 100 100 100 (C) Ingredients C1 5 - - C2 - - - C3 - - - C4 - 10 - C5 - - - Solvent NMP 300 300 300 Appearance evaluation After hardening ○ ○ × Post-PCT ○ ○ × Cu Adhesion Evaluation After hardening △ △ ○ Post-PCT ◎ ◎ ×× [Industrial Availability]

The resin composition of the present invention can be used for a covering coating or a surface protective film, and the covering coating or the surface protective film of the present invention can be used for electronic parts, etc. The electronic parts of the present invention can be used as a power module, etc.

In the above, several embodiments and/or examples of the present invention are described in detail, but it is easy for a person skilled in the art to make various changes to the embodiments and/or examples as examples without substantially deviating from the novel teachings and effects of the present invention. Therefore, these various changes are included in the scope of the present invention. The entire contents of the documents described in the specification and the application that is the basis for the priority of this application under the Paris Treaty are cited.

without

without

Claims (13)

A resin composition comprising: (A) a polyimide precursor having a structural unit represented by the following formula (1); and (C) a compound represented by the following formula (12),

(In formula (1), _X1 is a tetravalent group having one or more aromatic groups, _-COOR1 and -CONH- are adjacent to each other, _-COOR2 and -CO- are adjacent to each other; _Y1 is a divalent organic group; _R1 and _R2 are independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms)

(In formula (12), R ₁₁ is a hydrogen atom; R ₁₂ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms; when there are two or more R _12s , the two or more R _12s may be the same or different; and n is an integer of 0 to 3). The resin composition as described in claim 1, wherein R ₁ and R ₂ are hydrogen atoms. The resin composition according to claim 1, wherein _X1 is a tetravalent group having the following formula (6):

(In formula (6), X and Y each independently represent a divalent group or a single bond that is not conjugated to the benzene ring to which they are bonded; and Z is a carbonyl group, an ether group or a thioether group). The resin composition as described in claim 1, wherein R ₁₂ is methyl, ethyl, n-propyl, 2-propyl, n-butyl or t-butyl. The resin composition according to claim 1, wherein R ₁₂ is a methyl group. The resin composition as described in claim 1, wherein n is 1 or 2. The resin composition as described in any one of claim 1 to claim 6 further comprises a solvent. A method for manufacturing a hardened product, comprising: applying the resin composition described in any one of claim 1 to claim 7 on a substrate and drying it to form a resin film; and heating the resin film. A hardened material obtained by hardening the resin composition described in any one of claim 1 to claim 7. A covering coating made using the hardener described in claim 9. A surface protective film made using the hardened material as described in claim 9. An electronic component comprising a covering coating as described in claim 10 or a surface protection film as described in claim 11. The electronic component as described in claim 12 is a power module.