JP7211560B2 - Photosensitive resin composition - Google Patents

Description

The present invention relates to a photosensitive resin composition.

Until now, in the field of photosensitive resin compositions, various techniques have been developed in an attempt to obtain a photosensitive resin composition that can form a cured film that is not brittle and has excellent heat resistance even when cured at a low temperature. . As this type of technology, the technology described in Patent Document 1 can be cited.
Patent Document 1 describes that a film obtained by applying a resin composition containing a compound having a phenolic hydroxyl group to a polyamide having a specific structure and curing at 200° C. or less exhibits a high elongation at break. (Paragraph 0008).

Japanese Unexamined Patent Application Publication No. 2007-213032

When the present inventor examined the technique described in Patent Document 1, it became clear that there is still room for improvement in terms of obtaining a film having excellent curability at low temperatures.

The present invention provides a resin film having excellent curability at low temperatures.

According to the invention,
Component (A): A photosensitive resin composition containing an alkali-soluble resin,
The component (A) contains component (a1): a biphenylaralkyl-type phenolic resin,
Provided is a photosensitive resin composition in which a cured film of the photosensitive resin composition has a tensile elongation of 10% or more and 200% or less, measured under Condition 1 below.
(Condition 1)
(i) The photosensitive resin composition is cured at 200° C. for 180 minutes to form the cured film, and a sample of 6.5 mm×20 mm×10 μm thick is prepared from the cured film.
(ii) Based on JIS K7161, a tensile test is performed on the sample under conditions of 23° C. and a test speed of 5 mm/min to determine the tensile elongation.

Further, according to the present invention, it is also possible to provide a resin film obtained by curing the photosensitive resin composition of the present invention, and an electronic device comprising the resin film.

ADVANTAGE OF THE INVENTION According to this invention, the resin film which is excellent in curability at low temperature can be provided.

1 is a cross-sectional view showing a configuration example of an electronic device according to an embodiment; FIG.

Hereinafter, embodiments of the present invention will be described with specific examples of each component. In the following embodiments, the composition can contain each component alone or in combination of two or more.
In this specification, the numerical range "x to y" represents "x or more and y or less" and includes both the lower limit value x and the upper limit value y. Further, in the drawings below, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Also, the drawings are schematic diagrams and do not correspond to actual dimensional ratios.

(Photosensitive resin composition)
In this embodiment, the photosensitive resin composition contains component (A): an alkali-soluble resin, and component (A) contains component (a1): a biphenylaralkyl-type phenolic resin. The tensile elongation of the cured film of the photosensitive resin composition measured under Condition 1 below is 10% or more and 200% or less.
(Condition 1)
(i) The photosensitive resin composition is cured at 200° C. for 180 minutes to form a cured film, and a sample of 6.5 mm×20 mm×10 μm thick is prepared from the cured film.
(ii) Based on JIS K7161, a tensile test is performed on the sample under conditions of 23° C. and a test speed of 5 mm/min to determine the tensile elongation.

The present inventor conducted studies to improve the low-temperature curability of the photosensitive resin composition. As a result, the above problems are solved by configuring the photosensitive resin composition to contain a specific component and having a tensile elongation percentage of the cured film of the photosensitive resin composition within a specific range. I found out.

The tensile elongation of the cured film is 10% or more, preferably 20% or more, more preferably 30% or more, and still more preferably 40% or more, from the viewpoint of suppressing brittle fracture.
Further, from the viewpoint of obtaining a cured film more stably, the tensile elongation of the cured film is 200% or less, preferably 150% or less, more preferably 125% or less, still more preferably 100% or less, and even more preferably. is 90% or less.

In the present embodiment, the glass transition temperature (Tg) of the cured product of the photosensitive resin composition is preferably 150° C. or higher, more preferably 180° C. or higher, and still more preferably 200° C. or higher, from the viewpoint of improving heat resistance. , and more preferably 210° C. or higher.
Moreover, from the viewpoint of suppressing deterioration of brittleness, the glass transition temperature of the cured product of the photosensitive resin composition is preferably 260° C. or lower, more preferably 240° C. or lower, and still more preferably 230° C. or lower.

Here, the Tg of the cured product of the photosensitive resin composition is measured using a thermomechanical analyzer (TMA) for a predetermined test piece (width 3 mm × length 10 mm × thickness 0.005 to 0.015 mm). , a starting temperature of 30° C., a measurement temperature range of 30 to 440° C., and a heating rate of 10° C./min.

From the viewpoint of improving the reliability of the cured product of the photosensitive resin composition, the film strength of the cured film measured under Condition 2 below is preferably 70 MPa or more, more preferably 90 Pa or more, and still more preferably 100 MPa or more. , and more preferably 105 MPa or more.
From the viewpoint of suppressing brittle fracture, the film strength of the cured film is preferably 150 MPa or less, more preferably 140 MPa or less, still more preferably 130 MPa or less, and even more preferably 120 MPa or less.
(Condition 2)
Apparatus: Tensile/compression tester Temperature: Normal temperature (25°C)
Tensile speed: 5mm/min
Specimen size: 6.5 mm x 20 mm x 10 µm thickness

Further, from the viewpoint of improving the reliability of the cured product of the photosensitive resin composition, the linear expansion coefficient of the cured film in the temperature range of 50 to 100° C. is preferably 25 ppm/° C. or more, more preferably 30 ppm/° C. Above, more preferably 35 ppm/°C or more, and preferably 40 ppm/°C or less.
Here, the linear expansion coefficient of the cured film in the temperature range of 50 to 100 ° C. is specifically, a test piece of the cured film obtained under the conditions of 200 ° C. and 180 minutes (width 3 mm × length 10 mm × thickness 10 mm ) was measured using a thermomechanical analyzer (TMA) under the conditions of a starting temperature of 30° C., a measurement temperature range of 30 to 440° C., and a heating rate of 10° C./min.

Next, each component will be described in more detail.
(Component (A))
Component (A) is an alkali-soluble resin and includes component (a1): a biphenylaralkyl-type phenolic resin.

Component (a1) is preferably represented by the following general formula (2) from the viewpoint of improving curability at low temperatures.

In general formula (2), n is preferably 6 or more, more preferably 10 or more, even more preferably 12 or more, and even more preferably 14 or more, from the viewpoint of improving curability at low temperatures.
From the viewpoint of solvent solubility, n is preferably 72 or less, more preferably 54 or less, and even more preferably 36 or less.

The weight average molecular weight of component (a1) may be, for example, 500 or more, preferably 2,000 or more, more preferably 3,000 or more, and still more preferably 4,000 or more, from the viewpoint of improving curability at low temperatures.
In addition, the weight average molecular weight of component (a1) may be, for example, 50,000 or less, preferably 20,000 or less, more preferably 15,000 or less, even more preferably 10,000 or less, still more preferably from the viewpoint of solvent solubility. 8000 or less.
Here, the weight average molecular weight of component (a1) is specifically measured by gel permeation chromatography (GPC) and calculated based on a calibration curve prepared using polystyrene standard substances.

The content of the component (a1) in the photosensitive resin composition is preferably 5 parts by mass or more from the viewpoint of improving the toughness during low-temperature curing when the total solid content of the photosensitive resin composition is 100 parts by mass. Yes, more preferably 10 parts by mass or more, still more preferably 15 parts by mass or more.
Further, from the viewpoint of deterioration of thermomechanical properties, the content of component (a1) in the photosensitive resin composition is preferably 70 parts by mass or less when the total solid content of the photosensitive resin composition is 100 parts by mass. Yes, more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

In addition, component (A) may contain components other than component (a1). Specific examples of such resins include one or more selected from the group consisting of phenol resins, hydroxystyrene resins, polyamide resins, polybenzoxazole resins, polyimide resins, and cyclic olefin resins other than component (a1).

Component (A) preferably further contains component (a2): a phenolic resin other than component (a1) from the viewpoint of improving the curability at low temperature and the reliability of the cured film.
Specific examples of component (a2) include novolak-type phenolic resins such as phenol novolak resin, cresol novolak resin, bisphenol novolak resin, phenol-biphenyl novolak resin, allylated novolak-type phenol resin, and xylylene novolak-type phenol resin; one or two selected from the group consisting of reactants of phenolic compounds such as phenolic resins, resol-type phenolic resins, and cresol novolak resins with aldehyde compounds; and reactants of phenolic compounds such as phenol aralkyl resins with dimethanol compounds. Includes more than one species. Component (a2) is preferably a novolak-type phenolic resin.

Moreover, the component (a2) preferably has a structural unit represented by the following general formula (4) from the viewpoint of improving the curability at low temperatures and the reliability of the cured film.

(In general formula (4) above, R ₄₁ and R ₄₂ each independently represent a hydroxyl group, a halogen atom, a carboxyl group, a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, a A monovalent substituent selected from the group consisting of an alkyl ether group, a saturated or unsaturated alicyclic group having 3 to 20 carbon atoms, or an organic group having an aromatic structure having 6 to 20 carbon atoms, may be bonded via an ester bond, an ether bond, an amide bond or a carbonyl bond, r and s are each independently an integer of 0 to 3, and Y ₄ and Z ₄ are each independently and an aliphatic group having 1 to 10 carbon atoms which may have a single bond or an unsaturated bond, an alicyclic group having 3 to 20 carbon atoms, and an aromatic structure having 6 to 20 carbon atoms. Selected from the group consisting of organic groups, Z ₄ is attached to either one of the two benzene rings.)

A phenol resin having a structural unit represented by general formula (4) can be specifically obtained using the method described in JP-A-2018-155938.

The content of the component (a2) in the photosensitive resin composition is preferably 5 parts by mass or more from the viewpoint of improving curability during low-temperature curing when the total solid content of the photosensitive resin composition is 100 parts by mass. , more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more.
Further, from the viewpoint of deterioration of toughness, the content of the component (a2) in the photosensitive resin composition is preferably 70 parts by mass or less when the total solid content of the photosensitive resin composition is 100 parts by mass. It is more preferably 60 parts by mass or less, still more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

Further, the content of the component (A) in the photosensitive resin composition is, when the total solid content of the photosensitive resin composition is 100 parts by mass, from the viewpoint of improving the curability at low temperatures and the reliability of the cured film. Therefore, it is preferably 30 parts by mass or more, more preferably 45 parts by mass or more, still more preferably 50 parts by mass or more, and may be, for example, 55 parts by mass or more.
Further, from the viewpoint of improving chemical resistance and photosensitivity, the content of component (A) in the photosensitive resin composition is preferably 95 parts by mass when the total solid content of the photosensitive resin composition is 100 parts by mass. parts or less, more preferably 90 parts by mass or less, still more preferably 85 parts by mass or less, and even more preferably 70 parts by mass or less.

(Component (B))
From the viewpoint of improving the reliability and chemical resistance of the cured film, the photosensitive resin composition preferably further contains component (B): a cross-linking agent.
Component (B) is specifically a compound having a group capable of reacting with component (A) by heat. dimethanol (paraxylene glycol), 1,3,5-benzenetrimethanol, 4,4-biphenyldimethanol, 2,6-pyridinedimethanol, 2,6-bis(hydroxymethyl)-p-cresol, 4, compounds having a methylol group such as 4′-methylenebis(2,6-dialkoxymethylphenol); phenols such as phloroglucide; 1,4-bis(methoxymethyl)benzene, 1,3-bis(methoxymethyl)benzene, 4,4'-bis(methoxymethyl)biphenyl, 3,4'-bis(methoxymethyl)biphenyl, 3,3'-bis(methoxymethyl)biphenyl, methyl 2,6-naphthalenedicarboxylate, 4,4'- compounds having an alkoxymethyl group such as methylenebis(2,6-dimethoxymethylphenol); methylolmelamine compounds represented by hexamethylolmelamine, hexabutanolmelamine, etc.; alkoxymelamine compounds such as hexamethoxymelamine; tetramethoxymethylglycoluril, etc. alkoxymethyl glycol uril compounds of; methylol benzoguanamine compounds, methylol urea compounds such as dimethylol ethylene urea; alkylated urea resins; cyano compounds such as dicyanoaniline, dicyanophenol, cyanophenylsulfonic acid; isocyanate compounds such as 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate; ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, triglycidyl isocyanurate, phenoxy type epoxy resin, bisphenol A type epoxy resin, Epoxy group-containing compounds such as bisphenol F type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolac resin type epoxy resin; N,N'-1,3-phenylenedimaleimide, N,N'-methylenedimaleimide and maleimide compounds such as

From the viewpoint of improving the chemical resistance of the resin film obtained by curing the photosensitive resin composition, component (B) preferably contains component (b1): a bifunctional epoxy resin, more preferably bifunctional epoxy resin. Contains functional phenoxy-type epoxy resins. From the same point of view, it is also preferred that component (B) contains component (b1) and an alkylated urea resin. Phenoxy-type epoxy resins include bisphenol A-type phenoxy resin, bisphenol F-type phenoxy resin, bisphenol S-type phenoxy resin, bisphenolacetophenone-type phenoxy resin, novolac-type phenoxy resin, biphenyl-type phenoxy resin, fluorene-type phenoxy resin, and dicyclopentadiene-type phenoxy resin. Phenoxy resins, norbornene-type phenoxy resins, naphthalene-type phenoxy resins, anthracene-type phenoxy resins, adamantane-type phenoxy resins, terpene-type phenoxy resins, trimethylcyclohexane-type phenoxy resins, and the like can be used. Specific examples of commercially available phenoxyphenoxy-type epoxy resins include resins JER-1256, YX-7105 (manufactured by Mitsubishi Chemical Corporation) and LX-01 (manufactured by Osaka Soda Co., Ltd.).

The content of the component (b1) in the photosensitive resin composition is preferably 0.1 part by mass from the viewpoint of improving the toughness during low-temperature curing when the total solid content of the photosensitive resin composition is 100 parts by mass. or more, more preferably 1 part by mass or more, and still more preferably 3 parts by mass or more.
Further, from the viewpoint of maintaining the thermomechanical properties during low-temperature curing, the content of the component (b1) in the photosensitive resin composition is preferably It is 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

Further, the content of component (B) in the photosensitive resin composition is preferably It is 0.1 part by mass or more, more preferably 1 part by mass or more, and still more preferably 3 parts by mass or more.
Further, from the viewpoint of enhancing the chemical resistance of the cured film, the content of the component (B) in the photosensitive resin composition is preferably 60 parts by mass when the total solid content of the photosensitive resin composition is 100 parts by mass. or less, more preferably 50 parts by mass or less, and still more preferably 40 parts by mass or less.

(Component (C))
From the viewpoint of stably forming a cured film, the photosensitive resin composition preferably further contains component (C): an acid generator. Component (C) is specifically a compound that generates an acid by absorbing thermal energy or light energy.

From the viewpoint of improving low-temperature curability and chemical resistance, component (C) preferably contains component (c1): a sulfonium compound or a salt thereof.
Component (c1) is specifically a sulfonium salt having a sulfonium ion as the cation moiety. At this time, the anion portion of component (c1) is specifically boride ion, antimony ion, phosphorus ion or sulfonate ion such as trifluoromethanesulfonate ion. Boride ions or antimony ions are preferred, and boride ions are more preferred. These anions may have substituents.

Component (c1) preferably contains a sulfonium salt represented by the following general formula (1).

In general formula (1) above, R ¹ is a hydrogen atom or a monovalent organic group, preferably a hydrogen atom or an acyl group, more preferably an acyl group, from the viewpoint of improving reactivity at low temperatures. and more preferably a CH ₃ C(=O)- group.
R ² is a monovalent organic group, preferably a chain or branched hydrocarbon group or an optionally substituted benzyl group, more preferably a benzyl group, from the viewpoint of improving reactivity at low temperatures. is a benzyl group optionally substituted with an alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or a benzyl group in which the aromatic ring portion may be substituted with a methyl group is the base.
R ³ is a monovalent organic group, preferably a chain or branched hydrocarbon group, more preferably an alkyl group having 1 to 4 carbon atoms, from the viewpoint of improving reactivity at low temperatures. and more preferably a methyl group.

Other preferred examples of component (c1) include triphenylsulfonium salts such as triphenylsulfonium trifluoromethanesulfonate.
Component (c1) may also be a photoacid generator such as di(trifluoromethanesulfone)imide (4,8-di-n-butoxy-1-naphthyl)dibutylsulfonium.

The content of component (c1) in the photosensitive resin composition is preferably 0.005 mass from the viewpoint of improving the curability at low temperatures when the total solid content of the photosensitive resin composition is 100 parts by mass. parts or more, more preferably 0.01 parts by mass or more, and still more preferably 0.02 parts by mass or more.
Further, from the viewpoint of suppressing reliability deterioration, the content of component (C) in the photosensitive resin composition is preferably 5% by mass or less when the total solid content of the photosensitive resin composition is 100 parts by mass. , more preferably 4% by mass or less, more preferably 3% by mass or less, and for example 0.5 parts by mass or less, for example 0.2 parts by mass or less, or for example 0.1 parts by mass or less is also preferred.

(Component (D))
The photosensitive resin composition preferably further contains component (D): a silane coupling agent from the viewpoint of enhancing the adhesion of the cured film of the photosensitive resin composition to the substrate. Examples of silane coupling agents include epoxysilanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane; p-styryltrimethoxysilane and the like. 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane; 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, etc. (meth)acrylsilane; N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)- aminosilanes such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane; 3-mercaptopropylmethyldimethoxysilane, 3-mercapto mercaptosilanes such as propyltrimethoxysilane; sulfide-based silanes such as bis(triethoxypropyl)tetrasulfide; and isocyanate silanes such as 3-isocyanatopropyltriethoxysilane. From a similar point of view, component (D) is preferably at least one selected from the group consisting of epoxysilane and (meth)acrylsilane, more preferably 3-glycidoxypropyltrimethoxysilane and 3-methacrylsilane. at least one of roxypropyltrimethoxysilane; Further, as a specific example of component (D), a silicon compound having one or more groups selected from the group consisting of amino groups, amido groups and urea groups is reacted with an acid dianhydride or an acid anhydride. Silicon compounds obtained by are also included.

The content of the component (D) in the photosensitive resin composition is preferably 0.5 parts per 100 parts by mass of the component (A) from the viewpoint of achieving both adhesion and storage stability of the photosensitive resin composition. 1 part by mass or more, more preferably 1 part by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and even more preferably 5 parts by mass It is below the department.

The photosensitive resin composition may contain components other than those mentioned above. As such components, additives other than component (D), such as adhesion aids, surfactants, antioxidants, dissolution accelerators, fillers and sensitizers, may be added.

As an adhesion aid other than the component (D), from the viewpoint of improving the adhesion of the cured film of the photosensitive resin composition to metal, specifically, one selected from the group consisting of triazole compounds and imide compounds, or Two or more compounds are included. This can further increase the number of lone electron pairs derived from nitrogen atoms.

Among them, the triazole compound specifically includes mercaptotriazole, 4-amino-1,2,4-triazole, 4H-1,2,4-triazol-3-amine, 4-amino-3,5- Di-2-pyridyl-4H-1,2,4-triazole, 3-amino-5-methyl-4H-1,2,4-triazole, 4-methyl-4H-1,2,4-triazole-3- amines, 3,4-diamino-4H-1,2,4-triazole, 3,5-diamino-4H-1,2,4-triazole, 1,2,4-triazole-3,4,5-triamine, 3-pyridyl-4H-1,2,4-triazole, 4H-1,2,4-triazole-3-carboxamide, 3,5-diamino-4-methyl-1,2,4-triazole, 3-pyridyl- 1 or 2 or more compounds selected from the group consisting of 1,2,4-triazoles such as 4-methyl-1,2,4-triazole, 4-methyl-1,2,4-triazole-3-carboxamide mentioned.

The content of the adhesion aid in the photosensitive resin composition is preferably 0.05 parts by mass or more, more preferably 0.05 part by mass, based on 100 parts by mass of component (A), from the viewpoint of further improving adhesion. It is 1 part by mass or more, more preferably 1 part by mass or more, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

Specific examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, and the like. polyoxyethylene aryl ethers; nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; company), Megafac F171, Megafac F172, Megafac F173, Megafac F177, Megafac F444, Megafac F470, Megafac F471, Megafac F475, Megafac F482, Megafac F477 (manufactured by DIC), Florard FC-430, Florard FC-431, Novec FC4430, Novec FC4432 (manufactured by 3M Japan), Surflon S-381, Surflon S-382, Surflon S-383, Surflon S-393, Surflon SC-101, Surflon SC-102 , Surflon SC-103, Surflon SC-104, Surflon SC-105, Surflon SC-106, (manufactured by AGC Seimi Chemical Co., Ltd.) and other fluorine-based surfactants; Organosiloxane copolymer KP341 (Shin-Etsu (manufactured by Kagaku Kogyo Co., Ltd.); (meth)acrylic acid copolymer Polyflow No. 57 and 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

Among these, it is preferable to use a fluorine-based surfactant having a perfluoroalkyl group. Among the specific examples of the perfluoroalkyl group-containing fluorosurfactant, Megafac F171, Megafac F173, Megafac F444, Megafac F470, Megafac F471, Megafac F475, Megafac F482, and Megafac One or more selected from F477 (manufactured by DIC), Surflon S-381, Surflon S-383, Surflon S-393 (manufactured by AGC Seimi Chemical Co., Ltd.), Novec FC4430 and Novec FC4432 (manufactured by 3M Japan) is preferably used.

As the surfactant, a silicone-based surfactant (for example, polyether-modified dimethylsiloxane) can also be preferably used. Specific examples of silicone surfactants include SH series, SD series and ST series from Dow Corning Toray Co., Ltd., BYK series from BYK Chemie Japan, KP series from Shin-Etsu Chemical Co., Ltd., Disfoam from NOF CORPORATION ( (registered trademark) series, TSF series of Toshiba Silicone Co., Ltd., and the like.

The content of the surfactant in the photosensitive resin composition is, for example, 0.001 mass with respect to the entire photosensitive resin composition (including the solvent) from the viewpoint of improving the coatability and the uniformity of the coating film. % (10 ppm), preferably 1% by mass (10000 ppm) or less, more preferably 0.5% by mass (5000 ppm) or less, and still more preferably 0.1% by mass (1000 ppm) or less.

(Preparation of photosensitive resin composition)
The photosensitive resin composition is prepared by mixing and dissolving each component described above and, if necessary, other components in an organic solvent.
Further, in the present embodiment, the photosensitive resin composition is used in the form of varnish by dissolving the above components and, if necessary, other components in an organic solvent, for example.
Further, the photosensitive resin composition is prepared by pre-reacting the component (a1), the component (A) other than the component (a1), and other components as appropriate to obtain a pre-reacted resin, and then adding other components as appropriate, can also be used.

Examples of organic solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether. , propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, ethyl pyruvate and methyl-3- One or more solvents selected from the group consisting of methoxypropionate.

(resin film)
A resin film is obtained by curing the photosensitive resin composition in the present embodiment. Moreover, the resin film in this embodiment is a dried film or a cured film of a photosensitive resin composition. That is, the resin film is formed by drying or curing a photosensitive resin composition, preferably by effecting the photosensitive resin composition.
This resin film is used, for example, to form a resin film for electronic devices such as a permanent film and a resist. Among these, from the viewpoint of obtaining a resin film at a low temperature, the viewpoint of having excellent workability, and the viewpoint of obtaining a resin film having excellent reliability, it is preferably used for applications using a permanent film.
According to the present embodiment, for example, for a resin film obtained using a photosensitive resin composition, a film that is excellent in workability or reliability, which is required for making a resin film useful for producing an electronic device or the like It is also possible to obtain

The permanent film is composed of a resin film obtained by pre-baking, exposing and developing a photosensitive resin composition, patterning it into a desired shape, and post-baking it to cure it. Permanent films can be used as protective films for electronic devices such as buffer coat films, interlayer films such as insulating films for rewiring, and dam materials.
Moreover, the photosensitive resin composition is preferably used for a buffer coat film or an insulating film for wiring.

The resist is applied to the object to be masked by the resist by a method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., and the photosensitive resin composition is coated. It is composed of a resin film obtained by removing the solvent.

FIG. 1 is a cross-sectional view showing a configuration example of an electronic device having a resin film according to this embodiment.
The electronic device 100 shown in FIG. 1 can be an electronic device including the resin film. Specifically, one or more of the group consisting of the passivation film 32, the insulating layer 42, and the insulating layer 44 in the electronic device 100 can be made of a resin film. Here, the resin film is preferably the permanent film described above.

Electronic device 100 is, for example, a semiconductor chip. In this case, for example, a semiconductor package is obtained by mounting the electronic device 100 on the wiring substrate via the bumps 52 . The electronic device 100 includes a semiconductor substrate provided with semiconductor elements such as transistors, and a multilayer wiring layer (not shown) provided on the semiconductor substrate. An interlayer insulating film 30 and a top layer wiring 34 provided on the interlayer insulating film 30 are provided in the uppermost layer of the multilayer wiring layers. The uppermost layer wiring 34 is made of aluminum Al, for example. A passivation film 32 is provided on the interlayer insulating film 30 and the uppermost layer wiring 34 . A portion of the passivation film 32 is provided with an opening through which the uppermost layer wiring 34 is exposed.

A rewiring layer 40 is provided on the passivation film 32 . The rewiring layer 40 includes an insulating layer 42 provided on the passivation film 32, a rewiring 46 provided on the insulating layer 42, an insulating layer 44 provided on the insulating layer 42 and the rewiring 46, have An opening connected to the uppermost layer wiring 34 is formed in the insulating layer 42 . The rewiring 46 is formed on the insulating layer 42 and in openings provided in the insulating layer 42 and connected to the uppermost layer wiring 34 . The insulating layer 44 is provided with an opening connected to the rewiring 46 .

A bump 52 is formed in the opening provided in the insulating layer 44 via a UBM (Under Bump Metallurgy) layer 50, for example. The electronic device 100 is connected to a wiring substrate or the like via bumps 52, for example.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than those described above can also be adopted.
Examples of reference forms are added below.
1. Component (A): A photosensitive resin composition containing an alkali-soluble resin,
The component (A) contains component (a1): a biphenylaralkyl-type phenolic resin,
A photosensitive resin composition, wherein the tensile elongation of a cured film of the photosensitive resin composition is 10% or more and 200% or less, measured under Condition 1 below.
(Condition 1)
(i) The photosensitive resin composition is cured at 200° C. for 180 minutes to form the cured film, and a sample of 6.5 mm×20 mm×10 μm thick is prepared from the cured film.
(ii) Based on JIS K7161, a tensile test is performed on the sample under conditions of 23° C. and a test speed of 5 mm/min to determine the tensile elongation.
2. 1. The weight average molecular weight of the component (a1) is 2000 or more and 50000 or less. The photosensitive resin composition according to .
3. Component (B): Crosslinking agent
further comprising
1. wherein the component (B) comprises component (b1): a difunctional epoxy resin; or 2. The photosensitive resin composition according to .
4. Component (C): acid generator
further comprising
1. The component (C) comprises component (c1): a sulfonium compound or a salt thereof; to 3. The photosensitive resin composition according to any one.
5. 1. The component (A) further contains a component (a2): a phenolic resin other than the component (a1). to 4. The photosensitive resin composition according to any one.
6. Component (D): 1. further comprising a silane coupling agent; to 5. The photosensitive resin composition according to any one.
7. 1. A cured product of the photosensitive resin composition has a glass transition temperature of 150° C. or higher and 260° C. or lower; to 6. The photosensitive resin composition according to any one.
8. 1. The cured film has a film strength of 70 MPa or more and 150 MPa or less, as measured under the following condition 2. to 7. The photosensitive resin composition according to any one.
(Condition 2)
Equipment: Tensile/compression tester
Temperature: normal temperature
Tensile speed: 5mm/min
Specimen size: 6.5 mm x 20 mm x 10 µm thickness
9. 1. used for a buffer coat film or an insulating film for wiring; to 8. The photosensitive resin composition according to any one.

Hereinafter, the embodiments will be described in detail with reference to examples, but the present invention is not limited to the description of these examples.

(Examples 1 to 5, Comparative Examples 1 to 5)
A photosensitive resin composition was prepared according to the formulation shown in Table 1. Specifically, first, each component blended according to Table 1 was stirred and mixed under a nitrogen atmosphere, and filtered through a polyethylene filter having a pore size of 0.2 μm to obtain a varnish-like photosensitive resin composition. .
Details of each component listed in Table 1 are shown below. Also, in Table 1, the content of each component is the active amount.

((A) alkali-soluble resin)
(a2) Alkali-soluble resin 1: Novolac-type phenolic resin, phenolic resin obtained in Production Example 1 described later (a2) Alkali-soluble resin 2: Cresol-type phenolic resin, PR-56001, manufactured by Sumitomo Bakelite Co., Ltd. (a2) Alkali-soluble Resin 3: allyl phenolic resin, MEH-8000H, manufactured by Meiwa Kasei Co., Ltd. (a2) alkali-soluble resin 4: Zyloc-type phenolic resin, MEH-7800SS, manufactured by Meiwa Kasei Co., Ltd. (a1) alkali-soluble resin 5: biphenyl aralkyl-type phenolic resin 1, weight average molecular weight 600, MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd. (a1) alkali-soluble resin 6: biphenyl aralkyl type phenol resin 2, weight average molecular weight 4000, GPH-103, manufactured by Nippon Kayaku Co., Ltd. (a1) alkali-soluble resin 7: Pre-reacted resin obtained in Production Example 2 described later

((B) cross-linking agent)
(b1) cross-linking agent 1: phenoxy-type epoxy resin, YX-7105, manufactured by Mitsubishi Chemical Corporation (b1) cross-linking agent 2: bisphenol A-type epoxy resin, LX-01, manufactured by Osaka Soda Co., Ltd. Cross-linking agent 3: alkylated urea resin, Nikalac MX-270 Sanwa Chemical Co., Ltd.

(Photosensitizer)
Photosensitive agent 1: DS-427, manufactured by Daito Chemix Co., Ltd.

(solvent)
Solvent 1 (contained in resin): γ-butyrolactone

(adherence aid)
(D) Adhesion Aid 1: Silane Coupling Agent (3-glycidoxypropyltrimethoxysilane), KBM-403, Shin-Etsu Chemical Co., Ltd. Adhesion Aid 2: Mercaptotriazole Adhesion Aid 3: Silane Coupling Agent ( 3-methacryloxypropyltrimethoxysilane), KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.

((C) acid generator)
(c1) acid generator 1: sulfonium salt 1 (4-acetoxyphenyldimethylsulfonium tetrakis(pentafluorophenyl)borate), SI-B5, manufactured by Sanshin Chemical Industry Co., Ltd. (c1) acid generator 2: sulfonium salt 2 (4 - Acetoxyphenylmethylbenzylsulfonium tetrakis (pentafluorophenyl) borate), SI-B3A, manufactured by Sanshin Chemical Industry Co., Ltd. (c1) acid generator 3: sulfonium salt 3 (di (trifluoromethanesulfone) imide (4,8-di -n-butoxy-1-naphthyl)dibutylsulfonium), ZK-1232, manufactured by DSP Gokyo Food & Chemical Co., Ltd.

(Surfactant)
Surfactant 1: fluorine-based surfactant, FC4430, manufactured by 3M Japan

(Production Example 1) Production of alkali-soluble resin 1 64.9 g of m-cresol was placed in a four-necked glass round-bottom flask equipped with a thermometer, a stirrer, a raw material inlet and a dry nitrogen gas inlet tube, under a dry nitrogen stream. (0.60 mol), 43.3 g (0.40 mol) of p-cresol, 65.1 g of 30 mass% formaldehyde aqueous solution (0.65 mol of formaldehyde), and 0.63 g (0.005 mol) of oxalic acid dihydrate. ), the mixture was immersed in an oil bath, and a polycondensation reaction was carried out at 100° C. for 4 hours while refluxing the reaction solution. Then, after raising the temperature of the oil bath to 200° C. over 3 hours, the pressure inside the flask was reduced to 50 mmHg or less to remove moisture and volatile matter. Thereafter, the resin was cooled to room temperature to obtain a phenolic resin (alkali-soluble resin 1), which is a novolac-type phenolic resin having a weight average molecular weight of 3,200.

(Production Example 2) Production of alkali-soluble resin 7 Alkali-soluble resin 1 50 parts by mass, alkali-soluble resin 6 50 parts by mass, cross-linking agent 1 30 parts by mass, tetraphenylphosphine 0.4 parts by mass as a catalyst, solvent 1 45 parts by mass The mixture was charged, heated to 150° C., and stirred in a flask for 2 hours. After cooling to room temperature, the product was taken out from the flask to obtain a pre-reacted resin (alkali-soluble resin 7).

Methods for measuring the characteristics of the photosensitive resin composition are shown below.
(Growth rate)
The photosensitive resin composition obtained in each example was cured at 200° C. for 180 minutes to form a cured film. A sample having a thickness of 6.5 mm×20 mm×10 μm was prepared from the obtained cured film.
A tensile test of the sample was performed according to JIS K7161 using a tensile tester (Tensilon RTA-100) manufactured by Orientec under the conditions of 23° C. and a test speed of 5 mm/min. One sample was measured eight times, and the average value ("ave." in Table 1) was taken as the tensile elongation rate (%). Table 1 shows the results.

(Tg, coefficient of linear expansion (CTE)))
A cured film of the photosensitive resin composition obtained in each example was prepared at 200° C. for 180 minutes, and a test piece having a width of 3 mm×length of 10 mm×thickness of 10 mm was obtained from the obtained cured film.
Using a thermomechanical analyzer (TMA, manufactured by Seiko Instruments Inc., SS6000), the test piece of each example was measured at a starting temperature of 30 ° C., a measurement temperature range of 30 to 440 ° C., and a heating rate of 10 ° C./min. From the measurement results, Tg (°C) and linear expansion coefficient (ppm/°C) in the temperature range of 50 to 100°C were obtained. Table 1 shows the results.

(tensile strength)
The photosensitive resin composition obtained in each example was cured at 200° C. for 180 minutes to form a cured film, and a test piece of 6.5 mm×20 mm×10 μm thick was prepared from the obtained cured film. . The tensile strength (MPa) of the obtained test piece was measured under the following conditions. Table 1 shows the results.
Equipment: Tensilon RTC-1210A manufactured by Orientec
Temperature: Normal temperature (25°C)
Tensile speed: 5mm/min

(Processability evaluation)
For each of Examples 1 to 4 and Comparative Examples 1 to 5, the resulting varnish-like photosensitive resin composition was applied to a silicon wafer and heat-treated at 100° C./4 minutes to obtain a film thickness of about A resin film of 7.0 μm was obtained. This resin film was exposed to an optimum amount of light using an i-line stepper (manufactured by Nikon Corporation, NSR-4425i). Paddle development was carried out twice by adjusting the development time so that the difference in film thickness after development was 0.3 μm. The opening of the pattern formed in the resin film was observed with an optical microscope at a magnification of 200 to confirm the presence or absence of residue generation at the opening of 100 μm square.
◯: Size of residue is less than 5 μm ×: Size of residue is 5 μm or more Table 1 shows the evaluation results.

(low temperature curing)
As a measure of the low-temperature curability, the film breaking property of the cured film obtained using the composition obtained in each example was evaluated.
The photosensitive resin composition obtained in each example was coated on a 6-inch silicon wafer so that the thickness after curing was 10 μm, and prebaked at 100° C./4 minutes. Next, curing was performed at 200° C. for 180 minutes in a clean oven while controlling the oxygen concentration to 2000 ppm or less.
A test piece having a width of 3 mm, a length of 10 mm, and a thickness of 10 mm was obtained from the obtained cured film. The test piece was folded in half, and its appearance was observed and evaluated according to the following criteria.
○: No break ×: Partial break or complete break Table 1 shows the evaluation results.

From Table 1, the compositions obtained in each example had excellent workability and excellent curability at low temperatures.

This application claims priority based on Japanese Patent Application No. 2020-094819 filed on May 29, 2020, and the entire disclosure thereof is incorporated herein.

30 Interlayer insulating film 32 Passivation film 34 Top layer wiring 40 Rewiring layers 42, 44 Insulating layer 46 Rewiring 50 UBM layer 52 Bump 100 Electronic device

Claims (6)

Component (A): alkali-soluble resin,
Component (B): a cross-linking agent,
Component (C): an acid generator, and Component (D): a silane coupling agent A photosensitive resin composition comprising
The component (A) is
Component (a1): a biphenyl aralkyl-type phenolic resin, and
Component (a2): containing a phenolic resin other than the component (a1),
The component (B) contains component (b1): a bifunctional phenoxy-type epoxy resin,
The component (C) contains component (c1): a sulfonium compound or a salt thereof,
A photosensitive resin composition (however, a phenolic resin, a photosensitive agent, a cross-linking agent , and a negative photosensitive resin composition for forming a permanent film containing a compound containing a group having a nitrogen atom and a silanol group or a group that generates a silanol group by hydrolysis in one molecule.).
(Condition 1)
(i) The photosensitive resin composition is cured at 200° C. for 180 minutes to form the cured film, and a sample of 6.5 mm×20 mm×10 μm thick is prepared from the cured film.
(ii) Based on JIS K7161, a tensile test is performed on the sample under conditions of 23° C. and a test speed of 5 mm/min to determine the tensile elongation. The photosensitive resin composition according to claim 1, wherein the component (a1) has a weight average molecular weight of 2000 or more and 50000 or less. 3. The photosensitive resin composition according to claim 1, wherein the component ( c1) contains a sulfonium compound represented by the following general formula (1) or a salt thereof.

(In general formula (1) above, R ¹ is a hydrogen atom or an acyl group. R ² is a chain or branched hydrocarbon group or an optionally substituted benzyl group. R ³ is A chain or branched hydrocarbon group.) The photosensitive resin composition according to any one of claims 1 to 3, wherein a cured product of the photosensitive resin composition has a glass transition temperature of 150°C or higher and 260°C or lower. 5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the cured film has a film strength of 70 MPa or more and 150 MPa or less as measured under Condition 2 below.
(Condition 2)
Apparatus: Tensile/compression tester Temperature: Room temperature Tensile speed: 5mm/min
Specimen size: 6.5 mm x 20 mm x 10 µm thickness 6. The photosensitive resin composition according to any one of claims 1 to 5, which is used for a buffer coat film or an insulating film for wiring.

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