Photosensitive resin composition, method for producing resin film, and method for producing electronic device

Abstract

The present invention provides: a photosensitive resin composition that exhibits excellent thick film coatability and that can be used for formation of a photosensitive coating film exhibiting excellent sensitivity to exposure light and formation of a resin film exhibiting excellent adhesion to a substrate; a method for producing a resin film using the photosensitive resin composition; and a method for producing an electronic device by using the method for producing a resin film. A photosensitive resin composition according to the present invention contains a polybenzoxazole resin, a low-molecular-weight polyfunctional phenol compound having a plurality of hydroxy groups per molecule, a photosensitive agent, and an adhesion promotor. The contained amount of the low-molecular-weight polyfunctional phenol compound with respect to 100 parts by mass of the polybenzoxazole resin is preferably 0.5-5.0 parts by mass.

Description

Photosensitive resin composition, method for manufacturing a resin film, and method for manufacturing an electronic device

[0001] The present invention relates to a photosensitive resin composition, a method for manufacturing a resin film, and a method for manufacturing an electronic device.

[0002] Conventionally, photosensitive resin compositions are known that include photosensitive polyimides, which are polyimide resins to which photosensitive properties have been imparted, and photosensitive polybenzoxazoles, which contain a naphthoquinone diazide compound in a polybenzoxazole precursor.

[0003] For example, Patent Document 1 discloses a resin composition comprising a polyimide precursor or polybenzoxazole precursor, a polar solvent, and a naphthoquinone diazide compound as a photosensitive agent. Such a resin composition is coated onto a substrate and then subjected to exposure and development to form a patterned resin film. The patterned resin film is used as a surface protective film or interlayer insulating film for semiconductor devices.

[0004] Furthermore, Patent Document 2 discloses a protective film for a power semiconductor device obtained by curing a photosensitive resin composition containing a polybenzoxazole precursor having specific repeating units and a photoacid generator.

[0005] Surface protective films and interlayer insulating films for power semiconductor devices tend to become thicker, and there is a growing demand for photosensitive resin compositions that achieve both sensitivity and adhesion to the substrate.

[0006] International Publication No. 2014 / 115233, Japanese Patent Publication No. 2016-023226

[0007] However, the resin compositions described in Patent Documents 1 and 2 have problems such as insufficient thick-film coating ability, poor sensitivity of the resulting coating film, and poor adhesion to the substrate to which the resin composition is applied. Therefore, there is room for improvement in these resin compositions in terms of thick-film coating ability, improved sensitivity, and adhesion to the substrate.

[0008] The object of the present invention is to provide a photosensitive resin composition that can be used to form a photosensitive coating film that has excellent thick-film coating properties and excellent sensitivity to exposure light, and to form a resin film that has excellent adhesion to a substrate, to provide a method for manufacturing a resin film using the photosensitive resin composition, and to provide a method for manufacturing an electronic device using the method for manufacturing the resin film.

[0009] These objectives are achieved by the present invention as described in (1) to (10) below. (1) A photosensitive resin composition characterized by containing a polybenzoxazole resin, a low molecular weight polyfunctional phenol compound having a plurality of hydroxyl groups in its molecule, a photosensitive agent, and an adhesion aid.

[0010] (2) The photosensitive resin composition according to (1) above, wherein the low molecular weight polyfunctional phenol compound is at least one of the compounds represented by the following formulas (1) to (3).

[0011]

[0012]

[0013]

[0014] (3) The adhesion aid is the photosensitive resin composition according to either (1) or (2) above, comprising a silane compound.

[0015] (4) The photosensitive resin composition according to (3) above, wherein the adhesion aid is at least one of the compounds represented by the following formulas (4) to (7).

[0016]

[0017]

[0018]

[0019]

[0020] (5) The photosensitive resin composition according to any one of (1) to (4) above, wherein the content of the low molecular weight polyfunctional phenol compound is 0.5 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

[0021] (6) The photosensitive resin composition according to any one of (1) to (5) above, wherein the content of the adhesion aid is 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

[0022] (7) The photosensitive resin composition according to any one of (1) to (6) above, wherein the content of the photosensitive agent is 7.0 parts by mass or more and 25.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

[0023] (8) The photosensitive resin composition according to any one of (1) to (7) above, wherein the polybenzoxazole resin is a compound having repeating units represented by the following formula (A-1).

[0024]

[0025] (9) A method for producing a resin film, comprising the steps of: applying a photosensitive resin composition according to any one of (1) to (8) above to a substrate to obtain a photosensitive coating film; pre-baking the photosensitive coating film; exposing the pre-baked photosensitive coating film to an exposure treatment; developing the photosensitive coating film that has been exposed to an exposure treatment; and heating the photosensitive coating film remaining after development to cure it and obtain a resin film.

[0026] (10) A method for manufacturing an electronic device, characterized by using the method for manufacturing a resin film described in (9) above.

[0027] According to the present invention, it is possible to provide a photosensitive resin composition that can be used to form a photosensitive coating film that has excellent thick-film coating properties and excellent sensitivity to exposure light, and to form a resin film that has excellent adhesion to a substrate, a method for manufacturing a resin film using the photosensitive resin composition, and a method for manufacturing an electronic device using the method for manufacturing the resin film.

[0028] Figure 1 is a cross-sectional view showing a semiconductor device to which an electronic device according to a preferred embodiment is applied. Figure 2 is a partially enlarged view of the area enclosed by the dashed line in Figure 1. Figure 3 is a process diagram illustrating a method for manufacturing a resin film according to a preferred embodiment.

[0029] The photosensitive resin composition, the method for manufacturing a resin film, and the method for manufacturing an electronic device according to the present invention will be described in detail below based on preferred embodiments shown in the attached drawings.

[0030] [1] Photosensitive resin composition First, the photosensitive resin composition according to this embodiment will be described.

[0031] The photosensitive resin composition according to this embodiment contains a polybenzoxazole resin, a low molecular weight polyfunctional phenol compound having multiple hydroxyl groups in its molecule, a photosensitive agent, and an adhesion aid.

[0032] This configuration provides a photosensitive resin composition that can be used to form a photosensitive coating film with excellent thick-film coating properties and excellent sensitivity to exposure light, as well as a resin film with excellent adhesion to a substrate.

[0033] More specifically, the inventors have found that the inclusion of a polybenzoxazole resin and a low-molecular-weight polyfunctional phenol compound improves the ability to coat thick films and enhances the sensitivity of the photosensitive coating film formed using the photosensitive resin composition to exposure light and its solubility in developing solutions. Furthermore, because the development speed of the photosensitive coating film is increased, the manufacturing efficiency of electronic devices such as semiconductor devices and other electronic devices equipped with a resin film manufactured using the photosensitive coating film can be improved.

[0034] Furthermore, by including an adhesion aid in the photosensitive resin composition, the adhesion between the resin film formed using the photosensitive resin composition and the substrate can be improved. In particular, because it exhibits excellent adhesion not only to silicon (Si) but also to copper (Cu) and aluminum (Al), it is possible to form a resin film that exhibits excellent adhesion not only to silicon wafers but also to metal wiring.

[0035] In this invention, the term "polybenzoxazole resin" is a concept that includes not only the polybenzoxazole resin (A) as a polymer having a benzoxazole ring structure as described later, but also its precursors (for example, polymers that do not have a benzoxazole ring structure but have an amidophenol structure that is converted to a benzoxazole ring structure by a dehydration ring-closing reaction (a type of polyamide resin), etc.).

[0036] Furthermore, in this specification, the term "group" (atomic group) includes both unsubstituted and substituted groups unless otherwise specified. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups.

[0037] Furthermore, in this specification, the content of each component in a composition means the total amount of multiple substances present in the composition, unless otherwise specified, if there are multiple substances corresponding to each component in the composition.

[0038] [1-1] Polybenzoxazole resin The photosensitive resin composition of this embodiment comprises at least one of a polymer having a benzoxazole ring structure (hereinafter also referred to as "polybenzoxazole resin (A)") and its precursor.

[0039] Polybenzoxazole resin (A) is a polymer having a benzoxazole ring structure and is alkali soluble.

[0040] The inclusion of polybenzoxazole resin (A) improves the dispersibility of the resin in the photosensitive resin composition.

[0041] Furthermore, the photosensitive resin composition can significantly improve both the development speed and contrast during development of the photosensitive coating film formed using the composition, while also suppressing the generation of development residue. In addition, it can improve the physical properties of the resin film composed of the cured product of the photosensitive resin composition, such as its mechanical strength, thereby improving the uniformity of the film thickness and suppressing the occurrence of defects. These effects can also be obtained when the photosensitive resin composition contains a precursor of polybenzoxazole resin (A).

[0042] Polybenzoxazole resin (A) can be obtained, for example, by dehydrating and cyclizing a precursor of polybenzoxazole resin containing a structural unit represented by the following formula (PA1) by heat treatment at a temperature of 150°C to 380°C for 30 minutes to 50 hours.

[0043]

[0044] More specifically, the structural unit of formula (PA1) becomes the structural unit shown in formula (PBO1) below through dehydration and ring closure.

[0045]

[0046] If the photosensitive resin composition contains a precursor of polybenzoxazole resin (A) containing a structural unit represented by formula (PA1) as polybenzoxazole, the photosensitive resin composition may be subjected to the above heat treatment to dehydrate and cyclize the precursor, thereby obtaining polybenzoxazole resin (A). In other words, the photosensitive resin composition may contain polybenzoxazole resin (A) by heat treatment. Alternatively, if the photosensitive resin composition contains a precursor of polybenzoxazole resin (A) containing a structural unit represented by formula (PA1), the resin film may be prepared and then subjected to the above heat treatment to dehydrate and cyclize it, thereby obtaining polybenzoxazole resin (A). When polybenzoxazole resin (A) is obtained by dehydrating and cyclizing the precursor of polybenzoxazole resin (A), mechanical properties and thermal properties can be improved. This can suppress deformation of the resin film.

[0047] The polybenzoxazole resin included in the photosensitive resin composition is preferably a compound having repeating units represented by the following formula (A-1) (a precursor of polybenzoxazole resin (A)).

[0048]

[0049] When a polybenzoxazole resin, which has repeating units represented by formula (A-1), is included, its coexistence with a low-molecular-weight polyfunctional phenol compound makes it easier to adjust the sensitivity of the photosensitive coating to exposure and its solubility in the developer. Furthermore, even when the development speed of the photosensitive coating formed using the photosensitive resin composition is increased, the generation of development residue (scum) can be suppressed more effectively.

[0050] The lower limit of the weight-average molecular weight of the polybenzoxazole resin contained in the photosensitive resin composition is preferably 10,000, more preferably 12,000, and even more preferably 15,000. The upper limit of the weight-average molecular weight of the polybenzoxazole resin contained in the photosensitive resin composition is preferably 100,000, more preferably 75,000, and even more preferably 50,000.

[0051] By having a weight-average molecular weight within the aforementioned range of the polybenzoxazole resin contained in the photosensitive resin composition, a resin film made from the cured product of the photosensitive resin composition can be obtained that exhibits not only better adhesion to the substrate but also sufficient chemical resistance and heat resistance, while the fluidity of the photosensitive resin composition is improved, thereby enhancing coatability and flatness during coating.

[0052] The weight-average molecular weight of the polybenzoxazole resin contained in the photosensitive resin composition is determined by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0053] The polybenzoxazole resin content in the photosensitive resin composition is preferably 1.0% by mass or more, more preferably 5.0% by mass or more, and even more preferably 10.0% by mass or more, based on the total solid content of the photosensitive resin composition. This facilitates the formation of a resin film of appropriate thickness.

[0054] The upper limit of the polybenzoxazole resin content in the photosensitive resin composition is not particularly limited, but considering the balance with other components, it is preferably 70.0% by mass, and more preferably 50.0% by mass.

[0055] As described later, the photosensitive resin composition may contain resins other than polybenzoxazole resin, but the proportion of polybenzoxazole resin to the total amount of resin in the photosensitive resin composition is preferably 80.0% by mass or more, and more preferably 90.0% by mass or more.

[0056] [1-1-1] Method for producing polybenzoxazole resin The above polybenzoxazole resin can be obtained, for example, as follows.

[0057] First, a polymerization step (S1) is performed to polycondense a diamine monomer and a dicarboxylic acid monomer. Next, a low molecular weight component removal step (S2) is performed to remove the low molecular weight component and obtain a precursor of polybenzoxazole resin (A) containing the structural unit represented by the above formula (PA1) as a polybenzoxazole resin.

[0058] Furthermore, to obtain a photosensitive resin composition containing polybenzoxazole resin (A), a precursor of polybenzoxazole resin (A) containing the structural unit represented by formula (PA1) is heat-treated to dehydrate and cyclize it, thereby obtaining polybenzoxazole resin (A) having the structural unit represented by formula (PBO1).

[0059] [1-1-1-1] Polymerization step (S1) In the polymerization step (S1), a diamine monomer and a dicarboxylic acid monomer are polycondensed. Examples of polycondensation methods include melt polycondensation, acid chloride method, and direct polycondensation.

[0060] Alternatively, a method may be used to obtain an active ester-type dicarboxylic acid by reacting at least one compound selected from the group consisting of the compounds listed later as dicarboxylic acid monomers, tetracarboxylic dianhydride, trimellitic anhydride, and dicarboxylic acid dichloride with a compound having a hydroxyl group. In other words, this active ester-type dicarboxylic acid may also be used as a dicarboxylic acid monomer. Examples of compounds having a hydroxyl group include 1-hydroxybenzotriazole or its derivatives. Furthermore, when obtaining this active ester-type dicarboxylic acid, a condensing agent commonly used in ester synthesis, such as dicyclohexylcarbodiimide, can be used. In addition, an acid catalyst such as hydrochloric acid, sulfuric acid, benzenesulfonic acid, or toluenesulfonic acid may be added, and the reaction may proceed while removing water generated from the alcohol compound and carboxylic acid compound, thereby promoting esterification and obtaining the above-mentioned active ester-type dicarboxylic acid.

[0061] The diamine monomers and dicarboxylic acid monomers used in the synthesis of polybenzoxazole resins are described below. Note that only one diamine monomer and one dicarboxylic acid monomer may be used, or two or more diamine monomers, two or more dicarboxylic acid monomers, or both may be used.

[0062] [1-1-1-1-1] The diamine monomer used in diamine monomer polymerization is not limited, but for example, it is preferable to use a diamine monomer that contains an aromatic ring in its structure, and it is more preferable to use a diamine monomer that contains a phenolic hydroxyl group in its structure.

[0063] By producing polybenzoxazole resins using such diamine monomers as raw materials, the conformation of the polybenzoxazole resin can be more favorably controlled, and the dispersibility of the resulting composition can be further improved.

[0064] Here, as a diamine monomer containing a phenolic hydroxyl group in its structure, for example, a compound represented by the following formula (DA1) is preferred.

[0065] By producing a polybenzoxazole resin using such a diamine monomer as a raw material, the conformation of the polybenzoxazole resin can be more suitably controlled, and the molecular chains of the polybenzoxazole resin can form a denser structure. Therefore, it is considered that the molecular structure can be frozen by coordination in which the molecules of the polybenzoxazole resin and metal molecules are more strongly bonded, and adhesion to a substrate can be improved.

[0066] Note that when a diamine monomer represented by the following formula (DA1) is used, for example, the polybenzoxazole resin contains a structural unit represented by the following formula (PA3). That is, the polybenzoxazole resin preferably contains, for example, a structural unit represented by the following formula (PA3).

[0067]

[0068] In the above formula (DA1), R ４ is a group formed by one or more atoms selected from the group consisting of a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a chlorine atom, a fluorine atom, and a bromine atom. R ５ to R １０ each independently represent hydrogen or an organic group having 1 to 30 carbon atoms.

[0069]

[0070] In the above formula (PA3), R ４ , R ５ to R １０ are the same as those in the above formula (DA1).

[0071] R in the above formula (DA1) and the above formula (PA3) ４ is a group formed by one or more atoms selected from the group consisting of a hydrogen atom, a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a chlorine atom, a fluorine atom, and a bromine atom.

[0072] Note that R ４ is a divalent group. Here, the term divalent group refers to valence. That is, R ４This indicates that it has two bonds that connect to other atoms.

[0073] In the above formulas (DA1) and (PA3), R ４ If it contains carbon atoms, R ４ For example, the group is a group having 1 to 30 carbon atoms, preferably a group having 1 to 10 carbon atoms, more preferably a group having 1 to 5 carbon atoms, and even more preferably a group having 1 to 3 carbon atoms.

[0074] In the above formulas (DA1) and (PA3), R ４ If it contains carbon atoms, R ４ Specifically, examples include alkylene groups, arylene groups, halogen-substituted alkylene groups, halogen-substituted arylene groups, and so on.

[0075] The alkylene group may be a linear alkylene group or a branched alkylene group. Specific examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decanylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups. Specific examples of branched alkylene groups include -C(CH4). ３ ) ２ -, -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２CH ３ )CH ２ -, -C(CH ２ CH ３ ) ２ -CH ２ Examples include alkylethylene groups such as -.

[0076] Examples of arylene groups include phenylene groups, biphenylene groups, naphthylene groups, anthrylene groups, and groups in which two or more arylene groups are bonded together.

[0077] Specifically, halogen-substituted alkylene groups and halogen-substituted arylene groups can be obtained by substituting the hydrogen atoms in the alkylene group and arylene group, respectively, with halogen atoms such as fluorine, chlorine, and bromine. Among these, it is preferable to use a group in which the hydrogen atoms are substituted with fluorine atoms.

[0078] In the above formulas (DA1) and (PA3), R ４ If it does not contain carbon atoms, R ４ Specifically, examples include groups consisting of oxygen atoms or sulfur atoms.

[0079] In the above formulas (DA1) and (PA3), R ５ ~R １０ Each of these is independently hydrogen or an organic group having 1 to 30 carbon atoms, preferably, for example, hydrogen or an organic group having 1 to 10 carbon atoms, more preferably hydrogen or an organic group having 1 to 5 carbon atoms, even more preferably hydrogen or an organic group having 1 to 3 carbon atoms, and particularly preferably hydrogen or an organic group having 1 to 2 carbon atoms. This allows the aromatic rings of the polybenzoxazole resin to be closely arranged. Therefore, the molecular structure can be frozen in a coordination that more strongly bonds the molecules of the polybenzoxazole resin and the metal molecules, and the adhesion of the resin film formed using the photosensitive resin composition to the substrate can be improved.

[0080] In the above formulas (DA1) and (PA3), R ５ ~R １０Specific examples of organic groups having 1 to 30 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; alkenyl groups such as allyl, pentenyl, and vinyl groups; alkynyl groups such as ethynyl; alkylidene groups such as methylidene and ethylidene; aryl groups such as phenyl, naphthyl, and anthracenyl; aralkyl groups such as benzyl and phenethyl; cycloalkyl groups such as adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl; and alkaryl groups such as tolyl and xylyl.

[0081] Examples of diamine monomers represented by the above formula (DA1) include 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 4,4'-methylenebis(2-amino-3,6-dimethylphenol), 4,4'-methylenebis(2-aminophenol), 1,1-bis(3-amino-4-hydroxyphenyl)ethane, and 3,3'-diamino-4,4'-dihydroxydiphenyl ether. By using these diamine monomers, the aromatic rings of the polybenzoxazole resin are densely arranged. Therefore, the molecular structure can be frozen in a coordination that more strongly bonds the molecules of the polybenzoxazole resin and the metal molecules, and the adhesion of the resin film formed using the photosensitive resin composition to the substrate can be improved. Note that one or more of the above specific examples of diamine monomers can be used as the diamine monomer. The structural formulas of these diamine monomers are shown below.

[0082]

[0083] [1-1-1-1-2] The dicarboxylic acid monomer used in the polymerization of dicarboxylic acid monomers is not limited, but is preferably a dicarboxylic acid monomer that contains an aromatic ring in its structure.

[0084] As the dicarboxylic acid monomer containing an aromatic ring, it is preferable to use one represented by the following formula (DC1). By producing a polybenzoxazole resin using such a dicarboxylic acid monomer as a raw material, the conformation of the polybenzoxazole resin can be more favorably controlled, and its dispersibility in the photosensitive resin composition can be improved. As a result of the improved dispersibility, a photosensitive resin composition can be obtained that can be used to form a resin film that is particularly less prone to generating foreign matter even in high temperature and high humidity environments.

[0085]

[0086] In the above formula (DC1), R １１ R is a group formed by one or more atoms selected from the group consisting of hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, silicon, chlorine, fluorine, and bromine atoms. １２ ~R １９ Each of these independently represents either hydrogen or an organic group having 1 to 30 carbon atoms.

[0087] For example, when a dicarboxylic acid monomer represented by the above formula (DC1) is used, the polybenzoxazole resin typically contains a structural unit represented by the following formula (PA4). In the following formula (PA4), R １１ , R １２ ~R １９ The definition is the same as in the above formula (DC1).

[0088]

[0089] In the above formulas (DC1) and (PA4), R １１ This is a group formed by one or more atoms selected from the group consisting of hydrogen, carbon, oxygen, nitrogen, sulfur, phosphorus, silicon, chlorine, fluorine, and bromine atoms.

[0090] Note R １１ R is a divalent group. Here, a divalent group refers to its valence. That is, R １１ This indicates that it has two bonds that connect to other atoms.

[0091] In the above formulas (DC1) and (PA4), R １１ If it contains carbon atoms, R １１ For example, the group is a group having 1 to 30 carbon atoms, preferably a group having 1 to 10 carbon atoms, more preferably a group having 1 to 5 carbon atoms, and even more preferably a group having 1 to 3 carbon atoms.

[0092] In the above formulas (DC1) and (PA4), R １１ If it contains carbon atoms, R １１ Specifically, examples include alkylene groups, arylene groups, halogen-substituted alkylene groups, halogen-substituted arylene groups, and so on.

[0093] The alkylene group may be a linear alkylene group or a branched alkylene group. Specific examples of linear alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decanylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups. Specific examples of branched alkylene groups include -C(CH4). ３ ) ２ -, -CH(CH ３ )-,-CH(CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ３ )-,-C(CH ３ ) (CH ２ CH ２ CH ３ )-,-C(CH ２ CH ３ ) ２ - Alkyl methylene groups such as -CH(CH ３ )CH ２ -, -CH(CH ３ )CH(CH ３ )-,-C(CH ３ ) ２ CH ２ -, -CH(CH ２ CH ３ )CH ２ -, -C(CH ２CH ３ ) ２ -CH ２ alkylethylene groups such as the foregoing are exemplified.

[0094] Specific examples of arylene groups include phenylene groups, biphenylene groups, naphthylene groups, anthrylene groups, and groups formed by bonding two or more arylene groups to each other.

[0095] Specific examples of halogen-substituted alkylene groups and halogen-substituted arylene groups that can be used include those obtained by substituting a hydrogen atom in the above-described alkylene groups or arylene groups with a halogen atom such as a fluorine atom, a chlorine atom, or a bromine atom. Among these, those obtained by substituting hydrogen atoms with fluorine atoms are preferable.

[0096] In the above formula (DC1) and the above formula (PA4), R １１ does not contain a carbon atom, specific examples of R １１ include groups consisting of an oxygen atom or a sulfur atom.

[0097] In the above formula (DC1) and the above formula (PA4), R １２ to R １９ are each independently hydrogen or an organic group having 1 to 30 carbon atoms; they are preferably hydrogen or an organic group having 1 to 10 carbon atoms, more preferably hydrogen or an organic group having 1 to 5 carbon atoms, still more preferably hydrogen or an organic group having 1 to 3 carbon atoms, and particularly preferably hydrogen.

[0098] In the above formula (DC1) and the above formula (PA4), R １２ to R １９Specific examples of organic groups having 1 to 30 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; alkenyl groups such as allyl, pentenyl, and vinyl groups; alkynyl groups such as ethynyl; alkylidene groups such as methylidene and ethylidene; aryl groups such as phenyl, naphthyl, and anthracenyl; aralkyl groups such as benzyl and phenethyl; cycloalkyl groups such as adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl; and alkaryl groups such as tolyl and xylyl.

[0099] Specifically, diphenyl ether 4,4'-dicarboxylic acid, isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, etc., can be used as dicarboxylic acid monomers. Of the above specific examples, it is preferable to use at least one of diphenyl ether 4,4'-dicarboxylic acid and isophthalic acid as the dicarboxylic acid monomer, and it is more preferable to use diphenyl ether 4,4'-dicarboxylic acid.

[0100] This results in a dense arrangement of aromatic rings in the polybenzoxazole resin. Consequently, the molecular structure can be frozen in a coordination that more strongly bonds the polybenzoxazole resin molecules and metal molecules, improving the adhesion of the resin film formed using the photosensitive resin composition to the substrate.

[0101] Furthermore, the amino groups at the ends of the polybenzoxazole resin may be modified simultaneously with or after the polymerization step (S1). Modification can be carried out, for example, by reacting a specific acid anhydride or a specific monocarboxylic acid with a diamine monomer or polybenzoxazole resin. More specifically, the polybenzoxazole resin may be one in which the terminal amino groups are modified with the above-mentioned specific acid anhydride or the above-mentioned specific monocarboxylic acid. The above-mentioned specific acid anhydride and the above-mentioned specific monocarboxylic acid have one or more functional groups selected from the group consisting of alkenyl groups, alkynyl groups, and hydroxyl groups. Furthermore, as the above-mentioned specific acid anhydride and the specific monocarboxylic acid, those containing a nitrogen atom are preferred, for example. This can improve the wettability of the photosensitive resin composition after post-baking with metals such as Cu and Al.

[0102] Examples of the specific acid anhydrides mentioned above include maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, 4-cyclohexene-1,2-dicarboxylic acid anhydride, exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride, 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, itaconic anhydride, hetic acid anhydride, 4-ethynylphthalic anhydride, 4-phenylethynylphthalic anhydride, and 4-hydroxyphthalic anhydride. One or more of the above specific examples can be used as the specific acid anhydride.

[0103] Furthermore, when the amino groups at the ends of a polybenzoxazole resin are modified with a specific cyclic acid anhydride, the cyclic acid anhydride undergoes ring opening. Alternatively, after modifying the polybenzoxazole resin, the structural units derived from the cyclic acid anhydride can be closed to form an imide ring. Methods for ring closing include, for example, heat treatment.

[0104] Furthermore, specific examples of the above-mentioned particular monocarboxylic acids include 5-norbornene-2-carboxylic acid, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, and others, and one or more selected from these can be used in combination.

[0105] Furthermore, the carboxyl groups at the ends of the polybenzoxazole resin may be modified simultaneously with or after the polymerization step (S1). Modification can be carried out, for example, by reacting a dicarboxylic acid monomer or polybenzoxazole resin with a specific nitrogen atom-containing heteroaromatic compound. More specifically, the polybenzoxazole resin may be one in which the terminal carboxyl groups are modified with a specific nitrogen atom-containing heteroaromatic compound. The specific nitrogen atom-containing heteroaromatic compounds mentioned above are compounds having one or more functional groups selected from the group consisting of 1-(5-1H-triazoyl)methylamino group, 3-(1H-pyrazoyl)amino group, 4-(1H-pyrazoyl)amino group, 5-(1H-pyrazoyl)amino group, 1-(3-1H-pyrazoyl)methylamino group, 1-(4-1H-pyrazoyl)methylamino group, 1-(5-1H-pyrazoyl)methylamino group, (1H-tetrazol-5-yl)amino group, 1-(1H-tetrazol-5-yl)methylamino group, and 3-(1H-tetrazol-5-yl)benzamino group. This increases the number of lone pairs of electrons in the photosensitive resin composition. Therefore, the wettability of the photosensitive resin composition with metals such as Cu and Al can be improved after pre-baking and post-baking.

[0106] Examples of the above-mentioned specific nitrogen atom-containing heteroaromatic compounds include 5-aminotetrazole and the like.

[0107] [1-1-1-2] Low molecular weight component removal step (S2) After the polymerization step (S1) described above, it is preferable to perform a low molecular weight component removal step (S2) to remove the low molecular weight components.

[0108] Specifically, the organic layer containing a mixture of low molecular weight components and polybenzoxazole resin is concentrated by filtration or other means, and then redissolved in an organic solvent such as water / isopropanol. This allows the precipitate to be filtered off, and a polybenzoxazole resin from which the low molecular weight components have been removed can be obtained.

[0109] Furthermore, with respect to the polybenzoxazole resin, it is preferable to prepare a photosensitive resin composition that is a varnish without going through a step in which the solvent completely evaporates and dries after the low molecular weight component removal step described above.

[0110] This suppresses the decrease in dispersibility of the polybenzoxazole resin due to intermolecular interactions. As a result, a photosensitive resin composition is obtained that can form a resin film that is less likely to generate foreign matter even in high temperature and high humidity environments.

[0111] Furthermore, polybenzoxazole resin (A) can be produced using a precursor of polybenzoxazole resin (A) containing the structural unit represented by the above formula (PA1) (polybenzoxazole resin as a precursor).

[0112] Specifically, for example, a precursor of a polybenzoxazole resin containing the structural unit represented by the above formula (PA1) can be heat-treated, for example, at a temperature of 150°C to 380°C for 30 minutes to 50 hours to dehydrate and closure the ring, thereby obtaining a polybenzoxazole resin (A).

[0113] Here, the structural unit of formula (PA1) becomes the structural unit shown in formula (PBO1) through dehydration and ring closure. [1-2] Low molecular weight polyfunctional phenolic compounds

[0114] The photosensitive resin composition of this embodiment contains a low-molecular-weight polyfunctional phenol compound having multiple hydroxyl groups in its molecule.

[0115] The inclusion of a low-molecular-weight polyfunctional phenol compound in the photosensitive resin composition improves its ability to coat thick films on a substrate. Furthermore, it improves the sensitivity to exposure light and solubility in developing solutions of the photosensitive coating formed using the photosensitive resin composition. In addition, it helps suppress the generation of developing residue (scum) even when the development speed of the photosensitive coating formed using the photosensitive resin composition is increased.

[0116] The molecular weight of such low molecular weight polyfunctional phenol compounds is preferably 50 to 1000, more preferably 150 to 750, and even more preferably 200 to 500.

[0117] This makes it possible to improve the thick-film coating properties of the photosensitive resin composition, as well as the sensitivity to exposure light and solubility in developing solutions of the photosensitive coating film formed using the photosensitive resin composition.

[0118] From the viewpoint of ensuring good thick-film coating properties, the number of hydroxyl groups in the molecule of a low-molecular-weight polyfunctional phenol compound is preferably between two and six.

[0119] Specific examples of low molecular weight polyfunctional phenolic compounds include 4-ethylresorcinol, 2-propylresorcinol, 4-butylresorcinol, 4-hexylresorcinol, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 4,4'-dihydroxydiphenyl sulfide, 3,3'-dihydroxydiphenyl disulfide, 4,4'-dihydroxydiphenyl sulfone, 2,2'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylmethane, 4,4',4''-trihydroxytriphenylmethane, 2,2'-dihydroxydiphenyl ether, and 4,4'-dihydroxydiphenyl Examples include nyl ethers, biphenols, 2,2'-methylenebisphenol, 4,4'-(1,3-dimethylbutylidene)diphenol, 4,4'-(2-ethylhexylidene)diphenol, 4,4'-ethylidenebisphenol, 2,2'-ethylenedioxydiphenol, 3,3'-ethylenedioxydiphenol, biphenyl-2,3',4,5',6-pentaol (phloroglucid), thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,5-bis(o-hydroxyphenoxy)-3-oxapentane, bisphenol A, bisphenol F, etc.

[0120] The low molecular weight polyfunctional phenol compound is preferably at least one of the compounds represented by the following formulas (1) to (3).

[0121]

[0122]

[0123]

[0124] This allows for improved thick-film coating properties, and further enhances the sensitivity to exposure light and solubility in developing solutions of the photosensitive coating film formed using the photosensitive resin composition.

[0125] The lower limit of the content of the low molecular weight polyfunctional phenol compound is preferably 0.5 parts by mass, more preferably 1.0 part by mass, and even more preferably 1.5 parts by mass, when the content of the polybenzoxazole resin is 100 parts by mass. The upper limit of the content of the low molecular weight polyfunctional phenol compound is preferably 5.0 parts by mass, more preferably 4.0 parts by mass, and even more preferably 3.0 parts by mass, when the content of the polybenzoxazole resin is 100 parts by mass.

[0126] This improves the ability to coat thick films when applying the photosensitive resin composition onto a substrate, enhances the sensitivity of the photosensitive coating film formed using the photosensitive resin composition to exposure light, and further improves the curability of the photosensitive resin composition. In addition, it further improves the adhesion of the resin film formed using the photosensitive resin composition to the substrate.

[0127] [1-3] Photosensitive agent: The photosensitive agent generates active species in response to light, which hardens the photosensitive resin composition.

[0128] As the photosensitive agent, known photosensitive agents can be used, specifically, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1- Alkylphenone compounds such as ONE, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-ONE, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; benzophenone compounds such as benzophenone, 4,4'-bis(dimethylamino)benzophenone, 2-carboxybenzophenone; benzoin methyl ether, benzoin ethyl Benzoin compounds such as ethers, benzoin isopropyl ether, and benzoin isobutyl ether; thioxanthone compounds such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone; 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxynaphthyl)- Halomethylated triazine compounds such as 4,6-bis(trichloromethyl)-s-triazine and 2-(4-ethoxycarboquinylnaphthyl)-4,6-bis(trichloromethyl)-s-triazine; halomethylated oxadiazole compounds such as 2-trichloromethyl-5-(2'-benzofuryl)-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2'-benzofuryl)vinyl]-1,3,4-oxadiazole, 4-oxadiazole, and 2-trichloromethyl-5-furyl-1,3,4-oxadiazole;Biimidazole compounds such as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole; 1,2-octanedione, 1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), etanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetate Examples include oxime ester compounds such as ethyloxime; naphthoquinone compounds such as 1,2-naphthoquinone diazide-4-sulfonic acid ester and 1,2-naphthoquinone diazide-5-sulfonic acid ester; titanocene compounds such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium; benzoic acid ester compounds such as p-dimethylaminobenzoic acid and p-diethylaminobenzoic acid; and acridine compounds such as 9-phenylacridine. One or more of these can be used in combination. Among these, naphthoquinone compounds are particularly preferred.

[0129] The lower limit of the photosensitive agent content is preferably 7.0 parts by mass, more preferably 8.5 parts by mass, even more preferably 10.0 parts by mass, and particularly preferably 12.0 parts by mass, per 100 parts by mass of polybenzoxazole resin. The upper limit of the photosensitive agent content is preferably 25.0 parts by mass, more preferably 23.0 parts by mass, and even more preferably 20.0 parts by mass, per 100 parts by mass of polybenzoxazole resin.

[0130] This makes it possible to improve the sensitivity of the photosensitive coating film formed using the photosensitive resin composition to exposure light, and to improve the curability of the photosensitive coating film.

[0131] [1-4] The photosensitive resin composition contains an adhesion aid.

[0132] The adhesion enhancer has the function of improving the adhesion of the resin film formed using the photosensitive resin composition to the substrate.

[0133] Examples of adhesion enhancers include triazole compounds, silane compounds, imide compounds, titanium coupling agents, aluminum coupling agents, and zirconium coupling agents, but silane compounds are preferred among them.

[0134] This makes it possible to improve the affinity between the photosensitive resin composition and the substrate, and to improve the adhesion between the resin film formed using the photosensitive resin composition and the substrate.

[0135] Specifically, the triazole compounds include 4-amino-1,2,4-triazole, 4H-1,2,4-triazole-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-amine, 3,4-diamino-4H-1,2,4-triazole, 3,5-diamino-4H-1,2,4-triazole, and 1,2,4 Examples of 1,2,4-triazoles include -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-4-methyl-1,2,4-triazole, and 4-methyl-1,2,4-triazole-3-carboxamide. One or more selected from these can be used in combination.

[0136] Specifically, silane compounds include vinylsilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; epoxysilanes such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane; styrylsilanes such as p-styryltrimethoxysilane; and 3-methacryloxypropylmethyldimethoxysilane and 3-methacryloxy Methacrylsilanes such as propyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane; acrylicsilanes such as 3-acryloxypropyltrimethoxysilane; isocyanurate silanes; alkylsilanes; ureidosilanes such as 3-ureidopropyltrialkoxysilane; mercaptosilanes such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; isocyanate silanes such as 3-isocyanatetopropyltriethoxysilane;Condensate of cyclohexene-1,2-dicarboxylic acid anhydride and 3-aminopropyltriethoxysilane, condensate of 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride and 3-aminopropyltriethoxysilane, condensate of 4,4'-oxydiphthalic acid anhydride and 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N,N'-bis[3-(trimethoxysilyl)propyl Examples of aminosilane compounds include ethylenediamine, N,N'-bis-(3-triethoxysilylpropyl)ethylenediamine, N,N'-bis[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis[3-(methyldiethoxysilyl)propyl]ethylenediamine, N,N'-bis[3-(dimethylmethoxysilyl)propyl]ethylenediamine, N-[3-(methyldimethoxysilyl)propyl]-N'-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N'-bis[3-(trimethoxysilyl)propyl]diaminopropane, N,N'-bis[3-(trimethoxysilyl)propyl]diaminohexane, N,N'-bis[3-(trimethoxysilyl)propyl]diethylenetriamine, and others. One or more selected from these can be used in combination. The adhesion aid is preferably at least one of the compounds represented by the following formulas (4) to (7).

[0137]

[0138]

[0139]

[0140]

[0141] By using these compounds, the affinity between the photosensitive resin composition and the substrate can be further improved, and the adhesion between the resin film formed using the photosensitive resin composition and the substrate can be further improved. Furthermore, these compounds can more effectively suppress the generation of development residue (scum) even when the development speed of the photosensitive coating film formed using the photosensitive resin composition is increased.

[0142] Examples of imide compounds include those listed below. These can be used individually or in combination of two or more.

[0143]

[0144] The lower limit of the content of the adhesion aid in the photosensitive resin composition is preferably 1.0 part by mass, more preferably 2.0 parts by mass, even more preferably 3.0 parts by mass, and particularly preferably 4.0 parts by mass, per 100 parts by mass of polybenzoxazole resin. The upper limit of the content of the adhesion aid in the photosensitive resin composition is preferably 10.0 parts by mass, more preferably 9.0 parts by mass, and even more preferably 8.0 parts by mass, per 100 parts by mass of polybenzoxazole resin.

[0145] This allows the adhesion promoter to be more favorably dispersed in the photosensitive resin composition, resulting in superior adhesion of the resin film formed using the photosensitive resin composition to the substrate. Furthermore, it is possible to more effectively suppress the reduction in solubility of the photosensitive coating film formed using the photosensitive resin composition in the developer solution caused by the adhesion promoter.

[0146] [1-5] The photosensitive resin composition may contain a surfactant. By including a surfactant, the coatability of the photosensitive resin composition and the flatness of the resin film formed using the photosensitive resin composition can be further improved.

[0147] Examples of surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene aryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether; and nonionic surfactants such as polyoxyethylene dialkyl esters such as polyoxyethylene dilaurate and polyoxyethylene distearate; as well as F-Top EF301, F-Top EF303, F-Top EF352 (manufactured by Shin Akita Chemical Co., Ltd.), Megafac F171, Megafac F172, Megafac F173, Megafac F177, Megafac F444, and others. Fluorine-based surfactants commercially available under names such as Gafac F470, Megafac F471, Megafac F475, Megafac F482, Megafac F477 (manufactured by DIC Corporation), 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.); organosiloxane copolymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); (meth)acrylic acid copolymer Polyflow No. Examples include 57 and 95 (manufactured by Kyoeisha Chemical Co., Ltd.).

[0148] As surfactants, silicone-based surfactants (e.g., polyether-modified dimethylsiloxane) can also be preferably used. Examples of silicone-based surfactants include the SH series, SD series, and ST series from Toray Dow Corning, the BYK series from BIC Chemie Japan, the KP series from Shin-Etsu Chemical Co., Ltd., the Disform® series from NOF Corporation, and the TSF series from Toshiba Silicone Co., Ltd.

[0149] In particular, the surfactant preferably contains an organically modified dimethylsiloxane represented by the following formula (E-1).

[0150] Accordingly, even when the photosensitive resin composition absorbs moisture, the function of the surfactant is less likely to decrease, and the solubility of the photosensitive coating film formed using the photosensitive resin composition in a developer can be further enhanced. In addition, the organically modified dimethylsiloxane contributes to suppressing the generation of development residue (scum) even when the development speed of the photosensitive coating film formed using the photosensitive resin composition is increased.

[0151]

[0152] In the above formula (E-1), X represents a polyether (polyoxyalkylene) group, a polyester group or an aralkyl group, and m and n each represent an integer of 1 or more and 100 or less. Further, when X in the above formula (E-1) is a polyether group, a polyether group represented by the following formula (2-1) is preferably used as X.

[0153]

[0154] In the above formula (2-1), R ２０ represents an alkyl group having 1 to 6 carbon atoms, R ２１ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkyl ether group having 1 to 6 carbon atoms, or an unsaturated alkyl ether group having 1 to 6 carbon atoms, EO represents an ethylene oxide group, and PO represents a propylene oxide group. o represents an integer of 1 or more, and p represents an integer of 0 or more. The order of EO and PO may be random.

[0155] Accordingly, the solubility of the photosensitive coating film formed using the photosensitive resin composition in a developer can be further enhanced. In addition, a photosensitive resin composition that particularly improves the storage stability of the photosensitive resin composition and can form a resin film in which foreign matter is less likely to be generated even in a high-temperature and high-humidity environment can be obtained.

[0156] When X in the above formula (E-1) contains a propylene oxide group, the lower limit of the molar ratio of the propylene oxide group to the total molar amount of the ethylene oxide group and the propylene oxide group is preferably 1.0%, more preferably 10.0%, and even more preferably 20.0% or more. When X in the above formula (E-1) contains a propylene oxide group, the upper limit of the molar ratio of the propylene oxide group to the total molar amount of the ethylene oxide group and the propylene oxide group is preferably 99.0%, more preferably 90.0%, and even more preferably 80.0%.

[0157] This improves wettability with metals. Furthermore, it enhances the solubility of the photosensitive coating film formed using the photosensitive resin composition in the developer.

[0158] When X in the above formula (E-1) is a polyester group, the polyester group represented by the following formula (2-2) is preferably used as X.

[0159]

[0160] In the above equation (2-2), R ２２ , R ２３ , R ２４ and R ２５ Each of these independently represents an alkyl group having between 1 and 20 carbon atoms, and r represents an integer of 1 or more.

[0161] When X in the above formula (E-1) is an aralkyl group, the aralkyl group represented by the following formula (2-3) is preferably used as X.

[0162]

[0163] In the above equation (2-3), R ２６ This represents an alkyl group having 1 to 30 carbon atoms.

[0164] The lower limit of the ratio of m to the sum of m and n shown in the above formula (E-1) is preferably 0.5%, more preferably 1.0%, even more preferably 5.0%, and particularly preferably 10.0%. The upper limit of the ratio of m to the sum of m and n shown in the above formula (E-1) is preferably 60.0%, more preferably 50.0%, even more preferably 40.0%, and particularly preferably 30.0%.

[0165] This improves wettability with metals. Furthermore, it enhances the solubility of the photosensitive coating film formed using the photosensitive resin composition in the developer.

[0166] The lower limit of the surfactant content is preferably 0.03 parts by mass, more preferably 0.05 parts by mass, and even more preferably 0.10 parts by mass, per 100 parts by mass of polybenzoxazole resin. The upper limit of the surfactant content is preferably 5.0 parts by mass, more preferably 2.0 parts by mass, and even more preferably 1.5 parts by mass, per 100 parts by mass of polybenzoxazole resin.

[0167] This improves the applicability of the photosensitive resin composition and further enhances the flatness of the photosensitive coating and resin film formed using the photosensitive resin composition.

[0168] [1-6] The photosensitive resin composition may contain a thermal crosslinking agent that can react with the polybenzoxazole resin by heat.

[0169] This makes it possible to achieve particularly excellent mechanical properties, such as tensile elongation at break, in the cured product (resin film) obtained by post-baking the photosensitive resin composition. Furthermore, it is possible to further improve the sensitivity of the photosensitive coating film formed using the photosensitive resin composition to exposure light. In addition, the thermal crosslinking agent contributes to suppressing the generation of development residue (scum) even when the development speed of the photosensitive coating film formed using the photosensitive resin composition is increased.

[0170] Specifically, thermal crosslinking agents include compounds having a methylol group such as 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol (paraxylene glycol), 1,3,5-benzenetrimethanol, 4,4-biphenyldimethanol, 2,6-pyridinedimethanol, 2,6-bis(hydroxymethyl)-p-cresol, and 4,4'-methylenebis(2,6-dialkoxymethylphenol); compounds having an alkoxymethyl group such as 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, 2,6-naphthalenedicarboxylate methyl, and 4,4'-methylenebis(2,6-dimethoxymethylphenol); methylolmelamine compounds represented by hexamethylmelamine and hexasubtanolmelamine; and alkoxymethyl compounds such as hexamethoxymelamine. Examples include coximamine compounds; alkoxymethyl glycoluryl compounds such as tetramethoxymethyl glycoluryl; methylolurea compounds such as methylolbenzoguanamine compounds and dimethylolethyleneurea; cyano compounds such as dicyanoaniline, dicyanophenol, and cyanophenylsulfonic acid; isocyanate compounds such as 1,4-phenylenediisocyanate and 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; epoxy group-containing compounds such as ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, isocyanurate triglycidyl, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene-based epoxy resin, biphenyl type epoxy resin, and phenol novolac resin type epoxy resin; and maleimide compounds such as N,N'-1,3-phenylenedimaleimide and N,N'-methylenedimaleimide. One or more selected from these can be used in combination.

[0171] The lower limit of the thermal crosslinking agent content is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1.0 part by mass, and particularly preferably 3.0 parts by mass, per 100 parts by mass of polybenzoxazole resin. The upper limit of the thermal crosslinking agent content is preferably 20.0 parts by mass, more preferably 15.0 parts by mass, and even more preferably 10.0 parts by mass, per 100 parts by mass of polybenzoxazole resin.

[0172] This makes it possible to more effectively suppress the decrease in chemical resistance after baking, even when the thermal crosslinking agent has solvating functional groups such as phenolic hydroxyl groups.

[0173] [1-7] The solvent-sensitive resin composition may contain a solvent. This results in the photosensitive resin composition having, for example, a varnish-like appearance and better coatability.

[0174] The solvent is used such that the concentration of total solids (non-volatile components) in the photosensitive resin composition is preferably 10.0% by mass or more and 60.0% by mass or less, more preferably 20.0% by mass or more and 50.0% by mass or less, and even more preferably 30.0% by mass or more and 48.0% by mass or less.

[0175] This allows for better dissolution or dispersion of each component, and ensures better application properties.

[0176] The solvent is preferably a lactone-based solvent. Specifically, the mass ratio of the lactone-based solvent in the solvent is preferably 95.0% or more, more preferably 97.0% or more, and even more preferably 99.0% or more.

[0177] This increases the development speed of the photosensitive coating when solvent remains in the photosensitive coating formed using the photosensitive resin composition. As a result, the cycle time for resin film formation can be shortened, further improving the manufacturing efficiency of electronic devices.

[0178] Examples of lactone-based solvents include γ-butyrolactone (GBL) and γ-valerolactone. One or more of these can be selected and used in combination, but it is preferable that the lactone-based solvent mainly consists of γ-butyrolactone (GBL).

[0179] GBL (Glass Bulletin) can significantly increase the development speed of photosensitive coatings while more effectively suppressing development residue (scum). As a result, it is possible to shorten the cycle time for resin film formation while forming resin films with higher patterning accuracy.

[0180] The mass ratio of GBL in the lactone-based solvent is preferably 60.0% or more, and more preferably 80.0% or more. This allows the aforementioned effects to be exhibited more significantly.

[0181] [1-8] Other resin photosensitive resin compositions may contain resins other than polybenzoxazole resins. Hereinafter, such resins will also be referred to as "other resins" in this section.

[0182] Other resins include, for example, alkali-soluble resins such as polyamide resins (excluding polybenzoxazole resins), phenolic resins, hydroxystyrene resins, and cyclic olefin resins. One or more of these can be used in combination. Examples of polyamide resins include precursors of polyimide resins.

[0183] As the polyamide resin, for example, one containing structural units represented by the following formula (PA2) may be used.

[0184] A polyamide resin containing the structural unit represented by the following formula (PA2) is a precursor of polyimide resin. A polyamide resin containing the structural unit represented by the following formula (PA2) can be dehydrated and cyclized to a polyimide resin by heat treatment, for example, at a temperature of 150°C to 380°C for 30 minutes to 50 hours. Here, the structural unit of the following formula (PA2) becomes the structural unit shown by the following formula (PI1) through dehydration and cyclization.

[0185] If the polyamide resin contains structural units represented by the following formula (PA2), the photosensitive resin composition may be subjected to the above heat treatment to dehydrate and closure the ring, thereby obtaining a polyimide resin. In other words, the photosensitive resin composition subjected to the above heat treatment may contain a polyimide resin.

[0186] Furthermore, if the polyamide resin contains structural units represented by the following formula (PA2), the resin film may be dehydrated and ring-closed by the above heat treatment after preparation to obtain a polyimide resin.

[0187]

[0188] In the above formula (PA2), R Ｂ and R Ｃ Each of these is an organic group having between 1 and 30 carbon atoms.

[0189]

[0190] In the above formula (PI1), R Ｂ and R Ｃ This is the same as the above formula (PA2).

[0191] In the above formulas (PA2) and (PI1), R Ｂ and R Ｃ Specifically, it is preferable that this is an organic group having an aromatic ring.

[0192] Specifically, organic groups having aromatic rings are preferably those containing a benzene ring, a naphthalene ring, or an anthracene ring, and more preferably those containing a benzene ring. This improves the dispersibility of the polyamide resin and enhances the uniformity of the resin film.

[0193] [1-9] Other components The photosensitive resin composition may contain components other than those listed above. Hereinafter, such components will also be referred to as "other components" in this section.

[0194] Other ingredients include, for example, fillers, sensitizers, antioxidants, film-forming agents, and stabilizers.

[0195] The filler is appropriately selected, for example, according to the mechanical and thermal properties required for the resin film formed by the photosensitive resin composition.

[0196] Examples of fillers include inorganic fillers and organic fillers. Examples of inorganic fillers include silica such as molten crushed silica, molten spherical silica, crystalline silica, secondary aggregated silica, and fine powdered silica; metal compounds such as alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, silicon carbide, aluminum hydroxide, magnesium hydroxide, and titanium white; talc; clay; mica; and glass fibers. One or more of these can be selected and used in combination.

[0197] Examples of organic fillers include organosilicone powder and polyethylene powder, and one or more of these can be used in combination.

[0198] [1-10] Method for preparing a photosensitive resin composition The method for preparing the photosensitive resin composition is not limited, and known methods can be used depending on the constituent components.

[0199] For example, the above components can be mixed and the solid components dissolved in a solvent to prepare the composition. This allows for the production of a varnish-like photosensitive resin composition.

[0200] From the viewpoint of suppressing moisture absorption of the photosensitive resin composition as much as possible, it is preferable to prepare the photosensitive resin composition entirely under a nitrogen atmosphere.

[0201] [2] Resin films formed using the photosensitive resin composition for electronic devices are used, for example, in electronic devices. Examples of electronic devices include semiconductor devices, MEMS devices, electronic components, printed circuit boards, display devices, and information and communication terminals, which are elements, devices, and final products to which electronic engineering technology is applied. The semiconductor device may be a power semiconductor device through which an operating current flows.

[0202] Figure 1 is a cross-sectional view showing a semiconductor device to which an electronic device according to a preferred embodiment is applied. Figure 2 is a partially enlarged view of the area enclosed by the dashed line in Figure 1. In the following description, the upper part of Figure 1 will be referred to as "upper" and the lower part as "lower".

[0203] The semiconductor device 1 shown in Figure 1 has a so-called package-on-package structure, comprising a through-electrode substrate 2 and a semiconductor package 3 mounted thereon.

[0204] The through-electrode substrate 2 comprises an insulating layer 21, a plurality of through-wirings 221 penetrating from the upper surface to the lower surface of the insulating layer 21, a semiconductor chip 23 embedded inside the insulating layer 21, a lower wiring layer 24 provided on the lower surface of the insulating layer 21, an upper wiring layer 25 provided on the upper surface of the insulating layer 21, and solder bumps 26 provided on the lower surface of the lower wiring layer 24.

[0205] The semiconductor package 3 comprises a package substrate 31, a semiconductor chip 32 mounted on the package substrate 31, bonding wires 33 that electrically connect the semiconductor chip 32 and the package substrate 31, a sealing layer 34 in which the semiconductor chip 32 and the bonding wires 33 are embedded, and solder bumps 35 provided on the lower surface of the package substrate 31.

[0206] The semiconductor package 3 is then stacked on the through-electrode substrate 2. This electrically connects the solder bumps 35 of the semiconductor package 3 to the upper wiring layer 25 of the through-electrode substrate 2.

[0207] As mentioned above, the through-wiring 221 shown in Figure 2 is provided so as to penetrate the insulating layer 21. This electrically connects the lower wiring layer 24 and the upper wiring layer 25, enabling the stacking of the through-electrode substrate 2 and the semiconductor package 3, thereby improving the functionality of the semiconductor device 1.

[0208] The wiring layer 253 included in the upper wiring layer 25 shown in Figure 2 is connected to the through-wiring 221 and solder bumps 35. Therefore, the upper wiring layer 25 is electrically connected to the semiconductor chip 23 and functions as a rewiring layer for the semiconductor chip 23, as well as an interposer between the semiconductor chip 23 and the package substrate 31.

[0209] A resin film formed using the photosensitive resin composition according to the above embodiment can be used, for example, to constitute an insulating layer for a redistribution layer.

[0210] Furthermore, the semiconductor device 1 shown in Figure 1 also includes, in addition to the through-wiring 221, through-wiring 222 provided to penetrate the insulating layer 21 located on the upper surface of the semiconductor chip 23. This enables electrical connection between the upper surface of the semiconductor chip 23 and the upper wiring layer 25.

[0211] [3] Method of Manufacturing Electronic Devices Next, we will explain the method of manufacturing electronic devices. In the following explanation, we will use the method of manufacturing semiconductor device 1 as an example of an electronic device.

[0212] Figure 3 is a process diagram illustrating a method for manufacturing a resin film according to a preferred embodiment. In the following description, an example is given in which the method for manufacturing a resin film according to a preferred embodiment, described later, is applied to the manufacturing of the upper wiring layer 25.

[0213] The method for manufacturing the electronic device according to this embodiment is a method using a resin film manufacturing method according to a preferred embodiment described later. As mentioned above, the resin film is a cured film formed using a photosensitive resin composition.

[0214] The method for manufacturing the resin film shown in Figure 3 includes a coating film forming step S102 in which the aforementioned photosensitive resin composition is applied to a substrate (on the insulating layer 21 and on the semiconductor chip 23) to obtain a photosensitive coating film; a pre-baking step S104 in which the photosensitive coating film is pre-baked; an exposure step S106 in which the pre-baked photosensitive coating film is subjected to an exposure treatment; a developing step S108 in which the photosensitive coating film that has been subjected to the exposure treatment is subjected to a developing treatment; and a curing step S110 in which the photosensitive coating film remaining after development is heated and cured to obtain a resin film.

[0215] According to this method for manufacturing a resin film, a resin film with excellent adhesion to the substrate can be efficiently produced.

[0216] Furthermore, according to the manufacturing method of the electronic device of this embodiment, an electronic device with a resin film that has excellent adhesion to the substrate and excellent reliability can be efficiently manufactured.

[0217] [3-1] Coating film formation step S102: In the coating film formation step, the photosensitive resin composition according to the above embodiment is applied to the substrate to obtain a photosensitive coating film.

[0218] More specifically, first, a varnish-like photosensitive resin composition is applied to the substrate (on the insulating layer 21 and on the semiconductor chip 23). This yields a liquid film of the photosensitive resin composition. Next, the liquid film of the photosensitive resin composition is dried. This yields a photosensitive coating film.

[0219] Since the aforementioned photosensitive resin composition has excellent thick-film coating properties, a thick photosensitive coating can be suitably formed in this process.

[0220] The thickness of the photosensitive coating film formed in this process is not particularly limited, but is preferably 5 μm or more and 50 μm or less, more preferably 10 μm or more and 40 μm or less, and even more preferably 15 μm or more and 30 μm or less.

[0221] This makes it possible to more suitably apply the technology to, for example, the formation of surface protective films and interlayer insulating films for power semiconductor devices.

[0222] The viscosity of the varnish-like photosensitive resin composition is not particularly limited, but is preferably 100 mPa·s to 5000 mPa·s, more preferably 500 mPa·s to 4000 mPa·s, and even more preferably 1000 mPa·s to 3000 mPa·s. This makes it possible to further improve the ability to coat thick films.

[0223] The viscosity of the varnish-like photosensitive resin composition can be determined, for example, by using a cone-plate viscometer (TV-25, manufactured by Toki Sangyo Co., Ltd.) at 23°C and a rotation speed of 100 rpm.

[0224] [3-2] Pre-baking process In the pre-baking process S104, the photosensitive coating is subjected to pre-exposure heat treatment (pre-baking).

[0225] This stabilizes the molecules contained in the photosensitive coating, thereby stabilizing the reaction and increasing contrast in the exposure process S106 described later. As a result, the generation of development residue (scum) in the development process S108 described later can be effectively suppressed.

[0226] The pre-bake temperature is not particularly limited, but is preferably between 100°C and 140°C, and more preferably between 110°C and 130°C.

[0227] This allows for a more favorable achievement of the objective of stabilizing molecules through pre-baking, while also improving the contrast in the exposure process S106, which will be described later.

[0228] The pre-bake time is set appropriately according to the pre-bake temperature, but when pre-baking is performed at the above temperature, it is preferably 1 minute or more and 10 minutes or less, more preferably 2 minutes or more and 8 minutes or less, and even more preferably 3 minutes or more and 6 minutes or less.

[0229] This allows for a more favorable achievement of the objective of stabilizing molecules through pre-baking, while also improving the contrast in the exposure process S106, which will be described later.

[0230] The pre-bake atmosphere is not particularly limited and may include, for example, an inert gas atmosphere or a reducing gas atmosphere, but it is preferable to use air considering work efficiency, etc.

[0231] The atmospheric pressure during pre-baking is not particularly limited and may be under reduced or increased pressure, but atmospheric pressure is preferable considering work efficiency, etc. Atmospheric pressure refers to a pressure of approximately 30 kPa to 150 kPa, and is preferably atmospheric pressure.

[0232] [3-3] Exposure process In the exposure process S106, the pre-baked photosensitive coating is subjected to exposure treatment. For example, a mask is placed on the photosensitive coating and light (active radiation) is irradiated through the mask. This exposes the photosensitive coating according to the pattern of the mask.

[0233] Since the photosensitive coating film formed using the aforementioned photosensitive resin composition has excellent sensitivity, it can be suitably exposed in this process.

[0234] Subsequently, if necessary, the photosensitive coating film that has undergone exposure treatment may be subjected to post-exposure heat treatment.

[0235] [3-4] Development process In the development process S108, the photosensitive coating that has been exposed is subjected to a development process.

[0236] This process develops the photosensitive coating according to the mask pattern, resulting in a patterned photosensitive coating. Examples of developers include organic developers and water-soluble developers.

[0237] [3-5] Curing process In curing process S110, the photosensitive coating film remaining after development is heated and cured (curing treatment). This yields a resin film.

[0238] Since the resin film is formed using the aforementioned photosensitive resin composition, it exhibits excellent adhesion to the substrate.

[0239] The conditions for the curing process are not particularly limited, but they can be set to a heating temperature of 150°C to 380°C for a heating time of 30 minutes to 600 minutes. This allows for more effective suppression of thermal effects on the semiconductor chip 23 while curing the photosensitive coating and obtaining a resin film.

[0240] A wiring layer 253 is formed on the resin film thus created, and then covered with another resin film to obtain an upper wiring layer 25.

[0241] According to the method described above, resin films with highly precise patterning can be manufactured efficiently. Therefore, by using this method for manufacturing resin films, the manufacturing efficiency of electronic devices can be increased.

[0242] Although the photosensitive resin composition, the method for manufacturing a resin film, and the method for manufacturing an electronic device according to the present invention have been described above based on the embodiments, the present invention is not limited to the embodiments described above.

[0243] For example, the method for manufacturing a resin film and an electronic device of the present invention may be modified by adding any desired steps to the above-described embodiment.

[0244] Next, specific examples of the present invention will be described. [4] Preparation of photosensitive resin composition (Examples 1-3, Comparative Examples 1-4) The raw materials shown in Table 1 were blended and stirred at room temperature to obtain a solution. The obtained solution was filtered through a filter with a pore size of 0.2 μm to prepare a varnish-like photosensitive resin composition.

[0245] The ingredients listed in Table 1 are as follows:

[0246] • Polybenzoxazole resin a1: A compound having repeating units represented by the following formula (A-1) (precursor of polybenzoxazole resin (A))

[0247]

[0248] The weight-average molecular weight (Mw) of polybenzoxazole resin a1 was 14,600, and the number-average molecular weight (Mn) was 9,250.

[0249] Method for producing polybenzoxazole resin: 258.2 g (1 mole) of diphenyl ether-4,4'-dicarboxylic acid and 270.3 g (2 moles) of 1-hydroxybenzotriazole were dissolved in N-methylpyrrolidone (1500 g). Then, 412.7 g (2 moles) of dicyclohexylcarbodiimide dissolved in N-methylpyrrolidone (412 g) was added dropwise over 2 hours while maintaining the internal temperature at 0-5°C. After the dropwise addition was complete, the internal temperature was returned to room temperature and the reaction was continued by stirring for another 12 hours.

[0250] After the reaction was complete, the precipitated dicyclohexylcarbodiurea was removed by filtration, and 4000 g of pure water was added dropwise to the resulting filtrate to precipitate crystals.

[0251] These crystals were collected by filtration, washed with 8000 ml of isopropyl alcohol, and then vacuum-dried to obtain 467 g of the dicarboxylic acid derivative.

[0252] 40.87 g (0.083 mol) of the obtained dicarboxylic acid derivative and 36.63 g (0.1 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane were placed in a four-necked separable flask equipped with a thermometer, stirrer, raw material inlet, and dry nitrogen gas inlet tube, and 180.8 g of N-methylpyrrolidone was added to dissolve them. Then, while flowing nitrogen, the temperature was raised to 75°C using an oil bath, and the reaction was carried out at 75°C for 12 hours.

[0253] Next, 5.58 g (0.034 mol) of 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride dissolved in N-methylpyrrolidone (13.0 g) was added, and the mixture was stirred for a further 3 hours. After that, the mixture was cooled to room temperature to complete the reaction.

[0254] Next, the reaction mixture was filtered, then added to a water / isopropyl alcohol = 1 / 3 solution, the precipitate was filtered, thoroughly washed with water, and dried under vacuum to obtain polybenzoxazole resin a1 (a polybenzoxazole resin having an amide bond with repeating units of the above formula (A-1)) as a precursor of polybenzoxazole resin (A).

[0255] • Low molecular weight polyfunctional phenol compound b1: Phloroglucide (5 hydroxyl groups per molecule)

[0256]

[0257] • Low molecular weight polyfunctional phenol compound b2: 2,2'-dihydroxydiphenylmethane (o,o'-BPF) (2 hydroxyl groups per molecule)

[0258]

[0259] • Low molecular weight polyfunctional phenol compound b3: 4,4',4''-trihydroxytriphenylmethane (TrisP-PHBA) (3 hydroxyl groups per molecule)

[0260]

[0261] • Photosensitive agent c1: Naphthoquinone-based photosensitive agent (manufactured by Toyo Gosei Kogyo Co., Ltd., Tek-300) • Photosensitive agent c2: Naphthoquinone-based photosensitive agent (manufactured by Daito Chemix Co., Ltd., GPA-200) • Photosensitive agent c3: Naphthoquinone-based photosensitive agent (manufactured by Daito Chemix Co., Ltd., GPA-250)

[0262] • Adhesion aid d1: KBM-503P, manufactured by Shin-Etsu Chemical Co., Ltd.

[0263]

[0264] • Adhesion aid d2: An adhesion aid having a carboxyl group represented by the following chemical formula.

[0265]

[0266] • Adhesion aid d3: An adhesion aid having a carboxyl group represented by the following chemical formula.

[0267]

[0268] • Adhesion aid d4: Cyclohexylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., CHMS-112)

[0269]

[0270] • Surfactant e1: Polyether-modified polydimethylsiloxane (manufactured by BIC Chemie Japan, BYK-349)

[0271] • Thermal crosslinking agent f1: PXG (paraxylene glycol) • Antioxidant h1: BASF Japan, IRGANOX 1035

[0272] • Solvent g1: GBL (γ-butyrolactone)

[0273] - Other resins (resins other than polybenzoxazole resins) h1: Polyamic acid obtained in the following synthesis example [Synthesis Example 1] Synthesis of polyamic acid In a four-necked flask equipped with a dry nitrogen gas inlet tube, condenser, thermometer, and stirrer, 185.9 g of dehydrated and purified NMP and 11.24 g (0.104 mol) of p-phenyldiamine were placed and stirred for 15 minutes while flowing nitrogen gas. Next, the four-necked flask was placed in an ice water bath, and 43.6 g of dehydrated and purified NMP was added, after which 29.05 g (0.099 mol) of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added dropwise little by little so as not to exceed 50°C. After confirming that the liquid temperature had stabilized below 50°C, the four-necked flask was moved from the ice water bath to an oil bath, the oil bath was heated to 50°C and the reaction mixture was stirred for 16 hours. Furthermore, 1.71 g (0.010 mol) of 5-norbornene-2,3-dicarboxylic acid anhydride and 8.5 g of dehydrated and purified NMP were added to the reaction solution at 50°C, and the mixture was stirred for 3 hours to complete the reaction and obtain a polyamic acid solution.

[0274] [5] Evaluation of the photosensitive resin compositions The photosensitive resin compositions prepared for each of the above examples and comparative examples were evaluated as follows.

[0275] [5-1] A thick-film coating photosensitive resin composition was spin-coated onto a 12-inch silicon wafer to form a liquid film, and then the liquid film was dried to obtain a photosensitive coating.

[0276] Next, the photosensitive coating was pre-baked. The pre-baking conditions were atmospheric pressure and air at 120°C for 4 minutes. This resulted in a photosensitive coating with a thickness of 25 μm.

[0277] A photosensitive coating was peeled from a silicon wafer to obtain a photosensitive film. The film was observed visually and under a microscope. The thick-film coating properties were then evaluated according to the following evaluation criteria.

[0278] ○: No pinholes or uneven film thickness were observed. ×: Pinholes and uneven film thickness were observed.

[0279] [5-2] Sensitivity First, the photosensitive resin composition was rotary coated onto an 8-inch silicon wafer and pre-baked on a hot plate at 120°C for 4 minutes to obtain a thin film A as a photosensitive coating with a thickness of 25 μm.

[0280] This thin film A is subjected to a photomask with a light-shielding rate of 1 to 100%, and a Canon g+h+i-line mask aligner (PLA-501F) is used to apply 1000 mJ / cm² of light. ２ The g+h+i line was exposed with the specified exposure dose.

[0281] After exposure, thin film A was exposed and developed at 23°C with a 0.5% by mass TMAH (tetramethylammonium hydroxide) aqueous solution to obtain thin film B.

[0282] In this process, when developing the obtained thin films A and B so that the film thickness loss (i.e., the difference between the film thickness of thin film A and thin film B) was 3 μm, the minimum exposure amount at which the 20 μm Line & Space opened at 20 μm was defined as the sensitivity. The sensitivity was then evaluated according to the following evaluation criteria.

[0283] ○: Sensitivity is 800 mJ / cm ２ Less than ×: Sensitivity of 800 mJ / cm ２ That's all.

[0284] [5-3] Adhesion (Preparation of Structures) The photosensitive resin compositions of each example and comparative example described above were applied to an 8-inch silicon wafer by spin coating to a dry film thickness of 20 μm, followed by a pre-bake treatment at 120°C for 4 minutes. Then, a resin film made of cured photosensitive resin composition was obtained by heat treatment at 320°C for 30 minutes under a nitrogen atmosphere. Next, 11 cuts were made in the obtained resin film vertically and horizontally at 1 mm intervals using a cutter. In this way, a structure having 100 independent resin films was obtained. Another sample of a structure having 100 independent resin films was obtained using the same method. The following treatment was performed on one of these samples. The obtained structure was subjected to a pressure cooker tester device at 125°C, 100% relative humidity, and 100 hours (pressure cooker treatment). In this way, a structure after being left in an environment of 125°C and 100% humidity for 100 hours was obtained.

[0285] (Evaluation of adhesion) The adhesion of the structures obtained immediately after fabrication and the structures left in an environment of 125°C and 100% humidity for 100 hours was evaluated.

[0286] A peel test was conducted on the resin film of the above structure by thoroughly applying cellophane tape (registered trademark) with an adhesive strength of 3 N / 10 mm or more, and then peeling off the tape. Subsequently, the number of samples in which delamination between the silicon wafer and the resin film occurred was evaluated.

[0287] Then, the adhesion was evaluated based on the number of samples in which delamination occurred, according to the following evaluation criteria.

[0288] ○: Less than 5 samples in either structure exhibit delamination. ×: 5 or more samples in either structure exhibit delamination.

[0289] Furthermore, the adhesion between the resin film and the copper plate, and the adhesion between the resin film and the aluminum plate were evaluated in the same manner as described above, except that copper plates and aluminum plates were used instead of silicon wafers. These results, along with the conditions of the photosensitive resin compositions for each of the above examples and comparative examples, are summarized in Table 1. The viscosity values ​​in Table 1 were measured at 23°C using a cone-plate viscometer (TV-25, manufactured by Toki Sangyo Co., Ltd.) at a rotation speed of 100 rpm.

[0290]

[0291] As shown in Table 1, the present invention yielded excellent results, whereas the comparative examples did not yield satisfactory results.

[0292] According to the present invention, it is possible to provide a photosensitive resin composition that can be used to form a photosensitive coating film with excellent thick-film coating properties and excellent sensitivity to exposure light, and a resin film with excellent adhesion to a substrate, a method for manufacturing a resin film using the photosensitive resin composition, and a method for manufacturing an electronic device using the method for manufacturing the resin film. Therefore, the present invention has industrial applicability.

[0293] 1 Semiconductor device 2 Through-electrode substrate 3 Semiconductor package 21 Insulating layer 23 Semiconductor chip 24 Lower wiring layer 25 Upper wiring layer 26 Solder bump 31 Package substrate 32 Semiconductor chip 33 Bonding wire 34 Encapsulation layer 35 Solder bump 221 Through-wiring 222 Through-wiring 253 Wiring layer S102 Coating film formation process S104 Pre-bake process S106 Exposure process S108 Development process S110 Curing process

Claims

1. A photosensitive resin composition characterized by containing a polybenzoxazole resin, a low molecular weight polyfunctional phenol compound having multiple hydroxyl groups in its molecule, a photosensitive agent, and an adhesion aid.

2. The photosensitive resin composition according to claim 1, wherein the low molecular weight polyfunctional phenol compound is at least one of the compounds represented by the following formulas (1) to (3).

3. The photosensitive resin composition according to claim 1 or 2, wherein the adhesion aid comprises a silane compound.

4. The photosensitive resin composition according to claim 3, wherein the adhesion aid is at least one selected from the compounds represented by the following formula (4) to formula (7).

5. The photosensitive resin composition according to claim 1 or 2, wherein the content of the low molecular weight polyfunctional phenol compound is 0.5 parts by mass or more and 5.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

6. The photosensitive resin composition according to claim 1 or 2, wherein the content of the adhesion aid is 1.0 part by mass or more and 10.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

7. The photosensitive resin composition according to claim 1 or 2, wherein the content of the photosensitive agent is 7.0 parts by mass or more and 25.0 parts by mass or less per 100 parts by mass of the polybenzoxazole resin.

8. A method for producing a resin film, comprising the steps of: applying the photosensitive resin composition according to claim 1 or 2 to a substrate to obtain a photosensitive coating film; pre-baking the photosensitive coating film; subjecting the pre-baked photosensitive coating film to an exposure treatment; subjecting the exposure-treated photosensitive coating film to a development treatment; and heating and curing the photosensitive coating film remaining after development to obtain a resin film.

9. A method for manufacturing an electronic device, characterized by using the method for manufacturing a resin film described in claim 8.

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