Photosensitive resin composition and method for producing cured relief pattern

Abstract

Provided is a photosensitive resin composition which is used in a panel level packaging process, the photosensitive resin composition containing: (A) at least one selected from the group consisting of (A-1) a polyimide precursor and (A-2) a polyimide; (B) a photopolymerization initiator; and (C) an organic solvent. The (C) organic solvent contains at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, and the viscosity measured with an E-type viscometer at 23°C is 0.02-1.5 Pa∙s.

Description

Method for producing a photosensitive resin composition and a cured relief pattern

[0001] This disclosure relates to a photosensitive resin composition and a method for producing a cured relief pattern, etc.

[0002] Conventionally, polyimide resins possessing excellent heat resistance, electrical properties, and mechanical properties have been used as insulating materials for electronic components, as well as for passivation films, surface protective films, and interlayer insulating films of semiconductor devices. Among these polyimide resins, those provided in the form of photosensitive polyimide precursor compositions allow for the easy formation of heat-resistant relief pattern films through thermal imidization treatment by coating, exposure, development, and curing of the composition. Such photosensitive polyimide precursor compositions have the advantage of significantly shortening the process compared to conventional non-photosensitive polyimide materials.

[0003] Incidentally, semiconductor devices (hereinafter also referred to as "devices") are mounted on printed circuit boards in various ways depending on the purpose. Conventionally, devices were generally manufactured using the wire bonding method, in which thin wires are connected from the external terminals (pads) of the device to the lead frame. However, with the increasing speed of devices and the fact that operating frequencies have reached gigahertz (GHz), differences in the wiring length of each terminal during mounting now affect the operation of the device. Therefore, in mounting devices for high-end applications, it has become necessary to precisely control the length of the mounting wiring, and wire bonding has become difficult to meet this requirement.

[0004] Therefore, flip-chip mounting has been proposed, in which a redistribution layer is formed on the surface of a semiconductor chip, bumps (electrodes) are formed on top of it, and then the chip is flipped over and directly mounted on a printed circuit board. Because this flip-chip mounting allows for precise control of the wiring distance, it has been adopted for high-end devices that handle high-speed signals, and because of its small mounting size, it has been adopted for mobile phones and the like, and demand is rapidly expanding. Furthermore, recently, a semiconductor chip mounting technology called fan-out wafer-level packaging (FOWLP) has been proposed, in which individual chips are manufactured by dicing a wafer that has undergone pre-processing, the individual chips are reconstructed on a support and sealed with molding resin, and then the redistribution layer is formed after peeling off the support (for example, Patent Document 1). FOWLP has the advantage of being able to reduce the height of the package and achieve high-speed transmission or cost reduction.

[0005] In recent years, panel-level packages (PLPs) have been attracting attention due to the increasing size of semiconductor chips and packages.

[0006] Japanese Patent Publication No. 2005-167191

[0007] However, since panel-level packages use large rectangular panel substrates, the spin coaters used in conventional wafer-level packages cannot be used, and slit coaters or the like must be used. Conventional photosensitive resin compositions for wafer-level packages have the problem of not being able to be slit coated.

[0008] Furthermore, unlike wafer-level processes, panel-level processes require vacuum drying steps such as VCD or HVCD, which presented a problem of reduced film thickness uniformity.

[0009] Furthermore, as the panels became larger, problems arose where cracks would form in the cured film or the cured film would peel off from the substrate if the resin composition coated on the substrate underwent further heating processes such as reflow after heat curing.

[0010] Therefore, the present disclosure aims to provide a photosensitive resin composition that can be coated by slit coating in a panel-level process, provides a photosensitive resin layer with good thickness uniformity, and yields a cured film with suppressed cracking or peeling from the substrate, and a method for producing a cured relief pattern using the photosensitive resin composition.

[0011] The present inventors have found that the above problems can be solved by combining a polyimide precursor, a photopolymerization initiator, and a specific solvent to achieve a specific viscosity range. Examples of embodiments of the present disclosure are listed below. <1> A photosensitive resin composition used in a panel-level packaging process, comprising: (A) at least one selected from the group consisting of (A-1) a polyimide precursor and (A-2) a polyimide; (B) a photopolymerization initiator; and (C) an organic solvent, wherein the (C) organic solvent comprises at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, and the viscosity measured with an E-type viscometer at 23°C is 0.02 to 1.5 Pa·s. <2> The photosensitive resin composition according to item 1, wherein the (C) organic solvent does not contain, or contains in less than 10% by mass, a solvent having a boiling point of 160°C or lower, based on the total mass of the (C) organic solvent. <3> The photosensitive resin composition according to item 1 or 2, wherein the (C) organic solvent contains in more than 90% by mass of at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, based on the total mass of the (C) organic solvent. <4> The photosensitive resin composition according to any one of items 1 to 3, wherein the (C) organic solvent is at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N,N-dimethylpropanamide. <5> The (A-1) polyimide precursor is the following general formula (1): {In formula (1), X １is a tetravalent organic group having 4 to 40 carbon atoms, and Y １ is a divalent organic group having 6 to 40 carbon atoms, and n １ is an integer from 2 to 150, and R １ and R ２ each independently represent a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms}, the photosensitive resin composition according to any one of Items 1 to 4 having a structure represented by. <6> The R １ , and at least one of the R ２ is a monovalent organic group having 1 to 40 carbon atoms, the photosensitive resin composition according to Item 5. <7> The X １ is at least one selected from the group consisting of the following general formulas (2) to (4): The photosensitive resin composition according to Item 5. <8> The Y １ is at least one selected from the group consisting of the following general formulas (5) to (7): The photosensitive resin composition according to Item 5. <9> The X １ is the following general formula (2): and the Y １ is the following general formula (6): The photosensitive resin composition according to Item 6. <10> The X １ is the following general formula (3): and the Y １ is the following general formula (5): The photosensitive resin composition according to Item 6. <11> The X １ is the following general formula (3): and the Y １ is the following general formula (7): The photosensitive resin composition described in item 6. <12> The photosensitive resin composition described in any of items 1 to 11, wherein the (A-2) polyimide does not contain a fluorine atom. <13> The photosensitive resin composition described in any of items 1 to 12, further comprising (D) a nitrogen-containing heterocyclic compound. <14> The photosensitive resin composition described in any of items 1 to 12, further comprising (E) a photopolymerizable unsaturated monomer. <15> The photosensitive resin composition described in any of items 1 to 13, wherein the (B) photopolymerization initiator is an oxime compound. <16> A method for producing a polyimide, comprising the step of curing the photosensitive resin composition described in any of items 1 to 15 to form a polyimide. <17> The photosensitive resin composition described in any of items 1 to 15, used for development with a developer in which 90% or more by mass of the developer is an organic solvent. <18> A method for producing a cured relief pattern, comprising the following steps: (1) applying a photosensitive resin composition according to any of items 1 to 15 to a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer to light; (3) developing the photosensitive resin layer after exposure to form a relief pattern; and (4) heat-treating the relief pattern to form a cured relief pattern. <16> A method for producing a polyimide-containing cured product, comprising curing a photosensitive resin composition according to any of items 1 to 12 to form a polyimide-containing cured product.

[0012] This disclosure provides a photosensitive resin composition that can be coated by slit coating in a panel-level process, provides a photosensitive resin layer with good film thickness uniformity, and thereby enables a coated film with good film thickness uniformity, resulting in a cured film with suppressed cracking and peeling from the substrate, and a method for manufacturing a cured relief pattern using the photosensitive resin composition.

[0013] <Photosensitive Resin Composition> The photosensitive resin composition of the present disclosure includes: (A) at least one selected from the group consisting of a polyimide precursor and a soluble polyimide; (B) a photoinitiator; and (C) an organic solvent, wherein the (C) organic solvent is at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, and has a viscosity measured by an E-type viscometer at 23°C of 0.02 to 1.5 Pa·s (i.e., 0.2 to 15 P).

[0014] The photosensitive resin composition of the present disclosure can be used in a panel-level packaging process. In the panel-level process, slit coating is possible, providing a photosensitive resin layer with good film thickness uniformity, and thus enabling a coated film with good film thickness uniformity, and a cured film with suppressed cracks or peeling from the substrate can be obtained.

[0015] In one embodiment, the photosensitive resin composition can include 0.5 to 20 parts by mass of (B) a photoinitiator and 300 to 800 parts by mass of (C) an organic solvent with respect to 100 parts by mass of at least one selected from the group consisting of (A) a polyimide precursor and a soluble polyimide.

[0016] (A-1) Polyimide Precursor The polyimide precursor according to this embodiment is not limited as long as it is a precursor that becomes a polyimide by cyclization, but is preferably a structure represented by the following general formula (1): {In formula (1), X １ is a tetravalent organic group having 4 to 40 carbon atoms, Y １ is a divalent organic group having 6 to 40 carbon atoms, n １ is an integer of 2 to 150, and R １ and R ２ each independently represent a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms}

[0017] In the general formula (1) above, the organic group may be an organic group containing heteroatoms other than carbon and hydrogen, or an organic group consisting of carbon and hydrogen atoms. Examples of heteroatoms include nitrogen atoms, oxygen atoms, and sulfur atoms.

[0018] In the above general formula (1), R １ and R ２ At least one of the groups is preferably a monovalent organic group having 1 to 40 carbon atoms, and more preferably a group further comprising a polymerizable group selected from the group consisting of acid polymerizable groups, base polymerizable groups, and radical polymerizable groups. Here, acid polymerizable groups, base polymerizable groups, and radical polymerizable groups refer to groups that can be polymerized by the action of an acid, a base, or a radical, respectively.

[0019] Total R according to this embodiment １ and R ２ From the viewpoint of resolution, the content of monovalent organic groups having 1 to 40 carbon atoms is preferably 40 mol% or more, more preferably 60 mol% or more, particularly preferably 80 mol% or more, and even more preferably 90 mol% or more.

[0020] In the above general formula (1), R １ and R ２ At least one of them is given by the following general formula (15): {In the formula, L １ , L ２ and L ３ Each is independently a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and m １ It is preferable that the group is a monovalent organic group represented by { which is an integer between 2 and 10}.

[0021] n in general formula (1) １ While not limited to integers between 2 and 150, integers between 3 and 100 are preferred, and integers between 5 and 70 are more preferred, from the viewpoint of the photosensitive properties and mechanical properties of the photosensitive resin composition.

[0022] (A-1) Method for preparing polyimide precursor (A-1) The polyimide precursor is the tetravalent organic group X mentioned above １A tetracarboxylic dianhydride containing the above is reacted with photopolymerizable alcohols having unsaturated double bonds and optionally alcohols without unsaturated double bonds to prepare a partially esterified tetracarboxylic acid (hereinafter also called an acid / ester), and then this is reacted with the aforementioned divalent organic group Y １ It is obtained by amide polycondensation with diamines containing [the specified compound].

[0023] (Preparation of Acid / Ester Compounds) In this embodiment, a tetravalent organic group X is preferably used to prepare the (A-1) polyimide precursor. １ Examples of tetracarboxylic dianhydrides containing the above include pyromellitic anhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, diphenyl sulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane.

[0024] Among these, pyromellitic anhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, and biphenyl-3,3',4,4'-tetracarboxylic dianhydride are preferred, but the product is not limited to these. These may be used individually or in combination of two or more.

[0025] Among the structures derived from the tetracarboxylic dianhydrides listed above, X is considered to have the following characteristics in terms of cracking and delamination of the resulting polyimide from the substrate, as well as glass transition temperature (Tg) and resolution. １ The following general formulas (2) to (4): It is preferable that the structure is at least one selected from the group consisting of the following.

[0026] In this embodiment, suitable photopolymerizable alcohols having unsaturated double bonds for preparing (A-1) polyimide precursors include, for example, 2-acryloyloxyethyl alcohol, 1-acryloyloxy-3-propyl alcohol, 2-acrylamidoethyl alcohol, methylol vinyl ketone, 2-hydroxyethyl vinyl ketone, 2-hydroxy-3-methoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-t-butoxypropyl acrylate, and 2-hydroxy-3-cyclohexyl acrylate. Examples include cypropyl acrylate, 2-methacryloyloxyethyl alcohol, 1-methacryloyloxy-3-propyl alcohol, 2-methacrylamidoethyl alcohol, methylol vinyl ketone, 2-hydroxyethyl vinyl ketone, 2-hydroxy-3-methoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-t-butoxypropyl methacrylate, 2-hydroxyethyl methacrylate (HEMA), and 2-hydroxy-3-cyclohexyloxypropyl methacrylate.

[0027] In addition to the above-mentioned photopolymerizable alcohols having unsaturated double bonds, alcohols without unsaturated double bonds, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, neopentyl alcohol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, 3-octanol, 1-nonanol, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, and benzyl alcohol, can also be used in combination with a portion of these alcohols.

[0028] Furthermore, as a polyimide precursor, a non-photosensitive polyimide precursor prepared solely from alcohols that do not have the above-mentioned unsaturated double bonds may be used in combination with the (A-1) photosensitive polyimide precursor according to this embodiment. From the viewpoint of resolution, it is preferable that the non-photosensitive polyimide precursor is 200 parts by mass or less, based on 100 parts by mass of the (A-1) photosensitive polyimide precursor according to this embodiment.

[0029] By stirring and dissolving the above-mentioned suitable tetracarboxylic dianhydride and the above-mentioned alcohols in a solvent as described later, in the presence of a basic catalyst such as pyridine, at a temperature of 20 to 50°C for 4 to 10 hours, and then mixing them, the esterification reaction of the acid dianhydride proceeds, and the desired acid / ester product can be obtained.

[0030] (Preparation of Polyimide Precursor) The above acid / ester compound (typically an acid / ester compound existing in solution in a solvent described later) was mixed with a suitable dehydrating condensation agent, such as dicyclohexylcarbodiimide, 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1,1-carbonyldioxy-di-1,2,3-benzotriazole, and N,N'-disuccinimidyl carbonate, under ice cooling to obtain a polyacid anhydride from the acid / ester compound. A divalent organic group Y was added to the polyacid anhydride from the acid / ester compound. １ By adding a diamine containing the specified substance, dissolved or dispersed in a separate solvent, dropwise, and performing amide polycondensation, the desired polyimide precursor can be obtained.

[0031] Alternatively, the desired polyimide precursor can be obtained by acid-chloridizing the acid portion of the above acid / ester compound using thionyl chloride or the like, and then reacting it with a diamine compound in the presence of a base such as pyridine.

[0032] Divalent organic group Y is preferably used in this embodiment １Examples of diamines containing these include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3 '-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4-bis(4 -aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2 -Bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, ortho-tolidine sulfone, 9,9-bis(4-aminophenyl)fluorene, and those in which some of the hydrogen atoms on the benzene ring are substituted with methyl groups, ethyl groups, hydroxymethyl groups, hydroxyethyl groups, halogens, etc., for example, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,Examples include, but are not limited to, 2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyloxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, and mixtures thereof.

[0033] Among the structures derived from the diamines listed above, Y is the most important in terms of the high Tg and resolution of the resulting polyimide resin. １ For example, the following general formulas (5) to (7): At least one selected from the group consisting of structures represented by is preferred.

[0034] Among the combinations of structures represented by the above general formulas (2) to (7), X １ The above general formula (2) is Y １ If the above general formula (6) is true; X １ This is the general formula (3), and Y １ If it is the general formula (5); or X １ This is the general formula (3), and Y １ The case where the formula is general formula (7) is more preferable.

[0035] After the amide polycondensation reaction is complete, any water-absorbing by-products of the dehydrating condensation agent present in the reaction solution are filtered off as needed. Then, a poor solvent such as water, an aliphatic lower alcohol, or a mixture thereof is added to the obtained polymer component to precipitate it. Further purification of the polymer is performed by repeating the redissolution and reprecipitation operations, and the polymer is then vacuum-dried to isolate the target polyimide precursor. To improve the degree of purification, the solution of this polymer may be passed through a column packed with anion and / or cation exchange resin swollen with a suitable organic solvent to remove ionic impurities.

[0036] The molecular weight of the (A-1) polyimide precursor described above is preferably 8,000 to 150,000, and more preferably 9,000 to 50,000, when measured by weight-average molecular weight in polystyrene equivalent by gel permeation chromatography. When the weight-average molecular weight is 8,000 or more, the mechanical properties are good, and when it is 150,000 or less, the dispersibility in the developer is good and the resolution performance of the relief pattern is good. Tetrahydrofuran and N-methyl-2-pyrrolidone are recommended as developing solvents for gel permeation chromatography. The weight-average molecular weight is determined from a calibration curve prepared using standard monodisperse polystyrene. As the standard monodisperse polystyrene, it is recommended to select from the organic solvent-based standard sample STANDARD SM-105 manufactured by Showa Denko Corporation.

[0037] (A-2) Polyimide The (A-2) polyimide in this embodiment is not limited as long as it can be dissolved in a general organic solvent, and may be a soluble polyimide. Preferably, the (A-2) polyimide is soluble in 5% by mass or more in at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide used in this embodiment.

[0038] The soluble polyimide (A-2) according to this embodiment is not limited as long as it can be dissolved in a general organic solvent, but it is preferable that it does not contain fluorine atoms from the viewpoint of chemical resistance and elongation.

[0039] In this embodiment, the (A-2) soluble polyimide preferably has photopolymerizable functional groups at the ends of the main chain and / or on the side chains of the main chain, from the viewpoint of chemical resistance. The presence of photopolymerizable functional groups in the soluble polyimide can improve resolution.

[0040] Here, the photopolymerizable functional group is not limited as long as it is a functional group that can be polymerized by light irradiation. Examples of such functional groups include methacryloyl group, acryloyl group, methacrylamide group, acrylamide group, and styryl group. From the viewpoint of resolution, at least one selected from the group consisting of methacryloyl group, acryloyl group, and styryl group is preferred.

[0041] In this embodiment, the main chain end refers to the terminal structure of a soluble polyimide main chain composed of an acidic dianhydride and a diamine. The method for introducing photopolymerizable functional groups to the polyimide main chain ends is not particularly limited. Photopolymerizable functional groups can be introduced to the acidic dianhydride and / or diamine before polycondensation of the acidic dianhydride and diamine, or photopolymerizable functional groups can be introduced to the main chain end structure after obtaining a soluble polyimide.

[0042] The soluble polyimide (A-2) according to this embodiment is given by the following general formula (8): It can be expressed as {In formula (8), X represents a tetravalent organic group having 4 to 32 carbon atoms, and Y represents a divalent organic group having 4 to 40 carbon atoms}.

[0043] In general formula (8), X is not limited to any tetravalent organic group having 4 to 32 carbon atoms, but from the viewpoint of chemical resistance, it is preferable that X has 6 or more carbon atoms, more preferably 8 or more, and particularly preferable 10 or more. From the viewpoint of resolution, the number of carbon atoms in X is preferably 30 or less, more preferably 28 or less, and particularly preferable 26 or less.

[0044] In general formula (8), Y is not limited to any divalent organic group having 4 to 40 carbon atoms, but from the viewpoint of chemical resistance, it is preferable that Y has 6 or more carbon atoms, more preferably 8 or more, and particularly preferable 10 or more. From the viewpoint of resolution, the number of carbon atoms in Y is preferably 30 or less, more preferably 28 or less, and particularly preferable 26 or less.

[0045] In this embodiment, X preferably contains an aromatic group, and is defined by the following general formulas (9) to (14): It is more preferable to include at least one selected from the group consisting of structures represented by formulas (9) and (13). The tetravalent bonds of the structures represented by formulas (9) and (13) can be determined, for example, from tetracarboxylic dianhydrides represented by the following general formulas (2T) and (6T).

[0046] From the viewpoint of the glass transition temperature (Tg) after heat curing, it is preferable that X in this embodiment includes at least one selected from the group consisting of structures represented by formulas (10) and (11). From the viewpoint of elongation after heat curing, it is preferable that it includes at least one selected from the group consisting of structures represented by formulas (9) and (12). From the viewpoint of resolution, it is preferable that X in this embodiment includes the structure represented by formula (14).

[0047] Y in this embodiment preferably has an aromatic group, and is defined by the following general formulas (16), (17), and (18): It is more preferable to include at least one selected from the group consisting of structures represented by formulas (17) and (18). The divalent bonds of the structures represented by formulas (17) and (18) can be determined, for example, from diamines represented by the following general formulas (9D) and (7D).

[0048] (A-2) Method for preparing soluble polyimide (A-2) The method for preparing soluble polyimide (A-2) is to polycondense a tetracarboxylic dianhydride containing the aforementioned tetravalent organic group X with a diamine containing the aforementioned divalent organic group Y to obtain a polyamic acid, and then heat-treat it to obtain soluble polyimide (A-2).

[0049] (Preparation of polyamic acid) (A-2) A tetracarboxylic dianhydride containing a tetravalent organic group X is suitably used to prepare polyamic acid, which is a precursor of soluble polyimide, and is given by the following formula (1T): A compound represented by the above formula (1T) {wherein X is as defined in the above general formula (8)} is preferred.

[0050] Examples of tetracarboxylic dianhydrides include pyromellitic dianhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride (also known as oxydiphthalic acid dianhydride, abbreviated as "ODPA"), benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride (abbreviated as "BPDA"), diphenyl sulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane.

[0051] Preferably, examples of tetracarboxylic dianhydrides include pyromellitic dianhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, and biphenyl-3,3',4,4'-tetracarboxylic dianhydride, as well as tetracarboxylic dianhydrides represented by the following general formulas (2T) to (7T), but are not limited to these. These may be used individually or in combination of two or more. Among these, the following general formulas (2T) to (7T): Tetracarboxylic acid dianhydrides represented by are preferred.

[0052] Diamines containing a divalent organic group Y include those with the following formula (1D): H ２ N-Y-NH ２ A compound represented by (1D) {wherein Y is as defined in the general formula (8) above} is preferred.

[0053] Examples of diamines include p-phenylenediamine (abbreviated as "pPD"), m-phenylenediamine, 4,4'-diaminodiphenyl ether (abbreviated as "4,4'-DADPE", also known as 4,4'-oxydianiline, abbreviated as "ODA"), 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, and 3,3'-diamine. Nodiphenylsulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl (abbreviated as "m-TB"), 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3 -aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 2,2-bis(4- (Aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, ortho-tolidine sulfone and 9,9-bis(4-aminophenyl)fluorene, etc., and those in which some of the hydrogen atoms on the benzene ring are substituted with methyl groups, ethyl groups, hydroxymethyl groups, hydroxyethyl groups, halogens, etc., for example, 3,Examples include, but are not limited to, 3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyltoxy-4,4'-diaminobiphenyl, and 3,3'-dichloro-4,4'-diaminobiphenyl, as well as diamines represented by the following general formulas (7D) to (9D). These can be used individually or mixed in groups of two or more. Among these, the following formulas (7D) to (9D): A diamine represented by is preferred.

[0054] Polyamic acid can be obtained by dissolving and mixing the above-mentioned tetracarboxylic dianhydride and the above-mentioned diamine in a solvent described later. For example, the reaction conditions involve stirring continuously for 4 to 10 hours at a temperature of 10 to 50°C.

[0055] The resulting polyamic acid can be isolated and then subjected to an imidation reaction, or it can be subjected to the next imidation reaction without isolation.

[0056] (Preparation of Soluble Polyimide) The polyamic acid obtained above can be reacted at high temperature with an imidation catalyst added as needed to obtain soluble polyimide. Preferably, this can be done by mixing toluene or xylene, which are azeotropic solvents with water, in a glass container equipped with a Dean-Stark apparatus. The reaction conditions are not limited as long as the desired soluble polyimide can be obtained, but for example, stirring is continued for 4 to 10 hours at a reaction temperature of 150 to 230°C.

[0057] After the soluble polyimide reaction is complete and the mixture has cooled to near room temperature, the resulting polymer component can be added to a poor solvent to precipitate it. Furthermore, the polymer can be purified by repeating the redissolution and reprecipitation operations. After the purification of the polymer, the desired soluble polyimide can be isolated by vacuum drying. To improve the degree of purification, the solution of this polymer may be passed through a column packed with an anion exchange resin, a cation exchange resin, or both of these swollen with a suitable organic solvent, to remove ionic impurities.

[0058] (A-2) The molecular weight of the soluble polyimide is preferably 8,000 to 150,000, and more preferably 9,000 to 50,000, when measured by the weight-average molecular weight in terms of polystyrene by gel permeation chromatography. When the weight-average molecular weight is 8,000 or more, the mechanical properties are good, and when it is 150,000 or less, the dispersibility in the developer is good and the resolution performance of the relief pattern is good. Tetrahydrofuran and N-methyl-2-pyrrolidone are recommended as the developing solvent for gel permeation chromatography. The weight-average molecular weight of (A-2) the soluble polyimide is measured by the method described in the examples.

[0059] The soluble polyimide according to this embodiment is given by the following formulas (22) to (24): Examples include structures that include at least one of the structures represented by as a repeating unit.

[0060] (B) Photopolymerization initiator The photosensitive resin composition of this disclosure comprises (B) a photopolymerization initiator. The photopolymerization initiator is preferably a photoradical polymerization initiator or a photoacid generator.

[0061] Examples of photoradical polymerization initiators include benzophenone compounds such as benzophenone, o-benzoylmethyl benzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and fluorenone; acetophenone compounds such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, and 1-hydroxycyclohexylphenyl ketone; thioxanthone compounds such as thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, and diethylthioxanthone; benzyl compounds such as benzyl, benzyldimethyl ketal, and benzyl-β-methoxyethyl acetal; benzoin compounds such as benzoin and benzoin methyl ether; 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, and 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime. Examples of oxime compounds include oxime compounds such as vonyl oxime, 1-phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime, 1,2-propanedione-3-cyclopentyl-1-[4-(phenylthio)phenyl]-2-(o-benzoyl oxime), and 3-cyclopentyl-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]propanone-1-(o-acetyloxime); N-arylglycine compounds such as N-phenylglycine; peroxides such as benzoyl perchloride, aromatic biimidazole compounds, and titanocene compounds.

[0062] Examples of preferred photoacid generators include α-(n-octanesulfonyloxyimino)-4-methoxybenzylcyanide.

[0063] (B) The photopolymerization initiator is not limited to the examples given above. Among the above photopolymerization initiators, photoradical polymerization initiators are more preferred, and oxime compounds are even more preferred in terms of photosensitivity.

[0064] In terms of resolution, oxime compounds are defined by the following general formulas (19), (20), and (21): {In the formula, Ra represents a monovalent organic group having 1 to 10 carbon atoms, Rb represents a monovalent organic group having 1 to 20 carbon atoms, Rc represents a monovalent organic group having 1 to 10 carbon atoms, and Rd represents a monovalent organic group having 1 to 10 carbon atoms.} {In the formula, Re represents a monovalent organic group having 1 to 20 carbon atoms, and Rf represents a monovalent organic group having 1 to 10 carbon atoms.} It is preferable that the element is at least one selected from the group consisting of {wherein Rg represents a monovalent organic group having 1 to 20 carbon atoms, Rh represents a monovalent organic group having 1 to 10 carbon atoms, and Ri represents a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms}.

[0065] In general formula (19), Ra is not limited to any monovalent organic group having 1 to 10 carbon atoms, but from the viewpoint of heat resistance, it is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, or a propyl group. Rb is not limited to any monovalent organic group having 1 to 20 carbon atoms, but from the viewpoint of resolution, it is preferably a monovalent organic group derived from an aromatic group having 6 to 20 carbon atoms or a heterocyclic compound having 5 to 20 carbon atoms. Rc is not limited to any monovalent organic group having 1 to 10 carbon atoms, and among these, from the viewpoint of resolution, a monovalent organic group containing a saturated alicyclic structure having 3 to 10 carbon atoms is preferred. Rd is not limited to any monovalent organic group having 1 to 10 carbon atoms, and among these, from the viewpoint of resolution, an organic group having 1 to 3 carbon atoms is preferred, and more preferably a methyl group, an ethyl group, or a propyl group.

[0066] In general formula (20), Re is not limited to any monovalent organic group having 1 to 20 carbon atoms, but from the viewpoint of resolution, it is preferably an organic group having 5 to 20 carbon atoms, and more preferably an organic group having 6 to 15 carbon atoms. Rf is not limited to any monovalent organic group having 1 to 10 carbon atoms, but from the viewpoint of resolution, it is preferably an organic group having 1 to 3 carbon atoms, and more preferably a methyl group, an ethyl group, or a propyl group.

[0067] In general formula (21), Rg is not limited to any monovalent organic group having 1 to 20 carbon atoms, but from the viewpoint of heat resistance, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, or a propyl group is more preferred. Rh is not limited to any monovalent organic group having 1 to 10 carbon atoms, but from the viewpoint of resolution, a group having 2 to 9 carbon atoms is preferred, and a group having 2 to 8 carbon atoms is more preferred. Ri is not limited to a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, but from the viewpoint of resolution, a hydrogen atom or a monovalent organic group having 1 to 9 carbon atoms is preferred.

[0068] Among the general formulas (19) to (21), the structure represented by general formula (19) or (20) is more preferable in terms of resolution.

[0069] (B) The content of the photopolymerization initiator is preferably 0.5 parts by mass or more and 20 parts by mass, based on 100 parts by mass of at least one resin selected from the group consisting of (A) (A-1) polyimide precursor and (A-2) polyimide. By setting the content of (B) photopolymerization initiator to 0.5 parts by mass or more, the photoreaction is initiated, while by setting it to 20 parts by mass or less, film degradation of the cured film is suppressed. From this viewpoint, the content of (B) photopolymerization initiator is more preferably 1 part by mass or more and 15 parts by mass or less, more preferably 2 parts by mass or more and 12 parts by mass or less, and particularly preferably 3 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide.

[0070] (C) Organic solvent The (C) organic solvent according to this embodiment comprises at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide. It may comprise only one or two or more selected from the above group.

[0071] The content of at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide is preferably 50% by mass or more, more preferably 70% by mass or more, particularly preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably more than 90% by mass, based on the total mass of the organic solvent (C). When two or more selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide are included, it is preferable that the total content is within the above numerical range. For example, based on the total mass of the organic solvent (C), it may contain 50% by mass of N-ethyl-2-pyrrolidone and 45% by mass of 1,3-dimethyl-2-imidazolidinone, for a total of 95% by mass (i.e., more than 90% by mass). The upper limit of the total content of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide in the organic solvent (C) is not limited, but for example, based on the total mass of the organic solvent (C), it may be 100% by mass or less, less than 100% by mass, or 99% by mass or less.

[0072] In this embodiment, from the viewpoint of uniform film thickness, it is preferable that the solvent having a boiling point of 160°C or lower is not included or is included in an amount of less than 10% by mass, based on the total mass of the organic solvent (C). The content of the solvent having a boiling point of 160°C or lower is more preferably less than 8% by mass, even more preferably less than 6% by mass, particularly preferably less than 4% by mass, and even more preferably less than 2% by mass, based on the total mass of the organic solvent (C).

[0073] By including a predetermined amount of (C) organic solvent in the photosensitive resin composition as described above, not only are polyimide precursors, soluble polyimide, photopolymerization initiators, and other components uniformly dispersed and dissolved, but the viscosity at 23°C according to this embodiment can be easily adjusted to a range of 0.02 to 1.5 Pa·s (i.e., 0.2 to 15 P), preferably to a range of 0.5 to 15 P.

[0074] The reason why including the above-mentioned (C) organic solvent enables slit coating of the photosensitive resin composition, resulting in a cured film with excellent film thickness uniformity and no cracking or peeling from the substrate after thermal history is not clear, but the inventors believe it to be as follows: The above-mentioned (C) organic solvent dissolves the polyimide precursor, soluble polyimide and / or photopolymerization initiator, and by bringing it to a suitable viscosity range, it is possible to coat it uniformly without leakage, clogging, etc., during slit coating. Furthermore, compared to N-methyl-2-pyrrolidone (boiling point: 202°C) and γ-butyrolactone (boiling point: 204°C), which are commonly used in wafer-level processes, these materials have higher boiling points (N-ethyl-2-pyrrolidone, boiling point: 218°C; 1,3-dimethyl-2-imidazolidinone, boiling point: 220°C; 3-methoxy-N,N-dimethylpropanamide, boiling point: 215°C; 3-butoxy-N,N-dimethylpropanamide, boiling point: 252°C). As a result, bumping during the vacuum drying process is less likely to occur, and film thickness uniformity tends to be good. In addition, by using the aforementioned suitable polyimide precursors, the coefficient of linear expansion of the resulting cured film is sufficiently low. Therefore, even when using large substrates, residual stress resulting from a mismatch in the coefficient of linear expansion is reduced, which tends to suppress cracking or delamination from the substrate.

[0075] (C) As for the organic solvent, from the viewpoint of resolution and film thickness uniformity, at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N,N-dimethylpropanamide is preferred, and N-ethyl-2-pyrrolidone is particularly preferred.

[0076] The content of the (C) organic solvent in this embodiment is preferably 300 to 800 parts by mass per 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide. If the content of the (C) organic solvent is 300 parts by mass or more, the polyimide precursor, soluble polyimide, and photopolymerization initiator can be dissolved, and if it is 800 parts by mass or less, the film thickness required for an insulating film can be obtained. The lower limit of the content of the (C) organic solvent is more preferably 350 parts by mass or more, even more preferably 400 parts by mass or more, and particularly preferably 450 parts by mass or more, per 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide. The upper limit of the content of the (C) organic solvent is more preferably 750 parts by mass or less, even more preferably 700 parts by mass or less, and particularly preferably 650 parts by mass or less, per 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide.

[0077] The resin composition according to this embodiment may contain other solvents in addition to N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, to the extent that it does not adversely affect performance. Examples of other solvents include amides, sulfoxides, ureas and their derivatives, ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons, and alcohols. Specifically, for example, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, cyclohexanone, diethyl oxalate, ethyl lactate, methyl lactate, butyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, benzyl alcohol, phenyl glycol, tetrahydrofurfuryl alcohol, diethylene glycol dimethyl ether, 1,4-dichlorobutane, o-dichlorobenzene, anisole, xylene, mesitylene, etc. can be used.

[0078] <Viscosity> The viscosity of the photosensitive resin composition according to this embodiment is 0.02 to 1.5 Pa·s when measured with an E-type viscometer at 23°C. If the viscosity of the photosensitive resin composition is 0.02 Pa·s or higher, a coating film of sufficient thickness can be obtained, and if it is 1.5 Pa·s or lower, a coating film with good in-plane uniformity can be obtained. The lower limit of the viscosity of the photosensitive resin composition is preferably 0.08 Pa·s or higher (i.e., 0.8 P or higher), more preferably 0.1 Pa·s or higher (i.e., 1 P or higher), and particularly preferably 0.12 Pa·s or higher (i.e., 1.2 P or higher), when measured with an E-type viscometer at a temperature of 23°C. The upper limit of the viscosity of the photosensitive resin composition, when measured using an E-type viscometer at a temperature of 23°C, is preferably 1.4 Pa·s or less (i.e., 14 P or less), more preferably 1.3 Pa·s or less (i.e., 13 P or less), even more preferably 1.2 Pa·s or less (i.e., 12 P or less), even more preferably 1.1 Pa·s or less (i.e., 11 P or less), even more preferably 1.0 Pa·s or less (i.e., 10 P or less), and most preferably 0.8 Pa·s or less (i.e., 8 P or less).

[0079] (D) Nitrogen-containing heterocyclic compound The photosensitive resin composition according to this embodiment may further contain (D) a nitrogen-containing heterocyclic compound. The inclusion of this compound results in good adhesion to copper.

[0080] The nitrogen-containing heterocyclic compound according to this embodiment is not limited to any heterocyclic compound containing a nitrogen atom, but from the viewpoint of improving copper adhesion, triazole compounds, tetrazole compounds, and purine compounds are preferred, and purine compounds are more preferred.

[0081] Specific examples of triazole compounds include, for example, 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-t-butyl-5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, phenyltriazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, hydroxyphenyltriazole, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 1H-benzotriazole, and 2-(5-methyl-2-hydroxyphenyl)benzotriazole. Examples include 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, and 5-carboxy-1H-benzotriazole.

[0082] Specific examples of tetrazole compounds include, for example, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, and 1-methyl-1H-tetrazole.

[0083] Specific examples of purine compounds include, for example, purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, 2,6-diaminopurine, 9-methyladenine, 2-hydroxyadenine, 2-methyladenine, 1-methyladenine, N-methyladenine, N,N-dimethyladenine, 2-fluoroadenine, 9-(2-hydroxyethyl)adenine, guanine oxime, N-(2-hydroxyethyl)adenine, 8-aminopurine. Examples include noadenine, 6-amino-8-phenyl-9H-purine, 1-ethyladenine, 6-ethylaminopurine, 1-benzyladenine, N-methylguanine, 7-(2-hydroxyethyl)guanine, N-(3-chlorophenyl)guanine, N-(3-ethylphenyl)guanine, 2-azaadenine, 5-azaadenine, 8-azaadenine, 8-azaguanine, 8-azapurine, 8-azaxanthine, and 8-azahypoxanthine, as well as derivatives thereof.

[0084] When the photosensitive resin composition of this embodiment contains (D) a nitrogen-containing heterocyclic compound, the content is preferably 0.01 to 20 parts by mass, more preferably 0.03 to 10 parts by mass, and even more preferably 0.05 to 5 parts by mass, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide, from the viewpoint of photosensitivity characteristics. For example, it may be 0.01 to 5 parts by mass. When the content of (D) a nitrogen-containing heterocyclic compound is 0.01 parts by mass or more, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide, when the photosensitive resin composition is formed on copper or a copper alloy, copper adhesion is further improved, while when it is 20 parts by mass or less, the resolution is further improved.

[0085] (E) Photopolymerizable unsaturated monomer The photosensitive resin composition of this embodiment may further contain (E) a photopolymerizable unsaturated monomer in order to improve the resolution of the relief pattern. In this disclosure, a photopolymerizable unsaturated monomer means a monomer having a photopolymerizable unsaturated bond, which undergoes a radical polymerization reaction with a photopolymerization initiator.

[0086] Preferred monomers include (meth)acrylic compounds, and are not limited to the following, but include, for example, monoacrylate, diacrylate, monomethacrylate, and dimethacrylate of ethylene glycol; monoacrylate, diacrylate, monomethacrylate, and dimethacrylate of polyethylene glycol; monoacrylate, diacrylate, monomethacrylate, and dimethacrylate of propylene glycol; monoacrylate, diacrylate, monomethacrylate, and dimethacrylate of polypropylene glycol; monoacrylate, diacrylate, monomethacrylate, and dimethacrylate of glycerol; diacrylate and dimethacrylate of cyclohexane; diacrylate and dimethacrylate of 1,4-butanediol. Examples of compounds include diacrylates and dimethacrylates of 1,6-hexanediol; diacrylates and dimethacrylates of neopentyl glycol; monoacrylates, diacrylates, monomethacrylates, and dimethacrylates of bisphenol A; benzene trimethacrylate; isobornyl acrylates and isoboronyl methacrylates; acrylamides and their derivatives; methacrylamides and their derivatives; trimethylolpropane triacrylates and trimethylolpropane trimethacrylates; diacrylates, triacrylates, tetraacrylates, dimethacrylates, trimethacrylates, and tetramethacrylates of pentaerythritol; and compounds such as ethylene oxide adducts or propylene oxide adducts of these compounds.

[0087] Examples of such monomers include isocyanurate compounds, with tris-(2-acryloxyethyl)isocyanurate being preferred.

[0088] If the photosensitive resin composition contains the above-mentioned (E) photopolymerizable unsaturated monomer for improving the resolution of the relief pattern, the content of the (E) photopolymerizable unsaturated monomer is preferably 1 to 50 parts by mass based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide.

[0089] <Other Components> The photosensitive resin composition of this embodiment contains (A-1) a polyimide precursor or (A-2) a soluble polyimide, (B) a photopolymerization initiator, and (C) an organic solvent as essential components, and may also contain one or more selected from the group consisting of (D) nitrogen-containing heterocyclic compounds and (E) photopolymerizable unsaturated monomers, but may also optionally contain other components. Examples of such components include hindered phenol compounds, organotitanium compounds, adhesion aids, sensitizers, and thermal polymerization inhibitors.

[0090] To suppress discoloration of the copper surface with respect to the hindered phenol compound, the photosensitive resin composition of this embodiment may optionally contain a hindered phenol compound.

[0091] Examples of hindered phenol compounds include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butyl-hydroquinone, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), trie Tylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2,2'-methylene-bis(4- Ethyl-6-t-butylphenol), pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-isopropylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4- t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-s-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,1,3,5-tris(4-t-butyl-3-hydroxy-2,5,6-trimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H) -Trion,1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-Trion,1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-Trion,1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2,6-dimethyl (Droxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,1,3,5-tris(4-t-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,1,3,5-tris(4-t-butyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1 Examples include, but are not limited to, H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, and 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.

[0092] Among these, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione is particularly preferred.

[0093] The content of the hindered phenol compound in the photosensitive resin composition of this embodiment is preferably 0.1 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of (A) polyimide precursor. When the content of the hindered phenol compound based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide is 0.1 parts by mass or more, for example, when the photosensitive resin composition of this disclosure is formed on copper or a copper alloy, discoloration and corrosion of the copper or copper alloy are prevented, while when it is 20 parts by mass or less, the photosensitivity is excellent.

[0094] The photosensitive resin composition of this embodiment may contain an organotitanium compound. By containing an organotitanium compound, the photosensitive resin composition of this embodiment can form a photosensitive resin layer with excellent chemical resistance even when cured at low temperatures.

[0095] Examples of organotitanium compounds usable in this embodiment include those in which an organic group is bonded to a titanium atom via a covalent or ionic bond.

[0096] Specific examples of organotitanium compounds are shown in I) to VII) below:

[0097] I) Titanium chelate compounds: Among these, titanium chelate compounds having two or more alkoxyl groups are more preferred because they provide good storage stability for photosensitive resin compositions, and especially when the photosensitive resin composition is negative type, they exhibit excellent storage stability and yield a good curing pattern. Specific examples include titanium bis(triethanolamine)diisopropoxide, titanium di(n-butoxide)bis(2,4-pentanedione), titanium diisopropoxidebis(2,4-pentanedione), titanium diisopropoxidebis(tetramethylheptanedione), and titanium diisopropoxidebis(ethylacetoacetate).

[0098] II) Tetraalkoxy titanium compounds: For example, titanium tetra(n-butoxide), titanium tetraethoxide, titanium tetra(2-ethylhexoxide), titanium tetraisobutoxide, titanium tetraisopropoxide, titanium tetramethoxide, titanium tetramethoxypropoxide, titanium tetramethylphenoxide, titanium tetra(n-nonyloxide), titanium tetra(n-propoxide), titanium tetrastearaloxide, and titanium tetrakis[bis{2,2-(alyloxymethyl)butoxide}].

[0099] III) Titanocene compounds: e.g., pentamethylcyclopentadienyltitanium trimethoxide, bis(η ５ -2,4-cyclopentadiene-1-yl)bis(2,6-difluorophenyl)titanium, and bis(η ５ Examples include (-2,4-cyclopentadiene-1-yl)bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium.

[0100] IV) Monoalkoxy titanium compounds: For example, titanium tris(dioctyl phosphate) isopropoxide and titanium tris(dodecylbenzenesulfonate) isopropoxide.

[0101] V) Titanium oxide compounds: For example, titanium oxide bis(pentanedione), titanium oxide bis(tetramethylheptanedione), and phthalocyanine titanium oxide.

[0102] VI) Titanium tetraacetylacetonate compounds: For example, titanium tetraacetylacetonate, etc.

[0103] VII) Titanate coupling agents: For example, isopropyltridodecylbenzenesulfonyl titanate.

[0104] Among these, the organotitanium compound is preferably at least one compound selected from the group consisting of I) titanium chelate compounds, II) tetraalkoxytitanium compounds, and III) titanocene compounds, from the viewpoint of achieving better chemical resistance. In particular, titanium diisopropoxide bis(ethyl acetate), titanium tetra(n-butoxide), and bis(η ５ (-2,4-cyclopentadiene-1-yl)bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium is preferred.

[0105] When an organic titanium compound is incorporated into the photosensitive resin composition of this embodiment, its content is preferably 0.05 to 10 parts by mass, and more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide. When the content is 0.05 parts by mass or more, the resulting cured pattern exhibits good heat resistance and chemical resistance, while when it is 10 parts by mass or less, the photosensitive resin composition exhibits excellent storage stability.

[0106] Adhesion Aids: To improve the adhesion between the film formed using the photosensitive resin composition of this embodiment and the substrate, the photosensitive resin composition of this embodiment may optionally contain an adhesion aid, and it is particularly preferable to include an adhesion aid when the photosensitive resin composition is of the negative type. As the adhesion aid, aluminum-based adhesion aids and silane coupling agents can be used.

[0107] Examples of aluminum-based adhesives include aluminum tris(ethyl acetate), aluminum tris(acetylacetonate), and ethyl acetate aluminum diisopropylate.

[0108] Examples of silane coupling agents include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, trimethoxyphenylsilane, trimethoxy(p-tolyl)silane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, and N-(3-diethoxymethylsilyl Propyl) succinimide, N-[3-(triethoxysilyl)propyl]phthalamidic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, N-phenylaminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-(trialkoxysilyl)propyl succinic anhydride,

[0109] 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: product name KBM803, manufactured by Chisso Corporation: product name Cyra Ace S810), 3-mercaptopropyltriethoxysilane (manufactured by Azmax Co., Ltd.: product name SIM6475.0), 3-mercaptopropylmethyldimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.: product name LS1375, manufactured by Azmax Co., Ltd.: product name SIM6474.0), mercaptomethyltrimethoxysilane (manufactured by Azmax Co., Ltd.: product name SIM6473.5C), mercaptomethylmethyldimethoxysilane (manufactured by Azmax Co., Ltd.: product name SIM6473.0), 3-mercaptopropyldiethoxymethoxysilane, 3-mercaptopropylethoxydimethoxysilane, 3-mercaptopropyltripropoxysilane, 3-mercaptopropyldiethoxypropoxysilane, 3-mercaptopropylethoxydipropoxysilane, 3-mercaptopropyldimethoxypropoxysilane, 3-mercaptopropylmethoxydipropoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyl Diethoxymethoxysilane, 2-mercaptoethylethoxydimethoxysilane, 2-mercaptoethyltripropoxysilane, 2-mercaptoethyltripropoxysilane, 2-mercaptoethylethoxydipropoxysilane, 2-mercaptoethyldimethoxypropoxysilane, 2-mercaptoethylmethoxydipropoxysilane, 4-mercaptobutyltrimethoxysilane, 4-mercaptobutyltriethoxysilane, 4-mercaptobutyltripropoxysilane,

[0110] N-(3-triethoxysilylpropyl)urea (manufactured by Shin-Etsu Chemical Co., Ltd.: product name LS3610, manufactured by Azmax Co., Ltd.: product name SIU9055.0), N-(3-trimethoxysilylpropyl)urea (manufactured by Azmax Co., Ltd.: product name SIU9058.0), N-(3-diethoxymethoxysilylpropyl)urea, N-(3-ethoxydimethoxysilylpropyl)urea, N-(3-tripropoxysilylpropyl)urea, N-(3-diethoxypropoxysilylpropyl)urea, N-(3-ethoxydipropoxysilylpropyl)urea, N-(3-dimethoxypropoxysilylpropyl)urea, N-(3-methoxydipropoxysilylpropyl)urea, N-(3-trimethoxysilylethyl)urea , N-(3-ethoxydimethoxysilylethyl)urea, N-(3-tripropoxysilylethyl)urea, N-(3-tripropoxysilylethyl)urea, N-(3-ethoxydipropoxysilylethyl)urea, N-(3-dimethoxypropoxysilylethyl)urea, N-(3-methoxydipropoxysilylethyl)urea, N-(3-trimethoxysilylbutyl)urea, N-(3-triethoxysilylbutyl)urea, N-(3-tripropoxysilylbutyl)urea,

[0111] 3-(m-aminophenoxy)propyltrimethoxysilane (manufactured by Azmax Co., Ltd.: product name SLA0598.0), m-aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: product name SLA0599.0), p-aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: product name SLA0599.1)aminophenyltrimethoxysilane (manufactured by Azmax Co., Ltd.: product name SLA0599.2), 2-(trimethoxysilylethyl)pyridine (manufactured by Azmax Co., Ltd.: product name SIT8396.0), 2-(triethoxysilylethyl)pyridine, 2-(dimethoxysilylmethylethyl)pyridine, 2-(diethoxysilylmethylethyl)pyridine, (3-triethoxysilylpropyl)-t-butylcarbamate, (3-glycidoxypropyl)triethoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane, tetra-t-butoxysilane, tetrakis(methoxyethoxysilane), tetrakis(methoxy-n-propoxysilane) , tetrakis(ethoxyethoxysilane), tetrakis(methoxyethoxyethoxysilane), bis(trimethoxysilyl)ethane, bis(trimethoxysilyl)hexane, bis(triethoxysilyl)methane, bis(triethoxysilyl)ethane, bis(triethoxysilyl)ethylene, bis(triethoxysilyl)octane, bis(triethoxysilyl)octadiene, bis[3-(triethoxysilyl)propyl]disulfide, bis[3-(triethoxysilyl)propyl]tetrasulfide, di-t-butoxydiacetoxysilane, di-i-butoxyaluminoxytriethoxysilane,

[0112] Phenylsilanetriol, methylphenylsilanediol, ethylphenylsilanediol, n-propylphenylsilanediol, isopropylphenylsilanediol, n-butylsiphenylsilanediol, isobutylphenylsilanediol, tert-butylphenylsilanediol, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, ethylmethylphenylsilanol, n-propylmethylphenylsilanol, isopropylmethylphenylsilanol, n-butylmethylphenylsilanol, isobutyl Methylphenylsilanol, tert-butylmethylphenylsilanol, ethyl n-propylphenylsilanol, ethylisopropylphenylsilanol, n-butylethylphenylsilanol, isobutylethylphenylsilanol, tert-butylethylphenylsilanol, methyldiphenylsilanol, ethyldiphenylsilanol, n-propyldiphenylsilanol, isopropyldiphenylsilanol, n-butyldiphenylsilanol, isobutyldiphenylsilanol, tert-butyldiphenylsilanol, triphenylsilanol, etc., and the following formula (S-1): Examples of silane coupling agents include, but are not limited to, those represented by the respective terms.

[0113] Among these adhesive aids, it is more preferable to use a silane coupling agent from the viewpoint of adhesive strength. As a silane coupling agent, from the viewpoint of storage stability, it is preferable to use one or more selected from the group consisting of phenylsilanetriol, trimethoxyphenylsilane, trimethoxy(p-tolyl)silane, diphenylsilanediol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol, and the silane coupling agent represented by the above formula (S-1).

[0114] When the photosensitive resin composition of this embodiment contains an adhesive aid, the content of the adhesive aid is preferably in the range of 0.01 to 25 parts by mass, and more preferably in the range of 0.5 to 20 parts by mass, based on 100 parts by mass of (A) polyimide precursor. When a silane coupling agent is used as the adhesive aid, the content is preferably 0.01 to 20 parts by mass, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide.

[0115] Sensitizer The photosensitive resin composition of this embodiment may optionally contain a sensitizer to improve photosensitivity. Examples of the sensitizer include Michla's ketone, 4,4'-bis(diethylamino)benzophenone, 2,5-bis(4'-diethylaminobenzal)cyclopentane, 2,6-bis(4'-diethylaminobenzal)cyclohexanone, 2,6-bis(4'-diethylaminobenzal)-4-methylcyclohexanone, 4,4'-bis(dimethylamino)chalcone, 4,4'-bis(diethylamino)chalcone, and p-dimethylaminocinnamyridane indano n, p-dimethylaminobenzylideneindanone, 2-(p-dimethylaminophenylbiphenylene)-benzothiazole, 2-(p-dimethylaminophenylvinylene)benzothiazole, 2-(p-dimethylaminophenylvinylene)isonaphthiazole, 1,3-bis(4'-dimethylaminobenzal)acetone, 1,3-bis(4'-diethylaminobenzal)acetone, 3,3'-carbonyl-bis(7-diethylaminocoumarin), 3-aceti Examples include 7-dimethylaminocoumarin, 3-ethoxycarbonyl-7-dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, 3-ethoxycarbonyl-7-diethylaminocoumarin, N-phenyl-N'-ethylethanolamine, N-phenyldiethanolamine, N-p-tolyldiethanolamine, N-phenylethanolamine, 4-morpholinobenzophenone, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 2-mercaptobenzimidazole, 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, and 2-(p-dimethylaminobenzoyl)styrene. These can be used individually or in combinations of two to five types.

[0116] If the photosensitive resin composition of this embodiment contains a sensitizer for improving light sensitivity, the amount thereof is preferably 0.1 to 25 parts by mass, based on 100 parts by mass of (A-1) polyimide precursor or (A-2) soluble polyimide.

[0117] Thermal polymerization inhibitor The photosensitive resin composition of this embodiment may optionally contain a thermal polymerization inhibitor to improve the stability of viscosity and photosensitivity, especially when stored in a solvent-containing solution. Examples of thermal polymerization inhibitors that can be used include hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol etherdiaminetetraacetic acid, 2,6-di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt.

[0118] <Method for manufacturing a cured relief pattern> The method for manufacturing a cured relief pattern according to the present disclosure includes: (1) a step of applying the above-described photosensitive resin composition of the present disclosure to a substrate to form a photosensitive resin layer on the substrate (resin layer formation step); (2) a step of exposing the above-described photosensitive resin layer to light (exposure step); (3) a step of developing the photosensitive resin layer after exposure to form a relief pattern (relief pattern formation step); and (4) a step of heat-treating the above-described relief pattern to form a cured relief pattern (cured relief pattern formation step).

[0119] (1) Resin layer formation process In this process, the photosensitive resin composition of this embodiment is applied to the surface of the substrate, and if necessary, it is then dried to form a photosensitive resin layer. As for the application method, methods used in panel-level processes, such as application using a bar coater, blade coater, curtain coater, slit coater, screen printing machine, etc., and spray application using a spray coater can be used.

[0120] If necessary, the coating film containing the photosensitive resin composition of this embodiment can be dried. Drying methods include air drying, heating with an oven or hot plate, and vacuum drying. Specifically, in the case of air drying or heating, drying can be performed at a temperature of 20°C to 150°C for 1 minute to 1 hour. In this way, a photosensitive resin layer can be formed on the surface of the substrate. In the case of vacuum drying, the achievable vacuum level is not a problem as long as drying is completed, but it can be 100 Pa or less, 80 Pa or less, or 60 Pa or less.

[0121] (2) Exposure process In this process, the photosensitive resin layer formed above is exposed to ultraviolet light or the like using an exposure device such as a contact aligner, mirror projection, or stepper, either through a photomask or reticle having a pattern, or directly. This exposure causes the polymerizable groups of the soluble polyimide contained in the photosensitive resin composition and / or the polymerizable groups of (E) photopolymerizable unsaturated monomers to crosslink due to the action of (B) photopolymerization initiator. This crosslinking makes the exposed area insoluble in the developer solution described later, thus enabling the formation of a relief pattern.

[0122] Subsequently, if necessary, post-exposure baking (PEB), pre-development baking, or both may be performed using any combination of temperature and time, for purposes such as improving photosensitivity. The baking conditions are preferably a temperature of 40°C to 120°C and a time of 10 seconds to 240 seconds, but are not limited to this range as long as they do not impair the properties of the photosensitive resin composition.

[0123] (3) Relief pattern formation process In this process, the unexposed portion of the photosensitive resin layer after exposure is developed and removed. As a development method for developing the photosensitive resin layer after exposure (irradiation), any method can be selected and used from conventionally known photoresist development methods, such as the rotary spray method, the paddle method, and the immersion method with ultrasonic treatment. After development, if necessary, a post-development bake may be performed using any combination of temperature and time for purposes such as adjusting the shape of the relief pattern.

[0124] The developer used for development is preferably, for example, a good solvent for the photosensitive resin composition, or a combination of the good solvent and a poor solvent. Preferred good solvents include, for example, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, and α-acetyl-γ-butyrolactone. Preferred poor solvents include, for example, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate, and water. When using a mixture of the good solvent and the poor solvent, it is preferable to adjust the ratio of the poor solvent to the good solvent according to the solubility of the polymer in the photosensitive resin composition. Two or more good solvents and poor solvents can also be used in combination, for example, several types.

[0125] (4) Cured Relief Pattern Formation Process In this process, the relief pattern obtained by the above development is heat-treated to dilute the photosensitive component and convert it into a cured relief pattern. Various methods can be selected for the heat treatment, such as using a hot plate, using an oven, or using a heating oven with a temperature program that can be set. The heat treatment can be carried out, for example, at a temperature of 150°C to 350°C for 30 minutes to 5 hours. The temperature for the heat treatment is preferably 150°C to 250°C, more preferably 150°C to 230°C, and even more preferably 170°C to 230°C. Air may be used as the atmospheric gas during heat curing, and inert gases such as nitrogen and argon may also be used.

[0126] <Method for producing polyimide, Method for producing polyimide-containing cured product> In another aspect of the present disclosure, a method for producing polyimide is provided, comprising the step of curing the photosensitive resin composition described above to form a polyimide. In yet another aspect, a method for producing a polyimide-containing cured product or a polyimide-containing cured film is provided, comprising the step of curing the photosensitive resin composition described above to form a polyimide-containing cured product or a polyimide-containing cured film. The curing conditions for the photosensitive resin composition may be, for example, the same as the baking conditions included in the method for producing a cured relief pattern described above, or the conditions for the cured relief pattern formation step (4).

[0127] <Semiconductor Device> This disclosure also provides a semiconductor device having a cured relief pattern obtained from the photosensitive resin composition described above. More specifically, a semiconductor device is provided having a substrate which is a semiconductor element and a cured relief pattern. The cured relief pattern may be manufactured using the photosensitive resin composition described above by the method for manufacturing the cured relief pattern described above.

[0128] This disclosure can also be applied to a method for manufacturing a semiconductor device, which uses a semiconductor element as a substrate and includes the method for manufacturing the cured relief pattern described above as part of the process. In this case, the cured relief pattern formed by the method for manufacturing the cured relief pattern of this disclosure can be formed as a surface protective film for a semiconductor device, an interlayer insulating film, an insulating film for redistribution, a protective film for a flip-chip device, or a protective film for a semiconductor device having a bump structure, and can be manufactured by combining it with a known method for manufacturing a semiconductor device.

[0129] <Display Device> This disclosure provides a display device comprising a display element and a cured film provided on the upper part of the display element, wherein the cured film is the cured relief pattern described above. Here, the cured relief pattern may be laminated in direct contact with the display element, or it may be laminated with another layer in between. The cured film can be applied, for example, to surface protective films, insulating films, planarization films, etc. of TFT liquid crystal display elements and color filter elements; protrusions for MVA type liquid crystal display devices; partitions for the cathode of organic EL elements; etc.

[0130] In addition to applications in semiconductor devices as described above, the photosensitive resin composition of this disclosure is also useful for applications such as interlayer insulation of multilayer circuits, cover coatings for flexible copper-clad sheets, solder resist films, and liquid crystal alignment films.

[0131] <Measurement and Evaluation Method> (1) Weight-average molecular weight The weight-average molecular weight (Mw) of each resin was measured using gel permeation chromatography (standard polystyrene equivalent) under the following conditions. Pump: JASCO PU-980 Detector: JASCO RI-930 Column oven: JASCO CO-965 40℃ Column: Showa Denko K.K. Shodex KD-805 / KD-804 / KD-803 in series Standard monodisperse polystyrene: Showa Denko K.K. Shodex STANDARD SM-105 Mobile phase: 0.1 mol / L LiBr / N-methyl-2-pyrrolidone (NMP) Flow rate: 1 mL / min.

[0132] (2) Viscosity measurement The viscosity was measured at 23°C using an E-type viscometer (RE-80R, manufactured by Toki Sangyo Co., Ltd.).

[0133] (3) Slit Coat Test The photosensitive resin compositions prepared in the examples and comparative examples were applied to a 300 mm x 300 mm glass substrate with a coating area of ​​295 mm x 295 mm using a slit coater (manufactured by SCREEN Finetech Solutions Co., Ltd.), and the coating was evaluated. The photosensitive resin compositions prepared in the examples and comparative examples were filled into the nozzle of the slit coater and evaluated according to the following criteria. After starting and stopping the discharge of the photosensitive resin composition from the nozzle, the photosensitive resin composition dripped from the slit nozzle: leakage The photosensitive resin composition was not discharged from the nozzle: clogging Coating was possible without leakage or clogging: no problem

[0134] (4) Evaluation of film thickness uniformity Using the slit coater used in the slit coat test in (3) above, slit coating was performed with a slit gap of 150 μm, a discharge rate of 50 μL / sec, and a coating rate of 10 mm / sec. The slit coat substrate was dried in a vacuum drying apparatus at room temperature for 5 minutes at a maximum vacuum of 13 Pa, and then further dried at 110°C for 5 minutes under normal pressure to remove the solvent. Film thickness was measured at 30 points at 20 mm intervals using a contact step meter (Bruker, Dektak 8). The film thickness uniformity of the coated film (standard deviation of the film thickness at 30 points) was calculated and evaluated according to the following criteria: Excellent: In-plane film thickness uniformity (3 sigma) of 0.5 μm or less. Good: In-plane film thickness uniformity (3 sigma) greater than 0.5 μm and 1.5 μm or less. Acceptable: In-plane film thickness uniformity (3 sigma) greater than 1.5 μm and 2.0 μm or less. Unacceptable: In-plane film thickness uniformity (3 sigma) is greater than 2.0 μm.

[0135] (5) Reflow Test The coating film obtained in (4) above was heated and cured for 2 hours at 230°C in a nitrogen atmosphere using a high-temperature clean oven (CLH-21CD-S, manufactured by Koyo Thermo Systems Co., Ltd.). The resulting cured film was cut into 100 mm x 100 mm pieces and heated to a peak temperature of 260°C in a nitrogen atmosphere under simulated solder reflow conditions using a mesh belt type continuous firing furnace (model 6841-20AMC-36, manufactured by Koyo Thermo Systems Co., Ltd.). The simulated reflow conditions were standardized by assuming a high solder melting point of 220°C, in accordance with the solder reflow conditions described in section 7.6 of IPC / JEDEC J-STD-020A, a standard of the US semiconductor industry association for evaluation methods of semiconductor devices. The cured film after reflow was observed and evaluated according to the following criteria. Excellent: None of the nine samples showed any cracks or peeling from the substrate in the cured film. Good: One or two cracks or peeling of the cured film from the substrate were observed. Acceptable: Three to five cracks or peeling of the cured film from the substrate were observed. Unacceptable: Six to nine cracks or peeling of the cured film from the substrate were observed.

[0136] <Preparation Example 1> 155 g (0.5 mol) of 4,4'-oxydiphthalic acid dianhydride (ODPA) was placed in a 2-liter separable flask, 135 g (1.04 mol) of 2-hydroxyethyl methacrylate (HEMA) and 400 ml of γ-butyrolactone were added, and the mixture was stirred at room temperature. 79.1 g of pyridine was added while stirring, and the mixture was stirred for 16 hours.

[0137] Next, under ice cooling, a solution of 203 g of dicyclohexylcarbodiimide (DCC) dissolved in 200 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, 89 g (0.44 mol) of 4,4'-diaminodiphenyl ether (4,4'-DADPE) suspended in 280 ml of γ-butyrolactone was added over 60 minutes with stirring. After further stirring at room temperature for 4 hours, 40 ml of ethyl alcohol was added and stirred for 1 hour, and then 1 liter of γ-butyrolactone was added. The precipitate formed in the reaction mixture was removed by filtration to obtain the reaction solution.

[0138] The resulting reaction solution was added to 4 liters of ethyl alcohol to produce a precipitate consisting of crude polymer. The crude polymer was filtered off and dissolved in 2.5 liters of tetrahydrofuran to obtain a crude polymer solution. The obtained crude polymer solution was added dropwise to 30 liters of water to precipitate the polymer, and the resulting precipitate was filtered off and then vacuum dried to obtain a powdered polymer (polymer A-1). The molecular weight of polymer A-1 was measured by gel permeation chromatography (on a standard polystyrene basis), and the weight-average molecular weight (Mw) was found to be 24,000.

[0139] <Production Example 2> The reaction was carried out in the same manner as in Production Example 1, except that 94 g (0.44 mol) of 2,2'-dimethyl-4,4-diaminobiphenyl (m-TB) was used instead of 89 g of 4,4'-DADPE to obtain polymer A-2. The molecular weight of polymer A-2 was measured by gel permeation chromatography (on a standard polystyrene basis), and the weight-average molecular weight (Mw) was 21,000.

[0140] <Production Example 3> The reaction was carried out in the same manner as in Production Example 2, except that 46 g (0.44 mol) of p-phenylenediamine (pPD) was used instead of 89 g of 4,4'-DADPE to obtain polymer A-3. The molecular weight of polymer A-3 was measured by gel permeation chromatography (on a standard polystyrene basis), and the weight-average molecular weight (Mw) was 19,000.

[0141] <Production Example 4> Polymer A-4 was obtained by carrying out the reaction in the same manner as in Production Example 1, except that 62 g (0.2 mol) of ODPA and 65 g (0.3 mol) of pyromellitic dianhydride (PMDA) were used instead of 155 g of ODPA, and 94 g (0.44 mol) of 2,2'-dimethyl-4,4-diaminobiphenyl (m-TB) was used instead of 89 g of 4,4'-DADPE. The molecular weight of polymer A-4 was measured by gel permeation chromatography (on a standard polystyrene basis), and the weight-average molecular weight (Mw) was 20,000.

[0142] <Production Example 5> In a flask equipped with a stirrer and condenser, 20.8 g (40.0 mmol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride was dissolved in 100 g of N-methylpyrrolidone at a temperature between 20°C and 30°C. Subsequently, 15.3 g (37.2 mmol) of 4,4'-isopropylidenebis[(4-aminophenoxy)benzene] was added and the mixture was stirred for 1 hour. Then, while flowing nitrogen, the temperature was raised to 190°C, stirred for 5 hours, and cooled to below 30°C. Subsequently, the mixture was diluted with 50 g of tetrahydrofuran, precipitated in 2 L of methanol, filtered, and recovered. The mixture was then vacuum-dried at 45°C for 1 day to obtain polyimide resin (A-5). The weight-average molecular weight of the obtained polyimide (A-5) was 18,000.

[0143] <Production Example 6> 20.80 g (40 mmol) of 4,4'-(4,4'-isopropylidene diphenoxy)diphthalic anhydride was dissolved in 70 g of N-methylpyrrolidone (NMP). Subsequently, 9.08 g (35.2 mmol) of 4,4'-isopropylidene bis(2-aminophenol) was dissolved in 50 g of NMP and added dropwise over 1 hour at a temperature of 10°C to 25°C. After stirring at 25°C for 30 minutes, 10 g of toluene was added, and the reaction was carried out at 200°C for 4 hours with nitrogen flow, and then cooled to 25°C. Next, 15.3 g (100 mmol) of 4-(chloromethyl)styrene, 16.6 g (120 mmol) of potassium carbonate, 1.66 g (12 mmol) of potassium iodide, and 0.08 g of 2,2,6,6-tetramethylpiperidine 1-oxyl free radical were added, and the mixture was reacted at 95°C for 15 hours. After cooling to 25°C, the mixture was diluted with 120 g of tetrahydrofuran. Subsequently, the reaction mixture was added dropwise to a mixture of 1.8 liters of methanol and 0.6 L of water, stirred for 15 minutes, and then the polyimide resin was filtered. Next, the resin was re-slurred with 1 L of water, filtered, re-slurred again with 1 L of methanol, filtered, and dried under reduced pressure at 40°C for 8 hours. Next, the dried resin was dissolved in 250 g of tetrahydrofuran, and 40 g of ion exchange resin (MB-1: manufactured by Organo) was added. The mixture was stirred for 4 hours, and after filtering out the ion exchange resin, the polyimide resin was precipitated in 2 liters of methanol and stirred for 15 minutes. The polyimide resin was filtered to obtain polyimide (A-6), which was dried under reduced pressure at 45°C for 1 day. The weight-average molecular weight of the obtained polyimide (A-6) was 16,000.

[0144] <Production Example 7> The polymerization reaction was carried out in a 1-liter three-necked jacketed round-bottom flask equipped with a mechanical stirrer, thermocouple, and nitrogen inlet to maintain positive nitrogen pressure throughout the reaction. 39.95 g of 4,4'-[1,4-phenylene-bis(1-methylethylidene)]bisaniline (DAPI) and 600 g of anhydrous N-methyl-2-pyrrolidone were added to the flask. The contents were stirred at 18-20°C until a homogeneous solution was obtained. Next, 51.75 g of 1-(3',4'-dicarboxyphenyl)-1,3,3-trimethylindan-5,6-dicarboxylic acid dianhydride (DAPI dianhydride) was added to the stirred diamine solution via a funnel. The funnel was rinsed into the reaction flask with 66.0 g of anhydrous N-methylpyrrolidone. The mixture was heated to 60°C and stirred for 3 hours.

[0145] To perform the end-blocking reaction, 4.2 g of exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride (oxonadic anhydride) and 2.0 g of pyridine were placed in a flask. This mixture was stirred at 60°C for 3 hours.

[0146] To carry out the imidation reaction, 10.2 g of acetic anhydride and 2.0 g of pyridine were added to a reaction vessel. This reaction mixture was heated to 100°C and stirred for 12 hours. A small sample (1 g) was taken out and precipitated in methanol:water (10 ml) in a mass ratio of 50:50. The solid was isolated by filtration and dried. Fourier transform infrared spectroscopy showed that the imidation reaction was completed.

[0147] The obtained solution was cooled to room temperature and added dropwise to 4 liters of vigorously stirred deionized water to precipitate the polymer. The polymer was collected by filtration and washed with 1 liter of deionized water. The filtration cake was re-slurried with 1 liter of methanol and filtered. The wet filtration cake was dried in air for 12 hours, and then the polymer was dried under vacuum at 70°C for 12 hours to obtain polyimide A-7. The weight-average molecular weight of the obtained polyimide (A-7) was 16,000.

[0148] <Example 1> A negative-type photosensitive resin composition was prepared by the following method, and the prepared composition was evaluated. (A-1) Polymer A-1: ​​100 g as a polyimide precursor, (B) 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)-oxime (B-1): 4 g as a photopolymerization initiator, N-phenyldiethanolamine: 8 g as a sensitizer, (C) N-ethyl-2-pyrrolidone (C-1): 420 g as a solvent, (D) benzotriazole (D-1): 0.4 g as a nitrogen-containing heterocyclic compound, and (E) polyethylene glycol dimethacrylate (E-1): 8 g as a photopolymerizable unsaturated monomer were added and dissolved to prepare a photosensitive resin composition. The composition was evaluated according to the method described above. The results are shown in Table 1. Furthermore, a fan-out type panel-level chip-size package semiconductor device was fabricated and operated without problems.

[0149] <Examples 2-18> Photosensitive resin compositions were prepared and evaluated in the same manner as in Example 1, except that the compositions were as shown in Table 1.

[0150] <Comparative Examples 1 and 2> Photosensitive resin compositions were prepared and evaluated in the same manner as in Example 1, except for the composition shown in Table 1. The photosensitive resin compositions of Comparative Examples 1 and 2 exhibited leakage and clogging, making it impossible to fabricate fan-out type panel-level chip-size package semiconductor devices.

[0151] <Comparative Example 3> A photosensitive resin composition was prepared and evaluated in the same manner as in Example 1, except that the composition was as shown in Table 1. When a fan-out type panel-level chip-size package semiconductor device was fabricated, it did not function.

[0152]

[0153]

[0154]

[0155]

[0156] Explanation of the components in Table 1 (In Table 1, the values ​​for each component represent grams (g).) (A-1) Polyimide precursors A-1 to A-4 synthesized in the above production example (A-2) Soluble polyimides A-5 to A-7 synthesized in the above production example

[0157] (B) Photopolymerization initiators B-1: 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)-oxime B-2: 1,2-propanedione-3-cyclopentyl-1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime)

[0158] (C) Organic solvents C-1: N-ethyl-2-pyrrolidone (boiling point: 218°C) C-2: 1,3-dimethyl-2-imidazolidinone (boiling point: 220°C) C-3: 3-methoxy-N,N-dimethylpropanamide (boiling point: 215°C) C-4: 3-butoxy-N,N-dimethylpropanamide (boiling point: 252°C) C-5: N-methyl-2-pyrrolidone (boiling point: 202°C) C-6: Ethyl lactate (boiling point: 154°C)

[0159] (D) Nitrogen-containing heterocyclic compounds D-1: Benzotriazole

[0160] (E) Photopolymerizable unsaturated monomers E-1: Polyethylene glycol dimethacrylate E-2: Tris-(2-acryloxyethyl) isocyanurate

[0161] Sensitizer: N-phenyldiethanolamine

Claims

1. A photosensitive resin composition for use in a panel-level packaging process, comprising: (A) at least one selected from the group consisting of (A-1) polyimide precursors and (A-2) polyimide; (B) a photopolymerization initiator; and (C) an organic solvent, wherein the (C) organic solvent comprises at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide, and the viscosity measured with an E-type viscometer at 23°C is 0.02 to 1.5 Pa·s.

2. The photosensitive resin composition according to claim 1, wherein the (C) organic solvent does not contain a solvent having a boiling point of 160°C or lower, or contains less than 10% by mass of such a solvent, based on the total mass of the (C) organic solvent.

3. The photosensitive resin composition according to claim 1, wherein the (C) organic solvent contains, based on the total mass of the (C) organic solvent, more than 90% by mass of at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide.

4. The photosensitive resin composition according to claim 1, wherein the (C) organic solvent is at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and 3-methoxy-N,N-dimethylpropanamide.

5. The (A-1) polyimide precursor is the following general formula (1): {In formula (1), X １ Y is a tetravalent organic group having 4 to 40 carbon atoms. １ It is a divalent organic group having 6 to 40 carbon atoms, n １ is an integer between 2 and 150, and R １ and R ２ The photosensitive resin composition according to claim 1, wherein each of the elements represents independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms.

6. The aforementioned R １ , and the R ２ The photosensitive resin composition according to claim 5, wherein at least one of the members is a monovalent organic group having 1 to 40 carbon atoms.

7. The aforementioned X １ However, the following general formulas (2) to (4): The photosensitive resin composition according to claim 5, wherein at least one selected from the group consisting of the following.

8. The above Y １ is at least one selected from the group consisting of the following general formulas (5) to (7): The photosensitive resin composition according to claim 6, which is at least one selected from the group consisting of 9. The aforementioned X １ The following is the general formula (2): and the Y １ The following is the general formula (6): The photosensitive resin composition according to claim 6.

10. The aforementioned X １ The following is the general formula (3): and the Y １ The general formula is as follows (5): The photosensitive resin composition according to claim 6.

11. The aforementioned X １ The following is the general formula (3): And Y １ The general formula is as follows (7): The photosensitive resin composition according to claim 6.

12. The photosensitive resin composition according to claim 1, wherein the (A-2) polyimide does not contain fluorine atoms.

13. (D) The photosensitive resin composition according to claim 1, further comprising a nitrogen-containing heterocyclic compound.

14. (E) The photosensitive resin composition according to claim 1, further comprising a photopolymerizable unsaturated monomer.

15. The photosensitive resin composition according to claim 1, wherein the (B) photopolymerization initiator is an oxime compound.

16. A method for producing a polyimide, comprising the step of curing a photosensitive resin composition according to any one of claims 1 to 15 to form a polyimide.

17. A photosensitive resin composition according to any one of claims 1 to 15, used for developing with a developer in which 90% or more by mass of the developer is an organic solvent.

18. A method for producing a cured relief pattern, comprising the following steps: (1) applying a photosensitive resin composition according to any one of claims 1 to 15 to a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer to light; (3) developing the photosensitive resin layer after exposure to form a relief pattern; and (4) heat-treating the relief pattern to form a cured relief pattern.

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