Photosensitive polyimide resin composition

Abstract

The object of the present invention is to provide a photosensitive polyimide resin composition which is soluble in a developer during development and insoluble in a developer after photocrosslinking, and which can achieve good film properties and high sensitivity. The present invention provides a photosensitive polyimide resin composition, which contains (A) a solvent-soluble polyimide and (B) a diazide compound as essential components, wherein the (A) solvent-soluble polyimide is a block copolymer having in the main chain (a) an aromatic tetracarboxylic dianhydride residue having a benzophenone structure and (b) a residue of at least one diamine selected from an aromatic diamine having an alkyl group at an ortho position to an amino group, an aromatic diamine having an indane structure, and a diamine having a polysiloxane structure, and the content of the (B) diazide compound is 2.0 to 150 parts by weight relative to 100 parts by weight of the (A) solvent-soluble polyimide.

Description

Technical Field

[0001] The present invention relates to a photosensitive polyimide resin composition. Background Art

[0002] In recent years, in semiconductor package substrates, the transition from FC-CSP or FC-BGA to fan-out wafer level packaging (FO-WLP) that can reduce height, improve electrical characteristics (R, L, C), and reduce warpage has been actively studied, and some FO-WLPs have been mass-produced. Among the organic materials used in this FO-WLP, the key materials are sealing materials and various protective film materials, and photosensitive polyimide is used as the protective film material.

[0003] It is known that there are several ways to impart photosensitivity to photosensitive polyimide (Patent Document 1), and it is roughly divided into positive type and negative type according to the image forming process. The positive type has higher sensitivity than the negative type, but since it uses a photodecomposition reaction, it is difficult to expect to improve the physical properties through photoreaction. On the other hand, in the negative type, since the exposed part undergoes a photocrosslinking reaction and remains after the development process, it has the characteristics of easily improving chemical resistance and heat resistance. Therefore, the negative type has some problems in sensitivity when used as a permanent insulating film, but it can provide a film with excellent reliability.

[0004] Negative photosensitive polyimide can be roughly divided into a method of introducing a photosensitive group into a precursor such as polyamic acid and performing imidization by heating after a photoreaction and a method of making the closed-ring polyimide itself photosensitive. Representative methods in practical use in this field are a method of ester bonding with a hydroxy acrylate of polyamic acid (Patent Document 2) or a method of mixing an amino acrylate or the like into polyamic acid and introducing a photosensitive group through a salt bond (Patent Document 3).

[0005] In addition, as a method for making the closed-ring polyimide itself photosensitize, there have been reported a method of using a polyimide copolymer obtained by a condensation reaction of a tetracarboxylic dianhydride having a benzophenone structure and a diamine (Patent Document 4) or a method of adding an acryloyl group to the side chain of a solvent-soluble polyimide block copolymer synthesized by a two-step condensation reaction (Patent Document 5).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Kenichi Fukuda, Mitsuru Ueda, Collected Papers on Polymers, Vol. 63, No. 9, pp. 561-576,

[0009] Patent Document 2: Japanese Patent Publication No. 55-41422,

[0010] Patent Document 3: Japanese Patent Application Publication No. 54-145794,

[0011] Patent Document 4: Japanese Patent Application Laid-Open No. 5-39281,

[0012] Patent document 5: Japanese Patent Application Publication No. 2000-147768. Summary of the invention

[0013] Problems to be solved by the invention

[0014] The requirements for semiconductor package substrates are becoming more stringent year by year, and FO-WLP is no exception, requiring thinner patterns, smaller diameters of connecting vias, and multilayering. In order to meet these requirements, photosensitive polyimide is required to reduce warpage or improve dimensional stability under large panel sizes, in addition to improving sensitivity and film reliability, which is closely related to the biggest issue of FO-WLP, namely cost reduction.

[0015] However, in the currently practical method of using polyamic acid to heat imidization after photoreaction, high temperature (e.g., 350-450°C) is required for imidization, which causes syneresis or detachment or volatilization of photosensitive groups, resulting in large film shrinkage. This has a great impact on warpage or dimensional stability in the production process of semiconductor packages or electronic components, and becomes the main reason for the reduction of storage stability.

[0016] Even when a closed-ring polyimide is used, there is a problem that the polyimide needs to be soluble in a developer during development and the photosensitive portion becomes insoluble in a developer after exposure. Conventionally reported methods have a problem of insufficient exposure and development properties.

[0017] As a protective film material for such semiconductor package substrates, a photosensitive polyimide which is soluble in a developer during development and insoluble in a developer after photocrosslinking and which can achieve good film properties and improved sensitivity is required.

[0018] An object of the present invention is to provide a photosensitive polyimide resin composition which is soluble in a developer during development and insoluble in a developer after photocrosslinking and which can achieve good film properties and high sensitivity.

[0019] Means of solving problems

[0020] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that, by using a block copolymer having an aromatic acid dianhydride having a benzophenone structure and a specific diamine structure in the main chain as a closed-ring polyimide, and further combining the polyimide with a specific amount of a diazide compound, a photosensitive polyimide resin composition can be provided that has solvent solubility during development and solvent insolubility after photocrosslinking, and can achieve good film properties and high sensitivity, thereby completing the present invention.

[0021] That is, the present invention provides the following contents.

[0022] (1) A photosensitive polyimide resin composition comprising (A) a solvent-soluble polyimide and (B) a diazide compound as essential components, wherein the (A) solvent-soluble polyimide is a block copolymer having in its main chain (a) an aromatic tetracarboxylic dianhydride residue having a benzophenone structure and (b) a residue of at least one diamine selected from an aromatic diamine having an alkyl group ortho to an amino group, an aromatic diamine having an indane structure, and a diamine having a polysiloxane structure, and the content of the (B) diazide compound is 2.0 to 150 parts by weight relative to 100 parts by weight of the (A) solvent-soluble polyimide.

[0023] (2) The resin composition described in (1), wherein the residue of the at least one diamine is a residue of an aromatic diamine having a phenylindane structure.

[0024] (3) The resin composition according to (1) or (2), wherein the (B) diazide compound is 2,6-bis(4'-azidobenzylidene)-4-ethylcyclohexanone.

[0025] (4) The resin composition according to any one of (1) to (3), wherein the photosensitive polyimide resin composition further contains (C) an epoxy resin and (D) a photobase generator.

[0026] (5) The resin composition according to any one of (1) to (4), wherein the photosensitive polyimide resin composition is a negative solvent-developable composition.

[0027] (6) A pattern forming method, comprising exposing a substrate coated with the resin composition according to any one of (1) to (5) by ultraviolet irradiation, and removing unexposed portions by development.

[0028] (7) A semiconductor package, an electronic element, a display element or an organic multilayer wiring substrate, comprising an interlayer insulating film, a passivation film or a surface protective film formed using the resin composition according to any one of (1) to (5).

[0029] Effects of the Invention

[0030] According to the present invention, even without using a polyamic acid that needs to be imidized at a high temperature, by using a closed-loop photosensitive polyimide and a specific amount of a diazide compound, a photosensitive polyimide resin composition can be provided that has both solvent solubility during development and solvent insolubility after photocrosslinking, and can achieve good film properties and high sensitivity that are equal to or better than those of a photosensitive polyimide using polyamic acid.

[0031] When a polyimide having a benzophenone skeleton is used, the quantum yield of hydrogen abstraction crosslinking between the benzophenone moiety and the adjacent alkyl group is low and a sufficient crosslinking structure cannot be obtained. However, in the present invention, a sufficient crosslinking structure of the polyimide can be achieved by adding a diazide compound to the polyimide resin composition.

[0032] When the thickness of the film formed using the polyimide resin composition is large, for example, 10 μm or more, a sufficient crosslinking structure can be achieved by adding a photobase generator and an epoxy resin to the polyimide resin composition and photocrosslinking the epoxy resin using the photobase generator. DETAILED DESCRIPTION

[0033] The photosensitive polyimide resin composition of the present invention is a resin composition containing (A) a solvent-soluble polyimide and (B) a diazide compound as essential components.

[0034] (A) Solvent-soluble polyimide

[0035] The solvent-soluble polyimide (A) in the present invention is a block copolymer having in the main chain (a) an aromatic acid dianhydride having a benzophenone structure and at least one diamine (b) selected from (b-1) an aromatic diamine having an alkyl group at the ortho position of the amino group, (b-2) an aromatic diamine having an indane structure, and (b-3) a diamine having a polysiloxane structure.

[0036] Specifically, the solvent-soluble polyimide (A) of the present invention is a block copolymer having at least one, preferably two or more, repeating units represented by the following general formulas [I] to [III].

[0037] [Chemical formula 1]

[0038]

[0039] (Where Z 1 is an aromatic tetracarboxylic dianhydride residue, Ar 1 is an aromatic diamine residue having an alkyl group ortho to the amino group)

[0040] [Chemical formula 2]

[0041]

[0042] (Where Z 2 is an aromatic tetracarboxylic dianhydride residue, Ar 2 is an aromatic diamine residue having an indane structure)

[0043] [Chemical formula 3]

[0044]

[0045] (Where Z 3 is an aromatic tetracarboxylic dianhydride residue, Ar 3 is a diamine residue having a polysiloxane structure)

[0046] In the present invention, Z in the above general formula [I] 1 , Z in the above general formula [II] 2 , Z in the above general formula [III] 3 At least one of the following is (a) an aromatic tetracarboxylic dianhydride residue having a benzophenone structure, preferably Z 1 , Z 2 and Z 3 All of them are (a) aromatic tetracarboxylic dianhydride residues having a benzophenone structure.

[0047] As the aromatic acid dianhydride forming the aromatic acid dianhydride residue having a benzophenone structure (a) in the present invention, 2,2',3,3'-benzophenone tetracarboxylic dianhydride (BTDA), 4,5,3',4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), etc. can be cited. The BTDA-based polyimide also changes its morphology by photocrosslinking. That is, a densification of the condensed state occurs. This also helps to improve chemical resistance and heat resistance.

[0048] It is preferred that the polyimide composition contains 10 mol% or more, 45 mol% or more, and more preferably 50 mol% or more of aromatic acid dianhydride having a benzophenone structure of all aromatic acid dianhydrides constituting the solvent-soluble polyimide. When the content of aromatic acid dianhydride having a benzophenone structure is less than 10 mol%, the solvent resistance of the polyimide resin composition after photocrosslinking decreases, and the sensitivity tends to decrease.

[0049] As Z in the above general formulas [I] to [III] 1 , Z 2 and Z 3Examples of aromatic tetracarboxylic dianhydride residues other than those having a benzophenone structure are not particularly limited, and examples thereof include pyromellitic dianhydride, 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride, bis-(3,4-dicarboxyphenyl)ether dianhydride, 2,2-bis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, and 4,4'-oxydiphthalic dianhydride.

[0050] The solvent-soluble polyimide (A) may have repeating units composed of an aromatic tetracarboxylic dianhydride residue and a diamine residue other than those of the general formulae [I] to [III].

[0051] (b) Diamine

[0052] (b-1) Aromatic diamine having an alkyl group at the ortho position of the amino group

[0053] As the aromatic diamine residue (Ar 1 ), and examples thereof include aromatic diamine residues having a linear or branched alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms, at the ortho position of the amino group. Specifically, examples thereof include residues having structures represented by the following formulae (1) to (3).

[0054] [Chemical formula 4]

[0055]

[0056] In the above formula (1), the free bonds (two bonding positions to which the amino group is bonded) are present at the meta position or the para position relative to each other.

[0057] In the above formula (2), the free bonds (two bonding positions to which the amino groups are bonded) are preferably 11 It exists in the meta or para position, and R5 and R6 are bonded to the two ortho positions of the free bond. 11 It represents -O-, -S-, -SS-, -SO-, -SO2-, -CO-, -COO-, -NH-, -CONH-, -CON-alkyl- (the number of carbon atoms n of the alkyl group is 1 to 6), and -CON-benzyl-.

[0058] In the above formula (3), a free bond (two bonding positions to which the amino group is bonded) exists at the 2-, 3-, 6- or 7-position, and R5 and R6 are bonded at two ortho positions to the free bond.

[0059] In the above formulae (1) to (3), R5 and R6 are linear or branched alkyl groups having 1 to 12 carbon atoms, preferably alkyl groups having 1 to 5 carbon atoms, and more preferably alkyl groups having 1 to 3 carbon atoms.

[0060] In the present invention, it is preferred that the total amount of diamines constituting the solvent-soluble polyimide (A) contain 30 mol % or more, more preferably 50 mol % or more, particularly preferably 70 mol % or more of an aromatic diamine residue having an alkyl group at an ortho position to the amino group (Ar 1 If the content is less than 50 mol %, the crosslinking density tends to decrease.

[0061] (b-2) Aromatic diamine having an indane structure

[0062] In the present invention, the aromatic diamine residue having an indane structure (Ar 2 ) Examples include residues having a structure represented by the following formula (IV) or (V) in the following indane skeleton.

[0063] [Chemical formula 5]

[0064]

[0065] In the above formula (IV), R1 and R2 represent an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkoxyalkyl group having 2 to 12 carbon atoms, and R1 and R2 are preferably bonded to the two ortho positions of the free bond (the two bonding positions of the amino group).

[0066] [Chemical formula 6]

[0067]

[0068] In the above formula (V), R1, R2 and R3 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R4 and R5 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Specific examples include 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane and 6-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane.

[0069] In the present invention, a solvent-soluble polyimide having an aromatic diamine residue having a phenylindane structure represented by the above formula (V) in the main chain is preferred.

[0070] The aromatic diamine residue having an indane structure (Ar) of the present invention is preferably contained in all diamines constituting the solvent-soluble polyimide (A) in an amount of 50 mol % or more, more preferably 60 mol % or more, and particularly preferably 70 mol % or more. 2 If the content is less than 50 mol %, the crosslinking density tends to decrease.

[0071] (b-3) a diamine residue having a polysiloxane structure (Ar 3 )

[0072] As the diamine residue having a polysiloxane structure (Ar 3 ), α,ω-bis(2-aminoethyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, α,ω-bis(4-aminophenyl)polydimethylsiloxane, α,ω-bis(4-amino-3-methylphenyl)polydimethylsiloxane, α,ω-bis(3-aminopropyl)polydiphenylsiloxane, α,ω-bis(4-aminobutyl)polydimethylsiloxane, etc. can be listed.

[0073] The diamine residue having a polysiloxane structure (Ar) of the present invention is preferably contained in the total diamine constituting the solvent-soluble polyimide (A) in an amount of 2.0 to 30 mol %, more preferably 5.0 to 20 mol %. 3 ). If the content of the diamine having a polysiloxane structure exceeds 30 mol %, the solvent solubility may be excessively increased and Tg may tend to be reduced.

[0074] (A) Synthesis method of solvent-soluble polyimide

[0075] The method for synthesizing the solvent-soluble polyimide can be any known method without any particular limitation. The solvent-soluble polyimide can be synthesized by using approximately equal amounts of the above-mentioned tetracarboxylic dianhydride and aromatic diamine, reacting them in an organic polar solvent in the presence of a catalyst and a dehydrating agent at 160 to 200° C. for several hours. As the organic polar solvent, N-methylpyrrolidone (NMP), γ-butyrolactone, N,N'-dimethylacetamide, N,N'-dimethylformamide, dimethyl sulfoxide, tetramethylurea, tetrahydrothiophene-1,1-oxide, etc. can be used.

[0076] The solvent-soluble polyimide (A) in the present invention is a block copolymer, which can be synthesized by block copolymerization as required. For example, it can be prepared by a two-stage stepwise addition reaction, in which a polyimide oligomer is synthesized from tetracarboxylic dianhydride and aromatic diamine in the first stage, and then tetracarboxylic dianhydride and / or aromatic diamine are further added in the second stage to polycondense them, thereby forming a block copolymer polyimide.

[0077] By using a two-component acid-base catalyst that utilizes the equilibrium reaction of lactone as a catalyst for the block copolymerization reaction, the dehydration imidization reaction can be promoted. Specifically, a two-component catalyst of γ-valerolactone and pyridine or N-methylmorpholine is used. As shown in the following formula, water is generated as the imidization proceeds, and the generated water interferes with the equilibrium of the lactone to form an acid-base catalyst and exhibit a catalytic effect.

[0078] [Chemical formula 7]

[0079]

[0080] The water generated by the imidization reaction is removed from the system by azeotropy with a dehydrating agent such as toluene or xylene coexisting in the polar solvent. When the reaction is completed, the water in the solution is removed, and the acid-base catalyst is converted into γ-valerolactone and pyridine or N-methylmorpholine and removed from the system. In this way, a high-purity polyimide solution can be obtained.

[0081] As other two-component catalysts, oxalic acid or malonic acid and pyridine or N-methylmorpholine can be used. In a reaction solution at 160-200°C, oxalate or malonic acid acts as an acid catalyst to promote the imidization reaction. A catalytic amount of oxalic acid or malonic acid remains in the generated polyimide solvent. When the polyimide solution is applied to a substrate and heated to above 200°C to remove the solvent and form a film, the oxalic acid or malonic acid remaining in the polyimide undergoes thermal decomposition as shown in the following formula and is discharged out of the system as a gas.

[0082] [Chemical formula 8]

[0083]

[0084] By the above method, a high-purity solvent-soluble polyimide (A) can be obtained. Oxalic acid-pyridine catalysts are more active than valerolactone-pyridine catalysts and can produce high molecular weight polyimide in a short time.

[0085] The term "solvent-soluble" in the present invention is used with respect to the organic polar solvent used in the synthesis of the polyimide and the solvent used for the film described later, and refers to a polyimide that dissolves 5 g or more in 100 g of the solvent. Here, as the solvent, polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, and tetramethylurea can be cited.

[0086] The (A) solvent-soluble polyimide synthesized as described above can be used in the form of a solution dissolved in the above-mentioned organic polar solvent or the solvent used for the film described later in a manner such that the solid content is 10 to 30% by weight. The molecular weight of the (A) solvent-soluble polyimide is preferably 10,000 to 400,000 in terms of the weight average molecular weight converted to polystyrene. If it is within this range, good solvent solubility, film properties and insulation properties can be achieved. The appropriate viscosity of the (A) solvent-soluble polyimide is preferably 2 to 10 Pa·s / 25°C when the solid content is 20 to 40% by weight. In addition, the glass transition temperature (Tg) (measured by TMA method) of the solvent-soluble polyimide is preferably above 200°C, and more preferably above 250°C.

[0087] The concentration of the (A) solvent-soluble polyimide in the solution is preferably 5 to 50% by weight, and more preferably 10 to 40% by weight. It should be noted that the polyimide obtained by the direct imidization reaction using the catalyst system composed of the above-mentioned lactone and base can be obtained in the form of a solution dissolved in a polar solvent, and the concentration of the polyimide can also be within the above-mentioned preferred range, so the prepared polyimide solution can be preferably used in its original state.

[0088] The prepared polyimide solution can be further diluted with a diluent as needed. As the diluent, a solvent that does not significantly impair solubility can be listed, such as dioxane, dioxolane, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclohexanone, cyclopentanone, propylene glycol monomethyl ether acetate, methyl lactate, anisole, methyl benzoate, ethyl acetate, etc., but it is not particularly limited thereto.

[0089] (B) Diazide compounds

[0090] In the present invention, by adding (B) a diazide compound as another essential component to the photosensitive polyimide resin composition, there is an effect of significantly improving exposure and developability.

[0091] Examples of the diazide compound (B) include 4,4'-diazidebenzylideneacetophenone, 2,6-bis(4'-azidobenzylidene)cyclohexanone, 2,6-bis(4'-azidobenzylidene)-4-methylcyclohexanone, 2,6-bis(4'-azidobenzylidene)-4-ethylcyclohexanone, 2,6-bis(4'-azidobenzylidene)-4-tert-amylcyclohexanone, 4,4'-diazidediphenylsulfone, 4,4'-diazidediphenylether, 4,4'-diazidephenylsulfide, and 4,4'-diazidediphenylmethane. Among them, those having an azidobenzylidenecyclohexanone structure are preferred, and 2,6-bis(4'-azidobenzylidene)-4-ethylcyclohexanone is particularly excellent from the viewpoint of crosslinking properties and storage stability.

[0092] In the photosensitive polyimide resin composition, the (B) diazide compound is preferably contained in an amount of 2.0 to 150 parts by weight, more preferably 5.0 to 100 parts by weight, and particularly preferably 10.0 to 80 parts by weight relative to 100 parts by weight of the (A) solvent-soluble polyimide. If it is less than 2.0 parts by weight, the crosslinking density tends to decrease, and if it exceeds 150 parts by weight, the film properties tend to decrease. In order to compensate for the crosslinking property, a diaziridine compound, maleimide or bismaleimide compound may also be used in combination.

[0093] Since the light transmittance of the photosensitive polyimide resin composition of the present invention is poor on the low wavelength side, the pattern shape is easily formed into an inverted cone visible in negative solvent development, especially in the case of thick film specifications. In order to improve this situation, it was found that the use of photosensitive monomers or polymers with different photosensitive crosslinking methods is also effective. Among them, it was found that the combination of (C) epoxy resin and (D) photobase generator with excellent compatibility with the photosensitive polyimide resin composition is particularly effective as a component of the photosensitive polyimide resin composition of the present invention.

[0094] (C) Epoxy resin

[0095] The epoxy resin (C) is not particularly limited and can be selected based on the reactivity with the photobase generator or the compatibility with the photosensitive polyimide resin composition. For example, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, epoxy resin containing a triazine skeleton, epoxy resin containing a fluorene skeleton, naphthalene epoxy resin, biphenyl epoxy resin, crystalline epoxy resin, bisphenol A epoxy resin, etc. can be used as epoxy resins, and high molecular weight epoxy resins thereof can also be used. The content of the epoxy resin (C) in the photosensitive polyimide resin composition is preferably 2 to 50 parts by weight, and most preferably 2 to 20 parts, relative to 100 parts by weight of the solvent-soluble polyimide (A).

[0096] (D) Photobase Generator

[0097] (D) Photobase generators are components that generate anions (bases) by irradiation with ultraviolet rays, and are roughly divided into nonionic and ionic types. Nonionic types include photobase generators that absorb light to generate primary or secondary amines, imidazoles, etc., while ionic types include photobase generators that generate strong organic bases such as amidines, guanidines, and phosphazenes.

[0098] Among the photobase generators (D), those that generate primary or secondary amines in the reaction with the epoxy resin (C) are less likely to undergo a chain reaction. Therefore, nonionic photobase generators that generate imidazoles are preferred, while ionic photobase generators that generate amidines, guanidines, and the like are preferred.

[0099] As the photobase generator (D) in the present invention, commercially available products may be used, for example, WPBG-018, WPBG-140, WPBG-266, WPBG-300, WPBG-345, WPBG-027, WPBG-165 (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and the like.

[0100] The content of the photobase generator (D) in the photosensitive polyimide resin composition is preferably 0.5 to 8% by weight, more preferably 1 to 6% by weight, based on the epoxy resin (C).

[0101] (Photosensitizer)

[0102] In the photosensitive polyimide resin composition of the present invention, in order to suit the respective end uses, a photosensitizer may be contained to improve the sensitivity of pattern resolution. As a photosensitizer, a photosensitizer that works on the long wavelength (>350nm) side is particularly preferred. As a photosensitizer, for example, anthracene sensitizers, thioxanthone sensitizers, etc. can be listed. The content of the photosensitizer is preferably about 0.3 to 2 weight % relative to the photosensitive polyimide resin composition.

[0103] Specific examples of anthracene sensitizers include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diisopropoxyanthracene, 9,10-dibutoxyanthracene, 9,10-dipentyloxyanthracene, 9,10-dihexyloxyanthracene, 9,10-bis(2-methoxyethoxy)anthracene, 9,10-bis(2-ethoxyethoxy)anthracene, 9,10-bis(2-butoxyethoxy)anthracene, 9,10-bis(3-butoxyethoxy)anthracene, 2-methyl- or 2-ethyl-9,10-dipropoxyanthracene, 2-methyl- or 2-ethyl-9,10-diisopropoxyanthracene, 2-methyl- or 2-ethyl-9,10-dibutoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipentyloxyanthracene, 2-methyl- or 2-ethyl-9,10-dihexyloxyanthracene, and the like.

[0104] As the anthracene-based sensitizer, a commercially available product may be used, and examples of the commercially available product include "Anthracure UVS-1331", "Anthracure UVS-1101", and "Anthracure UVS-1221" (all manufactured by Kawasaki Chemical Industries, Ltd.).

[0105] In addition, as thioxanthone-based sensitizers, for example, 2-isopropyl thioxanthone, 4-isopropyl thioxanthone, 2,4-diethyl thioxanthone, chloropropoxy thioxanthone, etc. can be listed. As thioxanthone-based sensitizers, commercially available products can be used. As commercially available products, for example, "KAYACURE DETX-S" (manufactured by Nippon Kayaku Co., Ltd.), "Speedcure ITX", "Speedcure DETX", "Speedcure CPTX" (the above are manufactured by LAMBSON Co., Ltd.) and the like can be listed.

[0106] (Other additives)

[0107] The photosensitive polyimide resin composition of the present invention may contain modifiers commonly used in photosensitive polyimide resin compositions, such as coupling agents, plasticizers, film-forming resins, surfactants, stabilizers, and spectral sensitivity regulators. In particular, when the adhesion of polyimide to the substrate is poor, the adhesion to the substrate can be improved by adding a coupling agent, in particular, a silane coupling agent such as vinyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, p-phenylvinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, tris-(trimethoxysilylpropyl)isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, hexamethyldisiloxane, hexamethyldisilazane, 1,3-bis(3-aminopropyl)tetramethyldisiloxane, N-[3-(triethoxysilyl)propyl]o-carboxybenzamide, etc. In this case, the amount of the silane coupling agent added is preferably 0.1 to 5% by weight of the photosensitive polyimide resin composition.

[0108] In addition, when a substrate composed of copper or a copper alloy is used, an azole compound may be mixed in the photosensitive polyimide resin composition in order to suppress discoloration of the substrate. As the azole compound, for example, 1H-benzotriazole, tolylbenzotriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 5-carboxyl-1H-benzotriazole and 4-carboxyl-1H-benzotriazole can be listed. In this case, the addition amount of the azole compound is preferably 0.1 to 1% by weight of the photosensitive polyimide resin composition.

[0109] Furthermore, in order to suppress discoloration on copper, a hindered phenol compound may be blended into the photosensitive polyimide resin composition.

[0110] Examples of the hindered phenol compound include 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-tert-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, and 1,3,5-tris(4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.

[0111] In this case, the amount of the hindered phenol compound added is preferably 0.1 to 2% by weight of the photosensitive polyimide resin composition. Other resins that can be used together include polyacrylate resins and polyethersulfone resins.

[0112] The photosensitive polyimide resin composition of the present invention can be prepared in the form of a solution suitable for application on a substrate. In this case, as a solvent, a polar solvent such as N-methyl-2-pyrrolidone, γ-butyrolactone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, tetramethylurea, etc., which is used as a solvent for imidization reaction, can be used.

[0113] Method for preparing photosensitive polyimide pattern

[0114] The photosensitive polyimide resin composition containing the above-mentioned components can be used to prepare a photosensitive polyimide pattern on a substrate. Specifically, the photosensitive polyimide pattern can be prepared by a method comprising the following steps: (1) a step of forming a resin layer on the substrate by coating the above-mentioned photosensitive polyimide resin composition of the present invention on the substrate; (2) a step of exposing the resin layer; (3) a step of developing the exposed resin layer to form a photosensitive polyimide pattern such as an insulating material of an electronic component and a passivation film, a buffer coating film, and an interlayer insulating film in a semiconductor package; and (4) a step of forming a permanent insulating film by heating the photosensitive polyimide pattern.

[0115] Hereinafter, a typical embodiment of each step will be described.

[0116] (1) A step of forming a resin layer on a substrate by coating a photosensitive resin composition on the substrate:

[0117] In this step, the photosensitive resin composition of the present invention is applied to a substrate such as a silicon wafer, a metal substrate, a ceramic substrate, an organic substrate, and then dried as needed to form a resin layer. As the coating method, a conventional method for coating a photosensitive resin composition can be used, for example, a method of coating with a spin coater, a bar coater, a knife coater, a curtain coater, a screen printer, etc., a method of spray coating with a spray coater, etc.

[0118] The coating film formed by the photosensitive resin composition can be dried as needed. As the drying method, air drying, heating drying using an oven or a hot plate, vacuum drying, etc. can be used. Specifically, in the case of air drying or heating drying, the drying can be performed at 20 to 140° C. for 1 to 30 minutes. As long as the various properties of the photosensitive resin composition of the present invention are not impaired, it is not limited to this range.

[0119] (2) Process of exposing the resin layer:

[0120] In this process, the resin layer formed in the above step (1) is exposed by using an exposure device such as a contact alignment exposure machine, a mirror projection exposure machine, a stepper, etc., through a photomask or a reticle having a pattern or directly using an ultraviolet light source. Then, in order to improve photosensitivity, etc., a post-exposure bake and / or a pre-development bake can be implemented using any combination of temperature and time as needed. The range of the baking conditions is preferably a temperature of 40 to 120° C. and a time of 10 to 240 seconds, but it is not limited to this range as long as the various properties of the photosensitive resin composition of the present invention are not impaired.

[0121] (3) A step of developing the exposed resin layer to form a photosensitive polyimide pattern:

[0122] In this step, the unexposed portion of the photosensitive resin layer after exposure is developed and removed. As a developing method, any method can be selected from conventionally known photoresist developing methods, such as a rotary spray method, a paddle method, and an immersion method accompanied by ultrasonic treatment. In addition, after development, in order to adjust the shape of the photosensitive polyimide pattern, etc., post-development baking can be performed using any combination of temperature and time as needed.

[0123] As the developer used for development, a good solvent for the photosensitive resin composition or a combination of the good solvent and a poor solvent is preferred. For example, as a good solvent, N-methylpyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, etc. are preferred. As a poor solvent, toluene, xylene, methanol, ethylene glycol, isopropanol, ethyl lactate and propylene glycol methyl ether acetate, etc. are preferred. When a good solvent and a poor solvent are mixed for use, it is preferred to adjust the ratio of the poor solvent to the good solvent according to the solubility of the polymer in the photosensitive resin composition. In addition, for each of the good solvent and the poor solvent, two or more solvents, for example, several combinations, may also be used.

[0124] (4) Process of forming a permanent insulating film by heating the photosensitive polyimide pattern:

[0125] In this process, a permanent insulating film is formed by heating the photosensitive polyimide pattern obtained by the above-mentioned development. That is, unlike the polyamic acid type, since imidization has been completed, a permanent insulating film can be formed by removing the residues such as the solvent. As a method of heat curing, various methods can be selected, such as a method using a hot plate, a method using an oven, and a method using a temperature-raising oven with a settable temperature program. Heating can be carried out under sufficient conditions to evaporate the solvent, for example, at 150~250°C for about 30 minutes to 2 hours. As the atmosphere gas during heating, air can be used, and inert gases such as nitrogen and argon can also be used.

[0126] The photosensitive polyimide pattern formed as described above can be used as an interlayer insulating film, a passivation film, or a surface protective film of a semiconductor package, an electronic element, a display element, or an organic multilayer wiring substrate. Example

[0127] Hereinafter, the present invention will be described in detail using Examples, but the present invention is not limited thereto.

[0128] (Synthesis of Block Copolymer Polyimide)

[0129] Synthesis Example 1

[0130] A stirrer, a nitrogen inlet tube, and a cooling tube with a water receiver were installed in a glass detachable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 29.23 g (0.1 mol) of 1,3-bis(3-aminophenoxy)benzene, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. During the reaction, the azeotropic component of toluene-water was removed.

[0131] After cooling to room temperature, 48.33g (0.15 mol) of BTDA, 44.57g (0.25 mol) of 2,4-diethyl-6-methyl-1,3-phenylenediamine (aromatic diamine with alkyl groups at the ortho position relative to N-), 360g of NMP, and 90g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While excluding the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution with a solid content of 20% by weight.

[0132] Synthesis Example 2

[0133] A stirrer, a nitrogen inlet tube, and a cooling tube with a moisture receiver were installed in a glass detachable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 29.23 g (0.1 mol) of 1,3-bis(3-aminophenoxy)benzene, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0134] After cooling to room temperature, 48.33 g (0.15 mole) of BTDA, 51.08 g (0.25 mole) of 5,7-diamino-1,1,4,6-tetramethylindane (aromatic diamine having an alkyl group at the ortho position relative to N-), 360 g of NMP, and 90 g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While excluding the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

[0135] Synthesis Example 3

[0136] A stirrer, a nitrogen inlet tube, and a cooling tube with a moisture receiver were installed in a glass detachable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 29.23 g (0.1 mol) of 1,3-bis(3-aminophenoxy)benzene, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0137] After cooling to room temperature, 44.13g (0.15 mole) of 3,4,3',4'-biphenyltetracarboxylic dianhydride, 44.57g (0.25 mole) of 2,4-diethyl-6-methyl-1,3-phenylenediamine (aromatic diamine with alkyl groups at the ortho position relative to N-), 360g of NMP, and 90g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While excluding the azeotropic reflux of water-toluene from the system, heated and stirred at 180°C for 2 hours and 30 minutes to terminate the reaction. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution with a solid content of 20% by weight.

[0138] Synthesis Example 4

[0139] A stirrer, a nitrogen inlet tube, and a cooling tube equipped with a moisture receiver were installed in a glass separable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 26.64 g (0.1 mol) of 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane (aromatic diamine containing a phenylindane structure), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0140] After cooling to room temperature, 48.33 g (0.15 mol) of BTDA, 66.60 g (0.25 mol) of 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, 360 g of NMP, and 90 g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While evacuating the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

[0141] Synthesis Example 5

[0142] A stirrer, a nitrogen inlet tube, and a cooling tube equipped with a moisture receiver were installed in a glass separable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 12.22 g (0.1 mol) of 2,4-diaminotoluene (aromatic diamine having an alkyl group at the ortho position relative to N-), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0143] After cooling to room temperature, 48.33 g (0.15 mol) of BTDA, 66.60 g (0.25 mol) of 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, 360 g of NMP, and 90 g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While evacuating the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

[0144] Synthesis Example 6

[0145] A stirrer, a nitrogen inlet tube, and a cooling tube equipped with a moisture receiver were installed in a glass separable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 15.98 g (0.06 mol) of 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, 9.94 g (0.04 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and the mixture was stirred at room temperature for 30 minutes, then heated to 180°C and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0146] After cooling to room temperature, 48.33 g (0.15 mol) of BTDA, 66.60 g (0.25 mol) of 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, 360 g of NMP, and 90 g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While evacuating the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

[0147] Synthesis Comparative Example 1

[0148] A stirrer, a nitrogen inlet tube, and a cooling tube with a water receiver were installed in a glass detachable three-necked flask. 58.84 g (0.2 mol) of 3,4,3',4'-biphenyltetracarboxylic dianhydride, 29.23 g (0.1 mol) of 1,3-bis(3-aminophenoxy)benzene, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0149] After cooling to room temperature, 48.33g (0.15 mole) of 3,4,3',4'-benzophenone tetracarboxylic dianhydride, 44.57g (0.25 mole) of 2,4-diethyl-6-methyl-1,3-phenylenediamine (aromatic diamine with alkyl groups at the ortho position relative to N-), 360g of NMP, and 90g of toluene were added, and stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While excluding the azeotropic reflux of water-toluene from the system, heated and stirred at 180°C for 2 hours and 30 minutes to terminate the reaction. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution with a solid content of 20% by weight.

[0150] Synthesis Comparative Example 2

[0151] A stirrer, a nitrogen inlet tube, and a cooling tube equipped with a moisture receiver were installed in a glass separable three-necked flask. 64.45 g (0.2 mol) of 3,4,3',4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA), 12.22 g (0.1 mol) of 2,4-diaminotoluene (aromatic diamine having an alkyl group at the ortho position relative to N-), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were added, and stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, and then heated to 180°C and heated and stirred for 1 hour. The azeotropic component of toluene-water was removed during the reaction.

[0152] After air cooling, 48.33 g (0.15 mol) of BTDA, 73.08 g (0.25 mol) of 1,3-bis(3-aminophenoxy)benzene (aromatic diamine containing aromatic ether bonds), 360 g of NMP, and 90 g of toluene were added, stirred at room temperature for 30 minutes, and then heated to 180°C and heated and stirred for 1 hour. While evacuating the azeotropic reflux of water-toluene from the system, the reaction was terminated by heating and stirring at 180°C for 2 hours and 30 minutes. NMP was added to the obtained product for dilution to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

[0153] (Preparation of Photosensitive Polyimide Resin Composition)

[0154] In the following Examples and Comparative Examples, "parts" means "parts by weight".

[0155] Embodiment 1~6

[0156] 20 parts of 2,6-bis(4'-azidobenzylidene)-4-ethylcyclohexanone, 1 part of 9,10-dibutoxyanthracene, 1 part of 3-glycidyloxypropylmethyldimethoxysilane, 0.1 part of 5-methyl-1H-benzotriazole, and 1 part of 1,3,5-tris(4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione were added to 500 parts of the block copolymer polyimide solution of Synthesis Examples 1 to 6 (solid content: 20% by weight), and dissolved in methyl benzoate to prepare a photosensitive resin composition with a solid content of 20%.

[0157] Example 7

[0158] In Example 1 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner except that 2,6-bis(4′-azidobenzylidene)-4-methylcyclohexanone was used instead of 2,6-bis(4′-azidobenzylidene)-4-ethylcyclohexanone.

[0159] Example 8

[0160] In Example 1 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner as in Example 1 except that 4,4′-diazidebenzylideneacetophenone was used instead of 2,6-bis(4′-azidobenzylidene)-4-ethylcyclohexanone.

[0161] Example 9

[0162] In Example 1 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner as in Example 1 except that 16.7 parts of YX-6954BH30 (polymer epoxy resin: manufactured by Mitsubishi Chemical Corporation) and 0.25 parts of WPBG-300 (photobase generator: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were further added.

[0163] Example 10

[0164] In Example 1 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner except that 5 parts of TEPIC-VL (trifunctional epoxy resin: manufactured by Nissan Chemical Industries, Ltd.) and 0.25 parts of WPBG-300 (photobase generator: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were further added.

[0165] Comparative Example 1

[0166] In Example 7 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner except that 2,6-bis(4′-azidobenzylidene)-4-methylcyclohexanone was not used.

[0167] Comparative Example 2

[0168] In Example 7 (using the polyimide solution of Synthesis Example 1), a photosensitive resin composition was prepared in the same manner except that 1.5 parts of 2,6-bis(4′-azidobenzylidene)-4-methylcyclohexanone was used instead of 20 parts.

[0169] (Evaluation of performance of polyimide resin composition)

[0170] 1. Mechanical strength, thermal expansion coefficient and 5% thermal weight loss temperature

[0171] The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 2 were spin-coated on a 6-inch silicon wafer so that the film thickness after final drying was 15 to 17 μm, and pre-baked at 90° C. for 360 seconds. Then, a high-pressure mercury lamp was used to perform an i-line treatment at 2,500 mJ / cm 2The film was exposed to full wavelength, immersed in a cyclopentanone solution for 120 seconds, and then heated and dried at 200° C. (or 180° C.) for 90 minutes to produce a dry resin film.

[0172] The resin dry film was peeled off from the wafer using hydrofluoric acid and used as a test sample for measuring mechanical strength, thermal expansion coefficient and 5% thermal weight loss temperature.

[0173] 2. Sealing strength

[0174] The dried resin film formed on the silicon wafer produced as described above was used.

[0175] (1) Use a cutter to make 11 cuts on the test surface that reach the substrate, creating a grid of 100. Use a cutter guide to set the cuts to 1 mm apart.

[0176] (2) Cellotape (registered trademark) is strongly pressed onto the grid portion, the ends of the tape are peeled off at a 45° angle, and the grid state is compared with the standard chart for evaluation. The adhesion strength is determined in normal conditions and after 240 hours under HAST (Highly Accelerated Aging Test, 80°C × 85% RH).

[0177] 3. Residual film rate

[0178] The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 2 were spin-coated on a 6-inch silicon wafer so that the film thickness after final drying was 5 to 7 μm and 10 to 12 μm, respectively, and pre-baked at 90° C. for 240 seconds and 90° C. for 300 seconds, and then the thickness (t1) was measured using a film thickness meter. Next, a high-pressure mercury lamp was used to perform a 1,000 (or 2,500) mJ / cm 2 The film was exposed to full wavelength and immersed in cyclopentanone solution for 120 seconds, and then the thickness (t2) was measured with a film thickness meter. Then, the film was dried at 200°C (or 180°C) for 90 minutes, and then the thickness (t3) was measured with a film thickness meter. From these measured values, t2 / t1, t3 / t1 and t3 / t2 were calculated as the residual film rate.

[0179] 4. Exposure / developability

[0180] The pattern evaluation was performed by the following method.

[0181] (1) Resolution

[0182] The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 2 were dripped onto a 6-inch silicon wafer and spin-coated for 30 seconds, followed by pre-baking on a 90°C hot plate for 240 seconds. At this time, the coating rotation was adjusted so that the film thickness after baking was about 6 to 8 μm. Next, exposure was performed using a high-pressure mercury lamp. The exposure amount measured by i-line was 1,000 mJ / cm 2 Then, it was developed with cyclopentanone, rinsed, and then dried at 200°C (or 180°C) for 90 minutes. The smallest resolution was taken as the resolution in L / S=5 / 5, 10 / 10, 15 / 15, 20 / 20, 30 / 30, 50 / 50μm and square through hole pattern 10, 15, 20, 30, 40, 50μm.

[0183] (2) Residues and cracks on the pattern edges

[0184] Pattern processing was performed in the same manner as in (1) above. First, the film surface after development was visually observed for abnormalities. Next, a 15 μm square through-hole pattern was observed using an optical microscope, and cracks were recorded as cracks at the corners of the pattern. The pattern edge at L / S = 15 / 15 was further observed, and the presence of development residues was recorded as residues.

[0185] The evaluation results of the resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 2 are shown in Tables 1 and 2 below. In the evaluation of the residual film rate and the exposure developability, if the resin compositions obtained in Comparative Examples 1 to 2 are immersed in a cyclopentanone solution after exposure, the film dissolves. This result indicates that the resin compositions obtained in Comparative Examples 1 to 2 do not have good solvent insolubility after photocrosslinking. Therefore, the Tg, thermal expansion coefficient, 5% thermal weight loss temperature, mechanical strength, and adhesion strength of the resin compositions obtained in Comparative Examples 1 to 2 were evaluated by making samples without immersing the resin compositions in a cyclopentanone solution. On the other hand, it is known that the resin compositions obtained in Examples 1 to 10 achieve good film properties and high sensitivity while having both solvent solubility during development and solvent insolubility after photocrosslinking.

[0186]

[0187]

[0188] Industrial Applicability

[0189] The negative photosensitive polyimide resin composition of the present invention can be used, for example, to prepare semiconductor packages such as FO-WLP and WLP, electronic components such as thin film magnetic elements such as thin film magnetic heads, thin film sensors, and common mode choke coils, display elements such as TFT liquid crystal elements, color filter elements, and organic EL elements, and organic multilayer wiring substrates, and can be suitably used in the field of photosensitive materials.

Claims

1. A photosensitive polyimide resin composition comprising (A) a solvent-soluble polyimide and (B) a diazide compound as essential components, wherein: The solvent-soluble polyimide (A) is a block copolymer having in its main chain (a) an aromatic tetracarboxylic dianhydride residue having a benzophenone structure and (b) a residue of at least one diamine containing an aromatic diamine having a phenylindane structure represented by formula (V), In the above formula (V), R1, R2 and R3 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R4 and R5 independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, The content of the (B) diazide compound is 2.0 to 150 parts by weight relative to 100 parts by weight of the (A) solvent-soluble polyimide. The photosensitive polyimide resin composition is a negative solvent developing composition.

2. The resin composition according to claim 1, characterized in that The residue of at least one diamine further includes a residue of an aromatic diamine having an alkyl group at an ortho position to the amino group and / or a diamine having a polysiloxane structure.

3. The resin composition according to claim 1 or 2, characterized in that The (B) diazide compound is 2,6-bis(4'-azidobenzylidene)-4-ethylcyclohexanone.

4. The resin composition according to claim 1 or 2, characterized in that The photosensitive polyimide resin composition further contains (C) an epoxy resin and (D) a photobase generator.

5. A pattern forming method, characterized in that: The substrate coated with the resin composition according to any one of claims 1 to 4 is exposed by ultraviolet irradiation, and the unexposed portion is removed by development.

6. A semiconductor package, an electronic element, a display element or an organic multilayer wiring substrate, comprising an interlayer insulating film, a passivation film or a surface protective film formed using the resin composition according to any one of claims 1 to 4.

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