TWI768051B - Photosensitive resin composition, dry film, cured product, printed wiring board, and semiconductor element - Google Patents

Abstract

An object of the present invention is to provide a photosensitive resin composition, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, a printed wiring board having the cured product, and Semiconductor element, the photosensitive resin composition is especially a thick photosensitive film (for example, 5 μm or more) on a metal-coated substrate, which is excellent in development and resolution, and the pattern shape after development is good ones. The solution is a photosensitive resin composition containing (A) a polybenzoxazole precursor and (B) a sensitizer, a dry film using the same, a cured product, a printed wiring board and a semiconductor element. , (C) a thiol compound, and, (D) at least any one of a urea compound and a melamine-based compound.

Description

Photosensitive resin composition, dry film, cured product, printed wiring board, and semiconductor element

The present invention relates to a photosensitive resin composition, a dry film, a cured product, a printed wiring board, and a semiconductor element.

As a photosensitive resin composition that can be developed with an aqueous alkaline solution, a composition containing a photoacid generator such as a polybenzoxazole (hereinafter, also referred to as "PBO") precursor and a naphthoquinonediazide compound is used thing. Polybenzoxazole cured products obtained by thermally curing such a composition have excellent heat resistance and electrical insulating properties, so they are gradually becoming suitable for surface protection films or interlayer insulating films of electrical materials, such as coating films for semiconductor elements. , or electronic components such as flexible printed wiring board materials, heat-resistant insulating interlayer materials, etc.

Regarding the photosensitive resin composition using polybenzoxazole, for example, Patent Document 1 discloses that the polystyrene is used for the purpose of preventing the formation of post-development residues (hereinafter, also referred to as "scum") on copper-coated wafers. A photosensitive resin composition in which a pyrimidine skeleton compound containing an S atom is blended with the oxazole precursor polymer. In addition, Patent Document 2 discloses that, for the purpose of providing a positive-type photosensitive polymer composition with high sensitivity and good pattern shape and residual film ratio of unexposed parts, a composition selected from predetermined polyurethanes having Polyimide obtained from phenolic hydroxyl diamine and tetracarboxylic acid, its anhydride or its derivative as raw material, and base of polybenzoxazole precursor obtained from dicarboxylic acid and dihydroxydiamine as raw material An aqueous solution-soluble polymer containing a dissolution inhibitor selected from the group consisting of onium salts, diaryl compounds, and tetraalkylammonium salts together with the o-quinonediazide compound. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4759613 [Patent Document 2] Japanese Patent No. 3509612

[The problem to be solved by the invention]

However, according to the technique disclosed in Patent Document 1, when a coating film obtained by coating a positive-type photosensitive resin composition on a copper-coated wafer and firing it is exposed and developed, it is possible to obtain a post-development However, in order to achieve the effect of promoting dissolution, the unexposed part dissolves too quickly, and the cross-sectional shape of the pattern after development becomes round and thin, and the residual film rate is also low. A condition in which the forming step has an adverse effect. In addition, according to the technique disclosed in Patent Document 2, when a coating film obtained by coating a positive-type photosensitive resin composition on a silicon substrate and drying it is exposed and developed, the residual film after development can be improved. However, since the coating film obtained above has the effect of inhibiting dissolution on the metal substrate, the removal of the coating film on the exposed part is not sufficient, and a large amount of dross remains on the metal substrate. In addition, it is also known to control the pattern shape on a silicon substrate by adding a plasticizer or a cross-linking agent, etc., but it cannot achieve good results on a metal substrate.

Therefore, an object of the present invention is to provide a photosensitive resin composition, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, and a printed wiring including the cured product Plates and semiconductor elements, the photosensitive resin composition is especially a thick photosensitive film (for example, 5 μm or more) on a metal-coated substrate, which is excellent in development and resolution, and the pattern after development The shape is good. [means to solve the problem]

As a result of careful studies, the present inventors found that the above problems can be solved by blending a thiol compound with a PBO precursor and at least any one of a urea compound and a melamine compound, and completed the present invention.

That is, the photosensitive resin composition of the present invention is characterized by containing (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a thiol compound, and (D) a urea compound and a melamine compound. at least any of them.

The dry film of the present invention is characterized by having a resin layer obtained by applying the photosensitive resin composition on the film and drying it.

The cured product of the present invention is characterized by being composed of the photosensitive resin composition or the resin layer of the dry film.

The printed wiring board and the semiconductor element of the present invention are characterized by having the above-mentioned cured product. [Effect of invention]

According to the present invention, there can be provided a photosensitive resin composition, a dry film having a resin layer obtained from the composition, a cured product of the composition or the resin layer of the dry film, a printed wiring board having the cured product, and Semiconductor element, the photosensitive resin composition is especially a thick photosensitive film (for example, 5 μm or more) on a metal-coated substrate, which is excellent in development and resolution, and the pattern shape after development is good ones.

Hereinafter, embodiments of the present invention will be described in detail. The photosensitive resin composition of the present invention contains (A) a polybenzoxazole precursor, (B) a photosensitizer, (C) a thiol compound, and (D) at least any one of a urea compound and a melamine compound. By adding at least any of the (C) thiol compound, which is easy to interact with the metal due to its isolated electron pair, and the (D) urea compound and melamine-based compound, which have the effect of inhibiting dissolution, by adding the photosensitive PBO precursor in combination. One, it can suppress the generation of dross and obtain a photosensitive resin composition with excellent resolution, especially for thick photosensitive films (eg, 5 μm or more) on metal-coated substrates. According to the photosensitive resin composition of the present invention, the cross-sectional shape of the line pattern after development does not become thin or round, and the cross-sectional shape can be maintained in a tapered shape (trapezoid shape to square shape) in a good pattern shape.

First, each component contained in the photosensitive resin composition of the present invention will be described in detail.

[(A) Polybenzoxazole Precursor] The photosensitive resin composition of the present invention contains (A) a polybenzoxazole precursor. The method for synthesizing the (A) polybenzoxazole precursor is not particularly limited, and it may be synthesized by a known method. For example, it can be obtained by reacting dihydroxydiamines as an amine component with a dihalide of a dicarboxylic acid such as dicarboxylic acid dichloride as an acid component.

(式中，X表示4價之有機基，Y表示2價之有機基。n為1以上之整數，以10～50為佳，較佳為20～40。)(A) The polybenzoxazole precursor is preferably a polyhydroxyamic acid having a repeating structure represented by the following formula (1).

(In the formula, X represents a tetravalent organic group, and Y represents a divalent organic group. n is an integer of 1 or more, preferably 10 to 50, more preferably 20 to 40.)

When the (A) polybenzoxazole precursor is synthesized by the above synthesis method, in the general formula (1), X is the residue of the aforementioned dihydroxydiamine, and Y is the residue of the aforementioned dicarboxylic acid.

As said dihydroxydiamines, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, Bis(3-amino-4-hydroxyphenyl)propane, Bis(4-amino-3-hydroxyphenyl)propane, Bis(3-amino-4-hydroxyphenyl)propane, Bis(4-amine) 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis( 4-amino-3-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, etc. Among them, 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane is preferred.

As said dicarboxylic acid, isophthalic acid, terephthalic acid, 5-tert-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2 ,6-Naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis(4-carboxyphenyl) Di, 2,2-bis(p-carboxyphenyl)propane, 2,2-bis(4-carboxyphenyl)-1,1,1,3,3,3-hexafluoropropane, etc. with aromatic rings Aliphatic systems such as dicarboxylic acid, oxalic acid, malonic acid, succinic acid, 1,2-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, etc. Dicarboxylic acid. Among them, 4,4'-dicarboxydiphenyl ether is preferred.

In the aforementioned general formula (1), the 4-valent organic group represented by X can be an aliphatic group or an aromatic group, but an aromatic group is preferred, and two hydroxyl groups and two amine groups are in the ortho position. The method is preferably located on the aromatic ring. The number of carbon atoms of the tetravalent aromatic group is preferably 6-30, more preferably 6-24. Specific examples of the above-mentioned tetravalent aromatic group include the following groups, but the group is not limited to these, and known aromatic groups that can be included in the polybenzoxazole precursor can be selected according to the application. base.

Among the above-mentioned aromatic groups, the above-mentioned tetravalent aromatic group is preferably the following group.

In the aforementioned general formula (1), the divalent organic group represented by Y may be an aliphatic group or an aromatic group, preferably an aromatic group, so that the aromatic group is the same as the one in the aforementioned general formula (1) on the aromatic ring. Carbonyl bonding is preferred. The number of carbon atoms of the divalent aromatic group is preferably 6-30, more preferably 6-24. Specific examples of the above-mentioned divalent aromatic group include the following groups, but the group is not limited to these, and a well-known aromatic group contained in the polybenzoxazole precursor can be selected according to the application. Can.

(式中，A表示選自由單鍵、-CH₂ -、-O-、-CO-、-S-、-SO₂ -、-NHCO-、-C(CF₃ )₂ -、-C(CH₃ )₂ -所成群之2價之基。)

(wherein, A represents a single bond, -CH ₂ -, -O-, -CO-, -S-, -SO ₂ -, -NHCO-, -C(CF ₃ ) ₂ -, -C(CH ₃ ) ₂ - The base of the 2 valence of the group.)

Among the above-mentioned aromatic groups, the above-mentioned divalent organic group is preferably the following group.

(A) The polybenzoxazole precursor may contain a repeating structure of two or more kinds of the above-mentioned polyhydroxyamic acid. Moreover, the structure other than the repeating structure of the above-mentioned polyhydroxyamic acid may be included, for example, the repeating structure of a polyamic acid may be included.

(A) The number average molecular weight (Mn) of the polybenzoxazole precursor is preferably 5,000 to 100,000, more preferably 8,000 to 50,000. Here, the number average molecular weight is a value measured by GPC and converted to standard polystyrene. Moreover, the mass average molecular weight (Mw) of the (A) polybenzoxazole precursor is preferably 10,000 to 200,000, more preferably 16,000 to 100,000. Here, the mass average molecular weight is a value measured by GPC and converted to standard polystyrene. Mw/Mn is preferably 1-5, more preferably 1-3.

(A) Polybenzoxazole precursor system may be used individually by 1 type, and may be used in combination of 2 or more types. (A) The compounding quantity of the polybenzoxazole precursor is preferably 30 to 95 mass %, preferably 50 to 90 mass %, based on the total solid content of the composition.

[(B) Sensitizer] The (B) sensitizer is not particularly limited, and for example, a photoacid generator, a photopolymerization initiator, or a photobase generator can be used. Photoacid generators are compounds that generate acids by irradiation with light such as ultraviolet rays or visible light, photopolymerization initiators are compounds that generate radicals, etc., by irradiation with the same light, and photobase generators are generated by the same light. The molecular structure changes when irradiated, or a compound of one or more basic substances is generated by molecular cleavage. In the present invention, as the (B) photosensitizer, a photoacid generator can be suitably used.

As the photoacid generator, for example, naphthoquinone diazide compounds, diaryl perionium salts, triaryl perionium salts, dialkylbenzyl methyl perionium salts, diaryl iodonium salts, and aryl diazonium salts can be mentioned. , Aromatic tetracarboxylic acid ester, aromatic sulfonic acid ester, nitrobenzyl ester, aromatic N-oxyimide sulfonic acid ester, aromatic sulfonic acid amide, benzoquinone diazosulfonic acid ester, etc. The photoacid generator is preferably a dissolution inhibitor. Among them, naphthoquinonediazide compounds are preferred.

As the naphthoquinone diazide compound, specifically, for example, a naphthoquinone diazide adduct of ginseng (4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (for example, Sanbao Institute of Chemistry) can be used. TS533, TS567, TS583, TS593 manufactured by the company), or naphthoquinone diazide adduct of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sanbao Chemical Research Institute), or 4-{4 -Naphthoquinone diazide adduct of -[1,1-bis(4-hydroxyphenyl)ethyl]-α,α-dimethylbenzyl}phenol (for example, TKF- 428, TKF-528) and so on.

In addition, as the photopolymerization initiator, those known and customary can be used. For example, an oxime ester-based photopolymerization initiator having an oxime ester group, an α-aminoacetophenone-based photopolymerization initiator, an acyl group can be used. Phosphine oxide-based photopolymerization initiators, titanocene-based photopolymerization initiators, and the like.

Commercially available examples of the oxime ester-based photopolymerization initiator include CGI-325, Irgacure-OXE01, Irgacure-OXE02, and N-1919 and NCI-831 manufactured by BASF JAPAN.

Specific examples of the α-aminoacetophenone-based photopolymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinoacetone-1, 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylbenzene yl)methyl]-1-[4-(4-morphoyl)phenyl]-1-butanone, N,N-dimethylaminoacetophenone, etc., as commercially available products, such as Irgacure-907, Irgacure-369, Irgacure-379, etc. manufactured by BASF JAPAN.

Specific examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6-trimethyl) Benzyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzylyl)-2,4,4-trimethyl-pentylphosphine oxide, etc. can be used as commercial products Such as Irgacure-TPO made by BASF JAPAN, Omnirad 819 made by IGM Resins, etc.

Specific examples of the titanocene-based photopolymerization initiator include bis(cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadienyl)-di-chloro-titanium, and bis(cyclopentadienyl)-di-chloro-titanium. (Cyclopentadienyl)-bis(2,3,4,5,6-pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrole- 1-yl) phenyl) titanium and the like. As a commercial item, Irgacure-784 by BASF JAPAN company etc. is mentioned, for example.

In addition, as the photobase generator, it can be an ionic photobase generator or a non-ionic photobase generator, but the sensitivity of the composition with the ionic photobase generator is high, and it is beneficial to the pattern The formation of the film is better. As a basic substance, a secondary amine and a tertiary amine are mentioned, for example.

As the ionic photobase generator, for example, salts of carboxylic acids containing aromatic components and tertiary amines, or WPBG-082, WPBG-167, WPBG-168, WPBG of ionic PBGs manufactured by Wako Pure Chemical Industries, Ltd. can be used. -266, WPBG-300, etc.

As the nonionic photobase generator, for example, α-aminoacetophenone compounds, oxime ester compounds, or those having N-methylated aromatic amino groups, N-arylated aromatic amino groups, Substituent compounds of nitrobenzyl carbamate, alkoxybenzyl carbamate, etc. As other photobase generators, such as WPBG-018 (trade name: 9-anthrylmethyl N,N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2-hydroxyphenyl)-2-propenyl]piperidine ((E)-1-[3-(2-hydroxyphenyl)-2- propenoyl]piperidine), WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate), WPBG-165 and the like.

(B) The photosensitive agent system may be used individually by 1 type, and may be used in combination of 2 or more types. (B) The compounding quantity of a sensitizer is preferably 0.5-40 mass % on the basis of the total solid content of a composition, and is preferably 1-30 mass %.

[(C) Thiol compound] The (C) thiol compound is not particularly limited, and in addition to D,L-dithiothreitol and 2-mercaptoethanol, the following compounds can also be used Wait. In particular, D,L-dithiothreitol is also preferred in this system.

(C) Thiol compound type may be used individually by 1 type, and may be used in combination of 2 or more types. (C) The compounding amount of the thiol compound is preferably 0.01 to 20 mass %, more preferably 0.1 to 10 mass % based on the total solid content of the composition. By setting the above range, the dross can be suppressed more reliably. produce.

[(D) At least one of urea compound and melamine compound] The photosensitive resin composition of the present invention contains at least one of (D1) urea compound and (D2) melamine compound as component (D). The urea compound and the melamine-based compound may be used alone or in combination.

The (D1) urea compound is not particularly limited, and for example, 1,3-diphenylurea, 1,3-bis[4-(trifluoromethyl)phenyl]urea, N,N'-bis (Trimethylsilyl)urea, 1-Acetyl-3-methylurea, 1-Acetyl-2-thiourea, Acetylurea, 1-adamantylthiourea, 1-allyl -3-(2-hydroxyethyl)-2-thiourea, benzylidene urea, N-benzyl thiourea, benzyl urea, benzyl urea, 1,3-bis(tert-butoxy carbonyl)thiourea, 1,3-bis(4-chlorophenyl)urea, 1,3-bis(4-fluorophenyl)urea, 1,3-(hydroxymethyl)urea, 1,3-bis (4-methoxyphenyl)urea, biurea, butylurea, N,N'-diethyl-N,N'-diphenylurea, etc.

(D1) Urea compound type may be used individually by 1 type, and may be used in combination of 2 or more types. The compounding quantity of the urea compound (D1) is preferably 0.01 to 15% by mass, more preferably 0.05 to 10% by mass, based on the total solid content of the composition. By making the above range, the residual film rate can be improved, the developability of the thick photosensitive film on the metal substrate can be improved, and a better pattern shape can be obtained after developing.

Moreover, as a ratio of (C) thiol compound and (D1) urea compound, it is preferable that (C) thiol compound is equal to or more than (D1) urea compound. In particular, on a mass basis, the ratio of the compounding amount of the (C) thiol compound/(D1) the compounding amount of the urea compound is preferably 1:1 to 10:1, preferably 1:1 to 5:1 . By making the ratio of (C) thiol compound and (D1) urea compound into the said range, the effect of this invention can be acquired more favorably.

The (D2) melamine-based compound is not particularly limited, and examples of commercially available products include Nikalac MW-30HM, Nikalac MW-390, Nikalac MW-100LM, and Nikalac MX-750LM manufactured by Sanwa Chemical Co., Ltd. .

(D2) Melamine-type compound type may be used individually by 1 type, and may be used in combination of 2 or more types. (D2) The compounding quantity of the melamine-based compound is preferably 0.1 to 30 mass %, more preferably 1 to 20 mass %, based on the total solid content of the composition. By setting the above range, the residual film rate can be increased, the developability of the thick photosensitive film on the metal substrate can be improved, and a better pattern shape can be obtained after developing.

Moreover, as a ratio of (C) thiol compound and (D2) melamine type compound, it is preferable that (C) thiol compound is less than (D2) melamine type compound. In particular, on the basis of mass, the ratio of the compounding amount of the (C) thiol compound/(D2) the compounding amount of the melamine-based compound is preferably 0.01:1 to less than 1:1, preferably 0.1:1 to 0.8:1 is better. By making the ratio of (C) thiol compound and (D2) melamine type compound into the said range, the effect of this invention can be acquired more favorably.

A solvent can be compounded in the photosensitive resin composition of this invention. As a solvent, any one of (A) polybenzoxazole precursor, (B) photosensitive agent, (C) thiol compound, (D) urea compound, and melamine-based compound, and any other There is no particular limitation on the additive dissolving agent. Specific examples of the solvent include N,N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N,N'-dimethylethyl Amide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazole Linone, N-cyclohexyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphamide, pyridine, diethylene glycol monomethyl ether. These systems may be used alone, or two or more of them may be used in combination. The amount of the solvent used is in the range of 50 to 9000 parts by mass with respect to 100 parts by mass of the (A) polybenzoxazole precursor according to the thickness or viscosity of the coating film.

Moreover, in the photosensitive resin composition of this invention, by adding a crosslinking agent or a silane coupling agent, the physical property and adhesiveness of a film can be improved, and it is preferable. As a crosslinking agent and a silane coupling agent, a well-known thing can be used suitably, and there is no restriction|limiting in particular.

In addition, the photosensitive resin composition of the present invention may be formulated with a known sensitizer for improving photosensitivity, or a known adhesive agent for improving adhesion to a substrate, within the range that does not impair the effects of the present invention.

Furthermore, in order to provide the photosensitive resin composition of the present invention with processing characteristics and various functionalities, other various organic or inorganic low molecular or high molecular compounds may be blended. For example, surfactants, levelers, plasticizers, microparticles, and the like can be used. The microparticles include organic microparticles such as polystyrene and polytetrafluoroethylene, and inorganic microparticles such as colloidal silica, carbon, and layered silicate. Moreover, various coloring agents, fibers, etc. may be mix|blended with the photosensitive resin composition of this invention.

The photosensitive resin composition of the present invention may be positive type or negative type, and in the case of positive type, it is preferable because a more significant effect can be obtained.

[Dry Film] The dry film system of the present invention has a resin layer obtained by coating the photosensitive resin composition of the present invention and drying it. The dry film of the present invention is used by laminating the resin layer in contact with the base material.

The dry film of the present invention is formed by applying the photosensitive resin composition of the present invention on a carrier film (supporting film) by a blade coater, a lip coater, or a spot coater. The resin layer is formed by uniformly applying and drying by a suitable method such as a comma coater and a film coater, preferably by laminating a cover film (protective film) thereon. The cover film and the carrier film may be the same film material, or different films may be used.

In the dry film of the present invention, the film materials of the carrier film and the cover film can be arbitrarily used as those known for use in dry films.

As the carrier film, for example, a thermoplastic film such as a polyester film such as polyethylene terephthalate having a thickness of 2 to 150 μm can be used.

As the cover film, for example, polyethylene film, polypropylene film, etc. can be used, but the adhesive force with the resin layer is preferably smaller than that of the carrier film.

The film thickness of the resin layer on the dry film of the present invention is preferably 100 μm or less, and preferably in the range of 5 to 50 μm.

Using the photosensitive resin composition of the present invention, the cured product, that is, the pattern film, in the case of, for example, a positive-type photosensitive resin composition, is produced as follows.

First, as step 1, a photosensitive resin composition is applied on a substrate and dried, or a coating film is obtained by transferring (laminating) a resin layer from a dry film onto a substrate. As a method of coating the photosensitive resin composition on the substrate, a method conventionally used for coating the photosensitive resin composition can be used, for example, a spin coater, a bar coater, a blade coating The method of coating by machine, curtain coater, screen printing machine, etc., the method of spray coating by spraying machine, and the ink jet method, etc. As the drying method of the coating film, methods such as air drying, heating drying by an oven or a hot plate, vacuum drying and the like can be used. In addition, drying of the coating film is preferably performed under conditions that do not cause ring closure of the (A) polybenzoxazole precursor in the photosensitive resin composition. Specifically, natural drying, blow drying, or heat drying can be performed under the conditions of 1 to 30 minutes at 70 to 140°C. Preferably, drying is performed on a hot plate for 1 to 20 minutes. In addition, vacuum drying is also possible, and in this case, it can be carried out under the conditions of room temperature for 20 minutes to 1 hour.

The base material is not particularly limited, and can be widely used for semiconductor base materials such as silicon wafers, wiring boards, and base materials made of various resins or metals.

Next, as step 2, the above-mentioned coating film is directly exposed through a photomask with a pattern, or directly. The exposure light used the wavelength which can activate the photoacid generator which is (B) a photosensitizer and generate an acid. Specifically, the exposure light is preferably one whose maximum wavelength is in the range of 350 to 410 nm. When using a suitable sensitizer as described above, the photosensitivity can be adjusted. As the exposure apparatus, for example, a contact aligner, a mirror projection, a stepper, a laser direct exposure apparatus and the like can be used.

Next, as step 3, heating may be performed to partially ring-close the (A) polybenzoxazole precursor in the unexposed portion. Here, the closed loop rate is about 30%. The heating time and the heating temperature can be appropriately changed according to the (A) polybenzoxazole precursor, the coating film thickness, and the type of the photoacid generator as the (B) photosensitizer.

Next, as step 4, the coating film is treated with a developing solution. Thereby, the exposure part in a coating film is removed, and the patterned film of the photosensitive resin composition of this invention can be formed.

As the method used for image development, any method can be selected from conventionally known photoresist image development methods, such as spin spray method, liquid filling method, immersion method with ultrasonic treatment, and the like. Examples of the developer include inorganic bases such as sodium hydroxide, sodium carbonate, sodium silicate, and ammonia, organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine, hydrogen Aqueous solutions of quaternary ammonium salts such as tetramethylammonium oxide and tetrabutylammonium hydroxide. Furthermore, appropriate amounts of water-soluble organic solvents such as methanol, ethanol, and isopropyl alcohol or surfactants may be added to these as necessary. After that, as necessary, the coating film is washed with a rinse solution to obtain a patterned film. As the rinse liquid, for example, distilled water, methanol, ethanol, isopropyl alcohol and the like can be used alone or in combination. Moreover, as a developing solution, the above-mentioned solvent can also be used.

Then, as step 5, the patterned film is heated to obtain a cured coating film (cured product). In this case, the (A) polybenzoxazole precursor may be ring-closed to obtain polybenzoxazole. The heating temperature is appropriately set so that the patterned film of polybenzoxazole can be hardened. For example, heating is performed at 150 to 350° C. for about 5 to 120 minutes in an inert gas. The preferred range of the heating temperature is 200-300°C. Heating is performed by, for example, a hot plate, an oven, an elevated oven with a programmable thermometer. As the atmosphere (gas) at this time, air can be used, and inert gas such as nitrogen and argon can also be used.

Furthermore, when the photosensitive resin composition of the present invention is a negative-type photosensitive resin composition, a photopolymerization initiator or a photobase generator can be used instead of the photoacid generator as the (B) photosensitive agent, and In the above-mentioned step 4, the coating film is treated with a developing solution, and the unexposed portion in the coating film is removed to form a patterned film of the photosensitive resin composition of the present invention.

The use of the photosensitive resin composition of the present invention is not particularly limited, and for example, it can be suitably used as a printing ink or an adhesive, or a material for forming display devices, semiconductor devices, electronic parts, optical parts, or building materials. Specifically, as a material for forming a display device, a color filter, a film for a flexible display, a resist material, an alignment film and the like can be used as a layer forming material or an image forming material. In addition, as a material for forming a semiconductor device, a layer forming material such as a resist material and a buffer coating film can be used. In addition, as a material for forming electronic components, it can be used for a printed wiring board, an interlayer insulating film, a wiring coating film, and the like as a sealing material or a layer forming material. Furthermore, as a material for forming optical parts, as an optical material or a layer forming material, it can be used for a hologram, an optical waveguide, an optical circuit, an optical circuit part, an antireflection film, and the like. Furthermore, as a building material, it can be used for paints, coating agents, and the like.

The photosensitive resin composition of the present invention is mainly used as a pattern-forming material, and the patterned film thus formed functions as a permanent film composed of polybenzoxazole as a component for imparting heat resistance or insulation, Therefore, it can be suitably used as a surface protective film, an interlayer insulating film, an insulating film for rewiring, a protective film for a flip chip device, a protective film for a device having a bump structure, a multilayer insulating film for a semiconductor device, a display device, and a light-emitting device in particular. Interlayer insulating films for circuits, insulating materials for passive parts, protective films for printed wiring boards such as solder resists or cover lay films, and liquid crystal alignment films. [Example]

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited by the following examples. Moreover, the "parts" and "%" referred to below are all quality standards unless otherwise specified.

(Synthesis of polybenzoxazole (PBO) precursor (PHA)) To a 0.5-liter flask equipped with a stirrer and a thermometer, 212 g of N-methylpyrrolidone, bis(3-amino-4-hydroxyamide) were placed 28.00 g (76.5 mmol) of phenyl) hexafluoropropane was dissolved by stirring. Then, the flask was immersed in an ice bath, the inside of the flask was maintained at 0 to 5°C, and 25.00 g (83.2 mmol) of 4,4-diphenyl ether dicarboxylic acid chloride 5 g was added in a solid state over 30 minutes. Stir in an ice bath for 30 minutes. Thereafter, stirring was continued at room temperature for 5 hours. The stirred solution was put into 1 L of ion-exchanged water (specific resistance value: 18.2 MΩ·cm), and the precipitate was recovered. Then, the obtained solid was dissolved in 420 mL of acetone, and put into 1 L of ion-exchanged water. After recovering the precipitated solid, it was dried under reduced pressure to obtain a polybenzoxazole (PBO) precursor (PHA) having the following repeating structure at the carboxyl terminal. The number average molecular weight (Mn) of the polybenzoxazole precursor (PHA) was 12,900, the weight average molecular weight (Mw) was 29,300, and the Mw/Mn was 2.28.

(Examples 1 to 11 and Comparative Examples 1 to 4) To 100 parts by mass of the benzoxazole precursor (PHA), a naphthoquinonediazide compound (DNQ) (TKF-428 manufactured by Sanbao Chemical Co., Ltd.) was blended as a photosensitizer. ) 10 parts by mass, after adding the additives described in Tables 1 and 2 below, N-methylpyrrolidone (NMP) was added so that the benzoxazole precursor became 30% by mass to prepare a varnish, and the examples were prepared 1 to 11. The photosensitive resin compositions of Comparative Examples 1 to 4. For the photosensitive resin compositions of Examples 1 to 11 and Comparative Examples 1 to 4 thus prepared, the pattern shape and resolution were evaluated. The evaluation method is as follows.

(Manufacturing method of dry coating film for evaluation) The above-mentioned photosensitive resin composition was coated on a copper-coated wafer using a spin coater, and dried on a hot plate at 120° C. for 4 minutes to obtain a film thickness after drying of Dry coating film of 10μm photosensitive resin composition.

(Evaluation of Pattern Shape) The obtained dried coating film was irradiated with a broad light of 600 mJ/cm ² through the mask on which the pattern had been engraved using a high-pressure mercury lamp. After exposure, image development was performed for 30 seconds using a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution, and a positive pattern was obtained by rinsing with water. For the obtained positive pattern, the stylus type surface shape measuring device Dektak was used to measure the surface of the positive pattern by linearly moving the sample stage under the diamond stylus and on the precision reference surface. Surface shape and bending. Based on this measurement result, the cross-sectional shape of the obtained positive pattern was evaluated according to the evaluation criteria shown in FIG. 1 . The upper part of Fig. 1 shows the cross-sectional analysis data obtained by Dektak, and the lower part shows a schematic cross-sectional view of the cross-sectional shape of the pattern. A: The case where the upper part of the cross-sectional shape of the pattern is thinned and rounded is rated as ×, B: The case where the coating film of the exposed part is not sufficiently removed at the time of development, and a large amount of dross remains on the metal substrate is rated as × , C: The case where the cross-sectional shape of the pattern is a neat quadrangle/tapered shape is rated as 0.

(Evaluation of resolution) Using an electron microscope (SEM), the pattern shape of the dry coating film (film thickness 10 μm) obtained by the above-mentioned method for producing a dry coating film for evaluation was directly observed, and measured under high exposure The cross-sectional shape of the pattern can be developed in a neat square/tapered shape, and the size (μm) of the line width and line spacing.

These results are combined and shown in the table below. Moreover, the cross-sectional analysis data obtained by Dektak of Example 4 and Comparative Examples 1 and 2 are shown in FIGS. 2-4.

＊3)D,L-二硫蘇糖醇(下述構造式所示之化合物)

＊4)2-巰基乙醇(下述構造式所示之化合物)

＊5)1,3-二苯基脲(下述構造式所示之化合物)

＊6)三聚氰胺系化合物(股份有限公司三和化學製)*1) Naphthoquinone diazide compound (TKF-428 manufactured by Sanbo Chemical Co., Ltd.) *2) TML (compound represented by the following structural formula)

*3) D,L-Dithiothreitol (a compound represented by the following structural formula)

*4) 2-Mercaptoethanol (a compound represented by the following structural formula)

*5) 1,3-Diphenylurea (a compound represented by the following structural formula)

*6) Melamine-based compounds (manufactured by Sanwa Chemical Co., Ltd.)

As shown in the above table and figures, in Comparative Examples 1 and 3, which contained the thiol compound but not the urea compound or the melamine-based compound, although high resolution was obtained, the residual film ratio was poor and the pattern shape became rounded. . In addition, in Comparative Examples 2 and 4 containing the urea compound or the melamine-based compound but not containing the thiol compound, the developability and the residual film ratio were poor, the pattern shape became round, and a large amount of residue remained. On the other hand, in each Example, the residual film rate was high, and the pattern shape was also a cross-sectional quadrangular shape, and high resolution was obtained even with a thick photosensitive film with a film thickness of 10 μm. Moreover, from the comparison between Example 2 and Example 6, and Example 8 and Example 11, it can be seen that the resolution can be improved by adding a crosslinking agent.

[FIG. 1] An explanatory diagram of the evaluation method of the pattern shape in the Example. [Fig. 2] Sectional analysis data obtained by the stylus-type surface shape measuring device Dektak (manufactured by Bruker, stylus-type analysis system, hereinafter also referred to as "Dektak") in Example 4. [Figure 3] Cross-sectional analysis data obtained by Dektak in Comparative Example 1. [Figure 4] Cross-sectional analysis data obtained by Dektak in Comparative Example 2.

Claims (5)

A photosensitive resin composition is characterized by containing: (A) polybenzoxazole precursor, (B) photosensitizer, (C) thiol compound, and (D) at least any urea compound and melamine compound A; however, does not contain 2-mercaptobenzoxazole or its derivatives. A dry film characterized by having a resin layer obtained by coating and drying the photosensitive resin composition of claim 1 on the film. A cured product characterized by being composed of the photosensitive resin composition of claim 1 or the resin layer of the dry film of claim 2. A printed wiring board characterized by having the hardened material as claimed in claim 3. A semiconductor element characterized by having the cured product as claimed in claim 3.

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