JP7329344B2 - Photosensitive resin composition, dry film, cured product, and electronic component - Google Patents

Description

TECHNICAL FIELD The present invention relates to photosensitive resin compositions, dry films, cured products, and electronic parts.

Buffer coat films for semiconductor devices such as LSI and insulating films for rewiring in wafer level packages (WLP) are made of photosensitive materials containing precursors of photosensitive heat-resistant resins such as photosensitive polyimide and polybenzoxazole (PBO). Resin compositions are widely used.

When a photosensitive resin composition is used as an insulating film for WLP, the cured product of the photosensitive resin composition has translucency, so highly confidential circuit information on the wafer surface may be visible. There is a risk that this circuit information will be leaked to an outsider.
On the other hand, when the amount of the coloring pigment in the photosensitive resin composition is increased in order to hide highly confidential circuit information, the light transmittance of the insulating film deteriorates, and the photosensitive resin composition deep in the insulating film deteriorates. It may cause poor photosensitivity.
Therefore, there is a demand for a colored photosensitive resin composition with excellent photosensitivity that reliably conceals highly confidential circuit information and does not cause defects during production.

In addition, when the photosensitive resin composition is used as an insulating film for WLP, strain occurs due to curing shrinkage of the photosensitive resin composition when the photosensitive resin composition is cured, that is, internal stress remains. I have something to do. This internal stress manifests itself as warping of the silicon wafer when the thickness of the silicon wafer is reduced in the back surface grinding process, which is a post-process. As a result, it causes defective transportation during the grinding process and defective mounting in the subsequent dicing process. Therefore, when the photosensitive resin composition is used as an insulating film for WLP, it is required that the internal stress after curing is extremely low.

In response to such demands, conventionally, as a colored photosensitive resin composition, in Patent Document 1, an alkali-soluble heat-resistant resin, a photosensitive agent, and at least one coloring agent selected from dyes, inorganic pigments, and organic pigments are added. A photosensitive resin composition has been proposed.

Japanese Patent Application Laid-Open No. 2004-145320

According to the invention described in Patent Document 1, it is considered that sufficient performance is exhibited with respect to concealment of circuit information. However, there is a possibility that the insulating properties may be insufficient due to the extensive use of carbon black. Also, evaluation of internal stress after curing is not included.

Therefore, the object of the present invention is that the photosensitive resin composition after curing can be photosensitized without causing poor photosensitivity ((deep) photosensitivity is excellent), and it can be used as an insulating film for rewiring of WLP. Provided are a photosensitive resin composition, a dry film, a cured product, and an electronic component, which has a hiding property to such an extent that a wiring circuit pattern on a silicon wafer cannot be visually recognized when used, and which has extremely little internal stress during curing shrinkage. That's what it is.

The inventors of the present invention have made intensive studies to achieve the above object, and found that a photosensitive resin composition containing a polybenzoxazole precursor has a benzoxazole structure through a ring closure reaction of the polybenzoxazole precursor by heating. It is thought that internal stress is generated in the cured product due to the intermolecular packing effect that occurs during formation. Therefore, the inventors have found that the internal stress of the cured product can be alleviated by adding a specific amount of organic pigment so as to suppress the packing effect, and have completed the present invention.

Condensed polycyclic pigments, typified by phthalocyanine and perylene, have traditionally had a strong stacking effect between molecules due to the π-electron interaction of the conjugated system, resulting in durability as a pigment. known to be Such pigments are presumed to have a high affinity with aromatic polymers such as polybenzoxazole. (Intermolecular interaction) is reduced, shrinkage of the cured film, and eventually internal stress is reduced.

That is, the present invention
(A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) an organic pigment,
The amount of the (C) organic pigment is 0.1 to 30 parts by mass when the amount of the (A) polybenzoxazole precursor is 100 parts by mass. A photosensitive resin. A composition is provided.

The photosensitive resin composition of the present invention may be the photosensitive resin composition characterized by not containing carbon black.

In the photosensitive resin composition of the present invention, the (C) organic pigment may contain at least one of a perylene-based pigment and a phthalocyanine-based pigment.

The present invention also provides a dry film, comprising a resin layer obtained by applying the photosensitive resin composition to a film and drying the film.

The present invention also provides a cured product obtained by curing the photosensitive resin composition or the resin layer of the dry film.

The present invention also provides an electronic component comprising the cured product.

According to the present invention, it can be exposed to light without causing poor photosensitivity (excellent (deep) photosensitivity), and has a concealing property to the extent that the wiring circuit pattern on the silicon wafer cannot be visually recognized, and during curing shrinkage It is possible to provide a photosensitive resin composition with extremely low internal stress, a dry film, a cured product, and an electronic component.

In addition, when isomers exist in the described compounds, all possible isomers can be used in the present invention unless otherwise specified.

1. Photosensitive resin composition The photosensitive resin composition of the present invention contains a polybenzoxazole precursor (A), a photosensitive agent (B), and an organic pigment (C), and the amount of the organic pigment is The photosensitive resin composition is characterized by containing 0.1 to 30 parts by mass of the components per 100 parts by mass.
The photosensitive resin composition of the present invention is described in detail below.

1-1. (A) Polybenzoxazole precursor The photosensitive resin composition of the present invention contains a polybenzoxazole precursor.
The method for synthesizing this polybenzoxazole precursor is not particularly limited, and it can be synthesized by a known method. For example, it can be obtained by reacting a dihydroxydiamine as an amine component with a dihalide of a dicarboxylic acid such as a dicarboxylic acid dichloride as an acid component.

（式中、Ｘは４価の有機基を示し、Ｙは２価の有機基を示す。ｎは１以上の整数であり、好ましくは１０～５０、より好ましくは２０～４０である。） The polybenzoxazole precursor is preferably a polyhydroxyamic acid having a repeating structure represented by the following formula (1).

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

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

Examples of the dihydroxydiamines include 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)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, 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-hexa fluoropropane and the like. Among them, 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane is preferred.

Examples of the dicarboxylic acid include isophthalic acid, terephthalic acid, 5-tert-butylisophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′. -dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis(4-carboxyphenyl)sulfone, 2,2-bis(p-carboxyphenyl)propane, 2,2 -Dicarboxylic acids having aromatic rings such as bis(4-carboxyphenyl)-1,1,1,3,3,3-hexafluoropropane, oxalic acid, malonic acid, succinic acid, 1,2-cyclobutanedicarboxylic acid, Aliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid and 1,3-cyclopentanedicarboxylic acid are included. Among them, 4,4'-dicarboxydiphenyl ether is preferred.

In the general formula (1), the tetravalent organic group represented by X may be an aliphatic group or an aromatic group, but is preferably an aromatic group, and two hydroxy groups and two amino groups are at the ortho positions. Positioning on an aromatic ring is more preferred. The tetravalent aromatic group preferably has 6 to 30 carbon atoms, more preferably 6 to 24 carbon atoms. Specific examples of the tetravalent aromatic group include, but are not limited to, the following functional groups, and a known aromatic group that can be contained in the polybenzoxazole precursor is selected depending on the application. can do.

Among the aromatic groups, the tetravalent aromatic group is preferably the following group.

In the general formula (1), the divalent organic group represented by Y may be an aliphatic group or an aromatic group, but is preferably an aromatic group, and the carbonyl in the general formula (1) on the aromatic ring It is more preferable that the The divalent aromatic group preferably has 6 to 30 carbon atoms, more preferably 6 to 24 carbon atoms. Specific examples of the divalent aromatic group include, but are not limited to, the following groups, and any known aromatic group contained in the polybenzoxazole precursor may be selected depending on the application. good.

（式中、Ａは単結合、－ＣＨ_２－、－Ｏ－、－ＣＯ－、－Ｓ－、－ＳＯ_２－、－ＮＨＣＯ－、－Ｃ（ＣＦ_３）_２－、－Ｃ（ＣＨ_３）_２－からなる群から選択される２価の基を表す。）

(wherein A is a single bond, -CH ₂ -, -O-, -CO-, -S-, -SO ₂ -, -NHCO-, -C(CF ₃ ) ₂ -, -C(CH ₃ ) ₂ represents a divalent group selected from the group consisting of -.)

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

The polybenzoxazole precursor can contain two or more repeating structures of the above polyhydroxyamic acid. Moreover, it may contain a structure other than the repeating structure of the polyhydroxyamic acid described above, and may contain, for example, a repeating structure of polyamic acid.

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

One of the polybenzoxazole precursors described above may be used alone, or two or more thereof may be used in combination.
The amount of the polybenzoxazole precursor to be blended is preferably 30 to 95% by mass, more preferably 50 to 90% by mass, based on the total solid content of the composition.

1-2. (B) Photosensitizer The photosensitive resin composition of the present invention contains a photosensitizer.
The photosensitive agent is not particularly limited, and a photoacid generator, a photopolymerization initiator, or a photobase generator can be used. A photoacid generator is a compound that generates an acid upon irradiation with light such as ultraviolet light or visible light. A photopolymerization initiator is a compound that generates radicals or the like upon irradiation with similar light. It is a compound that changes its molecular structure or generates one or more basic substances by cleaving the molecule when exposed to light. In particular, in the present invention, a photoacid generator can be preferably used as the photosensitizer.

Photoacid generators include naphthoquinonediazide compounds, diarylsulfonium salts, triarylsulfonium salts, dialkylphenacylsulfonium salts, diaryliodonium salts, aryldiazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters. , aromatic N-oxyimide sulfonates, aromatic sulfamides, benzoquinonediazosulfonic acid esters, and the like. Preferably, the photoacid generator is a dissolution inhibitor. Among them, a naphthoquinone diazide compound is preferable.

Specific examples of the naphthoquinonediazide compound include tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene naphthoquinonediazide adducts (for example, TS533, TS567, TS583, TS593 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.). ), naphthoquinonediazide adducts of tetrahydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.), and 4-{4-[1,1-bis(4-hydroxyphenyl)ethyl]-α ,α-dimethylbenzyl}phenol naphthoquinonediazide adducts (eg, TKF-428 and TKF-528 manufactured by Sambo Kagaku Kenkyusho Co., Ltd.) and the like can be used.

Further, as the photopolymerization initiator, commonly known ones can be used. An initiator, a titanocene-based photopolymerization initiator, or the like can be used.

Examples of the oxime ester photopolymerization initiator include commercially available products such as CGI-325, Irgacure OXE01 and Irgacure OXE02 manufactured by BASF Japan, N-1919 and NCI-831 manufactured by ADEKA.

Specific examples of the α-aminoacetophenone-based photopolymerization initiator include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1,2-benzyl-2-dimethylamino- 1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone .

Specific examples of the acylphosphine oxide-based photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6 -Dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, etc., and commercially available products include Irgacure TPO manufactured by BASF Japan, Omnirad 819 manufactured by IGM Resins, and the like. can.

Specific examples of the titanocene-based photopolymerization initiator include bis(cyclopentadienyl)-di-phenyl-titanium, bis(cyclopentadienyl)-di-chloro-titanium, bis(cyclopentadienyl) -bis(2,3,4,5,6 pentafluorophenyl)titanium, bis(cyclopentadienyl)-bis(2,6-difluoro-3-(pyrrol-1-yl)phenyl)titanium, etc. . Commercially available products include Irgacure 784 manufactured by BASF Japan.

The photobase generator may be either an ionic photobase generator or a non-ionic photobase generator. It is advantageous, so it is preferable. Basic substances include, for example, secondary amines and tertiary amines.

Examples of ionic photobase generators include salts of aromatic component-containing carboxylic acids and tertiary amines, and ionic PBGs WPBG-082, WPBG-167, WPBG-168 and WPBG- manufactured by Wako Pure Chemical Industries, Ltd. 266, WPBG-300, etc. can be used.

Examples of nonionic photobase generators include α-aminoacetophenone compounds, oxime ester compounds, N-formylated aromatic amino groups, N-acylated aromatic amino groups, nitrobenzylcarbamate groups, and alkoxybenzyls. A compound having a substituent such as a carbamate group is included. Other photobase generators include WPBG-018 (trade name: 9-anthrylmethyl N,N'-diethylcarbamate), WPBG-027 (trade name: (E)-1-[3-(2-hydroxyphenyl)-2- propenoyl]piperidine), WPBG-140 (trade name: 1-(anthraquinon-2-yl)ethyl imidazolecarboxylate), WPBG-165 and the like can also be used.

The photosensitizers described above may be used singly or in combination of two or more.
The amount of the photosensitive agent to be blended is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, based on the total solid content of the composition.

1-3. (C) Organic Pigment The photosensitive resin composition of the present invention contains an organic pigment. The organic pigment is not particularly limited, and may include any of known and commonly used pigments such as azo pigments, phthalocyanine pigments, and condensed polycyclic pigments.

Examples of azo pigments include soluble azo pigments such as azo yellow lake and azo lake red; insoluble azo pigments such as monoazo yellow, monoazo orange, disazo pigments and pyrazolone pigments; benzimidazolone pigments; β naphthol pigments; a condensed azo pigment; and the like.

Phthalocyanine pigments include phthalocyanine blue and phthalocyanine phosphorus.

Condensed polycyclic pigments include threne pigments (anthraquinone pigments) such as anthrapyrimidine yellow, flavanthrone yellow, anthanthrone orange, dianthraquinonyl red, and indanthrone blue, indigo blue, thioindigo magenta, and thioindigo. Indigo pigments such as Bordeaux, Perinone pigments such as Perinone Orange and Perinone Red, Perylene pigments such as Perylene Permillion, Perylene Red BL, Perylene Magenta, Perylene Red and Perylene Violet, Phthalone pigments such as Quinophthalone Yellow, Carbesol Violet , dioxazine-based pigments such as , quinacridone-based pigments such as quinacridone magenta, quinacridone scar red, and dichloroquinathalidone magenta, isoindolinone-based pigments such as isoindolinone yellow and soindolinone orange, isoindoline, metal complex pigments; can be done.

The above organic pigments may be used alone or in combination. Among these, it can be exposed to light without causing poor photosensitivity (excellent (deep) photosensitivity), and when used as an insulating film for rewiring of WLP, the wiring circuit pattern on the silicon wafer can be visually recognized. From the viewpoint of obtaining a photosensitive resin composition that has a hiding power to the extent that it cannot be hidden and has extremely little internal stress during curing shrinkage, it preferably contains a polycyclic pigment, and more preferably contains a phthalocyanine-based or perylene-based pigment. It is further preferred to include both the system and the perylene system.

Condensed polycyclic pigments typified by phthalocyanine and perylene are known to have strong intermolecular stacking effect due to π-electron interactions in conjugated systems and to obtain resistance as pigments. Such pigments are presumed to have a high affinity with aromatic polymers such as polybenzoxazole. (Intermolecular interaction) is reduced, shrinkage of the cured film, and eventually internal stress is reduced.

The blending amount of such an organic pigment is 0.1 to 30 parts by mass, preferably 0.5 to 25 parts by mass, and 1 to 25 parts by mass when the blending amount of the polybenzoxazole precursor is 100 parts by mass. Part by weight is more preferred, and 5 to 25 parts by weight is even more preferred. In addition, this compounding amount is good also as 15 mass % or less. When the blending amount of the organic pigment is within such a range, the wiring circuit pattern on the wafer can be formed when it is used as an insulating film for rewiring of WLP, and can be exposed to light without causing poor exposure. It is possible to obtain a photosensitive resin composition that has concealability to the extent that it cannot be visually recognized and that has extremely little internal stress during curing shrinkage.

1-4. Other Components The photosensitive resin composition of the present invention may further contain other components. Other components that can be added include, for example, solvents, cross-linking agents, silane coupling agents, sensitizers, adhesion aids, surfactants, leveling agents, plasticizers, and fine particles.

The solvent is not particularly limited as long as it dissolves at least one of the polybenzoxazole precursor, the photosensitizer and the organic pigment, and other optional additives. Specific examples of solvents include N,N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N,N'-dimethylacetamide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl -γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethylsulfoxide, hexamethylphosphoramide, pyridine, diethylene glycol monomethyl ether. These may be used alone or in combination of two or more. The amount of the solvent used can be in the range of 50 to 9000 parts by weight with respect to 100 parts by weight of the polybenzoxazole precursor, depending on the coating film thickness and viscosity.

In addition, the photosensitive resin composition of the present invention can improve physical properties and adhesion of the film by adding a crosslinking agent or a silane coupling agent. As the cross-linking agent and the silane coupling agent, known ones can be appropriately selected and used, and they are not particularly limited.

Further, the photosensitive resin composition of the present invention may contain a known sensitizer for improving photosensitivity and a known adhesion promoter for improving adhesion to a substrate within a range that does not impair the effects of the present invention. Agents and the like can also be blended.

Furthermore, various organic or inorganic low-molecular-weight or high-molecular-weight compounds may be added to the photosensitive resin composition of the present invention in order to impart processing properties and various functionalities. For example, surfactants, leveling agents, plasticizers, fine particles and the like can be used. Fine particles include organic fine particles such as polystyrene and polytetrafluoroethylene, and inorganic fine particles such as colloidal silica, carbon, and layered silicate. Furthermore, the photosensitive resin composition of the present invention may contain inorganic pigments such as carbon black and titanium oxide, fibers, and the like. When an inorganic pigment is combined with the photosensitive resin composition of the present invention, for example, carbon black, which is an inorganic pigment, has electrical conductivity. Furthermore, since the absorption wavelength region overlaps with that of the above-described photosensitizer and lowers the photosensitivity of the photosensitive resin composition, it is preferably not included.

The photosensitive resin composition of the present invention may be of a positive type or a negative type, but the positive type is preferable because more remarkable effects can be obtained.

[Dry film]
The dry film of the present invention has a resin layer obtained by drying after applying the photosensitive resin composition of the present invention. The dry film of the present invention is used by laminating a resin layer so as to be in contact with a substrate.

The dry film of the present invention is prepared by uniformly applying the photosensitive resin composition of the present invention to a carrier film (support film) by an appropriate method such as a blade coater, a lip coater, a comma coater, a film coater, and drying. It can be produced by forming a coated resin layer and preferably laminating a cover film (protective film) thereon. The cover film and the carrier film may be made of the same film material or different films.

In the dry film of the present invention, the film materials of the carrier film and the cover film can be any known materials used for 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 is used.

As the cover film, a polyethylene film, a polypropylene film, or the like can be used.

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

2. Method for Producing Cured Product of Photosensitive Resin Composition Using the photosensitive resin composition of the present invention, a pattern film, which is a cured product thereof, is produced as follows, for example, in the case of a positive photosensitive resin composition. .

First, in step 1, a coating film is obtained by applying a photosensitive resin composition onto a substrate and drying it, or by transferring (laminating) a resin layer from a dry film onto the substrate. The method for applying the photosensitive resin composition onto the substrate includes methods conventionally used for applying photosensitive resin compositions, such as spin coaters, bar coaters, blade coaters, curtain coaters, screen printers, and the like. a method of applying with a spray coater, a method of spraying with a spray coater, an inkjet method, or the like.

As a method for drying the coating film, methods such as air drying, heat drying using an oven or a hot plate, and vacuum drying are used. Moreover, it is desirable to dry the coating film under conditions that do not cause ring closure of the (A) polybenzoxazole precursor in the photosensitive resin composition. Specifically, natural drying, air drying, or heat drying can be performed at 70 to 140° C. for 1 to 30 minutes. Drying is preferably carried out on a hot plate for 1-20 minutes. Vacuum drying is also possible, and in this case, it can be carried out at room temperature for 20 minutes to 1 hour.

The substrate is not particularly limited, and can be widely applied to semiconductor substrates such as silicon wafers, wiring substrates, and substrates made of various resins, metals, and the like.

Next, as step 2, the coating film is exposed through a photomask having a pattern or directly. The exposure light has a wavelength capable of activating a photoacid generator as a photosensitive agent to generate an acid, for example. More specifically, the exposure light preferably has a maximum wavelength in the range of 350 to 410 nm. As described above, photosensitivity can be adjusted by using a suitable sensitizer. As an exposure device, a contact aligner, mirror projection, stepper, laser direct exposure device, or the like can be used.

Subsequently, as step 3, heating may be performed to partially ring-close the unexposed portion of the polybenzoxazole precursor. Here, the ring closure rate is about 30%. The heating time and heating temperature are appropriately changed depending on the polybenzoxazole precursor, coating film thickness, and type of photoacid generator as a photosensitive agent.

Then, as step 4, the coating film is treated with a developer. As a result, the exposed portions in the coating film can be removed to form a pattern film of the photosensitive resin composition of the present invention.

As a method used for development, any method can be selected from conventionally known photoresist development methods, such as a rotary spray method, a paddle method, an immersion method accompanied by ultrasonic treatment, and the like. Examples of the developer include inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine and triethanolamine; tetramethylammonium hydroxide and tetrabutylammonium hydroxide. and aqueous solutions of quaternary ammonium salts such as If necessary, a suitable amount of a water-soluble organic solvent such as methanol, ethanol or isopropyl alcohol or a surfactant may be added. After that, the coating film is washed with a rinsing liquid as necessary to obtain a pattern film. Distilled water, methanol, ethanol, isopropyl alcohol, or the like can be used alone or in combination as the rinsing liquid. Moreover, you may use the said solvent as a developer.

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

When the photosensitive resin composition of the present invention is a negative photosensitive resin composition, a photopolymerization initiator or a photobase generator is used as the photosensitive agent in place of the photoacid generator in step 4 above. A patterned film of the photosensitive resin composition of the present invention can be formed by treating the film with a developer to remove the unexposed portions in the coating film.

3. Use of photosensitive resin composition The use of the photosensitive resin composition of the present invention is not particularly limited, and examples thereof include printing inks, adhesives, display devices, semiconductor devices, electronic parts, optical parts, and building materials. It is preferably used as a forming material. Specifically, as a material for forming a display device, it can be used as a layer-forming material or an image-forming material, such as a color filter, a flexible display film, a resist material, an alignment film, or the like.

In addition, as a material for forming a semiconductor device, it can be used as a resist material, a layer forming material such as a buffer coat film, and the like.

Furthermore, as a material for forming electronic parts, it can be used as a sealing material or a layer forming material for a printed wiring board, an interlayer insulating film, a wiring coating film, and the like.

Furthermore, as a material for forming optical parts, it can be used as an optical material or a layer forming material for holograms, optical waveguides, optical circuits, optical circuit parts, antireflection films, and the like.

Furthermore, as building materials, 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 pattern film formed by it functions as a component that imparts heat resistance and insulation as a permanent film made of polybenzoxazole. In particular, surface protective films for semiconductor devices, display devices and light emitting devices, interlayer insulating films, insulating films for rewiring, protective films for flip chip devices, protective films for devices having a bump structure, interlayer insulating films for multilayer circuits, passive It can be suitably used as an insulating material for parts, protective films for printed wiring boards such as solder resists and coverlay films, liquid crystal alignment films, and the like.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. In the following description, "parts" and "%" are based on mass unless otherwise specified.

(Synthesis of polybenzoxazole precursor)
2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3 was placed in a four-necked separable flask equipped with a thermometer, a stirrer, a raw material inlet and a nitrogen gas inlet. After dissolving 40.3 g (0.11 mol) of hexafluoropropane in 1500 g of N-methyl-2-pyrrolidone, 35.4 g (0.12 mol) of diphenyl ether-4,4'-dicarboxylic acid dichloride was added to the reaction system. It was added dropwise while cooling the temperature to 0-5°C.

After completion of dropping, the temperature of the reaction system was returned to room temperature, and the mixture was stirred for 6 hours. After that, 1.8 g (0.1 mol) of pure water was added, and the reaction was further carried out at 40° C. for 1 hour. After completion of the reaction, the reaction solution was added dropwise to 2000 g of pure water. The precipitate was collected by filtration, washed, and vacuum-dried to obtain an alkali-soluble polyhydroxyamide, which is a polybenzoxazole precursor having a repeating structure shown below. The weight average molecular weight was 32,000, the number average molecular weight was 12,500, and the PDI was 2.56.

(Production of photosensitive resin compositions of Examples 1-5 and Comparative Examples 1-2)
To 100 parts by mass of the benzoxazole precursor (PHA), 10 parts by mass of a naphthoquinonediazide compound (DNQ) (TKF-428 manufactured by Sambo Kagaku Co., Ltd.) as a photosensitizer and an organic pigment shown in Table 1 below were blended. After that, γ-butyrolactone was added so that the non-volatile component of the varnish became 30% by mass to obtain the varnish of the photosensitive resin composition of each example and comparative example.

(Preparation of sample substrate for evaluation of visibility (concealment) property)
The obtained varnishes of Examples 1 to 5 and Comparative Examples 1 and 2 were coated on a glass substrate using a spin coater and dried on a hot plate at 110° C. for 3 minutes to obtain a coating film having a thickness of about 5 μm. . Next, using an oven, the coated glass substrate was heated at 150° C./30 minutes and 320° C./60 minutes to obtain test substrates for evaluating hiding properties.

・Visibility (Hiding) Evaluation A PET film printed with various line-and-space test patterns was placed under the above-mentioned test piece for evaluating hiding properties, and observed with the naked eye to evaluate the visibility of the test pattern on the silicon wafer. did. Evaluation was performed according to the following evaluation criteria.
A: All test patterns cannot be visually recognized.
◯: Lines and spaces of test patterns of 150/150 or less cannot be visually recognized.
Δ: Lines and spaces of the test pattern exceeding 150/150 and 300/300 or less cannot be visually recognized.
x: All test patterns can be visually recognized.

(Preparation of sample substrate for internal stress evaluation)
The obtained varnishes of Examples 1 to 5 and Comparative Examples 1 and 2 were coated on a silicon wafer using a spin coater and dried on a hot plate at 110° C. for 3 minutes to obtain a coating film having a thickness of about 5 μm. . Next, using an oven, the coated silicon wafer was heated at 150° C./30 minutes and 320° C./60 minutes to obtain test substrates for internal stress evaluation.

なお、シリコンウエハのヤング率は１９０ＧＰａ、ポアソン比は０．２７とした。
内部応力の評価は下記評価基準にて行った。
◎：内部応力が１５ＭＰａ以下
〇：内部応力が１５ＭＰａ超～２０ＭＰａ以下
△：内部応力が２０ＭＰａ超～３０ＭＰａ以下
×：内部応力が３０ＭＰａ超 · Internal stress evaluation The thickness of the silicon wafer is measured with a micrometer, the film thickness of the resin composition before and after the heating is measured with a stylus surface profiler (DektakXT manufactured by BRUKER Japan), and the radius of curvature is measured as surface roughness. The internal stress was calculated from the change in the amount of warpage between the bare silicon wafer and the coated silicon wafer measured with a thickness measuring machine (SE700, manufactured by Kosaka Laboratory Ltd.) and using the following formula.

The Young's modulus of the silicon wafer was 190 GPa, and the Poisson's ratio was 0.27.
Evaluation of internal stress was performed according to the following evaluation criteria.
◎: Internal stress is 15 MPa or less ○: Internal stress is over 15 MPa to 20 MPa or less △: Internal stress is over 20 MPa to 30 MPa or less ×: Internal stress is over 30 MPa

感光剤：ＴＫＦ-４２８(三宝化学社製)
ペリレンレッド：ＰＡＬＩＯＧＥＮ ＲＥＤ Ｋ３５８０（ＢＡＳＦ社製）
フタロシアニンブルー：ＦＡＳＴＯＧＥＮ ＢＬＵＥ ５３８０/ＦＡ５３８０（ＤＩＣ社製）
チタンブラック：ＵＢ－１(三菱マテリアル社製)
カーボンブラック：ブラックＳＤ－ＴＴ２２５９(レシノカラー工業社製)

Photosensitive agent: TKF-428 (manufactured by Sambo Kagaku Co., Ltd.)
Perylene red: PALIOGEN RED K3580 (manufactured by BASF)
Phthalocyanine blue: FASTOGEN BLUE 5380/FA5380 (manufactured by DIC)
Titanium black: UB-1 (manufactured by Mitsubishi Materials Corporation)
Carbon black: Black SD-TT2259 (manufactured by Resino Color Industry Co., Ltd.)

From the above results, the effects of the present invention can be understood.

Claims (5)

(A) a polybenzoxazole precursor, (B) a photosensitizer, and (C) an organic pigment,
The (C) organic pigment contains both a perylene-based pigment and a phthalocyanine-based pigment ,
The perylene-based pigment is selected from perylene orange, perinone red, perylene permillion, perylene magenta, and perylene violet,
The phthalocyanine pigment is selected from phthalocyanine blue and phthalocyanine green,
The photosensitive resin composition, wherein the blending amount of the (C) organic pigment is 5 to 25 parts by mass when the blending amount of the (A) polybenzoxazole precursor is 100 parts by mass. . 2. The photosensitive resin composition according to claim 1, which does not contain carbon black. A dry film comprising a resin layer obtained by applying the photosensitive resin composition according to claim 1 to a film and drying the composition. A cured product obtained by curing the photosensitive resin composition according to claim 1 or 2 or the resin layer of the dry film according to claim 3. An electronic component comprising the cured product according to claim 4 .