JP5079310B2 - PHOTO TOOL FOR SOLDER RESIST EXPOSURE AND METHOD FOR FORMING SOLDER RESIST PATTERN EXPOSED BY USING THE SAME - Google Patents

Description

  The present invention relates to an exposure processing technique at the time of forming a solder resist pattern on a printed wiring board, and in particular, a solder resist exposure photo tool, a method for forming a solder resist pattern exposed using the photo tool, and the same The present invention relates to a suitable photosensitive composition.

  A solder resist layer is formed on the outermost layer of the printed wiring board. Conventionally, a solder resist layer is obtained by applying a photosensitive composition paste to a substrate on which a wiring circuit is formed, exposing through a photomask in accordance with a predetermined pattern, developing, and curing the irradiated portion of the exposure light. It is formed by the process. In the exposure process at the time of manufacturing a printed wiring board, a thin film is laminated on the resist surface side of the photomask for the purpose of protecting the expensive photomask from scratches and sticking to the resist. In general, as such a protective film, a thermoplastic film such as a PET film capable of transmitting 90% or more of light in the ultraviolet region of 300 nm or more is often used so that the photosensitive composition can be irradiated with a sufficient amount of ultraviolet rays. (For example, refer to Patent Document 1).

  However, when a protective mask made of PET material is used, there is a problem that it is easily affected by moisture absorption and inferior in dimensional stability, and in addition, a printed wiring board that requires thick film (about 100 μm) curing in a coloring system In the solder resist for use, since a pigment such as phthalocyanine blue having a large absorption in the ultraviolet region of 300 to 400 nm is used, the light of 300 to 400 nm transmitted through the photomask does not contribute effectively, and the fine line or thickness The film was prone to halation and undercut, and there was a problem in resolution.

In addition, the circuit thickness of the substrate on which the circuit is formed as the substrate to be processed is greatly different from 25 μm to 105 μm, and the film thickness of the resist is greatly different depending on the place. Therefore, it is difficult to obtain a similar resist shape with the same resist. To cope with this, when the circuit thickness is high at the production site, an exposure amount higher than usual was irradiated to obtain a deeper curing depth. In such a case, the surface layer portion was halated or the line width was increased. However, there arises a problem that a large number of problems occur such that the thickness becomes larger than the design value or the via diameter becomes smaller than the design value. On the other hand, if the exposure amount is low, a sufficient depth of curing cannot be obtained, causing a problem that undercut occurs. Therefore, there is a need for a technique that enables a thick film and high-definition pattern formation as a resist pattern used for a printed wiring board.
Japanese Patent Laid-Open No. 9-230580

  SUMMARY OF THE INVENTION An object of the present invention is to provide a solder resist exposure processing phototool that can form a high-resolution resist pattern with high reproducibility regardless of the film thickness of a solder resist layer and the influence of a blue pigment. Another object of the present invention is to provide a method for forming a solder resist pattern that is exposed using the phototool, and a photosensitive composition suitable for the method.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors pay attention to polyethylene naphthalate that cannot be applied as a protective film to be applied to a solder resist photomask because it does not transmit ultraviolet light of 380 nm or less. In addition, the present invention has developed a solder resist exposure processing technique relating to the present invention, that is, a solder resist exposure photo tool, a resist pattern forming method using the photo tool, and a photosensitive composition suitable for the forming method.

That is, according to the present invention, in a photo tool that is used for an exposure process in forming a solder resist pattern and includes a photomask, light of 370 nm or less is cut by 50% or more on the resist surface side of the photomask and light of 400 nm or more. There is provided a phototool comprising a protective film that transmits 80% or more.

  In one embodiment of the present invention, the protective film may be a thermoplastic film (for example, a polyethylene naphthalate film), and in this case, the thermoplastic film may contain an ultraviolet absorber. Alternatively, the protective film may have an ultraviolet absorbing layer.

  Further, according to the present invention, after an alkali-developable photosensitive composition is applied on a substrate, the coating film is selectively irradiated with ultraviolet rays through the phototool, and an unexposed portion is developed to form a pattern. There is provided a method for forming a solder resist pattern, which is obtained by heat curing by heating to obtain a cured coating film.

Further, the present invention, the alkali-developable photosensitive composition coated on off Irumu, a dry film formed by dry lamination onto a substrate, the obtained coating film, selectively through the phototool There is provided a method for forming a solder resist pattern, characterized by irradiating ultraviolet rays, developing an unexposed portion to form a pattern, and then thermally curing by heating to obtain a cured coating film.

  In one embodiment of the present invention, the photosensitive composition may be a photosensitive composition having an absorbance at a wavelength of 405 nm of a dry coating film of the photosensitive composition of 0.2 to 1.2 per 25 μm thickness.

  Further, the photosensitive composition includes an oxime ester photopolymerization initiator containing a structural portion represented by the following general formula (I), and an α-aminoacetophenone containing a structural portion represented by the general formula (II). Selected from the group consisting of a system photopolymerization initiator, an acylphosphine oxide photopolymerization initiator containing a structural moiety represented by general formula (III), and a titanocene photopolymerization initiator represented by general formula (IV). 1 type, or 2 or more types of photoinitiators may be contained.

  Furthermore, the oxime ester photopolymerization initiator containing the structural moiety represented by the above general formula (I) is a compound represented by the following formula (I-1), or a general formula (I-2) The compound represented by these may be sufficient.

  The photosensitive composition may contain at least one selected from diethylthioxanthone, diethylaminobenzophenone and coumarins as a sensitizer, a thermosetting component, or a phthalocyanine blue pigment, and the thermosetting component is Or a thermosetting component having two or more cyclic ether groups and / or cyclic thioether groups in the molecule.

  In one embodiment of the present invention, the cured coating film may be green or blue.

  Furthermore, the present invention provides a cured coating film obtained by the above method for forming a solder resist pattern.

  The present invention also provides a printed wiring board having a cured coating film obtained by the above method for forming a solder resist pattern.

  In patterning of the solder resist layer during the production of a printed wiring board, by using the phototool of the present invention, it has a thick film and high-definition solder resist pattern without being affected by the absorption of ultraviolet light of the phthalocyanine blue pigment. It has become possible to provide printed wiring boards.

Hereinafter, the present invention will be described in detail.
The photo resist tool for exposure of a solder resist of the present invention is a photo tool having a photo mask as a constituent member used in an exposure process in forming a solder resist pattern, and a film having specific light absorption characteristics on the resist surface side of the photo mask. It is characterized by comprising. And as a film which has this specific light absorption characteristic, the film which has a function which cuts 50% or more of light of 370 nm or less among ultraviolet rays, and permeate | transmits 80% or more of light 400 nm or more is used. When such a film is affixed to a photomask, it is easily expected that 365 nm light will be significantly cut and the sensitivity will be lowered by exposure using a high-pressure mercury lamp. Therefore, PET protection affixed to a photomask for solder resist exposure Although the idea of using a protective film having such a light absorption property instead of a film is not common sense, the absorbance at a wavelength of 405 nm of the dried coating film is 0.2-1 per 25 μm film thickness. It has been found by the present inventors that a thick resist film having a high resolution can be formed for the alkali-developable photosensitive composition.

  In the present invention, “the absorbance at a wavelength of 405 nm of the dried coating film is 0.2 to 1.2 per 25 μm thickness” will be described in detail in Examples below. The film thickness of the coating film obtained by coating and drying, and a graph of absorbance at a wavelength of 405 nm at each film thickness, and the absorbance obtained by calculating the absorbance of the dried coating film with a film thickness of 25 μm from the approximate expression, It means being in the range of 0.2 to 1.2.

  The protective film that can be used in the present invention is not particularly limited as long as it has the above-described light absorption characteristics. For example, a thermoplastic film can be used, and among them, a polyethylene naphthalate film has the above-mentioned light absorption characteristics. And is suitably used in the phototool of the present invention. In addition, when the thermoplastic film itself does not satisfy the light absorption property, it may be used as a laminate film that is provided so as to satisfy the light absorption property by further laminating an ultraviolet absorber-containing layer. Furthermore, you may use what contained the ultraviolet absorber in the film itself.

  If exposure processing of a resist pattern is performed using the phototool of the present invention, even if the photosensitive composition used here contains a large amount of phthalocyanine blue pigment, the effect of ultraviolet absorption by the phthalocyanine blue is affected. It is possible to form a high-resolution resist pattern with a thick film without receiving it.

  Below, the photosensitive composition used suitably in the formation method of the soldering resist pattern exposed using the phototool of this invention is demonstrated.

  As for the photosensitive composition used suitably in the formation method of the soldering resist pattern of this invention, the light absorbency in wavelength 405nm of the dry coating film is 0.2-1.2 per film thickness of 25 micrometers, More preferably, 0.3- 0.8 is a photocurable or photocurable / thermosetting resin composition capable of alkali development, (A) a carboxylic acid-containing resin, (B) a structural part represented by the general formula (I) An oxime ester photopolymerization initiator containing α, an α-aminoacetophenone photopolymerization initiator containing a structural part represented by the general formula (II), and an acyl phosphine oxide containing a structural part represented by the general formula (III) One or more photopolymerization initiators selected from the group consisting of a photopolymerization initiator and a titanocene photopolymerization initiator represented by the general formula (IV), (C) two or more in the molecule Ethylenic Contains one or more sensitizers selected from compounds having an unsaturated group, (D) thermosetting component, (E) phthalocyanine blue pigment, and (F) diethylthioxanthone, diethylaminobenzophenone and coumarins Can do. In particular, by appropriately selecting the photopolymerization initiator (B) and the blue pigment (E), the absorbance at a wavelength of 405 nm of the dried coating film is 0.2 to 1.2 per 25 μm film thickness, more preferably 0.8. It is possible to adjust to 3 to 0.8. When the absorbance at a wavelength of 405 nm is lower than 0.2 per 25 μm, the decrease in sensitivity cannot be prevented. On the other hand, when the absorbance is higher than 1.2, an undercut occurs and it is difficult to obtain a high-definition pattern.

  As described above, in general, light having a wavelength of 365 nm, 405 nm, and 433 nm is used in exposure using a high-pressure mercury lamp, but 365 nm light is cut by exposure processing using the phototool of the present invention, and sensitivity is increased. It will be lower. However, the absorbance of the coating film at a wavelength of 405 nm is 0.2 to 1.2 per 25 μm of film thickness, and the alkali-developable photosensitive composition using a specific photopolymerization initiator has a single light of 405 nm. On the other hand, it was found that the sensitivity was high and the sensitivity was almost the same as that of a commercially available composition exposed with a composite beam of 365 nm, 405 nm, 433 nm or the like.

Hereinafter, each component will be described in detail.
As the carboxylic acid-containing resin (A) contained in the photosensitive composition of the present invention, a known and commonly used resin compound containing a carboxyl group in the molecule can be used. Furthermore, the carboxylic acid containing photosensitive resin which has an ethylenically unsaturated double bond in a molecule | numerator is more preferable from the surface of photocurability and image development resistance.
Specific examples include the resins listed below.

(1) a carboxylic acid-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid and one or more other compounds having an unsaturated double bond;
(2) Glycidyl (meth) acrylate or 3,4-epoxycyclohexyl is a copolymer of an unsaturated carboxylic acid such as (meth) acrylic acid and one or more other compounds having an unsaturated double bond. Carboxylic acid-containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant with a compound having an epoxy group and an unsaturated double bond, such as methyl (meth) acrylate, or (meth) acrylic acid chloride,
(3) Copolymerization of a compound having an unsaturated double bond with an epoxy group such as glycidyl (meth) acrylate or 3,4-epoxycyclohexylmethyl (meth) acrylate, and a compound having an unsaturated double bond other than that A carboxylic acid-containing photosensitive resin obtained by reacting an unsaturated carboxylic acid such as (meth) acrylic acid with the coalescence and reacting a polybasic acid anhydride with the generated secondary hydroxyl group,
(4) To a copolymer of an acid anhydride having an unsaturated double bond such as maleic anhydride and a compound having an unsaturated double bond other than that, a hydroxyl group such as 2-hydroxyethyl (meth) acrylate; A carboxylic acid-containing photosensitive resin obtained by reacting a compound having an unsaturated double bond,
(5) a carboxylic acid-containing photosensitive resin obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid such as (meth) acrylic acid, and reacting the resulting hydroxyl group with a saturated or unsaturated polybasic acid anhydride,
(6) After reacting a hydroxyl group-containing polymer such as a polyvinyl alcohol derivative with a saturated or unsaturated polybasic acid anhydride, the resulting carboxylic acid is reacted with an epoxy group and a compound having an unsaturated double bond in one molecule. Hydroxyl group-containing carboxylic acid-containing photosensitive resin obtained by
(7) Polyfunctional epoxy compound, unsaturated monocarboxylic acid such as (meth) acrylic acid, at least one alcoholic hydroxyl group in one molecule, and one reaction other than the alcoholic hydroxyl group that reacts with the epoxy group Carboxylic acid-containing photosensitive resin obtained by reacting a reaction product with a compound having a functional group (for example, dimethylolpropionic acid) with a saturated or unsaturated polybasic acid anhydride,
(8) A polyfunctional oxetane compound having at least two oxetane rings in one molecule is reacted with an unsaturated monocarboxylic acid such as (meth) acrylic acid, and the primary hydroxyl group in the resulting modified oxetane resin. A carboxylic acid-containing photosensitive resin obtained by reacting a saturated or unsaturated polybasic acid anhydride, and (9) an unsaturated monocarboxylic acid (for example, a cresol novolac type epoxy resin). (Meth) acrylic acid, etc.) and then a polybasic acid anhydride (for example, tetrahydrophthalic acid anhydride, etc.) to react with the carboxylic acid-containing photosensitive resin, Contains carboxylic acid obtained by reacting an oxirane ring with a compound having one or more ethylenically unsaturated groups (eg glycidyl (meth) acrylate) Examples thereof include, but are not limited to, photosensitive resins.

  Among these examples, preferred are the carboxylic acid-containing photosensitive resins (2), (5), (7), and (9), and particularly the carboxylic acid-containing photosensitive resin (9). From the viewpoints of photocurability and cured coating film properties.

  In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate, methacrylate, and mixtures thereof, and the same applies to other similar expressions.

  Since the carboxylic acid-containing resin (A) as described above has a number of free carboxyl groups in the side chain of the backbone polymer, development with a dilute aqueous alkali solution is possible.

  Moreover, the acid value of the said carboxylic acid containing resin (A) is the range of 40-200 mgKOH / g, More preferably, it is the range of 45-120 mgKOH / g. When the acid value of the carboxylic acid-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds, so that the line becomes thinner than necessary. Depending on the case, the exposed portion and the unexposed portion are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to draw a normal resist pattern.

  Moreover, although the weight average molecular weight of the said carboxylic acid containing resin (A) changes with resin frame | skeleton, what is generally in the range of 2,000-150,000, Furthermore, 5,000-100,000 is preferable. When the weight average molecular weight is less than 2,000, the tack-free performance may be inferior, the moisture resistance of the coated film after exposure may be poor, and the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

  The compounding quantity of such carboxylic acid containing resin (A) and / or carboxylic acid containing photosensitive resin (A ') is 20-60 mass% in the whole composition, Preferably it is 30-50 mass%. When the amount is less than the above range, the coating strength is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity becomes high and the coating property and the like deteriorate, which is not preferable.

The photopolymerization initiator (B) contained in the photosensitive composition of the present invention includes benzophenone, acetophenone, aminoacetophenone, benzoin ether, benzyl ketal, acylphosphine oxide, oxime ether, and oxime ester. And known conventional radical photopolymerization initiators such as titanocene, and oxime ester photopolymerization initiators containing a structural moiety represented by the following general formula (I), represented by the following general formula (II) An α-aminoacetophenone photopolymerization initiator containing a structural moiety, an acylphosphine oxide photopolymerization initiator containing a structural moiety represented by the following general formula (III), and a titanocene system represented by the following general formula (IV) It is preferable to contain one or more selected from the group consisting of photopolymerization initiators.

In the formula, R ¹ is a hydrogen atom, a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), an alkyl group having 1 to 20 carbon atoms (one or more It may be substituted with a hydroxyl group, and may have one or more oxygen atoms in the middle of the alkyl chain.), A cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms, or benzoyl Group (which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group). R ² is a phenyl group (which may be substituted with an alkyl group having 1 to 6 carbon atoms, a phenyl group or a halogen atom), or an alkyl group having 1 to 20 carbon atoms (which is substituted with one or more hydroxyl groups). And may have one or more oxygen atoms in the middle of the alkyl chain.), A cycloalkyl group having 5 to 8 carbon atoms, an alkanoyl group having 2 to 20 carbon atoms or a benzoyl group (having 1 carbon atom). To 6 alkyl groups or phenyl groups, which may be substituted). R ³ and R ⁴ each independently represents an alkyl group having 1 to 12 carbon atoms or an arylalkyl group, and R ⁵ and R ⁶ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Or two may combine to form a cyclic alkyl ether group. R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, an aryl group substituted with a halogen atom, an alkyl group or an alkoxy group, or 1 to 1 carbon atoms. 20 carbonyl groups (except when both are carbonyl groups having 1 to 20 carbon atoms). R ⁹ and R ¹⁰ each independently represents a halogen atom, an aryl group, a halogenated aryl group, or a heterocycle-containing halogenated aryl group.

As the oxime ester photopolymerization initiator containing the structural portion represented by the general formula (I), 1,2-octanedione-1- [4- (phenylthio) -2- (O-benzoyloxime)], Etanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), a compound represented by the following formula (I-1), 2 Examples include-(acetyloxyiminomethyl) thioxanthen-9-one, and compounds represented by the following general formula (I-2).

In formula (I-2), R ¹¹ has the same meaning as R ¹ in general formula (I), and R ¹² and R ¹⁴ each independently have the same meaning as R ² in general formula (I). R ¹³ is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a benzoyl group, an alkanoyl group having 2 to 12 carbon atoms, or an alkoxy having 2 to 12 carbon atoms. A carbonyl group (when the alkyl group constituting the alkoxyl group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, and has one or more oxygen atoms in the middle of the alkyl chain) Or a phenoxycarboxylic group.

  Among these, the compound represented by the above formula (I-1), 2- (acetyloxyiminomethyl) thioxanthen-9-one, and the compound represented by the general formula (I-2) are particularly preferable. Examples of commercially available compounds include CGI-325, Irgacure OXE01, and Irgacure OXE02 manufactured by Ciba Specialty Chemicals.

  Examples of the α-aminoacetophenone photopolymerization initiator containing the structural portion represented by the general formula (II) 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, N, N-dimethylaminoacetophenone, and the like. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by Ciba Specialty Chemicals.

  Examples of the acylphosphine oxide photopolymerization initiator containing the structural portion represented by the general formula (III) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenyl. Examples include phosphine oxide and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide. Examples of commercially available products include Lucilin TPO manufactured by BASF and Irgacure 819 manufactured by Ciba Specialty Chemicals.

Examples of the titanocene photopolymerization initiator represented by the general formula (IV) include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole). -1-yl) -phenyl) titanium. Commercially available products include Irgacure 784 manufactured by Ciba Specialty Chemicals.

  The blending ratio of such a photopolymerization polymerization initiator (B) is 0.01 to 30 parts by mass, preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A). It is. When the blending ratio of the photopolymerization initiator (B) is less than 0.01 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A), the photocurability on copper is insufficient and the coating film is peeled off. Or film properties such as chemical resistance are reduced. On the other hand, when the blending ratio of the photopolymerization initiator (B) exceeds 30 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A), deep curability is obtained due to light absorption of the photopolymerization initiator (B). Since it falls, it is not preferable.

  In the case of the oxime ester photopolymerization initiator represented by the formula (I-1), the blending ratio is preferably 0.01 to 20 with respect to 100 parts by mass of the carboxylic acid-containing resin (A). It is the ratio of a mass part, More preferably, 0.01-5 mass parts. When such an oxime ester photopolymerization initiator is used, it reacts with copper atoms at the interface with the copper foil, and the function as the photopolymerization initiator may be deactivated. It is preferable to use it together with a polymerization initiator or the like.

  The compound (C) having two or more ethylenically unsaturated groups in the molecule that can be contained in the photosensitive composition used in the present invention is photocured by ultraviolet irradiation, and the carboxylic acid-containing resin (A). Is insolubilized in an aqueous alkali solution or assists insolubilization. Examples of such compounds include glycol diacrylates such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate, and the like. Polyhydric acrylates such as polyhydric alcohols or their ethylene oxide adducts or propylene oxide adducts; Phenoxy acrylate, bisphenol A diacrylate, and polyhydric acrylates such as ethylene oxide adducts or propylene oxide adducts of these phenols Glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycy Ethers, polyvalent acrylates of glycidyl ethers such as triglycidyl isocyanurate; and melamine acrylate, and / or the like each methacrylates corresponding to the acrylates.

  Further, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, or a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. Examples thereof include an epoxy urethane acrylate compound obtained by reacting a half urethane compound. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

  The compounding ratio of the compound (C) having two or more ethylenically unsaturated groups in such a molecule is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A). Preferably, it is the ratio of 1-70 mass parts. When the blending ratio is less than 5 parts by mass, the photocurability is lowered, and pattern development becomes difficult by alkali development after ultraviolet irradiation, which is not preferable. On the other hand, when the amount exceeds 100 parts by mass, the solubility in an aqueous alkali solution is reduced and the coating film becomes brittle, which is not preferable.

  As the thermosetting component (D) that can be used in the present invention, amino resins such as melamine resins and benzoquaminamine resins, block isocyanate compounds, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, episulfide resins and the like are commonly used. The thermosetting resin can be used. Among these, thermosetting having two or more cyclic ether groups and / or cyclic thioether groups in the molecule such as the polyfunctional epoxy compound (D-1), the polyfunctional oxetane compound (D-2), and the episulfide resin. A component (hereinafter abbreviated as a cyclic (thio) ether compound) is particularly preferred.

  As the polyfunctional epoxy compound (D-1), for example, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004 manufactured by Japan Epoxy Resin, Epicron 840, Epicron 850, Epicron 1050 manufactured by Dainippon Ink & Chemicals, Inc. , Epicron 2055, Epototo YD-011, YD-013, YD-127, YD-128, manufactured by Tohto Kasei Co., Ltd., D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.E. E. R. 664, Ciba Specialty Chemicals' Araldide 6071, Araldide 6084, Araldide GY250, Araldide GY260, Sumitomo Chemical Industries Sumi-Epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei Kogyo Co., Ltd. A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); Epicoat YL903 manufactured by Japan Epoxy Resin, Epicron 152, Epicron 165 manufactured by Dainippon Ink and Chemicals, Epototo YDB-400, YDB- manufactured by Tohto Kasei Co., Ltd. 500, D.C. E. R. 542, Araldide 8011 manufactured by Ciba Specialty Chemicals, Sumi-epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., and A.D. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (all trade names); Epicoat 152 and Epicoat 154 manufactured by Japan Epoxy Resin Co., Ltd., D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865, Etototo YDCN-701, YDCN-704 from Toto Kasei Co., Ltd., Araldide ECN1235 from Ciba Specialty Chemicals, Araldide ECN1273, Araldide ECN1299, Araldide XPY307, Nippon Kayaku Co., Ltd. EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Chemical Industries Sumi-epoxy ESCN-195X, ESCN- 220, manufactured by Asahi Kasei Corporation. E. R. Novolak type epoxy resins such as ECN-235, ECN-299, etc. (both trade names); Epicron 830 manufactured by Dainippon Ink & Chemicals, Epicoat 807 manufactured by Japan Epoxy Resin, Epototo YDF-170 manufactured by Toto Kasei Co., YDF -175, YDF-2004, bisphenol F type epoxy resin such as Araldide XPY306 manufactured by Ciba Specialty Chemicals (all are trade names); Epotot ST-2004, ST-2007, ST-3000 manufactured by Tohto Kasei Hydrogenated bisphenol A type epoxy resin, such as Epicoat 604 manufactured by Japan Epoxy Resin Co., Ltd., Epotot YH-434 manufactured by Toto Kasei Co., Ltd., Araldide MY720 manufactured by Ciba Specialty Chemicals Co., Ltd., Sumitomo Chemical Co., Ltd. Epoxy ELM-120 etc. All are trade names) glycidylamine type epoxy resin; Hydantoin type epoxy resins such as Araldide CY-350 (trade name) manufactured by Ciba Specialty Chemicals; Celoxide 2021 manufactured by Daicel Chemical Industries, Ciba Specialty Chemicals Alicyclic epoxy resins such as Araldide CY175, CY179, etc. (both trade names) manufactured by YL-933 manufactured by Japan Epoxy Resin Co., Ltd. E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Japan Epoxy Resin YL-6056, YX-4000, YL-6121 (all trade names), etc. Xylenol-type or biphenol-type epoxy resins or mixtures thereof; bisphenol S type such as EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by Asahi Denka Kogyo Co., Ltd. Epoxy resin; Bisphenol A novolac type epoxy resin such as Epicoat 157S (trade name) manufactured by Japan Epoxy Resin; Epicoat YL-931 manufactured by Japan Epoxy Resin, Araldide 163 manufactured by Ciba Specialty Chemicals, etc. Name) Tetraphenylolethane type Poxy resin; Araldide PT810 manufactured by Ciba Specialty Chemicals, TEPIC manufactured by Nissan Chemical Industries, Ltd. (both are trade names); Diglycidyl phthalate resin such as Bremer DGT manufactured by Nippon Oil &Fats; Tetraglycidylxylenoylethane resin such as ZX-1063 manufactured by Nippon Steel; ESN-190 and ESN-360 manufactured by Nippon Steel Chemical Co., Ltd. Naphthalene groups such as HP-4032, EXA-4750, and EXA-4700 manufactured by Dainippon Ink & Chemicals, Inc. Epoxy resin; Epoxy resin having dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by Dainippon Ink &Chemicals; Glycidyl methacrylate copolymer epoxy resin such as CP-50S and CP-50M manufactured by Nippon Oil &Fats; In addition, cyclohexylmaleimide and glycidyl Methacrylate copolymerized epoxy resins; epoxy-modified polybutadiene rubber derivatives (for example, PB-3600 manufactured by Daicel Chemical Industries, Ltd.), CTBN-modified epoxy resins (for example, YR-102, YR-450 manufactured by Tohto Kasei Co., Ltd.), etc. However, it is not limited to these. These epoxy resins can be used alone or in combination of two or more. Among these, a novolac type epoxy resin, a heterocyclic epoxy resin, a bisphenol A type epoxy resin or a mixture thereof is particularly preferable.

  Examples of the polyfunctional oxetane compound (D-2) include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-Methyl-3-oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3- In addition to polyfunctional oxetanes such as ethyl-3-oxetanyl) methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane And novolac resin, poly (p-hydroxystyrene), cardo-type bisphenol Le ethers, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

  Examples of the compound having two or more cyclic thioether groups in the molecule include bisphenol A type episulfide resin YL7000 manufactured by Japan Epoxy Resins. Moreover, episulfide resin etc. which replaced the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthesis method can be used.

  The compounding ratio of such a cyclic (thio) ether compound is such that the cyclic (thio) ether group is 0.6 to 3.0 equivalents relative to 1 equivalent of the carboxyl group of the ethylenically unsaturated group-containing carboxylic acid-containing resin. Preferably, it is the range used as 0.8-2.5 equivalent. When the amount of the cyclic (thio) ether compound is less than the above range, the carboxyl group remains, which is not preferable because the heat resistance, alkali resistance, electrical insulation and the like are lowered. On the other hand, when the above range is exceeded, the low molecular weight cyclic (thio) ether group remains, which is not preferable because the strength of the coating film decreases.

  When using the said cyclic (thio) ether compound, it is preferable to contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N -Amine compounds such as dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid hydrazide and sebacic acid hydrazide; phosphorus compounds such as triphenylphosphine, etc. , For example, four 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all trade names of imidazole compounds) manufactured by Kasei Kogyo Co., Ltd., U-CAT3503N, U-CAT3502T (all are dimethylamine block isocyanate compounds) Product name), DBU, DBN, U-CATSA102, U-CAT5002 (both bicyclic amidine compounds and salts thereof). In particular, it is not limited to these, as long as it is a thermosetting catalyst for epoxy resins or oxetane compounds, or a catalyst that promotes the reaction of epoxy groups and / or oxetanyl groups with carboxyl groups, either alone or in combination of two or more. Can be used. Guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6-diamino-S-triazine, 2 S-triazine derivatives such as -vinyl-4,6-diamino-S-triazine / isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used, Preferably, a compound that also functions as an adhesion promoter is used in combination with the thermosetting catalyst.

  The blending ratio of the thermosetting catalyst may be a ratio usually used. For example, 0.1 to 20 parts by mass, preferably 0 to 100 parts by mass of the carboxylic acid-containing resin (A) or thermosetting component (D). 0.5 to 15.0 parts by mass.

  It is important that the photosensitive composition used in the resist pattern forming method of the present invention contains the phthalocyanine blue pigment (E). The inventors of the present invention have found that the gloss sensitivity can be obtained with a lower exposure amount when the phthalocyanine blue pigment (E) is added to a single light of 405 nm. The reason for the sensitization effect of this phthalocyanine blue pigment is not clear, but, for example, phthalocyanine blue is added to a resin composition having an absorbance of less than 0.2 per 25 μm of film thickness so that the absorbance is 0.2 or more. Sufficient surface curability and cure depth can be obtained at the same time with low exposure. In addition, this sensitizing effect is effective for surface reactivity (gloss improvement), and the curing depth is adversely affected. That is, it works to reflect exposure light. This function is also effective for stabilizing the resist shape.

  For example, when the cross-sectional shape of the resist pattern is viewed, when the phthalocyanine blue is not included and the absorbance is lower than 0.2, the cross-sectional shape of the resist is a shape having a widened bottom, and There is no gloss. Further, when phthalocyanine blue is not included and the absorbance is more than 1.2, there is a situation where the surface layer portion is greatly expanded and the bottom portion is thinned. However, when the absorbance is in the range of 0.2 to 1.2 and the photopolymerization initiator (B) and the phthalocyanine pigment (E) are contained, the resist film thickness is in the range of 5 to 100 μm. It has been found that a resist shape having a bottom portion of approximately the same size as the negative size of the photomask can be obtained and surface gloss can be obtained.

  The appropriate addition amount of such a phthalocyanine pigment (E) can be arbitrarily added as long as the absorbance at a wavelength of 405 nm of the dried coating film is 0.2 to 1.2 per 25 μm. For example, it can add in 0.01-5 mass parts with respect to 100 mass parts of carboxylic acid containing resin (A).

  As phthalocyanine pigments (E), α-type copper phthalocyanine blue, α-type monochloro copper phthalocyanine blue, β-type copper phthalocyanine blue, ε-type copper phthalocyanine blue, cobalt phthalocyanine blue, metal-free phthalocyanine blue, etc. Can be mentioned.

  The photosensitive composition suitably used in the present invention may contain other photopolymerization initiator, photoinitiator assistant and sensitizer in addition to the above-described photopolymerization initiator, such as benzoin compound, acetophenone compound, An anthraquinone compound, a thioxanthone compound, a ketal compound, a benzophenone compound, a xanthone compound, a tertiary amine compound, and the like can be given.

  Specific examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

  Specific examples of the acetophenone compound include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, and 1,1-dichloroacetophenone.

  Specific examples of the anthraquinone compound include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone.

  Specific examples of the thioxanthone compound include 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone.

  Specific examples of the ketal compound include acetophenone dimethyl ketal and benzyl dimethyl ketal.

  Specific examples of the benzophenone compound include, for example, benzophenone, 4-benzoyldiphenyl sulfide, 4-benzoyl-4′-methyldiphenyl sulfide, 4-benzoyl-4′-ethyldiphenyl sulfide, 4-benzoyl-4′-propyldiphenyl. Sulfide.

  Specific examples of the tertiary amine compound include, for example, an ethanolamine compound, a compound having a dialkylaminobenzene structure, such as 4,4′-dimethylaminobenzophenone (Nisso Cure MABP manufactured by Nippon Soda Co., Ltd.), 4,4′-diethylamino. Dialkylamino benzophenone such as benzophenone (EAB manufactured by Hodogaya Chemical Co.), and dialkylamino groups such as 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin) Containing coumarin compound, ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), ethyl 2-dimethylaminobenzoate (Quantacure DMB manufactured by International Bio-Synthetics), 4-dimethylaminobenzoic acid ( -Butoxy) ethyl (Quantacure BEA, manufactured by International Bio-Synthetics), p-dimethylaminobenzoic acid isoamyl ethyl ester (Kayacure DMBI, manufactured by Nippon Kayaku Co., Ltd.), 2-ethylhexyl 4-dimethylaminobenzoate (manufactured by Van Dyk) Esolol 507), 4,4′-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.).

  Of the above, thioxanthone compounds and tertiary amine compounds are preferred. The composition of the present invention preferably contains a thioxanthone compound from the viewpoint of deep curable properties. Among them, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone A thioxanthone compound such as

  The blending ratio of such a thioxanthone compound is preferably 20 parts by mass or less, more preferably 10 parts by mass or less with respect to 100 parts by mass of the carboxylic acid-containing resin (A). If the amount of the thioxanthone compound is too large, the thick film curability is lowered and the cost of the product is increased, which is not preferable.

  As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and among them, a dialkylaminobenzophenone compound and a dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 410 nm are particularly preferable. As the dialkylaminobenzophenone compound, 4,4'-diethylaminobenzophenone is preferable because of its low toxicity. The dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 410 nm has a maximum absorption wavelength in the ultraviolet region, so that it is less colored and uses a colored pigment as well as a colorless and transparent photosensitive composition. A colored solder resist film reflecting the color can be provided. In particular, 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one is preferable because it exhibits an excellent sensitizing effect on laser light having a wavelength of 400 to 410 nm.

  As a compounding ratio of such a tertiary amine compound, the ratio of 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, with respect to 100 parts by mass of the carboxylic acid-containing resin (A). It is. When the amount of the tertiary amine compound is less than 0.1 parts by mass, a sufficient sensitizing effect tends not to be obtained. When the amount exceeds 20 parts by mass, light absorption on the surface of the dried solder resist coating film by the tertiary amine compound becomes intense, and the deep curability tends to decrease.

  These photopolymerization initiators, photoinitiator assistants, and sensitizers can be used alone or as a mixture of two or more.

  The total amount of such photopolymerization initiator, photoinitiator assistant, and sensitizer is preferably in the range of 35 parts by mass or less with respect to 100 parts by mass of the carboxylic acid-containing resin (A). When it exceeds 35 parts by mass, the deep curability tends to decrease due to light absorption.

  In the photosensitive composition that can be used in the present invention, a filler can be blended, if necessary, in order to increase the physical strength of the coating film. As such a filler, known and commonly used inorganic or organic fillers can be used. In particular, barium sulfate, spherical silica and talc are preferably used. Furthermore, NANOCRYL (trade name) XP manufactured by Hanse-Chemie in which nano silica is dispersed in the compound (C) having two or more ethylenically unsaturated groups in the molecule and the polyfunctional epoxy resin (D-1). 0396, XP 0596, XP 0733, XP 0746, XP 0765, XP 0768, XP 0953, XP 0954, XP 1045 (all are product grade names), NANOPOX (trade name) manufactured by Hanse-Chemie, Inc. XP 0516, XP 05 , XP 0314 (both product grade names) can also be used. These may be used alone or in combination of two or more.

  The blending ratio of these fillers is preferably 300 parts by mass or less, more preferably 0.1 to 300 parts by mass, and still more preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A). The ratio of parts. When the blending ratio of the filler exceeds 300 parts by mass, it is not preferable because the viscosity of the composition becomes high and the printability is lowered or the cured product becomes brittle.

  Furthermore, the photosensitive composition that can be used in the present invention contains an organic solvent for the synthesis of the carboxylic acid-containing resin (A), the adjustment of the composition, or the adjustment of the viscosity for application to a substrate or a carrier film. Can be used.

  Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. More specifically, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl Glycol ethers such as ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate , Esters such as propylene glycol butyl ether acetate; ethanol, propano , Ethylene glycol, alcohols such as propylene glycol; octane, aliphatic hydrocarbons decane; petroleum ether is petroleum naphtha, hydrogenated petroleum naphtha, and petroleum solvents such as solvent naphtha.

  Such organic solvents are used alone or as a mixture of two or more.

  Moreover, in the photosensitive composition of this invention, coloring pigments other than a blue pigment can be added in the range which does not have a bad influence on resolution etc.

  The photosensitive composition that can be used in the present invention is, if necessary, known and commonly used thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine, fine silica, organic bentonite, montmorillonite, etc. Known and commonly used thickeners, silicone-type, fluorine-type and polymer-type antifoaming agents and / or leveling agents, imidazole-type, thiazole-type, triazole-type silane coupling agents, etc. Agents can be blended.

  In addition, a blue pigment other than the phthalocyanine blue pigment and a color pigment other than the blue pigment can be added within a range that does not adversely affect the resolution and the like.

  The photosensitive composition that can be used in the present invention is adjusted to a viscosity suitable for the coating method with the organic solvent, for example, on a circuit-formed substrate, dip coating method, flow coating method, roll coating method, bar coater method, A tack-free coating film can be formed by applying the organic solvent contained in the composition at a temperature of about 60 to 100 ° C. by volatile drying (temporary drying) at a temperature of about 60 to 100 ° C. Moreover, a resin insulation layer can be formed by apply | coating the said composition on a carrier film, bonding the dry film wound up as a film on the board | substrate which formed the circuit. Thereafter, the resist pattern is formed by selectively exposing with ultraviolet rays through a photomask on which a pattern is formed, and developing the unexposed portion with a dilute alkaline aqueous solution (for example, 0.3 to 3% sodium carbonate aqueous solution). Furthermore, when the thermosetting component is contained, for example, by heating to a temperature of about 140 to 180 ° C. and thermosetting, the carboxyl group of the carboxylic acid-containing resin (A) and two or more in the molecule It reacted with the thermosetting component (D) having a cyclic ether group and / or a cyclic (thio) ether group, and was excellent in various properties such as heat resistance, chemical resistance, moisture absorption resistance, adhesion, and electrical characteristics. A cured coating film can be formed.

  As the base material used for the substrate, paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / non-woven cloth epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluorine / polyethylene / PPO / cyanate ester, etc. are used. All grades (FR-4, etc.) of copper clad laminates, other polyimide films, PET films, glass substrates, ceramic substrates, wafer plates, etc. are used. Can do.

  In the present invention, the volatile drying performed after the photosensitive composition is applied may be performed by using a hot-air circulating drying furnace, an IR furnace, a hot plate, a convection oven, or the like (with a steam-heated air source). Can be carried out by using a countercurrent contact method and a method of spraying a nozzle to a support.

  The exposure apparatus used for the ultraviolet irradiation may be any exposure apparatus that generates ultraviolet light, and the light source is preferably a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, or the like. Examples of the exposure apparatus include HMW-680GW manufactured by Oak Manufacturing Co., Ltd. and ADEX 600P manufactured by Adtech Engineering Co., Ltd., which can be used in the present invention.

  Examples of the developing method include a dipping method, a shower method, a spray method, a brush method, and the like. As the developer, potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, An alkaline aqueous solution such as tetramethylammonium hydroxide can be used.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Synthesis example 1
Into a 2 liter separable flask equipped with a stirrer, thermometer, reflux condenser, dropping funnel and nitrogen introduction tube, a cresol novolac type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., EOCN-104S, softening point 92 ° C., epoxy) (Equivalent = 220 g / equivalent)) 660 g, carbitol acetate 421.3 g, and solvent naphtha 180.6 g were charged, heated and stirred at 90 ° C., and dissolved. Next, it is once cooled to 60 ° C., 216 g of acrylic acid, 4.0 g of triphenylphosphine and 1.3 g of methylhydroquinone are added and reacted at 100 ° C. for 12 hours, and a reaction product having an acid value of 0.2 mgKOH / g. Got. This was charged with 241.7 g of tetrahydrophthalic anhydride, heated to 90 ° C. and reacted for 6 hours. As a result, a non-volatile content = 65% by mass, a solid content acid value = 77 mgKOH / g, a double bond equivalent (g weight of resin per mol of unsaturated groups) = 400 g / equivalent, and a weight average molecular weight = 7,000 carvone A solution of the acid-containing photosensitive resin (A) was obtained. Hereinafter, this carboxylic acid-containing photosensitive resin solution is referred to as varnish A.

(Preparation of photosensitive composition No. 1-10)
Using varnish A obtained in Synthesis Example 1 above, blended in the proportions (parts by mass) shown in the same table together with various components shown in Table 1, premixed with a stirrer, kneaded with a three-roll mill, and soldered A photosensitive composition for resist was prepared. Here, when the dispersion degree of the obtained photosensitive composition was evaluated by particle size measurement using a grindometer manufactured by Eriksen, all the samples were 15 μm or less.

Resist performance evaluation:
<Absorbance>
For the measurement of absorbance, an ultraviolet-visible spectrophotometer (Ubest-V-570DS manufactured by JASCO Corporation) and an integrating sphere device (ISN-470 manufactured by JASCO Corporation) were used. After applying the photocurable / thermosetting resin composition of Formulation Examples 1 to 10 to a glass plate, it is dried at 80 ° C. for 30 minutes using a hot air circulating drying oven, and is a photocurable / thermosetting resin. A dry coating film of the composition was prepared on a glass plate. Using an ultraviolet-visible spectrophotometer and an integrating sphere device, an absorbance baseline at 500 to 300 nm was measured on the same glass plate as that applied with the photocurable / thermosetting resin composition. The absorbance of the produced glass plate with the dried coating film was measured, and the absorbance of the dried coating film could be calculated from the baseline, and the absorbance of the target light at a wavelength of 405 nm was obtained. In order to prevent the deviation of the absorbance due to the deviation of the coating thickness, this operation is performed by changing the coating thickness by the applicator into four stages, and a graph of the coating thickness and the absorbance at 405 nm is prepared. The absorbance of the film was calculated and used as each absorbance.

The absorbance evaluation results are shown in Table 2.

<Cross sectional shape>
A circuit printing substrate having a line / space of 300/300 μm and a copper thickness of 50 μm was subjected to buffing, washing with water and drying, followed by screen printing. It is applied and dried in a hot air circulation drying oven at 80 ° C. for 30 minutes. After drying, exposure was performed using an exposure apparatus equipped with a high-pressure mercury lamp. As the exposure pattern, a pattern for drawing a 50/60/70/80/90/100 μm line in the space portion was used. The exposure amount was the exposure amount obtained by the following appropriate exposure amount evaluation. After exposure, development was performed with an aqueous sodium carbonate solution to form a pattern, and after irradiation with 1000 mJ / cm ² of ultraviolet light with a high-pressure mercury lamp, heat curing was performed at 150 ° C. for 60 minutes to obtain a cured coating film. The cross section of the line part of the designed value 100 μm of the cured coating film was observed.

  This cross-sectional shape was evaluated in five stages A to E as shown in the schematic diagram of FIG. In FIG. 1, evaluations A to E show schematic diagrams when the following phenomenon occurs. In particular, in the case of evaluation A, the deviation from the design value was within 5 μm for both the upper and lower parts of the line. The results are shown in Table 2. The worst evaluation here is E.

A evaluation: ideal state according to design width B evaluation: occurrence of biting of surface layer due to insufficient development resistance C evaluation: undercut state D evaluation: occurrence of line thickening due to halation etc. E evaluation: line thickening and undercut of surface layer Occurs.

  Here, not only A evaluation but also C evaluation and D evaluation are levels that can be used as solder resists. On the other hand, in the B evaluation and E evaluation, the line and the undercut portion are easily peeled off and are difficult to use as a solder resist. In particular, the E evaluation is at a level where it cannot be used.

<Appropriate exposure>
The photosensitive compositions of Formulation Examples 1 to 10 were applied to the entire surface of the evaluation substrate by screen printing. Then, the photomask which formed the negative pattern of a 50-130 micrometer line was exposed to the coating film after drying with the hot air circulation type dryer using the exposure apparatus carrying a high pressure mercury lamp. Thereafter, development was performed for 60 seconds with a 1.0 mass% aqueous sodium carbonate solution. At this time, the smallest exposure amount at which a resolution of 60 μm was obtained was determined as an appropriate exposure amount.

(Example 1: PET protective film is used as the protective film / resist film thickness 18 μm)
Section of solder resist pattern obtained when using a photo tool with a polyethylene terephthalate protective film (tack well 155) bonded to a photomask (negative pattern) during exposure in resist formation using a circuit pattern with a copper thickness of 20 μm The shape evaluation results are shown in Table 3. The film thickness of the solder resist layer at this time was 18 μm.

(Example 2: PEN-based protective film is used as the protective film / resist film thickness 18 μm)
The same test as in Example 1 was performed except that a polyethylene naphthalate film was used instead of the polyethylene terephthalate film as the protective film. The evaluation results of the cross-sectional shape of the obtained solder resist pattern were the same as in Table 3. The photomask was clean with no scratches or resist adhesion.

(Example 3: PET protective film used as protective film / resist film thickness 45 μm)
Section of solder resist pattern obtained when using a photo tool with a polyethylene terephthalate protective film (tack well 155) bonded to a photomask (negative pattern) during exposure in resist formation using a circuit pattern with a copper thickness of 50 μm The shape evaluation results are shown in Table 4. The film thickness of the solder resist at this time was 45 μm.

From Table 4, for Formulation Examples 8 to 10 that are not colored blue or green, although the cross-sectional shape of the resist pattern is relatively good, Formulation Examples 1 to 7 that are colored blue or green are undercuts or lines. Fatness was recognized.

(Example 4: Using a PEN-based protective film as a protective film / resist film thickness 45 μm)
The same test as in Example 3 was performed except that a polyethylene naphthalate film was used instead of the polyethylene terephthalate film as the protective film. Table 5 shows the evaluation results of the cross-sectional shape of the obtained solder resist pattern (film thickness: 45 μm). The photomask was clean with no scratches or resist adhesion.

From Table 5, when the exposure processing is performed using the phototool of the present invention, even when the resist layer has a thickness of 45 μm, if the absorbance of the photosensitive composition is within an appropriate range, it is undercut. It was found that high-definition patterns without the same can be obtained. This was particularly noticeable when the photosensitive resin was colored blue or green.

(Example 5: Use a protective film provided with a UV-absorbed film on a PET photomask / resist film thickness 45 μm)
As a protective film, the same test as in Example 3 was performed, except that a laminated film adjusted to have the light absorption characteristics of the present invention was laminated by laminating a film subjected to ultraviolet absorption treatment on a photomask made of polyethylene terephthalate. . The evaluation result of the cross-sectional shape of the obtained solder resist pattern was the same as in Table 5 and was 0.

  From the above, the protection adjusted to cut 50% or more of light of 370 nm or less and to transmit 80% or more of light of 400 nm or more with a photosensitive composition having an absorbance at 405 nm of 0.2 to 1.2 It was found that the process using the phototool of the present invention formed by attaching a film to a photomask gives a resist pattern having an excellent cross-sectional shape regardless of the thickness of the resist layer.

The schematic diagram which shows the cross-sectional shape of the pattern which consists of a cured coating film of a photosensitive composition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... Design value of line width 1b ... Resin composition after exposure and development 1c ... Substrate

Claims (6)

  A photomask used for an exposure process for forming a pattern of a solder resist made of an alkali-developable photosensitive composition having an absorbance at a wavelength of 405 nm of a dry coating film of 0.2 to 1.2 per 25 μm film thickness A photo tool comprising: a protective film that cuts 50% or more of light having a wavelength of 370 nm or less and transmits 80% or more of light having a wavelength of 400 nm or more on the resist surface side of the photomask. Photo tool to do.   The phototool according to claim 1, wherein the protective film is a thermoplastic film and contains an ultraviolet absorber.   The phototool according to claim 1, wherein the protective film is a protective film having an ultraviolet absorbing layer.   The phototool according to claim 1, wherein the protective film is a polyethylene naphthalate film.   Applying the alkali-developable photosensitive composition on a substrate, or applying the alkali-developable photosensitive composition to a film, laminating a dry film on the substrate, and laminating the resulting coating film On the other hand, after selectively irradiating ultraviolet rays through the phototool according to any one of claims 1 to 4, developing an unexposed portion and forming a pattern, the cured coating film is thermally cured by heating. A method for forming a solder resist pattern. To claim 5 obtained by the method of forming a solder resist pattern according to a printed wiring board thickness comprising a cured coating film in the range of 5 to 100 [mu] m, the cured coating film, the wavelength of the dry film It consists of a photosensitive composition capable of alkali development having an absorbance at 405 nm of 0.2 to 1.2 per 25 μm film thickness, and the deviation of the line width of the cured coating film from the negative dimension of the photomask is the line width. Printed wiring board that is within 5 μm at the top.

Images