JP5153304B2 - Photosensitive composition - Google Patents

Description

  The present invention relates to a photosensitive composition in which a pattern latent image is formed by a direct drawing (direct drawing) method using light from a lamp emitting ultraviolet rays, and the pattern latent image is developed with an aqueous alkali solution, and the composition is used as a carrier. The present invention relates to a dry film obtained by drying after coating on a film.

  A permanent protective film called a solder resist film is provided on the outermost layer of the printed wiring board. In order to form this solder resist film, a photoresist method that can accurately form a fine pattern is widely employed. Among them, the alkali development type photoresist method has become the mainstream because of environmental considerations.

  As one method of the photoresist method, a batch exposure method using light from a lamp emitting ultraviolet rays is widely known (Patent Document 1). This batch exposure method forms a pattern latent image in a very short time in order to expose the entire surface of the dried coating film with UV light through a photomask after the photosensitive composition is applied to the substrate and dried. can do. However, this batch exposure method requires alignment of the photomask with respect to the substrate, and this alignment takes time. Furthermore, the substrate is subject to a change in dimensions due to the thermal history at the time of circuit formation, and tends to deviate from the design value. On the other hand, since the photomask does not cause the dimensional change as described above, the position corresponding to the deviation of the base material cannot be corrected. The finer the pattern, the greater the influence of misalignment and the more difficult pattern latent image formation becomes. In order to form an accurate pattern latent image, it is necessary to measure the dimensions of each substrate after circuit formation, and to produce a corresponding photomask for each substrate, which is very complicated.

On the other hand, based on the data from a computer, the direct drawing (direct drawing) method which draws a pattern latent image directly on a dry solder resist coating film using the light from the lamp | ramp which generate | occur | produces an ultraviolet-ray is also used. In this direct drawing method, for the deviation from the design value of the base material dimension as described above, the dimension of the base material after circuit formation is measured, and the deviation from the design value is corrected by a computer. It is possible to form an accurate pattern latent image. Therefore, the direct drawing method can form a fine pattern latent image more accurately and easily than the batch exposure method.
JP 01-141904 A

  However, since the direct drawing method draws a pattern latent image by scanning ultraviolet light on the substrate, the time required to form the pattern latent image on one substrate is longer than that of the batch exposure method. Longer and less prone to productivity. Therefore, in order to increase productivity, a highly sensitive photosensitive composition that can be used for high-speed direct drawing is desired. When the sensitivity of the photosensitive composition is low, a pattern latent image cannot be sufficiently formed by high-speed direct drawing, that is, irradiation with ultraviolet light for a short time. A general ultraviolet curable photosensitive composition has a sensitivity of 200 mJ to 600 mJ, and this sensitivity range is low to expose and cure a thick dry solder resist coating film by a direct drawing method.

  Accordingly, an object of the present invention is to provide a highly sensitive photosensitive composition that can be suitably used in a direct drawing method using light from a lamp that generates ultraviolet rays.

  That is, a photosensitive composition in which a pattern latent image is formed by a direct drawing method using light from a lamp that generates ultraviolet rays, and the pattern latent image is developed with an alkaline aqueous solution. A photosensitive composition having an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 375 nm per 25 μm thickness and an absorbance of 0.3 to 0.6 at a wavelength of 405 nm provide.

  Moreover, according to the other side surface of this invention, the dry film obtained by apply | coating the photosensitive composition by the 1st side surface of this invention on a carrier film, and drying is provided.

  The photosensitive composition of the present invention has high sensitivity and can be suitably used for a direct drawing method using light from a lamp that generates ultraviolet rays. The photosensitive composition of the present invention can accurately form a desired pattern latent image even when irradiated with a low exposure amount of ultraviolet light.

  Hereinafter, the present invention will be described in more detail.

  The photosensitive composition of the present invention is a photosensitive composition in which a pattern latent image is formed by a direct drawing method using light from a lamp that generates ultraviolet rays, and the pattern latent image is developed with an alkaline aqueous solution. The previous dried coating film exhibits an absorbance of 0.6 to 1.2 in the wavelength range of 355 to 375 nm and an absorbance of 0.3 to 0.6 at a wavelength of 405 nm per 25 μm thickness. When the dry coating film before exposure of the photosensitive composition of the present invention exhibits an absorbance in the above range per 25 μm thickness, it can be suitably used for the ultraviolet direct drawing method. Specifically, when the dry coating film before exposure exhibits an absorbance of 0.6 to 1.2 in the wavelength range of 355 to 375 nm, the incident light is largely absorbed by the surface layer portion of the dry coating film and the surface is cured. In addition, by exhibiting an absorbance of 0.3 to 0.6 at a wavelength of 405 nm, high sensitivity is realized by transmitting light to the bottom of the dried coating film and obtaining a sufficient curing depth.

  Here, in the present invention, “the dried coating film before exposure exhibits an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 375 nm per 25 μm thickness, and 0.3 to 0.00 at a wavelength of 405 nm. "Showing the absorbance of 6" will be described in detail in Examples below, but there are four different thicknesses of the dried coating film obtained by applying and drying the photosensitive composition paste, and the thickness of each dried coating film. The absorbance obtained by preparing a graph of absorbance at a wavelength of 355 to 375 nm and calculating the absorbance of a dry coating film having a thickness of 25 μm from the approximate expression is in the range of 0.6 to 1.2, and is photosensitive. For the dried coating film obtained by applying and drying the composition paste, four different thicknesses and absorbance graphs at a wavelength of 405 nm at the thickness of each dried coating film are prepared. Absorbance obtained by calculating the absorbance of the coating film, which means that in the range of 0.3 to 0.6.

  Further, in the present invention, “the difference between the maximum absorbance in the wavelength range of 355 to 375 nm and the absorbance at the wavelength of 405 nm is 0.3 or more per 25 μm thickness of the dried coating film before exposure” As will be described in detail in the examples, graphs of absorbance at wavelengths of 355 to 375 nm at four different thicknesses and thicknesses of the respective dry coating films were prepared for the dry coating films obtained by applying and drying the photosensitive composition paste. From the approximate expression, the maximum absorbance obtained by calculating the absorbance of a dry coating film having a film thickness of 25 μm, the four different thicknesses of the dry coating film obtained by applying and drying the photosensitive composition paste, A graph of absorbance at a wavelength of 405 nm in the thickness of the film is prepared, and the absorbance difference obtained by calculating the absorbance of the dried coating film having a thickness of 25 μm from the approximate expression is 0.3. Which means that it is above.

  Further, in the present invention, “the dried coating film before exposure exhibits an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 375 nm per 25 μm thickness, and 0.3 to 0.00 at a wavelength of 405 nm. "The difference between the maximum absorbance in the wavelength range of 355 to 375 nm and the absorbance at the wavelength of 405 nm is 0.3 or more and less than 0.6", which will be described in detail in Examples below. Then, graphs of the absorbance at wavelengths of 355 to 375 nm for the dry coating films obtained by applying and drying the photosensitive composition paste and the thicknesses of the respective dry coating films are prepared, and the film thickness is calculated from the approximate expression. The absorbance obtained by calculating the absorbance of a 25 μm dry coating film is in the range of 0.6 to 1.2, and the dry coating film obtained by applying and drying the photosensitive composition paste. The graph shows the absorbance at a wavelength of 405 nm for each of the four different thicknesses and the thickness of each dried coating film, and the absorbance obtained by calculating the absorbance of the dried coating film with a film thickness of 25 μm from the approximate expression is 0.3 to Graphs of absorbance at wavelengths of 355 to 375 nm for four different thicknesses and dry coating thicknesses obtained by applying and drying the photosensitive composition paste in the range of 0.6 are prepared. From the approximate expression, the maximum absorbance obtained by calculating the absorbance of the dried coating film having a film thickness of 25 μm, the four different thicknesses of the dried coating film obtained by applying and drying the photosensitive composition paste, A graph of absorbance at a wavelength of 405 nm in the thickness of the coating film is prepared, and the absorbance difference obtained by calculating the absorbance of the dried coating film with a film thickness of 25 μm from the approximate expression is 0.3 to 0.6. Which means that it is full.

  When the dry coating film before exposure of the photosensitive composition of the present invention exhibits an absorbance of less than 0.6 in the wavelength range of 355 to 375 nm, the surface layer portion has insufficient light absorption, and the surface There is a tendency for curing to be insufficient. If the absorbance exceeds 1.2, the surface hardening proceeds excessively and the light tends to be blocked from transmitting to the bottom, which is not preferable. In addition, when the dry coating film before exposure exhibits an absorbance of less than 0.3 at a wavelength of 405 nm, the light that is not absorbed by the dry coating film, for example, hits the copper foil on the substrate and is reflected, and the solder resist shape changes. This is not preferable because it has a tendency to Moreover, when the light absorbency exceeds 0.6, there exists a tendency which cannot fully permeate | transmit light to the bottom part of a dry coating film, and is unpreferable.

  In the photosensitive composition of the present invention, the difference between the maximum absorbance in the wavelength range of 355 to 375 nm and the absorbance at the wavelength of 405 nm is 0.3 or more per 25 μm of the thickness of the dried coating film before exposure. preferable. When the difference in absorbance is 0.3 or more, the above-described surface curing and curing depth can be effectively obtained, and the photosensitive composition of the present invention can be made more sensitive. If the difference in absorbance is less than 0.3, a longer exposure time tends to be required in order to obtain sufficient surface hardening and hardening depth.

  Furthermore, the photosensitive composition of the present invention has a dry coating film before exposure that has an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 375 nm per thickness of 25 μm and 0 at a wavelength of 405 nm. The difference between the maximum absorbance in the wavelength range of 355 to 375 nm and the absorbance at the wavelength of 405 nm is preferably 0.3 or more and less than 0.6. When the absorbance satisfies the above requirements, the composition of the present invention becomes more sensitive. If the difference in absorbance exceeds 0.6, it is difficult to obtain sufficient surface hardening and hardening depth at the same time, which is not preferable.

  As the photosensitive composition of the present invention, those containing (A) a carboxylic acid-containing resin, (B) a photopolymerization initiator, and (C) a pigment can be used.

  As the carboxylic acid-containing resin (A), 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 photosensitivity obtained by adding an ethylenically unsaturated group as a pendant by reacting an epoxy group such as methyl (meth) acrylate with an unsaturated double bond or (meth) acrylic acid chloride resin,
(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 saturated or unsaturated polybasic acid anhydride with a hydroxyl group-containing polymer such as a polyvinyl alcohol derivative, the resulting carboxylic acid is reacted with a compound having an epoxy group and 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 resins, preferred are the carboxylic acid-containing photosensitive resins (2), (5), (7), and (9), and particularly the carboxylic acid-containing photosensitive resin (9) above. It is preferable in terms of photocurability and cured coating film characteristics.

  In addition, in this specification, (meth) acrylate is a term that collectively refers to acrylate and methacrylate, and the same applies to other similar expressions. These acrylate compounds and methacrylate compounds may be used alone or in combination of two or more.

  Since the carboxylic acid-containing resin (A) as described above has a carboxyl group in the side chain of the backbone polymer, development with an alkaline aqueous solution becomes possible.

  The acid value of the carboxylic acid-containing resin (A) is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. If the acid value of the carboxylic acid-containing resin is less than 40 mgKOH / g, alkali development becomes difficult, which is not preferable. On the other hand, if it exceeds 200 mgKOH / g, dissolution of the exposed portion by the developer proceeds, so the line may be thinner than necessary, or in some cases, dissolution and peeling may occur with the developer without distinguishing between the exposed portion and the unexposed portion, Since it is difficult to draw a normal solder resist pattern, it is not preferable.

  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) can be selected from the range of 20-60 mass% based on the total mass of the photosensitive composition of this invention, Preferably it is 30-50 mass%. If it is less than 20% by mass, the coating strength tends to decrease, such being undesirable. On the other hand, if it exceeds 60% by mass, the viscosity becomes high and the coating property and the like deteriorate, which is not preferable.

As the photopolymerization initiator (B), an oxime ester photopolymerization initiator having a group represented by the following general formula (I), an α-aminoacetophenone-based light having a group represented by the following general formula (II) It is preferable to use a polymerization initiator or one or more photopolymerization initiators selected from the group consisting of acylphosphine oxide photopolymerization initiators having a group represented by the following formula (III).

(Where
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), or an alkyl group having 1 to 20 carbon atoms (substituted with one or more hydroxyl groups). Which 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 (carbon number) May be substituted with 1 to 6 alkyl groups or phenyl groups),
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 may be substituted with one or more hydroxyl groups). It 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 to 6 carbon atoms) Which may be substituted with an alkyl group or a phenyl group of
R ³ and R ⁴ each independently represents an alkyl group having 1 to 12 carbon atoms or an arylalkyl group,
R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl ether group in which two are bonded,
R ⁷ and R ⁸ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl substituted with a halogen atom, an alkyl group or an alkoxy group Represents one group, provided that one of R ⁷ and R ⁸ represents an R—C (═O) — group (wherein R represents a hydrocarbon group having 1 to 20 carbon atoms).

The oxime ester photopolymerization initiator having a group represented by the general formula (I) is preferably 2- (acetyloxyiminomethyl) thioxanthen-9-one represented by the following formula (IV),

Compound represented by the following general formula (V)

(Where
R ⁹ 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. 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 phenoxycarbonyl group,
R ¹⁰ and R ¹² are each independently 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 Which 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 a benzoyl group (Which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group),
R ¹¹ 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), or an alkyl group having 1 to 20 carbon atoms (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 a carbon number). Which may be substituted with 1 to 6 alkyl groups or phenyl groups)),
Compound represented by the following general formula (VI)

(Where
R ¹³ and R ¹⁴ each independently represents an alkyl group having 1 to 12 carbon atoms,
R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,
M represents O, S or NH, and m and n represent an integer of 0 to 5)
Is mentioned. Among these, 2- (acetyloxyiminomethyl) thioxanthen-9-one represented by the following formula (IV) and a compound represented by the formula (V) are more preferable. Examples of commercially available products include CGI-325, Irgacure OXE01, and Irgacure OXE02 manufactured by Ciba Specialty Chemicals. These oxime ester photopolymerization initiators can be used alone or in combination of two or more.

  Examples of the α-aminoacetophenone photopolymerization initiator having the group 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 having a group represented by the general formula (III) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine. Examples thereof include oxides 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.

  The blending amount of such a photopolymerization initiator (B) is in the range of 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). You can choose from. If it is less than 0.01 parts by mass, the photocurability on copper is insufficient, and the coating film is peeled off or the coating film properties such as chemical resistance are deteriorated. On the other hand, if it exceeds 30 parts by mass, light absorption on the surface of the solder resist coating film of the photopolymerization initiator (B) becomes violent and the deep curability tends to decrease, which is not preferable.

  In the case of the oxime ester photopolymerization initiator having a group represented by the formula (I), the blending amount is preferably 0.01 to 100 parts by mass of the carboxylic acid-containing resin (A). It is desirable to select from 20 parts by mass, more preferably from 0.01 to 5 parts by mass. Since such an oxime ester photopolymerization initiator (I) reacts with a copper atom at the interface with the copper foil and the function as a photopolymerization initiator may be deactivated, α-aminoacetophenone photopolymerization It is preferable to use together with initiator (II) etc.

As the pigment (C) contained in the photosensitive composition of the present invention, a phthalocyanine blue pigment is preferably contained. It has been found by the present inventors that the surface curability can be obtained with a lower exposure amount when a phthalocyanine blue pigment is added to light having a wavelength of 405 nm. The reason for the sensitizing effect of the phthalocyanine blue pigment is not clear, but for example, phthalocyanine blue is added to a photosensitive composition having an absorbance of less than 0.3 per 25 μm of film thickness to make the absorbance 0.3 or more. A sufficient surface curability and a curing depth can be obtained at a low exposure amount at the same time. 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 the exposed light. This function is also effective for stabilizing the shape of the solder resist film. Examples of phthalocyanine blue pigments include α-type copper phthalocyanine blue, α-type monochloro copper phthalocyanine blue, β-type copper phthalocyanine blue, ε-type copper phthalocyanine blue, cobalt phthalocyanine blue, and metal-free phthalocyanine blue. ) Can be added arbitrarily as long as the absorbance at a wavelength of 405 nm of the dried coating film of the photosensitive composition is within a range of 0.3 to 0.6 per 25 μm. It is the range of 0.01-5 mass parts with respect to 100 mass parts of acid containing resin (A).

  Other examples of photopolymerization initiators, photoinitiator assistants and sensitizers that can be suitably used in the photosensitive composition of the present invention include benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, A xanthone compound, a tertiary amine compound, etc. can be mentioned.

  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 amount 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 light having a wavelength of 400 to 410 nm.

  The amount of such a tertiary amine compound is preferably 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 0.1 parts by mass or less, there is a tendency that a sufficient sensitizing effect cannot 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 photocurable resin composition of the present invention, in order to impart heat resistance, two or more cyclic ether groups and / or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) are included in the molecule. The thermosetting component (D) it has can be mix | blended.

  The thermosetting component (D) having two or more cyclic (thio) ether groups in such a molecule is either a three-, four- or five-membered cyclic ether group or a cyclic thioether group in the molecule. Or a compound having two or more of two types of groups, for example, a compound having at least two epoxy groups in the molecule, that is, a polyfunctional epoxy compound (D-1), at least two oxetanyl in the molecule A compound having a group, that is, a polyfunctional oxetane compound (D-2), a compound having two or more thioether groups in the molecule, that is, an episulfide resin (D-3), and the like.

  Examples of the polyfunctional epoxy compound (D-1) include, for example, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004, 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 Toto 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 Alcohol and novolak resin, poly (p-hydroxystyrene), cardo type Scan phenols, 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 (D-3) 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 blending amount of the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is preferably 0.6 to 2. with respect to 1 equivalent of the carboxyl group of the carboxylic acid-containing resin. It is 0 equivalent, More preferably, it exists in the range used as 0.8-1.5 equivalent. When the blending amount of the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is less than 0.6, carboxyl groups remain in the solder resist film, resulting in heat resistance, alkali resistance, electricity This is not preferable because the insulating property is lowered. On the other hand, when the amount exceeds 2.0 equivalents, the low molecular weight cyclic (thio) ether group remains in the dry coating film, which is not preferable because the strength of the coating film decreases.

  When the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is used, 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 dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine, and those that are commercially available ,example 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., U-CAT3503N, U-CAT3502T (both dimethylamine block isocyanate compounds) Product names), DBU, DBN, U-CATSA102, U-CAT5002 (both bicyclic amidine compounds and salts thereof), and the like. 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. Also, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine and isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adducts can also be used. A compound that also functions in combination with the thermosetting catalyst.

  The compounding amount of these thermosetting catalysts is sufficient in the usual quantitative ratio, for example, carboxylic acid-containing resin (A) or thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule. Preferably it is 0.1-20 mass parts with respect to 100 mass parts, More preferably, it is 0.5-15.0 mass parts.

  The photosensitive composition of the present invention can contain a filler as 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 0396, XP 0596, XP 0733 manufactured by Hanse-Chemie, in which nano silica is dispersed in the compound having one or more ethylenically unsaturated groups or the polyfunctional epoxy resin (D-1), 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 0525, XP 0314 (all are product grades) Name) can also be used. These may be used alone or in combination of two or more.

  The blending amount of these fillers is preferably 300 parts by mass or less, more preferably 0.1 to 300 parts by mass, and particularly preferably 0.1 to 150 parts by mass with respect to 100 parts by mass of the carboxylic acid-containing resin (A). Part. When the blending amount of the filler exceeds 300 parts by mass, the viscosity of the photosensitive composition is increased, the printability is lowered, and the cured product becomes brittle.

  Furthermore, the photosensitive composition of the present invention uses 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 do.

  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.

  If necessary, the photosensitive composition of the present invention may be a known conventional thermal polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine, etc. Thickeners, silicone-based, fluorine-based, polymer-based antifoaming agents and / or leveling agents, imidazole-based, thiazole-based, triazole-based silane coupling agents, antioxidants, rust inhibitors, etc. Such known and commonly used additives can be blended.

  The photosensitive composition of the present invention is adjusted to a viscosity suitable for the coating method using, for example, the above organic solvent, and a dip coating method, a flow coating method, a roll coating method, a bar coater method, a screen printing method on a circuit-formed substrate. 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). The dry coating film of the photosensitive composition of the present invention preferably has a thickness of 15 to 100 μm. Moreover, a dry film can be obtained by apply | coating the photosensitive composition of this invention on a carrier film, and making it dry. A solder resist film can be formed on the circuit-formed substrate by attaching the film wound up as a film to a circuit-formed substrate and peeling the carrier film. Then, after drawing a pattern latent image with a direct drawing apparatus (ultraviolet direct imaging apparatus), the unexposed portion is developed with an alkaline aqueous solution (for example, 0.3 to 3% sodium carbonate aqueous solution) to form a solder resist pattern. 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 The cyclic (thio) ether group of the thermosetting component (D) having a cyclic (thio) ether group reacts and is 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.

  Volatile drying performed after the photosensitive composition of the present invention is applied may be performed by using a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, etc. A method of making a countercurrent contact and a method of spraying on a support from a nozzle).

The light source used for the direct drawing method using light from a lamp that generates ultraviolet rays can be selected from a high pressure mercury lamp, an ultrahigh pressure mercury lamp, and a light source that simultaneously irradiates i-line (365 nm) and h-line (405 nm). Moreover, although the exposure amount changes with the dry film thickness etc. of the photosensitive composition of this invention, generally 5-100 mJ / cm < ² >, Preferably it is 5-60 mJ / cm < ² >, More preferably, it is 5-30 mJ / cm < ² >. Can be within range. As the direct drawing device, for example, a device manufactured by Dainippon Screen Co., Ltd. can be used.

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

<Synthesis of carboxylic acid-containing resin>
To 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, 421.3 g of carbitol acetate and 180.6 g of solvent naphtha as a solvent were charged and dissolved by heating and stirring at 90 ° C. Next, the mixture was once cooled to 60 ° C., 216 g of acrylic acid, 4.0 g of triphenylphosphine as a reaction catalyst, and 1.3 g of methylhydroquinone as a polymerization inhibitor were added and reacted at 100 ° C. for 12 hours. A reaction product of 2 mg KOH / g was obtained. 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 An acid-containing resin solution was obtained. Hereinafter, this carboxylic acid-containing resin solution is referred to as A-1 varnish.

Examples 1-5, Comparative Examples 1-2
The components shown in Table 1 were blended and stirred in the amounts (parts by mass) shown in the same table, and dispersed with three rolls to obtain photosensitive compositions.

  In order to examine various properties of the solder resist films formed using the compositions of Examples 1 to 5 and Comparative Examples 1 and 2, they were tested and evaluated as follows.

(1) Absorbance Each photosensitive composition was coated on a glass plate with an applicator and then dried at 80 ° C. for 30 minutes using a hot-air circulating drying furnace to prepare a dried coating film on the glass plate. About the dry coating film of each photosensitive composition on this glass plate, an ultraviolet-visible spectrophotometer (Ubest-V-570DS manufactured by JASCO Corporation) and an integrating sphere device (ISN-470 manufactured by JASCO Corporation) were used. The absorbance was measured. Moreover, the light absorbency baseline in the wavelength range of 300-500 nm was measured about the glass plate same as the glass plate which apply | coated each photosensitive composition. The absorbance of the dried coating film was calculated by subtracting the baseline from the absorbance of the prepared glass sheet with the dried coating film. This operation was carried out by changing the coating thickness with an applicator in four stages, and a graph of dry film thickness and absorbance was prepared. From this graph, the absorbance at a dry solder resist film thickness of 25 μm was determined. The results are shown in Table 2 for Examples 1 to 5 and Comparative Examples 1 and 2, respectively.

(2) Hardening depth and cross-sectional shape After buffling a circuit pattern substrate with a width of 300 μm / 300 μm and a copper thickness of 70 μm (line (part where copper foil is laminated) / space (part where copper foil is not laminated)) Washed with water and dried. On the circuit pattern substrate, each composition was applied by a screen printing method and dried in a hot air circulation drying oven at 80 ° C. for 30 minutes. After drying, the dried coating film was exposed using various exposure apparatuses. As the exposure pattern, a pattern in which lines of 30/40/50/60/70/80/90/100 μm were drawn in order in the space portion described above was used. After exposure, a solder resist pattern was obtained by performing development using a 1.0 part by mass sodium carbonate aqueous solution. At this time, the minimum remaining line width was used as the evaluation of the curing depth.

Moreover, evaluation of cross-sectional shape was performed by observing the cross section of the line part whose design value of a cured coating film is 100 micrometers. Here, the thickness of the solder resist film when the copper thickness was 70 μm was 65 μm. The cross-sectional shape was evaluated in five stages A to E according to the schematic diagram of FIG. The status of each evaluation is as follows:
A evaluation: Ideal state according to the design width,
B evaluation: Surface layer erosion due to insufficient development resistance, etc.
C evaluation: undercut state,
D evaluation: Line thickening occurs due to halation, etc.
E evaluation: Line thickening and undercut of the surface layer occur.

  Here, both undercut and halation are terms indicating deviation from the design value. Undercut particularly indicates that the lower part is thinner than the design value, and halation indicates that one or both of the upper part and the lower part is thicker than the design value.

  In particular, in the A evaluation, the deviation from the design value was assumed to be within 5 μm at both the upper and lower parts of the line.

  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.

An evaluation result is shown in Table 3 about Examples 1-5 and Comparative Examples 1-2.

Example 6
Example 1 shown in Table 1 was diluted with methyl ethyl ketone, applied onto a carrier film, dried by heating with a hot air dryer at 80 ° C. for 30 minutes, and a photocurable / thermosetting resin composition layer having a thickness of 25 μm was formed. Then, a cover film was laminated thereon to obtain a dry film. Thereafter, the cover film is peeled off, the film is heat laminated and bonded to the patterned copper foil substrate, and then exposed under the conditions of Example 1 shown in Table 3 to remove the carrier film. An image was obtained by developing with a mass% aqueous sodium carbonate solution for 60 seconds. Further, heat curing was performed with a hot air dryer at 150 ° C. for 60 minutes to prepare a test substrate. About the test substrate which has the obtained cured film, the evaluation test of each characteristic was done with the test method and evaluation method which were mentioned above. The result was the same as the result of Example 1 in Table 3.

  As described above in detail, according to the present invention, it is possible to provide a highly sensitive photosensitive composition that can be suitably used in a direct drawing method using light from a lamp emitting ultraviolet light. The photosensitive composition of the present invention can accurately form a desired pattern latent image even when irradiated with a low exposure amount of ultraviolet light.

The schematic diagram of the cross-sectional shape of the soldering resist film obtained after exposing to the dry coating film of the photosensitive composition of this invention, and developing this.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... Design value of line width 1b ... Solder resist film after exposure and development 1c ... Substrate

Claims (10)

A photosensitive composition for forming a pattern latent image by a direct drawing method using light from a lamp that generates ultraviolet light, and developing the pattern latent image with an alkaline aqueous solution, wherein the photosensitive composition comprises (A) The dried coating film before exposure containing a carboxylic acid-containing resin, (B) a photopolymerization initiator, and (C) a pigment having a thickness of 0.6 to 1.2 in a wavelength range of 355 to 375 nm per 25 μm thickness Showing absorbance and showing an absorbance of 0.3-0.6 at a wavelength of 405 nm,
The photopolymerization initiator (B) is an oxime ester photopolymerization initiator having a group represented by formula (I), an α-aminoacetophenone photopolymerization initiator having a group represented by formula (II), And one or more photopolymerization initiators selected from the group consisting of acylphosphine oxide photopolymerization initiators having a group represented by formula (III), and (B) blending of photopolymerization initiators The amount is 0.01 to 30 parts by mass with respect to 100 parts by mass of the (A) carboxylic acid-containing resin, and the amount of the (C) pigment is 100 parts by mass of the (A) carboxylic acid-containing resin. 0.01-5 mass parts with respect to the photosensitive composition characterized by the above-mentioned.

(Where
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), or an alkyl group having 1 to 20 carbon atoms (substituted with one or more hydroxyl groups). Which 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 (carbon number) May be substituted with 1 to 6 alkyl groups or phenyl groups),
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 may be substituted with one or more hydroxyl groups). It 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 to 6 carbon atoms) Which may be substituted with an alkyl group or a phenyl group of
R ³ and R ⁴ each independently represents an alkyl group having 1 to 12 carbon atoms or an arylalkyl group,
R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cyclic alkyl ether group in which two are bonded,
R ⁷ and R ⁸ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl substituted with a halogen atom, an alkyl group or an alkoxy group Represents one group, provided that one of R ⁷ and R ⁸ represents an R—C (═O) — group (wherein R represents a hydrocarbon group having 1 to 20 carbon atoms).   2. The photosensitive film according to claim 1, wherein the difference between the maximum absorbance at a wavelength range of 355 to 375 nm and the absorbance at a wavelength of 405 nm per 25 μm thickness of the dried coating film before exposure is 0.3 or more. Sex composition.   The dried coating film before exposure exhibits an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 375 nm and an absorbance of 0.3 to 0.6 at a wavelength of 405 nm per 25 μm thickness; The photosensitive composition according to claim 1 or 2, wherein the difference between the maximum absorbance at a wavelength range of 355 to 375 nm and the absorbance at a wavelength of 405 nm is 0.3 or more and less than 0.6. The photosensitive composition according to any one of claims 1 to 3, wherein the oxime ester photopolymerization initiator having a group represented by the formula (I) contains a compound of the formula (IV). object.

The photosensitive composition according to any one of claims 1 to 3, wherein the oxime ester photopolymerization initiator having a group represented by the formula (I) contains a compound of the formula (V). object.

(Where
R ⁹ 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. 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 phenoxycarbonyl group,
R ¹⁰ and R ¹² are each independently 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 Which 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 a benzoyl group (Which may be substituted with an alkyl group having 1 to 6 carbon atoms or a phenyl group),
R ¹¹ 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), or an alkyl group having 1 to 20 carbon atoms (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 a carbon number). 1-6 alkyl group or phenyl group). The said pigment (C) contains a phthalocyanine blue pigment, The photosensitive composition as described in any one of Claims 1-5 characterized by the above-mentioned. The photosensitive composition according to any one of claims 1 to 6 , further comprising a thermosetting component (D) having two or more cyclic ether groups and / or cyclic thioether groups in the molecule. . The light source used for the direct drawing method using the light from the lamp that generates ultraviolet rays is selected from among a high pressure mercury lamp, an ultra high pressure mercury lamp, and those that simultaneously irradiate i-line (365 nm) and h-line (405 nm). the photosensitive composition according to any one of claims 1 to 7, characterized. The photosensitive composition according to any one of claims 1-8, characterized in that it is applied as a dry film thickness of 15 to 100 m. Dry film obtained a photosensitive composition according to any one of claims 1 to 9 and dried after application on a carrier film.

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