KR20080044193A - Process for forming solder resist film and photosensitive composition - Google Patents

Abstract

A method for forming a solder resist film is provided to sufficiently harden a coating film formed from a photosensitive composition, from the surface to the core of the coating film. A method for forming a solder resist film includes the steps of: coating a substrate with a photosensitive composition, and drying the coated substrate; irradiating the dry coating film with a first laser light and a second laser light having a wavelength different from the wavelength of the first laser light, thereby forming a patterned latent image irradiated with the first and second laser lights; and performing development using an alkali aqueous solution. The photosensitive composition forms the unexposed dry coating film which shows an absorbance of 0.6-1.2 in the wavelength range of 355-380 nm and an absorbance of 0.3-0.6 in the wavelength of 405 nm, per 25 micron thickness of the coating film.

Description

Solder Resist Film Formation Method and Photosensitive Composition {PROCESS FOR FORMING SOLDER RESIST FILM AND PHOTOSENSITIVE COMPOSITION}

After apply | coating a photosensitive composition to a base material and drying, after irradiating a laser beam to this dry coating film, the formation method of the soldering resist film formed by developing with aqueous alkali solution, the photosensitive composition used for this method, and the said composition are used on a carrier film. It is related with the dry film obtained by drying after apply | coating.

The outermost layer of a printed wiring board is provided with the permanent protective film called a soldering resist film. In order to form this soldering resist, the photoresist method which can form a fine pattern correctly is employ | adopted widely. Among them, the alkali developing photoresist method is the mainstream due to environmental considerations.

As one method of the photoresist method, the batch exposure method using the light from the lamp which emits ultraviolet-ray is widely known, For example, it is disclosed by Unexamined-Japanese-Patent No. 01-141904. In this batch exposure method, after a photosensitive composition is apply | coated to a base material and dried, the light from the lamp which emits an ultraviolet-ray is exposed to the dry coating film whole surface through a photomask. Therefore, a pattern latent image can be formed in a very short time. However, this batch exposure method requires a position registration with respect to the substrate of the photomask, and this position registration takes time. In addition, the substrate is easily changed in dimension due to the thermal history at the time of forming the circuit, and easily causes a difference from the design value. On the other hand, since the photomask does not generate the above-described dimensional change, the position corresponding to the difference of the substrate cannot be corrected. The finer the pattern, the greater the influence of the difference, making it difficult to form an accurate pattern of latent image. In order to form an accurate pattern latent image, it is necessary to measure the dimension after circuit formation of each base material, and to manufacture the corresponding photomask for every base material, it is very complicated.

In contrast, the direct drawing method using laser light draws a pattern latent image directly on a dry solder resist coating film using light of a single wavelength from a laser light source based on data from a computer (International Publication No. WO02 / 096969). . This direct drawing method can measure the dimensions of the substrate after circuit formation for the difference from the design value of the substrate dimension as described above, correct the difference from the design value with a computer, and form the desired 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.

However, the direct drawing method scans the laser light on the substrate to draw the pattern latent image. For this reason, the time for forming a pattern latent image on one base material by the direct drawing method becomes longer compared with the batch exposure method, and there exists a tendency for productivity to fall. Therefore, in order to raise productivity, the high sensitive photosensitive composition which can be used for high speed direct drawing is calculated | required. When the sensitivity of the photosensitive composition is low, a pattern latent image cannot be fully formed by high speed direct drawing, ie, irradiation of laser light for a short time. Typical ultraviolet curable photosensitive compositions have a sensitivity of 200 mJ to 600 mJ. This sensitivity range is low enough to expose and harden a dry solder resist coating film of a thick film by the direct drawing method.

In addition, a single wavelength is used in the laser direct drawing method. In general, the use of shorter wavelength laser light has the advantage that the energy of the light beam is high, so that curing can proceed quickly, while light tends to be difficult to transmit to the core. It tends to be lowered. The use of a longer wavelength laser light has the advantage that light reaches the deep part of the dry coating film of the photosensitive composition and the curing depth is increased. On the other hand, since the energy of light is low, the efficiency is poor and the curing takes time. In addition, since the coating film surface is easy to receive hardening inhibition by oxygen, there existed a tendency for sufficient surface hardening not to be obtained.

An object of the present invention is to solve the defects of each other while utilizing the advantages of a shorter wavelength laser light and a longer wavelength laser light, and to solder the coating film formed from the photosensitive composition from the surface to the deep portion sufficiently. It is providing the resist film formation method and the highly sensitive photosensitive composition which can be used suitably for the said method.

In order to solve the above object, according to the first aspect of the present invention, after the photosensitive composition is applied to a substrate and dried, two or more laser lights having different wavelengths are irradiated to the dried coating film, thereby providing the two or more laser lights. After forming the pattern latent image irradiated respectively, it develops by alkaline aqueous solution, The formation method of the soldering resist film characterized by the above-mentioned is provided.

According to another aspect of the present invention, after the photosensitive composition is applied to a substrate and dried, the dried coating film is irradiated with a first laser light and a second laser light having a different wavelength from the first laser light, and the After forming the pattern latent image irradiated with both the 1st laser light and the 2nd laser light, it develops by alkaline aqueous solution, The formation method of the soldering resist film characterized by the above-mentioned.

Furthermore, according to another aspect of the present invention, there is provided a photosensitive composition used in the method for forming a soldering resist film according to the first aspect, wherein a dry coating film before exposure thereof has an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 380 nm per 25 μm in thickness. And a light absorbency of 0.3 to 0.6 at a wavelength of 405 nm.

Moreover, according to another aspect of this invention, the dry film obtained by drying after apply | coating said photosensitive composition on a carrier film is provided.

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

In the method of forming the solder resist film of the present invention, after applying the photosensitive composition to a substrate and drying, the dry coating film is irradiated with two or more laser lights having different wavelengths, and a pattern latent image irradiated with the two or more laser lights, respectively. After formation, it is developed by aqueous alkali solution.

In particular, in the method for forming the solder resist film of the present invention, the photosensitive composition is applied to a substrate and dried, and then the dried coating film is irradiated with a first laser light and a second laser light having a different wavelength from the first laser light. After forming the pattern latent image to which both the said 1st laser light and the 2nd laser light were irradiated, it develops by aqueous alkali solution.

Both laser light are irradiated to the dry coating film of the photosensitive composition by irradiating two or more laser lights with different wavelengths, for example, a 1st laser light and a 2nd laser light with a different wavelength from a 1st laser light. The dried coating film portion thus cured can be sufficiently cured to form a pattern latent image (a portion to which both laser light is irradiated). In the irradiation of laser light having two or more different wavelengths, any laser light may be irradiated first, regardless of the order. It is also possible to irradiate laser light having two or more different wavelengths at the same time.

Hereinafter, the aspect which uses two laser beams, a 1st laser beam and a 2nd laser beam, is demonstrated.

Semiconductor laser light and solid state laser light can be used for the 1st laser light and the 2nd laser light used for the formation method of the soldering resist film of this invention. In particular, it is preferable that either one of the first laser light or the second laser light is blue violet laser light (for example, 405 nm). The other laser light is usually ultraviolet laser light. The light source of the first laser light and the second laser light may be provided in one laser irradiation apparatus.

In the method for forming the solder resist film of the present invention, the dry coating film before exposure shows an absorbance of 0.6 to 1.2 in a wavelength range of 355 to 380 nm per 25 μm in thickness, and an absorbance of 0.3 to 0.6 at a wavelength of 405 nm. The photosensitive composition of this invention shown can be used suitably. Specifically, the dry coating film before exposure exhibits an absorbance of 0.6 to 1.2 in the wavelength range of 355 to 380 nm on the short wavelength side, whereby the incident light is absorbed largely at the surface layer portion of the dry coating film to harden the surface and at the long wavelength side. By exhibiting an absorbance of 0.3 to 0.6 at a wavelength of 405 nm of, high sensitivity is achieved by transmitting light to the bottom of the dry coating film to obtain a sufficient curing depth.

Here, in the present invention, "the dry coating film before exposure shows the absorbance of 0.6-1.2 in the wavelength range of 355-380 nm, and shows the absorbance of 0.3-0.6 in the wavelength of 405 nm per 25 micrometers in thickness." Although it demonstrates in detail in the Example mentioned later, about the dry coating film obtained by apply | coating and drying a photosensitive composition paste, the graph of four different thicknesses and the absorbance in wavelength 355-380 nm in the thickness of each dry coating film is created, The absorbance obtained by calculating the absorbance of the dry coating film having a film thickness of 25 μm from the approximation formula is in the range of 0.6 to 1.2, and four different thicknesses and respective dry coating films with respect to the dry coating film obtained by applying and drying the photosensitive composition paste. A graph of absorbance at wavelength 405 nm at the thickness of To calculate the absorbance of the coating tank means that the range of the absorbance obtained from 0.3 to 0.6.

In addition, in this invention, "the difference between the maximum absorbance in the wavelength range of 355-380 nm and the absorbance in the wavelength of 405 nm is 0.3 or more and 0.6 or less per 0.6 micrometer thickness of the dry coating film before exposure" is mentioned later. Although the Example demonstrates in detail, about the dry coating film obtained by apply | coating and drying a photosensitive composition paste, the graph of four different thicknesses and the absorbance in wavelength 355-380 nm in the thickness of each dry coating film is created, and the approximation is carried out. The maximum absorbance obtained by calculating the absorbance of the dry coating film having a film thickness of 25 µm from the formula, and the absorbance at the wavelength of 405 nm at four different thicknesses and the thickness of each dry coating film with respect to the dry coating film obtained by coating and drying the photosensitive composition paste. Absorbance obtained by making a graph of the graph and calculating the absorbance of the dry coating film having a thickness of 25 µm from the approximation formula The difference means that at least 0.3 less than 0.6.

In the present invention, "the dry coating film before exposure shows an absorbance of 0.6 to 1.0 at a wavelength of 355 nm, a absorbance of 0.3 to 0.5 at a wavelength of 405 nm, and a wavelength of 355 nm. The difference in absorbance between the absorbance and the absorbance at a wavelength of 405 nm is 0.3 or more and less than 0.5 ", which will be described in detail in Examples later, but with four different thicknesses for the dry coating film obtained by applying and drying the photosensitive composition paste, A graph of the absorbance at wavelength 355 nm in the thickness of each dry coating film was prepared, and the absorbance obtained by calculating the absorbance of the dry coating film having a thickness of 25 μm from the approximation formula was in the range of 0.6 to 1.0, and the photosensitive composition paste Four different thicknesses with respect to the dried coating film obtained by apply | coating and drying, and the wavelength in 405 nm in the thickness of each dry coating film A graph of the absorbance was prepared, and the absorbance obtained by calculating the absorbance of a dry coating film having a thickness of 25 µm from the approximation formula was in the range of 0.3 to 0.5, and was obtained in the same manner as described above at wavelengths of 355 nm and 405 nm. It means that the difference in absorbance obtained by calculating the absorbance of a dry coating film having a film thickness of 25 µm is 0.3 or more and less than 0.5.

When the dry coating film before exposure of the photosensitive composition of this invention shows absorbance less than 0.6 in the wavelength range of 355-380 nm, there exists a tendency for the absorption of the light in surface layer part to be inadequate, and surface hardening to be inadequate. In the case where the absorbance is greater than 1.2, it is not preferable because the surface hardening proceeds excessively and tends to block the transmission of light to the bottom. In addition, when the dry coating film before exposure shows the absorbance of less than 0.3 in the wavelength of 405 nm, the light which is not absorbed by a dry coating film, for example hits and reflects copper foil on a board | substrate, and has a tendency to change a soldering resist shape. Because it is not desirable. Moreover, when showing absorbance exceeding 0.6, it exists in the tendency which cannot transmit a light enough to the bottom part of a dry coating film, and is unpreferable.

Moreover, it is preferable that the photosensitive composition of this invention is the difference of the maximum absorbance in the wavelength range of 355-380 nm and the absorbance in the wavelength of 405 nm per thickness of 25 micrometers of the dry coating film before exposure is 0.3 or more and less than 0.6. Since the difference in absorbance exists in this range, the above-mentioned surface hardening and hardening depth can be obtained effectively, and the photosensitive composition of this invention can be made more highly sensitive. If the difference in absorbance is less than 0.3, longer exposure time tends to be necessary to obtain sufficient surface hardening and depth of cure. Moreover, when it exceeds 0.6, it will become difficult to obtain sufficient surface hardening and hardening depth simultaneously, and it is unpreferable.

Moreover, the photosensitive composition of this invention shows the absorbance of 0.6-1.0 at the wavelength of 355 nm, and the dry coating film before exposure shows the absorbance of 0.3-0.5 at the wavelength of 405 nm, and also at 355 nm wavelength. It is preferable that the difference between the absorbance at and the absorbance at a wavelength of 405 nm is 0.3 or more and less than 0.5.

As the photosensitive composition of this invention, what contains (A) carboxylic acid containing resin, (B) photoinitiator, and (C) pigment can be used.

As carboxylic acid containing resin (A), the well-known conventional resin compound which contains a carboxyl group in a molecule | numerator can be used. Moreover, the carboxylic acid containing photosensitive resin which has an ethylenically unsaturated double bond in a molecule | numerator is more preferable at the point of photocurability and developability.

Specifically, resin as enumerated below is mentioned.

(1) Carboxylic acid containing resin obtained by copolymerizing unsaturated carboxylic acid, such as (meth) acrylic acid, and at least 1 sort (s) of the compound which has another unsaturated double bond,

(2) Glycidyl (meth) acrylate and 3,4-epoxycyclohexyl to a copolymer of unsaturated carboxylic acids such as (meth) acrylic acid and one or more kinds of compounds having other unsaturated double bonds Carboxylic acid containing photosensitive resin obtained by adding an ethylenically unsaturated group as a pendant by making compound and (meth) acrylic acid chloride which have an unsaturated double bond, such as methyl (meth) acrylate, react,

(3) A copolymer 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 Carboxylic acid containing photosensitive resin obtained by making unsaturated carboxylic acid, such as (meth) acrylic acid, react, and making polybasic acid anhydride react with the produced | generated secondary hydroxyl group,

(4) A hydroxyl group such as 2-hydroxyethyl (meth) acrylate and an unsaturated double bond are added 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. Carboxylic acid-containing photosensitive resin obtained by reacting a compound having,

(5) Carboxylic acid containing photosensitive resin obtained by making a polyfunctional epoxy compound react unsaturated monocarboxylic acids, such as (meth) acrylic acid, and making a hydroxyl group react with saturated or unsaturated polybasic anhydride,

(6) A hydroxyl group-containing carboxyl obtained by reacting a saturated or unsaturated polybasic anhydride with a hydroxyl group-containing polymer such as a polyvinyl alcohol derivative, and then reacting the resulting carboxylic acid with a compound having an epoxy group and an unsaturated double bond in one molecule. Acid-containing photosensitive resin,

(7) Compounds having a polyfunctional epoxy compound, unsaturated monocarboxylic acids such as (meth) acrylic acid, and at least one alcoholic hydroxyl group in one molecule and one reactive group other than the alcoholic hydroxyl group reacting with the epoxy group (for example , Carboxylic acid-containing photosensitive resin obtained by reacting a saturated or unsaturated polybasic anhydride with a reaction product with dimethylolpropionic acid)

(8) Saturated or unsaturated polybasic acid anhydride with respect to the primary hydroxyl group in the modified oxetane resin obtained by making unsaturated monocarboxylic acid, such as (meth) acrylic acid, react with the polyfunctional oxetane compound which has two or more oxetane rings in 1 molecule. Carboxylic acid-containing photosensitive resin obtained by making it react, and

(9) After reacting an unsaturated monocarboxylic acid (for example, (meth) acrylic acid, etc.) to a polyfunctional epoxy resin (for example, a cresol novolak-type epoxy resin, etc.), polybasic acid anhydride (for example, tetra In addition to the carboxylic acid-containing photosensitive resin obtained by reacting hydrophthalic anhydride etc., the compound which has one oxirane ring and one or more ethylenically unsaturated group in a molecule | numerator (for example, glycidyl (meth) acrylate, etc.) Although the carboxylic acid containing photosensitive resin etc. which are obtained by making it react) are mentioned, it is not limited to these.

Preferred among these resins are carboxylic acid-containing photosensitive resins of the above (2), (5), (7) and (9), and in particular, the carboxylic acid-containing photosensitive resin of the above (9) is photocurable and cured coating film characteristics. Preferred at

In addition, in this specification, (meth) acrylate is a term which generically refers to acrylate and methacrylate, and it is the same also about another similar expression. These acrylate compounds and methacrylate compounds may be used alone or in combination of two or more thereof.

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 aqueous alkali solution becomes possible.

Moreover, the acid value of the said carboxylic acid containing resin (A) becomes like this. Preferably it is in the range of 40-200 mgKOH / g, More preferably, it is in the range of 45-120 mgKOH / g. If the acid value of the carboxylic acid-containing resin is less than 40 mgKOH / g, alkali development becomes difficult and undesirable. On the other hand, if it exceeds 200 mgKOH / g, since the dissolution of the exposed portion by the developing solution proceeds, the line becomes thinner than necessary, or in some cases, melted and peeled off with the developing solution without distinction between the exposed portion and the unexposed portion, and the normal solder resist It is not preferable because the drawing of the pattern becomes difficult.

Moreover, although the weight average molecular weight of the said carboxylic acid containing resin (A) changes with resin frame | skeleton, it is preferable to exist in the range of 2,000-150,000 normally, and also 5,000-100,000. When the weight average molecular weight is less than 2,000, the adhesion-free performance may be deteriorated, and the moisture resistance of the coating film after exposure is poor, and a film decrease may occur at the time of development, and the resolution may be greatly reduced. On the other hand, when the weight average molecular weight exceeds 150,000, developability may be significantly worse, and storage stability may be inferior.

The compounding quantity of such carboxylic acid containing resin (A) can be selected in 20-60 mass%, Preferably it is 30-50 mass% based on the total mass of the photosensitive composition of this invention. When it is less than 20 mass%, since coating film strength tends to fall, it is not preferable. On the other hand, when it exceeds 60 mass%, since viscosity becomes high, applicability | paintability etc. fall, it is not preferable.

As a photoinitiator (B), the oxime ester system photoinitiator which has group represented by following formula (1), the (alpha)-amino acetophenone system photoinitiator which has group represented by following formula (2), and the acyl phosphine jade which has group represented by following formula (3) It is preferable to use 1 or more types of photoinitiators selected from the group which consists of a seed type photoinitiator.

(In the meal,

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 (can be substituted with one or more hydroxyl groups, one in the middle of the alkyl chain Or 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 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), an alkyl group having 1 to 20 carbon atoms (can be substituted with one or more hydroxyl groups, and at least one oxygen atom 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 ³ and R ⁴ each independently represent an alkyl group or an arylalkyl group having 1 to 12 carbon atoms,

R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cyclic alkylether group having two bonded thereto,

R ⁷ and R ⁸ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl group substituted with a halogen atom, an alkyl group or an alkoxy group, provided that One of R ⁷ and R ⁸ may represent an RC (═O) -group, where R is a hydrocarbon group of 1 to 20 carbon atoms

As an oxime ester type photoinitiator which has group represented by the said Formula (1), Preferably, 2- (acetyloxyiminomethyl) thioxanthene-9-one represented by following formula (4), the compound represented by following formula (5), and the following The compound represented by General formula (6) is mentioned.

(In the meal,

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, and an alkoxycarbonyl group having 2 to 12 carbon atoms (alkoxy When the alkyl group constituting the actual group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, may have 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 (can be substituted with one or more hydroxyl groups, and in the middle of the alkyl chain May have one or more oxygen atoms), 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), an alkyl group having 1 to 20 carbon atoms (can be substituted with one or more hydroxyl groups, and at least one in the middle of the alkyl chain May have an oxygen atom), 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)

(In the meal,

R ¹³ and R ¹⁴ each independently represent 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,

m and n represent integers from 0 to 5)

Especially, the compound represented by 2- (acetyloxyiminomethyl) thioxanthene-9-one represented by the said Formula (4), and Formula (5) is more preferable. As a commercial item, CGI-325, Irgacure OXE01, Irgacure OXE02, etc. made by Ciba Specialty Chemicals, etc. are mentioned. These oxime ester photoinitiators can be used individually or in combination of 2 or more types.

Examples of the α-aminoacetophenone-based photopolymerization initiator having a group represented by the formula (2) include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropaneone-1 and 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, etc. are mentioned. Examples of commercially available products include Irgacure 907, Irgacure 369, Irgacure 379, and the like manufactured by Ciba Specialty Chemicals.

As an acyl phosphine oxide type photoinitiator which has group represented by the said Formula (3), 2,4,6- trimethyl benzoyl diphenyl phosphine oxide, bis (2, 4, 6- trimethyl benzoyl)-phenylphosphine oxide, bis ( 2, 6- dimethoxy benzoyl) -2, 4, 4- trimethyl- pentyl phosphine oxide, etc. are mentioned. Examples of commercially available products include Lucirin TPO manufactured by BASF Corporation, Irgacure 819 manufactured by Ciba Specialty Chemicals, Inc., and the like.

The compounding quantity of such a photoinitiator (B) can be chosen in 0.01-30 mass parts with respect to 100 mass parts of said carboxylic acid containing resins (A), Preferably it is the range of 0.5-15 mass parts. If it is less than 0.01 mass part, since the photocurability on copper is inadequate and peeling off a coating film or coating-film characteristics, such as chemical-resistance, it is unpreferable. On the other hand, when it exceeds 30 mass parts, since the light absorption in the soldering resist coating film surface of a photoinitiator (B) becomes deep and deep-curing property tends to fall, it is unpreferable.

On the other hand, in the case of the oxime ester type photoinitiator which has group represented by the said General formula (1), the compounding quantity becomes like this. Preferably it is 0.01-20 mass parts, More preferably, 0.01 with respect to 100 mass parts of said carboxylic acid containing resin (A). It is preferable to select in the range of-5 parts by mass. Since such an oxime ester type photoinitiator (I) may react with a copper atom in the interface with copper foil, and the function as a photoinitiator may be inactivated, it is preferable to use together with (alpha)-amino acetophenone type photoinitiator (II).

As the pigment (C) contained in the photosensitive composition of this invention, it is preferable that a phthalocyanine blue pigment is contained. It was discovered by the present inventors etc. that the photosensitive composition which added the phthalocyanine blue pigment with respect to the light of a single wavelength of 405 nm (laser light) is obtained by lower exposure amount. Although the reason for the sensitization effect of this phthalocyanine blue type pigment is not clear, For example, phthalocyanine blue is added to the photosensitive composition whose absorbance per film thickness of 25 micrometers is less than 0.3, and sufficient absorbency and surface hardening are made into 0.3 or more. Depth is simultaneously obtained with a low exposure amount. Moreover, this sensitization effect is effective in surface reactivity (gloss improvement), and hardening depth worsens on the contrary. In other words, it functions to reflect the exposed light. This function is also effective for stabilizing the shape of the solder resist. Examples of the 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.

The appropriate addition amount of such a pigment (C) can be added arbitrarily as long as the absorbance in the wavelength of 405 nm of the dry coating film of a photosensitive composition becomes 0.3 to 0.6 per 25 micrometers, for example, carboxylic acid containing resin (A ) 0.01 to 5 parts by mass relative to 100 parts by mass.

In addition, as a photoinitiator, a photoinitiator, and a sensitizer which can be used suitably for the photosensitive composition of this invention, a benzoin compound, an acetophenone compound, an anthraquinone compound, a thioxanthone compound, a ketal compound, a benzophenone compound, a xanthone A compound, a tertiary amine compound, etc. are 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, for example, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, and 2,4-diisopropyl thioxanthone. to be.

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'-propyldiphenylsulfide.

Specific examples of the tertiary amine compound include, for example, an ethanolamine compound and a compound having a dialkylaminobenzene structure, for example, 4,4'-dimethylaminobenzophenone (Nissocure MABP manufactured by Nippon Soda Co., Ltd.). And dialkylaminobenzophenones such as 4,4'-diethylaminobenzophenone (EAB manufactured by Hodogaya Chemical Co., Ltd.) and 7- (diethylamino) -4-methyl-2H-1-benzopyran-2- Dialkylamino group-containing coumarin compounds such as on (7- (diethylamino) -4-methylcoumarin), ethyl 4-dimethylaminobenzoate (Kayacure EPA manufactured by Nippon Kayaku Co., Ltd.), 2-dimethylaminobenzoate ethyl (International Bio -Quantacure DMB manufactured by Synthetics Co., Ltd., 4-dimethylaminobenzoic acid (n-butoxy) ethyl (Quantacure BEA manufactured by International Bio-Synthetics Co., Ltd.), isoamylethyl ester of p-dimethylaminobenzoic acid (manufactured by Nippon Kayaku Co., Ltd.) Kayacure DMBI), 2-ethylhexyl 4-dimethylaminobenzoic acid (Esol, manufactured by Van Dyck) ol 507) and 4,4'- diethylamino benzophenone (EAB by Hodogaya Chemical Co., Ltd.).

Among the above, thioxanthone compounds and tertiary amine compounds are preferable. It is preferable that the composition of the present invention contains a thioxanthone compound in terms of core hardenability, and in particular, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 2, Thioxanthone compounds, such as 4-diisopropyl thioxanthone, are preferable.

As a compounding quantity of such a thioxanthone compound, Preferably it is 20 mass parts or less, More preferably, it is the ratio of 10 mass parts or less with respect to 100 mass parts of said carboxylic acid containing resins (A). When the compounding quantity of a thioxanthone compound is too large, since thick film sclerosis | hardenability will fall and it will lead to the cost increase of a product, it is unpreferable.

As the tertiary amine compound, a compound having a dialkylaminobenzene structure is preferable, and 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 also preferable because of its low toxicity. The dialkylamino group-containing coumarin compound having a maximum absorption wavelength of 350 to 410 nm has little coloration because the maximum absorption wavelength is in the ultraviolet region, so that not only the colorless transparent solder photosensitive composition can be used but also the color of the colored pigment itself using a color pigment. It becomes possible to provide the reflecting colored solder resist. 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 quantity of such a tertiary amine compound, Preferably it is 0.1-20 mass parts with respect to 100 mass parts of said carboxylic acid containing resin (A), More preferably, it is the ratio of 0.1-10 mass parts. When the compounding quantity of a tertiary amine compound is 0.1 mass part or less, there exists a tendency for sufficient sensitization effect to not be acquired. When it exceeds 20 mass parts, the light absorption in the surface of the dry solder resist coating film by a tertiary amine compound will become deep, and there exists a tendency for deep-part sclerosis | hardenability to fall.

These photoinitiators, photoinitiator, and sensitizer can be used individually or as a mixture of 2 or more types.

It is preferable that the total amount of such a photoinitiator, a photoinitiation adjuvant, and a sensitizer exists in the range used as 35 mass parts or less with respect to 100 mass parts of said carboxylic acid containing resin (A). When it exceeds 35 mass parts, there exists a tendency for deep-part sclerosis | hardenability to fall by these light absorption.

In order to provide heat resistance, the photosensitive composition of this invention can mix | blend the thermosetting component (D) which has a 2 or more cyclic ether group and / or cyclic thioether group (henceforth cyclic (thio) ether group) in a molecule | numerator. have.

The thermosetting component (D) which has two or more cyclic (thio) ether groups in such a molecule | numerator is a compound which has 2 or more of any one or 2 types of a 3, 4 or 5 membered cyclic ether group or a cyclic thioether group in a molecule | numerator. to be. For example, a compound having at least two or more epoxy groups in a molecule, that is, a polyfunctional epoxy compound (D-1), a compound having at least two or more oxetanyl groups in a molecule, that is, a polyfunctional oxetane compound (D-2) And compounds having two or more thioether groups in the molecule, namely episulfide resin (D-3).

As said polyfunctional epoxy compound (D-1), for example, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1004, and Epiclone 840 by Dainippon Ingyo Kagaku Kogyo Co., Ltd. Epiclone 850, Epiclone 1050, Epiclone 2055, Etoto YD-011, YD-013, YD-127, YD-128 manufactured by Toto Kasei Co., Ltd., DER317, DER331, DER661, manufactured by Dow Chemical Co., Ltd. DER664, Araldite 6071, Araldite 6084, Araldite GY250, Araldite GY260, Sumi-Epoxy ESA-011, ESA-014, ELA-115, made by Sumitomo Chemical Co., Ltd. Bisphenol A type epoxy resins such as ELA-128, AER330, AER331, AER661, and AER664 manufactured by Asahi Kasei Kogyo Co., Ltd .; Epicoat YL903 manufactured by Japan Epoxy Resin Co., Ltd., Epiclone 152, Epiclone 165, manufactured by Dainippon Ingyo Kagaku Kogyo Co., Ltd., Efototo YDB-400, YDB-500, manufactured by Toto Kasei Co., Ltd., DER542, manufactured by Dow Chemical , Brominated epoxy resins such as Araldite 8011 manufactured by Shiba Specialty Chemicals, Sumitomo Kagaku Kogyo Co., Ltd. Sumi-Epoxy ESB-400, ESB-700, Asahi Kasei Kogyo Co., Ltd. AER711, AER714 (all brand names) ; Epicoat 152, Epicoat 154 manufactured by Japan Epoxy Resin Co., Ltd., DEN431, DEN438 manufactured by Dow Chemical Co., Ltd., Epiclone N-730, Epiclone N-770, Epiclone N- 865, EPOTO YDCN-701, YDCN-704, Arodaite ECN1235, Araldite ECN1273, Araldite ECN1299, Araldite XPY307, Nippon Kayaku Co., Ltd. product made by Tohto Kasei Co., Ltd. -201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Kagaku Kogyo Co., Ltd. Sumi-Epoxy ESCN-195X, ESCN-220, Asahi Kasei Kogyo AER Novolak-type epoxy resins such as ECN-235 and ECN-299 (both trade names); Epilon 830 made by Dainippon Ingyo Kagaku Kogyo Co., Ltd., Epicoat 807 made by Japan Epoxy Resin Co., Ltd., Efototo YDF-170, YDF-175, YDF-175, manufactured by Tohto Kasei Co., Ltd. Bisphenol F-type epoxy resins, such as Dit XPY306 (all are brand names); Hydrogenated bisphenol A type epoxy resins such as Efototo ST-2004, ST-2007, ST-3000 (trade name) manufactured by Toto Kasei Co., Ltd .; Epicoat 604, manufactured by Japan Epoxy Resin, Efototo YH-434, manufactured by Toto Kasei Co., Ltd., Araldite MY720, manufactured by Ciba Specialty Chemicals, Sumi-Epoxy ELM-120, manufactured by Sumitomo Chemical Co., Ltd. Glycidylamine-type epoxy resins); Hydantoin type epoxy resins, such as Araldite CY-350 (brand name) by the Ciba Specialty Chemicals company; Alicyclic epoxy resins such as Celoxide 2021 manufactured by Daicel Chemical Industries, Ltd., Araldite CY175, CY179 manufactured by Ciba Specialty Chemicals, Inc. (both trade names); Trihydroxyphenylmethane type epoxy resins such as YL-933 manufactured by Japan Epoxy Resin Co., Ltd., T.E.N., EPPN-501, EPPN-502 manufactured by Dow Chemical Co., Ltd. (both trade names); Bixylenol type or biphenol type epoxy resins, such as YL-6056, YX-4000, and YL-6121 (all are brand names) by the Japan epoxy resin company, or mixtures thereof; Bisphenol S type epoxy resins, such as EBPS-200 by Nippon Kayaku Co., Ltd., EPX-30 by Asahi Denka Kogyo Co., Ltd., and EXA-1514 (brand name) by Dainippon Ingyo Kagaku Kogyo Co., Ltd .; Bisphenol A novolak-type epoxy resins, such as Epicoat 157S (brand name) by the Japan epoxy resin company; Tetraphenylolethane type epoxy resins such as Epicoat YL-931 manufactured by Japan Epoxy Resin Co., Ltd. and Araldite 163 manufactured by Ciba Specialty Chemicals Co., Ltd. (both trade names); Heterocyclic epoxy resins such as Araldite PT810 manufactured by Ciba Specialty Chemicals, TEPIC manufactured by Nissan Chemical Industries, Ltd. (both trade names); Diglycidyl phthalate resins such as Brenmer DGT manufactured by Nippon Yushi Corporation; Tetraglycidyl xylenoylethane resin such as ZX-1063 manufactured by Tohto Kasei Co., Ltd .; Naphthalene group-containing epoxy resins such as ESN-190, ESN-360 manufactured by Shinnitetsu Chemical Co., Ltd., HP-4032, EXA-4750, and EXA-4700 manufactured by Dainippon Ing. Epoxy resins having dicyclopentadiene skeletons such as HP-7200 and HP-7200H manufactured by Dainippon Ing. Glycidyl methacrylate copolymer type epoxy resins such as CP-50S and CP-50M manufactured by Nippon Yushi Co., Ltd .; Furthermore, copolymerization epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; Epoxy-modified polybutadiene rubber derivatives (e.g., PB-3600 manufactured by Daicel Chemical Industries, Ltd.), CTBN-modified epoxy resins (e.g., YR-102, YR-450, manufactured by Tohto Kasei Co., Ltd.), etc. Although it is mentioned, it is not limited to these. These epoxy resins can be used individually or in combination of 2 or more types. Especially among these, a novolak-type epoxy resin, a heterocyclic epoxy resin, a bisphenol-A epoxy resin, or a mixture thereof is 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) methylacrylate, (3-ethyl-3-oxetanyl) methylacrylate, (3-methyl-3-oxetanyl) methylmethacrylate, (3-ethyl-3-oxetanyl) In addition to polyfunctional oxetanes such as methyl methacrylate and oligomers or copolymers thereof, oxetane alcohols and novolac resins, poly (p-hydroxystyrene), cardo-type bisphenols, calix arenes and calyx rezos The etherified substance with resin which has hydroxyl groups, such as lecinarene or silsesquioxane, etc. are mentioned. In addition, the copolymer etc. of the unsaturated monomer which has an oxetane ring, and an alkyl (meth) acrylate are mentioned.

As a compound (D-3) which has two or more cyclic thioether group in the said molecule | numerator, bisphenol-A episulfide resin YL7000 by the Japan epoxy resin company, etc. are mentioned, for example. Moreover, the episulfide resin etc. which substituted the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom can also be used using the same synthesis method.

The compounding amount of the thermosetting component (D) having two or more cyclic (thio) ether groups in the molecule is preferably 0.6 to 2.0 equivalents, more preferably 0.8 to 1.5 equivalents to 1 equivalent of the carboxyl group of the carboxylic acid-containing resin. It is in the range to become. When the compounding quantity of the thermosetting component (D) which has two or more cyclic (thio) ether group in a molecule | numerator is less than 0.6, since a carboxyl group remains in a soldering resist film and heat resistance, alkali resistance, electrical insulation, etc. fall, it is unpreferable. On the other hand, when it exceeds 2.0 equivalent, since the low molecular weight cyclic (thio) ether group remains in a dry coating film, since the intensity | strength of a coating film, etc. fall, it is unpreferable.

When using the thermosetting component (D) which has a 2 or more cyclic (thio) ether group in the said molecule, it is preferable to contain a thermosetting catalyst. As such a thermosetting catalyst, for example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole Imidazole derivatives such as 1-cyanoethyl-2-phenylimidazole and 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; Amines such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine Hydrazine compounds such as compounds, adipic dihydrazide and sebacic acid dihydrazide; As a commercially available thermosetting catalyst, such as phosphorus compounds, such as a triphenylphosphine, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ by the Shikoku Kasei Kogyo Co., Ltd. (all are brand names of an imidazole compound) ), U-CAT3503N, U-CAT3502T (both trade names of block isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, and U-CAT5002 (both bicyclic amidine compounds and salts thereof) produced by acid Aprosa; Can be mentioned. It is not specifically limited to these, What is necessary is just to accelerate the reaction of the thermosetting catalyst of an epoxy resin or an oxetane compound, or an epoxy group and / or an oxetanyl group, and a carboxyl group, and may be used individually or in mixture of 2 or more types none. Also, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-tri Azine, 2-vinyl-4,6-diamino-S-triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct S-triazine derivatives, such as these, can be used, Preferably, the compound which also functions as these adhesive imparting agents is used together with the said thermosetting catalyst.

The compounding quantity of these thermosetting catalysts should just be a normal quantity ratio, for example with respect to 100 mass parts of thermosetting components (D) which have two or more cyclic (thio) ether groups in carboxylic acid containing resin (A) or a molecule | numerator, Preferably it is 0.1-20 mass parts, More preferably, it is 0.5-15.0 mass parts.

The photosensitive composition of this invention can mix | blend a filler as needed in order to raise the physical strength of the coating film, etc. As such a filler, well-known conventional inorganic or organic filler can be used, but especially barium sulfate, spherical silica, and talc are used preferably. Moreover, NANOCRYL (brand name) XP 0396, XP 0596, XP 0733 by Hanse Chemie which disperse | distributed nano silica to the compound which has one or more ethylenically unsaturated groups, or the said polyfunctional epoxy resin (D-1) , XP 0746, XP 0765, XP 0768, XP 0953, XP 0954, XP 1045 (all product class name) or NANOPOX (brand name) XP 0516, XP 0525, XP 0314 (all product class names) Can be used. These may be used alone or in combination of two or more thereof.

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). When the compounding quantity of the said filler exceeds 300 mass parts, since the viscosity of a photosensitive composition becomes high and printability falls or hardened | cured material becomes weak, it is unpreferable.

Moreover, the organic solvent can be used for the photosensitive composition of this invention for the synthesis | combination of the said carboxylic acid containing resin (A), adjustment of a composition, or viscosity adjustment for apply | coating to a board | substrate or a carrier film.

Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, and petroleum solvents. 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 ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether Glycol ethers such as these; Esters such as ethyl acetate, butyl acetate, dipropylene glycol methyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, and propylene glycol butyl ether acetate; Alcohols such as ethanol, propanol, ethylene glycol and propylene glycol; Aliphatic hydrocarbons such as octane and decane; Petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These organic solvents are used alone or as a mixture of two or more thereof.

The photosensitive composition of the present invention may further contain, if necessary, known conventional thermal polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, phenothiazine, finely divided silica, organic bentonite, and montmorillonite. Known conventional thickeners, silicone-based, fluorine-based, antifoaming agents such as polymers and / or leveling agents, silane coupling agents such as imidazole-based, thiazole-based, triazole-based, known conventional additives such as antioxidants and rust inhibitors can do.

On the board | substrate which adjusted the photosensitive composition of this invention to the viscosity suitable for the application | coating method, for example with the said organic solvent, and formed the circuit, the dip coating method, the flow coating method, the roll coating method, the bar coater method, the screen printing method, A non-adhesive coating film can be formed by applying by a method such as a curtain coating method and by volatilizing (temporarily drying) the organic solvent contained in the composition at a temperature of about 60 to 100 ° C. It is preferable that the dry coating film of this photosensitive composition of this invention has a thickness of 15-100 micrometers. Moreover, a dry film can be obtained by apply | coating the photosensitive composition of this invention on a carrier film, and drying. A solder resist film can be formed on the circuit-formed board | substrate by bonding what was wound as a film to the circuit-formed board | substrate, and peeling a carrier film. Then, after drawing a pattern latent image with a direct drawing apparatus (laser direct imaging apparatus), a unexposed part is developed with aqueous alkali solution (for example, 0.3-3% sodium carbonate aqueous solution), and a soldering resist pattern is formed. Moreover, when it contains a thermosetting component, it heats and heats, for example at the temperature of about 140-180 degreeC, and the carboxyl group of the said carboxylic acid containing resin (A), and 2 or more cyclic (thio) ether in a molecule | numerator The cyclic (thio) ether group of the thermosetting component (D) which has a group reacts, and the cured coating film excellent in various characteristics, such as heat resistance, chemical-resistance, hygroscopicity, adhesiveness, and electrical characteristics, can be formed.

As a base material used for the said board | substrate, a high frequency using paper phenol, paper epoxy, glass cloth epoxy, glass polyimide, glass cloth / nonwoven fabric epoxy, glass cloth / paper epoxy, synthetic fiber epoxy, fluorine polyethylene PPO cyanate ester, etc. Copper clad laminates of all grades (such as FR-4), other polyimide films, PET films, glass substrates, ceramic substrates, wafer plates, and the like are used by using materials such as copper clad laminates for circuits.

Volatilization drying after applying the photosensitive composition of this invention is hot-air circulation type drying, IR, hot-plate, a convection oven, etc. (the countercurrent contact of the hot air in a dryer using the thing provided with the heat source of the air heating system by steam) The method and the method of blowing air from a nozzle to a support body can be performed.

As a light source used for the exposure means of the photosensitive composition of this invention, a semiconductor laser or a solid laser can be used. Moreover, although the exposure amount varies with dry film thickness etc. of the photosensitive composition of this invention, it is generally 5-100 mJ / cm <^2> , Preferably 5-60 mJ / cm <^2> , More preferably, 5-30 mJ / cm. It can be in the range of ² . As a direct drawing apparatus, the thing by the pentax company, the Hitachi beer mechanics company, the thing made by the ball semiconductor company, etc. can be used, for example.

Examples of the developing method include an immersion method, a shower method, a spray method, a brush method, and the like. Examples of the developing solution include potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, tetramethylammonium hydroxide, and the like. Alkali aqueous solution can be used.

<Example>

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

<Synthesis of carboxylic acid-containing resin>

In a two-liter separation flask equipped with a stirrer, a thermometer, a reflux cooling tube, a dropping funnel and a nitrogen introduction tube, a cresol novolak 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 were added as a solvent, and it heated and stirred at 90 degreeC, and was made to melt | dissolve. Next, the reaction product 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 to give an acid value of 0.2 mgKOH / g. Got. 241.7 g of tetrahydrophthalic anhydride was put here, it heated at 90 degreeC, and made it react for 6 hours. Thus, a solution of a carboxylic acid-containing resin having a nonvolatile content of 65% by mass, a solid acid value of 77 mgKOH / g, a double bond equivalent (g weight of resin per mole of unsaturated group) of 400 g / equivalent, and a weight average molecular weight of 7,000. Got. Hereinafter, the solution of this carboxylic acid containing resin is called A-1 varnish.

<Preparation of Photosensitive Compositions 1 to 7>

The component shown in following Table 1 was mix | blended and stirred by the quantity (mass part) shown to the said table | surface, and it disperse | distributed with the triaxial roll, and obtained the photosensitive composition, respectively.

The absorbance of the soldering resist film formed using the photosensitive compositions 1-7 was investigated. That is, after apply | coating each photosensitive composition to a glass plate with an applicator, it dried at 80 degreeC for 30 minutes using the hot-air circulation type drying furnace, and the dry coating film was produced on the glass plate. About the dry coating film of each photosensitive composition on this glass plate, it used the ultraviolet visible spectrophotometer (Ubest-V-570DS by the Nippon Bunker Co., Ltd.), and an integrating apparatus (ISN-470 by the Nippon Bunker Co., Ltd.). Absorbance was measured. Moreover, the absorbance 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 dry coating film was computed by subtracting a baseline from the absorbance of the manufactured glass plate with a dry coating film. This operation was performed by changing the coating thickness by an applicator to four steps, the graph of dry coating film thickness and absorbance was created, and the absorbance in 25 micrometers of dry solder resist film thickness was calculated | required from this graph. The results are shown in Table 2 below.

Next, about the photosensitive composition 1, the dry coating film was exposed by the exposure method of Examples 1 and 2 shown in following Table 3, and Comparative Examples 1-4.

Here, in order to investigate the general properties of the solder resist film formed, it tested as follows and evaluated.

(1) surface curability

The copper-clad board | substrate with a copper thickness of 35 micrometers was washed with water after buff roll polishing, and it dried. Then, the photosensitive composition 1 was apply | coated on this board | substrate by the screen printing method, and it dried for 60 minutes in the hot air circulation type drying furnace of 80 degreeC. After drying, it exposed to this dry solder resist coating film by the exposure method of Examples 1 and 2 and Comparative Examples 1-4. The exposure pattern used the front surface exposure pattern. After exposure, development was performed at 30 degreeC for 0.2 second at 0.2 Mpa using the 1 mass% sodium carbonate aqueous solution as a developing solution, and then thermosetting was carried out at 150 degreeC for 60 minutes.

Thus, the surface curability of the obtained cured coating film was evaluated about the glossiness at the incidence angle of 60 degrees using the glossmeter micro trigloss (made by Big Gardner). Evaluation criteria was made glossiness 50 and this value or more was favorable and less than this value was made into defect. The evaluation results are shown in Table 4 below.

(2) hardening depth and cross-sectional shape

The circuit pattern board | substrate whose line / space is 300 micrometers / 300 micrometers width | variety, and copper thickness is 70 micrometers, respectively, was rinsed after buff roll polishing, and it dried and dried. On this circuit pattern board | substrate, the photosensitive composition 1 was apply | coated by the screen printing method, and it dried for 30 minutes in 80 degreeC hot air circulation type drying furnace. After drying, it exposed to this dry coating film using the exposure method of Examples 1 and 2 and Comparative Examples 1-4. The exposure pattern used the pattern which draws the 30/40/50/60/70/80/90/100 micrometer width line in order to the space part mentioned above, respectively. After exposure, the soldering resist pattern was obtained by developing using 1.0 mass part of sodium carbonate aqueous solution. Subsequently, ultraviolet light was irradiated at an exposure dose of 1000 mJ / cm ² using a high pressure mercury lamp, and then thermosetted for 60 minutes. At this time, the minimum line width which remained was made into evaluation of hardening depth.

In addition, evaluation of the cross-sectional shape was performed by observing the cross section of the line part whose design value of the line width of a cured coating film is 100 micrometers. Here, the thickness of the soldering resist film when the copper thickness was 70 micrometers was 65 micrometers. The cross-sectional shape was evaluated in five steps A to E according to the schematic diagram of FIG. 1. In the figure, 1a designates the line width, 1b designates the shape of the solder resist film after exposure and development, and 1c designates the substrate. The state of each evaluation is as follows. In other words,

A evaluation: ideal state of design width,

B evaluation: corrosion of the surface layer due to lack of development resistance,

C rating: undercut state,

D evaluation: line thickening caused by halation or the like,

E Evaluation: Line thickness and undercut of the surface layer occur.

Here, undercut and halation are all terms which show the difference from a design value. Undercut means that especially a lower part becomes thinner than a design value, and halation shows that either or both of an upper part and a lower part become thicker than a design value.

In particular, in the evaluation of A, the difference from the design value was assumed to be within 5 µm in the upper and lower portions of the line.

Not only A evaluation but also C evaluation and D evaluation are levels which can be used as a soldering resist. On the other hand, in the B evaluation and the E evaluation, the lines and the undercut portions are easily peeled off, and it is a level that is difficult to use as the solder resist, and in particular, the E evaluation is unusable.

The evaluation results are shown in Table 4 together.

As apparent from Table 4, when the exposure methods of Examples 1 and 2, which are the exposure methods of the present invention, were used, excellent cross-sectional shape, depth of cure, and surface curability were obtained with a low exposure amount and a short exposure time. On the other hand, when the exposure methods of Comparative Examples 1 to 4 were used, a higher exposure amount and a longer exposure time were required to cure the composition, and the cross sectional shape, curing depth and surface curing properties of the resulting solder resist film were insufficient.

Moreover, the photosensitive compositions 2-7 were also exposed to the dry coating film, and the soldering resist film was formed. In order to investigate the general property of the soldering resist film formed, it tested similarly to the above using the method of Example 1 and 2 as an exposure method, and evaluated. The evaluation result about these and the evaluation result about the compounding example 1 in Table 4 are shown in Table 5 below.

From the result of Table 5, in the soldering resist film formation method of this invention, it exists in the range of 0.6-1.2 in the wavelength range of 355-380 nm per 25 micrometers in thickness of the dry coating film before exposure, and 0.3-0.6 at 405 nm. It turns out that it is more preferable to use the photosensitive compositions (1-5) which show the absorbance in the range of to.

Example 3

The photosensitive composition 1 shown in Table 1 was diluted with methyl ethyl ketone, and it apply | coated on a carrier film, heat-dried for 30 minutes by 80 degreeC hot air dryer, and formed the 25-micrometer-thick photocurable thermosetting resin composition layer, and cover it on The film was bonded together to obtain a dry film. Thereafter, the cover film was peeled off, and the dry film obtained on the patterned copper foil substrate was thermally laminated. Thereafter, exposure was performed under the conditions of Examples 1 and 2 shown in Table 3, and the carrier film was removed, followed by development for 60 seconds with a 1% by weight aqueous sodium carbonate solution to obtain an image. Furthermore, 60 minute heat-hardening was performed by the 150 degreeC hot air dryer, and the test board | substrate was manufactured. About the test board | substrate which has the obtained hardened film, the evaluation test of each characteristic was done by the above-mentioned test method and evaluation method. The result was the same as that of the photosensitive composition 1 of Table 5.

BRIEF DESCRIPTION OF THE DRAWINGS 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 and developing this.

Claims (14)

After applying the photosensitive composition to a substrate and drying, two or more laser lights having different wavelengths are irradiated to the dried coating film to form a pattern latent image irradiated with the two or more laser lights, and then developed by an aqueous alkali solution. A method of forming a solder resist film, characterized by the above-mentioned. After apply | coating a photosensitive composition to a base material and drying, this dry coating film is irradiated with a 1st laser light and the 2nd laser light from a wavelength different from a said 1st laser light, and the said 1st laser light and a 2nd The formation method of the soldering resist film characterized by developing by aqueous alkali solution after forming the pattern latent image irradiated by both of laser beams. The method of forming a solder resist film according to claim 2, wherein one of the first laser light and the second laser light is a blue violet laser light. It is a photosensitive composition used for the formation method of the soldering resist film of Claim 2, The dry coating film before the exposure shows the absorbance of 0.6-1.2 in the wavelength range of 355-380 nm per thickness of 25 micrometers, and also in the wavelength of 405 nm. A photosensitive composition is characterized by showing an absorbance of 0.3 to 0.6. The photosensitive composition according to claim 4, wherein a difference between the maximum absorbance in the wavelength range of 355 to 380 nm and the absorbance in the wavelength of 405 nm is 0.3 or more and less than 0.6 per 25 µm in thickness of the dry coating film before exposure. The said dry coating film before exposure shows the absorbance of 0.6-1.0 at the wavelength of 355 nm, the absorbance of 0.3-0.5 at the wavelength of 405 nm, and also at the wavelength of 355 nm per 25 micrometers. The difference in absorbance and the absorbance at a wavelength of 405 nm is 0.3 or more and less than 0.5, The photosensitive composition characterized by the above-mentioned. The photosensitive composition of Claim 4 in which the said photosensitive composition contains (A) carboxylic acid containing resin, (B) photoinitiator, and (C) pigment. The photopolymerization initiator (B) is an oxime ester photopolymerization initiator having a group represented by the following formula (1), an α-aminoacetophenone photopolymerization initiator having a group represented by the following formula (2), and a formula (3) It is at least 1 type photoinitiator selected from the group which consists of an acyl phosphine oxide type photoinitiator which has a group which becomes a photosensitive composition. <Formula 1>

<Formula 2>

<Formula 3>

(In the meal, 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 (can be substituted with one or more hydroxyl groups, one in the middle of the alkyl chain Or 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 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), an alkyl group having 1 to 20 carbon atoms (can be substituted with one or more hydroxyl groups, and at least one oxygen atom 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 ³ and R ⁴ each independently represent an alkyl group or an arylalkyl group having 1 to 12 carbon atoms, R ⁵ and R ⁶ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cyclic alkylether group having two bonded thereto, R ⁷ and R ⁸ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl group substituted with a halogen atom, an alkyl group or an alkoxy group, provided that One of R ⁷ and R ⁸ may represent an RC (═O) -group, where R is a hydrocarbon group of 1 to 20 carbon atoms The photosensitive composition according to claim 8, wherein the oxime ester photopolymerization initiator having a group represented by Formula 1 includes a compound represented by the following Formula 4. <Formula 4>

The photosensitive composition according to claim 8, wherein the oxime ester photopolymerization initiator having a group represented by Formula 1 includes a compound represented by the following Formula 5. <Formula 5>

(In the meal, 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, and an alkoxycarbonyl group having 2 to 12 carbon atoms (alkoxy When the alkyl group constituting the actual group has 2 or more carbon atoms, the alkyl group may be substituted with one or more hydroxyl groups, may have 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 (can be substituted with one or more hydroxyl groups, and in the middle of the alkyl chain May have one or more oxygen atoms), 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), an alkyl group having 1 to 20 carbon atoms (can be substituted with one or more hydroxyl groups, and at least one in the middle of the alkyl chain May have an oxygen atom), 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) 8. The photosensitive composition as claimed in claim 7, wherein the pigment (C) comprises a phthalocyanine blue pigment. 8. The photosensitive composition according to claim 7, further comprising a thermosetting component (D) having at least two cyclic ether groups and / or cyclic thioether groups in the molecule. The photosensitive composition according to claim 4, which is applied as a dry coating film having a thickness of 15 to 100 mu m. The dry film obtained by drying after apply | coating the photosensitive composition of Claim 4 on a carrier film.

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