KR20200110669A - Film production method and printed wiring board - Google Patents

Abstract

The present invention provides a method for producing a film in which a film of a photosensitive resin composition is exposed to light and then developed to produce a film, in which the shape of the film can have high resolution. The manufacturing method of a film includes forming a coating film from a photosensitive resin composition, irradiating the coating film with light emitted from a light source to expose, and developing the exposed coating film with an alkali solution. The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B), a photoinitiator (C), and an epoxy resin (D). The light irradiated to the coating film includes light of a predetermined wavelength.

Description

Film production method and printed wiring board

The present invention relates to a method for producing a film and a printed wiring board, and more particularly, to a method for producing a film by exposing a coating film containing a photosensitive resin composition, and to a printed wiring board including the film.

Conventionally, various curable resin compositions have been used to form electrically insulating layers such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer of a printed wiring board. In the photosensitive resin composition, the photosensitive resin composition is cured by irradiating light such as ultraviolet rays, and heating as necessary to form an electrically insulating layer.

Japanese Patent Application Publication No. 2008-146044

It is an object of the present invention to provide a method for producing a film in which a film of a photosensitive resin composition is exposed and then developed to produce a film, in which the shape of the film can have high resolution.

Further, another object of the present invention is to provide a printed wiring board comprising a film produced by the above manufacturing method.

A method for producing a film according to an aspect of the present invention includes a step of forming a coating film on the substrate by disposing a photosensitive resin composition on a substrate, and light emitted from a light source to the coating film. And a step of irradiating and exposing, and a step of developing the coated film after the exposure with an alkali solution. The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenically unsaturated bond per molecule, a photoinitiator (C), and an epoxy resin (D). The light absorption spectrum of the photopolymerization initiator (C) has a first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and a second absorption band that is longer than 370 nm and within a wavelength range of 415 nm or less. The light irradiated to the coating film in the exposure step includes first light, second light, and third light. The wavelength range of the first light is within the wavelength range of the first absorption band. The wavelength range of the second light is within the wavelength range of the second absorption band. The wavelength range of the third light is within a wavelength range of 305 nm or more and 325 nm or less. The curve of the area under the curve in the wavelength range of 200 nm to 500 nm in the spectrum of the light irradiated to the coating film, the area under the curve of the wavelength range shorter than 280 nm and up to 200 nm and the wavelength range longer than 415 nm and up to 500 nm The percentage of the total of the lower surface area is 5% or less.

A printed wiring board according to an aspect of the present invention includes a conductive layer and an insulating layer overlapping the conductive layer. The insulating layer includes a film produced by the method for producing the film.

1 is a diagram showing a spectrum of light emitted from an ultra-high pressure mercury lamp of a light source in an example.
FIG. 2A is a diagram showing an example of the shape of a film when the exposure condition is condition A in the Examples, and FIG. 2B is a film when the exposure condition is condition C. It is a figure which shows an example of the shape of, and FIG. 2C is a figure which shows an example of the shape of a film when the exposure condition is set to condition D.
3A to 3E are cross-sectional views showing a step of manufacturing a multilayer printed wiring board according to an embodiment of the present invention.

First, the process of reaching the present invention will be described.

In producing an electrically insulating layer from a photosensitive resin composition, for example, in Patent Document 1 (Japanese Patent Publication No. 2008-146044), a pattern by a direct drawing method (direct drawing method) using ultraviolet rays A photosensitive resin composition has been proposed in which a latent image is formed and the patterned latent image is developed with an aqueous alkali solution. When irradiating the dry coating film of this photosensitive resin composition with light in a wavelength range of 355 to 375 nm and light in a wavelength of 405 nm, the photosensitive resin composition is highly sensitive to the wavelength range and wavelength, and exposure by direct drawing Even if it is, a thick electrical insulating layer or the like can be produced.

In Patent Document 1, a layer formed of a photosensitive resin composition is excellent in properties such as insulation, acid/alkali resistance, and plating resistance required for an insulating layer.

However, when a film of such a photosensitive resin composition is exposed and then developed to produce a film, it is not easy for the film to have high resolution. Therefore, for example, in the case of producing a film having holes, there is a problem that it is difficult to make the shape of the holes clear.

In view of these points, the inventors have conducted intensive research, as a result of exposing the coating film of the photosensitive resin composition and then developing it to produce a film, a method for producing a film in which the shape of the film can have high resolution, and the above The invention regarding a printed wiring board including a film has been completed.

Hereinafter, the photosensitive resin composition in this embodiment is demonstrated.

The photosensitive resin composition of this embodiment contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenic unsaturated bond per molecule, a photoinitiator (C), and an epoxy resin (D). . In addition, the details of each component of the photosensitive resin composition will be described later.

In the present embodiment, the light absorption spectrum of the photopolymerization initiator (C) has a first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and a second absorption band that is longer than 370 nm and within a wavelength range of 415 nm or less. The first absorption band may be in the entire wavelength range of 350 nm or more and 370 nm or less, or may be partially in the wavelength range of 350 nm or more and 370 nm or less. Moreover, the 1st absorption band may be continuous with another absorption band which is less than 350 nm, and may be continuous with another absorption band which is more than 370 nm. The second absorption band (absorption band longer than 370 nm and within a wavelength range of 415 nm or less) and a third absorption band (absorption band within a wavelength range of 305 nm or more and 325 nm or less) to be described later are also the same.

In this embodiment, by disposing the photosensitive resin composition on the substrate, a coating film can be formed on the substrate, the coating film is irradiated with light to expose, and the exposed coating film is developed with an alkali solution to form a film. Specifically, the method of manufacturing a film containing the photosensitive resin composition includes a step of forming a coating film on the substrate by disposing the photosensitive resin composition on the substrate, and a step of irradiating the coating film with light emitted from a light source to expose And, a step of developing the coating film after exposure with an alkali solution. The spectrum of light irradiated to the coating film in the exposure process is the first intensity distribution overlapping within the wavelength range of 350 nm to 370 nm with the first absorption band, and the wavelength range of 415 nm or less with the second absorption band longer than 370 nm. It has a second intensity distribution overlapping at and a third intensity distribution within a wavelength range of 305 nm or more and 325 nm or less. And, the intensity here means intensity of a value greater than 0. That is, the light irradiated to the coating film in the exposure process includes the first light, the second light, and the third light, and the wavelength range of the first light is within the wavelength range of the first absorption band, and the second The wavelength range of light is within the wavelength range of the second absorption band, and the wavelength range of third light is within the wavelength range of 305 nm or more and 325 nm or less. In addition, in this light spectrum, if the curve of the area under the curve of the wavelength range shorter than 280 nm and up to 200 nm and the wavelength range longer than 415 nm and up to 500 nm for the area under the curve in the wavelength range of 200 nm to 500 nm, The percentage of the total of the enemy is 5% or less. Therefore, when a coating film formed of a photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film has high resolution. When this film has pores, the pore shape of the film can be clearly formed. In addition, the "wavelength range" of the first light, the second light, and the third light includes a case of a single wavelength such as a laser made of monochromatic light.

When a coating film of a photosensitive resin composition is exposed and then developed to produce a coating film, it is assumed that the shape of the coating film has a high resolution property for the following reasons.

In this embodiment, as described above, the photopolymerization initiator (C) has a first absorption band in which the absorption spectrum of light is within a wavelength range of 350 nm to 370 nm, and the light irradiated to the coating film includes the first light. , The wavelength range of this first light is within the wavelength range of the first absorption band. The first light includes a wavelength of the first absorption and a wavelength overlapping within a wavelength range of 350 nm or more and 370 nm or less. Therefore, in the coating film, the photopolymerization initiator (C) can absorb light in the wavelength range of 350 nm or more and 370 nm or less to initiate a photopolymerization reaction. Thereby, the photoinitiator (C) is efficiently activated by the light irradiated to the coating film, and it becomes easy to accelerate the reaction of the photosensitive resin composition as a whole. Therefore, it is considered that light having a wavelength of 350 nm or more and 370 nm or less contributes to the reactivity of the photosensitive resin composition as a whole and can improve the reactivity of the photosensitive resin composition. In one aspect of the present embodiment, the light irradiated to the coating film contains i-rays with a wavelength of 365 nm, and the first intensity distribution has an intensity at a wavelength of 365 nm. That is, the first light may include light having a wavelength of 365 nm.

In addition, as described above, the light absorption spectrum of the photopolymerization initiator (C) is longer than 370 nm and has a second absorption band within a wavelength range of 415 nm or less, and the light irradiated to the coating film contains the second light. The wavelength range of the second light is within the wavelength range of the second absorption band. The second light includes a wavelength of the second absorption and a wavelength longer than 370 nm and overlapping within a wavelength range of 415 nm or less. Therefore, in the coating film, the photopolymerization initiator (C) absorbs light in the wavelength range of longer than 370 nm and less than 415 nm, and can initiate a photopolymerization reaction. Therefore, it is considered that good curability can be achieved, particularly in the deep portion of the coating film of the photosensitive resin composition. Further, the photopolymerization initiator (C) can exhibit a photobleaching effect by absorbing light having a wavelength of 350 nm or more and 370 nm or less as described above. That is, it can act to improve the transmittance of light having a wavelength effective for deep curing. Thereby, it is considered that the deep curing property of the coating film of the photosensitive resin composition can be improved.

In particular, it is preferable that the second absorption band includes at least absorption in the wavelength range of longer than 400 nm and of 415 nm or less, and that the second light includes at least light in the wavelength range of longer than 400 nm and of 415 nm or less. In this case, in the coating film, the photopolymerization initiator (C) absorbs light in a wavelength range of longer than 400 nm and less than 415 nm to initiate a photopolymerization reaction. Thereby, in the deep part of the coating film of the photosensitive resin composition, it is possible to realize more favorable curability.

Further, the light irradiated to the coating film of the photosensitive resin composition has a third intensity distribution within a wavelength range of 305 nm or more and 325 nm or less. That is, the light irradiated to the coating film of the photosensitive resin composition includes the third light, and the wavelength range of the third light is in a wavelength range of 305 nm or more and 325 nm or less. Therefore, it is thought that the surface curing property of the coating film of the photosensitive resin composition can be improved. It is considered that this is because the carboxyl group-containing resin (A) in the photosensitive resin composition absorbs light in a wavelength range of 305 nm or more and 325 nm or less to initiate a photopolymerization reaction by a photosensitizing effect or the like. In addition, light having a wavelength of 305 nm or more and 325 nm or less is naturally easily scattered in the coating film, but since this light is absorbed by the carboxyl group-containing resin (A) as described above, scattering of light in the coating film is difficult to occur. Therefore, it is thought that it becomes difficult to decrease the resolution.

In particular, the photopolymerization initiator (C) further has a third absorption band in which the absorption spectrum of light is in a wavelength range of 305 nm or more and 325 nm or less, and at least light in which the third light is in a wavelength range of 305 nm or more and 325 nm or less. When included, that is, when the wavelength range of the third light is within the wavelength range of the third absorption band, the photopolymerization initiator (C) can initiate a photopolymerization reaction by absorbing light having a wavelength of 305 nm or more and 325 nm or less. Therefore, it is easy to particularly increase the surface hardenability of the coating film. In addition, since scattering of light having a wavelength of 305 nm or more and 325 nm or less is difficult to occur in the coating film as described above, a decrease in resolution due to the photopolymerization initiator (C) is more difficult to occur.

Further, as described above, in the spectrum of light irradiated to the coating film, the area under the curve in the wavelength range shorter than 280 nm and up to 200 nm for the area under the curve in the wavelength range of 200 nm to 500 nm and longer than 415 nm, 500 The percentage of the sum of the areas under the curve in the wavelength range up to nm is 5% or less. Therefore, it is possible to suppress scattering of light in this wavelength range in the coating film of the photosensitive resin composition. Thereby, in the coating film of the photosensitive resin composition, it can make it difficult to generate|occur|produce the fall of resolution by light scattering. Therefore, for example, in the case of producing a film having pores from a photosensitive resin composition by a photolithography method, it is possible to make it difficult to adversely affect the shape of the pores.

As described above, in this embodiment, when the coating film of the photosensitive resin composition is exposed, light of a specific wavelength is irradiated, and it is difficult to irradiate light of a wavelength unnecessary for reaction or curing, so that the shape of the film of the photosensitive resin composition is high resolution. Can have

Components constituting the photosensitive resin composition according to the present embodiment will be described in detail. And in the following description, "(meth)acryl" means at least one of "acrylic" and "methacryl". For example, (meth)acrylate means at least one of acrylate and methacrylate.

It is preferable that the carboxyl group-containing resin (A) contains a carboxyl group-containing resin having an ethylenically unsaturated group. In this case, the carboxyl group-containing resin (A) has photoreactivity. Therefore, the carboxyl group-containing resin (A), together with the unsaturated compound (B), can impart photosensitivity, specifically, ultraviolet curing properties, to the photosensitive resin composition.

It is preferable that the carboxyl group-containing resin (A) contains a carboxyl group-containing resin having an aromatic ring. In this case, high heat resistance and insulation reliability can be imparted to the cured product of the photosensitive resin composition. In addition, due to the aromatic ring, since the absorption spectrum of light of the carboxyl group-containing resin (A) can have absorption within a wavelength range of 305 nm or more and 325 nm or less, scattering of light in the coating film is particularly difficult to occur during exposure. , The resolution is particularly improved.

It is more preferable that the carboxyl group-containing resin (A) contains a carboxyl group-containing resin having a polycyclic aromatic ring of any one of a biphenyl skeleton, a naphthalene skeleton, a fluorene skeleton, and an anthracene skeleton. When the carboxyl group-containing resin (A) contains a polycyclic aromatic ring of any one of a biphenyl skeleton, naphthalene skeleton, fluorene skeleton, and anthracene skeleton, it is possible to impart higher heat resistance and insulation reliability to the cured product of the photosensitive resin composition. have. Further, in this case, the absorption spectrum of light of the carboxyl group-containing resin (A) can have a particularly large absorption within a wavelength range of 305 nm or more and 325 nm or less, so that scattering of light during exposure can be more difficult to occur, and resolution The sex is particularly improved. It is more preferable that the carboxyl group-containing resin (A) contains a carboxyl group-containing resin (A1) having a bisphenol fluorene skeleton. In this case, due to the bisphenol fluorene skeleton, the absorption spectrum of light of the carboxyl group-containing resin (A1) can have a particularly large absorption within the wavelength range of 305 nm or more and 325 nm or less, making it particularly difficult to generate light scattering during exposure. Can be made, and it is possible to make it more difficult to cause a decrease in resolution. Thereby, when the coating film of the photosensitive resin composition is exposed and then developed to produce a film, the shape of the film can have higher resolution. Therefore, for example, in the case of producing a film having pores from a photosensitive resin composition by a photolithography method, it is possible to make it difficult to give a bad influence to the shape of the pores. Further, in this case, higher heat resistance and insulation reliability can be imparted to the cured product of the photosensitive resin composition.

The carboxyl group-containing resin (A1) having a bisphenol fluorene skeleton includes, for example, an epoxy compound (a1) having a bisphenol fluorene skeleton represented by the following formula (1) and an unsaturated group-containing carboxylic acid (a2-1). It includes an intermediate that is a reactant of the carboxylic acid (a2) and the reactant of an acid anhydride (a3). In the formula (1), R ₁ to R ₈ are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, or a halogen. The carboxyl group-containing resin (A1) is a carboxylic acid (a2) containing an epoxy compound (a1) having a bisphenol fluorene skeleton (S1) represented by the following formula (1) and an unsaturated group-containing carboxylic acid (a2-1) It is synthesized by reacting and reacting the resulting intermediate with an acid anhydride (a3).

Each of R ₁ to R ₈ in formula (1) may be hydrogen, but may be an alkyl group having 1 to 5 carbon atoms or a halogen. Because, even if hydrogen in the aromatic ring is substituted with a low molecular weight alkyl group or halogen, there is no adverse effect on the physical properties of the carboxyl group-containing resin (A1). This is because there are cases where this is improved.

If the carboxyl group-containing resin (A1) has a bisphenol fluorene skeleton derived from the epoxy compound (a1), it is possible to impart high heat resistance and insulation reliability to the cured product of the photosensitive resin composition containing the carboxyl group-containing resin (A1).

The carboxyl group-containing resin (A1) will be described more specifically. In order to synthesize the carboxyl group-containing resin (A1), first, at least a part of the epoxy group in the epoxy compound (a1) having a bisphenol fluorene skeleton represented by formula (1) and an unsaturated group-containing carboxylic acid (a2-1) are included. The intermediate is synthesized by reacting the carboxylic acid (a2). The synthesis of the intermediate is defined as the first reaction. The intermediate has a secondary hydroxyl group generated by the ring-opening addition reaction of a carboxylic acid (a2) containing an epoxy group and an unsaturated group-containing carboxylic acid (a2-1). Next, the acid anhydride (a3) is reacted with a secondary hydroxyl group in the intermediate. Thereby, a carboxyl group-containing resin (A1) can be synthesized. The reaction of the intermediate and acid anhydride (a3) is defined as the second reaction. The acid anhydride (a3) may include an acid anhydride and an acid dianhydride. An acid anhydride is a compound having one acid anhydride group in which two carboxyl groups in one molecule are dehydrated and condensed. An acid dianhydride is a compound having two acid anhydride groups in which four carboxyl groups in one molecule are dehydrated and condensed.

The carboxyl group-containing resin (A1) may contain an unreacted component in the intermediate. In addition, when the acid anhydride (a3) contains an acid anhydride and an acid dianhydride, the carboxyl group-containing resin (A1) is a component in the intermediate and a component in the intermediate as well as the reaction product of the component in the acid dianhydride and the component in the acid dianhydride. Any one or both of the reactant of the component in the intermediate and the reactant of the component in the intermediate and the component in the acid dianhydride may be contained. That is, the carboxyl group-containing resin (A1) may be a mixture containing a plurality of different compounds having the same structure as these.

The carboxyl group-containing resin (A1) has photoreactivity by having an ethylenically unsaturated group derived from the unsaturated group-containing carboxylic acid (a2-1). Therefore, the carboxyl group-containing resin (A1) can impart photosensitivity, specifically, ultraviolet curing properties, to the photosensitive resin composition. In addition, since the carboxyl group-containing resin (A1) has a carboxyl group derived from the acid anhydride (a3), the photosensitive resin composition can be given developability by an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide. have.

It is preferable that the weight average molecular weight of the carboxyl group-containing resin (A1) is in the range of 700 or more and 10000 or less. When the weight average molecular weight is 700 or more, the insulating properties of the cured product of the photosensitive resin composition can be improved, and the dielectric loss tangent can be reduced. In addition, when the weight average molecular weight is 10000 or less, developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved. As for the weight average molecular weight, it is more preferable that it is 900 or more, and it is especially preferable that it is 1000 or more. In addition, the weight average molecular weight is more preferably in the range of 8000 or less, and particularly preferably in the range of 5000 or less.

It is preferable that the polydispersity of the carboxyl group-containing resin (A1) is in the range of 1.0 or more and 4.8 or less. In this case, it is possible to impart excellent developability to the photosensitive resin composition while ensuring good insulation of the cured product formed from the photosensitive resin composition. The polydispersity of the carboxyl group-containing resin (A1) is more preferably 1.1 or more and 4.0 or less, and still more preferably 1.2 or more and 2.8 or less.

The number average molecular weight and molecular weight distribution of the carboxyl group-containing resin (A1) as described above is that the carboxyl group-containing resin (A1) is an unreacted component in an intermediate, a component in an intermediate and a component in an acid dianhydride and a reaction product of a component in an acid dianhydride, an intermediate. This can be achieved by being a mixture suitably containing various components, such as a reaction product of a component in a component and a component in an acid dianhydride, and a reaction product of a component in an intermediate and a component in an acid dianhydride. More specifically, it can be achieved by controlling parameters such as the average molecular weight of the epoxy compound (a1), the amount of the acid monohydride relative to the epoxy compound (a1), and the amount of the acid dianhydride relative to the epoxy compound (a1).

In addition, the polydispersity is a value (Mw/Mn) of the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the carboxyl group-containing resin (A1).

The solid dispersion value of the carboxyl group-containing resin (A1) is preferably in the range of 60 mgKOH/g or more and 140 mgKOH/g or less. In this case, developability of the photosensitive resin composition is particularly improved. It is more preferable that the acid value is in the range of 80 mgKOH/g or more and 135 mgKOH/g or less, and even more preferably in the range of 90 mgKOH/g or more and 130 mgKOH/g or less.

The molecular weight of the carboxyl group-containing resin (A1) can be adjusted by crosslinking the acid dianhydride. In this case, a carboxyl group-containing resin (A1) in which the acid value and molecular weight were adjusted is obtained. That is, by controlling the amount of the acid dianhydride contained in the acid anhydride (a3), the molecular weight and acid value of the carboxyl group-containing resin (A1) can be easily adjusted. And the molecular weight of the carboxyl group-containing resin (A1) is calculated from the measurement result under the following conditions by gel permeation and chromatography.

GPC device: SHODEX SYSTEM 11 manufactured by Showa Denko

Column: 4 serial to SHODEX KF-800P, KF-005, KF-003, KF-001

Mobile phase: THF

Flow: 1 ml/min

Column temperature: 45°C

Detector: RI

Conversion: Polystyrene

The raw materials of the carboxyl group-containing resin (A1) and reaction conditions at the time of synthesis of the carboxyl group-containing resin (A1) will be described in detail.

The epoxy compound (a1) has a structure represented by the following formula (2), for example. N in Formula (2) is an integer in the range of 0-20, for example. In order to properly control the molecular weight of the carboxyl group-containing resin (A1), the average of n is particularly preferably in the range of 0 to 1. When the average of n is in the range of 0 to 1, even when the acid anhydride (a3) contains an acid dianhydride, an excessive increase in molecular weight is easily suppressed.

The carboxylic acid (a2) contains an unsaturated group-containing carboxylic acid (a2-1). The carboxylic acid (a2) may contain only an unsaturated group-containing carboxylic acid (a2-1). Alternatively, the carboxylic acid (a2) may contain carboxylic acids other than the unsaturated group-containing carboxylic acid (a2-1) and the unsaturated group-containing carboxylic acid (a2-1).

The unsaturated group-containing carboxylic acid (a2-1) may contain, for example, a compound having only one ethylenically unsaturated group. More specifically, the unsaturated group-containing carboxylic acid (a2-1) is, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, crotonic acid, cinnamic acid, and 2-acrylic acid. Royloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 2-acryloyloxyethylphthalic acid, 2-methacryloyloxyethylphthalic acid, 2-acryloyloxypropylphthalic acid, 2-methacryloyl Oxypropylphthalic acid, 2-acryloyloxyethylmaleic acid, 2-methacryloyloxyethylmaleic acid, β-carboxyethylacrylate, 2-acryloyloxyethyltetrahydrophthalic acid, 2-methacryloyloxy It may contain at least one compound selected from the group consisting of ethyl tetrahydrophthalic acid, 2-acryloyloxyethylhexahydrophthalic acid, and 2-methacryloyloxyethylhexahydrophthalic acid. Preferably, the unsaturated group-containing carboxylic acid (a2-1) contains acrylic acid.

The carboxylic acid (a2) may contain a polybasic acid (a2-2). The polybasic acid (a2-2) is an acid in which two or more hydrogen atoms can be substituted with metal atoms in one molecule. It is preferable that the polybasic acid (a2-2) has two or more carboxyl groups. In this case, the epoxy compound (a1) reacts with both of the unsaturated group-containing carboxylic acid (a2-1) and the polybasic acid (a2-2). When the polybasic acid (a2-1) crosslinks the epoxy group present in the two molecules of the epoxy compound (a1), an increase in molecular weight is obtained. Thereby, the insulating properties of the cured product of the photosensitive resin composition can be improved, and the dielectric loss tangent can be reduced.

It is preferable that the polybasic acid (a2-2) contains a dicarboxylic acid. Polybasic acid (a2-2) is, for example, 4-cyclohexene-1,2-dicarboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid , Sebacic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid may contain one or more compounds selected from the group consisting of. Preferably, the polybasic acid (a2-2) contains 4-cyclohexene-1,2-dicarboxylic acid.

In making the epoxy compound (a1) and the carboxylic acid (a2) react, an appropriate method can be employed. For example, a reactive solution is obtained by adding carboxylic acid (a2) to the solvent solution of the epoxy compound (a1), further adding a thermal polymerization inhibitor and a catalyst as necessary, and mixing with stirring. An intermediate can be obtained by reacting this reactive solution at a temperature of preferably 60°C to 150°C, particularly preferably 80°C to 120°C by a conventional method. Solvents are, for example, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, and ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl It may contain at least one component selected from the group consisting of acetic acid esters such as carbitol acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and dialkyl glycol ethers. The thermal polymerization inhibitor contains at least one of hydroquinone and hydroquinone monomethyl ether, for example. The catalyst is composed of, for example, tertiary amines such as benzyldimethylamine and triethylamine, quaternary ammonium salts such as trimethylbenzyl ammonium chloride and methyltriethylammonium chloride, triphenylphosphine, and triphenylstyrene. It may contain at least one component selected from the group.

It is particularly preferred that the catalyst contains triphenylphosphine. That is, it is preferable to react the epoxy compound (a1) and the carboxylic acid (a2) in the presence of triphenylphosphine. In this case, the ring-opening addition reaction of the epoxy group and the carboxylic acid (a2) in the epoxy compound (a1) is particularly promoted, and it is possible to achieve a reaction rate (conversion rate) of 95% or more, or 97% or more, or approximately 100%. . Further, generation of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulating property of the layer containing the cured product is improved.

When the epoxy compound (a1) and the carboxylic acid (a2) are reacted, the amount of the carboxylic acid (a2) per 1 mole of the epoxy group of the epoxy compound (a1) is preferably in the range of 0.5 moles or more and 1.2 moles or less. In this case, the photosensitive resin composition has excellent photosensitivity and stability. From the same viewpoint, it is preferable that the amount of the unsaturated group-containing carboxylic acid (a2-1) per 1 mole of the epoxy group of the epoxy compound (a1) is in the range of 0.5 moles or more and 1.2 moles or less. Alternatively, when the carboxylic acid (a2) contains a carboxylic acid other than the unsaturated group-containing carboxylic acid (a2-1), the unsaturated group-containing carboxylic acid (a2-1) per 1 mol of the epoxy group of the epoxy compound (a1) The amount of may be in the range of 0.5 mol or more and 0.95 mol or less. In addition, when the carboxylic acid (a2) contains a polybasic acid (a2-2), the amount of the polybasic acid (a2-2) per 1 mol of the epoxy group of the epoxy compound (a1) is preferably in the range of 0.025 mol or more and 0.25 mol or less. Do. In this case, the photosensitive resin composition has excellent photosensitivity and stability.

It is also preferable to make the epoxy compound (a1) and carboxylic acid (a2) react under air bubbling. In this case, the addition polymerization reaction of the unsaturated group can be suppressed, thereby increasing the molecular weight of the intermediate and suppressing the solution gelation of the intermediate. In addition, the carboxyl group-containing resin (A1) as the final product can suppress excessive coloring.

The intermediate body thus obtained contains a hydroxyl group produced by reacting the epoxy group in the epoxy compound (a1) with the carboxyl group in the carboxylic acid (a2).

It is preferable that the acid anhydride (a3) contains an acid anhydride. An acid anhydride is a compound having one acid anhydride group.

The acid anhydride may contain an anhydride of a dicarboxylic acid. The acid anhydride is, for example, 1,2,3,6-tetrahydrophthalic anhydride, phthalic anhydride, succinic anhydride, methyl succinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride, methyltetra At least one compound selected from the group consisting of hydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride, and methylhexahydrophthalic anhydride It may contain. In particular, it is preferable that the acid anhydride contains 1,2,3,6-tetrahydrophthalic anhydride. In this case, the photosensitive resin composition can improve the insulating properties of the cured product of the photosensitive resin composition while ensuring good developability. With respect to the whole acid anhydride, 1,2,3,6-tetrahydrophthalic anhydride is preferably in the range of 20 mol% or more and 100 mol% or less, more preferably 40 mol% or more and 100 mol% or less, It is not limited to this.

It is preferable that the acid anhydride (a3) contains an acid dianhydride. An acid dianhydride is a compound having two acid anhydride groups. The acid dianhydride may contain an anhydride of tetracarboxylic acid. The acid dianhydride is, for example, 1,2,4,5-benzenetetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, methylcyclohexene tetracarboxylic dianhydride, tetracarboxylic dianhydride, naphthalene-1,4 ,5,8-tetracarboxylic dianhydride, ethylene tetracarboxylic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, glycerinbisanehydrotrimellitate monoacetate, ethylene glycol Bisanehydrotrimelitate, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5 (tetrahydro-2,5- Dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, 1,2,3,4-butanetetracarboxylic dianhydride and 3,3',4,4'- It may contain at least one compound selected from the group consisting of biphenyltetracarboxylic dianhydride. It is preferable that the acid dianhydride contains an acid dianhydride having an aromatic ring. In particular, it is preferable that the acid dianhydride contains 3,3',4,4'-biphenyltetracarboxylic dianhydride. In this case, the photosensitive resin composition can improve the insulating properties of the cured product of the photosensitive resin composition while ensuring good developability. In addition, the transparency of the photosensitive resin composition is improved, and the resolution is thereby improved. With respect to the entire acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride is preferably in the range of 20 mol% or more and 100 mol% or less, and 40 mol% or more and 100 mol% or less. Although it is more preferable, it is not limited to this.

In reacting the intermediate and the acid anhydride (a3), an appropriate method may be employed. For example, an acid anhydride (a3) is added to the solvent solution of an intermediate, and if necessary, a thermal polymerization inhibitor and a catalyst are further added and mixed with stirring to obtain a reactive solution. Carboxyl group-containing resin (A1) can be obtained by reacting this reactive solution at a temperature of preferably 60°C or more and 150°C or less, and particularly preferably 80°C or more and 120°C or less by a conventional method. Suitable solvents, catalysts and polymerization inhibitors may be used, and solvents, catalysts and polymerization inhibitors used in the synthesis of the intermediate may be used as they are.

It is particularly preferred that the catalyst contains triphenylphosphine. That is, it is preferable to react the intermediate and the acid anhydride (a3) in the presence of triphenylphosphine. In this case, the reaction between the secondary hydroxyl group and the acid anhydride (a3) in the intermediate is particularly promoted, and a reaction rate (conversion rate) of 90% or more, 95% or more, 97% or more, or approximately 100% can be achieved. In addition, the occurrence of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulating property of the layer containing the cured product is further improved.

It is also preferable to react the intermediate and the acid anhydride (a3) under air bubbling. In this case, an excessive increase in molecular weight of the resulting carboxyl group-containing resin (A1) is suppressed, and thus developability of the photosensitive resin composition with an alkaline aqueous solution is particularly improved.

The carboxyl group-containing resin (A) may contain a carboxyl group-containing resin that has an aromatic ring and does not have photopolymerization. The carboxyl group-containing resin which has an aromatic ring and does not have photopolymerization contains, for example, a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group. Ethylenically unsaturated compounds having a carboxyl group include acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, 2-(meth)acryloyloxyethylphthalate, and 2-(meth)acrylo. Compounds, such as monooxyethyl-2-hydroxyethylphthalate, may be contained. The ethylenically unsaturated compound having a carboxyl group may also contain a reactant of a dibasic acid anhydride, such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group, such as a (meth)acrylic acid ester of a linear or branched aliphatic or alicyclic (however, it may have some unsaturated bonds in the ring).

The carboxyl group-containing resin (A) may contain a resin other than the carboxyl group-containing resin (A1), that is, a carboxyl group-containing resin (hereinafter also referred to as a carboxyl group-containing resin (A2)) that does not have a bisphenol fluorene skeleton.

The carboxyl group-containing resin (A2) may contain, for example, a compound having a carboxyl group and not having photopolymerization (hereinafter referred to as component (A2-1)). The component (A2-1) contains, for example, a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group. The ethylenically unsaturated compound having a carboxyl group may contain compounds such as acrylic acid, methacrylic acid, and ω-carboxy-polycaprolactone (n≒2) monoacrylate. The ethylenically unsaturated compound having a carboxyl group may also contain a reactant of a dibasic acid anhydride, such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like. The ethylenically unsaturated monomer is 2-(meth)acryloyloxyethylphthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethylphthalate, a linear or branched aliphatic or alicyclic (however, some You may further contain ethylenically unsaturated compounds which do not have a carboxyl group, such as (meth)acrylic acid ester of (may have an unsaturated bond).

The carboxyl group-containing resin (A2) may contain a compound having a carboxyl group and an ethylenically unsaturated group (hereinafter referred to as component (A2-2)). In addition, the carboxyl group-containing resin (A2) may contain only the component (A2-2). The component (A2-2) is selected from the group of, for example, an intermediate which is a reaction product of an epoxy compound (x1) having two or more epoxy groups in one molecule and an ethylenically unsaturated compound (x2), and a polyvalent carboxylic acid and anhydride thereof. It contains a resin (referred to as first resin (x)) that is a reactant of at least one compound (x3). The first resin (x) can be obtained, for example, by adding the compound (x3) to an intermediate obtained by reacting an epoxy group in the epoxy compound (x1) with a carboxyl group in the ethylenically unsaturated compound (x2). The epoxy compound (x1) may contain an appropriate epoxy compound such as a cresol novolak type epoxy compound, a phenol novolak type epoxy compound, and a biphenyl novolak type epoxy compound. In particular, it is preferable that the epoxy compound (x1) contains at least one compound selected from the group of a biphenyl novolak type epoxy compound and a cresol novolak type epoxy compound. The epoxy compound (x1) may contain only a biphenyl novolak type epoxy compound, or may contain only a cresol novolak type epoxy compound. In this case, since the aromatic ring is contained in the main chain of the epoxy compound (x1), the degree to which the cured product of the photosensitive resin composition is significantly corroded by an oxidizing agent containing potassium permanganate or the like can be reduced. The epoxy compound (x1) may contain a polymer of the ethylenically unsaturated compound (z). The ethylenically unsaturated compound (z) contains a compound (z1) having an epoxy group such as glycidyl (meth)acrylate, or does not have an epoxy group such as 2-(meth)acryloyloxyethylphthalate. It further contains a compound (z2) that is not. It is preferable that the ethylenically unsaturated compound (x2) contains at least one of acrylic acid and methacrylic acid. Compound (x3) contains, for example, one or more compounds selected from the group consisting of polycarboxylic acids such as phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid, and anhydrides of these polycarboxylic acids. In particular, it is preferable that the compound (x3) contains at least one polyvalent carboxylic acid selected from the group of phthalic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid.

The component (A2-2) may contain a resin (referred to as the second resin (y)) which is a reaction product of a polymer of an ethylenically unsaturated monomer containing an ethylenically unsaturated compound having a carboxyl group and an ethylenically unsaturated compound having an epoxy group. . The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. The second resin (y) is obtained by reacting an ethylenically unsaturated compound having an epoxy group with a part of the carboxyl groups in the polymer. The ethylenically unsaturated monomer may further contain an ethylenically unsaturated compound having no carboxyl group. Ethylenically unsaturated compounds having a carboxyl group include, for example, acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone (n≒2) monoacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, and the like. Contains compounds. Ethylenically unsaturated compounds having no carboxyl group are, for example, 2-(meth)acryloyloxyethylphthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethylphthalate, linear or branched aliphatic or alicyclic It contains compounds such as (meth)acrylic acid ester of a group (however, it may have some unsaturated bonds in the ring). It is preferable that the ethylenically unsaturated compound having an epoxy group contains glycidyl (meth)acrylate.

The carboxyl group-containing resin (A) contains only a carboxyl group-containing resin (A1), only a carboxyl group-containing resin (A2), or a carboxyl group-containing resin (A1) and a carboxyl group-containing resin (A2). In order to obtain high transparency of the photosensitive resin composition and to reduce the dielectric loss tangent of the cured product of the photosensitive resin composition, the carboxyl group-containing resin (A) preferably contains 30% by mass or more of the carboxyl group-containing resin (A1), 60 It is more preferable to contain it by mass% or more, and it is still more preferable to contain 100 mass %.

The content of the carboxyl group-containing resin (A) is preferably 5% by mass or more and 85% by mass or less, more preferably 10% by mass or more and 75% by mass or less based on the solid content of the photosensitive resin composition, and 26 It is more preferable to exist in the range of mass% or more and 60 mass% or less, and it is especially preferable to exist in the range of 30 mass% or more and 45 mass% or less. And the solid content means the total amount of all components excluding volatile components such as a solvent from the photosensitive resin composition.

It is preferable that the solid dispersion value of the carboxyl group-containing resin (A) is in the range of 40 mgKOH/g or more and 160 mgKOH/g or less. In this case, the stability of the photosensitive resin composition is particularly improved. If the acid value is in the range of 60 mgKOH/g or more and 140 mgKOH/g or less, it is more preferable, and the acid value is more preferably in the range of 80 mgKOH/g or more and 135 mgKOH/g or less, and if the acid value is in the range of 90 mgKOH/g or more and 130 mgKOH/g or less It is particularly preferred.

The unsaturated compound (B) has at least one ethylenic unsaturated bond per molecule. The unsaturated compound (B) can impart photocurability to the photosensitive resin composition. Examples of the unsaturated compound (B) include monofunctional (meth)acrylates such as 2-hydroxyethyl (meth)acrylate; And diethylene glycol di(meth)acrylate, trimethylolpropanedi(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate , Dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ε-caprolactone modified pentaerythritol hexaacrylate, tricyclodecane dimethanol di (meth) acrylate, etc. It may contain at least one compound selected from the group consisting of (meth)acrylates.

In particular, it is preferable that the unsaturated compound (B) contains a trifunctional compound, that is, a compound having three unsaturated bonds in one molecule. In this case, the resolution in the case of exposing and developing a film formed from the photosensitive resin composition is improved, and further, the developability of the photosensitive resin composition by an alkaline aqueous solution is particularly improved. Trifunctional compounds include, for example, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ethoxylated isocyanurate tri( It may contain at least one compound selected from the group consisting of meth)acrylate and ε-caprolactone-modified tris-(2-acryloyloxyethyl)isocyanurate and ethoxylated glycerin tri(meth)acrylate have.

It is also preferable that the unsaturated compound (B) contains a phosphorus-containing compound (phosphorus-containing unsaturated compound). In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. The phosphorus-containing unsaturated compound is, for example, 2-methacryloyloxyethyl acid phosphate (as a specific example, light ester P-1M manufactured by Kyoeisha Chemical Co., and light ester P-2M), 2- Acryloyloxyethyl acid phosphate (as a specific example, product number light acrylate P-1A manufactured by Kyoeisha Chemical Co., Ltd.), diphenyl-2-methacryloyloxyethyl phosphate (as a specific example, Daihachi Kogyo Corporation) MR-260 manufactured by Shiki Corporation), and HFA series manufactured by Showa Kobunshi Corporation (as specific examples, dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phos) Fophenanthrene-10-oxide), part numbers HFA-6003, and HFA-6007, caprolactone-modified dipentaerythritol hexaacrylate and HCA (9,10-dihydro-9-oxa-10-phospho It may contain at least one compound selected from the group consisting of article numbers HFA-3003, HFA-6127, etc., which are addition reaction products of phenanthrene-10-oxide).

The unsaturated compound (B) may contain a prepolymer. The prepolymer may contain, for example, a prepolymer obtained by polymerizing a monomer having an ethylenically unsaturated bond and then adding an ethylenically unsaturated group, and at least one compound selected from the group consisting of oligo(meth)acrylate prepolymers. have. Oligo (meth) acrylate prepolymers are, for example, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate , And at least one component selected from the group consisting of spiran resin (meth)acrylate.

The unsaturated compound (B) may contain an unsaturated compound (B1) having a bisphenol fluorene skeleton. Unsaturated compounds (B1) are, for example, bisphenoxyethanolfluorene, bisphenoxyfluorenedimethacrylate, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl] It may contain at least one component selected from the group consisting of fluorene. Examples of specific products of the unsaturated compound (B1) include product names A-BPEF manufactured by Shinnakamura Chemical Industry Co., Ltd., product names TBIS-G and TBIS-MPN manufactured by Taoka Chemical Industry Co., Ltd., and Osaka Gas Chemical Corporation. They are product names EA-200 and EA-1000 manufactured by Shikig.

As described above, the light absorption spectrum of the photopolymerization initiator (C) has a first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and a second absorption band that is longer than 370 nm and within a wavelength range of 415 nm or less. Therefore, in exposing the coating film of the photosensitive resin composition to produce a film, the photopolymerization initiator (C) can contribute to improving the deep curing property of the coating film. In particular, it is preferable that the second absorption band includes an absorption band within a wavelength range of at least 400 nm to 415 nm. In this case, in forming a film by exposing the coating film of the photosensitive resin composition, it can contribute to further improving the deep curing property of the coating film. In this embodiment, the term "having an absorption band" in a specific wavelength range in the absorption spectrum of the photoinitiator (C) means, in the absorption spectrum of the photoinitiator (C), "350 nm or more of 370 nm of the photoinitiator (C). It means that the area under the curve in the specific wavelength range is 2% or more with respect to the area under the curve in the following wavelength range. For example, when the absorption spectrum of the photoinitiator (C) is “having an absorption band in the wavelength range of greater than 370 nm and less than 415 nm”, the photopolymerization initiator (C) is “light in the wavelength range greater than 370 nm and less than 415 nm”. In the absorption spectrum of the photopolymerization initiator (C), and in the wavelength range of the wavelength range greater than 370 nm and less than 415 nm for the curved area of the wavelength range of 350 nm or more and 370 nm or less of the photopolymerization initiator (C). It means that the area under the curve is 2% or more. Hereinafter, the same applies to each wavelength range of the absorption spectrum of the photopolymerization initiator (C).

Moreover, it is also preferable that the photoinitiator (C) has the characteristic of absorbing light of a wavelength of 305 nm or more and 325 nm or less. That is, it is preferable that the light absorption spectrum of the photoinitiator (C) further includes a third absorption band within a wavelength range of 305 nm or more and 325 nm or less. In this case, in forming a film by exposing the coating film of the photosensitive resin composition, the curability of the surface of the coating film can be further improved. Of course, the light absorption spectrum of the photopolymerization initiator (C) may further have absorption bands other than the first absorption band, the second absorption band, and the third absorption band described above. That is, the light absorption spectrum of the photopolymerization initiator (C) may have an absorption band in a wavelength of less than 305 nm, or may have an absorption band in a wavelength longer than 415 nm.

The photoinitiator (C) can contain an appropriate compound. In particular, the photopolymerization initiator (C) is at least one selected from the group consisting of an acylphosphine oxide photopolymerization initiator (C1), an α-aminoalkylphenone photopolymerization initiator (C2), and an oxime ester photopolymerization initiator (C3). It is preferable to contain. In this case, when the coating film of the photosensitive resin composition is exposed to produce a film, the deep curing property of the coating film can be further improved. Further, in this case, when exposing the photosensitive resin composition to ultraviolet rays, high photosensitivity can be imparted to the photosensitive resin composition. In addition, generation of ion migration in the layer containing the cured product of the photosensitive resin composition is suppressed, and the insulation reliability of the copper layer can be further improved. In particular, the acylphosphine oxide-based photopolymerization initiator (C1) has a high photobleaching effect, has high deep curing properties, and can also reduce discoloration of the coating film of the photosensitive resin composition. Further, the acylphosphine oxide-based photopolymerization initiator (C1) is difficult to impair the electrical insulating properties of the cured product of the photosensitive resin composition. Therefore, by exposing and curing the photosensitive resin composition, a cured product excellent in electrical insulation is obtained, and this cured product is suitable as, for example, a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer.

The acylphosphine oxide-based photopolymerization initiator (C1) is, for example, a mono(2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide or 2,4,6-trimethylbenzoyl-ethyl-phenyl-phosphinate). Acylphosphine oxide-based photopolymerization initiator, and bis-(2,6-dichlorobenzoyl)phenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2, 6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis-(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis -(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide, bis-(2, Selected from the group consisting of bisacylphosphine oxide-based photopolymerization initiators such as 4,6-trimethylbenzoyl)phenylphosphine oxide, (2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide It contains at least one component. In particular, it is preferable that the acylphosphine oxide-based photopolymerization initiator (C1) contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and the acylphosphine oxide-based photopolymerization initiator (C1) is 2,4,6 It is also preferable to contain only -trimethylbenzoyl-diphenyl-phosphine oxide. In this case, it is possible to impart higher deep curing properties to the coating film formed of the photosensitive resin composition.

α-amino alkylphenone photopolymerization initiator (C2) is, for example, 2-methyl-1-(4-methylthiophenyl)-2-morpholino propan-1-one, 2-benzyl-2-dimethylamino -1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl] It contains at least one component selected from the group consisting of -1-butanone. The α-amino acetophenone-based photopolymerization initiator (C2) can impart higher deep curing properties to a coating film formed of the photosensitive resin composition.

The oxime ester photoinitiator (C3) is, for example, 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], and ethanone, 1-[9- It may contain at least one component selected from the group consisting of ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime). As an example of a more specific product of a component that can be included in the oxime ester-based photopolymerization initiator (C3), BASF, product numbers Irgacure OXE 01, Irgacure OXE 02, and Adeka optomer N-1919, a Deca Acruze NCI-831, and Adeca Acruze NCI-930 are mentioned.

It is preferable that the absorption spectrum of light of the oxime ester type photoinitiator (C1) has absorption in a wavelength range longer than 350 nm. In this case, since the deep curing property of the coating film formed of the photosensitive resin composition can be improved, high sensitivity of the coating film can be realized. Therefore, the photosensitive resin composition is particularly suitable for applications such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer.

It is preferable that the photoinitiator (C) contains a hydrogen extraction type photoinitiator (C4). In this case, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film has a higher resolution. In this case, the shape of the hole can be made more pronounced in producing a film having holes by developing after exposure.

The hydrogen drawing type photoinitiator (C4) contains at least one component selected from the group consisting of, for example, a bis(dialkylamino)benzophenone-based photoinitiator (C41), and a thioxanthone-based photoinitiator (C42). do.

Bis(dialkylamino)benzophenone-based photoinitiator (C41) is, for example, 4,4'-bis(diethylamino)benzophenone (EAB), and 4,4'-bis(dimethylamino)benzophenone It contains at least one component selected from the group consisting of. Particularly, it is preferable that the bis(dialkylamino)benzophenone-based photopolymerization initiator (C41) contains 4,4'-bis(diethylamino)benzophenone. In this case, in developing after partially exposing the coating film formed of the photosensitive resin composition, the resolution becomes particularly high. Therefore, it becomes possible to form a very fine pattern with the cured product of the photosensitive resin composition. In particular, in the case of forming an interlayer insulating layer of a multilayer printed wiring board with a photosensitive resin composition and forming a small-diameter hole for a through hole in the interlayer insulating layer by a photolithography method, a small-diameter hole is formed. It becomes possible to form precisely and easily.

Thioxanthone photoinitiator (C42) is, for example, 2,4-diethyl thioxanthone, 2-isopropyl thioxanthone, 4-isopropyl thioxanthone, and 2,4-diisopropyl thioxanthone It contains at least one component selected from the group consisting of thioxanthones such as.

The photoinitiator (C) may contain a hydroxyketone system photoinitiator. The hydroxy ketone type photoinitiator is, for example, 1-hydroxy-cyclohexyl-phenyl-ketone, phenylglyoxylic acid methyl ester, 1-[4-(2-hydroxyethoxy)-phenyl]-2- Hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl -It contains at least one compound selected from the group consisting of propan-1-one and 2-hydroxy-2-methyl-1-phenyl-propan-1-one.

The photopolymerization initiator (C) may contain only one component or two or more components among the components that can be included in the photopolymerization initiator (C) described above. When the photoinitiator (C) contains two or more components, the above-described light absorption properties of the photoinitiator (C) in the present embodiment may be achieved by a combination of two or more components.

The amount of the acylphosphine-based photopolymerization initiator (C1) relative to the total amount of the photopolymerization initiator (C) is preferably 20% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 95% by mass or less. The amount of the α-aminoalkylphenone-based photopolymerization initiator (C2) relative to the total amount of the photopolymerization initiator (C) is preferably 20% by mass or more and 100% by mass or less, and more preferably 50% by mass or more and 95% by mass or less. The amount of the oxime ester photopolymerization initiator (C3) relative to the total amount of the photopolymerization initiator (C) is preferably 1% by mass or more and 100% by mass or less, and more preferably 5% by mass or more and 40% by mass or less. In addition, the amount of the hydrogen extraction type photopolymerization initiator (C4) relative to the total amount of the photopolymerization initiator (C) is preferably 1% by mass or more and 60% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and 1% by mass or more. It is more preferably 5% by mass or less.

The photosensitive resin composition may further contain a photopolymerization accelerator, a sensitizer, or the like, as long as it does not depart from the spirit of the present invention. For example, the photosensitive resin composition includes benzoin and its alkyl ethers; Acetophenones such as acetophenone and benzyl dimethyl ketal; Anthraquinones such as 2-methylanthraquinone; Benzophenones such as benzophenone and 4-benzoyl-4'-methyldiphenyl sulfide; And at least one component selected from the group consisting of xanthones such as 2,4-diisopropylxanthone. The photosensitive resin composition, together with a photoinitiator (C), is a photopolymerization accelerator or sensitizer such as tertiary amines such as p-dimethylbenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ester, and 2-dimethylaminoethylbenzoate. You may contain agents, etc.

The epoxy resin (D) can impart thermosetting property to the photosensitive resin composition. It is preferable that the epoxy resin (D) contains a crystalline epoxy resin (D1). In this case, developability of the photosensitive resin composition can be improved. In addition, since the organic filler (E1) has a carboxyl group, the compatibility of the crystalline epoxy resin (D1) with the organic filler (E1) is improved, and the recrystallization of the crystalline epoxy resin (D1) in the photosensitive resin composition is prevented. can do. In addition, the epoxy resin (D) may further contain an amorphous epoxy resin (D2). Here, "crystalline epoxy resin" is an epoxy resin having a melting point, and "amorphous epoxy resin" is an epoxy resin having no melting point.

Crystalline epoxy resin (D1) is, for example, 1,3,5-tris (2,3-epoxypropyl)-1,3,5-triazine-2,4,6 (1H,3H,5H) -Trion, hydroquinone type crystalline epoxy resin (as a specific example, product name YDC-1312 manufactured by Shinnittetsu Sumikin Chemical Co., Ltd.), biphenyl type crystalline epoxy resin (manufactured by Mitsubishi Chemical Corporation as a specific example) YX-4000), diphenyl ether type crystalline epoxy resin (as a specific example, product number YSLV-80DE manufactured by Shinnittetsu Sumikin Chemical Co., Ltd.), bisphenol type crystalline epoxy resin (as a specific example, Shinnittetsu Sumikin Consisting of YSLV-80XY manufactured by Chemical Industry Co., Ltd.), tetrakisphenolethane type crystalline epoxy resin (part number GTR-1800 manufactured by Nippon Kayaku Corporation as a specific example), and bisphenol fluorene type crystalline epoxy resin It is preferable to contain at least one component selected from the group.

It is preferable that the crystalline epoxy resin (D1) has two epoxy groups per molecule. In this case, while the temperature change is repeated, it may be more difficult to generate cracks in the cured product.

It is preferable that the crystalline epoxy resin (D1) has an epoxy equivalent of 150 g/eq or more and 300 g/eq or less. This epoxy equivalent is the gram weight of the crystalline epoxy resin (D1) containing 1 gram equivalent of an epoxy group. Crystalline epoxy resin (D1) has a melting point. As the melting point of the crystalline epoxy resin (D1), 70°C or more and 180°C or less are mentioned, for example.

In particular, it is preferable that the epoxy resin (D) contains a crystalline epoxy resin (D1-1) having a melting point of 110°C or less. In this case, developability of the photosensitive resin composition by an alkaline aqueous solution is particularly improved. The crystalline epoxy resin (D1-1) having a melting point of 110° C. or lower is, for example, a biphenyl type epoxy resin (as a specific example, product number YX-4000 manufactured by Mitsubishi Chemical Co., Ltd.), and a biphenyl ether type epoxy resin ( As a specific example, the product number YSLV-80DE manufactured by Shinnittetsu Sumikin Chemical Co., Ltd.), and a bisphenol type epoxy resin (as a specific example, product number YSLV-80XY manufactured by Shinnittetsu Sumikin Chemical, Inc.), bisphenol fluorene type crystalline epoxy resin It may contain at least one component selected from the group consisting of.

The amorphous epoxy resin (D2) is, for example, a phenol novolak type epoxy resin (as a specific example, part number EPICLON N-775 manufactured by DIC Corporation), a cresol novolak type epoxy resin (as a specific example, DIC Corporation). Manufacturing part number EPICLON N-695), bisphenol A novolak type epoxy resin (as a specific example, product number EPICLON N-865 manufactured by DIC Corporation), bisphenol A type epoxy resin (as a specific example, manufactured by Mitsubishi Chemical Co., Ltd. Part number jER1001), bisphenol F type epoxy resin (as a specific example, product number jER4004P manufactured by Mitsubishi Chemical Corporation), bisphenol S type epoxy resin (as a specific example, product number EPICLON EXA-1514 manufactured by DIC Corporation), bisphenol AD type Epoxy resin, biphenyl novolak type epoxy resin (part number NC-3000 manufactured by Nippon Kayaku Corporation as a specific example), hydrogenated bisphenol A type epoxy resin (part number manufactured by Shinnittetsu Sumikin Chemical Co., Ltd. as a specific example) ST-4000D), naphthalene type epoxy resin (as a specific example, part numbers EPICLON HP-4032, EPICLON HP-4700, EPICLON HP-4770 manufactured by DIC Corporation), tertiary butyl catechol type epoxy resin (as a specific example, DIC Corporation Part number EPICLON HP-820 manufactured by Geisha), dicyclopentadiene type epoxy resin (part number EPICLON HP-7200 manufactured by DIC as a specific example), adamantane type epoxy resin (part number ADAMANTATEX manufactured by Idemitsu Kosan Co., Ltd. as a specific example) -E-201), special bifunctional epoxy resin (as a specific example, part numbers YL7175-500, manufactured by Mitsubishi Chemical Corporation, and YL7175-1000; part numbers EPICLON TSR-960 manufactured by DIC Corporation, EPICLON TER- 601, EPICLON TSR-250-80BX, EPICLON 1650-75MPX, EPICLON EXA-4850, EPICLON EXA-4816, EPICLON EXA-4822, and EPICLON EXA-9726; Shinnittetsu Sumikin Chemical Co., Ltd. product number YSLV-120TE), rubber core-shell polymer modified bisphenol A type epoxy resin (as a specific example, Kaneka Co., Ltd. product number MX-156), rubber core shell polymer Modified bisphenol F-type epoxy resin (as a specific example, product number MX-136 manufactured by Kaneka, Inc.), and a bisphenol F-type epoxy resin containing rubber particles (as a specific example, product number Kane-Ace MX-130 manufactured by Kaneka, Inc.) It is preferable to contain at least one component selected from the group consisting of.

The epoxy resin (D) may contain a phosphorus-containing epoxy resin. In this case, the flame retardancy of the cured product of the photosensitive resin composition is improved. The phosphorus-containing epoxy resin may be contained in the crystalline epoxy resin (D1), or may be contained in the amorphous epoxy resin (D2). Phosphorus-containing epoxy resins are, for example, phosphoric acid-modified bisphenol F-type epoxy resins (specific examples, part numbers EPICLON EXA-9726 manufactured by DIC Corporation, and EPICLON EXA-9710), manufactured by Shinnittetsu Sumikin Chemical Co., Ltd. Epotto FX-305, etc.

The epoxy compound (D) may contain an epoxy compound (D3) having a bisphenol fluorene skeleton. This epoxy compound (D3) contains, for example, an epoxy compound (a1) having a bisphenol fluorene skeleton (S1) represented by formula (1) described above.

It is preferable that the photosensitive resin composition contains a coloring agent (E). In this case, in producing a film from the photosensitive resin composition, when exposing the coating film of the photosensitive resin composition, scattering in the coating film can be suppressed. Therefore, it is possible to make it more difficult to cause a decrease in resolution due to scattering of light. Thereby, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film can have a higher resolution. In this case, in producing a film having a hole, the shape of the hole can be made more distinct.

The colorant (E) is a substance capable of coloring a film formed of, for example, a photosensitive resin composition. The colorant may contain any of a pigment and a dye. When the photosensitive resin composition contains a colorant, the colorant may contain any of a pigment, a dye, and a colorant. The colorant (E) may contain, for example, one or more materials selected from the group consisting of a black colorant, a blue colorant, and a yellow colorant.

Examples of black colorants include carbon black, naphthalene black, titanium black, lactam black and perylene black.

Examples of the blue colorant include a phthalocyanine compound and an anthraquinone compound.

Examples of the yellow colorant include monoazo compounds, disazo compounds, condensed azo compounds, benzimidazolone compounds, isoindolinone compounds, and anthraquinone compounds.

The colorant (E) may be a colorant of a color other than the above. Colorants of colors other than the above include, for example, at least one component selected from the group consisting of a red colorant, a green colorant, a purple colorant, an orange colorant, and a brown colorant.

Examples of the red colorant include monoazo compounds, disazo compounds, azo lake compounds, benzimidazolone compounds, perylene compounds, diketopyrrolopyrrole compounds, condensed azo compounds, anthraquinone compounds, and Contains quinacridone compounds.

Examples of the green colorant include phthalocyanine-based compounds, anthraquinone-based compounds, and perylene-based compounds.

It is preferable that the photosensitive resin composition contains a component which has a bisphenol fluorene skeleton. In this case, the component having a bisphenol fluorene skeleton can absorb light within a wavelength range of 305 nm or more and 325 nm or less due to the bisphenol fluorene skeleton. Therefore, scattering of light at the time of exposure can be made particularly difficult to occur, and a decrease in resolution can be made more difficult to occur. Components having a bisphenol fluorene skeleton include, for example, a carboxyl group-containing resin having a bisphenol fluorene skeleton (A1), an unsaturated compound having a bisphenol fluorene skeleton (B1), and an epoxy compound having a bisphenol fluorene skeleton (D3). It contains at least one compound selected from the group consisting of.

The amount of the component in the photosensitive resin composition is appropriately adjusted so that the photosensitive resin composition has photocurability and can be developed with an alkaline solution.

The amount of the carboxyl group-containing resin (A) is preferably 5% by mass or more and 85% by mass or less with respect to the solid content of the photosensitive resin composition, more preferably 10% by mass or more and 75% by mass or less, and 20% by mass or more and 60% by mass or less If it is, it is more preferable.

The amount of the unsaturated compound (B) is preferably 1% by mass or more and 50% by mass or less based on the carboxyl group-containing resin (A), more preferably 10% by mass or more and 45% by mass or less, and 15% by mass or more and 40% by mass or less. More preferable.

The amount of the photoinitiator (C) is preferably 0.1% by mass or more and 30% by mass or less, more preferably 1% by mass or more and 25% by mass or less, and 3% by mass or more and 20% by mass or less based on the carboxyl group-containing resin (A). More preferable.

Regarding the amount of the epoxy resin (D), the sum of equivalents of the epoxy groups contained in the epoxy resin (D) is preferably 0.7 or more and 2.5 or less, and 0.7 or more and 2.3 with respect to 1 equivalent of carboxyl groups contained in the carboxyl group-containing resin (A). If it is below, it is more preferable, and if it is 0.7 or more and 2.0 or less, it is still more preferable.

When the photosensitive resin composition contains a colorant (E), the amount of the colorant (E) is preferably 0.1% by mass or more and 15% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less based on the carboxyl group-containing resin (A). Do.

When the photosensitive resin composition contains a component having a bisphenol fluorene skeleton, the amount of the component having a bisphenol fluorene skeleton is preferably 10% by mass or more and 70% by mass or less, and 20% by mass or more with respect to the solid content of the photosensitive resin composition. It is more preferable if it is 60 mass% or less.

When the photosensitive resin composition contains an organic solvent, the amount of the organic solvent is preferably adjusted so that the organic solvent evaporates quickly when drying the coating film formed of the photosensitive resin composition, that is, the organic solvent does not remain in the dried film. . In particular, with respect to the whole photosensitive resin composition, the organic solvent is preferably greater than 0% by mass and 99.5% by mass or less, and more preferably 15% by mass or more and 60% by mass or less. And since a suitable ratio of the organic solvent differs depending on a coating method or the like, it is preferable that the ratio is appropriately adjusted by the coating method.

And the solid content means the total amount of all components excluding volatile components such as a solvent from the photosensitive resin composition.

As long as it does not depart from the gist of the present invention, the photosensitive resin composition may further contain components other than the above components.

For example, the photosensitive resin composition may contain an inorganic filler. In this case, curing shrinkage when curing the coating film formed of the photosensitive resin composition is reduced. The inorganic filler is, for example, at least one selected from the group consisting of barium sulfate, crystalline silica, nano silica, carbon nanotubes, talc, bentonite, hydrotalcite, aluminum hydroxide, magnesium hydroxide, zinc oxide and titanium oxide. May contain ingredients. The ratio of the inorganic filler in the photosensitive resin composition is appropriately set, but it is preferably 0% by mass or more and 200% by mass or less, more preferably 0% by mass or more and 100% by mass or less, and 0% by mass or more with respect to the carboxyl group-containing resin (A). It is more preferably 50% by mass or less.

The photosensitive resin composition includes: toluene diisocyanate-based, morpholine diisocyanate-based, isophorone diisocyanate-based and hexamethylene diisocyanate-based block isocyanates blocked with caprolactam, oxime, malonic acid ester, and the like; Amino resins such as melamine resin, n-butylated melamine resin, isobutylated melamine resin, butylated urea resin, butylated melamine urea cocondensation resin, and benzoguanamine-based cocondensation resin; Various thermosetting resins other than the above; UV curable epoxy (meth)acrylate; Resins obtained by adding (meth)acrylic acid to epoxy resins such as bisphenol A type, phenol novolak type, cresol novolak type, and alicyclic type; And at least one resin selected from the group consisting of high molecular compounds such as diallylphthalate resin, phenoxy resin, urethane resin, and fluororesin.

The photosensitive resin composition may contain a curing agent for curing the epoxy resin (D). The curing agent is, for example, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1 -Imidazole derivatives such as 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, and 4-methyl-N,N-dimethylbenzylamine compound; Hydrazine compounds such as adipic acid hydrazide and sebacic acid hydrazide; Phosphorus compounds such as triphenylphosphine; Acid anhydride; phenol; Mercaptan; Lewis acid amine complex; And it may contain at least one component selected from the group consisting of onium salts. As examples of commercially available products of these components, 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (all are brand names of imidazole compounds) manufactured by Shikoku Chemicals Co., Ltd., U-CAT3503N, U manufactured by San Apro, Inc. -CAT3502T (all are trade names of dimethylamine block isocyanate compounds), DBU, DBN, U-CATSA102, and U-CAT5002 (both bicyclic amidine compounds and salts thereof) are mentioned.

The photosensitive resin composition may contain an adhesive imparting agent. As an adhesion imparting agent, for example, melamine, guanamine, acetoguanamine, benzoguanamine, and 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-4,6 -Diamino-S-triazine, 2-vinyl-4,6-diamino-S-triazine/isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S- And S-triazine derivatives such as triazine/isocyanuric acid adducts.

The photosensitive resin composition is a curing accelerator; Copolymers such as silicone and acrylate; Leveling agents; Adhesive imparting agents such as silane coupling agents; Thixotropic agents; Polymerization inhibitors; Anti-halation agent; Flame retardant; Antifoam; Antioxidants; Surfactants; And at least one component selected from the group consisting of a polymer dispersant.

It is preferable that the content of the amine compound in the photosensitive resin composition is as small as possible. In this case, the electrical insulating properties of the layer made of the cured product of the photosensitive resin composition are difficult to be impaired. Particularly, with respect to the carboxyl group-containing resin (A), the amine compound is preferably 6% by mass or less, and more preferably 4% by mass or less.

The photosensitive resin composition can be prepared by mixing the raw materials for the photosensitive resin composition as described above and kneading by a kneading method using, for example, a three roll mill, a ball mill, a sand mill, or the like. When the raw material of the photosensitive resin composition contains a liquid component, a component having a low viscosity, etc., a portion of the raw material excluding a liquid component and a component having a low viscosity, etc., is first kneaded, and the resulting mixture has a liquid component and viscosity. A photosensitive resin composition may be prepared by adding and mixing a low component or the like.

In consideration of storage stability and the like, a first agent may be prepared by mixing a part of the components of the photosensitive resin composition, and a second agent may be prepared by mixing the remainder of the components. That is, the photosensitive resin composition may contain a 1st agent and a 2nd agent. In this case, for example, among the components of the photosensitive resin composition, the first agent is prepared by mixing and dispersing the unsaturated compound (B) and a part of the organic solvent and a thermosetting component in advance, and the remainder of the components of the photosensitive resin composition is mixed. By dispersing, you may prepare a 2nd agent. In this case, the required amount of the first agent and the second agent are mixed in a timely manner to prepare a mixed solution, and the mixed solution is cured to obtain a cured product.

The photosensitive resin composition according to the present embodiment is suitable as an electrical insulating material for a printed wiring board. In particular, the photosensitive resin composition is suitable for forming an electrically insulating layer such as a solder resist layer, a plating resist layer, an etching resist layer, and an interlayer insulating layer.

When the photosensitive resin composition is molded into a film having a thickness of 25 µm, it is preferable that the film is developable with an aqueous sodium carbonate solution. In this case, since it is possible to produce an electrically insulating layer with a sufficiently large thickness with a photosensitive resin composition by photolithography, the photosensitive resin composition is widely applied to produce interlayer insulating layers, solder resist layers, etc. in printed wiring boards. It is possible. Of course, it is also possible to produce an electrically insulating layer thinner than 25 μm in thickness with the photosensitive resin composition.

That the film can be developed in an aqueous sodium carbonate solution can be confirmed by the following method. A wet coating film is formed by applying a photosensitive resin composition on a suitable substrate, and the wet coating film is heated at 80 DEG C for 40 minutes to form a 25 mu m thick film. In a state where a negative mask having an exposed portion that transmits ultraviolet rays and a non-exposed portion that shields ultraviolet rays is directly applied to the film, ultraviolet rays are irradiated to the film through the negative mask at 500 mJ/cm 2. A 30° C. 1% Na ₂ CO ₃ aqueous solution was sprayed onto the exposed film for 90 seconds at an injection pressure of 0.2 MPa, and then pure water was sprayed for 90 seconds at an injection pressure of 0.2 MPa. As a result of observing the film after this treatment, when the portion corresponding to the non-exposed portion of the film is removed and no residue is recognized, it can be determined that the film can be developed.

As described above, the method for producing a film according to the present embodiment includes a step of forming a coating film on the substrate by disposing a coating film of a photosensitive resin composition on the substrate, a step of irradiating the coating film with light to expose, and exposure. And a step of developing the subsequent coating film with an alkaline solution. Hereinafter, a method of manufacturing a film formed from the photosensitive resin composition of the present embodiment, and a method of manufacturing a printed wiring board including the film will be described in detail with reference to FIGS. 3A to 3E. .

In order to form a coating film of a photosensitive resin composition on a substrate, first, as shown in FIG. 3A, a core material 1 is prepared as a substrate. The core material 1 includes, for example, at least one insulating layer 2 and at least one conductive layer 3. The conductive layer 3 may be a conductor wiring. The conductive layer 3 formed on one surface of the core material 1 is hereinafter referred to as the first conductor wiring 31. As shown in FIG. 3B, a coating film 4 made of a photosensitive resin composition is formed on the surface of the core material 1 on which the first conductor wiring 31 is provided. In order to form the coating film 4 from the photosensitive resin composition, for example, it may be formed by a method such as a coating method and a dry film method.

In the coating method, for example, a photosensitive resin composition is applied onto a substrate such as the core material 1 to form a wet coating film. The application method of the photosensitive resin composition is selected from the group consisting of, for example, an immersion method, a spray method, a spin coat method, a roll coat method, a curtain coat method, and a screen printing method. Subsequently, in order to volatilize the organic solvent in the photosensitive resin composition, for example, the wet coating film is dried under a temperature in the range of 60 to 120°C, and the coating film 4 (dry coating film) can be obtained.

In the dry film method, a dry film containing a photosensitive resin composition is formed on the support by first applying a photosensitive resin composition on a suitable support such as a polyester and then drying. Thereby, a dry film with a support body provided with a dry film and a support body which supports a dry film is obtained. After the dry film in the dry film with a support is superimposed on the core material 1, pressure is applied to the dry film and the core material 1, and then the support is removed from the dry film, thereby removing the dry film from the support. It is transferred onto the ash (1). Thereby, on the core material 1, the coating film 4 made of a dry film is formed.

In this way, the coating film 4 of the photosensitive resin composition is disposed on a substrate such as the core material 1, and the coating film 4 can be formed on the substrate.

It is preferable that the maximum absorbance of light in the wavelength range of 305 nm or more and 325 nm or less with respect to the maximum absorbance in the wavelength range of 350 nm or more and 370 nm or less in the absorption spectrum of light of the coating film 4 of the present embodiment is 3 times or more. Do. In this case, in exposing the coating film formed of the photosensitive resin composition, scattering of light in the coating film can be suppressed. Therefore, it is possible to make it more difficult to cause a decrease in resolution due to scattering of light. Thereby, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film can have a higher resolution. In this case, for example, in producing a film having pores by a photolithography method using a photosensitive resin composition, the shape of the pores can be made more distinct. And the absorption spectrum of the coating film is measured with a spectrophotometer or other spectroscopic analyzer, for example. A specific measurement method can be measured in the same manner as in the evaluation test (4-1) of Examples described later.

Next, the coating film 4 formed on the core material 1 above is irradiated with light to expose the coating film 4. In exposing the coating film 4, for example, light emitted from a light source can be irradiated onto the coating film 4. In the present embodiment, the spectrum of light irradiated to the coating film in the exposure step is, as described above, a first intensity distribution overlapping with the first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and greater than 370 nm. It has a second intensity distribution overlapping with the second absorption band in a wavelength range of 415 nm or less, and a third intensity distribution in a wavelength range of 305 nm or more and 325 nm or less. That is, the light irradiated to the coating film in the exposure process includes the first light, the second light, and the third light. The wavelength range of the first light is within the wavelength range of the first absorption band, the wavelength range of the second light is within the wavelength range of the second absorption band, and the wavelength range of the third light is within the wavelength range of 305 nm or more and 325 nm or less. In this light spectrum, the area under the curve in the wavelength range smaller than 280 nm and up to 200 nm, and the area under the curve in the wavelength range larger than 415 nm and up to 500 nm, for the area under the curve in the wavelength range of 200 nm to 500 nm, and The percentage of the sum of is not more than 5%.

The light source is preferably at least one selected from the group consisting of a metal halide lamp, a high-pressure mercury lamp, and an ultra-high pressure mercury lamp. In this case, a high resolution image can be formed with a short exposure time.

In the present embodiment, in the step of exposing, after passing the light emitted from the light source through an optical filter that cuts light within a wavelength range shorter than 280 nm and not less than 200 nm, and light within a wavelength range longer than 415 nm and less than 500 nm. , It is preferable to irradiate the coating film. In this case, in the spectrum of light irradiated to the coating film, the area under the curve in the wavelength range less than 280 nm and up to 200 nm and the wavelength range from 415 nm to 500 nm with respect to the area under the curve in the wavelength range of 200 nm to 500 nm The percentage of the sum of the areas under the curve of the range can be set to 5% or less.

The coating film may be irradiated with light emitted from light sources other than a metal halide lamp, a high-pressure mercury lamp, and an ultra-high-pressure mercury lamp as long as it does not depart from the gist of the present invention.

As the optical filter, an appropriate filter for cutting light in a predetermined wavelength range can be adopted. Examples of the optical filter include, for example, a band-pass filter that transmits only light in a specific wavelength range and cuts other light on the short wavelength side and the long wavelength side. In addition, as long as the optical filter has the above function, by combining a long pass filter and a short pass filter, or two or more of these, light in a specific wavelength range (for example, light with a wavelength shorter than 280 nm and less than 415 nm). You may configure so that only light other than light of long wavelength) may be transmitted. In addition, the optical filter is not particularly limited in its dimensions, shapes, and arrangement methods. For example, the optical filter should just be arrange|positioned at the position between the coating film 4 and the light source.

By exposing the coating film 4 to light, the coating film 4 is partially photocured as shown in Fig. 3C. For example, after applying a negative mask to the coating film 4, light is irradiated to the coating film 4 through the negative mask. The negative mask includes an exposed portion that transmits light and a non-exposed portion that shields light, and the non-exposed portion is formed at a position coincident with the position of the through hole 10. The negative mask is, for example, a photo tool such as a mask film and a dry plate.

In addition, in exposing, a method other than the method of using the above negative mask may be adopted. For example, the coating film 4 may be exposed by a direct drawing method in which light emitted from a light source is irradiated only on a portion to be exposed on the coating film 4. The light source applied to the direct drawing method is selected from the group consisting of a laser, a light emitting diode (LED), a high-pressure mercury lamp, an ultra-high pressure mercury lamp, and a metal halide lamp, for example.

In addition, in the dry film method, the dry film in the dry film with a support is superimposed on the core material 1, and then the support is passed through the support without peeling off the support, and ultraviolet rays are irradiated to the coating film 4 made of the dry film to expose it. Then, before developing treatment, the support may be removed from the exposed coating film 4.

Subsequently, the unexposed portion (non-exposed portion) 5 of the coating film 4 shown in FIG. 3C is removed by performing a development treatment on the exposed coating film 4. Thereby, as shown in FIG. 3D, the hole 6 is formed in the position where the through hole 10 in the film 40 is formed.

In the developing treatment, an appropriate developer according to the composition of the photosensitive resin composition can be used. The developer is, for example, an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, or an organic amine. The alkaline aqueous solution is, for example, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen chloride, potassium hydrogen carbonate, ammonium hydrogen carbonate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and lithium hydroxide. It contains at least one component selected from. The solvent in the alkaline aqueous solution may be water alone or a mixture of water and a hydrophilic organic solvent such as lower alcohols. The organic amine contains, for example, at least one component selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine.

The developer is preferably an alkaline aqueous solution containing at least one of an alkali metal salt and an alkali metal hydroxide, and particularly preferably an aqueous sodium carbonate solution. In this case, it is possible to improve the working environment and reduce the burden of waste treatment.

Thereby, the film 40 containing the photosensitive resin composition can be produced on the base material. The shape of the film 40 containing the photosensitive resin composition prepared in this way can have high resolution. In addition, in this case, the shape of the hole formed in the film 40 can be made more distinct.

The film 40 produced above may be further subjected to the following treatment.

For example, you may heat cure the film 40 by heating. Heating conditions are, for example, within the range of a heating temperature of 120 to 200°C and a heating time of 30 to 120 minutes. In this case, the performance such as strength, hardness, and chemical resistance of the interlayer insulating layer 7 formed of the film 40 is improved. If necessary, the film 40 may be further irradiated with ultraviolet rays either or both before heating and after heating. In this case, the photocuring of the film 40 can be further advanced.

Thereby, an interlayer insulating layer 7 including, for example, a film 40 of a photosensitive resin composition (which can also be referred to as a cured product of a photosensitive resin composition) is formed on a substrate such as a core material 1 .

Further, the coating 40 (interlayer insulating layer 7) may be subjected to a plating treatment. Plating treatment can adopt an appropriate method, for example, on the interlayer insulating layer 7 by a method such as an additive method, the second conductor wiring 8 and the hole plating 9 can be formed. have. Thereby, as shown in E of FIG. 3, an interlayer insulating layer interposed between the first conductor wiring 31, the second conductor wiring 8, and the first conductor wiring 31 and the second conductor wiring 8 (7) And a printed wiring board 11 including a through hole 10 for electrically connecting the first conductor wiring 31 and the second conductor wiring 8 can be obtained. In Fig. 3E, the hole plating 9 has a cylindrical shape covering the inner surface of the hole 6, but the hole plating 9 is filled in the entire inside of the hole 6 You may have it. In forming the hole plating 9, an initial wiring can be formed by performing an electroless metal plating treatment on a part of the roughened outer surface to be described later and the inner surface of the hole 6. Thereafter, in the electrolytic metal plating treatment, the hole plating 9 can be formed by depositing metal in the electrolytic plating solution on the initial wiring.

Further, before performing the plating treatment, the surface of the film 40 may be roughened by performing a roughening treatment on the film 40. For example, in order to match a part of the outer surface of the interlayer insulating layer 7 and the entire inner surface of the hole 6, it can be performed in the same procedure as a general desmear treatment using an oxidizing agent. For example, an oxidizing agent is brought into contact with the outer surface of the interlayer insulating layer 7 to provide a rough surface to the interlayer insulating layer 7. However, the present invention is not limited thereto, and a method of imparting a rough surface to a cured product such as plasma treatment, UV treatment or ozone treatment may be appropriately employed. The oxidizing agent may be an oxidizing agent available as a desmear liquid. For example, a commercially available swelling liquid for desmear and a desmear liquid may constitute an oxidizing agent. Such an oxidizing agent may contain, for example, at least one permanganate selected from the group of sodium permanganate and potassium permanganate.

An example of a method of manufacturing a printed wiring board including a solder resist layer formed of the photosensitive resin composition according to the present embodiment will be described.

First, a core material serving as a base material is prepared. The core material includes, for example, at least one insulating layer and at least one conductor wiring (conductive layer). A coating film is formed from a photosensitive resin composition on the surface of the core material on which the conductor wiring is provided. As a method of forming a coating film, a coating method and a dry film method can be mentioned. As the coating method and the dry film method, the same method as in the case of forming a coating film on the above substrate can be adopted. It is partially photocured by exposing the coating film. As for the exposure method, the same method as in the case of forming the above-described interlayer insulating layer can be employed. Subsequently, a developing treatment is performed on the coating film to remove the unexposed portion of the coating film, whereby the exposed portion of the coating film remains on the core material. Subsequently, the film formed on the core material is heat-cured. As for the developing method and the heating method, the same method as in the case of forming the above-described interlayer insulating layer can be adopted. If necessary, the film may be further irradiated with ultraviolet rays either or both before heating and after heating. In this case, photocuring of the film can be further advanced.

As described above, a solder resist layer made of a cured product of the photosensitive resin composition is formed on the core material. Thereby, a printed wiring board comprising a core material including an insulating layer and conductor wiring (conductive layer) thereon, and a solder resist layer partially covering the surface of the core material on which the conductor wiring is provided is obtained.

<Example>

Hereinafter, the present invention presents specific examples. However, the present invention is not limited to the examples.

(1) Synthesis of carboxyl group-containing resin

(1-1) Synthesis Example A-1 and Synthesis Example B-1

Into a four-neck flask equipped with a reflux condenser, a thermometer, an air intake pipe, and a stirrer, the components shown in the "first reaction" column in Table 1 were added, and a mixture was prepared by stirring these under air bubbling. This mixture was heated in the flask at the reaction temperature and reaction time indicated in the "Reaction Conditions" column while stirring under air bubbling. Thereby, a solution of the intermediate was prepared.

Subsequently, the components shown in the "second reaction" column of Table 1 were added to the solution of the intermediate in the flask, and the mixture was heated at the reaction temperature and reaction time shown in the "reaction conditions (1)" column while stirring under air bubbling. Subsequently, in Synthesis Example A-1, while stirring under air bubbling, heating was performed at the reaction temperature and reaction time shown in the "reaction conditions (2)" column. Thereby, a 65 mass% solution was obtained in the carboxyl group-containing resin. The polydispersity of the carboxyl group-containing resin (however, except for the carboxyl group-containing resin of Synthesis Example B-1), the weight average molecular weight, and the acid value are as shown in Table 1. The molar ratio between components is also shown in Table 1.

In addition, the details of the components shown in the column (a1) in Table 1 are as follows.

Epoxy compound 1: A bisphenol fluorene type epoxy compound represented by formula (7) and having an epoxy equivalent of 250 g/eq in which R ₁ to R ₈ in formula (7) are all hydrogen

In addition, the details of the component shown in the column (g1) in Table 1 are as follows.

Epoxy compound 2: cresol novolak type epoxy resin (manufactured by Shinnittetsu Sumikin Chemical Co., Ltd., part number YDC-700-5, epoxy equivalent 203g/eq)

[Table 1]

(2) Preparation of photosensitive resin composition (Examples 1 to 9)

After kneading a part of the components shown in the table to be posted later by a three-roll mill, all the components shown in the table to be posted later were stirred and mixed in a flask to obtain a photosensitive resin composition. In addition, the details of the components shown in the table are as follows. In addition, in the following photoinitiators, "does not absorb light" with respect to a specific wavelength, in the absorption spectrum of the photoinitiator, "with respect to the area under the curve in the wavelength range of 350 nm to 370 nm in the photopolymerization initiator, respectively. It means that the area under the curve in the wavelength range is less than 2%. For example, in the absorption spectrum of photopolymerization initiator B, "the photoinitiator B does not absorb light with a wavelength of 400 nm or more and 415 nm or less" means "wavelength range of 350 nm or more and 370 nm or less of photo polymerization initiator B. It means that the area under the curve in the wavelength range of 400 nm or more and 415 nm or less with respect to the area under the curve of is less than 2%.

Unsaturated compound A: trimethylolpropane triacrylate

Unsaturated compound B: mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., part number KAYARAD DPHA)

Photopolymerization initiator A: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by BASF, part number Irgacure TPO); Acylphosphine oxide-based photopolymerization initiator, light with a wavelength of 305 nm or more and 325 nm or less, light with a wavelength of 350 nm or more and 370 nm or less, light with a wavelength longer than 370 nm and less than 400 nm, and 400 nm or more and 415 nm It has the property of absorbing light of the following wavelength

Photopolymerization initiator B: 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (manufactured by BASF, part number Irgacure 907); α-aminoalkylphenone photopolymerization initiator, 305 nm Light with a wavelength of not less than 325 nm, light of a wavelength of 350 nm to 370 nm, and light of a wavelength longer than 370 nm and less than 400 nm, and having a wavelength of 400 nm to 415 nm Does not absorb

Photoinitiator C: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (manufactured by BASF, part number Irgacure OXE 02); Oxime ester photopolymerization initiator, has the property of absorbing light with a wavelength of 305 nm or more and 325 nm or less, light with a wavelength of 350 nm or more and 370 nm or less, and light with a wavelength longer than 370 nm and less than 400 nm, 400 nm Does not absorb light with a wavelength of 415 nm or less

Photopolymerization initiator D: 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF, part number Irgacure 184); α-hydroxyalkylphenone-based photopolymerization initiator, which absorbs light with a wavelength of 305 nm or more and 325 nm or less, light with a wavelength of 350 nm or more and 370 nm or less, and light with a wavelength longer than 370 nm and less than 400 nm. It has, and does not absorb light with a wavelength of 400 nm or more and 415 nm or less

Photopolymerization initiator E: 2,4-diethyl thioxanthone (manufactured by Nippon Kayaku Co., Ltd., product number KAYACURE-DETX-S); Hydrogen extraction type photoinitiator, light with a wavelength of 305 nm or more and 325 nm or less, light with a wavelength of 350 nm or more and 370 nm or less, light with a wavelength longer than 370 nm and less than 400 nm, and light having a wavelength of 400 nm or more and 415 nm or less It has the property of absorbing light of wavelength

Photopolymerization initiator F: 4,4'-bis(diethylamino)benzophenone; Hydrogen extraction type photoinitiator, light with a wavelength of 305 nm or more and 325 nm or less, light with a wavelength of 350 nm or more and 370 nm or less, light with a wavelength longer than 370 nm and less than 400 nm, and light having a wavelength of 400 nm or more and 415 nm or less It has the property of absorbing light of wavelength

Epoxy resin A: Biphenyl type crystalline epoxy resin (Mitsubishi Chemical Co., Ltd. product name YX-4000, melting point 105°C, epoxy equivalent 187 g/eq)

Solution of epoxy resin B: A bisphenol A type epoxy resin containing long-chain carbon chain (manufactured by DIC, part number EPICLON EXA-4816, liquid resin, epoxy equivalent 410 g/eq) was dissolved in diethylene glycol monoethyl ether acetate at 90% solid content. Solution (Epoxy equivalent in terms of 90% solid content is 455.56 g/eq)

· Solution of epoxy resin C: Cresol novolak type epoxy resin (YDCN-704 manufactured by Shinnittetsu Sumikin Chemical Co., Ltd., softening point 87 to 97°C, epoxy equivalent 208 g/eq) with 70% solid content of diethylene glycol Solution dissolved in monoethyl ether acetate (the epoxy equivalent of 70% solid content is 297.14 g/eq)

Black colorant: carbon black dispersion, average particle diameter 100 to 300 nm, pigment content 20%, solid content 25%, dispersion solvent: propylene glycol monomethyl ether acetate

Blue colorant: Phthalocyanine blue dispersion, average particle diameter 100 to 300 nm, pigment content 20%, solid content 25%, dispersion solvent: propylene glycol monomethyl ether acetate

Yellow colorant: Nickel complex pigment dispersion, average particle diameter 100 to 300 nm, pigment content 20%, solid content 25%, dispersion solvent: propylene glycol monomethyl ether acetate

Melamine: manufactured by Nissan Chemical Industry Co., Ltd., finely divided melamine; Dispersion at an average particle diameter of 8 µm in the photosensitive resin composition

Antioxidant: Hindered phenolic antioxidant (manufactured by BASF, part number IRGANOX 1010).

Barium sulfate: manufactured by Sakai Chemical Industry Co., Ltd., part number Variece B30

Bentonite: manufactured by Reox, part number Benton SD-2

Dispersion of organic filler: crosslinked rubber (NBR) having a carboxyl group having an average primary particle diameter of 0.07 μm, manufactured by JSR Corporation, product number XER-91-MEK, a methyl ethyl ketone dispersion having a content ratio of 15% by weight of the crosslinked rubber, Acid value 10.0mgKOH/g

Coupling agent: 3-glycidoxypropyltrimethoxysilane

· Antifoam: manufactured by Shin-Etsu Chemical High School, part number KS-66

Surfactant: manufactured by DIC, part number Megapak F-477

Solvent: methyl ethyl ketone

(3) Preparation of test sample (coating film)

Using the photosensitive resin composition prepared in (2) above, a test sample (coating film) was prepared as follows.

The photosensitive resin composition was applied on a polyethylene terephthalate film with an applicator, and then dried by heating at 95° C. for 25 minutes to form a dry coating film (dry film) having a thickness of 25 µm on the film.

A glass epoxy copper clad laminate (FR-4 type) containing copper foil having a thickness of 17.5 µm was prepared. A comb-shaped electrode having a line width/space width of 100 µm/100 µm as a conductor wiring was formed on the glass epoxy copper clad laminate by a subtractive method, thereby obtaining a core material. The conductor wiring was roughened by dissolving and removing the surface layer portion of the core material having a thickness of about 1 µm in the conductor wiring with an etching agent (organic acid microetchant manufactured by Meg Corporation, part number CZ-8101). A dry film was heated and laminated on the entire surface of the core material by a vacuum laminator. The conditions of the heating lamination are 0.5 MPa, 80 degreeC, and 1 minute. As a result, a coating film having a thickness of 25 µm made of a dry film was formed on the core material. The coating film thus obtained was evaluated as a test sample for the following (4-2) evaluation test.

(4) Evaluation test

(4-1) absorbance characteristics

The photosensitive resin composition of each example was applied on a film made of polyethylene terephthalate with an applicator, and then dried by heating at 95° C. for 25 minutes to form a dry coating film having a thickness of 10 μm on the film. The dried coating film of each Example formed on the film made of polyethylene terephthalate was set in an ultraviolet visible near-infrared spectrophotometer (product number UV-3100PC manufactured by Shimadzu Corporation), and the dried coating film absorbed 300 to 800 nm. The spectrum was measured. For the reference, a film made of polyethylene terephthalate as a base material was used. From the obtained absorption spectrum, the value of [maximum absorbance at wavelength 305 to 325 nm]/[maximum absorbance at wavelength 350 to 370 nm] (that is, maximum absorbance of light in a wavelength range of 350 nm to 370 nm) The value of the ratio of the maximum absorbance of light in the wavelength range of 305 nm or more and 325 nm or less was calculated according to the following criteria.

○: The value of [maximum absorbance at wavelength 305 to 325 nm]/[maximum absorbance at wavelength 350 to 370 nm] is 3 or more

×: The value of [maximum absorbance at wavelength 305 to 325 nm]/[maximum absorbance at wavelength 350 to 370 nm] is less than 3

(4-2) shape of hole

The shape of the hole formed in the film was evaluated by developing after exposure to the test sample (coating film) of each Example produced in the above (3). Specifically, an optical filter and a negative mask in a state in which a negative mask of quartz glass having a circular non-exposed portion having a diameter of 60 μm and a non-exposed portion of a circular shape having a diameter of 60 μm was directly applied to the test sample (coating film) of each example. Light was irradiated to the coating film through the condition of 400mJ/cm2. As a light source for irradiating light to the coating film, an ultra-high pressure mercury lamp was used. As shown in FIG. 1, the emission spectrum of light emitted by the ultra-high pressure mercury lamp is as shown in FIG. 1 with the horizontal axis as the wavelength (unit nm) and the vertical axis as the relative intensity (unit%), and the wavelength and the relative intensity as shown in FIG. Light was irradiated under the following exposure conditions (conditions A to F). And after exposure, before development, the film made of polyethylene terephthalate was peeled from the coating film.

In the step of exposure, an ultra-high pressure mercury lamp was used as a light source, and the light emitted from the ultra-high pressure mercury lamp was cut out by an optical filter with a specific wavelength, and then irradiated onto the coating film. Below, the wavelength of light irradiated to the coating film and the optical filter used are shown. And, in condition C, the optical filter was not used.

Condition A

The light emitted from the light source was passed through an optical filter that transmits only light in a wavelength range of 280 nm to 415 nm, and then irradiated to the coating film.

Condition B

The light emitted from the light source was passed through an optical filter that transmits only light in a wavelength range of 280 nm to 370 nm, and then irradiated to the coating film.

Condition C

The light emitted from the light source was irradiated to the coating film without passing through the optical filter.

Condition D

The light emitted from the light source was passed through an optical filter that transmits only light in a wavelength range of 350 nm to 370 nm, and then irradiated to the coating film.

Condition E

The light emitted from the light source was passed through an optical filter that transmits only light in a wavelength range of 350 nm to 415 nm, and then irradiated to the coating film.

Condition F

The light emitted from the light source was passed through an optical filter that transmits only light in a wavelength range of 280 nm to 325 nm, and then irradiated to the coating film.

A developing treatment was performed on the coating film (film) after exposure. In the developing treatment, a 30° C. 1% Na ₂ CO ₃ aqueous solution was sprayed onto the film for 90 seconds at an injection pressure of 0.2 MPa. Subsequently, the film was washed by spraying pure water at an injection pressure of 0.2 MPa for 90 seconds. Thereby, the unexposed part of the film was removed to form a hole. Subsequently, the film was heated at 160°C for 60 minutes. As a result, a layer made of a cured product of a photosensitive resin composition (also referred to as a cured product of a dry film) was formed on the core material. Thereby, a test piece was obtained.

The inner diameter of one end and the inner diameter of the other end of the hole in the test piece was measured, and the shape of the hole was evaluated based on the difference between the two inner diameters according to the following criteria.

A: The difference in inner diameter is less than 4 μm

B: The difference in inner diameter is 4 μm or more and less than 6 μm

C: The difference in inner diameter is 6 μm or more and less than 8 μm

D: The difference in inner diameter is 8 μm or more and less than 10 μm

E: The difference in inner diameter is 10 μm or more

F: Since the coating film could not be sufficiently photocured, a hole could not be formed

In Example 2, when the coating film of the photosensitive resin composition was exposed to light under condition A and then developed, as shown in Fig. 2A, the difference in the inner diameter of the hole was small. That is, the shape of the film formed from the photosensitive resin composition was high in resolution, and the shape of the hole formed in the film was clear. In Examples other than Example 2, even when exposure and development were performed under Condition A, equivalent results were obtained.

On the other hand, in Example 2, when exposure and development were performed in the same manner under conditions C and D with respect to the coating film of the photosensitive resin composition, as shown in Fig. 2B and Fig. 2C, the inner diameter of the hole The car has grown. That is, the shape resolution of the film formed from the photosensitive resin composition was lowered, and the shape of the hole formed in the film was found to be disturbed. In Examples other than Example 2, the same results were obtained when exposure and development were performed under conditions C and D.

In Examples, the test pieces obtained under condition A and condition B were evaluated in the following (4-3) to (4-7).

(4-3) Insulation

While applying a DC 12V bias voltage to the conductor wiring (comb-shaped electrode) in the test piece, the test piece was exposed under a test environment of 130°C and 85% R.H. for 100 hours. The electric resistance value between the comb-shaped electrodes of the layer made of the cured product under this test environment was constantly measured, and the result was evaluated as follows.

A: From the start of the test to the lapse of 100 hours, the electrical resistance value always maintained 10 ⁶ Ω or more.

B: The electrical resistance value always maintained 10 ⁶ Ω or more until 70 hours from the start of the test, but the electrical resistance value became less than 10 ⁶ Ω before 100 hours from the start of the test.

C: Electric resistance value became less than 10 ⁶ Ω before 70 hours elapsed from the start of the test

(4-4) acid resistance

After immersing the test piece in 10% sulfuric acid aqueous solution for 30 minutes at room temperature, the appearance of the layer made of the cured product was observed. The results were evaluated as shown below.

A: Abnormalities such as swelling, peeling, and discoloration are not recognized in the layer made of the cured product.

B: Slight abnormalities such as swelling, peeling, and discoloration are perceived in the layer made of the cured product

C: Abnormalities such as swelling, peeling, and discoloration are remarkably recognized in the layer made of the cured product.

(4-5) alkali resistance

After immersing the test piece in an aqueous sodium hydroxide solution having a concentration of 10% by mass at room temperature for 1 hour, the appearance of the layer made of the cured product was observed. The results were evaluated as shown below.

A: Abnormalities such as swelling, peeling, and discoloration are not recognized in the layer made of the cured product

B: Slight abnormalities such as swelling, peeling, and discoloration are perceived in the layer made of the cured product

C: Abnormalities such as swelling, peeling, and discoloration are remarkably recognized in the layer made of the cured product.

(4-6) Solder heat resistance

A water-soluble flux (manufactured by London Chemical, part number LONCO 3355-11) was applied to the layer made of the cured product of the test piece, and the layer made of the cured product was then immersed in a molten solder bath at 260° C. for 10 seconds and washed with water. . After repeating this treatment three times, the appearance of the layer made of the cured product was observed, and the results were evaluated as shown below.

A: Abnormalities such as swelling, peeling, and discoloration are not recognized in the layer made of the cured product

B: Slight abnormalities such as swelling, peeling, and discoloration are perceived in the layer made of the cured product

C: Abnormalities such as swelling, peeling, and discoloration are remarkably recognized in the layer made of the cured product.

(4-7) Plating resistance

Using a commercially available plating solution, electroless nickel plating and electroless gold plating were sequentially performed on the test piece, and then the states of the plated layer and the layer made of the cured product were checked.

Subsequently, the cellophane adhesive tape peeling test of the layer made of the cured product was performed to confirm the adhesion state of the layer made of the cured product after plating.

The result was evaluated as follows.

A: Before and after the formation of the plated layer, no change in appearance was recognized in the layer made of the cured product, no infiltration of the plating was recognized, and no peeling of the layer made of the cured product was recognized in the cellophane adhesive tape peel test.

B: Before and after the formation of the plated layer, a change in the appearance of the layer made of the cured product was not recognized, but partial peeling of the layer made of the cured product was recognized in the cellophane adhesive tape peel test.

C: After formation of the plated layer, the floating of the layer made of the cured product was recognized, and peeling of the layer made of the cured product was recognized in the cellophane adhesive tape peel test.

[Table 2]

(theorem)

As is apparent from the above, the method for producing a film of the first aspect of the present invention includes a step of forming a coating film on the substrate by disposing a photosensitive resin composition on the substrate, and exposure by irradiating the coating film with light emitted from a light source. And a step of developing a coating film after exposure with an alkali solution. The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenic unsaturated bond per molecule, a photoinitiator (C), and an epoxy resin (D). The light absorption spectrum of the photopolymerization initiator (C) has a first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and a second absorption band that is longer than 370 nm and within a wavelength range of 415 nm or less. The light irradiated to the coating film in the step of exposure includes first light, second light, and third light. The wavelength range of the first light is within the wavelength range of the first absorption band. The wavelength range of the second light is within the range of the second absorption band. The wavelength range of the third light is within a wavelength range of 305 nm or more and 325 nm or less. In the spectrum of light irradiated to the coating film, the area under the curve in the wavelength range shorter than 280 nm and up to 200 nm, with respect to the area under the curve in the wavelength range of 200 nm to 500 nm, and the wavelength range longer than 415 nm and up to 500 nm. The percentage of the sum of the areas under the curve is 5% or less.

According to the first aspect, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film has high resolution. Further, when this film has pores, the shape of the pores of the film can be clearly formed.

In the method for producing a film of the second aspect, in the first aspect, the second absorption band includes at least an absorption band that is longer than 400 nm and is within a wavelength range of 415 nm or less. The second light includes at least light in a wavelength range longer than 400 nm and less than 415 nm.

According to the second aspect, the photopolymerization initiator (C) absorbs light in a wavelength range of longer than 400 nm and not more than 415 nm in the coating film to initiate a photopolymerization reaction. Thereby, in the deep part of the coating film of the photosensitive resin composition, it is possible to realize more favorable curability.

In the method for producing a film of the third aspect, in the first or second aspect, the absorption spectrum of the light of the photopolymerization initiator (C) further has a third absorption band within a wavelength range of 305 nm or more and 325 nm or less. The wavelength range of the third light is within the wavelength range of the third absorption band.

According to the third aspect, the surface hardenability of the coating film is particularly easily improved. In addition, since scattering of light having a wavelength of 305 nm or more and 325 nm or less is difficult to occur in the coating film, a decrease in resolution due to the photopolymerization initiator (C) is more difficult to occur.

The manufacturing method of the film of the fourth aspect is 305 nm or more for the maximum absorbance in the wavelength range of 350 nm or more and 370 nm or less in the absorption spectrum of the light of the coating film in any one of the first to third aspects. The maximum absorbance in the wavelength range of 325 nm or less is 3 times or more.

According to the fourth aspect, in exposing the coating film formed from the photosensitive resin composition, scattering of light in the coating film can be suppressed. Therefore, it is possible to make it more difficult to cause a decrease in resolution due to scattering of light. Thereby, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film can have a higher resolution. Further, in producing a film having pores from the photosensitive resin composition by photolithography, the shape of the pores can be made more pronounced.

In the manufacturing method of the film of the fifth aspect, in any one of the first to fourth aspects, the light source is at least one selected from the group consisting of a metal halide lamp, a high pressure mercury lamp, and an ultra high pressure mercury lamp.

According to the fifth aspect, an image with high resolution can be formed in a short exposure time.

In the manufacturing method of the coating film of the sixth aspect, in any one of the first to fifth aspects, in the step of exposing, light emitted from a light source is passed through an optical filter, and then the coating film is irradiated, and the optical filter, Light in the wavelength range shorter than 280 nm and not less than 200 nm, and light in the wavelength range longer than 415 nm and less than 500 nm are cut.

According to the sixth aspect, in the spectrum of light irradiated to the coating film, the area under the curve in the wavelength range less than 280 nm and up to 200 nm, and the area under the curve in the wavelength range of less than 280 nm and up to 200 nm, and greater than 415 nm, 500 nm It is easy to adjust so that the percentage of the sum of the areas under the curve in the wavelength range up to is 5% or less.

In the production method of the film of the seventh aspect, in any one of the first to sixth aspects, the photopolymerization initiator (C) is an acylphosphine oxide-based photopolymerization initiator (C1), an α-aminoalkylphenone-based photopolymerization initiator ( It contains at least one selected from the group consisting of C2) and an oxime ester photoinitiator (C3).

According to the seventh aspect, in forming a film by exposing the coating film of the photosensitive resin composition, the deep curing property of the coating film can be further improved. In addition, when exposing the photosensitive resin composition to ultraviolet rays, high photosensitivity can be imparted to the photosensitive resin composition.

In the film production method of the eighth aspect, in any one of the first to seventh aspects, the photopolymerization initiator (C) contains a hydrogen extraction type photopolymerization initiator (C4).

According to the eighth aspect, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film has a higher resolution. In this case, the shape of the hole can be made more pronounced in producing a film having holes by developing after exposure.

In the manufacturing method of a film of a ninth aspect, in any one of 1st to 8th aspect, the carboxyl group-containing resin (A) contains a carboxyl group-containing resin which has an ethylenically unsaturated group.

According to the ninth aspect, the carboxyl group-containing resin (A) can impart photosensitivity and ultraviolet curing properties to the photosensitive resin composition together with the unsaturated compound (B).

In the manufacturing method of the film of the tenth aspect, in any one of the first to ninth aspects, the photosensitive resin composition contains a component having a bisphenol fluorene skeleton.

According to the tenth aspect, scattering of light at the time of exposure can be made particularly difficult to occur, and a decrease in resolution can be made more difficult to occur. Thereby, when the coating film of the photosensitive resin composition is exposed and then developed to produce a film, the shape of the film can have higher resolution. Therefore, for example, when a film having holes is produced from a photosensitive resin composition by a photolithography method, it is possible to make it difficult to adversely affect the shape of the holes.

In the manufacturing method of the film of the eleventh aspect, in any one of the first to tenth aspects, the photosensitive resin composition further has a colorant (E).

According to the eleventh aspect, when exposing the coating film of the photosensitive resin composition, scattering in the coating film can be suppressed. Therefore, it is possible to make it more difficult to cause a decrease in resolution due to scattering of light. Thereby, when the coating film formed of the photosensitive resin composition is exposed to light and then developed to produce a film, the shape of the film can have a higher resolution. In this case, in producing a film having a hole, the shape of the hole can be made more distinct.

A printed wiring board of the twelfth aspect includes a conductive layer and an insulating layer overlapping the conductive layer. The insulating layer contains a film produced by the method for producing a film according to any one of claims 1 to 11.

According to the twelfth aspect, since the insulating layer has high resolution, the shape of the hole in the insulating layer can be clearly formed, whereby the printed wiring board can have excellent insulating reliability.

1: core material
2: insulating layer
3: conductive layer
31: first conductor wiring
4: coating
5: Non-exposed part
6: hole
7: interlayer insulating layer
8: second conductor wiring
9: hole plating
10: through hole
11: printed wiring board
40: film

Claims (12)

A step of forming a coating film on the substrate by disposing the photosensitive resin composition on the substrate;
Exposing the coating film to light emitted from a light source; And
Process of developing the coating film after the exposure with an alkali solution
As a method for producing a film comprising,
The photosensitive resin composition contains a carboxyl group-containing resin (A), an unsaturated compound (B) having at least one ethylenic unsaturated bond per molecule, a photopolymerization initiator (C), and an epoxy resin (D),
The light absorption spectrum of the photopolymerization initiator (C) has a first absorption band within a wavelength range of 350 nm or more and 370 nm or less, and a second absorption band that is longer than 370 nm and within a wavelength range of 415 nm or less,
The light irradiated to the coating film in the exposure step includes first light, second light, and third light,
The wavelength range of the first light is within the wavelength range of the first absorption band,
The wavelength range of the second light is within the wavelength range of the second absorption band,
The wavelength range of the third light is within a wavelength range of 305 nm or more and 325 nm or less,
For the area under the curve in the wavelength range of 200 nm to 500 nm in the spectrum of the light irradiated to the coating film, the area under the curve of the wavelength range shorter than 280 nm and up to 200 nm, and the wavelength range longer than 415 nm and up to 500 nm. The percentage of the sum of the areas under the curve is 5% or less,
Method for producing a film. The method of claim 1,
The second absorption band includes at least an absorption band that is longer than 400 nm and is within a wavelength range of 415 nm or less,
The second light includes at least light in a wavelength range longer than 400 nm and less than 415 nm. The method according to claim 1 or 2,
The light absorption spectrum of the photopolymerization initiator (C) further has a third absorption band within a wavelength range of 305 nm or more and 325 nm or less,
The wavelength range of the third light is within a wavelength range of the third absorption band. The method according to any one of claims 1 to 3,
The method for producing a film, wherein the maximum absorbance in the wavelength range of 305 nm or more and 325 nm or less with respect to the maximum absorbance in the wavelength range of 350 nm or more and 370 nm or less in the absorption spectrum of light of the coating film is 3 times or more. The method according to any one of claims 1 to 4,
The light source is at least one member selected from the group consisting of a metal halide lamp, a high-pressure mercury lamp, and an ultra-high pressure mercury lamp. The method according to any one of claims 1 to 5,
In the step of exposing, the light emitted from the light source is passed through an optical filter, and then the coating film is irradiated,
The optical filter cuts light in a wavelength range shorter than 280 nm and in a wavelength range of 200 nm or more, and light in a wavelength range longer than 415 nm and in a wavelength range of 500 nm or less. The method according to any one of claims 1 to 6,
The photopolymerization initiator (C) is at least one selected from the group consisting of an acylphosphine oxide photopolymerization initiator (C1), an α-aminoalkylphenone photopolymerization initiator (C2), and an oxime ester photopolymerization initiator (C3). To contain, the production method of the film. The method according to any one of claims 1 to 7,
The photopolymerization initiator (C) includes a hydrogen extraction type photopolymerization initiator (C4). The method according to any one of claims 1 to 8,
The carboxyl group-containing resin (A) includes a carboxyl group-containing resin having an ethylenically unsaturated group. The method according to any one of claims 1 to 9,
The photosensitive resin composition contains a component having a bisphenol fluorene skeleton. The method according to any one of claims 1 to 10,
The photosensitive resin composition further includes a colorant (E), a method for producing a film. A conductive layer and an insulating layer overlapping the conductive layer,
The insulating layer includes a film produced by the method for producing a film according to any one of claims 1 to 11,
Printed wiring board.

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