CN102331684A - Photosensitive element, method for forming resist pattern, method for manufacturing printed wiring board, and printed wiring board - Google Patents

Abstract

The invention relates to a photosensitive element, which is provided with a support film and a photosensitive resin composition layer formed on the support film, wherein the haze of the support film is 0.01-2.0%, and the total number of particles with the diameter of more than 5 μm and aggregates with the diameter of more than 5 μm contained in the support film is 5/mm²The photosensitive resin composition layer contains a binder polymer, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator, wherein the binder polymer has an acid value x of 60 to 130mgKOH/g, and a weight average molecular weightMw satisfies the relationship represented by the following formula . Mw is more than or equal to 10000 and less than 4000e^0.02x (I)。

Description

Photosensitive element, method for forming resist pattern, method for manufacturing printed wiring board, and printed wiring board

technical field

The present invention relates to a photosensitive element, a method for forming a resist pattern using the photosensitive element, a method for manufacturing a printed wiring board, and a printed wiring board. the

Background technique

Conventionally, in the field of manufacturing printed circuit boards and the field of precision metal processing, as resist materials for etching, plating, etc., layers made of photosensitive resin compositions (hereinafter referred to as "photosensitive layers"), A photosensitive element made of a support film and a protective film (refer to Japanese Patent Application Publication No. 01-221735, Japanese Patent Application Publication No. 02-230149, Japanese Patent Publication No. 56-040824, Japanese Patent Application Publication No. 55-501072, Japan JP-A-47-000469, JP-A-59-097138, JP-A-59-216141, JP-A-63-197942). the

The printed wiring board is manufactured, for example, as follows. First, after the protective film of the photosensitive element is peeled off from the photosensitive layer, the photosensitive layer is laminated on the conductive film of the circuit-forming substrate. Next, after pattern exposure is performed on the photosensitive layer, an unexposed portion (unexposed portion) of the photosensitive layer is removed with a developing solution to form a resist pattern. Then, based on the resist pattern, the conductive film is patterned to form a printed wiring board. the

In recent years, along with densification of printed wiring boards, the contact area between the substrate for circuit formation and the photosensitive layer which is a resist material has become smaller. Therefore, a photosensitive resin composition for forming a photosensitive layer is required to have excellent mechanical strength, chemical resistance, and flexibility in the process of performing etching or plating. In addition, excellent adhesion to the circuit-forming substrate and excellent definition in pattern formation are also required. For example, for the purpose of excellent plating resistance, a photosensitive resin composition containing a binder polymer having a specific structure has been disclosed (refer to Japanese Patent Laid-Open No. 2006-234995, Japanese Patent Laid-Open No. 2008-039978 ). the

Usually, when forming a resist film using a photosensitive element, after laminating a photosensitive layer on a substrate, the photosensitive layer is exposed through a support film. Therefore, in order to obtain high resolution in pattern formation, not only the photosensitive resin composition but also the properties of the support film to be used need to be considered. the

In order to obtain high resolution, for example, a method has been proposed, which reduces the haze of the support film by making one of the outermost surfaces of the support film contain inorganic or organic particles with an average particle size of about 0.01 to 5 μm, even through the support film. Higher resolution can also be achieved by exposing the photosensitive layer to the thin film (for example, refer to Japanese Patent No. 4014872, International Publication No. 08/093643, Japanese Patent Application Laid-Open No. 07-333853, and International Publication No. 00/079344). the

Contents of the invention

However, with the conventional method, although the decrease in the resolution of the photosensitive layer due to the influence of the support film and the defect in the shape of the cured resist film (resist film defect) can be suppressed to a certain extent, in order to To satisfy the characteristics required for recent photosensitive elements, further improvement is required. the

In addition, only by combining a conventional photosensitive resin composition with a support film described in Japanese Patent No. 4014872, International Publication No. 08/093643, Japanese Patent Application Laid-Open No. 07-333853, and International Publication No. 00/079344, There is a limit to achieving the developability and resolution required in recent years, and there is still room for further improvement. the

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a photosensitive element capable of sufficiently reducing resist film defects and having excellent developability and resolution in pattern formation. the

The present invention provides a photosensitive element comprising a support film and a photosensitive resin composition layer formed on the support film, wherein the support film has a haze of 0.01 to 2.0%, and the support film contains The total number of particles with a diameter of 5 μm or more and aggregates with a diameter of 5 μm or more is 5 pieces/mm ² or less, and the above-mentioned photosensitive resin composition layer contains a binder polymer, a photopolymerizable polymer having an ethylenically unsaturated bond. A neutral compound and a photopolymerization initiator, the acid value x of the binder polymer is 60 to 130 mgKOH/g, and the weight average molecular weight Mw satisfies the relationship shown in the following formula (I).

10000≤Mw＜4000e ^0.02x (I)

In formula (I), x represents the acid value of the binder polymer, and Mw represents the weight average molecular weight of the binder polymer. the

The photosensitive element according to the present invention can sufficiently reduce resist film defects by including the support film having the above-mentioned constitution. In addition, the photosensitive element according to the present invention can sufficiently reduce resist film defects by including the photosensitive resin composition layer having the above-mentioned structure, and has excellent developability and resolution in pattern formation. the

The photopolymerizable compound which has the said ethylenically unsaturated bond may contain the compound represented by following general formula (II). the

In the general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, Y represents an alkylene group with 2 to 6 carbon atoms, n ¹ and n ² represent positive integers, and n ¹ + n ² is 4 to 40, and a plurality of Ys present may be the same or different from each other.

By containing the compound represented by the said general formula (II), the balance of adhesiveness, sharpness, and chemical resistance becomes favorable, and also the resist pattern of an ultrafine line can be formed. the

In addition, the photosensitive element of the present invention has divalent groups represented by the following general formulas (III), (IV) and (V) through the binder polymer, so that the adhesiveness, clarity and peelability can be improved. The balance becomes better, and it becomes possible to form a resist pattern with extremely fine lines. the

In the general formulas (III), (IV) and (V), R ³ , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group with 1 to 4 carbon atoms, or an alkyl group with 1 to 4 carbon atoms. It is an alkoxy group, a hydroxyl group or a halogen atom of 1 to 3, R ⁷ represents an alkyl group with 1 to 10 carbon atoms, p represents an integer of 0 to 5, and when p is 2 or more, multiple R ⁵ that exist may be mutually same or different.

In addition, the photosensitive element of the present invention further has a divalent group represented by the following general formula (VI) through the binder polymer, thereby further improving the balance of adhesiveness, clarity, and peelability. the

In the general formula (VI), R ¹⁵ represents a hydrogen atom or a methyl group, R ¹⁶ represents an alkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a hydroxyl group or a halogen atom, and q represents 0 An integer of ˜5, when q is 2 or more, a plurality of R ¹⁶ present may be the same or different from each other.

Moreover, in the photosensitive element of this invention, a photoinitiator may contain 2,4,5- triaryl imidazole dimer. Thereby, the photosensitivity can be maintained, and the adhesiveness and definition are more excellent, and the resist pattern of an ultrafine line can be formed. the

Furthermore, the present invention provides a method for forming a resist pattern, which includes the steps of: laminating the photosensitive element on a circuit-forming substrate in the order of the photosensitive resin composition layer and the support film; Exposure process of irradiating active light to a predetermined portion of the photosensitive resin composition layer with a support film to form a photocured portion in the photosensitive resin composition layer; and development for removing the photosensitive resin composition layer other than the photocured portion process. According to the method for forming a resist pattern of the present invention, since the above-mentioned photosensitive element of the present invention is used, it is possible to efficiently obtain a resist pattern with extremely fine lines. the

In addition, the present invention provides a method of manufacturing a printed wiring board having a step of etching or plating a circuit-forming substrate on which a resist pattern is formed, and a printed wiring board manufactured by the above-mentioned manufacturing method. According to the method of manufacturing a printed wiring board of the present invention, since the method of forming a resist pattern using the photosensitive element of the present invention is used, a high-density printed wiring board having a wiring pattern of extremely fine lines can be obtained. the

According to the photosensitive element of the present invention, it is possible to provide a photosensitive element capable of sufficiently reducing resist film defects and having excellent developability and resolution in pattern formation. the

Description of drawings

FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. the

FIG. 2 is a polarizing micrograph obtained by observing the surface of a support film having particles having a diameter of 5 μm or more. the

3 is a scanning micrograph of a resist pattern formed using a photosensitive element including a photosensitive layer on a support film having a plurality of particles having a diameter of 5 μm or more. the

Detailed ways

Hereinafter, preferred embodiments of the present invention will be described in detail while referring to the drawings as necessary. It should be noted that in the drawings, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios in the drawings are not limited to the illustrated ratios. In addition, "(meth)acrylate" in this specification means "acrylate" and the corresponding "methacrylate". Similarly, "(meth)acryl" refers to "acryl" and its corresponding "methacryl", and "(meth)acryl" refers to "acryl" and its corresponding "methacryl". ". the

FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. A photosensitive element 1 shown in FIG. 1 is composed of a support film 10 and a photosensitive layer (photosensitive resin composition layer) 20 . The photosensitive layer 20 is provided on the first main surface 12 of the support film 10 . Moreover, the support film 10 has the 2nd main surface 14 on the side opposite to the 1st main surface 12. As shown in FIG. the

(support film)

The haze of the support film 10 is 0.01 to 2.0%, and the total number of particles with a diameter of 5 μm or more and aggregates with a diameter of 5 μm or more (hereinafter simply referred to as “particles, etc.”) contained in the support film 10 is 5 pieces/mm ² or less. Here, the particles and the like having a diameter of 5 μm or more contained in the support film 10 include particles and the like protruding from the first main surface 12 and the second main surface 14 of the support film 10 and particles and the like existing inside the film 10. both. In addition, particles having a diameter of 5 μm or more include aggregates of primary particles having a diameter of 5 μm or more and primary particles having a diameter of less than 5 μm.

From the viewpoint of reducing partial chipping of the resist film after exposure and development, the total number of particles with a diameter of 5 μm or more is preferably 5 particles/mm ² or less, more preferably 3 particles/mm ² or less, still more preferably 1 particle / ^mm2 or less. If a photosensitive element in which the total number of such particles exceeds 5 pieces/ ^mm2 is used in the manufacture of a printed wiring board, it will cause opening defects during etching and short-circuit defects during plating, and there are defects in printed wiring boards. Tendency to decrease manufacturing yield.

In addition, even if many particles with a diameter of less than 5 μm are contained in the support film 10, the effect on light scattering is not large. The main reason is that, in the exposure process described later, when the photosensitive layer 20 is irradiated with light, the photocuring reaction of the photosensitive layer 20 is not only carried out in the light irradiation part, but also in the lateral direction (perpendicular to the light irradiation direction) where no light is directly irradiated. directions) also, although only some. Therefore, it can be considered that when the particle size is small, the photocuring reaction directly below the particle proceeds sufficiently, but as the particle size becomes larger, the photocuring reaction directly below the particle does not proceed sufficiently, so a gap in the resist film (resist film) occurs. membrane defect). the

Here, the particles with a diameter of 5 μm or more contained in the support film 10 are caused by components constituting the support film 10 such as polymer gels, monomers as raw materials, catalysts used in production, and as needed. Agglomerates formed by the aggregation of inorganic or organic particles contained in the film, swelling caused by lubricants and adhesives when coating a lubricant-containing layer on the film, particles contained in the film with a diameter of 5 μm or more produced by particles, etc. In order to reduce the total number of particles having a diameter of 5 μm or more to 5 particles/mm ² or less, it is only necessary to selectively use particles with a smaller particle diameter or particles with excellent dispersibility among these particles.

The total number of particles having a diameter of 5 μm or more can be measured using a polarizing microscope. In addition, an aggregate formed by aggregating primary particles having a diameter of 5 μm or more and primary particles having a diameter of less than 5 μm was counted as one. FIG. 2 is a polarizing micrograph obtained by observing the surface of a support film having particles having a diameter of 5 μm or more. In FIG. 2 , a circled portion represents an example of a portion corresponding to particles having a diameter of 5 μm or more. 3 is a scanning micrograph of a resist pattern formed using a photosensitive element provided with a photosensitive layer on a support film having a large number of particles having a diameter of 5 μm or more. The part surrounded by a frame shows the place where the resist film is missing. In this way, if a large number of particles with a diameter of 5 µm or more are present on the surface of the support film, resist film defects will occur. the

The material of the support film 10 is not particularly limited as long as the total number of particles with a diameter of 5 μm or more is 5 particles/mm ^{2 or} less. Examples of the support film 10 include one or more materials selected from the group consisting of polyesters such as polyethylene terephthalate (hereinafter referred to as "PET"), and polyolefins such as polypropylene and polyethylene. Film of resin material.

The supporting film 10 may be a single layer or a multilayer. For example, when using a double-layer support film composed of two layers, it is preferable to use a double-layer film in which a resin layer containing fine particles is laminated on one side of a biaxially oriented polyester film as the support film, and the above-mentioned The photosensitive layer 20 is formed on the surface opposite to the surface of the resin layer containing fine particles. Moreover, as the support film 10, the multilayer support film which consists of 3 layers (for example, A layer/B layer/A layer) can also be used. The structure of the multilayer support film is not particularly limited, and it is preferable that the outermost layer (layer A when the above-mentioned three-layer structure) is a resin layer containing fine particles from the standpoint of smoothness of the film. the

Since the conventional two-layer support film is produced by coating a resin layer with particles on a biaxially oriented polyester film, the resin layer containing particles is easy to peel off during lamination of the photosensitive layer, and the above-mentioned resin layer after peeling may be It adheres to the photosensitive layer and becomes the cause of defects. Therefore, in this embodiment, it is preferable to use a multilayer support film formed of three layers including a resin layer containing fine particles and a biaxially oriented polyester film. the

In this embodiment, a multilayer support film having a resin layer containing such fine particles while adjusting the total number of particles having a diameter of 5 μm or more contained in the support film 10 to 5 particles/mm ² or less is particularly suitable. Thereby, the slipperiness of a film can be improved, and the suppression of light scattering at the time of exposure can be achieved in a well-balanced and higher level. The average particle diameter of the microparticles is preferably 0.1 to 10 times, more preferably 0.2 to 5 times, the layer thickness of the resin layer containing the microparticles. When the average particle size is less than 0.1 times, smoothness tends to be poor, and when it exceeds 10 times, there is a tendency that the photosensitive layer tends to generate unevenness particularly easily.

The fine particles are preferably contained in an amount of 0.01 to 50% by mass based on the mass of the resin in the fine particle-containing resin layer. In addition, as the above-mentioned fine particles, for example, fine particles generated during polymerization by various nucleating agents, aggregates, fine particles of silica (agglomerated silica, etc.), fine particles of calcium carbonate, fine particles of alumina, titanium oxide particles, etc., can be used. Inorganic particles such as fine particles and barium sulfate particles, organic particles such as cross-linked polystyrene resin particles, acrylic resin particles and imide resin particles, and mixtures thereof. the

In a multilayer support film having three or more layers, one or more intermediate layers sandwiched by the outermost layers containing particles may or may not contain the above-mentioned particles. From the standpoint of clarity, it is preferable not to contain the above-mentioned particles. particle. When the intermediate layer contains the aforementioned fine particles, the content in the intermediate layer is preferably 1/3 or less of that in the outermost layer, more preferably 1/5 or less. the

From the viewpoint of excellent clarity, the layer thickness of the resin layer containing the fine particles is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, particularly preferably 0.1 to 2 μm. In addition, the surface of the outermost layer that does not face the intermediate layer preferably has a static friction coefficient of 1.2 or less. When the coefficient of static friction exceeds 1.2, wrinkles are likely to be introduced during film production and photosensitive element production, and since static electricity is likely to be generated, impurities tend to be easily attached. In the present embodiment, the coefficient of static friction can be measured in accordance with ASTM D1894. the

In addition, in order to adjust the total number of particles having a diameter of 5 μm or more contained in the support film 10 to 5 particles/mm ² or less, the particle diameter of the particles contained in the particle-containing resin layer is preferably less than 5 μm. In addition, in order to further reduce light scattering during exposure, it is preferable to appropriately adjust the layer thickness of the resin layer containing the fine particles according to the particle diameter of the fine particles.

Moreover, the support film 10 may contain an antistatic agent etc. as needed within the range which does not impair the photosensitivity of the photosensitive layer 20. the

From the viewpoint of excellent photosensitivity and clarity, the haze of the support film 10 is preferably 2.0% or less, more preferably 1.5% or less, still more preferably 1.0% or less, particularly preferably 0.5% or less. Here, "haze" refers to degree of cloudiness (暗り度). The haze of the support film 10 in this embodiment refers to the value measured using a commercially available haze meter (nephelometer) according to the method specified in JIS K 7105. The said haze can be measured with the commercially available turbidity meter of NDH-1001DP (made by Nippon Denshoku Industries Co., Ltd., brand name), for example. The lower limit of the haze is preferably close to zero from the viewpoint of excellent photosensitivity and clarity, but from the standpoint of windability when producing the support film 10, the haze is preferably set to 0.01 or more. When the above-mentioned haze is less than 0.01, since the support film does not contain fine particles or the like, there is a tendency for trouble to occur in winding up when the support film is produced, or wrinkles to occur. the

The thickness of the support film 10 is preferably 5 to 40 μm, more preferably 8 to 35 μm, particularly preferably 10 to 30 μm, even more preferably 12 to 25 μm. When the thickness is less than 5 μm, the support film tends to be easily broken when the support film is peeled off from the photosensitive element. In addition, when the thickness exceeds 40 μm, the resolution tends to decrease, and the low cost tends to be insufficient. the

In addition, as the support film 10 , a film that can be used as the support film 10 of the photosensitive element 1 can be obtained from commercially available general industrial films, and can be used after being processed appropriately. Examples of commercially available general industrial films that can be used as the support film 10 include "QS-48" (trade name, manufactured by Toray Co., Ltd.), which is a three-layer PET film containing fine particles in the outermost layer. the

(photosensitive layer)

The photosensitive layer 20 is a layer formed of a photosensitive resin composition. The photosensitive resin composition constituting the photosensitive layer 20 contains (A) a binder polymer (hereinafter referred to as "(A) component"), (B) a photopolymerizable compound having an ethylenically unsaturated bond, and (C) Photoinitiator (henceforth "(C)component"). Each of the above components will be described in detail below. the

(adhesive polymer)

The binder polymer (A) component can be used without particular limitation as long as the acid value x is 60 to 130 mgKOH/g and the weight average molecular weight Mw satisfies the relationship represented by the following formula (I). the

10000≤Mw＜4000e ^0.02x (I)

The relationship between the acid value x of the binder polymer and the weight-average molecular weight Mw satisfies the relationship of the above formula, so that various properties after curing (developability, adhesion, clarity, shape of the side surface of the resist film, and resistance to corrosion) can be improved. etch film defect) excellent photosensitive resin composition. the

The acid value x of the binder polymer is 60 to 130 mgKOH/g, but from the perspective of satisfying the above-mentioned characteristics in a balanced manner, it is preferably 65 to 130 mgKOH/g, more preferably 90 to 130 mgKOH/g, and even more preferably 110 to 130 mgKOH/g. 130mgKOH/g. the

As an indicator similar to the acid value (the number of mg of potassium hydroxide (KOH) required to neutralize 1 g of a sample), acid equivalent (the number of g of a polymer having 1 equivalent of carboxylic acid) can be cited, and they can be compared with each other. Conversion. the

The weight-average molecular weight of the binder polymer satisfies the relationship represented by the above formula (I). The lower limit of the Mw of the binder polymer is 10,000 or more, preferably 15,000 or more, more preferably 20,000 or more, and still more preferably 25,000 or more from the viewpoint of excellent toughness of the photosensitive layer. In addition, the upper limit of the Mw of the binder polymer is 4000e ^0.02x or less, preferably 90% or less of 4000e ^0.02x , more preferably 80% or less, and further Preferably it is 70% or less. In addition, the said weight average molecular weight was measured by gel permeation chromatography (it will be described as "GPC" hereafter), and the value converted into standard polystyrene was used, and the measurement conditions were the same as the conditions described in the Example mentioned later.

Examples of the binder polymer include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenolic resins. Among these, acrylic resins are preferable from the standpoint of alkali developability. These can be used individually by 1 type or in combination of 2 or more types. the

The binder polymer can be produced, for example, by radically polymerizing a polymerizable monomer. Examples of polymerizable monomers include polymerizable styrene derivatives such as styrene, vinyltoluene, p-methylstyrene, p-chlorostyrene, α-methylstyrene, and α-methylstyrene derivatives. , acrylamide, acrylonitrile and vinyl alcohol esters such as vinyl n-butyl ester, alkyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylate Base) dimethylaminoethyl acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate and 2, (meth)acrylates such as 2,3,3-tetrafluoropropyl (meth)acrylate, (meth)acrylic acid, α-bromo(meth)acrylic acid, α-chloro(meth)acrylic acid, β- (meth)acrylic acid derivatives such as furyl (meth)acrylic acid and β-styryl (meth)acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, and maleic acid Maleic acid derivatives such as monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. These can be used individually by 1 type, or in combination of 2 or more types. the

The binder polymer preferably contains structural units represented by the following general formulas (III), (IV) and (V) from the standpoint of a balance between resistance to developing solution (developing solution resistance) and releasability. Moreover, there exists a tendency for adhesiveness and clarity to improve by improvement of developing solution tolerance. the

In the general formulas (III), (IV) and (V), R ³ , R ⁴ and R ⁶ each independently represent a hydrogen atom or a methyl group, and R ⁵ represents an alkyl group with 1 to 4 carbon atoms, or an alkyl group with 1 to 4 carbon atoms. It is an alkoxyl group, a hydroxyl group or a halogen atom of 1 to 3, R ⁷ represents an alkyl group with 1 to 6 carbon atoms, p represents an integer of 0 to 5, and when p is 2 or more, multiple R ⁵ that exist may be mutually same or different.

The structural unit represented by the above general formula (III) is a (meth)acrylic acid-based structural unit, preferably a methacrylic acid-based structural unit (R ³ =methyl).

When the (A) binder polymer contains the structural unit represented by the above-mentioned general formula (III), its content ratio is based on the total solid content of the (A) binder polymer as a copolymer, from the development From the viewpoint of excellent properties and releasability, it is preferably at least 10% by mass, more preferably at least 15% by mass, and even more preferably at least 20% by mass. In addition, from the viewpoint of excellent adhesiveness and clarity, it is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 35% by mass or less. the

The structural unit represented by the above general formula (IV) is based on styrene (R ⁴ =hydrogen atom, p=0), styrene derivatives, α-methylstyrene (R ⁴ =methyl, p=0) and Structural unit of α-methylstyrene derivatives. In this embodiment, "styrene derivatives" and "α-methylstyrene derivatives" mean that the hydrogen atom on the benzene ring of styrene and α-methylstyrene is replaced by a substituent R ⁵ (the number of carbon atoms is Alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 3 carbon atoms, hydroxyl group, halogen atom). Examples of the above-mentioned styrene derivatives include methylstyrene, ethylstyrene, tert-butylstyrene, methoxystyrene, ethoxystyrene, hydroxystyrene and chlorostyrene, and para-position A structural unit substituted with R ⁵ . Examples of the α-methylstyrene derivatives include compounds in which the hydrogen atom at the α-position of the vinyl group is substituted with a methyl group among the above-mentioned styrene derivatives.

When the (A) binder polymer contains a structural unit represented by the above-mentioned general formula (IV), its content ratio is based on the total solid content of the (A) binder polymer as a copolymer, from From the viewpoint of excellent adhesion and clarity, it is preferably at least 3% by mass, more preferably at least 10% by mass, still more preferably at least 15% by mass, and particularly preferably at least 20% by mass. In addition, from the viewpoint of excellent peelability and flexibility of the cured resist film, it is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, particularly preferably 45% by mass or less . the

The structural unit represented by the said general formula (V) is a structural unit based on an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include compounds in which R ⁷ is an alkyl group having 1 to 12 carbon atoms in the general formula (V). The alkyl group having 1 to 12 carbon atoms may be linear or branched, and may have a substituent such as a hydroxyl group, an epoxy group, or a halogen atom. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, ( Butyl methacrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, (meth)acrylate base) 2-ethylhexyl acrylate and their structural isomers. From the standpoint of improving the resolution and shortening the peeling time, among them, ^R7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms without a substituent , more preferably methyl.

When the (A) binder polymer contains a structural unit represented by the above-mentioned general formula (V), its content ratio is based on the total solid content of the (A) binder polymer as a copolymer. From the viewpoint of excellent performance, it is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, particularly preferably 15% by mass or more. In addition, from the viewpoint of excellent sharpness, it is preferably 55% by mass or less, more preferably 50% by mass or less, still more preferably 45% by mass or less, particularly preferably 40% by mass or less. the

In addition, the (A) binder polymer preferably further includes a structural unit represented by the following general formula (VI) from the standpoint of adhesiveness, sharpness, and peelability. the

In the general formula (VI), R ¹⁵ represents a hydrogen atom or a methyl group, R ¹⁶ represents an alkyl group with 1 to 4 carbon atoms, an alkoxy group with 1 to 3 carbon atoms, a hydroxyl group or a halogen atom, and q represents 0 An integer of ~5, when q is 2 or more, a plurality of R ¹⁶ present may be the same or different from each other.

The structural unit represented by the above general formula (VI) is a structural unit derived from benzyl (meth)acrylate and benzyl (meth)acrylate derivatives. Examples of the benzyl (meth)acrylate derivatives include 4-methylbenzyl (meth)acrylate, 4-ethylbenzyl (meth)acrylate, 4-tert-butyl (meth)acrylate Benzyl ester, 4-methoxybenzyl (meth)acrylate, 4-ethoxybenzyl (meth)acrylate, 4-hydroxybenzyl (meth)acrylate, 4-chlorobenzyl (meth)acrylate . From the standpoint of maintaining developability, etching resistance, plating resistance, and flexibility of the cured film, the structural unit represented by the above general formula (VI) is particularly preferably based on benzyl (meth)acrylate (when q=0) Structural units. the

When the (A) binder polymer contains a structural unit represented by the above-mentioned general formula (VI), its content ratio is based on the total solid content of the (A) binder polymer as a copolymer, from the binder From the viewpoint of excellent adhesion, it is preferably at least 5% by mass, more preferably at least 10% by mass, and still more preferably at least 20% by mass. In addition, from the viewpoint of excellent peelability and flexibility of the cured resist film, it is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, particularly preferably 45% by mass or less . the

These binder polymers can be used individually by 1 type or in combination of 2 or more types. As a combination of binder polymers used in combination of two or more, for example, two or more binder polymers composed of different copolymer components (containing different structural units as constituents), different weight Two or more binder polymers having an average molecular weight, and two or more binder polymers having different degrees of dispersion. In addition, a polymer having a multimodal molecular weight distribution described in JP-A-11-327137 can also be used as the binder polymer. the

Moreover, when developing with an organic solvent in the developing process mentioned later, it is preferable to prepare a small amount of polymerizable monomer which has a carboxyl group. In addition, the binder polymer may have a photosensitive functional group as needed. the

Based on 100 parts by mass of the total amount of component (A) and component (B) described later, the compounding amount of component (A) that is, the binder polymer is preferably 40 to 70 parts by mass, more preferably 45 to 65 parts by mass parts, more preferably 50 to 60 parts by mass. When the amount is less than 40 parts by mass, the photosensitive layer cured by exposure tends to be brittle, and when it exceeds 70 parts by mass, the resolution and photosensitivity tend to be insufficient. the

(Photopolymerizable compound having an ethylenically unsaturated bond) 

(B) It is preferable that the photopolymerizable compound which has an ethylenically unsaturated bond as a component contains the compound represented by following general formula (II). the

In the above general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, preferably a methyl group. Y represents an alkylene group having 2 to 6 carbon atoms. n ¹ and n ² each represent a positive integer, n ¹ + n ² is an integer of 4 to 40, preferably an integer of 6 to 34, more preferably an integer of 8 to 30, even more preferably an integer of 8 to 28, especially It is preferably an integer of 8-20, extremely preferably an integer of 8-16, and most preferably an integer of 8-12. When the value of n ¹ +n ² is less than 4, the compatibility with the binder polymer decreases, and there is a tendency for the photosensitive element to be easily peeled off when the circuit-forming substrate is laminated. When the value of n ¹ +n ² When it exceeds 40, the hydrophilicity of the photosensitive layer increases, the resist film tends to peel off easily at the time of image development, and there exists a tendency for plating resistance to fall. In addition, a plurality of Y present in the molecule may be the same as or different from each other.

Examples of the above-mentioned alkylene group having 2 to 6 carbon atoms include ethylene, propylene, isopropylene, butylene, pentylene and hexylene. Among these, ethylene and isopropylene are preferable, and ethylene is more preferable from the viewpoint of improving clarity and plating resistance. the

In addition, the aromatic ring in the above general formula (II) may have a substituent. Examples of these substituents include a halogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, and a phenacyl group. , amino, alkylamino with 1 to 10 carbon atoms, dialkylamino with 2 to 20 carbon atoms, nitro, cyano, carbonyl, mercapto, alkylmercapto with 1 to 10 carbon atoms, Allyl group, hydroxyl group, hydroxyalkyl group with 1 to 20 carbon atoms, carboxyl group, carboxyalkyl group with 1 to 10 carbon atoms in the alkyl group, acyl group with 1 to 10 carbon atoms in the alkyl group, carbon atom Alkoxy group with 1 to 20 carbon atoms, alkoxycarbonyl group with 1 to 20 carbon atoms, alkylcarbonyl group with 2 to 10 carbon atoms, alkenyl group with 2 to 10 carbon atoms, N-alkylcarbamoyl groups of 2 to 10, groups containing heterocycles, and aryl groups substituted with these substituents. The above-mentioned substituents may form a condensed ring, and hydrogen atoms in these substituents may be substituted with the above-mentioned substituents such as halogen atoms. In addition, when the number of substituents is two or more, the two or more substituents may be the same as or different from each other. the

Examples of the compound represented by the general formula (II) above include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4 -((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane and 2,2- Bisphenol A-based (meth)acrylate compounds such as bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane. the

Specific examples of the compound represented by the above general formula (II) include, for example, EO-modified bismuths in which R ¹ and R ² are hydrogen atoms, Y is ethylene, and n ¹ +n ² =10 (average value). Phenol A diacrylate (manufactured by Hitachi Chemical Industries, Ltd., brand name: FA-321M).

(B) The balance of the blending of the hydrophilic component and the hydrophobic component in the component affects clarity, adhesiveness, peeling properties after curing, and the like. From such a viewpoint, in order to obtain a photosensitive element excellent in resolution, adhesiveness, peeling property after hardening, etc., it is preferable to contain polyalkylene glycol di(meth)acrylate as (B) component. As polyalkylene glycol di(meth)acrylate, the compound represented by following general formula (VII), (VIII) or (IX), for example is preferable. the

In the general formula (VII), R ⁸ and R ⁹ each independently represent a hydrogen atom or a methyl group, EO represents an oxyethylene group, PO represents a propylene oxide group, s ¹ represents an integer of 1 to 30, r ¹ and r ² represents an integer of 0 to 30, and r ¹ +r ² (average value) represents an integer of 1 to 30.

In the general formula (VIII), R ¹⁰ and R ¹¹ each independently represent a hydrogen atom or a methyl group. EO represents an oxyethylene group, PO represents an oxypropylene group, r ³ represents an integer of 1 to 30, s ² and s ³ represent an integer of 0 to 30, and s ² +s ³ (average value) is 1 to 30 integer.

In the general formula (IX), R ¹² and R ¹³ each independently represent a hydrogen atom or a methyl group, preferably a methyl group. EO represents an oxyethylene group, and PO represents an oxypropylene group. r ⁴ represents an integer of 1-30, and s ⁴ represents an integer of 1-30.

In the above general formulas (VII), (VIII) and (IX), when there are multiple structural units of oxyethylene (EO, oxyethylene units) and structural units of oxypropylene (PO, oxypropylene In the case of oxyethylene units), a plurality of oxyethylene units and oxypropylene units may exist continuously in blocks or randomly. Furthermore, when the oxypropylene unit is a structural unit of an oxyisopropylene group, the secondary carbon of the propylene group may be bonded to the oxygen atom, or the primary carbon may be bonded to the oxygen atom. the

The total number of oxyethylene units (r ¹ +r ² , r ³ and r ⁴ ) in the above general formulas (VII), (VIII) and (IX) is each independently an integer of 1 to 30, preferably 4 The above integer is more preferably an integer of 5 or more. In addition, from the viewpoint of excellent tensile reliability and resist film shape, it is preferably an integer of 10 or less, more preferably an integer of 9 or less, and still more preferably an integer of 8 or less.

The total number of oxypropylene units (s ¹ , s ² +s ³ and s ⁴ ) in the above general formulas (VII), (VIII) and (IX) are each independently an integer of 1 to 30, but from the perspective of clarity From the viewpoint of excellent low sludge property (sludge), it is preferably an integer of 5 or more, more preferably an integer of 8 or more, and still more preferably an integer of 10 or more. In addition, from the viewpoint of excellent clarity and low sludge property, it is preferably an integer of 20 or less, more preferably an integer of 16 or less, and still more preferably an integer of 14 or less.

Specific examples of the compound represented by the above general formula (VII) include ethylene in which R ⁸ and R ⁹ are methyl groups, r ¹ +r ² =6 (average value), and s ¹ =12 (average value). Base compound (manufactured by Hitachi Chemical Industries, Ltd., brand name: FA-023M).

Specific examples of the compound represented by the above general formula (VIII) include ethylene in which R ¹⁰ and R ¹¹ are methyl groups, r ³ =6 (average value), and s ² +s ³ =12 (average value). Base compound (manufactured by Hitachi Chemical Industries, Ltd., brand name: FA-024M).

Specific examples of the compound represented by the above general formula (IX) include vinyl compounds in which R ¹² and R ¹³ are hydrogen atoms, r ⁴ =1 (average value), and s ⁴ =9 (average value) ( Shin-Nakamura Chemical Co., Ltd., NK Ester HEMA-9P).

Moreover, these can be used individually by 1 type or in combination of 2 or more types. the

Moreover, as (B) component, it is preferable to contain a urethane monomer, such as a (meth)acrylate compound which has a urethane bond, from a viewpoint of being excellent in tension|tensile property (tenting). the

Examples of the urethane monomer include (meth)acrylic monomers having a hydroxyl group at the β position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1 , Addition reactants of diisocyanate compounds such as 6-hexamethylene diisocyanate, tris((meth)acryloyloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO modified urethane Ester di(meth)acrylate, and EO, PO modified urethane di(meth)acrylate. In addition, the EO-modified compound has a block structure of ethylene oxide. In addition, the PO-modified compound has a block structure of oxypropylene. As EO modified urethane di(meth)acrylate, the Shin-Nakamura Chemical Industry Co., Ltd. make, brand name "UA-11" is mentioned, for example. Moreover, as EO and PO modified urethane di(meth)acrylate, the Shin-Nakamura Chemical Industry Co., Ltd. make, brand name "UA-13" is mentioned, for example. These can be used individually by 1 type or in combination of 2 or more types. the

Moreover, it is preferable that (B) component contains the compound obtained by making polyhydric alcohol and (alpha), (beta)-unsaturated carboxylic acid react from a viewpoint of being excellent in adhesiveness, sharpness, and peelability. Examples of these compounds include trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO modified trimethylolpropane tri(meth)acrylate, EO, PO modified trimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate )Acrylate. As EO modified trimethylolpropane tri(meth)acrylate, the Sartomer company make, a brand name "SR-454" is mentioned, for example. These can be used individually by 1 type or in combination of 2 or more types. the

It is preferable that (B) component also contains the photopolymerizable compound which has one ethylenically unsaturated bond from a viewpoint of being excellent in adhesiveness, clarity, and peelability. As a photopolymerizable compound which has one ethylenically unsaturated bond, it is preferable to contain the compound represented by following general formula (X). the

In the general formula (X), R ¹⁴ is a hydrogen atom or a methyl group, preferably a hydrogen atom. Z has the same meaning as Y in the above general formula (II), and is preferably ethylene. k represents an integer of 4 to 20, and is preferably an integer of 5 to 18, more preferably an integer of 6 to 12, and still more preferably an integer of 6 to 10 from the viewpoint of developability. In addition, the aromatic ring in the above general formula (X) may have a substituent, and examples of these substituents include the same substituents as those for the aromatic ring in the above general formula (II).

Specific examples of the compound represented by the general formula (X) include nonylphenoxypolyethyleneoxy (meth)acrylate, nonylphenoxypolypropyleneoxy (methyl) ) acrylate, butylphenoxypolyethyleneoxy(meth)acrylate and butylphenoxypolypropyleneoxy(meth)acrylate. the

Examples of the nonylphenoxy polyethyleneoxy (meth)acrylate include nonylphenoxy tetraethyleneoxy (meth)acrylate, nonylphenoxy pentaethylene Nonyloxy(meth)acrylate, nonylphenoxyhexaethyleneoxy(meth)acrylate, nonylphenoxyheptaethyleneoxy(meth)acrylate, nonylphenoxy Octaethyleneoxy (meth)acrylate, Nonylphenoxy nonaethyleneoxy (meth)acrylate, Nonylphenoxy decaethyleneoxy (meth)acrylate, Nonylphenoxy undecaethyleneoxy (meth)acrylate and nonylphenoxy dodecylethyleneoxy (meth)acrylate. the

Examples of the butylphenoxy polyethyleneoxy (meth)acrylate include butylphenoxy tetraethyleneoxy (meth)acrylate, butylphenoxy pentaethylene oxy (meth)acrylate, butylphenoxyhexaethyleneoxy (meth)acrylate, butylphenoxyheptaethyleneoxy (meth)acrylate, butylphenoxy Octaethyleneoxy (meth)acrylate, Butylphenoxy nonaethyleneoxy (meth)acrylate, Butylphenoxy decaethyleneoxy (meth)acrylate and Butylphenoxyundecaethyleneoxy(meth)acrylate. Moreover, these can be used individually by 1 type or in combination of 2 or more types. the

(B) The photopolymerizable compound which has an ethylenically unsaturated bond other than the above may be contained in a component. Examples of other (B) photopolymerizable compounds include compounds obtained by reacting glycidyl group-containing compounds with α,β-unsaturated carboxylic acids, phthalic acid-based compounds, and (meth)acrylic acid alkyl groups. ester. the

Examples of the above-mentioned phthalic acid-based compounds include γ-chloro-β-hydroxypropyl-β′-(meth)acryloyloxyethyl-phthalate and β-hydroxyalkyl-β '-(Meth)acryloyloxyalkyl-phthalates. These can be used individually by 1 type or in combination of 2 or more types. the

Based on 100 parts by mass of the total amount of component (A) and component (B), the compounding amount of component (B), that is, a photopolymerizable compound having an ethylenically unsaturated bond, is preferably 30 to 60 parts by mass, more preferably 30 to 60 parts by mass. 35 to 55 parts by mass, more preferably 40 to 50 parts by mass. When the amount is less than 30 parts by mass, the resolution and photosensitivity tend to be insufficient, and when it exceeds 60 parts by mass, the photosensitive layer cured by exposure tends to become brittle. the

(photopolymerization initiator)

From the viewpoint of being excellent in photosensitivity and adhesiveness, it is preferable that the photopolymerization initiator which is the component (C) contains a 2,4,5-triaryl imidazole dimer. Examples of 2,4,5-triaryl imidazole dimers include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimers, 2-(o-bromophenyl)-4, 5-diphenylimidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole Dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis(methoxyphenyl)imidazole di polymer, 2-(o-chlorophenyl)-4,5-bis(p-fluorophenyl)imidazole dimer, 2-(2,6-dichlorophenyl)-4,5-diphenylimidazole dimer polymer, 2-(o-chlorophenyl)-4,5-bis(p-fluorophenyl)imidazole dimer, 2-(o-bromophenyl)-4,5-bis(p-iodophenyl)imidazole di Polymer, 2-(o-chlorophenyl)-4,5-bis(p-chloronaphthyl)imidazole dimer, 2-(o-chlorophenyl)-4,5-bis(p-chlorophenyl)imidazole di Polymer, 2-(o-bromophenyl)-4,5-bis(o-chloro-p-methoxyphenyl)imidazole dimer, 2-(o-chlorophenyl)-4,5-bis(o, p-dichlorophenyl) imidazole dimer, 2-(o-chlorophenyl)-4,5-bis(o, p-dibromophenyl) imidazole dimer, 2-(o, m-dichlorophenyl) -4,5-bis(p-chloronaphthyl)imidazole dimer, 2-(o, m-dichlorophenyl)-4,5-diphenylimidazole dimer, 2-(o, p-dichlorophenyl base)-4,5-bis(m-methoxyphenyl)imidazole dimer, 2,4-bis(p-methoxyphenyl)-5-phenylimidazole dimer, 2-(2,4 -Dimethoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methylmercaptophenyl)-4,5-diphenylimidazole dimer, 2-(p-bromobenzene base)-4,5-diphenylimidazole dimer, 2-(o-bromophenyl)-4,5-bis(o-, p-dichlorophenyl)imidazole dimer, 2-(m-bromophenyl )-4,5-diphenylimidazole dimer, 2-(m-, p-dibromophenyl)-4,5-diphenylimidazole dimer, 2,2'-bis(o-bromophenyl) -4,4',5,5'-Tetrakis(p-chloro-p-methoxyphenyl) imidazole dimer, 2-(o-chlorophenyl)-4,5-bis(o,p-dichlorophenyl ) imidazole dimer, 2-(o-chlorophenyl)-4,5-bis(o-, p-dibromophenyl) imidazole dimer, 2-(o-bromophenyl)-4,5-bis(o- , p-dichlorophenyl) imidazole dimer and 2,4,5-tris (o, p-dichlorophenyl) imidazole dimer. Among these, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer is preferable from the viewpoint of further improving adhesiveness and photosensitivity. the

In addition, in the 2,4,5-triaryl imidazole dimer, the substituents of the aryl groups of the two 2,4,5-triaryl imidazoles can be the same to provide a symmetrical compound, or different to provide an asymmetric compound . the

When the component (C) contains 2,4,5-triaryl imidazole dimer, the content ratio thereof is preferably 70 to 100% by mass, more preferably 85 to 100% by mass, based on the total amount of the component (C). Mass % is more preferably 90 to 100 mass %, particularly preferably 93 to 100 mass %. By containing the 2,4,5-triaryl imidazole dimer in this ratio, the photosensitive element of this embodiment will have more excellent adhesiveness and photosensitivity. the

Moreover, as a photoinitiator which is a component (C), other than the said 2,4,5- triaryl imidazole dimer can also be used. As other photopolymerization initiators, for example, aromatic ketones, p-aminophenyl ketones, quinones, benzoin ether compounds, benzoin compounds, benzil derivatives, acridine derivatives, aromatic ketones, Soybein-based compounds, oxime esters, N-aryl-α-amino acid compounds, aliphatic polyfunctional thiol compounds, acylphosphine oxides, thioxanthones, and tertiary amine compounds may be used in combination. the

The (C) photopolymerization initiator of this embodiment preferably contains the above-mentioned aromatic ketones in addition to the 2,4,5-triaryl imidazole dimer, and particularly preferably contains N,N'-tetraethyl-4, 4'-Diaminobenzophenone (Michlerone). the

Based on 100 parts by mass of the total amount of components (A) and (B), the compounding amount of component (C), that is, a photopolymerization initiator, is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, and particularly preferably It is 0.5-5 mass parts. When the compounding amount is less than 0.1 parts by mass, there is a tendency that the photosensitivity becomes insufficient, and when it exceeds 20 parts by mass, there is an increase in light absorption on the surface of the photosensitive resin composition during exposure and internal photocuring becomes difficult. Inadequate tendency. the

In addition, the photosensitive resin composition may contain, if necessary, a photopolymerizable compound (oxetane compound, etc.) having at least one cyclic ether group capable of cationic polymerization in the molecule, a cationic polymerization initiator, peacock Dyes such as green, photochromic agents such as tribromophenylsulfone and crystal violet, anti-thermal color development agents, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoaming agents, flame retardants, 4-tert-butyl Additives such as stabilizers such as catechol-based, inhibitors, leveling agents, peeling accelerators, antioxidants, spices, imaging agents, and thermal crosslinking agents. These can be used individually by 1 type or in combination of 2 or more types. As long as these additives do not interfere with the object of this embodiment, about 0.0001 to 20 mass parts may be contained, respectively, based on 100 mass parts of the total amount of (A) component and (B) component. the

The photosensitive resin composition can be dissolved in solvents such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide and propylene glycol monomethyl ether or These mixed solvents are prepared in the form of a solution having a solid content of about 30 to 60% by mass. the

The photosensitive layer 20 in the photosensitive element 1 of this embodiment can be formed by apply|coating the said photosensitive resin composition on the support film 10, and removing a solvent. Here, as the coating method, known methods such as roll coating, comma coating, gravure coating, air knife coating, die coating, and bar coating can be used. In addition, the removal of the solvent can be performed, for example, by treating at a temperature of 70 to 150° C. for about 5 to 30 minutes. In addition, from the viewpoint of preventing diffusion of the organic solvent in the subsequent process, the amount of the remaining organic solvent in the photosensitive layer 20 is preferably 2% by mass or less. the

The thickness of the photosensitive layer 20 formed as described above is preferably 3 to 25 μm, more preferably 5 to 25 μm, still more preferably 7 to 20 μm, particularly preferably 10 to 15 μm in terms of thickness after drying. When the thickness is less than 3 μm, defects tend to easily occur when the photosensitive layer 20 is laminated on the circuit-forming substrate, or the tensile property tends to be insufficient. In addition, the resist film may be damaged during the development and etching steps, which may cause opening defects, and the production yield of printed wiring boards tends to decrease. On the other hand, when the thickness exceeds 25 μm, the resolution of the photosensitive layer 20 tends to be insufficient, and the liquid spreading of the etchant tends to be insufficient. In addition, the influence of side etching may become large, and it tends to be difficult to manufacture a high-density printed wiring board. the

In addition, the photosensitive element 1 may include a protective film (not shown) on the main surface of the photosensitive layer 20 opposite to the first main surface 12 in contact with the support film 10 . As the protective film, it is preferable to use a film whose adhesive force between the photosensitive layer 20 and the protective film is lower than that between the photosensitive layer 20 and the support film 10 , and to use a film with low shrinkage cavity. Specifically, inert polyolefin films, such as polyethylene and polypropylene, are mentioned, for example. From the standpoint of releasability from the photosensitive layer 20, a polyethylene film is preferable. The thickness of the protective film varies depending on the application, but is preferably about 1 to 100 μm. the

In addition to the supporting film 10, the photosensitive layer 20, and the protective film, the photosensitive element 1 may also include intermediate layers or protective layers such as a buffer layer, an adhesive layer, a light absorbing layer, and a gas barrier layer. the

The photosensitive element 1 of this embodiment can be stored, for example, in the original state, or in a state wound up on a cylindrical core after further laminating a protective film on the photosensitive layer 20 . At this time, it is preferable to wind up into a roll shape so that the support film 10 may become an outermost layer. In addition, from the standpoint of end face protection, it is preferable to provide an end face spacer on the end face of the photosensitive element 1 wound into a roll, and to provide a moisture-proof end face spacer from the standpoint of a fusing edge. In addition, as a packing method, it is preferable to pack in a black steel plate with low moisture permeability. the

Examples of the core material include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer). the

(Formation method of resist pattern)

The method for forming a resist pattern according to this embodiment is a method including the steps of: laminating the photosensitive element 1 on the circuit-forming substrate in the order of the photosensitive layer 20 and the support film 10 ; An exposure step of irradiating a predetermined portion of the photosensitive layer 20 with active light to form a photocured portion on the photosensitive layer 20 ; and a development step of removing portions of the photosensitive layer 20 other than the photocured portion. the

In the lamination step, as a method of laminating the photosensitive layer 20 on the circuit-forming substrate, when there is a protective film on the photosensitive layer 20, heating the photosensitive layer 20 to 70°C after removing the protective film is mentioned. ~130°C or so, press-bonding to a circuit-forming substrate with a pressure of about 0.1 to 1 MPa to perform lamination, etc. In this lamination step, lamination may be performed under reduced pressure. In addition, the laminated surface of the circuit-forming substrate is usually a metal surface, but it is not particularly limited. Moreover, in order to further improve lamination|stackability, you may perform the preheating process of the board|substrate for circuit formation. the

Next, for the photosensitive layer 20 laminated through the above lamination process, a photomask having a negative or positive mask pattern is aligned with the second main surface 14 of the support film 10 and bonded. Then, in the exposure step, the photosensitive layer 20 is irradiated with active light in an image form through the photomask and the support film 10 to form a photocured portion on the photosensitive layer 20 . As the light source of the active light rays, known light sources, such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, and xenon lamps, which efficiently emit ultraviolet light, visible light, etc., can be used. In addition, a photocured portion can also be formed on the photosensitive layer 20 by using a laser direct drawing exposure method. the

Next, after the above-mentioned exposure step, the photomask is peeled off from the support film 10 . Further, the support film 10 is peeled off from the photosensitive layer 20 and removed. Next, in the developing step, the unexposed portion (non-photocured portion) of the photosensitive layer 20 can be removed and developed by wet development, dry development, etc. using a developing solution such as an alkaline aqueous solution, an aqueous developing solution, or an organic solvent. Fabricate a resist pattern. the

As an alkaline aqueous solution, the dilute solution of 0.1-5 mass % of sodium carbonate, the dilute solution of 0.1-5 mass % of potassium carbonate, and the dilute solution of 0.1-5 mass % of sodium hydroxide are mentioned, for example. The pH of the alkaline aqueous solution is preferably set in the range of 9 to 11, and the temperature thereof is adjusted according to the developability of the photosensitive layer 20 . In addition, in the alkaline aqueous solution, a surfactant, an antifoaming agent, an organic solvent, and the like may be mixed. Moreover, as a system of image development, a immersion system, a spray system, a brush, and a tap are mentioned, for example. the

In addition, as a treatment after the development step, the resist pattern can be further cured by heating at about 60 to 250° C. or exposing at an exposure dose of about 0.2 to 10 J/cm ² as needed.

(Manufacturing method of printed circuit wiring board) 

The manufacturing method of the printed wiring board of this embodiment is performed by etching or plating the board|substrate for circuit formation on which the resist pattern was formed by the said resist pattern forming method. The photosensitive element of the present embodiment is particularly suitable for the manufacture of printed wiring boards by a method including a plating step, and is particularly suitable for use in the semi-additive process (SAP). The inventors of the present invention consider the following as the reason why it is suitable for use in SAP. The line width of the printed wiring board produced by SAP tends to be considerably thinner than that of the printed wiring board produced by the metal surface etching method. Also in the case of SAP, the resist film shape is transferred as it is into the plated line shape. Furthermore, in the case of a printed wiring board having an extremely fine line pattern produced by SAP, there is a tendency that the production yield is lowered due to the occurrence of microscopic resist film chipping. According to these requirements, the photosensitive element of this embodiment is especially suitable for use in SAP. the

As an etching solution used for etching, for example, a copper chloride solution, a ferric chloride solution, and an alkaline etching solution can be used.

As plating, copper plating, solder plating, nickel plating, and gold plating are mentioned, for example. the

After etching or plating, the resist pattern can be peeled off with, for example, an alkaline aqueous solution stronger than that used for development. As the strongly alkaline aqueous solution, for example, a 1-10 mass % sodium hydroxide aqueous solution and a 1-10 mass % potassium hydroxide aqueous solution can be used. Moreover, as a peeling method, a dipping method and a spraying method are mentioned, for example. In addition, the printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board, and may have small-diameter through holes. the

In addition, when plating a circuit-forming substrate having an insulating layer and a conductive layer formed on the insulating layer, it is necessary to remove the conductive layer other than the pattern. As the removal method, for example: a method of lightly etching after peeling off the resist pattern; followed by the above-mentioned plating, performing solder plating, etc., and then peeling off the resist pattern to mask the wiring part with solder, and then using a mask that can etch only the conductor layer. The method of processing the etching solution, etc. the

As mentioned above, the photosensitive element of this embodiment can be used for a printed wiring board. the

(Manufacturing method of semiconductor package substrate)

The photosensitive element 1 of the present embodiment can also be used for a package substrate including a rigid substrate and an insulating film formed on the rigid substrate. In this case, what is necessary is just to use the photocured part of the photosensitive layer 20 as an insulating film. When the photocured portion of the photosensitive layer 20 is used as, for example, a solder resist film for semiconductor packaging, after the development in the above-mentioned resist pattern forming method is completed, for the purpose of improving solder heat resistance, chemical resistance, etc., Ultraviolet irradiation or heating is preferably performed using a high-pressure mercury lamp. When irradiating ultraviolet rays, the irradiation amount can be adjusted as necessary, for example, it can also be irradiated at an irradiation amount of about 0.2 to 10 J/cm ² . Moreover, when heating a resist pattern, it is preferable to carry out in the range of about 100-170 degreeC for about 15 to 90 minutes. Furthermore, ultraviolet irradiation and heating may be performed at the same time, or the other may be performed after implementing either one. When performing ultraviolet irradiation and heating at the same time, it is more preferable to heat to 60-150 degreeC from the viewpoint of effectively imparting solder heat resistance, chemical resistance, etc.

The solder resist film formed from the photosensitive element of this embodiment can also be used as a protective film for wiring after soldering to the substrate, and has excellent physical properties such as tensile strength and elongation, and thermal shock resistance, so it can also be used as a solder resist film. Permanent masks for semiconductor packaging. the

The package substrate provided with the resist pattern as described above is then mounted on a semiconductor element or the like (for example, wire bonding, soldering connection), and then mounted on electronic equipment such as a computer. the

As mentioned above, although this invention was demonstrated in detail based on the embodiment, this invention is not limited to the said embodiment. Various deformation|transformation forms are possible for this invention in the range which does not deviate from the summary. the

[Example]

Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. the

(Examples 1-9 and Comparative Examples 1-10)

(A) Binder polymers having compositions shown in Table 1 or 2 below were synthesized. the

In addition, the weight average molecular weight of the binder polymer is measured by gel permeation chromatography (GPC), and calculated using a standard polystyrene calibration curve. The conditions of GPC and the acid value measurement procedure are shown below, and the measurement result is shown in Table 1 or 2. the

(GPC conditions) 

Pump: Hitachi L-6000 [manufactured by Hitachi, Ltd., trade name]

Columns: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (3 in total) [the above are manufactured by Hitachi Chemical Industry Co., Ltd., trade name]

Eluent: tetrahydrofuran

Measuring temperature: 40℃

Flow: 2.05mL/min

Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd., trade name]

(Acid value determination method)

Weigh about 1g of the synthesized adhesive polymer into the Erlenmeyer flask, add a mixed solvent (mass ratio: toluene/methanol=70/30) to dissolve, add an appropriate amount of phenolphthalein solution as an indicator, and use 0.1N potassium hydroxide The aqueous solution was titrated, and the acid value was measured by the following formula (α). the

x＝10×Vf×56.1/(Wp×I)(α)

In the formula (α), x represents the acid value (mgKOH/g), Vf represents the titration (mL) of the KOH aqueous solution of 0.1N, Wp represents the quality (g) of the resin solution measured, and I represents the amount of water in the resin solution measured. Ratio (% by mass) of non-volatile components. The measurement results are shown in Tables 1 and 2. the

[Table 1]

[Table 2]

Each component shown in following Table 3 was mixed, and the photosensitive resin composition was prepared. the

[table 3]

^* 1: EO-modified bisphenol A dimethacrylate (manufactured by Hitachi Chemical Industries, Ltd., brand name)

^* 2: EO, PO modified dimethacrylate (manufactured by Hitachi Chemical Industries, Ltd., brand name)

^* 3: EO modified urethane dimethacrylate (manufactured by Shin-Nakamura Industry Co., Ltd., brand name)

^* 4: EO-modified trimethylolpropane triacrylate (manufactured by Sartomer, trade name)

^* 5: N,N'-tetraethyl-4,4'-diaminobenzophenone

^* 6: 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer

^* 7: Crystal Violet

^* 8: Malachite green

^* 9: 4-tert-butylcatechol

(production of photosensitive element)

As a support film for the photosensitive element, PET films shown in Table 4 or 5 were prepared. Tables 4 and 5 show the results of measuring the total number of particles of 5 μm or more contained in each PET film and the haze. the

The total number of the above-mentioned particles and the like is a value obtained by measuring the number of particles and the like of 5 μm or more present in a unit of 1 mm ² with a polarizing microscope. The n number (measurement number) at this time was five. In addition, the haze of a support film is the value measured based on JISK7105. The thicknesses of these supporting films are all 16 μm.

Next, the solution of the said photosensitive resin composition was apply|coated so that thickness may become uniform on each PET film. Then, the solvent was removed by drying with a hot air convection dryer at 100° C. for 2 minutes, thereby forming a photosensitive layer. After drying, the photosensitive layer was covered with a protective film made of polyethylene (manufactured by Tamapoly Corporation, trade name "NF-15", thickness: 20 μm), to obtain a photosensitive element. In addition, the thicknesses of the photosensitive layers after drying were all 15 μm. the

(manufacturing of laminated body)

Copper-clad laminates (manufactured by Hitachi Chemical Industries, Ltd., trade name "MLC-E-679"), which is a glass epoxy material laminated with copper foil (thickness: 35 μm) on both sides, were bonded with MecEtchBond CZ-8100 (manufactured by MEC Corporation). ") copper surface roughened, after pickling and water washing, drying with air flow. The obtained copper-clad laminate was heated to 80° C., and the protective film was peeled off, and the photosensitive element was laminated so that the photosensitive layer came into contact with the copper surface. In this way, a laminate in which the copper-clad laminate, the photosensitive layer, and the support film were laminated in this order was obtained. Lamination was performed using a 120° C. hot roll, a pressure bonding pressure of 0.4 MPa, and a roll speed of 1.5 m/min. These laminated bodies were used as test pieces in the tests shown below. the

(Determination of minimum developing time)

Spray development was carried out on the photosensitive layer laminated on the substrate of 125 mm x 200 mm square, and the time until the unexposed portion was completely removed was measured as the minimum development time. The measurement results are shown in Tables 4 and 5. the

(Measurement test of light sensitivity)

A negative Stouffer 21 step exposure table (Stouffer 21 step tablet) was placed on the support film of the test piece, and an exposure machine (manufactured by Oak Seisakusho Co., Ltd., trade name "EXM-1201") with a high-pressure mercury lamp was used. The photosensitive layer was exposed to an irradiation energy of 100 mJ/cm ² . Next, the support film was peeled off, and spray development was performed with a 1% by mass sodium carbonate aqueous solution at 30° C. for twice the minimum development time to remove unexposed portions for development. Then, the photosensitivity of the photosensitive resin composition was evaluated by measuring the number of stages of the step exposure meter of the photocured film formed on the copper-clad laminate. The results are shown in Tables 4 and 5. The light sensitivity is represented by the number of segments of the step exposure meter, and the higher the number of steps of the step exposure meter, the higher the light sensitivity.

(Measurement test of resolution)

In order to study the resolution, a photomask (photo tool) with a Stouffer 21-step exposure meter and a wiring pattern with a line width/space of 2/2 to 30/30 (unit: μm) were used for resolution evaluation A negative-type glass-chrome-type photomask was bonded to the support film of the test piece, using an exposure machine (manufactured by Oak Seisakusho Co., Ltd., trade name "EXM-1201") with a high-pressure mercury lamp, and exposed in a Stouffer21 stage. Exposure was carried out at an irradiation energy of 5.0 for the number of stages remaining after the development of the table. Next, the support film was peeled off, and spray development was carried out at 30° C. with a 1% by mass sodium carbonate aqueous solution for four times the minimum development time to remove unexposed portions for development. Here, the resolution was evaluated by the minimum value (unit: μm) at which the space between the line widths of the unexposed portion can be completely removed by the developing process. In addition, in the evaluation of the resolution, the smaller the numerical value, the better the value. The results are shown in Tables 4 and 5. the

(Evaluation of the side shape of the resist line)

In the substrate evaluated by the above-mentioned resolution measurement test, the side profile of the resist line was observed with a scanning electron microscope (manufactured by Hitachi High Technologies, trade name SU-1500), and evaluated as follows. The results are shown in Tables 4 and 5. the

A: smooth shape

B: slightly rough shape

C: rough shape

(Measurement test of adhesion) 

In order to study the adhesion, a photomask with a Stouffer 21-step exposure meter and a wiring pattern with a line width/space of 2/1000 to 30/1000 (unit: μm) were used as negative glass for adhesion evaluation A chromium-type photomask was bonded to the support film of the test piece, and an exposure machine (manufactured by Oak Seisakusho Co., Ltd., trade name "EXM-1201") with a high-pressure mercury lamp was used to develop a Stouffer 21-stage exposure meter. After the residual stage segment number reaches 8.0 irradiation energy is exposed. Next, the support film was peeled off, and spray development was carried out at 30° C. with a 1% by mass sodium carbonate aqueous solution for four times the minimum development time to remove unexposed portions for development. Here, the adhesiveness was evaluated by the value (unit: μm) at which the line width of the unexposed portion can be completely removed by the developing treatment. In addition, in the evaluation of adhesiveness, the smaller the numerical value, the better the value. The results are shown in Tables 4 and 5. the

(Measurement test of the occurrence number of resist film defects)

In order to study the number of occurrences of resist film defects, a photomask with a Stouffer 21-step exposure meter and a glass-chrome-type photomask with a wiring pattern of 10/30 line width/space (unit: μm) were bonded together. On the support film of the test piece, exposure was performed using an exposure machine equipped with a high-pressure mercury lamp, with irradiation energy such that the number of remaining steps after development of a Stouffer 21 step exposure meter reached 5.0. Next, the support film was peeled off, and a 1 mass % sodium carbonate aqueous solution at 30° C. was sprayed for twice the minimum developing time to remove the unexposed portion. Next, using a microscope, the number of resist film defects was counted. The line length was 1 mm and the number of lines was 10 as the observation unit, and the average value when n was 5 was taken as the number of occurrences of resist film defects. The results are shown in Tables 4 and 5. the

[Table 4]

^* 1: Biaxially oriented PET film with a three-layer structure having layers containing fine particles on the front and back, manufactured by Toray Co., Ltd.

[table 5]

^* 1: Biaxially oriented PET film with a three-layer structure having layers containing fine particles on the front and back, manufactured by Toray Co., Ltd.

^* 2: Biaxially oriented PET film with a double-layer structure in which the content of fine particles is different on the front and back, manufactured by Teijin DuPont Co., Ltd.

^* 3: Biaxially oriented PET film with a three-layer structure having layers containing fine particles on the front and back, manufactured by Teijin DuPont Co., Ltd.

As shown in Tables 4 and 5, the hazes of the PET films used in Examples 1 to 9 and Comparative Example 9 are approximately the same, but the PET films used in Examples 1 to 9 have particles of 5 μm or more in 1 ^mm2 unit The total number of particles and the like is 1, which is very small compared with the PET film (the total number of particles and the like is 28) used in Comparative Example 9. Therefore, the number of occurrences of resist film defects was also as follows: In Examples 1 to 9, the number of occurrences of resist film defects was 0, which was very small compared with Comparative Example 9. In addition, when the support film of Comparative Example 10 with a total of 318 particles and the like was used, the number of occurrences of resist film defects increased to 213. Furthermore, it was confirmed that in Examples 1 to 9, the shape of the side surface of the resist film after development was smooth, and a favorable resist pattern was formed.

In addition, as shown in Table 4, since the acid value and weight-average molecular weight of the (A) component used in Examples 1 to 9 are within an appropriate range, the minimum developing time is very short, and it can be confirmed that the printed wiring board does not deteriorate. productivity. Regarding the scope of the suitable weight-average molecular weight obtained by the above formula (I), when the acid value is 130 mgKOH/g, it is 1 to 53,900, when the acid value is 110 mgKOH/g, it is 1 to 36,000, and the acid value is 90 mgKOH/g. When the acid value is 80 mgKOH/g, it is 10,000 to 24,000 to 20,000. the

Description of symbols

1...photosensitive element, 10...support film, 12...first main surface, 14...second main surface, 20...photosensitive layer (photosensitive resin composition layer). the

Claims (9)

1. photosensitive element, it is to possess support film and the photosensitive element that is formed at the photosensitive polymer combination layer on the said support film, wherein,

The mist degree of said support film is 0.01～2.0%, and contained diameter is that above particle of 5 μ m and diameter are the 5/mm that adds up to of the above condensation product of 5 μ m in the said support film ²Below,

Said photosensitive polymer combination layer contains binder polymer, has the optical polymerism compound and the Photoepolymerizationinitiater initiater of ethylenic unsaturated link,

The acid number x of said binder polymer is 60～130mgKOH/g, and weight-average molecular weight Mw satisfies the relation shown in the following formula (I),

10000≤Mw＜4000e ^0.02x (I)

In the formula (I), x representes the acid number of binder polymer, and Mw representes the weight-average molecular weight of binder polymer.

2. photosensitive element according to claim 1, wherein, said optical polymerism compound comprises the compound shown in the formula (II),

In the general formula (II), R ¹And R ²Represent hydrogen atom or methyl independently of one another, Y representes that carbon number is 2～6 alkylidene, n ¹And n ²Represent positive integer respectively, n ¹+ n ²Be 4～40, the Y of a plurality of existence can be same to each other or different to each other.

3. photosensitive element according to claim 1 and 2, wherein, said binder polymer have formula (III), (IV) or (V) shown in the divalent group,

During general formula (III), (IV) reach (V), R ³, R ⁴And R ⁶Represent hydrogen atom or methyl independently of one another, R ⁵The expression carbon number is that 1～4 alkyl, carbon number are 1～3 alkoxy, hydroxyl or halogen atom, R ⁷The expression carbon number is 1～10 alkyl, and p representes 0～5 integer, and p is 2 when above, the R of a plurality of existence ⁵Can be same to each other or different to each other.

4. photosensitive element according to claim 3, wherein, said binder polymer also has the divalent group shown in the formula (VI),

In the general formula (VI), R ¹⁵Expression hydrogen atom or methyl, R ¹⁶The expression carbon number is that 1～4 alkyl, carbon number are 1～3 alkoxy, hydroxyl or halogen atom, and q representes 0～5 integer, and q is 2 when above, the R of a plurality of existence ¹⁶Can be same to each other or different to each other.

5. according to each described photosensitive element in the claim 1～4, wherein, said Photoepolymerizationinitiater initiater contains 2,4,5-triarylimidazoles dipolymer.

6. the formation method of a corrosion-resisting pattern, it comprises following operation: the sequential cascade of each described photosensitive element in the claim 1～5 according to said photosensitive polymer combination layer, said support film formed with the range upon range of operation on the substrate to circuit;

Across the established part irradiation active ray of said support film, in said photosensitive polymer combination layer, to form the exposure process of photocuring portion to said photosensitive polymer combination layer; And

The developing procedure that said photosensitive polymer combination layer beyond the said photocuring portion is removed.

7. the manufacturing approach of a printed circuit board, it has the circuit that the formation method through the described corrosion-resisting pattern of claim 6 is formed with corrosion-resisting pattern and forms the operation of implementing etching or plating with substrate.

8. printed circuit board, it is made through the described manufacturing approach of claim 7.

9. the purposes of each described photosensitive element in printed circuit board in the claim 1～5.

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