TWI591434B - Photosensitive device, method of forming photoresist pattern using the same, manufacturing method of printed circuit board, and printed circuit board - Google Patents

Description

Photosensitive element, method for forming photoresist pattern using the same, method for manufacturing printed circuit board, and printed circuit board

The present invention relates to a photosensitive element, a method of forming a photoresist pattern using the same, a method of manufacturing a printed circuit board, and a printed circuit board.

Conventionally, in the field of manufacturing of printed circuit boards and the field of precision metal processing, photoresist materials for etching and plating have been widely used as a photosensitive resin composition layer (hereinafter referred to as "photosensitive layer") and a support film. And a photosensitive element which consists of a protective film (Japanese Unexamined-Patent No. 01-221735, Unexamined-Japanese-Patent No. 02-230149, Unexamined-Japanese-Patent No. 56-040. Japanese Laid-Open Patent Publication No. 59-097138, JP-A-59-216141, and JP-A-63-197942.

The printed circuit board is manufactured 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 applied to the photosensitive layer, the unexposed portion of the photosensitive layer is removed by the developing liquid to form a photoresist pattern. Then, according to the photoresist pattern, the conductive film is patterned to form a printed circuit board.

In recent years, with the increase in density of printed circuit boards, the contact area between the circuit-forming substrate and the photosensitive layer of the photoresist material has become small. Therefore, the photosensitive resin composition forming the photosensitive layer is required to have excellent mechanical strength, chemical resistance, and flexibility in the etching or plating step. At the same time, excellent adhesion to the circuit-forming substrate and excellent resolution at the time of pattern formation are required. example A photosensitive resin composition containing a binder polymer having a specific structure for the purpose of exhibiting excellent plating resistance is disclosed (see JP-A-2006-234995, JP-A-2008-039978).

When a photosensitive element is usually used to form a photoresist, the photosensitive layer is laminated on a substrate, and then the photosensitive layer is exposed through a support film. Therefore, in order to obtain a high resolution in the formation of a pattern, not only a photosensitive resin composition but also the properties of the supporting film to be used are considered.

In order to obtain a high resolution, for example, it is proposed to contain inorganic or organic fine particles having an average particle diameter of about 0.01 to 5 μm on the outermost surface of one of the supporting films to reduce the haze of the supporting film, even if the photosensitive layer is exposed by the supporting film. For the method of the resolution, for example, refer to Japanese Patent No. 4014872, International Publication No. 08/093643, Japanese Patent Publication No. Hei 07-333853, and International Publication No. 00/079344.

However, in the conventional method, it is possible to suppress the decrease in the resolution of the photosensitive layer due to the influence of the supporting film and to suppress the shape defect (photoresist defect) after hardening to some extent, but further improvement is required in order to satisfy the characteristics required for the photosensitive element in recent years. .

When the conventional photosensitive resin composition is combined with the support film described in the patent publication No. 4014872, the international publication No. 08/093643, the Japanese Patent Publication No. Hei 07-333853, and the International Publication No. 00/079344, the recent requirements are met. There are limits to the development and resolution, and there is still room for further improvement.

In view of the above, it is an object of the present invention to provide a photosensitive element which is capable of sufficiently reducing a photoresist defect and having excellent developability and resolution at the time of pattern formation.

The present invention provides a photosensitive element comprising a photosensitive member having 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 is provided The total number of particles having a diameter of 5 μm or more and agglomerates having a diameter of 5 μm or more is 5 pieces/mm ² or less. The photosensitive resin composition layer contains a binder polymer, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiator. The acid value x of the above-mentioned binder polymer is 60 to 130 mgKOH/g, and the weight average molecular weight Mw satisfies the relationship represented by the following formula (I).

10000≦Mw< ^{4000e 0.02x} (I)

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

In the photosensitive element of the present invention, since the support film having the above configuration is provided, the photoresist defect can be sufficiently reduced. In addition, since the photosensitive element of the present invention is provided with the photosensitive resin composition layer having the above-described configuration, it is possible to sufficiently reduce the photoresist defect and to have excellent developability and resolution at the time of pattern formation.

The photopolymerizable compound having an ethylenically unsaturated bond may contain a compound represented by the following general formula (II).

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 having 2 to 6 carbon atoms, and n ¹ and n ² each independently represent a positive integer, n ¹ + The n ² series is 4 to 40, and the plural Ys may be the same or different from each other.

Since the compound represented by the above general formula (II) is contained, the balance of adhesion, resolution, and chemical resistance is improved, and a photoresist pattern of an extremely fine line can be formed.

Further, since the photosensitive element of the present invention has a divalent group represented by the following general formulas (III), (IV) and (V) because of the binder polymer, the balance of adhesion, resolution and peelability is obtained. Better, can form a very thin line of photoresist pattern.

In the general formulae (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 having 1 to 4 carbon atoms and a carbon number of 1 to 4; 3 is an alkoxy group, a hydroxyl group or a halogen atom, R ⁷ represents an alkyl group having 1 to 10 carbon atoms, p is an integer of 0 to 5, and when p is 2 or more, R ^{5 which is} present in plural plural may be the same or different.

In the photosensitive element of the present invention, since the binder polymer further has a divalent group represented by the following general formula (VI), the balance of adhesion, resolution and releasability is further improved.

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

Further, in the photosensitive element of the present invention, the photopolymerization initiator may contain a 2,4,5-triarylimidazole dimer. Thereby, the light sensitivity can be maintained, so that the adhesion and the resolution are more excellent, and a photoresist pattern of an extremely thin line can be formed.

Moreover, the present invention provides a method for forming a photoresist pattern, comprising: the photosensitive element according to the photosensitive resin composition layer; a laminating step of sequentially supporting the film on the circuit-forming substrate; passing the active light through the support film, irradiating a predetermined portion of the photosensitive resin composition layer, and forming a photo-cured portion on the photosensitive resin composition layer Exposure step; a developing step of removing the photosensitive resin composition layer other than the photocured portion. According to the method for forming a photoresist pattern of the present invention, since the photosensitive element of the present invention described above is used, a photoresist pattern of an extremely fine line can be obtained efficiently.

The present invention provides a method of manufacturing a printed circuit board, which is a method of manufacturing a printed circuit board having a step of performing etching or plating on a circuit for forming a circuit pattern having a photoresist pattern, and a method of manufacturing the same by the above-described manufacturing method Printed circuit board. According to the method for producing a printed wiring board of the present invention, since the method for forming a photoresist pattern using the photosensitive element of the present invention is employed, a high-density printed circuit board having a wiring pattern of an extremely thin line can be obtained.

According to the photosensitive element of the present invention, the photoresist defect can be sufficiently reduced, and a photosensitive element having excellent developability and resolution at the time of pattern formation can be provided.

Description of the preferred embodiment

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawing, the positional relationship of up, down, left, and right, etc., is based on the positional relationship shown in the drawing. Further, the dimensional ratio of the drawings is not limited to the illustrated ratio. Also, "(meth) acrylate in this specification "Acrylate" and its corresponding "methacrylate", in the same way, "(meth)acrylyl" means "acrylic" and its corresponding "methacryl", "(methyl) "Propylene thiol" means "acryloyl fluorenyl" and its corresponding "methacryl fluorenyl".

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a preferred embodiment of a photosensitive element of the present invention. The 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. Further, the support film 10 has the second main surface 14 on the side opposite to the first main surface 12.

(support film)

The support film 10 has a haze of 0.01 to 2.0%, and the total number of particles having a diameter of 5 μm or more and agglomerates having a diameter of 5 μm or more (hereinafter simply referred to as "particles or the like") contained in the film 10 is 5 pieces/mm ² or less. By. Here, the particles having a diameter of 5 μm or more contained in the support film 10 include both the first main surface 12 and the second main surface 14 of the support film 10 and those existing inside the film 10. Further, particles having a diameter of 5 μm or more include primary particles having a diameter of 5 μm or more and aggregates of primary particles having a diameter of 5 μm or less.

The total number of particles having a diameter of 5 μm or more is preferably 5 pieces/mm ² or less, more preferably 3 pieces/mm ² or less, from the viewpoint of reducing partial defects of light resistance after exposure and development, and more preferably 1 / mm ² or less. When a photosensitive element having a total number of such particles or more of more than 5/mm ² is used in the production of a printed circuit board, it causes an open defect during etching or a short-circuit defect during plating, and the printed circuit board is manufactured well. The tendency to decrease the rate.

Even if the support film 10 contains a plurality of particles having a diameter of less than 5 μm, etc., The effect of light scattering is small. The reason for this is that in the exposure step described later, when the light is applied to the photosensitive layer 20, the photo-curing reaction of the photosensitive layer 20 is not only in the light-irradiating portion but also in the lateral direction (relative to the direct irradiation of the light). The reaction is performed in the direction in which the light is irradiated in the vertical direction. Therefore, when the particle diameter is small, the photohardening reaction in the lower portion of the particle proceeds sufficiently. However, as the particle diameter increases, the photohardening reaction in the lower portion of the particle does not sufficiently proceed, and thus a photoresist defect (resistance defect) may occur.

Particles having a diameter of 5 μm or more contained in the support film 10 constitute a component of the support film 10, and examples thereof include a gel of a polymer, a monomer of a raw material, a catalyst used in the production, and an inorganic or organic resin if necessary. When the fine particles are formed in a film, agglomerates formed by agglutination, swelling caused by a slip agent and an adhesive generated when a lubricant layer is applied to the film, and particles having a diameter of 5 μm or more contained in the film are generated. . When it is desired to set the particles having a diameter of 5 μm or more to 5 pieces/mm ² or less, those having a smaller particle diameter or excellent dispersibility can be selected among these particles and the like.

The total number of particles having a diameter of 5 μm or more can be measured using a polarizing microscope. Further, agglomerates formed by primary particles having a diameter of 5 μm or more and a primary particle having a diameter of 5 μm were aggregated as one calculation. Fig. 2 is a photograph of a polarizing microscope for observing the surface of a supporting film having particles having a diameter of 5 μm or more. In Fig. 2, a portion surrounded by a circle is an example of a portion corresponding to particles having a diameter of 5 μm or more. Fig. 3 is a scanning-type micrograph of a resist pattern formed by a photosensitive element having a photosensitive layer on a support film having a plurality of particles having a diameter of 5 μm or more. The portion surrounded by the frame represents the photoresist defect. Thus, most of the surface of the support film has a diameter of 5 μm or more. When the particles are in the like, a photoresist defect occurs.

The material of the support film 10 is not particularly limited as long as the total number of particles having a diameter of 5 μm or more is 5 pieces/mm ² or less. The support film 10 is, for example, a film containing one or more kinds of resin materials selected from the group consisting of polyesters such as polyethylene terephthalate (hereinafter referred to as "PET") and polyolefins such as polypropylene and polyethylene. .

The support film 10 may be a single layer or a plurality of layers. For example, when a two-layer support film composed of two layers is used, a two-layer film formed by laminating a resin layer containing fine particles on one surface of a biaxially oriented polyester film is used as a support film, and a resin layer containing the above-mentioned fine particles is formed. It is preferable that the photosensitive layer 20 is formed on the surface on the opposite side. The support film 10 can also use a multilayer support film composed of three layers (for example, layer A/layer B/layer A). The configuration of the multilayer support film is not particularly limited. However, from the viewpoint of the smoothness of the film and the like, the outermost layer (the A layer formed by the above three layers) is preferably a resin layer containing fine particles.

In the conventional two-layer support film, a resin layer having fine particles is applied to a biaxially oriented polyester film, and thus, when the photosensitive layer is laminated, the resin layer containing fine particles is easily peeled off, and the resin layer after peeling adheres to the photosensitive layer. Layers may cause undesirable causes. Therefore, in the present embodiment, it is preferable to use a multilayer support film composed of three layers of a resin layer containing fine particles and a biaxially oriented polyester film.

In the present embodiment, the total number of particles having a diameter of 5 μm or more contained in the support film 10 is adjusted to be 5 pieces/mm ² or less, and a multilayer support film containing the resin layer of such fine particles is provided. Therefore, the smoothness of the film is improved, and at the same time, the balance of light scattering at the time of exposure is suppressed, and a higher level can be achieved. The average particle diameter of the fine particles is preferably 0.1 to 10 times, more preferably 0.2 to 5 times, the layer thickness of the resin layer containing the fine particles. When the average particle diameter is less than 0.1 times, the slip property tends to be deteriorated. When the average particle diameter is less than 10 times, the photosensitive layer tends to have irregularities.

The fine particles are preferably contained in the resin layer containing fine particles in an amount of 0.01 to 50% by mass based on the mass of the resin. For the fine particles, for example, fine particles such as fine particles, aggregates, cerium oxide fine particles (aggregated cerium oxide, etc.), calcium carbonate fine particles, alumina fine particles, titanium oxide fine particles, and barium sulfate fine particles formed by polymerization with various nucleating agents can be used. And organic fine particles such as crosslinked polystyrene fine particles, acrylic fine particles, and yttrium imide fine particles, and the like.

In the multilayer support film of three or more layers, the intermediate layer containing one or more of the outermost layers containing the fine particles may be one containing or not containing the fine particles, and it is preferable that the fine particles are not contained from the viewpoint of resolution. . When the intermediate layer contains the above fine particles, the content of the intermediate layer is preferably 1/3 or less, more preferably 1/5 or less, of the content of the outermost layer.

The layer thickness of the resin layer containing the fine particles is preferably from 0.01 to 5 μm, more preferably from 0.05 to 3 μm, particularly preferably from 0.1 to 2 μm, from the viewpoint of resolution. The surface that is not opposed to the intermediate layer of the outermost layer preferably has a static friction coefficient of 1.2 or less. When the static friction coefficient exceeds 1.2, wrinkles are likely to occur during the production of the film and at the time of production of the photosensitive element, and static electricity tends to be generated, and there is a tendency that the garbage tends to adhere. In the present embodiment, the static friction coefficient can be measured in accordance with ASTM D1894.

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

Further, the support film 10 may contain an antistatic agent or the like as necessary, within a range that does not affect the photosensitivity of the photosensitive layer 20.

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, and particularly preferably 0.5% or less from the viewpoint of excellent light sensitivity and resolution. Here, "haze" means turbidity. The haze of the support film 10 in the present embodiment is a value measured by commercially available turbidity measurement according to the method specified in JIS K 7105. The haze can be measured using, for example, a commercially available turbidity meter such as NDH-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd., trade name). The lower limit of the haze is preferably close to zero from the viewpoint of excellent light sensitivity and resolution, and the haze is preferably 0.01 or more from the viewpoint of the winding property at the time of production of the support film 10 and the like. When the haze is less than 0.01, the support film does not contain fine particles or the like, and there is a problem in winding during the production of the support film, and wrinkles or the like tend to occur.

The thickness of the support film 10 is preferably 5 to 40 μm, more preferably 8 to 35 μm, still more preferably 10 to 30 μm, and particularly preferably 12 to 25 μm. When the thickness is less than 5 μm, when the support film is peeled off from the photosensitive member, the support film tends to be easily broken. Moreover, when the thickness exceeds 40 μm, the resolution tends to decrease, and at the same time, the inexpensiveness tends to be inferior.

Further, the support film 10 can be obtained from a commercially available general industrial film, and can be used as a support film 10 of the photosensitive element 1, or can be appropriately processed. use. A commercially available general-purpose film which can be used as the support film 10, for example, a PET film "QS-48" (manufactured by Toray Industries, Inc.) having a three-layer structure in which the outermost layer contains fine particles.

(photosensitive layer)

The photosensitive layer 20 is a layer composed 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) light. A polymerization initiator (hereinafter referred to as "(C) component"). Each component will be described in detail below.

(adhesive polymer)

The binder polymer of the component (A) is not particularly limited as long as it has an acid value x of 60 to 130 mgKOH/g and the weight average molecular weight Mw satisfies the relationship represented by the following formula (I).

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, and provides various properties after curing (developability, adhesion, resolution, shape of the photoresist side, and photoresist defect). An excellent photosensitive resin composition.

The acid value x of the binder polymer is 60 to 130 mgKOH/g, but preferably 65 to 130 mgKOH/g, more preferably 90 to 130 mgKOH/g, still more preferably 110 to 130 mgKOH/g, from the viewpoint of satisfactorily satisfying the above characteristics. g.

And the acid value (the number of mg of potassium hydroxide (KOH) required to neutralize 1 g of the sample The same index, for example, has an acid equivalent (g number of a polymer having 1 equivalent of a carboxylic acid), and these can be mutually converted.

The weight average molecular weight of the binder polymer satisfies the relationship expressed by the above formula (I). The lower limit of the Mw of the binder polymer is 10,000 or more, and from the viewpoint of excellent toughness of the photosensitive layer, it is preferably 15,000 or more, more preferably 20,000 or more, and still more preferably 25,000 or more. Further, the upper limit of the Mw of the binder polymer is ^{4000e 0.02x} or less, and from the viewpoint of satisfactorily satisfying the characteristics after curing, it is preferably 90% or less, more preferably 80% or less, more preferably 80% or less, more preferably ^4,000 . It is 70% or less. The weight average molecular weight is measured by gel permeation chromatography (hereinafter referred to as "GPC") and converted to a value of standard polystyrene, and the measurement conditions are the same as those described in the examples below.

The binder polymer is, for example, an acrylic resin, a styrene resin, an epoxy resin, a guanamine resin, a guanamine epoxy resin, an alkyd resin, and a phenol resin. Among these, an acrylic resin is preferred from the viewpoint of alkali developability. These may be used alone or in combination of two or more.

The binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer. The polymerizable monomer is, for example, a polymerizable styrene derivative such as styrene, vinyl toluene, p-methylstyrene, p-chlorostyrene, α-methylstyrene or α-methylstyrene derivative, Ethyl alcohol esters such as acrylamide, acrylonitrile and vinyl-n-butyl ester, alkyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, Methyl) dimethylaminoethyl acrylate, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate And 2,2,3,3-tetrafluoropropyl (meth) acrylate, etc. Acrylate, (meth)acrylic acid, α-bromo (meth)acrylic acid, α-chloro(meth)acrylic acid, β-furyl (meth)acrylic acid, and β-styryl (meth)acrylic acid a maleic acid derivative such as a (meth)acrylic acid derivative, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate or monoisopropyl maleate, fumaric acid, Cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. These may be used alone or in combination of two or more.

The binder polymer preferably contains a structural unit represented by the following general formulas (III), (IV) and (V) from the viewpoint of the balance between the resistance to the developing solution (developing liquid resistance) and the peeling property. Moreover, since the development liquid resistance is improved, there is a tendency that the adhesion and the resolution are improved.

In the general formulae (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 having 1 to 4 carbon atoms and a carbon number of 1 to 4; 3 is an alkoxy group, a hydroxyl group or a halogen atom, R ⁷ is an alkyl group having 1 to 6 carbon atoms, p is an integer of 0 to 5, and when p is 2 or more, R ⁵ which is plural may be the same or different.

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

(A) When the binder polymer contains the structural unit represented by the above general formula (III), the content ratio is based on the total solid content of the (A) binder polymer of the copolymer, and the development and releasability are based on The excellent viewpoint is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more. Moreover, from the viewpoint of excellent adhesion and resolution, 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 structural unit represented by the above general formula (IV) is based on styrene (R ⁴ = hydrogen atom, p = 0), styrene derivative, α-methylstyrene (R ⁴ = methyl group, p = 0) and α. - The structural unit of the methylstyrene derivative. In the present embodiment, the "styrene derivative" and the "α-methylstyrene derivative" mean that the hydrogen atom of the benzene ring of styrene and α-methylstyrene is substituted with a substituent R ⁵ (carbon number 1 to 4). The alkyl group, the alkoxy group having 1 to 3 carbon atoms, the hydroxyl group, and the halogen atom are substituted. The above styrene derivatives are, for example, methyl styrene, ethyl styrene, t-butyl styrene, methoxy styrene, ethoxy styrene, hydroxystyrene and chlorostyrene, preferably p-position. There are structural units with R ⁵ substitution. The α-methylstyrene derivative is, for example, one in which the hydrogen atom at the α-position of the vinyl group is substituted with a methyl group in the above styrene derivative.

(A) When the binder polymer contains the structural unit represented by the above general formula (IV), the content ratio thereof is based on the total solid content of the (A) binder polymer of the copolymer, and the adhesion and resolution are based on The excellent viewpoint is preferably 3% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and particularly preferably 20% by mass or more. Further, from the viewpoint of the flexibility of the peeling property and the photoresist after curing, it is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, and still more preferably 45% by mass or less.

The structural unit represented by the above general formula (V) is based on the structural unit of the alkyl (meth)acrylate. The alkyl (meth)acrylate is, for example, in the general formula (V), and R ⁷ is an alkyl group having 1 to 12 carbon atoms. 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. The alkyl (meth)acrylate may, for example, be methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate or butyl (meth)acrylate. Tert-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethyl (meth)acrylate Hexyl hexyl ester and structural isomers thereof. From the viewpoint of improving the resolution and shortening the peeling time, R ^{7 is} preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms which has no substituent, and more preferably a methyl group.

(A) When the binder polymer contains the structural unit represented by the above general formula (V), the content ratio thereof is based on the total solid content of the (A) binder polymer of the copolymer, and is superior from the viewpoint of excellent releasability. It is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, and particularly preferably 15% by mass or more. Also from the viewpoint of excellent resolution, it is preferably 55 The amount is preferably 5% by weight or less, more preferably 50% by mass or less, still more preferably 45% by mass or less, and still more preferably 40% by mass or less.

Further, the (A) binder polymer is preferably a structural unit represented by the following general formula (VI) from the viewpoint of balance between adhesion, resolution and releasability.

In the general formula (VI), R ¹⁵ represents a hydrogen atom or a methyl group, and R ¹⁶ represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group or a halogen atom. The q system represents an integer of 0 to 5, and when q is 2 or more, the R ^{16 in} which the plural exists may be the same or different from each other.

The structural unit represented by the above general formula (VI) is a structural unit based on a benzyl (meth) acrylate and a benzyl (meth) acrylate derivative. The above benzyl (meth) acrylate derivatives are, for example, 4-methylbenzyl (meth) acrylate, 4-ethylbenzyl (meth) acrylate, 4-tert-butyl benzyl (methyl) Acrylate, 4-methoxybenzyl (meth) acrylate, 4-ethoxybenzyl (meth) acrylate, 4-hydroxybenzyl (meth) acrylate, 4-chlorobenzyl ( Methyl) acrylate. The above general formula ( VI) indicates a structural unit from the viewpoints of developing property, etching resistance, plating resistance, and flexibility of maintaining a cured film, and among them, a structural unit based on benzyl (meth) acrylate (q = 0) is preferred. .

(A) The binder polymer contains the content ratio of the structural unit represented by the above general formula (VI) based on the total solid content of the (A) binder polymer of the copolymer, and is preferably from the viewpoint of excellent adhesion. It is 5% by mass or more, more preferably 10% by mass or more, and still more preferably 20% by mass or more. Further, from the viewpoint of the flexibility of the peeling property and the photoresist after curing, it is preferably 60% by mass or less, more preferably 55% by mass or less, still more preferably 50% by mass or less, and still more preferably 45% by mass or less.

These binder polymers may be used alone or in combination of two or more. When a combination of two or more kinds of binder polymers is used, for example, two or more kinds of binder polymers composed of different copolymerization components (including different repeating units as constituent components) and two different weight average molecular weights are used. The above binder polymer, two or more kinds of binder polymers having different degrees of dispersion, and the like. Further, a polymer having a plurality of morphological molecular weight distributions described in JP-A-11-327137 may be used as the binder polymer.

Further, when the development step described later is carried out in an organic solvent, it is preferred to prepare a polymerizable monomer having a carboxyl group in a small amount. The binder polymer may have a photosensitive functional group as necessary.

The amount of the binder polymer of the component (A) is preferably from 40 to 70 parts by mass, more preferably from 45 to 65 parts by mass based on 100 parts by mass of the total of the component (A) and the component (B) described later. More preferably, it is 50 to 60 parts by mass. . When the amount is less than 40 parts by mass, the photosensitive layer after exposure curing tends to become brittle, and when it exceeds 70 parts by mass, the resolution and the light sensitivity tend to be insufficient.

(Photopolymerizable compound having an ethylenically unsaturated bond)

The photopolymerizable compound having an ethylenically unsaturated bond of the component (B) contains a compound represented by the following general formula (II).

In the above general formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and preferably a methyl group. The Y system represents an alkylene group having 2 to 6 carbon atoms. n ¹ and n ² each independently 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, more preferably an integer of 8 to 28. It is preferably an integer from 8 to 20, preferably an integer from 8 to 16, and most preferably an integer from 8 to 12. When the value of n ¹ + n ² is less than 4, the compatibility with the binder polymer is lowered, and when the photosensitive element is laminated on the substrate for circuit formation, the film tends to be easily peeled off, and when the value of n ¹ + n ² exceeds 40, The hydrophilicity of the photosensitive layer is increased, and when the image is developed, the photoresist is easily peeled off, and the plating resistance tends to be lowered. The Ys present in the complex number in the molecule may be the same or different.

The above alkylene group having 2 to 6 carbon atoms is, for example, an extended ethyl group, a propyl group, an extended isopropyl group, a butyl group, a pentyl group and a hexyl group. Among these, from the viewpoint of improving resolution and electroplating resistance, it is preferred to extend ethyl and isopropyl, and more preferably Ethyl.

The aromatic ring in the above general formula (II) may have a substituent. Examples of the substituent 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, a benzamidine methyl group, an amine group, and a carbon number of 1 to 10. Alkylamino group, dialkylamino group having 2 to 20 carbon atoms, nitro group, cyano group, carbonyl group, thiol group, alkyl thio group having 1 to 10 carbon atoms, allyl group, hydroxyl group, carbon number a hydroxyalkyl group having 1 to 20 hydroxyalkyl groups, a carboxyl group or an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and a carbon number of 1 Alkoxycarbonyl group of ~20, alkylcarbonyl group having 2 to 10 carbon atoms, alkenyl group having 2 to 10 carbon atoms, N-alkylaminocarbamyl group having 2 to 10 carbon atoms, and a group having a heterocyclic ring, and An aryl group substituted with such substituents. The above substituent may also form a condensed ring, or the hydrogen atom in the substituent may be substituted with the above substituent or the like of a halogen atom or the like. Further, when the number of substituents is 2 or more, respectively. The substituents of 2 or more may be the same or different.

The compound represented by the above general formula (II) is, for example, 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((methyl) Propyleneoxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane and 2,2-bis(4-((A) A bisphenol A-based (meth) acrylate compound such as acryloxypolyethoxypolypropoxy)phenyl)propane.

Specific examples of the compound represented by the above general formula (II) include, for example, EO-modified bisphenol A diacrylic acid wherein R ¹ and R ² are a hydrogen atom, Y is an exoethyl group, and n ¹ + n ² = 10 (average value). Ester (manufactured by Hitachi Chemical Co., Ltd., trade name: FA-321M).

The balance of the hydrophilic component and the hydrophobic component in the component (B) affects the resolution, the adhesion, the peeling property after hardening, and the like. From this point of view, in order to obtain a photosensitive element excellent in resolution, adhesion, and peeling property after curing, the component (B) preferably contains a polyalkylene glycol di(meth)acrylate. The polyalkylene glycol di(meth)acrylate is preferably, for example, a compound represented by the following general formula (VII), (VIII) or (IX).

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 an oxypropylene group, and s ¹ represents an integer of 1 to 30, r ¹ and r ^{The 2} series respectively represent integers from 0 to 30, and r ¹ +r ² (average value) are integers from 1 to 30.

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

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 from 1 to 30, and s ⁴ represents an integer from 1 to 30.

In the above general formulas (VII), (VIII) and (IX), when the structural unit (EO, oxyethylene unit) of the oxyethylene group and the structural unit (PO, oxypropylene unit) of the oxypropylene group are present in plural, the plural oxygen The ethylene unit and the oxypropylene unit may be present in a continuous block manner or irregularly, respectively. When the oxypropylene unit is a structural unit of oxyisopropenyl group, the propylene-based secondary carbon may be bonded to the oxygen atom, and the first-order carbon may be bonded to the oxygen atom.

The total number of oxyethylene units (r ¹ + r ² , r ³ and r ⁴ ) in the above general formulas (VII), (VIII) and (IX) are each independently an integer of from 1 to 30, preferably 4 or more. An integer, more preferably an integer of 5 or more. From the viewpoint of excellent masking reliability and photoresist 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 from 1 to 30, but from the resolution and The viewpoint of low sludge 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. From the viewpoint of resolution and low sludge, 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, for example, a vinyl compound in which R ⁸ and R ⁹ are a methyl group, r ¹ +r ² = 6 (average value), and s ¹ = 12 (average value) (Hitachi Chemical Industry Co., Ltd., trade name: FA-023M).

Specific examples of the compound represented by the above general formula (VIII) include, for example, a vinyl compound in which R ¹⁰ and R ¹¹ are a methyl group, r ³ = 6 (average value), and s ² + s ³ = 12 (average value) (Hitachi Chemical Industrial Co., Ltd., trade name: FA-024M).

Specific examples of the compound represented by the above formula (IX) include, for example, a vinyl compound in which R ¹² and R ¹³ are a hydrogen atom, r ⁴ =1 (average value), and s ⁴ = 9 (average value) (Xin Nakamura Chemical Industry) Co., Ltd., trade name: NK ester HEMA-9P).

These may be used alone or in combination of two or more.

The component (B) is preferably a urethane monomer containing a (meth) acrylate compound having a urethane bond or the like from the viewpoint of excellent masking property.

The above-mentioned ethyl urethane monomer is, for example, a (meth)acrylic monomer having a hydroxyl group at the β-position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6. An addition reaction product of a diisocyanate compound such as hexamethylene diisocyanate, ginseng ((meth)acryloxytetraethylene glycol isocyanate) hexamethylene terephthalate, EO-modified urethane di(methyl) Acrylate, and EO, PO modified ethyl urethane di(meth) acrylate. The EO-modified compound has a block structure of an oxyethylene group. Further, the PO-modified compound has a block structure of an oxypropylene group. EO modified ethyl urethane di(meth) acrylate For example, there is a new Nakamura Chemical Industry Co., Ltd. product name "UA-11". In addition, EO and PO-modified urethane di(meth)acrylate are, for example, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "UA-13". These may be used alone or in combination of two or more.

The component (B) is preferably a compound obtained by reacting a polyol with an α,β-unsaturated carboxylic acid from the viewpoint of excellent adhesion, resolution, and releasability. Such compounds are, for example, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO modification Trimethylolpropane tri(meth)acrylate, EO, PO modified trimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate . The EO-modified trimethylolpropane tri(meth)acrylate is, for example, manufactured by Sartomer Co., Ltd. under the trade name "SR-454". These may be used alone or in combination of two or more.

The component (B) is preferably a photopolymerizable compound having one ethylenically unsaturated bond, from the viewpoint of excellent adhesion, resolution, and releasability. The photopolymerizable compound having one ethylenically unsaturated bond preferably contains a compound represented by the following general formula (X).

In the general formula (X), R ¹⁴ is a hydrogen atom or a methyl group, preferably a hydrogen atom. The Z system is synonymous with Y in the above general formula (II), and is preferably an ethyl group. The k system 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 more preferably an integer of 6 to 10, from the viewpoint of development. Further, the aromatic ring in the above general formula (X) may have a substituent, and the substituents thereof have, for example, the same substituents as the aromatic ring in the above general formula (II).

The compound represented by the above general formula (X), specifically exemplified by nonylphenoxy polyethylenoxy (meth) acrylate, nonylphenoxy polyoxypropylene (meth) acrylate , butylphenoxypolyoxyethylene (meth) acrylate, butyl phenoxy polyoxypropylene (meth) acrylate.

The above nonylphenoxy polyoxyethylene (meth) acrylate is, for example, a nonyl phenoxy tetraoxyethylene (meth) acrylate, a nonyl phenoxy pentoxide (meth) acrylate, a nonyl benzene Oxyhexaoxyethylene (meth) acrylate, nonyl phenoxy hexaoxyethylene (meth) acrylate, nonyl phenoxy oxyethylene (meth) acrylate, nonyl phenoxy hexaoxyethylene (Meth) acrylate, nonylphenoxy oxyethylene (meth) acrylate, nonyl phenoxy undoxyl (meth) acrylate and nonyl phenoxy dodecyloxy (methyl) )Acrylate.

The above butylphenoxypolyoxyethylene (meth) acrylate, for example, butyl phenoxytetraoxyethylene (meth) acrylate, butyl phenoxy pentoxide (meth) acrylate, butyl Phenoxyhexaoxyethylene (meth) acrylate, butyl phenoxy heptaoxyethylene (meth) acrylate, butyl phenoxy ethoxy oxy (meth) acrylate, butyl phenoxy hexaoxy Ethylene (meth) acrylate, butyl phenoxy oxyethylene (meth) acrylate and butyl phenoxy unoxyethylene (meth) acrylate. These can be separate Use one type or a combination of two or more types.

The (B) component may contain a photopolymerizable compound having an ethylenically unsaturated bond other than the above. The other (B) photopolymerizable compound is, for example, a compound obtained by reacting a glycidyl group-containing compound with an α,β-unsaturated carboxylic acid, a phthalic acid compound, and an alkyl (meth)acrylate.

The above phthalic acid compounds are, for example, γ-chloro-β-hydroxypropyl-β'-(meth)acryloxyethyl-o-phthalate and β-hydroxyalkyl-β'- (Meth)acryloxyalkyl-o-phthalate. These may be used alone or in combination of two or more.

The amount of the photopolymerizable compound having an ethylenically unsaturated bond of the component (B) is preferably from 30 to 60 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). It is 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 the light sensitivity tend to be insufficient. When the amount is more than 60 parts by mass, the photosensitive layer after exposure curing tends to become brittle.

(photopolymerization initiator)

The photopolymerization initiator of the component (C) preferably contains a 2,4,5-triarylimidazole dimer from the viewpoint of excellent photosensitivity and adhesion. 2,4,5-triaryl imidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 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 dimer , 2-(o-chlorophenyl)-4,5-di(p-fluorophenyl)imidazole dimer, 2-(2,6-dichlorophenyl)-4,5-diphenylimidazolium Polymer, 2-(o-chlorophenyl)-4,5-di(p-fluorophenyl)imidazole dimer, 2-(o-bromophenyl)-4,5-di(p-iodobenzene) Imidazole dimer, 2-(o-chlorophenyl)-4,5-di(p-chloronaphthyl)imidazole dimer, 2-(o-chlorophenyl)-4,5-di P-chlorophenyl)imidazole dimer, 2-(o-bromophenyl)-4,5-di(o-chloro-p-methoxyphenyl)imidazole dimer, 2-(o-chloro Phenyl)-4,5-di(o,p-dichlorophenyl)imidazole dimer, 2-(o-chlorophenyl)-4,5-di(o,p-dibromophenyl)imidazole Dimer, 2-(o,m-dichlorophenyl)-4,5-di(p-chloronaphthyl)imidazole dimer, 2-(o,m-dichlorophenyl)-4,5 -diphenylimidazole dimer, 2-(o,p-dichlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2,4-di(p-甲Oxyphenyl)-5-phenylimidazole dimer, 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer, 2-(p-methylhydrogen Thiophenyl)-4,5-diphenylimidazole dimer, 2-(p-bromophenyl)-4,5-diphenylimidazole dimer, 2-(o-bromophenyl)- 4,5-bis(o,p-dichlorophenyl)imidazole dimer, 2-(m-bromophenyl)-4,5-diphenylimidazole , 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-di(o,p-dichlorophenyl)imidazole dimer, 2-(o-chlorophenyl)-4,5-di(o,p-dibromophenyl)imidazole dimer, 2-(o-bromophenyl)-4,5-di(o,p- Dichlorophenyl)imidazole dimer and 2,4,5-gin (o,p-dichlorophenyl)imidazole dimer. Among these, a 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer is preferred from the viewpoint of improving adhesion and light sensitivity.

In the 2,4,5-triaryl imidazole dimer, the substituents of the aryl groups of the two 2,4,5-triarylimidazoles are the same, providing a symmetric compound or, alternatively, providing an asymmetric compound.

When the component (C) contains a 2,4,5-triarylimidazole dimer, the content ratio is preferably from 70 to 100% by mass, more preferably from 85 to 100%, based on the total amount of the component (C). %, more preferably 90 to 100% by mass, particularly preferably 93 to 100% by mass. The 2,4,5-triaryl imidazole dimer is contained in this ratio, and the photosensitive element of this embodiment has more excellent adhesiveness and light sensitivity.

Photopolymerization initiator of component (C) In addition to the above 2,4,5-triarylimidazole dimer, other photopolymerization initiators can be used. Other photopolymerization initiators include, for example, aromatic ketones, p-aminophenyl ketones, anthraquinones, benzoin ether compounds, benzoin compounds, diphenylethylenedione derivatives, acridine derivatives , coumarin compound, oxime ester, N-aryl-α-amino acid compound, aliphatic polyfunctional thiol compound, fluorenyl phosphine oxide, thioxanthone, tertiary amine compound, can be combined These compounds are used.

The (C) photopolymerization initiator of the present embodiment preferably contains the above aromatic ketones in addition to the 2,4,5-triarylimidazole dimer, and preferably contains N,N'-tetraethyl. Base-4,4'-diaminobenzophenone (milaxone).

The amount of the photopolymerization initiator of the component (C) is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass based on 100 parts by mass of the total of the components (A) and (B). , particularly preferably 0.5 to 5 parts by mass. When the amount is less than 0.1 part by mass, the photosensitivity tends to be insufficient. When the amount is more than 20 parts by mass, the light absorption on the surface of the photosensitive resin composition increases during exposure, and the internal portion thereof Light hardening has a tendency to be insufficient.

The photosensitive resin composition may contain a photopolymerizable compound (oxycyclobutane compound or the like) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, and malachite green (Malachite green). a dye, a tribromophenylphosphonium, a colorless crystal violet such as a photochromic agent, a thermochromic preventive agent, a plasticizer such as p-toluenesulfonamide, a pigment, a filler, an antifoaming agent, a flame retardant, An additive such as a stabilizer such as 4-tert-butyl catechol, an inhibitor, a flat agent, a release accelerator, an antioxidant, a fragrance, an imaging agent, and a thermal crosslinking agent. These may be used alone or in combination of two or more. These additives may contain 0.0001 to 20 parts by mass each based on 100 parts by mass of the total of the components (A) and (B), within the range which does not affect the object of the embodiment.

The photosensitive resin composition is dissolved in methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, and propylene glycol monomethyl as necessary. In a solvent such as ether or a mixed solvent of these, a solution having a solid content of about 30 to 60% by mass is prepared.

The photosensitive layer 20 in the photosensitive element 1 of the present embodiment is formed by applying the photosensitive resin composition onto the support film 10 and removing the solvent. Among the coating methods, for example, a conventional method such as roll coating, comma coating, gravure coating, air knife coating, die coating, and bar coating can be used. Further, the solvent may be removed by, for example, treating at a temperature of 70 to 150 ° C for 5 to 30 minutes. Further, the amount of the residual organic solvent in the photosensitive layer 20 is preferably 2% by mass or less from the viewpoint of preventing the diffusion of the organic solvent in the subsequent step.

The thickness of the photosensitive layer 20 thus formed is preferably 3 to 25 μm, more preferably 5 to 25 μm, still more preferably 7 to 20 μm, and particularly preferably 10 to 15 μm. When the thickness is less than 3 μm, when the photosensitive layer 20 is laminated on the substrate for circuit formation, defects may occur easily or the tenting property may be insufficient. In the development and etching steps, the photoresist may be damaged, which may cause One of the reasons for the poor OPEN is that the manufacturing yield of printed circuit boards tends to decrease. On the other hand, when the thickness exceeds 25 μm, the resolution of the photosensitive layer 20 is insufficient, and the liquid movement of the etching liquid tends to be insufficient. In addition, the influence of side etching may become large, and it is difficult to manufacture a high-density printed circuit board.

Further, the photosensitive element 1 may be provided with a protective film (not shown) on the main surface opposite to the first main surface 12 that is in contact with the support film 10 of the photosensitive layer 20. Preferably, the protective film is a film having a lower adhesion between the photosensitive layer 20 and the protective film than the adhesive force between the photosensitive layer 20 and the support film 10, and a fish eye can be used. film. Specifically, for example, an inert polyolefin film such as polyethylene or polypropylene is used. From the viewpoint of the releasability from the photosensitive layer 20, a polyethylene film is preferred. The thickness of the protective film varies depending on the application, and is preferably about 1 to 100 μm.

In addition to the support film 10, the photosensitive layer 20, and the protective film, the photosensitive element 1 may further have an intermediate layer or a protective layer of a buffer layer, an adhesive layer, a light absorbing layer, and a gas barrier layer.

The photosensitive element 1 of the present embodiment can be stored, for example, in the original state or in a state in which the protective film is laminated on the photosensitive layer 20 and wound around the roll-shaped core. At this time, the support film 10 is in the outermost state, and it is preferable to wind it into a roll shape. End face of photosensitive member 1 wound into a roll shape From the viewpoint of end face protection, it is preferable to provide an end face spacer, and from the viewpoint of resistance to melting, it is preferable to provide a moisture-proof end face spacer. The bag method is preferably packaged in a black sheet having a low moisture permeability.

The material of the core is, for example, a plastic such as a polyethylene resin, a polypropylene resin, a polystyrene resin, a polyvinyl chloride resin, or an ABS (acrylonitrile-butadiene-styrene copolymer).

(Formation method of photoresist pattern)

The method for forming a photoresist pattern according to the present embodiment includes a method of laminating the photosensitive element 1 on the circuit formation substrate in the order of the photosensitive layer 20 and the support film 10; The active light is passed through the support film 10, irradiated to a predetermined portion of the photosensitive layer 20, and an exposure step of forming a photocured portion on the photosensitive layer 20; and a developing step of removing a portion of the photosensitive layer 20 other than the photocured portion.

In the laminating step, a method of laminating the photosensitive layer 20 on a substrate for forming a circuit, for example, when a protective film is present on the photosensitive layer 20, after removing the protective film, the photosensitive layer 20 is heated to about 70 to 130 ° C while A method in which a pressure of 0.1 to 1 MPa is adhered to a substrate for circuit formation, and lamination is performed. In this lamination step, it is also possible to laminate under reduced pressure. The laminated surface of the circuit-forming substrate is usually a metal surface, but is not particularly limited. In order to further improve the lamination property, the substrate for circuit formation may be subjected to preheat treatment.

Next, for the photosensitive layer 20 laminated in the above laminating step, the mask having the negative or positive mask pattern is aligned to the second main surface of the support film 10. Face 14, make it dense. Then, in the exposure step, the photosensitive layer 20 is irradiated with active light rays in an image form by the photomask and the support film 10, and a photocured portion is formed on the photosensitive layer 20. The light source of the above-mentioned active light is a known light source, and for example, a carbon arc lamp, a mercury vapor arc lamp, a high pressure mercury lamp, and a xenon lamp are effective for emitting ultraviolet rays or visible light. Further, a photo-curing portion may be formed on the photosensitive layer 20 using a laser direct drawing method.

Next, after the exposure step described above, the photomask is peeled off from the support film 10. Next, the support film 10 is peeled off from the photosensitive layer 20. In the development step, the unexposed portion (uncured portion) of the photosensitive layer 20 is removed by wet development or dry development of a developing solution such as an aqueous alkaline solution, an aqueous developing solution, or an organic solvent. Performing imaging can produce a photoresist pattern.

The alkaline aqueous solution is, for example, a thin solution of 0.1 to 5% by mass of sodium carbonate, a thin solution of 0.1 to 5% by mass of potassium carbonate, and a thin solution of 0.1 to 5% by mass of sodium hydroxide. The pH of the above alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature thereof can be adjusted in accordance with the developability of the photosensitive layer 20. Further, a surfactant, an antifoaming agent, an organic solvent or the like may be mixed in the alkaline aqueous solution. The methods of development include, for example, a dipping method, a spraying method, brushing, and slapping.

Further, the treatment after the development step may be re-hardened by heating at a temperature of about 60 to 250 ° C or an exposure amount of 0.2 to 10 J/cm ² if necessary.

(Manufacturing method of printed circuit board)

In the method of manufacturing a printed circuit board according to the present embodiment, a circuit for forming a circuit pattern having a photoresist pattern is formed by the method for forming a photoresist pattern. , by etching or electroplating. The photosensitive member of the present embodiment is particularly suitable for producing a printed circuit board by a method including a plating step, which is suitably used in a semi-additive process (SAP). The inventors of the present invention have reason to be suitable for use in SAP as described below. The line width of printed circuit boards produced by SAP has a very fine tendency compared to printed circuit boards produced by subtractive methods. Further, in the case of SAP, the photoresist shape is directly transferred into a plating line shape. When a printed circuit board having an extremely thin line pattern produced by SAP has a slight photoresist defect, the production yield tends to decrease. Therefore, the photosensitive element of the present embodiment is particularly suitable for use in SAP.

The etching liquid for etching is, for example, a copper chloride solution, a ferric chloride solution, and an alkali etching solution.

Electroplating is, for example, copper plating, solder plating, nickel plating, and gold plating.

After etching or electroplating, the photoresist pattern can be peeled off using, for example, an aqueous solution which is more alkaline than the alkaline aqueous solution used for development. As the strongly alkaline aqueous solution, for example, a 1 to 10% by mass aqueous sodium hydroxide solution and a 1 to 10% by mass aqueous potassium hydroxide solution can be used. The peeling method includes, for example, a dipping method and a spraying method. The printed circuit board on which the photoresist pattern is formed may be a multilayer printed circuit board or have a small diameter through hole.

Further, when plating a substrate for circuit formation including an insulating layer and a conductor layer formed on the insulating layer, it is necessary to remove a conductor layer other than the pattern. For the removal method, for example, after the photoresist pattern is peeled off, a method of etching is slightly performed or after the plating, followed by solder plating or the like, and then the photoresist pattern is peeled off, and the wiring portion is masked by soldering, and secondly, only the conductor can be etched. Layer eclipse The method of processing the etchant, and the like.

As described above, the photosensitive element of the present embodiment can be used for a printed circuit board.

(Method of Manufacturing Semiconductor Package Substrate)

The photosensitive element 1 of the present embodiment can be used for a package substrate including a hard substrate and an insulating film formed on the hard substrate. At this time, the photocured portion of the photosensitive layer 20 may be used as an insulating film. When the photocured portion of the photosensitive layer 20 is used as a solder resist for a semiconductor package, for example, after the development of the photoresist pattern is completed, it is preferably a high voltage in order to improve solder heat resistance, chemical resistance, and the like. The mercury lamp is irradiated with ultraviolet light or heated. When the ultraviolet ray is irradiated, the amount of irradiation can be adjusted as necessary, and for example, it can be irradiated with an irradiation amount of about 0.2 to 10 J/cm ² . When the photoresist pattern is heated, it is preferably in the range of about 100 to 170 ° C for about 15 to 90 minutes. Ultraviolet irradiation and heating can be performed simultaneously, or one of them can be carried out before the other is carried out. At the same time, when ultraviolet light is irradiated and heated, it is more preferably heated to 60 to 150 ° C from the viewpoint of effectively imparting heat resistance to soldering, chemical resistance, and the like.

The solder resist formed of the photosensitive element of the present embodiment has a protective film for wiring after soldering to the substrate, and is excellent in physical properties such as tensile strength and elongation, and heat-resistant punchability, and thus can be used as a semiconductor package. The permanent reticle is used.

As described above, the package substrate having the photoresist pattern is provided, and then assembly of the semiconductor element or the like (for example, wire bonding or solder connection) is performed, and then mounted on an electronic device such as a computer.

The present invention has been described in detail based on the embodiments thereof, but the present invention is not limited to the above embodiments. The present invention can be variously modified without departing from the spirit of the invention.

[Examples]

Hereinafter, the present invention will be described in detail based on the embodiments thereof, but the present invention is not limited to the embodiments.

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

(A) a binder polymer having the composition shown in the following Table 1 or 2 was synthesized.

The weight average molecular weight of the binder polymer is determined by gel permeation chromatography (GPC) and is derived using a calibration curve of standard polystyrene. The GPC conditions and the acid value measurement procedure are as follows, and the measurement results are shown in Table 1 or 2.

(GPC condition)

Pump: Hitachi L-6000 (manufactured by Hitachi, Ltd., trade name)

Pipe column: Gelpack GL-R420, Gelpack GL-R430, Gelpack GL-R440 (3 in total) (The above is Hitachi Chemical Co., Ltd., trade name)

Dissolution: tetrahydrofuran

Measuring temperature: 40 ° C

Flow rate: 2.05mL/min

Detector: Hitachi L-3300 type RI (made by Hitachi, Ltd., product name)

(acid value measurement method)

In the Erlenmeyer flask, about 1 g of the synthesized binder polymer was weighed, and after adding a mixed solvent (mass ratio: toluene/methanol = 70/30), an appropriate amount of the indicator phenolphthalein solution was added, and the solution was made up with a 0.1 N potassium hydroxide aqueous solution. For titration, the acid value was determined by the following formula (α).

x=10×Vf×56.1/(Wp×I)...(α)

In the formula (α), x represents an acid value (mgKOH/g), Vf represents a titration amount (mL) of a 0.1 N KOH aqueous solution, Wp represents a mass (g) of the resin solution after the measurement, and I represents a measurement. The proportion (% by mass) of the nonvolatile matter in the resin solution after that. The measurement results are shown in Tables 1 and 2.

Each component shown in the following Table 3 was prepared to prepare a photosensitive resin composition.

(production of photosensitive element)

A "PET" film shown in Table 4 or Table 5 was prepared as a support film for the photosensitive element. The total number of particles and the like of 5 μm or more contained in each PET film and the haze were measured as shown in Tables 4 and 5.

The total number of the above-mentioned particles and the like is a measured value of the number of particles or the like which are present in 5 mm or more of 1 mm ² unit by a polarizing microscope. The number of n (measurement number) at this time was 5. Further, the haze of the support film is a value measured in accordance with JIS K 7105. The thickness of these support films was 16 μm.

Next, a solution of the above photosensitive resin composition was applied to each PET film in a uniform thickness. Then, it was dried by a hot air convection dryer at 100 ° C for 2 minutes to remove the solvent to form a photosensitive layer. After drying, a photosensitive film was coated with a polyethylene protective film (trade name "NF-15", manufactured by TAMAPOLY Co., Ltd., thickness: 20 μm) to obtain a photosensitive element. The thickness of the photosensitive layer after drying was 15 μm.

(production of laminate)

The copper surface of a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., trade name "MLC-E-679") of a glass epoxy material having a copper foil (thickness: 35 μm) was laminated on both sides, and MEC etch BOND CZ-8100 was used. The surface was roughened (manufactured by MEC Co., Ltd.), and after pickling and washing with water, it was dried by air flow. The obtained copper-clad laminate was heated to 80 ° C to peel off the protective film, and the photosensitive layer was laminated to contact the copper surface to laminate the photosensitive member. Thus, a laminate in which a copper clad laminate, a photosensitive layer, and a support film are laminated in this order is obtained. Laminating system The heating was carried out at 120 ° C using a heating roll at a pressure of 0.4 MPa and a roll speed of 1.5 m/min. These laminate systems were used as test pieces of the test shown below.

(measurement of the minimum development time)

The photosensitive layer laminated on the substrate of 125 mm × 200 mm square was subjected to spray development, and the time at which the unexposed portion was completely removed was measured as the minimum development time. The measurement results are shown in Tables 4 and 5.

(Measurement of light sensitivity)

The support film of the test piece was placed on a Stouffer 21-segment exposure tablet (Step Tablets) as a negative image, and an exposure machine having a high-pressure mercury lamp (manufactured by OAK Co., Ltd., trade name "EXM-1201") was used at 100 mJ/ The irradiation energy of cm ² exposes the photosensitive layer. Next, the support film was peeled off, and a 1% by mass aqueous sodium carbonate solution at 30 ° C was spray-developed at twice the minimum development time to remove the unexposed portion, followed by development. The photosensitivity of the photosensitive resin composition was evaluated by measuring the number of stages of the exposed lattice sheet of the photocured film formed on the copper-clad laminate. The results are shown in Tables 4 and 5. The light sensitivity is expressed by the number of segments of the exposure grid, and the higher the number of segments of the exposure grid, the higher the light sensitivity.

(Measurement test of resolution)

In order to study the resolution, the image tool with the Stouffer 21-segment exposure grid and the negative image for the resolution evaluation have a line width/space width. A gas color layer type image tool of a wiring pattern of 2/2 to 30/30 (unit: μm) is attached to a support film of a test piece, and an exposure machine having a high pressure mercury lamp (made by OAK) is used. The product name "EXM-1201" was exposed by an irradiation energy of 5.0 after the Stouffer 21-segment exposure image was developed. Next, the support film was peeled off, and spray development was carried out using a 1% by mass aqueous sodium carbonate solution at 30 ° C for 4 times of the minimum development time, and the unexposed portion was removed, followed by development. The resolution is evaluated by the development process to completely remove the minimum width (unit: μm) between the line widths of the unexposed portions. The smaller the evaluation coefficient value of the resolution, the better the value. The results are shown in Tables 4 and 5.

(Evaluation of the side shape of the photoresist line)

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

A: smooth shape

B: slightly rough shape

C: rough shape

(measurement test of adhesion)

In order to study the adhesion, the image tool having the Stouffer 21-segment exposure grid and the negative image for the adhesion evaluation have a line width/space width of 2/1000 to 30/1000 (unit: μm). Gas pattern type of wiring pattern The image tool is attached to the support film of the test piece, and after exposure using a high-pressure mercury lamp exposure machine (manufactured by OAK Co., Ltd., trade name "EXM-1201"), the Stouffer 21-segment image is displayed. The number of remaining step segments is 8.0, and the exposure energy is exposed. Next, the support film was peeled off, and a spray development was carried out using a 1% by mass aqueous sodium carbonate solution at 30 ° C for 4 times of the minimum development time, and the unexposed portion was removed, followed by development. The adhesion is evaluated by the development process to completely remove the line width of the unexposed portion to the minimum width (unit: μm). The value of the adhesion evaluation coefficient is smaller as the value is better. The results are shown in Tables 4 and 5.

(Measurement test for the number of occurrences of photoresist defects)

In order to study the occurrence of photoresist defects, an image tool having a Stouffer 21-segment exposure grid and a gas chromatogram having a wiring pattern having a line width/space width of 10/30 (unit: μm) The exposure film having a high-pressure mercury lamp was used as a tool attached to the support film of the test piece, and the exposure energy after the development of the Stouffer 21-segment cell was 5.0. Next, the support film was peeled off, and sprayed with a 1% by mass aqueous sodium carbonate solution at 30 ° C for 2 times the minimum development time to remove the unexposed portion. Next, the number of photoresist defects was counted using a microscope. The line length is 1 mm, and the number of lines is 10 as the observation unit, and the average value when the number of n is 5 is taken as the number of occurrences of the photoresist defect. The results are shown in Tables 4 and 5.

As shown in Tables 4 and 5, the hazes of the PET films used in Examples 1 to 9 and Comparative Example 9 were substantially the same, but the PET films used in Examples 1 to 9 were present in particles of 5 μm or more in 1 mm ² units. The total number of the samples was one, and the PET film used in Comparative Example 9 (the total number of particles and the like was 28) was extremely small. Therefore, in the number of occurrences of the photoresist defect, the number of occurrences of the photoresist defect in Examples 1 to 9 was 0, which was a very small result compared with Comparative Example 9. Further, when a total of 318 supporting films of the particles of Comparative Example 10 were used, the number of occurrences of photoresist defects increased to 213. The shape of the photoresist side surface after the development of the examples 1 to 9 is smooth, and a good photoresist pattern is formed.

As shown in Table 4, the acid value and the weight average molecular weight of the component (A) used in Examples 1 to 9 were within an appropriate range, so that the minimum development time was extremely short, and the productivity of the printed circuit board was not lowered. The range of the weight average molecular weight determined by the above formula (I) is 1 to 53,900 when the acid value is 130 mgKOH/g, 1 to 36,000 when the acid value is 110 mgKOH/g, and 1 when the acid value is 90 mgKOH/g. ~24,000, when the acid price is 80mgKOH/g, it is 1~20,000.

1‧‧‧Photosensitive components

10‧‧‧Support film

12‧‧‧1st main face

14‧‧‧2nd main face

20‧‧‧Photosensitive layer (photosensitive resin composition layer)

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a preferred embodiment of a photosensitive element of the present invention, and Fig. 2 is a view showing a polarizing microscope photograph of a surface of a supporting film having particles having a diameter of 5 μm or more, and Fig. 3 is used for a plurality of diameters of 5 μm or more. A scanning-type micrograph of a resist pattern formed of a photosensitive element of a photosensitive layer on a support film such as a particle.

1‧‧‧Photosensitive components

10‧‧‧Support film

12‧‧‧1st main face

14‧‧‧2nd main face

20‧‧‧Photosensitive layer (photosensitive resin composition layer)

Claims (9)

A photosensitive element comprising a photosensitive element supporting a 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 has a diameter of 5 μm. The total number of particles and the aggregate having a diameter of 5 μm or more is 5/mm ² or less, and the photosensitive resin composition layer contains a binder polymer, a photopolymerizable compound having an ethylenically unsaturated bond, and a photopolymerization initiation. The acid value x of the binder polymer is 60 to 130 mgKOH/g, and the weight average molecular weight Mw satisfies the relationship expressed by the following formula (I), 10000 ≦ Mw < ^{4000e 0.02 x} (I) [in the formula (I), x is the acid value of the binder polymer, and Mw is the weight average molecular weight of the binder polymer. The photosensitive element of claim 1, wherein the photopolymerizable compound contains a compound represented by the following general formula (II), [In the formula (II), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, Y represents an alkylene group having 2 to 6 carbon atoms, and n ¹ and n ² each independently represent a positive integer, n ¹ + n ² is 4 to 40, and Ys of plural numbers may be the same or different from each other]. The photosensitive member according to claim 1 or 2, wherein the binder polymer has a divalent group represented by the following general formula (III), (IV) or (V), In the formulae (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 having 1 to 4 carbon atoms and a carbon number of 1 to 4; 3 alkoxy group, hydroxyl group or halogen atom, R ⁷ represents an alkyl group having 1 to 10 carbon atoms, p is an integer of 0 to 5, and when p is 2 or more, R ^{5 of} plural plural may be the same or different from each other] . The photosensitive member of claim 3, wherein the binder polymer further contains a divalent group represented by the following general formula (VI), In the formula (VI), R ¹⁵ represents a hydrogen atom or a methyl group, and R ¹⁶ represents an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group or a halogen atom, and q represents 0 to 0. An integer of 5, when q is 2 or more, R ^{16 in the} plural may be the same or different from each other]. The photosensitive member according to claim 1 or 2, wherein the photopolymerization initiator contains a 2,4,5-triarylimidazole dimer. A method for forming a photoresist pattern, characterized in that the photosensitive element according to any one of claims 1 to 5 is laminated on the circuit in the order of the photosensitive resin composition layer and the support film. a laminating step on the substrate for formation; an exposing step of forming a photocured portion on the photosensitive resin composition layer by irradiating the active light to a predetermined portion of the photosensitive resin composition layer through the support film; and removing the photohardening portion a developing step of the photosensitive resin composition layer other than the portion. A method of manufacturing a printed circuit board, comprising: forming a substrate for forming a circuit having a photoresist pattern by etching a pattern of a photoresist pattern according to claim 6 of the patent application; performing etching or plating A step of. A printed circuit board characterized by being manufactured by the manufacturing method of claim 7 of the patent application. A use of the photosensitive element according to any one of claims 1 to 5 for a printed circuit board.