TWI683179B - Photosensitive resin composition, photosensitive element using the same, method for forming resist pattern, and method for manufacturing printed circuit board - Google Patents

Abstract

An object of the present invention is to provide a photosensitive resin composition capable of forming a resist pattern with excellent resolution when a resist pattern is formed using a projection exposure method, and to provide a photosensitive resin composition containing (A ) Binder polymer, (B) photopolymerizable compound with ethylenic unsaturated bond, (C) photopolymerization initiator, (D) photosensitizer, and (E) polymerization inhibitor, said (E ) The content of the polymerization inhibitor is 0.03 parts by mass to 0.3 parts by mass relative to 100 parts by mass of the total solid content of the (A) binder polymer and the (B) photopolymerizable compound having an ethylenically unsaturated bond. Quality parts.

Description

Photosensitive resin composition, photosensitive element using the same, method for forming resist pattern, and method for manufacturing printed circuit board

The present disclosure relates to a photosensitive resin composition, a photosensitive element using the same, a method for forming a resist pattern, and a method for manufacturing a printed circuit board.

Conventionally, in the field of printed circuit board manufacturing, as a resist material used in etching processing, plating processing, etc., photosensitive resin compositions and photosensitive elements have been widely used, and the photosensitive elements have been provided on a support A layer formed using the photosensitive resin composition (hereinafter also referred to as "photosensitive resin layer") is formed, and a protective layer is disposed on the photosensitive resin layer.

The printed circuit board can be manufactured using the photosensitive element by, for example, the following procedure. That is, first, the photosensitive resin layer of the photosensitive element is laminated on a circuit-forming substrate such as a copper-clad laminate. At this time, the surface opposite to the surface where the photosensitive resin layer contacts the support (hereinafter also referred to as the "lower surface" of the photosensitive resin layer) (hereinafter also referred to as the "upper surface" of the photosensitive resin layer) and The circuit forming substrate is laminated so that the circuit-forming surfaces are in close contact. Therefore, when the protective layer is disposed on the upper surface of the photosensitive resin layer, this lamination operation is performed while peeling the protective layer. Moreover, lamination can be performed by heat-pressing the photosensitive resin layer on the circuit-forming substrate (normal pressure lamination method).

Next, the photosensitive resin layer is subjected to pattern exposure through a mask film or the like. At this time, the support is peeled at any timing before or after exposure. Thereafter, the unexposed portion of the photosensitive resin layer is dissolved or dispersed and removed by the developer. Next, an etching process or a plating process is performed to form a conductor pattern, and finally the cured portion of the photosensitive resin layer is peeled off and removed.

However, as the method of pattern exposure, in recent years, a projection exposure method has been cited, that is, actinic rays projecting a reticle image are irradiated on the photosensitive resin layer through a lens to expose the photosensitive resin layer. Compared with a contact exposure method using a mask film or the like, the projection exposure method can ensure high alignment. Therefore, in recent times, miniaturization of circuit formation in printed circuit boards has been required, and a projection exposure method has been paid close attention to.

As a light source used in the projection exposure method, an ultra-high pressure mercury lamp or the like is used. Generally, an exposure machine using i-ray monochromatic light with an exposure wavelength of 365 nm is often used, but sometimes an exposure machine using h-ray monochromatic light with an exposure wavelength of 405 nm, or ihg mixed rays is also used. As a projection exposure method, in order to obtain high resolution, a monochromatic light and split exposure method are generally used. Therefore, the irradiation energy due to monochromatic light is low, and the exposure time tends to become longer for split exposure. On the other hand, the contact exposure method generally uses ihg mixed rays and the collective exposure method, so there is a tendency that the exposure time becomes shorter. Therefore, from the viewpoint of improving efficiency at the time of mass production, the illuminance of the projection exposure machine is designed to be higher than that of the contact exposure machine, and each exposure time of the projection exposure machine is different from that of the contact exposure machine. In comparison, it tends to be shorter.

With the development of an exposure method using such a projection exposure method, research has begun on a photosensitive resin composition that can form a resist pattern having fine line adhesion (see, for example, Patent Document 1). [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2009/078380

[Problems to be solved by the invention]

In recent years, with the popularization of high-definition package substrates, further miniaturization of conductor patterns has been progressing, and it is required that the photosensitive resin composition used in the formation of such fine conductor patterns can form a resist pattern with excellent resolution. Moreover, there is a tendency that as the market for semiconductor packaging products requiring a resist pattern with excellent resolution continues to grow, the required characteristics of the photosensitive resin composition also change, compared with the light sensitivity that contributes to mass productivity In particular, more emphasis is placed on the resolution that contributes to yield. Therefore, especially in the field of semiconductor packaging and the like, there is a continuing need to improve the resolution even if the resolution is reduced by a unit of 1 μm. Furthermore, it is required that the photosensitive resin composition can form a resist pattern having a high “aspect ratio” defined as “the height of the formed image/the width of the formed image”.

In order to improve the resolution, a method for improving the cross-linking density of the photosensitive resin layer is studied. However, it is very difficult for the projection exposure machine to shorten the exposure time for each exposure, thereby improving the reactivity of the exposure section.

Moreover, when using a conventional photosensitive resin composition and exposing with a high-illuminance projection exposure machine, the peripheral portion of the desired resist pattern is also hardened, making it difficult to form a resist pattern with excellent resolution.

Therefore, a photosensitive resin composition suitable for the exposure environment of a projection exposure machine is required, and specifically, a photosensitive resin composition capable of forming a resist pattern with excellent resolution even when a projection exposure method is used.

The present disclosure is made in view of the problems of the prior art, and an object thereof is to provide a photosensitive resin composition capable of forming a resist pattern with excellent resolution when a resist pattern is formed using a projection exposure method And a photosensitive element using the same, a method for forming a resist pattern, and a method for manufacturing a printed circuit board. [Means to solve the problem]

In order to achieve the above object, the present disclosure provides a photosensitive resin composition containing (A) a binder polymer, (B) a photopolymerizable compound having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) A photosensitizer, and (E) a polymerization inhibitor, the content of the (E) polymerization inhibitor relative to the (A) binder polymer and the (B) having an ethylenically unsaturated bond From 100 parts by mass of the total solid content of the photopolymerizable compound, it is 0.03 parts by mass to 0.3 parts by mass.

The photosensitive resin composition having the above-described structure can form a resist pattern with excellent resolution when a resist pattern is formed using a projection exposure method. In particular, by setting the content of (E) component to 0.3 parts by mass or less, the exposure time can be shortened, which can contribute to the improvement of mass production efficiency. By setting the content of (E) component to 0.03 parts by mass or more, The photoreaction of the exposed portion can be sufficiently progressed, and by increasing the reaction rate, the swelling of the resist can be suppressed and the resolution can be improved. Therefore, the photosensitive resin composition of the present disclosure can be used as a photosensitive resin composition for projection exposure, and in particular, it can be used for manufacturing requiring high resolution, high aspect ratio, high adhesion, high image developability and high work It is used for the photosensitive resin composition for projection exposure of the ultra-high density wiring board of the nature.

式中，R⁵ 表示鹵素原子、氫原子、碳數1～20的烷基、碳數3～10的環烷基、胺基、芳基、巰基、碳數1～10的烷基巰基、烷基的碳數為1～10的羧基烷基、碳數1～20的烷氧基或雜環基，m表示以使m+n成為6以下的方式選擇的2以上的整數，n表示以使m+n成為6以下的方式選擇的0以上的整數，在n為2以上的整數的情況下，R⁵ 可分別相同亦可不同。Furthermore, in the photosensitive resin composition of the present disclosure, the (E) polymerization inhibitor may contain a compound represented by the following general formula (I). [Chemical 1]

In the formula, R ⁵ represents a halogen atom, a hydrogen atom, a C 1-20 alkyl group, a C 3-10 cycloalkyl group, an amine group, an aryl group, a mercapto group, a C 1-10 alkyl mercapto group, an alkyl group Carboxyalkyl group having 1 to 10 carbon atoms, alkoxy group having 1 to 20 carbon atoms or heterocyclic group, m represents an integer of 2 or more selected so that m+n becomes 6 or less, and n represents such that m+n becomes an integer of 0 or more selected as 6 or less. When n is an integer of 2 or more, R ⁵ may be the same or different.

When a resist pattern is formed using a projection exposure method with this photosensitive resin composition, a resist pattern with a higher resolution and a higher aspect ratio can be formed.

In addition, in the photosensitive resin composition of the present disclosure, the content of the (D) photosensitizer may have an ethylenically unsaturated bond with respect to the (A) binder polymer and the (B) The total solid content of the photopolymerizable compound of 100 parts by mass is 1.0 part by mass or less.

When the resist pattern is formed by the projection exposure method using this photosensitive resin composition, the deterioration of the shape of the resist pattern and the generation of resist feet can be suppressed, and the resolution can be improved.

The present disclosure also provides a photosensitive element including: a support; and a photosensitive resin layer formed on the support using the photosensitive resin composition of the present disclosure.

Since this photosensitive element includes the photosensitive resin layer formed using the photosensitive resin composition of the present disclosure, when a resist pattern is formed using a projection exposure method, it can form an excellent resolution and a high aspect ratio Resist pattern.

The present disclosure also provides a method for forming a resist pattern, which includes the steps of forming a photosensitive resin layer on a substrate using the photosensitive resin composition of the present disclosure or the photosensitive element of the present disclosure; using projection A step of exposing the actinic rays of the photomask image to the photosensitive resin layer through a lens; and a step of removing the unexposed portion of the photosensitive resin layer from the substrate by development.

This method of forming a resist pattern includes the step of forming a photosensitive resin layer using the photosensitive resin composition of the present disclosure or the photosensitive element of the present disclosure, and therefore, a projection pattern is used to form the resist pattern In the case of, a resist pattern with excellent resolution and high aspect ratio can be formed.

The present disclosure further provides a method of manufacturing a printed circuit board, which includes: performing etching or plating on the substrate formed with the resist pattern by the method for forming a resist pattern of the present disclosure to form a conductor pattern A step of.

The method of manufacturing the printed circuit board forms the resist pattern by the method of forming the resist pattern of the present disclosure, and therefore can form a resist pattern with excellent resolution and a high aspect ratio, which can provide suitable printing A method for manufacturing a printed circuit board with a high density of circuit boards. [Effect of invention]

According to the present disclosure, when a resist pattern is formed using a projection exposure method, a photosensitive resin composition capable of forming a resist pattern with excellent resolution and a high aspect ratio, and a photosensitive element using the same can be provided , A method of forming a resist pattern and a method of manufacturing a printed circuit board.

Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings as necessary. In addition, in the following embodiments, its constituent elements (including element steps and the like) are not necessarily required except when specifically stated and when it is considered to be clearly necessary in principle. That is, it should be interpreted as not improperly limiting the present disclosure. In addition, in this specification, "(meth)acrylic acid" means at least one of acrylic acid and methacrylic acid corresponding thereto. Moreover, the same applies to other similar expressions such as (meth)acrylate.

In addition, in this specification, the term "step" is not only an independent step, even if it cannot be clearly distinguished from other steps, if the desired effect of the step is achieved, it is also included in this term.

In addition, in this specification, the numerical range shown using "-" means the range including the numerical value described before and after "-" as a minimum value and a maximum value, respectively. In addition, in the numerical range described in stages in this specification, the upper limit value or the lower limit value of the numerical range of a certain stage may be replaced with the upper limit value or the lower limit value of the numerical range of another stage. In addition, in the numerical range described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples. In addition, in this specification, the term "layer" when viewed as a plan view includes, in addition to the structure of the shape formed on the entire surface, the structure of the shape formed on a part.

<Photosensitive resin composition> The photosensitive resin composition of this embodiment relates to (A) a binder polymer, (B) a photopolymerizable compound having an ethylenically unsaturated bond, and (C) photopolymerization initiation Agent, (D) light sensitizer, and (E) polymerization inhibitor, the content of the (E) polymerization inhibitor is ethylenically unsaturated with respect to the (A) binder polymer and the (B) The total solid content of the photopolymerizable compound of the bond is 0.03 parts by mass to 0.3 parts by mass of the photosensitive resin composition for 100 parts by mass. Hereinafter, each component used in the photosensitive resin composition of the present embodiment will be described in more detail.

[(A) Binder Polymer] Examples of the (A) binder polymer (hereinafter also referred to as "(A) component") that can be used in the photosensitive resin composition of this embodiment include acrylic resins. , Styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, phenol resin, etc. From the standpoint of further improving the alkali developability, an acrylic resin may be contained. These can be used alone or in combination of two or more.

(A) The binder polymer can be produced by, for example, radically polymerizing a polymerizable monomer. That is, it can also be said that (A) the binder polymer has a structural unit derived from the polymerizable monomer. Examples of the polymerizable monomer include styrene, vinyl toluene, α-methylstyrene, and other polymerizable styrene derivatives substituted in the α-position or aromatic ring, and diacetone acrylamide. Ethers such as acrylamide, acrylonitrile, vinyl-n-butyl ether, vinyl alcohol, alkyl (meth)acrylate, benzyl methacrylate, etc., benzyl (meth)acrylate, (meth)acrylic acid Tetrahydrofurfuryl, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, -2,2 (meth)acrylic acid ,2-trifluoroethyl, (meth)acrylic acid-2,2,3,3-tetrafluoropropyl ester, (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furanyl (methyl ) Acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate and other maleic acid monoesters, Fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propionic acid, etc. These can be used alone or in combination of two or more.

Among these, from the standpoint of further improving developability, it may be an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include compounds represented by the following general formula (II) and compounds in which the alkyl groups of these compounds are substituted with hydroxyl groups, epoxy groups, halogen groups, and the like. H ₂ C=C(R ⁶ )-COOR ⁷ (II)

In the general formula (II), R ⁶ represents a hydrogen atom or a methyl group, and R ⁷ represents an alkyl group having 1 to 12 carbon atoms. Examples of the C 1-12 alkyl represented by R ⁷ include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and undecane Group, dodecyl group, structural isomers of these groups, etc.

Examples of the alkyl (meth)acrylate represented by the general formula (II) include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and (meth) ) Butyl acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, etc. These can be used alone or in combination of two or more.

Moreover, from the standpoint of further improving the alkali developability, (A) the binder polymer may contain a carboxyl group. The (A) binder polymer containing a carboxyl group can be produced by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer, for example. Among them, from the standpoint of further improving the alkali developability, the polymerizable monomer having a carboxyl group may be (meth)acrylic acid or methacrylic acid. Moreover, the acid value of the (A) binder polymer containing a carboxyl group can also be 50 mgKOH/g to 250 mgKOH/g.

(A) The carboxyl group content of the binder polymer (a compounding ratio of the polymerizable monomer having a carboxyl group used in the binder polymer to the total amount of polymerizable monomers), self-alkali developing property and alkali resistance Considering a well-balanced standpoint, it may be 12% by mass to 50% by mass, 12% by mass to 40% by mass, 15% by mass to 35% by mass, or 15% by mass to 30% by mass. If the content of the carboxyl group is 12% by mass or more, the alkali developability tends to be improved, and if it is 50% by mass or less, the alkali resistance tends to be excellent.

In addition, the content of the structural unit derived from the polymerizable monomer having a carboxyl group in the binder polymer (A) is related to the compounding ratio of the polymerizable monomer having a carboxyl group, so it may be 12% by mass to 50% by mass , 12% by mass to 40% by mass, 15% by mass to 35% by mass, or 15% by mass to 30% by mass.

Moreover, from the standpoint of further improving adhesion and chemical resistance, (A) the binder polymer may use styrene or a styrene derivative as a polymerizable monomer. In the case where the styrene or styrene derivative is used as a polymerizable monomer, the content (from the styrene or benzene used in the binder polymer) is considered from the standpoint of better adhesion and chemical resistance The blending ratio of the ethylene derivative with respect to the total amount of polymerizable monomers) may be 10% by mass to 60% by mass, or 15% by mass to 50% by mass. If the content is 10% by mass or more, there is a tendency for adhesion to be improved; if it is 60% by mass or less, there is a tendency that the peeling sheet becomes larger during development and the time required for peeling is suppressed from being prolonged . Here, in this specification, "chemical resistance" refers to chemicals (developing solution, water, etching solution, etc.) used in a method of forming a resist pattern or a method of manufacturing a printed circuit board described later. Tolerance.

In addition, the content of the structural unit derived from styrene or a styrene derivative in the binder polymer (A) is related to the compounding ratio of the styrene or styrene derivative, and therefore may be 10% by mass to 60% by mass , 15% to 50% by mass.

Furthermore, from the standpoint of better resolution and aspect ratio, (A) the binder polymer may use benzyl (meth)acrylate as the polymerizable monomer. From the standpoint of further improving the resolution and aspect ratio, the content of (A) benzyl (meth)acrylate in the binder polymer may be 15% by mass to 50% by mass.

These binder polymers can be used alone or in combination of two or more. Examples of (A) binder polymers when two or more kinds are used in combination include, for example, two or more binder polymers containing different polymerizable monomers, and two or more binder polymers having different weight average molecular weights. , Two or more binder polymers with different dispersion.

(A) The binder polymer can be produced by a usual method. Specifically, for example, it can be produced by radical polymerization of alkyl (meth)acrylate, (meth)acrylic acid, styrene, and the like.

(A) The weight average molecular weight of the binder polymer may be 20,000 to 300,000, 40,000 to 150,000, 40,000 to 120,000, or 50,000 to 80,000 from the standpoint of improving the mechanical strength and alkali developability in a balanced manner. (A) If the weight average molecular weight of the binder polymer is 20,000 or more, the developer resistance tends to be more excellent; if it is 300,000 or less, there is a tendency to suppress the development time from becoming longer. In addition, the weight average molecular weight in this specification is a value measured by gel permeation chromatography (Gel Permeation Chromatography, GPC), and converted by the calibration curve made using standard polystyrene.

(A) The content of the binder polymer may be 30 parts by mass to 80 parts by mass, 40 parts by mass to 75 parts by mass relative to 100 parts by mass of the total solid content of the component (A) and the component (B) described later. Or 50 to 70 parts by mass. When the content of the component (A) is within this range, the coating properties of the photosensitive resin composition and the strength of the photocured product become better.

[(B) Photopolymerizable compound having an ethylenically unsaturated bond] The photosensitive resin composition of this embodiment contains (B) a photopolymerizable compound having an ethylenically unsaturated bond (hereinafter also referred to as "(B) component "). (B) If a component is a photopolymerizable compound which has at least one ethylenic unsaturated bond in a molecule, it can be used without particular limitation.

Examples of the component (B) include a compound obtained by reacting a polyhydric alcohol with an α,β-unsaturated carboxylic acid, a bisphenol-type (meth)acrylate compound, and a (methyl) group having a urethane bond Carbamate monomers such as acrylate compounds, nonylphenoxyethyloxy (meth)acrylate, nonylphenoxy octaethyloxy (meth)acrylate, γ-chloro- β-Hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl phthalate Ester, β-hydroxypropyl-β'-(meth)acryloxyethyl phthalate, alkyl (meth)acrylate, etc. These can be used alone or in combination of two or more.

In the above, the component (B) may contain a bisphenol-type (meth)acrylate compound from the standpoint of improving the balance between the resolution, the adhesion, and the inhibition of the resist footing. The bisphenol-type (meth)acrylate compound may also be a compound represented by the following general formula (III). [Chem 2]

In the general formula (III), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group. X and Y independently represent ethylidene or propylene, XO and YO independently represent oxyethylidene (hereinafter sometimes referred to as "EO group") or oxypropylene (hereinafter sometimes referred to as "PO base"). p ₁ , p ₂ , q ₁ and q ₂ each independently represent a value of 0-40. However, both p ₁ +q ₁ and p ₂ +q ₂ are 1 or more. When X is ethylidene and Y is propylidene, p ₁ +p ₂ is 1-40, and q ₁ +q ₂ is 0-20. When X is propylidene and Y is ethylidene, p ₁ +p ₂ is 0-20, and q ₁ +q ₂ is 1-40. p ₁ , p ₂ , q ₁ and q ₂ represent the number of structural units of an EO group or a PO group, so if it is a single molecule, it represents an integer value; if it is a collection of multiple molecules, it represents a rational number as an average value. In addition, the EO group and the PO group may be present continuously and in blocks, or may be present randomly.

In the general formula (III), when X and Y are both ethylidene groups, p ₁ +p ₂ +q ₁ +q ₂ may be 1-20, ₁ from the viewpoint of more excellent self-resolution and adhesion. ~10, or 1~7.

Examples of the compound represented by the general formula (III) include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane and 2,2-bis(4-( (Meth)acryloyloxypolypropyloxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropyloxy)phenyl)propane, etc. These can be used alone or in combination of two or more.

Regarding commercially available bisphenol-type (meth)acrylate compounds, for example, 2,2-bis(4-(methacryloxydiethoxy)phenyl)propane (Shinakamura Chemical "BPE-200" manufactured by Industrial Co., Ltd.), 2,2-bis(4-(methacrylacetoxypentethoxy)phenyl)propane ("BPE-200 manufactured by Shin Nakamura Chemical Industry Co., Ltd. 500", or "FA-321M" manufactured by Hitachi Chemical Co., Ltd.), 2,2-bis(4-(methacryloxypentadecyloxy)phenyl)propane (Xinzhongcun Chemical Industry Co., Ltd. "BPE-1300" manufactured by the company), 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane ("BP-2EM" manufactured by Kyoeisha Chemical Co., Ltd. ( EO base: 2.6 (average))) etc.

From the standpoint of further improving chemical resistance, the content of the bisphenol-type (meth)acrylate compound can be 1% by mass to 50% by mass relative to the total solid content of the components (A) and (B). %, 1% by mass to 45% by mass, 1% by mass to 40% by mass, or 3% by mass to 25% by mass.

Moreover, from the standpoint of further improving the chemical resistance, the content of the bisphenol-type (meth)acrylate compound can be 30% by mass to 99% by mass relative to the total solid content of the (B) component. % By mass to 97% by mass, or 60% by mass to 95% by mass.

Furthermore, from the standpoint of making the resolution better, the content of the compound represented by the general formula (III) having the total number of EO groups and PO groups of 1 to 7 can be relative to the solid content of the components (A) and (B) The total amount is 1% by mass to 30% by mass, 2% by mass to 28% by mass, or 3% by mass to 25% by mass.

Furthermore, from the standpoint of further improving the substrate's conformability to irregularities, a compound obtained by reacting a polyol with an α,β-unsaturated carboxylic acid may be contained. As such a compound, for example, a polyolefin diol di(meth)acrylate having both an EO group and a PO group in the molecule can be used. The content of the compound obtained by reacting a polyol with α,β-unsaturated carboxylic acid may be 1% by mass to 10% by mass, or 3% by mass relative to the total solid content of the components (A) and (B). % ~ 7 mass%. Furthermore, the content of the compound obtained by reacting a polyol with an α,β-unsaturated carboxylic acid may be 1% by mass to 30% by mass, or 3% by mass to 20 relative to the total solid content of the component (B) quality%.

In addition, in the molecule of the polyolefin diol di(meth)acrylate having both the EO group and the PO group, the EO group and the PO group may be present continuously and in blocks, or may be present randomly. Moreover, the PO group may be any of oxy-n-propylene or oxyisopropylene. In addition, in the (poly)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.

Commercially available polyolefin diol di(meth)acrylates having both EO groups and PO groups include, for example, EO groups: 6 (average) and PO groups: 12 (average ) Polyolefin diol di(meth)acrylate ("FA-023M", "FA-024M" manufactured by Hitachi Chemical Co., Ltd.), etc.

(B) The content of the component may be 20 parts by mass to 70 parts by mass, 25 parts by mass to 60 parts by mass, or 30 parts by mass relative to 100 parts by mass of the total solid content of the components (A) and (B). 50 parts by mass. When the content of the component (B) is within this range, in addition to the resolution, adhesiveness, and suppression of resist footing of the photosensitive resin composition, the photosensitivity and coating properties become better.

[(C) Photopolymerization Initiator] The photosensitive resin composition of this embodiment contains at least one (C) photopolymerization initiator (hereinafter also referred to as "(C) component"). The component (C) is not particularly limited as long as it can polymerize the component (B), and can be appropriately selected from photopolymerization initiators generally used.

Examples of the component (C) include 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1 and 2-methyl-1-[4-( Methylthio)phenyl]-2-morpholinyl-acetone-1 and other aromatic ketones, alkyl anthraquinones and other quinones, benzoin alkyl ethers and other benzoin ether compounds, benzoin, alkyl benzoin and other benzoin compounds, benzyl Benzyl derivatives such as dimethyl ketal, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole di 2,4,5-triarylimidazole dimers such as polymers, and acridine derivatives such as 9-phenylacridine and 1,7-(9,9'-acridinyl)heptane. These may be used alone or in combination of two or more.

Among these, 2,4,5-triarylimidazole dimer may be contained from the standpoint of further improving the resolution. Examples of the 2,4,5-triarylimidazole dimer include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer and 2-(o-chlorophenyl)-4. ,5-bis-(m-methoxyphenyl)imidazole dimer, 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, etc. These may contain 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer.

As 2,4,5-triarylimidazole dimer, for example, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbisimidazole can be used as B-CIM ( It is manufactured by Baotugu Chemical Industry Co., Ltd. and its product name is obtained commercially.

The component (C) may contain at least one 2,4,5-triarylimidazole dimer from the viewpoint of further improving the photosensitivity and adhesion and further suppressing the light absorption of the component (C), or Contains 2-(2-chlorophenyl)-4,5-diphenylimidazole dimer. In addition, the structure of the 2,4,5-triarylimidazole dimer may be symmetrical or asymmetrical.

(C) The content of the component may be 0.01 to 30 parts by mass, 0.1 to 10 parts by mass, and 1 to 7 parts by mass relative to 100 parts by mass of the total solid content of the components (A) and (B). Part by mass, 1 part by mass to 6 parts by mass, 1 part by mass to 5 parts by mass, or 2 parts by mass to 5 parts by mass. If the content of the component (C) is 0.01 parts by mass or more, the light sensitivity, resolution, and adhesion tend to improve; if it is 30 parts by mass or less, the shape of the resist pattern tends to be more excellent.

[(D) Photosensitizer] The photosensitive resin composition of the present embodiment contains (D) photosensitizer (hereinafter also referred to as "(D) component"). By containing the component (D), the absorption wavelength of the actinic rays used in the exposure can be effectively used.

Examples of the component (D) include pyrazolines, dialkylaminobenzophenones, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, and thiazoles. , Benzothiazoles, triazoles, stilbene, triazines, thiophenes, naphthalimides, triarylamines, etc. These can be used alone or in combination of two or more.

(D) The content of the component may be 1.0 parts by mass or less, 0.5 parts by mass or less, 0.15 parts by mass or less, 0.12 parts by mass or less relative to 100 parts by mass of the total solid content of the components (A) and (B) 0.1 parts by mass or less. If the content of the component (D) is 1.0 part by mass or less relative to 100 parts by mass of the total solid content of the component (A) and the component (B), there is a tendency that the shape deterioration of the resist pattern can be further suppressed And the generation of resist footing makes the resolution better. In addition, from the standpoint that high light sensitivity and high resolution are more easily obtained, the lower limit of the content of the (D) component can be 0.01 relative to 100 parts by mass of the total solid content of the (A) component and (B) component Above mass.

[(E) Polymerization Inhibitor] The photosensitive resin composition of this embodiment contains (E) a polymerization inhibitor (hereinafter also referred to as "(E) component"). By containing the (E) component, the exposure required for photocuring the photosensitive resin composition can be adjusted to the exposure most suitable for exposure by a projection exposure machine.

From the standpoint of further improving the resolution, the component (E) may contain a compound represented by the following general formula (I). [Chemical 3]

In the general formula (I), R ⁵ represents a halogen atom, a hydrogen atom, a C 1-20 alkyl group, a C 3-10 cycloalkyl group, an amine group, an aryl group, a mercapto group, and a C 1-10 alkyl group A mercapto group, an alkyl group, a carboxyalkyl group having 1 to 10 carbon atoms, an alkoxy group or a heterocyclic group having 1 to 20 carbon atoms, m represents an integer of 2 or more selected so that m+n becomes 6 or less, n represents an integer of 0 or more selected so that m+n becomes 6 or less. When n is an integer of 2 or more, R ⁵ may be the same or different. In addition, the aryl group may be substituted with an alkyl group having 1 to 20 carbon atoms.

From the standpoint of further improving the compatibility with the component (A), R ⁵ may be a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. The alkyl group having 1 to 20 carbon atoms represented by R ⁵ may be an alkyl group having 1 to 4 carbon atoms. From the standpoint of further improving the resolution, m may be 2 or 3, or 2.

Examples of the compound represented by the general formula (I) include catechol, resorcinol (resorcinol), 1,4-hydroquinone, 2-methylcatechol and 3-methyl Catechol, 4-methylcatechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol Catechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, 3- Alkyl catechols such as tertiary butyl catechol, 4-tertiary butyl catechol, 3,5-di-tertiary butyl catechol, 2-methyl resorcinol, 4-methyl Resorcinol, 5-methylresorcinol (orcinol), 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propanol Alkyl groups such as resorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, 4-tert-butylresorcinol Resorcinol, methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, etc. Alkyl hydroquinone, gallic acid, pyrogallol, etc. These can be used alone or in combination of two or more.

The compound represented by the general formula (I) may be an alkyl catechol from the standpoint of further improving the resolution.

(E) The content of the component is 0.03 parts by mass to 0.3 parts by mass relative to 100 parts by mass of the total solid content of the components (A) and (B), and may also be 0.03 parts by mass to 0.2 parts by mass, 0.05 parts by mass ~0.15 parts by mass, or 0.05 parts by mass to 0.1 parts by mass. By setting the content of the (E) component to 0.3 parts by mass or less, the exposure time can be shortened, which can contribute to the improvement of mass production efficiency; by setting it to 0.03 parts by mass or more, the exposure part can be sufficiently conducted The photoreaction can suppress the swelling of the resist by increasing the reaction rate and make the resolution better.

Furthermore, the content of the component (E) may be 0.05 parts by mass to 0.4 parts by mass, 0.05 parts by mass to 0.2 parts by mass, or 0.05 parts by mass to 0.1 parts by mass relative to 100 parts by mass of the solid content of the component (A). When the content of the (E) component is 0.05 parts by mass or more relative to the (A) component, there is a tendency that the thermal stability of the photosensitive resin composition can be improved; in the case of 0.4 parts by mass or less, there is The tendency of the photosensitive resin composition to turn yellow can be suppressed.

[Other components] The photosensitive resin composition of the present embodiment may also contain the following components in an amount of 0.01 to 20 parts by mass relative to 100 parts by mass of the total solid content of the components (A) and (B), if necessary: Malachite green, Victoria pure blue, bright green, methyl violet and other dyes, tribromophenyl ash, leuco crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, o-chloroaniline, the first Photochromic agents such as tributylcatechol, thermal color development inhibitors, p-toluenesulfonamide and other plasticizers, pigments, fillers, defoamers, flame retardants, adhesion-imparting agents, leveling agents, Additives such as peeling accelerators, antioxidants, perfumes, developers, thermal cross-linking agents. These additives may be used alone or in combination of two or more.

Furthermore, the photosensitive resin composition of the present embodiment may contain at least one organic solvent if necessary. As the organic solvent, a commonly used organic solvent can be used without particular limitation. Specific examples include organic solvents such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, and propylene glycol monomethyl ether. Solvent or a mixed solvent of these. These can be used alone or in combination of two or more.

The photosensitive resin composition of this embodiment can be prepared as a solid component by dissolving (A) component, (B) component, (C) component, (D) component, and (E) component in the organic solvent, for example A 30% by mass to 60% by mass solution (hereinafter also referred to as "coating liquid") is used. In addition, in this specification, the "solid content" refers to the components in the composition other than volatile substances such as moisture and organic solvents described later. That is, the solid component is also included in a liquid state, a caramel state, and a wax state at room temperature near 25°C, and does not mean that it must be a solid. Here, the "volatile substance" refers to a substance having a boiling point of 155°C or lower at atmospheric pressure.

The coating liquid can be used for forming a photosensitive resin layer as described below, for example. For example, by coating the coating liquid on the surface of a support such as a polymer film or a metal plate described later and drying it, a photosensitive resin layer derived from a photosensitive resin composition can be formed on the support .

Examples of the metal plate include a metal plate containing an iron-based alloy such as copper, copper-based alloy, nickel, chromium, iron, or stainless steel. From the standpoint of further improving durability, it may include copper, a copper-based alloy, or Metal plate of iron alloy.

<Photosensitive element> The photosensitive element of this embodiment relates to a photosensitive element including a support and a photosensitive resin layer formed on the support using the photosensitive resin composition. The photosensitive element 1 of the present embodiment is a schematic cross-sectional view showing an example thereof in FIG. 1, and includes a support 2 and a photosensitive resin layer 3 formed on the support 2 and derived from the photosensitive resin composition. , And includes other layers such as the protective layer 4 provided as necessary.

[Support] As the support, for example, a polymer film having heat resistance and solvent resistance such as polyester such as polypropylene, polyethylene, and polyethylene terephthalate can be used.

The thickness of the support may be 1 μm to 100 μm, 1 μm to 50 μm, or 1 μm to 30 μm. When the thickness of the support is 1 μm or more, there is a tendency to prevent the support from breaking when the support is peeled. Moreover, when the thickness of the support is 100 μm or less, there is a tendency to suppress the decrease in resolution.

[Protective Layer] The photosensitive element 1 may further include a protective layer 4 as necessary, and the protective layer 4 covers the surface of the photosensitive resin layer 3 opposite to the surface facing the support 2.

The protective layer may be a film having a low fisheye-like white spot, and has a lower adhesion to the photosensitive resin layer than the support to the photosensitive resin layer.

Here, the "fisheye-shaped white dot" means that when the film constituting the protective layer is thermally melted and the film is produced by kneading, extrusion, biaxial stretching casting method, etc., it is incorporated into the film Foreign material, undissolved material, oxidative degradation material, etc. That is, the "low fisheye-like white spot" means that there are few foreign substances in the film.

Specifically, as the protective layer, a polymer film having heat resistance and solvent resistance such as polyester such as polypropylene, polyethylene, and polyethylene terephthalate can be used. Examples of commercially available products include ALPHAN MA-410 and E-200C manufactured by Oji Paper Co., Ltd., polypropylene films manufactured by Shin-Etsu Film Co., Ltd., and PS series such as PS-25 manufactured by Teijin Co., Ltd. Ethylene phthalate film. In addition, the protective layer may be the same as the support.

The thickness of the protective layer may be 1 μm to 100 μm, 5 μm to 50 μm, 5 μm to 30 μm, or 15 μm to 30 μm. When the thickness of the protective layer is 1 μm or more, when the protective layer is peeled off while the photosensitive resin layer and the support are laminated on the substrate, the tendency of the protective layer to crack can be suppressed. Furthermore, in terms of easy economic benefits, it may be 100 μm or less.

[Manufacturing method of photosensitive element] The photosensitive element of this embodiment can be manufactured as follows, for example. It can be manufactured by a manufacturing method including the steps of: preparing a coating solution in which the photosensitive resin composition is dissolved in the organic solvent; applying the coating solution on a support to form a coating The step of the cloth layer; the step of drying the coating layer to form a photosensitive resin layer.

The coating liquid can be applied to the support by, for example, known methods such as roll coating, notch coating, gravure coating, air knife coating, die coating, bar coating, and spray coating.

In addition, the drying of the coating layer is not particularly limited as long as at least a part of the organic solvent can be removed from the coating layer, and it can be dried at 70°C to 150°C for 5 to 30 minutes. From the viewpoint of suppressing the diffusion of the organic solvent in the subsequent steps, the amount of residual organic solvent in the photosensitive resin layer after drying can be 2 based on the total amount of the photosensitive resin composition other than the organic solvent Mass% or less.

The thickness of the photosensitive resin layer in the photosensitive element can be appropriately selected according to the application, and it can be 1 μm to 200 μm, 5 μm to 100 μm, or 10 μm to 50 μm in terms of the thickness after drying. When the thickness of the photosensitive resin layer is 1 μm or more, industrial coating tends to be easy and productivity tends to be improved. In addition, when the thickness of the photosensitive resin layer is 200 μm or less, there is a tendency that the light sensitivity is high and the photocurability of the bottom of the resist is excellent, so that a resist pattern with excellent resolution and aspect ratio can be formed.

In particular, when a photosensitive resin layer is exposed using a projection exposure method to form a resist pattern, the thickness of the photosensitive resin layer in the photosensitive element is the thickness after drying from the viewpoint of more excellent resolution It may be less than 30 μm or less than 25 μm. The lower limit of the thickness of the photosensitive resin layer is not particularly limited as long as the photosensitive resin layer can be formed. From the viewpoint of further increasing the output, the thickness after drying may be 1 μm or more. , 5 μm or more, or 7 μm or more.

The photosensitive element of this embodiment may further include an intermediate layer such as a buffer layer, an adhesive layer, a light-absorbing layer, or a gas barrier layer, if necessary.

The form of the photosensitive element of this embodiment is not particularly limited. For example, it may be in the form of a sheet or may be wound in a roll shape on the core. In the case of winding in a roll shape, the support may be wound so as to be outside. Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS (acrylonitrile-butadiene-styrene copolymer).

The end face of the roll-shaped photosensitive element roll obtained as described above can be provided with an end face separator from the standpoint of protecting the end face; and a moisture-proof end face separator can be provided from the standpoint of resistance to edge fusion. As a packaging method, it can be packaged in a black sheet with low moisture permeability.

The photosensitive element of this embodiment can be suitably used in, for example, a method of forming a resist pattern described later.

<Method of Forming Resist Pattern> The method of forming a resist pattern of this embodiment includes: (i) a step of forming a photosensitive resin layer on a substrate using the photosensitive resin composition or the photosensitive element (Hereinafter also referred to as "(i) photosensitive resin layer forming step"); (ii) a step of exposing the photosensitive resin layer through a lens using actinic rays projecting a photomask image (hereinafter also referred to as " (Ii) Exposure step"); (iii) The step of removing the unexposed portion of the photosensitive resin layer from the substrate by development (hereinafter also referred to as "(iii) development step"), and may also include other step.

(I) Photosensitive resin layer forming step In the photosensitive resin layer forming step, the photosensitive resin layer or the photosensitive element is used to form a photosensitive resin layer on a substrate. The substrate is not particularly limited. Generally, a circuit-forming substrate including an insulating layer and a conductive layer formed on the insulating layer, or an underlying substrate (substrate for lead frame) such as an alloy substrate is used.

As a method of forming a photosensitive resin layer on a substrate, for example, a method of applying a coating liquid containing the photosensitive resin composition and then drying it, a method of using the photosensitive element, and the like are mentioned. In the case of using a photosensitive element having a protective layer, after removing the protective layer, the photosensitive resin layer of the photosensitive element can be heated while being pressure-bonded to the substrate, thereby forming the sensitivity on the substrate Resin layer. Thereby, a laminate including the substrate, the photosensitive resin layer, and the support in this order is obtained.

When the photosensitive resin layer forming step is performed using a photosensitive element, it can be performed under reduced pressure from the standpoint of self-adhesion and followability. Heating during crimping can be performed at a temperature of 70°C to 130°C, and crimping can be performed at a pressure of 0.1 MPa to 1.0 MPa (1 kgf/cm ² to 10 kgf/cm ² ). These conditions can be as required And suitable for selection. In addition, if the photosensitive resin layer of the photosensitive element is heated to 70° C. to 130° C., it is not necessary to preheat the substrate in advance, but in order to further improve the adhesion and followability, the substrate may be preheated. .

(Ii) Exposure step In the exposure step, using actinic rays projecting a reticle image, at least a portion of the photosensitive resin layer formed on the substrate is irradiated with actinic rays via a lens, thereby exposing the actinic rays The part is photohardened to form a photohardened part (latent image). When forming the photosensitive resin layer using the photosensitive element, when the support existing on the photosensitive resin layer is transparent to actinic rays, actinic rays may be irradiated through the support, but When the support is light-shielding with respect to actinic rays, the photosensitive resin layer is irradiated with actinic rays after the support is removed.

As an exposure method, a method of using actinic rays projecting a reticle image and irradiating the image-like shape through a lens (projection exposure method) is used. That is, the photosensitive resin composition of this embodiment can be applied to a method (projection exposure method) in which an actinic ray projecting a reticle image is irradiated into an image shape through a lens. From the viewpoint of improving productivity, the projection exposure method may be used alone or in combination with an exposure method other than the projection exposure method. Examples of the exposure method that can be used in combination include a method of irradiating actinic rays into an image form through a negative mask pattern called "artwork" (mask exposure method), and direct exposure by laser. Imaging (Laser Direct Imaging, LDI) exposure method, etc., a method of directly drawing an exposure method and irradiating actinic rays into an image.

The light source for actinic rays is not particularly limited if it is a commonly known light source. For example, gas lasers such as carbon arc lamps, mercury vapor arc lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, xenon lamps, and argon lasers can be used. , Yttrium-Aluminum-Garnet Laser (YAG laser) and other solid-state lasers, gallium nitride-based blue-violet lasers and other semiconductor lasers and other light sources that effectively emit ultraviolet light. Furthermore, a light source that efficiently emits visible light such as a floodlight for photography or a fluorescent lamp can also be used. Among these, from the viewpoint of improving the balance between resolution and alignment, a light source capable of emitting i-ray monochromatic light with an exposure wavelength of 365 nm and an h-ray monochromatic with an exposure wavelength of 405 nm can be used A light source of light or a source of actinic rays that can emit ihg mixed rays at an exposure wavelength can be used, wherein a light source of i-ray monochromatic light with an exposure wavelength of 365 nm can be used. As a light source capable of radiating i-ray monochromatic light with a wavelength of 365 nm, for example, an ultra-high pressure mercury lamp can be cited.

(Iii) Development step In the development step, the unexposed portion (uncured portion) of the photosensitive resin layer is removed from the substrate by development. Through the development step, a resist pattern including a photo-hardened portion formed by photo-curing the photosensitive resin layer is formed on the substrate. When a support exists on the photosensitive resin layer, after removing the support, the unexposed part other than the exposed part is removed by development. The development methods include wet development and dry development.

In the case of wet development, a developer corresponding to the photosensitive resin composition can be used for development by a known wet development method. Examples of the wet development method include a dipping method, a coating method, a high-pressure spray method, brushing, tapping, blade coating, and oscillating immersion. From the viewpoint of improving self-resolution, a high-pressure spray method may be used. These wet development methods can be used alone or in combination of two or more methods.

The developer can be appropriately selected according to the structure of the photosensitive resin composition. For example, an alkaline aqueous solution, an organic solvent developer, etc. are mentioned.

From the standpoint of safety, stability, and better operability, an alkaline aqueous solution can be used as the developer. As the base of the alkaline aqueous solution, for example, alkali metal hydroxides such as hydroxides of lithium, sodium, or potassium, alkali metal carbonates such as carbonates or bicarbonates of lithium, sodium, potassium, or ammonium, potassium phosphate, and phosphoric acid can be used. Alkali metal phosphates such as sodium, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate, borax (sodium tetraborate), sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine , 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diamino-2-propanol, morpholine, etc.

As the alkaline aqueous solution used in the development, a dilute solution of 0.1 to 5 mass% sodium carbonate, a dilute solution of 0.1 to 5 mass% potassium carbonate, and a dilute solution of 0.1 to 5 mass% sodium hydroxide Dilute solution, 0.1% to 5% by mass of sodium tetraborate dilute solution, etc. In addition, the pH of the alkaline aqueous solution used for development may be in the range of 9 to 11, and the temperature of the alkaline aqueous solution may be adjusted according to the developability of the photosensitive resin layer. Furthermore, in an alkaline aqueous solution, for example, a surfactant, a defoamer, a small amount of organic solvent for promoting development, etc. may be mixed.

Examples of the organic solvent used in the organic solvent developer include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, and methyl. Isobutyl ketone, γ-butyrolactone, 3-acetone alcohol, acetone, ethyl acetate, alkoxy ethanol having a C 1-4 alkoxy group, ethanol, isopropanol, butanol, diethylene glycol Alcohol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, etc. From the viewpoint of preventing fire, these organic solvents can be added with water in the range of 1% by mass to 20% by mass to prepare an organic solvent developer.

In the method for forming a resist pattern of the present embodiment, after removing the unexposed portion in the development step, it may also be necessary to include heating by 60° C. to 250° C. or 0.2 J/cm ² to 10 J/cm Step ² : Exposure of the exposure amount to further harden the resist pattern.

<Manufacturing method of printed circuit board> The manufacturing method of the printed circuit board of this embodiment includes etching or plating the substrate formed with the resist pattern by the method of forming the resist pattern to form a conductor The patterning step may also include other steps such as a resist pattern removing step, if necessary. The method for manufacturing a printed circuit board of the present embodiment uses the method for forming a resist pattern using the photosensitive resin composition, whereby it can be suitably used in the formation of a conductor pattern, and it is more suitably applied to In the method of forming a conductor pattern by plating process.

In the etching process, the resist pattern formed on the substrate including the conductor layer is used as a mask, and the conductor layer of the substrate not covered by the resist pattern is etched away to form a conductor pattern.

The etching treatment method can be appropriately selected according to the conductor layer to be removed. Examples of the etching solution include copper chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide-based etching solution. From the viewpoint of good etching factor, an iron chloride solution can be used.

On the other hand, in the plating process, the resist pattern formed on the substrate including the conductor layer is used as a mask, and copper, solder, or the like is plated on the conductor layer of the substrate not covered by the resist pattern. After the plating process, the resist pattern is removed by removing the resist pattern described later, and the conductor layer covered with the resist pattern is further etched to form a conductor pattern.

As a method of plating treatment, it may be electroplating treatment or electroless plating treatment, and it may be electroless plating treatment from the standpoint of further improving the yield. Examples of electroless plating include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as highly dispersed solder plating, Watt bath (nickel sulfate-nickel chloride) plating, and nickel sulfamate Nickel plating, hard gold plating, soft gold plating, etc.

After the etching process or the plating process, the resist pattern on the substrate is removed. The removal of the resist pattern can be peeled off by, for example, an aqueous solution that is more alkaline than the alkaline aqueous solution used in the development step. As the strong alkaline aqueous solution, for example, a 1% by mass to 10% by mass sodium hydroxide aqueous solution, a 1% by mass to 10% by mass potassium hydroxide aqueous solution, or the like can be used. Among these, from the standpoint of further improving the releasability, a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution of 1% by mass to 5% by mass can be used.

Examples of the peeling method of the resist pattern include a dipping method and a spraying method. These may be used alone or in combination.

When the resist pattern is removed after performing the plating process, the conductive layer covered with the resist pattern is further etched by an etching process to form a conductive pattern, whereby a desired printed circuit board can be manufactured. The etching treatment method at this time can be appropriately selected according to the conductor layer to be removed. For example, the etching solution can be applied.

The manufacturing method of the printed circuit board of this embodiment can be applied not only to the manufacture of a single-layer printed circuit board, but also to the manufacture of a multilayer printed circuit board, and can also be applied to a printed circuit having a small-diameter through hole In the manufacture of boards, etc.

The method of manufacturing a printed circuit board of the present embodiment can be suitably used in the manufacturing of high-density package substrates, particularly the manufacturing of wiring boards by the semi-additive method. In addition, an example of the manufacturing process of the wiring board by the semi-additive method is shown in FIGS. 2(a) to 2(f).

In FIG. 2( a ), a substrate (substrate for circuit formation) in which the conductor layer 40 is formed on the insulating layer 50 is prepared. The conductor layer 40 is, for example, a copper layer. In FIG. 2( b ), the photosensitive resin layer 30 is formed on the conductor layer 40 of the substrate by the photosensitive resin layer forming step. In FIG. 2( c ), in the exposure step, actinic rays 80 projecting a reticle image are irradiated on the photosensitive resin layer 30 to form a photo-hardened portion on the photosensitive resin layer 30. In FIG. 2(d), in the development step, the regions other than the photo-hardened portion formed by the exposure step are removed from the substrate, thereby forming the resist pattern 32 as the photo-hardened portion on the substrate . In FIG. 2( e ), a plating layer 60 is formed on the conductor layer 40 of the substrate not covered by the resist pattern by a plating process using the resist pattern 32 as a mask. In FIG. 2(f), after the resist pattern 32 is peeled off with a strong alkali aqueous solution, the conductive layer 40 masked by the resist pattern 32 is removed by flash etching to form The conductor pattern 70 of the plating layer 62 and the conductor layer 42 after the etching process. The material of the conductor layer 40 and the plating layer 60 may be the same or different. When the conductor layer 40 and the plating layer 60 are the same material, the conductor layer 40 and the plating layer 60 may be integrated. In addition, the projection exposure method has been described in FIGS. 2( a) to 2 (f ). However, the resist pattern 32 may be formed by using the mask exposure method and the direct drawing exposure method together.

In the above, the present embodiment has been described, but the present disclosure is not limited to the above-mentioned embodiment. [Example]

Hereinafter, the purpose and advantages of the present disclosure will be described more specifically based on the embodiments, but the present disclosure is not limited to the following embodiments. That is, it should be construed that the specific materials listed in these embodiments and their amounts, as well as other conditions and details, do not improperly limit the present disclosure. In addition, unless otherwise specified, "parts" and "%" are quality standards.

[Examples 1 to 9 and Comparative Examples 1 to 7] First, according to Synthesis Example 1, the binder polymer (A-1) shown in Table 1 and Table 2 below was synthesized.

<Synthesis Example 1> 125 g of methacrylic acid, 25 g of methyl methacrylate, 125 g of benzyl methacrylate, and 225 g of styrene were mixed with 1.5 g of azobisisobutyronitrile as a polymerizable monomer. Prepare solution a.

Furthermore, a solution b was prepared by dissolving 1.2 g of azobisisobutyronitrile in a mixed solution (mass ratio of 3:2) of 100 g of 60 g methyl cellosolve and 40 g of toluene.

On the other hand, in a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen introduction tube, add 400 g of a mixed solution of methyl cellosolve and toluene with a mass ratio of 3:2 (hereinafter also referred to as "Mixed solution x"), stirring while blowing nitrogen gas, and heating to 80°C.

In the mixed solution x in the flask, the solution a was added dropwise for 4 hours with the drop acceleration fixed, and then stirred at 80° C. for 2 hours. Next, in the solution in the flask, the solution b was added dropwise at a fixed acceleration rate for 10 minutes, and then the solution in the flask was stirred at 80° C. for 3 hours. The solution in the flask was further heated to 90° C. for 30 minutes, and kept at 90° C. for 2 hours, and then cooled to room temperature to obtain a solution of the binder polymer (A-1). The mixed solution x was added to the solution of the binder polymer (A-1) to prepare the non-volatile component (solid content) to be 50% by mass.

The weight average molecular weight of the binder polymer (A-1) is 50,000, and the acid value is 163 mgKOH/g. In addition, the acid value was measured by the neutralization titration method. Specifically, it can be measured by adding 30 g of acetone to a solution of 1 g of a binder polymer and further uniformly dissolving it, and then adding an appropriate amount of phenolphthalein as an indicator to the binder polymer The solution was titrated with 0.1 N KOH aqueous solution. The weight average molecular weight is measured by gel permeation chromatography, and is derived by conversion using a calibration curve of standard polystyrene. The conditions of GPC are as follows.

GPC condition pump: Hitachi L-6000 (manufactured by Hitachi, Ltd.) Tubing: a total of 3 of the following (tubing specifications: 10.7 mmφ×300 mm, all manufactured by Hitachi Chemical Co., Ltd.) Gelpack GL-R420 Gelpack GL-R430 Gelpack GL-R440 Dissolution solution: Tetrahydrofuran Sample concentration: Collect 120 mg of a binder polymer with a solid content of 50% by mass, and dissolve it in 5 mL of tetrahydrofuran to prepare a sample. Measurement temperature: 25°C Flow rate: 2.05 mL/min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd., product name)

<Preparation of photosensitive resin composition> Next, by mixing the components shown in the following Table 1 and Table 2 in the amounts (units: parts by mass) shown in the same table, Examples 1 to 4 were obtained. The photosensitive resin compositions of Example 9 and Comparative Examples 1 to 7. In addition, the formulation amounts of (A) component and (B) component in Table 1 and Table 2 are all formulation amounts based on solid content. In any of the examples and comparative examples, the total content of the polymerization inhibitors (methoxyphenol, etc.) contained in the component (B) is the total solid content of the component (A) and the component (B) As a benchmark (100% by mass), less than 0.01% by mass.

[Table 1]

[Table 2]

The details of each component in Table 1 and Table 2 are as follows. (A) Ingredient: Adhesive polymer*1: Adhesive polymer (A-1) Methacrylic acid/methyl methacrylate/benzyl methacrylate/styrene=25/5/25/45 (mass ratio ), weight average molecular weight = 50,000, solid content = 50% by mass, methyl cellosolve/toluene = 3/2 (mass ratio) solution

(B) Component: Photopolymerizable compound having an ethylenic unsaturated bond *2: FA-024M (manufactured by Hitachi Chemical Co., Ltd., product name) Polyolefin glycol dimethacrylate (EO group: 6 (average value ), PO group: 12 (average)) *3: FA-321M (manufactured by Hitachi Chemical Co., Ltd., product name) 2,2-bis(4-(methacryloxypentaethoxy)phenyl ) Propane*4: BPE-200 (manufactured by Shin Nakamura Chemical Industry Co., Ltd., product name) 2,2-bis(4-(methacryloxydiethoxy)phenyl)propane*5: BP- 2EM (manufactured by Kyoeisha Chemical Co., Ltd., product name) 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane (EO group: 2.6 (average))

(C) Ingredient: Photopolymerization initiator *6: B-CIM (manufactured by Hodogaya Chemical Industry Co., Ltd., product name) 2,2'-bis(2-chlorophenyl)-4,4',5, 5'-Tetraphenylbisimidazole

(D) Ingredient: Light sensitizer *7: Pyrazoline compound (manufactured by Hodogaya Chemical Industry Co., Ltd., chemical name: 1-phenyl-3-(4-methoxystyryl)-5- (4-methoxyphenyl)pyrazoline) *8: EAB (manufactured by Hodogaya Chemical Industry Co., Ltd., product name) 4,4'-bis(diethylamino)benzophenone

(E) Ingredient: Polymerization inhibitor *9: TBC (made by DIC) Co., Ltd. 4-Third-butyl catechol

<Preparation of photosensitive element> The obtained photosensitive resin compositions of Examples 1 to 9 and Comparative Examples 1 to 7 were uniformly applied to polyethylene terephthalate with a thickness of 16 μm, respectively. The diester film (manufactured by Toray Co., Ltd., product name "FB40") (support) was dried with a hot air convection dryer at 100°C for 10 minutes to form a photosensitive film with a thickness of 10 μm after drying Sexual resin layer.

A polypropylene film (protective layer) (manufactured by TAMAPOLY Co., Ltd., product name "NF-15") was laminated on the photosensitive resin layer to obtain a layered support, a photosensitive resin layer, The photosensitive element of the protective layer.

<Preparation of laminate> A copper-clad laminate with a glass epoxy material having a copper foil with a thickness of 12 μm in two areas layered using a grinder (made by Sanqi Co., Ltd.) with a brush equivalent to #600 (Substrate, Hitachi Chemical Co., Ltd., product name "MCL-E-67") The copper surface is polished, washed with water and dried under air flow. After heating the polished copper-clad laminate to 80°C, the protective layer is peeled off, and the photosensitive elements obtained above are laminated on the copper-clad in such a way that the photosensitive resin layer is in contact with the copper surface Laminate. Using a heated roller at 110° C., under a crimping pressure of 0.40 MPa, lamination was performed at a roller speed of 1.5 m/min.

As described above, a layered product in which a copper-clad laminate, a photosensitive resin layer, and a support are sequentially stacked is obtained. The obtained laminate was used as a test piece in the test shown below.

<Evaluation> (Evaluation of light sensitivity) Divide the obtained test piece into three areas, place a concentration area of 0.00 to 2.00, a concentration step of 0.05, and a plate size of 20 mm×187 on one of the supports mm, the size of each step is 3 mm × 12 mm Hitachi 41-step ladder plate. The exposure is a projection exposure device (product made by Ushio Motor Co., Ltd., product name "UX-2240SMXJ-01") using a semiconductor laser with a wavelength of 365 nm as the light source, with an energy of 100 mJ/cm ² (exposure Amount) to expose the photosensitive resin layer. At this time, other unused areas are covered with black sheets. In addition, for different areas, exposure is performed with the energy of 150 mJ/cm ² and 200 mJ/cm ² by the same method. In addition, for the measurement of illuminance, an ultraviolet illuminance meter (manufactured by Niuwei Electric Co., Ltd., product name "UIT-250") using a probe corresponding to 365 nm, and an optical receiver (manufactured by Niuwei Electric Co., Ltd., product name "UVD- S365").

Next, the support was peeled off from the test piece, and the photosensitive resin layer was spray-developed at twice the shortest development time (the shortest time to remove the unexposed portion) using a 1.0% by mass sodium carbonate aqueous solution at 30°C to remove the unexposed portion. It is removed and developed. In addition, the minimum development time can be determined by measuring the time for completely removing the photosensitive resin layer in the unexposed portion by the development process.

After the development treatment, the number of remaining steps (step number) of the ladder-shaped plate of the photo-hardened material (resist pattern) formed on the copper-clad laminate at each exposure was measured. Next, a calibration curve of the exposure amount and the step number is prepared, and the exposure amount (unit: mJ/cm ² ) with the step number of 11 steps is obtained, and this is used as the light sensitivity of the photosensitive resin composition. The smaller the exposure amount, the better the light sensitivity. The results are shown in Table 3 and Table 4.

(Evaluation of resolution) On the support of the obtained test piece, a line width/gap width of z/z (z=1 to 30 (change at intervals of 1 μm)) (unit: μm) was placed The wiring pattern is used as a glass mask for the resolution evaluation pattern, and a projection exposure device (manufactured by Niuwei Electric Co., Ltd., product name "UX-2240SMXJ-01") using a semiconductor laser with a wavelength of 365 nm as a light source is used. After the development of the 41-step ladder-type plate, the number of remaining step steps becomes 11 steps, and the photosensitive resin layer is exposed. After exposure, the same development process as the above-mentioned photosensitivity evaluation was performed.

After the development process, the resist pattern was observed using an optical microscope. The minimum value (minimum gap width, unit: μm) among the gap widths between the line portions (exposed parts) where the unexposed portions were completely removed by the development process was used as an index for resolution evaluation. The smaller the value, the better the resolution. The results are shown in Table 3 and Table 4.

(Evaluation of Aspect Ratio) With respect to the smallest line portion of the width of the resist pattern formed in the evaluation of the resolution, the height from the surface of the copper-clad laminate (hereinafter referred to as "line height") was measured. This line height (unit: μm) is divided by the minimum line width (unit: μm) of the resist pattern in which the unexposed portion is completely removed in the evaluation of the resolution (it can be said that it is the smallest in the evaluation of the resolution The value of the gap width is the same), calculate the aspect ratio (line height/minimum line width). The results are shown in Table 3 and Table 4.

[table 3]

[Table 4]

As can be seen from the results shown in Tables 3 and 4, the content of the polymerization inhibitor used can be confirmed to be 0.03 parts by mass to 0.3 parts by mass relative to 100 parts by mass of the total solid content of the components (A) and (B). Compared to Comparative Examples 1 to 7, the resist pattern formed by the photosensitive resin composition of Example 1 to Example 9 is superior in resolution and high in aspect ratio. In addition, the photosensitive resin compositions of Examples 1 to 9 have a higher exposure than the photosensitive resin compositions of Comparative Examples 1 to 7. Although the sensitivity is reduced, the reduction in sensitivity is not necessarily a disadvantage. The characteristics can be said to be an appropriate light sensitivity range that meets the market requirements in the fields of semiconductor packaging and the like. Furthermore, in fields such as semiconductor packaging where resolution is particularly important, it is strongly required that even if the resolution is reduced by 1 μm unit, the resolution will be good. Therefore, the resolution from 6 μm to 7 μm (comparative example) becomes good The effect of 4 μm to 5 μm (Example) can be said to be a great effect.

Furthermore, according to the comparison of Examples 1 to 7 and 9 using a pyrazoline compound as a photosensitizer, and Example 8 using EAB as a photosensitizer, it can be confirmed that the content of the polymerization inhibitor relative to (A) The total solid content of the component and (B) component is 0.03 parts by mass to 0.3 parts by mass for 100 parts by mass of the photosensitive resin composition of Examples 1 to 9, regardless of the type of the photosensitizer , A resist pattern with excellent resolution and improved aspect ratio can be obtained. [Industry availability]

As described above, the present disclosure can provide a photosensitive resin composition that can form a resist pattern with excellent resolution and a high aspect ratio when a resist pattern is formed using a projection exposure method, and use A photosensitive element, a resist pattern forming method and a printed circuit board manufacturing method therefor.

1‧‧‧Photosensitive element 2‧‧‧Support 3. 30‧‧‧ photosensitive resin layer 4‧‧‧Protection layer 32‧‧‧resist pattern 40‧‧‧Conductor layer 42‧‧‧Conductor layer after etching 50‧‧‧Insulation 60‧‧‧plating layer 62‧‧‧ Plating after etching 70‧‧‧Conductor pattern 80‧‧‧actinic rays

FIG. 1 is a schematic cross-sectional view showing an embodiment of the photosensitive element of the present disclosure. FIGS. 2( a) to 2 (f) are diagrams schematically showing an example of manufacturing steps of a printed circuit board using a semi-additive method.

Claims (5)

A photosensitive resin composition comprising (A) a binder polymer, (B) a photopolymerizable compound having an ethylenically unsaturated bond, (C) a photopolymerization initiator, (D) a photosensitizer, and (E) A polymerization inhibitor, the content of the (E) polymerization inhibitor relative to the total solid content of the (A) binder polymer and the (B) photopolymerizable compound having an ethylenically unsaturated bond 100 parts by mass is 0.05 parts by mass to 0.15 parts by mass, wherein the (E) polymerization inhibitor contains a compound represented by the following general formula (I):

[Wherein, R ⁵ represents a halogen atom, a hydrogen atom, a C 1-20 alkyl group, a C 3-10 cycloalkyl group, an amine group, an aryl group, a mercapto group, a C 1-10 alkyl mercapto group, Carboxyalkyl having 1 to 10 carbon atoms, alkoxy or heterocyclic group having 1 to 20 carbon atoms, m represents an integer of 2 or more selected so that m+n becomes 6 or less, and n represents M+n is an integer of 0 or more selected so as to be 6 or less. When n is an integer of 2 or more, R ⁵ may be the same or different from each other]. The photosensitive resin composition as described in item 1 of the patent application scope, wherein the content of the (D) light sensitizer relative to the (A) binder polymer and The total solid content of the (B) photopolymerizable compound having an ethylenically unsaturated bond is 100 parts by mass or less for 100 parts by mass. A photosensitive element comprising: a support; and a photosensitive resin layer formed on the support using the photosensitive resin composition as described in claim 1 or 2 on. A method for forming a resist pattern, comprising: using a photosensitive resin composition as described in item 1 or 2 of the patent application or a photosensitive element as described in item 3 of the patent application on a substrate A step of forming a photosensitive resin layer; a step of exposing the photosensitive resin layer through a lens using actinic rays projecting a reticle image; and developing an unexposed portion of the photosensitive resin layer from the substrate by development Steps of removal. A method for manufacturing a printed circuit board, comprising: etching or plating a substrate formed with a resist pattern by the method for forming a resist pattern as described in item 4 of the patent application scope to form a conductor Patterned steps.

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