JP5814667B2 - Photosensitive element - Google Patents

Description

  The present invention relates to a photosensitive element and the like.

  For electronic devices such as personal computers or mobile phones, printed wiring boards and the like are used for mounting components or semiconductors. As a resist for manufacturing printed wiring boards and the like, conventionally, a photosensitive element formed by laminating a photosensitive resin layer on a support film and further laminating a protective film on the photosensitive resin layer as necessary, so-called a photosensitive element. A dry film resist (hereinafter sometimes referred to as “DF”) is used.

  As the photosensitive resin layer used here, an alkali developing type using a weak alkaline aqueous solution as a developing solution is generally used. In order to produce a printed wiring board or the like using DF, if there is a protective film, first peel off the protective film, and then attach a laminator or the like on a permanent circuit production substrate such as a copper-clad laminate or a flexible substrate. Use DF to laminate and expose through a wiring pattern mask film or the like. Next, if necessary, the support film is peeled off, and the photosensitive resin layer of the unexposed part is dissolved or dispersed and removed by a developer, and a cured resist pattern (hereinafter simply referred to as “resist pattern”) is formed on the substrate. May be formed).

  After forming the resist pattern, the process of forming a circuit is roughly divided into two methods. The first method is a method (etching method) in which after removing a copper surface such as a copper clad laminate not covered with a resist pattern by etching, the resist pattern portion is removed with an alkaline aqueous solution stronger than the developer. In the second method, the copper surface similar to the first method is plated with copper, solder, nickel, tin, etc., and then the resist pattern portion is removed in the same manner, and the copper-clad laminate that appears This is a method of etching the copper surface (plating method). For the etching, cupric chloride, ferric chloride, a copper ammonia complex solution or the like is used.

  In recent years, DF has been used not only to form printed wiring boards, but also to form flexible and high-density wiring such as tape automated bonding (TAB) or chip-on-film (COF), or ultra-high-density wiring such as semiconductor package substrates. Are also being used. Naturally, a high-resolution DF is required to realize high-density wiring.

  And as an attempt to improve the resolution, Patent Document 1 discloses a support film including a resin layer containing fine particles formed on one surface of a biaxially oriented polyester film, and a resin layer containing the fine particles of the support film. A technique is described in which a photosensitive resin layer is laminated on a surface opposite to the surface on which is formed.

  Patent Document 2 describes a technique in which an intermediate layer is provided between a support film and a photosensitive resin layer, and the support film is peeled off and exposed from above the intermediate layer.

Patent No. 4014872 JP 2008-175957 A

  However, when forming a high-density wiring, it is important to reduce the backlash of the resist sidewall, and the techniques described in Patent Documents 1 and 2 are all improved from this point of view. There was room for it.

  Accordingly, it is an object of the present invention to provide a photosensitive element that can reduce backlash of a sidewall of a resist pattern, and to provide a method for forming a resist pattern and a method for forming a conductor pattern using the photosensitive element. To do.

As a result of intensive studies and experiments to solve the above problems, the present inventor has found that the above problems can be solved by the following technical means, and has completed the present invention.
That is, the present invention is as follows.

  [1] It has a laminated structure in which a support film, an intermediate layer, and a photosensitive resin layer are sequentially laminated, and the support film contains fine particles on the side opposite to the surface on which the intermediate layer is laminated. A photosensitive element, comprising a biaxially oriented polyester film including a resin layer, wherein the intermediate layer is a water-soluble resin layer.

  [2] The photosensitive element according to [1], wherein the water-soluble resin layer contains polyvinyl alcohol.

  [3] The photosensitive element according to [1] or [2], wherein the water-soluble resin layer includes 50% by mass to 100% by mass of polyvinyl alcohol based on the mass of the water-soluble resin layer.

  [4] The photosensitive element according to any one of [1] to [3], wherein the water-soluble resin layer has a thickness of 1 μm to 8 μm.

｛式中、Ｒ_１及びＲ_２は、水素原子又は炭素数１〜１０のアルキル基であり、そしてＡは、−ＣＨ_２ＣＨ_２Ｏ−ユニット及び／又は−ＣＨ_２ＣＨ（ＣＨ_３）Ｏ−ユニットを含む１種又は２種以上の単独又は繰り返し構造を表す。｝
で表される化合物を含む、［１］〜［４］のいずれか１項に記載の感光性エレメント。 [5] The water-soluble resin layer has the following general formula (I):

{Wherein R ₁ and R ₂ are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and A is a —CH ₂ CH ₂ O— unit and / or —CH ₂ CH (CH ₃ ) O—. 1 type or 2 types or more of a unit is included, or a repeating structure is represented. }
The photosensitive element of any one of [1]-[4] containing the compound represented by these.

  [6] The photosensitive element according to any one of [1] to [5] is laminated on the surface of the metal plate or the metal-coated insulator, the support film is peeled off, exposed to ultraviolet rays, and then developed. A method for forming a resist pattern, including a step of removing an unexposed portion by the step.

  [7] A conductor pattern manufacturing method including a step of etching or plating a substrate on which a resist pattern is formed by the method according to [6].

  According to the present invention, it is possible to provide a photosensitive element that can reduce backlash of a sidewall of a resist pattern, and to provide a method for forming a resist pattern and a method for forming a conductor pattern using the photosensitive element.

  Hereinafter, the best mode for carrying out the present invention (hereinafter abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

<Photosensitive element (photosensitive resin laminate)>
The photosensitive element of the present embodiment has a laminated structure in which a support film, an intermediate layer, and a photosensitive resin layer are sequentially laminated, and the support film is opposite to the surface on which the intermediate layer is laminated. A biaxially oriented polyester film including a resin layer containing fine particles on the side, and the intermediate layer is a water-soluble resin layer.
By laminating a fine particle-containing resin layer on one surface of a biaxially oriented polyester film, and laminating a water-soluble resin layer on the surface opposite to the surface on which the fine particle-containing resin layer of the biaxially oriented polyester film is laminated, It can be presumed that the backlash of the resist pattern sidewall can be reduced because light scattering by fine particles in the vicinity of the photosensitive resin layer can be avoided and the exposure mask can be irradiated with light more faithfully. it can.

<Support film>
In this embodiment, the support film is made of a biaxially oriented polyester film, and the fine particle-containing resin layer is laminated only on one surface of the biaxially oriented polyester film.

  In the present embodiment, the fine particle-containing resin layer is a resin layer containing fine particles. In the present embodiment, the fine particles are very fine particles. The average particle size of the fine particles is preferably 0.01 μm to 5.0 μm, more preferably 0.02 μm to 4.0 μm, and particularly preferably 0.03 μm to 3.0 μm. Setting the average particle size to 0.01 μm or more is preferable from the viewpoint of improving workability, and setting the average particle size to 5.0 μm or less is preferable from the viewpoint of improving resolution and sensitivity.

  Examples of the fine particles include inorganic particles such as silica, kaolin, talc, alumina, calcium phosphate, titanium dioxide, calcium carbonate, barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, or crosslinked polymer particles, Shu Organic particles such as calcium acid can be used, and silica particles are preferable from the viewpoint of transparency. These may be used alone or in combination of two or more.

  Examples of the base resin constituting the fine particle-containing resin layer include polyester resins, polyurethane resins, acrylic resins, mixtures thereof, and copolymers thereof.

  The thickness of the fine particle-containing resin layer is preferably 0.01 μm to 5.0 μm, more preferably 0.05 μm to 3.0 μm, particularly preferably 0.1 μm to 2.0 μm, 0 It is very preferable that it is 1 μm to 1.0 μm. Setting the thickness to 0.01 μm or more is preferable from the viewpoint of preferably exhibiting the effects of the present invention, while setting the thickness to 5.0 μm or less means transparency, sensitivity, and resolution of the biaxially oriented polyester film. From the viewpoint of improving the ratio.

  The method for laminating the resin layer on one surface of the biaxially oriented polyester film is not limited, and examples thereof include coating.

  Generally, a biaxially oriented polyester film refers to a polyester film that includes a portion in which structural units are oriented in a biaxial direction. Examples of the polyester resin constituting the biaxially oriented polyester film include, for example, aromatic linear polyesters and aliphatic dicarboxylics composed of aromatic dicarboxylic acids such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate and diols. Examples thereof include aliphatic linear polyesters composed of acids and diols, and polyester resins mainly composed of polyesters such as copolymers thereof. These resins are used alone or in combination of two or more.

  The biaxially oriented polyester film may contain fine particles. Examples of the fine particles include the same fine particles as those contained in the fine particle-containing resin layer. The content of fine particles in the biaxially oriented polyester film is preferably 0.01 to 80 ppm, more preferably 0.01 to 60 ppm, and particularly preferably 0.01 to 40 ppm. From the viewpoint of production efficiency, it is preferably 0.01 ppm or more, and from the viewpoint of transparency, resolution, and sensitivity of the entire polyester film, it is preferably 80 ppm or less.

  Although it does not limit as a manufacturing method of a biaxially-oriented polyester film, For example, a biaxial stretching method etc. can be used. Moreover, after forming a fine particle-containing resin layer on one surface of an unstretched film or a uniaxially stretched film, the support film may be further stretched. The thickness of the biaxially oriented polyester film is preferably 1 μm to 100 μm, more preferably 1 μm to 50 μm, particularly preferably 1 μm to 30 μm, and extremely preferably 10 μm to 30 μm. If the thickness is 1 μm or more, manufacturability and availability are easy to improve, while if the thickness is 100 μm or less, the inexpensiveness is easy to improve.

  Examples of the support film that can be obtained include, but are not limited to, A-1517, A2100-16, and A4100-25 manufactured by Toyobo Co., Ltd.

  The thickness of the support film is preferably 1 to 100 μm, more preferably 1 to 50 μm, particularly preferably 1 to 30 μm, and extremely preferably 10 to 30 μm. Setting this thickness to 1 μm or more is preferable from the viewpoint of improving mechanical strength and making it difficult to break the polymer film at the time of coating, while setting this thickness to 100 μm or less improves resolution, and This is preferable from the viewpoint of lowering the price of the photosensitive element.

<Water-soluble resin layer>
In this embodiment, the water-soluble resin layer is laminated on the other surface of the biaxially oriented polyester film in the support film (that is, the surface on which the fine particle-containing resin layer is not formed), and the support film and the photosensitivity. It plays a role as an intermediate layer between the resin layers. Since this water-soluble resin layer is subjected to alkali development, it may be an arbitrary layer containing a water-soluble resin.

  In the radical polymerization reaction, radicals are killed by contact with oxygen and the reaction is difficult to proceed. Therefore, when the support film is peeled off and exposure is performed, it is preferable to use an oxygen barrier polyvinyl alcohol as an intermediate layer. . Generally, polyvinyl alcohol is produced by alkali saponifying polyvinyl acetate. The average degree of polymerization of polyvinyl alcohol is, for example, 100 to 10,000, and preferably 300 to 5,000 from the viewpoint of oxygen barrier properties and developability. The saponification degree of polyvinyl alcohol is preferably 50 mol% or more, more preferably 70 mol% or more, and further preferably 80 mol% or more from the viewpoint of developability. As polyvinyl alcohol having such an average degree of polymerization and / or saponification degree, Kuraray Co., Ltd. PVA-120, Kuraray Co., Ltd. PVA-203, Kuraray Co., Ltd. PVA-205, Kuraray Co., Ltd. PVA-220, Kuraray PVA-235, Kuraray PVA-403, Kuraray PVA-405, etc. are mentioned. In addition, as these polyvinyl alcohol, it can use individually by 1 type or can use 2 or more types together.

  From the viewpoints of developability and oxygen barrier properties, the blending ratio of polyvinyl alcohol (the total amount when plural types are used in combination) in the water-soluble resin layer is preferably 50% by mass to 100% by mass, more preferably. It is 70 mass%-100 mass%, More preferably, it is 90 mass%-100 mass%.

  From the viewpoint of developability, the thickness of the water-soluble resin layer is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less. Further, the thickness of the water-soluble resin layer is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 1 μm or more, and particularly preferably 3 μm or more from the viewpoint of the stability of the water-soluble resin layer after peeling the support film. Most preferable is 5 μm or more. For example, in the present embodiment, the thickness of the water-soluble resin layer is preferably 1 μm to 8 μm.

  From the viewpoint of peelability from the support film, developability, and cost, the water-soluble resin layer can contain other water-soluble polymer or plasticizer in addition to at least one kind of polyvinyl alcohol as described above. Other water-soluble polymers or plasticizers may be used alone or in combination of two or more.

  Examples of such “other water-soluble polymer or plasticizer” include polyvinyl alcohol or polyvinyl pyrrolidone selected from the group consisting of polyvinyl alcohol copolymerized with 1 to 20 mol% of olefin, and derivatives thereof, hydroxyethyl cellulose and the like. Examples thereof include water-soluble cellulose derivatives, polyalkylene oxides, polyalkylene oxide ester compounds, polyalkylene oxides such as polyalkylene oxide ether compounds and derivatives thereof, and phthalic acid esters such as dibutyl phthalate. Further, vinyl ether-maleic anhydride copolymer and water-soluble salts thereof, vinyl ether-maleic anhydride copolymer and water-soluble salts thereof, carboxyalkyl starch water-soluble salts, polyacrylamide, polyamide, water-soluble salts of polyacrylic acid, gelatin Etc. In a preferred embodiment, the water-soluble resin layer contains a polyalkylene oxide derivative as a plasticizer.

｛式中、Ｒ_１及びＲ_２は、水素原子又は炭素数１〜１０のアルキル基であり、そしてＡは、−ＣＨ_２ＣＨ_２Ｏ−ユニット及び／又は−ＣＨ_２ＣＨ（ＣＨ_３）Ｏ−ユニットを含む１種又は２種以上の単独又は繰り返し構造を表す。｝
で示される化合物が好ましい。 The polyalkylene oxide derivative has the following general formula (I):

{Wherein R ₁ and R ₂ are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and A is a —CH ₂ CH ₂ O— unit and / or —CH ₂ CH (CH ₃ ) O—. 1 type or 2 types or more of a unit is included, or a repeating structure is represented. }
The compound shown by these is preferable.

｛式中、Ｒ_１及びＲ_２は、水素原子又は炭素数１〜１０のアルキル基であり、ｎ１は、１〜３０の整数であり、そしてｎ２は、０〜３０の整数である。｝
で示される化合物が特に好ましい。 Moreover, as a polyalkylene oxide derivative, the following general formula (II):

{Wherein, _{R 1} and _{R 2} is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, n1 is an integer from 1 to 30, and n2 is an integer of 0 to 30. }
The compound shown by is especially preferable.

  Specific examples of the polyalkylene oxide derivative represented by the above general formula (I) include PEG # 2000 manufactured by NOF Corporation, UNIOX M-550 manufactured by NOF Corporation, Neoscore manufactured by Toho Chemical Industry Co., Ltd. 2326, Adeka Pluronic L-61 manufactured by ADEKA Corporation, Adeka Pluronic L-44 manufactured by ADEKA Corporation, Adekapol DL-150 manufactured by ADEKA Corporation, and the like.

In the general formulas (I) and (II), the arrangement of the repeating units of CH ₂ CH ₂ O and CH ₂ CH (CH ₃ ) O may be random or block. When R ₁ and R ₂ are both hydrogen atoms, a diol body (EO and PO-modified diol) is obtained, and when R ₁ is a hydrogen atom and R ₂ is an alkyl group, a monoether body (EO and PO). PO-modified monoether), and when R ₁ and R ₂ are both alkyl groups, they are diethers (EO and PO-modified diether).

In the general formula (II), in order to improve the alkali solubility of the polyalkylene oxide derivative and the compatibility with the polyvinyl alcohol, R ₁ and R ₂ may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. A hydrogen atom or an alkyl group having 1 to 8 carbon atoms is more preferable, and a hydrogen atom or an alkyl group having 1 to 4 carbon atoms is more preferable.

  In the general formula (II), n1 + n2 is preferably 3 or more from the viewpoint of odor, and preferably 60 or less from the viewpoint of compatibility with polyvinyl alcohol and developability. n1 + n2 is more preferably 5 or more and 55 or less, and further preferably 7 or more and 50 or less.

  The copolymer of ethylene oxide and propylene oxide represented by the general formula (II) may be either a random copolymer or a block copolymer, but is more preferably a block copolymer.

<Photosensitive resin layer>
In the present embodiment, the photosensitive resin layer refers to a layer containing a resin that undergoes a chemical or physical change by the action of light. The photosensitive resin layer can be prepared from a photosensitive resin composition containing a binder resin, a compound having an ethylenically unsaturated bond, a photopolymerization initiator, and other additives as required.

Preferably, the photosensitive resin composition has the following components (a) to (c):
(A) Resin for binders having a carboxyl group content of 100 to 600 in terms of acid equivalent and a weight average molecular weight of 5,000 to 500,000: 20 to 90% by mass,
(B) Compound having ethylenically unsaturated bond: 3 to 70% by mass, and (c) Photopolymerization initiator: 0.1 to 20% by mass
including. Hereinafter, each component will be described in order.

(A) Binder Resin In general, the binder resin refers to a resin used to bind constituent components. The amount of the carboxyl group contained in the binder resin is preferably 100 to 600, more preferably 250 to 450, in terms of acid equivalent. An acid equivalent means the mass of resin for binders which has 1 equivalent of carboxyl groups in it. The carboxyl group in the binder resin is necessary to give the photosensitive resin layer developability or releasability with respect to an alkaline aqueous solution. The acid equivalent is preferably 100 or more from the viewpoint of development resistance, resolution, and adhesion, and is preferably 600 or less from the viewpoint of developability and peelability.

  The weight average molecular weight of the binder resin is preferably 5,000 to 500,000. The weight average molecular weight of the binder resin is preferably 500,000 or less from the viewpoint of resolution, and is preferably 5,000 or more from the viewpoint of edge fuse. The edge fuse means that when the photosensitive element is wound into a roll shape, for example, the photosensitive resin layer protrudes from the end surface of the roll during storage and protrudes from the inner layer or the outer layer stacked in layers. This is a phenomenon of adhesion to the photosensitive resin layer. When edge fuse occurs, the photosensitive resin layer on the end face that is adhered when unwinding the photosensitive element from the roll scatters as a chip, and this chip may be laminated or adhered to the mask, resulting in poor yield. is there. The weight average molecular weight of the binder resin is more preferably 5,000 to 200,000, and further preferably 5,000 to 100,000.

  The degree of dispersion of the binder resin (sometimes referred to as molecular weight distribution) is preferably about 1 to 6, and more preferably 1 to 4.

  The binder resin is obtained by copolymerizing one or more monomers from the following two types of monomers.

  The first monomer is a carboxylic acid or acid anhydride having one polymerizable unsaturated group in the molecule. Examples include (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester, and the like. In the present invention, (meth) acryl represents acryl and / or methacryl.

  The second monomer is a compound that is non-acidic and has one polymerizable unsaturated group in the molecule. This compound is selected so as to maintain various properties such as developability of the photosensitive resin layer, resistance in etching and plating processes, and flexibility of the cured film. Examples of this compound include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate; 2-hydroxypropyl (meth) acrylate; (meth) acrylonitrile; benzyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, furfuryl (meth) acrylate, tetrahydro Aryl (meth) acrylates such as furfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, cresyl (meth) acrylate, naphthyl (meth) acrylate; vinyl compounds having a phenyl group (E.g., styrene), or the like can be used. Styrene is preferred from the viewpoints of resolution and adhesion. Further, benzyl (meth) acrylate is preferred from the viewpoint of resolution and developer aggregation.

  Preferably, the binder resin is prepared by diluting a mixture of the first monomer and the second monomer with a solvent such as acetone, methyl ethyl ketone, or isopropanol, and adding benzoyl peroxide, azoisobutyro It is synthesized by adding an appropriate amount of a radical polymerization initiator such as nitrile and stirring with heating. Moreover, you may synthesize | combine, dripping a part of mixture in a reaction liquid. Further, after completion of the reaction, a solvent may be further added to adjust to a desired concentration. As synthesis means, bulk polymerization, suspension polymerization, or emulsion polymerization may be used in addition to solution polymerization.

  The content of the binder resin in the photosensitive resin composition is preferably 20 to 90 mass%, more preferably 30 to 70 mass%, based on the total mass of the photosensitive resin composition. From the viewpoint that the cured resist pattern formed by exposure and development has sufficient characteristics as a resist, for example, tenting, etching, and various plating processes, this ratio is 20% by mass or more and 90% by mass or less. preferable.

(B) Compound having an ethylenically unsaturated bond Examples of the compound having an ethylenically unsaturated bond include di (meth) acrylates of alkylene glycol in which alkylene oxide is added to both ends of bisphenol A, and 4-nonylphenylheptaethylene. Glycol dipropylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, phenoxyhexaethylene glycol acrylate, reaction product of half ester compound of phthalic anhydride and 2-hydroxypropyl acrylate and propylene oxide (product name, manufactured by Nippon Shokubai Chemical Co., Ltd.) OE-A 200), 4-normal octylphenoxypentapropylene glycol acrylate, 1,6-hexanediol (meth) acrylate, 1,4-cyclohexanediol (Meth) acrylate, polypropylene glycol di (meth) acrylate, polyoxyalkylene glycol di (meth) acrylate such as polyethylene glycol di (meth) acrylate, 2-di (p-hydroxyphenyl) propane di (meth) acrylate, glycerol tri ( (Meth) acrylate, pentaerythritol penta (meth) acrylate, trimethylolpropane triglycidyl ether tri (meth) acrylate, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, hexamethylene diisocyanate and nonapropylene glycol monomethacrylate Polyfunctional (meth) acrylates containing urethane groups such as urethanized products, and polyfunctional (meth) acrylates of isocyanuric acid ester compounds It is. These may be used alone or in combination of two or more.

  It is preferable that the content rate of the compound which has an ethylenically unsaturated bond in the photosensitive resin composition is 3-70 mass% on the basis of the total mass of the photosensitive resin composition. It is preferably 3% by mass or more from the viewpoint of suppressing curing failure and development time delay, while it is preferably 70% by mass or less from the viewpoint of suppressing cold flow and cured resist peeling delay.

(C) Photopolymerization initiator As the photopolymerization initiator, a compound that is activated by various actinic rays such as ultraviolet rays and initiates polymerization may be used. In a preferred embodiment, 2,4,5-triarylimidazole dimer is used as a photopolymerization initiator from the viewpoint of high resolution. The covalent bond connecting the two lophine groups in the imidazole dimer is 1,1'-, 1,2'-, 1,4'-, 2,2'-, 2,4'- or 4,4. A compound attached to the '-position, but attached to the 1,2'-position is preferred. Examples of the 2,4,5-triarylimidazole dimer include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis- ( m-methoxyphenyl) imidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, and the like. In particular, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer is preferable.

  Further, a system in which 2,4,5-triarylimidazole dimer and p-aminophenyl ketone are used in combination is preferable from the viewpoints of sensitivity and resolution. Examples of p-aminophenyl ketone include p-aminobenzophenone, p-butylaminoacetophenone, p-dimethylaminoacetophenone, p-dimethylaminobenzophenone, p, p'-bis (ethylamino) benzophenone, p, p'- Examples thereof include bis (dimethylamino) benzophenone [Michler's ketone], p, p′-bis (diethylamino) benzophenone, p, p′-bis (dibutylamino) benzophenone.

  Examples of photopolymerization initiators other than the compounds shown above include quinones such as 2-ethylanthraquinone and 2-tert-butylanthraquinone, aromatic ketones such as benzophenone, benzoin and benzoin methyl ether. Benzoin ethers such as benzoin ethyl ether, acridine compounds such as 9-phenylacridine, and ketals such as benzyldimethylketal and benzyldiethylketal. Further, for example, a combination of a thioxanthone such as thioxanthone, 2,4-diethylthioxanthone, or 2-chlorothioxanthone and a tertiary amine compound such as a dimethylaminobenzoic acid alkyl ester compound may be used as a photopolymerization initiator. it can.

  As photopolymerization initiators other than the compounds shown above, 1-phenyl-1,2-propanedione-2-O-benzoyloxime, 1-phenyl-1,2-propanedione-2- (O— And oxime esters such as ethoxycarbonyl) oxime. Further, N-aryl α-amino acid compounds can also be used, and among these, N-phenylglycine is particularly preferable.

  It is preferable that the content rate of the photoinitiator in the photosensitive resin composition is 0.1-20 mass% on the basis of the total mass of the photosensitive resin composition. This content is preferably 0.1% by mass or more from the viewpoint of obtaining sufficient sensitivity, and is preferably 20% by mass or less from the viewpoint of preventing halation of light that has passed through a photomask during exposure.

  In addition to the components (a) to (c), the photosensitive resin composition includes the following discoloring agents, dyes, plasticizers, antioxidants, organic halogen compounds, and stabilizers (radicals) as necessary. A polymerization inhibitor, at least one compound selected from the group consisting of benzotriazoles, and carboxybenzotriazoles, etc.) can be added.

  As the color changing agent, a leuco dye or a fluoran dye can be used. Examples of leuco dyes include leuco crystal violet and leucomalachite green. The content of the color changing agent in the photosensitive resin composition is preferably 0.01% by mass or more from the viewpoint that sufficient colorability (color development) can be recognized based on the total mass of the photosensitive resin composition, From the viewpoint of obtaining hue stability and good image characteristics, 5% by mass or less is preferable.

  Examples of the dye include basic green 1 [633-03-4] (for example, Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), malachite green oxalate [2437-29-8] (for example, Aizen Malachite). Green, trade name, manufactured by Hodogaya Chemical Co., Ltd.), brilliant green [633-03-4], fuchsin [632-99-5], methyl violet [603-47-4], methyl violet 2B [8004-87-3 ], Crystal Violet [548-62-9], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (for example, Aizen Victoria Pure Blue BOH) , Product name, soil preservation Tani Kagaku Kogyo Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], etc., among which Basic Green 1 and Malachite Green Oxalate Salt or basic blue 7 is preferred.

  The dye content in the photosensitive resin composition is preferably 0.001 to 0.3% by mass, more preferably 0.01 to 0.12 based on the total mass of the photosensitive resin composition. % By mass. The content of the dye is preferably 0.001% by mass or more from the viewpoint that sufficient colorability can be recognized, while it is preferably 0.3% by mass or less from the viewpoint of maintaining sensitivity.

  Examples of the plasticizer include polyethylene glycol, polypropylene glycol, polyoxypropylene polyoxyethylene ether, polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxyethylene monomethyl ether, Glycol esters such as oxypropylene monoethyl ether and polyoxyethylene polyoxypropylene monoethyl ether, phthalic acid esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, citric acid Examples include triethyl acid, triethyl acetylcitrate, tri-n-propyl acetylcitrate, and tri-n-butyl acetylcitrate. It is.

  The content of the plasticizer in the photosensitive resin composition is preferably 5 to 50% by mass, more preferably 5 to 50% by mass, based on the total mass of the photosensitive resin composition. The content of the plasticizer is preferably 5% by mass or more from the viewpoint of suppressing development time delay and imparting flexibility to the cured film, while being 50% by mass or less from the viewpoint of suppressing insufficient curing or cold flow. preferable.

  As the antioxidant, phosphites are preferably used. Examples of phosphites include triphenyl phosphite (Asahi Denka Kogyo Co., Ltd., trade name: TPP), tris (2,4-di-t-butylphenyl) phosphite (Asahi Denka Kogyo Co., Ltd., trade name) 2112), tris (monononylphenyl) phosphite (Asahi Denka Kogyo Co., Ltd., trade name: 1178), bis (monononylphenyl) -dinonylphenyl phosphite (Asahi Denka Kogyo Co., Ltd., trade name: 329K). It is done.

  The content of the antioxidant in the photosensitive resin composition is preferably 0.01 to 0.8% by mass, more preferably 0.01 to 0.8%, based on the total mass of the photosensitive resin composition. 3% by mass. When the content of the antioxidant is 0.01% by mass or more, the effect of excellent hue stability of the photosensitive resin composition is exhibited, and the sensitivity at the time of exposure of the photosensitive resin composition tends to be improved. On the other hand, if it is 0.8 mass% or less, it is preferable because the color stability is suppressed and the hue stability is improved and the adhesiveness is also improved.

  Examples of the organic halogen compound include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzyl bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris ( 2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, and chlorinated triazine compounds. Of these, tribromomethylphenylsulfone is particularly preferably used.

  The content of the organic halogen compound in the photosensitive resin composition is preferably 0.01% by mass or more from the viewpoint of improving sensitivity, and 3% by mass from the viewpoint of hue stability, based on the total mass of the photosensitive resin composition. The following is preferred.

  In order to improve the thermal stability and storage stability of the photosensitive resin composition, the photosensitive resin composition contains at least one selected from the group consisting of radical polymerization inhibitors, benzotriazoles, and carboxybenzotriazoles. The compound can be added as a stabilizer.

  Examples of the radical polymerization inhibitor include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2′-methylenebis. (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), nitrosophenylhydroxyamine aluminum salt, diphenylnitrosamine and the like.

  Examples of benzotriazoles include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis (N-2-ethylhexyl) aminomethylene-1,2,3-benzotriazole, Examples thereof include bis (N-2-ethylhexyl) aminomethylene-1,2,3-tolyltriazole and bis (N-2-hydroxyethyl) aminomethylene-1,2,3-benzotriazole.

  Examples of carboxybenzotriazoles include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, and N- (N, N-di-2-ethylhexyl) aminomethylene. Examples thereof include carboxybenzotriazole, N- (N, N-di-2-hydroxyethyl) aminomethylenecarboxybenzotriazole, N- (N, N-di-2-ethylhexyl) aminoethylenecarboxybenzotriazole and the like.

  The total content of the radical polymerization inhibitor, benzotriazoles and / or carboxybenzotriazoles in the photosensitive resin composition is preferably 0.01 to 3% by mass, based on the total mass of the photosensitive resin composition. More preferably, it is 0.05-1 mass%. The total content is preferably 0.01% by mass or more from the viewpoint of imparting storage stability to the photosensitive resin composition, and is preferably 3% by mass or less from the viewpoint of maintaining sensitivity.

<Protective film>
A protective film can be further laminated on the photosensitive element of this embodiment. Hereinafter, a method for producing a laminate in which a support film, a water-soluble resin layer, a photosensitive resin layer, and a protective film are sequentially laminated will be described.

<Method for producing photosensitive element>
For example, first, the polyvinyl alcohol PVA-205 resin manufactured by Kuraray Co., Ltd. and the compound represented by the above general formula (I) are gradually added to water heated to 90 ° C. so that the solid content ratio becomes 10% by mass. In addition to stirring for about 2 hours, it is uniformly dissolved to obtain a water-soluble resin composition containing polyvinyl alcohol. Next, a uniform aqueous solution of the water-soluble resin composition containing polyvinyl alcohol is applied onto the support film using a blade coater, bar coater, or roll coater and dried to laminate the water-soluble resin layer on the support film. . In addition, it is preferable to adjust the viscosity of the uniform aqueous solution of the water-soluble resin composition containing polyvinyl alcohol to 10 to 500 mPa · s.

  On the water-soluble resin layer of the support film on which the water-soluble resin layer is laminated, the photosensitive resin composition is applied using a blade coater, a bar coater or a roll coater in the same manner as the application of the water-soluble resin composition. Dry and laminate a photosensitive resin layer on the water-soluble resin layer. The photosensitive resin layer is obtained by adding the photosensitive resin composition to a known solvent and adjusting the viscosity so as to be 500 to 4000 mPa · s at 25 ° C. Suitable solvents used include ketones such as methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropyl alcohol. Next, a photosensitive element can be prepared by laminating a protective film on the photosensitive resin layer thus laminated.

  The thickness of the photosensitive resin layer can be appropriately adjusted according to the application. The thickness of the photosensitive resin layer is preferably 40 μm or less, more preferably 30 μm or less, and further preferably 28 μm or less from the viewpoint of resolution. On the other hand, the thickness of the photosensitive resin layer is preferably 2 μm or more, more preferably 3 μm or more from the viewpoint of followability.

<Method for forming resist pattern>
A resist pattern can also be formed using the photosensitive element of this embodiment. Preferably, the resist pattern is formed by laminating the photosensitive element of the present embodiment on the surface of a metal plate or a metal-coated insulator, peeling off the support film, performing exposure with ultraviolet rays, and then developing it. A step of removing the exposed portion.

<Conductor pattern manufacturing method>
A conductor pattern can also be manufactured using the photosensitive element of this embodiment. Preferably, the method for producing the conductor pattern includes a step of forming a resist pattern on the substrate by the method of forming the resist pattern to obtain a substrate having the resist pattern, and etching or plating the substrate having the resist pattern. Process.

<Method for manufacturing printed wiring board>
An example of a method for producing a printed wiring board using the photosensitive element of this embodiment will be described. This printed wiring board is manufactured through the following steps (1) to (5):

(1) Laminating step When the photosensitive element has a protective film or protective layer, the photosensitive element is adhered to a substrate such as a copper clad laminate or a flexible substrate using a hot roll laminator while removing the protective layer. .

(2) Exposure process The process which peels a support film from a photosensitive element, passes the mask film which has a desired wiring pattern, and exposes using an actinic-light source.

(3) Development process The process which melt | dissolves or disperses the water-soluble resin layer and the unexposed part of the photosensitive resin layer using an alkaline developing solution, and forms a cured resist pattern on a board | substrate.

(4) Etching step or plating step Etching solution is sprayed on the formed resist pattern to etch the copper surface not covered by the resist pattern, or copper, solder, nickel on the copper surface not covered by the resist pattern And a step of plating tin or the like.

(5) Stripping step A step of removing the resist pattern from the substrate using an alkaline stripping solution.

  More specifically, examples of the active light source used in the (2) exposure step include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, and a xenon lamp. Examples of the alkaline developer used in the above (3) development step include aqueous solutions of sodium carbonate, potassium carbonate and the like. These alkaline aqueous solutions are selected in accordance with the characteristics of the photosensitive resin layer, but generally an aqueous sodium carbonate solution of 0.5% by mass to 3% by mass is used. Said (4) etching process is performed by methods, such as acidic etching and alkali etching, according to DF to be used.

  More specifically, as the alkali stripping solution used in the above (5) stripping step, generally an alkaline aqueous solution stronger than the alkaline aqueous solution used in the development, for example, 1% by mass to 5% by mass of sodium hydroxide. And / or an aqueous solution of potassium hydroxide.

  When a plating process such as a semi-additive method is provided, the copper surface that appears under the resist pattern may be etched after the resist pattern is peeled off.

  The photosensitive element of the present embodiment includes a printed wiring board, a flexible substrate, a lead frame substrate, a COF substrate, a semiconductor package substrate, a liquid crystal transparent electrode, a liquid crystal TFT wiring, a plasma display panel (PDP) electrode, and the like. It is a photosensitive element suitable for manufacturing a conductor pattern.

  The various parameters described above are measured according to the measurement methods in the examples described later unless otherwise specified.

  The present embodiment will be described more specifically with reference to examples and comparative examples, but the present embodiment is not limited to the following examples unless it exceeds the gist. The physical properties in the examples were measured by the following methods:

<Average particle size of fine particles>
Using a laser diffraction / scattering particle size / particle size distribution measuring device, the particle size at an integrated value of 50% in the particle size distribution of the fine particles is calculated as the average particle size.

<Acid equivalent of binder resin>
Using a Hiranuma automatic titration apparatus (COM-555) manufactured by Hiranuma Sangyo Co., Ltd., a potentiometric titration method was performed using a 0.1 mol / L sodium hydroxide aqueous solution.

<Weight average molecular weight, number average molecular weight, and molecular weight distribution of binder resin>
Gel Permeation Chromatography (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 type, column: Shodex (registered trademark) manufactured by Showa Denko KK (KF-807, KF-806M, KF-806M, KF-802.5) 4 in series, moving bed solvent: tetrahydrofuran, polystyrene standard sample (use of calibration curve by Shodex STANDARD SM-105 manufactured by Showa Denko KK).

<Water-soluble resin layer compatibility>
After thoroughly stirring the aqueous solution of the water-soluble resin composition for forming the water-soluble resin layer, it was observed whether the water-soluble resin composition was uniformly compatible and ranked as follows.
○: The water-soluble resin composition is uniformly compatible and is colorless and transparent.
Δ: White turbidity is generated in the water-soluble resin composition.
X: The water-soluble resin composition is separated into two layers.

<Support film releasability>
The peeling behavior when peeling the polyethylene terephthalate film as the support film before exposure was ranked as follows.
(Circle): Only the polyethylene terephthalate film which is a support film peeled off.
(Triangle | delta): A water-soluble resin layer adhered partially to the polyethylene terephthalate film which is a support film, and it peeled off simultaneously.
X: The polyethylene terephthalate film as a support film and the water-soluble resin layer were peeled together (peeled between the water-soluble resin layer and the photosensitive resin layer).

<Developability>
First, the substrate surface of a 0.4 mm thick copper-clad laminate on which 35 μm rolled copper foil was laminated was jet scrubbed (manufactured by 3M Co., Ltd., Scotch Bright (registered trademark) HD # 600) to prepare an evaluation substrate.
Next, it laminated on the said evaluation board | substrate with the roll temperature of 105 degreeC with the hot roll laminator (Asahi Kasei Engineering Co., Ltd. product, AL-70), peeling off the protective film or protective layer of a photosensitive element. The air pressure was 0.35 MPa, and the laminating speed was 1.5 m / min.
Next, after peeling off the polyethylene terephthalate film, which is a support film, using a chromium glass photomask necessary for the evaluation of the photosensitive resin layer, an ultrahigh pressure mercury lamp (365 nm monochromatic light, Ushio Electric Co., Ltd., UPL- 03EX) was exposed at an exposure amount of 140 mJ / cm ² . However, in Comparative Examples 7 and 9, the exposure was performed without peeling off the polyethylene terephthalate film as the support film.
Further, 1 mass% Na ₂ CO ₃ aqueous solution 30 ° C. for a predetermined time sprayed, to dissolve away unexposed portions of the photosensitive resin layer. In this case, the minimum time required for the photosensitive resin layer in the unexposed portion to completely dissolve was set as the minimum development time. The actual development time was twice as long as the minimum development time to obtain a cured resist pattern.
Based on the minimum development time, the ranking was as follows:
○: Minimum development time is less than 25 seconds Δ: Minimum development time is 25 seconds or more and less than 30 seconds ×: Minimum development time is 30 seconds or more

<Resist shape>
The shape of the 10 μm line of the cured resist pattern obtained by the developing property evaluation procedure was ranked as follows.
○: The formed cured resist pattern is rectangular.
Δ: The formed cured resist pattern is not rectangular.
X: The formed cured resist pattern is not rectangular and the film is further reduced.

<Backlash of resist sidewall>
The resist sidewall shapes of the 10 μm line of the cured resist pattern obtained by the procedure of developing property evaluation were ranked as follows.
(Double-circle): There is almost no backlash in the formed resist side wall.
○: Slight backlash exists on the formed resist sidewall.
(Triangle | delta): Roughness exists in the place of the formed resist side wall.
X: Roughness exists everywhere on the formed resist sidewall.

<Exposure foreign matter failure>
A 10 μm line of the cured resist pattern obtained by the procedure for evaluating developability was observed and ranked as follows.
A: The formed resist pattern has almost no defects due to exposure foreign matter.
Δ: The formed resist pattern has slight defects due to exposed foreign matter.
X: The formed resist pattern has some defects due to exposed foreign matter.

<Stability of water-soluble resin layer>
The polyethylene terephthalate film, which is the support film for the photosensitive element laminated on the substrate, was peeled off, and after 30 minutes, it was exposed and developed using a chromium glass photomask. The dents on the resist surface of the 10 μm line of the obtained cured resist pattern were ranked as follows.
○: The formed resist surface has almost no dent.
Δ: Slight depressions exist on the formed resist surface.
X: A dent exists in some places on the formed resist surface.

<Support film peelability after storage>
The photosensitive element was laminated on the substrate and left for 72 hours in an environment of 23 ° C. and 50% humidity. Thereafter, the peeling behavior when peeling the polyethylene terephthalate film as the support film was ranked as follows.
(Circle): Only the polyethylene terephthalate film which is a support film peeled off.
(Triangle | delta): A water-soluble resin layer adhered partially to the polyethylene terephthalate film which is a support film, and it peeled off simultaneously.
X: The polyethylene terephthalate film as a support film and the water-soluble resin layer were peeled together (peeled between the water-soluble resin layer and the photosensitive resin layer).

[Examples 1 to 14 (Examples 9 and 10 are reference examples) , Comparative Examples 1 to 9]
A water-soluble resin composition for forming a water-soluble resin layer shown in Tables 1 to 6 is added to water heated to 90 ° C., thoroughly stirred, mixed, cooled to room temperature, and then a support film of 16 μm thickness. A polyethylene terephthalate film (Film-1, Toyobo Co., Ltd. “A-1517” manufactured by Toyobo Co., Ltd.) was coated uniformly on the surface opposite to the fine particle-containing resin layer surface using a blade coater, and 10% in a dryer at 95 ° C. It was dried for a minute to form a uniform water-soluble resin layer on the support film. The thickness of the water-soluble resin layer was adjusted to 1 μm, 3 μm, 5 μm, or 8 μm by adjusting the gap of the blade during coating. On the water-soluble resin layer laminated on the support film, the photosensitive resin composition for forming the photosensitive resin layer shown in Tables 1 to 6 is uniformly applied using a blade coater and dried at 95 ° C. for 3 minutes. Thus, a uniform photosensitive resin layer was formed on the water-soluble resin layer. The thickness of the photosensitive resin layer was 25 μm. Next, a 19 μm thick polyethylene film (manufactured by Tamapoly Co., Ltd., GF-818) was laminated as a protective film on the surface of the photosensitive resin layer to obtain a photosensitive element. On the other hand, about a comparative example, film-2 ("16FB40" by Toray Industries, Inc.) was used instead of film-1 in comparative examples 1-7, and a water-soluble resin layer was not used in comparative examples 6-9. The photosensitive element was obtained like the said Example except having laminated | stacked the photosensitive resin layer on the support film.

  Various evaluation was performed about the obtained photosensitive element. The results are shown in Tables 1-6.

The following contents can be read from the results of Tables 1-6.
First, it can be seen from a comparison between Examples and Comparative Examples that a resist pattern in which the backlash of the resist sidewall is reduced can be formed by using the photosensitive element of this embodiment.
Next, by comparing Examples 1-8 and 11-14 with Examples 9 and 10, the water-soluble resin layer contains the compound represented by the above general formula (I), thereby supporting after storage. It turns out that film peelability can be improved.

  The photosensitive resin composition and laminate according to the present invention are a printed wiring board, flexible printed wiring board, metal foil precision processing such as lead frame manufacturing or metal mask manufacturing, ball grid array (BGA) or chip size. A semiconductor package such as a package (CSP), a tape substrate such as TAB or COF, a semiconductor bump, an indium tin oxide (ITO) electrode or an address electrode, and an electromagnetic wave shield can be suitably used for the production.

Claims (6)

Having a laminated structure in which a support film, an intermediate layer, and a photosensitive resin layer are sequentially laminated;
Before Symbol support film, and the surface on which the intermediate layer is laminated on the opposite side, a biaxially oriented polyester film comprising a resin layer containing fine particles,
A resin layer containing the fine particles is laminated only on one surface of the biaxially oriented polyester film,
The intermediate layer, Ri soluble resin layer der, and
The water-soluble resin layer has the following general formula (I):

{Wherein R ₁ and R ₂ are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and A is a —CH ₂ CH ₂ O— unit and / or —CH ₂ CH (CH ₃ ) O—. 1 type or 2 types or more of a unit is included, or a repeating structure is represented. }
The photosensitive element characterized by including the compound represented by these.   The photosensitive element of Claim 1 which contains polyvinyl alcohol in the said water-soluble resin layer.   The photosensitive element according to claim 1, wherein the water-soluble resin layer contains 50% by mass to 100% by mass of polyvinyl alcohol based on the mass of the water-soluble resin layer.   The photosensitive element of any one of Claims 1-3 whose thickness of the said water-soluble resin layer is 1 micrometer-8 micrometers. The photosensitive element according to any one of claims 1 to 4 is laminated on the surface of a metal plate or a metal-coated insulator, the support film is peeled off, exposed to ultraviolet rays, and then unexposed portions are developed by development. A method for forming a resist pattern, comprising a removing step. A method for producing a conductor pattern, comprising a step of etching or plating a substrate on which a resist pattern is formed by the method according to claim 5 .