JP2006317542A - Photosensitive film, resist pattern forming method using the same and method for manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive film which is laminated with proper follow-up features of a photosensitive resin composition layer to unevenness of an adherend surface, even if the photosensitive resin composition layer is made thinner, such that occurrence of an unadhered portion between the adherend and the photosensitive resin composition layer is fully suppressed, and which can realize high production yield, and ensures superior resolution, adhesion and resist shape, even if the photosensitive resin composition layer is exposed to air during exposure. <P>SOLUTION: The photosensitive film is obtained by sequentially stacking a resin film 10, a cushion layer 12 and the photosensitive resin composition layer 14, wherein the cushion layer 12 can bind the resin film 10 and the photosensitive resin composition layer 14 and has higher binding force with respect to the resin film 10 than that to the photosensitive resin composition layer 14, and the photosensitive resin composition layer 14 comprises a photosensitive resin composition, containing a 2,4,5-triarylimidazole dimer and an α-aminoalkylphenone and will not exhibit tackiness at room temperature. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  In the field of manufacturing printed wiring boards, a photosensitive film obtained by laminating a photosensitive resin composition on a resin film is widely used as a resist material used for plating and etching. When manufacturing a printed wiring board using such a photosensitive film, first, the photosensitive film is laminated on the substrate, and after pattern exposure, the unexposed portion is removed with a developer, and further, plating or Etching is performed to finally peel off and remove the cured portion from the substrate.

  In recent years, the density of printed wiring boards has been increased, and a high resolution of the photosensitive film is required. In order to increase the resolution of the photosensitive film, it is effective to reduce the thickness of the photosensitive resin composition layer. However, since the amount of the photosensitive resin composition layer that follows the surface irregularities of the substrate decreases, In the photosensitive film, there is a problem that an unadhered portion between the substrate and the photosensitive resin composition layer increases, and a sufficient production yield cannot be obtained.

  Moreover, in the conventional photosensitive film, when the photosensitive resin composition layer is thinned, the resin film is required to have a predetermined thickness and hardness in order to maintain the strength required for the photosensitive film. Therefore, the flexibility of the entire photosensitive film is lowered, and the photosensitive resin composition layer hardly follows the unevenness of the surface of the substrate to be laminated. As a result, the substrate and the photosensitive resin composition layer are not bonded. There was a problem that the number of parts increased and a sufficient production yield could not be obtained.

  Various methods have been proposed to improve such problems. For example, a method of laminating a photosensitive film after applying water to the substrate (see, for example, Patent Document 1 and Patent Document 2), a substrate. After laminating a liquid resin to form an adhesive intermediate layer, a method of laminating a photosensitive film (see, for example, Patent Document 3), a method of laminating a photosensitive film under reduced pressure using a vacuum laminator (for example, , Patent Document 4 and Patent Document 5).

  In addition, in conventional photosensitive films, it is common to expose a pattern mask in close contact with a resin film that is a support film during exposure, but since light diffuses through the resin film, high resolution can be obtained. There was a limit. In response to the demand for high resolution, if the pattern mask can be directly adhered to the photosensitive resin composition layer for exposure, the resolution can be greatly improved. However, the conventional photosensitive resin composition layer has high adhesiveness, and when the pattern mask is directly adhered, the pattern mask becomes difficult to peel due to the adhesive property, and further, the pattern mask is contaminated. was there. In addition, when a pattern mask is directly adhered to the photosensitive resin composition layer for exposure, the photosensitive resin composition layer is exposed to the atmosphere. When the photosensitive resin composition layer is exposed to the atmosphere due to the mechanism, the photocuring reaction is inhibited by oxygen in the atmosphere, so that there is a problem that the degree of curing required in the subsequent circuit formation process cannot be obtained. there were. In order to improve these problems, a photosensitive film in which a non-adhesive photosensitive resin composition layer, an adhesive photosensitive resin composition layer, and a protective film are sequentially laminated on a resin film (for example, a patent) Document 6 and Patent Document 7) have been proposed.

JP 57-21890 A JP-A-57-21891 JP-A-52-154363 Japanese Patent Publication No.53-31670 Japanese Patent Laid-Open No. 51-63702 JP-A-2-230149 Japanese Patent Laid-Open No. 3-17650

  However, in the manufacturing methods described in Patent Documents 1 and 2, in order to uniformly deposit a thin layer of water, the substrate surface must be cleaned, and if there are small-diameter through-holes, In other words, the water and the photosensitive resin composition layer easily react with each other, and developability is deteriorated. Therefore, there is a problem that a sufficient production yield cannot be obtained.

  In addition, the manufacturing method described in Patent Document 3 has problems such as a decrease in developability and releasability of small-diameter through-holes, so that a sufficient manufacturing yield cannot be obtained, and costs increase due to liquid resin coating.

  Furthermore, in the manufacturing methods described in Patent Documents 4 and 5, since the apparatus is expensive and it takes time to evacuate, it is rarely used for forming a normal circuit, and as a laminate for a permanent mask used after forming a conductor. It is only used. Even when the permanent mask is laminated, further improvement in the followability to the conductor is desired.

  And when the photosensitive film of patent document 6 and 7 thins the photosensitive resin composition layer for further high resolution, the photosensitive resin composition which follows the surface unevenness | corrugation of a board | substrate reduces. In addition, there is a problem that an unadhered portion between the substrate and the photosensitive resin composition layer increases and a sufficient production yield cannot be obtained.

  The present invention has been made in view of the above problems, and even when the photosensitive resin composition layer is thinned, the photosensitive resin composition layer is laminated with good conformity to the unevenness of the adherend surface. In addition, the occurrence of an unadhered portion between the adherend and the photosensitive resin composition layer is sufficiently suppressed, a high production yield can be realized, and even when the photosensitive resin composition layer is exposed to the atmosphere during exposure An object of the present invention is to provide a photosensitive film capable of obtaining excellent resolution, adhesion and resist shape, a resist pattern forming method using the same, and a printed wiring board manufacturing method.

  In order to achieve the above object, the present invention comprises a resin film, a cushion layer formed on the resin film, and a photosensitive resin composition layer formed on the cushion layer. The resin film and the photosensitive resin composition layer can be bound, the binding force to the resin film is larger than the binding force to the photosensitive resin composition layer, and the photosensitive resin composition layer Is a photosensitive resin composition comprising a photosensitive resin composition containing at least 2,4,5-triarylimidazole dimer and α-aminoalkylphenone, and is a layer that does not exhibit tackiness at room temperature. I will provide a.

  Here, the photosensitive resin composition layer “does not exhibit adhesiveness at room temperature” means that even when the photosensitive resin composition layers are manually pressed at room temperature (23 ° C., 60% RH), they are peeled off. It means that the photosensitive resin composition layer has an adhesive (adhesive) strength that does not sometimes cause mutual adhesion. Specifically, the adhesive force of the photosensitive resin composition layer to the PET film at 23 ° C. and 60% RH (180 ° peel strength, test piece width 20 mm, pulling speed 300 mm / min, JIS Z 0237) is 2 N / m or less. When it is, it will not show adhesiveness at room temperature.

  Since the photosensitive film of the present invention has the above-described configuration, a photosensitive resin composition layer that cannot be laminated on a resin film with a conventional photosensitive film and does not substantially exhibit adhesiveness at room temperature is laminated. It becomes possible. The photosensitive film of the present invention can be exposed with a pattern mask directly attached to the photosensitive resin composition layer, and the resolution can be greatly improved. At this time, since the photosensitive resin composition layer does not substantially exhibit adhesiveness at room temperature, the pattern mask can be easily peeled off after exposure even if the pattern mask is directly adhered, and the pattern mask is contaminated. There is nothing. At this time, the photosensitive resin composition layer is exposed to the atmosphere, but the photosensitive resin composition layer is composed of 2,4,5-triarylimidazole dimer and α-aminoalkylphenone. Surprisingly, it is possible to sufficiently suppress the influence of curing inhibition due to oxygen in the atmosphere by being configured to include various types of materials at the same time. As a result, the photosensitive film of the present invention can obtain excellent resolution, adhesion and resist shape.

  Further, the photosensitive film of the present invention having a cushion layer has a photosensitive resin composition layer at the time of lamination due to the presence of the cushion layer even when the photosensitive resin composition layer is thinned for high resolution. The adherend surface can be closely adhered along the unevenness of the adherend surface, and the occurrence of an unbonded portion between the adherend and the photosensitive resin composition layer can be sufficiently suppressed, and a sufficient production yield can be obtained. Obtainable. Furthermore, since the cushion layer has a greater binding force to the resin film than to the photosensitive resin composition layer, the resin film and the cushion layer are integrated when the resin film is peeled from the photosensitive resin composition layer. As a result, it is possible to peel off at the same time, and work efficiency can be improved.

  Further, in the photosensitive film, the binding force of the cushion layer to the resin film is 10 N / m or more, and the binding force of the cushion layer to the photosensitive resin composition layer is 0.2 to 10 N / m. m is preferable.

  Thereby, when manufacturing a printed wiring board, after laminating the photosensitive resin composition layer in the photosensitive film of the present invention so as to come into contact with the substrate, before performing exposure, these are the resin film and the cushion layer. It becomes possible to peel easily from the photosensitive resin composition layer in a state of being bound and integrated.

  The present invention also includes a laminating step of laminating the photosensitive film of the present invention on the circuit forming substrate in the order of the photosensitive resin composition layer, the cushion layer, and the resin film, and an actinic ray to the photosensitive resin. An exposure step of irradiating a predetermined portion of the composition layer to form a photocured portion in the photosensitive resin composition layer, and a developing step of removing the photosensitive resin composition layer other than the photocured portion. A method for forming a resist pattern is provided.

  The present invention further provides a method for producing a printed wiring board, comprising etching or plating a circuit-forming substrate on which a resist pattern is formed by the resist pattern forming method of the present invention.

  In the method for forming a resist pattern and the method for producing a printed wiring board according to the present invention, since the photosensitive film according to the present invention is used, the photosensitive resin composition layer is laminated with good conformity to the unevenness of the circuit forming substrate surface. In addition, even when the photosensitive resin composition layer is exposed to the air during exposure, excellent resolution, adhesion, and resist shape can be obtained. As a result, it is possible to increase the density and resolution of the printed wiring board.

  According to the present invention, even when the photosensitive resin composition layer is thinned, the photosensitive resin composition layer is laminated with good conformity to the unevenness of the adherend surface, and the adherend and the photosensitive resin composition Generation of unbonded parts with the physical layer is sufficiently suppressed, and a high production yield can be realized. Even when the photosensitive resin composition layer is exposed to the atmosphere during exposure, excellent resolution, adhesion, and resist are obtained. A photosensitive film capable of obtaining a shape can be provided.

  Further, according to the present invention, it is possible to provide a resist pattern forming method and a printed wiring board manufacturing method capable of increasing the density and resolution of the printed wiring board.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, (meth) acryloyl group means acryloyl group and The corresponding methacryloyl group is meant.

(Photosensitive film)
FIG. 1 is a schematic sectional view showing a photosensitive film 1 of the present invention. As shown in FIG. 1, the photosensitive film 1 is capable of binding a resin film 10 and a photosensitive resin composition layer 14 that does not exhibit adhesiveness at room temperature, and the binding force to the resin film 10 is photosensitive. The cushion layer 12 is larger than the binding force to the adhesive resin composition layer 14.

  Here, when the binding force of the cushion layer 12 to the photosensitive resin composition layer 14 is t1, and the binding force of the cushion layer 12 to the resin film 10 is t2, t1 is preferably 0.2 to 10 N / m, More preferably, it is 0.2-5 N / m. If t1 is less than 0.2 N / m, air tends to easily enter between the cushion layer 12 and the photosensitive resin composition layer 14 at the time of lamination, and if it exceeds 10 N / m, the resin film 10 and the cushion layer. When peeling 12 from the photosensitive resin composition layer 14, the photosensitive resin composition layer 14 tends to be easily peeled off together.

  Further, t2 is preferably 10 N / m or more, and more preferably 100 N / m or more. When t2 is less than 10 N / m, the cushion layer 12 tends to be peeled from the resin film 10 when the resin film 10 and the cushion layer 12 are peeled from the photosensitive resin composition layer 14.

  Furthermore, when the photosensitive resin composition layer 14 does not exhibit tackiness at room temperature, and the adhesive strength when the photosensitive resin composition layers 14 are manually press-bonded at room temperature (23 ° C., 60% RH) is t3, t3 is preferably 2 N / m or less, and more preferably 1 N / m or less. If t3 exceeds 2 N / m, when the pattern mask is directly adhered to the photosensitive resin composition layer 14 during exposure, the peelability of the pattern mask is lowered and the pattern mask may be contaminated. is there.

  In addition, t1, t2 and t3 indicate 180 ° peel strength between the respective layers at 23 ° C. and 60% RH (also referred to as peel strength or peel adhesive strength), and the peel strength is tested according to JIS Z 0237. It can be measured under test conditions of a single width of 20 mm and a pulling speed of 300 mm / min.

  Further, the value of t2 / t1 is preferably 1.05 or more, more preferably 1.5 or more, and further preferably 2.0 or more. When the value of t2 / t1 is 1.05 or more, when the resin film 10 is peeled from the photosensitive resin composition layer 14, the resin film 10 and the cushion layer 12 are more reliably bound to each other. Tend to be peeled simultaneously.

  As the resin film 10 according to the present invention, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester is preferably used. In addition, such a resin film 10 may have a single-layer structure or a laminated structure in which films having a plurality of compositions are laminated.

  The thickness of the resin film 10 is preferably 2 to 100 μm, more preferably 5 to 20 μm, and particularly preferably 10 to 18 μm. If this thickness is less than 2 μm, wrinkles tend to occur when laminating to a substrate, and if it exceeds 100 μm, the flexibility of the photosensitive film 1 as a whole decreases, and the resin film 10 tends to be bulky when peeled and collected. There is.

  The photosensitive resin composition layer 14 according to the present invention is a layer made of a photosensitive resin composition containing 2,4,5-triarylimidazole dimer and α-aminoalkylphenone as essential components. The photosensitive resin composition constituting the photosensitive resin composition layer 14 further includes (A) a binder polymer, (B) a photopolymerizable compound having an ethylenically unsaturated bond, and (C) a photopolymerizable initiator. It is preferable that it contains.

  Here, as the 2,4,5-triarylimidazole dimer, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di ( Methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p -Methoxyphenyl) -4,5-diphenylimidazole dimer and the like. Further, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may be the same to give the target compound, or differently give an asymmetric compound. These can be used alone or in combination of two or more.

  As α-aminoalkylphenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name: IRGACURE369, manufactured by Ciba Specialty Chemicals), 2-methyl -1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (trade name: IRGACURE907, manufactured by Ciba Specialty Chemicals) and the like. These can be used alone or in combination of two or more.

  Since the photosensitive resin composition layer 14 includes 2,4,5-triarylimidazole dimer and α-aminoalkylphenone, the photosensitive resin composition layer 14 is exposed to the atmosphere during exposure. Even if exposed, it is possible to suppress the influence of curing inhibition due to oxygen in the atmosphere, and it is possible to suppress deterioration in characteristics such as adhesion, resolution, resist shape and the like after curing.

  The binder polymer as the component (A) preferably contains a carboxyl group from the viewpoint of alkali developability, for example, by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer. Can be manufactured. As the polymerizable monomer having a carboxyl group, methacrylic acid, acrylic acid, maleic acid and the like are preferable.

  (A) The acid value of the binder polymer is preferably 50 to 500 mgKOH / g, and more preferably 100 to 300 mgKOH / g. When the acid value is less than 50 mgKOH / g, the development time tends to be remarkably delayed, and when it exceeds 500 mgKOH / g, the developer resistance of the photocured resist tends to be lowered.

  (A) The weight average molecular weight of the binder polymer is preferably 5,000 to 300,000, and more preferably 10,000 to 150,000. When the weight average molecular weight is less than 5,000, the developer resistance tends to be remarkably lowered, and when it exceeds 300,000, the development time tends to be long. However, the weight average molecular weight and the number average molecular weight in the present invention are measured by gel permeation chromatography, and values converted to standard polystyrene are used.

  The binder polymer as component (A) preferably contains styrene or a styrene derivative as a polymerizable monomer from the viewpoint of flexibility. Examples of the styrene derivative include α-methylstyrene.

  When the styrene or styrene derivative is contained as a polymerizable monomer, it is preferably included in an amount of 0.1 to 70% by mass based on the total mass of the monomer from the viewpoint of improving both adhesion and peeling properties. 1 to 60% by mass, more preferably 1.5 to 50% by mass. If this content is less than 0.1% by mass, the adhesion tends to be inferior, and if it exceeds 70% by mass, the peel piece tends to be significantly large and the peel time tends to be long.

  Examples of the (A) binder polymer include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. From the viewpoint of alkali developability, an acrylic resin is preferable. These can be used alone or in combination of two or more.

  (A) The binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include polymerizable styrene derivatives substituted at the α-position or aromatic ring such as styrene, vinyl toluene, α-methylstyrene, acrylamide such as diacetone acrylamide, acrylonitrile, vinyl, and the like. -Esters of vinyl alcohol such as n-butyl ether, (meth) acrylic acid alkyl ester, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, ( (Meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acryl Acid, α-chloro ( T) Acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate and the like, Examples include fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid.

Examples of the (meth) acrylic acid alkyl ester include the following general formula (I):
^{_{CH 2 = C (R 1)}} -COOR 2 (I)
[Wherein, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 12 carbon atoms. ]
And compounds in which the alkyl group of these compounds is substituted with a hydroxyl group, an epoxy group, a halogen group, or the like.

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ² in the general formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, Nonyl group, decyl group, undecyl group, dodecyl group and structural isomers thereof can be mentioned. Examples of the monomer represented by the general formula (I) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (Meth) acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic acid nonyl ester, (Meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester, and the like. These can be used alone or in combination of two or more.

  In addition, (A) component binder polymer includes (phthalic anhydride), isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, (anhydrous) maleic acid, fumaric acid, adipic acid trimellitic anhydride, pyromellitic anhydride Divalent or higher carboxylic acids such as ethylene glycol, propylene glycol, 1,3-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, neopentyl glycol, hydrogenated bisphenol A, glycerin, trimethylolpropane, etc. Polyester resins obtained by esterification reaction with the above alcohols can also be used. Examples of the epoxy resin include bisphenol epoxy resin and novolac epoxy resin, and those added with a monovalent carboxylic acid such as acetic acid, oxalic acid and (meth) acrylic acid.

  These (A) binder polymers are used alone or in combination of two or more. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymerization components, two or more types of binder polymers having different weight average molecular weights, and two or more types of binder polymers having different degrees of dispersion are used. Examples thereof include a binder polymer. The dispersity here is a value of weight average molecular weight / number average molecular weight.

  The photopolymerizable compound having an ethylenically unsaturated bond as component (B) contains 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane from the viewpoint of improving resolution. It is preferable that the thickness of the photosensitive resin composition layer 14 is 0.1 to 15 μm. The thickness of the photosensitive resin composition layer 14 containing 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane is more preferable from the viewpoint of increasing the density of printed wiring and increasing the resolution. Is 1-15 μm, more preferably 2-7 μm.

  The 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane is used alone or in combination with other polymerizable compounds.

  Examples of the 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meta And bisphenol A-based (meth) acrylate compounds such as acryloxypolyethoxypolypropoxy) phenyl) propane and the like.

  Among these, as 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, for example, 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acrylo) Sinonaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl), 2,2 -Bis (4-((meth) acryloxydodecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl), 2,2-bis (4-((meth)) (Acryloxytetradecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl), 2,2-bis (4-((meth) acryloxyhexadecaethoxy) phenyl) 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name) 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). is there. These may be used alone or in combination of two or more.

  Examples of the 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4- ( (Meth) acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) Phenyl) propane, 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((me ) Acryloxynonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl) 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl), 2,2-bis (4- ((Meth) acryloxytetradecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl), 2,2-bis (4-((meth) acryloxyhexadeca) Propoxy) phenyl) and the like. These may be used alone or in combination of two or more.

  Furthermore, as the 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, for example, 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl ) Propane, 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane, etc. Can be mentioned. These may be used alone or in combination of two or more.

  (B) For the photopolymerizable compound having an ethylenically unsaturated bond, 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane as described above is preferably used. Also, various photopolymerizable compounds can be used. That is, for example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid, a urethane monomer, nonylphenyl Di-xylene (meth) acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β -Hydroxypropyl-β '-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester and the like.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 2 propylene groups. 14 polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane diethoxytri (meth) acrylate, Trimethylolpropane triethoxytri (meth) acrylate, trimethylolpropanetetraethoxytri (meth) acrylate, trimethylolpropane pentaethoxytri (meth) acrylate, tetramethylolmethanetri (meta) ) Acrylate, tetramethylolmethane tetra (meth) acrylate, polypropylene glycol di (meth) acrylate having 2 to 14 propylene groups, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. It is done.

  Examples of the α, β-unsaturated carboxylic acid include (meth) acrylic acid.

  Examples of the glycidyl group-containing compound include trimethylolpropane triglycidyl ether tri (meth) acrylate, 2,2-bis (4- (meth) acryloxy-2-hydroxy-propyloxy) phenyl, and the like.

  Examples of the urethane monomer include an addition reaction between a (meth) acrylic monomer having an OH group at the β-position and isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1,6-hexamethylene diisocyanate, and the like. Products, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate, and the like. Note that EO represents ethylene oxide, and the EO-modified compound has a block structure of an ethylene oxide group. PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide groups.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, (meth) acrylic acid 2-ethylhexyl ester, and the like. .

  These (B) photopolymerizable compounds having an ethylenically unsaturated bond, including 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane, are used alone or in combination of two or more. Is done.

  As the photopolymerization initiator which is component (C), the above-mentioned 2,4,5-triarylimidazole dimer and α-aminoalkylphenone can be used, but other photopolymerization initiators are further used. be able to. Examples of the (C) photopolymerization initiator include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-diaminobenzophenone, 4 Aromatic ketones such as methoxy-4′-dimethylaminobenzophenone, benzoic acid esters such as ethyl-4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 3-methylbutyl-4-dimethylaminobenzoate, 2- Ethyl anthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroa Quinones such as traquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl ether, benzoin Benzoin ether compounds such as phenyl ether, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzyl derivatives such as benzyldimethyl ketal, acridines such as 9-phenylacridine, 1,7-bis (9,9'-acridinyl) heptane Derivatives, N-phenylglycine, N-phenylglycine derivatives, coumarin compounds and the like can be mentioned. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. These are used alone or in combination of two or more.

  The blending amount of the component (A) is preferably 30 to 80 parts by mass, more preferably 40 to 70 parts by mass, with the total amount of the component (A) and the component (B) being 100 parts by mass. If this blending amount is less than 30 parts by mass, the photocured product tends to be brittle, and when used as a photosensitive film, the coating properties tend to be inferior, and if it exceeds 80 parts by mass, the photosensitivity tends to be insufficient. is there.

  The amount of component (B) is preferably 20 to 60 parts by mass, more preferably 30 to 55 parts by mass, with the total amount of component (A) and component (B) being 100 parts by mass. If this amount is less than 20 parts by mass, the photosensitivity tends to be insufficient, and if it exceeds 60 parts by mass, the photocured product tends to be brittle.

  The total amount of 2,4,5-triarylimidazole dimer and α-aminoalkylphenone and component (C) is 0.1 parts by weight, with the total amount of component (A) and component (B) being 100 parts by weight. It is preferable that it is 1-20 mass parts, and it is more preferable that it is 0.2-10 mass parts. If the blending amount is less than 0.1 parts by mass, the photosensitivity tends to be insufficient, and if it exceeds 20 parts by mass, the absorption on the surface of the composition increases during exposure and the internal photocuring is insufficient. Tend to be.

  In addition, the photosensitive resin composition layer 14 may include a dye such as malachite green, a photochromic agent such as tribromophenyl sulfone or leuco crystal violet, a thermochromic inhibitor, p-toluenesulfonamide, or the like, if necessary. Plasticizers, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal cross-linking agents, etc. (A) and ( B) About 0.01 to 20 parts by mass can be contained for each 100 parts by mass of the total component. These are used alone or in combination of two or more.

  The photosensitive resin composition layer 14 preferably has a thickness of 0.1 to 50 μm, more preferably 0.1 to 25 μm, from the viewpoint of increasing the density and resolution of printed wiring. It is more preferably ˜15 μm, particularly preferably 1 to 8 μm, and most preferably 2 to 7 μm. In the present invention, even when the photosensitive resin composition layer 14 is thinned in this way, the photosensitive resin composition layer 14 can be laminated with good followability along the unevenness of the adherend surface. It becomes.

  Further, the transmittance of the photosensitive resin composition layer 14 with respect to ultraviolet rays having a wavelength of 365 nm is preferably 5 to 75%, more preferably 7 to 60%, and particularly preferably 10 to 40%. . If the transmittance is less than 5%, the adhesion tends to be inferior, and if it exceeds 75%, the resolution tends to be inferior. The transmittance can be measured with a UV spectrometer, and examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  The cushion layer 12 according to the present invention is preferably made of a resin containing a copolymer of ethylene and a monomer copolymerizable with the ethylene, and the copolymer is an ethylene-vinyl acetate copolymer and / or More preferably, it is an ethylene-ethyl (meth) acrylate copolymer. Here, the proportion of the ethylene component based on the total amount of the monomer component in the ethylene-vinyl acetate copolymer, and the proportion of the ethylene component based on the total amount of the monomer component in the ethylene-ethyl (meth) acrylate copolymer are: These are all preferably 50 to 90% by mass, more preferably 50 to 80% by mass, and particularly preferably 50 to 70% by mass. When the proportion of ethylene is less than 50% by mass, even when any copolymer is used, the adhesion between the cushion layer 12 and the photosensitive resin composition layer 14 tends to be too high, and peeling tends to be difficult. On the other hand, when the proportion of ethylene exceeds 90% by mass, the adhesiveness between the cushion layer 12 and the photosensitive resin composition layer 14 becomes too small regardless of which copolymer is used. It tends to be difficult to produce the film 1.

  The thickness of the cushion layer 12 is preferably 1 to 100 μm, more preferably 5 to 50 μm, and particularly preferably 10 to 40 μm. When the thickness of the cushion layer 12 is less than 1 μm, the followability to the unevenness of the surface of the object to be laminated tends to decrease. On the other hand, when the thickness exceeds 100 μm, the cost tends to increase.

  The tensile elastic modulus of the resin constituting the cushion layer 12 is preferably 10 MPa or less, more preferably 5 MPa or less, and particularly preferably 3 MPa or less. When this tensile elastic modulus exceeds 10 MPa, there is a tendency for the followability to the unevenness of the surface of the object to be laminated to decrease.

  The tensile elastic modulus can be measured with a rheometer or the like. As a more specific measuring method, first, a resin constituting the cushion layer 12 dissolved in an organic solvent such as toluene is placed in a metal petri dish and dried at 60 to 90 ° C. for 30 minutes, and 5 mm wide and thick A test piece of 250 μm is prepared. Next, this test piece is pulled at a temperature of 23 ° C., a humidity of 60% RH, and a distance between grips of 5 mm. A tensile elastic modulus can be calculated | required using the first linear part of the curve which shows the relationship between the distortion of a test piece at this time, and a tensile stress.

  The elongation at break of the resin constituting the cushion layer 12 is preferably 1000% or less, more preferably 500% or less, and particularly preferably 300% or less. When the elongation at break exceeds 1000%, when the photosensitive film 1 is cut with a blade or the like, the cushion layer 12 protrudes from the cut surface, and it tends to be difficult to cut cleanly.

  The elongation at break can be measured with a rheometer or the like. As a more specific measuring method, first, a test piece having a width of 5 mm and a thickness of 250 μm is prepared in the same procedure as the measurement of the tensile elastic modulus. Next, the test piece is pulled under the same conditions as the measurement of the tensile elastic modulus, and the calculation formula {(A-5) ÷ 5} × 100 [%] is used from the distance Amm when the test piece breaks. Can be sought.

  In addition, the cushion layer 12 is a 2,4,5-triarylimidazole dimer, α-aminoalkylphenone, (B) component, or (C) component as long as the effect of the present invention is not impaired. It is preferable to contain. This prevents 2,4,5-triarylimidazole dimer, α-aminoalkylphenone, component (B), or component (C) from transferring to the cushion layer 12 from the photosensitive resin composition layer 14. Tend to be able to.

  The photosensitive film 1 of the present invention includes an adhesive layer and light absorption as necessary within the range not impairing the effects of the present invention, in addition to the resin film 10, the cushion layer 12, and the photosensitive resin composition layer 14 described above. An intermediate layer such as a layer or a gas barrier layer or a protective layer may be provided.

  In the photosensitive film 1 of the present invention, a cover film can be laminated on the surface F1 opposite to the side where the photosensitive resin composition layer 14 faces the cushion layer 12. The cover film is used as a protective film and is peeled off before laminating, so if it has flexibility and can be peelably adhered to the photosensitive layer and is not damaged at the temperature of the drying oven, Although not particularly limited, for example, paper, release paper, polyester such as polyethylene terephthalate, polyolefin such as polymethylpentene, polypropylene, polyethylene, polyamide such as nylon, cellulose such as cellophane, film such as polystyrene, and the like, It may be transparent or non-transparent, and may have been subjected to a release treatment. Examples of commercially available cover films include product name E-200H manufactured by Oji Paper Co., Ltd., and product name NF-13 manufactured by Tamapoli Co., Ltd.

  Although the thickness of the cover film is not particularly limited, it is preferably 10 to 30 μm, more preferably 10 to 25 μm in consideration of the size when the photosensitive film 1 is wound and stored in a roll shape. The thickness is preferably 10 to 20 μm.

  In the present invention, in order to laminate the cushion layer 12 on the resin film 10, for example, the resin constituting the cushion layer 12 having the above-described composition may be applied on the resin film 10. According to the above, the resin is dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof. It can apply | coat as a 50 mass% solution. Further, the resin constituting the cushion layer 12 can be melted and laminated on the resin film 10.

  Moreover, in order to laminate the photosensitive resin composition layer 14 on the cushion layer 12, for example, a photosensitive resin composition having the above-described composition may be applied on the cushion layer 12, but in the application, If necessary, dissolve the photosensitive resin composition in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof. And can be applied as a solution having a solid content of about 30 to 70% by mass.

(Resist pattern forming method and printed wiring board manufacturing method)
Next, a method for forming a resist pattern using the above-described photosensitive film of the present invention will be described with reference to FIGS.

  2A to 2E are cross-sectional views schematically showing a resist pattern forming method. In this forming method, first, as shown in FIG. 2A, the resin film 10, the cushion layer 12, and the photosensitive resin composition layer 14 are laminated in this order on the surface of the circuit forming substrate 18. The photosensitive film 1 is pressure-bonded using a roller 20 so that the photosensitive resin composition layer 14 is in contact with the circuit forming substrate 18, and the photosensitive film 1 is photosensitive on the circuit forming substrate 18 as shown in FIG. The lamination process which laminates | stacks the resin composition layer 14, the cushion layer 12, and the resin film 10 in this order is performed. Next, as shown in FIG. 2C, the cushion layer 12 and the resin film 10 are removed to obtain a laminated substrate including the photosensitive resin composition layer 14 on the circuit forming substrate 18.

  Next, as shown in FIG. 2D, by using a pattern mask 22 having a transparent portion with respect to actinic rays such as ultraviolet rays, actinic rays are applied to predetermined portions of the photosensitive resin composition layer 14 in the laminated substrate. An exposure process is performed to form a photosensitive portion by irradiation. Then, as shown in FIG. 2E, a developing process for removing the photosensitive resin composition layer 14 other than the photosensitive part is performed to form a resist pattern 24.

In the laminating step, as a method of laminating the photosensitive resin composition layer 14 on the circuit forming substrate 18, for example, while heating the photosensitive resin composition layer 14 to about 70 to 130 ° C., the circuit forming substrate. The method of laminating | stacking by crimping to 18 by the pressure of about 0.1-1 MPa (about 1-10 kgf / cm < ² >) is mentioned. At this time, lamination may be performed under reduced pressure from the viewpoint of further improving followability. In order to further improve the adhesion, the circuit forming substrate 18 may be preheated. The surface on which the circuit forming substrate 18 is laminated is usually a metal surface, but is not particularly limited. Furthermore, unevenness may be present on the surface of the circuit forming substrate 18, and by using the photosensitive film 1 of the present invention, it is possible to laminate with good conformity to the unevenness.

  In the exposure step, the photosensitive resin composition layer 14 that has been laminated is irradiated with actinic rays in an image form through a negative or positive pattern mask 22 called an artwork. As the light source of actinic light, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, or a xenon lamp that emits ultraviolet rays effectively is used. Moreover, what emits visible light effectively, such as a photographic flood light bulb and a solar lamp, is also used.

  The development step is performed by removing the unexposed portion by wet development, dry development or the like and developing it to form a resist pattern. In the case of wet development, a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, an organic solvent developer, or the like, for example, a known method such as spraying, rocking immersion, brushing, or scraping is used. Develop by method.

  As the developing solution, a safe and stable solution having good operability such as an alkaline aqueous solution is used. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium, or ammonium carbonate or bicarbonate, potassium phosphate, and phosphoric acid. Alkali metal phosphates such as sodium and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used. Moreover, as alkaline aqueous solution used for image development, 0.1-5 mass% dilute solution of sodium carbonate, 0.1-5 mass% dilute solution of potassium carbonate, 0.1-5 mass% dilute solution of sodium hydroxide, A dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred. The pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive resin composition layer 14. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.

  The aqueous developer is composed of water or an aqueous alkaline solution and one or more organic solvents. Here, as the base of the alkaline aqueous solution in the aqueous developer, in addition to the above-mentioned bases, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl- 1,3-propanediol, 1,3-diaminopropanol-2-morpholine and the like can be mentioned. The pH of the developer is preferably 8 to 12 and more preferably 9 to 10 within a range where the resist can be sufficiently developed. Examples of the organic solvent include triacetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono And butyl ether. These are used alone or in combination of two or more. The concentration of the organic solvent is usually preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability. Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer.

  Examples of the organic solvent developer include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. These organic solvents preferably add water in the range of 1 to 20% by mass in order to prevent ignition.

  In the development step, two or more development methods may be used in combination as necessary. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and the high pressure spray method is most suitable for improving the resolution.

As the treatment after development, the resist pattern may be further cured and used by performing heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 mJ / cm ² as necessary.

  Next, a method for manufacturing a printed wiring board using the above-described resist pattern forming method will be described. The printed wiring board manufacturing method is to etch or plate the circuit forming substrate on which the resist pattern is formed by the above-described resist pattern forming method.

  Etching or plating the circuit forming substrate is performed by etching or plating the surface of the circuit forming substrate by a conventionally known method using the developed resist pattern as a mask.

  As the etching solution used for the above etching, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, a hydrogen peroxide-based etching solution, and the like can be used. It is preferable to use a ferric solution.

  Examples of the plating method for performing the above plating include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, watt bath (nickel sulfate-nickel chloride) plating, nickel sulfamate plating, etc. Nickel plating, hard gold plating, and gold plating such as soft gold plating.

  After etching or plating, the resist pattern can be peeled off with a stronger alkaline aqueous solution than the alkaline aqueous solution used for development, for example. As this strongly alkaline aqueous solution, for example, a 1 to 10% by mass sodium hydroxide aqueous solution, a 1 to 10% by mass potassium hydroxide aqueous solution and the like are used. Examples of the peeling method include a dipping method and a spray method, and the dipping method and the spray method may be used alone or in combination. The printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board.

  Further, when the plating is performed on a circuit forming substrate including an insulating layer and a conductor layer formed on the insulating layer, it is necessary to remove the conductor layer other than the pattern. As this removal method, for example, a method of lightly etching after removing the resist pattern, or performing solder plating after the above plating, and then masking the wiring portion with solder by peeling off the resist pattern, and then conducting layer The method etc. which process using the etching liquid which can etch only are mentioned.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

(Examples 1-2 and Comparative Examples 1-4)
[Preparation of photosensitive resin composition layer material]
The materials shown in Table 1 were blended to prepare solutions of photosensitive resin composition layer materials (I) to (V).

[Production of cushion layer material]
The materials shown in Table 2 were blended to produce a cushion layer material (I) solution.

[Production of photosensitive film]
As Example 1, a polyethylene terephthalate film (trade name: G2-16, manufactured by Teijin Ltd.) having a thickness of 16 μm is used as a resin film, and a cushion layer material (I) solution thereon is dried to a thickness of 20 μm. And then dried for 10 minutes with a hot air convection dryer at 90 ° C. to form a cushion layer. Next, a solution of the photosensitive resin composition layer material (I) is uniformly applied on the cushion layer so that the thickness after drying becomes 6 μm, and dried for 5 minutes with a hot air convection dryer at 90 ° C. A photosensitive resin composition layer was formed. Thereby, the photosensitive film of Example 1 was obtained.

  The photosensitive films of Example 2 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1 except that the photosensitive resin composition layer material solution and the cushion layer material solution shown in Table 3 were used. did. In Comparative Example 4, the photosensitive resin composition layer was formed directly on the resin film without forming the cushion layer.

<Resolution, adhesion and resist shape evaluation test>
A polishing machine (manufactured by Sankeisha Co., Ltd.) with a brush equivalent to # 600 on the copper surface of a glass epoxy board (trade name: MCL-E67-35S, manufactured by Hitachi Chemical Co., Ltd.) with a 35 μm thick copper foil laminated on one side After being washed with water, washed with water and dried with an air flow to obtain a copper clad laminate.

After heating the obtained copper-clad laminate to 80 ° C., it is obtained in Examples 1-2 and Comparative Examples 1-4 using a high-temperature laminator (manufactured by Hitachi Chemical Co., Ltd., trade name: HLM-3000). The resulting photosensitive film was laminated on the substrate with the photosensitive resin composition layer facing the substrate and the resin film side touching the laminate roll to obtain a laminated substrate. The laminating roll speed during lamination was 1.5 m / min, the laminating roll temperature was 110 ° C., and the cylinder pressure of the roll was 0.4 MPa (4 kgf / cm ² ).

  The obtained laminated substrate was cooled to 23 ° C., and then the resin film was peeled off when there was no resin film and cushion layer or cushion layer.

And on the photosensitive resin composition layer, Hitachi Resolution Test Pattern No. as a negative for resolution and adhesion evaluation. 3 (trade name, manufactured by Hitachi Chemical Co., Ltd., line width: 6 to 47 μm, space width: 6 to 47 μm) was used, and an exposure machine (Oak Seisakusho, model: EXM-1201) having a high-pressure mercury lamp was used. Then, exposure was performed with an exposure amount of 100 mJ / cm ² .

After the exposure, the photosensitive resin composition layer is spray-developed with a 1% by mass aqueous sodium carbonate solution (30 ° C.) for 10 seconds (spray pressure: 0.18 MPa (1.8 kgf / cm ² )) to remove the unexposed portion. The resist pattern was formed by developing. The value of the minimum space width with no development residue of the obtained resist pattern was defined as the resolution, and the value of the minimum line width without the chipped resist pattern was evaluated as adhesion. In addition, it shows that resolution and adhesiveness are excellent, so that this value is small.

  In addition, the resist shape of the obtained resist pattern with a line width of 25 μm was observed with a scanning electron microscope to evaluate the quality of the resist pattern. These results are shown in Table 4.

<Unevenness follow-up evaluation test>
A negative photosensitive film H-9040 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was laminated on the copper-clad laminate in the same manner as in the resolution, adhesion, and resist shape evaluation test to obtain a laminated substrate. Then, a copper-clad laminate having a resist pattern formed is obtained in the same manner as in the resolution, adhesion, and resist shape evaluation tests except that a pattern mask having a line width / space width of 1000/100 (unit: μm) is used. It was. Next, the obtained copper-clad laminate was immersed in a 100 g / L ammonium persulfate aqueous solution (30 ° C.) for 1 to 10 minutes, and the resist pattern was stripped (3 mass% NaOH aqueous solution, 45 ° C., spray pressure: Peeling was performed at 0.2 MPa (2 kgf / cm 2), and uneven copper-clad laminates having different dent widths of 100 μm and dent depths of 1 to 10 μm in 1 μm increments were obtained.

Next, using the high temperature laminator, the photosensitive film obtained in Examples 1 and 2 and Comparative Examples 1 to 4 is directed to the copper-clad laminate with unevenness, and the resin film is a laminate roll. Was laminated on an uneven copper-clad laminate so as to touch the substrate, to obtain a laminated substrate. Also, lamination is performed so that the axis of the laminating roll and the length direction of the recess of the copper clad laminate with unevenness are parallel, laminating roll speed is 1.5 m / min, laminating roll temperature is 110 ° C., roll cylinder The pressure was 0.4 MPa (4 kgf / cm ² ).

  Subsequently, after cooling the obtained laminated substrate to 23 degreeC, the resin film was peeled when there was no resin film and a cushion layer, or a cushion layer.

Then, a pattern mask having a wiring pattern with a line width / space width of 100/100 (unit: μm) as a resolution evaluation negative on the photosensitive resin composition layer is intersected at right angles to the length direction of the recess of the substrate. Then, exposure was performed at an exposure amount of 100 mJ / cm ² using an exposure machine having a high-pressure mercury lamp lamp.

After the exposure, the photosensitive resin composition layer was spray-developed with a 1% by mass aqueous sodium carbonate solution (30 ° C.) for 10 seconds (spray pressure: 0.18 MPa (1.8 kgf / cm ² )), and portions other than the photocured portion The resist pattern was formed on the substrate by removing and developing. The substrate on which the resist pattern is formed is sprayed with cupric chloride etching solution (2 mol / L CuCl ₂ , 2N-HCl aqueous solution, 50 ° C.) (spray pressure: 0.2 MPa (2 kgf / cm ² )). The copper of the portion not protected by is dissolved, and the resist pattern is further stripped with a stripping solution (3 mass% NaOH aqueous solution, 45 ° C., spray pressure: 0.2 MPa (2 kgf / cm ² )). A printed wiring board on which the line was formed was produced.

  If the resist does not sufficiently follow the dents on the substrate, a gap will be created between the resist and the substrate, so that the copper line will penetrate the etchant at the intersection of the resist and the dent and the copper will dissolve. A continuous copper line cannot be obtained, resulting in a disconnection failure. And when each printed wiring board was produced using copper clad laminates having different dent depths, the dent depth (μm) at which the disconnection starts was determined as the ruggedness followability (the larger this value, the better the followability). The results are shown in Table 4. In addition, the uneven | corrugated followable | trackability range which can be used practically is generally considered to be 3 μm or more.

<Pattern mask contamination evaluation test>
Absorbance of 200 nm to 400 nm with a UV spectrometer (manufactured by Hitachi, Ltd., 228A type W beam spectrophotometer) using the transparent portion of the pattern mask used in the resolution, adhesion and resist shape evaluation tests. Was measured, and the pattern mask contamination was evaluated by comparing with the absorbance before resolution and adhesion evaluation. Here, when the absorbance of the pattern mask exceeded 101% as compared with that before the adhesion to the photosensitive resin composition layer, the pattern mask was considered to be contaminated. The results are shown in Table 4.

<Peel strength evaluation test>
Laminated substrates (test pieces A) obtained by laminating the photosensitive films of Examples 1 and 2 and Comparative Examples 1 to 3 on a copper clad laminate in the same manner as in the resolution, adhesion and resist shape evaluation tests, and copper clad After laminating the laminated substrate (test piece B) on which the cushion layer and the resin film were bonded with a double-sided tape on the laminate, and the photosensitive films of Examples 1-2 and Comparative Examples 1-4 on the copper-clad laminate In the case where there is no cushion layer and resin film, or the cushion layer is not present, the resin film is peeled off, and a laminated substrate in which a PET film (manufactured by Teijin DuPont, product name: G2-16) is laminated on the photosensitive resin composition layer ( Test piece C) was prepared. After these test pieces A to C (all 20 mm wide) were allowed to stand at 23 ° C. and 60% RH for 2 hours, the test piece B was placed between the cushion layer and the photosensitive resin composition layer using the test piece A. 180 ° peel strength (peeling strength) between the cushion layer and the resin film, between the photosensitive resin composition layer and the PET film using the test piece C, and a pulling speed of 300 mm using a rheometer. Measured at / min. The results are shown in Table 4.

  From the above result, it was confirmed that the photosensitive film of Examples 1-2 was able to obtain the excellent uneven | corrugated followability compared with the photosensitive film of Comparative Examples 1-4. Moreover, it was confirmed that the photosensitive films of Examples 1 and 2 have good resolution, adhesion, and resist shape. Furthermore, it was confirmed that the photosensitive films of Examples 1 and 2 had no pattern mask contamination, and the adhesive force between the photosensitive resin composition layer and the PET film was as small as 0.4 N / m. In the photosensitive films of Examples 1 and 2, the binding force between the resin film and the cushion layer is larger than the binding force between the cushion layer and the photosensitive resin composition layer. After laminating the conductive film on the copper clad laminate, it was confirmed that the resin film and the cushion layer can be easily peeled off from the photosensitive resin composition layer.

  As described above, according to the photosensitive film of the present invention, even when the photosensitive resin composition layer is thinned, the photosensitive resin composition layer is laminated with good conformity to the irregularities on the surface of the adherend, Since generation | occurrence | production of the non-adhesion part of a to-be-adhered body and the photosensitive resin composition layer is suppressed, a high manufacturing yield can be implement | achieved. Moreover, since the photosensitive film of this invention has the outstanding followable | trackability, it has the advantage that it can laminate as it is using the conventional laminating apparatus. Furthermore, the photosensitive film of the present invention can obtain excellent resolution, adhesion and resist shape even when the photosensitive resin composition layer is exposed to the atmosphere during exposure.

It is a schematic cross section of the photosensitive film concerning embodiment of this invention. (A)-(e) is process drawing which shows typically the formation method of the resist pattern using the photosensitive film of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive film, 10 ... Resin film, 12 ... Cushion layer, 14 ... Photosensitive resin composition layer, 18 ... Substrate for circuit formation, 22 ... Pattern mask.

Claims (4)

A resin film, a cushion layer formed on the resin film, and a photosensitive resin composition layer formed on the cushion layer,
The cushion layer is a layer capable of binding the resin film and the photosensitive resin composition layer, the binding force to the resin film is larger than the binding force to the photosensitive resin composition layer,
The photosensitive resin composition layer is composed of a photosensitive resin composition containing at least 2,4,5-triarylimidazole dimer and α-aminoalkylphenone, and is a layer that does not exhibit tackiness at room temperature. A photosensitive film characterized by   The binding force of the cushion layer to the resin film is 10 N / m or more, and the binding force of the cushion layer to the photosensitive resin composition layer is 0.2 to 10 N / m. Item 2. The photosensitive film according to Item 1. A laminating step of laminating the photosensitive film according to claim 1 or 2 on the circuit forming substrate in the order of the photosensitive resin composition layer, the cushion layer, and the resin film;
An exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an actinic ray to form a photocured portion in the photosensitive resin composition layer;
A developing step for removing the photosensitive resin composition layer other than the photocured portion;
A method of forming a resist pattern, comprising:   A method for producing a printed wiring board, comprising etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 3.

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