JP2011141451A - Photocrosslinkable resin composition - Google Patents

Abstract

An object of the present invention is to form a photocrosslinkable resin layer on a substrate having a conductive layer on the surface, perform a thinning process on the photocrosslinkable resin layer with an alkaline aqueous solution, and then perform exposure and development of a circuit pattern. In a method for producing a circuit board, the present invention is to provide a photocrosslinkable resin composition that is hardly affected by polymerization inhibition by oxygen even when the surface of the resin layer is exposed after the photocrosslinkable resin layer is thinned.
(A) a step of forming a photocrosslinkable resin layer containing a photocrosslinkable composition on a substrate provided with a conductive layer on the surface; (b) light of an uncured portion by an alkaline aqueous solution; A photocrosslinkable composition used in a method for producing a resist pattern including a step of thinning a crosslinkable resin layer, (c) a circuit pattern exposure step, and (d) a development step has a dialkylaminobenzene structure. A photocrosslinkable resin composition comprising a compound.
[Selection] Figure 1

Description

  The present invention relates to a photocrosslinkable resin composition.

  As a method of manufacturing printed wiring boards and lead frames, an etching resist layer is provided on an insulating substrate having a conductive layer on the surface or a circuit portion of the conductive substrate, and the exposed conductive layer of the non-circuit portion is removed by etching. There is a subtractive method for forming a conductive pattern. In addition, there are an additive method and a semi-additive method in which a conductive layer is provided on a circuit portion of an insulating substrate by a plating method.

  As electronic devices have become smaller and more multifunctional in recent years, printed wiring boards and lead frames used inside the devices have been increased in density and conductive patterns. Has a conductive pattern of 50 to less than 80 μm and a conductor gap of 50 to 80 μm. In addition, with higher density and finer wiring, ultrafine conductive patterns with a conductor width or conductor gap of less than 50 μm have been required. Along with this, the requirements for the accuracy and impedance of the conductive pattern are also increasing. In order to form such a fine conductive pattern, a semi-additive method has been studied instead of the subtractive method. However, there are problems such as a significant increase in the manufacturing process and insufficient adhesive strength of electrolytically plated copper. There was a problem. For this reason, the production of printed wiring boards and lead frames by the subtractive method has become the mainstream.

  In the subtractive method, the etching resist layer is formed by a photofabrication method, a screen printing method, an ink jet method or the like having an exposure and development process using a photosensitive material. Among these, the method using a sheet-like photocrosslinkable resin layer called a negative dry film resist in the photofabrication method is preferably used because it is easy to handle and can protect through holes by tenting. It has been.

  In the method using a photocrosslinkable resin layer, a photocrosslinkable resin layer containing a photocrosslinkable resin composition is formed on a substrate, and an etching resist layer is formed through an exposure and development process. In order to form a fine conductive pattern, it is indispensable to form a fine etching resist layer. Therefore, it is necessary to make the etching resist layer as thin as possible. For dry film resists that are common as photocrosslinkable resin layers, for example, if the film thickness is 10 μm or less, the etching resist layer may be peeled off or disconnected due to the inclusion of bubbles with dust as a core and a decrease in irregularity followability. There is a problem that it occurs, and it is difficult to form a fine etching resist layer.

  In order to solve such problems, a thick photocrosslinkable resin layer is formed on the substrate in advance, and then the photocrosslinkable resin layer is thinned using an alkaline aqueous solution, and then the circuit pattern is exposed and developed. There has been proposed a method of forming an etching resist layer by a resist pattern manufacturing method (see, for example, Patent Document 1).

  A method for producing a resist pattern described in Patent Document 1 will be described with reference to FIGS. In FIG. 1, an insulating substrate 5 having a conductive layer 4 on one surface is used as the substrate 2. In the step (a), the photocrosslinkable resin layer 1 is formed on the conductive layer 4 of the substrate 2. In the step (b), the uncured photocrosslinkable resin layer 1 is thinned with an alkaline aqueous solution. In the step (c), a portion of the photocrosslinkable resin layer 1 corresponding to the circuit pattern is exposed to form a crosslinked portion 3. In the step (d), the uncured photocrosslinkable resin layer 1 is removed by development to obtain a resist pattern.

  In FIG. 2, as the substrate 2, an insulating substrate 5 having holes 6 and having a conductive layer 4 provided on the surface and inside the holes is used. In the step (a), the photocrosslinkable resin layer 1 is formed on the conductive layer 4 on the surface of the substrate 2 so as to close the hole 6. In the step (e), a part of the photocrosslinkable resin layer 1 is exposed and crosslinked to form a crosslinked part 3. In FIG. 2, the hole 2 and its surroundings are exposed. In the step (b), the uncured photocrosslinkable resin layer 1 is thinned. In the step (c), a portion of the photocrosslinkable resin layer 1 corresponding to the circuit pattern is exposed to form a crosslinked portion 3. In the step (d), the uncured photocrosslinkable resin layer 1 is removed by development to obtain a resist pattern. According to the method shown in FIG. 2, a thick etching resist layer having a tenting strength can be formed on the hole and its peripheral part.

  However, the method of Patent Document 1 has some problems. The first problem is polymerization inhibition by oxygen. The photocrosslinkable resin layer is formed on the substrate in a state where it is laminated on the support layer film by a laminator apparatus. In step (b), before the photocrosslinkable resin layer is thinned, the support layer film is removed. It is necessary to peel off. Therefore, the surface of the photocrosslinkable resin layer after thinning is exposed to oxygen in the air, and polymerization inhibition due to oxygen tends to occur in the exposure in the step (c). In close contact exposure using a phototool, since oxygen in the air can be removed, polymerization inhibition hardly occurs. However, tackiness on the surface of the photocrosslinkable resin layer and defects due to foreign matters may be problematic. Therefore, if the support layer film is re-laminated after thinning, there is no problem of oxygen inhibition, and the photocrosslinkable resin layer surface becomes tack-free and the workability is improved, but an apparatus for re-lamination of the support layer film is necessary. The number of processes increases. Furthermore, since the resolution is lowered by the diffracted light of the support layer film, the reproducibility of high-definition lines may be inferior. Therefore, the photocrosslinkable resin layer thinned in the step (b) has a curability on the surface of the photocrosslinkable resin layer (hereinafter referred to as “surface curability”) in order to make it less susceptible to polymerization inhibition by oxygen. Is required to be high.

  The second problem is related to the level difference formed by the resist pattern manufacturing method of FIG. In step (c) of FIG. 2, even if an attempt is made to expose a circuit pattern by contact exposure, there is a step on the hole and its peripheral part, so that not only contact is insufficient, but a short defect due to light leakage occurs. It will be easier. In the case of non-contact exposure, a problem due to a step is less likely to occur, but polymerization inhibition due to oxygen occurs. Therefore, in order to avoid oxygen inhibition, even if the support layer film is re-laminated after the photocrosslinkable resin layer is thinned, the film cannot follow the step, and the resolution may be reduced by diffracted light around the step. It was. Furthermore, when the support layer film is re-laminated using a laminator apparatus or the like, a dent is generated in the uncured photocrosslinkable resin layer at a step, and the durability of the etching resist layer may be lowered.

  The third problem is a problem in the portion exposed in step (e) in FIG. 2 (hereinafter referred to as “thick film portion”). In the thick film part, not only the surface curability but also the curability in the inside or deep part (hereinafter referred to as “internal curability”, “deep curability”) becomes important, and if the internal curability or deep curability is insufficient, There was a tendency for the etching resist layer to peel off due to poor adhesion.

International Publication No. 2009/096438 Pamphlet

  An object of the present invention is (a) a step of forming a photocrosslinkable resin layer containing a photocrosslinkable resin composition on a substrate provided with a conductive layer on the surface, (b) uncured by an alkaline aqueous solution. In the photocrosslinkable resin composition used in the method for producing a resist pattern comprising the step of thinning the photocrosslinkable resin layer of (c), the exposure step of the circuit pattern, and (d) the development step, An object of the present invention is to provide a photocrosslinkable resin composition having high surface curability that is hardly affected by polymerization inhibition by oxygen even after the surface of the resin layer is exposed after the crosslinkable resin layer is thinned.

  Moreover, when including the process of exposing and hardening a one part photocrosslinkable resin layer between process (a) and process (b), not only surface curability but a thick film part is also included. The object is to provide a photocrosslinkable resin composition that can also provide internal curability or deep curability.

As a result of intensive studies to solve the above problems, the present inventors have
(A) a step of forming a photocrosslinkable resin layer containing a photocrosslinkable resin composition on a substrate having a conductive layer on the surface, (b) an uncured photocrosslinkable resin layer by an aqueous alkali solution In the photocrosslinkable resin composition used in the method for producing a resist pattern comprising the step of performing a thinning process of (c), an exposure step of a circuit pattern, and (d) a development step,
(A) a polymer containing a carboxyl group, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, (C) a photopolymerization initiator, and (D) a polymerization inhibitor. As a component (C), the compound having a dialkylaminobenzene structure is 4.0 to 15% by mass with respect to the total component (C), and 0.20 to 0.20 with respect to the photocrosslinkable resin composition. The present inventors have found a photocrosslinkable resin composition characterized by containing 0.60% by mass.

(A) a step of forming a photocrosslinkable resin layer containing a photocrosslinkable resin composition on a substrate having a conductive layer on the surface; (e) a part of the photocrosslinkable resin layer; A step of exposing and curing, (b) a step of thinning the uncured photocrosslinkable resin layer with an alkaline aqueous solution, (c) an exposure step of a circuit pattern, and (d) a resist pattern comprising a development step In the photocrosslinkable resin composition used in the production method,
(A) a polymer containing a carboxyl group, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, (C) a photopolymerization initiator, and (D) a polymerization inhibitor. As a component (C), the compound having a dialkylaminobenzene structure is 4.0 to 15% by mass with respect to the total component (C), and 0.20 to 0.20 with respect to the photocrosslinkable resin composition. Further, the acylphosphine oxide compound is contained in an amount of 20 to 75% by mass with respect to the entire component (C), and 1.00 to 3.00% by mass with respect to the photocrosslinkable resin layer. % Photocrosslinkable resin composition was found.

  In the photocrosslinkable composition of the present invention, as the component (C), the compound having a dialkylaminobenzene structure is 4.0 to 15% by mass relative to the total component (C), and the photocrosslinkable resin composition. 0.20 to 0.60% by mass, and even if the photocrosslinkable resin layer surface after thinning is exposed in an exposed state, the surface is hardly affected by polymerization inhibition by oxygen Curability is obtained.

  Inhibition of polymerization by oxygen means that the polymerization ability of peroxy radicals generated by the trapping of radicals generated by photopolymerization initiators and polymerization end radicals generated during the polymerization of photopolymerizable compounds is low. Is to stop. In particular, when the photocrosslinkable resin layer is thin, poor curing tends to occur. Specifically, when the thickness of the photocrosslinkable resin layer after thinning is less than 15 μm, phenomena such as the appearance of an induction period until the start of polymerization, a decrease in polymerization rate, and a decrease in the reaction rate of the photopolymerizable compound appear, Polymerization inhibition becomes conspicuous and resolution is lowered. By adding a compound having a dialkylaminobenzene structure having high electron donating properties and chain transfer ability, a peroxy radical having a hydrogen abstracting ability extracts hydrogen from the alkylamine to become an aminoalkyl radical, and polymerization is performed. Be started. Moreover, since the produced aminoalkyl radical can also capture oxygen, there is an effect of reducing the oxygen concentration in the system.

  Moreover, in the photocrosslinkable resin composition of the present invention, as the component (C), the acylphosphine oxide compound is further added in an amount of 20 to 75% by mass based on the total component (C), and the photocrosslinkable resin composition. (E) a step of exposing and curing a part of the photocrosslinkable resin layer between the step (a) and the step (b). When it contains, not only surface curability but internal curability or deep part curability of a thick film part improves.

  Surface curability, internal curability, and deep curability are affected by the absorbance of the photocrosslinkable resin layer. In general, the lower the absorbance, the lower the surface curability, and the higher the absorbance, the internal or deep curability. Therefore, in order to improve this, a plurality of photopolymerization initiators are combined. That is, a photopolymerization initiator having high initiator efficiency and excellent surface curability is combined with a photopolymerization initiator having a photobleaching effect and excellent in internal or deep curability. The photobleaching effect is that the P—O bond in the acylphosphine oxide compound is cleaved by the photoreaction and the conjugated system is broken, so that it does not absorb ultraviolet light after decomposition and the ultraviolet light is easily transmitted inside. is there. That is, the curability of the inside or the deep part of the thick film can be enhanced by gradually eliminating the filter effect that obstructs the ultraviolet transmission of the initiator itself by light irradiation.

It is a cross-sectional process drawing which shows an example of the production method of the resist pattern including the process of thinning a photocrosslinkable resin layer. It is a cross-sectional process drawing which shows an example of the production method of the resist pattern including the process of thinning a photocrosslinkable resin layer. It is sectional drawing which shows the cross-sectional shape of a resist pattern. It is sectional drawing which shows the cross-sectional shape of a resist pattern.

  Hereinafter, the photocrosslinkable resin composition of the present invention will be described in detail.

<Process (a)>
In the step (a), a photocrosslinkable resin layer containing the photocrosslinkable resin composition is formed on at least one surface of the substrate having a conductive layer on the surface. For the formation of the photocrosslinkable resin layer, for example, a thermocompression laminator device that presses and presses a heated rubber roll can be used. The heating temperature is preferably 100 ° C. or higher. The substrate may be subjected to pretreatment such as alkali degreasing and pickling.

  Examples of the substrate having a conductive layer on the surface include a printed wiring board and a lead frame substrate. Examples of the printed wiring board include a flexible substrate and a rigid substrate. The thickness of the insulating substrate of the flexible substrate is 5 to 125 μm, and a metal foil layer of 1 to 35 μm is provided as a conductive layer on both sides or one side, and the flexibility is high. As the material for the insulating substrate, polyimide, polyamide, polyphenylene sulfide, polyethylene terephthalate, liquid crystal polymer, or the like is usually used. The material having the metal foil layer on the insulating substrate is an insulating substrate by an adhesive method of bonding with an adhesive, a casting method of applying a resin liquid which is an insulating substrate material on the metal foil, a sputtering method or a vapor deposition method. Produced by any method such as sputtering / plating method, which forms a metal foil layer by electrolytic plating on a thin conductive layer (seed layer) with a thickness of several nanometers formed on a resin film, or laminating method, which is attached by hot press. May be used. As a metal of the metal foil layer, any metal such as copper, aluminum, silver, nickel, chromium, or an alloy thereof can be used, but copper is generally used.

  As a rigid substrate, a paper substrate or glass substrate soaked with epoxy resin or phenol resin is laminated to form an insulating substrate, and a metal foil is placed on one or both sides as a conductive layer, and heated and pressed. A laminated layer provided with a metal foil layer can be used. Moreover, the multilayer board which has a through-hole and a non-through-hole, and the multilayer shield board produced by laminating | stacking a prepreg, metal foil, etc. after an inner layer wiring pattern process is also mentioned. The thickness is 60 μm to 3.2 mm, and the material and thickness thereof are selected according to the final use form as a printed circuit board. Examples of the material for the metal foil layer include copper, aluminum, silver, and gold. Copper is the most common. Examples of these printed circuit boards are “Printed Circuit Technology Handbook” (edited by Japan Printed Circuit Industry Association, published in 1987, published by Nikkan Kogyo Shimbun Co., Ltd.) and “Multilayer Printed Circuit Handbook” (JA Scarlet). Ed., Published in 1992, published by Modern Chemical Co., Ltd.). Examples of the lead frame substrate include iron nickel alloy and copper alloy substrates.

  As a substrate provided with a conductive layer on the surface, a substrate having holes and a conductive layer provided on the surface and inside the holes can be used. For example, a substrate having a metal foil layer on the surface of an insulating substrate. On the other hand, a hole is formed by a drill or a laser, and then a plating process such as electroless plating or electrolytic plating is performed to form a plated metal layer on the surface including the inside of the hole.

  The photocrosslinkable resin layer is a resin layer in which the exposed portion is crosslinked and insolubilized in the developer. The thickness of the photocrosslinkable resin layer is preferably 15 to 100 μm, and more preferably 20 to 50 μm. If the thickness is less than 15 μm, resist peeling or disconnection may occur due to the mixing of bubbles with dust as a core and the uneven followability. On the other hand, when the thickness exceeds 100 μm, not only the production cost of the photocrosslinkable resin layer is increased, but also the edge fusion of the photocrosslinkable resin layer is remarkable and the storage stability may be deteriorated. The photocrosslinkable resin layer may have a structure sandwiched between a support layer film such as polyester and a protective film such as polyethylene. In this case, the protective film is peeled off and the photocrosslinkable resin layer and the support layer film are laminated. In this state, it is laminated.

<Process (e)>
The step (e) is provided between the step (a) and the step (b), and a part of the photocrosslinkable resin layer is exposed and cured. For example, using a substrate having a hole and a conductive layer provided on the surface and inside the hole, photocrosslinking of the hole and its peripheral part (hereinafter referred to as “land part”) so that tenting is possible. The photosensitive resin layer is exposed and cured. Exposure methods include xenon lamps, high-pressure mercury lamps, low-pressure mercury lamps, ultra-high-pressure mercury lamps, reflection image exposure using UV fluorescent lamps as light sources, single-sided or double-sided contact exposure using photo tools, proximity method, projection method, laser (gas Laser, laser diode, solid state laser) or direct drawing method (direct imaging) using UV as a light source. Among these, direct imaging does not require a photo tool and is an exposure method suitable for a wide variety of small lots and a short delivery time, and has recently attracted attention as an environment-friendly photolithography method.

<Step (b)>
In the step (b), the uncured photocrosslinkable resin layer is thinned with an alkaline aqueous solution. More specifically, a thinning process is performed by forming an insolubilized micelle layer on an uncured photocrosslinkable resin layer with a high-concentration alkaline aqueous solution, and then re-dispersing and dissolving at once by reducing the concentration. I do. When the support layer film is provided on the photocrosslinkable resin layer, the thinning treatment is performed after the film is peeled off. The thinning treatment is a treatment for reducing the thickness of the photocrosslinkable resin layer substantially uniformly. Specifically, the thickness is reduced to 0.05 to 0.9 times the thickness before the thinning treatment. Say that.

  Alkaline aqueous solution contains 5-20 mass% of inorganic alkaline compounds. If it is less than 5% by mass, the micelles are hardly insolubilized, so that the micelles solubilized in the middle of dissolution and removal are dissolved and diffused, and in-plane unevenness occurs in the thinning process. Moreover, when it exceeds 20 mass%, precipitation of an inorganic alkaline compound will occur easily and it is inferior to the temporal stability of a liquid, and workability | operativity. The pH of the solution is preferably in the range of 9-12. In addition, a small amount of a surfactant, an antifoaming agent, a solvent, and the like can be added as appropriate.

  Inorganic alkaline compounds include alkali metal carbonates such as lithium, sodium or potassium carbonates or bicarbonates, alkali metal phosphates such as potassium and sodium phosphates, lithium, sodium or potassium hydroxides, etc. Alkali metal hydroxides, alkali metal silicates such as potassium and sodium silicates, and alkali metal sulfites such as potassium and sodium sulfites can be used. Among these, it is preferable to include at least one of inorganic alkali compounds selected from alkali metal carbonates, alkali metal phosphates, alkali metal hydroxides, and alkali metal silicates. Furthermore, alkali metal carbonates are particularly preferred from the viewpoints of the ability to dissolve the photocrosslinkable resin layer, the buffering ability to maintain the pH of the treatment liquid, the maintainability of the apparatus, and the like.

  The step (b), which is a thinning treatment of the photocrosslinked resin layer, is preferably processed separately in at least two steps. First, by supplying an excessively high concentration aqueous alkali solution, the photocrosslinkable resin layer component that has been micellized in the middle of dissolution is once insolubilized to suppress dissolution and diffusion into the treatment liquid. Next, an aqueous solution or water having a pH of 5 to 10, more preferably a pH of 6 to 8, containing at least any one of inorganic alkali compounds selected from alkali metal carbonates, alkali metal phosphates, and alkali metal silicates is supplied. Then, the insolubilized photocrosslinkable resin layer component is redispersed and dissolved and removed. When the pH of the aqueous solution is less than 5, the photocrosslinkable resin component dissolved by redispersion aggregates and becomes insoluble sludge and adheres to the thinned photocrosslinkable resin layer surface. On the other hand, if the pH of the aqueous solution exceeds 10, dissolution and diffusion of the photocrosslinkable resin layer is promoted, and film thickness unevenness occurs in the surface, which is not preferable. The pH of the aqueous solution is appropriately adjusted using sulfuric acid, phosphoric acid, hydrochloric acid or the like. Further, it is preferable that the supply flow rate of the aqueous solution is large. If the supply flow rate is insufficient, the redispersibility of the insolubilized photocrosslinkable resin layer component is deteriorated, and poor dissolution tends to occur. As a result, precipitation of insoluble components is observed on the surface of the photocrosslinkable resin layer after thinning, and tackiness may become a problem.

  There are a dipping method, a battle method, a spray method, brushing, scraping and the like as a thinning method, and the spray method is most suitable from the viewpoint of the dissolution rate of the photocrosslinkable resin layer. In the case of the spray method, the treatment conditions (temperature, time, spray pressure) are appropriately adjusted according to the dissolution rate of the photocrosslinkable resin layer to be used. Specifically, the treatment temperature is preferably 10 to 50 ° C, more preferably 15 to 40 ° C, and further preferably 15 to 35 ° C. The spray pressure is preferably 0.01 to 0.5 MPa, and more preferably 0.02 to 0.3 MPa.

<Step (c)>
In step (c), the circuit pattern is exposed. Circuit pattern exposure methods include xenon lamps, high-pressure mercury lamps, low-pressure mercury lamps, ultra-high pressure mercury lamps, reflection image exposure using UV fluorescent lamps as light sources, single-sided or double-sided contact exposure using photo tools, proximity method, projection method, Examples include a direct drawing method (direct imaging). In the method for producing a resist pattern according to the present invention, since the surface of the resin layer is exposed after thinning the photocrosslinkable resin layer, the contact exposure method may cause defects due to foreign matter or scratches. is there. In addition, the photocrosslinkable resin layer after the thinning treatment may have tackiness and cause contamination of the phototool. Therefore, non-contact exposure other than the above-described contact exposure is considered to be effective without problems of foreign matter, scratches, and tackiness. In particular, direct imaging that does not require a photo tool is the most suitable exposure method. .

  Further, as a step (e) between the step (a) and the step (b), when the land portion is exposed in advance, there is a step in the exposed thick film portion and the thinned photocrosslinkable resin layer, In the contact exposure, the influence of the diffracted light is large, and the resolution may be lowered. Furthermore, since there are two exposure steps, the exposure method that requires a photo tool is disadvantageous in terms of cost. Therefore, non-contact direct imaging exposure is the most suitable exposure method because it does not cause a decrease in resolution due to diffracted light that occurs at the step between the land portion and the thin resin layer, and does not require a photo tool. It can be said.

<Photocrosslinkable resin composition>
The photocrosslinkable resin composition of the present invention comprises (A) a polymer containing a carboxyl group, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, and (C) light. It contains a polymerization initiator and (D) a polymerization inhibitor.

  (A) Examples of the polymer containing a carboxyl group include organic polymers such as acrylic resins, methacrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. Is mentioned. You may use these individually by 1 type or in combination of 2 or more types. It is preferable to use an acrylic resin because of its high solubility in an alkaline aqueous solution. As the acrylic resin, a monomer having (meth) acrylate as a main component and having an ethylenically unsaturated carboxylic acid and other copolymerizable ethylenically unsaturated groups (hereinafter referred to as a polymerizable monomer). Any acrylic polymer may be used as long as it is copolymerized.

  Examples of the (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, tetrahydrofur Furyl (meth) acrylate, 2- (dimethylamino) ethyl (meth) acrylate, 2- (diethylamino) ethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate Rate, 2,2,3,3-tetrafluoro propyl (meth) acrylate.

  Monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid are preferably used as the ethylenically unsaturated carboxylic acid, and dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid, and anhydrides and half esters thereof. It can also be used. Among these, acrylic acid and methacrylic acid are particularly preferable.

  Examples of the other polymerizable monomers include styrene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, p-methoxystyrene, p-ethoxystyrene, p-chlorostyrene, p-bromostyrene, (Meth) acrylonitrile, (meth) acrylamide, diacetone acrylamide, vinyl toluene, vinyl acetate, vinyl n-butyl ether and the like can be mentioned.

  (A) In the polymer containing a carboxyl group, as a combination of two or more kinds of polymers, for example, a combination of two or more kinds of polymers having different copolymerization components, two kinds having different mass average molecular weights Combinations of the above polymers and combinations of two or more types of polymers having different dispersities (mass average molecular weight / number average molecular weight) can be mentioned.

  (A) The acid value of the polymer containing a carboxyl group is preferably 50 to 350 mgKOH / g, and more preferably 100 to 300 mgKOH / g. When an alkaline aqueous solution is used in the thinning treatment, when the acid value is less than 50 mgKOH / g, not only the time until dissolution is prolonged, but there is a tendency that poor dissolution is likely to occur, whereas when it exceeds 350 mgKOH / g, The dissolution and diffusion in the alkaline solution tends to be too fast, making it difficult to control the film thickness in the thinning process. In addition, the durability of the photocrosslinked portion with respect to the developer may be reduced, and the photocrosslinked portion in step (c) may be dissolved in step (d).

  (A) The mass average molecular weight of the polymer containing a carboxyl group is preferably 10,000 to 150,000, and more preferably 10,000 to 100,000. When the mass average molecular weight is less than 10,000, durability against an alkaline aqueous solution tends to decrease, whereas when it exceeds 150,000, the time until dissolution tends to be too long.

  (A) The compounding quantity of a component is preferably 40-65 mass% with respect to the total amount of (A) component and (B) component, and it is more preferable that it is 45-55 mass%. When the blending amount of the component (A) is less than 40% by mass, the chemical strength and mechanical strength of the photocrosslinked portion tend to be low. Moreover, there exists a problem that film property worsens. When the blending amount of the component (A) exceeds 65% by mass, the photocrosslinking property may be deteriorated.

  (B) As a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, for example, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol; bisphenol A-type (meth) acrylate compound; a compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid; a urethane monomer such as a (meth) acrylate compound having a urethane bond in the molecule; nonylphenoxypolyethyleneoxy Acrylate; phthalic acid compounds such as γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl-o-phthalate; (Meth) acrylic acid alkyl ester, EO, PO modified nonylphenyl ( Data) acrylate, and the like. Here, EO and PO represent ethylene oxide and propylene oxide, the EO-modified compound has a block structure of ethylene oxide group, and the PO-modified compound has a block structure of propylene oxide group. Is. These photopolymerizable compounds can be used alone or in combination of two or more.

  (B) The compounding quantity of a component is preferably 35-55 mass% with respect to a photocrosslinkable resin layer, and it is more preferable that it is 40-50 mass%. When the blending amount of the component (B) is less than 35% by mass, a half-crosslinked region is likely to occur in an unexposed part due to the influence of halation on the surface of the base material when the film is thinned, and the resolution may deteriorate. If it exceeds 55% by mass, not only the tackiness of the film surface may become remarkable, but also the photocrosslinkable resin layer after curing may become brittle.

  Examples of the polymerization inhibitor (D) include hydroquinone, p-methoxyphenol, tert-butyl-catechol, 2,6-di-tert-butyl-p-cresol, pyrogallol, β-naphthol, phenothiazine and the like. These may be used alone or in combination of two or more.

  (D) 0.01-0.3 mass% is preferable with respect to a photocrosslinkable resin layer, and, as for the compounding quantity of a component, 0.03-0.2 mass% is more preferable. If it is less than 0.01% by mass, the effect of suppressing the polymerization reaction is small, and in the photocrosslinkable resin layer after thinning, a semi-crosslinked portion of an unexposed portion may easily occur. On the other hand, when it exceeds 0.3% by mass, the sensitivity of the photocrosslinkable resin layer is significantly lowered, and the exposed portion may be insufficiently crosslinked.

  Further, (E) an antihalation agent may be added to the photocrosslinkable resin layer. When the component (E) is contained, scattered light due to reflection on the surface of the substrate can be absorbed, and generation of a semi-crosslinked region in an unexposed portion can be suppressed. (E) Any antihalation agent may be used as long as it has an absorption wavelength region in the range of 280 to 430 nm. Acridine dye, aniline black, anthraquinone dye, azine dye, azo dye, azomethine dye, benzoquinone dye, naphthoquinone dye, indigoid Dyes, indophenol, indoaniline, indamine, naphtholimide dyes, nigrosine and indulin, nitro and nitroso dyes, oxazine and oxazine dyes, oxidation dyes, phthalocyanine dyes, polymethine dyes, quinophthalone dyes, sulfur dyes, triarylmethane and diarylmethane dyes , Thiazine dyes, thiazole dyes, xanthene dyes, antihalation dyes, inorganic and organic pigments, phenyl salicylates, benzophenones, benzotriazoles, and acrylates System ultraviolet absorbers, and the like.

  (E) The compounding quantity of a component should just be 0.05-0.5 mass% with respect to a photocrosslinkable resin layer. If it is less than 0.05% by mass, the effect of preventing the halation of the substrate surface may be insufficient. On the other hand, if it exceeds 0.5% by mass, the sensitivity of the photocrosslinkable resin layer will be significantly reduced, and in the exposed area. However, crosslinking may be insufficient.

  In order to suppress polymerization inhibition by oxygen even after the surface of the resin layer is exposed after the photocrosslinkable resin layer is thinned, the photocrosslinkable resin composition of the present invention comprises (C) a photopolymerization initiator, It contains a compound having a dialkylaminobenzene structure as a polymerization accelerator. As the compound having a dialkylaminobenzene structure, a dialkylaminobenzophenone compound and a dialkylaminobenzoate compound are preferable, and 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone, ethyl-4-dimethylaminobenzoate (trade name: DAROCUR EDB, manufactured by Ciba Specialty Chemicals), 2-ethylhexyl-4-dimethylaminobenzoate (trade name: DAROCUR EHA, manufactured by Ciba Specialty Chemicals), and the like.

  Content of the compound which has a dialkylaminobenzene structure is 4.0-15 mass% with respect to the whole (C) component, More preferably, it is 5.0-12 mass%, More preferably, it is 6.0- It is 9.0 mass%. Content with respect to a photocrosslinkable resin composition is 0.20-0.60 mass%, More preferably, it is 0.25-0.50 mass%, More preferably, it is 0.30-0.40 mass%. is there. When the compound having a dialkylaminobenzene structure is less than 4.0% by mass relative to the total component (C) or less than 0.20% by mass with respect to the photocrosslinkable resin composition, sufficient inhibition of polymerization by oxygen is achieved. It cannot be suppressed. On the other hand, if it exceeds 15% by mass with respect to the total component (C) or exceeds 0.60% by mass with respect to the photocrosslinkable resin composition, light absorption on the surface of the photocrosslinkable resin layer increases excessively. Thus, the photocrosslinkable resin layer after curing becomes an extremely inverted trapezoidal shape, and the adhesion to the substrate is insufficient, so that resist peeling is likely to occur.

  Further, in the resist pattern manufacturing method including the step (e), in order to obtain desired surface curability, internal curability, and deep curability in both the thick film portion before thinning and the thin film portion after thinning. (C) An acylphosphine oxide compound is further contained as a photopolymerization initiator. Content of an acyl phosphine oxide compound is 20-75 mass% with respect to the whole (C) component, Preferably it is 25-70 mass%, More preferably, it is 30-60 mass%. Content with respect to a photocrosslinkable resin composition is 1.00-3.00 mass%, Preferably it is 1.20-2.80 mass%, More preferably, it is 1.50-2.50 mass%. . Acylphosphine oxide compounds are 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name: DAROCUR TPO, manufactured by Ciba Specialty Chemicals), bis (2,4,6-trimethylbenzoyl) -phenylphosphine. Fin oxide (trade name: IRGACURE 819, manufactured by Ciba Specialty Chemicals) and the like. If the acylphosphine oxide compound is less than 20% by mass relative to the total component (C) or less than 1.0% by mass with respect to the photocrosslinkable resin composition, the effect of photobleaching cannot be sufficiently obtained. There is a case. On the other hand, when it exceeds 75% by mass with respect to the total component (C) or exceeds 3.0% by mass with respect to the photocrosslinkable resin composition, the internal curability or deep curability becomes significant, and halation occurs. The tailing due to may increase and may not be preferable.

  (C) Photopolymerization initiators other than compounds having a dialkylaminobenzene structure and acylphosphine oxide compounds include benzophenone compounds (benzophenone, 4-benzoyldiphenyl sulfide), benzoin compounds (benzoin, benzoin methyl ether, benzoin ethyl ether) Acetophenone compounds (acetophenone, 2,2-dimethoxy-2-phenylacetophenone), anthraquinone compounds (2-methylanthraquinone, 2-ethylanthraquinone), benzyl ketal compounds (acetophenone dimethyl ketal, benzyl dimethyl ketal), thioxanthone compounds (2, 4-dimethylthioxanthone, 2,4-diethylthioxanthone), bisimidazoles (2- (o-chlorophenyl) -4,5- Phenylimidazole 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.

  The component (C) other than the compound having a dialkylaminobenzene structure and the acylphosphine oxide compound is preferably 1 to 10% by mass, and 2 to 8% by mass with respect to the photocrosslinkable resin composition. More preferred. If the amount is less than 1% by mass, the photocrosslinkability tends to be insufficient. On the other hand, if the amount exceeds 10% by mass, light absorption on the surface of the photocrosslinkable resin layer increases excessively, and light in the photocrosslinkable resin layer increases. There is a tendency for crosslinking to be insufficient.

<Step (d)>
In the step (d), the photocrosslinkable resin layer that has not been photocrosslinked is removed with a developing solution to form an etching resist layer. As a developing method, a developer corresponding to the photocrosslinkable resin layer to be used is used, and spray is sprayed from the vertical direction of the substrate toward the substrate surface. In general, an aqueous sodium carbonate solution of 0.3 to 2% by mass is used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this Example.

Examples 1-34, Comparative Examples 1-29
(Preparation of photocrosslinkable resin composition solution)
Each component shown to Tables 1-6 was mixed, and the photocrosslinkable resin composition solution was obtained. The unit of each component compounding amount in Tables 1-6 is a mass part. In addition, (A) component represents the mass part of a solution. Tables 7 to 12 show the content (% by mass) of the compound having a dialkylaminobenzene structure and the acylphosphine oxide compound with respect to the component (C) and the photocrosslinkable resin composition.

In Tables 1 to 6, the component (A) is as follows.
Component (A-1): a copolymer resin obtained by copolymerizing methyl methacrylate / n-butyl acrylate / methacrylic acid at a mass ratio of 64/15/21 (40% by mass solution using 1-methoxy-2-propanol as a solvent)

In Tables 1 to 6, the component (B) is as follows.
Component (B-1): 2,2′-bis (4-methacryloxypentaethoxyphenyl) propane (trade name: BPE-500, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Component (B-2): trimethylolpropane triacrylate (trade name: TMP-A, manufactured by Kyoeisha Chemical Co., Ltd.)

In Tables 1 to 6, the component (C) is as follows.
(C-1) component; 2- (2'-chlorophenyl) -4,5-diphenylimidazole dimer (C-2) component; 4,4'-diethylaminobenzophenone (C-3) component; ethyl-4- Dimethylaminobenzoate (trade name: DAROCUR EDB, manufactured by Ciba Specialty Chemicals)
Component (C-4): 2-ethylhexyl-4-dimethylaminobenzoate (trade name: DAROCUR EHA, manufactured by Ciba Specialty Chemicals)
Component (C-5): 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (trade name: DAROCUR TPO, manufactured by Ciba Specialty Chemicals)
Component (C-6): bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (trade name: IRGACURE 819, manufactured by Ciba Specialty Chemicals)

In Tables 1 to 6, the component (D) is as follows.
(D-1) component; p-methoxyphenol

(Preparation of dry film resist)
On the support layer film (film thickness 25 μm) made of a polyester film, the photocrosslinkable resin composition solution is applied using a slit die coater and dried, and then a protective film (film thickness 30 μm) made of a polyethylene film is formed. Lamination was performed to prepare dry film resists of Examples 1 to 34 and Comparative Examples 1 to 29 having a photocrosslinkable resin layer having a thickness of 40 μm.

(Preparation of etching resist layer 1)
<Process (a)>
A heat-resistant silicone rubber lining is surface-treated on a glass substrate epoxy resin copper clad laminate (area 170 mm × 255 mm, copper foil thickness 12 μm, substrate thickness 0.1 mm, product name: CCL-E170, manufactured by Mitsubishi Gas Chemical Company). Examples 1 to 15 and Comparative Example 1 at a roll temperature of 100 ° C., an air pressure of 0.30 MPa, and a laminating speed of 0.50 m / min while peeling off the protective film using a laminator for dry film equipped with a laminated roll. Each of ˜11 dry film resists was laminated.

<Step (b)>
After peeling off the support layer film, it was treated with a 10% by mass sodium carbonate aqueous solution (liquid temperature 25 ° C., spray pressure 0.05 MPa), and then adjusted to pH 8 by 0.1% by mass sodium carbonate aqueous solution (liquid temperature 25). (C, spray pressure 0.15 MPa) is sufficiently washed at a supply flow rate of 0.2 L / min per 1 cm ^{2 of the} photocrosslinkable resin layer, and then dried with cold air to obtain a thinned photocrosslinkable resin layer. It was.

<Step (c)>
Using a direct imaging exposure machine (device name: LI-8500, manufactured by Dainippon Screen Mfg. Co., Ltd.), patterns of line / space = 15/15, 20/20, 25/25 μm were exposed.

<Step (d)>
Development processing was performed using a 1% by mass aqueous sodium carbonate solution (solution temperature 30 ° C., spray pressure 0.15 MPa) to prepare a resist pattern.

(Evaluation of film reduction)
The film thickness of the resist pattern obtained using a laser microscope (device name: VK-8500, manufactured by Keyence Corporation) was measured, and film loss due to oxygen inhibition was evaluated as surface curability. The evaluation results are shown in Table 13 and Table 14.
○: Film loss is less than 0.5 μm Δ: Film loss is from 0.5 μm to less than 1.5 μm × ... Film loss is 1.5 μm or more

(Resolution evaluation)
The resolution of the resist pattern was observed using a scanning electron microscope (device name: JSM-6510, manufactured by JEOL Ltd.). The results are shown in Table 13 and Table 14.
○ ・ ・ ・ There is almost no undercut or skirting, and there is no resist peeling or short-circuit defect. △ ・ ・ ・ There is a line thickness due to undercut or skirting, but there is no practical problem. Is large, and there is a short defect that is a practical problem.

(Cross sectional shape evaluation)
The cross-sectional shape of the resist was observed using a scanning electron microscope (device name: JSM-6510, manufactured by JEOL Ltd.). The results are shown in Table 13 and Table 14. FIG. 3 is a cross-sectional view showing a cross-sectional shape of a resist pattern formed by a cross-linked portion 3 of a photo-crosslinkable resin layer produced on a substrate 2 in which a conductive layer 4 is placed on an insulating substrate 5. (E) evaluated.
(A): No film reduction, good resist shape (B): No film reduction, but undercut occurs (C): No film reduction, but there is significant undercut, resist Peeling occurs (D) ... Falling due to film reduction and halation (E) ... Falling due to film reduction and halation occurs significantly, resulting in resist short defects

  In Examples 1 to 15, the surface curability varies depending on the compounding amount of the compound having a dialkylaminobenzene structure relative to the photopolymerization initiator component, and is effective in improving the cross-sectional shape of the resist and suppressing film loss. I understood. In general, as the thickness of the photocrosslinkable resin layer after thinning becomes thinner, there is a tendency that film loss due to oxygen inhibition and tailing due to halation tend to occur, but it has a dialkylaminobenzene structure. A good resist pattern could be formed by adding an appropriate amount of the compound.

  In Comparative Examples 1 to 11, when the compounding amount of the compound having a dialkylaminobenzene structure is less than the range of the present invention, the surface curability is insufficient, the film is reduced and the tailing due to halation occurs, and the resist has a short defect. Had occurred. In addition, when the amount is larger than the range of the present invention, the surface curability becomes too high, the curing of the inside or the deep part of the photocrosslinkable resin layer becomes insufficient, and resist stripping occurs due to the cross-sectional shape of the resist being inverted trapezoidal. Was.

(Production of etching resist layer 2)
<Process (a)>
A glass-based epoxy resin copper-clad laminate is formed with 100 holes each having a diameter of 500 μm using a drill, and then a copper-clad laminate with holes in which a plated copper layer having a thickness of 10 μm is formed inside the through-hole and on the copper foil. Using a laminator for dry film equipped with a laminate roll with a heat-resistant silicon rubber lining surface treated on the plate, while peeling off the protective film, the roll temperature was 100 ° C., the air pressure was 0.30 MPa, and the laminating speed was 0.50 m / min. The dry film resists of Examples 16 to 34 and Comparative Examples 12 to 29 were laminated.

<Process (e)>
Before thinning the photocrosslinkable resin layer, use a direct imaging exposure machine (device name: LI-8500, manufactured by Dainippon Screen Mfg. Co., Ltd.) to expose only the land with a 100 μm land on one side of the hole did.

<Step (b)>
After curing the photocrosslinkable resin layer in the land portion, the support layer film is peeled off, and then the uncured photocrosslinkable resin layer other than the land portion has a thickness of 10, 15, 10, 5 μm. After treatment with a mass% sodium carbonate aqueous solution (liquid temperature 25 ° C., spray pressure 0.05 MPa), a 0.1 mass% sodium carbonate aqueous solution (liquid temperature 25 ° C., spray pressure 0.15 MPa) adjusted to pH 8 was added. The photocrosslinkable resin layer was sufficiently washed at a supply flow rate of 0.2 L / min per 1 cm ² , and then dried with cold air to obtain a thinned photocrosslinkable resin layer.

<Process (c), process (d)>
After the thinning treatment, the steps (c) and (d) were performed in the same manner as in Example 1 to produce a resist pattern. Development processing was performed using a 1% by mass aqueous sodium carbonate solution (solution temperature 30 ° C., spray pressure 0.15 MPa) to prepare a resist pattern.

(Evaluation of film reduction)
The film thickness of the resist pattern obtained using a laser microscope (device name: VK-8500, manufactured by Keyence Corporation) was measured, and film loss due to oxygen inhibition was evaluated as surface curability. The evaluation results are shown in Tables 15-18.
○: Film loss is less than 0.5 μm Δ: Film loss is from 0.5 μm to less than 1.5 μm × ... Film loss is 1.5 μm or more

(Resolution evaluation)
The resolution of the resist pattern was observed using a scanning electron microscope (device name: JSM-6510, manufactured by JEOL Ltd.). The results are shown in Tables 15-18.
○ ・ ・ ・ There is almost no undercut or skirting, and there is no resist peeling or short-circuit defect. △ ・ ・ ・ There is a line thickness due to undercut or skirting, but there is no practical problem. Is large, and there is a short defect that is a practical problem.

(Cross sectional shape evaluation)
The cross-sectional shape of the resist was observed using a scanning electron microscope (device name: JSM-6510, manufactured by JEOL Ltd.). The results are shown in Tables 15-18. FIG. 4 shows the cross-sectional shape of the resist pattern formed by the cross-linked portion 3 of the photo-crosslinkable resin layer produced on the substrate 2 having the hole 6 and the conductive layer 4 provided inside the hole and on the surface of the insulating substrate 5. It is sectional drawing shown, and it evaluated by these (A)-(E).
(A)... Thick film portion (land portion) and thin film portion (thinned photocrosslinkable resin layer) are not reduced and the resist shape is good.
(B) ... There is no film reduction in the thick film part and the thin film part, but undercut occurs in the thick film part (C) ... There is no film reduction in both the thick film part and the thin film part, but in the thick film part There is a remarkable undercut, and resist peeling occurs (D) ... there is no film reduction in the thick film part and thin film part, but an undercut occurs in the thin film part (E) ... there is no film reduction in the thick film part , Resist shape is good, but thinning and tailing due to halation occur in the thin film part (F) ... There is filming and tailing due to halation not only in the thick film part but also in the thin film part. Short defect occurs

(Cross sectional shape evaluation)
In Examples 16 to 34, a compound having a dialkylaminobenzene structure and an acylphosphine oxide compound were added in order to produce a good resist pattern in both the thick film portion and the thin film portion. The former was effective in suppressing film reduction and tailing due to halation, particularly due to surface curability. At that time, it was found that the addition of an acylphosphine oxide compound is very effective in order to avoid insufficient internal or deep curability at the thick film portion. By combining these two photopolymerization initiators in an appropriate amount and mixing them, it was possible to form a good resist pattern in both the thick film portion and the thin film portion.

  In Comparative Examples 12 to 29, when the compounding amount of the compound having a dialkylaminobenzene structure is less than the range of the present invention, the surface curability is insufficient, and not only the thin film part but also the thick film part is reduced in film thickness and halation. In particular, resist short defects occurred in the thin film portion. Further, when the amount is larger than the range of the present invention, the surface curability becomes too high, and a sufficient depth of curing cannot be obtained at the thick film portion, and the resist in the land portion is peeled off. On the other hand, if the amount of the acylphosphine oxide compound added for the purpose of improving the internal or deep curability of the thick film portion is less than the range of the present invention, the depth of cure of the thick film portion is insufficient, and the undercut Due to this, resist peeling occurred. Moreover, when it exceeded the range of this invention, the deep-part curability in a thin film part became remarkable, and the tailing resulting from halation increased.

  The present invention is widely used for producing a fine metal pattern using a subtractive method. For example, it can be used as a method for manufacturing a printed wiring board or a lead frame.

1 Photocrosslinkable resin layer (uncrosslinked part)
2 Substrate 3 Crosslinked portion of photocrosslinkable resin layer 4 Conductive layer 5 Insulating substrate 6 Hole

Claims (2)

(A) a step of forming a photocrosslinkable resin layer containing a photocrosslinkable resin composition on a substrate having a conductive layer on the surface, (b) an uncured photocrosslinkable resin layer by an aqueous alkali solution In the photocrosslinkable resin composition used in the method for producing a resist pattern comprising the step of performing a thinning process of (c), an exposure step of a circuit pattern, and (d) a development step,
(A) a polymer containing a carboxyl group, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, (C) a photopolymerization initiator, and (D) a polymerization inhibitor. As a component (C), the compound having a dialkylaminobenzene structure is 4.0 to 15% by mass with respect to the total component (C), and 0.20 to 0.20 with respect to the photocrosslinkable resin composition. A photocrosslinkable resin composition comprising 0.60% by mass. (A) a step of forming a photocrosslinkable resin layer containing the photocrosslinkable resin composition on a substrate having a conductive layer on the surface; (e) exposing a part of the photocrosslinkable resin layer; (B) a step of thinning the uncured photocrosslinkable resin layer with an alkaline aqueous solution, (c) a circuit pattern exposure step, and (d) a method for producing a resist pattern comprising a development step In the photocrosslinkable resin composition used in
(A) a polymer containing a carboxyl group, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, (C) a photopolymerization initiator, and (D) a polymerization inhibitor. As a component (C), the compound having a dialkylaminobenzene structure is 4.0 to 15% by mass with respect to the total component (C), and 0.20 to 0.20 with respect to the photocrosslinkable resin composition. Further, the acylphosphine oxide compound is contained in an amount of 20 to 75% by mass with respect to the entire component (C), and 1.00 to 3.00% by mass with respect to the photocrosslinkable resin layer. % Photocrosslinkable resin composition.

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