JP2010277051A - Photopolymerizable resin composition and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photopolymerizable resin composition which exhibits good resolution and adhesion after development, excels in dispersion stability in a developer, and avoids production of aggregates, and a photopolymerizable resin laminate having a photopolymerizable resin layer comprising the composition, and to provide a method for forming a resist pattern using the laminate and a method for producing a conductor pattern or the like. <P>SOLUTION: The photopolymerizable resin composition includes: (a) 10-90 mass% of a binder resin having a carboxyl group content of 100-600 in term of acid equivalent, containing ≥50 mass% of a specific monomer as a copolymerized component, and having a weight average molecular weight of 5,000-500,000; (b) 5-70 mass% of a photopolymerizable unsaturated compound; and (c) 0.01-20 mass% of a photopolymerization initiator, wherein the photopolymerizable unsaturated compound (b) includes specific compounds. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photopolymerizable resin composition and its use, and more specifically, a photopolymerizable resin laminate suitable for the production of conductor patterns such as printed wiring boards and lead frames including rigid boards and flexible boards, and uses thereof The present invention relates to a resist pattern forming method, a conductor pattern manufacturing method, a printed wiring board manufacturing method, a semiconductor package manufacturing method, a lead frame manufacturing method, and an uneven substrate manufacturing method.

For electronic devices such as personal computers and mobile phones, printed wiring boards and the like are used for mounting components and semiconductors. As a resist for manufacturing printed wiring boards and the like, a so-called dry film resist (hereinafter abbreviated as DFR) in which a support, a photopolymerizable resin layer, and a protective layer as necessary are further laminated has been used. The DFR is generally prepared by laminating a photopolymerizable resin layer on a support, and further laminating a protective layer on the photopolymerizable resin layer as necessary. The photopolymerizable resin layer used here is generally of an alkali development type using a weak alkaline aqueous solution as a developer.
To fabricate a printed wiring board or the like using DFR, first peel off the protective layer, then laminate the DFR on a permanent circuit fabrication substrate such as a copper-clad laminate or flexible substrate using a laminator, etc. The support is peeled off and exposed through a wiring pattern mask film or the like. Next, if there is a support, it is peeled off, and the unexposed portion of the photopolymerizable resin layer is dissolved or dispersed and removed with a developing solution to form a resist pattern on the substrate.

  After forming the resist pattern, the process of forming a circuit is roughly divided into two methods. The first method is a method in which after removing a copper surface such as a copper clad laminate not covered with a resist pattern by etching, the resist pattern portion is removed with an alkaline aqueous solution stronger than the developer. In this case, for simplicity of the process, a method (tenting method) in which a through hole (through hole) is covered with a cured film and then etched is frequently used. The second method is a method in which the copper surface of the above is subjected to plating treatment of copper, solder, nickel, tin, etc., and then the resist pattern portion is similarly removed, and the copper surface such as a copper-clad laminate appearing is etched ( Plating method). In any case, cupric chloride, ferric chloride, a copper ammonia complex solution or the like is used for etching.

  Responding to the recent miniaturization of printed wiring boards mounted on personal computers and the like, high resolution and adhesion of resists are required. High resolution is generally achieved by improving the crosslink density of the photopolymerizable resin composition. However, when the crosslink density is increased, the cured resist film becomes hard and brittle. When using the tenting method, it is required that the cured film does not break through the tenting process (tenting property), but the problem is that the tented property deteriorates due to the hardened film. To do. In addition, if the cured film is broken by pressure such as spraying in the development or etching process, the copper line is broken, causing a defect. Therefore, a resist having high resolution and good cured film flexibility and tenting properties is required. An attempt to improve the resolution and tenting properties includes an attempt to use a binder containing a urethane group (Patent Document 1).

In addition, the step of dissolving or dispersing and removing the unpolymerized portion of the photopolymerizable resin layer with a developer after exposure is referred to as a development step. Not all of the DFR components dissolve in the developer, and each time the development process is repeated, insoluble components with poor developer dispersibility increase and aggregates (scum) are generated. Aggregates re-adhere on the substrate, causing a short circuit failure in the tenting and etching methods, and may clog the developing tank piping.
Therefore, for the purpose of reducing aggregates, as a photopolymerizable unsaturated compound, an attempt to use an alkylphenol type monofunctional monomer having good developer dispersibility (Patent Document 2) or an attempt to use a phenoxy type monofunctional monomer (Patent) There is literature 3).

  However, a photopolymerizable resin composition that has excellent developer dispersion stability in the development process, does not generate aggregates, exhibits high resolution and adhesion of the resist, and has good tenting properties is still provided. However, further improvement is desired.

JP 2007-101681 A JP 2001-174986 A JP 2001-305730 A

  The present invention relates to a photopolymerizable resin composition having good post-development resolution and adhesion, excellent in developer dispersion stability and free of agglomerates, and light having a photopolymerizable resin layer containing the composition. It is an object of the present invention to provide a polymerizable resin laminate, and to provide a method for forming a resist pattern using the laminate and a method for producing a conductor pattern and the like.

As a result of studying to solve the above problems, by using a specific photopolymerizable resin composition, the post-development resolution and adhesion are good, the developer dispersion stability is excellent, and no agglomerates are generated. The present inventors have found that a good conductor pattern can be formed, and have reached the present invention.
That is, the present invention is as follows.
1. (A) The carboxyl group content is 100 to 600 in terms of acid equivalent, the monomer represented by the following general formula (I) is contained as a copolymerization component in an amount of 50% by mass or more, and the weight average molecular weight is 5,000 to 500,000. 10 to 90% by mass of a certain binder resin with respect to the total of the photopolymerizable resin composition, (b) 5 to 70% by mass of the photopolymerizable unsaturated compound with respect to the total of the photopolymerizable resin composition, c) A photopolymerizable resin composition comprising 0.01 to 20% by mass of a photopolymerization initiator based on the total amount of the photopolymerizable resin composition, the (b) photopolymerizable unsaturated compound Comprising at least one compound selected from the group represented by the following general formula (II) and at least one compound selected from the group represented by the following general formula (III) Polymerizable resin composition.

(R ¹ is a hydrogen atom or a methyl group, R ² represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group, a carboxyl group or a haloalkyl group.)

(In the formula, R ³ and R ⁴ are a hydrogen atom or a methyl group, and these may be the same or different. A ¹ and B ¹ are an ethylene group or a propylene group, and are the same respectively. Or may be different, in which case the repeating unit of-(A ¹ -O)-and-(B ¹ -O)-may be a block structure or a random structure, and-(A ^1- Any of the order of O)-and-(B ¹ -O)-may be on the ester side, and m1, m2, m3, and m4 are each independently 0 or a positive integer, Is 2-40.)

^{(Wherein, R 5, R 6, R} 7 is a hydrogen atom or a methyl group, they may be different even in the same, A ² and B ² is an ethylene or propylene group, each of the same If there are or different, are different in, - ^(a 2 -O) - and - ^(B 2 -O) - repeating units may be a random structure in the block structure, - ^{(a 2} - O) - and - ^(B 2 -O) - sequence of any may be an ester side .M5, m6, and m7 each independently an integer of 0 or more, m8, m9, and m10 are each independently 1 to an integer of 1 or more, and the total of these is 3 to 7.
2. (B) The photopolymerizable unsaturated compound contains at least one compound selected from the group represented by the following general formula (IV): The photopolymerizable resin composition as described.

(Where R ⁸ is a diisocyanate residue having 4 to 12 carbon atoms, R ⁹ and R ¹⁰ are hydrogen or a methyl group, and A ³ and B ³ are an ethylene group or a propylene group, If different and, also be different, - ^(a 3 -O) - and - ^(B 3 -O) - repeating units may be a random structure in the block structure, - ^(a 3 -O) - and - ^(B 3 -O) -. the order of the one is or may be an ester side, m11, m12 are each independently 0 to 15 integer, m13, m14 are each independently an integer of 1 to 15 Indicates.

3. 2. In the compound represented by the above general formula (IV), B ³ is a propylene group. The photopolymerizable resin composition as described.
4). Above 1. ~ 3. A photopolymerizable resin laminate obtained by laminating the photopolymerizable resin composition according to any one of the above on a support.
5). Above 1. ~ 3. A method for forming a resist pattern comprising the steps of: laminating a photopolymerizable resin composition according to any one of the above on a substrate, exposing and developing.
6). 5. above. A method for manufacturing a circuit board, comprising a step of etching or plating a substrate on which a resist pattern is formed by the method described above.
7). Using a metal plate as the substrate, the above 4. A method for producing a lead frame, comprising: etching a substrate on which a resist pattern is formed by the method described in 1), and peeling the resist pattern.
8). As a substrate, a wafer on which circuit formation as an LSI has been completed is used. A method for producing a semiconductor package, comprising: plating a substrate on which a resist pattern has been formed by the method described in 1) and peeling the resist pattern.

  According to the present invention, the post-development resolution and adhesion are excellent, and the dispersion stability of the developer is excellent in the development process. Therefore, the light is suitable for forming a good conductor pattern without generating aggregates. A polymerizable resin composition and a photopolymerizable resin laminate having a photopolymerizable resin layer made of the composition can be provided.

Hereinafter, the present invention will be specifically described.
The resin for binder (a) used in the present invention has a carboxyl group content of 100 to 600, more preferably 250 to 450, as an acid equivalent. An acid equivalent means the mass of the linear polymer which has a 1 equivalent carboxyl group in it. The carboxyl group in the binder resin is necessary for giving the photopolymerizable resin layer developability and releasability with respect to an alkaline aqueous solution. The acid equivalent is preferably 100 or more from the viewpoint of development resistance, resolution, and adhesion, and is preferably 600 or less from the viewpoint of developability and peelability. The acid equivalent is measured by a potentiometric titration method using a Hiranuma automatic titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd., and using a 0.1 mol / L sodium hydroxide aqueous solution.

The (a) binder resin used in the present invention is a binder resin having a weight average molecular weight of 5,000 to 500,000, and the weight average molecular weight of the binder resin is preferably 500,000 or less from the viewpoint of resolution. Edge fuse In view of the above, 5000 or more is preferable. In order to better exhibit the effects of the present invention, the weight average molecular weight of the binder resin is more preferably 5,000 to 200,000, still more preferably 5,000 to 100,000. The weight average molecular weight in this case is gel permeation chromatography (GPC) manufactured by JASCO Corporation (pump: GullIver, PU-1580 type, column: Shodex (trademark) (KF-807, manufactured by Showa Denko KK). KF-806M, KF-806M, KF-802.5) in series, moving bed solvent: tetrahydrofuran, polystyrene standard sample (use of calibration curve by Shodex STANDARD SM-105 Polystyrene manufactured by Showa Denko KK) weight average molecular weight It is calculated as (polystyrene conversion). The binder resin has a degree of dispersion (sometimes referred to as molecular weight distribution) of about 1 to 6, preferably 1 to 4. The degree of dispersion is represented by the ratio between the weight average molecular weight and the number average molecular weight of the following formula.
(Dispersity) = (weight average molecular weight) / (number average molecular weight)
The (a) binder resin used in the present invention is characterized in that it contains 50% by mass or more of a monomer represented by the following general formula (I) as a copolymerization component. (A) The resin for binder contains 50% by mass or more of the monomer represented by the following general formula (I) as a copolymerization component, so that it has excellent resolution after development and 80% by mass from the viewpoint of developability. It is preferable to contain below.

(R ¹ represents a hydrogen atom or a methyl group, and R ² represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group, a carboxyl group, or a haloalkyl group.)
(A) In addition to the monomer represented by the general formula (I), the binder resin is obtained by copolymerizing at least one monomer from the following first monomers. The content of the first monomer is determined by the acid equivalent. Further, the following second monomer may be copolymerized as necessary.
The first monomer is a carboxylic acid or acid anhydride having one polymerizable unsaturated group in the molecule. Examples include (meth) acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester, and the like.

  The second monomer is a non-acidic compound having one polymerizable unsaturated group in the molecule. The compound is selected so as to maintain various properties such as developability of the photopolymerizable resin layer, resistance to etching and plating, and flexibility of the cured film. Examples of the compound include methyl (meth) acrylate, ethyl (meth) acrylate, alkyl (meth) acrylate such as butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, Aryl (meth) acrylates such as (meth) acrylonitrile, furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, cresyl (meth) acrylate, naphthyl (meth) acrylate An aromatic ring of a benzyl (meth) acrylate such as a vinyl compound having a phenyl group (for example, styrene), methoxybenzyl (meth) acrylate or chlorobenzyl (meth) acrylate. · The group, a halogen, an alkyl group can be used compounds obtained by substituting.

(A) The binder resin is a mixture of the monomer represented by the general formula (I), the first monomer, and, if necessary, the second monomer, acetone, methyl ethyl ketone, Alternatively, it is preferable to carry out the synthesis by adding an appropriate amount of a radical polymerization initiator such as benzoyl peroxide or azoisobutyronitrile to a solution diluted with a solvent such as isopropanol and stirring with heating. In some cases, the synthesis is performed while a part of the mixture is dropped into the reaction solution. After completion of the reaction, a solvent may be further added to adjust to a desired concentration. As synthesis means, bulk polymerization, suspension polymerization, or emulsion polymerization may be used in addition to solution polymerization.
(A) The ratio with respect to the sum total of the photopolymerizable resin composition of resin for binders is the range of 10-90 mass%, Preferably it is 30-70 mass%. The resist pattern formed by exposure and development is preferably 20% by mass or more and 90% by mass or less from the viewpoint that the resist pattern has sufficient resistance as a resist, for example, tenting, etching, and various plating processes. Moreover, in the photopolymerizable resin composition of this invention, you may contain resin for binders other than the resin for binders which contains the monomer represented by the said general formula (I) as a copolymerization component.

  As the photopolymerizable unsaturated compound (b) used in the present invention, at least one compound selected from the group represented by the following general formula (II) and a group represented by the following general formula (III) It is characterized by containing at least one compound selected, and preferably contains at least one compound selected from the group represented by the following general formula (IV) from the viewpoint of tenting properties. By containing at least one compound selected from the group represented by the general formula (II) and at least one compound selected from the group represented by the following general formula (III), At least one compound selected from the group represented by the formula (II) is contained in an amount of 30% by mass to 90% by mass with respect to 100% by mass of the photopolymerizable unsaturated compound (b) from the viewpoint of resolution. It is preferable. In addition, at least one compound selected from the group represented by the following general formula (III) is from 5% by mass to 40% by mass with respect to 100% by mass of (b) the photopolymerizable unsaturated compound from the viewpoint of resolution. % Or less is preferable. From the viewpoint of tenting properties, the photopolymerizable unsaturated compound (b) used in the present invention contains at least one compound selected from the group represented by the following general formula (IV). Preferably, (b) 5 mass% or more and 70 mass% or less are contained with respect to 100 mass% of photopolymerizable unsaturated compounds.

(In the formula, R ³ and R ⁴ are a hydrogen atom or a methyl group, and these may be the same or different. A ¹ and B ¹ are an ethylene group or a propylene group, and are the same respectively. Or may be different, in which case the repeating unit of-(A ¹ -O)-and-(B ¹ -O)-may be a block structure or a random structure, and-(A ^1- Any of the order of O)-and-(B ¹ -O)-may be on the ester side, and m1, m2, m3, and m4 are each independently 0 or a positive integer, Is 2-40.)

(In the formula, R ⁵ , R ⁶ and R ⁷ are a hydrogen atom or a methyl group, and these may be the same or different, and A ² and B ² are an ethylene group or a propylene group, respectively. If there are or different, are different in, - ^(a 2 -O) - and - ^(B 2 -O) - repeating units may be a random structure in the block structure, - ^{(a 2} - Any of the order of O)-and-(B ² -O)-may be on the ester side, m5, m6 and m7 are each independently an integer of 0 or more, and m8, m9 and m10 are each independently. 1 is an integer of 1 or more, and the total of these is 3 to 7.)

(Where R ⁸ is a diisocyanate residue having 4 to 12 carbon atoms, R ⁹ and R ¹⁰ are hydrogen or a methyl group, and A ³ and B ³ are an ethylene group or a propylene group, The repeating units of-(A ³ -O)-and-(B ³ -O)-may have a block structure or a random structure, and-(A ³ -O)- and - ^(B 3 -O) -. the order of the one is or may be an ester side, m11, m12 are each independently 0 to 15 integer, m13, m14 are each independently an integer of 1 to 15 Is shown.)

  Specific examples of at least one compound selected from the group represented by the general formula (II) include 2,2-bis {(4-acryloxypolyethyleneoxy) phenyl} propane, 2,2-bis {(4 -Methacryloxypolyethyleneoxy) phenyl} propane, 2,2-bis {(4-acryloxypolypropyleneoxy) phenyl} propane, 2,2-bis {(4-methacryloxypolypropyleneoxy) phenyl} propane and the like. The polyethyleneoxy group of the compound is a group consisting of a monoethyleneoxy group, a diethyleneoxy group, a triethyleneoxy group, a tetraethyleneoxy group, a pentaethyleneoxy group, a hexaethyleneoxy group, a heptaethyleneoxy group, and an octaethyleneoxy group. A compound having any group selected from the group consisting of bisphenol A and a diglycolate of polyethylene glycol in which 2 moles of ethylene oxide is added to both ends of bisphenol A (Shin Nakamura Chemical Co., Ltd.) is preferable. NK ester BPE-200 manufactured by Kogyo Co., Ltd., and dimethacrylate of polyethylene glycol (NK ester BPE-500 manufactured by Shin-Nakamura Chemical Co., Ltd.) and bisphenol A each having an average of 5 moles of ethylene oxide added to both ends of bisphenol A On both ends There are dimethacrylate polyalkylene glycols respectively obtained by adding propylene oxide by an average of 2 moles of ethylene oxide by an average of 6 moles.

Specific examples of at least one compound selected from the group represented by the above general formula (III) include, for example, triacrylate obtained by adding an average of 3 moles of ethylene oxide to trimethylolpropane (manufactured by Shin-Nakamura Chemical Co., Ltd.). A-TMPT-3EO).
Specific examples of at least one compound selected from the group represented by the general formula (IV) include, for example, hexamethylene diisocyanate, tolylene diisocyanate, or 2,2,4-trimethylhexamethylene diisocyanate. And a urethane compound obtained by a reaction of a diisocyanate compound such as a compound having a hydroxyl group and a (meth) acryl group in one molecule (such as 2-hydroxypropyl acrylate and oligopropylene glycol monomethacrylate). Specifically, there is a reaction product of hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (manufactured by NOF Corporation, Bremma-PP1000). Here, as at least one compound selected from the group represented by (IV), it is preferable from the viewpoint of tenting properties that B ³ is a propylene group. Here, the diisocyanate residue includes a urethane bond derived from a diisocyanate compound as a raw material.

  The photopolymerizable resin composition of the present invention includes (b) a photopolymerizable unsaturated compound, photopolymerization represented by the general formula (II), the general formula (III), and the general formula (IV). Other than the possible monomers, the compounds shown below can be used. For example, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 2-di (p -Hydroxyphenyl) propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyoxypropyltrimethylolpropane tri (meth) acrylate, polyoxyethyltrimethylolpropane triacrylate, penta Erythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane triglycidyl ether tri (meth) acrylate, bisphenol A diglycol Dilether-terdi (meth) acrylate, β-hydroxypropyl-β ′-(acryloyloxy) propyl phthalate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolyalkylene glycol (meth) Acrylate, polypropylene glycol mono (meth) acrylate, 2,2-bis {(4- (meth) acryloxypolyethoxy) cyclohexyl} propane, polypropylene glycol added with propylene oxide and polyalkylene glycol with ethylene oxide added at both ends And dimethacrylate.

  The ratio of the (b) photopolymerizable unsaturated compound used in the present invention to the total photopolymerizable resin composition is in the range of 5 to 70% by mass, preferably 10 to 60% by mass. 5 mass% or more is preferable from a viewpoint of improving sensitivity, resolution, and adhesiveness, and 70 mass% or less is preferable from the viewpoint of suppressing the peeling delay of the cold flow and the cured resist.

  In the photopolymerizable resin composition of the present invention, generally known (c) photopolymerization initiators can be used, and 2,4,5-tria is used from the viewpoints of sensitivity, resolution, and adhesion. A system in which a reel imidazole dimer and p-aminophenyl ketone are used in combination is preferred. Examples of the 2,4,5-triarylimidazole dimer include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis. -(M-methoxyphenyl) imidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, etc., in particular, 2- (o-chlorophenyl)- 4,5-diphenylimidazole dimer is preferred, and examples of p-aminophenyl ketone include p-aminobenzophenone, p-butylaminoacetophenone, p-dimethylaminoacetophenone, p-dimethylaminobenzophenone, p, p '-Bis (ethylamino) benzophenone, p, p'-bis (dimethylamino) benzophenone [Michler's ketone], p, p'-bi (Diethylamino) benzophenone, p, p'-bis (dibutylamino) benzophenone, and the like.

A combination with a pyrazoline compound such as 1-phenyl-3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline is also a preferred embodiment.
In addition to the compounds shown above, other photopolymerization initiators can be used in combination. Here, the photopolymerization initiator is a compound that is activated by various actinic rays such as ultraviolet rays and starts polymerization.
Other photopolymerization initiators include, for example, quinones such as 2-ethylanthraquinone and 2-tert-butylanthraquinone, aromatic ketones such as benzophenone, benzoin ethers such as benzoin, benzoin methyl ether and benzoin ethyl ether, Examples include acridine compounds such as 9-phenylacridine, benzyldimethylketal, and benzyldiethylketal.

Further, for example, there are combinations of thioxanthones such as thioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and tertiary amine compounds such as dimethylaminobenzoic acid alkyl ester compounds.
Further, there are oxime esters such as 1-phenyl-1,2-propanedione-2-O-benzoyloxime and 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime. Further, N-aryl-α-amino acid compounds can also be used, and among these, N-phenylglycine is particularly preferable.

The ratio of the photopolymerization initiator (c) used in the present invention to the total of the photopolymerizable resin composition is in the range of 0.01 to 20% by mass, more preferably 0.05 to 10% by mass. . From the viewpoint of obtaining sufficient sensitivity, 0.01 mass% or more is preferable, and from the viewpoint of sufficiently transmitting light to the bottom surface of the resist and obtaining good high resolution, 20 mass% or less is preferable.
The photopolymerizable resin composition of the present invention may contain coloring substances such as dyes and pigments. Examples of the coloring substance used include fuchsin, phthalocyanine green, olamine base, chalcoxide green S, paramadienta, crystal violet, methyl orange, Nile Bull-2B, Victoria Bull, Malachite Green (Hodogaya Chemical ( Eisen (registered trademark) MALACHITE GREEN), Basic Bull-20, Diamond Green (Hozengaya Chemical Co., Ltd. Eisen (registered trademark) DIAMOND GREEN GH), and the like.

  The photopolymerizable resin composition in the present invention may contain a coloring dye that develops color when irradiated with light. Examples of the coloring dye used include a combination of a leuco dye or a fluorane dye and a halogen compound. Examples of the leuco dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green], and the like. .

  Halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris (2,3 -Dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane, triazine compounds and the like. Examples of the triazine compound include 2,4,6-tris (trichloromethyl) -s-triazine and 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine.

Among such coloring dyes, a combination of tribromomethylphenylsulfone and a leuco dye or a combination of a triazine compound and a leuco dye is useful.
The content in the case of containing a coloring substance and a color former is preferably 0.01 to 10% by mass in the photopolymerizable resin composition. It is preferably 0.01% by mass or more from the viewpoint of recognizing sufficient colorability (coloring property), 10% by mass or less from the viewpoint of maintaining the contrast between the exposed part and the unexposed part and maintaining storage stability.

In order to improve the thermal stability and storage stability of the photopolymerizable resin composition in the present invention, it is preferable that the photopolymerizable resin composition contains the following additives. Examples of such additives include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2′- Methylene bis (4-ethyl-6-tert-butylphenol),
2,2′-methylenebis (4-methyl-6-tert-butylphenol), diphenylnitrosamine and the like can be mentioned. Further, as stabilizers, a compound in which propylene oxide is further added to both sides of polypropylene glycol in which an average of 1 mol of propylene oxide is added to both sides of bisphenol A, benzotriazole, carboxybenzotriazole, 1- (2-dialkylamino) carboxybenzo There is triazole, pentaerythritol 3,5-di-t-butyl-4-hydroxyphenylpropionic acid tetraester.

The total amount of the additives is preferably 0.01 to 3% by mass, more preferably 0.05 to 1% by mass. 0.01 mass% or more is preferable from a viewpoint of providing storage stability to a photopolymerizable resin composition, and 3 mass% or less is more preferable from a viewpoint of maintaining a sensitivity.
Furthermore, you may make the photopolymerizable resin composition of this invention contain a plasticizer etc. as needed. Examples of the plasticizer include phthalic acid esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, acetyl triethyl citrate, and acetyl tricitrate tri-n-propyl. Acetyl citrate tri-n-butyl, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ether, polypropylene glycol alkyl ether, and the like.

  As content in the case of containing a plasticizer etc., it is preferable to contain 5-50 mass% in a photopolymerizable resin composition, More preferably, it is 5-30 mass%. 5 mass% or more is preferable from a viewpoint of suppressing the delay of image development time or providing a softness | flexibility to a cured film, and 50 mass% or less is preferable from a viewpoint of suppressing insufficient hardening and cold flow.

<Photopolymerizable resin laminate>
The photopolymerizable resin laminate of the present invention comprises a photopolymerizable resin layer and a support that supports the layer, and if necessary, has a protective layer on the surface opposite to the support of the photopolymerizable resin layer. May be. The support used here is preferably a transparent one that transmits light emitted from the exposure light source. Examples of such a support include polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film. , Polyacrylonitrile film, styrene copolymer film, polyamide film, cellulose derivative film and the like. These films can be stretched if necessary. The haze is preferably 5 or less. The thinner the film, the more advantageous in terms of image forming property and economic efficiency, but a film having a thickness of 10 to 30 μm is preferably used because of the necessity of maintaining the strength.

Further, an important characteristic of the protective layer used in the photopolymerizable resin laminate is that the protective layer is sufficiently smaller than the support and can be easily peeled with respect to the adhesion to the photopolymerizable resin layer. For example, a polyethylene film or a polypropylene film can be preferably used as the protective layer. Also, a film having excellent peelability disclosed in JP-A-59-202457 can be used.
The thickness of the protective layer is preferably 10 to 100 μm, and more preferably 10 to 50 μm.
The thickness of the photopolymerizable resin layer in the photopolymerizable resin laminate of the present invention varies depending on the use, but is preferably 3 to 100 μm, more preferably 3 to 50 μm. The thicker the film strength is.

A conventionally known method can be adopted as a method for producing a photopolymerizable resin laminate of the present invention by sequentially laminating a support, a photopolymerizable resin layer, and if necessary, a protective layer. For example, the photopolymerizable resin composition used for the photopolymerizable resin layer is mixed with a solvent for dissolving them to form a uniform solution, which is first coated on a support using a bar coater or roll coater and dried. The photopolymerizable resin layer made of the photopolymerizable resin composition is laminated on the support. Next, if necessary, a photopolymerizable resin laminate can be produced by laminating a protective layer on the photopolymerizable resin layer.
Examples of the solvent include ketones represented by methyl ethyl ketone (MEK), and alcohols represented by methanol, ethanol, and isopropanol. It is preferable to add to the photopolymerizable resin composition so that the viscosity of the solution of the photopolymerizable resin composition applied on the support is 500 to 4000 mPa at 25 ° C.

<Resist pattern formation method>
The resist pattern using the photopolymerizable resin laminate of the present invention can be formed by a process including a lamination process, an exposure process, and a development process. An example of a specific method is shown.
First, a lamination process is performed using a laminator. When the photopolymerizable resin laminate has a protective layer, the protective layer is peeled off, and then the photopolymerizable resin layer is heat-pressed and laminated on the substrate surface with a laminator. In this case, the photopolymerizable resin layer may be laminated only on one side of the substrate surface, or may be laminated on both sides. The heating temperature at this time is generally 40 to 160 ° C. Moreover, adhesion and chemical resistance are improved by performing the thermocompression bonding twice or more. At this time, for the crimping, a two-stage laminator having two rolls may be used, or it may be repeatedly crimped through the roll several times.

Next, an exposure process is performed using an exposure machine. If necessary, the support is peeled off and exposed to active light through a photomask. The exposure amount is determined from the light source illuminance and the exposure time. You may measure using a photometer.
In the exposure process, a maskless exposure method may be used. In maskless exposure, exposure is performed by directly drawing on a substrate without using a photomask. As the light source, a semiconductor laser having a wavelength of 350 to 410 nm, an ultrahigh pressure mercury lamp, or the like is used. The drawing pattern is controlled by a computer, and the exposure amount in this case is determined by the light source illuminance and the moving speed of the substrate.
Next, a developing process is performed using a developing device. After the exposure, if there is a support on the photopolymerizable resin layer, this is removed if necessary, and then the unexposed portion is developed and removed using a developer of an alkaline aqueous solution to obtain a resist image. An aqueous solution of Na ₂ CO ₃ , K ₂ CO ₃ or the like is used as the alkaline aqueous solution. These are selected according to the characteristics of the photopolymerizable resin layer, and a Na ₂ CO ₃ aqueous solution having a concentration of 0.2 to 2% by mass and 20 to 40 ° C. is generally used. A surface active agent, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution.

  Although a resist pattern is obtained by the above-mentioned process, a heating process at 100 to 300 ° C. can be further performed depending on the case. By carrying out this heating step, chemical resistance can be further improved. For heating, a heating furnace of a hot air, infrared ray, far infrared ray or the like is used.

<Conductor Pattern Manufacturing Method / Printed Wiring Board Manufacturing Method>
The method for producing a printed wiring board according to the present invention is performed through the following steps following the above-described resist pattern forming method using a copper clad laminate or a flexible substrate as a substrate. First, a conductor pattern is formed on the copper surface exposed by development using a known method such as an etching method or a plating method.
Thereafter, the resist pattern is peeled from the substrate with an aqueous solution having alkalinity stronger than that of the developer to obtain a desired printed wiring board. The alkaline aqueous solution for peeling (hereinafter also referred to as “peeling solution”) is not particularly limited, but an aqueous solution of NaOH or KOH at a concentration of 2 to 5% by mass, 40 to 70 ° C. is generally used. It is possible to add a small amount of a water-soluble solvent to the stripping solution.

<Lead frame manufacturing method>
The lead frame manufacturing method of the present invention is performed through the following steps following the above-described resist pattern forming method using a metal plate of copper, copper alloy, iron-based alloy or the like as a substrate.
First, a conductive pattern is formed by etching the substrate exposed by development. Thereafter, the resist pattern is peeled off by the same method as the above-described printed wiring board manufacturing method to obtain a desired lead frame.

<Semiconductor package manufacturing method>
The method for producing a semiconductor package of the present invention is performed by performing the following steps following the above-described resist pattern forming method using a wafer on which a circuit as an LSI has been formed as a substrate. A conductor pattern is formed by performing columnar plating such as copper or solder on the opening exposed by development. Thereafter, the resist pattern is peeled by the same method as the above-described printed wiring board manufacturing method, and the thin metal layer other than the columnar plating is removed by etching to obtain a desired semiconductor package.

<Manufacturing method of substrate having concave / convex pattern>
When the substrate is processed by the sandblasting method using the photopolymerizable resin laminate of the present invention as a dry film resist, the photopolymerizable resin laminate is laminated on the substrate by the same method as described above. Then, exposure and development are performed. Further, a blasting material is sprayed from the formed resist pattern to be cut to a desired depth, and a resin part remaining on the base material is removed from the base material with an alkaline stripping solution, etc. A fine pattern can be processed. The blasting material used for the above-mentioned sandblasting process may be a known material, for example, fine particles of about 2 to 100 μm such as SiC, SiO ₂ , Al ₂ O ₃ , CaCO ₃ , ZrO, glass, stainless steel and the like.
Hereinafter, examples of the embodiment of the present invention will be described in more detail by way of examples.

Below, the preparation method of the sample for evaluation of an Example and a comparative example, the evaluation method about the obtained sample, and an evaluation result are shown.
1. Production of Evaluation Samples Photopolymerizable resin laminates in Examples and Comparative Examples were produced as follows.
<Production of photopolymerizable resin laminate>
Prepare the compounds shown in Table 1, thoroughly stir and mix the photopolymerizable resin composition having the composition ratio shown in Table 2, and apply uniformly to the surface of a 20 μm-thick polyethylene terephthalate film as a support using a bar coater. And dried in a dryer at 95 ° C. for 2 minutes to form a photopolymerizable resin layer. The thickness of the photopolymerizable resin layer was 15 μm.
Next, a 25 μm thick polyethylene film was laminated as a protective layer on the surface of the photopolymerizable resin layer on which the polyethylene terephthalate film was not laminated to obtain a photopolymerizable resin laminate.

<Board surface preparation>
The following (1), (2) and (4) substrates for evaluation use a 1.6 mm thick copper clad laminate on which 35 μm rolled copper foil is laminated, and wet buffalo polishing of the surface (manufactured by 3M Co., Ltd., Scotch Bright) (Registered trademark) HD # 600, twice).
<Laminate>
Laminating at a roll temperature of 105 ° C with a hot roll laminator (Asahi Kasei Co., Ltd., AL-700) on a copper clad laminate that has been leveled and preheated to 60 ° C while peeling the polyethylene film of the photopolymerizable resin laminate. did. The air pressure was 0.35 MPa, and the laminating speed was 1.5 m / min.
<Exposure>
On the photopolymerizable resin layer, a mask film necessary for evaluation is placed on a polyethylene terephthalate film as a support, and an ultra-high pressure mercury lamp (OMW Seisakusho, HMW-801) is used to make a 21-step tablet made by Stöffer 6 steps. It exposed with the exposure amount used as.

<Development>
After the polyethylene terephthalate film is peeled off, a 1% by mass Na ₂ CO ₃ aqueous solution at 30 ° C. is sprayed for a predetermined time using an alkali developing machine (manufactured by Fuji Kiko Co., Ltd., a dry film developing machine) to unexpose the photopolymerizable resin layer. The portion was dissolved and removed in a time twice the minimum image time. At this time, the minimum development time was defined as the minimum time required for the photopolymerizable resin layer in the unexposed portion to be completely dissolved.
<Etching>
The developed substrate was etched with a salt copper etching apparatus (manufactured by Tokyo Chemical Industry Co., Ltd.) at 3 mol / l hydrochloric acid, 250 g / l cupric chloride at 50 ° C. for 1.3 times the minimum etching time. At this time, the time when the copper foil on the substrate was completely dissolved and removed was defined as the minimum etching time.
<Resist stripping>
The cured resist was peeled off by spraying a 3% by mass aqueous sodium hydroxide solution heated to 50 ° C. onto the evaluation substrate after development.

2. Evaluation Method (1) Resolution Evaluation A substrate for resolution evaluation that had passed 15 minutes after lamination was exposed with a line pattern in which the width of the exposed area and the unexposed area was 1: 1. Development was performed with a development time twice as long as the minimum development time, and the minimum mask width in which a cured resist line was normally formed was defined as a resolution value, and the resolution was ranked as follows.
A: Resolution value of 10 μm or less ○: Resolution value of more than 10 μm, 14 μm or less Δ: Resolution value of more than 14 μm, 18 μm or less ×: Resolution value of more than 18 μm

(2) Adhesion Evaluation The substrate for adhesion evaluation 15 minutes after lamination was exposed through a line pattern mask in which the width of the exposed part and the unexposed part was 1: 100. Development was performed with a development time twice as long as the minimum development time, and the minimum mask width in which the cured resist line was normally formed was defined as the adhesion value.
◎: Adhesion value is 10 μm or less ○: Adhesion value exceeds 10 μm, 14 μm or less Δ: Adhesion value exceeds 14 μm, 18 μm or less X: Adhesion value exceeds 18 μm

(3) Evaluation of aggregating property A photosensitive layer (resist layer) having a thickness of 40 μm and an area of 0.16 m ^{2 in} the photopolymerizable resin laminate is dissolved in 200 ml of a 1% by mass Na ₂ CO ₃ aqueous solution, and a circulation spray device. Was sprayed for 3 hours with a spray pressure of 0.1 MPa. Thereafter, the developer was allowed to stand for 1 day, and the generation of aggregates was observed. When a large amount of agglomerates are generated, powdery or oily substances are observed at the bottom and side surfaces of the spray device. In addition, aggregates may float in the developer. A composition having good developer cohesiveness does not generate these aggregates at all, or even if they are generated, they can be easily washed away with a small amount of water. The state of occurrence of aggregates was ranked by visual observation as follows.
A: No agglomerates are generated. O: There is no agglomerates at the bottom or side of the spray device, but a very small amount of agglomerates that can be visually confirmed are observed in the developer, but they are easily washed away when washed with water.
(Triangle | delta): The aggregate is floating in the bottom part or side surface part of a spray apparatus, and a developing solution. Even if it is washed with water, everything cannot be washed away.
X: Aggregates are observed in the entire spray apparatus, and aggregates are floating in the developer. It is impossible to wash away everything with water, and most of it remains.

(4) Tenting property A through hole with a radius of 6 mm exists at equal intervals (1008 holes). A photopolymerizable resin is laminated on a tenting evaluation substrate, and a 21-step tablet made by Stöffer has 6 steps by HMW-201KB. The entire film was exposed at an exposure amount, developed with a development time twice as long as the minimum development time, and further washed with water at a spray pressure of 0.3 MPa in a water-washing tank, and the film tear rate was measured. The following ranking was performed according to the film tear rate.
A: Film tear rate is less than 1%.
○: The film tearing rate is less than 1 to 5%.
Δ: Film tear rate is 5% or more.

  According to the present invention, it is suitable as an etching resist or a plating resist in the fields of production of printed wiring boards, flexible wiring boards, lead frames, semiconductor packages and the like, and precision metal processing.

Claims (8)

(A) The carboxyl group content is 100 to 600 in terms of acid equivalent, the monomer represented by the following general formula (I) is contained as a copolymerization component in an amount of 50% by mass or more, and the weight average molecular weight is 5,000 to 500,000. 10 to 90% by mass of a certain binder resin with respect to the total of the photopolymerizable resin composition, (b) 5 to 70% by mass of the photopolymerizable unsaturated compound with respect to the total of the photopolymerizable resin composition, c) A photopolymerizable resin composition comprising 0.01 to 20% by mass of a photopolymerization initiator based on the total amount of the photopolymerizable resin composition, the (b) photopolymerizable unsaturated compound Comprising at least one compound selected from the group represented by the following general formula (II) and at least one compound selected from the group represented by the following general formula (III) Polymerizable resin composition.

(R ¹ represents a hydrogen atom or a methyl group, and R ² represents a hydrogen atom, a halogen atom, a hydroxyl group, and an alkyl group, alkoxy group, carboxyl group, or haloalkyl group having 1 to 12 carbon atoms.)

(In the formula, R ³ and R ⁴ are a hydrogen atom or a methyl group, and these may be the same or different. A ¹ and B ¹ are an ethylene group or a propylene group, and are the same respectively. Or may be different, in which case the repeating unit of-(A ¹ -O)-and-(B ¹ -O)-may be a block structure or a random structure, and-(A ^1- Any of the order of O)-and-(B ¹ -O)-may be on the ester side, and m1, m2, m3, and m4 are each independently 0 or a positive integer, Is 2-40.)

(In the formula, R ⁵ , R ⁶ and R ⁷ are a hydrogen atom or a methyl group, and these may be the same or different, and A ² and B ² are an ethylene group or a propylene group, respectively. If there are or different, are different in, - ^(a 2 -O) - and - ^(B 2 -O) - repeating units may be a random structure in the block structure, - ^{(a 2} - Any of the order of O)-and-(B ² -O)-may be on the ester side, m5, m6 and m7 are each independently an integer of 0 or more, and m8, m9 and m10 are each independently. (It is an integer of 1 or more, and the total of these is 3 to 7.) (B) The photopolymerizable resin composition according to claim 1, wherein the photopolymerizable unsaturated compound contains at least one compound selected from the group represented by the following general formula (IV).

(Wherein R ⁸ is a diisocyanate residue having 4 to 12 carbon atoms, R ⁹ and R ¹⁰ are hydrogen or a methyl group, and A ³ and B ³ are an ethylene group or a propylene group, which are the same. and or different, if different, - ^(a 3 -O) - and - ^(B 3 -O) - repeating units may be a random structure in the block structure, - ^(a 3 -O) - and - ^(B 3 -O) -. the order of any can also be a pendant ester, m11, m12 is 1 to 15 each independently an integer of 0 to 15, m13, m14 each independently Indicates an integer.) The photopolymerizable resin composition according to claim 2, wherein B ³ is a propylene group in the compound represented by the general formula (IV). A photopolymerizable resin laminate comprising the photopolymerizable resin composition according to any one of claims 1 to 3 laminated on a support. A method for forming a resist pattern comprising the steps of laminating the photopolymerizable resin composition according to claim 1 on a substrate, exposing and developing. A method for manufacturing a circuit board, comprising a step of etching or plating a substrate on which a resist pattern is formed by the method according to claim 5.   A method of manufacturing a lead frame, comprising: using a metal plate as a substrate; etching a substrate on which a resist pattern is formed by the method according to claim 5; and peeling the resist pattern.   6. A method of manufacturing a semiconductor package, comprising using a wafer on which circuit formation as an LSI has been completed as a substrate, plating a substrate on which a resist pattern has been formed by the method according to claim 5, and peeling the resist pattern.