WO2003077035A1

WO2003077035A1 - Photosensitive resin composition and use thereof

Info

Publication number: WO2003077035A1
Application number: PCT/JP2003/002800
Authority: WO
Inventors: Hideki Matsuda
Original assignee: Asahi Kasei Kabushiki Kaisha
Priority date: 2002-03-12
Filing date: 2003-03-10
Publication date: 2003-09-18
Also published as: AU2003213432A1; JP3883540B2; JPWO2003077035A1; CN1643451A; CN1310088C

Abstract

A photosensitive resin composition which has high sensitivity while retaining properties such as suitability for tinting, resistance to plating, and removability; and a layered product. The photosensitive resin composition comprises (a) a carboxylated thermoplastic polymer, (b) an ethylenic addition-polymerizable monomer having a specific structure, (c) a photopolymerization initiator comprising a 2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer, and (d) a dye comprising Diamond Green. A layer of the composition is formed on a support layer. Also provided are a method of forming a resist pattern with the layered photosensitive-resin product and a process for producing a printed wiring board, lead frame, or semiconductor package.

Description

Description Photosensitive resin composition and its use

The present invention relates to a photosensitive resin composition and a laminate, a method for forming a resist pattern using the same, and a method for producing a printed wiring board, a lead frame, or a semiconductor package. Background art

Electronic devices such as personal computers and mobile devices use printed wiring boards for mounting components and semiconductors.

A so-called dry film resist (hereinafter abbreviated as DFR), which comprises a support, a photosensitive resin layer, and a protective layer, has conventionally been used as a resist for manufacturing these printed wiring boards and the like. DFR is generally prepared by laminating a photosensitive resin layer on a support and further laminating a protective layer on the photosensitive resin layer. At present, the photosensitive resin layer used here is generally of an aluminum-based development type using a weak alkaline aqueous solution as a developing solution.

As the photosensitive resin layer, a composition containing a thermoplastic polymer having a carboxyl group, an addition polymerizable monomer having at least one terminal ethylenically unsaturated group, and a photopolymerization initiator is generally used. Have been.

To create a printed wiring board using such a DFR, the protective layer is first peeled off, and then a DFR is laminated using a laminator or the like on a permanent circuit making board such as a copper-clad laminate or a flexiple board. Exposure is performed through a wiring pattern mask film or the like. Next, if necessary, the support is peeled off, and the unexposed portion of the photosensitive resin layer is dissolved or dispersed and removed with a developer to form a resist pattern on the substrate.

After the formation of a resist pattern, the process of forming circuits can be broadly classified into two methods. The first method is to etch away the copper surface of the copper-clad laminate, etc., which is not covered by the resist pattern, and then make the resist pattern part stronger than the developing solution. This is a method of removing with an alkaline aqueous solution. In the second method, a copper surface such as a copper-clad laminate not covered with the resist pattern is plated with copper, solder, nickel, tin, or the like, and then, similarly to the first method. This is a method of removing the resist pattern portion and etching the copper surface of the copper-clad laminate or the like that has appeared after the removal. For the etching, cupric chloride, ferric chloride, copper-ammonia complex solution and the like are used. The characteristics of the DFR used here require high resolution, high tenting characteristics, plating resistance, and good peelability from the viewpoint of productivity and yield.

Conventionally, the present inventor has used a monomer having a urethane structure having a specific structure to provide etching resistance, plating resistance, and tenting properties (development of post-exposure DFR for closing and protecting through holes, spraying of etching solution, etc.). (Durability against pressure) and the like have been found to be extremely improved (see JP-A-63-184744). On the other hand, the present inventor has found that the use of a monofunctional monomer having a specific structure improves the fixation resistance and the releasability (see JP-A-6-161103). ).

However, these conventional DFRs have been desired to be further improved in terms of sensitivity, angular resolution, or tenting.

An object of the present invention is to provide a photosensitive resin composition and a laminate having high sensitivity while maintaining characteristics such as tenting properties, plating resistance, and peeling properties by using a plurality of monomers having a specific structure in combination. Another object of the present invention is to provide a method for forming a resist pattern using the photosensitive resin laminate, and a method for manufacturing a printed wiring board, a lead frame or a semiconductor package. Disclosure of the invention

That is, the present application provides the following inventions.

(1) (a) a thermoplastic polymer having a hydroxyl group;

(b) a compound represented by the following general formula 1, a compound represented by the following general formula 2, and an ethylenically unsaturated addition-polymerizable monomer containing a compound represented by the following general formula 3; (General formula 1)

R R

CH ₂ = CCR ^ -0-CNWNCR ^o -0-CC = CH.

O O H H O O

[Where W is a divalent alkyl group having 2 to 20 carbon atoms, and R ¹ and R ⁴ are hydrogen or a methyl group. R ² and R ³ are residues represented by the following formula (a)]

Equation (a)

CH ₃₀ O— CH ₂ — CH

[Where m is an integer from 2 to 25, n is an integer from 0 to 15 and these groups may be in random or block form. ] (General formula 2)

R ⁶

R ⁵ O-C- C = CH ₂

o [where, R. Is an alkyl group having 1 to 20 carbon atoms, R ⁶ is hydrogen or a methyl group, p is an integer from 0 to 20, q is an integer from 0 to 20, and the sum of P and q Is an integer from 2 to 20, and these groups may be in the form of a block or in a random form. ]

(General formula 3)

8 R ⁹

CH ₂ = C— CO— (C ₂ H ₄ 0) _r (C ₃ H ₆ 0) _s (C ₂ H ₄₀ ) _t — C_C = CH ₂

II II

oo [Where R ⁸ and R ⁹ are hydrogen or a methyl group, which may be the same or different, s is an integer of 320, and r and t are integers of 110 It is. ]

(c) a photopolymerization initiator comprising 2- (o-chlorophenyl) 145-diphenylimidazolyl dimer; and

(d) a dye containing a compound represented by the following formula 4,

(Equation 4)

A photosensitive resin composition containing

(2) 'A photosensitive resin laminate comprising a support and a layer of the photosensitive resin composition according to (1) above.

(3) Laminating the photosensitive resin laminate according to (2) above on the surface of a metal plate or a metal-coated insulating plate, exposing it to ultraviolet light, and removing the unexposed portion by development to remove the resist pattern. Forming method.

(4) The photosensitive resin laminate according to (2) is laminated on a circuit-forming substrate so that the photosensitive resin composition layer is in close contact with the circuit-forming substrate;

Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

Unexposed areas are removed by development to form a cured resist pattern; and then etched or plated,

A method for manufacturing a printed wiring board including steps.

(5) The photosensitive resin laminate according to (2) is coated on a circuit-forming substrate with a photosensitive resin composition. Laminated so that the layers of the object are in close contact;

Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

Unexposed areas are removed by development to form a cured resist pattern; and then etched;

A method for manufacturing a lead frame including steps.

(6) The photosensitive resin laminate according to (2) is laminated on a circuit-forming substrate so that a layer of the photosensitive resin composition is in close contact with the circuit-forming substrate;

Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

A method of manufacturing a semiconductor package including steps. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

As the thermoplastic polymer having a carboxyl group as the component (a) used in the present invention, at least one first monomer selected from polymerizable unsaturated carboxylic acids, alkyl (meth) acrylate, Hydroxyalkyl (meth) acrylate, (meth) acrylamide and a compound in which hydrogen on nitrogen is substituted by an alkyl or alkoxy group, styrene and styrene derivatives, (meth) atalylonitrile, and (meth) Examples include compounds obtained by vinyl copolymerizing at least one second monomer selected from glycidyl acrylate.

Specific examples of the first monomer used in the production of a thermoplastic polymer having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, cinnamate, crotonic acid, itaconic acid, and maleic acid semi-acid. Ester and the like may be mentioned, and each may be used alone or in combination of two or more.

The proportion of the first monomer in the thermoplastic polymer having a carboxyl group is from 15% by weight to 40% by weight, preferably from 20% by weight to 35% by weight. If the proportion is less than 15% by weight, development with an aqueous alkali solution becomes difficult. On the other hand, if the proportion exceeds 40% by weight, it becomes insoluble in the solvent during the polymerization, making synthesis difficult. It becomes difficult.

The second monomer used in the production of a thermoplastic polymer having a propyloxyl group includes methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and cyclohexanol (meta). Acrylate, n-butynole (meta) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropynole (meth) acrylate, 4 -Hydroxybutynole (meta) acrylate, polyethylene glycol mono (meta) acrylate, polypropylene glycol mono (meta) acrylate, (meta) acrylamide, N-methylol acrylamide, N-butoxymethylacrylinoleami Styrene, ρ-methylstyrene, p-chlorostyrene, ) § Tarironitoriru, include (meth) Atariru glycidyl etc., may be used alone or used in combination of two or more kinds.

The proportion of the second monomer in the thermoplastic polymer having a carboxyl group is from 60% by weight to 85% by weight, preferably from 65% by weight to 80% by weight. The ratio of the second monomer is automatically determined by the ratio of the first monomer, but if the ratio is less than 60% by weight, the flexibility of the cured film deteriorates. On the other hand, if the proportion exceeds 85% by weight, the developing time is undesirably long.

The weight average molecular weight of the thermoplastic polymer having a carboxyl group is in the range of 20,000 to 300,000, and preferably 30,000 to 150,000. The weight average molecular weight in this case is the weight average molecular weight measured by gel permeation chromatography (GPC) using a calibration curve of standard polystyrene.

If the weight average molecular weight is less than 20,000, the strength of the cured film will be low. On the other hand, when the weight average molecular weight exceeds 300,000, the viscosity of the photosensitive resin composition becomes high and the applicability of the photosensitive resin composition decreases.

The thermoplastic polymer having a carboxyl group is prepared by diluting a mixture of monomers with a solvent such as acetone, methyl ethyl ketone, or isopropanol, and then subjecting the solution to radical polymerization such as benzoyl peroxide and azoisobutyronitrile. It is preferable to synthesize by adding an appropriate amount of an initiator and stirring with heating. In some cases, synthesis is performed while a part of the mixture is dropped into the reaction solution. After the completion of the reaction, a solvent is further added to concentrate the product to a desired concentration. It may be adjusted every time. As a synthesis means, bulk polymerization, suspension polymerization, and emulsion polymerization are used in addition to solution polymerization.

The content of the thermoplastic polymer having a carboxyl group is preferably in the range of 30% by weight or more and 75% by weight or less, more preferably 40% by weight or more and 65% by weight or less based on the total weight of the photosensitive resin composition. If this amount is less than 30% by weight, the dispersibility of the unexposed light-sensitive resin composition in an alkaline developer is reduced, and the development time is significantly increased. If the amount exceeds 75% by weight, the photo-curing of the photosensitive resin layer becomes insufficient, and the resistance as a resist decreases.

The above-mentioned thermoplastic polymers having a carboxyl group may be used alone or in combination of two or more.

Examples of the ethylenically unsaturated addition polymerizable monomer (b) used in the present invention include a compound represented by the following general formula 1, a compound represented by the following general formula 2, and a compound represented by the following general formula 3.

(General formula 1)

R R

CH ₂ = CCR -0-CNWNCR "-0-CC = CH;

O O H H O O

[Where W is a divalent alkyl group having 2 to 20 carbon atoms, and R ¹ and R ⁴ are hydrogen or a methyl group. RR ³ is a residue represented by the following formula (a)] Formula (a)

CH ₃

[Where m is an integer from 2 to 25, n is an integer from 0 to 15, and these groups may be in random or block form. ] (General formula 2)

IT CH ₂

o

[Where R ⁵ is an alkyl group having 1 to 20 carbon atoms, R ⁶ is hydrogen or a methyl group, p is an integer of 0 to 20, q is an integer of 0 to 20, and p The sum of and q is an integer from 2 to 20, and these groups can be in block or random form. ]

(General formula 3)

R R

CH ₂ = C-CO- (C 2H4O) _r (C ₃ H ₆ 0) _s (C2H4O) _t- C_C = CH:

O O

[Where R ^s and R ^J are hydrogen or a methyl group, which may be the same or different, s is an integer of 3 to 20, r and t are 1 to 10 It is an integer. ]

The compound of the above general formula 1 is a urethanated product of a disubstituted isocyanate compound and a hydroxy (meth) atalylate compound having an alkyloxide repeating unit. Here, W is a divalent alkyl group having 2 to 20 carbon atoms, and is hydrogen or a methyl group. R ² and R ³ are residues represented by the above formula (a), m is an integer from 2 to 25, n is an integer from 0 to 15, and these groups are random. It may be in the form of a block or a block.

Examples of the above-mentioned disubstituted isocyanate compounds include hexamethylene diisocyanate, tolylene diisocyanate, and isophorone diisocyanate. Hexamethylene diisocyanate is more preferable. Examples of the hydroxy (meth) acrylate compound having an alkyloxide repeating unit include, for example, Examples of the compound include hydroxypropyl (meth) acrylate and hydroxyethyl (meth) acrylate with alkylene oxide added thereto. Examples of the alkylene oxide to be added include propylene oxide and ethylene oxide, which may be used alone, two or more kinds may be used in a random form, or may be used in a block form. Absent. Preferable examples include compounds obtained by adding propylene oxide to 2-hydroxypropyl methacrylate, such as Plenmer PP 100 (manufactured by NOF Corporation).

The compound of the above general formula 2 is an esterified product of a monol obtained by adding ethylene oxide and / or Z or propylene oxide to an alkyl-substituted phenol and methacrylic acid or acrylic acid. Here, R "is an alkyl group having 1 to 20 carbon atoms, ^RD is hydrogen or a methyl group, p is an integer of 0 to 20, q is an integer of 0 to 20, and The sum of p and q is an integer from 2 to 20. When both ethylene oxide and propylene oxide are added to an alkyl-substituted phenol, they may be in the form of blocks or in a random form. It does not matter.

Among them, compounds in which R ⁵ is an alkyl group having 8 to 15 carbon atoms, p force S 0 to 5 and q force 5 to 12 are preferable. The compound of the above-mentioned general formula 3 is a compound which can be synthesized by a force of causing a (meth) acrylic acid to undergo an esterification reaction or a transesterification reaction with a polyol obtained by adding ethylene oxide to polypropylene oxide. Here, R ⁸ and R ⁹ are hydrogen or a methyl group, and the number s of repeating units of propylene oxide is 3 to 20 and preferably 8 to 15. The number of repeating units r and t of ethylene oxide is from 1 to 10, preferably from 2 to 5.

The component (b) used in the present invention may contain a compound other than the compounds of the above general formulas 1 to 3. Such compounds include, for example, 2-hydroxy-3-phenoxypropyl acrylate, phenoxytetraethylene glycol acrylate, α-hydroxypropyl mono ((attaliloyloxy) propyl phthalate) , 1,4-tetramethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexane diol (T) Atarilate, heptapropylene glycol di (meth) atarilate, glycerol (meth) atarilate, 2-di (p-hydroxyphenyl) propane di (meth) atarilate, glyceronoletri (meta) atarilate, trimethylol propanetri (Meth) acrylate, polyoxypropyltrimethylolpropanetri (meth) acrylate, polyoxyethyltrimethylolpropanetri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate , Trimethylolpropane triglycidyl ether tri (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, diaryl phthalate, polyethylene Glycol di (meth) acrylate, polypropylene glycol di (meth) atalylate, 4-nonolemanoleooctinolephenoxypentapropylene propylene glycol, bis (triethylene glycol methacrylate) nonapropylene dalicol, Bis (tetraethylene glycol methacrylate) polypropylene glycol, bis (triethylene glycol methacrylate) polypropylene glycol, bis (diethylene glycol acrylate) polypropylene glycol, 4-normal malonyl phenoxy heptaethylene glycol dipropylene glycol ) Atharylate, phenoxytetrapropylene glycol tetraethylene glycol (meth) acrylate, bisphenol A-based (meth) acrylic acid A compound containing an ethylene oxide chain in the molecule of a termonomer, a compound containing a propylene oxide chain in the molecule of a bisphenol A-based (meta) atalinoleate monomer, and a molecule of a bisphenol A-based (meth) acrylate monomer Examples thereof include compounds containing both an ethylene oxide chain and a propylene oxide chain.

The ratio (weight ⁰ ) of the compound of the above general formula 1 / the compound of the above general formula 2 to the compound of the above general formula 3 is preferably 10 to 80/10 to 80/10 to 80, preferably. Is from 15 to 7 ■ OZl 5 to 7 OZl 5 to 70.

The content of the ethylenically unsaturated addition polymerizable monomer (b) is preferably from 20% by weight to 65% by weight based on the total weight of the photosensitive resin composition. More preferably, the content is 30% by weight or more and 60% by weight or less. If the proportion is less than 20% by weight, the light-sensitive resin is not sufficiently cured, and the strength as a resist is insufficient. On the other hand, When the total amount exceeds 65% by weight, when the photosensitive resin laminate is stored in the form of a roll, the phenomenon that the photosensitive resin layer gradually protrudes from the end face, that is, the edge fusion deteriorates.

In the present invention, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer is used as the photopolymerization initiator of the component (c). This compound is known by the trivial name Rofinnimer.

In the present invention, other photopolymerization initiators can be used in combination. Examples of such photopolymerization initiators include, for example, benzyldimethyl ketal, benzyljetinole ketanore, benzinoresipropinoleketanore, benzinoresipheninoleketanore, benzozinmethinoleatenore, and benzoinechinore. Athenole, benzoinpropynoleatenole, benzoinpheninoleatenole, thioxanthone, 2,4-dimethinolethioxanthone, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, 4-isopropinolethioxanthone, 2 , 4 diisopropynolethioxanthone, 2 monofluorobenzene, 4 fluoroisoxanthone, 2 chlorothioxanthone, 4 monoclox thioxanthone, 1 chloro-4-propoxythioxanthone, benzophenone, 4, 4, one screw Aromatic ketones such as reamino) benzophenone [Michler's ketone], 4,4,1-bis (getinoleamino) benzophenone, 2,2-dimethoxy-12-phenylacetophenone; 2- (o-chlorophenyl) -4,5 —Bimidazole compounds such as diphenylimidazolyl dimer; ataridines such as 9-phenylacridine; α, α-dimethylmethoxyl-morpholino-methylthiopheneylacetophenone; 2,4,6-trimethylbenzoyl Ludiphenylphosphinoxide, phenylglycine, Ν-phenylglycine 1-phenylene 1,2-propanedione 2- 2-o-benzoinoleoxime, 2,3-dioxo-1 3-ethylphenylpropionate Oxime esters, such as 2-((o-benzoylcarponyl) -oxime; ρ-dimethylamino Kosan, .rho. Jechiruamino benzoic San及 Pi J) over Jie isopropyl § amino benzoic San及 Pico ester of these alcohols; and .rho. hydroxybenzoic acid ester is exemplified et be. Among them, especially 2- (0-chlorophenyl) _4,5-diphenylimidazolyl dimer and Michler's ketone or 4,4'-bis (getylamino) A combination of nzophenone is preferred.

The content of the photopolymerization initiator as the component (c) of the present invention is preferably 0.01% by mass or more and 20% by mass or less based on the total mass of the photosensitive resin composition. More preferably, the content is 1% by mass or more and 10% by mass or less. If the amount is less than 0.01% by mass, the sensitivity is not sufficient. On the other hand, if this amount is more than 20% by mass, the ultraviolet ray absorption rate becomes high, and the curing at the bottom of the photosensitive resin layer becomes insufficient.

The photosensitive resin composition of the present invention contains a compound represented by the following formula 4 as the component (d) dye.

(Equation 4)

This compound is classified as B a s i c in the C I (Color Index) classification.

A compound called Gle en 1 whose formal chemical name is bis (p-ethylaminophenyl) phenylmethylimsulfate.

Diamond Green (trade name), which is a kind of Basic Green 1, is sold as Aizen Diamond Green GH (product name, manufactured by Hodogaya Chemical Co., Ltd.). The amount of diamond green added is preferably from 0.01% by mass to less than 0.1% by mass, more preferably from 0.03% by mass to less than 0.07% by mass, based on the total mass of the photosensitive resin composition. If the amount is less than 0.01% by mass, the coloration after development is small, so that the inspection is difficult. If the amount exceeds 0.1% by mass, it is difficult to align with the pattern of the substrate when exposing with a mask, which is not preferable. In general, when a dye is added, the sensitivity tends to decrease. However, since the degree of diamond green is small, a desired sensitivity can be obtained with a smaller exposure dose. The photosensitive resin composition of the present invention may contain coloring substances other than diamond green, such as dyes and pigments. Such coloring substances include, for example, fuchsin, phthalocyanine green, auramine base, carboxide green S, paramagenta, crystal violet, methinole orange, nile venolay 2B, Victoria blue, malachite green, and pey Thick blue 20 and the like. In order to improve the thermal stability and storage stability of the photosensitive resin composition of the present invention, it is preferable to include a radical polymerization inhibitor. Examples of such radical polymerization inhibitors include, for example, p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, t-butylcatechol, cuprous chloride, 2,6-di-t-butyl-p-cresonol, Examples include 2,2, methylenebis (4-ethynole 6-t-butynolephenol) and 2,2 'methylenebis (4-methyl-6-t-butylphenol).

Further, the photosensitive resin composition of the present invention may contain a coloring dye which develops a color upon irradiation with light. As such a coloring dye, a combination of a leuco dye and a halogen compound is well known. Examples of leuco dyes include tris (4-dimethylamino-2-methylphenyl) methane [leucocrystal violet], tris (4-dimethylamino-12-methylphenyl) methane [leucomalachite green], and the like. On the other hand, examples of the halogen compound include amyl bromide, isoamyl bromide, isobutylene bromide, butylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tripromomethylphenylsulfone, carbon tetrabromide, and carbon tetrabromide. (2,3-dibromopropynole) phosphate, trichloroacetamide, iodideamyl, isoptyl iodide, 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane, hexachloroethane, etc. No.

Further, the photosensitive resin composition of the present invention may contain an additive such as a plasticizer, if necessary. Such additives include, for example, estanolates such as getyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, triptyl citrate, triethyl atenate, and triacetate citrate. Butyl, acetyl citrate tri-n-propyl, acetyl citrate tri-n-butyl, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ether, polypropylene glycol alkyl ether, and the like.

The thickness of the photosensitive resin layer in the photosensitive resin laminate of the present invention is preferably 1 ^ um or more and 150 m or less, more preferably 3 // m or more and 80 m or less, . The thickness of the photosensitive resin layer is preferably 1 μππ or more from the viewpoint of film-forming coatability, and is preferably 15 μππ or less from the viewpoint of the resolution and adhesion of the image after development.

The method for producing the photosensitive resin laminate of the present invention can be performed by a conventionally known method. For example, the photosensitive resin composition of the present invention is mixed with a solvent to form a uniform solution, and the solution is applied to a support using a bar coater or a roll coater and dried to form a uniform solution. To obtain a photosensitive resin laminate of the present invention in which a photosensitive resin layer is laminated.

The support used in the photosensitive resin laminate of the present invention is desirably a transparent substrate that transmits active light. For example, polyethylene terephthalate film, polyethylene naphthalate, polyvinyl alcohol film, polyvinyl chloride film, polyvinyl chloride copolymer film, polyvinyl chloride copolymer film, vinylidene vinyl 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.

The thickness of the support used in the photosensitive resin laminate of the present invention is preferably from 1 μππ to 40 μπι, and more preferably from 12 μππ to 30 μπι. The thickness of the support is preferably 10 m or more from the viewpoint of handling, and is preferably 40 μπι or less from the viewpoint of resolution.

Further, a protective layer may be laminated on the photosensitive resin of the photosensitive resin laminate of the present invention to produce a three-layer photosensitive resin laminate. In this case, the thickness of the protective layer is preferably from 15 μπι to 50 μπι, and more preferably from 25 m to 45 m. It is preferably 15 m or more from the viewpoint of the yield of the final product, and is preferably 5 O ^ um or less from the viewpoint of the production cost. Examples of the film used for the protective layer include a polyolefin film such as a polyethylene film and a polypropylene finolem, a polyestenorefinolem, and a polyester film whose releasability has been improved by silicone treatment or alkyd treatment. Particularly, a polyethylene film is preferable. Next, an example of a method for manufacturing a printed wiring board using the photosensitive resin laminate of the present invention will be described.

The printed wiring board is manufactured through the following steps.

(1) A lamination process in which a photosensitive resin laminate is adhered to a substrate such as a copper-clad laminate or a flexible substrate using a hot roll laminator while peeling off its protective layer.

(2) An exposure step in which a mask film having a desired wiring pattern is brought into close contact with a support and exposed using an active light source.

(3) A development step of dissolving or dispersing and removing the unexposed portion of the photosensitive resin layer using a developer after removing the support, and forming a resist pattern on the substrate.

(4) An etching process in which an etching solution is sprayed onto the formed resist pattern to etch the copper surface not covered by the resist pattern, or copper, solder, nickel, and nickel are applied to the copper surface not covered by the resist pattern. Plating process for plating tin etc.

(5) A stripping step of removing the resist pattern from the substrate using an alkali stripper. Examples of the actinic light source used in the above exposure step include a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an ultraviolet fluorescent lamp, a carbon arc lamp, a xenon lamp, and the like. In order to obtain a finer resist pattern, it is more preferable to use a parallel light source. In order to minimize the influence of dust / foreign matter, exposure (proximity exposure) may be performed with the photomask floating above the support by several tens / zm to several hundred / m.

Examples of the alkali developer used in the developing step include aqueous solutions of sodium carbonate, carbon dioxide lime, and the like. These alkaline aqueous solutions are selected according to the characteristics of the photosensitive resin layer, but are generally in the range of 0.51% to 3% ^ 1. A real aqueous solution is used.

The etching step is performed by a method suitable for the DFR to be used, such as acid etching or alkali etching.

The alkaline stripping solution used in the stripping step is generally an aqueous solution having a stronger strength than the aqueous solution used in the development, for example, 1 wt% or more and 5 wt% or less of sodium hydroxide or water. An aqueous solution of an oxidizing realm is used.

When a plating step is adopted, the copper surface that appears under the resist pattern may be etched after the resist pattern is stripped.

When a lead frame is manufactured using the photosensitive resin laminate of the present invention, instead of the copper-clad laminate or the flexible substrate described above, instead of the copper-clad laminate or the flexible substrate, a copper, copper alloy, iron-based alloy, or other metal plate is used. Laminate the photosensitive resin layer, perform exposure and development, and then etch. Finally, the cured resist is removed to obtain the desired lead frame. Furthermore, when manufacturing a semiconductor package, a photosensitive resin layer is laminated on a wafer for which circuit formation as an LSI has been completed, exposed and developed, and the opening is plated with copper or solder in a columnar shape. Next, the hardened resist is peeled off, and the thin metal layer other than the columnar plating is removed by etching to obtain a desired semiconductor package.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples. <Examples 1 to 7 and Comparative Examples 1 to 4>

The evaluation in Examples and Comparative Examples was performed by the following method.

1) Basic sample preparation conditions

(Preparation of photosensitive resin laminate)

A photosensitive resin composition having the composition shown in Table 1 was mixed, applied uniformly to a polyethylene terephthalate film having a thickness of 16 μπι using a bar coater, and dried in a dryer at 90 ° C for 2 minutes. After drying, a photosensitive resin layer was formed. The thickness of the photosensitive resin layer was 40 μπι. The component compositions in Table 1 represent parts by mass of the solid content.

A polyethylene film was laminated on the surface of the photosensitive resin layer on which the polyethylene terephthalate film was not laminated to obtain a photosensitive resin laminate. (Surface of board)

Jet scrub polishing of a copper-clad laminate (thickness: 1.6 mm) with a copper foil thickness of 35 // m using Sakurandam R # 220 abrasive (Nippon Carlit Co., Ltd.) 7

(Laminate)

While peeling off the polyethylene film of the photosensitive resin laminate, the pre-treated copper alloy substrate was subjected to a two-stage hot roll laminator (AL-700, manufactured by Asahi Kasei Corporation) at a former roll of 100 ° C and a latter roll of 100 ° C. Laminated. The laminator outlet pressure was 0.3 OMPa in air gauge and the laminating speed was 2. Om / min.

(Exposure)

The photosensitive resin layer, without a mask film, or through a mask film required in evaluation, ultra-high pressure mercury lamp (manufactured by ORC Manufacturing: HMW-80 1) were exposed at 6 0 mJ Z cm ² by.

(Development)

After peeling off the polyethylene terephthalate film, 30. The same 1% aqueous solution of sodium carbonate was sprayed for a predetermined time to dissolve and remove unexposed portions of the photosensitive resin layer. At this time, the minimum time required for completely dissolving the unexposed portion of the photosensitive resin was defined as the minimum development time, and the predetermined development time was 1.5 times as long.

2) Sensitivity measurement

27-step stepper bracket (Asahi Kasei Co., Ltd., optical density D = 0.50 to 1.80, density difference per step, as a photomask, the brightness of which changes from transparent to black in 27 steps) = 0.05), the number of step tablets corresponding to the position where the surface of the laminate was exposed after exposure and development was examined.

When the sensitivity is 12 steps or more, it is in a practically effective range. When the sensitivity is 11 steps or less, the exposure amount needs to be further increased due to lack of sensitivity, and productivity decreases.

3) Resolution test

The line space is 10/300 μπ for the substrate completed up to the laminating process, which is the basic condition for preparing the sample of 1). ~ 100/300 / m (in 5 μm increments) A photomask film was placed in a polyethylene terephthalate tallate film side as a support of the photosensitive resin laminate was exposed with an exposure amount of 6 OmjZcm ² through a photomask film, removing the polyethylene terephthalate film, LWT% 30 aqueous sodium carbonate solution. At C, the unexposed portion was removed by spraying at a spray pressure of 0.15 MPa for 80 seconds to obtain an image pattern. The resolution was defined as the minimum line width of the obtained image that was separated and did not flow (that is, there was no meandering of the image pattern, no part that was not in close contact with the substrate, etc.).

4) Peelability test

The substrate exposed and developed on a 3 cm X 5 cm area with an exposure of 60 mJ / cm ² is immersed in a 3 wt% sodium hydroxide aqueous solution maintained at 50 ° C, and the cured photosensitive resin layer is peeled from the substrate The time required for this was defined as the peeling time.

The case where the peeling time was 60 seconds or less was designated as Δ, and the case where the peeling time exceeded 60 seconds was designated as X.

5) Plating resistance test

In the exposure step 1) under the basic preparation conditions for the sample, the substrate that was exposed and developed using a circuit pattern-shaped photomask at an exposure amount of 6 OmjZ cm ² was pre-processed through the following steps.

a) Immerse in a 10 wt% aqueous solution of acidic cleaner FR (manufactured by Atotech) at 40 ° C for 4 minutes in a 20 wt% sulfuric acid solution.

b) Immerse in 200 g ZL ammonium persulfate aqueous solution for 1 minute at room temperature.

c) 10 wt at room temperature. /. Immerse in sulfuric acid aqueous solution for 2 minutes.

After the plating pretreatment, copper plating was performed for 30 minutes at room temperature at a current density of ^2.5 A / dm2 in a plating solution obtained by diluting Melcox's "copper sulfate sulfate" 3.6 times with 19 wt% sulfuric acid. I went. Furthermore, using a soldering liquid made of MacDermidne earth (tin / lead = 6/4 weight ratio), soldering was performed for 10 minutes at a current density of 2.OA / dm. 'According to JISK 5600-5-6 method, cellophane tape was applied to this substrate, and the plating resistance was evaluated as follows according to the state of the cured photosensitive resin layer after peeling off the bow I.

〇: No resist is attached to the tape, or the tape follows the pattern

Adheres linearly with a width of 100 μπι or less. Δ: The resist adheres to the tape with a width of 100 μιη or more along the pattern.

X: Almost the entire resist is peeled off and adheres to the tape.

6) Tenting test

Using a copper-clad laminate with 6 holes in diameter of about 100 mm, the photosensitive resin laminate was laminated sequentially on both sides of the substrate, and without passing through the pattern mask from both sides. Exposure was performed at an exposure amount where the number of step tablet steps described above was 13 steps. This was developed for 3 times the minimum developing time, and further washed with water at a spray pressure of 0.3 MPa for 1 minute. At least one side of the cured film in the hole was torn, and the number of holes was counted and ranked as follows.

〇: tear rate less than 10%

△: tear rate 10% or more and less than 30%

X: tear ratio of 30% or more Table 1 shows the results of Examples and Comparative Examples.

In addition, the composition (each component amount unit: part by weight) and the abbreviation of the support shown in Table 1 are shown below.

P—1: Methyl methacrylate Z-N-butyl methacrylate / acrylate (mass ratio is

6 5/2 5/1 0) has the composition, 3 0 mass ⁰ / o methyl E chill ketone solution of co-polymer having a weight average molecular weight is 1 20,000

M—1: Urethane compound of hexamethylene diisocyanate and oligopropylene glycolone monomethacrylate (Blenmer PP—100, manufactured by NOF Corporation)

M-2: bis (triethylene glycol methacrylate) nonapropylene glycol

M-3: 4-N-Normalonylphenoxypentaethylene glycol propylene glycol acrylate

M—4: Nonaethylene glycol diacrylate

M—5: phenoxytetraethylene glycol acrylate M—6: Avian-aged kissetinoletrimethylolpropane triatalylate

M-7: Hexamethylene diisocyanate and oligopropylene glycol ethylene glycol monomethacrylate (Nippon Yushi Co., Ltd. Blenmer 70 P '

EP-350 P) and urethane compounds

M-8: 4-Nonolemanolenoninolenophenoxyctaethylene glycolone monoacrylate

M—9: 4-Normal noninolephenoxyhexapropylene dariconolemonoacrylate

I_1: Michler's Ketone

I-2: 2- (o-chlorophenyl) -1,4,5-diphenylimidazolyl dimer D-1: Diamond green (Hodogaya Chemical Co., Ltd.)

D-2: Malachite green (Hodogaya Chemical Co., Ltd.)

D-3: Roy Kotristano Reno

table 1

Industrial applicability

The photosensitive resin composition according to the present invention has high sensitivity, excellent tenting properties, adhesion resistance, and peelability of a cured film, and is extremely useful for producing a printed wiring board, a lead frame or a semiconductor package.

Claims

The scope of the claims

1. (a) a thermoplastic polymer having a carboxyl group;

(b) an ethylenically unsaturated addition-polymerizable monomer containing a compound represented by the following general formula 1, a compound represented by the following general formula 2, and a compound represented by the following general formula 3; (general formula 1)

R ¹ R ⁴

CH ₃

[Where m is an integer from 2 to 25, n is an integer from 0 to 15 and these groups may be in random or block form. ]

(General formula 2)

C -H 2

[Where R ⁵ is an alkyl group having 1 to 20 carbon atoms, R ⁶ is hydrogen or a methyl group, p is an integer of 0 to 20, q is an integer of 0 to 20, and p The sum of and q is an integer from 2 to 20, and these groups can be in block or random form. ] (General formula 3)

R ⁸ R

CH ₂ = C— CO— (C 2H4 O) _R (C ₃ H ₆ 0) _S (C ₂ H ₄ 0) _T —C— C = CH ₂

O O

[Where R ⁸ and R ³ are hydrogen or a methyl group, which may be the same or different, s is an integer of 320, and r and t are integers of 110 It is. ]

(c) a photopolymerization initiator comprising 2- (o-chlorophenyl) 1-45-diphenylimidazolyl dimer; and

(d) a dye containing a compound represented by the following formula 4,

(Equation 4)

C ₂ H ₅ C ₂ H ₅

A photosensitive resin composition containing

2. A photosensitive resin comprising a support and a layer of the photosensitive resin composition according to claim 1 thereon.

3. A method for forming a resist pattern, comprising: laminating the photosensitive resin laminate according to claim 2 on a surface of a metal plate or a metal-coated insulating plate, exposing to ultraviolet light, and removing unexposed portions by development. .

4. Laminating the photosensitive resin laminate according to claim 2 on a circuit-forming substrate so that a layer of the photosensitive resin composition adheres tightly; Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

Unexposed areas are removed by development to form a hard resist pattern; and then etched or plated,

A method for manufacturing a printed wiring board including steps.

5. The photosensitive resin laminate according to claim 2 is laminated on a circuit-forming substrate so that a layer of the photosensitive resin composition adheres tightly;

Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

A method for manufacturing a lead frame including steps.

6. The photosensitive resin laminate according to claim 2 is laminated on a circuit-forming substrate so that a layer of the photosensitive resin composition is in close contact with the circuit-forming substrate;

Actinic rays are illuminated image-wise and the exposed areas are photo-cured;

A method of manufacturing a semiconductor package including steps.