JP2003228168A - Production of resist pattern, production of printed circuit board and production lead frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To method for producing a resist pattern for a photosensitive element which can be laminated in a good yield because of a reduced number of air voids that occur and is excellent in laminating property, shelf stability and working property, and to provide a method for producing a printed circuit board or lead frame having the resist pattern. <P>SOLUTION: This photosensitive element has a supporting film (A), a photosensitive resin composition layer (B) and a protective film (C). In the surface roughness of the protective film (C), the Ra of a face kept in contact with the photosensitive resin composition layer (B) is ≤0.15 μm and the Rmax is ≤1.5 μm. The Ra of the face which does not come in contact with the photosensitive resin composition layer (B) is 0.1 to 0.8 μm, and the Rmax is 1 to 5 μm. The photosensitive element, wherein the number of fisheyes with a diameter 80 μm or longer included in the protective film (C) is ≤5/m<SP>2</SP>, is laminated on a substrate for forming a circuit in such a way that the photosensitive resin composition layer (B) adheres closely to the substrate and the element is imagewise irradiated with active light. An exposed part is photoset and an unexposed part is removed by development. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist pattern manufacturing method, a printed wiring board manufacturing method, and a lead frame manufacturing method.

[0002]

2. Description of the Related Art In recent years, as semiconductor devices have become lighter, thinner, shorter, smaller, and manufactured in smaller quantities in other types, the lead frames and BGAs used for mounting IC chips on substrates have become more and more pins and narrower. A printed circuit board on which these semiconductor packages are mounted is also required to have a high density. A photosensitive element is generally used as the pattern forming resist. The photosensitive element has a sandwich structure in which a photosensitive resin composition is applied on a transparent support film, dried and laminated with a protective film.When the protective film is removed during lamination, the photosensitive resin composition layer is heated on the underlying metal. It is pressure-bonded and exposed through a mask film. Next, the support film is peeled off, and the unexposed portion is dissolved or dispersed by a developing solution to form a cured resist image on the substrate.

The process for forming a circuit is roughly divided into two methods, an etching method and a plating method. Here, the etching method is a method in which the metal surface not covered with the cured resist formed after development is removed by etching, and then the resist is peeled off. On the other hand, the plating method is a method in which a metal surface not covered with a cured resist formed after development is plated with copper, solder or the like, and then the resist is removed and the metal surface covered with the resist is etched. .

Further, with the increase in the number of pins in lead frames and BGAs, the reduction in size, and the increase in density of printed circuit boards on which these semiconductor packages are mounted, the photosensitive element tends to be thinned in terms of resolution, adhesion and cost. It is in. With the thinning of the photosensitive element, the embedding property (following property) with respect to the unevenness of the substrate surface is deteriorated, and the etching method causes chipping and disconnection of the circuit pattern, and the plating method causes short circuit. . Therefore, the photosensitive resin composition layer must flow due to heat and pressure in order to obtain the embedding property for the irregularities on the substrate surface during lamination.

On the other hand, a polyester film such as a polyethylene terephthalate film is used as the supporting film of the photosensitive element, and a polyolefin film such as a polyethylene film is used as the protective film. A polyolefin film usually used as a protective film is produced by melting raw materials by heat, kneading, extruding, biaxially stretching, casting or inflation method.

Generally, a protective film such as a polyolefin film contains a foreign substance called a fisheye 4, an undissolved substance and a thermally deteriorated substance as shown in FIG. The size of the fish eye is generally 10 μm to 1 mm in diameter and protrudes from the film surface at a height of 1 to 50 μm. The convex portion of the fish eye causes a depression in the photosensitive resin composition layer, and an air void 6 is generated on the substrate after lamination.
That is, when a photosensitive element composed of the support film 1, the photosensitive resin composition layer 2, and the protective film 3 having the fish eyes 4 is peeled off from the protective film 3 and laminated on the substrate 5, air voids 6 are generated.

The air voids 6 correlate with the film thickness of the photosensitive resin composition layer 2, and are more likely to occur as the film thickness of the photosensitive resin composition layer 2 becomes thinner, and a resist image is formed in the next step of exposure and development. At, a pattern defect and disconnection occur. This phenomenon causes chipping and disconnection of the circuit pattern in the etching method, and causes a short circuit in the plating method. Therefore, in order to prevent air entrapment in the photosensitive resin composition layer portion recessed by the fish eyes 4 during lamination, the photosensitive resin composition layer must flow by heat and pressure. As a measure against such a phenomenon, a method of lowering the viscosity of the photosensitive resin composition layer and improving the resin flow at the time of lamination can be considered, but in this case, the photosensitivity from the end of the photosensitive element called edge fusion is considered. There is a problem that exudation of the resin composition layer occurs and the laminating property deteriorates.

A vacuum laminator method is useful as described in JP-B-53-31670, JP-A-51-63702 and JP-A-1-314144, but this method is generally used. Compared with the conventional atmospheric pressure laminating method, there is a problem that the apparatus is large and dust is easily generated because the inside of the laminating chamber is vacuum. Further, a method of using a film having a smooth surface as a protective film is conceivable, but in this case, when the protective film is wound at the time of laminating, there is a problem that wrinkles of the protective film occur and the laminate cannot be laminated well.

[0009]

[Patent Document 1] Japanese Patent Publication No. 53-31670

[0010]

[Patent Document 2] Japanese Patent Application Laid-Open No. 51-63702

[0011]

[Patent Document 3] Japanese Patent Laid-Open No. 1-314144

[0012]

SUMMARY OF THE INVENTION The present invention reduces the number of air voids, which is extremely useful for increasing the number of pins in a lead frame or BGA, making it narrower, and increasing the density of printed wiring on which these semiconductor packages are mounted. Therefore, the present invention provides a method for producing a resist pattern which can be laminated with high yield and is excellent in laminating property, storage stability and workability. Another aspect of the present invention is that the number of air voids is reduced, which is extremely useful for increasing the number of pins in a lead frame or BGA, making them narrower, and increasing the density of printed wiring on which these semiconductor packages are mounted. The present invention provides a method for producing a printed wiring board or a lead frame having a resist pattern which is excellent in laminating property, storage stability and workability.

[0013]

The present invention is a photosensitive element having a support film (A), a photosensitive resin composition layer (B) and a protective film (C), the surface of the protective film (C). The roughness is such that Ra on the surface in contact with the photosensitive resin composition layer (B) is 0.15 μm or less and Rmax is 1.5 μm.
It is below, Ra of the surface which does not contact the photosensitive resin composition layer (B) is 0.1 to 0.8 μm, Rmax is 1 to 5 μm, and the diameter is 80 μm contained in the protective film (C).
A photosensitive element having a number of m or more fish eyes of 5 / m ² or less is laminated on a circuit-forming substrate so that the photosensitive resin composition layer (B) is in close contact with the substrate, and an active ray is emitted. The present invention relates to a method for producing a resist pattern, which comprises irradiating an image to photo-cur the exposed portion and removing the unexposed portion by development. Another aspect of the present invention relates to a method for producing a printed wiring board or a lead frame, which comprises etching or plating a circuit forming substrate having a resist pattern produced by the method for producing a resist pattern according to the present invention.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The support film (A) in the present invention includes, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, polyester, etc., from the viewpoint of transparency. It is preferable to use a polyethylene terephthalate film. Moreover, what is available is, for example, Tetron film GS manufactured by Teijin Ltd.
Examples thereof include polyester films such as the series and Mylar film D series manufactured by DuPont.

The thickness of the support film is preferably 1 to 100 μm, more preferably 12 to 25 μm. If the film thickness is less than 1 μm, the mechanical strength tends to be low, so that problems such as tearing of the support film during coating tend to occur, while if it exceeds 100 μm, the resolution tends to decrease and the cost tends to increase. Since these support films must be removable from the photosensitive resin composition layer later, they must not be surface-treated or made of a material that makes them impossible to remove. .

Photosensitive resin composition layer (B) in the present invention
Is not particularly limited as long as it has photosensitivity. (A) Binder polymer, (b) Photopolymerizable resin having at least one polymerizable ethylenically unsaturated group in the molecule. A composition comprising a compound and (c) a photopolymerization initiator.

As the above-mentioned (a) binder polymer,
Examples thereof include acrylic resin, styrene resin, epoxy resin, amide resin, amide epoxy resin, alkyd resin, and phenol resin. From the viewpoint of alkali developability, acrylic resins are preferred. These may be used alone or in combination of two or more. The (a) binder polymer is, for example,
It can be produced by radically polymerizing a polymerizable monomer.

Examples of the above-mentioned polymerizable monomer include styrene, vinyltoluene, α-methylstyrene and other polymerizable styrene derivatives substituted at the α-position or the aromatic ring, diacetone acrylamide and other acrylamides, Acrylonitrile, vinyl alcohol esters such as vinyl-n-butyl ether, acrylic acid alkyl ester, methacrylic acid alkyl ester, acrylic acid tetrahydrofurfuryl ester, methacrylic acid tetrahydrofurfuryl ester, acrylic acid dimethylaminoethyl ester, methacrylic acid dimethylamino Ethyl ester, acrylic acid diethylaminoethyl ester, methacrylic acid diethylaminoethyl ester, acrylic acid glycidyl ester, methacrylic acid glycidyl ester, 2,2,2- Trifluoroethyl acrylate, 2,2,2-trifluoroethyl methacrylate,
2,2,3,3-tetrafluoropropyl acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, acrylic acid, methacrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furylacrylic acid,
β-styryl acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, maleic acid monoesters such as monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, croton Examples thereof include acids and propiolic acid.

Examples of the acrylic acid alkyl ester or methacrylic acid alkyl ester include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid propyl ester, acrylic acid butyl ester, acrylic acid pentyl ester, acrylic acid hexyl ester and acrylic acid. Heptyl ester, acrylic acid octyl ester, acrylic acid 2-ethylhexyl ester, acrylic acid nonyl ester, acrylic acid decyl ester,
Acrylic acid undecyl ester, acrylic acid dodecyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid propyl ester, methacrylic acid butyl ester, methacrylic acid pentyl ester, methacrylic acid hexyl ester, methacrylic acid heptyl ester, methacrylic acid octyl ester , Methacrylic acid 2-ethylhexyl ester, methacrylic acid nonyl ester, methacrylic acid decyl ester, methacrylic acid undecyl ester, methacrylic acid dodecyl ester and the like. These may be used alone or in combination of two or more.

The (a) binder polymer is
From the viewpoint of alkali developability, it is preferable to contain a carboxyl group, and for example, it can be produced by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer. In that case, it is preferable to contain acrylic acid or methacrylic acid, and the content thereof is preferably 12 to 40% by weight from the viewpoint of the balance between alkali development and alkali resistance.
More preferably, it is 5 to 25% by weight. If the content is less than 12% by weight, the alkali developability tends to be poor, and if it exceeds 40% by weight, the alkali resistance tends to be poor.

The (a) binder polymer is
From the viewpoint of flexibility, it is preferable to contain styrene or a styrene derivative as a polymerizable monomer. These (a) binder polymers are used alone or in combination of two or more.

The weight average molecular weight of the binder polymer (a) is preferably 20,000 to 300,000, more preferably 40,000 to 200,000. This weight average molecular weight is 20,000
If it is less than 100, the mechanical strength tends to be poor, and if it exceeds 300,000, the alkali developability tends to be poor. The weight average molecular weight in the present invention is measured by a gel permeation chromatography method and converted by a calibration curve prepared using standard polystyrene.

The acid value of the binder polymer (a) is preferably 80 to 300 mgKOH / g.
More preferably, it is 0 to 200 mgKOH / g. If the acid value is less than 80, the developability tends to deteriorate, and
If it exceeds, the chemical resistance tends to deteriorate.

Examples of the photopolymerizable compound (b) having at least one polymerizable ethylenically unsaturated group in the molecule include polyhydric alcohols and polyhydric alcohols having α,
a compound obtained by reacting a β-unsaturated carboxylic acid,
Α, β-unsaturated carboxylic acid is added to 2,2-bis (4- (acryloxypolyethoxy) phenyl) propane, 2,2-bis (4- (methacryloxypolyethoxy) phenyl) propane, a glycidyl group-containing compound. Compound obtained by reaction, urethane monomer, nonylphenyldioxylene acrylate, nonylphenyldioxylene methacrylate, γ-chloro-β-hydroxypropyl-β ′
-Acryloyloxyethyl-o-phthalate, γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-acryloyloxyethyl-o-phthalate,
β-hydroxyethyl-β′-methacryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′
-Acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate, acrylic acid alkyl ester, methacrylic acid alkyl ester and the like can be mentioned.

Examples of the compound obtained by reacting the above polyhydric alcohol with α, β-unsaturated carboxylic acid include:
Polyethylene glycol diacrylate having 2 to 14 ethylene groups, polyethylene glycol dimethacrylate having 2 to 14 ethylene groups, polypropylene glycol diacrylate having 2 to 14 propylene groups, and propylene groups 2 to 14 polypropylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropane ethoxytriacrylate, trimethylolpropane ethoxytrimethacrylate, trimethylol Propane diethoxy triacrylate, trimethylol propane diethoxy trimethacrylate, trimethylol propane Reethoxytriacrylate, trimethylolpropane triethoxytrimethacrylate, trimethylolpropane tetraethoxytriacrylate, trimethylolpropane tetraethoxytrimethacrylate, trimethylolpropane pentaethoxytriacrylate, trimethylolpropane pentaethoxytrimethacrylate, tetramethylolmethanetriacrylate , Tetramethylol methane trimethacrylate, tetramethylol methane tetraacrylate, tetramethylol methane tetramethacrylate, polypropylene glycol diacrylate having 2 to 14 propylene groups, polypropylene glycol dimethacrylate having 2 to 14 propylene groups, di Pentaerythritol pentaacrylate, dipen Dipentaerythritol dimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexa methacrylate.

As the above α, β-unsaturated carboxylic acid,
For example, acrylic acid and methacrylic acid can be used. Examples of 2,2-bis (4- (acryloxypolyethoxy) phenyl) propane include 2,2-bis (4
-(Acryloxydiethoxy) phenyl) propane,
2,2-bis (4- (acryloxytriethoxy) phenyl) propane, 2,2-bis (4- (acryloxypentaethoxy) phenyl) propane, 2,2-bis (4
-(Acryloxydecaethoxy) phenyl) and the like. Examples of the 2,2-bis (4- (methacryloxypolyethoxy) phenyl) propane include 2,2
-Bis (4- (methacryloxydiethoxy) phenyl)
Propane, 2,2-bis (4- (methacryloxytriethoxy) phenyl) propane, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane,
2,2-bis (4- (methacryloxydecaethoxy) phenyl) propane and the like, and 2,2-bis (4-
(Methacryloxypentaethoxy) phenyl) propane is BPE-500 (product name, manufactured by Shin-Nakamura Chemical Co., Ltd.)
Is commercially available as.

Examples of the glycidyl group-containing compound include trimethylolpropane triglycidyl ether triacrylate, trimethylolpropane triglycidyl ether trimethacrylate, and 2,2-bis (4-).
Acryloxy-2-hydroxy-propyloxy) phenyl, 2,2-bis (4-methacryloxy-2-hydroxy-propyloxy) phenyl and the like can be used. Examples of the urethane monomer include an acrylic monomer having an OH group at the β-position or a corresponding methacrylic monomer and isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction product, tris (methacryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane dimethacrylate, EO, PO-modified urethane dimethacrylate, and the like. In addition, E
O represents ethylene oxide, and the EO-modified compound has an ethylene oxide group block structure. Further, PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide group.

Examples of the acrylic acid alkyl ester include acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid butyl ester, acrylic acid 2-ethylhexyl ester and the like. Examples of the methacrylic acid alkyl ester include methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid butyl ester, and methacrylic acid 2-ethylhexyl ester. These alone or 2
Used in combination with more than one type.

The concentration of the polymerizable ethylenically unsaturated group in the photopolymerizable compound (b) is 0.10 to 0.27 mol based on 100 g of the total amount of the components (a) and (b). It is preferably 0.11 to 0.26 mol, more preferably 0.14 to 0.25 mol, particularly preferably 0.18 to 0.23 mol. If the concentration is less than 0.10 mol, a peeling residue that is not easy to remove occurs in a product that requires the formation of a through hole having a minute diameter (diameter of 50 to 300 μm) or a half-etched portion during metal etching. If the amount exceeds 0.27 mol, the peeling time becomes long and the peeling remains or cannot be peeled off, which tends to have a great influence on the manufacturing time and the manufacturing apparatus. The concentration of the polymerizable ethylenically unsaturated group can be calculated from the following relational expression (1).

[0030]

[Equation 1]

The (c) photopolymerization initiator is any known compound that is activated by various actinic rays such as ultraviolet rays to initiate polymerization, and examples thereof include benzophenone and N, N'-tetramethyl-4. , 4'-diaminobenzophenone (Michler's ketone), N, N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butanone-1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-
Aromatic ketones such as 1, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone,
Octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone,
Quinones such as 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, 2-methyl 1,4-naphthoquinone and 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl. Benzoin ether compounds such as ether and benzoin phenyl ether, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzyl derivatives such as benzyldimethylketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2 -(O-chlorophenyl)-
4,5-di (methoxyphenyl) imidazole dimer,
2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl)-
2,4,5-Triarylimidazole dimers, etc. 2,4,5-Diphenylimidazole dimers, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimers, etc. Triaryl imidazole dimer, 9
Examples include acridine derivatives such as -phenylacridine, 1,7-bis (9,9'-acridinyl) heptane, N-phenylglycine, and coumarin compounds.

A thioxanthone compound and a tertiary amine compound may be combined, such as a combination of diethylthioxanthone and dimethylaminobenzoic acid.
From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. These are used alone or in combination of two or more.

The blending amount of the component (a) is 40-80 with respect to 100 parts by weight of the total amount of the components (a) and (b).
The amount is preferably parts by weight, and more preferably 50 to 70. If the blending amount is less than 40 parts by weight, the coating property is poor, and a resin called edge fusion tends to exude from the end of the photosensitive element, and if it exceeds 80 parts by weight, the sensitivity tends to be low and the mechanical strength tends to be weak. There is.

The blending amount of the component (b) is 20 to 60 based on 100 parts by weight of the total amount of the components (a) and (b).
It is preferably part by weight, and more preferably 30 to 50. If the blending amount is less than 20 parts by weight, the sensitivity tends to decrease and the mechanical strength tends to be weak, and if it exceeds 60 parts by weight, the coating property is poor, and a resin called edge fusion tends to exude from the end of the photosensitive element. There is.

The amount of the component (c) is 0.1 to 2 with respect to 100 parts by weight of the total amount of the components (a) and (b).
It is preferably 0 part by weight, more preferably 0.2 to 10 parts. If the amount is less than 0.1 parts by weight, the sensitivity tends to be insufficient, and if it exceeds 20 parts by weight, the absorption on the surface of the composition increases during exposure, resulting in insufficient internal photocuring. Tends to become.

In the photosensitive resin composition of the present invention, if necessary, a dye such as malachite green, a photo-coloring agent such as tribromomethylphenyl sulfone or leuco crystal violet, a thermal color-preventing agent, p-toluene sulfonamide. Such as plasticizers, pigments, fillers, defoamers, flame retardants, stabilizers, adhesion promoters, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. (a)
Each of the component and the component (b) may be contained in an amount of about 0.01 to 20 parts by weight based on 100 parts by weight. These are used alone or in combination of two or more.

The photosensitive resin composition of the present invention contains, if necessary, methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve,
A photosensitive resin composition layer (dissolved in a solvent such as toluene or N, N-dimethylformamide or a mixed solvent thereof and applied on the support film (A) as a solution having a solid content of about 30 to 60% by weight and dried. B) is formed. Then, a protective film (C) is laminated on the photosensitive resin composition layer to obtain a photosensitive element.

The thickness of the photosensitive resin composition layer (B) is from 1 to
The thickness is preferably 50 μm, more preferably 5 to 30 μm, and even more preferably 10 to 25 μm. If the thickness is less than 1 μm, the follow-up property tends to deteriorate, chipping and disconnection tend to occur, and if it exceeds 50 μm, the resolution tends to deteriorate.

The viscosity of the photosensitive resin composition layer (B) at 30 ° C. is preferably 15 to 50 Mpa · s, and 25
More preferably, it is -40 Mpa · s. Viscosity is 15Mp
If it is less than a · s, a resin called edge fusion tends to exude from the end of the photosensitive element,
If it exceeds pa · s, the resin flow becomes low, and air voids tend to occur. The viscosity can be measured in the present invention by using the following relational expression (2) for Newtonian fluid, plotting t against 1 / Z ⁴ , and calculating the slope thereof. These measurements are TM
It can be measured using the A device.

[0040]

[Equation 2]

In the protective film (C) of the present invention, the surface roughness of the protective film (C) is such that Ra on the surface in contact with the photosensitive resin composition layer is 0.15 μm or less and Rmax is 1.5 μm.
R of the surface which is less than or equal to m and does not contact the photosensitive resin composition layer
a must be 0.1 to 0.8 μm and Rmax must be 1 to 5 μm, and Ra on the surface in contact with the photosensitive resin composition layer is 0.
It is preferable that Rmax is 1 μm or less and Rmax is 1.0 μm or less, and Ra of the surface not contacting the photosensitive resin composition layer is 0.1.
It is preferable that it is 15 to 0.4 μm and Rmax is 1.5 to 3.0 μm.

When the surface roughness Ra of the surface in contact with the photosensitive resin composition layer exceeds 0.15 and the Rmax exceeds 1.5 μm, the surface shape of the protective film (C) becomes the photosensitive resin composition layer (B). ) Side, and the photosensitive resin composition layer is dented, causing air voids during lamination. If the surface roughness Ra of the surface that does not contact the photosensitive resin composition layer is less than 0.1 μm and Rmax is less than 1 μm, wrinkles occur during winding of the protective film during lamination, and the workability is improved. Can not. If the surface roughness Ra of the surface not contacting the photosensitive resin composition layer exceeds 0.8 μm and Rmax exceeds 5 μm, the photosensitive resin composition may be wound due to the winding tension during coating and slitting of the photosensitive element. The surface shape of the surface that does not come into contact with the material layer is transferred to the photosensitive resin composition layer and causes air voids during lamination.

The surface roughness according to the present invention is the JIS
The surface roughness in B0601 is represented, where Ra represents the center line average roughness, and Rmax represents the maximum height. Also,
The cutoff value is 0.08 mm and the measurement length is 2.5 mm. In addition, the diameter included in the protective film (C) is 80
It is preferable that the number of fisheyes of μm or more is 5 / m ² or less. The fisheye is a material in which foreign materials, undissolved materials, oxidative degradation materials, etc. are incorporated into the film when the material is heat-melted, kneaded, and extruded or stretched or a film is produced by a casting method. .

Thus, a film having a good fish eye level can be produced by selecting materials, optimizing the kneading method, and filtering after melting the materials. The size of the fisheye diameter is about 10 μm to 1 mm, depending on the material, and the height from the film surface is about 1 μm.
μm to 50 μm. Here, the fish eye size can be measured using, for example, an optical microscope, a contact surface roughness meter, a non-contact surface measuring instrument using a laser beam, a scanning electron microscope, or the like. The diameter of the fish eye in the present invention means the maximum diameter of the fish eye.

The thickness of the protective film (C) is 1 to 100 μm.
m is preferable, 5 to 50 μm is more preferable, and 15 to 50 μm is particularly preferable. When the thickness is less than 1 μm, the strength of the protective film is insufficient, and therefore, when the protective film is attached to the photosensitive resin composition layer, the protective film tends to be easily broken. Wrinkles tend to occur when laminating.

Such a protective film is commercially available, for example, Alphan MA-410 manufactured by Oji Paper Co., Ltd.,
Examples include, but are not limited to, E-200C, polypropylene film manufactured by Shin-Etsu Film Co., Ltd., and polyethylene terephthalate film such as PS series manufactured by Teijin Ltd. PS-25. In addition, it is possible to easily manufacture a commercially available film by sandblasting.

Further, the adhesive strength between the photosensitive resin composition layer (B) and the support film (A) may be larger than the adhesive strength between the photosensitive resin composition layer (B) and the protective film (C). preferable. The adhesive strength between the photosensitive resin composition layer (B) and the support film (A) is determined by the photosensitive resin composition layer (B).
When the adhesive strength between the protective film and the protective film (C) is smaller than the adhesive strength, the photosensitive resin composition layer tends to be transferred to the protective film side when the protective film is removed during lamination.

The photosensitive element in the present invention can be obtained, for example, by applying the above-mentioned photosensitive resin composition on a support film, drying it, and laminating a protective film. When producing a resist pattern using this photosensitive element, for example, a method of laminating after removing the protective film and pressing the photosensitive resin composition layer onto the circuit-forming substrate while heating the layer can be mentioned. The surface to be laminated is usually a metal surface, but there is no particular limitation. The heating temperature of the photosensitive resin composition layer is preferably 90 to 130 ° C., and the pressure bonding is 0.1 to 1.0 MPa (1 to 10 kPa).
g / cm2) is preferable, but these conditions are not particularly limited. Further, if the photosensitive resin composition layer is heated to 90 to 130 ° C. as described above, it is not necessary to preheat the circuit forming substrate in advance, but in order to further improve the laminate property, It is also possible to preheat the substrate.

The photosensitive resin composition layer thus laminated is irradiated with actinic rays imagewise through a negative or positive mask pattern called artwork. At this time, when the polymer film present on the photosensitive resin composition layer is transparent, it may be irradiated with actinic rays as it is, and when it is opaque, it is of course necessary to remove it. From the viewpoint of protecting the photosensitive resin composition layer, it is preferable that the polymer film is transparent and the actinic ray is irradiated through the polymer film while the polymer film remains. As the light source of the actinic ray, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, or a xenon lamp that effectively emits ultraviolet rays is used. In addition, a flood light bulb for photography, a solar lamp or the like that effectively radiates visible light is also used.

Then, after the exposure, if a support is present on the photosensitive resin composition layer, after removing the support,
A resist pattern is manufactured by using a developer such as an alkaline aqueous solution to remove the unexposed portion and develop it by a known method such as spraying, rocking dipping, brushing, scraping or the like. As the developer, a safe and stable developer having good operability such as an alkaline aqueous solution is used. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxides, alkali carbonates such as lithium, sodium, potassium or ammonium carbonates or bicarbonates, potassium phosphate, phosphoric acid. Alkali metal phosphates such as sodium, sodium pyrophosphate, alkali metal pyrophosphates such as potassium pyrophosphate, and the like are used.

As the alkaline aqueous solution used for the development, a dilute solution of 0.1 to 5% by weight of sodium carbonate,
0.1-5 wt% dilute potassium carbonate solution, 0.1-5
Dilute solution of sodium hydroxide by weight, 0.1-5% by weight
A dilute solution of sodium tetraborate is preferred. The pH of the alkaline aqueous solution used for development is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive resin composition layer. Further, a surface active agent, a defoaming agent, a small amount of an organic solvent for accelerating development may be mixed in the alkaline aqueous solution. Development methods include a dip method and a spray method, and the high pressure spray method is most suitable for improving the resolution.

As a processing after development, if necessary, 80 to
The resist pattern may be further cured and used by heating at about 250 ° C. or exposure at about 0.2 to 5 mJ / cm ² .

A cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or a hydrogen peroxide-based etching solution can be used for the etching of the metal surface after the development. It is desirable to use a ferric solution.

When a printed wiring board or a lead frame is manufactured using the photosensitive element, the surface of the circuit-forming board is covered with the developed resist pattern as a mask.
It is processed by a known method such as etching or plating. Examples of the plating method include copper sulfate plating, copper plating such as copper pyrophosphate, solder plating such as high-throw solder plating, Watts bath (nickel sulfate-nickel chloride) plating, nickel plating such as nickel sulfamate plating, and hard plating. There are gold plating such as gold plating and soft gold plating. Then, the resist pattern is usually stripped with an aqueous solution having a stronger alkaline property than the alkaline solution used for the development. As the strongly alkaline aqueous solution, for example, a 1 to 5 wt% sodium hydroxide aqueous solution, a 1 to 5 wt% potassium hydroxide aqueous solution, or the like is used. Further, the printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board.

Further, the photosensitive element of the present invention is suitable as a photosensitive element for metal etching processing used for manufacturing lead frames, metal masks and the like.

[0056]

The present invention will now be described with reference to examples, but the present invention is not limited thereto.

Examples 1-2 and Comparative Examples 1-3 Components (a), (b), (c) and other components shown in Table 1 were mixed to prepare a solution.

[0058]

[Table 1]

Next, 16 parts of this photosensitive resin composition solution was added.
It was evenly coated on a polyethylene terephthalate film having a thickness of μm and dried by a hot air convection dryer at 100 ° C. for about 5 minutes, and each protective film shown in Table 2 was laminated to obtain a photosensitive element. The film thickness of the photosensitive resin composition layer after drying was 20 μm. Further, the surface roughness of each protective film to be used is measured by using a contact surface roughness measuring device SE-3D (manufactured by Kosaka Laboratory Ltd.), and according to JIS B0601, the center line average roughness Ra and the maximum height Rmax. Was measured. The results are shown in Table 2.
Shown in.

The photosensitive resin composition layers of the photosensitive element prepared above were overlaid to prepare a test piece having a thickness of 1 mm and a diameter of 7 mm. Next, a TMA apparatus (Termal Analysi) was used.
s: Seiko Denshi Kogyo Co., Ltd., TMA / SS100), and 2 each in the thickness direction of the test piece at 30 ° C to 80 ° C.
A load of -40 g was applied and the amount of change in the thickness direction was measured.
Next, using the relational expression (2) for the Newtonian fluid, t was plotted against 1 / Z ⁴ and the viscosity was calculated from the slope. Further, the photosensitive element prepared above was cut into a piece having a width of 2 cm, and a rheometer (manufactured by Fudo Kogyo Co., Ltd.) was used.
The 180 ° peel strength between each protective film and the photosensitive resin composition layer was measured. Similarly, the 180 ° peel strength between the support film and the photosensitive resin composition layer was measured.

On the other hand, the thickness is 0.15 mm, 20 cm × 20 cm
Corner Copper Alloy (Yamaha Orin Metal Co., C-702
5) was dipped in a 3% by weight aqueous solution of sodium hydroxide at 50 ° C. for 1 minute, then dipped in a 1% by volume aqueous solution of hydrochloric acid at 25 ° C. for 1 minute, then washed with water and dried, and the photosensitive element was placed on the obtained substrate. While removing the protective film of No. 1, the laminate was laminated at a roll temperature of 110 ° C., a pressure of 0.39 MPa and a speed of 2 m / min. Then, the substrate thus obtained was applied to a 3 kW ultra high pressure mercury lamp (HMW manufactured by Oak Manufacturing Co., Ltd.).
-201 GX) and exposed at 50 mJ / cm ² . The number of air voids on the substrate after exposure was measured using a 100 × optical microscope. In addition, the size and number of fish eyes of each support film were measured using a 100 × microscope. The results are summarized in Tables 2 and 3.

[0062]

[Table 2]

[0063]

[Table 3]

As is clear from Tables 2 and 3, the number of fish eyes having a diameter of 80 μm or more as the protective film (C) was 5 / m ² , and the surface of the surface in contact with the photosensitive resin composition layer was Roughness Ra is 0.15 μm or less, Rmax is 1.5 μm or less, and the surface roughness Ra of the surface not contacting the photosensitive resin composition layer is 0.1 to 0.8 μm and Rmax is 1 to
It can be seen that the use of the film of 5 μm reduces the number of air voids that cause chipping and disconnection, and improves the laminating property.

[0065]

The method of manufacturing a resist pattern according to the present invention produces air voids, which are extremely useful for increasing the number of pins in a lead frame or BGA, making them narrower, and increasing the density of printed wiring on which these semiconductor packages are mounted. Since the number is reduced, the product can be laminated with high yield, and is excellent in laminating property, storage stability and workability.

The method for manufacturing a printed wiring board or a lead frame according to the present invention is an air void which is extremely useful for increasing the number of pins in a lead frame or BGA, for narrowing the wiring, and for increasing the density of printed wiring on which these semiconductor packages are mounted. It is possible to stack with good yield because the number of
In addition, it has a resist pattern having excellent laminating property, storage stability and workability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating the generation of air voids.

[Explanation of symbols]

1 Support film 2 Photosensitive resin composition layer 3 protective film 4 fish eyes 5 substrates 6 air voids

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H025 AB11 AB15 AB16 AB17 AC01                       AD01 BC14 BC32 BC42 CA01                       CA20 CA27 CA28 CB14 CB16                       CB52 DA02 FA03 FA17 FA40                       FA43                 5E339 AB02 BC01 BE11 CC01 CC10                       CD01 CE12 CE16 CF01 CF16                       CF17 DD02 FF02 GG02                 5E343 AA02 AA12 AA39 BB21 BB71                       CC62 DD32 ER16 ER18 GG08                       GG20

Claims (9)

[Claims] 1. A photosensitive element comprising a support film (A), a photosensitive resin composition layer (B) and a protective film (C), wherein the surface roughness of the protective film (C) is a photosensitive resin composition. Ra of the surface in contact with the material layer (B) is 0.15μ
m or less, Rmax is 1.5 μm or less, and Ra on the surface not in contact with the photosensitive resin composition layer (B) is 0.1 to 0.8 μm.
m, Rmax is 1 to 5 μm, and a photosensitive element in which the number of fish eyes having a diameter of 80 μm or more contained in the protective film (C) is 5 / m ² or less is provided on a circuit-forming substrate, A resist pattern, characterized in that the photosensitive resin composition layers (B) are laminated so as to be in close contact with each other, actinic rays are imagewise irradiated to photo-cur the exposed portions, and the unexposed portions are removed by development. Manufacturing method. 2. The surface roughness of the protective film (C) is such that Ra on the surface in contact with the photosensitive resin composition layer (B) is 0.1 μm.
Hereafter, Rmax is 1.0 μm or less, and Ra on the surface not in contact with the photosensitive resin composition layer (B) is 0.15 to 0.4 μm.
The method for producing a resist pattern according to claim 1, wherein m and Rmax are 1.5 to 3.0 μm. 3. The photosensitive resin composition layer (B) comprises (a) a binder polymer, (b) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated group in the molecule, and (c) light. The method for producing a resist pattern according to claim 1, further comprising a polymerization initiator. 4. The adhesive strength between the photosensitive resin composition layer (B) and the support film (A) is higher than the adhesive strength between the photosensitive resin composition layer (B) and the protective film (C). 4. The method for producing a resist pattern according to any one of items 1 to 3. 5. The method for producing a resist pattern according to claim 1, wherein the protective film (C) is a polypropylene film or a polyethylene terephthalate film. 6. The method for producing a resist pattern according to claim 1, wherein the protective film (C) is removed when the circuit-forming substrate is laminated. 7. The thickness of the photosensitive resin composition layer (B) is 1 to
It is 50 micrometers, The manufacturing method of the resist pattern of any one of Claims 1-6. 8. The thickness of the photosensitive resin composition layer (B) is 5 to 5.
It is 30 micrometers, The manufacturing method of the resist pattern of any one of Claims 1-6. 9. A printed wiring board or a lead frame, comprising: etching or plating a circuit-forming substrate having a resist pattern manufactured by the method for manufacturing a resist pattern according to claim 1. Description: Manufacturing method.