KR100752149B1 - Photo-sensitivity polymer layer, dry film, method for forming circuit lines, and printed circuit board formed thereby - Google Patents

Abstract

Provided are a photo-sensitive polymer layer having a nonpolymerizable part to remain after exposure and development, a dry film having the polymer layer, a method for forming circuit lines using the dry film and a printed circuit board formed by the method. A photo-sensitive polymer layer(30) comprises a photopolymerizable layer(31) and a semi-photopolymerizable layer(32). The photopolymerizable layer(31) comprises a polymer binder; a photoinitiator to provide chemical activity in a wavelength range in which the light absorption of the polymer binder is poor when irradiated; and a photopolymerizable monomer to bind the polymer binders when irradiated. The semi-photopolymerizable layer(32) comprises a photopolymerizable part and a nonphotopolymerizable part. The photopolymerizable part comprises the polymer binder; the photoinitiator; and the photopolymerizable monomer. The photopolymerizable part and the nonphotopolymerizable part are placed alternately.

Description

Photo-Sensitivity Polymer Layer, Dry Film, Method for Forming Circuit Lines, and Printed Circuit Board Formed Thereby}

1 is a flow chart showing an etching step according to a general method;

2 is a schematic diagram showing an etching range according to a general method;

3 is a flowchart showing an etching step according to a preferred embodiment of the present invention;

4 is a schematic diagram showing an etching range according to a preferred embodiment of the present invention;

5 is a cross-sectional view of a dry film according to an embodiment of the present invention;

6 is a cross-sectional view showing a semi-light-curing layer according to an embodiment of the present invention; And

7 is a flowchart illustrating a method of forming a circuit wiring according to an exemplary embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

30 photosensitive polymer layer 31 photopolymerization layer

32: semi-light polymerization layer 33: protective layer

34 support layer 321 photopolymerization part

323: non-light-curing portion 40: conductive layer

50: mask

The present invention relates to a photosensitive polymer layer that can be used as a photoresist, a dry film comprising the photosensitive polymer layer, a method of forming a circuit wiring using the dry film, and a substrate including the circuit wiring formed thereby. In particular, it relates to a photosensitive polymer layer, a dry film that can be used to form circuit wiring by a substractive method.

In the conventional multilayer printed circuit board, an inner layer circuit is formed by applying an additive method or a subtractive method to the surface of a core substrate including a conductive layer such as a copper clad laminate (CCL), and an insulating layer and It is manufactured by forming an outer layer circuit in the same manner as an inner layer circuit while sequentially building up a metal layer.

In the method of forming an inner layer circuit by the subtractive method, a photoresist is laminated on a conductive layer that has undergone a pretreatment step such as an imaging process, and the work film on which the wiring pattern is printed is brought into close contact with the photoresist. Through the exposure and development processes, portions other than those corresponding to the circuit pattern are etched and removed, and the substrate is etched to form an inner layer circuit. When the photoresist is removed and the circuit wiring is completed, quality-related circuit inspection processes such as open or slits are finally performed.

When the wiring is formed by the conventional method, since the water-soluble etching solution is etched in all directions, side etching occurs, thereby reducing the width of the circuit wiring of the circuit and increasing the spacing between the wirings. Accordingly, there is a limit in the width of the circuit formation, and there is a limit in that circuit wiring having a width of 30 μm or less cannot be formed. Therefore, there is a problem that other equipment or expensive equipment for forming fine circuit wiring is required in order to manufacture electronic products requiring high function, high density, and small amount. In addition, when looking at the cross section of the formed circuit wiring, a trapezoidal circuit wiring having a narrow upper width and a wider lower width is formed. This type of circuit wiring reduces the circuit cross-sectional area, causing the circuit wiring to deteriorate frequency characteristics and signal transmission efficiency. Not preferred.

The present invention provides a photosensitive polymer layer and a dry film, such that the non-photosynthesis may remain in the portion removed in the exposure and development process, including the non-photopolymerization to solve the above problems.

The present invention also provides a printed circuit board including a fine circuit wiring formed thereby and a method of forming a circuit wiring having a fine but small difference between an upper width and a lower width by improving the vertical direction of etching due to the remaining non-photosynthetic portion. do.

In addition, the present invention has a spacing between circuit wirings of 30 µm or less, which is difficult to form by a conventional subtractive method, and forms a fine circuit wiring of 30/30 or less in the width of the circuit wiring / the spacing between the circuit wirings. A method and a printed circuit board including such fine circuit wiring are provided.

In addition, the present invention can form a fine circuit wiring to increase the frequency characteristics of the circuit wiring to improve the signal transmission efficiency, to eliminate the need for additional equipment, to form a circuit wiring that can use the existing line and the existing method A method and a printed circuit board including such circuit wiring are provided.

According to one aspect of the invention, the photosensitive polymer layer comprises a photopolymerization layer and a semi-photopolymerization layer, the photopolymerization layer is a polymer binder; A photoinitiator which, when irradiated with light, imparts chemical activity in a wavelength band where the light absorption of the polymer binder is low; And a photopolymerizable monomer that bonds the polymer binders when the light is irradiated, wherein the semi-photopolymerization layer includes a photopolymerization unit and a non-photopolymerization unit, and the photopolymerization unit comprises: the polymer binder; The photoinitiator; And the photopolymerizable monomer, wherein the non-photopolymerizable portion is the polymer binder; And it can present a photosensitive polymer layer comprising the photopolymerization monomer.

Here, the photopolymerization unit and the non-photopolymerization unit may be alternately arranged.

In addition, the thickness of the semi-light polymerization layer may be 0.1 to 10 times the thickness of the photopolymerization layer, the thickness of the photosensitive polymer layer may be 5 to 100㎛, the thickness of the semi-light polymerization layer may be 0.45 to 91㎛. .

According to another aspect of the present invention, it is possible to provide a dry film including the photosensitive polymer layer, the support layer and the protective layer described above.

Here, the photopolymerization unit and the non-photopolymerization unit may be alternately arranged.

In addition, the thickness of the semi-light polymerization layer may be 0.1 to 10 times the thickness of the photopolymerization layer, the thickness of the photosensitive polymer layer may be 5 to 100㎛, the thickness of the semi-light polymerization layer may be 0.45 to 91㎛. .

According to another aspect of the invention, (a) laminating the dry film on a substrate including a conductive layer; (b) removing a portion of the dry film to correspond to the wiring pattern by exposure and development; And (c) etching and removing the exposed conductive layer by removing a portion of the dry film.

Here, in the step (b), the non-photopolymerization part included in the part of the removed dry film may remain on the conductive layer without being removed, and have a fine circuit having a spacing between the circuit wirings of 30 μm or less. Wiring can be formed.

According to another aspect of the present invention, it is possible to provide a printed circuit board including the fine circuit wiring formed by the above-described method of forming the circuit wiring. Here, the spacing between the fine circuit wirings may be 10 to 30 μm.

Hereinafter, preferred embodiments of a photosensitive polymer layer according to the present invention, a dry film including the photosensitive polymer layer, a method of forming circuit wiring using the dry film, and a circuit wiring formed thereby are provided. It will be described in detail with reference to the drawings. In addition, before describing preferred embodiments of the present invention in detail, the behavior of the etchant during the etching of the conductive layer will be described first.

1 is a flowchart illustrating an etching step according to a general method. Referring to FIG. 1, after the photoresist 13 is formed on the conductive layer 10 according to a wiring pattern, the conductive layer 10 is treated with an etching solution. In general, in the wet etching process, the etching is performed in all directions due to the properties of the water-soluble etching solution. Accordingly, as shown in FIG. 1B, the etching solution is etched from side to side, along with the etching in the target vertical direction, and overetching occurs at the bottom surface of the photoresist 13. In addition, as shown in FIG. 1C, the cross section of the circuit wiring formed as the difference between the upper width and the lower width of the conductive layer increases with the degree of etching becomes trapezoidal. Due to the undesired cross-sectional shape of the circuit wiring, the frequency characteristics and signal transmission efficiency of the circuit are reduced, and it is difficult to adjust the factors related to the circuit formation, causing unexpected overetching or non-etching problems.

2 is a schematic diagram showing an etching range according to a general method. Referring to FIG. 2, when etching starts, etching starts in a circle having a radius r ₁ . Here, r ₁ refers to the interval between photoresists after development and before etching. As the etching proceeds, the etching liquid moves in all directions and the etching continues in a circle having a maximum radius r ₂ . Here, r ₂ represents the radius of actual side etching as the etching progresses, which is a standard for etching during equipment operation, and is a value easily found by performing legs by conveyor speed. L ₁ is the expected width of the upper surface of the circuit wiring before etching, L ₂ is the theoretical minimum upper surface width of the circuit wiring after etching, and Z is the amount of change of the upper surface of the circuit wiring before and after etching, that is, L ₁ -L ₂ Equivalent to, which theoretically agrees with the value of r ₂ -r ₁ .

However, in the present invention, the non-photopolymerization part remains after exposure and development, thereby improving the vertical direction of etching, and thus, fine circuit wiring can be formed. 3 is a flowchart illustrating an etching step according to an exemplary embodiment of the present invention. As shown in FIG. 3A, a portion of the photosensitive polymer layer 30 of the present invention is removed by photoresist on the conductive layer 40 so as to correspond to a desired wiring pattern through exposure and development. The photosensitive polymer layer 30 of the present invention is divided into a photopolymerization layer 31 and a semi-light polymerization layer 32, and the semi-light polymerization layer 32 is further divided into a photopolymerization portion and a non-photopolymerization portion. The upper surface of the conductive layer 40 is exposed to the portion removed by exposure and development, and the non-light-polymerization portion is left without being removed. Therefore, during etching, selective etching occurs first at the portion where the conductive layer is exposed, and the portion where the non-light-polymerization portion remains is etched later. As the etching proceeds as shown in FIGS. 3B and 3C, the vertical direction of the etching solution is improved, and the etching is performed while spreading less to the left and right. The circuit wiring finally formed as shown in FIG. 3 (d) has a small cross-section between the upper width and the lower width and has a rectangular cross section. Accordingly, the width between circuit wirings can be reduced, so that fine circuit wiring can be formed, and the frequency characteristics and signal transmission efficiency of the circuit are increased due to the cross-sectional shape of the desired circuit wiring, and the prediction and control of circuit formation-related factors are easy. Less problems with over-etching or non-etching

4 is a schematic diagram showing an etching range according to a preferred embodiment of the present invention. Referring to FIG. 4, when etching starts, etching starts in a circle having a radius R ₁ . Here, R ₁ refers to the interval between the non-light-cured portion or the non-light-cured portion and the unexposed portion after the development. As the etching proceeds, the etching liquid moves in all directions to continue etching in a circular shape having a maximum radius R ₂ . Here, R ₂ represents the radius of actual side etching as the etching progresses, which is a standard for etching during equipment operation, and is easily found by performing legs by conveyor speed. M ₁ is the expected width of the upper surface of the circuit wiring before etching, M ₂ is the theoretical minimum upper surface width of the circuit wiring after etching, and Y is the amount of change of the upper surface of the circuit wiring before and after etching, that is, M ₁ -M ₂ Is the same as, and theoretically agrees with the value of R ₂ -R ₁ .

The behavior of the etchant has been described with reference to the drawings, which are generally illustrated. Hereinafter, a method of forming a photosensitive polymer layer, a dry film, a circuit wiring according to the present invention, and a printed circuit board formed thereby will be described. .

5 is a cross-sectional view of a dry film according to a preferred embodiment of the present invention, Figure 6 is a cross-sectional view showing a semi-light polymerization layer according to a preferred embodiment of the present invention. Referring to FIG. 5, the dry film includes a photosensitive polymer layer 30, a protective layer 33 made of a material such as polyester, and a support layer 34 made of a material such as polyethylene. The photosensitive polymer layer includes a photopolymerization layer 31 and a semi-photopolymerization layer 32. Referring to FIG. 6, the semi-light-curing layer 32 is further divided into a light-curing portion 321 and a non-light-curing portion 323, which are alternately arranged. Here, the photopolymerization layer 31 and the photopolymerization part 321 are made of a photosensitive polymer material including the same or different conventional, for example, a polymer binder, a photoinitiator, a photopolymerization monomer. However, the non-photopolymerization part 323 does not include a photoinitiator so as not to exhibit photosensitivity, and thus does not polymerize by light having a predetermined external wavelength. Therefore, the non-light-cured polymer 323 remains on the upper portion of the conductive layer even if the exposed portion is subsequently removed by exposure and development, thereby contributing to forming fine printed wiring.

In the dry film, a protective layer (protect film or cover film) 33 has important characteristics such as transmittance and static electricity to protect the photosensitive polymer layer 30, and the base film 34 is also a photosensitive polymer layer 30 The protective layer is removed when the dry film is laminated to form a photoresist.

In the method of forming printed wirings on the conductive layer by using the dry film according to the wiring pattern, a dry film, especially the photosensitive polymer layer 30, is laminated on the conductive layer 40 with photoresist, as shown in FIG. As shown in FIG. 7B, a mask 50 having a pattern corresponding to a desired wiring pattern such as a work film is positioned on the photosensitive polymer layer 30. After exposure to predetermined light such as ultraviolet rays, X-rays, or electron beams (EB), as shown in FIG. 7C, the mask 50 is removed, and the photosensitive polymer is formed into a conventional developer, for example, an aqueous alkali solution. A portion of layer 30 is removed. The case where the exposed part dissolves by development is referred to as a positive resist. On the contrary, the case where the exposed part remains and the unexposed part dissolves by development is referred to as a negative resist. According to a preferred embodiment of the present invention, if a portion of the photosensitive polymer layer is exposed to remove the exposed portion, a portion (non-polymerized portion 323) which does not cause photopolymerization sandwiched in the exposed portion may remain. It is preferable to carry out with a resist.

As shown in (a) of FIG. 8, the conductive layer 40 is selectively etched with a conventional etching solution, and etching of the conductive layer 40 proceeds in the vertical direction as shown in FIGS. 8 (b) and (c). . As shown in FIG. 8 (d), circuit wiring close to a square is formed.

According to the method of forming the printed wiring of the present invention, it is possible to form a fine circuit wiring with a spacing between the printed wiring is 30㎛ or less, it is possible to provide a printed circuit board comprising the same.

The general description has been given above with reference to the accompanying drawings. Hereinafter, the photosensitive polymer layer and the dry film according to the present invention will be described with reference to specific examples.

1) Photosensitive polymer layer

The photosensitive polymer layer according to the preferred embodiment of the present invention includes a photopolymerization layer and a semi-photopolymerization layer. In this case, the photopolymerization layer may be made of a material which can be polymerized by light like a conventional photoresist. For example, when exposed to a predetermined light such as a polymer binder, ultraviolet rays, X-rays or electron beams, photoinitiators that impart chemical activity in a wavelength band where the light absorption of the polymer binder is low, and light are irradiated It may include a photopolymerizable monomer (monomer) for bonding the polymer binders. However, the present invention is not limited thereto and may be configured within the conventional scope of the art.

Here, the semi-light-curing layer is further divided into a non-light-curing portion and a light-curing portion, and it is preferable that the photo-polymerizing portion fills the periphery of the non-light-polymerizing portion, and it is more preferable that they are alternately arranged. The photopolymerization part may be made of a material which can be polymerized by light, such as a conventional photoresist. For example, it may include a polymer binder, a photoinitiator, and a photopolymerizable monomer. However, the photopolymerization unit is not limited thereto and may be configured within a conventional range in the art.

The non-photopolymerization part may be used without limitation other components except photoinitiators in the conventional photoresist composition, and may include, for example, a polymer binder and a photopolymerization monomer. However, it is not necessarily limited thereto.

In addition, as the width of the non-light-curing portion to be formed narrows, the proportion of the non-light-curing portion in the semi-light-curing layer increases. As the width of the non-light-curing portion is formed, the portion of the non-light-curing portion decreases. However, the non-light-curing portion cannot have a width wider than the distance between the circuit wirings. In addition to the width of the circuit wiring to be formed or the distance between the circuit wirings, the semi-photopolymerization depends on the thickness of the entire photoresist or dry film, the ratio of the photopolymerization layer and the semi-photopolymerization layer, the nature of the etching solution used, for example, the oxidation degree of the etching solution, and the like. The proportion of the non-light-curing portion in the layer can be determined. Although not limited thereto, the non-photopolymerization part may be included at a ratio of 0.001 to 100 with respect to the photopolymerization part, and may be included at a volume ratio of 0.00001 to 10000 with respect to the photopolymerization part.

Here, the photopolymerization layer and the photopolymerization portion may have the same configuration, may have different configurations, and the same configuration is preferable for uniform photochemical reaction. In addition, the photopolymerization layer, the photopolymerization portion and the non-photopolymerization portion may be the same as other components except for the photoinitiator, it may be of course different configuration.

(1) polymer binders

It is used to impart the tendency and adhesion of the mechanical strength of the photosensitive polymer composition. Examples of the polymer binders generally used in positive resists include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl acrylate. , Butyl acrylate, isobutyl methacrylate, atyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, glycidyl methacrylate, Acrylic acid, methacrylic acid, monoacrylic acid, maleic acid, fumaric acid, styrene, hydroxy styrene, acrylonitrile, vinyl acetate, and the like are included, but the scope of the present invention is not limited thereto.

(2) photoinitiator

In addition, the photoinitiator used in the present invention is a chemical (free radical), physical change of the molecular structure within a short time in the region of the wavelength range of 200 to 450nm, solubility change (for example, solubilization or insolubilization) to any solvent, It refers to a polymer composition system in which physical property changes such as coloring and curing occur. By light, the polymer binder undergoes photopolymerization in which the monomer becomes a polymer and a photocrosslinking reaction occurs in which the monomer is changed into a three-dimensional crosslinked polymer.

 Examples of such photoinitiators include benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether; Acetophenone, 2,2-dimethoxy-2-acetophenone, 2,2-dimethoxy-2-phenyl acetophenone, 1,1-dichloro acetophenone, 4-methoxy-2,2-dichloro acetophenone, and the like Acetophenones; Anthraquinones such as 2-methylanthraquinone, 2-talt-butylanthraquinone, 1-chloroanthraquinone, and 2-amylanthraquinone; 2,4-dimethylthiorsanthone, 2,4-diethylthiorsanthone, Thiosanthones such as 1-chlorothiorsanthone, 2,4-diisopropyl thiosanthone, 2-isopropyl thiosanthone, and 1-chloro-4-propoxy thioxanthone; Ketals such as acetophenone dimethyl ketal, benzyl dimethyl ketal and 2,2-diethoxy-1,2-diphenylethanone; Benzophenone, 4-chloro benzophenone, 4,4'-bis (dimenylamino) benzophenone, 4,4'-bis (diethylamino) benzophenone, 4- (4'-dimethylphenylthio) benzophenone, etc. Benzophenols; 2,4,6-trimethylbenzoindiphenyl phosphine oxide, 2,4,6-trimethylbenzoindiphenyl phosphinic acid ester, bis (2,4,6-trimethylbenzoin) -pentyl phosphine oxide and acrylic phosphine Oxides, bis [2- (2-chlorophenyl) -4,5-diphenyl] -imidazole, 2,2'-bis (2-chlorophenyl) -4,4 ', 5,5' tetraphenyl- 1,2'biimidazole, 2-ethyl antriquinone, 2- (O-chlorophenyl) -4,5-diphenyl imidazole dimer, 2- (O-chlorophenyl) -4,5-di (m -Methoxy) phenyl imidazole dimer, 2- (O-fluorophenyl) -4,5-diphenyl imidazole dimer, 2,4-di (P-methoxyphenyl) -5-diphenyl imidazole dimer, 2 -(2,4-dimethoxyphenyl) -4,5-diphenyl imidazole dimer, 2- (P-methyl captophenyl) -4,5-diphenyl imidazole dimer and 2,4,5-trianyl imide Misellaneous, such as a disol dimer; 4,4'-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-methyl-4- (dimethyl amino) benzoate, 2-ethylhexyl-4- (dimethylamino) benzoate, 1-hydro Hydroxy-cyclohexyl-phenylketone, 2-hydroxy-2-methyl-1-phenylpropane-1-α-hydroxy and amino alkylphenones, although the invention is not so limited.

(3) photopolymerization monomer

In addition, generally used photopolymerizable monomers include ethylenically unsaturated compounds, which include poly or monofunctional groups and are crosslinkable. Monomers having a double bond crosslink and have a very large molecular weight. It can be preferably used to form a polymerized three-dimensional network. For example, trivinylbenzene, divinyl toluene, divinyl pyridine, divinyl naphthalene and divinyl xylene, ethylene glycol diacrylate, trimetholpropane triacrylate, diethylene glycol divinyl ether, trivinyl cyclohexane , Allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, propylene glycol dimethacrylate, propylene glycol diacrylate, trimetholpropane trimethacrylate, polyvinylbenzene, glycidyl Methacrylate, 2,2-dimethylpropane, 1,3-diacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol diacrylate , Diethylene glycol diacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tripropylene article Cold Diacrylate, Triethylene Glycol Dimethacrylate, Tetraethylene Glycol Diacrylate, Polyethylene Glycol 200 Diacrylate, Tetraethylene Glycol Dimethacrylate, Polyethylene Glycol Dimethacrylate, Ethoxylated Bisphenol A Diacrylate, Ethoxylated Bisphenol A Dimethacrylate, Polyethylene Glycol 600 Dimethacrylate, Poly (butanediol) Diacrylate, Pentaerythritol Triacrylate, Trimetholpropane Triethoxy Triacrylate, Glycerylpropoxy Triacrylate , Pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol monohydrocipentaacrylate, divinyl silane, trivinyl silane, dimethyl divinyl silane, divinyl methyl silane, methyl trivinyl silane, Diphenyl divinyl silane, di Vinyl phenyl silane, trivinyl phenyl silane, divinyl methyl phenyl silane, tetravinyl silane, dimethyl vinyl disiloxane, poly (methyl vinyl siloxane), poly (vinyl hydrosiloxane), poly (phenyl vinyl siloxane) and mixtures thereof However, the scope of the present invention is not limited thereto.

(4) additive

Examples of the solvent used in the present invention as other additives include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; Polyhydric alcohols such as ethylene glycol, diethylene glycol mono acetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol mono methyl ether acetic acid and dipropylene glycol mono acetate; Ester solvents such as cyclic ether solvents such as monomethyl, monoethyl, monopropyl, monobutyl, methyl acetate, ethyl acetate, and butyl acetate; Cellosol classes, such as a methyl cellosol part and an ethyl cellosol part, nitriles, such as an acrylonitrile, etc. are mentioned.

As another additive, a dye stabilizer, an adhesion promoter, and a thermal polymerization inhibitor may be further included. Here, blue dyes (Dyestuffs) are used, which is used to determine the presence of coating properties such as pinholes, fisheye, craters, etc. during coating inspection, admixes auxiliary pigments for color change after exposure, and exposure with a photoacid or photoimage forming agent. The post-cured portion may be colored to facilitate workability and to act on color, image formation. As such a compound, dyes such as leuco-based crystal violet, methyl violet, ethyl violet, phenyl tribromo methyl sulfone, p-nitro phenyl tribromo methyl sulfone, and the like developed by acid generation may be used. Examples of the adhesion promoter include benzo imidazole, benzthiazole, benzthioxazole, benzotriazole, 2-mercapto benzthiazole, and 20 mercapto benzoimidazole. In addition, thermal polymerization inhibitors such as hydroquinone, p-phenoxyphenol, 2-hydroxyoxy benzophenone, and the like may be used to prevent storage polymerization of the photosensitive polymer layer and to prevent thermal polymerization during drying or lamination of the coating solution.

Such components may be used in combination within a conventional range, and are not particularly limited except that the photoinitiator is not included in the semi-light-curing layer.

<Example>

Photopolymerization layer and photopolymerization part

Polymer binder: 50% by weight copolymer of (meth) acrylic acid and (meth) acrylate

Photoinitiator: Benzophenone 2% by weight

 4,4 '-(bisdiethylamino) benzophenone 1% by weight

Luco Crystal Violet 1% by weight

0.5% by weight of toluenesulfonic acid monohydrate

0.5% of diamond green GH

Photopolymerizable monomer: 10% by weight polyethylene glycol dimethacrylate

10% by weight polypropylene glycol 400 diacrylate

10% by weight of the compound represented by the following formula

Where R is H or CH ₃ and m is an integer from 5 to 10

Plasticizer: Trifenic phosphate 1% by weight

Solvent: 14% by weight of methyl ethyl ketone

Non-light polymerization part

Polymer binder: 55% by weight copolymer of (meth) acrylic acid and (meth) acrylate

Photopolymerizable monomer: 10% by weight polyethylene glycol dimethacrylate

10% by weight polypropylene glycol 400 diacrylate

10% by weight of the compound represented by the following formula

Where R is H or CH ₃ and m is an integer from 5 to 10

Plasticizer: Trifenic phosphate 1% by weight

Solvent: 14% by weight of methyl ethyl ketone

Photosensitive polymer layer

A photopolymer layer having a thickness of 5 to 95 µm having the above-described configuration is formed, and the non-light-polymerizing section having the above-described configuration is included in a width smaller than the interval between printed wirings to be formed, and the non-polymerizing portion and the above-described configuration The branch was alternately arranged to form a semi-light polymerization layer having a thickness of 5 to 95 µm. These semi-polymerizable layers and the photopolymerized layers are respectively thermally compressed to form a photosensitive polymer layer having a final thickness of 100 µm, or a semi-photopolymerizable layer is formed, and the photopolymer layer is discharged and laminated thereon to obtain a final photosensitive polymer having a final thickness of 100 µm. Form a layer.

2) dry film

The dry film is a 5 to 100㎛ photosensitive polymer layer, the protective layer (protect film or cover film) uses a resin having important characteristics such as transmittance and static electricity, and the base film (base film) also serves to protect the photosensitive polymer layer Lay up so that you can.

As the support layer, a polyester film such as a polyethylene terephthalate film having a thickness of 15 to 30 µm or a polyethylene film is widely used, and a polyester transparent film is mainly used as a protective layer.

3) formation of circuit wiring

Examples of the photoresist in the present invention include liquid photoresist (LPR), electrodeposition resist (ED), etc. in addition to the dry film (DFR) as in the present invention. In addition, a copper clad laminated substrate (CCL) may be preferably used as the substrate including the conductive layer of the present invention.

The support layer is removed from the dry film and laminated on the copper-clad laminate substrate. The work film is placed on top of the dry film and exposed. At this time, the part which does not form a circuit wiring is exposed, and the part exposed by alkaline solution, such as aqueous sodium carbonate solution, is developed and removed.

The copper foil exposed to the portions other than the portion where the dry film is laminated is etched by treating with an acid solution such as copper chloride or iron chloride. At this time, Cu ²⁺ ions in the etching solution, which is copper, are used to etch the Cu ⁺ ions and supply an oxidizing agent, thereby regenerating the unstable Cu ⁺ ions into Cu ² ions capable of attacking Cu.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, the present invention provides a photosensitive polymer layer and a dry film which allow the non-photosynthetic portion to remain even in a portion removed in the exposure and development process including the non-photopolymerization portion. In addition, the present invention provides a printed circuit board including a fine circuit wiring formed therefrom and a method for forming a fine circuit wiring having a small difference between an upper width and a lower width by improving vertical orientation during conductive etching due to the remaining non-photosynthetic portion. to provide. In addition, the present invention has a spacing between circuit wirings of 30 µm or less, which is difficult to form by a conventional subtractive method, and forms a fine circuit wiring of 30/30 or less in the width of the circuit wiring / the spacing between the circuit wirings. A method and a printed circuit board including such fine circuit wiring are provided. In addition, the present invention can form a fine circuit wiring to increase the frequency characteristics of the circuit wiring to improve the signal transmission efficiency, to eliminate the need for additional equipment, to form a circuit wiring that can use the existing line and the existing method A method and a printed circuit board including such circuit wiring are provided.

Claims (15)

The photosensitive polymer layer includes a photopolymerization layer and a semi-photopolymerization layer, The photopolymerization layer, Polymeric binders; A photoinitiator which, when irradiated with light, imparts chemical activity in a wavelength band where the light absorption of the polymer binder is low; And When the light is irradiated is a layer containing a photopolymerizable monomer to bind the polymer binders, The semi-light-curing layer includes a light-polymerizing portion and a non-light-polymerizing portion, The photopolymerization unit is the polymer binder; The photoinitiator; And the photopolymerizable monomer, The non-photopolymerization portion is the polymer binder; And a photosensitive polymer layer comprising the photopolymerization monomer. The method according to claim 1, The photosensitive polymer layer and the photopolymerization portion and the non-photopolymerization portion are alternately disposed. The method according to claim 1, The semi-photopolymerizable layer has a thickness of 0.1 to 10 times the thickness of the photopolymerizable layer. The method according to claim 1, Photosensitive polymer layer having a thickness of 5 to 100㎛ The method according to claim 4, Photosensitive polymer layer comprising the semi-light polymerization layer having a thickness of 0.45 to 91㎛ Dry film comprising the photosensitive polymer layer, the support layer and the protective layer according to claim 1 The method according to claim 6, A dry film in which the photopolymerization unit and the non-photopolymerization unit are alternately arranged; The method according to claim 6, The thickness of the semi-light-polymer layer is 0.1 to 10 times the thickness of the photo-polymer layer The method according to claim 6, Dry film comprising a photosensitive polymer layer having a thickness of 5 to 100㎛ The method according to claim 9, Dry film containing the semi-light-curing layer having a thickness of 0.45 to 91㎛ (a) laminating the dry film of claim 6 on a substrate comprising a conductive layer; (b) removing a portion of the dry film to correspond to the wiring pattern by exposure and development; And (c) a method of forming a circuit wiring comprising removing and removing a portion of the dry film to expose and expose the conductive layer. The method according to claim 11, In the step (b), the method for forming circuit wiring remaining on the conductive layer without removing the non-light-polymerization part included in a part of the removed dry film delete Printed circuit board comprising fine circuit wiring formed by the method of forming a circuit wiring of claim 11 The method according to claim 14, Printed circuit board having a spacing between the fine circuit wiring of 10 to 30㎛

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