TWI808703B - Photosensitive laminate, and method of manufacturing a circuit board using the same - Google Patents

Abstract

The present disclosure relates to a photosensitive laminate comprising: a barrier layer having a haze of 2% or less; and a photosensitive resin layer which comprises a photopolymerizable compound containing a phthalate derivative, and a binder resin, wherein bubbles having a diameter of less than 1 μm are present at 5 bubbles/mm ²or less within the photosensitive resin layer, and a method of manufacturing the circuit board.

Description

Photosensitive laminate and method for preparing circuit board using same

[CROSS-REFERENCE TO RELATED APPLICATIONS]

This application claims the benefit of Korean Patent Application No. 10-2021-0042141 filed with the Korean Intellectual Property Office on March 31, 2021, the content of which is incorporated herein by reference in its entirety.

The invention relates to a photosensitive laminate and a method for preparing a circuit board.

The photosensitive resin composition is used in the form of a dry film photoresist (DFR) for a printed circuit board (PCB) or a lead frame, a liquid photoresist ink, and the like.

Recently, along with the trend toward lighter, thinner, shorter, and more compact semiconductor devices and multilevel packaging, high-density circuit boards are required, and processes using ultra-high pressure mercury lamps or laser direct exposure or methods of preparing circuit boards using photosensitive laminations including support films and photosensitive resin layers and similar processes are also widely used.

Therefore, there is a continuing need to develop a method and process for achieving high density and sensitivity while ensuring high reliability and capable of forming finer wiring. [Prior Art Literature] [Patent Document] (Patent Document 1) Japanese Unexamined Patent Application Publication No. 2006-106287 (published on April 20, 2006)

An object of the present invention is to provide a photosensitive laminate that can reduce defects in fine wiring formation, ensure high reliability during development, and form high-density circuits.

Another object of the present invention is to provide a method for preparing a circuit board using a photosensitive laminate.

According to one aspect of the present invention, there is provided a photosensitive laminate comprising: a barrier layer having a haze of 2% or less; and a photosensitive resin layer including a photopolymerizable compound and a binder resin, the photopolymerizable compound containing phthalate derivatives, wherein bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2.

According to another aspect of the present invention, a method of preparing a circuit board using a photosensitive laminate may be provided.

Hereinafter, a photosensitive laminate and a method of manufacturing a circuit board according to certain embodiments of the present invention will be described in more detail.

As used herein, the weight average molecular weight means the weight average molecular weight measured by the GPC method relative to polystyrene. In the process of determining the weight-average molecular weight measured by the GPC method relative to polystyrene, commonly known analytical devices, detectors such as refractive index detectors, and analytical columns can be used. Common conditions for temperature, solvent, and flow rate can be used.

A specific example of the measurement conditions is as follows: an alkaline developable binder resin was dissolved in tetrahydrofuran so as to have a concentration of 1.0 (w/w)% in THF (about 0.5 (w/w)% in terms of solid content), filtered using a syringe filter having a pore size of 0.45 μm, and then 20 microliters were injected into the GPC. The mobile phase of GPC used tetrahydrofuran (THF) fed at a flow rate of 1.0 ml/min. The column was connected in series with one Agilent PLgel 5 μm Guard (7.5×50 mm) and two Agilent PLgel 5 μm Mixed D (7.5×300 mm), Agilent 1260 Infinity II system, RI detector was used as a detector, and the measurement was performed at 40°C.

As shown below, polystyrene standard samples (STD A, B, C, D) in which polystyrenes having different molecular weights were dissolved in tetrahydrofuran at a concentration of 0.1 (w/w)% were filtered with a syringe filter having a pore size of 0.45 μm, and then injected into a GPC, and the value of the weight average molecular weight (Mw) of the alkaline developable binder resin was determined using the formed calibration curve. STD A (Mp): 791,000 / 27,810 / 945 STD B (Mp): 282,000 / 10,700 / 580 STD C (Mp): 126,000 / 4,430 / 370 STD D (Mp): 51,200 / 1,920 / 162

As used herein, the term "(photo)cured product" or "(photo)cured" means not only the case where components having curable or crosslinkable unsaturated groups in the chemical structure are completely cured, crosslinked or polymerized, but also the case where such components are partially cured, crosslinked or polymerized.

According to another embodiment of the present invention, there may be provided a photosensitive laminate comprising: a barrier layer having a haze of 2% or less; and a photosensitive resin layer including a photopolymerizable compound containing a phthalate derivative, wherein bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2.

The present inventor has newly developed a photosensitive laminate, comprising a barrier layer with a turbidity of 2% or less and a photosensitive resin layer, wherein bubbles with a diameter of less than 1 micron or 0.001 micron or greater than 0.001 micron and less than 1 micron exist at 5 bubbles/mm2 or less than 5 bubbles/mm2, and found through experiments that when such a photosensitive laminate is used in the manufacturing process of a circuit board, it is possible to achieve high sensitivity to exposure, increase reliability during development, and achieve high reliability while ensuring high reliability. density and sensitivity, and enables the formation of finer wiring, thereby completing the present invention.

The present inventors have found that it is possible to achieve excellent circuit pattern resolution in a dry film photoresist fabrication process using a photosensitive stack by including a barrier layer having a haze of 2% or less and having excellent optical properties. Specifically, the present inventors have found that by including a barrier layer having a haze of 2% or less, the barrier layer can serve as an oxygen barrier film that blocks oxygen radical reactions, thereby minimizing the formation of foreign substances or air bubbles in the photosensitive resin layer, and improving the resolution and reliability of the finally prepared dry film photoresist, thereby completing the present invention.

In particular, in the photosensitive stack of one embodiment, the barrier layer may have a haze of 2% or less, 0.001% or greater and 2% or less, or 0.1% or greater and 2% or less.

The method for measuring the turbidity is not particularly limited, but it can be measured using a HAZE METER (model name: NDH7000, Nippon Denshoku Corp.) according to the measurement method of ASTM D1003.

The thickness of the barrier layer to be measured for turbidity may be 0.1 micron to 10 micron or 1 micron to 3 micron. When the thickness of the barrier layer increases or decreases by a certain value, the physical properties measured from the barrier layer may also change by a certain value.

When the turbidity of the barrier layer exceeds 2%, there may be a problem of degradation of circuit properties and resolution.

In one embodiment of the photosensitive laminate, the barrier layer may have a thickness of 10 cm3/m2/day or less, 5 cm3/m2/day or less than 5 cm3/m2/day, 4 cm3/m2/day or less than 4 cm3/m2/day, 0.01 cm3/m2/day or greater than 0.01 cm3/m2/day day and 10 cubic centimeters/square meter/day or less than 10 cubic centimeters/square meter/day, 0.01 cubic centimeters/square meter/day or greater than 0.01 cubic centimeters/square meter/day and 5 cubic centimeters/square meter/day or less than 5 cubic centimeters/square meter/day or 0.01 cubic centimeters/square meter/day or greater than 0.01 cubic centimeters/square meter/day and 4 cubic centimeters/square m/day or an oxygen permeability of less than 4 cm3/m2/day. The method for measuring the oxygen permeability is not particularly limited, but for example, it can be measured using OX-Tran (model 2/61, Mocon Inc.) according to the measurement method of ASTM F1927.

The thickness of the barrier layer to be measured for oxygen permeability can be 0.1 micron to 10 micron or 1 micron to 3 micron. When the thickness of the barrier layer increases or decreases by a certain value, the physical properties measured from the barrier layer may also change by a certain value.

Since the barrier layer has an oxygen permeability of 10 cm3/m2/day or less than 10 cm3/m2/day, the barrier layer can serve as an oxygen barrier film that blocks oxygen free radical reactions, thereby minimizing the formation of foreign substances or bubbles in the photosensitive resin layer, and improving the resolution and reliability of the final dry film photoresist.

The barrier layer may be formed of a composition for forming a barrier layer, and the composition for forming a barrier layer may include a polyvinyl alcohol resin.

That is, the barrier layer may comprise a weight average molecular weight of 5,000 g/mol to 1,000,000 g/mol, 7,000 g/mol to 750,000 g/mol, 7,000 g/mol to 700,000 g/mol, 7,000 g/mol to 50,000 g/mol, 7,000 g/mol to 30, 000 grams/mole or 10,000 grams/mole to 30,000 grams/mole of polyvinyl alcohol resin. Since the barrier layer includes polyvinyl alcohol resin with a weight average molecular weight of 10,000 g/mol to 1,000,000 g/mol, the haze of the barrier layer may be 2% or less.

More specifically, the polyvinyl alcohol resin may have a viscosity of 1.0 centipoise to 10.0 centipoise, 3.0 centipoise to 10.0 centipoise, 3.0 centipoise to 5.0 centipoise. Since the viscosity of the polyvinyl alcohol resin satisfies 1.0 centipoise to 10.0 centipoise, the turbidity of the barrier layer can satisfy 2% or less than 2%.

In addition, the composition for forming the barrier layer may include a high boiling point solvent having a boiling point of 115°C or higher.

Examples of the high-boiling solvent having a boiling point of 115° C. or higher may include butanol, dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, butyl capitol, butyl cellosolve, methyl cellosolve, butyl acetate, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl ether, Dipropylene glycol dimethyl ether, 3-methoxymethyl propionate, 3-ethoxy ethyl propionate, propylene glycol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate (PGMEA) and a mixed solvent of one or more thereof.

Specifically, based on 100 parts by weight of the polyvinyl alcohol resin, the composition for forming the barrier layer may include 60 parts by weight or more, 60 parts by weight or more and 200 parts by weight or less, 70 parts by weight or more and 200 parts by weight or less, 80 parts by weight or more than 80 parts by weight and 200 parts by weight or less, 80 parts by weight or more than 80 parts by weight and 1 00 parts by weight or less or 90 parts by weight or more and 100 parts by weight or less of a high boiling point solvent having a boiling point of 115°C or higher.

Since the composition for forming the barrier layer contains 60 parts by weight or more of a high-boiling solvent having a boiling point of 115° C. or higher based on 100 parts by weight of the polyvinyl alcohol resin, the turbidity of the barrier layer may be 2% or less, and when the composition for forming the barrier layer contains less than 60 parts by weight of a high-boiling solvent having a boiling point of 115° C. or higher based on 100 parts by weight of the polyvinyl alcohol resin. Technical problem with sharp increase in turbidity.

The thicknesses of the barrier layer and the photosensitive resin layer in the photosensitive laminate are not particularly limited, but as a specific example, the barrier layer may have a thickness of 0.1 micron to 10 microns or 1 micron to 3 microns, and the thickness of the photosensitive resin layer may be 1 micron to 100 microns or 5 microns to 50 microns.

The photosensitive stack of one embodiment may further include a supporting substrate formed on the barrier layer and having a thickness of 1 μm to 100 μm. As a specific example, the supporting substrate may have a thickness of 1 micron to 100 microns or 5 microns to 50 microns. That is, the photosensitive laminate of one embodiment may have a laminated structure in which a support substrate, a barrier layer, and a photosensitive resin layer are sequentially laminated. The support substrate acts as a carrier during the process of making the photosensitive stack. In addition, depending on the semiconductor manufacturing process or the final product to be coated with the photosensitive stack, the support substrate may or may not be included in the photosensitive stack as needed.

In addition, the photosensitive laminate in one embodiment may further include a release layer formed on the photosensitive resin layer and having a thickness of 0.01 μm to 1 meter. As a specific example, the release layer may have a thickness of 0.01 microns to 1 meter, 1 micron to 100 microns, or 5 microns to 50 microns. That is, the photosensitive laminate of one embodiment may have a laminated structure in which a support substrate, a barrier layer, a photosensitive resin layer, and a release layer are sequentially laminated.

As described above, during the dry film photoresist fabrication process using photosensitive lamination, the support substrate and release layer may be removed. Since the photosensitive stack includes a barrier layer with a haze of 2% or less, the resulting dry film photoresist can achieve excellent reliability and resolution even when the support substrate is removed.

Specifically, in the photosensitive laminate of one embodiment, since bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at a rate of 5 bubbles/mm2 or less than 5 bubbles/mm2 or the bubbles are substantially absent, only a barrier layer with a turbidity of 2% or less is formed, which is still applicable to the semiconductor manufacturing process, so that even in the case of a thinner thickness, it is possible to achieve the same level or higher level of reliability and sensitivity than conventionally known photosensitive laminates.

In addition, since the photosensitive laminate of one embodiment is applicable to a semiconductor manufacturing process in a state where a supporting substrate such as a polyethylene terephthalate (PET) film is peeled off, separate peeling of the supporting substrate in the semiconductor manufacturing process can be eliminated. In addition, in a structure in which support substrates such as polyethylene terephthalate (PET) films are interleaved or laminated, it is possible to improve points where support substrates have limitations on optical characteristics, exposure, development, sensitivity realization, and the like.

Meanwhile, the present inventors have continuously conducted research and development to remove traces of fine air bubbles or fine by-products that may occur due to various reasons in the manufacturing process. As described above, in the method for producing a photosensitive laminate described later, the present inventors have used a resin composition comprising: a mixed solvent containing a high-boiling solvent having a boiling point of 115° C. or higher and a low-boiling solvent having a boiling point of 100° C. or lower; a binder resin; a photopolymerizable compound containing a phthalate derivative; /mm2 or 3 bubbles/mm2 or less than 3 bubbles/mm2 exist in the photosensitive resin layer.

In addition, in the preparation method of the photosensitive laminate, in addition to using a mixed solvent containing a high-boiling solvent having a boiling point of 115°C or higher and a low-boiling solvent having a boiling point of 100°C or lower, the volume of fine air bubbles formed in the photosensitive resin layer can be significantly reduced or substantially absent by adjusting the drying rate and/or drying temperature.

Meanwhile, bubbles with a diameter of less than 1 micron may exist in the photosensitive resin layer at or below 5 bubbles/mm2 or 3 bubbles/mm2 or less. In particular, air bubbles having a diameter of less than 1 micrometer may exist in a trace amount or substantially not exist on the opposite surface of the interface between the support substrate and the photosensitive resin layer or toward the outer surface of the photosensitive resin layer. Within 50% of the total thickness of the photosensitive resin layer from the opposite surface of the interface between the barrier layer and the photosensitive resin layer, bubbles with a diameter of less than 1 μm may exist at or below 3 bubbles/mm2.

Since air bubbles with a diameter of less than 1 micrometer may exist in trace amounts or substantially not exist on the opposite surface of the interface between the barrier layer and the photosensitive resin layer or toward the outer surface of the photosensitive resin layer, it can enhance reliability during development, enable formation of high-density circuits and reduce defects in fine wiring formation, thereby enabling high sensitivity to exposure and improving production yield of high-density printed circuit boards when using a photosensitive laminate.

In addition, as described above, the photosensitive laminate may not only contain traces or substantially no bubbles with a diameter of less than 1 micron, but also may not contain bubbles with a diameter of 1 micron or more and 5 microns or less.

When a circuit board is prepared by using a photosensitive laminate in which air bubbles having a diameter of less than 1 micron exist in a trace amount in a photosensitive resin layer as described above, high density and sensitivity are achieved while ensuring high reliability, and finer wiring can be formed.

More specifically, even if the photosensitive resin layer is exposed to ultraviolet rays and developed with an alkaline solution, defects may not appear over the entire area, or even if they appear, they may appear in an extremely small amount. Specifically, defects do not substantially exist on the upper surface of the photosensitive resin layer, and after development, fine-sized defects may exist on the lower surface or inside of the photosensitive resin layer.

Specifically, after exposing the photosensitive resin layer with ultraviolet rays and developing it with an alkaline solution, defects having a cross-sectional diameter of 0.3 μm to 4 μm or 0.5 μm or greater than 0.5 μm and 3 μm or less may be observed at 3 defects/mm2 or less or 1 defect/mm2 or less or may be substantially absent. The cross-sectional diameter of a defect may be defined as the largest diameter among defect diameters defined in a cross-section along one direction on the photosensitive resin layer.

The conditions of exposure and development are not particularly limited. For example, the photosensitive stack is irradiated with light wavelengths in the range of 340 nm to 420 nm, and the exposure can be performed for 1 minute to 60 minutes at the amount of energy at which the number of remaining steps becomes 15 steps measured using a 41-step tablet from Stouffer Graphic Arts Equipment. In addition, development can be performed with an alkaline aqueous solution such as Na ₂ CO ₃ at a concentration of 0.1% by weight to 3.0% by weight by a method such as a spray spray method.

Furthermore, when using photosensitive stacks, higher densities and sensitivities can be achieved even at lower energies. More specifically, the photosensitive stack is irradiated with a wavelength of light in the range of 340 nm to 420 nm, and using a 41-step exposure meter from Stouffer Graphic Arts Equipment, the measured amount of energy at which the number of steps of the remaining steps becomes 15 steps can be 300 mJ/cm2 or less or 100 mJ/cm2 or less, and the resolution after development can be Achieved at 15 microns or less, or 10 microns or less, or 7 microns or less, or 5 microns or less.

Meanwhile, the characteristics of the photosensitive laminate or the structural characteristics in which bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at or below 5 bubbles/mm2 are attributable to the above-described manufacturing method and are attributable to the properties of the photosensitive resin layer.

Specifically, the photosensitive resin layer may include an alkaline developable binder resin containing a carboxyl group. Alkaline developable binders contain at least one carboxyl group in the molecule and can react with a base during the development process.

Specific examples of the alkali-developable binder are not limited, but may be polymers or copolymers containing at least one repeating unit selected from the group consisting of a repeating unit represented by the following Chemical Formula 4, a repeating unit represented by the following Chemical Formula 5, and a repeating unit represented by the following Chemical Formula 6. [chemical formula 4] Wherein, in Chemical Formula 4, R ₃ is hydrogen or an alkyl group having 1 to 10 carbon atoms, [Chemical Formula 5] Wherein, in Chemical Formula 5, R ₄ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₅ is an alkyl group having 1 to 10 carbon atoms [Chemical Formula 6] Wherein, in Chemical Formula 6, Ar is an aryl group having 6 to 20 carbon atoms.

In Chemical Formula 4 to Chemical Formula 6, _R3 and _R4 are the same or different from each other and each independently is hydrogen or an alkyl group having 1 to 10 carbon atoms, _R5 is an alkyl group having 1 to 10 carbon atoms, and Ar is an aryl group having 6 to 20 carbon atoms.

In Chemical Formula 2 to Chemical Formula 4, _R3 and _R4 are the same or different from each other and may each independently be any of hydrogen or an alkyl group having 1 to 10 carbon atoms, wherein specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group.

R ₅ is an alkyl group having 1 to 10 carbon atoms, and specific examples of the alkyl group having 1 to 10 carbon atoms include methyl.

Ar is an aryl group having 6 to 20 carbon atoms, and specific examples of the aryl group having 6 to 20 carbon atoms include phenyl.

The repeating unit represented by Chemical Formula 4 may be a repeating unit derived from a monomer represented by the following Chemical Formula 4-1. [chemical formula 4-1] Wherein, in Chemical Formula 4-1, R ₃ is hydrogen or an alkyl group having 1 to 10 carbon atoms. In Chemical Formula 4-1, the contents regarding R ₃ are the same as those described in Chemical Formula 4 above. Specific examples of the monomer represented by Chemical Formula 4-1 include acrylic acid (AA) and methacrylic acid (MAA).

The repeating unit represented by Chemical Formula 5 may be a repeating unit derived from a monomer represented by the following Chemical Formula 5-1. [chemical formula 5-1] Wherein, in Chemical Formula 5-1, R ₄ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₅ is an alkyl group having 1 to 10 carbon atoms. In Chemical Formula 5-1, R ₄ and R ₅ are the same as described above in Chemical Formula 5. Specific examples of the monomer represented by Chemical Formula 5-1 include methyl methacrylate (MMA) and butyl acrylate (BA).

The repeating unit represented by Chemical Formula 6 may be a repeating unit derived from a monomer represented by the following Chemical Formula 6-1. [chemical formula 6-1] Wherein, in Chemical Formula 6-1, Ar is an aryl group having 6 to 20 carbon atoms. In Chemical Formula 6-1, the contents regarding Ar are the same as those described in Chemical Formula 4 above. A specific example of the monomer represented by Chemical Formula 6-1 may include styrene (SM).

Meanwhile, the binder resin may serve as a substrate for the photosensitive resin layer, and thus must have a minimum molecular weight. For example, it can have 20,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 250,000 grams/mole, 30,000 grams/mole to 200,000 grams/mole or 30,000 grams/mole to 150 ,000 g/mole weight average molecular weight.

In addition, the binder resin should have at least a certain level of heat resistance, and thus may have a glass transition temperature of 20°C to 150°C, 50°C to 150°C, 70°C to 150°C, 70°C to 120°C, 80°C to 120°C, or 100°C to 120°C.

In addition, the binder resin may have 100 mgKOH/g to 300 mgKOH/g, 120 mgKOH/g to 300 mgKOH/g, 120 mgKOH/g to 250 mgKOH/g, 120 mgKOH/g to 200 mgKOH/g, or 150 mgKOH/g to 200 mgKOH/g in consideration of the developability of the photosensitive resin layer. Acid value below mgKOH/g.

Meanwhile, the binder resin may contain two or more alkali-developable binders having different types or different properties. Specifically, the binder resin may include a first alkali-developable binder resin and a second alkali-developable binder resin.

The first alkaline developable binder resin and the second alkaline developable binder resin can have 20,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 250,000 grams/mole, 30,000 grams/mole to 200,000 grams/mole, or 3 A weight average molecular weight of 0,000 g/mol to 150,000 g/mol and a glass transition temperature of 20°C to 150°C, 50°C to 150°C, 70°C to 150°C, 70°C to 120°C, 80°C to 120°C, or 100°C to 120°C. These may each have a different weight average molecular weight, glass transition temperature or acid number.

For example, the first alkali-developable binder resin may have an acid value of not less than 140 mgKOH/g and not more than 160 mgKOH/g. Also, the second alkali-developable binder resin may have an acid value of not less than 160 mgKOH/g and not more than 200 mgKOH/g.

In addition, the ratio of the glass transition temperature of the first alkaline developable binder resin to the second alkaline developable binder resin may be 1:1.5 or greater than 1:1.5 and 1:5 or less than 1:5, 1:1.5 or greater than 1:1.5 and 1:3 or less, 1:1.5 or greater than 1:1.5 and 1:2 or less than 1:2, 1:1.5 or greater than 1:1.5 and 1:1.8 or less than 1:1.8, 1:1.5 or greater 1.5 or greater than 1:1.5 and 1:75 or less than 1:75 or 1:1.6 or greater than 1:1.6 and 1:7 or less than 1:7.

In addition, the acid value ratio of the first alkaline-developable binder resin to the second alkaline-developable binder resin may be 1:1.01 or greater than 1:1.01 and 1:1.5 or less than 1:1.5, 1:1.1 or greater than 1:1.1 and 1:1.5 or less than 1:1.5, 1:1.25 or greater than 1:1.25 and 1:1.5 or less than 1:1.5 or 1:1.4 or greater than 1:1.4 and 1 :1.5 or less than 1:1.5.

Meanwhile, the photosensitive resin layer may include a cross-linked copolymer between a binder resin and a photopolymerizable compound containing a phthalate derivative.

The photopolymerizable compound containing a phthalate derivative may serve as a crosslinking agent for increasing the mechanical strength of the photosensitive resin layer and the like or for increasing resistance to a developer and imparting flexibility to a cured film.

The phthalate derivative may comprise a central group derived from a phthalate and a reactive functional group bonded thereto. The phthalate derivative may contain 1 or more, or 2 or more, or 3 or more, or 10 or less reactive functional groups. Specific examples of the reactive functional group may include a halogen, a hydroxyl group, an ether bond (-O-), an ester bond (-COO- or O-CO-), an amide bond (-NHCO- or CONH-), a vinyl group, a (meth)acrylate group, or an aryl group. Since the phthalate derivative has the above-mentioned structure, resistance to plating solutions and etching solutions may be enhanced and fine patterns may be more easily realized.

The weight average molecular weight of the phthalate derivative is not particularly limited, but for example, it may have a weight average of 50 g/mol to 10,000 g/mol, or 70 g/mol to 5,000 g/mol, or 80 g/mol to 1,200 g/mol, or 100 g/mol to 1,000 g/mol, or 150 g/mol to 500 g/mol. molecular weight.

Meanwhile, specific examples of phthalate derivatives may include compounds of Chemical Formula 1 below. [chemical formula 1] Wherein, in Chemical Formula 1, R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and the aliphatic hydrocarbon group may optionally include a halogen atom, a hydroxyl group, an ether bond (-O-), an ester bond (-COO- or O-CO-), an amide bond (-NHCO- or CONH-), a (meth)acrylate group or an aryl group.

In addition, more specific examples of the phthalate derivative or the compound of Chemical Formula 1 may include the compound of the following Chemical Formula 2 or the compound of the following Chemical Formula 3: [Chemical Formula 2] [chemical formula 3]

Meanwhile, the content of the photopolymerizable compound containing phthalate derivatives may be adjusted according to specific uses or characteristics of the photosensitive resin layer. For example, based on 100 parts by weight of the alkaline developable binder resin, 1 to 80 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight, 1 to 10 parts by weight, 2 to 50 parts by weight, 2 to 30 parts by weight, 2 to 20 parts by weight, 2 to 10 parts by weight, 5 to 50 parts by weight, 5 to 30 parts by weight , 5 parts by weight to 20 parts by weight, 5 parts by weight to 10 parts by weight of photopolymerizable compounds containing phthalate derivatives.

That is, since the photosensitive laminate of Example is used by mixing two or more types of solvents having different boiling points as described in the production method described later, and depending on the selection of the photopolymerizable compound containing phthalate derivatives, fine air bubbles may exist in a trace amount or substantially not exist in the photosensitive resin layer.

In particular, due to the structure and characteristics of the photopolymerizable compound containing a phthalate derivative, air bubbles having a diameter of 1 micrometer or less can exist in a trace amount in the photosensitive resin layer, thereby making it possible to provide a photosensitive laminate that can reduce defects in fine wiring formation, can ensure high reliability during development, and thus enables the formation of high-density circuits.

Meanwhile, the photopolymerizable compound may further include monofunctional or polyfunctional (meth)acrylate monomers or oligomers. As the photopolymerizable compound, generally known monofunctional or polyfunctional (meth)acrylate monomers or oligomers can be used.

Examples of photopolymerizable compounds that may be additionally used are not particularly limited, but may include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexaneethylene glycol di(meth)acrylate, trimethylol Propane Tri(meth)acrylate, Trimethylolpropane Triacrylate, Glycerol Di(meth)acrylate, Neopentylthritol Di(meth)acrylate, Neopentylthritol Tri(meth)acrylate, Dipentylthritol Penta(meth)acrylate, 2,2-Bis(4-methacryloxydiethoxyphenyl)propane, 2,2-Bis(4-methacryloxypolyethoxyphenyl)propane, 2-Hydroxy-3-methacryloxypropane (meth)acrylate esters, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, diglycidyl phthalate di(meth)acrylate, glycerol polyglycidyl ether poly(meth)acrylate, polyfunctional (meth)acrylates containing urethane groups, and the like.

The content of the monofunctional (meth)acrylate compound or the polyfunctional (meth)acrylate compound can be adjusted according to the specific use or characteristics of the photosensitive resin layer. For example, according to the 100 weights of phthalate derivatives, optical concentrated compounds can include 50 to 1500 weights, 100 weights to 1500 weights, 110 to 1500 weights, 110 to 1,000 weights, 110 weights to 900 weights, 50 to 500 weights. The volume of the single -off -level (methyl) acrylic compound or multi -official (methyl) acrylic compound.

Meanwhile, various plastic films can be used as the substrate film, and examples thereof include one or more plastic films selected from the group consisting of acrylic film, polyethylene terephthalate (PET) film, triacetyl cellulose (TAC) film, polynorbornene (PNB) film, cycloolefin polymer (COP) film, and polycarbonate (polycarbonate) film. ; PC) film.

Meanwhile, the release layer may contain a protective film.

That is, the photosensitive laminate may further include a protective film formed so as to face the supporting substrate at the center of the photosensitive resin layer. The protective film serves as a protective cover that prevents damage to the resist during handling and protects the photosensitive resin layer from foreign substances such as dust, and may be laminated on the back side of the photosensitive resin layer on which the barrier layer is not formed.

The protective film is used to protect the photosensitive resin layer from external influences, and it needs to have proper separation and adhesiveness so that it can be easily peeled off when the dry film photoresist is applied to post-process, and it is not released during storage and distribution.

Various plastic films can be used as the protective film, and examples thereof include at least one plastic film selected from the group consisting of acrylic film, polyethylene (PE) film, polyethylene terephthalate (PET) film, triacetyl cellulose (TAC) film, polynorbornene (PNB) film, cycloolefin polymer (COP) film, and polycarbonate (PC) film. The thickness of the protective film is not particularly limited, but can be freely adjusted within, for example, 0.01 micron to 1 meter.

According to another embodiment of the present invention, there may be provided a method for preparing a photosensitive laminate, the method comprising the steps of: coating and drying a resin composition on a barrier layer, the resin composition comprising: a mixed solvent containing a high-boiling solvent having a boiling point of 115° C. or higher and a low-boiling solvent having a boiling point of 100° C. or lower; a binder resin; a photopolymerizable compound containing a phthalate derivative; and a photoinitiator.

Depending on the method of preparation, the photosensitive laminate described above in one embodiment may be provided.

As described above, the photosensitive laminate includes: a barrier layer having a haze of 2% or less; and a photosensitive resin layer including a photopolymerizable compound containing a phthalate derivative, wherein bubbles having a diameter of less than 1 micrometer exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2.

During the process of forming the photosensitive resin layer, bubbles having a diameter of less than 1 micron may be formed in the photosensitive resin layer due to reasons such as bubbles generated during a solution preparation process of the photosensitive resin composition or a solution drying process of the composition. In the method for preparing a photosensitive laminate, since a mixed solvent comprising a high-boiling solvent having a boiling point of 115° C. or higher and a low-boiling solvent having a boiling point of 100° C. or lower is used, it is possible to delay the evaporation time of the solution of the photosensitive resin composition and prevent bubbles from being trapped in the resin layer. Thus, bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2.

More specifically, bubbles with a diameter of less than 1 micrometer may exist in the photosensitive resin layer at 5 bubbles/mm2 or less or 3 bubbles/mm2 or less.

In addition, within 50% of the total thickness of the photosensitive resin layer from the opposite surface of the interface between the barrier layer and the photosensitive resin layer, bubbles having a diameter of less than 1 μm may exist at or below 3 bubbles/mm2.

Since air bubbles with a diameter of less than 1 micrometer may exist in trace amounts or substantially not exist on the opposite surface of the interface between the barrier substrate and the photosensitive resin layer or toward the outer surface of the photosensitive resin layer, it can enhance reliability during development, enable formation of high-density circuits and reduce defects in formation of fine wiring, whereby high sensitivity to exposure can be achieved when a photosensitive laminate is used, and production yield of high-density printed circuit boards can be improved.

As described above, a high boiling point solvent having a boiling point of 115° C. or greater may be used to delay the evaporation time of the liquid components of the photosensitive resin composition and prevent air bubbles from being trapped in the resin layer. Thereby, bubbles with a diameter of less than 1 micron may exist in the photosensitive resin layer at or below 5 bubbles/mm2.

The mixed solvent may contain a high boiling point solvent having a boiling point of 115°C or higher in a certain amount or more. For example, relative to 100 parts by weight of the mixed solvent, the content of the high boiling point solvent having a boiling point of 115° C. or higher may be 3 parts by weight or greater, or 5 parts by weight or greater than 5 parts by weight, or 3 to 50 parts by weight, or 5 to 40 parts by weight.

Since a low boiling point solvent having a boiling point of 100°C or lower is used together with a high boiling point solvent having a boiling point of 115°C or higher, the dissolving ability of the photosensitive resin composition can be enhanced.

The mixed solvent may contain a low boiling point solvent having a boiling point of 100°C or lower in a higher content than a high boiling point solvent having a boiling point of 115°C or higher.

More specifically, the mixed solvent may contain a high boiling point solvent with a boiling point of 115°C or higher: a low boiling point solvent with a boiling point of 100°C or lower in a weight ratio of 1:2 to 1:18, or 1:3 to 1:15, or 1:5 to 1:10, or 1:6 to 1:8. Since the above content contains a high boiling point solvent with a boiling point of 115° C. or higher than 115° C. and a low boiling point solvent with a boiling point of 100° C. or lower than 100° C., the solubility of the photosensitive resin composition can be enhanced.

Examples of high-boiling solvents having a boiling point of 115° C. or higher include butanol, dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, butyl carbitol, butyl celuso, methyl celuso, butyl acetate, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol ethyl ether, dipropylene glycol dimethyl ether, 3-methoxymethyl propionate, 3-ethoxy ethyl propionate, propylene glycol Alcohol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate (PGMEA), and one or more of their mixed solvents.

Examples of low-boiling solvents having a boiling point of 100° C. or lower include methyl ethyl ketone, methanol, ethanol, acetone, tetrahydrofuran, isopropanol, and one or more mixed solvents thereof.

The solid content of the resin composition including: a mixed solvent containing a high boiling point solvent having a boiling point of 115° C. or higher and a low boiling point solvent having a boiling point of 100° C. or lower; a binder resin; a photopolymerizable compound containing a phthalate derivative;

Meanwhile, the method or device that can be used in the step of coating and drying the resin composition on the barrier layer is not particularly limited, and for example, the resin composition can be coated on the barrier layer using a conventional coating method, and then dried to prepare a dry film.

The method of coating the resin composition is not particularly limited, and for example, a method such as a coating bar may be used.

In the method for preparing a photosensitive laminate, in addition to using a mixed solvent comprising a high-boiling solvent having a boiling point of 115°C or higher and a low-boiling solvent having a boiling point of 100°C or lower, the volume of fine air bubbles formed in the photosensitive resin layer can be significantly reduced or substantially absent by adjusting the drying rate and/or drying temperature.

More specifically, the step of drying the coated resin composition may be performed by a heating device such as a hot air oven, a hot plate, a hot air circulation boiler, an infrared boiler, and may be dried at a temperature of 50°C to 100°C, or a temperature of 60°C to 90°C, and a temperature of 70°C to 85°C.

The time for drying may vary depending on the drying temperature, and may be, for example, 30 seconds to 20 minutes, more specifically 1 minute to 10 minutes or 3 minutes to 7 minutes.

The content about the binder resin contained in the resin composition includes the content described above in the photosensitive laminate of one embodiment.

The binder resin can have 20,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 300,000 grams/mole, 30,000 grams/mole to 250,000 grams/mole, 30,000 grams/mole to 200,000 grams/mole, or 30,000 grams/mole to 150 grams/mole 1,000 g/mole weight average molecular weight and a glass transition temperature of 20°C to 150°C, 50°C to 150°C, 70°C to 150°C, 70°C to 120°C, 80°C to 120°C, or 100°C to 120°C.

The binder resin may have an acid value of 100 mgKOH/g to 300 mgKOH/g, 120 mgKOH/g to 300 mgKOH/g, 120 mgKOH/g to 250 mgKOH/g, 120 mgKOH/g to 200 mgKOH/g, or 150 mgKOH/g to 200 mgKOH/g.

The resin composition may include a photopolymerizable compound containing phthalate derivatives and an alkaline developable binder resin.

Based on 100 parts by weight of the alkaline developable binder resin, the resin composition may include 1 to 80 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight, 1 to 10 parts by weight, 2 to 50 parts by weight, 2 to 30 parts by weight, 2 to 20 parts by weight, 2 to 10 parts by weight, 3 to 50 parts by weight, 3 to 30 parts by weight, Or 3 parts by weight to 20 parts by weight, or 3 parts by weight to 10 parts by weight of the photopolymerizable compound containing a phthalate derivative.

Concerning the photopolymerizable compound includes what is described above in the photosensitive laminate of one embodiment.

In particular, specific examples of phthalate derivatives may include the compound of Chemical Formula 1. And, more specific examples of the compound of Chemical Formula 1 may include the compound of Chemical Formula 2 or the compound of Chemical Formula 3.

The photopolymerizable compound containing a phthalate derivative may serve as a crosslinking agent for increasing the mechanical strength of the photosensitive resin layer and the like or for increasing resistance to a developer and imparting flexibility to a cured film. Furthermore, depending on the specific chemical structure of the phthalate derivative, it is possible to increase the resistance to plating solution or etching solution and thus it is easier to achieve fine patterns.

More specifically, due to the structure and characteristics of the phthalate derivative, air bubbles having a diameter of 1 micron or less can exist in a trace amount in the photosensitive resin layer, thereby making it possible to provide a photosensitive laminate that can reduce defects in fine wiring formation, can ensure high reliability during development, and thus enables the formation of high-density circuits.

Meanwhile, the photopolymerizable compound may further include a monofunctional (meth)acrylate compound or a multifunctional (meth)acrylate compound.

The content of the monofunctional (meth)acrylate compound or the polyfunctional (meth)acrylate compound can be adjusted according to the specific use or characteristics of the photosensitive resin layer. For example, according to the 100 weights of phthalate derivatives, optical concentrated compounds can include 50 to 1500 weights, 100 weights to 1500 weights, 110 to 1500 weights, 110 to 1,000 weights, 110 weights to 900 weights, 50 to 500 weights. The volume of the single -off -level (methyl) acrylic compound or multi -official (methyl) acrylic compound.

The photoinitiator is a substance that initiates the chain reaction of photopolymerizable monomers by UV and other radiation, and plays an important role in the resin composition and photosensitive resin layer of the photosensitive laminate.

Compounds useful as photoinitiators include anthraquinone derivatives, such as 2-methylanthraquinone and 2-ethylanthraquinone; benzoin derivatives, such as benzoin methyl ether; benzophenone; phenanthrene quinone; and 4,4'-bis(dimethylamino)benzophenone.

In addition, selected from 2,2'-bis(2-chlorophenyl)-4,4'-5,5'-tetraphenylbisimidazole, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-[4-morpholinophenyl]butan-1-one, 2-hydroxy-2 -Methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-[4-(2-hydroxymethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 3,3-dimethyl-4-methoxybenzophenone, benzophenone, 1-chloro-4-propoxythioxanone Xanthone, 1-(4-isopropylphenyl) 2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-benzoyl-4'-methyl dimethyl sulfide, 4-dimethylaminobenzoic acid, 4-dimethylaminobenzoic acid methyl ester, 4-dimethylaminobenzoic acid ethyl ester, 4-dimethylaminobenzoic acid butyl ester 4-dimethylaminobenzoic acid 2-ethyl 2-ylhexyl ester, 2-isoamyl 4-dimethylaminobenzoate, 2,2-diethoxyacetophenone, benzophenone dimethyl acetal, benzophenone β-methoxydiethanol acetal, 1-phenyl-1,2-propyldioxime-o,o'-(2-carbonyl)ethoxyether, methyl phthalate, bis[4-dimethylaminophenyl)ketone, 4,4'-bis(diethylamino)benzophenone, 4,4 '-Dichlorobenzophenone, benzyl, benzoin, methoxybenzoin, ethoxybenzoin, isopropoxybenzoin, n-butoxybenzoin, isobutoxybenzoin, tert-butoxybenzoin, p-dimethylene P-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzosuberone, Compounds of α,α-dichloro-4-phenoxyacetophenone and amyl 4-dimethylaminobenzoate can be used as photoinitiators, but are not limited thereto.

The photoinitiator is contained in an amount of 0.1 wt % to 20 wt % or 1 wt % or more and 10 wt % or less in terms of solid content relative to the total weight of the resin composition. When the content of the photoinitiator is within the above range, sufficient sensitivity can be obtained.

When the content of the photoinitiator is too low, production efficiency may be greatly reduced due to low light efficiency and thus requiring a large amount of light exposure. When the content of the photoinitiator is too high, there are disadvantages that the film becomes brittle and the contamination of the developing solution increases, which may cause defects such as short circuit.

In addition, the resin composition may further contain other additives as needed. Other additives that can be used include phthalinate diaceromes, dysteenate dietteramite, dihaxenate diloder, phenyl -measopate as plasticizer in the form of ethylene glycolitate in the form of ethylene glycol, and ethylene glycol, and ethylene glycol. The toluene sulfurine, phenylsulfine, orthophytic benzenezate amine; trigestyl phosphate; and its analogs.

In order to improve the workability of the resin composition, leuco dyes or coloring substances may also be added. Leuco dyes may include tris(4-dimethylamino-2-methylphenyl)methane, tris(4-dimethylamino-2methylphenyl)methane, fluoran dyes, and the like. In particular, the contrast is favorable and therefore preferred when Leuco Crystal Violet is used. When a leuco dye is contained, the content in the photosensitive resin composition may be 0.1% by weight or more and 10% by weight or less. From the viewpoint of expressing contrast, 0.1% by weight or more is preferable, and from the viewpoint of maintaining storage stability, 10% by weight or less is preferable.

Examples of coloring substances include toluenesulfonic acid monohydrate, magenta, phthalocyanine green, auramine base, paramagenta, crystal violet, methyl orange, Nile blue 2B, victoria blue, malachite green, diamond green ( Diamond green), Basic blue 20, and the like.

When a coloring substance is contained, the photosensitive resin composition may be added in an amount of 0.001% by weight or more and 1% by weight or less. A content of 0.001% by weight or more has an effect of improving handleability, and a content of 1% by weight or less has an effect of maintaining storage stability.

In addition, other additives may further include thermal polymerization inhibitors, dyes, decolorizers, tackifiers and the like.

Meanwhile, according to another embodiment of the present invention, a method for preparing a circuit board using the photosensitive laminate of the embodiment may be provided.

The photosensitive stacks of the embodiments may be used for lamination on copper clad stacks.

As an example of a manufacturing process for a circuit board or printed circuit board (PCB), a pretreatment process is first performed to laminate a copper-clad stack, which is a raw material for the PCB. The pretreatment process is performed in the order of drilling, trimming, scrubbing and the like in the outer layer process. During internal layer processing, scrubbing or dipping is performed. In the scrubbing process, bristle brushes and jet pumice processes are mainly used, and dipping can be performed by soft etching and sulfuric acid dipping.

To form circuits on the pre-processed copper-clad stack, a photosensitive stack or dry film photoresist (hereinafter referred to as DFR) is typically laminated on the copper layer of the copper-clad stack. In this process, the photoresist layer of DFR is laminated on the copper surface, and at the same time, the protective film of DFR is peeled off using a laminator. Generally, it can be laminated at a lamination speed of 0.5 m/min to 3.5 m/min, at a temperature of 100° C. to 130° C., and at a rolling pressure of 10 psi to 90 psi and heated rolling.

The printed circuit board that has undergone the lamination process may be left for 15 minutes or more to stabilize the substrate, and then exposed to the photoresist of the DFR using a photomask on which the desired circuit pattern is formed. When the photomask is irradiated with ultraviolet rays in this process, the photoresist irradiated with ultraviolet rays can initiate polymerization by the photoinitiator contained in the irradiated portion. First, oxygen in the photoresist is consumed in the initial stage, then the monomer is polymerized and activated to cause a crosslinking reaction, and then the polymerization reaction may proceed while consuming a large amount of monomer, and unexposed portions may exist in a state where the crosslinking reaction has not yet proceeded.

Next, a developing process is performed to remove the unexposed portion of the photoresist. In the case of alkaline developable DFR, 0.8% to 1.2% by weight aqueous solutions of potassium carbonate and sodium carbonate can be used as the developing solution. In this method, unexposed portions of the photoresist are washed away by a saponification reaction between the carboxylic acid of the binder polymer and the developer in the developing solution, and the cured photoresist may remain on the copper surface.

Next, circuits can be formed through different processes according to the inner layer and outer layer processes. In the inner layer process, circuits can be formed on the substrate by etching and stripping processes, and in the outer layer process, after electroplating and tenting processes, etching and solder stripping can be performed to form predetermined circuits.

For the exposure, generally known light sources, more specifically, an ultra-high pressure mercury lamp or a laser direct exposure apparatus or the like can be used.

According to the present invention, there can be provided a photosensitive laminate capable of reducing defects in formation of fine wiring, enhancing reliability during development, and enabling formation of high-density circuits; a method of producing the photosensitive laminate; and a method of producing a circuit board.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not intended to be limited thereby. < Preparation Example > Preparation Example 1: Preparation of Alkaline Developable Binder Resin

A mechanical stirrer and reflux device were installed to a four-neck round bottom flask, and then the interior of the flask was purged with nitrogen. 170 grams of methyl ethyl ketone (MEK) and 12.5 grams of methanol (MeOH) were added to the flask purged with nitrogen, and then 2.25 grams of azobisisobutyronitrile (AIBN) were added and completely dissolved. A monomer mixture of 60 g of methacrylic acid (MAA), 100 g of benzyl methacrylate (BzMA), 15 g of methyl methacrylate (MMA), and 75 g of styrene (SM) was added thereto as monomers, and heated to 80° C. and then polymerized for 6 hours to prepare an alkaline developable binder resin (weight average molecular weight: 40,000 g/mol, glass transition temperature: 102° C., solid content: 50% by weight, acid value: 156 mgKOH/g).

The alkaline developable binder resin prepared in Preparation Example 1 was dissolved in tetrahydrofuran so as to have a concentration of 1.0 (w/w)% in THF (about 0.5 (w/w)% in terms of solid content), filtered using a syringe filter having a pore size of 0.45 μm, and then 20 microliters were injected into the GPC. The mobile phase of GPC used tetrahydrofuran (THF) fed at a flow rate of 1.0 ml/min, and the analysis was performed at 40°C. One Agilent PLgel 5 μm Guard (7.5×50 mm) and two Agilent PLgel 5 μm Mixed D (7.5×300 mm) were connected in series. Agilent 1260 Infinity II system, RI detector was used as detector, and measurements were performed at 40°C.

As shown below, polystyrene standard samples (STD A, B, C, D) in which polystyrenes having different molecular weights were dissolved in tetrahydrofuran at a concentration of 0.1 (w/w)% were filtered with a syringe filter having a pore size of 0.45 μm, and then injected into a GPC, and the value of the weight average molecular weight (Mw) of the alkaline developable binder resin was determined using the formed calibration curve. STD A (Mp): 791,000 / 27,810 / 945 STD B (Mp): 282,000 / 10,700 / 580 STD C (Mp): 126,000 / 4,430 / 370 STD D (Mp): 51,200 / 1,920 / 162 Preparation Example 2: Preparation of a composition for forming a barrier layer

A mechanical stirrer and reflux device were installed to a four-neck round bottom flask, and then the interior of the flask was purged with nitrogen. 200 grams of distilled water and 20 grams of butyl cellosolve (BC) were placed in a flask purged with nitrogen and completely dissolved. 20 grams of PVA-205 (KURARAY, polyvinyl alcohol, viscosity: 3.5 centipoise, weight average molecular weight: 22,000 grams/mole) and 1.5 grams of BYK-349 (BYK) were added thereto to prepare a composition for forming a barrier layer. Preparation Example 3: Preparation of a composition for forming a barrier layer

A mechanical stirrer and reflux device were installed to a four-neck round bottom flask, and then the interior of the flask was purged with nitrogen. 200 grams of distilled water and 10 grams of butyl celuso (BC) were placed in a nitrogen-purged flask and completely dissolved. 20 g of PVA-205 (KURARAY, polyvinyl alcohol, viscosity: 3.5 cP, weight average molecular weight: 22,000 g/mol) and 1.5 g of BYK-349 (BYK Chemie) were added thereto to prepare a composition for forming a barrier layer. < Example and Comparative Example : Preparation of Photosensitive Resin Composition and Dry Film Photoresist > Example 1 to Example 3

The composition for forming a barrier layer obtained in Preparation Example 2 was coated on a 25 micron PET film using a coating bar. The coated barrier layer was dried in a hot air oven, wherein the drying temperature was 80° C., and the drying time was 10 minutes. The thickness of the dried barrier layer was 2 μm to 3 μm, the turbidity value of the barrier layer was 1%, and the oxygen permeability was 3.5 cubic centimeters/square meter/day.

Next, according to the composition shown in Table 1 below, the photoinitiator was dissolved in an organic solvent, then a photopolymerizable compound and an alkaline developable binder resin were added, and mixed using a mechanical stirrer for about 1 hour to prepare a photosensitive resin composition.

The obtained photosensitive resin composition was coated on the barrier layer using a coating bar. The coated photosensitive resin composition layer was dried using a hot air oven. At this time, the drying temperature was 80° C., the drying time was 5 minutes, and the thickness of the dried photosensitive resin composition layer was 25 μm.

A protective film (polyethylene) was laminated on the dried photosensitive resin composition layer to prepare a photosensitive laminate (dry film photoresist).

The haze of the barrier layer layer was obtained by peeling off the PET film and measuring using a haze meter (model name: NDH7000, Nippon Denshoku Kogyo Co., Ltd.) according to the ASTM D1003 test method after peeling off the PET film.

The oxygen permeability of the barrier layer was 3.5 cm3/m2/day, and was measured using an OX-Tran (Model 2/61, Mocon, Inc.) instrument according to ASTM F1927 test method. Comparative Example 1

According to the composition described in Example 1 in Table 1 below, a photoinitiator was dissolved in an organic solvent, and then a photopolymerizable compound and an alkaline developable binder resin were added thereto and mixed for about 1 hour using a mechanical stirrer to prepare a photosensitive resin composition.

The obtained photosensitive resin composition was coated on a 25 micron PET film using a coating bar. The coated photosensitive resin composition layer was dried using a hot air oven, wherein the drying temperature was 80° C., the drying time was 5 minutes, and the thickness of the photosensitive resin layer after drying was 25 μm.

A protective film (polyethylene) was laminated on the dried photosensitive resin composition layer to prepare a photosensitive laminate (dry film photoresist). Comparative example 2

A photosensitive laminate (dry film photoresist) was prepared in the same manner as in Example 1 except that the composition for forming a barrier layer obtained in Preparation Example 3 was used instead of the composition for forming a barrier layer obtained in Preparation Example 2.

The haze of the prepared barrier layer was 5%, and the haze of the barrier layer was a value obtained by peeling off the PET film before coating the photosensitive resin composition and measuring according to ASTM D1003 test method using a haze meter (model name: NDH7000, Nippon Denshoku Kogyo Co., Ltd.).

The oxygen permeability of the prepared barrier layer was 4.0 cm 3 /m 2 /day, and was measured using an OX-Tran (Model 2/61, Mocon Corporation, USA) instrument according to ASTM F1927 test method. Comparative example 3

A photosensitive laminate (dry film photoresist) was prepared in the same manner as in the above example except that a photosensitive resin composition was prepared according to the composition shown in Table 1 below. [Table 1] components Product name (or component name) Content (weight%) Example 1 Example 2 Example 3 Comparative example 3 Alkaline developable binder resin Preparation Example 1 55 55 55 55 photopolymerizable compound Phthalate Derivatives 2 3 3 M-2101 14 14 12 14 M-241 3 1 3 3 T063 1 1 A040 1 1 1 3 Photopolymerization initiator BCIM 3.5 3.5 3.5 3.5 9,10-Dibutoxyanthracene 0.5 0.5 0.5 0.5 additive N,N-Diethylbutylamine 0.2 0.2 0.2 0.2 Leuco crystal violet (Hodogaya Co., Japan) 0.5 0.5 0.5 0.5 Diamond Green GH (Japan Hodogaya Chemical Co., Ltd.) 0.3 0.3 0.3 0.3 solvent MEK (methyl ethyl ketone, boiling point: about 80°C) 15 15 15 18 Methanol (about 64.7°C) 2 2 2 2 Propylene glycol monomethyl ether acetate (PGMEA, boiling point: about 146.4°C) 3 3 3 *Phthalate derivatives: (2-[(2-methyl-1-oxoallyl)oxy]ethylhydrogen 3-chloro-2-hydroxypropyl phthalate) (1) M2101: bisphenol A (EO) ₁₀ di(meth)acrylate (Miwon Specialty Chemical) (2) M241: bisphenol A (ethoxylate) ₄ di(meth)acrylate (Miwon Specialty Chemical) ( 3) T063: Trimethylolpropane [EO] ₆ Triacrylate (4) A040: Methoxypropylene glycol [400] acrylate (n=9) (5) BCIM: 2,2'-bis(2-chlorophenyl-4,5,4',5'-tetraphenylbiimidazole, Aldrich Chemical) Comparative Example 4

Except that based on the description of Example 4 of Patent Document 1, with respect to 300 parts by weight of the "alkaline developable binder resin" obtained in Preparation Example 1 of the present invention, the following components were mixed for about 1 hour using a mechanical stirrer to prepare a photosensitive resin composition, and a photosensitive lamination (dry film photoresist) was prepared in the same manner as in the above example. ＜光敏樹脂組成物的組分＞ （1）100重量份的2,2-雙(4-(甲基丙烯醯氧基五乙氧基)苯基)丙烷（2）50重量份的EO、PO改質的胺甲酸酯二(甲基)丙烯酸酯（3）50重量份的聚丙二醇二丙烯酸酯（丙二醇鏈的數目：7） （4）光起始劑：25質量份的苯甲酮、1.0質量份的2-(鄰氯苯基)-4,5-二苯基咪唑二聚體以及1.0質量份的二乙胺基苯并苯乙酮（5）5.0質量份的光致變色劑（6）0.15質量份的染料（7）混合溶劑： 477質量份的丙酮（沸點：56℃）、26.5質量份的甲苯（沸點：110℃）及26.5質量份的丙二醇單甲醚（沸點：146.4℃）[沸點為100℃或低於100℃的低沸點溶劑:沸點為115℃或高於115℃的高沸點溶劑的重量比=19:1] ＜ 實驗實例 ＞

The physical properties of the dry film photoresists prepared in Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below. 1. Measure exposure (unit: mJ / cm2)

The dry film photoresists prepared in the Examples and Comparative Examples were laminated on a 1.6 mm thick copper clad stack subjected to a brush polish treatment. At this time, lamination was performed using HAKUTO MACH 610i at a substrate preheating roll temperature of 120°C, a laminator roll temperature of 115°C, a roll pressure of 4.0 kgf/cm2, and a roll speed of 2.0 min/m.

The PET film of the dry film photoresist laminated on the copper-clad laminate was removed, using an ORC FDi-3, using a 41-step exposure meter from Stouffer Graphic Arts Equipment, and irradiating ultraviolet light at a wavelength of 405 nm for 15 minutes at an exposure amount at which the number of remaining steps was changed to 15 steps. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method. At this time, the amount of energy when the determined number of remaining stages becomes 15 stages is measured.

For Comparative Example 1, on a PET film of a dry film photoresist laminated on a copper-clad laminate, using ORC FDi-3, a 41-step exposure meter from Stouffer Graphic Arts Equipment was used, and ultraviolet light at a wavelength of 405 nm was irradiated for 15 minutes at an exposure amount at which the number of remaining steps was changed to 15 steps. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method. At this time, the amount of energy when the determined number of remaining stages becomes 15 stages is measured. 2. Measurement 1:1 resolution (unit: micron)

The dry film photoresists prepared in the Examples and Comparative Examples were laminated on a 1.6 mm thick copper clad stack subjected to a brush polish treatment. At this time, lamination was performed using HAKUTO MACH 610i at a substrate preheating roll temperature of 120°C, a laminator roll temperature of 115°C, a roll pressure of 4.0 kgf/cm2, and a roll speed of 2.0 min/m.

After removing the laminated PET film and developing it on the barrier layer, by using data formed at intervals of 0.5 μm from 4 μm to 20 μm so that the circuit line width and the pitch interval between the circuit lines can be 1:1, using ORC FDi-3, a 41-level step exposure table of Stouffer Graphic Arts Equipment, irradiated ultraviolet rays with a wavelength of 405 nm for 15 minutes so that the number of remaining steps was 15. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method.

Then, the resolution is determined by using a ZEISS AXIOPHOT microscope by measuring the value with the spacing between the circuit line and the non-circuit line as 1:1.

For Comparative Example 1, using ORC FDi-3 on a PET film of a dry film photoresist laminated on a copper-clad laminate, a 41-step exposure meter from Stouffer Graphic Arts Equipment was used, and ultraviolet light at a wavelength of 405 nm was irradiated for 15 minutes at an exposure amount at which the number of remaining steps was changed to 15 steps. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method. At this time, the amount of energy when the determined number of remaining stages becomes 15 stages is measured. 3. Confirm the air bubbles (unit: number / square millimeter)

For the dry film photoresists prepared in Examples and Comparative Examples, the PET film and the PE film were removed, and then the number (number/square millimeter) of bubbles with a diameter of less than 1 micron existing in the photosensitive resin layer (unit area (1 mm*1 mm)) was confirmed using a polarizing microscope. 4. Confirm substrate defects after exposure / development ( unit : number / square millimeter )

The dry film photoresists prepared in the Examples and Comparative Examples were laminated on a 1.6 mm thick copper clad stack subjected to a brush polish treatment. At this time, lamination was performed using HAKUTO MACH 610i at a substrate preheating roll temperature of 120°C, a laminator roll temperature of 115°C, a roll pressure of 4.0 kgf/cm2, and a roll speed of 2.0 min/m.

After removing the laminated PET film and developing it on the barrier layer, using ORC FDi-3, a 41-level stage exposure meter of Stouffer Graphic Arts Equipment, the number of remaining stages was 15 to irradiate ultraviolet rays with a wavelength of 405 nm, so that the circuit line width and the spacing interval between circuit lines could be 14 μm:14 μm, and kept for 15 minutes. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method.

For each of the dry film photoresists prepared in the development example and the comparative example, the upper surface and the lower surface of the resist were observed in a unit area (1 mm*1 mm) using an electron microscope, and the number (number/square millimeter) of defects of 0.5 μm or more and 3 μm or less was confirmed to exist. The surface and cross section of the photosensitive resin layer obtained in each of Examples and Comparative Examples were observed using a field emission scanning electron microscope (FE-SEM, Hitachi, magnification 3000 times).

For Comparative Example 1, on a PET film of a dry film photoresist laminated on a copper-clad laminate, using ORC FDi-3, a 41-step exposure meter from Stouffer Graphic Arts Equipment was used, and ultraviolet light at a wavelength of 405 nm was irradiated for 15 minutes at an exposure amount at which the number of remaining steps was changed to 15 steps. Thereafter, development was performed with a 1.0% by weight Na ₂ CO ₃ aqueous solution under the development conditions of the spray jet method. At this time, the amount of energy when the determined number of remaining stages becomes 15 stages is measured. [Table 2] category Exposure [mJ/cm2] 1:1 resolution [microns] Bubbles less than 1 micron in diameter [number/mm2] Substrate defects after exposure/development [number/mm²] Example 1 50 5 0 0 Example 2 50 5 0 0 Example 3 50 5 0 0 Comparative Example 1 50 6 1 0 Comparative example 2 50 8 11 7 Comparative example 3 50 11 28 12 Comparative Example 4 350 14 17 7

As confirmed in Table 2 and FIG. 1 , it was confirmed that bubbles with a diameter of less than 1 μm existed in the photosensitive resin layer of the photosensitive laminate of the example at 1 bubble/mm2 or less. Furthermore, it was confirmed that in the photosensitive resin layer of Example, even after exposure to ultraviolet light and development with an alkaline solution, defects having a diameter of 0.5 μm or more and 3 μm or less were substantially not generated or were generated at 1 bubble/mm2 or less.

That is, since air bubbles having a diameter of less than 1 micron exist in a trace amount and a barrier layer having a turbidity of 2% or less is contained in the photosensitive resin layer of the example, it was also observed that when a circuit board is prepared by using a photosensitive lamination, high density and sensitivity can be achieved while high reliability, and finer wiring can be formed.

On the other hand, it was confirmed that in the photosensitive resin laminate of the comparative example, even when the same level of energy as in the example was used, not only was it difficult to achieve the resolution of the example level, but also bubbles with a diameter of less than 1 μm existed in the photosensitive resin layer at 10 bubbles/mm2 or more than 10 bubbles/mm2.

Furthermore, as shown in FIGS. 2 to 4 , it was confirmed that after the photosensitive resin layer obtained in Comparative Example was exposed and developed with an alkaline solution, a large number of defects with a diameter of 0.5 μm or more and 3 μm or less occurred.

none

1 is a photo of the surface and cross section of the photosensitive resin layer of Example 1 confirmed by a field-emission scanning electron microscope (FE-SEM, 800 times) using a polarizing microscope. 2 is a photograph of the surface and cross section of the photosensitive resin layer of Comparative Example 1 confirmed by a field emission scanning electron microscope (FE-SEM, magnification 800) using a polarizing microscope. 3 is a photograph of the surface and cross section of the photosensitive resin layer of Comparative Example 2 confirmed by a field emission scanning electron microscope (FE-SEM, magnification 800) using a polarizing microscope. 4 is a photograph of the surface and cross section of the photosensitive resin layer of Comparative Example 3 confirmed by a field emission scanning electron microscope (FE-SEM, magnification 800) using a polarizing microscope.

Claims (17)

A photosensitive laminate comprising: a barrier layer having a haze of 2% or less; and a photosensitive resin layer including a photopolymerizable compound containing a phthalate derivative, wherein bubbles having a diameter of less than 1 micron exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2, and a binder resin. The photosensitive laminate according to claim 1, wherein: the barrier layer has an oxygen permeability of 10 cm3/m2/day or less than 10 cm3/m2/day. The photosensitive laminate as claimed in claim 1, wherein: the barrier layer comprises a polyvinyl alcohol resin having a weight average molecular weight of 5,000 g/mol to 1,000,000 g/mol. The photosensitive laminate according to claim 3, wherein: the polyvinyl alcohol resin has a viscosity of 1.0 centipoise to 10.0 centipoise. The photosensitive laminate according to claim 1, wherein: the barrier layer has a thickness of 0.1 micron to 10 microns, and the photosensitive resin layer has a thickness of 1 micron to 100 microns. The photosensitive laminate as claimed in claim 1, further comprising a supporting substrate formed on the barrier layer and having a thickness of 1 μm to 100 μm. The photosensitive laminate according to claim 1, further comprising a release layer formed on the photosensitive resin layer and having a thickness of 0.01 μm to 1 meter. The photosensitive laminate as claimed in claim 1, wherein: within 50% of the total thickness of the photosensitive resin layer from the opposite surface of the interface between the barrier layer and the photosensitive resin layer, the bubbles with a diameter of less than 1 micron exist at 3 bubbles/mm2 or less than 3 bubbles/mm2. The photosensitive laminate according to claim 1, wherein: the photosensitive resin layer does not contain air bubbles with a diameter of 1 micron to 5 microns. The photosensitive laminate according to claim 1, wherein after ultraviolet exposure and alkali development, defects with a cross-sectional diameter of 0.3 microns to 4 microns exist in the photosensitive resin layer at or below 3 defects/mm2. The photosensitive laminate according to Claim 1, wherein: the phthalate derivative includes at least one reactive functional group, and the reactive functional group includes a halogen, a hydroxyl group, an ether bond, an ester bond, an amide bond, a vinyl group, a (meth)acrylate group or an aryl group, wherein the ether bond is -O-, the ester bond is -COO- or O-CO-, and the amide bond is -NHCO- or CONH-. The photosensitive laminate as claimed in item 1, wherein: the phthalate derivatives include compounds of the following chemical formula 1:

Wherein, in Chemical Formula 1, R1 and R2 are each independently hydrogen or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, and the aliphatic hydrocarbon group may optionally include a halogen atom, a hydroxyl group, an ether bond, an ester bond, an amide bond, a (meth)acrylate group or an aryl group, wherein the ether bond is -O-, the ester bond is -COO- or O-CO-, and the amide bond is -NHCO- or CONH-. The photosensitive laminate as claimed in item 1, wherein: the phthalate derivatives include the compound of the following chemical formula 2 or the compound of the following chemical formula 3:

The photosensitive laminate as claimed in claim 1, wherein: the photopolymerizable compound further comprises a monofunctional (meth)acrylate compound or a multifunctional (meth)acrylate compound. The photosensitive laminate according to claim 14, wherein: based on 100 parts by weight of the phthalate derivative, the photopolymerizable compound includes 50 to 500 parts by weight of the monofunctional (meth)acrylate compound or the multifunctional (meth)acrylate compound. The photosensitive laminate according to claim 1, wherein: the binder resin has a weight average molecular weight of 20,000 g/mole to 300,000 g/mole and a glass transition temperature of not less than 20°C and not more than 150°C. A method of preparing a circuit board using the photosensitive laminate as claimed in Claim 1.