TW202248240A - 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 an ester-based monomer or oligomer, 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. 10-2021-0042140 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 towards lighter, thinner, shorter and tighter semiconductor devices and multi-level packaging, high-density circuit boards are required, and processes that apply ultra-high pressure mercury lamps or laser direct exposure or use processes including A method for preparing a circuit board by photosensitive lamination of a support film and a photosensitive resin layer and similar processes.

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)

[ technical problem ]

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. [ Technical solution ]

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 The polymer compound contains ester monomers or oligomers, wherein 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.

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 is 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), Filter using a syringe filter with 0.45 micron pore size, and then inject 20 microliters into the GPC. The mobile phase of GPC uses tetrahydrofuran (THF) fed at a flow rate of 1.0 ml/min, and the column is connected in series with one Agilent PLgel 5 μm Guard (7.5×50 mm) and two Agilent PLgel 5 μm Mixed D (7.5× 300mm), Agilent 1260 Infinity Ⅱ system, RI detector was used as detector, and the measurement was carried out at 40°C.

As shown below, polystyrene standards (STD A, B, C, D) in which polystyrene with different molecular weights were dissolved in THF at a concentration of 0.1 (w/w)% were used with 0.45 μm pore size Syringe filter filter and then injected into the GPC, and the value of the weight average molecular weight (Mw) of the alkaline developable binder resin was determined using the calibration curve formed. 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 their chemical structures are completely cured, crosslinked or polymerized , and also includes the case where such components are partially cured, cross-linked or polymerized.

According to another embodiment of the present invention, there may be provided a photosensitive laminate including: a barrier layer having a haze of 2% or less; and a photosensitive resin layer including a photopolymerizable compound and a binder resin, the photosensitive The polymerizable compound contains ester monomers or oligomers, wherein 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.

The present inventors have 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 are separated by 5 Bubbles/mm2 or less than 5 bubbles/mm2 exist, and it has been found through experiments that when this type of photosensitive laminate is used in the preparation process of circuit boards, it is possible to achieve high sensitivity to exposure and increase the reliability during development. characteristics, realize high density and sensitivity while ensuring high reliability, and enable formation of finer wiring, thereby completing the present invention.

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

Specifically, in one embodiment of the photosensitive laminate, the barrier layer may have 2% or less, 0.001% or more and 2% or less or 0.1% or more and 2% or less 2% turbidity.

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

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 Square meters/day, 4 cubic centimeters/square meters/day or less than 4 cubic centimeters/square meters/day, 0.01 cubic centimeters/square meters/day or greater than 0.01 cubic centimeters/square meters/day and 10 cubic meters Centimeter/square meter/day or less than 10 cubic centimeter/square meter/day, 0.01 cubic centimeter/square meter/day or greater than 0.01 cubic centimeter/square meter/day and 5 cubic centimeter/square meter/day or Less than 5 cm3/m2/day or 0.01 cm3/m2/day or greater than 0.01 cm3/m2/day and 4 cm3/m2/day or less than 4 cm3/m2 /day oxygen permeability. The method for measuring 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 Measurement.

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, the barrier layer acts as an oxygen barrier film that blocks the reaction of oxygen free radicals, thus minimizing foreign substances or The formation of air bubbles in the photosensitive resin layer improves the resolution and reliability of the final prepared 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 50,000 g/mol, 7,000 g/mol to 30,000 g/mol, or 10,000 g/mol to 30,000 g/mol 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 high-boiling solvents having a boiling point of 115° C. or higher may include butanol, dimethylformamide, N-methyl-2-pyrrolidone, γ-butyrolactone, butyl carbitol (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, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate (propylene glycol glycol monomethyl ether acetate; PGMEA) and a mixed solvent of one or more thereof.

Specifically, the composition for forming the barrier layer may contain 60 parts by weight or more, 60 parts by weight or more and 200 parts by weight or less than 200 parts by weight based on 100 parts by weight of the polyvinyl alcohol resin. Parts by weight, 70 parts by weight or more than 70 parts by weight and 200 parts by weight or less than 200 parts by weight, 80 parts by weight or more than 80 parts by weight and 200 parts by weight or less than 200 parts by weight, 80 parts by weight or more than 80 parts by weight and 100 parts by weight Parts or less than 100 parts by weight or 90 parts by weight or more than 90 parts by weight and 100 parts by weight or less than 100 parts by weight of high boiling point solvents with 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 point 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 layer may be Satisfies 2% or less, and when the composition for forming the barrier layer contains less than 60 parts by weight of a high boiling point solvent with a boiling point of 115°C or higher based on 100 parts by weight of polyvinyl alcohol resin, it may There is a technical problem that the turbidity of the barrier layer increases sharply.

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 micrometer exist in the photosensitive resin layer at 5 bubbles/mm2 or less than 5 bubbles/mm2 or the bubbles do not exist substantially, therefore In the state where only a barrier layer with a haze of 2% or less is formed, it is still applicable to a semiconductor manufacturing process, thereby making it possible to achieve the same effect as conventionally known photosensitive laminates even at a thinner thickness. Reliability and sensitivity of the same level or higher.

In addition, since the photosensitive laminate of one embodiment is suitable for a semiconductor manufacturing process in a state where a support substrate such as a polyethylene terephthalate (PET) film is peeled off, it is possible to eliminate separate peeling in the semiconductor manufacturing process. Support the substrate. 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 high-boiling-point solvent having a boiling point of 115°C or higher Mixed solvents with low-boiling solvents having a boiling point of 100°C or lower; binder resins, photopolymerizable compounds containing ester monomers or oligomers; Bubbles may exist in the photosensitive resin layer at 5 bubbles/mm2 or less or 3 bubbles/mm2 or less.

In addition, in the preparation method of the photosensitive laminate, in addition to using a mixed solvent containing a high boiling point solvent with a boiling point of 115°C or higher and a low boiling point solvent with a boiling point of 100°C or lower, the The volume of fine air cells in the 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 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 barrier layer and the photosensitive resin layer or toward the outer surface of the photosensitive resin layer, it can enhance reliability during development, This enables the formation of high-density circuits and reduces defects in fine wiring formation, whereby when a photosensitive laminate is used, it can achieve high sensitivity to exposure and improve the production yield of high-density printed circuit boards.

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 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 it is possible to form Finer routing.

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, 3 defects/mm2 or less or 1 defect/mm2 or less than 1 defect/mm2 can be obtained. Defects having a cross-sectional diameter of 0.3 microns to 4 microns or 0.5 microns or more and 3 microns or less are observed in square millimeters, 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 illuminated with light wavelengths in the range of 340 nm to 420 nm, and the remaining stages are measured using a 41-step tablet from Stouffer Graphic Arts Equipment. Exposure can be performed for 1 minute to 60 minutes at the amount of energy when the number of steps becomes 15. 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 was illuminated with light wavelengths ranging from 340 nm to 420 nm, and using a 41-step exposure meter from Stouffer Graphic Arts Equipment, the number of remaining steps measured became 15 steps The amount of energy can be 300 mJ/cm2 or less than 300 mJ/cm2 or 100 mJ/cm2 or less than 100 mJ/cm2, and the resolution after development can be 15 microns or less than 15 Micron, or 10 microns or less than 10 microns, or 7 microns or less than 7 microns, or 5 microns or less than 5 microns.

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

其中，在化學式4中，R ₃為氫或具有1個至10個碳原子的烷基， [化學式5]

其中，在化學式5中，R ₄為氫或具有1個至10個碳原子的烷基，且R ₅為具有1個至10個碳原子的烷基 [化學式6]

其中，在化學式6中，Ar為具有6個至20個碳原子的芳基。 Specific examples of the alkaline 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 The repeating unit represented by and the 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, R ₃ and R ₄ are the same or different from each other and are independently hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ₅ 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, R ₃ and R ₄ 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 1 to 10 carbon atoms Specific examples of alkyl atoms include methyl.

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.

其中，在化學式4-1中，R ₃為氫或具有1個至10個碳原子的烷基。在化學式4-1中，關於R ₃的內容與上文在化學式4中所描述的彼等相同。由化學式4-1表示的單體的特定實例包含丙烯酸（acrylic acid；AA）及甲基丙烯酸（methacrylic acid；MAA）。 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).

其中，在化學式5-1中，R ₄為氫或具有1個至10個碳原子的烷基，且R ₅為具有1個至10個碳原子的烷基。在化學式5-1中，R ₄及R ₅與上文在化學式5中所描述相同。由化學式5-1表示的單體的特定實例包含甲基丙烯酸甲酯（methyl methacrylate；MMA）及丙烯酸丁酯（butyl acrylate；BA）。 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).

其中，在化學式6-1中，Ar為具有6個至20個碳原子的芳基。在化學式6-1中，關於Ar的內容與上文在化學式4中所描述的彼等相同。由化學式6-1表示的單體的特定實例可包含苯乙烯（styrene；SM）。 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 gram/mole or a weight average molecular weight of 30,000 gram/mole to 150,000 gram/mole.

In addition, the binder resin should have at least a certain level of heat resistance, and thus may have a temperature of 20°C or more and 150°C or less, 50°C or more and 150°C or less, 70°C or more and 150°C or less, 70°C or more and 120°C or less and a glass transition temperature of 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 in consideration of the developability of the photosensitive resin layer. g or less, 120 mgKOH/g or more and 200 mgKOH/g or less, or 150 mgKOH/g or more and 200 mgKOH/g or less.

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 Weight average molecular weight of up to 250,000 g/mole, 30,000 g/mole to 200,000 g/mole, or 30,000 g/mole to 150,000 g/mole and a weight average molecular weight of 20°C to 150°C, 50°C to 150°C , a glass transition temperature of 70°C to 150°C, 70°C to 120°C, 80°C to 120°C, or 100°C to 120°C. These may respectively have different weight average molecular weights, glass transition temperatures or acid numbers.

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 than 1:3, 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 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 more than 1:1.01 and 1:1.5 or less than 1:1.5, 1:1.1 or more 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 ester monomers or oligomers.

Photopolymerizable compounds containing ester monomers or oligomers can serve as crosslinks for increasing the mechanical strength of the photosensitive resin layer and the like or can be used to increase resistance to developers and impart flexibility to cured films agent.

In addition, by using photopolymerizable compounds containing ester monomers or oligomers, the photosensitive resin layer can have higher adhesion to the barrier layer, and can greatly shorten the developing time or stripping time of the photosensitive laminate.

Specific examples of ester monomers or oligomers include (meth)acrylates to which one or more hydroxyl, epoxy, or amine groups are bonded.

The (meth)acrylate to which one or more hydroxyl, epoxy or amine groups are bonded has a structure in which the (meth)acrylate functional group is located at either end, any of the hydroxyl, epoxy or amine groups One or more may be located at one or more other termini, and the divalent organic functional groups may serve as mediator linkages between (meth)acrylate functional groups and hydroxyl, epoxy or amine functional groups.

In addition, more specific examples of the ester monomer or oligomer may include the compound of Chemical Formula 1 below. [Chemical Formula 1] CH ₂ =CR ¹ -COO-R ² -OH wherein, in Chemical Formula 1, R ¹ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ² is an alkyl group having 1 to 100 carbon atoms A divalent saturated aliphatic hydrocarbon group with carbon atoms, wherein the saturated aliphatic hydrocarbon group may optionally include a halogen atom, an ether bond (-O-), an ester bond (-COO- or O-CO-), an amide bond (-NHCO- or CONH-) or aryl.

More specifically, ester monomers or oligomers may include glycerol mono(meth)acrylate, 2-hydroxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, poly Ethylene glycol monoacrylate, Hydroxypropyl (meth)acrylate, Polypropylene glycol mono(meth)acrylate, Polypropylene glycol monoacrylate, Poly(ethylene glycol propylene glycol)-mono(meth)acrylate, Polyethylene glycol Diol polypropylene glycol-mono(meth)acrylate, poly(ethylene glycol butylene glycol)-mono(meth)acrylate (product name: Blemmer 55 PET-800, etc.), poly(propylene glycol butylene glycol) )-mono(meth)acrylate, propylene glycol polytetramethylene glycol-mono(meth)acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 1,4-cyclo Hexane dimethanol monoacrylate, or a mixture of two or more.

The weight-average molecular weight of the ester monomer or oligomer is not particularly limited, but for example, it may have 50 g/mole to 10,000 g/mole, or 70 g/mole to 5,000 g/mole, Or a weight average molecular weight of 80 g/mol to 1,200 g/mol, or 100 g/mol to 1,000 g/mol.

The content of the photopolymerizable compound containing ester monomer or oligomer can be adjusted according to the use 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 may be contained. 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 parts by weight to 30 parts by weight, 5 parts by weight to 20 parts by weight, and 5 parts by weight to 10 parts by weight of photopolymerizable compounds containing ester monomers or oligomers.

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 containing ester monomer or oligomer Depending on the selection of the photopolymerizable compound of the material, fine 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 photopolymerizable compounds containing ester monomers or oligomers, air bubbles with a diameter of 1 micrometer or less may exist in a trace amount in the photosensitive resin layer, whereby it is possible Provided is a photosensitive laminate that can reduce defects in the formation of fine wiring, 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. As the photopolymerizable compound, generally known monofunctional or polyfunctional (meth)acrylate monomers or oligomers can be used.

Examples of photopolymerizable compounds that can be additionally used are not particularly limited, but include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, propylene glycol dimethyl Acrylates, Polyethylene Glycol Dimethacrylate, Polypropylene Glycol Dimethacrylate, Butylene Glycol Dimethacrylate, Neopentyl Glycol Dimethacrylate, 1,6-Hexanediol Dimethacrylate Acrylates, Trimethylolpropane Trimethacrylate, Trimethylolpropane Triacrylate, Glycerol Dimethacrylate, Neopentylthritol Dimethacrylate, Neopentylthritol Trimethacrylate esters, dipentylthritol pentamethacrylate, 2,2-bis(4-methacryloxydiethoxyphenyl)propane, 2,2-bis(4-methacryloxypolyethylene oxyphenyl) propane, 2-hydroxy-3-methacryloxypropyl methacrylate, ethylene glycol diglycidyl ether dimethacrylate, diethylene glycol diglycidyl ether dimethacrylate esters, diglycidyl phthalate dimethacrylate, glycerol polyglycidyl ether polymethacrylate, 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, based on 100 parts by weight of the ester monomer or oligomer, the photopolymerizable compound may contain 50 parts by weight to 1500 parts by weight, 100 parts by weight to 1500 parts by weight, 110 parts by weight to 1500 parts by weight, 110 to 1000 parts by weight, 110 to 900 parts by weight, 50 to 500 parts by weight of monofunctional (meth)acrylate compound or polyfunctional (meth)acrylate 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 fiber Triacetyl cellulose (TAC) film, polynorbornene (polynorbornene; PNB) film, cycloolefin polymer (cycloolefin polymer; COP) film and polycarbonate (polycarbonate; 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 Do not release from the mold 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 (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, a method for preparing a photosensitive laminate may be provided, the method comprising the following steps: coating and drying a resin composition on the barrier layer, the resin composition comprising: Mixed solvents of high-boiling-point solvents above 115°C and low-boiling-point solvents having a boiling point of 100°C or below; binder resins; photopolymerizable compounds containing ester monomers or oligomers; and photoinitiators .

Depending on the method of preparation, the photosensitive laminate described above in one embodiment can 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 an ester monomer and a binder resin. Or an oligomer in which bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer at or below 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 of preparing a photosensitive laminate, since 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 is used, it is possible to delay the formation of the photosensitive resin composition. The evaporation time of the solution and prevent air bubbles from being trapped in the resin layer, thus air bubbles with a diameter of less than 1 micron exist in the photosensitive resin layer with 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 with a diameter of less than 1 μm may be 3 bubbles/mm2 or less than 3 bubbles/square mm exists.

Since air bubbles having a diameter of less than 1 micron may exist in a trace amount 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, such that High-density circuits can be formed and defects in fine wiring formation can be reduced, whereby when a photosensitive laminate is used, high sensitivity to exposure can be realized, and the 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, with respect to 100 parts by weight of the mixed solvent, the content of the high boiling point solvent with a boiling point of 115° C. or higher may be 3 parts by weight or more, or 5 parts by weight or more, or 3 parts by weight to 50 parts by weight, or 5 parts by weight 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 having a boiling point of 115°C or higher in a weight ratio of 1:2 to 1:20 or 1:3 to 1:15:boiling point of 100°C or lower low boiling point solvents. 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 Cellusu, Methyl Cellusu, Butyl Acetate, Diethylene Glycol Methyl Ether, Diethylene Glycol Dimethyl Ether, Diethylene Glycol Ethyl Ether, Dipropylene Glycol Dimethyl Ether, Methyl 3-Methoxypropionate , 3-ethoxy ethyl propionate, propylene glycol 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.

In consideration of a specific purpose or field of application, the solid content of the resin composition 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 can be adjusted. A mixed solvent of a boiling point solvent; a binder resin; a photopolymerizable compound containing an ester monomer or oligomer; and a photoinitiator, and for example, the resin composition may contain 10% by weight to 99% by weight of solvent.

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 of producing a 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, formed in the photosensitive resin layer The volume of fine air bubbles 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 heating means such as a hot air oven, a hot plate, a hot air circulation boiler, an infrared boiler, and may be performed at a temperature of 50°C to 100°C or at a temperature of 60°C Drying is carried out at a temperature of to 90°C and at 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 Mole or weight average molecular weight of 30,000 g/mole to 150,000 g/mole and 20°C to 150°C, 50°C to 150°C, 70°C to 150°C, 70°C to 120°C and a glass transition temperature of 80°C to 120°C or 100°C to 120°C.

The binder resin may have 100 mgKOH/g or more and 300 mgKOH/g or less, 120 mgKOH/g or more and 300 mgKOH/g or less, 120 mgKOH/g or more and 250 mgKOH/g or less, 120 mgKOH/g or more and 200 mgKOH/g or less. An acid value of not more than g or not less than 150 mgKOH/g and not more than 200 mgKOH/g.

The resin composition may include photopolymerizable compounds containing ester monomers or oligomers and an alkaline developable binder resin.

Based on 100 parts by weight of the alkaline developable binder resin, the resin composition may contain 1 to 80 parts by weight, 1 to 50 parts by weight, 1 to 30 parts by weight, 1 to 20 parts by weight Parts, 1 parts by weight to 10 parts by weight, 2 parts by weight to 50 parts by weight, 2 parts by weight to 30 parts by weight, 2 parts by weight to 20 parts by weight, 2 parts by weight to 10 parts by weight, 5 parts by weight to 50 parts by weight, 5 to 30 parts by weight, 5 to 20 parts by weight, and 5 to 10 parts by weight of photopolymerizable compounds containing ester monomers or oligomers.

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

In the production method of the photosensitive laminate of the example, two or more solvents having different boiling points are mixed and used, and depending on the selection of the photopolymerizable compound to be used, it is possible to form fine air bubbles in a trace amount The presence or absence of a photosensitive resin layer.

Specifically, a specific example of the ester monomer or oligomer may include the compound of Chemical Formula 1.

A photopolymerizable compound containing an ester monomer or oligomer may serve as a crosslink for increasing the mechanical strength of the photosensitive resin layer and the like or to increase resistance to a developer and impart flexibility to a cured film agent. In addition, by using photopolymerizable compounds containing ester monomers or oligomers, the photosensitive resin layer can have higher adhesion to the barrier layer, and can greatly shorten the developing time or stripping time of the photosensitive laminate.

Due to the structure and characteristics of the ester monomer or oligomer, air bubbles with a diameter of 1 micrometer or less can exist in a trace amount in the photosensitive resin layer, thereby making it possible to provide It is possible to ensure high reliability during development and thus enable formation of a photosensitive laminate 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, based on 100 parts by weight of the ester monomer or oligomer, the photopolymerizable compound may contain 50 parts by weight to 1500 parts by weight, 100 parts by weight to 1500 parts by weight, 110 parts by weight to 1500 parts by weight, 110 to 1000 parts by weight, 110 to 900 parts by weight, 50 to 500 parts by weight of monofunctional (meth)acrylate compound or polyfunctional (meth)acrylate 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 that can be used 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 Base-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-di Ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 3,3-dimethyl-4-methoxydiphenylketone, benzophenone, 1 -Chloro-4-propoxythioxanthone, 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, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 2-ethylhexyl dimethylaminobenzoate, 4-dimethylaminobenzene 2-Isoamyl formate, 2,2-diethoxyacetophenone, Benzyl ketone dimethyl acetal, Benzyl ketone β-methoxydiethanol acetal, 1-phenyl-1, 2-Propyldioxime-o,o'-(2-carbonyl)ethoxyether, methyl phthalylbenzoate, bis[4-dimethylaminophenyl)ketone, 4,4'- Bis(diethylamino)benzophenone, 4,4'-dichlorobenzophenone, benzyl, benzoin, methoxybenzoin, ethoxybenzoin, isopropoxybenzoin (isopropoxybenzoin), n-butoxybenzoin, isobutoxybenzoin, tert-butoxybenzoin, p-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone , 2-isopropylthioxanthone, dibenzosuberone, α,α-dichloro-4-phenoxyacetophenone and 4-dimethylaminobenzoic acid amyl ester can be Used as a photoinitiator, but 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 necessary. Other additives that can be used include dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, diallyl phthalate in the form of phthalates as plasticizers agents; triethylene glycol diacetate, tetraethylene glycol diacetate in the form of ethylene glycol esters; p-toluenesulfonamide, benzenesulfonamide, n-butylbenzenesulfonamide in the form of amides ; triphenyl phosphate; and analogs thereof.

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, basic blue 20 and their analogs.

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 carried out 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 a 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, the oxygen in the photoresist is consumed in the initial stage, then the monomer is activated by polymerization to cause a crosslinking reaction, and then the polymerization reaction can proceed while consuming a large amount of monomer, and the unexposed part can be where the crosslinking reaction has not progressed status exists.

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 saponification between the carboxylic acid of the binder polymer and the developing solution within 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. [ favorable effect ]

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 fitted 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 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/mole, 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), using a A 0.45 micron pore size syringe filter was filtered and 20 microliters were then 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 standards (STD A, B, C, D) in which polystyrene with different molecular weights were dissolved in THF at a concentration of 0.1 (w/w)% were used with 0.45 μm pore size Syringe filter filter and then injected into the GPC, and the value of the weight average molecular weight (Mw) of the alkaline developable binder resin was determined using the calibration curve formed. 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 fitted 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 g of PVA-205 (KURARAY, polyvinyl alcohol, viscosity: 3.5 centipoise, weight average molecular weight: 22,000 g/mol) and 1.5 g of BYK-349 (BYK) were added thereto to prepare a Composition. Preparation Example 3: Preparation of a composition for forming a barrier layer

A mechanical stirrer and reflux device were fitted 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 the A composition that forms 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. Dry the coated barrier layer in a hot air oven, wherein the drying temperature is 80° C., and the drying time is 10 minutes. The thickness of the barrier layer after drying is 2 microns to 3 microns, and the turbidity value of the barrier layer is 1%, and transparent Oxygen is 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 A photosensitive resin composition is prepared.

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, the photoinitiator was dissolved in an organic solvent, and then a photopolymerizable compound and an alkaline developable binder resin were added thereto and mixed using a mechanical stirrer About 1 hour to prepare the 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

Except using the composition for forming the barrier layer obtained in Preparation Example 3 to replace the composition for forming the barrier layer obtained in Preparation Example 2, a photosensitive laminate (dry film photoresist) was prepared in the same manner as in Example 1. agent).

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

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

（4）A040：甲氧基丙二醇[400]丙烯酸酯

 （n=9） （5）BCIM：2,2'-雙(2-氯苯基-4,5,4',5'-四苯基雙咪唑，奧德里奇化學（Aldrich Chemical） 比較實例 4 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 Blemmer 55 PET-800 2 3 3 M-2101 12 11 13 14 M-241 3 3 3 3 T063 2 2 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 *Blemmer 55 PET-800: Poly(ethylene glycol butylene glycol)-mono(meth)acrylate (1) M2101: Bisphenol A(EO) ₁₀ dimethacrylate (Miwon Specialty Chemical)) (2) M241: Bisphenol A (Ethoxylate) ₄ Di(meth)acrylate (Meiyuan Special Chemicals) (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

In addition to the description based on Example 4 of Patent Document 1, regarding 300 parts by weight of the "alkaline developable binder resin" obtained in Production Example 1 of the present invention, the following components were mixed for about 1 hour using a mechanical stirrer to prepare Except for the photosensitive resin composition, a photosensitive laminate (dry film photoresist) was prepared in the same manner as in the above example. <Components of photosensitive resin composition> (1) 100 parts by weight of 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane (2) 50 parts by weight of EO, PO Modified urethane di(meth)acrylate (3) 50 parts by weight of polypropylene glycol diacrylate (number of propylene glycol chains: 7) (4) Photoinitiator: 25 parts by weight of benzophenone, 1.0 parts by mass of 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer and 1.0 parts by mass of diethylaminobenzophenone (5) 5.0 parts by mass of photochromic agent ( 6) 0.15 parts by mass of dye (7) Mixed solvent: 477 parts by mass of acetone (boiling point: 56°C), 26.5 parts by mass of toluene (boiling point: 110°C) and 26.5 parts by mass of propylene glycol monomethyl ether (boiling point: 146.4°C ) [The weight ratio of low boiling point solvent with a boiling point of 100°C or lower: high boiling point solvent with a boiling point of 115°C or higher = 19:1] < Experimental example >

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 ORC FDi-3, using a 41-stage exposure meter from Stouffer Graphic Arts Equipment, and the number of steps remaining changed to The exposure level at level 15 is to irradiate ultraviolet rays with a wavelength of 405 nm 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. At this time, the amount of energy when the determined number of remaining stages becomes 15 stages is measured.

For Comparative Example 1, ORC FDi-3 was used on a PET film of dry film photoresist laminated on a copper-clad laminate, using a 41-stage exposure sheet from Stouffer Graphic Arts Equipment, and in the remaining stages The exposure dose when the number of steps changes to 15 is to irradiate ultraviolet light with a wavelength of 405 nm and keep it 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. 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, the circuit line width and the pitch interval between the circuit lines can be 1:1, using ORC FDi-3, Stouffer Graphic Arts Equipment's 41-level stage exposure meter, so that the number of remaining stages is 15, irradiate ultraviolet light with a wavelength of 405 nanometers, and keep it 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.

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, ORC FDi-3 was used on a PET film of dry film photoresist laminated on a copper-clad laminate, using a 41-stage exposure sheet from Stouffer Graphic Arts Equipment, and using the remaining stages of The exposure dose when the number of steps changes to 15 is to irradiate ultraviolet rays with a wavelength of 405 nm 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. 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 it was confirmed using a polarizing microscope that the diameter of the photosensitive resin layer (unit area (1mm*1mm)) was less than 1 micron The number of bubbles (number/mm²). 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, an ORC FDi-3, 41-level step exposure meter from Stouffer Graphic Arts Equipment was used to irradiate the wavelength with an exposure amount such that the number of remaining level steps was 15 The ultraviolet rays of 405 nanometers make the width of the circuit lines and the spacing between the circuit lines 14 microns: 14 microns, and keep 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 developing 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 presence of 0.5 The number of defects (number/square millimeter) of microns or more than 0.5 microns and 3 microns or less. 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, ORC FDi-3 was used on a PET film of dry film photoresist laminated on a copper-clad laminate, using a 41-stage exposure sheet from Stouffer Graphic Arts Equipment, and in the remaining stages The exposure dose when the number of steps changes to 15 is to irradiate ultraviolet light with a wavelength of 405 nm and keep it 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. 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 1 0 Example 2 50 5 0 0 Example 3 50 5 0 0 Comparative Example 1 50 7 1 0 Comparative example 2 50 8 12 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.

That is, since 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 was prepared by using a photosensitive laminate When, high density and sensitivity can be realized with 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 bubbles with a diameter of Or more than 10 bubbles/mm2 exist in the photosensitive resin layer.

Furthermore, as shown in FIGS. 2 to 4, it was confirmed that after the photosensitive resin layer obtained in the comparative example was exposed to light 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 The photosensitive resin layer includes a photopolymerizable compound and a binder resin, the photopolymerizable compound contains ester monomers or oligomers, The 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 photosensitive laminate as claimed in claim 1, wherein: The barrier layer has an oxygen permeability of 10 cm3/m2/day or less. The photosensitive laminate as claimed in claim 1, wherein: The barrier layer includes a polyvinyl alcohol resin having a weight average molecular weight of 5,000 g/mol to 1,000,000 g/mol. The photosensitive laminate as claimed in claim 3, wherein: The polyvinyl alcohol resin has a viscosity of 1.0 centipoise to 10.0 centipoise. The photosensitive laminate as claimed in claim 1, wherein: the barrier layer has a thickness of 0.1 microns to 10 microns, and The photosensitive resin layer has a thickness of 1 micron to 100 microns. A photosensitive laminate as claimed in claim 1, The photosensitive stack further includes a supporting substrate formed on the barrier layer and having a thickness of 1 μm to 100 μm. A photosensitive laminate as claimed in claim 1, The photosensitive laminate further includes a release layer formed on the photosensitive resin layer and having a thickness of 0.01 micron 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 number of bubbles with a diameter of less than 1 μm is 3 bubbles/mm2 or less than 3 bubbles/mm² exist. The photosensitive laminate as claimed in claim 1, wherein: The photosensitive resin layer does not contain air bubbles with a diameter of 1 micron to 5 microns. The photosensitive laminate as claimed in claim 1, wherein: Defects having a cross-sectional diameter of 0.3 μm to 4 μm after ultraviolet exposure and alkali development exist in the photosensitive resin layer at or below 3 defects/mm2. The photosensitive laminate as claimed in claim 1, wherein: The ester monomer or oligomer includes (meth)acrylate bonded by one or more hydroxyl groups, epoxy groups or amine groups. The photosensitive laminate as claimed in item 1, wherein: the ester monomer or oligomer includes a compound of the following chemical formula 1: [chemical formula 1] CH ₂ =CR ¹ -COO-R ² -OH wherein, in the chemical formula 1, R ¹ is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R ² is a divalent saturated aliphatic hydrocarbon group having 1 to 100 carbon atoms, wherein the saturated aliphatic hydrocarbon group may optionally include Halogen atom, ether bond (-O-), ester bond (-COO- or O-CO-), amide bond (-NHCO- or CONH-) or aryl group. The photosensitive laminate as claimed in claim 1, wherein: The ester monomers or oligomers include glycerol mono(meth)acrylate, 2-hydroxyethyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polyethylene glycol mono Acrylates, Hydroxypropyl (meth)acrylate, Polypropylene glycol mono(meth)acrylate, Polypropylene glycol monoacrylate, Poly(ethylene glycol propylene glycol)-mono(meth)acrylate, Polyethylene glycol polypropylene glycol - Mono(meth)acrylate, Poly(ethylene glycol butylene glycol)-mono(meth)acrylate, Poly(propylene glycol butylene glycol)-mono(meth)acrylate, Propylene glycol polytetramethylene glycol - Mono(meth)acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, or both or more a mixture of those. The photosensitive laminate as claimed in claim 1, wherein: The photopolymerizable compound further includes a monofunctional (meth)acrylate compound or a multifunctional (meth)acrylate compound. A photosensitive laminate as claimed in claim 14, wherein: Based on 100 parts by weight of the ester monomer or oligomer, the photopolymerizable compound includes 50 to 500 parts by weight of the monofunctional (meth)acrylate compound or the polyfunctional (meth)acrylate compound. base) acrylate compounds. The photosensitive laminate as claimed in claim 1, wherein: The binder resin has a weight average molecular weight of 20,000 g/mol to 300,000 g/mol 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.

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