TWI780533B - Photosensitive laminate, preparation method of photosensitive laminate, and preparation method of circuit board - Google Patents

Abstract

The present disclosure relates to a photosensitive laminate, a preparation method of the photosensitive laminate, and a preparation method of a circuit board. The photosensitive laminate includes a supporting substrate; and a photosensitive resin layer formed on the supporting substrate, wherein 5 bubbles/mm² or less having a diameter of less than 1 μm are present in the photosensitive resin layer.

Description

Photosensitive laminate, method for preparing photosensitive laminate, and circuit board Preparation

The present disclosure relates to a photosensitive laminate, a method for preparing the photosensitive laminate and a method for preparing a circuit board.

[CROSS-REFERENCE TO RELATED APPLICATIONS]

This application claims Korean Patent Application No. 10-2019-0179860 filed on December 31, 2019 and Korean Patent Application No. 10 filed on August 7, 2020 with the Korean Intellectual Property Office. - Benefits of Korean Patent Application No. 2020-0099130 and Korean Patent Application No. 10-2020-0125243 filed on September 25, 2020, the disclosure of which is incorporated herein by reference in its entirety.

The photosensitive resin composition is used in the form of dry film photoresist (DFR), liquid photoresist ink, etc., which are used in printed circuit boards (PCB) or lead frames.

In recent years, according to the manufacturing trend of light, thin, short and small or multi-level packaging of semiconductor devices, high density is required for circuit boards, and applications such as ultra-high pressure mercury lamps Or the process of direct laser exposure or the widely used circuit board preparation process using a photosensitive laminate including a support film and a photosensitive resin layer.

Therefore, there is a continuous need to develop methods and processes for realizing high density and sensitivity while ensuring higher reliability, and for forming finer wiring.

In the present disclosure, there is provided a photosensitive laminate capable of forming high-density circuits by ensuring high reliability during development while reducing defects in fine wiring formation.

In the present disclosure, a method for preparing the above-mentioned photosensitive laminate is also provided.

In the present disclosure, a method for preparing a circuit board is also provided, which uses the above-mentioned photosensitive laminate.

In the present disclosure, there is provided a photosensitive laminate comprising a support substrate; and a photosensitive resin layer formed on the support substrate, wherein 5 bubbles/mm2 or less with a diameter of less than 1 micron exist in the photosensitive resin layer 5 bubbles/mm².

In the present disclosure, a method for preparing a circuit board is also provided, which uses the above-mentioned photosensitive laminate.

In the present disclosure, a method for preparing the above-mentioned photosensitive laminate is also provided.

Figure 1 is a field emission scanning electron microscope by using a polarizing microscope (FE-SEM, 3000 times) Confirmed photos of the surface and cross-section of the photosensitive resin layer of Example 1.

2 is a photo 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, 3000 times) using a polarizing microscope.

3 is a photograph for confirming defects formed on the photosensitive resin layer of Comparative Example 1 after exposure to ultraviolet rays and development with alkali by field emission scanning electron microscope (FE-SEM, 3000 times).

4 is a photograph for confirming defects formed on the photosensitive resin layer of Comparative Example 1 after exposure to ultraviolet rays and development with alkali by field emission scanning electron microscope (FE-SEM, 3000 times).

5 is a photograph for confirming defects formed on the photosensitive resin layer of Comparative Example 3 after being exposed to ultraviolet rays and developed with alkali by field emission scanning electron microscope (FE-SEM, 3000 times).

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

In the present disclosure, the weight average molecular weight means the weight average molecular weight converted from polystyrene measured by GPC. In the process of measuring the weight average molecular weight converted with polystyrene measured by GPC, generally known analytical devices, detectors such as refractive index detectors, and columns for analysis can be used, And generally applied temperature conditions, solvents, and flow rates can be applied.

As a specific example of measurement conditions, an alkaline developable binder resin was A concentration of 1.0 (w/w)% (approximately 0.5 (w/w)% based on solids content) in THF was dissolved in tetrahydrofuran and then filtered using a 0.45 micron pore size syringe filter before injecting 20 microliters into the GPC middle. The mobile phase of GPC was tetrahydrofuran (THF) and flowed at a flow rate of 1.0 mL/min. Use one of the Agilent PLgel 5 micron Guard (7.5 × 50 mm) and two Agilent PLgel 5 micron Mixed D (7.5 × 300 mm) connected in series, and Agilent 1260 Infinity II system, RI detector for 40 ℃ down to measure.

Polystyrene standard samples (STD A, STD B, STD C, STD D) obtained by dissolving polystyrene with various molecular weights in tetrahydrofuran at a concentration of 0.1 (w/w)% were passed through a 0.45 μm-bore needle Cartridge filter filtration and then injection into the GPC to obtain the weight average molecular weight (Mw) of the basic developable binder resin using a calibration curve formed therefrom.

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

The term "(photo)cured product" or "(photo)cured" includes not only the case where a component having a curable or crosslinkable unsaturated group in the chemical structure is completely cured, crosslinked or polymerized, but also includes such a component Partially cured, cross-linked or polymerized.

According to an embodiment of the present disclosure, there is provided a photosensitive laminate comprising a support substrate; and a photosensitive resin layer formed on the support substrate, wherein 5 bubbles/mm2 having a diameter of less than 1 micron exist in the photosensitive resin layer or Less than 5 bubbles/mm2.

The present inventors have newly developed a photosensitive laminate comprising a photosensitive resin layer in which 5 bubbles/mm2 or less than 5 bubbles/mm2 having a diameter of less than 1 micrometer, or 0.001 micrometer or more and less than 1 micrometer exists. It has been experimentally confirmed that the use of such a photosensitive laminate enables high sensitivity to light exposure in the process of preparing circuit boards, and improves reliability during development, thereby ensuring high reliability, achieving high density and sensitivity, and enabling Form finer wiring.

The present inventors have continuously conducted research and development to remove traces of microbubbles or fine by-products that may occur due to various reasons during the preparation process, and to use together a solvent containing a mixed solvent (including a high temperature solvent having a boiling point of 115° C. or higher than 115° C. boiling point solvents and low boiling point solvents with a boiling point of 100°C or lower), a basic developable binder resin containing a carboxyl group, and a photoinitiator such that particles with a diameter of less than 1 micron exist in the photosensitive resin layer 5 bubbles/mm2 or less than 5 bubbles/mm2, or 3 bubbles/mm2 or less than 3 bubbles/mm2.

In addition, in the photosensitive laminate production method, in addition to using 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, by adjusting the drying The rate and/or drying temperature can greatly reduce or can be substantially absent from the amount of microbubbles formed in the photosensitive resin layer.

At the same time, in the photosensitive resin layer, there may be 5 bubbles/mm2 or less than 5 bubbles/mm2, or 3 bubbles/mm2 or less than 3 bubbles/mm2, wherein the diameter of the bubbles is less than 1 micron . Specifically, bubbles having a diameter of less than 1 micron may exist in a trace amount or may not exist substantially on the opposite surface of the interface between the support substrate and the photosensitive resin layer or on the outer surface of the photosensitive resin layer. More specifically, 3 bubbles/mm2 having a diameter of less than 1 micrometer may exist within 50% of the total thickness of the photosensitive resin layer on the opposite surface from the interface between the support substrate and the photosensitive resin layer. m or less than 3 bubbles/mm2.

Since air bubbles having a diameter of less than 1 micrometer exist in a trace amount or substantially do not exist on the opposite surface of the interface between the support substrate and the photosensitive resin layer or on the outer surface of the photosensitive resin layer, reliability is improved during development, thereby making it possible to High-density circuits are formed and defects in fine wiring formation can be reduced. Therefore, when the photosensitive laminate is used, high sensitivity to light exposure can be realized, and the production yield of high-density printed circuit boards can be improved.

Furthermore, in the photosensitive laminate, not only bubbles having a diameter of less than 1 micrometer may exist in a trace amount or may not exist substantially, but also bubbles having a diameter of 1 micrometer or more and 5 micrometers or less may not exist.

In this way, when a photosensitive laminate in which a small number of air bubbles less than 1 micron in diameter exist in the photosensitive resin layer is used in the production of a circuit board, high density and sensitivity can be achieved while ensuring high reliability, and it is possible to form finer the wiring.

More specifically, even when the photosensitive resin layer is exposed to ultraviolet rays and developed with an alkaline solution, defects may not appear or may appear in an extremely small amount in the entire area. Specifically, there are substantially no defects on the upper surface of the photosensitive resin layer, and microscopic defects may exist on the lower surface or inside of the photosensitive resin layer after development.

Specifically, after exposing the photosensitive resin layer to ultraviolet rays, followed by development with an alkaline solution, 3 defects/mm2 or less, or 1 defect/mm2 or less are observed 1 defect/mm2, or there may be substantially no defects, wherein the defect has a cross-sectional diameter of 0.3 micrometers to 4 micrometers, or 0.5 micrometers or more and 3 micrometers or less. The cross-sectional diameter of a defect may be defined as a maximum diameter among diameters of defects 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 exposure can be performed with an amount of energy such that the remaining number of steps is 15 for 1 minute to 60 minutes using a 41-step plate made by Stouffer Graphic Arts Equipment at 340 nm The light striking the photosensitive laminate is measured in the range of 420nm. In addition, development may be performed by a method such as a spray coating method with an alkaline aqueous solution such as Na ₂ CO ₃ at a concentration of 0.1% by weight to 3.0% by weight.

In addition, when photosensitive laminates are used, it is possible to achieve higher density and sensitivity while using less energy. More specifically, the amount of energy such that the remaining number of steps is 15 steps may be 300 mJ/cm2 or less, or 100 mJ/cm2 or less, wherein Light impinging on the photosensitive laminate was measured in the range of 340nm to 420nm using a 41-step flat panel manufactured by Stover Graphics Equipment. In addition, the resolution after development may be 15 microns or less, or 10 microns or less.

The thickness of the support substrate and the thickness of the photosensitive resin layer in the photosensitive laminate are not particularly limited, but the thickness of the support substrate may be 1 μm to 100 μm, or 5 μm to 50 μm, and the thickness of the photosensitive resin layer may be 1 μm to 100 μm. Microns to 100 microns, or 5 microns to 50 microns.

Meanwhile, the characteristics of the photosensitive laminate or the structural characteristics in which the photosensitive resin layer contains 5 bubbles/mm2 or less than 5 bubbles/mm2 having a diameter of less than 1 micrometer are attributable to the above-mentioned manufacturing method, or are attributable to Properties of the photosensitive resin layer.

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

Specific examples of the alkali-developable binder are not limited, but the alkali-developable binder may be a polymer or a copolymer comprising at least one repeating unit selected from the group consisting of repeating units represented by the following Chemical Formula 3 unit, 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.

In chemical formula 4, R ₃ is hydrogen or C1 to C10 alkyl,

In Chemical Formula 5, R ₄ is hydrogen or C1 to C10 alkyl, and R ₅ is C1 to C10 alkyl,

In Chemical Formula 6, Ar is a C6 to C20 aryl group.

In Chemical Formula 4 to Chemical Formula 6, R ₃ and R ₄ are the same or different from each other, and are each independently hydrogen or C1 to C10 alkyl, R ₅ is C1 to C10 alkyl, and Ar is C6 to C20 aryl.

In Chemical Formula 2 to Chemical Formula 4, R ₃ and R ₄ are the same or different from each other, and are each independently hydrogen or a C1 to C10 alkyl group, and a specific example of the C1 to C10 alkyl group may be a methyl group.

R ₅ is C1 to C10 alkyl, and a specific example of C1 to C10 alkyl may be methyl.

Ar is a C6 to C20 aryl group, and a specific example of the C6 to C20 aryl group may be a phenyl group.

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.

In Chemical Formula 4-1, R ₃ is hydrogen or C1 to C10 alkyl. In Chemical Formula 4-1, the description of R ₃ is the same as that described in Chemical Formula 4 above. Specific examples of the monomer represented by Chemical Formula 4-1 may 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]

In Chemical Formula 5-1, R ₄ is hydrogen or C1 to C10 alkyl, and R ₅ is C1 to C10 alkyl. In Chemical Formula 3-1, descriptions of R ₄ and R ₅ are the same as described in Chemical Formula 3 above. Specific examples of the monomer represented by Chemical Formula 3-1 may include methylmethacrylate (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.

In Chemical Formula 6-1, Ar is a C6 to C20 aryl group. In Chemical Formula 6-1, the description of Ar is the same as that described in Chemical Formula 4 above. A specific example of the monomer represented by Chemical Formula 6-1 may include styrene (SM).

Meanwhile, the alkaline developable binder resin containing a carboxyl group can serve as a substrate for the photosensitive resin layer, and thus should have a minimum molecular weight, for example, 20,000 g/mol to 300,000 g/mol, or 30,000 g/mol to 150,000 g/mol Molar weight average molecular weight.

In addition, the alkaline developable binder resin containing a carboxyl group should have a certain level or higher of heat resistance and thus may have a glass transition temperature of 20°C or more and 150°C or less.

In addition, the alkali developable binder resin containing a carboxyl group may have an acid value in a range of 100 mgKOH/g to 300 mgKOH/g in consideration of developability of the photosensitive resin layer.

Meanwhile, the photosensitive resin layer may include a cross-linked copolymer between a carboxyl group-containing alkaline developable binder resin and a photopolymerizable compound containing a (meth)acrylate monomer or oligomer.

Photopolymerizable compounds containing (meth)acrylate monomers or oligomers can act as crosslinkers to increase the mechanical strength of photosensitive resin layers, or can be used to increase resistance to developers and make cured films flexible .

The content of the photopolymerizable compound containing (meth)acrylate monomer or oligomer can be adjusted according to the specific use or characteristics of the photosensitive resin layer. For example, 1 to 80 parts by weight of a photopolymerizable compound containing a (meth)acrylate monomer or oligomer may be included based on 100 parts by weight of the alkaline developable binder resin containing a carboxyl group.

The photopolymerizable compound may be a monofunctional or multifunctional (meth)acrylate monomer or oligomer.

As the photopolymerizable compound, generally known monofunctional or polyfunctional (meth)acrylate monomers or oligomers can be used. In order to meet the above characteristics, 2 to 10 functional (meth)acrylate monomers or oligomers containing aromatic functional groups in the molecule can be used as monofunctional or polyfunctional (meth)acrylate monomers or oligomers things.

Specifically, the photopolymerizable compound may be a bifunctional (meth)acrylate compound represented by Chemical Formula 1 below.

[chemical formula 1]

In Chemical Formula 1, R ₁ and R ₂ are the same or different from each other and are H or CH ₃ , and each of j and k is an integer of 1 to 20.

More specifically, the bifunctional (meth)acrylate compound of Chemical Formula 1 may include a bifunctional (meth)acrylate compound of Chemical Formula 11 below and a bifunctional (meth)acrylate compound of Chemical Formula 12 below.

In Chemical Formula 11, R ₁₁ and R ₁₂ are the same or different from each other and are H or CH ₃ , and each of J1 and K1 is an integer of 1 to 8.

In Chemical Formula 12, R ₂₁ and R ₂₂ are the same or different from each other and are H or CH ₃ , and each of J2 and K2 is an integer of 10 to 20.

More specifically, the bifunctional (meth)acrylate compound of Chemical Formula 1 may include the bifunctional (meth)acrylate compound of Chemical Formula 11 and the bifunctional (meth)acrylate compound of Chemical Formula 12 in a weight ratio of 1:1 to 1:30. base) acrylate compounds.

Since the bifunctional (meth)acrylate compound of Chemical Formula 12 is used by the same weight or more than the bifunctional (meth)acrylate compound of Chemical Formula 11, the adhesion to the substrate and the resistance to the developer are increased. resistance, thereby ensuring excellent fine line adhesion and resolution.

Meanwhile, in addition to the bifunctional (meth)acrylate compound of chemical formula 1 and In addition, the photopolymerizable compound may further include a monofunctional or multifunctional (meth)acrylate compound. In this case, usable monofunctional or polyfunctional (meth)acrylate compounds exclude compounds contained in the bifunctional (meth)acrylate compounds of Chemical Formula 1.

Examples of photopolymerizable compounds that can be additionally used are not limited, but may 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 Trimethacrylate, Glycerin Dimethacrylate, Neopentylthritol Dimethacrylate, Neopentylthritol Trimethacrylate, Dineopentaerythritol pentamethacrylate, 2,2-bis(4-methacryloxydiethoxyphenyl)propane, 2,2-bis(4-methacryloxypolyethoxy Phenyl) propane, 2-hydroxy-3-methacryloxypropyl methacrylate, ethylene glycol diglycidyl ether dimethacrylate, diethylene glycol diglycidyl ether dimethacrylate, Diglycidyl phthalate dimethacrylate, glycerol polyglycidyl ether polymethacrylate, and polyfunctional (meth)acrylates containing urethane groups.

Meanwhile, the support substrate may serve as a support for the photosensitive laminate, and may facilitate handling of the photosensitive resin layer with adhesive strength during exposure.

Various plastic films can be used for the substrate film, and for example, at least one plastic film selected from the group consisting of acrylic film, polyethylene terephthalate (PET) film, triacetyl fiber can be used Triacetyl cellulose (TAC) film, polynorbornene (polynorbornene; PNB) film, cycloolefin polymer (cycloolefin polymer; COP) film and polycarbonate (polycarbonate; PC) film.

Meanwhile, the photosensitive laminate may further include a protective film formed to face the support substrate with the photosensitive resin layer at the center. The protective film prevents damage to the resist during handling and serves as a protective cover that protects the photosensitive resin layer from foreign substances such as dust, and may be laminated on the other surface of the photosensitive resin layer on which the substrate film is not formed .

The protective film is used to protect the photosensitive resin layer from external influences, and requires proper detachability and adhesion so that it is easy to release when the dry film photoresist is applied to post-processing, and does not release when stored and distributed.

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

According to another embodiment of the present disclosure, there is provided a method for preparing a photosensitive laminate, which includes the following steps: mixing a mixed solvent (including a high boiling point solvent with a boiling point of 115°C or higher and a boiling point of 100°C or lower) A resin composition containing a low boiling point solvent at 100°C); an alkaline developable adhesive resin containing carboxyl groups; and a photoinitiator are coated on the support substrate and then dried.

The photosensitive laminate described above in one embodiment can be provided according to the production method.

As described above, the photosensitive laminate includes a support substrate; and a photosensitive resin layer formed on the support substrate, wherein 5 bubbles/mm2 or less than 5 bubbles/square having a diameter of less than 1 micron exist in the photosensitive resin layer mm.

In the process of forming the photosensitive resin layer, due to such factors as the composition of the photosensitive resin Due to the bubbles generated during the preparation process of the composition solution or the drying process of the composition solution, bubbles with a diameter of less than 1 micron may be formed in the photosensitive resin layer. However, the photosensitive laminate production method uses a mixed solvent including 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 to delay the evaporation time of the photosensitive resin composition solution , whereby bubbles are prevented from being trapped in the resin layer, and thus 5 bubbles/mm2 or less than 5 bubbles/mm2 having a diameter of less than 1 micrometer may exist in the photosensitive resin layer.

More specifically, there may be 5 bubbles/mm2 or less, or 3 bubbles/mm2 or less than 3 bubbles/mm2 in the photosensitive resin layer, wherein the diameter of the bubbles is less than 1 micron.

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

Since air bubbles having a diameter of less than 1 micrometer exist in a trace amount or substantially do not exist on the opposite surface of the interface between the support substrate and the photosensitive resin layer or on the outer surface of the photosensitive resin layer, reliability is improved during development, thereby making it possible to High-density circuits are formed and defects in fine wiring formation can be reduced. Therefore, when the photosensitive laminate is used, high sensitivity to light exposure can be realized, and the production yield of high-density printed circuit boards can be improved.

As described above, the high boiling point solvent having a boiling point of 115° C. or higher may function to delay the evaporation time of the liquid components of the photosensitive resin composition so that air bubbles do not remain in the resin layer. Therefore, 5 bubbles/mm2 or less than 5 bubbles/mm2 having a diameter of less than 1 micrometer may exist in the photosensitive resin layer.

The mixed solvent may contain a boiling point of 115° C. in a predetermined amount or more Or a high boiling point solvent higher than 115°C, and for example, based on 100 parts by weight of the mixed solvent, may contain 3 parts by weight or more than 3 parts by weight, 5 parts by weight or more than 5 parts by weight, 3 parts by weight to 50 parts by weight or 5 parts by weight Parts by weight to 40 parts by weight of a high boiling point solvent having a boiling point of 115°C or higher.

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 solubility of the photosensitive resin composition can be increased.

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

More specifically, the mixed solvent contains a high boiling point solvent having a boiling point of 115°C or higher and a boiling point of 100°C or lower in a weight ratio of 1:2 to 1:20 or 1:3 to 1:15. low boiling point solvents. Since the high boiling point solvent with a boiling point of 115° C. or higher and the low boiling point solvent with a boiling point of 100° C. or lower are included in the above weight ratio, the solubility of the photosensitive resin composition can be increased.

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 diethyl ether, dipropylene glycol di Methyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether propionate, cyclohexanone, propylene glycol monomethyl ether acetate (PGMEA) and its mixed solvents.

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

In a resin composition containing a mixed solvent (including 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); an alkaline developable binder resin containing a carboxyl group; And in the photoinitiator, the solid content may be controlled in consideration of a specific use or application field, and for example, the resin composition may include 10 wt % to 99 wt % of a mixed solvent.

Meanwhile, methods or devices that can be used in the step of coating the resin composition on the support substrate followed by drying are not particularly limited. For example, the resin composition can be coated on a conventional substrate film such as polyethylene terephthalate 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 method can be used.

In the photosensitive laminate production method, in addition to using a mixed solvent including 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, by adjusting the drying rate and And/or drying temperature, the amount of microbubbles formed in the photosensitive resin layer can be greatly reduced or can be substantially absent.

More specifically, the step of drying the coated resin composition may be carried out at 50°C to 100°C, 60°C to 90°C, or 70°C to at a temperature of 85°C.

The drying time 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 description of the carboxyl group-containing alkali-developable binder resin contained in the resin composition includes the description described in the photosensitive laminate of Examples.

Alkaline developable binder resins containing carboxyl groups can have from 20,000 grams/mole to 300,000 grams/mole or from 30,000 grams/mole to 150,000 grams/mole The weight average molecular weight, and the glass transition temperature of not less than 20°C and not more than 150°C.

The alkaline developable binder resin containing carboxyl groups may have an acid value in the range of 100 mgKOH/g to 300 mgKOH/g.

The resin composition may further include a photopolymerizable compound containing a (meth)acrylate monomer or oligomer and an alkaline developable binder resin containing a carboxyl group.

Based on 100 parts by weight of the alkaline developable binder resin containing carboxyl groups, the resin composition may include 1 to 80 parts by weight of a photopolymerizable compound containing a (meth)acrylate monomer or oligomer.

As the photopolymerizable compound, generally known monofunctional or polyfunctional (meth)acrylate monomers or oligomers can be used. In order to meet the above characteristics, 2 to 10 functional (meth)acrylate monomers or oligomers containing aromatic functional groups in the molecule can be used as monofunctional or polyfunctional (meth)acrylate monomers or oligomers things.

Specifically, the photopolymerizable compound may be a bifunctional (meth)acrylate compound represented by Chemical Formula 1 below.

In Chemical Formula 1, R ₁ and R ₂ are the same or different from each other and are H or CH ₃ , and each of j and k is an integer of 1 to 20.

More specifically, the bifunctional (meth)acrylate compound of Chemical Formula 1 may include a bifunctional (meth)acrylate compound of Chemical Formula 11 below and a bifunctional (meth)acrylate compound of Chemical Formula 12 below.

[chemical formula 11]

In Chemical Formula 11, R ₁₁ and R ₁₂ are the same or different from each other and are H or CH ₃ , and each of J1 and K1 is an integer of 1 to 8.

In Chemical Formula 12, R ₂₁ and R ₂₂ are the same or different from each other and are H or CH ₃ , and each of J2 and K2 is an integer of 10 to 20.

More specifically, the bifunctional (meth)acrylate compound of Chemical Formula 1 may include the bifunctional (meth)acrylate compound of Chemical Formula 11 and the bifunctional (meth)acrylate compound of Chemical Formula 12 in a weight ratio of 1:1 to 1:30. base) acrylate compounds.

Since the bifunctional (meth)acrylate compound of Chemical Formula 12 is used by the same weight or more than the bifunctional (meth)acrylate compound of Chemical Formula 11, the adhesion to the substrate and the resistance to the developer are increased. resistance, thereby ensuring excellent fine line adhesion and resolution.

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

Compounds that can be used as photoinitiators may include anthraquinone derivatives, such as 2-methylanthraquinone and 2-ethylanthraquinone; and benzoin derivatives, such as benzoin methyl ether, benzophenone, phenanthrenequinone, and 4,4'-Bis(dimethylamino)benzophenone.

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-propoxythioxanthone, 1-(4-isopropylphenyl) 2-hydroxy-2-methylpropane- 1-ketone, 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 -Ethylhexyl ester, 2-isoamyl 4-dimethylaminobenzoate, 2,2-diethoxyacetophenone, benzophenone dimethyl acetal, benzophenone β-methoxy diethyl acetal, 1-phenyl-1,2-propyldioxime-o,o'-(2-carbonyl)ethoxyether, methyl phthaloylbenzoate, bis[4-di Methylaminophenyl) ketone, 4,4'-bis(diethylamino)benzophenone, 4,4'-dichlorobenzophenone, benzyl, benzoin, methoxybenzoin, ethoxy Base benzoin, isopropoxy benzoin, n-butoxy benzoin, isobutoxy benzoin, tertiary butoxy benzoin, p-dimethylaminoacetophenone, p-tertiary butyltrichloroacetophenone, p-three Grade butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzocycloheptanone, α,α-dichloro-4-phenoxybenzene Compounds selected from ethyl ketone and amyl 4-dimethylaminobenzoate can be used as photoinitiators, but are not limited thereto.

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

If the content of the photoinitiator is too low, the exposure amount should be increased due to the low light efficiency, which can greatly reduce the production efficiency. If the content of the photoinitiator is too high, the film may be brittle and the developer may be easily contaminated, causing defects such as short circuits.

In addition, the resin composition may further contain other additives as necessary. For example, dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, diallyl phthalate in the form of phthalates; triethylene glycol diacetate, tetraethylene glycol diacetate; p-toluenesulfonamide, benzenesulfonamide, n-butylbenzenesulfonamide in the form of amides; triphenyl phosphate and similar Those can be used as plasticizers.

In order to facilitate the handling of the resin composition, a leuco dye or colorant may be added. Examples of the leuco dye may include tris(4-dimethylamino-2-methylphenyl)methane, tris(4-dimethylamino-2-methylphenyl)methane, and fluorene dyes. Leuco crystal violet is preferred because of the good contrast. In the case of including a leuco dye, the content in the photosensitive resin composition may be 0.1% by weight or more and 10% by weight or less. In contrast, it is preferably 0.1% by weight or more, and in order to maintain storage stability, it is preferably 10% by weight or less.

Colorants may 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 the like. When a colorant is included, the amount added to the photosensitive resin composition may be 0.001% by weight or more and 1% by weight or less. If the content is 0.001% by weight or more, there is an effect of improving handling, and if the content is less than 1% by weight, there is an effect of maintaining storage stability.

Other additives may further include thermal polymerization inhibitors, dyes, decolorizers, tackifiers, and the like.

According to another embodiment of the present disclosure, a method for preparing a circuit board using the photosensitive laminate of the embodiment can be provided.

The photosensitive laminate of the embodiment can be used to be laminated on a copper clad laminate.

As an example of a circuit board or printed circuit board (PCB) manufacturing method, a pretreatment process is first performed to laminate a copper clad laminate, which is a raw material of the PCB. The pretreatment process is carried out in the order of drilling, deburring and washing in the outer layer process, and in the order of washing or pickling in the inner layer process. In the cleaning process, the bristle brush process and the jet pumice process are mainly used, and soft etching and sulfuric acid pickling can be performed on the pickling.

In order to form a circuit on a copper clad laminate that has undergone a pretreatment process, a photosensitive laminate or dry film photoresist (hereinafter referred to as DFR) is usually laminated on the copper layer of the copper clad laminate . 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 performed at a lamination rate of 0.5 m/min to 3.5 m/min, a temperature of 100° C. to 130° C., and a heated roll pressure of 10 psi to 90 psi.

The printed circuit board that has undergone the lamination process may be allowed to stand for 15 minutes or more to stabilize the substrate, and then the photoresist of the DFR may be exposed using a photomask having a desired circuit pattern formed thereon. In this process, when the photomask is irradiated with ultraviolet rays, the photoresist irradiated by ultraviolet rays can initiate polymerization in the irradiated part by the contained photoinitiator. Initially, the oxygen in the photoresist is consumed, and then the activated monomers are polymerized to cause a crosslinking reaction. Thereafter, as a large amount of monomer is consumed, a polymerization reaction may proceed, and an unexposed portion may exist in a state where a crosslinking reaction has not proceeded.

Subsequently, a development 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 developers. In this process, the photoresist in the unexposed part is washed away by the saponification reaction between the carboxylic acid of the binder polymer and the developer, and the cured Photoresist can remain on the copper surface.

Thereafter, depending on the inner layer process and the outer layer process, the circuit can be formed through different processes. In the inner layer process, circuits can be formed on the substrate by etching and lift-off processes. In the outer layer process, the circuit can be formed by electroplating process and tenting process, followed by etching and solder stripping.

For exposure, a conventionally known light source, more specifically, an ultra-high pressure mercury lamp or a laser direct exposure machine can be used.

[beneficial effect]

According to the present disclosure, there can be provided a photosensitive laminate capable of forming a high-density circuit by ensuring high reliability during development while reducing defects in fine wiring formation; a method of producing the above photosensitive laminate; and a circuit A plate production method using the above-mentioned photosensitive laminate.

The invention will be described in more detail in the following examples. However, the following examples are provided for illustrative purposes only, and the content of the present invention is not limited by the following examples.

<Preparation Example: Preparation of Alkaline Developable Binder Resin>

Preparation Example 1

A mechanical stirrer and a reflux device were installed in a four-neck round bottom flask, and then the inside of the flask was purged with nitrogen. 170 g of methyl ethyl ketone (MEK) and 12.5 g of methanol (MeOH) were added to a flask purged with nitrogen, and then 2.25 g of azobisisobutyronitrile (AIBN) were added thereto to dissolve it completely. Next, 60 grams of methacrylic acid (MAA), 100 grams of benzyl methacrylate (BzMA), 15 grams of methyl methacrylate (MMA) and 75 grams of gram of styrene (SM) monomer mixture, heated to a temperature of 80°C, and then polymerized for 6 hours to prepare alkaline developable binder resin 2 (weight average molecular weight 40,000 grams/mole, glass transition temperature 102°C, solid Content 50% by weight, acid value 156 mg KOH/gram).

The alkaline developable binder resin prepared in Preparation Example was dissolved in tetrahydrofuran at a concentration of 1.0 (w/w) % (about 0.5 (w/w) % in terms of solid content) in THF, and then 0.45 μm Filter through a pore size syringe filter, then inject 20 microliters into the GPC. The mobile phase of GPC was tetrahydrofuran (THF) at a flow rate of 1.0 ml/min, and the analysis was performed at 40°C. A column in which one Agilent PLgel 5 micron Guard (7.5×50 mm) and two Agilent PLgel 5 micron Mixed D (7.5×300 mm) were connected in series was used. And Agilent 1260 Infinity II system, RI detector was used for measurement at 40°C.

Polystyrene standard samples (STD A, STD B, STD C, STD D) obtained by dissolving polystyrene with various molecular weights in tetrahydrofuran at a concentration of 0.1 (w/w)% were passed through a 0.45 μm-bore needle Cartridge filter filtration and then injection into the GPC to obtain the weight average molecular weight (Mw) of the basic developable binder resin using a calibration curve formed therefrom.

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

<Example and Comparative Example: Preparation of Photosensitive Resin Composition and Dry Film Photoresist>

According to the composition shown 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 grease and mixed using a mechanical stirrer for about 1 hour to prepare a photosensitive resin composition.

Using a coating bar, the obtained photosensitive resin composition was coated on a 25 micron PET film. The coated photosensitive resin composition layer was dried in 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 photosensitive laminate (dry film resist) was prepared by laminating a protective film (polyethylene) on the dried photosensitive resin composition layer.

(1) M2101: bisphenol A (EO) ₁₀ dimethacrylate (Miwon Specialty Chemical)

(2) M281: polyethylene glycol dimethacrylate (American original special chemical)

(3) M241: bisphenol A (ethoxylate) ₄ dimethacrylate (American original special chemical)

(4) BCIM: 2,2'-bis(2-chlorophenyl-4,5,4',5'-tetraphenylbiimidazole (Aldrich Chemical)

[Comparative Example 3: Preparation of Photosensitive Resin Composition and Dry Film Photoresist]

Based on [0088] and [0093] of Patent Document 1, an experiment was conducted to reproduce Example 4 of Patent Document 1 (Japanese Laid-Open Patent Publication No. 2006-106287).

1. Preparation of photosensitive resin composition

Based on the description in Example 4 of Patent Document 1, the following components in terms of 300 parts by weight of "alkaline developable binder resin" obtained in Preparation Example 1 were mixed for about 1 hour using a mechanical stirrer to prepare a photosensitive resin Composition.

<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 dimethacrylate

(3) 50 parts by mass of polypropylene glycol diacrylate (the number of propylene glycol chains: 7)

(4) Photoinitiator: 25 parts by mass of benzophenone, 1.0 parts by mass of 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer and 1.0 parts by mass of diethylamine benzophenone

(5) The photochromic agent of 5.0 mass parts

(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) [boiling point is 100°C or Low boiling point solvent below 100°C: weight ratio of high boiling point solvent with boiling point at or above 115°C = 19:1]

2. Preparation of dry film photoresist

Using a coating bar, the obtained photosensitive resin composition was coated on a 25 micron PET film. The coated photosensitive resin composition layer was dried in 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.

<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 3.

1. Measure exposure (unit: mJ/cm2)

The dry film photoresist prepared in one of the Examples and Comparative Examples was laminated on a brush-polished copper clad laminate having a thickness of 1.6 mm. In this paper, HAKUTO MACH 610i is used for lamination, where the substrate preheating roller temperature is 120°C, laminator roll temperature of 115°C, roll pressure of 4.0 kgf/cm2 and roll speed of 2.0 min/m.

Using a 41-step flat panel manufactured by Stover Graphics and FDi-3 manufactured by ORC, the dry film photoresist laminated on the copper-clad laminate was irradiated with ultraviolet rays with a wavelength of 405 nm at an exposure dose, Make the number of remaining steps 15 steps, and then let it stand 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 coating method. At this time, the amount of energy when the determined remaining number of steps becomes 15 steps is measured.

2. Measurement 1:1 resolution (unit: micron)

The dry film photoresist prepared in one of the Examples and Comparative Examples was laminated on a brush-polished copper clad laminate having a thickness of 1.6 mm. In this paper, lamination was performed using HAKUTO MACH 610i with 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.

Forming data from 4 microns to 20 microns at 0.5 micron intervals such that the distance between the width of the circuit lines and the spacing between the circuit lines after development in the laminate becomes 1:1 using a Stover Graphics facility The 41-step plate and FDi-3 manufactured by ORC were irradiated with ultraviolet rays having a wavelength of 405 nm at an exposure amount such that the remaining steps were 15 steps, and then allowed to stand 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 coating method.

Thereafter, the resolution was determined by a value measured by using a ZEISS AXIOPHOT microscope to make the pitch between circuit lines and the pitch between non-circuit lines 1:1.

3. Confirm the air bubbles (unit: air bubbles/square millimeter)

Regarding the dry film photoresist prepared in one of the examples and comparative examples, After removing the PET film and the PE film, the number of bubbles (bubbles/mm2) present in the photosensitive resin layer (unit area: 1 mm×1 mm) with a diameter of less than 1 μm was confirmed using a polarizing microscope.

4. Confirm the defects after exposure/development (unit: defect/mm2)

The dry film photoresist prepared in one of the Examples and Comparative Examples was laminated on a brush-polished copper clad laminate having a thickness of 1.6 mm. In this paper, lamination was performed using HAKUTO MACH 610i with 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.

Using a 41-step flat panel manufactured by Stover Graphics Technology Equipment and FDi-3 manufactured by ORC, the laminate was irradiated with ultraviolet rays with a wavelength of 405 nm at an exposure amount so that the remaining steps were 15 steps in order to make the circuit lines The distance of width and spacing between circuit lines was 1:1 after development and then allowed to stand 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 coating method.

For each of the developed dry film resists prepared in Examples and Comparative Examples, 0.5 The number of defects (defects/mm²) of micrometers or more and 3 micrometers 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, manufactured by Hitachi, magnification 3000 times).

With reference to Table 1 and FIG. 1, it was confirmed that 1 bubble/mm2 or less than 1 bubble/mm2 with a diameter of less than 1 micrometer existed in the photosensitive resin layer of the photosensitive laminate of the example, and that there were no bubbles with a diameter of 1 micrometer or more. And large bubbles below 5 microns. In addition, even after exposing the photosensitive resin layer of Example to ultraviolet rays and developing with an alkaline solution, it was confirmed that substantially no defects with a diameter of 0.5 μm or more and 3 μm or less occurred, or 1 defect/mm2 or less Appears in the form of defects/mm².

In other words, it was also observed that since a small amount of air bubbles having a diameter of less than 1 micrometer existed in the photosensitive resin layer of the example, when a circuit board was prepared using a photosensitive laminate, high density and sensitivity were achieved while ensuring high reliability, whereby Finer wiring can be formed.

On the other hand, even when the energy equivalent to that of the example was used in the photosensitive resin laminate of the comparative example, and 10 bubbles/mm2 or more than 10 bubbles/mm2 having a diameter of less than 1 μm were present in the photosensitive resin layer, It is also difficult to achieve a resolution similar to the example.

Referring to Table 3 and FIG. 5, it was confirmed that after exposing the photosensitive resin layer obtained in one of Comparative Example 1 and Comparative Example 2, followed by development with an alkaline solution, many particles having a diameter of 0.5 μm or more and 3 μm or less appeared. defect.

Claims (22)

A photosensitive laminate comprising a support substrate; and a photosensitive resin layer formed on the support substrate, wherein there are 5 bubbles/mm2 or less than 5 bubbles/square diameter of less than 1 micrometer in the photosensitive resin layer square millimeters. The photosensitive laminate as claimed in claim 1, wherein there are presences having a diameter of less than 1 micron within 50% of the total thickness of the photosensitive resin layer on the opposite surface from the interface between the support substrate and the photosensitive resin layer 3 bubbles/mm2 or less than 3 bubbles/mm2. The photosensitive laminate according to claim 1, wherein the photosensitive resin layer does not contain bubbles having a diameter of not less than 1 micrometer and not more than 5 micrometers. The photosensitive laminate according to claim 1 or claim 2, wherein the supporting substrate has a thickness of 1 micron to 100 microns, and the photosensitive resin layer has a thickness of 1 micron to 100 microns. The photosensitive laminate according to claim 1, wherein the photosensitive resin layer has 3 defects/square millimeter or less with a cross-sectional diameter of 0.3 μm to 4 μm after exposure to ultraviolet rays and development with alkali Defects/mm². The photosensitive laminate according to claim 1, wherein the photosensitive resin layer includes an alkaline developable binder resin containing a carboxyl group. The photosensitive laminate as claimed in claim 6, wherein the photosensitive resin layer is included in the alkali-developable adhesive containing carboxyl groups A cross-linked copolymer between an agent resin and a photopolymerizable compound containing (meth)acrylate monomers or oligomers. The photosensitive laminate according to claim 7, wherein the photopolymerizable compound containing (meth)acrylate monomer or oligomer includes 2 to 10 functional groups ( Meth)acrylate monomer or oligomer. The photosensitive laminate according to claim 7, wherein the photopolymerizable compound containing a (meth)acrylate monomer or oligomer includes a bifunctional (meth)acrylate compound of the following chemical formula 1:

In Chemical Formula 1, R ₁ and R ₂ are the same or different from each other and are H or CH ₃ , and each of j and k is an integer of 1 to 20. The photosensitive laminate as claimed in claim 9, wherein the bifunctional (meth)acrylate compound of Chemical Formula 1 includes the bifunctional (meth)acrylic acid of the following Chemical Formula 11 in a weight ratio of 1:1 to 1:30 Ester compound and the difunctional (meth)acrylate compound of following chemical formula 12:

In Chemical Formula 11, R ₁₁ and R ₁₂ are the same or different from each other and are H or CH ₃ , and each of J1 and K1 is an integer of 1 to 8;

In Chemical Formula 12, R ₂₁ and R ₂₂ are the same or different from each other and are H or CH ₃ , and each of J2 and K2 is an integer of 10 to 20. The photosensitive laminate according to claim 7, wherein the alkali-developable binder resin containing a carboxyl group has a weight average molecular weight of 20,000 g/mole to 300,000 g/mole and a temperature of 20° C. to 150° C. glass transition temperature. The photosensitive laminate according to claim 7, wherein the alkali-developable binder resin containing a carboxyl group has an acid value in the range of 100 mgKOH/g to 300 mgKOH/g. A circuit board preparation method using the photosensitive laminate as described in claim 1. A method for preparing the photosensitive laminate as claimed in claim 1, comprising the steps of: making a resin composition containing a mixed solvent, the mixed solvent consisting of a high boiling point solvent with a boiling point of 115°C or higher and a boiling point of It is composed of a low boiling point solvent at or below 100°C; an alkaline developable adhesive resin containing carboxyl groups; and a photoinitiator coated on a support substrate and then dried. The method according to claim 14, wherein the content of the high boiling point solvent with a boiling point of 115°C or higher in the mixed solvent is 3% by weight or greater than 3% by weight. The method according to claim 14, wherein the mixed solvent includes the high boiling point solvent with a boiling point of 115°C or higher in a weight ratio of 1:2 to 1:20 and a boiling point of 100°C or lower than 100°C The low boiling point solvent of ℃. The method according to claim 14, wherein the high boiling point solvent having a boiling point of 115°C or higher includes at least one organic solvent selected from the group consisting of butanol, dimethylformamide, N-Methyl-2-Pyrrolidone, γ-Butyrolactone, Butyl Carbitol, Butyl Cellosolve, Methyl Cellosolve, Butyl Acetate, Diethylene Glycol Methyl Ether, Diethylene Glycol Dimethyl Ether , diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 3-methoxymethyl propionate, 3-ethoxy ethyl propionate, propylene glycol methyl ether propionate, cyclohexanone and propylene glycol monomethyl ether ethyl esters. The method according to claim 14, wherein the low-boiling solvent having a boiling point of 100°C or lower includes at least one organic solvent selected from the group consisting of: methyl ethyl ketone, methanol, ethanol, Acetone, tetrahydrofuran, and isopropanol. The method according to claim 14, wherein the resin composition further comprises a photopolymerizable compound comprising (meth)acrylate monomer or oligomer. The method according to claim 19, wherein the photopolymerizable compound containing (meth)acrylate monomers or oligomers includes 2 to 10 functional (methyl) compounds containing aromatic functional groups in the molecule Acrylate monomer or oligomer. The method as claimed in claim 14, wherein the alkaline developable binder resin containing carboxyl groups has 20,000 grams /mole to 300,000 g/mole weight average molecular weight and a glass transition temperature of not less than 20°C and not more than 150°C. The method according to claim 14, wherein the alkaline developable binder resin containing carboxyl groups has an acid value in the range of 100 mgKOH/g to 300 mgKOH/g.

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