TW202128788A - 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 [mu]m are present in the photosensitive resin layer.

Description

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

The present disclosure relates to a photosensitive laminate, a method for preparing a photosensitive laminate, and a method for preparing a circuit board. Cross reference of related applications

This application claims the Korean Patent Application No. 10-2019-0179860 filed with the Korean Intellectual Property Office on December 31, 2019, and the Korean Patent Application No. 10 filed on August 07, 2020. -2020-0099130 and Korean Patent Application No. 10-2020-0125243 filed on September 25, 2020, the disclosures of which are incorporated herein by reference in their entirety.

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

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

Therefore, there is a continuing need to develop methods and processes that achieve high density and sensitivity while ensuring higher reliability, and capable of forming finer wiring. [Prior Technical Literature] [Patent Literature] (Patent Document 1) Japanese Patent Publication No. 2006-106287 (Publication date: 2006.04.20.)

[technical problem]

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 the formation of fine wiring.

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

In the present disclosure, a method for manufacturing a circuit board is also provided, which uses the above-mentioned photosensitive laminate. [Technical Solution]

In the present disclosure, a photosensitive laminate is provided, which includes a supporting substrate; and a photosensitive resin layer formed on the supporting substrate, wherein there are 5 bubbles/mm 2 or less with a diameter of less than 1 micron in the photosensitive resin layer. 5 bubbles/mm2.

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

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

Hereinafter, the photosensitive laminate, the photosensitive laminate preparation method, and the circuit board preparation method 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 from polystyrene measured by GPC, commonly known analytical devices, detectors (such as refractive index detectors), and tubes for analysis can be used. And can apply the commonly used temperature conditions, solvents and flow rates.

As a specific example of measurement conditions, the alkaline developable binder resin is dissolved in tetrahydrofuran at a concentration of 1.0 (weight/weight)% (about 0.5 (weight/weight)% based on solid content) in THF, and then used After filtration through a 0.45 micron pore syringe filter, 20 microliters were injected into the GPC. The mobile phase of GPC is tetrahydrofuran (THF) and flows at a flow rate of 1.0 ml/min. Using one of the Agilent PLgel 5 micron Guard (7.5 × 50 mm) and two Agilent PLgel 5 micron Mixed D (7.5 × 300 mm) columns connected in series, and the Agilent 1260 Infinity II system, the RI detector is used at 40°C Measure under.

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 (weight/weight)% pass through a 0.45 micron aperture needle The cartridge filter is filtered, and then injected into the GPC to obtain the weight average molecular weight (Mw) of the alkaline developable binder resin using the 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 "(light) cured product" or "(light) cured" not only includes 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 group Partially cured, cross-linked or polymerized.

According to an embodiment of the present disclosure, there is provided a photosensitive laminate, which includes a support substrate; and a photosensitive resin layer, which includes a photopolymerizable compound (containing a multifunctional (meth)acrylic acid having three or more functional groups). Ester compound) and alkaline developable adhesive resin, in which there are 5 bubbles/mm2 or less than 5 bubbles/mm2 with a diameter of less than 1 micron in the photosensitive resin layer.

The inventors have newly developed a photosensitive laminate comprising a photosensitive resin layer, in which there are 5 bubbles/mm2 or less than 5 bubbles/mm2 with a diameter of less than 1 micrometer. It has been confirmed by experiments that the use of this photosensitive laminate can have high sensitivity to exposure during the process of preparing circuit boards, and improve reliability during development, thereby ensuring high reliability, achieving high density and sensitivity, and being able to Form a finer wiring.

The inventors have continued to conduct research and development to remove traces of microbubbles or fine by-products that may appear during the preparation process due to various reasons, and use mixed solvents (including high boiling points with a boiling point of 115°C or higher Boiling point solvents and low boiling point solvents with a boiling point of 100°C or lower), an alkaline developable binder resin, a photopolymerizable compound, and a photoinitiator to form a photosensitive resin layer, so that the photosensitive resin layer There are 5 bubbles/mm2 or less than 5 bubbles/mm2, or 3 bubbles/mm2 or less than 3 bubbles/mm2 with a diameter of less than 1 micron.

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 drying is adjusted by The rate and/or drying temperature may be greatly reduced or may 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, where the diameter of the bubbles is less than 1 micron . In particular, bubbles with a diameter of less than 1 micrometer may be present in trace amounts or may be substantially absent 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, 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, there may be 3 bubbles/mm2 or less than 3 bubbles with a diameter of less than 1 micron /Square millimeter.

Since bubbles with a diameter of less than 1 micron are present in trace amounts or substantially absent 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, the reliability during development is improved, thereby enabling High-density circuits are formed and defects in the formation of fine wiring can be reduced. Therefore, when a photosensitive laminate is used, high sensitivity to exposure can be achieved, and the production yield of high-density printed circuit boards can be improved.

In addition, in the photosensitive laminate, not only bubbles with a diameter of less than 1 micrometer may be present in a trace amount or may be substantially absent, but also bubbles with a diameter of 1 micrometer to 5 micrometers may not be present.

In this way, when a photosensitive laminate in which a small amount of air bubbles having a diameter of less than 1 micron are present in the photosensitive resin layer is used in the preparation of a circuit board, it is possible to achieve high density and sensitivity while ensuring high reliability, and it is possible to form finer Wiring.

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

Specifically, after exposing the photosensitive resin layer to ultraviolet rays and then developing it with an alkaline solution, 3 defects/mm2 or less than 3 defects/mm2, or 1 defect/mm2 or less can be observed 1 defect per square millimeter, or there may be substantially no defects, wherein the cross-sectional diameter of the defect is 0.3 micrometers to 4 micrometers, or 0.5 micrometers or more and 3 micrometers or less. The cross-sectional diameter of the defect may be defined as the largest diameter among the defect diameters defined in the cross-section in one direction on the photosensitive resin layer.

The conditions of exposure and development are not particularly limited. For example, a certain amount of energy can be used for exposure, so that the remaining number of steps is 15 steps, lasting from 1 minute to 60 minutes, and the 41-step tablet manufactured by Stouffer Graphic Arts Equipment is used at 340 Na Measure the light irradiated to the photosensitive laminate in the range of meters to 420 nanometers. In addition, development can be performed by a method (such as a spray method) using _{an alkaline aqueous solution (such as Na 2} CO ₃ ) having a concentration of 0.1% to 3.0% by weight.

In addition, when a photosensitive laminate is used, it is possible to achieve higher density and sensitivity while using less energy. More specifically, the amount of energy required to make the remaining steps 15 steps can be 300 mJ/cm² or less than 300 mJ/cm², or 100 mJ/cm² or less than 100 mJ/cm², where A 41-step flat panel manufactured by Stover graphic technology equipment was used to measure the light irradiated to the photosensitive laminate in the range of 340 nm to 420 nm. 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 micrometer to 100 micrometers, or 5 micrometers to 50 micrometers, and the thickness of the photosensitive resin layer may be 1 micrometer. Micron to 100 microns, or 5 microns to 50 microns.

At the same time, 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 with a diameter of less than 1 micron can be attributed to the above-mentioned preparation method, or can be attributed to The characteristics of the photosensitive resin layer.

In particular, the photosensitive resin layer may include an alkaline developable binder resin. The alkaline developable binder may contain at least one carboxyl group in the molecule and may react with alkali during development.

在化學式4中，R₃ 為氫或C1至C10烷基， [化學式5]

在化學式5中，R₄ 為氫或C1至C10烷基，且R₅ 為C1至C10烷基， [化學式6]

在化學式6中，Ar為C6至C20芳基。Specific examples of the alkaline developable adhesive are not limited, but the alkaline developable adhesive may be a polymer or copolymer containing at least one repeating unit selected from the group consisting of: a repeat represented by the following chemical formula 4 The unit, the repeating unit represented by the following Chemical Formula 5, and the repeating unit represented by the following Chemical Formula 6. [Chemical formula 4]

In Chemical Formula 4, R ₃ is hydrogen or a C1 to C10 alkyl group, [Chemical Formula 5]

In the chemical formula 5, R ₄ is hydrogen or a C1 to C10 alkyl group, and R ₅ is a C1 to C10 alkyl group, [Chemical formula 6]

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 a C1 to C10 alkyl group, R ₅ is a C1 to C10 alkyl group, and Ar is a C6 to C20 aryl group.

R ₅ is a C1 to C10 alkyl group, and a specific example of the C1 to C10 alkyl group may be a methyl group. 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. [Chemical formula 4-1]

In the chemical formula 4-1, R ₃ is hydrogen or a C1 to C10 alkyl group. 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 the chemical formula 5-1, R ₄ is hydrogen or a C1 to C10 alkyl group, and R ₅ is a C1 to C10 alkyl group. In Chemical Formula 3-1, the descriptions of R ₄ and R ₅ are the same as those described in Chemical Formula 3 above. Specific examples of the monomer represented by Chemical Formula 3-1 may include methyl methacrylate (MMA) and butyl acrylate (BA).

The repeating unit represented by Chemical Formula 6 may be a repeating unit derived from a monomer represented by the following Chemical Formula 6-1. [Chemical formula 6-1]

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).

At the same time, the alkaline developable adhesive resin can serve as the substrate of the photosensitive resin layer, and therefore should have a minimum molecular weight, such as 20,000 g/mole to 300,000 g/mole, or 30,000 g/mole to 150,000 g/mole Weight average molecular weight.

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

In addition, considering the developability of the photosensitive resin layer, the alkaline developable binder resin may have an acid value in the range of 100 mg KOH/gram to 300 mg KOH/gram.

Meanwhile, the alkaline developable adhesive resin may include two or more alkaline developable adhesives having different types or different characteristics. In particular, the alkaline developable adhesive resin may include a first alkaline developable adhesive resin and a second alkaline developable adhesive resin.

The first alkaline developable adhesive resin and the second alkaline developable adhesive resin may have a weight average molecular weight of 30,000 g/mol or more and 150,000 g/mol or less and a glass transition temperature of 20°C or more and 150°C or less , And can each have a different weight average molecular weight, glass transition temperature or acid value.

For example, the first alkaline developable adhesive resin may have an acid value of 140 mg KOH/gram or more and 160 mg KOH/gram or less. In addition, the second alkaline developable adhesive resin may have an acid value of 160 mg KOH/g or more and 200 mg KOH/g or less.

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

In addition, the acid value ratio of the first alkaline developable adhesive resin to the second alkaline developable adhesive resin may be 1:1.01 or more and 1:1.5 or less, 1:1.1 or more and 1:1.5 or less, and 1:1.25 Above and 1:1.5 or less or 1:1.4 or more and 1:1.5 or less.

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

The photopolymerizable compound containing (meth)acrylate monomer or oligomer can act as a crosslinking agent to increase the mechanical strength of the photosensitive resin layer, or can be used to increase the resistance to the developer and make the cured film flexible .

According to the specific use or characteristics of the photosensitive resin layer, the content of the photopolymerizable compound containing the (meth)acrylate monomer or oligomer can be adjusted. For example, based on 100 parts by weight of the alkaline developable binder resin, the photopolymerizable compound containing (meth)acrylate monomers or oligomers may be included in an amount of 1 to 80 parts by weight.

The photopolymerizable compound may be a monofunctional or multifunctional (meth)acrylate monomer or oligomer. The photopolymerizable compound may be a generally known monofunctional or polyfunctional (meth)acrylate monomer or oligomer, but in order for the photosensitive resin layer to satisfy the above-mentioned characteristics, the photopolymerizable compound may contain three or more Multifunctional (meth)acrylate compound with three functional groups.

That is, the photosensitive laminate of the example uses two or more solvents with different boiling points, as described in the preparation method described below. Therefore, depending on the photopolymerizable compound to be used, microbubbles may be present in a trace amount in the photosensitive resin layer or may be substantially absent.

In particular, the polyfunctional (meth)acrylate compound having three or more functional groups may have three or more C1 to C10 alkylene oxide groups and three or more (methyl) ) A structure in which an acrylate functional group is bonded to a C1 to C20 central group.

Due to the structure of the polyfunctional (meth)acrylate compound having three or more functional groups, a small amount of bubbles with a diameter of 1 micron or less may exist in the photosensitive resin layer, thereby reducing the formation of fine wiring Defects. In addition, it is possible to provide a photosensitive laminate capable of forming a high-density circuit by ensuring high reliability during development.

在化學式1中，R₄ 為氫或C1至C10烷基，R₅ 為C1至C10伸烷基，R₆ 為含有C1至C20中心基團的p價官能基，n2為1至20的整數，且p為取代R₆ 的官能基的數目，且為3至10整數。More specifically, the polyfunctional (meth)acrylate compound having three or more functional groups may include the compound of the following Chemical Formula 1: [Chemical Formula 1]

In Chemical Formula 1, R ₄ is hydrogen or a C1 to C10 alkyl group, R ₅ is a C1 to C10 alkylene group, R ₆ is a p-valent functional group containing a C1 to C20 central group, n2 is an integer from 1 to 20, And p is _{the number of functional groups substituted for R 6} and is an integer of 3 to 10.

在化學式1-1中， R₆ '為C1至C10三價官能基， R₇ 至R₉ 各自獨立地為C1至C10伸烷基， R₁₀ 至R₁₂ 各自獨立地為氫或C1至C10烷基，以及 n3至n5各自獨立地為1至3的整數。More specific examples of the compound of Chemical Formula 1 may include the compound of Chemical Formula 1-1 below. [Chemical formula 1-1]

In the chemical formula 1-1, R ₆ ′ is a C1 to C10 trivalent functional group, R ₇ to R ₉ are each independently a C1 to C10 alkylene group, and R ₁₀ to R ₁₂ are each independently hydrogen or a C1 to C10 alkane. The base, and n3 to n5 are each independently an integer of 1 to 3.

Meanwhile, the photopolymerizable compound may further contain a monofunctional (meth)acrylate compound or a bifunctional (meth)acrylate compound.

The monofunctional (meth)acrylate compound may include a (meth)acrylate containing a C1 to C10 alkylene oxide group.

在化學式2中，R₁ 為氫或C1至C10烷基，R₂ 為C1至C10伸烷基，R₃ 為C1至C10烷基，且n1為1至20的整數。In particular, the monofunctional (meth)acrylate compound may include a monofunctional (meth)acrylate compound represented by the following Chemical Formula 2. [Chemical formula 2]

In Chemical Formula 2, R ₁ is hydrogen or a C1 to C10 alkyl group, R ₂ is a C1 to C10 alkylene group, R ₃ is a C1 to C10 alkyl group, and n1 is an integer of 1 to 20.

The photopolymerizable compound may contain the above-mentioned monofunctional (meth)acrylate compound and a multifunctional (meth)acrylate compound having three or more functional groups at the same time. In particular, the photopolymerizable compound may contain a monofunctional (meth)acrylate compound including a (meth)acrylate containing a C1 to C10 alkylene oxide group; and A polyfunctional (meth)acrylate compound having three or more functional groups, which has three or more C1 to C10 alkylene oxide groups and three or more (meth)acrylates The structure where the functional group is bonded to the C1 to C20 central group.

Considering the characteristics of the photosensitive resin layer and the photosensitive laminate, the monofunctional (meth)acrylate compound contained in the photopolymerizable compound and the multifunctional (meth)acrylic acid having three or more functional groups can be adjusted The content of ester compounds.

For example, based on 100 parts by weight of the monofunctional (meth)acrylate compound, the photopolymerizable compound may contain 110 parts by weight or more and 500 parts by weight or less of a polyfunctional (meth)acrylate compound having three or more functional groups. Base) Acrylate compound.

In addition, based on 100 parts by weight of the polyfunctional (meth)acrylate compound having three or more functional groups, the photopolymerizable compound may contain 500 parts by weight or more and 1000 parts by weight or less of a difunctional (meth)acrylate compound. Acrylate compound.

At the same time, the photopolymerizable compound may further contain a monofunctional or polyfunctional (meth)acrylate compound, which is different from a monofunctional (meth)acrylate compound and a polyfunctional (meth)acrylate compound having three or more functional groups. ) Acrylate compound. In this case, the usable monofunctional or polyfunctional (meth)acrylate compound excludes the polyfunctional (meth)acrylate compound having three or more functional groups of Chemical Formula 1 and the monofunctional (meth)acrylate compound of Chemical Formula 2 ( Meth)acrylate compound.

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 acrylate Acrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethyl Acrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, glycerol dimethacrylate, neopentyl erythritol dimethacrylate, neopentaerythritol 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)acrylate containing urethane groups.

At the same time, the support substrate can serve as a support for the photosensitive laminate, and can help process the photosensitive resin layer with bonding 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 (PNB) film, cycloolefin polymer (COP) film and polycarbonate (PC) film.

At the same time, the photosensitive laminate may further include a protective film formed to face the supporting substrate with the photosensitive resin layer as the center. The protective film prevents damage to the resist during processing and serves as a protective cover to protect 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 separation and adhesion so that it is easy to release when the dry film photoresist is applied to post-processing, and will not be released during storage and distribution.

Various plastic films can be used for the protective film, and for example, at least one selected from the group consisting of acrylic film, polyethylene (PE) film, and polyethylene terephthalate (PET) can be used. Films, triacetyl cellulose (TAC) films, polynorbornene (PNB) films, cycloolefin polymer (COP) films, and polycarbonate (PC) films. Although the thickness of the protective film is not particularly limited, for example, it can be freely adjusted within 0.01 micrometers to 100 micrometers.

According to another embodiment of the present disclosure, a method for preparing a photosensitive laminate is provided, which includes the following steps: mixing a solvent containing 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) (Low boiling point solvent at 100°C) resin composition; photopolymerizable compound containing polyfunctional (meth)acrylate compound having three or more functional groups; alkaline developable binder resin; and photopolymerization The initiator is coated on the supporting substrate and then dried, The mixed solvent includes 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 in a weight ratio of 1:2 to 1:18.

The photosensitive laminate described in an embodiment above can be provided according to the preparation method. As described above, the photosensitive laminate includes a supporting substrate; and a photosensitive resin layer including a photopolymerizable compound (containing a multifunctional (meth)acrylate compound having three or more functional groups) and an alkaline Develop binder resin. There may be 5 bubbles/mm2 or less than 5 bubbles/mm2 with a diameter of less than 1 micrometer in the photosensitive resin layer.

In the process of forming the photosensitive resin layer, due to reasons such as bubbles generated during the preparation process of the photosensitive resin composition solution or the drying process of the composition solution, bubbles having a diameter of less than 1 micron may be formed in the photosensitive resin layer. However, the photosensitive laminate preparation method uses 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 to delay the evaporation time of the photosensitive resin composition solution , Thereby preventing air bubbles from staying in the resin layer, and therefore there may be 5 air bubbles/mm2 or less than 5 air bubbles/mm2 with a diameter of less than 1 micrometer in the photosensitive resin layer.

More specifically, there may be 5 bubbles/mm2 or less than 5 bubbles/mm2, 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, 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, there may be 3 bubbles/mm2 or less than 3 bubbles having a diameter of less than 1 micrometer.

Since bubbles with a diameter of less than 1 micron are present in trace amounts or substantially absent 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, the reliability during development is improved, thereby enabling High-density circuits are formed and defects in the formation of fine wiring can be reduced. Therefore, when a photosensitive laminate is used, high sensitivity to exposure can be achieved, and the production yield of high-density printed circuit boards can be improved.

As described above, the high-boiling point solvent with a boiling point of 115°C or higher can function to delay the evaporation time of the liquid component of the photosensitive resin composition, so that bubbles do not stay in the resin layer. Therefore, there may be 5 bubbles/mm2 or less than 5 bubbles/mm2 with a diameter of less than 1 micrometer in the photosensitive resin layer.

The mixed solvent may include a high boiling point solvent having a boiling point of 115°C or higher in a predetermined amount or more, and for example, based on 100 parts by weight of the mixed solvent, may contain 3 parts by weight or more, 5 parts by weight or more, 3 parts by weight to 50 parts by weight, or 5 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 include a low boiling point solvent having a boiling point of 100°C or lower, and the content thereof is higher 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 with a boiling point of 115°C or higher than 115°C and a boiling point of 100°C or lower in a weight ratio of 1:2 to 1:18 or 1:3 to 1:15 The low boiling point solvent. Since 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 are included in the above weight ratio, the solubility of the photosensitive resin composition can be increased.

Examples of high boiling point solvents with a boiling point of 115°C or higher may include butanol, dimethylformamide, N-methyl-2-pyrrolidone, gamma butyrolactone, butyl carbitol (butyl carbitol) capitol, butyl cellosolve, methyl cellosolve, butyl acetate, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol two Methyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, propylene glycol monomethyl ether acetate (propylene glycol monomethyl ether acetate; PGMEA) and its mixed solvents.

Examples of the low boiling point 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; and In the starting agent, the solid content can be controlled in consideration of a specific use or application field, and for example, the resin composition can include a mixed solvent of 10% to 99% by weight.

At the same time, the method or device that can be used in the step of coating the resin composition on the supporting substrate followed by drying is not particularly limited. For example, the resin composition may 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 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, by adjusting the drying rate and /Or the drying temperature may greatly reduce or may not substantially exist in the amount of microbubbles formed in the photosensitive resin layer.

More specifically, the step of drying the coated resin composition can be performed by heating a member (such as a hot air oven, a hot plate, a hot air circulation furnace or an infrared furnace) at 50°C to 100°C, 60°C to 90°C, or 70°C to Performed 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 alkaline developable binder resin contained in the resin composition includes the description described in the photosensitive laminate of the examples.

The alkaline developable adhesive resin may have a weight average molecular weight of 20,000 g/mol to 300,000 g/mol or 30,000 g/mol to 150,000 g/mol, and a glass transition temperature above 20°C and below 150°C.

The alkaline developable binder resin may have an acid value in the range of 100 mg KOH/gram to 300 mg KOH/gram.

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

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

The description of the photopolymerizable compound includes the description described in the photosensitive laminate of the Examples.

The photopolymerizable compound may be a monofunctional or multifunctional (meth)acrylate monomer or oligomer. The photopolymerizable compound may be a generally known monofunctional or polyfunctional (meth)acrylate monomer or oligomer, but in order for the photosensitive resin layer to satisfy the above-mentioned characteristics, the photopolymerizable compound may contain three or more Multifunctional (meth)acrylate compound with three functional groups.

In the preparation method of the photosensitive laminate of the embodiment, two or more solvents having different boiling points are used. Therefore, depending on the photopolymerizable compound to be used, microbubbles may be present in a trace amount in the photosensitive resin layer or may be substantially absent.

In particular, the polyfunctional (meth)acrylate compound having three or more functional groups may have three or more C1 to C10 alkylene oxide groups and three or more (methyl) ) A structure in which an acrylate functional group is bonded to a C1 to C20 central group.

Due to the structure of the polyfunctional (meth)acrylate compound having three or more functional groups, a small amount of bubbles with a diameter of 1 micron or less may exist in the photosensitive resin layer, thereby reducing the formation of fine wiring Defects. In addition, it is possible to provide a photosensitive laminate capable of forming a high-density circuit by ensuring high reliability during development.

在化學式1中，R₄ 為氫或C1至C10烷基，R₅ 為C1至C10伸烷基，R₆ 為含有C1至C20中心基團的p價官能基，n2為1至20的整數，且p為取代R₆ 的官能基的數目，且為3至10整數。More specifically, the polyfunctional (meth)acrylate compound having three or more functional groups may include the compound of the following Chemical Formula 1: [Chemical Formula 1]

In Chemical Formula 1, R ₄ is hydrogen or a C1 to C10 alkyl group, R ₅ is a C1 to C10 alkylene group, R ₆ is a p-valent functional group containing a C1 to C20 central group, n2 is an integer from 1 to 20, And p is _{the number of functional groups substituted for R 6} and is an integer of 3 to 10.

在化學式1-1中，R₆ '為C1至C10三價官能基，R₇ 至R₉ 各自獨立地為C1至C10伸烷基，R₁₀ 至R₁₂ 各自獨立地為氫或C1至C10烷基，且n3至n5各自獨立地為1至3的整數。More specific examples of the compound of Chemical Formula 1 may include the compound of Chemical Formula 1-1 below. [Chemical formula 1-1]

In Chemical Formula 1-1, R ₆ ′ is a C1 to C10 trivalent functional group, R ₇ to R ₉ are each independently a C1 to C10 alkylene group, and R ₁₀ to R ₁₂ are each independently hydrogen or a C1 to C10 alkane. Base, and n3 to n5 are each independently an integer of 1 to 3.

Meanwhile, the photopolymerizable compound may further contain a monofunctional (meth)acrylate compound or a bifunctional (meth)acrylate compound.

The monofunctional (meth)acrylate compound may include a (meth)acrylate containing a C1 to C10 alkylene oxide group.

在化學式2中，R₁ 為氫或C1至C10烷基，R₂ 為C1至C10伸烷基，R₃ 為C1至C10烷基，且n1為1至20的整數。In particular, the monofunctional (meth)acrylate compound may include a monofunctional (meth)acrylate compound represented by the following Chemical Formula 2. [Chemical formula 2]

In Chemical Formula 2, R ₁ is hydrogen or a C1 to C10 alkyl group, R ₂ is a C1 to C10 alkylene group, R ₃ is a C1 to C10 alkyl group, and n1 is an integer of 1 to 20.

The photopolymerizable compound may contain the above-mentioned monofunctional (meth)acrylate compound and a multifunctional (meth)acrylate compound having three or more functional groups at the same time. In particular, the photopolymerizable compound may contain a monofunctional (meth)acrylate compound including a (meth)acrylate containing a C1 to C10 alkylene oxide group; and A polyfunctional (meth)acrylate compound having three or more functional groups, which has three or more C1 to C10 alkylene oxide groups and three or more (meth)acrylates The structure where the functional group is bonded to the C1 to C20 central group.

Considering the characteristics of the photosensitive resin layer and the photosensitive laminate, the monofunctional (meth)acrylate compound contained in the photopolymerizable compound and the multifunctional (meth)acrylic acid having three or more functional groups can be adjusted The content of ester compounds.

For example, based on 100 parts by weight of the monofunctional (meth)acrylate compound, the photopolymerizable compound may contain 110 parts by weight or more and 500 parts by weight or less of a polyfunctional (meth)acrylate compound having three or more functional groups. Base) Acrylate compound.

In addition, based on 100 parts by weight of the polyfunctional (meth)acrylate compound having three or more functional groups, the photopolymerizable compound may contain 500 parts by weight or more and 1000 parts by weight or less of a difunctional (meth)acrylate compound. Acrylate compound.

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

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.

Choose 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-morpholinyl-1-one, 2-benzyl-2 -Dimethylamino-1-[4-morpholinophenyl]butan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethyl Benzyl diphenyl phosphine oxide, 1-[4-(2-hydroxymethoxy)phenyl]-2-hydroxy-2-methylpropan-1-one, 2,4-diethylthio Xanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 3,3-dimethyl-4-methoxybenzophenone, benzophenone, 1-chloro-4- Propoxythioxanthone, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2 -Methyl propan-1-one, 4-benzyl-4'-methyl dimethyl sulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, 4-bis Ethyl methylaminobenzoate, butyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2-isoamyl 4-dimethylaminobenzoate, 2, 2-diethoxy acetophenone, benzyl ketone dimethyl acetal, benzyl ketone β-methoxydiethyl acetal, 1-phenyl-1,2-propyl dioxime-o, o'-(2-carbonyl)ethoxy ether, methyl phthalate, bis[4-dimethylaminophenyl)ketone, 4,4'-bis(diethylamino)diphenyl Methyl ketone, 4,4'-dichlorobenzophenone, benzyl, benzoin, methoxy benzoin, ethoxy benzoin, isopropoxy benzoin, n-butoxy benzoin, isobutoxy benzoin, three Grade butoxybenzoin, p-dimethylaminoacetophenone, p-tertiary butyl trichloroacetophenone, p-tertiary butyl dichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2 -Isopropyl thioxanthone, dibenzocycloheptanone, α,α-dichloro-4-phenoxyacetophenone, and 4-dimethylaminobenzoic acid pentyl selected compounds can be used as photoinitiators Agent, but not limited to this.

Based on the solid content, the photoinitiator may be included in an amount of 0.1% by weight to 20% by weight, or 1% by weight or more and 10% by weight or less, relative to the total weight of the resin composition. 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 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, thereby causing defects such as short circuits.

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

In order to facilitate the processing of the resin composition, a leuco dye or colorant may be added. Examples of leuco dyes may include tris(4-dimethylamino-2-methylphenyl)methane, tris(4-dimethylamino-2methylphenyl)methane, and fluorene dyes. It is preferable to use colorless crystal violet because of good contrast. In the case where the leuco dye is included, 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 than 10% by weight.

The colorant may include toluene sulfonic 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 than 0.001% by weight, there is an effect of improving processing, 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, fading agents, tackifiers, and the like.

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

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

As an example of a method for preparing a circuit board or a printed circuit board (PCB), a pretreatment process is first performed to laminate a copper-clad laminate, which is the original 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 washing process, the hard 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 the copper-clad laminate that has undergone a pretreatment process, usually a photosensitive laminate or dry film photoresist (hereinafter referred to as DFR) can be 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 the protective film of DFR is peeled off using a laminator. Generally speaking, 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 heating roller pressure of 10 psig to 90 psig.

The printed circuit board that has undergone the lamination process can be allowed to stand for 15 minutes or more to stabilize the substrate, and then a photomask having a desired circuit pattern formed thereon can be used to expose the photoresist of the DFR. 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 monomer is polymerized to cause a cross-linking reaction. Thereafter, as a large amount of monomer is consumed, polymerization reaction may proceed, and the unexposed portion may exist in a state where no crosslinking reaction has proceeded.

Subsequently, a development process of removing the unexposed part of the photoresist is performed. In the case of alkaline developable DFR, 0.8% to 1.2% by weight of potassium carbonate and sodium carbonate aqueous solution can be used as a developer. In this process, the photoresist in the unexposed part is cleaned 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.

After that, depending on the inner layer process and the outer layer process, circuits can be formed through different processes. In the inner layer process, the circuit can be formed on the substrate through the etching and stripping process. In the outer layer manufacturing process, a circuit can be formed by an electroplating process and a tenting process, followed by etching and solder stripping.

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

According to the present disclosure, it is possible to provide a photosensitive laminate capable of forming a high-density circuit by ensuring high reliability during development while reducing defects in the formation of fine wiring; a method for preparing the above photosensitive laminate; and a circuit A method for preparing a plate using the above-mentioned photosensitive laminate.

The present 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 adhesive resin > Preparation example 1

A mechanical stirrer and a reflux device were installed in a four-necked round bottom flask, and then the inside of the flask was purged with nitrogen. 170 grams of methyl ethyl ketone (MEK) and 12.5 grams of methanol (MeOH) were added to a flask purged with nitrogen, and then 2.25 grams of azobisisobutyronitrile (AIBN) were added thereto So as to completely dissolve. Then, 60 grams of methacrylic acid (MAA), 100 grams of benzyl methacrylate (BzMA), 15 grams of methyl methacrylate (MMA), and 75 grams of styrene (SM) were added as monomers. The mixture was 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 g/mol, glass transition temperature 102°C, solid content 50% by weight, acid value 156 Mg KOH/g). Measure the weight average molecular weight ( Mw ) of alkaline developable adhesive resin

The alkaline developable binder resin prepared in one of Preparation Example 1 and Preparation Example 2 was dissolved at a concentration of 1.0 (weight/weight)% (about 0.5 (weight/weight)% based on solid content) in THF In tetrahydrofuran, and then filtered using a 0.45 micron pore size syringe filter, then 20 microliters were injected into the GPC. The mobile phase of GPC is tetrahydrofuran (THF) and flows at a flow rate of 1.0 ml/min, and the analysis is performed at 40°C. Use one Agilent PLgel 5 micron Guard (7.5 × 50 mm) and two Agilent PLgel 5 micron Mixed D (7.5 × 300 mm) columns connected in series. And the Agilent 1260 Infinity II system, the RI detector is 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 (weight/weight)% pass through a 0.45 micron aperture needle The cartridge filter is filtered, and then injected into the GPC to obtain the weight average molecular weight (Mw) of the alkaline developable binder resin using the 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 < Examples and comparative examples : 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 and mixed with a mechanical stirrer for about 1 hour to prepare Photosensitive resin composition.

Using a coating bar, the obtained photosensitive resin composition was coated on a 16-micron PET film. A hot air oven was used to dry the coated photosensitive resin composition layer, where the drying temperature was 80° C., the drying time was 5 minutes, and the thickness of the photosensitive resin composition layer after drying was 25 microns.

（4）A040：甲氧基丙二醇[400]丙烯酸酯

（n=9） （5）BCIM：2,2'-雙(2-氯苯基)-4,4'-5,5'-四苯基雙咪唑（奧德里奇化學（Aldrich Chemical）） [ 比較實例 2 ： 製備感光樹脂組成物及乾膜光阻 ] A photosensitive laminate (dry film photoresist) is prepared by laminating a protective film (polyethylene) on the dried photosensitive resin composition layer. [Table 1] Component Product name (or component name) Content (wt%) Example 1 Example 2 Example 3 Comparative example 1 Alkaline developable adhesive resin Preparation example 1 55 55 55 55 Photopolymerizable compound M-2101 14 13 12 14 M-241 3 3 3 3 T063 2 3 3 A040 1 1 2 3 Photoinitiator 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 Colorless crystal violet (Japan Hodogaya Co.) 0.5 0.5 0.5 0.5 Diamond Green GH (Hodogaya Corporation, Japan) 0.3C 0.3C 0.3C 0.3C Solvent MEK (Methyl ethyl ketone, boiling point is about 80℃) 15 15 15 18 Methanol (boiling point is about 64.7°C) 2 2 2 2 Propylene glycol monomethyl ether acetate (PGMEA, boiling point is about 146.4℃) 3 3 3 (1) M2101: Bisphenol A (EO) ₁₀ Dimethacrylate (Miwon Specialty Chemical) (2) M241: Bisphenol A (Ethoxylate) _{4 Dimethacrylate (Miwon Specialty Chemical)} Chemistry) (3) T063: Trimethylolpropane [EO] ₆ triacrylate

(4) A040: Methoxypropylene glycol [400] acrylate

(N=9) (5) BCIM: 2,2'-bis(2-chlorophenyl)-4,4'-5,5'-tetraphenylbisimidazole (Aldrich Chemical) [ Comparative Example 2 : Preparation of photosensitive resin composition and dry film photoresist ]

Based on [0088] and [0093] of Patent Document 1, experiments were conducted to replicate 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 the cited invention 1, the following components based on 300 parts by weight of the "alkaline developable binder resin" obtained in Preparation Example 1 were mixed for about 1 hour using a mechanical stirrer to prepare 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 (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 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) ) [Weight ratio of low boiling point solvent with boiling point of 100℃ or lower than 100℃: weight ratio of high boiling point solvent with boiling point of 115℃ or higher than 115℃ = 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. A hot air oven was used to dry the coated photosensitive resin composition layer, where the drying temperature was 80° C., the drying time was 5 minutes, and the thickness of the photosensitive resin layer after drying was 25 microns. ＜ Experimental example ＞

The physical properties of the dry film photoresists prepared in the Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 3. 1. Measure the exposure ( unit : millijoules / cm² )

The dry film photoresist prepared in one of the example and the comparative example was laminated on a brush-polished copper-clad laminate with a thickness of 1.6 mm. In this article, HAKUTO MACH 610i is used for lamination, in which the substrate preheating roll temperature is 120°C, the laminator roll temperature is 115°C, the roll pressure is 4.0 kgf/cm² and the roll speed is 2.0 minutes/meter.

Using the 41-step flat panel manufactured by Stover graphic technology equipment and the FDi-3 manufactured by ORC, the dry film photoresist laminated on the copper-clad laminate was irradiated with ultraviolet light with a wavelength of 405 nm at an exposure amount. The remaining number of steps was made 15 steps, and then it was 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 method. At this time, the number of remaining steps determined by the measurement becomes the amount of energy at 15 steps. 2. Measurement 1:1 resolution ( unit : micron )

The dry film photoresist prepared in one of the example and the comparative example was laminated on a brush-polished copper-clad laminate with a thickness of 1.6 mm. In this article, HAKUTO MACH 610i is used for lamination, in which the substrate preheating roll temperature is 120°C, the laminator roll temperature is 115°C, the roll pressure is 4.0 kgf/cm² and the roll speed is 2.0 minutes/meter.

The data is formed at 0.5 micron intervals from 4 to 20 microns, so that the distance between the width of the circuit lines and the distance between the circuit lines after development in the laminate becomes 1:1, using the equipment manufactured by Stover Graphics Technology The 41-step flat plate and FDi-3 manufactured by ORC were irradiated with ultraviolet light with a wavelength of 405 nm at an exposure amount so 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 method.

After that, the resolution was determined by measuring the value measured by using the ZEISS AXIOPHOT microscope to make the spacing between the circuit lines and the spacing between the non-circuit lines 1:1. 3. Confirm the bubble ( unit : bubble / mm2 )

Regarding the dry film photoresist prepared in one of the Examples and Comparative Examples, after removing the PET film and the PE film, confirm the diameter existing in the photosensitive resin layer (unit area: 1 mm×1 mm) using a polarizing microscope The number of bubbles less than 1 micron (bubbles/mm2). 4. Confirm the defects after exposure/ development ( unit : defect / mm2)

The dry film photoresist prepared in one of the example and the comparative example was laminated on a brush-polished copper-clad laminate with a thickness of 1.6 mm. In this article, HAKUTO MACH 610i is used for lamination, in which the substrate preheating roll temperature is 120°C, the laminator roll temperature is 115°C, the roll pressure is 4.0 kgf/cm² and the roll speed is 2.0 minutes/meter.

Using a 41-step flat panel manufactured by Stover graphic technology equipment and an FDi-3 manufactured by ORC, the laminate was irradiated with ultraviolet light with a wavelength of 405 nm at an exposure amount, so that the remaining steps were 15 steps, so that the circuit line The distance between the width and the spacing between the circuit lines was 1:1 after development, and then it was 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 method.

For each of the developed dry film photoresists prepared in the Examples and Comparative Examples, 0.5 The number of defects above 3 microns (defects/mm2). A field emission scanning electron microscope (FE-SEM, manufactured by Hitachi, 3000 times magnification) was used to observe the surface and cross section of the photosensitive resin layer obtained in each of the example and the comparative example. [Table 2] category Exposure [mJ/cm2] 1:1 resolution [micron] Bubbles with a diameter of less than 1 micron [bubbles/mm2] Defects after exposure/development [defects/mm2] Example 1 50 7 0 0 Example 2 50 8 0 0 Example 3 50 9 1 0 Comparative example 1 50 12 28 14 Comparative example 2 350 15 17 8

Referring to Table 2 and Figure 1, it is confirmed that there is 1 bubble/mm2 or less than 1 bubble/mm2 with a diameter of less than 1 micron in the photosensitive resin layer of the photosensitive laminate of the example, and there is no diameter of 1 micron to Large bubbles of 5 microns.

In addition, even after the photosensitive resin layer of the example was exposed to ultraviolet rays and developed with an alkaline solution, it was confirmed that there were substantially no defects with a diameter of 0.5 micrometers or more and 3 micrometers or less, or 1 defect per square millimeter or less than 1 It appears in the form of a defect per square millimeter.

It has also been observed that since a small amount of bubbles with a diameter of less than 1 micron are present in the photosensitive resin layer of the example, it is possible to reduce defects in the formation of fine wiring when the photosensitive laminate is used to prepare a circuit board, while achieving high reliability High density and sensitivity, which can form finer wiring.

On the other hand, even when the same energy as that of the example is used in the photosensitive resin laminate of Comparative Example 1, it is difficult to achieve a resolution similar to that of the example. In particular, it was confirmed in the photosensitive resin laminate of Comparative Example 2 that it is difficult to achieve a resolution equivalent to that of the example even when an energy of 350 mJ/cm² is used.

In addition, it was confirmed in the dry film photoresists of Comparative Example 1 and Comparative Example 2 that 15 bubbles/mm2 or more than 15 bubbles/mm2 with a diameter of less than 1 micrometer were generated. Referring to Figure 3, it is confirmed that after the photosensitive resin layer is exposed to light and then developed with an alkaline solution, many defects (8 defects/mm2 or more than 8 defects/mm2) with a diameter of 0.5 microns or more and 3 microns or less appear .

without.

FIG. 1 is a photograph of the surface and cross-section of the photosensitive resin layer of Example 1 confirmed by a field emission scanning electron microscope (FE-SEM, 10,000 times) using a polarizing microscope. 2 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, 12,000 times) using a polarizing microscope. 3 is a photograph used to confirm the defects formed on the photosensitive resin layer of Comparative Example 2 after exposure to ultraviolet rays and development with alkali by a field emission scanning electron microscope (FE-SEM, 3000 times).

Claims (28)

A photosensitive laminate, comprising a supporting substrate; and a photosensitive resin layer, comprising a photopolymerizable compound containing a multifunctional (meth)acrylate compound having three or more functional groups and an alkaline developable binder resin , Wherein, there are 5 bubbles/square millimeter or less than 5 bubbles/square millimeter with a diameter of less than 1 micrometer in the photosensitive resin layer. The photosensitive laminate as described in claim 1, Wherein, the photosensitive resin layer does not contain bubbles with a diameter of 1 μm to 5 μm. The photosensitive laminate as described in claim 1, Wherein in 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, there are 3 bubbles/square millimeter or less than 3 with a diameter of less than 1 micron Bubbles/mm2. The photosensitive laminate as described in claim 1, Wherein the thickness of the support substrate is 1 micron to 100 microns, and The thickness of the photosensitive resin layer is 1 micrometer to 100 micrometers. The photosensitive laminate as described in claim 1, Wherein, after being exposed to ultraviolet rays and developed with alkali, the photosensitive resin layer has 3 defects/square millimeter or less than 3 defects/square millimeter with a cross-sectional diameter of 0.3 micrometer to 4 micrometers. The photosensitive laminate as described in claim 1, The polyfunctional (meth)acrylate compound having three or more functional groups therein has three or more C1 to C10 alkylene oxide groups and three or more (meth)acrylic acids The structure where the ester functional group is bonded to the C1 to C20 central group. The photosensitive laminate according to claim 1, wherein the polyfunctional (meth)acrylate compound having three or more functional groups includes the compound of the following Chemical Formula 1: [Chemical Formula 1]

In Chemical Formula 1, R ₄ is hydrogen or a C1 to C10 alkyl group, R ₅ is a C1 to C10 alkylene group, R ₆ is a p-valent functional group containing a C1 to C20 central group, n2 is an integer from 1 to 20, And p is _{the number of functional groups substituted for R 6} and is an integer of 3-10. The photosensitive laminate as described in claim 1, The photopolymerizable compound further contains a monofunctional (meth)acrylate compound or a bifunctional (meth)acrylate compound. The photosensitive laminate according to claim 8, The monofunctional (meth)acrylate compound includes (meth)acrylates containing C1 to C10 alkylene oxide groups. The photosensitive laminate according to claim 8, Wherein the photopolymerizable compound contains the monofunctional (meth)acrylate compound and the polyfunctional (meth)acrylate compound having three or more functional groups, and the monofunctional (meth)acrylate compound Acrylate compounds include (meth)acrylates containing C1 to C10 alkylene oxide groups, and the polyfunctional (meth)acrylate compounds having three or more functional groups have three or more of them A structure in which C1 to C10 alkylene oxide groups and three or more (meth)acrylate functional groups are bonded to the C1 to C20 central group. The photosensitive laminate according to claim 8, Wherein, based on 100 parts by weight of the monofunctional (meth)acrylate compound, the photopolymerizable compound contains 110 parts by weight or more and 500 parts by weight or less of the polyfunctional having three or more functional groups (Meth)acrylate compound. The photosensitive laminate according to claim 8, Wherein, based on 100 parts by weight of the polyfunctional (meth)acrylate compound having three or more functional groups, the photopolymerizable compound contains 500 parts by weight or more and 1000 parts by weight or less of the difunctional (Meth)acrylate compound. The photosensitive laminate as described in claim 1, The alkaline developable adhesive resin has a weight average molecular weight ranging from 20,000 g/mol to 300,000 g/mol and a glass transition temperature above 20°C and below 150°C. The photosensitive laminate as described in claim 1, The alkaline developable adhesive resin has an acid value in the range of 100 mg KOH/gram to 300 mg KOH/gram. A method for preparing a circuit board using the photosensitive laminate as described in claim 1. A method for preparing the photosensitive laminate according to claim 1, comprising the following steps: A resin composition containing a mixed solvent, the 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; containing three or more A photopolymerizable compound of a functional group multifunctional (meth)acrylate compound; an alkaline developable binder resin; and a photoinitiator is coated on a supporting substrate, followed by drying, The mixed solvent includes the high boiling point solvent having a boiling point of 115°C or higher and the low boiling point solvent having a boiling point of 100°C or lower in a weight ratio of 1:2 to 1:18. The method described in claim 16, The mixed solvent includes the high boiling point solvent having a boiling point of 115°C or higher and the low boiling point solvent having a boiling point of 100°C or lower in a weight ratio of 1:3 to 1:15. The method described in claim 16, The high boiling point solvent with a boiling point of 115°C or higher includes at least one organic solvent selected from the group consisting of butanol, dimethylformamide, and N-methyl-2-pyrrolidine Ketone, gamma butyrolactone, butyl carbitol, butyl cellosolve, methyl cellosolve, butyl acetate, diethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, two Propylene glycol dimethyl ether, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, propylene glycol methyl ether propionate, dipropylene glycol dimethyl ether, cyclohexanone, and propylene glycol monomethyl ether acetate. The method described in claim 16, The low boiling point 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 described in claim 16, The polyfunctional (meth)acrylate compound having three or more functional groups therein has three or more C1 to C10 alkylene oxide groups and three or more (meth)acrylic acids The structure where the ester functional group is bonded to the C1 to C20 central group. The method according to claim 16, wherein the polyfunctional (meth)acrylate compound having three or more functional groups includes the compound of the following Chemical Formula 2: [Chemical Formula 2]

In Chemical Formula 2, R ₄ is hydrogen or a C1 to C10 alkyl group, R ₅ is a C1 to C10 alkylene group, R ₆ is a p-valent functional group containing a C1 to C20 central group, n2 is an integer from 1 to 20, And p is _{the number of functional groups substituted for R 6} and is an integer of 3-10. The method described in claim 16, The photopolymerizable compound further contains a monofunctional (meth)acrylate compound or a bifunctional (meth)acrylate compound. The method described in claim 22, The monofunctional (meth)acrylate compound includes (meth)acrylates containing C1 to C10 alkylene oxide groups. The method described in claim 22, Wherein the photopolymerizable compound contains the monofunctional (meth)acrylate compound and the polyfunctional (meth)acrylate compound having three or more functional groups, and the monofunctional (meth)acrylate compound Acrylate compounds include (meth)acrylates containing C1 to C10 alkylene oxide groups, and the polyfunctional (meth)acrylate compounds having three or more functional groups have three or more of them A structure in which C1 to C10 alkylene oxide groups and three or more (meth)acrylate functional groups are bonded to the C1 to C20 central group. The method described in claim 22, Wherein, based on 100 parts by weight of the monofunctional (meth)acrylate compound, the photopolymerizable compound contains 110 parts by weight or more and 500 parts by weight or less of the polyfunctional having three or more functional groups (Meth)acrylate compound. The method described in claim 22, Wherein, based on 100 parts by weight of the polyfunctional (meth)acrylate compound having three or more functional groups, the photopolymerizable compound contains 500 parts by weight or more and 1000 parts by weight or less of the difunctional (Meth)acrylate compound. The method described in claim 16, The alkaline developable adhesive resin has a weight average molecular weight ranging from 20,000 g/mol to 300,000 g/mol and a glass transition temperature above 20°C and below 150°C. The method described in claim 16, The alkaline developable adhesive resin has an acid value in the range of 100 mg KOH/gram to 300 mg KOH/gram.

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