WO2017119706A1 - Method of manufacturing circuit board - Google Patents

Abstract

The present specification relates to a method of manufacturing a circuit board. In particular, the present specification relates to a method of manufacturing a circuit board and an electronic device including same.

Description

Manufacturing Method of Circuit Board

This specification describes the Korean Patent Application No. 10-2016-0000482 filed with the Korea Intellectual Property Office on January 4, 2016 and the Korean Patent Application No. 10-2017-0000724 filed with the Korea Patent Office on January 3, 2017. Claiming benefit, the entire contents of which are incorporated herein by reference.

The present specification relates to a method of manufacturing a circuit board. Specifically, the present disclosure relates to a circuit board and a method of manufacturing an electronic device including the same.

In recent years, transparent electrodes are required to be formed in effective screen portions in electronic devices such as displays and organic light emitting devices. To this end, a transparent conductive film formed of a material such as ITO, ZnO, or the like is used as an electrode, but these have a problem of low conductivity. In order to improve this, an attempt has been made to form an auxiliary electrode made of an auxiliary electrode pattern on a transparent conductive film electrode for the purpose of improving conductivity.

The present specification is to provide a method for manufacturing a circuit board. Specifically, the present specification is to provide a circuit board and a method of manufacturing an electronic device including the same.

Herein is a step of forming an auxiliary electrode pattern having a thickness of 1㎛ or more on the transparent substrate; Forming a UV curable resin layer by applying a UV curable resin composition on the transparent substrate provided with the auxiliary electrode pattern; Stacking a release film on the UV curable resin layer; Pressing the surface of the release film; An exposure step of irradiating light from an opposite side of a surface of the transparent substrate on which an auxiliary electrode pattern is formed; And developing an uncured portion of the UV curable resin layer after exposure to form a UV curable resin pattern, and before or after the exposing step, further comprising removing the release film. Provided is a method of manufacturing a circuit board.

The method according to an exemplary embodiment of the present specification has an advantage of forming a transparent electrode without a crack on a thick auxiliary electrode.

The method according to an exemplary embodiment of the present specification has an advantage of forming a transparent and low resistance electrode.

1 illustrates a problem of the prior art.

2 shows an electrode pattern manufactured by the method according to the present specification.

3 shows a procedure of a method according to a first exemplary embodiment of the present specification.

4 shows a procedure of a method according to a second exemplary embodiment of the present specification.

FIG. 5 is a scanning electron microscope (SEM) image of the auxiliary electrode pattern of Example 1. FIG.

FIG. 6 is an SEM image showing a UV curable resin pattern and an exposed auxiliary electrode pattern of Example 2. FIG.

7 is an SEM image showing the surface on which ITO of Example 2 is deposited.

8 is a SEM image showing the surface on which ITO of Comparative Example 1 is deposited.

FIG. 9 is an SEM image showing the UV curable resin patterns and the exposed auxiliary electrode patterns of Examples 1 to 3. FIG.

10 is a SEM image showing the UV-curable resin pattern and the exposed auxiliary electrode pattern of Comparative Examples 2 to 4.

Hereinafter, the present specification will be described in detail.

Herein is a step of forming an auxiliary electrode pattern having a thickness of 1㎛ or more on the transparent substrate; Forming a UV curable resin layer by applying a UV curable resin composition on the transparent substrate provided with the auxiliary electrode pattern; An exposure step of irradiating light from an opposite side of a surface of the transparent substrate on which an auxiliary electrode pattern is formed; And developing an uncured portion of the UV curable resin layer after exposure to form a UV curable resin pattern.

The method of manufacturing the circuit board includes forming an auxiliary electrode pattern having a thickness of 1 μm or more on a transparent substrate.

The transparent substrate may be a rigid substrate or a flexible substrate. Specifically, the transparent substrate is preferably a flexible substrate, the flexible substrate may be a plastic substrate or a plastic film. The plastic substrate or the plastic film is not particularly limited, but for example, polyacrylate, polypropylene (PP, polypropylene), polyethylene terephthalate (PET), polyethylene ether phthalate, Polyethylene phthalate, polybutylene phthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene (PS, polystyrene), polyether imide, poly It may include any one or more of polyether sulfone (polyether sulfone), polydimethyl siloxane (PDMS; polydimethyl siloxane), polyether ether ketone (PEEK; Polyetheretherketone) and polyimide (PI).

The substrate may be a substrate having a high transparency, the light transmittance of the substrate may be 50% or more.

A method of forming an auxiliary electrode pattern on the transparent substrate is not particularly limited, and for example, roll printing, inkjet printing, screen printing, deposition, photolithography, etching, or the like may be used.

The auxiliary electrode pattern may be regular or irregular. For example, it may be a stripe, a rhombus, a square lattice, a circle, a wave pattern, a grid, a two-dimensional grid, and the like, but is not limited to a specific form. If the auxiliary electrode pattern is to be designed so that light from a certain light source does not impair optical properties by diffraction and interference, a pattern that minimizes the regularity of the pattern may be used. For this purpose, a wavy pattern and a sine wave may be used. And a pattern in which the spacing of the lattice structure and the thickness of the line are irregularly configured. If necessary, the auxiliary electrode pattern may be a combination of two or more patterns. The auxiliary electrode pattern may include a boundary line of the figures forming the Voronoi diagram or a boundary line forming the Delaunay triangle. The line constituting the auxiliary electrode pattern may be a straight line, but various modifications such as curved lines, wavy lines, and zigzag lines are possible.

The auxiliary electrode pattern may have a thickness of 1 μm or more, specifically 1 μm or more and 10 μm or less, and more specifically 1 μm or more and 3 μm or less.

The line width of the auxiliary electrode pattern may be 3 μm or more and 100 μm or less, and specifically, 5 μm or more and 50 μm or less.

The method of manufacturing the circuit board includes forming a UV curable resin layer by applying a UV curable resin composition on a transparent substrate having the auxiliary electrode pattern.

In the present specification, the UV curable resin refers to a photosensitive material in which a chemical change of a resist layer material occurs in an exposed area during exposure, and a material not exposed to light falls during development.

The UV curable resin composition is not particularly limited as long as it includes a resin cured by ultraviolet rays, but the UV curable resin composition may be a negative photoresist composition. Specifically, the negative photoresist composition may mean a composition including a polymer that is resistant to a developer by exposure to light, and the negative photoresist composition may include a polymer that is exposed to light and thus develops resistance to a developer. have.

The UV curable resin composition may further include at least one of a photoinitiator, a crosslinking agent, an additive, and a solvent.

The polymer, photoinitiator, crosslinking agent, additives and solvents are not particularly limited, and materials generally used in the art may be employed.

The method for applying the UV curable resin composition is not particularly limited, and for example, bar coating, slot die coating, spin coating, comma coating, and microgravure It may be a coating or a dip coating.

The forming of the UV curable resin layer may include applying a UV curable resin composition on a transparent substrate having the auxiliary electrode pattern and drying the applied UV curable resin composition.

The drying method is not particularly limited, but may be a hot air drying method or an infrared drying method.

The method of manufacturing a circuit board may include: stacking a release film on the UV curable resin layer after forming the UV curable resin layer; And pressing the surface of the release film.

The release film is not particularly limited as long as the release film is laminated on the UV curable resin layer and can be removed without damaging the UV curable resin layer. For example, the release film may include at least one of a silicone release film and a fluorine release film.

The method of compressing the surface of the release film is not particularly limited, but the surface of the release film may be compressed using a pressing plate, a thermocompression plate, a compression roll, or a thermocompression roll. In this case, the pressing time and the pressing force may be selected by changing the material and the thickness of the release film and the material of the UV curable resin layer.

The manufacturing method of the circuit board may further include removing the release film before or after the exposure step. Specifically, the release film may be removed before the exposure step or after the exposure step.

The method of removing the release film is not particularly limited, but the release film may be removed by an adhesive roll.

The manufacturing method of the circuit board includes an exposure step of irradiating light from the side of the transparent substrate opposite the surface on which the auxiliary electrode pattern is formed.

The exposure conditions of the exposure step may be adjusted according to the properties of the applied photoresist, it is not particularly limited. If the UV-curable resin layer is not sufficiently exposed, the UV-curable resin layer may not be sufficiently cured, and the surface of the UV-curable resin layer may be damaged during the development process, and a gap may occur between the auxiliary electrode pattern and the UV-curable resin layer. have. On the other hand, when the UV-curable resin layer is excessively exposed, a problem may occur in which all or part of the UV-curable resin layer formed on the auxiliary electrode is exposed so that all or part of the upper part of the auxiliary electrode is not exposed after development.

The manufacturing method of the circuit board may include forming a UV curable resin pattern by developing a portion of the UV curable resin layer not exposed to light after exposure.

After the exposure, the portion of the UV-curable resin layer not irradiated with light is a portion located on the auxiliary electrode pattern among the UV-curable resin layers, and a portion of the UV-curable resin layer positioned on the auxiliary electrode pattern is formed by the auxiliary electrode pattern. The light is blocked and does not receive the emitted light.

By developing the portion of the UV-curable resin layer not irradiated with light after the exposure, the UV-curable resin on the auxiliary electrode pattern may be developed by a developer to expose the auxiliary electrode pattern.

After the exposure, the portion of the UV-curable resin layer to which light is irradiated is a portion in which the auxiliary electrode pattern is not formed and receives the light irradiated from the side opposite to the surface on which the auxiliary electrode pattern is formed, and specifically, the exposure After the light irradiated portion of the UV curable resin layer is a part of the UV curable resin layer formed between the auxiliary electrode pattern. The UV curable resin pattern formed by developing a portion of the UV curable resin layer to which light is not irradiated after the exposure may be formed between the auxiliary electrode patterns.

The difference between the thickness of the auxiliary electrode pattern and the thickness of the UV curable resin pattern may be 200 nm or less. Specifically, the difference between the thickness of the auxiliary electrode pattern and the thickness of the UV curable resin pattern may be 0 nm or more and 200 nm or less, and 50 nm or more and 150 nm or less. In this case, there is an advantage in that the transparent electrode layer formed on the transparent substrate provided with the auxiliary electrode pattern and the UV curable resin pattern does not occur due to the step difference.

The method of developing a portion of the UV-curable resin layer that is not irradiated with light is not particularly limited. For example, the developer is applied or sprayed onto the exposed UV-curable resin layer, or the exposed UV-curable resin layer is immersed in the developer. can do.

The method of manufacturing the circuit board may further include forming a transparent electrode layer on the transparent substrate provided with the auxiliary electrode pattern and the UV curable resin pattern after the forming of the UV curable resin pattern.

The method of forming the transparent electrode layer is not particularly limited, but a transparent electrode material may be deposited on the transparent substrate provided with the auxiliary electrode pattern and the UV curable resin pattern.

The transparent electrode layer may be a transparent metal oxide layer or a thin metal layer having a light transmissive thickness.

The transparent electrode layer may be formed of a metal oxide layer such as indium tin oxide (ITO), ZnO, or indium zinc oxide (IZO), or may be formed of a thin metal such as Al or Cu.

The method of manufacturing the circuit board may further include sequentially forming an organic material layer and an additional electrode layer on the electrode layer.

When the auxiliary electrode and the electrode layer correspond to the electrode layer of the electronic device, an additional layer suitable for the type of the electronic device may be further formed. For example, an organic material layer and an additional electrode layer suitable for the type of electronic device may be further formed on the electrode layer.

The electronic device includes a touch panel, a solar cell, an organic light emitting device, an illumination, a liquid crystal display, and the like.

BACKGROUND OF THE INVENTION In electronic devices, transparent electrodes are increasingly used for transparency, and in order to provide transparency to the electrodes, metal oxides or thin metal layers must be deposited. In the case of metal oxides, the resistance is high, and even if the conductive metal is thin enough to ensure transparency, the resistance is high.

Accordingly, an auxiliary electrode pattern may be provided to lower the resistance of the transparent electrode.

Increasing the application of electronic devices, such as increasing the size of the electronic device or giving flexibility, the need to lower the resistance of the auxiliary electrode is increasing. Although a method of increasing the thickness of the auxiliary electrode pattern may be considered as a method of lowering the resistance of the auxiliary electrode pattern, in this case, as shown in FIG. 1, cracks are formed in the electrode layer deposited due to the difference between the auxiliary electrode pattern and the substrate. Electrical shorts or short circuits can occur.

In order to solve such a problem, as shown in FIG. 2, a planarization layer which can reduce the step difference between the auxiliary electrode pattern and the substrate may be formed.

Hereinafter, the present specification will be described in more detail with reference to Examples. However, the following examples are merely to illustrate the present specification, but not to limit the present specification.

EXAMPLE

[Production example]

Preparation of UV Curable Resin Composition

A weight average molecular weight of 10,100 g / mol, an acid value of 77 mgKOH / g, an acrylic reactor having a ratio of 30 mol% of acrylic resin 16 g, dipentaerythritol hexaacrylate 7.5 g, oxime photoinitiator 1 g, Glide-410 surfactant 0.5 g After dissolving in 75 g of Propylene Glycol Mnomethyl Ether Acetate (PGMEA), and filtered through a filter of 0.1 ㎛ size to prepare a UV curable resin composition.

Example 1

After forming a resist ink pattern having a line width of 15 μm on a polyethylene terephthalate (PET) film in which copper is deposited to a thickness of 2 μm through a reverse offset printing process, a copper auxiliary electrode having a thickness of 2 μm and a line width of 8 μm through a copper etching process Formed a pattern.

After applying the UV curable resin composition prepared in Preparation Example on the substrate with a copper auxiliary electrode having a thickness of 2㎛, line width 8㎛ by using a spin coating method and hot-air dried at 80 ℃ 3 minutes UV curable resin composition Formed a layer.

After laminating the fluorine-based release film on the UV-curable resin composition layer, it was crimped with a press roll under 25 Kgf / cm ² pressure conditions.

After irradiating the exposure amount of 100mJ / cm ² from the back surface of the substrate provided with the copper auxiliary electrode pattern and the UV curable resin composition layer, the release film was removed through an adhesive roll. The substrate from which the release film was removed was further hot-air dried at 120 ° C. for 3 minutes.

It developed for 2 minutes in KOH 0.05 wt% developing solution, and removed the UV curable resin composition layer with which the copper auxiliary electrode pattern upper part was provided.

ITO having a thickness of 100 nm was deposited on the exposed copper auxiliary electrode pattern.

Example 2

It manufactured like Example 1 except having changed the exposure amount into 150mJ / cm <^2> .

Example 3

It manufactured like Example 1 except having changed exposure amount into 200mJ / cm <^2> .

Comparative Example 1

In Example 1, 100 nm-thick ITO was deposited directly on the PET film provided with the copper auxiliary electrode pattern of 2 micrometers in thickness, and 8 micrometers in width, without forming a UV curable resin composition layer.

Comparative Example 2

After forming a resist ink pattern having a line width of 15 μm on a polyethylene terephthalate (PET) film in which copper is deposited to a thickness of 2 μm through a reverse offset printing process, a copper auxiliary electrode having a thickness of 2 μm and a line width of 8 μm through a copper etching process Formed a pattern.

After coating the UV curable resin composition prepared in Preparation Example on the substrate with the copper auxiliary electrode having a thickness of 2 μm and a line width of 8 μm by using a spin coating method, it was dried by hot air at 120 ° C. for 3 minutes to form a UV curable resin composition layer. Formed.

After irradiating 100mJ / cm ² exposure amount from the back surface of the base material provided with the said copper auxiliary electrode pattern and a UV curable resin composition layer, it developed in KOH 0.05wt% developing solution for 2 minutes, and the UV curable resin provided on the upper part of a copper auxiliary electrode pattern. The composition layer was removed.

ITO having a thickness of 100 nm was deposited on the exposed copper auxiliary electrode pattern.

Comparative Example 3

It manufactured like the comparative example 2 except having changed the exposure amount into 150mJ / cm <^2> .

[Comparative Example 4]

It manufactured like the comparative example 2 except having changed the exposure amount into 200mJ / cm <^2> .

Experimental Example 1

Scanning electron microscope (SEM) measurement

A scanning electron microscope (SEM) image of the auxiliary electrode pattern provided on the PET film is shown in FIG. 5.

An SEM image showing the UV curable resin pattern and the exposed auxiliary electrode pattern of Example 1 is shown in FIG. 6.

SEM images showing the surfaces on which ITOs of Examples 1 to 3 and Comparative Examples 1 to 4 were deposited are shown in FIGS. 7 to 10, respectively.

Comparing FIG. 7 (Example 2) and FIG. 8 (Comparative Example 1), when the UV curable resin composition layer is provided, it can be seen that ITO cracks do not occur at the boundary of the auxiliary electrode.

9 (Examples 1 to 3) and FIG. 10 (Comparative Examples 2 to 4), the resin composition layer is formed on the auxiliary electrode when the back exposure is performed in the state of laminating the release film as in Examples 1 to 3. It can be seen that it does not remain, and Comparative Examples 2 to 4 show that a residual resin composition layer exists as shown in FIG. 10.

Experimental Example 2

resistance measurement

After depositing 100 nm of ITO on the auxiliary electrode patterns of Examples 1 to 3 and Comparative Examples 1 to 4, the sheet resistance of the auxiliary electrode substrate was measured using a Mitsubishi Chemical Corporation MCP-T600 sheet resistance meter.

	ITO crack occurs at the auxiliary electrode pattern boundary	Sheet resistance after ITO 100nm deposition (Ω / □)
Example 1	Not Occurred	1.2
Example 2	Not Occurred	1.3
Example 3	Not Occurred	1.2
Comparative Example 1	Occur	1.4
Comparative Example 2	Not Occurred	4.6
Comparative Example 3	Not Occurred	12.3
Comparative Example 4	Not Occurred	16.8

Through Table 1, it can be seen that Comparative Examples 2 to 4 in which the resin composition remained on the auxiliary electrode had high sheet resistance. It can be seen that the remaining resin composition interferes with the effect of reducing the sheet resistance of ITO of the auxiliary electrode.

Claims (4)

1. Forming an auxiliary electrode pattern having a thickness of 1 μm or more on the transparent substrate;

   Forming a UV curable resin layer by applying a UV curable resin composition on the transparent substrate provided with the auxiliary electrode pattern;

   Stacking a release film on the UV curable resin layer;

   Pressing the surface of the release film;

   An exposure step of irradiating light from an opposite side of a surface of the transparent substrate on which an auxiliary electrode pattern is formed; And

   And developing a portion of the UV-curable resin layer after exposure that is not irradiated with light to form a UV-curable resin pattern.

   Before or after the exposing step, further comprising the step of removing the release film.
2. The method of claim 1, further comprising, after the forming of the UV curable resin pattern, forming an electrode layer on the transparent substrate provided with the auxiliary electrode pattern and the UV curable resin pattern.
3. The method of claim 2, further comprising sequentially forming an organic material layer and an additional electrode layer on the electrode layer.
4. The method of claim 1, wherein a difference between the thickness of the auxiliary electrode pattern and the thickness of the UV curable resin pattern is 200 nm or less.

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