KR100999882B1 - Method of fabricating fine pattern on substrate using liquid film barrier - Google Patents

Abstract

PURPOSE: A method for forming fine pattern on a substrate using a liquid film barrier is provided to avoid ink residue by forming a liquid film barrier in a fine gap between a mask and substrate. CONSTITUTION: A method for forming fine pattern on a substrate using a liquid film barrier comprises a barrier formation step(S300) for forming a liquid film barrier by enabling filling solution from smearing between a substrate and a mask and evaporating the filling solution; an ink spray step(S400) for an opening; a curing step(S500); and a mask removal step(S600).

Description

Method of forming fine pattern on substrate using liquid film barrier {METHOD OF FABRICATING FINE PATTERN ON SUBSTRATE USING LIQUID FILM BARRIER}

The present invention relates to a method of forming a micropattern on a substrate using a liquid film barrier, and more particularly, to forming a micropattern on a substrate by applying a functional ink through an opening of a mask. It relates to a fine pattern forming method characterized in that the liquid film barrier is formed to prevent the penetration of the functional ink.

Since the late 20th century, the demand for a pattern method that covers a wide range of small-volume and custom-made products has been raised, and industrially applied the printing technology that has been used in the medium and large graphic arts industry as a method to replace the conventional photolithography. Attempts are being made.

Printing technologies in use today include embossing such as flexography, intaglio printing such as gravure printing, lithography, screen printing, inkjet printing, etc. Other techniques, except inkjet printing, transfer and form patterns by direct contact with pattern molds formed on screen or roll making. On the other hand, inkjet printing can be flexibly responded to model changes by directly printing in a non-contact manner using data patterned virtual pattern images without using a manufactured pattern mold. There is an advantage to getting a pattern. This printing technology has high use efficiency of materials and low equipment investment cost compared to the existing photolithography, and is actively being applied to display and electronic circuit pattern industries.

By using such a printing technique, a functional ink such as a conductor, an organic or inorganic semiconductor, or an organic or inorganic light emitting material is coated and cured to form an electrode, a semiconductor, a dielectric, or an organic or inorganic light emitting pattern.

As an example of a fine pattern through printing technology, in the electrode wiring pattern method, it is important to achieve a high aspect ratio (thickness / wiring width) of the electrode wiring in order to achieve a low resistance value. In the case of screen printing, the thickness of the pattern can be easily adjusted using the thickness of the screen, but there is a problem in that incomplete transfer of ink occurs when the thickness of the screen is too thick compared to the width of the opening of the screen. In addition, there is a problem that the resolution of the pattern is hindered by the ink spread through the micro-gap between the lower screen and the substrate.

Gravure or gravure offset is difficult to achieve a pattern of high aspect ratio compared to the screen, in particular gravure offset has a problem that the pattern line width is variable because the blanket absorbs the solvent of the ink.

In inkjet printing, the thickness of the electrode wiring is controlled by the contact angle of the ink on the substrate. When the contact angle is low, the droplets are spread and the thickness of the electrode wiring is not only lowered, but the line width of the electrode wiring is also widened. Even if a hydrophobic coating is applied to the substrate surface, the contact angle is limited, so that it is difficult to realize a sufficient electrode thickness, and when the substrate surface is all hydrophobic, ink droplets are agglomerated with each other, making it difficult to form a continuous electrode. .

In the case of a fine pattern of a semiconductor, a dielectric, or an organic or inorganic light emitting material that does not generally require a thick film other than the electrode wiring, there is a problem that the ink invades the areas other than the region to be patterned when using a printing technique.

In order to solve this problem, a conventional technique is to form a hydrophilic region by coating a hydrophobic film on the surface of the substrate and patterning the hydrophobic film using laser direct irradiation or photolithography, and printing the ink on the hydrophilic region to form a fine pattern. A method of carrying out was devised. However, the surface energy pattern method for patterning hydrophobic and hydrophilic regions on a substrate requires additional methods such as expensive photolithography.

A mask patterning technique has been proposed. 1 is a schematic diagram illustrating a mask patterning process. Referring to FIG. 1, a patterned opening 21 is formed, and the mask 20 is placed on the substrate 10, and then the ink 30 is applied to the pattern so that the ink 30 penetrates into the opening 21. In addition, the fine pattern 31 may be formed by drying the ink 30 by means of heat, ultraviolet rays, microwaves or electrons, and then removing the mask 20. If a thick film fine pattern is required, the thick film fine pattern may be formed by applying more ink to the opening 21 through the thickness of the mask.

However, according to the mask patterning method, as shown in FIG. 2, the minute gap 40 exists between the substrate 10 and the mask 20. As a result, the ink 30 penetrates into the microcavity 40 due to capillary force, so that the ink remains in portions other than the pattern position of the mask even after the ink 30 is dried and the mask 20 is removed.

When using the mask patterning method to avoid the additional process for patterning these hydrophobic and hydrophilic regions, as noted above, the presence of micro-gaps 40 between the substrate 10 and the mask 20 results in the presence of conductors and semiconductors. , A dielectric, or an organic or inorganic light emitting material penetrates into the microcavity 40 by capillary force, thereby preventing a micropattern.

The present invention is to solve the above-mentioned problems and when the functional ink is applied to the opening of the mask formed to form a pattern by forming a liquid film barrier that can prevent the penetration of the functional ink in the micro-gap between the substrate and the mask opening It is an object of the present invention to provide a method for forming a fine pattern so that ink residue does not remain in other portions. In addition, since there is no need for excessive additional processes or additional costs, the purpose of the present invention is to achieve simplicity and cost reduction of the micropattern process through a printing technique using a liquid film barrier.

In order to achieve the above object, the method of forming a micropattern on a substrate using the liquid film barrier of the present invention includes an alignment step of placing a mask having an opening forming a pattern on the substrate, a filling step of injecting a filling solution into the opening, A barrier forming step in which the filling solution penetrates into a gap provided between the substrate and the mask to form a liquid film barrier, and the filling solution remaining in the opening is evaporated, and an ink coating step of applying functional ink to the opening; And a curing step for curing the applied functional ink to form a functional pattern, and a mask removing step for removing the mask from the substrate. Alternatively, the mask may be aligned after the barrier solution coating step of coating the filling solution on the substrate before the mask alignment step, and the filling solution remaining in the opening may be evaporated.

The boiling point of the fill solution must be higher than the curing temperature of the functional ink so that the liquid film barrier does not evaporate until the functional ink cures to form a functional pattern, and the uncured functional ink does not penetrate into the microgap between the substrate and the mask. The functional ink and the filling solution are preferably not mixed with each other.

The film thickness of the cured functional pattern can be achieved by applying more ink by adjusting the thickness of the mask in addition to the ink concentration.

According to the present invention, prior to injecting the conductive ink into the opening of the mask, the functional ink applied by forming the liquid film barrier between the substrate and the mask positioned on the substrate is transferred to the opening of the mask and the liquid film barrier. It can be made to stay stable in the space made. This provides a method for forming a micropattern on a substrate using a liquid film barrier that enables the functional ink to form a functional pattern without leakage during curing, and prevents the formation of the functional pattern in an unintended region.

In addition, by using a filling solution whose boiling point is higher than the curing temperature of the functional ink, it is possible to prevent the liquid film barrier from evaporating during the curing of the functional ink by means of heat, ultraviolet rays, microwaves or electrons. There is provided a method of forming a micropattern on a substrate using a liquid film barrier that can maintain a liquid film barrier until curing is completed and prevent penetration of additional functional inks into fine gaps. In addition, the filling solution can be prevented from penetrating the micro-gap due to the diffusion effect of the functional ink by using a solution that is not mixed with the functional ink.

In addition, printing techniques do not require excessive additional processes or additional costs, as in the conventional surface energy pattern method, which had to prepattern hydrophobic and hydrophilic regions on the substrate in order to finely pattern the functional ink locally on the substrate. An object of the present invention is to provide a method for forming a fine pattern on a substrate using a liquid film barrier, which can achieve process simplicity and cost reduction, which are advantages of the fine pattern method.

1 is a schematic diagram showing a fine patterning process using a conventional mask.
2 is a schematic diagram illustrating a problem of a fine patterning process using a conventional mask.
3 is a flowchart illustrating a method of forming a fine pattern on a substrate using a liquid film barrier according to an embodiment of the present invention.
4 is a schematic diagram illustrating a process of forming a fine pattern on a substrate using a liquid film barrier according to the embodiment of FIG. 3.
FIG. 5 is a flowchart illustrating a method of forming a fine pattern on a substrate using a liquid film barrier by applying a filling solution before the mask alignment step of FIG. 3.
6 is a schematic diagram illustrating a process of forming a fine pattern on a substrate using a liquid film barrier according to the embodiment of FIG. 5.

Hereinafter, a method of forming a fine pattern on a substrate using a liquid film barrier according to a first embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a flowchart illustrating a method of forming a micropattern on a substrate using a liquid film barrier according to a first embodiment of the present invention, and FIG. 4 is a process of forming a micropattern on a substrate using a liquid film barrier according to the embodiment of FIG. It is a schematic diagram showing.

3 to 4, in the method of forming a micropattern on a substrate using a liquid film barrier according to the present embodiment, an alignment step of placing a mask 200 having an opening 210 forming a pattern on a substrate 100 ( S100, a filling step (S200) of injecting the filling solution 300 into the opening 210, and the filling solution 300 penetrates into a gap provided between the substrate 100 and the mask 200. A barrier forming step (S300) in which the liquid film barrier 310 is formed and the filling solution 300 remaining in the opening 210 is evaporated, and the opening 210 is a conductor, a semiconductor, a dielectric, or an organic or inorganic material. Ink coating step (S400) for applying a functional ink 400, such as a light emitting material, a curing step (S500) for curing the applied functional ink 400 to form a fine pattern 410, and the substrate ( A mask agent that separates the mask 200 from 100 It characterized in that it comprises a step (S600).

In the alignment step S100, the mask 200 having the opening 210 forming a pattern is positioned on the substrate 100. The mask 200 is aligned to the position where the micro pattern is to be formed on the substrate 100.

In the filling step (S200), the filling solution 300 is injected into the opening 210 of the mask 200. Injection of the filling solution 300 may be by an inkjet method, but is not limited thereto and may be applied by a dispenser. It may also be applied via a squeegee such as screen printing.

The filling solution 300 has a property of not being mixed with the functional ink 400 to be described later, and the solution filled in the microcavity 150 is formed before the application of the functional ink or in the curing step of the functional ink (S500). To avoid evaporation, choose a fill solution whose boiling point is higher than the curing temperature of the functional ink.

In the barrier forming step (S300), a portion of the injected filling solution 300 penetrates into the microcavity 150 between the substrate 100 and the mask 200 to form a liquid film barrier 310 and an opening 210. The remaining part remaining in the area of is evaporated.

Since the mask 200 is placed on the substrate 100 to set a fine pattern, a gap exists between the substrate 100 and the mask 200. When the filling solution 300 is injected through the opening 210 of the mask 200, a part of the filling solution 300 is caused by capillary force generated by the microcavity 150 between the substrate 100 and the mask 200. Penetrates into the microcavity 150 to form the liquid film barrier 310.

The remaining filling solution 300 remains in the region of the opening 210 having a large contact area with air and evaporates. By applying heat in this process, it is possible to promote the evaporation of the filling solution 300 present in the opening 210 region.

The filling solution 300 penetrating into the microcavity 150 between the substrate 100 and the mask 200 forms a liquid film barrier 310, and the filling solution 300 existing in the opening 210 region evaporates. The liquid film barrier 310 forms an accommodating space for accommodating the functional ink 400 together with the opening 210.

In the ink coating step S400, the functional ink 400 is applied through the opening 210 of the mask 200 by an inkjet method. Alternatively, a dispenser can be used or a squeegee can be used as in screen printing. Alternatively, a device such as a bar coater or a wire coater can be used to apply the ink. Alternatively, air or electrostatic spraying tools can be used to apply the ink. Alternatively, a tool in the form of a roller may be used to apply the ink.

The functional ink 400 may be a conductive ink in which fine metal particles such as gold (Au), silver (Ag), or copper (Cu) are dispersed in a solvent. The functional ink 400 may be a semiconductor ink in which an organic semiconductor or an inorganic semiconductor showing semiconductor properties is dissolved or dispersed in a solution in a particulate state. The functional ink 400 may be a dielectric ink in which an organic dielectric or an inorganic dielectric exhibiting the properties of the dielectric is dissolved or dispersed in a solution in a particulate state. The functional ink 400 may be a luminescent ink in which organic or inorganic materials emitting light by electric current or electric fields are dissolved or dispersed in a solution in a particulate state.

Since the liquid film barrier 310 is formed by using the filling solution 300 which is not mixed with the functional ink 400, the functional ink 400 is formed by the minute gap 150 existing between the substrate 100 and the mask 200. Can prevent leakage. Therefore, the applied functional ink 400 is stably positioned in the space consisting of the liquid film barrier 310 and the opening 210.

In the curing step (S500), the applied functional ink 400 is cured to heat to form a fine pattern 410. The curing step (S500) may be performed in two stages, drying the functional ink 400 by applying room temperature or mild heat, and curing the functional ink 400 through heat treatment after drying. The method of curing may be curing using ultraviolet rays, microwaves or electrons in addition to heat treatment. After the curing step S500, the fine pattern 410 is formed along the opening 210 formed in the mask 200.

At this time, it is preferable to set the boiling point of the filling solution 300 higher than the curing temperature of the functional ink 400. In this case, since the filling solution 300 forming the liquid film barrier 310 remains without evaporation until the functional ink 400 is completely cured, the liquid film barrier 310 is lost by evaporation and thus the substrate 100 is removed. ) And an additional penetration of the functional ink 400 into the minute gap 150 between the mask 200 and the mask 200. After the functional ink 400 is completely cured to form the fine pattern 410, the temperature is continuously raised to reach the boiling point of the filling solution 300, thereby filling the filling solution 300 forming the liquid film barrier 310. Can be evaporated. Alternatively, the filling solution 300 may be removed after the mask removing step S600.

In the mask removing step S600, the mask 200 is separated from the substrate 100, leaving only the fine pattern 410 formed through curing. Since the filling solution 300 forming the liquid film barrier 310 may not be completely removed even after additional heating after curing of the functional ink 400 in the curing step S500, the filling solution 300 may be removed. Only the fine pattern 410 may be left on the substrate 100 by washing off or completely evaporating through additional heating.

Hereinafter, a method of forming a fine pattern on a substrate using a liquid film barrier according to a second embodiment of the present invention will be described with reference to the accompanying drawings.

5 is a flowchart illustrating a method of forming a micropattern on a substrate using a liquid film barrier according to a second embodiment of the present invention, and FIG. 6 is a process of forming a micropattern on a substrate using a liquid film barrier according to the embodiment of FIG. 5. It is a schematic diagram showing.

5 to 6, in the method of forming a fine pattern on a substrate using the liquid film barrier according to the present embodiment, a barrier solution applying step (S010) and an opening 210 are applied to the filling solution 300 on the substrate 100. ) Is placed in the alignment step (S100) and the filling solution 300 is penetrated into the gap provided between the substrate 100 and the mask 200 to form a liquid film barrier 310. And a barrier forming step (S300) in which the filling solution 300 remaining in the opening 210 is evaporated, and a functional ink 400 such as a conductor, a semiconductor, a dielectric, or an organic or inorganic light emitting material through the opening 210. ) Ink coating step (S400) for applying a coating, a curing step (S500) for curing the applied functional ink 400 to form a fine pattern 410, and the mask 200 from the substrate 100 To include a mask removing step (S600) for leaving It characterized.

According to the method for forming a micropattern on a substrate using a liquid film barrier according to the present invention, the filling solution 300 is applied prior to applying the functional ink 400 to form the micropattern 410 through the opening 210 provided in the mask 200. Injection) to form a liquid film barrier 310 in the micro-gap 150 existing between the substrate 100 and the mask 200 positioned on the substrate, or to apply the filling solution 300 directly on the substrate After the alignment of the mask 200 to form a liquid film barrier 310 in the micro-gap 150 existing between the substrate 100 and the mask 200, the applied functional ink 400 is the micro-gap 150 It may be to stably stay in the space consisting of the opening 210 and the liquid film barrier 310 of the mask 200 without penetrating into.

Therefore, the curing can be performed stably without leaking the functional ink 400, and by adjusting the concentration of the functional ink 400 and the thickness of the mask, a fine pattern 410 having a high aspect ratio is formed in a predetermined pattern region. There is an advantage that can be done.

In addition, by using the filling solution 300 whose boiling point is higher than the curing temperature of the functional ink 400, the liquid film barrier 310 may not evaporate during the curing process of the functional ink 400. Since the liquid film barrier 310 fills the microcavity 150 until the functional ink 400 is completely cured, the micropattern 410 may be formed in a predetermined pattern region without additional penetration into the microcavity 150.

In addition, in order to achieve the above-described effects, the process does not require excessive additional processes or additional costs, thereby achieving process simplicity and cost reduction, which are advantages of the micropattern method through the printing technique.

10 substrate 20 mask
21: opening 30: ink
31: fine pattern 40: fine gap
100: substrate 150: fine gap
200: mask 210: opening
300: filling solution 310: liquid film barrier
400: functional ink 410: fine pattern

Claims (5)

A barrier forming step in which a fill solution penetrates into a gap provided between a substrate and a mask positioned on the substrate to form a liquid film barrier, and the fill solution remaining in the opening formed in the mask to form a pattern evaporates;
An ink application step of applying functional ink to the openings;
A curing step of curing the applied functional ink to form a fine pattern;
And removing a mask from the substrate to remove the mask. The method of forming a micropattern on a substrate using a liquid film barrier. The method of claim 1,
An alignment step of placing the mask on the substrate;
The method of forming a fine pattern on a substrate using a liquid film barrier, characterized in that for performing the filling step of injecting the filling solution into the opening and the barrier forming step. The method of claim 1,
A barrier solution coating step of applying the filling solution onto the substrate;
The method of forming a fine pattern on a substrate using a liquid film barrier, characterized in that to perform the alignment step to position the mask on the substrate on which the barrier liquid is applied. The method of claim 1
The method of forming a fine pattern on a substrate using a liquid film barrier, characterized in that the boiling point of the filling solution is higher than the curing temperature of the functional ink. The method of claim 1,
The method of forming a fine pattern on a substrate using a liquid film barrier, characterized in that the polarity of the filling solution is different from the functional ink is not mixed with each other.

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