KR20110035062A - Method for forming micro-pattern using inkjet printing - Google Patents

Abstract

PURPOSE: A micro-pattern formation method by inkjet printing is provided to surface-treat a substrate and form a micro-pattern on the substrate at the same time. CONSTITUTION: A micro-pattern formation method by inkjet printing comprises the following steps: preparing a washed substrate(S10); forming a patterned hydrophobic thin film on the substrate by inkjet printing hydrophobic ink along to a pre-fixed pattern(S30); and inkjet printing functional ink on the hydrophobic thin film for producing micro patterns(S40).

Description

Fine pattern formation method using inkjet printing {METHOD FOR FORMING MICRO-PATTERN USING INKJET PRINTING}

The present invention relates to a method for forming a fine pattern using inkjet printing, and more particularly, to a method of surface treating a substrate and forming a fine pattern using droplets inkjet printed through a fine nozzle.

With the development of electrical and electronic technologies, miniaturization of electrical and electronic components and equipment is rapidly progressing. In such electrical and electronic equipment, a module having a unique function is manufactured by interconnecting a plurality of devices having different functions, and these functional modules are typically formed by bonding elements to corresponding portions of an electrode pattern formed on a circuit board. .

There are many kinds of methods for forming a fine pattern (for example, an electrode pattern), but an inkjet printing technique is a method that is increasing in recent years.

Inkjet printing technology is a technique of directly forming a pattern by spraying droplets of functional inks onto a substrate through a fine nozzle. Since the inkjet printing technique is an additive process of directly forming a pattern, it is possible to shorten many processes and to significantly reduce the amount of waste liquid generated, as compared with a photolithography process using a mask. In addition, the amount of material consumed can be minimized due to the Drop-on-Demand (DOD) process.

However, in the process of fabricating a circuit using a conventional inkjet printing technology, a surface treatment process for controlling surface energy of a substrate has to be preceded before inkjet printing in order to manufacture a fine pattern. When the surface energy of the substrate is lowered through surface treatment and the surface of the substrate is made hydrophobic, the functional inks sprayed on the substrate do not spread, resulting in a thin line width of the pattern to be produced. Can be.

Surface treatment techniques applied to inkjet printing include chemical surface treatments such as plasma surface treatment and physical surface treatments such as spin coating or dip coating. Plasma surface treatment uses fluorine-based gases such as CF ₄ , CHF ₃ and C ₄ F ₄ to form a hydrophobic fluorinated organic thin film on the surface, and controls the size of hydrophobicity by controlling plasma process conditions. On the other hand, spin coating and dip coating are applied to the surface of the hydrophobic solution thinly to control the surface energy of the substrate, the size of the hydrophobicity is greatly affected by the basic properties of the hydrophobic solution used.

However, the plasma process typically used as the surface treatment process is carried out in a vacuum state, which requires a lot of equipment investment and maintenance costs. In addition, in the case of a plasma process that can be performed at atmospheric pressure, since expensive fluorine-based gas must be continuously supplied, this also has a problem in that facility maintenance costs are high. On the other hand, the physical surface treatment method such as spin coating has a problem that the thickness of the formed film is non-uniform, and the thickness thereof is relatively thick compared to the plasma process.

In addition, although inkjet printing technology is combined with photolithography technology, inkjet printing is used for pattern miniaturization, but the formation of resist layer due to photolithography technology and the increase in the number of processes leading to exposure, development, and etching Not only will it be unavoidable, but such a process cannot be free from economic problems.

Accordingly, the present invention intends to provide a method for directly forming a fine pattern using inkjet printing without the surface treatment process performed on the entire surface of the substrate as described above.

Therefore, the first problem to be solved by the present invention is to provide a method for forming a fine pattern using inkjet printing technology without the surface treatment process of the front surface of the substrate.

The second problem to be solved by the present invention is to provide a method for forming a fine pattern that can simultaneously perform surface treatment and pattern production by using inkjet printing technology.

The third problem to be solved by the present invention is to provide a fine pattern forming method that can shorten the manufacturing process and reduce the process cost compared to the conventional photolithography process.

The present invention to achieve the first object,

Preparing a cleaned substrate;

Forming a patterned hydrophobic thin film by inkjet printing hydrophobic ink along a predetermined pattern on the substrate; And

It provides a fine pattern forming method using inkjet printing comprising the step of forming a fine pattern by inkjet printing a functional ink on the hydrophobic thin film.

Here, the line width of the patterned hydrophobic thin film is preferably equal to or larger than the line width of the fine pattern.

According to another aspect of the present invention,

Preparing the cleaned substrate:

Inkjet printing a hydrophobic ink on a substrate to form a hydrophobic bank used to form a predetermined pattern; And

The present invention provides a method of forming a fine pattern using inkjet printing, the method including forming a fine pattern by inkjet printing functional ink on a region partitioned by the hydrophobic bank.

The forming of the hydrophobic bank may increase the height of the hydrophobic bank by overlaying the hydrophobic ink on a previously formed hydrophobic bank.

In the forming of the fine pattern, the height pattern may be formed by inkjet printing the functional ink between the hydrophobic banks having the increased height.

In addition, the hydrophobic ink may comprise Teflon.

The present invention to achieve the third object,

Preparing a cleaned substrate;

Ink-jet printing photosensitive ink on the substrate to form a photosensitive bank used for forming a predetermined pattern;

Exposing and curing the photosensitive bank formed on the substrate;

Forming a fine pattern by inkjet printing functional ink on a region partitioned by the photosensitive bank; And

It provides a method of forming a fine pattern using inkjet printing comprising the step of removing the photosensitive bank by inkjet printing the etching solution on the photosensitive bank.

In the forming of the photosensitive bank, the height of the photosensitive bank may be increased by overlaying the photosensitive ink on a previously formed photosensitive bank.

In the forming of the fine pattern, the height pattern may be formed by inkjet printing the functional ink between the photosensitive banks having the increased height.

In addition, the photosensitive ink may include a photoresist.

The method may further include heating the substrate after preparing the cleaned substrate, and at least one inkjet printing may be performed while the substrate is heated.

In addition, after the forming of the fine pattern, it may further include a post-treatment step for expressing the characteristics of the functional ink.

In addition, the functional ink may have conductivity.

According to the method of forming a fine pattern using inkjet printing according to the present invention, the surface treatment on the entire surface of the substrate is unnecessary for miniaturization of the pattern formed by the inkjet. That is, since the surface treatment of the substrate and the formation of the fine pattern are performed at the same time with the inkjet printing technology, it is not necessary to introduce additional equipment or system for the surface treatment, and the manufacturing process is shortened by shortening the manufacturing process. It can be greatly reduced.

Hereinafter, the present invention will be described in more detail with reference to preferred examples. However, these examples are intended to illustrate the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited thereby.

In the present invention, by forming inkjet printing on the substrate, a structure restricting the increase in the line width of the fine pattern replaces the conventional surface treatment process for the entire surface of the substrate, and inkjet functional ink on the structure or in the area partitioned by the structure. Print to form a fine pattern. That is, in the method of forming a fine pattern according to the present invention, both the structure and the fine pattern used for forming the fine pattern can be formed by using inkjet printing.

1 and 2 are steps illustrating a method of forming a fine pattern using inkjet printing according to an embodiment of the present invention.

In order to form a fine pattern using inkjet printing on the substrate, first, the substrate 10 on which the predetermined pattern is to be formed is cleaned and prepared (S10). The substrate on which the pattern is to be formed should be cleaned of particles and organic matter remaining on the substrate through dry cleaning or wet cleaning.

Next, as shown in FIG. 2A, the cleaned substrate 10 is heated (S20). The heating step of the substrate is to allow the ink to dry quickly in the inkjet printing process to be described later. If the ink is dried quickly, the shape of the pattern can be made better, and the ink sprayed through inkjet printing can be prevented from spreading widely. Therefore, it is preferable that the substrate is kept heated in the inkjet printing process. Although the heating temperature of the substrate is not particularly limited, it is preferably about 100 degrees, and by heating the substrate at such a temperature, the phenomenon of agglomeration on the substrate is prevented when ink is ejected, and the pattern is dried immediately by inkjet printing. Can be formed.

Subsequently, as shown in FIGS. 2B and 2C, the hydrophobic ink 30 is inkjet printed along a predetermined pattern using the inkjet nozzle 20 to form the patterned hydrophobic thin film 31. (S30). The shape of the pattern is predesigned and stored in a computer, and the hydrophobic ink is printed onto the substrate using the inkjet nozzle 20 of the inkjet printing apparatus according to the pattern.

Hydrophobic ink is made of ink by adjusting the physical properties so that the properties of the remaining film remaining dry and hydrophobic can be used for inkjet printing, wherein the size of the hydrophobicity can be adjusted by changing various combinations of chemical functional groups .

The hydrophobic ink 30 sprayed through inkjet printing is formed of the patterned hydrophobic thin film 31 through a drying process.

The line width w1 of the hydrophobic thin film formed to replace the surface treatment process of the entire surface of the substrate is preferably equal to or larger than the line width of the fine pattern to be formed because the desired fine pattern should be formed by superimposing inkjet printing thereon. . The line width of such a hydrophobic thin film can be adjusted according to the hydrophobic size of the hydrophobic ink. The type of hydrophobic ink used in the present invention is not limited, but preferably includes teflon which is most used.

In addition, the hydrophobic ink used in the present invention has a durability (for example, heat resistance) to the post-treatment process so that the hydrophobic thin film is not deformed in a post-treatment process (for example, heat treatment) to improve the functionality of the functional ink to be described later. It is preferable to have.

Next, as illustrated in FIGS. 2D and 2E, the fine pattern 41 is formed by inkjet printing the functional ink 40 on the hydrophobic thin film 31 (S40). The fine pattern 41 is formed by spraying the functional ink 40 onto the hydrophobic thin film 31 through the inkjet nozzle 20 and drying the sprayed functional ink.

The functional ink may preferably have conductivity, through which the fine pattern according to the present invention may be an electrode pattern used for a circuit board. The conductive ink is an ink that conducts additional post-processing after the ink is dried so that the materials contained in the ink react to obtain conductivity. However, in the present invention, the functional ink is not necessarily limited to the conductive ink, and various functional inks in which the characteristics of the ink are expressed by drying only the ink used without the post-treatment process may be used.

On the other hand, in order to increase the height (or thickness) of the fine pattern formed by using inkjet printing, overlay inkjet printing may be used. That is, the height (or thickness) of the fine pattern formed by overlapping inkjet printing on the formed fine pattern a plurality of times can be increased. In this case, in order to further improve the height increase effect of the pattern, it is preferable to perform overlap printing in a state where heat is applied to the substrate.

Next, a post-treatment step for expressing the characteristics of the functional ink is performed (S50). The post-treatment step is an optional process that takes place depending on the type of functional ink used. For example, the post-treatment step may be applied differently according to the type of ink as described below, and after the post-treatment step, the functional ink may express its characteristics to form a final fine pattern 41a.

The conductive polymer ink prepared by using a conductive polymer such as PEDOT-PSS, Polyaniliane, Polypyrrole, Polythiophene, etc., is conductive in a certain temperature atmosphere, it is preferable that the heat treatment process is performed in a specific temperature atmosphere.

The colloid type ink manufactured by using nano metal particles such as Cu, Ag, Au, and the like is obtained by sintering particles through a sintering process at a predetermined temperature or more after the ink is dried. Through this sintering process, the solvent including the dispersant and the binder is removed, leaving only the solute contained in the ink.

An ink using a precursor of a conductive material such as an organometallic compound may be reduced to metal at a predetermined temperature and atmosphere after the ink is dried, or by applying a reducing liquid containing a catalyst to the pattern. Conductivity is obtained through the reduction process of. In this case, the coating of the reducing liquid may also be performed through an inkjet printing process.

Ink containing a seed material that is changed to a metallic state when reduced, such as palladium, is electrically conductive through the non-plating by applying a solution containing a reducing agent to the pattern after drying. At this time, the coating of the reducing liquid may also be made through an inkjet printing process.

3 and 4 are steps illustrating a fine pattern forming method using inkjet printing according to another embodiment of the present invention.

The step S10 of preparing the cleaned substrate and the step S20 of heating the cleaned substrate as shown in FIG. 4A are substantially the same as those of the above-described embodiment, and thus a detailed description thereof will be omitted.

Next, as shown in FIGS. 4B and 4C, hydrophobic ink 30 is inkjet printed onto the substrate 10 to form a hydrophobic bank 32 used to form a predetermined pattern. (S31). The hydrophobic bank 32 is formed by spraying the hydrophobic ink 30 onto the substrate using the inkjet nozzle 20 and drying it. This hydrophobic bank 32 serves as a bank, such as a bank, that prevents the spread of the functional ink to be subsequently inkjet printed. Such hydrophobic banks should be formed to suit the width of the pattern to be fabricated. Only then, the functional ink filled in the area partitioned into the hydrophobic banks is blocked by the hydrophobic banks so that a specific pattern is formed, thereby forming a fine pattern.

On the other hand, when the hydrophobic bank is formed high in the process of forming the hydrophobic bank, the amount of functional ink filled between the hydrophobic banks can be increased. The height (or thickness) of the fine pattern formed by filling the functional ink in the area partitioned by the hydrophobic bank may be greater than the height of the fine pattern formed by inkjet printing the functional ink on the hydrophobic thin film. When the height of the pattern is increased to improve the aspect ratio of the pattern, the conductive pattern increases the cross-sectional area of the pattern due to the increase in height, thereby reducing the electrical resistance and reducing the RC delay.

Increasing the height of the hydrophobic bank may be achieved by overlay inkjet printing of the hydrophobic ink on the hydrophobic bank.

In addition, the highly formed hydrophobic bank may be formed between the patterns to disconnect between the respective patterns, and may serve to support the patterns from being deformed.

Next, as shown in FIGS. 4 (d) and 4 (e), the fine pattern 41 is formed by inkjet printing the functional ink 40 in a region partitioned by the hydrophobic bank (S41). This process is accomplished by spraying the functional ink 40 between the hydrophobic banks 32 through the inkjet nozzle 20 and then drying the functional ink.

After the functional ink is inkjet printed, a post-treatment step for expressing the characteristics of the ink according to the type of the functional ink as shown in Figure 4 (f) may be further included (S50). Through the post-treatment step, a final fine pattern 41a in which the characteristic is expressed from the functional ink is formed.

5 and 6 are steps illustrating a method for forming a fine pattern using inkjet printing according to another embodiment of the present invention.

Another embodiment of the present invention is the same as the above-described embodiment in that the fine pattern is formed by filling the conductive ink between the regions partitioned by the bank, except that the bank is formed using photosensitive ink rather than hydrophobic ink. There is a difference. Hereinafter, a description will be given focusing on a process different from the above-described embodiment.

6 (b), 6 (c) and 6 (d), the photosensitive bank 34 used to inkjet print the photosensitive ink 33 on the cleaned substrate to form a predetermined pattern. ) Is formed (S32). Here, the only difference is that the ink used is a photosensitive ink rather than a hydrophobic ink, and the process of forming the bank is substantially the same as in the above-described embodiment. The photosensitive bank 34 is formed by spraying and drying the photosensitive ink 33 through the inkjet nozzle 20.

The photosensitive bank formed in place of the surface treatment should be printed to match the line width of the pattern to be produced. However, unlike the hydrophobic bank, since the photosensitive bank does not have hydrophobicity, it is preferable that the photosensitive bank is basically formed high through overlapping printing. This is because the functional ink filled in the area partitioned by the photosensitive bank is blocked by the photosensitive bank so that an increase in width (or line width) does not occur, and thus fine patterns can be produced.

On the other hand, when the photosensitive ink is inkjet printed, it is preferable that the substrate is heated to maintain the heated state in order to dry the ink quickly. In particular, when the photosensitive ink is printed, heating of the substrate is required to increase the height of the photosensitive bank through overlapping printing, and this heating process has an advantage of producing a pre-bake effect of the photosensitive ink.

Next, as shown in FIG. 6 (d), the photosensitive bank formed on the substrate is exposed and cured (S33). Photosensitive resins typically include photoresists, and these photosensitive resins have a property of being cured when exposed to specific light. Therefore, in order to harden the photosensitive bank formed in the board | substrate, the photosensitive bank is exposed to the light of the specific wavelength band suitable for photosensitive resin.

Next, as illustrated in FIGS. 6E and 6F, the fine pattern 41 is formed by inkjet printing the functional ink 40 in a region partitioned by the cured photosensitive bank 35. (S41). This process can be accomplished by spraying the functional ink 40 using the inkjet nozzle 20 and drying it.

Thereafter, a post-treatment step S50 for expressing the characteristics of the ink may be added according to the type of the functional ink, and the post-processed fine pattern 41a may have the intended function by expressing the characteristics of the functional ink. Will be. This post-treatment step may be located after the etching process, which will be described later.

Next, as shown in FIG. 6 (h), the etching solution 50 is inkjet printed on the photosensitive bank 35 to remove the photosensitive bank (S60). That is, after the functional ink is dried to form the fine pattern 41, the etching solution 50 is sprayed on the upper end of the cured photosensitive bank 35 by using the inkjet nozzle 20 to remove the photosensitive bank. In a typical lithography process, a substrate is immersed in an etchant or an etchant is applied, which may cause damage to a functional pattern. Therefore, in order to minimize damage to the functional pattern, and to reduce the amount of toxic etching solution used, the etching solution is sprayed using ink jet printing. By inkjet printing the etching solution in this manner, a fine pattern from which the photosensitive bank is removed can be formed on the substrate.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1 and 2 schematically illustrate a flowchart and a process of a method of forming a fine pattern using inkjet printing according to an embodiment of the present invention.

3 and 4 are schematic views illustrating a flowchart and a process of a method of forming a fine pattern using inkjet printing according to another embodiment of the present invention.

5 and 6 are schematic views illustrating a flowchart and a process of a method of forming a fine pattern using inkjet printing according to another embodiment of the present invention.

Claims (13)

Preparing a cleaned substrate; Forming a patterned hydrophobic thin film by inkjet printing hydrophobic ink along a predetermined pattern on the substrate; And Forming a fine pattern by inkjet printing a functional ink on the hydrophobic thin film; and forming a fine pattern using inkjet printing. The method of claim 1, The line width of the patterned hydrophobic thin film is fine pattern formation method using inkjet printing, characterized in that the same as or larger than the line width of the fine pattern. Preparing the cleaned substrate: Inkjet printing a hydrophobic ink on a substrate to form a hydrophobic bank used to form a predetermined pattern; And Forming a fine pattern by inkjet printing a functional ink on a region partitioned by the hydrophobic bank. The method of claim 3, In the forming of the hydrophobic bank, the method of forming a fine pattern using inkjet printing may increase the height of the hydrophobic bank by overlaying the hydrophobic ink on a previously formed hydrophobic bank. The method of claim 4, wherein The forming of the fine pattern may include forming a fine pattern having an increased height by inkjet printing the functional ink between the hydrophobic banks having the increased height. The method according to claim 1 or 3, The method of forming a fine pattern using inkjet printing, wherein the hydrophobic ink comprises Teflon. Preparing a cleaned substrate; Ink-jet printing photosensitive ink on the substrate to form a photosensitive bank used for forming a predetermined pattern; Exposing and curing the photosensitive bank formed on the substrate; Forming a fine pattern by inkjet printing functional ink on a region partitioned by the photosensitive bank; And And removing the photosensitive bank by inkjet printing an etchant on the photosensitive bank. The method of claim 7, wherein The forming of the photosensitive bank may include forming an inkjet printing method on the photosensitive bank to increase the height of the photosensitive bank by overlaying the photosensitive ink. The method of claim 8, The forming of the fine pattern may include forming a fine pattern having an increased height by inkjet printing the functional ink between the photosensitive banks of which the height is increased. The method of claim 7, wherein The photosensitive ink is a fine pattern forming method using inkjet printing, characterized in that it comprises a photoresist. The method according to any one of claims 1, 3 or 7, Heating the substrate after preparing the cleaned substrate; The method of forming a fine pattern using inkjet printing, characterized in that at least one inkjet printing is performed while the substrate is heated. The method according to any one of claims 1, 3 or 7, After the forming of the fine pattern, the method of forming a fine pattern further comprising a post-treatment step for expressing the characteristics of the functional ink. The method according to any one of claims 1, 3 or 7, The method of forming a fine pattern, characterized in that the functional ink has conductivity.

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