Device and method for forming a conductive micro-pattern

Abstract

The present invention relates to an apparatus and method for forming a conductive micro-pattern, in which all processes are simplified using an inkjet printing method, and thus a substrate having a micro-pattern of less than 20 μm can be manufactured quickly. To this end, a method for forming a conductive micro-pattern according to the present invention forms a conductive micro-pattern on a substrate having the same surface energy by using an inkjet printing that prints ink along a path. The method for forming a conductive micro-pattern includes a droplet ejection process of simultaneously performing the following steps: discharging a photocurable ink at a front side of the path; discharging a volatile ink containing fine metal particles at a rear side of the path; and applying light energy to the discharged photocurable ink, wherein the light energy is configured to have a light intensity such that: the photocurable ink is semi-cured and ejected onto the substrate in a gel state, thereby forming a boundary with the liquid volatile ink ejected onto the substrate; and the photocurable ink is completely cured after the ejection of both the photocurable ink and the volatile ink is completed.

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for forming a conductive fine pattern, and more particularly, to an apparatus and a method for forming a conductive fine pattern capable of quickly manufacturing a substrate having a fine pattern of less than 20 μm by simplifying all processes by using an inkjet printing method. Background Art

[0002] In the early stage of the development of printed electronics technology, a technology for printing a conductive pattern using an inkjet printing technology was developed to develop a PCB manufacturing technology using a line width of 80 μm to 150 μm.

[0003] However, although the inkjet printing technology has many advantages, the inkjet printing technology is not widely used in PCB manufacturing because it is difficult to achieve a line width with a high thickness in a PCB and has an expensive manufacturing cost and a low productivity compared to the screen printing technology.

[0004] Therefore, the current inkjet printing technology is used only in extremely limited ranges, such as a process for manufacturing PCB products having a line width of 50 μm to 80 μm in small quantities and various types or a process for manufacturing PCB samples in small quantities.

[0005] In recent years, for high integration, next-generation PCBs or high-density interconnect (HDI) boards are manufactured to have fine patterns of less than about 20 μm. Since the screen printing technology has low integration and uniformity and is difficult to use for manufacturing highly integrated PCBs, highly integrated PCBs or HDIs are manufactured by photolithography or laser methods. In particular, high-density PCBs or HDIs for mobile devices are manufactured by expensive manufacturing methods such as photolithography or laser methods.

[0006] On the other hand, the inkjet printing method can directly form a line without using typical processes such as exposure, etching, and electroplating. The inkjet printing method forms fine patterns each having a width of several tens of μm by discharging a solution or a suspension in the form of droplets of several picoliters (pL) to several tens of pL via a micro nozzle.

[0007] Specifically, surface treatment is performed on the surface of the substrate such that the fine pattern is hydrophilic and the remaining part is hydrophobic, and then a fine pattern made of conductive ink is formed on the hydrophilic part.

[0008] More specifically, the micro-pattern is realized by the following method: hydrophobic regions and hydrophilic regions are respectively formed by lithography or by applying a hydrophobic film, a hydrophobic pattern is formed by etching using UV light, and a conductive material is applied to the hydrophobic pattern, and then conductive ink is applied so that all the applied ink is collected in the hydrophilic region.

[0009] Due to the ease of design changes, reduced manufacturing cost of photomasks, and reduced manufacturing process time, the above typical inkjet printing method is gradually and increasingly used.

[0010] However, the method of performing surface treatment on the substrate to make the surface of the substrate hydrophobic or hydrophilic results in high manufacturing costs.

[0011] However, due to the limitations of commercial inkjet heads, the inkjet printing method can achieve ink droplets with a size of 1 pL (diameter of 12.6 μm), so it is basically impossible to achieve a micro-pattern with a size of 20 μm by only using inkjet technology.

[0012] Specifically, when an ink droplet with a size of 1 pL (diameter of 12.6 μm) is ejected and placed on the surface of the substrate, the ink spreads into various sizes based on the surface state. In the case of a general surface state, a line width about three times (35 μm) or about four times (47 μm) that of a general ink droplet can be formed, or when the surface state of the substrate has a hydrophobic property, a line width twice (22 μm) that of the ink droplet can be achieved. However, in essence, it is difficult to achieve a line width smaller than the above sizes required in various application fields, and it is even more difficult to produce products using this process.

[0013] In addition, since the thickness of the micro-pattern decreases when the size of the ink droplet decreases, it is more difficult to achieve a micro-pattern with a higher thickness. Even if a higher thickness is achieved, due to more transmission losses caused by the non-uniform boundary of the micro-pattern, the inkjet printing method cannot be used in practical application fields.

[0014] In some cases, printing is performed by ejecting ink droplets in the case of using a heated substrate and drying the ink droplets using the heat of the substrate. When the ink is dried by heating the substrate, this may cause the solvent in the ink contained inside the nozzle of the head to evaporate to clog the nozzle of the head, resulting in poor printing or making printing itself impossible.

[0015] In addition, since the method of heating the substrate causes thermal expansion of the substrate itself and the inkjet head, precise micro-patterns cannot be achieved due to errors caused by thermal expansion.

[0016] (Related Art: Korean Patent Publication No. 10-2019-0131189, Publication Date: November 26, 2019) Summary of the Invention

[0017] Technical Problem

[0018] The present invention provides an apparatus and method for forming a conductive micro-pattern, which can quickly manufacture a substrate having a micro-pattern of less than 20 μm by simplifying all processes using an inkjet printing method.

[0019] Technical Solution

[0020] To achieve the above technical object, the present invention provides a method for forming a conductive micro-pattern. The method forms a conductive micro-pattern on a substrate having the same surface energy by using an inkjet printing for printing ink along a path. The method includes a droplet ejection process that simultaneously performs all of the following steps: discharging a photocurable ink on the front side of the path, discharging a volatile ink containing fine metal particles on the rear side of the path, and applying light energy to the discharged photocurable ink. Here, the light intensity of the light energy is set such that the photocurable ink in a semi-cured and gel state is ejected onto the substrate to form a boundary with the liquid volatile ink ejected onto the substrate and simultaneously prevent the photocurable ink from spreading. Thus, the photocurable ink is completely cured after all the photocurable ink and the volatile ink are completely ejected.

[0021] In one embodiment, the method may further include a drying process of drying the volatile ink after the droplet ejection process.

[0022] In one embodiment, after the drying process, a thick film process of additionally ejecting the volatile ink onto the conductive micro-pattern formed by drying the volatile ink and drying the volatile ink may be performed at least once.

[0023] In one embodiment, each of the photocurable ink and the volatile ink may be discharged in a droplet size of 2 picoliters (pL) or less. The photocurable ink may be ejected onto an insulating region to form a non-conductive region, and the volatile ink may be ejected onto a conductive region to form a conductive micro-pattern.

[0024] In one embodiment, the insulating region may include a plurality of linear regions spaced apart from each other, and the conductive region may include a region between the plurality of linear regions.

[0025] In one embodiment, the photocurable ink may be discharged through a plurality of nozzles of a first discharge head, the plurality of nozzles of the first discharge head being arranged in a direction perpendicular to the path. The volatile ink may be discharged through a plurality of nozzles of a second discharge head, the plurality of nozzles of the second discharge head being arranged in a direction perpendicular to the path. And the plurality of nozzles of the first discharge head and the plurality of nozzles of the second discharge head may be alternately arranged based on the path.

[0026] In one embodiment, the nozzles of the first discharge head and the nozzles of the second discharge head may be alternately arranged such that the outermost nozzle of the second discharge head is disposed inside the outermost nozzle of the first discharge head.

[0027] In one embodiment, the first discharge head and the second discharge head may have the same width to cover the entire width of the substrate and may be arranged in series in the front-rear direction of the path.

[0028] To achieve this technical objective, the present invention provides an apparatus for forming a conductive micro-pattern. The apparatus forms a conductive micro-pattern on a substrate having the same surface energy by using an inkjet printing method of printing ink along a path. The apparatus includes: a first discharge head configured to eject a photocurable ink at the front side of the path; a second discharge head configured to eject a volatile ink containing fine metal particles at the rear side of the path simultaneously with the first discharge head; and a light irradiator configured to apply light energy to the photocurable ink discharged from the first discharge head. Here, the intensity of the light energy of the light irradiator is set such that: the gel photocurable ink discharged from the first discharge head and traveling in parallel is ejected onto the substrate to form a boundary with the ejected volatile ink discharged from the second discharge head and simultaneously prevent the photocurable ink from spreading, whereby the gel photocurable ink is completely cured after all the photocurable ink and the volatile ink are completely ejected.

[0029] In one embodiment, the first discharge head may be configured to eject photocurable ink droplets of 2 pL or less onto an insulating region of the substrate to be formed as a non-conductive region, and the second discharge head may be configured to eject volatile ink droplets of 2 pL or less onto a conductive region of the substrate to be formed as a conductive micro-pattern.

[0030] In one embodiment, the non-conductive region may include a plurality of regions spaced apart from each other, and the conductive region may include a region between the non-conductive regions.

[0031] In one embodiment, the photocurable ink may be discharged through the nozzles of the first discharge head, the nozzles of the first discharge head are arranged in a direction perpendicular to the path, the volatile ink may be discharged through the nozzles of the second discharge head, the nozzles of the second discharge head are arranged in a direction perpendicular to the path, and the nozzles of the first discharge head and the nozzles of the second discharge head may be alternately arranged based on the path.

[0032] In one embodiment, the nozzles of the first discharge head and the nozzles of the second discharge head may be alternately arranged such that the outermost nozzle of the second discharge head is disposed inside the outermost nozzle of the first discharge head.

[0033] In one embodiment, the first discharge head and the second discharge head may have the same width to cover the entire width of the substrate and are arranged in series in the front-rear direction of the path.

[0034] Advantageous effects

[0035] The present invention described above has the advantage of quickly manufacturing a substrate having a micro-pattern of less than 20 μm by simplifying all processes using an inkjet printing method.

[0036] The object of the present invention is not limited to the above object, but other objects not described herein will be clearly understood by those skilled in the art from the following description. Description of the drawings

[0037] Figure 1 is a diagram for explaining the operation of main components of an apparatus for forming a conductive micro-pattern according to an embodiment of the present invention.

[0038] Figure 2 is a flowchart illustrating the sequence of a method for forming a conductive micro-pattern according to an embodiment of the present invention.

[0039] Figure 3 is a schematic diagram of an apparatus for forming a conductive micro-pattern according to an embodiment of the present invention.

[0040] Figure 4 is a schematic diagram of an apparatus for forming a conductive micro-pattern according to another embodiment of the present invention. Detailed description of the invention

[0041] The present invention can be implemented in various embodiments without departing from the technical idea or main features. Therefore, the embodiments of the present invention are merely illustrative and are not to be construed as limiting.

[0042] It should be understood that although terms such as "first" and "second" are used herein to describe various elements, these elements should not be limited by these terms.

[0043] These terms are only used to distinguish one component from other components. For example, without departing from the scope of the appended claims, a first element that is referred to as the first element in one embodiment may be referred to as the second element in another embodiment.

[0044] As used herein, the term and / or includes any item and all combinations of one or more of the related listed items.

[0045] It should also be understood that when an element is referred to as being "connected to" another element or "engaged with" another element, it can be directly connected to that other element, or there may also be an intermediate element.

[0046] It will also be understood that when an element is referred to as being “directly connected to” another element, there is no intervening element.

[0047] In the following description, technical terms are used only to illustrate specific exemplary embodiments and do not limit the present invention. Unless otherwise mentioned, terms in the singular form may include the plural form.

[0048] The meaning of “comprising” or “including” specifies features, quantities, steps, processes, elements, components, or combinations thereof in the specification, but does not exclude other features, quantities, steps, processes, elements, components, or combinations thereof.

[0049] Unless the terms used in this disclosure are differently defined, these terms can be interpreted as having meanings known to those skilled in the art.

[0050] Terms such as those commonly used and already in a dictionary should be interpreted as having meanings that match the context in the art. In this specification, unless explicitly defined, terms are not ideally over-interpreted into a formal meaning.

[0051] Hereinafter, embodiments disclosed in this specification will be described with reference to the drawings, and regardless of the reference numerals of the drawings, the same or corresponding components are given the same reference numerals, and their repeated description will be omitted.

[0052] In addition, detailed descriptions related to well-known functions or configurations will be excluded so as not to unnecessarily obscure the subject matter of the present invention.

[0053] A device for forming a conductive micropattern according to an embodiment of the present invention (hereinafter referred to as a conductive micropattern forming device) includes main components of a first discharge head 100, a second discharge head 200, and a light irradiator 300. The device forms a conductive micropattern on a substrate having the same surface energy by using an inkjet printing method for ejecting ink along a printing path. Reference will be made to Figure 1 and Figure 3 to describe the detailed configuration including the main components.

[0054] As Figure 1 and Figure 3 shown, the conductive micropattern forming device includes: a substrate moving device that moves the substrate to form a conductive micropattern thereon; a first discharge head 100 that discharges a photocurable ink on the front side in the moving direction of the substrate; a light irradiator 300 that is directly provided behind the first discharge head 100; and a second discharge head 200 that is provided on the rear side in the moving direction of the substrate for discharging a volatile ink containing fine metal particles.

[0055] The first discharge head 100, the light irradiator 300, and the second discharge head 200 are directly adjacent to each other in sequence.

[0056] Specifically, when the photocurable ink discharged from the first discharge head 100 travels in parallel and is ejected onto the substrate in a gel state, the photocurable ink forms a boundary with the volatile ink discharged and ejected from the second discharge head 200, and prevents the spreading of the photocurable ink. The light irradiator 300 has a light energy intensity set such that the photocurable ink is completely cured after all the photocurable ink and the volatile ink are completely ejected.

[0057] Particularly, since the volatile ink is discharged from the second discharge head 200 before the photocurable ink discharged from the first discharge head 100 is ejected onto the substrate and completely cured, and thus the volatile ink is ejected before the photocurable ink is ejected onto the substrate and completely spreads, the spreading of the photocurable ink can be prevented, and the area onto which the photocurable ink is ejected is reduced.

[0058] As Figure 1 and Figure 3 shown, each of the first discharge head 100 and the second discharge head 200 has a length sufficient to cover the entire width of the substrate to form a pattern over the entire area of the substrate through a single printing process.

[0059] Here, the first discharge head 100 and the second discharge head 200 have the same length and are arranged in series in the front-rear direction of the path.

[0060] The first discharge head 100 may include a plurality of nozzles n1 arranged in a direction perpendicular to the path, and eject photocurable ink droplets with a volume of 2 picoliters (pL) or less onto the insulating region of the substrate to be formed as a non-conductive region. Alternatively, the first discharge head 100 may eject photocurable ink droplets with a volume of 0.6 pL or less according to the inkjet discharge atmosphere (helium atmosphere).

[0061] The second discharge head 200 may include a plurality of nozzles n2 arranged in a direction perpendicular to the path, and eject volatile ink droplets with a volume of 2 pL or less onto the conductive region of the substrate to be formed as a conductive micro-pattern. Alternatively, the second discharge head 200 may eject volatile ink droplets with a volume of 0.6 pL or less according to the inkjet discharge atmosphere (helium atmosphere).

[0062] Here, as Figure 1 shown, the plurality of nozzles n1 of the first discharge head 100 and the plurality of nozzles n2 of the second discharge head 200 are alternately arranged based on the path, and specifically, are alternately arranged with a difference of half of the resolution pitch to be printed.

[0063] Here, the outermost nozzle n2 of the second discharge head 200 is disposed inside the outermost nozzle n1 of the first discharge head 100, and the photo-curable ink is discharged from the outermost nozzle n1 so that the photo-curable ink is discharged on the four edges of the substrate to prevent the volatile ink discharged from the second discharge head 200 from flowing outside the substrate.

[0064] The non-conductive regions include a plurality of linear regions spaced apart from each other, the conductive regions may include linear regions disposed between the non-conductive regions, and each of the non-conductive regions and the conductive regions may be a preset virtual region disposed on the surface of the substrate (in particular, the surface of the substrate having the same surface energy).

[0065] As Figure 3 shown, the substrate moving device performs a linear movement (upward movement in the figure) of the substrate along the Y1 stage.

[0066] In addition to the first discharge head 100, the light irradiator 300, and the second discharge head 200, the ink droplet precision measurement camera and the substrate height measurement device are also mounted on the vertically moving Z stage to move together, and the Z stage linearly moves along the X stage.

[0067] The vertical movement of the Z stage and the movement of the Z stage along the X stage can be performed by a driving unit such as a linear motor and a linear guide.

[0068] As described above, the first discharge head 100, the light irradiator 300, and the second discharge head 200 are assembled to the Z stage and moved together by one driving unit.

[0069] The Y2 stage is disposed adjacent to and parallel to the Y1 stage, and an ink droplet precision measurement substrate for measuring the precision of the ejected ink droplets discharged from each of the first discharge head 100 and the second discharge head 200 is disposed on the Y2 stage.

[0070] In addition, a head maintenance device for maintaining the first discharge head 100 and the second discharge head 200 is disposed on the Y2 stage.

[0071] In addition, an ink droplet sphere formation height measurement camera for measuring the sphere formation height of the ink droplets discharged from each of the first discharge head 100 and the second discharge head 200 is disposed on the Y2 stage.

[0072] All the ink droplet precision measurement substrates, the head maintenance device, and the ink droplet sphere formation height measurement cameras are assembled into one body to linearly move along the Y2 stage.

[0073] In addition, the NIR drying module can be mounted at the rear side of the Y1 stage to make the process of drying the substrate moving along the Y1 stage fast and convenient, and to quickly perform the printing process of the volatile ink multiple times.

[0074] The above inkjet printing device can be installed in a sealed space with a helium atmosphere, and can perform the process of forming a gel partition wall by discharging a photocurable ink from the first discharge head 100 and the process of forming a conductive pattern by inkjet discharging a volatile liquid between the gel partition walls from the second discharge head 200 under the helium atmosphere.

[0075] The above inkjet printing device can be installed in a closed space with a helium atmosphere to perform the process of forming a conductive pattern under the helium atmosphere, thereby inkjet discharging a photocurable ink from the first discharge head 100 in the form of ink droplets with a smaller size, and inkjet discharging a volatile ink from the second discharge head 200 in the form of ink droplets with a smaller size.

[0076] In particular, since the density of helium (0.1785 kg / m3) is about 15% of the density of air (1.2 kg / m3), the terminal velocity of the ink droplets can be increased. More particularly, although ink droplets with a discharge volume of 0.6 pL or less are discharged, due to the low molecular weight of helium, the helium atmosphere can reduce the air (gas) resistance to maintain a sufficient discharge speed and a sufficient travel distance.

[0077] As Figure 4 shown, the conductive micropattern forming device according to another embodiment of the present invention includes main components such as a first discharge head 100A on one side, a light irradiator 300A on one side, a second discharge head 200, a light irradiator 300B on the other side, and a first discharge head 100B on the other side. These main components are arranged in series and adjacent to each other in sequence, and will be described with reference to Figure 4 this.

[0078] As Figure 4 shown, the conductive micropattern forming device according to another embodiment of the present invention includes a substrate moving device that performs linear movement of the substrate in two directions along the Y1 stage.

[0079] That is, the substrate moving device allows the substrate to move upward or downward in the figure or move in two directions in the figure.

[0080] For example, when the substrate moving device allows the substrate to move from the lower side to the upper side of the figure based on the X stage, a pattern is formed by operating the first discharge head 100A on one side that discharges a photocurable ink on the front side of the moving direction of the substrate, the light irradiator 300A adjacent to the first discharge head 100A on one side, and the second discharge head 200 that discharges a volatile liquid at the rear side of the moving direction of the substrate.

[0081] In contrast, when the substrate moving device allows the substrate to move from the upper side to the lower side of the figure based on the X stage, a pattern is formed by operating the other first discharge head 100B that discharges the photocurable ink on the front side in the moving direction of the substrate, the other light irradiator 300B disposed adjacent to the other first discharge head 100B, and the second discharge head 200 that is disposed at the rear side in the moving direction of the substrate and discharges the volatile liquid.

[0082] When the conductive micro-pattern forming device according to another embodiment of the present invention performs inkjet printing multiple times on one substrate, the ink can be printed on the substrate while the substrate reciprocates from the lower side to the upper side and from the upper side to the lower side based on the X stage, and the moving path of the substrate can be shorter than the moving path of the foregoing embodiment to allow faster operation.

[0083] The arrangement relationship between the nozzles of the first discharge head 100 and the second discharge head 200 according to the foregoing embodiment will be equally applied to the arrangement relationship between the nozzles of the first discharge head 100A on one side and the second discharge head 200, and the arrangement relationship between the nozzles of the other first discharge head 100B and the second discharge head 200.

[0084] Hereinafter, a method of forming a conductive micro-pattern by using the above conductive micro-pattern forming device according to an embodiment of the present invention will be described in detail.

[0085] A method for forming a conductive micro-pattern by using inkjet printing for printing ink along a path on a substrate having the same surface energy may include a droplet ejection process, a drying process, a thick film process, a curing process, and a partition wall removal process.

[0086] First, the droplet ejection process will be described.

[0087] As shown in Figure 2 (a) of, the droplet ejection process simultaneously performs all of the following operations: discharging the photocurable ink through the first discharge head 100 located at the front side of the printing path, discharging the volatile ink containing fine metal particles through the second discharge head 200 located at the rear side of the printing path, and applying light energy to the discharged photocurable ink through the light irradiator 300.

[0088] Specifically, in the droplet ejection process, the intensity of the light energy is set such that: when the photocurable ink in a semi-cured and gel state is ejected onto the substrate, a gel partition wall is formed to form a boundary with the liquid volatile ink ejected onto the substrate and simultaneously prevent the photocurable ink from spreading, and the photocurable ink is completely cured after all the photocurable ink and the volatile ink are completely ejected.

[0089] Thus, by ejecting the volatile ink before ejecting the photocurable ink onto the substrate and completely spreading it, the spreading of the photocurable ink is prevented, resulting in the effect of reducing the area onto which the photocurable ink is ejected.

[0090] That is, when the light energy applied to the ejected photocurable ink is set as described above, the photocurable ink in a semi-cured and gel state rather than a fully cured state is ejected to form the partition walls, and the volatile ink is ejected between the partition walls before the gel partition walls spread on the substrate to prevent the gel partition walls from spreading.

[0091] More particularly, in a typical droplet ejection process, fully cured partition walls are formed after the photocurable ink is ejected onto the substrate, and then a conductive pattern is formed by ejecting the volatile ink between the partition walls. In this case, since the photocurable ink is ejected onto the substrate and then spreads until it is cured, each of the partition walls in the partition walls may have a large thickness, so the conductive pattern may not have a minute spacing distance between them.

[0092] In an embodiment of the present invention, the volatile ink is ejected between the partition walls before the gel partition walls made of the ejected photocurable ink spread on the substrate to prevent the gel partition walls from spreading, the thickness of the partition walls can be reduced, and thus the conductive pattern can have a minute spacing distance between them.

[0093] Each of the photocurable ink ejected from the first ejection head 100 and the volatile ink ejected from the second ejection head 200 can be ejected with a droplet size of 2 pL or less (0.6 pL or less in a helium atmosphere), the photocurable ink can be ejected onto the insulating region to form a non-conductive region, and the volatile ink can be ejected onto the conductive region to form a conductive micro-pattern.

[0094] Each of the insulating region and the conductive region can be defined as a preset virtual region having the same surface energy on the substrate.

[0095] Specifically, as shown in (a) of Figure 2 , the insulating region includes a plurality of linear regions spaced apart from each other, and the conductive region includes a linear region between the insulating regions.

[0096] As shown in Figure 1 , the photocurable ink can be ejected through the plurality of nozzles n1 of the first ejection head 100 arranged in a direction perpendicular to the path, and the volatile ink can be ejected through the plurality of nozzles n2 of the second ejection head 200 arranged in a direction perpendicular to the path, and the plurality of nozzles n1 of the first ejection head 100 and the plurality of nozzles n2 of the second ejection head 200 can be alternately arranged based on the path.

[0097] Next, the drying process will be described.

[0098] The drying process is performed after the droplet ejection process to dry the volatile ink. As Figure 2 shown in (b) of, the volatile ink ejected onto the substrate is dried to form a primary conductive micropattern on the substrate through fine metal particles.

[0099] Next, the thick film process will be described.

[0100] As Figure 2 shown in (c) and (d) of, after the drying process, the thick film process is used to thicken the pattern by the following steps: additionally ejecting the volatile ink onto the primary conductive micropattern formed by the drying of the volatile ink, and then additionally drying the additionally ejected volatile ink to form a secondary conductive micropattern, thereby thickening the thickness of the entire pattern. The thick film process can be performed at least once or omitted.

[0101] Finally, after completing the above processes, a curing process for curing the secondary conductive micropattern as shown in (e) of Figure 2 and a partition wall removal process for removing the partition wall as shown in (f) of Figure 2 can be additionally performed. When all the above processes are completed, a substrate on which a final conductive micropattern is formed can be obtained.

[0102] Although embodiments of the present invention have been described, it should be understood that the present invention should not be limited to these embodiments, but various changes and modifications can be made by those of ordinary skill in the art within the spirit and scope of the present invention as claimed below.

Claims

1. A method for forming a conductive micro-pattern, the method forming a conductive micro-pattern on a substrate having the same surface energy by using inkjet printing for printing ink along a path, the method including a droplet ejection process that simultaneously performs all of the following steps: discharging a photocurable ink on the front side of the path, discharging a volatile ink containing fine metal particles on the rear side of the path, and applying light energy to the discharged photocurable ink, Among them, The light intensity of the light energy is set such that: the photocurable ink in a semi-cured and gel state that is not fully cured is ejected onto an insulating region of the substrate to form a partition wall in the semi-cured and gel state, and the liquid volatile ink corresponding to a portion between the partition wall in the semi-cured and gel state and the partition wall ejected onto a conductive region of the substrate forms a boundary with the partition wall in the semi-cured and gel state to prevent the photocurable ink from spreading on the substrate, and the photocurable ink is converted from a semi-cured state to a fully cured state after all of the photocurable ink and the volatile ink are completely ejected, and wherein, the thickness of the partition wall in the semi-cured and gel state and the distance between the conductive micro-patterns are reduced due to the light energy having the set intensity.

2. The method according to claim 1, the method further including a drying process for drying the volatile ink after the droplet ejection process.

3. The method according to claim 2, wherein After the drying process, a thick film process of ejecting the volatile ink onto the conductive micro-pattern formed by the drying of the volatile ink and drying the volatile ink is performed at least once.

4. The method according to claim 1, wherein, Each of the photocurable ink and the volatile ink is discharged in a droplet size of 2 picoliters (pL) or less, wherein, the photocurable ink is ejected onto an insulating region to form a non-conductive region, and the volatile ink is ejected onto a conductive region to form a conductive micro-pattern.

5. The method according to claim 4, wherein, The insulating region includes a plurality of linear regions spaced apart from each other, and the conductive region includes a region between the plurality of linear regions.

6. The method according to claim 1, wherein, The photocurable ink is discharged through a plurality of nozzles of a first discharge head, and the plurality of nozzles of the first discharge head are arranged in a direction perpendicular to the path, The volatile ink is discharged through a plurality of nozzles of a second discharge head, and the plurality of nozzles of the second discharge head are arranged in a direction perpendicular to the path, and the plurality of nozzles of the first discharge head and the plurality of nozzles of the second discharge head are alternately arranged based on the path.

7. The method according to claim 6, wherein, The plurality of nozzles of the first discharge head and the plurality of nozzles of the second discharge head are alternately arranged such that the outermost nozzle of the second discharge head is provided inside the outermost nozzle of the first discharge head.

8. The method according to claim 6, wherein The first discharge head and the second discharge head have the same width to cover the entire width of the substrate, and are arranged in series in the front-rear direction of the path.

9. An apparatus for forming a conductive micro-pattern, the apparatus forming a conductive micro-pattern on a substrate having the same surface energy by using an inkjet printing method for printing ink along a path, the apparatus including: The first discharge head protrudes, and the first discharge head is configured to eject a photocurable ink at the front side of the path; A second discharge head, the second discharge head being configured to eject a volatile ink containing fine metal particles at the rear side of the path simultaneously with the first discharge head; And A light irradiator, the light irradiator being configured to apply light energy to the photocurable ink discharged from the first discharge head, wherein the intensity of the light energy of the light irradiator is set such that: the gel photocurable ink discharged from the first discharge head and traveling and ejected onto the insulating region of the substrate is in a semi-cured and gel state that is not fully cured to form the semi-cured and gel state partition wall, and the liquid volatile ink discharged from the second discharge head and ejected onto the conductive region of the substrate corresponding to the portion between the semi-cured and gel state partition walls forms a boundary with the semi-cured and gel state partition wall to prevent the photocurable ink from spreading on the substrate, and the photocurable ink is converted from the semi-cured state to the fully cured state after all the photocurable ink and the volatile ink are completely ejected, and wherein the thickness of the semi-cured and gel state partition wall and the distance between the conductive micro-patterns are reduced due to the light energy having the set intensity.

10. The apparatus according to claim 9, wherein, The first discharge head is configured to eject photocurable ink droplets of 2 pL or less onto the insulating region of the substrate to be formed as a non-conductive region, and The second discharge head is configured to eject volatile ink droplets of 2 pL or less onto the conductive region of the substrate to be formed as conductive micro-patterns.

11. The device according to claim 10, wherein, The non-conductive regions include a plurality of regions spaced apart from each other, and the conductive regions include regions between the non-conductive regions.

12. The device according to claim 9, wherein, The photocurable ink is discharged through a plurality of nozzles of the first discharge head, and the plurality of nozzles of the first discharge head are arranged in a direction perpendicular to the path, The volatile ink is discharged through a plurality of nozzles of the second discharge head, and the plurality of nozzles of the second discharge head are arranged in a direction perpendicular to the path, and The plurality of nozzles of the first discharge head and the plurality of nozzles of the second discharge head are alternately arranged based on the path.

13. The apparatus according to claim 12, wherein, The plurality of nozzles of the first discharge head and the plurality of nozzles of the second discharge head are alternately arranged such that the outermost nozzle of the second discharge head is disposed inside the outermost nozzle of the first discharge head.

14. The device according to claim 12, wherein, The first discharge head and the second discharge head have the same width to cover the entire width of the substrate and are arranged in series in the front-rear direction of the path.

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