KR102504742B1 - Inkjet printing method and wire manufactured by the same - Google Patents

Abstract

An inkjet printing method and wiring manufactured by the inkjet printing method are provided. An inkjet printing method is an inkjet printing method for forming a wire having a first width and extending in a first direction using an inkjet head having a plurality of nozzles ejecting conductive ink, wherein the inkjet head is used in a direction different from the first direction. firstly ejecting conductive ink from the first line to the second line while moving in two directions, shifting the inkjet head by a first distance in the first direction, and moving the inkjet head in a direction opposite to the second direction and secondarily ejecting conductive ink from the third line to the fourth line, wherein the second line is located between the third and fourth lines, and the distance between the first and second lines is shorter than the first width. can Therefore, when forming a wire by using the inkjet printing method according to an embodiment of the present invention, after spraying the first conductive ink, the inkjet head is shifted by a certain distance to spray the second conductive ink, By making the starting point of spraying different from the starting point of spraying the primary conductive ink, it is possible to reduce disconnection of wires due to line breakage.

Description

Inkjet printing method and wiring manufactured thereby

The present invention relates to an inkjet printing method and a wire manufactured thereby, and relates to an inkjet printing method capable of solving the problem of disconnection in a wire when manufacturing the wire using the inkjet printing method, and to a wire manufactured thereby.

In general, as a method for forming a wire on a substrate, there is a method of using an inkjet printing device by converting metal into conductive ink. The inkjet printing apparatus has an advantage in that wires having a desired shape can be freely formed on a substrate by adjusting the position, moving speed, and ejection speed of nozzles formed on the head.

An inkjet printing device includes an inkjet head having a plurality of nozzles ejecting conductive ink. The inkjet head moves toward the substrate on which the wiring is to be formed, and prints the wiring on the substrate in such a manner as to open a nozzle to eject conductive ink based on a predetermined shape of the wiring.

However, when any one of the plurality of nozzles formed in the inkjet head is clogged, conductive ink is not normally ejected from the nozzle, so that a wire is not connected and a line breakage phenomenon may occur. Also, when bubbles are generated in any one of a plurality of nozzles formed in the inkjet head, the conductive ink ejected from the nozzle may be bent in one direction and ejected. Accordingly, a line breakage phenomenon in which the wires are not connected and are cut off in the middle may occur. In addition, when the sequentially ejected conductive ink is bent in one direction by the surface tension of an ink pattern already disposed on the substrate and disposed on the substrate, the conductive ink that needs to connect two ink patterns connects the corresponding ink patterns. Failure to do so may result in line breakage.

The above-described line breakage is not a major problem in the process of forming a wire extending in a direction parallel to the direction in which the inkjet head moves, but in the process of forming a wire extending in a direction perpendicular to the direction in which the inkjet head moves. becomes a problem in For example, when a wire extends in a first direction and an inkjet head moves in the first direction to inject conductive ink, even if a line break occurs at an arbitrary position of the wire, the wire itself extends in the first direction. Since it is made up of parts, current can flow through each part. In addition, if two parts of the wire extending in the first direction are electrically connected to a wire extending in a direction other than the first direction, current may flow through the two parts of the wire extending in the first direction, respectively. , wiring can transmit electrical signals normally.

However, when the wiring extends in the first direction and the inkjet head sprays conductive ink while moving in the second direction perpendicular to the first direction, if a line break occurs at an arbitrary position of the wiring, the left wiring and the right wiring are separated. , and the wiring is electrically disconnected. When disconnection occurs in the wiring, the wiring is determined to be defective because current cannot flow through the wiring.

Due to the disconnection problem, there is an increasing possibility that a printed circuit board may be manufactured defectively. Accordingly, it is necessary to prevent line breakage and minimize defects due to disconnection.

[Related technical literature]

1. Inkjet device and manufacturing method of display panel using the same (Korean Patent Application No. 10-2012-0123861)

As described above, the inventors of the present invention determine the spraying order of the nozzles according to the order in which the nozzles arrive at the position where the wiring is to be formed on the substrate, and in this process, the conductive ink droplets ejected from the nozzles are deflected in one direction. It was recognized that disconnection of wiring may occur. In addition, the inventors of the present invention have recognized that disconnection may occur in the wiring even when conductive ink is not ejected from any one nozzle due to air inflow into the nozzle or other nozzle defects.

Accordingly, an object to be solved by the present invention is to provide an inkjet printing method that can easily solve the problem of disconnection of wires by changing the inkjet printing process without mechanically changing the inkjet head, and to provide a wire manufactured by the inkjet printing method.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, an inkjet printing method according to an embodiment of the present invention is provided. An inkjet printing method according to an embodiment of the present invention is an inkjet printing method for forming a wire extending in a first direction and having a first width by using an inkjet head having a plurality of nozzles for ejecting conductive ink. firstly ejecting conductive ink from the first line to the second line while moving the head in a second direction different from the first direction; shifting the inkjet head by a first distance in the first direction; and secondarily ejecting conductive ink from a third line to a fourth line while moving in opposite directions of the two directions, wherein the second line is located between the third and fourth lines, and between the first and second lines. The separation distance of may be shorter than the first width. Therefore, when forming a wire by using the inkjet printing method according to an embodiment of the present invention, after spraying the first conductive ink, the inkjet head is shifted by a certain distance to spray the second conductive ink, By making the starting point of spraying different from the starting point of spraying the primary conductive ink, it is possible to reduce disconnection of wires due to line breakage.

The first line and the fourth line may be the same line, and the separation distance between the third line and the fourth line may be equal to the first width.

The fourth line may be located between the first line and the second line, and the separation distance between the first line and the third line may be equal to the first width.

The first line and the second line may be positioned between the third line and the fourth line, and a separation distance between the third and fourth lines may be equal to the first width.

The plurality of nozzles of the inkjet head form a plurality of nozzle units that are repeated along the longitudinal direction of the inkjet head, and each of the plurality of nozzle units is a first nozzle area in which nozzles are sequentially arranged along an oblique direction in the row direction in odd-numbered rows. and a second nozzle area in which nozzles are sequentially disposed in an even-numbered row in a direction parallel to the oblique direction.

Each of the plurality of nozzle units is composed of 2m (m is an integer of 3 or more) nozzles, the number of nozzles disposed in each of the first nozzle area and the second nozzle area is m, and the step of shifting the inkjet head is performed by the following arithmetic and shifting the inkjet head by a first distance that satisfies Equation 1.

[Equation 1]

P<d1<(m-1)*P

(d1 is the first distance, P is the row direction distance between adjacent nozzles)

Each of the plurality of nozzle units is composed of 2m (m is an integer of 3 or more) nozzles, the number of nozzles disposed in each of the first nozzle area and the second nozzle area is m, and the step of shifting the inkjet head is m and shifting the inkjet head by a first distance that satisfies Equation 2 below when m is an even number and Equation 3 below when m is an odd number.

[Equation 2]

d1=(m/2±0.5)*P

[Equation 3]

d1=(m/2)*P

(d1 is the first distance, P is the row direction distance between adjacent nozzles)

The wiring further includes a portion extending in the second direction, and the portion extending in the second direction is the same process as one of the steps of firstly spraying the conductive ink and secondarily spraying the conductive ink. can be formed by

In order to solve the above problems, a wiring according to an embodiment of the present invention is provided. A wire according to an embodiment of the present invention is a wire manufactured by an inkjet printing method using an inkjet head having a plurality of nozzles for injecting conductive ink, and one of one side of the wire and the other side opposite to the one side of the wire. It may include a plurality of concave portions disposed on the sides of the above.

The concave portion may be disposed only on one side of the wiring.

The concave portion may include a plurality of first concave portions disposed on one side of the wiring and a plurality of second concave portions disposed on the other side of the wiring, and the plurality of first concave portions may be disposed to correspond between the plurality of second concave portions. can

The concave portion may include a plurality of first concave portions disposed on one side of the wiring and a plurality of second concave portions disposed on the other side of the wiring, and the plurality of first concave portions and the plurality of second concave portions may be disposed to correspond to each other. can

Other embodiment specifics are included in the detailed description and drawings.

According to the present invention, conductive ink is firstly ejected while moving the same inkjet head in a specific direction, and conductive ink is secondarily ejected while moving the inkjet head by a predetermined length and then moved in the opposite direction to the specific direction, so that the nozzles of the inkjet head Even if a defect occurs, line breakage that may occur in wiring can be reduced.

In addition, since the present invention can form wiring without disconnection by changing only the inkjet printing process without mechanically changing the inkjet head and nozzles formed on the inkjet head, process yield and productivity can be improved in a very simple way. there is.

Effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a schematic diagram illustrating an inkjet printing device used in an inkjet printing method according to an embodiment of the present invention.
2 is a flowchart illustrating an inkjet printing method according to an embodiment of the present invention.
3A to 3E are schematic and plan views illustrating an inkjet printing method according to an embodiment of the present invention and wires manufactured by the method.
4A and 4B are schematic plan views and cross-sectional views for explaining an inkjet printing method according to a comparative example.
5A to 5C are schematic plan views for explaining an inkjet printing method and wires manufactured by the inkjet printing method according to another embodiment of the present invention.
6A to 6C are schematic plan views illustrating an inkjet printing method and wires manufactured by the inkjet printing method according to another embodiment of the present invention.
7 is a schematic plan view for explaining an inkjet head of an inkjet printing apparatus according to an embodiment of the present invention.
FIG. 8 is a schematic diagram for explaining a process of ejecting conductive ink from nozzles of the inkjet head shown in FIG. 7 .
9 is a schematic diagram for explaining an inkjet printing method according to an embodiment of the present invention.
10 is a schematic diagram for explaining an inkjet printing method according to another embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. When 'includes', 'has', 'consists of', etc. mentioned in this specification is used, other parts may be added unless 'only' is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless 'directly' is used, one or more other parts may be located between the two parts.

When an element or layer is referred to as (on) another element or layer, it includes all cases where another element or layer is directly on top of another element or another layer or another element is interposed therebetween.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may also be the second component within the technical spirit of the present invention.

Like reference numbers designate like elements throughout the specification.

The size and thickness of each component shown in the drawings are shown for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated components.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and as those skilled in the art can fully understand, various interlocking and driving operations are possible, and each embodiment can be implemented independently of each other. It may be possible to implement together in an association relationship.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram for explaining an inkjet printing apparatus used in an inkjet printing method according to an embodiment of the present invention. Referring to FIG. 1 , an inkjet printing apparatus 1000 includes an inkjet head 100 , a head fixing unit 200 , a head moving unit 300 and a stage 400 .

The stage 400 includes an upper surface for accommodating the substrate 500 on which wires are to be formed by the inkjet method. That is, the stage 400 is configured to support and hold the substrate 500 . As shown in FIG. 1 , the number of stages 400 may be plural, and each of the plurality of substrates 500 may be accommodated in the plurality of stages 400 . Although not shown in FIG. 1 , the stage 400 may be configured to move along a separate rail.

The inkjet head 100 is a component for injecting conductive ink onto the substrate 500, and includes a plurality of nozzles. The inkjet head 100 is positioned on the stage 400 and has a shape extending in a first direction. The number of inkjet heads 100 may be the same as the number of stages 400 . That is, one inkjet head 100 is arranged to correspond to one stage 400, so that one inkjet head 100 can jet conductive ink onto one substrate 500. However, it is not limited thereto, and a plurality of inkjet heads 100 may be arranged to correspond to one stage 400, and the plurality of inkjet heads 100 may jet conductive ink onto one substrate 500. may be

The head fixing part 200 is a member for fixing the plurality of inkjet heads 100 . The head fixing part 200 has the same shape as the inkjet head 100 extending in the first direction. The head fixing unit 200 may fix the inkjet head 100 through various fixing members, and as the head fixing unit 200 is moved by the head moving unit 300, the inkjet head 100 moves in the same direction. can be moved Also, the head fixing unit 200 may shift the inkjet head 100 in an extending direction of the inkjet head 100 . Shifting of the inkjet head 100 by the head fixing unit 200 will be described later in detail with reference to FIGS. 8 and 9 .

The head moving unit 300 is configured to move the inkjet head 100 by moving the head fixing unit 200 . Specifically, the head moving unit 300 is configured to move the head fixing unit 200 in a second direction different from the first direction and in a direction opposite to the second direction. For example, the head moving unit 300 may cause the head fixing unit 200 to linearly move from one end to the other end of the head moving unit 300 and move linearly from the other end to one end. Accordingly, the head moving unit 300 may have a shape extending in the second direction. In this specification, a reverse direction of a specific direction means a direction of 180 degrees from the specific direction.

Hereinafter, FIGS. 2 to 3E will be referred to together for a detailed description of an inkjet printing method of forming a wire using the inkjet printing apparatus as described above.

2 is a flowchart illustrating an inkjet printing method according to an embodiment of the present invention. 3A to 3E are schematic and plan views for explaining an inkjet printing method and wires manufactured by the inkjet printing method according to an embodiment of the present invention. 2 to 3e, the inkjet printing method according to an embodiment of the present invention uses an inkjet head having a plurality of nozzles for ejecting conductive ink, and lines extending in a first direction and having a first width are formed on a substrate. way to form it. 3B, 3D, and 3E are enlarged plan views for explaining the ink patterns 610 and 620A and wirings disposed on the substrate 500. Referring to FIG.

First, conductive ink is primarily ejected from the first line to the second line while moving the inkjet head 100 in a second direction different from the first direction (S20).

Referring to FIG. 3A , the head moving unit 300 of the inkjet printing apparatus moves the head fixing unit 200 in a second direction. Accordingly, the inkjet head 100 fixed to the head fixing unit 200 is also moved in the second direction, and a plurality of nozzles of the inkjet head 100 are opened while the inkjet head 100 passes over the substrate, and the conductive ink is first injected.

The conductive ink is a kind of composition in a paste state in which particles having excellent conductivity, such as metal particles, are dispersed in a solvent. The conductive ink has fluidity, viscosity and surface tension suitable for printing in a line shape by inkjet printing. The conductive ink may include, as a base, a solvent capable of uniformly dispersing metal particles in a liquid state at room temperature, for example, an organic solvent. In addition, the conductive ink may contain a dispersant that promotes uniform dispersion of the metal particles in the solvent. For example, the organic solvent may be a viscous polar organic material with an alcohol functional group, such as Triethyleneglycolmonoethylether (TGME, C ₈ H ₁₈ O ₄ ), or tetramethylammoniumhydroxide (TMAH, (CH ₃ ) ₄ NOH)). , it can be an alkaline substance. The organic solvent included in the conductive ink may be a polar organic solvent, but this is merely an example. Considering the properties of metal particles, the properties of the dispersant, the properties of the substrate to be printed, the properties of the cleaning solution used in the cleaning process after sintering, etc. Organic solvents with different properties may be included in the conductive ink. The metal particles of the conductive ink may be a metal or metal alloy material having excellent conductivity, such as silver (Ag), copper (Cu), molybdenum (Mo), or chromium (Cr).

In order to examine a specific process of ejecting the conductive ink, referring to FIG. 3B , while the inkjet head 100 moves in the second direction, a plurality of nozzles are opened and a first line L1 is drawn on the substrate 500. Conductive ink is primarily sprayed up to the second line L2. That is, the conductive ink starts to be ejected from the first line L1, and the conductive ink is ejected to the second line L2 while the inkjet head 100 moves in the direction indicated by the arrow in FIG. 3B. Here, the first line L1 is the same line as the actual upper boundary of the wiring to be formed on the substrate 500 . In addition, although the first line L1 and the second line L2 are shown as lines parallel to the first direction in FIG. 3B, it is not limited thereto, and the first line L1 and the second line L2 are It may be an arbitrary line extending in a direction not parallel to the second direction. When the conductive ink is first sprayed, the conductive ink is sprayed not to correspond to the entire width W1 of the wire to be formed, but to correspond only to a part of the wire. That is, the separation distance W2 between the first line L1 and the second line L2 is shorter than the width W1 of the wiring. Accordingly, as shown in FIG. 3B , a first ink pattern 610 having a width W2 shorter than the width W1 of the wiring is formed on the substrate 500 . In FIG. 3B , a lower boundary of a wiring to be formed on the substrate 500 is indicated by a dotted line.

Line breakage may occur in the first ink pattern 610 formed by the primary injection of conductive ink. That is, as described above, when the nozzle is clogged, when bubbles are generated in the nozzle, when a foreign substance is disposed in the nozzle, or when the conductive ink is bent by the surface tension of the ink pattern and disposed on the substrate 500 , A line break phenomenon in which an empty space occurs between the first ink patterns 610 may occur. In addition, since the plurality of nozzles are arranged with regularity in the inkjet head 100, line breakage may also occur in the first ink pattern 610 at specific intervals. Accordingly, in FIG. 3B , the first ink pattern 610 is illustrated by assuming a case in which wires may be disconnected due to line breakage.

Next, the inkjet head 100 is shifted by a first distance in a first direction (S21).

As shown in FIG. 3A , while the inkjet head 100 is moved in the second direction, the inkjet head 100 is shifted in the first direction by a first distance d1. The inkjet head 100 may be shifted in the first direction through a separate member of the head fixing part 200 without the head fixing part 200 moving. Alternatively, the inkjet head 100 may be shifted as the inkjet head 100 moves along with the head fixing unit 200 in the first direction. Also, the inkjet head 100 may be shifted in a direction opposite to the first direction.

In the inkjet printing method according to an embodiment of the present invention, the inkjet head 100 is shifted in a first direction after first ejecting conductive ink. This is to prevent streaks from occurring at the same location during the first and second jetting of the conductive ink, which will be described later, and to fill the gaps in the first ink pattern 610 with conductive ink during the first jetting. As such, the streaking phenomenon can be improved by simply shifting the inkjet head 100 and secondarily ejecting the conductive ink. A detailed description of the first distance d1 by which the inkjet head 100 is shifted will be described later with reference to FIGS. 8 and 9 .

Next, while moving the inkjet head 100 in a direction opposite to the second direction, conductive ink is secondarily ejected from the third line to the fourth line (S22).

Referring to FIG. 3C , the head moving unit 300 of the inkjet printing apparatus 1000 moves the head fixing unit 200 in a direction opposite to the second direction. Accordingly, the inkjet head 100 fixed to the head fixing unit 200 is also moved in a direction opposite to the second direction, and while the inkjet head 100 passes over the substrate 500, the inkjet head 100 moves in a plurality of directions. The nozzle is opened and conductive ink is sprayed secondarily.

In order to examine a specific process of ejecting the conductive ink, referring to FIG. 3D , while the inkjet head 100 moves in the opposite direction to the second direction, a plurality of nozzles are opened and the third line L3 to the fourth line L3 to the fourth line are opened on the substrate. Conductive ink is secondarily injected up to the line L4. That is, the conductive ink starts to be ejected from the third line L3, and the conductive ink is ejected to the fourth line L4 while the inkjet head 100 moves in the direction indicated by the arrow in FIG. 3D. Here, the third line L3 is the same line as the actual lower boundary of the wiring to be formed on the substrate 500, and the fourth line L4 is the same line as the actual upper boundary of the wiring. Accordingly, the first line L1 and the fourth line L4 may be set as the same line. In addition, in FIG. 3D , the third line L3 and the fourth line L4 are shown as lines parallel to the first direction, but are not limited thereto, and the third line L3 and the fourth line L4 are It may be an arbitrary line extending in a direction not parallel to the second direction. When the conductive ink is secondarily sprayed, the conductive ink is sprayed to correspond to the entire width W1 of the wiring to be formed. That is, the separation distance between the third line L3 and the fourth line L4 is equal to the width W1 of the wiring. Accordingly, as shown in FIG. 3D , a second ink pattern 620A having the same width as the width W1 of the wiring is formed on the substrate 500 .

Line breakage may also occur in the second ink pattern 620A formed by secondary jetting of the conductive ink. That is, the conductive ink of the second ink pattern 620A is ejected by the same inkjet head 100 as the conductive ink of the first ink pattern 610, and only the inkjet head 100 moves in the first direction at a first distance ( Since it is only shifted by d1), line breakage may occur at a position different from that of the first ink pattern 610, as shown in FIG. 3D. However, since the second ink pattern 620A fills the disconnected portion of the first ink pattern 610, the first ink pattern 610 and the second ink pattern 620A may form one pattern.

Referring to FIG. 3D , as described above, a line break also occurs in the second ink pattern 620A. That is, the second ink patterns 620A may not be connected to each other in areas that do not overlap with the first ink patterns 610 . However, since both the first ink pattern 610 and the second ink pattern 620A are liquid, the first ink pattern 610 and the second ink pattern 620A move as indicated by arrows in FIG. 3D. , As shown in FIG. 3E , the missing part of the second ink pattern 620A can be significantly removed. When the second ink pattern 620A is formed in a state where the first ink pattern 610 is disposed, as shown in FIG. 3D , a plurality of nozzles extend from the third line L3 to the second line L2. , and when a plurality of nozzles are positioned on the second line L2, the first ink pattern 610 and the second ink pattern 620A meet each other. At this time, parts of the first ink pattern 610 and the second ink pattern 620A flow to the missing part of the second ink pattern 620A as indicated by arrows in FIG. 3D due to the surface tension of the liquid. , finally, a wire 600A having a shape as shown in FIG. 3E may be formed.

After inkjet printing as described above is completed, the first ink pattern 610 and the second ink pattern 620A are cured to form a wire 600A as shown in FIG. 3E. The shape of the wiring 600A is the same as the shape of the first ink pattern 610 and the second ink pattern 620A where the secondary injection is completed. Therefore, as shown in FIG. 3E , a plurality of first concave portions 630A are disposed on one side portion 601A of the wiring 600A, and no concave portions are disposed on the other side portion 602A of the wiring 600A. . In this case, the plurality of first concave portions 630A may be arranged with regularity.

In general, when the wiring 600A is formed through an inkjet printing process, one side 601A and the other side 602A of the wiring 600A are not necessarily formed in a smooth straight shape, and one side 601A or the other side 601A Some of the side portions 602A may have a concavo-convex shape. However, since these shapes are generated due to process deviations or unexpected reasons during the manufacturing process, concavo-convex shapes are generated at random intervals instead of being formed regularly. However, in the inkjet printing method according to an embodiment of the present invention, as the wiring 600A is manufactured while shifting the same inkjet head 100, the defective nozzle is moved at regular intervals and used as it is. . Accordingly, a shape in which line breakage is repeated at regular intervals may occur, and the first concave portions 630A may also be periodically arranged at specific intervals. In addition, if the nozzle is not defective and the line break occurs due to surface tension, since the nozzle arrangement structure in the inkjet head 100 repeatedly arranges a plurality of nozzle units, the line break phenomenon is also repeatedly specified. may occur at intervals. Therefore, the first concave portion 630A of the wiring 600A manufactured by the inkjet printing method according to an embodiment of the present invention is regularly spaced at a specific interval, different from concavo-convex shapes caused by general process deviations. can be formed

In the inkjet printing method according to an embodiment of the present invention, it is possible to improve the phenomenon of line breakage in the wiring through a process of ejecting conductive ink twice through the same inkjet head 100 . As described above, when the conductive ink is ejected once through the inkjet head, a stripping phenomenon may occur in the wiring due to a problem of the nozzle itself or surface tension between the ink pattern formed on the substrate and the conductive ink. However, in the inkjet printing method according to an embodiment of the present invention, conductive ink is primarily ejected while moving the inkjet head 100 in the second direction, and then the inkjet head 100 is moved in the same direction as the extending direction of the wire 600A. shifting in one direction, and secondarily ejecting conductive ink while moving the same inkjet head 100 in a direction opposite to the second direction. Accordingly, the missing lines in the first ink pattern 610 printed by the primary jetting are filled by the second ink pattern 620A printed by the secondary jetting, and the lines in the second ink pattern 620A are filled. By filling the missing portion with the first ink pattern 610 , the line 600A may be prevented from occurring. Accordingly, the problem of disconnection in the wiring 600A manufactured by the inkjet printing method is solved, and process yield and productivity can be improved.

In particular, in the inkjet printing method according to an embodiment of the present invention, the secondary jetting must be started before the inkjet head 100 meets the first ink pattern 610 in the process of secondary jetting of the conductive ink. That is, the second line L2, where the first injection ends, should be located between the third line L3, where the second injection starts, and the fourth line L4, where the second injection ends. do. For example, referring to FIG. 3D , the secondary jetting is performed while the inkjet head 100 moves in a direction opposite to the second direction, and the secondary jetting is performed before the inkjet head 100 meets the first ink pattern 610. should start, and thus the third line L3, where the secondary injection starts, should be positioned lower than the second line L2, where the primary injection ends. For a more detailed description thereof, reference is made to FIGS. 4A and 4B together.

4A and 4B are schematic plan views and cross-sectional views for explaining an inkjet printing method according to a comparative example.

When the secondary jetting starts after the inkjet head meets the first ink pattern 61 during secondary jetting of the conductive ink, the tension between the first ink pattern 61 and the conductive ink 69 controls the Line breakage occurring in the 1 ink pattern 61 may not be improved.

For example, as shown in FIG. 4A, when the secondary jetting starts after the inkjet head meets the first ink pattern 61, that is, the third line L3, which is the starting point of the secondary jetting, When disposed between the first line L1, where the first injection starts, and the second line L2, where the first injection ends, the second ink pattern 62 is as shown in FIG. 4A. Since the first ink pattern 61 is not connected like this, the line breakage phenomenon may not be solved.

Specifically, referring to FIG. 4B , the first ink pattern 61 is already formed on the substrate 50 before the second jetting starts, and there is a line break between the first ink patterns 61 . After that, in the process of starting the secondary jetting, the conductive ink 69 jetted to correspond to the missing line can be jetted by being bent to one side by the large mass of the first ink pattern 61 located on both sides. . If the ejected conductive ink 69 is in contact with the first ink patterns 61 located on both sides exactly, the missing part is filled by the conductive ink 69, but the conductive ink 69 is adjacent to the two first ink patterns 69. When contacting any one of the ink patterns 61 first, the conductive ink 69 is bent in the direction of arrow 1 or arrow 2 and ejected, and the two adjacent first ink patterns 61 are still not connected. A problem exists.

However, in the inkjet printing method according to the embodiment of the present invention shown in FIGS. 3A to 3E , in the process of secondary ejection of the conductive ink, the secondary ejection is performed before the inkjet head 100 meets the first ink pattern 610 . is started For example, referring to FIG. 3D , secondary jetting is performed while the inkjet head 100 moves in a direction opposite to the second direction, and secondary jetting is performed before the inkjet head 100 meets the first ink pattern 610. starts, and the third line L3, which is the part where the secondary injection starts, is located below the second line L2 where the primary injection ends. Accordingly, since the second ink pattern 620A is connected at least below the second line L2 in relation to the part of the first ink pattern 610 where the line break occurs, the line of the first ink pattern 610 The missing phenomenon can be solved.

5A to 5C are schematic plan views for explaining an inkjet printing method and wires manufactured by the inkjet printing method according to another embodiment of the present invention. Since the inkjet printing method shown in FIGS. 5A to 5C is different from the inkjet printing method shown in FIGS. 3A to 3E only in the process of secondary ejection of the conductive ink and the shape of the final wire, duplicate descriptions are omitted.

First, conductive ink is primarily ejected from the first line L1 to the second line L2 while moving the inkjet head 100 in a second direction different from the first direction (S20).

In order to examine a specific process of ejecting the conductive ink, referring to FIG. 5A , while the inkjet head 100 moves in the second direction, a plurality of nozzles are opened and a first line (L1) to a second line ( Conductive ink is first sprayed up to L2). Since the primary jetting of the conductive ink is the same as the primary jetting of the conductive ink described with reference to FIGS. 3A and 3B , redundant description will be omitted.

Subsequently, the inkjet head 100 is shifted in the first direction by a first distance d1 (S21). Since the process of shifting the inkjet head 100 is the same as the process of shifting the inkjet head 100 described with reference to FIGS. 3A to 3E , repeated description will be omitted.

Next, the conductive ink is secondarily ejected from the third line L3 to the fourth line L4 while moving the inkjet head 100 in a direction opposite to the second direction (S22).

Referring to FIG. 5B , while the inkjet head 100 moves in a reverse direction to the second direction, a plurality of nozzles are opened, and conductive ink is discharged from the third line L3 to the fourth line L4 on the substrate 500 . tea is sprayed That is, the conductive ink starts to be ejected from the third line L3, and the conductive ink is ejected to the fourth line L4 while the inkjet head 100 moves in the direction indicated by the arrow in FIG. 5B. Here, the third line L3 is the same line as the actual lower boundary of the wiring to be formed on the substrate 500, and the fourth line L4 is between the first line L1 and the second line L2. That is, during the second injection of the conductive ink, the conductive ink is ejected so that the first ink pattern 610 and the second ink pattern 620B overlap each other. Accordingly, the separation distance between the first line L1 where the conductive ink starts to be ejected during the first injection and the third line L3 where the conductive ink starts to be ejected during the second injection is the width W1 of the wiring. Same as

The line breakage phenomenon may also occur in the second ink pattern 620B formed by the secondary injection of the conductive ink. That is, the conductive ink of the second ink pattern 620B is ejected by the same inkjet head 100 as the conductive ink of the first ink pattern 610, and the inkjet head is ejected only by the first distance d1 in the first direction. Since it is only shifted, line breakage may occur at a position different from that of the first ink pattern 610, as shown in FIG. 5B. However, since the first ink pattern 610 fills the disconnected portion of the second ink pattern 620B and the second ink pattern 620B fills the disconnected portion of the first ink pattern 610, The first ink pattern 610 and the second ink pattern 620B may form one pattern.

In addition, referring to FIG. 5B, since both the first ink pattern 610 and the second ink pattern 620B are liquid, as shown by arrows in FIG. 5B, the first ink pattern 610 and the second ink pattern ( 620B) is moved, and as shown in FIG. 5C , the missing portions of the first ink pattern 610 and the second ink pattern 620B can be considerably removed. That is, parts of the first ink pattern 610 and the second ink pattern 620B flow as indicated by arrows in FIG. 5B due to the surface tension of the liquid, and finally form a shape as shown in FIG. 5C. A wire 600B may be formed.

After inkjet printing as described above is completed, the first ink pattern 610 and the second ink pattern 620B are cured to form a wiring 600B as shown in FIG. 5C. The shape of the wiring 600B is the same as the shape of the first ink pattern 610 and the second ink pattern 620B after the secondary jetting. Accordingly, as shown in FIG. 5C , a plurality of first concave portions 630B are disposed on one side portion 601B of the wiring 600B, and a plurality of second concave portions 630B are disposed on the other side portion 602B of the wiring 600B. A portion 640B is disposed. At this time, the plurality of first concave portions 630B are arranged to correspond between the plurality of second concave portions 640B.

In the inkjet printing method according to another embodiment of the present invention, the stripping phenomenon of the wiring 600B can be improved by a process of ejecting conductive ink twice through the same inkjet head 100 . In particular, in the inkjet printing method according to another embodiment of the present invention, in the process of secondary ejection of the conductive ink, the secondary ejection starts before the inkjet head 100 meets the first ink pattern 610, so that the first ink Since the pattern 610 and the second ink pattern 620B electrically connect the missing lines to each other, the line breaking phenomenon that may occur when the wiring 600B is formed by the inkjet printing method can be minimized.

6A to 6C are schematic plan views for explaining an inkjet printing method and wires manufactured by the inkjet printing method according to another embodiment of the present invention. Since the inkjet printing method shown in FIGS. 6A to 6C is different from the inkjet printing method shown in FIGS. 3A to 3E only in a process of secondary ejection of conductive ink and a final wire shape, a redundant description is omitted.

First, conductive ink is primarily ejected from the first line L1 to the second line L2 while moving the inkjet head 100 in a second direction different from the first direction (S20).

In order to examine a specific process of ejecting the conductive ink, referring to FIG. 6A , while the inkjet head 100 moves in the second direction, a plurality of nozzles are opened and a first line (L1) to a second line ( Conductive ink is first sprayed up to L2). Since the primary jetting of the conductive ink is the same as the primary jetting of the conductive ink described with reference to FIGS. 3A and 3B , redundant description will be omitted.

Subsequently, the inkjet head 100 is shifted in the first direction by a first distance d1 (S21). Since the process of shifting the inkjet head 100 is the same as the process of shifting the inkjet head 100 described with reference to FIGS. 3A to 3E , repeated description will be omitted.

Next, the conductive ink is secondarily ejected from the third line L3 to the fourth line L4 while moving the inkjet head 100 in a direction opposite to the second direction (S22).

Referring to FIG. 6B , while the inkjet head 100 moves in a reverse direction to the second direction, a plurality of nozzles are opened to secondarily eject conductive ink from the third line L3 to the fourth line L4 on the substrate. . That is, the conductive ink starts to be ejected from the third line L3, and the conductive ink is ejected to the fourth line L4 while the inkjet head 100 moves in the direction indicated by the arrow in FIG. 6B. Here, the third line L3 is the same line as the actual lower boundary of the wiring 600C to be formed on the substrate 500, and the fourth line L4 is the same line as the actual upper boundary of the wiring 600C. . That is, the first line (L1) and the second line (L2) are located between the third line (L3) and the fourth line (L4), the separation distance between the first line (L1) and the second line (L2) The distance between the third and fourth lines L3 and L4 is smaller than the width W1 of the wiring 600C and equal to the width W1 of the wiring 600C.

A line breakage phenomenon may also occur in the second ink pattern 620C formed by the secondary injection of the conductive ink. That is, the conductive ink of the second ink pattern 620C is jetted by the same inkjet head 100 as the conductive ink of the first ink pattern 610, and only the inkjet head 100 moves in the first direction at a first distance ( Since it is only shifted by d1), line breakage may occur at a position different from that of the first ink pattern 610, as shown in FIG. 6B. However, since the first ink pattern 610 fills the disconnected portion of the second ink pattern 620C, the first ink pattern 610 and the second ink pattern 620C may form one pattern.

Also, referring to FIG. 6B , since both the first ink pattern 610 and the second ink pattern 620C are liquid, as shown by arrows in FIG. 6B , the first ink pattern 610 and the second ink pattern ( 620C) is moved, and the missing lines of the first ink pattern 610 and the second ink pattern 620C can be significantly removed as shown in FIG. 6C. That is, parts of the first ink pattern 610 and the second ink pattern 620C flow as indicated by arrows in FIG. 6B by the surface tension of the liquid, and finally form a shape as shown in FIG. 6C. A wire 600C may be formed.

After inkjet printing as described above is completed, the first ink pattern 610 and the second ink pattern 620C are cured to form a wire 600C as shown in FIG. 6C. The shape of the wiring 600C is the same as the shape of the first ink pattern 610 and the second ink pattern 620C where the secondary injection is completed. Accordingly, as shown in FIG. 6C , a plurality of first concave portions 630C are disposed on one side portion 601C of the wiring 600C, and a plurality of second concave portions 602C are disposed on the other side portion 602C of the wiring 600C. A portion 640C is disposed. At this time, the plurality of first concave portions 630C are arranged to correspond to the plurality of second concave portions 640C.

In the inkjet printing method according to another embodiment of the present invention, the line breakage phenomenon of the wiring 600C can be improved by a process of ejecting conductive ink twice through the same inkjet head 100 . In particular, in the inkjet printing method according to another embodiment of the present invention, the secondary jetting starts before the inkjet head 100 meets the first ink pattern 610 in the process of secondary jetting of the conductive ink, and Since the secondary jetting continues even in the portion after the ink pattern 610, the first ink pattern 610 electrically connects the missing part of the second ink pattern 620C, so that the wiring 600C is formed by the inkjet printing method. In the case of formation, line breakage that may occur can be minimized.

Hereinafter, reference will be made to FIGS. 7 to 10 for a detailed description of a process of shifting the inkjet head by a first distance in a first direction.

7 is a schematic plan view for explaining an inkjet head of an inkjet printing apparatus according to an embodiment of the present invention. Referring to FIG. 7 , an inkjet head includes a plurality of nozzles, and the plurality of nozzles form a plurality of nozzle units.

Referring to FIG. 7 , the inkjet head 100 includes a plurality of nozzle units 110 . The plurality of nozzle units 110 are repeated along the longitudinal direction of the inkjet head 100, that is, in the first direction. Each of the plurality of nozzle units 110 includes a first nozzle area 120 and a second nozzle area 130 . The plurality of nozzles 121 , 122 , 123 , 124 , 131 , 132 , 133 , and 134 in the first nozzle area 120 and the second nozzle area 130 respectively of the plurality of nozzle units 110 are connected to the inkjet head 100 . ) are arranged in a plurality of rows and a plurality of columns in the first direction, which is the longitudinal direction of the inkjet head 100, and in the second direction, which is the width direction of the inkjet head 100. The first nozzle area 120 and the second nozzle area 130 of the plurality of nozzle units 110 are alternately and repeatedly arranged.

In the first nozzle area 120 of the nozzle unit 110, the first nozzle 121, the second nozzle 122, the third nozzle 123, and the second nozzle 122 are sequentially disposed along an oblique direction in the row direction in odd-numbered rows. 4 nozzles 124 are arranged. That is, in the first nozzle area 120, the first nozzle 121, the second nozzle 122, the third nozzle 123, and the fourth nozzle 124 are disposed skipping one row at a time. In addition, in the second nozzle region 130 of the nozzle unit 110, the first nozzle 131, the second nozzle 132, and the third nozzle 133 are sequentially disposed along an oblique direction in the row direction in even-numbered rows. and a fourth nozzle 134 is disposed. That is, in the second nozzle area 130, the first nozzle 131, the second nozzle 132, the third nozzle 133, and the fourth nozzle 134 are disposed skipping one row at a time. As described above, the first nozzles 121, the second nozzles 122, the third nozzles 123, and the fourth nozzles 124 of the first nozzle region 120 are arranged obliquely in odd-numbered rows, If the first nozzle 131, the second nozzle 132, the third nozzle 133, and the fourth nozzle 134 of the two-nozzle area 130 are obliquely arranged in even-numbered rows, a higher DPI (Dot per inches) is required. In other words, as the number of conductive inks to be ejected per unit length increases, a limit arises in arranging nozzles adjacent to one row. That is, in the process of forming nozzles in the inkjet head 100, a minimum distance between adjacent nozzles in one row is required. When the DPI increases, as many nozzles per unit length are required in one row as the number of nozzles. It may not be possible to place all of them. Therefore, in a high-resolution inkjet head, the nozzles are arranged in an oblique line while being divided into odd-numbered rows and even-numbered rows.

Referring to FIG. 7 , a row direction distance between any one nozzle of the inkjet head 100 and an adjacent nozzle may be the same. For example, as shown in FIG. 7 , the row direction distance between the first nozzle 121 and the second nozzle 122 is P, and the row direction distance between other adjacent nozzles may also be P. It is preferable that the intervals between the nozzles in the row direction are all the same, but the intervals between the nozzles in the row direction are not limited thereto.

The inkjet head fixing unit 200 of the inkjet printing apparatus 1000 according to an embodiment of the present invention is configured to move in a second direction perpendicular to the first direction, while the inkjet head fixing unit 200 moves. The first nozzle 121, the second nozzle 122, the third nozzle 123, and the fourth nozzle 124 of the first nozzle area 120 formed in the inkjet head 100 and the second nozzle area 130 Conductive ink is ejected from the first nozzle 131 , the second nozzle 132 , the third nozzle 133 , and the fourth nozzle 134 . The first nozzle 121, the second nozzle 122, the third nozzle 123, and the fourth nozzle 124 in the first nozzle area 120 and the first nozzle 131 in the second nozzle area 130 , The order in which the conductive ink is ejected from the second nozzle 132 , the third nozzle 133 , and the fourth nozzle 134 is the order of reaching the position on the substrate 500 where the wiring is to be formed first. Specifically, the order in which the conductive ink is ejected is the first nozzle 121 of the first nozzle area 120, the first nozzle 131 of the second nozzle area 130, and the second nozzle of the first nozzle area 120. The nozzle 122, the second nozzle 132 in the second nozzle area 130, the third nozzle 123 in the first nozzle area 120, the third nozzle 133 in the second nozzle area 130, In order of the fourth nozzle 124 in the first nozzle area 120 and the fourth nozzle 134 in the second nozzle area 130, nozzles disposed in the lowest row to nozzles disposed in the uppermost row Conductive ink is ejected in sequence.

FIG. 8 is a schematic diagram for explaining a process of ejecting conductive ink from nozzles of the inkjet head shown in FIG. 7 .

Referring to FIG. 8 , as shown in (a) of FIG. 8 , the first nozzle 121 of the first nozzle area 120 that first reaches the position where the wiring is to be formed on the substrate 500 One ink droplet 121i is formed.

Subsequently, as shown in (b) of FIG. 8 , second ink droplets ejected from the first nozzle 131 of the second nozzle area 130 reach the position where the wiring is to be formed on the substrate 500 next. After 131i is formed, as shown in FIG. , and the first ink droplet 121i and the third ink droplet 122i form one droplet.

8(d) to 8(f), the second nozzle 132 of the second nozzle area 130, the third nozzle 123 of the first nozzle area 120, and the second The conductive ink is sequentially ejected from the third nozzle 133 of the nozzle area 130 to form a fourth ink droplet 132i, a fifth ink droplet 123i, and a sixth ink droplet 133i on the substrate 500, respectively. do.

Subsequently, when conductive ink is normally ejected to form ink droplets, as shown in FIG. A seventh ink droplet 124i is formed between the ink droplet 123i and the second ink droplet 131i. At this time, the conductive ink ejected from the fourth nozzle 124 of the first nozzle region 120 is normally printed, and the seventh ink droplet 124i is formed by the fifth ink droplet 123i and the second ink droplet 131i. connected with

However, the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 by the attraction of the ink droplets may be deflected to one side. For example, as shown in (g2) of FIG. 8 , the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 is moved toward the fifth ink droplet 123i and becomes a seventh ink droplet. (124i) may be formed. Since the first ink droplet 121i, the third ink droplet 122i, and the fifth ink droplet 123i form one droplet in which three ink droplets are aggregated, they may have a greater attractive force than one ink droplet. there is. However, when the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 first contacts the fifth ink droplet 123i, the seventh ink droplet 124i forms the first ink droplet 121i. , may be formed by being deflected toward the fifth ink droplet 123i by the attraction of the third ink droplet 122i and the fifth ink droplet 123i. In this case, the seventh ink droplet 124i does not come into contact with the second ink droplet 131i, and a disconnection occurs in the wiring formed of the conductive ink.

In addition, as shown in (g3) of FIG. 8, the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 first comes into contact with the second ink droplet 131i, It can be deflected and moved towards the droplet 131i. As described above, the second ink droplet 131i, the fourth ink droplet 132i, and the sixth ink droplet 133i may also have a greater attractive force than one ink droplet. Accordingly, when the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 falls on the substrate 500 and first contacts the second ink droplet 131i, the seventh ink droplet 124i It may be formed by being biased towards the second ink droplet 131i. Even in this case, the seventh ink droplet 124i does not come into contact with the fifth ink droplet 123i, and a disconnection occurs in the wiring.

In addition, when bubbles are filled in the fourth nozzle 124 of the first nozzle region 120, the conductive ink ejected from the fourth nozzle 124 of the first nozzle region 120 may be bent in a specific direction and then ejected. Accordingly, even when the conductive ink ejected from the fourth nozzle 124 of the first nozzle area 120 contacts the second ink droplet 131i first or the fifth ink droplet 123i first, as shown in FIG. 8 ( A disconnection problem as shown in g2) and (g3) of FIG. 8 may occur.

Accordingly, the inkjet printing apparatus 100 according to an embodiment of the present invention reduces the occurrence of disconnection when forming wires by the printing method described in FIGS. 9 and 10 below.

9 is a schematic diagram for explaining an inkjet printing method according to an embodiment of the present invention. Each of the plurality of nozzle units 110A of the inkjet head 100 according to an embodiment of the present invention may include 2m (m is an integer of 3 or more) nozzles, and each nozzle unit 110A has a first nozzle area. (120A) and a second nozzle area (130A). In this case, the number of nozzles disposed in the first nozzle area 120A and the second nozzle area 130A is m. Hereinafter, referring to FIG. 9, as an example, when m is an even number, for example, when m=4, four nozzles are disposed in each of the first nozzle area 120A and the second nozzle area 130A. Explain. In addition, it is assumed that among the plurality of nozzles, a nozzle that has a defect or that jets conductive ink in a biased manner is the fourth nozzle 124A or 134A, which is the last nozzle of each nozzle area 120A or 130A. FIG. 9 schematically illustrates a plurality of nozzles of the inkjet head 100 shown in FIG. 7 arranged in one row for convenience of description.

Referring to (a) of FIG. 9 , the first nozzle 121A, the second nozzle 122A, the third nozzle 123A, and the fourth nozzle 124A are provided in the first nozzle area 120A of the nozzle unit 110A. ) is disposed, and the first nozzle 131A, the second nozzle 132A, the third nozzle 133A, and the fourth nozzle 134A are disposed in the second nozzle area 130A. In this case, the distance P between each nozzle in the first nozzle area 120A and the distance P between each nozzle in the second nozzle area 130A are the row direction distance P between adjacent nozzles as described above. ) is the same as

After the nozzle unit 110A disposed as described above moves in the second direction and primarily ejects the conductive ink, as shown in (b) and (c) of FIG. 9 , the head fixing unit 200 The conductive ink is secondarily sprayed while being shifted by the first distance d1 and moving in a direction opposite to the second direction. At this time, the movable range PO and the movable range IPO in which the nozzle unit 110A can be shifted are determined based on the row direction distance P between adjacent nozzles.

Specifically, if the first distance d1 shifted by the fourth nozzle 124A in the first nozzle area 120A is smaller than or equal to P with respect to the fourth nozzle 124A, the fourth nozzle during primary injection 124A causes the fourth nozzle 124A to be disposed at the same position as the position where the conductive ink is not disposed, and the line break occurring during the first jetting may not be filled by the second jetting.

In addition, if the first distance d1 shifted by the fourth nozzle 124A in the first nozzle area 120A is greater than or equal to 3P and less than or equal to 5P with respect to the fourth nozzle 124A, the primary injection In this case, the fourth nozzle 124A is disposed at the same position as the position where the conductive ink is not disposed by the fourth nozzle 134A of the second nozzle area 130A, and the line generated during the first jetting by the second jetting. Missing parts may not be filled.

Accordingly, in the inkjet printing method according to an embodiment of the present invention, the first distance d1 at which the inkjet head is shifted may be expressed by Equation 1 below.

[Equation 1]

P<d1<(m-1)*P

Meanwhile, the first distance d1 may be optimized as in Equation 2 below.

[Equation 2]

d1=(m/2±0.5)*P

Specifically, the first distance d1 by which the inkjet head is shifted is preferably disposed between adjacent nozzles, and more preferably may be disposed in the middle between adjacent nozzles. Accordingly, referring to (b) and (c) of FIG. 9 , when the first distance d1 shifted by the fourth nozzle 124A in the first nozzle area 120A is 1.5P or 2.5P, the fourth While the nozzle 124A is disposed within the range of the first distance d1 proposed in Equation 1, it may be disposed in the middle between adjacent nozzles. Accordingly, the missing line portion generated during the first injection can be efficiently filled by the second injection.

Equations 1 and 2 were written on the assumption that the inkjet head moves in the positive direction by the first distance d1, but is not limited thereto and may move in the negative direction. In addition, as shown in (b) and (c) of FIG. 9, since the movable section PO and the non-movable section IPO are repeated in m units, the first distance d1 is also the movable section PO. ) can be set in various ways according to the number of repetitions.

10 is a schematic diagram for explaining an inkjet printing method according to another embodiment of the present invention. Each of the plurality of nozzle units 110B of the inkjet head 100 according to another embodiment of the present invention may include 2m (m is an integer of 3 or more) nozzles, and each nozzle unit 110B has a first nozzle area. (120B) and a second nozzle area (130B). In this case, the number of nozzles disposed in the first nozzle area 120B and the second nozzle area 130B is m. Hereinafter, with reference to FIG. 10, as an example, when m is an odd number, for example, when m=5, four nozzles are disposed in each of the first nozzle area 120B and the second nozzle area 130B. Explain. In addition, it is assumed that the fifth nozzle 125A or 135B, which is the last nozzle of each nozzle area 120B or 130B, is a nozzle that has a defect or jets conductive ink in a biased manner among the plurality of nozzles. FIG. 10 schematically illustrates a plurality of nozzles of the inkjet head 100 shown in FIG. 7 arranged in one row for convenience of explanation.

Referring to (a) of FIG. 10 , the first nozzle 121B, the second nozzle 122B, the third nozzle 123B, and the fourth nozzle 124B are provided in the first nozzle area 120B of the nozzle unit 110B. ) and the fifth nozzle 125B are disposed, and the first nozzle 131B, the second nozzle 132B, the third nozzle 133B, the fourth nozzle 134B, and the fifth nozzle 134B are disposed in the second nozzle area 130B. A nozzle 135B is disposed. In this case, the distance P between each nozzle in the first nozzle area 120B and the distance P between each nozzle in the second nozzle area 130B are the row direction distance P between adjacent nozzles as described above. ) is the same as

After the nozzle unit 110B disposed as described above moves in the second direction and firstly ejects the conductive ink, as shown in FIG. d1), the conductive ink is secondarily ejected while moving in a direction opposite to the second direction. At this time, the movable range PO and the non-movable range PO and IPO in which the nozzle unit 110B can be shifted are determined based on the row direction distance P between adjacent nozzles.

Specifically, if the first distance d1 shifted by the fifth nozzle 125B in the first nozzle area 120B is smaller than or equal to P with respect to the fifth nozzle 125B, the fifth nozzle during primary injection By 125B, the fifth nozzle 125B is disposed at the same position as the position where the conductive ink is not disposed, and the missing line generated during the first jetting may not be filled by the second jetting.

In addition, if the first distance d1 shifted by the fifth nozzle 125B in the first nozzle area 120B is greater than or equal to 3P and less than or equal to 5P with respect to the fifth nozzle 125B, the first injection In this case, the fifth nozzle 125B is disposed at the same position as the position where the conductive ink is not disposed by the fifth nozzle 135B of the second nozzle area 130B, and the line generated during the first injection by the second injection is Missing parts may not be filled.

Accordingly, in the inkjet printing method according to an embodiment of the present invention, the first distance d1 at which the inkjet head is shifted may be expressed by Equation 1 below.

[Equation 1]

P<d1<(m-1)*P

Meanwhile, the first distance d1 may be optimized as in Equation 3 below.

[Equation 3]

d1=(m/2)*P

Specifically, the first distance d1 by which the inkjet head is shifted is preferably disposed between adjacent nozzles, and more preferably may be disposed in the middle between adjacent nozzles. Also, the first distance d1 is preferably set to correspond to a point corresponding to 1/2 of the width of the nozzle area. Accordingly, referring to (b) of FIG. 10 , when the first distance d1 shifted by the fourth nozzle 124B in the first nozzle area 120B is 2.5P, the fifth nozzle 125B is obtained by the equation While being disposed within the range of the first distance d1 proposed in 1, it may be disposed in the middle between nozzles adjacent to each other. Accordingly, the missing line portion generated during the first injection can be efficiently filled by the second injection.

Equations 1 and 3 were written on the assumption that the inkjet head moves in the positive direction by the first distance d1, but is not limited thereto and may move in the negative direction. In addition, as shown in (b) of FIG. 10, since the movable section PO and the movable section IPO are repeated in m units, the first distance d1 is also the number of repetitions of the movable section PO. It can be set variously according to .

In some embodiments, although not shown in the drawings, the wire may further include a portion extending in the second direction. As such, the portion extending in the second direction of the wiring is disposed in the same direction as the direction in which the head fixing unit 200 moves. Accordingly, even if a line break occurs at an arbitrary position of the wire, the wire itself is divided into a plurality of thin wires by the line break, so that the wire is composed of a plurality of thin wires extending in the second direction and parallel to each other. It is not disconnected. Accordingly, the wires extending in the second direction may be formed in the same process as either the first spraying of the conductive ink or the second spraying of the conductive ink.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and may be variously modified and implemented without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

1000: inkjet printing device
100: inkjet head
110, 110A, 110B: nozzle unit
120, 120A, 120B: first nozzle area
121, 121A, 121B: first nozzles in the first nozzle area
122, 122A, 122B: second nozzle in the first nozzle area
123, 123A, 123B: third nozzle in the first nozzle area
124, 124A, 124B: fourth nozzle in the first nozzle area
125B: fifth nozzle in the first nozzle area
130, 130A, 130B: second nozzle area
131, 131A, 131B: first nozzles in the second nozzle area
132, 132A, 132B: second nozzle in the second nozzle area
133, 133A, 133B: third nozzle in the second nozzle area
134, 134A, 134B: fourth nozzle in the second nozzle area
135B: fifth nozzle in the second nozzle area
200: head fixing part
300: head moving unit
400: stage
500: substrate
600A, 600B, 600C: Wiring
601A, 601B, 601C: one side of wiring
602A, 602B, 602C: other side of wiring
610: first ink pattern
620A, 620B, 620C: second ink pattern
630A, 630B, 630C: a plurality of first concave portions
640B, 640C: a plurality of second concave portions
L1: first line
L2: second line
L3: third line
L4: fourth line
PO: movable area
IPO: Unmovable Zone
d1: first distance

Claims (12)

An inkjet printing method for forming a wire extending in a first direction and having a first width using an inkjet head having a plurality of nozzles ejecting conductive ink, the method comprising:
firstly ejecting the conductive ink from a first line to a second line while moving the inkjet head in a second direction different from the first direction;
shifting the inkjet head by a first distance in the first direction; and
secondarily ejecting the conductive ink from a third line to a fourth line while moving the inkjet head in a direction opposite to the second direction;
The second line is located between the third line and the fourth line,
The inkjet printing method of claim 1 , wherein the distance between the first line and the second line is shorter than the first width. According to claim 1,
The first line and the fourth line are the same line,
The inkjet printing method of claim 1 , wherein a separation distance between the third line and the fourth line is equal to the first width. According to claim 1,
The fourth line is located between the first line and the second line,
The inkjet printing method of claim 1 , wherein a distance between the first line and the third line is equal to the first width. According to claim 1,
The first line and the second line are located between the third line and the fourth line,
The inkjet printing method of claim 1 , wherein a separation distance between the third line and the fourth line is equal to the first width. According to claim 1,
The plurality of nozzles of the inkjet head form a plurality of nozzle units repeated along the longitudinal direction of the inkjet head,
Each of the plurality of nozzle units,
a first nozzle region in which nozzles are sequentially disposed along an oblique direction in a row direction in odd-numbered rows; and
and a second nozzle area in which nozzles are sequentially disposed in an even-numbered row in a direction parallel to the oblique direction. According to claim 5,
Each of the plurality of nozzle units is composed of 2m (m is an integer of 3 or more) nozzles,
The number of nozzles disposed in each of the first nozzle area and the second nozzle area is m,
The step of shifting the inkjet head includes shifting the inkjet head by the first distance that satisfies Equation 1 below.
[Equation 1]
P<d1<(m-1)*P
(d1 is the first distance, P is the row direction distance between adjacent nozzles) According to claim 5,
Each of the plurality of nozzle units is composed of 2m (m is an integer of 3 or more) nozzles,
The number of nozzles disposed in each of the first nozzle area and the second nozzle area is m,
The step of shifting the inkjet head comprises shifting the inkjet head by the first distance that satisfies Equation 2 below when m is an even number and Equation 3 below when m is an odd number, Inkjet printing method.
[Equation 2]
d1=(m/2±0.5)*P
[Equation 3]
d1=(m/2)*P
(d1 is the first distance, P is the row direction distance between adjacent nozzles) According to claim 1,
The wiring further includes a portion extending in the second direction;
The inkjet printing method of claim 1 , wherein the portion of the wiring extending in the second direction is formed by the same process as one of firstly ejecting the conductive ink and secondarily ejecting the conductive ink. A wiring manufactured by an inkjet printing method using an inkjet head having a plurality of nozzles for ejecting conductive ink,
It includes a plurality of concave portions disposed on at least one side of one side of the wiring and the other side opposite to the one side,
Wherein the concave portion is periodically disposed for each side of at least one of one side and the other side of the wiring. According to claim 9,
wherein the concave portion is disposed only on one side of the wiring. According to claim 9,
The concave portion includes a plurality of first concave portions disposed on one side of the wiring and a plurality of second concave portions disposed on the other side of the wiring,
The plurality of first concave portions are arranged to correspond between the plurality of second concave portions. According to claim 9,
The concave portion includes a plurality of first concave portions disposed on one side of the wiring and a plurality of second concave portions disposed on the other side of the wiring,
The plurality of first concave portions and the plurality of second concave portions are arranged to correspond to each other.

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