JP2018094538A - Thin line pattern formation method and thin line pattern formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin line pattern formation method and a thin line pattern formation device capable of providing high productivity and forming the thin line pattern satisfactorily.SOLUTION: A thin line pattern formation method includes: a line state liquid formation process of relatively moving an inkjet head 410 and a substrate 1 by using the inkjet head 410 which ejects a droplet containing conductive material and forms a line state liquid of an even line width onto the substrate by coalescing droplets containing the conductive material; and a thin line pattern formation process of heating the substrate 1, blowing wind to the line state liquid by using a blowing means or performing sucking from the line state liquid side by using a sucking means, thereby, facilitating evaporation of the line state liquid, drying the line state liquid and forming a thin line pattern containing the conductive material. Therein, a wind speed S(m/s) of blowing by means of the blowing means and liquid amount L(pl) of the droplet ejected from one nozzle of droplets as one line of the line state liquid satisfy a relation of S≤0.0048 L+1.5.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fine line pattern forming method and a fine line pattern forming apparatus, and more particularly to a fine line pattern forming method and a fine line pattern forming apparatus capable of realizing high productivity and forming a fine line pattern satisfactorily.

  Conventionally, as a method of forming a fine line pattern containing a functional material, droplets containing a functional material are continuously applied to a substrate by an ink jet method, and the droplets are dried to obtain a solid content in the droplets. A method is known in which a functional material is deposited to form a finer pattern than droplets (Patent Document 1). According to this method, it is possible to form a pattern of several μm below the diameter of the droplet without requiring a special process.

  The present applicant uses a conductive material as a functional material, forms a thin line pattern (also referred to as “parallel line pattern”) made of the conductive material, dries the line liquid, It has been proposed to deposit a transparent electrode having a finer width than the line-shaped liquid by depositing it on both side edges of the line-shaped liquid (Patent Documents 2 and 3).

JP 2013-193222 A JP 2013-129089 A Japanese Patent Laid-Open No. 2015-012046

  However, the techniques of Patent Documents 2 and 3 have room for further improvement from the viewpoint of productivity. In particular, the determination of the conditions for drying the line-shaped liquid has been complicated. If the determination of the drying conditions is facilitated, the productivity of the fine line pattern can be improved.

  Accordingly, an object of the present invention is to provide a fine line pattern forming method and a fine line pattern forming apparatus capable of realizing high productivity and forming a fine line pattern satisfactorily.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

1.
Using an inkjet head that forms a pattern by discharging droplets containing a conductive material from a nozzle, the inkjet head and the substrate are moved relative to each other, and the droplets containing the conductive material are combined to form the base. A line-shaped liquid forming step for forming a line-shaped liquid having a uniform line width on the material;
A fine line pattern forming step of heating the base material and blowing the linear liquid using a blowing means to promote evaporation of the linear liquid and drying to form a fine line pattern containing the conductive material And
The air velocity S (m / s) of the air blown by the air blowing means and the liquid amount L (pl) of the liquid droplets ejected from one nozzle among the liquid droplets forming one line-like liquid have the following relationship. A fine line pattern forming method characterized by satisfying.
S ≦ 0.0048L + 1.5
2.
Using an inkjet head that forms a pattern by discharging droplets containing a conductive material from a nozzle, the inkjet head and the substrate are moved relative to each other, and the droplets containing the conductive material are combined to form the base. A line-shaped liquid forming step for forming a line-shaped liquid having a uniform line width on the material;
Fine line pattern formation in which the substrate is heated and sucked from the line-shaped liquid side using a suction means to promote evaporation of the line-shaped liquid and dry to form a thin line pattern containing the conductive material A process,
The wind speed S (m / s) of suction by the suction means and the liquid amount L (pl) of the liquid droplets ejected from one nozzle among the liquid droplets forming one line-like liquid have the following relationship. A fine line pattern forming method characterized by satisfying.
S ≦ 0.0048L + 1.5
3.
^3. The thin line pattern according to 1 or 2, wherein the replacement air volume V (m ³ / min) by the blowing means or the suction means and the liquid volume L (pl) of the droplet satisfy the following relationship: Forming method.
V ≧ 0.0094L
4).
4. The method for forming a fine line pattern according to 1, 2, or 3, wherein the air blowing or the suction is started after elapse of 10 msec to 1000 msec from the formation of the line liquid.
5.
5. The method for forming a fine line pattern according to 2, 3, or 4, wherein the wind speed of suction by the suction means is 4 m / sec or less.
6).
The air blowing means or the suction means is disposed at a position where the distance to the stage is 5 mm to 38 mm and the distance in the relative movement direction to the inkjet head is 15 mm to 50 mm. 6. The method for forming a fine line pattern according to any one of 5 above.
7).
7. The fine line pattern forming method according to any one of 1 to 6, wherein the relative movement between the inkjet head and the substrate is performed by moving the inkjet head.
8).
A forward path step of moving the ink jet head in the first direction and moving the air blowing means or the suction means to follow the ink jet head to form the line liquid and dry the line liquid. When,
When the ink jet head is moved in a second direction opposite to the first direction, the air blowing means or the suction means is moved to follow the ink jet head, thereby forming the line-shaped liquid and this 8. The thin line pattern forming method according to claim 7, further comprising a return path step of drying the line liquid.
9.
A forward path step of moving the ink jet head in the first direction and moving the air blowing means or the suction means to follow the ink jet head to form the line liquid and dry the line liquid. When,
A return path step of moving the blowing means or the suction means in a second direction opposite to the first direction to dry the line-shaped liquid formed in the forward path step. 8. The fine line pattern forming method according to 7.
10.
An ink jet head that discharges droplets containing a conductive material from a nozzle and unites the droplets containing the conductive material to form a line-shaped liquid on a substrate;
Heating means for heating the substrate;
A blowing means or a suction means for moving the air around the undried line-shaped liquid formed on the substrate to promote the evaporation of the line-shaped liquid;
The inkjet head and the blowing means or the suction means, and a movement operation means for performing a relative movement operation of the base material,
The air blowing means or the suction means is arranged at a position where the air around the undried line-shaped liquid formed by the ink jet head can be moved, and the distance from the ink jet head and the distance from the substrate are determined. A fine line pattern forming apparatus having a distance adjusting mechanism for adjustment.
11.
The movement operation means performs a reciprocal movement operation of the inkjet head and the air blowing means or the suction means and the base material,
The air blowing means or the suction means includes a front air blowing part or a front suction part located on the front side of the ink jet head and a rear side located on the rear side of the ink jet head in the relative movement direction of the ink jet head with respect to the base material When the inkjet head forms the line-shaped liquid, the front blowing unit or the front suction unit is stopped according to the relative movement direction of the inkjet head, and the rear blowing is performed. 11. The thin line pattern forming apparatus as described in 10 above, wherein only the part or the rear suction part is operated.

  ADVANTAGE OF THE INVENTION According to this invention, high productivity can be implement | achieved and the fine line pattern formation method and fine line pattern formation apparatus which can form a fine line pattern favorably can be provided.

The side view which illustrates notionally an example of the fine wire pattern formation apparatus of this invention FIG. 1 is a plan view of the fine line pattern forming apparatus shown in FIG. The top view explaining the function of the 1st ventilation part notionally A plan view showing measurement points of wind speed in the blower section The top view explaining notionally the function of the 2nd ventilation part Plan view for explaining the liquid volume L (pl) A plan view conceptually illustrating an example of a scanning thin line pattern forming apparatus FIG. 7 is a plan view for explaining a return path process in the fine line pattern forming apparatus shown in FIG. The top view explaining the process after the base material movement in the fine wire pattern formation apparatus shown in FIG. FIG. 7 is a plan view for explaining another example of the return path process in the fine line pattern forming apparatus shown in FIG. FIG. 7 is a plan view for explaining still another example of the return path process in the fine line pattern forming apparatus shown in FIG. The figure explaining an example of the formation method of an electroconductive thin wire The figure explaining the 1st aspect of mesh pattern formation The figure explaining the 2nd aspect of mesh pattern formation

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[Fine line pattern forming device]
FIG. 1 is a side view conceptually illustrating an example of the fine line pattern forming apparatus of the present invention, and FIG. 2 is a plan view thereof. This fine line pattern forming apparatus is an apparatus for executing the fine line pattern forming method of the present invention.

  1 and 2, 1 is a base material, 2 is a moving operation device serving as a moving operation means for conveying the base material 1, 4 is a line head, and 3 a and 3 b are air blowing means. It is the 1st and 2nd ventilation part which comprises. The first and second blowers 3a and 3b can perform not only blowing but also suction, and constitute suction means when performing suction.

  The movement operation device 2 performs relative movement operation of the line head 4 and each of the air blowing units 3a and 3b and the base material 1. In the illustrated example, the line head 4 and each of the air blowing units 3a and 3b are placed at predetermined positions. The belt moving operation device is configured to hold and move the base material 1. The moving operation device 2 includes a pair of transport rollers 21 and 22 and a transport belt 23 serving as a stage stretched over the pair of transport rollers 21 and 22. Reference numeral 24 denotes a motor for rotationally driving the transport roller 22.

  As will be described later, the moving operation device 2 is a device that operates both the line head 4 and each of the air blowing units 3a and 3b and the base material 1 to perform a relative moving operation (so-called “scanning method”). Good.

  As shown in FIGS. 1 and 2, the movement operation device 2 conveys the base material 1 placed on the conveyance belt 23 along a predetermined forward direction α and a reverse direction β opposite thereto. It is configured. Here, although the base material 1 has shown the case where it is a elongate base material drawn | fed out from a roll-shaped body not shown, it is not limited to this.

  On the conveyance path of the base material 1, the 2nd ventilation part 3b, the line head 4, and the 1st ventilation part 3a are provided along the forward direction (alpha). The line head 4 is provided on the downstream side in the forward direction from the second air blowing unit 3b, and the first air blowing unit 3a is provided on the downstream side in the forward direction from the line head 4.

  The line head 4 has a function of discharging a droplet containing a conductive material onto the substrate 1 to be conveyed and combining the plurality of droplets to form a line-shaped liquid.

  The line head 4 is configured by arranging a plurality of inkjet heads 410 in a direction intersecting with the conveyance directions α and β of the substrate 1. Each inkjet head 410 includes a plurality of nozzles (not shown in the drawing) arranged in a direction crossing the transport directions α and β of the base material 1, and ink including a conductive material is supplied from these nozzles. It is comprised so that discharge is possible on the base material 1. FIG.

  A generally known mechanism can be used as a mechanism for ejecting droplets from the inkjet head 410 constituting the line head 4, and the ink droplets are deformed by deforming the ink flow path by the vibration of the piezoelectric element. A piezo method that discharges ink, a thermal method that provides a heating element in the ink flow path, generates heat to generate bubbles, and discharges ink droplets in response to pressure changes in the ink flow path due to the bubbles, ink A preferable example is an electrostatic suction method in which ink in the flow path is charged and ink droplets are ejected by the electrostatic suction force of the ink. Note that in this specification, the expression “ink” may be used, but it refers to a liquid containing a functional material such as a conductive material.

  The line head 4 is configured so that droplets containing the functional material can be applied over a width corresponding to the width of the target pattern to be formed on the substrate 1 or a width larger than that. In addition, the width | variety here is the width | variety of the direction orthogonal to the conveyance directions (alpha) and (beta) of the base material 1. As shown in FIG. In the case where droplets containing a functional material can be applied over a width corresponding to the width of the target pattern by one ink jet head 410, only one ink jet head 410 is used instead of the line head 4. You may do it.

  The 1st and 2nd ventilation parts 3a and 3b have a function which moves the air around the undried line-shaped liquid formed on the base material 1 with the line head 4, and accelerates | stimulates evaporation of a line-shaped liquid. Here, a plurality of blowers 31 a and 31 b for blowing gas (for example, air) toward the surface of the base material 1 or sucking from the vicinity of the surface of the base material 1 are combined. The 1st and 2nd ventilation parts 3a and 3b constitute a blowing means when blowing the gas toward the surface of the substrate 1, and constitute a suction means when sucking the gas from the vicinity of the surface of the substrate 1. To do.

  The 1st and 2nd ventilation parts 3a and 3b are arrange | positioned in the position which can move the air around the undried line-shaped liquid which the line head 4 formed. As shown in FIG. 1, the first and second blowers 3a and 3b adjust the distance P from the line head 4 and the distance T from the conveyor belt 23 on which the base material 1 is placed. It has a mechanism.

  The air blowing units 3 a and 3 b constituting the air blowing means are located on the front air blowing unit located on the front side (upstream side) of the line head 4 in the relative movement direction and on the rear side (downstream side) of the line head 4 in the relative movement direction. It becomes a rear ventilation part. When the substrate 1 moves in the forward direction α with respect to the line head 4 to form a line-shaped liquid, the second air blowing unit 3b serving as the front air blowing unit is stopped and the first air blowing serving as the rear air blowing unit. Only the part 3a is activated. When the base material 1 moves in the reverse direction β with respect to the line head 4 to form a line-shaped liquid, the first air blowing unit 3a serving as the front air blowing unit is stopped and the second air blowing serving as the rear air blowing unit. Only the part 3b is activated.

  The thin line pattern forming apparatus includes a heating device 25 serving as a heating unit, and is configured to heat the substrate 1 conveyed by the conveyance belt 23. Thereby, in the 1st ventilation part 3a or the 2nd ventilation part 3b mentioned above, predetermined drying conditions can be formed rapidly. In the illustrated example, the heating device 25 is configured by a heater disposed below the transport belt 23 so that the substrate 1 can be heated from the back surface.

  In the present invention, “evaporation promotion” is different from drying of ink in general image formation using an inkjet head. In general image formation, it is preferable to quickly dry the ink on the recording medium, and relatively strong air blowing (or suction) is performed. On the other hand, the purpose of blowing (or suction) in the present invention is to assist the drying of the line-shaped liquid by heating the base material, to optimize the drying process, and to form a good fine line pattern, Fast drying is not the main purpose. Therefore, the air blowing (or suction) in the present invention is air (or suction) that is weak enough to achieve the above object.

[Fine line pattern forming method]
FIG. 3 is a plan view conceptually illustrating the function of the first blower 3a.

  As shown in FIG. 3, the line head 4 ejects ink containing a conductive material onto the substrate 1 transported in the forward direction α to form a plurality of first line-shaped liquids 5 (line Liquid forming step). The line-like liquid 5 is a uniform pattern with a line width containing a conductive material.

  In the present specification, the “line liquid” means an ink containing a conductive material applied in a line shape on the substrate 1. The length of the line liquid is preferably 5 times or more the line width of the line liquid, more preferably 10 times or more the line width of the line liquid. The line-shaped liquid is a precursor of a fine line pattern formed of a pair of fine lines parallel to each other to be formed later. The line-shaped liquid 5 can be formed by combining a plurality of droplets applied from the line head 4 onto the substrate 1 on the substrate 1.

  In a state where the base material 1 is heated by the heating device 25, the first air blowing unit 3 a blows air to promote evaporation of the line-like liquid 5 on the base material 1 conveyed in the forward direction α and dry it. (Thin line pattern forming step). In this drying process, the conductive material is selectively deposited on the edge of the line-shaped liquid 5 by the flow of the liquid inside the line-shaped liquid 5 due to the coffee stain phenomenon, and includes the conductive material along the first direction X. A first thin line pattern 6 is formed. Each fine line pattern 6 is composed of a pair of fine lines (hereinafter also referred to as line segments) 61 and 62 parallel to each other. The heating of the base material 1 by the heating device 25 may be always performed through both the line-shaped liquid forming process and the fine line pattern forming process, or may be performed only in the fine line pattern forming process.

  In the present specification, “thin line” means that the line width is at least thinner than the line width of the line-like liquid, and preferably refers to a line width of 10 μm or less.

Here, the wind speed S (m / s) of the air blown by the first blower 3a and the liquid amount L (pl) of the liquid droplets discharged from one nozzle among the liquid droplets that become one line-shaped liquid 5. Preferably satisfies the following relationship (hereinafter referred to as “S condition”).
S ≦ 0.0048L + 1.5

  FIG. 4 is a plan view showing measurement points of wind speed in the blower.

  Here, as shown in FIG. 4, the wind speed S (m / s) is the positions A, B, C, and D on the substrate 1 facing a plurality of locations (for example, 4 locations) on the peripheral edge of the first blower 3 a. It is the average value of the wind speed measured in. The same applies to the second blower 3b.

  The S condition can be satisfied by controlling the driving state (power consumption) of the first blower unit 3a according to the liquid amount L (pl).

  By drying with weak air that satisfies the S condition, drying can be promoted by diffusing the evaporated solvent without inhibiting the formation of the fine line pattern 6 due to the coffee stain phenomenon from the discharged line-like liquid 5, It is possible to form a thin line pattern 6 having good linearity and low resistance.

  FIG. 5 is a plan view conceptually illustrating the function of the second blower 3b.

  As shown in FIG. 5, the line head 4 ejects ink containing a conductive material onto the base material 1 conveyed in the reverse direction β to form a plurality of second line liquids 7 (line Liquid forming step). At this time, the second linear liquid 7 is formed so as to intersect with the already formed first fine line pattern 6.

  Therefore, the second direction Y is set to a direction that intersects the first direction X. The crossing angle is not particularly limited, but it is preferable to set the crossing angle at 90 ° as shown.

  Moreover, it is preferable that both the first direction X and the second direction Y are inclined with respect to the substrate transport directions α and β. In the illustrated example, the first direction X and the second direction Y The direction Y is inclined at 45 ° in opposite directions with respect to the conveyance directions α and β of the base material.

  In a state where the base material 1 is heated by the heating device 25, the second air blowing unit 3 b blows air to promote evaporation of the line-like liquid 7 on the base material 1 conveyed in the reverse direction β and dry it. (Thin line pattern forming step). In this drying process, the conductive material is selectively deposited on the edge of the line-shaped liquid 7 by the flow of the liquid inside the line-shaped liquid 7 due to the coffee stain phenomenon, and includes the conductive material along the second direction Y. A second fine line pattern 8 is formed. Each fine line pattern 8 includes a pair of line segments 81 and 82 that are parallel to each other.

  The second fine line pattern 8 formed by the line head 4 is formed so as to intersect with the already formed first fine line pattern 6. In this way, the mesh-like fine line pattern 9 is formed.

  As described above, the fine line pattern forming apparatus includes the second air blowing unit 3b, the line head 4, and the first air blowing unit 3a along the forward conveyance direction α of the base material 1 so that the substrate 1 is provided with the second air blowing unit 3b. A mesh-like fine line pattern 9 in which the fine line pattern 6 along the first direction X and the fine line pattern 8 along the second direction Y intersect can be formed.

As for the second air blowing section 3b, the air velocity S (m / s) and the liquid volume L (pl) of the air blowing preferably satisfy the following S conditions as described above.
S ≦ 0.0048L + 1.5

  The S condition can be satisfied by controlling the driving state (power consumption) of the second blower 3b according to the liquid amount L (pl).

Further, the replacement air volume V (m ³ / min) by the first and second air blowing sections 3a and 3b and the liquid volume L (pl) satisfy the following relationship (hereinafter referred to as “V condition”). Is preferred.
V ≧ 0.0094L

The replacement air volume V (m ³ / min) is calculated by multiplying the wind speed S (m / s) by the opening area (m ² ) of the plurality of blowers 31a. The same applies to the second blower 3b.

  The V condition can be satisfied by controlling the driving states (power consumption) of the first and second air blowing units 3a and 3b according to the liquid amount L (pl).

The inventor has the relationship between the air velocity S (m / s), the displacement air volume V (m ³ / min) and the liquid volume L (pl) of the air blown by the first and second air blowers 3a and 3b (S condition and For the V condition, an illustration was made as shown in Table 1 below.

  FIG. 6 is a plan view for explaining the liquid amount L (pl).

  As shown in FIG. 6, the liquid amount L (pl) is a liquid (2 drops in FIG. 6) discharged from one nozzle 411 among the liquid droplets that become one line-shaped liquid 5 or 7. Say quantity. Here, the line-like liquids 5 and 7 are formed in a direction (non-parallel direction) intersecting the transport directions α and β of the base material, as in the first and second directions X and Y.

  In Examples 1 to 4 and Comparative Examples 1 to 3, the liquid volume L is 630 pl. In Example 5 and Comparative Example 4, the liquid volume L is 300 pl. In Examples 6 to 8 and Comparative Example 5, the liquid amount L is 180 pl. In Examples 9 to 10 and Comparative Example 6, the liquid volume L is 120 pl. Each S condition and V condition are determined according to these liquid amounts L.

Here, as shown in FIG. 4, the wind speed S (m / s) is at positions A, B, C, and D on the substrate 1 facing a plurality of locations (four locations) on the peripheral edge of the first blower 3 a. It is the average value of the measured wind speed. The same applies to the second blower 3b. The replacement air volume V (m ³ / min) was calculated by multiplying the wind speed S (m / s) by the opening area (m ² ) of the plurality of blowers 31a. The same applies to the second blower 3b.

  Examples 1 to 10 satisfy the S condition (◯). Examples 1-3, 5-7, and 9-10 also satisfy V conditions ((circle)). Examples 4 and 8 do not satisfy the V condition (x).

  Comparative Examples 1 to 6 do not satisfy the S condition (x) and satisfy the V condition (◯).

  About the completed mesh-like thin wire | line pattern, Examples 1-10 were favorable ((circle)) about resistance value. Examples 1-3, 5-7, and 9-10 were favorable ((circle)) also about the transmittance | permeability and linearity. Examples 4 and 8 that did not satisfy the V condition were slightly inferior in transmittance and linearity (Δ).

  In Comparative Examples 1 to 6 that did not satisfy the S condition, the transmittance and linearity were poor (x). In Comparative Examples 1 and 4 having a large deviation from the S condition, the resistance value was also poor (x). Comparative Examples 2-3 and 5-6 were slightly inferior in resistance value (Δ).

[Other conditions for fine line pattern formation method]
In the thin line pattern forming method of the present invention, it is preferable to start blowing air after 10 msec to 1000 msec have elapsed since the formation of the line liquids 5 and 7. If the time from the formation of the line-like liquids 5 and 7 to the start of air blowing is less than 10 msec, the ink ejection performance from the line head 4 is affected and there is a possibility that good ejection cannot be performed. If the time from the formation of the line-shaped liquids 5 and 7 to the start of air blowing exceeds 1000 msec, the parallelism of the fine line pattern deteriorates and the resistance value may increase.

  In carrying out the thin line pattern forming method of the present invention, each of the air blowing units 3a and 3b of the air blowing means has a distance T to the conveying belt 23 on which the substrate 1 is placed set to 5 mm to 38 mm and is relative to the line head 4. The distance P in the moving direction (α, β) is preferably 15 mm to 50 mm. By setting the positions of the blowers 3a and 3b in this way, the S condition and the V condition can be easily satisfied, and a fine line pattern can be formed satisfactorily.

  In the thin line pattern forming method of each of the embodiments described above, suction is performed from the side of the line-shaped liquids 5 and 7 formed on the substrate 1 by the suction unit, and evaporation of the line-shaped liquids 5 and 7 is promoted and dried. It may be a thing. Also in this case, the same effect as the case where the blowing means is used as described above can be obtained. When using the suction means, the gas moving direction in the plurality of blowers 31a and 31b is reversed and used as a suction device (for example, in the case of a propeller fan, the rotation direction is reversed), and the first and second blowers are used. The parts 3a and 3b are operated as first and second suction parts. The first and second suction units constitute suction means. The same applies to the embodiments described later.

  When suction is performed from the side of the line-shaped liquids 5 and 7 by the suction means, the wind speed of suction by the suction means is preferably 4 m / sec or less. Since the warm air heated by the heating device can be efficiently used by suctioning from the line-like liquids 5 and 7 side, drying of the line-like liquids 5 and 7 can be further promoted.

[Scan type fine line pattern forming device]
The fine line pattern forming apparatus of the present invention can be configured as a thin line pattern forming apparatus of a scanning method in which both the line head 4 and each of the air blowing units 3a and 3b and the base material 1 are moved and moved relative to each other.

  FIG. 7 is a plan view conceptually illustrating an example of a scanning thin line pattern forming apparatus.

  As shown in FIG. 7, the thin line pattern forming apparatus is configured to move the line head 4 and the air blowing unit in the forward direction α in a state where the base material 1 is stopped. Formation (line-shaped liquid formation process) and drying (line-line pattern formation process) of this line-shaped liquid 5 are performed, and the 1st thin line pattern 6 is formed. In this forward path process, only the second air blower 31b that is the rear air blower following the line head 4 is operated. The formation process and conditions of the first fine line pattern 6 are the same as those described above with reference to FIG.

  FIG. 8 is a plan view for explaining a return path process in the fine line pattern forming apparatus shown in FIG.

  Next, as shown in FIG. 8, the fine line pattern forming apparatus has a second line shape in a return path process in which the line head 4 and the blowing unit are moved in the reverse direction β while the base material 1 is stopped. Formation of the liquid 7 (line-shaped liquid forming process) and drying of the line-shaped liquid 7 (thin line pattern forming process) are performed to form the second thin line pattern 8. In this return path process, only the 1st ventilation part 31a used as the back ventilation part which follows the line head 4 is operated. The formation process and conditions of the second fine line pattern 8 are the same as those described above with reference to FIG.

  The second fine line pattern 8 formed by the line head 4 is formed so as to intersect with the already formed first fine line pattern 6. In this way, the mesh-like fine line pattern 9 is formed.

  FIG. 9 is a plan view for explaining a process after moving the base material in the fine line pattern forming apparatus shown in FIG.

  Next, as shown in FIG. 9, the fine line pattern forming apparatus moves the base material 1 to a predetermined distance (of the line head 4) in the base material feed direction Z orthogonal to the moving direction αβ (main scanning direction) of the line head 4. Move the print width). The line head 4 and the air blowing unit are operated to move relative to the base material 1 in the sub-scanning direction −Z facing the base material feeding direction Z.

  Next, this thin line pattern forming apparatus forms the first thin line pattern 6 by the return path process and the second thin line pattern 8 by the forward path process in the state where the base material 1 is stopped as described above. Thus, a mesh-like fine line pattern 9 is formed.

  The mesh-like fine line pattern 9 is connected to the mesh-like fine line pattern 9 formed before moving the base material 1 at the side edge portion, and constitutes a continuous mesh-like fine line pattern 9. In this way, a continuous mesh-like fine line pattern 9 can be formed over the entire surface of the substrate 1 regardless of the size of the substrate 1.

  FIG. 10 is a plan view for explaining another example of the return path step in the fine line pattern forming apparatus shown in FIG.

  In the case where a desired fine line pattern can be formed only by the forward process of moving the line head 4 and the air blowing means in the forward direction α, for example, in the case where only the first fine line pattern 6 is formed on the substrate 1, FIG. As shown in FIG. 5, after the forward path process, the base material 1 is moved in the base material feed direction Z by a predetermined distance (printing width of the line head 4). And the 1st fine wire pattern 6 is formed by an outward path | route process in the state which stopped the base material 1. FIG. Also in this case, in the forward path process, only the second air blowing section 31b that becomes the rear air blowing section that follows the line head 4 is operated, and in the return path process, the first air blowing section that follows the line head 4 becomes the first air blowing section. Only the air blowing section 31a is operated.

  The fine line pattern 6 is connected to the fine line pattern 6 formed before moving the base material 1 at the side edge portion to constitute a continuous fine line pattern 6. In this way, the continuous thin line pattern 6 can be formed over the entire surface of the substrate 1 regardless of the size of the substrate 1.

  FIG. 11 is a plan view for explaining still another example of the return path process in the fine line pattern forming apparatus shown in FIG.

  In this thin line pattern forming apparatus, when the drying of the line-shaped liquid is insufficient only by the forward process in which the line head 4 and the air blowing means are moved in the forward direction α, as shown in FIG. The line-shaped liquid may be formed and dried, and only the line-shaped liquid may be dried in the forward process. In this case, in the forward path process, only the second air blowing part 31b that is the rear air blowing part following the line head 4 is operated, and in the return path process, both the first and second air blowing parts 31a and 31b are operated. Is activated.

  Thus, by blowing air to the same line-shaped liquid in both the forward path process and the return path process, the line-shaped liquid can be dried under favorable conditions, and a fine line pattern can be formed satisfactorily.

[Coffee stain phenomenon]
In the present invention, when the line-shaped liquid provided on the substrate is dried, a fine line pattern can be formed by utilizing the coffee stain phenomenon to form a conductive thin line. This will be described with reference to FIG.

  First, as shown in FIG. 12A, a line-like liquid 5 made of ink containing a conductive material is applied on the substrate 1. Next, as shown in FIG. 12B, conductive thin wires 61 and 62 can be formed by selectively depositing a conductive material on the edge of the line liquid 5 in the process of drying the line liquid 5. it can. In this example, a pair of conductive thin wires 61 and 62 are formed by selectively depositing a conductive material on both edges along the longitudinal direction of the line-shaped liquid 5. By forming the line width of the line-like liquid 5 uniformly, the pair of conductive thin wires 61 and 62 can be formed in parallel to each other.

  The line widths of the conductive thin wires 61 and 62 are narrower than the line width of the line-like liquid 5 and can be set to, for example, 20 μm or less, 15 μm or less, and further 10 μm or less. The lower limit of the line width of the conductive thin wires 61 and 62 is not particularly limited, but can be set to, for example, 1 μm or more from the viewpoint of providing stable conductivity.

  Various patterns can be formed by one or a plurality of conductive thin wires 61 and 62. Examples of such a pattern include a stripe pattern and a mesh pattern. Hereinafter, the first mode of mesh pattern formation will be described with reference to FIG. 13, and then the second mode of mesh pattern formation will be described with reference to FIG.

[First Mode of Mesh Pattern Formation]
In the first mode of forming a mesh pattern, first, as shown in FIG. 13A, a plurality of line-shaped liquids 5 arranged in parallel at a predetermined interval are formed on the substrate 1.

  Next, as shown in FIG. 13B, a pair of conductive thin wires 61 and 62 are formed from each line-shaped liquid 5 by utilizing the coffee stain phenomenon when the line-shaped liquid 5 is dried.

  Next, as shown in FIG. 13C, a plurality of line-like liquids 7 arranged in parallel at predetermined intervals so as to intersect with the plurality of conductive thin wires 61 and 62 previously formed are formed.

  Next, as shown in FIG. 13D, a pair of conductive thin wires 81 and 82 are formed from each line-shaped liquid by utilizing the coffee stain phenomenon when the line-shaped liquid 7 is dried. A mesh pattern can be formed as described above.

  In the example of FIG. 13, the line-like liquids 5 and 7 and the conductive thin wires 61, 62, 81, and 82 are straight lines, but the present invention is not limited to this. The shapes of the line-like liquids 5 and 7 and the conductive thin wires 61, 62, 81 and 82 may be, for example, wavy lines or broken lines.

[Second Mode of Mesh Pattern Formation]
In the second mode of forming the mesh pattern, first, as shown in FIG. 14A, the longitudinal direction (vertical direction in the figure) and the width direction (horizontal direction in the figure) of the base material 1 are formed on the base material 1. The line-shaped liquid 5 having a plurality of quadrangles arranged in parallel at a predetermined interval is formed.

  Next, as shown in FIG. 14B, a thin line unit composed of a pair of conductive thin wires 61 and 62 is formed from each line-shaped liquid 5 by utilizing the coffee stain phenomenon when the line-shaped liquid 5 is dried. Form. In such a thin wire unit, the conductive thin wires 61 and 62 are formed concentrically, with one (outside conductive thin wire 61) including the other (inside conductive thin wire 62) inside. In addition, the conductive thin wires 61 and 62 each have a quadrangular shape corresponding to the shape of both edges (inner peripheral edge and outer peripheral edge) of the line-shaped liquid 5.

  Next, as shown in FIG. 14 (c), a line-shaped liquid 7 having a plurality of quadrangles arranged side by side in the longitudinal direction and the width direction of the substrate 1 is formed on the substrate 1. Here, the line-shaped liquid 7 which comprises a some square is formed in the position pinched | interposed between the thin line units formed previously. Here, the line-shaped liquid 7 having a quadrangular shape is arranged so as to come into contact with the outer conductive thin wire 61 in the thin wire units adjacent to the quadrilateral liquid unit, but not into the inner conductive thin wire 62.

  Next, as shown in FIG. 14 (d), a thin line unit composed of a pair of conductive thin wires 81, 82 is formed from each line-shaped liquid 7 by utilizing the coffee stain phenomenon when the line-shaped liquid 7 is dried. Further form.

  In the pattern shown in FIG. 14D, the outer conductive thin wires 81 are connected to the adjacent outer conductive thin wires 61. On the other hand, the inner conductive thin wire 82 is not connected to the other inner conductive thin wire 62 and the outer conductive thin wire 61. That is, the inner conductive thin wires 62 and 82 are disposed so as to be isolated.

  The pattern shown in FIG. 14D may be used as a mesh pattern as it is. Further, the inner conductive thin wires 62 and 82 in the pattern shown in FIG. 14D may be removed to form a mesh pattern (FIG. 14E) composed of the outer conductive thin wires 61 and 81.

  The method of removing the inner conductive thin wires 62 and 82 is not particularly limited, and for example, a method of irradiating energy rays such as laser light or a method of chemically etching can be used.

  Further, when electrolytic plating is performed on the outer conductive thin wires 61 and 81, a method of removing the inner conductive thin wires 62 and 82 with a plating solution may be used. As described above, the inner conductive thin wires 62 and 82 are disposed so as to be isolated from each other, and can be excluded from the energization path for performing electrolytic plating on the outer conductive thin wires 61 and 81. Therefore, while the outer conductive thin wires 61 and 81 are subjected to electrolytic plating (while energized), the inner conductive thin wires 62 and 82 not subjected to electrolytic plating are dissolved or decomposed by a plating solution. Can be removed.

  In the example of FIG. 14, the line-shaped liquids 5 and 7 and the conductive thin wires 61, 62, 81, and 82 are rectangular, but the present invention is not limited to this. Examples of the shapes of the line-shaped liquids 5 and 7 and the conductive thin wires 61, 62, 81, and 82 include closed geometric figures. Examples of the closed geometric figure include polygons such as a triangle, a quadrangle, a hexagon, and an octagon. In addition, the closed geometric figure may include a curved element such as a circle or an ellipse.

〔Base material〕
Examples of the substrate 1 include a transparent substrate. The degree of transparency of the transparent substrate is not particularly limited, and the light transmittance may be anywhere from several% to several tens%, and the spectral transmittance may be any. These light transmittance and spectral transmittance can be appropriately determined according to the application and purpose.

  The material of the base material 1 is not particularly limited, and for example, glass, synthetic resin material, and other various materials can be used. Synthetic resin materials include, for example, polyethylene terephthalate (PET) resin, polyethylene naphthalate (PEN) resin, polybutylene terephthalate resin, cellulose resin (polyacetylcellulose, cellulose diacetate, cellulose triacetate, etc.), polyethylene resin, polypropylene Resin, methacrylic resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile- (poly) styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, poly ( Examples include (meth) acrylic resins, polycarbonate resins, polyester resins, polyimide resins, polyamide resins, and polyamideimide resins. If these materials are used, good transparency can be imparted to the substrate.

  The shape of the substrate 1 is not particularly limited, and can be, for example, a plate shape (plate material). In the case of a plate material, the thickness, size (area) and shape are not particularly limited, and can be appropriately determined according to the use and purpose of the transparent conductive film. The thickness of the plate material is not particularly limited, and can be, for example, about 1 μm to 10 cm, and further about 20 μm to 300 μm.

  Further, the base material may be subjected to a surface treatment for changing the surface energy. Furthermore, you may provide a hard-coat layer, an antireflection layer, etc. in a base material.

〔ink〕
Next, the ink suitably used for the above-described coffee stain phenomenon will be described in detail. The conductive material contained in the ink is not particularly limited, and examples thereof include conductive fine particles and a conductive polymer.

  Examples of the conductive fine particles include metal fine particles and carbon fine particles. Examples of the metal constituting the metal fine particle include Au, Pt, Ag, Cu, Ni, Cr, Rh, Pd, Zn, Co, Mo, Ru, W, Os, Ir, Fe, Mn, Ge, Sn, Ga, In etc. are mentioned. Among these, Au, Ag, and Cu are preferable, and Ag is particularly preferable. The average particle diameter of the metal fine particles can be set to, for example, 1 to 100 nm, and further 3 to 50 nm. The average particle diameter is a volume average particle diameter, and can be measured by “Zeta Sizer 1000HS” manufactured by Malvern. Examples of the carbon fine particles include graphite fine particles, carbon nanotubes, fullerenes and the like.

  Although it does not specifically limit as a conductive polymer, (pi) conjugated system conductive polymer can be mentioned preferably. Examples of the π-conjugated conductive polymer include polythiophenes and polyanilines. The π-conjugated conductive polymer may be used together with a polyanion such as polystyrene sulfonic acid.

  The concentration of the conductive material in the ink can be, for example, 5% by weight or less, and can be 0.01% by weight or more and 1.0% by weight or less. As a result, the coffee stain phenomenon is promoted, and effects such as further narrowing of the conductive thin wire can be obtained.

  The solvent used for the ink is not particularly limited, and may include one or more selected from water and organic solvents. Examples of the organic solvent include 1,2-hexanediol, 2-methyl-2,4-pentanediol, 1,3-butanediol, 1,4-butanediol, alcohols such as propylene glycol, diethylene glycol monomethyl ether, Examples include ethers such as diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether.

  The ink may contain other components such as a surfactant. The surfactant is not particularly limited, and examples thereof include a silicon surfactant. The concentration of the surfactant in the ink can be, for example, 1% by weight or less.

[Post-processing]
A post-treatment can be applied to the conductive fine wire formed on the substrate 1. Examples of the post treatment include firing treatment and plating treatment. After performing the baking treatment, a plating treatment may be performed.

  Examples of the firing treatment include light irradiation treatment and heat treatment. For the light irradiation treatment, for example, gamma rays, X-rays, ultraviolet rays, visible light, infrared rays (IR), microwaves, radio waves, and the like can be used. For the heat treatment, for example, hot air, a heating stage, a heating press, or the like can be used.

  Examples of the plating treatment include electroless plating and electrolytic plating. In the electrolytic plating, the conductive thin wire can be selectively plated using the conductivity of the conductive thin wire. The conductive thin wire may be subjected to a plurality of plating processes. A plurality of times of plating processes using different plating metals may be performed. A plurality of metal layers can be laminated on the conductive thin wire by a plurality of plating processes. When laminating a plurality of metal layers, by laminating the first metal layer made of copper and the second metal layer made of nickel or chromium in this order on the conductive fine wire, The effect of improving weather resistance by chromium and the effect of eliminating the color can be obtained. In addition, the plating solution used for electrolytic plating may contain an oxidizing agent such as sodium persulfate, cupric chloride, hydrogen peroxide, and the like. By using the oxidant, the conductivity of the conductive fine wire can be improved and the plating thickness can be suppressed. This effect is exhibited particularly well when a conductive thin wire formed using the coffee stain phenomenon is targeted.

[Use]
Applications of the transparent conductive film and the substrate with the transparent conductive film are not particularly limited, and can be used for various devices provided in various electronic devices, for example. Here, “transparent” does not mean that the conductive thin wire itself constituting the transparent conductive film is transparent, but the transparent conductive film as a whole (for example, a region where the conductive thin wire is not provided). As long as it can transmit light.

  The conductive thin wire constituting the transparent conductive film can be used as, for example, electric wiring constituting an electric circuit.

  For example, a transparent conductive film can be used as one transparent electrode (planar electrode). The transparent electrode can be used as a transparent electrode for various types of displays such as liquid crystal, plasma, organic electroluminescence, and field emission. Moreover, a transparent electrode can be used as transparent electrodes, such as a touch panel, a mobile phone, electronic paper, various solar cells, various electroluminescent light control elements, for example. In particular, the transparent electrode can be used for a touch panel sensor of an electronic device such as a smartphone or a tablet terminal. When used as a touch panel sensor, a transparent electrode can be used as a position detection electrode (X electrode and Y electrode).

1: Substrate 2: Moving operation device 3a: First blower (suction unit)
3b: 2nd ventilation part (suction part)
4: Line head 410: Inkjet head 5: First line-shaped liquid 6: First fine line pattern 61, 62: Fine line 7: Second line-shaped liquid 8: Second fine line pattern 81, 82: Fine line 9: Mesh-like fine line pattern

Claims (11)

Using an inkjet head that forms a pattern by discharging droplets containing a conductive material from a nozzle, the inkjet head and the substrate are moved relative to each other, and the droplets containing the conductive material are combined to form the base. A line-shaped liquid forming step for forming a line-shaped liquid having a uniform line width on the material;
A fine line pattern forming step of heating the base material and blowing the linear liquid using a blowing means to promote evaporation of the linear liquid and drying to form a fine line pattern containing the conductive material And
The air velocity S (m / s) of the air blown by the air blowing means and the liquid amount L (pl) of the liquid droplets ejected from one nozzle among the liquid droplets forming one line-like liquid have the following relationship. A fine line pattern forming method characterized by satisfying.
S ≦ 0.0048L + 1.5 Using an inkjet head that forms a pattern by discharging droplets containing a conductive material from a nozzle, the inkjet head and the substrate are moved relative to each other, and the droplets containing the conductive material are combined to form the base. A line-shaped liquid forming step for forming a line-shaped liquid having a uniform line width on the material;
Fine line pattern formation in which the substrate is heated and sucked from the line-shaped liquid side using a suction means to promote evaporation of the line-shaped liquid and dry to form a thin line pattern containing the conductive material A process,
The wind speed S (m / s) of suction by the suction means and the liquid amount L (pl) of the liquid droplets ejected from one nozzle among the liquid droplets forming one line-like liquid have the following relationship. A fine line pattern forming method characterized by satisfying.
S ≦ 0.0048L + 1.5 The thin line according to claim 1 or 2, wherein the replacement air volume V (m ³ / min) by the air blowing means or the suction means and the liquid volume L (pl) of the droplet satisfy the following relationship. Pattern forming method.
V ≧ 0.0094L   4. The fine line pattern forming method according to claim 1, wherein the air blowing or the suction is started after elapse of 10 msec to 1000 msec from the formation of the line liquid.   The fine line pattern forming method according to claim 2, 3 or 4, wherein a wind speed of suction by the suction means is 4 m / sec or less.   2. The air blowing means or the suction means is arranged at a position where the distance to the stage is 5 mm to 38 mm and the distance in the relative movement direction to the inkjet head is 15 mm to 50 mm. The thin line pattern formation method in any one of -5.   The thin line pattern forming method according to claim 1, wherein the relative movement between the inkjet head and the substrate is performed by moving the inkjet head. A forward path step of moving the ink jet head in the first direction and moving the air blowing means or the suction means to follow the ink jet head to form the line liquid and dry the line liquid. When,
When the ink jet head is moved in a second direction opposite to the first direction, the air blowing means or the suction means is moved to follow the ink jet head, thereby forming the line-shaped liquid and this A thin line pattern forming method according to claim 7, further comprising a return path step of drying the line liquid. A forward path step of moving the ink jet head in the first direction and moving the air blowing means or the suction means to follow the ink jet head to form the line liquid and dry the line liquid. When,
A return path step of moving the blowing means or the suction means in a second direction opposite to the first direction to dry the line-shaped liquid formed in the forward path step. Item 8. The fine line pattern forming method according to Item 7. An ink jet head that discharges droplets containing a conductive material from a nozzle and unites the droplets containing the conductive material to form a line-shaped liquid on a substrate;
Heating means for heating the substrate;
A blowing means or a suction means for moving the air around the undried line-shaped liquid formed on the substrate to promote the evaporation of the line-shaped liquid;
The inkjet head and the blowing means or the suction means, and a movement operation means for performing a relative movement operation of the base material,
The air blowing means or the suction means is arranged at a position where the air around the undried line-shaped liquid formed by the ink jet head can be moved, and the distance from the ink jet head and the distance from the substrate are determined. A fine line pattern forming apparatus having a distance adjusting mechanism for adjustment. The movement operation means performs a reciprocal movement operation of the inkjet head and the air blowing means or the suction means and the base material,
The air blowing means or the suction means includes a front air blowing part or a front suction part located on the front side of the ink jet head and a rear side located on the rear side of the ink jet head with respect to the relative movement direction of the ink jet head with respect to the substrate. When the inkjet head forms the line-shaped liquid, the front blowing unit or the front suction unit is stopped according to the relative movement direction of the inkjet head, and the rear blowing is performed. The thin line pattern forming apparatus according to claim 10, wherein only the part or the rear suction part is operated.

Images