EP2851129A1

EP2851129A1 - Spray nozzle and coating system using the same

Info

Publication number: EP2851129A1
Application number: EP14162012.0A
Authority: EP
Inventors: Do-Young Byun; Vu Dat Nguyen; Baek Hoon Seong
Original assignee: Enjet Co Ltd
Current assignee: Enjet Co Ltd
Priority date: 2013-03-28
Filing date: 2014-03-27
Publication date: 2015-03-25
Also published as: TWI523696B; CN104069968A; CN104069968B; TW201436874A; JP2014193462A

Abstract

Provided herein is a spray nozzle and a coating system using the same, comprising: a liquid nozzle injecting liquid towards a substrate; a gas nozzle for injecting gas to collide with the liquid on an injection path of the liquid to perform a primary atomization of the liquid; and a voltage supply connected to the liquid nozzle, the voltage supply for applying voltage to the liquid nozzle to generate an electric field between the liquid nozzle and substrate to perform a secondary atomization of the liquid.

Description

This application claims the benefit of priority under 35 U.S.C. § 119(a) of Korean Patent Applications No. 10-2013-0033536 and No. 10-2013-0110716 , filed on March 28, 2013 and September 13, 2013, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

1. Field

The following description relates to a spray nozzle and a coating system using the same, and more particularly, to a spray nozzle that is capable of atomizing an injection liquid and stably injecting fine droplets of a uniform size, and increasing the amount of injection so that it can be applied to mass production processes, and a coating system thereof.

2. Description of Related Art

A coating process is essential in not only traditional industrial areas such as automobile and construction, but also in manufacturing areas such as display and solar cell etc. Especially, when manufacturing displays such as organic solar cells and organic light emitting diodes (OLED) etc., there is required a precise coating of a thickness of tens to hundreds nanometers. In addition, since the roughness and uniformity of a coating surface have a significant effect on the performance of a product, it should be possible to use ultrafine droplets, and to coat the product quickly for mass production.
Recently, as application of touch screens increases, anti-fingerprint coating or anti-reflecting coating method for application on the surfaces of touch window surfaces such as smart phones, tablets, notebook computers etc. are being converted into wet coating processes instead of conventional vacuum coating processes.
The technology of atomizing liquid for conventional spray coating processes may be broadly classified into methods using pressure energy, gas energy, centrifugal energy, mechanical energy, and electrical energy.
Herein, the method of using pressure energy is a method of using pressure injection valves, wherein the liquid to be atomized is passed through single hole or porous injection nozzles, or vortex injection valves(simplex, duplex, dual orifice, and reflux types etc.) to form spray. This is a method generally used to spray liquid fuel injected into a gas turbine burner, randomly creating droplets of approximately 20∼250µm. Therefore, in such a method of using pressure energy, there is a problem that it is difficult to be applied to a complicated coating technology.
In addition, the method that uses centrifugal energy utilizing a wheel atomizer or rotary cup atomizer is a method of randomly creating droplets of a range of 10∼200µm. It is a method mainly used in cleaning and agriculture areas. In this method, it is impossible to coat the central portion, and thus there is a problem that it is difficult to be applied to a uniform coating technology.
Meanwhile, there is a gas bombardment atomizer method which is method of using gas energy, wherein a great quantity of gas in a low speed and low pressure state is injected towards a jet of liquid that is being injected using a two-fluid injection valve to atomize the liquid, and a gas assisted atomizer method wherein a small amount of gas in a high speed state is injected towards a liquid jet. This method is mainly used in thin film wet coating, but in this method, the droplets would be formed to have a random size between 15∼200µm, thus making it difficult to form a fine thin film coating, and stains may occur on the coating surface, and further, due to the high fluid speed when injecting the gas at a high speed, the fast fluid speed may make the atomized droplets collide with the substrate, causing the droplets to bounce back. In addition, there may be too much coating liquid coming off the substrate, causing a waste of the coating liquid, thereby increasing manufacturing costs, and since the viscosity of the liquid that can be used is limited to less than 50cp, there may be limitations in the coating technology in developing or applying functional materials, causing difficulty in developing various types of coating technologies.
Furthermore, the most representative method of using mechanical energy is the ultrasound spray technology wherein liquid is atomized by high frequency signals applied by a piezoelectric actuator. In this method, droplets may be further atomized than when using gas energy, but droplets are formed to have a random size between 1∼200µm, making it difficult to secure uniformity in the size of droplets, and there is also a limitation in the amount of injection of droplets, thereby causing a problem of difficulty in utilizing in mass production processes.
Meanwhile, as a method of using electrical energy, there is the electrospray method wherein droplets are drawn towards a strong electric field and then atomized. An advantage of this method is that it is possible to produce fine and uniform droplets having a size range of hundreds nm to 5 µm. However, there are limitations that there needs to be at least 10^-4 S/m of electrical conductivity, and that the amount of liquid sprayed is limited to 10^-10 to 10^-9m³/sec, thereby making it difficult to be applied to mass product processes.

SUMMARY

Therefore, the purpose of the present disclosure is to resolve the aforementioned problems of prior art, that is, to provide a spray nozzle that is capable of stably injecting fine droplets having a uniform size, whereby it is possible to increase the amount of injection so that it may be applied to mass production processes, and a coating system thereof.
In a general aspect, there is provided a spray nozzle comprising: a liquid nozzle injecting liquid towards a substrate; a gas nozzle for injecting gas to collide with the liquid on an injection path of the liquid to perform a primary atomization of the liquid; and a voltage supply connected to the liquid nozzle, the voltage supply for applying voltage to the liquid nozzle to generate an electric field between the liquid nozzle and substrate to perform a secondary atomization of the liquid, it is desirable that the support is made of conductive material.
In the general aspect of the spray nozzle, it is desirable that the the spray nozzle further comprises a case for accommodating the liquid nozzle inside thereof, and the liquid and gas are made to collide with each other outside the case.
In the general aspect of the spray nozzle, it is desirable that the spray nozzle further comprises a case for accommodating the liquid nozzle and gas nozzle inside thereof, the case provided with a gas path for guiding a flowing direction of the gas so that the gas being injected from the gas nozzle collides with the liquid on the injection path of the liquid, and the gas is made to collide with the liquid inside the case.
In the general aspect of the spray nozzle, it is desirable that the case is provided with a guide part that is dented towards the inside on an end closer to the substrate, a cross-sectional area of the guide increasing as it gets farther from the substrate, in order to guide an injection direction of the liquid so that the liquid is injected towards the substrate.
In the general aspect of the spray nozzle, it is desirable that a distance between the guide part and the substrate is 1cm or more so that a secondary atomization of the liquid can be completed between the guide part and the substrate.
In the general aspect of the spray nozzle, it is desirable that a flow rate of the liquid supplied to the liquid nozzle is 10^-8m³/s or more.
In the general aspect of the spray nozzle, it is desirable that the liquid nozzle consists of a plurality of liquid nozzles each having a different diameter, any one of the plurality of liquid nozzles accommodating another of the plurality of liquid nozzles inside thereof or any one of the plurality of liquid nozzles accommodated inside of another of the plurality of liquid nozzles.
In the general aspect of the spray nozzle, it is desirable that the liquid nozzle consists of a plurality of liquid nozzles, any one of the plurality of liquid nozzles being distanced from another of the plurality of liquid nozzles in a parallel direction.
In the general aspect of the spray nozzle, it is desirable that the gas path guides the flowing direction of the gas so that the gas being injected from the gas nozzle collides with the liquid on the injection path of the liquid.
In a general aspect, there is provided a coating system using a spray nozzle, the coating system comprising: a support where a substrate is disposed; a spray nozzle injecting liquid towards a surface of the substrate according to any one of claims 1 to 9; a liquid supply supplying liquid being injected from the liquid nozzle; a gas supply supplying gas flowing inside the gas path; and a transferrer transferring at least one of the support and the spray nozzle.
In the general aspect of the coating system, it is desirable that the coating system further comprises a plasma processor configured to plasma process the substrate; and the spray nozzle is provided with a substrate plasma processed through the plasma processor.
In the general aspect of the coating system, it is desirable that the plasma processor cleans a surface of the substrate, or processes the surface of the substrate to be hydrophilic or hydrophobic depending on the liquid injected from the spray nozzle.
In the general aspect of the coating system, it is desirable that the plasma processor performs at least one of charging and discharging the substrate, and the spray nozzle is spaced by 500mm or less from the plasma processor along a transferring path of the substrate.
In the general aspect of the coating system, it is desirable that the transferrer comprises a first transferrer configured to transfer the support; and a second transferrer configured to move the spray nozzle in a direction approaching or distancing from the support.
In the general aspect of the coating system, it is desirable that the coating system further comprises a sensor configured to obtain location information of the support; and a controller configured to receive the location information of the support through the sensor and control operations of at least one of the plasma processor, spray nozzle, voltage applier and transferrer.
In the general aspect of the coating system, it is desirable that the controller comprises: an electric field control module configured to control an intensity of an electric field formed between the spray nozzle and the support by adjusting a voltage amount applied to the spray nozzle; a pressure control module configured to control a pressure of the gas that collides with the liquid in the spray nozzle; a transfer control module configured to control a movement of the transferrer; and a flow rate control module configured to control a flow rate of the liquid injected form the spray nozzle.
In the general aspect of the coating system, it is desirable that the coating system further comprises an amperometer connecting the spray nozzle and the substrate, and measuring current information between the spray nozzle and the substrate; and the controller further comprises a current amount control module receiving current information obtained by the amperometer and controls a current amount between the substrate and the spray nozzle.
In the general aspect of the coating system, it is desirable that the coating system further comprises a test substrate to which liquid being injected from the spray nozzle is shot, the test substrate testing a injection state of the spray nozzle through current information of the liquid shot, and the amperometer is connected between the liquid nozzle and the test substrate and measures the current information of the shot liquid.
In the general aspect of the coating system, it is desirable that the support is made of conductive material or provided with a coating layer of non-conductive material on an external surface thereof.
In the general aspect of the coating system, it is desirable that the support receives voltage or is grounded selectively depending on its location.
In the general aspect of the coating system, it is desirable that the coating system further comprises a container accommodating a spray nozzle inside thereof, the container comprising an inlet and outlet for entering/exiting of the substrate.
In the general aspect of the coating system, it is desirable that the container is provided with a gas channel for injecting nitrogen or inert gas inside thereof or discharging the nitrogen or inert gas.
In the general aspect of the coating system, it is desirable that at least one of a certain gas concentration, temperature and humidity is maintained inside the container.
According to the present disclosure, there is provided a spray nozzle that may atomize liquid being injected in a uniform size, and a coating system thereof.
In addition, it is possible to increase the sprayed capacity so as to be applied to mass production processes.
In addition, it is possible to atomize and inject liquid regardless of whether the material has a low electrical conductivity or it is a non-polar material.
In addition, it is possible to guide the liquid being injected towards the substrate, thereby improving the amount of material consumption.
In addition, it is possible to stably inject liquid regardless of whether or not the material has a viscosity of 100cp or more.
In addition, it is possible to apply a process of coating a substrate to mass production processes.
In addition, it is possible to improve a substrate shooting rate of droplets by plasma processing a surface of the substrate according to features of droplets to be coated on the surface of the substrate.
In addition, it is possible to divide a precoated area and an area not coated prior to performing a coating process by plasma processing the area to be coated, in consideration of features of droplets coated on a surface of a substrate.
In addition, it is possible to easily shoot droplets injected from a spray nozzle by charging or discharging a surface of a substrate through a plasma processing.
In addition, it is possible to easily adjust conditions for coating a substrate by closing a spray nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings and the detailed description, unless otherwise described, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The relative size and depiction of these elements may be exaggerated for clarity, illustrating, and convenience.

FIG. 1 is a schematic cross-sectional view of a spray nozzle according to a first exemplary embodiment of the present disclosure.
FIG. 2 is a schematic cross-sectional view of a spray nozzle according to a second exemplary embodiment of the present disclosure.
FIG. 3 is a schematic plane view of a spray nozzle according to a second exemplary embodiment of the present disclosure.
FIG. 4 is a schematic cross-sectional view of a spray nozzle according to a third exemplary embodiment of the present disclosure.
FIG. 5 is a schematic cross-sectional view of a spray nozzle according to a fourth exemplary embodiment of the present disclosure.
FIG. 6 is a photograph showing different states of injection of liquid in different voltages from a spray nozzle according to FIGs. 1 to 5.
FIG. 7 is a photograph showing a PET film coated with PEDOT conducting polymer through a spray nozzle according to FIGs. 1 to 5.
FIG. 8 is a photograph showing surface roughness of a film coated according to FIG. 7.
FIG. 9 is a schematic view of a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure.
FIG. 10 is a schematic view of a controller in a coating system using a spray nozzle according to FIG. 9.
FIG. 11 is a schematic graph of a result of monitoring a stable initial spraying state through an amperometry in a coating system using a spray nozzle according to FIG. 9.
FIG. 12 is a schematic skewed view of a coating system using a spray nozzle according to a sixth exemplary embodiment of the present disclosure.
FIG. 13 is a schematic skewed view of inside a container in a coating system using a spray nozzle according to claim 12.
FIG. 14 is a schematic plane view of inside a container in a coating system using a spray nozzle according to claim 12.
FIG. 15 is a schematic view of a substrate plasma processed by a plasma processor in a coating system using a spray nozzle according to claim 12.
FIG. 16 is a schematic skewed view of coating a plasma processed substrate through a spray nozzle in a coating system using a spray nozzle according to FIG. 12.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. Accordingly, various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be suggested to those of ordinary skill in the art. Also, descriptions of well-known functions and constructions may be omitted for increased clarity and conciseness.
Hereinbelow is detailed explanation of a spray nozzle according to a first exemplary embodiment of the present disclosure and a coating system thereof with reference to the attached drawings.
FIG. 1 is a schematic cross-sectional view of a spray nozzle according to a first exemplary embodiment of the present disclosure.
With reference to FIG. 1, a spray nozzle according to a first exemplary embodiment of the present disclosure 100 may make the liquid being injected to collide with gas, thereby performing a primary atomization of the liquid, and then apply an electric field to the atomized liquid, thereby performing a secondary atomization, so as to inject the liquid in a fine droplet state having a uniform size. This spray nozzle 100 comprises a liquid nozzle 110, gas nozzle 120, voltage supply 130, and case 140.
The liquid nozzle 110 is a path for liquid to flow, whereby liquid is injected towards a substrate.
The gas nozzle 120 is a path for gas, whereby gas is injected towards an injection path of liquid so that the gas collides with the liquid and thus a primary atomization of the liquid can be performed.
Herein, the gas nozzle 120 may preferably inject gas such that the gas vertically collides with the injection path of the liquid.
In other words, collision of the gas and liquid is a very important factor to the primary atomization of the liquid, and thus in order to atomize the liquid stably, the gas and the injection path of the liquid must collide vertically to each other.
That is, if the gas fails to vertically collide with the injection path of the liquid, the gas may have an effect in the injection direction of the liquid or in the opposite direction of the injection direction, and in the case where force is applied in the injection direction of the liquid by collision, atomized droplets would collide with the substrate S at a too fast speed, thereby possibly causing rebounding of the droplets, whereas in the case where force is applied in the opposite direction of the injection direction of the liquid by collision, the injection of the liquid would be interrupted by the gas, thereby possibly having a negative effect on the injection speed or injection flow rate.
Therefore, in order to prevent these problems, it is desirable that the gas vertically collides with the injection path of the liquid, but there is no limitation thereto, since it is also possible to resolve the aforementioned problems by adjusting the injection speed of the liquid.
Furthermore, the gas nozzle 120 may be provided such that gas may be injected along a tangent direction of an outer circumference of the liquid injection path, but there is no limitation thereto.
Meanwhile, there is a plurality of gas nozzles 120, each of which is spaced by a same distance from one another on an outer circumference of the liquid injection path, such that gas may be injected along a tangent direction of the outer circumference of the liquid injection path, but there is no limitation thereto.
The voltage supply 130 is electrically connected to the liquid nozzle 110, and generates an electric field between the liquid nozzle 110 and substrate S, more particularly between the spray nozzle 100 and substrate S so as to perform a primary atomization of the liquid by collision with the gas.
Herein, the substrate S is at a ground state, and thus when voltage is applied from the voltage supply 130 to the liquid nozzle 110, a voltage difference would occur between the substrate S and the liquid nozzle 110, thereby creating an electric field.
As the liquid that has gone through the primary atomization by collision with the gas is drawn by the electric field created by the voltage applied from the voltage supply 130, the liquid would go through a secondary atomization.
As such, by atomizing liquid sequentially by collision with gas and through an electric field, it is possible to create fine droplets of a uniform size and also inject a large amount of liquid. Furthermore, by guiding the liquid to be injected towards the substrate S using the electric field, it is possible to resolve the problem of the rebounding of the droplets, and reduce material consumption at the same time.
The case 140 is for accommodating the liquid nozzle 110 inside thereof.
That is, the gas nozzle 120 is provided outside the case 140 unlike the liquid nozzle 110, and thus the collision with the gas occurs outside the case 140.
Hereinbelow is explanation on operations of a first exemplary embodiment of the aforementioned spray nozzle.
First of all, liquid supplied from outside, more preferably liquid supplied from a separate liquid supply is supplied to the liquid nozzle 110, flows inside the liquid nozzle 110, and is then injected towards the substrate S.
The liquid injected towards the substrate S collides with the gas injected from the gas nozzle 120 between the substrate S and the case 140, and a primary atomization occurs by the collision with the gas. By the collision with the gas, the surface of the liquid becomes unstable, and due to this instability of the liquid surface, a secondary atomization by the electric field would occur actively even when the liquid has non-polarity or has an extremely low electrical conductivity, and more detailed explanation thereof will be mentioned hereinafter.
Herein, in order to prevent the collision with the gas affecting the injection speed of the liquid, it is preferable that the gas vertically collides with the injection path of the liquid, but there is no limitation thereto.
The liquid would go through a primary atomization by collision with the gas, and then this unstabilized liquid surface goes through a secondary atomization by the electric field created between the nozzle 100 and the substrate S. Since the liquid has already been atomized by collision with the gas, the flow rate of the liquid that can be atomized increases significantly, which directly leads to the increase of process speed.
Meanwhile, liquid having non-polarity or having a low electrical conductivity may also be easily atomized by a spray nozzle according to a first exemplary embodiment of the present disclosure, and more detailed explanation thereon will be mentioned hereinafter.
The force applied to an electric spraying that uses electric energy is as follows: ${\vec{f}}_{e} = ρ_{e} \vec{E} - \frac{1}{2} {|\vec{E}|}^{2} \nabla ε + \nabla (\frac{1}{2} (ε - ε_{0}) {|\vec{E}|}^{2})$
Herein, ρ_e indicates free electron on liquid surface, indicates dielectric constant of the liquid surface, ε₀ indicates dielectric constant in vacuum, and E indicates electric field.
Herein, in the case of dielectric liquid, in the above equation, the second and third forces will be applied, while in the case of a non-polar liquid, in the above equation, an electric force of the second section will be applied. This is called a dielectrophoretic force. Herein, since there exists only an electric force that acts on the vertical direction of the liquid surface and not in the direction tangent to the liquid surface, there won't be formed a liquid surface having a conical shape called the taylor-cone, and thus atomizing the liquid will not be easy with only an electric field.
However, by making droplets unstable at the same time of performing a primary atomization by inducing collision with gas as in a spray nozzle according to a first exemplary embodiment of the present disclosure 130, a secondary atomization may occur in spite of a weak dielectrophoretic force.
Accordingly, by utilizing a spray nozzle according to an exemplary embodiment of the present disclosure 100, it is possible to easily induce atomization of even nonconductive liquid regardless of the polarity of the liquid.
Next is explanation on a spray nozzle according to a second exemplary embodiment of the present disclosure 200.
FIG. 2 is a schematic cross-sectional view of a spray nozzle according to a second exemplary embodiment of the present disclosure.
With reference to FIG. 2, a spray nozzle according to a second exemplary embodiment of the present disclosure 200 may make the liquid being injected to collide with gas, thereby performing a primary atomization of the liquid, and then applying an electric field to the atomized liquid, thereby performing a secondary atomization, so as to inject the liquid in a fine droplet state having a uniform size. This spray nozzle 200 comprises a liquid nozzle 110, gas nozzle 120, voltage supply 130, and case 240.
The functions of the liquid nozzle 110, gas nozzle 120 and voltage supply 130 are the same those according to the first exemplary embodiment of the present disclosure, and thus further explanation is omitted.
FIG. 3 is a schematic plane view of a spray nozzle according to an second exemplary embodiment of the present disclosure.
With reference to FIG. 3, the case 240 is for accommodating the liquid nozzle 110 and the gas nozzle 120 inside, and making the liquid and gas collide inside thereof.
That is, the second exemplary embodiment is different from the first exemplary embodiment in that when liquid is injected outside the case 240, the liquid will be in a state that had already gone through a primary atomization, and then outside of the case 240, a secondary atomization will be performed by an electric field.
Meanwhile, inside the case 240, the gas injected from the gas nozzle 120 flows, and there is also formed a gas flow path 241 that guides gas to vertically collide with the injection path of the liquid.
The reason why the gas has to collide with the injection path of the liquid was explained hereinabove and thus repeated explanation is omitted.
In addition, the case 240 may be provided with a guide 242 that guides liquid to be injected towards a substrate S, but there is no limitation thereto.
Herein, the guide 242 is provided on a surface near the substrate S in the case 240, but the cross-section area of the guide 242 increases as it gets farther from the substrate S, but there is no limitation thereto.
Next is explanation on a spray nozzle according to a third exemplary embodiment of the present disclosure 300.
FIG. 4 is a schematic cross-sectional view of a spray nozzle according to a third exemplary embodiment of the present disclosure.
With reference to FIG. 4, a spray nozzle according to a third exemplary embodiment of the present disclosure 300 comprises a liquid nozzle 310, gas nozzle 120, voltage supply 130, and case 240.
The gas nozzle 120 and voltage supply 130 are the same as those in the first exemplary embodiment of the present disclosure, and the case 240 is the same as that in the second exemplary embodiment of the present disclosure, and thus detailed explanation is omitted.
The liquid nozzle 310 is where liquid flows inside and injects the liquid towards the substrate S. In the spray nozzle according to the third exemplary embodiment of the present disclosure 300, there is provided a plurality of liquid nozzles 310 having different diameters, one of the plurality of liquid nozzles accommodating another liquid nozzle or one of the plurality of liquid nozzles accommodated inside another liquid nozzle.
Herein, the plurality of liquid nozzles 110 may have a same central axis, the liquid nozzle 110 with the smallest diameter disposed sequentially starting from the middle and the liquid nozzle 110 with the largest diameter disposed outermost, but there is no limitation thereto.
In addition, the liquid flowing inside the plurality of liquid nozzles 310 may consist of numerous different liquids. Herein, numerous different liquids may be supplied to the different liquid nozzles 310, and then as they flow along the injection path of the liquid, and then collide with gas, they may be mixed together, and thus when they are injected outside the case 240, they may be injected as a mixed liquid, but there is no limitation thereto.
Next is explanation on a spray nozzle according to a fourth exemplary embodiment of the present disclosure 400.
FIG. 5 is a schematic cross-sectional view of a spray nozzle according to a fourth exemplary embodiment of the present disclosure.
With reference to FIG. 5, a spray nozzle according to a fourth exemplary embodiment of the present disclosure 400 comprises a liquid nozzle 410, gas nozzle 120, voltage supply 130, and case 240.
The gas nozzle 120 and voltage supply 130 are the same as those in the first exemplary embodiment of the present disclosure, and the case 240 is the same as that in the second exemplary embodiment of the present disclosure, and thus further detailed explanation in omitted.
The liquid nozzle 410 is where liquid flows inside, and injects the liquid towards the substrate S. In the spray nozzle according to the fourth exemplary embodiment of the present disclosure 400, there is provided a plurality of liquid nozzles 410, one of the plurality of liquid nozzles distanced in a parallel direction from another liquid nozzle.
Herein, the liquid flowing inside the plurality of liquid nozzles 410 may consist of numerous different liquids, and it is desirable that the plurality of liquid nozzles 410 are disposed closely to one another such that the different liquids are sufficiently mixed inside the case 240 and then be injected.
Next is explanation on an experimental example of an atomization process of a liquid regarding a spray nozzle according to a first, second, third or fourth exemplary embodiment of the present disclosure.
FIG. 6 is a photograph showing different states of injection of liquid in different voltages from a spray nozzle according to FIGs. 1 to 5, and FIG. 7 is a photograph showing a PET film coated with PEDOT conducting polymer through a spray nozzle according to FIGs. 1 to 5. And FIG. 8 is a photograph showing surface roughness of a film coated according to FIG. 7.
With reference to FIGs. 6 to 8, as the liquid, a high polymer conductive PEDOT that has a high viscosity and that is not easily atomized by the mutual connectivity of the high polymer material was used, supplied at a speed of 80 µl/min, and as gas, air was pressurized by 1bar and used. Herein, the size of atomized liquid was in the range of approximately 10∼150µm.
With reference to FIG. 6, a voltage was applied through the voltage supply 130, voltages of 2, 3, 4 kV were applied between the spray nozzle and substrate S, and there was a tendency that as the voltage increased the jet length of the liquid got shorter. Herein, the length of the liquid jet getting shorter means that the atomizing process of the liquid is active.
Meanwhile, in the case where the gas nozzle 120 has a diameter of 2.2mm, the flow rate against the pressure applied is approximately 20∼120cm³/sec, which is 1∼10m/sec in velocity.
Herein, for the liquid that has gone through a primary atomization to go through a secondary atomization by an electric field, sufficient electric force should be obtained within the limited time it takes from the spray nozzle to the substrate S, and considering the speed within the applied pressure range, the time it takes for the droplets to approach the substrate is (distance between the substrate and spray nozzle)/speed, and according to the experiment, it took approximately 10msec or more until the liquid completed the secondary atomization.
Therefore, the minimum distance needed from after a primary atomization is completed until a secondary atomization is completed is 1cm, and as in one of the second exemplary embodiment to fourth exemplary embodiment of the present disclosure, in the case where liquid goes through a primary atomization inside the case 240 of the spray and goes through a secondary atomization outside the case 240, the distance between the spray nozzle and substrate S needed for the liquid to go through a secondary atomization sufficiently between the spray nozzle and the substrate S is 1cm.
Meanwhile, according to the spray nozzle of the present disclosure, the flow rate of the liquid may be increased to 10^-8m³/sec or more, and according to the present experimental example, it can be seen that the flow rate of the liquid injected from the spray nozzle is 10^-7m³/sec, which is above the injection flow rate of approximately 10^-10 to 10^-9 m³/sec when using electric energy.
With reference to FIGs. 7 and 8, in the case of atomizing conductive PEDOT high polymer and injecting the same on a PET film according to the present experimental example, it was possible to obtain a highly transparent conductive film, and upon observing the surface roughness using an electron microscope, the surface roughness appeared to be highly uniform.
Next is explanation on a coating system that uses a spray nozzle according to a fifth exemplary embodiment of the present disclosure.
FIG. 9 is a schematic view of a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure, and FIG. 10 is a schematic view of a controller in a coating system using a spray nozzle according to FIG. 9.
With reference to FIGs. 9 and 10, a coating system that uses a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500 performs coating using a spray nozzle according to first to fourth exemplary embodiments of the present disclosure. The coating system 500 also monitors whether or not the atomized liquid is being stably injected and coated on a substrate. The coating system 500 comprises a spray nozzle 100, 200, 300, 400 according to first to fourth exemplary embodiments, support 510, amperometer 520, liquid supply 530, gas supply 540, nozzle transferrer 550, and controller 560.
The spray nozzle 200 is the same as those in the aforementioned first to fourth exemplary embodiments, and thus detailed explanation thereof is omitted, and for convenience of explanation, it is assumed that a spray nozzle according to a second exemplary embodiment 200 is used.
The support 510 is on which a substrate S is disposed, and the support 510 is provided as a flat panel member.
In the coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500, the substrate S is disposed on an upper part of the support 510, and a first transferrer 551 is provided on a lower part of the support 510, so that the substrate S that has been coated can perform the next process.
The amperometer 520 is electrically connected between the substrate S and the spray nozzle 200. And the amperometer 520 measures the current between the substrate S and the spray nozzle 200.
Herein, based on the current information between the substrate S and the spray nozzle 200 obtained by the amperometer 520, it is possible to monitor whether or not liquid from the spray nozzle 200 is being stably injected and atomized.
The liquid supply 530 supplies the liquid that flows inside the liquid nozzle 110 of the spray nozzle 200, which is a well known technology and thus detailed explanation thereof is omitted.
The gas supply 540 supplies the gas that flows inside the gas nozzle 110 of the spray nozzle 200, which is a well known technology and thus detailed explanation thereof is omitted.
The transferrer 550 transfers at least one of the aforementioned spray nozzle 200 and support 510. The transferrer 550 comprises a first transferrer 551 configured to transfer the support 510 and a second transferrer 555 configured to transfer the spray nozzle 200.
The second transferrer 555 is connected to the spray nozzle 200 to transfer the spray nozzle 200 in a direction either approaching or distancing from the support 510 or in a direction parallel to the support 510.
That is, assuming the directions parallel to the support 510 are x and y axis directions, and the direction approaching or distancing from the support 510 is z axis direction, the second transferrer 555 transfers the spray nozzle 200 in at least one direction of x, y, and z axis directions.
With reference to FIG. 10, with at least one of the voltage amount supplied from the voltage supply 130 and the pressure of the gas supplied from the gas nozzle 120 predetermined, the controller 560 receives the current information between the substrate S and the spray nozzle 200 from the amperometer 520 and controls the injection conditions of the liquid being injected towards the substrate S or the movement of the spray nozzle 200. The controller 560 comprises an electric field control module 561, pressure control module 562, current amount control module 563, transfer control module 564, and injection speed control module 565.
The electric field control module 561 adjusts the voltage applied to the liquid nozzle 110 through the voltage supply 130 and controls the electric field that occurs between the substrate S and the spray nozzle 200.
As aforementioned, the size of the electric field relates to a secondary atomization of the liquid, and thus it is possible control the speed of the second atomization by adjusting the size of the electric field by the electric field control module 561.
The pressure control module 562 adjusts the pressure of the gas that is supplied from the gas supply 540. As aforementioned, the primary atomization of the liquid occurs as the gas collides with the liquid being injected, and thus it is possible to control the primary atomization by adjusting the pressure of the gas flowing inside the gas nozzle 120.
The current amount control module 563 receives the current information obtained by the amperometer 520 and controls the current amount between the substrate S and spray nozzle 200. The current amount control module 563 acknowledges the flow tendency of the current amount between the substrate S and spray nozzle 200 and monitors whether or not the liquid is being injected and atomized stably.
That is, if there is almost no flow of current amount between the substrate S and spray nozzle 200, it means that the liquid is being injected and atomized stably.
In addition, if there is flow of current amount, it means that the liquid is not being injected or atomized stably, and thus it is possible to control at least one of the electric field control module 561 and pressure control module 562 to redetermine the initial injection conditions of the liquid such as the size of the electric field and pressure of the gas so that the liquid can be injected and atomized stably, but there is no limitation thereto.
The transfer control module 564 controls the movement of the nozzle transferrer 550 to control the location and transferring speed of the spray nozzle 200 or the support 510.
That is, it is possible to move the first transferrer 551 to change the location of the substrate S or move the second transferrer 555 to change the initial injection position of the spray nozzle 200 or receive the current information obtained through the amperometer 520 and change the location of the spray nozzle 200 to a location where the liquid can be injected stably, but there is no limitation thereto.
In addition, it is possible to transfer the spray nozzle 200 even when the liquid is being injected, and control the transferring speed so that the liquid being injected is not affected by the transfer, but there is no limitation thereto.
The injection speed control module 565 controls the injection speed of the liquid being injected from the spray nozzle 200 by adjusting the flow rate of the liquid supplied to the liquid nozzle 110.
When there is no change of the liquid density and diameter of the liquid nozzle 110, the injection speed of the liquid is proportional to the mass flow rate or volumetric flow rate of the liquid, and thus it is possible to control the injection speed of the liquid by adjusting the mass flow rate or volumetric flow rate of the liquid.
Herein, the injection speed of the liquid affects the time it takes for the liquid to arrive at the substrate S, and if this time is significantly short, the liquid may arrive at the substrate S without having gone through a secondary atomization sufficiently, resulting in increased and nonuniform surface roughness of the coating surface of the substrate S. Thus, the injection speed control module 565 controls the injection speed of the liquid.
Meanwhile, it is necessary to perform a coating operation after checking whether or not liquid is being injected stably from the spray nozzle 200, and for this purpose an additional test substrate may be provided to examine the injection state of the spray nozzle 200, but there is no limitation thereto.
Herein, an amperometer 520 may be additionally provided between the spray nozzle 200 and the test substrate to measure the current amount between the spray nozzle 200 and the test substrate, but there is no limitation thereto, and the amperometer 520 provided between the spray nozzle 200 and the susbtrate S may be used instead.
Meanwhile, there may be further provided a cleaner for cleaning the spray nozzle 200 but there is no limitation thereto.
Next is explanation on operations of a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500 based on an experimental example.
In order to perform a coating operation with a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500, initial injection conditions are determined through the aforementioned electric field control module 561 and pressure control module 562.
In a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500, the voltage supplied from the voltage supply 130 is determined to 1, 2, 3, 4kV through the electric field control module 561, and the pressure of the gas supplied from the gas supply 540 is determined to 1, 2, 3bar through the pressure control module 562.
The current amount between the substrate S and spray nozzle 200 is measured through the amperometer 520 by adjusting at least one of the voltage and pressure.
FIG. 11 is a schematic graph of a result of monitoring a stable initial spraying state through an amperometry in a coating system using a spray nozzle according to FIG. 9.
In FIG. 11, it is shown that when the pressure is 2bar, the flow of the current amount does not change significantly even by change of voltage. Of course, this experimental example is a result derived in the case of using a coating system using a spray nozzle according to a fifth exemplary embodiment of the present disclosure 500, and thus if the size of the spray nozzle 200 and the distance between the spray nozzle 200 and the substrate are changed, the initial injection conditions would be different from the present experimental example, and thus there is no limitation thereto.
Next is explanation on a coating system using a spray nozzle according to sixth exemplary embodiment of the present disclosure 600.
FIG. 12 is a schematic skewed view of a coating system using a spray nozzle according to a sixth exemplary embodiment of the present disclosure, and FIG. 13 is a schematic skewed view of inside a container in a coating system using a spray nozzle according to FIG. 12, and FIG. 14 is a schematic plane view of inside the container in a coating system using a spray nozzle according to FIG. 12.
With reference to FIGs. 12 to 14, a coating system using a spray nozzle according to a sixth exemplary embodiment of the present disclosure is capable of coating a substrate with uniformly atomized droplets and improving a substrate shooting rate of atomized droplets by plasma processing a surface of the substrate prior to coating the substrate. Herein, the coating system using a spray nozzle comprises a support 610, plasma processor 620, liquid supply 530, gas supply 540, transferrer 650, container 660, sensor 670, and controller 680.
The support 610 is where a substrate S is disposed, the support 610 being provided by a flat panel type material, and since it is similar to that explained in the aforementioned fifth exemplary embodiment, and thus detailed explanation is omitted.
However, the support according to a sixth exemplary embodiment of the present disclosure 610 receives voltage or is grounded according to each process of processing the substrate, and for this purpose, the support 610 is provided by a conductive material.
In addition, it is desirable that the outer surface of the substrate S is provided with a coating layer of a non-conductive material so as to prevent direct effect on the substrate S.
Meanwhile, according to the exemplary embodiment of the present disclosure, in an example of voltage being applied to the support 610, as a polarity other than the polarity of plasma is applied to the support 610, the plasma may move towards the substrate S when a surface of the substrate S is plasma processed as it passes the plasma processor 620.
In addition, in an example of the support 610 being grounded, the support 610 is grounded so that plasma is stably formed when a surface of the substrate S is plasma processed as it passes the plasma processor 620.
Furthermore, in another example of the support 610 being grounded, a potential difference may be generated between the spray nozzle 200 and a support 610 so as to form a strong electric field between the spray nozzle 200 and the support 610 when the substrate S is coated as it passes the spray nozzle 200.
Of course, there is no limitation to the aforementioned, and thus if necessary, voltage may be applied to the support 610 or the support 610 may be grounded.
The plasma processor 620 is configured to plasma process an outer surface of the substrate S being transferred through a first transferrer 651 that will be explained hereinafter.
According to an exemplary embodiment of the present disclosure, the plasma processor 620 may clean a coated surface of the substrate S, or process the surface of the substrate S to be coated to be hydrophilic or hydrophobic.
Herein, the hydrophilic or hydrophobic features are determined in consideration of the liquid used in a spray nozzle 200 that will be explained hereinafter.
That is, if the liquid used in the spray nozzle 200 is hydrophilic, an outer surface of the substrate S is plasma processed to be hydrophilic so that the liquid can be effectively shot to the outer surface of the substrate S. On the contrary, if the liquid used in the spray nozzle 130 is hydrophobic, the outer surface of the substrate S is plasma processed to be hydrophobic.
Furthermore, a portion of the substrate S may be processed to be hydrophilic while the remaining portion of the substrate S is processed to be hydrophobic. That is, in a case of coating an outer surface of the substrate S to have a certain pattern, a certain area of an outer surface of the substrate S may be plasma processed to have same features as the liquid, while the remaining area besides the certain area of the outer surface of the substrate S is plasma processed to have different features from the liquid, thereby coating the substrate such that the liquid is concentrated on the certain area.
In addition, in a sixth exemplary embodiment of the present disclosure, the plasma processor 620 may perform a process of charging or discharging the substrate S. Herein, a discharging of the substrate S is performed when charges on the substrate S are distributed non-uniformly, whereas a charging of the substrate S is performed when charges on the substrate S are distributed uniformly.
That is, by discharging or charging the substrate S through the plasma processor 620, it is possible to shoot atomized droplets from the spray nozzle 200 that will be explained hereinafter even more effectively.
Meanwhile, as aforementioned, in an present exemplary embodiment of the present disclosure, the substrate S is processed to be hydrophilic or hydrophobic or discharged or charged through the plasma processor 620, but without limitation.
In addition, in an exemplary embodiment of the present disclosure, the plasma processor 620 may be an atmospheric-pressure plasma, but without limitation.
Explanation on the aforementioned liquid supply 530 and gas supply 540 are the same as in the fifth exemplary embodiment, and thus detailed explanation is omitted.
The transferrer 650 transfers at least one of the aforementioned support 610 and spray nozzle 200. The transferrer 650 comprises a first transferrer 651 configured to transfer the support 610 and a second transferrer 655 configured to transfer the spray nozzle 200.
The first transferrer 651 transfers the support 610, and in a sixth exemplary embodiment of the present disclosure, the first transferrer 651 comprises a rail 652 and an electrode 653.
The rail 652 consists of a pair of rail members facing each other. The support 610 is mounted onto an upper side of the rail members so that the support 610 can slide along the rail 652.
In addition, besides transferring the support 610 along the rail 652, the first transferrer 651 may be provided, but without limitation, such that it rotates the support 610 on the upper side of the rail 652 or transfer the support 610 on a virtual plane that is parallel to the support 610.
The electrode 653 is provided between the pair of rail 652. In response to the support 610 reaching a certain position, the electrode 653 contacts the support 610 and applies voltage to the support or grounds the support 610.
Herein, the electrode 653 has a shape of a roll, a portion of the roll being provided with voltage while the remaining portion being grounded. By rotation, the electrode 653 selectively applies voltage to the support 610 or grounds the support 610.
Meanwhile, the electrode 653 may have a shape of a spring, which applies voltage to the support 610 or grounds the support 610 as it contacts or is distanced from the support 610 by elasticity.
The second transferrer 655 is the same as the second transferrer 555 explained in the fifth exemplary embodiment, and thus detailed explanation is omitted.
The container 660 accommodates the plasma processor 620 and spray nozzle 200 inside thereof, and isolates the substrate S from outside during processing so as to maintain certain processing conditions.
In an exemplary embodiment of the present disclosure, there is formed an inlet 661 to which the substrate S is provided and an outlet 662 to which the substrate S is output, and the first transferrer 651 is extended towards the inlet 661 and the outlet 662.
In addition, the inlet 661 and the outlet 662 are provided such that they may be open/closed to close the inside of the container 660 during plasma processing and coating processing.
Furthermore, the container 660 may be provided with a gas channel 663 through which nitrogen or inert gas may be injected inside the container 660.
Meanwhile, for an effective coating process, a certain gas concentration, humidity and temperature may be maintained, without limitation, inside the container 660.
In other words, it is possible to measure the gas concentration, humidity and temperature inside the container 660, and adjust the opening time etc. of the gas channel 663 to maintain the optimal gas concentration, humidity and temperature inside the container 660 based on the measurement results.
The sensor 670 measures location information of the support 610.
In an exemplary embodiment of the present disclosure, the sensor 670 is provided in plural number, each spaced from one another along the rail 652. The sensor 670 divides the location of the support 610 into an inlet section, a section being affected by the plasma processor 620, a section being affected by the spray nozzle 200, and an outlet section, and measures where the support 610 is located.
The controller 680 receives location information of the support 610 from the aforementioned sensor 670, and controls operations of at least one of the plasma processor 620, spray nozzle 200, and transferrer 650. More specific operations are the same as those explained in the fifth exemplary embodiment and thus detailed explanation is omitted.
Next is explanation on operations of a sixth exemplary embodiment of the aforementioned coating system using a spray nozzle.
Hereinbelow is explanation on operations of a coating system using a spray nozzle according to a sixth exemplary embodiment of the present disclosure based on the transferring direction of the substrate S.
The substrate S is fixated to the support 610 disposed outside the container 660, and then the support 610 is moved inside the container 660 through the first transferrer 651.
Herein, when the support 610 moves inside the container 660 through the inlet 661 of the container 660, the inlet 661 closes, and the support 610 moves to a processing area of the plasma processor 620.
Meanwhile, when the support 610 arrives at a lower side of the plasma processor 620, the controller 680, having acknowledged the location of the support 610 through the sensor 670, controls operations of the plasma processor 620 to output plasma towards the support, more particularly towards the substrate S.
By the plasma being output towards the substrate S, the substrate S is processed to be hydrophilic or hydrophobic, or charged or discharged. And to improve the effectiveness of the processings, the support 610 is provided with voltage or is grounded by the electrode 653.
FIG. 15 is a schematic view of a substrate plasma processed by a plasma processor in a coating system using a spray nozzle according to FIG. 12.
With reference to FIG. 15, in the sixth exemplary embodiment of the present disclosure, in order to coat the substrate S with letters 'ENJET', the letter part of 'ENJET' is processed to be hydrophobic while the background part is processed to be hydrophilic through the plasma processor 620.
Meanwhile, the plasma processed substrate S moves to the lower side of the spray nozzle 200 by the first transferrer 651, and the sensor acknowledges the location of the support 610, and the controller 680 controls the operations of the spray nozzle 200.
The process of coating the substrate S by the spray nozzle was explained in the first exemplary embodiment to the fourth exemplary embodiment, and thus detailed explanation is omitted.
Herein, depending on the features of the atomized liquid, more particularly depending on whether the atomized liquid is hydrophilic or hydrophobic, coating of the atomized liquid may be concentrated on letters 'ENJET', or on the background part of 'ENJET'.
FIG. 16 is a schematic skewed view of coating a plasma processed substrate through a spray nozzle in a coating system using a spray nozzle according to FIG. 12.
With reference to FIG. 16, since the liquid used in an exemplary embodiment of the present disclosure is hydrophobic, the substrate S is coated and a pattern is formed such that the coating of the atomized liquid is concentrated on the letters 'ENJET'.
Meanwhile, when the substrate S which has completed being coated through the spray nozzle 200 is transferred to the outlet 662, the sensor 670 measures the location the substrate S and opens the outlet 662, and transfers the substrate S outside the container 660.
A number of examples have been described above. Nevertheless, it will be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in a described system, architecture, device, or circuit are combined in a different matter and/or replaced or supplemented by other components or their equivalents. Accordingly, other implementations are within the scope of the following claims.

DESCRIPTION OF REFERENCE NUMERALS

100:: SPRAY NOZZLE
110:: LIQUID NOZZLE
120:: GAS NOZZLE
130:: VOLTAGE SUPPLY
140:: CASE
S:: SUBSTRATE
200:: SPRAY NOZZLE
240:: CASE
300:: SPRAY NOZZLE
310:: LIQUID NOZZLE
400:: SPRAY NOZZLE
410:: LIQUID NOZZLE
500:: COATING SYSTEM USING SPRAY NOZZLE
510:: SUPPORT
520:: AMPEROMETER
530:: LIQUID SUPPLY
540:: GAS SUPPLY
550:: TRANSFERRER
560:: CONTROLLER
600:: COATING SYSTEM USING SPRAY NOZZLE
610:: SUPPORT
620:: PLASMA PROCESSOR
650:: TRANSFERRER
660:: CONTAINER
670:: SENSOR
680:: CONTROLLER

Claims

A spray nozzle comprising:
a liquid nozzle injecting liquid towards a substrate;

a gas nozzle for injecting gas to collide with the liquid on an injection path of the liquid to perform a primary atomization of the liquid; and

a voltage supply connected to the liquid nozzle, the voltage supply for applying voltage to the liquid nozzle to generate an electric field between the liquid nozzle and substrate to perform a secondary atomization of the liquid.
The spray nozzle according to claim 1,
further comprising a case for accommodating the liquid nozzle inside thereof,
wherein the liquid and gas are made to collide with each other outside the case.
The spray nozzle according to claim 1,
further comprising a case for accommodating the liquid nozzle and gas nozzle inside thereof, the case provided with a gas path for guiding a flowing direction of the gas so that the gas being injected from the gas nozzle collides with the liquid on the injection path of the liquid, wherein the gas is made to collide with the liquid inside the case.
The spray nozzle according to claim 3,
wherein the case is provided with a guide part that is dented towards the inside on an end closer to the substrate, a cross-sectional area of the guide increasing as it gets farther from the substrate, in order to guide an injection direction of the liquid so that the liquid is injected towards the substrate.
The spray nozzle according to claim 4,
wherein a distance between the guide part and the substrate is 1cm or more so that a secondary atomization of the liquid can be completed between the guide part and the substrate.
The spray nozzle according to claim 3,
wherein the gas path guides the flowing direction of the gas so that the gas vertically collides with the injection path of the liquid.
The spray nozzle according to claim 1,
wherein a flow rate of the liquid supplied to the liquid nozzle is 10^-8m³/s or more.
The spray nozzle according to claim 1,
wherein the liquid nozzle consists of a plurality of liquid nozzles each having a different diameter, any one of the plurality of liquid nozzles accommodating another of the plurality of liquid nozzles inside thereof or any one of the plurality of liquid nozzles accommodated inside of another of the plurality of liquid nozzles.
The spray nozzle according to claim 1,
wherein the liquid nozzle consists of a plurality of liquid nozzles, any one of the plurality of liquid nozzles being distanced from another of the plurality of liquid nozzles in a parallel direction.
A coating system using a spray nozzle, the coating system comprising:
a support where a substrate is disposed;

a spray nozzle injecting liquid towards a surface of the substrate according to any one of claims 1 to 9;

a liquid supply supplying liquid being injected from the liquid nozzle;

a gas supply supplying gas flowing inside the gas path; and

a transferrer transferring at least one of the support and the spray nozzle.
The coating system according to claim 10,
further comprising a plasma processor configured to plasma process the substrate;
wherein the spray nozzle is provided with a substrate plasma processed through the plasma processor.
The coating system according to claim 11,
wherein the plasma processor cleans a surface of the substrate, or processes the surface of the substrate to be hydrophilic or hydrophobic depending on the liquid injected from the spray nozzle.
The coating system according to claim 11,
wherein the plasma processor performs at least one of charging and discharging the substrate, and
the spray nozzle is spaced by 500mm or less from the plasma processor along a transferring path of the substrate.
The coating system according to claim 10,
wherein the transferrer comprises a first transferrer configured to transfer the support; and
a second transferrer configured to move the spray nozzle in a direction approaching or distancing from the support.
The coating system according to claim 10,
further comprising a sensor configured to obtain location information of the support; and
a controller configured to receive the location information of the support through the sensor and control operations of at least one of the plasma processor, spray nozzle, voltage applier and transferrer.
The coating system according to claim 15,
wherein the controller comprises:
an electric field control module configured to control an intensity of an electric field formed between the spray nozzle and the support by adjusting a voltage amount applied to the spray nozzle;

a pressure control module configured to control a pressure of the gas that collides with the liquid in the spray nozzle;

a transfer control module configured to control a movement of the transferrer; and

a flow rate control module configured to control a flow rate of the liquid injected form the spray nozzle.
The coating system according to claim 16,
further comprising an amperometer connecting the spray nozzle and the substrate, and measuring current information between the spray nozzle and the substrate;
wherein the controller further comprises a current amount control module receiving current information obtained by the amperometer and controls a current amount between the substrate and the spray nozzle.
The coating system according to claim 17,
further comprising a test substrate to which liquid being injected from the spray nozzle is shot, the test substrate testing a injection state of the spray nozzle through current information of the liquid shot,
wherein the amperometer is connected between the liquid nozzle and the test substrate and measures the current information of the shot liquid.
The coating system according to claim 10,
wherein the support is made of conductive material or provided with a coating layer of non-conductive material on an external surface thereof.
The coating system according to claim 19,
wherein the support receives voltage or is grounded selectively depending on its location.
The coating system according to claim 10,
further comprising a container accommodating a spray nozzle inside thereof, the container comprising an inlet and outlet for entering/exiting of the substrate.
The coating system according to claim 21,
wherein the container is provided with a gas channel for injecting nitrogen or inert gas inside thereof or discharging the nitrogen or inert gas.
The coating system according to claim 21,
wherein at least one of a certain gas concentration, temperature and humidity is maintained inside the container.