KR20150011222A

KR20150011222A - Roll to Roll fine pattern Printing System for Continuous process by non-contact Electro-Static Deposition

Info

Publication number: KR20150011222A
Application number: KR20130086236A
Authority: KR
Inventors: 박경배; 이창훈
Original assignee: (주)브이에스테크
Priority date: 2013-07-22
Filing date: 2013-07-22
Publication date: 2015-01-30

Abstract

The present invention relates to a roll-to-roll printing system for fine pattern printing using an electro static deposition (ESD) head. According to the present invention, the edge position control (EPC) equipment are disposed on an inlet and outlet sides of a printed body such that the meandering of the printed body is controlled, and an ESD head for an Ni ink injection is mounted such that a fine electrode pattern can be formed on the printed body on a non-contact basis. The present invention includes: an unwinding roll and a rewinding roll for printed material supply and recovery; an idle roller which transports the printed material supplied from the unwinding roll while providing adequate tension for the printed material; first and second edge position control systems which are respectively disposed on an inlet side of the unwinding roll, and a recovery side of the rewinding roll to control the meandering of the printed material transported by the idle roller; a work plate provided with a plurality of vacuum holes to vacuum adsorb the printed material passing through the first EPC; an electro static deposition (ESD) head disposed above the work plate to inject ink for non-contact pattern formation on the printed material; and a curing system which prevents ink flow while curing the pattern by applying heat to the printed material passing through the ESD head.

Description

Technical Field [0001] The present invention relates to a roll-to-roll printing system for fine pattern printing by an electrostatic force induction ink jet head,

The present invention relates to a continuous process roll-to-roll printing system for precisely printing a lattice-like fine electrode pattern in a non-contact manner on a substrate such as a transparent conductive film (ITO) or a flexible film in a continuous process roll- And more particularly, to an ESD head (Electro-Static Deposition head) which ejects Ag ink or conductive ink by controlling the meandering of a printed material by providing an EPC (Edge Position Control) (Electrostatic force-induced inkjet head) mounted on a substrate to form a fine electrode pattern having a desired line width in a non-contact manner.

Flexible display is a display manufactured using thin and flexible substrates that can bend, bend, or twist within a few centimeters of paper without loss of existing display characteristics. Unlike a rigid display, , Thin, strong in impact resistance, and free from bending. Flexible displays can be distinguished by their uses and functions as rugged displays, bending displays, and rollable displays. Lightweight, robust and bendable displays can be applied to portable high-end mobile devices such as DMB, WiBro, and PDA, and are expected to become rolled up in the future.

As a device for manufacturing a flexible display, a roll-to-roll process system is used. The roll-to-roll process system is used for printing, patterning, etc., in the middle of transferring a web having a width and length as large as thickness, such as a plastic film or paper, from an unwinder to a rewinder, It is a process system that can be applied to various production techniques such as coating, curing, and coating.

In order to produce a flexible liquid crystal display by a roll-to-roll process, a process such as formation of an orientation film such as polyimide, application of a spacer, thread / short dispensing, liquid crystal dispensing or liquid crystal injection is performed on one side of a web These processes can be performed in a stationary state. Since the various processes described above for manufacturing flexible liquid crystal displays are performed on one side of the web, contact for transfer is virtually impossible on one side of the web where such a process is performed. In addition, when a nip roller that closely conveys only the edge of the web is applied, it is difficult to convey the web by the nip roller because there is a possibility that the web will be crying or musk. In addition, it is difficult to precisely align the upper / lower plate when the process is proceeded with tension applied.

On the other hand, the main process parameters for increasing the yield of electronic device printing are metal ink (ink viscosity, solvent content, metallic material types: nickel, silver, copper, etc.), substrate (surface treatment: corona coating, (Cell depth), dry (dry air volume, wind speed, etc.), curing conditions (such as temperature, humidity, and light transmittance), process parameters (tension, speed, nip force, (curing: kind of curing-IR (infrared ray), UV (ultraviolet ray), electron beam). Research on manufacturing electronic devices such as OLED (Organic Thin Film Transistor), OTFT (Organic Thin Film Transistor), OSC (Organic Solar Cell) and RFID (Radio Frequency Identification) It is done externally. The advantage of printing technology is that it is possible to fabricate a multi-layered electronic device by printing method, which is a simple and cost-saving technique compared to the existing silicon-based electronic device manufacturing technology.

When electronic devices such as RFID and solar cells are printed using conductive metal inks based on a roll-to-roll (R2R) process, high temperature drying and curing processes are performed to obtain the electrical characteristics of the printed pattern. Here, commercialized inks used in electronic printing are solvent based conductive inks containing metal particles or high molecular materials. In order to ensure optimum electrical conductivity, a conductive metal ink is used in a roll-to-roll (R2R) process After printing, drying and curing / annealing are performed.

The roll-to-roll (R2R) process can be used to produce flexible products using a flexible substrate and to apply printing methods such as gravure, offset, and flexo, There is an advantage that mass production is possible.

Figure 1 is a process flow diagram schematically illustrating the overall process of a conventional continuous process roll-to-roll printing system.

A conventional continuous process roll-to-roll (R2R) printing system comprises a web web 3 fed from a unwinder 1 to a rewinder 2, as shown in Figure 1, A driven roll 4 driven so as to be fed from the unwinding roll 1 to the winding roll 2 and a web 3 between the unwinding roll 1 and the winding roll 2, And an idle roll (5) for supporting at a constant tension. The web 3 is a thin material having a length in the longitudinal direction which is very long in comparison with the length in the transverse direction, and means a printed body on which ink is printed on one side.

The web 3 is transferred to the unwinding roll 1 and the winding roll 2 and is then subjected to a printing and coating process 10, 20, a drying or curing process 30, , And a laminating process (40). The movement path of the web 3 in the production line is determined by the arrangement of the driving roll 4 and the idle roll 5 between the unwinding roll 1 and the winding roll 2.

These roll-to-roll (R2R) printing systems can achieve high productivity by allowing continuous material transfer compared to a batch process, and these properties make it possible for traditional spinning, paper making, sheet glass production, continuous rolling, Respectively.

In the conventional roll-to-roll printing system for patterning, the printing material is injected through the nozzles by the bubble forming pressure. Since the nozzle diameter must be relatively large in consideration of the surface tension generated in the nozzle diameter, There is a problem that the patterning of the sculpture can not be performed. In addition, since the patterning region of the printing material is limited to the operating region of the printing head, ultrafine patterning and arbitrary shape patterning are difficult.

In a non-contact roll-to-roll printing apparatus such as a general roll-to-roll inkjet, methods are employed in which printing is performed while conveying the printing medium at a constant speed, or printing is performed in a stationary state after being transported by a predetermined amount.

Both of these two methods are important for constant speed conveyance or constant conveyance of the substrate. A continuous process non-contact method in which a workpiece is transported at a constant speed requires an encoder capable of measuring the feed speed of the workpiece. However, since the roller must not come into contact with the printing surface before the printing surface of the substrate is dried, the speed is measured from the rollers to which the encoder is attached using a nip roller capable of contacting the roller only in the vicinity of the edge of the substrate. However, the above-described nip roller conveying method of the substrate has a disadvantage in that it is difficult to adjust the distance each time the width of the substrate is changed by applying an unbalanced frictional force on both edge sides.

In the non-continuous process non-contact method in which the workpiece is transported by a certain distance and stopped and then worked, there is no significant restriction on the use or positioning of the encoder since a certain amount of the unwinder needs to be wound. In this method, however, there is no configuration for correcting the position of the object to be printed in the process of feeding and transporting the object by the unwinder, and the flatness The deviation is large depending on the thickness and the width of the material, resulting in a problem of causing printing defects.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in order to solve all of the above problems, and it is an object of the present invention to provide an EPC (Edge Position Control) device on an inlet side and an outlet side of a substrate to control the meandering of the substrate, And an object of the present invention is to provide a roll-to-roll printing system for fine pattern printing by an electrostatic force-guided inkjet head capable of forming a fine electrode pattern on a substrate in a non-contact manner by mounting an ESD head to be ejected.

Further, the present invention provides a roll-to-roll printing system for fine pattern printing by an electrostatic force-guided inkjet head capable of precisely adjusting the angle and height of the ESD head and the horizontal and nozzle spacing of the ESD head surface and the material surface to secure a fine line width. There is another purpose in.

In addition, the present invention relates to an electrostatic force-inducing ink jet head capable of improving the flatness of a pattern by vacuum-adsorbing a material in a conveying and printing section of a sheet by adjusting a gap between the web guide and the idler roller, There is another purpose in providing a printing system.

According to an aspect of the present invention, there is provided an image forming apparatus comprising: an unwinding roll and a rewinding roll for feeding and recovering a printed material; An idle roller for conveying while supplying an appropriate tension to the print material supplied from the unwinding roll; First and second edge position control systems (EPCs) respectively installed on the introduction side of the unwinding roll and the recovery side of the rewinding roll to control the meandering of the printed material conveyed through the idler rollers; A work plate for vacuum-adsorbing a print material having a plurality of vacuum holes through the first EPC; An electrostatic force induced ink jet head (ESD) which is disposed on the upper portion of the work stage and ejects ink for forming a pattern on the printing material in a non-contact manner; And a hardening device for preventing the flow of ink while hardening the pattern by applying heat to the print material passed through the ESD head. The present invention also provides a roll-to-roll printing system for fine pattern printing by an electrostatic force-

As described above, according to the present invention, the following effects are realized.

First, EPC equipment is mounted on the inlet side and the discharge side of the printing object to precisely control the meandering along with the conveyance of the printed body, thereby preventing printing defects.

Second, by forming a pattern in a non-contact manner by an ESD head on a flexible material fed by a roll-to-roll method, it is possible to fine pattern the finger bar and to print a high viscosity ink (10 - 10,000 cps) have.

Third, since the pattern is printed on the substrate in a droplet manner by the ESD head, the line width and thickness can be finely formed, and the ink consumption can be drastically reduced. Thereby reducing the amount of ink waste and preventing environmental pollution.

Fourth, since the curing is performed after the patterning of the Ag ink, the printing speed can be improved.

1 is an overall process diagram of a continuous process roll-to-roll printing system according to the prior art,
FIG. 2 is an overall process diagram of a roll-to-roll printing system for fine pattern printing by an electrostatic force-induced inkjet head according to the present invention;
3 is a plan view showing a configuration of an edge position control (EPC) for controlling the meandering of the substrate to be printed,
FIGS. 4A and 4B are explanatory views of the operation of the edge position control unit, and are a plan view and a front view, respectively,
Figs. 5A and 5B are explanatory views of operation of the edge position control unit, and are a plan view and a front view showing a state of correcting the position of a meandering object to be printed,
6A and 6B are a plan view and a front view showing a configuration of a work stage which is a main part of the present invention,
Fig. 7 is a perspective view showing the configuration of an electrostatic force-guiding inkjet head (ESD)
8 is a schematic diagram for explaining the operation of the ESD head control system,
9A and 9B are a front view and a side view showing a configuration of a curing device which is a main part of the present invention.

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

The roll-to-roll printing system for fine pattern printing by the electrostatic force-guiding inkjet head of the present invention controls the meandering of the P < RTI ID = 0.0 > Patterns are formed.

FIG. 2 is a flowchart showing an entire process of a roll-to-roll printing system for fine pattern printing by an electrostatic force-guided inkjet head according to the present invention.

As shown in the drawing, in the embodiment of the present invention, an unwinding roll 2 for supplying a printed material 1 such as a transparent conductive film (ITO: Indium Tin Oxide) or a flexible film, and; An idle roller (4) mounted on a supply path of the print material (1) to convey the print material (1) supplied from the unwinding roll (2) while providing an appropriate tension force; A first edge position control system (hereinafter referred to as EPC) 6 for controlling the meandering of the printed material 1 fed through the idle roller 4; A work plate 8 for vacuum-adsorbing the print material 1 that has passed through the first EPC 6; An electrostatic force induced ink jet head (hereinafter referred to as ESD) electrostatically deposited on an upper portion of the work stage 8 to eject Ag ink for forming a pattern on the printed material 1 in a non-contact manner, (10); A curing device 12 for applying heat to the print material 1 that has passed through the ESD head 10 to prevent the flow of ink while hardening the pattern; A second edge position control device (hereinafter referred to as a second EPC) 14 for controlling the meandering of the printed material 1 that has passed through the curing device 12; And a rewinding roll 16 for winding and recovering the print material 1 passed through the second EPC 14.

Next, the detailed configuration of the present invention will be described.

FIG. 3 is a plan view showing the configuration of edge position control (EPC) 6, 14 for controlling the meandering of a printing object which is a main part of the present invention, FIGS. 4A and 4B are diagrams Fig. 6 is a plan view and a front view showing a state in which the substrate to be printed normally moves on the road; Fig.

As shown in the figure, the first and second EPCs 6 and 14 include EPC rollers 22 and 24 provided at the upper and lower portions of the position to which the printed material 1 is fed; A position sensor 26 installed on both sides of the lower end of the EPC roller 22 to detect an etch portion of the printed material 1; And a cylinder control box 28 which receives a sensing signal of the position sensor 26 and corrects an angle of the EPC rollers 22 and 24 according to the center by tilting the axis of the EPC rollers 22 and 24 back and forth. The cylinder control box 28 is equipped with a cylinder (not shown) that can push and pull the shaft of the EPC rollers 22 and 24. The cylinder is connected to a control unit (not shown) And corrects the meandering angle of the EPC rollers 22 and 24 according to the center while moving the cylinder forward and backward by the correction angle.

4A and 4B, when the edge position of the printed material 1 sensed by the position sensor 26 coincides with the center, it is conveyed as it is, and as shown in Figs. 5A and 5B, When the printed material 1 is being fed in a wrong state, the control unit receives the detection signal of the position sensor 26 to drive the cylinder. The cylinder moves forward and backward, and the EPC rollers 22, 24) to the center.

6A and 6B are a plan view and a front view showing the construction of a work stage which is a main part of the present invention.

As shown in the figure, the vacuum cleaner includes a plate body 30 having a plurality of vacuum holes 30a formed therein and a vacuum generator 30 installed at a lower end of the plate body 30 to perform vacuum through the vacuum holes 30a (Not shown). Through the above-described configuration, it is possible to maintain uniform flatness during vacuum adsorption of the printing material.

Fig. 7 is a perspective view showing the configuration of an electrostatic force-guiding inkjet head (ESD) which is a main part of the present invention, and Fig. 8 shows a schematic configuration diagram for explaining the operation of the ESD head control system.

As shown in the figure, the ESD head 10 includes a head 32 having nozzles 32a for discharging Ni ink droplets on a printing material; A bracket 34 for fixing both ends of the head 32; An ink chamber 36 provided at an upper end of the head 32 to supply ink to the nozzle 32a; A head angle adjusting device 38 installed at the rear end of the ink chamber 36 to adjust the horizontal, tilt, and yaw angles of the head 32; And a head height adjusting device (40) provided at the rear end of the head angle adjusting device (38) to adjust the height of the head.

An operation of supplying ink in a droplet state from the ESD head 10 will be described with reference to FIG.

(-) electrode is connected to the ink chamber of the ESD head 10, and a (+) electrode is connected to the work stage 8 on which the printing material 1 is placed. In this state, when air is introduced from the outside into the ink chamber 36, the air introduced first is filtered through the regulator 42 and transferred to the pressure regulator 44. When the predetermined pressure is maintained in the pressure regulator 44, the maniscus provided in the manifold control unit 46 is changed, and the change signal is supplied from the ink supply controller 48 to perform the ink supply.

When power is supplied from the outside, a pulse voltage is generated from the waveform generator 50 and is transmitted to the switching voltage device 52. The bias voltage generated from the high voltage generating device 54 is supplied to the switching voltage device 52 . The switching voltage device 52 applies a voltage to the (+) (-) electrode connected to the ink chamber 36 and the work stage 8, respectively.

The bias voltage value generated in the high voltage generating device 54 is monitored through the high voltage monitoring system 56 for output. The worker USER graphically confirms the pulse voltage and the high voltage value generated by the waveform generator 50 through the computer screen.

In the above configuration, when power is supplied to the (+) and (-) electrodes respectively connected to the working stage 8 and the ink chamber 36, the bias voltage generated in the high voltage generating device 54 is supplied to the ink chamber 36 At the same time, the liquid droplet ejection is performed while the meniscus provided in the meniscus control unit 46 is changed. In the present invention, a high bias voltage and pulse voltage capable of stabilizing the meniscus are adjusted within a range of 1 to 4 kv and 120 mA, and a jetting frequency of 1 kHz obtained by inputting a square wave having a frequency of 1 kHz is input to the ink chamber 36 Maniscus changed. Accordingly, stable droplets can be separated and ejected onto the printing material 1 in a very short time, thereby printing a fine pattern.

9A and 9B are a front view and a side view showing a configuration of a curing device which is a main part of the present invention.

As shown in the figure, the curing device 12 includes a support frame 62; A heat dissipation cover (64) installed at the lower end of the support frame (62) in a box shape to block heat emission; A halogen lamp 66 fixed at both ends to the heat dissipation cover 64 to perform the hardening of the surface of the ink for minimizing the spread of the ink after printing Ni ink droplets on the printed material 1; A height adjustment mechanism 68 for adjusting the height of the halogen lamp 66 installed at the upper end of the support frame 62 and the other end installed at the heat radiation cover 66 and interlocking with the heat radiation cover 64 .

According to the curing apparatus having the above-described configuration, since the heat radiation cover 64 blocks the leakage of the heat source generated in the halogen lamp 66, the ink (ink) printed on the printed material 1 with the shortest time Can be hardened.

The operation of the roll-to-roll printing system for fine pattern printing by the electrostatic force-induced ink jet head according to the present invention having the above-described configuration will be described.

The print material 1 fed through the unwinding roll 2 is conveyed by the idler roller 4 with a constant tension. The printed material 1 passes through the first EPC 6 and is conveyed to the side of the ESD head 10 after the meandering is adjusted. At this time, the print material 1 having passed through the first EPC 6 is seated on the work stage 8 by the transfer of the main roller, and a vacuum is performed through the vacuum hole at the lower end of the work stage 8 Whereby the printing material is fixed while maintaining the flatness. By applying a high bias voltage and a pulse voltage to the print material 1 and the ESD head 10 placed on the work stage 8, the Ni ink droplets are separated in a short period of time by changing the meniscus, 1). After the printing by the ESD head, the halogen lamp 66 of the curing device 12 applies a heat source to the ink pattern of the printing material to make it hardened. The printed material 1 having passed through the hardening device 12 is again wound on the rewinding roll 16 after the skew of the second EPC 14 is controlled.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be clear to those who have knowledge.

1: Printed material 2: Unwinding roll
4: idler rollers 6, 14: first and second EPCs
8: work plate 10: ESD head
12: hardening device 16: rewinding roll:

Claims

An unwinding roll and a rewinding roll for feeding and recovering a printing material;
An idle roller for conveying the print material fed from the unwinding roll while providing an appropriate tension force;
First and second edge position control systems (EPCs) respectively installed on the introduction side of the unwinding roll and the recovery side of the rewinding roll to control the meandering of the printed material conveyed through the idler rollers;
A work plate for vacuum-adsorbing a print material having a plurality of vacuum holes through the first EPC;
An electrostatic force induced ink jet head (ESD) which is disposed on the upper portion of the work stage and ejects ink for forming a pattern on the printing material in a non-contact manner; And
A hardening device for preventing the flow of ink while applying heat to the printed material passing through the ESD head to harden the pattern
Wherein the electrostatic force-inducing ink jet head is a roll-to-roll printing system for fine pattern printing.

The method according to claim 1,
The first and second EPCs
An EPC roller provided at the upper and lower portions of the position where the printed material is fed;
A position sensor installed on both sides of the lower end of the EPC roller to detect an edge of the printed material; And
And a controller for receiving a sensing signal of the position sensor and providing a driving signal to the cylinder, wherein the EPC roller is tilted in an anteroposterior direction to correct an angle Cylinder control box
Wherein the electrostatic force-inducing ink jet head is a roll-to-roll printing system for fine pattern printing.

3. The method according to claim 1 or 2,
The ESD head
A head provided with a nozzle for ejecting a Ni ink droplet on a printing material;
A bracket for fixing both ends of the head;
An ink chamber provided at an upper end of the head to supply ink to the nozzle;
A head angle adjusting device installed at a rear end of the ink chamber for adjusting the horizontal, tilting, and yawing angles of the head; And
A head height adjusting device installed at a rear end of the head angle adjusting device for adjusting a height of the head,
Wherein the electrostatic force-inducing ink jet head is a roll-to-roll printing system for fine pattern printing.

The method of claim 3,
(+) And (-) electrodes connected to the ink chamber of the ESD head and the print material, respectively;
A regulator for filtering air flowing into the ink chamber from outside;
A pressure regulator for regulating the filtered air to a constant pressure;
A manisk control unit having a manifold for changing a water level by receiving a bias voltage and a pulse voltage from outside;
An ink supply control unit which receives a signal from the manifold control unit to change the manifold and supplies ink to the nozzle;
A waveform generator for generating a pulse;
A high voltage generator for receiving a power supply from the outside to generate a high bias voltage; And
A switching voltage device (not shown) for applying a pulse voltage generated from the waveform generator and a bias voltage generated from the high voltage generator to the (+) (-) electrode connected to the ink chamber 36 and the work stage 8,
Wherein the electrostatic force-inducing ink jet head is a roll-to-roll printing system for fine pattern printing.

The method according to claim 1,
The curing device
A support frame;
A heat dissipation cover installed in a box shape at the lower end of the support frame to block heat emission;
A heat source providing means for fixing the surface of the ink to both sides of the heat dissipation cover so as to minimize the spread of the ink after the Ni ink droplet is printed on the printing material; And
And the other end is installed on the heat dissipation cover to adjust the height of the heat source providing means interlocked with the heat dissipation cover,
Wherein the electrostatic force-inducing ink jet head is a roll-to-roll printing system for fine pattern printing.

6. The method of claim 5,
Wherein the heat source providing means is a halogen lamp. &Lt; RTI ID = 0.0 > 11. < / RTI >