KR20160031200A - Electro hydro dynamic inkjet apparatus - Google Patents

Abstract

According to one embodiment of the present invention, an electrohydrodynamic inkjet device comprises: a discharge head having at least one nozzle where an ink bubble is discharged; and an external electrode provided in a peripheral area of the nozzle or a processing substrate holder to apply a voltage, wherein an object to be discharged is placed in the processing substrate holder. The purpose of the present invention is to provide an electrohydrodynamic inkjet device accurately monitoring an ink discharge state.

Description

[0001] Electro hydro dynamic inkjet apparatus [0002]

The present invention relates to an electrohydraulic inkjet apparatus, and more particularly, to an electrohydraulic inkjet apparatus having an external electrode provided to surround a part of a nozzle of a discharge head.

An electro-hydrodynamic (EHD) inkjet printing system is an apparatus for electrostatic force acting on a fluid to cause electrification when a fluid is exposed to a strong local electric field and to perform patterning on a substrate using such electrical mutual attraction, Unlike a head of a conventional piezo inkjet printing system, it is a device that performs a pattern on a substrate based on the electrostatic attraction force induced by the electric charge injected into the ink.

As with conventional inkjet printing equipment, there is an advantage of minimizing material waste by ejecting the correct amount of ink at the correct location. Electrohydrodynamic inkjet technology is also called electrostatic inkjet technology, and it has an advantage that patterning of high viscosity and fine line width is possible compared with the conventional piezo inkjet method by using electrostatic force.

Also, it is a new next-generation printing technology evaluated because it has high process stability due to few nozzle clogging phenomena. These advantages are expected to be applied to various printing electronic industries such as RFID, process technology of solar cell, and manufacturing process technology of electronic device having flexible substrate.

For electrohydraulic inkjet, the meniscus shape should be controlled from the nozzle. For this, a slight positive pressure may be applied to the head using the height of the fluid height, a slight positive pressure may be applied using air pressure, or a syringe pump may be used. Therefore, the force for discharging is caused by the sum of the electric attractive force and the pressure applied to the fluid.

An electric field must be applied to eject ink from an electrohydraulic inkjet apparatus. The electric field can apply a high voltage (hundreds to several kV) direct current (DC) voltage. When a DC voltage is applied, cone jet type jetting is formed at the tip of the nozzle.

Although a method of applying electricity to a substrate holder and an ink jet head in an electrohydraulic inkjet apparatus is generally used, in repairing an actual display or the like, it may be costly to make the substrate holder metal and widen the insulation, In the case of a device equipped with a camera for inspection of the result, it is impossible to directly apply electricity to a transparent substrate holder or the like located under the substrate holder. To solve this problem, a structure has been disclosed in which electric power is applied to the head itself for jetting. However, the ring-shaped electrode on the outside of the head is effective, but the ink can not be sprayed until the ring and the substrate are brought close to each other. In this case, the voltage applied to the ring- .

Jetting control becomes impossible due to such substrate charging, and consistent jetting may become impossible. Therefore, the ring-shaped electrode must be grounded to prevent electrification.

However, when the ring-shaped electrode is grounded, electric power must be applied to the head in the form of pulse and DC voltage (pulse + DC). In the case of applying a grounding to the ring electrode, Effective jetting becomes difficult. Therefore, it is necessary to develop an electrohydraulic ink jet apparatus having a voltage applying method in which electricity is applied to a ring-shaped electrode, not to ground, while charging the substrate.

Related Art Prior art is disclosed in Korean Patent Registration No. 10-1348024 (entitled " Electrohydrodynamic Inkjet Device, Date of Registration: Dec. 27, 2013).

Disclosure of Invention Technical Problem [8] The present invention has been proposed in order to solve the above problems, and provides an electrohydraulic inkjet apparatus capable of accurately monitoring the ink discharge state without disturbing discharge monitoring using a camera.

The present invention provides an electrohydrodynamic inkjet apparatus capable of preventing electrification of objects such as substrates.

According to an aspect of the present invention, there is provided an electrohydraulic inkjet apparatus including a discharge head having at least one nozzle through which ink droplets are discharged, a processing substrate holder on which a discharge object is placed, And an external electrode which is provided on the substrate and applies a voltage.

The external electrode is provided to surround at least a part of the nozzle, and may include at least two electrode layers.

Wherein the outer electrode includes a first electrode layer provided to face the processing substrate holder and a second electrode layer laminated on the upper surface of the first electrode layer, and an end of the nozzle penetrates the first electrode layer and the second electrode layer .

The second electrode layer may be thicker than the first electrode layer.

The first electrode layer and the second electrode layer may have a first electrode hole and a second electrode hole passing through a lower end portion of the nozzle, respectively, and the second electrode hole may be formed larger than the first electrode hole .

The first electrode layer may include a transparent insulating layer and a transparent conductive electrode coating layer formed on at least one side of the upper surface or the lower surface of the insulating layer.

Wherein at least one of the adapters is formed of a metal or a conductor so as to be provided between the nozzle and the ink supply tube, or at least one of the nozzles The head can be mounted and mounted on a head holder made of metal or conductor.

A high voltage may be applied to either one of the adapters or the head holder so that ink in the nozzle can be charged.

As described above, the electrohydraulic inkjet apparatus according to the present invention simplifies the manufacturing process since no electric coating is required inside or outside the nozzle to apply electricity to the nozzle, and no electrode formation is required inside the nozzle. . Also, even when the nozzle is formed of a material such as glass, it can be easily replaced when the nozzle is broken.

In addition, the electrohydraulic ink jet apparatus according to the present invention can easily be replaced when the nozzle is broken because the nozzle is formed by the adapter structure. When a voltage to be applied to the nozzle is connected to the holding part of the head holder through which electricity is conducted, It is possible to inject electric charges into the ink without coating the electrodes or installing the electrodes inside the nozzles.

The electrohydraulic inkjet apparatus according to the present invention can make an electric field necessary for ejection by applying electricity to the external electrode surrounding the nozzle mounted on the head without installing the electrode or applying electricity.

Since the electrohydraulic inkjet apparatus according to the present invention forms an external electrode with a transparent material, it is possible to accurately monitor the ejection state of the nozzle or the ink sticking state using a camera.

The electrohydraulic inkjet apparatus according to the present invention can apply various types of electricity because the outer electrode of the nozzle is formed of a plurality of layers, and the ejection of ink can be effectively removed.

1 is a perspective view schematically showing a configuration of an electrohydraulic inkjet apparatus according to an embodiment of the present invention.
Fig. 2 is a view showing an exemplary manner of applying electricity to the ink-jet apparatus according to Fig.
3 is a perspective view illustrating an ejection head and an external electrode of an electrohydraulic inkjet apparatus according to an embodiment of the present invention.
FIG. 4 is a view showing an external distribution electrode according to FIG. 3. FIG.
5 is a perspective view showing a modified example of the external electrode according to FIG.
6 is a view schematically showing the configuration of an external electrode of the electrohydraulic inkjet apparatus according to Fig.
7 is an exploded perspective view showing the discharge head of the ink jet apparatus according to Fig.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

FIG. 1 is a perspective view schematically showing the configuration of an electrohydraulic inkjet apparatus according to an embodiment of the present invention, FIG. 2 is a view exemplarily showing a method of applying electricity to the inkjet apparatus according to FIG. FIG. 4 is a view showing an external electrode according to an embodiment of the present invention, FIG. 5 is a view showing a modification of the external electrode according to FIG. Fig. 6 is a schematic view showing a configuration of an external electrode of an electrohydraulic inkjet apparatus according to Fig. 5, and Fig. 7 is an exploded perspective view showing an ejection head of the inkjet apparatus according to Fig.

1 to 3, an electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention includes an ejection head 120 having at least one nozzle 125 through which ink droplets are ejected, An external electrode 220 provided to surround a part of the nozzle 125 of the ejection head 120, an external electrode 220 facing the nozzle 125 and printed with ink droplets ejected from the nozzle 125, An arbitrary waveform generator 150 for generating a second voltage to be applied to the ejection head 120, an arbitrary waveform generator 150 for applying a first voltage to the external electrode 220, A voltage amplifier 160 connected to the power supply 140 and the arbitrary waveform generator 150 for amplifying the second voltage and applying the second voltage amplified to the discharge head 120, When the first voltage or the second voltage is applied to the discharge head 120, It may include a control unit 170 for controlling the state to be applied to the outer electrode (220).

A purge / suction controller 110 (Purge / Suction Controller) for injecting or supplying ink may be connected to the discharge head 120. The purge / suction controller 110 may control the injection of ink into the discharge head 120 or the nozzle 125 or may control the amount of ink to be supplied. For this, the purge / suction controller 110 may be connected to the controller 170.

A discharge object 130 is positioned below the discharge head 120 or the nozzle 125, and a pattern to be printed on the object 130 is printed. Here, the object 130 may be a substrate on which a pattern is printed. As described above, it is preferable that the processing substrate holder 131, on which the object 130 such as a substrate is placed or fixed, so that a voltage capable of discharging electric field can be applied to the object 130 is formed of a conductor. Here, the object 130 such as a substrate can be fixed to the substrate processing holder 131 by using a vacuum chuck (not shown). If the electrodes are provided around the discharge head 120 to form an electric field for discharging the discharge head 120 itself, the processing substrate holder 131 need not be a conductor.

The discharge head 120 / nozzle 125 or the process substrate holder 131 can be moved in the X-axis or Y-axis direction so as to print a complicated pattern, and a driving unit (not shown) . The driving unit may be formed in an XYZ stage or the like.

The electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention is configured such that a voltage applied to the ejection head 120 / nozzle 125 and a voltage applied to the object or the external electrode 220 are separated have. 1, a power supplier 140 is connected to the external electrode 220, and a waveform generator 150 (Function Generator) is connected to the discharge head 120 / ) Or a voltage amplifier 160 (Voltage Amplifier) are connected.

The control unit 170 separates the voltage applied to the ejection head 120 and the nozzle 125 from the voltage applied to the external electrode 220 or controls the voltage applied to the ejection head 120 / Or the second voltage may be applied to the external electrode 220, the other one of the first voltage and the second voltage may be applied.

As described above, it is possible to reduce the cost of the electrohydraulic inkjet apparatus by separating the voltage applied to the discharge head 120 / the nozzle 125 and the external electrode 220. That is, the inkjet apparatus 100 can be driven using a low-cost power supply and a low-cost voltage amplifier.

The power supplier 140 can use a low-cost power supplier and generates a DC voltage to apply a DC voltage and a pulse to the external electrode 220. At this time, the DC voltage applied to the power supply 140 may be about several hundreds (V) to several thousands (V).

The operation of the arbitrary waveform generator 150 is controlled by the controller 170, and a desired waveform can be generated by communicating with the controller 170 using the USB. The waveform generated from the arbitrary waveform generator 150 may be amplified through the voltage amplifier 160 by about 1000 times and applied to the ejection head 120 / nozzle 125. Unlike the prior art, the voltage amplifier 160 according to an embodiment of the present invention uses a low-cost amplifier.

The control unit 170 of the electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention separates the voltage applied to the discharge head 120 and the voltage applied to the external electrode 220, When one of the first voltage and the second voltage is applied to the discharge head 120, the other of the first voltage and the second voltage is applied to the external electrode 220, 220 may include at least two electrode layers stacked.

A voltage equal to the voltage applied to the nozzle 125 may be applied to the external electrode 220 or another voltage may be applied to the external electrode 220. When a voltage different from that of the nozzle 125 is applied to the external electrode 220, for example, a voltage in the form of a DC voltage (DC) or a pulse is applied to the external electrode 220 as shown in FIG. 2 . In this way, the type, shape, size, etc. of the voltage applied to the external electrode 220 can be controlled or determined by the controller 170.

3 is a perspective view illustrating an example of a discharge head 120 and an external electrode 220 used in an electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention. 3, the ejection head 120 may be provided in a form attachable or detachable to a head holder 121a provided in a holder mounting portion 124 provided in a frame (not shown) of the apparatus 100. [

The ejection head 120 and the head holder 121a may be formed of a conductor or a metal so as to apply a voltage or electric power to the ejection head 120 or the nozzle 125, have. Electricity or voltage may be applied to the discharge head 120 and the nozzle 125 by connecting the power supply line 201 to a power connection part (not shown) formed on one side of the head holder 121a.

The holding portion 120a of the discharge head 120 may be inserted into the head holder 121a to receive a voltage from the head holder 121a. Here, the holding part 120a is also formed of a conductor such as a metal.

A camera for observing the ink discharge state at the end of the nozzle 125 and a state in which the ink is stuck on the object 130 (see FIG. 4) placed on the processing substrate holder 131 is provided on one side of the discharge head 120 5, reference numeral 300) may be provided. The illumination section 250 may be connected to the illumination frame 251 and the illumination frame 251 may be connected to the holder mounting section 124.

The electrohydraulic inkjet apparatus 100 according to an exemplary embodiment of the present invention may include an external electrode 220 provided at an end of the nozzle 125 or surrounding the end of the nozzle 125 have. By applying separate voltages to the external electrode 220 and the discharge head 120, it is possible to realize an electrohydrodynamic ink jet and to prevent the object 130 from being charged. Hereinafter, the external electrode 220 will be described in detail.

In Fig. 3, reference numeral 202 denotes an ink supply tube for supplying ink to the discharge head 120.

As shown in FIG. 3, a ring-shaped external electrode 220 may be additionally provided outside the end of the nozzle 125. In this case, it is not necessary to apply electricity to the object 130 at this time. There are various advantages if electricity is not applied to the object 130. For example, ink can be ejected without being sensitive to the distance between the object to be repaired such as a substrate and the ejection head 120, the structure of the inkjet apparatus can be simplified, and the apparatus can be easily added to equipment having other functions, Can be implemented. For example, there is an advantage that a fine pattern can be drawn by simply attaching a head module so that an inspection apparatus of a display can perform a repair function.

As described above, in the discharge head having the conventional external electrode, if electricity is applied to the ring-shaped external electrode, there is a problem that jetting may occur due to electrification on the substrate (repair object) (Grounding) process, DC + Pulse electricity is applied to the discharge head, which is not electrically efficient, and spraying of the ink is likely to occur. Therefore, in the present invention, the discharge head and the ring-shaped external electrode have the same polarity or different electric potentials, but are prevented from being charged to the external electrode through the ground. In the case of an external electrode having an electrode, the other electrode may be grounded to prevent electrification of the object 130. In this case, .

However, when there is an external electrode, the ejection control is advantageous as the nozzle passing hole 222 formed in the external electrode is made smaller. However, since the external electrode 220 having a small hole is difficult to monitor the ink jetting using a camera, it is possible to use an electrode made of transparent material such as ITO (Indium Tin Oxide) film and an insulating material, It is preferable to form the hole 222 formed in the hole 220 so that the diameter is at least 2 mm or more and 2 cm or less.

FIG. 4 shows an example of the ring-shaped external electrode 220. The external electrode 220 may be formed in an arc shape to avoid interference with a structure such as the discharge head 120. An electrode hole 222 through which an end of the nozzle 125 passes may be formed at one end. If the external electrode 220 is made of a transparent material, the size of the electrode hole 222 may be reduced, and the thickness of the electrode hole 222 may be reduced by using a camera. Can be monitored. That is, if the outer electrode 220 is made of a transparent material such as an ITO film, jetting monitoring at the end of the nozzle 125 can be performed using a camera even if the size of the electrode hole 222 is small. The size can be reduced.

Meanwhile, the external electrode 220 may have a structure in which three electrode layers 221a, 221b, and 221c are stacked as shown in FIG. 4 (d). Here, the first electrode layer 221a and the third electrode layer 221c are electrode layers and the second electrode layer 221b therebetween is an insulating layer. At this time, the third electrode layer 221c on the side of the object 130 is grounded to prevent electrification of the object 130, and a voltage having a different polarity is applied to the nozzle 125 and the first electrode layer 221a can do.

It is preferable that the end of the nozzle 125 is provided so as not to completely pass the external electrode 220.

5 and 6 show a modified example of the external electrode 220. In FIG. The external electrode 220 according to the modification shown in FIGS. 5 and 6 includes a first electrode layer 221 provided to face the object 130 or the processing substrate holder 131, And an end of the nozzle 125 may be formed so as to pass through the first electrode layer 221 and the second electrode layer 231. The second electrode layer 231 is formed on the first electrode layer 221 and the second electrode layer 231,

Unlike the external electrodes shown in FIG. 4, the external electrodes shown in FIGS. 5 and 6 may be formed of two electrode layers. The first and second electrode layers 221 and 231 forming the external electrode 220 may be stacked vertically along the longitudinal direction of the nozzle 125 and may have different thicknesses.

Referring to FIG. 6, an electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention includes an ejection mechanism for ejecting ink at an end of a nozzle 125 or ejecting ink droplets The observation camera 300 may be provided on one side of the head 120. The external electrodes 220 are formed with electrode holes 222 and 232 through which the ends of the nozzles 125 are inserted. The external electrodes 220 are formed on the outer surface of the observation camera 300, depending on the sizes of the electrode holes 222 and 232, and the thicknesses of the first and second electrode layers 221 and 231. [ May or may not observe the tip of the nozzle 125.

More specifically, a thicker electrode of 1 mm or more is required for the external electrode 220 to sufficiently provide the voltage field. When the electrode is thick, the camera 300 hides the tip of the nozzle 125 to be observed. In order to smoothly discharge the ink from the nozzle 125, the size of the electrode holes 222 and 232 must be small so that the electric field is large and the ink is well discharged. Even if the size of the electrode holes 222 and 232 is small, The external electrode 220 covers the nozzle 125 and the camera 300 can not observe the tip of the nozzle 125. In order to observe the camera 300, the size of the electrode holes 222 and 232 must be at least about 10 to 15 mm. In this case, the ink discharge may be difficult.

Therefore, in the inkjet apparatus 100 according to the embodiment of the present invention, the external electrode 220 has a thickness such that the camera 300 does not disturb the observation of the end of the nozzle 125, .

The external electrode 220 may be formed by forming the second electrode layer 231 thicker than the first electrode layer 221 so that the voltage field is sufficiently applied to the external electrode 220, Can be prevented from being disturbed.

It is preferable that the electrode layer which is close to or stacked below the object 130 is formed thinner than the electrode layer on which the electrode layer is stacked. Here, the second electrode layer 232, which is formed thick, preferably has a thickness of 1 mm or more.

On the other hand, the thin first electrode layer 221 may be formed of a transparent material, which enables the camera 300 to observe the end of the nozzle 125. Even if the first electrode layer 221 is formed of a transparent material, the sizes of the electrode holes of the first electrode layer 221 and the electrode holes of the second electrode layer 231 must be different from each other so that the camera 300 can be observed.

A first electrode hole 222 and a second electrode hole 232 may be formed in the first electrode layer 221 and the second electrode layer 231 to pass through the lower end of the nozzle 125, The second electrode hole 232 may be larger than the first electrode hole 222.

Since the thick first electrode layer 231 is formed of a non-transparent material, if the size of the first electrode hole 232 is small, the camera 330 can not observe the nozzle 125. Therefore, the first electrode hole 232 should be relatively larger than the second electrode hole 232. On the other hand, since the second electrode layer 221 is thinly formed of a transparent material, the camera 300 can be observed even if the size of the second electrode hole 222 is small.

The first electrode layer 221 formed of a thin electrode layer includes a transparent insulating layer 221b and transparent conductive electrode coating layers 221a and 221c formed on at least one side of the upper surface or the lower surface of the transparent insulating layer 221b (See FIG. 4 or FIG. 6).

Here, the transparent conductive electrode coating layers 221a and 221c may include ITO (Indium Tin Oxide, Indium Tin Oxide, Film, or ITO).

6, the first electrode layer 221, on which the transparent conductive electrode coating layer 221a is formed on the transparent insulating layer 221b, is formed on the transparent conductive electrode coating layer 221a, A voltage equal to the voltage applied to the electrode layer 231 may be applied. When the first electrode layer 221 is formed of two layers of the transparent conductive electrode coating layer 221a and the transparent insulating layer 221b, the transparent electrode layer 221b is grounded and the transparent conductive electrode coating layer 221a is grounded. (For example, pulse and DC) having different polarities from each other.

4 (d), the first electrode layer 221 formed on the bottom surface of the transparent conductive layer 221b may include the transparent conductive electrode coating layer 221c, A voltage different from a voltage applied to the second electrode layer 231 may be applied. For example, when a different voltage is applied to the first electrode layer 221 and the second electrode layer 231, the transparent conductive electrode coating layer 221c of the first electrode layer 221 may be grounded.

As described above, the voltage applied to the first electrode layer 221 may be the same as or different from the voltage applied to the second electrode layer 231.

The electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention includes the external electrode 220 described above so that a drop of ink is generated when a pulse voltage is applied to the external electrode 220. [ This enables drop on demand.

7, a discharge head 120 of an electrohydraulic inkjet apparatus 100 according to an embodiment of the present invention is shown.

7, the discharging head 120 includes a nozzle 125 formed at an end thereof, a first adapter 120c to which one end of the nozzle 125 is connected, a third adapter (not shown) connected to the first adapter 120c A holding part 120g connected to the rear end of the third adapter 120e and inserted into the head mounting part 204 and an ink supply tube 202 connected to the holding part 120g.

The connection between the tubing for ink supply and the metal adapter of the nozzle is made of metal and fitted into the metal head holder.

The end of the nozzle 125 may be formed to be sharp so as to be advantageous for jetting ink. The nozzle 125 may be fitted to the first adapter 120c and connected to the holding part 120g. The surface of the first adapter 120c is formed with fine irregularities or knurled so that the operator can easily grasp the first adapter 120c and remove it from the third adapter 120e.

The second adapter 120d can be fitted between the first adapter 120c and the third adapter 120e. At this time, the first adapter 120c and the third adapter 120e are screwed together. At this time, the second adapter 120d, which is located between the first adapter 120c and the third adapter 120e, As shown in FIG. One end of the nozzle 125 passes through the first adapter 120c and is fitted into the second adapter 120d. Since the second adapter 120d is compressed when the first adapter 120c and the third adapter 120e are screwed together, the nozzle 125 can be fixed to the first adapter 120c without moving.

The bottleneck 120f may be formed at the rear end of the third adapter 120e. At the front end of the holding part 120g, a fitting part 120j to be fitted in the bottleneck part 120f may be formed. It is preferable that the fitting portion 120j is fastened to the bottleneck portion 120f by an interference fit method. A tubing connector 202a for connecting the ink supply tube 202 and the holding portion 120g is provided at the rear end of the holding portion 120g. The tubing connector 202a may be connected to the holding portion 120g by a screw fastening method.

The holding portion 120g made of a conductive material is a portion inserted into a head mounting hole (not shown) formed in the head holder 121a and is a portion directly contacting the head mounting portion 204. [ That is, the power applied to the head holder 121a in the state where the holding part 120g and the head mounting hole are in contact with each other can be transmitted to the ink through the holding part 120g. That is, the holding portion 120g functions similarly to the electrode for applying power to the ink.

The ink supply tube 202 may be connected to the rear end of the holding portion 120g. One end of the ink supply tube 202 may be connected to the holding portion 120g and the other end of the ink supply tube 202 may be connected to an ink reservoir (not shown).

The ink supply tube 202 may not only supply the ink stored in the ink reservoir to the nozzle 125 but also supply the ink to the nozzle 125 without being connected to the ink reservoir. For example, when a nozzle formed of a syringe type is used, connection with the ink reservoir is not necessary.

Any one of the first to third adapters 120c, 120d, and 120e or the holding portion 120g may be formed of a conductor or a metal having good electrical conductivity. When any one of the first to third adapters 120c, 120d and 120e or the holding part 120g is formed of a conductor, power may be applied to the ink in the nozzle 125 by only connecting with the head holder 121a. The ink can be injected in a charged state by providing the voltage applying unit (not shown), and the electrohydraulic inkjet can be realized by the potential difference formed between the processing substrate holder 131 and the discharging head 120.

In other words, a high voltage may be applied to any one of the first to third adapters 120c, 120d, and 120e or the holding portion 120g and the head mounting portion 204 to charge the ink in the nozzle 125. [

The inkjet apparatus according to the present invention is expected to be capable of generating a significant ripple effect in the equipment / material / process / software industries required in the entire display industry as a convergence technology covering all fields of repair equipment / material / process / software.

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 understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

100: electrohydraulic ink jet device
110: purge / suction controller 120: discharge head
125: nozzle 130:
140: power supply 150: arbitrary waveform generator
160: voltage amplifier 170:
220: external electrode 221: first electrode layer
222: first electrode hole 231: second electrode layer
232: second electrode hole

Claims (8)

An ejection head having at least one nozzle through which ink droplets are ejected; And
And a processing substrate holder on which the object is placed or an external electrode provided around the nozzle to apply a voltage.
The method according to claim 1,
Wherein the external electrode is provided to surround at least a portion of the nozzle, and includes at least two electrode layers.
3. The method of claim 2,
Wherein the external electrode includes a first electrode layer provided to face the processing substrate holder and a second electrode layer stacked on the upper surface of the first electrode layer,
Wherein an end of the nozzle is formed to pass through the first electrode layer and the second electrode layer.
The method of claim 3,
Wherein the second electrode layer is thicker than the first electrode layer.
The method of claim 3,
Wherein the first electrode layer and the second electrode layer are respectively formed with first electrode holes and second electrode holes passing through a lower end portion of the nozzle,
Wherein the second electrode hole is formed to be larger than the first electrode hole.
5. The method of claim 4,
Wherein the first electrode layer comprises a transparent insulating layer and a transparent conductive electrode coating layer formed on at least one surface of the upper or lower surface of the insulating layer.
3. The method according to claim 1 or 2,
The discharge head
And at least one adapter to which one end of the nozzle and the nozzle formed at the end are connected,
Wherein at least one of the adapters is formed of a metal or a conductor and is provided between the nozzle and the ink supply tube or mounted on a head holder mounted with the discharge head and formed of a metal or a conductor.
8. The method of claim 7,
Wherein a high voltage is applied to either one of the adapters or the head holder to charge the ink in the nozzle.

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