KR20230154612A - inkjet head cleaning device and method of cleaning inkjet head using the same - Google Patents

Abstract

The present invention relates to an inkjet head cleaning device, the inkjet head cleaning device comprising: an ultrasonic cleaning unit containing a cleaning liquid for immersing a nozzle portion of an inkjet head and having an ultrasonic frequency set to clean the nozzle portion by applying vibration to the cleaning liquid; and a head driving unit that moves the inkjet head up and down so that the nozzle part can be repeatedly immersed in the cleaning liquid at a predetermined cycle. Includes.

Description

Inkjet head cleaning device and method of cleaning inkjet head using the same {inkjet head cleaning device and method of cleaning inkjet head using the same}

The present invention relates to an inkjet head cleaning device and an inkjet head cleaning method using the same. More specifically, it relates to an inkjet head cleaning device that can efficiently clean and manage an inkjet head, and an inkjet head cleaning method using the same.

In the manufacture of flat display devices such as liquid crystal display devices and organic EL devices, a process of applying ink to form an alignment film, color filter, etc. can be performed. Application of ink can mainly be achieved by using an inkjet system capable of ejecting ink onto a substrate. At this time, the inkjet system is provided in the substrate processing device. The inkjet process using such an inkjet system is one of the major technologies, and has become an important core technology in the high value-added display industry, where production is possible at room temperature and in the air, surpassing the production concept of vacuum deposition.

However, inkjet printers based on a solution process cannot avoid clogging of the nozzle area that occurs during long-term use when using inkjet heads and ink. In this case, if the inkjet head is not managed in the inkjet process, there is a problem that the quality of the product is deteriorated due to misplacement or non-ejection of ink that occurs when ink is deposited.

Accordingly, in the past, ink was simply pushed out until the ink ejected from the nozzle part of the inkjet head was maintained, or maintenance work based on the discharge of residual ink through prior coalescence operation before the main process was repeatedly performed. However, when there is no improvement, the inkjet head is replaced, but this has the problem of delaying the inkjet process equipment and causing expensive inkjet head consumption costs.

The present invention is intended to solve various problems including the problems described above, and its purpose is to provide an inkjet head cleaning device with improved cleaning efficiency and cleaning power for the nozzle portion of the inkjet head, and an inkjet head cleaning method using the same.

However, these tasks are illustrative and do not limit the scope of the present invention.

According to one aspect of the present invention, an inkjet head cleaning device is provided.

The inkjet head cleaning device includes an ultrasonic cleaning unit containing a cleaning liquid for immersing the nozzle portion of the inkjet head, and having an ultrasonic frequency set to clean the nozzle portion by applying vibration to the cleaning liquid; and a head driving unit that moves the inkjet head up and down so that the nozzle unit can be repeatedly immersed in the cleaning liquid at a predetermined cycle. Includes.

It may further include a liquid injection unit disposed on an upper portion of the inkjet head and injecting a cleaning liquid under positive pressure toward the nozzle unit.

The ultrasonic cleaning unit may be provided so that the ultrasonic frequency is adjusted according to the particle size of the ink remaining in the nozzle unit.

The ultrasonic cleaning unit may include an inlet through which the cleaning liquid flows, a water level sensor that detects the water level of the cleaning liquid, and a drain through which an amount of cleaning liquid exceeding the water level is discharged.

The liquid injection unit may include a pipe connected to the nozzle unit, and may be provided to inject the cleaning liquid into the nozzle unit through the pipe.

It may further include a pump provided to circulate the cleaning liquid inside.

The cleaning liquid may include cleaning liquid or ink.

According to another aspect of the present invention, an inkjet head cleaning method is provided.

The inkjet head cleaning method includes the steps of (a) containing a cleaning solution for immersing the nozzle part of the inkjet head inside the ultrasonic cleaning unit; (b) setting an ultrasonic frequency in the ultrasonic cleaning unit and applying vibration to the cleaning liquid to clean the nozzle unit; and (c) moving the inkjet head up and down by a head driving unit so that the nozzle portion can be repeatedly immersed in the cleaning liquid.

The inkjet head cleaning method may further include the step of (d) injecting the cleaning liquid at positive pressure through the liquid injection unit toward the nozzle unit.

Step (a) includes introducing the cleaning solution through an inlet; Detecting the water level of the cleaning liquid using a water level sensor; and discharging an amount of washing liquid exceeding the water level through a drain.

Step (b) may include adjusting the ultrasonic frequency according to the particle size of the ink remaining in the nozzle unit.

The step (d) may include circulating the cleaning liquid internally through a pump.

According to one embodiment of the present invention as described above, not only can the cleaning effect be improved by periodically moving the inkjet head up and down, but also the cleaning power can be strengthened by cleaning the nozzle portion according to the ultrasonic frequency.

Accordingly, it is possible to implement an inkjet head cleaning device that can improve mass production yield by reducing the cost of consuming expensive inkjet heads and the time required to stop the equipment accordingly.

Of course, the scope of the present invention is not limited by this effect.

1 is a plan view showing a treatment liquid application equipment according to an embodiment of the present invention.
FIG. 2 is a perspective view showing the treatment liquid discharge portion of the treatment liquid application equipment installed in FIG. 1.
Figure 3 is a plan view showing the treatment liquid discharge portion.
Figure 4 is a diagram showing an inkjet head cleaning device for cleaning the inkjet head of the processing liquid discharge unit according to an embodiment of the present invention.
Figure 5 is a diagram showing an inkjet head being cleaned when the head drive unit moves upward according to an embodiment of the present invention.
Figure 6 is a diagram showing an inkjet head being cleaned when the head drive unit moves downward according to an embodiment of the present invention.

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

The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and the following examples may be modified into various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete and to fully convey the spirit of the present invention to those skilled in the art. Additionally, the thickness and size of each layer in the drawings are exaggerated for convenience and clarity of explanation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will now be described with reference to drawings that schematically show ideal embodiments of the present invention. In the drawings, variations of the depicted shape may be expected, for example, depending on manufacturing technology and/or tolerances. Accordingly, embodiments of the present invention should not be construed as being limited to the specific shape of the area shown in this specification, but should include, for example, changes in shape resulting from manufacturing.

Figure 1 is a plan view showing a treatment liquid application equipment 1000 according to an embodiment of the present invention.

As shown in FIG. 1, the treatment liquid application equipment 1000 can apply the treatment liquid to an object using an inkjet method. For example, the object may be a glass substrate, a silicon substrate, a display substrate, or a color filter substrate of a liquid crystal display panel, and the treatment solution is red (R), green (G), and blue mixed with pigment particles in a solvent. It may be the ink in (B). Ink may be applied to the inner area of the black matrix arranged in a grid-like pattern on the color filter substrate.

The processing liquid application equipment 1000 includes a processing liquid discharge unit 10, a substrate transfer unit 20, a baking unit 30, a loading unit 40, an unloading unit 50, a processing liquid supply unit 60, and a control unit. Includes (70). The processing liquid discharge unit 10 and the substrate transfer unit 20 may be arranged in a line in the first direction (I) and adjacent to each other. The processing liquid supply unit 60 and the control unit 70 are disposed at a position facing the substrate transfer unit 20 with the processing liquid discharge unit 10 as the center, and the processing liquid supply unit 60 and the control unit 70 move in the second direction. (II) can be arranged in a row.

A loading unit 40 and an unloading unit 50 may be disposed at a position facing the processing liquid discharge unit 10 with the substrate transfer unit 20 as the center, and the loading unit 40 and the unloading unit 50 may be arranged in a row in the second direction (II). Additionally, the bake unit 30 may be disposed adjacent to one side of the substrate transfer unit 20 .

Here, the first direction (I) is the arrangement direction of the processing liquid discharge unit 10 and the substrate transfer unit 20, the second direction (II) is a direction perpendicular to the first direction (I) on the horizontal plane, and the third direction (II) is a direction perpendicular to the first direction (I) on the horizontal plane. Direction (III) is perpendicular to the first direction (I) and the second direction (II).

The substrate on which the processing liquid (ink) is to be applied may be brought into the loading unit 40 . The substrate transfer unit 40 may transfer the substrate loaded into the loading unit 40 to the processing liquid discharge unit 10 . The processing liquid discharge unit 10 may receive processing liquid from the processing liquid supply unit 60 and discharge the processing liquid on the substrate using an inkjet method. The substrate transfer unit 20 may transfer the substrate from the processing liquid discharge unit 10 to the bake unit 30 . The bake unit 30 may heat the substrate to evaporate the remaining liquid material (solvent) except for the solid component of the processing liquid (ink) discharged on the substrate.

The substrate transfer unit 20 may transfer the substrate from the baking unit 30 to the unloading unit 50 . The substrate onto which the processing liquid is applied may be unloaded from the unloading unit 50 . In addition, the control unit 70 controls the overall operation of the processing liquid discharge unit 10, the substrate transfer unit 20, the baking unit 30, the loading unit 40, the unloading unit 50, and the processing liquid supply unit 60. can be controlled.

FIG. 2 is a perspective view showing the treatment liquid discharge unit 10 of the treatment liquid application equipment 1000 installed in FIG. 1 , and FIG. 3 is a plan view showing the treatment liquid discharge unit 10 .

As shown in FIGS. 2 and 3, the processing liquid discharge unit 10 may include a substrate support unit 100, a head unit 200, a moving unit 300 and 400, and an ultrasonic cleaning unit 500. there is.

The substrate support unit 100 may have a support plate 110 on which the substrate S is placed. The support plate 110 may be a square-shaped plate. The rotation axis of the rotation drive motor 120 may be connected to the lower surface of the support plate 110. The rotation drive motor 120 may rotate the support plate 110 so that the substrate S placed on the support plate 110 is aligned at a preset position.

The support plate 110 and the rotation drive motor 120 may be moved linearly in the first direction (I) by the linear drive member 130. The linear drive member 130 may include a slider 132 and a guide member 134. The rotation drive motor 120 may be installed on the upper surface of the slider 132. The guide member 134 extends long in the first direction (I) from the central portion of the upper surface of the base (B). A linear motor (not shown) may be built into the slider 132, and the slider 132 may move linearly in the first direction (I) along the guide member 134.

The head unit 200 may discharge a processing liquid to the substrate S. The head unit 200 may include inkjet heads 210a and 210b and a bracket 220. One of the inkjet heads 210a and 210b may be installed on one side of the bracket 220 facing the first direction (I), and the other inkjet head 210b may be installed on the bracket 220. It may be installed on the other side facing the first direction (I).

Each inkjet head 210a, 210b may have a red (R) head 212, a green (G) head 214, and a blue (B) head 216.

The red (R) head 212, green (G) head 214, and blue (B) head 216 may be arranged in a row in the second direction (II), and are applied to the support plate ( The processing liquid can be discharged onto the substrate (S) placed on 110).

The moving units 300 and 400 may move the head unit 200 at the top of the path along which the support plate 110 moves. The first moving unit 300 can move the head unit 200 in a straight line in the first direction (I), and the second moving unit 400 can move the head unit 200 in the second direction (II) and the third direction (II). It can be moved in a straight line in direction (III).

The second moving unit 400 may include a horizontal support 410, a slider 420, and a head driver 430. The horizontal support 410 may be located on the upper part of the base B so that its longitudinal direction faces the second direction II. A guide rail 412 may be provided along the longitudinal direction of the horizontal support 410. The slider 420 may have a built-in linear motor (not shown), and the slider 420 may move linearly in the second direction (II) along the guide rail 412. The bracket 220 of the head unit 200 may be connected to the slider 420, and the inkjet heads 210a and 210b installed on the bracket 220 may be moved in the second direction (II) by the linear movement of the slider 420. Can move in a straight line. Meanwhile, a head driving unit 430 may be installed on the slider 420 to linearly move the bracket 220 of the head unit 200 in the third direction (III).

The first moving unit 300 may include a guide rail 310 and a slider 320. The guide rail 310 may have a longitudinal direction oriented in the first direction (I) and may be disposed on both edges of the upper surface of the base B with the guide member 134 of the substrate support unit 100 as the center. . The slider 320 has a built-in linear motor (not shown) and can move linearly in the first direction (I) along the guide rail 310. Both ends of the horizontal support 410 of the second moving unit 400 may be connected to the slider 320, respectively. The second moving unit 400 including the horizontal support 410 can be moved in the first direction (I) by the linear movement of the slider 320, and the second moving unit 400 can be moved in the second direction (I) by moving the slider 320 in a straight line. The head unit 200 connected to the moving unit 400 may be moved linearly in the second direction (II).

The head unit 200 can move linearly in the first direction (I), the second direction (II), and the third direction (III) by the first movement unit 300 and the second movement unit 400, The support plate 110 on which the substrate is placed can move linearly in the first direction (I) by the slider 132 and the guide member 134. When discharging the processing liquid on the substrate S, the head unit 200 is fixed at a preset position, and the support plate 110 on which the substrate is placed may be moved in the first direction I. In contrast, the support plate 110 on which the substrate is placed is fixed at a preset position, and the head unit 200 can be moved in the first direction (I).

The ultrasonic cleaning unit 500 may periodically clean the processing liquid discharge surface of the inkjet heads 210a and 210b, that is, the surface on which nozzles for discharging the processing liquid are formed. Typically, after the processing liquid discharge process for one substrate is performed, the processing liquid discharge surfaces of the inkjet heads 210a and 210b may be cleaned.

The ultrasonic cleaning unit 500 may be provided on one side of the substrate support unit 100 on the upper surface of the base B. The inkjet heads 210a and 210b are moved to the upper part of the ultrasonic cleaning unit 500 by the first moving unit 300 and the second moving unit 400, and are moved to the upper part of the ultrasonic cleaning unit 500 during the cleaning process. It can be moved in the first direction (I).

Figure 4 is a diagram showing an inkjet head cleaning device 1000' for cleaning the inkjet head of the processing liquid discharge unit according to an embodiment of the present invention.

Referring to FIG. 4, the inkjet head cleaning device 1000' largely includes an ultrasonic cleaning unit 500, a head driving unit 430, and a liquid injection unit 600.

The ultrasonic cleaning unit 500 accommodates the cleaning liquid 500a for immersing the nozzle parts of the inkjet heads 210a and 210b, and the ultrasonic frequency is set so that the nozzle part can be cleaned by applying vibration to the cleaning liquid 500a.

The ultrasonic frequency set in the ultrasonic cleaning unit 500 may have a fixed frequency or a variable frequency. For example, the ultrasonic frequency can be adjusted variably according to the particle size of the ink remaining in the nozzle unit. At this time, as long as the vibrator is configured to cause vibration by setting an ultrasonic frequency, there are no restrictions on its type, shape, number, and location.

The ultrasonic cleaning unit 500 may include an inlet, a water level sensor 530, and a drain 520. The inlet is a passage through which the cleaning liquid 500a flows into the ultrasonic cleaning unit 500. In order to accommodate the cleaning liquid 500a under a stable water level standard, the water level sensor 530 may detect the water level of the cleaning liquid 500a contained within the ultrasonic cleaning unit 500. The drain 520 is a passage through which the cleaning liquid 500a is discharged by the amount in which the water level detected by the water level sensor 530 exceeds the standard value.

Figure 5 is a diagram showing the inkjet head being cleaned when the head driving unit 430 moves upward according to an embodiment of the present invention, and Figure 6 is a diagram showing the head driving unit 430 according to an embodiment of the present invention. This is a diagram showing how the inkjet head is cleaned when moving in the downward direction.

The head driver 430 may move the inkjet heads 210a and 210b up and down so that the nozzle portions of the inkjet heads 210a and 210b can be repeatedly immersed in the cleaning liquid 500a.

The head driver 430 can move the inkjet heads 210a and 210b up and down at a predetermined cycle without any load being applied. At this time, the type, shape, number, and location of the head drive unit 430 are not limited as long as it is configured to mount the inkjet heads 210a and 210b and move them up and down in the Z-axis.

The liquid injection unit 600 is disposed on top of the inkjet heads 210a and 210b and injects the cleaning liquid 600a at positive pressure toward the nozzle portion of the inkjet heads 210a and 210b.

The liquid injection unit 600 may include a pipe 610 that is connected to and can be mounted on the nozzle portion of the inkjet head 210a and 210b. The cleaning liquid 600a injected through the liquid injection unit 600 may be injected into the nozzle portion of the inkjet heads 210a and 210b through the pipe 610. That is, the cleaning liquid 600a injected by positive pressure from the liquid injection unit 600 toward the nozzle portions of the inkjet heads 210a and 210b is discharged into the space containing the cleaning liquid 500a in the lower ultrasonic cleaning unit 500, thereby removing the nozzle. The cleansing of wealth can take place.

The liquid injection unit 600 may further include a pump 620 that circulates the injected cleaning solution 600a in a path through which the injected cleaning solution 600a flows. At this time, the pump 620 can be configured to smoothly clean the nozzle portion described above by strongly circulating the cleaning liquid 600a inside, for example, an impeller type-based pump 620 circulation system. .

The cleaning liquid 500a contained in the ultrasonic cleaning unit 500 and the cleaning liquid 600a injected through the liquid injection unit 600 according to an embodiment of the present invention may be, for example, a cleaning liquid or ink. There is no limitation on the type of liquid (500a, 300a) as long as it can clean the nozzle portion of the inkjet head (210a, 210b).

According to another aspect of the present invention, an inkjet head cleaning method is provided.

The inkjet head cleaning method is largely divided into (a) a cleaning liquid receiving step in the ultrasonic cleaning unit, (b) a nozzle cleaning step by vibration, (c) a driving step of the head driving unit 430, and (d) a liquid injection unit 600. ) includes the liquid injection step.

In step (a), the cleaning liquid 500a for immersing the nozzle portions of the inkjet heads 210a and 210b may be accommodated inside the ultrasonic cleaning unit.

More specifically, step (a) includes introducing the cleaning solution 500a through the injection port 510; Detecting the water level of the cleaning liquid (500a) through the water level sensor (530); and discharging the washing liquid 500a in an amount exceeding the water level through the drain 520.

The cleaning liquid 500a may flow into the ultrasonic cleaning unit 500 through the inlet and be accommodated therein. The cleaning liquid 500a can be accommodated under a predetermined reference level, and for this purpose, the water level sensor 530 can detect the water level of the cleaning liquid 500a accommodated inside the ultrasonic cleaning unit 500. The drain 520 is a passage through which the cleaning liquid 500a is discharged by the amount in which the water level detected by the water level sensor 530 exceeds the standard value.

In step (b), the nozzle portion immersed in the cleaning solution 500a can be cleaned by applying vibration to the cleaning solution 500a using an ultrasonic frequency set in the ultrasonic cleaning unit 500.

More specifically, the ultrasonic frequency can be adjusted variably according to the particle size of the ink remaining in the nozzle portion, for example.

In step (c), the inkjet heads 210a and 210b may move in a certain direction as the head driver 430, which mounts the inkjet heads 210a and 210b on the head driver 430, is driven.

More specifically, the inkjet heads 210a and 210b are moved up and down by the head driver 430 so that the nozzle portions of the inkjet heads 210a and 210b mounted thereon can be repeatedly immersed in the cleaning liquid 500a at a predetermined cycle. It can be exercised.

In step (d), the cleaning liquid 600a may be injected at positive pressure toward the nozzle unit through the liquid injection unit 600.

More specifically, the cleaning liquid 600a injected by positive pressure from the liquid injection unit 600 toward the nozzle portions of the inkjet heads 210a and 210b is discharged into the space containing the cleaning liquid 500a in the lower ultrasonic cleaning unit 500. By doing this, the cleaning process of the nozzle part can be performed.

Meanwhile, a step of internally circulating the cleaning solution 600a injected from the liquid injection unit 600 through the pump 620 in the flow path may be included.

More specifically, the pump 620 is configured to facilitate the cleaning process of the nozzle portion described above by strongly circulating the cleaning liquid 600a inside, for example, by the impeller type-based pump 620 circulation system. You can.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims.

Claims (12)

A cleaning solution for immersing the nozzle part of the inkjet head is accommodated, and the cleaning solution is vibrated.
an ultrasonic cleaning unit with an ultrasonic frequency set to clean the nozzle unit by applying an ultrasonic cleaning unit; and
a head driving unit that moves the inkjet head up and down so that the nozzle unit can be repeatedly immersed in the cleaning liquid at a predetermined cycle; Including,
Inkjet head cleaning device. According to claim 1,
It is disposed on the upper part of the inkjet head, and further includes a liquid injection unit that injects the cleaning liquid at a positive pressure toward the nozzle unit.
Inkjet head cleaning device. According to claim 1,
The ultrasonic cleaning unit is
Provided to adjust the ultrasonic frequency according to the particle size of the ink remaining in the nozzle portion,
Inkjet head cleaning device. According to claim 1,
The ultrasonic cleaning unit is
Comprising an inlet through which the cleaning liquid flows, a water level sensor that detects the water level of the cleaning liquid, and a drain through which an amount of cleaning liquid exceeding the water level is discharged,
Inkjet head cleaning device. According to claim 2,
The liquid injection part
It includes a pipe connected to the nozzle unit, and is provided to inject the cleaning liquid into the nozzle unit through the pipe,
Inkjet head cleaning device. According to claim 5,
Further comprising a pump provided to circulate the cleaning liquid therein,
Inkjet head cleaning device. According to claim 1,
An inkjet head cleaning device, wherein the cleaning solution includes a cleaning solution or ink. (a) The cleaning liquid that immerses the nozzle part of the inkjet head is stored inside the ultrasonic cleaning unit.
steps;
(b) Set the ultrasonic frequency in the ultrasonic cleaning unit to cause vibration in the cleaning liquid.
cleaning the nozzle portion by adding; and
(c) moving the inkjet head up and down by a head driving unit so that the nozzle part can be repeatedly immersed in the cleaning liquid at a predetermined cycle; Including,
Inkjet head cleaning method. According to claim 8,
(d) injecting the cleaning liquid at positive pressure through the liquid injection unit toward the nozzle unit; According to claim 8,
The step (a) is
Introducing the cleaning liquid through an injection port;
Detecting the water level of the cleaning liquid using a water level sensor; and
Including, discharging an amount of washing liquid exceeding the water level through a drain hole.
Inkjet head cleaning method. According to claim 8,
Step (b) above is
Including; adjusting the ultrasonic frequency according to the particle size of the ink remaining in the nozzle unit.
Inkjet head cleaning method. According to clause 9,
Step (d) above is
Comprising: circulating the cleaning liquid internally through a pump,
Inkjet head cleaning method.