KR20080046763A - Device for jetting of thin film liquid - Google Patents

Abstract

An ejection device of a thin film liquid is provided to correct a discharge amount of a head unit by disposing head compensation units at the side parts of a head unit, and to minimize the installation space and cost of the head compensation units by placing the head compensation units within the ejection device. An ejection device(100) of a thin film liquid includes: a supply tank filled with a thin film liquid; a head unit(400) which is connected with the supply tank via a supply line, and has plural discharge heads capable of discharging the thin film liquid onto a substrate(20) through plural nozzles to form thin film; and head compensation devices(500) which are united with the supply line at the side parts of the head unit, and have a compensation head that corrects a discharge amount of the thin film liquid and is replaced with the discharge head.

Description

Thin film liquid discharging device {DEVICE FOR JETTING OF THIN FILM LIQUID}

1 is a plan view briefly showing a thin film liquid discharge apparatus according to an embodiment of the present invention.

FIG. 2 is a side view illustrating the thin film liquid discharging device of FIG. 1 in detail.

FIG. 3 is a side view illustrating the head unit and the head compensation device shown in FIG. 2 in detail.

4 is a plan view of the lower surface of the discharge head illustrated in FIG. 3.

FIG. 5 is a side view briefly showing another side of the thin film liquid discharging device shown in FIG. 1.

<Explanation of symbols for the main parts of the drawings>

10: thin film liquid 20: substrate

100: thin film liquid discharge device 200: storage tank

300: supply tank 400: head unit

410: discharge head 500: head correction device

510 calibration head 520 sealed chamber

530: first correction headline 540: discharge amount measuring unit

550: discharge amount correction unit 560: second correction headline

700: drain tank 800: nozzle inspection device

The present invention relates to a thin film liquid discharge device, and more particularly, to a thin film liquid discharge device including a head correction device capable of correcting the discharge amount of the discharge head.

In general, a liquid crystal display (LCD) includes a liquid crystal display panel including an array substrate, a color filter substrate, and a liquid crystal layer having liquid crystal molecules interposed between the array substrate and the color filter substrate to display an image. .

The liquid crystal display panel changes the transmittance of light supplied from the outside according to the alignment direction of the liquid crystal molecules so that an image of a gray scale desired by the user is displayed. Here, the alignment direction of the liquid crystal molecules changes according to the applied electric field. In this case, an alignment layer is formed on the inner surface of the array substrate and the color filter substrate of the liquid crystal display panel so as to change the alignment direction of the liquid crystal molecules.

In recent years, the alignment film has a tendency to be formed according to the ejection method applying the inkjet printer in the previous roller coating method. This is because the discharging method has advantages in that the item replacement time is shorter than the roller coating method, and the correspondence is excellent as the size of the array substrate or the color filter substrate is increased.

The thin film liquid ejecting apparatus according to the ejection method is connected to a supply tank filled with an alignment liquid forming an alignment film and a supply tank, and is configured as a core of ejection heads having a plurality of nozzles. Here, it is necessary for the discharge head to discharge a uniform discharge amount through the nozzle in order to form the alignment film in a constant thickness.

However, the discharge head has a problem in that the discharge amount is uneven due to long term use or transportation and maintenance in a supplier.

Accordingly, the present invention has been made in view of such a problem, and the present invention provides a thin film liquid ejecting apparatus having a head correction apparatus capable of correcting the ejection amount of the ejecting head.

The thin film liquid discharging device according to an aspect of the present invention described above includes a supply tank, a head unit, and a head correction device. The supply tank is filled with a thin film liquid. The head unit is connected through the supply tank and the supply line, and has a plurality of discharge heads for forming a thin film by discharging the thin film liquid to the substrate through a plurality of nozzles. The head correction apparatus has a correction head connected to the supply line at the side along the longitudinal direction of the head unit, and is replaced with the discharge head by correcting the discharge amount of the thin film liquid.

The head correction apparatus includes a closed chamber, a correction headline branched from the supply line and coupled to and separated from the correction head, a discharge amount measuring unit arranged in the closed chamber to measure the discharge amount of the thin film liquid, and the discharge amount measuring unit and the It is connected to the correction head, and further comprises a discharge amount correction unit for correcting the correction head by analyzing the discharge amount.

The correction headline includes a correction valve for opening and closing the thin film liquid, and a first correction head socket for coupling and separating the correction head. Thus, the correction head includes a second correction head socket coupled to and separated from the first correction head socket.

On the other hand, the head unit further comprises a discharge head line branched from the supply line and coupled to and separated from the discharge head.

The discharge amount measuring unit includes a storage container accommodating the discharged thin film liquid and an electronic scale measuring a mass of the storage container in which the thin film liquid is accommodated. Here, the discharge amount measuring unit may measure 350,000 to 450,000 drops per nozzle.

The hermetic chamber also includes a door portion for loading and unloading the calibration head.

On the other hand, the thin film liquid discharge device further comprises a nozzle inspection device for inspecting the state discharged from the nozzles of the discharge head.

The nozzle inspection apparatus includes a photographing unit which is disposed perpendicular to the longitudinal direction of the head unit to photograph a state in which the thin film liquid is ejected from the nozzles, and a detection unit which is connected to the photographing unit to detect a poor ejection of the nozzles. do.

The thin film liquid discharging device may further include a drain tank connected to the drain line extending from the supply line to drain the thin film liquid.

According to such a thin film liquid ejecting apparatus, a head correcting apparatus capable of automatically correcting the ejection amount of the correcting head is disposed on the side of the head unit, so that the ejecting head can be corrected by replacing the ejecting head having ejection failure.

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

1 is a plan view briefly showing a thin film liquid discharging device according to an embodiment of the present invention, Figure 2 is a side view showing the thin film liquid discharging device shown in FIG.

1 and 2, the thin film liquid discharging device 100 according to an embodiment of the present invention includes a storage tank 200, a supply tank 300, a head unit 400, and a head compensation device 500. Include.

Storage tank 200 varies from case to case, but generally has a capacity of about 3.5 liters. The storage tank 200 is filled with the thin film liquid 10. The thin film solution 10 may include, for example, a polyimide solution. The polyimide solution is used as an alignment liquid for forming an alignment film for guiding the direction of liquid crystal in a liquid crystal display device displaying an image using liquid crystal. Here, the alignment film is formed on the inner surface of the array substrate and the color filter substrate surrounding the liquid crystal.

The supply tank 300 is filled with the thin film liquid 10 supplied from the storage tank 200. The capacity of the supply tank 300 may be the same as or smaller than the storage tank 200. Both the storage tank 200 and the supply tank 300 have a common point that they are filled with the thin film liquid 10. On the contrary, the storage tank 200 simply receives the thin film liquid 10 from the outside and fills it regardless of its level, whereas the supply tank 300 supplies the thin film liquid 10 to the head unit 400 at a constant level. The difference is that there is a need to maintain a constant level at all times.

That is, the supply tank 300 is higher than the head unit 400 so that the thin film liquid 10 is automatically supplied to the head unit 400 by the level difference. Accordingly, when the water level level sensor is mounted on the supply tank 300 and the water level drops below a certain level, the supply tank 300 may automatically receive the thin film liquid 10 from the storage tank 200.

The head unit 400 is connected through the supply tank 300 and the supply line 310, and serves to substantially form a thin film on the substrate 20. Accordingly, the head unit 400 has a plurality of discharge heads 410 for discharging the thin film liquid 10 to the substrate 20. A plurality of nozzles are formed on the lower surface of the discharge heads 410, which will be described with reference to FIG. 4. Here, the thin film liquid discharge device 100 further includes a stage 600 on which the substrate 20 is disposed.

The discharge heads 410 are disposed in close contact with each other to uniformly discharge the thin film liquid 10 onto the substrate 20. In order to more reliably implement this function, the discharge heads 410 may be arranged to overlap each other by a predetermined length with respect to the same line. This is because, when the thin film liquid 10 is used as the alignment liquid, the pitch between the nozzles must be maintained at about 742 μm to form a uniform alignment film. At this time, the diameter of the nozzle may be about 120㎛.

The number of discharge heads 410 may be variously formed according to the width of the substrate 20. This means that the thin film can be formed by simply increasing the number of the discharge heads 410 according to the size of the substrate 20. That is, the thin film liquid discharge apparatus 100 of the present invention can basically flexibly respond to the size of the substrate 20.

In the discharging method, the thin film liquid 10 is generally supplied to the supply line and discharged. However, in order to facilitate the discharging operation as in the present embodiment, the thin film liquid 10 is drained through a drain line connected to the supply line. It can flow to the tank 700.

This is because when the thin film solution 10 is used as the alignment solution, the polyimide solution may be partially cured unless it is circulated. As a result, the discharge head 410 may receive the thin film liquid 10 from the supply line and discharge some of the thin film liquid 10, and then apply some of the thin film liquid 10 to the drainage line to flow to the drain tank 700. At this time, the thin film solution 10 collected in the drainage tank 700 may be used again or disposed through a separate purification process.

The head correction device 500 is disposed at the side along the longitudinal direction of the head unit 400. Here, the head correction device 500 may be disposed on both sides of the head unit 400, it may be disposed only on one side. The head correction device 500 is connected to the supply line 310 like the head unit 400. In detail, the head compensator 500 is connected in series with the head unit 400 on the supply line 310.

The head correction device 500 includes a correction head 510 having the same shape as the discharge head 410. The correction head 510 is replaced by the discharge head 410, which is corrected by the head correction device 500, and the discharge amount is unevenly discharged. The discharge head 410 thus replaced may be regarded as the correction head 510 again and corrected by the head correction apparatus 500, or discarded when a bad state is serious. In addition, the correction head 510 may be the discharge head 410 before the new mounting.

At this time, the non-uniform level of the discharge head 410 is within the error of about 3% compared to the discharge amount discharged from the preset reference value. Here, the level within about 3% is the minimum level that can stably form the print pattern in the printing process that can proceed after forming the thin film. In addition, this error is the range which an inspector can visually check and judge a thin film surface.

As described above, the thin film liquid discharging device 100 substantially includes the head correction device 500 at the side of the head unit 400 which discharges the thin film liquid 10 to the substrate 20 to form a thin film. The discharge amount of the unit 400 may be corrected. In addition, since the head compensator 500 is included in the thin film liquid discharge device 100, the installation space and the installation cost of the head compensator 500 may be minimized.

In addition, since the correction head 510 substantially corrected in the head correction apparatus 500 is connected to the same supply line 310 as the discharge head 410, it is possible to secure reliability of the discharge amount correction.

FIG. 3 is a side view illustrating the head unit and the head compensation device shown in FIG. 2 in detail.

2 and 3, the head correction apparatus 500 includes a closed chamber 520, a first correction headline 530, a discharge amount measuring unit 540, and a discharge amount correcting unit 550.

The hermetic chamber 520 is formed outside the head compensator 500 to serve to block the head compensator 500 from the outside. That is, when the correction head 510 is corrected in the head correction apparatus 500, the sealed chamber 520 is not influenced by external airflow. The sealing chamber 520 may include the supply line 310 to be sealed as in the present embodiment, or may be sealed except the supply line 310.

The first calibration headline 530 is branched in parallel from the supply line 310 to be coupled and separated from the calibration head 510. To this end, the first correction headline 530 includes a first correction valve 532 for opening and closing the thin film liquid 10, and a first correction head socket 534 for coupling and separating the correction head 510. . Accordingly, the correction head 510 also includes a second correction head socket 512 that is coupled to and separated from the first correction head socket 534.

The first and second correction head sockets 534 and 512 may be coupled and separated while having opposite male and female shapes. Alternatively, the first and second calibration head sockets 534 and 512 may be coupled in accordance with a hook coupling method. In this case, a sealing part may be formed between the first and second correction head sockets 534 and 512 to closely hold the thin film liquid 10.

Here, the head correction apparatus 500 may further include a second correction headline 560 connected in parallel from the drain line 710 connected to the storage tank 200 to circulate the thin film liquid 10. In this case, the second correction headline 560 may include a second correction valve 562 and a third correction head socket 564 which play the same role as the first correction headline 530. Accordingly, the correction head 510 may also include the same fourth correction head socket 514 as the second correction head socket 512.

Meanwhile, the head unit 400 further includes a first discharge headline 420 branched in parallel from the supply line 310 to be coupled to and separated from the discharge head 410. To this end, the first discharge headline 420 includes a first discharge valve 422 for opening and closing the thin film liquid 10, and a first discharge head socket 424 for coupling and separating the discharge head 410. . Accordingly, the discharge head 410 also includes a second discharge head socket 412 coupled to and separated from the first discharge head socket 424.

Similarly, the head unit 400 may further include a second discharge headline 430 connected in parallel from the drain line 710. In this case, the second discharge headline 430 may include a second discharge valve 432 and a third discharge head socket 434 which play the same role as the first discharge headline 420. Accordingly, the correction head 510 may also include the same fourth discharge head socket 414 as the second discharge head socket 412.

On the other hand, the hermetic chamber 520 includes a door portion 522 to load and unload the calibration head 510 which is coupled and separated from the first and second calibration headlines 530 and 560. The door 522 may have a hinge formed at one side thereof to open and close outward, or in addition to the sealed chamber 520, a guide groove may be formed to open and close according to a sliding method.

As such, the discharge unit 410 and the correction head 510 are coupled to and separated from the head unit 400 and the head compensator 500, so that the thin film liquid discharge device 100 in mass production needs to be stopped for a long time. It is possible to simply replace the corrected correction head 510 with the discharge head 410 of poor discharge. As a result, it is possible to shorten the correction time due to the discharge failure of the discharge head 410, thereby minimizing the production loss while improving the thin film formation quality of the substrate 20.

The discharge amount measuring unit 540 is disposed in the sealed chamber 520. The discharge amount measuring unit 540 measures the mass of the storage container 542 for storing the thin film liquid 10 discharged from the correction head 510 and the storage container 542 for storing the thin film liquid 10. And an electronic scale 544 for measuring the discharge amount. Here, the storage container 542 is preferably formed larger by a predetermined difference than the lower surface on which the nozzles of the correction head 510 are formed. This is to prevent leakage of the thin film liquid 10 discharged to the storage container 542.

The discharge amount measuring unit 540 measures about 350,000 drops to about 450,000 drops per nozzle of the correction head 510, and is preferably about 400,000 drops. Here, when the volume is calculated to about 400,000 drops may be about 125 pℓ. Specifically, the discharge amount measuring unit 540 measures the discharge amount four times for about 10 ms and 10 seconds for each nozzle.

The discharge amount corrector 550 is connected to the discharge amount measurer 540 and the correction head 510 outside the sealed chamber 520. The discharge amount corrector 550 analyzes the discharge amount to correct the correction head 510. In detail, the discharge amount corrector 550 compares the mass measured by the electronic scale 544 with a preset reference value and corrects the correction head 510 again based on this. At this time, as mentioned above, the error range of the discharge amount is within about 3%.

Since the discharge amount corrector 550 typically uses a piezoelectric element, the discharge amount corrector 550 may correct the discharge amount of the correction head 510 by adjusting the piezoelectric voltage applied to the piezoelectric element. Here, the discharge amount according to the piezoelectric voltage has a proportional characteristic.

That is, when only two piezoelectric voltages are applied and the discharge amount is measured, the discharge amount graph according to the piezoelectric voltage can be shown. By using such a graph, the operator may allow a desired discharge amount to be discharged from the correction head 510 in addition to the correcting operation. Alternatively, the discharge amount corrector 550 may correct the discharge amount using a solenoid valve capable of precise control.

FIG. 4 is a plan view of the lower surface of the discharge head shown in FIG. 3, and FIG. 5 is a side view schematically showing another side of the thin film liquid discharge device illustrated in FIG. 1.

3, 4, and 5, the thin film liquid ejecting apparatus 100 further includes a nozzle inspecting apparatus 800 for inspecting a state of ejection from the nozzles NZ1 to NZ2n of the ejection head 410. .

The nozzles NZ1 to NZ2n generally consist of two first and second rows N100 and N200. In the first row N100, the nozzles NZ1 to NZn are recognized as going from left to right, and in the second row N200, the nozzles NZn + 1 to NZ2n are recognized as going from right to left. This is in accordance with the nozzle order for measuring the discharge amount in the discharge amount measuring unit 540. Typically, the nozzles NZ1 to NZ2n may be about 64 in total for each discharge head 410.

The nozzle inspection apparatus 800 includes a photographing unit 810 and a detector 820. The photographing unit 810 is disposed perpendicular to the longitudinal direction of the head unit 400. The photographing unit 810 photographs a state in which the thin film liquid 10 is discharged from the nozzles NZ1 to NZ2n. In this case, a separate light is disposed in the photographing unit 810 to supply light to a location to be photographed. Alternatively, the nozzle inspection apparatus 800 may include a separate lighting unit. The photographing unit 810 may include, for example, a high resolution CCD camera.

The detector 820 is connected to the photographing unit 810. The detector 820 detects a discharge failure of the nozzles NZ1 to NZ2n. Accordingly, the nozzles NZ1 to NZ2n corresponding to the first and second rows N100 and N200 need to have a staggered structure. This is because the image photographed by the photographing unit 810 is a planar image.

Therefore, the thin film liquid ejecting apparatus 100 of the present invention may also include the nozzle inspecting apparatus 800, thereby detecting a poor ejection of each of the nozzles NZ1 to NZ2n.

Meanwhile, the stage 600 on which the substrate 20 is disposed may be connected to a separate moving device 900 to move along a direction perpendicular to the length direction of the nozzles NZ1 to NZ2n.

According to such a thin film liquid discharge device, the discharge amount of the head unit can be corrected by the thin film liquid discharge device having the head correction device on the side of the head unit which discharges the thin film liquid to the substrate to form the thin film. In addition, since the head compensator is included in the thin film liquid discharging device, the installation space and the installation cost of the head compensator can be minimized.

Further, in the head correction apparatus, the correction head to be substantially corrected is connected to the same supply line as the discharge head, thereby ensuring the reliability of the discharge amount.

Although the above description of the present invention has been described with reference to preferred embodiments of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described below. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (11)

Supply tank filled with thin film liquid; A head unit connected through the supply tank and a supply line, the head unit having a plurality of discharge heads to form a thin film by discharging the thin film liquid to a substrate through a plurality of nozzles; And And a head compensating device connected to the supply line at a side along the longitudinal direction of the head unit, the head compensating device having a correction head that is replaced with the discharge head by correcting the discharge amount of the thin film liquid. The method of claim 1, wherein the head correction device Airtight chamber; A correction headline branched from the supply line and coupled to and separated from the correction head; A discharge amount measuring unit disposed in the closed chamber to measure the discharge amount of the thin film liquid; And And a discharge amount correction unit connected to the discharge amount measurement unit and the correction head and analyzing the discharge amount to correct the correction head. The method of claim 2, wherein the correction headline A correction valve for opening and closing the thin film liquid; And A first calibration head socket for engaging and disengaging the calibration head, And the correction head comprises a second correction head socket coupled to and separated from the first correction head socket. 4. The thin film liquid discharge apparatus according to claim 3, wherein the head unit further comprises a discharge headline branched from the supply line and coupled to and separated from the discharge head. The method of claim 2, wherein the discharge amount measuring unit A storage container accommodating the discharged thin film liquid; And Thin film liquid discharge device, characterized in that it comprises an electronic scale for measuring the mass of the container containing the thin film liquid. The thin film liquid discharge apparatus according to claim 5, wherein the discharge amount measuring unit measures 350,000 to 450,000 drops per nozzle. 3. The thin film liquid ejecting apparatus according to claim 2, wherein the closed chamber includes a door portion for loading and unloading the correction head. The method of claim 2, And a nozzle inspection device for inspecting a state discharged from the nozzles of the discharge head. The method of claim 8, wherein the nozzle inspection device A photographing unit disposed perpendicular to the longitudinal direction of the head unit to photograph a state in which the thin film liquid is discharged from the nozzles; And And a detection unit connected to the photographing unit to detect a discharge failure of the nozzles. The thin film liquid discharge apparatus according to claim 1, further comprising a drain tank connected to the drain line extending from the supply line to drain the thin film liquid. The thin film liquid ejecting apparatus according to claim 1, wherein the thin film liquid comprises a polyimide solution.

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