APPARATUS FOR PROCESSING CHEMICAL LIQUID

The disclosure provides a chemical liquid supply apparatus including a chemical liquid storage tank storing a chemical liquid including a plurality of nanorods, a circulation pipe having both ends connected to the chemical liquid storage tank and including a first branch pipe and a second branch pipe, a classifier located at the second branch pipe and including a classification chip and a power supply, and a discharge pipe configured to discharge the chemical liquid to an outside of the circulation pipe, wherein the classification chip collects and releases nanorods of a certain size among the plurality of nanorods, the discharge pipe discharges the nanorods of the certain size to the outside before the nanorods of the certain size released by the classification chip are returned to the chemical liquid storage tank, and the power supply supplies an alternating current to the classification chip.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0142465, filed on Oct. 31, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

BACKGROUND

The disclosure relates to a chemical liquid supply apparatus, and more particularly, to a chemical liquid supply apparatus that may classify nanorods included in a chemical liquid.

2. Description of the Related Art

With further development in displays using quantum dot (QD) materials and organic light-emitting diodes (OLEDs), interest in quantum nano emitting diode (QNED) (or QD-inorganic LED) displays is increasing. QNEDs are the same as OLEDs in that quantum dot materials are used for color conversion, but QNEDs use inorganic LEDs, not OLEDs, as light-emitting devices that emit light incident on a quantum dot material, and particularly, a main feature of QNEDs is that inorganic LEDs are used in the form of nanorods which are dipoles. The nanorods used in QNEDs are nano-sized materials like nanoparticles but are named nanorods due to their high aspect ratio, which is a ratio of diameter to height, and because the nanorods used for QNEDs are manufactured in heights ranging from hundreds of nanometers to micrometers, sizes of nanorods have to be uniform compared to a quantum dot material dispersed in ink to which inkjet printing is applied.

SUMMARY

The disclosure provides a chemical liquid supply apparatus that may collect nanorods of a certain size and apply uniform nanorods on a substrate.

The disclosure provides a chemical liquid supply apparatus that may be used without replacing a foreign matter filter by releasing the collected nanorods.

In addition, objects to be achieved by the disclosure is not limited to the objects described above, and other objects may be clearly understood by those skilled in the art from the description below.

According to an aspect of the disclosure, a chemical liquid supply apparatus includes a chemical liquid storage tank storing a chemical liquid including a plurality of nanorods, a circulation pipe having both ends connected to the chemical liquid storage tank and including a first branch pipe and a second branch pipe, a classifier located at the second branch pipe and including a classification chip and a power supply, and a discharge pipe configured to discharge the chemical liquid to an outside of the circulation pipe, wherein the classification chip collects and releases nanorods of a certain size among the plurality of nanorods, the discharge pipe discharges the nanorods of the certain size to the outside before the nanorods of the certain size released by the classification chip are returned to the chemical liquid storage tank, and the power supply supplies an alternating current to the classification chip.

According to another aspect of the disclosure, a chemical liquid supply apparatus includes a chemical liquid storage tank storing a chemical liquid including a plurality of nanorods, a circulation pipe having both ends connected to the chemical liquid storage tank and including a main flow pipe and a plurality of branch pipes, a plurality of classifiers located at the plurality of branch pipes and each including a classification chip and a power supply, a plurality of discharge pipes configured to discharge the chemical liquid to an outside of the circulation pipe, and a plurality of control valves respectively located at the plurality of branch pipes and respectively adjusting flow rates of the chemical liquid flowing through the plurality of branch pipes, wherein the classification chip collects and releases nanorods of a certain size among the plurality of nanorods, the plurality of discharge pipes discharge the nanorods of the certain size to the outside before the nanorods of the certain size released by the classification chip are returned to the chemical liquid storage tank, and the power supply supplies an alternating current to the classification chip.

According to another aspect of the disclosure, a chemical liquid supply apparatus includes a chemical liquid storage tank storing a chemical liquid including a plurality of nanorods, a circulation pipe having both ends connected to the chemical liquid storage tank and including a main flow pipe and a plurality of branch pipes, a degassing device located at the circulation pipe and configured to remove air bubbles in the chemical liquid, a distribution measurer located at the chemical liquid storage tank and configured to measure a degree of distribution of the plurality of nanorods in the chemical liquid, a plurality of classifiers respectively located at the plurality of branch pipes and each including a classification chip and a power supply, a plurality of discharge pipes configured to discharge the chemical liquid to an outside of the circulation pipe, a plurality of control valves respectively located at the plurality of branch pipes and configured to adjust flow rates of the chemical liquid flowing through the plurality of branch pipes, a head configured to spray the chemical liquid onto a substrate, a supply pipe and a return pipe connecting the head and the chemical liquid storage tank to each other, and a controller configured to control collection and release of the nanorods of the classifier, wherein the classification chip includes a first electrode layer, an insulting layer, and a second electrode layer and collects and releases nanorods of a certain size among the plurality of nanorods, the plurality of discharge pipes discharge the nanorods of the certain size to the outside before the nanorods of the certain size released by the classification chip are returned to the chemical liquid storage tank, the power supply supplies an alternating current to the classification chip, and the controller controls the plurality of classifiers to collect the nanorods of the certain size while the head is spraying the chemical liquid and controls the plurality of classifiers to release the nanorods through the plurality of discharge pipes while the head is not spraying the chemical liquid.

DETAILED DESCRIPTION

The present embodiments may have various changes and various forms, and accordingly, some embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present embodiments to a specific disclosure.

FIGS.1A to1Bare schematic configuration diagrams of a chemical liquid supply apparatus according to an embodiment of the disclosure.FIG.2is a schematic plan view of a classification chip of the chemical liquid supply apparatus illustrated inFIG.1A.FIGS.3and4are schematic diagrams illustrating an operation process of a classifier of a chemical liquid supply apparatus according to an embodiment of the disclosure.

Referring toFIGS.1A to4, a chemical liquid supply apparatus10may include a chemical liquid storage tank100, a circulation pipe200, a classifier300, a discharge pipe400, a head500, and a controller600.

The chemical liquid storage tank100of the chemical liquid supply apparatus10may store a chemical liquid110including nanorods120. The chemical liquid storage tank100may include an upper surface100_U and a lower surface100_L. The chemical liquid110may include a plurality of nanorods120. The nanorods120included in the chemical liquid110may each have a shape with a high aspect ratio of diameter to height. The nanorods120are dipole materials and may be aligned by an electric field. That is, positions of the nanorods120may be moved by dielectrophoresis (DEP) or direction of the nanorods120may be aligned by the DEP.

Both ends of the circulation pipe200of the chemical liquid supply apparatus10may be connected to the chemical liquid storage tank100. That is, both ends of the circulation pipe200may be connected to the liquid chemical liquid storage tank100such that the chemical liquid110stored in the liquid chemical liquid storage tank100may be circulated. In other words, the chemical liquid110flowing from the chemical liquid storage tank100to the circulation pipe200may return to the chemical liquid storage tank100by passing through the circulation pipe200. In some embodiments, one end of the circulation pipe200may be connected to the lower surface100_L of the liquid chemical liquid storage tank, and the other end may be connected to the upper surface100_U of the chemical liquid storage tank100. In other words, the chemical liquid110may flow out of one end of the circulation pipe200connected to the lower surface100_L of the chemical liquid storage tank100and flow into the other end of the circulation pipe200connected to the upper surface100_U of the chemical liquid storage tank100. That is, both ends of the circulation pipe200may be connected to positions of different heights of the chemical liquid storage tank100.

The circulation pipe200may include a first branch pipe210, a second branch pipe220, a circulation pipe pump201, a first flow rate measurer202, and a second flow rate measurer203.

The circulation pipe200may branch into the first branch pipe210and the second branch pipe220from one pipe. Specifically, after the circulation pipe200branches into the first branch pipe210and the second branch pipe220from one pipe, the first branch pipe210and the second branch pipe220may combine with each other to form one pipe.

The circulation pipe pump201of the circulation pipe200may provide power to the circulation pipe200such that the chemical liquid110flows through the circulation pipe200. In some embodiments, the circulation pipe pump201may adjust the amount of liquids flowing through the circulation pipe200. In some embodiments, the circulation pipe pump201may include any one of a centrifugal pump, a side flow pump, a reciprocating pump, a magnetic levitation pump, and a rotary pump.

The first flow rate measurer202of the circulation pipe200may measure a flow rate of a liquid flowing into the first branch pipe210. The second flow rate measurer203of the circulation pipe200may measure a flow rate of a liquid flowing into the circulation pipe200. A flow rate of a liquid flowing through the second branch pipe220may be calculated by using a value measured by the first flow rate measurer202and a value measured by the second flow rate measurer203. In some embodiments, the flow rate of the liquid flowing through the second branch pipe220may be less than the flow rate of the liquid flowing through the first branch pipe210. In some embodiments, the second flow rate measurer203may be located at the circulation pipe200behind a combined position of the first branch pipe210and the second branch pipe220.

A control valve204of the circulation pipe200may adjust a flow rate of the chemical liquid110flowing into the second branch pipe220. The flow rate of the chemical liquid110flowing into the second branch pipe220may be less than a flow rate of the chemical liquid110flowing into the first branch pipe210. That is, the control valve204may control a flow rate of a chemical liquid flowing into the branch pipe at which the classifier300is located to be less than a flow rate of the chemical liquid flowing into the other branch pipe. Although an example in which the control valve204is at the second branch pipe220is illustrated inFIG.1A, the control valve204is not limited thereto and may be located at the first branch pipe210to adjust a flow rate of the chemical liquid110flowing into the first branch pipe210.

The plurality of nanorods120of the chemical liquid110may be deposited on the lower surface100_L of the chemical liquid storage tank by gravity. The circulation pipe200according to the disclosure discharges the chemical liquid110from the lower surface100_L) of the chemical liquid storage tank100, introduces the chemical liquid110into the upper surface100_U of the chemical liquid storage tank100, and accordingly, it is possible to prevent the nanorods120from being deposited on the lower surface100_L of the chemical liquid storage tank100.

The classifier300of the chemical liquid supply apparatus10may be located at the second branch pipe220. In other words, the classifier300may be located at the branch pipe with a less flow rate among the first branch pipe210and the second branch pipe220. The classifier300may include a classification chip310inFIG.3and a power supply320inFIG.3.

The classification chip310of the classifier300may collect and release nanorods122of a certain size from among the plurality of nanorods120. In some embodiments, the classification chip310may separate only the nanorods122of a certain size from among the plurality of nanorods120included in the chemical liquid110flowing through the second branch pipe220.

The classification chip310may include a first electrode layer311, an insulating layer312, and a second electrode layer313. The insulating layer312may be between the first electrode layer311and the second electrode layer313. That is, the first electrode layer311, the insulating layer312, and the second electrode layer313may be sequentially stacked. In some embodiments, the first electrode layer311and the second electrode layer313may receive power from the power supply320. An electric field may be formed between the first electrode layer311and the second electrode layer313.

The insulating layer312of the classification chip310may have a first hole H1. The second electrode layer313of the classification chip310may have a second hole H2. The second hole H2may communicate with the first hole H1. In other words, the second electrode layer313may have the second hole H2having the same size as the first hole H1. The first hole H1may extend to a lower surface of the insulting layer312by passing through an upper surface of the insulating layer312, and the second hole H2may extend to a lower surface of the second electrode layer313by passing through an upper surface of the second electrode layer313. That is, when the classification chip310is viewed from the top, the first electrode layer311may be exposed to the outside by the first hole H1and the second hole H2. AlthoughFIG.2illustrates as an example that the first hole H1and the second hole H2each have a circular shape, the first hole H1and the second hole H2are not limited thereto and may each have a polygonal shape, such as a quadrangular shape, a pentagonal shape, or a hexagonal shape.

In some embodiments, a thickness T_H1of the first hole H1may be about 5 μm to about 600 μm, and a thickness T_H2of the second hole H2may be about 5 μm to about 600 μm. That is, the sum of the thickness of the first hole T_H1and the thickness of the second hole T_H2may be about 10 μm to about 1200 μm.

In some embodiments, a width W_H1of the first hole H1may be about 10 μm to about 800 μm. A width W_H2of the second hole H2may be about 10 μm to about 800 μm. In some embodiments, the width W_H1of the first hole H1and the width W_H2of the second hole H2may be the same. That is, a sidewall forming the width W_H1of the first hole H1and a sidewall forming the width W_H2of the second hole H2may form a common surface.

In some embodiments, the insulating layer312may have a plurality of first holes H1, and the second electrode layer313may have a plurality of second holes H2. The plurality of second holes H2may respectively communicate with the plurality of first holes H1. In some embodiments, the plurality of first holes H1may be separated from each other by a first distance P_H1. The plurality of second holes H2may be separated from each other by a second distance P_H2. The first distance P_H1and the second distance P_H2may be about 10 μm to about 100 μm. In some embodiments, the first distance P_H1may be equal to the second distance P_H2.

An electric field may be formed by the first electrode layer311and the second electrode layer313of the classification chip310. The plurality of nanorods120included in the chemical liquid110flowing through the classifier300may receive a dielectrophoretic force by an electric field. The dielectrophoretic force may vary depending on frequencies of the electric field. That is, when conditions under which DEP is formed are the same, the nanorods122of a certain size may be separated. In other words, the nanorods122of a certain size may be collected and released by the electric field formed by the first electrode layer311and the second electrode layer313. Accordingly, the plurality of nanorods120may be classified into the nanorods122of a certain size and nanorods121of the other sizes. The nanorods122of a certain size separated by the DEP may be accommodated in the first hole H1and the second hole H2. That is, the nanorods122of a certain size classified by an electric field may be collected in the first hole H1and the second hole H2formed in the classification chip310.

The power supply320of the classifier300may supply power to the first electrode layer311and the second electrode layer313of the classification chip310. A current supplied by the power supply320to the first electrode layer311and the second electrode layer313may include an alternating current. In some embodiments, a frequency of the alternating current may be between about 1 MHz and about 1000 MHz. The frequency of the alternating current of the power supply320may vary depending on sizes of the nanorods to be collected and released. That is, sizes of the nanorods to be collected and released may be adjusted by adjusting the frequency of the power supply320.

The plurality of nanorods120included in the chemical liquid110may have sizes substantially different from each other. A high-quality display may be obtained only by spraying nanorods of a uniform size when arranging the nanorods on a substrate. The classifier300according to the disclosure may collect the nanorods122of a certain size among the plurality of nanorods120of different sizes, and accordingly, the chemical liquid110passing through the classifier300may only include nanorods of size within a tolerance range. In other words, the quality of a display formed of the chemical liquid110supplied by the chemical liquid supply apparatus10may be improved by collecting nanorods of a size outside an error range by using the classifier.

The discharge pipe400of the chemical liquid supply apparatus10may discharge the chemical liquid110to the outside of the circulation pipe200. That is, the chemical liquid supply apparatus10may discharge at least a part of the chemical liquid110to the outside of the circulation pipe200through the discharge pipe400. In some embodiments, the chemical liquid110flowing into the classifier300may be discharged to the outside of the circulation pipe200. In some embodiments, the nanorods122of a certain size collected by the classification chip310may be released through the discharge pipe400. That is, the discharge pipe400may discharge the nanorods122of a certain size released from the classification chip310to the outside. The chemical liquid110discharged from the discharge pipe400may be discharged to the outside to be discarded or may be sent to a separate storage tank.

The discharge pipe400may discharge the nanorods122of a certain size to the outside before the nanorods122of a certain size released by the classification chip310are returned to the chemical liquid storage tank100. In some embodiments, the discharge pipe400may be located at the second branch pipe220through which the chemical liquid110passing through the classification chip310flows. In some embodiments, the discharge pipe400may be connected to the classifier300. AlthoughFIGS.1A and1Billustrate that the discharge pipe400is connected to the second branch pipe220or the classifier300, the discharge pipe400is not limited thereto and may be connected to the circulation pipe200behind the second branch pipe220.

The nanorods122of a certain size collected by the classification chip310are released through the release pipe400, and accordingly, the classifier300may be continuously used without replacing the classification chip310. Therefore, the classifier300is connected to the discharge pipe400to periodically releases the collected nanorods122of a certain size, and accordingly, the classifier300may be used without replacement unlike a foreign matter filter.

The head500of the chemical liquid supply apparatus10may spray the chemical liquid110onto the substrate. That is, the chemical liquid110stored in the chemical liquid storage tank100may be sprayed onto the substrate through the head500. A supply pipe501and a return pipe502of the chemical liquid supply apparatus10may connect the chemical liquid storage tank100to the head500. Specifically, the supply pipe501may provide a passage for the chemical liquid110to move from the chemical liquid storage tank100to the head500, and the return pipe502may provide a passage through which the mechanical liquid110remaining in the head500moves to the chemical liquid storage tank100. A head pump503of the chemical liquid supply apparatus10may provide power to circulate the chemical liquid110between the chemical liquid storage tank100and the head500. In some embodiments, the head pump503may be located at the return pipe502. The head pump503may include at least one of a centrifugal pump, a side flow pump, a reciprocating pump, a magnetic levitation pump, and a rotary pump.

The controller600of the chemical liquid supply apparatus10may control collection and release of the nanorods120of the classifier300. That is, the controller600may control the classifier300to collect the nanorods122of a certain size or to release the nanorods122of a certain size. In some embodiments, while the chemical liquid110is supplied to the head500and is sprayed onto a substrate, the controller600may control the classifier300to collect the nanorods122of a certain size. While the chemical liquid110is not sprayed onto the substrate, the controller600may control the nanorods122of a certain size collected in the classifier300to be released. In other words, the controller600may control the classifier300to collect the nanorods122of a certain size while the chemical liquid supply apparatus10performs printing on the substrate. The controller600may control the chemical liquid supply apparatus10to release the collected nanorods122of a certain size when the substrate is not being printed. A substrate printing process is a process in which the head500sprays the chemical liquid110onto the substrate, and a substrate non-printing process is a process in which the head500does not spray the chemical liquid110onto the substrate.

Referring toFIGS.3and4,FIG.3illustrates a state of the classifier300when the controller600controls the classifier300to collect the nanorods122of a certain size, andFIG.4illustrates a state of the classifier300when the controller600controls the classifier300to release the nanorods122of a certain size collected in the classifier300.

While the chemical liquid supply apparatus10performs printing on a substrate, the controller600may control the classifier300not to discharge a chemical liquid to the discharge pipe400. In some embodiments, the controller600may block a passage connected to the discharge pipe400while printing of the substrate such that the chemical liquid110does not flow out of the circulation pipe200from the classifier300. In addition, during the printing of the substrate, the controller600may cause power to be supplied from the power supply320to the classification chip310to form an electric field, and accordingly, the nanorods122of a certain size may be collected in the first hole H1and the second hole H1. In other words, the controller600may cause the nanorods122of a certain size included in the chemical liquid110flowed into the classifier300to be collected during the printing of the substrate and may case the other nanorods121to flow out to the second branch pipe220.

The controller600may control the classifier300to discharge the chemical liquid to the discharge pipe400while the chemical liquid supply apparatus10does not perform printing on a substrate. In some embodiments, the controller600may open a passage connected to the discharge pipe400during non-printing of the substrate, such that the chemical liquid110flows from the classifier300to the outside of the circulation pipe200. In addition, the controller600may adjust the frequency of the power supply320during the non-printing of the substrate, such that the collected nanorods122of a certain size are released from the first hole H1and the second hole H2. In other words, the controller600may release the nanorods122of a certain size collected during printing of the substrate to the outside of the circulation pipe200through the discharge pipe400during the non-printing.

FIG.5is a schematic configuration diagram illustrating a classifier of a chemical liquid supply apparatus according to an embodiment of the disclosure.

Hereinafter, overlapping contents of a classifier inFIG.5and the classifier inFIG.3are omitted, and differences therebetween are described.

Referring toFIG.5, the chemical liquid supply apparatus10may include a classifier300′. The classifier300′ may include a classification chip310aand the power supply320. The classification chip310amay include the first electrode layer311, an insulating layer312a, and a second electrode layer313a. The insulating layer312amay have a first hole H1a, and the second electrode layer313amay have a second hole H2acommunicating with the first hole H1a.

A width of the first hole H1amay be reduced as the first hole H1aapproaches the first electrode layer311. That is, the first hole H1amay have a tapered shape in which the width is reduced as the first hole H1aapproaches the first electrode layer311. In other words, a sidewall forming the first hole H1amay be inclined to be reduced as the first hole H1aapproaches the first electrode layer311. In some embodiments, the first hole H1amay have a first width W1_H1aon a lower surface of the insulating layer312aand may have a second width W2_H1aon an upper surface of the insulating layer312a. The first width W1_H1amay be less than the second width W2_H1a.

A width of the second hole H2may be reduced as the second hole H2approaches the insulating layer312a. That is, the second hole H2amay have a tapered shape in which the width is reduced as the second hole H2aapproaches the insulating layer312a. In other words, a sidewall forming the second hole H2amay be inclined to be less as the second hole H2aapproaches the insulating layer312a. In some embodiments, the second hole H2amay have a third width W1_H2aon a lower surface of the second electrode layer313aand may have a fourth width W2_H2aon an upper surface of the second electrode layer313a. The third width W1_H2amay be less than the fourth width W2_H2a. In some embodiments, the third width W1_H2amay be equal to the second width W2_H1aof the first hole H1. That is, the first hole H1amay communicate with the second hole H2a, and an upper surface of the first hole H1amay have the same area as a lower surface of the second hole H2a.

The classification chip310aaccording to the disclosure may include the first hole H1aand the second hole H2a, each having a tapered shape. The first hole H1aand the second hole H2aeach have an upper surface having a larger area to easily collect the nanorods122(inFIG.3) of a certain size and each have a lower surface having a less area to prevent the collected nanorods122from being unintentionally released.

FIG.6is a schematic configuration diagram of a chemical liquid supply apparatus according to an embodiment of the disclosure.

Hereinafter, overlapping contents of a chemical liquid supply apparatus10ainFIG.6and the chemical liquid supply apparatus10inFIG.1Aare omitted and differences therebetween are described.

Referring toFIG.6, the chemical liquid supply apparatus10amay further include a degassing device205and a distribution measurer101.

The degassing device205of the chemical liquid supply apparatus10amay be located at the circulation pipe200. The degassing device205may remove air bubbles in the chemical liquid110. In some embodiments, air bubbles may be formed inside the chemical liquid110while a chemical liquid is distributed to the first branch pipe210and the second branch pipe220from the circulation pipe200and is combined from the first branch pipe210and the second branch pipe220to the circulation pipe200. The air bubbles in the chemical liquid110may degrade the quality of a display during printing of a substrate. The chemical liquid supply apparatus10aaccording to the disclosure may removes the air bubbles present in the chemical liquid110by using the degassing device205, and thus, the quality of the display may be improved.

The distribution measurer101of the chemical liquid supply apparatus10amay measure a degree of distribution of the plurality of nanorods120in the chemical liquid110. That is, the number of the plurality of nanorods120in the chemical liquid110may be measured. In other words, the number of the plurality of nanorods120per certain volume of the chemical liquid110may be measured. The distribution measurer101may be inside the chemical liquid storage tank100. When a certain amount of nanorods are sprayed onto a substrate, a display may emit uniform brightness in all areas. The chemical liquid supply apparatus10aaccording to the disclosure may measure the degree of distribution of the plurality of nanorods120in the chemical liquid by using the distribution measurer101and print a high-quality display.

Although the chemical liquid supply apparatus10aincluding the degassing device205and the distribution measurer101is illustrated inFIG.6, the chemical liquid supply device10ais not limited thereto and may include either the degassing device205or the distribution measurer101.

FIG.7is a schematic configuration diagram of a chemical liquid supply apparatus according to an embodiment of the disclosure.

Hereinafter, overlapping contents of a chemical liquid supply apparatus10binFIG.7and the chemical liquid supply apparatus10inFIG.1Aare omitted and differences therebetween are described.

Referring toFIG.7, the chemical liquid supply apparatus10bmay include a plurality of chemical liquid storage tanks. In some embodiments, the liquid chemical supply apparatus10bmay include a first chemical liquid storage tank100and a second chemical liquid storage tank100a. The first liquid chemical liquid storage tank100and the second chemical liquid storage tank100amay each store a chemical liquid110including a plurality of nanorods120. A circulation pipe200may be connected to the first chemical liquid storage tank100and the second chemical liquid storage tank100a. That is, the circulation pipe200may provide a passage through which the chemical liquid110flows out from a lower surface100_L of the first chemical liquid storage tank100and a lower surface100a_L of the second chemical liquid storage tank100aand flows into an upper surface100_U of the first chemical liquid storage tank100and an upper surface100a_U of the second chemical liquid storage tank100a. AlthoughFIG.7illustrates an example in which the first chemical liquid storage tank100is connected to a head500, the disclosure is not limited thereto, and the first chemical liquid storage tank100and the second chemical liquid storage tank100amay be connected to the head500.

FIGS.8to10are schematic configuration diagrams of chemical liquid supply apparatuses according to embodiments of the disclosure.

Hereinafter, overlapping contents of chemical liquid supply apparatuses10c,10d, and10erespectively illustrated inFIG.8,FIG.9, andFIG.10and the chemical liquid supply apparatus10inFIG.1Aare omitted and differences therebetween are described.

Referring toFIG.8, a circulation pipe200aof the chemical liquid supply apparatus10cmay include a main flow pipe210aand a plurality of branch pipes220a. In other words, the circulation pipe200amay have both ends connected to the chemical liquid storage tank100and may include the main flow pipe210aand the plurality of branch pipes220abranching into a plurality of branches between both ends of the circulation pipe200. Flow rate of chemical liquids that may be accommodated in the plurality of branch pipes220amay be less than a flow rate of a chemical liquid that may be accommodated in the main flow pipe210a.

The plurality of branch pipes220aof the chemical liquid supply apparatus10cmay respectively include control valves204. That is, chemical liquids flowing through the plurality of branch pipes220amay have different flow rates. The control valves204may respectively control flow rates of the chemical liquids to the most appropriate flow rates at which nanorods of a certain size may be classified in each of a plurality of classifiers300a.

The plurality of classifiers300aof the chemical liquid supply apparatus10cmay be respectively located at the plurality of branch pipes220a. In other words, the branch pipes and the classifiers may correspond one-to-one. The plurality of classifiers300amay respectively include classification chips and power supplies. The classification chips of the plurality of classifiers300arespectively installed in the plurality of branch pipes220amay collect and release nanorods of a certain size from the plurality of branch pipes. In some embodiments, the plurality of classifiers300amay include the classifier300illustrated inFIG.1Aor the classifier300′ illustrated inFIG.5.

In some embodiments, the plurality of classifiers300aof the chemical liquid supply apparatus10cmay be in parallel to a plurality of different branch pipes220a. In some embodiments, the plurality of classifiers300ain parallel to the plurality of different branch pipes220amay collect and release nanorods of the same size. That is, the plurality of classifiers300aconfigured to collect and release the nanorods of the same size may be respectively located at the plurality of branch pipes220athat are different from each other. In other words, the plurality of classifiers300athat may collect the nanorods of the same size may be installed in each of the plurality of branch pipes220a. Specifically, a first classifier300a1may be located at one of the plurality of branch pipes220a. A second classifier300a2may be located at a branch pipe different from the branch pipe. The first classifier300a1and the second classifier300a2may collect and release nanorods of the same size.

One classifier may classify nanorods of a certain size in a chemical liquid of a low flow rate. In the circulation pipe200aaccording to the disclosure, the plurality of classifiers300athat may collect nanorods of the same size may be located at each of the plurality of branch pipes220a. Accordingly, the chemical liquid supply apparatus10cmay classify nanorods of a certain size at a high flow rate. Accordingly, the chemical liquid supply apparatus10caccording to the disclosure may efficiently classify the nanorods of a certain size.

In some embodiments, a plurality of classifiers300bof the chemical liquid supply apparatus10dmay be located in series at one branch pipe among the plurality of branch pipes. In other words, in one branch pipe, a chemical liquid passing through one classifier may flow into another classifier. In some embodiments, the plurality of classifiers300blocated in series may collect and release nanorods of different sizes. In other words, a plurality of classifiers300bconfigured to collect and release nanorods of different sizes may be located at one branch pipe. In other words, the plurality of classifiers300bthat may collect nanorods of different sizes may be installed in one branch pipe among the plurality of branch pipes. Specifically, a third classifier300b1and a fourth classifier300b2may be located at one branch pipe. The third classifier300b1and the fourth classifier300b2may collect and release nanorods of different sizes.

The plurality of classifiers300bmay each collect and release nanorods of a certain set size. The classifiers may adjust sizes of the nanorods to be collected and released by controlling DEP, such as frequency. By installing a plurality of classifiers that may collect nanorods of different sizes at one branch pipe, nanorods of various sizes may be collected and released in one cycle. The chemical liquid supply apparatus10daccording to the disclosure may classify nanorods other than the nanorods mounted on a display among the plurality of nanorods at once through the plurality of classifiers300barranged in series. Therefore, it is possible to prevent nanorods outside an error range from being sprayed onto a substrate, and thus, a high-quality display may be obtained.

In some embodiments, a plurality of classifiers300cof the chemical liquid supply apparatus10einclude a first group300_R in which sizes of nanorods to be collected and released are the same as each other, and a second group300_C in which the sizes of the nanorods are different from each other. The first group300_R may be located at a plurality of different branch pipes, and the second group300_C may be located at one branch pipe. That is, a plurality of classifiers that collect nanorods of the same size may be located in parallel at a plurality of different branch pipes. The classifiers that collect nanorods of different sizes may be located in series at one branch pipe.

In some embodiments, the plurality of classifiers300cmay include first to third classifiers. The first classifier and the second classifier may collect nanorods of the same size, and the first classifier and the third classifier may collect nanorods of different sizes. That is, the first classifier and the second classifier may form the first group300_R, and the first classifier and the third classifier may form the second group300_C. The first classifier and the second classifier may be located at a plurality of different branch pipes, and the first classifier and the third classifier may be located at the same branch pipe.

One classifier may classify nanorods of a certain size at a low flow rate. In a circulation pipe200caccording to the disclosure, the first group300_R that may collect nanorods of the same size may be located at each of the plurality of branch pipes. Accordingly, the chemical liquid supply apparatus may classify nanorods of a certain size at a high flow rate. Accordingly, the chemical liquid supply apparatus10eaccording to the disclosure may efficiently classify nanorods of a certain size.

By installing the second group300_C that may collect nanorods of different sizes at one branch pipe, nanorods of various sizes may be collected and released at once. The chemical liquid supply apparatus10eaccording to the disclosure may classify nanorods other than the nanorods mounted on a display among the plurality of nanorods at once through a plurality of classifiers arranged in series. Therefore, it is possible to prevent nanorods outside an error range from being sprayed onto a substrate, and thus, a high-quality display may be obtained.

So far, the disclosure is described with reference to the embodiments illustrated in the drawings, but these are only examples, and those skilled in the art will understand that various modifications and equivalent other embodiments may be made therefrom. Therefore, the true technical protection scope of the disclosure should be determined by the technical idea of the appended claims.