Substrate processing liquid supply unit and substrate processing apparatus provided with same

Abstract

The present application provides a substrate processing liquid supply unit that maintains a nozzle liquid level of an inkjet head unit constant by real-time liquid level measurement, and a substrate processing apparatus provided with the same. The substrate processing liquid supply unit includes a first liquid reservoir connected to an inkjet head unit that ejects a substrate processing liquid onto a substrate, and supplies the substrate processing liquid to the inkjet head unit; a liquid level sensor that measures a liquid level of the substrate processing liquid stored in the first liquid reservoir; and a pressure control module that compensates for a pressure supplied to the first liquid reservoir based on a liquid level variation amount of the substrate processing liquid, and maintains the nozzle liquid level of the inkjet head unit constant.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate processing liquid supply unit and a substrate processing apparatus provided with the same. More specifically, it relates to a substrate processing liquid supply unit that supplies a substrate processing liquid to an inkjet head unit that ejects the substrate processing liquid onto a substrate and a substrate processing apparatus provided with the same. BACKGROUND

[0002] In the case where a printing process (e.g., RGB patterning) is performed on a transparent substrate in order to manufacture a display device such as an LCD panel, a PDP panel, an LED panel, or the like, a printing apparatus provided with an inkjet head unit can be used.

[0003] The inkjet head unit can be used to eject a chemical liquid onto a substrate. At this time, the chemical liquid must maintain a good meniscus at the nozzle end of the inkjet head unit, and if the chemical liquid fails to maintain the meniscus at the nozzle end, problems such as non-ejection or poor ejection can occur.

[0004] Therefore, it is necessary to maintain the nozzle meniscus of the inkjet head unit fixed at all times. However, it is difficult to cope with changes in the nozzle meniscus due to variations in the internal liquid level of a reservoir for supplying or printing the chemical liquid, which can adversely affect the ejection quality or the life of the inkjet head unit. SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] The present application relates to a substrate processing liquid supply unit and a substrate processing apparatus provided with the same. More specifically, it relates to a substrate processing liquid supply unit that supplies a substrate processing liquid to an inkjet head unit that ejects the substrate processing liquid onto a substrate and a substrate processing apparatus provided with the same.

[0007] The technical problems of the present application are not limited to the above-mentioned technical problems, and other technical problems that are not mentioned can be clearly understood by a person skilled in the art from the following description.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] One aspect of the substrate processing liquid supply unit of the present application for solving the above-mentioned technical problems includes: a first reservoir connected to an inkjet head unit that ejects a substrate processing liquid onto a substrate and supplying the substrate processing liquid to the inkjet head unit; a liquid level sensor that measures the liquid level of the substrate processing liquid stored in the first reservoir; and a pressure control module that compensates for the pressure supplied to the first reservoir based on the amount of variation in the liquid level of the substrate processing liquid and maintains the nozzle meniscus of the inkjet head unit fixed.

[0010] The liquid level sensor may measure the liquid level of the substrate processing liquid in real time, and the pressure control module may compensate the pressure provided to the first liquid reservoir in real time to maintain a fixed liquid level in the nozzle of the inkjet head unit.

[0011] The liquid level sensor may be capable of continuously measuring the liquid level of the substrate processing liquid.

[0012] The pressure control module may include: a control board that calculates the pressure supplied to the first reservoir based on a reference value and a measurement value of the liquid level sensor; and a pressure supply portion that compensates the pressure supplied to the first reservoir based on the calculated value.

[0013] The pressure control module may calculate the pressure supplied to the first liquid reservoir based on a reference value, a density of the substrate treating liquid, and a level variation of the substrate treating liquid.

[0014] The pressure control module may multiply the density of the substrate processing liquid, the gravitational acceleration, and the liquid level variation of the substrate processing liquid to calculate the pressure variation provided to the first liquid reservoir, and add the pressure variation to the reference value to calculate the pressure provided to the first liquid reservoir.

[0015] The reference value may be a preset value, which is a pressure value for a space in the internal space of the first tank that is not filled with the substrate processing liquid.

[0016] The pressure control module may be connected to the first liquid reservoir via an air pressure line.

[0017] The pressure control module may compensate for negative pressure as pressure provided to the first reservoir.

[0018] The substrate processing liquid supply unit may further include a second liquid reservoir connected to the first liquid reservoir and configured to replenish the first liquid reservoir with the substrate processing liquid.

[0019] The pressure control module may supplement the first liquid reservoir with a flow rate corresponding to the liquid level variation of the substrate processing liquid to compensate for the pressure provided to the first liquid reservoir.

[0020] The liquid level sensor may start measuring the liquid level of the substrate processing liquid after filling the first liquid reservoir with the substrate processing liquid to a predetermined water level and setting a pressure value for the space in the internal space of the first liquid reservoir that is not filled with the substrate processing liquid.

[0021] The liquid level sensor may measure a liquid level of the substrate processing liquid when the substrate processing liquid is supplied from the first liquid tank to the inkjet head unit or when the substrate processing liquid is replenished in the first liquid tank.

[0022] The pressure control module may control the nozzle surface of the inkjet head unit to not be wetted when the liquid level of the substrate treating liquid decreases, and control the nozzle surface to not be dried when the liquid level of the substrate treating liquid increases.

[0023] Another aspect of the substrate processing liquid supply unit of the present invention for solving the above-mentioned problems includes: a first liquid reservoir, which is connected to an inkjet head unit that sprays substrate processing liquid onto a substrate and supplies the substrate processing liquid to the inkjet head unit; a liquid level sensor that measures the liquid level of the substrate processing liquid stored in the first liquid reservoir in real time; and a pressure control module that calculates the pressure provided to the first liquid reservoir based on a reference value, the density of the substrate processing liquid, the acceleration of gravity, and the liquid level change of the substrate processing liquid, and compensates the pressure provided to the first liquid reservoir in real time based on the calculated value, and maintains the nozzle liquid level of the inkjet head unit fixed.

[0024] One aspect of the substrate processing device of the present invention for solving the above-mentioned problems includes: an inkjet head unit, which sprays substrate processing liquid onto a substrate; and a substrate processing liquid supply unit, which supplies the substrate processing liquid to the inkjet head unit, and the substrate processing liquid supply unit includes: a first liquid reservoir, which is connected to the inkjet head unit and supplies the substrate processing liquid to the inkjet head unit; a liquid level sensor, which measures the liquid level of the substrate processing liquid stored in the first liquid reservoir; and a pressure control module, which compensates for the pressure provided to the first liquid reservoir based on the liquid level change of the substrate processing liquid, and maintains the nozzle liquid level of the inkjet head unit fixed.

[0025] The substrate processing liquid may be QD (Quantum Dot) ink, and the substrate processing device may be a printing device.

[0026] The substrate processing apparatus may further include a maintenance unit configured to measure a spraying position of the substrate processing liquid on the substrate and whether the substrate processing liquid is sprayed.

[0027] Details of other embodiments are included in the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a diagram schematically showing the internal structure of a substrate processing apparatus according to one embodiment of the present invention;

[0029] Figure 2 is a first exemplary diagram schematically illustrating an internal structure of a substrate processing liquid supply unit constituting a substrate processing apparatus according to an embodiment of the present invention;

[0030] Figure 3 FIG. 2 is a second exemplary view schematically showing an internal structure of a substrate treatment liquid supply unit constituting a substrate treatment apparatus according to an embodiment of the present application;

[0031] Figure 4 FIG. 3 is a view schematically showing an external shape of a substrate treatment liquid supply unit constituting a substrate treatment apparatus according to an embodiment of the present application;

[0032] Figure 5 FIG. 4 is a flowchart for explaining a method of maintaining a nozzle liquid level of an inkjet head unit constituting a substrate treatment apparatus according to an embodiment of the present application constant.

[0033] Explanation of Reference Numerals

[0034] 100: substrate treatment apparatus 110: process treatment unit

[0035] 120: maintenance unit 130: rack unit

[0036] 140: inkjet head unit 150: substrate treatment liquid supply unit

[0037] 160: control unit 210: 1st liquid reservoir

[0038] 220: pressure control module 221: pressure supply portion

[0039] 222: control board 230: liquid level sensor

[0040] 240: air pressure line 250: treatment liquid supply line

[0041] 260: 2nd liquid reservoir 310: air pressure portion

[0042] 320: ink supply portion 330: pipe DETAILED DESCRIPTION

[0043] Embodiments of the present application will be explained in detail below with reference to the drawings. The same reference numerals are used on the same constituent elements on the drawings, and repeated description thereof is omitted.

[0044] The present application relates to a substrate treatment liquid supply unit that maintains a nozzle liquid level of an inkjet head unit constant by real-time liquid level measurement, and a substrate treatment apparatus provided with the same. Hereinafter, the present application will be explained in detail with reference to the drawings and the like.

[0045] Figure 1 FIG. 1 is a view showing an internal configuration of a substrate treatment apparatus according to an embodiment of the present application.

[0046] According to Figure 1The substrate processing apparatus 100 can be configured to include a process processing unit 110, a maintenance unit 120, a gantry unit 130, an inkjet head unit 140, a substrate processing liquid supply unit 150, and a controller 160.

[0047] The substrate processing apparatus 100 processes a substrate G (e.g., a glass substrate) for manufacturing a display device. Such a substrate processing apparatus 100 can be implemented as a printing device that jets a substrate processing liquid onto the substrate G by using the inkjet head unit 140, and can be implemented as a recirculating inkjet device in order to prevent the nozzles from being clogged by the substrate processing liquid.

[0048] The process processing unit 110 supports the substrate G during the PT operation performed on the substrate G. Such a process processing unit 110 can support the substrate G by a non-contact method. The process processing unit 110 can support the substrate G by, for example, floating the substrate G in the air by using air. However, the present embodiment is not limited thereto. The process processing unit 110 can also support the substrate G by a contact method. The process processing unit 110 can support the substrate G by, for example, using a support member having a seating surface provided on an upper portion.

[0049] On the other hand, the PT operation described above refers to a printing process performed on the substrate G by using a substrate processing liquid, and the substrate processing liquid refers to a chemical liquid used for the printing process performed on the substrate G. The substrate processing liquid can be, for example, a QD (Quantum Dot) ink containing ultra-fine semiconductor particles.

[0050] In a case where the substrate G is supported by air, the process processing unit 110 can be configured to include a first stage 111 and air holes 112. st Stage)111 and air holes 112.

[0051] The first stage 111 can be provided as a base on which the substrate G is seated on an upper portion thereof. The air holes 112 can be formed through an upper surface of such a first stage 111, and a plurality of air holes 112 can be formed within a PT zone on the first stage 111.

[0052] The air holes 112 can jet air toward an upper portion (third direction 30) of the first stage 111. The air holes 112 can float the substrate G seated on the first stage 111 in the air by the air.

[0053] On the other hand, although Figure 1Although not shown, the process unit 110 may further include a gripper. The gripper is used to prevent the substrate G from detaching from the first worktable 111 as it moves along the length direction (first direction 10) of the first worktable 111. The gripper can clamp the substrate G to prevent it from detaching from the first worktable 111, and when the substrate G moves, the gripper slides along a guide rail (not shown) while holding the substrate G.

[0054] The maintenance unit 120 measures the ejection position (i.e., dot) of the substrate processing liquid on the substrate G, whether the substrate processing liquid is ejected, etc. The maintenance unit 120 can measure the ejection position of the substrate processing liquid, whether the substrate processing liquid is ejected, etc. for each of the plurality of nozzles provided in the inkjet head unit 140, and provide the measurement results obtained in this manner to the control unit 160.

[0055] The maintenance unit 120 may include, for example, a second workbench (2 nd Stage)121、Third rail(3 rd GuideRail)122, First Board(1 st It is composed of a P1ate) 123, a calibration board (Calibration Board) 124 and a vision module (Vision Module) 125.

[0056] The second workbench 121 can be configured as a base similar to the first workbench 111 and arranged side by side with the first workbench 111. The second workbench 121 can be configured to have the same size as the first workbench 111, but can also be configured to have a smaller or larger size than the first workbench 111. The second workbench 121 can include an MT zone on its upper portion.

[0057] The third guide rail 122 guides the movement path of the first plate 123. Such a third guide rail 122 can be arranged on the second workbench 121 along the length direction (first direction 10) of the second workbench 121 to form at least one line. The third guide rail 122 can be implemented, for example, using an LM guide system (Linear Motor Guide System).

[0058] On the other hand, although Figure 1 Not shown, the maintenance unit 120 may further include a fourth guide rail (4 th The fourth guide rail can serve as a guide rail for guiding the movement path of the first plate 123, similar to the third guide rail 122. It is arranged on the second workbench 121 to form at least one line along the width direction (second direction 20) of the second workbench 121. Like the third guide rail 122, the fourth guide rail can also be implemented using an LM guide system.

[0059] The first plate 123 moves along the third guide rail 122 and / or the fourth guide rail on the second workbench 121. The first plate 123 can move along the third guide rail 122 alongside the substrate G, and can approach or move away from the substrate G along the fourth guide rail.

[0060] The calibration plate 124 is used to measure the ejection position of the substrate processing liquid on the substrate (G). Such a calibration plate 124 may include alignment marks, a scale, etc. and is provided on the first plate 123 and may be arranged along the length direction (first direction 10) of the first plate 123.

[0061] The vision module 125 acquires image information of the substrate G to measure the ejection position of the substrate processing liquid, whether the substrate processing liquid is ejected, etc. The vision module 125 may include an area scan camera, a line scan camera, etc., and can acquire image information of the substrate G in real time. Furthermore, the vision module 125 can obtain and provide information about the substrate G ejected with the substrate processing liquid and information about the calibration plate 124.

[0062] The vision module 125 can be arranged on the side or underside of the stage unit 130 to image the substrate G, etc. The vision module 125 can be arranged, for example, in a form attached to the side of the inkjet head unit 140. However, this embodiment is not limited to this. The vision module 125 can also be arranged on the first plate 123. On the other hand, multiple vision modules 125 can be arranged in the substrate processing apparatus 100, and can be fixed or movable.

[0063] The stage unit 130 supports the inkjet head unit 140. The stage unit 130 may be disposed above the first work table 111 and the second work table 121 so that the inkjet head unit 140 can eject the substrate processing liquid onto the substrate G.

[0064] The stage unit 130 can be arranged on the first workbench 111 and the second workbench 121 with the width direction (second direction 20) of the first workbench 111 and the second workbench 121 as the length direction. st Guide Rail) 170a and the second guide rail (2 ndThe first guide rail 170a and the second guide rail 170b can be moved in the longitudinal direction (first direction 10) of the first workbench 111 and the second workbench 121. On the other hand, the first guide rail 170a and the second guide rail 170b can be arranged outside the first workbench 111 and the second workbench 121 along the longitudinal direction (first direction 10) of the first workbench 111 and the second workbench 121.

[0065] On the other hand, although Figure 1 Although not shown in the figure, the substrate processing apparatus 100 may further include a stage moving unit. The stage moving unit moves the stage unit 130 along the first guide rail 170a and the second guide rail 170b. The stage moving unit may be disposed inside the stage unit 130 and may include a first moving module (not shown) and a second moving module (not shown). The first moving module and the second moving module may be provided at both ends of the stage unit 130 and may enable the stage unit 130 to slide along the first guide rail 170a and the second guide rail 170b.

[0066] The inkjet head unit 140 ejects the substrate processing liquid in the form of droplets onto the substrate G. The inkjet head unit 140 may be disposed on the side or below the stage unit 130 .

[0067] At least one inkjet head unit 140 may be provided at the stage unit 130. When a plurality of inkjet head units 140 are provided at the stage unit 130, the plurality of inkjet head units 140 may be arranged in a row along the longitudinal direction (second direction 20) of the stage unit 130.

[0068] The inkjet head unit 140 can move along the length direction (second direction 20) of the stage unit 130 to be positioned at a desired location on the substrate G. However, the present embodiment is not limited thereto. The inkjet head unit 140 can move along the height direction (third direction 30) of the stage unit 130 and can also rotate clockwise or counterclockwise.

[0069] On the other hand, the inkjet head unit 140 can also be provided to be fixed to the stage unit 130. In this case, the stage unit 130 can be provided to be movably provided.

[0070] On the other hand, although Figure 1The substrate processing apparatus 100 can further include an inkjet head moving unit, which is not shown. The inkjet head moving unit linearly moves or rotates the inkjet head unit 140. In a case where the substrate processing apparatus 100 is configured to include a plurality of inkjet head units 140, the inkjet head moving unit can be provided in the substrate processing apparatus 100 in correspondence with the number of inkjet head units 140 so as to independently actuate the plurality of inkjet head units 140. On the other hand, a single inkjet head moving unit can be provided in the substrate processing apparatus 100 to uniformly actuate the plurality of inkjet head units 140.

[0071] On the other hand, although Figure 1 The inkjet head unit 140 can be configured to include a nozzle plate, a plurality of nozzles, a piezoelectric element, and the like, which are not shown. The nozzle plate constitutes a main body of the inkjet head unit 140. A plurality of (for example, 128, 256, and the like) nozzles can be provided as a plurality of rows and a plurality of columns at a lower portion of the nozzle plate at a certain interval, and the piezoelectric element can be disposed in the nozzle plate in a number corresponding to the number of nozzles. In a case where the inkjet head unit 140 is thus configured, the substrate processing liquid can be sprayed onto the substrate G through the nozzles according to the actuation of the piezoelectric element.

[0072] On the other hand, the inkjet head unit 140 can also independently adjust the amount of the substrate processing liquid sprayed through each nozzle according to the voltage applied to the piezoelectric element.

[0073] The substrate processing liquid supply unit 150 supplies ink to the inkjet head unit 140. Such a substrate processing liquid supply unit 150 can be configured to include a first reservoir (1 st Reservoir) 210 and a pressure control module 220.

[0074] The first reservoir 210 stores the substrate processing liquid, and the pressure control module 220 adjusts the internal pressure of the first reservoir 210. The first reservoir 210 can supply the inkjet head unit 140 with an appropriate amount of the substrate processing liquid based on the pressure supplied by the pressure control module 220.

[0075] The control unit 160 performs maintenance with respect to the inkjet head unit 140. Such a control unit 160 can correct the substrate processing liquid spray position of each nozzle possessed by the inkjet head unit 140 or detect a defective nozzle (i.e., a nozzle that does not spray the substrate processing liquid) among the plurality of nozzles based on the measurement result of the maintenance unit 120, so that a cleaning operation is performed on the defective nozzle. To this end, the control unit 160 can thereby control the actuation of each structure constituting the substrate processing apparatus 100.

[0076] The control unit 160 may include a process controller, a control program, an input module, an output module (or a display module), a storage module, and the like, and may be implemented by a computer or server. As described above, the process controller may include a microprocessor that controls the various components of the substrate processing apparatus 100, and the control program may execute various processes of the substrate processing apparatus 100 under the control of the process controller. The storage module stores programs, i.e., processing recipes, for executing various processes of the substrate processing apparatus 100 based on various data and processing conditions.

[0077] On the other hand, although Figure 1 Although not shown, the substrate processing apparatus 100 may further include a nozzle inspection unit. The nozzle inspection unit is used to determine whether there is an abnormality in each nozzle provided in the inkjet head unit 140. The nozzle inspection unit may determine whether there is an abnormality in the nozzle by, for example, optical inspection.

[0078] The substrate processing liquid supply unit 150 can supply the substrate processing liquid stored in the first liquid reservoir 210 to the inkjet head unit 140 based on the pressure provided by the pressure control module 220. At this time, if the pressure control module 220 provides a positive pressure, the liquid can be supplied from the first liquid reservoir 210 to the inkjet head unit 140, and if the pressure control module 220 provides a negative pressure, the supply of the liquid from the first liquid reservoir 210 to the inkjet head unit 140 can be stopped.

[0079] In this manner, the substrate treating liquid supply unit 150 may maintain a constant liquid level in the nozzles of the inkjet head unit 140 based on the pressure provided by the pressure control module 220 .

[0080] However, when printing on a large area, the substrate treatment liquid consumes a large amount of liquid. Therefore, even under the same negative pressure, the liquid level in the first liquid reservoir 210 may gradually decrease. Consequently, the liquid level in the nozzles of the inkjet head unit 140 may also fluctuate. This makes it difficult to cope with the changes in the liquid level in the nozzles of the inkjet head unit 140 that occur with the changes in the liquid level in the first liquid reservoir 210. Consequently, the ejection quality of the inkjet head unit 140 may be reduced, and the life of the inkjet head unit 140 may be shortened.

[0081] In addition, if the substrate processing liquid is constantly supplied to the inkjet head unit 140 in order to maintain the liquid level in the first liquid tank 210 within a certain range, the production time (Tact Time) may be affected by the repeated supply times.

[0082] In this embodiment, in order to maintain a constant liquid level in the nozzles of the inkjet head unit 140, the liquid level inside the first liquid reservoir 210 may be measured in real time. This will be described in detail below.

[0083] Figure 2 is a first exemplary view schematically illustrating an internal structure of a substrate treatment liquid supply unit constituting a substrate treatment apparatus according to an embodiment of the present application.

[0084] Referring to Figure 2 , the substrate treatment liquid supply unit 150 can be constituted including a first reservoir 210, a pressure control module 220, and a liquid level sensor 230.

[0085] The first reservoir 210 supplies the substrate treatment liquid to the inkjet head unit 140. Such a first reservoir 210 can be provided at an upper portion of the inkjet head unit 140, and can be connected to the inkjet head unit 140 through a pipe having a predetermined length.

[0086] The liquid level sensor 230 measures a liquid level of the substrate treatment liquid stored inside the first reservoir 210. Such a liquid level sensor 230 can measure the liquid level of the substrate treatment liquid in real time.

[0087] The liquid level sensor 230 can be constituted in a type capable of continuous measurement in order to measure the liquid level of the substrate treatment liquid in real time. Although a measurement method of the liquid level sensor 230 is not limited to a specific method, in the present embodiment, in order to compensate for the liquid level of the substrate treatment liquid stored inside the first reservoir 210 in real time, it is sufficient to be constituted in a type capable of continuous measurement. The liquid level sensor 230 can be implemented, for example, by a continuous type liquid level sensor of an electrostatic capacitance type.

[0088] The pressure control module 220 controls a pressure supplied to an inside of the first reservoir 210 in which the substrate treatment liquid is stored, based on a measurement value of the liquid level sensor 230. To this end, the pressure control module 220 can include a pressure supply part 221 and a control board 222.

[0089] The control board 222 calculates the pressure supplied to the first reservoir 210. Such a control board 222 can calculate the pressure supplied to the first reservoir 210 based on a measurement value of the liquid level sensor 230 and a reference value. The control board 222 can be implemented in a board type including a microprocessor having an arithmetic function, a memory having a storage function, etc. In a case where the pressure control module 220 is implemented as a PCM (Pressure Controller Module), the control board 222 can be implemented as a PCON (Pressure Controller) in a board type.

[0090] The control board 222 can calculate the pressure supplied to the first reservoir 210 using the following equation.

[0091] P=Reference Value+Variation Value=Reference Value+ρgh

[0092] In the above description, P represents the pressure supplied to the first liquid reservoir 210, and Reference Value represents a reference value. The reference value may be a predetermined set pressure value of the pressure supply unit 221. Furthermore, Variation Value represents the variation in the pressure supplied to the first liquid reservoir 210, and ρ represents the density of the substrate processing liquid stored within the first liquid reservoir 210. Furthermore, g represents the acceleration due to gravity, and h represents the variation in the liquid level of the substrate processing liquid stored within the first liquid reservoir 210.

[0093] In the above description, the liquid level of the substrate processing liquid stored in the first liquid reservoir 210 can be obtained by measuring the position information of the liquid surface in the first liquid reservoir 210 in real time using the liquid level sensor 230 .

[0094] However, the present embodiment is not limited thereto. The liquid level of the substrate processing liquid may be provided as a ratio between the substrate processing liquid region and the air region within the first reservoir 210 .

[0095] On the other hand, the control board 222 can receive the measurement value of the liquid level sensor 230 and the set value (i.e., the reference value) of the pressure providing unit 221 in real time, and feed back the corresponding pressure compensation value (i.e., the pressure calculated by the above equation) to the pressure providing unit 221.

[0096] The pressure providing unit 221 provides pressure to the interior of the first tank 210 based on the pressure compensation value calculated by the control board 222. The pressure providing unit 221 can provide negative pressure to the interior of the first tank 210 while maintaining the nozzle liquid level of the inkjet head unit 140 constant.

[0097] The pressure providing unit 221 may use air to provide a given amount of pressure to the interior of the first liquid reservoir 210. To this end, the pressure providing unit 221 and the first liquid reservoir 210 may be connected to an air pressure line 240 that manages the pressure of the air layer.

[0098] On the other hand, the substrate treating liquid supply unit 150 can further include a second liquid tank 260 in addition to the first liquid tank 210 .

[0099] Figure 3 FIG. 1 is a second exemplary diagram schematically showing the internal structure of a substrate processing liquid supply unit constituting a substrate processing apparatus according to an embodiment of the present invention.

[0100] Reference Figure 3The substrate processing liquid supply unit 150 can be configured including the first reservoir 210, the pressure control module 220, the liquid level sensor 230, and a second reservoir.

[0101] The first reservoir 210, the pressure control module 220, and the liquid level sensor 230 have been described above with reference to Figure 2 and a detailed description thereof will be omitted here.

[0102] The second reservoir 260 receives supply of the substrate processing liquid from an external supply source (not shown) and stores it. Such a second reservoir 260 can be disposed at an upper portion of the first reservoir 210 and can function to replenish the substrate processing liquid stored in the first reservoir 210.

[0103] In a case where the substrate processing liquid supply unit 150 includes the first reservoir 210 and the second reservoir 260, the first reservoir 210 can be implemented by a supply reservoir module (SRM) and the second reservoir 260 can be implemented by a buffer reservoir module (BRM).

[0104] On the other hand, in a case where the substrate processing liquid supply unit 150 includes only the first reservoir 210, the first reservoir 210 can be implemented in a form in which a supply reservoir module (SRM) and a buffer reservoir module (BRM) are combined. That is, the first reservoir 210 can receive supply of the substrate processing liquid from an external supply source and store it, and can supply the substrate processing liquid to the inkjet head unit 140 at the time of printing operation.

[0105] On the other hand, the control board 222 can also control the second reservoir 260 or the external supply source so that the first reservoir 210 is supplied with a flow rate corresponding to the pressure compensation value. For example, in a case where the pressure supply part 221 cannot normally operate due to a failure or the like (for example, in a case where the pressure supply part 221 cannot supply negative pressure to the first reservoir 210), the control board 222 controls the second reservoir 260 or the external supply source so that the first reservoir 210 is supplied with a flow rate corresponding to the pressure compensation value.

[0106] On the other hand, in a case where the substrate processing liquid supply unit 150 is configured including the first reservoir 210 and the liquid level sensor 230, it can be implemented in the form shown in FIG. 2B. Figure 4 Figure 4 FIG. 1 is a diagram schematically showing an external shape of a substrate processing liquid supply unit constituting a substrate processing apparatus according to one embodiment of the present application. The following description refers to FIG. 1. Figure 4

[0107] ​​The liquid level sensor 230 may be provided on the outer side of the first liquid reservoir 210. Such a liquid level sensor 230 may be provided on the outer side of the first liquid reservoir 210 with the height direction (third direction) 30 of the first water reservoir 210 as the longitudinal direction.

[0108] If the liquid level sensor 230 is disposed on the side of the first liquid reservoir 210, it can detect the liquid level fluctuation of the substrate processing liquid in real time, and the pressure control module 220 can compensate for the pressure (negative pressure) corresponding to the liquid level fluctuation of the substrate processing liquid in real time. Therefore, in this embodiment, various problems that may arise when the liquid level rises or falls can be solved.

[0109] An air pressure unit 310 connected to the air pressure line 240 may be provided above the first liquid reservoir 210, and an ink supply unit 320 connected to the processing liquid supply line 250 may be provided together with the air pressure unit 310. When the substrate processing liquid supply unit 150 includes the first liquid reservoir 210 and the second liquid reservoir 260, the processing liquid supply line 250 may connect the first liquid reservoir 210 and the second liquid reservoir 260. When the substrate processing liquid supply unit 150 includes only the first liquid reservoir 210, the processing liquid supply line 250 may connect the first liquid reservoir 210 to an external supply source.

[0110] On the other hand, a pipe 330 connecting the first tank 210 and the inkjet head unit 140 may be provided at a lower portion of the first tank 210 .

[0111] Reference above Figures 2 to 4 The substrate processing liquid supply unit 150 is described as measuring the liquid level of the substrate processing liquid in real time and providing a corresponding pressure. Next, a method of measuring the liquid level of the substrate processing liquid in real time to maintain a constant liquid surface of the nozzle of the inkjet head unit 140 is described.

[0112] Figure 5 This is a flowchart for explaining a method for maintaining a fixed liquid level in a nozzle of an inkjet head unit constituting a substrate processing apparatus according to an embodiment of the present invention. Figure 5 .

[0113] First, the second liquid reservoir 260 fills the first liquid reservoir 210 with the substrate processing liquid to a predetermined level (S410). At this time, an external supply source can also fill the first liquid reservoir 210 with the substrate processing liquid to a predetermined level.

[0114] Then, the control board 222 and the pressure providing part 221 set the remaining space (i.e., the air layer) in the internal space of the first liquid reservoir 210 (i.e., the storage space for storing the substrate processing liquid) except the space filled with the substrate processing liquid (i.e., the chemical liquid space) to a preset negative pressure value (S420).

[0115] Then, the liquid level sensor 230 measures the liquid level change of the substrate processing liquid in the first liquid reservoir 210 (S430). The liquid level sensor 230 can measure the liquid level change of the substrate processing liquid in real time. The liquid level change can also be measured when the substrate processing liquid is supplied from the first liquid reservoir 210 to the inkjet head unit 140, thereby consuming the substrate processing liquid stored in the first liquid reservoir 210, or when the substrate processing liquid is supplied from the second liquid reservoir 260 or an external supply source to the first liquid reservoir 210, thereby filling the first liquid reservoir 210 with the substrate processing liquid.

[0116] Then, the control board 222 compares the liquid level change measured by the liquid level sensor 230 with the preset liquid level value, and calculates the difference in pressure change corresponding to its difference value (i.e., the difference between the liquid level change and the preset liquid level value) using the equation described above (S440).

[0117] Then, the control board 222 feeds back the amount of change compared to the preset negative pressure to the pressure providing part 221 based on the arithmetic value (S450).

[0118] Then, the pressure providing unit 221 checks the negative pressure variation fed back from the control board 222 and performs feedback control on the actual negative pressure to the first reservoir 210 (S460). The feedback control of the pressure providing unit 221 can be continuously provided together with the real-time measurement of the liquid level sensor 230.

[0119] On the other hand, after the feedback control (S460) of the pressure providing part 221, if the liquid level area of ​​the substrate processing liquid in the first liquid reservoir 210 is higher than the preset liquid level area, the substrate processing liquid can be discharged to the outside; if the liquid level area of ​​the substrate processing liquid in the first liquid reservoir 210 is lower than the preset liquid level area, the substrate processing liquid can be replenished to the first liquid reservoir 210.

[0120] Refer to above Figures 1 to 5 The substrate treating liquid supply unit 150 and the substrate treating apparatus 100 including the same according to one embodiment of the present invention are described.

[0121] The present invention relates to an apparatus and method for maintaining a constant liquid level in the nozzles of an inkjet head unit 140 through real-time liquid level measurement by a liquid level sensor 230. Specifically, the present invention can detect changes in the liquid level within a liquid supply device (i.e., a first liquid reservoir 210) in real time and compensate for the negative pressure corresponding to the change in real time, thereby maintaining a constant liquid level in the nozzles of the inkjet head unit 140.

[0122] The present invention can provide a liquid level measuring device including a storage place (i.e., a first liquid reservoir 210) capable of supplying medicinal liquid, a liquid level sensor 230 for measuring the liquid level in the storage space of the storage place, a pressure control device for adjusting the pressure (i.e., a pressure providing part 221), and a control panel 222.

[0123] In addition, the present invention receives measured liquid level information from the liquid level sensor 230 for setting a negative pressure and liquid level with a reference value, compares the actual liquid level value with the preset liquid level value, and performs feedback control on the difference between the preset negative pressure value and the actual negative pressure value, thereby maintaining the nozzle liquid level of the inkjet head unit 140 fixed.

[0124] According to the present invention, wetting / drying of the nozzle surface can be prevented by compensating for negative pressure corresponding to changes in the substrate processing liquid level. Specifically, when the liquid level decreases, wetting of the nozzle surface can be prevented, thereby maintaining the ejection quality of the inkjet head unit 140. Furthermore, when the liquid level increases, drying of the nozzle surface can be prevented, thereby extending the life of the inkjet head unit 140.

[0125] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, but can be manufactured in various forms. Moreover, those skilled in the art will recognize that the present invention can be implemented in other specific forms without changing the technical concept or basic features of the present invention. Therefore, it should be understood that the above embodiments are illustrative in all aspects and not restrictive.

Claims

1. A substrate processing liquid supply unit, comprising: a first liquid reservoir connected to an inkjet head unit that ejects a substrate processing liquid onto a substrate and supplies the substrate processing liquid to the inkjet head unit; a liquid level sensor for measuring a liquid level of the substrate processing liquid stored in the first liquid reservoir; a pressure control module that compensates the pressure provided to the first liquid reservoir based on a level variation of the substrate processing liquid; as well as a second liquid reservoir connected to the first liquid reservoir and replenishing the substrate processing liquid to the first liquid reservoir; The substrate processing liquid supply unit maintains the liquid level of the nozzle of the inkjet head unit constant. The pressure control module includes: a control board that calculates the pressure provided to the first reservoir based on a reference value and a measurement value of the liquid level sensor; and a pressure supply portion that compensates the pressure supplied to the first reservoir based on the calculated value, The control board controls the second liquid reservoir so as to provide a flow rate corresponding to the pressure compensation value to the first liquid reservoir when the pressure providing unit cannot provide negative pressure to the first liquid reservoir.

2. The substrate processing liquid supply unit according to claim 1, wherein: The liquid level sensor measures the liquid level of the substrate processing liquid in real time. The pressure control module compensates the pressure supplied to the first liquid reservoir in real time to maintain a constant liquid level in the nozzles of the inkjet head unit.

3. The substrate processing liquid supply unit according to claim 1, wherein: The liquid level sensor is capable of continuously measuring the liquid level of the substrate processing liquid.

4. The substrate processing liquid supply unit according to claim 1, wherein: The pressure control module calculates a pressure supplied to the first liquid reservoir based on a reference value, a density of the substrate processing liquid, and a level change of the substrate processing liquid.

5. The substrate processing liquid supply unit according to claim 4, wherein: The pressure control module multiplies the density of the substrate processing liquid, the gravitational acceleration, and the liquid level variation of the substrate processing liquid to calculate the pressure variation provided to the first liquid reservoir, and adds the pressure variation to the reference value to calculate the pressure provided to the first liquid reservoir.

6. The substrate processing liquid supply unit according to claim 4, wherein: The reference value is a preset value and is a pressure value of a space in the internal space of the first liquid tank that is not filled with the substrate processing liquid.

7. The substrate processing liquid supply unit according to claim 1, wherein: The pressure control module is connected to the first liquid reservoir through an air pressure line.

8. The substrate processing liquid supply unit according to claim 1, wherein: The pressure control module compensates for negative pressure as pressure provided to the first reservoir.

9. The substrate processing liquid supply unit according to claim 1, wherein: The pressure control module replenishes the first liquid reservoir with a flow rate corresponding to a level change of the substrate processing liquid to compensate for the pressure provided to the first liquid reservoir.

10. The substrate processing liquid supply unit according to claim 1, wherein: The liquid level sensor starts measuring the liquid level of the substrate processing liquid after filling the first liquid reservoir with the substrate processing liquid to a predetermined liquid level and setting a pressure value for a space in the interior of the first liquid reservoir that is not filled with the substrate processing liquid.

11. The substrate processing liquid supply unit according to claim 1, wherein: The liquid level sensor measures a liquid level of the substrate processing liquid when the substrate processing liquid is supplied from the first liquid tank to the inkjet head unit or when the substrate processing liquid is replenished in the first liquid tank.

12. The substrate processing liquid supply unit according to claim 1, wherein: The pressure control module controls the nozzle surface of the inkjet head unit to not be wetted when the liquid level of the substrate treating liquid decreases, and controls the nozzle surface to not be dried when the liquid level of the substrate treating liquid increases.

13. A substrate processing liquid supply unit, comprising: a first liquid reservoir connected to an inkjet head unit that ejects a substrate processing liquid onto a substrate and supplies the substrate processing liquid to the inkjet head unit; a liquid level sensor for measuring the liquid level of the substrate processing liquid stored in the first liquid reservoir in real time; a pressure control module that calculates the pressure provided to the first liquid reservoir based on a reference value, the density of the substrate processing liquid, the acceleration of gravity, and the liquid level change of the substrate processing liquid, and compensates the pressure provided to the first liquid reservoir in real time based on the calculated value; as well as a second liquid reservoir connected to the first liquid reservoir and replenishing the substrate processing liquid to the first liquid reservoir; The substrate processing liquid supply unit maintains the liquid level of the nozzle of the inkjet head unit constant. The pressure control module includes: a control board that calculates the pressure provided to the first reservoir based on a reference value and a measurement value of the liquid level sensor; and a pressure supply portion that compensates the pressure supplied to the first reservoir based on the calculated value, The control board controls the second liquid reservoir so as to provide a flow rate corresponding to the pressure compensation value to the first liquid reservoir when the pressure providing unit cannot provide negative pressure to the first liquid reservoir.

14. A substrate processing apparatus, comprising: an inkjet head unit that ejects a substrate processing liquid onto a substrate; as well as a substrate processing liquid supply unit that supplies the substrate processing liquid to the inkjet head unit, The substrate processing liquid supply unit includes: a first liquid reservoir connected to the inkjet head unit and supplying the substrate processing liquid to the inkjet head unit; a liquid level sensor for measuring a liquid level of the substrate processing liquid stored in the first liquid reservoir; a pressure control module that compensates the pressure provided to the first liquid reservoir based on a level variation of the substrate processing liquid; and a second liquid reservoir connected to the first liquid reservoir and replenishing the substrate processing liquid to the first liquid reservoir; The substrate processing liquid supply unit maintains the liquid level of the nozzle of the inkjet head unit constant. The pressure control module includes: a control board that calculates the pressure supplied to the first reservoir based on a reference value and a measurement value of the liquid level sensor; and a pressure supply unit that compensates the pressure supplied to the first reservoir based on the calculated value. The control board controls the second liquid reservoir so as to provide a flow rate corresponding to the pressure compensation value to the first liquid reservoir when the pressure providing unit cannot provide negative pressure to the first liquid reservoir.

15. The substrate processing apparatus according to claim 14, wherein: The substrate treatment liquid is quantum dot ink, The substrate processing device is a printing device.

16. The substrate processing apparatus according to claim 14, wherein: The substrate processing apparatus further includes a maintenance unit configured to measure a spraying position of the substrate processing liquid on the substrate and whether the substrate processing liquid is sprayed.

17. The substrate processing apparatus according to claim 14, wherein: The liquid level sensor measures the liquid level of the substrate processing liquid in real time. The pressure control module compensates the pressure supplied to the first liquid reservoir in real time to maintain a constant liquid level in the nozzles of the inkjet head unit.

18. The substrate processing apparatus according to claim 14, wherein: The pressure control module calculates a pressure supplied to the first liquid reservoir based on a reference value, gravitational acceleration, a density of the substrate processing liquid, and a level change of the substrate processing liquid.

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