Liquid discharge device, substrate processing device, and article manufacturing method

Abstract

To provide a liquid discharge device which is advantageous for preventing foreign objects from remaining near a discharge port to keep quality of liquid application.SOLUTION: A liquid discharge device includes: a first discharge head which discharges a first liquid from a first discharge port; a second discharge head which discharges a second liquid from a second discharge port; a pressure control unit which individually controls pressures within the first discharge head and the second discharge head; and a suction unit which suctions the first discharge port and the second discharge port. The pressure control unit performs control so that the pressure within the first discharge head before the first discharge port is suctioned by the suction unit and the pressure within the second discharge head before the second discharge port is suctioned by the suction unit become pressure values different according to a difference in volatility between the first liquid and the second liquid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus, a substrate processing apparatus, and a method for manufacturing an article. [Background technology]

[0002] In recent years, attempts have been made to manufacture various functional elements by applying functional element materials using a liquid ejection device to form patterns (patterning). Patterning using a liquid ejection device has the advantages of high material usage efficiency because it allows on-demand patterning, the manufacturing equipment is relatively small because it is a non-vacuum process, and large areas can be coated at high speed.

[0003] In the liquid ejection device as described above, problems may occur such as foreign matter adhering to the vicinity of the liquid ejection port during dot pattern formation or standby, or the liquid flowing through the ejection port becoming viscous, resulting in ejection failure or quality degradation. As a means for solving such problems, Patent Document 1 describes a technology for pressurizing and discharging foreign matter and liquid inside the ejection port, and for suctioning and removing the deposits remaining on the surface of the ejection port without contact. With the ejection head changed to a positive pressure direction rather than the pressure during ejection, the deposits are sucked and removed using a suction port provided at a position facing the surface of the ejection port. This makes it possible to remove the deposits on the surface of the ejection port while preventing the deposits remaining on the surface of the ejection port from entering the ejection port.

[0004] As another technique for solving the problem of removing deposits on the surface of the discharge port, Patent Document 2 describes a technique using a jet nozzle and a suction nozzle provided at a position facing the surface of the discharge port. The jet nozzle is used to collect minute deposits on the surface of the discharge port, and the collected deposits are sucked and removed using the suction nozzle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-215638 A [Patent Document 2] JP 2012-045936 A Summary of the Invention [Problem to be solved by the invention]

[0006] Consider a liquid ejection device configured to eject different liquids from multiple ejection ports. In general, different liquids have different volatility. The more volatile the liquid contained in the ejection head, the faster any deposits remaining on the surface of the ejection port dry, and the problem arises that the deposits cannot be removed by suction without contact. Any foreign matter that dries and remains near the ejection port can cause ejection defects.

[0007] The present invention provides a liquid ejection device that is advantageous for preventing foreign matter from remaining near the ejection port and maintaining the quality of liquid application, for example. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided a liquid ejection device comprising a first ejection head which ejects a first liquid from a first outlet, a second ejection head which ejects a second liquid from a second outlet, a pressure control unit which controls the pressure inside the first ejection head and the second ejection head individually, and a suction unit which sucks the first outlet and the second outlet, wherein the pressure control unit controls the pressure inside the first ejection head before the first outlet is sucked by the suction unit and the pressure inside the second ejection head before the second outlet is sucked by the suction unit to be different pressure values ​​depending on the difference in volatility between the first liquid and the second liquid. Effect of the Invention

[0009] According to the present invention, for example, it is possible to provide a liquid ejection device that is advantageous for preventing foreign matter from remaining in the vicinity of the ejection port and maintaining the quality of the liquid application. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a liquid ejection device. [Diagram 2] 5 is a flowchart showing an operation sequence of the liquid ejection device. [Diagram 3] Schematic diagram showing an example of application of materials for a functional element. [Figure 4] FIG. 13 is a diagram showing a state after pressure is applied to the ejection head. [Diagram 5] FIG. 2 is a diagram showing the configuration of a recovery unit. [Figure 6] FIG. 4 is a diagram for explaining settings of the pressure of a first ejection head and the pressure of a second ejection head. [Figure 7] FIG. 4 is a diagram for explaining a sequence of pressure control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0012] The basic configuration and operation principle of the liquid ejection device 1 will be described with reference to FIG. 1. In the specification and drawings, directions are shown in an XYZ coordinate system in which a plane parallel to a plane on which a substrate is arranged is the XY plane, as shown in FIG. 1. The liquid ejection device 1 includes a substrate stage 3 that holds and moves a substrate 2. The substrate 2 is appropriately selected from a glass substrate, a plastic substrate, and the like, depending on the target product to be manufactured. The substrate 2 is typically a plate-like member, but is not limited to a specific form as long as it can function as a substrate. The substrate 2 may be, for example, a deformable (flexible) film. The substrate 2 may be rectangular or circular. The substrate 2 has a pixel area 201 for applying liquid to form an array of a large number of display pixels, and an evaluation area 202 into which liquid is experimentally ejected to evaluate the state of the liquid.

[0013] The liquid ejection device 1 has a plurality of ejection heads 36 capable of ejecting liquid stored therein toward a predetermined position on the substrate 2. The liquid is, for example, ink. Thus, the liquid ejection device may be called an inkjet device. The "ink" is a liquid used to form a pattern or a film on the substrate 2. In this specification, there is no particular limitation on the components of the ink, but for example, the ink may be a liquid composition containing a solute and a solvent to form an organic film.

[0014] The multiple ejection heads 36 may include a first ejection head 5 that contains a first liquid 25, and a second ejection head 30 that contains a second liquid 26 that is more volatile than the first liquid 25. The first ejection head 5 and the second ejection head 30 are arranged in, for example, the Y direction. The liquid ejection device 1 includes a first liquid tank 7 that stores the first liquid 25, and a first liquid supply system 6 that supplies the first liquid 25 stored in the first liquid tank 7 to the first ejection head 5. The liquid ejection device 1 also includes a second liquid tank 29 that stores the second liquid 26, and a second liquid supply system 35 that supplies the second liquid 26 stored in the second liquid tank 29 to the second ejection head 30. The liquid ejection device 1 also includes a recovery unit 8 that performs a cleaning process or the like on the multiple ejection heads 36 to recover the ejection characteristics. By individually controlling the ejection of liquid from each ejection head, a desired distribution of liquid can be applied to the pixel area 201 on the substrate 2.

[0015] When the substrate 2 is mounted on the substrate stage 3, a placement error of the substrate 2 may occur. Furthermore, as the substrate 2 undergoes various manufacturing processes, shape distortion may occur in the substrate 2 in the XY directions. The alignment scope 9 measures the position of the substrate 2 and the amount of distortion of the substrate 2. Furthermore, since there is manufacturing variation in the thickness of the substrate 2, when liquid is discharged from the multiple discharge heads 36 while scanning the substrate stage 3 in the Y direction, variation in the thickness of the substrate 2 may cause variation in the landing positions of the droplets on the substrate 2. For this reason, the liquid discharge device 1 also includes a height sensor 10 that measures the position (height) of the substrate 2 in the Z direction.

[0016] The first ejection head 5 and the second ejection head 30 each have at least one ejection port (nozzle) for ejecting liquid. In the following, the ejection port of the first ejection head 5 is referred to as a first ejection port 19, and the ejection port of the second ejection head 30 is referred to as a second ejection port 27. Furthermore, the surfaces on which the first ejection port 19 and the second ejection port 27 are provided are referred to as a first ejection port surface 20 and a second ejection port surface 28, respectively.

[0017] The liquid ejection device 1 has a pressure control unit 12. The pressure control unit 12 can individually control the pressure inside the first ejection head 5 for ejecting the first liquid 25 and the pressure inside the second ejection head 30 for ejecting the second liquid 26. The pressure control unit 12 can include pipes, pumps, and valves (not shown). The first liquid tank 7 and the second liquid tank 29 are connected to a pump via pipes and valves. The first liquid tank 7 and the second liquid tank 29 may be connected to one pump or to separate pumps. The pressure of the liquid surface of the first liquid tank 7 and the second liquid tank 29 can be adjusted by performing negative pressure control in which the pump sucks the space inside the first liquid tank 7 and the second liquid tank 29 by adjusting the valve. This negative pressure control allows the liquid inside each ejection head to form a meniscus near the opening of the ejection port and become in a state suitable for ejection, and it is possible to suppress the liquid from leaking at an unintended timing. In one example, the pressure control unit 12 controls the pressure of the meniscus to be 0.3 to 2.0 kPa lower than atmospheric pressure (negative pressure).

[0018] During ejection or standby, foreign matter may adhere to the vicinity of the opening of the ejection port, or the liquid may thicken near the opening of the ejection port, causing problems such as ejection failure and quality degradation. In this case, the pressure control unit 12 controls the pressure inside each ejection head to a pressure higher than atmospheric pressure, thereby making it possible to expel the liquid or foreign matter inside the ejection port. In one example, the pressure control unit 12 controls the pressure of the meniscus to be a pressure (positive pressure) 5 to 50 kPa higher than atmospheric pressure.

[0019] The control unit 11 controls each unit of the liquid ejection device 1 to supervise patterning on the substrate 2. The control unit 11 can be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), or an ASIC (abbreviation for Application Specific Integrated Circuit), or a general-purpose computer with a built-in program, or a combination of all or part of these.

[0020] The operation sequence of the liquid ejection device 1 will be described with reference to FIG. 2. In S201, the control unit 11 controls a substrate transport device (not shown) to load the substrate 2 into the liquid ejection device 1. In S202, the control unit 11 performs a recovery determination for the first ejection port 19 of the first ejection head 5 and the second ejection port 27 of the second ejection head 30. The recovery determination is performed by detecting ejection defects and quality disturbances of the first ejection port 19 of the first ejection head 5 and the second ejection port 27 of the second ejection head 30. If it is determined that recovery is necessary in the recovery determination, in S203, the control unit 11 controls the recovery unit 8 to perform a nozzle recovery process. The nozzle recovery process may include a process of discharging liquid and foreign matter from inside the ejection port to the outside by controlling the pressure inside the ejection head to a pressure higher than atmospheric pressure by the pressure control unit 12.

[0021] In S204, the control unit 11 controls the substrate stage 3 and the alignment scope 9 to perform alignment measurement of the substrate 2. In S205, the control unit 11 controls the substrate stage 3 and the height sensor 10 to perform height measurement of the substrate 2. The order of the alignment measurement in S204 and the height measurement in S205 may be reversed. Information on the position, distortion amount, and height of the substrate 2 obtained by the alignment measurement and the height measurement is stored in, for example, a memory in the control unit 11. The control unit 11 obtains discharge control information based on pixel data including information such as pixel arrangement and pixel size formed on the substrate 2. The discharge control information includes information indicating a target application distribution of the liquid in the pixel area 12 and the evaluation area 13 on the substrate 2.

[0022] In S206, the control unit 11 performs a recovery determination for each ejection head. The recovery determination is performed in the same manner as in S202. If any nozzle is determined to have an ejection defect in this recovery determination, in S207, the control unit 11 executes a nozzle recovery process for that nozzle.

[0023] In S208, the control unit 11 controls the ejection of liquid by the multiple ejection heads 36 based on the target application distribution while synchronously driving the ejection head 5 and the substrate stage 3. In order to form a large number of functional elements on the substrate using the liquid ejection device 1, the material of the functional elements is applied by scanning the application area to which the liquid is applied and the multiple ejection heads 36 relatively. FIG. 3 is a schematic diagram for explaining the application of the material of such functional elements. In FIG. 3, the substrate surface 101 is the surface of the substrate 2 on which the functional elements 102 are formed. The scanning is performed along the Y direction for each of rows A to E, for example. Since FIG. 3 is a schematic diagram, only 7×5 functional elements 102 are shown, but in reality, a very large number of functional elements can be formed. The scanning can be achieved by driving the substrate stage 3. Alternatively, the substrate stage 3 may be fixed, and the scanning may be performed by driving the multiple ejection heads 36, the alignment scope 9, and the like in the XY plane. Alternatively, scanning may be performed by driving the substrate stage 3, the multiple discharge heads 36, the alignment scope 9, and the like, respectively.

[0024] In S209, the control unit 11 determines whether or not the ejection to obtain the target coating distribution has been completed based on the ejection control information. If the ejection to obtain the target coating distribution has been completed, the process proceeds to S210. If not, the process returns to S206. In S210, the control unit 11 controls a substrate transport device (not shown) to transport the substrate 2 out of the liquid ejection device 1.

[0025] FIG. 4 shows a state in which liquid is pressurized and discharged from inside the discharge port in the liquid discharge device 1. The recovery unit 8 includes a tray 33 for liquid and foreign matter discharged from the first discharge port 19, and a tray 34 for liquid and foreign matter discharged from the second discharge port 27. When pressurizing and discharging liquid, the discharge heads 36 or the recovery unit 8 move so that the tray 33 is located directly below the first discharge port 19 and the tray 34 is located directly below the second discharge port 27. Most of the liquid and foreign matter discharged from the first discharge port 19 and the second discharge port 27 accumulate in the tray 33 and the tray 34, respectively, but some of the liquid and foreign matter adhere to the first discharge port surface 20 and the second discharge port surface 28. Hereinafter, the deposit attached to the first discharge port surface 20 is referred to as the first deposit 31, and the deposit attached to the second discharge port surface 28 is referred to as the second deposit 32.

[0026] The recovery unit 8 will be described with reference to Fig. 5. However, the trays 33 and 34 are omitted from Fig. 5. The recovery unit 8 is equipped with a suction port 13 that sucks the first attachment 31 and the second attachment 32. Note that the recovery unit 8 may be equipped with a plurality of suction ports, including a suction port that sucks the first attachment 31 and a suction port that sucks the second attachment 32. In this way, the recovery unit 8 functions as a suction unit. Hereinafter, the surface of the suction port 13 (the surface on which the suction port 13 is formed) will be referred to as the suction port surface 23.

[0027] The flow rate control unit 14 controls the flow rate at which liquid is sucked from the suction port 13. The drive system 15 moves the suction port 13 parallel to the first outlet surface 20 and the second outlet surface 28. The drive system 21 moves the suction port 13 perpendicular to the first outlet surface 20 and the second outlet surface 28. The distance control unit 22 controls the distance between the first outlet surface 20 and the second outlet surface 28 and the suction port surface 23. The distance control unit 22 brings the first outlet surface 20 and the second outlet surface 28 closer to the suction port surface 23, and the flow rate control unit 14 controls the flow rate at which liquid is sucked from the suction port 13, thereby making it possible to suck in the first deposit 31 and the second deposit 32. In one example, the flow rate control unit 14 sets the flow rate of the liquid sucked from the suction port 13 to 10 L / min or more, and the distance control unit 22 sets the distance between the first outlet surface 20 and the second outlet surface 28 and the suction port surface 23 to 200 μm or more and 600 μm or less. In this way, the suction unit is configured to suck the first outlet 19 and the second outlet 27 in a non-contact manner.

[0028] Next, referring to FIG. 6, pressure control of the discharge head after pressurization and discharge will be described. After pressurization and discharge of the liquid inside the multiple discharge heads 36, adhesions remain on the first discharge port surface 20 and the second discharge port surface 28. Here, it is considered that the first adhesions 31 and the second adhesions 28 are sucked by the suction port 13. In order to suck by the suction port 13, it is necessary to prevent the first adhesions 31 and the second adhesions 32 from drying after pressurization and discharge until the start of suction. This is because if the adhesions dry and remain as foreign matter near the discharge ports, the possibility of causing discharge defects increases. However, the second adhesions 32 are more volatile than the first adhesions 31 and are more likely to dry. Therefore, it is necessary to prevent drying by discharging more liquid from the second discharge port 27 than from the first discharge port 19. Therefore, the pressure inside the second discharge head 30 after pressurization and discharge (the second pressure value P2 in FIG. 6(b)) is made higher than the pressure inside the first discharge head 5 (the first pressure value P1 in FIG. 6(a)). Both P1 and P2 are pressures higher than atmospheric pressure. Preferably, the first pressure value P1 is set to a value such that the mass flow rate at which the first liquid 25 volatilizes (the change in mass per unit time) and the mass flow rate at which the first liquid 25 is discharged from the first outlet 19 are balanced. Similarly, the second pressure value P2 is set to a value such that the mass flow rate at which the second liquid 26 volatilizes and the mass flow rate at which the second liquid 26 is discharged from the second outlet 27 are balanced.

[0029] The pressure control unit 12 controls the pressure (pressure A) inside the first discharge head 5 before the first discharge port 19 is sucked by the recovery unit 8, and the pressure (pressure B) inside the second discharge head 30 before the second discharge port 27 is sucked by the recovery unit 8. Here, the pressure control unit 12 controls the pressure A and the pressure B to have different pressure values ​​according to the difference in volatility between the first liquid 25 and the second liquid 26.

[0030] A specific example of the sequence of pressure control by the pressure control unit 12 will be described with reference to FIG. 7. First, when a foreign object adheres near the opening of the ejection port or when the liquid near the opening of the ejection port thickens, the pressure inside the first ejection head 5 and the second ejection head 30 is set to an initial pressure value P0, which is a pressure (positive pressure) higher than atmospheric pressure, for example, 5 to 50 kPa. After being pressurized at the initial pressure value P0 in the pressurization period (first period), the pressure shifts to a suction waiting period (second period). In the suction waiting period, the pressure inside the first ejection head 5 is set to a first pressure value P1, which is a positive pressure lower than the initial pressure value P0 (FIG. 7(a)), and the pressure inside the second ejection head 30 is set to a second pressure value P2 (FIG. 7(b)). Both the first pressure value P1 and the second pressure value P2 are higher than atmospheric pressure, and the second pressure value P2 is higher than the first pressure value P1. Thereafter, the period shifts to a suction period (third period) in which the first outlet 19 and the second outlet 27 are sucked by the recovery unit 8. That is, the suction wait period (second period) is the period up to the point in time when the first outlet 19 and the second outlet 27 are sucked by the recovery unit 8. During the suction wait period, the internal pressures of the first outlet 19 and the second outlet 27 are maintained at the first pressure value P1 and the second pressure value P2, respectively.

[0031] During the suction period (third period), the pressure inside the first discharge head 5 and the pressure inside the second discharge head 30 are both set to a third pressure value P3. The third pressure value P3 is a pressure lower than atmospheric pressure (i.e., a negative pressure). By setting P3 to a negative pressure, the liquid inside the first discharge port 19 and the second discharge port 27 is sucked out when the first deposit 31 and the second deposit 32 are sucked using the suction port 13, and it is possible to prevent the liquid from adhering to the first discharge port 19 and the second discharge port 27 and causing discharge defects.

[0032] According to this embodiment, the pressure inside the second discharge head 30 is increased until the second discharge port surface 28 is sucked by the recovery unit 8, and the pressure inside the first discharge head 5 is increased until the first discharge port surface 20 is sucked by the recovery unit 8. This makes it possible to prevent adhesions on the first discharge port surface 20 and the second discharge port surface 28 from drying. Preventing the adhesions from drying makes it possible to prevent foreign matter from remaining near the first discharge ports 19 and the second discharge ports 27, and makes it possible to maintain the quality of the liquid application.

[0033] The above-described liquid ejection apparatus can be incorporated into a substrate processing apparatus for processing substrates such as display panels and semiconductor substrates.

[0034] <Embodiment of the article manufacturing method> The article manufacturing method according to the embodiment of the present invention is suitable for manufacturing articles such as display panels for organic EL displays, microdevices such as semiconductor devices, and elements having fine structures. The article manufacturing method according to the present embodiment includes a step of discharging a liquid onto a substrate using the above-mentioned liquid discharge device to form a discharged liquid film, a step of drying the substrate on which the discharged liquid film has been formed to obtain a substrate on which a dry film has been formed, and a step of manufacturing an article from the substrate on which the dry film has been formed. Furthermore, the article manufacturing method includes other well-known steps (baking, cooling, cleaning, oxidation, film formation, deposition, doping, flattening, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to conventional methods.

[0035] The disclosure of the present specification includes at least the following technical ideas. (Item 1) a first ejection head that ejects a first liquid from a first ejection port; a second ejection head that ejects a second liquid from a second ejection port; a pressure control unit that individually controls the internal pressures of the first ejection head and the second ejection head; a suction unit that suctions the first outlet and the second outlet; having the pressure control unit controls a pressure inside the first ejection head before the first ejection port is sucked by the suction unit and a pressure inside the second ejection head before the second ejection port is sucked by the suction unit to have different pressure values ​​according to a difference in volatility between the first liquid and the second liquid. A liquid ejection device comprising: (Item 2) The liquid ejection device described in item 1, characterized in that when the volatility of the second liquid is higher than the volatility of the first liquid, the pressure control unit makes the pressure inside the second ejection head higher than the pressure inside the first ejection head before the second ejection outlet is sucked by the suction unit. (Item 3) The pressure control unit is In a first period, a pressure inside the first ejection head and a pressure inside the second ejection head are set to an initial pressure value that is a positive pressure; In a second period following the first period, the pressure inside the first ejection head is set to a first pressure value that is a positive pressure lower than the initial pressure value, and the pressure inside the second ejection head is set to a second pressure value that is higher than the first pressure value; during a third period in which the suction unit sucks the first discharge port and the second discharge port after the second period, the pressure inside the first discharge head and the pressure inside the second discharge head are set to a third pressure value which is a negative pressure. 3. The liquid ejection device according to item 2, (Item 4) 4. The liquid ejection device according to item 3, wherein the second period is a period up to a point in time when the suction unit starts suctioning the first outlet and the second outlet. (Item 5) the first pressure value is set to a value such that a mass flow rate at which the first liquid volatilizes and a mass flow rate at which the first liquid is discharged from the first outlet are balanced; the second pressure value is set to a value such that a mass flow rate at which the second liquid volatilizes and a mass flow rate at which the second liquid is discharged from the first outlet are balanced. 5. The liquid ejection device according to item 3 or 4. (Item 6) 6. The liquid ejection device according to any one of items 1 to 5, wherein the suction unit is configured to suck the first ejection port and the second ejection port in a non-contact manner. (Item 7) The suction unit includes: a suction port that sucks liquid adhering to the first discharge port and the second discharge port; a flow rate control unit that controls a flow rate of the liquid sucked from the suction port; a distance control unit that controls a distance between the first outlet and the suction port and between the second outlet and the suction port; 7. The liquid ejection device according to any one of items 1 to 6, comprising: (Item 8) The flow rate control unit sets the flow rate of the liquid sucked from the suction port to 10 L / min or more, The distance control unit sets the distance to 200 μm or more and 600 μm or less. 8. The liquid ejection device according to item 7, (Item 9) A substrate processing apparatus for processing a substrate, a stage for holding and moving the substrate; A liquid ejection apparatus according to any one of items 1 to 8, which ejects liquid onto the substrate held by the stage; A substrate processing apparatus comprising: (Item 10) Discharging a liquid onto a substrate using the substrate processing apparatus according to item 9 to form a liquid film; drying the substrate on which the liquid film is formed to form a dry film; manufacturing an article from the substrate onto which the dry film is discharged; A method for manufacturing an article, comprising:

[0036] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0037] 1: liquid ejection device, 2: substrate, 3: substrate stage, 5: first ejection head, 7: first liquid tank, 8: recovery unit, 11: control unit, 12: pressure control unit, 19: first ejection port, 25: first liquid, 26: second liquid, 27: second ejection port, 30: second ejection head,

Claims

1. a first ejection head that ejects a first liquid from a first ejection port; a second ejection head that ejects a second liquid from a second ejection port; a pressure control unit that individually controls the internal pressures of the first ejection head and the second ejection head; a suction unit that suctions the first outlet and the second outlet; having the pressure control unit controls a pressure inside the first ejection head before the first ejection port is sucked by the suction unit and a pressure inside the second ejection head before the second ejection port is sucked by the suction unit to have different pressure values ​​according to a difference in volatility between the first liquid and the second liquid. A liquid ejection device comprising:

2. The liquid ejection device according to claim 1, characterized in that when the volatility of the second liquid is higher than the volatility of the first liquid, the pressure control unit makes the pressure inside the second ejection head higher than the pressure inside the first ejection head before the second ejection outlet is sucked by the suction unit.

3. The pressure control unit is In a first period, a pressure inside the first ejection head and a pressure inside the second ejection head are set to an initial pressure value that is a positive pressure; In a second period following the first period, a pressure inside the first ejection head is set to a first pressure value that is a positive pressure lower than the initial pressure value, and a pressure inside the second ejection head is set to a second pressure value that is higher than the first pressure value; during a third period in which the suction unit sucks the first ejection port and the second ejection port after the second period, the pressure inside the first ejection head and the pressure inside the second ejection head are set to a third pressure value which is a negative pressure. The liquid ejection device according to claim 2 .

4. The liquid ejection device according to claim 3 , wherein the second period is a period up to a point in time when the suction unit starts suctioning the first ejection port and the second ejection port.

5. the first pressure value is set to a value such that a mass flow rate at which the first liquid volatilizes and a mass flow rate at which the first liquid is discharged from the first outlet are balanced; the second pressure value is set to a value such that a mass flow rate at which the second liquid volatilizes and a mass flow rate at which the second liquid is discharged from the first discharge port are balanced.

4. The liquid ejection device according to claim 3.

6. The liquid ejection device according to claim 1 , wherein the suction unit is configured to suck the first ejection port and the second ejection port in a non-contact manner.

7. The suction unit includes: a suction port that sucks liquid adhering to the first discharge port and the second discharge port; a flow rate control unit that controls a flow rate of the liquid sucked from the suction port; a distance control unit that controls a distance between the first outlet and the suction port and between the second outlet and the suction port; The liquid ejection device according to claim 1 , further comprising:

8. The flow rate control unit sets the flow rate of the liquid sucked from the suction port to 10 L / min or more, The distance control unit sets the distance to 200 μm or more and 600 μm or less.

8. The liquid ejection device according to claim 7.

9. A substrate processing apparatus for processing a substrate, a stage for holding and moving the substrate; a liquid ejection apparatus according to claim 1 , which ejects liquid onto the substrate held by the stage; A substrate processing apparatus comprising:

10. A step of discharging a liquid onto a substrate by using the substrate processing apparatus according to claim 9 to form a liquid film; drying the substrate on which the liquid film is formed to form a dry film; manufacturing an article from the substrate onto which the dry film is discharged; A method for manufacturing an article, comprising:

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