Liquid dispensing device and imprinting device

Abstract

To inhibit a substance existing around a discharge surface from mixing into a cleaning fluid and causing harmful effect on a discharge port.SOLUTION: A liquid discharge device includes: a discharge head having a discharge surface formed with multiple discharge ports for discharging a liquid; and a cap which is detachably attached to the discharge head and forms a cleaning fluid holding space so that the cleaning fluid contacts with the discharge surface. The cap includes: a supply part for supplying the cleaning fluid to the holding space; and a discharge part for discharging the cleaning fluid from the holding space. The supply part is formed at a position facing the discharge surface and the discharge part is formed at a position at the outer side relative to the supply part in an inside-outside direction of the discharge surface.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a cleaning technique for discharge ports that discharge liquid.

Background Art

[0002] A so-called imprint technique is known as a technique applied to a manufacturing process of semiconductor devices and the like. In the imprint technique, for example, a mold having a pattern formed thereon is brought into contact with an imprint material on a substrate, and the shape of the mold is transferred to the imprint material to form a pattern. A liquid discharge device that discharges an imprint material onto a substrate includes a discharge head having a discharge surface on which a plurality of discharge ports for discharging the imprint material are formed. In order to maintain the discharge performance of the discharge ports, a technique for cleaning the discharge ports with a cleaning liquid has been proposed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a method of cleaning a discharge port with a cleaning liquid, substances present around the discharge surface may mix into the cleaning liquid and have an adverse effect (secondary contamination) on the discharge port.

[0005] The present invention provides a technique for suppressing substances present around the discharge surface from mixing into the cleaning liquid and having an adverse effect on the discharge port.

Means for Solving the Problems

[0006] According to the present invention, a discharge head having a discharge surface on which a plurality of discharge ports for discharging liquid are formed, A cap is detachably attached to the discharge head and forms a space for holding the cleaning liquid so that the cleaning liquid comes into contact with the discharge surface. The pressure inside the discharge head is adjusted to negative and positive pressure. Pressure control unit and, A pump that supplies cleaning solution to the aforementioned cap, A liquid dispensing device equipped with, The aforementioned cap is A supply unit for supplying cleaning liquid to the holding space, It includes a discharge section for discharging cleaning liquid from the holding space, The supply unit is formed at a position facing the discharge surface, The discharge section is formed in a position outside the supply section in the inward-outward direction of the discharge surface, The aforementioned Pressure control unit With the pressure of the discharge head in a positive state, the pump supplies the cleaning solution to the cap attached to the discharge head, and when supplying the cleaning solution... Pressure control unit The pressure from the pump is greater than the pressure from the pump. A liquid dispensing device characterized by the above is provided. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technology that suppresses the mixing of substances present around the discharge surface into the cleaning solution and adversely affecting the discharge port. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing the configuration of an imprinting device. [Figure 2] A diagram showing the configuration of the liquid dispensing section. [Figure 3] A magnified cross-sectional view of a portion of the discharge head. [Figure 4] A diagram showing the configuration of the cleaning device. [Figure 5] (A) is a top view of the cap, and (B) is a bottom view of the discharge head. [Figure 6] A flowchart of the cleaning process. [Figure 7](A) and (B) are diagrams showing other configuration examples of the cap. [Figure 8] A diagram showing another example configuration of the cleaning device. [Figure 9] A diagram showing yet another example configuration of the cleaning device. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0010] <First Embodiment> <Overview of Imprint Devices> Figure 1 is a schematic diagram showing the configuration of an imprint apparatus 101 according to one embodiment of the present invention. In the figure, arrow Z indicates the vertical direction, and arrows X and Y indicate the horizontal direction which is perpendicular to each other. The imprint apparatus 101 is used for manufacturing various devices such as semiconductor devices. The imprint apparatus 101 is equipped with a liquid dispensing device 130. The liquid dispensing device 130 is equipped with a liquid dispensing unit 10 and a cleaning unit 80. The liquid dispensing unit 10 dispenses a liquid (in this case, a resist) 114 onto a substrate 111. The liquid 114 is, for example, a photocurable resin that hardens when exposed to ultraviolet (UV) light. The liquid 114 is appropriately selected depending on various conditions such as the semiconductor device manufacturing process. In addition to photocurable, for example, a thermosetting resist liquid may be used, and the imprint apparatus may be a device that hardens the resist with heat and performs the imprinting process. The liquid 114 may also be called the dispensing material or imprint material. The cleaning unit 80 is used to clean the liquid dispensing unit 10.

[0011] The imprint apparatus 101 also includes an optical irradiation unit 102, a mold holding mechanism 103, a substrate stage 104, a control unit 106, a measurement unit 122, and a housing 123.

[0012] The optical irradiation unit 102 includes a light source 109 and an optical element 110 for correcting the ultraviolet rays 108 irradiated from the light source 109. The light source 109 is, for example, a halogen lamp that generates i-line or g-line. The ultraviolet rays 108 are irradiated onto the liquid 114 through the mold (die) 107. The wavelength of the ultraviolet rays 108 is a wavelength corresponding to the liquid 114 to be cured. In the case of an imprint apparatus using a thermosetting resist as the resist, instead of the optical irradiation unit 102, a heat source unit for curing the thermosetting resist is installed.

[0013] The mold holding mechanism 103 includes a mold chuck 115 and a mold driving mechanism 116. The mold 107 held by the mold holding mechanism 103 has a rectangular outer peripheral shape and a pattern portion 107a on the surface facing the substrate 111, on which a three-dimensional uneven pattern such as a circuit pattern to be transferred is formed. The material of the mold 107 in the present embodiment is a material through which the ultraviolet rays 108 can penetrate, and for example, quartz is used. The mold chuck 115 holds the mold 107 by vacuum adsorption or electrostatic force.

[0014] The mold driving mechanism 116 moves the mold 107 by holding and moving the mold chuck 115. The mold driving mechanism 116 can move the mold 107 downward in the Z direction and press the mold 107 against the liquid 114. Also, the mold driving mechanism 116 can move the mold 107 upward in the Z direction and separate the mold 107 from the liquid 114. Examples of the actuator that can be adopted by the mold driving mechanism 116 include a linear motor or an air cylinder.

[0015] The mold chuck 115 and the mold drive mechanism 116 have an opening region 117 in the center. The mold 107 also has a concave cavity 107b on the surface to which ultraviolet light 108 is irradiated. A light-transmitting member 113 is installed in the opening region 117 of the mold drive mechanism 116, and a sealed space 112 is formed surrounded by the light-transmitting member 113, the cavity 107b, and the opening region 117.

[0016] The pressure within space 112 is controlled by a pressure compensation device (not shown). By setting the pressure within space 112 higher than the external pressure, the pressure compensation device causes the pattern portion 107a to bend convexly toward the substrate 111. This causes the center of the pattern portion 107a to come into contact with the liquid 114. Therefore, when the mold 107 is pressed into the liquid 114, the trapping of gas (air) between the pattern portion 107a and the liquid 114 is suppressed, and the liquid 114 can be filled into every corner of the uneven surface of the pattern portion 107a. The depth of the cavity 107b, which determines the size of space 112, is appropriately changed according to the size or material of the mold 107.

[0017] The substrate stage 104 includes a substrate chuck 119, a substrate stage housing 120, and a stage reference mark 121. The substrate 111 held by the substrate stage is a single-crystal silicon substrate or an SOI (Silicon on Insulator) substrate, and a liquid 114 is dispensed onto the surface of the substrate 111 to form a pattern.

[0018] The substrate chuck 119 holds the substrate 111 by vacuum suction. The substrate stage housing 120 moves the substrate 111 by moving in the X and Y directions while mechanically holding the substrate chuck 119. The stage reference mark 121 is used to set the reference position of the substrate 111 in the alignment of the substrate 111 with the mold 107. For example, a linear motor is used as the actuator of the substrate stage housing 120. Alternatively, the actuator of the substrate stage housing 120 may be configured to include multiple drive systems, such as a coarse drive system or a fine drive system.

[0019] The measurement unit 122 includes an alignment measuring instrument 127 and an observation measuring instrument 128. The alignment measuring instrument 127 measures the positional displacement in the X and Y directions between the alignment marks formed on the substrate 111 and the alignment marks formed on the mold 107. The observation measuring instrument 128 is an imaging device such as a CCD camera, which captures the pattern of the liquid 114 discharged onto the substrate 111 and outputs the image information to the control unit 106.

[0020] The control unit 106 controls the operation of each component of the imprint device 101, and in particular, controls the liquid ejection device 130. The control unit 106 is composed of a computer having a CPU, ROM, and RAM, for example. The control unit 106 is connected to each component of the imprint device 101 via a circuit, and the CPU controls each component according to a control program stored in the ROM. The control unit 106 also has a display unit and can display various information. Based on the measurement information from the measurement unit 122, the control unit 106 controls the operation of the mold holding mechanism 103, the substrate stage 104, and the liquid ejection unit 10. The housing 123 includes a base platen 124 on which the substrate stage 104 is placed, a bridge platen 125 for fixing the mold holding mechanism 103, and a support column 126 extending from the base platen 124 to support the bridge platen 125. The imprint apparatus 101 also includes a mold transport mechanism (not shown) for transporting the mold 107 from outside the apparatus to the mold holding mechanism 103, and a substrate transport mechanism (not shown) for transporting the substrate 111 from outside the apparatus to the substrate stage 104.

[0021] The imprint device 101 performs an imprint process that includes the following series of steps. First, the imprint device 101 dispenses liquid 114 onto the substrate 111 from the liquid dispensing unit 10. Then, it presses a mold 107 having a molding pattern onto the liquid 114 dispensed onto the substrate, and in that state, cures the liquid 114 by irradiation with light (ultraviolet light). After that, the mold 107 is separated from the cured liquid 114, thereby transferring the pattern of the mold 107 onto the substrate 111.

[0022] <Liquid discharge part> Figure 2 shows the configuration of the liquid discharge unit 10. The liquid discharge unit 10 includes a discharge head 11, a storage container 12, a pressure control unit 13, and a circulation unit 14. The storage container 12 contains liquid 114. The internal space of the storage container 12 is connected to the pressure control unit 13 by piping 16. The pressure control unit 13 includes a tank for storing the filling liquid, a pressure sensor, and a valve for opening and closing the connecting piping 16, and is configured to control the pressure in the internal space of the storage container 12. By controlling the pressure of the liquid in the internal space of the storage container 12 with the pressure control unit 13, the reproducibility of liquid discharge can be improved.

[0023] In this embodiment, the internal space of the containment container 12 is treated as a single space, and its pressure is controlled by the pressure control unit 13. However, the internal space may be divided into two spaces by a separation membrane. In this case, one space is connected to the discharge head 11, and the other space is connected to the pressure control unit 13 via piping 16, and the liquid pressure is controlled via the separation membrane.

[0024] The circulation unit 14 includes a flow path (pipe) 141 and connectors 142 and 143 that connect both ends of the flow path 141 to the internal space of the containment container 12. A pump 144 and a filter 145 are provided on the flow path 141. By driving the pump 144, the liquid 114 in the containment container 12 can be circulated through the flow path 141. Foreign matter is removed by the filter 145 as the liquid 114 passes through the flow path 141. The filter 145 is positioned downstream of the pump 144 in the flow direction of the liquid 114. Even if dust generated by the pump 144 mixes with the liquid, it is removed by the filter 144.

[0025] The discharge head 11 discharges liquid 114 from its bottom surface 11a. Figure 3 is a partially enlarged cross-sectional view of the discharge head 11. The discharge head 11 comprises a common liquid chamber 56 and a module substrate 57. The module substrate 57 comprises a plurality of nozzles 54. Each nozzle 54 has a supply port 21 that opens to the top surface 59 and takes in liquid 114, and a discharge port 19 that discharges the liquid 114. The module substrate 57 has a discharge surface 58, and each discharge port 19 opens to the discharge surface 58. Inside the nozzle 54, an energy element 18 is provided that generates energy for discharging the liquid 114. The opening area of ​​the discharge port 19 is smaller than the opening area of ​​the supply port 21, and the cross-sectional area of ​​the flow path in the discharge nozzle 54 is minimized. In this embodiment, the energy element 18 is a piezoelectric element, such as a piezo element, but a heat-generating resistor can also be used depending on the type of liquid 114. In addition, a configuration in which the discharge and stopping of the liquid is controlled using a control valve or the like can also be adopted.

[0026] The supply port 21 communicates with the discharge port 19 and the small liquid chamber 20 inside the module board 57. The energy element 18 is controlled by the control unit 106 via the drive circuit 90. By changing the volume of the small liquid chamber 20 with the energy element 18, the liquid 114 in the small liquid chamber 20 is discharged from the discharge port 19. The discharge head 11 may have a configuration similar to that of an ink discharge head used in an inkjet printer.

[0027] The discharge head 11 is open to the atmosphere through the discharge port 19, but the diameter of the discharge port 19 is several μm to more than ten μm, so the liquid 114 does not leak out due to its own gravity by capillary action. The liquid surface near the discharge port 19 is maintained in a concave, so-called meniscus state. The meniscus state can be stably maintained by keeping the internal pressure of the liquid 114 in the small liquid chamber 20 at a negative pressure of -0.1 to -1000 Pa by the pressure control unit 13. The discharge surface 58 is treated with a liquid-repellent coating to reliably prevent the liquid 114 from leaking out of the discharge port 19. As an example of a liquid-repellent coating, a fluorine-containing compound can be applied to the discharge surface 58 in a film-like manner.

[0028] The diameter of the discharge port 19 is several micrometers. Ra Ju If the diameter is small, such as a few micrometers, the discharge performance will decrease if particles adhere to the inside of the discharge port 19 or if some of the components contained in the liquid 114 dry and solidify around the discharge port 19. Examples of decreased discharge performance include no discharge at all, as well as fluctuations in discharge volume and direction. If such a decrease in discharge performance occurs, the discharge port 19 is cleaned by the cleaning unit 80.

[0029] <Detection of liquid discharge status> The energy element 18 can also be used to detect the liquid discharge state of the discharge port 19. The energy element 18 is driven with a voltage intensity of 30% to 70% of the voltage applied when discharging the liquid 114, causing the volume of the small liquid chamber 20 to fluctuate (hereinafter referred to as test oscillation), and applying vibration to the liquid 114 in the small liquid chamber 20. For example, if a drive pulse of ±10V is applied to the energy element 18 when discharging the liquid 114 from the discharge port 19, a drive pulse of ±6V is applied to the energy element 18. In other words, the energy element 18 is driven to the extent that the liquid 114 is not discharged by breaking the meniscus of the discharge port 19, and vibration is applied to the liquid 114 in the small liquid chamber 20.

[0030] Even when the energy element 18 is stopped, a back electromotive force is generated in the energy element 18 due to the residual vibration of the liquid 114. This back electromotive force is detected by a sensor 91 provided at each discharge port 19. The sensor 91 is, for example, a voltage sensor or a current sensor. If a discharge port 19 is blocked by contaminants or if air bubbles enter the small liquid chamber 20, the waveform of the back electromotive force will differ from the standard state (waveform when a meniscus is formed). In other words, the energy element 18 outputs a signal corresponding to the liquid discharge state of the corresponding discharge port 19. This signal allows for the individual detection of the liquid discharge state of each discharge port 19.

[0031] In this example, we have described how the liquid discharge state is detected by the test oscillation of the energy element 18. However, the liquid discharge state of each discharge port 19 may also be detected individually by measuring the presence or absence of impact, as well as the impact position, velocity, and amount, using a projectile impact detection device (not shown).

[0032] This detection of the liquid discharge state is performed when the liquid discharge unit 10 is in a standby position for maintenance. If any abnormality, such as clogging, is detected in the liquid discharge state of each discharge port 19, a cleaning process is performed.

[0033] <Cleaning Section> Figure 4 is an explanatory diagram showing the configuration of the cleaning device 60 provided in the cleaning unit 80, illustrating the cleaning method for the discharge surface 58 of the discharge head 11. The cleaning device 60 is a device that cleans each discharge port 19 with cleaning liquid, and comprises a circulation device 61, a cap 64, and a filter 66. The cleaning liquid is, for example, a liquid similar to liquid 114, or a liquid using one of the materials contained in liquid 114. Multiple types of cleaning liquids may be used in a single cleaning; for example, cleaning may be performed using a liquid different from liquid 114 as the cleaning liquid, followed by cleaning using liquid 114 as the cleaning liquid.

[0034] The cap 64 is detachably attached to the discharge head 11. The circulation device 61 is a mechanism that circulates the cleaning liquid supplied to and discharged from the cap 64. The filter 66 is provided in the middle of the circulation path of the cleaning liquid and purifies the cleaning liquid. By circulating the cleaning liquid, the amount of cleaning liquid consumed can be reduced. In this embodiment, the cleaning liquid is circulated, but it may also be configured so that the cleaning liquid is consumed with each wash without circulation.

[0035] The circulation device 61 includes a tank T for storing cleaning fluid, piping 62 and 63, and a pump 65. Piping 62 connects the tank T and the cap 64, forming a flow path on the supply side of the cleaning fluid. Piping 63 connects the tank T and the cap 64, forming a flow path on the discharge side (recovery side) of the cleaning fluid. In this embodiment, the pump 65 is located in the middle of piping 62 and pumps the cleaning fluid to the cap 64. A filter 66 is located in the middle of piping 62 and downstream of the pump 65, and purifies the cleaning fluid flowing through piping 62. Even if dust generated by the pump 65 mixes with the cleaning fluid, it is removed by the filter 66.

[0036] The structure of the cap 64 and the bottom surface of the discharge head 11 will be described with reference to Figure 4, as well as Figures 5(A) and 5(B). A tile 75 is provided on the bottom surface 11a of the discharge head 11. The tile 75 holds a discharge surface 58 in which a plurality of discharge ports 19 are formed, a protective member 73 that protects the discharge surface 58, and a filler 74 that fills the gap between the discharge surface 58 and the protective member 73. The discharge surface 58 has a rectangular shape with a longer side in the X direction and a shorter side in the Y direction. In each figure, arrow D indicates the inward and outward direction of the discharge surface 58 (in this embodiment, the direction from the center to the periphery of the rectangle on the XY plane).

[0037] The cap 64 has a space for holding the cleaning fluid so that the cleaning fluid comes into contact with the discharge surface 58. SP It is a component that forms the cap. The cap 64 is, for example, a machined part made of PTFE resin that does not raise concerns about metal leaching. After processing and molding, the cap 64 can be used in a physically and chemically clean state by performing acid cleaning.

[0038] The cap 64 has a shape that surrounds the discharge surface 58, and in this embodiment, it has a rectangular parallelepiped shape overall. 64 It includes a rectangular base 64a and four side sections 64b rising from the base 64a, with an open top.

[0039] The cap 64 has an opposing surface (upper surface) 1 that faces the bottom surface 11a of the discharge head 11, and a rectangular parallelepiped-shaped groove 2 defining a holding space 20 is formed on the opposing surface 1. An O-ring type sealing member 5 is also provided on the opposing surface 1 so as to surround the groove 2. The cap 64 is mounted so that the opposing surface 1 is in contact with the bottom surface 11a of the discharge head 11, and the sealing member 5 is pressed against the tile 75 so that the cleaning liquid in the holding space 20 is released into the cap. 64 This prevents leakage to the outside. With regard to attaching the cap 64 to the discharge head 11, the cap 64 may be fixed to the discharge head 11 using a screw hole (not shown) provided in the tile 75.

[0040] With the cap 64 attached to the discharge head 11, the holding space SP is the discharge surface 58 It covers the entire thing. In other words, all the outlets 19 are within the holding space. SP Covered, holding space SP By filling it with cleaning solution, all of the outlets 19 can be cleaned.

[0041] holding space SP The pressure of the cleaning fluid being pumped to the discharge head (let's call it P1) can be measured by a pressure gauge (not shown) on the pump 65. The relative magnitudes of pressure P1 and pressure P2 can be controlled by controlling the pressure inside the discharge head 11 (let's call it P2) with the pressure control device 13.

[0042] A supply section 3 and multiple discharge sections 4 are formed on the bottom wall surface 2a of the groove 2. In this embodiment, both the supply section 3 and the multiple discharge sections 4 are openings (holes) that open into the bottom wall surface 2a and penetrate the bottom 64a of the cap 64. The supply section 3 is connected to the piping 62, and the multiple discharge sections 4 are connected to the piping 63. The cleaning liquid pumped from the pump 65 is supplied to the holding space 20 via the supply section 3, and to the holding space via the multiple discharge sections 4. SP It is discharged from.

[0043] Figure 5(B) shows the positions of the supply unit 3 and the multiple discharge units 4 relative to the discharge surface 58 with the cap 64 attached to the discharge head 11, indicated by dashed lines. The supply unit 3 is formed in a position opposite the discharge surface 58, and in the illustrated example in particular, the supply unit 3 is formed in a position opposite the center of the discharge surface 58 in the X and Y directions. On the other hand, each discharge unit 4 is formed in a position outside the supply unit 3 in the inward / outward direction D of the discharge surface 58.

[0044] This arrangement creates a holding space SP The cleaning solution inside is shown in the diagram. 4As illustrated by the arrows, the cleaning liquid flows from the supply section 3 to the discharge section 4. Since the cleaning liquid flows from the inside to the outside on the discharge surface 58, flow from the outside to the inside is suppressed. Therefore, it is possible to prevent contaminants attached to the protective member 73 and the filler 74 from flowing with the cleaning liquid and adhering to the discharge surface 58, and to prevent the cleaning liquid contaminated by the cleaning from remaining on the discharge surface 58. Thus, according to this embodiment, it is possible to suppress substances present around the discharge surface 58 from mixing with the cleaning liquid and adversely affecting the discharge port 19.

[0045] In this embodiment, the supply unit 3 has an opening narrower than the width of the discharge surface 58 in the Y direction, and the holding space is accessible from the supply unit 3. SP The cleaning fluid supplied to the inside flows radially outward on the discharge surface 58. This enhances the cleaning effect of each discharge port 19 and effectively suppresses the flow of the cleaning fluid from the outside to the inside of the discharge surface 58. Furthermore, it prevents the cleaning fluid supplied from the supply unit 3 into the holding space 20 from flowing directly onto components outside the discharge surface 58 (protective member 73 and filler 74).

[0046] In this embodiment, the two discharge sections 4 are spaced apart in the X direction, and the supply section 3 is located between the two discharge sections 4, particularly in the middle. This promotes the flow of cleaning fluid from the supply section 3 to each discharge section 4 and effectively suppresses the flow of cleaning fluid from the outside to the inside of the discharge surface 58. In particular, in this embodiment, each discharge section 4 is formed in a position that does not face the discharge surface 58, in other words, outside the discharge surface 58. This arrangement further effectively suppresses the flow of cleaning fluid from the outside to the inside of the discharge surface 58.

[0047] <Example of cleaning control> An example of the procedure for cleaning the discharge port 19 using the cleaning device 60 will be explained with reference to Figure 6. First, in step S1, the cap 64 is attached to the discharge head 11. As shown in Figure 4, the cap 64 is positioned opposite the discharge surface 58, and the cap 64 is attached to the discharge head 11 such that the opposing surface 1 of the cap 64 contacts the bottom surface 11a of the discharge head 11.

[0048] In step S2, the pressure control unit 13 adjusts the pressure P2 to a positive pressure. When the pump 65 is driven and the pressure P1 rises, the cleaning fluid may flow back from the holding space 20 into the discharge port 19. Therefore, the pressure P2 is adjusted in advance so that when the pump 65 is driven, the relationship P2 > P1.

[0049] In step S3, the pump 65 is driven, and the holding space SP A cleaning solution is supplied to the nozzles. Each outlet 19 is cleaned with the cleaning solution. The cleaning solution is circulated between the cap 64 and the tank T via the supply unit 3 and multiple discharge units 4. Since the cleaning solution is purified by the filter 66, the amount of cleaning solution consumed can be reduced even when cleaning is performed for a long time.

[0050] Each energy element 18 may be driven during cleaning. By driving the energy elements 18, the cleaning effect can be improved by vibrating the cleaning liquid in the nozzle 54 and the cleaning liquid in the holding space 20. The normal conditions for this vibration-based cleaning may be the voltage and frequency used in the normal discharge operation. If the attached contaminants cannot be removed under normal conditions, the contaminant removal effect can be enhanced by increasing the voltage applied to the energy elements 18 by about 20% to 40% and the vibration frequency by 30kHz to 50kHz compared to the normal discharge operation. Furthermore, the longer the vibration-based cleaning time, the more effective it is, and the cleaning effect can be further enhanced by performing it for several hours to several days.

[0051] In step S4, after the cleaning is complete, the liquid discharge status of each discharge port 19 is detected. The detection method is as described above. If a discharge failure is detected, the cleaning process is repeated in step S6. If no discharge failure is detected, the cleaning process is completed.

[0052] <Second Embodiment> Other examples of the configuration and arrangement of the supply unit 3 and the discharge unit 4 will be described. Figure 7(A) shows an example in which a porous member with a large number of holes 3a formed in the supply unit 3 is used. The porous member may be a processed product in which a large number of holes 3a are formed in a plate-like member, or it may be a member that has a large number of holes due to the properties of the material, such as a porous material.

[0053] Figure 7(B) shows another example. In the illustrated example, the discharge section 4 is formed as an annular opening that surrounds the supply section 3. This allows the cleaning liquid from the supply section 3 to spread more easily in a radial manner, and prevents contaminants from flowing from the outside to the inside along with the cleaning liquid in any direction of the discharge surface 58. In the example of the discharge section 4 in Figure 7(B), an annular groove may be used instead of an annular opening, and part of the groove may be in communication with the piping 63. Also, in the example of Figure 7(B), a porous member is used as an example of the configuration of the supply section 3, similar to Figure 7(A), but it may be a single opening, similar to the first embodiment.

[0054] <Third Embodiment> As described in the first embodiment, the cleaning effect can be improved by driving each energy element 18 during cleaning, thereby vibrating the cleaning liquid in the nozzle 54 and the cleaning liquid in the holding space 20. In this case, the cleaning effect can be further improved by degassing the cleaning liquid. Figure 8 illustrates a cleaning apparatus 60 equipped with a degassing device 67.

[0055] In the example shown in Figure 8, the cleaning solution is degassed within the piping 62. The piping 62 has a double-walled structure consisting of an inner pipe 62a and an outer pipe 62b. The inner pipe 62a is made of a membrane-like gas-permeable material. The outer pipe 62b is a general piping material but has the strength to withstand reduced pressure. An exhaust duct 67c is connected to the outer pipe 62b, and a valve 67a and an exhaust device 67b such as a pump are connected to the exhaust duct 67c.

[0056] By opening valve 67a and driving exhaust device 67b, the pressure inside the outer tube 62b is reduced to, for example, about -90 kPa. This allows dissolved gases in the cleaning solution passing through the inner tube 62a to move between the inner tube 62a and the outer tube 62b, enabling the degassing of the cleaning solution. After the pressure is reduced, by closing valve 67a, the reduced pressure inside the outer tube 62b can be maintained even if the exhaust device 67b is stopped.

[0057] If the pressure P1 of the cleaning fluid changes due to the reduced pressure inside the outer tube 62b, the pressure control unit 13 controls the pressure P2 to maintain the state where pressure P2 > pressure P1. In this state, the pump 65 is driven to start supplying the cleaning fluid to the holding space 20 and circulating the cleaning fluid. Furthermore, by driving the energy generating element 18, the cleaning fluid inside the holding space 20 can be vibrated to enhance the cleaning effect.

[0058] In this configuration, the inner tube 62a is made of a gas-permeable material to degas the cleaning solution, but the degassing method is not limited to this. For example, the groove 2 of the cap 64 can be made of a double-wall structure, with the inner wall made of a gas-permeable material. Then, the cleaning solution in the holding space 20 can be degassed by reducing the pressure inside the outer wall. Considering the generation of bubbles in the filter 66, the position between the filter 66 and the cap 64 is advantageous for degassing the cleaning solution.

[0059] Examples of gas-permeable materials include perfluoroalkoxyalkanes (PFA), polytetrafluoroethylene (PTFE), polymethylpentene (PMP), and silicon.

[0060] The timing of degassing may be at a time other than the cleaning time. Furthermore, degassing may be started before the start of cleaning if a malfunction of the discharge port 19 is detected. Degassing may also be performed after a certain period of time has elapsed. Additionally, degassing may be triggered by a programmed command.

[0061] Next, we will describe an example of promoting degassing by heating the cleaning solution. Figure 9 shows the cleaning apparatus 60 of this embodiment, in which a heating device 68 is added to the configuration example in Figure 8. Generally, the solubility of gas in a liquid decreases as the liquid temperature increases, so when the temperature of the cleaning solution is high, dissolved gas is generated as bubbles. By keeping the temperature of the cleaning solution high with the heating device 68, the gas dissolved in the cleaning solution is moved between the inner tube 62a and the outer tube 62b through the inner tube 62a, which is a gas-permeable member, and degassing of the cleaning solution is possible. It is also possible to suppress the dissolution of new gas into the cleaning solution.

[0062] In the example shown in Figure 9, the cleaning solution is heated by heating the piping 62 with a heating device 68. However, the heating point is not limited to this. For example, it could be the tank T, the piping 63, or the cap 64. In any case, by designing the heating device 68 so that it does not come into direct contact with the cleaning solution, it is possible to prevent contaminants from the heating device 68 from mixing into the cleaning solution.

[0063] For heating, for example, a temperature 5°C or more higher than normal is maintained from the viewpoint of degassing effect. The heating temperature may be set according to the physical properties of the cleaning solution. After confirming the correlation between temperature and discharge accuracy in advance, the temperature of the cleaning solution may be monitored and the discharge parameters may be automatically adjusted according to the temperature.

[0064] <Other Embodiments> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0065] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0066] 3 supply unit, 4 discharge unit, 11 discharge head, 19 discharge port, 58 discharge surface, 60 cleaning device, 64 cap

Claims

1. A discharge head having a discharge surface formed with multiple discharge ports for discharging liquid, A cap is detachably attached to the discharge head and forms a space for holding the cleaning liquid so that the cleaning liquid comes into contact with the discharge surface. A pressure control unit that adjusts the pressure inside the discharge head to negative and positive pressure, A pump that supplies cleaning solution to the aforementioned cap, A liquid dispensing device equipped with, The aforementioned cap is A supply unit for supplying cleaning liquid to the holding space, It includes a discharge section for discharging cleaning liquid from the holding space, The supply unit is formed at a position facing the discharge surface, The discharge section is formed in a position outside the supply section in the inward-outward direction of the discharge surface, With the pressure control unit making the pressure at the discharge head positive, the pump supplies cleaning fluid to the cap attached to the discharge head, and the pressure from the pressure control unit when supplying the cleaning fluid is greater than the pressure from the pump. A liquid dispensing device characterized by the following features.

2. A liquid dispensing device according to claim 1, The supply section is formed of a porous member. A liquid dispensing device characterized by the following features.

3. A liquid dispensing device according to claim 1, The supply unit is formed at a position opposite the center of the discharge surface, A liquid dispensing device characterized by the following features.

4. A liquid dispensing device according to claim 3, The cap includes a first discharge section and a second discharge section as the discharge section. The supply unit is located between the first discharge unit and the second discharge unit. A liquid dispensing device characterized by the following features.

5. A liquid dispensing device according to claim 1, The supply unit has an opening narrower than the width of the discharge surface. A liquid dispensing device characterized by the following features.

6. A liquid dispensing device according to claim 1, The discharge section is formed in a position that does not face the discharge surface. A liquid dispensing device characterized by the following features.

7. A liquid dispensing device according to claim 1, The discharge section is formed in an annular shape so as to surround the plurality of discharge ports. A liquid dispensing device characterized by the following features.

8. A liquid dispensing device according to claim 1, The aforementioned cap is The opposing surface facing the discharge head, A groove formed on the opposing surface that defines the holding space, A sealing member provided on the opposing surface so as to surround the groove, The supply section and the discharge section are opening to the bottom wall surface of the groove. A liquid dispensing device characterized by the following features.

9. A liquid dispensing device according to claim 1, A tank for storing the cleaning solution, A circulation means for circulating the cleaning solution between the tank and the holding space via the supply unit and the discharge unit, A filter installed in the middle of the cleaning solution circulation path, A liquid dispensing device characterized by the following features.

10. A liquid dispensing device according to claim 1, Each outlet is provided with an element that outputs a signal corresponding to the liquid discharge state of the outlet. A liquid dispensing device characterized by the following features.

11. A liquid dispensing device according to claim 1, Each outlet is provided with an element that discharges liquid from the outlet, The element is driven during cleaning with the cleaning solution. A liquid dispensing device characterized by the following features.

12. A liquid dispensing device according to claim 1, Includes a degassing means for degassing the cleaning solution, A liquid dispensing device characterized by the following features.

13. A liquid dispensing device according to claim 1, Includes a heating means for heating the cleaning solution, A liquid dispensing device characterized by the following features.

14. A liquid dispensing device according to claim 10, The aforementioned element is a piezoelectric element, The piezoelectric element generates a back electromotive force and outputs a signal corresponding to the liquid discharge state of the discharge port. A liquid dispensing device characterized by the following features.

15. An imprint apparatus that performs imprint processing on a substrate by discharging liquid from a liquid discharging device as described in claim 1.

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