Liquid discharge device and article manufacturing method

Abstract

To provide a technique that is advantageous for maintaining accuracy in measuring a position of a head that discharges liquid droplets, in a liquid discharge device.SOLUTION: A liquid discharge device which discharges liquid onto a substrate comprises a head having a plurality of discharge holes for discharging liquid droplets, a holder holding the head, and a cleaning mechanism that cleans the head held by the holder. The holder is provided with a mark part having a mark that is detected in measuring a relative position between the holder and the head, and the cleaning mechanism operates to clean the head and also the mark part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device and an article manufacturing method. [Background technology]

[0002] In recent years, when manufacturing various functional elements, attempts have been made to form patterns on substrates (patterning) using liquid ejection devices that eject (supply) liquid, which will be the material for the functional elements, as droplets onto the substrate using the inkjet method.Patterning using such liquid ejection devices has the advantages of being able to perform on-demand patterning, resulting in high material usage efficiency, being a non-vacuum process that allows for relatively small manufacturing equipment, and being able to coat large areas at high speeds.

[0003] Patent Document 1 describes a liquid ejection device having a head unit to which multiple heads that eject droplets are attached. The head unit in Patent Document 1 is provided with a marker member that is detected (imaged) by a camera to define a reference point and a reference axis of the head unit. This marker member is used not only to identify the position and orientation of the head unit, but also to measure the attachment position of the head in the head unit (i.e., the position of the nozzles formed in the head). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-18626 Summary of the Invention [Problem to be solved by the invention]

[0005] From the viewpoint of improving the measurement accuracy of the head (nozzle) position, it is preferable to place the mark such as the marking member in Patent Document 1 near the head. However, if the mark is placed near the head, the mark may be contaminated by the liquid ejected from the head. In this case, the mark cannot be detected accurately, and the measurement accuracy of the head position may decrease.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a technique that is advantageous for maintaining the measurement accuracy of the position of a head that ejects liquid droplets in a liquid ejection device. [Means for solving the problem]

[0007] In order to achieve the above object, one aspect of the present invention is a liquid ejection device that ejects liquid onto a substrate, and is characterized in that it comprises a head having a plurality of ejection holes that eject droplets, a holder that holds the head, and a cleaning mechanism that cleans the head held by the holder, wherein the holder is provided with a mark portion having a mark that is detected when measuring the relative position between the holder and the head, and the cleaning mechanism operates to clean the mark portion in addition to the head.

[0008] Further objects and other aspects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. [Effects of the Invention]

[0009] According to the present invention, for example, it is possible to provide an advantageous technique for maintaining the measurement accuracy of the position of a head that ejects liquid droplets in a liquid ejection device. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of the configuration of a liquid ejection device according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram showing an example of the configuration of a mark provided in the mark section; [Figure 3]A diagram showing an example of the holder configuration [Figure 4] FIG. 10 is a diagram illustrating a cleaning process performed by a cleaning mechanism. [Figure 5] A diagram showing an example of the configuration of the mark section [Figure 6] FIG. 10 is a diagram showing a modified example of the holder; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system, with the XY plane being a plane parallel to the surface on which the substrate is placed. The directions parallel to the X, Y, and Z axes in the XYZ coordinate system are the X direction, Y direction, and Z direction, respectively, and rotation around the X axis, rotation around the Y axis, and rotation around the Z axis are referred to as θX, θY, and θZ, respectively. Control and drive (movement) about the X axis, Y axis, and Z axis refer to control or drive (movement) in the direction parallel to the X axis, direction parallel to the Y axis, and direction parallel to the Z axis, respectively. Furthermore, control or drive about the θX axis, θY axis, and θZ axis refer to control or drive in the direction parallel to the X axis, rotation around the Y axis, and axis parallel to the Z axis, respectively.

[0013] First Embodiment The basic configuration and operation of a liquid ejection apparatus 100 according to a first embodiment of the present invention will be described. The liquid ejection apparatus 100 is an apparatus that ejects (supplies, applies) a liquid, which is a material for a functional element, onto a substrate to form a pattern, and functions as a substrate processing apparatus for processing substrates such as display panels and semiconductor wafers. For example, the liquid ejection apparatus 100 can be used to manufacture display devices such as flat panel displays and OLED (organic light emitting diode) devices. The liquid ejected onto a substrate by the liquid ejection apparatus 100 is sometimes called ink, and its components are not particularly limited. For example, a liquid containing a solute and a solvent for forming an organic film on the substrate can be used as the liquid. Hereinafter, the liquid ejected onto a substrate by the liquid ejection apparatus 100 may be simply referred to as "liquid."

[0014] 1 is a schematic diagram showing an example of the configuration of a liquid ejection apparatus 100 according to this embodiment. The liquid ejection apparatus 100 may include a substrate stage 2, a liquid ejection unit 10, a cleaning unit 20, and a control unit 30.

[0015] The substrate stage 2 holds the substrate 1 and is configured to be movable in the X and Y directions on a surface plate 3. In other words, the substrate stage 2 is configured as a drive mechanism below the discharge head 11 of the liquid discharge unit 10 (described later) that drives the substrate 1 relative to the discharge head 11. The substrate 1 may be a glass substrate, a plastic substrate, or the like, as appropriate, depending on the product to be manufactured. The substrate 1 is typically a plate-shaped member, but is not limited to a specific shape or form as long as it can function as a substrate. For example, the substrate 1 may be a deformable film or a circular (disk-shaped) substrate. The substrate 1 is also provided with a pixel region for applying a liquid to form an array of a large number of display pixels.

[0016] The liquid ejection unit 10 may include an ejection head 11 that ejects liquid, a holder 12 that holds the ejection head 11, a drive mechanism 13 that drives the holder 12, and a support 14 that supports the holder 12. The ejection head 11 has a plurality of ejection holes 11a on its surface (lower surface) that eject droplets of liquid stored in a tank (not shown). Each of the plurality of ejection holes 11a may be configured as a nozzle that ejects droplets. The holder 12 is a member to which the ejection head 11 is attached. The holder 12 may be equipped with multiple ejection heads 11, not just one. The drive mechanism 13 may be configured to drive the holder 12 in the Z direction, but may also be configured to drive the holder 12 in the X and Y directions. The support 14 supports the holder 12, which is disposed above the movement path of the substrate stage 2, so that the substrate stage 2 (substrate 1) can move below the holder 12 (ejection head 11). That is, the support pillar 14 supports the holder 12 at a position facing the upper surface of the substrate 1 (substrate stage 2 ) disposed below the discharge head 11 .

[0017] The cleaning unit 20 may include a cleaning mechanism 21 that cleans the ejection head 11 held by the holder 12, and a drive mechanism 22 that drives the cleaning mechanism 21. The cleaning mechanism 21 is a mechanism for removing dirt adhering to the underside of the ejection head 11 (i.e., the surface on which the plurality of ejection holes 11a are provided) to restore the ejection performance of the ejection head 11. The cleaning mechanism 21 of this embodiment may be configured to clean the underside of the ejection head 11 while moving below the ejection head 11 (i.e., to remove liquid adhering to the underside of the ejection head). The cleaning mechanism 21 may be configured to perform so-called wiping, which cleans the underside of the ejection head 11 by wiping the underside, but is not limited to this. The cleaning mechanism 21 may also be configured to clean the underside of the ejection head 11 by sucking the liquid adhering to the underside of the ejection head 11 or by blowing gas (air blow) onto the liquid adhering to the underside of the ejection head 11. The driving mechanism 22 can be configured to drive the cleaning mechanism 21 in the XY directions and the Z direction. The cleaning mechanism 21 and the driving mechanism 22 are supported by a support 23.

[0018] The control unit 30 is configured as a computer (information processing device) having a processor such as a CPU (Central Processing Unit) and a storage unit such as a memory, and controls each unit of the liquid ejection device 100 to control the ejection of liquid onto the substrate 1. The control unit 30 may be configured, for example, as a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), an ASIC (abbreviation for Application Specific Integrated Circuit), a general-purpose computer with an embedded program, or a combination of all or part of these. The control unit 30 also controls the cleaning process (cleaning operation) of the ejection head 11 by the cleaning mechanism 21 (cleaning unit 20).

[0019] Incidentally, in the liquid ejection device 100, for example, a position error (attachment error) may occur in the ejection head 11 attached to the holder 12 after replacement or maintenance of the ejection head 11. In this case, it may be difficult to accurately position droplets at desired positions on the substrate 1, so it is necessary to measure the relative position between the ejection head 11 and the holder 12 after replacement or maintenance of the ejection head 11. For this reason, in the liquid ejection device 100, a mark unit 40 having a mark 41 is provided on the underside of the holder 12, and the relative position between the ejection head 11 and the holder 12 is measured by detecting the mark 41 on the mark unit 40 using the detection unit 4.

[0020] The detection unit 4 is mounted on the substrate stage 2 and configured to be movable in the X and Y directions in accordance with movement of the substrate stage 2 in the X and Y directions. This allows the control unit 30 to cause the detection unit 4 to detect the position of the mark 41 in the mark section 40 and the position of the discharge hole 11a of the discharge head 11 via movement of the detection unit 4 in the X and Y directions, and to measure the relative position between the discharge head 11 and the holder 12 based on the detection results. In measuring the relative position between the discharge head 11 and the holder 12, the movement distance and movement direction of the detection unit 4 may also be used in addition to the detection results of the position of the mark 41 and the position of the discharge hole 11a by the detection unit 4. Furthermore, the detection unit 4 may be configured, for example, by a camera having an image sensor (photoelectric conversion element).

[0021] From the viewpoint of improving the measurement accuracy of the relative position between the ejection head 11 and the holder 12, it is preferable that the mark portion 40 be disposed near the ejection head 11. However, if the mark portion 40 is disposed near the ejection head 11, the liquid ejected from the ejection head 11 (each ejection hole 11a) may adhere to the mark portion 40, causing the mark portion 40 to become dirty. In this case, the detection unit 4 cannot accurately detect the mark 41 of the mark portion 40, and the measurement accuracy of the relative position between the ejection head 11 and the holder 12 may decrease. In other words, it may become difficult to maintain the measurement accuracy of the relative position between the ejection head 11 and the holder 12. Therefore, the cleaning mechanism 21 in the liquid ejection device 100 of this embodiment operates to clean the mark portion 40 in addition to the ejection head 11.

[0022] The control unit 30 is connected to the substrate stage 2, the discharge head 11, the drive mechanism 13, the drive mechanism 22, the detection unit 4, and sensors (not shown) in the liquid discharge device 100, and performs calculations and control necessary for controlling the liquid discharge device 100. Specifically, prior to the discharge of droplets by the discharge head 11, the control unit 30 calculates the position of the mark 41 and the position of the discharge head 11 (each discharge hole 11a) derived from the position of the mark 41 based on an image of the mark 41 acquired by the detection unit 4. The control unit 30 can also perform nozzle mapping to determine the discharge holes 11a to be used for printing and the timing of droplet discharge for each printing area on the substrate 1 based on the calculated position of the discharge head 11 (each discharge hole 11a) and pre-set printing cell information for the substrate 1. The printing cell information may be understood as position information for each pixel in a pixel region of the substrate 1 where a large number of pixels are to be arranged, and the printing area may be understood as each pixel (RGB) in the pixel region. Furthermore, the control unit 30 can cause the discharge head 11 to discharge droplets while moving the substrate stage 2 in the X and Y directions based on the nozzle mapping. Note that the control unit 30 may be divided into multiple control units to perform distributed processing.

[0023] FIG. 2 is a diagram showing an example of the configuration of a mark 41 provided on the mark unit 40. The mark unit 40 may include a mark base 42 (first member) having a surface on which the mark 41 is formed. FIG. 2(a) shows the mark base 42 on which a mark 41a is formed using a chrome film. FIG. 2(b) shows the mark base 42 on which a concave mark 41b is formed by etching or the like. FIG. 2(c) shows the mark base 42 on which a mark 41c as a perforation (through hole) is formed. In each of FIGS. 2(a) to 2(c), the upper diagram is a plan view of the mark base 42, and the lower diagram is a cross-sectional view of the mark base 42. Note that the material and shape of the mark 41 are merely examples, and may be determined taking into consideration the required accuracy, ease of detection, resistance to contamination, ease of contamination removal, processability, etc., and materials and shapes other than those shown in the drawings may also be used.

[0024] Fig. 3 is a diagram showing a basic configuration example of the holder 12. Fig. 3(a) is a bottom plan view of the holder 12 (a view of the holder 12 seen from below), and Fig. 3(b) is a side cross-sectional view taken along the line AA in Fig. 3(a).

[0025] The holder 12 holds at least one ejection head 11 and has at least one mark portion 40. In the example of FIG. 3, the holder 12 holds multiple ejection heads 11 and has multiple mark portions 40. The multiple ejection heads 11 can be arranged in a staggered pattern so that there are no gaps in the ejectable area when the substrate 1 is moved (scanned) in the Y direction relative to the holder 12. The ejectable area is an area on the substrate 1 to which droplets ejected from each ejection head 11 can be supplied (arranged). The multiple ejection heads 11 can be attached to the holder 12 so that their lower surfaces are approximately flush with each other.

[0026] The mark portion 40 may be disposed near the ejection head 11 on the underside of the holder 12. In the example of FIG. 3 , two mark portions 40 are provided on the underside of the holder 12. The two mark portions 40 may be disposed at both ends of the underside of the holder 12 in the X direction, sandwiching the multiple ejection heads 11 in the X direction. The two mark portions 40 may also be disposed so that their undersides are substantially flush with the undersides of the multiple ejection heads 11. However, if there is a possibility that droplets ejected from each ejection head 11 may reach the mark portion 40 by running along the underside of each ejection head 11 and the underside of the holder 12, the underside of the mark portion 40 and the underside of the ejection head 11 may be uneven. That is, the height of the underside of the mark portion 40 may be different from the height of the underside of the ejection head 11. Furthermore, to make it easier for the cleaning mechanism 21 to clean droplets adhering to the underside of the mark portion 40, it is desirable that the unevenness on the underside of the mark portion 40 be as small as possible.

[0027] Next, a description will be given of the cleaning process (cleaning operation) of the ejection head 11 and the mark portion 40 by the cleaning mechanism 21 of the cleaning unit 20. Fig. 4 is a diagram for explaining the cleaning process by the cleaning mechanism 21. Figs. 4(a) and 4(b) show the liquid ejection device 100 as viewed from the +X direction, and Fig. 4(c) shows the liquid ejection device 100 as viewed from the -Y direction.

[0028] When the control unit 30 receives an instruction to start the cleaning process via a user interface or the like, it drives the substrate stage 2 to retract the substrate stage 2 from below the holder 12, as shown in FIG. 4(a). Next, as shown in FIG. 4(b), the control unit 30 causes the driving mechanism 22 to move the cleaning mechanism 21 in the -Y direction, thereby sending (placing) the cleaning mechanism 21 below the holder 12. The sending position of the cleaning mechanism 21 can be determined based on coordinate information of each discharge head 11 and coordinate information of the mark unit 40. The coordinate information of each discharge head 11 includes, for example, information indicating the position of each discharge head 11 in the XY directions and information indicating the height of the lower surface of each discharge head 11 (position in the Z direction), and is acquired in advance and stored in a storage unit. Similarly, the coordinate information of the mark unit 40 includes information indicating the position of the mark unit 40 in the XY directions and information indicating the height of the lower surface of the mark unit 40 (position in the Z direction), and is acquired in advance and stored in a storage unit.

[0029] The cleaning process begins after the cleaning mechanism 21 is sent below the holder 12. As shown in FIG. 4(c), the control unit 30 causes the cleaning mechanism 21 to clean the lower surfaces of the ejection heads 11 and the mark unit 40 while changing the position of the cleaning mechanism 21 in the X direction using the drive mechanism 22. For example, the control unit 30 causes the cleaning mechanism 21 to clean the lower surfaces of the ejection heads 11 and the mark unit 40 while moving the cleaning mechanism 21 in the ±X directions below the holder 12 (each ejection head 11 and mark unit 40) using the drive mechanism 22. In this embodiment, the cleaning mechanism 21 is configured to wipe the lower surfaces of the ejection heads 11 and the mark unit 40. In this case, the control unit 30 causes the cleaning mechanism 21 to move in the ±X directions while keeping the cleaning mechanism 21 in contact with the lower surfaces of the ejection heads 11 and the mark unit 40 using the drive mechanism 22. This allows the lower surfaces of the ejection heads 11 and the mark unit 40 to be cleaned. When the cleaning process is completed, the control unit 30 causes the driving mechanism 22 to move the cleaning mechanism 21 in the +Y direction, and retracts the cleaning mechanism 21 from below the holder 12 (that is, to the state shown in FIG. 4(a)).

[0030] The cleaning process may include a head cleaning process (first process) and a mark cleaning process (second process). The head cleaning process is a process of moving the cleaning mechanism 21 below the ejection head 11 so as to clean the underside of the ejection head 11. The mark cleaning process is a process of moving the cleaning mechanism 21 below the mark portion 40 so as to clean the underside of the mark portion 40. The mark cleaning process may be performed before or after the head cleaning process.

[0031] The head cleaning process and the mark cleaning process may be performed separately. In this case, the control unit 30 performs the head cleaning process by moving the cleaning mechanism 21 below the ejection head 11 (for example, by moving it back and forth in the ±X directions), and then performs the mark cleaning process by moving the cleaning mechanism 21 below the mark unit 40 (for example, by moving it back and forth in the ±X directions). Alternatively, the control unit 30 performs the mark cleaning process by moving the cleaning mechanism 21 below the mark unit 40 (for example, by moving it back and forth in the ±X directions), and then performs the head cleaning process by moving the cleaning mechanism 21 below the ejection head 11 (for example, by moving it back and forth in the ±X directions).

[0032] When the holder 12 is provided with a plurality of ejection heads 11 arranged in the X direction, the control unit 30 may control the movement of the cleaning mechanism 21 in the head cleaning process so that the movement stroke of the cleaning mechanism 21 in the X direction includes the plurality of ejection heads 11. In this case, the plurality of ejection heads 11 are treated as a single structure, and the head cleaning process is performed on that structure. Alternatively, the control unit 30 may control the movement of the cleaning mechanism 21 in the head cleaning process so that the movement stroke of the cleaning mechanism 21 in the X direction includes one ejection head 11. In this case, the head cleaning process is performed individually for each of the plurality of ejection heads 11. Note that the movement stroke may be defined as the movement range of the cleaning mechanism 21 from when the cleaning mechanism 21 starts moving in one direction (e.g., the +X direction or the −X direction) until the cleaning mechanism 21 stops.

[0033] Furthermore, the head cleaning process and the mark cleaning process may be performed consecutively without stopping the movement of the cleaning mechanism 21 in the X direction. For example, assume that the mark unit 40 is disposed to the side of the ejection head 11 in the +X direction (first direction). In this case, while moving the cleaning mechanism 21 in the +X direction, the control unit 30 performs cleaning of the ejection head 11 (head cleaning process) and cleaning of the mark unit 40 (mark cleaning process) consecutively without stopping the movement of the cleaning mechanism 21. In other words, the movement stroke of the cleaning mechanism 21 in the X direction includes the ejection head 11 and the mark unit 40. In the case where multiple ejection heads 11 and multiple mark units 40 are arranged in the X direction, the movement stroke of the cleaning mechanism 21 in the X direction includes the multiple ejection heads 11 and the multiple mark units 40.

[0034] Here, the lower surface of the ejection head 11 and the lower surface of the mark portion 40 may have different heights (positions in the Z direction). In this case, the control unit 30 may adjust the height of the cleaning mechanism 21 using the drive mechanism 22 in accordance with the difference in height between the lower surface of the ejection head 11 and the lower surface of the mark portion 40 between the head cleaning process and the mark cleaning process. This difference can be determined based on coordinate information of the ejection head 11 and coordinate information of the mark portion 40.

[0035] As described above, the cleaning mechanism 21 in the liquid ejection device 100 of this embodiment operates to clean the mark portion 40 in addition to the ejection head 11. This allows the cleaning mechanism 21 to clean the mark portion 40 that has become soiled by the liquid ejected from the ejection head 11 (each ejection hole 11a). As a result, the detection unit 4 can accurately detect the mark 41 on the mark portion 40, thereby maintaining the measurement accuracy of the relative position between the ejection head 11 and the holder 12 (i.e., the position of the ejection head 11).

[0036] Second Embodiment A second embodiment of the present invention will be described. In the second embodiment, an example of the configuration of the mark section 40 will be described. Note that the second embodiment basically follows on from the first embodiment, and can follow the first embodiment except for the matters mentioned below. In other words, the configuration and operation of the liquid ejection device 100 other than the configuration of the mark section 40 are the same as those described in the first embodiment.

[0037] 5 is a diagram showing an example of the configuration of the marking unit 40. FIG. 5 shows a side cross-sectional view of the holder 12 having the ejection head 11 and the marking unit 40.

[0038] FIG. 5(a) shows a mark unit 40 of a first configuration example. The mark unit 40 of the first configuration example includes a mark base 42 (first member) having a first surface 42a on which a mark 41 is formed, and is disposed on the holder 12 so that the first surface 42a is the lower surface of the mark unit 40. That is, in the mark unit 40 of the first configuration example, the first surface 42a of the mark base 42 is the exposed surface (exposed surface) to be cleaned by the cleaning mechanism 21. Therefore, the mark base 42 does not need to be made of a light-transmitting material (substrate) and can be made of any material. Furthermore, the mark unit 40 of the first configuration example is preferably disposed on the holder 12 so that the first surface 42a of the mark base 42 is flush with the lower surface of the ejection head 11.

[0039] FIG. 5B shows a mark unit 40 according to a second exemplary configuration. The mark unit 40 according to the second exemplary configuration includes a mark base 42 having a first surface 42a on which a mark 41 is formed, and a transparent mark cover 43 (second member) that covers the first surface 42a of the mark base 42. The mark base 42 is disposed so that the first surface 42a faces downward, and the mark cover 43 covers the first surface 42a of the mark base 42 from below. The mark unit 40 according to the second exemplary configuration is disposed on the holder 12 so that the lower surface of the mark cover 43 is the lower surface of the mark unit 40. That is, in the mark unit 40 according to the second exemplary configuration, the lower surface of the mark cover 43 is an exposed surface (exposed surface) that can be cleaned by the cleaning mechanism 21. By providing the mark cover 43 in this manner, it is possible to prevent dirt from directly adhering to the mark 41 on the mark base 42.

[0040] In the mark unit 40 of the second configuration example, the detection unit 4 detects the mark 41 through the mark cover 43. Therefore, the mark cover 43 is made of a material that is translucent to (i.e., transparent to) light of a wavelength that can be detected by the detection unit 4. For example, when an infrared camera is used as the detection unit 4, the mark cover 43 can be made of a material that is translucent to infrared light, such as silicon (Si).

[0041] Furthermore, in order to make it easier to clean dirt from the mark cover 43, the mark unit 40 of the second configuration example is preferably arranged so that the lower surface of the mark cover 43 is substantially flush with the lower surface of the discharge head 11. In this case, unevenness (steps) on the lower surface of the holder 12 (mark unit 40) is reduced, making it less likely that liquid discharged from the discharge head 11 will accumulate as dirt on the lower surface of the mark unit 40. Furthermore, compared to the mark unit 40 of the first configuration example, liquid is less likely to get into gaps in the uneven parts around the periphery of the mark 41, making it possible to clean the mark unit 40 more easily and reliably without using a complex cleaning mechanism to deal with dirt in those gaps.

[0042] 5(c) shows a mark unit 40 of a third configuration example. The mark unit 40 of the third configuration example includes a mark base 42 having a first surface 42a on which a mark 41 is formed, and is disposed on the holder 12 so that a second surface 42b opposite the first surface 42a forms the underside of the mark unit 40. That is, in the mark unit 40 of the third configuration example, the second surface 42b of the mark base 42 is an exposed surface (exposed surface) that can be cleaned by the cleaning mechanism 21. With this configuration, the mark 41 is covered by the mark base 42 without using the mark cover 43 as in the mark unit 40 of the second configuration example, and therefore, it is possible to prevent dirt from directly adhering to the mark 41 on the mark base 42.

[0043] In the mark unit 40 of the third configuration example, the detection unit 4 detects the mark 41 through the mark base 42. Therefore, the mark base 42 is made of a material that is transmissive to light of a wavelength detectable by the detection unit 4 (i.e., transparent to the light). For example, when an infrared camera is used as the detection unit 4, the mark base 42 may be made of a material that is transmissive to infrared light, such as silicon (Si). Furthermore, in the mark unit 40 of the third configuration example, the second surface 42b of the mark base 42 is preferably arranged so that it is substantially flush with the bottom surface of the ejection head 11, making it easier to clean any dirt on the second surface 42b of the mark base 42. In this case, as with the mark unit 40 of the second configuration example, the unevenness (steps) on the bottom surface of the holder 12 (mark unit 40) is reduced, making it less likely that liquid ejected from the ejection head 11 will accumulate on the bottom surface of the mark unit 40 as dirt.

[0044] <Third embodiment> A third embodiment of the present invention will be described. In the third embodiment, a modified example regarding the arrangement of the multiple ejection heads 11 and the multiple mark units 40 in the holder 12 will be described. Note that the third embodiment basically inherits the first embodiment, and can follow the first embodiment except for the matters mentioned below. In other words, the configuration and operation of the liquid ejection device 100 other than the arrangement of the multiple ejection heads 11 and the multiple mark units 40 in the holder 12 are the same as those described in the first embodiment. Furthermore, the configuration of the mark unit 40 may be any of the first to third configuration examples described in the second embodiment.

[0045] 6A and 6B are diagrams showing modified examples of the arrangement of a plurality of ejection heads 11 and a plurality of marking portions 40 in the holder 12. Fig. 6A is a plan view of the underside of the holder 12 (a view of the holder 12 seen from below). Fig. 6B is a side cross-sectional view taken along the line BB in Fig. 6A.

[0046] In the present embodiment, the holder 12 is fitted with a plurality of ejection heads 11 arranged in the X direction, and a mark portion 40 is disposed between at least one pair of adjacent ejection heads 11 among the plurality of ejection heads 11. This configuration allows for more accurate measurement of the relative position between the holder 12 and each ejection head 11; however, the mark portion 40 is more likely to become soiled by the liquid ejected from each ejection head 11. Therefore, it is preferable to measure the relative position between the holder 12 and each ejection head 11 after a mark cleaning process is performed by the cleaning mechanism 21. Furthermore, the repeated ejection and pause of droplet ejection by each ejection head 11 may cause complex changes over time in the holder 12. In contrast, in the present embodiment, the position of each ejection head 11 (ejection holes 11a) can be measured with high accuracy by measuring the plurality of mark portions 40 (marks 41) provided on the holder 12.

[0047] <Embodiment of an article manufacturing method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as display panels for organic electroluminescence (EL) displays, microdevices such as semiconductor devices, and elements having fine structures. The article manufacturing method according to this embodiment includes a discharging step of discharging (supplying) a liquid onto a substrate using the liquid discharge device described above, a processing step of processing the substrate onto which the liquid has been discharged in the discharging step, and a step of manufacturing an article from the substrate processed in the processing step. Furthermore, this article manufacturing method includes other well-known processes (such as baking, cooling, cleaning, oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, and packaging). The article manufacturing method according to this embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost.

[0048] <Summary of the embodiment> The disclosure of the present specification includes at least the following liquid ejection device and article manufacturing method. (Item 1) A liquid ejection device that ejects liquid onto a substrate, a head having a plurality of ejection holes for ejecting droplets; a holder for holding the head; a cleaning mechanism that cleans the head held by the holder, the holder is provided with a mark portion having a mark that is detected when measuring the relative position between the holder and the head, The liquid ejection device, wherein the cleaning mechanism operates to clean the mark portion in addition to the head. (Item 2) the head has the plurality of ejection holes on a lower surface thereof, 2. The liquid ejection device according to item 1, wherein the cleaning mechanism cleans the lower surface of the head and the lower surface of the mark portion while moving below the head and the mark portion. (Item 3) Further, a control unit that controls the cleaning process by the cleaning mechanism is included. The liquid ejection device described in item 2, characterized in that the cleaning process includes a first process of moving the cleaning mechanism below the head so that the underside of the head is cleaned, and a second process of moving the cleaning mechanism below the mark portion after or before the first process so that the underside of the mark portion is cleaned. (Item 4) The liquid ejection device described in item 3 is characterized in that the control unit adjusts the height of the cleaning mechanism between the first process and the second process in accordance with the difference in height between the lower surface of the head and the lower surface of the mark section. (Item 5) the mark portion is disposed on a side of the head in a first direction, The liquid ejection device described in item 3 or 4, characterized in that the control unit performs the first process and the second process consecutively without stopping the movement of the cleaning mechanism while moving the cleaning mechanism in the first direction. (Item 6) A liquid ejection device described in any one of items 1 to 5, characterized in that the mark section includes a first member having a first surface on which the mark is formed, and the first surface is provided on the holder so that it can be cleaned by the cleaning mechanism. (Item 7) A liquid ejection device described in any one of items 1 to 5, characterized in that the mark section includes a first member having a first surface on which the mark is provided, and a second surface of the first member opposite the first surface is provided on the holder so that it can be cleaned by the cleaning mechanism. (Item 8) A liquid ejection device described in any one of items 1 to 5, characterized in that the mark section includes a first member having a first surface on which the mark is provided and a transparent second member covering the first surface, and the second member is provided on the holder so that it can be cleaned by the cleaning mechanism. (Item 9) The holder holds a plurality of the heads, The liquid ejection device described in any one of items 1 to 8, characterized in that the mark portion is arranged between at least one pair of two adjacent heads among the plurality of heads. (Item 10) a stage that holds the substrate and moves below the head; a detection unit that detects the mark of the mark portion, 10. The liquid ejection device according to any one of items 1 to 9, wherein the detection unit is provided on the stage. (Item 11) The liquid ejection device described in any one of items 1 to 10, characterized in that the cleaning mechanism cleans the head and the mark portion by wiping the surfaces of the head and the mark portion or by sucking up liquid adhering to the surfaces of the head and the mark portion. (Item 12) a discharge step of discharging a liquid onto a substrate using the liquid discharge device according to any one of items 1 to 11; a processing step of processing the substrate onto which the liquid has been discharged in the discharging step; a manufacturing process for manufacturing an article from the substrate processed in the processing process; A method for manufacturing an article, comprising:

[0049] The invention is not limited to the above-described embodiments, and various changes and modifications can be made 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]

[0050] 1: substrate, 2: substrate stage, 4: detection unit, 10: liquid ejection unit, 11: ejection head, 12: holder, 20: cleaning unit, 21: cleaning mechanism, 30: control unit, 40: mark unit, 41: mark, 42: mark base (first member), 43: mark cover (second member)

Claims

1. A liquid ejection device that ejects liquid onto a substrate, a head having a plurality of ejection holes for ejecting droplets; a holder for holding the head; a cleaning mechanism that cleans the head held by the holder, the holder is provided with a mark portion having a mark that is detected when measuring the relative position between the holder and the head, The liquid ejection device, wherein the cleaning mechanism operates to clean the mark portion in addition to the head.

2. the head has the plurality of ejection holes on a lower surface thereof, 2. The liquid ejection device according to claim 1, wherein the cleaning mechanism cleans the lower surface of the head and the lower surface of the mark portion while moving below the head and the mark portion.

3. Further, a control unit that controls the cleaning process by the cleaning mechanism is included. The liquid ejection device described in claim 2, characterized in that the cleaning process includes a first process of moving the cleaning mechanism below the head so that the underside of the head is cleaned, and a second process of moving the cleaning mechanism below the mark portion after or before the first process so that the underside of the mark portion is cleaned.

4. The liquid ejection device according to claim 3, wherein the control unit adjusts the height of the cleaning mechanism between the first process and the second process in accordance with the difference in height between the lower surface of the head and the lower surface of the mark portion.

5. the mark portion is disposed on a side of the head in a first direction, The liquid ejection device according to claim 3, wherein the control unit performs the first process and the second process consecutively without stopping the movement of the cleaning mechanism while the cleaning mechanism is moving in the first direction.

6. The liquid ejection device according to claim 1, wherein the mark portion includes a first member having a first surface on which the mark is formed, and the first surface is provided on the holder so that it can be cleaned by the cleaning mechanism.

7. The liquid ejection device described in claim 1, characterized in that the mark portion includes a first member having a first surface on which the mark is provided, and a second surface of the first member opposite the first surface is provided on the holder so that it can be cleaned by the cleaning mechanism.

8. The liquid ejection device described in claim 1, characterized in that the mark portion includes a first member having a first surface on which the mark is provided, and a transparent second member covering the first surface, and the second member is provided on the holder so that it can be cleaned by the cleaning mechanism.

9. The holder holds a plurality of the heads, The liquid ejection apparatus according to claim 1 , wherein the mark portion is disposed between at least one pair of two adjacent heads among the plurality of heads.

10. a stage that holds the substrate and moves below the head; a detection unit that detects the mark of the mark portion, The liquid ejection apparatus according to claim 1 , wherein the detection unit is provided on the stage.

11. 2. The liquid ejection device according to claim 1, wherein the cleaning mechanism cleans the head and the mark portion by wiping the surfaces of the head and the mark portion or by sucking up liquid adhering to the surfaces of the head and the mark portion.

12. a discharge step of discharging a liquid onto a substrate using the liquid discharge device according to any one of claims 1 to 11; a processing step of processing the substrate onto which the liquid has been discharged in the discharging step; a manufacturing process for manufacturing an article from the substrate processed in the processing process; A method for manufacturing an article, comprising:

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