Liquid application apparatus and method for manufacturing display panel

Abstract

The invention provides a liquid coating apparatus and a method of manufacturing a display panel. The liquid coating apparatus that coats a liquid on a substrate includes: an ejection unit that ejects liquid droplets toward the substrate; and a mist collection unit that collects mist generated by discharging the liquid droplets from the discharge unit, the mist collection unit including: a suction flow path that sucks the mist; and a liquid receiving section that receives liquid generated by aggregation of the mist, the suction flow path including: a suction port that sucks the mist; a discharge port for discharging the mist; an upward flow path extending upward toward the discharge port; and an inclined flow path extending obliquely upward from the suction port toward the upward flow path so as to merge with the upward flow path, the liquid receiving portion being disposed below the upward flow path.

Description

Technical Field

[0001] The present invention relates to a liquid coating device and a method for manufacturing a display panel. Background Art

[0002] In recent years, an inkjet method in which a material of a functional element is coated on a substrate using an inkjet device to form a target pattern has attracted attention. The inkjet method has advantages such as high material use efficiency because it can perform on-demand patterning, is beneficial for miniaturization of manufacturing devices because it is a non-vacuum process, and can coat a large-area substrate with liquid at high speed.

[0003] On the other hand, in the inkjet method, fog may be generated when ejecting droplets. Patent Document 1 describes a fog recovery unit having a fog trapping surface and a waste liquid holding unit. The air inhaled from the suction hole passes through the suction flow path divided by the separation wall and is ejected onto the fog trapping surface, and the fog contained in the air adheres to the fog trapping surface. The fog adhering to the fog trapping surface aggregates into a liquid, drips from the fog trapping surface, and is held by the waste liquid holding unit. However, in the fog recovery unit described in Patent Document 1, a part of the liquid formed by the fog adhering to the fog trapping surface may fall from the suction hole along the separation wall onto the substrate.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 6800614 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] The present invention provides a technique that is advantageous for more reliably recovering fog in a liquid coating device.

[0009] One aspect of the present invention relates to a liquid coating device that coats a substrate with a liquid. The coating device includes: an ejection unit that ejects droplets toward the substrate; and a fog collection unit that collects fog generated by ejecting droplets from the ejection unit. The fog collection unit includes: a suction flow path that sucks the fog; and a liquid receiving unit that receives a liquid generated by aggregation of the fog. The suction flow path includes: a suction port that sucks the fog; a discharge port that discharges the fog; an ascending flow path that extends upward toward the discharge port; and an inclined flow path that extends obliquely upward from the suction port toward the ascending flow path so as to merge with the ascending flow path. The liquid receiving unit is disposed below the ascending flow path. Brief Description of the Drawings

[0010] Figure 1 It is a diagram exemplarily showing the structure of the liquid coating device according to the first to third embodiments.

[0011] Figure 2 is a schematic perspective view showing the structure of the fog collection part of the first embodiment.

[0012] Figure 3 Schematically shows Figure 2 a cross-sectional view of the A-A section of

[0013] Figure 4 Schematically shows Figure 2 a cross-sectional view of the B-B section of

[0014] Figure 5 is a schematic cross-sectional view showing the structure of the fog collection part of the second embodiment.

[0015] Figure 6 is a schematic perspective view showing the structure of the fog collection part of the third embodiment.

[0016] Figure 7 Schematically shows Figure 6 a cross-sectional view of the A-A section of Detailed Embodiments

[0017] Hereinafter, the embodiments will be described in detail with reference to the drawings. In addition, the following embodiments do not limit the invention described in the claims. Although multiple features are described in the embodiments, not all of these multiple features are essential for the invention. In addition, the multiple features can be combined arbitrarily. Moreover, in the drawings, the same or identical structures are denoted by the same reference numerals, and redundant descriptions are omitted.

[0018] Refer to Figure 1 to describe the structure of the liquid coating device 1 of the first embodiment. In this specification and the drawings, as Figure 1 shown, the directions are represented in the XYZ coordinate system with the plane parallel to the plane on which the substrate 2 is disposed as the XY plane. The liquid coating device 1 is configured to coat a liquid on the substrate 2. The liquid coating device 1 can, for example, coat the liquid 4 on the substrate 2 by ejecting droplets composed of the liquid 4 (ink) which is a material for forming a functional element onto the substrate 2. Thereby, a pattern composed of the liquid 4 can be disposed on the substrate 2. The pattern composed of the liquid 4 coated on the substrate 2 can be converted into a solid film or pattern, for example, by drying and firing. The functional element is, for example, an OLED, and the liquid 4 is, for example, a material for forming any layer of the multiple organic layers of the OLED.

[0019] The liquid coating apparatus 1 can be provided with a transfer mechanism 3 that holds the substrate 2 and transfers (scans) the substrate 2 in a predetermined direction (scanning direction) (in this example, the Y direction) during the coating process of applying the liquid 4 to the substrate 2. The scanning direction of the substrate 2 based on the transfer mechanism 3 can be either only one direction (e.g., the +Y direction) or two directions (the +Y direction and the -Y direction). The transfer mechanism 3 can include, for example, a substrate stage having a substrate chuck that holds the substrate 2 and a drive mechanism that drives the substrate stage. The substrate 2 can be, for example, a glass substrate or a plastic substrate. The substrate 2 is typically a plate member. The shape of the substrate 2 is not limited to a specific shape and can be, for example, rectangular or circular. The substrate 2 can have, for example, a pixel array region 9 and one or more alignment marks 10. The pixel array region 9 can have a plurality of pixel regions. The liquid coating apparatus 1 can be configured to apply or dispose the liquid 4 in each pixel region. Each pixel region can be, for example, a region surrounded by a dam portion.

[0020] The liquid coating apparatus 1 can be provided with a discharge portion 5 that discharges droplets of the liquid 4 toward the substrate 2. The discharge portion 5 can have, for example, a plurality of discharge ports. In one example, the discharge portion 5 can include a plurality of discharge ports 5r, a plurality of discharge ports 5g, and a plurality of discharge ports 5b. The plurality of discharge ports 5r discharge the liquid 4 for forming an organic material of a light-emitting layer that generates light of a red wavelength. The plurality of discharge ports 5g discharge the liquid 4 for forming an organic material of a light-emitting layer that generates light of a green wavelength. The plurality of discharge ports 5b discharge the liquid 4 for forming an organic material of a light-emitting layer that generates light of a blue wavelength. In one example, the plurality of discharge ports 5r, the plurality of discharge ports 5g, and the plurality of discharge ports 5b can be respectively arranged to cover the width of the pixel array region 9 in the X direction orthogonal to the scanning direction. In one example, during one scan of the substrate 2 in the Y direction, the liquid coating apparatus 1 can apply the liquid 4 to all pixel regions of the pixel array region 9.

[0021] In addition to this, the liquid coating apparatus 1 can be provided with a control portion 6 and a mist collection portion 11. The liquid coating apparatus 1 can also be provided with a camera 7 and a height sensor 8. The control portion 6 can be constituted by, for example, 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 or dedicated computer embedded with a program, or a combination of all or a part of them.

[0022] The control unit 6 measures the positions of a plurality of alignment marks 10 using, for example, the camera 7, whereby the position and orientation of the substrate 2 can be detected. Further, the control unit 6 can control the conveyance mechanism 3 to relatively scan and drive the substrate 2 in the Y direction with respect to the ejection unit 5, and at the same time control the ejection unit 5 to apply the liquid 4 to each pixel region of the pixel array region 9 of the substrate 2 with necessary accuracy. The number of scans can be determined so as to apply a necessary amount of the liquid 4 to each pixel region. Further, in order to improve the accuracy of the application position of the liquid 4, the control unit 6 can measure the height of the substrate 2 using the height sensor 8 and adjust the distance between the ejection unit 5 and the substrate 2. The distance between the ejection unit 5 and the substrate 2 can be set to 0.5 mm or less, for example.

[0023] When droplets of the liquid 4 are ejected from the ejection unit 5, minute particles in the form of a mist that are not helpful for pixel formation, called fog, are generated. The fog can float in the space and adhere to various parts such as the ejection unit 5. This can cause poor ejection from the ejection unit 5, and may also cause a reduction in measurement accuracy due to adhesion to the camera 7 and the height sensor 8, or a reduction in the quality of the display panel due to adhesion to the substrate 2. Therefore, it is desirable to quickly recover the floating fog.

[0024] The fog generated from the ejection unit 5 can move in the scanning direction together with the substrate 2 as the substrate 2 is scanned and driven by the conveyance mechanism 3. Therefore, the liquid application device 1 can include a fog collection unit 11. The fog collection unit 11 can be disposed near the ejection unit 5. In one example, two sets of fog collection units 11 can be disposed so as to sandwich the ejection unit 5 in a direction parallel to the scanning direction of the substrate 2 by the conveyance mechanism 3. In this case, either only the fog collection unit 11 on the downstream side in the scanning direction can be operated, or both the fog collection unit 11 on the downstream side and the upstream side in the scanning direction can be operated. In another example, the fog collection unit 11 can be disposed on both sides of each of the ejection ports 5r, 5g, 5b. The ejection unit 5 and the fog collection unit 11 can be integrated. The conveyance mechanism 3, the ejection unit 5, the camera 7, and the height sensor 8 can be disposed in the internal space 408 of the chamber 12.

[0025] In the existing structure, there is sometimes a problem that the fog collected by the fog collection unit condenses and liquefies inside the fog collection unit and drips onto the substrate 2 to contaminate the substrate 2. In the liquid application device 1 of the first embodiment, a function for more reliably preventing such a problem from occurring is provided.

[0026] Figure 2 is a schematic perspective view showing the structure of the fog collection unit 11. Figure 3 is schematically showing Figure 2 a cross-sectional view taken along the line A-A of Figure 4 is schematically showing Figure 2Cross-sectional view of the B-B section. The fog collection unit 11 can include a suction flow path 320 that attracts the fog 306 and a liquid receiving unit 305 that receives the liquid generated by the condensation of the fog 306. The suction flow path 320 can include a suction port 301 that attracts the fog 306 and a discharge port 202 that discharges the fog 306. In addition, the suction flow path 320 can include an ascending flow path 309 that extends upward toward the discharge port 202, and an inclined flow path 302 that extends obliquely upward from the suction port 301 toward the ascending flow path 309 so as to merge with the ascending flow path 309. The liquid receiving unit 305 can be disposed below the ascending flow path 309.

[0027] The ascending flow path 309 can be defined by a plurality of walls including a first wall surface 308 that locally faces the inclined flow path 302. The fog 306 aggregates into a liquid at the first wall surface 308, and the liquid can move along the first wall surface 308 to the liquid receiving unit 305. The plurality of walls defining the ascending flow path 309 can have a second wall surface 313 facing the first wall surface 308, and the second wall surface 313 can be disposed above the liquid receiving unit 305. The second wall 313 can include a portion parallel to the first wall 308. The inclined surface 302a forming the upper surface of the inclined flow path 302 can be connected to the second wall surface 313. The connecting portion 323 of the inclined surface 302a and the second wall surface 313 can be disposed above the liquid receiving unit 305. The lower surface of the inclined flow path 302 can be formed by an inclined surface 302b. The inclined surface 302b can be either parallel or non-parallel to the inclined surface 302a.

[0028] On the inclined surface 302a, a recess 303 that is recessed in a direction away from the liquid receiving unit 305 can be provided. The recess 303 (the long side direction thereof) can extend in the horizontal direction (parallel to the X direction). At least a part of the recess 303 can be disposed above the liquid receiving unit 305. The first ridge line 321 forms the boundary (boundary line) between the recess 303 and the inclined surface 302a. The second ridge line 322 is located between the first ridge line 321 and the suction port 301 and forms another boundary (boundary line) between the recess 303 and the inclined surface 302a. At least the first ridge line 321 of the first ridge line 321 and the second ridge line 322 can be disposed above the liquid receiving unit 305. Preferably, both the first ridge line 321 and the second ridge line 322 are disposed above the liquid receiving unit 305. The liquid coating device 1 or the fog collection unit 11 can include a liquid recovery unit 330 that recovers the liquid (the liquid formed by the condensation of the fog 306) accumulated in the liquid receiving unit 305. The liquid recovery unit 330 can include a recovery pipe 304 having a plurality of holes 310 that attract the liquid accumulated in the liquid receiving unit 305.

[0029] The fog collection unit 11 can include: a first supply unit 333 including one or more first supply ports 311 that supply gas to the space between the substrate 2 (the space between the substrate 2 and the facing surface 314); and a second supply unit 331 including one or more second supply ports 312 that supply gas to this space. The first supply port 311 is arranged on one side of the substrate 2 in the scanning direction (specified direction) with respect to the suction port 301, and the second supply port 312 is arranged on the opposite side of the scanning direction with respect to the suction port 301.

[0030] The suction port 301 can be arranged to open on the facing surface 314 facing the substrate 2. For example, the suction port 301 can be arranged to face the substrate 2 held by the substrate stage of the transfer mechanism 3 such that the width in the short side direction (Y direction) is in the range of 1 mm to 10 mm and the width in the long side direction (X direction) is not less than the width of the pixel array region 9. The distance between the substrate 2 and the suction port 301 can be, for example, in the range of 0.1 mm to 5 mm. On the other hand, the distance between the substrate 2 and the facing surface 314 provided with the suction port 301 can be, for example, in the range of 0.1 mm to 5 mm. The distance between the substrate 2 and the suction port 301 (the distance between the substrate 2 and the facing surface 314) can be the same as the distance between the substrate 2 and the ejection part 5 (the lower surface thereof).

[0031] The suction flow path 320 communicates from the suction port 301 to the discharge port 202, and the gas containing fog 306 sucked from the suction port 301 is discharged through the discharge port 202. One end of the inclined flow path 302 can be the suction port 301. The angle θ between the direction (axial direction) of the inclined flow path 302 (or the inclined surfaces 302a, 302b) and the Z direction (the normal line of the upper surface of the substrate 2) is in the range of 20 to 70 degrees, preferably in the range of 30 to 60 degrees, more preferably in the range of 40 to 50 degrees, and can be, for example, 45 degrees. The angle θ can be determined according to the flow rate and velocity of the sucked gas, the arrangement space of the fog collection unit 11, etc.

[0032] The connection part of the inclined flow path 302 and the ascending flow path 309 constitutes a direction changing part that changes the direction of the sucked gas. The angle φ between the direction (axial direction) of the inclined flow path 302 and the direction (axial direction) of the ascending flow path 309 is equal to θ in this example and can be, for example, 45 degrees.

[0033] A part of the liquid receiving portion 305 can be constituted by the first wall surface 308. The liquid receiving portion 305 can be arranged to extend in the X direction. The diameter of the recovery pipe 304 of the liquid recovery portion 330 is, for example, in the range of 1 mm to 30 mm, the diameter of the plurality of holes 310 is, for example, in the range of 0.1 mm to several millimeters, and the pitch of the plurality of holes 310 is, for example, in the range of 1 mm to several tens of millimeters. The recovery pipe 304 can be connected to the decompression source 220 via the joint 204 and the recovery path 221. By decompressing the inside of the recovery pipe 304, the liquid accumulated in the liquid receiving portion 305 can be recovered through the plurality of holes 310. As the decompression source 220, an ejector or the like can be adopted. A gas-liquid separator for separating gas and liquid can also be arranged between the liquid receiving portion 305 and the decompression source 220. Instead of providing the recovery pipe 304, a discharge port can also be provided at the end of the liquid receiving portion 305.

[0034] The depth of the recess 303 (the distance between the bottom surface of the recess 303 and the inclined surface 302a) can be, for example, in the range of several millimeters to 20 mm. The width of the recess 303 (the distance between the first ridge line 321 and the second ridge line 322) can be, for example, in the range of several millimeters to 20 mm.

[0035] The first supply port 311 and the second supply port 312 can be arranged to open on the facing surface 314. The first supply port 311 and the second supply port 312 are arranged facing the substrate 2 such that the width in the short side direction (Y direction) is in the range of 1 mm to 10 mm and the width in the long side direction (X direction) is greater than the width of the pixel array region 9. The distance between the substrate 2 and the first supply port 311 and the second supply port 312 can be, for example, in the range of 0.1 mm to 5 mm. The distance between the substrate 2 and the first supply port 311 and the second supply port 312 can be the same as the distance between the substrate 2 and the ejection portion 5 (the lower surface thereof).

[0036] In addition to the first supply port 311, the first supply portion 333 can further include a first supply flow path 403, a first introduction portion 203, and a first pressurization source 213. The first supply port 311 communicates with the first introduction portion 203 through the first supply flow path 403, and the first introduction portion 203 is connected to the pressurization source 213. The pressurization source 213 can include, for example, a pressure generation portion, a pressure regulator, and a flow rate adjustment valve. In addition to including the second supply port 312, the second supply portion 331 can further include a second introduction portion 201 and a second pressurization source 211. The second supply port 312 communicates with the second introduction portion 201, and the second introduction portion 201 is connected to the pressurization source 211. The pressurization source 211 can include, for example, a pressure generation portion, a pressure regulator, and a flow rate adjustment valve.

[0037] The first pressurizing source 213 and the second pressurizing source 211 can be controlled by the control unit 6 so that the flow rate of the gas supplied from the first supply port 311 is faster than the flow rate of the gas supplied from the second supply port 312. In one example, the flow rate of the gas supplied from the first supply port 311 can be about several m / s, and the flow rate of the gas supplied from the second supply port 312 can be 1 m / s or less. In one example, the widths (Y direction) of the first supply port 311 and the second supply port 312 are 5 mm or less.

[0038] The discharge port 202 is connected to the decompression source 212. The decompression source 212 can include, for example, an ejector. A gas-liquid separator and / or a flow meter for separating gas and liquid may be disposed between the discharge port 202 and the decompression source 212. The liquid coating device 1 can include a plurality of discharge ports 202. The first and second pressurizing sources 213, 211 can pressurize the gas to several atmospheres or more, while the decompression source 212 can only decompress to minus 1 atmosphere (relative pressure). Therefore, the number of discharge ports 202 can be more than the number of the first introduction part 203 and the number of the second introduction part 201. The discharge amount of the gas from the discharge port 202 can be adjusted to be more than the supply amount of the gas to the first introduction part 203 and the second introduction part 201.

[0039] In order to form an organic layer in each pixel region of the pixel array region 9 of the substrate 2, while the transfer mechanism 3 scans and drives the substrate 2 in the +Y direction, a liquid as a material of the organic layer can be ejected from the ejection part 5 and coated on the pixel array region 9 of the substrate 2. At this time, a mist 306 that does not contribute to the formation of the organic layer is generated. The mist 306 can move downstream (+Y direction) from the space below the ejection part 5 as the substrate 2 moves.

[0040] The gas supplied from the first supply port 311 of the mist collection part 11 collides with the substrate 2 to form an air flow toward the suction port 301 on the upstream side. Therefore, the mist 306 that moves from the ejection part 5 to the first supply port 311 is transported to the suction port 301 by the air flow. In addition, the gas supplied from the second supply port 312 flows along the opposing surface 314 of the mist collection part 11 and is attracted by the suction port 301. At this time, the mist 306 is clamped by the gas supplied from the first supply port 311 and the gas supplied from the second supply port 312 and guided into the suction port 301. Therefore, the situation where the mist 306 adheres to the inclined surfaces 302a, 302b can be reduced.

[0041] The gas attracted through the inclined flow path 302 defined by the inclined surfaces 302a and 302b changes its traveling direction when flowing into the upflow path 309 and is discharged from the discharge port 202. At this time, a part of the mist 306 collides with the first wall surface 308 defining the upflow path 309 and adheres to the first wall surface 308. When the mist 306 adhering to the first wall surface 308 increases, they aggregate and liquefy, and the liquid moves along the first wall surface 308 to the liquid receiving portion 305.

[0042] The larger the angle φ, the easier it is for the mist 306 to collide with the first wall surface 308. This means that the amount of the mist 306 discharged through the discharge port 202 decreases. The angles θ and φ can be determined in consideration of the size of the mist collection portion 11, ease of manufacture, the amount of the mist 306, and the like.

[0043] The mist 306 may also adhere to the second wall surface 313 on the opposite side of the first wall surface 308. In this case, the liquid generated by the aggregation (liquefaction) of the mist 306 moves downward along the second wall surface 313, then drops into the liquid receiving portion 305 and accumulates in the liquid receiving portion 305. The liquid stored in the liquid receiving portion 305 is recovered by the liquid recovery portion 330. More specifically, the liquid stored in the liquid receiving portion 305 is attracted into the recovery pipe 304 through the hole 310 of the recovery pipe 304, and is attracted (recovered) to the decompression source 220 via the joint 204 and the recovery path 221. The control unit 6 can control the recovery of the liquid stored in the liquid receiving portion 305 by controlling the decompression source 220.

[0044] A part of the liquid moving downward along the second wall surface 313 may move beyond the connecting portion 323 and move toward the inclined surface 302a. However, such liquid is caught by the recess 303 (or the first ridge line 321) provided on the inclined surface 302a and drops into the liquid receiving portion 305.

[0045] The control unit 6 can control the decompression source 220 (liquid recovery portion 330) to recover the liquid stored in the liquid receiving portion 305 when the mist collection portion 11 does not collect mist, for example, when replacing the substrate 2. Here, when the liquid is recovered by the liquid recovery portion 330, the gas can be attracted together with the liquid through the hole 310. In this case, the flow of the gas attracted through the inclined flow path 302 is disturbed, whereby the mist 306 can adhere to the inclined surfaces 302a and 302b and aggregate to generate liquid. The liquid generated on the inclined surfaces 302a and 302b due to aggregation may move downward along the inclined surfaces 302a and 302b and drop from the suction port 301. Therefore, as described above, the control unit 6 can control the decompression source 220 (liquid recovery portion 330) to recover the liquid stored in the liquid receiving portion 305 when the mist collection portion 11 does not collect mist, for example, when replacing the substrate 2.

[0046] As described above, according to the first embodiment, the gas containing the mist 306 sucked through the suction port 301 can change its direction and flow into the ascending flow path 309 after passing through the inclined flow path 302, and is discharged through the discharge port 202. Here, when the gas passing through the inclined flow path 302 changes its direction and flows into the ascending flow path 309, the mist 306 collides with the first wall surface 308 and condenses, and the resulting liquid can be collected by the liquid receiving portion 305.

[0047] Hereinafter, with reference to Figure 5 the liquid coating apparatus 1 of the second embodiment will be described. Figure 5 is a cross-sectional view taken along line A-A schematically showing Figure 2 . Matters not mentioned in the description of the second embodiment can be in accordance with the description of the first embodiment. In the first embodiment, when the flow rate of the gas supplied to at least one of the first introduction portion 203 and the second introduction portion 201 increases or decreases, the pressure in the space between the substrate 2 and the facing surface 314 increases or decreases accordingly. Further, in the first embodiment, when the flow rate of the gas discharged from the discharge port 202 increases or decreases, the pressure in the space between the substrate 2 and the facing surface 314 decreases or increases accordingly. When the space between the substrate 2 and the facing surface 314 changes, the ejection of droplets from the ejection portion 5 may become unstable or the amount of mist generated may increase. The second embodiment is advantageous for stabilizing the ejection of droplets from the ejection portion 5 and / or reducing the amount of mist generated.

[0048] The distance h1 between the substrate 2 and the facing surface 314 is greater than the distance h2 between the substrate 2 and the ejection portion 5 (the surface provided with the ejection ports 5r, 5g, 5b). In one example, h1 is 1 mm or more and h2 is 0.5 mm or less.

[0049] In the second embodiment, the second introduction portion 201 communicates with Figure 1 the internal space 408 of the chamber 12 of the liquid coating apparatus 1 illustrated. The internal space 408 can be maintained at a reference pressure by an environmental control device (not shown). The width of the short side of the second supply port 312 can be in the range of 1 to 10 mm. The second supply port 312 is connected to the second gas flow path 401, and the length L (Z direction) of the second gas flow path 401 can be 50 mm or less. The second supply port 312 can be configured to discharge gas from the second supply port 312 in a direction along the surface of the substrate 2. The second supply portion 331 can have, for example, a rectifying portion (R-shaped portion) 402 that rectifies the flow of the gas so that the gas is discharged from the second supply port 312 in a direction along the surface of the substrate 2.

[0050] The first supply flow path 403 that connects the first supply port 311 and the first introduction part 203 can include one or more constriction parts 405a, 405b and one or more non-constriction parts 404a, 404b. The minimum width (in the Y direction) of the constriction parts 405a, 405b can be 0.5 mm or less. The minimum width (in the Y direction) of the non-constriction parts 404a, 404b can be several mm. The first supply part 333 (the first supply flow path 403) can include an expansion part 407 whose cross-sectional area increases as it goes toward the first supply port 311.

[0051] The mist collection part 11 can include a convex part 410 that protrudes toward the substrate 2 so as to form at least a part of a wall part that surrounds the space facing the facing surface 314. The distance between the substrate 2 and the convex part 410 can be h2. In other words, the distance between the substrate 2 and the convex part 410 can be the same as the distance between the substrate 2 and the ejection part 5.

[0052] The suction port 301 is connected to a decompression source 212 that generates a pressure lower than a reference pressure (here, the pressure in the internal space 408 of the chamber 12). In addition, the first supply port 311 is connected to a pressurization source 213 that generates a pressure higher than the reference pressure, and the second supply port 312 communicates with the internal space 408 that is a space having the reference pressure. The decompression source 212 and the pressurization source 213 can be configured, adjusted, or controlled such that the flow rate Q1 of the gas sucked by the suction port 301 is larger than the flow rate Q2 of the gas supplied from the first supply port 311. The control of the decompression source 212 and the pressurization source 213 can be performed by the control part 6, for example. The flow rate Q3 of the gas introduced into the second introduction part 201 is the difference between Q2 and Q1. That is, Q3 = Q2 - Q1. In one example, the width (in the Y direction) and the length L (in the Z direction) of the second gas flow path 401 can be determined such that the pressure loss generated in the second gas flow path 401 when the gas flows through the second gas flow path 401 at the flow rate Q3 is 50 Pa or less.

[0053] Since the second supply port 312 communicates with the internal space 408 of the chamber 12, the pressure in the space between the substrate 2 and the facing surface 314 (the mist collection part 11) is substantially equal to the pressure in the internal space 408. The difference between the pressure in the space between the substrate 2 and the facing surface 314 (the mist collection part 11) and the pressure in the internal space 408 can be 50 Pa or less as described above.

[0054] When the flow rate Q1 of the gas from the discharge port 202 and the flow rate Q2 of the gas supplied to the first supply port 311 (first introduction part 203) change (let the change amounts be dQ1 and dQ2 respectively), the flow rate Q3 of the gas introduced into the second introduction part 201 also changes. If the change in the flow rate Q3 is set as dQ3 (=dQ2 - dQ1), the change amount dQ3 is small relative to the flow rate Q3. Therefore, the pressure change in the space between the substrate 2 and the facing surface 314 (mist collection part 11) is also small and can be, for example, about several Pa.

[0055] The pressure change in the space between the substrate 2 and the ejection part 5 affects the ejection performance of the ejection part 5. However, in the second embodiment, even if Q1 and / or Q2 change unexpectedly, the pressure change in the space between the substrate 2 and the facing surface 314, and as a result, the pressure change in the space between the substrate 2 and the ejection part 5 and the substrate 2 is small. Therefore, the second embodiment is advantageous for stabilizing the ejection of the liquid from the ejection part 5, thereby reducing the generation of mist.

[0056] The air flow supplied to the second introduction part 201 is rectified in the direction along the surface of the substrate 2 by the rectifying part 402 of the second supply port 312 and is supplied to the space below the facing surface 314 of the mist collection part 11. Therefore, the mist 306 is not ejected onto the substrate 2. Thereby, the contamination of the substrate 2 can be reduced. In addition, since the gas supplied from the second supply port 312 flows along the facing surface 314 of the mist collection part 11, the situation where the mist 306 adheres to and accumulates on the facing surface 314 can be reduced. In addition, since the distance h1 between the substrate 2 and the facing surface 314 is larger than the distance h2 between the substrate 2 and the ejection part 5, the flow of the gas supplied from the second supply port 312 can be suppressed from disturbing the trajectory of the mist 306 and causing the mist 306 to adhere to the facing surface 314.

[0057] The gas introduced into the first introduction part 203 is sent to the first supply port 311 via the first supply flow path 403. Since the pressure loss of the narrow part 405a of the first supply flow path 403 is large, the gas flowing through the first supply flow path 403 expands in the X direction on the non-narrow part 404a on the upstream side of the narrow part 405a and then flows into the narrow part 405a. Similarly, the gas expands in the X direction on the non-narrow part 404b and then flows into the narrow part 405b. Therefore, the gas supplied from the first supply port 311 has a substantially uniform flow velocity in the X direction.

[0058] The expanding part 407 whose cross-sectional area increases as it goes to the first supply port 311 can smoothly expand the gas passing through the narrow part 405b in the Y direction and blow out the gas from the first supply port 311 at a desired flow velocity. In one example, the width of the first supply port 311 can be in the range of 1 mm to 5 mm, and the flow velocity of the gas blown out from the first supply port 311 can be in the range of 1 m / s to 5 m / s.

[0059] Since the distance h2 between the substrate 2 and the convex portion 410 is smaller than the distance h1 between the substrate 2 and the suction port 301, almost all of the gas supplied from the first supply port 311 does not leak out from under the convex portion 410 to the outside of the mist collection unit 11 and flows toward the suction port 301. Therefore, the mist 306 can be effectively recovered.

[0060] As described above, according to the second embodiment, since the second gas flow path 401 communicates with the internal space 408 of the chamber 12 of the liquid coating device 1, the pressure fluctuation in the space between the substrate 2 and the ejection unit 5 is reduced. As a result, the ejection of the droplets from the ejection unit 5 can be stabilized, and the generation of mist can be reduced. In addition, the gas supplied from the second supply port 312 does not disturb the trajectory of the mist 306, so the situation where the mist adheres to the facing surface 314 of the substrate 2 and the mist collection unit 11 can be reduced. In addition, since the first supply flow path 403 has the narrow portions 405a and 405b and the non-narrow portions 404a and 404b, the gas can be supplied at a substantially uniform and desired flow rate in the X direction (non-scanning direction). In addition, by providing the convex portion 410, most of the gas supplied from the first supply port 311 flows toward the suction port 301, so the mist 306 can be efficiently collected.

[0061] Hereinafter, with reference to Figure 6 、 Figure 7 the liquid coating device 1 of the third embodiment will be described. Matters not mentioned in the description of the third embodiment can be described according to the description of the first or second embodiment. In the third embodiment, Figure 7 is a cross-sectional view schematically showing the Figure 6 A-A section.

[0062] As described above, the liquid (ink) collected by the mist collection unit 11 is held by the liquid receiving unit 305 and recovered by the liquid recovery unit 330. However, when a liquid with a fast drying speed is used, the liquid may dry and solidify in the liquid receiving unit 305. Especially when the liquid recovery unit 330 includes a recovery pipe 304 having a plurality of holes 310, the holes 310 may be blocked by the solidified material and the liquid cannot be recovered. Therefore, the liquid coating device 1 of the third embodiment includes a cleaning unit 520 for cleaning the liquid recovery unit 330 (and the liquid receiving unit 305).

[0063] As Figure 6As illustrated, the cleaning unit 520 can include, for example, a cleaning liquid supply port 501 provided on the side wall 205 of the liquid receiving unit 305. The cleaning liquid supply port 501 communicates with the liquid receiving unit 305. The cleaning unit 520 can also include a cleaning liquid supply source 511 and a cleaning liquid flow path 512 connecting the cleaning liquid supply source 511 and the cleaning liquid supply port 501. In the cleaning process, the control unit 6 controls the cleaning liquid supply source 511 to supply a predetermined amount of cleaning liquid 502 to the liquid receiving unit 305.

[0064] When the liquid receiving unit 305 is filled with the cleaning liquid 502, the material (ink) held in the liquid receiving unit 305 dissolves in the cleaning liquid 502. In particular, when the hole 310 of the recovery pipe 304 of the liquid recovery unit 330 is immersed in the cleaning liquid 502, the material attached to and solidified on the hole 310 can be dissolved and removed from the hole 310. Then, the cleaning liquid 502 can be recovered by the liquid recovery unit 330.

[0065] The cleaning of the liquid recovery unit 330 can be performed according to the drying speed of the liquid (ink). For liquids with slow drying, the cleaning process can be performed several times a day, for example. On the contrary, for liquids with fast drying, the cleaning process can be performed, for example, each time a substrate is processed.

[0066] The method of recovering the liquid (ink) in the liquid recovery unit 330 and the method of supplying the cleaning liquid based on the cleaning unit 520 are not limited to a specific form. For example, the cleaning liquid 502 can always fill the liquid receiving unit 305 so that the hole 310 of the recovery pipe 304 is always immersed in the cleaning liquid 502. In this case, when the droplets collected by the mist collection unit 11 fall into the liquid receiving unit 305, they can immediately dissolve in the cleaning liquid 502. Therefore, unlike the above-described cleaning method, no additional time is required for the liquid (ink) solidified in the liquid receiving unit 305 to dissolve in the cleaning liquid 502, and the cleaning time can be shortened. In this case, when the cleaning process is started, the control unit 6 operates the decompression source to recover the liquid (ink) and the cleaning liquid 502 stored in the liquid receiving unit 305. Then, the control unit 6 operates the cleaning liquid supply source 511 to supply the cleaning liquid 502 to the liquid receiving unit 305 until the hole 310 of the recovery pipe 304 is immersed. As a result, even after the cleaning process is completed, the amount of the cleaning liquid 502 in the liquid receiving unit 305 remains constant.

[0067] In addition, as another method of always filling the liquid receiving unit 305 with the cleaning liquid 502, a circulation system can be configured in which the cleaning liquid supply port 501 always supplies the cleaning liquid 502 to the liquid receiving unit 305, while the liquid recovery unit 330 recovers the same amount of cleaning liquid 502 as the supply from the liquid receiving unit 305.

[0068] The liquid applied by the liquid application device 1 to the substrate 2 may also be, for example, a liquid containing a curable composition. The curable composition can be cured by being given curing energy such as light energy or heat energy. Such a liquid application device 1 can be assembled, for example, in a film forming device such as an imprint device or a planarization device, or can be used as a pretreatment device for a film forming device.

[0069] Hereinafter, an article manufacturing method for manufacturing an article using the liquid application device 1 will be described. The article manufacturing method can include: a coating step of coating a liquid material on a substrate using the liquid application device; a film forming step of treating the liquid material on the substrate to form a film; and a processing step of processing the substrate that has undergone the film forming step to obtain an article. In particular, an article manufacturing method for manufacturing a display panel as an article can include: a coating step of coating a liquid organic material on a substrate through the liquid application device; and a film forming step of drying and firing the liquid organic material on the substrate to form an organic material film. In addition, the article manufacturing method for manufacturing a display panel can include a processing step of processing the substrate that has undergone the film forming step to obtain a display panel.

[0070] Explanation of reference numerals

[0071] 1: Liquid application device; 2: Substrate; 3: Conveying mechanism; 4: Liquid; 5: Ejection part; 11: Mist collection part; 202: Discharge port; 301: Suction port; 306: Mist; 304: Recovery pipe; 305: Liquid receiving part; 302: Inclined flow path; 309: Upward flow path; 320: Suction flow path.

Claims

1. A liquid coating device for coating a substrate with a liquid, characterized in that: The liquid coating device includes: A spraying part that sprays droplets toward the substrate; And A mist collection part that collects the mist generated by spraying droplets from the spraying part, The mist collection part includes: a suction flow path that sucks the mist; and a liquid receiving part that receives the liquid generated by the condensation of the mist, The suction flow path includes: a suction port that sucks the mist; a discharge port that discharges the mist; an ascending flow path that extends upward toward the discharge port; and an inclined flow path that extends obliquely upward from the suction port toward the ascending flow path so as to merge with the ascending flow path, The liquid receiving part is disposed below the ascending flow path.

2. The liquid coating device according to claim 1, characterized in that: The ascending flow path is defined by a plurality of wall surfaces including a first wall surface that partially faces the inclined flow path.

3. The liquid coating device according to claim 2, characterized in that: The mist condenses on the first wall surface and moves along the first wall surface toward the liquid receiving part.

4. The liquid coating device according to claim 3, characterized in that: The plurality of wall surfaces have a second wall surface facing the first wall surface, and the second wall surface is disposed above the liquid receiving part.

5. The liquid coating device according to claim 4, characterized in that: The second wall surface includes a portion parallel to the first wall surface.

6. The liquid coating device according to claim 4, characterized in that: The inclined surface forming the upper surface of the inclined flow path is connected to the second wall surface, The connection portion of the inclined surface and the second wall surface is disposed above the liquid receiving part.

7. The liquid coating device according to claim 6, characterized in that: A concave portion recessed in a direction away from the liquid receiving part is provided on the inclined surface, The concave portion extends in the horizontal direction, and at least a part of the concave portion is disposed above the liquid receiving part.

8. The liquid coating device according to claim 7, characterized in that: At least the first ridge line forming the boundary between the concave portion and the inclined surface and the second ridge line located between the first ridge line and the suction port and forming the other boundary between the concave portion and the inclined surface are disposed above the liquid receiving part.

9. The liquid coating device according to claim 8, characterized in that: Both the first ridge line and the second ridge line are disposed above the liquid receiving part.

10. The liquid coating device according to claim 1, characterized in that: The liquid coating device further includes a liquid recovery part for recovering the liquid accumulated in the liquid receiving part.

11. The liquid coating device according to claim 10, characterized in that: The liquid recovery part includes a recovery pipe having a plurality of holes for sucking the liquid accumulated in the liquid receiving part.

12. The liquid coating device according to claim 10, characterized in that: The liquid coating device further includes a cleaning part for cleaning the liquid recovery part.

13. The liquid coating device according to claim 1, characterized in that: The liquid coating device further includes: a transfer mechanism that transfers the substrate in a specified direction during a coating process of coating the liquid on the substrate; a first supply unit including a first supply port that supplies gas to the space above the substrate; and a second supply unit including a second supply port that supplies gas to the space, wherein the first supply port is disposed on one side in the specified direction with respect to the suction port, and the second supply port is disposed on the opposite side in the specified direction with respect to the suction port.

14. The liquid coating device according to claim 13, wherein the suction port is connected to a decompression source that generates a pressure lower than a reference pressure, the first supply port is connected to a pressurization source that generates a pressure higher than the reference pressure, and the second supply port communicates with a space having the reference pressure.

15. The liquid coating device according to claim 14, wherein the flow rate of the gas sucked by the suction port is larger than the flow rate of the gas supplied from the first supply port.

16. The liquid coating device according to claim 14, wherein the second supply port is configured to discharge gas from the second supply port in a direction along the surface of the substrate.

17. The liquid coating device according to claim 14, wherein the first supply unit includes an expanding portion whose cross-sectional area increases as it goes toward the first supply port.

18. The liquid coating device according to claim 14, wherein the first supply unit includes a narrow portion and a non-narrow portion.

19. The liquid coating device according to claim 1, wherein the suction port opens on a facing surface facing the substrate, the mist collection unit includes a convex portion that protrudes toward the substrate so as to form at least a part of a wall portion surrounding the space faced by the facing surface.

20. A method for manufacturing a display panel, wherein the method for manufacturing the display panel includes: a coating step of coating a liquid organic material on a substrate by the liquid coating device according to any one of claims 1 to 19; a film forming step of drying and firing the liquid organic material on the substrate to form an organic material film; and a processing step of processing the substrate that has undergone the film forming step to obtain the display panel.

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