Liquid coating apparatus and manufacturing method of display panel

Abstract

To provide a technique advantageous for more reliably recovering mist in a liquid coating apparatus.SOLUTION: A liquid coating apparatus for coating a substrate with liquid, comprises: a discharge unit configured to discharge droplets toward the substrate; and a mist collection unit configured to collect mist generated by discharge of the droplets from the discharge unit. The mist collection unit includes a suction flow path configured to suck the mist, and a liquid receiving unit configured to receive liquid generated by aggregation of the mist. The suction flow path includes a suction port configured to suck the mist, a discharge port configured to discharge the mist, an ascending flow path extending upward toward the discharge port, and an inclined flow path extending 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.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] In recent years, the inkjet method, which uses an inkjet device to apply functional element materials to a substrate to form a desired pattern, has been attracting attention. The inkjet method has several advantages, including high material usage efficiency due to the ability to perform on-demand patterning, the advantage of being a non-vacuum process that allows for the miniaturization of manufacturing equipment, and the ability to apply liquid to large-area substrates at high speed.

[0003] On the other hand, with inkjet printing, mist can be generated when droplets are ejected. Patent Document 1 describes a mist collection unit having a mist trap surface and a waste liquid holding section. Air drawn in through a suction hole passes through a suction flow path defined by a separation wall and is blown onto the mist trap surface, where mist contained in the air adheres to the mist trap surface. The mist adhering to the mist trap surface collects and becomes liquid, drips from the mist trap surface, and is held in the waste liquid holding section. However, with the mist collection unit described in Patent Document 1, some of the liquid formed by the mist adhering to the mist trap surface can drip down the separation wall from the suction hole onto the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6800614 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an advantageous technique for more reliably collecting mist in a liquid application device. [Means for solving the problem]

[0006] One aspect of the present invention relates to a liquid application device that applies liquid to a substrate, the liquid application device comprising: a discharge section that discharges droplets toward the substrate; and a mist collection section that collects mist generated by the discharge of droplets from the discharge section; the mist collection section includes a suction flow path that sucks in the mist; and a liquid receiving section that receives liquid generated by the condensation of the mist; the suction flow path includes a suction port that sucks in the mist, a discharge port that discharges the mist, an upward flow path extending upward toward the discharge port, and an inclined flow path that extends diagonally upward from the suction port toward the upward flow path so as to merge with the upward flow path; and the liquid receiving section is arranged below the upward flow path. [Effects of the Invention]

[0007] According to the present invention, an advantageous technique for more reliably collecting mist in a liquid application device is provided. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a liquid application apparatus according to first to third embodiments. [Figure 2] FIG. 2 is a schematic perspective view showing the configuration of a mist collecting portion of the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view schematically showing the AA cross section of FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view schematically showing the cross section BB in FIG. 2. [Figure 5] FIG. 10 is a schematic cross-sectional view showing the configuration of a mist collecting portion of a second embodiment. [Figure 6] FIG. 10 is a schematic perspective view showing the configuration of a mist collecting portion according to a third embodiment. [Figure 7] FIG. 7 is a cross-sectional view schematically showing the AA cross section of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0009] 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.

[0010] The configuration of a liquid application apparatus 1 of a first embodiment will be described with reference to FIG. 1. 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 2 is placed, as shown in FIG. 1. The liquid application apparatus 1 is configured as an apparatus for applying a liquid to the substrate 2. The liquid application apparatus 1 can apply the liquid 4 to the substrate 2, for example, by ejecting droplets of the liquid 4 (ink) as a material for forming a functional element onto the substrate 2. This can result in a pattern made of the liquid 4 being arranged on the substrate 2. The pattern made of the liquid 4 applied to the substrate 2 can be converted into a solid film or pattern by, for example, drying and baking. The functional element is, for example, an OLED, and the liquid 4 is, for example, a material for forming one of the multiple organic layers of the OLED.

[0011] The liquid application apparatus 1 may include a transport mechanism 3 that holds the substrate 2 and transports (scans) it in a predetermined direction (scanning direction) (the Y direction in this example) during a coating process in which a liquid 4 is applied to the substrate 2. The scanning direction of the substrate 2 by the transport mechanism 3 may be one direction (e.g., the +Y direction) or two directions (the +Y direction and the -Y direction). The transport mechanism 3 may 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 may 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 particular shape, but may be, for example, rectangular or circular. The substrate 2 may have, for example, a pixel array region 9 and one or more alignment marks 10. The pixel array region 9 may have a plurality of pixel regions. The liquid application apparatus 1 may be configured to apply or arrange the liquid 4 to each pixel region. Each pixel region may be, for example, an area surrounded by a bank.

[0012] The liquid application apparatus 1 may include a discharge unit 5 that discharges droplets of the liquid 4 toward the substrate 2. The discharge unit 5 may have, for example, multiple discharge ports. In one example, the discharge unit 5 may include multiple discharge ports 5r, multiple discharge ports 5g, and multiple discharge ports 5b. The multiple discharge ports 5r discharge the organic material liquid 4 for forming a light-emitting layer that emits light of a red wavelength. The multiple discharge ports 5g discharge the organic material liquid 4 for forming a light-emitting layer that emits light of a green wavelength. The multiple discharge ports 5b discharge the organic material liquid 4 for forming a light-emitting layer that emits light of a blue wavelength. In one example, the multiple discharge ports 5r, the multiple discharge ports 5g, and the multiple discharge ports 5b may each be arranged to cover the width of the pixel array region 9 in the X direction perpendicular to the scanning direction. In one example, the liquid application apparatus 1 can apply the liquid 4 to all pixel regions in the pixel array region 9 during one scan of the substrate 2 in the Y direction.

[0013] The liquid application device 1 may also include a control unit 6 and a mist collection unit 11. The liquid application device 1 may further include a camera 7 and a height sensor 8. The control unit 6 may be configured, for example, by a PLD (abbreviation for Programmable Logic Device) such as an FPGA (abbreviation for Field Programmable Gate Array), or an ASIC (abbreviation for Application Specific Integrated Circuit), or a general-purpose or dedicated computer with an embedded program, or a combination of all or part of these.

[0014] The control unit 6 can measure the positions of the multiple alignment marks 10 using, for example, a camera 7, and thereby detect the position and orientation of the substrate 2. The control unit 6 can also control the transport mechanism 3 so that the substrate 2 is scanned in the Y direction relative to the discharge unit 5, while controlling the discharge unit 5 so that the liquid 4 is applied from the discharge unit 5 to each pixel region in the pixel array region 9 of the substrate 2 with the required accuracy. The number of scans can be determined so that the required amount of liquid 4 is applied to each pixel region. 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 a height sensor 8 and adjust the distance between the discharge unit 5 and the substrate 2. The distance between the discharge unit 5 and the substrate 2 can be set to, for example, 0.5 mm or less.

[0015] When droplets of liquid 4 are ejected from ejection unit 5, minute mist-like particles called mist are generated that do not contribute to pixel formation. The mist floats in space and can adhere to various parts, such as ejection unit 5. This can lead to ejection defects from ejection unit 5, as well as reduced measurement accuracy due to adhesion to camera 7 and height sensor 8, or reduced quality of the display panel due to adhesion to substrate 2. Therefore, it is desirable to quickly collect the floating mist.

[0016] The mist generated from the discharge unit 5 may move in the scanning direction together with the substrate 2 as the transport mechanism 3 scans the substrate 2. Therefore, the liquid coating apparatus 1 may include a mist collecting unit 11. The mist collecting unit 11 may be disposed near the discharge unit 5. In one example, two pairs of mist collecting units 11 may be disposed on either side of the discharge unit 5 in a direction parallel to the scanning direction of the substrate 2 by the transport mechanism 3. In this case, only the mist collecting unit 11 on the downstream side in the scanning direction may be operated, or both the mist collecting units 11 on the downstream and upstream sides in the scanning direction may be operated. In another example, the mist collecting units 11 may be disposed on both sides of each of the discharge ports 5r, 5g, and 5b. The discharge unit 5 and the mist collecting unit 11 may be integrated. The transport mechanism 3, the discharge unit 5, the camera 7, and the height sensor 8 may be disposed in the internal space 408 of the chamber 12.

[0017] In conventional configurations, the mist collected by the mist collecting unit aggregates and liquefies inside the mist collecting unit, and this can cause problems by dripping onto the substrate 2 and contaminating the substrate 2. The liquid coating apparatus 1 of the first embodiment is provided with a function to more reliably prevent the occurrence of such problems.

[0018] FIG. 2 is a schematic perspective view showing the configuration of the mist collecting unit 11. FIG. 3 is a schematic cross-sectional view showing the AA section of FIG. 2. FIG. 4 is a schematic cross-sectional view showing the BB section of FIG. 2. The mist collecting unit 11 may include a suction flow path 320 that sucks in mist 306 and a liquid receiving portion 305 that receives liquid produced by condensation of the mist 306. The suction flow path 320 may include a suction port 301 that sucks in the mist 306 and an outlet 202 that discharges the mist 306. The suction flow path 320 may also include an ascending flow path 309 that extends upward toward the outlet 202 and an inclined flow path 302 that extends obliquely upward from the suction port 301 toward the ascending flow path 309 to merge with the ascending flow path 309. The liquid receiving portion 305 may be disposed below the ascending flow path 309.

[0019] The ascending flow path 309 may be defined by a plurality of walls including a first wall 308 partially facing the inclined flow path 302. The mist 306 condenses at the first wall 308 to form liquid, and the liquid may move along the first wall 308 to the liquid receiving portion 305. The plurality of walls defining the ascending flow path 309 may include a second wall 313 facing the first wall 308, and the second wall 313 may be disposed above the liquid receiving portion 305. The second wall 313 may include a portion parallel to the first wall 308. An inclined surface 302a constituting the upper surface of the inclined flow path 302 may be connected to the second wall 313. A connection portion 323 between the inclined surface 302a and the second wall 313 may be disposed above the liquid receiving portion 305. The lower surface of the inclined flow path 302 may be formed by an inclined surface 302b. The inclined surface 302b may be parallel to the inclined surface 302a or may be non-parallel to the inclined surface 302a.

[0020] The inclined surface 302a may be provided with a recess 303 recessed in a direction away from the liquid receptacle 305. The recess 303 (its longitudinal direction) may extend horizontally (parallel to the X direction). At least a portion of the recess 303 may be disposed above the liquid receptacle 305. The first ridge 321 forms a boundary (boundary line) between the recess 303 and the inclined surface 302a. The second ridge 322 is located between the first ridge 321 and the suction port 301 and forms another boundary (boundary line) between the recess 303 and the inclined surface 302a. Of the first ridge 321 and the second ridge 322, at least the first ridge 321 may be disposed above the liquid receptacle 305. Preferably, both the first ridge 321 and the second ridge 322 are disposed above the liquid receptacle 305. The liquid application device 1 or the mist collection unit 11 may include a liquid recovery unit 330 that recovers the liquid (liquid formed by condensation of the mist 306) that has accumulated in the liquid receiving unit 305. The liquid recovery unit 330 may include a recovery pipe 304 having a plurality of holes 310 that sucks the liquid that has accumulated in the liquid receiving unit 305.

[0021] The mist collection unit 11 may include a first supply unit 333 including one or more first supply ports 311 that supply gas to the space above 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 the space. The first supply port 311 may be arranged on the side of the suction port 301 in the scanning direction (predetermined direction) of the substrate 2, and the second supply port 312 may be arranged on the side of the suction port 301 in the opposite direction to the scanning direction.

[0022] The suction port 301 can be arranged to open in an opposing surface 314 that faces the substrate 2. The suction port 301 can be arranged to face the substrate 2 held by the substrate stage of the transfer mechanism 3 so that, for example, its width in the short side direction (Y direction) is within a range of 1 mm to 10 mm and its width in the long side direction (X direction) is equal to or greater than the width of the pixel array region 9. The distance between the substrate 2 and the suction port 301 can be within a range of 0.1 mm to 5 mm, for example. From another perspective, the distance between the substrate 2 and the opposing surface 314 in which the suction port 301 opens can be within a range of 0.1 mm to 5 mm, for example. The distance between the substrate 2 and the suction port 301 (the distance between the substrate 2 and the opposing surface 314) can be the same as the distance between the substrate 2 and the discharge unit 5 (the lower surface).

[0023] The suction flow path 320 is connected from the suction port 301 to the exhaust port 202, and the gas containing the mist 306 sucked through the suction port 301 is exhausted through the exhaust port 202. One end of the inclined flow path 302 may 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 (normal to the upper surface of the substrate 2) is within a range of 20 to 70 degrees, preferably within a range of 30 to 60 degrees, and more preferably within a range of 40 to 50 degrees, and may be, for example, 45 degrees. The angle θ may be determined depending on the flow rate and flow velocity of the gas to be sucked, the arrangement space for the mist collecting unit 11, etc.

[0024] The connecting portion between the inclined flow channel 302 and the ascending flow channel 309 constitutes a direction change portion that changes the flow direction of the sucked gas. In this example, the angle φ between the direction (axial direction) of the inclined flow channel 302 and the direction (axial direction) of the ascending flow channel 309 is equal to θ, and may be, for example, 45 degrees.

[0025] A portion of the liquid receptacle 305 may be formed by a first wall surface 308. The liquid receptacle 305 may be disposed to extend in the X direction. The diameter of the recovery pipe 304 of the liquid recovery unit 330 may be, for example, 1 mm to 30 mm, the diameter of the multiple holes 310 may be, for example, 0.1 mm to several mm, and the pitch of the multiple holes 310 may be, for example, 1 mm to several tens of mm. The recovery pipe 304 may be connected to a reduced pressure source 220 via a joint 204 and a recovery path 221. By reducing the pressure inside the recovery pipe 304, the liquid accumulated in the liquid receptacle 305 may be recovered through the multiple holes 310. An ejector or the like may be used as the reduced pressure source 220. A gas-liquid separator that separates gas and liquid may be disposed between the liquid receptacle 305 and the reduced pressure source 220. Instead of providing the recovery pipe 304, an outlet may be provided at the end of the liquid receptacle 305.

[0026] The depth of the recess 303 (the distance between the bottom surface of the recess 303 and the inclined surface 302a) may be within a range of, for example, several mm to 20 mm. The width of the recess 303 (the distance between the first ridge 321 and the second ridge 322) may be within a range of, for example, several mm to 20 mm.

[0027] The first supply port 311 and the second supply port 312 may be arranged to open to the opposing surface 314. The first supply port 311 and the second supply port 312 are arranged to face the substrate 2 so that their widths in the short direction (Y direction) are within a range of 1 mm to 10 mm and their widths in the long direction (X direction) are equal to or 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 may be within a range of 0.1 mm to 5 mm, for example. The distance between the substrate 2 and the first supply port 311 and the second supply port 312 may be the same as the distance between the substrate 2 and the discharge section 5 (the lower surface thereof).

[0028] The first supply unit 333 may include a first supply port 311, a first supply flow path 403, a first introduction port 203, and a first pressurized source 213. The first supply port 311 communicates with the first introduction port 203 through the first supply flow path 403, and the first introduction port 203 is connected to the pressurized source 213. The pressurized source 213 may include, for example, a pressure generator, a pressure regulator, and a flow rate adjustment valve. The second supply unit 331 may include, in addition to the second supply port 312, a second introduction port 201 and a second pressurized source 211. The second supply port 312 communicates with the second introduction port 201, and the second introduction port 201 is connected to the pressurized source 211. The pressurized source 211 may include, for example, a pressure generator, a pressure regulator, and a flow rate adjustment valve.

[0029] The first pressurized source 213 and the second pressurized 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 width (Y direction) of the first supply port 311 and the second supply port 312 is 5 mm or less.

[0030] The outlet 202 is connected to a reduced pressure source 212. The reduced pressure source 212 may include, for example, an ejector. A gas-liquid separator that separates gas and liquid, and / or a flow meter may be disposed between the outlet 202 and the reduced pressure source 212. The liquid application apparatus 1 may include a plurality of outlets 202. While the first and second pressurization sources 213 and 211 can pressurize gas to several atmospheres or more, the reduced pressure source 212 can only reduce the pressure to minus 1 atmosphere (relative pressure). Therefore, the number of outlets 202 may be greater than the number of first introduction parts 203 and second introduction parts 201. The amount of gas discharged from the outlet 202 may be adjusted to be greater than the amount of gas supplied to the first introduction part 203 and the second introduction part 201.

[0031] To form an organic layer in each pixel region of the pixel array region 9 of the substrate 2, the substrate 2 is driven to scan in the +Y direction by the transport mechanism 3, while the discharge unit 5 discharges a liquid as a material for the organic layer, and the liquid is applied to the pixel array region 9 of the substrate 2. At this time, mist 306 is generated that does not contribute to the formation of the organic layer. The mist 306 can move downstream (in the +Y direction) from the space below the discharge unit 5 as the substrate 2 moves.

[0032] The gas supplied from the first supply port 311 of the mist collecting unit 11 collides with the substrate 2, forming an airflow directed toward the suction port 301 on the upstream side. Therefore, the mist 306 that has moved from the discharge unit 5 to the first supply port 311 is transported to the suction port 301 by the airflow. In addition, the gas supplied from the second supply port 312 flows along the opposing surface 314 of the mist collecting unit 11 and is sucked into the suction port 301. At this time, the mist 306 is sandwiched between the gas supplied from the first supply port 311 and the gas supplied from the second supply port 312 and is guided into the suction port 301. Therefore, adhesion of the mist 306 to the inclined surfaces 302a and 302b can be reduced.

[0033] The gas sucked through the inclined flow path 302 defined by the inclined surfaces 302a and 302b changes direction when it flows into the ascending flow path 309 and is discharged from the outlet 202. At this time, part of the mist 306 collides with the first wall surface 308 that defines the ascending flow path 309 and adheres to the first wall surface 308. As the amount of mist 306 adhering to the first wall surface 308 increases, it condenses and liquefies, and the liquid moves along the first wall surface 308 to the liquid receiving section 305.

[0034] The larger the angle φ, the more likely the mist 306 will collide with the first wall surface 308. This means that the amount of mist 306 discharged through the outlet 202 will decrease. The angles θ and φ can be determined taking into consideration the size and ease of manufacturing of the mist collecting unit 11, the amount of mist 306, etc.

[0035] Mist 306 may also adhere to second wall surface 313 on the opposite side of first wall surface 308. In this case, liquid generated by condensation (liquefaction) of mist 306 moves downward along second wall surface 313, then drops into liquid receptacle 305, and accumulates therein. The liquid accumulated in liquid receptacle 305 is recovered by liquid recovery unit 330. More specifically, the liquid accumulated in liquid receptacle 305 is sucked into recovery pipe 304 through hole 310 of recovery pipe 304, and is sucked (recovered) into reduced pressure source 220 via joint 204 and recovery path 221. Control unit 6 can control the recovery of the liquid accumulated in liquid receptacle 305 by controlling reduced pressure source 220.

[0036] Some of the liquid that has moved downward along the second wall surface 313 may move beyond the connecting portion 323 onto the inclined surface 302a. However, such liquid is captured by the recess 303 (or the first ridge 321) provided on the inclined surface 302a and falls into the liquid receptacle 305.

[0037] The control unit 6 can control the reduced pressure source 220 (liquid recovery unit 330) to recover the liquid accumulated in the liquid receptacle 305 when the mist collecting unit 11 is not collecting mist, for example, when replacing the substrate 2. Here, when the liquid recovery unit 330 recovers the liquid, gas may be sucked in along with the liquid through the hole 310. In this case, the flow of gas sucked through the inclined flow path 302 is disturbed, which may cause the mist 306 to adhere to the inclined surfaces 302a and 302b and condense, generating liquid. The liquid generated on the inclined surfaces 302a and 302b due to condensation may move downward along the inclined surfaces 302a and 302b and fall through the suction port 301. Therefore, as described above, the control unit 6 may control the reduced pressure source 220 (liquid recovery unit 330) to recover the liquid accumulated in the liquid receptacle 305 when the mist collecting unit 11 is not collecting mist, for example, when replacing the substrate 2.

[0038] As described above, according to the first embodiment, the gas containing the mist 306 sucked through the suction port 301 passes through the inclined flow path 302, then changes direction and flows into the ascending flow path 309, and can be discharged through the outlet 202. Here, when the gas that has passed through the inclined flow path 302 changes direction and flows into the ascending flow path 309, the mist 306 collides with the first wall surface 308 and condenses, and the liquid that is generated thereby can be collected by the liquid receiver 305.

[0039] A liquid application apparatus 1 according to a second embodiment will be described below with reference to FIG. 5. FIG. 5 corresponds to a cross-sectional view schematically illustrating the AA cross section in FIG. 2. Matters not mentioned in the description of the second embodiment may follow 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 unit 203 and the second introduction unit 201 increases or decreases, the pressure in the space between the substrate 2 and the facing surface 314 increases or decreases accordingly. Also, in the first embodiment, when the flow rate of the gas discharged from the outlet 202 increases or decreases, the pressure in the space between the substrate 2 and the facing surface 314 increases or decreases accordingly. Fluctuations in the space between the substrate 2 and the facing surface 314 can cause the discharge of droplets from the discharge unit 5 to become unstable or increase the amount of mist generated. The second embodiment is advantageous for stabilizing the discharge of droplets from the discharge unit 5 and / or reducing the amount of mist generated.

[0040] The distance h1 between the substrate 2 and the facing surface 314 is greater than the distance h2 between the substrate 2 and the discharge section 5 (the surface on which the discharge ports 5r, 5g, and 5b are provided). In one example, h1 is 1 mm or more, and h2 is 0.5 mm or less.

[0041] In the second embodiment, the second introduction part 201 communicates with an internal space 408 of the chamber 12 of the liquid application apparatus 1 illustrated in FIG. 1. The internal space 408 can be maintained at a reference pressure by an environmental control device (not shown). The second supply port 312 can have a short width of 1 to 10 mm. The second supply port 312 is connected to a 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 part 331 can have, for example, a rectifying part (R-shaped part) 402 that rectifies the flow of gas so that the gas is discharged from the second supply port 312 in a direction along the surface of the substrate 2.

[0042] The first supply flow path 403, which connects the first supply port 311 and the first introduction part 203, may include one or more narrowed portions 405a, 405b and one or more non-narrowed portions 404a, 404b. The narrowed portions 405a, 405b may have a minimum width (Y direction) of 0.5 mm or less. The non-narrowed portions 404a, 404b may have a minimum width (Y direction) of several mm. The first supply part 333 (first supply flow path 403) may include an expanded portion 407 whose cross-sectional area increases toward the first supply port 311.

[0043] The mist collecting unit 11 may include a protrusion 410 that protrudes toward the substrate 2 so as to constitute at least a part of a wall that surrounds the space that the opposing surface 314 faces. The distance between the substrate 2 and the protrusion 410 may be h2. In other words, the distance between the substrate 2 and the protrusion 410 may be the same as the distance between the substrate 2 and the discharge unit 5.

[0044] The suction port 301 is connected to a reduced pressure source 212 that generates a pressure lower than a reference pressure (here, the pressure of the internal space 408 of the chamber 12). The first supply port 311 is connected to a pressurized source 213 that generates a pressure higher than the reference pressure, and the second supply port 312 is connected to the internal space 408, which is a space having the reference pressure. The reduced pressure source 212 and the pressurized source 213 can be configured, adjusted, or controlled so that the flow rate Q1 of the gas sucked into the suction port 301 is greater than the flow rate Q2 of the gas supplied from the first supply port 311. The reduced pressure source 212 and the pressurized source 213 can be controlled, for example, by the control unit 6. The flow rate Q3 of the substrate introduced into the second introduction part 201 is the difference between Q2 and Q1. In other words, Q3 = Q2 - Q1. In one example, the width (Y direction) and length L (Z direction) of the second gas flow path 401 can be determined so that the pressure loss occurring in the second gas flow path 401 when gas flows through the second gas flow path 401 at a flow rate Q3 is 50 Pa or less.

[0045] Since the second supply port 312 is in communication with the internal space 408 of the chamber 12, the pressure in the space between the substrate 2 and the facing surface 314 (mist collecting section 11) is approximately equal to the pressure in the internal space 408. The difference in pressure between the space between the substrate 2 and the facing surface 314 (mist collecting section 11) and the pressure in the internal space 408 can be 50 Pa or less, as described above.

[0046] When the flow rate Q1 of the gas from the exhaust port 202 and the flow rate Q2 of the gas supplied to the first supply port 311 (first introduction part 203) fluctuate (the amounts of fluctuation are dQ1 and dQ2, respectively), the flow rate Q3 of the gas introduced into the second introduction part 201 also fluctuates. If the fluctuation of the flow rate Q3 is taken as dQ3 (= dQ2 - dQ1), the amount of fluctuation dQ3 is small compared to the flow rate Q3, and therefore the pressure fluctuation in the space between the substrate 2 and the opposing surface 314 (mist collection part 11) is also small, and may be, for example, about several Pa.

[0047] Pressure fluctuations in the space between the substrate 2 and the discharge unit 5 affect the discharge performance of the discharge unit 5. However, in the second embodiment, even if Q1 and / or Q2 unexpectedly fluctuate, the pressure fluctuations in the space between the substrate 2 and the facing surface 314, and as a result, the space between the substrate 2, the discharge unit 5, and the substrate 2, are small. Therefore, the second embodiment is advantageous for stabilizing the discharge of liquid from the discharge unit 5, thereby reducing the generation of mist.

[0048] The airflow supplied to the second introduction section 201 is rectified by the rectifier 402 of the second supply port 312 in a direction along the surface of the substrate 2 and is supplied to the space below the facing surface 314 of the mist collecting unit 11. Therefore, the mist 306 is not blown onto the substrate 2. This reduces contamination of the substrate 2. Furthermore, because the gas supplied from the second supply port 312 flows along the facing surface 314 of the mist collecting unit 11, adhesion and deposition of the mist 306 on the facing surface 314 is reduced. Furthermore, because the distance h1 between the substrate 2 and the facing surface 314 is greater than the distance h2 between the substrate 2 and the discharge section 5, the flow of the gas supplied from the second supply port 312 disrupts the trajectory of the mist 306, thereby preventing the mist 306 from adhering to the facing surface 314.

[0049] The gas introduced into the first introduction part 203 is sent to the first supply port 311 via the first supply flow path 403. Because of the large pressure loss in the narrowed portion 405a of the first supply flow path 403, the gas flowing through the first supply flow path 403 spreads in the X direction in the non-narrowed portion 404a upstream of the narrowed portion 405a before flowing into the narrowed portion 405a. Similarly, the gas spreads in the X direction in the non-narrowed portion 404b before flowing into the narrowed portion 405b. Therefore, the gas supplied from the first supply port 311 flows at a substantially uniform flow rate in the X direction.

[0050] The expanding portion 407, whose cross-sectional area increases toward the first supply port 311, smoothly expands the gas that has passed through the narrowing portion 405b in the Y direction, allowing the gas to be blown out of the first supply port 311 at a desired flow rate. In one example, the width of the first supply port 311 may be in the range of 1 mm to 5 mm, and the flow rate of the gas blown out of the first supply port 311 may be in the range of 1 m / s to 5 m / s.

[0051] 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, most of the gas supplied from the first supply port 311 flows from below the convex portion 410 toward the suction port 301 without leaking out to the outside of the mist collecting part 11. Therefore, the mist 306 can be collected effectively.

[0052] As described above, according to the second embodiment, the second gas flow path 401 communicates with the internal space 408 of the chamber 12 of the liquid coating apparatus 1, thereby reducing pressure fluctuations in the space between the substrate 2 and the discharge unit 5. As a result, the discharge of droplets from the discharge unit 5 is stabilized, and the generation of mist is reduced. Furthermore, the gas supplied from the second supply port 312 does not disturb the trajectory of the mist 306, thereby reducing adhesion of the mist to the opposing surface 314 between the substrate 2 and the mist collecting unit 11. Furthermore, the first supply flow path 403 has the narrowed portions 405a and 405b and the non-narrowed portions 404a and 404b, allowing the gas to be supplied in the X direction (non-scanning direction) at a substantially uniform and desired flow rate. Furthermore, the provision of the convex portion 410 allows most of the gas supplied from the first supply port 311 to flow toward the suction port 301, thereby allowing the mist 306 to be efficiently collected.

[0053] Hereinafter, a liquid application apparatus 1 according to a third embodiment will be described with reference to Figures 6 and 7. Matters not mentioned in the description of the third embodiment may follow the description of the first or second embodiment. In the third embodiment, Figure 7 is a cross-sectional view schematically showing the AA cross section of Figure 6.

[0054] As described above, the liquid (ink) collected by the mist collecting unit 11 is held by the liquid receiving unit 305 and recovered by the liquid recovery unit 330. However, when a liquid that dries quickly is used, there is a possibility that the liquid will dry and solidify in the liquid receiving unit 305. In particular, when the liquid recovery unit 330 includes a recovery pipe 304 having a plurality of holes 310, there is a possibility that the holes 310 will become clogged with solidified material, making it impossible to recover the liquid. Therefore, the liquid application apparatus 1 of the third embodiment is provided with a cleaning unit 520 that cleans the liquid recovery unit 330 (and the liquid receiving unit 305).

[0055] 6 , the cleaning unit 520 may include, for example, a cleaning liquid supply port 501 provided in the side wall 205 of the liquid receptacle 305. The cleaning liquid supply port 501 is in communication with the liquid receptacle 305. The cleaning unit 520 may further 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 step, the control unit 6 controls the cleaning liquid supply source 511 so that a predetermined amount of cleaning liquid 502 is supplied to the liquid receptacle 305.

[0056] When the liquid receptacle 305 is filled with the cleaning liquid 502, the material (ink) held in the liquid receptacle 305 dissolves in the cleaning liquid 502. In particular, when the holes 310 of the recovery pipe 304 of the liquid recovery unit 330 are immersed in the cleaning liquid 502, the material that has adhered to and solidified in the holes 310 dissolves and can be removed from the holes 310. The cleaning liquid 502 can then be recovered by the liquid recovery unit 330.

[0057] Cleaning of the liquid recovery unit 330 can be performed depending on the drying speed of the liquid (ink). For liquids that dry slowly, the cleaning process can be performed several times a day, for example. Conversely, for liquids that dry quickly, the cleaning process can be performed every time a substrate is processed, for example.

[0058] The method for recovering the liquid (ink) by the liquid recovery unit 330 and the method for supplying the cleaning liquid by the cleaning unit 520 are not limited to a specific type. For example, the liquid receptacle 305 may be constantly filled with the cleaning liquid 502 so that the hole 310 of the recovery pipe 304 is always immersed in the cleaning liquid 502. In this case, the mist collected by the mist collecting unit 11 can be dropped into the liquid receptacle 305 and immediately dissolved in the cleaning liquid 502. Therefore, unlike the cleaning method described above, additional time is not required to dissolve the solidified liquid (ink) in the liquid receptacle 305 into the cleaning liquid 502, thereby shortening the cleaning time. In this case, when the cleaning process begins, the control unit 6 operates the reduced pressure source to recover the liquid (ink) and cleaning liquid 502 stored in the liquid receptacle 305. Thereafter, the control unit 6 operates the cleaning liquid supply source 511 to supply the cleaning liquid 502 to the liquid receptacle 305 until the hole 310 of the recovery pipe 304 is immersed in the cleaning liquid 502. As a result, even after the cleaning process is completed, the amount of cleaning liquid 502 in liquid receptacle 305 remains constant.

[0059] As another method for constantly filling the liquid receptacle 305 with cleaning liquid 502, a circulation system may be configured in which the cleaning liquid supply port 501 constantly supplies cleaning liquid 502 to the liquid receptacle 305, and at the same time the liquid recovery unit 330 recovers from the liquid receptacle 305 the same amount of cleaning liquid 502 as that supplied.

[0060] The liquid applied to the substrate 2 by the liquid application apparatus 1 may be, for example, a liquid containing a curable composition. The curable composition can be cured by applying curing energy such as light energy or thermal energy. Such a liquid application apparatus 1 may be incorporated into a film forming apparatus such as an imprinting apparatus or a planarizing apparatus, or may be used as a pretreatment apparatus for the film forming apparatus.

[0061] Below, an article manufacturing method for manufacturing an article using the liquid application device 1 will be described. The article manufacturing method may include a coating step of applying a liquid material onto a substrate using the liquid application device, a film formation step of processing the liquid material on the substrate to form a film, and a processing step of processing the substrate that has undergone the film formation step to obtain an article. In particular, an article manufacturing method for manufacturing a display panel as an article may include a coating step of applying a liquid organic material onto a substrate using the liquid application device, and a film formation step of drying and baking the liquid organic material on the substrate to form an organic material film. Also, an article manufacturing method for manufacturing a display panel may include a processing step of processing the substrate that has undergone the film formation step to obtain a display panel.

[0062] This specification and the accompanying drawings include the following disclosure: (Item 1) A liquid application device that applies a liquid to a substrate, a discharge unit that discharges droplets toward the substrate; a mist collecting unit that collects mist generated by the ejection of droplets from the ejection unit, The mist collecting unit includes a suction flow path that sucks the mist and a liquid receiving unit that receives liquid generated by condensation of the mist, the suction flow path includes a suction port that sucks in 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 portion is disposed below the ascending flow path. A liquid application device characterized by: (Item 2) The upward flow path is defined by a plurality of walls including a first wall that partially faces the inclined flow path. 2. The liquid application device according to item 1, (Item 3) The mist aggregates on the first wall surface and moves along the first wall surface to the liquid receiving portion. 3. The liquid application device according to item 2, (Item 4) The plurality of wall surfaces include a second wall surface facing the first wall surface, and the second wall surface is disposed above the liquid receiving portion. 4. The liquid application device according to item 3, (Item 5) the second wall surface includes a portion parallel to the first wall surface, 5. The liquid application device according to item 4, (Item 6) an inclined surface constituting an upper surface of the inclined flow channel is connected to the second wall surface; a connection portion between the inclined surface and the second wall surface is disposed above the liquid receiving portion; 6. The liquid application device according to item 4 or 5, (Item 7) The inclined surface is provided with a recess recessed in a direction away from the liquid receiving portion, The recess extends in a horizontal direction, and at least a portion of the recess is disposed above the liquid receiving portion. 7. The liquid application device according to item 6, (Item 8) a first ridge line that forms a boundary between the recessed portion and the inclined surface, and a second ridge line that is located between the first ridge line and the suction port and forms another boundary between the recessed portion and the inclined surface, at least the first ridge line being disposed above the liquid receiving portion; 8. The liquid application device according to item 7, (Item 9) Both the first ridge line and the second ridge line are disposed above the liquid receiving portion. 9. The liquid application device according to item 8, (Item 10) Further provided is a liquid recovery section that recovers the liquid accumulated in the liquid receiving section. 10. The liquid application device according to any one of items 1 to 9, characterized in that: (Item 11) the liquid recovery section includes a recovery pipe having a plurality of holes for sucking the liquid accumulated in the liquid receiving section. Item 11. The liquid application device according to item 10. (Item 12) Further comprising a cleaning unit that cleans the liquid recovery unit. 12. The liquid application device according to item 10 or 11, (Item 13) a transport mechanism that transports the substrate in a predetermined direction during a coating process in which a liquid is applied to the substrate; a first supply unit including a first supply port that supplies a gas to a space above the substrate; a second supply unit including a second supply port that supplies a gas to the space, The first supply port is disposed on a side of the suction port in the predetermined direction, and the second supply port is disposed on a side of the suction port in a direction opposite to the predetermined direction. 13. The liquid application device according to any one of items 1 to 12, characterized in that (Item 14) The suction port is connected to a reduced pressure source that generates a pressure lower than a reference pressure, the first supply port is connected to a pressurized source that generates a pressure higher than the reference pressure, and the second supply port is in communication with a space having the reference pressure. Item 14. The liquid application device according to item 13. (Item 15) The flow rate of the gas sucked into the suction port is greater than the flow rate of the gas supplied from the first supply port. Item 15. The liquid application device according to item 14. (Item 16) the second supply port is configured to discharge gas from the second supply port in a direction along the surface of the substrate. 16. The liquid application device according to item 14 or 15, (Item 17) the first supply section includes an expanding section whose cross-sectional area increases toward the first supply port; 17. The liquid application device according to any one of items 14 to 16, (Item 18) the first supply section includes a constricted section and a non-constricted section; 18. The liquid application device according to any one of items 14 to 17, (Item 19) the suction port is open on a surface facing the substrate, The mist collecting portion includes a protrusion protruding toward the substrate so as to constitute at least a part of a wall portion surrounding a space facing the opposing surface. 19. The liquid application device according to any one of items 1 to 18, (Item 20) A method for manufacturing a display panel, comprising: A coating process of coating a liquid organic material onto a substrate using the liquid coating apparatus according to any one of items 1 to 19; a film formation step of drying and baking the liquid organic material on the substrate to form an organic material film; a processing step of processing the substrate that has been subjected to the film forming step to obtain the display panel; A method for manufacturing a display panel, comprising: [Explanation of symbols]

[0063] 1: liquid application device, 2: substrate, 3: transport mechanism, 4: liquid, 5: discharge part, 11: mist collection part, 202: discharge port, 301: suction port, 306: mist, 304: recovery pipe, 305: liquid receiver, 302: inclined flow path, 309: upward flow path, 320: suction flow path

Claims

1. A liquid application device that applies a liquid to a substrate, a discharge unit that discharges droplets toward the substrate; a mist collecting unit that collects mist generated by the ejection of droplets from the ejection unit, The mist collecting unit includes a suction flow path that sucks the mist and a liquid receiving unit that receives liquid generated by condensation of the mist, the suction flow path includes a suction port that sucks in 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 portion is disposed below the ascending flow path. A liquid application device characterized by:

2. the ascending flow path is defined by a plurality of walls including a first wall partially facing the inclined flow path; 2. The liquid application device according to claim 1.

3. The mist aggregates on the first wall surface and moves along the first wall surface to the liquid receiving portion.

3. The liquid application device according to claim 2.

4. The plurality of wall surfaces include a second wall surface facing the first wall surface, and the second wall surface is disposed above the liquid receiving portion.

4. The liquid application device according to claim 3.

5. the second wall surface includes a portion parallel to the first wall surface; 5. The liquid application device according to claim 4.

6. an inclined surface constituting an upper surface of the inclined flow channel is connected to the second wall surface; a connection portion between the inclined surface and the second wall surface is disposed above the liquid receiving portion; 5. The liquid application device according to claim 4.

7. The inclined surface is provided with a recess recessed in a direction away from the liquid receiving portion, The recess extends in a horizontal direction, and at least a portion of the recess is disposed above the liquid receiving portion.

7. The liquid application device according to claim 6.

8. a first ridge line that forms a boundary between the recess and the inclined surface, and a second ridge line that is located between the first ridge line and the suction port and forms another boundary between the recess and the inclined surface, at least the first ridge line being disposed above the liquid receiving portion; 8. The liquid application device according to claim 7.

9. Both the first ridge line and the second ridge line are disposed above the liquid receiving portion.

9. The liquid application device according to claim 8.

10. Further provided is a liquid recovery section that recovers the liquid accumulated in the liquid receiving section.

2. The liquid application device according to claim 1.

11. the liquid recovery section includes a recovery pipe having a plurality of holes for sucking the liquid accumulated in the liquid receiving section.

11. The liquid application device according to claim 10.

12. Further comprising a cleaning unit that cleans the liquid recovery unit.

11. The liquid application device according to claim 10.

13. a transport mechanism that transports the substrate in a predetermined direction during a coating process in which a liquid is applied to the substrate; a first supply unit including a first supply port that supplies a gas to a space above the substrate; a second supply unit including a second supply port that supplies a gas to the space, the first supply port is disposed on a side of the suction port in the predetermined direction, and the second supply port is disposed on a side of the suction port in a direction opposite to the predetermined direction.

2. The liquid application device according to claim 1.

14. the suction port is connected to a reduced pressure source that generates a pressure lower than a reference pressure, the first supply port is connected to a pressurized source that generates a pressure higher than the reference pressure, and the second supply port is in communication with a space having the reference pressure; 14. The liquid application device according to claim 13.

15. a flow rate of the gas sucked into the suction port is greater than a flow rate of the gas supplied from the first supply port; 15. The liquid application device according to claim 14.

16. the second supply port is configured to discharge gas from the second supply port in a direction along the surface of the substrate.

15. The liquid application device according to claim 14.

17. the first supply section includes an expanding section whose cross-sectional area increases toward the first supply port; 15. The liquid application device according to claim 14.

18. the first supply section includes a constricted section and a non-constricted section; 15. The liquid application device according to claim 14.

19. the suction port is open on a surface facing the substrate, The mist collecting portion includes a protrusion protruding toward the substrate so as to constitute at least a part of a wall portion surrounding a space facing the opposing surface.

2. The liquid application device according to claim 1.

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

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