JP5052942B2 - Coating device - Google Patents

Description

  The present invention relates to a coating apparatus that applies a flowable material to a substrate.

  Conventionally, as disclosed in Patent Documents 1 and 2, as a device for applying a fluid material such as a resist solution on a semiconductor substrate (hereinafter simply referred to as “substrate”), the fluid material is continuously applied. 2. Description of the Related Art A coating apparatus that coats a fluid material in a plurality of parallel lines that are in contact with each other over the entire main surface of a substrate by scanning a nozzle for discharging on the substrate is known.

  In such a coating apparatus, various techniques for improving the uniformity of the film thickness of the flowable material have been proposed. For example, in Patent Document 1, a substrate coated with a coating solution by a resist coating apparatus is exposed to the solvent atmosphere of the coating liquid in a solvent atmosphere apparatus provided separately from the resist coating apparatus, so that the solvent adheres to the surface of the coating liquid. A technique is disclosed in which the viscosity of the surface of the coating liquid is reduced, and then an airflow is formed in the container in which the substrate is accommodated, and the surface of the coating liquid is flattened by the airflow. Patent Document 1 also discloses a technique for suppressing volatilization of the coating liquid by pressurizing the inside of the container in which the substrate coated with the coating liquid is accommodated.

In the coating film forming apparatus of Patent Document 2, a drying prevention plate that covers almost the entire substrate is provided at a position within 2 mm above the substrate, and a coating liquid for an insulating film is formed in a linear gap formed on the drying prevention plate. By scanning a nozzle that discharges the substrate with respect to the substrate, the coating liquid is uniformly applied onto the substrate. Thereby, a high concentration solvent atmosphere is formed between the substrate and the drying prevention plate, and drying of the coating solution applied to the substrate is suppressed. Further, in the coating film forming apparatus of Patent Document 2, a sponge member soaked with a solvent is provided on a drying prevention plate, and solvent vapor evaporating from the sponge member is supplied from a supply hole formed in the drying prevention plate to the substrate and the drying prevention plate. , The solvent concentration between the substrate and the drying prevention plate is further increased.
JP 2003-17402 A Japanese Patent Laid-Open No. 2005-13787

  By the way, a coating apparatus that applies a fluid material to a substrate by scanning a nozzle that discharges the fluid material is also used when a fluid material including a pixel forming material is applied to a substrate for a flat display device. Has been. In such an apparatus, for example, scanning between a plurality of nozzles arranged at a predetermined pitch and step movement of the substrate in a direction perpendicular to the scanning direction are repeated, so that the partition walls formed on the substrate The flowable material is applied in stripes to the plurality of grooves.

  On the substrate, the solvent component evaporates from each line of the flowable material, so that the pixel forming material is fixed on the substrate and a film of the pixel forming material is formed. Is sufficiently dispersed in each line of the fluid material, so that the film thickness of the pixel forming material becomes uniform.

  However, when the flowable material is applied by a plurality of nozzles, the flowable material is not applied to the rear side in the step movement direction of the substrate, and therefore, the plurality of nozzles are positioned at the rearmost side in the step movement direction. The concentration of the solvent component in the atmosphere is lower around the flowable material lines applied by the nozzles than the flowable material lines applied by the other nozzles.

  For this reason, the line of the flowable material applied by the rearmost nozzle dries faster than the line of the flowable material applied by the other nozzle, and the pixel forming material film formed on the substrate. The thickness becomes non-uniform. As a result, when the substrate is viewed as a whole, coating unevenness occurs, and the display quality of the flat display device after the product is manufactured may be deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the uniformity of the drying rate of the flowable material discharged from a plurality of discharge ports.

  The invention described in claim 1 is a coating apparatus that applies a fluid material to a substrate, and is arranged at equal intervals with respect to a substrate holding portion that holds the substrate and a sub-scanning direction parallel to the main surface of the substrate. A discharge mechanism that discharges a flowable material from a plurality of discharge ports toward a coating region on the main surface of the substrate, and the discharge mechanism in a main scanning direction that is perpendicular to the sub-scanning direction and parallel to the main surface. A movement mechanism that moves relative to the substrate and moves the substrate relative to the ejection mechanism in the sub-scanning direction each time the movement in the main scanning direction is performed; and the sub-scanning An airflow forming unit that forms a gas flow substantially parallel to the main surface of the substrate from the front side relative to the relative movement direction of the substrate in the direction toward the rear side in the relative movement direction between the discharge mechanism and the substrate.

  A second aspect of the present invention is the coating apparatus according to the first aspect, wherein the gas flow is formed over the entire length of the coating region in the main scanning direction by the air flow forming unit.

  A third aspect of the present invention is the coating apparatus according to the first or second aspect, wherein a relative position in the sub-scanning direction of the airflow forming unit with respect to the discharge mechanism is fixed.

  A fourth aspect of the present invention is the coating apparatus according to any one of the first to third aspects, wherein the gas is air.

  A fifth aspect of the present invention is the coating apparatus according to any one of the first to fourth aspects, wherein the air flow forming unit includes a delivery port for sending out the gas.

  Invention of Claim 6 is a coating device of Claim 5, Comprising: The said delivery port is arrange | positioned with respect to the said several discharge port of the said discharge mechanism in the said relative movement direction front side of the said board | substrate, The gas is delivered from the delivery port substantially parallel to the main surface of the substrate.

  A seventh aspect of the present invention is the coating apparatus according to any one of the first to sixth aspects, further comprising a gas heating unit that heats the gas toward the discharge mechanism.

  The invention according to an eighth aspect is the coating apparatus according to any one of the first to seventh aspects, wherein the substrate holding unit includes a substrate heating unit that heats the substrate.

  The invention described in claim 9 is the coating apparatus according to any one of claims 1 to 8, wherein the fluid material includes a pixel forming material for a flat display device.

  In the present invention, it is possible to improve the uniformity of the drying rate of the fluid material discharged from the plurality of discharge ports.

  FIG. 1 is a plan view showing a coating apparatus 1 according to the first embodiment of the present invention, and FIG. 2 is a front view of the coating apparatus 1. The coating apparatus 1 is an apparatus that applies a flowable material including a pixel forming material for a flat display device to a glass substrate 9 for flat display devices (hereinafter simply referred to as “substrate 9”). In the present embodiment, in the coating apparatus 1, a substrate 9 for an organic EL (Electro Luminescence) display device of an active matrix driving system is applied to a volatile solvent (in this embodiment, one of aromatic organic solvents). A fluid material (hereinafter referred to as “organic EL liquid”) including an organic EL material applied to the substrate 9 and a certain 4-methylanisole) is applied.

  As shown in FIG. 2, the coating apparatus 1 includes a substrate holding unit 11 that holds the substrate 9, and as shown in FIGS. 1 and 2, the substrate holding unit 11 is in a predetermined direction parallel to the main surface of the substrate 9. (Ie, the Y direction in FIG. 1, hereinafter referred to as “sub-scanning direction”) and a substrate moving mechanism 12 that rotates about an axis that is oriented in the vertical direction (that is, the Z direction). As shown in FIG. 2, the substrate holding unit 11 includes a heater 111 that is a substrate heating unit that heats the substrate 9 from below.

  The coating apparatus 1 also captures and detects an alignment mark (not shown) formed on the substrate 9 and detects (+ Z) of the substrate 9 held by the substrate holding unit 11 (see FIG. 2). ) Side main surface 90 (hereinafter referred to as “upper surface 90”), a coating head 14 that is a discharge mechanism that discharges a fluid material toward a coating region 91 (shown by being surrounded by a broken line in FIG. 1). A head moving mechanism 15 that horizontally moves the coating head 14 in a direction parallel to the upper surface 90 of the substrate 9 and perpendicular to the sub-scanning direction (that is, the X direction in FIG. 1 and hereinafter referred to as “main scanning direction”); Two liquid receiving portions 16 that are provided on both sides of the substrate holding portion 11 with respect to the moving direction (that is, the X direction) of the coating head 14 and receive the organic EL liquid from the coating head 14, and a fluid material in the coating head 14 Comprising a flowable material supply section 18 supplies, as shown in FIG. 1, a control unit 2 for controlling these configurations.

  As shown in FIGS. 1 and 2, the coating head 14 includes a plurality of (three in the present embodiment) nozzles 17 that continuously discharge the same type of organic EL liquid. The three nozzles 17 are arranged substantially linearly in the X direction (that is, the main scanning direction) and are slightly shifted in the Y direction (that is, the sub scanning direction). The discharge ports of the three nozzles 17 are arranged at equal intervals in the sub-scanning direction, and the distance in the sub-scanning direction between the two adjacent nozzles 17 is formed in advance on the coating region 91 of the substrate 9. It is made equal to three times the pitch between the partition walls extending in the main scanning direction (hereinafter referred to as “partition wall pitch”).

  When the organic EL liquid is applied to the application region 91 of the substrate 9, the organic EL liquid is discharged and applied from the three nozzles 17 to the three grooves formed between the partition walls. Between the two groove portions to which the organic EL liquid is applied by the coating device 1, two groove portions to which another type of organic EL liquid is applied are sandwiched by another coating device or the like.

  In the coating apparatus 1, the head moving mechanism 15 and the substrate moving mechanism 12 move the coating head 14 relative to the substrate 9 in the main scanning direction and the substrate 9 relative to the coating head 14 in the sub-scanning direction. It becomes a moving mechanism to move to. As will be described later, in the coating apparatus 1, when the organic EL liquid is applied to the substrate 9, the substrate 9 moves from the (−Y) side to the (+ Y) side in FIG. To do. That is, the (+ Y) side in FIG. 1 is the front side of the relative movement direction of the substrate 9 in the sub-scanning direction, and the (−Y) side is the rear side of the relative movement direction of the substrate 9 in the sub-scanning direction. In other words, the (+ Y) side in FIG. 1 is the downstream side of the movement of the substrate 9 in the sub-scanning direction, and the (−Y) side is the upstream side of the movement of the substrate 9.

  As shown in FIGS. 1 and 2, the coating apparatus 1 includes a substrate holding unit on the (+ Y) side of the discharge ports of the plurality of nozzles 17 of the coating head 14 (that is, on the front side in the relative scanning direction of the substrate 9 in the sub-scanning direction). 11 and the substrate moving mechanism 12 and a gas flow from the (+ Y) side to the (−Y) side by sending the gas toward the (−Y) side (that is, the substrate in the sub-scanning direction) 9 is further provided with an airflow forming unit 19 that forms an airflow from the front side of the relative movement direction 9 toward the rear side of the relative movement direction.

  Since the airflow forming unit 19 is fixed to a base (not shown) together with the substrate moving mechanism 12 and the head moving mechanism 15, the relative position of the airflow forming unit 19 with respect to the coating head 14 in the sub-scanning direction is fixed. The airflow forming unit 19 is disposed in the vicinity of the plurality of nozzles 17 of the coating head 14 in the sub-scanning direction, and the distance in the sub-scanning direction between the airflow forming unit 19 and the plurality of nozzles 17 is several cm. The Further, the airflow forming unit 19 is disposed on the upper side of the substrate 9 and in proximity to the upper surface 90 of the substrate 9.

  FIG. 3 is a longitudinal sectional view showing the vicinity of the airflow forming unit 19. As shown in FIGS. 2 and 3, the airflow forming unit 19 includes a delivery port 191 that delivers gas to the (−Y) side facing the plurality of nozzles 17 of the coating head 14, and the delivery port 191 is a main scan. The total length in the direction is a slit shape longer than the total length in the main scanning direction of the application region 91 (see FIG. 1) of the substrate 9.

  In the coating apparatus 1, the airflow forming unit 19 is connected to a compressor (not shown), and air (dry air having a humidity lower than that of normal air) is supplied from the compressor to the airflow forming unit 19. Air is sent out toward the (−Y) side in parallel to the upper surface 90 of the substrate 9 from the delivery port 191 arranged on the (+ Y) side (that is, the front side in the relative movement direction of the substrate 9) with respect to the plurality of nozzles 17. The As a result, an air flow parallel to the upper surface 90 of the substrate 9 is formed between the tips (that is, ejection ports) of the plurality of nozzles 17 and the substrate 9. In the airflow forming unit 19, the outlet 191 is provided over the entire length of the application region 91 of the substrate 9 in the main scanning direction, so that the air flow is formed over the entire length of the application region 91 in the main scanning direction. Is done.

  The speed of the air flow formed by the airflow forming unit 19 (that is, the flow velocity) is preferably 0.15 m or more and 0.35 m or less per second (more preferably, 0.1. 2 m or more and 0.3 m or less), and in this embodiment, the speed is 0.21 m / s. Note that the air flow formed by the airflow forming unit 19 may be slightly inclined with respect to the upper surface 90 as long as it is substantially parallel to the upper surface 90 of the substrate 9.

  Next, application of the organic EL liquid by the application apparatus 1 will be described. FIG. 4 is a diagram showing a flow of application of the organic EL liquid. When the organic EL liquid is applied by the coating apparatus 1, first, the substrate 9 is placed and held on the substrate holding unit 11, and the substrate moving mechanism 12 is driven based on the output from the alignment mark detection unit 13. Then, the substrate 9 moves and rotates, and is positioned at the application start position indicated by the solid line in FIG. 1 (step S11). In other words, the coating head 14 is located at the start end of relative movement in the sub-scanning direction with respect to the substrate 9. Further, the application head 14 is previously positioned in a standby position indicated by a solid line in FIGS. 1 and 2 (that is, above the (−X) side liquid receiving part 16 in FIG. 1) in the main scanning direction. Yes.

  Subsequently, the air flow forming unit 19 is controlled by the control unit 2 to start sending air from the delivery port 191, and an air flow parallel to the upper surface 90 is formed on the substrate 9 (step S12). Next, the coating head 14 is controlled by the control unit 2 to start discharging the organic EL liquid from the three nozzles 17 (step S13). Further, the head moving mechanism 15 is controlled to control the coating head 14 in the main scanning direction. Movement (that is, movement from the (−X) side in FIG. 1 to the (+ X) side) is started.

  In the coating apparatus 1, when the coating head 14 is relatively moved in the main scanning direction, the organic EL liquid is continuously discharged from the nozzle 17 toward the substrate 9, thereby forming three grooves in the coating region 91 of the substrate 9. The organic EL liquid is applied in a stripe shape (step S14). In addition, since the non-application area | region of the (+ X) side and (-X) side of the application | coating area | region 91 in FIG.

  When the coating head 14 moves to the standby position indicated by a two-dot chain line in FIGS. 1 and 2 (that is, above the (+ X) side liquid receiver 16), the substrate moving mechanism 12 is driven, and the substrate 9 is moved to the substrate. The holding unit 11 moves in the (+ Y) direction (that is, the sub-scanning direction) by a distance equal to 9 times the partition wall pitch (step S15). At this time, in the coating head 14, the organic EL liquid is continuously discharged from the three nozzles 17 toward the liquid receiving unit 16.

  In the coating apparatus 1, a quick-drying solvent is used as the solvent of the organic EL liquid, and the substrate 9 is heated by the heater 111 of the substrate holding unit 11, so that it is applied to the application region 91 by the nozzle 17. The organic EL liquid is quickly dried immediately after being applied and during the movement of the substrate 9 in the sub-scanning direction in step S15 (that is, the solvent is evaporated from the organic EL liquid), and the organic EL material is in a semi-dry state. A film of organic EL material is formed on the substrate 9.

  When the movement of the substrate 9 in the sub-scanning direction is completed, it is confirmed by the control unit 2 whether or not the substrate 9 and the substrate holding unit 11 have moved to the application end position indicated by the two-dot chain line in FIG. 1 (step S16). ). If the application head 14 has not moved to the application end position, the process returns to step S14, and the application head 14 discharges the organic EL liquid from the three nozzles 17 while the (+ X) side of the substrate 9 is in the (−X) direction ( That is, the organic EL liquid is applied to the groove of the application region 91 of the substrate 9 by moving in the main scanning direction (step S14). Thereafter, it is confirmed whether or not the substrate 9 has moved in the sub-scanning direction and has moved to the coating end position (steps S15 and S16).

  In the coating apparatus 1, the movement of the coating head 14 in the main scanning direction and the step movement toward the (+ Y) side of the substrate 9 are repeated until the substrate holding unit 11 and the substrate 9 are positioned at the coating end position (that is, the substrate 9 is moved to the (+ Y) side). Each time the coating head 14 is moved relative to the substrate 9 in the main scanning direction, the substrate 9 is moved relative to the coating head 14 in the sub-scanning direction). The organic EL liquid is applied in stripes arranged at a pitch equal to three times the partition wall pitch (steps S14 to S16). In the coating apparatus 1, the direction in which the application of the organic EL liquid proceeds on the substrate 9 in the sub-scanning direction (that is, the relative movement direction of the coating head 14 with respect to the substrate 9) is the movement direction of the substrate 9 by the substrate moving mechanism 12. Is in the opposite direction.

  When the substrate 9 moves to the application end position, the discharge of the organic EL liquid from the three nozzles 17 is stopped (step S17), and further, the air supply from the airflow forming unit 19 is stopped (step S18). Then, the application of the organic EL liquid to the substrate 9 by the coating apparatus 1 is completed. The substrate 9 that has been applied by the coating apparatus 1 is transported to another coating apparatus or the like, and two organic EL liquids other than the organic EL liquid applied by the coating apparatus 1 are applied. In the coating apparatus 1, the organic EL liquid is actually continuously applied to the plurality of substrates 9. In this case, air is continuously sent from the airflow forming unit 19 until the application of the organic EL liquid to the plurality of substrates 9 is completed without stopping the air sending from the airflow forming unit 19 in step S18. Also good.

  As described above, in the coating apparatus 1, when the coating head 14 moves in the main scanning direction, the organic EL liquid ejected from the three nozzles 17 is applied to the coating region 91 of the substrate 9 in a stripe shape. Is done. At this time, among the three nozzles 17, the line of the organic EL liquid applied by the central nozzle 17 is the line of the organic EL liquid applied in parallel by the (+ Y) side and (−Y) side nozzles 17. The organic EL liquid line applied by the (+ Y) side nozzle 17 is sandwiched between the lines, and the organic EL liquid line applied in parallel by the central nozzle 17 and already applied on the substrate 9. It is sandwiched between lines of organic EL liquid. For this reason, the concentration of the solvent component of the organic EL liquid in the atmosphere is high around the center and the line of the organic EL liquid applied by the (+ Y) side nozzle 17.

  Further, in the coating apparatus 1, the (+ Y) side and central nozzles 17 cause the air flow from the (+ Y) side parallel to the upper surface 90 of the substrate 9 formed by the airflow forming unit 19 to the (−Y) direction. The atmosphere around the line of the applied organic EL liquid is expanded in the (−Y) direction. As a result, the concentration of the solvent component of the organic EL liquid in the atmosphere is increased around the line of the organic EL liquid applied by the (−Y) side nozzle 17, and the liquid is applied by the three nozzles 17. The uniformity of the concentration of the solvent component in the atmosphere is improved around the line of the organic EL liquid.

  Here, assuming that a coating apparatus in which no airflow forming unit is provided is a comparative example, in the coating apparatus of the comparative example, the nozzle on the (+ Y) side (that is, the front side in the relative scanning direction of the substrate in the sub-scanning direction) and the central nozzle As described above, the concentration of the solvent component of the organic EL liquid in the atmosphere is high around the line of the organic EL liquid applied by the above. However, on the (−Y) side of the line of the organic EL liquid applied by the nozzle on the (−Y) side (that is, the rear side in the relative movement direction of the substrate in the sub-scanning direction), there are no other organic EL liquid lines. The line of the organic EL liquid applied in parallel by the central nozzle is arranged only on the (+ Y) side without being applied.

  Therefore, the solvent of the organic EL liquid around the line of the organic EL liquid applied by the nozzle on the (−Y) side is compared with the periphery of the line of the organic EL liquid applied by the nozzle on the (+ Y) side and the center. The concentration of the component becomes low, and the drying speed of the (−Y) side organic EL liquid line becomes larger than the (+ Y) side two organic EL liquid lines. Further, around the line of the organic EL liquid on the (−Y) side, the concentration of the solvent component of the organic EL liquid in the atmosphere on the (−Y) side of the line is lower than the concentration on the (+ Y) side of the line. Thus, the (−Y) side portion of the line dries faster than the (+ Y) side portion.

  FIG. A shows three films | membranes 93a of the organic EL material formed in the application | coating area | region 91a on the board | substrate 9a, when a solvent evaporates from the organic EL liquid apply | coated with the three nozzles of the coating device of a comparative example. It is sectional drawing. FIG. In A, for convenience of illustration, the illustration of the partition formed in the coating region 91a of the substrate 9a is omitted, and the height of the film 93a is drawn larger than the actual height (also in FIG. 5.B). The same).

  In the coating apparatus of the comparative example, as described above, the (−Y) side portion of the (−Y) side organic EL liquid line dries faster than the (+ Y) side portion. As shown in A, in the film 93a on the (−Y) side, the film thickness at the (−Y) side portion is larger than the film thickness at the (+ Y) side portion. Then, after the film 93a of the organic EL material having the uneven thickness is formed in the application region 91a periodically (that is, every three pieces) and uneven application occurs, the product becomes a product. The display quality of the flat display device may be degraded.

  On the other hand, in the coating apparatus 1 according to the present embodiment, as described above, the concentration of the solvent component in the atmosphere is uniform around the three organic EL liquid lines applied by the three nozzles 17. Is improved. Further, the concentration of the solvent component of the organic EL liquid in the atmosphere on the (+ Y) side and the (−Y) side of the line of the organic EL liquid applied by the (−Y) side nozzle 17 among the three nozzles 17. The difference is reduced.

  Thereby, the uniformity of the drying rate of the organic EL liquid discharged from the discharge ports of the three nozzles 17 can be improved, and the relative movement direction of the substrate 9 in the (−Y) side (that is, the sub-scanning direction). The drying speed of the organic EL liquid discharged from the discharge port of the nozzle 17 on the rear side can be made substantially uniform in the sub-scanning direction. As a result, FIG. As shown in B, the cross-sections of the three films 93 of adjacent organic EL materials can be made substantially the same shape, and the occurrence of coating unevenness in the coating region 91 on the substrate 9 can be prevented.

  By the way, in the application | coating with respect to the board | substrate of the fluid material containing the pixel formation material for flat panel displays, when a coating nonuniformity generate | occur | produces, there exists a possibility that the display quality of the flat panel display after becoming a product may fall. Since the coating apparatus 1 according to the present embodiment can prevent the occurrence of uneven coating as described above, the coating apparatus 1 is particularly suitable for coating a fluid material containing a pixel forming material for a flat display device. It can be said that it is suitable.

  In the coating apparatus 1, an air flow parallel to the upper surface 90 of the substrate 9 is formed over the entire length of the coating area 91 in the main scanning direction, so that the line of the organic EL liquid applied by the coating head 14 is formed. In the full length, the air flow is maintained from the application of the organic EL liquid to the drying. Thereby, the uniformity of the drying speed of the organic EL liquid applied by the three nozzles 17 can be further improved over the entire length of the line of the organic EL liquid extending in the main scanning direction. Occurrence of coating unevenness in the coating region 91 can be prevented more reliably.

  In the coating apparatus 1, if the flow rate of air from the airflow forming unit 19 is too small, the solvent component in the atmosphere does not spread sufficiently to the (−Y) side, and if the flow rate is too large, the solvent component diffuses in a wide range. Since the density is greatly reduced, the amount of air sent from the airflow forming unit 19 is determined so that the air flow rate at the position of the nozzle 17 of the coating head 14 (that is, the coating position) in the sub-scanning direction is within an appropriate range. Has been. If the air flow forming unit moves relative to the coating head in the sub scanning direction (for example, the air flow forming unit is fixed on the substrate holding unit), the sub scanning between the air flow forming unit and the coating head is performed. It is necessary to change the amount of air sent from the airflow forming unit in accordance with the distance in the direction. On the other hand, in the coating apparatus 1, since the relative position in the sub-scanning direction of the airflow forming unit 19 with respect to the coating head 14 is fixed, there is no need to change the amount of air sent from the airflow forming unit 19. As a result, the apparatus configuration of the coating apparatus 1 can be simplified.

  In the air flow forming unit 19, air is sent from the delivery port 191 to form an air flow parallel to the upper surface 90 of the substrate 9, so that the air flow is formed on the substrate 9 by air suction or the like. Thus, an air flow having a desired direction and flow velocity can be easily formed. As a result, the structure of the coating apparatus 1 can be simplified. Further, the air flow can be more easily formed by sending air in parallel to the upper surface 90 of the substrate 9 from the outlet 191 disposed on the (+ Y) side of the plurality of nozzles 17 of the coating head 14. In addition, the structure of the coating apparatus 1 can be further simplified.

  In the airflow forming unit 19, since air is used as a gas that forms an airflow on the substrate 9, it is not necessary to provide an airtight structure around the substrate holding unit 11 and the coating apparatus 1. Further simplification can be achieved. Moreover, gas can also be easily supplied to the airflow formation part 19 using the existing facilities, such as a factory in which the coating device 1 is installed.

  In the coating apparatus 1, the organic EL liquid discharged from the discharge ports of the three nozzles 17 is increased by increasing the drying speed of the organic EL liquid applied to the application region 91 of the substrate 9 by the heater 111 that heats the substrate 9. The difference in drying speed can be further reduced. As a result, the uniformity of the drying speed of the organic EL liquid discharged from the three nozzles 17 can be further improved, and the occurrence of coating unevenness in the coating region 91 on the substrate 9 can be more reliably prevented. .

  Next, a coating apparatus according to the second embodiment of the present invention will be described. FIG. 6 is a longitudinal cross-sectional view showing the vicinity of the airflow forming unit 19 of the coating apparatus according to the second embodiment. As shown in FIG. 6, in the coating apparatus according to the second embodiment, a gas heating unit 192 that heats air toward the coating head 14 is provided inside the airflow forming unit 19. In the present embodiment, a rod-like heater extending in the x direction is used as the gas heating unit 192. Other configurations are the same as those of the coating apparatus 1 shown in FIGS. 1 to 3, and the same reference numerals are given in the following description.

  In the coating apparatus according to the second embodiment, as in the first embodiment, the (+ Y) side parallel to the upper surface 90 of the substrate 9 formed by the airflow forming unit 19 is directed in the (−Y) direction. The air flow improves the uniformity of the concentration of the solvent component in the atmosphere around the three organic EL liquid lines applied by the three nozzles 17. As a result, the uniformity of the drying rate of the organic EL liquid discharged from the discharge ports of the three nozzles 17 of the coating head 14 can be improved, and coating unevenness in the coating region 91 (see FIG. 1) on the substrate 9 can be improved. Can be prevented.

  In the coating apparatus according to the second embodiment, in particular, the air heated by the gas heating unit 192 is applied to the coating region 91 of the substrate 9 by forming an air flow parallel to the upper surface 90 of the substrate 9. The drying rate of the organic EL liquid can be increased. Thereby, the difference in the drying speed of the organic EL liquid discharged from the discharge ports of the three nozzles 17 can be further reduced. As a result, the drying speed of the organic EL liquid discharged from the three nozzles 17 can be reduced. Uniformity can be further improved.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible.

  In the coating apparatus according to the second embodiment, the gas heating unit 192 is not necessarily provided in the airflow forming unit 19, and is the (−Y) side of the airflow forming unit 19 and the nozzle of the coating head 14. 17 may be provided on the (+ Y) side independently of the airflow forming unit 19. In this case, the air sent from the airflow forming unit 19 is heated by passing near the gas heating unit 192, and an airflow parallel to the upper surface 90 of the substrate 9 is formed by the heated air.

  In the coating apparatus according to the above-described embodiment, the flow rate of air at the position of the nozzle 17 of the coating head 14 in the sub-scanning direction is not necessarily limited to the above-described range, and depends on the type of solvent of the organic EL liquid, the evaporation rate, and the like. The speed is set appropriately.

  The delivery port 191 of the airflow forming unit 19 does not necessarily have a slit shape extending over the entire length of the application region 91 in the main scanning direction. For example, a plurality of the outlets 191 arranged over the entire length of the application region 91 in the main scanning direction. May be provided in the airflow forming unit 19. Further, the delivery port 191 of the airflow forming unit 19 is not necessarily provided over the entire length of the application region 91 in the main scanning direction. For example, one outlet having a width in the main scanning direction approximately equal to the width of the application head 14 is used. An airflow forming portion having only a delivery port is provided on the (+ Y) side of the plurality of nozzles 17 so as to be movable in the main scanning direction, and is synchronized with the coating head 14 while sending air when coating the organic EL liquid. By moving in the scanning direction, an air flow parallel to the upper surface 90 of the substrate 9 may be formed between the coating head 14 and the substrate 9.

  In the coating apparatus according to the above-described embodiment, it is not always necessary to send air parallel to the upper surface 90 of the substrate 9 from the outlet 191 of the airflow forming unit 19. For example, it is disposed on the (+ Y) side of the coating head 14. The air is sent downward from the airflow forming part 19 (that is, in the (−Z) direction), and the main surface of the substrate 9 is changed by the air whose direction is changed by colliding with the main surface 90 of the substrate 9 or another structure. An airflow parallel to 90 may be formed.

In the coating apparatus, the gas delivered from the airflow forming unit 19 is not limited to air, and may be an inert gas such as nitrogen (N ₂ ), for example. Further, air slightly containing the solvent component of the organic EL liquid may be sent out to form a gas flow parallel to the upper surface 90 of the substrate 9.

  Further, in the coating apparatus, instead of the airflow forming unit 19 that sends out gas from the (+ Y) side of the coating head 14, the substrate 9 is disposed on the (−Y) side of the coating head 14 and sucks the surrounding atmosphere. An airflow forming unit that forms a gas flow may be provided thereon. In addition, an airflow forming unit that forms a gas flow on the substrate 9 by sucking the gas from the (−Y) side while sending the gas from the (+ Y) side of the coating head 14 may be provided.

  In the coating apparatus according to the above embodiment, instead of the movement of the substrate 9 and the substrate holding unit 11 by the substrate moving mechanism 12, the coating head 14 moves in the sub-scanning direction, whereby the coating head for the substrate 9 in the sub-scanning direction. A relative movement with respect to 14 may be performed. Further, instead of the movement of the coating head 14 by the head moving mechanism 15, the substrate 9 and the substrate holder 11 move in the main scanning direction, so that the coating head 14 moves relative to the substrate 9 in the main scanning direction. Also good.

  In the coating apparatus, three types of organic EL liquids each including three types of organic EL materials having different colors from red (R), green (G), and blue (B) are supplied from the three nozzles 17 of the coating head 14. It may be discharged simultaneously and applied to the substrate 9. In this case, in the coating head 14, the distance in the sub-scanning direction between the two adjacent nozzles 17 is made equal to the partition wall pitch. Further, in the coating head 14, the number of nozzles 17 that discharge the organic EL liquid is not necessarily limited to three, and two or four or more nozzles 17 may be provided in the coating head 14. Further, the organic EL liquid ejected from these nozzles 17 may be applied in a stripe pattern to the application region 91 where no partition is provided.

  By the way, in the line of the organic EL liquid continuously discharged onto the substrate 9, the organic EL material in the organic EL liquid is relatively easy to move in the main scanning direction. As shown in FIG. As shown in A, a difference in film thickness is likely to occur. Since the coating apparatus according to the above embodiment can improve the uniformity of the drying time of the organic EL liquid as described above, it is particularly suitable for an apparatus that continuously discharges the organic EL liquid and applies it to the substrate. However, the present invention can also be applied to an apparatus that intermittently discharges a fluid material and applies it onto a substrate, such as an inkjet method.

  In the coating apparatus according to the above embodiment, a fluid material containing a hole transport material may be applied to the substrate 9. Here, the “hole transport material” is a material that forms a hole transport layer of an organic EL display device, and the “hole transport layer” is a positive electrode that is formed into an organic EL layer formed of an organic EL material. It means not only a narrowly defined hole transport layer that transports holes, but also includes a hole injection layer that injects holes.

  The coating device can also be used when a plurality of organic EL display devices are manufactured from a single substrate (so-called multi-surface processing). Further, the coating device is not necessarily used only for coating a fluid material containing an organic EL material or a hole transport material for an organic EL display device. For example, a flat surface of a liquid crystal display device, a plasma display device, or the like. You may utilize when the fluidity | liquidity material containing other types of pixel formation materials, such as a coloring material and a fluorescent material, is apply | coated with respect to the board | substrate for display apparatuses.

  As described above, since the coating apparatus can prevent the occurrence of coating unevenness in the coating region 91 on the substrate 9, the flat display in which the coating unevenness is easily perceived as a deterioration in display quality when the product is manufactured. Although it is particularly suitable for application of a fluid material containing a pixel forming material for a device (in the above embodiment, an organic EL material for an organic EL display device), the application device can be a substrate or a semiconductor for a flat display device. It may be used to apply various types of flowable materials to various substrates such as substrates.

It is a top view which shows the coating device which concerns on 1st Embodiment. It is a front view of a coating device. It is a longitudinal cross-sectional view which shows the airflow formation part vicinity. It is a figure which shows the flow of application | coating of organic electroluminescent liquid. It is sectional drawing which shows the film | membrane of the organic EL material formed on the board | substrate with the coating device of the comparative example. It is sectional drawing which shows the film | membrane of the organic EL material formed on the board | substrate with the coating device which concerns on this Embodiment. It is a longitudinal cross-sectional view which shows the airflow formation part vicinity of the coating device which concerns on 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Application | coating apparatus 9 Substrate 11 Substrate holding | maintenance part 12 Substrate moving mechanism 14 Coating head 15 Head moving mechanism 19 Airflow formation part 90 Upper surface 91 Application | coating area | region 111 Heater 191 Outlet 192 Gas heating part S11-S18 step

Claims (9)

An application device for applying a flowable material to a substrate,
A substrate holder for holding the substrate;
A discharge mechanism for discharging a flowable material from a plurality of discharge ports arranged at equal intervals in a sub-scanning direction parallel to the main surface of the substrate toward a coating region on the main surface of the substrate;
The ejection mechanism moves relative to the substrate in a main scanning direction perpendicular to the sub-scanning direction and parallel to the main surface, and the substrate is ejected each time movement in the main scanning direction is performed. A moving mechanism that moves relative to the mechanism in the sub-scanning direction;
An airflow forming unit that forms a gas flow substantially parallel to the main surface of the substrate from the front side in the sub-scanning direction toward the rear side in the relative movement direction between the discharge mechanism and the substrate; ,
A coating apparatus comprising: The coating apparatus according to claim 1,
The coating apparatus according to claim 1, wherein the gas flow is formed over the entire length of the coating region in the main scanning direction by the air flow forming unit. The coating apparatus according to claim 1 or 2,
A coating apparatus, wherein a relative position of the air flow forming unit in the sub-scanning direction with respect to the discharge mechanism is fixed. The coating apparatus according to any one of claims 1 to 3,
The coating apparatus, wherein the gas is air. The coating apparatus according to any one of claims 1 to 4,
The coating apparatus according to claim 1, wherein the air flow forming unit includes a delivery port for delivering the gas. The coating apparatus according to claim 5,
The delivery port is disposed on the front side in the relative movement direction of the substrate with respect to the plurality of ejection ports of the ejection mechanism;
The coating apparatus, wherein the gas is delivered from the delivery port substantially parallel to the main surface of the substrate. The coating apparatus according to any one of claims 1 to 6,
A coating apparatus, further comprising a gas heating unit that heats the gas toward the discharge mechanism. A coating apparatus according to any one of claims 1 to 7,
The coating apparatus, wherein the substrate holding unit includes a substrate heating unit that heats the substrate. A coating apparatus according to any one of claims 1 to 8,
The coating apparatus, wherein the fluid material includes a pixel forming material for a flat display device.

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