JP2019194960A - Coating device, coating method and organic el display - Google Patents

Abstract

To provide an organic EL display optimized in the number of contact holes for an auxiliary electrode.SOLUTION: A coating device according to one aspect of the present disclosure comprises a substrate holding part, a discharge unit, and a moving mechanism. The discharge unit includes a plurality of heads in which a plurality of nozzles are arranged in a first direction. The moving mechanism moves the discharge unit and the substrate holding part relative to each other along a second direction intersecting a first direction. The substrate comprises: a plurality of pixel electrodes provided in correspondence with a plurality of sub-pixels; a bank covering the plurality of pixel electrodes and having a plurality of openings for exposing at least one pixel electrode; and a plurality of contact holes by which an electrode counter to the plurality of pixel electrodes is electrically connected with an auxiliary electrode. Each contact hole is provided for every two or more sub-pixels. The discharge unit discharges a liquid drop of an organic material from a nozzle toward each opening in the substrate held by the substrate holding part.SELECTED DRAWING: Figure 10

Description

  The present disclosure relates to a coating apparatus, a coating method, and an organic EL display.

  Organic EL displays using organic light emitting diodes (OLEDs) have the advantages of being thin and light, with low power consumption, and excellent response speed, viewing angle, and contrast ratio. . An organic light emitting diode is configured by sandwiching an organic EL layer including a light emitting layer between a pixel electrode and a counter electrode.

  Patent Document 1 discloses a technique for suppressing an increase in wiring resistance accompanying an increase in screen size of an organic EL display by connecting an auxiliary electrode formed of a material having a low resistivity with a counter electrode.

JP 2016-197240 A

  The present disclosure provides an organic EL display in which the number of contact holes for auxiliary electrodes is optimized.

  A coating apparatus according to an aspect of the present disclosure includes a substrate holding unit, a discharge unit, and a moving mechanism. The substrate holding unit holds the substrate. The discharge unit includes a plurality of heads provided with a plurality of nozzles arranged in the first direction. The moving mechanism relatively moves the discharge unit and the substrate holding unit along a second direction intersecting the first direction. The substrate includes a plurality of pixel electrodes provided corresponding to the plurality of sub-pixels, a bank that covers the plurality of pixel electrodes and that has a plurality of openings that expose at least one pixel electrode, and a plurality of pixel electrodes And a plurality of contact holes for electrically connecting the counter electrode opposed to the auxiliary electrode. A contact hole is provided for every two or more subpixels. The discharge unit discharges droplets of the organic material from the nozzle toward the opening of the substrate held by the substrate holding unit.

  According to the present disclosure, it is possible to provide an organic EL display in which the number of contact holes for auxiliary electrodes is optimized.

FIG. 1 is a schematic plan view showing a configuration example of an organic EL display in which contact holes for auxiliary electrodes are formed for each subpixel. FIG. 2 is a diagram illustrating an example of a circuit configuration of the organic EL display according to the embodiment. FIG. 3 is a schematic plan view of the organic EL display according to the embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a flowchart illustrating a method for manufacturing the organic light emitting diode according to the embodiment. FIG. 7 is a schematic plan view showing the configuration of the substrate processing system according to the embodiment. FIG. 8 is a schematic plan view showing the configuration of the coating apparatus according to the embodiment. FIG. 9 is a schematic side view showing the configuration of the coating apparatus according to the embodiment. FIG. 10 is a plan view showing a drawing pattern drawn by the coating apparatus according to the embodiment. FIG. 11 is a plan view illustrating a drawing pattern according to a first modification of the embodiment. FIG. 12 is a plan view illustrating a drawing pattern according to a second modification example of the embodiment. FIG. 13 is a plan view showing a drawing pattern according to a third modification of the embodiment.

  Hereinafter, modes for carrying out a coating apparatus, a coating method, and an organic EL display according to the present disclosure (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings. In addition, the coating device, the coating method, and the organic EL display according to the present disclosure are not limited by this embodiment. In addition, the embodiments can be appropriately combined within a range that does not contradict processing contents. In the following embodiments, the same portions are denoted by the same reference numerals, and redundant description is omitted.

  In addition, in each of the drawings referred to below, for easy understanding, an orthogonal coordinate system in which the X-axis direction, the Y-axis direction, and the Z-axis direction orthogonal to each other are defined and the Z-axis positive direction is the vertical upward direction is shown. There is a case.

  An organic EL display using an organic light emitting diode is advantageous in that it is thin and light and has low power consumption, and is excellent in terms of response speed, viewing angle, and contrast ratio. For this reason, the organic EL display attracts attention as a next-generation flat panel display (FPD) in recent years.

  An organic light emitting diode is configured by sandwiching an organic EL layer including a light emitting layer between a pixel electrode and a counter electrode, and an ink jet type coating apparatus is used to form the organic EL layer.

  In recent years, with the increase in the screen size of an organic EL display, the wiring length tends to become longer. As the wiring length becomes longer, the wiring resistance increases, which may make it difficult to supply power necessary for light emission to, for example, a pixel electrode located far from the power source.

  Therefore, as a technique for reducing the wiring resistance, a technique for connecting an auxiliary electrode made of a material having a low resistivity with a counter electrode has been proposed. In this technique, a contact hole for conduction of the auxiliary electrode is formed for each subpixel. A subpixel is a point of each of R (red), G (green), and B (blue) constituting one pixel. That is, in the above technique, one contact hole is formed in each of the red subpixel, the green subpixel, and the blue subpixel.

  FIG. 1 is a schematic plan view showing a configuration example of an organic EL display in which contact holes for auxiliary electrodes are formed for each subpixel. As shown in FIG. 1, the organic EL display 1X includes a plurality of pixel electrodes 21X and a bank 30X that covers the plurality of pixel electrodes 21X. In the bank 30X, an opening 31X that exposes a part of the pixel electrode 21X is formed for each pixel electrode 21X. That is, one opening 31X is formed for one pixel electrode 21X.

  An organic EL layer 23X is formed in each opening 31X. The organic EL layer 23X is formed by discharging droplets of an organic material to each opening 31X by an inkjet method.

  A counter electrode (not shown) is disposed on the organic EL layer 23X. The counter electrode is common to the plurality of pixel electrodes 21X and faces the plurality of pixel electrodes 21X. Thus, one subpixel is formed by sandwiching the organic EL layer 23X between the pixel electrode 21X and the counter electrode. Therefore, a region where the pixel electrode 21X and the opening 31X overlap in plan view corresponds to a region of one subpixel.

  The auxiliary electrode contact hole 50X is formed for each sub-pixel. In other words, in the organic EL display 1X, one contact hole 50X is formed for one pixel electrode 21X or one opening 31X.

  Incidentally, in recent years, in order to increase the pixel density of the organic EL display, the size of the sub-pixel tends to be reduced. Normally, an opening for receiving a droplet of an organic material is formed in each bank for each sub-pixel (see FIG. 1). For this reason, when the size of the opening is reduced as the size of the sub-pixel is reduced, the tolerance of the landing position of the droplet is reduced, so that the droplet easily protrudes from the opening.

  Therefore, in order to alleviate the tolerance of the droplet landing position, a technique for forming an opening for landing a droplet not for each subpixel but for each of a plurality of adjacent subpixels of the same color (hereinafter referred to as “pixel connection”). Is proposed).

  However, it is difficult to connect pixels in the organic EL display 1X in which the auxiliary electrode contact hole 50X is provided for each sub-pixel. That is, as shown in FIG. 1, each contact hole 50X is formed in a region between two adjacent organic EL layers 23X having the same color. For this reason, if one opening for connecting two adjacent organic EL layers 23X of the same color shown in FIG. 1 is formed, the upper contact hole 50X in the two contact holes 50X shown in FIG. Will be located. Then, the organic material discharged into the opening flows into the contact hole 50X, so that the function of electrically connecting the counter electrode and the auxiliary electrode cannot be achieved. In addition, when the organic material flows into the contact hole 50X, the film thickness uniformity of the organic EL layer 23X may be reduced.

  Therefore, it is expected to provide an organic EL display in which the number of contact holes for auxiliary electrodes is optimized.

<Organic EL display>
FIG. 2 is a diagram illustrating an example of a circuit configuration of the organic EL display according to the embodiment. In FIG. 2, one unit circuit 11 is shown enlarged.

  As shown in FIG. 2, the organic EL display 1 includes a substrate 10, a plurality of unit circuits 11, a scanning line driving circuit 14, and a data line driving circuit 15. The plurality of unit circuits 11, the scanning line driving circuit 14, and the data line driving circuit 15 are provided on the substrate 10.

  The unit circuit 11 is provided in a region surrounded by a plurality of scanning lines 16 connected to the scanning line driving circuit 14 and a plurality of data lines 17 connected to the data line driving circuit 15. The unit circuit 11 includes a TFT layer 12 and an organic light emitting diode 13.

  The TFT layer 12 has a plurality of TFTs (Thin Film Transistors). Of the plurality of TFTs, one TFT has a function as a switching element, and the other TFT has a function as a current control element for controlling the amount of current flowing through the organic light emitting diode 13. The TFT layer 12 is operated by the scanning line driving circuit 14 and the data line driving circuit 15, and supplies current to the organic light emitting diode 13. The TFT layer 12 is provided for each unit circuit 11, and the plurality of unit circuits 11 are controlled independently.

  The TFT layer 12 may have a general configuration, and is not limited to the configuration shown in FIG. Moreover, although embodiment demonstrates the example in case the drive system of the organic electroluminescent display 1 is an active matrix system, a passive matrix system may be sufficient as a drive system.

  FIG. 3 is a schematic plan view of the organic EL display 1 according to the embodiment. In FIG. 3, a cathode 22 described later is omitted. Moreover, in FIG. 3, the area | region where the light emitting layer 26 of the same color is formed is shown with the same hatching.

  As shown in FIG. 3, in the organic EL display 1 according to the embodiment, one opening 31 is formed for every two subpixels. Specifically, in the organic EL display 1 according to the embodiment, the opening 31 of the bank 30 exposes two anodes 21 provided corresponding to two adjacent sub-pixels of the same color. Here, a plurality of sub-pixels of the same color are arranged along the Y-axis direction, and the opening 31 exposes a part of each of the two anodes 21 adjacent in the Y-axis direction.

  As described above, the openings 31 for landing the droplets of the organic material for forming the organic EL layer 23 are formed not for each subpixel but for each of the two adjacent subpixels of the same color. The tolerance of landing position can be relaxed.

  4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIG. 4, in the organic EL display 1, a TFT layer 12 is formed on a substrate 10, and a flattening layer 18 that flattens a step formed by the TFT layer 12 is formed on the TFT layer 12. It is formed. The substrate 10 is a transparent substrate such as a glass substrate or a resin substrate.

  The planarization layer 18 has an insulating property. Contact plugs 19 are formed in contact holes that penetrate the planarization layer 18. The contact plug 19 electrically connects the anode 21 as a pixel electrode formed on the flat surface of the flattening layer 18 and the TFT layer 12. The contact plug 19 may be formed of the same material as the anode 21 at the same time.

  The organic light emitting diode 13 is formed on the flat surface of the flattening layer 18. The organic light emitting diode 13 includes an anode 21 as a pixel electrode, a cathode 22 as a counter electrode provided on the opposite side of the substrate 10 with respect to the pixel electrode, and an organic EL formed between the anode 21 and the cathode 22. Layer 23. By operating the TFT layer 12, a voltage is applied between the anode 21 and the cathode 22, and the organic EL layer 23 emits light.

  The anode 21 as the pixel electrode is formed of, for example, ITO (Indium Tin Oxide) or the like, and transmits light from the organic EL layer 23. The light that has passed through the anode 21 is taken out by passing through the substrate 10. The anode 21 is provided for each unit circuit 11, in other words, for each subpixel.

  The cathode 22 as the counter electrode is formed of, for example, aluminum, and reflects light from the organic EL layer 23 toward the organic EL layer 23. The light reflected by the cathode 22 is taken out by passing through the organic EL layer 23, the anode 21, and the substrate 10. The cathode 22 is common to the plurality of unit circuits 11.

  Although an example in which the anode 21 is a pixel electrode and the cathode 22 is a counter electrode will be described here, the cathode 22 may be a pixel electrode and the anode 21 may be a counter electrode.

  The organic EL layer 23 includes, for example, a hole injection layer 24, a hole transport layer 25, a light emitting layer 26, an electron transport layer 27, and an electron injection layer 28. The hole injection layer 24, the hole transport layer 25, the light emitting layer 26, the electron transport layer 27, and the electron injection layer 28 are laminated in this order from the anode 21 side to the cathode 22 side.

  When a voltage is applied between the anode 21 and the cathode 22, holes are injected from the anode 21 into the hole injection layer 24, and electrons are injected from the cathode 22 into the electron injection layer 28. The holes injected into the hole injection layer 24 are transported to the light emitting layer 26 by the hole transport layer 25. The electrons injected into the electron injection layer 28 are transported to the light emitting layer 26 by the electron transport layer 27. Then, holes and electrons are recombined in the light emitting layer 26, the light emitting material of the light emitting layer 26 is excited, and the light emitting layer 26 emits light.

  As the light emitting layer 26, for example, as shown in FIG. 3, a red light emitting layer 26R, a green light emitting layer 26G, and a blue light emitting layer 26B are formed. The red light emitting layer 26R is formed of a red light emitting material that emits red light. The green light emitting layer 26G is formed of a green light emitting material that emits green light. The blue light emitting layer 26B is formed of a blue light emitting material that emits blue light.

  One pixel in the organic EL display 1 has a sub-pixel having a red light-emitting layer 26R, a sub-pixel adjacent to the sub-pixel and having a blue light-emitting layer 26B, and a green light-emitting layer 26G adjacent to the sub-pixel. And a sub-pixel. The red light emitting layer 26R, the green light emitting layer 26G, and the blue light emitting layer 26B emit light in a region where the anode 21 as the pixel electrode and the cathode 22 as the counter electrode overlap in plan view.

  The bank 30 separates the coating solution for the red light emitting layer 26R, the coating solution for the green light emitting layer 26G, and the coating solution for the blue light emitting layer 26B, thereby preventing mixing of these coating solutions. The bank 30 has an insulating property and fills a contact hole that penetrates the planarization layer 18.

  As shown in FIG. 3, in the organic EL display 1 according to the embodiment, one contact hole 50 is formed for one opening 31. In other words, the contact hole 50 is provided for each of the two anodes 21 of the same color corresponding to the two anodes 21 exposed by the opening 31.

  5 is a cross-sectional view taken along line VV in FIG. As shown in FIG. 5, the contact hole 50 is formed so as to penetrate the bank 30 and the planarization layer 18. The contact hole 50 is opened on the upper surface of the bank 30 and exposes a part of the auxiliary electrode 51 provided on the substrate 10.

  The contact hole 50 is filled with a conductive material such as W (tungsten). Thereby, the cathode 22 and the auxiliary electrode 51 can be electrically connected.

  As shown in FIG. 3, the contact hole 50 is formed in a region between one opening 31 among the plurality of openings 31 and another opening 31 adjacent to the one opening 31 in the Y-axis direction. Is done. In other words, the contact hole 50 is formed in a region between two openings 31 adjacent in the Y-axis direction where the light emitting layer 26 of the same color is formed. For this reason, the organic material can be made difficult to enter the contact hole 50 during the coating process.

  As described above, the auxiliary electrode contact hole 50 is provided for each of the two anodes 21 of the same color corresponding to the two anodes 21 exposed by the opening 31. Accordingly, the contact hole 50 does not get in the way of pixel connection. Therefore, it is possible to apply pixel connection even to a large organic EL display that requires an auxiliary electrode. As described above, the cathode 22 as the counter electrode is common to the plurality of unit circuits 11, and the contact hole 50 is not necessarily provided for each subpixel.

  Here, one contact hole 50 is provided for every two sub-pixels. However, one contact hole 50 for every three or more sub-pixels, for example, depending on the area of the anode 21 and the thickness of the wiring. It is also possible to provide.

<Method for manufacturing organic light-emitting diode>
FIG. 6 is a flowchart illustrating a method for manufacturing the organic light emitting diode 13 according to the embodiment. Each processing procedure shown in FIG. 6 includes a TFT layer 12, an auxiliary electrode 51, a planarization layer 18, a bank 30, an opening 31 and a contact hole 50 formed on the substrate 10, and a conductive material in the contact hole 50. This is performed on the organic EL display after embedded.

  First, in step S101, the anode 21 as a pixel electrode is formed. For forming the anode 21, for example, a vapor deposition method is used. The anode 21 is formed for each unit circuit 11 with respect to the flat surface of the flattening layer 18. A contact plug 19 may be formed together with the anode 21.

  Subsequently, in step S102, the bank 30 is formed. The bank 30 is formed using, for example, a photoresist, and is patterned into a predetermined pattern by a photolithography process. A part of the anode 21 is exposed at the opening 31 of the bank 30.

  Subsequently, in step S103, the hole injection layer 24 is formed. An ink jet method is used to form the hole injection layer 24. The coating layer is formed by coating the coating liquid for the hole injection layer 24 on the anode 21 by the inkjet method. Then, the hole injection layer 24 shown in FIG. 4 is formed by drying and baking the coating layer.

  Subsequently, in step S104, the hole transport layer 25 is formed. As with the formation of the hole injection layer 24, the inkjet method is used to form the hole transport layer 25. A coating layer is formed by coating a coating solution for the hole transport layer 25 on the hole injection layer 24 by an inkjet method. Then, the positive hole transport layer 25 is formed by drying and baking the coating layer.

  Subsequently, in step S105, the light emitting layer 26 is formed. In the formation of the light emitting layer 26, an inkjet method is used as in the formation of the hole injection layer 24 and the hole transport layer 25. A coating layer is formed by coating a coating solution for the light emitting layer 26 on the hole transport layer 25 by an inkjet method. Then, the light emitting layer 26 is formed by drying and baking the coating layer. As described above, as the light emitting layer 26, for example, the red light emitting layer 26R, the green light emitting layer 26G, and the blue light emitting layer 26B are formed.

  Subsequently, in step S106, the electron transport layer 27 is formed. For example, vapor deposition is used to form the electron transport layer 27. Since the electron transport layer 27 may be common to the plurality of unit circuits 11, it may be formed not only on the light emitting layer 26 in the opening 31 of the bank 30 but also on the bank 30.

  Subsequently, in step S107, the electron injection layer 28 is formed. For example, vapor deposition is used to form the electron injection layer 28. The electron injection layer 28 is formed on the electron transport layer 27. Similar to the electron transport layer 27, the electron injection layer 28 may be common to the plurality of unit circuits 11.

  Subsequently, in step S108, the cathode 22 is formed. For example, vapor deposition is used to form the cathode 22. The cathode 22 is formed on the electron injection layer 28. The cathode 22 is common to the plurality of unit circuits 11. When the driving method of the organic EL display 1 is a passive matrix method, the cathode 22 is patterned into a predetermined pattern.

  Through the above steps, the organic light emitting diode 13 is manufactured. In the organic EL layer 23, a substrate processing system is used to form the hole injection layer 24, the hole transport layer 25, and the light emitting layer 26.

<Substrate processing system>
FIG. 7 is a schematic plan view showing the configuration of the substrate processing system according to the embodiment. The substrate processing system 100 illustrated in FIG. 7 forms the hole injection layer 24, the hole transport layer 25, and the light emitting layer 26 on the anode 21 by performing each process corresponding to steps S <b> 103 to S <b> 105 in FIG. 6.

  The substrate processing system 100 shown in FIG. 7 includes a carry-in station 110, a processing station 120, a carry-out station 130, and a control device 140.

  The carry-in station 110 carries in the cassette C that accommodates the plurality of substrates 10 from the outside, and sequentially takes out the plurality of substrates 10 from the cassette C. In each substrate 10, a TFT layer 12, a planarizing layer 18, an anode 21, a bank 30, an opening 31 and a contact hole 50 are formed in advance.

  The carry-in station 110 includes a cassette mounting table 111 on which the cassette C is mounted, a transfer path 112 provided between the cassette mounting table 111 and the processing station 120, and a substrate transfer body 113 provided on the transfer path 112. The substrate transport body 113 transports the substrate 10 between the cassette C mounted on the cassette mounting table 111 and the processing station 120.

  The processing station 120 forms the hole injection layer 24, the hole transport layer 25, and the light emitting layer 26 on the anode 21. The processing station 120 includes a hole injection layer forming block 121 that forms the hole injection layer 24, a hole transport layer forming block 122 that forms the hole transport layer 25, and a light emitting layer forming block 123 that forms the light emitting layer 26. Is provided.

  The hole injection layer forming block 121 forms a hole injection layer 24 by applying a coating liquid for the hole injection layer 24 on the anode 21 to form a coating layer, and drying and baking the coating layer. To do. The coating liquid for the hole injection layer 24 includes an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

  The hole injection layer forming block 121 includes a coating device 121a, a buffer device 121b, a vacuum drying device 121c, a heat treatment device 121d, and a temperature control device 121e. The coating device 121 a ejects droplets of the coating liquid for the hole injection layer 24 toward the opening 31 of the bank 30. The buffer device 121b temporarily accommodates the substrate 10 waiting to be processed. The vacuum drying device 121c drys the coating layer applied by the coating device 121a under reduced pressure, and removes the solvent contained in the coating layer. The heat treatment apparatus 121d heat-treats the coating layer dried by the reduced pressure drying apparatus 121c. The temperature adjustment device 121e adjusts the temperature of the substrate 10 heat-treated by the heat treatment device 121d to a predetermined temperature, for example, room temperature.

  The inside of the coating device 121a, the buffer device 121b, the heat treatment device 121d, and the temperature adjustment device 121e is maintained in an air atmosphere. The reduced pressure drying apparatus 121c switches the internal atmosphere between an air atmosphere and a reduced pressure atmosphere.

  In the hole injection layer forming block 121, the arrangement, number, and internal atmosphere of the coating device 121a, the buffer device 121b, the reduced pressure drying device 121c, the heat treatment device 121d, and the temperature control device 121e can be arbitrarily selected.

  The hole injection layer forming block 121 includes substrate transfer devices CR1 to CR3 and delivery devices TR1 to TR3. The board | substrate conveyance apparatuses CR1-CR3 each convey the board | substrate 10 to each adjacent apparatus. For example, the substrate transport device CR1 transports the substrate 10 to the adjacent coating device 121a and buffer device 121b. The substrate transport device CR2 transports the substrate 10 to the adjacent reduced pressure drying device 121c. The substrate transfer device CR3 transfers the substrate 10 to the adjacent heat treatment device 121d and the temperature adjustment device 121e. The delivery devices TR1 to TR3 are sequentially provided between the carry-in station 110 and the substrate transfer device CR1, between the substrate transfer device CR1 and the substrate transfer device CR2, and between the substrate transfer device CR2 and the substrate transfer device CR3. The substrate 10 is relayed between them. The insides of the substrate transfer devices CR1 to CR3 and the delivery devices TR1 to TR3 are maintained in an air atmosphere.

  Between the substrate transport device CR3 of the hole injection layer forming block 121 and the substrate transport device CR4 of the hole transport layer forming block 122, a delivery device TR4 that relays the substrate 10 between them is provided. The interior of the delivery device TR4 is maintained in an air atmosphere.

  The hole transport layer forming block 122 is formed by applying a coating liquid for the hole transport layer 25 onto the hole injection layer 24 to form a coating layer, and drying and firing the coating layer. 25 is formed. The coating liquid for the hole transport layer 25 includes an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

  The hole transport layer forming block 122 includes a coating device 122a, a buffer device 122b, a vacuum drying device 122c, a heat treatment device 122d, and a temperature control device 122e. The coating device 122 a discharges droplets of the coating liquid for the hole transport layer 25 toward the opening 31 of the bank 30. The buffer device 122b temporarily accommodates the substrate 10 waiting to be processed. The vacuum drying device 122c drys the coating layer applied by the coating device 122a under reduced pressure, and removes the solvent contained in the coating layer. The heat treatment apparatus 122d heat-treats the coating layer dried by the reduced pressure drying apparatus 122c. The temperature adjustment device 122e adjusts the temperature of the substrate 10 heat-treated by the heat treatment device 122d to a predetermined temperature, for example, room temperature.

  The inside of the coating device 122a and the buffer device 122b is maintained in an air atmosphere. On the other hand, in order to suppress deterioration of the organic material of the hole transport layer 25, the heat treatment device 122d and the temperature control device 122e are maintained in an atmosphere having a low oxygen and low dew point. The reduced pressure drying device 122c switches the internal atmosphere between a low oxygen and low dew point atmosphere and a reduced pressure atmosphere.

  Here, the low oxygen atmosphere refers to an atmosphere having an oxygen concentration lower than that of the air, for example, an atmosphere having an oxygen concentration of 10 ppm or less. The low dew point atmosphere refers to an atmosphere having a dew point temperature lower than that of the air, for example, an atmosphere having a dew point temperature of −10 ° C. or lower. The atmosphere of low oxygen and low dew point is formed with an inert gas such as nitrogen gas, for example.

  In the hole transport layer forming block 122, the arrangement and number of the coating device 122a, the buffer device 122b, the reduced pressure drying device 122c, the heat treatment device 122d, and the temperature control device 122e can be arbitrarily selected.

  The hole transport layer forming block 122 includes substrate transport devices CR4 to CR6 and delivery devices TR5 to TR6. The substrate transfer devices CR4 to CR6 transfer the substrate 10 to each adjacent device. The delivery devices TR5 to TR6 are provided in order between the substrate transport device CR4 and the substrate transport device CR5 and between the substrate transport device CR5 and the substrate transport device CR6, respectively, and relay the substrate 10 between them.

  The inside of the substrate transfer device CR4 is maintained in an air atmosphere. On the other hand, the inside of the substrate transfer apparatuses CR5 to CR6 is maintained in an atmosphere of low oxygen and low dew point. This is because the inside of the reduced pressure drying device 122c adjacent to the substrate transfer device CR5 can be switched between an atmosphere of low oxygen and low dew point and a reduced pressure atmosphere. Another reason is that the interior of the heat treatment apparatus 122d and the temperature adjustment apparatus 122e adjacent to the substrate transfer apparatus CR6 is maintained in a low oxygen and low dew point atmosphere.

  The delivery device TR5 is configured as a load lock device that switches the atmosphere inside thereof between an air atmosphere and a low oxygen and low dew point atmosphere. This is because the reduced pressure drying device 122c is provided adjacent to the downstream side of the delivery device TR5. On the other hand, the interior of the delivery device TR6 is maintained in an atmosphere of low oxygen and low dew point.

  Between the substrate transport device CR6 of the hole transport layer forming block 122 and the substrate transport device CR7 of the light emitting layer forming block 123, a delivery device TR7 that relays the substrate 10 between them is provided. The inside of the substrate transfer device CR6 is maintained in an atmosphere of low oxygen and low dew point, and the inside of the substrate transfer device CR7 is maintained in an air atmosphere. Therefore, the delivery device TR7 is configured as a load lock device that switches the internal atmosphere between a low oxygen and low dew point atmosphere and an air atmosphere.

  The light emitting layer formation block 123 forms the light emitting layer 26 by apply | coating the coating liquid for light emitting layers 26 on the positive hole transport layer 25, forming a coating layer, and drying and baking the formed coating layer. The coating solution for the light emitting layer 26 includes an organic material and a solvent. The organic material may be either a polymer or a monomer. In the case of a monomer, it may be polymerized by baking to form a polymer.

  The light emitting layer forming block 123 includes a coating device 123a, a buffer device 123b, a reduced pressure drying device 123c, a heat treatment device 123d, and a temperature adjusting device 123e. The coating device 123 a ejects droplets of the coating liquid for the light emitting layer 26 toward the opening 31 of the bank 30. The buffer device 123b temporarily accommodates the substrate 10 waiting to be processed. The vacuum drying device 123c drys the coating layer applied by the coating device 123a under reduced pressure, and removes the solvent contained in the coating layer. The heat treatment apparatus 123d heat-treats the coating layer dried by the reduced pressure drying apparatus 123c. The temperature adjustment device 123e adjusts the temperature of the substrate 10 heat-treated by the heat treatment device 123d to a predetermined temperature, for example, room temperature.

  The inside of the coating device 123a and the buffer device 123b is maintained in an air atmosphere. On the other hand, the heat treatment device 123d and the temperature control device 123e are maintained in an atmosphere having a low oxygen and low dew point in order to suppress deterioration of the organic material of the light emitting layer 26. The reduced pressure drying device 123c switches the internal atmosphere between a low oxygen and low dew point atmosphere and a reduced pressure atmosphere.

  In the light emitting layer forming block 123, the arrangement and number of the coating device 123a, the buffer device 123b, the reduced-pressure drying device 123c, the heat treatment device 123d, and the temperature control device 123e can be arbitrarily selected.

  The light emitting layer forming block 123 includes substrate transfer devices CR7 to CR9 and delivery devices TR8 to TR9. The substrate transfer devices CR7 to CR9 transfer the substrate 10 to each adjacent device. The delivery devices TR8 to TR9 are provided in order between the substrate transport device CR7 and the substrate transport device CR8 and between the substrate transport device CR8 and the substrate transport device CR9, respectively, and relay the substrate 10 between them.

  The inside of the substrate transfer device CR7 is maintained in an air atmosphere. On the other hand, the inside of the substrate transfer apparatuses CR8 to CR9 is maintained in an atmosphere of low oxygen and low dew point. This is because the inside of the reduced pressure drying device 123c adjacent to the substrate transfer device CR8 can be switched between an atmosphere of low oxygen and low dew point and a reduced pressure atmosphere. Another reason is that the interior of the heat treatment device 123d and the temperature adjustment device 123e adjacent to the substrate transfer device CR9 is maintained in a low oxygen and low dew point atmosphere.

  The delivery device TR8 is configured as a load lock device that switches the internal atmosphere between an air atmosphere and a low oxygen and low dew point atmosphere. This is because the reduced pressure drying device 123c is provided adjacent to the downstream side of the delivery device TR8. The interior of the delivery device TR9 is maintained in an atmosphere of low oxygen and low dew point.

  Between the substrate transport device CR9 of the light emitting layer forming block 123 and the carry-out station 130, a delivery device TR10 that relays the substrate 10 between them is provided. The inside of the substrate transfer device CR9 is maintained in an atmosphere of low oxygen and low dew point, and the inside of the carry-out station 130 is maintained in an air atmosphere. Therefore, the delivery device TR7 is configured as a load lock device that switches the internal atmosphere between a low oxygen and low dew point atmosphere and an air atmosphere.

  The unloading station 130 sequentially stores the plurality of substrates 10 in the cassette C, and unloads the cassette C to the outside. The carry-out station 130 includes a cassette mounting table 131 on which the cassette C is mounted, a transfer path 132 provided between the cassette mounting table 131 and the processing station 120, and a substrate transfer body 133 provided on the transfer path 132. The substrate transport body 133 transports the substrate 10 between the processing station 120 and the cassette C mounted on the cassette mounting table 131.

  The control device 140 includes a control unit 141 and a storage unit 142. The control device 140 includes, for example, a computer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), an input / output port, and various circuits.

  The CPU of the computer reads and executes a program stored in the ROM, for example. Thereby, the CPU of the computer functions as the control unit 141. Part or all of the control unit 141 may be configured by hardware. The hard wafer is, for example, an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

  The storage unit 142 corresponds to, for example, a RAM or an HDD. Note that the control device 140 may acquire the above-described program and various types of information via another computer or a portable storage medium connected via a wired or wireless network. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

  Next, a substrate processing method using the substrate processing system 100 will be described. When the cassette C containing a plurality of substrates 10 is placed on the cassette mounting table 111, the substrate carrier 113 sequentially takes out the substrates 10 from the cassette C on the cassette mounting table 111, and the hole injection layer forming block 121. Transport to.

  The hole injection layer forming block 121 forms a coating layer by applying a coating solution for the hole injection layer 24 on the anode 21, and drying and baking the formed coating layer, thereby forming the hole injection layer 24. Form. The substrate 10 on which the hole injection layer 24 is formed is delivered from the hole injection layer formation block 121 to the hole transport layer formation block 122 by the delivery device TR4.

  The hole transport layer forming block 122 forms a coating layer by applying a coating liquid for the hole transport layer 25 onto the hole injection layer 24, and drying and baking the formed coating layer, thereby transporting holes. Layer 25 is formed. The substrate 10 on which the hole transport layer 25 is formed is delivered from the hole transport layer formation block 122 to the light emitting layer formation block 123 by the delivery device TR7.

  The light emitting layer formation block 123 forms the light emitting layer 26 by apply | coating the coating liquid for light emitting layers 26 on the positive hole transport layer 25, forming a coating layer, and drying and baking the formed coating layer. The substrate 10 on which the light emitting layer 26 is formed is delivered from the light emitting layer forming block 123 to the carry-out station 130 by the delivery device TR10.

  The substrate carrier 133 of the carry-out station 130 stores the substrate 10 received from the delivery device TR10 in a predetermined cassette C on the cassette mounting table 131. Thereby, a series of processing of the substrate 10 in the substrate processing system 100 is completed.

  The substrate 10 is unloaded from the unloading station 130 while being stored in the cassette C. An electron transport layer 27, an electron injection layer 28, a cathode 22 and the like are formed on the substrate 10 carried out to the outside.

<Coating apparatus and coating method>
Next, the coating device 123a of the light emitting layer forming block 123 will be described with reference to FIGS. FIG. 8 is a schematic plan view showing the configuration of the coating apparatus 123a according to the embodiment. FIG. 9 is a schematic side view showing the configuration of the coating apparatus 123a according to the embodiment.

  8 and 9, the Y-axis direction is a line direction in which a plurality of nozzles that discharge droplets of the same coating liquid are arranged, and the X-axis direction is a scan direction orthogonal to the Y-axis direction. It should be noted that the line direction and the scan direction need only cross each other and do not have to be orthogonal.

  As shown in FIGS. 8 and 9, the coating apparatus 123 a includes, for example, a stage 150 that holds and moves the substrate 10, a discharge unit 160 that discharges droplets toward the substrate 10, and functions of the discharge unit 160. A maintenance unit 170 for maintenance.

  The stage 150 and the maintenance unit 170 are provided side by side in the Y-axis direction. A Y-axis guide 180 is bridged between the upper side of the stage 150 and the upper side of the maintenance unit 170. The discharge unit 160 is movable in the Y axis direction along the Y axis guide 180. A linear motor or the like is used as a drive unit that moves the discharge unit 160 in the Y-axis direction.

  The stage 150 includes a substrate holding unit 151 that holds the substrate 10 horizontally and a moving mechanism 152 that moves the substrate holding unit 151. The substrate holding unit 151 holds the substrate 10 with the application surface on which the droplets of the substrate 10 are applied facing upward. For example, a vacuum chuck is used as the substrate holding unit 151, but an electrostatic chuck or the like may be used. The moving mechanism 152 includes an X-axis direction driving unit 153 that moves the substrate holding unit 151 in the X-axis direction, a Y-axis direction driving unit 154 that moves the substrate holding unit 151 in the Y-axis direction, and the substrate holding unit 151 around the Z-axis. And a rotation driving unit 155 for rotating the motor.

  The discharge unit 160 is movable between a position for discharging droplets toward the substrate 10 above the stage 150 and a position for receiving processing for maintaining functions by the maintenance unit 170. A plurality of (here, ten) discharge units 160 are arranged in the Y-axis direction. The plurality of discharge units 160 may be moved independently in the Y-axis direction, or may be moved integrally in the Y-axis direction.

  Each discharge unit 160 includes a carriage 161 and a plurality of heads 162 provided on the lower surface of the carriage 161. Each head 162 is provided with at least one nozzle row composed of a plurality of nozzles 163 arranged in the Y-axis direction. A plurality of nozzles 163 provided in the same head 162 ejects droplets of the same coating liquid. A nozzle 163 that ejects droplets of the coating liquid for the red light emitting layer 26R, a nozzle 163 that ejects droplets of the coating liquid for the green light emitting layer 26G, and a droplet of coating liquid for the blue light emitting layer 26B are ejected. The nozzle 163 is provided in a separate head 162.

  The maintenance unit 170 performs a process for maintaining the function of the discharge unit 160 and eliminates the discharge failure of the discharge unit 160. The maintenance unit 170 includes a wiping unit 171 that wipes the periphery of the nozzle outlet and a suction unit 172 that sucks droplets from the nozzle outlet. The suction unit 172 also plays a role of blocking clogging due to drying by closing the ejection port of the nozzle in the resting state.

  Next, a coating method using the coating apparatus 123a having the above configuration will be described. The following operation of the coating device 123a is controlled by the control device 140. In FIG. 7, the control device 140 is provided separately from the coating device 123a, but may be provided as a part of the coating device 123a.

  First, when the substrate 10 carried into the inside from the outside of the coating apparatus 123 a is placed on the substrate holding unit 151, the substrate holding unit 151 holds the substrate 10. Subsequently, the position correction of the substrate holding unit 151 by the moving mechanism 152 is performed based on the image obtained by imaging the alignment mark of the substrate 10. Thereafter, the moving mechanism 152 moves the substrate holder 151 in the X-axis direction and passes under the discharge unit 160. Meanwhile, the discharge unit 160 discharges a droplet of the coating liquid toward the substrate 10. Thereafter, the moving mechanism 152 changes the position of the substrate holding unit 151 in the Y-axis direction, moves the substrate holding unit 151 in the X-axis direction again, and passes under the discharge unit 160. Meanwhile, the discharge unit 160 discharges a droplet of the coating liquid toward the substrate 10. By repeating this, the coating apparatus 123 a draws a predetermined pattern on the substrate 10.

  The substrate 10 for which drawing has been completed is removed from the substrate holding portion 151 and carried out from the inside of the coating apparatus 123a to the outside. Subsequently, the next substrate 10 is carried into the coating apparatus 123 a from the outside, and the coating apparatus 123 a draws a predetermined pattern on the substrate 10. Note that the process of maintaining the function of the discharge unit 160 by the maintenance unit 170 is appropriately performed, for example, between the replacement of the substrate 10.

  The coating apparatus 123a may move the discharge unit 160 that discharges the liquid droplets toward the substrate 10, or may move both the substrate holding unit 151 and the discharge unit 160. That is, the coating device 123a only needs to be able to move the substrate holding unit 151 and the discharge unit 160 relatively.

<Drawing pattern drawn by coating device>
Next, a drawing pattern drawn by the coating apparatus 123a will be described with reference to FIG. FIG. 10 is a plan view showing a drawing pattern drawn by the coating apparatus 123a according to the embodiment.

  As shown in FIG. 10, the organic EL display 1 has, for example, a red light emitting region 261R, a green light emitting region 261G, and a blue light emitting region 261B for each pixel.

  The red light emitting region 261R corresponds to a region sandwiched between the anode 21 and the cathode 22 in the organic EL layer 23 having the red light emitting layer 26R. The green light emitting region 261G corresponds to a region sandwiched between the anode 21 and the cathode 22 in the organic EL layer 23 having the green light emitting layer 26G. The blue light emitting region 261B corresponds to a region sandwiched between the anode 21 and the cathode 22 in the organic EL layer 23 having the blue light emitting layer 26B. Each light emitting region 261R, 261G, 261B emits light independently for each anode 21, and the amount of light emission is adjusted by the voltage between the anode 21 and the cathode 22.

  The red light emitting region 261R, the green light emitting region 261G, and the blue light emitting region 261B are repeatedly arranged at intervals in this order along the X-axis direction, thereby forming a light emitting region group 262. In the organic EL display 1, the plurality of light emitting region groups 262 are arranged at intervals in the Y-axis direction. Therefore, the organic EL display 1 has a plurality of light emitting regions that emit light of the same color in the Y-axis direction.

  Each head 162 of the discharge unit 160 is arranged so that droplets of the same coating liquid can be discharged simultaneously toward a plurality of light emitting regions that are arranged at intervals in the Y-axis direction and emit light of the same color. A plurality of nozzles 163 are provided side by side in the Y-axis direction. A plurality of nozzles 163 provided in the same head 162 ejects droplets of the same coating liquid.

  The coating device 123a moves the discharge unit 160 and the substrate holding part 151 relative to each other in the X-axis direction, and moves the nozzle toward the opening 31 of the bank 30 formed in advance on the substrate 10 held by the substrate holding part 151. A droplet is applied from 163.

  As shown in FIG. 10, the opening 31 of the bank 30 extends over two light emitting regions adjacent in the Y-axis direction. For this reason, the tolerance of the landing position of the droplet of the coating liquid in the Y-axis direction can be relaxed.

  In addition, since the droplets of the coating liquid are ejected from the two nozzles 163 toward the one opening portion 31, an error in the ejection amount of each nozzle 163 is dispersed, thereby causing variation in the total ejection amount. Can be suppressed. In addition, the number of options for the nozzle 163 that discharges droplets toward one opening 31 is increased, and the nozzle 163 with good discharge amount controllability can be selectively used. By these, the thickness of the light emitting layer 26 can be made uniform.

<Drawing pattern according to first modification>
Next, a drawing pattern according to a first modification of the present embodiment will be described with reference to FIG. FIG. 11 is a plan view illustrating a drawing pattern according to a first modification of the embodiment.

  The area ratio of the red light emitting region 261R, the green light emitting region 261G, and the blue light emitting region 261B is appropriately set according to the respective light emission characteristics, light emission lifetime, and the like. For example, the higher the luminous efficiency and the higher the luminance per unit area, the smaller the area.

  In FIG. 11, the red light emitting region 261R has the smallest area, the green light emitting region 261G has the second smallest area, and the blue light emitting region 261B has the largest area. These light emitting regions 261R, 261G, and 261B have the same dimensions YR, YG, and YB in the Y-axis direction, but have different dimensions XR, XG, and XB in the X-axis direction. Specifically, the dimension YR in the Y-axis direction of the red light emitting area 261R, the dimension YG in the Y-axis direction of the green light-emitting area 261G, and the dimension YB in the Y-axis direction of the blue light-emitting area 261B are the same. In addition, the X-axis dimension XR of the red light emitting area 261R is smaller than the X-axis dimension XG of the green light-emitting area 261G, and the X-axis dimension XG of the green light-emitting area 261G is the X-axis of the blue light-emitting area 261B. It is smaller than the dimension XB in the direction.

  In the first modification, a plurality of red light emitting regions 261R, green light emitting regions 261G, and blue light emitting regions 261B are arranged so that two red light emitting regions 261R are adjacent to each other along the X-axis direction. Specifically, a green light emitting region 261G, a blue light emitting region 261B, a red light emitting region 261R, a red light emitting region 261R, a green light emitting region 261G, and a blue light emitting region 261B are repeatedly arranged in this order to form one light emitting region group. 262 is formed. In other words, the arrangement order of the red light emitting region 261R, the green light emitting region 261G, and the blue light emitting region 261B is reversed in two pixels adjacent in the X-axis direction.

  In the first modification, the opening 31 of the bank 30 exposes two anodes 21 provided corresponding to two sub-pixels of the same color adjacent in the Y-axis direction, as in the above-described embodiment. Thereby, the tolerance of the landing position of the droplet of the coating liquid in the Y-axis direction can be relaxed.

  Further, in the first modification, the opening 31 of the bank 30 exposes two anodes 21 provided corresponding to two sub-pixels of the same color that are adjacent in the X-axis direction. Here, the two anodes 21 corresponding to the two red light emitting regions 261R adjacent in the X-axis direction are exposed. This makes it easy to land the droplet on the red opening 31R while relatively moving the discharge unit 160 and the substrate holding portion 151 in the X-axis direction. For this reason, the tolerance of the landing position of the droplet of the coating liquid for the red light emitting region 261R in the X-axis direction can be relaxed. Further, by connecting the red light emitting region 261R having the smallest dimension in the X-axis direction in the X-axis direction, it is possible to effectively relax the tolerance of the landing position of the coating liquid droplet in the X-axis direction.

  Thus, in the first modification, the opening 31 of the bank 30 includes four anodes provided corresponding to four sub-pixels of the same color (here, red) adjacent in the Y-axis direction and the X-axis direction. 21 is exposed. As a result, the tolerance of the landing position of the coating liquid droplet in the Y-axis direction and the X-axis direction can be relaxed. Further, by connecting the red light emitting region 261R having the smallest area in the Y-axis direction and the X-axis direction, the tolerance of the landing position of the droplet of the coating liquid in the Y-axis direction and the X-axis direction can be effectively reduced. Can do.

  In the first modification, one contact hole 50 is formed in one opening 31 in the organic EL display 1 as in the above-described embodiment. Therefore, in the organic EL display 1 according to the first modification, one contact hole 50 is formed for each of the four red light emitting regions 261R. Further, in the organic EL display 1 according to the first modification, one contact hole 50 is formed for two green light emitting regions 261G, and one contact hole 50 is formed for two blue light emitting regions 261B.

  Here, an example in which one opening 31 exposes two anodes 21 provided corresponding to two sub-pixels of the same color adjacent in the X-axis direction is shown. Not limited to this, the opening 31 may expose two anodes 21 provided corresponding to three or more sub-pixels of the same color that are adjacent in the X-axis direction.

  Further, here, an example is shown in which one opening 31 exposes four anodes 21 provided corresponding to four red light emitting regions 261R adjacent in the Y-axis direction and the X-axis direction. Not limited to this, the opening 31 may expose the four anodes 21 provided corresponding to the four green light emitting regions 261G adjacent in the Y-axis direction and the X-axis direction. In this case, in the light emitting region group 262, for example, a red light emitting region 261R, a blue light emitting region 261B, a green light emitting region 261G, a green light emitting region 261G, a blue light emitting region 261B, and a red light emitting region 261R are repeatedly arranged in this order. May be formed.

  Similarly, the opening 31 may expose the four anodes 21 provided corresponding to the four blue light emitting regions 261B adjacent in the Y axis direction and the X axis direction. In this case, the light emitting region group 262 includes, for example, a green light emitting region 261G, a blue light emitting region 261B, a red light emitting region 261R, a red light emitting region 261R, a green light emitting region 261G, and a blue light emitting region 261B in this order, as in FIG. It may be formed by repeatedly arranging.

  In the first modification, the light emitting regions are connected in both the Y-axis direction and the X-axis direction, but the opening 31 may connect the light emitting regions only in the X-axis direction. That is, the opening 31 may expose only two anodes 21 provided corresponding to two sub-pixels of the same color that are adjacent in the X-axis direction.

<Drawing pattern according to second modification>
FIG. 12 is a plan view illustrating a drawing pattern according to a second modification example of the embodiment. As shown in FIG. 12, the organic EL display 1 according to the second modification has openings 31 that expose a plurality of anodes 21 provided corresponding to a plurality of sub-pixels of the same color that are adjacent in the Y-axis direction. . For example, the opening 31 according to the second modification exposes each part of all the anodes 21 arranged in the Y-axis direction. In other words, the opening 31 according to the second modification is located closest to the Y axis direction negative direction from the anode 21 located closest to the Y axis positive direction among the plurality of anodes 21 arranged in the Y axis direction. It is formed across the anode 21.

  In the second modification, the contact hole 50 is formed in a region between two openings 31 adjacent in the X-axis direction. When the opening 31 is long in the Y-axis direction as in the second modification, it is sufficient for the organic EL display 1 to form the contact hole 50 at a position adjacent to the opening 31 in the Y-axis direction. It may be difficult to form a number of contact holes 50.

  Therefore, in the second modification, the contact hole 50 is formed in the region between the two openings 31 adjacent in the X-axis direction. Thereby, even when the opening 31 that is long in the Y-axis direction is formed in the organic EL display 1, the optimum number of contact holes 50 can be formed in the organic EL display 1.

  Here, in the region between the two openings 31 adjacent in the X-axis direction, it may be difficult to ensure the dimension in the X-axis direction necessary for forming the contact hole 50.

  Therefore, as shown in FIG. 12, only the region where the contact hole 50 is formed may be partially expanded in the X-axis direction among the regions between two openings 31 adjacent in the X-axis direction. In other words, the opening 31 may be formed such that the X-axis direction dimensions XR1, XG1, and XB1 in the portion adjacent to the contact hole 50 are narrower than the X-axis direction dimensions XR2, XG2, and XB2 in the other portions. . By doing in this way, the space for forming the contact hole 50 can be ensured, without expanding the space | interval of the opening parts 31 in a X-axis direction.

  When the region where the contact hole 50 is formed is expanded in the X-axis direction as in the second modification example, the dimensions XR1, XG1, and XB1 of the opening 31 in the portion adjacent to the contact hole 50 are It is preferable that the diameter is larger than the diameter of the discharge port. By forming in this way, it is possible to prevent the droplet of the coating liquid discharged from the nozzle 163 from protruding from the opening 31 and entering the contact hole 50.

  Here, an example in which one contact hole 50 is formed for two sub-pixels of the same color is shown. However, the contact hole 50 may be formed for every three or more sub-pixels of the same color.

<Drawing pattern according to third modification>
FIG. 13 is a plan view showing a drawing pattern according to a third modification of the embodiment. In the third modification, the contact hole 50 may be provided for each of a plurality of adjacent subpixels of different colors. For example, in the organic EL display 1 shown in FIG. 13, the contact hole 50 is provided for each of the red subpixel, the green subpixel, and the blue subpixel, which are three subpixels constituting one pixel. In other words, one contact hole 50 is provided per pixel.

  Here, the gap between the opening 31 of the green light emitting area 261G and the opening 31 of the blue light emitting area 261B is formed wider than the gap between the opening 31 of the red light emitting area 261R and the opening 31 of the green light emitting area 261G. The Therefore, the contact hole 50 is preferably formed in a region between the opening 31 of the green light emitting region 261G and the opening 31 of the blue light emitting region 261B. However, the contact hole 50 may be formed in a region between two pixels adjacent in the Y-axis direction, or formed in a region between two pixels adjacent in the X-axis direction. May be. Further, the contact hole 50 may be provided for each of a plurality of adjacent pixels.

  Further, the contact hole 50 is not limited to a pixel unit (every three subpixels of red, blue, and green), and may be provided for every two subpixels of different colors adjacent to each other or include different colors. It may be provided for every four subpixels. Adjacent directions are not limited to top, bottom, left and right, but may be diagonal. Further, the contact hole 50 may be provided for each of two or more subpixels that are not adjacent to each other. Thus, the contact hole 50 may be provided in units of a plurality of arbitrary subpixels.

  Here, the organic EL display 1 that is not pixel-coupled has been described as an example. However, as shown in FIGS. 10 and 12, for example, the organic EL display 1 has a plurality of light emitting regions of the same color that are adjacent in the Y-axis direction. You may have the opening part 31 which straddles.

  As described above, the coating apparatus 123 a according to the embodiment includes the substrate holding unit 151, the discharge unit 160, and the moving mechanism 152. The substrate holding unit 151 holds the substrate 10. The discharge unit 160 includes a plurality of heads 162 in which a plurality of nozzles 163 are arranged in the first direction (for example, the Y-axis direction). The moving mechanism 152 relatively moves the discharge unit 160 and the substrate holding part 151 along a second direction (for example, the X-axis direction) intersecting the first direction. The substrate 10 includes a plurality of pixel electrodes (for example, an anode 21) provided corresponding to a plurality of subpixels, and a plurality of openings 31 that cover the plurality of pixel electrodes and expose at least one pixel electrode. The bank 30 and a plurality of contact holes 50 for electrically connecting the counter electrodes opposed to the plurality of pixel electrodes to the auxiliary electrode 51 are provided. The contact hole 50 is provided for every two or more subpixels. The discharge unit 160 discharges a droplet of an organic material from the nozzle 163 toward the opening 31 of the substrate 10 held by the substrate holding unit 151.

  Therefore, the coating apparatus 123a according to the embodiment can provide the organic EL display 1 in which the number of contact holes 50 for the auxiliary electrode 51 is optimized.

  The opening 31 may expose two or more pixel electrodes provided corresponding to two or more adjacent sub-pixels of the same color. In this case, the contact hole 50 may be provided for each of two or more sub-pixels of the same color corresponding to the two or more pixel electrodes exposed by the opening 31.

  By forming the opening 31 for landing the organic material droplet not for every sub-pixel but for every two adjacent sub-pixels of the same color, the tolerance of the landing position of the droplet can be relaxed. Further, by providing a contact hole 50 for each of two or more sub-pixels of the same color corresponding to two or more pixel electrodes exposed by the opening 31, the contact hole 50 does not interfere with pixel connection. .

  The opening 31 may expose two or more pixel electrodes provided corresponding to two or more sub-pixels of the same color adjacent in the first direction. Thereby, the tolerance of the landing position of the organic material droplet in the first direction can be relaxed.

  The opening 31 may expose two pixel electrodes provided corresponding to two sub-pixels of the same color that are adjacent in the second direction. Thereby, the tolerance of the landing position of the organic material droplet in the second direction can be relaxed.

  The opening 31 may expose four or more pixel electrodes provided corresponding to four or more sub-pixels of the same color adjacent in the first direction and the second direction. Thereby, the tolerance of the landing position of the organic material droplet in the first direction and the second direction can be relaxed.

  The contact hole 50 may be formed in a region between two openings 31 adjacent in the first direction. This prevents the contact hole 50 from interfering with the pixel connection.

  The contact hole 50 may be formed in a region between two openings 31 adjacent in the second direction. Even when the opening 31 that is long in the Y-axis direction is formed in the organic EL display 1, an optimal number of contact holes 50 can be formed in the organic EL display 1.

  The opening 31 may be formed such that the dimension in the second direction in the part adjacent to the contact hole 50 is narrower than the dimension in the second direction in the other part. Thereby, a space for forming the contact hole 50 can be secured without increasing the interval between the openings 31 in the second direction.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. Indeed, the above-described embodiment can be embodied in various forms. The above embodiments may be omitted, replaced, and changed in various forms without departing from the scope and spirit of the appended claims.

  For example, the combination of emission colors is not limited to the three primary colors of red, green, and blue. In addition to the three primary colors of red, green, and blue, at least one of yellow, which is an intermediate color between red and green, and cyan, which is an intermediate color between green and blue, may be further used.

  In the above-described embodiment and each modification, the bottom emission type organic EL display 1 that takes out light from the light emitting layer 26 from the substrate 10 side is taken as an example. The organic EL display 1 is not limited to this, and may be a top emission method in which light from the light emitting layer 26 is extracted from the side opposite to the substrate 10.

  In the case of the top emission method, the substrate 10 does not necessarily need to be a transparent substrate. In the case of the top emission method, the anode 21 which is a transparent electrode is used as a counter electrode, and the cathode 22 is used as a pixel electrode provided for each unit circuit 11. In this case, since the arrangement of the anode 21 and the cathode 22 is reversed, the electron injection layer 28, the electron transport layer 27, the light emitting layer 26, the hole transport layer 25, and the hole injection layer 24 are arranged in this order on the cathode 22. Formed with.

  In the embodiment and each modification described above, an example in which the organic EL layer 23 includes the hole injection layer 24, the hole transport layer 25, the light emitting layer 26, the electron transport layer 27, and the electron injection layer 28 has been described. The organic EL layer 23 only needs to include at least the light emitting layer 26.

DESCRIPTION OF SYMBOLS 1 Organic EL display 10 Board | substrate 13 Organic light emitting diode 21 Anode 22 Cathode 23 Organic EL layer 26 Light emitting layer 30 Bank 31 Opening part 50 Contact hole 51 Auxiliary electrode 100 Substrate processing system 123a Coating device 151 Substrate holding part 152 Moving mechanism 160 Discharge unit 162 Head 163 Nozzle 261R Red light emitting area 261G Green light emitting area 261B Blue light emitting area

Claims (13)

A substrate holder for holding the substrate;
A discharge unit including a plurality of heads provided with a plurality of nozzles arranged in the first direction;
A moving mechanism for relatively moving the discharge unit and the substrate holder along a second direction intersecting the first direction,
The substrate is
A plurality of pixel electrodes provided corresponding to a plurality of sub-pixels; a bank that covers the plurality of pixel electrodes and that includes a plurality of openings that expose at least one of the pixel electrodes; and the plurality of pixel electrodes A plurality of contact holes for electrically connecting a counter electrode opposed to the auxiliary electrode,
The contact hole is
Provided for each of the two or more sub-pixels;
The discharge unit is
A coating apparatus that ejects droplets of an organic material from the nozzle toward the opening of the substrate held by the substrate holding unit. The contact hole is
The coating apparatus according to claim 1, which is provided for every two or more sub-pixels of the same color. The opening is
Exposing two or more pixel electrodes provided corresponding to two or more adjacent subpixels of the same color;
The contact hole is
The coating apparatus according to claim 2, provided for each of two or more sub-pixels of the same color corresponding to two or more of the pixel electrodes exposed by the opening. The opening is
The coating apparatus according to claim 3, wherein two or more pixel electrodes provided corresponding to the two or more sub-pixels of the same color adjacent in the first direction are exposed. The opening is
The coating apparatus according to claim 3, wherein the two pixel electrodes provided corresponding to the two sub-pixels of the same color adjacent in the second direction are exposed. The opening is
4. The coating apparatus according to claim 3, wherein the four or more pixel electrodes provided corresponding to the four or more sub-pixels of the same color adjacent in the first direction and the second direction are exposed. 5. The contact hole is
The coating apparatus according to claim 3, wherein the coating apparatus is formed in a region between two openings adjacent to each other in the first direction. The contact hole is
The coating apparatus according to claim 3, wherein the coating apparatus is formed in a region between the two openings adjacent to each other in the second direction. The opening is
The coating apparatus according to claim 8, wherein a dimension in the second direction in a part adjacent to the contact hole is formed to be narrower than a dimension in the second direction in the other part. The contact hole is
The coating apparatus according to claim 1, which is provided for each of two or more sub-pixels having different colors. The contact hole is
The coating device according to claim 10, wherein one coating device is provided for at least one pixel. A plurality of pixel electrodes provided corresponding to a plurality of sub-pixels; a bank that covers the plurality of pixel electrodes and that includes a plurality of openings that expose at least one of the pixel electrodes; and the plurality of pixel electrodes A holding step of holding a substrate including a plurality of contact holes for connecting a counter electrode facing the auxiliary electrode with an auxiliary electrode using a substrate holding portion;
A moving step of relatively moving a discharge unit including a plurality of heads provided with a plurality of nozzles arranged side by side in the first direction and the substrate holding unit in a second direction intersecting the first direction;
A discharge step of discharging a droplet of an organic material from the nozzle toward the opening of the substrate held by the substrate holding unit,
The contact hole is
A coating method provided for each of the two or more sub-pixels. A plurality of pixel electrodes provided corresponding to the plurality of subpixels on the substrate;
A bank that covers the plurality of pixel electrodes and has a plurality of openings that expose at least one of the pixel electrodes;
A counter electrode facing the plurality of pixel electrodes;
An organic EL layer provided between the pixel electrode and the counter electrode in the opening;
An auxiliary electrode;
A plurality of contact holes for connecting the counter electrode to the auxiliary electrode,
The contact hole is
An organic EL display provided for every two or more subpixels.

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