JP2019009104A - Manufacturing method of organic el device - Google Patents

Abstract

To provide a manufacturing method of an organic EL device having a thin film sealing structure having a relatively thin organic barrier layer with improved mass productivity and moisture resistance reliability.SOLUTION: A manufacturing method of an organic EL device (100) includes a step A of forming a driving circuit layer (2) on a substrate (1), a step B of forming an inorganic protective layer (Pa) on the driving circuit layer, a step C of forming an organic planarizing layer (Pb) on the inorganic protective layer, a step D of reducing moisture contained in the organic planarization layer, and a step E of forming an organic EL element layer (3) on the organic planarization layer after the step D, and further includes a step of forming an organic polymer film covering the organic planarization layer and a step of removing the organic polymer film after the step C and before the step D.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an organic EL device (for example, an organic EL display device and an organic EL lighting device) and a manufacturing method thereof.

  Organic EL (Electro Luminescence) display devices have been put into practical use. One of the characteristics of the organic EL display device is that a flexible display device can be obtained. The organic EL display device has at least one organic EL element (Organic Light Emitting Diode: OLED) for each pixel and at least one TFT (Thin Film Transistor) that controls a current supplied to each OLED. Hereinafter, the organic EL display device is referred to as an OLED display device. An OLED display device having a switching element such as a TFT for each OLED is called an active matrix OLED display device. A substrate on which TFTs and OLEDs are formed is referred to as an element substrate.

OLEDs (especially organic light-emitting layers and cathode electrode materials) are easily deteriorated by the influence of moisture, and display unevenness is likely to occur. As a technique for protecting the OLED from moisture and providing a sealing structure that does not impair flexibility, a thin film encapsulation (TFE) technique has been developed. In the thin film sealing technique, an inorganic barrier layer and an organic barrier layer are alternately laminated to obtain a sufficient water vapor barrier property with a thin film. From the viewpoint of moisture resistance reliability of the OLED display device, the WVTR (Water Vapor Transmission Rate: WVTR) of the thin film sealing structure is typically required to be 1 × 10 ⁻⁴ g / m ² / day or less.

  A thin film sealing structure used in an OLED display device currently on the market has an organic barrier layer (polymer barrier layer) having a thickness of about 5 μm to about 20 μm. Thus, the relatively thick organic barrier layer also plays a role of flattening the surface of the element substrate. However, when the organic barrier layer is thick, there is a problem that the flexibility of the OLED display device is limited.

  There is also a problem that mass productivity is low. The relatively thick organic barrier layer described above is formed using a printing technique such as an ink jet method or a micro jet method. On the other hand, the inorganic barrier layer is formed in a vacuum (for example, 1 Pa or less) atmosphere using a thin film deposition technique. The formation of the organic barrier layer using the printing technology is performed in the air or in a nitrogen atmosphere, and the formation of the inorganic barrier layer is performed in a vacuum. Therefore, in the process of forming the thin film sealing structure, the element substrate is removed from the vacuum chamber. The mass productivity is low because it is taken in and out.

  Accordingly, for example, as disclosed in Patent Document 1, a film forming apparatus capable of continuously manufacturing an inorganic barrier layer and an organic barrier layer has been developed.

  In Patent Document 2, when the first inorganic material layer, the first resin material, and the second inorganic material layer are formed in this order from the element substrate side, the first resin material is the first resin material. A thin film sealing structure is disclosed that is unevenly distributed around the convex portion of the inorganic material layer (the first inorganic material layer covering the convex portion). According to Patent Document 2, by allowing the first resin material to be unevenly distributed around the convex portion that may not be sufficiently covered with the first inorganic material layer, intrusion of moisture and oxygen from that portion is suppressed. In addition, since the first resin material functions as a base layer for the second inorganic material layer, the second inorganic material layer is appropriately formed, and the side surface of the first inorganic material layer is formed to have an intended film thickness. It becomes possible to coat appropriately. The first resin material is formed as follows. The heated and vaporized mist-like organic material is supplied onto an element substrate maintained at a temperature of room temperature or lower, and the organic material is condensed on the substrate to form droplets. The droplet-like organic material moves on the substrate due to capillary action or surface tension, and is unevenly distributed on the boundary portion between the side surface of the convex portion of the first inorganic material layer and the substrate surface. Thereafter, the first resin material is formed at the boundary by curing the organic material. Patent Document 3 also discloses an OLED display device having a similar thin-film sealing structure. Patent Document 4 discloses a film forming apparatus used for manufacturing an OLED display device.

JP 2013-186971 A International Publication No. 2014/196137 JP-A-2006-39120 JP2013-64187A

  Since the thin film sealing structure described in Patent Document 2 or 3 does not have a thick organic barrier layer, it is considered that the flexibility of the OLED display device is improved. In addition, since the inorganic barrier layer and the organic barrier layer can be continuously formed, mass productivity is also improved.

  However, according to the study of the present inventor, when the organic barrier layer is formed by the method described in Patent Document 2 or 3, there is a problem that sufficient moisture resistance reliability cannot be obtained.

  When an organic barrier layer is formed using a printing method such as an inkjet method, the organic barrier layer is formed only in an active region (also referred to as an “element formation region” or a “display region”) on an element substrate. It can be prevented from being formed in a region other than the active region. Therefore, in the periphery (outside) of the active region, there is a region where the first inorganic material layer and the second inorganic material layer are in direct contact, and the organic barrier layer includes the first inorganic material layer and the second inorganic material layer. Is completely surrounded and isolated from the surroundings.

  On the other hand, in the method for forming an organic barrier layer described in Patent Document 2 or 3, a resin (organic material) is supplied to the entire surface of the element substrate, and the surface tension of the liquid resin is utilized to utilize the surface tension of the liquid resin. Resin is unevenly distributed at the boundary between the side surface of the convex portion and the substrate surface. Therefore, the region outside the active region (also referred to as “peripheral region”), that is, the terminal region where a plurality of terminals are arranged, and the lead wiring region where the lead wiring from the active region to the terminal region is formed are also provided. An organic barrier layer may be formed. Specifically, for example, the resin is unevenly distributed at a boundary portion between the side surface of the lead wiring and the terminal and the substrate surface. If it does so, the edge part of the part of the organic barrier layer formed along the extraction | drawer wiring is not surrounded by the 1st inorganic barrier layer and the 2nd inorganic barrier layer, but is exposed to air | atmosphere (ambient atmosphere).

  Since the organic barrier layer has a lower water vapor barrier property than the inorganic barrier layer, the organic barrier layer formed along the lead-out wiring serves as a path for guiding water vapor in the atmosphere into the active region.

  Here, the problem of the thin film sealing structure suitably used for the flexible organic EL display device has been described. However, the thin film sealing structure is not limited to the organic EL display device, and other organic EL devices such as an organic EL lighting device. Also used for.

  The present invention has been made to solve the above problems, and provides a method for producing an organic EL device having a thin film sealing structure having a relatively thin organic barrier layer and improved in mass productivity and moisture resistance reliability. The purpose is to provide.

  According to an embodiment of the present invention, a method of manufacturing an organic EL device includes a substrate, a plurality of TFTs formed on the substrate, and a plurality of gate bus lines each connected to one of the plurality of TFTs. And a plurality of source bus lines, a plurality of terminals, and a plurality of lead lines connecting the plurality of terminals and the plurality of gate bus lines or the plurality of source bus lines, and a driving circuit layer, Formed on the drive circuit layer, exposing at least the plurality of terminals, an organic planarization layer formed on the inorganic protection layer, and formed on the organic planarization layer, An organic EL element layer having a plurality of organic EL elements connected to any of the plurality of TFTs, and a thin-film sealing structure formed so as to cover the organic EL element layer A manufacturing method of an organic EL device, the manufacturing method comprising: a step A for forming the drive circuit layer on the substrate; a step B for forming the inorganic protective layer on the drive circuit layer; and the inorganic protection Step C for forming the organic planarization layer on the layer, Step D for heating the organic planarization layer to a temperature of 200 ° C. or higher, and the organic EL on the organic planarization layer after the heating step Including the step E of forming an element layer, and after the step C and before the step D, a step C1 of forming an organic polymer film covering the organic planarization layer, and the organic polymer film And removing step C2.

  In one embodiment, the manufacturing method further includes a step of storing or transporting the substrate on which the organic polymer film is formed between the step C1 and the step C2.

  In one embodiment, the step C1 includes a step of applying a solution of the organic polymer onto the organic planarization layer.

  In one embodiment, the organic polymer film is formed from a water-soluble polymer.

  In one embodiment, the step C2 includes a step of dissolving the organic polymer film with an aqueous solvent.

  In one embodiment, the water-soluble polymer is polyvinyl alcohol.

  In one embodiment, the organic planarization layer is made of a photosensitive resin.

  In one embodiment, the organic planarization layer is made of polyimide.

  In one embodiment, when viewed from the normal direction of the substrate, the organic planarization layer is formed in a region in which the inorganic protective layer is formed, and in the region in which the organic planarization layer is formed. The plurality of organic EL elements are arranged, and an outer edge of the thin film sealing structure intersects with the plurality of lead wires, and an outer edge of the organic planarization layer and an outer edge of the inorganic protective layer In the portion where the inorganic protective layer and the first inorganic barrier layer are in direct contact with each other on the plurality of lead wires, the first inorganic barrier layer has a line width direction of the plurality of lead wires. The taper angle of the side surface in the parallel cross-sectional shape is less than 90 °.

  In one embodiment, the taper angle of the side surface of the first inorganic barrier layer is less than 70 °.

  In one embodiment, the manufacturing method includes, after the step E, the step F of selectively forming the first inorganic barrier layer in the active region in which the plurality of organic EL elements are formed, and the step F Later, the step of placing the substrate in the chamber, supplying a vapor or mist of photocurable resin into the chamber, and condensing the photocurable resin on the first inorganic barrier layer. Then, the step H of condensing the photocurable resin so that the photocurable resin does not exist on the portion of the first inorganic barrier layer having a taper angle of less than 90 °; Thereafter, the step I includes forming the organic barrier layer made of a photo-curing resin by irradiating the condensed photo-curing resin with light.

  In one embodiment, the manufacturing method includes, after the step E, the step F of selectively forming the first inorganic barrier layer in the active region in which the plurality of organic EL elements are formed, and the step F Later, the substrate is placed in a chamber, a process G for supplying a vapor or mist-like photocurable resin into the chamber, and the photocurable resin is condensed on the first inorganic barrier layer to form a liquid Step H for forming the film, Step I for forming the photocurable resin layer by irradiating the liquid film of the photocurable resin with light, and partially ashing the photocurable resin layer And the step J of forming the organic barrier layer.

  According to the embodiment of the present invention, there is provided a method for manufacturing an organic EL device including a thin film sealing structure having a relatively thin organic barrier layer and improved in mass productivity and moisture resistance reliability.

(A) is a typical fragmentary sectional view of the active area | region of the OLED display apparatus 100 by embodiment of this invention, (b) is a fragmentary sectional view of the TFE structure 10 formed on OLED3. 1 is a schematic plan view of an OLED display device 100 according to an embodiment of the present invention. (A) And (b) is typical sectional drawing of the OLED display apparatus 100, (a) is sectional drawing along line 3A-3A 'in FIG. 2, (b) is in FIG. It is sectional drawing along a 3B-3B 'line, (c) is sectional drawing which shows taper angle (theta) of the side surface of each layer. (A)-(d) is typical sectional drawing of the OLED display apparatus 100, (a) is sectional drawing along the 4A-4A 'line in FIG. 2, (b) is in FIG. 4C is a cross-sectional view taken along line 4B-4B ′, FIG. 4C is a cross-sectional view taken along line 4C-4C ′ in FIG. 2, and FIG. 4D is a cross-sectional view taken along line 4D-4D ′ in FIG. It is sectional drawing. (A) And (b) is typical sectional drawing corresponding to FIG.4 (b) in OLED display apparatus 100B1 and 100B2 of a comparative example. It is a typical top view of OLED display device 100C of a comparative example. (A) And (b) is typical sectional drawing of OLED display device 100C, (a) is sectional drawing along line 7A-7A 'in FIG. 6, (b) is in FIG. It is sectional drawing along a 7B-7B 'line. (A)-(c) is typical sectional drawing of 100C of OLED display apparatuses, (a) is sectional drawing along the 8A-8A 'line in FIG. 6, (b) is in FIG. FIG. 8C is a cross-sectional view taken along line 8B-8B ′, and FIG. 8C is a cross-sectional view taken along line 8C-8C ′ in FIG. 6. (A) And (b) is typical sectional drawing which shows the example of TFT which the OLED display apparatus by embodiment can have, respectively. (A)-(c) is a typical cross section of the other OLED display apparatus by embodiment, and respond | corresponds to FIG.4 (b)-(d), respectively. (A) And (b) is a figure which shows the structure of the film-forming apparatus 200 typically, (a) is the film-forming apparatus 200 in the process of condensing photocurable resin on a 1st inorganic barrier layer. (B) shows the state of the film forming apparatus 200 in the step of curing the photocurable resin.

  Hereinafter, an OLED display device and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings. In the following, an OLED display device having a flexible substrate will be exemplified, but the embodiment of the present invention is not limited to the organic EL display device, and may be other organic EL devices such as an organic EL lighting device. It is not limited to the embodiment.

  First, a basic configuration of an OLED display device 100 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a schematic partial cross-sectional view of an active region of an OLED display device 100 according to an embodiment of the present invention, and FIG. 1B is a partial cross-sectional view of a TFE structure 10 formed on an OLED 3. It is.

  The OLED display device 100 has a plurality of pixels, and has at least one organic EL element (OLED) for each pixel. Here, for simplicity, a structure corresponding to one OLED will be described.

  As shown in FIG. 1A, an OLED display device 100 includes a flexible substrate (hereinafter, simply referred to as “substrate”) 1 and a circuit (“drive circuit”) including TFTs formed on the substrate 1. 2), an inorganic protective layer 2Pa formed on the circuit 2, an organic planarizing layer 2Pb formed on the inorganic protective layer 2Pa, and an organic planarizing layer 2Pb And the TFE structure 10 formed on the OLED 3. The OLED 3 is, for example, a top emission type. The uppermost part of the OLED 3 is, for example, an upper electrode or a cap layer (refractive index adjusting layer). A layer in which a plurality of OLEDs 3 are arranged may be referred to as an OLED layer 3. An optional polarizing plate 4 is disposed on the TFE structure 10. The circuit 2 and the OLED layer 3 may share some components. In addition, for example, a layer having a touch panel function may be disposed between the TFE structure 10 and the polarizing plate 4. That is, the OLED display device 100 can be modified to an on-cell display device with a touch panel.

The substrate 1 is, for example, a polyimide film having a thickness of 15 μm. The thickness of the circuit 2 including the TFT is, for example, 4 μm. The inorganic protective layer 2Pa is, for example, a SiN _x layer (500 nm) / SiO ₂ layer (100 nm) (upper layer / lower layer). In addition to this, the inorganic protective layer 2Pa may have a three-layer structure of, for example, SiO ₂ layer / SiN _x layer / SiO ₂ layer, and the thickness of each layer is, for example, 200 nm / 300 nm / 100 nm. The organic planarization layer 2Pb is, for example, a photosensitive acrylic resin layer or a photosensitive polyimide layer having a thickness of 4 μm. The thickness of the OLED 3 is, for example, 1 μm. The thickness of the TFE structure 10 is, for example, 2.5 μm or less.

FIG. 1B is a partial cross-sectional view of the TFE structure 10 formed on the OLED 3. A first inorganic barrier layer (for example, a SiN _x layer) 12 is formed immediately above the OLED 3, and an organic barrier layer (for example, an acrylic resin layer) 14 is formed on the first inorganic barrier layer 12. A second inorganic barrier layer (for example, a SiN _x layer) 16 is formed on 14.

For example, the first inorganic barrier layer 12 is, for example, a SiN _x layer having a thickness of 1.5 μm, the second inorganic barrier layer 16 is, for example, a SiN _x layer having a thickness of 800 nm, and the organic barrier layer 14 is, for example, a thickness. Is an acrylic resin layer of less than 100 nm. The thicknesses of the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are independently 200 nm or more and 1500 nm or less, and the thickness of the organic barrier layer 14 is 50 nm or more and less than 200 nm. The thickness of the TFE structure 10 is preferably 400 nm or more and less than 3 μm, and more preferably 400 nm or more and 2.5 μm or less.

  The TFE structure 10 is formed so as to protect the active region (see the active region R1 in FIG. 2) of the OLED display device 100. At least in the active region R1, as described above, in order from the side closer to the OLED 3 The first inorganic barrier layer 12, the organic barrier layer 14, and the second inorganic barrier layer 16 are included. Note that the organic barrier layer 14 does not exist as a film covering the entire surface of the active region R1, but has an opening. A portion of the organic barrier layer 14 excluding the opening and where the organic film actually exists is referred to as a “solid portion”. The organic barrier layer 14 can be formed using, for example, the method described in Patent Document 1 or 2, or the film forming apparatus 200 described later.

  Further, the “opening” (sometimes referred to as “non-solid portion”) does not need to be surrounded by the solid portion and includes a notch or the like, and the first inorganic barrier layer 12 is formed in the opening. And the second inorganic barrier layer 16 are in direct contact. Hereinafter, a portion where the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact is referred to as an “inorganic barrier layer bonding portion”.

  Next, the structure and manufacturing method of the OLED display device 100 according to the embodiment of the present invention will be described with reference to FIGS.

  FIG. 2 is a schematic plan view of the OLED display device 100 according to the embodiment of the present invention. In addition, a cross-sectional structure of the OLED display device 100 will be described with reference to FIGS. 3A to 3C and FIGS. 4A to 4D. 3A and 3B are schematic cross-sectional views of the OLED display device 100, and FIG. 3A is a cross-sectional view taken along line 3A-3A ′ in FIG. ) Is a cross-sectional view taken along line 3B-3B 'in FIG. FIG. 3C is a cross-sectional view showing the taper angle θ of the side surface of each layer. 4A to 4D are schematic cross-sectional views of the OLED display device 100, and FIG. 4A is a cross-sectional view taken along line 4A-4A ′ in FIG. ) Is a cross-sectional view taken along line 4B-4B 'in FIG. 2, FIG. 4C is a cross-sectional view taken along line 4C-4C' in FIG. 2, and FIG. It is sectional drawing along a 4D-4D 'line in the inside.

  First, referring to FIG. The circuit 2 formed on the substrate 1 includes a plurality of TFTs (not shown), a plurality of gate bus lines (not shown) connected to any of the plurality of TFTs (not shown), and a plurality of sources. And a bus line (not shown). The circuit 2 may be a known circuit for driving the plurality of OLEDs 3. The plurality of OLEDs 3 are connected to any of the plurality of TFTs included in the circuit 2. The OLED 3 may also be a known OLED.

  The circuit 2 further includes a plurality of terminals 34 disposed in a peripheral region R2 outside the active region R1 where a plurality of OLEDs 3 are disposed (region surrounded by a broken line in FIG. 2), a plurality of terminals 34, A plurality of lead lines 32 are connected to either the plurality of gate bus lines or the plurality of source bus lines. The entire circuit 2 including a plurality of TFTs, a plurality of gate bus lines, a plurality of source bus lines, a plurality of lead lines 32, and a plurality of terminals 34 may be referred to as a drive circuit layer 2. In the drive circuit layer 2, a portion formed in the active region R1 is referred to as a drive circuit layer 2A.

  2 and the like, only the lead wiring 32 and / or the terminal 34 may be illustrated as components of the drive circuit layer 2, but the drive circuit layer 2 is only a conductive layer including the lead wiring 32 and the terminal 34. Rather, it has one or more additional conductive layers, one or more insulating layers, and one or more semiconductor layers. The configuration of the conductive layer, the insulating layer, and the semiconductor layer included in the drive circuit layer 2 can be changed depending on, for example, the configuration of the TFT illustrated in FIGS. 9A and 9B later. Further, an insulating film (base coat) may be formed on the substrate 1 as a base film of the drive circuit layer 2.

  When viewed from the normal direction of the substrate 1, the organic planarization layer 2Pb is formed in the region where the inorganic protective layer 2Pa is formed, and the active region R1 is formed in the region where the organic planarization layer 2Pb is formed. (2A, 3) are arranged. The outer edge of the thin film sealing structure 10 intersects with the plurality of lead wires 32 and exists between the outer edge of the organic planarization layer 2Pb and the outer edge of the inorganic protective layer 2Pa. Accordingly, the organic planarizing layer 2Pb is surrounded by the OLED layer 3 and the joint portion in which the inorganic protective layer 2Pa and the first inorganic barrier layer 12 are in direct contact (see FIGS. 3B and 4B). . The inorganic protective layer 2Pa is formed so as to expose at least the plurality of terminals 34. Once the inorganic protective film is formed so as to cover the terminal 34, the inorganic protective layer 2Pa having an opening exposing the terminal 34 may be formed by a photolithography process.

  The inorganic protective layer 2Pa protects the drive circuit layer 2. The organic planarizing layer 2Pb planarizes the underlying surface on which the OLED layer 3 is formed. Similar to the organic barrier layer 14, the organic planarization layer 2Pb has a lower water vapor barrier property than the inorganic protective layer 2Pa and the inorganic barrier layers 12 and 16. Therefore, when part of the organic planarization layer 2Pbc of the OLED display device 100C of the comparative example shown in FIGS. 6 to 8 is exposed to the atmosphere (ambient atmosphere), moisture is absorbed therefrom. As a result, the organic planarization layer 2Pbc becomes a path for guiding water vapor in the atmosphere into the active region R1. As described above, in the OLED display device 100 according to the embodiment, the organic planarization layer 2Pb is surrounded by the joint portion in which the inorganic protective layer 2Pa and the first inorganic barrier layer 12 are in direct contact. It is possible to prevent moisture from being guided from 2Pb into the active region R1.

  The organic planarization layer 2Pb is preferably formed from a photosensitive resin. The organic planarization layer 2Pb is formed using various coating methods and printing methods. Moreover, if it has photosensitivity, the organic planarization layer 2Pb can be easily formed only in a predetermined region by a photolithography process. The photosensitive resin may be a positive type or a negative type. A photosensitive acrylic resin or polyimide resin can be preferably used. Of course, if a photoresist is used separately, the organic planarization layer 2Pb can be formed using a resin having no photosensitivity.

  Before forming the OLED layer 3 on the organic planarization layer 2Pb, it is preferable to heat (bake) in order to remove moisture contained in the organic planarization layer 2Pb. The heating temperature is preferably 200 ° C. or higher (eg, 1 hour or longer), for example, and more preferably 300 ° C. or higher (eg, 15 minutes or longer). The atmosphere is preferably under reduced pressure, but may be atmospheric pressure. An atmosphere of dry air or dry nitrogen having a dew point temperature of −50 ° C. or lower is preferable. A resin material having high heat resistance is preferable so that thermal deterioration does not occur in this heating (baking) step, for example, polyimide is preferable.

  In addition, after forming the organic planarization layer 2Pb, the element substrate during manufacture may be temporarily stored or transported before the OLED layer 3 is formed. That is, after the device substrate on which the drive circuit layer 2, the inorganic protective layer 2Pa, and the organic flattening layer 2Pb are formed, there is time until the OLED layer 3 is formed (for example, storage for one day or more for several days). ) Or move to another factory. In the meantime, as a method for preventing the surface of the organic planarization layer 2Pb from being contaminated or adhering dust during movement, for example, an organic polymer film covering the organic planarization layer 2Pb is formed. Good. The organic polymer film is preferably formed so as to cover the entire surface of the organic planarization layer 2Pb.

  The step of forming the organic polymer film includes, for example, a step of applying an organic polymer solution onto the organic planarization layer 2Pb. The solution of the organic polymer is performed using a known coating method (for example, spin coating method and slot coating method). Although a dry film can be used, a method using an organic polymer solution is advantageous from the viewpoint of cost and the like.

  The organic polymer film is preferably formed from a water-soluble polymer. When the organic polymer film is formed of a water-soluble polymer, the organic polymer film can be easily removed by dissolving the organic polymer film with an aqueous solvent. The aqueous solvent can suppress contamination of the element substrate and is environmentally friendly, so that the processing cost can be reduced.

  Examples of the water-soluble polymer include known water-soluble polymers such as polyvinyl alcohol (PVA), polyacrylic acid polymer, polyethylene glycol (PEG), polyethylene oxide (PEO), polyvinyl pyrrolidone (PVP), polyacrylamide (PAM). ), Gelatin and cellulose, and derivatives thereof. Among these, polyvinyl alcohol can be used suitably.

  Here, the aqueous solvent refers to water, an organic solvent miscible with water, or a mixed solvent of water and an organic solvent miscible with water. Examples of the organic solvent miscible with water include alcohols and ketones. Since the lower boiling point of the solvent is preferable, alcohols having a small number of carbon atoms such as methanol and ethanol are preferable.

  When an organic polymer film is formed using polyvinyl alcohol, for example, a solution in which 3% by mass of polyvinyl alcohol is dissolved in a solvent in which pure water and methanol are mixed at a mass ratio of 6: 4 can be used. .

  Thereafter, the mixed solvent is volatilized and removed by leaving it at 100 ° C. or lower, for example, 80 ° C. for about 30 minutes. It is preferable to volatilize and remove the mixed solvent to such an extent that the surface of the organic polymer film is not sticky. The mixed solvent may be volatilized and removed by allowing it to stand at room temperature.

  Of course, an organic polymer film can also be formed using various organic polymers dissolved in an organic solvent. For example, a photoresist can be used. However, it is not necessary to expose the photoresist film. Therefore, either a positive type or a negative type may be used. For example, after applying a photoresist solution (for example, product name OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.), pre-bake (solvent volatilization removal: for example, about 5 minutes to about 110 ° C. in a temperature range of about 90 ° C. By performing heating for about 30 minutes, an organic polymer film can be formed.

  The thickness of the organic polymer film is preferably 1 μm or more and 5 μm or less, for example. If the thickness of the organic polymer film is less than 1 μm, the substrate surface may not be sufficiently protected. On the other hand, when the thickness of the organic polymer film exceeds 5 μm, there is a concern that the internal stress of the organic polymer film may adversely affect the underlayer, or the organic polymer film is cracked and the protective function is impaired. Inconvenience may occur.

  Note that the method of temporarily protecting the organic planarization film using the organic polymer film is preferably applied to the manufacturing method of the OLED display device 100 exemplified here, but is not limited thereto. That is, a method for manufacturing an OLED display device includes a step of forming a drive circuit layer on a substrate, a step of forming an inorganic protective layer on the drive circuit layer, and a step of forming an organic planarizing layer on the inorganic protective layer. After forming the organic planarization layer, including the step of heating the organic planarization layer to a temperature of 200 ° C. or higher and the step of forming the organic EL element layer on the organic planarization layer after the heating step In addition, before the step of heating the organic planarization layer, a step of forming an organic polymer film covering the organic planarization layer and a step of removing the organic polymer film may be further included.

  Next, with reference to FIGS. 3A to 3C and FIGS. 4A to 4D, the cross-sectional structure of the OLED display device 100 will be described in more detail.

As shown in FIGS. 3A and 3B and FIGS. 4A and 4B, the TFE structure 10 includes a first inorganic barrier layer 12 formed on the OLED 3 and a first inorganic barrier layer 12. It has an organic barrier layer 14 in contact with it and a second inorganic barrier layer 16 in contact with the organic barrier layer 14. The first inorganic barrier layer 12 and the second inorganic barrier layer 16 are, for example, SiN _x layers, and are selectively formed only in a predetermined region so as to cover the active region R1 by a plasma CVD method using a mask. .

  The organic barrier layer 14 can be formed, for example, by the method described in Patent Document 2 or 3. For example, in a chamber, a vapor or mist-like organic material (for example, acrylic monomer) is supplied onto an element substrate maintained at a temperature below room temperature, condensed on the element substrate, and a capillary tube of the organic material that has become liquid Due to the phenomenon or surface tension, the first inorganic barrier layer 12 is unevenly distributed at the boundary portion between the side surface of the convex portion and the flat portion. Then, the solid part of the organic barrier layer (for example, acrylic resin layer) 14 is formed in the boundary part around the convex part by irradiating the organic material with, for example, ultraviolet rays. The organic barrier layer 14 formed by this method has substantially no solid part in the flat part. Regarding the method of forming the organic barrier layer, the disclosures of Patent Documents 2 and 3 are incorporated herein by reference.

The organic barrier layer 14 is also adjusted by adjusting the initial thickness of the resin layer formed using the film forming apparatus 200 (for example, less than 100 nm) and / or by ashing the resin layer once formed. Can also be formed. As will be described in detail later, the ashing treatment can be performed by, for example, plasma ashing using at least one of N ₂ O, O _2, and O ₃ .

  FIG. 3A is a cross-sectional view taken along the line 3A-3A ′ in FIG. The particles P are fine dust generated during the manufacturing process of the OLED display device, and are, for example, fine glass fragments, metal particles, and organic particles. When the mask vapor deposition method is used, particles are particularly likely to be generated.

  As shown in FIG. 3A, the organic barrier layer (solid portion) 14 can be formed only around the particle P. This is because the acrylic monomer applied after forming the first inorganic barrier layer 12 is condensed and unevenly distributed around the surface of the first inorganic barrier layer 12a on the particle P (taper angle θ is 90 ° or more). It is. On the flat part of the first inorganic barrier layer 12, an opening (non-solid part) of the organic barrier layer 14 is formed.

When particles (for example, a diameter of about 1 μm or more) P exist, cracks (defects) 12 c may be formed in the first inorganic barrier layer 12. This is considered to have occurred because the SiN _x layer 12a growing from the surface of the particle P and the SiN _x layer 12b growing from the flat portion of the surface of the OLED 3 collide (impinge). When such a crack 12c exists, the barrier property of the TFE structure 10 is lowered.

  In the TFE structure 10 of the OLED display device 100, as shown in FIG. 3A, the organic barrier layer 14 is formed so as to fill the cracks 12c of the first inorganic barrier layer 12, and the organic barrier layer 14 The surface continuously and smoothly connects the surface of the first inorganic barrier layer 12 a on the particle P and the surface of the first inorganic barrier layer 12 b on the flat portion of the OLED 3. Therefore, a dense film is formed without forming defects in the first inorganic barrier layer 12 and the second inorganic barrier layer 16 formed on the organic barrier layer 14 on the particles P. As described above, the organic barrier layer 14 can maintain the barrier property of the TFE structure 10 even when the particles P are present.

  Next, with reference to FIG. 3B and FIGS. 4A to 4D, a cross-sectional structure on the lead wiring 32 and the terminal 34 will be described.

  As shown in FIG. 3B, the lead-out wiring 32 and the terminal 34 are integrally formed on the substrate 1, and the inorganic protective layer 2Pa is formed on the lead-out wiring 32 so that the terminal 34 is exposed. ing. An organic planarization layer 2Pb is formed on the inorganic protective layer 2Pa, and an OLED layer 3 is formed on the organic planarization layer 2Pb. The TFE structure 10 is formed so as to cover the OLED layer 3 and the organic planarization layer 2Pb, and the OLED layer 3 and the organic planarization layer 2Pb are in direct contact with the inorganic protective layer 2Pa and the first inorganic barrier layer 12. Surrounded by a joint. Note that the organic barrier layer (solid portion) 14 between the first inorganic barrier layer 12 and the second inorganic barrier layer 16 of the TFE structure 10 is formed only around convex portions such as particles. Not shown. The organic barrier layer (solid portion) 14 is surrounded by an inorganic barrier layer bonding portion in which the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact.

  As shown in FIG. 4A, in the region close to the active region R1 (cross section taken along the line 4A-4A ′ in FIG. 2), the inorganic protective layer 2Pa and the organic planarizing layer are formed on the lead wiring 32. A 2Pb and TFE structure 10 is formed.

  As shown in FIG. 4B, in the cross section taken along line 4B-4B ′ in FIG. 2, the inorganic protective layer 2Pa and the first inorganic barrier layer 12 are in direct contact, and the organic planarizing layer 2Pb Is surrounded by a joint portion in which the inorganic protective layer 2Pa and the first inorganic barrier layer 12 are in direct contact (see FIGS. 2 and 3B).

  As shown in FIG. 4C, only the inorganic protective layer 2 Pa is formed on the lead-out wiring 32 in the region close to the terminal 34.

  As shown in FIG. 4D, the terminal 34 is also exposed from the inorganic protective layer 2Pa, and is used for electrical connection with an external circuit (for example, FPC (Flexible printed circuits)).

  Since the region including the portion shown in FIGS. 4B to 4D is not covered with the organic planarization layer 2Pb, the organic barrier layer (solid) is formed in the process of forming the organic barrier layer 14 of the TFE structure 10. Part) may be formed. For example, when the side surface in the cross-sectional shape parallel to the line width direction of the lead wiring 32 has a taper angle θ of 90 ° or more, the organic barrier layer can be formed along the side surface of the lead wiring 32. However, as shown in FIGS. 4B to 4D, the OLED display device 100 according to the embodiment has a side taper angle θ of 90 ° in the cross-sectional shapes of the lead-out wiring 32 and the terminal 34 at least in these regions. The photocurable resin is not unevenly distributed. Therefore, the organic barrier layer (solid portion) is not formed along the side surfaces of the lead wiring 32 and the terminal 34.

  Here, the taper angle θ of the side surface of each layer will be described with reference to FIG. FIG. 3C is a cross-sectional view showing the taper angle θ of the side surface of each layer, and corresponds to, for example, the cross-sectional view shown in FIG. As shown in FIG. 3C, the taper angle θ of the side surface in the cross-sectional shape parallel to the width direction of the lead-out wiring 32 is expressed as θ (32), and the taper angle θ of the side surface of the other layer is similarly θ ( It is expressed by a reference numeral of a component.

  Then, each taper angle θ of the inorganic protective layer 2Pa formed on the lead wiring 32, the first inorganic barrier layer 12 of the TFE structure 10 formed on the inorganic protective layer 2Pa, and the second inorganic barrier layer 16 is The relationship θ (32) ≧ θ (2 Pa) ≧ θ (12) ≧ θ (16) is satisfied. Therefore, if the taper angle θ (32) of the side surface of the lead wiring 32 is less than 90 °, the taper angle θ (2 Pa) of the side surface of the inorganic protective layer 2Pa and the taper angle θ (12 of the side surface of the first inorganic barrier layer 12). ) Is also less than 90 °.

  When the taper angle θ of the side surface is 90 ° or more, in the organic barrier layer forming method described in Patent Document 2 or 3, along the boundary between the side surface and the flat surface (which forms an angle of 90 ° or less), Steam or mist-like organic material (for example, acrylic monomer) is condensed, and an organic barrier layer (solid portion) is formed. In this case, for example, an organic barrier layer (solid portion) formed along the lead wiring becomes a path for guiding water vapor in the atmosphere into the active region.

  For example, as shown in a schematic cross-sectional view corresponding to FIG. 4B in the OLED display device 100B1 of the comparative example of FIG. 5A, the side taper angle θ (32B1) of the lead wiring 32B1 and the first inorganic barrier are shown. When the side taper angle θ (12B1) of the layer 12B1 is 90 ° or more, along the side surface of the first inorganic barrier layer 12B1 of the TFE structure 10B1, between the first inorganic barrier layer 12B1 and the second inorganic barrier layer 16B1. The organic barrier layer (solid portion) 14B1 is formed on the substrate. In the OLED display device 100B1, for example, the inorganic protective layer Pa in the OLED display device 100 according to the embodiment is omitted, and the side taper angle θ (32) of the lead-out wiring 32 and the side taper angle of the first inorganic barrier layer 12 are omitted. θ (12) may be modified to 90 ° or more.

  Further, as shown in the schematic cross-sectional view corresponding to FIG. 4B in the OLED display device 100B2 of the comparative example of FIG. 5B, the lead-out wiring 32B2, the inorganic protective layer 2PaB2, and the first inorganic barrier layer 12B2 When the side taper angles θ (32B2), θ (2PaB2), and θ (12B1) are 90 ° or more, the first inorganic barrier layer 12B2 and the second inorganic barrier layer 12B2 are formed along the side surface of the first inorganic barrier layer 12B2 of the TFE structure 10B2. An organic barrier layer (solid portion) 14B2 is formed between the inorganic barrier layer 16B2. In the OLED display device 100B2, for example, the side taper angle θ (32) of the lead wiring 32 and the side taper angle θ (12) of the first inorganic barrier layer 12 in the OLED display device 100 according to the embodiment are modified to 90 ° or more. It may have been.

  Unlike the OLED display device 100B1, the OLED display device 100B2 has the inorganic protective layer 2PaB2, and therefore the side taper angle θ (12B2) of the first inorganic barrier layer 12B2 is the first inorganic barrier layer of the OLED display device 100B1. It tends to be smaller than the side taper angle θ (12B1) of 12B1.

  In the OLED display device 100 according to the embodiment of the present invention shown in FIGS. 4B to 4D, taper angles θ (32), θ (on the side surfaces of the lead wiring 32, the inorganic protective layer 2Pa, and the first inorganic barrier layer 12 are illustrated. 2Pa) and θ (12) are both less than 90 °, and the organic barrier layer 14 is not formed along these side surfaces. Therefore, moisture in the atmosphere does not reach the active region R1 via the organic barrier layer (solid portion) 14, and excellent moisture resistance reliability can be obtained. Here, an example in which the taper angles θ (32), θ (2Pa), and θ (12) are all less than 90 ° is shown, but the present invention is not limited to this, and at least the surface immediately below the organic barrier layer 14 is configured. If the taper angle θ (12) of the side surface of the first inorganic barrier layer 12 is less than 90 °, the laminated structure shown in FIG. 4B (the inorganic protective layer 2Pa and the first inorganic barrier layer 12 are in direct contact with each other) Part (the organic planarization layer 2Pb is not present) and the part where the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are in direct contact (the organic barrier layer 14 is not present) are formed. Therefore, it is possible to suppress / prevent moisture in the atmosphere from entering the active region R1 through the organic planarization layer 2Pa or the organic barrier layer 14. Further, by including the inorganic protective layer 2Pa, 1 Inorganic barrier layer Since the taper angle θ (12) of the first inorganic barrier layer 12 can be reduced even if the taper angle θ (32) of the lead-out wiring 32 is relatively large (for example, 90 °). 12) can be made less than 90 °, that is, the taper angle θ (32) of the lead-out wiring 32 can be brought close to 90 ° or 90 °, so that the L / S of the lead-out wiring 32 can be reduced. The advantage is obtained.

  In the range where the side taper angle θ is not less than 70 ° and less than 90 °, the organic barrier layer (solid portion) 14 may be formed along the side surface. Of course, if the ashing process is performed, the resin that is unevenly distributed along the inclined side surface can be removed, but the time required for the ashing process becomes longer. For example, a long ashing process is required even after removing the resin formed on the flat surface. Alternatively, as a result of excessive ashing (removal) of the organic barrier layer (solid portion) formed around the particle P, there may be a problem that the effect of forming the organic barrier layer is not sufficiently exhibited. In order to suppress / prevent this, the taper angle θ (12) of the first inorganic barrier layer 12 is preferably less than 70 °, and more preferably less than 60 °.

  Next, the structure of the OLED display device 100C of the comparative example will be described with reference to FIGS. FIG. 6 is a schematic plan view of the OLED display device 100C. 7A and 7B are schematic cross-sectional views of the OLED display device 100C, and FIG. 7A is a cross-sectional view taken along the line 7A-7A ′ in FIG. ) Is a cross-sectional view taken along line 7B-7B 'in FIG. 8A to 8C are schematic cross-sectional views of the OLED display device 100C, and FIG. 8A is a cross-sectional view taken along the line 8A-8A ′ in FIG. ) Is a cross-sectional view taken along line 8B-8B 'in FIG. 6, and FIG. 8C is a cross-sectional view taken along line 8C-8C' in FIG.

  The OLED display device 100C is different from the OLED display device 100 according to the embodiment in that it does not have the inorganic protective layer 2Pa and the organic planarizing layer 2Pbc extends to a region not covered with the TFE structure 10. . In addition, the same reference number is attached | subjected to the component substantially the same as the component which the OLED display apparatus 100 has, and description is abbreviate | omitted.

  For example, as is apparent from FIGS. 6, 7B and 8B, a part of the organic planarization layer 2Pbc is exposed to the atmosphere (ambient atmosphere). As a result, the organic planarization layer 2Pbc absorbs moisture from a portion exposed to the atmosphere and becomes a path for guiding water vapor in the atmosphere into the active region R1. On the other hand, in the OLED display device 100 according to the embodiment, as shown in FIGS. 3B and 4B, the organic planarization layer 2Pb, together with the OLED layer 3, includes the inorganic protective layer 2Pa and the first inorganic layer. The barrier layer 12 is surrounded by a joint part in direct contact. Therefore, the above-described problems of the OLED display device 100C of the comparative example can be solved.

  Next, referring to FIG. 9 and FIG. 10, examples of TFTs used in the OLED display device 100, and examples of lead wires and terminals formed using a gate metal layer and a source metal layer when manufacturing the TFTs are shown. explain. The structure of the TFT, the lead wiring, and the terminal described below can be used for the OLED display device 100 of the above-described embodiment.

  For high-definition small and medium OLED display devices, high mobility low temperature polysilicon (abbreviated as “LTPS”) TFT or oxide TFT (for example, In (indium), Ga (gallium), Zn (zinc) And quaternary (In—Ga—Zn—O) oxide TFT) containing O (oxygen). Since the structure and manufacturing method of the LTPS-TFT and the In—Ga—Zn—O-based TFT are well known, only a brief description will be given below.

9 (a) is a schematic sectional view of the _{LTPS-TFT2 P T, TFT2 P} T may be included in the circuit 2 of the OLED display device 100. LTPS-TFT2 _P T is a top-gate type TFT.

The TFT 2 _P T is formed on the base coat 2 _P p on the substrate (for example, polyimide film) 1. Although omitted in the above description, it is preferable to form a base coat made of an inorganic insulator on the substrate 1.

TFT 2 _P T is formed with the base coat 2 _P p on the formed polysilicon layer 2 _P se, a gate insulating layer 2 _P gi formed on the polysilicon layer 2 _P se, the gate insulating layer 2 _P gi a gate electrode 2 _P g which is, and the interlayer insulating layer 2 _P i formed on the gate electrode 2 _P g, the source electrode 2 _P ss and drain electrodes 2 _P sd formed in the interlayer insulating layer 2 _P i have. The source electrode 2 _P ss and the drain electrode 2 _P sd are connected to the source region and the drain region of the polysilicon layer 2 _P se in the contact holes formed in the interlayer insulating layer 2 _P i and the gate insulating layer 2 _P gi, respectively. Has been.

The gate electrode 2 _P g is included in the same gate metal layer and the gate bus line, a source electrode 2 _P ss and drain electrodes 2 _P sd is included in the same source metal layer and the source bus line. Lead wires and terminals are formed using the gate metal layer and the source metal layer (described later with reference to FIG. 10).

TFT 2 _P T, for example, be fabricated in the following manner.

  For example, a polyimide film having a thickness of 15 μm is prepared as the substrate 1.

Base coat 2 _P p (SiO ₂ film: 250 nm / SiN _x film: 50 nm / SiO ₂ film: 500 nm (upper layer / intermediate layer / lower layer)) and a-Si film (40 nm) are formed by plasma CVD.

  Dehydrogenation treatment (for example, annealing at 450 ° C. for 180 minutes) of the a-Si film is performed.

  The a-Si film is made into polysilicon by excimer laser annealing (ELA).

  An active layer (semiconductor island) is formed by patterning the a-Si film in a photolithography process.

A gate insulating film (SiO ₂ film: 50 nm) is formed by plasma CVD.

Doping (B ⁺ ) is performed on the channel region of the active layer.

Gate metal: a (Mo 250 nm) was deposited by sputtering, (to form the gate electrode 2 _P g and the gate bus lines, etc.) that a photolithography process for patterning (including a dry etching process).

Doping (P ⁺ ) is performed on the source region and drain region of the active layer.

Activation annealing (for example, annealing at 450 ° C. for 45 minutes) is performed. In this way, the polysilicon layer 2 _P se is obtained.

An interlayer insulating film (for example, SiO ₂ film: 300 nm / SiN _x film: 300 nm (upper layer / lower layer)) is formed by plasma CVD.

Contact holes are formed in the gate insulating film and the interlayer insulating film by dry etching. Thus, the interlayer insulating layer 2 _P i and the gate insulating layer 2 _P gi are obtained.

Source metal (Ti film: 100 nm / Al film: 300 nm / Ti film: 30 nm) is formed by sputtering and patterned by a photolithography process (including a dry etching process) (source electrode 2 _P ss and drain electrode 2 _P sd and source bus lines are formed).

  Thereafter, the above-described inorganic protective layer 2Pa (see FIGS. 2 and 3) is formed.

FIG. 9B is a schematic cross-sectional view of an In—Ga—Zn—O-based TFT 2 _O T, and the TFT 2 _O T can be included in the circuit 2 of the OLED display device 100A. TFT2 _O T is a bottom-gate type TFT.

The TFT 2 _O T is formed on the base coat 2 _O p on the substrate (for example, polyimide film) 1. The TFT 2 _O T is formed on the gate electrode 2 _O g formed on the base coat 2 _O p, the gate insulating layer 2 _O gi formed on the gate electrode 2 _O g, and the gate insulating layer 2 _O gi. The oxide semiconductor layer 2 _O se has a source electrode 2 _O ss and a drain electrode 2 _O sd connected to the source region and the drain region of the oxide semiconductor layer 2 _O se, respectively. The source electrode 2 _O ss and the drain electrode 2 _O sd are covered with an interlayer insulating layer 2 _O i.

The gate electrode 2 _O g is included in the same gate metal layer as the gate bus line, and the source electrode 2 _O ss and the drain electrode 2 _O sd are included in the same source metal layer as the source bus line. Lead wires and terminals are formed using the gate metal layer and the source metal layer, and may have a structure described later with reference to FIG.

TFT 2 _O T is prepared, for example, in the following manner.

  For example, a polyimide film having a thickness of 15 μm is prepared as the substrate 1.

Base coat 2 _O p (SiO ₂ film: 250 nm / SiN _x film: 50 nm / SiO ₂ film: 500 nm (upper layer / intermediate layer / lower layer)) is formed by plasma CVD.

Gate metal (Cu film: 300 nm / Ti film: 30 nm (upper layer / lower layer)) is formed by sputtering, and patterned by a photolithography process (including a dry etching process) (gate electrode 2 _O g, gate bus line, etc.) Form).

A gate insulating film (SiO ₂ film: 30 nm / SiN _x film: 350 nm (upper layer / lower layer)) is formed by plasma CVD.

  An oxide semiconductor film (In—Ga—Zn—O-based semiconductor film: 100 nm) is formed by sputtering, and patterned by a photolithography process (including a wet etching process) to form an active layer (semiconductor island). To do.

Source metal (Ti film: 100 nm / Al film: 300 nm / Ti film: 30 nm (upper layer / intermediate layer / lower layer)) is formed by sputtering, and patterned by a photolithography process (including a dry etching process) (source electrode) 2 _O ss, drain electrode 2 _O sd, source bus line and the like are formed).

Activation annealing (for example, annealing at 300 ° C. for 120 minutes) is performed. In this way, the oxide semiconductor layer 2 _O se is obtained.

Thereafter, an interlayer insulating layer 2Oi (for example, SiN _x film: 300 nm / SiO ₂ film: 300 nm / (upper layer / lower layer)) is formed as a protective film by a plasma CVD method. This interlayer insulating layer 2Oi can also serve as the above-described inorganic protective layer 2Pa (see FIGS. 2 and 3). Of course, an inorganic protective layer 2Pa may be further formed on the interlayer insulating layer 2Oi.

Next, the structure of another OLED display device according to the embodiment will be described with reference to FIGS. Circuit (backplane) 2 of the OLED display device has a TFT 2 _O T shown in TFT 2 _P T or FIG 9 (b) shown in FIG. 9 (a), to produce a TFT 2 _P T or TFT 2 _O T The leading wiring 32A and the terminal 34A are formed using the gate metal layer and the source metal layer. FIGS. 10A to 10C correspond to FIGS. 4B to 4D, respectively, and “A” is given to the reference numerals of the corresponding components. Further, the base coat 2p in FIG. 10 corresponds to the base coat 2 _P p in FIG. 9A and the base coat 2 _O p in FIG. 9B, and the gate insulating layer 2gi in FIG. Corresponding to the gate insulating layer 2 _P gi in a) and the gate insulating layer 2 _O gi in FIG. 9B, the interlayer insulating layer 2 i in FIG. 10 is the interlayer insulating layer 2 _{P in} FIG. i corresponds to the interlayer insulating layer 2 _O i in FIG. 9B.

  As shown in FIGS. 10A to 10C, the gate metal layer 2 g and the source metal layer 2 s are formed on the base coat 2 p formed on the substrate 1. Although omitted in FIGS. 3 and 4, it is preferable to form a base coat 2 p formed of an inorganic insulator on the substrate 1.

  As shown in FIGS. 10A to 10C, the lead wiring 32A and the terminal 34A are formed as a stacked body of the gate metal layer 2g and the source metal layer 2s. The portion formed of the lead wiring 32A and the gate metal layer 2g of the terminal 34A has, for example, the same cross-sectional shape as the gate bus line, and the portion formed of the lead wiring 32A and the source metal layer 2s of the terminal 34A includes, for example, the source It has the same cross-sectional shape as the bus line. For example, in the case of a 5.7 type display device of 500 ppi, the line width of the portion formed by the gate metal layer 2g is, for example, 10 μm, the distance between adjacent portions is 16 μm (L / S = 10/16), and the source metal The line width of the portion formed by the layer 2s is, for example, 16 μm, and the distance between adjacent portions is 10 μm (L / S = 16/10). The taper angle θ is less than 90 °, preferably less than 70 °, and more preferably 60 ° or less. The taper angle of the portion formed below the organic planarization layer Pb may be 90 ° or more.

  Next, a film forming apparatus 200 used for forming the organic barrier layer and a film forming method using the same will be described with reference to FIGS. FIGS. 11A and 11B are diagrams schematically showing the configuration of the film forming apparatus 200. FIG. 11A shows the first configuration in a chamber containing vapor or mist-like photocurable resin. FIG. 11B shows a state of the film forming apparatus 200 in the process of condensing the photocurable resin on the inorganic barrier layer, and FIG. 11B irradiates light that makes the photocurable resin photosensitive. The state of the film-forming apparatus 200 in the process of curing is shown.

  The film forming apparatus 200 includes a chamber 210 and a partition wall 234 that divides the inside of the chamber 210 into two spaces. A stage 212 and a shower plate 220 are arranged in one space of the inside of the chamber 210 that is partitioned by the partition wall 234. An ultraviolet irradiation device 230 is arranged in the other space partitioned by the partition wall 234. The chamber 210 is controlled to have a predetermined pressure (degree of vacuum) and temperature in the internal space. The stage 212 has an upper surface that receives the element substrate 20 having a plurality of OLEDs 3 on which the first inorganic barrier layer is formed, and the upper surface can be cooled to, for example, −20 ° C.

  The shower plate 220 is disposed so as to form a gap 224 between the shower plate 220 and the partition wall 234, and has a plurality of through holes 222. The vertical size of the gap 224 can be, for example, 100 mm or more and 1000 mm or less. The acrylic monomer (vapor or mist) supplied to the gap portion 224 is supplied from the plurality of through holes 222 of the shower plate 220 to the space on the stage 212 side in the chamber 210. The acrylic monomer is heated as necessary. The vapor or mist of acrylic monomer 26p adheres to or contacts the first inorganic barrier layer of the element substrate 20. The acrylic monomer 26 is supplied from the container 202 into the chamber 210 at a predetermined flow rate. The acrylic monomer 26 is supplied to the container 202 through the pipe 206 and nitrogen gas is supplied from the pipe 204. The flow rate of the acrylic monomer to the container 202 is controlled by the mass flow controller 208. The shower plate 220, the container 202, the pipes 204 and 206, the mass flow controller 208 and the like constitute a raw material supply apparatus.

  The ultraviolet irradiation device 230 has an ultraviolet light source and an optional optical element. The ultraviolet light source may be, for example, an ultraviolet lamp (for example, a mercury lamp (including high pressure and ultrahigh pressure), a mercury xenon lamp, or a metal halide lamp). The optical element is, for example, a reflecting mirror, a prism, a lens, and a diffractive element.

  When the ultraviolet irradiation device 230 is disposed at a predetermined position, the ultraviolet irradiation device 230 emits light having a predetermined wavelength and intensity toward the upper surface of the stage 212. The partition wall 234 and the shower plate 220 are preferably formed of a material having a high ultraviolet transmittance, such as quartz.

  Using the film forming apparatus 200, the organic barrier layer 14 can be formed, for example, as follows. Here, an example in which an acrylic monomer is used as the photocurable resin will be described.

  The acrylic monomer 26p is supplied into the chamber 210. The element substrate 20 is cooled to, for example, −15 ° C. on the stage 212. The acrylic monomer 26 p is condensed on the first inorganic barrier layer 12 of the element substrate 20. By controlling the conditions at this time, the liquid acrylic monomer can be unevenly distributed only around the convex portion of the first inorganic barrier layer 12. Alternatively, the conditions are controlled so that the acryl monomer condensed on the first inorganic barrier layer 12 forms a liquid film.

  By adjusting the viscosity and / or surface tension of the liquid photocurable resin, the thickness of the liquid film and the shape (concave shape) of the portion in contact with the convex portion of the first inorganic barrier layer 12 can be controlled. For example, the viscosity and the surface tension depend on the temperature, and can be controlled by adjusting the temperature of the element substrate. For example, the size of the solid part existing on the flat part can be controlled by the shape of the part of the liquid film in contact with the convex part of the first inorganic barrier layer 12D (concave shape) and the conditions of the ashing process to be performed later.

Subsequently, the acrylic monomer on the first inorganic barrier layer 12 is cured by typically irradiating the entire upper surface of the element substrate 20 with the ultraviolet rays 232 using the ultraviolet irradiation device 230U. As an ultraviolet light source, for example, a high-pressure mercury lamp having a main peak at 365 nm is used, and irradiation is performed at an ultraviolet intensity of, for example, 12 mW / cm ² for about 10 seconds.

  The organic barrier layer 14 made of acrylic resin is formed in this way. The tact time of the formation process of the organic barrier layer 14 is, for example, less than about 30 seconds, and the mass productivity is very high.

  The organic barrier layer 14 may be formed only around the convex portion after the liquid film-like photocurable resin is cured and then subjected to an ashing process. An ashing process may also be performed when the organic barrier layer 14 is formed by curing the unevenly distributed photocurable resin. The adhesion between the organic barrier layer 14 and the second inorganic barrier layer 16 can be improved by the ashing treatment. That is, the ashing treatment may be used not only to remove an excess portion of the organic barrier layer once formed but also to modify (hydrophilize) the surface of the organic barrier layer 14.

Ashing can be performed using a known plasma ashing device, photoexcited ashing device, or UV ozone ashing device. For example, plasma ashing using at least one of N ₂ O, O _2, and O ₃ , or further combined with ultraviolet irradiation may be performed. If the first inorganic barrier layer 12 and the second inorganic barrier layer 16 is deposited to the SiN _x film by the CVD method, as a raw material gas, since use of N ₂ O, the apparatus can be simplified and using N ₂ O ashing The advantage is obtained.

  When ashing is performed, the surface of the organic barrier layer 14 is oxidized and modified to be hydrophilic. In addition, the surface of the organic barrier layer 14 is scraped almost uniformly, extremely fine irregularities are formed, and the surface area is increased. The effect of increasing the surface area when ashing is performed is greater on the surface of the organic barrier layer 14 than on the first inorganic barrier layer 12 that is an inorganic material. Therefore, since the surface of the organic barrier layer 14 is modified to be hydrophilic and the surface area is increased, the adhesion with the second inorganic barrier layer 16 is improved.

  Then, it conveys to the CVD chamber for forming the 2nd inorganic barrier layer 16, and forms the 2nd inorganic barrier layer 16 on the same conditions as the 1st inorganic barrier layer 12, for example. Since the second inorganic barrier layer 16 is formed in the region where the first inorganic barrier layer 12 is formed, the first inorganic barrier layer 12 and the second inorganic barrier layer 16 are formed in the non-solid portion of the organic barrier layer 14. Inorganic barrier layer joints are formed in direct contact with each other. Therefore, as described above, it is suppressed / prevented that water vapor in the atmosphere reaches the active region through the organic barrier layer.

The first inorganic barrier layer 12 and the second inorganic barrier layer 16 are formed as follows, for example. With a plasma CVD method using SiH ₄ and N ₂ O gas, for example, in a state where the temperature of the substrate to be deposited (OLED 3) is controlled to 80 ° C. or less, the deposition rate is 400 nm / min and the thickness is 400 nm. An inorganic barrier layer can be formed. The inorganic barrier layer thus obtained has a refractive index of 1.84, and a visible light transmittance of 400 nm is 90% (thickness 400 nm). The absolute value of the film stress is 50 MPa.

In addition to the SiN _x layer, a SiO ₂ layer, a SiO _x N _y (x> y) layer, a SiN _x O _y (x> y) layer, an Al ₂ O ₃ layer, or the like can be used as the inorganic barrier layer. . The photocurable resin includes, for example, a vinyl group-containing monomer. Among these, acrylic monomers are preferably used. A photoinitiator can be mixed with the acrylic monomer as needed. Various known acrylic monomers can be used. A plurality of acrylic monomers may be mixed. For example, a bifunctional monomer and a trifunctional or higher polyfunctional monomer may be mixed. Moreover, you may mix an oligomer. The viscosity at room temperature (for example, 25 ° C.) before curing of the photocurable resin is preferably not more than 10 Pa · s, and particularly preferably 1 to 100 mPa · s. When the viscosity is high, it may be difficult to form a thin liquid film having a thickness of 500 nm or less.

  In the above description, the embodiment of the OLED display device having the flexible substrate and the manufacturing method thereof has been described. However, the embodiment of the present invention is not limited to the illustrated embodiment, and is formed on a substrate having no flexibility (for example, a glass substrate). The present invention can be widely applied to an organic EL device (for example, an organic EL lighting device) having an organic EL element and a thin film sealing structure formed on the organic EL element.

  Embodiments of the present invention are used in an organic EL device and a manufacturing method thereof. The embodiment of the present invention is particularly suitably used for a flexible organic EL display device and a manufacturing method thereof.

1: Flexible substrate 2: Backplane (circuit)
3: Organic EL element 4: Polarizing plate 10: Thin film sealing structure (TFE structure)
12: First inorganic barrier layer (SiN _x layer)
14: Organic barrier layer (acrylic resin layer)
16: Second inorganic barrier layer (SiN _x layer)
20: Element substrate 26: Acrylic monomer 26p: Acrylic monomer vapor or mist-like acrylic monomer 100, 100C: Organic EL display device 200: Film forming device

Claims (9)

An organic EL device manufacturing method comprising:
The organic EL device includes a substrate, a plurality of TFTs formed on the substrate, a plurality of gate bus lines and a plurality of source bus lines each connected to one of the plurality of TFTs, and a plurality of terminals. And a plurality of lead wirings connecting the plurality of terminals and the plurality of gate bus lines or the plurality of source bus lines, and formed on the driving circuit layer, and at least the An inorganic protective layer exposing a plurality of terminals, an organic planarization layer formed on the inorganic protective layer, and a plurality of layers formed on the organic planarization layer, each connected to one of the plurality of TFTs An organic EL element layer having the organic EL element, and a thin-film sealing structure formed so as to cover the organic EL element layer,
The manufacturing method includes:
Forming the drive circuit layer on the substrate;
Forming the inorganic protective layer on the drive circuit layer;
Forming the organic planarization layer on the inorganic protective layer; and
A step D of reducing moisture contained in the organic planarization layer;
After the step D, including the step E of forming the organic EL element layer on the organic planarization layer,
A manufacturing method further comprising a step C1 of forming an organic polymer film covering the organic planarization layer after the step C and before the step D, and a step C2 of removing the organic polymer film. .   The said process D is a manufacturing method of Claim 1 including the process heated under reduced pressure or atmospheric pressure.   The said process D is a manufacturing method of Claim 1 or 2 performed in the atmosphere of dry air or dry nitrogen whose dew point is -50 degrees C or less.   The step C1 includes a step of providing a solution containing the water-soluble polymer and an aqueous solvent on the organic planarization layer, and a step of volatilizing the aqueous solvent contained in the solution at 100 ° C. or lower. The manufacturing method in any one of Claim 1 to 3.   The manufacturing method according to claim 4, wherein the aqueous solvent contains methanol or ethanol.   The production method according to claim 4 or 5, wherein the water-soluble polymer is polyvinyl alcohol.   The said organic planarization layer is a manufacturing method in any one of Claim 1 to 6 formed from resin which has photosensitivity.   The said organic planarization layer is a manufacturing method in any one of Claim 1 to 7 formed from the polyimide. The manufacturing method according to any one of claims 1 to 8, further comprising a step of storing or transporting the substrate on which the organic polymer film is formed between the step C1 and the step C2.

Images