JP2006024421A - Electro-optical device and manufacturing method of electro-optical device, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electro-optic device restraining infiltration of moisture caused by exfoliation or crack on a gas barrier layer, and its manufacturing method as well as an electronic apparatus. <P>SOLUTION: Stress concentration on the gas barrier layer is alleviated by flattening a foundation of the gas barrier layer. The electro-optical device 1 having a plurality of first electrodes 23; barrier ribs 221 with a plurality of openings 221a corresponding to formation positions of the first electrodes 23; an electro-optical layer 60 arranged for each opening 221a; and second electrodes 50 covering the barrier ribs 221 and the electro-optical layers 60 is also provided with an organic buffer layer 210a covering the second electrodes 50 and with a flat top face formed; an inorganic buffer layer 210b covering the organic buffer layer 210a and formed with a wider area than the organic buffer layer 210a; and the gas barrier layer 30 covering the inorganic buffer layer 210b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electro-optical device, a manufacturing method thereof, and an electronic apparatus including the electro-optical device.

  In recent years, as an electro-optical device, an organic EL device including a light emitting functional layer is known. Such an electro-optical device generally has a configuration in which an organic light emitting layer is provided between an inorganic anode and an inorganic cathode. Furthermore, in order to improve the hole injection property and the electron injection property, an organic hole injection layer is disposed between the inorganic anode and the organic light emitting layer, or an electron injection layer is disposed between the organic light emitting layer and the inorganic cathode. A proposed configuration has been proposed.

Here, an electron injection layer having material characteristics that easily emit electrons easily reacts with moisture present in the atmosphere. By reacting with water, the electron injection effect decreases, and a non-light emitting region called a dark spot is formed. As a result, the lifetime of the light emitting element is shortened. Therefore, in the field of such an electro-optical device, improvement in durability against moisture, oxygen, and the like is a problem.
In order to solve such a problem, a method of sealing moisture or the like by attaching a glass or metal lid to a substrate of a display device has been generally employed. However, as the display becomes larger and thinner / lighter, it is necessary to switch from a hollow structure to a solid structure in order to maintain panel strength that can withstand external stress. In addition, it has been proposed to use a top emission structure that emits light from the opposite side of the circuit board in order to sufficiently secure the area of the TFT and wiring circuit as the size increases. In order to achieve these requirements, the sealing structure must be transparent, lightweight, and have a thin structure with excellent strength resistance. In addition, a structure that provides moisture-proof performance without the desiccant. Is required.

Therefore, in recent years, in order to cope with an increase in size and thickness of a display device, a thin film of silicon nitride, silicon oxide, ceramics, etc. that is transparent and has excellent gas barrier properties on a light emitting element is formed by a high-density plasma deposition method ( For example, a technique called thin film sealing in which film formation is performed by ion plating, ECR plasma sputtering, ECR plasma CVD, surface wave plasma CVD, ICP-CVD, or the like is used (for example, Patent Documents 1 to 4). According to such a technique, it is possible to form a thin film by completely blocking moisture.
JP-A-9-185994 Japanese Patent Laid-Open No. 2001-284041 JP 2000-223264 A JP 2003-17244 A

However, even when such a technique is adopted, it has been confirmed by the present inventor that moisture enters from the outside and sufficient light emission characteristics and light emission life cannot be obtained.
The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an electro-optical device, a manufacturing method thereof, and an electronic apparatus that suppress the invasion of moisture to be peeled off from a gas barrier layer and cracks.

  Since the thin layer (gas barrier layer) formed by the above-described technique is a dense and extremely hard film, the present inventors have found that if there are irregularities or steep steps on the surface on which the thin layer is coated, It has been found that external stress concentrates on the thin film layer to cause cracks and peeling, and on the contrary, the barrier property is lowered. In particular, when a partition called a bank is provided to divide a plurality of light-emitting layers, the surface on which the gas barrier layer is coated is formed in an uneven shape due to the presence of the bank. And found that peeling occurs.

Furthermore, the present inventors have found that moisture enters from the edge portion of the gas barrier layer.
Specifically, at the edge portion of the gas barrier layer, the gas barrier layer is in contact with the substrate while having a gentle slope. When the gas barrier layer is densely formed at such a contact portion, a crack occurs in the gas barrier layer, and moisture enters from there. Here, cracks occur because the gas barrier layer itself has a dense film quality to obtain a gas barrier property such as water vapor, so that a force for pressing the substrate in the gas barrier layer is generated, in other words, the gas barrier layer. This is due to the fact that compressive stress is generated and the gas barrier layer is peeled off from the substrate. Such a crack is likely to occur particularly in a peripheral edge portion having a step. In order to suppress such cracks, it is conceivable to reduce the generation of compressive stress by making the gas barrier layer thinner. However, if the gas barrier layer is made thinner, it is easily affected by fine irregularities on the surface. Hole defects are also likely to occur. That is, it is necessary to form the gas barrier layer with a predetermined thickness in order to fill the unevenness of the base of the gas barrier layer.
As described above, the present inventors have found a problem when the gas barrier layer is made thicker and a problem when the gas barrier layer is made thinner, and only by forming a dense and high-stress gas barrier layer, the intrusion of moisture. It was found that it cannot be suppressed.
Therefore, the present inventors have arrived at the present invention having the following means based on the above.

  In other words, the electro-optical device of the present invention has a plurality of first electrodes, a partition wall having a plurality of openings corresponding to positions where the first electrodes are formed, and an electric circuit disposed on each of the openings. An electro-optical device having an optical layer and a second electrode that covers the partition wall and the electro-optical layer, an organic buffer layer that covers the second electrode and has a substantially flat upper surface, and the organic buffer layer An inorganic buffer layer that covers and covers a larger area than the organic buffer layer and a gas barrier layer that covers the inorganic buffer layer are provided.

Here, the gas barrier layer is made of an inorganic material, and is particularly preferably a silicon compound.
The inorganic buffer layer preferably has a smaller film density than the gas barrier layer. The inorganic buffer layer is more preferably made of the same silicon compound as the gas barrier layer.
In addition, each of the gas barrier layer and the inorganic buffer layer in the present invention means a portion having a gas barrier function (layer film) and a portion having a buffer function against stress (layer film), and is disposed via an interface. It may be a portion, or may be a portion arranged with a concentration gradient of constituent atoms of the gas barrier layer and the inorganic buffer layer. Here, in the case of having the latter concentration gradient, the gas barrier layer and the inorganic buffer layer are defined depending on the concentration of the constituent atoms.

  In general, the gas barrier layer has a compressive stress that works to lift the center of the substrate as described above, and the organic buffer layer has a tensile stress that works to pull up the periphery of the substrate because it is made of an organic material. ing. Therefore, the inorganic buffer layer on the organic buffer layer side is preferably a film having a smaller tensile stress than the organic buffer layer, and the inorganic buffer layer on the gas barrier layer side is preferably a film having a smaller compressive stress than the gas barrier layer. In addition, by reducing the difference in stress between the inorganic buffer layer and the organic buffer layer on the organic buffer layer side or between the inorganic buffer layer and the gas barrier layer on the gas barrier layer side, the adhesion of these layers is improved. be able to. Therefore, the inorganic buffer layer is preferably formed stepwise or continuously from the tensile stress to the compressive stress from the organic buffer layer side toward the gas barrier layer side.

In this way, the gas barrier layer made of an inorganic material and the inorganic buffer layer are in contact with each other, and since the inorganic buffer layer has a smaller film density than the gas barrier layer, the compressive stress when the gas barrier layer is formed is alleviated. Is done. Thereby, peeling and cracking of the gas barrier layer can be suppressed. Therefore, the intrusion of moisture can be suppressed and the electro-optic layer can be prevented from deteriorating.
Moreover, since both the gas barrier layer and the inorganic buffer layer are made of an inorganic material, the adhesiveness between the two is high, and they do not peel from each other. By forming both the gas barrier layer and the inorganic buffer layer from a silicon compound, the adhesion between them can be further improved. Further, by providing such an inorganic buffer layer, the thickness of the gas barrier layer can be made thinner than before. Thereby, the curvature of a base | substrate at the time of forming a gas barrier layer in a thick film can be suppressed. In addition, if the gas barrier layer is simply thinned, film defects such as pinholes occur and generally the barrier property against moisture is lowered. However, by forming the inorganic buffer layer as described above, In addition, since the inorganic buffer layer complements the moisture shielding property, the moisture can be sufficiently shielded even if the gas barrier layer is a thin film.

Further, since the inorganic buffer layer is formed with a larger area than the organic buffer layer, the organic buffer layer is covered with the inorganic buffer layer. As a result, the gas barrier layer and the organic buffer layer are not in direct contact. Thereby, the stress which arises between a gas barrier layer and an organic buffer layer is relieved, and peeling and a crack of a gas barrier layer can be suppressed.
In addition, by providing the organic buffer layer, the flattening of the partition wall, the warpage generated from the substrate side, and the stress generated by the volume change are dispersed, thereby preventing cracks and peeling occurring in the inorganic buffer layer and the gas barrier layer. Further, by providing the organic buffer layer, it is possible to prevent the second electrode from peeling from the unstable partition. In addition, since the upper surface of the organic buffer layer is substantially flattened, the inorganic buffer layer and gas barrier layer formed on the organic buffer layer are flattened, and there is no portion where stress concentration occurs in the gas barrier layer, and cracks in the gas barrier layer occur. Can be prevented.
Further, since the organic buffer layer fills in fine particles that adhere after the second electrode is formed, even if the particles are present, the inorganic buffer layer and the gas barrier layer can be planarized.

In the electro-optical device, the inorganic buffer layer contains oxygen atoms.
As described above, since oxygen atoms enter the inside of the inorganic buffer layer, the density of the inorganic buffer layer is lowered, so that the compressive stress of the gas barrier layer can be effectively relieved.
In particular, when the inorganic buffer layer and the gas barrier layer are formed of a silicon compound, by making the oxygen content of the inorganic buffer layer larger than the oxygen content of the gas barrier layer, the compressive stress of the inorganic buffer layer is made higher than the compressive stress of the gas barrier layer. Can be kept small.
In addition, when the inorganic buffer layer contains oxygen atoms, the refractive index of the inorganic buffer layer changes compared to the case where the inorganic buffer layer does not contain oxygen atoms. Therefore, by adjusting the content of oxygen atoms, the inorganic buffer layer can be adjusted to have a desired refractive index, that is, a desired film density.

In the electro-optical device, the inorganic buffer layer contains hydrogen atoms.
As described above, since the hydrogen atoms enter the inside of the inorganic buffer layer, the density of the inorganic buffer layer is reduced, so that the compressive stress of the gas barrier layer can be effectively relieved. In particular, when the inorganic buffer layer and the gas barrier layer are formed of a silicon compound, by making the hydrogen content of the inorganic buffer layer larger than the hydrogen content of the gas barrier layer, the compressive stress of the inorganic buffer layer is made higher than the compressive stress of the gas barrier layer. And can be controlled in a range from compressive stress to tensile stress by controlling the hydrogen content of the inorganic buffer layer. By reducing the hydrogen content of the inorganic buffer layer continuously or stepwise from the organic buffer layer side to the gas barrier layer side, the stress of the inorganic buffer layer is directed from the organic buffer layer side to the gas barrier layer side. To compressive stress in a stepwise or continuous manner.
Further, even if the inorganic buffer layer contains hydrogen atoms, the refractive index of the inorganic buffer layer does not change, so that the denseness of the film quality can be adjusted without changing the refractive index.

In the electro-optical device, the inorganic buffer layer is formed to cover the organic buffer layer and to be in contact with an inorganic material on a substrate.
If it does in this way, a gas barrier layer will be formed on an inorganic material via an inorganic buffer layer, without a gas barrier layer contacting directly with an inorganic material on a substrate. Therefore, since the compressive stress of the gas barrier layer is relieved by the inorganic buffer layer, it is possible to suppress peeling and cracking of the gas barrier layer in the inorganic material forming portion on the substrate. Accordingly, moisture intrusion due to the peeling or cracking can be suppressed.

In the electro-optical device, a resin adhesive layer that covers the gas barrier layer and a protective substrate that covers the resin adhesive layer are provided.
In this way, since the gas barrier layer is protected, the destruction and damage of the gas barrier layer can be suppressed.

Further, the electro-optical device is characterized in that an electrode protective layer is provided between the second electrode and the organic buffer layer.
In this way, the second electrode is protected by the electrode protection layer, so that damage due to the organic solvent and residual moisture when forming the organic buffer layer can be suppressed.

In the electro-optical device, the inorganic buffer layer is formed to cover the organic buffer layer and to be in contact with the electrode protective layer.
If it does in this way, a gas barrier layer will be formed on an electrode protective layer via an inorganic buffer layer, without a gas barrier layer contacting directly with an electrode protective layer. Therefore, since the compressive stress of the gas barrier layer is relieved by the inorganic buffer layer, peeling and cracking of the gas barrier layer formed on the electrode protective layer can be suppressed. Accordingly, moisture intrusion due to the peeling or cracking can be suppressed.

The electro-optical device is characterized in that the angle of the side end portion of the organic buffer layer is 45 ° or less.
Here, the inorganic buffer layer and the gas barrier layer are formed following the shape of such an organic buffer layer. In this way, since the inorganic buffer layer and the gas barrier layer have a gentle shape rather than a steep shape, the stress in the inorganic buffer layer and the gas barrier layer can be reduced. Therefore, even if a load is applied to the inorganic buffer layer or the gas barrier layer, peeling or cracking does not occur, and entry of moisture can be suppressed.

  In the method of manufacturing the electro-optical device according to the aspect of the invention, a plurality of first electrodes, a partition wall having a plurality of openings corresponding to positions where the first electrodes are formed, and a plurality of openings are disposed on the substrate. Forming a substantially flat organic buffer layer while covering the second electrode in a method of manufacturing an electro-optical device, and a second electrode that covers the partition wall and the electro-optical layer; The method includes a step of forming an inorganic buffer layer that covers the organic buffer layer and has a larger area than the organic buffer layer, and a step of forming a gas barrier layer that covers the inorganic buffer layer.

  Thus, by forming an inorganic buffer layer, the compressive stress of a gas barrier layer is relieve | moderated and peeling and a crack of a gas barrier layer can be suppressed. Therefore, the intrusion of moisture can be suppressed and the electro-optic layer can be prevented from deteriorating. Further, by forming the inorganic buffer layer, the thickness of the gas barrier layer can be made thinner than before. Thereby, the curvature of a base | substrate at the time of forming a gas barrier layer in a thick film can be suppressed. Further, since the inorganic buffer layer complements the moisture shielding property, the moisture can be sufficiently shielded even if the gas barrier layer is a thin film.

Moreover, since the inorganic buffer layer is formed in a larger area than the organic buffer layer, the gas barrier layer and the organic buffer layer do not come into direct contact. Thereby, the stress which arises between a gas barrier layer and an organic buffer layer is relieved, and peeling and a crack of a gas barrier layer can be suppressed.
Further, by forming the organic buffer layer, it is possible to relieve the warp generated from the substrate side and the stress generated by the volume change. Therefore, peeling of the second electrode from the unstable partition can be prevented. In addition, since the upper surface of the organic buffer layer is substantially flattened, the inorganic buffer layer and gas barrier layer formed on the organic buffer layer are flattened, and there is no portion where stress concentration occurs in the gas barrier layer, and cracks in the gas barrier layer occur. Can be prevented.
Further, since the organic buffer layer fills in fine particles that adhere after the second electrode is formed, even if the particles are present, the inorganic buffer layer and the gas barrier layer can be planarized.

In the method of manufacturing the electro-optical device, the step of forming the organic buffer layer uses a liquid phase method under an atmospheric pressure atmosphere.
In this way, an organic buffer layer excellent in flatness can be formed inexpensively and easily compared with the case where it is formed in a vacuum atmosphere.

In the method of manufacturing the electro-optical device, the step of forming the inorganic buffer layer and the gas barrier layer is continuously performed in a vacuum atmosphere.
In this way, since the inorganic buffer layer and the gas barrier layer are formed without returning to the atmospheric pressure atmosphere, productivity can be improved. In addition, when returning to the air atmosphere, moisture contained in the air enters between the inorganic buffer layer and the gas barrier layer, but moisture can be suppressed by forming a film in the same vacuum atmosphere.

According to another aspect of the invention, an electronic apparatus includes the electro-optical device described above.
Examples of such electronic devices include mobile phones, mobile information terminals, watches, word processors, information processing devices such as personal computers, printers, and the like. Further, a television having a large display screen, a large monitor, and the like can be exemplified. Thus, by employing the electro-optical device of the present invention for the display unit of an electronic device, an electronic device having a display unit with a long life and good display characteristics can be provided. Moreover, you may apply to light sources, such as a printer.

Hereinafter, embodiments of an electro-optical device, a method for manufacturing the electro-optical device, and an electronic apparatus according to the present invention will be described with reference to the drawings.
As an electro-optical device, an EL display device using an electroluminescent material as an example of an electro-optical material, in particular, an organic electroluminescence (EL) material will be described.
FIG. 1 is a diagram showing a wiring structure of the EL display device 1. The EL display device 1 is an active matrix EL display device using a thin film transistor (hereinafter abbreviated as TFT) as a switching element.
In the following description, each scale and each layer film constituting the EL display device 1 are made different in scale so that they can be recognized.

As shown in FIG. 1, the EL display device (electro-optical device) 1 includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction perpendicular to each scanning line 101, and each signal line 102. And a plurality of power supply lines 103 extending in parallel with each other, and a pixel region X is provided in the vicinity of each intersection of the scanning line 101 and the signal line 102.
A data line driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, a scanning line driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.

  Further, in each pixel region X, a switching TFT 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101 and a pixel signal to be supplied from the signal line 102 via the switching TFT 112 are held. A capacitor 113, a driving TFT 123 to which a pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and driving from the power line 103 when electrically connected to the power line 103 through the driving TFT 123 A pixel electrode (first electrode) 23 into which a current flows and a functional layer 110 sandwiched between the pixel electrode 23 and a cathode (second electrode) 50 are provided. The pixel electrode 23, the cathode 50, and the functional layer 110 constitute a light emitting element (organic EL element).

  According to the EL display device 1, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor 113, and according to the state of the holding capacitor 113. The on / off state of the driving TFT 123 is determined. Then, current flows from the power supply line 103 to the pixel electrode 23 through the channel of the driving TFT 123, and further current flows to the cathode 50 through the functional layer 110. The functional layer 110 emits light according to the amount of current flowing through it.

Next, a specific configuration of the EL display device 1 will be described with reference to FIGS.
As shown in FIG. 2, the EL display device 1 includes a pixel electrode in which a substrate 20 having electrical insulation and pixel electrodes connected to switching TFTs (not shown) are arranged in a matrix on the substrate 20. An area (not shown), a power line (not shown) arranged around the pixel electrode area and connected to each pixel electrode, and a pixel portion 3 having a substantially rectangular shape in plan view located at least on the pixel electrode area (In the dashed-dotted line frame in FIG. 2).
In the present invention, the substrate 20 and the switching TFT and various circuits formed on the substrate 20 as will be described later, and an interlayer insulating film are referred to as a base. (Indicated by reference numeral 200 in FIGS. 3 and 4)

The pixel unit 3 includes a real display area 4 in the center (inside the two-dot chain line in FIG. 2) and a dummy area 5 (area between the one-dot chain line and the two-dot chain line) arranged around the real display area 4. It is divided into.
In the actual display area 4, display areas R, G, and B each having a pixel electrode are arranged in a matrix so as to be separated from each other in the AB direction and the CD direction.
Further, scanning line drive circuits 80 and 80 are arranged on both sides of the actual display area 4 in FIG. These scanning line drive circuits 80 and 80 are arranged below the dummy region 5.

  Further, an inspection circuit 90 is arranged above the actual display area 4 in FIG. The inspection circuit 90 is a circuit for inspecting the operating state of the EL display device 1 and includes, for example, inspection information output means (not shown) for outputting the inspection result to the outside, and is displayed during manufacture or at the time of shipment. The apparatus is configured to be able to inspect the quality and defect of the apparatus. The inspection circuit 90 is also disposed below the dummy area 5.

  The scanning line driving circuit 80 and the inspection circuit 90 are applied with a driving voltage from a predetermined power supply unit via the driving voltage conducting unit 310 (see FIG. 3) and the driving voltage conducting unit 340 (see FIG. 4). Composed. Further, the drive control signal and drive voltage to the scanning line drive circuit 80 and the inspection circuit 90 are supplied from a predetermined main driver for controlling the operation of the EL display device 1 and the drive control signal conduction unit 320 (see FIG. 3) and Transmission and application are performed via the drive voltage conduction unit 350 (see FIG. 4). The drive control signal in this case is a command signal from a main driver or the like related to control when the scanning line drive circuit 80 and the inspection circuit 90 output signals.

In addition, as shown in FIGS. 3 and 4, the EL display device 1 has a large number of light emitting elements (organic EL elements) each including a pixel electrode 23, a light emitting layer 60, and a cathode 50 on a base 200, The organic buffer layer 210a, the inorganic buffer layer 210b, the gas barrier layer 30 and the like are formed so as to cover them.
The light emitting layer 60 is typically a light emitting layer (electroluminescence layer), and includes a carrier injection layer or a carrier transport layer such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. thing. Furthermore, a hole blocking layer (hole blocking layer) and an electron blocking layer (electron blocking layer) may be provided.

  In the case of a so-called top emission type EL display device, the substrate 20 constituting the base body 200 is configured to extract emitted light from the gas barrier layer 30 side, which is the opposite side of the substrate 20, so that either a transparent substrate or an opaque substrate is used. Can also be used. Examples of opaque substrates include ceramics such as alumina, metal sheets such as stainless steel that have been subjected to insulation treatment such as surface oxidation, thermosetting resins and thermoplastic resins, and films thereof (plastic films). It is done.

  In the case of a so-called bottom emission type EL display device, since the emitted light is extracted from the substrate 20 side, a transparent or semi-transparent substrate 20 is employed. For example, glass, quartz, resin (plastic, plastic film) and the like can be mentioned, and a glass substrate is particularly preferably used. In the present embodiment, the top emission type in which emitted light is extracted from the gas barrier layer 30 side, and therefore the above-described opaque substrate such as an opaque plastic film is used as the substrate 20.

A circuit unit 11 including a driving TFT 123 for driving the pixel electrode 23 and the like is formed on the substrate 20, and a large number of light emitting elements (organic EL elements) are provided thereon. As shown in FIG. 6, the light emitting element includes a pixel electrode 23 that functions as an anode, a hole transport layer 70 that injects / transports holes from the pixel electrode 23, and an organic EL that is one of electro-optical materials. The light-emitting layer 60 including the substance and the cathode 50 are sequentially formed.
Based on such a configuration, the light emitting element emits light by combining holes injected from the hole transport layer 70 and electrons from the cathode 50 in the light emitting layer 60.

Since the pixel electrode 23 is a top emission type in this embodiment, it does not need to be transparent, and is therefore formed of an appropriate conductive material.
As a material for forming the hole transport layer 70, for example, a polythiophene derivative, a polypyrrole derivative, or a doped body thereof is used. Specifically, 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS) dispersion, that is, 3,4-polyethylenediosithiophene is dispersed in polystyrene sulfonic acid as a dispersion medium. The hole transport layer 70 can be formed using a dispersion liquid in which is dispersed in water.

As a material for forming the light emitting layer 60, a known light emitting material capable of emitting fluorescence or phosphorescence can be used. Specifically, (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), polyvinyl carbazole (PVK), polythiophene derivative, polymethyl Polysilanes such as phenylsilane (PMPS) are preferably used.
In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as.
In addition, it replaces with the polymeric material mentioned above, a conventionally well-known low molecular material can also be used.
In addition, an electron injection layer may be formed on the light emitting layer 60 as necessary.

In the present embodiment, the hole transport layer 70 and the light emitting layer 60 are composed of a lyophilic control layer 25 and an organic partition layer (partition wall) formed in a lattice shape on the substrate 200 as shown in FIGS. ) 221 and the hole transport layer 70 and the light emitting layer 60 surrounded by this become an element layer constituting a single light emitting element (organic EL element).
Note that the angle θ of each wall surface of the opening 221a of the organic partition wall layer 221 with respect to the surface of the base body 200 is 110 degrees or more and 170 degrees or less (see FIG. 6). The reason for this angle is to facilitate the arrangement of the light emitting layer 60 in the opening 221a when the light emitting layer 60 is formed by a wet process.

  As shown in FIGS. 3 to 6, the cathode 50 has a larger area than the total area of the actual display region 4 and the dummy region 5, and is formed so as to cover each, and the light emitting layer 60 and the organic partition layer 221. These are formed on the base body 200 in a state of covering the upper surface and the wall surface forming the outer portion of the organic partition wall layer 221. The cathode 50 is connected to a cathode wiring 202 formed on the outer periphery of the substrate 200 outside the organic partition layer 221 as shown in FIG. A flexible substrate 203 is connected to the cathode wiring 202, whereby the cathode 50 is connected to a driving IC (driving circuit) (not shown) on the flexible substrate 203 via the cathode wiring 202.

  As a material for forming the cathode 50, since this embodiment is a top emission type, it needs to be light transmissive, and therefore, a transparent conductive material is used. As the transparent conductive material, ITO (Indium Tin Oxide: Indium Tin Oxide) is suitable, but other than this, for example, indium oxide / zinc oxide based amorphous transparent conductive film (Indium Zinc Oxide: IZO / I-Zet) O) (registered trademark) or the like can be used. In the present embodiment, ITO is used.

  The cathode 50 is preferably made of a material having a large electron injection effect. For example, calcium, magnesium, sodium, lithium metal, or a metal compound thereof. Examples of the metal compound include metal fluorides such as calcium fluoride, metal oxides such as lithium oxide, and organometallic complexes such as acetylacetonato calcium. In addition, these materials alone have a large electrical resistance and do not function as an electrode, so they are used in combination with a laminate of a metal layer such as aluminum, gold, silver, or copper, or a metal oxide conductive layer such as ITO or tin oxide. Also good. In this embodiment, a laminate of lithium fluoride, magnesium metal, and ITO is used by adjusting the film thickness to obtain transparency.

A cathode protective layer (electrode protective layer) 55 is formed on the upper layer portion of the cathode 50. The cathode protective layer 55 is provided to prevent corrosion and damage of the cathode 50 during the manufacturing process due to an organic solvent, residual moisture, and the like when the organic buffer layer 210a is formed. Further, such a cathode protective layer 55 is preferably made of a material that hardly generates compressive stress after formation, and is preferably formed of an inorganic compound such as a silicon compound or a metal compound such as titanium oxide. More preferably, the material is the same as that of the inorganic buffer layer 210b. Further, as a method for forming the cathode protective layer 55, a high-density plasma film forming method, a vacuum deposition method, or the like is used. The film thickness is preferably 30 to 100 nm.
The cathode protective layer 55 is formed to a thickness of about 10 nm to 300 nm up to the insulating layer 284 on the outer peripheral portion of the substrate 200.

  An organic buffer layer 210 a is provided in an upper layer portion of the cathode protective layer 55 in a range wider than the organic partition layer 221 and covering the cathode 50. The organic buffer layer 210a is arranged so as to fill the convex and concave portions of the cathode 50 formed in a convex and concave shape due to the influence of the shape of the organic partition wall layer 221, and the upper surface thereof is formed substantially flat.

The organic buffer layer 210a has a function of relieving the warp generated from the substrate 200 side and the stress generated by volume expansion and preventing the cathode 50 from peeling from the unstable organic partition layer 221. Further, since the upper surface of the organic buffer layer 210a is substantially flattened, the gas barrier layer 30 made of a hard film formed on the organic buffer layer 210a is also flattened, so that there is no portion where stress is concentrated. Generation of cracks in the gas barrier layer 30 is prevented.
As the organic buffer layer 210a, a polymer material having lipophilicity and low water absorption, for example, a polyolefin type or a polyether type is preferable. Alternatively, an organosilicon polymer obtained by hydrolyzing and condensing alkoxysilane such as methyltrimethoxysilane or tetraethoxysilane may be used. In addition, polymer derivatives and bisphenol-based epoxies and amine compounds polymerized with isocyanate compounds such as tolylene diisocyanate and xylylene diisocyanate, which are mainly composed of acrylic polyol, methacryl polyol, polyester polyol, polyether polyol, and polyurethane polyol. A polymer derivative or the like may be employed.
Furthermore, by using a polymer containing a silicon compound such as a silane coupling agent such as 3-aminopropyltrimethoxysilane or 3-glycidoxypropyltrimethoxysilane, an inorganic material such as the cathode 50 or the gas barrier layer 30 can be used. The adhesion at the interface can be improved.
The organic buffer layer 210a is preferably a material that cures at a low temperature, and an ultraviolet curable resin mainly composed of a methacrylate resin or an epoxy resin can also be used. By using the ultraviolet curable resin, the organic buffer layer 210a is formed without performing a heat treatment, so that adverse effects on the light emitting layer 60 due to heating can be suppressed. In this case, it is desirable that the cathode protective layer 55 be formed of an ultraviolet absorbing material. For example, an oxide having an energy band gap of 2 to 4 eV such as titanium oxide, zinc oxide, or indium tin oxide (ITO). Since the semiconductor material is used for at least a part of the cathode protective layer, the ultraviolet light transmitted through the organic buffer layer 210a is absorbed by the cathode protective layer 55, so that the ultraviolet light applied to the organic buffer layer 210a has an adverse effect on the light emitting layer 60. Prevent giving. Further, additives such as fine particles for preventing curing shrinkage may be mixed.
These organic buffer layer materials are applied and formed by diluting with an oleophilic organic solvent or the like so as to be adjusted to a viscosity range in which flat coating is easy. These organic solvents are removed by drying under reduced pressure after application.

Here, the structure of the end of the organic buffer layer 210a will be described with reference to FIG.
FIG. 5 is an enlarged view showing an end portion of the organic buffer layer 210a in FIG. As shown in FIG. 5, the organic buffer layer 210 a is formed on the cathode protective layer 55, and is in contact with the surface of the cathode protective layer 55 at the contact angle α at the end thereof. Here, the contact angle α is 45 ° or less, and more preferably about 10 ° to 20 °. By forming the organic buffer layer 210a in this way, the inorganic buffer layer 210b and the barrier layer 30 formed on the organic buffer layer 210a are formed following the shape of the organic buffer layer 210a.

Further, an inorganic buffer layer 210b is formed on the upper layer portion of the organic buffer layer 210a.
The inorganic buffer layer 210b is made of a material having a lower film density and a smaller compressive stress than the gas barrier layer 30, that is, a low density. For example, a material that is chemically stable and excellent in adhesion to an organic material, such as silicon nitrogen oxide and aluminum oxide, is preferably used as a main component. Further, as the material, a material that can obtain good adhesion to the organic buffer layer 210a and the gas barrier layer 30 is appropriately adopted.
In general, the gas barrier layer 30 needs to be dense in order to impart gas barrier properties, and has compressive stress. The organic buffer layer has a small tensile stress because it is formed by polymerizing an organic material. Accordingly, the inorganic buffer layer 210b is formed stepwise or continuously from the tensile stress to the compressive stress from the organic buffer layer 210a side to the gas barrier layer 30 side, so that the inorganic buffer layer 210b and the organic buffer layer 210a or In addition, the adhesion between the inorganic buffer layer 210b and the gas barrier layer 30 can be improved. In order to improve the adhesion with the gas barrier layer 30, it is preferable to use the same silicon-based material as the gas barrier layer 30. Specifically, silicon oxide or silicon oxynitride is employed. Here, it is preferable that the oxygen and nitrogen contents are made different from those of the gas barrier layer 30 to adjust the compressive stress during film formation. The gas barrier layer 30 and the inorganic buffer layer 210b are both formed of silicon oxide or silicon oxynitride, and the compressive stress is reduced by making the oxygen content of the inorganic buffer layer 210b larger than the oxygen content of the gas barrier layer 30. Can be made.
The inorganic buffer layer 210b is preferably a relatively amorphous film or a porous film so as not to generate a compressive stress. Hydrogen atoms are introduced into the film so as to break the covalent bond. Various structures may be used. Further, oxygen atoms may be introduced into the film together with hydrogen atoms. The gas barrier layer 30 and the inorganic buffer layer 210b are both formed of silicon oxide or silicon oxynitride, and the compressive stress is reduced by making the hydrogen content of the inorganic buffer layer 210b larger than the hydrogen content of the gas barrier layer 30. Can be made.
In addition, the inorganic buffer layer 210b on the organic buffer layer 210a side is formed of an organic silane such as silicone resin or silazane, whereby the adhesion between the inorganic buffer layer 210b and the gas barrier layer 30 can be further improved.
The inorganic buffer layer 210b is preferably formed with a larger area than the organic buffer layer 210a. As a result, the organic buffer layer 210a is covered with the inorganic buffer layer 210b.

Further, the gas barrier layer 30 is formed on the upper layer portion of the inorganic buffer layer 210b.
The gas barrier layer 30 is formed on the inorganic buffer layer 210b without contacting the insulating layer 284. The gas barrier layer 30 is for preventing oxygen and moisture from entering inside thereof, thereby preventing the entry of oxygen and moisture into the cathode 50 and the light emitting layer 60, and the cathode 50 and light emission due to oxygen and moisture. The deterioration of the layer 60 is suppressed.
The gas barrier layer 30 is made of, for example, an inorganic compound, and is preferably formed of a silicon compound, that is, silicon nitride, silicon oxynitride, silicon oxide, or the like. Furthermore, it is necessary to form a dense and defect-free film in order to block off gas such as water vapor, and it is preferably formed using a high-density plasma film forming method capable of forming a dense film at a low temperature. By forming the gas barrier layer 30 from the same silicon compound as the inorganic buffer layer in this way, the adhesion between the gas barrier layer 30 and the inorganic buffer layer 210b is improved, and therefore the gas barrier layer 30 becomes a dense layer without defects. The barrier property against oxygen and moisture becomes better. However, other than silicon compounds, for example, alumina, tantalum oxide, titanium oxide, and other ceramics may be used.

Furthermore, the gas barrier layer 30 may have a laminated structure, or may have a composition in which the composition is non-uniform and the oxygen concentration changes continuously or discontinuously, for example, an inorganic buffer layer. When 210b is silicon oxide, it is preferable to increase the oxygen concentration on the interface side to be bonded for the reason described above.
Further, the thickness of the gas barrier layer 30 is preferably 10 nm or more and 200 nm or less. If it is less than 10 nm, through holes may be partially formed due to film defects or film thickness variations, and the gas barrier property may be impaired. If it exceeds 200 nm, cracks due to stress occur. This is because it may occur. From the same problem, the total film thickness of the inorganic buffer layer and the gas barrier layer is preferably 500 nm or less.
In addition, since the top emission type is used in the present embodiment, the gas barrier layer 30 needs to have translucency. Therefore, by adjusting the material and film thickness appropriately, the light beam in the visible light region can be obtained in the present embodiment. The transmittance is set to 80% or more, for example.

  In addition, each of said inorganic buffer layer 210b and the gas barrier layer 30 does not necessarily need to be joined by the interface. For example, the inorganic buffer layer 210b and the gas barrier layer 30 may be formed from the same layer film having no interface. In this case, a structure in which the concentration of the constituent molecules is gradually changed from the organic buffer layer 210a side to the protective layer 204 side in the same layer film, that is, a layer film having a concentration gradient is preferable. Specifically, a silicon compound is formed on the organic buffer layer 210a, the oxygen atom concentration is high on the organic buffer layer 210a side, the nitrogen concentration is low, and the oxygen atom concentration is low toward the protective layer 204. The structure which makes a nitrogen concentration a high state is mentioned. Thus, the function of the inorganic buffer layer 210b and the gas barrier layer 30 may be included in the same layer film by forming a concentration gradient of oxygen atoms and nitrogen atoms in the same layer film.

Further, a protective layer 204 that covers the gas barrier layer 30 is provided on the upper layer portion of the gas barrier layer 30. The protective layer 204 includes an adhesive layer (resin adhesive layer) 205 and a surface protective substrate (protective substrate) 206 provided on the gas barrier layer 30 side.
The adhesive layer 205 fixes the surface protection substrate 206 on the gas barrier layer 30 and has a buffer function against mechanical shock from the outside, and protects the light emitting layer 60 and the gas barrier layer 30. The protective layer 204 is formed by attaching the surface protective substrate 206 to the adhesive layer 205. The adhesive layer 205 is formed of an adhesive made of a material that is softer than the surface protective substrate 206 and has a lower glass transition point, for example, a resin such as urethane, acrylic, epoxy, or polyolefin. A transparent resin material is preferred. Further, it may be formed of a two-component mixed material in which a curing agent is added for curing at a low temperature.
In addition, it is preferable to add a silane coupling agent or alkoxysilane to such an adhesive layer 205, so that the adhesion between the formed adhesive layer 205 and the gas barrier layer 30 is better. Therefore, the buffer function against mechanical shock is increased.
Further, particularly when the gas barrier layer 30 is formed of a silicon compound, the adhesion with the gas barrier layer 30 can be improved by a silane coupling agent or alkoxysilane, and thus the gas barrier property of the gas barrier layer 30 is improved. be able to.

The surface protective substrate 206 is provided on the adhesive layer 205 and constitutes the surface side of the protective layer 204, and has functions such as pressure resistance, wear resistance, external light antireflection, gas barrier properties, and ultraviolet blocking properties. A layer comprising at least one of the following.
As the material of the surface protection substrate 206, glass, a DLC (Diamond Like Carbon) layer, a transparent plastic, or a transparent plastic film is employed. Here, as the plastic material, for example, PET, acrylic, polycarbonate, polyolefin and the like are employed. Further, the surface protective substrate 206 may be provided with an optical structure such as an ultraviolet blocking / absorbing layer, a light reflection preventing layer, a heat radiating layer, a lens or a mirror.
In the EL display device of this example, when the top emission type is used, both the surface protection substrate 206 and the adhesive layer 205 need to be translucent, but when the bottom emission type is used, this is necessary. There is no.

  Further, a circuit unit 11 is provided below the above-described light emitting element as shown in FIG. The circuit unit 11 is formed on the substrate 20 and constitutes the base body 200. That is, a base protective layer 281 mainly composed of SiO2 is formed on the surface of the substrate 20 and a silicon layer 241 is formed thereon. A gate insulating layer 282 mainly composed of SiO 2 and / or SiN is formed on the surface of the silicon layer 241.

  In addition, a region of the silicon layer 241 that overlaps with the gate electrode 242 with the gate insulating layer 282 interposed therebetween is a channel region 241a. The gate electrode 242 is a part of the scanning line 101 (not shown). On the other hand, a first interlayer insulating layer 283 mainly composed of SiO 2 is formed on the surface of the gate insulating layer 282 that covers the silicon layer 241 and on which the gate electrode 242 is formed.

  Further, in the silicon layer 241, a low concentration source region 241b and a high concentration source region 241S are provided on the source side of the channel region 241a, while a low concentration drain region 241c and a high concentration drain are provided on the drain side of the channel region 241a. The region 241D is provided to form a so-called LDD (Light Doped Drain) structure. Among these, the high-concentration source region 241S is connected to the source electrode 243 through a contact hole 243a that opens over the gate insulating layer 282 and the first interlayer insulating layer 283. The source electrode 243 is configured as a part of the above-described power supply line 103 (see FIG. 1, extending in the direction perpendicular to the paper surface at the position of the source electrode 243 in FIG. 6). On the other hand, the high-concentration drain region 241D is connected to the drain electrode 244 made of the same layer as the source electrode 243 through a contact hole 244a that opens through the gate insulating layer 282 and the first interlayer insulating layer 283.

  The upper layer of the first interlayer insulating layer 283 on which the source electrode 243 and the drain electrode 244 are formed is covered with a second interlayer insulating layer 284 mainly composed of, for example, an acrylic resin component. The second interlayer insulating layer 284 can be made of a material other than an acrylic insulating film, such as SiN or SiO 2. A pixel electrode 23 made of ITO is formed on the surface of the second interlayer insulating layer 284 and is connected to the drain electrode 244 through a contact hole 23 a provided in the second interlayer insulating layer 284. That is, the pixel electrode 23 is connected to the high concentration drain region 241D of the silicon layer 241 through the drain electrode 244.

  Note that TFTs (driving circuit TFTs) included in the scanning line driving circuit 80 and the inspection circuit 90, that is, N-channel type or P-channel type TFTs constituting an inverter included in the shift register among these driving circuits, for example. The structure is the same as that of the driving TFT 123 except that it is not connected to the pixel electrode 23.

On the surface of the second interlayer insulating layer 284 on which the pixel electrode 23 is formed, the pixel electrode 23, the lyophilic control layer 25 and the organic partition layer 221 described above are provided. The lyophilic control layer 25 is mainly composed of a lyophilic material such as SiO 2, and the organic partition layer 221 is made of acrylic, polyimide, or the like. On the pixel electrode 23, the hole transport layer 70 and the light emitting layer 60 are formed inside the opening 25 a provided in the lyophilic control layer 25 and the opening 221 a surrounded by the organic partition wall layer 221. Are stacked in this order. In addition, “lyophilic” of the lyophilic control layer 25 in this embodiment means that the lyophilic property is higher than at least materials such as acrylic and polyimide constituting the organic partition layer 221. .
The layers up to the second interlayer insulating layer 284 on the substrate 20 described above constitute the circuit unit 11.

  Here, in the EL display device 1 of the present embodiment, each light emitting layer 60 is formed so that the light emission wavelength bands correspond to the three primary colors of light in order to perform color display. For example, as the light emitting layer 60, a red light emitting layer 60R whose light emission wavelength band corresponds to red, a green light emitting layer 60G corresponding to green, and a blue organic EL layer 60B corresponding to blue, respectively, are displayed. , G, and B, one pixel that performs color display is configured with the display regions R, G, and B. Further, a BM (black matrix) (not shown) in which metallic chromium is formed by sputtering or the like is formed between the organic partition layer 221 and the lyophilic control layer 25 at the boundary between the color display regions.

Next, an example of a method for manufacturing the EL display device 1 according to the present embodiment will be described with reference to FIGS. Each of the cross-sectional views shown in FIGS. 7 and 8 corresponds to the cross-sectional view taken along line AB in FIG.
In this embodiment, the EL display device 1 as an electro-optical device is a top emission type, and the process of forming the circuit portion 11 on the surface of the substrate 20 is not different from the conventional technique. Description is omitted.

First, as shown in FIG. 7A, a conductive film to be the pixel electrode 23 is formed so as to cover the entire surface of the substrate 20 on which the circuit portion 11 is formed, and this transparent conductive film is further patterned. Thus, the pixel electrode 23 that is electrically connected to the drain electrode 244 through the contact hole 23a of the second interlayer insulating layer 284 is formed, and at the same time, the dummy pattern 26 in the dummy region is also formed.
3 and 4, the pixel electrode 23 and the dummy pattern 26 are collectively referred to as the pixel electrode 23. The dummy pattern 26 is configured not to be connected to the lower metal wiring via the second interlayer insulating layer 284. That is, the dummy pattern 26 is arranged in an island shape and has substantially the same shape as the shape of the pixel electrode 23 formed in the actual display region. Of course, the structure may be different from the shape of the pixel electrode 23 formed in the display region. In this case, the dummy pattern 26 includes at least one located above the drive voltage conduction unit 310 (340).

  Next, as shown in FIG. 7B, a lyophilic control layer 25 that is an insulating layer is formed on the pixel electrode 23, the dummy pattern 26, and the second interlayer insulating film. In the pixel electrode 23, the lyophilic control layer 25 is formed so as to partially open, and holes can be transferred from the pixel electrode 23 in the opening 25a (see also FIG. 3). On the contrary, in the dummy pattern 26 in which the opening 25a is not provided, the insulating layer (lyophilic control layer) 25 serves as a hole movement shielding layer and does not cause hole movement. Subsequently, in the lyophilic control layer 25, a BM (black matrix) (not shown) is formed in a concave portion formed between two different pixel electrodes 23. Specifically, the concave portion of the lyophilic control layer 25 is formed by sputtering using metallic chromium.

  Then, as shown in FIG. 7C, an organic partition layer 221 is formed so as to cover a predetermined position of the lyophilic control layer 25, specifically, the BM described above. As a specific method for forming the organic barrier layer, for example, an organic layer is formed by applying a resist such as an acrylic resin or a polyimide resin dissolved in a solvent by various coating methods such as a spin coating method or a dip coating method. . The constituent material of the organic layer may be any material as long as it does not dissolve in the ink solvent described later and is easily patterned by etching or the like.

Further, the organic layer is patterned using a photolithography technique and an etching technique to form an opening 221a in the organic layer, thereby forming an organic partition layer 221 having a wall surface in the opening 221a. Here, the wall surface forming the opening 221 is formed such that the angle θ with respect to the surface of the base body 200 is 110 degrees or more and 170 degrees or less.
In this case, the organic partition wall layer 221 includes at least the one located above the drive control signal conducting unit 320.

  Next, a region showing lyophilicity and a region showing liquid repellency are formed on the surface of the organic partition layer 221. In the present embodiment, each region is formed by plasma processing. Specifically, in the plasma treatment, the upper surface of the organic partition wall layer 221, the wall surface of the opening 221a, the electrode surface 23c of the pixel electrode 23, and the upper surface of the lyophilic control layer 25 are made lyophilic. The ink making step includes an ink repellent step, an ink repellent step for making the upper surface of the organic partition layer 211 and the wall surface of the opening 221a liquid repellent, and a cooling step.

  That is, the base material (the substrate 20 including the partition walls) is heated to a predetermined temperature, for example, about 70 to 80 ° C., and then a plasma treatment (O 2 plasma treatment) using oxygen as a reactive gas in an atmospheric atmosphere as an ink-philic process. Do. Next, a plasma treatment (CF4 plasma treatment) using methane tetrafluoride as a reactive gas is performed in an air atmosphere as an ink repellent process, and then the substrate heated for the plasma treatment is cooled to room temperature. The lyophilic property and the liquid repellency are imparted to a predetermined location.

  In this CF4 plasma treatment, the electrode surface 23c of the pixel electrode 23 and the lyophilic control layer 25 are also somewhat affected, but the ITO that is the material of the pixel electrode 23 and the constituent material of the lyophilic control layer 25. Since SiO 2, TiO 2, etc. are poor in affinity for fluorine, the hydroxyl group imparted in the ink-philic process is not substituted with the fluorine group, and the lyophilic property is maintained.

  Next, the hole transport layer 70 is formed by a hole transport layer forming step. In this hole transport layer forming step, for example, a hole transport layer material is applied onto the electrode surface 23c by a droplet discharge method such as an ink jet method or a spin coating method, and then a drying process and a heat treatment are performed. A hole transport layer 70 is formed on 23. When the hole transport layer material is selectively applied by, for example, the ink jet method, first, the hole transport layer material is filled in the ink jet head (not shown), and the discharge nozzle of the ink jet head is placed in the lyophilic control layer 25. Opposite the electrode surface 23c located in the formed opening 25a and moving the ink jet head and the base material (substrate 20) relative to each other, the liquid droplets whose liquid amount per droplet is controlled from the discharge nozzle It discharges to the surface 23c. Next, the discharged droplets are dried and the hole transport layer 70 is formed by evaporating the dispersion medium and the solvent contained in the hole transport layer material.

Here, the droplets ejected from the ejection nozzle spread on the electrode surface 23c that has been subjected to the lyophilic treatment, and are filled in the opening 25a of the lyophilic control layer 25. On the other hand, droplets are repelled and do not adhere to the upper surface of the organic barrier layer 221 that has been subjected to ink repellent treatment. Therefore, even if the liquid droplet is deviated from the predetermined discharge position and discharged onto the upper surface of the organic partition layer 221, the upper surface is not wetted by the liquid droplet, and the repelled liquid droplet is opened in the lyophilic control layer 25. Roll into part 25a.
In addition, after this hole transport layer formation process, in order to prevent the oxidation of the hole transport layer 70 and the light emitting layer 60, it is preferable to carry out in inert gas atmospheres, such as nitrogen atmosphere and argon atmosphere.

Next, the light emitting layer 60 is formed by the light emitting layer forming step. In this light emitting layer forming step, the light emitting layer forming material is discharged onto the hole transport layer 70 by, for example, an ink jet method, and then dried and heat-treated to thereby form the inside of the opening 221a formed in the organic partition wall layer 221. The light emitting layer 60 is formed. In this light emitting layer forming step, a nonpolar solvent that is insoluble in the hole transporting layer 70 is used as a solvent used for the light emitting layer forming material in order to prevent re-dissolution of the hole transporting layer 70.
In this light emitting layer forming step, for example, a blue (B) light emitting layer forming material is selectively applied to a blue display region by an inkjet method, dried, and then similarly treated with green (G) and red (R ) Is also selectively applied to the display area and dried.
If necessary, an electron injection layer may be formed on the light emitting layer 60 as described above.

Next, as shown in FIG. 8A, the cathode 50 is formed by a cathode layer forming step. In this cathode layer forming step, for example, an ITO film is formed by physical vapor deposition such as ion plating to form the cathode 50. At this time, the cathode 50 is formed so as to cover not only the upper surfaces of the light emitting layer 60 and the organic barrier layer 221 but also the wall surface forming the outer portion of the organic barrier layer 221.
Next, the cathode protective layer 55 is formed on the cathode 50. As a method of forming the cathode protective layer 55, it is preferable to use a physical vapor deposition method such as an ion plating method.

Next, as shown in FIG. 8B, the organic buffer layer 210a is formed by a liquid phase method, that is, a wet process. For example, in the case of forming by an inkjet method, first, an inkjet buffer (not shown) is filled with an organic buffer layer material diluted with an organic solvent, and the ejection nozzle of the inkjet head is made to face the cathode 50, and the inkjet head and the substrate While relatively moving with respect to (substrate 20), droplets with a controlled liquid amount per droplet are discharged from the discharge nozzle to the cathode 50. Next, the discharged liquid droplets are dried under reduced pressure to evaporate the dispersion medium and the solvent contained in the buffer layer material, thereby forming the organic buffer layer 210a.
In addition, as a method of forming the organic buffer layer 210a, not only an inkjet method but also a slit coating method, a curtain coating method, a screen printing method, a flexographic printing method, or the like that can be applied uniformly over a large area may be employed. it can.
Moreover, since the organic buffer layer 210a has flatness, the viscosity at the time of application is preferably low, for example, 100 mPa · s or less. Further, it is preferable to dilute with an organic solvent or the like in order to lower the viscosity. For example, the cathode and the organic light emitting layer do not like moisture, and thus diluted with a lipophilic organic solvent such as toluene, xylene, cyclohexane, methyl ethyl ketone, and ethyl acetate. Those are preferred.
The thickness of the organic buffer layer is intended to relieve stress caused by flattening and unevenness, and therefore needs to be thicker than the height of the partition wall layer and the pixel partition wall, and is preferably about 5 to 20 μm, for example. Although there is preferably no stress, a slight tensile stress may occur. The film density is preferably a relatively porous film in order to reduce stress as much as possible, and is preferably 0.8 to 1.8 g / cm ³ .
Drying after the application of the organic buffer layer 210a is performed at a curing temperature of 50 to 80 ° C. in a reduced-pressure atmosphere or a dry nitrogen atmosphere in order to completely remove residual moisture in the film. In order to prevent subsequent moisture absorption, it is preferable to move to the next formation process of the inorganic buffer layer 210b without returning to atmospheric pressure.

Further, an inorganic buffer layer 210b is formed.
As a method for forming the inorganic buffer layer 210b, a high-density plasma film forming method is used. As a material of the inorganic buffer layer 210b, a material mainly composed of a transparent inorganic oxide containing oxygen is preferable. Here, the film density is preferably 1.8 to 2.3 g / cm ³ . Although there is preferably no stress, it may be a tensile stress or a compressive stress of 200 MPa or less. The film thickness varies depending on the surface roughness of the organic buffer layer and the diameter of the adhered particles, but is preferably 50 to 400 nm.

Next, as shown in FIG. 8C, the gas barrier layer 30 is formed so as to cover the inorganic buffer layer 210b.
The gas barrier layer is a nitrogen compound having nitrogen formed by a high-density plasma film formation method or the like under reduced pressure, and a transparent thin film mainly made of a silicon compound or silicon oxynitride is preferable. Moreover, it has a denseness to completely block small molecules of water vapor, and preferably has a compressive stress of 200 to 1000 MPa. The film density is preferably 2.3 / cm ³ or more, and the film thickness together with the inorganic buffer layer is preferably 500 nm or less, and preferably 50 to 100 nm.

  As a specific method for forming the inorganic buffer layer 210b and the gas barrier layer 30, a film is first formed by a physical vapor deposition method such as a sputtering method or an ion plating method, and then a chemical vapor deposition method such as a plasma CVD method is performed. The film may be formed by the method. A physical vapor deposition method such as a sputtering method or an ion plating method is generally suitable for the formation of the inorganic buffer layer 210b because a film having relatively good adhesion to a heterogeneous substrate surface can be obtained. The chemical vapor deposition method is suitable for the gas barrier layer 30 because it provides a dense and good film quality with few stresses and few defects with excellent step coverage. These methods can be selected in a timely manner in consideration of mass productivity.

  The gas barrier layer 30 is continuously formed in a vacuum atmosphere without returning to the air atmosphere after the inorganic buffer layer 210b described above is formed. Further, the gas barrier layer 30 and the inorganic buffer layer 210b may be formed by continuously changing the film forming gas type and the mixing ratio in the same process chamber. In this way, the gas barrier layer 30 and the inorganic buffer layer 210b can form a film quality in which the concentration gradient of constituent atoms is continuously different without having an interface. Thereby, it is possible to form a film having both the function of the gas barrier layer 30 and the function of the inorganic buffer layer 210b.

  Further, the gas barrier layer 30 may be formed as a single layer with the same material as described above, or may be formed by laminating a plurality of layers with different materials. Although formed, the composition may be changed continuously or discontinuously in the film thickness direction.

Then, as shown in FIG. 3, a protective layer 204 including an adhesive layer 205 and a surface protective substrate 206 is provided on the gas barrier layer 30. The adhesive layer 205 is applied substantially uniformly on the gas barrier layer 30 by a slit coating method or the like, and the surface protection substrate 206 is bonded thereon.
If the protective layer 204 is provided on the gas barrier layer 30 in this manner, the surface protective substrate 206 has functions such as pressure resistance, wear resistance, antireflection, gas barrier property, and ultraviolet blocking property. The light emitting layer 60, the cathode 50, and also the gas barrier layer can be protected by the surface protective substrate 206, and thus the life of the light emitting element can be extended.
In addition, since the adhesive layer 205 exhibits a buffering function against mechanical impact, when mechanical impact is applied from the outside, the mechanical impact on the gas barrier layer 30 and the light emitting element inside the gas barrier layer 30 is alleviated. It is possible to prevent functional deterioration of the light-emitting element due to mechanical impact.

As described above, the EL display device 1 is formed.
In such an EL display device 1, the organic buffer layer 210 a that covers the cathode 50 and has a substantially flat upper surface is disposed between the cathode 50 and the gas barrier layer 30. Can relieve the warp generated from the substrate 200 side and the stress generated by volume expansion, and prevent the cathode 50 from peeling from the unstable organic partition wall layer 221.
Furthermore, since the upper surface of the organic buffer layer 210a is substantially flattened, the gas barrier layer 30 made of a hard film formed on the organic buffer layer 210a is flattened, and therefore a portion where stress is concentrated on the gas barrier layer 30 is present. As a result, generation of cracks in the gas barrier layer 30 can be prevented.

  In the above-described embodiment, the top emission type EL display device 1 has been described as an example. However, the present invention is not limited to this, and the bottom emission type also emits emitted light on both sides. Applicable to types.

Further, in the case of a bottom emission type or a type that emits emitted light on both sides, the switching TFT 112 and the driving TFT 123 formed on the base 200 are not directly under the light emitting element, but the lyophilic control layer 25 and It is preferable to form it immediately below the organic partition layer 221 to increase the aperture ratio.
In the EL display device 1, the first electrode in the present invention functions as an anode and the second electrode functions as a cathode, but these are reversed to make the first electrode a cathode and the second electrode an anode. It may be configured to function as each. However, in that case, the formation positions of the light emitting layer 60 and the hole transport layer 70 need to be switched.

  In this embodiment, the EL display device 1 is applied to the electro-optical device. However, the present invention is not limited to this, and the second electrode is basically provided outside the substrate. Any type of electro-optical device can be applied.

As described above, according to the present embodiment, the gas barrier layer 30 and the inorganic buffer layer 210b are in contact with each other, and the inorganic buffer layer 210b has a smaller film density than the gas barrier layer 30. The compressive stress when forming is relaxed. Thereby, peeling and cracking of the gas barrier layer 30 can be suppressed. Therefore, the intrusion of moisture can be suppressed and the electro-optic layer can be prevented from deteriorating.
Moreover, since both the gas barrier layer 30 and the inorganic buffer layer 210b are made of an inorganic material, the adhesiveness between them is high, and they do not peel off from each other. Further, by providing such an inorganic buffer layer 210b, the thickness of the gas barrier layer 30 can be made thinner than before. Thereby, the curvature of the board | substrate 20 at the time of forming the gas barrier layer 30 in a thick film can be suppressed. In addition, when the gas barrier layer 30 is simply thinned, the barrier property against moisture generally decreases, but the inorganic buffer layer 210b is formed by the formation of the inorganic buffer layer 210b as described above. Therefore, even when the gas barrier layer 30 is a thin film, moisture can be sufficiently shielded.

Further, since the inorganic buffer layer 210b is formed with a larger area than the organic buffer layer 210a, the organic buffer layer 210a is covered with the inorganic buffer layer 210b. Thereby, the gas barrier layer 30 and the organic buffer layer 210a do not come into direct contact. Thereby, the stress which arises between the gas barrier layer 30 and the organic buffer layer 210a is relieved, and peeling and cracking of the gas barrier layer 30 can be suppressed.
Further, by providing the organic buffer layer 210a, the warp generated from the organic partition layer 221 and the like on the substrate 20 side and the stress generated by the volume change are dispersed, and cracks and peeling generated in the inorganic buffer layer 210b and the gas barrier layer 30 are dispersed. To prevent. Further, by providing the organic buffer layer 210a, it is possible to prevent the cathode 50 from peeling from the unstable partition. Further, since the upper surface of the organic buffer layer 210a is substantially flattened, the inorganic buffer layer 210b and the gas barrier layer 30 formed on the organic buffer layer 210a are flattened, and there is no portion where stress concentration occurs in the gas barrier layer 30, Generation of cracks in the gas barrier layer 30 can be prevented.
Further, since the organic buffer layer 210a fills in fine particles that adhere after the cathode 50 is formed, even if the particles are present, the inorganic buffer layer 210b and the gas barrier layer 30 can be planarized.

  In addition, since the inorganic buffer layer 210b contains oxygen atoms and hydrogen atoms, the density of the inorganic buffer layer 210b is reduced, so that the compressive stress of the gas barrier layer 30 can be effectively relieved. Further, in the inorganic buffer layer 210b, the refractive index of the inorganic buffer layer 210b changes as compared with the case where oxygen atoms are not included. Therefore, the inorganic buffer layer 210b can be adjusted to have a desired refractive index by adjusting the content of oxygen atoms. In addition, when hydrogen atoms are contained in the inorganic buffer layer 210b, the refractive index of the inorganic buffer layer 210b does not change, so that the film quality can be adjusted without changing the refractive index.

In addition, since the cathode protective layer 55 is provided between the cathode 50 and the organic buffer layer 210a, the cathode 50 is protected by the cathode protective layer 55, and an organic solvent or residue when the organic buffer layer 210a is formed. Damage due to moisture can be suppressed.
The inorganic buffer layer 210b covers the organic buffer layer 210a and is formed in contact with the inorganic material on the substrate 20 including the cathode protective layer 55. Therefore, the gas barrier layer 30 is formed of the cathode protective layer 55 and the like. The gas barrier layer 30 is formed above the cathode protective layer 55 and the like via the inorganic buffer layer 210b without being in direct contact with the cathode buffer layer 210b. Therefore, since the compressive stress of the gas barrier layer 30 is relieved by the inorganic buffer layer 210b, peeling and cracking of the gas barrier layer 30 in the inorganic material on the substrate 20 including the cathode protective layer 55 can be suppressed. Accordingly, moisture intrusion due to the peeling or cracking can be suppressed.
Further, since the adhesive layer 205 covering the gas barrier layer 30 and the surface protection substrate 206 are provided, the gas barrier layer 30 is protected, and destruction and damage can be suppressed.

  Further, since the inorganic buffer layer 210b covers the organic buffer layer 210a and is formed in contact with the cathode protective layer 55, the gas barrier layer 30 is not directly in contact with the cathode protective layer 55, and the inorganic buffer layer 210b is formed. Thus, the gas barrier layer 30 is formed on the cathode protective layer 55. Therefore, since the compressive stress of the gas barrier layer 30 is relieved by the inorganic buffer layer 210b, peeling and cracking of the gas barrier layer 30 in the cathode protective layer 55 can be suppressed. Accordingly, moisture intrusion due to the peeling or cracking can be suppressed.

  In addition, since the angle of the side edge of the organic buffer layer 210a is 45 ° or less, the inorganic buffer layer 210b and the gas barrier layer 30 are formed following the shape of the organic buffer layer 210a. Thereby, since the inorganic buffer layer 210b and the gas barrier layer 30 have not a steep shape but a gentle shape, the stress in the inorganic buffer layer 210b and the gas barrier layer 30 can be reduced. Therefore, even if a load is applied to the inorganic buffer layer 210b or the gas barrier layer 30, peeling or cracking does not occur, and entry of moisture can be suppressed.

  Further, the step of forming the inorganic buffer layer 210b and the gas barrier layer 30 is continuously performed in a vacuum atmosphere, so that the inorganic buffer layer 210b and the gas barrier layer 30 are formed without returning to the atmospheric pressure atmosphere. Can be improved. In addition, when returning to the air atmosphere, moisture contained in the air enters between the inorganic buffer layer 210b and the gas barrier layer 30, but moisture is suppressed by forming a film in the same vacuum atmosphere. it can.

Next, the electronic apparatus of the present invention will be described.
The electronic apparatus has the above-described EL display device (electro-optical device) 1 as a display unit, and specifically, the one shown in FIG.
FIG. 9A is a perspective view showing an example of a mobile phone. In FIG. 9A, a mobile phone 1000 includes a display unit 1001 using the EL display device 1 described above.
FIG. 9B is a perspective view illustrating an example of a wristwatch type electronic device. In FIG. 9B, a timepiece 1100 includes a display unit 1101 using the EL display device 1 described above.
FIG. 9C is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. In FIG. 9C, the information processing apparatus 1200 includes an input unit 1201 such as a keyboard, a display unit 1202 using the EL display device 1 described above, and an information processing apparatus body (housing) 1203.
Each of the electronic devices shown in FIGS. 9A to 9C includes the display units 1001, 1101, and 1202 each including the EL display device (electro-optical device) 1 described above. The life of the light emitting element of the display device is extended.

FIG. 11 illustrates a wiring structure of an EL display device. FIG. 9 is a schematic diagram illustrating a configuration of an EL display device. Sectional drawing which follows the AB line | wire of FIG. Sectional drawing which follows the CD line | wire of FIG. The cross-sectional enlarged view which shows the principal part of FIG. The cross-sectional enlarged view which shows the principal part of FIG. The figure which shows the manufacturing method of EL display apparatus in order of a process. The figure which shows the process of following FIG. FIG. 9 illustrates an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display apparatus (electro-optical apparatus), 23 Pixel electrode (1st electrode), 30 Gas barrier layer, 50 Cathode (2nd electrode), 55 Cathode protective layer (electrode protective layer), 60 Light emitting layer (electro-optical layer), 200 Substrate, 210a organic buffer layer, 210b inorganic buffer layer, 221 organic partition layer (partition), 221a opening, 1000 mobile phone (electronic device), 1100 watch (electronic device), 1200 information processing device (electronic device), 1001, 1101, 1202 Display unit (electro-optical device)

Claims (14)

On the substrate, a plurality of first electrodes, a partition wall having a plurality of openings corresponding to positions where the first electrodes are formed, an electro-optic layer disposed in each of the openings, the partition walls, and the electro-optics An electro-optical device having a second electrode covering the layer;
An organic buffer layer covering the second electrode and having a flat upper surface;
An inorganic buffer layer covering the organic buffer layer and formed in a larger area than the organic buffer layer;
An electro-optical device comprising: a gas barrier layer that covers the inorganic buffer layer.   The electro-optical device according to claim 1, wherein the inorganic buffer layer has a film density smaller than that of the gas barrier layer.   The electro-optical device according to claim 1, wherein the inorganic buffer layer and the gas barrier layer are both made of a silicon compound.   The electro-optical device according to claim 1, wherein the inorganic buffer layer contains oxygen atoms.   The electro-optical device according to claim 1, wherein the inorganic buffer layer contains a hydrogen atom.   6. The electro-optical device according to claim 1, wherein the inorganic buffer layer is formed so as to cover the organic buffer layer and to be in contact with an inorganic material on the substrate.   The electro-optical device according to claim 1, further comprising: a resin adhesive layer that covers the gas barrier layer; and a protective base that covers the resin adhesive layer.   The electro-optical device according to claim 1, wherein an electrode protective layer is provided between the second electrode and the organic buffer layer.   9. The electro-optical device according to claim 1, wherein the inorganic buffer layer covers the organic buffer layer and is in contact with the electrode protective layer.   10. The electro-optical device according to claim 1, wherein an angle of a side surface end portion of the organic buffer layer is 45 ° or less. On the substrate, a plurality of first electrodes, a partition wall having a plurality of openings corresponding to positions where the first electrodes are formed, an electro-optic layer disposed in each of the openings, the partition walls, and the electro-optics In a method for manufacturing an electro-optical device having a second electrode that covers a layer,
Covering the second electrode and forming a flat organic buffer layer;
Covering the organic buffer layer and forming an inorganic buffer layer having a larger area than the organic buffer layer;
Forming a gas barrier layer covering the inorganic buffer layer, and a method for manufacturing an electro-optical device.   12. The method of manufacturing an electro-optical device according to claim 11, wherein the step of forming the organic buffer layer uses a liquid phase method under an atmospheric pressure atmosphere.   13. The method of manufacturing an electro-optical device according to claim 11, wherein the step of forming the inorganic buffer layer and the gas barrier layer is continuously performed in a vacuum atmosphere. An electronic apparatus comprising the electro-optical device according to claim 1.

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