JP6471308B2 - Display device and manufacturing method of display device - Google Patents

Description

  The present disclosure relates to a display device having an organic electroluminescence (Organic Electro-Luminescence; hereinafter, sometimes referred to as EL or OLED) element.

  The organic EL device has an anode side conductive layer, an organic layer including a light emitting layer, and a cathode side conductive layer on a glass substrate. One of the anode side conductive layer and the cathode side conductive layer is integrally formed so as to be arranged in common over a plurality of pixels (for example, see Patent Document 1). At this time, the case where the anode side conductive layer is common is called anode common, and the case where the conductive layer arranged on the cathode side is common is called cathode common.

  In a pixel circuit of a display device, a combination of a driving TFT (Thin Film Transistor) and an organic EL element includes, for example, a combination of an n-type driving TFT and a common cathode organic EL element. In the pixel circuit having the top emission structure, the top metal of the organic EL element is integrally formed so as to be commonly disposed in each pixel with a transparent material from the viewpoint of high efficiency of light extraction. Therefore, in the case of a combination of an n-type driving TFT and a common cathode organic EL element, a configuration of a top cathode in which a cathode-side conductive layer is integrally formed on the source side with a transparent material is generally used.

JP 2007-179913 A

  However, in the pixel circuit having the above-described combination, the voltage becomes unstable as the display device has higher luminance and a larger screen.

  Therefore, when a combination of an n-type driving TFT and an anode common organic EL element is adopted, the anode side conductive layer of the organic EL element is integrally formed on the drain side so as to be commonly disposed in each pixel. The cathode-side conductive layer is preferably formed on the source side and above. Therefore, the cathode-side conductive layer formed above needs to be cut for each pixel.

  However, when the cathode side conductive layer, the light emitting layer, and the charge transport layer are separated for each pixel in this structure, the light emitting layer and the charge transport layer are formed at the connection portion (contact portion) between the cathode side conductive layer and the pixel circuit. . In general, an organic EL element has a current rectification characteristic and flows only in one direction (forward direction) from the anode to the cathode. Therefore, when the light emitting layer and the charge transport layer are formed in the contact portion, the direction of flow from the organic EL element to the pixel circuit is reversed, and it is difficult to ensure conduction between the pixel circuit and the organic EL element. That is, it becomes difficult to emit light.

  The present disclosure has been made in view of the above-described problems, and an object thereof is to provide a display device with good display characteristics and a method for manufacturing the display device.

  A display device according to the present disclosure is a display device in which a plurality of pixels are arranged in a matrix, and includes a wiring provided on a substrate, the substrate and an interlayer insulating layer provided above the wiring, An anode provided above the interlayer insulating layer and a contact hole provided above the interlayer insulating layer and formed in the interlayer insulating layer and connected to a part of the wiring exposed on the bottom surface of the contact hole A contact electrode, an opening provided between the anode and the contact electrode, a first partition provided to cover the opening, and the first partition above the anode A light-emitting layer including an organic light-emitting material, a second barrier rib having a reverse taper shape provided on the first barrier rib, and provided at least above the light-emitting layer. Electronic An organic functional layer having a light entering property or an electron transporting property, and a cathode provided on the organic functional layer, wherein the anode is provided in common for the plurality of pixels, and the cathode and the organic functional layer Are divided for each of the plurality of pixels.

  According to the present disclosure, it is possible to provide a display device with good display characteristics and a method for manufacturing the display device.

Schematic which shows the structure of the display apparatus concerning this Embodiment. The circuit diagram showing an example of the composition of the pixel concerning this embodiment The circuit diagram which shows the other example of the structure of the pixel concerning this Embodiment The top view which shows the structure of the pixel concerning this Embodiment. Sectional view along the line AA 'shown in FIG. Sectional view taken along line BB 'shown in FIG. FIG. 5 is a plan view showing a manufacturing process of a pixel according to the embodiment. FIG. 5 is a plan view showing a manufacturing process of a pixel according to the embodiment. FIG. 5 is a plan view showing a manufacturing process of a pixel according to the embodiment. External view of thin flat TV with built-in display device according to embodiment

  In order to solve the above-described problem, a display device according to one embodiment of the present disclosure is a display device in which a plurality of pixels are arranged in a matrix, and includes a wiring provided over a substrate, the substrate, In the interlayer insulating layer provided above the wiring, the anode provided above the interlayer insulating layer, and the contact hole provided in the interlayer insulating layer provided above the interlayer insulating layer, the contact A contact electrode connected to a part of the wiring exposed at the bottom surface of the hole; an opening provided between the anode and the contact electrode; and a first electrode provided to cover the opening A barrier rib; a light emitting layer including an organic light emitting material provided in a region surrounded by the first barrier rib above the anode; and a first taper having a reverse taper shape provided on the first barrier rib. 2 bulkheads and few And an organic functional layer having an electron injecting property or an electron transporting property provided above the light emitting layer, and a cathode provided on the organic functional layer, wherein the anode is common to the plurality of pixels. The cathode and the organic functional layer are divided for each of the plurality of pixels.

  According to this configuration, the second partition wall has an inverse tapered shape, that is, the area of the bottom surface in contact with the first partition wall is smaller than the area of the top surface not in contact with the first partition wall, and the cross-sectional shape is a trapezoidal shape. Thus, the organic functional layer and the cathode are not formed on the side surface of the second partition wall, and the organic functional layer and the cathode are divided for each pixel. Therefore, even if the wiring and the anode, the organic functional layer, and the cathode are electrically connected in the contact hole, a desired voltage is applied to each light emitting layer disposed between the anode and the cathode. Therefore, a display device with favorable display characteristics can be provided.

  The cathode and the organic functional layer are provided above the second partition, and the cathode and the organic functional layer provided above the second partition are the light emitting layer and the first It may be divided from the cathode and the organic functional layer provided above the partition walls.

  According to this configuration, the organic functional layer and the cathode are not formed on the side surface of the second partition, and the organic functional layer and the cathode are divided on both sides of the second partition. Therefore, even if the wiring and the anode, the organic functional layer, and the cathode are electrically connected in the contact hole, a desired voltage is applied to each light emitting layer disposed between the anode and the cathode. Therefore, a display device with favorable display characteristics can be provided.

  The organic functional layer may include a metal having an electron injecting property or an electron transporting property.

  According to this structure, the electron transport property of an organic functional layer can be improved by including the metal which has electron transport property.

  The metal may be barium.

  According to this configuration, by including barium as a metal having an electron transporting property, the types of materials to be prepared can be reduced, and it is easy to manufacture, and the electron transporting property of the organic functional layer is improved by one kind of metal. can do.

  The anode may be made of ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).

  According to this configuration, the light generated in the light emitting layer can be efficiently reflected to the cathode side.

  The cathode may be made of a transparent conductive material.

  According to this configuration, light generated in the light emitting layer can be extracted from the cathode side.

  The transparent conductive material may be ITO.

  According to this configuration, light generated in the light emitting layer can be efficiently extracted from the cathode side.

  In addition, a hole injection layer provided in common between the anode and the light emitting layer may be provided, and the hole injection layer may be composed of either tungsten oxide or molybdenum oxide.

  According to this configuration, injection of holes from the anode to the light emitting layer can be promoted.

  The organic functional layer may have a thickness of 25 nm or more and 45 nm or less.

  According to this configuration, 80% light extraction efficiency can be ensured with respect to the peak light extraction efficiency.

  The thickness of the organic functional layer may be 30 nm or more and 40 nm or less.

  According to this configuration, it is possible to ensure a light extraction efficiency of 90% with respect to the peak light extraction efficiency.

  In order to solve the above-described problem, a method for manufacturing a display device according to one embodiment of the present disclosure is a method for manufacturing a display device in which a plurality of pixels are arranged in a matrix, and is provided over a substrate. Forming a contact hole in an interlayer insulating layer on the wiring, forming an anode on the interlayer insulating layer, and exposing the wiring exposed on the bottom surface of the contact hole so that the exposed wiring is exposed. Forming a contact electrode connected to a portion; forming a first partition so as to cover an opening provided between the anode and the contact electrode; and the first above the anode. Forming a light emitting layer containing an organic light emitting material in a region surrounded by one partition, forming a second partition having a reverse taper shape on the first partition, and the light emitting layer The first partition and the first partition A step of forming an organic functional layer having an electron injecting property or an electron transporting property above the partition wall, and a step of forming a cathode on the organic functional layer, wherein the anode is common to a plurality of pixels. The cathode and the organic functional layer provided above the second partition are separated from the cathode and the organic functional layer provided above the light emitting layer and the first partition. Yes.

  According to this configuration, the second partition wall has an inverse tapered shape, that is, the area of the bottom surface in contact with the first partition wall is smaller than the area of the top surface not in contact with the first partition wall, and the cross-sectional shape is a trapezoidal shape. Thus, the organic functional layer and the cathode are not formed on the side surface of the second partition, and the organic functional layer and the cathode are divided on both sides of the second partition. Therefore, even if the wiring and the anode, the organic functional layer, and the cathode are electrically connected in the contact hole, a desired voltage is applied to the light emitting layer disposed between the anode and the cathode. Therefore, a display device with favorable display characteristics can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, steps, order of steps, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims are described as arbitrary constituent elements. Each drawing does not necessarily show exactly each dimension or each dimension ratio.

(Embodiment)
[1. Configuration of display device]
FIG. 1 is a schematic diagram illustrating a configuration of a display device 1 according to the present embodiment.

  As shown in FIG. 1, the display device 1 includes a display area 2, a scanning line driving circuit 6, and a signal line driving circuit 7. The display area 2 has a plurality of pixels 4 arranged in a matrix.

  The pixel 4 is electrically connected to the scanning line driving circuit 6 through the scanning line 9a, and is electrically connected to the signal line driving circuit 7 through the signal line 9b. The configuration of the pixel 4 will be described in detail later.

  The signal line drive circuit 7 outputs an image signal Data corresponding to the display image to the pixels 4 via the signal line 9b. The scanning line driving circuit 6 outputs a scanning signal Scan via the pixels 4 and the scanning lines 9a. The pixel signal Data is transferred to the pixel 4 by the scanning signal Scan. Thereby, the pixel 4 can display an image according to the image signal Data.

[2. Pixel configuration]
Next, the configuration of the pixel 4 according to this embodiment will be described. 2A and 2B are circuit diagrams showing the configuration of the pixel 4 according to the present embodiment. FIG. 3 is a plan view showing the configuration of the pixel according to the present embodiment.

  As shown in FIG. 2A, the pixel 4 includes a light emitting element 10, a capacitive element 12, a drive transistor 16a, and a switch transistor 16b. Between the light emitting element 10 and the driving transistor 16a, a connection resistance 16c between a contact electrode and a TFT wiring is generated in a contact hole 25 described later. In the pixel 4, when the scanning signal Scan is supplied from the scanning line 9a, the pixel signal Data that is a voltage corresponding to the pixel signal is applied from the signal line 9b to the gate of the driving transistor 16a. As a result, a current corresponding to the pixel signal flows through the light emitting element 10, and the light emitting element 10 emits light with a luminance corresponding to the pixel signal.

  More specifically, the pixel 4 is provided with a reference power supply line VREF, an EL anode power supply line VTEL, and an EL cathode power supply line VTFT. An anode voltage generation circuit (not shown) that generates an anode voltage to be applied to the light emitting element 10 is connected to the EL anode power supply line VEL. A cathode voltage generation circuit (not shown) that generates a cathode voltage to be applied to the light emitting element 10 is connected to the EL cathode power supply line VTFT. The EL cathode power supply line VTFT may be grounded instead of being connected to the cathode voltage generation circuit.

  The configuration of the pixel is not limited to the configuration of the pixel 4 described above, and may be a configuration like the pixel 4a illustrated in FIG. 2B.

  As shown in FIG. 2B, the pixel 4a includes a light emitting element 10, a capacitive element 12, a drive transistor 17a, a switch transistor 17b, and transistors 17c and 17d. In the pixel 4a, when the scanning signal Select is supplied from the scanning line 9a, charges corresponding to the pixel signal from the signal line 9b are accumulated in the capacitor element 12. By applying a voltage corresponding to the charge accumulated in the capacitor element 12 to the gate of the driving transistor 17a, a current corresponding to the pixel signal flows to the light emitting element 10, and the light emitting element 10 has a luminance corresponding to the pixel signal. Emits light.

  Further, the configuration of the pixel is not limited to the configuration illustrated in FIGS. 2A and 2B, and may be other configurations.

  Hereinafter, the configuration of the pixel will be described with reference to FIGS. 3 to 5 by taking the pixel 4 shown in FIG. 2A as an example. As shown in FIG. 3, the pixel 4 is a pixel corresponding to each of R (red), G (green), and B (blue) as sub-pixels, and one display is provided by the three pixels 4 of R, G, and B. Pixels are configured.

  4 is a cross-sectional view taken along the line AA 'shown in FIG. FIG. 5 is a cross-sectional view taken along line BB ′ shown in FIG.

  The display device 1 is a display device having a so-called top emission type structure in which the upper side in FIGS. 4 and 5 is the display surface. The display device 1 includes a substrate 20, a TFT circuit 21, a wiring 22, an interlayer insulating layer 23, an anode 26 a, a contact electrode 26 b, a hole injection layer, a hole transport layer and a light emitting layer 29, a first Partition wall 28, second partition wall 30, organic functional layer 32, and cathode 34. The substrate 20, the interlayer insulating layer 23, and the TFT circuit 21 are formed in common for a plurality of pixels included in the display device 1. 2A includes an anode 26a, a hole injection layer, a hole transport layer and a light emitting layer 29, an organic functional layer 32, and a cathode 34.

  Hereinafter, each part structure of the display apparatus 1 is demonstrated.

<Board>
The substrate 20 is made of, for example, an insulating material such as polyimide resin, acrylic resin, styrene resin, polycarbonate resin, epoxy resin, polyether sulfone, polyethylene, polyester, silicon resin, and glass substrate. . A TFT circuit 21 is formed on the substrate 20. In the TFT circuit 21, a drive circuit (not shown) composed of TFTs is formed for each pixel 4.

<Interlayer insulation layer>
The interlayer insulating layer 23 is formed on the substrate 20 and the TFT circuit 21. The interlayer insulating layer 23 is for flattening a step between the upper surface of the substrate 20 and the upper surface of the TFT circuit 21. The interlayer insulating layer 23 is made of, for example, a positive photosensitive material. As the positive photosensitive material, acrylic resin, polyimide resin, siloxane resin, phenol resin, or the like is used.

<Anode and contact electrode>
The anode 26 a and the contact electrode 26 b are formed on the interlayer insulating layer 23. The anode 26 a is formed on the light emitting region in the pixel 4. The contact electrode 26b is formed on a contact hole 25 described later. The anode 26a and the contact electrode 26b may be formed at the same time or separately.

  The anode 26a and the contact electrode 26b have a laminated structure of a light reflective conductive material and a transparent conductive material, for example. As a light-reflective conductive material, silver (Ag), aluminum (Al), aluminum alloy, molybdenum (Mo), APC (alloy of silver, palladium, and copper), ARA (alloy of silver, rubidium, and gold), MoCr (Alloy of molybdenum and chromium), MoW (alloy of molybdenum and tungsten), NiCr (alloy of nickel and chromium), or the like may be used. As the transparent conductive material, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), ZnO (zinc oxide), or the like may be used. The anode 26a and the contact electrode 26b may have a single layer structure of a light-reflective conductive material.

  Here, a contact hole 25 is formed for each pixel 4 in the interlayer insulating layer 23. The contact hole 25 is formed so that the wiring 22 is exposed on the bottom surface. The contact electrode 26 b is formed in the contact hole 25 and is electrically connected to the drive circuit formed in the TFT circuit 21 through the wiring 22 exposed on the bottom surface of the contact hole 25 of the interlayer insulating layer 23.

  Further, as shown in FIG. 3, an opening 27 is formed between the anode 26a and the contact electrode 26b so as to surround the periphery of the contact hole 25 when viewed in plan. As a result, the anode 26a arranged in the light emitting region of the pixel 4 and the contact electrode 26b arranged on the contact hole 25 side are divided as shown in FIG. As shown in FIG. 3, the anode 26 a is formed in a rectangular shape when the pixel 4 is viewed in plan. The anode 26a is arranged in common for the three pixels 4 of R, G, and B.

  In the present embodiment, the contact electrode 26b is formed in the contact hole 25, and a connection region in which the organic functional layer 32 and the cathode 34 are connected is formed above, but the contact electrode 26b is not necessarily in the contact hole. 25 may be provided separately. In addition, with the arrangement as shown in FIG. 4, a wider light emitting area can be secured.

<Wiring>
The wiring 22 is provided under the interlayer insulating layer 23. The wiring 22 is configured by a wiring that forms the TFT circuit 21. For example, titanium, molybdenum, tungsten, aluminum, aluminum alloy, copper, copper alloy, ITO, or IZO can be used.

  By arranging the wiring 22 in this way, connection between the wiring 22 and the portion of the cathode 34 facing the wiring 22 can be realized.

<First partition wall>
As shown in FIG. 3, the first partition wall 28 is formed in a frame shape having two rectangular openings. The first partition wall 28 is formed so as to cover the anode 26a, the contact electrode 26b, and the opening 27 opened between the anode 26a and the contact electrode 26b.

  The first partition 28 has a function of preventing the applied ink from overflowing when a light emitting layer 29 described later is formed by a wet process. On the other hand, the first partition 28 has a function as a structure for placing a vapor deposition mask when the light emitting layer 29 is formed by vapor deposition. The first partition 28 is made of, for example, a positive photosensitive material. Specifically, as the material of the first partition wall 28, a phenol resin, an acrylic resin, a polyimide resin, a siloxane resin, or the like may be used.

<Hole injection layer>
The hole injection layer (not shown) has a function of accelerating the injection of holes from the anode 26a to the light emitting layer 29, and is provided between the anode 26a and the light emitting layer 29 at least in the light emitting region. The hole injection layer may be, for example, a metal oxide such as tungsten oxide (WOx), molybdenum oxide (MoOx), silver (Ag), chromium (Cr), vanadium (V), nickel (Ni), or iridium (Ir). Is formed by a sputtering method. The hole injection layer may be formed by applying and drying ink with PEDOT (a mixture of polythiophene and polystyrene sulfonic acid), polyaniline, or the like. Since a partition wall is required for the ink application process, the formation of the hole injection layer by the ink application is performed after the formation of the first partition wall 28 and before the formation of the hole transport layer. The hole injection layer may be a combination of a layer formed by sputtering or the like and a layer formed by coating.

<Hole transport layer>
The hole transport layer (not shown) has a function of transporting holes injected from the hole injection layer to the light emitting layer 29. The hole transport layer is formed by applying and drying an organic material solution composed of a polymer compound such as polyfluorene or a derivative thereof, or polyarylamine or a derivative thereof. In addition, the hole transport layer includes triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, It may be formed of a fluorenone derivative, a hydrazone derivative, a stilbene derivative, a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, a butadiene compound, a polystyrene derivative, a hydrazone derivative, a triphenylmethane derivative, or a tetraphenylbenzine derivative. The hole transport layer is preferably formed by a vacuum deposition method using a porphyrin compound, an aromatic tertiary amine compound, a styrylamine compound, or the like.

<Light emitting layer>
The light emitting layer 29 has a function of emitting light of R, G, and B colors by recombination of holes and electrons. The light emitting layer 29 is formed in a region above the anode 26 a and surrounded by the first partition wall 28. The light emitting layer 29 includes an organic light emitting material. Organic light-emitting materials include, for example, oxinoid compounds, perylene compounds, coumarin compounds, azacoumarin compounds, oxazole compounds, oxadiazole compounds, perinone compounds, pyrrolopyrrole compounds, naphthalene compounds, anthracene compounds, fluorene compounds, fluoranthene compounds, tetracene compounds, pyrenes Compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenanthrene compound, cyclopentadiene compound, stilbene compound, diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylene Thiopyran compound, fluorescein compound, pyrylium compound, thiapyrylium Products, serenapyrylium compounds, telluropyrylium compounds, aromatic aldadiene compounds, oligophenylene compounds, thioxanthene compounds, cyanine compounds, acridine compounds, metal chains of 8-hydroxyquinoline compounds, metal chains of 2-bipyridine compounds, Schiff salts And a fluorescent material such as a chain of a group III metal, an oxine metal chain, and a rare earth chain. In addition, a known phosphor such as a metal complex emitting phosphorescence such as tris (2-phenylpyridine) iridium can be used. The light emitting layer 29 may be made of polyfluorene or a derivative thereof, polyphenylene or a derivative thereof, a polymer compound such as polyarylamine or a derivative thereof, or the like, or a mixture of the low molecular compound and the polymer compound. In this case, the light emitting layer 29 is formed by applying and drying an organic material solution.

  On the other hand, the first partition 28 has a function as a structure for placing a vapor deposition mask when the light emitting layer 29 is formed by vapor deposition. The first partition 28 is made of, for example, a positive photosensitive material. Specifically, as the material of the first partition wall 28, a phenol resin, an acrylic resin, a polyimide resin, a siloxane resin, or the like may be used.

<Second partition wall>
As shown in FIGS. 4 and 5, the second partition wall 30 is formed on and in contact with the first partition wall 28. The second partition wall 30 is formed such that the area of the bottom surface in contact with the first partition wall 28 is smaller than the area of the top surface not in contact with the first partition wall 28 and the cross-sectional shape is a trapezoidal shape, that is, an inversely tapered shape. Has been.

  The second partition wall 30 is formed on both sides of the second partition wall 30 so that the organic function layer 32 and the cathode 34 in the adjacent pixels 4 are not electrically connected when the organic function layer 32 and the cathode 34 described later are formed. It is formed in order to obtain a divided structure. Due to the configuration of the second partition 30 described above, the organic functional layer 32 and the cathode 34 are formed on the light emitting layer 29, the first partition 28 and the second partition 30 by, for example, sputtering. At this time, since the second partition wall 30 has the reverse tapered shape as described above, the organic functional layer 32 and the cathode 34 are not formed on the side surface of the second partition wall 30, and the organic functional layer 32 and A configuration in which the cathode 34 is divided on both sides of the second partition wall 30 can be realized.

  The second partition wall 30 is made of, for example, a negative photosensitive material. Specifically, as the material of the second partition wall 30, a phenol resin, an acrylic resin, a polyimide resin, a siloxane resin, or the like may be used.

<Organic functional layer>
The organic functional layer 32 is provided above the light emitting layer 29, the first partition 28, the second partition 30, and the wiring 22. The organic functional layer 32 is made of, for example, an organic material containing a metal having an electron transport property, and has a function as an electron transport layer that transports electrons injected from the cathode 34 to the light emitting layer 29. By including a metal having an electron transporting property, the electron transporting property of the organic functional layer 32 can be improved. As an organic material of the organic functional layer 32, for example, an oxadiazole derivative (OXD), a triazole derivative (TAZ), a phenanthroline derivative (BCP, Bphen), or the like can be used. As the metal contained in the organic functional layer 32, for example, barium (Ba), lithium (Li), calcium (Ca), potassium (K), cesium (Cs), sodium (Na), rubidium (Rb), or the like is used. Can do. In addition, the organic functional layer 32 may be comprised only with the organic material which has electron transport property.

  Note that the thickness of the organic functional layer 32 may be, for example, 25 nm or more and 45 nm or less. According to this configuration, 80% light extraction efficiency can be ensured with respect to the peak light extraction efficiency. Moreover, it is preferable that the thickness of the organic functional layer 32 is 30 nm or more and 40 nm or less. According to this configuration, it is possible to ensure a light extraction efficiency of 90% with respect to the peak light extraction efficiency.

  Further, the organic functional layer 32 does not have to be provided above all of the light emitting layer 29, the first partition 28, the second partition 30, and the wiring 22, and is provided at least above the light emitting layer 29. That's fine.

<Cathode>
The cathode 34 is provided above the light emitting layer 29, the first partition 28, and the wiring 22 via the organic functional layer 32. The cathode 34 is made of, for example, a transparent conductive material. By forming the cathode 34 with the transparent conductive material, light generated in the light emitting layer 29 can be extracted from the cathode 34 side. As the transparent conductive material of the cathode 34, for example, ITO, IZO or the like can be used. In addition to this, for example, the cathode 34 may use MgAg (magnesium silver). In this case, light can be transmitted by setting the thickness of the cathode 34 to about several tens of nm.

  Note that the cathode 34 does not have to be provided above all of the light emitting layer 29, the first partition 28, the second partition 30, and the wiring 22, and may be provided at least above the light emitting layer 29. .

<Others>
Although not shown in FIGS. 3 to 5, a sealing layer may be provided on the cathode 34 in the pixel 4. The sealing layer has a function of suppressing water and oxygen from entering the organic functional layer 32 and the cathode 34 from the side opposite to the side where the substrate 20 is disposed with respect to the light emitting layer 29. The sealing layer is made of, for example, a light transmissive material. As the light transmissive material, silicon nitride (SiN), silicon oxynitride (SiON), or the like may be used.

[3. Display device manufacturing method]
Next, an example of a method for manufacturing the display device 1 will be described with reference to the plan views of FIGS. FIG. 6 is a plan view showing a manufacturing process of the pixel according to the present embodiment. FIG. 7 is a plan view showing the manufacturing process of the pixel according to the present embodiment. FIG. 8 is a plan view showing the manufacturing process of the pixel according to the present embodiment.

  First, the substrate 20 on which the TFT circuit 21 is formed is prepared. A wiring 22 connected to the TFT circuit 21 is formed on the substrate 20.

  Next, an interlayer insulating layer 23 is laminated on the substrate 20, the TFT circuit 21, and the wiring 22. Further, a contact hole 25 is formed at a predetermined position of the interlayer insulating layer 23. For example, when the interlayer insulating layer 23 is formed of a photosensitive material, the contact hole 25 is formed by development. As a result, the wiring 22 is exposed on the bottom surface of the contact hole 25.

  Next, an anode 26 a is formed on the interlayer insulating layer 23, and a contact electrode 26 b is formed in the contact hole 25. The anode 26a and the contact electrode b are formed in common on the pixels 4 adjacent to the entire surface of the substrate 20, as shown in FIG.

  Next, as shown in FIG. 6, an opening 27 having an opening around the contact hole 25 when provided in a plan view is provided. The anode 27 a and the contact electrode 26 b are separated by the opening 27. The opening 27 is formed by wet etching, for example. On the bottom surface of the opening 27, the interlayer insulating layer 23 is exposed.

  Further, as shown in FIGS. 4 and 7, a first partition 28 is formed on anode 26 a, contact electrode 26 b, and interlayer insulating layer 23 so as to cover opening 27. The first partition 28 is formed, for example, by applying a positive photosensitive material. As shown in FIG. 7, the first partition 28 is formed in a frame shape in which the light emitting region and the contact region are opened.

  Next, a hole injection layer (not shown) is formed on the anode 26 a surrounded by the frame-shaped first partition wall 28. The hole injection layer may not be formed on the wiring 22. When the hole injection layer is formed by a coating process, the hole injection layer is formed after the first partition wall 28 is formed and before the hole transport layer is formed. When the hole injection layer is formed by a sputtering method, it may be formed after the above-described anode 26a is formed and processed in the same pattern as the anode 26a.

  Next, a hole transport layer (not shown) and a light emitting layer 29 are formed on the hole injection layer. The hole transport layer and the light emitting layer 29 are each formed by applying an ink containing an organic material and baking (drying) the ink. The hole transport layer and the light emitting layer 29 are not limited to a wet process, and may be formed by, for example, a vacuum deposition method. Further, the hole transport layer may not be formed on the wiring 22.

  Next, as shown in FIG. 8, the second partition 30 is formed on the first partition 28. The second partition wall 30 is formed, for example, by applying a negative photosensitive material. A negative photosensitive material is wet-etched to form an inversely tapered shape as shown in FIGS.

  Further, an organic functional layer 32 containing barium is formed on the contact electrode 26 b, the light emitting layer 29, and the second partition wall 30. Specifically, the organic functional layer 32 doped with barium is formed by depositing the material and barium that constitute the organic functional layer using a vacuum evaporation method. Since the organic functional layer 32 includes one type of metal made of barium, the types of materials to be prepared can be reduced, and the manufacturing is simple. The organic functional layer 32 formed on the second partition 30 is not continuous with the organic functional layer 32 formed on the light emitting layer 29 and the contact electrode 26b, and has a separate configuration.

  A cathode 34 is formed on the organic functional layer 32. Specifically, first, ITO constituting the cathode 34 is formed into a film by a vacuum deposition method, a sputtering method, or the like to form the cathode 34. The cathode 34 formed on the second partition wall 30 via the organic functional layer 32 is not continuous with the cathode 34 formed on the light emitting layer 29 and the contact electrode 26b, and has a separate configuration.

  That is, the cathode 34 and the organic functional layer 32 provided above the second partition 30 are separated from the cathode 34 and the organic functional layer 32 provided above the light emitting layer 29 and the first partition 28. As a result, the cathode 34 and the organic functional layer 32 have a configuration that is not common to the plurality of pixels 4 and are not electrically conductive, so that different voltages can be applied to the light emitting layer 29 for each pixel 4 to emit light. it can.

  Finally, a sealing layer is formed on the cathode 34. SiN constituting the sealing layer is formed on the cathode 34 by using a sputtering method, a CVD (Chemical Vapor Deposition) method, and the light emitting region and the contact region are sealed.

  The display device 1 is completed through the above steps. In a top emission type organic light emitting device such as the display device 1, the thickness of the cathode 34 may be reduced in order to increase the light extraction efficiency. In the organic light-emitting device in which the thickness of the cathode 34 is reduced, voltage variations easily occur within the panel surface of the cathode 34, so that the electrical resistance value between the wiring 22 and the portion of the cathode 34 facing the wiring 22 is particularly large. It is useful to suppress.

[4. effect]
As described above, according to the display device 1 according to the present embodiment, the second partition 30 has a cross-sectional shape in which the area of the bottom surface in contact with the first partition 28 is smaller than the area of the top surface not in contact with the first partition 28. Since it is formed to have a trapezoidal shape, that is, an inversely tapered shape, the organic functional layer 32 and the cathode 34 are not formed on the side surface of the second partition wall 30, and the organic functional layer 32 and the cathode 34 are provided for each pixel 4. It becomes a divided structure. More specifically, the organic functional layer 32 and the cathode 34 are not formed on the side surface of the second partition wall 30, and the organic functional layer 32 and the cathode 34 are disposed on both sides of the second partition wall 30. Is a divided configuration.

  Therefore, even if the wiring 22 and the contact electrode 26b, the organic functional layer 32, and the cathode 34 are electrically connected in the contact hole 25, the light emitting layer 29 disposed between the anode 26a and the cathode 34 in the pixel region has a desired shape. Since the voltage is applied, the display device 1 with good display characteristics can be provided. Therefore, even if the cathode is not formed using a high-definition mask, a non-conductive cathode and an organic functional layer are easily formed for each pixel by providing the second partition on the first partition. can do.

(Other embodiments)
Although the display device according to the embodiment has been described above, the display device is not limited to the above-described embodiment. The present invention includes modifications obtained by making various modifications conceived by those skilled in the art within the scope of the present invention without departing from the gist of the present invention, and various devices incorporating a display device.

  For example, the angle of the inversely tapered shape in the second partition wall, that is, the angle between the upper surface of the first partition wall and the side surface of the second partition wall only needs to be smaller than 90 degrees. The smaller the angle between the side walls of the two partition walls, the better.

  Further, the height of the second partition is larger than the thickness of the cathode and the organic functional layer, and the cathode and the organic functional layer formed on the second partition are formed on the light emitting layer and the anode. In addition, the height is preferably high enough to be separated from the organic functional layer.

  Further, the first partition wall needs to have water repellency in order to prevent the light emitting layer from flowing out during manufacture, but the second partition wall may not have water repellency. It is better to have water repellency.

  The anode may have, for example, a laminated structure of a light reflective conductive material and a transparent conductive material, or a single layer structure of a light reflective conductive material.

  In addition, the organic functional layer does not have to be provided above all of the light emitting layer, the first partition, the second partition, and the wiring, and may be provided at least above the light emitting layer. Similarly, the cathode does not have to be provided above all of the light emitting layer, the first partition, the second partition, and the wiring, and may be provided at least above the light emitting layer.

  Also, within the scope of the present invention, various modifications conceived by those skilled in the art and forms constructed by combining components in different embodiments are also within the scope of the present invention without departing from the spirit of the present invention. included. For example, a thin flat TV system including the display device according to the present invention as shown in FIG. 9 is also included in the present invention.

  The present invention is particularly useful in technical fields such as flat-screen televisions and personal computer displays that require a large screen and high resolution.

DESCRIPTION OF SYMBOLS 1 Display apparatus 2 Display area 4, 4a Pixel 6 Scan line drive circuit 7 Signal line drive circuit 9a Scan line 9b Signal line 10 Light emitting element 12 Capacitance element 16a, 17a Drive transistor 16b, 16c, 17b Switch transistor 20 Substrate 21 TFT circuit 22 Wiring 23 Interlayer insulating layer 25 Contact hole 26a Anode 26b Contact electrode 27 Opening 28 First partition 29 Light emitting layer 30 Second partition 32 Organic functional layer 34 Cathode

Claims (10)

A display device in which a plurality of pixels are arranged in a matrix,
Wiring provided on the substrate;
An interlayer insulating layer provided above the substrate and the wiring;
An anode provided above the interlayer insulating layer;
A contact electrode provided above the interlayer insulating layer and connected to a part of the wiring exposed at the bottom surface of the contact hole in a contact hole formed in the interlayer insulating layer;
An opening provided between the anode and the contact electrode;
A first partition provided so as to cover the opening;
A light emitting layer including an organic light emitting material provided in a region surrounded by the first partition above the anode;
A second partition provided on the first partition and having a reverse taper shape;
An organic functional layer having an electron injecting property or an electron transporting property provided at least above the light emitting layer;
A cathode provided on the organic functional layer,
The anode is provided in common for the plurality of pixels,
The cathode and the organic functional layer is divided for each of the plurality of pixels,
Above the second partition, the cathode and the organic functional layer are provided,
The cathode and the organic functional layer provided above the second partition are separated from the cathode and the organic functional layer provided above the light emitting layer and the first partition,
Display device. The organic functional layer contains a metal having an electron injecting property or an electron transporting property,
The display device according to claim 1 . The metal is barium;
The display device according to claim 2 . The anode is composed of ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).
Display device according to any one of claims 1-3. The cathode is made of a transparent conductive material,
The display apparatus of any one of Claims 1-4 . The transparent conductive material is ITO,
The display device according to claim 5 . A hole injection layer provided in common between the anode and the light emitting layer;
The hole injection layer is composed of either tungsten oxide or molybdenum oxide.
Display device according to any one of claims 1-6. The thickness of the organic functional layer is 25 nm or more and 45 nm or less.
The display device according to any one of claims 1-7. The thickness of the organic functional layer is 30 nm or more and 40 nm or less,
Display device according to any one of claims 1-7. A method of manufacturing a display device in which a plurality of pixels are arranged in a matrix,
Forming a contact hole in an interlayer insulating layer on the wiring so that the wiring provided on the substrate is exposed;
Forming an anode on the interlayer insulating layer;
Forming a contact electrode connected to a part of the wiring exposed at the bottom of the contact hole;
Forming a first partition so as to cover an opening provided between the anode and the contact electrode;
Forming a light emitting layer containing an organic light emitting material in a region surrounded by the first partition above the anode;
Forming a second partition having an inversely tapered shape on the first partition;
Forming an organic functional layer having an electron injecting property or an electron transporting property above the light emitting layer, the first partition, and the second partition;
Forming a cathode on the organic functional layer,
The anode is provided in common for a plurality of pixels,
The cathode and the organic functional layer provided above the second partition are separated from the cathode and the organic functional layer provided above the light emitting layer and the first partition,
Manufacturing method of display device.

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