JP4572561B2 - Self-luminous display device - Google Patents

Description

  The present invention relates to a self-luminous display device such as an organic EL display.

  Conventionally, an organic electroluminescence (hereinafter, referred to as organic EL) display uses a transparent substrate, and an organic layer having a light emitting function disposed between a pair of electrodes emits current by passing a current between the electrodes. Realized. At this time, by making the electrode on the transparent substrate side transparent to visible light, light emission is emitted from the substrate side, thereby satisfying the function of the panel. Further, when the light emitting element is white light, a color light emitting panel can be realized by using a color filter. On the other hand, in the case of blue light emission, a color light emission panel can be realized by extracting light emission through the fluorescence conversion layer.

  The organic layer used in this organic EL display is weak against moisture and needs a structure that blocks the organic layer from the outside air. In addition, in a blocked structure, a technique is known in which a desiccant is disposed in a blocked space for the purpose of adsorbing gas generated in the blocked space and removing moisture from the outside (for example, Patent Documents). 1).

  The organic EL element structure used for this organic EL display is formed on a substrate on which a color filter and a fluorescence conversion layer are formed. Therefore, there is a problem that the manufacturing process takes time. Further, the substrate on which the color filter and the fluorescence conversion layer are formed has a large surface roughness, and there is a problem that a short circuit or a leak occurs between the electrodes. Furthermore, since the outgas generated from the color filter and the fluorescence conversion layer directly passes through the organic EL element, a black spot defect called a dark spot may occur.

  For this reason, there are some which realize a color light-emitting panel by forming a color filter or a fluorescence conversion layer on a substrate on which an organic EL element is formed and a substrate facing the substrate (see, for example, Patent Documents 2 to 3).

  On the other hand, there are also those in which beads are dispersedly arranged for gap management caused by arranging a substrate on which an organic EL element is formed and a substrate on which a color filter or a fluorescence conversion layer is formed to face each other (for example, Patent Documents). 4).

Furthermore, a considerably wide gap is generated between the substrate on which the organic EL element is formed and the substrate on which the color filter or the fluorescence conversion layer is formed as compared with the case where both are formed on the same substrate. As a result, wraparound of light from adjacent pixels occurs, and the chromaticity of the organic EL display changes. In order to prevent this, a light shielding member for shielding light from other adjacent light emitting pixels may be provided between the substrate on which the organic EL element is formed and the substrate on which the color filter or the fluorescence conversion layer is formed ( For example, see Patent Document 5).
JP 2003-203761 A Japanese Patent Laid-Open No. 11-185955 JP 2001-126862 A JP 2003-517182 A JP 2002-299044 A

  However, as described above, when the color filter or the fluorescence conversion layer is disposed opposite to the substrate on which the organic EL element is formed and the opposite substrate, if the light shielding member or the beads are disposed, the manufacturing process is complicated. End up. Therefore, it is necessary to simplify the process.

  In the present invention, the gap management in the case where the color filter and the fluorescence conversion layer are arranged to face each other on the substrate on which the organic EL element is formed is easily performed by forming the spacer without increasing the number of manufacturing steps. I can do it.

  In the present invention, the number of manufacturing processes is reduced as a whole panel, and a spacer is formed between pixel positions where organic EL elements are formed without increasing the number of manufacturing processes. Leakage to the corresponding color filter or fluorescence conversion layer can be effectively prevented.

  Thus, in the present invention, it is possible to effectively suppress the occurrence of black spot defects called dark spots while shortening the manufacturing process. Since the outgas generated from the substrate on which the color filter and the fluorescence conversion layer are formed is diffused into the blocked space, the occurrence rate of black spot defects can be suppressed. And since an organic EL element is formed directly on a board | substrate, the incidence rate of a leak or a short circuit can be suppressed. Further, by forming a passivation film made of at least an inorganic substance, outgas from a color filter, an overcoat, etc. can be suppressed, and the light emission life of the organic EL element can be extended.

  In view of the above problems, the present invention proposes a structure of an organic EL display device that realizes a sufficient light emitting function while simplifying the manufacturing process.

In order to achieve the above object, the self-luminous display device of the present application is
At least one substrate;
A structure made of organic electroluminescence formed on the substrate;
A sealing plate for sealing the structure made of the organic electroluminescence,
The sealing plate is made of at least a light-transmitting substrate, and at least a color filter is provided on a substrate surface side of the sealing plate facing a substrate surface on which a structure made of the organic electroluminescence is formed. and the first black matrix is formed, the first black matrix, the thickness of that is greater than the thickness of the color filter, further, said structure, the approximate minimum of the gap between the color filter It has a thickness of 10% to 90%, and is arranged so as not to contact the substrate by providing a gap between the substrate and
Laminated on the color filter outside the display area, further have a second black matrix in contact with the substrate,
The second black matrix is provided as a spacer for controlling a gap between the structure and the color filter .

The thickness of the first black matrix may be 0.2 μm to 100 μm.

The second black matrix, the adhesive to be used in the bonding of the sealing plate and the substrate may be characterized in that a protective wall for preventing the entry of the said structure.

  The light emitting function of the EL element can be enhanced.

  FIG. 1 is a cross-sectional view of an organic EL panel used in Example 1. The organic EL panel 1 includes a substrate 2, an organic EL element 3, a sealing substrate 4, a color filter 5, a black matrix 6, a spacer 7, an overcoat 8, and a passivation layer 9 (not shown).

  The substrate 2 is an amorphous substrate such as glass or quartz, and the organic EL element 3 is formed thereon. Alternatively, an opaque crystalline substrate such as Si or GaAs may be used for the substrate 2. This is because light is extracted from the sealing substrate 4 side. Further, a substrate in which a switching element is formed on the substrate 2 may be used. In this example, Corning 1737 glass substrate is used.

The organic EL element 3 uses a fluorescent material that is a compound having a light emitting function. Such a fluorescent substance is composed of, for example, the following compounds 1 to 4.

When the organic EL element is anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / inorganic electron injection layer / cathode, the hole injection layer is N, N′-diphenyl-N, It is formed from N'-bis (N- (4-methylphenyl) -N-phenyl (4-aminophenyl))-1, 1'-bisphenyl-4,4'-diamine. The hole transport layer is formed from N, N′-diphenyl-N, N′-bis (1-naphthyl) -1,1′-diphenyl-4,4′-diamine. The light emitting layer has a lower light emitting layer and an upper light emitting layer. The lower light emitting layer is formed of a material containing a compound X represented by the following chemical formula 5 and a compound Y represented by the following chemical formula 6 in a volume ratio of 100: 3. The upper light emitting layer is formed of a material containing a compound X represented by the following chemical formula 7 and a compound Z represented by the following chemical formula 8 in a volume ratio of 100: 3. The electron transport layer is formed from tris (8-hydroxyquinoline) aluminum. The inorganic electron injection layer is formed from LiF. In this case, the thicknesses of the light emitting layer are 40 nm, the hole injection layer is 40 nm, the hole transport layer is 30 nm, the electron transport layer is 30 nm, and the inorganic electron injection layer is 0.5 nm.

  The sealing substrate 4 is disposed to face the substrate 2 and uses, for example, an amorphous substrate such as glass or quartz. In the present invention, the sealing substrate 4 side is a light extraction side, and thus has high light transmittance. Material is used. In this embodiment, a Corning 1737 glass substrate is used.

  The sealing substrate 4 only needs to have a light emission transmittance of 80% or more, and is not limited to the glass described above, and may be a transparent material such as a resin. In order to prevent moisture from entering from the outside, the sealing substrate 4 is a commercially available low-hygroscopic photocurable adhesive, epoxy adhesive, silicone adhesive, crosslinked ethylene-vinyl acetate copolymer adhesive sheet, etc. The adhesive resin layer is used to adhere and seal the substrate 2.

  In the present invention, the color filter 5 is formed at least in part or all of the display area on the sealing substrate 4 side, and color display is possible by a combination of RGB colors provided corresponding to each pixel. It is to make.

  Specifically, the color filter 5 is a color filter manufactured by Fujifilm Olin as a blue transmissive layer, a green transmissive layer, and a red transmissive layer on the sealing substrate 4, and the cut light is blue with a wavelength of 490 nm or more. Light and green are light having a wavelength of 560 nm or more and light of 480 nm or less, and red is light having a wavelength of 580 nm or less. In this embodiment, the color filters 5 are formed in stripes with a width of 100 μm. In the present embodiment, the color filter 5 is adopted, but the present invention is not limited to this, and a fluorescence conversion layer may be used.

  In this way, by forming the color filter 5 on the sealing substrate 4 side, the substrate 2 and the sealing substrate 4 can be independently put into the manufacturing process. Then, the manufacturing process can be shortened by bonding the substrate 2 and the sealing substrate 4 together. In addition, when the color filter 5 is formed on the substrate 2, problems due to surface roughness on the color filter 5 or the overcoat 8, problems of short circuit between electrodes forming the organic EL element 3, and leakage occur. This can also prevent the problem. Furthermore, the outgas generated from the color filter 5 or the overcoat 8 can be prevented from passing directly through the organic EL element 3, and the occurrence of black spot defects called dark spots can also be suppressed.

  In this embodiment, the black matrix 6 is arranged between the color filters 5 as shown in FIG. The black matrix 6 is composed of an acrylic resin film containing a black pigment. As this resin film, a film usually used for a black mask for a liquid crystal display device may be adopted. In the present embodiment, a coloring agent for blackening is added to the photosensitive resin and applied, and then a desired black matrix 6 pattern is formed using a photolithography process. The black matrix 6 is not necessarily required in the present embodiment, and may be omitted.

  The spacer 7 is provided in order to prevent the wraparound of light from adjacent pixels while maintaining the gap between the substrate 2 and the sealing substrate 4. In this embodiment, the spacer 7 is formed by the color filter 5. Specifically, in this embodiment, the spacer 7 is formed by laminating each of the blue transmission layer, the green transmission layer, and the red transmission layer.

  Thus, by forming the spacer 7 with the color filter 5, the spacer 7 can be formed between the pixel positions where the organic EL elements are formed without increasing the number of manufacturing steps. Furthermore, the spacer 7 can effectively prevent light emission from the adjacent pixel from leaking to the color filter 5 corresponding to the adjacent pixel, and display quality can be improved. In addition, the thickness of the spacer 7 should just be in the range of 1 micrometer-100 micrometers. In this embodiment, the thickness of the spacer 7 is 3 μm to 40 μm.

  The overcoat 8 is a protective layer formed so as to cover the color filter 5 and the black matrix 6. In this embodiment, the overcoat 8 is made of an ultraviolet curable acrylic resin and has a thickness of 1 μm.

  Then, a passivation layer 9 made of an inorganic material (not shown) is formed thereon with a composition SiOxNy (molar ratio: x = 1.77, y = 0.26), and a film thickness of 330 μm / min is formed to a thickness of 1 μm. It was formed by CVD (chemical vapor deposition) film formation method. At this time, the gas pressure was 90 Pa, the temperature condition was 200 ° C., the input power was 600 W (high frequency 13.56 MHz), and the GAP was 33 mm.

  Thus, in this embodiment, since the sealing substrate 4 on which the color filter 5 is formed and the substrate 2 on which the organic EL element 3 is formed are prepared, the manufacturing process is greatly shortened. In addition, since the outgas generated from the sealing substrate 4 on which the color filter 5 is formed is diffused into the blocked space, it is possible to suppress the incidence of black spot defects. Furthermore, since the organic EL element 3 is formed directly on the substrate 2, it is possible to suppress the occurrence rate of leaks and shorts. In this embodiment, the spacers 7 are formed between the pixel positions where the organic EL elements 3 are formed, thereby preventing light emitted from the adjacent pixels from leaking to the color filter 5 corresponding to the adjacent pixels. be able to.

  FIG. 2 is a cross-sectional view of an organic EL panel used in Example 2. The present embodiment is different from the first embodiment in that the black matrix 6 has a function as the spacer 7. Specifically, the black matrix 6 is disposed outside the display area (outside the pixel formation area) and between the black matrix 20 disposed between the substrate 2 and the sealing substrate 4 and within the display area (in the pixel formation area). There is a black matrix 21.

  Then, as shown in the figure, the black matrix 20 is formed by stacking the color filter 5 and the black matrix 20 outside the display area (outside the pixel formation area) so as to be thicker than the black matrix 21 in the pixel area. 7 is functioning.

  On the other hand, in the display area (in the pixel formation area), the color filters 5 and the black matrix 21 are alternately formed on the sealing substrate 4, and the thickness of the black matrix 21 is thicker than the thickness of the color filter 5. Has been. Specifically, the thickness of the black matrix 21 may be in the range of 0.2 μm to 100 μm. In this embodiment, the thickness of the black matrix 21 is 1 μm to 40 μm. Alternatively, the black matrix can be made thicker than the color filter corresponding to the pixel by directly forming the black matrix on the single-layer color filter. By comprising in this way, the improvement of the contrast of the organic electroluminescent panel 1 can be anticipated.

  Further, the thickness of the black matrix 21 is configured to have at least a thickness of about 10% to 90% of the minimum value of the gap between the organic EL element 3 and the color filter 5. By controlling the thickness of the black matrix 21 within this numerical range, it is possible to effectively prevent light emitted from an adjacent pixel from leaking to the color filter 5 corresponding to the adjacent pixel.

  As shown in the figure, the black matrix 21 is arranged so as not to contact the substrate 2 in the display area. That is, in the present embodiment, the black matrix 21 in the display area is provided not to maintain the gap between the substrate 2 and the sealing substrate 4 but to prevent light from coming from adjacent pixels. ing.

  Further, the black matrix 20 outside the display area (outside the pixel formation area) also functions as a protective wall that prevents the adhesive resin layer 51 from entering the pixel portion. The black matrix 20 is formed as a spacer 7 on the sealing substrate 4 so as to surround the pixel portion. Therefore, the black matrix 21 serves as a protective wall that prevents the adhesive resin layer 51 used when the substrate 2 and the sealing substrate 4 are bonded together from entering the organic EL element 3.

  The overcoat 8 and the passivation layer 9 may be further coated on the black matrices 20 and 21 inside and outside the display area.

  FIG. 3 is a cross-sectional view of an organic EL panel used in Example 3. The present embodiment is different from the first embodiment in that the overcoat 8 has a function as the spacer 7. That is, the overcoat 8 is formed thick so as to cover the spacer 7. Thereby, the overcoat 8 itself becomes a part of the spacer 7.

  With this configuration, in this embodiment, the flatness of the spacer 7 is improved and variations in the height of the spacer 7 can be reduced as compared with the first and second embodiments.

  The spacer 7 is formed of a color filter 5 or a black matrix 6. When formed with the color filter 5, an effect of simplifying the manufacturing process occurs, and when formed with the black matrix 6, high contrast can be realized. Furthermore, even if the spacer 7 is composed of the overcoat 8, there is an effect of simplifying the manufacturing process.

  FIG. 4 shows a bird's-eye view of the substrate on which the organic EL element 3 of the organic EL display used in the present embodiment is formed. In addition, the organic EL display 40 of a present Example is a bird's-eye view of the whole display using the organic EL panel 1 demonstrated in Example 1 thru | or 3.

  Specifically, auxiliary wiring 41, electrode 42, edge cover layer 43, opening 44, cathode lead-out wiring 45, anode lead-out wiring 46, contact pad formation region 47 and sealing material region 48 are formed on the substrate 2. Yes.

  The auxiliary wiring 41 and the electrode 42 are respectively disposed on the substrate 2 as shown in the figure, and the edge cover layer 43 is covered thereon except for the opening 44 and the sealing material. An anode lead-out wiring 46 is routed to each pixel via a cathode lead-out wiring 45 and a contact pad forming region 47, and a sealing material region 48 surrounds the display area.

  In this embodiment, the electrode 42 forming the organic EL element 3 is not particularly limited, but is an electrode for injecting holes. The electrode 42 is not particularly limited, but ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), ZnO, SnO2, In2O3, or the like is used. Particularly preferably, ITO (tin-doped indium oxide) or IZO (zinc-doped indium oxide) is used. Further, a reflective electrode may be formed under the ITO. In this embodiment, pixels of 256 dots × 64 lines (one pixel 300 × 300 μm) are configured.

  The electrode 10 (not shown) for forming the organic EL element 3 is not particularly limited, but in the present embodiment, an electrode for injecting electrons, and a low work function material is preferable. For example, there are simple metal elements such as K, Li, Na, Mg, La, Ce, Ca, Sr, Ba, Al, Ag, In, Sn, Zn, and Zr. In order to improve the stability, it is preferable to use a two-component or three-component alloy system containing them. Examples of the alloy system include Ag · Mg (Ag: 0.1 to 50 at%), Al·Li (Li: 0.01 to 14 at%), In · Mg (Mg: 50 to 80 at%), Al · Ca ( Ca: 0.01 to 20 at%) is preferable. Moreover, the electrode 10 needs to have translucency, and preferably includes a laminated structure of ZnO—Al (aluminum-doped zinc oxide) and a low work function.

  In the organic EL element 3, excitons are generated in the organic EL element 3 due to recombination of holes injected from the electrode 42 and electrons injected from the electrode 10 (not shown). In the process of recombination, light is emitted, and this light passes through the electrode 10 (not shown) and the sealing substrate 4 and is emitted to the outside.

  The detailed description of each pixel is as follows. As shown in the enlarged pixel view 49, the edge cover layer 43 is covered on the electrode 42 electrically connected to the auxiliary wiring 41, and the opening 44 is opened. A plurality of such pixels are configured to realize an organic EL display 40 for color display.

  Specifically, in this embodiment, the organic EL panel 1 is formed in a pattern of 256 × 64 dots (pixels) and driven with a line sequential drive voltage of 15V.

  The auxiliary wiring 41 is not particularly limited, but is electrically connected to the anode lead-out wiring 46 in this embodiment. The cathode lead-out wiring 45 is patterned in accordance with the contact pad formation region 47. In this drawing, the contact pad formation region 47 is a portion where the cathode lead wiring 45 is covered with the edge cover layer 43 and is opened by a part of the cathode lead wiring 45.

  5A and 5B are conceptual diagrams of an organic EL display used in the present embodiment. FIG. 5A is a plan view of the organic EL display 40, and FIG. 5B is a cross-sectional view taken along the line C-C 'of FIG. 5A. As shown in FIG. 5B, in the organic EL display 40, a sealing substrate 4 is bonded to the organic EL panel 1, and a sealing gas is filled between the substrates. This is to prevent deterioration of the organic layer and electrodes, and the sealing substrate 4 is sealed by using the adhesive resin layer 51 in the sealing material region 48 shown in FIG. 5A in order to prevent moisture from entering. The substrate 4 is bonded to the substrate 2 and sealed.

  The sealing gas is preferably an inert gas such as Ar, He, or N2. The moisture content of the sealing gas is preferably 100 ppm or less, more preferably 10 ppm or less, and particularly preferably 1 ppm or less. Although there is no lower limit to this water content, it is usually about 0.1 ppm. In addition, you may arrange | position a desiccant outside a display area as needed. Moreover, if it is a transparent or translucent desiccant, you may arrange | position in a display area.

  As shown in FIG. 5A, the organic EL display 40 has a cathode lead-out wiring 45 and an anode lead-out wiring 46, and the connection between the cathode lead-out wiring 45 and the electrode 10 is shown in FIG. 5B. In this manner, the contact pad is formed in the contact pad formation region 47. The color filter 5 and the spacer 7 are formed as shown in FIG.

  The adhesive resin layer 51 is an adhesive used when the substrate 2 and the sealing substrate 4 are bonded to each other. In the second embodiment, the adhesive resin layer 51 can prevent entry into the pixel portion. Specifically, the black matrix 6 is formed on the sealing substrate 4 so as to surround the pixel portion in a matrix. The black matrix 6 functions as a protective wall that prevents the adhesive resin layer 51 from entering the pixel portion.

  FIG. 6 is a conceptual diagram of a self-luminous display device used in this embodiment. The self-luminous display device 60 is configured by attaching a scanning signal driver IC 61, a scanning signal driver circuit 62, a video signal driver IC 63, a video signal driver circuit 64, an FPC 65, and a controller 66 to the organic EL display 40.

  The scanning signal driver IC 61 is a driver that transmits a signal to the cathode lead-out wiring 45, and includes a scanning signal driver circuit 62. The video signal driver IC 63 is a driver that transmits a signal to the anode lead-out wiring 46, and includes a video signal driver circuit 64. Each driver circuit is connected to the controller 66 via the FPC 65. The controller 66 is a controller that controls display data to be displayed on the organic EL display 40.

  In the present invention, various modifications can be made as necessary. For example, in the first embodiment, the black matrix 5 is not necessary.

  In the present invention, it is also possible to use a substrate in which a switching element is formed on a substrate on which a structure including an organic electroluminescence element is formed.

  Further, in Example 3, various members can be selected for the spacer 7, and can be selected from the color filter 5, the black matrix 6, the overcoat 8, and the passivation layer 9.

  INDUSTRIAL APPLICABILITY The present invention relates to an image display device represented by organic EL image display, and can be used for color displays such as portable devices and TVs.

1 is a cross-sectional view of an organic EL panel used in Example 1. FIG. 6 is a cross-sectional view of an organic EL panel used in Example 2. FIG. 6 is a cross-sectional view of an organic EL panel used in Example 3. FIG. It is a bird's-eye view of the board | substrate with which the light emitting layer of the organic electroluminescent display used for this Embodiment is formed. It is a conceptual diagram of the organic electroluminescent display used for this Embodiment. It is a conceptual diagram of the self-light-emitting display device used in this embodiment.

Explanation of symbols

1 Organic EL Panel 2 Substrate 3 Organic EL Element 4 Sealing Substrate 5 Color Filter 6 Black Matrix 7 Spacer 8 Overcoat 9 Passivation Layer 10 Electrode 20 Black Matrix (Outside Display Area)
21 Black matrix (in the display area)
40 Organic EL Display 41 Auxiliary Wiring 42 Electrode 43 Edge Cover Layer 44 Opening 45 Cathode Leading Wiring 46 Anode Leading Wiring 47 Contact Pad Forming Area 48 Sealing Material Area 49 Pixel Enlarged View 51 Adhesive Resin Layer 60 Self-Emitting Display Device 61 Scanning Signal driver IC
62 Scanning Signal Driver Circuit 63 Video Signal Driver IC
64 Video signal driver circuit 65 FPC
66 controller

Claims (3)

At least one substrate;
A structure made of organic electroluminescence formed on the substrate;
A sealing plate for sealing the structure made of the organic electroluminescence,
The sealing plate is made of at least a light-transmitting substrate, and at least a color filter is provided on a substrate surface side of the sealing plate facing a substrate surface on which a structure made of the organic electroluminescence is formed. and the first black matrix is formed, the first black matrix, the thickness of that is greater than the thickness of the color filter, further, said structure, the approximate minimum of the gap between the color filter It has a thickness of 10% to 90%, and is arranged so as not to contact the substrate by providing a gap between the substrate and
Laminated on the color filter outside the display area, further have a second black matrix in contact with the substrate,
A self-luminous display device, wherein the second black matrix is provided as a spacer for controlling a gap between the structure and the color filter .   The self-luminous display device according to claim 1, wherein the first black matrix has a thickness of 0.2 μm to 100 μm. The second black matrix, the adhesive to be used in the bonding of the substrate and the sealing plate, according to claim 1 or 2, characterized in that a protective wall for preventing the entry of the said structure A self-luminous display device as described in 1.

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