JP2008186681A - Organic electroluminescent display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL display device in which deterioration due to effect of water can be prevented and which has high reliability. <P>SOLUTION: A sealing substrate 3 has a recess 11 in which a jetty 10 is formed at the periphery opposing to an element substrate 1 and in which a space 9 is formed between the sealing substrate 3 and a display part constituted of an organic EL element 2, corner regions 8 in which four sides of a recess part 11 intersect are made to form a flat face shape protruded outside in the direction separating from the display region, and an application type moisture absorbing material 4 is formed at the border of the recess part 11, as seen from the sealing substrate 3 side, a gap is installed between the corner of the display region and the application type moisture absorbing material 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to an organic electroluminescence display device in which a first substrate having a display region in which light emitting elements are arranged is sealed with a light-transmitting second substrate.

  Unlike a liquid crystal display device that requires a backlight, an organic electroluminescence (hereinafter referred to as organic EL) display device is self-luminous, so it is thinner, wider in viewing angle, and faster in response time than a liquid crystal display device. It has features such as excellent video display. The basic structure of the organic EL element constituting the organic EL display device is a sandwich structure in which the organic EL light emitting layer is sandwiched between two electrodes, and the organic EL light emitting layer emits light by passing a current between the electrodes. A first substrate (element substrate) in which a plurality of pixel circuits composed of the organic EL elements are two-dimensionally arranged to form a display region, and a second substrate (sealing substrate: sealed) that seals the first display region. An organic EL display device is formed by incorporating a drive circuit or the like into an organic EL panel constituted by a stop cap.

  The bottom emission structure takes out light emission through a transparent first substrate (element substrate) on which a pixel circuit composed of organic EL elements is formed, and a translucent seal that hermetically seals the surface on which the pixel circuit is formed. The top emission structure takes out emitted light from the stop substrate (sealing cap) side. The bottom emission structure has a low aperture ratio due to light shielding by a drive circuit composed of drive elements that control the pixels and various wirings that supply scan signals, data signals (display signals), or display currents to the drive elements. It is difficult to make it high. On the other hand, the top emission structure is not easily affected by the light shielding on such a structure, and the aperture ratio can be increased, so that the top emission structure is suitable for high definition.

  Further, in the organic EL display device, a so-called dark spot (non-light emitting portion) may be generated due to moisture intrusion into the organic EL element. Therefore, in general, an element (an organic EL element or a light emitting element) that constitutes an organic EL display device with a sealing cap (made of metal or glass) on which a moisture absorbent that absorbs moisture or a desiccant is molded and mounted in a sheet form or the like is mounted. Is also sealed in a low moisture concentration atmosphere to prevent moisture from entering the organic EL element. Patent Document 1 discloses a structure in which a concave portion is formed in a sealing cap, and a hygroscopic material on a film is attached to the inner surface of the concave portion to perform confidential sealing.

  FIG. 12 is a cross-sectional view illustrating a structural example of a conventional organic EL display device having a bottom emission structure. The conventional organic EL display device shown in FIG. 12 is a sealing in which an element substrate 501 such as glass on which a display circuit (organic EL display circuit) 502 composed of organic EL elements is formed, and a sheet-like hygroscopic material 505 are provided inside. A cap 506 is sealed with a sealing material 503. A recess 507 is dug inside the sealing cap 506, and a sealing material 503 is disposed between the jetty 511 and the element substrate 501. And the sheet-like moisture absorption material 505 is accommodated in the recessed part 507. A sealing space 504 is provided so that the sheet-like hygroscopic material 505 does not contact the organic EL display circuit 502 when the sealing cap 506 is sealed on the element substrate 501 having the organic EL display circuit (display region) 502. .

  In the organic EL display device having this configuration, when the sealing cap 506 side is set as an observation surface, the light emission is blocked by the sheet-like hygroscopic material 505, and thus the light emission 508 of the organic EL display circuit (display region) 502. In general, a bottom emission structure is used in which the substrate is taken out from the element substrate 501. In this structure, since the aperture ratio is limited by shielding wiring such as a drive circuit (not shown) formed on the element substrate 501, it is difficult to obtain high luminance when the definition is increased.

  As a sealing technology corresponding to the top emission structure, a coating type hygroscopic material is spirally formed in a region where the organic EL element is not shielded, and a flat element substrate and a sealing cap are fixed with a sealing material to form a confidential structure. Japanese Patent Application Laid-Open No. H10-228473 discloses a device that extracts emitted light through a light sealing cap.

  FIG. 13 is a diagram for explaining an organic EL display device having a conventional top emission structure in which a coating type hygroscopic material is disposed between a wall surface of a recess and an organic EL element using a sealing cap having a recess. 13A is a plan view, and FIG. 13B is a cross-sectional view taken along the line AA in FIG. 13A. In the straight line portion 107 of FIG. 13A, the coating type moisture absorbent 104 is away from the display area constituted by the organic EL element 102 and does not interfere with the organic EL element 102. However, as shown in the figure, the planar shape of the recess is rectangular (rectangular) and the corner is rounded (R: curvature), so at the time of the recess (wrinkle, corner along the inner side of the recess) When the coating type moisture absorbent material 104 is formed along the corner area 108, as shown in the corner area 108, the coating type moisture absorbent material 104 interferes with the organic EL element 102 and blocks the emitted light 106.

  In order to prevent light shielding by the coating type hygroscopic material 104 in the corner area 108, the distance between the sealing material 105 and the organic EL element 102 is increased as viewed on a plane (the pixel area is narrowed or the frame (sealed from the pixel area is sealed). It is necessary to increase the distance) to the outer shape of the cap. In order to prevent light shielding of the corner portion by the coating type moisture absorbent material 104, for example, as shown in the corner region 109, a pattern in which the coating type moisture absorbent material 104 is opened at the corners may be used. However, since the pattern tends to be fattened at the open end, it may interfere with the organic EL element 102, and there may be a shortage of local water collection capability due to the open pattern. Note that a glass substrate is used for the sealing cap 103 and digging is performed using hydrofluoric acid.

  FIG. 14 shows a relationship between a hygroscopic material and an organic EL element in a corner region in an organic EL display device in which a coating type hygroscopic material is arranged between the wall surface of the recess and the organic EL element using a conventional digging-shaped sealing cap. It is a principal part top view for demonstrating the positional relationship for preventing interference. Conventionally, when forming the engraved portion of the sealing cap, if the width of the coating type hygroscopic material 104 is w and the radius of the corner central pattern is Rd, the innermost coordinate of the coating type hygroscopic material 104 is C It becomes. In order to prevent the corner of the organic EL element 102 from interfering with this point, a distance n from the inner side surface of the coating type moisture absorbent 104 is required. This hinders narrowing the frame. Incidentally, when Rd = 1 mm and w = 0.5 mm, n needs to be about 0.22 mm or more.

  In FIG. 14, symbol A is a moisture absorbent corner start coordinate, B is a moisture absorbent corner end coordinate, C ′ is an inner straight line extension intersection coordinate of the moisture absorbent, D is a seal cap digging corner corner start coordinate, and E is Sealing cap digging part corner end coordinates, Rc is the sealing cap digging part corner center radius, and m is the distance from the recess (digging part) of the sealing cap to the outer side surface of the hygroscopic material.

As a sealing technique corresponding to the top emission structure other than the above, there is a technique in which a light-absorbing hygroscopic film is formed on a light-transmitting flat substrate and sealed with an element substrate using a sealing material. Patent Document 3 discloses the disclosure.
Japanese Patent Application Laid-Open No. 09-148066 JP 2004-6286 A JP 2003-142256 A

  In the technique disclosed in Patent Document 1, since the emitted light is shielded by the sheet moisture absorbent, the bottom emission structure is an object. In order to make this technology compatible with the top emission structure, a sheet desiccant may be mounted in a space that does not interfere with the organic EL element. However, it is difficult to secure a space for mounting a required amount of sheet desiccant, and it is necessary to increase the frame (distance from the effective pixel region to the outer shape of the sealing cap) to secure the space, which makes it difficult to narrow the frame. .

  In the technique disclosed in Patent Document 2, since a coating type hygroscopic material is formed in a spiral shape in a region where the organic EL element is not shielded from light, it is necessary to provide a large space from the organic EL element to the sealing material. Since the hygroscopic material is formed in a spiral shape, it is particularly difficult to narrow the frame because the corner region enters the inside.

  According to the technique disclosed in Patent Document 3, a film that does not optically affect the emitted light because of the structure in which a hygroscopic material film is formed facing the entire surface on which the organic EL element is formed and the emitted light is extracted through the hygroscopic material. It is very difficult to stably form a wide range.

  The present invention has been made in view of the above circumstances, and its object is to provide a highly reliable and high-definition capable of preventing deterioration due to the influence of moisture and to increase the ratio of the effective display area to the panel outer shape. The object is to provide an organic EL display device.

  In order to achieve the above-described object, the present invention has a planar shape in which a corner of a concave portion (digging portion) formed in the sealing cap protrudes outward in a direction away from the display area, and along the concave portion. A hygroscopic material was coated.

  More specifically, the present invention relates to a rectangular element substrate having a display area in which a plurality of light emitting elements are arranged, and a sealing substrate that covers the display area and seals the display area of the element substrate. And a sealing material provided around the outer peripheral portion of the opposing surface of the element substrate and the sealing substrate to seal the element substrate with the sealing substrate. The sealing substrate has a recess that forms a jetty at a peripheral edge facing the element substrate to form a space between the display region and at least one corner region of the recess is the display region. A planar shape projecting outward in a direction away from the surface, and a moisture absorbing material is formed at the time of the recess, and when viewed from the sealing substrate side, a gap is formed between the corner of the display area and the moisture absorbing material. It can have.

  Further, according to the present invention, the concave portion of the sealing substrate has a curved shape in which the four sides warp outward from each other when seen from the plane, and the corners intersecting the four sides protrude outward, and the pin cushion type as a whole. And having a hygroscopic material formed to follow the planar shape of the concave portion along the concave portion.

  Further, according to the present invention, the planar shape of the recess of the sealing substrate is such that most of the four sides are parallel to the four sides of the sealing substrate and are separated from the corners of the display region only at the corners where the four sides intersect. The hygroscopic material has a shape in which one side of the hygroscopic material protrudes from the projecting portion of the recess in the corner region, and the other side of the hygroscopic material comes into contact with the hygroscopic material on the one side. it can.

  Further, according to the present invention, the corner region of the concave portion of the sealing substrate can be shaped so as to protrude outward from a straight line, and the hygroscopic material can be continuously formed along the protrusion.

  Further, according to the present invention, the corner region of the concave portion of the sealing substrate can be shaped so as to protrude outward from a straight line, and a moisture absorbent material pattern can be continuously formed along the protrusion.

  The present invention also provides a rectangular element substrate having a display region in which a plurality of light emitting elements are arranged and a drive circuit for driving the light emitting elements, and a seal that covers the display region and seals the display region of the element substrate. And a sealing material provided around the outer edge of the opposing surfaces of the element substrate and the sealing substrate and sealing the element substrate with the sealing substrate. The sealing substrate has a recess that forms a jetty at a peripheral edge facing the element substrate to form a space between the display region and the drive circuit, and at least one corner region of the recess is The planar shape is projected outward in a direction away from the display area, and a hygroscopic material is formed at the concave portion, and when viewed from the sealing substrate side, between the corner of the display area and the hygroscopic material. It is possible to have a gap.

  By causing the corner of the recess of the sealing substrate to protrude outward and forming the coating type hygroscopic material along the recess, interference with the organic EL element is avoided. In addition, since the effective display area can be increased with respect to the outer shape of the organic EL panel, and the moisture absorbing material is formed on the entire outer periphery of the panel, the moisture that has entered the panel from the outside is effectively absorbed, Thus, it is possible to obtain a highly reliable and high-definition organic EL display device in which the deterioration problem due to the influence of the above is improved.

  According to the present invention, since the emitted light is extracted only through the glass surface (the etched surface: recessed portion), the emitted light is not deteriorated and can be manufactured more stably than when a transparent film or the like is formed.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the scope of the technical idea of the present invention. . Therefore, it is needless to say that the present invention is not construed as being limited to the description of the embodiments below.

  FIG. 1 is a diagram for explaining Example 1 of an organic EL display device having a top emission structure according to the present invention. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along the line AA in FIG. In FIG. 1, a display region composed of a large number of organic EL elements 2 is formed on the main surface of the element substrate 1, and a sealing substrate (hereinafter referred to as a sealing cap) 3 is formed on the jetty 10 constituting the peripheral edge of the recess 11. It is hermetically fixed with a sealing material 5 interposed. The corner 7 of the recess 11 of the sealing cap 3 has a shape protruding outward in a direction away from the display area in which the organic EL element 2 is disposed. There is a space 9 between the recess 11 and the organic EL element 2.

  That is, the concave portion 11 of the rectangular sealing cap 3 has four corners projecting in the angular direction of the sealing cap 3 when the four sides intersect when viewed in a plane, and the entire planar shape is a pin cushion shape. By forming the coating type moisture absorbent material 4 (hereinafter referred to as a moisture absorbent material) along the recess 11 (the root of the ridge: the corner), the moisture absorbent material 4 also follows the shape of the recess 11. It is a cushion type. Thus, the hygroscopic material 4 does not interfere with the display area composed of the organic EL elements 2 in the corner area 8, and the emitted light 6 is extracted to the observation side without being blocked by the hygroscopic material 4.

  FIG. 2 illustrates a positional relationship for preventing interference between the moisture absorbing material and the organic EL element at the corner when the sealing cap according to the first embodiment of the organic EL display device having the top emission structure according to the present invention is used. It is a principal part top view for doing. In FIG. 2, the organic EL element 2 is formed on the main surface of the element substrate, and a sealing cap 3 including a hygroscopic material 4 disposed at a position outside thereof is hermetically fixed by a sealing material. Although the sealing material is applied to the outside of the recess, the illustration is omitted.

  Reference symbol A is a start coordinate of a hygroscopic corner when a conventional sealing cap is used. A 'is a corner start coordinate for setting the innermost coordinate of the corner to C'. B is the coordinates of the end of the hygroscopic corner when a conventional sealing cap is used. B 'is a corner end coordinate for setting the innermost corner coordinate to C'. C ′ is the coordinate of the extension of the inner straight portion of the hygroscopic material, D is the concave corner start coordinate of the conventional sealing cap, and D ′ is the concave corner start coordinate for setting the corner innermost coordinate to C ′. E is a recess corner end coordinate of a conventional sealing cap, E ′ is a recess corner end coordinate for setting the innermost coordinate of the corner to C ′, Rd is a hygroscopic material corner center radius, Rc is a sealing cap recess corner center radius, L1 is the distance in the Y direction from the hygroscopic material straight portion to A ', L2 is the X direction distance from the hygroscopic material straight portion to B', m is the distance from the recess of the sealing cap to the outer side surface of the hygroscopic material, and w is the moisture absorption Material pattern width, Xd is the shift amount in the X direction from A → A ′ and B → B ′, Yd is the shift amount in the Y direction from A → A ′ and B → B ′, and Xc is D → D ′ and E → E ′. X direction shift amount, Yc is the shift amount of D → D ′ and E → E ′, and S is the absolute value of the shift amount.

  In Example 1, the inner straight portion of the hygroscopic material is extended to the innermost coordinate of the hygroscopic material corner by shifting the corner start coordinates of the hygroscopic material 4 from A → A ′ and the corner end coordinates from B → B ′. The coordinate C ′ of the intersecting point can be set. In the sealing cap 3, the corner start coordinates are shifted from D → D ′ and the corner end coordinates are shifted from E → E ′ accordingly. The absolute value S of the shift amount is common and S <| Xc | = | Yc | = | Xd | = | Yd | is set so that the innermost coordinate of the hygroscopic material corner is placed outside C ′. Can do. If the width of the hygroscopic material is w and the corner radius of the central pattern of the hygroscopic material is Rd, the shift amount S is S = (Rd−w / 2) (√2-1) / √2.

  Further, if the radius Rc of the corner of the sealing cap satisfies the relationship of Rc <Rd + w / 2 + m, where m is the distance between the recess (wrinkle) of the sealing cap and the outer side surface of the hygroscopic material 4, the sealing cap The hygroscopic material 4 can be formed without protruding from the sealing material forming surface. The center coordinate of the corner radius Rc of the sealing cap is arranged outside the corner coordinate Rd of the hygroscopic material toward the corner (the values of Xc and Yc also need to be changed accordingly), etc. By moving the sealing cap recess corner to the outside, it is possible to further suppress the moisture absorbing material 4 from protruding to the sealing material forming surface.

  Since the taper angle becomes gentler when the distance L1 in the Y direction from the straight line portion of the moisture absorbent material 4 to the corner start coordinate A ′ and the distance L2 in the X direction from the corner end coordinate B ′ to the straight line portion become larger, the moisture absorbent material. Becomes easier to form. Considering the formation limit of the moisture absorbent 4 application device, at least L1 and L2 should be larger than the corner radius Rd. In addition, the Y direction distance from the straight line portion of the concave portion of the sealing cap to the corner start coordinate D ′ and the X direction distance from the corner end coordinate E ′ to the straight line portion of the concave portion of the sealing cap are also L1 and L2. preferable.

  Next, a method for manufacturing an organic EL panel constituting the organic EL display device having a top emission structure according to the present invention will be described with reference to FIGS. First, (1) film formation and patterning are repeated to form a TFT (Thin Film Transistor) drive circuit, a lower electrode 202 and a pixel isolation film 237 on the element substrate 201 (FIG. 3). That is, an amorphous silicon film 232 is formed on the lower insulating film (base film) 231 on the main surface of the element substrate 201 (FIG. 3A), and is modified to polysilicon by excimer laser irradiation or the like. This is patterned into an island-shaped thin film transistor active layer 232 '.

  A gate electrode 233, a source / drain electrode 234, an interlayer insulating film 235, a passivation film 236, a lower electrode 202 of an organic EL element, and a pixel isolation film 237 are formed on the polysilicon film as the active layer 232 ′ (FIG. 3 ( b)). Although a polysilicon TFT is used here, an amorphous silicon TFT may be used as long as there is no problem in driving.

  (2) On the lower electrode 202, the organic light emitting layer 203 and the upper electrode 204 are laminated | stacked, and the organic EL element 205 is formed (FIG. 4).

  (3) When the concave portion of the sealing cap 206 having a concave portion having a corner protruding outward is formed, the moisture absorbing material 207 is formed so as not to enter the opposing pixel region (FIG. 5).

As the moisture absorbing material 207, an application type moisture absorbing material (zeolite, CaO or the like in paste form) is applied by a dispenser method or the like, temporarily dried, and then baked and cured. For example, when a zeolite paste is used, temporary drying is performed at 120 ° C. for 30 minutes (in the air), and calcination is performed at 300 to 400 ° C. for 60 minutes (in the air), and then 300 to 400 in dry N ₂ . Heat at 60 ° C. for 60 minutes to remove moisture. The hygroscopic material coating pattern is formed, for example, with a width of 100 to 1000 μm, a height of 50 to 300 μm, and a corner radius of 0.5 to 1 mm. Further, the depth of the concave portion of the sealing cap is adjusted to the thickness of the glass substrate to be used. For example, when a glass substrate having a thickness of 0.7 mm is used, the depth of the concave portion is set to 100 to 350 μm.

  (4) A sealing material 208 is formed around the sealing cap 206 (FIG. 6). A dispenser method and screen printing are used for the sealing material application method, and a UV curable resin or the like is used for the material of the sealing material.

  (5) The element substrate 201 and the sealing cap 206 are bonded together so that the organic EL element 205 and the hygroscopic material 207 face each other, and the sealing material 208 is cured (FIG. 7). Note that the sealing material preferably contains a spacer for controlling the distance between the element substrate 201 and the sealing cap 206.

  According to the first embodiment, the interference of the coating-type hygroscopic material with respect to the pixel region is suppressed, and the effective display region can be further increased with respect to the outer shape of the organic EL panel. In addition, because a moisture absorbent material is formed on the entire panel outer periphery, it effectively absorbs moisture that has entered the panel from the outside and improves the deterioration problem due to the influence of moisture. An apparatus can be obtained.

  FIG. 8 is a plan view for explaining Example 2 of the organic EL display device having a top emission structure according to the present invention. In the second embodiment, the concave portion formed in the sealing cap 303 has a shape protruding outward at the corner region 307. That is, in Example 2, the planar shape of the recesses corresponding to the four sides of the sealing cap 303 is such that most of the four sides are parallel to the four sides of the sealing cap 303 and from the corner of the display region only in the corner region. It protrudes outward in the direction of leaving.

  The pattern of the sealing material 305 is formed only by straight lines (the corners are rounded), and the hygroscopic corner portion 306 protrudes from the protruding portion of the concave portion on one side (here, the parallel long side), and absorbs moisture on the short side. The shape is such that the material comes into contact with the hygroscopic material on the long side. Further, if the moisture absorption capacity of the moisture absorbent material is sufficient, the moisture absorbent material on the long side and the moisture absorbent material on the short side may not be necessarily in contact with each other in the corner region but may be opposed with an open gap. Note that when the moisture absorbent material on the short side and the long side is crossed at the corner, it becomes thicker than the digging depth of the recess, causing the moisture absorbent material to contact the element substrate and to protrude into the seal formation area Therefore, it is better not to cross the cross.

  Also according to the second embodiment, the interference of the coating-type hygroscopic material with respect to the pixel region is suppressed, and the effective display region can be made larger with respect to the outer shape of the organic EL panel. In addition, because a moisture absorbent material is formed on the entire panel outer periphery, it effectively absorbs moisture that has entered the panel from the outside and improves the deterioration problem due to the influence of moisture. An apparatus can be obtained.

  FIG. 9 is a plan view for explaining Example 3 of the organic EL display device having a top emission structure according to the present invention. In Example 3, the corner area 307 of the concave portion included in the sealing cap 303 was shaped so as to protrude outward from the straight line, and the moisture absorbent material pattern was formed continuously along the protrusion. Thereby, the hygroscopic material corner 308 is moved away from the organic EL element, and interference with the display area made of the organic EL element is avoided.

  Also in the third embodiment, the interference of the coating-type hygroscopic material with respect to the pixel region is suppressed, and the effective display region can be made larger with respect to the outer shape of the organic EL panel. In addition, because a moisture absorbent material is formed on the entire panel outer periphery, it effectively absorbs moisture that has entered the panel from the outside and improves the deterioration problem due to the influence of moisture. An apparatus can be obtained.

  FIG. 10 is a plan view for explaining Example 4 of the organic EL display device having a top emission structure according to the present invention. In Example 4, the corner region 309 of the concave portion of the sealing cap has a shape that protrudes outward only on one of the intersecting sides, and the pattern of the sealing material 305 is formed by only a straight line (the corners are rounded), and the hygroscopic material The corner portion 306 of 304 has a shape in which one side is in contact with the other side while gradually narrowing.

  Also in this embodiment, the two sides of the hygroscopic material may be discontinuous at the corner portion 306 of the hygroscopic material, and a gap may be formed between them, or the other edge is applied to the side surface of one edge. It is good.

  Also according to the fourth embodiment, the interference of the coating-type hygroscopic material with respect to the pixel region is suppressed, and the effective display region can be further increased with respect to the outer shape of the organic EL panel. In addition, because a moisture absorbent material is formed on the entire panel outer periphery, it effectively absorbs moisture that has entered the panel from the outside and improves the deterioration problem due to the influence of moisture. An apparatus can be obtained.

  FIG. 11 is a plan view for explaining Example 5 of the organic EL display device having a top emission structure according to the present invention. In this embodiment, the present invention is applied to an element substrate in which a drive circuit is built together with an organic EL element circuit. When the driving circuit 406 is arranged in the sealing space, the shape of the concave portion of the sealing cap 403 is projected outward only in the corner region 407 near the organic EL element (display region). The hygroscopic material 404 is also formed in a shape along the concave portion so that the hygroscopic material 404 does not shield the corners of the display area. On the other hand, the corner shape of the sealing cap 403 in the corner region 408 near the drive circuit is a shape that is rounded by chamfering the intersection of two sides of a conventional rectangle consisting of four sides. In addition, since the structure does not extract emitted light above the driving circuit 406, the amount of the moisture absorbing material 404 mounted can be increased by forming the moisture absorbing material 404 at a position 409 facing the driving circuit 406. The pattern of the hygroscopic material 404 at that time may be one in which the lines are continuous, one in which the lines are formed discontinuously, or one in which adjacent lines are spread and mixed to form a solid coating.

  Also in the fifth embodiment, the interference of the coating-type hygroscopic material with respect to the pixel region is suppressed, and the effective display region can be made larger with respect to the outer shape of the organic EL panel. In addition, because a moisture absorbent material is formed on the entire panel outer periphery, it effectively absorbs moisture that has entered the panel from the outside and improves the deterioration problem due to the influence of moisture. An apparatus can be obtained.

  Next, the layer structure and materials of the organic EL element will be described. The top emission type organic EL element includes an upper electrode transparent to a visible light region, an organic light emitting layer, and a light reflective lower electrode. There are configurations in which the lower electrode is a cathode and the upper electrode is an anode, and the lower electrode is an anode and the upper electrode is a cathode. In any case, a material having high visible light permeability is used for the upper electrode. A material having a transmittance of 80% or more (preferably 90% or more) in the entire visible light region is suitable. In the structure of the lower electrode as the cathode and the upper electrode, the lower electrode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / upper electrode are laminated in this order. When the lower electrode is an anode and the upper electrode is a cathode, the lower electrode / electron injection layer / electron transport layer / light emitting layer / hole transport layer / hole injection layer / upper electrode are formed in this order. However, in the above configuration, the electron injection layer, the hole injection layer, the electron transport layer, or the hole transport layer may be omitted.

  When the lower electrode is a cathode and the upper electrode is an anode, a conductive film material having a small work function that enhances electron injection efficiency is desirable for the lower electrode. Specific examples include aluminum, aluminum / neodymium alloy, and magnesium silver alloy. The upper electrode 4 is an oxide mainly composed of indium oxide, and is preferably a transparent conductive film such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). The formation is performed by sputtering, EB vapor deposition, ion plating, or the like. On the other hand, when the lower electrode 2 is an anode and the upper electrode is a cathode, materials similar to those described above are used for the anode and the cathode, but the cathode of the upper electrode needs to be translucent. In the case where a conductive film material such as a metal material having a low work function is used, the conductive film material is thinned so that the visible light transmittance is at least 80% or more. For example, the film thickness is 15 nm or less. Alternatively, a structure in which a transparent conductive film material is stacked over a conductive film material such as a metal material may be used.

  As a material of each layer of the organic light emitting layer laminated between the lower electrode and the upper electrode, the following materials can be used.

  Examples of the electron injection layer include lithium fluoride, magnesium fluoride, calcium fluoride, strontium fluoride, barium fluoride, magnesium oxide, and aluminum oxide. A vacuum evaporation method or the like is used for the film formation.

  Examples of the material for the electron transport layer include tris (8-quinolinol) aluminum, oxadiazole derivatives, silole derivatives, and zinc benzothiazole complexes. The formation is performed by a vacuum evaporation method or the like.

  In the light emitting layer, there are a case where the host material to be formed itself emits light and a case where the dopant material added to the host in a small amount emits light. As host materials, distyrylarylene derivatives (DPVBi), silole derivatives having a benzene ring in the skeleton (2PSP), oxodiazole derivatives having a triphenylamine structure at both ends (EM2), verinone derivatives having a phenanthrene group (P1) ), Oligothiophene derivative (BMA-3T) having triphenylamine structure at both ends, berylene derivative (tBu-PTC), tris (8-quinolinol) aluminum, polybaraphenylene vinylene derivative, polythiophene derivative, polybaraphenylene derivative, Examples include polysilane derivatives and polyacetylene derivatives. Examples of dovant materials include quinacridone, coumarin 6, nile red, luprene, 4- (dicyanomethylene) -2-methyl-6- (para-dimethylaminostyryl) -4H-pyran (DCM), dicarbazole derivatives, and the like. is there. The formation is performed by a vacuum evaporation method, a co-evaporation method, or the like.

  As a material of the hole transport layer, N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′diamine (TPD), 4,4 '-Bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD), 4,4', 4 "-tri (N-carbazolyl) triphenylamine (TCTA), 1,3,5 -Tris [N- (4-diphenylaminophenyl) phenylamino] benzene (p-DPA-TDAB) etc. These are formed using a vacuum deposition method or the like.

  Examples of the material for the hole injection layer include steel phthalocyanine, star perst amine compound, polyaniline, polythiophene, and the like. The formation is performed by a vacuum evaporation method or the like.

  As a method for forming each layer of the organic light emitting layer, a vacuum evaporation method or the like is used for forming a single material, and a co-evaporation method or the like is used when a plurality of materials are used.

  Although the example using zeolite and CaO has been described above as the hygroscopic material, other chemical hygroscopic substance particles, metal complex compounds, and physical adsorption substance particles can be used. Further, a photo-curing resin or the like can be used for the sealing material.

  The organic EL display device according to the present invention can be any electronic device having a monitor for displaying an image, such as a monitor for checking an image of a digital camera, a digital video camera, a mobile phone, a personal computer, or the like. It can also be implemented in electronic equipment. In addition, this invention is not limited to the structure of the above-mentioned Example, and it cannot be overemphasized that a various change is possible, without deviating from the technical idea of this invention.

It is a figure explaining Example 1 of the organic electroluminescence display of the top emission structure which concerns on this invention. The essential point for explaining the positional relationship for preventing interference between the hygroscopic material and the organic EL element in the corner region when the sealing cap according to Example 1 of the organic EL display device having the top emission structure according to the present invention is used. FIG. It is a figure explaining the manufacturing method of the organic electroluminescent panel which comprises the organic electroluminescent display apparatus of the top emission structure which concerns on this invention. It is a figure explaining the manufacturing method of the organic electroluminescent panel which comprises the organic electroluminescent display apparatus of the top emission structure which concerns on this invention. It is a figure explaining the manufacturing method of the organic electroluminescent panel which comprises the organic electroluminescent display apparatus of the top emission structure which concerns on this invention. It is a figure explaining the manufacturing method of the organic electroluminescent panel which comprises the organic electroluminescent display apparatus of the top emission structure which concerns on this invention. It is a figure explaining the manufacturing method of the organic electroluminescent panel which comprises the organic electroluminescent display apparatus of the top emission structure which concerns on this invention. It is a top view explaining Example 2 of the organic electroluminescence display of the top emission structure which concerns on this invention. It is a top view explaining Example 3 of the organic EL display device of the top emission structure which concerns on this invention. It is a top view explaining Example 4 of the organic electroluminescence display of the top emission structure which concerns on this invention. It is a top view explaining Example 5 of the organic EL display device of the top emission structure concerning this invention. It is sectional drawing explaining the structural example of the organic EL display apparatus of the conventional bottom emission structure. It is a figure explaining the organic EL display device of the conventional top emission structure using the sealing cap in which the recessed part was formed. It is a principal part top view for demonstrating the positional relationship for preventing the moisture absorption material and organic EL element in a corner part in the organic EL display apparatus using the conventional digging-shaped sealing cap.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Element board | substrate, 2 ... Organic EL element, 3 ... Sealing board | substrate (sealing cap), 4 ... Coating type hygroscopic material, 5 ... Sealing material, 6 ... Light emission , 7 ... recess, 8 ... corner area, 9 ... space, 10 ... jetty, 11 ... recess.

Claims (6)

A rectangular element substrate having a display region in which a plurality of light emitting elements are arranged; a sealing substrate that covers the display region and seals the display region of the element substrate; and the element substrate and the sealing substrate A sealing material provided around the outer edge of the opposing surface and sealing the element substrate with the sealing substrate;
The sealing substrate has a recess that forms a jetty on a peripheral edge facing the element substrate to form a space between the display region,
A shape in which at least one corner of the recess protrudes outward in a direction away from the display area, and a moisture absorbing material is formed along the recess.
An organic electroluminescence display device having a gap between a corner of the display region and the hygroscopic material when viewed from the sealing substrate side. In claim 1,
The concave portion of the sealing substrate is a curved shape in which the four sides warp outward from each other when seen from a plane, and the angle at which the four sides intersect protrudes outward, and is a pincushion shape as a whole,
An organic electroluminescence display device comprising a hygroscopic material formed along the concave portion to follow the planar shape of the concave portion. In claim 1,
The planar shape of the concave portion of the sealing substrate is such that most of its four sides are parallel to the four sides of the sealing substrate and project outward in a direction away from the corner of the display area only at the corner where the four sides intersect. And
In the corner region, the hygroscopic material has a shape in which one side protrudes from the protruding portion of the recess and the other side abuts against and contacts the hygroscopic material on the one side. . In claim 1,
An organic electroluminescence display device, wherein the corner region of the concave portion of the sealing substrate has a shape protruding outward from a straight line, and the hygroscopic material is continuously formed along the protrusion. A display area formed by arranging a plurality of light emitting elements; a rectangular element substrate having a drive circuit for driving the light emitting elements; a sealing substrate that covers the display area and seals the display area of the element substrate; A sealing material provided around the outer edge portion of the opposing surface of the element substrate and the sealing substrate, and sealing the element substrate with the sealing substrate,
The sealing substrate has a recess that forms a jetty on the periphery facing the element substrate to form a space between the display region and the drive circuit,
A planar shape in which at least one corner of the recess protrudes outward in a direction away from the display area, and a moisture absorbent material is formed along the recess.
An organic electroluminescence display device having a gap between a corner of the display region and the hygroscopic material when viewed from the sealing substrate side. In claim 5,
An organic electroluminescence display device, wherein a larger amount of the hygroscopic material is mounted in a concave portion of the sealing substrate facing the driving circuit than in other regions.

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