JP2010153171A - Organic el device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a highly reliable organic EL device which can improve a sealing nature. <P>SOLUTION: In the organic EL device having a display zone as a zone where an image is formed and an outer peripheral section 99 for surrounding the display zone 100 on one surface of an element substrate 10, wherein a first electrode 25, a second electrode 27, and a light-emitting function layer 26 including at least an EL material layer sandwiched between the first electrode 25 and the second electrode 27 are provided in the display zone 100, and also having organic EL elements 29 for emitting luminescence 48 of the light-emitting function layer 26 via the second electrode 27, a partition 77 for partitioning adjacent organic EL elements 29, auxiliary wiring 20 formed on an upper face of the partition 77 and electrically connected with the second electrode 27, and a partition layer 85 for covering the partition 77 and the organic EL element 29, a projected section 79 is formed on the upper face of the partition 77. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL device.

  2. Description of the Related Art In recent years, organic EL (electroluminescence) devices that form images by causing organic EL elements regularly arranged in a display region to emit light have been put to practical use as display devices used in display units of electronic devices such as mobile phones. It is out. The organic EL element includes a pair of electrodes including a pixel electrode (anode) independent for each organic EL element disposed on the element substrate side on which the drive element is formed, and a cathode (common electrode) facing the pixel electrode. And a light emitting functional layer including at least an organic EL layer sandwiched between the pair of electrodes. In recent years, in order to improve the luminance and the like by effectively using the above-described light emission, a top emission type organic EL device that extracts light emission from the cathode side has been increasingly adopted.

  One of the problems in top emission type organic EL devices is the resistance of the cathode. The cathode is generally formed on the entire display area. In order to achieve both transparency and conductivity, the layer is formed of an extremely thin metal layer having a thickness of several nanometers to several tens of nanometers, or ITO (indium oxide / tin alloy) having a higher resistance than metal. And has a high sheet resistance (sheet resistance). Therefore, in the vicinity of the center of the display area, a phenomenon may occur in which the amount of current supplied to the organic EL element is reduced due to a voltage drop and display quality is deteriorated. For this reason, for example, in Patent Document 1, auxiliary cathodes as a plurality of auxiliary wirings that are electrically connected to the cathodes on the surface on the counter substrate side of the partition walls that partition between the organic EL elements and that extend in parallel to each other. A method for forming a wiring by mask vapor deposition is proposed. Since the auxiliary cathode wiring is loosely limited in the layer thickness (dimension in the normal direction of the element substrate), the above-described sheet resistance can be reduced, and the deterioration of display quality can be alleviated.

JP 2007-265756 A

  However, there is a problem that the formation of the above-described auxiliary cathode wiring may affect the reliability. In the mask vapor deposition step, the vapor deposition mask needs to be in close contact with a partition that insulates between adjacent pixel electrodes. At that time, defects caused by interference between the partition walls and the vapor deposition mask may eventually cause cracks or the like in the passivation layer. 7 and 8 show the manner of occurrence of such cracks. 7 and 8 are diagrams corresponding to FIGS. 4 and 5 in the embodiment of the present invention described later, and the names of the respective components are described in the description of FIGS. 1 to 6 described later. Therefore, only cracks that may occur in the passivation layer will be described, and descriptions of individual components and symbols will be partially omitted.

  FIGS. 7A to 7E show the occurrence of cracks in a top emission type organic EL device using the light emitting functional layer 26 that emits one of the three primary colors. In the drawing, a red light emitting functional layer 26R and a green light emitting functional layer 26G are shown. The light emitting functional layer 26 is formed only in the recesses (openings) between the partition walls 77, and is not formed on the upper surface of the partition walls 77. The alphabet at the end of each code represents R = red, G = green, and B = blue. In the following description, when the corresponding colors are not distinguished, that is, when the generic name is indicated, the alphabet is omitted. In the following description, the side opposite to the substrate (element substrate) 10 side is referred to as “upper surface” or “upper layer”.

  FIG. 7A shows a state in which the auxiliary cathode wiring 20 is formed by covering the vapor deposition mask 21 so as to be in close contact with the partition wall 77. FIG. 7B is a cross-sectional view taken along line C-C ′ of FIG. 7C shows a state in which the vapor deposition mask 21 is separated from the partition wall 77, FIG. 7D shows a state in which the cathode 27 is formed on the light emitting functional layer 26 and the partition wall 77, and FIG. The state in which the passivation layer 85 is formed is shown.

  As shown in FIGS. 7A and 7B, every other auxiliary cathode wiring 20 is formed on the partition wall 77 between the organic EL elements 29. Therefore, in the region where the auxiliary cathode wiring 20 is not formed on the upper surface of the partition wall 77, the partition wall 77 and the vapor deposition mask 21 are in surface contact. Here, in such a contact portion, there is no problem if both the partition wall 77 and the vapor deposition mask 21 are perfectly smooth, but if there is a protrusion or the like on either side, the reliability of the organic EL device will be lowered in the future. Will be allowed to. When the mask protrusion 22 is locally present on the vapor deposition mask 21 as shown in FIG. 7B, the partition wall scratches 24 are formed on the upper surface of the partition wall 77 as shown in FIG. 7C. When the cathode 27 is formed on the partition wall 77 on which the partition wall scratches 24 are formed, cracks 17 may be generated in the cathode as shown in FIG. Such a crack similarly causes the crack 17 in the passivation layer 85 formed on the upper surface of the cathode 27 as shown in FIG. The crack 17 impairs the sealing performance of the passivation layer 85 and becomes a moisture infiltration path. As a result, the light emitting function of the organic EL element 29 in the vicinity of the crack is lost over time, and the formation position of the organic EL element becomes a so-called dark spot.

  8A to 8E show the generation of cracks 17 when the partition wall 77 is not smooth rather than the vapor deposition mask 21. FIG. In the organic EL device shown in the figure, a white light emitting functional layer 26 </ b> W that emits white light, which is common among the organic EL elements 29, is formed on the entire surface of the substrate (element substrate) 10 including the upper surface of the partition wall 77. . Further, the flatness of the upper surface of the partition wall 77 is slightly impaired, and the local thick film portion 23 exists.

  FIG. 8A shows a state in which the auxiliary cathode wiring 20 is formed by covering the vapor deposition mask 21 so as to be in close contact with the white light emitting functional layer 26 </ b> W formed on the partition wall 77. FIG. 8B is a cross-sectional view taken along line D-D ′ of FIG. 8C shows a state in which the vapor deposition mask 21 is separated from the partition wall 77, FIG. 8D shows a state in which the cathode 27 is formed on the upper layer of the white light emitting functional layer 26W and the partition wall 77, and FIG. The state in which the passivation layer 85 is formed on the upper layer is shown.

  As shown in FIG. 8B, the white light emitting functional layer 26 </ b> W is strongly pressed by the local thick film portion 23 and the vapor deposition mask 21 at a position where the local thick film portion 23 exists. Therefore, a part of the white light emitting functional layer 26 </ b> W is in close contact with the vapor deposition mask 21. When the vapor deposition mask 21 is released from this state, as shown in FIG. 8C, a part of the white light emitting functional layer 26W is peeled from the partition wall 77, and the surface of the partition wall 77 is exposed. When the cathode 27 is formed on the entire surface of the substrate (element substrate) 10 including the upper surface of the partition wall 77 in such a state, a crack 17 is generated in the cathode as shown in FIG. Such cracks cause the same crack 17 in the passivation layer 85 formed in the upper layer of the cathode 27, and eventually cause dark spots.

  The present invention has been made in order to obtain a highly reliable organic EL device by suppressing the above-described problems, that is, the generation of cracks 17 due to the formation of the auxiliary cathode wiring 20 and the generation of dark spots due to the cracks. Yes, it can be realized as the following forms or application examples.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A display area which is an area where an image is formed and an outer peripheral portion surrounding the display area are provided on one surface of the substrate, and the first electrode and the second electrode are included in the display area. And a light emitting functional layer including at least an EL material layer sandwiched between the first electrode and the second electrode, and the light emission of the EL material layer is emitted through the second electrode. An organic EL element to be separated, a partition wall separating the adjacent organic EL elements, an auxiliary wiring formed on the upper surface of the partition wall and electrically connected to the second electrode, the partition wall and the organic EL element An organic EL device comprising: a passivation layer covering the organic EL device, wherein a convex portion is formed on an upper surface of the partition wall.

  With such a configuration, when the auxiliary cathode is formed, the mask can be supported by the convex portion, and therefore it is possible to suppress a locally strong pressure from being applied to the upper surface of the partition wall. Therefore, damage to the second electrode or the light emitting functional layer can be suppressed, and the reliability of the organic EL device can be improved.

  Application Example 2 In the organic EL device described above, the top of the convex portion has a curved surface shape.

  With such a configuration, when supporting the mask, it is possible to suppress a strong local pressure from being applied to the upper surface of the partition wall and to make the pressure applied to the convex portion extremely uniform. Therefore, it is possible to more effectively suppress the second electrode or the light emitting functional layer from being damaged, and the reliability of the organic EL device can be improved.

  Application Example 3 In the organic EL device described above, the convex portion is formed of a material that can be deformed when a force is applied to the apex of the convex portion.

  With such a configuration, it is possible to more effectively suppress the application of strong local pressure on the upper surface of the partition wall when the mask is supported. Therefore, it is possible to more effectively suppress the second electrode or the light emitting functional layer from being damaged, and the reliability of the organic EL device can be improved.

  Application Example 4 In the above-described organic EL device, the partition wall is formed in an annular shape so as to surround the display region on the outer peripheral portion, and the density of the protrusions is set in the display region. An organic EL device characterized in that the density in the outer peripheral portion is higher than the density.

  With such a configuration, the above-described damage in the outer peripheral portion can be further suppressed. Since the penetration of moisture and the like is from the outer peripheral portion, an organic EL device with further improved reliability can be obtained.

  Hereinafter, an embodiment of an organic EL device will be described with reference to the drawings. The embodiments described below include a first embodiment and a second embodiment, both of which are characterized by the function of a convex portion 79 (see FIG. 2) formed on the upper surface of the partition wall 77. Therefore, first, an overview of the organic EL device according to both embodiments will be described, and then the function and effect of the convex portion 79 will be described. In the drawings shown below, the dimensions and ratios of the components are appropriately different from the actual ones in order to make the components large enough to be recognized on the drawings.

(First embodiment)
FIG. 1 is a circuit configuration diagram of an organic EL device common to an organic EL device 1 according to the first embodiment, an organic EL device 2 according to a second embodiment described later, and the conventional organic EL device described above. It is. The organic EL device 1 includes a display area 100 and an outer peripheral part. In the display region 100, a plurality of scanning lines 102 extending in the X direction, a plurality of signal lines 104 extending in the Y direction, and a plurality of power supply lines 106 extending in the Y direction are formed. Yes. An organic EL pixel 30 is formed for each section in which the X direction is defined by the signal line 104 and the power supply line 106 and the Y direction is defined by the center line of the scanning line 102.

  The organic EL pixel 30 is classified into a red organic EL pixel 30R, a green organic EL pixel 30G, and a blue organic EL pixel 30B according to the color of the emitted light, and these three types of organic EL pixels 30 are included in the display region 100. It is regularly formed.

  Each organic EL pixel 30 holds a switching TFT (thin film transistor) 108 to which a scanning signal is supplied to the gate electrode via the scanning line 102 and an image signal supplied from the signal line 104 via the switching TFT 108. A holding capacitor 110, a driving TFT 112 to which an image signal held by the holding capacitor 110 is supplied to the gate electrode, an organic EL element 29 (see FIG. 3) in which a driving current flows from the power supply line 106 via the driving TFT 112, and the like Consists of.

  There are also three types of organic EL elements 29 depending on the color of the emitted light, and each corresponds to the three types of organic EL pixels 30 described above. In the organic EL device 1 of the present embodiment, the color of the above-described emitted light is obtained by the material for forming the organic EL layer in the light emitting functional layer 26. However, as will be described later, a color filter layer 80 is also provided to improve color purity. On the other hand, in the organic EL device 2 described later, the color filter layer 80 (see FIG. 3) changes the white light into one of the three primary colors and emits it. Therefore, the organic EL element 29 is common among the three types of organic EL pixels 30. The three types of organic EL pixels 30 described above have the same elements other than the organic EL element 29.

  A scanning line driving circuit 120 and a signal line driving circuit 130 are formed in an outer peripheral portion that is a peripheral area of the display area 100. The scanning line driving circuit 120 sequentially supplies scanning signals to the scanning line 102 in accordance with various signals supplied from an external circuit (not shown). The signal line driver circuit 130 supplies an image signal to the signal line 104. A pixel drive current is supplied to the power supply line 106 from an external circuit (not shown). The operation of the scanning line driving circuit 120 and the operation of the signal line driving circuit 130 are synchronized with each other by a synchronization signal supplied from an external circuit via the synchronization signal line 140.

  When the scanning line 102 is driven and the switching TFT 108 is turned on, the potential of the signal line 104 at that time is held in the holding capacitor 110, and the level of the driving TFT 112 is determined according to the state of the holding capacitor 110. Then, a driving current flows from the power supply line 106 to the pixel electrode 25 (see FIG. 2) via the driving TFT 112, and the organic EL element 29 emits light according to the magnitude of the driving current.

  FIG. 2 is a schematic cross-sectional view of the organic EL device 1 of the present embodiment. The organic EL device 1 according to the present embodiment and the organic EL device 2 according to the second embodiment to be described later are characterized by the cross-sectional shape of the partition wall 77 that partitions between adjacent organic EL elements 29. Therefore, in this figure, the partition 77, three types of organic EL elements 29 (R, G, B) partitioned by the partition, and a driving TFT for driving the organic EL element (hereinafter simply referred to as “TFT”). .) A cross section of 112 and the like is displayed, and the switching TFT 108 and the storage capacitor 110 are not shown. Hereinafter, description will be made in order from the element substrate 10 side.

  On the element substrate 10, the TFT 112 is formed together with the switching TFT 108 and the storage capacitor 110 (not shown) described above. The TFT 112 includes a semiconductor layer 31, a gate electrode 33 formed by patterning the same layer as the scanning line 102, a gate insulating layer 70 formed between the semiconductor layer 31 and the gate electrode 33, and the like. A region of the semiconductor layer 31 that overlaps with the gate electrode 33 is a channel region 38, and a source region 35 and a drain region 36 are formed on both sides of the channel region.

  An interlayer insulating layer 71 made of silicon nitride or silicon oxide is formed on the counter substrate 11 side of the TFT 112. The source region 35 is electrically connected to the source electrode 53 through a contact hole (without reference numeral) formed by locally etching the interlayer insulating layer 71. Similarly, the drain region 36 is connected to the interlayer insulating layer 71. Is electrically connected to the drain electrode 54 through a contact hole (not shown) formed by locally etching the electrode. A first protective layer 73 and a planarizing layer 72 made of silicon nitride are sequentially stacked on the source electrode 53 and the drain electrode 54.

  A reflective layer 28 is formed in a predetermined region in the upper layer of the planarizing layer 72. The “predetermined region” is a region including a region where the organic EL element 29 will be formed in the future. The light emitted from the organic EL element 29 is emitted in half in the upward and downward directions. On the other hand, the organic EL device 1 of this embodiment is a top emission type, and has a display region 100 (see FIG. 1) only in the upward direction. Therefore, the light emitted from the organic EL element 29 is reflected in the upper layer direction by the reflective layer 28 to effectively use the light emitted. Therefore, the region where the reflective layer 28 is formed needs to include at least a region where the organic EL element 29 will be formed in the future.

  The material for forming the reflective layer 28 is preferably a material having high reflectivity and excellent workability (patterning property). In the organic EL device 1, the reflective layer 28 uses Al (aluminum). The upper surface of the reflective layer 28 is covered with a second protective layer 74 made of silicon nitride. The second protective layer functions to protect the reflective layer 28 when a pixel electrode 25 described later is formed.

  A pixel electrode as a first electrode formed by patterning an ITO (indium oxide / tin alloy) layer in an island shape so as to cover the reflective layer on the upper surface of the planarizing layer 72 including the formation region of the reflective layer 28 25 is formed. The pixel electrode 25 is formed for each individual organic EL pixel 30 (see FIG. 1), and the adjacent pixel electrodes 25 are partitioned by a partition wall 77.

  The partition wall 77 has a layer thickness (dimension in the Z direction) of approximately 2.0 μm and a width (dimension in the X direction) of approximately 15.0 μm, and the photosensitive resin layer is patterned so as to be tapered as illustrated. Is formed. A region surrounded by the partition wall (no symbol), that is, a region where the pixel electrode 25 is exposed is a region where the organic EL element 29 is formed in the future. In the organic EL device 1 according to this embodiment, the upper surface of the partition wall is not flat, and a convex portion 79 is formed. The convex portion has a bowl-shaped cross section. Therefore, the partition 77 provided in the organic EL device 1 (and the organic EL device 2) does not have a flat upper surface unlike the partition of the conventional organic EL device. The dimensions of the convex portion 79 are approximately 0.1 μm in the thickness (height) direction and approximately 5.0 μm in the width (dimension in the X direction). Such a shape is obtained by so-called half exposure at the time of patterning the above-described photosensitive resin layer. The function of the convex portion 79 will be described later.

  In the region surrounded by the partition wall 77, that is, the upper layer of the pixel electrode 25, a different light emitting functional layer 26 is formed for each of the three types of organic EL elements 29 (R, G, B). Specifically, a red light emitting functional layer 26R is formed on the red organic EL element 29R, a green light emitting functional layer 26G is formed on the green organic EL element 29G, and a blue light emitting functional layer 26B is formed on the blue organic EL element 29B. Is formed. Each light emitting functional layer 26 is formed by laminating a total of five layers of a hole injection layer, a hole transport layer, an organic EL layer, an electron transport layer, and an electron injection layer in this order from the element substrate 10 side. Each of the emission colors is obtained from a material for forming the organic EL layer.

  On the upper surface of the partition wall 77, an auxiliary cathode wiring 20 for supplementing the conductivity of the cathode 27 described later is formed so as to cover the convex portion 79. The material for forming the auxiliary cathode wiring 20 needs high conductivity, that is, low resistance for the purpose of formation, and is formed of Al or the like in the organic EL device 1 of the present embodiment. In the organic EL device 1 of the present embodiment, the auxiliary cathode wirings 20 are not formed on the entire top surface of the partition wall 77 but are formed every other wall with respect to the partition wall 77 extending in the Y direction. Yes. Therefore, in the cross section perpendicular to the Y direction as shown in this figure, the partition walls 77 where the auxiliary cathode wiring 20 is not formed are located on both sides of the partition wall 77 where the auxiliary cathode wiring 20 is formed.

  The auxiliary cathode wiring 20 is preferably formed by a vapor deposition method using a mask as described in [Background] above. Besides the vapor deposition method, an ion plating method, a sputtering method, an ion beam method, or the like can also be used. In any of the above methods, a mask is required. In order to limit the formation region to the upper surface of the partition wall 77, the mask needs to be in close contact with the partition wall 77.

  On the upper surface of the light emitting functional layer 26 on which the auxiliary cathode wiring 20 is formed, a cathode 27 as a second electrode is formed. Since the organic EL device 1 is a top emission type organic EL device, the cathode 27 needs to have conductivity or transparency or transflective properties. On the other hand, the cathode 27 needs to be formed of a material having a work coefficient lower than that of the material for forming the pixel electrode 25. Therefore, it is preferable to form the layer with a very thin Al or MgAg (magnesium / silver) alloy having a layer thickness of several nm to several tens nm.

  Since the cathode 27 is formed on the entire surface of the element substrate 10, a stacked body of the pixel electrode 25, the light emitting functional layer 26 and the cathode 27 is formed in a region surrounded by the partition wall 77. Such a laminate is the organic EL element 29 (R, G, B). The cathode 27 is formed at least over the entire display area 100 (see FIG. 1) and has a zero potential. Therefore, when a voltage is applied to the pixel electrode 25, a current corresponding to the voltage flows through the light emitting functional layer 26. The organic EL layer included in the light emitting functional layer 26 emits light according to the amount of current and is emitted as light emission 48.

  As described above, since the cathode 27 is made of an extremely thin metal material, it has a high sheet resistance. Therefore, in the vicinity of the center of the display region 100, the voltage applied to the pixel electrode 25 is reduced due to the voltage drop, and the above-described phenomenon that the light emission amount is reduced may occur. The auxiliary cathode wiring 20 is an element formed to suppress such a voltage drop, and has a function of reducing the surface resistance by substantially increasing the thickness of the cathode 27 on the upper surface of the partition wall 77.

  A passivation layer 85 is formed on the cathode 27 in order to protect the organic EL element 29 and the like. The passivation layer 85 preferably has a three-layer structure including an inorganic material layer, an organic material layer, and an inorganic material layer. The element substrate 10 formed up to the passivation layer is bonded to the counter substrate 11 via the adhesive layer 78 and the peripheral sealing material 13 (see FIG. 6). A color filter layer 80 is disposed on the surface of the counter substrate 11 facing the element substrate 10, and a circularly polarizing plate 88 for suppressing external light reflection is disposed on the surface opposite to the above surface. ing. The circularly polarizing plate 88 is a laminate of a linearly polarizing plate and a quarter wavelength correction plate (an element that gives a quarter wavelength phase difference between orthogonal polarization components). When light is reflected, the external light reflected by the above-described reflective layer or the like is prevented from being emitted from the display region 100 by utilizing the property that the rotation direction of polarized light is reversed.

  The color filter layer 80 includes three types (three colors) of color filters 81 (a red color filter 81R, a green color filter 81G, and a blue color filter 81B), and a black matrix 82 formed between the color filters 81. Become. As described above, since the organic EL device 1 according to this embodiment forms the light emitting functional layer 26 for each light emission color of the organic EL element 29, the color filter 81 (R, G, B) is not essential. . However, the color filter 81 can further improve color purity and display quality. The region where the black matrix 82 is formed substantially coincides with the region where the partition wall 77 is formed in a plan view and suppresses color mixing between adjacent organic EL elements 29.

(Second Embodiment)
Next, an organic EL device according to the second embodiment will be described. The function of the convex portion 79 will be described later together with the first embodiment and the second embodiment. FIG. 3 is a schematic cross-sectional view of the organic EL device 2. The organic EL device 2 according to this embodiment is a top emission type organic EL device similar to the organic EL device 1, and includes elements similar to those of the organic EL device 1 except for the light emitting functional layer 26. Therefore, the same reference numerals are assigned to the common elements, and a part of the description is omitted.

  As shown in the drawing, in the organic EL device 2, a white light emitting functional layer 26 </ b> W is formed on the upper surface of the partition wall 77 and the entire surface of the element substrate 10 on which the pixel electrode 25 is formed. Therefore, the organic EL elements 29 cannot be distinguished by the emission color and are all common. The types of organic EL pixels 30 (see FIG. 1), that is, the three types of emission colors are obtained only by the function of the color filter layer 80. Therefore, the color filter layer 80 of the organic EL device 2, in particular, the three color filters 81 (R, G, B) excluding the black matrix 82 is formed darker than the color filter of the organic EL device 1.

  Convex portions 79 are formed on the upper surface of the partition wall 77 in the same manner as the upper surface of the partition wall of the organic EL device 1. Therefore, the white light emitting functional layer 26 </ b> W is formed on the upper surface of the partition wall 77 so as to cover the convex portion. The auxiliary cathode wiring 20 is formed in the upper layer of the white light emitting functional layer.

(Effect of the convex part of the organic EL device according to the embodiment)
4A to 4E are diagrams showing the function and effect of the convex portion 79 in the organic EL device 1 according to the first embodiment, and correspond to FIG. 7 used in the above description of [Background]. It is a figure to do. FIG. 4A shows a state in which the auxiliary cathode wiring 20 is formed by covering the vapor deposition mask 21 so as to be in close contact with the partition wall 77. FIG. 4B is a cross-sectional view taken along the line AA ′ in FIG. 4C shows a state in which the vapor deposition mask 21 is separated from the partition wall 77, FIG. 4D shows a state in which the cathode 27 is formed on the light emitting functional layer 26 and the partition wall 77, and FIG. The state in which the passivation layer 85 is formed is shown. Here, a mask protrusion 22 exists in a partial region of the surface of the vapor deposition mask 21 on the partition wall 77 side as shown in the figure.

  As shown in FIG. 4A, convex portions 79 are regularly formed on the upper surface of the partition wall 77 between the adjacent organic EL elements 29. Then, as shown in FIG. 4B, the vapor deposition mask 21 used for forming the auxiliary cathode wiring 20 is disposed on the element substrate 10 so as to be in close contact with the convex portion 79. Specifically, the vapor deposition mask 21 is supported by the apex of the convex part 79 having a bowl-shaped cross-sectional shape. Here, the upper surface of the partition wall 77 does not have a completely flat surface within the substrate surface of the element substrate 10, and the same applies to the surface of the vapor deposition mask 21 on the partition wall 77 side. Therefore, in the process of forming the auxiliary cathode wiring 20 in the conventional organic EL device, pressure by the vapor deposition mask 21 can be applied to a part of the upper surface of the partition wall 77 distributed in the plane of the element substrate 10. However, the convex portion 79 included in the organic EL device 1 according to the present embodiment has a bowl shape in cross section and has a vertex. That is, the vertex of the convex part 79 has a curved surface shape. The vertex can be slightly deformed. Therefore, most of the convex portions 79 distributed in the surface of the element substrate 10 come into contact with the vapor deposition mask 21 substantially uniformly, and a strong pressure is applied only to a partial region of the upper surface of the partition wall 77. It is suppressed.

  Further, since the mask protrusion 22 exists only in a very partial region in the surface of the vapor deposition mask 21 on the partition wall 77 side, there is little possibility that the mask protrusion 22 and the apex of the convex portion 79 overlap in plan view. Furthermore, unlike the upper surface of the partition wall 77 of the conventional organic EL device, the apex of the convex portion 79 can be slightly deformed in the lateral direction, that is, the surface direction of the element substrate 10. Therefore, even when it overlaps with the mask protrusion 22 in plan view, the possibility of the partition wall scratches 24 (see FIG. 7) due to pressure is very low. Therefore, in the stage where the deposition mask 21 is separated from the element substrate 10 after the auxiliary cathode wiring 20 is formed as shown in FIG. Does not occur. Therefore, as shown in FIG. 4D, the cathode 27 having no crack 17 (see FIG. 7) is formed in the partition wall 77 even though the auxiliary cathode wiring 20 is formed using the vapor deposition mask 21 having the mask protrusions 22. Can be formed on top.

  Further, as shown in FIG. 4E, a passivation layer 85 having no cracks 17 can be formed on the upper layer of the cathode 27. As described above, when the crack 17 exists in the passivation layer 85, moisture can penetrate through the crack. Such moisture can cause the organic EL element 29 in the vicinity of the crack to lose its function and generate a so-called dark spot. In the organic EL device 1 according to the present embodiment, since the convex portion 79 is formed on the upper surface of the partition wall 77, the passivation without the crack 17 is formed even though the auxiliary cathode wiring 20 is formed by the mask vapor deposition method. Layer 85 can be formed. As a result, the organic EL device 1 according to the present embodiment can have both high display quality due to the auxiliary cathode wiring 20 and high reliability due to the passivation layer 85 having no cracks 17.

  Next, the function and effect of the convex part 79 in the organic EL device 2 according to the second embodiment will be described. FIGS. 5A to 5E are views showing the function and effect of the convex portion 79 in the organic EL device 2 according to the second embodiment, and correspond to FIG. 8 used in the above description of [Background]. It is a figure to do.

  FIG. 5A shows a state in which the auxiliary cathode wiring 20 is formed by covering the vapor deposition mask 21 so as to be in close contact with the partition wall 77. FIG. 5B is a cross-sectional view taken along line B-B ′ of FIG. 5C shows a state in which the vapor deposition mask 21 is separated from the partition wall 77, FIG. 5D shows a state in which the cathode 27 is formed on the light emitting functional layer 26 and the partition wall 77, and FIG. The state in which the passivation layer 85 is formed is shown.

  As shown in FIG. 5B, local thick film portions 23 are dotted on the upper surface of the partition wall 77 of the organic EL device 2 in the same manner as the partition wall 77 described in FIG. Since the white light emitting functional layer 26 </ b> W is also formed on the upper surface of the partition wall 77, when the vapor deposition mask 21 is brought into close contact with the partition wall 77, the white light emitting functional layer 26 </ b> W is It will be sandwiched in the direction (Z direction). However, in the organic EL device 2, the upper surface of the partition wall 77 is not flat, and a convex portion 79 is formed. Therefore, as long as the above-mentioned local thick film part 23 is not located at the top of the convex part, the white light emitting functional layer 26W is not strongly pressed by the vapor deposition mask 21 and the local thick film part 23.

  Further, even when the local thick film portion 23 is located at the apex of the convex portion 79, the elasticity of the convex portion 79 suppresses local contact between the vapor deposition mask 21 and the partition wall 77. The white light emitting functional layer 26 </ b> W is suppressed from being strongly pressed by the vapor deposition mask 21. Further, in the vicinity of the apex of the convex portion 79, the local thick film portion 23 itself is formed to have an apex, unlike the local thick film portion in the conventional organic EL device, so that it is added to the white light emitting functional layer 26W. The pressure can escape to the surroundings.

  Therefore, as shown in FIG. 5C, when the formation of the auxiliary cathode wiring 20 is completed and the vapor deposition mask 21 is separated from the element substrate 10, the white light emitting functional layer 26W at the location where the local thick film portion 23 is generated. The occurrence of peeling and the like is suppressed.

  Therefore, as shown in FIG. 5D, the crack 17 (see FIG. 8) is not formed in the upper layer of the white light emitting functional layer 26W even though the local thick film portion 23 exists on the upper surface of the partition wall 77. The cathode 27 can be formed. Further, as shown in FIG. 5E, a passivation layer 85 having no cracks 17 can be formed on the upper layer of the cathode 27.

  As described above, the crack 17 can cause a dark spot. In the organic EL device 2 according to the present embodiment, since the convex portion 79 is formed on the upper surface of the partition wall 77, even if the local thick film portion 23 is generated during the patterning of the partition wall 77, the passivation without the crack 17 is caused. Layer 85 can be formed. As a result, the organic EL device 2 according to the present embodiment can have both high display quality and high reliability by the auxiliary cathode wiring 20.

  Next, the formation density of the convex portions 79 common to the organic EL device 1 according to the first embodiment and the organic EL device 2 according to the second embodiment will be described. 6A to 6D show the formation density of the convex portions 79 in the display region 100 and the outer peripheral portion 99 of the organic EL device 1 and the organic EL device 2 (hereinafter simply referred to as “organic EL device”). It is a figure which shows the difference. Specifically, FIG. 6A is a cross-sectional view in a direction perpendicular to the element substrate 10, and FIG. 6B is a diagram illustrating an arrangement of each region in the substrate surface of the element substrate 10, FIG. 6C and FIG. 6D are diagrams showing the formation density of the convex portions 79.

  As shown in FIG. 6A and the above-described FIG. 2 and the like, the organic EL device includes an element substrate 10, a peripheral sealing material 13, and a counter substrate 11 having a circularly polarizing plate 88 attached to one surface. In the space formed by such elements, a color filter layer 80, an inner element group 14, an outer element group 15, and a partition wall layer 16 are formed. The area where the inner element group 14 is formed is the display area 100, and the area where the outer element group 15 is formed is the outer peripheral portion 99. As shown in FIG. 6B, the outer peripheral part 99 is formed so as to surround the display area 100 concentrically. A region around the outer peripheral portion 99 is a region where the peripheral sealing material 13 is formed.

  Here, the inner element group 14 is a general term for the switching TFT 108, the storage capacitor 110, the driving TFT 112, and the like formed in the display region 100, and the outer element group 15 is a scanning formed in the outer peripheral portion 99. A generic term for elements forming the line drive circuit 120, the signal line drive circuit 130, and the like. The partition wall layer 16 is a general term for partition walls 77 that partition between the organic EL elements 29 in the display region 100 and a resin layer (no symbol) that covers the outer element group 15 in the outer peripheral portion 99.

  FIG. 6C shows the convex portion 79 formed on the partition wall layer 16 in the outer peripheral portion 99, and FIG. 6D shows the convex portion 79 formed on the partition wall layer 16 in the display region 100. ing. The convex portions 79 in the outer peripheral portion 99 are formed with a density approximately twice that of the convex portions 79 in the display region 100.

  Due to such a density difference, the organic EL device according to both the above-described embodiments can widely disperse the pressure applied to the convex portion 79 in the plane of the element substrate 10 and can suppress deformation of the convex portion. Further, moisture that may cause dark spots penetrates mainly from the interface between the substrate (the element substrate 10 and the counter substrate 11) and the peripheral sealing material. Therefore, by increasing the formation density of the convex portions 79 in the outer peripheral portion 99, generation of cracks and the like in the outer peripheral portion 99 can be further suppressed, and the reliability can be further improved.

The figure which shows the circuit structure of the organic electroluminescent apparatus concerning 1st Embodiment. 1 is a schematic cross-sectional view of an organic EL device according to a first embodiment. The schematic cross section of the organic electroluminescent apparatus of 2nd Embodiment. The figure which shows the function and effect of the convex part in the organic electroluminescent apparatus concerning 1st Embodiment. The figure which shows the function and effect of a convex part in the organic electroluminescent apparatus concerning 2nd Embodiment. The figure which shows the difference in the formation density of a convex part. The figure which shows generation | occurrence | production of the crack in the conventional organic EL apparatus. The figure which shows generation | occurrence | production of the crack in the conventional organic EL apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Element substrate, 11 ... Counter substrate, 13 ... Peripheral sealing material, 14 ... Inner element group, 15 ... Outer element group, 16 ... Partition layer, 17 ... Crack, 20 ... Auxiliary cathode wiring, 21 ... Deposition mask, 22 ... Mask projection, 23 ... Local thick film portion, 24 ... Partition wall scratch, 25 ... Pixel electrode as first electrode, 26B ... Blue light emitting functional layer, 26G ... Green light emitting functional layer, 26R ... Red light emitting functional layer, 26W ... White light emitting functional layer, 27 ... cathode as second electrode, 28 ... reflective layer, 29 ... organic EL element, 29R ... red organic EL element, 29G ... green organic EL element, 29B ... blue organic EL element, 31 ... semiconductor Layer ... 33 gate electrode, 35 ... source region, 36 ... drain region, 38 ... channel region, 48 ... light emission, 53 ... source electrode, 54 ... drain electrode, 70 ... gate insulating layer, 71 ... interlayer insulating layer, 72 ... Carrier layer, 73 ... first protective layer, 74 ... second protective layer, 77 ... partition, 78 ... adhesive layer, 79 ... convex, 80 ... color filter layer, 81B ... blue color filter, 81G ... green color Filter, 81R ... Red color filter, 82 ... Black matrix, 85 ... Passivation layer, 88 ... Circularly polarizing plate, 99 ... Outer peripheral part, 100 ... Display area, 102 ... Scanning line, 104 ... Signal line, 106 ... Power supply line, 108 DESCRIPTION OF SYMBOLS ... Switching TFT, 110 ... Holding capacitor, 112 ... Driving TFT, 120 ... Scanning line driving circuit, 130 ... Signal line driving circuit, 140 ... Synchronization signal line.

Claims (4)

On one surface of the substrate, a display area that is an area where an image is formed and an outer peripheral portion that surrounds the display area,
In the display area,
A light emitting functional layer including at least an EL material layer sandwiched between the first electrode and the second electrode, and emitting light from the EL material layer. An organic EL element that emits through the second electrode;
A partition wall separating the adjacent organic EL elements;
An auxiliary wiring electrically connected to the second electrode formed on the upper surface of the partition;
A passivation layer covering the partition and the organic EL element;
An organic EL device comprising:
An organic EL device, wherein a convex portion is formed on the upper surface of the partition wall.   2. The organic EL device according to claim 1, wherein the vertex of the convex portion has a curved surface shape.   3. The organic EL device according to claim 1, wherein the convex portion is formed of a material that can be deformed when a force is applied to the apex of the convex portion. 4. The organic EL device according to claim 1, wherein the partition wall is formed in an annular shape so as to surround the display area on the outer peripheral portion. 5.
The organic EL device according to claim 1, wherein the density of the convex portions is higher in the outer peripheral portion than in the display region.

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