JP2009110865A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device of which sealing performance is precisely judged and which has an excellent display quality and a long life. <P>SOLUTION: The display device has an active area composed of a plurality of pixels and is provided with an array substrate 100 which has an organic EL element 40 that is arranged in each pixel in the active area 102 and has an organic active layer between a pair of electrodes and a barrier rib 70 for separating each pixel, a sealing substrate 200 which is arranged opposed to on the organic EL element side of the array substrate, a seal member 300 which is arranged in a frame shape so as to surround the active area and pastes up the array substrate and the sealing substrate, and a self light-emitting test element TD which is arranged inside than the seal member at the outside of the active area. The test element TD has a structure which is easily deteriorated by moisture compared with the organic EL element 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a display device having a structure including a self-luminous display element.

  In recent years, organic electroluminescence (EL) display devices have attracted attention as flat display devices. Since this organic EL display device includes an organic EL element that is a self-luminous element, the viewing angle is wide, the backlight can be thinned, the power consumption can be reduced, and the response speed can be reduced. It has the feature of being fast.

  Because of these features, organic EL display devices are attracting attention as potential candidates for next-generation flat display devices that replace liquid crystal display devices. As an organic EL display device, a bottom emission method in which EL light generated in the organic EL element is extracted from the array substrate side and an EL light generated in the organic EL element is extracted from the sealing substrate side to the outside. There is a top emission method.

  The organic EL element of each pixel is provided on an array substrate together with a pixel circuit and the like, and is configured by holding an organic active layer containing an organic compound having a light emitting function between an anode and a cathode. Each pixel is separated by a partition formed of a resin material. The organic EL element having such a configuration is configured to include a thin film that easily deteriorates due to the influence of moisture. For this reason, in the case of a configuration in which an organic EL element is simply formed on a substrate, a non-lighting area called a dark spot or pixel shrinkage occurs in a short time, and such an area expands as a product. It becomes unusable.

Therefore, a substrate in which a moisture absorbing material for removing moisture in the organic EL display device is provided on the organic EL element is prepared, and a sealing substrate is provided via a seal member provided around the substrate on which the organic EL element is arranged. The structure which prevents deterioration by a water | moisture content by bonding together is proposed (for example, refer patent document 1).
JP 2002-299040 A

  As described above, since organic EL elements are inherently susceptible to deterioration by moisture, high levels of quality stability are required for the barrier properties of the sealing member and the hygroscopic capacity of the hygroscopic material. However, the resistance of the panel under high temperature and high humidity varies depending on the finished state of the sealing member, the amount of the hygroscopic material installed, and the variation in the hygroscopic capacity.

  The high-temperature and high-humidity storage test standards for panels equipped with organic EL elements are variously determined by the product specifications of the panel, but it is difficult to judge the quality of each panel, grasping the exact high-temperature and high-humidity resistance of each panel, It was difficult to perform an appropriate screening operation.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a display device having a structure capable of accurately determining whether the sealing performance is good in a short time.

A display device according to an aspect of the present invention includes:
A display device having an active area composed of a plurality of pixels,
In the active area, a first substrate having a self-luminous element having a structure in which an organic active layer is held between a pair of electrodes disposed in each pixel, and a partition that separates each pixel;
A second substrate disposed facing the self-luminous element side of the first substrate;
A sealing member disposed in a frame shape so as to surround the active area, and bonding the first substrate and the second substrate;
A self-luminous test element disposed inside the seal member outside the active area, and
The test element has a structure that is easily deteriorated by moisture as compared with the self-luminous element.

  According to the present invention, it is possible to provide a display device having a structure capable of accurately determining whether the sealing performance is good or not in a short time depending on the lighting state of the test element. At this time, with respect to the display device determined to be non-defective, it is possible to maintain a good display product for a long period of time and to improve reliability.

  A display device according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, a self-luminous display device such as an organic EL (electroluminescence) display device will be described as an example of the display device.

  As shown in FIG. 1, the organic EL display device 1 includes an array substrate 100 having an active area 102 for displaying an image. The active area 102 is composed of a plurality of pixels PX arranged in a matrix. Further, FIG. 1 shows a color display type organic EL display device 1 as an example, and the active area 102 includes a plurality of types of color pixels, for example, a red pixel PXR, a green pixel PXG, and a blue color corresponding to three primary colors. A pixel PXB is used.

  At least the active area 102 of the array substrate 100 is sealed with a sealing substrate 200. In other words, the array substrate 100 and the sealing substrate 200 are bonded together by the seal member 300 arranged in a frame shape so as to surround the active area 102. The seal member 300 may be a resin material (for example, an ultraviolet curable resin material) or a frit.

  Each pixel PX (R, G, B) includes a pixel circuit 10 and a display element 40 that is driven and controlled by the pixel circuit 10. The pixel circuit 10 shown in FIG. 1 is an example, and it goes without saying that a pixel circuit having another configuration may be applied. In the example shown in FIG. 1, the pixel circuit 10 includes a drive transistor DRT, a first switch SW1, a second switch SW2, a third switch SW3, a storage capacitor element CS, and the like. The drive transistor DRT has a function of controlling the amount of current supplied to the display element 40. The first switch SW1 and the second switch SW2 function as a sample / hold switch. The third switch element SW3 has a function of controlling driving current supply from the driving transistor DRT to the display element 40, that is, on / off of the display element 40. The storage capacitor element CS has a function of holding the potential between the gate and source of the drive transistor DRT.

  The drive transistor DRT is connected between the high potential power supply line P1 and the third switch SW3. The display element 40 is connected between the third switch SW3 and the low potential power line P2. The gate electrodes of the first switch SW1 and the second switch SW2 are connected to the first gate line GL1. The gate electrode of the third switch SW3 is connected to the second gate line GL2. The source electrode of the first switch SW1 is connected to the video signal line SL. The drive transistor DRT, the first switch SW1, the second switch SW2, and the third switch element SW3 are configured by, for example, thin film transistors, and the semiconductor layer is formed of polysilicon here.

  In the case of such a circuit configuration, the first switch SW1 and the second switch SW2 are turned on based on the ON signal supplied from the first gate line GL1, and the high potential is set according to the amount of current flowing through the video signal line SL. A current flows from the power supply line P1 to the drive transistor DRT, and the storage capacitor element CS is charged according to the current flowing through the drive transistor DRT. As a result, the drive transistor DRT can supply the same amount of current as that supplied from the video signal line SL to the display element 40 from the high potential power supply line P1.

  Then, the third switch SW3 is turned on based on the ON signal supplied from the second gate line GL2, and the driving transistor DRT is connected to the first potential from the high potential power supply line P1 according to the capacitance held in the storage capacitor element CS. A predetermined amount of current corresponding to a predetermined luminance is supplied to the display element 40 via the three switch SW3. Thereby, the display element 40 emits light with a predetermined luminance.

  The display element 40 includes an organic EL element 40 (R, G, B) that is a self-luminous display element. That is, the red pixel PXR includes an organic EL element 40R that mainly emits light corresponding to the red wavelength. The green pixel PXG includes an organic EL element 40G that mainly emits light corresponding to the green wavelength. The blue pixel PXB includes an organic EL element 40B that mainly emits light corresponding to the blue wavelength.

The various organic EL elements 40 (R, G, B) have basically the same configuration, and are disposed on the wiring substrate 120 as shown in FIG. The wiring board 120 includes an insulating layer such as an undercoat layer 111, a gate insulating film 112, an interlayer insulating film 113, and an organic insulating film 114 on an insulating support substrate 101 such as a glass substrate or a plastic sheet. , And various switches SW, driving transistors DRT, storage capacitor elements Cs, various wirings (gate lines, video signal lines, power supply lines, etc.), and the like. The undercoat layer 111, the gate insulating film 112, and the interlayer insulating film 113 are formed of an inorganic material having a lower water permeability than the resin material, such as a silicon oxide film (SiO ₂ ) or a silicon nitride film (SiN). Yes. Note that a passivation film formed of an inorganic material (such as a silicon oxide film or a silicon nitride film) may be disposed between the interlayer insulating film 113 and the organic insulating film 114 as necessary.

  That is, in the example shown in FIG. 2, the semiconductor layer 21 of the transistor element (the third switch SW3 in the circuit configuration shown in FIG. 1) 20 is disposed on the undercoat layer 111. ing. The semiconductor layer 21 is covered with the gate insulating film 112. On the gate insulating film 112, the gate electrode 20G of the transistor element 20 and the like are disposed. The gate electrode 20G is covered with an interlayer insulating film 113. On the interlayer insulating film 113, the source electrode 20S and the drain electrode 20D of the transistor element 20 are disposed. The source electrode 20S and the drain electrode 20D are in contact with the semiconductor layer 21 through contact holes that penetrate the gate insulating film 112 and the interlayer insulating film 113 to the semiconductor layer 21, respectively.

  The source electrode 20S and the drain electrode 20D are covered with an organic insulating film 114. Such an organic insulating film 114 is formed by a technique such as coating with a resin material in order to alleviate the influence of the unevenness of the lower layer and flatten the surface.

  The organic EL element 40 is disposed on the organic insulating film 114. The organic EL element 40 has a configuration in which an organic active layer 62 is held between a first electrode 60 and a second electrode 64, and a detailed structure will be described below.

  That is, the first electrode 60 is disposed on the organic insulating film 114 in an independent island shape for each color pixel PX, and functions as an anode. The first electrode 60 is in contact with the drain electrode 20D through a contact hole CH that penetrates the organic insulating film 114 to the drain electrode 20D. The first electrode 60 is formed of a light-transmitting conductive material such as indium tin oxide (ITO) and a light-reflective conductive material such as aluminum (Al). Further, it may be constituted by a laminated body in which a reflective layer is laminated, or may be constituted by a single transmission layer or a single reflection layer.

  The organic active layer 62 is disposed on the first electrode 60 and includes at least a light emitting layer. The organic active layer 62 can include functional layers other than the light emitting layer, and includes, for example, functional layers such as a hole injection layer, a hole transport layer, a blocking layer, an electron transport layer, an electron injection layer, and a buffer layer. it can. Such an organic active layer 62 may be composed of a single layer in which a plurality of functional layers are combined, or may have a multilayer structure in which the functional layers are laminated. In the organic active layer 62, the light emitting layer may be an organic material, and layers other than the light emitting layer may be an inorganic material or an organic material. In the organic active layer 62, the functional layer other than the light emitting layer may be a common layer. The light emitting layer is formed of an organic compound having a light emitting function that emits red, green, or blue light.

  The organic active layer 62 may include a thin film formed of a polymer material. Such a thin film can be formed by a selective coating method such as an inkjet method. The organic active layer 62 may include a thin film formed of a low molecular material. Such a thin film can be formed by a technique such as mask vapor deposition.

  The second electrode 64 is common to the plurality of color pixels PX, is disposed on the organic active layer 62 of each color pixel PX, and functions as a cathode. The second electrode 64 may include a semi-transmissive layer. That is, the second electrode 64 is disposed between a transmissive layer formed using a light-transmitting conductive material such as ITO, and between the transmissive layer and the organic active layer 62. Silver (Ag) and magnesium (Mg) It may be a two-layer structure with a semi-transparent layer formed of a mixture thereof or a semi-transparent layer electrode. Needless to say, the second electrode 64 may be formed of a single transmissive layer.

  In addition, the array substrate 100 includes a partition wall 70 that separates at least adjacent color pixels PX (R, G, B) in the active area 102. The partition wall 70 is disposed on the organic insulating film 114 so as to cover the periphery of each first electrode 60, and is formed in a lattice shape or a stripe shape in the active area 102. Such a partition wall 70 is formed by patterning a resin material. The partition wall 70 is covered with the second electrode 64.

  Further, when the seal member 300 is formed of a resin material, a desiccant is disposed in the sealed space between the array substrate 100 and the sealing substrate 200. Such a desiccant absorbs the water flowing into the sealed space through the seal member 300, and is disposed outside the active area 102 in the top emission type.

  In addition, when the sealing member 300 is formed of a frit, since the frit does not have water permeability, a desiccant is unnecessary, but a desiccant may be disposed in the sealed space.

  In this embodiment, the organic EL display device 1 includes a self-luminous test element TD that is disposed inside the seal member 300 (that is, inside the sealed space) in the region 104 outside the active area 102. Yes. The test element TD has a structure that is more easily deteriorated by moisture than the organic EL element 40 disposed in the active area 102.

  Similar to the organic EL element 40 in the active area 102, such a test element TD has a structure in which an organic active layer is held between a pair of electrodes. When the test element TD deteriorates due to moisture, a dark spot is generated, and the darker with time. The spot grows. For this reason, by knowing in advance the relationship (acceleration coefficient) that the dark spot is easily generated between the test element TD and the organic EL element 40 disposed in the active area 102, a short time is required for all the panels. By performing an endurance test in a high temperature and high humidity environment and observing the occurrence of dark spots on the test element TD, it is possible to determine whether or not the panel is acceptable. That is, it is possible to accurately determine the quality of the sealing performance in a short time. And about the panel determined as non-defective by such a screening, it becomes possible to maintain a favorable display quality over a long period of time, and it becomes possible to improve reliability.

  Further, the test element TD is arranged on the array substrate 100. The test element TD is at least partially made of the same material as the organic EL element 40. That is, the test element TD can be formed simultaneously with the organic EL element 40, and does not require a separate manufacturing process. That is, the test element TD can be arranged without increasing the cost.

  Below, the specific structural example of the test element TD which deteriorates more easily than the organic EL element 40 is demonstrated.

<< First Embodiment >>
In the first embodiment shown in FIG. 2, the organic EL element 40 disposed in the active area 102 includes a transmissive layer on a reflective layer (for example, aluminum) 60 </ b> R in which the first electrode 60 is disposed on the organic insulating film 114. (For example, ITO) 60T is a laminated body, and the second electrode 64 is disposed on a semi-transmissive layer (for example, a mixture of magnesium and silver) 64H disposed on the organic active layer 62. It is comprised as a laminated body which laminated | stacked 64T.

  In the first embodiment, the organic EL display device 1 further includes a protective film 80 that covers the second electrode 64. Such a protective film 80 is disposed over the entire active area 102 and further extends to the outside (that is, the end portion side of the array substrate 100) from the outermost peripheral partition wall 70X. The protective film 80 is made of an inorganic material such as silicon nitride or silicon oxide. That is, the partition wall 70 surrounding the organic EL element 40 is covered with a thin film made of an inorganic material, such as the second electrode 64 and the protective film 80.

  As shown in FIGS. 2 and 3, the test element TD disposed in the region 104 outside the active area is surrounded by the bank B formed of a resin material, and is configured substantially in the same manner as the organic EL element 40. ing.

  Note that the pixel circuit as shown in FIG. 1 is not connected to the test element TD so that the lighting check can be easily performed. That is, the test element TD is held between the lower electrode E1 disposed on the organic insulating film 114, the upper electrode E2 disposed on the sealing substrate 200 side, and the lower electrode E1 and the upper electrode E2. The organic active layer ELL thus formed.

  Further, it is desirable that the bank B is formed of the same resin material as the partition wall 70 because it does not increase the number of processes.

  Similar to the first electrode 60, the lower electrode E1 is configured as a laminate in which a reflective layer (eg, aluminum) E1R disposed on the organic insulating film 114 is laminated with a transmissive layer (eg, ITO) E1T. . At least one of the conductive layers constituting the lower electrode E1 extends outward from the seal member 300 and is drawn to the substrate end 100E1 to constitute a terminal T1 that can apply a voltage. In the example shown in FIGS. 2 and 3, the transmissive layer E1T is drawn out to the substrate end 100E1 to constitute the terminal T1.

  The organic active layer ELL is configured in the same manner as the organic active layer 62.

  Similar to the second electrode 64, the upper electrode E2 is a laminate in which a transmissive layer (for example, ITO) E2T is laminated on a semi-transmissive layer (for example, a mixture of magnesium and silver) E2H disposed on the organic active layer ELL. It is configured as. At least one of the conductive layers constituting the upper electrode E2 extends outward from the seal member 300 and is drawn to the substrate end 100E2 so as not to short-circuit with the lower electrode E1 so that a voltage can be applied. Terminal T2 is configured. In the example shown in FIGS. 2 and 3, the transmissive layer E2T is drawn out to the substrate end 100E2 to constitute the terminal T2.

  In the test element TD, the structures of the lower electrode E1 and the upper electrode E2 are not necessarily the same as those of the first electrode 60 and the second electrode 64 of the organic EL element 40. In the test element TD, the structure is simpler. The structure, that is, the lower electrode E1 and the upper electrode E2 may each be configured as a single layer.

  With such a configuration, the test element TD can be turned on by applying a DC voltage between the terminal T1 and the terminal T2.

  The bank B is exposed in the sealed space without covering at least a part of its surface. That is, the test element TD and the bank B are not covered with the protective film 80. Further, the upper electrode E2 is formed in a necessary minimum area except for the portion constituting the terminal T2, and is interrupted on the upper surface BT of the bank B. That is, a part of the upper surface BT of the bank B and a part of the outer surface BE of the bank B are exposed from the protective film 80 and the upper electrode E2, and are exposed to the sealed space.

  The first embodiment having such a configuration is based on the fact that the progress of moisture is faster in the resin material than in the organic EL element 40 itself. That is, when a pinhole is generated in the second electrode 64 or the protective film 80 of the organic EL element 40 due to a foreign substance or the like, moisture enters from the vicinity of the pinhole and a dark spot is generated. The case where the pinhole on the partition wall 70 formed of the material is used as the base point is much larger than the case where the pinhole on the organic EL element 40 is used as the base point (for example, about 5 to 10 times).

  Based on such knowledge, in the active area 102, the partition wall 70 surrounding the organic EL element 40 is covered with a thin film made of an inorganic material such as the second electrode 64 and the protective film 80, and the partition wall 70 is originally exposed. (If a pinhole is generated in the second electrode 64 and the protective film 80, only a small region is exposed), whereas in the region 104 outside the active area, the resin material surrounding the test element TD Most of the area of the bank B is exposed without being covered with a thin film made of an inorganic material. Accordingly, the test element TD can be configured to be easily deteriorated by moisture as compared with the organic EL element 40 (that is, a configuration in which dark spots are easily generated).

<< Second Embodiment >>
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment shown in FIGS. 4 and 5, the test element TD has a configuration in which the organic active layer ELL is held between the lower electrode E1 and the upper electrode E2, and is disposed on the sealing substrate side. The electrode, that is, the upper electrode E2 is formed so as to expose a part of the organic active layer ELL. That is, a hole H penetrating to the organic active layer ELL is formed in the upper electrode E2.

  In the configuration in which the protective film 80 is further disposed on the second electrode 64 in the active area 102, the protective film 80 is not disposed on the upper electrode E2, or the protective film 80 is also a part of the organic active layer ELL. To be exposed. That is, in the test element TD, the organic active layer ELL is exposed to the sealed space. The area where the organic active layer ELL is exposed is usually set larger than the size of the pinhole that can be formed.

  According to the second embodiment, in the active area 102, the organic active layer 62 constituting the organic EL element 40 is covered with a thin film made of an inorganic material such as the second electrode 64 or the protective film 80. In the region 104 outside the active area, the test element TD is not exposed in nature (if a pinhole is generated in the second electrode 64 and the protective film 80, a small region is exposed). A part of the organic active layer ELL constituting the layer is exposed without being covered with a thin film made of an inorganic material. Accordingly, the test element TD can be configured to be easily deteriorated by moisture as compared with the organic EL element 40 (that is, a configuration in which dark spots are easily generated).

  In the second embodiment, the bank B surrounding the test element TD may not be covered with an inorganic material as in the first embodiment, as in the example shown in FIG. Similarly to 70, it may be covered with a thin film made of an inorganic material such as the upper electrode E <b> 2 or the protective film 80.

<< Third Embodiment >>
In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the third embodiment, the test element TD has a configuration in which the organic active layer ELL is held between the lower electrode E1 and the upper electrode E2, and is an inorganic material disposed closer to the sealing substrate than the organic active layer ELL. The number of thin film layers made of is configured to be smaller than the number of thin film layers made of an inorganic material disposed closer to the sealing substrate than the organic active layer 62 in the organic EL element 40.

  More specifically, as shown in FIG. 6, one electrode disposed on the sealing substrate side in the organic EL element 40, that is, the second electrode 64, is a stacked body configured by stacking a plurality of conductive layers. It is. That is, the second electrode 64 has a structure in which two conductive layers of a semi-transmissive layer 64H and a transmissive layer 64T made of an inorganic material are stacked.

  On the other hand, one electrode arranged on the sealing substrate side in the test element TD, that is, the upper electrode E <b> 2 is configured by a conductive layer having a smaller number of layers than the second electrode 64 of the organic EL element 40. That is, the upper electrode E2 has a single-layer structure, and is composed of, for example, only a transmission layer (for example, ITO) E2T made of an inorganic material.

  In the configuration in which the protective film 80 is further disposed on the second electrode 64 in the active area 102, it is possible to configure a test element TD that is more likely to deteriorate if the protective film 80 is not disposed on the upper electrode E2. However, even if the protective film 80 is disposed on the upper electrode E2, the second electrode 64 has two or more layers, whereas the upper electrode E2 has a smaller number of layers than the second electrode 64. If so, it is possible to configure a test element TD that is likely to deteriorate.

  According to the third embodiment, the organic active layer 62 constituting the organic EL element 40 in the active area 102 is formed by a thin film made of an inorganic material such as the second electrode 64 and the protective film 80 having a two-layer structure. The organic active layer ELL constituting the test element TD in the region 104 outside the active area is thinner than the organic active layer 62 while being covered and difficult to form a moisture intrusion path. It will be covered by the material. Accordingly, the test element TD can be configured to be easily deteriorated by moisture as compared with the organic EL element 40 (that is, a configuration in which dark spots are easily generated).

  In the third embodiment, the bank B surrounding the test element TD may not be covered with an inorganic material as in the first embodiment, as in the example shown in FIG. Similarly to 70, it may be covered with a thin film made of an inorganic material such as the upper electrode E <b> 2 or the protective film 80.

<Verification of effect>
Next, the effect of the organic EL display device according to this embodiment was verified.

  First, one glass substrate (supporting substrate) having a dimension (400 mm × 500 mm) capable of forming 24 array substrates in which the diagonal dimension of the active area 102 is 3.5 type (sample A) was prepared.

  The sample A includes a pixel circuit 10 for each pixel corresponding to the active area, and is configured as a wiring substrate covered with an organic insulating film 114. The first electrode 60 includes a reflective layer (aluminum) 60R disposed on the organic insulating film 114 and a transmissive layer (ITO) 60T stacked on the reflective layer 60R, and a contact formed on the organic insulating film 114. The transistor element 20 is electrically connected through a hole. Note that transistor elements such as switches and drive transistors that constitute the pixel circuit 10 are configured to include a polysilicon thin film as a semiconductor layer.

  The partition wall 70 is formed in a lattice shape over the entire active area 102 so as to surround the first electrode 60 on the organic insulating film 114. The lattice pattern pitch in the partition wall 70 is 73 μm × 219 μm, and the inside of the partition wall 70 is a region contributing to the display of the organic EL element 40 (the first electrode 60 exposed from the partition wall 70), and the dimension is 40 μm × 140 μm. Met.

  On the other hand, in the region 104 outside the active area, the lower electrode E1 is formed on the organic insulating film 114 in order to arrange the test element TD at the corner. The lower electrode E1 includes a reflective layer (aluminum) E1R and a transmissive layer (ITO) E1T stacked on the reflective layer E1R. The bank B is formed in a circular shape on the organic insulating film 114 so as to surround the lower electrode E1. The bank B is formed of the same resin material as the partition wall 70.

  Note that no pixel circuit is arranged below the test element TD so that the lighting check can be easily performed. The transmissive layer E1T is drawn to the end of the substrate and constitutes a terminal T1. The size D1 of the test element TD is 500 μmΦ including the bank, and the size D2 of the region contributing to the display of the test element TD (the lower electrode E1 exposed from the bank B) is 300 μmΦ.

For sample A described above, the substrate was set in a resistance heating type organic EL film forming apparatus, and α-NPD functioning as a hole transport layer was formed as the organic active layer 62 to a film thickness of 200 nm, and then the light emitting layer forming a Alq ₃ which serves as a cum electron transport layer to a thickness of 50 nm, further, an electron injection layer and the damage buffer layer (semi-transparent layer) as the magnesium (Mg) and silver (Ag) formed to a film thickness of 2nm Filmed. Further, an ITO film having a thickness of 100 nm was formed as a transmission layer using a plasma coating method. That is, in the organic EL element 40, the second electrode 64 has a two-layer structure of the semi-transmissive layer 64H and the transmissive layer 60T.

  For the test element TD, the organic active layer ELL has the same configuration as that of the organic active layer 62 of the organic EL element 40, and the upper electrode E2 is substantially composed of only the semi-transmissive layers (Mg and Ag) E2H. did. The upper electrode E2 is formed so as to cover the organic active layer ELL and a part of the upper surface BT of the bank B, and most of the surface of the bank B is exposed. The ITO forming the transmissive layer contacts a part of the semi-transmissive layer E2H and is drawn out to the end of the substrate to constitute the terminal T2.

  The active area 102 of sample A was sealed by the sealing substrate 200 together with the test element TD. That is, an ultraviolet curable resin material as a sealing member is applied in a frame shape on the sealing substrate 200 using a dispenser, and then bonded to the substrate of the sample A, and the resin material is cured by ultraviolet irradiation under predetermined conditions. It was. Thereby, an organic EL element is arrange | positioned in sealed space.

  In Sample A, the seal member has a standard line width of 1.0 mm and a height of 10 μm (Aa-1), and a standard line width of 2.0 mm and a height of 10 μm. (Aa-2) and 12 patterns were created for each.

  After cleaving the substrate pair of sample A, peripheral circuits were mounted to produce 24 organic EL display devices for sample A. In this verification, in order to confirm a remarkable effect in a short time with respect to Sample A, a normally required desiccant was not installed in the sealed closed space.

  Next, these 2 × 12 organic EL display devices are left in a high-temperature and high-humidity environment (85 ° C. × 85% RH), and after a predetermined time, the organic EL elements 40 in the active area and the active area Display confirmation was performed for each of the external test elements TD, and the occurrence of deterioration due to moisture such as dark spots was visually observed.

  Since no pixel circuit is arranged for the test element TD, a DC voltage is applied to the terminals T1 and T2 drawn out of the seal from the lower electrode E1 and the upper electrode E2, respectively, so that the test element TD is lit and observed. Went.

  In this verification, regarding the presence or absence of the occurrence of dark spots, it was determined that the dark spots were generated when the organic EL element 40 was confirmed to have a dark spot having a visible size of, for example, 90 μm. For the test element TD, it was determined that a dark spot was generated when the size D2 of the lighting region decreased from the initial 300 μmΦ to, for example, 200 μmΦ, or when a dark spot of 90 μm was confirmed in the lighting region. .

  The results are shown in FIGS. FIG. 7 shows the result of the dark spot generation state of the test element, and FIG. 8 shows the result of the dark spot generation state of the organic EL element.

  From the results shown in FIG. 7 and FIG. 8, the dark spot generation timing in the test element TD is so early that there is a panel whose exact generation time is unknown, but the dark spot generation time of the test element TD is the organic EL element It can be seen that the dark spot generation time of 40 is almost 1/5 or less.

  From this, it can be confirmed that the acceleration coefficient of the dark spot generation time of the test element TD is 5 times or more that of the organic EL element 40. For example, in a high temperature and high humidity (85 ° C./85% RH) environment as a product specification If it is necessary that dark spots do not occur after standing for 500 hours, the test element TD is observed after leaving for 150 hours in the same high-temperature and high-humidity environment. Satisfies and can be judged as a good product.

  On the other hand, if dark spots are generated, it is predicted that dark spots will occur in a total of about 750 hours. In other words, since 150 hours have already passed, dark spots are generated after being left in a high-temperature and high-humidity environment for the remaining 600 hours. Therefore, it is appropriate to determine a defect including a margin.

  In this verification design, the acceleration coefficient is five times, but it is possible to further increase the acceleration coefficient by devising the pixel design or by magnifying the test element using a microscope. Thereby, the time required for screening can be shortened.

  Further, in this verification, the test element TD is installed outside the corner portion outside the active area. However, any part of the test element TD is essentially in the sealed space surrounded by the array substrate, the sealing substrate, and the sealing member. The installation location may be determined according to the circumstances of the panel design.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the spirit of the invention in the stage of implementation. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  For example, in each of the first to third embodiments described above, the organic active layer ELL in the test element TD has the same configuration as that of the organic active layer 62. However, the test element TD is more easily deteriorated than the organic EL element 40. In addition, it is also effective to use a material that easily deteriorates due to moisture in at least a part of the organic active layer ELL, or to use a material that easily corrodes due to moisture as the electron injection layer.

  Further, in the first to third embodiments as described above, the partition wall 70 and the bank B are formed of the same material because of the advantage that the test element TD surrounded by the bank B can be formed simultaneously in the process of forming the active area. However, the present invention is not limited to this. That is, in configuring the test element TD that is more easily deteriorated than the organic EL element 40, the bank B may be formed of a resin material having higher hygroscopicity than the partition wall 70.

  Further, as shown in FIG. 2 and the like, in the test element TD, the upper electrode E2 does not cover the end face of the organic active layer ELL, that is, the end face of the organic active layer ELL and the end face of the upper electrode E2 are in a pitch. The organic active layer ELL is exposed to the sealed space and is effective in configuring the test element TD that is more easily deteriorated than the organic EL element 40.

  Further, a plurality of test elements TD may be arranged in the sealed space.

FIG. 1 is a diagram schematically showing a configuration of an organic EL display device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the structure of the active area and the region outside the active area when the organic EL display device according to the first embodiment is cut. FIG. 3 is a plan view schematically showing the structure of the test element outside the active area shown in FIG. FIG. 4 is a cross-sectional view schematically showing the structure of an active area and a region outside the active area when the organic EL display device according to the second embodiment is cut. FIG. 5 is a plan view schematically showing the structure of the test element outside the active area shown in FIG. FIG. 6 is a cross-sectional view schematically showing the structure of an active area and a region outside the active area when the organic EL display device according to the third embodiment is cut. FIG. 7 is a diagram showing a result of verifying the effect obtained by providing the test element, and is a diagram showing a dark spot generation state of the test element. FIG. 8 is a diagram showing a verification result of the effect obtained by providing the test element, and is a diagram showing a dark spot generation state of the organic EL element in the active area.

Explanation of symbols

PX ... pixel PXR ... red pixel PXG ... green pixel PXB ... blue pixel DRT ... drive transistor CS ... storage capacitor element SW ... switch P1 ... high potential power line P2 ... low potential power line SL ... video signal line TD ... test element B ... Bank BT ... Upper surface BE ... Outer surface E1 ... Lower electrode E1R ... Reflective layer E1T ... Transmission layer T1 ... Terminal E2 ... Upper electrode E2H ... Transflective layer E2T ... Transmission layer T2 ... Terminal EL ... Organic active layer 1 ... Organic EL display device DESCRIPTION OF SYMBOLS 10 ... Pixel circuit 20 ... Transistor element 40 ... Display element (organic EL element)
DESCRIPTION OF SYMBOLS 60 ... 1st electrode 60R ... Reflective layer 60T ... Transmission layer 62 ... Organic active layer 64 ... 2nd electrode 64H ... Semi-transmission layer 64T ... Transmission layer 70 ... Partition 80 ... Protective film 100 ... Array substrate 102 ... Active area 104 ... Active Area outside area 120 ... Wiring board 200 ... Sealing board 300 ... Sealing member

Claims (9)

A display device having an active area composed of a plurality of pixels,
In the active area, a first substrate having a self-luminous element having a structure in which an organic active layer is held between a pair of electrodes disposed in each pixel, and a partition that separates each pixel;
A second substrate disposed facing the self-luminous element side of the first substrate;
A sealing member disposed in a frame shape so as to surround the active area, and bonding the first substrate and the second substrate;
A self-luminous test element disposed inside the seal member outside the active area, and
The display device according to claim 1, wherein the test element has a structure that is more easily deteriorated by moisture than the self-light-emitting element.   The display device according to claim 1, wherein the test element is disposed on the first substrate, and at least a part of the test element is formed of the same material as the self-luminous element. The test element is surrounded by a bank formed of a resin material,
The partition wall is covered with a thin film made of an inorganic material on the surface,
The display device according to claim 1, wherein at least a part of a surface of the bank is exposed without being covered.   The display device according to claim 3, wherein the partition and the bank are formed of the same material.   The display device according to claim 3, wherein the bank is formed of a resin material having higher hygroscopicity than the partition wall. The test element has a structure in which an organic active layer is held between a pair of electrodes,
The display device according to claim 1, wherein in the test element, one electrode disposed on the sealing substrate side is formed so as to expose a part of the organic active layer. The test element has a structure in which an organic active layer is held between a pair of electrodes,
The number of layers of the thin film made of an inorganic material disposed on the sealing substrate side from the organic active layer in the test element is an inorganic system disposed on the sealing substrate side from the organic active layer in the self-luminous element. The display device according to claim 1, wherein the number of layers of the thin film made of the material is smaller. One electrode arranged on the sealing substrate side in the self-luminous element is configured by laminating a plurality of conductive layers,
The display device according to claim 7, wherein one electrode arranged on the sealing substrate side in the test element is configured by a conductive layer having a smaller number of layers than the self-light-emitting element.   2. The display device according to claim 1, wherein the seal member is a frit.

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