Electroluminescent display device

Abstract

Electroluminescent display device comprising the following: a substrate (100); a bank (400) configured to define an emission range (E); an emission layer (500) located in the emission area (E) defined by the bank (400); an electrode (600) arranged on the emission layer (500) and on the bank (400); and a conductive layer (700) arranged on a section of the electrode (600) which is arranged on the bench (400), wherein the substrate (100) contains an active region (AA) and a dummy region (DA) at a circumferential edge of the active region (AA), characterized in that the conductive layer (700) in the active area (AA) is arranged exclusively on the bank (400) and in the dummy area (DA) is arranged on the bank (400) and on the emission layer (500).

Description

BACKGROUND Technical area

[0001] The present disclosure relates to an electroluminescent display device, and in particular to an electrode of an electroluminescent display device. Description of the state of the art

[0002] An electroluminescent display device is provided in which an emission layer is formed between two electrodes. When the emission layer emits light through an electric field between the two electrodes, an image is displayed on the electroluminescent display device.

[0003] The emission layer can be formed from an organic material that emits light when an exciton is generated by a bond between an electron and a hole and the exciton falls from an excited state to a ground state, or it can be formed from an inorganic material, such as a quantum dot.

[0004] In the following, an electroluminescent display device of the prior art is described with reference to the accompanying drawings.

[0005] Fig. Figure 1 is a cross-sectional view illustrating a prior art electroluminescent display device.

[0006] As in Fig. As shown in Figure 1, the electroluminescent display device of the prior art can include a substrate 10, a circuit device layer 20, a first electrode 30, a bank 40, an emission layer 50 and a second substrate 60.

[0007] The circuit device layer 20 is formed on the first substrate 10. The circuit device layer 20 contains various signal lines, a thin-film transistor, and a capacitor.

[0008] The first electrode 30 is formed on the circuit device layer 20. The first electrode 30 is structured by each pixel, with the first electrode 30 acting as an anode of the electroluminescent display device.

[0009] Bank 40 is formed in a matrix configuration, which is defined as an emission area.

[0010] Emission layer 50 is formed in the emission range defined by bank 40.

[0011] The second electrode 60 is formed on the emission layer 50, with the second electrode 60 functioning as a cathode of the electroluminescent display device. The second electrode 60 is formed on the bank layer 40 as well as the emission layer 50.

[0012] In the case of the electroluminescent display device of the prior art, a first section 60a of the second electrode 60, which is formed on a side surface of the bank 40, is relatively thinner than a second section 60b of the second electrode 60, which is formed on a top surface of the bank 40, and a third section 60c of the second electrode 60, which is formed on a top surface of the emission layer 50.

[0013] In this case, the resistance of the first section 60a of the second electrode 60, formed on the side surface of the bank 40, is increased, which can lead to a burning phenomenon in the first section 60a of the second electrode 60, i.e., a connection can be severed. In particular, if the emission layer 50 is formed by an inkjet process, the burning phenomenon or the separation of the connection can become a major problem. That is, if the emission layer 50 is formed by an inkjet process, a large lateral angle (θ) of the bank 40 is advantageous insofar as it can prevent the emission layer 50, formed in one emission region, from penetrating into another emission region. However, if the lateral angle (θ) of the bank 40 becomes large, the first section 60a of the second electrode 60, formed on the side surface of the bank 40, becomes thinner.Thus, the aforementioned problem in connection with the combustion phenomenon and the disconnection of the wiring in the first section 60a takes on considerable dimensions.

[0014] US 2008 / 0100209 A1 discloses an organic electroluminescent device comprising a plurality of pixel electrodes arranged on one side of a substrate, and a plurality of organic electroluminescent layers with a multi-layer structure, each arranged on the plurality of pixel electrodes. A translucent opposing electrode is arranged above the organic electroluminescent layer, and a bank is arranged between each of the organic electroluminescent layers and comprises a strip-shaped auxiliary electrode.

[0015] US 2009 / 0096371 A1 comprises an organic electroluminescent device in which an upper electrode is mounted on a transparent conductive film. Pixels are arranged between an upper electrode and a lower electrode in a matrix configuration, forming a display area. SUMMARY

[0016] The present disclosure is based on the recognition of the problems described above, and it is an object of the present disclosure to provide an electroluminescent display device that is able to avoid problems associated with a burning phenomenon or a disconnection of the wiring in a section of an electrode formed on a side face of a bank, even if the bank has a large lateral angle.

[0017] The problems are solved by the features of the independent claims. Features of preferred embodiments are set forth in the dependent claims. According to one aspect of the present disclosure, an electroluminescent display device comprises a substrate, a first electrode arranged on the substrate, a bank configured to cover one end of the first electrode and define an emission region, an emission layer arranged on the first electrode in the emission region defined by the bank, a second electrode arranged on the emission layer and the bank, and a conductive layer arranged on the second electrode while in contact with the second electrode, wherein the second electrode comprises a first section arranged on a side face of the bank, a second section arranged on a top face of the bank,and includes a third section located on a top side of the emission layer, and wherein the conductive layer includes a first section located on the first section of the second electrode.

[0018] According to another aspect of the present disclosure, an electroluminescent display device is provided comprising: a substrate containing an active region and a dummy region formed in the circumferential edge of the active region, a bank arranged on the active region and the dummy region of the substrate and configured to define an emission region, an emission layer arranged in the emission region defined by the bank, an electrode arranged on the bank and the emission layer, and a conductive layer arranged on the electrode while in contact with the electrode, wherein a structure of the conductive layer in the active region is different from a structure of the conductive layer in the dummy region.

[0019] According to another aspect of the present disclosure, an electroluminescent display device is provided comprising: a substrate, a bank configured to define an emission region on the substrate, an emission layer arranged in the emission region defined by the bank, an electrode arranged on the emission layer and the bank, and a conductive layer arranged on the electrode, wherein the electrode includes a first section having a relatively small thickness and a second section having a relatively large thickness, and the conductive layer is in contact with the first section of the electrode. BRIEF DESCRIPTION OF THE DIFFERENT VIEWS OF THE DRAWINGS

[0020] The tasks, features, and other advantages of this disclosure, as described above, will be better understood with reference to the following detailed description, which should be read in conjunction with the accompanying drawings. The drawings show the following: Fig. Figure 1 is a cross-sectional view illustrating a prior art electroluminescent display device; Fig. Figure 2 is a top view illustrating an electroluminescent display device according to an embodiment of the present disclosure; Fig. Figure 3A is a cross-sectional view illustrating the electroluminescent display device according to an embodiment of the present disclosure, and Fig. 3B is a top view illustrating several pixels in the electroluminescent display device according to an embodiment of the present disclosure; Fig. Figure 4 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure; Fig. Figure 5 is a cross-sectional view illustrating an electroluminescent display device according to an embodiment that does not represent the invention; Fig. Figure 6 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure; and Fig. Figure 7 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure. DETAILED DESCRIPTION OF THE REVELATION

[0021] The advantages and features of the present disclosure, as well as methods for its implementation, are explained by the following embodiments, which are described with reference to the accompanying drawings. However, the present disclosure can be embodied in various forms and should not be interpreted as limiting the embodiments set forth herein. Rather, these embodiments are designed to ensure that this disclosure is thorough and complete and fully conveys the concept of the present disclosure to the person skilled in the art. Furthermore, the present disclosure is defined solely by the scope of protection of the claims.

[0022] The shapes, sizes, ratios, angles, and numbers disclosed in the drawings to describe embodiments of the present disclosure are merely examples, and therefore the present disclosure is not limited to the illustrated details. Identical reference numerals always refer to the same elements. If, in the following description, it is determined that a detailed description of a relevant known function or configuration would unnecessarily overshadow the important aspects of the present disclosure, the detailed description will be omitted.

[0023] In cases where the terms "comprise," "have," and "contain" are used in this specification, another part may also be present unless "only" is indicated. Singular terms may also include the plural form unless otherwise noted.

[0024] When understanding an element, the element should be understood as containing an error region, even if there is no explicit description of it.

[0025] When describing a positional relationship, for example, if the positional sequence is described as "on," "above," "below," and "next to," this can also include the case of a lack of contact between the elements, unless "immediately" or "directly" is used. If it is mentioned that a first element is positioned "on" a second element, this does not mean that the first element is essentially positioned above the second element in the figure. The upper and lower parts of an object in question can be interchanged depending on the object's orientation. Consequently, the case in which—in the figure or in an actual configuration—a first element is positioned "on" a second element also includes the case in which the first element is positioned "below" the second element, as well as the case in which the first element is positioned "above" the second element.

[0026] When describing a temporal relationship, for example, if the temporal sequence is described as "after", "subsequently", "next" and "before", there may also be a case that is not continuous, unless "immediately" or "directly" is used.

[0027] It is understood that, although the terms "first," "second," etc., may be used in the present text to describe different elements, these elements must not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be called a second element, and likewise a second element could be called a first element, without altering the scope of protection afforded by this disclosure.

[0028] The terms “first horizontal axis direction”, “second horizontal axis direction” and “vertical axis direction” should not be interpreted solely on the basis of a geometric relationship in which the respective directions are perpendicular to each other, and may be meant as directions that exhibit a wider diversity within the range in which the components of the present disclosure can function.

[0029] It is understood that the phrase "at least one" includes all combinations related to a single element. For example, "at least one of a first element, a second element, and a third element" can include all combinations of two or more elements selected from the first, second, and third elements, as well as each element of the first, second, and third elements.

[0030] Features of different embodiments of the present disclosure can be partially or completely coupled or combined with one another and can be operated and technically controlled in various ways, as a person skilled in the art can reasonably understand. The embodiments of the present disclosure can be implemented independently of one another or can be implemented together in a mutually dependent relationship.

[0031] In the following, an electroluminescent display device according to the embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0032] Fig. Figure 2 is a top view illustrating an electroluminescent display device according to an embodiment of the present disclosure.

[0033] As in Fig. As shown in Figure 2, the electroluminescent display device according to an embodiment of the present disclosure can include an active area (Active Area AA), a dummy area (Dummy Area DA) and a pad area (Pad Area PA).

[0034] The active area (AA) serves as a display area for showing an image. Several pixels are arranged within the active area (AA).

[0035] More precisely, signal lines, such as a gate line, a data line, a power line, and a reference line, are arranged in the active area (AA) pixel. Furthermore, several thin-film transistors for switching the transmission of a signal applied through the signal line are arranged in the active area (AA) pixel, and an emission device, which is driven by the thin-film transistors to emit light, is also located in the active area (AA) pixel.

[0036] The dummy area (DA) is designed to surround the active area (AA).

[0037] More precisely, the dummy area (DA) is formed along the left, right, bottom, and top perimeter edges of the active area (AA). Several pixels are arranged in the dummy area (DA) in the same way as in the active area (AA). However, the dummy area (DA) is not the display area for showing an image, so the structure of the pixel located in the dummy area (DA) differs from the structure of the pixel located in the active area (AA). For example, at least one of the signal line, thin-film transistor, and emission device is either not present or only partially present in the pixel of the dummy area (DA), so no light is emitted by the pixel located in the dummy area (DA).

[0038] The dummy area (DA) prevents a production error between a central section of the active area (AA) and a peripheral section of the active area (AA). This is described in detail below.

[0039] Multiple deposition and masking processes can be performed to create the multiple pixels in the active area (AA). The deposition process can be performed to create an insulating layer, a metal layer, or an organic layer using a physical deposition process, a chemical deposition process, a coating process, or an inkjet process. The masking process can be performed to create a predefined structure, exhibiting a predefined shape, within the insulating layer, metal layer, or organic layer created by the deposition process, using a photolithography process.

[0040] If the multiple deposition and masking processes are executed for the active area (AA), the production defect could occur between the central section of the active area (AA) and the peripheral section of the active area (AA). Accordingly, since the dummy area (DA) is located at the peripheral edge of the active area (AA), the production defect may be generated in the dummy area (DA) instead of in the active area (AA).

[0041] In particular, if an emission layer is formed inside the emission device using an inkjet process, the dryness of the emission layer in the central section of the substrate may differ from that in the peripheral section. In this case, if the dummy area (DA) is not present, a problem related to uneven light emission between the central and peripheral sections of the active area (AA) may occur.

[0042] Accordingly, the dummy area (DA) is positioned at the periphery of the active area (AA). If the emission layer in the emission device is formed by the inkjet process, the dryness of the emission layer between the active area (AA) and the dummy area (DA) may not be uniform. Even in this case, the dryness of the emission layer within the active area (AA) can be perfectly uniform thanks to the dummy area (DA) positioned at the periphery of the active area (AA).

[0043] The contact island area (PA) is located in the perimeter of the dummy area (DA).

[0044] A circuit driver, such as a gate driver or a data driver, can be implemented in the contact island area (PA). The circuit driver can be located on the circumferential edge of at least one of the left, right, bottom, and top surfaces of the dummy area (DA). The circuit driver implemented in the contact island area (PA) is connected to the circuit device inside the active area (AA) via the dummy area (DA).

[0045] Fig. Figure 3A is a cross-sectional view illustrating the electroluminescent display device according to an embodiment of the present disclosure, and Fig. Figure 3B is a top view illustrating the multiple pixels in the electroluminescent display device according to an embodiment of the present disclosure, which includes the above-mentioned active area (AA) of the Fig. 2 show the electroluminescent display device.

[0046] As in Fig. As shown in Figure 3A, the electroluminescent display device according to an embodiment of the present disclosure can include a substrate 100, a circuit device layer 200, a first electrode 300, a bank 400, an emission layer 500, a second electrode 600 and a conductive layer 700.

[0047] The first substrate 100 can be made from a glass or plastic material, but is not limited to this material. The first substrate 100 can be made from a transparent or an opaque material.

[0048] If the electroluminescent display device according to an embodiment of the present disclosure is of an upward-emitting type, in which the light emitted by the emission layer 500 shines towards a top surface, the first substrate 100 can be formed from either the opaque or the transparent material. However, if the electroluminescent display device according to an embodiment of the present disclosure is of a downward-emitting type, in which the light emitted by the emission layer 500 shines towards a bottom surface, the first substrate 100 need only be formed from the transparent material.

[0049] The circuit device layer 200 is formed on the substrate 100.

[0050] In the circuit device layer 200, a circuit device containing various signal lines, a thin-film transistor, and a capacitor is arranged for each pixel. The signal lines can include a gate line, a data line, a power line, and a reference line, and the thin-film transistor can include a switching thin-film transistor, a drive thin-film transistor, and a read thin-film transistor.

[0051] When the switching thin-film transistor is switched according to a gate signal fed into the gate line, a data voltage supplied from the data line is fed into the control thin-film transistor by means of a switching thin-film transistor.

[0052] When the control thin-film transistor is switched according to the data voltage supplied by the switching thin-film transistor, a data current is generated by current supplied from the power line, and the generated data current is supplied to the first electrode 300.

[0053] The read thin-film transistor detects a threshold voltage deviation of the drive thin-film transistor, which causes a degradation of image quality. In response to a read control signal supplied by the gate line or an additional read line, the read thin-film transistor injects a current from the drive thin-film transistor into the reference line.

[0054] The capacitor maintains the data voltage supplied to the driver thin-film transistor for a single frame period. The capacitor is connected to each of the gate and source terminals of the driver thin-film transistor.

[0055] The first electrode 300 is formed on the circuit device layer 200. The circuit device layer comprises a thin-film transistor.

[0056] The first electrode 300 is structured by each pixel and acts as an anode of the electroluminescent display device. If the electroluminescent display device, according to one embodiment of the present disclosure, is applied to an upward-emitting type, the first electrode 300 may contain a reflective material for reflecting upwards the light emitted by the emission layer 500. In this case, the first electrode 300 may be formed in a deposition structure containing the reflective material and a transparent conductive material. If applied to a downward-emitting type, the first electrode 300 may be formed from the transparent conductive material.

[0057] The 400 bank is formed along the boundary between adjacent pixels. That is, the 400 bank is formed in a matrix configuration to define an emission area.

[0058] Bank 400 is formed on the circuit device layer 200. In particular, bank 400 is formed such that it covers one end of the first electrode 300. Thus, the multiple first electrodes 300 formed by each pixel can be insulated from each other by bank 400.

[0059] The emission layer 500 is formed within the emission range defined by bank 400. The emission layer 500 can emit red (R), green (G), or blue (B) light, but is not limited to these colors. If required, the emission layer 500 can emit white light. In this case, a color filter can be additionally placed in a propagation path of the light emitted by the emission layer 500.

[0060] The emission layer 500 can be structured by each pixel in an evaporation process using a mask, or can be structured by each pixel without a mask in a liquid process using an inkjet device.

[0061] The emission layer 500 can contain at least one organic layer consisting of a hole injection layer, a hole transport layer, an organic emission layer, an electron transport layer and an electron injection layer.

[0062] The second electrode 600 is formed on the emission layer 500, whereby the second electrode 600 can function as a cathode of the electroluminescent display device.

[0063] The second electrode 600 can be formed on bank 400 as well as the emission layer 500, and can be formed in multiple emission areas. Thus, the second electrode 600 can function as a common electrode for applying a common voltage to multiple pixels.

[0064] The second electrode 600 can comprise: a first section 601 formed on a side surface 401 of the bank 400, a second section 602 formed on a top surface 402 of the bank 400, and a third section 603 formed on the emission layer 500. The first section 601, the second section 602, and the third section 603 can be formed from the same material and can be joined together to form an integral body. A side surface can be considered any surface that is substantially oblique or perpendicular to the surface of the substrate.

[0065] According to a lateral angle (θ) of the bank 400, obtained by a top surface of the first electrode 300 and the side surface 401 of the bank 400, the first section 601 of the second electrode 600, which is formed on the side surface 401 of the bank 400, changes its thickness. For example, if the lateral angle (θ) of the bank 400 is increased, the thickness of the first section 601 of the second electrode 600 will be relatively smaller than the thickness in the second section 602 and in the third section 603 of the second electrode 600. If the lateral angle (θ) of the bank 400 is decreased, the thickness of the first section 601 of the second electrode 600 will be similar to the thickness in the second section 602 and in the third section 603 of the second electrode 600. The height is measured in a direction perpendicular to the surface of the substrate, and the width is measured in a direction parallel to the surface of the substrate.The height (h1) of an emission layer is measured from the top surface of the first electrode 300. The height of a second electrode 600 is also measured from the top surface of the first electrode 300. The height of a bank 400 is measured from the top surface of the planarization layer 270. The edge of the emission region can be visualized as extending to the top surface of the emission region that is in direct contact with the bank. The top surface of a structural element is the surface of the structural element that is furthest from the first substrate and runs parallel to the surface of the substrate.

[0066] To overcome a problem related to a combustion phenomenon or a disconnection of the wiring in the first section 601 of the second electrode 600, the lateral angle (θ) of the bank 400 is preferably reduced. However, if the emission layer 500 is formed by the inkjet process, a large lateral angle (θ) is advantageous because it preferably prevents the emission layer 500, formed in one emission region, from penetrating into another emission region. Therefore, there are limitations to reducing the lateral angle (θ) in the bank 400.

[0067] The first section 601 has an inclined surface with respect to a horizontal surface, which means that the thickness of the first section 601 is less than the thickness of the second section 602 or the thickness of the third section 603. Consequently, the resistance of the first section 601 is increased, which can lead to problems related to the burning phenomenon or the separation of the wiring. A horizontal surface can be understood as any surface that is essentially parallel to the surface of the substrate.

[0068] This problem, related to the burning phenomenon or the disconnection of the wiring, can arise due to the insufficient thickness of the second electrode 600. Therefore, if the overall thickness of the second electrode 600 is increased, the thickness of the first section 601 of the second electrode 600, which is formed on the side surface 401 of the bank 400, will be increased to a certain extent, thus reducing the likelihood of the problem related to the burning phenomenon or the disconnection of the wiring caused by the increased resistance in the first section 601.

[0069] However, in the case of the upward-emitting type, where the light emitted by the emission layer 500 propagates upwards, increasing the thickness of the second electrode 600 can reduce the light transmittance. That is, there are limitations to increasing the thickness of the second electrode 600. Therefore, the problem associated with the burning phenomenon or the disconnection of the wiring in the first section 601 of the second electrode 600 can become serious.

[0070] In the case of the downward-emitting type, however, where the light emitted by the emissive layer 500 propagates downwards, the light transmittance is not reduced even if the thickness of the second electrode 600 is increased. This means that it is possible to provide the second electrode 600 with a greater thickness and thus reduce the likelihood of problems related to burning or wiring failure in the first section 601 of the second electrode 600. Accordingly, the problem related to burning or wiring failure in the first section 601 of the second electrode 600 may be much more pronounced in the upward-emitting type than in the downward-emitting type.

[0071] The conductive layer 700 is formed on the second electrode 600 while in contact with the second electrode 600, so that it is possible to avoid the problem associated with the burning phenomenon or the disconnection of the wiring in the first section 601 of the second electrode 600.

[0072] The conductive layer 700 contains a first section 701 and a second section 702.

[0073] The first section 701 of the conductive layer 700 is formed on the first section 601 of the second electrode 600. In particular, the first section 701 of the conductive layer 700 covers the first section 601 of the second electrode 600. Thus, even if the first section 601 of the second electrode 600 has a small thickness, the resistance in the first section 601 of the second electrode 600 is reduced because the first section 701 of the conductive layer 700 is additionally arranged on the first section 601 of the second electrode 600, thereby avoiding the problem associated with the burning phenomenon or the disconnection of the wiring in the first section 601 of the second electrode 600.

[0074] The second section 702 of the conductive layer 700 is formed on the second section 602 of the second electrode 600. Specifically, the second section 702 of the conductive layer 700 covers the second section 602 of the second electrode 600. The second section 702 of the conductive layer 700 overlaps the bank 400 but does not overlap the emission layer 500. Thus, the light transmittance is not reduced by the second section 702 of the conductive layer 700, and rather, the overall resistance of the second electrode 600 is reduced by the second section 702 of the conductive layer 700.

[0075] Preferably, one end of the first section 701 of the conductive layer 700 is in contact with a contact point where the first section 601 of the second electrode 600 meets the third section 603 of the second electrode 600. If the first section 701 of the conductive layer 700 extends along the third section 603 of the second electrode 600, the light transmittance of the emission region can be reduced.

[0076] Due to the properties of the manufacturing process, the thickness of the first section 701 of the conductive layer 700 may be smaller than the thickness of the second section 702 of the conductive layer 700.

[0077] The conductive layer 700 and the second electrode 600 can be formed from the same material. In this case, the second electrode 600 and the conductive layer 700 can be formed by continuous manufacturing processes using the same apparatus. In the case of the upward-radiating type, the conductive layer 700 and the second electrode 600 can be formed from the same transparent conductive material, but are not limited to this method.

[0078] The material for the conductive layer 700 can be different from the material for the second electrode 600. For example, the conductive layer 700 can be made of a metallic material with good conductivity. Alternatively, the conductive layer 700 can be made of a reflective material such as silver (Ag). In this case, light emitted by the emission layer 400 is reflected onto the first section 701 of the conductive layer 700, thus improving the light emission efficiency.

[0079] Furthermore, although not shown, an encapsulation layer can be formed on the conductive layer 700 to prevent moisture from penetrating the emission layer 500. The encapsulation layer can be formed from an inorganic insulating material or in a deposition structure obtained by alternating deposition of an inorganic insulating material and an organic insulating material, but is not limited to these structures.

[0080] As in Fig. As shown in Figure 3B, in the case of the active area (AA), bank 400 is formed in a matrix configuration, thus defining an aperture section corresponding to several pixel regions. That is, the aperture section where bank 400 is not formed becomes the emission area (E), and the emission layer 500 is formed in the emission area (E).

[0081] Furthermore, the conductive layer 700 is provided while overlapping the bank 400. The conductive layer 700 includes the second section 702, which overlaps the bank 400, and the first section 701, which overlaps the end of the emission layer 500. From a top view, the conductive layer 700 is structured in a shape identical to the shape of the bank 400. Unlike the bank 400, the conductive layer 700 partially overlaps the emission layer 500. If the overlap area between the emission layer 500 and the first section 701 of the conductive layer 700 is increased, the light transmittance in the emission area (E) is reduced. Thus, it is preferred that the overlap area be of a small size.

[0082] Fig. Figure 4 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure. With the exception of the structures of a bank 400 and an emission layer 500, the electroluminescent display device has Fig. 4 the same structure as the electroluminescent display device of the Fig. 3A and Fig. 3B, which is why the same reference numbers are used in all drawings to denote identical parts. Only the structural differences are described below.

[0083] As in Fig. As shown in Figure 4, according to a further embodiment of the present disclosure, a bank 400 contains a first bank 410 and a second bank 420.

[0084] The first bank 410 covers one end of a first electrode 300 and is formed on a circuit device layer 200. The thickness of the first bank 410 is relatively smaller than the thickness of the second bank 420, and the width of the first bank 410 is relatively larger than the width of the second bank 420. Like an emission layer 500, the first bank 410, which has the structure described above, possesses hydrophilic properties. The first bank 410, which has hydrophilic properties, can be formed from an inorganic insulating material such as silicon dioxide. Thus, if the emission layer 500 is formed by an inkjet process, a solution for forming the emission layer 500 can be easily distributed on the first bank 410.

[0085] The second bank 420 is formed on the first bank 410. The width of the second bank 420 is smaller than the width of the first bank 410. The second bank 420 can be obtained by: coating a solution mixture of an organic insulating material exhibiting hydrophilic properties and a hydrophobic material, such as fluorine, and structuring the coated solution mixture using a photolithography process. The light emitted during the photolithography process causes the hydrophobic material, such as fluorine, to migrate to an upper section of the second bank 420, thereby giving the upper section of the second bank 420 its hydrophobic properties and the remaining sections of the second bank 420 its hydrophilic properties.This means that the lower section of the second bank 420, which is in contact with the first bank 410, has the hydrophilic property, and the upper section of the second bank 420 has the hydrophobic property, but this is not limited to this structure. The entire section of the second bank 420 can have the hydrophobic property.

[0086] In the present text, the spreadability of the solution for forming the emission layer 500 can be improved thanks to the first bank 410, which exhibits hydrophilic properties, and the lower section of the second bank 420, which also exhibits hydrophilic properties. Since the first bank 410 has a relatively smaller thickness and a relatively larger width compared to the second bank 420, it is particularly possible to create a two-step structure based on its hydrophilic properties by combining the first bank 410 and the second bank 420. This allows the solution for forming the emission layer 500 to be easily distributed to the left and right ends of the emission region.

[0087] Furthermore, the upper section of the second bank 420, which has the hydrophobic property, prevents the solution for forming the emission layer 500 from spreading to another adjacent emission area, so that it is possible to prevent the emission layer 500 of one emission area from mixing with the emission layer 500 of another adjacent emission area.

[0088] The first or second bank can have a linear structure in the active area. A linear structure is a straight structure, meaning the bank extends along a first direction and has a constant cross-section perpendicular to that direction. The first bank can be configured as a grid structure, which is a structure comprising a single layer with multiple regular openings, typically rectangular, arranged in a rectangular grouping that defines a regular structure of emission areas in the active area. An electroluminescent display device can comprise multiple second banks of a linear structure, parallel to each other and formed on a first bank that has a grid structure.An electroluminescent display device can comprise several second banks of linear structure running parallel to each other and formed on top of several first banks of linear structure that run parallel to each other and perpendicular to the linear structure of the second banks. A bank with a linear structure only needs to have such a structure in the active area. In some cases, a bank can be formed from several linear structures running parallel to each other and connected in the dummy area surrounding the active area, thus forming a serpentine structure.

[0089] The emission layer 500 is formed on the first electrode 300. The emission layer 500 can be formed by inkjet printing. When the emission layer 500 is formed by inkjet printing, the height (h1) of the upper end of the emission layer 500 in the middle of the emission area, after a drying process for drying the solution used to form the emission layer 500, is lower than the height (h2) of the upper end of the emission layer 500 at the end of the emission area. In particular, as shown in the drawings, if the height of the emission layer 500 is gradually reduced from the end of the emission area to the middle of the emission area, it is possible to achieve a shape with a gradually sloping profile.

[0090] Accordingly, a predefined section of a second electrode 600 formed on the emission layer 500 can have a profile corresponding to the profile of the emission layer 500. In this case, the thickness in a predefined section of the second electrode 600 formed on a side face of the second bank 420 is relatively smaller than the thickness of the other sections of the second electrode 600. As described above, a conductive layer 700 can prevent problems related to a burning phenomenon or a disconnection of the wiring in a predefined section of the second electrode 600 formed on a side face of the second bank 420.

[0091] Fig. Figure 5 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment not representing the invention, showing a dummy area (DA) and an active area (AA) which are in Fig. 2 are shown.

[0092] As in Fig. As shown in Figure 5, a circuit device layer 200, a first electrode 300, a bank 400, an emission layer 500 and a second electrode 600 are formed on a substrate 100 in the active region (AA) and in the dummy region (DA).

[0093] A structure for each of the circuit device layer 200, the first electrode 300, the bank 400, the emission layer 500 and the second substrate 600, which are formed in the active region (AA), is formed with the structure described above. Fig. 3A or Fig. 4 identical, so a detailed description of the same structures is omitted.

[0094] The circuit device layer 200 formed in the dummy region (DA) can have the same structure as the circuit device layer 200 formed in the active region (AA), and the circuit device layer 200 formed in the dummy region (DA) and the circuit device layer 200 formed in the active region (AA) can be manufactured by the same process, but this is not strictly necessary. That is, some of the signal lines, such as a gate line, a data line, a power line, and a reference line, do not need to be included in the circuit device layer 200 formed in the dummy region (DA), nor do some components of a switching thin-film transistor and a drive thin-film transistor need to be included in the circuit device layer 200 formed in the dummy region (DA), so that no light emission needs to be generated in the dummy region (DA).If required, the circuit device layer 200 formed in the dummy area (DA) can be incompletely configured so that neither of the switching thin-film transistors nor the driving thin-film transistor is operated.

[0095] The first electrode 300 formed in the dummy region (DA) can have the same structure as the first electrode 300 formed in the active region (AA), and both the first electrode 300 formed in the dummy region (DA) and the first electrode 300 formed in the active region (AA) can be manufactured using the same process. The first electrode 300 does not need to be formed in the dummy region (DA), so no light emission needs to be generated in the dummy region (DA).

[0096] The emission layer 500 formed in the dummy region (DA) can have the same structure as the emission layer 500 formed in the active region (AA), and both the emission layer 500 formed in the dummy region (DA) and the emission layer 500 formed in the active region (AA) can be produced using the same process. In contrast to the emission layer 500 formed in the active region (AA), some organic layers can be removed from the emission layer 500 formed in the dummy region (DA), so that no light emission needs to be generated in the dummy region (DA).

[0097] A conductive layer 700 is formed on the second electrode 600, which is located in the active area (AA). As described above, the conductive layer 700 prevents burning or disconnection of the wiring in a predefined section of the second electrode 600, which is located on a side face of the bank 400. A detailed description of the structure of the conductive layer 700 is omitted.

[0098] The structure of the conductive layer 700 in the active region (AA) differs from the structure of the conductive layer 700 in the dummy region (DA). More precisely, the conductive layer 700 is not formed in the dummy region (DA). In this specification, the structure of the conductive layer 700 in the dummy region (DA) can be understood to mean that the conductive layer 700 is not formed in the dummy region (DA).

[0099] No image is displayed in the dummy area (DA). This means that even if the problem arises in the second electrode 600, which is located in the dummy area (DA), it has no effect on the image quality. Accordingly, the conductive layer 700 is formed only in the active area (AA), but not in the dummy area (DA).

[0100] Fig. Figure 6 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure. With the exception of a structure of the conductive layer 700, the electroluminescent display device is of Fig. 6 structurally with the electroluminescent display device of Fig. 5. The same reference numbers are used in all drawings to denote identical parts. Only the structural differences are described in detail below.

[0101] As above in Fig. As described in section 5, the conductive layer 700 is formed in the active region (AA), but not in the dummy region (DA). As described in Fig. As can be seen in Figure 6, the conductive layer 700 is formed not only in the active region (AA) but also in the dummy region (DA). However, the structure of the conductive layer 700 formed in the active region (AA) differs from the structure of the conductive layer 700 formed in the dummy region (DA).

[0102] The conductive layer 700 formed in the active region (AA) extends to one end of an emission region in such a way as to minimize any overlap with an emission layer 500, thereby preventing a reduction in light transmittance. The conductive layer 700 in the dummy region (DA) is formed such that it completely overlaps the emission layer 500.

[0103] This means that the overlap area between the conductive layer 700 and the emission layer 500 in the dummy region (DA) is relatively larger than the overlap area between the conductive layer 700 and the emission layer 500 in the active region (AA). Furthermore, the structure of the conductive layer 700 in the dummy region (DA) is identical to the structure of a second electrode 600 in the dummy region (DA).

[0104] No image is displayed in the dummy area (DA), thus avoiding a problem related to reduced light transmittance in the dummy area (DA). Accordingly, in the case of the Fig. In the structure shown in Figure 6, the surface area of ​​the conductive layer 700 is increased, thus reducing the overall resistance of the second electrode 600.

[0105] Fig. Figure 7 is a cross-sectional view illustrating an electroluminescent display device according to a further embodiment of the present disclosure, relating to an active area of ​​an upward-radiating electroluminescent display device.

[0106] As in Fig. As shown in Figure 7, the electroluminescent display device according to a further embodiment of the present disclosure can include a substrate 100, a circuit device layer 200, a first electrode 300, an auxiliary electrode 350, a bank 400, an emission layer 500, a second electrode 600 and a conductive layer 700.

[0107] The circuit device layer 200 can contain an active layer 210, a gate insulating film 220, a gate electrode 230, an insulating intermediate layer 240, a source electrode 250a, a drain electrode 250b, a passivation layer 260 and a planarization layer 270.

[0108] The active layer 210 is formed on the substrate 110. The active layer 210 can be formed from a silicon-based or an oxide-based semiconductor material, but is not limited to these materials. Although not shown, a light-shielding layer can additionally be placed between the substrate 100 and the active layer 210, thus preventing light from propagating to the active layer 210 and preventing its degradation.

[0109] The gate insulating film 220 is formed on the active layer 210, thereby isolating the active layer 210 and the gate electrode 230 from each other.

[0110] The gate electrode 230 is formed on the gate insulating film 220.

[0111] The insulating intermediate layer 240 is formed on the gate electrode 230, wherein the insulating intermediate layer 240 insulates the gate electrodes 230 from the source / drain electrode 250a / 250b.

[0112] The source electrode 250a is positioned at a predetermined distance from the drain electrode 250b, with the source electrode 250a and the drain electrode 250b facing each other and located in the insulating intermediate layer 240. The source electrode 250a and the drain electrode 250b are each connected to one end and the other end of the active layer 210 via contact holes located in the insulating intermediate layer 240 and the gate insulating film 220.

[0113] The passivation layer 260 is placed on the source electrode 250a and the drain electrode 250b, thereby protecting a thin-film transistor.

[0114] The planarization layer 270 is formed on the passivation layer 260, thereby planarizing a surface of the substrate 100.

[0115] Accordingly, the circuit device layer 200 contains the thin-film transistor, which has the gate electrode 230, the active layer 210, the source electrode 250a and the drain electrode 250b. Fig. Figure 7 shows the thin-film transistor having a top-gate structure, where the gate electrode 230 is located above the active layer 210, but is not limited to this type. For example, the thin-film transistor having a bottom-gate structure, where the gate electrode 230 is located below the active layer 210, can be arranged in the circuit device layer 200.

[0116] The circuit device layer 200 can contain a switching thin-film transistor, a drive thin-film transistor, a read thin-film transistor, and a capacitor. The in Fig. The thin-film transistor shown in image 7 corresponds to the control thin-film transistor.

[0117] The electroluminescent display device of Fig. 7 corresponds to an upward-emitting type. This means that even if the thin-film transistor is located below the emission layer 500, the light emission is not affected by the thin-film transistor. Therefore, the thin-film transistor can be located below the emission layer 500.

[0118] The first electrode 300 is formed on the circuit device layer 200. The first electrode 300 is connected to the drain electrode 250b of the thin-film transistor via the contact hole formed in the planarization layer 270 and the passivation layer 260. If required, the first electrode 300 can be connected to the source electrode 250a of the thin-film transistor via the contact hole located in the planarization layer 270 and the passivation layer 260.

[0119] The auxiliary electrode 350 is formed on the circuit device layer 200. The auxiliary electrode 350 is positioned at a predetermined distance from the first electrode 300. The auxiliary electrode 350 and the first electrode 300 can be made of the same material and can be manufactured using the same process.

[0120] The auxiliary electrode 350 is provided to reduce the resistance of the second electrode 600. In the case of the in Fig. In the electroluminescent display device of the upward-emitting type shown in Figure 7, the second electrode 600 can be made of a transparent conductive material. However, the transparent conductive material has a disadvantage due to its high resistance. Therefore, the second electrode 600 made of transparent conductive material is connected to the auxiliary electrode 350, which is made of a material with good conductivity, thus reducing the resistance of the second electrode 600.

[0121] The bank 400 is positioned on the planarization layer 270, configured to cover both ends of the first electrode 300. The contact hole 401 is located in the bank 400, exposing the auxiliary electrode 350 through the contact hole 401. In this case, the bank 400 is configured to cover both ends of the auxiliary electrode 350. If the bank 400 is provided with a first bank 410 and a second bank 420, as shown above in Fig. As described in 4, a contact hole is formed in each of the first bank 410 and the second bank 420, thereby exposing the auxiliary electrode 350 via the contact hole located in each of the first bank 410 and the second bank 420.

[0122] The emission layer 500 is formed on the first electrode 300.

[0123] The second electrode 600 is formed on the entire surface of an active region. More precisely, the second electrode 600 is formed on the upper and lateral surfaces of the bank 400 and is also formed on the top surface of the emission layer 500. Furthermore, the second electrode 600 extends along a lateral surface of the contact hole 401 formed in the bank 400 and is then connected to the auxiliary electrode 350.

[0124] That is, the second electrode 600 comprises a first section 601 formed on the side surface of the bank 400, a second section 602 formed on the top surface of the bank 400, a third section 603 formed on the top surface of the emission layer 500, and a fourth section 604 extending to the auxiliary electrode 350 along the side surface of the contact hole 401 formed in the bank 400. The fourth section 604 of the second electrode 600 extends into the interior of the contact hole 401.

[0125] Each of the first section 601 and the fourth section 604 of the second electrode 600 is relatively thinner than each of the second section 602 and the third section 603 of the second electrode 600. Accordingly, problems related to a burning phenomenon or a disconnection of the wiring in the first section 601 and the fourth section 604 of the second electrode 600 may occur.

[0126] The conductive layer 700 is formed on the second electrode 600. The conductive layer 700 comprises a first section 701, which is formed on the first section 601 of the second electrode 600, a second section 702, which is formed on the second section 602 of the second electrode 600, and a third section 703, which is formed on the fourth section 604 of the second electrode 600. The third section 703 of the conductive layer 700 extends into the interior of the contact hole 401.

[0127] The first section 701 and the third section 703 of the conductive layer 700 are each formed on the first section 601 and the fourth section 604 of the second electrode 600, thereby reducing resistance in the first section 601 and the fourth section 604 of the second electrode 600, thus avoiding problems related to a burning phenomenon or a disconnection of the wiring.

[0128] According to the present disclosure, the conductive layer is arranged on the electrode. In particular, the conductive layer is arranged such that it is in contact with the relatively thin first section of the electrode, thus making it possible to avoid problems associated with a burning phenomenon or a disconnection of the wiring in the first section of the electrode.

[0129] It is obvious to those skilled in the art that the present disclosure described above is not limited by the embodiments described above and the accompanying drawings, and that various substitutions, modifications, and variations can be made to the present disclosure without altering its scope of protection. Consequently, the scope of protection of the present invention is defined by the accompanying claims. It is intended that all variations or modifications derived from the meaning, scope of protection, and an equivalent concept of the disclosure fall within the scope of protection of the accompanying claims.

[0130] The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified as necessary to incorporate concepts from the various patents, applications, and publications to provide further embodiments.

[0131] These and other modifications may be made to the embodiments in light of the detailed description above. In general, the terms used in the following claims should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification, but rather as encompassing the full scope of protection to which such claims are entitled. The following list provides embodiments of the disclosure and forms part of the description. These embodiments may be combined in any compatible combination in addition to those expressly set forth. The embodiments may also be combined with any compatible features described in this text. Embodiment 1. An electroluminescent display device comprising the following: a substrate; a first electrode that is positioned on the substrate; a bank configured to cover one end of the first electrode and define an emission area; an emission layer located on the first electrode in the emission area defined by the bank; a second electrode, which is arranged on the emission layer and the bank; and a conductive layer that is placed on the second electrode while in contact with the second electrode, wherein the second electrode includes a first section arranged on a side surface of the bank, a second section arranged on a top surface of the bank, and a third section arranged on a top surface of the emission layer, and the conductive layer contains a first section that is located on the first section of the second electrode. The conductive layer may also contain a second section, which is additionally arranged on the second section of the second electrode. One end of the first section of the conductive layer can be in contact with a contact point where the first section of the second electrode meets the third section of the second electrode. An auxiliary electrode can be electrically connected to the second electrode and positioned under the bench. The bench may contain a contact hole to expose the auxiliary electrode. The second electrode may contain a fourth section that extends along a side surface of the contact hole in addition to the auxiliary electrode. The conductive layer may contain a third section, which is additionally arranged on the fourth section of the second electrode. The conductive layer and the second electrode can be made from the same material. The conductive layer may contain a reflective material. The height of the upper end of the emission layer in the middle of the emission range can be relatively lower than the height of the upper end of the emission layer at the end of the emission range. The bench can contain a first bench and a second bench arranged on top of the first. The second bench can have a relatively smaller width and a relatively greater thickness compared to the first bench. Embodiment 2. An electroluminescent display device comprising the following: a substrate containing an active region and a dummy region formed in the periphery of the active region; a bank that is positioned on the active area and the dummy area of ​​the substrate and is configured to define an emission area; an emission layer that is located in the emission area defined by the bank; an electrode positioned on the bank and the emission layer; and a conductive layer that is placed on the electrode while it is in contact with the electrode, where the structure of the conductive layer in the active region is different from the structure of the conductive layer in the dummy region. The structure of the conductive layer is preferably not arranged in the dummy area. An overlap area between the emission layer and the conductive layer structure in the dummy region can be larger than an overlap area between the emission layer and the conductive layer structure in the active region. The structure of the conductive layer in the dummy area can be identical to the structure of the electrode in the dummy area. The electrode can contain: a first section located on a side surface of the bank, a second section located on a top surface of the bank, and a third section located on a top surface of the emission layer. The structure of the conductive layer in the active area may include a first section that is located on the first section of the electrode. The structure of the conductive layer in the active area may include a second section that is additionally arranged on the second section of the electrode. One end of the first section in the structure of the conductive layer, which is located in the active area, can be in contact with a contact point where the first section of the electrode meets the third section of the electrode. Embodiment 15. The electroluminescent display device according to embodiment 12, which further comprises an auxiliary electrode that is electrically connected to the electrode and is arranged under the bench. The bench may contain a contact hole to expose the auxiliary electrode. The electrode may contain a fourth section that extends along a side surface of the contact hole in addition to the auxiliary electrode. The structure of the conductive layer in the active area may include a third section, which is additionally arranged on the fourth section of the electrode. Embodiment 3. An electroluminescent display device comprising the following: a substrate; a bank configured to define an emission area on the substrate; an emission layer that is located in the emission area defined by the bank; an electrode arranged on the emission layer and the bank; and a conductive layer arranged on the electrode, wherein the electrode contains a first section which has a relatively small thickness, and a second section which has a relatively large thickness, and the conductive layer is in contact with the first section of the electrode. The first section of the electrode may have an inclined surface that is inclined with respect to a horizontal surface. The first section of the electrode can be arranged on a side surface of the bench. Embodiment 4. An electroluminescent display device comprising the following: a substrate; a bank configured to define an emission area on the substrate; an emission layer located within the emission area defined by the bank; and an electrode that is positioned on the emission layer and the bank; wherein the electrode contains a first section having a first thickness, and a second section having a second thickness, the second thickness being greater than the first thickness, and wherein the height of the emission layer in the middle of the emission region is less than the height of the emission layer at the edge of the emission region.

[0132] A conductive layer can be arranged on the electrode, with the conductive layer being in contact with the first section of the electrode.

[0133] The first section of the electrode can be in direct contact with the bank.

[0134] The electrode can have a profile that corresponds to the profile of the emission layer in the emission area.

[0135] The substrate can contain an active region and a dummy region around the perimeter of the active region.

[0136] The structure of the conductive layer in the active region can be different from the structure of the conductive layer in the dummy region.

[0137] The bank can be formed on a circuit device layer that includes a thin-film transistor.

[0138] An auxiliary electrode can be electrically connected to the main electrode and positioned beneath the electrode bank. The electrode bank may include a contact hole to expose the auxiliary electrode. The electrode may comprise: a first section located on a side face of the electrode bank, a second section located on the top of the electrode bank, a third section located on the top of the emission layer, and a fourth section extending to the auxiliary electrode along a side face of the contact hole. The conductive layer may be located on the first, second, and fourth sections of the electrode.

[0139] The first section of the electrode may have an inclined surface that is inclined with respect to a horizontal surface.

[0140] The first section of the electrode can be arranged on a side surface of the bench.

[0141] Another electrode can be provided, with the electrode and the other electrode configured to form an electric field in such a way that the emission layer emits light.

Claims

[1] Electroluminescent display device comprising: a substrate (100); a bank (400) configured to define an emission range (E); an emission layer (500) located in the emission area (E) defined by the bank (400); an electrode (600) arranged on the emission layer (500) and on the bank (400); and a conductive layer (700) arranged on a section of the electrode (600) which is arranged on the bench (400), wherein the substrate (100) contains an active region (AA) and a dummy region (DA) at a circumferential edge of the active region (AA), characterized by , that the conductive layer (700) in the active area (AA) is arranged exclusively on the bank (400) and in the dummy area (DA) is arranged on the bank (400) and on the emission layer (500). [2] Electroluminescent display device according to claim 1, wherein the conductive layer (700) exposes at least a section of the electrode (600) in the emission area (E), and / or wherein the conductive layer (700) is in contact with the electrode (600) at a point where the section of the electrode (600) that is located on the bench (400) and the section of the electrode (600) that is located on the emission layer (500) meet. [3] Electroluminescent display device according to any one of the preceding claims, wherein: the electrode (600) comprises: a first section (601) arranged on a side surface (401) of the bank (400), a second section (602) arranged on a top surface (402) of the bank (400), and a third section (603) arranged on the emission layer (500), and the conductive layer (700) contains a first section (701) which is arranged on the first section (601) of the electrode. [4] Electroluminescent display device according to claim 3, wherein the conductive layer (700) further comprises a second section (702) which is arranged on the second section (602) of the electrode (600). [5] Electroluminescent display device according to claim 3 or 4, wherein the bank (400) is arranged on an auxiliary electrode (350) and includes a contact hole to expose the auxiliary electrode (350), and the electrode (600) is electrically connected to the auxiliary electrode (350) which is exposed through the contact hole, and includes a fourth section (604) which is arranged on a side face of the contact hole, and the conductive layer (700) contains a third section (703) which is arranged on the fourth section (604) of the electrode (600). [6] Electroluminescent display device according to any of the preceding claims, wherein the conductive layer (700) and the electrode (600) are made of the same material, and / or wherein the conductive layer (700) contains a reflective material. [7] Electroluminescent display device according to one of the preceding claims, wherein the bank (400) is arranged in the active area (AA) and in the dummy area (DA); and wherein a structure of the conductive layer (700) in the active area (AA) has a different shape than a structure of the conductive layer (700) in the dummy area (DA). [8] Electroluminescent display device according to claim 7, wherein an overlap area between the emission layer (500) and the structure of the conductive layer (700) in the dummy area (DA) is larger than an overlap area between the emission layer (500) and the structure of the conductive layer (700) in the active area (AA). [9] Electroluminescent display device according to claim 7 or 8, wherein the structure of the conductive layer (700) in the dummy area (DA) is identical to the structure of the second electrode (600) in the dummy area (DA). [10] Electroluminescent display device according to any of the preceding claims, if dependent on claim 3, wherein the first section (601) of the electrode (600) has a first thickness and wherein the second and / or the third section (602, 603) of the electrode (600) has a second thickness, wherein the second thickness is greater than the first thickness. [11] Electroluminescent display device according to any of the preceding claims, if dependent on claim 3, wherein the first section (601) of the electrode (600) has an inclined surface which is inclined with respect to a horizontal surface or with respect to the third section (603) of the electrode (600).

Images