Display device

Abstract

To provide a display device in which the decrease in reliability can be suppressed.SOLUTION: A display device in an embodiment includes: a substrate; an organic insulating layer disposed on the substrate and having a concave part; a lower electrode disposed in the concave part and embedded in the organic insulating layer; a rib having a pixel opening overlapping with the lower electrode; an auxiliary wire having a lower part with conductivity disposed on the rib and an upper part having an end part projecting from a side surface of the lower part; an upper electrode facing the lower electrode and connected to the auxiliary wire; and an organic layer disposed between the lower electrode and the upper electrode and emitting light in accordance with a potential difference between the lower electrode and the upper electrode. An upper surface of the lower electrode is exposed from the organic insulating layer at the pixel opening and is in contact with the organic layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present embodiment relates to a display device. [Background technology]

[0002] In recent years, display devices using organic light-emitting diodes (OLEDs) as display elements have been put to practical use. Such display elements include a lower electrode, an organic layer covering the lower electrode, and an upper electrode covering the organic layer. The organic layer is formed by, for example, a vacuum deposition method.

[0003] For example, in the case of mask deposition, a fine mask having an opening corresponding to each pixel is used. However, when considering the processing accuracy of the fine mask, it is difficult to achieve a higher resolution than the current resolution or a higher aperture ratio than the current aperture ratio.

[0004] Therefore, a technique has been devised in which the organic layer and the upper electrode are divided using a pixel division structure instead of a fine mask. However, when the pixel division structure is used, there is a risk that a part of the pixel division structure may adhere as a foreign body, causing a display defect, or that the accuracy of forming the thin film may decrease due to deformation of the pixel division structure. This reduces the reliability of the display device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-135325 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a display device capable of suppressing a decrease in reliability. [Means for solving the problem]

[0007] A display device according to one embodiment includes a substrate, an organic insulating layer disposed on the substrate and having a recess, a lower electrode disposed in the recess and embedded in the organic insulating layer, a rib having a pixel opening overlapping the lower electrode, an auxiliary wiring including a conductive lower portion disposed on the rib and an upper portion having an end protruding from a side surface of the lower portion, an upper electrode facing the lower electrode and connected to the auxiliary wiring, and an organic layer disposed between the lower electrode and the upper electrode and emitting light in response to a potential difference between the lower electrode and the upper electrode. An upper surface of the lower electrode is exposed from the organic insulating layer at the pixel opening and in contact with the organic layer.

[0008] A display device according to one embodiment includes a substrate, a first organic insulating layer disposed on the substrate, a second organic insulating layer disposed on the first organic insulating layer, a lower electrode embedded in the first organic insulating layer and the second organic insulating layer, a rib having a pixel opening overlapping the lower electrode, an auxiliary wiring including a conductive lower portion disposed on the rib and an upper portion having an end protruding from a side surface of the lower portion, an upper electrode facing the lower electrode and connected to the auxiliary wiring, and an organic layer disposed between the lower electrode and the upper electrode and emitting light in response to a potential difference between the lower electrode and the upper electrode. An upper surface of the lower electrode is exposed from the second organic insulating layer at the pixel opening and is in contact with the organic layer. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a display device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of the configuration of a display panel according to the embodiment. [Diagram 3] FIG. 3 is a view for explaining a step of forming a lower electrode according to the embodiment. [Figure 4] FIG. 4 is a diagram for explaining a process for forming the display element according to the embodiment. [Diagram 5] FIG. 5 is a diagram illustrating a process for forming the display element according to the embodiment. [Figure 6] FIG. 6 is a diagram illustrating a process for forming the display element according to the embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the configuration of a display panel according to a comparative example. [Figure 8] FIG. 8 is a cross-sectional view showing an example of the configuration of a display panel according to a comparative example. [Figure 9] FIG. 9 is a cross-sectional view showing an example of the configuration of a display panel according to a first modified example. [Figure 10] FIG. 10 is a cross-sectional view showing an example of the configuration of a display panel according to a first modified example. [Figure 11] FIG. 11 is a cross-sectional view showing an example of the configuration of a display panel according to the second modified example. [Figure 12] FIG. 12 is a cross-sectional view showing an example of the configuration of a display panel according to the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In addition, the disclosure is merely an example, and the invention is not limited to the contents described in the following embodiments. Modifications that a person skilled in the art can easily conceive are naturally included in the scope of the disclosure. In order to make the explanation clearer, the size, shape, etc. of each part may be changed from the actual embodiment and shown diagrammatically. In multiple drawings, corresponding elements may be given the same reference numerals, and detailed explanations may be omitted.

[0011] In the drawings, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are shown as necessary to facilitate understanding. The direction along the X-axis is called the first direction, the direction along the Y-axis is called the second direction, and the direction along the Z-axis is called the third direction. The third direction Z is a normal direction to a plane that includes the first direction X and the second direction Y. Moreover, viewing various elements parallel to the third direction Z is called planar view.

[0012] The display device according to this embodiment is an organic electroluminescence display device having an organic light-emitting diode (OLED) as a display element, and can be mounted in various electronic devices such as televisions, personal computers, in-vehicle devices, tablet terminals, smartphones, mobile phone terminals, and wearable terminals.

[0013] 1 is a diagram showing a configuration example of a display device DSP according to this embodiment. The display device DSP includes a display panel PNL including an insulating substrate 10. The display panel PNL has a display area DA for displaying an image and a peripheral area SA around the display area DA. The substrate 10 may be glass or a flexible resin film.

[0014] In this embodiment, the shape of the substrate 10 in a plan view is rectangular. However, the shape of the substrate 10 in a plan view is not limited to rectangular, and may be other shapes such as square, circular, or elliptical.

[0015] The display area DA includes a plurality of pixels PX arranged in a matrix in a first direction X and a second direction Y. Each pixel PX includes a plurality of subpixels SP. In one example, the pixel PX includes a red subpixel SP1, a green subpixel SP2, and a blue subpixel SP3. The pixel PX may include a subpixel SP of another color, such as white, in addition to the subpixels SP1, SP2, and SP3, or instead of any of the subpixels SP1, SP2, and SP3.

[0016] The subpixel SP includes a pixel circuit 1 and a display element DE driven by the pixel circuit 1. The pixel circuit 1 includes a pixel switch 2, a drive transistor 3, and a capacitor 4. The pixel switch 2 and the drive transistor 3 are switching elements constituted by, for example, thin film transistors.

[0017] The gate electrode of the pixel switch 2 is connected to the scanning line GL. One of the source electrode and drain electrode of the pixel switch 2 is connected to the signal line SL, and the other is connected to the gate electrode of the drive transistor 3 and the capacitor 4. In the drive transistor 3, one of the source electrode and drain electrode is connected to the power line PL and the capacitor 4, and the other is connected to the display element DE.

[0018] It should be noted that the configuration of the pixel circuit 1 is not limited to the example shown in the drawing. For example, the pixel circuit 1 may include more thin film transistors and capacitors.

[0019] 2 is a schematic cross-sectional view of the display panel PNL according to this embodiment. A circuit layer 11 is disposed on the above-mentioned substrate 10. The circuit layer 11 includes various circuits and wirings such as the pixel circuits 1, scanning lines GL, signal lines SL, and power lines PL shown in FIG. 1. The circuit layer 11 is covered with an organic insulating layer 12.

[0020] The organic insulating layer 12 functions as a planarizing film that planarizes the unevenness caused by the circuit layer 11. The organic insulating layer 12 has a plurality of recesses 12a. In the recesses 12a, a lower electrode LE1 that constitutes the subpixel SP1 is disposed. In another recess 12a, a lower electrode LE2 that constitutes the subpixel SP2 is disposed. In yet another recess 12a, a lower electrode LE3 that constitutes the subpixel SP3 is disposed. In other words, the lower electrodes LE1, LE2, and LE3 are embedded in the organic insulating layer 12. Note that the process of forming the lower electrodes LE1, LE2, and LE3 will be described later, and therefore a detailed description thereof will be omitted here. The recesses described in this specification may also be referred to as contact holes.

[0021] A rib 13 is disposed on the organic insulating layer 12 and the lower electrodes LE1, LE2, and LE3. The rib 13 has pixel openings AP1, AP2, and AP3 in the subpixels SP1, SP2, and SP3, respectively. More specifically, the rib 13 has pixel openings AP1, AP2, and AP3 that expose parts of the lower electrodes LE1, LE2, and LE3.

[0022] An organic layer EL1 constituting the subpixel SP1 is disposed on the lower electrode LE1. The organic layer EL1 covers the lower electrode LE1 through the pixel aperture AP1. An upper electrode UE1 constituting the subpixel SP1 is disposed on the organic layer EL1. The upper electrode UE1 covers the organic layer EL1 and faces the lower electrode LE1.

[0023] An organic layer EL2 constituting the subpixel SP2 is disposed on the lower electrode LE2. The organic layer EL2 covers the lower electrode LE2 through the pixel aperture AP2. An upper electrode UE2 constituting the subpixel SP2 is disposed on the organic layer EL2. The upper electrode UE2 covers the organic layer EL2 and faces the lower electrode LE2.

[0024] An organic layer EL3 constituting the subpixel SP3 is disposed on the lower electrode LE3. The organic layer EL3 covers the lower electrode LE3 through the pixel aperture AP3. An upper electrode UE3 constituting the subpixel SP3 is disposed on the organic layer EL3. The upper electrode UE3 covers the organic layer EL3 and faces the lower electrode LE3.

[0025] The portions of the lower electrode LE1, organic layer EL1, and upper electrode UE1 that overlap with the pixel aperture AP1 constitute the display element DE1 of the subpixel SP1. The portions of the lower electrode LE2, organic layer EL2, and upper electrode UE2 that overlap with the pixel aperture AP2 constitute the display element DE2 of the subpixel SP2. The portions of the lower electrode LE3, organic layer EL3, and upper electrode UE3 that overlap with the pixel aperture AP3 constitute the display element DE3 of the subpixel SP3.

[0026] An insulating film PAS1 is disposed on the upper electrode UE1, an insulating film PAS2 is disposed on the upper electrode UE2, and an insulating film PAS3 is disposed on the upper electrode UE3. The insulating films PAS1, PAS2, and PAS3 continuously cover the upper electrodes UE1, UE2, and UE3 and the side surfaces of auxiliary wiring 14, which will be described later, respectively. The display elements DE1, DE2, and DE3 may further include these insulating films PAS1, PAS2, and PAS3. The rib 13 surrounds each of these display elements DE1, DE2, and DE3.

[0027] An auxiliary wiring 14 is disposed on the rib 13. The auxiliary wiring 14 includes a conductive lower portion 14a disposed on the rib 13 and an upper portion 14b disposed on the lower portion 14a. The upper portion 14b has a width greater than that of the lower portion 14a. As a result, both ends of the upper portion 14b protrude beyond the side surfaces of the lower portion 14a. The upper electrodes UE1, UE2, and UE3 are in contact with the side surfaces of the lower portion 14a of the auxiliary wiring 14, respectively.

[0028] Part of the organic layer EL1 and the upper electrode UE1 are located on the upper portion 14b of the auxiliary wiring 14, and the part is separated from the part of the organic layer EL1 and the upper electrode UE1 located under the auxiliary wiring 14 (part that constitutes the display element DE1). Similarly, part of the organic layer EL2 and the upper electrode UE2 are located on the upper portion 14b of the auxiliary wiring 14, and the part is separated from the part of the organic layer EL2 and the upper electrode UE2 located under the auxiliary wiring 14 (part that constitutes the display element DE2). Furthermore, part of the organic layer EL3 and the upper electrode UE3 are located on the upper portion 14b of the auxiliary wiring 14, and the part is separated from the part of the organic layer EL3 and the upper electrode UE3 located under the auxiliary wiring 14 (part that constitutes the display element DE3).

[0029] The organic insulating layer 12 is made of an organic insulating material. The ribs 13 are made of an insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), polyimide, or acrylic, or a combination of these insulating materials.

[0030] The lower electrodes LE1, LE2, and LE3 each have a reflective layer made of, for example, silver (Ag) and a pair of conductive oxide layers covering the upper and lower surfaces of the reflective layer. Each conductive oxide layer can be made of a transparent conductive oxide such as, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or IGZO (Indium Gallium Zinc Oxide).

[0031] The upper electrodes UE1, UE2, UE3 are formed of a metal material such as an alloy of magnesium and silver (MgAg), etc. For example, the lower electrodes LE1, LE2, LE3 correspond to anodes, and the upper electrodes UE1, UE2, UE3 correspond to cathodes.

[0032] The organic layers EL1, EL2, and EL3 each have a stacked structure of, for example, a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. The organic layers EL1, EL2, and EL3 may each have a so-called tandem structure including a plurality of light emitting layers.

[0033] The lower portion 14a of the auxiliary wiring 14 is formed of, for example, aluminum. The lower portion 14a may be formed of an aluminum alloy such as an aluminum-neodymium alloy (AlNd), an aluminum-yttrium alloy (AlY) or an aluminum-silicon alloy (AlSi), or may have a laminated structure of an aluminum layer and an aluminum alloy layer. Furthermore, the lower portion 14a may have a bottom layer formed of a metal material different from aluminum or an aluminum alloy under the aluminum layer or the aluminum alloy layer. As the metal material for forming such a bottom layer, for example, molybdenum (Mo), titanium nitride (TiN), a molybdenum-tungsten alloy (MoW) or a molybdenum-niobium alloy (MoNb) can be used.

[0034] The upper portion 14b of the auxiliary wiring 14 has a laminated structure of a lower layer formed of a metal material and an upper layer formed of a conductive oxide. The metal material forming the lower layer may be, for example, titanium, titanium nitride, molybdenum, tungsten, a molybdenum-tungsten alloy, or a molybdenum-niobium alloy. The conductive oxide forming the upper layer may be, for example, ITO or IZO. The upper portion 14b may have a single-layer structure of a metal material.

[0035] A common voltage is supplied to the auxiliary wiring 14. This common voltage is supplied to the upper electrodes UE1, UE2, and UE3 in contact with the side surfaces of the lower portion 14a. A pixel voltage is supplied to the lower electrodes LE1, LE2, and LE3 through the pixel circuits 1 included in the subpixels SP1, SP2, and SP3, respectively.

[0036] The organic layers EL1, EL2, and EL3 emit light in response to the application of a voltage. Specifically, when a potential difference is formed between the lower electrode LE1 and the upper electrode UE1, the light-emitting layer of the organic layer EL1 emits light in the red wavelength region. When a potential difference is formed between the lower electrode LE2 and the upper electrode UE2, the light-emitting layer of the organic layer EL2 emits light in the green wavelength region. When a potential difference is formed between the lower electrode LE3 and the upper electrode UE3, the light-emitting layer of the organic layer EL3 emits light in the blue wavelength region.

[0037] As another example, the light-emitting layers of the organic layers EL1, EL2, and EL3 may emit light of the same color (e.g., white). In this case, the display device DSP may include color filters that convert the light emitted by the light-emitting layers into light of the colors corresponding to the subpixels SP1, SP2, and SP3. The display device DSP may also include a layer including quantum dots that are excited by the light emitted by the light-emitting layers to generate light of the colors corresponding to the subpixels SP1, SP2, and SP3.

[0038] Fig. 3 is a diagram for explaining a process for forming the lower electrode LE1 shown in Fig. 2. Although a detailed description is omitted here, the lower electrodes LE2 and LE3 can also be formed by a similar process.

[0039] First, a first organic insulating layer 121 is formed on the circuit layer 11 (see FIG. 3(a)). Next, the first organic insulating layer 121 is patterned to form the recess 12a (see FIG. 3(b)). The recess 12a is formed, for example, at a position overlapping an element for electrically connecting the subpixel SP1 to the pixel circuit 1 (for example, one of the source electrode and the drain electrode of the driving transistor 3). Subsequently, the lower electrode LE1 is formed so as to cover the recess 12a formed in the first organic insulating layer 121 (see FIG. 3(c)). Thereafter, the second organic insulating layer 122 is formed so as to cover the first organic insulating layer 121 and the lower electrode LE1 (see FIG. 3(d)). Thereafter, the second organic insulating layer 122 is patterned so as to expose the upper surface of the lower electrode LE1, thereby forming the lower electrode LE1 embedded in the organic insulating layer 12 (see FIG. 3(e)). The upper surface of the lower electrode LE1 and the upper surface of the second organic insulating layer 122 (organic insulating layer 12) are, for example, flush with each other.

[0040] As described above, the organic insulating layer 12 has a structure in which two layers, the first organic insulating layer 121 and the second organic insulating layer 122, are laminated. The first organic insulating layer 121 and the second organic insulating layer 122 may be formed of the same organic insulating material, or may be formed of different organic insulating materials. As an example, this embodiment assumes that the first organic insulating layer 121 and the second organic insulating layer 122 are formed of the same organic insulating material.

[0041] Figures 4 to 6 are diagrams illustrating the process of forming display elements DE1, DE2, and DE3 of subpixels SP1, SP2, and SP3 shown in Figure 2. Figure 4 shows the process of forming display element DE1 of subpixel SP1, Figure 5 shows the process of forming display element DE2 of subpixel SP2, and Figure 6 shows the process of forming display element DE3 of subpixel SP3. Note that ribs 13 and auxiliary wiring 14 are omitted from illustration in Figures 4 to 6.

[0042] First, a circuit layer 11 is formed on a substrate 10. Then, a series of steps shown in Fig. 3 are performed to form an organic insulating layer 12 and lower electrodes LE1, LE2, and LE3 embedded in the organic insulating layer 12.

[0043] Here, to form the display element DE1 of the subpixel SP1, the organic layer EL1 and the upper electrode UE1 are evaporated over the display area DA, and the insulating film PAS1 is formed (deposited) by CVD (Chemical Vapor Deposition) (see FIG. 4(a)). Next, a resist R1 is placed in a region corresponding to the display element DE1 (see FIG. 4(b)). Thereafter, the organic layer EL1, the upper electrode UE1, and the insulating film PAS1 are removed by etching using the resist R1 as a mask, where the portions are exposed from the resist R1 (see FIG. 4(c)). Thereafter, the resist R1 is removed, and the display element DE1 is formed (see FIG. 4(d)).

[0044] Next, to form the display element DE2 of the subpixel SP2, the organic layer EL2 and the upper electrode UE2 are evaporated over the display area DA, and the insulating film PAS2 is formed (deposited) by CVD (see FIG. 5(a)). Next, a resist R2 is placed in a region corresponding to the display element DE2 (see FIG. 5(b)). Thereafter, the organic layer EL2, the upper electrode UE2, and the insulating film PAS2 are removed by etching using the resist R2 as a mask, whereby the portions of the organic layer EL2, the upper electrode UE2, and the insulating film PAS2 that are exposed from the resist R2 are removed (see FIG. 5(c)). Thereafter, the resist R2 is removed, and the display element DE2 is formed (see FIG. 5(d)).

[0045] Furthermore, to form the display element DE3 of the subpixel SP3, the organic layer EL3 and the upper electrode UE3 are evaporated over the display area DA, and the insulating film PAS3 is formed (deposited) by CVD (see FIG. 6(a)). Next, a resist R3 is placed in a region corresponding to the display element DE3 (see FIG. 6(b)). Thereafter, the organic layer EL3, the upper electrode UE3, and the insulating film PAS3 are etched using the resist R3 as a mask, and the portions thereof exposed from the resist R3 are removed (see FIG. 6(c)). Thereafter, the resist R3 is removed, and the display element DE3 is formed (see FIG. 6(d)).

[0046] In the following, the effect of the display device DSP (display panel PNL) according to the present embodiment will be described using a comparative example. Note that the comparative example is intended to explain some of the effects that the display device DSP (display panel PNL) according to the present embodiment can achieve, and does not exclude configurations and effects common to the present embodiment and the comparative example from the scope of the present invention.

[0047] 7 is a schematic cross-sectional view of a display panel PNL' provided in a display device according to a comparative example. The display panel PNL' according to the comparative example differs from the display panel PNL according to the present embodiment in that the lower electrode LE is disposed on an organic insulating layer 12 and that the peripheral edge of the lower electrode LE is covered with a rib 13.

[0048] In the display panel PNL' according to the comparative example, as described above, the lower electrode LE is disposed on the organic insulating layer 12. Therefore, as shown in FIG. 8, the thickness of the lower electrode LE cannot be completely absorbed by the rib 13, and a step due to the thickness of the lower electrode LE may occur in the rib 13. If a step occurs in the rib 13, the upper portion 14b of the auxiliary wiring 14 may be bent as shown in FIG. 8. If the upper portion 14b of the auxiliary wiring 14 is bent, the shadowing effect of the upper portion 14b cannot be obtained, and therefore, when the organic layer EL is evaporated, the organic layer EL may come into contact with the side surface of the lower portion 14a of the auxiliary wiring 14, which may cause a display defect. In addition, if the organic layer EL, the upper electrode UE, and the insulating film PAS are deposited on the bent upper portion 14b, these layers act as a load, causing the bent upper portion 14b to break, and the bent portion may adhere to, for example, the upper surface of the lower electrode LE, which may cause a display defect. Furthermore, if the upper portion 14b of the auxiliary wiring 14 is bent, the insulating film PAS will be divided in the middle, and there is a risk that the side surfaces of the upper electrode UE and the lower portion 14a of the auxiliary wiring 14 will not be covered.

[0049] 2, in the display panel PNL according to the present embodiment, the lower electrode LE is disposed in the recess 12a of the organic insulating layer 12 and embedded in the organic insulating layer 12, so that it is possible to prevent steps from being generated in the rib 13 due to the thickness of the lower electrode LE. This makes it possible to prevent display defects and deterioration in the reliability of the display device DSP as described above.

[0050] The following describes modified examples. (First Modification) The first modification example differs from the above-described embodiment in that, in order to reliably expose the upper surfaces of the lower electrodes LE1, LE2, and LE3 from the organic insulating layer 12, the organic insulating layer 12 is over-etched.

[0051] 9 is a schematic cross-sectional view of the display panel PNL1 according to the first modified example. As described above, the display panel PNL1 has a structure in which the organic insulating layer 12 is over-etched and the upper surfaces of the lower electrodes LE1, LE2, and LE3 protrude from the upper surface of the organic insulating layer 12.

[0052] In addition, the thickness T2 of the protruding portions of the lower electrodes LE1, LE2, and LE3 protruding from the upper surface of the organic insulating layer 12 is preferably 50% or less of the thickness T1 of the lower electrodes LE1, LE2, and LE3 (in other words, the amount of film reduction due to over-etching is preferably 50% or less of the thickness of the lower electrodes LE1, LE2, and LE3). This makes it possible to prevent steps from being generated in the rib 13 due to the protruding portions of the lower electrodes LE1, LE2, and LE3.

[0053] As a method for over-etching the organic insulating layer 12, for example, when the organic insulating layer 12 is formed of a photosensitive organic insulating material, the organic insulating layer 12 may be patterned to expose the upper surfaces of the lower electrodes LE1, LE2, and LE3, and then the organic insulating layer 12 may be over-etched by performing oxygen plasma treatment or argon plasma treatment.

[0054] Alternatively, when the organic insulating layer 12 is formed of a non-photosensitive organic insulating material, the organic insulating layer 12 may be over-etched by strengthening the etching conditions when patterning the organic insulating layer 12 or by extending the etching time.

[0055] 9 shows a structure that is realized when over-etching is performed on the organic insulating layer 12 that is formed with a flat entire surface, but in order to reliably expose the upper surfaces of the lower electrodes LE1, LE2, LE3, the organic insulating layer 12 may be formed thinner in the regions that overlap with the upper surfaces of the lower electrodes LE1, LE2, LE3 than in other regions. When over-etching is performed on the organic insulating layer 12 in this state, a structure is realized in which the thickness of the organic insulating layer 12 differs between the regions that overlap with the upper surfaces of the lower electrodes LE1, LE2, LE3 and the other regions, as shown in FIG.

[0056] In the structure according to the first modified example, the lower electrode LE is still embedded in the organic insulating layer 12, so that it is possible to prevent steps from occurring in the rib 13 due to the thickness of the lower electrode LE.

[0057] (Second Modification) The second modified example differs from the above-described embodiment in the process of forming the lower electrodes LE1, LE2, LE3 embedded in the organic insulating layer 12. Specifically, in the above-described embodiment, as shown in Fig. 3, the lower electrodes LE1, LE2, LE3 embedded in the organic insulating layer 12 are formed in the order of "first organic insulating layer 121, lower electrodes LE1, LE2, LE3, second organic insulating layer 122", but in this modified example, the lower electrodes LE1, LE2, LE3 embedded in the organic insulating layer 12 are formed in the order of "first organic insulating layer 121, second organic insulating layer 122, lower electrodes LE1, LE2, LE3".

[0058] 11 and 12 are schematic cross-sectional views of a display panel PNL2 according to a second modified example. The display panel PNL2 has a first recess 12A formed in a first organic insulating layer 121 constituting the organic insulating layer 12, and a second recess 12B formed in a second organic insulating layer 122 constituting the organic insulating layer 12. It is desirable that the second recess 12B overlaps with the first recess 12A in a plan view and is larger than the first recess 12A. In other words, it is desirable that the first recess 12A is surrounded by the second recess 12B in a plan view.

[0059] 11, the display panel PNL2 according to the second modification may have a structure in which the peripheral portions of the lower electrodes LE1, LE2, and LE3 arranged in the first recess 12A and the second recess 12B run up onto the second organic insulating layer 122. The width W1 of the portion of the lower electrodes LE1, LE2, and LE3 that runs up onto the second organic insulating layer 122 (hereinafter, referred to as the overlapping portion PT1) is preferably about 10% of the length between the end of the overlapping portion PT1 and the end of the overlapping portion PT1 of the lower electrode LE constituting the adjacent subpixel SP (in other words, the width W2 of the exposed portion of the second organic insulating layer 122). This can prevent the occurrence of a step in the rib 13 due to the overlapping portion PT1 of the lower electrodes LE1, LE2, and LE3.

[0060] Alternatively, the display panel PNL2 according to the second modification may have a structure in which a gap PT2 is provided between the periphery of the lower electrodes LE1, LE2, and LE3 arranged in the first recess 12A and the second recess 12B and the side of the second recess 12B, as shown in FIG. 12. In other words, the periphery of the lower electrodes LE1, LE2, and LE3 arranged in the first recess 12A and the second recess 12B may have a structure in which they are spaced apart from the side of the second recess 12B. Note that the width W3 of the gap PT2 described above is preferably about 10 μm. This allows the gap PT2 to be filled (buried) with the rib 13 arranged on the organic insulating layer 12.

[0061] In the structure according to the second modified example, the lower electrode LE is still embedded in the organic insulating layer 12, so that it is possible to prevent steps from occurring in the rib 13 due to the thickness of the lower electrode LE.

[0062] According to the embodiment described above, it is possible to provide a display device capable of suppressing a decrease in reliability.

[0063] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0064] DSP...display device, PNL...display panel, DE1, DE2, DE3...display element, 10...substrate, 11...circuit layer, 12...organic insulating layer, 12a...recess, 121...first organic insulating layer, 122...second organic insulating layer, 13...rib, 14...auxiliary wiring, 14a...lower part, 14b...upper part, LE1, LE2, LE3...lower electrode, AP1, AP2, AP3...pixel opening, EL1, EL2, EL3...organic layer, UE1, UE2, UE3...upper electrode, PAS1, PAS2, PAS3...insulating film.

Claims

1. A substrate; an organic insulating layer disposed on the substrate and having a recess; a lower electrode disposed in the recess and embedded in the organic insulating layer; a rib having a pixel opening overlapping the lower electrode; an auxiliary wiring including a conductive lower portion disposed on the rib and an upper portion having an end portion protruding from a side surface of the lower portion; an upper electrode facing the lower electrode and connected to the auxiliary wiring; an organic layer disposed between the lower electrode and the upper electrode, the organic layer emitting light in response to a potential difference between the lower electrode and the upper electrode; Equipped with an upper surface of the lower electrode is exposed from the organic insulating layer in the pixel opening and is in contact with the organic layer; Display device.

2. An upper surface of the lower electrode and an upper surface of the organic insulating layer are flush with each other. The display device according to claim 1 .

3. the lower electrode has a protruding portion protruding in a thickness direction from an upper surface of the organic insulating layer, The thickness of the protrusion is half or less than the thickness of the lower electrode. The display device according to claim 1 .

4. a peripheral portion of the lower electrode disposed on the organic insulating layer; The display device according to claim 1 .

5. The peripheral portion of the lower electrode is spaced from the side surface of the recess. The display device according to claim 1 .

6. A substrate; a first organic insulating layer disposed on the substrate; a second organic insulating layer disposed on the first organic insulating layer; a lower electrode embedded in the first organic insulating layer and the second organic insulating layer; a rib having a pixel opening overlapping the lower electrode; an auxiliary wiring including a conductive lower portion disposed on the rib and an upper portion having an end portion protruding from a side surface of the lower portion; an upper electrode facing the lower electrode and connected to the auxiliary wiring; an organic layer disposed between the lower electrode and the upper electrode, the organic layer emitting light in response to a potential difference between the lower electrode and the upper electrode; Equipped with an upper surface of the lower electrode is exposed from the second organic insulating layer in the pixel opening and is in contact with the organic layer; Display device.

7. An upper surface of the lower electrode and an upper surface of the second organic insulating layer are flush with each other. The display device according to claim 6.

8. the lower electrode has a protruding portion protruding in a thickness direction from an upper surface of the second organic insulating layer, The thickness of the protrusion is half or less than the thickness of the lower electrode. The display device according to claim 6.

9. the first organic insulating layer has a first recess; the second organic insulating layer has a second recess that overlaps the first recess in a plan view and is larger than the first recess; the lower electrode is disposed in the first recess and the second recess; The display device according to claim 6.

10. a peripheral portion of the lower electrode is disposed on the second organic insulating layer; The display device according to claim 9.

11. The peripheral portion of the lower electrode is spaced from the side surface of the second recess. The display device according to claim 9.

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