Patent Publication Number: US-2023141982-A1

Title: Display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/899,789 filed on Jun. 12, 2020, which claims priority under 35 USC § 119 to Korean Patent Application No. 10-2019-0114783 filed on Sep. 18, 2019 in the Korean Intellectual Property Office (KIPO), the disclosures of which are incorporated by reference herein in their entireties. 
    
    
     TECHNICAL FIELD 
     Exemplary embodiments of the present inventive concept relate generally to a display apparatus. More particularly, exemplary embodiments of the present inventive concept relate to a display apparatus having a connection electrode. 
     DISCUSSION OF THE RELATED ART 
     As the technology improves, display products having smaller sizes, lighter weights, and superior performance are being produced. Conventional cathode ray tube (CRT) televisions have been widely used for display apparatuses because of their performance and price. Recently, however, a display apparatus such as a plasma display apparatus, a liquid crystal display apparatus, and an organic light emitting diode display apparatus have been increasingly used because, when compared to a CRT, these display apparatuses provide increased miniaturization or portability, are light in weight, and have relatively low power consumption. 
     The organic light emitting diode display apparatus typically includes a substrate, a plurality of wirings disposed on the substrate, and a light emitting structure disposed on the wirings. 
     SUMMARY 
     According to an exemplary embodiment of the present inventive concept, a display apparatus includes: a base substrate; a thin film transistor disposed on the base substrate and including an active pattern; an insulating layer disposed on the active pattern of the thin film transistor; a connection electrode disposed on the insulating layer, and electrically connected to the thin film transistor, wherein the connection electrode includes a curved wiring portion; a first via insulating layer covering the connection electrode; a first electrode disposed on the first via insulating layer; a light emitting layer disposed on the first electrode and at least partially overlapping the connection electrode; and a second electrode disposed on the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the display apparatus further includes: a plurality of data lines arranged along a first direction, wherein each of the data lines extend in a second direction crossing the first direction, wherein the connection electrode includes a first contact portion, a second contact portion spaced apart from the first contact portion in the second direction, and the curved wiring portion which connects the first contact portion to the second contact portion. 
     In an exemplary embodiment of the present inventive concept, a data line, of the plurality of data lines, adjacent to the connection electrode includes a straight line portion and a curved line portion connected to the straight line portion, wherein the curved line portion is adjacent to the curved wiring portion of the connection electrode. 
     In an exemplary embodiment of the present inventive concept, the light emitting layer includes a blue light emitting layer configured to emit blue light. 
     In an exemplary embodiment of the present inventive concept, the display apparatus further includes: a red light emitting layer spaced apart from the blue light emitting layer and configured to emit red light; and a green light emitting layer spaced apart from the blue light emitting layer and the red light emitting layer and configured to emit green light, wherein a thickness of the blue light emitting layer is smaller than a thickness of each of the red and green light emitting layers. 
     In an exemplary embodiment of the present inventive concept, the display apparatus further includes: a plurality of power lines arranged along a first direction, wherein each of the power lines extend in a second direction crossing the first direction, wherein the connection electrode includes a first contact portion, a second contact portion spaced apart from the first contact portion in the second direction, and the curved wiring portion which connects the first contact portion to the second contact portion, and wherein a power line, of the plurality of power lines, adjacent to the connection electrode includes a straight line portion and a curved line portion connected to the straight line portion, wherein the curved line portion is adjacent to the curved wiring portion of the connection electrode. 
     In an exemplary embodiment of the present inventive concept, the connection electrode includes a first contact portion, a second contact portion spaced apart from the first contact portion, and the curved wiring portion connecting the first contact portion to the second contact portion, and wherein the curved wiring portion has an annular shape. 
     In an exemplary embodiment of the present inventive concept, the curved wiring portion overlaps the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the connection electrode includes a first contact portion, a second contact portion spaced apart from the first contact portion, and the curved wiring portion connecting the first contact portion to the second contact portion, and wherein the curved wiring portion has a curved shape. 
     In an exemplary embodiment of the present inventive concept, the display apparatus further includes: source and drain electrodes disposed between the base substrate and the connection electrode; and a second via insulating layer disposed between the source and drain electrodes and the connection electrode, wherein the connection electrode is electrically connected to the drain electrode through a contact hole formed through the second via insulating layer. 
     In an exemplary embodiment of the present inventive concept, the connection electrode includes a contact portion and the curved wiring portion connected to the contact portion, and wherein the contact portion of the connection electrode is electrically connected to the first electrode through a contact hole formed through the first via insulating layer. 
     In an exemplary embodiment of the present inventive concept, the curved wiring portion of the connection electrode has an annular shape, and wherein the curved wiring portion overlaps the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the curved wiring portion of the connection electrode has a curved shape, and wherein the curved wiring portion overlaps the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the connection electrode includes a first contact portion, a second contact portion spaced apart from the first contact portion, and the curved wiring portion which connects the first contact portion to the second contact portion, and wherein each of the first contact portion and the second contact portion is electrically connected to a conductive pattern of another layer through a contact hole formed through the second via insulating layer. 
     In an exemplary embodiment of the present inventive concept, a concavo-convex portion corresponding to the connection electrode is formed on a top surface of the first via insulating layer. 
     In an exemplary embodiment of the present inventive concept, a concavo-convex portion corresponding to the concavo-convex portion of the first via insulating layer is formed on a top surface of the first electrode. 
     According to an exemplary embodiment of the present inventive concept, a display apparatus includes: a base substrate; a thin film transistor disposed on the base substrate and including an active pattern; an insulating layer disposed on the active pattern of the thin film transistor; a connection electrode disposed on the insulating layer, and electrically connected to the thin film transistor, wherein the connection electrode includes a dummy portion including a horizontal portion extending in a first direction; a via insulating layer covering the connection electrode; a first electrode disposed on the via insulating layer; a light emitting layer disposed on the first electrode and overlapping the dummy portion of the connection electrode; and a second electrode disposed on the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the dummy portion further includes a vertical portion extending in a second direction substantially perpendicular to the first direction. 
     In an exemplary embodiment of the present inventive concept, the connection electrode further includes a first contact portion, a second contact portion spaced apart from the first contact portion in a second direction, and a connection wiring portion connecting the first contact portion to the second contact portion, and wherein the dummy portion extends from the first contact portion, the second contact portion, or the connection wiring portion, and wherein the dummy portion overlaps the light emitting layer. 
     In an exemplary embodiment of the present inventive concept, the light emitting layer is a blue light emitting layer configured to emit blue light, wherein the display apparatus further includes: a red light emitting layer spaced apart from the blue light emitting layer and configured to emit red light; and a green light emitting layer spaced apart from the blue light emitting layer and the red light emitting layer and configured to emit green light, and wherein a thickness of the blue light emitting layer is smaller than a thickness of each of the red and green light emitting layers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features of the present inventive concept will become more apparent by describing in detailed exemplary embodiments thereof with reference to the accompanying drawings, in which: 
         FIG.  1    is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG.  2    is a circuit diagram illustrating an example of a pixel included in the display apparatus of  FIG.  1   ; 
         FIG.  3    is a cross-sectional diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG.  4    is a plan diagram illustrating a source-drain conductive layer, a pixel electrode, and a light emitting layer of the display apparatus of  FIG.  3   ; 
         FIGS.  5 A,  5 B,  5 C and  5 D  are plan diagrams illustrating various examples of connection electrodes of a display apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG.  6    is a cross-sectional diagram of a display apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG.  7    is a plan diagram illustrating an electrode, a pixel electrode, and a light emitting layer of the display apparatus of  FIG.  6   ; 
         FIG.  8    is a block diagram illustrating an electronic apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG.  9 A  is a diagram illustrating an example in which the electronic apparatus of  FIG.  8    is implemented as a television; and 
         FIG.  9 B  is a diagram illustrating an example in which the electronic apparatus of  FIG.  8    is implemented as a smart phone. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, exemplary embodiments of the present inventive concept will be explained in detail with reference to the accompanying drawings. 
       FIG.  1    is a block diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept. 
     Referring to  FIG.  1   , the display apparatus may include a display panel  10 , a scan driver  20 , a data driver  30 , an emission control driver  40 , and a controller  50 . 
     The display panel  10  may include a plurality of pixels PX for displaying an image. For example, the display panel  10  may include n×m pixels PX located at intersecting portions between scan lines SL 1  to SLn and data lines DL 1  to DLm (e.g., where n and m are integers greater than 1, respectively). The structure of the pixel PX will be described in detail with reference to  FIG.  2   . 
     The scan driver  20  may sequentially provide a first scan signal to the pixels PX through the scan lines SL 1  to SLn, and may sequentially provide a second scan signal to the pixels PX through inverted scan lines /SL 1  to /SLn based on a first control signal CTL 1 . For example, the second scan signal may be an inverted signal of the first scan signal. 
     The data driver  30  may provide a data signal to the pixels PX through the data lines DL 1  to DLm based on a second control signal CTL 2 . 
     The emission control driver  40  may sequentially provide an emission control signal to the pixels PX through emission control lines EMI to EMn based on a third control signal CTL 3 . 
     The controller  50  may control the scan driver  20 , the data driver  30 , and the emission control driver  40 . The controller  50  may generate the control signals CTL 1  to CTL 3  to control the scan driver  20 , the data driver  30 , and the emission control driver  40 , respectively. For example, the first control signal CTL 1  for controlling the scan driver  20  may include a scan start signal, a scan clock signal, and the like. For example, the second control signal CTL 2  for controlling the data driver  30  may include image data, a horizontal start signal, and the like. For example, the third control signal CTL 3  for controlling the emission control driver  40  may include an emission control start signal, an emission control clock signal, and the like. 
     In addition, the display apparatus may further include a power supply unit configured to supply a first power supply voltage ELVDD, a second power supply voltage ELVSS, and an initialization voltage VINT to the display panel  10 . 
       FIG.  2    is a circuit diagram illustrating an example of a pixel included in the display apparatus of  FIG.  1   . 
     Referring to  FIG.  2   , the pixel PX may include first to seventh transistors T 1  to T 7 , a storage capacitor CST, and an organic light emitting diode OLED. The pixel PX may be located in an i th  pixel row (e.g., where i is an integer between 1 and n) and a j th  pixel column (e.g., where j is an integer between 1 and m). 
     The first transistor T 1  may be a driving transistor configured to provide a driving current, which corresponds to the received data signal, to the organic light emitting diode OLED. The first transistor T 1  may include a gate electrode connected to a first node N 1 , a first electrode connected to a second node N 2 , and a second electrode connected to a third node N 3 . 
     The second transistor T 2  may provide the data signal to the first transistor T 1  in response to a first scan signal GS 1 . In an exemplary embodiment of the present inventive concept, the second transistor T 2  may include a gate electrode configured to receive the first scan signal GS 1  from an i th  scan line SLi, a first electrode configured to receive the data signal from a j th  data line DLj, and a second electrode connected to the first electrode of the first transistor T 1 . For example, the second electrode of the second transistor T 2  may be connected to the second node N 2 . 
     The third transistor T 3  may connect the second electrode of the first transistor T 1  to the gate electrode of the first transistor T 1  in response to a second scan signal GS 2 . In an exemplary embodiment of the present inventive concept, the third transistor T 3  may include a gate electrode configured to receive the second scan signal GS 2  from an i th  inverted scan line /SLi, a first electrode connected to the second electrode of the first transistor T 1 , and a second electrode connected to the gate electrode of the first transistor T 1 . For example, the first electrode of the third transistor T 3  may be connected to the third node N 3 . For example, the second electrode of the third transistor T 3  may be connected to the first node N 1 . 
     The fourth transistor T 4  may apply the initialization voltage VINT to the gate electrode of the first transistor T 1  in response to a third scan signal GS 3 . In an exemplary embodiment of the present inventive concept, the fourth transistor T 4  may include a gate electrode, a first electrode connected to the initialization voltage VINT, and a second electrode connected to the gate electrode of the first transistor T 1  at the first node N 1 . The gate electrode of the fourth transistor T 4  is configured to receive the third scan signal GS 3  from an (i−1) th  inverted scan line /SL(i−1). 
     The fifth transistor T 5  may apply the first power supply voltage ELVDD to the first electrode of the first transistor T 1  in response to the emission control signal. In an exemplary embodiment of the present inventive concept, the fifth transistor T 5  may include a gate electrode, a first electrode connected to the first power supply voltage ELVDD, and a second electrode connected to the first electrode of the first transistor T 1  at the second node N 2 . The gate electrode of the fifth transistor T 5  is configured to receive the emission control signal from an i th  emission control line Emi. 
     The sixth transistor T 6  may connect the second electrode of the first transistor T 1  to a first electrode of the organic light emitting diode OLED in response to the emission control signal. In an exemplary embodiment of the present inventive concept, the sixth transistor T 6  may include a gate electrode, a first electrode connected to the second electrode of the first transistor T 1  at the second node N 2 , and a second electrode connected to the first electrode of the organic light emitting diode OLED at a fourth node N 4 . The gate electrode of the sixth transistor T 6  is configured to receive the emission control signal from the i 1 ′ emission control line Emi. 
     The seventh transistor T 7  may apply the initialization voltage VINT to the first electrode of the organic light emitting diode OLED in response to a fourth scan signal GS 4 . In an exemplary embodiment of the preset inventive concept, the seventh transistor T 7  may include a gate electrode, a first electrode connected to the initialization voltage VINT, and a second electrode connected to the first electrode of the organic light emitting diode OLED (i.e., the fourth node N 4 ). The gate electrode of the seventh transistor T 7  is configured to receive the fourth scan signal GS 4  from the (i−1) th  inverted scan line/SL(i−1) 
     The storage capacitor CST may include a first electrode connected to the first power supply voltage ELVDD and a second electrode connected to the gate electrode of the first transistor T 1  at the first node N 1 . 
       FIG.  3    is a cross-sectional diagram illustrating a display apparatus according to an exemplary embodiment of the present inventive concept. 
     Referring to  FIG.  3   , the display apparatus may include a base substrate  100 , a buffer layer  110 , an active pattern ACT, a first insulating layer  120 , a gate conductive layer, a second insulating layer  130 , a source-drain conductive layer, a via insulating layer VIA, a pixel defining layer PDL, a light emitting structure  180 , and a thin film encapsulation layer TFE. 
     The base substrate  100  may be formed of a transparent or opaque material. For example, the base substrate  100  may include a quartz substrate, a synthetic quartz substrate, a calcium fluoride substrate, a fluorine-doped quartz substrate (e.g., an F-doped quartz substrate), a soda lime glass substrate, a non-alkali glass substrate, and the like. In an exemplary embodiment of the present inventive concept, the base substrate  100  may be a transparent resin substrate having flexibility. Examples of the transparent resin substrate that may be used as the base substrate  100  include a polyimide substrate. 
     The buffer layer  110  may be disposed on the base substrate  100 . The buffer layer  110  may prevent metal atoms or impurities from diffusing from the base substrate  100  into the active pattern ACT, and may control a heat transfer rate during a crystallization process for forming the active pattern ACT to obtain a substantially uniform active pattern ACT. In addition, when a surface of the base substrate  100  is not uniform, the buffer layer  110  may serve to increase flatness of the surface of the base substrate  100 . For example, the buffer layer  110  may planarize an upper surface of the base substrate  100 . 
     The active pattern ACT of a thin film transistor TFT may be disposed on the buffer layer  110 . For example, the active pattern ACT may include poly crystal silicon. The active pattern ACT may include a drain region D and a source region S which are doped with impurities, and a channel region C disposed between the drain region and the source region. For example, the poly crystal silicon may be formed by depositing amorphous silicon and crystallizing the amorphous silicon. In an exemplary embodiment of the present inventive concept, the active pattern ACT may include an oxide semiconductor. For example, the oxide semiconductor may be a semiconductor oxide layer including a binary compound (AB), a ternary compound (AB x C y ), a quaternary compound (AB x C y D z ), and the like including tin (Sn), indium (In), zinc (Zn), gallium (Ga), titanium (Ti), aluminum (Al), hafnium (Hf), zirconium (Zr), magnesium (Mg), and the like. 
     The first insulating layer  120  may be disposed on the active pattern ACT. For example, the first insulating layer  120  may be disposed along a profile of the active pattern ACT with a substantially uniform thickness to cover the active pattern ACT on the buffer layer  110 . In addition, the first insulating layer  120  may cover the active pattern ACT on the buffer layer  110 , and may have a substantially flat top surface without creating a step around the active pattern ACT. The first insulating layer  120  may include an inorganic insulating material such as a silicon compound and metal oxide. 
     The gate conductive layer may be disposed on the first insulating layer  120 . The gate conductive layer may include a gate electrode GE of the thin film transistor TFT. The gate conductive layer may be formed by using a metal, an alloy, metal nitride, conductive metal oxide, a transparent conductive material, and the like. 
     The second insulating layer  130  may cover the gate conductive layer on the first insulating layer  120 , and may have a substantially flat top surface without creating a step around the gate conductive layer. In addition, the second insulating layer  130  may be disposed along a profile of the gate conductive layer with a substantially uniform thickness to cover the gate conductive layer on the first insulating layer  120 . The second insulating layer  130  may include an inorganic insulating material such as a silicon compound and metal oxide. 
     The source-drain conductive layer may be disposed on the second insulating layer  130 . The source-drain conductive layer may include a connection electrode CE and a contact pad CP. The source-drain conductive layer may further include a signal wiring and a voltage wiring such as a data line (see, e.g., DL of  FIG.  4   ) and a power line (see, e.g., PL of  FIG.  4   ). The source-drain conductive layer may be formed by using a metal, an alloy, metal nitride, conductive metal oxide, a transparent conductive material, and the like. The connection electrode CE and the contact pad CP may each respectively contact the source region S and the drain region D through respective contact holes formed in the first insulating layer  120  and the second insulating layer  130 . 
     The via insulating layer VIA may be disposed on the source-drain conductive layer. The via insulating layer VIA may have a single-layer structure, and may also have a multilayer structure including at least two insulating films. The via insulating layer VIA may be formed by using an organic material such as a photoresist, an acryl-based resin, a polyimide-based resin, a polyamide-based resin, and a siloxane-based resin. 
     The light emitting structure  180  may include a first electrode  181 , a light emitting layer  182 , and a second electrode  183 . 
     The first electrode  181  may be disposed on the via insulating layer VIA. In addition, the first electrode  181  may be connected to the contact pad CP through a contact hole formed in the via insulating layer VIA. Depending on a light emitting scheme of the display apparatus, the first electrode  181  may be formed by using, for example, a reflective material or a transmissive material. In exemplary embodiment of the present inventive concept, the first electrode  181  may have a single-layer structure or a multilayer structure including, for example, a metal film, an alloy film, a metal nitride film, a conductive metal oxide film, and/or a transparent conductive material film. 
     The pixel defining layer PDL may be disposed on the via insulating layer VIA on which the first electrode  181  is disposed. The pixel defining layer PDL may be formed by using an organic material, an inorganic material, and the like. For example, the pixel defining layer PDL may be formed by using a photoresist, a polyacryl-based resin, a polyimide-based resin, an acryl-based resin, a silicon compound, and the like. In an exemplary embodiment of the present inventive concept, the pixel defining layer PDL may be etched to form an opening which partially exposes the first electrode  181 . An emission area and a non-emission area of the display apparatus may be formed by the opening of the pixel defining layer PDL. For example, the opening of the pixel defining layer PDL may correspond to the emission area, and the non-emission area may correspond to a portion of the pixel defining layer PDL adjacent to the opening of the pixel defining layer PDL. 
     The light emitting layer  182  may be disposed on the first electrode  181  exposed through the opening of the pixel defining layer PDL. For example, the light emitting layer  182  may be disposed in the opening of the pixel defining layer PDL. In addition, the light emitting layer  182  may extend onto a side wall of the opening of the pixel defining layer PDL. In an exemplary embodiment of the present inventive concept, the light emitting layer  182  may have a multilayer structure including an organic light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like. In an exemplary embodiment of the present inventive concept, except for the organic light emitting layer, the hole injection layer, the hole transport layer, the electron transport layer, the electron injection layer, and the like may be commonly formed to correspond to the plurality of pixels. The organic light emitting layer of the light emitting layer  182  may be formed by using light emitting materials for generating different color lights such as red light, green light, and blue light according to each pixel of the display apparatus (see, e.g.,  182   a ,  182   b , and  182   c  of  FIG.  4   ). 
     The second electrode  183  may be disposed on the pixel defining layer PDL and the light emitting layer  182 . Depending on a light emitting scheme of the display apparatus, the second electrode  183  may include a transmissive material or a reflective material. In an exemplary embodiment of the present inventive concept, the second electrode  183  may have a single-layer structure or a multilayer structure including, for example, a metal film, an alloy film, a metal nitride film, a conductive metal oxide film, and/or a transparent conductive material film. 
     The thin film encapsulation layer TFE may be disposed on the second electrode  183 . The thin film encapsulation layer TFE may prevent moisture and oxygen from penetrating the display apparatus from an outside. The thin film encapsulation layer TFE may include at least one organic layer and at least one inorganic layer. The at least one organic layer and the at least one inorganic layer may be alternately stacked on each other. For example, the thin film encapsulation layer TFE may include two inorganic layers and one organic layer disposed therebetween, but the present inventive concept is not limited thereto. In an exemplary embodiment of the present inventive concept, a sealing substrate may be provided instead of the thin film encapsulation layer to block external air and moisture from penetrating into the display apparatus. 
       FIG.  4    is a plan diagram illustrating a source-drain conductive layer, a pixel electrode, and a light emitting layer of the display apparatus of  FIG.  3   . In  FIG.  4   , the plan view shows an area corresponding to one red sub-pixel (see  182   a ), one blue sub-pixel (see  182   c ), and four green sub-pixels (see  182   b ). 
     Referring to  FIGS.  3  and  4   , the source-drain conductive layer may include a data line DL, a power line PL, a contact pad CP, and a connection electrode CE. 
     The data line DL may extend in a second direction D 2 . The data line DL may have a substantially straight line shape. In addition, the data line DL may include a curved line portion DLb and a straight line portion DLa connected to the curved line portion DLb. In addition, the data line DL is adjacent to the light emitting layer  182   c  which is the emission area. For example, the connection between the straight line portion DLa and the curved line portion DLb is adjacent to the light emitting layer  182   c.    
     The power line PL may extend in the second direction D 2  while being spaced apart from the first data line DL in a first direction D 1 . In addition, the power line PL may include a curved line portion PLb and a straight line portion PLa connected to the curved line portion PLb. In addition, the power line PL is adjacent to the light emitting layer  182   c  which is the emission area. For example, the connection between the straight line portion PLa and the curved line portion PLb is adjacent to the light emitting layer  182   c.    
     The above configuration is to prevent the connection electrode CE from being adjacent to the data line DL or the power line PL without a design margin when the connection electrode CE has annular shape or the like with a size increased in the first direction D 1  substantially perpendicular to the second direction D 2 . 
     The red sub-pixel may include a first electrode  181   a , a red light emitting layer  182   a , and a second electrode  183   a . The green sub-pixel may include a first electrode  181   b , a green light emitting layer  182   b , and a second electrode  183   b . The blue sub-pixel may include a first electrode  181   c , a blue light emitting layer  182   c , and a second electrode  183   c.    
     In the blue sub-pixel, the contact pad CP may be electrically connected to the first electrode  181   c  through a contact hole formed through the via insulating layer VIA (see, e.g.,  FIG.  3   ). The contact pad CP may not overlap the blue light emitting layer  182   c  disposed in the opening of the pixel defining layer PDL. 
     In addition, in the red sub-pixel or the green sub-pixel, contact pads CP corresponding to the respective pixels may be electrically connected to the first electrodes  181   a  and  181   b  through contact holes formed through the via insulating layer VIA, respectively. The contact pads may not overlap the red light emitting layer  182   a  and the green light emitting layer  182   b.    
     The connection electrode CE may overlap the blue light emitting layer  182   c . The connection electrode CE may include a first contact portion, a second contact portion spaced apart from the first contact portion in the second direction D 2 , and a curved wiring portion which connects the first contact portion to the second contact portion. The configuration will be described in detail below with reference to  FIGS.  5 C and  5 D . 
     The connection electrode CE may be formed to correspond to each of the sub-pixels, and a connection electrode CE which overlaps the blue light emitting layer  182   c  may include a curved wiring portion. Accordingly, a concavo-convex portion corresponding to the connection electrode CE may be formed on a top surface of the via insulating layer VIA (see, e.g., the top surface of the via insulating layer VIA of  FIG.  3   ). For example, the top surface of the via insulating layer VIA may be uneven and include protrusions and indentations. Since the via insulating layer VIA is not completely planarized, the via insulating layer VIA may have an inclined portion (e.g., concavo-convex portion) along the connection electrode CE which is a wiring disposed under the via insulating layer VIA, and a concavo-convex portion corresponding to the concavo-convex portion of the via insulating layer VIA may be formed on a top surface of the first electrode  181   c  (see, e.g., the top surface of  181  of  FIG.  3   ). 
     For example, the connection electrode CE is a portion of the source-drain conductive layer, and the source-drain conductive layer generally extends in the second direction D 2 , in which a white angular difference (WAD) may vary according to an azimuth angle. For example, a deviation of the WAD may occur when the display apparatus is viewed obliquely from a left or right side of the display apparatus and when the display apparatus is viewed obliquely from an upper or lower side of the display apparatus. 
     According to the present embodiment, the connection electrode CE includes the curved wiring portion, so that the concavo-convex portion may be formed in a curved line. Accordingly, WAD distribution may be improved, and variations of luminance and color coordinates according to an azimuth angle may be reduced. 
     Here, the WAD is a factor for evaluating a variation of white light emission characteristics according to an observation angle with respect to an organic light emitting diode display apparatus, and is an index for checking a degree of improvement of a wide viewing angle. For example, referring to the WAD, compared to a case in which the shape structure of the connection electrode according to an exemplary embodiment of the present inventive concept is not applied, a luminance variation and a color coordinate variation according to a variation of the observation angle on the basis of a front side which is perpendicular to a screen of the display apparatus may be reduced, so that display quality may be increased. 
     Here, as a WAD improvement rate becomes high, there is no great difference in the luminance variation and the color coordinate variation when obliquely viewing the display apparatus from a side of the display apparatus as compared with a case where the display apparatus is viewed from the front side of the display apparatus. 
     In addition, due to the concavo-convex portion formed on the top surface of the first electrode by the curved wiring portion of the connection electrode CE, variations of luminance and color coordinates according to the azimuth angle may be reduced. In other words, when the display apparatus is viewed obliquely in various directions such as up, down, left, and right directions, the luminance variation and the color coordinate variation according to a variation of an observation azimuth angle may be reduced, so that the display quality may be increased. 
     In addition, a thickness of the blue light emitting layer  182   c  may be smaller than a thickness of each of the red light emitting layer  182   a  and the green light emitting layer  182   b . For example, the thickness of the green light emitting layer  182   b  may be greater than the thickness of the blue light emitting layer  182   c , and the thickness of the red light emitting layer  182   a  may be greater than the thickness of the green light emitting layer  182   b . Therefore, the blue light emitting layer  182   c  having the smallest thickness may have a large WAD or a large deviation according to an azimuth angle due to the concavo-convex portion formed on the top surface of the first electrode, and the WAD or the deviation according to the azimuth angle from being increased due to the curved wiring portion of the connection electrode CE. 
       FIGS.  5 A,  5 B,  5 C and  5 D  are plan diagrams illustrating various examples of connection electrodes of a display apparatus according to an exemplary embodiment of the present inventive concept. 
     Referring to  FIG.  5 A , the connection electrode CE may include: a first contact portion CT 1 ; a second contact portion CT 2  spaced apart from the first contact portion CT 1  in the second direction D 2 ; a connection wiring portion CL which connects the first contact portion CT 1  to the second contact portion CT 2 ; and a dummy portion including a horizontal portion DMa extending in the first direction D 1  and connected to the second contact portion CT 2 , and a vertical portion DMb extending in the second direction D 2  and connected to the horizontal portion DMa. The dummy portion may overlap the light emitting layer  182   c . For example, the light emitting layer  182   c  may completely overlap the dummy portion. 
     Similar to the curved wiring portion described in  FIG.  4   , the dummy portion may form an inclined portion (concavo-convex portion) on the top surface of the first electrode. Accordingly, the WAD and deviations in luminance and color coordinates according to an azimuth angle may be improved. 
     Referring to  FIG.  5 B , the connection electrode CE may include: a first contact portion CT 1 ; a second contact portion CT 2  spaced apart from the first contact portion CT 1  in the second direction D 2 ; a connection wiring portion CL which connects the first contact portion CT 1  to the second contact portion CT 2 ; and a dummy portion including a first horizontal portion DMa 1  and a second horizontal portion DMa 2  extending left and right in the first direction D 1  from the connection wiring portion CL, respectively. The dummy portion may be electrically connected to the first contact portion CT 1 , the second contact portion CT 2 , and the connection portion CL of the connection electrode CE, and may have various shapes in addition to the shapes illustrated in  FIGS.  5 A and  5 B . For example, the dummy portion may have a curved line shape as well as a straight line shape. 
     Referring to  FIG.  5 C , the connection electrode CE may include a first contact portion CT 1 , a second contact portion CT 2  spaced apart from the first contact portion CT 1  in the second direction D 2 , and a first curved wiring portion CL 1  and a second curved wiring portion CL 2  which connect the first contact portion CT 1  to the second contact portion CT 2 . The first curved wiring portion CL 1  and the second curved wiring portion CL 2  may have annular shape. The first curved wiring portion CL 1  and the second curved wiring portion CL 2  having the annular shape may overlap the light emitting layer  182   c . For example, the first curved wiring portion CL 1  and the second curved wiring portion CL 2  may be completely overlapped by the light emitting layer  182   c.    
     Referring to  FIG.  5 D , the connection electrode CE may include a first contact portion CT 1 , a second contact portion CT 2  spaced apart from the first contact portion CT 1  in the second direction D 2 , and a curved wiring portion CCL which connects the first contact portion CT 1  to the second contact portion CT 2 . The curved wiring portion CCL may have an arc shape or a curved shape. The curved wiring portion CCL may overlap the light emitting layer  182   c . For example, the light emitting layer  182   c  may completely overlap the curved wiring portion CCL. 
       FIG.  6    is a cross-sectional diagram of a display apparatus according to an exemplary embodiment of the present inventive concept, and  FIG.  7    is a plan diagram illustrating an electrode, a pixel electrode, and a light emitting layer of the display apparatus of  FIG.  6   . 
     Referring to  FIGS.  6  and  7   , the display apparatus may include a base substrate  100 , a buffer layer  110 , an active pattern ACT of a thin film transistor TFT, a first insulating layer  120 , a first gate conductive layer, a second insulating layer  130 , a second gate conductive layer, a third insulating layer  140 , a first source-drain conductive layer, a first via insulating layer VIA 1 , a second source-drain conductive layer, a second via insulating layer VIA 2 , a pixel defining layer PDL, a light emitting structure  180 , and a thin film encapsulation layer TFE. Components of the display apparatus of  FIG.  6    may be substantially the same as the components of the display apparatus of  FIGS.  3  and  4   , respectively, except that the display apparatus of  FIG.  6    further includes the second source-drain conductive layer; Thus, any redundant descriptions thereof may be omitted. 
     The first gate conductive layer may include a gate electrode GE of the thin film transistor TFT. The second gate conductive layer may include a storage electrode STE which overlaps the gate electrode GE to form a storage capacitor. 
     The first source-drain conductive layer may include a source electrode SE and a drain electrode DE of the thin film transistor TFT. The second source-drain conductive layer may include an electrode EL. The electrode EL may include a contact portion CP, a dummy curved wiring portion DM spaced apart from the contact portion CP in the second direction D 2 , and a connection wiring portion CL which connects the dummy curved wiring portion DM to the contact portion CP. The dummy curved wiring portion DM may have a curved line shape, and may have, for example, an annular shape. The dummy curved wiring portion DM may overlap the light emitting layer  182  of the light emitting structure  180 . For example, the dummy curved wiring portion DM may be completely overlapped by the light emitting layer  182 . 
     The contact portion CP of the electrode EL may be electrically connected to the first electrode  181  of the light emitting structure  180  through a contact hole formed through the second via insulating layer VIA 2 . The contact portion CP of the electrode EL may be electrically connected to the thin film transistor TFT through a contact hole formed through the first via insulating layer VIA 1 . 
     In an exemplary embodiment of the present inventive concept, the electrode EL may be similar to the connection electrodes in  FIGS.  5 A- 5 D . For example, the electrode EL may include a first contact portion, a second contact portion spaced apart from the first contact, and a curved wiring portion connecting the first and second contact portions to each other. For example, the first contact portion or the second contact portion may be connected to the thin film transistor TFT. However, the present inventive concept is not limited thereto. For example, each of the first contact portion and the second contact portion may be electrically connected to a conductive pattern (e.g., the thin film transistor TFT) through a contact hole formed through the first via insulating layer VIA 1 . 
       FIG.  8    is a block diagram illustrating an electronic apparatus according to an exemplary embodiment of the present inventive concept,  FIG.  9 A  is a diagram illustrating an example in which the electronic apparatus of  FIG.  8    is implemented as a television, and  FIG.  9 B  is a diagram illustrating an example in which the electronic apparatus of  FIG.  8    is implemented as a smart phone. 
     Referring  FIGS.  8  and  9   , the electronic apparatus  500  may include a processor  510 , a memory device  520 , a storage device  530 , an input/output (I/O) device  540 , a power supply  550 , and a display apparatus  560 . Here, the display apparatus  560  may be the display apparatus of  FIG.  1   . In addition, the electronic apparatus  500  may further include a plurality of ports for communicating with, for example, a video card, a sound card, a memory card, a universal serial bus (USB) device, other electronic apparatuses, etc. In an exemplary embodiment of the present inventive concept, as illustrated in  FIG.  9 A , the electronic apparatus  500  may be implemented as a television. In an exemplary embodiment of the present inventive concept, as illustrated in  FIG.  9 B , the electronic apparatus  500  may be implemented as a smart phone. However, the electronic apparatus  500  is not limited thereto. For example, the electronic apparatus  500  may be implemented as a cellular phone, a video phone, a smart pad, a smart watch, a tablet personal computer (PC), a car navigation system, a computer monitor, a laptop, a head mounted display (HMD) apparatus, etc. 
     The processor  510  may perform various computing functions. The processor  510  may be a micro processor, a central processing unit (CPU), an application processor (AP), etc. The processor  510  may be coupled to other components via an address bus, a control bus, a data bus, etc. Further, the processor  510  may be coupled to an extended bus such as a peripheral component interconnection (PCI) bus. The memory device  520  may store data for operations of the electronic apparatus  500 . For example, the memory device  520  may include at least one non-volatile memory device such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistance random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc. and/or at least one volatile memory device such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile DRAM device, etc. For example, the storage device  530  may include a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I/O device  540  may include an input device such as a keyboard, a keypad, a mouse device, a touch-pad, a touch-screen, etc., and an output device such as a printer, a speaker, etc. The power supply  550  may provide power for operations of the electronic apparatus  500 . 
     The display apparatus  560  may be coupled to other components via the buses or other communication links. In an exemplary embodiment of the present inventive concept, the I/O device  540  may include the display apparatus  560 . As described above, in the display apparatus  560 , a connection electrode of a source-drain conductive layer disposed under a light emitting layer of a light emitting structure includes a curved wiring portion or a dummy portion, so that a concavo-convex portion may be formed on a top surface of a first electrode of the light emitting structure. Accordingly, WAD distribution may be improved, and variations of luminance and color coordinates according to an azimuth angle may be reduced. Since these are described above, the duplicated description related thereto will not be repeated. 
     The present inventive concept may be applied to a display apparatus and an electronic apparatus including the display apparatus. For example, the present inventive concept may be applied to a smart phone, a cellular phone, a video phone, a smart pad, a smart watch, a tablet PC, a car navigation system, a television, a computer monitor, a laptop, a head mounted display apparatus, etc. 
     While the present inventive concept has been described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the present inventive concept.