JP4639662B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device and an electronic apparatus.

Organic electroluminescence (hereinafter abbreviated as EL) elements using electroluminescence have characteristics such as high visibility and excellent impact resistance due to self-emission. The use as a light emitting element has attracted attention. For example, in the case of a top emission organic EL element, the organic EL element generally has a structure in which an anode made of a reflective metal film, a functional layer including an organic light emitting layer, and a cathode made of a transparent conductive film are provided. In particular, in an active matrix EL element including a switching element such as a thin film transistor (hereinafter abbreviated as TFT) for driving an EL element, the anode is a pixel electrode connected to each TFT, and the cathode is It is a solid common electrode shared by a plurality of pixels arranged in a matrix.
In the top emission type organic EL display device, in order to emit light uniformly, the surface of the substrate on which TFTs and matrix wiring are formed is flattened with an organic or inorganic insulating layer, and a pixel electrode is formed on this plane. Was.
However, (1) the number of flattening steps increases. (2) In the case of an organic flattening film, oxygen and moisture permeate the flattening film and deteriorate the element characteristics, and therefore measures such as covering the surface and side surfaces of the flattening film with an inorganic insulating film or the like are required. . (3) A sufficient flatness cannot be obtained with a conventional inorganic planarization film. (4) For example, when an organic layer such as a light emitting layer is stacked by an ink jet method, it cannot be formed flat due to the influence of minute irregularities generated on the surface of the flattening film, and light is not emitted uniformly in the pixel. There was a problem.
As a technique for solving the above problem, an EL display device that reflects light emitted from a light emitting layer by providing a metal portion including a power supply line in a position overlapping with a pixel display portion in a stacking direction is disclosed (for example, Patent Document 1). According to this EL display device, the power supply line disposed below the pixel display unit is formed by stacking flat patterns from the substrate. Therefore, since the pixel electrode can be formed in the upper layer of the power supply line having the flat pattern, the flattening step as described above can be omitted.
JP 2004-6137 A

Incidentally, in the above-mentioned top emission type EL display device, a transparent conductive film such as ITO (Indium Tin Oxide) is widely used for the common electrode in order to extract light from the common electrode side. However, a transparent conductive film such as ITO has a specific resistance that is two to three orders of magnitude higher than that of a metal such as aluminum, and particularly when a large display is manufactured, the voltage drop becomes large. Therefore, in the conventionally proposed method of supplying a drive current to the pixel electrode, that is, a method of supplying the drive current to the pixel electrode using an auxiliary wiring or the like, the resistance of the ITO electrode can be reduced so much. In other words, there is a problem in that the emission luminance differs between the central portion and the outer peripheral portion of the display area of the EL display device, and the display quality deteriorates. Furthermore, the problem of forming a planarization film for forming the pixel electrode as described above in parallel with such a problem must be solved at the same time.
The present invention has been made in view of the above problems, and its purpose is to simplify the process of an organic electroluminescence display device, and to prevent uneven luminance in a display region and to provide a high-brightness organic electroluminescence display device and To provide electronic equipment.

  In order to solve the above problems, the present invention provides a switching element, a first electrode electrically connected to the switching element, a second electrode provided to face the first electrode, and the first electrode. A plurality of pixels arranged in a matrix including an organic electroluminescent element having a light emitting layer provided between an electrode and the second electrode, and at least the first electrode, the second electrode, and the light emitting layer; A first conductive part for supplying current to the first electrode, and a second conductive part for supplying current to the second electrode, wherein the organic electroluminescence device comprises: The luminescence element is formed in a flat region of the first conductive part and the second conductive part. The first conductive portion may be a power supply line, and the second conductive portion may be a cathode auxiliary wiring.

  According to such a configuration, the organic electroluminescence element is formed directly on the upper layer side of the first conductive portion and the second conductive portion via the insulating film. Therefore, even when the surface of the substrate on which the TFT or the like is formed is flattened with an organic or inorganic insulating layer and the step of forming the first electrode on the flat surface is omitted, the light emitting layer can uniformly emit light. Further, since it is not necessary to use an organic flattening film by omitting the flattening film forming step, oxygen and moisture do not pass through the organic flattening film, and display quality deterioration can be suppressed. In addition, since the second conductive portion for supplying current to the second electrode has a wider wiring width than before, the resistance can be reduced, thereby increasing the luminance of the organic electroluminescence display device. it can. The pixel in the present invention is used in a broad concept including organic electroluminescence and other switching elements.

In addition, it is also preferable that the first conductive portion and the second conductive portion are respectively provided in a stripe shape, and are disposed substantially parallel to each other on a lower layer side of the first electrode in plan view.
According to such a configuration, the upper layer side of the first conductive portion and the second conductive portion formed so as to avoid the switching element, the signal line, and the scanning line is a flat surface. Therefore, the first electrode can be provided on the flat surface on the upper layer side of the first conductive portion and the second conductive portion, so that the light in the pixel can be uniformly emitted, and the step of forming the planarization film is omitted. can do. In addition, since the second conductive portion and the first conductive portion are provided in a stripe shape, the wiring width of the second conductive portion can be provided substantially the same as the wiring width of the first conductive portion. As a result, the second conductive portion for supplying current to the second electrode can be reduced in resistance because the wiring width is wider than before, and for example, sufficient current for the second electrode made of ITO can be achieved. Can be supplied. As a result, it is possible to eliminate variations in luminance due to a voltage drop at the peripheral portion and the central portion of the display region, and to increase the luminance of the organic electroluminescence display device.

It is also preferable that the first conductive part is provided in the same layer as the second conductive part.
According to such a configuration, since the first conductive portion is provided in the same layer as the second conductive portion, it can be simultaneously formed in the same process, so that the manufacturing process can be simplified.

It is also preferable that the first electrode is provided over substantially the entire area of the first conductive portion and the second conductive portion in each pixel.
According to such a configuration, since the first electrode is provided over almost the entire area of the first conductive portion and the second conductive portion in each pixel, the area of the first electrode can be increased. Therefore, the aperture ratio (light emission area ratio) of each pixel can be improved. As a result, it is possible to increase the brightness of the organic electroluminescence display device.

Further, it is also preferable that the second conductive portion and the second electrode are electrically connected through a contact hole penetrating an insulating layer interposed therebetween.
According to such a configuration, since the second conductive portion and the second electrode are electrically connected via the contact hole, the second conductive portion and the second electrode can be formed in different layers. Therefore, the degree of freedom in design is improved. Furthermore, a sufficient current can be supplied to the second electrode made of ITO or the like having a higher specific resistance than metal. As a result, it is possible to eliminate variations in luminance due to a voltage drop at the peripheral portion and the central portion of the display region, and to increase the luminance of the organic electroluminescence display device.

Further, in each of the pixels, an organic electroluminescence element is divided and provided in the first conductive portion and the second conductive portion, and the organic electroluminescence element provided in the first conductive portion and the second conductive portion. It is also preferred that the luminescence element shares the first electrode.
Due to the structure of the organic EL display device, there may be a stepped portion between the first conductive portion and the second conductive portion. In this case, when the first electrode is formed across the first conductive portion and the second conductive portion, it is difficult to emit light uniformly because there is a step portion between the first conductive portion and the second conductive portion. . According to the configuration of the present invention, since the organic electroluminescence L element is divided and provided with the step portion between the first conductive portion and the second conductive portion as a boundary, the flat organic electroluminescence without the step portion is provided. An element can be provided. Thereby, light can be emitted uniformly.
In the case of a polymer type organic electroluminescence display device in which an organic layer is formed by a wet process, an organic electroluminescence element is divided by forming an insulating film on the stepped portion. Therefore, a short circuit between the first electrode and the second electrode can be prevented by the insulating film formed in the step portion.
In addition, since the organic electroluminescence elements formed on the first conductive portion and the second conductive portion share the first electrode, two organic elements provided on the first conductive portion and the second conductive portion, respectively. The electroluminescence element can be driven by one drive circuit connected to the first electrode. Accordingly, the area occupied by the drive circuit can be omitted, and thereby the aperture ratio (light emission area ratio) of the pixel can be improved. As a result, it is possible to increase the brightness of the organic electroluminescence display device.

The first conductive part and the second conductive part may be provided in a stacked manner, and the first electrode may be provided on the upper layer side of the first conductive part or the second conductive part. preferable.
According to such a configuration, the first conductive portion and the second conductive portion are provided so as to overlap in a planar manner. Therefore, the first conductive portion and the second conductive portion are formed in a stripe shape due to the structure of the organic electroluminescence device. It is possible to avoid adverse effects caused by the provision, that is, generation of a step at the boundary between the first conductive portion and the second conductive portion. Accordingly, since there is no step at the boundary between the first conductive portion and the second conductive portion, it is not necessary to divide the organic electroluminescence element with the step portion as a boundary, and the first electrode can be formed in a large area. Therefore, the aperture ratio (light emission area ratio) of the pixel can be improved, and the luminance of the organic electroluminescence device can be increased.

Further, the second conductive portion is provided separately for each adjacent pixel, and the second conductive portion is provided separately for the adjacent pixels via a relay layer provided in the same layer as the first conductive portion. It is also preferable to electrically connect the conductive parts.
According to such a configuration, since the relay layer is provided between the adjacent pixels, the current (electrons) supplied from the external drive circuit passes through the second conductive portions of the adjacent pixels one after another. Two electrodes can be reached. Therefore, a sufficient current can be supplied to the second electrode made of ITO or the like having a higher specific resistance than metal. As a result, it is possible to eliminate variations in luminance due to a voltage drop at the peripheral portion and the central portion of the display region, and to increase the luminance of the organic electroluminescence display device.

An electronic apparatus according to the present invention includes the organic electroluminescence device.
According to the present invention, by providing the organic electroluminescence device, it is possible to realize an electronic device having high luminance and excellent display quality.

[First Embodiment]
DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment that is the best mode of the present invention will be described below with reference to the drawings. In all the following drawings, the scale of each layer and each member is shown to be different from the actual scale so that each layer and each member has a size that can be recognized on the drawings. Further, the auxiliary cathode wiring 107 (second conductive portion) and the like are omitted in FIG.

FIG. 1 is an equivalent circuit diagram showing a wiring structure of the organic EL display device of the present embodiment.
As shown in FIG. 1, the organic EL display device 1 according to the present embodiment includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting the scanning lines 101, and the signal lines 102 extending in parallel. A plurality of power supply lines 103 (first conductive portions) are respectively wired in a grid pattern. An area defined by the scanning line 101 and the signal line 102 is configured as a pixel A.
The signal line 102 is connected to a data side driving circuit 104 including a shift register, a level shifter, a video line, and an analog switch. Further, a scanning side driving circuit 105 including a shift register and a level shifter is connected to the scanning line 101.

  Each pixel A includes a switching TFT 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101, a holding capacitor 4 for holding a pixel signal supplied from the signal line 102 via the switching TFT 112, A driving TFT 123 is provided in which the pixel signal held by the holding capacitor 4 is supplied to the gate electrode. Further, each pixel A has a pixel electrode 111 (first electrode) into which a driving current flows from the power supply line 103 when electrically connected to the power supply line 103 via the driving TFT 123, and the pixel electrode A common electrode 12 (second electrode) disposed opposite to each other and a functional layer 110 sandwiched between the pixel electrode 111 and the common electrode 12 are provided. In the organic EL display device 1, a plurality of the pixels A are formed in a matrix.

  According to this configuration, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor 4, and the driving TFT 123 of the driving TFT 123 depends on the state of the holding capacitor 4. The on / off state is determined. Then, current flows from the power supply line 103 to the pixel electrode 111 through the channel of the driving TFT 123, and further current flows to the common electrode 12 through the functional layer 110. The functional layer 110 emits light with a luminance corresponding to the amount of current flowing therethrough.

FIG. 2 is a schematic plan view of the organic EL display device 1 in the present embodiment.
As shown in FIG. 2, the organic EL display device 1 includes a plurality of substrates 2 arranged adjacent to each other on a large support substrate 180. The support substrate 180 is a substrate that integrally supports the plurality of substrates 2. In FIG. 2, four substrates 2 are arranged in 2 rows × 2 columns. However, the number of substrates 2 is not limited to this, and it is sufficient that at least two substrates 2 are provided. Each of the substrates 2 includes a display area 50 provided on the substrate 2, a data side driving circuit 104 and a scanning side driving circuit 105 arranged at the peripheral edge of the display area 50. Are formed with a plurality of pixels A arranged in a matrix in plan view. Further, the data side driving circuit 104 and the scanning side driving circuit 105 are electrically connected to the switching TFT 112 and the like constituting each pixel A through the scanning line 101, the signal line 102 and the like. In the present embodiment, as shown in FIG. 2, the image display unit 115 of the organic EL display device 1 is formed by four display regions 50.

In FIG. 2, the gaps between the display areas 50 in the vicinity of the boundaries 70a and 70b between the substrates 2 are widely illustrated to make the drawing easy to see, but actually, the pixels adjacent to each other through the 70a and 70b. The interval between A is extremely narrow, and a process for making the boundary inconspicuous, such as a light shielding process, is performed as necessary.
Further, in this embodiment, each substrate 2 is provided with the data side drive circuit 104 and the scanning side drive circuit 105. However, by connecting the mutual wirings at the boundaries 70a and 70b between the substrates 2, the number is reduced. A plurality of pixels A can be driven by a plurality of data side driving circuits 104 and scanning side driving circuits 105.

FIG. 3 is a plan view showing a schematic configuration of each pixel constituting the light emitting display region.
As shown in FIG. 3, each pixel A including a display element portion (organic EL element) to be described later with three primary colors of R (red), G (green), and B (blue) is arranged in a stripe shape in plan view. They are repeatedly arranged in the middle horizontal direction (only three pixels A are shown in FIG. 3). In the vertical direction in the figure, pixels A corresponding to the same color of R (red), G (green), and B (blue) are arranged. In the present embodiment, a pixel A having an R (red) display element portion will be described, but the other pixels A have the same configuration as the pixel A having an R (red) display element portion. Therefore, explanation is omitted. In order to facilitate understanding of the pixel A, the organic functional light emitting layer, the common electrode, and the like are not shown in FIG.

As shown in FIG. 3, the signal line 102, the power supply line 103, and the auxiliary cathode wiring 107 are arranged in parallel with each other so as to extend in the vertical direction in the figure, and the scanning line 101 is arranged so as to be orthogonal thereto. . A switching TFT 112 is provided corresponding to the intersection of the signal line 102 and the scanning line 101, and the driving TFT 123 and the storage capacitor 4 are connected to the switching TFT 112.
The power supply line 103 and the cathode auxiliary wiring 107 are arranged extending in the vertical direction in the figure in a stripe shape in plan view, and the pixel except for the switching TFT 112, the driving TFT 123, and other areas where wiring is arranged. A is formed over the entire region A. Here, the power supply line 103 and the cathode auxiliary wiring 107 are formed with substantially the same wiring width. The power supply line 103 is connected to the source region of the driving TFT 123 disposed adjacent thereto, and supplies a current to the pixel electrode 111 when the switch of the driving TFT 123 is turned on. The cathode auxiliary wiring 107 is connected to a common electrode 12 (second electrode), which will be described later, via a contact hole 30, and supplies current (electrons) to the common electrode 12.

The switching TFT 112 is formed on the lower side of the gate electrode 15a extended from the scanning line 101 and the extended gate electrode 15a, and is opposed to the extended gate electrode 15a with the gate insulating film 35 interposed therebetween. The semiconductor layer 20 has a formed channel region, and has a source region and a drain region formed on both sides of the semiconductor layer 20.
The driving TFT 123 is formed on the lower side of the gate electrode 15a that extends from the first capacitor electrode 15 that constitutes a storage capacitor, which will be described later, and on the extended gate electrode 15a. The semiconductor layer 25 has a channel region formed so as to face each other across the gate insulating film 15a, and a source region and a drain region formed on both sides of the semiconductor layer 25. Further, the first capacitor electrode 15 constituting the gate electrode 15 a of the driving TFT 123 is formed in a rectangular shape on the lower layer side of the power supply line 103 with substantially the same wiring width as that of the power supply line 103. The second capacitor electrode 16 formed to extend from the semiconductor layer 25 of the driving TFT 123 is formed in a rectangular shape having substantially the same area as the first capacitor electrode 15 and is insulated on the lower layer side of the first capacitor electrode 15. It arrange | positions through the film | membrane. The storage capacitor 4 is constituted by the first capacitor electrode 15 and the second capacitor electrode 16 formed so as to face the stacking direction of the first capacitor electrode 15.

The source region of the semiconductor layer 20 of the switching TFT 112 is connected to the signal line 102 via the contact hole 21. On the other hand, the drain region of the semiconductor layer 20 of the switching TFT 112 is connected to the first relay conductive layer 23 through the contact hole 22. The first relay conductive layer 23 is connected via a contact hole 29 to a gate electrode 15 a of a driving TFT 123 extending from a first capacitance electrode 15 described later.
The source region of the semiconductor layer 25 of the driving TFT 123 is connected to the power supply line 103 through the contact hole 26. On the other hand, the drain region of the semiconductor layer 25 of the driving TFT 123 is connected to the second relay conductive layer 24 through the contact hole 27.

Further, the pixel electrode 111 is connected to the second relay conductive layer 24 through the contact hole 28, and when the driving TFT 123 is turned on, a current is supplied from the power supply line 103 to the pixel electrode 111. ing. The pixel electrode 111 is formed in a rectangular shape on the entire upper layer side of the power supply line 103 and the cathode auxiliary wiring 107 wired in the pixel A.
As will be described later, the bank 7 includes a first bank layer 7a and a second bank layer 7b. The bank 7 is formed at the periphery of the pixel electrode 111 and at the boundary between the power supply line 103 and the cathode auxiliary wiring 107, and the pixel A is divided into two display element portions. The bank 7 is patterned so that the openings of the two display element portions have an oval shape in the vertical direction in the figure.

Next, a cross-sectional structure of the organic EL display device 1 of the present embodiment will be described with reference to FIGS. 4 (a) and 4 (b).
FIG. 4A is a cross-sectional view taken along the line AA ′ of the organic EL display device of FIG. As shown in FIG. 4A, in the organic EL display device 1 of the present embodiment, the circuit element unit 14 and the display element unit 10 are sequentially stacked on the substrate 2, and the substrate surface on which the stacked body is formed is sealed. It has a structure sealed by a stop. The display element unit 10 includes a pixel electrode 111, an organic functional layer Y stacked on the pixel electrode 111, and a common electrode 12 formed on the organic functional layer Y. The common electrode 12 and the sealing portion have translucency, and the organic EL display device 1 of the present embodiment is a so-called top emission type in which display light emitted from the light emitting layer is emitted from the sealing portion side. The organic EL display device 1 is configured.

  Specifically, as shown in FIG. 4A, on the substrate 2, a first protective film 31 made of a silicon oxide film or the like, a semiconductor layer 25, a second capacitor electrode 16 constituting the storage capacitor 4, and a gate insulating film 35 are laminated. Here, in the present embodiment, since the organic EL display device 1 employs a top emission type, any of a transparent substrate, a translucent substrate, and an opaque substrate can be used for the substrate 2. Examples of the transparent or translucent substrate include glass, quartz, and resin (plastic and plastic film). As the opaque substrate, for example, a ceramic sheet such as alumina or a metal sheet such as stainless steel subjected to an insulation treatment such as surface oxidation, a thermosetting resin, a thermoplastic resin, or the like can be given.

On the first protective film 31, a semiconductor layer 25 and a second capacitor electrode 16 formed by patterning a thin film of a semiconductor material such as silicon into a predetermined shape are formed flat in the same layer, covering these layers from the silicon oxide film. A gate insulating film 35 is formed. Here, the semiconductor layer 25 constitutes a driving TFT 123 and has a drain region, a source region, and a channel region.
On the gate insulating film 35, a gate electrode 15a formed opposite to the semiconductor layer 25 and a first capacitor electrode 15 formed opposite to the second capacitor electrode 16 are formed flat in the same layer. . The first insulating film 36 is formed so as to cover the gate electrode 15 a and the first capacitor electrode 15. The contact holes 26 and 27 are formed so as to penetrate the first insulating film 36 and the gate insulating film 35 to reach the semiconductor layer 25 and expose the surface of the semiconductor layer 25.

  The power supply line 103 is formed flat on the first capacitor electrode 15 via the first insulating film 36 and is electrically connected to the source region of the semiconductor layer 25 of the driving TFT 123 via the contact hole 26. Here, the wiring width of the power supply line 103 is substantially the same as that of the first capacitor electrode 15 and is formed on a flat surface so as to overlap the position of the first capacitor electrode 15. The power supply line 103 is made of a metal such as aluminum (Al), chromium (Cr), or tantalum (Tr). Further, the second relay conductive layer 24 is formed in the same layer as the power supply line 103, and is made of the same metal as the power supply line 103 and is electrically connected to the pixel electrode 111 through the contact hole 27. (Not shown).

  The cathode auxiliary wiring 107 is formed flat adjacent to the same layer as the power supply line 103, and the wiring width of the cathode auxiliary wiring 107 is formed with substantially the same wiring width as that of the power supply line 103. The cathode auxiliary wiring 107 is preferably made of a low-resistance conductive material, and is made of, for example, a metal such as chromium (Cr) / gold (Au), titanium (Ti) / copper (Cu) / titanium nitride (TiN), or the like. ing. In this embodiment, the cathode auxiliary wiring 107 is formed in the same layer as the power supply line 103, but the first capacitor electrode 15 and the like are formed in the lower layer of the region where the cathode auxiliary wiring 107 is formed. Therefore, there is a step at these boundaries.

The second insulating film 37 is formed so as to cover the power supply line 103, the cathode auxiliary wiring 107, the signal line 102, and the like, and on the power supply line 103 and the cathode auxiliary wiring 107, a region excluding the step portion is formed flat.
The pixel electrode 111 is formed on a flat surface on the power supply line 103 and the auxiliary cathode wiring 107 via the second insulating film 37, and is a flat surface except for a region excluding a step portion between the power supply line 103 and the auxiliary cathode wiring 107. ing. The pixel electrode 111 is made of, for example, a metal with high light reflectivity such as aluminum or silver, and has a function of injecting holes into the organic functional layer Y. In the case where a metal having high light reflectivity is used as the material for the power supply line 103 and the cathode auxiliary wiring 107, it is also preferable to use a transparent conductive film such as ITO as the material for the pixel electrode 111.
The first bank layer 7a constituting the bank 7 is formed from the peripheral edge of the pixel electrode 111 over the second insulating film 37 where the pixel electrode 111 is not formed so that the opening of the pixel electrode 111 has an oval shape. Has been. Further, the first bank layer 7a is formed on a stepped portion between the power supply line 103 and the auxiliary cathode wiring 107, and corresponds to each display element portion 10 with the stepped portion between the power supply line 103 and the auxiliary cathode wiring 107 as a boundary. In addition to forming the elliptical opening, one pixel A is divided into two display element portions 10.

The second bank layer 7b constituting the bank 7 is formed on the first bank layer 7a so as to partially overlap the peripheral portion of the pixel electrode 111 as described above. Further, the second bank layer 7 b is formed on the first bank layer 7 a formed on the step portion between the power supply line 103 and the cathode auxiliary wiring 107, and divides one pixel A into two display element portions 10. Yes. The bank 7 is preferably formed of a material that blocks or suppresses light emitted from the organic functional layer Y, for example. For example, it is preferable to use SiO ₂ , TiO ₂ , SiN or the like as the material of the first bank layer 7a, and it is preferable to use acrylic resin, polyimide resin or the like as the material of the second bank layer 7b. The bank 7 is also preferably composed of a single layer made of acrylic resin, polyimide resin, or the like.

An organic functional layer Y is stacked on the pixel electrode 111 in a region that is a recess between the banks 7. The organic functional layer Y includes a hole injection / transport layer 61 laminated on the pixel electrode 111 and a light emitting layer 62 formed on the hole injection / transport layer. For the hole injection / transport layer 61, for example, a mixture of a polythiophene derivative such as polyethylene dioxythiophene (PEDOT) and polystyrene sulfonic acid can be used. In addition, the light emitting layer 62 has three types, a red light emitting layer that emits red (R), a green light emitting layer that emits green (G), and a blue light emitting layer that emits blue (B). Layers 62 are arranged in stripes. As the material of the light emitting layer 62, cyanopyriphenylene vinylene can be used as the red light emitting layer, and polyphenylene vinylene can be used as the green light emitting layer and the blue light emitting layer.

  The common electrode 12 is formed so as to cover the entire surface of the region including the organic functional layer Y and the bank 7, and has a function of injecting electrons into the organic functional layer Y as a counter electrode of the pixel electrode 111. Further, the common electrode 12 employs an electron injection layer made of bathophencesium or the like formed on the organic functional layer Y and a top emission type organic EL device 1 in this embodiment, and the emitted light is emitted from the common electrode 12. Since it needs to be taken out from the side, the upper layer of the electron injection layer has a two-layer structure including a transparent conductive film such as ITO. The upper layer of the common electrode 12 is covered with an organic or / and inorganic transparent sealing film 43 for preventing intrusion of oxygen and moisture, and a cover glass 45 is provided via an adhesive layer 44.

FIG. 4B is a cross-sectional view taken along the line BB ′ of the organic EL display device of FIG. Note that the description of the same components as those in FIG.
As shown in FIG. 4B, the first protective film 31, the second capacitor electrode 16, the gate insulating film 35, the first capacitor electrode 15, and the first insulating film 36 are stacked on the substrate 2. In the same layer on the first insulating film 36, the power source line 103 and the cathode auxiliary wiring 107 are formed, and the second insulating film 37 is formed so as to cover them. Further, the pixel electrode 111 and the bank 7 are stacked on the second insulating layer 37.

  4A, in the region where the driving TFT 123 is formed, the second insulating layer 37 and the bank 7 are penetrated in the region BB ′ in FIG. 4B. Thus, a contact hole 30 reaching the cathode auxiliary wiring 107 is formed. Further, in the BB ′ cross-sectional area of FIG. 4B, the wiring width of the cathode auxiliary wiring 107 is formed wider than that of other portions, extends to the lower layer of the contact hole 30, and the cathode auxiliary wiring 107 is formed. And the common electrode 12 are electrically connected.

  According to the present embodiment, the pixel electrode 111 is provided on the upper layer side of the power supply line 103 and the cathode auxiliary wiring 107 so as to overlap the power supply line 103 and the cathode auxiliary wiring 107 in a plane. That is, the pixel electrode 111 is formed directly on the upper side of the power supply line 103 and the auxiliary cathode wiring 107 through the first insulating film 36. Therefore, the conventional process of flattening the surface of the substrate on which the TFTs are formed in order to uniformly emit light from the light emitting layer with an organic or inorganic insulating layer and forming the pixel electrode 111 on this flat surface is omitted. can do. Further, since it is not necessary to use an organic flattening film by omitting the flattening film forming step, oxygen and moisture do not pass through the organic flattening film, and display quality deterioration can be suppressed.

Further, according to the present embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are provided substantially in a stripe shape, and therefore the upper layer side of the power supply line 103 and the cathode auxiliary wiring 107 is a flat surface. Therefore, the pixel electrode 111 can be provided on a flat surface on the upper layer side of the power supply line 103 and the cathode auxiliary wiring 107, and the light in the pixel A can be emitted uniformly, and the planarization film forming step is omitted. can do.
In the case of the polymer type organic EL display device 1 in which the organic functional layer Y is formed by a wet process, the display element portion 10 is divided by forming the first bank layer 7a at the stepped portion. . Therefore, a short circuit between the pixel electrode 111 and the common electrode 12 can be prevented by the first bank layer 7a formed by the step portion.
Further, since the power supply line 103 and the cathode auxiliary wiring 107 share the pixel electrode 111, the two display element portions 10 provided respectively on the power supply line 103 and the cathode auxiliary wiring 107 are connected to the pixel electrode 111. It can be driven by a single driving circuit. Therefore, the space of the drive circuit can be saved, and thereby the aperture ratio (light emission area ratio) of the pixel can be improved. As a result, the brightness of the organic EL display device can be increased.
Further, since the cathode auxiliary wiring 107 and the power supply line 103 are provided in a stripe shape, the wiring width of the cathode auxiliary wiring 107 can be provided substantially the same as the wiring width of the power supply line 103. As a result, the auxiliary cathode wiring 107 for supplying current (electrons) to the common electrode 12 can be reduced in resistance because the wiring width is wider than before, and sufficient current can be supplied to the common electrode 12 made of ITO. it can. As a result, it is possible to eliminate the variation in luminance due to the voltage drop at the peripheral portion and the central portion of the display region, and it is possible to increase the luminance of the organic EL display device 1 and improve the display quality.

[Second Embodiment]
Hereinafter, the present embodiment will be described with reference to FIGS.
In the first embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are formed in the same layer. On the other hand, the present embodiment is different in that the power supply line 103 and the cathode auxiliary wiring 107 are formed in different layers. The other basic configuration of the organic EL display device 1 is the same as that of the first embodiment, and common constituent elements are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 5 is a plan view showing a schematic configuration of each pixel A constituting the light emitting display region. As shown in FIG. 5, each pixel A including the display element portions 10 of the three primary colors R (red), G (green), and B (blue) is arranged in a stripe shape in plan view.
As shown in FIG. 5, the power supply line 103, the cathode auxiliary wiring 107, and the signal line 102 are arranged in parallel with each other so as to extend in the vertical direction in the drawing, and on the lower side in the drawing so as to be orthogonal to these. Is arranged. A switching TFT 112 is provided corresponding to the intersection of the scanning line 101 and the signal line 102, and the driving TFT 123 and the storage capacitor 4 are connected to the switching TFT 112. The difference from the first embodiment is that the switching TFT 112, the driving TFT 123, and the like are arranged on the lower side of the pixel A in the drawing.

Next, a cross-sectional structure of the organic EL display device 1 of the present embodiment will be described with reference to FIGS.
FIG. 6A is a cross-sectional view taken along the line CC ′ of the organic EL display device of FIG. As shown in FIG. 6A, on the substrate 2, a first protective film 31, a second capacitor electrode 16 constituting the storage capacitor 4, a gate insulating film 35, a first capacitor electrode 15 forming the storage capacitor 4, A first insulating film 36 is stacked. A power line 103 is formed on the first insulating film 36 so as to be substantially equal to the wiring width of the first capacitor electrode 15 and to overlap the position of the first capacitor electrode 15, and covers the second insulating film 36 to cover the second insulating film 36. A film 37 is formed.

  On the second insulating film 37, a cathode auxiliary wiring 107 is formed flat, and a third insulating film 38 is formed so as to cover the entire surface including the cathode auxiliary wiring 107. Here, the auxiliary cathode wiring 107 is formed in a layer different from the power line 103 and is formed in a region that does not overlap with the position where the power line 103 is formed. On the third insulating film 38, the pixel electrode 111 is formed flat so as to overlap the power supply line 103 and the cathode auxiliary wiring 107 formed in a stripe shape in plan view on the lower layer side. The bank 7 is formed on the third insulating film 38 where the pixel electrode 111 is not formed from the peripheral portion of the pixel electrode 111 so that the opening of the pixel electrode 111 has a rectangular shape. Further, the bank 7 is formed on a stepped portion between the power supply line 103 and the cathode auxiliary wiring 107, and a rectangular opening corresponding to each step is formed with the stepped portion between the power supply line 103 and the cathode auxiliary wiring 107 as a boundary. In addition, one pixel A is divided into two display element portions 10. On the pixel electrode 111 and the bank 7, the organic functional layer Y, the common electrode 12, the transparent sealing film 43, the adhesive layer 44, and the cover glass 45 are laminated. Note that the bank 7 includes the first bank layer 7a and the second bank layer 7b formed on the first bank layer 7a as described in the first embodiment.

FIG. 6B is a cross-sectional view taken along the line DD ′ of the organic EL display device of FIG. Note that the description of the same components as those in FIG.
As shown in FIG. 6B, a first protective film 31, a semiconductor layer 25 of a driving TFT 123 formed by patterning a thin film of a semiconductor material such as silicon into a predetermined shape, and a gate insulating film 35 are laminated on the substrate 2. ing. The gate electrode 15a of the driving TFT 123 is formed to face the semiconductor layer 25 with the gate insulating film 35 interposed therebetween, and the first insulating film 36 is formed to cover the entire surface including the gate electrode 15a. Here, the semiconductor layer 25 has a drain region, a channel region, and a source region. The contact holes 26 and 27 are formed so as to penetrate the first insulating film 36 and the gate insulating film 35 to reach the semiconductor layer 25 and expose the surface of the semiconductor layer 25.

  The power supply line 103 is formed on the first insulating film 36 and is electrically connected to the source region of the driving TFT 123 through the contact hole 26. The second relay conductive layer 24 formed in the same layer as the power supply line 103 is connected to the drain region of the driving TFT 123 through the contact hole 27. A second insulating film 37 is formed so as to cover these, and a cathode auxiliary wiring 107 is formed on the second insulating film 37. The contact hole 28a is formed so as to penetrate the second insulating film 37 to reach the second relay conductive layer 24 and expose the surface of the second relay conductive layer 24. Inside the contact hole 28a, the cathode auxiliary wiring is formed. Part of 107 is filled. A second insulating film 37 is formed on the peripheral edge of the contact hole 28a to insulate the auxiliary cathode wiring 107 filled in the contact hole 28a from the auxiliary cathode wiring 107 formed on the peripheral edge of the contact hole 28a. Yes. The third insulating film 38 is formed so as to cover the cathode auxiliary wiring 107.

  The contact hole 28b penetrates the third insulating film 38 and reaches a part of the cathode auxiliary wiring 107 filled in the contact hole 28a. The pixel electrode 111 is connected to a part of the cathode auxiliary wiring 107 through the contact hole 28b, and is electrically connected to the second relay conductive layer 24 using a part of the cathode auxiliary wiring 107 as a relay layer. ing.

  The contact hole 30 is formed so as to penetrate the third insulating film 38 and reach the cathode auxiliary wiring 107 and expose the surface of the cathode auxiliary wiring 107. The conductive layer 334 in the same layer as the pixel electrode 111 is electrically connected to the cathode auxiliary wiring 107 through the contact hole 30, and the contact hole 30 penetrating the bank 7 is in the same layer as the pixel electrode 111. The conductive layer 334 is formed so as to be exposed. The common electrode 12 is formed on the entire surface of the conductive layer 334 and the bank 7 in the same layer as the pixel electrode 111, and the common electrode 12 and the cathode auxiliary wiring 107 are electrically connected.

As described above, in the first embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are both formed in the second layer. However, in the present embodiment, the power supply line 103 is formed in the second layer. The cathode auxiliary wiring 107 is different in that it is formed in the third layer. That is, in this embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are formed in different layers.
According to the present embodiment, since the switching TFT 112 and the driving TFT 123 can be arranged on the lower layer side of the cathode auxiliary wiring 107, the degree of freedom in design is improved. In FIG. 5, although the area of the light emitting region does not seem so large, the light emitting region can be expanded by actually optimizing the arrangement of wirings and TFTs.

[Third Embodiment]
Hereinafter, this embodiment will be described with reference to FIGS.
In the first embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are formed in the same layer and in stripes. On the other hand, the present embodiment is different in that the power supply line 103 is formed in a different layer so as to overlap the cathode auxiliary wiring 107. The other basic configuration of the organic EL display device 1 is the same as that of the first embodiment, and common constituent elements are denoted by the same reference numerals and detailed description thereof is omitted.

FIG. 7 is a plan view showing a schematic configuration of each pixel constituting the light emitting display region.
As shown in FIG. 7, each pixel A including display elements 10 of the three primary colors R (red), G (green), and B (blue) is arranged in a stripe shape in plan view. The signal line 102, the power supply line 103, and the cathode auxiliary wiring 107 are arranged in parallel with each other so as to extend in the vertical direction in the figure, and the scanning line 101 is arranged so as to be orthogonal thereto. A switching TFT 112 is provided corresponding to the intersection of the signal line 102 and the scanning line 101, and the driving TFT 123 and the storage capacitor 4 are connected to the switching TFT 112.

  Further, as shown in FIG. 7, the power supply line 103 is formed in a rectangular shape throughout the pixel A except for the region where the switching TFT 112, the driving TFT 123, the storage capacitor 4 and the like are formed. It is connected to the source region of the semiconductor layer 25. The cathode auxiliary wiring 107 is formed on the lower layer side of the power supply line 103 and is formed in a rectangular shape with substantially the same area as the power supply line 103. That is, in the present embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are formed in different layers, and further, the power supply line 103 and the cathode auxiliary wiring 107 are formed to overlap each other with the first insulating film 36 therebetween. Has been.

  In addition, although the term “wiring” is used in the present embodiment, the auxiliary cathode wiring 107 is formed in a rectangular shape by being separated for each pixel A and overlapping the lower layer side of the power supply line 103. For this reason, the cathode auxiliary wiring 107 is connected to the third relay layer 19 through the plurality of contact holes 41 in order to pass the current to the pixels A (not shown) arranged adjacent in the vertical direction in the drawing. ing. The third relay layer 19 is connected to the cathode auxiliary wiring 107 of the pixels A (not shown) arranged adjacent to each other in the vertical direction in the drawing via the contact hole 41, and the cathode auxiliary between the adjacent pixels A is provided. The wirings 107 are electrically connected. The auxiliary cathode wiring 107 is electrically connected to the common electrode 12 (not shown) through the contact hole 30.

  The first capacitor electrode 15 and the second capacitor electrode 16 are formed on the lower side of the driving TFT 123 in the figure because the power supply line 103 and the cathode auxiliary wiring 107 are stacked on each other. The pixel electrode 111 is formed in a rectangular shape over the entire region excluding the driving TFT 123 and the wiring on the power supply line 103 via an insulating film. The pixel electrode 111 is connected to the second relay conductive layer 24 through the contact hole 28. The bank 7 (partition wall) is formed so as to partially overlap the peripheral edge of the pixel electrode 111. As described in the first and second embodiments, the bank 7 includes the first bank layer 7a and the second bank layer 7b formed on the first bank layer 7a.

Next, a cross-sectional structure of the organic EL display device 1 of the present embodiment will be described with reference to FIG.
FIG. 8 is a cross-sectional view taken along the line EE ′ of the organic EL display device of FIG. As shown in FIG. 8, the first protective film 31, the second capacitor electrode 16, and the gate insulating film 35 are stacked on the substrate 2. The first capacitor electrode 15 is formed to face the second capacitor electrode 16 with the gate insulating film 35 interposed therebetween, and the first capacitor electrode 15 and the second capacitor electrode 16 constitute the storage capacitor 4. The auxiliary cathode wiring 107 is formed in the same layer as the first capacitor electrode 15, and is formed flat substantially over the entire area excluding the second capacitor electrode 16. The first insulating film 36 is formed so as to cover the first wiring layer including the cathode auxiliary wiring 107. The power supply line 103 is formed to face the cathode auxiliary wiring 107 with the first insulating film 36 interposed therebetween, and is formed flat over the entire area of the pixel A with substantially the same wiring width as the cathode auxiliary wiring 107. The pixel electrode 111 is formed on the power supply line 103 formed flat so as to overlap the power supply line 103 through the second insulating film 37. In the bank 7 composed of the first bank layer 7a and the second bank layer 7b, the pixel electrode 111 is not formed from the peripheral edge of the pixel electrode 111 so that the opening of the pixel electrode 111 has a rectangular shape. Two insulating films 37 are formed.

  According to the present embodiment, the power supply line 103 and the cathode auxiliary wiring 107 are provided so as to overlap each other in a plan view. Therefore, the power supply line 103 and the cathode auxiliary wiring 107 are provided in a stripe shape depending on the structure of the organic EL display device 1. It is possible to avoid the adverse effects that occur in some cases, that is, the occurrence of a step at the boundary between the power line 103 and the cathode auxiliary wiring 107. Therefore, since the power supply line 103 is laminated on the cathode auxiliary wiring 107, a flat region without a stepped portion can be formed. As a result, since there is no step portion at the boundary between the power supply line 103 and the auxiliary cathode wiring 107, there is no need to divide the display element portion 10 with the step portion as a boundary, and the pixel electrode 111 can be formed with a large area. Therefore, the aperture ratio (light emission area ratio) of the pixel A can be improved, and the luminance of the organic EL display device 1 can be increased.

[Electronics]
Hereinafter, specific examples of the electronic apparatus including the organic EL display device according to the embodiment of the present invention will be described.
FIG. 9 is a perspective view showing an example of the organic EL television 1200. In FIG. 9, reference numeral 1202 denotes a television body, reference numeral 1203 denotes a speaker, and reference numeral 1201 denotes a display unit using the organic EL display device. The organic EL display device 1 described above can be applied to various electronic devices other than the organic EL television. For example, projectors, multimedia-compatible personal computers (PCs) and engineering workstations (EWS), pagers, word processors, viewfinder type or monitor direct view type video tape recorders, electronic notebooks, electronic desk calculators, car navigation systems, POS The present invention can be applied to electronic devices such as terminals and devices provided with touch panels.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the specific configuration of the common cathode wiring used in the above embodiment, such as the planar shape, material, and arrangement of common electrode contact holes, can be changed as appropriate. Further, the case where the light emitting layers of R (red), G (green), and B (blue) are arranged in stripes has been described, but the present invention is not limited to this, and various arrangement structures can be adopted. For example, in addition to the stripe arrangement, a mosaic arrangement or a delta arrangement may be used. In the above embodiment, the three-color light emission method is used as a principle for realizing full color. However, full color can be realized by various methods such as a filter method (white method) and a color conversion method.
In the present embodiment, the power supply line 103 and the auxiliary cathode wiring 107 are formed with substantially the same wiring width, but the ratio of the power supply line 103 and the auxiliary cathode wiring 107 can be appropriately changed. .
In the present embodiment, a material having a high reflectance is used for the pixel electrode 111. However, even when a material having a low reflectance is used, it is possible to improve the panel luminance by omitting the antireflection optical filter.

It is an equivalent circuit diagram of the organic EL display device of the present invention. It is a top view which shows schematic structure of the organic electroluminescence display of 1st Embodiment. It is a top view which shows the pattern of the RGB pixel of an organic electroluminescent display apparatus similarly. (A) is sectional drawing which follows the AA 'line of FIG. 3, (b) is sectional drawing which follows BB' of FIG. It is a top view which shows schematic structure of the organic electroluminescence display of 2nd Embodiment. (A) is sectional drawing which follows the CC line of FIG. 5, (b) is sectional drawing which follows DD of FIG. It is a top view which shows schematic structure of the organic electroluminescence display of 3rd Embodiment. It is sectional drawing which follows the EE 'line | wire of FIG. It is a perspective view which shows an example of the electronic device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL display apparatus, 10 ... Display element part (organic EL element), 12 ... Common electrode (2nd electrode), 103 ... Power supply line (1st electroconductive part), 107 ... Cathode auxiliary wiring (2nd electroconductive part) 111 ... Pixel electrode (first electrode)

Claims (7)

A switching element; a first electrode electrically connected to the switching element; a second electrode provided to face the first electrode; and the first electrode and the second electrode. An organic electroluminescence device comprising: a light emitting layer; and a plurality of pixels arranged in a matrix including an organic electroluminescence element having at least the first electrode, the second electrode, and the light emitting layer,
A first conductive part for supplying current to the first electrode; and a second conductive part for supplying current to the second electrode;
The first conductive portion and the second conductive portion are provided in the same layer with the upper surface formed flat via a first insulating film,
The organic electroluminescence element is formed in a flat region on the upper surface of the first conductive portion and the second conductive portion via a second insulating film, respectively.
In each pixel, the organic electroluminescence element is divided and provided in the first conductive portion and the second conductive portion, and the organic electroluminescence element provided in the first conductive portion and the second conductive portion. the organic electroluminescent device luminescent device is characterized that you share the first electrode. A switching element; a first electrode electrically connected to the switching element; a second electrode provided to face the first electrode; and the first electrode and the second electrode. An organic electroluminescence device comprising: a light emitting layer; and a plurality of pixels arranged in a matrix including an organic electroluminescence element having at least the first electrode, the second electrode, and the light emitting layer,
A first conductive part for supplying current to the first electrode; and a second conductive part for supplying current to the second electrode;
The first conductive portion is formed with a flat upper surface through a first insulating film,
The second conductive portion has a flat upper surface through a first insulating film and a second insulating film covering the first conductive portion,
The organic electroluminescence element is formed in a flat region on the upper surface of the first conductive portion via the second insulating film and a third insulating film that covers the second insulating film, and the first Formed in a flat region on the upper surface of the two conductive portions through the third insulating film,
In each pixel, the organic electroluminescence element is divided and provided in the first conductive portion and the second conductive portion, and the organic electroluminescence element provided in the first conductive portion and the second conductive portion. An organic electroluminescence device, wherein a luminescence element shares the first electrode . The organic electroluminescence device according to claim 1, wherein the first conductive portion is a power supply line, and the second conductive portion is a cathode auxiliary wiring . The first conductive portion and the second conductive portion are respectively provided in a stripe shape, and are disposed substantially parallel to each other on a lower layer side of the first electrode in plan view. The organic electroluminescence device according to any one of the above. 5. The device according to claim 1, wherein the first electrode is provided over substantially the entire area of the first conductive portion and the second conductive portion in each pixel. 6. Organic electroluminescence device. 6. The device according to claim 1, wherein the second conductive portion and the second electrode are electrically connected through a contact hole penetrating an insulating layer interposed therebetween. 2. The organic electroluminescence device according to item 1 . An electronic apparatus comprising the organic electroluminescence device according to any one of claims 1 to 6 .

Images