KR102578834B1 - Organic Light Emitting Display Device - Google Patents

Abstract

The present invention relates to an organic light emitting display device further comprising an auxiliary wiring to lower the resistance of a second electrode covering a plurality of sub-pixels, thereby improving electrical connection between the second electrode and the auxiliary wiring. , an auxiliary wiring connected to a portion of the lower side of the second electrode, and an interlayer insulating stack having an undercut shape on the inside of a connection portion between the auxiliary wiring and the second electrode, through which the auxiliary wiring is formed at the undercut bottom of the second electrode. Connected to wiring to lower electrical resistance.

Description

Organic Light Emitting Display Device

The present invention relates to an organic light emitting display device, and in particular, an organic light emitting display device further comprising an auxiliary wiring to lower the resistance of a second electrode covering a plurality of sub-pixels, thereby improving electrical connection between the second electrode and the auxiliary wiring. It's about.

As the information society develops, the demand for display devices for displaying images is increasing in various forms, and in recent years, liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting devices have been developed. Various display devices, such as OLED (Organic Light Emitting Display Device, or Organic Electroluminescence Display Device), are being used. These various display devices include display panels corresponding to them.

Among these, the organic light emitting display device is a self-luminous device that does not require a separate light source unit, which is advantageous for slimming or being flexible, and also has the advantage of good color purity.

Such an organic light emitting display device includes an organic light emitting diode and emits light. The organic light-emitting diode (OLED) includes two different electrodes and a light-emitting layer between them. When electrons generated from one electrode and holes generated from the other electrode are injected into the light-emitting layer, the injected electrons and Holes combine to generate excitons, and light is emitted when the generated aciton falls from the excited state to the ground state.

Among these organic light emitting display devices, an active type organic light emitting display device includes organic light emitting diodes individually in a plurality of pixels on a matrix defined on a substrate, and includes a driving thin film transistor in each pixel to control the organic light emitting diodes. It is said that

In the active type organic light emitting display device, the organic light emitting diode includes first and second electrodes facing each other and an organic light emitting layer between them, where the first electrode is patterned for each pixel, and the second electrode is connected to a plurality of pixels. It is formed as one piece in a shape that covers.

Below, we will look at problems with conventional organic light emitting display devices.

Figure 1 is a graph measuring the luminance change from one side to the opposite side between one side and the opposite side in a conventional organic light emitting display device.

As shown in Figure 1, the conventional organic light emitting display device has a rectangular shape in plan, and when measuring the change in luminance from one side to the opposite side, the luminance is not uniform, and the luminance is lowest in the center between one side and the opposite side. It was observed that the luminance increases towards the outskirts, that is, closer to one side or the opposite side. This means that luminance gradually decreases from the outskirts to the center.

As a result of analyzing the cause of this luminance non-uniformity, one reason is that in an organic light emitting display device, a second electrode (upper electrode) of the organic light emitting diode is formed to cover a plurality of pixels, and the second electrode has a high resistance due to the nature of the material. point was pointed out. More specifically, while the constant voltage or ground voltage is supplied to the second electrode at the outer part, it becomes farther from the voltage supply towards the center, and thus the resistance increases from the outer part to the central part. This is because voltage stability deteriorates. Therefore, as shown in Figure 1, a difference in luminance between regions occurs.

Additionally, in display devices, viewers are sensitive to differences in luminance when they occur, so improvements are required.

The present invention is intended to solve the above-mentioned problems, and provides an organic light emitting display device further provided with an auxiliary wiring to lower the resistance of a second electrode covering a plurality of sub-pixels, thereby improving the electrical connection between the second electrode and the auxiliary wiring. The purpose is to provide.

In order to achieve the above object, the organic light emitting display device of the present invention includes an auxiliary wiring connected to a lower part of the second electrode at a node located in a non-emission portion, and corresponding to the first node and the second node, respectively. It has a first contact hole and a second contact hole exposing a part of the driving thin film transistor and the auxiliary wiring, is located between the layers of the driving thin film transistor and the first electrode, and has an undercut shape on the inside of the second contact hole. It includes an interlayer insulating stack having.

In one embodiment for this purpose, a display area in which sub-pixels including a light-emitting part and non-emission parts surrounding the light-emitting part are arranged in a matrix, a substrate having an outer area surrounding the display area, and a display device provided in each sub-pixel on the substrate. A driving thin film transistor, a first electrode connected to the driving thin film transistor at a first node and covering the light emitting unit, a second electrode located over the entire area of the display area, and an organic light emitting layer between the first and second electrodes. An organic light emitting diode comprising an auxiliary wiring connected to a lower portion of the second electrode at a second node located in the non-light emitting portion, and a portion of a driving thin film transistor corresponding to the first node and the second node, respectively. and an interlayer insulating stack having a first contact hole and a second contact hole exposing the auxiliary wiring, located between layers of the driving thin film transistor and the first electrode, and having an inner portion of the second contact hole having an undercut shape. It can be included.

Here, the interlayer insulating stack may include a protective film and an overcoat layer sequentially stacked on the driving thin film transistor, excluding the first and second contact holes.

Preferably, the overcoat layer protrudes from the protective film toward the center of the second contact hole on the inner side of the second contact hole.

Also, in the second contact hole, the organic light-emitting layer may not be located on an inner portion of the protective film covered by the overcoat layer and a top edge of the auxiliary wiring.

Additionally, in the second contact hole, an inner portion of the protective film covered by the overcoat layer and a top edge of the auxiliary wiring may be in direct contact with the second electrode.

The non-emission portion excluding the second contact hole may further include a bank between layers between the organic light emitting layer and the first electrode. At this time, the organic light emitting layer is preferably located on a bank around the second contact hole and an exposed upper surface of the interlayer insulating stack, and is cut off from the undercut interlayer insulating stack.

Meanwhile, the overcoat layer and the protective film may have different diameters at the interface where they contact each other in the second contact hole.

In the second contact hole, the protective film has a larger first diameter among the overcoat layer and the protective film at an interface in contact with each other, and the organic light-emitting layer may be located only on the upper surface of the auxiliary wiring within the second diameter of the overcoat layer. .

The second electrode extends the organic light emitting layer on the upper surface of the auxiliary wiring to cover the first diameter of the second contact hole, passing through the inner portion of the overcoat layer and the protective film where the organic light emitting layer is cut off, in the second contact hole. It covers and can directly contact the upper surface of the auxiliary wiring around the organic light emitting layer.

Meanwhile, an interlayer transparent electrode film between the protective film and the overcoat layer may be further included.

In this case, the second electrode is in contact with the transparent electrode film on the inner side of the second contact hole, the second electrode is in contact with the side wall of the protective film, and the auxiliary wiring is directly on the auxiliary wiring covered by the overcoat layer. You can access it.

Additionally, the first electrode may be a reflective metal, and the second electrode and the transparent electrode film may be the same transparent electrode.

Additionally, the auxiliary wiring may be located on the same layer as one electrode forming the driving thin film transistor.

The overcoat layer includes a first layer having a step portion in an area that overlaps the auxiliary wiring and does not overlap the protective film, and a second layer overlapping the step portion of the first layer on the first layer. , the second contact hole may have an increasingly larger diameter as it goes from the lower surface of the first layer to the upper surface of the second layer.

And, in the first contact hole, the first layer has a first hole exposing one electrode of the driving thin film transistor, and is connected to one electrode of the driving thin film transistor through the first hole to form the first layer. It may include a connection electrode located to a portion of the upper portion, and a first electrode directly connected to the connection electrode and located on the second layer. Here, in the inner portion of the second contact hole, the bank may be located only on the second layer surface.

The protective film may have a reverse taper or a positive taper on the inner side of the second contact hole.

Alternatively, the protective film may be made of two layers of inorganic films with different etch rates.

The overcoat layer may have a step on its upper surface where the thickness becomes thinner as the non-emission portion approaches the second contact hole.

Meanwhile, an auxiliary dummy pattern may be further included between layers within the second contact hole between the auxiliary wiring and the organic light emitting layer. In this case, the auxiliary dummy pattern directly contacts the inner side of the second contact hole and the upper surface of the auxiliary wiring, and the second electrode may cover the organic light-emitting layer on the upper surface of the auxiliary wiring.

The organic light emitting display device and its manufacturing method of the present invention have the following effects.

In the organic light emitting display device and its manufacturing method according to the present embodiments, the area where the overcoat layer and the auxiliary electrode overlap is wider than the area where the overcoat layer and the auxiliary electrode overlap, so that the auxiliary electrode and There is an effect that the second electrode of the organic light emitting diode can be sufficiently contacted.

In addition, the organic light emitting display device and its manufacturing method according to the present embodiments have the effect of simplifying the process by forming the overcoat layer and the protective film with one mask.

1 is a graph measuring the luminance change from one side to the opposite side between one side and the opposite side in a conventional organic light emitting display device.
Figure 2 is a schematic block diagram showing the organic light emitting display device of the present invention.
Figure 3 is a circuit diagram of each sub-pixel in Figure 2
Figure 4 is a plan view showing each sub-pixel of Figure 2
FIG. 5 is a cross-sectional view taken along lines I to I of FIG. 4 according to the first embodiment of the organic light emitting display device of the present invention.
Figure 6 is an enlarged cross-sectional view of the contact part of the non-emitting part of Figure 5
7 to 10 are cross-sectional views showing the process of forming an overcoat layer and a protective film according to the first embodiment of the present invention.
FIG. 11 is a cross-sectional view taken along lines I to I of FIG. 4 according to a second embodiment of the organic light emitting display device of the present invention.
Figure 12 is an enlarged cross-sectional view of the non-light-emitting part of Figure 11
13 is a cross-sectional view of a second contact hole according to the third embodiment of the organic light emitting display device of the present invention.
Figure 14 is a modified example of the third embodiment of the present invention
15A to 15C are cross-sectional views showing the manufacturing process of a modified example of the third embodiment of the present invention.
Figure 16 is an SEM diagram of the interlayer insulation stack when applying the third embodiment of the present invention.
17A and 17B are cross-sectional process views showing a method of manufacturing an interlayer insulation stack when applying the fourth embodiment of the present invention.
FIG. 18 is a cross-sectional view taken along lines I to I' of FIG. 4 according to the fourth embodiment of the organic light emitting display device of the present invention.
Figure 19 is a cross-sectional view showing the contact part of the non-emitting part of the light emitting part of Figure 18
20 to 22 are plan views showing the arrangement relationship between sub-pixels and auxiliary wiring in the organic light emitting display device of the present invention.
Figure 23 is a graph measuring the luminance change from one side to the opposite side between one side and the opposite side in the organic light emitting display device of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The embodiments introduced below are provided as examples so that the idea of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numerals refer to like elements throughout the specification.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to complete the disclosure of the present invention and are within the scope of common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of explanation.

When an element or layer is referred to as another element or “on” or “on” it includes not only those directly on top of another element or layer, but also all cases where there is another layer or element in between. do. On the other hand, referring to an element as “directly on” or “directly on” indicates that there is no intervening element or layer.

Spatially relative terms such as “below, beneath,” “lower,” “above,” and “upper” refer to one element or component as shown in the drawing. It can be used to easily describe the correlation with other elements or components. Spatially relative terms should be understood as terms that include different directions of the element during use or operation in addition to the direction shown in the drawings. For example, if an element shown in the drawings is turned over, an element described as “below” or “beneath” another element may be placed “above” the other element. Accordingly, the illustrative term “down” can include both downward and upward directions.

The terminology used herein is for the purpose of describing embodiments and is therefore not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprise” and/or “comprising” refers to the presence of one or more other components, steps, operations and/or elements. or does not rule out addition.

Figure 2 is a schematic block diagram showing the organic light emitting display device of the present invention, and Figure 3 is a circuit diagram of each sub-pixel of Figure 2. Additionally, Figure 4 is a plan view showing each sub-pixel of Figure 2.

First, in order to understand the configuration of the cross-sectional view described below, spatial division and region definition of the organic light emitting display device of the present invention will be explained through FIGS. 2 to 4.

2 to 4 , the organic light emitting display device 10 of the present invention includes a polygonal, preferably rectangular, substrate 100 and includes components on the substrate 100.

Additionally, the substrate 100 is largely divided into a display area AA in the center and a non-display area outside the display area AA. In the display area AA, sub-pixels SP, each including an emitting part EA and a non-emitting part NEA surrounding it, are arranged in a matrix.

The sub-pixel (SP) is divided into a gate line (GL) and a data line (DL) that intersect each other. In addition, within the display area AA, a driving voltage line VDDL is further provided to which a driving voltage is applied in the same direction as the data line to drive the pixel circuit PC provided in each sub-pixel SP. , the driving voltage line is connected to a driving thin film transistor (D-Tr) that is part of the pixel circuit (PC).

Referring to FIG. 3, when describing the pixel circuit (PC) connected to the lines, the pixel circuit (PC) includes a switching thin film transistor (S-) provided at the intersection of the gate line (GL) and the data line (DL). Tr), a driving thin-film transistor (D-Tr) provided between the switching thin-film transistor (S-Tr) and the driving voltage line (VDDL), an organic light-emitting diode (OLED) connected to the driving thin-film transistor (D-Tr), and the driving It includes a storage capacitor (Cst) provided between the gate electrode and drain electrode (or source electrode) of the thin film transistor (D-Tr).

Here, the switching thin film transistor (S-Tr) is formed in the area where the gate line (GL) and the data line (DL) intersect and functions to select the corresponding sub-pixel, and the driving thin film transistor (D-Tr) Functions to drive the organic light emitting diode (OLED) of the sub-pixel selected by the switching thin film transistor (S-Tr).

Additionally, the outer area includes a gate driver (GD) that supplies a scan signal to the gate line (GL) and a data driver (DD) that supplies a data signal to the data line (DL). In addition, the driving voltage line VDDL may be provided with a first power source VDD in the outer area to receive a driving voltage, or may receive a driving voltage through a data driver DD.

Here, the gate driver (GD) and data driver (DD)/first power source (VDD) may be formed by being built directly into the outer area of the substrate 100 when forming a thin film transistor in the display area, or may be formed by being built into the substrate 100. It may also be done by attaching a separate film or printed circuit board shape to the outer area of (100). In all cases, this circuit driver is provided outside the display area, and for this purpose, the display area AA is defined inside the edge of the substrate 100.

Additionally, the gate driver (GD) sequentially supplies scan signals to the plurality of gate lines (GL). For example, the gate driver (GD) is a control circuit that supplies scan signals to a plurality of gate lines (GL) in response to control signals supplied from a timing controller (not shown).

Additionally, the data driver DD supplies a data signal to selected data lines DL1 to DLm among the data lines DL in response to a control signal supplied from an external source such as a timing controller (not shown). The data signal supplied to the data lines DL1 to DLm is supplied to the sub-pixel SP selected by the scan signal every time a scan signal is supplied to the gate lines GL to GLn. Through this, the sub-pixel SP charges a voltage corresponding to the data signal and emits light with a corresponding luminance.

Meanwhile, the substrate 100 may be an insulating substrate made of plastic, glass, ceramic, etc. If the substrate 100 is made of plastic, it may be slim and flexible. However, the material of the substrate 100 is not limited to this, and may include metal and further include an insulating buffer layer on the side where the wiring is formed.

Additionally, the sub-pixels (SP) may be defined as a pixel as a set of a plurality of sub-pixels, for example, 3 or 4 sub-pixels, each emitting light of different colors.

This sub-pixel (SP) refers to a unit in which a specific type of color filter is formed or an organic light emitting diode can emit a special color without forming a color filter. Colors defined in sub-pixels may include red (R), green (G), blue (B), and optionally white (W), but the present invention is not limited thereto.

The organic light emitting diode (OLED) is connected to a driving thin film transistor (D-Tr) at a first node (A), and includes a first electrode provided in each sub-pixel, a second electrode facing the first electrode, and It includes an organic light-emitting layer between the first and second electrodes.

Meanwhile, the organic light emitting display device 10 has top emission, bottom emission, and dual emission methods. Here, no matter which light emitting method is selected, in large-area display panels where the number of display panels is increasing, a voltage drop in the second electrode may occur in the process of forming the second electrode of the highly resistive organic light-emitting diode on the front surface of the display area. , in the present invention, to solve this problem, an auxiliary electrode or auxiliary wiring 130 is provided in a non-light emitting part, as shown in FIG. 3.

Here, the auxiliary wiring 130 is made of the same layer of metal as the data line DL, and is provided with a contact portion (CA) between the second electrodes, so that the second electrode and the auxiliary wiring 130 with good conductivity are formed. By connecting at an individual sub-pixel or pixel, the resistance of the second electrode is lowered in the direction in which the auxiliary wire 130 travels, thereby preventing the voltage drop of the second electrode from gradually worsening from the edge to the center. there is.

In the illustrated example, the auxiliary wiring 130 includes, but is not limited to, a first wiring 131 in the gate line GL direction and a second wiring 132 in the data line DL direction. It is also possible to place bars in only one direction.

Meanwhile, as mentioned above, the auxiliary wiring 130 is patterned together on the same layer as the data line DL, and is made of a single layer of Cu, Mo, Al, Ag, and Ti or a multiple layer of a combination thereof. It is connected to the second electrode at the second node (B) and functions to lower the resistance of the second electrode.

Hereinafter, the embodiments described later will be described with a focus on a top-emitting organic light emitting display device. However, the embodiments of the present invention are not limited to the top emitting display device, and are not limited to the structure of all display devices that prevent the voltage drop of the cathode electrode. It can be applied.

The embodiments described below all include a display area (AA) in which the sub-pixels (SP) including the emitting area (EA) and the surrounding non-emitting area (NEA) are arranged in a matrix, and an outline surrounding the display area (AA). A substrate 100 having a region, a driving thin film transistor (D-Tr) provided in each sub-pixel (SP) on the substrate, and the driving thin film transistor (D-Tr) are connected at a first node (A), The first electrode 120 covering the light emitting portion EA, the second electrode 122 located over the entire area of the display area AA, and the interlayer between the first and second electrodes 120 and 122. An organic light emitting diode (OLED) including an organic light emitting layer 121, and an auxiliary wiring 130 connected to a lower portion of the second electrode 122 at a second node B located in the non-emission area (NEA). ), and a first contact hole 1800a exposing a portion of the driving thin film transistor (D-Tr) and the auxiliary wiring 130 corresponding to the first node (A) and the second node (B), respectively. 2 It has a contact hole 1800b, is located between the layers of the driving thin film transistor (D-Tr) and the first electrode 120, and the inner part of the second contact hole 1800b has an undercut shape. It includes an interlayer insulating stack 1800 having.

Hereinafter, an organic light emitting display device and a method of manufacturing the same according to various embodiments of the present invention will be described with specific reference to cross-sectional drawings.

*First Embodiment*

FIG. 5 is a cross-sectional view showing the contact portion of the light-emitting portion and the non-emission portion of FIG. 4 according to the first embodiment of the organic light emitting display device of the present invention, and FIG. 6 is an enlarged cross-sectional view of the contact portion of the non-emission portion of FIG. 5.

5 and 6, the organic light emitting display device according to the first embodiment of the present invention has a sub-pixel (see SP in FIG. 2) including an emitting area (EA) and a non-emitting area (NEA) surrounding it in a matrix. A substrate 100 having a vertically arranged display area (see AA in FIG. 2) and an outer area surrounding the display area AA, and a driving thin film transistor D provided in each sub-pixel SP on the substrate. -Tr), and a first electrode 120 connected to the driving thin film transistor (D-Tr) at the first node (A) and covering the light emitting portion (EA), in the entire area of the display area (AA) An organic light emitting diode (OLED) including a second electrode 122 positioned across and an organic light emitting layer 121 between the first and second electrodes 120 and 122, and a second light emitting diode (OLED) located in the non-light emitting area (NEA). At the second node (B), an auxiliary wiring 130 connected to a lower part of the second electrode 122, and a driving thin film transistor (D) corresponding to the first node (A) and the second node (B), respectively. -Tr) and a first contact hole 1800a and a second contact hole 1800b exposing a portion of the auxiliary wiring 130, and the driving thin film transistor (D-Tr) and the first electrode 120. It is located between the layers and includes an interlayer insulating stack 1800 having an undercut shape on the inner side of the second contact hole 1800b.

First, the driving thin film transistor (D-Tr) is formed on the active layer 102 on the substrate 100 and the gate insulating film 105 on a portion of the active layer 102. It includes a source electrode 106a and a drain electrode 106b respectively connected to both sides of the formed gate electrode 103 and the active layer 102.

Additionally, the source electrode 106a and the drain electrode 106b are disposed on the same layer as the auxiliary wiring 130. The auxiliary wiring 130 must be electrically connected to the second electrode 122 and is electrically separated from the source/drain electrodes 106a/106b of the driving thin film transistor (D-Tr).

Meanwhile, the auxiliary wiring 130 may be provided on the same layer as the gate electrode 103, which is another electrode of the driving thin film transistor (D-Tr). Even in this case, the auxiliary wiring 130 maintains electrical separation from the gate electrode 103 or the gate line.

On the active layer 102, there is a first interlayer insulating film 104 that covers the active layer 102 and the gate electrode 105 except for the connection portion between the source electrode 106a and the drain electrode 106b.

Here, the interlayer insulation stack 1800 includes a protective film 107 and an overcoat layer 108 that are sequentially stacked on the driving thin film transistor, excluding the first contact hole 1800a and the second contact hole 1800b. can do.

The protective film 107 and the overcoat layer 108 are an inorganic film and an organic film, respectively. The protective film 107 is formed to a thickness of several thousand Å along the irregularities or steps of the lower layer surface, and the overcoat layer 108 is the It is thicker than the protective film 107 and is formed to be able to smooth out irregularities on the surface of the lower layer.

Here, on the inner side of the second contact hole 1800b, the overcoat layer 108 protrudes from the protective film 107 toward the center of the second contact hole 1800b, thereby forming a protective film 107 from the overcoat layer 108. ) enters to form an undercut shape that relatively obscures the auxiliary wiring 130 in the non-overlapping area between the overcoat layer 108 and the protective film 107.

As such, the reason for providing an undercut in the interlayer insulating stack 1800 is to ensure normal electrical connection between the auxiliary wiring 130 and the second electrode 122.

In more detail, after the first electrode 120 is formed by patterning using a mask, the organic light-emitting layer 121 is deposited and the second electrode 122 is formed without a separate exposure process. In this process, , First, the organic light-emitting layer 121 is formed on the auxiliary wiring 130, and in the present invention, the purpose is to define a region where the organic light-emitting layer 121 is not formed through an undercut structure.

The organic light-emitting layer 121 does not use a photoresist to distinguish patterns in a general exposure process, but supplies vaporized organic material from an organic material source and passes it through the hole of a non-adhesive deposition mask with the substrate to accumulate organic material on the substrate. It is formed by In this process, the vaporized organic matter is supplied in a vertical direction, and does not accumulate on the part hidden by the undercut of the interlayer insulating stack 1800, but only accumulates on a portion of the exposed upper surface of the auxiliary wiring 130.

On the other hand, the second electrode 122 to be formed is deposited using a sputtering method. In sputtering, metal particles are randomly supplied, so they are deposited in a diffuse manner even in areas hidden by undercuts, and the second electrode 122 is deposited on the organic light-emitting layer 121. ), as well as the upper edge of the auxiliary wiring 130 obscured by the undercut shape, and can also be deposited on the side of the protective film 107.

That is, in the contact portion CA of the auxiliary wiring 130 of the present invention, the organic light-emitting layer has a disconnected shape at the undercut portion, and the second electrode 122 has a continuous shape, so that the auxiliary wiring 130 and the second electrode ( 122) is properly connected, so that the auxiliary wiring 130 can normally prevent the voltage drop of the second electrode 122.

Meanwhile, in the interlayer insulating stack 1800, the protective film 107 located on the lower side may have a positive taper, a reverse taper, or a vertical taper, as shown on the inner side of the second contact hole 1800b. You may. If the overcoat layer 108 enters the second contact hole 1800b relatively from the inner side of the second contact hole 1800b, the second electrode 122 and the auxiliary wiring 130 expected to be undercut in the interlayer insulating stack. You will be able to obtain connection characteristics with . In addition, since the protective film 107 is made of a different material from the overcoat layer 108, even if it is patterned using the same mask as the overcoat layer 108, different etch characteristics occur at the interface of the overcoat layer 108. It can be patterned to have a diameter.

In the above structure, in the second contact hole 1800b, the organic light-emitting layer 121 is located on the inner side of the protective film 107 covered by the overcoat layer 108 and the upper edge of the auxiliary wiring 130. won't do it.

Meanwhile, the non-emission area (NEA) excluding the second contact hole 1800b may further include a bank 150 between the organic light emitting layer 121 and the first electrode 120.

Generally, the bank 150 is shaped to have an opening only in the light emitting part EA for each sub-pixel SP, but in the present invention, it has an opening in the area of the second contact hole 1800b, and the auxiliary wiring ( 130) is exposed.

At this time, the organic light emitting layer 122 located within the second contact hole 1800b is located on the exposed upper surface of the bank 150 around the second contact hole 1800b and the interlayer insulating stack 1800, , becomes disconnected from the undercut interlayer insulation stack 1800.

In addition, in the second contact hole 1800b, at the interface where the overcoat layer 108 and the protective film 107 are in contact, the protective film 107 has a larger first diameter, and the organic light-emitting layer 121 has, It may be located only on the top surface of the auxiliary wiring 130 within the second diameter of the overcoat layer 108.

The second electrode 122 passes through the inner part of the overcoat layer 108 and the protective film 107 where the organic light-emitting layer 121 is cut off in the second contact hole 1800b, and is connected to the second contact hole 1800b. ), it covers the organic emission layer 121 on the upper surface of the auxiliary wiring 130 and can directly contact the upper surface of the auxiliary wiring 130 around the organic emission layer 121.

As shown in FIG. 6, the overcoat layer 180 includes a first layer 108b that overlaps the auxiliary wiring 130 and has a step in an area that does not overlap the protective film 107. ) on the second layer (108a) overlapping the step portion of the first layer, and the second contact hole (1800b) is formed on the lower surface of the first layer (108b). It can have increasingly larger diameters toward the upper surface of .

And, as shown in FIG. 5, the maximum width (X) of the second layer 108a may be narrower than the maximum width (Y) of the second region 108b. That is, the maximum width of the second layer 108a and the first layer 108b of the overcoat layer 108 are different from each other, so that the overcoat layer 108 has at least one step on the inner side of the second contact hole 1800b. can be provided.

Meanwhile, in FIG. 6, the maximum width of the second layer 108a of the overcoat layer 108 is wider than the maximum width of the first layer 108b, so that the second layer of the overcoat layer 108 in the second contact hole 1800b The area where the first layer 108b of the overcoat layer 108 located below and the auxiliary wire 130 overlap may be wider than the area where 108a and the auxiliary wire 130 overlap.

In addition, the area where the first layer 108b of the overcoat layer 108 and the auxiliary wiring 130 overlap in the second contact hole 1800b is the protective film 107 and the auxiliary wiring disposed below the first layer 108b. (130) may be wider than the overlapping area.

That is, a portion of the upper surface of the auxiliary wiring 130 may overlap the second layer 108a, the first layer 108b, and the protective film 107 of the overcoat layer 108, of which the overcoat layer 108 The overlapping area between the first layer 108b and the auxiliary wiring 130 may be the widest. Meanwhile, the organic light emitting layer 121 may be disposed on the bank 150 and the auxiliary wiring 130. In detail, the organic light emitting layer 121 may be disposed on the top surface of the bank 150 and a portion of the top surface of the auxiliary wiring 130 vertically exposed in the interlayer insulating stack 1800. That is, the organic light emitting layer 121 may be disposed excluding the edge of the top surface of the auxiliary wiring 130.

Meanwhile, the organic light-emitting layer 121 may be formed by a deposition or coating method that has straight-line properties. For example, it can be formed by evaporation method. Accordingly, the organic light emitting layer 121 may not be formed on the auxiliary wiring 130 that overlaps the first layer 108b of the overcoat layer 108 on the undercut side.

In detail, the edge of the top surface of the auxiliary wiring 130 may be obscured by the first layer 108b of the overcoat layer 108. Accordingly, the organic light-emitting layer 121 formed by a deposition or coating method having linearity may be formed on the first region 108b of the overcoat layer 108 and the upper surface of the first layer 108b, but the overcoat layer 108 The organic light emitting layer 121 may not be formed on a portion of the upper surface of the auxiliary wiring 130 that is obscured by the first layer 108b.

That is, an area 121a where the organic light-emitting layer 121 is not placed may occur on a portion of the upper surface of the auxiliary wiring 130 that is covered by the first layer 108b of the overcoat layer 108.

In other words, the organic light-emitting layer 121 cannot penetrate into the part of the upper surface of the auxiliary wiring 130 that is covered by the first layer 108b of the overcoat layer 108, thereby forming an organic layer on the auxiliary wiring 130. An area 121a where the light emitting layer 121 is not placed may occur.

In addition, the second electrode 122 of the organic light emitting diode is disposed on the organic light emitting layer 121 and the area 121a where the organic light emitting layer 121 is not disposed. Here, the second electrode 122 of the organic light emitting diode may be formed using a sputtering method. This method has excellent step coverage, so the second electrode 122 can be formed so that no unplaced areas occur even in a structure with a step.

Accordingly, the second electrode 122 may be disposed on a portion of the upper surface of the auxiliary wiring 130 that is obscured by the first layer 108b of the overcoat layer 108. That is, the second electrode 122 and the auxiliary wiring 130 may be placed in contact with a portion of the upper surface of the auxiliary wiring 130 that is covered by the first layer 108b of the overcoat layer 108. In other words, the second electrode 122 and the auxiliary wiring 130 may be placed in contact with the area 121a where the organic light emitting layer 121 is not disposed, which is provided in the second contact hole 1800b.

That is, the auxiliary wiring 130 and the second electrode 122 can be electrically connected in a sufficiently stable manner in the area 121a where the organic light emitting layer 121 is not disposed, which is provided in the second contact hole 1800b. Through this, the resistance of the second electrode 122 can be lowered.

Meanwhile, the gate electrode 103 of the driving thin film transistor (D-Tr) may be formed by laminating at least one alloy made of Cu, Mo, Al, Ag, Ti, or a combination thereof. However, the material constituting the gate electrode 103 is not limited to this and can be formed of commonly used gate electrode and gate line materials. In addition, although it is composed of a single metal layer in the drawing, in some cases, it may be composed by stacking at least two or more metal layers.

In addition, the data line DL, driving voltage line VDDL, and source/drain electrodes 106a and 106b are formed by stacking at least one alloy composed of Cu, Mo, Al, Ag, Ti, or a combination thereof. can be formed. However, it is not limited to these materials, and any metal, alloy thereof, or laminate thereof that can maintain low resistance can be replaced.

Meanwhile, the above-described organic light-emitting layer 121 is shown as a single layer in the drawing, but the organic light-emitting layer 121 according to this embodiment is not limited to this and may be composed of multiple layers. For example, the organic light emitting layer 121 includes a hole injection layer (HIL), a hole transport layer (HTL), an emitting material layer (EML), an electron transport layer (ETL), and It may be composed of multiple layers including an electron injection layer (EIL). At this time, at least one of the hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer of the organic light emitting layer 121 may be disposed on the auxiliary wiring 130.

In addition, symbol 101, which is not described in the above cross-sectional view, is a buffer layer, which is provided below the active layer 102 to prevent impurities from being transferred to the substrate 100 when the active layer 102 is crystallized. It has a preventive function. In some cases, it may be omitted.

Hereinafter, a method of forming a structure including a step portion of the overcoat layer 108 shown in FIGS. 5 and 6 will be described.

7 to 10 are cross-sectional views showing the process of forming an overcoat layer and a protective film according to the first embodiment of the present invention.

Meanwhile, the process of forming the overcoat layer 108 having at least one step and the protective film 107 disposed below the overcoat layer 108 is as follows.

7 to 10, a protective film material 207 is formed on a substrate 100 divided into a non-emitting part (NEA) including an emitting part (EA) and a contact part (CA), and the protective film material 207 ) to form an overcoat layer material 208 on it. Then, the mask 500 is placed opposite the substrate 100.

At this time, the mask 500 may include a transparent portion 501, a first semi-transparent portion 502, a second semi-transparent portion 503, and a blocking portion 504. At this time, the transmissive part 501 is an area that transmits light 600, and the first semi-transmissive part 502 and the second semi-transmissive part 503 are areas that transmit less light than the transmissive part 501. Here, the second semi-transmissive portion 503 is an area that transmits less light than the first semi-transmissive portion 502. And, the blocking portion 504 is an area that blocks light.

Afterwards, light 600 is irradiated to reach the overcoat layer material 208 through the mask 500. At this time, the overcoat layer material 208 may be made of a material that hardens when light 600 is irradiated.

Meanwhile, the overcoat layer material 208 is not limited to this, and may be made of a material that hardens areas that are not irradiated with light 600. In this case, the pattern of the mask 500 may be manufactured in the opposite way. However, for convenience of explanation, the following description will focus on an embodiment in which the overcoat layer material 208 is made of a material that hardens when irradiated with light 600.

Accordingly, all of the overcoat layer material 208 disposed in the area corresponding to the transparent portion 501 of the mask 500 is cured. In addition, the overcoat layer material 208 disposed in the area corresponding to the first semi-transmissive portion 501 of the mask 500 is the overcoat layer material 208 disposed in the area corresponding to the transparent portion 501 of the mask 500. ) is less hardened than

In addition, the material 208 of the overcoat layer disposed in the area corresponding to the second semi-transmissive portion 502 of the mask 500 is the overcoat layer disposed in the region corresponding to the first semi-transparent portion 501 of the mask 500. It hardens less than material 208. Additionally, the overcoat layer material 208 disposed in the area corresponding to the blocking portion 504 of the mask 500 may not be cured.

Afterwards, the overcoat layer material 208 irradiated with light 600 is developed. At this time, the first material 208a of the overcoat layer disposed in the area corresponding to the transparent portion 501 of the mask 500, and the overcoat layer disposed in the region corresponding to the first transparent portion 502 of the mask 500. The second material 208b and the third material 208c of the overcoat layer disposed in the area corresponding to the second transparent portion 503 of the mask 500 remain.

Here, the height of the first material 208a of the overcoat layer may be higher than the height of the second material 208b of the overcoat layer. Additionally, the height of the second material 208b of the overcoat layer may be higher than the height of the third material 208c of the overcoat layer. Additionally, the overcoat layer material 208 disposed in the area corresponding to the blocking portion 504 of the mask 500 may be removed through the development process.

In areas where the overcoat layer material 208 has been removed, the protective film material 207 is exposed. The exposed protective film material 207 is removed by wet etching. At this time, the area from which the protective layer material 207 has been removed may be wider than the area from which the overcoat layer material 208 has been removed due to over-etching. In particular, in the second contact hole 1800b, the protective film material 207 formed in the area corresponding to the blocking portion 504 of the mask 500 and a portion of the area corresponding to the first semi-transmissive portion 503 may be removed. . In this way, the protective film 107 can be formed.

For this reason, as shown in FIG. 9 , one side of the third material 208c of the overcoat layer may be formed to protrude more than one side of the protective film 107 . Meanwhile, the areas from which part of the overcoat layer material 208 and part of the protective film material 207 have been removed may be contact holes for contact between the first electrode and the drain electrode in the non-light emitting area (NEA), respectively, and the non-light emitting area (NEA) may be a contact hole for contacting the first electrode and the drain electrode. It may correspond to the area where the auxiliary electrode and the second electrode of the organic light emitting diode are in contact with the second contact hole 1800b of the NEA).

Afterwards, the third material 208c of the overcoat layer is removed by ashing, thereby exposing a portion of the protective film 107 as shown in FIG. 6 . In this process, a portion of the first material 208a and the second material 208b of the overcoat layer may be ashed, lowering the height compared to before the ashing process.

Through this, the overcoat layer 108 including the second layer 108a and the first layer 108b can be formed. In particular, the second area 108b of the overcoat layer 108 disposed in the second contact hole 1800b may have a larger area overlapping with the substrate than the protective film 107.

In the process of patterning this interlayer insulating stack 1800, as shown in FIG. 5, a second contact hole 1800b is defined in the non-emission part, and at the same time, the drain electrode 106b of the driving thin film transistor (D-Tr) ( Alternatively, a first contact hole 1800a exposing a portion of the upper part of the source electrode-106a is also defined. In the top light emitting method, there is a degree of freedom in not distinguishing between the light emitting part (EA) and the non-light emitting part (NEA) by providing the first contact hole (1800a), but the unevenness of the first contact hole (1800a) creates a flat area. In order to prevent luminance characteristics different from those of the first contact hole 1800a, it may be desirable to provide the first contact hole 1800a in the non-emission area EA.

As described above, the overcoat layer 108 and the protective film 107 can be formed with one mask, which has the effect of simplifying the process. In addition, as described above, by forming the overcoat layer 108 and the protective film 107, the area where one area of the overcoat layer 108 overlaps the substrate in the second contact hole 1800b is wider than that of the protective film 107. can be formed.

Meanwhile, as shown in FIG. 5, the contact portion CA is formed with the first electrode 120 to cover the light emitting portion of the sub-pixel SP, and then formed on the first electrode 120 and the light emitting portion EA. A bank 150 having an opening is formed above the second contact hole 1800b.

Next, the organic light-emitting layer 121 is formed on the light-emitting portion (EA), the upper surface of the bank 150, and the vertically exposed auxiliary wiring 130 of the interlayer insulating stack 1800 of the non-light-emitting portion (NEA). .

Next, a second electrode 122 is formed on the top surface of the organic light-emitting layer 121, the auxiliary wiring 130 exposed in the second contact hole 1800b, and the sidewall of the second contact hole 1800b.

As a result, the second electrode 122 may be formed as one pattern over the display area AA including a plurality of subpixels SP.

*Second Embodiment*

FIG. 11 is a cross-sectional view showing a contact portion of the light-emitting portion and the non-emission portion of FIG. 4 according to a second embodiment of the organic light emitting display device of the present invention, and FIG. 12 is an enlarged cross-sectional view of the non-emission portion of FIG. 11.

The organic light emitting display device according to the second embodiment may include the same components as the previously described embodiment. Descriptions that overlap with the previously described embodiments may be omitted. Additionally, the same components have the same reference numerals.

Referring to FIG. 11, compared to the organic light emitting display device according to the first embodiment, the organic light emitting display device according to the second embodiment has an additional first layer dummy overcoat layer 109, and thus the connection electrode. There is a difference in how the auxiliary dummy pattern 131 and the auxiliary dummy pattern 330 are further arranged.

In detail, a source electrode 106a, a drain electrode 106b, and an auxiliary wiring 130 are disposed on the first interlayer insulating film 104. And, a protective film 107 is disposed on the source electrode 106a, the drain electrode 106b, and the auxiliary wiring 130.

An overcoat layer 108 is disposed on the protective film 107. A connection electrode 131 connected to the drain electrode 106b is disposed on the overcoat layer 108, and an auxiliary dummy pattern 330 is disposed on the auxiliary wiring 130. At this time, the connection electrode 131 and the auxiliary dummy pattern 330 may be made of the same material and may be formed through the same process.

Additionally, a dummy overcoat layer 109 may be disposed on the overcoat layer 108 and the connection electrode 131. At this time, the end of the dummy overcoat layer 109 may be arranged to overlap the end of the first layer 108b of the overcoat layer 108. By disposing the dummy overcoat layer 109 in this way, the upper surface of the substrate 100 can be made more flat.

Additionally, the dummy overcoat layer 109 may not be disposed in the second contact hole 1800b. And, on the upper surface of the dummy overcoat layer 109, a first electrode 220 of an organic light-emitting diode (OLED) is disposed in contact with the connection electrode 131 through the first contact hole 1800a along with the overcoat layer 108. ) is placed. In addition, the bank 150 is disposed in the non-emission area (NEA) excluding a portion of the upper surface of the first electrode 220 and the second contact hole 1800b on the dummy overcoat layer 109.

The organic light emitting layer 121 is disposed on the bank 150, the first electrode 220, and the auxiliary dummy pattern 330. Also, the second electrode 122 of an organic light emitting diode (OLED) is disposed on the organic light emitting layer and the auxiliary wiring 130.

Meanwhile, an auxiliary dummy pattern 330 is disposed on a portion of the upper surface of the auxiliary wiring 130 in the second contact hole 1800b of the organic light emitting display device according to the second embodiment, and the organic light emitting pattern 330 is disposed on the auxiliary dummy pattern 330. A light emitting layer 121 is disposed, and a second electrode 122 of an organic light emitting diode (OLED) is disposed on a portion of the upper surface of the auxiliary wiring 130 and the organic light emitting layer 121. That is, by arranging the auxiliary wiring 130 and the second electrode 122 to be in contact with each other, the resistance of the second electrode 122 can be lowered.

Here, in the first contact hole 1800a, the overcoat layer 108 forms a first hole 108c exposing the drain electrode 106b or the source electrode 106a of the driving thin film transistor (D-Tr). It has a connection electrode 131 connected to the exposed drain electrode 106b or source electrode 106a of the driving thin film transistor through the first hole 108c and located to a part of the upper part of the overcoat layer 108, It may include a first electrode 120 that is directly connected to the connection electrode 131 and located on the dummy overcoat layer 109.

At this time, the bank 150 may be located only on the surface of the dummy overcoat layer 109 inside the second contact hole 1800b.

Examining this configuration in detail through FIG. 12, a protective film 107 is disposed on a portion of the upper surface of the auxiliary wiring 130 in the second contact hole 1800b of the organic light emitting display device according to the second embodiment, and the protective film 107 ) An overcoat layer 108 is disposed on the overcoat layer 108, and a dummy overcoat layer 109 is disposed on the overcoat layer 108. Here, the dummy overcoat layer 109 may be arranged to overlap the upper surface of the stepped portion of the overcoat layer 108.

At this time, the overcoat layer 108 may be divided into a second layer 108a disposed in contact with the dummy overcoat layer 109 and a first layer 108b disposed below the second layer 108a. In the second contact hole 1800b, the first layer 108b of the overcoat layer 108 and the auxiliary wiring 130 overlap the area where the first region 108b of the overcoat layer 108 and the auxiliary wiring 130 overlap. The overlapping area may be wider. Additionally, the area where the first layer 108b of the overcoat layer 108 and the auxiliary wire 130 overlap may be wider than the area where the protective film 107 and the auxiliary wire 130 overlap.

That is, a portion of the upper surface of the auxiliary wiring 130 may overlap the second layer 108a, the first layer 108b, and the protective film 107 of the overcoat layer 108, of which the overcoat layer 108 The overlapping area between the first layer 108b and the auxiliary wiring 130 may be the widest. Meanwhile, an auxiliary dummy pattern 330 may be disposed on a portion of the upper surface of the auxiliary wiring 130.

That is, the maximum width of the auxiliary dummy pattern 330 may be narrower than the maximum width of the auxiliary wiring 130. Through this, the auxiliary dummy pattern 330 may expose a portion of the upper surface of the auxiliary wiring 130. In detail, the auxiliary dummy pattern 330 may not be disposed in an area corresponding to an area where the first layer 108b of the overcoat layer 130 and the auxiliary wiring 130 overlap.

Additionally, the organic light-emitting layer 121 may be disposed on the auxiliary dummy pattern 330. At this time, the organic light emitting layer 121 on the auxiliary dummy pattern 330 may not be disposed in an area corresponding to the area where the first layer 108b of the first overcoat layer 130 and the auxiliary wiring 130 overlap. . In addition, the second electrode 122 of the organic light emitting diode will be disposed in an area corresponding to the area where the first layer 108b of the organic light emitting layer 121 and the first overcoat layer 130 overlaps with the auxiliary wiring 130. You can.

Meanwhile, when the auxiliary dummy pattern 330 is disposed to an area corresponding to the area where the second area 108b of the first overcoat layer 130 and the auxiliary wiring 130 overlap, the first area of the overcoat layer 108 By filling part or all of the space between the layer 108b and the auxiliary wiring 130 with the auxiliary dummy pattern 330, the second electrode 122 is connected to the first layer 108b of the overcoat layer 130 and the auxiliary wiring ( 130), and as a result, it may be difficult for the auxiliary wiring 130 and the second electrode 122 to make contact.

That is, in the organic light emitting display device according to the second embodiment, the auxiliary dummy pattern 330 is disposed only on a portion of the upper surface of the auxiliary wiring 130, thereby facilitating contact between the second electrode 122 and the auxiliary wiring 130. . In addition, in the organic light emitting display device according to the second embodiment, the organic light emitting layer 121 overlaps only a portion of the upper surface of the auxiliary wiring 130, so that the second electrode 122 and the auxiliary wiring 130 can be sufficiently electrically contacted. You can.

*Third Embodiment*

Figure 13 is a cross-sectional view showing a contact portion between the auxiliary wiring of the non-emission portion and the second electrode according to the third embodiment of the organic light emitting display device of the present invention.

As shown in FIG. 13, the organic light emitting display device according to the third embodiment of the present invention has a structure that further includes an interlayer transparent electrode film 420 between the protective film and the overcoat layer.

In this case, the second electrode 122 is in contact with the transparent electrode film 420 on the inner side of the second contact hole 1800b, and the second electrode 122 is in contact with the side wall of the protective film 107 and the The auxiliary wiring 130 may be in direct contact with the auxiliary wiring 130 covered by the overcoat layer 108 .

In this way, the reason for providing the transparent electrode film 420 below the overcoat layer 108 is that the overcoat layer 108 reflows after forming the second contact hole 1800b in the interlayer insulating stack 1800. This is to prevent the pattern from losing its shape and collapsing during the process of applying heat. The transparent electrode film 420 maintains the pattern, and the upper overcoat layer 108 also maintains the pattern on the transparent electrode film 420.

In addition, in the top emission method, the second electrode 122 is made of a transparent electrode, and the transparent electrode film 420 is formed using the same transparent electrode as the second electrode 122, and an overcoat layer ( This is to ensure connection reliability by maintaining the same adhesion at the top and bottom of the 108). At this time, after forming the second electrode 122 at the undercut portion of the interlayer insulating stack, the second electrode of the overcoat layer 108 that entered the undercut portion meets the auxiliary wiring 130 at the edge of the auxiliary wiring 130. At the side wall of the protective film 107, it comes into contact with the transparent electrode film 420 located below the overcoat layer 108, so that conduction is achieved between the auxiliary wiring 130, the second electrode 122, and the transparent conductive film 420. . As a result, the second electrode 122 is connected to the auxiliary wiring 130, thereby lowering the resistance of the second electrode 122.

In this case, the first electrode 120 is a reflective metal, and the second electrode 122 and the transparent electrode film 420 are made of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and Indium Gallium Zinc Oxide (IGZO). ), etc., and can be made of the same material.

Additionally, the auxiliary wiring may be located on the same layer as one electrode forming the driving thin film transistor.

Specifically, the formation method of the third embodiment described above will be examined with reference to FIGS. 5 and 13.

First, an auxiliary wiring 130 is formed in a portion of the non-emission portion on the same layer as the source/drain electrodes 106a and /106b of the driving thin film transistor (D-Tr). The previous process is the same as the previously described embodiments.

Next, a protective film 107 is formed to completely cover the driving thin film transistor (D-Tr) and the auxiliary wiring 130.

Next, a transparent conductive film 420 is formed on the protective film 107, and then an overcoat layer 108 is formed on the transparent conductive film 420.

Next, the overcoat layer 108 is patterned to remove portions corresponding to the first and second contact holes 1800a and 1800b.

The transparent conductive film 108 corresponding to the first and second contact holes 1800a and 1800b is removed by wet etching according to the shape of the overcoat layer 108, and then the overcoat layer 108 is cured.

Next, the lower protective film 107 is patterned by wet etching along the patterned transparent conductive film 108. In this process, the protective film 107, transparent conductive film 420, and overcoat layer 108 of the interlayer insulating stack 1800 have first and second contact holes 1800a and 1800b, respectively, and are made of different materials. As shown in Figure 13, the protective film 107 is patterned to have a relatively wider diameter at the area of the second contact hole 1800b than the transparent conductive film 420, and the transparent conductive film 420 is larger than the overcoat layer 108. It is patterned with a slightly wider diameter.

After forming the interlayer insulating stack 1800 in the above-described manner, a bank (see 150 in FIG. 5) is formed in the non-emission area (NEA) excluding the first and second contact holes 1800a and 1800b. In some cases, the bank 150 may be omitted.

When the bank 150 is omitted, the organic light emitting layer 121 is vertically exposed in the overcoat layer 108 and the second contact hole 1800b, excluding the undercut portion, in the interlayer insulating stack 1800. It is located on the wiring 130, and the sidewall of the protective film 107 and the edge of the auxiliary wiring 130 or the organic light emitting layer 121 in the area hidden by the top of the organic light emitting layer 121 and the undercut portion are not formed. A second electrode 122 is formed on the unused auxiliary wiring 130 . Through this, the resistance of the second electrode 122 is reduced by directly connecting to the auxiliary wiring 130 within the second contact hole 1800b of the second electrode 122.

Figure 14 is a modified example of the third embodiment of the present invention.

Meanwhile, as shown in FIG. 14, the overcoat layer 308 can be further ashed after forming the interlayer insulation stacks 107, 420, and 108 of FIG. 13 to reduce both the thickness and diameter. In this process, the overcoat layer 308 has a larger diameter than the transparent conductive film 420, and in the interlayer insulating stack 2800, the transparent conductive film 420 extends most toward the center of the second contact hole 1800b. It becomes protruding. In this interlayer insulating stack 2800, the second electrode 122 is inserted into the edge of the transparent conductive film 420 and the undercut portion in the second contact hole 1800b and is directly connected to the auxiliary wiring 130, so as to form the same structure as described above. It has an electrical connection effect.

15A to 15C are cross-sectional views showing the manufacturing process of a modified example of the third embodiment of the present invention.

Specifically, in a modified example of the third embodiment of the present invention, as shown in FIG. 15A, the protective film 107 is formed to entirely cover the driving thin film transistor (D-Tr) and the auxiliary wiring 130.

Next, a transparent conductive film 420 is formed on the protective film 107, and then an overcoat layer 108 is formed on the transparent conductive film 420.

Next, the overcoat layer 108 is patterned to remove portions corresponding to the first and second contact holes 1800a and 1800b.

The transparent conductive film 420 corresponding to the first and second contact holes 1800a and 1800b is removed by wet etching according to the shape of the overcoat layer 108, and then the overcoat layer 108 is cured.

Next, the lower protective film 107 is patterned by wet etching along the patterned transparent conductive film 420. In this process, the protective film 107, transparent conductive film 420, and overcoat layer 108 of the interlayer insulating stack 2800 have first and second contact holes 1800a and 1800b, respectively, and are made of different materials. As shown in Figure 13, the protective film 107 is patterned to have a relatively wider diameter at the area of the second contact hole 1800b than the transparent conductive film 420, and the transparent conductive film 420 is larger than the overcoat layer 108. It is patterned with a slightly wider diameter.

The interlayer insulating stack 1800 is formed in the manner described above.

Next, as shown in FIG. 15B, the overcoat layer 108 is ashed to form an overcoat layer 308 with a reduced thickness and diameter. In this case, the thickness of the overcoat layer 308 is reduced in the area of the second contact hole 1800b and the patterned diameter is defined to be larger than that of the transparent conductive film 420, so that the overcoat layer is relatively larger than the transparent conductive film 420. By inserting the layer 308, the transparent conductive film 420 can have a shape that protrudes more than the upper and lower overcoat layers 308 and the protective film 107.

Subsequently, a bank (see 150 in FIG. 5) may be further formed on the overcoat layer 308.

Next, as shown in FIG. 15C, an organic light emitting layer 121 is formed on the top of the auxiliary wiring 130, the light emitting part EA, and the overcoat layer pattern 308. As shown in FIG. 12 , when there is a bank 150, the organic light emitting layer 121 is deposited on the bank 150 on top of the overcoat layer 308.

As shown, when the bank 150 is omitted, the organic light emitting layer 121 is located within the overcoat layer 108 and the second contact hole 1800b, excluding the undercut portion, in the interlayer insulating stack 1800. Located on the vertically exposed auxiliary wiring 130, the upper part of the organic light-emitting layer 121, the sidewall of the protective film 107 in the area hidden by the undercut area, and the edge of the auxiliary wiring 130 (or the organic light-emitting layer) A second electrode 122 is formed on the auxiliary wiring 130 where the auxiliary wiring 121 is not formed. Through this, the auxiliary wiring 130 and the auxiliary wiring 130 are formed within the second contact hole 1800b of the second electrode 122. Direct connection reduces the resistance of the second electrode 122. In addition, the transparent conductive film 420 is laterally connected to the upper second electrode 122, and the second electrode located on the side wall of the lower protective film 107 By connecting to (122), more electrical stability can be obtained.

Figure 16 is an SEM diagram of an interlayer insulation stack when applying the third embodiment of the present invention.

As shown in FIG. 16, after patterning the overcoat layer (OC), the lower transparent conductive film (ITO) and the protective film (PAS) are wet etched according to the shape of the overcoat layer. When forming the protective film (PAS), the protective film (PAS) is wet etched. It was confirmed that after a certain period of time, it maintained a nearly vertical shape, as shown in FIG. 16. In other words, it was confirmed that the overcoat layer (OC) and the transparent conductive film (ITO) and protective film (PAS) underneath it could be patterned in sequence using the same mask.

*Fourth Embodiment*

Figures 17a and 17b are cross-sectional process views showing a method of manufacturing an interlayer insulating stack when applying the fourth embodiment of the present invention.

The fourth embodiment of the present invention shows a method of changing the shape of the lower protective film in an interlayer insulating stack. That is, in the interlayer insulating stack, a method is proposed that has an undercut shape and a reverse taper with a support function for the overcoat layer 108, with the lower protective film being a double layer.

First, as shown in FIG. 17A, a first protective layer 217a and a second protective layer 217b with different etch rates are stacked. Among these, a material with a higher etch rate is applied to the first protective layer 217a.

Next, an overcoat layer material is applied on the second protective layer 217b and then patterned to form an overcoat layer 108.

Using the patterned overcoat layer 108 as a mask, the lower second protective layer 217b has a relatively higher etch rate than the first protective layer 217a and is in contact with the overcoat layer 108. The layer 217b has a diameter substantially similar to that of the overcoat layer 108, but the lower first protective layer 217a has a larger diameter than the second protective layer 217b and the overcoat layer 108. The structure with such a reverse taper prevents the phenomenon in which the overcoat layer 108 has flowability and collapses to cover the undercut when the protective film has a regular taper structure, during the reflow process after forming the bank. There is an advantage to preventing it.

Here, the first and second protective layers 217a and 217b are collectively referred to as the protective film 217, and the first and second protective layers 217a and 217b are made of the same series of materials, but the composite amount is The etching rate can be varied by varying , or this shape can be satisfied by using other inorganic film materials.

Hereinafter, the organic light emitting display device to which the above-described fourth embodiment is applied will be examined together with the light emitting portion (EA) and the contact portion (CA).

FIG. 18 is a cross-sectional view taken along lines I to I' of FIG. 4 according to a fourth embodiment of the organic light emitting display device of the present invention, and FIG. 19 is a cross-sectional view showing a contact portion of the non-emission portion of the light emitting portion of FIG. 18.

18 and 19, the fourth embodiment of the organic light emitting display device of the present invention has the same shape of the light emitting portion EA as the first embodiment described above with reference to FIG. 5.

The difference occurs in the contact portion CA where the auxiliary wiring 130 and the second electrode 122 are connected, and the protective film 207 is formed by stacking materials with different etch rates, as shown in FIGS. 17A and 17B, to form a second contact hole ( 1800b), it had a reverse taper. In this way, after forming the interlayer insulating stack 2800, the first electrode 120 is formed to be connected to the exposed source electrode 106a or the drain electrode 106b through the first contact hole 1800a, At the same time, a contact auxiliary pattern 145 is formed inside the second contact hole 1800b so as to be electrically spaced apart from the first electrode 120. The contact auxiliary pattern 145 is formed not only on the sidewall of the overcoat layer 108 but also on the side of the protective film 107 having a reverse taper and the upper surface of the auxiliary wiring 130 in the second contact hole 1800b.

Then, a bank 150 is formed in the non-emission area (NEA) excluding the first contact hole (1800a) and the second contact hole (1800b). The bank 150 may partially cover the contact auxiliary pattern 145 on the overcoat layer 108 .

In addition, an organic light-emitting layer 121 is formed on the first electrode 120 of the light-emitting part, the top of the bank 150 of the non-emission part, and the exposed auxiliary wiring 130 of the second contact hole 1800b. .

A second electrode 122 is formed on the entire display area including a plurality of subpixels including the organic light emitting layer 121. Here, the second electrode 122 in the second contact hole 1800b is in direct contact with the contact auxiliary pattern 145 at the sidewall and undercut area where the organic light emitting layer 121 is not deposited, thereby forming an auxiliary wiring 130, The electrical connection of the contact auxiliary pattern 145 and the second electrode 122 can be made in order to reduce the resistance of the second electrode 122.

Meanwhile, the auxiliary wiring of the present invention can be placed in various positions, and the auxiliary wiring can have a second electrode and a contact part (second contact hole) at various positions in the non-light emitting part.

20 to 22 are plan views showing the arrangement relationship between sub-pixels and auxiliary wiring in the organic light emitting display device of the present invention.

FIG. 20 is a plan view showing the arrangement relationship between the auxiliary wiring 130 and the contact portion of the second electrode, that is, the second contact hole 1800b, in the sub-pixel SP according to an embodiment.

As shown in FIG. 20, a plurality of pixel areas P are disposed on the substrate 100 of the organic light emitting display device. A plurality of sub-pixels (SP) are arranged in the pixel area (P).

In detail, the pixel area P may include a first sub-pixel (SP1), a second sub-pixel (SP2), a third sub-pixel (SP3), and a fourth sub-pixel (SP4). However, in the drawing, the pixel area P includes 4 sub-pixels, but the present invention is not limited to this, and the pixel area P may include 2 or 3 sub-pixels.

Here, the first sub-pixel (SP1) may be a white (W) sub-pixel, the second sub-pixel (SP2) may be a red (R) sub-pixel, and the third sub-pixel (SP3) may be a green (G) sub-pixel. The sub-pixel and the fourth sub-pixel SP4 may be blue (B) sub-pixels, but the arrangement order of the sub-pixels shown in FIG. 20 is only an example and the arrangement order of each sub-pixel is not limited to this.

Here, the first to fourth sub-pixels SP1, SP2, SP3, and SP4 may be divided into an emitting part (EA) and a non-emitting part (NEA) by the bank 150. That is, the area opened by the bank 150 may be the light emitting area (EA), and the area where the bank 350 is disposed may be the non-light emitting area (NEA). At this time, the non-emitting area (NEA) includes an area where the auxiliary wiring 130 is disposed, and the bank 350 of the non-emitting area (NEA) is open in the second contact hole 1800b to form the auxiliary wiring 130. must be exposed from the bank 350 to enable connection between the auxiliary wiring 130 and the second electrode 122.

In addition, a second contact hole 1800b through which the auxiliary wiring 130 and the second electrode 122 are connected may be disposed under each of the first to fourth sub-pixels SP1, SP2, SP3, and SP4. . Here, the auxiliary wiring 130 may be arranged in parallel with a gate line (not shown) or may be an auxiliary wiring 130 arranged in parallel with a data line (not shown).

Meanwhile, the second electrode 122 of an organic light emitting diode may be disposed on the auxiliary wiring 130. Here, the second electrodes 122 may be arranged to contact each other outside the auxiliary wiring 130 .

In addition, the drawing shows a configuration in which auxiliary wires are disposed below the first to fourth sub-pixels (SP1, SP2, SP3, and SP4), but this embodiment is not limited to this and the auxiliary wires 130 are disposed below each sub-pixel (SP1, SP2, SP3, and SP4). It may be placed on top or on the side of the pixel. That is, in this embodiment, a configuration in which one contact portion (second contact hole 1800b) is disposed per sub-pixel is sufficient. In this way, by arranging the contact unit for each sub-pixel, it is possible to adjust the voltage difference of the organic light emitting display device on a sub-pixel (SP) basis.

FIG. 21 is a plan view showing the arrangement relationship of contact portions of a plurality of sub-pixels, the auxiliary wiring 130, and the second electrode. Another arrangement relationship between the plurality of sub-pixels and the auxiliary electrode may include the same components as the previously described embodiment. Descriptions that overlap with the previously described embodiments may be omitted. Additionally, the same components have the same reference numerals.

Referring to FIG. 20 , pixel areas P including a plurality of sub-pixels SP1, SP2, SP3, and SP4 are disposed on the substrate 100. Additionally, the contact portion CA may be disposed below the pixel area P. That is, one contact portion CA between the auxiliary wiring 130 and the second electrode 122 may be disposed per pixel area P. Here, the auxiliary wiring 130 may be arranged in parallel with a gate line (not shown) or may be an auxiliary wiring arranged in parallel with a data line (not shown).

A second electrode 122 of an organic light emitting diode may be disposed on the auxiliary wiring 130. Here, the second electrodes 122 may be arranged to contact each other outside the auxiliary wiring 130 .

Although the drawing shows a configuration in which the contact portion CA is disposed below the pixel area P, the present embodiment is not limited to this, and the contact portion CA is disposed on the top or side of the pixel area P. It could be. That is, in this embodiment, a configuration in which one contact portion (CA) is disposed per pixel area (P) is sufficient. In this way, by disposing one contact portion (CA) per pixel area (P), there is an effect of adjusting the voltage difference of the organic light emitting display device on a per-pixel area (P) basis. Each contact portion CA may be formed across multiple sub-pixels in one pixel area P.

FIG. 22 is a plan view showing another arrangement relationship of a plurality of sub-pixels, the auxiliary wiring 130, and the contact portion of the second electrode. Another arrangement relationship between a plurality of sub-pixels and auxiliary wiring may include the same components as the previously described embodiments. Descriptions that overlap with the previously described embodiments may be omitted. Additionally, the same components have the same reference numerals.

Referring to FIG. 22 , a first pixel area S1 and a second pixel area S2 including a plurality of sub-pixels SP1, SP2, SP3, and SP4 are disposed on the substrate 100. Here, the first pixel area S1 and the second pixel area S2 are arranged adjacent to each other. For example, the first pixel area S1 may be located above the second pixel area S2.

Meanwhile, the contact portion CA may be disposed in the vertical direction across the first pixel area S1 and the second pixel area S2. In detail, the contact portion CA may be disposed across one sub-pixel disposed in the first pixel area S1 and one sub-pixel in the adjacent second pixel area S2.

For example, the contact portion CA may be disposed across the second sub-pixel SP2 disposed in the first pixel area S1 and the second sub-pixel SP2 disposed in the second pixel area S2. there is. Here, the second sub-pixel SP2 may be a white (W) sub-pixel.

However, the drawing shows a configuration in which the contact portion CA is disposed between the white (W) sub-pixel of the first pixel area (S1) and the white (W) sub-pixel of the second pixel area (S2). The embodiment is not limited to this, and the contact portion CA is disposed between the red (R) sub-pixel of the first pixel area (S1) and the red (R) sub-pixel of the second pixel area (P2), or It is placed between the green (G) sub-pixel of the area (P1) and the green (G) sub-pixel of the second pixel area (P2), or between the blue (B) sub-pixel of the first pixel area (P1) and the second pixel area. It may also be placed between the blue (B) sub-pixels of (P2).

Meanwhile, the second electrode 122 of an organic light emitting diode may be disposed on the auxiliary wiring 130 in the contact portion CA. Here, the second electrodes 122 may be arranged to contact each other outside the auxiliary wiring 130 .

In addition, this embodiment discloses a configuration in which one contact portion (CA) is disposed between two pixel areas, but this is not limited, and a plurality of pixel areas may be provided with one contact portion (CA). . In this way, by having a plurality of pixel areas with one contact portion CA, there is an effect of adjusting the voltage difference of the organic light emitting display device in units of a plurality of pixel areas.

As described above, in the organic light emitting display device according to the present embodiments, the area where the overcoat layer and the auxiliary wiring electrode overlap is wider than the area where the overcoat layer and the auxiliary wiring overlap, so that the overcoat layer and the auxiliary electrode overlap area. Since the organic light emitting layer is not formed, the auxiliary wiring and the second electrode of the organic light emitting diode may be sufficiently contacted in the overcoat layer and the auxiliary wiring overlap area.

Additionally, the process can be simplified by forming the above-described overcoat layer and protective film with one mask. By facilitating contact between the auxiliary wiring and the second electrode without a partition structure, there is an effect of making the thickness of the substrate thinner.

Figure 23 is a graph measuring the luminance change from one side to the opposite side between one side and the opposite side in the organic light emitting display device of the present invention.

In addition, as shown in Figure 23, when applying the contact structure between the auxiliary wiring and the second electrode of the above-described embodiments, when moving from one side of the substrate to the opposite side, it shows uniform luminance characteristics with almost no change in luminance. That is, it can be confirmed that stable display characteristics are achieved by lowering the resistance of the second electrode when applying the organic light emitting display device of the present invention.

The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present invention.

In addition, although the description has been made focusing on the embodiments above, this is only an example and does not limit the present invention, and those skilled in the art will understand the above examples without departing from the essential characteristics of the present embodiments. You will be able to see that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented.

100: Substrate D-Tr: Driving thin film transistor
106a: source electrode 106: drain electrode
107: protective film 108: overcoat layer
109: dummy overcoat layer 1800: interlayer insulation stack
1800a: first contact hole 1800b: second contact hole
120: first electrode 121: organic light-emitting layer
122: second electrode 130: auxiliary wiring
150: bank

Claims (17)

A substrate having a display area in which sub-pixels including a light-emitting part and non-emission parts surrounding the light-emitting part are arranged in a matrix, and an outer area surrounding the display area;
A driving thin film transistor provided in each sub-pixel on the substrate;
An organic display comprising a first electrode connected to the driving thin film transistor at a first node and covering the light emitting unit, a second electrode located over the entire area of the display area, and an organic light emitting layer between the first and second electrodes. light emitting diode;
an auxiliary wiring connected to a lower part of the second electrode at a second node located in the non-emission area; and
A first contact hole and a first contact hole comprising a protective film and an overcoat layer between the driving thin film transistor and the first electrode, and exposing a portion of the driving thin film transistor and the auxiliary wiring corresponding to the first node and the second node, respectively. 2 comprising an interlayer insulating stack having a contact hole,
The protective film has an undercut shape with respect to the overcoat layer at the inner portion of the second contact hole, the edge of the upper surface of the auxiliary wiring overlaps the overcoat layer protruding toward the inner portion of the second contact hole, and the second electrode is Directly connected organic light emitting display device.
delete According to clause 1,
On the inner side of the second contact hole, the overcoat layer protrudes from the protective film toward the center of the second contact hole,
An organic light emitting display device in which the organic light emitting layer is not located on an inner portion of the protective film covered by the overcoat layer and a top edge of the auxiliary wiring in the second contact hole. According to clause 3,
In the second contact hole, the second electrode is continuously in contact with an inner portion of the protective film covered by the overcoat layer and a top edge of the auxiliary wiring. According to clause 1,
The non-emission portion excluding the second contact hole further includes a bank between layers between the organic light emitting layer and the first electrode,
The organic light emitting layer is located on a bank around the second contact hole and an exposed upper surface of the interlayer insulating stack, and is disconnected from the undercut interlayer insulating stack. According to clause 1,
The protective film has a larger first diameter among the overcoat layer and the protective film at an interface that contacts each other in the second contact hole,
The organic light emitting layer is located only on the top surface of the auxiliary wiring within the second diameter of the overcoat layer. According to clause 6,
The second electrode extends the organic light emitting layer on the upper surface of the auxiliary wiring to cover the first diameter of the second contact hole, passing through the inner portion of the overcoat layer and the protective film where the organic light emitting layer is cut off, in the second contact hole. An organic light emitting display device that covers and directly contacts the top surface of auxiliary wiring around the organic light emitting layer. According to clause 1,
The organic light emitting display device further includes a transparent electrode film between the protective film and the overcoat layer, wherein the transparent electrode film protrudes more toward the inside of the second contact hole than the overcoat layer. According to clause 8,
The second electrode is in contact with the transparent electrode film on the inner side of the second contact hole,
The organic light emitting display device wherein the second electrode is in contact with a sidewall of the protective film and the auxiliary wiring is in direct contact with the auxiliary wiring covered by the overcoat layer. According to clause 8,
wherein the first electrode is a reflective metal,
The second electrode and the transparent electrode film are made of the same transparent electrode. According to clause 1,
The organic light emitting display device wherein the auxiliary wiring is located on the same layer as an electrode forming the driving thin film transistor. According to clause 5,
The overcoat layer includes a first layer that overlaps the auxiliary wiring and has a step portion in an area that does not overlap the protective film, and
On the first layer, it includes a second layer overlapping the step portion of the first layer,
The second contact hole extends from the bottom of the first layer to the top of the second layer and has an increasingly larger diameter. According to clause 12,
In the first contact hole, the first layer has a first hole exposing one electrode of the driving thin-film transistor, and is connected to the one electrode of the driving thin-film transistor through the first hole to form a contact surface on the upper part of the first layer. An organic light emitting display device including a connection electrode partially positioned to the top, and a first electrode directly connected to the connection electrode and positioned on the second layer. According to clause 13,
The organic light emitting display device wherein the bank is located only on the second layer surface inside the second contact hole. According to clause 1,
An organic light emitting display device in which the protective film is made of two layers of inorganic films with different etch rates. A substrate having a display area in which sub-pixels including a light-emitting part and non-emission parts surrounding the light-emitting part are arranged in a matrix, and an outer area surrounding the display area;
A driving thin film transistor provided in each sub-pixel on the substrate;
An organic display comprising a first electrode connected to the driving thin film transistor at a first node and covering the light emitting unit, a second electrode located over the entire area of the display area, and an organic light emitting layer between the first and second electrodes. light emitting diode;
an auxiliary wiring connected to a lower part of the second electrode at a second node located in the non-emission area;
A first contact hole and a first contact hole comprising a protective film and an overcoat layer between the driving thin film transistor and the first electrode, and exposing a portion of the driving thin film transistor and the auxiliary wiring corresponding to the first node and the second node, respectively. 2 interlayer insulation stack with contact holes; and
A contact auxiliary pattern is included between layers within the second contact hole between the auxiliary wiring and the organic light-emitting layer,
The protective film has an undercut shape with respect to the overcoat layer on the inner side of the second contact hole, the edge of the upper surface of the auxiliary wiring overlaps the overcoat layer protruding toward the inner side of the second contact hole, and the contact auxiliary pattern An organic light emitting display device connected to the second electrode with an interposer. According to clause 16,
The auxiliary contact pattern is formed on the same layer as the first electrode and directly contacts the inner side of the second contact hole and the upper surface of the auxiliary wiring,
The second electrode covers the organic light emitting layer on the top surface of the auxiliary wiring and is in direct contact with the contact auxiliary pattern at an edge of the auxiliary wiring and an inner portion of the second contact hole.