Organic light-emitting display apparatus having an embossed structure

Provided is an organic light-emitting display apparatus including a thin-film transistor (TFT) that includes an active layer, a gate electrode, and source/drain electrodes; an organic light-emitting device that includes a pixel electrode which is connected to the TFT, an intermediate layer which includes a light-emitting layer, and an opposite electrode; and an opposite electrode contact unit in which the opposite electrode is electrically connected to a power wiring, wherein, with regard to the power wiring, a surface that contacts the opposite electrode is formed to have an embossed structure.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2013-0061255, filed on May 29, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more aspects of the present embodiments relate to an organic light-emitting display apparatus, and more particularly, to an organic light-emitting display apparatus in which a structure of an area, in which an opposite electrode that faces a pixel electrode contacts a power wiring, is improved.

2. Description of the Related Technology

Generally, an organic light-emitting display apparatus includes a thin-film transistor (TFT) and an organic light-emitting device. The organic light-emitting display apparatus has a structure in which the organic light-emitting device receives an appropriate driving signal from the TFT and emits light, thus displaying a desired image.

The TFT has a structure in which an active layer, a gate electrode, and source/drain electrodes are stacked on a substrate. Accordingly, when a current is supplied to the gate electrode via a wiring that is formed on the substrate, a current flows through the source/drain electrodes via the active layer. At the same time, a current flows through a pixel electrode of the organic light-emitting device that is connected to the source/drain electrodes.

Additionally, the organic light-emitting device includes the pixel electrode, the opposite electrode that faces the pixel electrode, and a light-emitting layer that is interposed therebetween. In such a structure, if a current flows through the pixel electrode via the TFT as described above, a proper voltage is formed between the opposite electrode and the pixel electrode. Accordingly, light is emitted from the light-emitting layer, and thus an image is displayed.

In order to form a proper voltage in the light-emitting layer as described above, the opposite electrode needs to be connected to the power wiring so as to maintain a constant voltage. In this case, an opposite electrode contact unit, which is connected to the power wiring, may generate heat.

That is, the power wiring, which is generally connected to the opposite electrode, has a structure in which a plurality of wiring layers are stacked and one wiring layer, from among the plurality of wiring layers, is connected to the opposite electrode. The plurality of wiring layers may be formed by stacking a gate electrode or a source electrode of the TFT, which are included in a display unit of the organic light-emitting display apparatus. In a process of depositing an organic light-emitting material on a pixel area in the display unit of the organic light-emitting display apparatus, an organic light-emitting material is deposited on a substrate that is separate from a deposition source for a certain distance. Thus, the organic light-emitting material may be unwantedly mixed into an opposite electrode contact unit, which is a non-display area of the organic light-emitting display apparatus. In this case, the organic light-emitting material, which is deposited on the plurality of power wirings, may cause heat generation, and thus, resultantly cause a defect of a product.

Accordingly, in order to implement a more stable organic light-emitting display apparatus, an improved structure, in which deposition of an organic light-emitting material on the opposite electrode contact unit is prevented, is demanded.

SUMMARY

One or more aspects of the present embodiments provide an organic light-emitting display apparatus in which one surface of a power wiring is formed to have an embossed structure, so that, even when an organic material is mixed in an opposite electrode contact unit, an area in which the organic material is deposited on the power wiring is minimized.

According to an aspect of the present embodiments, there is provided an organic light-emitting display apparatus including: a thin-film transistor (TFT) that includes an active layer, a gate electrode, a source electrode and a drain electrode; an organic light-emitting device that includes a pixel electrode which is connected to the TFT, an intermediate layer which includes a light-emitting layer, and an opposite electrode; and an opposite electrode contact unit in which the opposite electrode is electrically connected to a power wiring, wherein, with regard to the power wiring, a surface that contacts the opposite electrode is formed to have an embossed structure.

The power wiring may include at least one or more wiring layers, and the at least one or more wiring layers may include a wiring layer that comprises the same material and on the same layer as the source/drain electrodes of the TFT.

The power wiring may include at least one or more wiring layers, and the at least one or more wiring layers may include a wiring layer that comprises a same material and on a same layer as the gate electrode of the TFT.

The one slope of the embossed structure may forms a specific angle with regard to a deposition source that deposits an intermediate layer of the organic light-emitting device.

The specific angle may be determined so that a deposition material, which is generated from the deposition source, reaches the one slope of the embossed structure in a vertical direction.

The one slope of the embossed structure may be formed to be vertical to the substrate of the organic light-emitting display apparatus.

The embossed structure may be formed in an engraving or embossing direction with respect to the opposite electrode.

The gate electrode may include an upper gate electrode and a lower gate electrode, and the lower gate electrode may be formed on a same layer as the pixel electrode of the organic light-emitting device.

The power wiring may include first through third wiring layers, the first through third wiring layers are sequentially formed in a direction toward the opposite electrode, the first wiring layer comprises a same material and on a same layer as the lower gate electrode, the second wiring layer comprises the same material and on the same layer as the lower gate electrode, and the third wiring layer comprises the same material and on the same layer as the source electrode and the drain electrode.

The pixel electrode, the lower gate electrode, or the first wiring layer may be formed to include one or more transparent metal oxides selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium oxide (In2O3).

The upper gate electrode or the third wiring layer may include one or more materials selected from the group consisting of silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), molybdenum tungsten (MoW), and copper (Cu).

The opposite electrode contact unit may be formed in a non-display area.

The organic light-emitting display apparatus may further include an interlayer insulating layer and a pixel-defining layer that are formed outside a portion of the power wiring which is included in the opposite electrode contact unit.

The power wiring may be electrically connected to the opposite electrode via a hole that is formed on the interlayer insulating layer and the pixel-defining layer.

The interlayer insulating layer may include an inorganic insulating material, and the pixel-defining layer may include an organic insulating material.

According to another aspect of the present embodiments, there is provided method of manufacturing an organic light-emitting display apparatus, the method including forming a first conductive layer and a second conductive layer on a substrate; patterning the first conductive layer and the second conductive layer to form a pixel electrode and a first wiring layer of a power wiring from the first conductive layer, and to form a second wiring layer of the power wiring from the second conductive layer; forming an interlayer insulating layer that includes a hole exposing a part of the pixel electrode and the second wiring layer; forming a third conductive layer on the interlayer insulating layer, and patterning the third conductive layer to form a third wiring layer of the power wiring that has an embossed structure on an upper surface of the power wiring; forming a pixel-defining layer exposing a part of the pixel electrode and the third wiring layer of the power wiring; and forming an opposite electrode on the pixel-defining layer in a form of a front electrode, and which is electrically connected to the third wiring layer of the power wiring.

The method includes, after the forming of the pixel-defining layer, depositing an intermediate layer, which includes a light-emitting layer, on the pixel electrode by using a deposition source, wherein one slope of the embossed structure forms a specific angle with regard to the deposition source.

The specific angle may be determined so that a deposition material, which is generated from the deposition source, reaches the one slope of the embossed structure in a vertical direction.

The one slope of the embossed structure may be formed to be vertical to the substrate.

According to another aspect of the present embodiments, there is provided an opposite electrode contact unit, including a power wiring that includes at least one or more wiring layers; and an opposite electrode that is electrically connected to the power wiring, wherein the opposite electrode contact unit is formed in a non-display area of an organic light-emitting display apparatus, and the power wiring has an embossed structure on one surface thereof in a direction of the opposite electrode.

DETAILED DESCRIPTION

The present embodiments will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown.

FIG. 1is a schematic plan view illustrating a structure of an organic light-emitting display apparatus1according to an embodiment.

The organic light-emitting display apparatus1includes a display area110in which a plurality of pixels are arranged on a substrate10, and a non-display area120that is formed outside of the display area110.

The substrate10may be a low-temperature poly-crystalline silicon (LTPS) substrate, a glass substrate, or a plastic substrate.

In the display area110, a pixel (not shown), which forms a basic unit of a displayed image, is arranged in the form of matrix, and a wiring, which is electrically connected to each pixel, is formed. A pixel may include a pixel circuit, which includes at least one thin-film transistor (TFT) and a capacitor, and an organic light-emitting device EL. The organic light-emitting device EL has a structure in which a pixel electrode that is an anode electrode and is connected to the TFT, an organic emissive layer, and an opposite electrode that is a cathode electrode and is in the form of a front electrode are stacked. A cathode voltage is applied to each pixel via the opposite electrode.

The non-display area120may include an opposite electrode contact area130that is electrically connected to the opposite electrode (59, seeFIG. 2) in the display area110via an opposite electrode contact unit CNT, and a pad area140in which a pad PAD (not shown) via which power is applied to the display area110and the opposite electrode contact area130is formed. The opposite electrode contact area130applies a cathode voltage, which is applied from the outside via the opposite electrode contact unit CNT, to each pixel via the pad PAD. One or more opposite electrode cathode areas130and pad areas140may be formed on at least one side of the non-display area120.FIG. 1illustrates an example in which the opposite electrode cathode area130and the pad area140are respectively formed on upper and lower parts of the non-display area120. However, the present embodiments are not limited thereto. One or more opposite electrode contact units CNT may be formed in the opposite electrode cathode area130.

According to an embodiment, an upper surface of a power wiring30(seeFIGS. 4 through 6), which is included in the opposite electrode contact unit CNT, is formed to have an embossed structure. Thus, a resistance increase and heat generation, which may be caused by unintentional mixing of an organic material into the opposite electrode contact region, may be prevented.

The substrate10may be bonded to an encapsulation substrate (not illustrated), which faces the substrate100, by using a sealing member (not illustrated) that is formed on the non-display area120. Although not illustrated, the sealing member is formed on the substrate10so as to seal a light-emitting area. Thus, the light-emitting area may be protected from external air. For example, the sealing film may have a film growth structure formed by alternating a film consisting of an inorganic material such as silicon oxide or silicon nitride and a film consisting of an organic material such as epoxy or polyimide. As another example, the sealing film may include a film formed of low-melting glass such as tin oxide (SnO). However, this is only an example. The sealing film is not limited thereto, and any thin film with a sealing structure may be used as the sealing film.

FIG. 2is a schematic cross-sectional view illustrating a part of an opposite electrode contact area of a conventional organic light-emitting display apparatus.

Referring toFIG. 2, with respect to an opposite electrode contact area included in the conventional organic light-emitting display apparatus, a buffer layer11is formed on the substrate10, and a power wiring56is formed on the buffer layer11. The opposite electrode59is formed on the power wiring56. In this case, an organic material58may be unintentionally mixed between the power wiring56and the opposite electrode59. In a process of forming the organic emissive layer in a pixel area, the organic material58may be unintentionally mixed into the opposite electrode contact unit. Then, an area in which the power wiring56directly contacts the opposite electrode59may be reduced, and thus, resistance therein may be increased. A problem of mixing of the organic material58may occur when an in-line deposition method, which may be desirably used for manufacturing a large organic light-emitting diode (OLED) panel, is used. This may increase resistance in an opposite electrode contact unit, and thus, generate heat.

FIGS. 3A through 3Care schematic diagrams for explaining a method of depositing an organic material on the organic light-emitting display apparatus according to an embodiment.

FIG. 3Ais a diagram illustrating a location in which, when an organic material is deposited, a blade BLADE is formed on the substrate10. The organic material may be formed only in the display area110. Accordingly, as shown inFIG. 3A, the blade BLADE is formed in a region covering the opposite electrode contact area130and the pad area140, so that the organic material is not deposited in the opposite electrode contact area130and the pad area140, which are in the non-display area120. When a deposition material which is generated from a deposition source, that is, an organic material is formed on the substrate10, the blade BLADE functions to prevent the organic material from being formed in the non-display area120. A mask may be used, instead of the blade BLADE.

FIG. 3Bis a diagram illustrating a reason why an organic material is deposited in the opposite electrode contact area130, in spite of the use of the blade BLADE.

A deposition source SOURCE deposits a deposition material by using a tool such as a blade or a mask to distinguish a deposition area from a non-deposition area. In an example shown inFIG. 3B, an area b, which is covered by the blade BLADE, is a non-deposition area, and an area a, which is not covered by the blade BLADE, is a deposition area. It is assumed that a deposition material is sprayed from areas d1and d2of the deposition source SOURCE. Since the organic light-emitting display apparatus1is kept away from the blade BLADE by a distance Z. Accordingly, the deposition source SOURCE deposits an organic material when the deposition source SOURCE is separate from the substrate10by distances Z and TS, thus forming an intermediate layer48in the organic light-emitting device EL that will be described later. However, at the same time, the deposition source SOURCE also deposits the deposition material in the non-deposition area b, even when the blade BLADE is formed on the substrate10. This is because the blade BLADE is kept away from the organic light-emitting display apparatus1by a certain distance. In an example shown inFIG. 3B, the deposition material may be unintentionally mixed into an area expressed by the equation b=(d1*Z)/TS.

FIG. 3Cis a diagram illustrating a method of reducing an area in which a deposition material is mixed in the organic light-emitting display apparatus1, according to an embodiment.

With regard to the organic light-emitting display apparatus1according to an embodiment, an embossed structure may be formed as shown inFIG. 3C. An angle between the deposition source SOURCE and an end of the blade BLADE is θ1 in the example shown inFIG. 3B. Then, according to an embodiment, an angle between the organic light-emitting display apparatus1and one slope of the embossed structure may be θ1. In such a case, a deposition material is not deposited on the other slope of the embossed structure of the organic light-emitting display apparatus1.FIGS. 3B and 3Cschematically illustrate a case in which a deposition material is mixed in the organic light-emitting display apparatus1, accurately,FIGS. 3B and 3Cillustrate a case in which a deposition material is mixed into the power wiring30of the cathode contact unit CNT. According to an embodiment, the power wiring30is formed to have an embossed structure (to be shown inFIGS. 4 through 6). Accordingly, a problem of heat generation may be solved by increasing an area in which the power wiring30, which will be described later, directly contacts the opposite electrode19.

FIG. 4is a diagram illustrating the organic light-emitting display apparatus according to an embodiment.

Referring toFIG. 4, according to an embodiment, an upper surface of the power wiring30of the opposite electrode contact unit CNT, included in the organic light-emitting display apparatus1, is formed to have an embossed structure.

The organic light-emitting display apparatus1in the current embodiment includes the TFT, the organic-light emitting device EL, and the opposite electrode contact unit CNT in which the opposite electrode of the organic light-emitting device EL is connected to the power wiring30.

The TFT consists of an active layer21, a gate electrode20, and source/drain electrodes26sand26d. The gate electrode20consists of a lower gate electrode23and an upper gate electrode24. The lower gate electrode23comprises a transparent conductive material. The upper gate electrode24comprises metal. A gate insulating layer12is interposed between the gate electrode20and the active layer21so as to insulate the gate electrode20from the active layer21. Additionally, source/drain areas, which have an electrical conductivity, are formed at both edges of the active layer21, and are connected to the source/drain electrodes26sand26d.

The organic light-emitting device EL consists of a pixel electrode43that is electrically connected to one of the source/drain electrodes26sand26dof the TFT, the opposite electrode19that functions as a cathode, and the organic intermediate layer48that is interposed between the pixel electrode43and the opposite electrode19. A reference numeral15refers to an interlayer insulating layer (hereinafter referred to as a first insulating layer), and a reference numeral17refers to a pixel-defining layer (hereinafter referred to as a second insulating layer).

Additionally, the opposite electrode contact unit CNT includes a first wiring layer33, a second wiring layer34, and a third wiring layer36, as the power wiring30that contacts the opposite electrode19. The first wiring layer33and the second wiring layer34comprise the same material and on the same respective layers as the lower gate electrode23and the upper gate electrode24. The third wiring layer36comprises the same material and on the same layer as the source/drain electrodes26sand26d. Otherwise, according to another embodiment, a wiring layer of the power wiring30may comprise the same material and on the same layer as the gate electrode20.

Referring to the embodiment shown inFIG. 4, the first insulating layer15is formed outside the power wiring30, so as to be separate from the power wiring30with a space therebetween. The second insulating layer17is formed to fill the space between the power wiring30and the first insulating layer15, and is formed to be interposed between the third wiring layer36and the opposite electrode19. InFIG. 4, the second insulating layer17is formed to fill holes of a certain depth that are formed in) the gate insulating layer12and the buffer layer11on the substrate10. However, the second insulating layer17is not limited thereto, and may be formed to fill only an upper part of the gate insulating layer12. Additionally, according to the embodiment shown inFIG. 4, the first insulating layer15is illustrated to be separate from the power wiring30. However, a space may not be provided between the first insulating layer15and the power wiring30. Additionally, unlike the illustration inFIG. 4, the third wiring layer36may not cover ends of the first and second wiring layers33and34, and may be formed only on an upper part of the first and second wiring layers33and34.

According to an embodiment with reference toFIG. 4, since the third wiring layer36is formed to have an embossed structure, an organic material38is deposited only on one slope of the embossed structure. The organic material38may be a material that is deposited when the intermediate layer48is formed in the organic light-emitting device EL by using a deposition source. As described in detail with respect toFIG. 3C, the organic material38is deposited only on a surface that faces the deposition source SOURCE, in the embossed structure of the third wiring layer36. Accordingly, compared to the opposite electrode contact unit CNT of the conventional organic light-emitting display apparatus, an area in which the third wiring layer36directly contacts the opposite electrode19is increased, and thus, heating resistance may be reduced.

More specifically, when the embossed structure is formed as illustrated inFIG. 3C, the deposition source SOURCE deposits a deposition material with a certain incident angle. Thus, the deposition material may be formed on only one slope of the embossed structure. That is, as illustrated inFIG. 3C, when a deposition material is deposited on the substrate10with an angle of θ1 from one end of the deposition source SOURCE, if an angle between one slope of the embossed structure and the substrate10is θ1, a deposition angle and an angle of a slope at one end of the third wiring layer36are perpendicular in direction to each other. Accordingly, a deposition material is deposited only on one slope of the embossed structure of the third wiring layer36, and the deposition material may not be deposited on the other slope of the embossed structure. Therefore, an area in which the organic material38, which is the deposition material, is deposited may be minimized, and thus an amount of generated heat may be reduced.

In the embodiment shown inFIG. 4, only an upper surface of the third wiring layer36, from among the power wiring30, is illustrated to have an embossed structure. However, according to another embodiment, the organic light-emitting display apparatus1may be formed so that all wiring layers of the power wiring30may respectively have an embossed shape. For example, unlike the embodiment shown inFIG. 4, in which only the third wiring layer36has an embossed shape, the first wiring layer33, the second wiring layer34, and the third wiring layer36may be formed to have an embossed shape. That is, with regard to the organic light-emitting display apparatus1in the present embodiments, some or all layers of the power wiring30may have an embossed shape. Resultantly, an upper surface of the power wiring30in a direction towards the opposite electrode19may have an embossed shape. Accordingly, even when the organic material38is mixed into the organic light-emitting display apparatus1, the organic material38is deposited only on some slopes of the power wiring30, and thus, heating resistance may be reduced.

FIGS. 5A through 5Fare diagrams illustrating a method of manufacturing the organic light-emitting display apparatus ofFIG. 4, according to an embodiment.

Referring toFIG. 5A, the buffer layer11is formed on the substrate10so as to maintain a smoothness of the substrate10and prevent penetration of an impure element into the substrate10.

The substrate10may comprise transparent glass having silicon dioxide (SiO2) as a main component. However, the substrate10is not limited thereto, and may comprise various materials, such as transparent plastic, metal, and the like.

The active layer21of the TFT is formed on the buffer layer11. The active layer21may comprise a polycrystalline silicon material, and is patterned by using a mask process. A material of the active layer21is not limited to silicon, and the active layer21may comprise an oxide semiconductor. For example, the active layer21may comprise a galium-indium-zinc-oxide (G-I—Z—O) layer [(In2O3)a(Ga2O3)b(ZnO)c layer], where a, b, and c are real numbers, and a≧0, b≧0, and c>0. If the active layer21comprises an oxide semiconductor, a doping process, which will be explained hereinafter, may be omitted.

Then, the gate insulating layer12is formed on the patterned active layer21. The gate insulating layer12may be formed by depositing an inorganic insulating layer such as silicon nitride (SiNx) or silicon oxide (SiOx) by using a method such as plasma-enhanced chemical vapor deposition (PECVD), atmospheric pressure chemical vapor deposition (APCVD), or low pressure CVD (LPCVD).

Then, as illustrated inFIG. 5B, a first conductive layer (not illustrated) and a second conductive layer (not illustrated) are sequentially deposited on the gate insulating layer12. Then, the pixel electrode43and the auxiliary electrode44of the organic light-emitting device EL, the gate electrode20of the TFT, and the first wiring layer33and the second wiring layer34that form a part of the power wiring30, which is included in the opposite electrode contact unit CNT, are patterned.

The first conductive layer (not illustrated) is patterned into the pixel electrode43of the organic light-emitting device EL, the lower gate electrode23of the TFT, and the first wiring layer33of the power wiring30. The first conductive layer may include at least one material selected from the group consisting of transparent materials such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium oxide (In2O3).

The second conductive layer (not illustrated) is patterned into the auxiliary electrode44of the organic light-emitting device EL, the upper gate electrode24of the TFT, and the second wiring layer34of the power wiring30. The second conductive layer may include at least one material selected from silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chrome (Cr), lithium (Li), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), molybdenum tungsten (MoW), and aluminum/copper (Al/Cu).

The gate electrode20is formed at a location which corresponds to a center of the active layer21. The active layer21is doped with an n-type or p-type impurity by using the gate electrode20as a mask. Then, a channel unit is formed in an area of the active layer21that is covered by the gate electrode20, and source/drain units are formed in the other area of the active layer21that is not covered by the gate electrode20.

Then, referring toFIG. 5C, the first insulating layer15is deposited on an entire surface of the substrate10, and holes H1through H5are formed by using a mask process.

The first insulating layer15may be formed by employing a spin coating method using at least one material selected from the group consisting of organic insulating materials such as polyimide, polyamide, acryl resin, benzo-cyclo-butene (BCB), and phenolic resin. The first insulating layer15is formed to have a greater thickness than that of the gate insulating layer12, thus functioning as an interlayer insulating layer between the gate electrode20and the source/drain electrodes26sand26dof the TFT. The first insulating layer15may be formed by using an inorganic insulating material, similar to the gate insulating layer12, as well as the organic insulating material described above. The first insulating layer15may also be formed by alternating the organic insulating material and the inorganic insulating material.

The first insulating layer15is patterned to form the first hole H1exposing a partial area of the pixel electrode43of the organic light-emitting device EL, the second hole H2exposing a partial area of the auxiliary electrode44, the third and fourth holes H3and H4exposing the active layer21of the TFT, and the fifth hole H5exposing a partial or entire area of the power wiring30of the opposite electrode contact unit CNT. A periphery of the first wiring layer33and the second wiring layer34may be etched and carved to a certain depth of the gate insulating layer12and the buffer layer11, and a space may be provided between the first wiring layer33, the second wiring layer34, and the first insulating layer15. Otherwise, the present embodiments are not limited to the example shown inFIG. 5C, and the first insulating layer15may be etched so that a space is not provided between the first wiring layer33, the second wiring layer34, and the first insulating layer15.

Then, referring toFIG. 5D, a third conductive layer (not illustrated) is deposited and patterned on an entire surface of the substrate10on the first insulating layer15, thereby forming the source/drain electrodes26sand26dof the TFT and the third wiring layer36of the power wiring30. The third conductive layer may be formed by using the same material selected from among the same conductive materials used for forming the first and second conductive layers, or formed of Mo/Al/Mo. The source/drain electrodes26sand26dand the third wiring layer36are formed by patterning the third conductive layer. The third wiring layer36is formed to cover ends of the first wiring layer33and the second wiring layer34. Otherwise, the third wiring layer36may be formed on the second wiring layer34, so as not to cover ends of the second wiring layer34. Additionally, the auxiliary electrode44is etched to expose the pixel electrode43. The electrode26, which is one of the source/drain electrodes26sand26d, is connected to the auxiliary electrode44.

According to an embodiment, the third wiring layer36may be formed to have an embossed structure so that an upper part of the power wiring30has an embossed structure. In order to form the third wiring layer36to have an embossed structure, a slit mask or a half-tone mask may be used as a mask for patterning the third conductive mask.

Then, referring toFIG. 5E, the second insulating layer17is formed on the substrate10. The second insulating layer17may be formed by employing a spin coating method using at least one material selected from the group consisting of organic insulating materials such as polyimide, polyamide, acryl resin, BCB, and phenolic resin.

By patterning the second insulating layer17, holes H6and H7respectively exposing a center unit of the pixel electrode43and the third wiring layer36are formed.

Then, as illustrated inFIG. 5F, the intermediate layer48, which includes an emissive layer (EML), is formed in the hole H5that exposes the pixel electrode43. As described with regard toFIG. 3, in a process of forming the intermediate layer48, the organic material38may be also deposited in the opposite electrode contact unit CNT.

The intermediate layer48may be formed by stacking one or more layers from among functional layers such as the EML, a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), and an electron injection layer (EIL) to form a structure of a single or multiple layers.

The EML may include a low-molecular weight organic material or a polymer organic material. When the EML comprises a low-molecular weight organic material, the EML may be formed by stacking the HTL and the HIL in a direction from the EML to the pixel electrode43and stacking the ETL and the EIL in a direction from the EML to the opposite electrode19. Besides, other layers may be stacked as desired. Other organic materials such as copper phthalocyanine (CuPc), N,N′-Di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), and tris-8-hydroxyquinoline aluminum (Alq3) may be used.

In the case of the polymer EML that comprises a polymer organic material, the polymer EML includes only the HTL in addition to the EML. The HTL may be formed on the pixel electrode43by employing an ink-jet printing method or a spin-coating method using poly-(2,4)-ethylene-dihydroxy thiophene (PEDOT) or polyaniline (PAN™). The polymer EML may be formed by using polyphenylene vinylene (PPV), cyano-PPV, or polyfluorene.

In the embodiment described above, the intermediate layer48is formed in the hole H6, and an additional fluorescent material is formed for each pixel. However, the present embodiments are not limited thereto. The intermediate layer48may be formed on the entire second insulating layer17inside the display area110, regardless of a location of the pixel. The EML may be formed, for example, by vertically stacking or mixing layers that include light-emitting materials which respectively emit red, green, and blue light. If white light can be emitted, other colors can be combined. Additionally, a color conversion layer that converts the emitted white light into a predetermined color, or a color filter may be further included.

Then, the opposite electrode19is formed entirely on the substrate10. When the organic light-emitting display apparatus1is a bottom-emission type display apparatus which displays an image in a direction towards the substrate10, the pixel electrode43may be a transparent electrode, and the opposite electrode19may be a reflective electrode. The reflective electrode may be formed by thinly depositing metal having a low work function, for example, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca, LiF/Al, or a combination thereof.

Conversely, when the organic light-emitting display apparatus1is a top-emission type display apparatus which emits light in an opposite direction to the substrate, the pixel electrode43is a light reflective electrode and the opposite electrode is a light transmissive electrode. In this case, the pixel electrode43may further include a reflective layer formed of Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, ytterbium (Yb) or Ca. Then, the opposite electrode may be formed to include a transparent metal oxide such as ITO, IZO, ZnO, or In2O3so as to allow light transmission. The opposite electrode may also comprise a thin film by using metal such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, or Ca.

The opposite electrode19is deposited on an entire surface of the substrate10, and connected to the third wiring layer36of the power wiring30via the hole H7. According to an embodiment, an upper part of the power wiring30has an embossed structure. Accordingly, even when the organic material36is unintentionally mixed, the organic material38may be formed only on a partial slope of the third wiring layer36. Thus, an area in which the power wiring30and the opposite electrode19contact each other may be increased. Additionally, since the area in which the power wiring30and the opposite electrode19contact each other is increased, an area of the opposite electrode contact area130and the non-display area120may be reduced.

Additionally, according to other embodiments, a shape of an embossed structure of the power wiring30may be variously formed.

FIG. 6is a diagram illustrating the organic light-emitting display apparatus1according to another embodiment.

Referring toFIG. 6, unlike the embodiment shown inFIG. 4, one slope of the power wiring30is vertical to the substrate10. In this case, the organic material38is deposited only on the slope that is vertical to the substrate10. Thus, an area in which the opposite electrode19and the power wiring30contact each other may be increased.

FIG. 7is a diagram illustrating the organic light-emitting display apparatus1according to another embodiment.

Referring toFIG. 7, unlike the embodiment shown inFIG. 4, an upper part of the power wiring30is formed to have an embossed structure in the engraved form.

According to the present embodiments, an area in which a power wiring and an opposite electrode contact each other is increased, and thus, ignition or deterioration, which may be caused by heat generation, may be prevented.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural. Furthermore, recitation of ranges of values herein are merely intended to function as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. Finally, the steps of all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or language (e.g., “such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the embodiments unless otherwise claimed. Additionally, it is to be appreciated that all changes, equivalents, and substitutes that do not depart from the spirit and technical scope of the present embodiments are encompassed in the present embodiments according to design conditions and factors.

The present embodiments have been described more fully with reference to the accompanying drawings, in which example embodiments are shown. The embodiments may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments as defined by the appended claims.

Therefore, the scope of the embodiments is defined not by the detailed description of the embodiments but by the appended claims, and all differences within the scope will be construed as being included in the present embodiments.