Organic light emitting diode display device and method for manufacturing the same

Abstract

To provide an organic light emitting diode display device capable of reducing or preventing a lateral leakage current.SOLUTION: An organic light emitting diode display device includes: a substrate having first and second subpixels; an interlayer insulating layer disposed atop the substrate and having a trench between the first and second subpixels; a first electrode in each of the first and second subpixels atop the interlayer insulating layer; a bank covering an edge portion of the first electrode and exposing a central portion of the first electrode; a light emitting layer and a second electrode sequentially disposed atop the bank and the first electrode exposed through the bank and divided into the first and second subpixels over the trench; and a passivation film disposed atop the second electrode and surrounding the light emitting layer and the second electrode.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly to an organic light emitting diode display device including a first and a second stack, a charge generation layer, and a passivation film surrounding the side surface of a second electrode, and a method for manufacturing the same.

Background Art

[0002] As society recently enters a full-fledged information age, interest in information displays for processing and displaying a large amount of information has been increasing. In addition, due to the high demand for using portable information media, various lightweight and thin flat panel display devices have been developed and are in the spotlight in response to this.

[0003] Among such flat panel display devices, an organic light emitting diode display device is a self-emitting type, which has advantages such as a wider viewing angle, a higher contrast ratio than a liquid crystal display device, and can be lightweight and thin because a separate backlight is not required, and has an advantage in power consumption. In addition, the organic light emitting diode display device can be driven by a DC low voltage, has a fast response speed, and has an advantage of low manufacturing cost.

[0004] Recently, a head mounted display including an organic light emitting diode display device has been developed. The head mounted display is a virtual reality (VR) or augmented reality (AR) glasses-type monitor device that is worn in the form of glasses or a helmet and forms a focus at a short distance in front of the user's eyes.

[0005] Such head-mounted displays are applied with high-resolution small-sized organic light-emitting diode display devices, and the high-resolution small-sized organic light-emitting diode display devices can be formed by using semiconductor processes on a wafer substrate. In this case, an anode is formed on an insulating film covering a thin-film transistor formed on the wafer, and there is a problem that current flows through a light-emitting layer formed on the anode and side leakage current is generated.

[0006] In addition, due to the step between the anode and the insulating film, the light-emitting layer is unevenly formed at the edge of the anode, and as a result, there is a problem that two or more of the anode, the charge generation layer, and the cathode are short-circuited to each other.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention is presented to solve such problems. By forming trenches with a relatively wide width between sub-pixels to separate the first and second stacks, the charge generation layer, and the second electrode for each sub-pixel, an organic light-emitting diode display device in which side leakage current is prevented and a manufacturing method thereof are provided.

[0008] And another object of the present invention is to provide an organic light-emitting diode display device and a manufacturing method thereof in which moisture and oxygen penetration through the step corresponding line of the sealing layer are prevented and reliability is improved by forming a passivation film surrounding the sides of the first and second stacks, the charge generation layer, and the second electrode separated for each sub-pixel.

Means for Solving the Problems

[0009] To solve the above problems, the present invention provides an organic light-emitting diode display device including: a substrate having first and second sub-pixels; an interlayer insulating layer disposed on top of the substrate and having a trench between the first and second sub-pixels; first electrodes disposed on top of the first and second sub-pixels respectively above the interlayer insulating layer; a bank covering an edge portion of the first electrode and exposing a central portion of the first electrode; a light-emitting layer and a second electrode sequentially disposed on top of the bank and on top of the first electrode exposed through the bank, and separated for the first and second sub-pixels respectively above the trench; and a passivation film disposed on top of the second electrode and surrounding the light-emitting layer and the second electrode.

[0010] And the passivation film may extend to cover upper and side surfaces of the light-emitting layer and the second electrode and be in contact with sidewalls of the trench.

[0011] Also, the light-emitting layer may include a first stack disposed on top of the first electrode, a charge generation layer disposed on top of the first stack, and a second stack disposed on top of the charge generation layer.

[0012] And an oxidized portion having insulating properties may be disposed at a portion where the charge generation layer above the trench and the second electrode are adjacent.

[0013] Also, the width of the trench may be 0.6 times or more the thickness of the light-emitting layer.

[0014] And the organic light-emitting diode display device may further include thin-film transistors disposed on the first and second sub-pixels respectively between the substrate and the interlayer insulating layer and connected to the first electrodes; and first, second, and third encapsulation layers sequentially disposed on a front surface of the substrate above the passivation film.

[0015] On the one hand, the present invention provides a method for manufacturing an organic light-emitting diode display device, including the steps of forming an interlayer insulating layer on top of a substrate; forming a trench in the interlayer insulating layer between a first and a second sub-pixel; forming a first electrode on each of the first and second sub-pixels on top of the interlayer insulating layer; forming a bank that covers the upper edge of the first electrode and exposes the central portion of the first electrode; sequentially forming a light-emitting layer and a second electrode that are separated for each of the first and second sub-pixels at the upper part of the trench of the interlayer insulating layer on top of the bank and the upper part of the first electrode exposed through the bank; and forming a passivation film that surrounds the light-emitting layer and the second electrode on top of the second electrode.

[0016] And the passivation film can be formed by atomic layer deposition.

[0017] Also, the step of forming the light-emitting layer can include forming a first stack on top of the first electrode; forming a charge generation layer on top of the first stack; and forming a second stack on top of the charge generation layer.

[0018] And the method for manufacturing the organic light-emitting diode display device can further include forming a thin-film transistor connected to the first electrode on each of the first and second sub-pixels between the substrate and the interlayer insulating layer; and sequentially forming a first, a second, and a third encapsulation layer on the front surface of the substrate on top of the passivation film.

Advantages of the Invention

[0019] The present invention can reduce or prevent side leakage current by forming trenches with a relatively wide width between sub-pixels to separate the first and second stacks, the charge generation layer, and the second electrode for each sub-pixel.

[0020] Then, the present invention has the effect of preventing the penetration of moisture and oxygen through the step-corresponding line of the sealing layer and improving the reliability by forming the first and second stacks separated by sub-pixels, a charge generation layer, and a passivation film surrounding the side surface of the second electrode.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3a

Figure 3b

Figure 3c

Figure 3d

Figure 3e

Figure 3f

Figure 4a

Figure 4b

Embodiments for Carrying Out the Invention

[0022] Hereinafter, an organic light-emitting diode display device and a method of manufacturing the same according to the present invention will be described with reference to the accompanying drawings.

[0023] FIG. 1 is a drawing illustrating an organic light emitting diode display device according to an embodiment of the present invention.

[0024] As illustrated in FIG. 1, an organic light emitting diode display device 110 according to an embodiment of the present invention includes a timing control unit 120, a data driving unit 125, a gate driving unit 130, and a display panel 135.

[0025] The timing control unit 120 generates video data, a data control signal, and a gate control signal using a number of timing signals such as a video signal, a data enable signal, a horizontal synchronization signal, a vertical synchronization signal, and a clock transmitted from an external system (not shown) such as a graphics card or a TV system. Since the vertical period (or frame period) and the horizontal period can be known by counting the data enable signal, the vertical synchronization signal and the horizontal synchronization signal can be omitted. The data enable signal has a period of 1 horizontal period (1H). Then, the timing control unit 120 transmits the generated video data and data control signal to the data driving unit 125, and transmits the generated gate control signal to the gate driving unit 130.

[0026] The data driving unit 125 generates a data signal (data voltage) using the data control signal and the video data transmitted from the timing control unit 120, and supplies the generated data signal to the data wiring DL of the display panel 135.

[0027] The gate driving unit 130 generates a gate signal (gate voltage) using the gate control signal transmitted from the timing control unit 120, and supplies the generated gate signal to the gate wiring GL of the display panel 135. Then, the gate driving unit 130 can generate a light emission signal according to the structure of each sub-pixel SPr, SPg, SPb and supply it to the display panel 135.

[0028] Here, the gate driving unit 130 may be of a gate in panel (GIP) type formed together with the gate wiring GL, data wiring DL, and pixels P on the substrate of the display panel 135 and disposed in the non-display area NDA. In other embodiments, the gate driving unit 130 may be connected to the display panel 135 in a tape automated bonding (TAB) method or a chip on film method.

[0029] The display panel 135 includes a central display area DA and a non-display area NDA adjacent to or surrounding the display area DA, and displays an image using a gate signal and a data signal. The display panel 135 includes a number of pixels P, a number of gate wirings GL, and a number of data wirings DL disposed in the display area DA for displaying an image.

[0030] Each of the number of pixels P may include red, green, and blue sub-pixels SPr, SPg, SPb. In other embodiments, each of the plurality of pixels P may include a light-emitting element of a sub-pixel other than red, green, and blue. The gate wiring GL and the data wiring DL intersect each other to define red, green, and blue sub-pixels SPr, SPg, SPb, and the red, green, and blue sub-pixels SPr, SPg, SPb are respectively connected to the gate wiring GL and the data wiring DL.

[0031] Although not shown, the red, green, and blue sub-pixels SPr, SPg, SPb may each include a number of thin film transistors such as switching thin film transistors and driving thin film transistors, a storage capacitor, and a light-emitting diode.

[0032] In other embodiments, each of the plurality of pixels P can include sub-pixels SPr, SPg, SPb, and SPw for red, green, blue, and white. The gate wiring GL and the data wiring DL intersect each other to define the sub-pixels SPr, SPg, SPb, and SPw for red, green, blue, and white, and the sub-pixels SPr, SPg, SPb, and SPw for red, green, blue, and white can be connected to the gate wiring GL and the data wiring DL, respectively. Further, the sub-pixels SPr, SPg, SPb, and SPw for red, green, blue, and white can each include a plurality of thin film transistors such as a switching thin film transistor and a driving thin film transistor, and a storage capacitor and a light emitting diode.

[0033] The cross-sectional configuration of the sub-pixels of the light emitting diode display device 110 will be described with reference to the drawings.

[0034] FIG. 2 is a cross-sectional view taken along the cutting line II-II of FIG. 1, and will be described with reference to FIG. 1 together.

[0035] As shown in FIG. 2, each of the sub-pixels SPr, SPg, and SPb for red, green, and blue of the organic light emitting diode display device 110 according to an embodiment of the present invention includes a thin film transistor TFT and a light emitting diode LED.

[0036] Specifically, a thin film transistor TFT is disposed in each of the sub-pixels SPr, SPg, and SPb for red, green, and blue on the upper portion of the substrate 140.

[0037] The substrate 140 can be made of glass, plastic, a semiconductor material, or a flexible polymer film. For example, the substrate 140 can be a wafer made of single crystal silicon. The flexible polymer film can include one of polyimide (PI), polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), polyacrylate (PAR), polysulfone (PSF), cycloolefin copolymer (COC), triacetyl cellulose (TAC), polyvinyl alcohol (PVA), and polystyrene (PS).

[0038] When the organic light emitting diode display device 110 is of a top emission type in which light is emitted from above, the substrate 140 can be made of a transparent or opaque material. When the organic light emitting diode display device 110 is of a bottom emission type or a double-sided emission type in which the light of the pixel array layer irradiates the back surface of the substrate 140 and an image is displayed, the substrate 140 can be made of a transparent material. For example, the transparent material can include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), and cycloolefin copolymer (COC).

[0039] The thin film transistor TFT can be a driving thin film transistor. Although not shown, on the upper part of the substrate 140, a switching thin film transistor, a sensing thin film transistor, and a storage capacitor connected to the driving thin film transistor, a gate wiring (GL in FIG. 1) and a data wiring (DL in FIG. 1) connected to the switching thin film transistor, a power supply wiring connected to the driving thin film transistor, and a sensing wiring and a reference wiring connected to the sensing thin film transistor can be arranged.

[0040] The driving thin film transistor can be manufactured using an oxide semiconductor, and at least one switching thin film transistor can be manufactured using an oxide semiconductor.

[0041] The oxide semiconductor can consist of metal oxides of zinc (Zn), indium (In), gallium (Ga), titanium (Ti), or a combination of metals of zinc (Zn), indium (In), gallium (Ga), tin (Sn), titanium (Ti) and their metal oxides. In particular, the oxide semiconductor can include zinc oxide (ZnO), zinc tin oxide (ZTO), zinc indium oxide (ZIO), indium oxide (InO), titanium oxide (TiO), indium gallium zinc oxide (IGZO), indium zinc tin oxide (IZTO), indium zinc oxide (IZO), indium gallium tin oxide (IGTO), indium gallium oxide (IGO).

[0042] Also, various thin film transistors can be manufactured using a polycrystalline semiconductor material.

[0043] The switching thin film transistor can be switched by the gate signal of the gate wiring GL to transmit the data signal of the data wiring DL to the driving thin film transistor.

[0044] The driving thin film transistor can be switched by the data signal transmitted through the switching thin film transistor to transmit the current by the high potential voltage of the power supply wiring to the light emitting diode LED.

[0045] The sensing thin film transistor can be switched by the sensing signal of the sensing wiring to transmit the reference voltage to the driving thin film transistor or detect the voltage of the driving thin film transistor.

[0046] The storage capacitor can serve to maintain the data signal transmitted through the switching thin film transistor for one frame.

[0047] An interlayer insulating layer 142 is disposed on top of the thin film transistor TFT, and a first electrode 144 is disposed on each of the red, green, and blue sub-pixels SPr, SPg, and SPb on top of the interlayer insulating layer 142.

[0048] For example, the interlayer insulating layer 142 can be made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), or an organic insulating material such as acrylic resin, epoxy resin, phenol resin, polyamide resin, or polyimide resin, and can be formed as a single layer or a multilayer.

[0049] The first electrode 144 is connected to the thin film transistor TFT through a contact hole in the interlayer insulating layer 142.

[0050] For example, the first electrode 144 can be made of a transparent conductive material, a semi-transparent metal material, or a metal material with a high reflectivity.

[0051] When the organic light emitting diode display device 110 is a top emission type, the first electrode 144 can be formed in a structure having a relatively high reflectivity, such as a triple layer structure of titanium, aluminum, and titanium (Ti / Al / Ti), a triple layer structure of indium-tin-oxide, aluminum, and indium-tin-oxide (ITO / Al / ITO), or a triple layer structure of indium-tin-oxide, silver alloy, and indium-tin-oxide (ITO / Ag Alloy / ITO). The silver alloy can be an alloy of silver-palladium-copper (Ag-Pd-Cu:APC).

[0052] When the organic light-emitting diode display device 110 is a bottom-emission type, the first electrode 144 can be made of a transparent conductive oxide (TCO) such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) that can transmit light, or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag), or a magnesium-silver alloy (MgAg).

[0053] Such a first electrode 144 can be an anode.

[0054] A bank 146 is disposed above the first electrode 144, and trenches T are formed in the bank 146 at the boundary between the red, green, and blue sub-pixels SPr, SPg, SPb and the interlayer insulating layer 142.

[0055] The bank 146 can be referred to as a pixel definition film or a pixel definition layer that defines the light-emitting region of each sub-pixel, and the light-emitting region can expose the first electrode 144 of each sub-pixel. The bank 146 can be composed of an opaque material (e.g., a black material) so as to prevent optical interference between adjacent sub-pixels. In this case, the bank 146 can include a light-shielding material composed of at least one of a color pigment, an organic black, a black ink, and carbon.

[0056] The bank 146 covers the edge of the first electrode 144 and has an opening that exposes the central portion of the first electrode 144. The portion where the first electrode 144 is exposed through the bank 146 is defined as the light-emitting region, and the portion excluding the light-emitting region is defined as the non-light-emitting region.

[0057] In the embodiment of FIG. 2, an example is given in which the bank 146 is formed so as to expose the trench T, but in other embodiments, the banks 146 between adjacent sub-pixels may be connected and formed so as to cover the trench T.

[0058] For example, the bank 146 can be made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), or an organic insulating material such as acrylic resin, epoxy resin, phenol resin, polyamide resin, or polyimide resin, and can be formed as a single layer or a multilayer.

[0059] The trench T has a function of separating the first and second stacks 148 and 152, the charge generation layer 150, and the second electrode 154 between adjacent sub-pixels in a subsequent process to minimize or reduce the lateral leakage current.

[0060] That is, if the trench T is not formed, the first and second stacks 148 and 152 and the charge generation layer 150 of adjacent sub-pixels may be connected to each other, resulting in the generation of a lateral leakage current. Accordingly, an unwanted sub-pixel may emit light, and the color reproducibility may decrease.

[0061] Such a decrease in color reproducibility may appear more significantly when a lateral leakage current occurs between sub-pixels that emit light of different colors than when a lateral leakage current occurs between sub-pixels that emit light of the same color.

[0062] Accordingly, in the organic light emitting diode display device 110 according to an embodiment of the present invention, the trench T may be disposed between the red, green, and blue sub-pixels SPr, SPg, and SPb that emit light of different colors in order to decrease, minimize, or reduce the lateral leakage current between the red, green, and blue sub-pixels SPr, SPg, and SPb that emit light of different colors.

[0063] On the other hand, the trench T may not be disposed between sub-pixels that emit light of the same color as each other.

[0064] For example, when the organic light-emitting diode display device 110 is of the stripe type, red, green, and blue sub-pixels SPr, SPg, and SPb are sequentially and repeatedly arranged along the horizontal direction of FIG. 1, and red, green, and blue sub-pixels SPr, SPg, and SPb of the same color are arranged along the vertical direction of FIG. 1, respectively. However, the trench T is arranged in a line form between adjacent red, green, and blue sub-pixels SPr, SPg, and SPb that emit light of different colors along the vertical direction of FIG. 1, and may not be arranged between sub-pixels that emit light of the same color along the horizontal direction of FIG. 1.

[0065] A first electrode 144 exposed through the opening of the bank 146 and a first stack 148, a charge generation layer 150, a second stack 152, and a second electrode 154 are sequentially arranged on the upper part of the bank 146. The first stack 148, the charge generation layer 150, and the second stack 152 constitute a light-emitting layer, and the first electrode 144, the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 constitute a light-emitting diode LED.

[0066] The first stack 148 can include a hole injecting layer (HIL), a hole transporting layer (HTL), an emitting material layer (EML), and an electron transporting layer (ETL). The emitting material layer of the first stack 148 can emit one of red light, green light, blue light, and yellow light.

[0067] The charge generation layer (CGL) can include a negative type (N-type) charge generation layer for supplying electrons to the first stack 148 and a positive type (P-type) charge generation layer for supplying holes to the second stack 152.

[0068] The second stack 152 can include a hole transport layer (HTL), a light-emitting material layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL). The light-emitting material layer of the second stack 152 can emit one of red light, green light, blue light, and yellow light.

[0069] The light-emitting material layer of the second stack 152 can emit light of a color different from that of the light-emitting material layer of the first stack 148. For example, the light-emitting material layer of the first stack 148 can emit blue light and the light-emitting material layer of the second stack 152 can emit yellow light, or the light-emitting material layer of the first stack 148 can emit blue light and the light-emitting material layer of the second stack 152 can emit red light and green light.

[0070] The second electrode 154 can be made of a transparent conductive material, a semi-transmissive metal material, or a highly reflective metal material.

[0071] When the organic light-emitting diode display device 110 is a top-emission type, the second electrode 154 can be made of a transparent conductive oxide (TCO) such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) that can transmit light, or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag), or a magnesium-silver alloy (MgAg).

[0072] When the organic light-emitting diode display device 110 is a bottom-emission type or a double-sided emission type, the second electrode 154 can be formed in a structure having a relatively high reflectivity, such as a triple-layer structure of titanium, aluminum, and titanium (Ti / Al / Ti), a triple-layer structure of indium-tin-oxide, aluminum, and indium-tin-oxide (ITO / Al / ITO), or a triple-layer structure of indium-tin-oxide, silver alloy, and indium-tin-oxide (ITO / Ag Alloy / ITO). The silver alloy can be a silver-palladium-copper alloy (Ag-Pd-Cu: APC).

[0073] Such a second electrode 154 can be a cathode.

[0074] The first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 are separated at the upper part of the trench T by the step of the trench T and are not in contact with each other, and are separated for each of the red, green, and blue sub-pixels SPr, SPg, SPb, but are formed with a thin thickness on the sidewalls of the trench T.

[0075] For example, the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 can extend to the sidewalls of the trench T while gradually becoming thinner as they approach the substrate 140.

[0076] That is, in the organic light-emitting diode display device 110 according to the embodiment of the present invention, the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 between two adjacent ones of the red, green, and blue sub-pixels SPr, SPg, SPb are separated from each other at the upper part of the trench T, and accordingly, the lateral leakage current between the red, green, and blue sub-pixels SPr, SPg, SPb that emit light of different colors can be reduced, or minimized or decreased.

[0077] Here, in order to separate not only the first stack 148 and the charge generation layer 150 but also the second stack 152 and the second electrode 154, the trench T must be formed with a relatively wide width, and the width of the trench T can be determined in consideration of the thicknesses of the first stack 148, the charge generation layer 150, and the second stack 152, which are the light-emitting layers.

[0078] For example, the first width w1 of the trench T can be determined to be 0.6 times or more the first thickness t1 of the first stack 148, which is a light-emitting layer, the charge generation layer 150, and the second stack 152 (w1≧0.6×t1). Also, the first width w1 of the trench T can be determined to be 0.8 times or more the first thickness t1 of the light-emitting layer including the first stack 148, the charge generation layer 150, and the second stack 152 (w1≧0.6×t1). When the first width w1 of the trench T is less than 0.6 times the first thickness t1 of the first stack 148, which is a light-emitting layer, the charge generation layer 150, and the second stack 152, the first stack 148, which is a light-emitting layer, the charge generation layer 150, the second stack 152, and the second electrode 154 of the adjacent red, green, and blue sub-pixels SPr, SPg, and SPb may be connected without being separated at the upper part of the trench T.

[0079] When the width of the trench T is relatively large, the light-emitting area decreases and the aperture ratio decreases.

[0080] For example, the first width w1 of the trench T can be about 1.0 μm or less (w1≦1.0 μm). Desirably, the first width w1 of the trench T can be 0.2 μm or more and 0.8 μm or less (0.2 μm≦w1≦0.8 μm). When the first width w1 of the trench T exceeds about 1.0 μm, the light-emitting area and the aperture ratio may decrease excessively and the luminance may decrease.

[0081] The charge generation layer 150 and the second electrode 154 may come into contact with each other while being formed on the sidewalls of the trench T. In this case, the charge generation layer 150 and the second electrode 154 may be short-circuited and no voltage may be applied to the second stack 152, and the second stack 152 may not emit light.

[0082] To prevent this, in the organic light-emitting diode display device 110 according to an embodiment of the present invention, an oxidation part 158 having insulating properties is formed in the proximity part of the charge generation layer 150 and the second electrode 154 above the trench T, and as a result, a short circuit between the charge generation layer 150 and the second electrode 154 is prevented.

[0083] A passivation film 156 is disposed on the upper portion of the second electrode 154. The passivation film 156 is formed on the upper surfaces and side surfaces of the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154, and can be disposed so as to completely surround the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 such that the upper surfaces and side surfaces of the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 are not exposed.

[0084] For example, the passivation film 156 may extend to cover the upper surfaces and side surfaces of the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 and contact the side walls of the trench T.

[0085] For this purpose, the passivation film 156 can be formed by a vapor deposition method with excellent step coverage.

[0086] For example, the passivation film 156 can be formed by an atomic layer deposition (ALD) method and can be composed of a single layer or multiple layers of inorganic insulating materials such as aluminum oxide (AlOx), silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (SiOxNy).

[0087] That is, in the organic light-emitting diode display device 110 according to an embodiment of the present invention, by surrounding the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 with the passivation film 156, penetration of external moisture and oxygen into the first and second stacks 148 and 152 can be minimized or reduced.

[0088] On the upper portion of the passivation film 156, first, second, and third encapsulation layers 160, 162, and 164 are sequentially disposed.

[0089] The first and third encapsulation layers 160 and 164 are made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and the second encapsulation layer 162 can be made of an organic insulating material such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, an unsaturated polyester resin, a polyphenylene resin, a polyphenylene sulfide resin, or benzocyclobutene.

[0090] The first, second, and third encapsulation layers 160, 162, and 164 can block external moisture and oxygen.

[0091] Here, the first encapsulation layer 160 can be formed along the shape of the step of the lower passivation film 156. However, since the passivation film 156 is separated above the trench T between the red, green, and blue sub-pixels SPr, SPg, and SPb, the first encapsulation layer 160 can have a step-corresponding line SM corresponding to the trench T.

[0092] In such a step-corresponding line SM, the moisture and oxygen barrier properties of the first encapsulation layer 160 can be weakened. As a result, external moisture and oxygen can penetrate through the step-corresponding line of the first encapsulation layer 160.

[0093] In the organic light-emitting diode display device 110 according to an embodiment of the present invention, by surrounding the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 completely with the passivation film 156, external moisture and oxygen that have penetrated through the step-corresponding line of the first encapsulation layer 160 are blocked, and the penetration of external moisture and oxygen into the first and second stacks 148 and 152 can be reduced or minimized.

[0094] Although not shown in the figure, red, green, and blue color filters corresponding to the red, green, and blue sub-pixels SPr, SPg, and SPb, respectively, can be disposed on the upper portion of the third encapsulation layer 164.

[0095] As described above, in the organic light-emitting diode display device 110 according to the embodiment of the present invention, by disposing a trench T having a relatively wide width between the red, green, and blue sub-pixels SPr, SPg, and SPb, not only the first stack 148 and the charge generation layer 150 are separated at the upper part of the trench T, but also the second stack 152 and the second electrode 154 are separated, so that the side leakage current can be reduced, minimized, or decreased.

[0096] And, by disposing a passivation film 156 surrounding the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154, the penetration of external moisture and oxygen that has penetrated through the step corresponding lines of the first, second, and third encapsulation layers 160, 162, and 164 into the first and second stacks 148 and 152 can be reduced, minimized, or decreased, and the reliability can be improved.

[0097] Also, by making the passivation film 156 surrounding the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 block external moisture and oxygen, the thickness of the first, second, and third encapsulation layers 160, 162, and 164 can be reduced, and the manufacturing cost can be saved.

[0098] In the embodiment of FIG. 2, an encapsulation part including the first, second, and third encapsulation layers 160, 162, and 164 is shown, but in other embodiments, the encapsulation part may include n encapsulation layers (n is an integer). Also, the encapsulation part can include n encapsulation layers that are alternately laminated between an inorganic encapsulation layer and an organic encapsulation layer.

[0099] In the embodiment of FIG. 2, an example is given in which the light-emitting layer has a 2-stack structure of the first stack 148, the charge generation layer 150, and the second stack 152, but in other embodiments, the light-emitting layer may have a multi-stack structure of three or more stacks and two or more charge generation layers. Also in this case, three or more stacks, two or more charge generation layers, and the second electrode can be separated by the trench, and the passivation film can be disposed so as to surround three or more stacks, two or more charge generation layers, and the second electrode.

[0100] A method for manufacturing such an organic light-emitting diode display device 110 will be described with reference to the drawings.

[0101] FIGS. 3A to 3F are diagrams for explaining a method for manufacturing an organic light-emitting diode display device according to an embodiment of the present invention, and will be described with reference to FIGS. 1 and 2.

[0102] As shown in FIG. 3A, thin film transistors TFT are formed on each of the red, green, and blue sub-pixels SPr, SPg, SPb on the upper part of the substrate 140, and an interlayer insulating layer 142 is formed on the front surface of the substrate 140 above the thin film transistors TFT.

[0103] Thereafter, contact holes for exposing the thin film transistors TFT are formed in the interlayer insulating layer 142, and first electrodes 144 are formed on each of the red, green, and blue sub-pixels SPr, SPg, SPb above the interlayer insulating layer 142.

[0104] The first electrode 144 is connected to the thin film transistor TFT through the contact hole in the interlayer insulating layer 142.

[0105] Thereafter, a bank material layer 145 is formed on the front surface of the substrate 140 above the first electrode 144.

[0106] As shown in FIG. 3B, the bank material layer 145 and the interlayer insulating layer 142 are etched to cover the edge of the first electrode 144, and a bank 146 having an opening for exposing the central portion of the first electrode 144 is formed, and trenches T are formed in the interlayer insulating layer 142 between the red, green, and blue sub-pixels SPr, SPg, SPb.

[0107] In the example of FIG. 3B, an example is given in which the trench T is formed after the first electrode 144 is formed. However, in other embodiments, the first electrode 144 may be formed after the trench T is formed in the interlayer insulating layer 142.

[0108] For example, the trench T may be formed together with the contact hole for exposing the thin film transistor TFT after the interlayer insulating layer 142 is formed.

[0109] In the embodiment of FIG. 3b, an example was given in which the trench T is formed after the bank material layer 145 is formed. However, in other embodiments, the bank material layer 145 may be formed after the trench T is formed in the interlayer insulating layer 142.

[0110] As shown in FIG. 3c, a first electrode 144 exposed through the opening of the bank 146 and a first stack 148 and a charge generation layer 150 are sequentially formed on the upper portion of the bank 146.

[0111] The first stack 148 and the charge generation layer 150 can be formed by a deposition process such as evaporation or a solution process such as inkjet or coating.

[0112] The first stack 148 and the charge generation layer 150 are separated at the upper part of the trench T by the step of the trench T and are not in contact with each other, and are separated for each of the red, green, and blue sub-pixels SPr, SPg, SPb, but are formed with a thin thickness on the side walls of the trench T. For example, the thicknesses of the first stack 148 and the charge generation layer 150 in the trench T may be smaller than the thicknesses of the first stack 148 and the charge generation layer 150 in the remaining portion excluding the trench T.

[0113] For example, the first stack 148 and the charge generation layer 150 extend to the side walls of the trench T while gradually becoming thinner as they approach the substrate 140.

[0114] As shown in FIG. 3d, a second stack 152 and a second electrode 154 are sequentially formed on the upper portion of the charge generation layer 150.

[0115] The second stack 152 can be formed by a deposition process such as evaporation or a solution process such as inkjet or coating, and the second electrode 154 can be formed by a deposition process such as evaporation.

[0116] The second stack 152 and the second electrode 154 are separated at the upper part of the trench T by the step of the trench T and are spaced apart separately for each of the red, green, and blue sub-pixels SPr, SPg, and SPb without contact, but are formed with a thin thickness on the side walls of the trench T, respectively.

[0117] For example, the second stack 152 and the second electrode 154 extend to the side walls of the trench T while gradually thinning as they approach the substrate 140.

[0118] The first electrode 144, the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 constitute a light-emitting diode LED.

[0119] The charge generation layer 150 and the second electrode 154 can form an adjacent portion 157 adjacent to each other while being formed on the side walls of the trench T. In this case, the charge generation layer 150 and the second electrode 154 may be short-circuited, and no voltage is applied to the second stack 152, and the second stack 152 may not emit light.

[0120] To prevent this, in the organic light-emitting diode display device 110 according to an embodiment of the present invention, the adjacent portion 157 of the charge generation layer 150 and the second electrode 154 at the upper part of the trench T is oxidized through a subsequent passivation film 156 forming process to be changed into an oxidized portion 158 having insulating characteristics. As a result, a short circuit between the charge generation layer 150 and the second electrode 154 is prevented.

[0121] As illustrated in FIG. 3e, a passivation film 156 is formed on the upper part of the second electrode 154.

[0122] The passivation film 156 is formed on the upper surfaces and the upper parts of the side surfaces of the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154, but may be formed so as not to completely surround the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 and to expose the upper surfaces and the side surfaces of the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154.

[0123] For this purpose, the passivation film 156 can be formed by a vapor deposition method with excellent step coverage.

[0124] For example, the passivation film 156 can be formed by an atomic layer deposition (ALD) method and can be made of an inorganic insulating material such as aluminum oxide (AlOx), silicon oxide (SiOx), or silicon nitride (SiNx).

[0125] Here, by adjusting the flow rate of oxygen (O2) gas used for depositing the passivation film 156, the proximity portion 157 between the charge generation layer 150 and the second electrode 154 can be oxidized. As a result, the proximity portion 157 between the charge generation layer 150 and the second electrode 154 is changed into an oxidized portion 158 having insulating properties, preventing a short circuit between the charge generation layer 150 and the second electrode 154.

[0126] As shown in FIG. 3f, first, second, and third encapsulation layers 160, 162, and 164 are sequentially formed on the passivation film 156.

[0127] The first and third encapsulation layers 160 and 164 are made of an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and the second encapsulation layer 162 can be made of an organic insulating material such as an acrylic resin or an epoxy resin.

[0128] The first and third encapsulation layers 160 and 164 are formed by a chemical vapor deposition (CVD) method or an atomic layer deposition (ALD) method, and the second encapsulation layer 162 can be formed by a vapor deposition, printing, slit coating, or inkjet method.

[0129] In the organic light-emitting diode display device 110 according to an embodiment of the present invention, the proximity portion 157 can be changed into the oxidized portion 158 to prevent a short circuit between the charge generation layer 150 and the second electrode 154, which will be described with reference to the drawings.

[0130] FIG. 4a is a drawing illustrating the emission spectrum of an organic light emitting diode display device according to a comparative example, and FIG. 4b is a drawing illustrating the emission spectrum of an organic light emitting diode display device according to an embodiment of the present invention. The description will be made with reference to both FIG. 2.

[0131] As shown in FIG. 4a, in an organic light emitting diode display device according to a comparative example that does not perform the step of changing the proximity portion 157 to the oxidation portion 158 after the charge generation layer 150 and the second electrode 154 are in contact to form the proximity portion 157, the charge generation layer 150 and the second electrode 154 are short-circuited and no voltage is applied to the second stack 152. Therefore, the second stack 152 does not emit light and only the first stack 148 emits light, and the emission spectrum has only the first peak p1 corresponding to the blue light emitted by the first stack 148.

[0132] As shown in FIG. 4b, in the organic light emitting diode display device 110 according to an embodiment of the present invention, after the charge generation layer 150 and the second electrode 154 are adjacent to form the proximity portion 157, the proximity portion 157 is changed to the oxidation portion 158 having insulating characteristics at the passivation film 156 formation stage. Therefore, a voltage is applied to the second stack 152 without the charge generation layer 150 and the second electrode 154 being short-circuited.

[0133] Accordingly, not only the first stack 148 but also the second stack 152 emits light, and the emission spectrum has the first peak p1 corresponding to the blue light emitted by the first stack 148 and the second and third peaks p2 and p3 corresponding to the green and red lights emitted by the second stack 152. As a result, the light emitting diodes LED of the first and second stacks 148 and 152 can emit white light.

[0134] As described above, in the organic light emitting diode display device 110 according to an embodiment of the present invention, by disposing the trench T having a relatively wide width between the red, green, and blue sub-pixels SPr, SPg, and SPb, not only the first stack 148 and the charge generation layer 150 are separated above the trench T, but also the second stack 152 and the second electrode 154 are separated, so that the side leakage current can be reduced, minimized, or decreased.

[0135] And, by disposing a passivation film 156 that completely surrounds the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154, penetration of external moisture and oxygen through the step-corresponding lines of the first, second, and third sealing layers 160, 162, 164 into the first and second stacks 148, 152 can be reduced, minimized, or decreased, and the reliability can be improved.

[0136] Also, by making the passivation film 156 that surrounds the first stack 148, the charge generation layer 150, the second stack 152, and the second electrode 154 block external moisture and oxygen, the thickness of the first, second, and third sealing layers 160, 162, 164 can be reduced, and the manufacturing cost can be saved.

[0137] And, by changing the proximity portion 157 between the charge generation layer 150 and the second electrode 154 into an oxidized portion 158 having insulating properties at the passivation film 156 formation stage, a short circuit between the charge generation layer 150 and the second electrode 154 can be prevented, and the light-emitting diodes LED of the first and second stacks 148, 152 can be made to operate normally.

[0138] In the above, the present invention has been described with reference to the preferred embodiments, but it will be understood by those skilled in the relevant technical field that the present invention can be variously modified and changed without departing from the technical idea and scope of the present invention described in the following claims.

Explanation of Reference Numerals

[0139] 110: Organic light-emitting diode display device TFT: Thin-film transistor LED: Light-emitting diode 144: First electrode 148: First stack 150: Charge generation layer 152: Second stack 154: Second electrode

Claims

1. A substrate having first and second sub-pixels; An interlayer insulating layer disposed on top of the substrate and having a trench between the first and second sub-pixels; First electrodes disposed respectively on the first and second sub-pixels above the interlayer insulating layer; A bank covering an edge portion of the first electrode and exposing a central portion of the first electrode; A light-emitting layer and a second electrode that are sequentially disposed on top of the first electrode exposed through the bank and are separated for each of the first and second sub-pixels above the trench; A passivation film disposed on top of the second electrode and completely surrounding the light-emitting layer and the second electrode, An organic light-emitting diode display device, wherein the passivation film in the first sub-pixel and the passivation film in the second sub-pixel are spaced apart from each other.

2. The organic light-emitting diode display device according to claim 1, wherein the passivation film extends to cover upper and side surfaces of the light-emitting layer and the second electrode and contacts a sidewall of the trench.

3. A substrate having first and second sub-pixels; An interlayer insulating layer disposed on top of the substrate and having a trench between the first and second sub-pixels; First electrodes disposed respectively on the first and second sub-pixels above the interlayer insulating layer; A bank covering an edge portion of the first electrode and exposing a central portion of the first electrode; A light-emitting layer and a second electrode that are sequentially disposed on top of the first electrode exposed through the bank and are separated for each of the first and second sub-pixels above the trench; A passivation film disposed on top of the second electrode and completely surrounding the light-emitting layer and the second electrode, The light-emitting layer includes a first stack disposed on top of the first electrode, a charge generation layer disposed on top of the first stack, and a second stack disposed on top of the charge generation layer; The charge generation layer extends to cover a side surface of the first stack and contacts a sidewall of the trench; The organic light-emitting diode display device, wherein the passivation film contacts upper and side surfaces of the second electrode and contacts a side surface of the charge generation layer.

4. The organic light-emitting diode display device according to claim 3, wherein the charge generation layer and the second electrode are insulated from each other in the trench.

5. An oxidized portion having insulating properties is disposed at a portion where the charge generation layer and the second electrode above the trench are adjacent. The organic light-emitting diode display device according to claim 3, wherein the oxidation part has a first oxidation part that is an oxide of the charge generation layer and a second oxidation part that is an oxide of the second electrode.

6. The organic light-emitting diode display device according to claim 3, wherein the thicknesses of each of the first stack, the charge generation layer, the second stack, and the second electrode in the trench are smaller than the thicknesses of each of the first stack, the charge generation layer, the second stack, and the second electrode in other portions excluding the trench.

7. The organic light-emitting diode display device according to claim 1, wherein the width of the trench is 0.6 times or more the thickness of the light-emitting layer.

8. The organic light-emitting diode display device according to claim 1, wherein the width of the trench is 1.0 μm or less.

9. A thin-film transistor disposed in each of the first and second sub-pixels between the substrate and the interlayer insulating layer and connected to the first electrode, The organic light-emitting diode display device according to claim 1, further comprising first, second, and third encapsulation layers sequentially disposed on the front surface of the substrate above the passivation film.

10. Forming an interlayer insulating layer on the upper portion of the substrate; Forming a trench in the interlayer insulating layer between the first and second sub-pixels; Forming a first electrode in each of the first and second sub-pixels above the interlayer insulating layer; Forming a bank that covers the upper edge of the first electrode and exposes the central portion of the first electrode; Sequentially forming a light-emitting layer and a second electrode separated for each of the first and second sub-pixels above the trench of the interlayer insulating layer on the upper portion of the first electrode exposed through the bank and the bank; Forming a passivation film that completely surrounds the light-emitting layer and the second electrode on the upper portion of the second electrode, A method for manufacturing an organic light-emitting diode display device, wherein the passivation film in the first sub-pixel and the passivation film in the second sub-pixel are spaced apart from each other.

11. The method for manufacturing an organic light-emitting diode display device according to claim 10, wherein the passivation film is formed by an atomic layer deposition method.

12. Forming an interlayer insulating layer on the upper portion of the substrate; Forming a trench in the interlayer insulating layer between the first and second sub-pixels; Forming a first electrode in each of the first and second sub-pixels above the interlayer insulating layer; Forming a bank that covers the upper edge of the first electrode and exposes the central portion of the first electrode; Sequentially forming a light-emitting layer and a second electrode, which are separated for each of the first and second sub-pixels, on the upper portion of the first electrode exposed through the bank and above the trench of the interlayer insulating layer; Forming a passivation film that completely surrounds the light-emitting layer and the second electrode on the upper portion of the second electrode, and The step of forming the light-emitting layer includes: Forming a first stack on the upper portion of the first electrode; Forming a charge generation layer on the upper portion of the first stack; Forming a second stack on the upper portion of the charge generation layer, and The charge generation layer is in contact with the sidewall of the trench while extending to cover the side surface of the first stack, The passivation film is in contact with the upper surface and the side surface of the second electrode and is in contact with the side surface of the charge generation layer. A method for manufacturing an organic light-emitting diode display device.

13. The method for manufacturing an organic light-emitting diode display device according to claim 12, wherein the charge generation layer and the second electrode are insulated from each other in the trench.

14. An insulating oxide portion is disposed at a portion where the charge generation layer and the second electrode are adjacent to each other above the trench, The method for manufacturing an organic light-emitting diode display device according to claim 12, wherein the oxide portion includes a first oxide portion that is an oxide of the charge generation layer and a second oxide portion that is an oxide of the second electrode.

15. The thicknesses of the first stack, the charge generation layer, the second stack, and the second electrode in the trench are smaller than the thicknesses of the first stack, the charge generation layer, the second stack, and the second electrode in other portions excluding the trench. The method for manufacturing an organic light-emitting diode display device according to claim 12.

16. The method for manufacturing an organic light-emitting diode display device according to claim 10, wherein the width of the trench is 0.6 times or more the thickness of the light-emitting layer.

17. The method for manufacturing an organic light-emitting diode display device according to claim 10, wherein the width of the trench is 1.0 μm or less.

18. Forming a thin-film transistor connected to the first electrode for each of the first and second sub-pixels between the substrate and the interlayer insulating layer; The method of manufacturing an organic light emitting diode display device according to claim 10, further comprising the step of sequentially forming first, second, and third sealing layers on the front surface of the substrate above the passivation film.

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