KR100822209B1 - Manufacturing Method of Organic Light Emitting Display - Google Patents

Abstract

According to an embodiment of the present invention, a gate electrode and a pixel electrode are formed on a substrate, a gate insulating layer covering the gate electrode and the pixel electrode is formed, and a source electrode and a drain are formed on the gate insulating layer. Forming an electrode and an organic semiconductor layer in contact with the source electrode and the drain electrode, respectively, forming a pixel defining layer on the gate insulating layer to cover the source electrode, the drain electrode and the organic semiconductor layer, and laser treating the pixel defining layer Forming an opening to expose the pixel electrode by etching using ablation, forming an organic emission layer on the opening, and forming an opposite electrode on the organic emission layer Provide a method.

Description

Method of manufacturing organic light emitting display apparatus

1 to 7 are cross-sectional views schematically illustrating a manufacturing process of an organic light emitting diode display according to an exemplary embodiment of the present invention.

<Brief description of symbols for the main parts of the drawings>

110: substrate 120: gate electrode

130: first metal layer 140: pixel electrode

150: gate insulating film 160: source electrode

170: drain electrode 180: organic semiconductor layer

190: second metal layer 200: pixel defining layer

210: opening 220: organic light emitting layer

230: counter electrode

 The present invention relates to a method of manufacturing an organic light emitting display device, and more particularly, to a method of manufacturing an organic light emitting display device capable of easily etching a pixel defining layer.

Among the flat panel display devices, the electroluminescent display device is a self-luminous display device, and has attracted attention as a next generation display device because of its advantages of having a wide viewing angle, excellent contrast, and fast response speed. In addition, an organic light emitting display device having a light emitting layer formed of an organic material has excellent luminance, driving voltage, and response speed characteristics and is capable of multicoloring as compared with an inorganic light emitting display device.

On the other hand, recent flat panel display devices are required to be thin and flexible.

In order to achieve such a flexible property, many attempts have been made to use a plastic substrate as a substrate of a display device, unlike a glass substrate. In this case, a low temperature process should be used without using a high temperature process. Therefore, there is a problem that it is difficult to use a conventional polysilicon thin film transistor.

In order to solve this problem, organic semiconductors have recently emerged. The organic semiconductor can be formed in a low temperature process and has the advantage of realizing a low-cost thin film transistor. However, since the organic semiconductor is easily damaged by a subsequent wet process, attention is required in the process.

The photolithography method was used to form an opening by patterning the pixel defining layer of the organic light emitting diode display. However, such a wet process tends to damage the underlying organic semiconductor layer and also damage the pixel electrode. In addition, the photolithography method has a problem in that the use cost and time increase due to many processes such as photoresist coating, exposure, development, etching, and stripping, and the defect rate also increases.

The present invention provides a method of manufacturing an organic light emitting display device which can easily etch a pixel defining layer.

The present invention provides a method of forming a gate electrode and a pixel electrode on a substrate, forming a gate insulating film covering the gate electrode and the pixel electrode, and forming a source electrode and a drain electrode on the gate insulating film, the source electrode and the drain electrode. Forming an organic semiconductor layer in contact with each other, forming a pixel defining layer on the gate insulating layer to cover the source electrode, the drain electrode, and the organic semiconductor layer, and etching the pixel defining layer using laser ablation to form the pixel electrode A method of manufacturing an organic light emitting display device includes forming an opening to expose the organic light, forming an organic emission layer on the opening, and forming an opposite electrode on the organic emission layer.

According to another aspect of the present invention, the present invention comprises the steps of forming a pixel electrode on a substrate, forming a pixel defining layer to cover the pixel electrode, and etching the pixel defining layer using laser ablation to the pixel electrode A method of manufacturing an organic light emitting display device includes forming an opening so as to be exposed, forming an organic emission layer on the opening, and forming an opposite electrode on the organic emission layer.

In the present invention, the pixel defining layer may include PMMA, PS, a polymer derivative having a phenol group, an acrylic polymer, an imide polymer, an arylether polymer, an amide polymer, a fluorine polymer, a p-xylene polymer or a vinyl alcohol polymer. It may consist of organics such as blends thereof.

In the present invention, the laser ablation may use an excimer laser.

In the present invention, the substrate may be a flexible substrate.

In the present invention, the pixel electrode may be formed of a material including indium tin oxide (ITO).

Hereinafter, with reference to the embodiments of the present invention shown in the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 to 7 are cross-sectional views schematically illustrating a manufacturing process of an AM organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the substrate 110 is made of a flexible material. The substrate 110 may be made of a flexible material, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), or polyether imide (PET). polyether imide, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), triacetyl cellulose (TAC), cellulose acetate propinonate : CAP) and the like.

The gate electrode 120, the pixel electrode 140, and the first metal layer 130 are formed on the substrate 110. In this case, a buffer layer (not shown) may be formed of an insulating material on the substrate 110, and the gate electrode 120, the pixel electrode 140, and the first metal layer 130 may be formed.

The gate electrode 120 may be a conductive metal such as MoW, Al, Cr, Al / Cr, conductive polyaniline, conductive poly pirrole, conductive polythiopene, polyethylene deoxythiophene, or polyethylene. Various conductive polymers may be used, such as dioxythiophene: PEDOT) and polystyrene sulfonic acid (PSS).

The first metal layer 130 is an electrode for forming a capacitor and may be simultaneously formed when the gate electrode 120 is formed of the same material as the gate electrode 120.

The pixel electrode 140 may be formed of a transparent electrode made of a transparent conductive material such as indium tin oxide (ITO) in the case of a bottom emission type in which an image is embodied in the direction of the substrate 110. In the case of a top emission type in which an image is implemented in the opposite direction of the substrate 110, the same material as that of the gate electrode 120 may be formed at the same time, and ITO may be formed to match the work function thereon.

Referring to FIG. 2, the gate insulating layer 150 is formed to cover the gate electrode 120, the first metal layer 130, and the pixel electrode 140. The gate insulating layer 150 is intended for insulation with the layers to be formed in a subsequent process. The gate insulating layer 150 may be formed of an inorganic insulating layer such as SiO 2, SiNx, Al 2 O 3, Ta 2 O 5, BST, PZT, or the like by using a chemical vapor deposition (CVD) method or a sputtering method. methylmethacrylate), PS (polystyrene), phenolic polymer, acrylic polymer, imide polymer such as polyimide, arylether polymer, amide polymer, fluorine polymer, p-xylene polymer, vinyl alcohol polymer, It may be composed of an organic insulating layer made of a polymer material such as parylene and a compound containing one or more thereof, and in some cases, various configurations are possible.

Referring to FIG. 3, the source electrode 160, the drain electrode 170, and the second metal layer 190 are formed on the gate insulating layer 150. The second metal layer 190 on the gate insulating layer 150 forms a capacitor together with the first metal layer 130 formed below the gate insulating layer 150.

Like the gate electrode 120, the source electrode 160 and the drain electrode 170 may be a conductive metal such as MoW, Al, Cr, Al / Cr, conductive polyaniline, conductive poly pirrole, or conductive poly. The polythiopene, polyethylene dioxythiophene (PEDOT), and polystyrene sulfonic acid (PSS) may be formed of various conductive polymers.

When forming the source electrode 160 and the drain electrode 170, the second metal layer 190 may be formed of the same material as the source and drain electrodes 170.

The organic semiconductor layer 180 is formed on the source electrode 160 and the drain electrode 170 so as to contact the source electrode 160 and the drain electrode 170. The organic semiconductor layer 180 may include pentacene, tetracene, anthracene, naphthalene, alpha-6-thiophene, perylene and its derivatives, rubrene And derivatives thereof, coronene and derivatives thereof, perylene tetracarboxylic diimide and derivatives thereof, perylene tetracarboxylic dianhydride and derivatives thereof, polyti Offen and its derivatives, polyparaphenylenevinylene and its derivatives, polyparaphenylene and its derivatives, polyfluorene and its derivatives, polythiophenevinylene and its derivatives, polythiophene-heterocyclic aromatic copolymers and their Derivatives, oligoacenes and derivatives thereof of naphthalene, oligothiophenes and derivatives thereof of alpha-5-thiophene, phthalocyanine and derivatives thereof, with or without metal, pyromellitic dianhi Dry and derivatives thereof, pyromellitic diimides and derivatives thereof, perylenetetracarboxylic acid dianhydrides and derivatives thereof and perylenetetracarboxylic diimides and derivatives thereof, naphthalene tetracarboxylic acid diimide and derivatives thereof, At least one of naphthalene tetracarboxylic acid dianhydride and derivatives thereof.

On the other hand, the above description has shown a thin film transistor having a bottom gate structure, but the present invention is not necessarily limited thereto, and may be applied to various thin film transistor stacked structures having a top gate structure.

Referring to FIG. 4, the pixel defining layer 200 is formed to cover the source electrode 160 and the drain electrode 170, the organic semiconductor layer 180, and the second metal layer 190. The pixel defining layer 200 may be formed of an organic insulating layer, which is a general universal polymer (PMMA, PS), a polymer derivative having a phenol group, an acrylic polymer, an imide polymer, an arylether polymer, an amide polymer, a fluorine polymer, p-xylene polymers, vinyl alcohol polymers and blends thereof are possible.

After the pixel defining layer 200 is formed, the opening 210 is formed to expose a portion of the pixel electrode 140. In this case, the opening 210 is etched using a laser ablation apparatus instead of the photolithography method. At this time, the laser beam is irradiated with KrF excimer laser. When the pixel defining layer 200 is etched by irradiating the laser beam, the energy of the laser beam is appropriately adjusted according to the thickness and the component of the pixel defining layer 200. A mask may be used to obtain a desired opening 210 pattern, and the intensity and direction of the laser beam may be adjusted without the mask.

The etching method of the opening 210 using the laser ablation may shorten the process than the conventional photolithography method. That is, the process of coating, exposing, developing, etching and stripping the photoresist is not required. In addition, the excimer laser used in the laser ablation apparatus has a high absorption rate for the organic material, which is the pixel defining layer 200, but a low absorption rate for ITO (indium tin oxide) used as the pixel electrode 140. Conventionally, when the pixel defining layer 200 is etched to form the opening 210, the etching is less etched, so that the residue of the pixel defining layer 200 remains on the pixel electrode 140 or the etching is excessive, so that the pixel electrode 140 is formed. Could cause damage. However, as the pixel defining layer 200 is etched using the laser beam, the pixel defining layer 200 may be etched with a wide process margin, and the pixel defining layer 200 remains on the pixel electrode 140 or the pixel electrode 140 is etched. ) Can be damaged. In addition, during the wet process according to the photolithography method, moisture may penetrate the pixel defining layer 200 and damage the organic semiconductor layer 180 below, which degrades the characteristics of the organic light emitting display device. However, the dry etching method using the laser ablation according to the present invention can prevent this problem.

Referring to FIG. 6, the organic emission layer 220 is formed in the opening 210. The organic light emitting layer 220 may be a low molecular or high molecular organic film. When the low molecular organic film is used, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), An electron transport layer (ETL), an electron injection layer (EIL), and the like may be formed by stacking a single or a composite structure. The organic materials usable may also be copper phthalocyanine (CuPc) or N. , N-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB), tris- Various applications include 8-hydroxyquinoline aluminum (Alq3) and the like. These low molecular weight organic films are formed by the vacuum deposition method.

In the case of the polymer organic film, the structure may include a hole transporting layer (HTL) and a light emitting layer (EML). In this case, PEDOT is used as the hole transporting layer, and polyvinylvinylene (PPV) and polyfluorene are used as the light emitting layer. Polymer organic materials such as (Polyfluorene) are used and can be formed by screen printing or inkjet printing.

Referring to FIG. 7, the opposite electrode 230 is formed on the organic emission layer 220. The opposite electrode 230 may be formed to cover all of the pixels and may be patterned to be partially formed. The opposite electrode 230 has a polarity opposite to that of the pixel electrode 140. In the case of the bottom emission type, the opposite electrode 230 may be formed as a reflective electrode, and thus has a low work function such as Ag, Mg, Al, Pt, Pd, Au. , Ni, Nd, Ir, Cr, Li, Ca, and compounds thereof.

In the case of the top emission type, the counter electrode 230 may be formed as a transparent electrode. In this case, the transparent electrode is deposited with a metal having a small work function, that is, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, and compounds thereof, and thereafter, ITO and IZO. The auxiliary electrode layer or the bus electrode line may be formed of a transparent conductive material such as ZnO or In 2 O 3.

In the case of the double-sided light emission type, both the pixel electrode 140 and the counter electrode 230 may be formed as a projection electrode.

Although not shown in the drawing, the counter electrode 230 is formed and then sealed at an upper portion thereof to be blocked from outside air.

In the method of manufacturing the OLED display according to the present invention, the pixel defining layer can be easily etched.

Although described with reference to the embodiment shown in the drawings it is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (7)

Forming a gate electrode and a pixel electrode on the substrate; Forming a gate insulating film covering the gate electrode and the pixel electrode; Forming a source electrode and a drain electrode on the gate insulating layer, and an organic semiconductor layer in contact with the source electrode and the drain electrode, respectively; Forming a pixel defining layer on the gate insulating layer to cover the source electrode, the drain electrode, and the organic semiconductor layer; Etching the pixel defining layer using laser ablation to form an opening to expose the pixel electrode; Forming an organic emission layer on the opening; Forming a counter electrode on the organic light emitting layer. delete According to claim 1, The pixel defining layer is formed of an organic material. According to claim 1, The laser ablation uses an excimer laser. The method of claim 3, wherein The organic material is formed of a polymer derivative having PMMA, PS, or a phenol group, an acrylic polymer, an imide polymer, an arylether polymer, an amide polymer, a fluorine polymer, a p-xylene polymer, a vinyl alcohol polymer, or a blend thereof. A method of manufacturing an organic light emitting display device. According to claim 1, And the substrate is a flexible substrate. According to claim 1, The pixel electrode is formed of a material containing indium tin oxide (ITO).

Images