KR101604139B1 - Organic light emitting diodde desplay device and fabricating method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing method for protecting an organic light emitting diode display element from external moisture penetration and an organic light emitting diode display device by the method. An organic light emitting diode display device according to the present invention includes: an organic light emitting diode display device formed on a substrate; And a metal sealing layer for covering the top and sides of the organic light emitting diode display element in close contact with each other. According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting diode display device, including: forming an organic light emitting diode display device on a substrate; Applying a metal paste so as to cover both the top surface and the side surface of the organic light emitting diode display element; And heating the metal paste. INDUSTRIAL APPLICABILITY The organic light emitting diode display device and the method of manufacturing the same according to the present invention can completely prevent penetration of moisture and oxygen from the outside by a low cost and simple process, thereby reducing lifetime degradation and reliability of the device.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device and a method of manufacturing the same,

The present invention relates to an organic light emitting diode display and a method of manufacturing the same. In particular, the present invention relates to a sealing method for protecting an organic light emitting diode display element from external moisture penetration and an organic light emitting diode display device by the method.

2. Description of the Related Art Recently, various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes (CRTs), have been developed. Such flat panel display devices include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescence device (EL) have.

The electroluminescent device is divided into an inorganic electroluminescent device and an organic light emitting diode device depending on the material of the light emitting layer, and has a self-luminous self-luminous device, which has a high response speed and high luminous efficiency, luminance and viewing angle. The organic light emitting diode display device has an organic light emitting diode (OLED) as shown in FIG.

The OLED includes an organic electroluminescent compound layer that emits electroluminescence and a cathode electrode and an anode that face each other with the organic electroluminescent compound layer interposed therebetween, as shown in FIG. The organic electroluminescent compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer layer, EIL). The OLED emits electrons due to the energy generated from the excitons and excitons formed in the excitation process when the holes and electrons injected into the cathode and the cathode are recombined in the emission layer (EML).

The organic electroluminescent compound layer (EL) forming the OLED which is a main component of the organic light emitting diode display device is easily deteriorated by moisture or oxygen. Therefore, the organic light emitting diode display device has a sealing structure as shown in Fig. 2 is a cross-sectional view illustrating an organic light emitting diode display device having a sealing structure according to the related art.

An organic light emitting diode layer OLEDL including an EL layer is formed on a substrate SUB. The organic light emitting diode OLEDL is formed mainly in the central portion of the substrate SUB and a pad portion PAD for transmitting and receiving electric signals from an external device driving the organic light emitting diode display device is formed in the peripheral portion. The sealing glass substrate ENCAP is attached to the boundary portion with the pad portion PAD using the sealant SEAL containing the ultraviolet hardening resin material to protect the organic light emitting diode layer OLEDL from moisture and oxygen penetration from the outside do. Since moisture permeation from the outside can not be effectively prevented by using only the UV sealing material SEAL, a moisture absorptive material (GET) for absorbing moisture and oxygen permeating is attached to the central part of the sealing glass substrate ENCAP, Layer OLEDL.

Such an organic light emitting diode display device having an encapsulation structure includes a sealing glass substrate (ENCAP) and a moisture absorbing material (GET), and a sealing process using a sealing material (SEAL) is required. In addition, since the portion where the organic light emitting diode layer OLEDL is formed has an empty structure, when the large-area display device is manufactured, the sealing glass substrate ENCAP can not maintain the horizontal state, .

Therefore, a sealing method and an encapsulation structure which are expensive and which do not have high moisture and oxygen-preventing effects and can replace a conventional encapsulation structure which is not suitable for a large-area display device are desperately required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic light emitting diode display device which completely blocks moisture and oxygen penetration which adversely affect an organic electroluminescent compound layer and which has a simple sealing and sealing structure, .

According to an aspect of the present invention, there is provided an organic light emitting diode display device including: an organic light emitting diode display device formed on a substrate; And a metal sealing layer for covering the top and sides of the organic light emitting diode display element in close contact with each other.

And the metal sealing layer has a melting point of 150 캜 or less.

Wherein the metal sealing layer is made of one selected from indium and bismuth; Tin and silver are mixed with each other.

And a buffer metal layer between the organic light emitting diode display element and the metal sealing layer.

The buffer metal layer may include at least one of copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), and gold (Au).

The organic light emitting diode display device includes: a data line and a scan line defining a pixel region; A switching TFT connected to the data line and the scan line; A driving TFT connected to a drain electrode of the switching TFT; A driving current supply wiring connected to a source electrode of the driving TFT; An anode electrode connected to a drain electrode of the driving TFT; An organic layer formed on the anode electrode; And a cathode electrode formed on the organic layer.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting diode display device, including: forming an organic light emitting diode display device on a substrate; Applying a metal paste so as to cover both the top surface and the side surface of the organic light emitting diode display element; And heating the metal paste.

The heating step is characterized in that the metal paste is heated with a heat of 150 DEG C or less.

Wherein the metal paste comprises one selected from the group consisting of indium and bismuth; Tin and silver are mixed with each other.

The method further includes applying a buffer metal layer on the organic light emitting diode display element after forming the organic light emitting diode display element and before applying the metal paste.

The buffer metal layer may include at least one of copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), and gold (Au).

The organic light emitting diode display device according to the present invention can achieve an effect of completely blocking the inflow of moisture and oxygen from the outside by adhering the upper and side portions of the organic light emitting diode display device to the metal sealing layer. Since the organic light emitting diode device is sealed with the metal sealing layer by the heating process after the metal paste is applied, the process is simple and the cost is low. Therefore, the organic light emitting diode display device and the method of manufacturing the same according to the present invention can completely prevent penetration of moisture and oxygen from the outside with low cost and simple process, thereby reducing lifetime degradation and reliability of the device.

Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 3 to 5. FIG. 3 is a plan view showing an organic light emitting diode display device according to the present invention. FIG. 4 is a cross-sectional view showing an organic light emitting diode display element cut along a perforated line I-I 'in FIG. 5A to 5C are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display device according to the present invention.

3 and 4, an organic light emitting diode display device according to an embodiment of the present invention includes a data line DL and a scan line SL defining a pixel region formed on a substrate SUBP, a data line DL, A switching TFT SWTFT connected to the scan line SL, a driving TFT DRTFT connected to the switching TFT SWTFT, an organic light emitting diode OLED connected to the driving TFT DRTFT, and TFTs SWTFT and DRTFT. And a metal sealing layer (MENCAP) covering the organic light emitting diode (OLED).

Hereinafter, a method of manufacturing an organic light emitting diode display device according to an embodiment of the present invention will be described in detail with reference to FIGS. 5A to 5C.

First, an organic light emitting diode display device is formed on a substrate SUB as shown in FIG. 5A. A scan line SL formed on the substrate SUB, a gate pad GPAD formed at one end of the scan line SL, a gate electrode GSW of the switching TFT SWTFT branched from the scan line SL, Thereby forming a gate electrode GDR of the gate electrode DRTFT. A gate insulating film GI covering the gate materials SL, GPAD, GSW and GDR is applied. The semiconductor layer ACTSW of the switching TFT SWTFT and the gate electrode GDR of the driving TFT DRTFT are formed on the gate insulating film GI that overlaps with the gate electrode GSW of the switching TFT SWTFT and the gate electrode GDR of the driving TFT DRTFT, (DRTFT) semiconductor layer (ACTDR). A source electrode SSW and a drain electrode DSW of a switching TFT SWTFT and a source electrode SDR and a drain electrode DDR of a driving TFT DRTFT are formed on both sides of the semiconductor layers ACTSW and ACTDR, ). The source electrode SDR of the driving TFT DRTFT is formed to be a part of the driving current wiring VDD which advances in parallel with the data line DL. Although not shown in the figure, the drain electrode DSW of the switching TFT SWTFT is in contact with the gate electrode GDR of the driving TFT DRTFT through a contact hole formed in the gate insulating film GT. A passivation layer PASSI is formed on the entire surface of the substrate SUB on which the source-drain electrodes SSW, DSW, SDR, and DDR are formed. Then, contact holes are formed to expose a part of the gate electrode GPAD and the drain electrode DDR of the driving TFT. An anode electrode (ANO) defining a pixel is formed on the passivation layer (PASSI). The anode electrode ANO contacts the drain electrode DDR of the driving TFT through the contact hole. A gate pad electrode GPADE is also formed on the gate pad GPAD. A pixel region is defined by forming a bank pattern BANK on a protective film PASSI and an anode electrode ANO of the portion where the TFTs SWTFT and DRTFT and the respective lines DL, SL and VDD are formed. An organic layer EL and a cathode electrode CAT are formed on the exposed anode electrode ANO in the pixel region. 5A, the organic layer EL and the cathode electrode CAT are depicted as being formed only in the pixel region defined by the bank pattern BANK. However, the organic layer EL and the cathode electrode CAT may be formed by using the bank pattern BANK, It may be formed so as to cover all over the electrode ANO.

A buffer metal layer BUFF such as copper (Cu), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti) or gold (Au) is formed on the organic light emitting diode display element formed as shown in FIG. do. At this time, it is necessary that the buffer metal layer BUFF is formed so as to be applied not only to the top of the organic light emitting diode display device but also to the side surface thereof. This buffer metal layer BUFF is a metal layer for enhancing the contact property of a low-temperature metal material which is a main component of a metal sealing layer (MENCAP) to be formed later. (Fig. 5B)

A metal paste (MP) obtained by mixing paste materials such as low temperature metal powder and rosin on the buffer metal layer BUFF is applied to the entire surface of the buffer metal layer BUFF on the substrate SUB. The low-temperature metal powder constituting the metal paste (MP) preferably has a low melting point metal material having a melting point of 150 캜 in powder form. The metal powder of the metal paste (MP) may include a main metal material such as indium or bismuth and a sub-metallic material such as tin or silver. Also, the metal paste (MP) may be a mixture of a low melting point metal material and a flux material such as rosin at a ratio of about 9: 1. The metal paste (MP) is applied by using a dispensing method, a screen printing method, or a slit coating method. (Fig. 5C)

Then, a temperature of about 150 DEG C is applied to the metal paste (MP). Then, the low-melting metal constituting the metal paste (MP) is melted and separated from the paste material, and the metal sealing layer (MENCAP) is formed by bonding with the buffer metal layer (Buff) at the bottom. At this time, as a method of heating the metal paste, a hot plate method for applying heat to the entire substrate SUB, or a hot air blowing method for inducing hot air to a hot paste can be used. (Figure 4)

Here, the metal sealing layer (MENCAP) covers not only the upper surface but also the side surface of the organic light emitting diode display element in a sealed manner. However, the application area of the metal paste should be set so that the pad portion such as the gate pad electrode (GPADE) can be exposed. Although only the gate pad GPAD and the gate pad electrode GPADE are shown in the drawing, a data pad and a data pad electrode may be formed at an end of the data line DL. Thus, the pad portion here includes all the pads for constituting the organic light emitting diode display element.

In the embodiment of the present invention, the buffer metal layer BUFF is formed before the metal seal layer (MENCAP) is formed with the metal paste. However, the process of forming the buffer metal layer BUFF may be omitted. Particularly, when the cathode electrode CAT is formed on both the bank pattern BANK and the organic layer EL and when the cathode electrode CAT is formed to include the buffer metal layer BUFF material, ) May not need to be applied. For example, when the cathode electrode (CAT) is made of an alloy containing aluminum (Al), titanium (Ti), molybdenum (Mo) or chromium (Cr), and the bank pattern (BANK) In addition, when the bank pattern BANK is formed so as to cover the side surface of the bank pattern BANK, the step of applying the buffer metal layer BUFF may be omitted.

Since the metal sealing layer (MENCAP) covers almost all of the upper surface of the display element in the above-described embodiment, the organic light emitting diode display according to the present embodiment has a bottom emission (Bottom Emission) structure. The arrows in Figs. 4 to 5 indicate the emitting direction of the organic light emitting diode (OLED). Therefore, the present invention is not limited to the above-described embodiments, but is a sealing method applicable to all organic light emitting display devices having a lower light emitting structure.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1 shows an organic light emitting diode device.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light-

3 is a plan view showing an organic light emitting diode display device according to the present invention.

FIG. 4 is a cross-sectional view showing an organic light emitting diode display element cut along a perforated line I-I 'of FIG. 3;

5A to 5C are cross-sectional views illustrating a method of manufacturing an organic light emitting diode display device according to the present invention.

Description of the Related Art

HIL: Hole injection layer HTL: Hole transport layer

EML: light emitting layer ETL: electron transporting layer

EIL: electron injection layer BANK: bank pattern

OLED: organic light emitting diode layer PAD: pad portion

SUB, SUBP: Substrate SEAL: Substance

ENCAP: Glass substrate for sealing GET: Absorbent material

DL: Data line SL: and scan line

SWTFT: switching TFT DRTFT: driving TFT

OLED: organic light emitting diode VDD: drive current supply wiring

CAT: cathode electrode ANO: anode electrode

EL: organic layer

GSW, GDR: gate electrode SSW, SDR: source electrode

DSW, DDR: drain electrode ACTSW, ACTDR: semiconductor layer

GI: Gate insulating film PASSI: Protective film

GPAD: Gate Pad GPADE: Gate Pad Electrode

BANK: bank pattern BUFF: buffer metal layer

MP: Metal paste MENCAP: Metal sealing layer

Claims (15)

An organic light emitting diode display element formed on a substrate; A metal sealing layer which is in close contact with the top and sides of the organic light emitting diode display element; And And a buffer metal layer between the organic light emitting diode display element and the metal sealing layer. The method according to claim 1, Wherein the metal sealing layer has a melting point of 150 DEG C or less. The method according to claim 1, Wherein the metal sealing layer is made of one selected from indium and bismuth; Tin and silver are mixed with each other in the organic light emitting diode display device. delete The method according to claim 1, Wherein the buffer metal layer comprises at least one of copper, aluminum, molybdenum, chromium, titanium, and gold. The method according to claim 1, The organic light emitting diode display element A data line and a scan line defining a pixel region; A switching TFT connected to the data line and the scan line; A driving TFT connected to a drain electrode of the switching TFT; A driving current supply wiring connected to a source electrode of the driving TFT; An anode electrode connected to a drain electrode of the driving TFT; An organic layer formed on the anode electrode; And a cathode electrode formed on the organic layer. The method according to claim 6, The organic light emitting diode display device may further include a pad portion formed at one end of the data line and the scan line, Wherein the metal sealing layer does not cover and seal the pad portion. Forming an organic light emitting diode display element on a substrate; Applying a buffer metal layer on the organic light emitting diode display element; Applying a metal paste to cover the upper surface and side surfaces of the organic light emitting diode display element including the buffer metal layer; And heating the metal paste. 9. The method of claim 8, Wherein the heating step heats the metal paste with a heat of 150 DEG C or less. 9. The method of claim 8, Wherein the metal paste is a mixture of a metal powder and a flux material at a ratio of 9: 1. 11. The method of claim 10, Wherein the metal powder is selected from indium and bismuth; Tin and silver is mixed with a selected one of the metallic materials. delete 9. The method of claim 8, Wherein the buffer metal layer comprises at least one of copper (Cu), aluminum (Al), molybdenum (Mo), chrome (Cr), titanium (Ti), and gold (Au) Way. 9. The method of claim 8, Wherein forming the organic light emitting diode display element comprises: Forming a gate electrode on one side of the scan line, a gate electrode of a switching TFT branched in the scan line in the pixel region, and a gate electrode of a driving TFT; Forming a gate insulating film on the entire surface of the substrate including the gate electrode of the switching TFT and the gate electrode of the driving TFT; Forming a semiconductor layer of a switching TFT and a semiconductor layer of a driving TFT on a gate insulating film of the switching TFT and a gate electrode of the driving TFT; Forming a source electrode and a drain electrode of the switching TFT and a source electrode and a drain electrode of the driving TFT on the semiconductor layer of each of the switching TFTs and the semiconductor layer of the driving TFT; Forming a protective film covering a source electrode and a drain electrode of the switching TFT, and a front surface of the substrate on which a source electrode and a drain electrode of the driving TFT are formed; Forming a gate pad electrode connected to the gate pad and an anode electrode connected to a drain electrode of the driving TFT; Forming an organic layer on the anode electrode; And forming a cathode electrode on the organic layer. 15. The method of claim 14, Wherein the step of applying the metal paste comprises exposing the gate pad and applying the metal paste to cover the organic light emitting diode display element.

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