KR20110072131A - Organic electro-luminescent device - Google Patents

Abstract

PURPOSE: An organic electroluminescent device is provided to prevent the penetration of contaminant by forming a seal layer between a first substrate and a second substrate and sealing a first substrate and a second substrate through a metal seal pattern. CONSTITUTION: A display region and a non-display area to surround the display region are defined in a first substrate and a second substrate. The display region includes a plurality of pixel regions. A driving thin film transistor and an organic electroluminescent diode are formed between the first substrate and the second substrate. A seal layer(120) is interposed between the first and second substrates. A first metal pattern and a second metal pattern are formed along the non-display region. A metal seal pattern(200) is formed between the first and second metal patterns.

Description

Organic electroluminescent device

The present invention relates to organic electroluminescent devices, and more particularly to encapsulation of organic electroluminescent devices.

Until recently, cathode ray tubes (CRT) have been mainly used as display devices. However, in recent years, flat panel such as plasma display panel (PDP), liquid crystal display device (LCD), organic electro-luminescent device (OLED), which can replace CRT, Display devices are widely researched and used.

Among the flat panel display devices as described above, the organic light emitting display device (hereinafter referred to as OLED) is a self-light emitting device, and since the backlight used in the liquid crystal display device which is a non-light emitting device is not necessary, a light weight can be achieved.

In addition, the viewing angle and contrast ratio are superior to the liquid crystal display device, and it is advantageous in terms of power consumption. It is also possible to drive DC low voltage, has a fast response speed, and the internal components are solid, so it is strong against external shock and has a wide temperature range. It has advantages.

In particular, since the manufacturing process is simple, there is an advantage that can reduce the production cost more than the conventional liquid crystal display device.

OLEDs having these characteristics are largely divided into a passive matrix type and an active matrix type. The passive matrix type constitutes a device in a matrix form while crossing a signal line, whereas an active matrix type is a pixel. A thin film transistor, which is a switching element that turns on / off, is positioned for each pixel.

Passive matrix type has many limitations such as resolution, power consumption, and lifespan. Recently, active matrix type OLED that can realize high resolution and large screen has been actively researched.

1 is a cross-sectional view schematically showing a cross section of a general active matrix OLED.

As shown, the OLED 10 is composed of a first substrate 1 and a second substrate 2 facing the first substrate 1, and the first and second substrates 1, 2 are connected to each other. It is spaced apart and the edge thereof is encapsulated through a seal pattern 20 and bonded.

In detail, the driving thin film transistor DTr is formed in each pixel area on the first substrate 1, and the first electrode 11 and the first electrode connected to each driving thin film transistor DTr are formed. An organic light emitting layer 13 emitting light of a specific color on the upper part of (11), and a second electrode 15 is formed on the organic light emitting layer 13.

The organic light emitting layer 13 expresses colors of red, green, and blue. In a general method, a separate organic material emitting red, green, and blue light is used for each pixel.

The first and second electrodes 11 and 15 and the organic light emitting layer 13 formed therebetween form an organic light emitting diode (E). In this case, the OLED 10 having such a structure configures the first electrode 11 as an anode and the second electrode 15 as a cathode.

On the other hand, the seal pattern 20 of the OLED 10 is typically made of a sealant made of an organic or polymer material, such a sealant is enough to allow the water molecules to move sufficiently between the molecules due to the nature of the molecular structure of the sealant It becomes the size of.

Therefore, as time passes, pollutants such as external moisture or gas penetrate the seal pattern 20 to penetrate into the OLED 10, and the penetrated sources exist within the sealed OLED 10. In this case, the organic electroluminescent diode (E), which is very sensitive to moisture and oxygen, is modified.

That is, the pollutants penetrated from the outside penetrate into the organic light emitting layer 13 of the organic light emitting diode E, and thus, the emission characteristics of the organic light emitting layer 13 may be degraded by the pollutant and the organic light emitting layer 13 It will shorten the life. In addition, black spots are generated when the source is covered by a contaminant.

In addition, when pressure such as pressing from the outside is applied, the first and second electrodes 11 and 15 or the driving thin film of the organic light emitting layer 13 are formed by the space formed between the first substrate 1 and the second substrate 2. Cracks are generated in the transistor DTr.

This causes problems such as dark spot defects, which in turn causes uneven brightness and image characteristics.

The present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to provide an organic light emitting device in which a pollutant cannot penetrate therein.

In addition, another object of the present invention is to provide an organic electroluminescent device resistant to external shocks.

Through this, it is a third object to improve the luminance and image characteristics by providing a uniform signal.

In order to achieve the above object, the present invention provides a display device comprising a first and second substrates defining a display area including a plurality of pixel areas and a non-display area surrounding the display area; A driving thin film transistor and an organic light emitting diode formed between the first and second substrates; A seal layer interposed between the first and second substrates; First and second metal patterns respectively formed along the non-display area; Provided is an organic light emitting display device including a metal seal pattern formed between the first and second metal patterns.

In this case, the seal layer is made of a combination of an organic binder and one selected from an epoxy resin, a phenol resin, an acrylic resin, a heat and photocurable resin, and the metal seal. The pattern is a mixture of a viscous solvent and metal particles.

In addition, the metal particles are indium (In), tin (Sn), zinc (Zn), lead (Pb), silver (Ag), gold (Au), aluminum (Al), aluminum alloy (Al alloy), copper ( Cu), molybdenum (Mo), molybdenum alloy (Mo alloy), tungsten (W), tungsten, titanium (Ti), bismuth (Bi) is made of one, the first metal pattern is used to form the driving thin film transistor. It is formed of a conductive material, or formed of a single layer or multiple layers of a separate metal material.

Here, the second metal pattern is formed of a conductive material used to form the driving thin film transistor, or formed of a conductive material used to form the organic light emitting diode, or formed of a single layer or multiple layers of a separate metal material. The driving thin film transistor and the organic light emitting diode are formed on the first substrate.

The driving thin film transistor is formed on the first substrate, and the organic light emitting diode is a dual panel type formed on the second substrate, and the driving thin film transistor and the organic light emitting diode are connected through a contact spacer. Are electrically connected to each other.

In addition, the seal layer includes an electrical filler (E-filler), the filler is one selected from carbon black particles or carbon nanotubes (carbon nanotube).

As described above, according to the present invention, by forming a seal layer between the first and the second substrate, and sealing the first and second substrate through a metal seal pattern mixed with a viscous solvent and conductive metal particles, the organic field There is an effect that can prevent degradation of the light emitting diode and extend the life of the OLED. In addition, by firmly bonding the first and second substrate to reduce the defective rate generated after the bonding, there is an effect of reducing the overall cost and material cost loss and improve the production yield.

In addition, the OLED of the present invention has the effect of preventing the occurrence of problems such as dark spot defects, through which there is an effect of preventing the problem that the unevenness of brightness or image characteristics occurred.

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

First Embodiment

2 is a schematic cross-sectional view of an OLED according to a first exemplary embodiment of the present invention, and FIG. 3 is an enlarged cross-sectional view of a portion of FIG. 2.

Meanwhile, the OLED 100 is divided into a top emission type and a bottom emission type according to the transmission direction of emitted light. Hereinafter, the top emission method will be described as an example.

As illustrated, the OLED 100 according to the first embodiment of the present invention includes a first substrate 101 on which a driving thin film transistor DTr and an organic light emitting diode E are formed, and an encapsulation material for encapsulation. It consists of two substrates 102, the first and second substrates 101 and 102 are spaced apart from each other, the edge portion thereof is sealed through a metal seal pattern (200) is bonded.

Here, the semiconductor layer 201 is formed on the first substrate 101. The semiconductor layer 201 is made of silicon, and a central portion thereof forms an active region 201a forming a channel, and both sides of the active region 201a. And the source and drain regions 201b and 201c doped with a high concentration of impurities.

The gate insulating film 203 is formed on the semiconductor layer 201.

A gate electrode 205 and a gate wiring extending in one direction are formed on the gate insulating film 203 so as to correspond to the semiconductor layer 201a.

In addition, a first interlayer insulating film 207a is formed on the entire upper surface of the gate electrode 205 and the gate wiring (not shown), wherein the first interlayer insulating film 207a and the gate insulating film 203 thereunder are active regions. First and second semiconductor layer contact holes 209a and 209b exposing the source and drain regions 201b and 201c located on both sides thereof are provided.

Next, an upper portion of the first interlayer insulating layer 207a including the first and second semiconductor layer contact holes 209a and 209b is spaced apart from each other and exposed through the first and second semiconductor layer contact holes 209a and 209b. And source and drain electrodes 211 and 213 in contact with the drain regions 201b and 201c, respectively.

A second interlayer insulating film 207b is formed over the first and second interlayer insulating films 207a exposed between the source and drain electrodes 211 and 213 and the two electrodes 211 and 213. The drain contact hole 215 exposes the drain electrode 213.

At this time, the semiconductor layer 201 including the source and drain electrodes 211 and 213 and the source and drain regions 201b and 201c in contact with the electrodes 211 and 213 and the gate insulating layer formed on the semiconductor layer 201. The 203 and the gate electrode 205 form a driving thin film transistor DTr.

On the other hand, although not shown in the figure, data wirings (not shown) defining pixel regions are formed to cross the gate wirings (not shown). The switching thin film transistor (not shown) has the same structure as the driving thin film transistor DTr and is connected to the driving thin film transistor DTr.

In addition, the switching thin film transistor (not shown) and the driving thin film transistor DTr in the drawing show a top gate type in which the semiconductor layer 201 is made of a polysilicon semiconductor layer as an example. It may be formed of a bottom gate type made of amorphous silicon of impurities.

In addition, the first electrode 111 constituting the organic light emitting diode E, the organic light emitting layer 113, and the second electrode 115 are sequentially disposed in an area that substantially displays an image on the second interlayer insulating film 207b. It is formed.

The first electrode 111 is connected to the drain electrode 213 of the driving thin film transistor DTr, and the first electrode 111 is formed for each pixel region P. The first electrode formed for each pixel region P is formed. A bank 221 is positioned in the non-pixel region between the electrodes 111.

That is, the bank 221 is formed in a matrix type having a lattice structure as a whole, and the bank 221 is formed as a boundary with respect to each pixel region P, so that the first electrode 111 is separated for each pixel region. It is formed into a structure.

In this case, the first electrode 111 is formed of indium tin oxide (ITO), which is a material having a relatively high work function value to serve as an anode electrode, and the second electrode 115 is formed of a cathode ( It is made of a metal material with a relatively low work function to act as a cathode.

In addition, the light emitted from the organic light emitting layer 113 is driven by the upper emission method emitted toward the second electrode 115.

Here, the organic light emitting layer 113 may be composed of a single layer made of a light emitting material, and in order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, an electron transporting layer and an electron transporting layer It may also comprise multiple layers of electron injection layers.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to the selected color signal, the OLED 100 may be formed from holes and second electrodes 115 injected into the first electrode 111. The provided electrons are transported to the organic light emitting layer 113 to form excitons, and when these excitons transition from the excited state to the ground state, light is generated and emitted in the form of visible light.

At this time, since the emitted light passes through the transparent second electrode 115 to the outside, the OLED 100 implements an arbitrary image.

In particular, the OLED 100 according to the first embodiment of the present invention is further characterized by forming a seal layer 120 on the driving thin film transistor DTr and the organic light emitting diode E. .

In this case, the seal layer 120 may be formed of a combination of an epoxy resin, a phenol resin, an acrylic resin, a heat and photocurable resin, and an organic binder.

As a result, the seal layer 120 is formed to completely cover the organic light emitting diode E, thereby preventing or slowing water penetration into the organic light emitting diode E, thereby preventing the moisture from penetrating the organic light emitting layer ( 113) can be prevented from contact with moisture.

That is, it is possible to prevent the contamination source such as moisture or gas from the outside penetrating into the organic light emitting diode E through the seal layer 120.

In addition, the OLED 100 according to the first embodiment of the present invention, as described above, in the process of bonding the first and second substrates 101 and 102, the seal pattern 200 formed at the edge thereof It characterized by using a metal sealant (hereinafter referred to as metal seal pattern) containing a metal material.

Through this, the OLED 100 is encapsulated.

The metal seal pattern 200 is composed of a mixture of a viscous solvent and conductive metal particles, wherein the viscous solvent is an epoxy resin, a phenol resin, an acrylic resin, heat and light It may be made of a combination of a curable resin and an organic binder.

The metal particles may be low melting point metals (indium (In), tin (Sn), zinc (Zn), lead (Pb) or silver (Ag), gold (Au), and aluminum () having excellent electrical and thermal conductivity. Al), aluminum alloy (Al alloy), copper (Cu), molybdenum (Mo), molybdenum alloy (Mo alloy), tungsten (W), tungsten, titanium (Ti), bismuth (Bi) and the like, or Any metal having a melting point of 400 ° C. or lower can be used.

In addition, the first and second metal patterns 210a and 210b are formed on the first and second substrates 101 and 102 corresponding to the metal seal pattern 200, and the metal seal pattern 200 has a width of the first and second substrates 101 and 102. It is formed between the first metal pattern 210a and the second metal pattern 210b to be narrower than the width of the first and first metal patterns 210a and 210b.

The first and second metal patterns 210a and 210b are to improve the interfacial properties of the metal seal pattern 200, and improve the adhesion between the metal seal pattern 200 and the first and second substrates 101 and 102. It will play a role.

In this case, the first and second metal patterns 210a may be formed of a material used for forming a switching and driving thin film transistor (DTr), or may be formed in a single layer or multiple layers with a separate metal material.

As such, the present invention uses a metal seal pattern 200 in which a viscous solvent and conductive metal particles are mixed in the seal pattern, and the first and second metals are formed between the metal seal pattern 200 and the substrates 101 and 102. By forming the patterns 210a and 210b, it is possible to prevent contamination sources such as moisture or gas from outside from penetrating into the spaces between the first and second substrates 101 and 102.

Table 1 below is a table comparing moisture permeability of the sealant actually used in the OLED 100.

Sealant material Water vapor transmission rate (g / m ² )
at 60 ℃, 90%, 100mm Organic film or polymer material > 10 Metal > ~ 10E-4

Table (1)

As shown in Table 1, it can be seen that the sealant of the organic film or the polymer material, which has been conventionally used as a seal material, has a higher moisture permeability than the metal material.

Accordingly, the present invention suppresses the moisture permeability by using a metal series having a significantly lower moisture permeability than the organic film or the polymer material, and has a higher strength than the conventional seal pattern (20 in FIG. 1), thereby providing the first and second substrates. Sealing of (101, 102) more tightly.

Through this, it is possible to prevent the infiltration of pollutants from the outside into the space between the spaced apart of the first and second substrate (101, 102).

Therefore, the organic light emitting diode E of the first embodiment of the present invention primarily protects the pollution source from the outside by the metal seal pattern 200, and also the pollution source such as water or gas by the seal layer 120. Can defend secondarily.

Through this, the degradation of the organic light emitting diode E can be prevented and the life of the OLED 100 can be extended. In addition, by firmly bonding the first and second substrates (101, 102) to reduce the failure rate generated after the bonding to reduce the overall cost and material cost loss and improve the production yield.

In addition, in the OLED 100 according to the first embodiment of the present invention, even when a pressure such as pressing from the outside is applied, the pressing of the OLED 100 is not generated by the seal layer 120, so that the first of the organic light emitting diode E And cracks in the second electrodes 111 and 115 or the driving thin film transistor DTr may be prevented.

As a result, problems such as dark spot defects may be prevented from occurring, thereby preventing the problem of uneven brightness or image characteristics.

In addition, by using a metal having a low melting point of the metal particles mixed in the metal seal pattern 200, the metal seal pattern 200 can be cured at a low temperature when the first and second substrates 101 and 102 are bonded. In addition, the switching and driving thin film transistor (DTr) and the organic light emitting diode (E) formed between the first and second substrates 101 and 102 are preferably not affected.

FIG. 4 is a plan view schematically illustrating a metal seal pattern and a seal layer formed according to the first embodiment of the present invention.

As shown, the first substrate 101 is defined by being divided into a display area AA and a non-display area NA which surrounds the edge of the display area AA. The display area AA of the first substrate 101 is defined. Although not shown in the drawings, a driving thin film transistor (DTr in FIG. 3) and an organic light emitting diode (E in FIG. 3) are formed.

The seal layer 120 is formed on the organic light emitting diode (E in FIG. 3) of the display area AA.

In addition, a metal seal pattern 200 is formed along an edge of the non-display area NA of the first substrate 101.

The first metal pattern 210a is formed along the edge of the non-display area NA of the first substrate 102, and the metal seal pattern 200 is formed on the first metal pattern 210a. As a result, the first metal pattern 210a serves to improve the adhesive force between the metal seal pattern 200 and the first substrate 101.

5A to 5H are cross-sectional views illustrating manufacturing steps of an OLED according to a first exemplary embodiment of the present invention.

First, as illustrated in FIG. 5A, the display area AA is formed of a plurality of pixel areas P, and each pixel area P includes a switching thin film transistor (not shown) and a driving thin film transistor DTr. The first substrate 101 provided with the electroluminescent diode E is prepared.

Here, the switching thin film transistor (not shown), the driving thin film transistor DTr, and the organic light emitting diode E formed in each pixel region P will be described in detail. Each pixel region P of the first substrate 101 will be described. ) To form an amorphous silicon layer (not shown), and irradiate the laser beam or perform heat treatment to crystallize the amorphous silicon layer into a polysilicon layer (not shown).

Subsequently, a polysilicon layer (not shown) is patterned by performing a mask process to form a semiconductor layer (201 of FIG. 3) in a pure polysilicon state. In this case, before forming the amorphous silicon layer (not shown), an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) may be deposited on the entire surface of the insulating substrate 101 to form a buffer layer (not shown). .

Next, silicon oxide (SiO ₂ ) is deposited on the semiconductor layer of pure polysilicon (201 of FIG. 3) to form a gate insulating film (203 of FIG. 3).

Subsequently, one of the low resistance metal materials such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), and copper alloy is deposited on the gate insulating layer 203 of FIG. 3 to form a first metal layer (not shown). The mask process is performed to form the gate electrode 205 of FIG. 3 corresponding to the center portion of the semiconductor layer 201 of FIG. 3.

Next, using the gate electrode 205 of FIG. 3 as a blocking mask, a dopant, i.e., a trivalent element or a pentavalent element, is doped on the entire surface of the first substrate 101, so that the gate electrode of FIG. The source and drain regions (201b and 201c of FIG. 3) doped with impurities are formed in a portion located outside the 205 of FIG. 3, and the portion corresponding to the doped gate electrode (205 of FIG. 3) is formed of pure polysilicon. An active region 201a of FIG. 2B is formed.

Next, an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) is deposited on the entire surface of the first substrate 101 on which the semiconductor layer 201 of FIG. 3 is formed. 207a is formed, and a mask process is performed to simultaneously or collectively pattern the first interlayer insulating film 207a in FIG. 3 and the lower gate insulating film 203 in FIG. 3 to form the source and drain of the semiconductor layer 201 in FIG. 3. First and second semiconductor layer contact holes (209a and 209b of FIG. 3) exposing regions 201b and 201c, respectively, are formed.

Subsequently, one of the metal materials such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, chromium (Cr) and molybdenum (Mo) is deposited on the first interlayer insulating film 207a of FIG. 3. To form a second metal layer (not shown), and pattern the process by performing a mask process to form source and drain regions (201b and 201c in FIG. 3) through the first and second semiconductor layer contact holes (209a and 209b in FIG. 3). Source and drain electrodes 211 and 213 of FIG. 3 are formed.

At this time, the semiconductor layer (201 of FIG. 3), the gate insulating film (203 of FIG. 3), the gate electrode (205 of FIG. 3) and the first interlayer insulating film (207a of FIG. 211 and 213 form a driving thin film transistor DTr.

Next, an organic insulating material such as photo acryl or benzocyclobutene (BCB) is coated on the first substrate 101 on which the source and drain electrodes 211 and 213 of FIG. 3 are formed, and patterned through a mask process. As a result, a second interlayer insulating film (207b in FIG. 3) is formed.

In this case, the second interlayer insulating film 207b of FIG. 3 has a drain electrode contact hole 215 of FIG. 3 exposing the drain electrode 213 of FIG. 3.

Next, the organic light emitting diode E is configured to contact the drain electrode 213 of FIG. 3 through the drain contact hole 215 of FIG. 3 on the second interlayer insulating film 207b of FIG. 3. As an element, a first electrode 111 forming an anode is formed.

Next, the first electrode 111 is coated on the first electrode 111 by applying one of photosensitive organic insulating materials, for example, black resin, graphite powder, gravure ink, black spray, and black enamel, and patterning the same. A bank (221 of FIG. 3) is formed at the top.

The bank 221 of FIG. 3 is formed in a matrix type having a lattice structure as a whole to distinguish the pixel areas P from each other.

Next, an organic light emitting layer 113 is formed by applying or depositing an organic light emitting material on the bank 221 of FIG. 3.

Next, the organic light emitting diode E is formed by forming a second electrode 115 having a thick transparent conductive material deposited on the translucent metal film having a thin work function deposited on the organic light emitting layer 113. You are done.

Thereby, the 1st board | substrate 101 of OLED (100 of FIG. 3) is completed.

At this time, only three pixel regions P are shown in the drawing, but for the sake of convenience, only three pixel regions P are shown and substantially hundreds to thousands of pixel regions are provided.

The first metal pattern 210a is formed along the non-display area NA at the edge of the display area AA of the first substrate 101. The first metal pattern 210a is formed of aluminum (Al) or aluminum. One of an alloy (AlNd), copper (Cu), and a copper alloy is deposited and formed by performing a mask process.

At the same time, as shown in FIG. 5B, the second metal pattern 210b is formed along the edge of the non-display area NA of the second substrate 102 for encapsulation of the OLED (100 of FIG. 3). .

Like the first metal pattern 210a of FIG. 5A, the second metal pattern 210b also deposits one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), and copper alloy, and performs a mask process. To form.

Next, as shown in FIG. 5C, the metal seal pattern 200 is formed on the first metal pattern 210a along the non-display area NA.

The metal seal pattern 200 is formed by applying along the edge of the non-display area NA of the first substrate 101 through a dispensing or screen printing method.

Next, as shown in FIG. 5D, a process of attaching the seal layer 120 to the insulating substrate 300 is performed to bond the first and second substrates 101 (FIG. 5C and 102 of FIG. 5B). .

That is, the first and second substrates (101 of FIG. 5C and 102 of FIG. 5B) of the present invention are bonded to each other by a predetermined distance from each other through the seal layer 120.

Here, the seal layer 120 may be formed of a combination of an epoxy resin, a phenol resin, an acrylic resin, a thermal and photocurable resin, and an organic binder.

In addition, a protective film 120a for protecting the seal layer 120 is attached to the other surface of the seal layer 120 that is bonded to the insulating substrate 300, and the protective film 120a may be a first substrate (101 in FIG. 5C). And the insulating substrate 300 are removed in the step of bonding.

Next, as shown in FIG. 5E, after the protection film (120a of FIG. 5D) of the insulating substrate 300 is removed to expose the seal layer 120, the insulating substrate 300 faces the first substrate 101. After aligning and aligning, pressing the seal layer 120 and the second electrode 115 formed on the first substrate 101 to be in close contact with each other, and then removing the insulating substrate 300, As shown, the seal layer 120 is attached onto the first substrate 101.

Next, as shown in FIG. 5G, the second substrate 102 is pressed to be in close contact with the seal layer 120. In this case, the metal seal pattern 200 formed on the first substrate 101 is bonded to the second metal pattern 210b formed along the edge of the non-display area NA of the second substrate 102.

As a result, as shown in FIG. 5H, the first substrate 101 and the second substrate 102 are completely bonded to form the OLED 100.

Therefore, the organic light emitting diode (E) according to the first embodiment of the present invention primarily protects the pollution source from the outside by the metal seal pattern 200, and furthermore, the seal layer 120 Secondary defenses against the same pollutant.

Through this, the degradation of the organic light emitting diode E can be prevented and the life of the OLED 100 can be extended.

In addition, in the OLED 100 according to the first embodiment of the present invention, even when a pressure such as pressing from the outside is applied, the pressing of the OLED 100 is not generated by the seal layer 120, so that the first of the organic light emitting diode E And cracks in the second electrodes 111 and 115 or the driving thin film transistor DTr may be prevented.

As a result, problems such as dark spot defects may be prevented from occurring, thereby preventing the problem of uneven brightness or image characteristics.

In addition, the seal layer 120 and the metal seal pattern 200 of the present invention is applicable to a dual panel type OLED.

Second Embodiment

FIG. 6 is a cross-sectional view illustrating a portion of a dual panel type OLED according to a second embodiment of the present invention, and FIG. 7 is an enlarged cross-sectional view of a portion of FIG. 6.

In this case, in order to avoid redundant description, the same reference numerals are assigned to the same parts that play the same role as the descriptions of FIGS. 2 and 3 of the first embodiment, and only the above-described features will be described.

In addition, the dual panel type OLED 300 according to the second exemplary embodiment of the present invention also describes an upper light emitting method as an example, and for convenience of description, a region in which the driving thin film transistor DTr is formed is a driving region DA. The region where the auxiliary electrode 151 is formed is defined as the non-pixel region NA and the region where the organic light emitting diode E is formed as the light emitting region PA.

As illustrated, the dual panel type OLED 300 includes a first substrate 101 having a driving thin film transistor DTr and a second substrate 102 having an organic light emitting diode E formed therein. The second substrates 101 and 102 are spaced apart from each other, and edge portions thereof are encapsulated and bonded through a metal seal pattern 200.

Here, a driving thin film transistor DTr having a gate electrode 205, a gate insulating film 203, a semiconductor layer 201, and source and drain electrodes 211 and 213 is formed on the first substrate 101.

In this case, the semiconductor layer 201 is composed of an active layer 201a of pure amorphous silicon and an ohmic contact layer 201b of amorphous silicon including impurities, wherein the driving thin film transistor DTr is pure and impurity in the drawing. A bottom gate type made of amorphous silicon 201a and 201b is shown as an example, and may be formed as a top gate type including a polysilicon semiconductor layer.

A protective layer 207 having a drain contact hole 215 exposing the drain electrode 213 of the driving thin film transistor DTr is formed on the driving thin film transistor DTr.

Next, a connection electrode 217 contacting the drain electrode 213 through the drain contact hole 215 is formed in each pixel area P on the passivation layer 207.

Meanwhile, an auxiliary electrode 151 is formed in each of the non-pixel regions NA on the second substrate 102 facing and facing the first substrate 101, and a second including the auxiliary electrode 151. A first electrode 111 forming an anode is formed on the entire surface of the substrate 102 as one component of the organic light emitting diode E.

Here, the first electrode 111 may be made of indium tin oxide (ITO), a material having a relatively high work function value.

The non-pixel area NA on the first electrode 111 on which the auxiliary electrode 151 is formed has a predetermined thickness at a position covering a boundary between each pixel area P on the buffer layer 153 and on the buffer layer 153. The partition wall 157 which has is formed.

The partition wall 157 has a structure in which the cross-sectional area of the side closer to the first electrode 111 is smaller and further away, that is, the cross-section is inversed with respect to the inner surface of the second substrate 102. ) Is made of a structure.

In addition, a columnar contact spacer 155 is formed at one side of the buffer layer 153 on which the partition wall 157 is formed, and the contact spacer 155 has a pixel area P for supplying current to the organic light emitting diode E. ) To electrically connect the driving thin film transistor DTr formed on the first substrate 101 and the organic light emitting diode E formed on the second substrate 102 to each other.

The contact spacer 155 has a tapered structure in which the cross-sectional area of the contact spacer 155 decreases as the cross-sectional area closer to the first electrode 111 becomes larger and further away.

The organic light emitting layer 113 and the second electrode 115 are sequentially formed on the entire surface of the substrate 102 including the partition wall 157 and the contact spacer 155.

In this case, since the organic light emitting layer 113 and the second electrode 115 are formed in a structure that is automatically separated for each pixel region P by the partition wall 157 without a separate mask process, the organic light emission layer is formed on the upper part of the partition wall 157. The material layer 113a and the second electrode material layer 115a may be left in order.

The first and second electrodes 111 and 115 and the organic light emitting layer 113 formed therebetween form an organic light emitting diode (E).

Accordingly, the organic light emitting diode E is electrically connected to the connection electrode 217 formed on the first substrate 101 through the contact spacer 155.

Here, the organic light emitting layer 113 may be composed of a single layer made of a light emitting material, and in order to increase the light emitting efficiency, a hole injection layer, a hole transporting layer, an electron transporting layer and an electron transporting layer It may further include multiple layers of an electron injection layer.

In addition, the second electrode 115 is made of aluminum (Al) or aluminum alloy (AlNd), which is a metal material having a relatively low work function, in order to serve as a cathode.

When a predetermined voltage is applied to the first electrode 111 and the second electrode 115 according to the selected color signal, the dual panel type OLED 300 may inject holes and second electrodes (injected into the first electrode 111). The electrons provided from 115 are transported to the organic light emitting layer 113 to form excitons, and when these excitons transition from the excited state to the ground state, light is generated and emitted in the form of visible light.

In this case, since the emitted light passes through the transparent first electrode 111 to the outside, the OLED 300 implements an arbitrary image.

In particular, the dual panel type OLED 300 according to the second embodiment of the present invention is characterized in that a seal layer 120 is formed between the driving thin film transistor DTr and the organic light emitting diode E.

The seal layer 120 may be formed of a combination of an epoxy resin, a phenol resin, an acrylic resin, a thermal and photocurable resin, and an organic binder.

Thus, the seal layer 120 is formed to completely cover the organic light emitting diode (E), thereby preventing or slowing the water ingress into the organic light emitting diode (E), thereby preventing the organic light emitting layer sensitive to moisture and oxygen ( 113 may prevent contact with moisture.

That is, through the seal layer 120, it is possible to prevent the contamination source such as moisture or gas from the outside from penetrating into the organic light emitting diode E.

In addition, the seal layer 120 according to the second embodiment of the present invention includes a filler (E-filler) 121 having electrical characteristics, and the driving thin film transistor DTr and the second formed on the first substrate 101. The organic light emitting diode E formed on the substrate 102 is prevented from being electrically disconnected.

That is, even though the seal layer 120 is interposed between the connection electrode 217 on the first substrate 101 and the second electrode 115 formed on the second substrate 102 through the contact spacer 155, they are electrically connected to each other. Is connected.

This is because the seal layer 120 includes a filler (E-filler) 121 having electrical characteristics.

The filler 121 may be formed of carbon black particles, carbon nanotubes, or the like, and may include a driving thin film transistor DTr and a second substrate formed on the first substrate 101 by the filler 121. The electrical connection of the organic light emitting diode E formed on the surface 102 may be improved.

In addition, the dual panel type OLED 300 according to the second embodiment of the present invention may also be formed as a seal pattern 200 formed at an edge thereof in the process of bonding the first and second substrates 101 and 102. Using a metal seal pattern containing a material, it is characterized in that the encapsulation (encapsulation).

In addition, first and second metal patterns 210a and 210b are formed on the first and second substrates 101 and 102 corresponding to the metal seal pattern 200 to improve the interface characteristics of the metal seal pattern 200. do.

In this case, the first and second metal patterns 210a may be formed of a material used for forming a switching and driving thin film transistor (DTr), or may be formed as a single layer or a multilayer using a separate metal material.

Alternatively, the second metal pattern 210b may be formed of a conductive material used to form the organic light emitting diode E, or may be formed as a single layer or multiple layers of a separate metal material.

Therefore, according to the second embodiment of the present invention, the organic light emitting diode (E) primarily protects the pollutant from the outside by the metal seal pattern 200, and also the moisture and gas by the seal layer 120. Secondary defenses against the same pollutant.

Through this, the degradation of the organic light emitting diode E can be prevented and the lifespan of the dual panel OLED 300 can be extended. In addition, by firmly bonding the first and second substrates (101, 102) to reduce the failure rate generated after the bonding to reduce the overall cost and material cost loss and improve the production yield.

In addition, in the dual panel type OLED 300 according to the second embodiment of the present invention, even when a pressure such as pressing from the outside is applied, the pressing of the dual panel type OLED 300 does not occur by the seal layer 120, so that the organic light emitting diode Cracking of the first and second electrodes 111 and 115 or the driving thin film transistor DTr of (E) can be prevented.

As a result, problems such as dark spot defects may be prevented from occurring, thereby preventing the problem of uneven brightness or image characteristics.

In particular, the seal layer 120 may include a filler (E-filler) 121 having electrical characteristics, such that the driving thin film transistor DTr formed on the first substrate 101 and the organic field formed on the second substrate 102 are formed. The electrical connection of the light emitting diodes E can be improved.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a cross-sectional view schematically showing a cross section of a typical active matrix OLED.

2 is a cross-sectional view schematically showing an OLED according to a first embodiment of the present invention;

3 is an enlarged cross-sectional view of a portion of FIG. 2;

Figure 4 is a plan view schematically showing a state in which the metal seal pattern and the seal layer is formed in accordance with a first embodiment of the present invention.

5A to 5H are cross-sectional views of manufacturing steps of an OLED according to a first embodiment of the present invention.

6 is a cross-sectional view showing a portion of a dual panel type OLED according to a second embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of a portion of FIG. 6. FIG.

Claims (11)

First and second substrates defining a display area including a plurality of pixel areas and a non-display area surrounding the display area; A driving thin film transistor and an organic light emitting diode formed between the first and second substrates; A seal layer interposed between the first and second substrates; First and second metal patterns respectively formed along the non-display area; A metal seal pattern formed between the first and second metal patterns Organic electroluminescent device comprising a. The method of claim 1, The seal layer is an organic electroluminescent device comprising a combination of an organic binder and one selected from an epoxy resin, a phenol resin, an acrylic resin, a heat and a photocurable resin. The method of claim 1, The metal seal pattern is an organic light emitting device in which a viscous solvent and metal particles are mixed. The method of claim 3, wherein The metal particles are indium (In), tin (Sn), zinc (Zn), lead (Pb), silver (Ag), gold (Au), aluminum (Al), aluminum alloy (Al alloy), copper (Cu) , An organic electroluminescent device comprising one selected from molybdenum (Mo), molybdenum alloy (Mo alloy), tungsten (W), tungsten, titanium (Ti), bismuth (Bi). The method of claim 1, The first metal pattern is formed of a conductive material used to form the driving thin film transistor, or an organic light emitting device formed of a single layer or multiple layers of a separate metal material. The method of claim 1, The second metal pattern may be formed of a conductive material used to form the driving thin film transistor, or may be formed of a conductive material used to form the organic light emitting diode, or may be formed of a single layer or multiple layers of a separate metal material. . The method of claim 1, The driving thin film transistor and the organic light emitting diode are formed on the first substrate. The method of claim 1, The driving thin film transistor is formed on the first substrate, and the organic light emitting diode is a dual panel type organic light emitting device formed on the second substrate. The method of claim 8, And the driving thin film transistor and the organic light emitting diode are electrically connected to each other through a contact spacer. The method of claim 8, The seal layer is an organic light emitting device comprising a filler (E-filler) having an electrical characteristic. 11. The method of claim 10, The filler is an organic electroluminescent device which is selected from carbon black particles or carbon nanotubes.

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