KR20110035444A - Method of fabricating for dual panel type organic electro-luminescent device - Google Patents

Abstract

PURPOSE: A method for manufacturing an organic electro-luminescent device is provided to form a concavo-convex shape in a part contacting a frit pattern, thereby increasing the adhesion force between a second substrate and the frit pattern. CONSTITUTION: A first substrate(101) forms a display area including a pixel area and a non display area surrounding the display area. A driving thin film transistor and an organic electro-luminescent diode are formed on the pixel area of the first substrate. A frit pattern(300) is formed along with the outline of the first substrate. A second substrate(102) includes an oxide silicon layer on one side facing the first substrate.

Description

Method of manufacturing organic electroluminescent device {Method of fabricating for dual panel type organic electro-luminescent 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-luminescence 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, it has better viewing angle and contrast ratio than liquid crystal display, and is advantageous in terms of power consumption. It is also possible to drive DC low voltage, has fast response speed, and is strong against external shock because its internal components are solid. 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.

In recent years, the passive matrix type has many limited elements such as resolution, power consumption, and lifespan. Accordingly, active matrix type OLEDs capable of realizing high resolution and large screens have been actively studied.

1 is a view schematically showing a cross section of a general active matrix type 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. The edges thereof are spaced apart and sealed through a failure pattern 20.

In detail, the driving thin film transistor DTr is formed in each pixel area on the first substrate 1, and the first electrode 3 and the first electrode 3 connected to each driving thin film transistor DTr are formed. The organic light emitting layer 5 which emits light of a specific color on the electrode 3 and the second electrode 7 are formed on the organic light emitting layer 5.

The organic light emitting layer 5 expresses colors of red, green, and blue. In general, separate organic materials 5a, 5b, and 5c emitting red, green, and blue colors are used for each pixel.

The first and second electrodes 3 and 7 and the organic light emitting layer 5 formed therebetween form an organic light emitting diode. In this case, the OLED 10 having such a structure configures the first electrode 3 as an anode and the second electrode 7 as a cathode.

In addition, a moisture absorbent (not shown) is formed on the inner surface of the second substrate 2 to block external moisture.

On the other hand, the failure turn 20 of the OLED 10 is usually made of a sealant made of an organic or polymer material, the sealant is such that the pore between the molecule and the molecule enough to move the water molecules due to its internal molecular structure characteristics It becomes the size.

Therefore, as time passes, it penetrates into the OLED 10 through the pollutant seal pattern 20 such as external moisture or gas, and the penetrated sources exist inside the sealed OLED 10. The organic electroluminescent diode (E), which is very sensitive to moisture and oxygen, is modified.

That is, pollutants penetrated from the outside penetrate into the organic light emitting layer 5 of the organic light emitting diode E, and thus, the organic light emitting layer 5 may degrade the light emitting characteristics of the organic light emitting layer 5 by the pollutant. The life of the organic light emitting layer 5 is shortened. In addition, black spots are generated by blocking sources in some areas.

Therefore, in order to solve such a problem, an OLED 10 has been recently proposed, which forms a frit pattern made of an inorganic material frit.

Since the frit pattern is smaller than the water molecule due to its material property, it is much superior to the seal pattern of the sealant material in terms of preventing moisture from penetrating from the outside, thereby improving the lifespan of the organic light emitting device by preventing degradation due to moisture infiltration. Can be extended.

However, the frit pattern has a disadvantage in that the adhesion to the substrate is low while being excellent in moisture prevention.

This results in poor peeling of the first and second substrates of the OLED, which lowers process yield and lowers the reliability of the OLED.

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, the second object is to prevent peeling defects of the first and second substrates and to improve process yield and reliability.

In order to achieve the above object, the present invention provides a display device comprising: a first substrate having 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 in the pixel region of the first substrate; A frit pattern formed in the non-display area of the first substrate and formed along an edge of the first substrate; And a second substrate facing the first substrate and having a silicon oxide layer formed on one surface facing the first substrate, wherein the frit pattern is in contact with the silicon oxide layer of the second substrate. do.

The frit pattern is made of an inorganic material frit, and the second substrate is made of glass.

In addition, the silicon oxide layer is formed by plasma treatment of one surface of the second substrate with oxygen (O ₂ ), and the silicon oxide layer in contact with the frit pattern of the second substrate has an uneven shape.

In addition, a protective layer is formed between the organic light emitting diode and the driving thin film transistor, and the frit pattern is formed in contact with the protective layer over the protective layer.

The present invention also provides a method comprising forming a driving thin film transistor and an organic light emitting diode in a display area of a first substrate defined in a display area and a non-display area surrounding the display area; Forming a frit pattern along the edge of the first substrate in the non-display area of the first substrate; Forming an silicon oxide layer by performing oxygen (O ₂ ) plasma treatment on a second substrate facing the first substrate; Forming a concave-convex shape on the silicon oxide layer in the non-display area; Facing the first substrate and the second substrate so that the frit pattern corresponds to the uneven shape; And irradiating a laser beam corresponding to the frit pattern, thereby bonding the frit pattern to the second substrate.

In this case, the concave-convex shape is formed by exposing the second substrate to an etchant and etching, and forming a protective layer on the entire surface between the driving thin film transistor and the organic light emitting diode.

In addition, the frit pattern is formed on the protective layer.

As described above, according to the present invention, a feature of the present invention is to encapsulate and bond the first and second substrates through a frit pattern made of an inorganic material frit, and in particular, oxygen (O ₂₎ on the inner surface of the second substrate. A silicon oxide layer is formed through plasma surface treatment, and a portion of the silicon oxide layer is formed in an uneven shape to improve the adhesion between the second substrate and the frit pattern.

As a result, the first and second substrates may be tightly sealed, and contaminants such as moisture or gas from the outside may be separated into spaces between the first and second substrates. It is effective to prevent penetration into spaced spaces.

Therefore, there is an effect that can prevent degradation of the organic light emitting diode and extend the life of the OLED. In addition, by firmly bonding the first and second substrates 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.

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

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

As illustrated, the OLED 100 according to the present invention includes a first substrate 101 having a driving and switching thin film transistor DTr (not shown) and an organic light emitting diode E, and a first substrate 101. Facing and composed of a second substrate 102 for encapsulation, the first and second substrates 101 and 102 are spaced apart from each other, the edge portion thereof is sealed through a frit pattern (300) and bonded together do.

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

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 active region 201a of the semiconductor layer 201.

In addition, a first interlayer insulating film 207a is formed on the entire surface of the gate electrode 205 and the gate wiring (not shown). At this time, the first interlayer insulating film 207a and the gate insulating film 203 below are formed in an active region ( 201a) first and second semiconductor layer contact holes 209a and 209b exposing the source and drain regions 201b and 201c located at both sides thereof, respectively.

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.

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

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.

Although not shown in the drawing, data wirings (not shown) defining pixel areas 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 and driving thin film transistor (DTr) shows, as an example, a top gate type in which the semiconductor layer 201 is made of a polysilicon semiconductor layer, as an example of pure and impurity amorphous. It may be formed of a bottom gate type made of silicon.

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

The first electrode 111 is connected to the drain electrode 213 of the driving thin film transistor DTr.

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

Accordingly, the first electrode 111 may be formed of indium tin oxide (ITO), which is a material having a relatively high work function to serve as an anode.

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.

Therefore, the light emitted from the organic light emitting layer 113 is driven by the bottom emission method emitted toward the first electrode 111.

In addition, the organic light emitting layer 113 may be formed 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 emitting material layer, an electron It may be composed of multiple layers of an electron transporting layer and an electron injection layer.

Accordingly, 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 inject holes and second electrodes 115 injected from the first electrode 111. Electrons applied from the organic light emitting layer 113 are transported to form an exciton, and when the exciton transitions 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 first electrode 111 to the outside, the OLED 100 implements an arbitrary image.

Meanwhile, the first electrode 111 is formed for each pixel region P, and a bank 221 is positioned between the first electrodes 111 formed for each pixel region P. FIG.

That is, the bank 221 is formed in a matrix type having a lattice structure as a whole of the substrate 101, and the first electrode 111 is separated into pixel regions P with the bank 221 as a boundary portion for each pixel region. Formed.

In particular, the present invention, as described above, in the process of bonding the first and second substrates 101 and 102, the edge portion thereof is sealed through the frit pattern 300 and bonded.

Through this, the OLED 100 is encapsulated.

At this time, the frit pattern 300 is made of a frit, which is an inorganic material, the pore size is smaller than the water molecule due to its material properties, in terms of preventing moisture from penetrating from the outside of the seal pattern of the conventional organic or polymer material (60 in FIG. Since it is much better than), it is possible to extend the life of the organic light emitting diode (E) by preventing degradation due to moisture infiltration.

Meanwhile, the first and second substrates 101 and 102 of the present invention are made of a transparent insulating material of glass or plastic, wherein the inner surface of the second substrate 102 for encapsulation of the present invention, that is, the organic If one surface facing the electroluminescent diode E is defined as an inner surface, the silicon oxide (SiO ₂ ) layer 320 is formed on the inner surface of the second substrate 102.

Thus, one end of the frit pattern 300 of the present invention is not in direct contact with the second substrate 102, but in direct contact with the silicon oxide layer 320, so that the frit pattern 300 and the second substrate 102 are in direct contact with each other. The adhesion between them is improved.

Looking at this in more detail, the frit pattern 300 itself is a component that makes up the glass has a very excellent adhesive strength with the inorganic insulating material layer or the glass substrate.

At this time, the adhesion to the substrate made of glass material depends on the oxygen (O ₂ ) component, that is, the silicon (Si) material contained in the inorganic material of the frit pattern 300 is the glass material of the substrate 102. The more covalent bonds with oxygen (O ₂ ) contained in the adhesive force between the frit pattern 300 and the substrate 102 are improved. (Bonding force between silicon and oxygen -110 kcal / mol)

However, the silicon (Si) material of the frit pattern 300 is more bonded to nitrogen (N) than oxygen (O ₂ ) contained in the glass material.

Thus, the adhesion between the frit pattern 300 and the substrate 102 made of a glass material is lowered. (Bonding force between silicon and nitrogen -150 kcal / mol)

In particular, the frit pattern 300 is formed on the second interlayer insulating film 207b of the first substrate 101 so that one end of the frit pattern 300 adhered to the first substrate 101 of the frit pattern 300 is made of an inorganic insulating material. By contacting the two-layer insulating film 207b, the bonding force between the frit pattern 300 and the first substrate 101 is very high.

However, the other end bonded to the second substrate 102 of the frit pattern 300 is in direct contact with the second substrate 102 made of glass, and thus, the bonding force between the other end of the frit pattern 300 and the second substrate 102. Is lower than the bonding force between the frit pattern 300 and the first substrate 101, resulting in poor peeling of the first and second substrates 101 and 102.

Accordingly, the present invention forms the silicon oxide layer 320 on one surface of the second substrate 102 in contact with the other end of the frit pattern 300, so that the other end of the frit pattern 300 is directly connected to the silicon oxide layer 320. By contacting, the bonding force between the frit pattern 300 and the second substrate 102 is improved.

The silicon oxide layer 320 is formed by plasma surface treatment with oxygen (O ₂ ) on the inner surface of the second substrate 102.

In addition, the inner surface edge of the second substrate 102 is formed as a concave-convex shape 330 consisting of a concave portion and a convex portion, which is to widen the adhesion area between the second substrate 102 and the frit pattern 300.

Through this, the second substrate 102 further improves the adhesive force with the frit pattern 300.

As described above, the OLED 100 of the present invention encapsulates and bonds the first and second substrates 101 and 102 through a frit pattern 300 formed of an inorganic material frit, thereby forming the first and second substrates ( 101, 102 will be more tightly sealed.

Through this, contaminants such as moisture or gas penetrate into the spaced space between the first and second substrates 101 and 102 from the outside into the spaced space between the first and second substrates 101 and 102. Can be prevented.

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.

Hereinafter, an encapsulation process of the OLED 100 according to an embodiment of the present invention will be described.

3A to 3E are cross-sectional views of manufacturing steps of encapsulation of an OLED according to an embodiment of the present invention.

First, as shown in FIG. 3A, an amorphous silicon layer (not shown) is formed by depositing amorphous silicon in the pixel region P of the first substrate 101, and irradiating a laser beam or performing heat treatment thereon. To crystallize the amorphous silicon layer into a polysilicon layer (not shown).

Subsequently, the polysilicon layer (not shown) is patterned by performing a mask process to form the semiconductor layer 201 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 201 of pure polysilicon to form a gate insulating film 203.

Thereafter, a low-resistance metal material such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), or copper alloy is deposited on the gate insulating layer 203 to form a first metal layer (not shown). The mask process is performed to form the gate electrode 205 corresponding to the central portion of the semiconductor layer 201.

Next, the dopant, i.e., trivalent or pentavalent element, is doped on the entire surface of the substrate 101 by using the gate electrode 205 as a blocking mask, so that impurities in the portion of the semiconductor layer 201 located outside the gate electrode 205 are removed. The doped source and drain regions 201b and 201c are formed, and portions corresponding to the doped gate electrodes 205 form the active region 201a of pure polysilicon.

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

Subsequently, a metal material such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, chromium (Cr), and molybdenum (Mo) is deposited on the first interlayer insulating layer 207a. Source and drain electrodes 211 in contact with the source and drain regions 201b and 201c through the first and second semiconductor layer contact holes 209a and 209b by forming a metal layer (not shown) and patterning by performing a mask process. , 213).

In this case, the semiconductor layer 201, the gate insulating film 203, the gate electrode 205, and the first interlayer insulating film 207a are separated from each other and the source and drain electrodes 211 and 213 form a driving thin film transistor DTr.

Next, a frit paste, the main component of which is an inorganic material, is applied to the non-display area NA outside the pixel area P of the first substrate 101 in a wiring form without discontinuity by using a dispensing device, thereby providing a first shape. A frit pattern 300 bordering the edge of the substrate 101 is formed.

The frit pattern 300 is formed on the second interlayer insulating film 207b formed on the first substrate 101, wherein the frit paste is viscous in addition to the frit, which is a main component, to enable dispensing through the dispensing device. It is preferable to include an organic material having a volatile property and having a volatilization property.

Thereby, the 1st board | substrate 101 of OLED (100 of FIG. 2) is completed.

Next, as shown in FIG. 3B, an organic light emitting diode formed on the inner surface of the second substrate 102, that is, on the first substrate 101 (FIG. 3A) in a bonding process with the first substrate 101 (FIG. 3A). Surface treatment of F-SAMs (fluor-self assembled monolayers) such as oxygen (O ₂ ) plasma surface treatment is performed on one surface facing (E) of FIG. 3A.

As a result, a silicon oxide layer 320 is formed on the inner side surface of the second substrate 102, and thus the adhesive force with the frit pattern (300 in FIG. 3A) that is in direct contact with the inner side surface of the second substrate 102. Will improve.

Next, as shown in FIG. 3C, an uneven shape 330 is formed along the edge of the silicon oxide layer 320.

The concave-convex shape 330 is formed by an etching process, and the concave-convex shape 330 is formed of a concave portion and a convex portion, and the adhesion area between the second substrate 102 and the frit pattern (300 in FIG. 3A). To widen.

Through this, the OLED of the present invention (100 of FIG. 3A) is more firmly bonded to the second substrate 102 and the frit pattern (300 of FIG. 3A).

Next, as shown in FIG. 3D, the first thin film transistor DTr, the first substrate 101 on which the organic light emitting diode E is formed, and the second substrate 101 on which the silicon oxide layer 320 are formed face each other. After positioning so that the frit pattern 300 formed on the first substrate 101 is brought into contact with the concave-convex phase 330 formed along the edge of the silicon oxide layer 320 of the second substrate 102.

Next, as shown in FIG. 3E, the frit pattern 300 is instantaneously melted and solidified by irradiating the laser beam LB using the laser irradiation apparatus 400 corresponding to the frit pattern 300. The pattern 300 is bonded to the concave-convex shape 330 of the second substrate 102, thereby completing the OLED 100 according to the embodiment of the present invention.

In this case, since the frit pattern 300 prevents the passage of moisture due to the intermolecular pores much smaller than the water molecules, the frit pattern 300 made of such a material forms a perfect moisture barrier pattern.

Therefore, the OLED 100 of the present invention encapsulates and bonds the first and second substrates 101 and 102 through the frit pattern 300 made of the frit, which is an inorganic material, and particularly, the inside of the second substrate 102. The silicon oxide layer 320 is formed on the side surface through oxygen (O ₂ ) plasma surface treatment, and a part of the silicon oxide layer 320 is formed into the uneven shape 330 by contacting the frit pattern 300, thereby forming the second substrate 102 and the frit pattern. It is to improve the adhesion of the 300.

As a result, the first and second substrates 101 and 102 may be tightly sealed, and thus, water or gas may be separated from the outside into spaces between the first and second substrates 101 and 102. It is possible to prevent the contaminant such as penetrating into the space between the spaced apart of the first and second substrate (101, 102).

Therefore, deterioration 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 bonding to reduce the overall cost and material cost loss and improve the production yield.

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 schematic cross-sectional view of a typical active matrix OLED.

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

3A-3E are cross-sectional views of manufacturing steps of encapsulation of an OLED according to an embodiment of the present invention.

Claims (11)

A first substrate having 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 in the pixel region of the first substrate; A frit pattern formed in the non-display area of the first substrate and formed along an edge of the first substrate; A second substrate facing the first substrate and having a silicon oxide layer formed on one surface facing the first substrate The frit pattern includes an organic light emitting diode in contact with the silicon oxide layer of the second substrate. The method of claim 1, The frit pattern is an organic light emitting device consisting of a frit inorganic material. The method of claim 1, The second substrate is an organic light emitting device of a glass material. The method of claim 1, The silicon oxide layer is formed by plasma treatment of one surface of the second substrate with oxygen (O ₂ ). The method of claim 1, The silicon oxide layer in contact with the frit pattern of the second substrate has an uneven shape. The method of claim 1, An organic light emitting diode having a protective layer formed between the organic light emitting diode and the driving thin film transistor. The method of claim 6, The frit pattern is formed in contact with the protective layer on the protective layer. Forming a driving thin film transistor and an organic light emitting diode in the display area of the first substrate defined in the display area and the non-display area surrounding the display area; Forming a frit pattern along the edge of the first substrate in the non-display area of the first substrate; Forming a silicon oxide layer by oxygen (O ₂ ) plasma treatment on a second substrate facing the first substrate; Forming a concave-convex shape on the silicon oxide layer in the non-display area; Facing the first substrate and the second substrate so that the frit pattern corresponds to the uneven shape; Irradiating a laser beam corresponding to the frit pattern so that the frit pattern is bonded to the second substrate Method for producing an organic electroluminescent device comprising a. The method of claim 8, The uneven shape is a method of manufacturing an organic light emitting device is formed by etching the second substrate exposed to the etching solution. The method of claim 8, And a protective layer formed on a front surface between the driving thin film transistor and the organic light emitting diode. 11. The method of claim 10, The frit pattern is a manufacturing method of an organic light emitting device is formed over the protective layer.

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