KR20050005085A - Organic electroluminescence device and fabricating method thereof - Google Patents

Abstract

PURPOSE: An organic electroluminescence device and a method are provided to achieve improved adhesive force between a sealant and a substrate by forming an inorganic insulation film on a pad electrode. CONSTITUTION: An organic electroluminescence device comprises a pad electrode(118) for applying voltages to an anode and a cathode; a sealing cap having a sealing surface adhered to a sealing portion(120) formed on a certain part of the pad electrode; and an inorganic insulation film(130) formed on the pad electrode. The inorganic insulation film is made of SiO2.

Description

Organic electroluminescent device and its manufacturing method {Organic electroluminescence device and fabricating method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device (OELD, hereinafter referred to as an "organic EL device") and a method of manufacturing the same. More specifically, an inorganic insulating film is formed on the pad electrode to form an additional sealing agent and a substrate. The organic electroluminescent device which improved the adhesive force of and its manufacturing method are related.

In organic electroluminescence, electrons and holes injected through a cathode and an anode are recombined to form an exciton in an organic (low molecular or polymer) thin film, and light having a specific wavelength is generated by energy from the excitons formed. This is a phenomenon that occurs.

The organic electroluminescent device using such a phenomenon has the following basic structure. The basic configuration of the organic EL device includes a transparent substrate, an anode arranged in a stripe shape on the transparent substrate, an insulating layer and an insulating layer formed separately from each other with a gap corresponding to a cell region. A barrier rib, an organic electroluminescent layer, and a metal electrode layer, which is a cathode, are deposited.

The organic electroluminescent layer may include a hole transport layer that transports holes injected from an anode to a light emitting layer; An emission layer, which is an area where light emission occurs while recombination of holes and electrons supplied from the anode and the cathode is performed; And a structure in which an electron transport layer for smoothly transporting electrons supplied from the cathode is sequentially stacked. In some cases, a hole injection layer and an electron injection layer may be further stacked in the device to facilitate injection of holes and electrons.

In order to manufacture the organic EL device, first, the ITO layer is patterned into a stripe shape by photolithography on a transparent substrate on which Indium Tin Oxide (ITO) is deposited. The anode is prepared by patterning. Thereafter, the insulating layer and the partition wall are laminated by photolithography on the patterned ITO layer as needed, and the formation of the device is completed by sequentially depositing the organic material layer and the metal electrode layer sequentially.

In the device formed as described above, the intersection of the anode and the cathode forms a pixel which is a unit for emitting light, and the anode and the cathode are connected to a pad electrode to apply a voltage to the pixel. Accordingly, the pixel may emit red (R), green (G), and blue (B) as a signal through the pad electrode, thereby realizing a full color.

In organic EL devices, if there is a reactive gas (oxygen or moisture) inside the panel, the organic material or the metal electrode laminated is oxidized, and therefore, the sealing cap should be filled with an inert gas. Will be attached. As shown in FIG. 1, a seal line is generally formed by using a nozzle or dispensing epoxy, which is a sealing agent, between the edge portion of the transparent substrate 10 and the active region 14. 12), the sealing cap is brought into close contact with the substrate on which the seal line 12 is formed, and UV light of 360 nm to 380 nm is irradiated for a few minutes to several tens of minutes on the glass substrate to cure the sealing agent to fix the sealing cap to form a predetermined closed space. Form. Therefore, when the sealing is excellent, the device located in the sealed space may not be affected by the external environment such as moisture.

However, in the case of the organic EL element, numerous metal pad electrodes are formed at the edge portion of the substrate on which the seal line portion is to be formed, and the epoxy is covered on the metal pad electrodes. At this time, as shown in FIG. 2, there may occur a case where sealing is not performed properly at the corner portion of the patterned pad electrode (in the enlarged view of FIG. 2, a small circular portion between the metal pad electrodes may be a sealing failure portion of the corner portion). ). Poor sealing of the corner portion may result in a lack of interfacial adhesion between the substrate and the sealing cap, which may cause impurities to penetrate and cause contamination of the device, and peeling of the sealing cap may occur.

Accordingly, the inventors have intensively studied to solve the above problems, and as a result, when the inorganic insulating film (for example, SiO _2, etc.) having good adhesion is formed on the pad electrode of the sealing portion, the adhesion between the sealing material and the substrate is reduced. It has been found to be enhanced to improve the life of the device and to complete the present invention.

Accordingly, an object of the present invention is to solve the problems caused by the sealing of the conventional organic EL device, and to provide an organic EL device by coating an upper surface of a pad electrode with an inorganic insulating film and having a sealing portion formed thereon. do.

1 is a schematic plan view of a device showing a pad electrode portion of a conventional organic electroluminescent device;

2 is a cross-sectional view of a pad electrode unit of the organic electroluminescent device of FIG. 1;

Figure 3 is a cross-sectional view of the pad electrode portion of the organic electroluminescent device according to the present invention.

*** Explanation of symbols for the main parts of the drawing ***

10, 110: transparent substrate 12, 20, 120: sealing part

14 active region 16 pad electrode portion

18, 118: pad electrode 130: inorganic insulating film layer

In order to achieve the above object, the present invention is an organic electroluminescent device comprising a pad electrode for applying a voltage to the anode and the cathode and a sealing cap is attached to the sealing portion formed on a portion of the pad electrode, the pad An organic EL device is provided in which an inorganic insulating film is formed on an electrode upper surface, preferably a portion upper surface on which a sealing portion is to be formed.

Preferably, the inorganic insulating film may be made of SiO ₂ .

The present invention also provides a method for forming an anode layer on a substrate, the anode layer being separated at predetermined intervals; Forming a pad electrode at an edge portion of the anode; Forming an inorganic insulating film on an upper surface of a portion of the pad electrode in which the sealing portion is to be formed; And forming an organic layer and a cathode in the active region of the substrate.

In the method of the present invention, the inorganic insulating film may be formed by a sputtering method, a plasma enhanced chemical vapor deposition (PECVD), a dispensing method or a printing method. When the inorganic insulating film is formed by the sputtering method, the inorganic insulating material may be sputtered and deposited only on a portion where the sealing portion is formed using a hard mask. This is convenient because no additional patterning process is required. In addition, when the inorganic insulating film is formed by the PECVD method, the inorganic insulating material may be coated on the entire substrate by PECVD, and then the inorganic insulating film may be patterned only at a portion where the sealing portion is formed by a photolithography method.

In the manufacture of the organic EL element, an insulating layer is usually formed on the patterned ITO layer to separate each pixel. As the insulating layer, an organic material such as polyimide-based organic material or SiO ₂ may be used. Accordingly, when the insulating layer is formed of the same material as the inorganic insulating layer, the inorganic insulating layer may be formed simultaneously with forming the insulating layer. For example, an inorganic insulating material may be formed on the entire surface of the substrate and patterned to simultaneously form an insulating layer in the active region of the substrate and an inorganic insulating layer in the edge portion.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by them in any way.

Example 1

As shown in FIG. 3, an anode was formed by first performing a photolithography process on the glass substrate 110 on which the ITO layer was deposited, by patterning the ITO layer in a stripe form. The pad electrode portion is formed 118 on the anode patterned at the edge portion of the substrate 110 in a conventional manner. Then, the entire substrate was coated with SiO ₂ using PECVD and patterned by photolithography to form an insulating layer (not shown) and an inorganic insulating film 130 for separation of each pixel. Thereafter, an organic layer was sequentially deposited on the anode formed in the active region, and a cathode was deposited on the organic layer. After the epoxy portion of the substrate on which the organic material and the cathode are deposited is coated with an epoxy to form a sealing portion 120, the sealing cap is adhered to the substrate, and the sealing portion is cured by irradiating UV at 380 nm for 15 minutes. The device according to the invention was formed.

Example 2

An anode and a pad electrode part were formed in the same manner as in Example 1, and SiO ₂ was deposited by sputtering only on the pad electrode part where the sealing part is formed using a hard mask. Thereafter, the organic material layer and the cathode are deposited in the same manner as in Example 1, the sealing part is formed at the edge of the substrate, and then the sealing cap is attached to form the device according to the present invention.

In the organic EL devices of Examples 1 and 2 according to the present invention, by forming an inorganic insulating film on the pad electrode of the sealing portion in advance, the weak portion of the sealing of the pad electrode corner portion can be eliminated, and the sealing epoxy has high adhesive strength. Since the adhesive is not bonded to the weak metal electrode but adhered to the inorganic insulating film having good adhesion, the adhesion could be improved.

As can be seen from the above, the organic electroluminescent device of the present invention can eliminate the vulnerable part of the sealing of the pad electrode, improve the adhesion between the sealing agent and the substrate to prevent the penetration of external gas, etc. It can be improved.

Claims (7)

In the organic electroluminescent device comprising a pad electrode for applying a voltage to the anode and the cathode and a sealing cap is attached to the sealing portion formed on a portion of the pad electrode, And an inorganic insulating film formed on an upper surface of the pad electrode. The organic electroluminescent device according to claim 1, wherein the inorganic insulating film is made of SiO ₂ . Forming an anode layer separated on the substrate at predetermined intervals; Forming a pad electrode at an edge portion of the anode; Forming an inorganic insulating film on an upper surface of a portion of the pad electrode in which the sealing portion is to be formed; And Forming an organic layer and a cathode in the active region of the substrate. The method of claim 3, wherein the inorganic insulating layer is formed by a sputtering method, a plasma enhanced chemical vapor deposition (PECVD), a dispensing method, or a printing method. The method of claim 4, wherein the sputtering method sputters and deposits an inorganic insulating material only on a portion of the pad electrode where the sealing portion is formed using a hard mask. The organic electroluminescent device according to claim 4, wherein the PECVD method forms an inorganic insulating film only on the pad electrode portion where the sealing portion is formed by photolithography after coating the inorganic insulating material on the entire substrate by PECVD. Manufacturing method. 4. The method of manufacturing an organic electroluminescent element according to claim 3, wherein an insulating film is formed simultaneously on the surface of the anode layer in the active region of the device at the time of forming the inorganic insulating film.