KR20070090540A - Organic light emitting diode having functions of moisture-getting and hydrogen-discharging - Google Patents

Abstract

An organic light emitting diode with moisture-removing and hydrogen-discharging functions is provided to reduce a manufacturing error of the OLED(Organic Light Emitting Diode) by removing moistures and hydrogen from an inner space of the OLED. An organic light emitting diode(100) includes a moisture-removing unit(130) and a hydrogen-discharging unit(180). A sealing cap is arranged on a substrate(110). Mating edges between the substrate and the sealing cap are sealed by using a sealant, so that an inner space is formed. An organic light emitting unit(120) includes an organic light emitting layer and plural pixels having two electrode layers. The moisture-removing unit is arranged inside the inner space of the OLED and reacts with the moisture in the inner space to generate hydrogen. The hydrogen-discharging unit is arranged from the inner space to an external space, so that end portions of the hydrogen-discharging unit are exposed to the external space. The hydrogen-discharging unit absorbs the hydrogen from the inner space by using a concentration difference of the hydrogen between the inner and external spaces, and emits the absorbed hydrogen to the outside.

Description

Organic Light Emitting Diode Having Functions of Moisture-Getting and Hydrogen-Discharging}

1 to 8 relate to an OLED device according to the present invention, which shows an exemplary structure of an OLED device in which the water removal portion is disposed in the OLED device internal space and the hydrogen removal portion is extended from the internal space of the OLED device to the outside. It is a cross-sectional view.

9 is an enlarged view illustrating a detailed structure of an organic light emitting unit specified by a dotted line in FIG. 1.

* Description of the symbols for the main parts of the drawings *

100, 200, ..., 800: OLED element 110, 210, ..., 810: substrate

120, 220, ..., 820: organic light emitting unit 130, 230, ..., 830: moisture removing unit

140, 240, ..., 840: sealing layer 150, 250, ..., 850: insulating layer

170, 270, ..., 870: Sealant 180, 280, ..., 880: Hydrogen remover

285 and 585: Protective film 190 for hydrogen removal unit: Part of organic light emitting unit

The present invention relates to an organic light emitting diode (OLED) device, and more particularly, to an OLED device capable of effectively removing moisture and hydrogen present therein.

OLED devices are widely used as display devices of various information industrial devices because they have high resolution, high impact resistance, and various colors. There are two types of OLED devices, an active type and a passive type that can independently control the emission of each pixel. Active type is more used than passive type because it has lower driving voltage, less power consumption, and can produce screen of medium and large size.

In addition, according to the light output direction, the OLED device is classified into a top-emission type and a bottom-emission type. According to the general structure of the OLED device, the upper surface of the substrate is covered with a sealing layer (cap), and the facing edges of the substrate and the sealing layer are closed with a sealant, thereby providing a closed interior space therebetween. An organic light emitting part providing a plurality of pixels is disposed on an upper surface of the substrate in the inner space. Each pixel includes an organic light emitting layer (organic materials for which are well known to those skilled in the art) and first and second electrode layers disposed on both sides of the organic light emitting layer to apply voltage thereto. At least one of these two electrode layers needs to be light transmissive. These two electrode layers correspond to the anode and cathode of the conventional diode, respectively, and the positive terminal and the negative terminal of the power supply are respectively connected to the electrode layers of the anode and the cathode. Then, the positive charge hole and the negative charge electron are respectively scanned from the anode electrode layer and the cathode electrode layer to the organic light emitting layer, and the holes and the electrons recombine in the organic light emitting layer to emit light. The light passes through the transparent electrode layer and is emitted toward the substrate or the sealing layer. If the light-transmitting electrode layer is a low-level electrode disposed on the substrate side of the OLED device, it is called a bottom-emitting OLED device. On the contrary, if the light-transmissive electrode layer is an upper layer electrode disposed on the sealing layer side, a top-emitting OLED device is used. device). Among the plurality of pixels, light emission of the desired pixel can be controlled by switching the application of voltage to two electrode layers of the desired pixel.

However, excessive moisture or unnecessary gas in the internal space of the OLED device in which the organic light emitting unit is disposed may result in a bad result in the characteristics or lifespan of the OLED device. In particular, the OLED device is very sensitive to moisture. When the electrode and the organic light emitting layer constituting the pixel are exposed to the moisture, the OLED element is partially denatured or the light emission characteristic is changed, and as a result, the life of the device is significantly shortened. As a result, problems of performance deterioration such as pixel reduction of OLED elements occur. This phenomenon is called pixel shrinkage or edge growth.

Adhesive polymers, widely used as sealants, do not completely block moisture permeation but have minute permeability, allowing moisture to penetrate into the internal space from the outside of the device even during the use of OLED devices. Furthermore, depending on the material of the substrate or sealing layer used, moisture may penetrate into the device through it. In particular, during the sealing process of the OLED device, moisture may be absorbed by materials such as a substrate, an organic light emitting unit, and a sealing layer to penetrate into the inside. Moisture inside the device should be removed as quickly as possible to minimize problems such as pixel reduction. In preparing the water removal method, it is necessary to consider both the moisture introduced after sealing and the moisture quantum adsorbed to the material in the manufacturing process.

OLED devices with relatively large sizes are expected to be fabricated on flexible substrates. Flexible substrates are expected to include plastic-foils materials to meet the physical properties suitable for the intended application and to lower manufacturing costs. However, relatively inexpensive plastic flexible substrates are known to be ineffective in preventing moisture penetration. Therefore, for OLED devices employing such substrates, it is particularly important to provide a means for effectively removing moisture. . Therefore, a means for efficiently removing the moisture present inside the OLED element needs to be devised. In particular, since the amount of water flowing into the OLED device during the sealing process should be removed quickly at the beginning.

As a way to reduce the damage of the shortening of the lifetime due to the presence of water, it is known to place the OLED device with a water absorbent in a separate package and seal the package so that moisture does not penetrate into the device. The disadvantage is that the cost of such packaging to prevent moisture intrusion is a great burden and increases the size of the device and the installation area.

As another method for removing moisture inside an OLED device, a method of disposing a dehumidifying material inside the device is known. Dehumidifiers fall into two broad categories. One is a substance (moisture-absorbing dehumidifier) that absorbs moisture and removes it in a way that contains water itself. The other is a substance (moisture decomposition type dehumidifying agent) which does not absorb and contain moisture but removes moisture in such a manner as to generate hydrogen by reacting with and decomposing it. Either material can be used to make the water removal part, but the moisture absorbent dehumidifier increases its volume as the amount of water absorbed increases, increasing the internal pressure of the OLLED device, and peeling off the adhesion surface inside the device. It may cause problems. In addition, an increase in the internal pressure may cause the center portion to swell, which may cause a detrimental effect on the lifespan or light emission characteristics of the device. However, water-degradable dehumidifiers do not cause this problem. Rather, the water removal performance is better than the water absorption type, so the efficiency of preventing pixel reduction is high. It is more preferable to use a water-decomposable dehumidifying agent in this respect.

However, even in the case of using a water-decomposable dehumidifying agent, it should be taken into account that hydrogen is generated along with decomposition of water by the dehumidifying agent during operation of the OLED element. As long as moisture to be decomposed inside the device continues to flow, the amount of hydrogen generated increases proportionately. Like moisture, hydrogen also adversely affects the properties of OLED devices. In other words, if the amount of hydrogen present in the OLED device is excessively high, the pressure inside the OLED device may be increased to cause side effects.

Therefore, while maintaining the airtightness of the OLED device, it simultaneously and efficiently removes the moisture and hydrogen present in the inside of the device at the same time so that the amount of moisture and hydrogen present in the inside of the device does not adversely affect the characteristics of the device. There needs to be a way to make it work. In particular, in determining the materials of the substrate and the sealing layer constituting the case of the OLED device, the moisture permeability and the hydrogen permeability must be sufficiently considered,

An object of the present invention is to decompose and remove moisture present in the sealed interior of the OLED device and to discharge the hydrogen generated thereby to the outside of the device so that moisture or hydrogen does not accumulate in the device more than the allowable amount, excess moisture inside the device The present invention provides an improved OLED device capable of preventing defects such as shrinking of pixels due to hydrogen and maintaining excellent device characteristics.

According to a first aspect of the present invention for achieving the above object, a sealing layer (cap) is located on the substrate and the inner space sealed between them by sealing the substrate and the edges of the sealing layer facing the sealant is provided between them. And an organic light emitting part including a plurality of pixels composed of an organic light emitting layer and two electrode layers for applying a voltage to both sides thereof, the OLED device being disposed on the substrate in a sealed inner space, wherein the sealed inside of the OLED device A water decomposition type water removal unit disposed at a predetermined position of the space and reacting with water present in the internal space to generate hydrogen to decompose the water; And one side portion and the other side portion opposite to the inner space from the inner space of the OLED device to be exposed to the inner space and the outer space, respectively, and the concentration of hydrogen in the inner space and the outer space. There is provided an OLED device comprising a hydrogen removal unit for absorbing the hydrogen present in the inner space by the difference to be discharged to the outer space through itself.

In the OLED device, the hydrogen discharge capability of the hydrogen removal unit is preferably more than the amount of hydrogen generated by the decomposition of water by the water removal unit. In this case, the sealing layer includes, but is not limited to glass, a polymer material having a hydrogen permeability of 1.0x10 ^-16 [mole m / m ² · sec · Pa] or less, or a hydrogen permeability of 1.0x10 ^-10 [mole · m / m ² · sec · Pa ^0.5 ] or less. In addition, the hydrogen removal unit may be at least one of i) penetrating the center of the sealant, ii) passing between the sealant and the substrate, and iii) passing between the sealant and the sealing layer. It is preferred to be arranged.

According to a second aspect of the present invention for achieving the above object, an organic light emitting portion including at least a substrate and a plurality of pixels arranged on the substrate and in a matrix arrangement, wherein the pixels are disposed on both sides of the organic light emitting layer and In the OLED device consisting of two electrode layers for applying a voltage to the organic light emitting layer, the edge portion facing the substrate while covering all the organic light emitting portion on the substrate is sealed by a sealant is sealed between the substrate An encapsulation layer providing an internal space, wherein the organic light emitting part is located in the internal space; And a water decomposition type water removal unit disposed at a predetermined position of the enclosed inner space and reacting with water present in the inner space to generate hydrogen, and decomposing the water, in particular, the sealing layer has hydrogen permeability. It is made of a material and absorbs the hydrogen present in the inner space by the difference in concentration of hydrogen in the inner space and the outer space to pass through itself to be discharged to the outer space, An OLED device is provided which has a hydrogen discharge capacity that is greater than the amount of hydrogen generated due to decomposition.

In the OLED device according to the second aspect, the sealing layer is preferably composed of a metal layer made of a transition metal or an alloy containing the same or a polymer layer laminated on the metal layer and an inner surface thereof.

The OLED device according to the second aspect further includes a hydrogen removal unit for absorbing the hydrogen present in the inner space by the difference in concentration of hydrogen in the inner space and the outer space to be discharged to the outer space through itself. It is preferable. The hydrogen removal unit i) Penetrating in the middle of the sealant, ii) passing between the sealant and the substrate, and iii) passing between the sealant and the sealing layer, both ends of the OLED It is preferable to be disposed so as to be exposed to the internal space and the external space of the device, respectively.

In the OLED device according to the first aspect or the second aspect, the hydrogen removing unit 1.0x10 ^-11 at room temperature, the hydrogen permeability ^{[mole · m / m 2 ·} sec · Pa 0 .5] greater than the metal or metal It is preferable to make an alloy as a main raw material. In this case, it is preferable that the powder of the metal or the alloy of the metal is mixed with the polymer to form a thin film. At this time, it is preferable that the content of the polymer is 90 vol% or less. The polymer is preferably a thermoplastic resin or a reactive curable resin having a water transmittance (MVTR) of 10 g · mil / m ² · day or more at a temperature of 40 ° C. and 75% RH (relative humidity). Representative main raw materials capable of making the hydrogen removal portion is any one metal or any one selected from the group consisting of Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium) The alloy containing the above is mentioned. The hydrogen removing unit may be formed by sputtering the metal on at least one surface of the sealing layer and the substrate. In addition, a protective film may be applied to at least one surface of the hydrogen removing part exposed to the inner space and the outer space thereof to prevent damage or modification of the hydrogen removing part.

Meanwhile, in the OLED device according to the first side or the second side, the water removing unit is made in a thin film form using a mixture of a metal hydride, at least one powder of a metal and a polymer, and any position in the internal space. It is preferably attached to. The metal for the water removal part is preferably selected from metals having a greater ionization tendency than zinc. Examples of the metal hydride for the water removal unit are alkali metal hydrides, alkaline earth metal hydrides, alkali metal hydrides including boron or aluminum, alkaline earth metal hydrides including boron or aluminum, and At least one selected from the group which consists of these mixtures is mentioned.

The OLED device according to the first side or the second side may further include an insulating layer covering the upper electrode layer exposed to the internal space among the two electrode layers of the organic light emitting unit so as to be insulated from the surroundings. The insulating layer may be at least one of an inert gas filled in the empty space in contact with the upper electrode layer, an insulating liquid film or a solid thin film covering the upper electrode layer and blocking contact with other surroundings.

The OLED device according to the first or second aspect is an active type having a thin film transistor (TFT) capable of independently controlling the voltage supply to each pixel, wherein the sealing layer is made of a transparent material and the organic light emitting part Any one of a top emission type in which output light is emitted toward the sealing layer and a bottom emission type in which the substrate is made of a transparent material and the output light is emitted toward the substrate.

On the other hand, according to a preferred configuration of the OLED device according to the invention, the OLED device, the substrate; A TFT layer disposed on the substrate and including at least as many pixels as a thin film transistor (TFT) capable of independently controlling the pixels by performing on / off switching operation for each pixel by an external switching control signal; An organic light emitting layer that emits light when a voltage is applied to the organic light emitting layer, and includes a plurality of pixels including first and second electrode layers disposed on both sides of the organic light emitting layer to apply the voltage to the organic light emitting layer, wherein the plurality of pixels are disposed within the internal space. An organic light emitting unit in which the first electrode layer is stacked on the TFT layer to form a matrix array, wherein the first electrode layer of each pixel is connected to a corresponding TFT; An edge portion facing the substrate while covering all of the organic light emitting portion on the substrate is sealed by a sealant to provide a sealed interior space between the substrate, the organic light emitting portion is located in the interior space, and hydrogen A sealing layer made of a material having no permeability; And a water decomposition type water removal unit disposed at a predetermined position of the enclosed internal space of the OLED element and reacting with water present in the internal space to generate hydrogen to decompose the water. An insulating layer covering the second electrode layer of the organic light emitting part to be insulated from other parts of the periphery; And one side portion and the other side portion thereof opposite to the inner space of the OLED element from the inner space to the outer space are exposed to the inner space and the outer space, respectively, and the concentration difference of hydrogen in the inner space and the outer space is different. By absorbing the hydrogen present in the inner space by the structure to include a hydrogen removal unit to be discharged to the outer space through itself.

According to another preferred configuration of the OLED device according to the invention, the OLED device comprises a substrate; A TFT layer disposed on the substrate and including at least as many pixels as a thin film transistor (TFT) capable of independently controlling the pixels by performing on / off switching operation for each pixel by an external switching control signal; An organic light emitting layer that emits light when a voltage is applied to the organic light emitting layer, and includes a plurality of pixels including first and second electrode layers disposed on both sides of the organic light emitting layer to apply the voltage to the organic light emitting layer, wherein the plurality of pixels are disposed within the internal space. An organic light emitting part in which the first electrode layer is stacked on the TFT layer to form a matrix array, and the first electrode layer of each pixel is connected to a corresponding TFT; An edge portion facing the substrate while covering all of the organic light emitting portion on the substrate is sealed by a sealant to provide a sealed inner space between the substrate, and a sealing layer in which the organic light emitting portion is located in the inner space. ; An insulating layer covering the second electrode layer of the organic light emitting part to be insulated from other parts of the periphery; And a water decomposition type water removal unit disposed at a predetermined position of the sealed inner space and reacting with water present in the inner space to generate hydrogen, and decomposing the water, in particular, the sealing layer has a hydrogen permeability. It is made using and absorbs the hydrogen present in the inner space by the difference in the concentration of hydrogen in the inner space and the outer space to pass through itself to be discharged to the outer space, but the decomposition of water by the moisture removal unit Hydrogen has the ability to discharge more than the amount of hydrogen generated.

In the above two configuration examples, the material and arrangement of the insulating layer, the main raw material of the hydrogen removal portion, the arrangement and hydrogen discharge ability, the material and arrangement of the moisture removal portion, the addition of the protective film, the material of the sealing layer, and the like described above As shown.

Hereinafter, with reference to the accompanying drawings will be described the present invention in more detail.

(1) Examples of the preferred structure of the OLED device

1 to 8 show representative structures of OLED devices according to preferred embodiments of the present invention. The illustrated OLED devices are common in terms of disposing a water removal unit for decomposing and removing water present in the device. 1 to 7, however, a structure in which a hydrogen removing unit for discharging hydrogen existing in the OLED device to the outside of the device is connected to the outside from the inside of the device (in this case, the sealing layer has a hydrogen discharge function). In the case of FIG. 8, since the sealing layer is made of a material having a hydrogen discharge function, the hydrogen inside the device is discharged to the outside through itself. The difference is that the structure does not have a hydrogen removal unit. In the OLED device of FIG. 8, the hydrogen removing unit may be additionally disposed in the form as shown in FIGS. 1 to 7 to enhance the hydrogen discharge function.

1 to 7 are different in the position and the form in which the water removal unit and the hydrogen removal unit are installed. First, according to the OLED device 100 illustrated in FIG. 1, an organic light emitting part 120 is disposed on an upper surface of the substrate 110. The hydrogen removing unit 180 and the water removing unit 130 are sequentially stacked on the bottom surface of the sealing layer 140 facing parallel to the substrate and spaced apart by a predetermined interval. The sealing layer 140 cooperates with the substrate 110 to secure the internal space of the OLED device while protecting the elements disposed therein. The organic light emitting part 120 and the moisture removing part 130 face each other and are separated by the insulating layer 150. A sealant 170 is added between the edge of the substrate 110 and the edge of the hydrogen removal unit 180 to seal the internal space between the substrate 110 and the hydrogen removal unit 180. At this time, the moisture removing unit 130 is stacked so that only a portion of the center portion of the hydrogen removing unit 180 is exposed so that a portion of the hydrogen removing unit 180 is exposed to the sealed inner space where the insulating layer 150 is located. In addition, the hydrogen removal unit 180 extends to the outside of the OLED element 100 past the sealant 170, the end portion thereof is exposed to the outside.

FIG. 9 illustrates in more detail the portion 190 indicated by the dashed-dotted line in FIG. 1, and more specifically illustrates the structure of the organic light emitting unit 120 disposed on the substrate 110. The illustrated OLED device is an active OLED device in which a thin film transistor (TFT) layer 128 is disposed on an upper surface of a substrate. The organic light emitting unit 120 is stacked on the TFT layer 128. In detail, the organic light emitting unit 120 has a structure in which the first electrode layer 122, the organic light emitting layer 124, and the second electrode layer 126 are sequentially stacked. The organic light emitting layer 124 is made of an organic material that emits light by transporting and recombining holes and electrons supplied from the two electrode layers 122 and 126. The organic substance which can be used may be a single molecule or a polymer. That is, the organic light emitting layer 124 includes an electron transport layer, a hole transport layer, and the like, and the first electrode layer 122 and the second electrode layer 126 are disposed on both sides thereof to form one pixel. The TFT layer 128 includes a plurality of TFTs in which one TFT is connected to each pixel. Each TFT performs an on / off switching operation by a switching control signal given from the outside, thereby controlling whether or not a voltage is applied between the two electrode layers 122 and 126. Therefore, the active OLED device may independently control the emission of each pixel of the organic light emitting unit 120 by controlling the on / off of the TFT of the TFT layer 128 using the switching control signal.

 Of the first electrode 122 and the second electrode 126 that apply an electric field to the organic light emitting layer 124, the electrode located on the opposite side of the light emitting direction of the organic light emitting layer 124 may be opaque, but the electrode located toward the light emitting direction is transparent. It is preferable that it is an electrode. The transparent electrode may be made of, for example, an Indium-Tin Oxide (ITO) electrode, and the opaque electrode may be made of, for example, an opaque metal. For reference, in the case of the top emission type, the light emission direction is a direction (front direction) from the substrate 110 toward the sealing layer 140, and the light emission direction of the bottom emission type is 180 degrees opposite to that of the front emission type. In addition, although the TFT 128 is provided to be in contact with the upper surface of the substrate 110, in the case of the active OLED, it is sufficient that the TFT 128 for controlling each pixel is disposed anywhere in the OLED element. It is mainly placed on the substrate.

An OLED device 200 of a different structure than the OLED device 100 of FIG. 1 is shown in FIG. 2. The OLED device 200 has a structure in which an organic light emitting unit 220 is disposed on an upper surface of the substrate 210 and the organic light emitting unit 220 and the water removing unit 230 face each other with an insulating layer 250. It is the same as the OLED element 100 of FIG. However, the moisture removing unit 230 and the hydrogen removing unit 280 are not laminated on the sealing layer 240 in two layers, but are different in that they are directly attached to the sealing layer 240 separately. That is, one side of the water removing unit 230 faces the organic light emitting unit 220 and the other side is directly attached to the sealing layer 240. In addition, the hydrogen removal unit 280 is directly attached to the sealing layer 240 spaced apart from the edge of the water removal unit 230 by a predetermined interval. The sealant 270 is added and sealed between the substrate 210 and the moisture removing unit 230. Even in this case, the hydrogen removal unit 230 has one end thereof exposed to a closed inner space of the OLED element 200 (the space in which the insulating layer 250 is disposed) and the other end thereof is the OLED element 200. It is also exposed to the outer space of). Although not necessary, a portion of the hydrogen removing unit 280 exposed to the external space of the OLED element 200 may be coated with the protective film 285-1. In addition, a portion of the hydrogen removing unit 280 exposed to the sealed inner space of the OLED element 200 may also be applied to the protective film 285-2. These protective films 285-1 and 285-2 function to prevent damage or deformation of the hydrogen removal unit. In other words, The protective film 285-1 on the outer space side of the OLED element 200 functions to prevent the hydrogen removal unit from being denatured or damaged by an external environment, and the protective film 285 on the inner space side of the OLED element 200. -2) prevents hydrogen damage from mutual damage by touching the circuit part inside.

3 shows an OLED device 300 of yet another structure. The organic light emitting unit 320 is disposed on the upper surface of the substrate 310, and the water removing unit 330 is directly attached to the sealing layer 340, and the organic light emitting unit 320 and the water removing unit 330 are formed of an insulating layer ( The arrangement facing each other with a predetermined interval spaced between 350 is the same as the OLED structure 200 of FIG. 2. In other respects, the hydrogen removing unit 380 is directly attached to the substrate 310 rather than attached to the sealing layer 340. Even in this case, the hydrogen removing unit 380 is disposed in a form extending from the sealed inner space of the OLED element 300 to the outer space. The sealant 370 is naturally added between the hydrogen removing unit 380 and the sealing layer 340 to seal the space in which the organic light emitting unit 320 is disposed.

The hydrogen removal portion may be added in the form of penetrating the sealant without directly attaching to the substrate or the sealing layer. The structure employing this method is the OLED element 400 shown in FIG. This OLED element 400 has a structure slightly modified from the OLED element 300 of FIG. That is, the organic light emitting part 420 is disposed on the upper surface of the substrate 410, the moisture removing part 430 is attached to the sealing layer 440, and the organic light emitting part 420 and the moisture removing part 430 are insulated from each other. The disposition structure facing each other while being spaced apart from the layer 450 is the same as the OLED device 300 of FIG. 3. However, the hydrogen removal unit 480 is not directly attached to the substrate 410 or the sealing layer 440, but sealants 480 are added between the substrate 410 and the sealing layer 440 to seal the gap therebetween. The hydrogen removing unit 480 extends from the inner space of the sealed OLED device 400 to the outer space while penetrating through the sealant 480.

The OLED device 500 shown in FIG. 5 is a slight modification of the structure of the OLED device 200 shown in FIG. That is, the difference is that the moisture removing unit 530 is not disposed to face the organic light emitting unit 520 and is attached to the bottom surface of the sealing layer 540 slightly off the edge of the organic light emitting unit 520. Therefore, since the moisture removing unit 530 is no longer positioned to block the organic light emitting unit 520, the organic light emitting unit 520 directly faces the sealing layer 540. Of course, the insulating layer 550 is interposed between the organic light emitting unit 520 and the sealing layer 540. The rest of the structure is the same as the OLED device 200 of FIG. That is, the organic light emitting unit 520 is disposed on the upper surface of the substrate 510, and the hydrogen removing unit (ie) is further separated from the outside at the point where the water removing unit 530 of the lower surface of the sealing layer 540 is disposed. 580 is attached. In addition, a sealant 570 is added between the hydrogen removing unit 580 and the substrate 510 to seal an inner space in which the organic light emitting unit 520 is disposed. Furthermore, one or both ends of the hydrogen removal portion 580 exposed to the internal space and the external space of the OLED element 500 are coated with a protective film 585.

6 shows the structure of another OLED device 600. The structure of the OLED device 600 combines the arrangement of the water removal unit 630 of the OLED device 500 of FIG. 5 and the arrangement of the hydrogen removal unit 330 of the OLED device 300 of FIG. 3. to be. That is, the organic light emitting portion 620 is disposed at the center of the upper surface of the substrate 610, and the organic light emitting portion 620 is disposed on the lower surface of the sealing layer 640 facing the substrate 610 at a predetermined distance. The moisture removing unit 630 is attached to a region slightly beyond the edge portion thereof so as not to be covered. In addition, the hydrogen removing unit 680 is attached to the edge of the upper surface of the substrate 610 while being slightly spaced apart from the organic light emitting unit 620. The sealant 670 is added between the hydrogen removing unit 680 and the sealing layer 640 to seal the region of the organic light emitting unit 620.

The OLED device 700 illustrated in FIG. 7 has a structure slightly modified from the structure of the OLED device 600 of FIG. 6. The organic light emitting unit 720 is disposed on the upper surface of the substrate 710, and the moisture removing unit 730 is attached to the lower surface of the sealing layer 740 so as not to cover the organic light emitting unit 720. . The difference is that the sealant 770 is added between the substrate 710 and the sealing layer 740 to seal the space in which the organic light emitting part 720 is disposed, and the hydrogen removing part 780 removes the sealant 770. It is arranged to extend from the sealed inner space of the OLED element 700 to the outer space while penetrating.

In the OLED devices 100, 200,... 700 illustrated in FIGS. 1 to 7, the hydrogen removal units 180, 280,..., 780 are formed of the OLED devices 100, 200,... Located at all or a portion of the edge of 700). In particular, the hydrogen removal parts 180, 280,..., 780 extend from the enclosed inner space of the OLED elements 100, 200,..., 700 to the outer space, and both ends thereof are connected to the OLED element 100. , 200, ..., 700, respectively, in the enclosed interior and exterior spaces. Hydrogen removal unit 180, 280, ..., 780 serves as a passage for discharging hydrogen inside the device to the outside. That is, hydrogen is generated while the moisture removal parts 130, 230, ..., 730 decompose moisture inside the device, and when such hydrogen generation continues, the concentration of hydrogen is much higher inside the device than outside the device. In such a state, the hydrogen present inside the device is absorbed through the portion exposed to the inside of the device of the hydrogen removal unit 180, 280, ..., 780 due to the difference in the hydrogen concentration with the outside of the device hydrogen removal unit 180 , 280, ..., 780 are discharged out of the device through portions exposed outside the device.

Meanwhile, as mentioned above, in the OLED device 800 of FIG. 8, the organic light emitting unit 820 is disposed on the substrate 810 in comparison with the OLED devices 100, 200,... 700 of FIGS. 1 to 7. The encapsulation layer 840 covers the encapsulation layer 840 and is sealed with a sealant 870 along the facing edges of the substrate 810 and the encapsulation layer 840 so that the organic light emitting portion 820 is positioned in a closed interior space. Although the same as for the insulating layer 850 is added to the upper electrode layer of the light emitting unit 820, there is a difference in that the hydrogen removing unit is not provided separately. The sealing layer 840 is responsible for discharging hydrogen inside the OLED device 800 to the outside. The main function of the sealing layer 840 is to cooperate with the substrate 810 to protect the organic light emitting layer disposed therein while maintaining the skeleton of the device. However, if the sealing layer 840 is made of a material having good hydrogen permeability while being able to perform such a function, the sealing layer 840 may also be responsible for discharging hydrogen existing in the device to the outside in addition to the protective cap function. It becomes possible.

(2) moisture removal

The performance of the water removal unit used in the OLED device is determined by the removal rate, the removal amount and the equilibrium concentration in the equilibrium state. The faster the removal rate and the lower the equilibrium concentration, the better. The water removal unit 130, 230, ..., 830 is preferably made of a water-decomposable dehumidifying substance that decomposes the water while generating hydrogen by reacting with the water. Representative examples of water-decomposable dehumidifying materials include metals, metal hydrides, alloys or mixtures thereof, and the like. In the case of metals, 'metals having a higher ionization tendency than hydrogen' are preferable. Examples include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), and barium ( Ba), aluminum (Al), zinc (Zn), iron (Fe), nickel (Ni), and the like. In view of practicality, it is more preferable to use 'a metal having a higher ionization tendency than zinc' as a raw material of the water removal unit.

Representative examples of the metal hydride that is the main raw material of the water removal unit 130, 230, ..., 830 are alkali metal hydride, alkaline earth metal hydride, boron (Boron) or alkali metal hydride including boron, boron Or at least one selected from the group consisting of (Boron) or alkaline earth metal hydrides containing aluminum, and mixtures thereof. Examples of such metal hydrides include sodium hydride (NaH), potassium hydride (KH), calcium hydride (CaH ₂ ), strontium hydride (SrH ₂ ), aluminum hydride (AlH ₃ ), and lithium borohydride. Hydride (LiBH ₄ ), lithium aluminum hydride (LiAlH ₄ ), sodium aluminum hydride (NaAlH ₄ ), potassium aluminum hydride (KAlH ₄ ), calcium aluminum hydride (CaAl ₂ H ₈ ), and the like.

In the case of a dehumidifying substance using a metal hydride, water is removed by the following reaction scheme. Hydrogen gas is produced during the reaction to remove water. The hydrogen gas is discharged to the outside of the OLED element by the hydrogen removing unit.

MH _n + nH ₂ O → M (OH) _n + nH ₂ .... (1)

On the other hand, the water removal unit (130, 230, ..., 830) is preferably made by mixing a polymer with a metal hydride or metal in powder form in order to maintain a specific shape. If the polymer mixture is used as a raw material, the moisture removal part can be made into a thin film. The film-like moisture removal unit is easy to install and thin, which relieves the burden of increasing the thickness of the OLED device. For reference, although the polymer is usually melted and mixed with a metal or the like, it is also possible to press and shape the fibrous polymer after mixing.

The size of the water removal unit 130, 230, ..., 830 may be determined in consideration of the moisture transmittance of the sealant (170, 270, ..., 870) and the initial amount of water flowing in the sealing process of the device. In order to effectively remove moisture, it is advantageous that the moisture removing portion is widely disposed in the internal space of the OLED device. The arrangement of the water removal unit shown in FIGS. 1 to 4 and 8 has a larger surface area of the water removal unit than the arrangement shown in FIGS. 5 to 7. 1 to 4 and 8, when the OLED device is a front light emitting device in a position where the water removing unit faces the organic light emitting unit, the water removing unit is placed on the path of output light. In that case, the transparency of the water removal unit needs to be high. 5 to 7, the transparency of the water removal unit is not a problem since the water removal unit is diverted from the path of the output light of the organic light emitting unit, whether the OLED device is a top emission type or a bottom emission type.

Moisture-removing materials are dispersed or dissolved in polymer binders in a particle size that is sufficiently smaller than the wavelength of visible light, in the Rayleigh scattering range, i.e., less than 1 micron, more preferably less than about 50 nanometers. If so, excellent transparency is obtained. That is, when a metal or a metal hydride is crushed to a size of 50 nanometers or less, and the powder is suitably blended with a polymer binder, a transparent effect is produced by Rayleigh scattering phenomenon. In particular, metal hydride is easier to pulverize than metal, so it is easy to pulverize into nanoparticles, and metal hydride (Lithium borohydride, Lithium aluminum hydride, etc.) has a property of being dissolved in an appropriate polymer, which is more advantageous for making transparent thin films. However, as metal crushing technology is developing, it is possible to make transparent thin films using a metal such as aluminum. An opaque thin film moisture removal unit can also be used. In this case, the moisture removing unit may be disposed at a position which does not obstruct the traveling path of the output light of the organic light emitting unit. For example, as shown in FIGS. 5 to 7, a method of disposing the moisture remover in a position deviated outside the edge of the organic light emitting unit without facing the organic light emitting unit may be employed. Then, even if the OLED device is a front emission type, the moisture remover does not interfere with the progress of light generated in the organic light emitting unit.

In addition, even when the refractive index of the polymer mixed with the moisture removing material is similar, good transparency is obtained. Thermoplastic resins or reactive curable resins may be used as the polymer admixture. Polymers such as thermoplastic resins or reactive curable resins preferably have a high MVTR because they have low light transmittance when they are made porous to facilitate mass transfer. In addition, it is desirable to minimize turbidity in order to minimize the decrease in transmittance due to light scattering.

The moisture transmittance (MVTR) may vary depending on the processing method of the transparent dehumidifying thin film 30, but is a physical property depending on the chemical structure of the polymer. Therefore, MVTR is a property that can be used as a selection criteria of the polymer used as a mixed material with the dehumidifying material in the present invention. As a material that can be used as the polymer blend, a thermoplastic resin or a reactive curable resin having a moisture permeability (MVTR) of 40 ° C and 75% RH (relative humidity) of 10 g · mil / m ² · day or more is preferable. Representative examples of thermoplastic resins satisfying these characteristics include polyolefins, unsaturated polyolefins, substituted polyolefins, substituted unsaturated polyolefins and random copolymers or block copolymers of monomers thereof. The polyolefin may be selected from polyethylene, polypropylene, polybutene, poly (4-methylpentene) or mixtures thereof. The unsaturated polyolefin may be selected from polybutadiene, polyisoprene or mixtures thereof. Substituted polyolefins can be selected from polystyrene, polyvinylchloride, polyvinylfluoride, polyvinylidenechloride, polyvinylidenefluoride or mixtures thereof. Substituted unsaturated polyolefins include polychloroprene. Still other examples of thermoplastic resins include polyphenylene oxide, polyphenylene sulfide, polyethersulfone or mixtures thereof. In addition, examples of the reaction curable resin that satisfies the above water-permeability characteristics include a polymerizable resin. The polymerizable resin may be one in which the polymerization reaction is initiated by radiant energy or one may be initiated by heat. The water removal unit may be attached using a pressure sensitive adhesive, a pressure sensitive adhesive, or an adhesive film, or may be attached by a heat compression method utilizing the self adhesive force of the polymer without a separate adhesive.

(3) Hydrogen permeable sealing layer and hydrogen removal part

Hydrogen gas may be present in the internal space of the OLED devices 100, 200,..., 800. Hydrogen gas is rarely introduced into the device in the external space of the OLED device and occurs only inside the device. For example, hydrogen is incidentally generated when the water decomposition type water removal unit 130, 230, ..., 830 reacts with water in the device internal space to remove water. In addition, hydrogen may be generated by electrochemical reactions of organic materials and electrodes in OLED devices. For any reason, the presence of hydrogen in the interior space of the OLED device causes a problem that the pressure inside the OLED device rises or the lifetime of the pixel decreases. Therefore, it is necessary to prevent hydrogen from accumulating in the internal space of the OLED element.

1) Hydrogen Permeable Sealing Layer

The sealing layer 840 of the OLED device 800 of FIG. 8 has a hydrogen removal function. The hydrogen permeable sealing layer 840 is made of a material having a good hydrogen transmittance such as a metal or a polymer. For example, it can be made into a laminated structure in which a metal or a metal and a polymer are laminated in two or more layers. Glass is not used as a material for the sealing layer 840 of FIG. 8 because it has no permeability to hydrogen (hydrogen transmittance).

Hydrogen permeation characteristics required for the sealing layer 840 of FIG. 8 are as follows. In the case of an OLED device, the moisture transmittance of the sealant 870 which is commonly used is about 0.1 [mole · mm / m ² · day] in an environment where moisture content outside the OLED is about 7%. For example, an OLED device measuring 30 cm x 20 cm is typically around 100 cm, 10 microns, and 1 mm in thickness, width, and width of the sealant portion, so that the exposed area of such sealant to the outside atmosphere is 100 cm x 10 micron = 1x10 ^-5 It becomes about m <^2> , and the permeation path of moisture becomes 1 mm which is the width of a sealant. In that case, the permeation rate of water passing through the sealant is as follows.

Moisture penetration rate = (moisture penetration rate x moisture penetration area) / moisture penetration path

= 0.1 [mole · mm / m 2 · day] x 1x10 -5 m 2 / 1mm

= 1x10 ^-6 [mole / day] .... (2)

The water introduced into the OLED device 800 reacts with the water removing unit 830 to generate hydrogen. Assuming that the water removal unit 830 is formed of a metal hydride, the amount of hydrogen generated in the internal space of the device 800 by the reaction between the water removal unit 830 and water to be discharged to the outside of the device is 1x10 ^-6 [mole / day]. An exemplary reaction scheme is as follows.

CaH ₂ + H ₂ O-> Ca (OH) ₂ + H ₂ .... (3)

The number of moles of hydrogen gas generated is the number of moles such as moisture. When water removal unit 830 is implemented as a metal if the 1/2 0.5x10 ^-6 [mole / day] compared to the amount of hydrogen-metal hydride to be discharged is generated by a reaction with moisture. An exemplary scheme in this regard is as follows.

Ca + H ₂ O-> Ca (OH) ₂ + 1 / 2H ₂ .... (4)

In this case, the number of moles of hydrogen gas generated is 1/2 of the number of moles of water. Therefore, based on the metal hydride having a large hydrogen generation rate, the hydrogen permeable sealing layer 840 functioning as a hydrogen removing unit should be discharged at a hydrogen discharge rate of 1x10 ^-6 [mole / day] or more of the OLED device 800. Accumulation of hydrogen does not occur in the internal space.

If the pressure in the internal space of a typical OLED element is 1 atm (1013 hPa) and the allowable concentration of hydrogen is about 1%, then the hydrogen partial pressure at this time is 1013 Pa. The area of the hydrogen permeable sealing layer 840 is 30 cm × 20 cm = 6 × 10 ⁻² m ² . That is, the hydrogen permeation area (the cross-sectional area of the sealing layer 840 through which hydrogen flows) is 6 × 10 ⁻² m ² , and the hydrogen permeation path is equal to the thickness of the hydrogen permeable sealing layer 840.

(A) The hydrogen permeability of the metal required when the hydrogen permeable sealing layer 840 is composed of only a metal material having a thickness of 0.5 mm may be calculated as follows.

Hydrogen permeability = (Hydrogen permeation rate x Hydrogen permeation path) / (Hydrogen permeation area x Hydrogen partial pressure ^0.5 ) = (1x10 ^-6 [mole / day] x 0.5 [mm]) / (6x10 ^-2 m ² x (1013 Pa) ^0.5 }

^{= 2.62x10 -7 [mole mm / m} 2 · day · Pa 0 .5]

^{= 3.03x10 -12 [mole · mm /} m 2 · sec · Pa 0 .5] .... (5)

Changing the units in the above calculation results, the required hydrogen permeability is 3.03x10 ^-15 [mole · m / m ² · sec · Pa ^0.5 ]. That is, in this case, the hydrogen transmittance of the hydrogen permeable sealing layer 840 should be 3.03 × 10 ⁻¹⁵ [mole · m / m ² · sec · Pa ^0.5 ] or more. When the above values are more relaxed in consideration of the deviation, the hydrogen permeability of the hydrogen permeable sealing layer 840 is preferably ^1.0 × 10 ⁻¹⁵ [mole · m / m ² · sec · Pa ^0.5 ] or more. Virtually all transition metals or their alloys meet these conditions. At least one selected from the group consisting of Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium) may be used as an example of a representative metal that can be used as the main raw material of the hydrogen permeable sealing layer 840. Eggplants.

(B) The hydrogen permeability of the polymer and metal required to form a hydrogen permeable sealing layer 840 on two layers by laminating a polymer layer 0.5 mm thick and a metal layer 1 micron thick is calculated as follows. Can be.

(B-1) In the case of the polymer material used for the polymer layer, the required hydrogen permeability can be calculated as follows.

Hydrogen permeability = (hydrogen permeation rate x hydrogen permeation path) / (hydrogen permeation area x hydrogen partial pressure) = (1x10 ^-6 [molemm / day] x 0.5 [mm]) / (6x10 ^-2 m ² x 1013Pa)

^{= 8.23x10 -9 [mole · mm /} m 2 · day · Pa]

^{= 9.51x10 -14 [mole · mm /} m 2 · sec · Pa] .... (5)

In the above calculation, the unit is changed to 9.51x10 ^-17 [mole · m / m ² · sec · Pa]. That is, in this case, the hydrogen transmittance of the polymer should be 9.51x10 ^-17 [mole m / m ² · sec · Pa] or more. In fact, almost all polymers except for some of the water-soluble polymers have this level of transmission.

(B-2) In the case of a metal material used for the metal layer, the hydrogen permeability of the metal required can be calculated as follows. When the metal layer is thin, the hydrogen permeability is similar to that of the polymer,

Hydrogen permeability = (hydrogen permeation rate x hydrogen permeation path) / (hydrogen permeation area x hydrogen partial pressure) = (1x10 ^-6 [mole / day] x 1x10 ^-3 [mm]) / {6x10 ^-2 m ² x 1013Pa}

^{= 1.65x10 -11 [mole mm / m} 2 · day · Pa]

^{= 1.90x10 -16 [mole · mm /} m 2 · sec · Pa] .... (6)

Changing the units in the above calculation results, the required hydrogen permeability is 1.90x10 ^-19 [mole · m / m ² · sec · Pa ^0.5 ]. That is, in this case, the hydrogen transmittance of the metal layer should be at least 1.90x10 ^-19 [mole m / m ² · sec · Pa ^0.5 ]. In consideration of the deviation assuming allow more margin for the above value, the hydrogen permeability is preferably not less than ^{1.0x10 -19 [mole · m / m} 2 · sec · Pa 0 .5]. Virtually all transition metals or their alloys meet these conditions.

In order to prevent accumulation of hydrogen in the OLED device 800, the hydrogen discharge capability of the hydrogen-permeable sealing layer 840 needs to be greater than or equal to the amount of hydrogen generated due to the decomposition of water by the water removal unit. As noted above, almost all transition metals, their alloys, and almost all polymers, except for some of the water-soluble polymers, meet these hydrogen-releasing capacities.

2) Hydrogen removal part

When the size of the OLED element is increased, the sealing layers 140, 240,..., 740 are advantageously made of glass rather than made of metal or polymer. The OLED devices 100, 200, ..., 700 shown in FIGS. 1 to 7 are formed inside the device when the sealing layers 140, 240, ..., 740 are made of a material having almost no hydrogen permeability such as glass. The hydrogen removal unit 180, 280, ..., 780 is responsible for discharging the existing hydrogen to the outside. That is, the hydrogen removal unit 180, 280, ..., 780 is connected from the internal space of the OLED device (100, 200, ..., 700) to the external space of the device, while one side and the other side opposite thereto It is arranged to be exposed to the inner space and the outer space, respectively. The hydrogen removal unit 180, 280, ..., 780 absorbs the hydrogen present in the internal space of the device by the difference in the concentration of hydrogen in the internal space and the external space, and discharges it out of the device through itself. Play a role. In this case, in order not to accumulate hydrogen in the device, the hydrogen discharge capability of the hydrogen removal units 180, 280, ..., 780 needs to be greater than the amount of hydrogen generated by the decomposition of water by the water removal unit. There is. To this end, it is necessary to comprehensively consider the surface area exposed to the internal and external spaces of the hydrogen removing unit and the hydrogen permeability of the material used as the hydrogen removing unit.

One method of placing the hydrogen removal portions 180, 280, ..., 780 in the corresponding positions shown in Figs. 1 to 7 is to form the hydrogen removal portion in the form of a thin film and to add an adhesive to at least one side thereof. It is a method of attaching directly to the corresponding position of the OLED device. To this end, the metal or alloy of the metal, which is a raw material of the hydrogen removal unit, may be processed into a powder form, and then mixed with a polymer binder, and then the hydrogen removal unit in the form of a thin film may be used using the mixture. In this case, the content of the polymer is preferably 90 vol% or less. In excess of 90% of the polymer is inefficient. The polymer used to make the moisture removal part can be used in the production of the hydrogen removal part. As another arrangement method of the hydrogen removal units 180, 280, ..., 780, a method of forming a thin hydrogen removal layer by sputtering the metal or its alloy at a corresponding position of the OLED element. In addition, a method of solidifying or reducing a metal or an alloy thereof or a compound thereof after dissolving it in a liquid substance and then applying it to a corresponding position of the OLED device, or after dissolving a compound of the metal or an alloy thereof in a liquid substance, A method of plating or depositing at a position, and a method of forming a powder of the metal or an alloy thereof into a powder and then mixing the polymer with a polymer to apply it to a corresponding position of the OLED.

The hydrogen removal parts 180, 280, ..., 780 are preferably made of metals having high permeability of hydrogen and their alloys as main raw materials. Examples of preferred metals that can be used as the main raw materials for the hydrogen removal part include at least one selected from the group consisting of Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium). Can be. Metals or alloys of metals suitable for use as a hydrogen removal unit preferably have a hydrogen permeability greater than 10 ⁻¹¹ [mole / m sec Pa ^0.5 ] at room temperature and more than 10 ⁻¹⁰ [mole / m sec Pa ^0.5 ] at room temperature. It is more preferable to use a metal having a large hydrogen transmittance or an alloy thereof.

The basis for calculating the magnitude of the hydrogen transmittance is as follows. In the case of OLED devices, the commonly used sealant has a water transmittance of about 0.1 [mole · mm / m ² · day] in an environment where moisture content outside the OLED is about 7%. Assuming that the water-removing part is composed of a metal hydride, the amount of hydrogen generated in the internal space of the device due to the reaction between the water-removing part and the moisture to be discharged to the outside is 0.1 [mole · mm / m ² · day] . An exemplary reaction scheme is as follows.

CaH ₂ + H ₂ O-> Ca (OH) ₂ + H ₂ .... (7)

The number of moles of hydrogen gas generated is the number of moles such as moisture. If the water removal part is implemented as a metal, the amount of hydrogen generated and discharged by the reaction with water is 0.05 [mole · mm / m ² · day], which is 1/2 of the metal hydride. An exemplary scheme in this regard is as follows.

Ca + H ₂ O-> Ca (OH) ₂ + 1 / 2H ₂ .... (8)

In this case, the number of moles of hydrogen gas generated is 1/2 of the number of moles of water. Therefore, based on the metal hydride having a large hydrogen generation rate, the hydrogen removal unit should discharge at a hydrogen discharge rate of 0.1 [mole · mm / m ² · day] or more, so that no accumulation of hydrogen occurs in the internal space of the OLED device. For example, if the allowable concentration of hydrogen inside an OLED device is 1% (generally known as 1% or less), and the total pressure in the space inside the OLED device is 1013hPa, the partial pressure of hydrogen in the inside space of the OLED device is 1013hPa x 1 % = 1013 Pa. In this case, let's calculate the hydrogen permeability of the required hydrogen removal part. The hydrogen transmittance is as follows.

Hydrogen Permeation Rate = Hydrogen Emission Rate / (Hydrogen Partial Pressure) ^0.5 .... (9)

According to the above formula bar, calculated by substituting the amount of the hydrogen release rate and the hydrogen partial pressure of 1013Pa 1% hydrogen permeability it is required ^{3.64x10 -8 [mole · mm / m} 2 · sec · Pa 0 .5] or more. When replacing a ^{unit, 3.64x10 - 11 [mole · m} / m 2 · sec · Pa 0.5] or higher is required.

For example, a 1.2-inch OLED device typically has a circumference and a thickness of about 10 cm and 10 microns, respectively, so that the sealant's exposure to the outside atmosphere is about 10 cm x 10 micron = 1x10 ^-6 m ² . In that case, the permeation rate of water passing through the sealant is 0.1 [molemm / m ² · day] x 1x10 ^-6 m ² = 1x10 ^-7 [molemm / day], and the minimum permeation rate of hydrogen to be discharged is the same. Since it is a confiscation, it is also 1x10 ^-7 [molemm / day]. In addition, the highest allowable partial pressure of hydrogen in the internal space of the OLED device is 1013 Pa as above. If the hydrogen removal unit is disposed so that the exposed area of the hydrogen removal unit to the external atmosphere (external space) of the OLED element is 1/10 of the exposed area of the sealant (to reduce the exposure area of the hydrogen removal unit, that is, if arranged in a one-tenth to reduce the cross-sectional area), the area of the external air exposed to the hydrogen removing surface (cross-sectional area of the metal plate is a hydrogen flow) is the ^{1x10 -6 m 2/10 = 1x10} -7 m 2. Since 'hydrogen emission rate = hydrogen permeation rate / exposure area', then the required hydrogen transmission rate of the hydrogen removal unit can be calculated as follows.

Hydrogen Permeability = Hydrogen Permeation / (Exposure Area x Hydrogen Partial Pressure ^0.5 )

^{= 1x10 -7 [mole · mm /} day] / (1x10 -7 m 2 x 1013Pa 0 .5)

^{= 3.14x10 -2 [mole · mm /} m 2 · day · Pa 0 .5]

^{= 3.64x10 -7 [mole · mm /} m 2 · sec · Pa 0 .5] .... (10)

In the above calculation, the unit of hydrogen is required 3.64x10 ^-10 [mole · m / m ² · sec · Pa ^0.5 ]. That is, in this case, the hydrogen permeability of the hydrogen removal unit should be at least 3.64 × ^{10 −10} [mole · m / m ² · sec · Pa ^0.5 ]. The above has been calculated by taking an example where the exposed area to the outside atmosphere of the hydrogen discharge portion is small as 1/10 of the exposed area of the sealant. If the exposed area of the hydrogen outlet is the same as the sealant (since the cross-sectional area of the hydrogen-removing part is larger than the sealant's cross-sectional area, it is not desirable in the structure of the OLED device), the required hydrogen transmittance may be 1/10 smaller than the previous value Since the same emission effect will be obtained, the minimum discharge rate (hydrogen permeability) of the hydrogen removal unit at this time is required to be 3.64x10 ^-11 [mole m / m ² · sec · Pa ^0.5 ] or more. In consideration of the deviation assuming allow more margin for the above value, the hydrogen permeability is preferably not less than ^{1.0x10 -11 [mole · m / m} 2 · sec · Pa 0 .5].

3) Combination of hydrogen permeable sealing layer and hydrogen removal unit

If the hydrogen discharge function (to be described later) required only by the sealing layer 840 can be sufficiently satisfied, it is not necessary to install a hydrogen removal unit as shown in Figs. 1 to 7, but otherwise, hydrogen discharge capacity for enhancing the hydrogen discharge capacity. In addition to the sealing layer 840 having a hydrogen removal unit (180, 280, ..., 780) as shown in Figures 1 to 7 may be further arranged, that is, the hydrogen permeable sealing layer 840 When the hydrogen removal unit 180, 280, ..., 780 having the hydrogen discharge function is adopted at the same time, the hydrogen inside the OLED element can be discharged to the outside through both the hydrogen removal unit and the sealing layer.

(4) substrates, insulating layers, etc.

In arranging the water removal unit 130, 230, ..., 830 and the hydrogen removal unit 180, 280, ..., 880, respectively, they are disposed according to a separate process without mixing them. It is desirable to.

Glass or plastic may be used as the material of the substrate 110. Of course, glass or plastic may be flexible. When the OLED is a top emission type, the sealing layer 140 needs to be made of a transparent material. In the case of a bottom emission type, the substrate 110 should be made of a transparent material.

The plurality of electrodes of the second electrode layer 126 of the organic light emitting units 120, 220,..., 820 are insulated from each other. In this state, if the moisture removing parts 130, 230, ..., 830 or the sealing layers 140, 240, ..., 840 directly contact the second electrode layer 126, for example, Moisture or other insulating interfering material may interfere with the insulation between the electrodes of the second electrode layer 126, and if severe, may cause a short circuit between the electrodes. The insulating layers 150, 250,..., 850 serve to prevent such a problem, that is, a short circuit between the electrodes of the second electrode layer 126. The material used as the insulating layer is preferably very high electrical resistance. In addition, in the case of the front light emitting OLED device, since the insulating layers 150, 250, ..., 850 are present on the light emission path, it is preferable that the light transmittance is excellent. The material of the insulating layers 150, 250, ..., 850 may be a material in any state of a solid, liquid, or gas. In the case of gas, argon gas or nitrogen gas, in case of liquid, silicon oil, and in case of solid, polymer or glass material can be used as an insulating material. Specifically, if necessary, the entire internal space of the OLED device may be filled with an inert gas (which means a case in which a space filled with an inert gas such as nitrogen or argon) is filled. In addition, the top surfaces of the organic light emitting parts 120, 220,..., 820 may be insulated in a form of covering with a liquid film or a solid thin film of an insulating material. In addition, when the upper surface of the organic light emitting unit 120, 220, ..., 820 is covered with a liquid film or a solid thin film of the insulating material, the empty space on the upper portion of the insulating material may be filled with an insulating gas or may be left as it is. have. As a result, the insulating layers 150, 250,..., 850 may be formed of any one of a gas layer, a liquid layer, a solid layer, or a combination of these, or a blank space added thereto. have.

(5) Applicable object

The present invention can be widely applied to an active matrix (AM) OLED having a thin film transistor (TFT) capable of independently controlling each pixel. Furthermore, two types of active OLED devices, a front light emitting type (output light of the organic light emitting part is emitted toward the sealing layer) and a back light emitting type (output light of the organic light emitting part is emitted toward the substrate) can be used. The present invention can also be applied to the front emission type in which light is to be emitted (emitted) to the sealing layers 140, 240, ..., 840 in which the moisture removal unit is to be disposed, as mentioned above, in the form of a transparent film. This is because it is possible to manufacture the light emitting device or to position the water removing unit at a position deviating from the traveling path of the output light.

It is common sense that AM OLEDs should be manufactured in the top emission type due to the opaque TFT, but in practice, it is expected that many AM OLEDs will be manufactured in the bottom emission type. The reason is that the rear light emitting type is easy to manufacture, and the problem that the light emitting area ratio (opening ratio) is reduced due to the opaque TFT can be solved for the following reasons. That is, firstly, the shortcoming of the aperture ratio decreases due to the increase in luminous efficiency can be solved considerably. Second, the TFT, which causes the aperture ratio decrease, can be manufactured transparently. Third, the mobility of the TFT increases, It is possible to reduce the area (the cause of the decrease in the opening ratio) that obstructs the light path by miniaturizing the area. In the case of the bottom emission type, the transparency of the water removing unit is not a problem at all.

(6) Example and Comparative Example

Next, examples and comparative examples related to manufacturing an OLED device according to the present invention will be described.

1) Comparative Example 1

After the organic light emitting part was disposed on the glass substrate, ten OLED device samples were manufactured by encapsulation by adding a sealant to a sealing layer without adding a moisture remover and a hydrogen remover to an internal space of the device. After leaving these OLED devices at a temperature of 60 ° C. and a relative humidity of 80% RH for 240 hours, the pixels were observed under a microscope to measure the degree of pixel reduction, and the gas inside the device was collected to measure hydrogen concentration. According to the measurement results, at least 10 micron or more pixel reduction phenomenon was observed at the edge of each pixel. In addition, the concentration of hydrogen in the interior space of the OLED device was observed to be (maximum) 0.1% or less.

2) Comparative Example 2

Thin film (tape) type moisture & hydrogen-getter (RTM) commercially available on the inner surface of the glass sealing layer of a 1.2 "OLED device (Q-Getter SF by RF Inc .: 200 microns thick x 14 mm wide x long) 8 mm) were attached to the inner surface of the encapsulation layer, which is isolated from the organic light emitting part and the gas insulation layer, to prepare 10 OLED device samples encapsulated with a temperature of 60 ° C. and a relative humidity of 80% RH. After standing for 240 hours at, the pixel was observed under a microscope to measure the degree of pixel reduction, and the concentration of hydrogen was measured by collecting the gas inside the device. A shrinkage phenomenon was observed, and the concentration of hydrogen in the space inside the OLED device was (up to) 0.6% or less.

3) Example 1

Manufactured in the form of a tape 50 microns thick x 14 mm wide x 8 mm long using a water-removing part (a mixture of sodium hydride and polymer in a ratio of 40 wt% to 60 wt%) on the inner surface of a 1.2 "OLED glass sealing layer. 10 OLED device samples were prepared by attaching only the organic light emitting part and the gas insulation layer to the inner surface of the sealing layer, which are separated from each other, with a temperature of 60 ° C. and a relative humidity of 80%. After standing at RH for 240 hours, the pixel was observed under a microscope to measure the degree of pixel reduction, and the concentration of hydrogen was measured by collecting the gas inside the device. Pixel shrinkage was observed, and the concentration of hydrogen in the OLED device was measured at least 37% and at an average of 54%. Minutes were swollen risen, that of the four samples went badly swollen.

4) Example 2

Manufactured in the form of a tape 50 microns thick x 14 mm wide x 8 mm long using a water-removing part (a mixture of sodium hydride and polymer in a ratio of 40 wt% to 60 wt%) on the inner surface of a 1.2 "OLED glass sealing layer. Attached to the inner surface of the sealing layer, which is isolated from the organic light emitting part and the gas insulating layer, and the hydrogen removing part (palladium) is plated with a thickness of 3 microns at a thickness of 2 mm on the edge of the sealing layer. Afterwards, 10 samples of OLED devices sealed with sealants were prepared, and these OLED devices were allowed to stand at a temperature of 60 ° C. and a relative humidity of 80% RH for 240 hours, and then the pixels were observed under a microscope to measure the degree of pixel reduction. The concentration of hydrogen was measured by collecting the gas inside, and according to the measurement result, an average of 2.3 micron pixel reduction phenomenon was observed at the edge of each pixel. Degrees (maximum) was determined to be less than 0.7%.

In the above Comparative Examples and Examples, it can be seen that the function of the water removal unit has an important influence on the prevention of pixel reduction of the OLED element. In addition, when there is no means (hydrogen removal unit) for discharging (removing) hydrogen generated during the water removal reaction inside the device by the water removal unit (hydrogen removal unit), a very large amount of hydrogen may damage the OLED device. Although it remains in the internal space of the OLED device, it can be seen that the problem caused by the residual hydrogen is solved by disposing the hydrogen removal unit according to the present invention in the OLED device. In view of the above evaluation results, the simultaneous placement of the water removal unit and the hydrogen removal unit in the OLED device minimizes the pixel reduction of the device and at the same time lowers the pressure of the device, thereby obtaining good results in terms of device performance and lifespan. It can be seen that.

The OLED device according to the present invention can remove moisture present therein and effectively discharge hydrogen generated in the process of removing the moisture or hydrogen originally present to the outside. Therefore, almost no moisture or hydrogen is present in the internal space of the OLED device, which may make a positive contribution to the luminous efficiency and lifetime of the device.

In addition, since the hydrogen removal unit does not absorb and store hydrogen and discharges it to the outside, the volume of the hydrogen removal unit required is very much reduced. Therefore, the hydrogen removal portion can be arranged thinly (less than 50 microns, preferably less than 30 microns). As a result, the overall thickness of the OLED device can be made thin.

In the present invention, since the hydrogen removal unit is separated separately, the moisture removal unit can be configured very thin, thereby reducing the thickness of the OLED. Conventionally, the moisture removal part has a thickness of 150 microns or more, but according to a method of separating and arranging the hydrogen removal part, the moisture removal part may have a thickness of 100 microns or less, preferably 30 microns or less, thereby reducing the thickness of the OLED device.

Claims (35)

A sealing layer (cap) is positioned on the substrate, and the sealing edges of the substrate and the sealing layer facing each other are sealed to provide a sealed inner space therebetween, and the organic light emitting layer and two electrode layers for applying voltage to both sides thereof. An OLED device comprising an organic light emitting part including a plurality of pixels to be disposed on the substrate in a sealed inner space, A water decomposition type water removal unit disposed at a predetermined position of the enclosed internal space of the OLED element and reacting with water present in the internal space to generate hydrogen to decompose the water; And One side portion and the other side portion opposite thereto are connected to the inner space and the outer space while being connected from the inner space of the OLED element to the outer space, so that the concentration difference of hydrogen in the inner space and the outer space is different. And a hydrogen removing unit for absorbing the hydrogen present in the internal space and discharging the hydrogen present in the internal space. The OLED device according to claim 1, wherein the hydrogen discharging capacity of the hydrogen removing unit is equal to or more than a hydrogen generation amount generated by decomposition of water by the water removing unit. The method of claim 2, wherein the sealing layer is, the glass, including, but not limited to, hydrogen-permeable ^{1.0x10 -16 [mole · m / m} 2 · sec · Pa] or less polymeric material or a hydrogen-permeable 1.0x10 ^-10 An OLED device characterized in that it is made of at least one of metal materials of [mole · m / m ² · sec · Pa ^0.5 ] or less. The method of any one of claims 1 to 3, wherein the hydrogen removal portion is i) passing through the center of the sealant, ii) passing between the sealant and the substrate, and iii) between the sealant and the sealing layer. OLED device, characterized in that arranged in at least one way of passing through. An organic light emitting portion comprising at least a substrate and a plurality of pixels arranged on the substrate and forming a matrix arrangement, wherein the pixels are composed of an organic light emitting layer and two electrode layers disposed on both sides thereof to apply voltage to the organic light emitting layer. To An edge portion facing the substrate while covering all of the organic light emitting portion on the substrate is sealed by a sealant to provide a sealed inner space between the substrate and the sealing layer in which the organic light emitting portion is located in the inner space. ; And It is disposed at a predetermined position of the sealed inner space and has a water-decomposable water removal unit that decomposes the water while generating hydrogen by reacting with the water present in the inner space, In particular, the sealing layer is made of a material having a hydrogen permeability and absorbs the hydrogen present in the inner space by the difference in the concentration of hydrogen in the inner space and the outer space to pass through it and to be discharged to the outer space. However, OLED device characterized in that it has a hydrogen discharge capacity of more than the amount of hydrogen generated by the decomposition of water by the water removal unit. 6. An OLED device according to claim 5, wherein the sealing layer is i) a metal layer made of transition metal or ii) a polymer layer laminated on the metal layer and its inner surface. The metal layer of claim 5, wherein the sealing layer is i) a metal layer made of an alloy containing Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium), or any one thereof. OLED device characterized in that the metal layer and a polymer layer laminated on the inner surface. The method of claim 5, i) passing through the center of the sealant, ii) passing between the sealant and the substrate, and iii) passing between the sealant and the sealing layer, the both ends being Is disposed so as to be exposed to the inner space and the outer space of the OLED element, respectively, to absorb the hydrogen present in the inner space by the difference in the concentration of hydrogen in the inner space and the outer space to be discharged to the outer space through itself. OLED device, characterized in that it further comprises a hydrogen removal unit. The method of claim 1 or 8, wherein the hydrogen removal unit is made of a metal or an alloy of the metal having a hydrogen permeability of greater than 1.0x10 ^-11 [mole.m / m ² · sec.Pa ^0.5 ] at room temperature as a main raw material. OLED device, characterized in that. According to any one of claims 1, 2, 3, 8, wherein the hydrogen removing unit is made of a thin film form by mixing the powder of the metal or alloy of the metal with a polymer, the content of the polymer is 90vol% or less OLED device, characterized in that. According to claim 1 or 8, wherein the hydrogen removing unit of any one metal selected from the group consisting of Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium) or An OLED device, characterized in that made of an alloy containing any one or more as a main raw material. The OLED device of claim 11, wherein the hydrogen removing unit is formed by sputtering the metal on at least one surface of the sealing layer and the substrate.   The method of claim 1 or claim 8, wherein the hydrogen removal portion is a protective film is applied to at least one surface of the portion exposed to the inner space and the outer space of the hydrogen removal portion is damaged or modified. OLED device. The OLED of claim 1 or 5, wherein the water removing unit is formed in a thin film form by using a mixture of a metal hydride, at least one powder and a polymer of the metal, and attached to an arbitrary position in the internal space. device. 15. The OLED device according to claim 14, wherein the metal for removing water is a metal having a greater ionization tendency than zinc. 15. The alkaline earth metal hydride of claim 14, wherein the metal hydride for water removal unit comprises an alkali metal hydride, an alkaline earth metal hydride, an alkali metal hydride including boron or aluminum, and a boron or aluminum. OLED device, characterized in that at least one selected from the group consisting of a ride, and a mixture thereof. According to claim 1 or 5, wherein the OLED element is an active type having a thin film transistor (TFT) capable of independently controlling the voltage supply to each pixel, wherein the sealing layer is made of a transparent material and the organic light emitting part An OLED device, characterized in that the output light is one of a top emission type emitted to the sealing layer and the substrate is made of a transparent material and the output light is emitted toward the substrate. The OLED device according to claim 1 or 5, further comprising an insulating layer covering the upper electrode layer exposed to the internal space among the two electrode layers of the organic light emitting part so as to be insulated from other surroundings. 19. The method of claim 18, wherein the insulating layer is at least one of an inert gas filled in the empty space in contact with the upper electrode layer, an insulating liquid film or a solid thin film covering the upper electrode layer to block contact with other surroundings. OLED device. 15. The OLED of claim 14, wherein the polymer is a thermoplastic resin or a reactive curable resin having a water transmittance (MVTR) of at least 10 g · mil / m ² · day at a temperature of 40 ° C. and 75% RH (relative humidity). device. Board; A TFT layer disposed on the substrate and including at least as many pixels as a thin film transistor (TFT) capable of independently controlling the pixels by performing on / off switching operation for each pixel by an external switching control signal; An organic light emitting layer that emits light when a voltage is applied to the organic light emitting layer, and includes a plurality of pixels including first and second electrode layers disposed on both sides of the organic light emitting layer to apply the voltage to the organic light emitting layer, wherein the plurality of pixels are disposed within the internal space. An organic light emitting part in which the first electrode layer is stacked on the TFT layer to form a matrix array, and the first electrode layer of each pixel is connected to a corresponding TFT; An edge portion facing the substrate while covering all of the organic light emitting portion on the substrate is sealed by a sealant to provide a sealed interior space between the substrate, the organic light emitting portion is located in the interior space, and hydrogen A sealing layer made of a material having no permeability; A water decomposition type water removal unit disposed at a predetermined position of the enclosed internal space of the OLED element and reacting with water present in the internal space to generate hydrogen to decompose the water; An insulating layer covering the second electrode layer of the organic light emitting part to be insulated from other parts of the periphery; And One side portion and the other side portion opposite thereto are connected to the inner space and the outer space while being connected from the inner space of the OLED element to the outer space, so that the concentration difference of hydrogen in the inner space and the outer space is different. And a hydrogen removing unit for absorbing the hydrogen present in the inner space and discharging the hydrogen in the inner space. Board; A TFT layer disposed on the substrate and including at least as many pixels as a thin film transistor (TFT) capable of independently controlling the pixels by performing on / off switching operation for each pixel by an external switching control signal; An organic light emitting layer that emits light when a voltage is applied to the organic light emitting layer, and includes a plurality of pixels including first and second electrode layers disposed on both sides of the organic light emitting layer to apply the voltage to the organic light emitting layer, wherein the plurality of pixels are disposed within the internal space. An organic light emitting part in which the first electrode layer is stacked on the TFT layer to form a matrix array, and the first electrode layer of each pixel is connected to a corresponding TFT; An edge portion facing the substrate while covering all of the organic light emitting portion on the substrate is sealed by a sealant to provide a sealed inner space between the substrate and the sealing layer in which the organic light emitting portion is located in the inner space. ; An insulating layer covering the second electrode layer of the organic light emitting part to be insulated from other parts of the periphery; And It is disposed at a predetermined position of the sealed inner space and has a water-decomposable water removal unit that decomposes the water while generating hydrogen by reacting with the water present in the inner space, In particular, the sealing layer is made of a material having a hydrogen permeability and absorbs the hydrogen present in the inner space by the difference in the concentration of hydrogen in the inner space and the outer space to pass through it and to be discharged to the outer space. However, OLED device characterized in that it has a hydrogen discharge capacity of more than the amount of hydrogen generated by the decomposition of water by the water removal unit. The method of claim 21 or 22, wherein the insulating layer is at least one of an inert gas filled in the empty space in contact with the second electrode layer, an insulating liquid film or a solid thin film covering the second electrode layer to block contact with another. OLED device, characterized in that. 22. The OLED device according to claim 21, wherein the hydrogen discharging capacity of the hydrogen removing unit is equal to or more than the amount of hydrogen generated due to decomposition of water by the water removing unit. 22. The OLED device according to claim 21, wherein the water removing unit is formed in a film form by using a mixture of at least one of metal hydride, a metal, and a polymer in powder form, and attached to an arbitrary position of the internal space. . The OLED device according to claim 25, wherein the metal is a metal having a greater ionization tendency than zinc. The metal hydride of claim 25, wherein the metal hydride for water removal unit is an alkali metal hydride, an alkaline earth metal hydride, an alkali metal hydride including boron or aluminum, and an alkaline earth metal hydride including boron or aluminum. OLED device, characterized in that at least one selected from the group consisting of a ride, and a mixture thereof. The method of claim 22, i) Penetrating in the middle of the sealant, ii) passing between the sealant and the substrate, and iii) passing between the sealant and the sealing layer, both ends of the OLED Hydrogen disposed so as to be exposed to the inner space and the outer space of the device, respectively, by absorbing the hydrogen present in the inner space by the difference in concentration of hydrogen in the inner space and the outer space to be discharged through the self to the outer space OLED device, characterized in that it further comprises a removal unit. The OLED of claim 21 or 28, wherein the hydrogen removing unit has a protective film coated on at least one surface of the portion exposed to the internal space and the external space to prevent damage or modification of the hydrogen removing unit. device. 29. The method of claim 21 or 28, wherein the hydrogen removal unit is mixed with a polymer in the powder of the metal or an alloy of the metal having a hydrogen transmittance greater than 1.0x10 ^-11 [mole m / m ² · sec · Pa ^0.5 ] at room temperature. However, the OLED device, characterized in that made of a thin film using a mixture of the polymer content of 90vol% or less. 29. The metal according to claim 21 or 28, wherein the hydrogen removal unit is any one metal selected from the group consisting of Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium). An OLED device, characterized in that made of an alloy containing any one or more as a main raw material. 32. The OLED device of claim 31, wherein the hydrogen removing unit is formed by sputtering the metal on at least one of the sealing layer and the substrate. 23. The display device according to claim 21 or 22, wherein the OLED element is made of a transparent material such that the sealing layer is made of a transparent material so that the output light of the organic light emitting part is emitted toward the sealing layer and the substrate is made of a transparent material. The OLED device, characterized in that any one of the bottom emission type emitted to the substrate. 23. An OLED device according to claim 22 wherein the sealing layer is i) a metal layer made of transition metal or ii) a polymer layer laminated on the metal layer and its inner surface. 23. The method of claim 22, wherein the sealing layer is i) a metal layer made of an alloy containing Pd (palladium), V (vanadium), Ta (tantalum), Zr (zirconium) or Nb (niobium), or any one thereof. OLED device characterized in that the metal layer and a polymer layer laminated on the inner surface.

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