KR100406567B1 - Organic Electroluminescent Display Device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to providing a sintered body that effectively absorbs moisture to support the organic EL display element at the same time as the dehumidifying agent in order to maximize the service life of the organic electroluminescence display device.

According to the present invention, when the porous sintered body is used simultaneously as the support for the dehumidifying agent, the dehumidifying ability is improved compared to when the dehumidifying agent is put on the upper part of the existing support, the manufacturing process is simple, and the manufacturing cost of the EL display element is low, and the process reproducibility is a single crystal. It is remarkably superior to the type, powder type, and bag type in which the powder is packaged in the membrane.

Description

Organic EL display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent display device. More particularly, the present invention relates to a porous sintered body including a dehumidifying agent used to effectively absorb moisture in an organic EL display device, or a support and a dehumidifying agent as one porous sintered body. It relates to an organic EL display element provided.

In general, an organic EL display device has a fluorescent material sandwiched between two electrodes, and when a voltage is applied, electrons emitted from the electrode collide with the fluorescent material to cause charge and discharge and emit light. Say.

Recently, the organic EL has a mobile phone because of the technical characteristics that can diversify the low-voltage driving and low power consumption, self-luminous (high brightness), fast response speed (a few watts), wide viewing angle, light weight, low production cost and color than the traditional flat panel display It is attracting attention as the next generation display device that is promising for small and medium sized terminals such as mobile phones and PDAs.

The structure of an organic EL device generally has the structure of an anode, an organic thin film, and a cathode layer, and the organic thin film has an ETL (Electron Transport Layer), an HTL (Hole Transport Layer), and an emitting layer (Emitting Layer). ) It is sometimes used to form separate EIL (Electron Injecting Layer) and HIL (Hole Injecting Layer) to reduce the driving voltage.

However, since the organic EL device is a multilayer thin film structure that is very sensitive to moisture, oxygen, light, and the like in the atmosphere and easily decomposes, it must be isolated from moisture and air. Particularly, the phosphor is a part directly related to the performance and lifespan of the EL device. When the phosphor is exposed to moisture, the aggregate (bonded) state and the dispersion state of the particles are sharply lowered, which causes black spots to occur. The brightness and life of the light is drastically shortened.

In order to alleviate this problem, in the device manufacturing process, the problem is solved by using a multi-chamber equipment that transfers the substrate by using a robot in a vacuum atmosphere. Due to the shortening of the device life due to the penetration of over-air, there are many limitations in display applications.

Therefore, there is a need for a method of packaging a moisture absorbent (dehumidifying agent), a dehumidifying agent, and a device to prevent air ingress, and studies on this have been actively conducted.

According to the results reported so far, calcium oxide-based (CaO, CaCO ₃ ) and barium oxide-based (BaO, BaCO ₃ ) materials have excellent dehumidification ability and are evaluated as being applicable to dehumidifying agents of organic EL display elements. Among these, barium oxide-based materials are difficult to utilize as harmful to the human body, and many studies have been conducted to maximize dehumidification using calcium oxide-based materials. Double calcium oxide (CaO) has the ability to absorb about 0.3 cc / g moisture, is reported to be chemically and physically stable, and in particular does not cause out-gasing problems.

The necessity of organic EL display devices has emerged as the next generation flat panel display, and the research and development for this is being activated, so the demand for dehumidifying agents for maximizing the life of the devices is increasing.

However, the type of dehumidifying agent currently used by organic EL manufacturers uses a single crystal type, a powder type and a bag type in which powder is packaged in a membrane.

In the case of powder type, the hole penetrates the surface through pin-hole, and in the case of the bag type packed in the membrane, the porous body is attached to the upper part, and the double-sided adhesive tape is used for the support can. Then, a dehumidifying agent of a powder type or a bag type in which the powder was packaged was attached to the membrane.

An organic EL display element requiring dehumidification is placed on the porous body. Plasma treatment is performed on the edge of the can in order to increase the adhesion between the support can and the organic EL display element. The epoxy is applied to a can that has been subjected to plasma treatment, and then packaged with an organic EL display element.

On the other hand, the single crystal type is expensive, the powder type is poor workability and is known to impede the performance of the device due to the scattering of the powder, the encapsulation type dehumidifying agent in which the powder is packaged on the membrane (Membrane) wrapped the powder in a porous material It is known to be difficult to manufacture in various shapes by laying. In addition, the dehumidifier of the encapsulated type packaged in the powder type or the membrane is not only less capable of absorbing moisture than the sintered body type, but also due to swelling generated during moisture absorption, the sealing of the element and the dehumidifier is lost and the device life is long. There are many problems such as shortening and poor performance.

In addition, the packaging of the dehumidifying agent and the device is also an important part. Conventionally, the canister for supporting the dehumidifying agent and the glass (substrate) of the EL device are sealed with an epoxy sealant. ) Is being used.

In general, the metal (can) and ceramic (glass) used as the support is very bad surface adhesion, there was a problem to increase the adhesion to the stainless steel can (Stainless SteelCanister) by plasma treatment to solve this problem.

In addition, since the can and the glass surface must not be contaminated to maintain a constant adhesion after the plasma treatment on the can, it is known that the adhesive force is rapidly lost when the process period is delayed. It has also been reported to cause contamination.

In particular, the conventional single crystal type, powder type and encapsulating type dehumidifier in which the powder is packaged in the membrane have limitations of dehumidification ability (because of unit density function) and difficulty in large display due to manufacturing process. For packaging of parts and stainless steel cans, there is a problem that the cans must be plasma treated.

Therefore, the present invention has been invented to solve the problems of the prior art, and provides a device using a porous sintered body exhibiting excellent characteristics as a dehumidifying agent of an organic EL display element and directly used as a support of the organic EL display element. There is a purpose.

1 is a graph showing the moisture absorption amount according to the sintering temperature of the sintered body used in the EL display element of the present invention.

2A to 2C show that the dehumidifying agent of the organic EL display element is provided as a sintered body according to the present invention.

3A to 3C illustrate that the support and the dehumidifying agent of the organic EL display element are provided as one sintered body according to the present invention.

<Description of Symbols for Main Parts of Drawings>

10, 20: organic EL display element 12: support stand

14, 22: sintered body 16, 24: EL display element

In order to achieve the above object, the present invention provides an organic EL display device comprising a support, a dehumidifying agent, and an EL display element.

The dehumidifying agent is characterized in that the porous sintered body having a dehumidifying ability.

The support and the dehumidifying agent is characterized in that made of one porous sintered body.

The sintered compact is calcium oxide based (CaO, CaCO ₃ ) barium oxide based (BaO, BaCO ₃ ) or strontium oxide based (SrO, SrCO ₃ ), and the EL element is mounted on the sintered body and sealed between the sintered body and the EL element. To facilitate the edge portion of the sintered body is provided to protrude in the form of a step.

In addition, in the present invention, the bottom surface of the sintered body is waterproofed to prevent moisture and harmful substances penetrating from the outside. The treatment temperature and the treatment time are important in the waterproofing treatment, in particular because excessive treatment sharply degrades the dehumidification capacity. The waterproof treatment is a melt treatment, dip coating, spin coating, printing or taping method using organic materials such as glue or PVC.

As described above, in the present invention, the sintered body is directly used as a support of the organic EL display device, thereby maximizing the dehumidification capacity per unit volume and simplifying the process, thereby making it possible to manufacture a long-life organic EL display device at a low manufacturing cost.

Taken together, when the sintered body is used simultaneously as the support for the dehumidifying agent, the dehumidifying ability is improved compared to when the dehumidifying agent is put on the upper part of the existing support, the manufacturing process is simpler, the manufacturing cost is lowered, and the process reproducibility is the single crystal type, powder type, It is remarkably superior to the bag type in which the powder is packed in the membrane.

In addition, the dehumidification capacity of the same material is affected by the size of the density expressed in mass per unit volume, and the dehumidification capacity is also improved 3 to 6 times because the sintered body is 3 to 6 times denser than the powder.

(Example)

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

1 is a graph showing the water absorption amount of the calcium oxide sintered body used in the organic EL display element according to the sintering temperature. It can be seen that the water absorption amount (dehumidification capacity) decreases as the small diameter temperature is increased.

In order to confirm the dehumidifying ability of the sintered compact used in accordance with the present invention, the weight change of the calcium oxide sintered compact was measured at room temperature (20 ° C.) and 60% relative humidity atmosphere.

The measurement specimen had a size of 40 × 20 × 1 (mm) and a surface area of 17.2 cm 2.

CaO + H ₂ O → Ca (OH) ₂ ... … … … … … … … … … … … Equation 1

As shown in Equation 1, 1 mol of calcium oxide (CaO) may be absorbed in a 1 mol ratio of water (H ₂ O).

This indicates that the amount of water that can be dehumidified is about 0.3 cc of water per 1 g of calcium oxide. The total dehumidification amount (weight ratio) of calcium oxide is expressed by the formula.

H ₂ O (total dehumidification amount) = 1/3 CaO... … … … … … … … … … Equation 2

2A to 2C show an organic EL display element manufactured by the present invention, (FIG. 2A) shows an organic EL display element 10, and (FIG. 2B) as a cross sectional view of an organic EL display element. And a porous sintered body 14 used as a dehumidifying agent adhered to an upper portion of the support 12 made of stainless steel, and an EL display element 16 is provided on the upper portion thereof, and FIG. 2C shows an organic EL display. As a plan view of the element, the EL display element 16 has a larger area than the sintered body 14 and is provided inside the edge of the support 12.

For reference, the support 12 has an edge protruding in a stepped shape to mount the EL display element 16 and the sintered body 14 and to facilitate the sealing process with an epoxy resin.

3A to 3C show an organic EL display element manufactured according to another embodiment of the present invention, (FIG. 3A) shows an organic EL display element 20, and (FIG. 3B) shows an organic EL display. As a cross-sectional view of the element, a conventional support and a dehumidifying agent sintered body are manufactured from one porous sintered body 22, and the EL display element 24 is provided thereon, and FIG. 3C shows an organic EL display element. As a plan view, the EL display element 24 is shown mounted in the internal groove of the sintered compact 22.

The sintered compact uses calcium oxide-based (CaO, CaCO ₃ ) barium oxide-based (BaO, BaCO ₃ ) or strontium oxide (SrO, SrCO ₃ ) and the like with good water absorption.

In addition, in order to prevent moisture and harmful substances penetrating from the outside of the sintered body 22, various organic substances such as waterproofing, ie, glue and PVC, were treated on the back and side surfaces of the sintered body.

The waterproof treatment may be a dip coating, spin coating, printing, taping, or the like.

The sintered body 22 thus treated is directly used as a support for the organic EL display element, and sealing is packaged using glass as a substrate and a direct double-sided tape or epoxy.

According to the present invention, the porous sintered body is used as a support or dehumidifying agent of the organic EL display device, thereby maximizing the dehumidification capacity per unit volume to extend the use time of the device and simplify the process. It provides an effect that allows to manufacture.

The present invention has been shown and described with reference to certain preferred embodiments, but the present invention is not limited to the above-described embodiments and has ordinary skill in the art to which the present invention pertains without departing from the spirit of the present invention. Various changes and modifications may be made by the user.

Claims (7)

In an organic electroluminescent display device comprising a support, a dehumidifying agent, and an EL display element, The dehumidifying agent is provided with a porous sintered body having a dehumidifying ability, an organic EL display element. The method of claim 1, The support and the dehumidifying agent is provided with one porous sintered body, characterized in that the organic EL display element. The method according to claim 1 or 2, And the sintered body is calcium oxide based (CaO, CaCO ₃ ), barium oxide based (BaO, BaCO ₃ ) or strontium oxide based (SrO, SrCO ₃ ). The method according to claim 1 or 2, And an edge portion of the sintered compact to protrude in a step shape in order to mount the EL display element on the sintered compact and to facilitate sealing between the sintered compact and the EL element. The method of claim 2, The side surface and the bottom surface of the said sintered compact were waterproofed, The organic electroluminescent display element characterized by the above-mentioned. The method of claim 1, The support and the sintered body are sealed at an interface by an epoxy treatment, a double-sided tape, or a vacuum adsorption method. The method of claim 5, The waterproof treatment is an organic EL display device using a melt treatment, dip coating, spin coating, printing or taping method using an organic material such as glue or PVC.