JPS6097A - El panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field In the recent information society, the role of displays, which are a means of visually transmitting information, has become increasingly important. The present invention relates to a thin-film EL display that is suitable for displaying not only numbers but also characters, symbols, figures, etc., and has the characteristics of being thin and lightweight, due to the rapid progress in integrated circuit technology, and in particular the widespread use of microcomputers. .

Conventional configurations and their problems EL panels are generally divided into powder dispersion type and thin film type.
Furthermore, there are four types of drive methods, AC type and DC type, but all use ZnS as the phosphor layer matrix. One thing that can be said in common is that this compound is sensitive to moisture, which is one of the causes of brightness deterioration during driving. Therefore, the above] ID
For LID use, some form of moisture-proofing must be taken.

Conventionally, the methods of (1) closely covering the entire KL layer with an inorganic or organic film, (2) providing an envelope such as a glass cap, and (3) degassing and vacuuming the inside of the glass cap described in (2) above (4) Fill the glass cap in (2) above with an insulating liquid such as silicone oil; (5) Fill the glass cap in (2) above with silica gel as a moisture absorbent together with an insulating liquid such as silicone oil. Countermeasures have been taken, such as pasting a coated sheet on the inner wall of the cap.

In addition, in order to improve the contrast as well as to prevent moisture, the method (4) of coloring the silicone oil with a dye has been devised.

The above moisture-proofing measures have drawbacks in effectiveness and manufacturing. In other words, method (1) is inconvenient for heat dissipation and self-healing micro-dielectric breakdown of the KL element;
Furthermore, method (2) is insufficiently effective. (3), (4
) and (5) both have manufacturing difficulties, and at the same time, method (3) has the risk of damage to the strength of the flat panel due to the pressure difference between the external atmospheric pressure and the vacuum inside the cap. be. Therefore, there is a need for an EL panel that is easier to manufacture and provides an effective moisture-proof sealing device including contrast.

Purpose of the Invention As described in the structure of the conventional example and its problems, the present invention provides a long-life EL that is effective in preventing moisture, is easy to manufacture, and is provided with a sealing member that also has the effect of improving contrast.
The purpose is to realize a panel.

Structure of the Invention The present invention is characterized in that a mixture of zeolite and light-absorbing colored powder is made into a thick film or ceramic shape and fixed to the inner wall of the upper surface of the seal cap covering the BGL thin film layer.

Description of Examples AC thin film type EL, which has been most actively developed in recent years
This will be explained below using a panel as an example.

Generally, AC thin film type E and TJ panels have a glass substrate coated with striped transparent electrodes, an insulating layer, a phosphor layer, an insulating layer, and an A-e stripe that intersects with the striped transparent electrodes. It is constructed by stacking electrodes in this order. The insulating layer may be provided on only one side. The present invention covers the EL layer with such a structure with a cap made of glass or organic resin with a small space, and the side surface of the KL layer of the cap is colored with zeolite, which is a moisture adsorbent, and which plays the role of light absorption. It has a structure in which a powder mixture is applied in the form of a thick film or fixed in the form of a thin ceramic plate. The end surface of the cap is adhesively fixed onto the glass substrate, and has a structure that blocks external moisture and dirt as much as possible.

In the present invention, zeolite was selected and studied as a moisture absorbent that adsorbs moisture within the cap covering the KL layer and quickly adsorbs moisture even if moisture enters the cap from the outside. The basis for this is as follows.

(1) Zeolite is a type of clay mineral that is stable and harmless to other components of the EL panel.

(2) It has selectivity for adsorbed substances, and the selectivity is determined by the pore distribution derived from the essential crystal structure of zeolite. For example, zeolite with a pore diameter of about 3A can selectively absorb only water in the air. Furthermore, even if zeolite is used with large pores, it has the ability to adsorb polar substances such as water.

(3) It has a greater adsorption capacity than silica gel or activated alumina even when the partial pressure of water is extremely low.

(4) It has greater adsorption capacity compared to activated alumina and silica gel even at high temperatures above room temperature.

First, a case where glass is used as the cap will be described below.

In the case of glass, it is more heat resistant than organic resins, so it is possible to bake it onto the inner wall of the glass as a thick film of a mixed powder of the zeolite powder and light-absorbing colored powder. That is, 5% by weight of carbon powder was added and mixed as a light-absorbing powder to zeolite powder having a pore size of 3X. Unlike white zeolite powder, the mixed powder exhibits strong light absorption and can effectively reduce the diffuse reflectance to 1% or less.

Next, a 7% concentration aqueous potassium water glass solution was added to the mixed powder to form a paste suitable for printing coating, and the paste was coated on the inner wall of the glass camp to a thickness of about 100 to 200 μm.

After drying at 150° C. in a dryer, it was heated at 350° C. for 2 hours in a vacuum using a rotor pump to activate the zeolite (deadsorption gas) and fix the coated film to the glass.

Thereafter, a cap was placed over the AC thin film type EL layer in, for example, a dry atmosphere, and the end surfaces were bonded with epoxy resin. A partial cross section of the completed EL panel of the present invention is shown in the figure. In the figure, (1) is glass camp, (2) is a thick film of mixed powder of zeolite and carbon, (3) is epoxy resin,
(4) is a glass substrate, (5) is a transparent 1' bright electrode, (6) is a ZnS:Mn phosphor layer, (force is a Y2O3 insulator layer, (8)
) indicates the back electrode. The KL panel configured as described above does not have the drawbacks mentioned in the conventional configuration and its problems, and is easy to manufacture without the need to create a vacuum inside the cap or fill it with silicone oil, and has improved contrast. can also be achieved at the same time. 5
As a result of a life test with all segments emitting light simultaneously using a KHz sine wave, it was confirmed that the EL panel retained 90% of its initial brightness after io and ooo hours, and its moisture-resistant sealing effect was excellent. .

In addition to carbon, we also investigated other materials as light-absorbing powders. Essentially strongly colored oxide powders, such as manganese oxide MnO2, chromium oxide Cr2O3,
It has been found that nickel oxide NiO, copper oxide Ou20, iron oxide Fθ304, etc. have no adverse effect on the moisture absorption ability of zeolite during thick film baking at 350°C, and work effectively.

However, in order to give the thick film an appropriate light absorption ability, the addition ratio to the zeolite must be changed appropriately. However, 30% at most is sufficient, and most of the remaining zeolite exhibits a sufficient moisture absorption effect. It is clear in principle that substances other than carbon and oxides can be used as long as they are strongly colored powders and do not adversely affect the performance of zeolites.

In order to further reduce costs, we also considered using a plastic cap instead of a glass cap. In this case, baking at 350°C is not possible due to its low heat resistance, so 10% of a 7% potassium water glass aqueous solution and 20% of clay as an auxiliary binder are added to the mixed powder of zeolite and carbon. 500 kfj/ into a flat plate with a thickness of 1wn
CR! The mixture was press-molded under a pressure of 300° C. and then heated in a rotary vacuum at 500° C. for 2 hours to form a ceramic shape. The ceramic disc thus produced was attached to the inner wall of the epoxy cap using an epoxy resin adhesive to produce a FiL panel having the same structure as shown in the figure. As a result, in the same life test as the glass cap, it maintained 90% of its initial brightness after 10,000 hours, and was found to have a similarly long life.

Although the AC thin film type EL panel has been explained above, it is clear that an EL panel having such a structure can also be constructed with an AC or DC powder type or a DC thin film type, and the effects are similarly clear in principle. .

Effects of the Invention As described above, the present invention is an AC thin film KL in which a mixture of zeolite and light-absorbing powder is made into a thick film or ceramic shape, fixed to the inner wall of a seal camp, and 11 layers are moisture-proof sealed with such a cap. The panel retains 90% of its initial brightness after 10,000 hours in a life test, and at the same time has improved contrast, and is easy to manufacture due to its structure.

In principle, the EL panel of the present invention may be of a powder type, a thin film type, an alternating current type, or a direct current type.

[Brief explanation of the drawing]

The figure shows AC thin film type K with moisture-resistant sealing according to the present invention.
A partial sectional view of the L panel is shown. 1 Nigarasu cap 2: Thick film of zeolite and carbon mixed powder 3: Epoxy resin adhesive 4 Nigarasu substrate 5
: Transparent electrode 6 : ZnS:Mn phosphor layer 7 : Y2
O, insulator layer 8: Rear A4 electrode Patent applicant Isao Abe, Patent attorney representing Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A mixture of zeolite and light-absorbing colored powder
An EL panel characterized in that it is fixed to the upper inner wall of a seal cap that covers an L thin film layer. 2. The EL panel according to claim 1, wherein the mixture is in the form of a thick film. 3. The EL panel according to claim 1, wherein the mixture is ceramic.