JPH02253592A - Dispersion type electroluminescence element - Google Patents

Abstract

PURPOSE:To obtain a dispersion type electroluminescence element of a long service life by processing the part of connecting a dielectric layer and a luminous layer in a recessed form as a back electrode, and using a metal lid processed in a plane so that the periphery of the back electrode is made into the adhesive member. CONSTITUTION:On a transparent conductive membrane 2 of a transparent conductive glass 1, a luminous layer 4 is formed by a screen printing, and on the luminous layer 4, a dielectric layer 5 is formed by a screen printing. Then, a metal lid to be a back electrode 6 is thermal-pressed from the upper side of the dielectric layer 5, and the periphery of the metal lid and the periphery of the transparent conductive glass 1 are adhered with an adhesive 7 for sealing to seal up the clearance of them. The back electrode 6 is processed into a recessed form at the part the dielectric layer 5 and the luminous layer 4 are connected, and its periphery consists of the metal lid processed in a plane so as to make the adhesive member, that is, the periphery is composed of a cap- form metal lid making a flange-form, and the metal lid is made of Al, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distributed electroluminescent device.

[Conventional technology]

Conventionally, distributed electroluminescent devices (hereinafter referred to as
In an "electroluminescent device" (referred to as an "rEL device"), an aluminum vapor-deposited film was used as a back electrode.

However, vapor-deposited films of metals such as aluminum can only be porous due to their nature, and as a result, there is a problem in that moisture can enter the device from the back side and reach the light-emitting layer, shortening the device life. .

Therefore, attempts have been made to prevent moisture from entering the device from the back side by placing a glass plate on the back side of the aluminum vapor-deposited film (for example,
0-5104), this not only made the process complicated but also caused an increase in cost.

[Problem to be solved by the invention]

The present invention solves the problems of the prior art described above, namely, the intrusion of moisture into the element from the back side and the complication of the process due to the arrangement of the glass plate, and provides a long-life distributed EL.
The purpose is to provide an element.

[Means to solve the problem]

The present invention achieves the above object by using, as a back electrode, a metal lid in which the part where the dielectric T1 layer and the light-emitting layer contact is processed into a concave shape, and the peripheral part is processed into a flat shape so that it becomes an adhesive part. This is what I did.

In other words, by using the metal lid of the above shape as a back electrode, the thickness of the adhesive layer can be reduced compared to using a flat plate when sealing the periphery by adhering the periphery to the periphery of the transparent conductive glass with adhesive. can be made thinner, and moisture intrusion into the element due to penetration from the adhesive portion can be reduced. Naturally, there is no intrusion of moisture into the element through the back surface 1 through the poles.

■ The back electrode also serves as the back cover for sealing, so
Compared to the case where a glass plate is placed on the back side of the aluminum vapor-deposited film, the number of manufacturing steps is reduced and costs can be reduced.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing an embodiment of the distributed EL element of the present invention.

In the figure, (1) is a transparent conductive glass serving as an electrode from which light is extracted, and this transparent conductive glass (1) is made of ITO (indium tin composite oxide) on one side of a transparent glass plate (2). ) A transparent conductive H(3) such as a film is formed.

(4) is a light emitting layer, (5) is a dielectric layer, and the light emitting layer (4) is a dielectric layer.
) is composed of a mixture of a phosphor such as ZnS:Cu, CI and an organic binder such as cyanoethylated pullulan, and the dielectric layer (5) is made of BaTi0. and an organic binder such as cyanoethylated pullulan.

(6) is a back electrode, and this back electrode (6) is a dielectric layer (
5) A metal lid in which the part where the light-emitting layer (4) and the light-emitting layer (4) come into contact is processed into a concave shape, and the peripheral part is processed into a flat shape so that it becomes an adhesive part, that is, a cap-shaped metal lid with a brim-like peripheral part. In this embodiment, the metal lid is made of aluminum.

(7) is a sealing adhesive for bonding the periphery of the metal lid serving as the back electrode (6) and the periphery of the transparent conductive glass (1); adhesive (7
) is used as epoxy resin. The thickness of this sealing adhesive (7) is approximately 10 μm.

The above-mentioned distributed EL element is manufactured, for example, as follows.

A light emitting layer (4) is formed on the transparent conductive film (2) of the transparent conductive glass (1) by screen printing, and a dielectric layer (5) is formed on the light emitting layer (4) by screen printing. Next, cover the metal lid that will become the back electrode (6) with a dielectric layer (
5) Heat compression bonding is performed from the upper surface side, and the peripheral portion thereof and the peripheral portion of the transparent conductive glass (1) are adhered with a sealing adhesive (7) to seal the gap between the two.

Next, a comparative example will be explained with reference to FIG.

The dispersion type EL device of the comparative example shown in FIG. 2 uses a flat aluminum plate as the back electrode (6), and is manufactured in the following manner.

That is, the same transparent conductive glass (1) as in the above example.
A light emitting layer (4) and a dielectric layer (5) are formed on the transparent conductive film (3).
) are sequentially formed, and then a flat aluminum plate larger than the light emitting layer (4) and dielectric layer (5) is attached to the back electrode (
As 6), the dielectric layer (5) is bonded by thermocompression, and its periphery is coated with a sealing adhesive (7) on the periphery of the transparent conductive glass (1).
) to seal the gap between the two, thereby producing a distributed EL element. In the dispersion type EL element of the comparative example produced in this way, the thickness of the sealing adhesive (7) was about 200 μm.

100V, 40V for the distributed EL elements of the above example and comparative example.
The device was driven by applying an AC voltage of 0.07, and the time until the brightness decreased by half was measured to determine the lifespan. The results are shown in Table 1.

Table 1 [Effects of the Invention] As explained above, according to the present invention, a long-life dispersion type EL element is provided. Furthermore, since the metal lid used as the back electrode also serves as the back cover for sealing, the number of manufacturing steps can be reduced compared to the case where a glass plate is disposed on the back side.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the distributed EL element of the present invention. FIG. 2 is a sectional view of a dispersion type EL element of a comparative example. (1)...Transparent conductive glass, (4)...Light emitting layer, (5)...Dielectric layer, (6)...Back electrode 1...
・Transparent conductive glass 4...Light emitting layer 5...Dielectric layer 6...Back electrode

Claims (1)

[Claims] (1) In a dispersed electroluminescent device that uses a mixture of a phosphor and an organic binder as the light-emitting layer (4) and a transparent conductive glass (1) as the electrode on the side from which the emitted light is extracted, a dielectric glass as the back electrode (6). A distributed electroluminescent element characterized by using a metal lid in which the part where the layer (5) and the light-emitting layer (4) contact is processed into a concave shape, and the peripheral part is processed into a flat shape so as to serve as an adhesive part. .