JPS60221791A - Thin film 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 Technical Field This invention provides K L (Ele-
The present invention relates to a thin-film EL panel that emits light, and more specifically relates to a matrix-type or sox-type thin-film Fli-L panel.

Conventional technology Conventionally, for thin-film KL panels operating with AC, a high electric field (about 10° V/cm) is regularly applied to the light-emitting layer.
In order to improve dielectric strength, luminous efficiency, operation stability, etc., 01 to 1.6 wt% of Mn (or C!u, A
A three-layer structure ZnS:Mn (or
n5e:Mn)KL panel has been developed and has been confirmed to have improved luminous properties. This thin film EL panel is several KH2
It emits high-intensity light when applied with an alternating current electric field, and has a long lifespan.

FIG. 1 shows the basic structure of a ZnS:Mn thin film EL panel as an example of a thin film EL panel.

The structure of the thin film EL panel will be explained in detail based on FIG.
The transparent electrode 2 is further layered on top of Y, 01, Ta.
gOs, AAtOs-19i, Na, Sin,
A first dielectric layer 3 consisting of the following materials is formed in an overlapping manner by sputtering, electron beam evaporation, or the like. A ZnS light emitting layer 4 is formed on the first dielectric layer 3 by electron beam evaporation of sintered ZnS:Mnn. At this time, the ZnS:Mn sintered pellet for evaporation and the tongue 1. code is used. A second dielectric layer 5 made of the same material as the first dielectric layer 3 is laminated on the ZnS light emitting layer 4, and a back electrode 6 made of At or the like is further deposited thereon to form a thin film. An EL panel is formed. Transparent type (as shown in Figure 2, the j2 and back electrode 6 are formed into a strip shape, and a matrix and Tsukusumi wedge structure is adopted in which multiple pieces are arranged perpendicular to each other, and the transparent electrode 2 and the back electrode 6 are formed in a flat shape. Diagrammatically, the crossed position (shaded area in Figure 2) corresponds to one pixel 7 of the panel.The transparent electrode 2 and the back electrode 6 are each connected to an AC power source 10 via a switch 8.9, and the thin film The EL panel is driven.

゛ When an AC voltage is applied between the electrodes 2.6, pressure measurement in the ZnS light emitting layer 4 will be induced, and therefore the electric field generated in the ZnS light emitting layer 4 will be excited and accelerated in the conductor. Electrons that have obtained sufficient energy directly excite the Mn luminescent center, and when the excited Mn luminescent center returns to the ground state, it emits orange-yellow light. In other words, electrons accelerated by a high electric field reach the ZnS luminescent center in the ZnS luminescent layer 4.
When the electrons of the Mn atoms entering the site are excited and fall to the ground state, they emit strong light in a wide wavelength range with a peak of approximately 5s 50'X.

The thin-film KL panel having the structure described above can be used as a flat thin display device that takes advantage of the Nubase Factor to display characters, symbols, still images, moving images, etc. It can be used as a means of displaying images, etc., and is very effective.

However, the dielectric N of the thin-film KL panel contains pinholes and microcracks generated during the manufacturing process, and moisture, etc. enters the ZnS light emitting layer 4 through these defects, resulting in heat generation due to EL light emission loss. , causing delamination, deterioration of device characteristics, etc. Moreover, in the thin film EL panel, as shown in FIGS. 8 to 5, the light emitting layer 4 is formed on the entire surface of the thin film EL panel.
The problem is that if the above-mentioned inconvenience occurs in any place, it will expand without limit.

In order to solve the above-mentioned problems, we have developed a technology to prevent and fix the expansion of minute thermal damage areas caused by breakdown caused by pinholes and other imperfections peculiar to thin-film EL panels when energized. Thin film KL is effective for moisture protection, heat dissipation, and vibration and deflection.
panels are known.

This thin film EL spring (V) is arranged on a glass substrate 1 of a thin film EL panel shown in FIG.
Dish-shaped back force glass plates are stacked to accommodate the laminate of the dielectric layer 5 and the back electrode 6, and the joint between the glass substrate 1 and the back glass plate is bonded with photocurable resin (Photobond) or the like. The tail is sealed with an agent. That is, the Gawon group &1 and the back glass plate constitute the envelope of the thin film KL spring p. Then, an insulating protective fluid for protecting the thin film KL panel, such as silicone oil or vacuum grease, is injected into the envelope from the injection port on the rear glass plate, and then the injection port is closed (Japanese Patent Application Laid-Open No. 52-1979-1). 127790).

However, the above configuration is complicated, and furthermore, it is difficult to completely remove moisture from the insulating protective fluid.

Purpose of the Invention Therefore, the present invention aims to locally limit the planar spread of peeling and destruction caused by structural defects in the thin film and pinholes caused by discharge (7), thereby improving overall reliability.
The purpose is to provide panels.

Structure of the Invention The present invention is characterized in that the light-emitting layer is formed only in the pixel portion at each intersection of the transparent electrode and the back electrode.

In other words, in the past, the light-emitting layer was formed over the entire surface of the panel, so if there was even one defect or pinhole, the light-emitting layer would peel off from this point, but in this invention, the light-emitting layer is formed on each panel. Since it is formed only in the pixel area, even if the emissive layer peels off or breaks in one pixel area, the peeling or breakage will remain within that pixel area and will not spread to other pixel areas, so it will not affect the entire panel. Improved reliability.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 shows an enlarged plan view of one pixel portion of the thin-film EL panel, and FIGS. 7 and 8 respectively show cross-sectional views along the line and line of FIG. 6.

The figure is similar to FIGS. 3 to 5 except for the following points, and the same parts are given the same reference numerals and their explanations will be omitted. The differences from Figures 3 to 5 are as follows:
A dielectric layer 32, a light-emitting layer 4, and a second dielectric layer 5 are formed only in the pixel portions at each intersection of the transparent electrode 2 and the back electrode 6, and a third dielectric layer 32 is formed between each pixel portion. The body layer 11 is filled and formed.

Next, an example of a method for manufacturing the thin film EL panel described above will be described. First, a transparent electrode 2 made of a material such as N, O, 5nO7, etc. is formed on a glass substrate 1. Next, Si'O, AL is deposited on the entire surface of the transparent electrode 2 and the glass substrate 1.

01. After a dielectric material such as 13isN4 is vapor deposited or nuparitarned by plasma CVD, the dielectric material at the intersection of the transparent electrode 2 and the back electrode 6 to be formed later is removed by the well-known photo ring fly method, and the dielectric material other than the intersection point is removed by the well-known photo ring fly method. The eighth dielectric layer 11 is formed only in that portion. The photoresist film at this time remained on the third dielectric layer 11! , from above Yt Ox, Tag Os
etc. 1st i'? The a-electric layer 81, the light-emitting layer 4, and the second dielectric layer 5 are sequentially laminated, and the photoresist film and the laminated film thereon are removed by a stencil peeling lift-off method or the like. Finally, a back electrode 6 made of aluminum or the like is formed thereon.

According to the above configuration, since the light emitting layer 4 is formed only in the pixel portion at the intersection of the transparent type JfM2 and the back electrode fM6, there are no defects in the second dielectric layer 5 or the back electrode 6. Pinholes may occur due to discharge, causing the light-emitting layer 4 to become non-emissive or peel off.
Even if Ilk occurs, these disadvantages are limited to that pixel portion and do not spread to other pixel portions. This makes it possible to perform moisture-proofing with a significantly simpler structure, eliminating the need for protection with an insulating protective fluid, and greatly contributing to the reduction in manufacturing costs of thin-film EL panels. Further, by forming the third dielectric layer 11 with a colored opaque dielectric, the contrast is improved and the display quality of the panel is significantly improved.

Effects of the Invention In this invention, as described above, the light-emitting layer is formed only in the pixel area at the intersection of the transparent electrode and the back electrode, so there is no possibility of destruction of the light-emitting layer due to defects or pinholes in the thin film component. Peeling can be stopped only in the pixel portion, and a highly reliable thin film KL panel can be provided.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional thin film EL panel, Figure 2' is a plan view showing the relationship between the transparent electrode and the back electrode, Figure 3 is an enlarged plan view of one pixel portion, and Figures 4 and 5 are 9A and 9B are cross-sectional views taken along the line ■--■ and the line v--■ in FIG. 8, respectively. FIG. 6 is an enlarged plan view of one pixel portion of a thin film EL panel according to an embodiment of the present invention, and FIGS.
FIG. 3 is a cross-sectional view taken along the line ■-■ and the line ■-■ in the figure. 1...Glass substrate, 2...
...Transparent electrode, 8...First dielectric layer, 4...
...... Luminous layer, 5... Second dielectric layer, 6...
......Back electrode, 11...Third dielectric layer. Figure 1 Figure 2 Figure 3 Figure 4r1! J jlI5v! j

Claims (1)

[Scope of Claims] 1. In a matrix-type thin film EL panel in which a first dielectric layer, a light emitting layer, and a second dielectric layer are interposed between opposing electrodes, at least one of which is transparent, the light emitting A thin film KL panel characterized in that a layer is formed independently only at the pixel portion at the intersection of counter electrodes. 2. The thin film EL panel according to claim 1, wherein each of the light emitting layers is surrounded and protected by a dielectric layer.