JPS6139397A - 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 Field of Industrial Application The present invention relates to an EL panel among flat display panels that will become increasingly necessary, especially in the field of office automation, in line with the trend of information society. Unlike liquid crystal or electrochromic display panels, EL panels are all-solid-state, self-luminous, easy to see even in the dark, and less dependent on viewing angle. In addition, it is thin and lightweight, making it easy to create high-definition screens, and is flicker-free, making it ideal for use as character and graphic displays for personal computers and word processors.

Conventional Structure and Problems Generally, an EL flat panel has a structure in which a transparent electrode, an Nth insulating layer, a phosphor layer, a second insulating layer, and a back electrode are laminated in this order on a glass substrate.

There may be cases where one of the two types of insulating layers is missing.

The transparent electrode and the back electrode are formed into stripes that are perpendicular to each other, and their intersections form light emitting segments. Light emission is observed from the transparent electrode side. Most of the phosphor layers are based on ZnS, and Mn is used as a luminescence activator in the phosphor layer.
or TbF3 is doped.

Since the phosphor layer is made of ZnS in this way, it is sensitive to moisture and its brightness decreases with driving time in the atmosphere. In particular, exposure to ultraviolet light accelerates the reaction with moisture, resulting in a severe decrease in brightness. Therefore, moisture-proofing measures are generally applied to the EL layer side of the glass substrate in EL panels. Conventionally, a glass-like cap was placed over the cap, and an insulating material such as silicone oil was filled inside to make it moisture resistant. Since this glass cap adheres to a completely flat EL glass substrate, it was necessary to polish the surface of the portion that contacts the substrate. Additionally, machining glass into a cap shape has the drawback of increasing costs.

Another method is to directly cover the EL layer up to the back electrode with an inorganic or organic protective film, but these
There is a problem with the operational stability of the L panel.

Panels are prone to dielectric breakdown. Therefore, a moisture-proofing measure that is easy to manufacture, low cost, and highly reliable is desired.

Purpose of the Invention The present invention is easier to manufacture, lower in cost, and
The purpose of the present invention is to provide an EL panel with highly reliable moisture-proof measures.

Structure of the Invention Unlike the conventional method of directly covering a glass cap or an inorganic or organic protective film, the present invention uses a metal cap processed into a cap shape on the EL layer side of a glass substrate, which includes electrically insulating granular spacers. It has a structure in which the edges of the cap are bonded using an organic resin adhesive. The granular spacer is E
It prevents contact with the transparent electrode and back electrode of the L layer and maintains electrical insulation between these electrodes and the cap. As the metal cap, aluminum metal is suitable because it is light and easy to process.

Description of Examples A transparent electrode (indium, tin mixed crystal oxide), 5rTi03. Y2o3 stacked type first insulating layer, Zn
The S:Mn phosphor layer, the Y2O2, BaTa2O6 laminated second insulating layer, and the back electrode made of AL were stacked in this order to create the EL panel shown in the figure. transparent electrode,
The AL back electrodes are striped and perpendicular to each other.
A matrix of multiple luminescent segments is formed at the intersection points.

In the figure, 1 is a glass substrate, 2 is a transparent electrode, and 3 is a first
Insulating layer, 4 is fluorescent layer, 6 is second insulating layer, 6 is AL back electrode, 7 is AL moisture-proof cap, 8 is epoxy adhesive, 9 is granular spacer, 1° is zeolite powder and urethane resin acts as a desiccant in the composite film.

The figure is drawn schematically, and in reality, the EL layer consisting of 2, 3, 4° 6 and 6 is very thin compared to the cap 7 and the glass substrate 1. The cap of No. 7 is made of AL and has a thickness of 2 to 3 mm. On the side facing the EL layer, there is an indentation at a depth of 0.6 to 1 cm, and it is easy to see in the indentation. Even if this cap has ridges or curves along its surface, there is no problem.

This is because due to the elasticity peculiar to metals, by applying adhesive 8 to the edge of the cap, placing it on the glass substrate 1, and applying light pressure uniformly from the top and bottom of the cap and the glass substrate, the undulations and bends can be corrected. When the adhesive hardens, it comes into close contact with the glass substrate 1. For the cap, AL is preferable from the viewpoints of ease of processing, lightness, and corrosion resistance, but it is not particularly specified, and other similar metals will have the same effect. If such an Al metal cap is conventionally made of glass, processing it into a similar structure will cost about five times as much because the edge surface must be flattened so as to come into close contact with the glass substrate.

Epoxy adhesive is preferably used as the adhesive in step 8, as it is the most impermeable material to moisture. In order to ensure insulation between the metal cap, the transparent electrode, and the Al back electrode, a small amount of electrically insulating granular spacer is mixed in advance and applied to the edge of the cap to bond it to the glass substrate. Rutile sand with a diameter of about 100 μm was used as the granular spacer. This is convenient because the surface of the particles is smooth and rounded, and the transparent electrode or Al back electrode will not be damaged when the adhesive is applied and applied to the glass substrate.

In addition, spherical particles of glass and organic resin in the form of two Al2O3 particles can also be used, and have electrical insulation properties of 50 to 200 μm.
diameter is easy to use.

Inserting a desiccant as shown in 10 inside the cap is effective in further extending the brightness life of the EL. This has been known for a long time and can be easily combined with the present invention to create a very reliable EL.
You can create panels.

For example, an EL panel with the above-described moisture resistance measures could easily maintain a brightness of 70 degrees or more after 10,000 hours when the entire surface was operated to emit light in the same manner as in use. Also, thin film E
There was no dielectric breakdown of the L layer.

Effects of the Invention The EL panel equipped with the moisture protection device of the present invention has high luminance stability and dielectric breakdown resistance, and is easy to manufacture and low cost, making it highly practical and industrially superior. It is something.

[Brief explanation of the drawing]

The figure shows an E equipped with a moisture-proof device in one embodiment of the present invention.
FIG. 3 is a cross-sectional view of a portion of the L panel. 1...Glass substrate, 2...Transparent electrode,
3... First insulating layer, 4... Fluorescent layer,
6... Second insulating layer, 6... Back metal electrode, 7... Metal moisture resistant cap, 8...
Organic adhesive, 9... Granular insulating spacer, 10
・・・・・・Sheet-like desiccant.

Claims (2)

[Claims] (1) A metal cap-shaped envelope is used to cover the glass substrate on which the EL layer is formed, and electrically insulating granular spacers are included to bond and seal the edge portion of the envelope and the substrate. An EL panel characterized by using an organic resin adhesive. (2) The EL panel according to claim 1, wherein an aluminum metal is used as the cap-shaped envelope.