JPS6251192A - Electric field light emitting element - 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 electroluminescent device suitable for back light sources such as liquid crystal display devices, EL devices, and the like.

(Prior art and its problems) As a conventional electroluminescent device, for example, as shown in Fig. 2,
The conductivity of the transparent conductive film 21 is such that a transparent conductive film 21 is provided with a transparent quadrielectric layer 21B on a transparent resin substrate 21A [21B is covered with a moisture-proof film 26 on both sides of the basic structure in which a light emitting WJ 22, a reflective insulation 1i 23, and a back electrode 24 are sequentially laminated. It is known that the film is coated and the periphery of the film is sealed with an adhesive layer 25.

Such conventional electroluminescent devices have the disadvantage that moisture easily permeates through the adhesive layer, resulting in a short device life.

.

(Means for Solving the Problems) The present invention solves the above-mentioned drawbacks and provides a moisture-resistant electroluminescent device.

That is, the electroluminescent device of the present invention is an electroluminescent device whose both sides are coated with a moisture-proof film, and is characterized in that the peripheral portion of the film is fused and sealed with a laser beam.

Hereinafter, examples of the present invention will be explained with reference to the drawings.

In the electroluminescent device of the present invention, for example, as shown in FIG. The peripheral part 9 of the film 1.1 is fused and sealed by laser beam.

Moisture-proof films include polychlorotrifluoroethylene (hereinafter abbreviated as PCTFE), a composite film of butyl rubber and polyethylene terephthalate (hereinafter abbreviated as PET), a composite film of high-density polyethylene and PET, and a composite film of polyamide and PET. A film or the like is used.

As the transparent electrode, tin oxide (Snug), indium oxide (InzC+), a mixture of tin oxide and indium oxide, zinc oxide (ZnO), etc. can be used using methods such as vacuum evaporation, sputtering, and ion blating. provided on the moisture-proof film.

As the light emitting layer, cyanoethyl cellulose, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, etc.
Fluorescent powders such as zinc sulfide, cadmium sulfide, zinc selenide, zinc sulfate, etc., which are made by doping high dielectric constant resins such as fluorine resins, epoxy resins, and unsaturated polyester resins with atoms that become luminescent centers such as copper and manganese. is used, and is provided by a method such as a screen printing method or a spin code method.

The insulating layer can be made by mixing high dielectric constant powder such as barium titanate (BaTiOx) or titanium oxide (TiO2) into the high dielectric constant resin as desired, using the screen printing method, spin code method, etc. in the same manner as above. It is provided by the following method.

As the back electrode, metal such as gold, silver, copper, aluminum, etc. can be provided by a method such as a vacuum evaporation method, a sputtering method, an ion blating method, etc. in the same way as a transparent electrode, and a metal foil can also be used. You can also do it.

The thickness of each of the above layers is not particularly limited, but usually:
Moisture-proof film is 80-200μm, transparent electrode is 20-5μm
0nm1. The back electrode is 200μm or less, the insulating layer is 20~
40I! m, and the luminescent layer used has a thickness of 20 to 40 pm.

For example, the electroluminescent device of the present invention can be produced by separately creating a laminate in which a transparent electrode, a light-emitting layer, and an insulating layer are sequentially provided on one side of a moisture-proof film, and a laminate in which a back electrode is provided on one side of the moisture-proof film. However, it can be obtained by a method in which both stacked bodies are stacked so that their insulating layers and back electrodes are in contact with each other, and the peripheral parts of both moisture-proof sheets are fused and sealed using a laser beam.

At this time, the laser beams used are a CChCs gas laser of 0.6 μm, a CO gas laser of 5,0, c+m
It is preferable to use an infrared laser, such as a 3.3 μm Cs gas laser, whose thermal energy is easily absorbed by a polymer substance, and it is particularly preferable to use a CO2 gas laser. The irradiation intensity of the laser beam varies depending on various conditions, but it is usually 50 to 100
W or less, and about 10 to 20 W or less with a CO gas laser.

In addition, when providing an insulating layer and a light emitting layer, the above materials are dissolved in a solvent, and the type of solvent used at this time,
The amount is not limited at all as long as it can dissolve the above materials.

In the example shown in FIG. 1 above, both the transparent electrode 2 and the back electrode 5 are provided on the entire surface of one side of the moisture-proof film l, 1.
In the present invention, as shown in FIG. 3 or 4, at least one of the two electrodes 2.5 may be smaller than the moisture-proof film 1, that is, the peripheral portion of the film 1 may be made into an electrode-free portion.

Furthermore, as shown in FIG. 5, a transparent substrate 7 can be provided between the transparent electrode 2 and the moisture-proof film l.

In this case, the transparent electrode 2 is first provided on the transparent substrate 7°, and then the transparent substrate 7 and the moisture-proof film 1 are laminated.Alternatively, the back electrode 5 and the moisture-proof film 1 may be bonded together with the adhesive 8.

Here, the transparent substrate may be a sheet of transparent glass, or a sheet, film, or plate made of polyester resin, polycarbonate resin, polyacrylic resin, polysulfone resin, polyether sulfone resin, polyarylate resin, etc. As the adhesive, a pressure-sensitive adhesive, a heat-activated adhesive, or the like can be used.

Furthermore, as shown in FIGS. 6 and 7, if a sealing resin 6 is provided around the periphery of the moisture-proof sheet 1, the periphery of the electroluminescent element will be sealed with the sealing resin 6, so that the element can be more securely sealed. can be sealed. When providing the sealing resin 6, the above-mentioned materials are dissolved in a solvent and used, but the type and amount of the solvent used at this time are not limited at all.

Furthermore, even if the back electrode 5 and the transparent electrode 2 are both provided on the entire surface of one side of the moisture-proof film 1.1 as shown in FIG. 7, if the sealing resin 6 is provided around the moisture-proof sheet I, This also has the effect of preventing both electrodes from coming into contact with each other.

Here, the sealing resin is a plastic having a melting point comparable to or lower than that of the moisture-proof film, such as P.
CTFE, polyethylene, epoxy resin, polyvinylidene fluoride, etc., and is usually printed on a moisture-proof film, transparent electrode, or back electrode by screen printing.
It is provided with a thickness of 0 to 80 μm.

Alternatively, as shown in FIG. 8, the electroluminescent element may be covered with one moisture-proof film 1, and the bundle ends of the film 1 may be fused and sealed with a laser beam.

(Example) The present invention will be explained below with reference to Examples.

Example 1 A paste obtained by mixing a mixture of 75% barium titanate and 25% by weight of cyanoethyl cellulose resin with dimethylformamide was screened on one side of an aluminum foil with a thickness of 100 μm and a width and length of 1Qcm. Coated by printing and dried to a thickness of 30 μm.
An i-layer was formed.

Furthermore, Zetsu 8! On top of the layer, a paste obtained by dissolving a mixture of 90% by weight of a phosphor made of copper-doped zinc sulfide and 10% by weight of cyanoethyl cellulose resin in dimethylformamide is screen printed, applied and dried. As a result, a light emitting layer was formed with a thickness of 30 μm.

In addition, P with a thickness of 200 μm and a width and length of 10.2 cm
Three transparent electrodes were formed on one side of a moisture-proof film made of CTFE by reactive magnetron sputtering using an alloy target made of 90% by weight In and 10% by weight Sn.
The thickness was 0 nm.

The transparent electrode and back electrode created by this method,
Use grudge paste to remove the nickel lead wire.

Separately, one side of the same moisture-proof film as above was sputter-etched using high-frequency discharge in an argon gas atmosphere, and then an acrylic hot-melt adhesive was applied to a thickness of 30 μm. After stacking the body so that the transparent electrode, the light emitting layer, the back electrode and the adhesive face each other, the three are thermocompression bonded using a hot press, and then CO□ having a wavelength of 10.6 μm is placed around the periphery of this laminate. PCT was performed by irradiating gas laser light under the conditions of output IW, beam diameter 1 mm, and speed 1 mm/sec.
FE was melted and fused to obtain an electroluminescent device.

Example 2 PCTF with a thickness of 200 μm and a width and length of 10.2 cm
2m each on one side of the moisture-proof film made of E.
A back electrode made of aluminum was formed with a thickness of 70 nm by vacuum evaporation, and then an insulating layer and a light emitting layer of 30 nm each were formed on the back electrode in the same manner as in Example 1.
It was provided with a thickness of μm.

Separately, a transparent electrode similar to that in Example 1 was provided on one side of the same moisture-proof film as above to a thickness of 25 nm.

Subsequently, the above two laminates were stacked so that the light-emitting layer and the transparent electrode faced each other, and then the peripheral area was heated by applying light from a CO2 gas laser having a wavelength of 10.6 μm under the same conditions as in Example 1. It was fused and sealed to obtain an electroluminescent device.

Example 3 PCTF with a thickness of 200 μm, a width of 10 cm, and a length of 10 cm
On one side of the moisture-proof film made of E, 90% by weight of In and S
Using an alloy target consisting of 10% by weight of n, a glow discharge was generated in 02 and Ar gas, and a transparent electrode was formed to a thickness of 40 nm by sputtering.

Next, separately from this, the above. A back electrode with a thickness of 500 nm was formed on one side of the same moisture-proof film by vacuum evaporation of aluminum.

The transparent electrode and back electrode created by this method,
Use grudge paste to remove the nickel lead wire.

Then, on the back electrode, a paste obtained by dissolving cyanoethylcellulose in dimethylformamide and kneading the same volume of barium titanate as cyanoethylcellulose was screen printed, applied and dried to a thickness of 30 μm. A continuous 8i layer is formed. At this time, 2 mm around the moisture-proof sheet is left unprinted.

Furthermore, on top of the insulating layer, a paste obtained by dissolving cyanoethylcellulose in dimethylformamide and kneading the same volume of phosphor made of copper-doped zinc sulfide as the cyanoethylcellulose is applied by screen printing and dried. A light emitting layer was formed with a thickness of 30 μm.

Subsequently, a paste obtained by dissolving an epoxy resin in cellosolve acetate was applied by screen printing to the parts of the moisture-proof film where the insulating layer and the light-emitting layer were not printed, and was dried to a thickness of 60 μm.

Next, after overlapping the two laminates so that the transparent electrode and the light-emitting layer face each other, a
Light from a CO□ gas laser having a wavelength of 0.6 μm was irradiated under the same conditions as in Example 1, and the PCTFE and epoxy resin were melted, fused, and sealed to obtain an electroluminescent device.

The electroluminescent device prepared by the methods 1 to 3 was heated at 50°C and 90% relative humidity for 100cm and 40cm.
When operated at 0 Hz, the luminance of the device after 500 hours each maintained 50% or more of its initial value.

(Effects of the Invention) As described above, the electroluminescent device of the present invention has good moisture resistance because both sides are coated with a moisture-proof film and the peripheral portions of the film are heat-sealed using a laser beam.

[Brief explanation of drawings]

1 and 3 to 8 are cross-sectional views showing examples of the electroluminescent device of the present invention, and FIG. 2 is a cross-sectional view of a conventional electroluminescent device. 1... Moisture-proof film 2... Transparent electrode 3... Luminescent layer 4... Insulating layer 5... Back electrode 6... Sealing resin

Claims (1)

[Claims] 1. An electroluminescent device characterized in that both sides of the device are coated with a moisture-proof film, and the periphery of the film is fused and sealed with a laser beam.