JPS6364082A - Thin film display panel - Google Patents

Abstract

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

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a thin film EL display panel.

[Conventional technology]

FIG. 3 shows a cross-sectional view of an alternating current driven double insulated 1lII film EL display element, which is a typical element structure of a thin film EL display element. Transparent 1 on substrate 1 such as glass! Pole 2° first insulator layer 31 light emitting layer 4. Second insulator J'*5. Back electrode 61!
- Laminated structure. 1st. The second insulator layers 3 and 5 are Y
It is formed of a transparent dielectric film such as 2O3, 5isNn, TazOs, BaTiOs, etc. Further, the light-emitting layer 4 is made of ZnS or the like as a matrix to which a light-emitting center such as Mn is added. These insulator layers and light emitting layers can be formed by sputtering, vacuum evaporation, MOCVD, atomic layer epitaxial method (
It is formed by a film forming method such as ALE (ALE method), and the thickness of the entire constituent film of the element is very thin, less than 2 microns.

By fully applying a high voltage between both electrodes of this thin film EL display element, thermionic electrons accelerated by the electric field collide and excite the luminescent center to emit vL field light. In the multilayer thin layer structure shown in FIG. 3, by forming the electrodes 2 and 6 in the form of a large number of stripes that overlap each other, a thin film EL panel with a dot matrix display can be obtained.

At present, thin film EL panels with a yellow-orange monochrome display using ZnS:Mn as a light-emitting layer are in practical use. By changing the material of the light-emitting layer other than yellow-orange, it is possible to obtain a light-emitting color unique to that material. For example, ZnS:TbFs is displayed in green.

Although there are various panel structures that use two or more different light-emitting materials to realize full-color and multi-color display thin-film EL display panels, there is an effective panel structure that takes advantage of the characteristics of thin-film EL elements. There is a structure in which two panel substrates are pasted together.

In this structure, thin film EL elements of different luminescent colors are formed on two glass substrates and then laminated together in a matching manner.The cross-sectional structure is shown in Fig. 2. Electrodes 11, insulating layer 12, light emitting layer 13, insulating layer 14, and electrode 15 of glass substrate 10 are laminated in order, and electrode 17, insulating layer 18, and light emitting layer 11 are stacked on first panel substrate and glass substrate 16.
9. The second layer in which the insulating layer 20 and the electrode 21 are sequentially ta/d
As shown in FIG. 2, the panel substrate is bonded to the inside of the device forming side. Electrode 11, 15°2
Reference numeral 1 is formed of a transparent conductive film, and 2 the light emitted from the light emitting layer 13 and the light emitting layer 19 can be seen from the substrate 10 side.

Therefore, by composing the light-emitting layers 13 and 19 with materials of different luminescent colors, a thin-film EL display panel with multicolor display can be obtained. This type of display panel is formed by dividing elements of different luminescent colors on a single substrate, or
-Easy to manufacture compared to a structure formed by stacking
Also, high yields are expected.

[Problem that the invention seeks to solve]

In the above-mentioned laminated panel, two panel substrates can be laminated by simply stacking them together as they are, or by applying adhesive to the entire surface, but in these methods, it is difficult to connect the Suitable for short-circuit and dielectric breakdown propagation type. In a thin film EL element, it is difficult to completely eliminate the occurrence of dielectric breakdown caused by defects. Therefore, care is usually taken to ensure that by selecting all materials for the insulating layer and the calculator, the dielectric breakdown will be a self-healing type of breakdown that will be completed with a minute pinhole that does not impair practicality. However, if the electrodes 15 and 21 on the top of the element are solid, the heat generated during dielectric breakdown will not be dissipated and the dielectric breakdown will propagate and cause a large breakdown, impairing its practicality.

Therefore, as shown in FIG. 2, two panel substrates are usually pasted together so that a gap 23 is maintained between them. Oil may be injected into the gap 23. With such a structure, if the surface shape of the ki panel is small and the evaporation is low, so if the gap 23 can be made thicker, there will be no color difference, but in high-resolution display panels, the panel size is reduced to avoid color shift. There is a mounting that narrows the gap between the substrates (particularly in the case of large-area panels), and external pressure can easily cause two panel substrates to come into contact and cause a short circuit, or if they are in close contact. There is a problem that the dielectric breakdown becomes a propagation type when the dielectric breakdown occurs in a state where the dielectric breakdown occurs.

[Means for resolving the problem]

In the present invention, a first panel substrate in which a thin film EL element is formed on a first substrate and a second panel substrate in which a thin film EL element is formed in a second substrate are connected to surfaces on which the N-film EL elements are respectively formed. In the thin film EL display panel, which is bonded together with the two panel substrates facing each other, the first panel substrate and the second panel substrate are configured by dispersing either inorganic material particles or resin material particles. .

[Effect]

In the present invention, in a glass laminated thin EL display panel, if the gap between the panel substrates is widened, it will cause seven colors to shift depending on the viewing angle, but if the gap is too narrow, the two panels will be separated. An electrical short circuit may occur between the boards or a discharge may occur between both panel boards. Furthermore, since heat does not escape during dielectric breakdown, large propagation-type breakdowns tend to occur. The gap between the two panel substrates is preferably from 2 microns to 200 microns, although it varies depending on the application of the laminated thin & EL display panel and the resolution of the panel. Therefore, by dispersing particles with a diameter of 2 microns to 200 microns between the panel substrates as spacers, the p spacing can be secured, and even if dielectric breakdown occurs at the part where the particles and the thin film EL element are in contact, Since the particles are small, the area of contact is small, and insulation failure does not propagate to the extent that it impairs practicality.

〔Example〕

Next, embodiments of the present invention will be described with reference to all the drawings.

Referring to FIG. 1, which shows an embodiment of the present invention, a glass substrate 10 has an ITO transparent 4-electrode as an electrode 11, a Y2O3 gland as an insulating layer 12, and a ZnS:Sm as a light emitting layer 13.
, F thin film, Y2O3 as the insulating layer 14, upper 1!
ITO films are laminated as poles 15 to form a first panel substrate. Further, on a glass substrate 16, an ITO film electrode 17, a Y2O3 absolute layer 18, ZnS:'rb,
A light emitting layer 19 of F, an insulating layer 20 of Y2O3 film, and an upper electrode 21 made of ITO? A second panel substrate is formed by forming a groove. 1st panel board and gamma 2 panel? 1 Yoshi plate and the surface on which the thin film EL element was formed is inside j, 1
1 and pasted together using the surrounding adhesive part 22. Adhesive part 22
As such, an epoxy resin mixed with glass spheres with a diameter of about 60 microns as a spacer is used. Adhesive part 2
A liquid containing degassed silicone oil mixed with glass particles 24 having a diameter of approximately 50 microns is poured into the gap 23 between the two panels from an injection hole (not shown) provided in advance in a part of the panel 2. inject. Next, the injection hole is sealed with epoxy resin. Substrate 16 for high contrast handling
A black lacquer is applied as a black layer 25 to the back side 16a of the housing.

When an alternating current voltage was applied to the thin film EL display panel constructed as described above, red light was emitted from the first panel substrate, and green light was emitted from the second panel substrate. Furthermore, by causing both panel substrates to emit light at the same time, a mixed luminescent color was obtained.

In the above-mentioned display panel that has been cut, the gap 23 is approximately 50 mm.
The width was as narrow as microns, and there were no short circuits or discharges between the first panel substrates depending on the viewing angle. Furthermore, does dielectric breakdown become propagation type during operation? There was no loss in practicality. Also, if you press the surface of the panel with your finger, #membrane EL
There was a fear that the particles would be directly pressed onto the element, inducing dielectric breakdown, but it was confirmed that such problems did not occur.

In the above manual example, glass spheres were used as the particles, but the same process can also be carried out using alumina particles and resin particles. Preferably, these particles are approximately spherical.

Also, is it necessarily a particle? Although it is not necessary to use it mixed in liquid such as oil, it is easier to manufacture in the event that it gets mixed in with oil etc., and because the refractive index of particles and liquid such as oil is similar, it is possible to prevent the display product from being mixed with particles. It does not damage M. Furthermore, it may be constructed by combining panel substrates with the same luminescent color.

In addition, if the particle size is 2 microns or less, the particles generated when the EL element on one panel substrate undergoes dielectric breakdown will affect the EL element on the other panel substrate, causing a complete dielectric breakdown. When the particle size is 200 microns or more, color blurring may occur depending on the viewing angle.

〔Effect of the invention〕

As described above, according to the present invention, the display quality and absolute reliability of a thin film EL display panel can be completely improved.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional structure diagram showing a thin film EL display panel according to an embodiment of the present invention, Fig. 2 is a cross-sectional structure diagram showing an example of a conventional LJi, f) a cross-sectional structure diagram showing an example of a laminated type thin film EL display panel, Fig. 3 Vi2
FIG. 2 is a cross-sectional view showing the structure of a thin-film EL transducer of electrically insulating type. 10.16...Substrate, 11.15, 17.21
...... Electrode, 12, 14, 18.20...
- Insulating layer, 13.19... Light emitting layer, 22...
...Adhesive part, 23...Gap, 24...
Particles, 25...Black layer. Agent Patent Attorney Uchihara ・−゛Ugly

Claims (1)

[Claims] A first panel substrate in which a thin film EL element is formed on a first substrate and a second panel substrate in which a thin film EL element is formed in a second substrate are placed with the surfaces on which the thin film EL elements are formed on the inside. In the laminated thin film EL display panel,
A thin film EL display panel characterized in that either inorganic material particles or resin material particles are dispersed between the first panel substrate and the second panel substrate.