JPS6244983A - Electroluminescence apparatus - 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 the Invention The present invention relates to an electroluminescent device in which, for example, the rear side of a thin film electroluminescent element opposite to the light emitting surface is hermetically covered by a back plate.

BACKGROUND ART An electroluminescent device that emits light by applying an alternating current electric field is, as shown in FIG. 5i02 and S i on electrode 2,
A first dielectric layer 3 having a two-layer structure with M n
A light-emitting layer 4 made of ZnS doped with Si3N
A second dielectric layer 5 having a two-layer structure of 4, A, and r20z is laminated in this order by sputtering or vapor deposition, and a back electrode made of A is further formed on the surface of the second dielectric layer 5. 6 is formed in the form I&.

The back electrode 6 and the transparent electrode 2 are each formed in a Madris shape that intersects each other in parallel planes, and the mutual intersection position corresponds to one picture element, thus forming the thin film electroluminescent element 7. can do.

Each constituent film of such thin film electroluminescence 7 contains defects such as pinholes and cracks that occur during the manufacturing process of the light emitting layer 4, etc., and these defects may cause minute dielectric breakdown or Moisture penetrating through the defects may cause local delamination, which causes a decrease in the light emitting performance of the thin film electroluminescent element 7.

Therefore, in order to solve this problem, we developed a transparent glass substrate 1.
After forming the thin film electroluminescent element 7 on top, an adhesive 12 made of epoxy resin or the like is applied in advance to the peripheral edge 11 of the glass plate 10 with the back surface by screen printing or the like, and the adhesive 12 is used to attach the transparent glass. The substrate 1 and the back glass plate 10 are hermetically sealed to form a sealed container 8. Next, water-absorbing silicone oil 13 is injected through the suction hole 9 formed in the rear glass plate 10, and the tt+I made of f&T n-balls, etc.
- The injection hole 9 is sealed 1F with the agent 14. By covering the back side of the thin film electroluminescent element 7 with the silicone oil 13 in this way, even if moisture (humidity) from the outside infiltrates into the sealed container 8, the silicone oil 13 can be removed. The moisture retaining effect prevents the moisture from penetrating into the thin film electroluminescent element 7, and the above-mentioned deterioration of the luminous performance of the thin film electroluminescent element 7 is prevented as much as possible. .

In such prior art, when injecting the silicone oil 13 into the sealed container 8, as shown in FIG.
to store. Inside the vacuum chamber 16 is silicone oil 1.
A container 17 in which S3 is stored is housed. First, the lower opening [-1 of the vacuum +P116 is closed with the base 14,
The inside of the vacuum chamber 16 is depressurized by the pure air source 18 and the sealed container 8 is sealed.
Create a vacuum inside. Next, with the injection hole 9 of the sealed container 8 immersed in the silicone oil 13, the leak valve 18a is
Open it to return the inside of the vacuum chamber 16 to atmospheric pressure. The silicone oil 13 is injected into the sealed container 8 due to this pressure difference. In this way, the operation of injecting the silicone oil 13 must be performed within the vacuum chamber 16, which makes the operation extremely complicated. Further, after injecting the silicone oil 13, it is necessary to seal the injection hole 9 of the back glass plate 10 with the sealing IL agent 14, which poses a problem of further increasing production costs.

Problems to be Solved by the Invention The purpose of the present invention is to solve two technical problems, to prevent micro-dielectric breakdown and glabellar peeling of electroluminescent elements with a simple configuration, and thereby to achieve low-cost, 1. In order to improve workability, we propose an electroluminescent device with 17 features.

Means for Solving the Problems The present invention is an electroluminescent device characterized in that the back side of the electroluminescent element opposite to the light emitting surface is coated with water-absorbing grease.

Function According to the present invention, by simply coating the back side of the electroluminescent element with water-absorbing grease, micro dielectric breakdown of the electroluminescent element and peeling between the eyebrows can be prevented.
Decrease in luminous performance can be prevented. Further, the work is not time consuming and production costs can be reduced.

Example FIG. 1 is a sectional view of one embodiment of the present invention.

The thin film electroluminescent element 20 is similar to the conventional one,
A transparent glass substrate 21, a transparent electrode 22 formed on the transparent glass substrate 21 and made of Ta2('), . The dielectric layer 23 is doped with Mn, etc.
Emission M24 consisting of h' such as 77ns, Si3N, and A
! ,0. tltJ2 dielectric layer 25 consisting of a two-layer structure with
And A! and a back electrode 26 consisting of.

One pixel of the thin film electroluminescent device 20 is configured at each intersection of the back electrode 26 and the transparent electrode 22. The back surface of the thin film electroluminescent device 20 formed on the transparent glass substrate 21 in this manner is coated with silicone grease 27 .

The silicone grease 27 has water absorption properties, and plays the role of preventing water (moisture) from entering into the thin film electroluminescent cord 20, similar to the silicone oil 13 shown in the American technique. Furthermore, since it has electrical insulation properties, it also plays a role in preventing minute dielectric breakdown and deterioration of the characteristics of the thin film electroluminescent element 20, similarly to the silicone oil 13. While the silicone oil 13 is a liquid, the silicone grease 27 is a semi-solid mixture of silicone oil 13 and metal soap.
The back surface of the thin film electroluminescent strip 20, that is, the area W corresponding to all the picture elements can be covered by the screen printing method. To coat the silicone grease 27 by screen printing, as shown in FIG. 2, the surface of the rough cloth 28 of 11 is masked with a mask layer 29, a portion of this mask layer 29 is removed, and the silicone grease 27 is applied. . The back and sides of the thin film electroluminescent element 20 are covered with this cloth 28, and the silicone grease 27 is applied to the cloth 28 using a suppressing member 30 such as a roller.
The oozed silicone grease 27 is applied to the thin film electroluminescent grating 20 through the eyes of the thin film electroluminescent grating 20.
It is applied so as to cover an area W corresponding to all the picture elements.

After applying the silicone grease 27 by screen printing in this way, the back side of the thin film electroluminescent element 20 is hermetically covered with a rear glass plate 31 shown in the first figure. A thermosetting adhesive 32 such as epoxy resin is applied in advance to the peripheral edge 31a of the rear glass plate 31 by screen printing or the like, and the rear glass plate 31 is stacked on the transparent glass J1 (on the plate 21 side). By curing the adhesive 32 while applying a suitable load, the back glass plate 31 can be hermetically bonded to the transparent glass substrate 21, and thus the electroluminescent device 33 according to the present invention can be assembled. can be obtained.

The amount of silicone grease 27 used is as follows:
The amount of silicone grease 27 is selected to prevent the silicone grease 27 from being mixed into the adhesive 32 when the adhesive 32 and the back surface lath plate 31 are bonded to each other. By forming an endless annular gap 34 between the silicone grease 27 and the adhesive 32, the silicone grease 27 enters between the adhesive 32 and the peripheral edge 31a of the back glass plate 31, and This can prevent the adhesive strength from weakening. Furthermore, by performing the steps from applying the silicone grease 27 to curing the adhesive 32 in a dry atmosphere, moisture can be prevented from entering the gap 34 between the silicone grease 27 and the adhesive 32, and the silicone grease 27 can be can maintain its moisture absorption performance over a long period of time.

FIG. 3 is a cross-sectional view of another embodiment of the invention.

FIG. 3 is similar to the structure of FIG. 1, and corresponding parts are given the same reference numerals. In this embodiment, a recess 35 is formed in the center of the rear glass plate 31 so that its cross section is U-shaped. As a result, an airtight space 36 is formed between the silicone grease 27 and the back surface lath plate 31, and the airtight space 36 is elongated in the left-right direction in FIG. , the luminescence of each picture element of the thin film electroluminescent device 20 can be made uniform. However, when forming the airtight space 36 in this way, if the adhesive 32 is thermosetting, the airtight space is What is necessary is to make the volume of 36 as small as possible.

In the embodiment, the thin film electroluminescent device 20
In order to prevent deterioration of the characteristics of the grease, silicone grease 27 is used, but the structure is not limited to this, and other hygroscopic fluorine-based greases may also be used. .

According to the inventor's experiments, by using the silicone grease 27, it was possible to prevent the expansion of the micro-dielectric breakdown region and also prevent delamination due to the containment of outgas from the micro-dielectric breakdown. . It was also found that the silicone grease 27 not only has a great heat dissipation effect, but also has little damage to the constituent films of the thin film electroluminescent element 20 due to temperature changes, vibrations, bending, etc. Therefore, it is understood that the life of the thin film electroluminescent device 20 can be maintained for a long period of time.

According to the present invention, the manufacturing process is significantly simplified by using hygroscopic grease, thereby reducing production costs and improving work performance. can do

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a diagram for explaining the process of applying silicone grease 27 by screen printing, and FIG. 3 is a sectional view of another embodiment of the present invention.
FIG. 4 and FIG. 5 are diagrams for explaining the prior art. 1.21...Transparent glass substrate, 7,20...Thin film electroluminescent element, 27...Silicone grease, 33...Electroluminescent device agent
Patent Attorney Stroke Count Keiichi Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An electroluminescent device characterized in that a back surface of an electroluminescent element opposite to a light emitting surface is coated with water-absorbing grease.