JPS62128484A - Thick film el device - 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] [Industrial Application Field] This invention is directed to thick film E L (EIecLro Lumi
This invention relates to a thick film EL device in which a moisture-proofing agent is injected to protect the device from moisture.

[Prior art and its problems]

Thick film EL elements are, for example, disclosed in Japanese Patent Publication No. 57-38,632.
As disclosed in the above publication, a transparent surface electrode is formed using a transparent conductive material such as ITO on a transparent substrate such as glass or a plastic film by an appropriate method such as vapor deposition or sputtering. On top of this, a phosphor powder consisting of a base material such as ZnS, an active material such as Cu, and an activating material such as Cl is dispersed in an organic binder to form a paste, and a light emitting layer is formed by an appropriate method such as screen printing. Then, on top of that, an insulating layer is formed by dispersing an insulating material such as Ti02 or BaTi03 in an organic binder and making it into a paste by a suitable method such as screen printing, and on top of that an insulating layer is formed so as to face the surface electrode. A back electrode is formed from a conductive material such as Sn by a suitable method such as vapor deposition.

In the thick film EL element having such a structure, the light emitting layer emits light in response to voltage application between the two electrodes.

However, such thick-film EL devices have problems in that the light-emitting layer turns black or the layers peel off when exposed to moisture.

[Purpose of the invention]

This invention was made in consideration of the above-mentioned problems, and is a thick film E which can suppress the occurrence of adverse effects caused by moisture.
The purpose is to provide an L element.

[Structure of the invention]

In order to achieve the above object, the configuration of the present invention is to form a light emitting layer between a transparent front electrode and a back electrode, seal them with a protective member, and apply a voltage between the two electrodes. Accordingly, in the thick-film EL element in which the light-emitting layer emits light, a moisture-proofing agent is interposed inside the protective member.

〔Example〕

FIG. 1 shows a first embodiment of the invention, in which a thick film E
The L element l is formed by a conventional method.

That is, in the thick film rF, L element 1, a transparent surface electrode 3 is formed on a transparent substrate 2 made of glass using a transparent conductive material such as rTo by an appropriate method such as vapor deposition or sputtering. , and then a matrix material such as ZnS, an active material such as Cu, and CI! A luminescent layer 4 is formed by dispersing a phosphor powder consisting of an activating material such as phosphor powder into an organic binder and making it into a paste by a suitable method such as screen printing, and then an insulating material such as TiO2 or BaTiO3 is applied on top of the luminescent layer 4. is dispersed in an organic binder to form a paste, an insulating layer 5 is formed by a suitable method such as screen printing, and a conductive material such as Sn is formed on the insulating layer 5 by a suitable method such as vapor deposition so as to face the surface electrode 3. The back electrode 6 is formed by a suitable method.

In order to hermetically seal the thick film EL device 1, spacers 7 are formed on the transparent substrate 2, which is one of the components of the thick film EL device 1, so as to surround the light emitting layer 3. In addition to fixing with an adhesive 8 such as epoxy, a back plate 9 made of a flat plate member such as glass with a thickness of about 2III+ is provided on the spacer 7, and the spacer 7 and the back plate 9 are bonded together with the adhesive 8. Fixed and transparent substrate2. The translucent substrate 2. The spacer 7 and the back plate 9 constitute a protective member 1) of the thick film EL element 1. In order to improve airtightness, the periphery of the protective member 1) is sealed with an adhesive 8. As the protective member 1), without using the spacer 7, the central part of the back plate 9 having a thickness of about 3III1 is polished to form a concave part so as to have an airtight space lO between it and the transparent substrate 2. It may also consist of

After that, the thick film EL element 1 is attached, in which an injection tube 13 made of aluminum or the like is provided in the injection hole 12 provided in the back plate 9.
It is installed in a vacuum chamber (not shown) together with a fluid storage pipe (not shown). Inside the fluid storage pipe, there is a moisture-proofing agent 1 made of a moisture-blocking agent 14 made of a material having a moisture-blocking effect such as silicone or silicone oil, and a moisture-absorbing agent 15 consisting of a material having a moisture-absorbing effect such as molecular sieves.
6 is filled. In this state, the moisture proofing agent 16 is injected into the protective member 1).

After that, the injection tube 13 is cut, and the photocurable resin adhesive 17 is
By sealing the injection hole 12 and further fixing with the adhesive 8, the EL element 1 with a thickness of 1]1) is completed.

As described above, by injecting the moisture-proofing agent 16 consisting of the moisture blocking agent 14 and the moisture absorbing agent 15 into the protective member lI of the thick-film EL element 1, the moisture-proofing agent 16 can penetrate into the inside of the protective member 1) of the thick-film EL element 1. The moisture blocking agent 14 can block moisture from penetrating into the luminescent layer 3, etc., and the moisture absorbing agent 15 can absorb the moisture. This can prevent peeling off.

Note that the moisture absorbent 15 can be used in liquid or gel form, and the moisture blocker 14 may be omitted.

2 and 3 show a second embodiment of the present invention, in which a thick film EL element 20 is constructed by first forming a back electrode 21 using conductive metal foil such as aluminum foil, and then An insulating layer 22 and a light emitting layer 23 similar to those of the first embodiment are sequentially laminated by a suitable method such as screen printing, and on top of that, a transparent conductive material such as ITO is formed on the surface facing the back electrode 21. A light-transmitting synthetic resin film 25 such as a transparent polyester film formed by an appropriate method such as printing is disposed as the front electrode 24, while a film 25 of a transparent synthetic resin such as a molecular sieve or the like according to the first embodiment is disposed on the back of the back electrode 2. A spacer 26 made of a transparent or non-transparent material such as polyester, which is formed into a frame shape by an appropriate method such as screen printing, is made of a moisture absorbent and an organic binder that have the same effect as the moisture absorbent shown in . A base 27 made of a synthetic resin film is arranged, and an airtight space 28 is formed between the back electrode 21 and the base 27.
have. Both outer surfaces of the film 25 on which the back electrode 21 and the front electrode 24 are formed are protected by a thermoplastic polymer transparent sheet member such as a trifluorochloroethylene film with an adhesive prepared on one side. Member 29.
30 are disposed, and the protective members 29 and 30 are adhesively bonded to each other by a suitable method such as a lamination method under heating conditions above the plasticizing temperature of the protective members 29 and 30.

A press-fit hole 3 is provided through which a part of the base 27 drawn out to the outside of the protection member 29, 30 is communicated with the airtight space 28.
1, the injection hole 31 is filled with a moisture barrier agent 32 having the same effect as the moisture barrier agent shown in the first embodiment, such as silicone or silicone oil, and then the injection hole 31 of the base 27 Thick film EL element 2
0 is completed.

By injecting the moisture-proofing agent 32 into the protective members 29 and 30 of the thick-film EL element 20 in this way, it is possible to prevent the light-emitting layer 23 from turning black and peeling off between the eyebrows, as in the first embodiment.

Note that, as in the first embodiment, the moisture proofing agent 32 can be used in liquid or gel form.

4 and 5 show a third embodiment of the present invention which is a modification of the second embodiment, in which a cut groove 33 is provided at at least one location of the spacer 26 formed on the base 27, Due to this groove 33, the moisture-proofing agent 32 injected into the airtight space 28 penetrates from the back side of the back electrode 21 to the surrounding area, goes around to the light emitting layer 23 side, and spreads throughout the inside of the protective member 29.30. , the structure can protect the light emitting layer 23 and the like from moisture more than the second embodiment. In this case, since a transparent moisture proofing agent 32 can be used, there is no concern that it will greatly impede the light emission of the light emitting layer 23.

Although the present invention has been described in detail above, changes can be made as appropriate within the scope of the gist of the invention. For example, the back electrode 21 of the second and third embodiments may have the same structure as the front electrode 24, and the thick film EL element 20 may be of a double-sided emitting type.

〔Effect of the invention〕

As described above, in the present invention, a light-emitting layer is formed between a light-transmitting front electrode and a back electrode, these are sealed with a protective member, and the In a thick-film EL device in which a light-emitting layer emits light, by interposing a moisture-proofing agent inside the protective member, it is possible to provide a thick-film EL device that can suppress the occurrence of adverse effects due to moisture.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts of a thick film EL device which is a first embodiment of the present invention, and FIGS. 2 and 3 are a sectional view of a thick film EL device which is a second embodiment of this invention.
4 and 5 are a cross-sectional view and a plan view of a main part of a thick film EL element according to a third embodiment of the present invention. 1.20... Thick film EL element 2.24... Surface electrode 3.23... Light emitting layer 4.22... Insulating layer 5.21... Back electrode 1), 29.30...・Protective member 14... Moisture blocking agent 15... Moisture absorbing agent 16, 32... Moisture proofing agent Patent applicant Nippon Seiki Co., Ltd. Representative Patent attorney Mamoru Ushiki 1) 1aff Fig. 2 w3 Fig. v 1[ 4FI! J @Figure 5

Claims (3)

[Claims] (1) A light-emitting layer is formed between a translucent front electrode and a back electrode, these are sealed with a protective member, and the thickness is such that the light-emitting layer emits light in response to voltage application between the two electrodes. A thick film EL device, characterized in that a moisture proofing agent is interposed inside the protective member. (2) The thick film EL device according to claim (1), wherein the moisture-proofing agent comprises a moisture absorbent. (3) The thick film EL device according to claim (1), wherein the moisture-proofing agent comprises a protective agent consisting of a moisture absorbent and a moisture blocking member.