JPH03238792A - Electro-luminescence light emitting apparatus - Google Patents

Abstract

PURPOSE:To reduce a manufacturing process and a cost by placing a transparent conductive vapor-transmission-resistant film opposite to an aluminum substrate with the conductive layer inside, adhering its periphery to the substrate with adhesive and laminate-sealing an insulating layer and a light emitting layer inside. CONSTITUTION:With respect to an aluminum substrate 1 equipped with an insulated layer 2 on the back, a transparent conductive vapor-transmission- resistant film 3 comprising a transparent film base 3 equipped with a transparent conductive layer 5 is placed opposite to the substrate 1 with the conductive layer 5 inside. Its periphery is adhered to the substrate 1 with adhesive 7 as well as an insulating layer 8 on the substrate 1 side and a light emitting layer 9 on the film 3 side are laminated and sealed. Thus a manufacturing process and a manufacturing cost can be reduced as well as a whole apparatus can be thin.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an EL (EL) used in display devices, etc.
The present invention relates to an electroluminescent (electroluminescent) light emitting device, and more particularly to the above light emitting device using a transparent conductive moisture permeable film as an electrode.

[Conventional technology]

As shown in FIGS. 2 and 3, this type of EL light emitting device consists of an insulating layer 22 provided on an aluminum substrate 21, a transparent substrate 23, and a transparent conductive layer 24 on a conductive substrate 25. The provided light emitting layer 26 is overlapped with E.
It is known that an L element is made and this element is covered with a moisture permeable film 29 consisting of a base film 27 made of a polychlorotrifluoroethylene film or the like and an adhesive side layer 28.

The moisture-permeable film 29 is essential to prevent the performance of the EL element from deteriorating due to the external atmosphere.As shown in Figure 3, two of these films cover the entire EL element, and both films are separated. Either the peripheral edges are overlapped and heat-sealed, or as shown in FIG. 2, only one film is used and it is covered from the conductive substrate 25 side, and the peripheral edge is adhesively held on the aluminum substrate 21. It is used in one of two ways.

In addition, in FIG. 2, 30 is an anti-green treatment layer provided on the back surface of the aluminum substrate 21, and in FIG.
32 is an electrode terminal of the aluminum substrate 21, and 32 is an electrode terminal of the conductive substrate 25.

[Problem to be solved by the invention]

However, since the above-mentioned known EL light emitting devices have a complicated layered structure, they are disadvantageous in terms of manufacturing process and manufacturing cost, and also have the disadvantage that the overall thickness of the device is too thick. There is a problem in that when the film is coated and sealed, foreign matter and dirt are attracted to and mixed in due to electrification, resulting in poor sealing and poor appearance. In addition, especially in the light emitting device shown in FIG. 2, there was a problem that warping occurred when the film was covered and sealed because there was a large difference in thermal shrinkage rate between the moisture permeable film and the aluminum substrate.

In view of the above-mentioned conventional problems, the present invention makes it possible to reduce the manufacturing process and manufacturing cost, as well as to make the entire device thinner.
It is an object of the present invention to provide an EL light emitting device that does not cause poor sealing or poor appearance due to electrification, and is free from warping due to thermal shrinkage.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the inventors discovered that using a specific transparent conductive moisture-permeable film,
By using this film as a conductive substrate on which a light-emitting layer is to be provided, that is, an electrode substrate, and also having this film play the same role as a conventional moisture-resistant film, the manufacturing process and cost can be reduced, and the entire device can be made thinner. We discovered that an EL light-emitting device could be obtained that could be used to improve the overall performance of the device, as well as free from the possibility of adsorption or contamination of foreign matter and dust caused by static electricity, and free from warping caused by thermal shrinkage. I was able to complete it.

That is, in this invention, a transparent conductive moisture-permeable film formed by providing a transparent conductive layer on a transparent film base is placed facing an aluminum substrate having an anti-green treatment layer on the back side with the conductive layer inside. The EL light-emitting device has a peripheral edge portion adhered to the substrate with an adhesive, and an insulating layer on the substrate side and a light-emitting layer on the film side are laminated and sealed inside the device. This is related.

[Structure and operation of the invention]

The transparent conductive moisture-resistant film used in this invention is formed by providing a transparent conductive layer on a transparent film base material, and in some cases, a light-emitting layer or an adhesive layer is further provided on this transparent conductive layer. A metal or metal oxide layer may be provided to improve adhesion to the material, and a suitable adhesive layer is usually provided on top of these layers.

As the film base material, a plastic film having flexibility and transparency and usually having a thickness of about 5 to 300 IIm,
For example, polyethylene terephthalate, polyimide, polyether sulfone, polyether ketone, polycarbonate, polypropylene, polyamide, polyacrylic,
Examples include films made of various plastics such as cellulose brochionate, polyvinyl chloride, polystyrene, polyvinyl butyral, and cellophane.

This film base material is pre-sputtered on its surface.
Etching treatment or undercoating treatment such as corona discharge, flame, ultraviolet irradiation, electron beam irradiation, chemical conversion, oxidation, etc. may be performed to improve the adhesion of the conductive layer provided thereon to the base material. Before providing the conductive layer, dust removal and cleaning may be performed by solvent cleaning, ultrasonic cleaning, etc., as necessary.

The transparent conductive layer provided on this film base material is usually a metal oxide such as indium oxide, tin oxide, a mixture of indium oxide and tin oxide (hereinafter referred to as ITO), or a mixture of tin oxide and antimony oxide. Although ITO is used, ITO is particularly preferred in terms of conductivity and transparency. These conductive layers can be formed by employing known thin film forming techniques such as vacuum evaporation, sputtering, and ion blasting.

The thickness of the transparent conductive layer is preferably 50 Å or more; if it is thinner than this, it becomes an island-like film, and it becomes a continuous film with good conductivity and a surface resistance of 103 Ω/layer or less. The effect of improving moisture permeability cannot be expected, and on the other hand, if it becomes too thick, it will cause a decrease in transparency and moisture permeability resistance due to the occurrence of cracks, so a particularly suitable thickness is about 100 to 4,000 people. It is better to make it happen.

Examples of the metal or metal oxide layer that can be provided on such a conductive layer include indium, tin, cadmium,
Zinc, titanium, antimony, aluminum, tungsten, molybdenum, chromium, tantalum, nickel, platinum,
Metal layers made of one or more metals selected from gold, silver, copper, palladium, etc., titanium oxide, chromium oxide, magnesium oxide, zirconium oxide, aluminum oxide, zinc oxide, tantalum oxide, barium titanate, etc. Examples include oxide layers made of metal oxides or mixtures thereof.

These "metal layers and metal oxide layers can be formed by the same method as the conductive layer described above. The thickness of these layers is determined so that the light transmittance and sheet resistance are sufficiently satisfied, and the adhesion with the light emitting layer is maintained. In order to effectively prevent uneven light emission during operation, it is usually preferable that the former metal layer has a discoloration thickness of about 20 to 200 layers, and the post-discoloration metal oxide layer has a discoloration thickness of about 20 to 2,000 layers.

Other metal oxide layers that can be provided on the conductive layer include a discolored silicon oxide layer, which typically has a thickness of about 20 to 2,000 layers. Such an oxide layer provides good adhesion to the adhesive layer in addition to the adhesion to the light-emitting layer, which further improves the sealing performance and greatly contributes to extending the life of the EL device. can contribute. Such a silicon oxide layer can be formed in the same manner as the conductive layer described above, for example, by using metal silicon or SiO as the deposition material and depositing them in an oxygen atmosphere, or by depositing them in an oxygen atmosphere as the deposition material. It can be formed by using a method such as vapor deposition in a vacuum.

The adhesive layer usually provided on the transparent conductive layer or the metal or metal oxide layer is a transparent pressure-sensitive adhesive or a transparent heat-sensitive adhesive. These adhesives may be provided only on the portions that require adhesion to the aluminum substrate, that is, on the peripheral edges of each layer, or may be provided on the entire surface of each layer, if necessary.

The above-mentioned pressure-sensitive adhesive may be used without particular limitation as long as it has transparency, but acrylic adhesives, silicone adhesives, rubber adhesives, etc. are preferably used. The elastic modulus of these pressure sensitive adhesives is l x 1
It is desirable that the thickness be in the range of 0' to 1 x 10' dyne/cIil and the thickness should be 2 μm or more, usually in the range of 5 to 500 μm. If the elastic modulus is too small, there is a risk that it will protrude to the side surface after adhesion, and if it is too large, the hardness will increase and the adhesive workability and sealing performance will be likely to be impaired. Furthermore, if the thickness is too thin, the sealing properties will be poor, and if it is too thick, the transparency will be reduced, making it difficult to obtain good results in terms of adhesive workability and cost.

Examples of the heat-sensitive adhesive include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene ionomer resin. These adhesives may be provided by dry laminating a film-like material prepared in advance, or may be provided by an extrusion lamination method in which a film is melt-extruded. As in the case of the pressure-sensitive adhesive described above, the thickness is desirably 2 μm or more, usually in the range of 5 to 500 μm.

FIG. 1 shows an example of an EL light emitting device of the present invention manufactured using the transparent conductive moisture permeable film having the above structure.

In the figure, 1 is an aluminum substrate having a green-proofing layer 2 on the back side, 3 is a transparent film having the above structure, which has a transparent conductive layer 5 on a transparent film base 4, and a metal or metal oxide layer 6 thereon. It is a conductive moisture permeable film. this film 3
is placed facing the substrate 1 with the conductive layer 5 and the metal or metal oxide layer 6 inside, and is adhesively held to the substrate 1 by an adhesive layer 7 provided in advance on the periphery thereof. Inside, an insulating layer 8 on the substrate l side and a light emitting layer 9 on the film 3 side are laminated and sealed.

Note that 10 is an electrode terminal provided on the aluminum substrate l side, and 1) is an electrode terminal provided on the film 3 side.

This EL light emitting device is manufactured by forming an insulating layer 8 on an aluminum substrate 1 having an insulating layer 2 made of polyethylene terephthalate or polyethylene with a thickness of about 12 μm, and applying an adhesive layer 7 on the periphery. A light-emitting layer 9 is formed on the side of the transparent conductive layer 5 and the metal or metal oxide layer 6 thereon of the transparent conductive moisture-permeable film 3 provided, and the insulating layer 8 and the light-emitting layer 9 face each other. What is necessary is just to overlap|superpose them like this and adhesively seal with the adhesive layer 7.

The insulating layer 8 and the light-emitting layer 9 can be formed according to a conventionally known method. For example, the insulating layer 8 is formed by using a paint in which a known insulating material such as barium titanate powder is dispersed in an organic solvent solution of cyanoethyl pullulan. , thickness after drying is 5-1
00 μm and heat and dry. In addition, in the light emitting layer 9, a paint obtained by dispersing various known phosphor powders in an organic solvent solution similar to the above was used, and the thickness after drying was 5 to 1.
00 μm, heat-dried, and then vacuum-dried if necessary.

In such an EL light emitting device, since the transparent conductive moisture permeable film 3 serves both as the conductive substrate and the moisture permeable film of the conventional EL light emitting device, the thickness of the entire device becomes thinner. , and the manufacturing process and manufacturing cost thereof are reduced. Furthermore, the film 3 has conductivity and does not attract or mix in foreign matter or dust due to charging, so there is no risk of problems of poor sealing or poor appearance. In addition, since it is possible to select and use the film 3 made of various materials that reduce the difference in thermal shrinkage rate between the film 3 and the aluminum substrate 1, the problem of warping that occurs in conventional EL light emitting devices can be avoided. Does not occur in particular.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reduce the manufacturing process and manufacturing cost, and to make the entire device thinner, and there is no sealing failure or appearance failure due to charging, and there is no warping due to heat shrinkage. It is possible to provide an EL light emitting device that does not cause the occurrence of .

〔Example〕

Next, examples of the present invention will be described in more detail.

Example 1 The surface of a transparent polyethylene terephthalate film (hereinafter referred to as PET film) with a thickness of 75 μm was coated with 4×10-
'In an atmosphere of Torr, discharge processing amount 3W・sec/c1)
High frequency sputter etching treatment was performed.

Thereafter, indium-tin (weight ratio 9:1
) A transparent conductive layer of ITO with a thickness of about 1,000 nm was formed by reactive sputtering using an alloy. The surface resistance of this film was 100Ω/hole, and the light transmittance was 77%.

Then, 2~
A transparent dielectric layer made of silicon oxide having a thickness of approximately 900 nm was formed by vacuum evaporation of a stow at a vacuum level of 4×10-' Torr. The surface resistance of this film was 1) 0Ω/hole, and the light transmittance was 91%. Further, the heat shrinkage rate of this film was 0.2% at 150° C. for 30 minutes.

Next, the entire periphery on the dielectric layer (5 days from the periphery)
After forming a polyethylene heat-sensitive adhesive layer with a thickness of 50 μm to obtain a transparent conductive moisture-permeable film, a 30% by weight acetone of cyanoethyl pullulan was applied to the center of the film above the dielectric layer. Apply a paint containing phosphor powder (something that emits blue-green light) dispersed in a solution.
Dry at 120°C for 30 minutes, then dry at 120°C, lXl0
-"'f o r r atmosphere for 6 hours to form a light-emitting layer with a thickness of 40 μm.

On the other hand, one side is insulated with PET film and the thickness is 2
A paint prepared by dispersing barium titanate powder in a 30% by weight acetone solution of cyanoethyl pullulan (the weight ratio of barium titanate powder and cyanoethyl pullulan is 1:l) is applied to the aluminum surface of a 00 μm aluminum foil.
It was heated at 20° C. for 60 minutes to form an insulating layer with a thickness of 40 μm.

Next, the above-mentioned transparent conductive moisture-permeable film and the above-mentioned aluminum foil were stacked so that the insulating layer and the light-emitting layer faced each other, and they were adhesively bonded through a roll laminator heated to 160°C, as shown in Fig. 1. An EL light emitting device with a total structure thickness of approximately 370 μm was fabricated. This device shows no warping at all, and there is no foreign matter or dust attached to it due to charging.
It had a good appearance, excellent sealing properties, and a long life.

In addition, when producing the above EL light emitting device, we installed a polyamide water-trapping film with a thickness of about 100 μm between the insulating layer and the aluminum electrode, and found that the sealing properties were further improved and the lifespan was longer. An EL light emitting device was successfully manufactured.

Comparative Example 1 An insulating layer having a thickness of 40 μm as in Example 1 was formed on the aluminum surface of the same aluminum foil as in Example 1, one side of which had been subjected to insulation treatment. In addition, transparent PE with a thickness of 75 μm
A light-emitting layer having a thickness of 40 μm similar to that in Example 1 was formed on the conductive layer of a conductive substrate having a transparent conductive layer made of ITO having a thickness of approximately 400 μm provided on one side of a T film.

Next, the aluminum foil and the conductive substrate were stacked on top of each other so that the insulating layer and the light emitting layer faced each other, and bonded together through a roll laminator heated to 160°C. After that, a moisture-permeable film (heat-shrinkable at 150°C for 30 minutes) was prepared, in which an adhesive layer made of a polyethylene heat-sensitive adhesive with a thickness of 50 μm was provided on one side of a polychlorotrifluoroethylene film with a thickness of 150 μm. 2.5%), cover the above bonded body from the conductive substrate side, and cover the entire periphery (5 areas from the periphery) on the aluminum foil.
Pressure was applied for 5 minutes at 50° C. and 30 kg/− to fuse and bond, thereby producing an EL light emitting device having the structure shown in FIG. 2.

This EL light-emitting device had a total thickness of approximately 500 μm, and curls were observed. In addition, adhesion of foreign matter and dust due to charging was observed, resulting in poor appearance and poor sealing performance. Moreover, compared to Example 1, there were problems in that the manufacturing process was complicated and the manufacturing cost was considerably high.

Comparative Example 2 A bonded body of an aluminum foil having an insulating layer and a conductive substrate having a light-emitting layer, which was produced in the same manner as in Comparative Example 1, was used, and the whole was used as the moisture-permeable film used in Comparative Example 1. Covered with two sheets, the entire periphery (5fi area from the periphery)
5 at 150℃ and 30kg/cd.
Pressure was applied for a minute and fusion was performed to produce an EL light emitting device having the structure shown in FIG.

This EL light emitting device is extremely thick, with a total thickness of approximately 700 μm.
In addition, adhesion of foreign matter and dust due to charging was observed, resulting in poor appearance and poor sealing performance. Moreover, compared to Example 1 as well as Comparative Example 1, there was a problem that the manufacturing process was complicated and the manufacturing cost was higher.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the EL light emitting device of the present invention;
FIGS. 2 and 3 are cross-sectional views showing two examples of conventional EL light emitting devices. DESCRIPTION OF SYMBOLS 1... Aluminum substrate, 2... Everlasting green treatment layer, 3.
...Transparent conductive moisture permeable film, 4...Transparent film base material, 5...Transparent conductive layer, 6...Metal or metal oxide layer, 7...Adhesive layer, 8 ...Insulating layer, 9
...Light emitting layer

Claims (2)

[Claims] (1) A transparent conductive moisture-permeable film, which is a transparent conductive layer provided on a transparent film base material, is placed facing an aluminum substrate having an anti-green treatment layer on its back side, with the conductive layer inside. , the periphery of which is adhered and held to the substrate with an adhesive, and an insulating layer on the substrate side and a light emitting layer on the film side are laminated and sealed inside the EL.
Light emitting device. (2) A claim in which the transparent conductive moisture permeable film has a transparent metal or metal oxide layer on the transparent conductive layer
1).The EL light emitting device according to item 1).