JPH03203193A - Thin film electroluminescent panel - Google Patents

Abstract

PURPOSE:To decrease the cost and realize a high moisture resistance reliability by providing a black adhesive tape, a moisture absorbing layer consisting of polymer including moisture absorbing powders, and a moisture preventing sheet of organic resin film laminated on both surfaces of a metal foil on an electroluminescent element. CONSTITUTION:A thin film electroluminescent element 1 is formed on a transparent substrate 2, and a both-sided adhesive tape 16, a moisture absorbing sheet 17, and a moisture preventing sheet 21 are applied in order in dry N2 gas or air. The peripheral parts of the moisture preventing sheet 21 are applied on the substrate 2 by epoxy resin 9 in such a way as to form a space 22 for including dry N2 gas or air between the moisture preventing sheet 21 and the electroluminescent element 1. The adhesive tape 16 consists of a base material 14 of black polyester film, and silicone binding agent 13, 15 provided on both surfaces of the base material 14. The moisture sheet 17 is composed of powders of moisture absorbing agent such as silica fine powders and synthetic zeolite scattered in an organic polymer sheet. The moisture preventing sheet 21 has a lamination structure of a metal foil 19 and polyester or other organic resin film 18, 20 on both surfaces of it.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industry> Second Application The present invention relates to a thin film EL (electroluminescence) panel used in display devices such as personal combi coaters and word processors.

<Prior Art> There is a conventional thin film EL panel as shown in FIG. This thin film EL panel (a lower transparent electrode 3, a lower insulating layer 4, a light emitting layer 5 arranged in parallel in a band shape on a glass substrate 2, a two-part insulating layer 6, - the lower transparent electrode) Upper electrodes 7 are arranged in parallel at right angles in the form of fingers. In addition, in order to deal with moisture and ensure high reliability, silica gel powder and black insulating powder are inserted through the holes 10 in the backing glass 8. Dispersed silicone oil is sealed in the space 11 between the EL element 1 and the backing glass 8, and the hole 10 is sealed with a seal 12. In this way, moisture absorption performance is provided, and high contrast is achieved by making the background color of the display surface black when viewed from the substrate 2 side.

Furthermore, unlike the above-mentioned thin film EL panel, there is also known a structure in which a laminate film is used to prevent moisture from entering the EL element (Japanese Patent Application Laid-Open No. 61290693).

<Problems to be Solved by the Invention> However, of the above two types of thin film EL panels, the former has a backing glass 8, silica gel powder, and black insulating powder dispersed therein (i.e., it is provided on a silicon oil-based substrate). a black or nearly black adhesive tape closely adhered onto the bipedal thin film EL element, a hygroscopic layer containing hygroscopic powder and provided on the adhesive tape, and a metal It consists of a foil and an organic resin film provided on both sides of the metal foil, and is characterized by comprising a moisture-proof sheet covering the thin-film EL element, adhesive tape, and moisture-absorbing layer.

Further, it is preferable that the above-mentioned adhesive tape comprises a base material made of a black or substantially black polyester film, and a silicone adhesive provided on both or one side of this base material.

Also, the ``biped moisture absorbing layer'' is made by dispersing moisture absorbent powder into an organic polymer sheet? It is desirable that the sheet be a moisture absorbing sheet.

Further, it is preferable that the moisture absorbing layer is a moisture absorbent powder adhered to the upper surface of the biped adhesive tape.

<Function> Materials and 1. Since adhesive tape, a moisture absorbing layer, and a moisture proof sheet are used in the process, the price of the backing glass and silicone oil is high. There is a problem in that it is not possible to reduce the cost because it requires a process and a lot of time.

In addition, because of the thickness and weight of the backing glass 8 itself, there is a limit to how thin and lightweight this type of thin film EL panel can be made.

Ichiriki, for the latter type, what are the specific pronouns regarding the A/A function to ensure high reliability? , not C,
Furthermore, no consideration is given to increasing contrast.

Therefore, the purpose of this invention is to reduce costs by reducing material costs and simplifying processes, as well as to achieve high moisture resistance and reliability.
Lighter thin film E1. The purpose is to provide panels.

Means for Solving the Problems> In order to achieve the above object, the thin film E1 and panel of the present invention have a light-transmitting substrate and a light-emitting layer and an insulating layer between two opposing electrode layers. , compared to the conventional case using the above-mentioned transparent illumination (7), the material cost is lower.In terms of process,
Adhesive tape with a moisture-absorbing layer applied in advance is attached to the EL element.
or ET, apply adhesive tape on the element (=T Ll, then apply a moisture absorption layer to this adhesive tape) (J, then cover this -11 with a moisture-proof sheet ('3 is fine). This simplifies the process by eliminating the need for the vacuum process and time required when sealing conventional silicone oil.This results in advantages in terms of materials and processes, and costs.
・Decreases.

Moreover, since no backing glass is used, the panel is thinner and lighter.

Furthermore, since the thin film EL element is covered with a moisture-proof sheet having metal foil, moisture-proof reliability is ensured.

Even if moisture gets inside the moisture-proof notebook due to continued use, it will be absorbed by the moisture-absorbing layer, so
■Deterioration of the characteristics of the 7-chord is prevented.

In addition, place a black or nearly black adhesive tape on the EL and the saw that is attached to the element, as seen from the side of the transparent substrate.
Sometimes the background color of the display screen becomes black or almost black,
Improves contrast. Moreover, since the two-legged adhesive tape is closely attached to the EL element, the display surface does not appear uneven, and the appearance is improved and the display quality is improved.

In addition, when the above-mentioned adhesive tape is composed of a polyester film and a silicone adhesive provided on both sides or one side of this base material, the polyester film has low moisture permeability and the silicone adhesive has water resistance. , moisture resistance reliability is further improved.

In addition, when the moisture absorption layer is a moisture absorption sheet formed by dispersing moisture absorbent powder in an organic polymer sheet, an adhesive tape,
It can be manufactured simply by laminating a moisture-absorbing sheet and a moisture-proof sheet, which further simplifies the process and lowers the J-strength.

In addition, the moisture absorbing layer can be manufactured by simply pasting the moisture absorbent powder-coated adhesive tape and the moisture-proof sheet together on the top surface of the adhesive tape (= 1 piece of moisture absorbent powder), which further simplifies the process. , reducing costs.

<Example> Moisture absorbent sheet 17 is composed of a hygroscopic agent powder such as silica (SiOp) fine powder, 1 synthetic zeolite powder (trade name: Morekico, Larsieve), etc., dispersed in an organic polymer sheet. The sheet may be in the form of a film, a nonwoven fabric, or a woven fabric. The above moisture-proof sheet 21
1. has a laminated structure in which both sides of a metal foil 19 made of 5 to 50 μm thick A (or the like) are sandwiched between 5 to 50 μm thick organic resin films 18 and 20 such as polyester.

Note that the organic resin films 18 and 20 may be made of the same feed or may be made of different materials. The two-legged EL element I9 double-sided adhesive tape 16 and moisture-absorbing sheet 17 are approximately the same size, but the moisture-proof sheet 21 is slightly larger in size to cover this.

This thin film EL panel is manufactured as follows. First, after forming the thin film EL element 1 on the transparent substrate 2, the temperature is raised to about 200° C. or higher in vacuum to degas the thin film EL element 1. After removing as much residual moisture as possible, the thin film EL panel of the present invention is described in detail with reference to the illustrated embodiment.

As shown in FIG. 16 and
A moisture absorption layer (moisture absorption sheet pasted on the adhesive tape 16 of 7 levers) 17, and the thin film EL element 1. A moisture-proof sheet 21 covering the adhesive tape 16 and the moisture-absorbing sheet 17 is provided. The light-transmitting substrate 2 and the thin film EL element 1 are the same as those in the conventional example shown in FIG. 4, and the same reference numerals are given to each component and the explanation thereof will be omitted. The double-sided adhesive tape 16 includes a base material 14 made of a black or substantially black polyester film, and a silicone adhesive 13.15 provided on both sides of this base $i1.4. Since the base material 14 is made of a polyester film, it has excellent heat resistance, cold resistance, and strength, and absorbs little water. Since the adhesives 13 and 1.5 are silicon-based, they have appropriate adhesive strength and are excellent in heat resistance, corona resistance, and water resistance. - Note 11 Quickly attach the moisture-absorbing sheet 17 and the moisture-proof sheet 21 one after another. At that time, a space 22 containing dry N, gas, or dry air is formed between the moisture-proof sheet 21 and the EL element 1, and the peripheral part of the moisture-proof sheet 21 is covered with Evoquin resin on the transparent substrate 2. Glue according to 9. In addition, the first
As shown in the figure, a part of the electrode 7-h is attached to the lower transparent electrode 3 or is extended between the two transparent substrates.
There are also places where it is glued.

In this case, double-sided adhesive tape 16. moisture absorption sea)
- Since the moisture-proof sheet 17 and the moisture-proof sheet 21 are used as the A1s+, the material price can be lowered compared to the conventional case using backing glass and solicon oil.

Further, the two steps and time required to create a vacuum when sealing conventional solicon oil can be omitted, and the process can be simplified.

Therefore, it is advantageous in terms of materials and processes, and costs can be reduced. What's more, it doesn't use glass on the back? <Nell Hirog (II・e: Can you change the letter “i”? Also, metal foil 1 for thin film EL element Ikawa)
9, it is possible to ensure moisture resistance reliability. The moisture-proofing effect is achieved mainly because the metal foil 19 is moisture-impermeable. Organic resin films such as polyester 18.20 are mainly
Surface protection of bipedal metal foil 19, this metal foil, and EL element 1
It is preferably a material with low moisture permeability, although it serves as an electrical insulator between the two. As described above, even if the EL element 1 is sealed in dry N2 gas or dry air, a small amount of moisture may be trapped therein. Furthermore, moisture may enter the inside of the moisture-proof sheet 21 due to continuous use over a long period of time. Even in such a case, the humidity-resistance reliability can be further improved because the moisture-absorbing sheet 16 absorbs moisture and the base material 14 of the adhesive tape 16 is made of polyester film and the adhesive 13.15 is silicone-based. ing.

When this thin-film EL panel was actually accelerated tested in a heated and humidified atmosphere, the results showed that the life span for deterioration of display quality at room temperature was estimated to be over 50,000 hours, indicating that it is sufficiently durable for actual use. I understand. (1) Furthermore, although this embodiment has been described with reference to the case where the EL element 1 is of a dot matrix type, it is of course not limited to this, and may be of a segment type.

<Effects of the Invention> As is clear from the above, the thin film EL panel of the present invention has a light-transmitting substrate and a light-emitting layer and an insulating layer between two opposing electrode layers, - Installation on: a thin-film EL element, a black or nearly black adhesive tape closely pasted on the thin-film EL element, and a hygroscopic powder provided on the adhesive tape. It is composed of a moisture absorbing layer, a metal foil, and an organic resin film provided on both sides of the metal foil, and is equipped with a moisture-proof sheet covering the thin film EL element, adhesive tape, and moisture absorbing layer, so that the backing glass and silicone oil can be removed. Compared to conventional thin-film EL panels, it is possible to reduce costs in terms of materials and processes, and at the same time, achieves high moisture resistance reliability, increases contrast and improves display quality14, and is thinner. -Can be made lighter.

In addition, since this thin film EL panel is provided with a black or substantially black double-sided adhesive tape 16 on the EL element 1, the background color of the display section can be made black or substantially black to increase contrast. Furthermore, since the EL element 1 and the double-sided tape 16 are brought into close contact with each other, if there is a gap between them, the display surface will be prevented from appearing uneven, improving the appearance and display quality. be able to.

Note that instead of the double-sided adhesive tape 16, as shown in FIG. 2, single-sided adhesive tape 23 and 1. But it's okay. In this case, the adhesive 13 is brought into close contact with the EL element l side.

Further, instead of the moisture absorbing sheet 17, as shown in FIG. 3, a moisture absorbing agent powder 24 such as Norica fine powder and 9-merized zeolite powder may be provided as a moisture absorbing layer. In this case, during manufacturing, the double-sided tape I6 with the moisture absorbent powder 24 attached to the adhesive 15 side may be pasted on the EL element 1, or the double-sided tape 16 may be pasted on the adhesive 15 side. After pasting it on element 1 (=t l:], apply hygroscopic powder 24 in step A).
Arrival (2 is also good.

2. In addition, when the above-mentioned adhesive tape (Y) is composed of a base H made of a black or substantially black polyester film and a silicone adhesive provided on both sides or one side of this base material, the moisture resistance is further improved. be able to.

In addition, when the moisture absorption layer is formed by dispersing moisture absorbent powder in an organic polymer notebook, the process can be further simplified and costs can be reduced.

Further, when the moisture absorbing layer is a moisture absorbent powder attached to the upper surface of the adhesive tape, the second step can be further simplified and costs can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, FIG. 2, and FIG. 3 are sectional views showing an embodiment of the thin film EL panel of the present invention, and FIG. 4 is a sectional view showing a conventional thin film EL panel. 1. Thin film EL element, 2. Transparent substrate, 3. Lower transparent electrode, 4. Lower insulating layer, 5. Light guide body, 6. Upper insulating F1.71-0 electric rod, 9. Epoxy resin, 13
．． 15.Adhesive, 14.Polyester film, 16.Double-sided adhesive tape, 17.Moisture absorption sheet, 18.2
0. Organic resin film, 19. Metal foil, 21.. Moisture-proof sheet, 22.. Space, 23.. Single-sided adhesive tape, 24.. Moisture absorbent powder. Patent Applicant Sharp Corporation Agent Patent Attorney Haka Aoyama 1 person】5

Claims (4)

[Claims] (1) A thin film EL element comprising a light transmitting substrate, a light emitting layer and an insulating layer between two opposing electrode layers, a thin film EL element provided on the light transmitting substrate, and a thin film EL element provided on the thin film EL element. A black or nearly black adhesive tape adhered tightly, a moisture absorbing layer containing hygroscopic powder and provided on the adhesive tape, a metal foil and an organic resin film provided on both sides of the metal foil. A thin film EL panel comprising the above thin film EL element, an adhesive tape, and a moisture-proof sheet covering a moisture absorbing layer. (2) The adhesive tape according to claim 1, wherein the adhesive tape comprises a base material made of a black or substantially black polyester film, and a silicone adhesive provided on both or one side of the base material. Thin film EL panel. (3) The thin film EL panel according to claim 1, wherein the moisture absorbing layer is a moisture absorbing sheet formed by dispersing moisture absorbent powder in an organic polymer sheet. (4) The thin film EL panel according to claim 1, wherein the moisture absorbing layer is a moisture absorbent powder attached to the upper surface of the adhesive tape.