JP2773625B2 - Electroluminescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroluminescent lamp, and more particularly to a thin electroluminescent lamp which does not use a conventional outer film.

[0002]

2. Description of the Related Art As shown in FIG. 5 (a), a conventional electroluminescent lamp has a laminate in which a light emitting layer 52 and a reflective insulating layer 53 are sandwiched between a transparent electrode 51 and a back electrode 54 such as an Al foil. And a current collecting band 51a made of Ag paste or the like is formed at a peripheral position of the transparent electrode, and the leads 55 and 56 are taken out from the current collecting band 51a and the back electrode 54 to the outside. A structure in which the body is hermetically sealed from above and below by thermocompression bonding with outer films 57, 57 for moisture-proof protection is generally used.

In such a conventional electroluminescent lamp 50, the light-emitting layer 52 and the reflective insulating layer 53 are heated and pressurized to form
In some cases, insulation is reduced or short-circuiting between the electrodes is caused by, for example, being pressed by 1a and extremely thinning at the corresponding portion, or the current-collecting band material penetrating a pinhole in the light emitting layer or the reflective insulating layer.

In order to solve such a problem, as shown in FIG. 5B, in an electroluminescent lamp having the above-mentioned structure (leads are not shown), a current collecting band 51a and a back electrode 5a are formed.
Japanese Patent Application Laid-Open No. 58-93194 discloses an electroluminescent lamp 60 in which an insulating film 58 is formed at a position where a current collecting band is formed.

[0005]

The above-mentioned conventional electroluminescent lamp has an advantage that the insulating property can be improved by the interposition of an insulating film, but usually, a lead made of phosphor bronze or the like having a thickness of about 100 μm is laminated on each electrode. Connect, thickness 100μ from top and bottom
Since the film is sandwiched and sealed with an outer film of about m in fluororesin or the like, the entire thickness is as thick as about 1 mm (particularly, the lead connection portion), and there is a problem that thinning is extremely difficult with this structure. .

In particular, in recent years, ultra-small liquid crystal display devices have been used in small portable electronic devices such as portable watches and pagers, and ultra-thin and ultra-small electroluminescent as a backlight. Lights are needed. Conventionally structured electroluminescent lamps are not suitable for such applications.

On the other hand, there is provided an electroluminescent lamp in which a light emitting layer, a reflective insulating layer, a back electrode such as a carbon paste and the like are sequentially formed on a transparent conductive film by printing. The contact resistance of the power supply unit when connecting to a power supply or the like is high, and there is a problem in the reliability of the electrical connection.

Therefore, the present invention has been made in view of the above-mentioned problems of the conventional electroluminescent lamp.
An object of the present invention is to provide an electroluminescent lamp in which the insulation between the electrodes is improved, the thickness is reduced, the reliability of the electrical connection of the power supply unit is improved, and unnecessary light emission at the position of the current collecting band is prevented.

[0009]

An electroluminescent lamp according to the present invention comprises:
A light emitting layer using a moisture-proof phosphor and a reflective insulating layer are sandwiched between a transparent conductive film having a power supply portion made of a conductive paste on a transparent electrode and a back electrode made of carbon, and a back electrode. A power supply portion made of a low-resistance conductive paste is formed outside the substrate, and between the back electrode and the transparent electrode, that is, between the transparent electrode and the light emitting layer, or between the light emitting layer and the reflective insulating layer, or with the reflective insulating layer. A low dielectric constant insulating film having a relative dielectric constant of 5 or less is interposed and formed at a position corresponding to a power supply portion forming position between the back electrodes.

[0010]

[Action] By Rukoto improved by the contact reliability between the back electrode made of carbon paste and feed line to form a feeding portion by silver was connected to overlap the electrode
Moisture by thinner and the need for conventional lead and reduced insulation between the electrodes by migration of silver is a material feeding part, a short improves the reliability by preventing the insulating coating, to moisture-proof coating
A thinner electroluminescent lamp can be provided at a low cost by using a phosphor with improved performance and eliminating the need for a moisture-proof outer skin film. In addition, unnecessary light emission at the power supply portion forming position can be prevented by the insulating film having a low dielectric constant.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and manufacturing method of an electroluminescent lamp according to a first embodiment of the present invention will be described with reference to FIGS. The electroluminescent lamp 8 of the present invention has the structure shown in the perspective view of FIG. As shown in the plan view of the manufacturing process in FIG. 2, first, as shown in FIG. 2A, for example, as shown in FIG. An insulating paste made of an epoxy resin or the like having a dielectric constant of about 2 is selectively printed on the electrode 1 by screen printing to form an insulating film 2 having a thickness of 10 to 30 μm. Next, as shown in FIGS. 2 (b) and 2 (c), a phosphor obtained by coating a phosphor obtained by activating zinc sulfide with copper in a moisture-proof coating (for example,
Light-emitting layer 3 in which SYLVANIA phosphor (Type 20) is dispersed in resin
A reflective insulating layer 4 in which an insulating material such as barium titanate is dispersed in a resin having a thickness of about 30 to 50 μm.
It is formed by screen printing in order of about m. In this case, the insulating coating 2 is selectively formed in a pattern that covers at least a portion of the back electrode 5 corresponding to the power supply portion 7 and avoids the power supply region 1a on the transparent electrode side. Next, as shown in FIG. 2 (d), the back electrode 5 made of carbon paste is screen-printed to a size slightly smaller than the reflective insulating layer 4 and the light emitting layer 3 to avoid the power supply region 1a on the transparent electrode side. A-
A pattern with a thickness of 1 that overlaps the extension of A '
Selectively form about 0 to 30 μm. Next, as shown in FIG. 2E, the power supply portions 6 and 7 made of a low-resistance silver paste are simultaneously applied to the power supply region 1a on the transparent electrode 1 side and the power supply region 5a on the back electrode 5 side to a thickness of about 10 to 30 μm. As shown in FIG. 2 (f), the power supply sections 6 and 7 are formed by printing and forming an insulating protective layer 8 having a thickness of about 10 to 30 [mu] m.
The electroluminescent lamp 9 is formed by covering the other portions. The electroluminescent lamp 9 formed in this manner is very thin because all processes are formed by printing, and has a total thickness of 150 to 350 μm.
About 1/6 to 1/3 of the thickness of the conventional electroluminescent lamp
Becomes thin. Further, since the power supply portion is formed of silver having good conductivity, the reliability of the contact with the external power supply line is improved, and the insulation between the electrodes is reduced due to migration of silver as the material of the power supply portion 7 and a short circuit is prevented. This can be prevented by the insulating film, and since the insulating film 2 is made of a material having a low dielectric constant, the voltage drop of the insulating film portion is large, the voltage of the light emitting layer is reduced, and the power supply portion forming position (for example, It is possible to provide a thin, highly reliable, and low-cost electroluminescent lamp in which unnecessary light emission in 5a) is prevented.

In this embodiment, an epoxy resin is used for the insulating coating 2, but any material such as a melamine resin or a polyethylene resin may be used as long as the material has a dielectric constant of 5 or less and can be selectively printed. Similar effects can be obtained by interposing an insulating coating between the light emitting layer and the reflective insulating layer.

Next, a second embodiment of the present invention will be described.

In the first embodiment, the insulating film 2 is interposed between the transparent electrode 1 and the light emitting layer 3, but if the insulating film 2 is formed thick at this time, the particle size of the phosphor forming the light emitting layer 3 is reduced. Is 2
Since it is as large as 0 to 30 μm, the light emitting layer 3 cannot follow the step between the insulating film 2 and the transparent electrode 1 as shown in FIG. Therefore, in the second embodiment of the present invention, as shown in the perspective view of FIG.
And the back electrode 15. The manufacturing method is
In the same manner as in the first embodiment, a light-emitting layer 12 in which a phosphor having moisture-proof coating on a transparent electrode 11 is dispersed in a resin and a reflective insulating layer 13 in which an insulator such as barium titanate is dispersed in the resin are sequentially screen-printed. It is selectively formed in a pattern shape avoiding the power supply region 11a on the transparent electrode side. Next, an insulating paste made of an epoxy resin or the like is selectively printed by screen printing at least on the reflective insulating layer 13 at a position corresponding to the power supply section 17 on the back electrode side, thereby forming an insulating film 14. Next, the back electrode 15 made of carbon paste is screen-printed with a dimension slightly smaller than the reflective insulating layer 13 and the light emitting layer 12 to avoid the power supply region 11a on the transparent electrode side, and to obtain a linear light emitting region. Is selectively formed in a pattern shape that overlaps with the extended straight line of the one end portion CC ′.
Next, the power supply region 11a on the transparent electrode 11 side and the back surface electrode 15
The power supply sections 16 and 17 made of low-resistance silver paste or the like are simultaneously formed in the power supply area 15a on the side by printing, respectively, and further over the power supply sections 16 and 17 with an insulating protective layer 18 (not shown) to secure insulation. The electroluminescent lamp 19 is formed by covering the other portions. In the present embodiment, the carbon constituting the back electrode 15 has a small particle size of 1 to 10 μm and can be printed accurately, so that it can follow the steps of the insulating film 14, and a non-light emitting portion is formed in a necessary light emitting region. Does not occur.

In the above embodiment, the lead and the outer film in the conventional electroluminescent lamp are not required, so that it is possible to make it ultra-thin. In the case where a thin metal foil is led out as a lead, a light emitting layer, a reflective insulating layer, a back surface electrode, and the like are formed especially in the power supply regions 1a and 11a of the transparent electrode, and the power supply portions 6 and 1 are formed.
Although a metal foil lead may be sandwiched between the light emitting layers 6 and the light emitting layers 3 and 12, the thickness is slightly increased.

[0016]

According to the present invention, the reliability of the contact between the back electrode made of carbon paste and the external power supply line is improved by forming the power supply portion made of silver, and
An insulation coating interposed between the transparent electrode and the back electrode prevents insulation deterioration between electrodes and short-circuit due to migration of the power supply portion by silver, and provides a highly reliable and low-cost thin electroluminescent lamp. In addition, unnecessary light emission at the power supply portion forming position can be prevented by the low dielectric constant insulating film.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electroluminescent lamp according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a manufacturing process of the electroluminescent lamp according to the first embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part showing a failure example of the electroluminescent lamp according to the first embodiment of the present invention.

FIG. 4 is a perspective view of an electroluminescent lamp according to a second embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a main part showing a conventional electroluminescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,11 Transparent electrode 2,14 Insulating coating 3,12 Light emitting layer 4,13 Reflective insulating layer 5,15 Back electrode 6,16 Transparent electrode side power supply part 7,17 Back electrode side power supply part 8,18 Insulation protection layer 9, 19 Electroluminescent lamp

Claims (6)

(57) [Claims] 1. A transparent conductive film in which a power supply portion made of a conductive paste is formed on a transparent electrode, a light emitting layer in which a moisture-proof coated phosphor is dispersed in a resin, and a reflective insulating layer in which a high dielectric substance is dispersed in the resin. And a laminate of a back electrode made of carbon paste, and a power supply part made of a conductive paste formed on the back electrode, and corresponding to a power supply part formation position between the back electrode and the transparent electrode. An electroluminescent lamp in which a low dielectric constant insulating film is interposed in some places. 2. The electric field according to claim 1, wherein the light emitting layer, the reflective insulating layer, and the back electrode are formed so as to avoid a power supply portion on the transparent electrode, and the power supply portion is exposed. Light emitting lamp. 3. The electroluminescent lamp according to claim 1, wherein said insulating film is formed between a transparent electrode and a light emitting layer. 4. The electroluminescent lamp according to claim 1, wherein said insulating film is formed between a light emitting layer and a reflective insulating film. 5. The electroluminescent lamp according to claim 1, wherein said insulating film is formed between a reflective insulating layer and a back electrode. 6. The electroluminescent lamp according to claim 1, wherein said insulating film has a dielectric constant of 5 or less.