JPH0935873A - El lamp and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EL lamp and a method for manufacturing the EL lamp wherein manufacture can be inexpensively performed with easy external connection of an electrode. SOLUTION: A transparent electrode layer 2, emitter layer 3, dielectric layer 4, back surface electrode layer 5, collector electrode layers 5a, 5b and an insulating coat layer 6 are formed to be printed by a prescribed pattern on an insulating transparent film 1. In conductive paste used for forming the transparent electrode layer 2, acicular power (A) and fine powder as oxidized indium tin conductive powder, (B) are set to (A):(B)=100:0 to 20:80, binder resin is (D) photocuring or heat curing, and total conductive powder is set to (C):(D)=45:55 to 95:5, so as to obtain an excellent EL lamp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL lamp used in an illuminating section of various electronic devices and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, small-sized IC drive inverters have been developed, and as a backlight for liquid crystal display units and switches of various electronic devices such as communication devices, video devices, and audio devices, they emit light thinly and in a plane. The demand for EL lamps is increasing.

Such a conventional dispersion type EL lamp is
As shown in the plan view of FIG. 6 and FIG. 7 which is a cross-sectional view taken along the line AB of FIG. 6, indium tin oxide is laminated on the entire upper surface of the insulating transparent film 1 such as a polyethylene terephthalate (PET) film by sputtering or the like to obtain a transparent conductive film. A film 12 is formed, and a high dielectric resin such as cyanoethyl pullulan or vinylidene fluoride rubber is dissolved in an organic solvent such as dimethylformamide or N-methylpyridone on the transparent conductive film 12 to disperse a luminous body such as zinc sulfide. The luminous body layer 3 thus formed is formed by pattern-printing by screen printing or the like and drying, and a high dielectric substance such as barium titanate is dispersed in a resin of the same type as the luminous body layer 3 by superposing on the luminous body layer 3. Pattern the dielectric layer 4, the back electrode layer 5 with a carbon resin paste or a silver resin paste, and the insulating coating layer 6 with an insulating paste. It was formed by laminating by drying and printing. For the collector electrode 5b on the transparent conductive film 12 side, a part of the transparent conductive film 12 is exposed from the light emitting layer 3, the dielectric layer 4, the back electrode layer 5, and the insulating coating layer 6 and a silver resin paste or the like is pattern-printed. Then, the current collecting electrode 5a on the back electrode layer 5 side was formed by exposing the end portion of the back electrode layer 5 from the insulating coat layer 6.

When the wiring of the collecting electrodes 5a and 5b is required to be long, a dielectric layer 4 is formed as shown in a cross-sectional view AB in FIG.
Since the high-dielectric resin used for the above has poor adhesion to the transparent conductive film 12, it was formed by separately providing the insulating film 13 made of epoxy resin or the like.

[0005]

However, in the above-mentioned conventional structure, the PE formed by sputtering the transparent conductive film 12 is used.
Since the T film is expensive, the collector electrode 5 of the EL lamp
When a and 5b are externally connected, if the collector electrode wiring is lengthened, there is a problem that a PET film with the transparent conductive film 12 is required in addition to the light emitting portion, which is expensive. In addition, connecting the EL lamp electrode to the printed circuit board or the like with an anisotropic conductive adhesive requires forming an additional insulating layer on the PET film with the transparent conductive film 12 by overall sputtering, etc. Since it became thick, heat conduction was poor and it was extremely difficult to adhere. Also, in case of connector connection, P
Since the transparent conductive film 12 is present on the entire circumference of the end surface of the ET film, there is a risk of short circuit, which is substantially difficult. Further, the method of removing the transparent conductive film 12 except the light emitting portion by etching in advance is more expensive. there were.

For these reasons, the above problems can be solved by pattern-printing the transparent electrode with a conductive paste having visible light transmittance. This conductive paste having visible light transmittance is disclosed in Japanese Patent Laid-Open No. 64-64- It is known and disclosed in Japanese Patent No. 10595 and Japanese Patent Application Laid-Open No. 63-10496. However, when a luminescent material or a dielectric is printed on a coating film of a conductive paste having such a visible light transmittance, dimethylformamide or a dimethylformamide in which a high dielectric resin used for the luminescent material or the dielectric is dissolved. A polar solvent such as N-methylpyridone causes a significant problem that the conductive performance is significantly deteriorated due to the high temperature during drying, and a new problem occurs in which light is emitted at all or only in the vicinity of the collecting electrode, which is a problem that cannot be realized. It was Therefore, even if it can be used as the back electrode layer 5, or the transparent electrode layer and the light emitting layer 3 are separately formed and then used for laminating and laminating, the light emitting layer 3, the dielectric layer, etc. This has a problem that it cannot be applied to a configuration in which the layers 4 and the like are printed in an overlapping manner.

The present invention solves such conventional problems,
It is an object of the present invention to provide an EL lamp which can be easily manufactured with a simple structure and can exhibit stable performance, and a manufacturing method thereof.

[0008]

In order to solve the above problems, the present invention provides a transparent electrode layer, a light emitting layer, a dielectric layer, a back electrode layer, a current collecting electrode, and an insulating coating layer on an insulating transparent film. The conductive paste used for forming the transparent electrode layer, which is formed by printing in a predetermined pattern, is obtained by dispersing a conductive powder having visible light transparency in an insulating resin or a resin solution in which the insulating resin is dissolved. The conductive powder having visible light transparency is indium tin oxide powder, the indium oxide powder is composed of acicular powder (A) and fine particle powder (B), and the weight ratio of (A) :( B) is 10.
0: 0 to 20:80, and the weight ratio (C) :( D) = 4 of the total conductive powder (C) and the insulating resin (D) to be dispersed.
It is set to 5:55 to 95: 5, and the insulating resin in which the conductive powder is dispersed is heat curable or photocurable.

[0009]

With this configuration, the print-type transparent electrode layer is stable without deterioration of the conductivity against overprinting of the light-emitting layer, the dielectric layer, etc., and the transparent conductive film formed by the conventional sputtering method is used. The brightness does not change. Moreover, the conductivity is stable even in a high temperature and high humidity environment, and the environment resistance reliability of brightness is also stable.

Furthermore, since the transparent electrode layer and the transparent electrode layer can be formed by pattern printing, the manufacturing equipment can be unified.
Even if the external connection part of the current collecting electrode is separated from the light emitting part, only the wiring of the current collecting electrode needs to be formed on the same insulating transparent film, and it can be manufactured at low cost.

Further, when the collector electrode is externally connected, an anisotropic conductive adhesive is externally connected to the connecting portion because there is no transparent conductive film or insulating film formed on the insulating transparent film at the connecting portion by conventional sputtering. By forming it on the collecting electrode and the insulating transparent film at the tip of the external connection part, connection to the printed circuit board becomes easy, and a reinforcing plate is formed on the back surface of the insulating transparent film at the tip of the external connection part. This makes it easier to connect with a connector.

[0012]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to FIGS.

A 75 μm polyethylene terephthalate (hereinafter referred to as PET) film is used as the insulating transparent film 1 on a heat-curable insulating resin (epoxy resin, oil-made shell # 828 and phenoxy resin, Toto Kasei YP-40).
Of 100 in an equal weight ratio, imidazole blocked isocyanate as a curing agent, G8 manufactured by Daiichi Kogyo Seiyaku
Indium oxide powder (SCP-X manufactured by Sumitomo Metal Mining Co., Ltd.) was added to 15 parts by weight of 009B) and dispersed in three rolls, and a transparent electrode paste whose viscosity was adjusted to 13 Pa with a solvent (isophorone) was used as a screen. Print 1
The transparent electrode layer 2 having a dry film thickness of 3 to 5 μm was patterned by drying at 55 ° C. for 15 minutes.

Thereafter, each of the following pastes was similarly applied on the transparent electrode layer 2 in a predetermined pattern. Luminous body layer 3;
A mixed solution of 70% by weight of cyanoethyl pullulan resin and 30% by weight of cyanoethyl polyvinyl alcohol resin (30% by weight of CR-M manufactured by Shin-Etsu Chemical Co., Ltd. in dimethylformamide).
50 g of dissolved substance, 2 g of imidazole blocked isocyanate (G8009B manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a curing agent, and a luminous body (TYP manufactured by Sylvania, USA)
A paste in which 100 g of E40) was dispersed by stirring, a dry film thickness of 35 μm. Dielectric layer 4; Vinylidene fluoride copolymer rubber solution (Dikin G902 manufactured by Daikin Industries, Ltd. dissolved in isophorone at 35% by weight) 53 g, dicumyl peroxide 0.02 g as a curing agent, BaTiO ₃ (manufactured by Kanto Chemical Co., Inc.) A paste in which 50 g of powder is dispersed by three rolls,
Dry film thickness 35 μm. Back electrode layer 5; conductive paste (DW-250H manufactured by Toyobo), dry film thickness 10 μm. Insulation coat layer 6; insulation paste (XB-804A manufactured by Fujikura Kasei), dry film thickness 30 μm.

FIG. 1 shows a plan view of the EL lamp thus produced, which is then overprinted and dried, and FIG. 2 is a sectional view taken along line AB of FIG. In this embodiment, the back electrode layer 5 and the collecting electrode 5a,
5b was integrally formed by pattern printing at the same time. When 100 V 400 Hz was applied to the collector electrodes 5a and 5b of this sample, the initial luminance was 74.8 Cd / m ² . This sample was left in a 90 ° -95% RH bath at 70 ° C and 40 ° C in a lit state to measure a decrease in luminance. As a result, a 50% luminance half-life was 300 hours in a 70 ° C bath, 40 ° C, 90-95%. % RH
It was 1000 hours in the tank.

Further, when the ratio of the acicular powder (A) constituting the indium oxide powder is less than 20%, the deterioration of the conductivity is large when the luminous layer 3 and the dielectric layer 4 are overprinted and dried, and the brightness is lowered. However, when left in a high temperature and high humidity atmosphere, the brightness further decreases. Further, when the total conductive powder (C) is 45% or less, sufficient conductivity for making the EL emit light cannot be obtained from the initial stage, resulting in large variation in brightness. All conductive powder (C)
Is 95% or more, a uniform coating film cannot be obtained by printing, the light transmittance is lowered, the luminance is lowered, and the luminance variation is increased. Desirably, (A) :( B) = 100: 0-4
0:60, (C) :( D) = 55: 45 to 80:20 are the best in terms of the balance between light transmittance and conductivity, overlay printing, and stability of conductivity due to environmental changes.

Example 2 The curable insulating resin for transparent electrode paste used in the above Example 1 was made to have the same solid content ratio, and (a) a photocurable resin; an acrylate resin (3031 manufactured by ThreeBond Co.). (B) Photocurable resin; acrylate resin (UR3000 manufactured by Mitsubishi Rayon Co., Ltd.) (c) Thermosetting resin: Urethane-modified epoxy resin (EPU-6A manufactured by Asahi Denka Co., Ltd.) 70% by weight and polyester resin (manufactured by Toyobo # 300) 30% by weight, and 20 parts by weight of imidazole blocked isocyanate (G8009B manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a curing agent was added to 100 parts by weight of the resin.

(D) Thermosetting resin: 60% by weight of an epoxy resin (# 828 manufactured by Yuka Shell Co., Ltd.) and 40% by weight of an epoxy-modified polyester resin (EP2940 manufactured by Toyobo Co., Ltd.) are mixed, and an imidazole blocked isocyanate (No. 1) is used as a curing agent. A product obtained by adding 10 parts by weight of G8009B manufactured by Ichigo Seiyaku Co., Ltd. to 100 parts by weight of the resin.

(E) Comparative Example: 100 parts by weight of cyanoethyl resin (CR-M manufactured by Shin-Etsu Chemical Co., Ltd.) was added to oxime-blocked isocyanate (KE10 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) as a curing agent.
01) 5 parts by weight added.

(F) Comparative Example: 100 parts by weight of polyvinylidene fluoride rubber (Daiel G201 manufactured by Daikin Industries, Ltd.) added with 3 parts by weight of melamine as a curing agent.

(G) Comparative Example: A urethane modified polyester resin (UR8300 manufactured by Toyobo Co., Ltd.) An EL lamp was manufactured in the same manner as in Example 1 using a transparent electrode paste containing the above resins. In addition, about (a), it is 300-400 nm.
The coating film was cured with a UV lamp having an emission wavelength of 1. 1
The initial brightness at 00V 400Hz is (a): 76.
² Cd / m ² (b): 70.3 Cd / m ² (c): 74.
6 Cd / m ² (d): 75.6 Cd / m ² . Further, the level of luminance deterioration of continuous lighting in the atmosphere of 70 ° C. and 60 ° C. 90 to 95% RH was at the same level as in Example 1 above.

Comparative Examples (e) and (g) did not emit light at all. Comparative Example (f) emitted light only in the vicinity of the collector electrode 5a.

(Embodiment 3) The conductive powder of the transparent electrode paste used in the above-mentioned Embodiment 1 was prepared by using acicular indium tin oxide (SCP-SX manufactured by Sumitomo Metal Mining Co., Ltd.) and indium tin oxide fine particle (UFP-X manufactured by Sumitomo Metal Mining Co., Ltd.). Was mixed powder, and the compounding ratio was changed. Moreover, the compounding ratio of all the conductive powders in the insulating resin was changed. Above 2
An EL lamp was manufactured by combining two parameters in a matrix, and the brightness, brightness unevenness, and resistance value of the transparent electrode portion of the finished product were measured, and the results are shown in (Table 1).

[0024]

[Table 1]

The unit of resistance value is kΩ / □, 10 MΩ or more is ∞ (infinity), and the (−) part is not in a paste state, indicating that printing cannot be performed. Luminance is in Cd / m ² . When each of the above samples was left in an atmosphere of 40 ° C. and 90 to 95% RH, the brightness of the needle-like conductive powder was 10% or less, and the brightness was not significantly reduced.

(Embodiment 4) The thermocompression-bonding connection portion 9 at the end of the current collecting electrodes 5a and 5b of the EL lamp of the above-mentioned Embodiment 1 is attached to the printed wiring board 10 by an anisotropic conductive adhesive (CP7131 manufactured by Sony Chemical). Connection was performed under thermocompression bonding conditions of 30 ° C., 35 kg / cm ² , and 30 seconds. FIG. 3 shows a state diagram after thermocompression bonding. A drive inverter circuit was mounted on the printed circuit board side to turn on the light emitting section 7. Even if the wiring portion 8 of the collector electrode was freely bent in the lit state, no abnormality occurred in the lit state.

(Embodiment 5) In the EL lamp of the above Embodiment 1, a 188 μm PET film with an adhesive is attached to the back surface of the terminal ends of the current collecting electrodes 5a and 5b, and FIG. 4 is a partial sectional view of each film. An EL lamp with a connectable connector was produced.

Example 6 In the EL lamp of Example 1 described above, the formation of the back electrode layer 5 and subsequent layers was changed as follows. Current collecting electrodes 5a, 5b; conductive paste (Toyobo DW
-250H), dry film thickness 10 μm. Back electrode layer 5: conductive paste (TOYOBO DY-150H), dry film thickness 8 μ
m. Insulation coat layer 6; insulation paste (TSE3221 made by Toshiba Silicone), dry film thickness 25 μm. The above process was overprinted to manufacture an EL lamp whose cross-sectional view is shown in FIG.
The collector electrodes 5a and 5b are silver resin paste, and the back electrode layer 5 is carbon resin paste.

When 100 V 400 Hz was applied to this sample, the initial luminance was 72.3 Cd / cm ² .

[0030]

As shown in the above examples, in the EL lamp according to the present invention, the conductivity of the transparent electrode layer is lowered even if the light emitting layer and the dielectric layer are overlaid on the transparent electrode layer and the pattern is printed and dried. Since it can be formed by printing, including the transparent electrode layer, it can be manufactured at low cost and the electrical connection of the collector electrode can be facilitated.

Further, there is known a flexible circuit wiring board (FPC) in which a circuit wiring pattern is formed by printing a conductive paste on an insulating transparent film such as PET, but according to the present invention, a pattern is formed in a necessary predetermined portion of the FPC. E by printing
It is easy to form an L lamp and the industrial effect is great.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view taken along a line AB in FIG.

FIG. 3 is a perspective view showing a connection state of an EL lamp to a printed circuit wiring with an anisotropic conductive adhesive according to a fourth embodiment of the present invention.

FIG. 4 is a partial cross-sectional perspective view showing the configuration of each layer of an EL lamp that enables connector connection in Embodiment 5 of the present invention.

FIG. 5 is an AB of an EL lamp according to a sixth embodiment of the present invention.
Sectional view

FIG. 6 is a plan view showing a conventional EL lamp.

7 is a cross-sectional view taken along the line AB of FIG.

FIG. 8 is a cross-sectional view taken along the line AB of the conventional EL lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating transparent film 2 Transparent electrode layer 3 Light emitting layer 4 Dielectric layer 5 Back electrode layer 5a, 5b Current collecting electrode 6 Insulation coating layer 7 Light emitting part 8 Wiring part 9 Thermocompression bonding part 10 Printed circuit wiring board 11 Reinforcing plate

Claims (9)

[Claims] 1. An insulating transparent film as a base material including an external connecting portion, and a transparent electrode layer having a predetermined pattern printed on the upper surface of the insulating transparent film excluding the external connecting portion. A light emitting layer having a predetermined pattern printed on the transparent electrode layer, a dielectric layer having a predetermined pattern printed on the light emitting layer, and a predetermined pattern printed on the dielectric layer. A back electrode layer, and a first current collecting electrode having a predetermined pattern printed and formed so that one end is connected to the back electrode layer and the other end constitutes an external connection portion of the insulating transparent film, A second current collecting electrode having a predetermined pattern formed by printing so that one end is connected to the transparent electrode layer and the other end constitutes an external connection part of the insulating transparent film, and the tip of the external connection part is Except for these on the upper surface EL lamp comprising an insulating coat layer formed by printing so as to cover the. 2. A transparent electrode layer is formed by pattern-printing a paste in which a conductive powder having visible light transparency is dispersed in an insulating resin or a resin solution in which the insulating resin is dissolved. 2. The EL lamp according to claim 1, wherein the conductive powder having a property is indium tin oxide powder, and the insulating resin to be dispersed has a photo-curing property or a heat-curing property. 3. The indium oxide powder as a conductive powder has a shape of acicular powder (A) and fine particle powder (B),
The weight ratio of (A) :( B) is in the range of 100: 0 to 20:80, and the weight ratio of the total conductive powder (C) and the insulating resin (D) dispersed is (C) :( D ) = 45: 55
The EL lamp according to claim 2, wherein the EL lamp has a ratio of about 95: 5. 4. The insulating resin in which the electrically conductive powder having a light-transmitting property is dispersed contains any one or more of an acrylate-based photocurable resin or an epoxy resin, a urethane-modified epoxy resin, and an epoxy-modified polyester resin. The EL lamp according to claim 2, which is a thermosetting resin. 5. The EL lamp according to claim 1, wherein an anisotropic conductive adhesive layer is formed on the first and second current collecting electrodes and the insulating transparent film at the tip of the external connection portion. 6. The reinforcing plate is formed on the back surface of the film at the tip of the external connection portion of the first and second current collecting electrodes.
The EL lamp according to any one of to 4. 7. A transparent electrode layer is formed by screen-printing a paste having visible light transparency on a top surface of an insulating transparent film as a base material in a predetermined pattern and then photo-curing or heat-curing the transparent electrode layer. The phosphor paste is screen-printed on the layer in a predetermined pattern and then dried by heating to form a laminated phosphor layer. Then, the dielectric paste is screen-printed on the phosphor layer in a predetermined pattern and then dried by heating. A dielectric layer is laminated, and then a conductive paste is screen-printed on the dielectric layer in a predetermined pattern and then dried by heating to form a back electrode layer. Then, one end is connected to the transparent electrode layer. A first pattern formed so that the other end forms an external connection electrode part, and one end connects to the back electrode layer and the other end forms an external connection electrode part The second pattern formed as described above is screen-printed with a conductive paste and then dried by heating to form the first and second current collecting electrodes, and then these are covered on the entire surface except the tip of the external connection portion. 5. The method of manufacturing an EL lamp according to claim 1, wherein the insulating paste is screen-printed as described above, and then the insulating coat layer is laminated by photo-curing or heat drying. 8. The method of manufacturing an EL lamp according to claim 7, wherein the back electrode layer and the collector electrode are integrally formed in a predetermined pattern. 9. The method of manufacturing an EL lamp according to claim 7, wherein the collecting electrode is formed before forming the transparent electrode layer.