KR100571092B1 - Flexible inorganic el device - Google Patents

Abstract

A flexible inorganic EL device is disclosed. The present invention is characterized by comprising a substrate made of polymer synthetic rubber, polyurethane or silicone rubber, a busbar, a transparent conductive layer, a fluorescent layer, a dielectric layer, a conductive layer, and a polymer protective film layer. According to the present invention, since the EL device using the PET is more flexible and stretchable than the conventional PET, the durability is improved, and thus the EL device is not damaged even after hundreds of thousands of physical shocks. Since noise can be easily prevented by only changing the structure and adding a material layer, reliability related to electrical and physical properties is improved, and it is particularly useful for EL dome sheets and EL keypads.

Flexible inorganic EL, rubber, polyurethane, silicone, flexibility, busbars, noise, elasticity

Description

Flexible inorganic EL device

1A is a schematic diagram for explaining the flexible EL device according to the first embodiment of the present invention;

1B is a schematic diagram for explaining the flexible EL device according to the second embodiment of the present invention;

Fig. 1C is a schematic diagram showing a flexible EL element of the form in which the first and second embodiments of the present invention are combined;

2A is a schematic diagram for explaining the flexible EL device according to the third embodiment of the present invention;

2B is a schematic diagram for explaining the flexible EL device according to the fourth embodiment of the present invention; And

Fig. 2C is a schematic diagram showing a flexible EL element in which the third and fourth embodiments of the present invention are combined.

<Description of Reference Numbers for Main Parts of Drawings>

110: substrate 120: busbar

130: transparent conductive layer 140: fluorescent layer

150: dielectric layer 160: conductive layer

170: polymer protective film layer 181: polymer layer

182: polymer insulating layer 183: second conductive layer

184: field reinforcement layer

The present invention relates to a flexible inorganic EL (Electro Luminescence) device, and more particularly to a flexible inorganic EL device using a flexible and stretchable substrate.

The conventional EL device uses an ITO film obtained by depositing ITO on a PET film as a substrate. Thus, ITO films are less flexible and have very little stretch. In order to improve this, even if the thickness of the PET film is reduced, it is difficult to realize the thickness of the substrate to 50 μm or less, and even if a thin ITO film is used, the stretchability of the manufactured EL is hardly improved.

The conventional EL keypad forms a boss by molding silicone rubber on an EL manufactured using an ITO film, and a cutting process in the form of an individual key is required to prevent the deterioration of the feeling of click resulting from the lack of elasticity. In addition, the molding process for forming the boss is a molding process at a high temperature and high pressure, which is likely to cause damage to the EL during the process, a lot of defects occur. In addition, an EL keypad using an ITO film has a high possibility of unlitness or deterioration of luminance due to ITO damage caused by repeated key operation.

Accordingly, the technical problem to be achieved by the present invention is to provide a flexible inorganic EL device having improved flexibility and elasticity.

A flexible inorganic EL device according to a first example of the present invention for achieving the above technical problem comprises: a substrate made of a polymer synthetic rubber, polyurethane or silicone rubber; A bus bar formed on the substrate; A transparent conductive layer formed on the bus bar; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the transparent conductive layer; A dielectric layer formed on the fluorescent layer; A conductive layer formed on the dielectric layer; And a polymer protective film layer formed on the conductive layer.

According to a second aspect of the present invention, there is provided a flexible inorganic EL device comprising: a substrate made of a polymer synthetic rubber, polyurethane, or silicone rubber; A transparent conductive layer formed on the substrate; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the transparent conductive layer; A dielectric layer formed on the fluorescent layer; A conductive layer formed on the dielectric layer; A bus bar formed on the conductive layer; It characterized in that it comprises a polymer protective film layer formed on the bus bar.

According to a third aspect of the present invention, there is provided a flexible inorganic EL device comprising: a substrate made of polymer synthetic rubber, polyurethane, or silicone rubber; A bus bar formed on the substrate; A conductive layer formed on the bus bar; A dielectric layer formed on the conductive layer; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the dielectric layer; A transparent conductive layer formed on the fluorescent layer; And a polymer protective film layer formed on the transparent conductive layer.

According to another aspect of the present invention, there is provided a flexible inorganic EL device comprising: a substrate made of polymer synthetic rubber, polyurethane, or silicone rubber; A conductive layer formed on the substrate; A dielectric layer formed on the conductive layer; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the dielectric layer; A transparent conductive layer formed on the fluorescent layer; A bus bar formed on the transparent conductive layer; It characterized in that it comprises a polymer protective film layer formed on the bus bar.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail.

1A is a schematic diagram for explaining the flexible EL device according to the first embodiment of the present invention, and FIG. 1B is a schematic diagram for explaining the flexible EL device according to the second embodiment of the present invention, and FIG. It is a schematic diagram which shows the flexible EL element of the combined form of 1st Example and 2nd Example.

1A to 1C, a flexible inorganic EL device according to example embodiments may include a substrate 110, a bus bar 120, a transparent conductive layer 130, a fluorescent layer 140, and a dielectric layer 150. ), Including the conductive layer 160 and the polymer protective film layer 170 is a common feature of having flexibility and elasticity, but there is only a difference in the structure. Therefore, the characteristics of the material layers, which are overlapping portions in the first and second embodiments, will be described first.

The substrate 110 has a thickness of 1 to 150 µm and is made of flexible and stretchable polymer synthetic rubber, polyurethane, or silicone rubber. The bus bar 120 is formed to have a thickness of 1 to 20 μm by mixing a powder of a highly conductive material such as silver, gold, or copper with a binder. In general, when the transparent conductive layer or the conductive layer is formed by using a conductive paste, the conductivity decreases, and thus, in the present invention, a uniform bus bar is formed by forming a separate bus bar that is highly conductive and has a low conductivity. Complement and remove noise. Therefore, it is preferable that the bus bar is connected to the EL terminal portion. The transparent conductive layer 130 has a thickness of 0.1 to 10 μm, and may be made of an ITO paste made of ITO powder and a binder, an antimony tin oxide (ATO) or a conductive polymer, or a mixed material of the conductive polymer and the ITO powder. As the conductive polymer, for example, a material such as 3,4-ethylenedioxythiophene (PEDOT: PSS) or polyethhylenedioxythiophene (PEDOT: PSS) may be used. The fluorescent layer 140 has a thickness of 1 to 50 µm and is formed of phosphor powder and a binder. The phosphor powder uses a II-VI compound such as ZnS. It is preferable that the binder used for the fluorescent layer has a higher dielectric constant than the phosphor powder. As the binder of the high dielectric constant, cyanoethyl pullulan or fluororesin may be used. The dielectric layer 150 is 1-30 탆 thick and is made of a mixture of dielectric powder and binder. As the dielectric powder, a material having a high dielectric constant such as BaTiO ₃ is used, and its size is about 0.1 to 10 μm. As the binder for the dielectric layer, a polymer having a high dielectric constant such as cyanoethyl pullulan or fluororesin is used. In order to change the emission color of the device, a fluorescent dye such as rhodamine, or a fluorescent pigment may be mixed with the binder of the fluorescent layer or the binder of the dielectric layer. The conductive layer 160 has a thickness of 1 to 30 µm and is made of a mixture of conductive powder and a binder, a conductive organic polymer, or a mixture of conductive powder and a conductive organic polymer. As the conductive powder, for example, carbon powder, silver or copper powder, or copper powder coated with silver is used. As the conductive polymer, for example, materials such as 3,4-ethylenedioxythiophene (PEDOT: PSS) and polyethhylenedioxythiophene (PEDOT: PSS) can be used. The polymer protective layer 170 has a thickness of 1 to 60 μm, and should be excellent in moisture resistance after drying and excellent adhesion to a substrate made of polymer synthetic rubber or the like, or a binder containing a fluorine-based polymer or polyurethane. A polymer that is cured by irradiation with infrared (IR) or ultraviolet (UV) light may be used.

1A and 1B, the structural features of the flexible EL elements according to the first and second embodiments of the present invention will be described.

Example 1

Referring to FIG. 1A, a flexible EL device according to a first exemplary embodiment of the present invention may include a bus bar 120, a transparent conductive layer 130, a fluorescent layer 140, a dielectric layer 150, and a conductive layer on a substrate 110. The layer 160 and the polymer passivation layer 170 are sequentially stacked. In addition, a polymer layer 181 having a thickness of 1 to 60 μm and having the same material as the polymer protective layer 170 is interposed between the substrate 110 and the bus bar 120 to improve their adhesion. In addition, in order to reduce noise, the conductive layer 160 and the polymer passivation layer 170 are 1 to 60 μm thick, and the polymer insulating layer 182 and the thickness of 1 to 30 μm are electrically conductive. The second conductive layer 183 of the same material as the layer 160 is sequentially interposed. The polymer insulating layer 182 and the second conductive layer 183 can cancel the vibration of the EL from each other in front and rear to reduce the generation of audible noise.If one side of the EL terminal is connected to the ground, the EL element and the inside of the mobile phone are connected. Electromagnetic shielding effect between different electrical elements can be obtained. Further, an electric field reinforcing layer 184 having a thickness of 0.1 to 20 mu m is interposed between the fluorescent layer 140 and the dielectric layer 150 to improve the lifetime, brightness and reliability of the EL element. In this case, the polymer layer 181, the polymer insulating layer 182, the second conductive layer 183, and the field reinforcing layer 184 are not necessarily included, and are used as necessary.

On the other hand, since the EL device according to the present embodiment uses a thin substrate, the EL device is manufactured in a state in which a substrate is laminated on a release film or release paper made of a material such as PET or PEN to improve workability during manufacturing. Then, the release film or release paper is produced by a method of separating and removing.

Example 2

Referring to FIG. 1B, a flexible EL device according to a second exemplary embodiment of the present invention may include a transparent conductive layer 130, a fluorescent layer 140, a dielectric layer 150, a conductive layer 160, and a bus on a substrate 110. The bar 120 and the polymer passivation layer 170 are sequentially stacked. In addition, between the substrate 110 and the transparent conductive layer 130, a polymer layer 181 having a thickness of 1 to 60 μm and the same material as that of the polymer protective layer 170 is interposed in order to improve their adhesion. In addition, in order to reduce noise, the bus bar 120 and the polymer passivation layer 170 are 1 to 60 μm thick, and the polymer insulating layer 182 and the thickness of 1 to 30 μm are the same as the polymer passivation layer 170. The second conductive layer 183 of the same material as the layer 160 is sequentially interposed. Further, an electric field reinforcing layer 184 having a thickness of 0.1 to 20 mu m is interposed between the fluorescent layer 140 and the dielectric layer 150 to improve the lifetime, brightness and reliability of the EL element. In this case, the polymer layer 181, the polymer insulating layer 182, the second conductive layer 183, and the field reinforcing layer 184 are not necessarily included, and are used as necessary.

Comparing Embodiment 1 and Embodiment 2 described above, in Embodiment 1, the bus bar 120 is positioned between the substrate 110 and the transparent conductive layer 130 for uniform emission, but in Embodiment 2, the noise is removed. In order to do this, the bus bar 120 is positioned between the conductive layer 160 and the polymer protective layer 170.

Meanwhile, as shown in FIG. 1C, the bus bar 120 may be positioned between the substrate 110 and the transparent conductive layer 130 and between the conductive layer 160 and the polymer protective layer 170.

2A is a schematic diagram for explaining the flexible EL device according to the third embodiment of the present invention, and FIG. 2B is a schematic diagram for explaining the flexible EL device according to the fourth embodiment of the present invention, and FIG. 3 is a schematic view showing a flexible EL element in which a third embodiment and a fourth embodiment are combined.

Embodiments of the present invention according to Figs. 2A to 2C are embodiments according to the inverse phase form of the flexible EL element according to Figs. 1A to 1C, and the same reference numerals are the same elements, and thus repeated description is omitted.

Example 3

Referring to FIG. 2A, the present embodiment is an inverted form of Embodiment 1 according to FIG. 1A, and includes a bus bar 120, a conductive layer 160, a dielectric layer 150, a fluorescent layer 140, and a substrate on a substrate 110. The transparent conductive layer 130 and the polymer protective layer 170 are sequentially stacked. The polymer layer 181 is disposed between the substrate 110 and the bus bar 120, and the polymer insulating layer 182 and the second conductive layer 183 are disposed between the transparent conductive layer 130 and the polymer protective layer 170. The field reinforcement layer 184 may be selectively interposed between the dielectric layer 150 and the fluorescent layer 140.

Example 4

Referring to FIG. 2B, the present embodiment is an inverted form of Embodiment 2 according to FIG. 1B, and includes a conductive layer 160, a dielectric layer 150, a fluorescent layer 140, and a transparent conductive layer 130 on the substrate 110. The bus bar 120 and the polymer passivation layer 170 are sequentially stacked. The polymer layer 181 is disposed between the substrate 110 and the conductive layer 160, and the polymer insulating layer 182 and the second conductive layer 183 are disposed between the busbar 120 and the polymer protective layer 170. The field reinforcing layer 184 may be selectively interposed between the dielectric layer 150 and the fluorescent layer 140.

Meanwhile, as illustrated in FIG. 2C, the bus bars 120 may be positioned between the substrate 110 and the conductive layer 160, and between the transparent conductive layer 130 and the polymer protective layer 170.

The flexible EL device emits light through the substrate 110 according to the embodiments of FIGS. 1A to 1C, but emits light through the polymer protective film layer 170 according to the embodiments of FIGS. 2A to 2C. do.

According to the flexible inorganic EL device according to the present invention as described above, because it uses a substrate made of a polymer synthetic rubber, polyurethane or silicone rubber and the like having excellent flexibility, it is more flexible than the EL device using a conventional PET, so durability This improvement prevents damage to the EL element even after hundreds of thousands of physical shocks, and includes a busbar layer to enable uniform light emission and to remove noise.

In addition, noise can be easily prevented by simple structural changes and addition of a material layer, thereby improving reliability related to electrical and physical properties.

Furthermore, the flexible EL sheet can be usefully applied to EL dome sheets, EL keypads and the like.

The present invention is not limited to the above embodiments, and it is apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

Claims (18)

A substrate made of polymer synthetic rubber, polyurethane or silicone rubber; A bus bar formed on the substrate; A transparent conductive layer formed on the bus bar; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the transparent conductive layer; A dielectric layer formed on the fluorescent layer; A conductive layer formed on the dielectric layer; A flexible inorganic EL device comprising a polymer protective film layer formed over the conductive layer. The flexible inorganic EL device according to claim 1, wherein a polymer layer is interposed between the substrate and the bus bar. The flexible inorganic EL device according to claim 1, wherein a polymer insulating layer and a second conductive layer are sequentially interposed between the conductive layer and the polymer protective film layer. A substrate made of polymer synthetic rubber, polyurethane or silicone rubber; A transparent conductive layer formed on the substrate; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the transparent conductive layer; A dielectric layer formed on the fluorescent layer; A conductive layer formed on the dielectric layer; A bus bar formed on the conductive layer; A flexible inorganic EL device comprising a polymer protective film layer formed on the bus bar. The flexible inorganic EL device according to claim 4, wherein a polymer layer is interposed between the substrate and the transparent conductive layer. The flexible inorganic EL device according to claim 4, wherein a bus bar is interposed between the substrate and the transparent conductive layer. The flexible inorganic EL device according to claim 6, wherein a polymer layer is interposed between the substrate and the bus bar. The flexible inorganic EL device according to claim 4, wherein a polymer insulating layer and a second conductive layer are sequentially interposed between the bus bar and the polymer protective film layer. The flexible inorganic EL device according to claim 1 or 4, wherein an electric field reinforcing layer is interposed between the fluorescent layer and the dielectric layer. A substrate made of polymer synthetic rubber, polyurethane or silicone rubber; A bus bar formed on the substrate; A conductive layer formed on the bus bar; A dielectric layer formed on the conductive layer; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the dielectric layer; A transparent conductive layer formed on the fluorescent layer; A flexible inorganic EL device comprising a polymer protective film layer formed on the transparent conductive layer. The flexible inorganic EL device according to claim 10, wherein a polymer layer is interposed between the substrate and the bus bar. The flexible inorganic EL device according to claim 1, wherein a polymer insulating layer and a second conductive layer are sequentially interposed between the transparent conductive layer and the polymer protective film layer. A substrate made of polymer synthetic rubber, polyurethane or silicone rubber; A conductive layer formed on the substrate; A dielectric layer formed on the conductive layer; A fluorescent layer formed of a mixture of ZnS and a binder having a high dielectric constant and formed on the dielectric layer; A transparent conductive layer formed on the fluorescent layer; A bus bar formed on the transparent conductive layer; A flexible inorganic EL device comprising a polymer protective film layer formed on the bus bar. The flexible inorganic EL device according to claim 13, wherein a polymer layer is interposed between the substrate and the conductive layer. The flexible inorganic EL device according to claim 13, wherein a bus bar is interposed between the substrate and the conductive layer. The flexible inorganic EL device according to claim 15, wherein a polymer layer is interposed between the substrate and the bus bar. The flexible inorganic EL device according to claim 13, wherein a polymer insulating layer and a second conductive layer are sequentially interposed between the busbar and the polymer protective film layer. The flexible inorganic EL device according to claim 10 or 13, wherein an electric field reinforcing layer is interposed between the fluorescent layer and the dielectric layer.

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