JP5082628B2 - Organic EL panel - Google Patents

Description

  The present invention relates to an organic EL panel that performs surface-emitting illumination using an EL (electroluminescence) phenomenon.

  In recent years, organic EL panels have been demanded as surface-emitting light sources that illuminate a large area such as various lighting fixtures and light posters. This organic EL panel generates little heat, and is lightweight and thin. In particular, the organic EL element is easier to select colors than the inorganic EL element, has a low driving voltage, and saves power. Have various advantages.

  By the way, as this kind of organic EL panel, there has been conventionally provided a structure as shown in FIGS. 6 to 8 (see, for example, Patent Document 1). 6 is a plan view of a conventional organic EL panel, FIG. 7 is a cross-sectional view taken along line CC in FIG. 6, and FIG. 8 is a cross-sectional view taken along line DD in FIG.

  This organic EL panel has an anode layer 2 made of a transparent electrode such as ITO, an organic EL layer 3 having a fluorescent material using an organic compound, and a cathode layer made of a back electrode such as aluminum on a transparent substrate 1 such as glass. 4 is provided, and a cap-shaped sealing plate 6 made of a glass plate or the like is provided so as to cover the light-emitting portion 5. The bottom is fixed to the substrate 1 with an adhesive 7 such as an epoxy resin.

Here, the reason why the sealing plate 6 is provided and the inside thereof is sealed is to prevent the organic compound constituting the organic EL layer 3 from deteriorating when exposed to moisture or oxygen. Because. In order to cause the organic EL layer 3 to emit light, a predetermined voltage needs to be applied between the upper and lower anode layers 2 and the cathode layer 4. Therefore, a part of the anode layer 2 and the cathode layer 4 is drawn out from the sealing plate 6 so as to be exposed to the outside, and the lead-out portions are secured as the power supply terminal portions 2a and 4a, and power supply wiring is connected thereto. I have to.
JP 2004-71246 A

  By the way, in the organic EL panel having the conventional configuration shown in FIGS. 6 to 8, the light emitting part 5 is provided at the peripheral part of the substrate 1 because the peripheral part of the sealing plate 6 needs to be fixed to the substrate 1 with an adhesive 7 or the like. To the portion where the sealing plate 6 is fixed inwardly by the width w. Therefore, there is a non-light-emitting portion of a certain width w over the entire circumference of the substrate 1, and as a result, the area ratio occupied by the non-light-emitting portion with respect to the light-emitting portion 5 is increased, and the light emission amount per unit area of the organic EL panel It has become an obstacle to increase.

  In addition, when performing larger surface-emitting illumination by joining together a plurality of organic EL panels, a large non-light emitting area exists at the jointed part in the conventional one, and a sufficient amount of light emission cannot be obtained. Not only that, it looks bad.

  The present invention has been made to solve the above-described problems, and can significantly increase the light emission amount per unit area of the organic EL panel as compared with the prior art. An object of the present invention is to provide an organic EL panel capable of obtaining a sufficient amount of light emission with few non-light emitting regions even when used together.

  In order to achieve the above object, the organic EL panel according to the first aspect of the present invention has a light emitting portion in which a transparent anode layer, an organic EL layer, and a cathode layer are sequentially laminated on a transparent substrate. And a sealing plate is provided so as to cover the light emitting part, and the light emitting part and the sealing plate cover substantially the entire surface of the substrate in a state where the entire opposing surfaces overlap each other. It is formed in the same planar shape so as to cover, and the peripheral edge portion excluding the portion where the power supply terminal is formed on the substrate and the light emitting portion corresponding thereto and the peripheral edge portion of the sealing plate are stacked so as not to be displaced from each other. The side edge surfaces of the laminated peripheral edge portions are welded with a sealant.

  The organic EL panel according to claim 2 is characterized in that, in the configuration of the invention according to claim 1, the thermal expansion coefficients of the substrate and the sealing plate are set to substantially coincide with each other.

  The organic EL panel according to claim 3 is characterized in that, in the configuration of the invention according to claim 2, the sealant is made of low-melting glass.

  According to a fourth aspect of the present invention, there is provided the organic EL panel according to the third aspect of the present invention, characterized in that the low-melting glass as the sealing agent is laser-welded.

  According to the first aspect of the present invention, since the inside of the panel is sealed with the sealant, it is possible not only to reliably prevent the deterioration of the characteristics of the light emitting portion, but also to emit light over substantially the entire surface including the peripheral portion of the substrate. Therefore, the amount of light emission per unit area of the organic EL panel can be greatly increased as compared with the conventional case. In addition, when a plurality of organic EL panels are used together, the non-light emitting area is small, so that a sufficient amount of light emission can be obtained and the appearance is good.

  In the invention according to claim 2, since the thermal expansion coefficients of the substrate and the sealing plate are set to substantially coincide with each other, the side end surface of the peripheral portion where the substrate, the light emitting portion, and the sealing plate overlap with each other is sealed. When welding with an agent, there is no fear of excessive thermal distortion with respect to the sealant, and the light emitting part can be reliably sealed over a long period of time.

  In the invention of claim 3, if low melting point glass is used as the sealant, it is easy to weld, and it is easy to make the thermal expansion coefficient substantially coincide with that of the substrate or the seal plate. The risk of excessive thermal distortion is further reduced, and the light emitting part can be reliably sealed.

  In the invention of claim 4, since the low-melting glass as the sealant is laser-welded, the sealant can be welded only locally, and problems such as deterioration of the organic EL layer occur during the sealing process. Can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a plan view showing a configuration of an organic EL panel according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line BB in FIG. The components corresponding to or corresponding to those of the prior art shown in FIGS. 6 to 8 are denoted by the same reference numerals.

  The organic EL panel of this embodiment includes a transparent substrate 1, and a light emitting unit 5 in which an anode layer 2, an organic EL layer 3, and a cathode layer 4 are sequentially stacked is provided on the substrate 1. The sealing plate 6 is integrally bonded via an adhesive 7 such as an ultraviolet curable epoxy resin so as to cover the entire surface of the light emitting portion 5. Here, transparent glass is applied to the substrate 1 in this example, but transparent polyethylene terephthalate (PET) resin or the like can also be applied.

  The anode layer 2 is made of a transparent electrode such as ITO or ZnO. The organic EL layer 3 is obtained by dispersing a high-molecular or low-molecular organic fluorescent substance in a resin binder. The cathode layer 4 is made of a metal electrode such as Al or Au. The portion of the organic EL layer 3 sandwiched between the anode layer 2 and the cathode layer 4 is the light emitting portion 5 described above.

  The sealing plate 6 is made of a material having a thermal expansion coefficient substantially the same as that of the substrate 1, that is, a thin glass plate in this example. However, the sealing plate 6 is not limited to such a glass plate. An alloy plate or the like can also be applied because the thermal expansion coefficient is close to that of the substrate 1.

  The substrate 1, the light emitting unit 5, and the sealing plate 6 are all rectangular, and the light emitting unit 5 and the sealing plate 6 cover substantially the entire surface of the substrate 1 with the opposing surfaces overlapping each other. It is formed in the same planar shape so as to cover. Therefore, the light emitting unit 5 and the sealing plate 6 have the same dimensions on the long side and the short side, but are slightly different from the substrate 1. That is, the dimensions of the short side of the substrate 1, the light emitting unit 5, and the sealing plate 6 are all the same, but the dimension of the long side is slightly smaller for the substrate 1 than for the light emitting unit 5 and the sealing plate 6. It is formed to be long. On one end side (left side in FIG. 1) that is not covered with the light emitting section 5 or the sealing plate 6 on the substrate 1, feed terminals 2a and 4a led out from the anode layer 2 and the cathode layer 4 are provided. ing.

  Furthermore, the peripheral portions of the three sides excluding the positions where the power supply terminals 2a and 4a of the substrate 1 are formed and the peripheral portions of the light emitting portion 5 and the sealing plate 6 corresponding thereto are stacked so as not to be displaced from each other. The side end surfaces of these laminated peripheral edge portions are welded with a sealant 8. Moreover, the sealing agent 8 is welded so that the location located in the remaining 1 side (left side in a figure) may cover the light emitting part 5 and the side end surface of the sealing board 6. FIG. As the sealant 8 in this case, the low melting point glass is preferable in terms of easiness of the welding process and the point that the thermal expansion coefficient is close to that of the substrate 1 and the sealing plate 6, but is not limited to this, and is UV-cured. It is also possible to use a mold or a thermosetting adhesive.

  In the above example, the side end surface of the peripheral portion where the substrate 1, the light emitting portion 5, and the sealing plate 6 are laminated is flush with the sealing agent 8 being welded thereon. For example, the sealing agent 8 is applied in advance, for example, the side end face is processed into a V shape as shown in FIG. 4A, or is processed into a concave shape as shown in FIG. 4B. You may process in the shape which is easy to do.

  The procedure for sealing the light-emitting portion 5 formed on the substrate 1 when manufacturing the organic EL panel having the above-described configuration will be described with reference to the process diagram of FIG.

  When the light emitting part 5 in which the anode layer 2, the organic EL layer 3 and the cathode layer 4 are sequentially deposited on the substrate 1 to form the light emitting part 5 is formed (S1), the N2 atmosphere is not exposed to the atmosphere. First, the adhesive 7 such as an ultraviolet curable epoxy resin is uniformly applied on the cathode layer 4 (S2). Next, the sealing plate 6 is positioned and placed thereon, irradiated with ultraviolet rays, and the adhesive 7 is cured (S3). Thereby, the sealing plate 6 is fixed on the light emitting unit 5.

  Then, the sealing agent 8 is apply | coated so that each side end surface of 3 sides where the board | substrate 1, the light emission part 5, and the sealing board 6 are laminated | stacked may be covered. Further, the sealing agent 8 is similarly applied to the remaining one side (left side in the figure) so as to cover the side end face on which the light emitting portion 5 and the sealing plate 6 are laminated (S4).

  And the laser beam is irradiated to the location which apply | coated the sealing agent 8, and the sealing agent 8 is welded (S5). Thereby, the light emission part 5 is sealed reliably. In addition, if the low melting point glass as the sealing agent 8 is laser welded in this way, the heat applied at that time can be locally limited, and the organic EL layer 3 deteriorates during the sealing process. This is convenient because it can prevent the occurrence of defects.

  As described above, since the inside of the organic EL panel of this embodiment is sealed with the sealant 8, not only can the characteristic deterioration of the light emitting unit 5 be reliably prevented, but also the substrate 1 Since the light emitting portion 5 can be secured over substantially the entire surface including the peripheral portion, the amount of light emission per unit area of the organic EL panel can be significantly increased as compared with the conventional case. In addition, even when a plurality of organic EL panels are used together, a sufficient amount of light emission can be obtained with a small non-light emitting area.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, the organic EL panel of the above-described embodiment has a quadrangular shape in plan view, but the present invention is not limited to this and can be applied to a triangular shape or a polygonal shape.

It is a top view which shows the structure of the organic electroluminescent panel in embodiment of this invention. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which shows the modification in the case of sealing a panel side end surface with a sealing agent in embodiment of this invention. It is process drawing explaining the procedure which seals the light emission part formed on the board | substrate in manufacture of the organic electroluminescent panel of this invention. It is a top view which shows the structure of the conventional organic electroluminescent panel. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode layer 3 Organic EL layer 4 Cathode layer 5 Light emitting part 6 Sealing plate 7 Adhesive 8 Sealant

Claims (4)

In an organic EL panel in which a light-emitting part in which a transparent anode layer, an organic EL layer, and a cathode layer are sequentially laminated is provided on a transparent substrate, and a sealing plate is provided to cover the light-emitting part The light emitting portion and the sealing plate are formed in the same planar shape so as to cover substantially the entire surface of the substrate in a state where the entire surfaces of the light emitting portion and the sealing plate overlap each other, and formation of the power supply terminal of the substrate It is stacked so that the peripheral edge of three sides excluding a portion and each of the peripheral portion of the light emitting portion and the sealing plate corresponding thereto is not positioned displaced from each other, and the side end surface of the peripheral portion of each of said stacked is flush The organic EL panel is characterized in that the side end face is processed into a concave shape and is welded with a sealant at the concave end of the side end face .   2. The organic EL panel according to claim 1, wherein the thermal expansion coefficients of the substrate and the sealing plate are set to substantially coincide with each other.   The organic EL panel according to claim 2, wherein the sealant is made of low-melting glass.   4. The organic EL panel according to claim 3, wherein the low-melting glass as the sealant is laser-welded.

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