JPWO2015097857A1 - Light emitting device - Google Patents

Abstract

The light emitting device (10) includes a substrate (100), a light emitting unit (102), and a covering member (200). The light emitting section (102) is formed on the substrate (100) and has an organic EL element. The covering member (200) covers the light emitting portion (102). And the surface on the opposite side to a board | substrate (100) among coating | coated members (200) has a convex part (202) in an edge. The light emitting device (10) is, for example, a lighting device, but may be a display. The convex portion (202) is provided, for example, on the entire circumference of the covering member (200).

Description

  The present invention relates to a light emitting device.

  In recent years, organic EL elements have been used as light sources for light emitting devices. An organic EL element uses an organic layer as a light emitting layer. As a technique related to such a light emitting device, there are techniques described in Patent Documents 1 and 2, for example.

  Patent Document 1 describes that a diffraction grating film is attached to the upper surface of a protective layer covering an organic EL element. In Patent Document 1, the edge of the diffraction grating film is supported by a sealing member provided on the substrate. The sealing member is provided at the edge of the substrate and has a sealing agent inside. The sealing agent adheres the diffraction grating film to the substrate.

  Patent Document 2 describes that an organic layer is sealed by providing a sealing plate on a substrate provided with an organic layer. The sealing plate is fixed to the substrate by an adhesive provided on the edge of the substrate. And the recessed part dented on the opposite side to the organic layer is provided in the part located on the organic layer among the inner surfaces of the sealing plate. An adsorbent having a hygroscopic action is disposed in the recess.

JP 2007-294336 A JP 2002-231442 A

  One feature of a light-emitting device using an organic EL element as a light-emitting element is that the thickness can be reduced. On the other hand, when fixing a light-emitting device, attachment members, such as an adhesive sheet, may be used for the back surface of a light-emitting device. In this case, even if the light emitting device is thinned, since the mounting member is present, the substantial thickness of the light emitting device is increased.

  An example of a problem to be solved by the present invention is to prevent the substantial thickness of the light emitting device from increasing even if an attachment member is provided on the back surface of the light emitting device.

The invention according to claim 1 is a substrate;
A light emitting part formed on the substrate and having an organic EL element;
A covering member for covering the light emitting part;
With
The surface of the covering member opposite to the substrate is a light emitting device having a convex portion at the edge.

  The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is a top view which shows the structure of the light-emitting device which concerns on embodiment. It is AA sectional drawing of FIG. It is a figure for demonstrating an example of the method of attaching a light-emitting device to an attachment surface. It is sectional drawing which shows the structure of the light-emitting device based on an Example. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the structure of the organic EL element which a light emission part has in an Example. It is sectional drawing which shows the structure of the light-emitting device concerning a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(Embodiment)
FIG. 1 is a plan view showing a configuration of a light emitting device 10 according to the embodiment. FIG. 2 is a cross-sectional view taken along the line AA of FIG. The light emitting device 10 according to the embodiment includes a substrate 100, a light emitting unit 102, and a covering member 200. The light emitting unit 102 is formed on the substrate 100 and has an organic EL element. The covering member 200 covers the light emitting unit 102. And the surface on the opposite side to the board | substrate 100 among the coating | coated members 200 has the convex part 202 in the edge. The light emitting device 10 is a lighting device, for example, but may be a display. Details will be described below.

  The substrate 100 is a transparent substrate such as a glass substrate or a resin substrate. The substrate 100 may have flexibility. In this case, the thickness of the substrate 100 is, for example, not less than 10 μm and not more than 1.1 mm. Also in this case, the substrate 100 may be formed of either an inorganic material or an organic material. The substrate 100 is, for example, a polygon such as a rectangle.

  The light emitting unit 102 includes an organic EL element as described above. The organic EL element has a configuration in which an organic layer is sandwiched between two electrodes. At least one of these two electrodes is a translucent electrode. The remaining electrodes are made of a metal such as Al or Ag. The material of the translucent electrode is, for example, an inorganic material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), or a conductive polymer such as a polythiophene derivative.

  A plurality of organic EL elements may be arranged in the light emitting unit 102 or only one may be arranged. In the latter case, the light emitting device 10 may be either a lighting device or a display. In the case where the light emitting unit 102 includes a plurality of organic EL elements, at least the organic layers among the layers included in the plurality of organic EL elements are separated from each other by an insulating layer (for example, a photosensitive resin layer). In this case, the edge of the light emitting unit 102 is defined by, for example, connecting the edges of the organic layers of the organic EL element. The light emitting device 10 may be a bottom emission type light emitting device that exits from the substrate 100 side or a top emission type light emitting device that exits from the coating member 200 side. FIG. 2 shows an example of the bottom emission type.

  The covering member 200 covers the light emitting unit 102. In the example shown in the figure, the covering member 200 protects the light emitting unit 102 from external force. The covering member 200 also has a function of sealing the organic EL element of the light emitting unit 102. The covering member 200 is made of, for example, an inorganic material such as glass, or a metal material such as stainless steel or Al. However, the covering member 200 may be formed of an organic material such as a resin.

  As described above, the convex portion 202 is provided on the surface of the covering member 200 on the side opposite to the substrate 100. The convex portion 202 is formed by, for example, denting a region of the covering member 200 excluding the edge. In this case, the surface of the covering member 200 opposite to the substrate 100 has a shape in which the convex portion 202 surrounds the periphery of the concave portion 204. And the convex part 202 is provided in the perimeter of the coating | coated member 200. FIG. Further, the convex portion 202 is provided in a portion that does not overlap the light emitting portion 102. When the light emitting device 10 is a square, the convex portion 202 does not need to be provided on the entire circumference of the light emitting device 10. For example, the convex part 202 may be provided on two sides facing each other.

  The covering member 200 is fixed to the substrate 100 via a UV curable adhesive 201 such as an epoxy resin. Thereby, the space between the covering member 200 and the substrate 100 is sealed. This sealed space is filled with an inert gas such as nitrogen. A desiccant 203 such as CaO or SrO is installed in the sealed space.

  The height difference h between the top of the convex portion 202 and the bottom of the concave portion 204 is, for example, 50 μm or more and 150 μm or less. Further, in the example shown in the figure, the side surface of the convex portion 202 is substantially a right angle, but may be a slope. Furthermore, at least a part of the side surface of the convex portion 202 in the cross section may be gently bent. Further, the difference h may be uniform over the entire circumference of the covering member 200 or may have a distribution in one direction (for example, the y direction in FIG. 1).

  In the example shown in the figure, a recess is also formed on the surface of the covering member 200 facing the substrate 100. And the light emission part 102 is located in this recessed part.

  As shown in FIG. 1, the external terminal 104 that connects the two electrodes of the light emitting unit 102 and an external control circuit is provided in a portion of the substrate 100 that is located outside the covering member 200.

  FIG. 3 is a diagram for explaining an example of a method for attaching the light emitting device 10 to the attachment surface 500. In the example shown in this figure, the attachment member 400 is attached to the recess 204 of the covering member 200. The attachment member 400 is, for example, a double-sided tape, an adhesive tape, an adhesive layer, or an adhesive layer. In a state before the light emitting device 10 is attached to the attachment surface 500, the height of the attachment member 400 is higher than the height difference between the convex portion 202 and the concave portion 204. In this state, the attachment member 400 is pressed against the attachment surface 500. As a result, the light emitting device 10 is attached to the attachment surface 500 via the attachment member 400. At this time, since the convex portion 202 abuts on the mounting surface 500, it is possible to suppress an excessive load from being applied to the surface of the covering member 200 on which the mounting member 400 is provided. Accordingly, it is possible to prevent the organic EL element from being damaged due to an excessive load such as a convex portion such as the desiccant 203 coming into contact with the light emitting unit 102.

  As described above, according to the present embodiment, the convex portion 202 is formed on the surface of the covering member 200 on the side opposite to the substrate 100. In other words, a portion of the covering member 200 located inside the convex portion 202 is a concave portion 204. For this reason, it can suppress that the substantial thickness of the light-emitting device 10 becomes thick by arrange | positioning the attachment member 400 in the recessed part 204. FIG.

  The convex portion 202 is formed integrally with a portion of the covering member 200 where the convex portion 202 is not formed (for example, a portion having the concave portion 204). Accordingly, when the substrate 100 is flexible, the light emitting device 10 is applied by applying a force to the convex portion 202 as compared with the case where the convex portion 202 is a member different from the other portions of the covering member 200. It is possible to suppress the occurrence of cracks or the like in the covering member 200 when bent.

  FIG. 4 is a cross-sectional view illustrating a configuration of the light emitting device 10 according to the example. In this embodiment, the light emitting unit 102 is sealed with a sealing member 300. The sealing member 300 is formed using, for example, an ALD (Atomic Layer Deposition) method or a CVD method. When formed by the ALD method, the sealing member 300 is formed of a metal oxide film such as aluminum oxide. When formed by the CVD method, the sealing member 300 is formed of an inorganic insulating film such as a silicon oxide film.

  The covering member 200 is made of a resin, for example, an ultraviolet curable resin. The covering member 200 covers the light emitting unit 102 and the sealing member 300. Specifically, the covering member 200 is in contact with the light emitting unit 102 via the sealing member 300.

  As shown in FIG. 5, a resin layer 302 may be provided between the covering member 200 and the sealing member 300. The resin layer 302 is formed of, for example, an epoxy resin and covers at least a part of the covering member 300 and the substrate 100. In the example shown in this drawing, the covering member 200 is fixed to the substrate substrate 100 using a resin layer 302. By providing the resin layer 302, even if an external pressure is applied to the covering member 200, the sealing member 300 can be prevented from being damaged by the external pressure.

  In addition, about the other structure of the light-emitting device 10, it is as having demonstrated in embodiment.

  FIG. 6 is a cross-sectional view illustrating a configuration of an organic EL element included in the light emitting unit 102 in this embodiment. The organic EL element has a configuration in which a first electrode 110, an organic layer 120, and a second electrode 130 are stacked on a substrate 100. In the example shown in this figure, the light emitted from the light emitting unit 102 is radiated to the outside from the substrate 100 side. For this reason, the first electrode 110 is a translucent electrode.

  The organic layer 120 has a configuration in which a hole transport layer, a light emitting layer, and an electron transport layer are stacked in this order. When the first electrode 110 is an anode, a hole transport layer is formed on the first electrode 110. When the first electrode 110 is a cathode, an electron transport layer is formed on the first electrode 110.

  Here, a method of forming the convex portion 202 on the covering member 200 will be described. The convex portion 202 is formed, for example, by applying a resin material flat by screen printing and then forming the concave portion 204 by etching. As another method, the convex portion 202 and the concave portion 204 may be formed by applying a resin material flat by screen printing and then forming the same material multiple times.

  Further, the convex portion 202 may be formed in this printing step by adjusting the conditions for printing the resin material to be the covering member 200 on the substrate 100. For example, when the convex portion 202 is desired to be raised, the force for pressing the squeegee 620 against the screen 600 is increased. In this case, the convex part 202 and the concave part 204 can be easily formed in the covering member 200.

  Also in this embodiment, a portion of the covering member 200 located inside the convex portion 202 is a concave portion 204. For this reason, it can suppress that the substantial thickness of the light-emitting device 10 becomes thick by arrange | positioning the attachment member 400 in the recessed part 204. FIG.

  The covering member 200 covers the sealing member 300. For this reason, the sealing member 300 is protected by the covering member 200 even when an external force is applied to the surface of the light emitting device 10 opposite to the substrate 100. Therefore, it can suppress that the sealing capability of the sealing member 300 falls.

  The covering member 200 is in contact with the light emitting unit 102 through the sealing member 300. For this reason, depending on the position of the convex part 202, when a force is applied to the convex part 202, this force may be transmitted to the light emitting part 102. On the other hand, the convex part 202 does not overlap the light emitting part 102 in the present embodiment. Therefore, even if force is applied to the convex portion 202, the light emitting portion 102 can be prevented from being deteriorated by this force. Moreover, when the convex part 202 has not overlapped with the sealing member 300, it can suppress that the sealing capability of the sealing member 300 falls by the force added to the convex part 202. FIG.

(Modification)
FIG. 7 is a cross-sectional view illustrating a configuration of a light emitting device 10 according to a modification. The light emitting device 10 according to this modification is a top emission type light emitting device. The light emitting device 10 according to this modification has the same configuration as that of the light emitting device 10 according to any of the embodiment and each example, except for the following points. FIG. 7 shows a case similar to FIG.

  First, the convex part 202 and the concave part 204 are not formed on the surface of the covering member 200 opposite to the light emitting part 102. Instead, a convex portion 106 and a concave portion 105 are formed on the surface of the substrate 100 opposite to the light emitting portion 102.

  Next, a method for manufacturing the light emitting device 10 according to this modification will be described. First, by etching the side of the substrate 100 opposite to the side on which the light emitting portion 102 is formed, the concave portion 105 is formed and at the same time the convex portion 106 is formed. And after forming the convex part 106 in the board | substrate 100, the light emission part 102 is formed and sealing with the sealing member 300 is performed. Thereafter, the covering member 200 is fixed to the substrate 100 using the resin layer 302. When the substrate 100 is formed of thin glass with a thickness of 0.03 mm or more and 0.3 mm or less and the light emitting device 10 is flexible, the convex portion 106 is a fixed portion when the light emitting device 10 is mounted on the housing. Become.

  As mentioned above, although embodiment and the Example were described with reference to drawings, these are illustrations of this invention and can also employ | adopt various structures other than the above.

Claims (6)

A substrate,
A light emitting part formed on the substrate and having an organic EL element;
A covering member for covering the light emitting part;
With
The surface of the said covering member on the opposite side to the said board | substrate is a light-emitting device which has a convex part in the edge. The light-emitting device according to claim 1.
The convex portion is a light emitting device provided on the entire circumference of the covering member. The light-emitting device according to claim 2.
The said convex part is a light-emitting device currently formed integrally with the part in which the said convex part is not formed among the said coating | coated members. The light emitting device according to claim 3.
The light emitting device in which the covering member is made of resin. The light-emitting device according to claim 4.
The light emitting device in which the convex portion does not overlap the light emitting portion. The light emitting device according to claim 5.
A coating film covering the organic EL element;
The light emitting device, wherein the covering member covers the covering film.

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