JP6496138B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device.

  In recent years, development of light-emitting devices having organic EL (Organic Electroluminescence) elements as light-emitting elements has been progressing. The organic EL element has a configuration in which an organic layer is sandwiched between a first electrode and a second electrode. The first electrode is formed using a transparent conductive material in order to emit light from the organic layer to the outside.

  In Patent Document 1, in the organic EL panel, a sealing member for sealing the light emitting portion is formed of metal, and the distribution of luminance is suppressed by connecting the sealing member and the second electrode. It can be done. In Patent Document 1, the second electrode is also formed on a partition wall that defines a pixel. And the 2nd electrode is connected to the sealing member in the part located on this partition.

JP 2012-79419 A

  Due to the resistance of the first electrode, the luminance of the light emitting element may be distributed. However, the structure described in Patent Document 1 cannot solve such a problem.

  An example of a problem to be solved by the present invention is to prevent the luminance of the light emitting element from being distributed due to the resistance of the first electrode.

The invention according to claim 1 is a polygonal substrate;
A light emitting unit including a first electrode formed on the substrate, a second electrode positioned above the first electrode, and an organic layer positioned between the first electrode and the second electrode;
A first terminal provided on each side of the substrate and connected to the first electrode;
A second terminal connected to the second electrode, which is located on the opposite side of the substrate across the light emitting unit;
It is a light-emitting device provided with.

The invention according to claim 2 is a substrate;
A light emitting unit including a first electrode formed on the substrate, a second electrode positioned above the first electrode, and an organic layer positioned between the first electrode and the second electrode;
A first terminal provided on each side of a region of the substrate located around the first electrode and connected to the first electrode;
A second terminal connected to the second electrode, which is located on the opposite side of the substrate across the light emitting unit;
With
The first terminal is a light emitting device provided at least in each of the regions that are n-fold symmetric (where n ≧ 2) with respect to the center of the substrate.

It is a top view which shows the structure of the light-emitting device which concerns on embodiment. It is the figure which removed the 2nd terminal and sealing member from FIG. FIG. 3 is a diagram in which a second electrode is removed from FIG. 2. It is the figure which removed the insulating layer and the organic layer from FIG. FIG. 5 is a cross-sectional view taken along the line AA in FIG. It is the figure which expanded the area | region enclosed with the dotted line (alpha) of FIG. It is a figure which shows the modification of FIG. It is sectional drawing which shows an example of the method of mounting a light-emitting device on a circuit board. It is sectional drawing which shows the structure of the light-emitting device which concerns on a modification. (A) And (b) is a figure for demonstrating the position of a 1st terminal.

  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.

  FIG. 1 is a plan view showing a configuration of a light emitting device 10 according to the embodiment. FIG. 2 is a view in which the second terminal 132 and the sealing member 160 are removed from FIG. 3 is a view in which the second electrode 130 is removed from FIG. 2, and FIG. 4 is a view in which the insulating layer 150 and the organic layer 120 are removed from FIG. FIG. 5 is a cross-sectional view taken along the line AA in FIG.

  As illustrated in FIG. 5, the light emitting device 10 according to the embodiment includes a substrate 100, a light emitting unit 140, a first terminal 112, and a second terminal 132. The light emitting unit 140 includes a first electrode 110, a second electrode 130, and an organic layer 120 as shown in FIG. The second electrode 130 is located above the first electrode 110, and the organic layer 120 is located between the first electrode 110 and the second electrode 130. As shown in FIG. 5, the first terminal 112 is provided in a region located around the first electrode 110 and is connected to the first electrode 110. As shown in FIG. 1, the first terminal 112 is provided at least in each of the regions that are n-fold symmetric (where n ≧ 2) with respect to the center of the substrate 100. Here, the center of the substrate 100 is the center of the edge when the substrate 100 is circular, and is the intersection of diagonal lines when the substrate 100 is rectangular or square. The second terminal 132 is connected to the second electrode 130. As shown in FIGS. 1 and 5, the second electrode 130 is located on the opposite side of the substrate 100 with the light emitting unit 140 interposed therebetween. In addition, at least a part of the second electrode 130 overlaps the light emitting unit 140. Hereinafter, the light emitting device 10 will be described in detail.

  First, the light emitting device 10 will be described with reference to FIGS.

The substrate 100 is a light-transmitting substrate such as a glass substrate or a resin substrate. The substrate 100 may have flexibility. In the case of flexibility, the thickness of the substrate 100 is, for example, not less than 10 μm and not more than 1000 μm. The substrate 100 is, for example, a rectangle or a square, but may be another polygon or a circle. When the substrate 100 is a resin substrate, the substrate 100 is formed using, for example, PEN (polyethylene naphthalate), PES (polyethersulfone), PET (polyethylene terephthalate), or polyimide. In the case where the substrate 100 is a resin substrate, an inorganic barrier film such as SiN _x or SiON is formed on at least one surface (preferably both surfaces) of the substrate 100 in order to prevent moisture from passing through the substrate 100. Yes.

  A light emitting unit 140 is formed on the first surface 102 of the substrate 100. The light emitting unit 140 has a configuration in which the first electrode 110, the organic layer 120, and the second electrode 130 are stacked in this order.

  The first electrode 110 is a transparent electrode having optical transparency. The material of the transparent electrode is a metal-containing material, for example, a metal oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IWZO (Indium Tungsten Zinc Oxide), or ZnO (Zinc Oxide). The thickness of the first electrode 110 is, for example, not less than 10 nm and not more than 500 nm. The first electrode 110 is formed using, for example, a sputtering method or a vapor deposition method. The first electrode 110 may be a carbon nanotube or a conductive organic material such as PEDOT / PSS.

  The organic layer 120 has a light emitting layer. The organic layer 120 has a configuration in which, for example, a hole injection layer, a light emitting layer, and an electron injection layer are stacked in this order. A hole transport layer may be formed between the hole injection layer and the light emitting layer. In addition, an electron transport layer may be formed between the light emitting layer and the electron injection layer. The organic layer 120 may be formed by a vapor deposition method. In addition, at least one layer of the organic layer 120, for example, a layer in contact with the first electrode 110, may be formed by a coating method such as an inkjet method, a printing method, or a spray method. In this case, the remaining layers of the organic layer 120 are formed by vapor deposition. Moreover, all the layers of the organic layer 120 may be formed using the apply | coating method.

  The second electrode 130 is made of, for example, a metal selected from the first group consisting of Al, Au, Ag, Pt, Mg, Sn, Zn, and In, or an alloy of a metal selected from the first group. Contains a metal layer. In this case, the second electrode 130 has a light shielding property. The thickness of the second electrode 130 is, for example, not less than 10 nm and not more than 500 nm. However, the second electrode 130 may be formed using the material exemplified as the material of the first electrode 110. The second electrode 130 is formed using, for example, a sputtering method or a vapor deposition method.

  The edge of the first electrode 110 is covered with an insulating layer 150. The insulating layer 150 is made of, for example, a photosensitive resin material such as polyimide, and surrounds a portion of the first electrode 110 that becomes a light emitting region of the light emitting unit 140. By providing the insulating layer 150, it is possible to suppress the first electrode 110 and the second electrode 130 from being short-circuited at the edge of the light emitting unit 140. In the example shown in this drawing, the edge of the second electrode 130 overlaps the upper surface of the insulating layer 150.

  In addition, the light emitting device 10 has a first terminal 112. The first terminal 112 is connected to the first electrode 110. Specifically, the first terminal 112 has a layer formed of the same material as the first electrode 110. This layer is integrated with the first electrode 110. As described above, the first terminal 112 is provided at least in each of the regions that are n-fold symmetric (where n ≧ 2) with respect to the center of the substrate 100. Note that n ≧ 3 or n ≧ 4 may be satisfied. Here, as shown in FIG. 10A, the position of the first terminal 112 can be defined as follows, for example. First, a certain reference point is determined. Then, using this reference point as a reference, each point that is n-fold symmetric with respect to a certain point as a rotation center (hereinafter referred to as n-fold symmetric point) is defined. Then, as shown in FIG. 10B, when the reference point is positioned so as to overlap any one of the first terminals 112, each of the n-th symmetry points overlaps any one of the first terminals 112. In the example shown in FIG. 4, the layer that becomes the first electrode 110 and the first terminal 112 is formed on substantially the entire first surface 102 of the substrate 100 (for example, the light emitting portion 140 and its surrounding region). For this reason, the first terminal 112 is provided on each side of the substrate 100. Further, the first terminal 112 is also provided on the entire circumference of the first electrode 110. For ease of manufacturing, only the first terminal 112 may be formed on the substrate 100. In FIG. 4, the first terminal 112 may not be formed in a region facing the corner portion of the substrate 100. A portion of this layer located outside the insulating layer 150 is the first terminal 112. In the case where the substrate 100 is a resin substrate, the barrier function of the substrate 100 can be improved by forming the first electrode 110 on substantially the entire first surface 102. Note that, as shown in FIG. 10B, even when the layers serving as the first electrode 110 and the first terminal 112 are circular, the first terminal 112 is an n-fold symmetric region (where n ≧ 3). It will be provided in each. In the example of FIG. 10B, the three first terminals 112 are divided from each other. At this time, if the area of each region is equal, luminance unevenness in the light emitting unit 140 can be reduced. A shape in which all the first terminals 112 are connected may be used.

  Note that a conductive layer made of a material having lower resistance than the first electrode 110 may be formed on the first electrode 110 and the first terminal 112. This conductive layer is formed of, for example, a metal or an alloy. This conductive layer may have a single layer structure or a multilayer structure. The conductive layer has a configuration in which, for example, a Mo alloy layer (for example, a MoNb layer), an Al alloy layer (for example, an AlNd layer), and a Mo alloy layer (for example, a MoNb layer) are formed in this order. And the part located in the 1st electrode 110 among this electrically conductive layer is formed as a some linear electrode, for example. Further, a portion of the conductive layer located on the first terminal 112 may be formed on the entire surface of the first terminal 112. By forming this conductive layer, the apparent resistance of the first electrode 110 and the first terminal 112 is lowered.

  In addition, the light emitting device 10 has a second terminal 132. In the example shown in FIGS. 1 and 5, the second terminal 132 is provided on the sealing member 160. The sealing member 160 seals the light emitting unit 140. The sealing member 160 has conductivity, and has, for example, a shape in which a central portion of a metal foil or a metal plate is recessed. The sealing member 160 is formed using, for example, aluminum. The sealing member 160 is fixed on the substrate 100 so that the light emitting unit 140 is accommodated in the recess. The second terminal 132 is formed on the outer surface of the sealing member 160, that is, the surface opposite to the light emitting unit 140. In the example shown in this drawing, the entire circumference of the end portion of the sealing member 160 overlaps the insulating layer 150.

  6 is an enlarged view of a region surrounded by a dotted line α in FIG. An end portion of the sealing member 160 is fixed to the second electrode 130 via the conductive adhesive layer 170. 5 is formed on the sealing member 160. The second terminal 132 shown in FIG. The sealing member 160 is formed using a conductive material such as metal. For this reason, the second terminal 132 is electrically connected to the second electrode 130 via the sealing member 160 and the conductive adhesive layer 170. The conductive adhesive layer 170 is, for example, an insulating resin material mixed with conductive particles. In the case where the adhesion between the second electrode 130 and the insulating layer 150 is not good, a metal film (for example, ITO) having a good compatibility with the adhesion may be formed on the insulating layer 150. In this case, the second electrode 130 is connected to a metal film having good compatibility with the insulating layer 150.

  FIG. 7 is a diagram showing a modification of FIG. In the example shown in this drawing, the main body of the sealing member 160 is formed of an insulating material such as glass. A conductive layer 162 (for example, a metal layer such as an aluminum layer) is formed on the end face and the outer surface of the sealing member 160 using a vapor deposition method (for example, a vapor deposition method or a sputtering method). In this modification, the second terminal 132 is electrically connected to the second electrode 130 via the conductive layer 162 and the conductive adhesive layer 170.

  FIG. 8 is a cross-sectional view illustrating an example of a method for mounting the light emitting device 10 on the circuit board 20. In the light emitting device 10, the surface on which the sealing member 160 is provided is opposed to the circuit board 20 (for example, a printed wiring board: PCB). The circuit board 20 has a terminal connected to the second terminal 132 in a region overlapping with the second terminal 132, and a terminal connected to the first terminal 112 in a region overlapping with the first terminal 112. Yes. These terminals are connected to the second terminal 132 and the first terminal 112 through the conductive adhesive layer 202. The conductive adhesive layer 202 is, for example, an insulating resin material mixed with conductive particles.

  In the example shown in FIGS. 1 to 4, the first terminal 112 is formed on the entire circumference of the first electrode 110. In this case, the conductive adhesive layer 202 shown in FIG. 8 is provided so as to surround the first electrode 110.

  As described above, according to the present embodiment, the second terminal 132 is located on the opposite side of the substrate 100 with the light emitting unit 140 interposed therebetween. Therefore, the first terminal 112 can be provided at least in each of the regions that are n times symmetrical (where n ≧ 3) with respect to the center of the substrate 100. In the example illustrated in FIG. 4, the first terminal 112 is provided on each side of the substrate 100, for example. For this reason, current can be supplied to the first electrode 110 from a plurality of regions (all circumferences in the examples shown in FIGS. 1 to 4) in the edge of the first electrode 110. Therefore, even if the resistance of the first electrode 110 is high, it is possible to suppress the distribution of the luminance of the light emitting unit 140 due to this resistance.

(Modification)
FIG. 9 is a cross-sectional view illustrating a configuration of a light emitting device 10 according to a modification, and corresponds to FIG. 5 of the embodiment. The light emitting device 10 according to this modification has the same configuration as that of the light emitting device 10 according to the embodiment except for the electrical connection structure of the sealing member 160 and the second electrode 130.

  In this modification, the end surface of the sealing member 160 is fixed to the substrate 100 side using a general adhesive. Here, the end surface of the sealing member 160 may be fixed to the second electrode 130, may be fixed to a region of the first terminal 112 on the first electrode 110 side, or fixed to the insulating layer 150. May be.

  A part of the inner surface of the sealing member 160 facing the second electrode 130 is electrically connected to the second electrode 130 through the conductive adhesive layer 170. Therefore, the second terminal 132 is electrically connected to the second electrode 130 through the sealing member 160 and the conductive adhesive layer 170. Here, the conductive adhesive layer 170 may overlap the second terminal 132.

  Also according to this modification, the first terminal 112 can be provided on each side of the substrate 100 as in the embodiment. For this reason, current can be supplied to the first electrode 110 from many regions of the edge of the first electrode 110. Therefore, even if the resistance of the first electrode 110 is high, it is possible to suppress the distribution of the luminance of the light emitting unit 140 due to this resistance.

  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.

10 light emitting device 100 substrate 110 first electrode 112 first terminal 120 organic layer 130 second electrode 132 second terminal 140 light emitting part 160 sealing member 162 conductive layer 170 conductive adhesive layer

Claims (8)

And the base plate,
A light emitting unit including a first electrode formed on the substrate, a second electrode positioned above the first electrode, and an organic layer positioned between the first electrode and the second electrode;
A first terminal provided on each side of the substrate and connected to the first electrode;
A second terminal that is located on the opposite side of the substrate across the light emitting portion and is electrically connected to the second electrode;
A conductive layer located at least around the entire circumference of the second electrode, and electrically connecting the second electrode and the second terminal;
A light emitting device comprising: A substrate,
A light emitting unit including a first electrode formed on the substrate, a second electrode positioned above the first electrode, and an organic layer positioned between the first electrode and the second electrode;
A first terminal provided on each side of a region of the substrate located around the first electrode and connected to the first electrode;
A second terminal connected to the second electrode, which is located on the opposite side of the substrate across the light emitting unit;
A conductive layer located at least around the entire circumference of the second electrode, and electrically connecting the second electrode and the second terminal;
With
The light emitting device is provided in each of the regions where the first terminal is at least n-fold symmetric (where n ≧ 2) with respect to the center of the substrate. The light-emitting device according to claim 1 or 2,
It said first terminal, you position continuously in the entire periphery of the first electrode emission device. In the light-emitting device as described in any one of Claims 1-3,
A sealing member for sealing the light emitting part;
The second terminal is a light emitting device provided on the sealing member. The light-emitting device according to claim 4.
The conductive layer is a conductive adhesive layer;
The sealing member is part via the conductive adhesive layer connected to the second electrode,
A light-emitting device provided with the conductor which electrically connects the area | region connected to the said 2nd electrode among the said sealing members, and the said 2nd terminal. The light emitting device according to claim 5.
The sealing member is formed using a conductive material,
The light emitting device, wherein the conductor is the sealing member. In the light-emitting device as described in any one of Claims 1-6,
The first electrode is formed on the substrate;
The first terminal has the same layer as the first electrode, and the layer is integrated with the first electrode.   In the light-emitting device as described in any one of Claims 1-7,
  The entire circumference of the second electrode is a light emitting device connected to the conductive layer.

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