JP2015144183A - light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a possibility that a light-emitting device may fail when a substrate is held by a base member in a state where a flexure stress is applied to the substrate of the light-emitting device.SOLUTION: A light-emitting element 102 is formed on one surface of a substrate 100. A coating film 190 covers the light-emitting element 102. A base member 200 holds the substrate 100 in a state where a flexure stress is applied to the substrate 100. A base member 200 has a holding part 220. The holding part 220 sandwiches part of the substrate 100 in a thickness direction. A buffer layer 230 is provided at a position overlapping the holding part 220 between the substrate 100 and the base member 200. The buffer layer 230 is positioned between the substrate 100 and the holding part 220, for instance.

Description

  In recent years, development of light-emitting devices using an organic layer as a light-emitting layer has progressed. Such a light-emitting device can be bent when a base material that can be bent is used, as described in Patent Document 1, for example. In Patent Document 1, both ends of the base material of the organic EL panel are fixed to a drive circuit. At this time, the base material is fixed to the drive circuit in a curved state.

  Patent Document 2 describes that a base member of an organic EL element is held by a holding member. The holding member described in Patent Document 2 has a recess. The edge of the organic EL substrate is inserted into the recess.

JP 2002-258774 A JP 2010-49978 A

  One possible method for mounting a light-emitting element having an organic layer is to hold the base material on a base member in a state where bending stress is applied to the base material of the light-emitting element. In this case, the base member needs to be provided with a holding portion that sandwiches the base material in the thickness direction. However, stress concentrates on the portion of the base material that overlaps the holding portion. Depending on the layout of the light emitting element and the wiring, there is a possibility that the light emitting device has a problem due to the stress concentration.

  An example of a problem to be solved by the present invention is to reduce the possibility of failure of the light emitting device when the base member is held in a state where bending stress is applied to the base material of the light emitting element. As mentioned.

The invention according to claim 1 is a substrate;
A light emitting device formed on the substrate and having an organic layer;
A coating film formed on the substrate and covering the light emitting element;
A base member for holding the base material in a state where bending stress is applied to the base material;
With
The base member includes a holding portion that sandwiches a part of the base material in the thickness direction,
Furthermore, it is a light-emitting device provided with the buffer layer located between the said base member and the said base material in the position which overlaps with the said holding | maintenance part.

It is a perspective view which shows the structure of the light-emitting device which concerns on embodiment. It is a side view of a light-emitting device. It is AA sectional drawing of FIG. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is a top view of the base material which a light-emitting device has. FIG. 8 is an enlarged view of a region surrounded by a dotted line α in FIG. 7. It is the figure which removed the insulating layer, the organic layer, the 2nd electrode, the partition, and the coating film from FIG. It is AA sectional drawing of FIG.

  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 perspective view illustrating a configuration of a light emitting device 10 according to the embodiment. FIG. 2 is a side view of the light emitting device 10. 3 is a cross-sectional view taken along the line AA in FIG.

  The light emitting device 10 includes a substrate 100, a light emitting element 102 (described later), a coating film 190 (described later), and a base member 200. The light emitting element 102 is formed on one surface of the substrate 100. The coating film 190 covers the light emitting element 102. The base member 200 holds the base material 100 in a state where bending stress is applied to the base material 100. The base member 200 has a holding part 220. The holding unit 220 sandwiches a part of the base material 100 in the thickness direction. A buffer layer 230 is provided between the base member 100 and the base member 200 at a position overlapping the holding unit 220. The buffer layer 230 is located between the base material 100 and the holding part 220, for example. The light emitting device 10 is, for example, a display, but may be a lighting device. Details will be described below.

  First, the configuration of the light emitting device 10 will be described with reference to FIGS. 1 and 2. The base material 100 has an elongated shape (for example, a rectangle), and overlaps the base member 200 except for a part (one end side in the example shown in the figure). A terminal portion 170 is formed in a region of the base material 100 that does not overlap with the base member 200. The terminal portion 170 is connected to the light emitting element 102 via a first lead wire 130 and a second lead wire 160 described later. The first lead wiring 130 and the second lead wiring 160 are formed on the base material 100. The terminal portion 170 is connected to a conductive member 300 such as a flexible printed circuit (FPC) or a lead frame. The conductive member 300 connects the light emitting device 10 to the control circuit.

  The base material 100 is a transparent substrate such as a glass substrate or a resin substrate. The base material 100 has flexibility, and the thickness thereof is, for example, 10 μm or more and 1000 μm or less.

  The base member 200 includes a bending member 210 and a holding part 220. The bending member 210 is a plate-like member and has an elongated shape. The bending member 210 is curved along the longitudinal direction. And the surface which faces the base material 100 among the curved members 210 is a curved surface. Further, the width of the bending member 210 is slightly wider than the width of the substrate 100. The bending member 210 is provided with a plurality of holding portions 220. The holding part 220 has a shape in which the cross-section L is turned upside down, and a plurality of holding parts 220 are provided on each of the two long sides of the bending member 210. The bending member 210 is made of, for example, a metal such as stainless steel (SUS) or aluminum, or a resin, and the holding portion 220 is made of, for example, a metal such as SUS or aluminum, or a resin. The holding unit 220 is formed by pressing or wire-working plate-shaped SUS or the like and bending it, and then attached to the bending member 210.

  Then, by moving the base material 100 along the curved surface of the bending member 210 while sandwiching the edge of the base material 100 between the holding unit 220 and the bending member 210, the base member 200 is kept in a curved state. Retained. Here, since the base material 100 has elasticity, the base material 100 tries to return to a linear shape. For this reason, pressure is applied to the portion of the substrate 100 that is in contact with the holding portion 220. The holding unit 220 does not overlap with the light emitting element 102.

  The holding unit 220 may be provided integrally with the bending member 210 or may be provided as a member different from the bending member 210.

  A buffer layer 230 is provided between the base material 100 and the base member 200. The buffer layer 230 is made of, for example, a material having a Young's modulus of 5 GPa or less, such as an epoxy resin, an acrylic resin, or a urethane resin. The thickness of the buffer layer 230 is preferably 50 μm or more. However, if the buffer layer 230 is too thick, it is necessary to make the light emitting device 10 thick. Therefore, for example, the thickness is preferably 1 mm or less.

  In the example illustrated in FIG. 3, the buffer layer 230 is located between the holding unit 220 and the base material 100. In the minor axis direction (Y direction in FIG. 3) of the base material 100, the buffer layer 230 is disposed so as to straddle the end portion 222 of the holding unit 220.

  The buffer layer 230 may be positioned between the bending member 210 and the base material 100 as shown in FIG. 4, or at the end of the base material 100 in the minor axis direction as shown in FIG. The substrate 100 may be thicker than the substrate 100. Further, as shown in FIG. 6, the buffer layer 230 may be provided between the holding unit 220 and the base material 100 and between the bending member 210 and the base material 100.

  FIG. 7 is a plan view of the base material 100 included in the light emitting device 10. For the sake of explanation, the second electrode 150, the partition wall 180, and the covering film 190 are omitted in FIG. FIG. 8 is an enlarged view of a region surrounded by a dotted line α in FIG. FIG. 9 is a view in which the insulating layer 120, the organic layer 140, the second electrode 150, the partition wall 180, and the coating film 190 are removed from FIG. 10 is a cross-sectional view taken along the line AA in FIG.

  The light emitting element 102 has a configuration in which the organic layer 140 is sandwiched between the first electrode 110 and the second electrode 150. At least one of the first electrode 110 and the second electrode 150 is a translucent electrode. The remaining electrodes are made of, for example, a metal selected from the first group consisting of Al, Mg, Au, Ag, Pt, Sn, Zn, and In, or an alloy of a metal selected from the first group. Formed by a metal layer. The material of the translucent electrode is, for example, an inorganic material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), a conductive polymer such as a polythiophene derivative, or a network using nanowires made of silver or carbon. Electrode. For example, when the bottom emission type light emitting element 102 has a configuration in which the first electrode 110, the organic layer 140, and the second electrode 150 are stacked on the base material 100 in this order, the first electrode 110. Is a translucent electrode, and the second electrode 150 is an electrode that reflects light such as Al. Further, when the top emission type light emitting element 102 has a configuration in which the first electrode 110, the organic layer 140, and the second electrode 150 are stacked in this order on the base material 100, the first electrode 110. Is an electrode that reflects light, such as Al, and the second electrode 150 is a translucent electrode. Alternatively, both electrodes (the first electrode 110 and the second electrode 150) may be translucent electrodes to form a translucent light emitting device (dual emission type).

  The organic layer 140 has a configuration in which, for example, a hole transport layer, a light emitting layer, and an electron transport layer are stacked in this order. A hole injection layer may be formed between the hole transport layer and the first electrode 110. In addition, an electron injection layer may be formed between the electron transport layer and the second electrode 150. The layer of the organic layer 140 may be formed by a coating method or a vapor deposition method, and a part thereof may be formed by a coating method and the rest may be formed by a vapor deposition method. The organic layer 140 may be formed by vapor deposition using vapor deposition materials for all materials, and the organic layer 140 is formed by ink jet method, printing method, spray method using coating materials for all materials. May be.

  In detail, the 1st electrode 110 is formed in the 1st surface side of the base material 100, and is extended in the shape of a line in the 1st direction (X direction in FIG. 8, 9). The first electrode 110 is made of a light transmissive material. The end portion of the first electrode 110 is connected to the first lead wiring 130.

  In the example shown in the drawing, one end side of the first lead wiring 130 is connected to the first electrode 110, and the other end side of the first lead wiring 130 is one of terminals constituting the terminal portion 170. . The first lead wiring 130 has a configuration in which a first layer 132 and a second layer 134 are stacked. The first layer 132 is formed of the same material as the first electrode 110 and is integrated with the first electrode 110. The second layer 134 has a configuration in which a plurality of metal layers are stacked. Here, the metal layer may be an alloy layer. For example, the metal layer used here is an Mo layer, an Al layer, an alloy layer of Ni and Mo, or an alloy layer of Mo and Nb. The second layer 134 is formed by laminating a plurality of these metal layers. Note that the same metal layer may be laminated a plurality of times.

  8 and 10, an insulating layer 120 is formed on the plurality of first electrodes 110 and in a region therebetween. The insulating layer 120 is formed of a photosensitive material such as polyimide resin. A plurality of openings 122 and a plurality of openings 124 are formed in the insulating layer 120. As will be described in detail later, the plurality of second electrodes 150 extend parallel to each other in a direction intersecting with the first electrode 110 (for example, a direction orthogonal to the Y direction in FIGS. 8 and 9). A partition wall 180 extends between the plurality of second electrodes 150. The opening 122 is located at the intersection of the first electrode 110 and the second electrode 150 in plan view. The plurality of openings 122 are provided at predetermined intervals. The plurality of openings 122 are arranged in the direction in which the first electrode 110 extends (X direction in FIGS. 8 and 9). The plurality of openings 122 are also arranged in the extending direction of the second electrode 150 (the Y direction in FIGS. 8 and 9). For this reason, the plurality of openings 122 are arranged to form a matrix.

  The opening 124 is located at one end of each of the plurality of second electrodes 150 in plan view. The openings 124 are arranged along one side of the matrix formed by the openings 122. When viewed in a direction along one side (for example, the X direction in FIGS. 8 and 9), the openings 124 are arranged at a predetermined interval in the direction along the first electrode 110. A part of the second lead wiring 160 is exposed from the opening 124.

  An organic layer 140 is formed in a region overlapping with the opening 122. The hole transport layer of the organic layer 140 is in contact with the first electrode 110, and the electron transport layer of the organic layer 140 is in contact with the second electrode 150. In this way, the organic layer 140 is sandwiched between the first electrode 110 and the second electrode 150.

  In the example shown in FIG. 10, each layer constituting the organic layer 140 is shown to protrude to the outside of the opening 122. Each layer constituting the organic layer 140 may be formed continuously between the adjacent openings 122 in the direction in which the partition wall 180 extends, or may not be formed continuously. However, the organic layer 140 is not formed in the opening 124.

  As described above, the organic layer 140 is sandwiched between the first electrode 110 and the second electrode 150. As shown in FIGS. 8 and 10, the second electrode 150 is formed above the organic layer 140 and extends in a second direction (Y direction in FIG. 8) that intersects the first direction. The second electrode 150 is electrically connected to the organic layer 140. For example, the second electrode 150 may be formed on the organic layer 140 or may be formed on a conductive layer formed on the organic layer 140. The light emitting device 10 includes a plurality of second electrodes 150 that are parallel to each other. One second electrode 150 is formed in a direction passing over the plurality of openings 122.

  The second electrode 150 is connected to the second lead wiring 160. In the illustrated example, the end of the second electrode 150 is positioned on the opening 124, whereby the second electrode 150 and the second lead wiring 160 are connected in the opening 124.

  The second lead wiring 160 is a wiring connected to the second electrode 150. One end side of the second lead wiring 160 is located below the opening 124, and the other end side of the second lead wiring 160 is drawn to the outside of the insulating layer 120. In the example shown in the drawing, the other end side of the second lead-out wiring 160 is one of the terminals constituting the terminal portion 170. The second lead wiring 160 has a configuration in which a first layer 162 and a second layer 164 are stacked. The first layer 162 is formed of the same material as that of the first layer 132, and the second layer 164 is formed of the same material as that of the second layer 134.

  As described above, the partition wall 180 is formed between the adjacent second electrodes 150. The partition wall 180 is parallel to the second electrode 150, that is, extends in the second direction. The base of the partition wall 180 is, for example, the insulating layer 120. The partition wall 180 is, for example, a photosensitive resin such as a polyimide resin, and is formed in a desired pattern by being exposed and developed. The partition wall 180 is formed using, for example, a negative photosensitive resin. The partition wall 180 may be made of a resin other than a polyimide resin, for example, an inorganic material such as an epoxy resin, an acrylic resin, or silicon dioxide.

  The partition wall 180 has a cross-sectional shape (reverse trapezoidal shape) that is upside down. That is, the width of the upper surface of the partition wall 180 is larger than the width of the lower surface of the partition wall 180. For this reason, when the partition wall 180 is formed before the second electrode 150, the second electrode 150 is formed on one surface side of the substrate 100 by using a vapor deposition method or a sputtering method, whereby a plurality of second electrodes are formed. 150 can be formed at a time. The partition 180 also has a function of dividing the organic layer 140.

Further, as shown in FIGS. 8 and 10, a coating film 190 is formed on the base material 100. The covering film 190 is located above the second electrode 150 and has a function of sealing the light emitting element 102. The covering film 190 is formed using a film forming method such as an ALD (Atomic Layer Deposition) method or a CVD method. In the case of being formed by the ALD method, the coating film 190 is formed of a metal oxide film such as aluminum oxide, and the film thickness thereof is, for example, not less than 10 nm and not more than 200 nm, preferably not less than 50 nm and not more than 100 nm. When formed by the CVD method, the coating film 190 is formed of an inorganic insulating film such as a silicon oxide film, and the film thickness thereof is, for example, not less than 0.1 μm and not more than 10 μm. By providing the coating film 190, the light emitting element 102 is protected from moisture and the like. The coating film 190 may be formed by a sputtering method. In this case, the coating film 190 is formed of an insulating film such as SiO ₂ or SiN. In that case, the film thickness is 10 nm or more and 1000 nm or less. And the surface in which the coating film 190 is formed among the base materials 100 has faced the opposite side to the curved surface of the bending member 210.

  Note that the sealing structure of the light emitting element 102 is a structure in which a resin mold such as an epoxy resin or an acrylic resin is formed on the coating film 190 in addition to the sealing structure (film sealing) illustrated in FIG. There may be. The thickness of the resin mold at this time is preferably 50 μm or more and 200 μm or less, for example. Another example of the sealing structure of the light emitting element 102 may be a hollow sealing structure that seals using a sealing member made of glass or resin. In this case, the distance between the substrate 100 and the sealing member is preferably 10 μm or more and 100 μm or less. Further, as the sealing structure of the light emitting element 102, a filling sealing structure in which an epoxy resin, an acrylic resin, a liquid desiccant, oil, or the like is filled in the gap of the hollow sealing structure described above may be used.

  As described above, the substrate 100 has an elongated shape, for example, a rectangular shape. One of the first electrode 110 and the second electrode 150 (the first electrode 110 in the example shown in this figure) extends in the major axis direction of the base material 100, and the first electrode 110 and the second electrode 150. The other (second electrode 150 in the example shown in this figure) extends to the terminal portion 170 in the minor axis direction of the substrate 100. The first lead wire 130 extends in the same direction as the first electrode 110. On the other hand, the second lead wiring 160 extends to the terminal portion 170 along the edge of the base material 100 in the long axis direction. For this reason, when the 2nd extraction wiring 160 is formed in linear form, a part of 2nd extraction wiring 160 will overlap with the holding | maintenance part 220. FIG.

  As described above, since the restoring force that tries to return to the linear shape works on the base material 100, the force concentrates on the portion of the base material 100 that overlaps the holding portion 220. For this reason, there is a possibility that a malfunction occurs in the light emitting device 10 due to the restoring force of the base material 100. For example, when the holding unit 220 and the second lead wiring 160 overlap, the second lead wiring 160 may be disconnected or may have a high resistance. In addition, the stress applied from the holding unit 220 may cause a crack in a portion of the coating film 190 that overlaps the holding unit 220. If the second lead wiring 160 is located under the cracked portion, the second lead wiring 160 may be deteriorated by moisture or the like.

  On the other hand, in this embodiment, the buffer layer 230 is provided between the base material 100 and the base member 200. For this reason, it can suppress that force concentrates on the specific part among the base materials 100. FIG. As a result, it is possible to suppress the occurrence of the above-described problems. In particular, the force tends to concentrate on the portion of the base material 100 that overlaps the end portion 222 of the holding portion 220, but in this embodiment, the buffer layer 230 is also formed between the base material 100 and the end portion 222. Yes. For this reason, it can further suppress that an above-mentioned malfunction arises.

  In the embodiment described above, the light emitting device 10 is curved in a direction in which the light emitting surface is convex, but may be curved in a direction in which the light emitting surface is concave.

  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.

DESCRIPTION OF SYMBOLS 10 Light-emitting device 100 Base material 102 Light-emitting element 110 1st electrode 140 Organic layer 150 2nd electrode 160 2nd extraction wiring (wiring)
170 Terminal portion 190 Coating film 200 Base member 210 Bending member 220 Holding portion 230 Buffer layer

Claims (5)

A substrate;
A light emitting device formed on the substrate and having an organic layer;
A coating film formed on the substrate and covering the light emitting element;
A base member for holding the base material in a state where bending stress is applied to the base material;
With
The base member includes a holding portion that sandwiches a part of the base material in the thickness direction,
Furthermore, the light-emitting device provided with the buffer layer located between the said base member and the said base material in the position which overlaps with the said holding | maintenance part. The light-emitting device according to claim 1.
A light emitting device comprising a wiring formed on the base material and connected to the light emitting element. The light-emitting device according to claim 2.
A terminal formed on a portion of the base material that does not overlap the holding portion;
The said wiring is the light-emitting device which has connected the said terminal and the said light emitting element. The light emitting device according to claim 3.
The base member has a curved surface facing the substrate;
The light emitting device, wherein the base material is curved along the curved surface. The light-emitting device according to claim 4.
The light-emitting device in which the surface in which the said coating film is formed among the said base materials has faced the opposite side to the said curved surface.

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