JP7353331B2 - light emitting device - Google Patents

Description

The present invention relates to a light emitting device.

An organic EL element is one of the light sources of a light emitting device. An organic EL element has a structure in which a first electrode, an organic layer, and a second electrode are laminated in this order on a substrate. The organic layer has a structure in which a plurality of layers are laminated. Then, by passing a current between the first electrode and the second electrode, the organic layer emits light.

Patent Documents 1 and 2 describe that an organic layer of an organic EL element is patterned into a predetermined shape by using a photolithography method. In particular, Patent Document 2 describes providing an opening in an insulating layer and making the inside of the opening a light emitting part. Patent Document 2 describes that the insulating layer may contain organopolysiloxane.

Japanese Patent Application Publication No. 2002-170673 Japanese Patent Application Publication No. 2010-45050

In recent years, it has been considered to form at least one organic layer of an organic EL element using a coating material. On the other hand, when at least one organic layer is formed using a coating material, the coating material spreads and spreads, making it difficult to control the planar shape of this layer with high precision.

An example of the problem to be solved by the present invention is to control the planar shape of this layer with high precision when at least one organic layer is formed using a coating material.

The first invention includes a substrate;
a structure formed on the substrate and surrounding the coating film;
an organic material having a siloxane bond;
Equipped with
The organic material having the siloxane bond is in contact with an inorganic material forming the substrate or an inorganic material on the substrate,
The inorganic material is a light emitting device in a region surrounding the structure.

A second invention includes a step of forming, on a substrate, a structure surrounding a region where a coating film is to be formed;
a step of attaching an organic material having a siloxane bond to an inorganic material forming the substrate or an inorganic material on the substrate surrounding the formation area of the coating film;
A method of manufacturing a light emitting device comprising:

FIG. 3 is a cross-sectional view showing a method of manufacturing a light emitting device according to an embodiment. FIG. 3 is a cross-sectional view showing a method of manufacturing a light emitting device according to an embodiment. 1 is a cross-sectional view showing a method for manufacturing a light emitting device according to Example 1. FIG. 1 is a cross-sectional view showing a method for manufacturing a light emitting device according to Example 1. FIG. 3 is a plan view of a light emitting device according to Example 2. FIG. 6 is a diagram with the sealing member removed from FIG. 5. FIG. FIG. 7 is a diagram with the second electrode removed from FIG. 6; 8 is a diagram with the organic layer and the insulating layer removed from FIG. 7. FIG. FIG. 6 is a diagram for explaining the relative position between the edge of the sealing member and the region where organic matter is located.

Embodiments of the present invention will be described below with reference to the drawings. Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

1 and 2 are cross-sectional views showing a method of manufacturing a light emitting device 100 according to an embodiment. Light emitting device 100 is formed using substrate 110. The substrate 110 may be, for example, a glass substrate made of an inorganic material such as glass, a substrate made of a member made of glass with a silicon oxide film formed on one side, or a member made of polyimide resin with a silicon oxide film formed on one side. Examples include a substrate on which a film (barrier film) made of an inorganic material such as silicon nitride oxide is formed, a substrate made of a metal material such as aluminum, etc., and has a film or member made of an inorganic material. Note that in the following description, "the surface of the substrate 110" refers to the surface of the substrate 110 itself. Therefore, the "surface of the substrate 110" does not include the surface of the film formed on the substrate 110.

First, as shown in FIG. 1A, a conductive film made of an inorganic material, for example, a transparent conductive film, is formed on a substrate 110. The material of the transparent conductive film is, for example, ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). Next, a resist film made of resist is formed in a predetermined shape on the conductive film, and the conductive film is wet-etched or dry-etched using an organic solvent using the resist film as a mask. As a result, the first electrode 120, the first terminal 150, and the second terminal 160 having a predetermined shape are formed. In the example shown in this figure, the first terminal 150 is formed integrally with the first electrode 120.

Next, an insulating film is formed on the substrate 110 and the first electrode 120, and this insulating film is selectively removed. As a result, an insulating layer 170 (an example of a structure) is formed on the first electrode 120. The insulating layer 170 is formed using a photosensitive resin such as polyimide, and surrounds a region of the first electrode 120 where an organic layer 130 (described later) is formed. Further, a portion of the insulating layer 170 is located between the first electrode 120 and the second terminal 160. In this state, the first electrode 120, the first terminal 150, or the substrate 110 itself is located on the surface of the region of the substrate 110 surrounding the insulating layer 170. All of these are inorganic materials.

Next, as shown in FIG. 1(b), the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. This organic substance is, for example, a silicone-based organic substance, specifically, for example, trimethylsilane. Further, the temperature of the atmosphere is, for example, 100° C. or more and 300° C. or less, and the concentration of organic matter in the atmosphere is, for example, 1 ppm or more and 1000 ppm or less. Further, the time for exposing the substrate 110 to the atmosphere is, for example, 1 minute or more and 60 minutes or less. As a result, the organic substance 190 (organic material) is attached to the substrate 110, the first terminal 150, the insulating layer 170, the first electrode 120, and the second terminal 160 located in the region surrounding the insulating layer 170. In other words, the organic material 190 is located on the surface of an inorganic material (for example, a material different from the first electrode 120, ie, the substrate 110) surrounding the insulating layer 170. The inorganic material is located closer to the substrate 110 than the organic material 190 in the thickness direction, and the organic material having a siloxane bond is in contact with the inorganic material forming the substrate 110 or the inorganic material on the substrate 110. . .

Note that the inorganic material on which the organic substance 190 is located surrounds the entire circumference of the insulating layer 170. In other words, the organic material 190 surrounds the entire circumference of the insulating layer 170. The organic substance 190 may or may not be a layer. However, the inorganic material is not limited to this, and may be formed around the insulating layer 170 or the organic layer 130 and dotted with a plurality of inorganic materials, or may be formed around the entire periphery of the insulating layer 170 or the organic layer 130 to form an annular shape. An inorganic material may be placed.
When the organic substance 190 does not form a layer, the molecules of the organic substance 190 are attached to the above-described inorganic material at a predetermined density. When the organic material 190 is a layer, the thickness of the organic material 190 is thinner than the thickness of any layer constituting the organic layer 130, for example, 1 nm or less. The organic substance 190 adheres to a region of the first electrode 120 located outside the insulating layer 170, in other words, on the edge side of the substrate 110. Note that the presence of the organic substance 190 and the presence or absence of a siloxane bond in the organic substance 190 can be detected using, for example, EDX or ToF-SIMS.

Next, as shown in FIG. 2(a), an organic layer 130 is formed. The organic layer 130 has a structure in which a plurality of layers including a light emitting layer are laminated. The organic layer 130 has at least a hole injection layer, a light emitting layer, and an electron injection layer. At least one layer (for example, a hole injection layer or an electron injection layer) constituting the organic layer 130 is formed using a coating material. As a result, at least one layer constituting the organic layer 130 is formed of a coating film. The organic layer 130 may be a coating film by forming all layers of the organic layer 130 by a coating method. Specific examples of the method for forming a coating film (coating method) using a coating material include, for example, an inkjet method and a dispenser method. The coating material is composed of an organic material forming the organic layer 130 and an organic solvent. Here, an organic substance 190 is attached to the surface of the insulating layer 170 and the inorganic material (for example, the first electrode 120 and the substrate 110) surrounding the insulating layer 170. Since the organic substance 190 has a siloxane bond, it is difficult to wet the coating material for forming the organic layer 130. Therefore, the coating material that becomes the organic layer 130 is difficult to spread from the area surrounded by the insulating layer 170.

Next, as shown in FIG. 2(b), a second electrode 140 is formed on the organic layer 130. A portion of the second electrode 140 is connected to the second terminal 160 beyond the insulating layer 170. The second electrode 140 is made of a metal selected from the first group consisting of Al, Au, Ag, Sn, Zn, and In, or an alloy containing at least one metal selected from the first group. Contains layers. The second electrode 140 is formed using, for example, a sputtering method, a vapor deposition method, or a coating method.

After that, a sealing member for sealing the organic layer 130 is provided on the substrate 110.

Note that although the organic substance 190 is illustrated as a layer in FIG. 2, the organic substance 190 is formed so thinly that it does not affect the electrical connection between the organic layer 130 and the first electrode 120. If the first electrode 120 is formed separately from the first terminal 150 and the first electrode 120 is electrically connected to the first terminal 150, the organic substance 190 may affect the electrical connection. It's so thin that it doesn't. Further, when the second electrode 140 is electrically connected to the second terminal 160, the organic substance 190 is thin enough not to affect the electrical connection.

As described above, at least one of the organic layers 130 is formed using a coating method. At this time, there is a possibility that the coating material spreads to the outside of the area surrounded by the insulating layer 170, for example, to the area overlapping with the first terminal 150, the second terminal 160, or the edge 182 of the sealing member 180, which will be described later. On the other hand, according to this embodiment, the organic substance 190 is attached to the surface of the inorganic material (for example, the first electrode 120 and the substrate 110) surrounding the edge layer 170 and the insulating layer 170. Therefore, the coating material that becomes the organic layer 130 is difficult to spread from the area surrounded by the insulating layer 170. Therefore, the shape of the outer periphery of the organic layer 130 can be controlled with high precision.

(Example 1)
3 and 4 are cross-sectional views showing a method of manufacturing the light emitting device 100 according to the first embodiment. First, as shown in FIG. 3A, a first electrode 120, a first terminal 150, a second terminal 160, and an insulating layer 170 are formed on a substrate 110. The method for forming these is as shown in the embodiment.

Next, a first layer 131 (for example, a hole injection layer or an electron injection layer) of the organic layer 130 is formed using a coating method. As the apparatus for applying the first layer 131, an apparatus that can control the application area with higher precision than the apparatus for applying the remaining layers of the organic layer 130 can be used.

Next, as shown in FIG. 3(b), the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. The details of the conditions of this step are the same as in the embodiment. As a result, the organic substance 190 adheres to the substrate 110 , the first terminal 150 , the insulating layer 170 , the region surrounding the insulating layer 170 of the first electrode 120 , and the second terminal 160 . The organic substance 190 may be attached on the first layer 131. In this case, the organic substance 190 is also present on the surface of the first layer 131 in the area surrounded by the insulating layer 170.

Next, as shown in FIG. 4(a), the remaining layers of the organic layer 130 are formed. At least one (or all) of the remaining layers are formed using a coating method. As the device used here, a device with lower precision than the device that applies the first layer 131 can be used. Regarding the coating devices corresponding to each of the first layer 131 and the remaining layers of the organic layer 130, only the coating device for forming the first layer 131 is a high-precision device, and the coating device for forming the remaining layers is a low-precision device. By using such a device, the cost of the entire manufacturing device can be reduced. Note that, as described above, the organic substance 190 may also adhere to the first layer 131. In this case, since the first layer 131 is formed of an organic material, a coating film can be formed by the coating material applied to the first layer 131 even if the organic substance 190 is attached. In other words, the first layer 131 has wettability. Therefore, when the remaining layers of the organic layer 130 are formed by a coating method, this coating material wets and spreads over the first layer 131, and the outside of the first layer 131 is wetted by the presence of the organic substance 190 in contact with the inorganic material. Difficult to spread. Furthermore, since the organic substance 190 is thin, it hardly affects the function of the organic layer 130.

Thereafter, as shown in FIG. 4(b), a second electrode 140 is formed. Furthermore, a sealing member 180 is provided. The sealing member 180 seals the stacked structure of the first electrode 120, the organic layer 130, and the second electrode 140, that is, the light emitting part. However, the first terminal 150 and the second terminal 160 are located outside the sealing member 180. In the example shown in this figure, the sealing member 180 has an airtight sealing structure, and the edge 182 (that is, the portion in contact with the substrate 110 side) is located outside the organic layer 130. Since the organic substance 190 is located at least in the region inside the edge 182, the layer formed of the coating material of the organic layer 130 is not located in the region overlapping the edge 182. Therefore, the sealing performance of the sealing member 180 is improved.

Note that although the organic substance 190 is illustrated as a layer in FIG. 4, the organic substance 190 is thin enough not to affect the function of the organic layer 130. If the first electrode 120 is formed separately from the first terminal 150 and the first electrode 120 is electrically connected to the first terminal 150, the organic substance 190 may affect the electrical connection. It's so thin that it doesn't. Further, when the second electrode 160 is electrically connected to the second terminal 160, the organic material 190 is thin enough not to affect the electrical connection.

According to this embodiment, after forming the first layer 131, the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. As a result, the organic substance 190 adheres to the substrate 110 , the first terminal 150 , the insulating layer 170 , the region surrounding the insulating layer 170 of the first electrode 120 , and the second terminal 160 . Therefore, even if at least one of the remaining layers of the organic layer 130 is formed by a coating method, the coating material can be prevented from spreading outside the insulating layer 170. On the other hand, as described above, it is possible to prevent the coating material from spreading to the region overlapping with the edge 182 on the outside of the insulating layer 170, so that good sealing performance can be obtained. Furthermore, the equipment used to form at least one of the remaining layers of organic layer 130 does not require high precision. This makes it possible to introduce a device with lower precision than other devices, so the manufacturing cost of the light emitting device 100 can be lowered.

Further, in this embodiment, the first layer 131 is formed before the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. Even if the organic substance 190 is attached to the first layer 131 formed of an organic material, the wettability of the coating material to the first layer 131 is considered to be good. Therefore, when an organic layer is formed on the first layer 131, the adhesion between this organic layer and the first layer 131 is considered to be good.

(Example 2)
FIG. 5 is a plan view of the light emitting device 100 according to the second embodiment. 6 is a diagram with the sealing member 180 removed from FIG. 5, FIG. 7 is a diagram with the second electrode 140 removed from FIG. 6, and FIG. 8 is a diagram with the organic layer 130 and the insulating layer 170 removed from FIG. This is a diagram with . Further, FIG. 9 is a diagram for explaining the relative position between the edge 182 of the sealing member 180 and the region where the organic substance 190 is located.

The light emitting device 100 is, for example, a polygon such as a rectangle, and includes an organic EL element 102, a first terminal 150, and a second terminal 160. The first terminal 150 and the second terminal 160 are provided to supply power to the organic EL element 102. In the examples shown in FIGS. 5 to 8, the first terminal 150 extends in a first direction (X direction in the figure), and the second terminal 160 extends in a second direction (Y direction in the figure). There is.

The organic EL element 102 has a structure in which a first electrode 120, an organic layer 130, and a second electrode 140 are laminated in this order on a substrate 110. In the example shown in this figure, light from the organic EL element 102 is emitted to the outside via the substrate 110 (bottom emission type).

The substrate 110 is, for example, a transparent substrate such as a glass substrate or a resin substrate. The substrate 110 may have flexibility. In this case, the thickness of the substrate 110 is, for example, 10 μm or more and 10,000 μm or less. Even in this case, the substrate 110 may be made of either an inorganic material or an organic material. The substrate 110 is, for example, a polygon such as a rectangle.

The first electrode 120 is a transparent electrode that functions as, for example, an anode of the organic EL element 102 and has light transmittance. The light emitted by the organic EL element 102 is emitted to the outside via the first electrode 120 and the substrate 110. The material of the transparent electrode includes, 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. The first electrode 120 is formed using, for example, a sputtering method or a vapor deposition method.

As shown in FIG. 7, an insulating layer 170 is formed on the first electrode 120. The insulating layer 170 is made of photosensitive resin such as polyimide. A first opening 172 is provided in the insulating layer 170. Then, an organic layer 130 is formed on a region of the first electrode 120 located inside the first opening 172 . Therefore, the first opening 172 defines the edge of the organic EL element 102.

The organic layer 130 has a light emitting layer. The organic layer 130 has, for example, a structure in which a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order. A hole injection layer may be formed between the first electrode 120 and the hole transport layer. Further, an electron injection layer may be formed between the electron transport layer and the second electrode 140. At least two layers of the organic layer 130 are formed by a coating method such as an inkjet method. The remaining layers of the organic layer 130 may be formed by an inkjet method using a coating material.

The second electrode 140 is a metal selected from the first group consisting of Al, Au, Ag, Pt, Sn, Zn, and In, or an alloy layer containing at least one metal selected from the first group. Contains. The second electrode 140 is formed using, for example, a sputtering method or a vapor deposition method. Since light is emitted from the region where the first electrode 120, the organic layer 130, and the second electrode 140 overlap, this region becomes the light emitting section 104.

Note that the second electrode 140 may be a transparent electrode and the first electrode 120 may be a metal electrode. In this case, the light of the organic EL element 102 is emitted from the surface opposite to the substrate 110 via the second electrode 140 (top emission type).

The first terminal 150 is connected to the first electrode 120 and the second terminal 160 is connected to the second electrode 140. In the examples shown in FIGS. 5 to 8, two first terminals 150 are arranged apart from each other in the second direction, and two second terminals 160 are arranged apart from each other in the first direction. There is.

The first terminal 150 has a structure in which a second layer 154 is laminated on the same layer as the first electrode 120. The second layer 154 is made of a material (for example, a metal such as Ag) that has a lower resistance value than the first electrode 120. A connecting member that supplies voltage to the first terminal 150 is connected to the second layer 154.

Further, the second terminal 160 has a structure in which a second layer 164 is laminated on the first layer. The first layer is made of the same material as the first electrode 120. However, the first layer is separated from the first electrode 120. The second layer 164 is made of the same material as the second layer 154.

Further, a plurality of auxiliary electrodes 124 are formed on the first electrode 120. The auxiliary electrode 124 is located within the organic EL element 102 and is made of a material (for example, a metal such as Ag) having a lower resistance value than the first electrode 120. By forming the auxiliary electrode 124, it is possible to suppress voltage drop from occurring within the plane of the first electrode 120. Thereby, it is possible to suppress the occurrence of a distribution in the brightness of the light emitting device 100. In the example shown in this figure, the auxiliary electrode 124 extends between the two first terminals 150 but is not directly connected to the second layer 154 of either of the two first terminals 150. However, the auxiliary electrode 124 may be directly connected to at least one of the two second layers 154.

Further, as shown in FIGS. 5 and 8, the plurality of organic EL elements 102 are sealed with a sealing member 180. The sealing member 180 has a shape in which an edge 182 of a polygonal metal foil or metal plate (for example, an Al foil or an Al plate) similar to the substrate 110 is downward toward the substrate 110 over the entire circumference. The edge 182 may be formed as a step. The edge portion 182 is fixed to the substrate 110 with an adhesive or the like. Note that the sealing member 180 may be made of glass.

A portion of the first terminal 150 and a portion of the second terminal 160 are located outside the sealing member 180. A conductive member is connected to a portion of the first terminal 150 located outside the sealing member 180 and a portion of the second terminal 160 located outside the sealing member 180. This conductive member is, for example, a lead frame or a bonding wire, and connects the first terminal 150 (or second terminal 160) to a circuit board or the like.

Next, a method for manufacturing the light emitting device 100 according to this example will be described. First, a conductive film that will become the first electrode 120 is formed on the substrate 110 using, for example, a vapor deposition method or a sputtering method. Next, a resist film is formed in a predetermined shape on this conductive film, and the conductive film is etched using this resist film as a mask. As a result, the first electrode 120 (including the first layer of the first terminal 150) and the first layer of the second terminal 160 are formed. After that, the resist pattern is removed.

Next, an auxiliary electrode 124 and second layers 154 and 164 are formed on the substrate 110.

Next, an insulating photosensitive material that will become the insulating layer 170 is formed on the first electrode 120 formed on the substrate 110 by, for example, a coating method. This insulating layer 170 is formed so as to surround the region where the organic layer 130 is formed. Next, this photosensitive material is exposed and developed. As a result, an insulating layer 170 and a first opening 172 are formed. Next, the organic layer 130 is formed within the first opening 172. When forming the organic layer 130, the method shown in the embodiment or Example 1 is applied.

After that, a second electrode 140 is formed on the organic layer 130 and the insulating layer 170 using a sputtering method. After that, a sealing member 180 is attached to the substrate 110.

As shown in FIG. 9, the organic matter 190 is formed at least in a region surrounded by the edge 182. In the example shown in the figure, the organic substance 190 is formed in a region of the first electrode 120 that will become the light emitting section 104 and a region located outside the insulating layer 170, as well as on the insulating layer 170. Therefore, the layer formed of the coating material in the organic layer 130 is difficult to wet and spread outside the insulating layer 170. Note that in FIG. 9, a gap is provided between the region where the organic substance 190 is formed and the edge 182 in order to make the diagram easier to read, but this gap does not need to exist.

In this embodiment, even if at least one of the remaining layers of the organic layer 130 is formed by a coating method, the coating material spreads outside the insulating layer 170 and overlaps the edge 182 of the sealing member 180. It is possible to suppress the spread of the coating material over the area.

Although the embodiments and examples have been described above with reference to the drawings, these are merely illustrative of the present invention, and various configurations other than those described above may be adopted.

100 Light emitting device 110 Substrate 116 Second electrode 120 First electrode 130 Organic layer 131 First layer 140 Second electrode 170 Insulating layer (structure)
190 Organic matter

Claims (3)

A substrate and
a first electrode located on the substrate;
a structure surrounding at least a portion of the first electrode;
an organic layer located on the first electrode and located at least partially inside the structure, and including a plurality of layers;
a second electrode located on the organic layer;
between a first layer located closest to the first electrode among the organic layers and a layer other than the first layer among the organic layers ; and a layer other than the first layer among the organic layers. and the surface of the structure, and an organic material that is not layered and has a siloxane bond, and is located between the top surface and the outside of the structure ;
A light emitting device comprising: The light emitting device according to claim 1,
A light emitting device in which the first layer is a coating film. The light emitting device according to claim 1 or 2,
In the light emitting device, a layer located closest to the first layer among the layers other than the first layer is a coating film.

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