JP2020031070A - Light-emitting device - Google Patents

Abstract

To control the planar shape of a layer with high accuracy, when forming at least one organic layer of a coating material.SOLUTION: After a first electrode 120 and an insulation layer 170 are formed on a substrate 110, the substrate 110 is exposed to an atmosphere containing an organic material having a siloxane bond. Consequently, an organic material 190 adheres onto the substrate 110 and first electrode 120. Thereafter, an organic layer 130 is formed. At least one layer (e.g., a hole injection layer or an electron injection layer) composing the organic layer 130 is formed using a coating method. Since the organic material 190 has a siloxane bond, it is difficult to be wetted by the coating material for forming the organic layer 130. Consequently, the coating material becoming the organic layer 130 is hard to spread from an area surrounded by the insulation layer 170.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light emitting device.

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

  Patent Literatures 1 and 2 disclose 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 that an opening is provided in an insulating layer and the inside of the opening is used as a light emitting portion. Patent Document 2 describes that the insulating layer may contain an organopolysiloxane.

JP-A-2002-170673 JP 2010-45050 A

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

  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 forming at least one of the organic layers with a coating material.

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

A second invention is a step of forming a structure surrounding a formation region of a coating film on a substrate;
A step of adhering an organic material having a siloxane bond to the inorganic material forming the substrate or the inorganic material on the substrate, surrounding the formation region of the coating film,
It is a manufacturing method of the light emitting device provided with.

FIG. 5 is a cross-sectional view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 5 is a cross-sectional view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 5 is a sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 5 is a sectional view illustrating the method for manufacturing the light emitting device according to the first embodiment. FIG. 6 is a plan view of a light emitting device according to a second embodiment. It is the figure which removed the sealing member from FIG. It is the figure which removed the 2nd electrode from FIG. It is the figure which removed the organic layer and the insulating layer from FIG. It is a figure for explaining the relative position of the edge part of a sealing member, and the field where an organic substance is located.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will not be repeated.

  1 and 2 are cross-sectional views illustrating a method for manufacturing the light emitting device 100 according to the embodiment. The light emitting device 100 is formed using a substrate 110. The substrate 110 is, for example, a glass substrate formed of an inorganic material such as glass, a substrate formed of a silicon oxide film on one surface of a member formed of glass, silicon nitride or a silicon nitride film formed on a surface of a member formed of a polyimide resin. Examples include a substrate on which a film (barrier film) made of an inorganic material such as silicon nitride oxide is formed, a substrate formed of a metal material such as aluminum, and the like, including a film or a member formed of an inorganic material. 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 formed of a resist is formed on the conductive film into a predetermined shape, and the resist film is used as a mask to wet-etch or dry-etch the conductive film using an organic solvent. Thus, 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 over the substrate 110 and the first electrode 120, and the insulating film is selectively removed. Thus, the 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, for example, and surrounds a region of the first electrode 120 where an organic layer 130 (described later) is formed. In addition, a part 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. These are all inorganic materials.

  Next, as shown in FIG. 1B, the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. The organic substance is, for example, a silicone-based organic substance, specifically, for example, trimethylsilane. The temperature of the atmosphere is, for example, 100 ° C. or more and 300 ° C. or less, and the concentration of the organic substance in the atmosphere is, for example, 1 ppm or more and 1000 ppm or less. The time for exposing the substrate 110 to the atmosphere is, for example, 1 minute or more and 60 minutes or less. Thus, 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 substance 190 is located on the surface of the inorganic material (for example, a material different from the first electrode 120, that is, the substrate 110) surrounding the insulating layer 170. The inorganic material is located closer to the substrate 110 than the organic substance 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 in which the organic substance 190 is located surrounds the entire periphery of the insulating layer 170. In other words, the organic substance 190 surrounds the entire circumference of the insulating layer 170. The organic substance 190 may or may not be in a layer. Not limited to this, the inorganic material may be formed around the insulating layer 170 or the organic layer 130 to scatter a plurality of inorganic materials, or may be formed around the entire circumference of the insulating layer 170 or the organic layer 130 to form a ring. May be disposed.
When the organic substance 190 is not in a layer, the molecules of the organic substance 190 are attached to the above-mentioned inorganic material at a predetermined density. When the organic material 190 is a layer, the thickness of the organic material 190 is thinner than any of the layers constituting the organic layer 130, for example, 1 nm or less. The organic substance 190 adheres to a region of the first electrode 120 outside the insulating layer 170, in other words, in a region located on the end 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. 2A, an organic layer 130 is formed. The organic layer 130 has a configuration in which a plurality of layers including a light emitting layer are stacked. The organic layer 130 has at least a hole injection layer, a light emitting layer, and an electron injection layer. Then, 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. Thereby, at least one layer constituting the organic layer 130 is formed of a coating film. By forming all layers of the organic layer 130 by a coating method, the organic layer 130 may be a coating film. Specific examples of a 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 includes an organic material for forming the organic layer 130 and an organic solvent. Here, an organic substance 190 is attached to surfaces of the insulating layer 170 and an inorganic material (for example, the first electrode 120 or the substrate 110) surrounding the insulating layer 170. Since the organic substance 190 has a siloxane bond, the organic substance 190 is not easily wetted by a coating material for forming the organic layer 130. Therefore, the coating material to be the organic layer 130 is unlikely to spread from the region surrounded by the insulating layer 170.

  Next, as shown in FIG. 2B, a second electrode 140 is formed on the organic layer 130. Part 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 a first group consisting of Al, Au, Ag, Sn, Zn, and In, or a metal made of an alloy containing at least one metal selected from the first group. Includes layers. The second electrode 140 is formed using, for example, a sputtering method, an evaporation method, or a coating method.

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

  Although the organic material 190 is shown in FIG. 2 as a layer, the organic material 190 is formed to be thin enough not to affect the electrical connection between the organic layer 130 and the first electrode 120. When 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 affects the electrical connection. Not too thin. When the second electrode 140 is electrically connected to the second terminal 160, the organic material 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, the coating material may spread to the outside of the region surrounded by the insulating layer 170, for example, to the region overlapping with the first terminal 150, the second terminal 160, or the edge 182 of the sealing member 180 described later. On the other hand, according to the present embodiment, the organic substance 190 is attached to the surface of the inorganic material (for example, the first electrode 120 or the substrate 110) surrounding the edge layer 170 and the insulating layer 170. Therefore, the coating material to be the organic layer 130 is unlikely to spread from the region surrounded by the insulating layer 170. Therefore, the shape of the outer peripheral portion of the organic layer 130 can be controlled with high accuracy.

(Example 1)
3 and 4 are cross-sectional views illustrating a method for 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. These forming methods are as described 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 an apparatus for applying the first layer 131, an apparatus capable of controlling the application area with higher precision than an apparatus for applying the remaining layer of the organic layer 130 can be used.

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

  Next, as shown in FIG. 4A, the remaining layer of the organic layer 130 is formed. At least one (or all) of the remaining layers is formed using a coating method. As a device used here, a device with lower accuracy than a device for applying the first layer 131 can be used. With respect to the coating devices corresponding to 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 a simple apparatus, the cost of the entire manufacturing apparatus can be reduced. Note that, as described above, the organic substance 190 may be attached to the first layer 131 in some cases. In this case, since the first layer 131 is formed of an organic material, a coating film can be formed using a coating material applied to the first layer 131 even when the organic substance 190 is attached. That is, the first layer 131 has wettability. Therefore, when the remaining layer of the organic layer 130 is formed by a coating method, this coating material spreads on the first layer 131 and spreads outside the first layer 131 due to the presence of the organic substance 190 in contact with the inorganic material. Difficult to spread. Further, since the organic material 190 is thin, it does not easily affect the function of the organic layer 130.

  Thereafter, as shown in FIG. 4B, a second electrode 140 is formed. Further, a sealing member 180 is provided. The sealing member 180 seals a stacked structure of the first electrode 120, the organic layer 130, and the second electrode 140, that is, a light emitting portion. 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 a hermetic 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 a region inside the edge portion 182, a layer formed of the coating material in the organic layer 130 is not located in a region overlapping with the edge portion 182. Therefore, the sealing performance of the sealing member 180 is improved.

  Although FIG. 4 shows the organic material 190 as a layer, the organic material 190 is thin enough not to affect the function of the organic layer 130. When 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 affects the electrical connection. Not too thin. 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. Thus, the organic substance 190 is attached to the substrate 110, the first terminal 150, the insulating layer 170, the region of the first electrode 120 surrounding the insulating layer 170, 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, it is possible to prevent the coating material from spreading outside the insulating layer 170. On the other hand, as described above, since the application material can be prevented from spreading to the region overlapping the edge portion 182 outside the insulating layer 170, good sealing performance can be obtained. In addition, a device used for forming at least one of the remaining layers of the organic layer 130 does not require high accuracy. This makes it possible to introduce a device with a lower accuracy than other devices, so that the manufacturing cost of the light emitting device 100 can be reduced.

  In this embodiment, the first layer 131 is formed before exposing the substrate 110 to an atmosphere containing an organic substance having a siloxane bond. It is considered that the wettability of the coating material with respect to the first layer 131 is good even when the organic substance 190 is attached to the first layer 131 formed of an organic material. Therefore, when an organic layer is formed on the first layer 131, it is considered that the adhesion between the organic layer and the first layer 131 is good.

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

  The light emitting device 100 is, for example, a polygon such as a rectangle, and has the organic EL element 102, the first terminal 150, and the second terminal 160. The first terminal 150 and the second terminal 160 are provided for supplying power to the organic EL element 102. In the example shown in FIGS. 5 to 8, the first terminal 150 extends in the first direction (X direction in the drawing), and the second terminal 160 extends in the second direction (Y direction in the drawing). Are there.

  The organic EL element 102 has a configuration in which a first electrode 120, an organic layer 130, and a second electrode 140 are laminated on a substrate 110 in this order. In the example shown in this figure, the light of the organic EL element 102 is radiated 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, not less than 10 μm and not more than 10,000 μm. Also in this case, the substrate 110 may be formed of any of an inorganic material and an organic material. The substrate 110 is, for example, a polygon such as a rectangle.

  The first electrode 120 is, for example, a transparent electrode that functions as an anode of the organic EL element 102 and has a light transmitting property. Light emitted by the organic EL element 102 is emitted outside through 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 an evaporation method.

  As shown in FIG. 7, an insulating layer 170 is formed on the first electrode 120. The insulating layer 170 is formed of a photosensitive resin such as polyimide. The first opening 172 is provided in the insulating layer 170. The organic layer 130 is formed on a region of the first electrode 120 located in 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 configuration in which 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 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 made of a metal selected from a 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 an evaporation method. Then, light is emitted from a region where the first electrode 120, the organic layer 130, and the second electrode 140 overlap, and this region serves as the light emitting unit 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, light from 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 example illustrated 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. I have.

  The first terminal 150 has a configuration in which the second layer 154 is stacked on the same layer as the first electrode 120. The second layer 154 is formed of a material (for example, a metal such as Ag) having a lower resistance value than the first electrode 120. The connection member that supplies a voltage to the first terminal 150 is connected to the second layer 154.

  The second terminal 160 has a configuration in which the second layer 164 is stacked on the first layer. The first layer is formed 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 formed 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 inside the organic EL element 102 and is formed of a material (for example, a metal such as Ag) having a lower resistance value than the first electrode 120. The formation of the auxiliary electrode 124 can suppress a voltage drop in the plane of the first electrode 120. Thereby, it is possible to suppress the occurrence of distribution in the luminance 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 any of the second layers 154 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.

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

  A part of the first terminal 150 and a part 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 the second terminal 160) to a circuit board or the like.

  Next, a method for manufacturing the light emitting device 100 according to the present embodiment will be described. First, a conductive film to be the first electrode 120 is formed over the substrate 110 by using, for example, an evaporation method or a sputtering method. Next, a resist film is formed in a predetermined shape on the conductive film, and the conductive film is etched using the resist film as a mask. Thereby, 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, the auxiliary electrode 124 and the second layers 154 and 164 are formed on the substrate 110.

  Next, an insulating photosensitive material to be 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 a region where the organic layer 130 is formed. Next, the photosensitive material is exposed and developed. Thereby, the insulating layer 170 and the first opening 172 are formed. Next, the organic layer 130 is formed in the first opening 172. When the organic layer 130 is formed, the method described in the embodiment or Example 1 is applied.

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

  Then, as shown in FIG. 9, the organic substance 190 is formed at least in a region surrounded by the edge 182. In the example shown in this figure, the organic substance 190 is also formed on the region of the first electrode 120 that is to be the light emitting portion 104, the region located outside the insulating layer 170, and on the insulating layer 170. For this reason, the layer formed of the coating material in the organic layer 130 does not easily spread outside the insulating layer 170. In FIG. 9, a gap is provided between the region where the organic substance 190 is formed and the edge portion 182 in order to make the drawing easy to see, but this gap may not be present.

  According to this embodiment, even if at least one of the remaining layers of the organic layer 130 is formed by the coating method, the coating material spreads outside the insulating layer 170 and overlaps with the edge 182 of the sealing member 180. Spreading of the coating material to the region can be suppressed.

  As described above, the embodiments and examples have been described with reference to the drawings. However, these are examples of the present invention, and various configurations other than those described above can be adopted.

Reference Signs List 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 (1)

Board and
A structure formed on the substrate and surrounding the coating film;
An organic material having a siloxane bond,
With
The organic material having a siloxane bond is in contact with the inorganic material forming the substrate or the inorganic material on the substrate,
The light emitting device, wherein the inorganic material is in a region surrounding the structure.

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