JP2016046165A - Method of manufacturing light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the planar shape of a layer with high accuracy, when forming at least one organic layer by a coating method.SOLUTION: After a first electrode 120 and an insulation layer 170 are formed on a substrate 110, the area of the substrate 110 for forming an organic layer 130 is covered with a mask. Subsequently, the substrate 110 is exposed to an atmosphere containing an organic material having siloxane bond. Consequently, an organic material 190 adheres to an area surrounding the area of the substrate 110 and first electrode 120 for forming an organic layer 130. Furthermore, since an insulation layer 170 is formed on the inside of the mask, the organic material 190 is difficult to enter the inside of the mask. Thereafter, the mask is removed, and the 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.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a light emitting device.

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

  Patent Documents 1 and 2 describe that an organic layer of an organic EL element is formed into a predetermined shape by patterning using a photolithography method. In particular, Patent Document 2 describes that an opening is provided in an insulating layer so that the inside of the opening becomes a light emitting portion. Patent Document 2 describes that the insulating layer may contain an organopolysiloxane.

JP 2002-170673 A JP 2010-45050 A

  In recent years, it has been studied to form at least one organic layer of an organic EL element with a coating film using a coating method. On the other hand, when forming at least one layer of an organic layer with a coating film, it is difficult to control the shape of the outer peripheral part of this coating film with high precision.

  An example of a problem to be solved by the present invention is to control the shape of the outer peripheral portion of the coating film with high accuracy when at least one organic layer is formed by a coating method.

The invention according to claim 1 is a step of forming an open structure;
A step of covering a region where a coating film is formed with a mask member that covers an opening of the structure, and a step of covering the region with the structure;
Attaching an organic material to a region of the substrate located outside the structure;
Removing the mask member from the substrate;
A method for manufacturing a light emitting device comprising:

It is sectional drawing which shows the manufacturing method of the light-emitting device which concerns on embodiment. It is sectional drawing which shows the manufacturing method of the light-emitting device which concerns on embodiment. It is sectional drawing which shows the manufacturing method of the light-emitting device which concerns on a modification. It is a top view of the light-emitting device concerning an example. 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 demonstrating the position of a mask member. It is a figure for demonstrating the relative position of the edge part of a sealing member, and a mask member.

  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.

  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 includes, for example, a glass substrate formed of an inorganic material such as glass, a substrate in which a silicon oxide film is formed on one surface of a member formed of glass, silicon nitride on a surface of a member formed of polyimide resin, or Examples thereof 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, and has a film or 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. For this reason, the “surface of the substrate 110” does not include the surface of the film formed on the substrate 110.

  First, as illustrated 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 over the conductive film in a predetermined shape, and the conductive film is etched using the resist film as a mask. Thereby, the first electrode 120, the first terminal 150, and the second terminal 160 having a predetermined shape are formed. In the example shown in the 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. Thereby, the insulating layer 170 (an example of a structure) is formed on the first electrode 120. The insulating layer 170 is formed using, for example, a photosensitive resin such as polyimide, and surrounds a region of the first electrode 120 where an organic layer 130 (described later) is formed. 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, the second terminal 160, or the substrate 110 itself is located on the surface of the region surrounding the insulating layer 170 in the substrate 110. These are all inorganic materials.

  Next, as illustrated in FIG. 1B, a mask 200 is disposed on the substrate 110. The mask 200 covers a region surrounded by the insulating layer 170 in the substrate 110, that is, a region where an organic layer 130 (described later) is formed and the insulating layer 170. In this state, the first electrode 120, the first terminal 150, the second terminal 160, or the substrate 110 itself is located on the surface of the region surrounding the mask 200 in the substrate 110. These are all inorganic materials.

  The mask 200 is a mask member formed of a metal such as stainless steel. In the example shown in FIG. 8, the substrate 110 and the mask member 200 disposed on the substrate 110 have an open shape, and include four outer peripheral side surfaces 202 and a top surface portion 204 connected to the outer peripheral side surface 202. . A space having an open bottom is formed by the outer peripheral side surface 202 and the top surface portion 204. In addition, when applied to the embodiments described later, structures (insulating layer 170, first electrode 120, second electrode 140, first terminal 150, and second terminal 160) on mask member 200 and substrate 110, and The positional relationship with the edge 182 of the sealing member 180 is as shown in FIG. In the positional relationship between the structure on the mask member 200 and the substrate 110 shown in FIG. 9, the outer peripheral side surface 202 of the mask member 200 is located outside the insulating layer 170 and arranged inside the edge 182. Further, the top surface portion 204 of the mask member 200 is disposed in a region where the organic layer is formed (on the first electrode 120).

  The mask 200 may be a film processed into a predetermined shape. In this case, the mask 200 is formed of a photosensitive material such as polyimide, a resin such as a thermoplastic resin, a thermosetting resin, or a photocurable resin, and is formed in advance by, for example, a spin coating method or an inkjet method. It is formed using a resin film. The pattern of the mask 200 is formed in a predetermined shape so as to cover a region where the organic layer 130 is formed by photolithography, for example, when a spin coating method is used. In the case of forming the mask 200 using the inkjet method, a coating material is dropped so as to cover a region where the organic layer 130 is formed, and a coating film is formed into a predetermined shape. To do. When the mask 200 is formed using a resin film formed in advance, a resin film is bonded to a region of the substrate 110 where the organic layer 130 is formed, and the resin film is used as the mask 200.

  In the example shown in this figure, the entire periphery of the edge of the mask 200 is located outside the insulating layer 170 and is in contact with the substrate 110 or a structure (for example, the first electrode 120) on the substrate 110. On the other hand, a predetermined gap is provided between the top surface portion 204, which is another part of the mask 200, and the substrate 110 or the above-described structure, and the other part of the mask 200 is the substrate 110 or the above-described structure. Not touching. In this way, it is possible to suppress foreign matter from adhering to the substrate 110 and the first electrode 120 via the mask 200. The mask 200 has, for example, a shape in which the lower surface is recessed except for the edge as shown in FIG. However, the shape of the mask 200 is not limited to the example shown in this figure. Further, in this figure, the region located on the first electrode 120 in the edge of the mask 200 is shorter than the portion located on the substrate 110 in the edge of the mask 200. However, since the first electrode 120 is sufficiently thin with respect to the thickness of the mask 200, the height of the edge of the mask 200 may be the same over the entire circumference.

  Next, the substrate 110 is exposed to an atmosphere containing an organic substance having a siloxane bond. As this organic substance, for example, a silicone-based organic substance, specifically, for example, trimethylsilane. Moreover, the temperature of atmosphere is 100 degreeC or more and 300 degrees C or less, for example, and the density | concentration of the organic substance in atmosphere is 1 ppm or more and 1000 ppm or less, for example. The time for exposing the substrate 110 to the atmosphere is, for example, 1 minute to 60 minutes. As a result, the organic substance 190 (organic material) adheres to the substrate 110, the first terminal 150, the region surrounding the mask 200 in the region surrounding the insulating layer 170, and the second terminal 160. . In other words, the organic substance 190 is located on the surface of an inorganic material (for example, a material different from the first electrode 120, that is, the substrate 110) surrounding the mask 200. The inorganic material in which the organic material 190 is located is located on the substrate 110 side of the organic material 190 in the thickness direction, and the organic material 190 having a siloxane bond is formed on the inorganic material or the substrate 110 on which the substrate 110 is formed. It is in contact with an inorganic material.

  The inorganic material in which the organic material 190 is located surrounds the entire circumference of the mask 200. In other words, the organic material 190 surrounds the entire periphery of the insulating layer 170. The inorganic material is not limited to this, and the inorganic material is formed around the insulating layer 170 or the organic layer 130 so as to be dotted with a plurality of inorganic materials, or is formed so as to surround the entire circumference of the insulating layer 170 or the organic layer 130. The inorganic material may be arranged. The organic material 190 may be a layer or may not be a layer. When the organic substance 190 is not 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 smaller than the thickness of any layer constituting the organic layer 130, for example, 1 nm or less. 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.

  In addition, the organic substance 190 may enter the inside of the mask 200 through the gap between the mask 200 and the substrate 110 (or the first electrode 120). On the other hand, in this embodiment, the insulating layer 170 is formed inside the mask 200. The insulating layer 170 surrounds a region where the organic layer 130 is to be formed. Accordingly, it is possible to suppress the organic material 190 from adhering to the region where the organic layer 130 is to be formed in the first electrode 120. In the example shown in this figure, the inner surface of the edge of the mask 200 and the side surface of the insulating layer 170 are in contact, but a gap may be provided between them.

  Next, as shown in FIG. 2A, the mask 200 is removed. When the mask 200 is a film, the mask 200 is peeled from the substrate 110 to expose a region where the organic layer 130 is formed. As a method for removing the film as the mask 200, a known method such as a lift-off method can be employed. Next, the 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 the coating film. The organic layer 130 may be a coating film by applying all the layers of the organic layer 130 by a coating method. Specific examples of the coating film forming method (coating method) using the coating material include, for example, an ink jet method and a dispenser method. The coating material is composed of an organic material that forms the organic layer 130 and an organic solvent. Here, an organic substance 190 is attached to the surface of an inorganic material (for example, the first electrode 120 or the substrate 110) surrounding the insulating layer 170. Since the organic material 190 has a siloxane bond, it is difficult to wet the coating material for forming the organic layer 130. For this reason, the coating material used as the organic layer 130 is difficult to spread from the region surrounded by the insulating layer 170.

  Next, as illustrated in FIG. 2B, the second electrode 140 is formed on the organic layer 130. A 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 the first group consisting of Al, Au, Ag, Pt, Sn, Zn, and In, or an alloy containing at least one metal selected from the first group. Contains a metal layer. The second electrode 140 is formed using, for example, a sputtering method, a vapor deposition method, or a coating method.

  Thereafter, a sealing member 180 that seals the organic layer 130 is provided on the substrate 110. 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 unit. 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. In addition, since the organic material 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 by the sealing member 180 is improved.

  In FIG. 2, the organic substance 190 is illustrated as a layer, but the organic substance 190 is formed 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 material 190 affects the electrical connection. It's thin enough. Further, 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, there is a possibility that the coating material may spread to the outside of the region surrounded by the insulating layer 170, for example, the region overlapping 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 insulating layer 170. For this reason, the coating material used as the organic layer 130 is difficult to spread from the region surrounded by the insulating layer 170. Accordingly, the shape of the outer peripheral portion of the organic layer 130 can be controlled with high accuracy. In addition, as described above, since the coating material can be prevented from spreading in a region overlapping with the edge portion 182 outside the insulating layer 170, good sealing performance can be obtained.

  In the step of attaching the organic material 190 to the substrate 110, an insulating layer 170 is formed inside the mask 200. The insulating layer 170 surrounds a region where the organic layer 130 is to be formed. Therefore, even if the organic material 190 enters from the interface between the mask 200 and the first electrode 120 (or the substrate 110), the organic material 190 is prevented from adhering to the region of the first electrode 120 where the organic layer 130 is to be formed. it can. In particular, when the inner surface of the edge of the mask 200 and the side surface of the insulating layer 170 are in contact with each other, the organic material 190 is more difficult to adhere to a region of the first electrode 120 where the organic layer 130 is to be formed.

  In the above description, the case where the substrate 110 is formed of an inorganic material has been described, but the substrate 110 may be formed of a resin.

(Modification)
FIG. 3 is a cross-sectional view illustrating a method for manufacturing the light emitting device 100 according to a modification, and corresponds to FIG. 1B in the embodiment. The manufacturing method of the light emitting device 100 according to this modification has the same configuration as that of the light emitting device 100 according to the embodiment except that at least a part of the lower end of the edge of the mask 200 is positioned on the insulating layer 170. is there.

  Also according to this modification, the coating material to be the organic layer 130 is difficult to spread from the region surrounded by the insulating layer 170. Therefore, the planar shape of the organic layer 130 can be controlled with high accuracy. Further, since the lower surface of the edge of the mask 200 is in contact with the insulating layer 170, it is difficult to form a gap between the mask 200 and the insulating layer 170. Therefore, the organic material 190 is less likely to adhere to a region of the first electrode 120 where the organic layer 130 is to be formed.

  FIG. 4 is a plan view of the light emitting device 100 according to the embodiment. 5 is a view in which the sealing member 180 is removed from FIG. 4, FIG. 6 is a view in which the second electrode 140 is removed from FIG. 5, and FIG. 7 is a view in which the organic layer 130 and the insulating layer 170 are removed from FIG. FIG.

  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. 4 to 7, the first terminal 150 extends in the first direction (X direction in the figure), and the second terminal 160 extends in the second direction (Y direction in the figure). Exist.

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

  The substrate 110 is 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 10000 μm. Also in this case, the substrate 110 may be formed of either an inorganic material or an organic material. The substrate 110 has a polygonal shape 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 light transmittance. The light emitted from the organic EL element 102 is emitted to the 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 a vapor deposition method.

  As shown in FIG. 6, an insulating layer 170 is formed on the first electrode 120. The insulating layer 170 is made of a photosensitive resin such as polyimide. A first opening 172 is provided in the insulating layer 170. An organic layer 130 is formed on a region of the first electrode 120 located in the first opening 172. For this reason, 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 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 first electrode 120 and the hole transport layer. In addition, an electron injection layer may be formed between the electron transport layer and the second electrode 140. At least one layer of the organic layer 130 is formed by a coating method such as an inkjet method. The remaining layers of the organic layer 130 are formed by vapor deposition. Note that all 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. Is included. The second electrode 140 is formed using, for example, a sputtering method or a vapor deposition method. Since light is emitted from a region where the first electrode 120, the organic layer 130, and the second electrode 140 overlap, this region becomes the light emitting unit 104.

  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 radiated from the surface opposite to the substrate 110 through 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 shown in FIGS. 4 to 7, the two first terminals 150 are arranged apart from each other in the second direction, and the two second terminals 160 are arranged apart from each other in the first direction. Yes.

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

  A plurality of auxiliary electrodes 124 are formed on the first electrode 120. The auxiliary electrode 124 is located in the organic EL element 102 and is made of a material having a lower resistance value than the first electrode 120 (for example, a metal such as Ag). By forming the auxiliary electrode 124, it is possible to suppress a voltage drop from occurring in the plane of the first electrode 120. Thereby, it can suppress that distribution arises in the brightness | luminance of the light-emitting device 100. FIG. In the example shown in the drawing, 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.

  As shown in FIGS. 4 and 7, the plurality of organic EL elements 102 are sealed with a sealing member 180. The sealing member 180 has a shape that is lowered toward the substrate 110 over the entire periphery of the edge 182 of a polygonal metal foil or metal plate (for example, an Al foil or an Al plate) similar to the substrate 110. The edge portion 182 may be formed as a stepped portion. The edge 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 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. The 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 this example will be described. First, a conductive film to be the first electrode 120 is formed on the substrate 110 by using, for example, a vapor deposition 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. Thus, the first electrode 120 (including the first layer of the first terminal 150) and the first layer of the second terminal 160 are formed. Thereafter, 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 by, for example, a coating method. 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 forming the organic layer 130, the method shown in the embodiment or the modification is applied.

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

  Even in this embodiment, even when at least one of the remaining layers of the organic layer 130 is formed by a coating method, it is possible to suppress the coating material from spreading outside the insulating layer 170.

  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.

100 Light-emitting device 110 Substrate 120 First electrode 130 Organic layer 140 Second electrode 170 Insulating layer (structure)
190 Organic 200 Mask

Claims (6)

Forming an open structure on the substrate;
A step of covering a region where a coating film is formed with a mask member covering the opening of the structure and the structure;
Attaching an organic material to a region of the substrate located outside the structure;
Removing the mask member from the substrate;
A method for manufacturing a light emitting device. In the manufacturing method of the light-emitting device according to claim 1,
A method for manufacturing a light emitting device, comprising a step of forming a coating film inside the structure. In the manufacturing method of the light-emitting device of Claim 1 or 2,
The organic material is a method for manufacturing a light emitting device having a siloxane bond. In the manufacturing method of the light-emitting device as described in any one of Claims 1-3,
In the step of attaching the organic material, in the region of the substrate surrounding the structure, there is an inorganic material that forms the substrate or an inorganic material on the substrate, and light emission that attaches the organic material to the inorganic material. Device manufacturing method. In the manufacturing method of the light-emitting device as described in any one of Claims 1-4,
A method of manufacturing a light emitting device in which the mask member is open. In the manufacturing method of the light-emitting device as described in any one of Claims 1-5,
A method for manufacturing a light emitting device, wherein, in the step of attaching the organic material, the organic material is attached thinner than the coating film.

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