JP2018137084A - Organic el display device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL display device capable of suppressing emission unevenness and a method of manufacturing the same.SOLUTION: A method of manufacturing an organic EL display device 1 includes: preparing a first barrier film 10 on which a transparent electrode 14 is formed; forming a protective film 3 in a non-forming region 6 outside a forming region 5 where an auxiliary electrode 20 is formed on the transparent electrode 14; forming a precursor film 205 of the auxiliary electrode 20 at least in the forming region 5 and on the protective film 3; processing the precursor film 205 to form the auxiliary electrode 20 in the forming region 5; and removing the protective film 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an organic EL display device and a manufacturing method thereof.

  As a conventional technique, an organic EL (Electro Luminescence) light emitting device including a transparent electrode film, an auxiliary electrode provided on the transparent electrode film, a positive electrode contact portion, an organic light emitting layer, and a negative electrode film is known (for example, (See Patent Document 1).

  The auxiliary electrode of the organic EL light emitting device is formed by performing photo-etching into an arbitrary shape after being formed with a metal material, and is electrically connected to the positive electrode contact portion through the transparent electrode film.

Japanese Unexamined Patent Publication No. 2016-26376

  However, in the conventional organic EL light-emitting device, the surface of the transparent electrode film is eroded by etching, and the flatness of the electrode is impaired, and light emission unevenness may occur.

  Accordingly, an object of the present invention is to provide an organic EL display device capable of suppressing light emission unevenness and a method for manufacturing the same.

  According to one embodiment of the present invention, a substrate on which a transparent electrode is formed is prepared, a protective film is formed on a non-formation region outside a formation region where an auxiliary electrode is formed over the transparent electrode, and at least on the formation region and the protection film Provided is a method for manufacturing an organic EL display device in which a precursor film of an auxiliary electrode is formed, the precursor film is processed to form an auxiliary electrode in a formation region, and a protective film is removed.

  According to the present invention, light emission unevenness can be suppressed.

FIG. 1 is a cross-sectional view of an essential part showing an example of an organic EL display device according to an embodiment. FIG. 2A to FIG. 2D are schematic views illustrating an example of a method for manufacturing an organic EL display device according to the embodiment.

(Summary of embodiment)
A method of manufacturing an organic EL display device according to an embodiment includes preparing a substrate on which a transparent electrode is formed, forming a protective film on a non-formation region outside a formation region on which an auxiliary electrode is formed on the transparent electrode, The method includes forming a precursor film of an auxiliary electrode on the formation region and the protective film, processing the precursor film to form an auxiliary electrode in the formation region, and removing the protective film.

  In this method of manufacturing an organic EL display device, when the auxiliary electrode is processed, the transparent electrode in the non-formation region where the auxiliary electrode is not formed is protected with a protective film. Erosion of the transparent electrode exposed in the formation region is suppressed, and uneven light emission can be suppressed.

[Embodiment]
(Outline of organic EL display device 1)
FIG. 1 is a cross-sectional view of an essential part showing an example of an organic EL display device according to an embodiment. FIG. 2A to FIG. 2D are schematic views illustrating an example of a method for manufacturing an organic EL display device according to the embodiment. Note that, in each drawing according to the embodiment described below, the ratio between figures may be different from the actual ratio.

  The organic EL display device 1 is formed of, for example, a flexible material and has flexibility so that it can be used in a bent state.

  For example, as shown in FIG. 1, the organic EL display device 1 includes a first barrier film 10 as a substrate, a transparent electrode 14 as a first electrode provided on the first barrier film 10, and a transparent An organic light emitting layer 16 provided on the electrode 14, an upper electrode 18 as a second electrode provided on the organic light emitting layer 16, a side surface having a tapered shape, provided on the transparent electrode 14, and transparent An auxiliary electrode 20 electrically connected to the electrode 14 is schematically provided.

  The auxiliary electrode 20 is formed so as to sandwich the organic light emitting layer 16. The above-described side surface is the side surface 200 on the organic light emitting layer 16 side, and this side surface 200 has a tapered shape. A plurality of auxiliary electrodes 20 may be formed, for example, or may be formed so as to surround the organic light emitting layer 16.

  As a modification, the substrate is not limited to the first barrier film 10, and may be, for example, a transparent resin that transmits light.

(Configuration of the first barrier film 10 and the second barrier film 12)
The 1st barrier film 10 and the 2nd barrier film 12 are comprised so that it may have gas barrier property which suppresses the penetration | invasion of the liquid and gas from the outside, for example. Since the first barrier film 10 and the second barrier film 12 are rich in flexibility, the organic EL display device 1 has high flexibility. The first barrier film 10 and the second barrier film 12 are formed using the same transparent material that transmits the light output from the organic light emitting layer 16.

  The first barrier film 10 and the second barrier film 12 include, for example, a core film and a gas barrier layer provided on the core film. The first barrier film 10 and the second barrier film 12 are bonded so that the gas barrier layers face each other.

  As an example, the core film is formed into a film shape using PET (polyethyleneterephtalate), PEN (polyethylene naphthalate), or the like.

  For example, the gas barrier layer is formed by alternately laminating inorganic materials and organic materials. As an example of the inorganic material, an oxide or nitride of Si or Al, an oxide of Zn or Sn, or the like is used. As an example of the organic material, a thermosetting resin material such as an epoxy resin or a silicon resin is used.

  In addition, the thickness of a core material film or a gas barrier layer is arbitrary.

(Configuration of transparent electrode 14 and upper electrode 18)
One of the transparent electrode 14 and the upper electrode 18 is an anode, and the other is a cathode. In the present embodiment, it is assumed that the transparent electrode 14 is an anode and the upper electrode 18 is a cathode. Since the transparent electrode 14 transmits light, the light generated by the organic light emitting layer 16 is output to the lower side in FIG. 1, that is, through the first barrier film 10 and the transparent electrode 14. The anode is for injecting holes into the organic light emitting layer 16. The cathode is for injecting electrons into the organic light emitting layer 16.

  The transparent electrode 14 is formed of ITO (Indium Tin Oxide) or the like that transmits light output from the organic light emitting layer 16 by, for example, vacuum deposition or sputtering.

  The upper electrode 18 is formed of a material that reflects light in order to increase the extraction efficiency of light output from the organic light emitting layer 16. The upper electrode 18 is formed using a metal material such as Al, Ag, Mg, or an alloy material thereof, for example, by a vacuum deposition method or the like. The upper electrode 18 may be ITO, which is a transparent electrode, for example.

  The thickness of the transparent electrode 14 and the upper electrode 18 is arbitrary.

(Configuration of the organic light emitting layer 16)
For example, the organic light emitting layer 16 is formed by laminating at least a hole transport layer, a light emitting layer, and an electron transport layer in order from the anode (transparent electrode 14) side. The hole transport layer is formed using, for example, α-NPD (diphenylnaphthyldiamine) or TPD (Triphenyl Diamine). The light emitting layer is formed using, for example, an aluminum quinolinol complex (Alq ₃ ) or a beryllium quinolinol complex (BeBq ₂ ). The electron transport layer is formed using, for example, an aluminum quinolinol complex.

  The organic light emitting layer 16 is formed by, for example, a coating method or a printing method. The thickness of the organic light emitting layer 16 is arbitrary.

(Configuration of auxiliary electrode 20)
Since the organic EL display device 1 cannot sufficiently heat-crystallize, that is, anneal, the transparent electrode 14 due to the heat resistance limitation of the first barrier film 10, the transparent electrode 14 becomes a high-resistance conductive film. When the transparent electrode 14 has a high resistance, the power consumption of the organic EL display device 1 increases. Therefore, the auxiliary electrode 20 is provided so as to be electrically connected to the transparent electrode 14 in order to reduce the resistance value.

  The auxiliary electrode 20 is formed using, for example, a metal material or an alloy material having a resistance value lower than that of the transparent electrode 14. As the auxiliary electrode 20, for example, Cr, Mo—Nd, Mo—Al—Mo (MAM: laminated composite material), or the like is used.

  In the present embodiment, as an example, MAM is used as the material of the auxiliary electrode 20. Since this MAM is non-transparent, it is preferable that the organic light emitting layer 16 is formed, that is, it is not disposed on the optical path of the light output from the organic light emitting layer 16. Therefore, the auxiliary electrode 20 is formed on the transparent electrode 14 around the organic light emitting layer 16.

  This MAM requires a strong corrosive etchant during etching. Therefore, when the MAM is etched, if the surface of the transparent electrode is eroded by the etching solution, the flatness is impaired. And when the flatness of a transparent electrode is impaired, the light output from the organic light emitting layer is scattered and causes uneven light emission. In addition, when a sacrificial layer that protects the transparent electrode by etching itself is provided on the transparent electrode, if the sacrificial layer remains on the transparent electrode 14, resistance uniformity, transparency, and flatness of the transparent electrode 14 are impaired.

  In the manufacturing method of the organic EL display device 1 of the present embodiment, as will be described later, the precursor film of the auxiliary electrode 20 can be etched without using the sacrificial layer and exposing the transparent electrode 14. ing.

  The auxiliary electrode 20 is formed in the formation region 5 described later on the transparent electrode 14. The organic light emitting layer 16 is formed in a non-formation region 6 described later on the transparent electrode 14. The thickness of the auxiliary electrode 20 is arbitrary.

(Configuration of insulating film 22)
The insulating film 22 protects the organic light emitting layer 16 by insulating the transparent electrode 14 from the upper electrode 18 and preventing liquid or gas from entering the organic light emitting layer 16. For example, when the insulating film 22 is formed using an organic insulating material such as polyimide, a coating method or a printing method is used. When the insulating film 22 is silicon dioxide or silicon nitride, for example, a sputtering method or a CVD (chemical vapor deposition) method Etc. are used. The thickness of the insulating film 22 is arbitrary.

  For example, as shown in FIG. 1, the insulating film 22 is also formed on the transparent electrode 14. Since the auxiliary electrode 20 and the organic light emitting layer 16 are formed to be insulated, a side surface 220 having a reverse taper shape corresponding to the side surface 200 of the auxiliary electrode 20 is provided. The character displayed by the organic EL display device 1 has a negative shape of the insulating film 22.

(Configuration of adhesive layer 24)
The adhesive layer 24 is a layer formed by curing the adhesive used when bonding the first barrier film 10 and the second barrier film 12 together. The adhesive layer 24 is formed of, for example, an epoxy or acrylic adhesive. The thickness of the adhesive layer 24 is arbitrary.

  Hereinafter, the formation of the auxiliary electrode 20 will be mainly described with reference to FIGS. 2A to 2D for an example of a method for manufacturing the organic EL display device 1 of the first embodiment.

(Manufacturing method of the organic EL display device 1)
The manufacturing method of the organic EL display device 1 prepares the first barrier film 10 on which the transparent electrode 14 is formed, and protects the non-forming region 6 outside the forming region 5 on which the auxiliary electrode 20 is formed on the transparent electrode 14. The film 3 is formed, the precursor film 205 of the auxiliary electrode 20 is formed on at least the formation region 5 and the protective film 3, the precursor film 205 is processed to form the auxiliary electrode 20 in the formation region 5, and the protective film 3 Including removing.

  First, the first barrier film 10 on which the transparent electrode 14 is formed is prepared. Specifically, a precursor film of the transparent electrode 14 is formed on the first barrier film 10 by a vacuum deposition method. Subsequently, the precursor film is processed into a desired shape by photolithography.

  The transparent electrode 14 may be crystallized by annealing within the heat-resistant temperature range of the first barrier film 10. The transparent electrode 14 may be patterned.

  Next, as shown in FIG. 2A, the protective film 3 is formed on the transparent electrode 14 in the non-formation region 6 outside the formation region 5 where the auxiliary electrode 20 is formed. This non-formation region 6 is a region where the protective film 3 is formed.

  The protective film 3 is formed as a resist film or a metal film having etching resistance different from that of the auxiliary electrode 20. Specifically, the protective film 3 is a material that can cover the transparent electrode 14, and is formed of a material that can be peeled or dissolved without affecting the transparent electrode 14 or the auxiliary electrode 20. Furthermore, the protective film 3 does not have to be covered with the precursor film 205 of the auxiliary electrode 20 normally, and does not require an affinity with the precursor film 205, that is, a high degree of adhesion.

  The protective film 3 of the present embodiment is formed as a resist film that is an etching mask for the transparent electrode 14. For example, the protective film 3 preferably has a thickness that is twice or more the thickness of the auxiliary electrode 20. This is because when the precursor film 205 of the auxiliary electrode 20 is etched, the side surface 200 of the precursor film 205 in contact with the protective film 3 may be etched if the thickness of the protective film 3 is thin.

  As a modification, the protective film 3 can be coated on the transparent electrode 14, is resistant to the etching solution used for processing the precursor film 205 of the auxiliary electrode 20, and does not affect the transparent electrode 14 and the auxiliary electrode 20. If it is a material that can be peeled off or dissolved, it is preferable to use a material for the etching mask of the precursor film 205. When the material is used, the protective film 3 has a sufficient thickness, so that the transparent electrode 14 can be prevented from being exposed by etching when the precursor film 205 is processed.

  The protective film 3 is formed so that the side surface 30 on the non-formation region 6 side has an inversely tapered shape. Since the side surface 30 of the side surface 30 has an inversely tapered shape, etching of the side surface 200 of the precursor film 205 can be suppressed. Since the side surface 30 of the protective film 3 has a reverse taper shape, the side surface 200 of the auxiliary electrode 20 has a taper shape. The protective film 3 is desirably formed in a reverse taper shape, but may not be formed if the adhesion between the protective film 3 and the precursor film 205 of the auxiliary electrode 20 is high.

  Next, as shown in FIG. 2B, a precursor film 205 of the auxiliary electrode 20 is formed at least on the formation region 5 and the protective film 3. Specifically, a precursor film 205 that is a MAM film is formed on the transparent electrode 14, the protective film 3, and the first barrier film 10 in the formation region 5 by sputtering.

  Next, as shown in FIG. 2C, the precursor film 205 is processed to form the auxiliary electrode 20 in the formation region 5. Specifically, a resist film is formed in the formation region 5 by a photolithography method, and the precursor film 205 on the non-formation region 6 and the first barrier film 10 is removed by an etching method.

  When the protective film 3 is a metal film, as described above, the protective film 3 is a film that is resistant to an etching solution used when the precursor film 205 is etched. The auxiliary electrode 20 is a film that is resistant to an etchant used when the protective film 3 is etched.

  Next, as shown in FIG. 2D, the protective film 3 is removed. As a modification, the protective film 3 may be removed together with the removal of the etching mask used when the auxiliary electrode 20 is processed when the protective film 3 is made of the same material as the etching mask of the precursor film 205.

  Next, the 1st barrier film 10 and the 2nd barrier film 12 in which the insulating film 22, the organic light emitting layer 16, and the upper electrode 18 were formed are bonded together with an adhesive agent, and the organic EL display device 1 is obtained.

(Effect of embodiment)
The organic EL display device 1 according to the present embodiment can suppress uneven light emission. Specifically, in the method of manufacturing the organic EL display device 1, when the auxiliary electrode 20 is processed, the transparent electrode 14 in the non-formation region 6 where the auxiliary electrode 20 is not formed is protected by the protective film 3. Compared with the case where the configuration is not adopted, the erosion of the transparent electrode 14 exposed in the non-formation region 6 is suppressed, and uneven light emission can be suppressed.

  In the manufacturing method of the organic EL display device 1, the thickness of the protective film 3 is twice or more the thickness of the auxiliary electrode 20, so that the protective film 3 is etched by overetching when the precursor film 205 is etched. The erosion of the transparent electrode 14 due to can be prevented.

  In the manufacturing method of the organic EL display device 1, since the side surface 30 of the protective film 3 has an inversely tapered shape, erosion of the side surface 200 of the auxiliary electrode 20 is suppressed when the precursor film 205 of the auxiliary electrode 20 is processed. can do.

  As mentioned above, although some embodiment and modification of this invention were demonstrated, these embodiment and modification are only examples, and do not limit the invention based on a claim. These novel embodiments and modifications can be implemented in various other forms, and various omissions, replacements, changes, and the like can be made without departing from the scope of the present invention. In addition, not all combinations of features described in these embodiments and modifications are necessarily essential to the means for solving the problems of the invention. Further, these embodiments and modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Organic EL display device, 3 ... Protective film, 5 ... Formation area | region, 6 ... Non-formation area | region, 10 ... 1st barrier film, 12 ... 2nd barrier film, 14 ... Transparent electrode, 16 ... Organic light emitting layer, DESCRIPTION OF SYMBOLS 18 ... Upper electrode, 20 ... Auxiliary electrode, 22 ... Insulating film, 24 ... Adhesive layer, 30 ... Side surface, 200 ... Side surface, 205 ... Precursor film, 220 ... Side surface

Claims (5)

Prepare a substrate on which a transparent electrode is formed,
Forming a protective film in a non-formation region outside the formation region for forming the auxiliary electrode on the transparent electrode;
Forming a precursor film of the auxiliary electrode on at least the formation region and the protective film;
Processing the precursor film to form the auxiliary electrode in the formation region;
Removing the protective film,
A method for manufacturing an organic EL display device. The protective film has a thickness that is twice or more the thickness of the auxiliary electrode.
The manufacturing method of the organic electroluminescent display apparatus of Claim 1. The protective film is formed so that the side surface on the non-formation region side has an inversely tapered shape,
The manufacturing method of the organic electroluminescent display apparatus of Claim 1 or 2. The protective film is a resist film or a metal film having etching resistance different from that of the auxiliary electrode.
The manufacturing method of the organic electroluminescence display of any one of Claims 1 thru | or 3. A substrate,
A first electrode provided on the substrate;
An organic light emitting layer provided on the first electrode;
A second electrode provided on the organic light emitting layer;
A side electrode on the organic light emitting layer side having a tapered shape, provided on the first electrode, and an auxiliary electrode electrically connected to the first electrode;
An organic EL display device.

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