WO2011070681A1

WO2011070681A1 - Organic el panel and method for manufacturing same

Info

Publication number: WO2011070681A1
Application number: PCT/JP2009/070774
Authority: WO
Inventors: 尾越　国三; 一弘竹田; 渡辺　輝一; 正宣赤木; 竜一佐藤
Original assignee: パイオニア株式会社; 東北パイオニア株式会社
Priority date: 2009-12-11
Filing date: 2009-12-11
Publication date: 2011-06-16
Also published as: CN102612858A; JPWO2011070681A1

Abstract

The surface of a coat material layer formed on an electrode is planarized, and at the same time, correct patterning is performed so as to uniformly form a film thereon. In an organic EL panel (100), a first electrode (11) is formed on a substrate (10), a pattern (20A) of an insulating wall (20) is formed on the substrate (10) so as to surround the surface to be coated on the first electrode (11), a coat material layer (14) is formed by applying a coat material onto the surface to be coated within the pattern (20A) of the insulating wall (20), an organic layer (13) including a light emitting layer is laminated on the coat material layer (14), and a second electrode (12) is formed on the organic layer (13). The insulating wall (20) has, on the inner surface of the pattern (20A), an overhung section (20B) which suppresses expansion of the coat material layer (14), an insulating wall (20) portion above the coat material layer (14) is deformed by heating and melting the insulating wall (20) after forming the coat material layer (14), and a tilted surface (22) or a curved surface (22A) which ensures continuity of the second electrode (12) is formed.

Description

Organic EL panel and manufacturing method thereof

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

An organic EL element has a structure in which an organic layer including a light emitting layer is laminated between a pair of electrodes, and an organic EL panel in which one or a plurality of organic EL elements are arranged on a substrate is structurally or It has an insulating structure that partitions electrically. Examples of the insulating structure include an insulating film that partitions an electrode formed on a substrate for each pixel, a partition for separating an electrode formed on an organic layer, and the like.

In such an organic EL element, the surface state of the electrode, which is the film formation surface of the organic layer, has a great influence on the quality of the light emission characteristics. If the surface of the electrode is uneven, the film thickness of the organic layer deposited thereon is not uniform, and light emission defects such as leakage are likely to occur in the organic EL element. In order to solve this problem, a technique has been developed in which a wet organic layer (conductive polymer or the like) is applied on an electrode, and a light emitting layer or the like is formed on the planarized organic layer.

For example, the following Patent Document 1 describes an organic EL panel having an insulating wall as shown in FIG. In this prior art, a first electrode J2 corresponding to a plurality of pixels is provided on an insulating surface of a substrate J1, an insulating wall J3 is provided so as to surround the first electrode J2, and the insulating wall J3 and the first electrode J2 are provided on the insulating surface J3. A conductive polymer layer J4 is formed, an organic layer J5 including a light emitting layer is formed on the conductive polymer layer J4, and a second electrode J6 is formed on the organic layer J5.

JP 2004-145244 A

According to such a conventional technique, since the coating material layer such as the conductive polymer layer fills the unevenness of the electrode surface and flattens its surface, it becomes possible to make the film laminated thereon uniform and resistant. It is possible to improve the light emission performance and durability performance, such as improving leakage. In addition, by adding an acceptor (dopant) to the wet film-forming film formed on the electrode, the charge injection efficiency is improved, and a low voltage can be realized.

However, when the coating material layer is formed in the region surrounded by the insulating wall as shown in FIG. 1, the surface of the coating material layer formed on the electrode by the surface tension of the coating material adhering to the side surface of the insulating wall J3. Is not flat, and the film thickness (evaporated film, etc.) formed thereon differs between the central part and the peripheral part, and uniform light emission cannot be obtained over the entire pixel region surrounded by the insulating wall. Occurs.

Further, when the inner side inclination angle θ of the side surface of the insulating wall J3 is small as shown in FIG. Therefore, there arises a problem that the coating material layer cannot be properly patterned.

The present invention is an example of a problem to deal with such a problem. That is, the surface of the coating material layer formed on the electrode is flattened, and at the same time, appropriate patterning is performed, and the light emitting characteristics of the organic EL element are improved by making the film formed thereon uniform. These are the objects of the present invention.

In order to achieve such an object, the organic EL panel and the manufacturing method thereof according to the present invention have at least the following configuration.

A substrate, a first electrode formed directly on the substrate or via another layer, a coating material layer coated on the first electrode, an insulating wall for patterning the coating material layer, An organic layer including a light-emitting layer laminated on the coating material layer and a second electrode formed on the organic layer, and the insulating wall has a side surface in contact with the coating material layer spreading the coating material layer An organic EL panel having an overhang portion that suppresses sag and an inclined surface or a curved surface that ensures continuity of the second electrode above the coating material layer.

Forming a first electrode on the substrate directly or via another layer, forming a pattern of an insulating wall on the substrate so as to surround a surface to be coated on the first electrode, and the insulating wall A step of applying a coating material on the surface to be coated in the pattern of forming a coating material layer, a step of laminating an organic layer including a light emitting layer on the coating material layer, and a second step on the organic layer. Forming an electrode, and the insulating wall has an overhang portion that suppresses the spreading of the coating material layer on the inner surface of the pattern, and the insulating wall is heated and melted after the coating material layer is formed. Thus, an organic EL panel manufacturing method is characterized in that a portion of the insulating wall above the coating material layer is deformed to form an inclined surface or a curved surface that ensures the continuity of the second electrode.

It is explanatory drawing of a prior art. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram for explaining the configuration of an organic EL panel according to an embodiment of the present invention (FIG. 1A is a sectional view taken along line XX in FIG. 1B, and FIG. 1B is a plan view). It is explanatory drawing explaining the manufacturing method of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing which showed the example of various forms of the insulating wall. It is explanatory drawing which showed the example of various forms of the insulating wall. It is explanatory drawing which showed the example of formation of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing which showed the example of formation of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing which showed the example of formation of the organic electroluminescent panel which concerns on embodiment of this invention. It is explanatory drawing which showed the example of formation of the organic electroluminescent panel which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment of the present invention includes the contents shown in the drawings, but is not limited thereto. FIG. 2 is an explanatory diagram for explaining the configuration of an organic EL panel according to an embodiment of the present invention (FIG. 2A is a sectional view taken along line XX in FIG. 2B, and FIG. 2B is a plan view). is there. An organic EL panel 100 according to an embodiment of the present invention is obtained by forming an organic EL element 1 in which an organic layer 13 including a light emitting layer is laminated between a first electrode 11 and a second electrode 12 on a substrate 10. The substrate 10, the first electrode 11 formed on the substrate 10 directly or via another layer, the coating material layer 14 applied and formed on the first electrode 11, and the coating material layer 14 are patterned. An insulating wall 20, an organic layer 13 including a light emitting layer stacked on the coating material layer 14, and a second electrode 12 formed on the organic layer 13. In the illustrated example, the insulating wall 20 is formed along the side portion of the first electrode 11, and an opening pattern 20 </ b> A is formed on the first electrode 11. The pattern of the insulating wall 20 is not limited to the opening pattern 20A and can be formed in various forms, and the coating material layer 14 can be patterned into a free shape according to the form of this pattern.

The insulating wall 20 has an overhang portion 20B in which the side surface 21 in contact with the coating material layer 14 suppresses the spread of the coating material layer 14, and the inclined surface 22 that ensures the continuity of the second electrode 12 above the coating material layer 14. Or it has a curved surface. That is, the insulating wall 20 has a shape in which a side surface 21 in contact with the coating material layer 14 and a portion above the coating material layer 14 are different, and in the illustrated example, the side surface 21 is inclined to be inclined toward the coating material layer 14 side. The inclined surface 22 is inclined to the opposite side to the side surface 21.

In the organic EL panel 100 having such a structure, the surface of the coating material layer 14 formed on the first electrode 11 is flattened, and at the same time, appropriate patterning is performed, and the organic layer 13 formed thereon is uniformly formed. As a result, the emission characteristics of the organic EL element 1 can be made uniform over the entire opening pattern 20A.

FIG. 3 is an explanatory diagram for explaining a method of manufacturing an organic EL panel according to an embodiment of the present invention. In the method of manufacturing the organic EL panel 100, the first electrode 11 is formed on the substrate 10 directly or through another layer (see FIG. 1A), and the first electrode 11 on the substrate 10 is covered. Step 2 of forming the pattern of the insulating wall 20 so as to surround the coating surface (see FIG. 2B), coating the coating material on the coated surface on the first electrode 11 in the pattern of the insulating wall 20 Step 3 for forming the layer 14 (see (c) in the same figure), Step 4 for heating and melting the insulating wall 20 (curing treatment) (see (d) in the same figure), an organic layer including a light emitting layer on the coating material layer 14 Step 5 (see FIG. 5E) for laminating layer 13 and Step 6 for forming second electrode 12 on organic layer 13 (see FIG. 5F) are included. In the example shown in the drawing, an insulating wall 20 is formed along the side of the first electrode 11 on the substrate 10 to form an opening pattern 20A on the first electrode 11, and the inside of the opening pattern 20A is covered with a coating material. The coated surface.

In step 1 described above, a conductive film is formed by, for example, vapor deposition or sputtering on the substrate 10 using glass, plastic, metal having an insulating film formed on the surface, etc., and the first is performed by a pattern forming step such as a photolithography step. A pattern of the electrode 11 is formed.

In step 2 described above, not only the opening pattern 20A of the insulating wall 20 is formed, but also an overhang portion is formed in the insulating wall 20. The insulating wall 20 is pre-baked by spin-coating, for example, a lift-off negative photoresist whose UV light transmission is intentionally lowered. And it exposes by irradiating UV light through the hard chrome mask provided with the light transmission slit. At this time, since the above-described photoresist has a low transmittance of UV light, a difference in solubility in a developing solution occurs in the depth direction. Therefore, the insulating wall 20 having the overhang portion 20B as shown in FIG. 4B is formed by the difference in developability by spray showering the alkaline developer on the substrate 10. In the illustrated example, the vertical cross-sectional shape of the insulating wall 20 is a substantially inverted isosceles trapezoidal shape.

In step 3 described above, the coating material is applied using the coating apparatus 14A. Application | coating here includes spray application | coating, dispenser application | coating, inkjet, printing, etc. As a coating material, a polymer material or a polymer material containing a low-molecular material is suitable. A polyalkylthiophene derivative, a polyaniline derivative, triphenylamine, an inorganic compound sol-gel film, an organic compound film containing a Lewis acid A conductive polymer can be used. In Step 3, since the overhang portion 20B is formed on the insulating wall 20, the spread of the coating material layer 14 is suppressed, and the coating material layer 14 forms a layer on the first electrode 11 substantially flat.

In step 4 described above, after the coating material layer 14 is formed, the substrate 10 on which the first electrode 11, the insulating wall 20, and the coating material layer 14 are formed is placed in the heating tank M and subjected to heat melting treatment. As a result, the upper portion of the insulating wall 20 (the portion above the coating material layer 14) is deformed to form the inclined surface 22 shown in FIG. 2 or the curved surface 22A as shown in FIG. As a result, the insulating wall 20 has an overhang portion 20B in which the side surface 21 in contact with the coating material layer 14 suppresses the spread of the coating material layer 14, and ensures the continuity of the second electrode 12 above the coating material layer 14. It has the inclined surface 22 or the curved surface 22B.

In step 5 described above, the organic layer 13 including the light emitting layer is formed by vacuum deposition or the like. An example of forming the organic layer 13 formed on the coating material layer 14 will be described. For example, first, NPB (N, N-di (naphtalence) -N, N-dipheneyl-benzidene) is formed as a hole transport layer. The hole transport layer has a function of transporting holes injected from the lower electrode line 2 to the light emitting layer. The hole transport layer may be a single layer or a stack of two or more layers. In addition, the hole transport layer is not formed by a single material, but a single layer may be formed by a plurality of materials, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. Doping may be performed.

Next, a light emitting layer is formed on the hole transport layer. As an example, red (R), green (G), and blue (B) light-emitting layers are formed in respective film formation regions by using a resistance heating vapor deposition method using a coating mask. As the red (R), an organic material that emits red light such as a styryl dye such as DCM1 (4- (dicyanomethylene) -2-methyl-6- (4′-dimethylaminostyryl) -4H-pyran) is used. An organic material that emits green light such as an aluminum quinolinol complex (Alq ₃ ) is used as green (G). As the blue (B), an organic material emitting blue light such as a distyryl derivative or a triazole derivative is used. Of course, other materials or a host-guest layer structure may be used, and the light emission form may be a fluorescent light emitting material or a phosphorescent light emitting material.

The electron transport layer formed on the light emitting layer is formed by using various materials such as an aluminum quinolinol complex (Alq ₃ ) by various film forming methods such as resistance heating vapor deposition. The electron transport layer has a function of transporting electrons injected from the upper electrode line 3 to the light emitting layer. This electron transport layer may have a multilayer structure in which only one layer is stacked or two or more layers are stacked. In addition, the electron transport layer may be formed of a plurality of materials instead of a single material, and a guest material having a high charge donating (accepting) property may be formed on a host material having a high charge transport capability. It may be formed by doping.

In step 6 described above, the second electrode 12 is formed by vacuum deposition or the like. One of the first electrode 11 and the second electrode 12 functions as an anode and the other functions as a cathode. The first electrode 11 employs a transparent conductive film such as ITO in the case of a top emission method in which light is extracted from the substrate side. The cathode uses a material having a work function lower than that of the anode. When ITO is used as the anode, a magnesium alloy such as aluminum (Al) or Mg—Al can be used as the cathode.

4 and 5 are explanatory views showing various forms of the insulating wall 20. The overhang portion 20B formed on the insulating wall 20 refers to a shape covering the end portion of the coating material layer 14, and is not limited to the shape of the side surface 21 shown in FIG. It may include a form.

In the example shown in FIG. 4A, a protruding portion 21a that protrudes toward the coating material layer 14 is formed on the side surface 21 of the insulating wall 20, and the cross-sectional shape of the insulating wall 20 before heat forming is substantially T-shaped. ing. It changes from the state before heating and melting in (a1) to the state after heating (a2). In the state (a2), the insulating wall 20 covers the side surface and part of the upper surface of the coating material layer 14 to form an overhang portion 20B. A curved surface 22 </ b> A is formed on the coating material layer 14.

In the example shown in FIG. 4B, a protruding portion 21a1 protruding toward the coating material layer 14 is formed on the side surface 21 of the insulating wall 20, and the protruding portion 21a1 has a corner. It changes from the state before heating and melting in (b1) to the state after heating (b2). In the state (b2), the insulating wall 20 covers the side surface and part of the upper surface of the coating material layer 14 to form an overhang portion 20B. A curved surface 22 </ b> A is formed on the coating material layer 14.

The cross-sectional shape of the insulating wall 20 does not have to be symmetrical, and the overhang portion 20B may be formed only on one side. In FIG. 4C, the side surface 21 has an inclined surface 21a2 on only one side. It changes from the state before heating and melting in (c1) to the state after heating (c2). In the state (c2), the insulating wall 20 covers the side surface and part of the upper surface of the coating material layer 14 to form an overhang portion 20B. A curved surface 22 </ b> A is formed on the coating material layer 14.

FIG. 5 shows various cross-sectional shapes of the insulating wall 20 before heating and melting. In the example of FIG. 5A, a plurality of protrusions 21 b 1 and 21 b 2 are formed from the side surface 21. In the example shown in FIG. 5B, the protruding widths of the protruding portion 21c1 on one side and the protruding portion 21c2 on the opposite side are different. In the example shown in FIG. 2C, inclined surfaces 21

d

1 and 21 d 2 with different angles are formed on one side surface 21, and inclined surfaces 21 d 3 and 21 d 4 with different angles are also formed on the other side surface 21. In the example shown in FIG. 4D, the protruding portion 21e is formed only on one side surface 21. In the example shown in FIG. 5E, the protruding portion 21d is formed only on one side surface 21, and the protruding portion 21d has a corner.

6 to 9 are explanatory views showing examples of forming the organic EL panel according to the embodiment of the present invention. Portions common to the above description are denoted by the same reference numerals, and a part of overlapping description is omitted.

FIG. 6 (FIG. 6 (a) shows a plan view of the single panel excluding the second electrode, and FIG. 6 (b) shows a plan view of a plurality of panels formed on a large substrate before division. .) Is an example in which the pattern of the insulating wall 20 is formed along the outer edge of the light emitting region 10E on the substrate 10 in the organic EL panel 100. The coating material layer 14 is patterned by the insulating wall 20. A wiring region 10F is formed outside the light emitting region 10E on the substrate 10, and a wiring 30 connected to the first electrode 11 or the second electrode 12 is formed in the wiring region 10F. In the organic EL panel 100, a plurality of panels are simultaneously formed on a large substrate as shown in FIG. 6B, and a plurality of panels are formed in a series of steps by dividing along the dividing lines C1 to C4. be able to.

The example shown in FIG. 7 (FIG. 7 (a) is a plan view excluding the second electrode, FIG. 7 (b) is an XX sectional view of FIG. 7 (a) including the second electrode) is an organic EL panel. In this example, the insulating wall 20 is formed along the outer edge of the pixel 1G on the substrate 10 in 100. A pixel 1G is formed by the organic EL element 1 described above, and an insulating wall 20 is formed along the outer edge of the pixel 1G. The second electrode 12 is formed across the plurality of pixels 1G, and the end portion is connected to the wiring 30 by the contact portion 12S.

The example shown in FIG. 8 (FIG. 8A is a plan view excluding the second electrode, and FIG. 8B is an XX sectional view of FIG. 8A including the second electrode) is an organic EL panel. In this example, an insulating wall 20 is formed along the outer edge of the pixel 1G on the substrate 10 in 100, and an electrode separation partition wall 30 having a function of separating the second electrode 12 is formed on the insulating wall 20.

FIG. 9 shows another example of the insulating wall 20. The opening pattern 20A of the insulating wall 20 can take various forms. Since the insulating wall 20 can be patterned in various shapes, it can be in the form of numeric segments, icons, or the like shown in FIG.

In such an organic EL panel according to the embodiment of the present invention, the coating material layer 14 is formed on the first electrode 11 so that the coating material layer 14 fills the unevenness of the electrode surface and flattens its surface. Therefore, the organic layer 13 laminated thereon can be made uniform, and the light emission performance and durability performance can be improved, such as improving the leak resistance. Further, by adding an acceptor (dopant) to the coating material applied on the electrode, the charge injection efficiency is improved, and a low voltage can be realized.

Further, since the overhang portion 20B is formed on the inner side surface of the insulating wall 20 surrounding the periphery of the coating material layer 14, the surface of the coating material layer 14 formed on the first electrode 11 is planarized and at the same time appropriate patterning. Further, the organic layer 13 formed thereon can be made more uniform to improve the light emission characteristics of the organic EL element. In particular, uniform light emission characteristics can be obtained over the entire area of the opening pattern 20A, and the quality of the organic EL panel 100 can be improved.

Furthermore, since the insulating wall 20 has an inclined surface 22 or a curved surface 22A that ensures the continuity of the second electrode 12, the organic layer 13 is laminated on the coating material layer 14. When the second electrode 12 is formed thereon, the second electrode 12 without disconnection can be formed, and the highly reliable organic EL panel 100 can be obtained.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

Claims

A substrate,
A first electrode formed directly or via another layer on the substrate;
A coating material layer coated on the first electrode;
An insulating wall for patterning the coating material layer;
An organic layer including a light emitting layer laminated on the coating material layer;
A second electrode formed on the organic layer,
The insulating wall has an overhang portion whose side surface in contact with the coating material layer suppresses the spreading of the coating material layer, and an inclined surface or curved surface that ensures the continuity of the second electrode above the coating material layer. An organic EL panel comprising:
2. The organic EL panel according to claim 1, wherein the overhang portion is an inclined surface inclined toward the coating material layer.
The organic EL panel according to claim 1 or 2, wherein the insulating wall covers a part of a side surface and an upper surface of the coating material layer.
The organic EL panel according to any one of claims 1 to 3, wherein the insulating wall is formed along an outer edge of a light emitting region of the panel.
The organic EL panel according to any one of claims 1 to 3, wherein the insulating wall is formed along an outer edge of a pixel of the panel.
6. The organic EL panel according to claim 5, wherein an electrode separation partition having a function of separating the second electrode is formed on the insulating wall.
Forming a first electrode on the substrate directly or via another layer;
Forming an insulating wall pattern on the substrate so as to surround a surface to be coated on the first electrode;
Applying a coating material on the coated surface in the pattern of the insulating wall to form a coating material layer;
Laminating an organic layer including a light emitting layer on the coating material layer;
Forming a second electrode on the organic layer,
The insulating wall has an overhang portion that suppresses spreading of the coating material layer on the inner surface of the pattern, and the coating material on the insulating wall is heated and melted after the coating material layer is formed. A method of manufacturing an organic EL panel, comprising deforming a portion above the layer to form an inclined surface or a curved surface that ensures the continuity of the second electrode.
The method for manufacturing an organic EL panel according to claim 7, wherein the cross-sectional shape of the insulating wall before deformation is a substantially inverted trapezoidal shape or a substantially T-shape.