JP2001307876A - Organic el display device, its manufacturing method and forming method of insulation rib of organic el display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to easily and appropriately form an insulation rib partitioning an organic EL membrane and electrode of organic EL display device, and eliminate the fear to produce an erroneous electric conduction between mutual organic EL membrane and electrode. SOLUTION: This is the organic EL display device wherein plural insulation ribs 1 are installed at the first plural electrodes 3A on a substrate 4, and wherein the organic EL membrane 4 and the second electrode 3B are installed between these plural insulation ribs 1 each other. The respective insulation ribs 1 have a lower layer part 10 and an upper layer part 11 which are different in material and mutually laminated, and the upper layer part 11 is formed with a wider breadth than the lower part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an organic EL (Electric EL).
Patent application title: Organic EL display device for displaying an image using ro luminance, organic EL display device manufacturing method, and organic EL device
The present invention relates to a method for forming insulating ribs formed in a display device.

[0002]

2. Description of the Related Art As is well known, in recent years, an organic EL display device has begun to attract attention as a display used in various applications such as a cellular phone, an audio device, or an instrument panel of an automobile.
Its development is underway. The organic EL display device is a self-luminous system in which the light-emitting layer of the organic EL film emits light. Therefore, unlike a non-self-luminous system, for example, a liquid crystal display device, it does not require a light source such as a backlight or external light. There are features. Further, the organic EL display device has advantages such as a reduction in overall thickness, an increase in viewing angle, a reduction in power consumption when a display image area is small, and a short response time for image display. Have. Therefore, in the future, it is expected that one trend will be to use the organic EL display device for various image display applications in addition to or instead of the liquid crystal display device that is currently frequently used. Similar to the liquid crystal display device, the organic EL display device includes a simple matrix system (passive matrix system) and an active matrix system.
The structure is simpler than the active matrix method,
There is an advantage that the manufacturing cost can be reduced.

FIG. 4 shows an example of a conventional organic EL display device employing a simple matrix system. This conventional organic EL
The display device includes, on a transparent substrate 2, a plurality of transparent anodes 3A extending in a certain direction (the left-right direction in the figure), a plurality of insulating ribs 9 extending on the plurality of anodes 3A in a direction orthogonal thereto, and a plurality of these. A plurality of organic EL films 4 and a plurality of cathodes 3B located between the insulating ribs 9 are provided. A plurality of organic EL films 4 and a plurality of cathodes 3
B extends in a direction orthogonal to the plurality of anodes 3A. Each organic EL film 4 includes, for example, a hole transport layer 40 and a light emitting layer 4.
The light emitting layer 41 emits light when electricity is supplied using the anode 3A and the cathode 3B. The light emitted from the light emitting layer 41 passes through the transparent anode 3A and the transparent substrate 2 and travels downward in FIG.

Each insulating rib 9 is formed in a substantially trapezoidal cross section or a substantially inverted triangular cross section in which the width becomes narrower toward the lower side closer to the transparent substrate 2 because the both side faces 90 are tapered. . Each insulating rib 9 is, as described below,
When forming a plurality of organic EL films 4 and a plurality of cathodes 3B, they serve as partition walls thereof.

In order to manufacture an organic EL display device, a plurality of anodes 3A are first placed on a transparent substrate 2 as shown in FIG.
And a plurality of insulating ribs 9 are formed. Next, FIG.
As shown in FIG. 2, a plurality of organic E
An L film 4 is formed on the plurality of anodes 3A, and thereafter, FIG.
As shown in FIG. 7, a plurality of cathodes 3B are formed. Each of the insulating ribs 9 is provided with a plurality of such organic EL films 4 and a plurality of cathodes 3B.
Plays a role in separating these when forming a film. The reason why the insulating ribs 9 are used in these series of steps is that patterning of the organic EL by the etching process is difficult.

In the above-described steps, the organic EL film 4 and the cathode 3B are prevented from being formed on both side surfaces 90 of each of the insulating ribs 9 because each of the insulating ribs 9 has the above-mentioned predetermined shape. It is possible. For example, as shown in FIG. 6, when both side surfaces 90 of each insulating rib 9 are non-tapered, raw material particles of the organic EL film 4 and the cathode 3B adhere to the both side surfaces 90, and a film is formed. . In this case, each layer of the organic EL film 4 and the cathode 3B are directly connected to each other in this portion, and it may be difficult to make the light emitting layer 41 emit light properly. However, both sides 9 of each insulating rib 9
If 0 is a predetermined tapered surface, such a situation can be prevented.

Conventionally, each insulating rib 9 has a so-called single-layer structure, and is manufactured by, for example, a process shown in FIG. That is, conventionally,
First, as shown in FIG. 3A, a photosensitive resin layer 9 ′ is provided on the anode 3A of the transparent substrate 2. Next, as shown in FIG. 6B, the resin layer 9 ′ is
(C), a developing process (etching process) was performed to convert a part of the resin layer 9 'into an insulating rib 9 having a predetermined cross-sectional shape, as shown in FIG.

[0008]

In the above-mentioned conventional means, in order to make the both side surfaces 90 of each insulating rib 9 a predetermined tapered surface, when the developing process of the resin layer 9 'is carried out, The erosion by the developer must be increased by an appropriate dimension s1 in the lower part than in the upper part. In addition, the amount of erosion needs to be gradually increased from the upper portion to the lower portion of the resin layer 9 '. However, it is not always easy to form both side surfaces 90 of each insulating rib 9 as a tapered surface having a predetermined large inclination angle by such processing. In FIGS. 4, 5 and 7, both side surfaces 90 are shown as planes having a large inclination angle, but actually both side surfaces 90 are formed as curved surfaces bulging outward. In general, the inclination angle cannot be increased in many cases. As a result, in the related art, a defect similar to that described with reference to FIG. In some cases, unreasonable electrical conduction may occur between the cathodes 3B.

Each of the insulating ribs 9 has an upper width L1.
(See FIG. 4) must be precisely defined to a predetermined width. If there is a large error in the width L1, the plurality of organic EL films 4 and the plurality of cathodes 3 separated by the plurality of insulating ribs 9 will be described.
This is because a large variation also occurs in the width of B. However, conventionally, when each insulating rib 9 is formed, the both sides 90 must be formed in a predetermined tapered surface, so that the upper width L1 of each insulating rib 9 is set to a predetermined accurate dimension. It was also difficult to specify.

The present invention has been conceived in view of such circumstances, and enables an insulating rib for partitioning an organic EL film and an electrode of an organic EL display device to be formed easily and appropriately. It is an object of the present invention to eliminate the possibility of unreasonable electrical conduction between organic EL films and electrodes.

[0011]

DISCLOSURE OF THE INVENTION In order to solve the above problems, the present invention employs the following technical means.

The organic EL display device provided by the first aspect of the present invention includes a plurality of first electrodes provided on a substrate and extending in a certain direction, and intersecting with the plurality of first electrodes. Insulating ribs extending in the direction in which the first electrodes extend, and a plurality of organic EL films provided by laminating between the plurality of insulating ribs. And a plurality of second electrodes, wherein each of the insulating ribs has a lower layer portion and an upper layer portion which are laminated with each other and made of different materials, and The upper part is formed wider than the lower part.

According to a method for manufacturing an organic EL display device provided by a second aspect of the present invention, a step of providing a plurality of first electrodes extending in a certain direction on a substrate, and intersecting the plurality of first electrodes is provided. Providing a plurality of insulating ribs on the first electrodes, the plurality of insulating ribs extending in a direction, and arranged at intervals in a direction in which the plurality of first electrodes extend; And forming a film by laminating an organic EL film and a plurality of second electrodes, wherein the insulating ribs are:
It is characterized in that it has a lower layer portion and an upper layer portion that are laminated with each other and are made of different materials, and that the upper layer portion is formed to be wider than the lower layer portion.

In the present invention, since the upper layer of each of the insulating ribs is formed wider than the lower layer, each of the insulating ribs functions to properly partition the organic EL film and each of the second electrodes. Fulfill. That is, in the manufacturing process of the organic EL display device, when each organic EL film and each second electrode are formed between the plurality of insulating ribs using, for example, a vapor deposition unit, both side surfaces of the lower layer of each insulating rib are formed. The raw material particles of the organic EL and the second electrode, which are going to progress toward, are blocked by the wide upper layer of each of the insulating ribs. Therefore, the organic EL film and the second electrode can be prevented from being formed on both side surfaces of the lower layer portion of each of the insulating ribs, thereby preventing unreasonable electrical conduction between these.

On the other hand, since each of the insulating ribs has a structure of at least two layers having a lower layer and an upper layer made of different materials, each of the lower layer and the upper layer is
It can be formed individually by separate etching processing steps. Therefore, unlike the related art, both the lower layer portion and the upper layer portion can be accurately finished to a predetermined width. As a result, the width of each organic EL film and each second electrode formed between the plurality of insulating ribs can be accurately defined to a desired width. In addition, it is possible to easily increase the difference in lateral width between the lower layer portion and the upper layer portion, and at the time of forming the organic EL film or the second electrode, the raw material particles are deposited on both side surfaces of the lower layer portion. It is possible to more reliably prevent the film from being undesirably attached.

The method for forming an insulating rib of an organic EL display device provided by the third aspect of the present invention comprises the steps of:
A step of providing a first layer and a second layer having a different material from the first layer, the second layer being laminated on the first layer; Forming a band-shaped upper layer portion having a width, and forming a band-shaped lower layer portion narrower than the upper layer portion directly below the upper layer portion by etching the first layer. It is characterized by having.

According to the method for forming the insulating ribs of the organic EL display device having such a configuration, each of the insulating ribs of the organic EL display device provided by the first aspect of the present invention is appropriately and simply formed. can do.

In a preferred embodiment of the present invention, each of the first and second layers is made of a photosensitive resin having the same negative / positive type.

According to such a configuration, the etching process of the first and second layers can be easily performed by the same process as the exposure and development process for a general photoresist. In addition, if the type of the negative / positive of the first and second layers is the same, the exposure processing on the first and second layers can be performed collectively,
The number of working steps can be reduced.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. In the drawings showing the embodiments of the present invention, the same or similar elements as those in the conventional example are denoted by the same reference numerals as those in the conventional example.

FIG. 1 is a perspective view of an essential part showing an example of an organic EL display device according to the present invention. Organic EL of this embodiment
The display device A is different from the prior art in the form of the plurality of insulating ribs 1, and the other configuration is the same as the conventional technology. More specifically, this organic E
The L display device A has a structure in which a plurality of anodes 3A, a plurality of organic EL films 4, and a plurality of cathodes 3B are sequentially stacked on a transparent substrate 2 from below to above. The organic EL film 4 and the plurality of cathodes 3B are partitioned via the plurality of insulating ribs 1 formed on the plurality of anodes 3A. Each anode 3A corresponds to an example of a first electrode according to the present invention. Each cathode 3B is the second
This corresponds to an example of an electrode.

The transparent substrate 2 is made of, for example, a glass plate or a synthetic resin plate. Each anode 3A is a transparent electrode made of, for example, an ITO film, and has a band shape extending in a certain direction. The plurality of anodes 3A are arranged substantially in parallel at regular intervals in a direction orthogonal to their longitudinal direction. Each organic EL film 4 has a band shape extending in a direction intersecting with each anode 3A, and includes, for example, three layers of a hole transport layer 40, a light emitting layer 41, and an electron transport layer 42. The specific components of each of the layers of the organic EL film 4 have been known in the art, and a description thereof will be omitted. It is to be noted that development of an organic EL film having a structure other than the above structure is being promoted. Therefore, in the present invention, the specific structure of the organic EL film is not limited to the above three layers.

Each cathode 3B is made of, for example, aluminum or an aluminum alloy, has a band shape extending in the same direction as each organic EL film 4, and is laminated on the electron transport layer 42 of each organic EL film 4. Although omitted in the drawing, a plurality of wires are connected to one end of each of the anodes 3A and the cathodes 3B in the longitudinal direction, and a positive electrode is connected to the plurality of electrodes via the plurality of wires. Voltage application or ground connection can be selectively performed. The portions where the plurality of anodes 3A and the plurality of cathodes 3B cross each other and face each other are arranged in a matrix, and the plurality of organic EL films 4 are sandwiched between them. Therefore, when a plurality of anodes 3A and a plurality of cathodes 3B are selected and the organic EL film 4 at a predetermined location is energized, the light emitting layer 41 at that portion emits light, and this light is emitted from the anode 3A and the transparent substrate 2A. As a result, the desired image can be displayed.

Each of the insulating ribs 1 extends in a direction orthogonal to the plurality of anodes 3, and is arranged substantially parallel to the direction in which the plurality of anodes 3 extend at regular intervals. However, each insulating rib 1
Has a two-layer structure having a lower layer portion 10 and an upper layer portion 11 laminated on the lower layer portion 10. The lower layer portion 10 and the upper layer portion 11 are made of photosensitive resins having different materials. However, the lower part 10 and the upper part 11
Are positive or negative, and the types of positive and negative are the same. The lower layer portion 10 has a rectangular cross section in which both side surfaces 10a are non-tapered. The upper layer 11 has a width Sb that is equal to that of the lower layer 1.
0 is a rectangular shape having a cross section that is longer than the width Sa, and both side edges 11a in the width direction of the upper layer portion 11 are formed to protrude more than the lower layer portion 10 in the width direction of the insulating rib 1. ing.

Next, an example of a method of manufacturing the organic EL display device A having the above configuration, an example of a method of forming the insulating ribs 1, and an operation thereof will be described.

First, as shown in FIG. 2A, after a plurality of anodes 3A are formed on the transparent substrate 2, first and second anodes made of two kinds of photosensitive resins are formed on the plurality of anodes 3A. The two layers 10 ′ and 11 ′ are formed in an overlapping manner. Note that, unlike the organic EL film 4, the plurality of anodes 3A can be patterned by etching. After that, as shown in FIG.
The exposure processing for each of the first layer 10 'and the second layer 11' is performed collectively. First and second layers 1
If the positive / negative types of 0 'and 11' are the same type, it is possible to perform collective exposure processing on these mutually overlapping specific portions of the first and second layers 10 'and 11'. It is.

After the exposure process, a development process (etching process) is performed on the second layer 11 'as shown in FIG. When the second layer 11 'is negative,
The exposed portion is left by the developing process, and thereby, a portion corresponding to each upper layer portion 11 of the plurality of insulating ribs 1 can be formed. Next, as shown in FIG. 3D, a developing process is performed on the first layer 10 ′. The developing solution used for developing the first layer 10 '
That does not erode the layer 11 ′ of the substrate. By doing so, it is possible to appropriately etch only the first layer 10 'while preventing the remaining portion of the second layer 11' already formed as the upper layer portion 11 of the insulating rib 1 from being unduly etched. Thus, the lower layer portion 10 of the insulating rib 1 can be formed. In developing the first layer 10 ', over-etching (excess etching) is performed to etch the exposed portion excessively. Thereby, the width of the lower layer 10 can be made smaller than the width of the upper layer 11, and the insulating ribs 1 with the overhang dimension Sc of the side edges 11 a of the upper layer 11 with respect to the lower layer 10 can be appropriately and appropriately. It can be easily formed.

After the insulating ribs 1 are formed as described above, the organic EL film 4 and the cathode 3B having the structure shown in FIG.
Is formed between the plurality of insulating ribs 1. As shown in FIG. 3, for example, in a film forming process of the organic EL film 4,
The raw material particles of the organic EL film 4 are composed of a plurality of anodes 3A and a transparent substrate 2
In the process, the upper layer 11 of the insulating rib 1 blocks particles that are going to move toward both side surfaces 10 a of the lower layer 10. More specifically, the side edges 11a of the upper layer portion 11 play a role of forming a region where the organic EL particles do not reach a portion closer to the transparent substrate 2 than that. As a result, it is possible to prevent the above-mentioned particles from adhering to both side surfaces 10a of the lower layer portion 10 and forming a film.

Thus, the three layers of the hole transport layer 40, the light emitting layer 41, and the electron transport layer 42 of the organic EL film 4 can be appropriately formed between the insulating ribs 1 adjacent to each other. The lower part 10
Can be prevented from being connected to each other on both side surfaces 10a. Similarly, the cathode 3B is placed on the organic EL film 4.
Is formed on the both side surfaces 10a of the lower layer part 10 even when the cathode 3B is formed by using the vapor deposition means, and the cathode 3B is not formed on the light emitting layer 41 of the organic EL film 4 or the hole. It is also possible to prevent direct conduction with the transport layer 40. Therefore, it is possible to prevent light emission failure of the light emitting layer 41, and to improve the yield in manufacturing the organic EL display device A. Note that a film similar to the organic EL film 4 and the cathode 3B is formed on the upper layer portion 11 of each insulating rib 1.
Also formed on top. However, in FIG. 1, those films are omitted.

As understood from the method of forming the insulating ribs 1 shown in FIG. 2, when the lower layer 10 is formed by developing the first layer 10 ', the width of the upper layer 11 may be reduced. Since there is no, the final lateral width of the upper layer portion 11 can be accurately defined to a desired dimension. Therefore, the width of each organic EL film 4 and each cathode 3B is also
The desired width can be precisely defined, and the quality of the organic EL display device A can be improved.

The specific contents of the present invention are not limited to the above embodiment.

There are two types of organic EL display devices, one for monochrome display and the other for color display.
The display device may be configured as either a monochrome display or a color display. When color display is performed using a color filter or a color conversion layer, a color filter layer or a color conversion layer is provided between the anode and the transparent substrate. Therefore, in the present invention, the first
The electrodes need not necessarily be provided directly on the surface of the substrate (transparent substrate). In the above embodiment, the first
Although the electrode is used as an anode and the second electrode is used as a cathode, in the present invention, on the contrary, the first electrode may be used as a cathode and the second electrode may be used as an anode. In addition, in the present invention, the specific material and size of the lower layer and the upper layer of the insulating rib can be variously changed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part showing an example of an organic EL display device according to the present invention.

FIGS. 2A to 2D are cross-sectional views illustrating an example of a method for forming an insulating rib.

FIG. 3 is an operation explanatory diagram when an organic EL film is formed.

FIG. 4 is a sectional view of a main part showing an example of a conventional organic EL display device.

FIGS. 5A to 5C are cross-sectional views showing a conventional process for manufacturing an organic EL display device.

FIG. 6 is an explanatory diagram of the operation when both side surfaces of the insulating rib are non-tapered surfaces.

FIGS. 7A to 7C are cross-sectional views illustrating a conventional method for forming an insulating rib.

[Explanation of symbols]

 Reference Signs List A Organic EL display device 1 Insulating rib 2 Transparent substrate (substrate) 3A Anode (first electrode) 3B Cathode (second electrode) 4 Organic EL film 10 Lower layer portion 10 'First layer 10a Side surface (lower portion) 11 Upper layer Part 11 'second layer 41 light emitting layer

Claims (4)

[Claims] A plurality of first electrodes provided on a substrate and extending in a predetermined direction; and a plurality of first electrodes extending on the plurality of first electrodes in a direction intersecting with the first electrodes. A plurality of insulating ribs arranged in a row at intervals in the direction, a plurality of organic EL films and a plurality of second electrodes provided by laminating between the plurality of insulating ribs. An EL display device, wherein each of the insulating ribs has a lower layer portion and an upper layer portion that are laminated with each other and made of different materials, and the upper layer portion is formed wider than the lower layer portion. An organic EL display device comprising: Providing a plurality of first electrodes extending in a predetermined direction on the substrate; extending in a direction intersecting with the plurality of first electrodes and spaced apart in a direction in which the plurality of first electrodes extend. Providing a plurality of insulating ribs arranged in a row on the plurality of first electrodes; and forming a stack of a plurality of organic EL films and a plurality of second electrodes between the plurality of insulating ribs. A method for manufacturing an organic EL display device, comprising: a lower layer portion and an upper layer portion each of which is laminated and different in material, and wherein the upper layer portion is formed of the lower layer portion. A method for manufacturing an organic EL display device, wherein the organic EL display device is formed to have a width wider than that of the organic EL display device. 3. A method according to claim 1, wherein the first layer is made of a material different from that of the first layer, and the second layer laminated on the first layer is formed on the substrate.
A step of forming a band-shaped upper layer having a certain width by etching the second layer; and a step of narrowing the upper layer by etching the first layer. Forming a strip-shaped lower layer portion directly below the upper layer portion. A method for forming an insulating rib of an organic EL display device, comprising: 4. The method according to claim 3, wherein each of the first and second layers is made of a photosensitive resin having the same negative / positive type.