JPH1167455A - Organic electroluminescent display device and method for producing thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent display device in which short circuit phenomenon between electrodes formed as cathode electrodes is reliably prevented and which has improved mechanical strength of partitioning walls separating element regions and to provide a method for producing the display device. SOLUTION: This device is provided with a first electrode unidirectionally formed on a substrate 10, partitioning walls 12 formed as to intersect the first electrode 11, organic layers 13, and second electrodes 14. In this case, both side faces of each partitioning wall 12 are substantially stood uprightly in relation to the substrate and together with a part of the upper face, both side faces of each partitioning wall 12 are coated with the organic layers 13 and the second electrodes 14. On the upper face of each partitioning wall 12, neighboring second electrodes 14 are electrically separated. To realize such electric separation, a narrow partitioning wall with narrower width than each partitioning wall 12 is formed before formation of the organic layers 13 and the second electrodes 14 and after that, the organic layers 13 and the second electrodes 14 are formed and successively together with the organic layers 13 and the second electrodes 14 formed on the narrow partitioning wall, the narrow partitioning wall is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an organic electroluminescence display device utilizing electroluminescence of an organic compound material and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, an organic electroluminescent display device of this type is provided on a transparent substrate surface which transmits light.
A plurality of stripe-shaped transparent electrodes formed of ITO or the like extending in one direction, an organic layer formed on the transparent electrodes, and a stripe extending in a direction intersecting the extending direction of the transparent electrodes And a top electrode having the shape of a circle. In this structure, the portions where the transparent electrode and the upper electrode intersect are arranged in a matrix, and pixels are formed. In order to display a fine image, the transparent electrode and the upper electrode are finely processed and formed. There is a need to.

Here, between the upper electrodes adjacent to each other,
Usually, an insulator called a partition is arranged, and the upper electrode is electrically insulated from each other by the partition.

Japanese Patent Application Laid-Open No. Hei 8-315981 discloses that a transparent electrode having a stripe shape is formed on a transparent substrate surface.
Is formed, an electrically insulating partition is provided so as to partially cover the first electrode, and then an organic layer and an upper electrode (hereinafter, referred to as a second electrode) layer And an organic electroluminescent display device having the same, and a method for manufacturing the same. In this case, the second electrode is formed so as to cover not only between adjacent partitions, but also around each partition. As described above, in a configuration in which the periphery of the partition is covered with the second electrode layer, it is necessary to electrically insulate the partition from the adjacent second electrode.

[0005] Therefore, the above-mentioned publication discloses a method of forming an overhang portion above each partition and forming an organic layer and a second electrode layer in this state. In this method, the organic layer and the second electrode layer are not formed in the region of the first electrode covered by the overhang portion of the partition and the side surface of the partition. This means that the organic layer and the second electrode layer are electrically and mechanically separated by the partition having the overhang portion. Therefore, in this configuration, the adjacent second electrodes can be electrically separated from each other.

In the above publication, a negative photoresist such as a chemically amplified resist is spin-coated, and the coated negative photoresist is selectively etched using a photolithography technique, or
Spin-coated positive photoresist is converted to C ₆ H ₅ Cl
After immersion in the solution, a partition having an overhang portion whose upper width is larger than its lower width is formed by using photolithography techniques such as exposure and development.

As described above, a method of providing a partition having an overhang portion is disclosed in JP-A-5-2751 in which an organic luminescent material and a second electrode material are deposited obliquely to the partition.
It has an advantage that the second electrode and the organic layer can be formed more stably than the method disclosed in JP-A-72-72, etc.

[0008]

However, the method described in Japanese Patent Application Laid-Open No. H8-315981 in which an overhang portion is provided on a partition wall is mechanically necessary because the width of the upper portion of each partition is larger than the width of the lower portion. There is a disadvantage that the partition walls easily fall down due to the impact, that is, a disadvantage that the partition wall is weak against mechanical impact.

Further, according to the above-described method, when forming the partition, the width corresponding to the overhang portion is expected,
It is necessary to form a resist or the like, and there is a limit to miniaturization of the partition.

An object of the present invention is to provide an organic electroluminescence display device having high mechanical strength and a fine pattern.

Another object of the present invention is to provide a method for manufacturing an organic electroluminescent display device having high mechanical strength and a fine pattern.

Still another object of the present invention is to provide a method of manufacturing an organic electroluminescent display device which can reliably electrically separate the second electrode material without forming an overhang portion.

[0013]

According to one embodiment of the present invention, a plurality of first electrodes extending in a predetermined direction on a substrate surface, and a plurality of first electrodes extending in a direction intersecting the electrodes are provided. On the substrate surface, a plurality of partitions arranged at intervals from each other, an organic layer disposed between the partitions, and a second electrode formed on each organic layer, the partition, In a cross-section, a pair of side surfaces standing upright from the substrate surface and facing each other, and having a rectangular shape consisting of an upper surface substantially parallel to the substrate surface and connected to the pair of side surfaces, are adjacent to each other. The two second electrodes cover the both side surfaces of the partition and a part of the upper surface, and are electrically separated from each other on the upper surface of the partition, to obtain an organic electroluminescence display device. Can be

According to another embodiment of the present invention, a plurality of first electrodes extending in a predetermined direction on a substrate surface, and a plurality of first electrodes extending in a direction intersecting the electrodes are provided on the substrate surface. A plurality of partitions arranged at intervals from each other, an organic layer disposed between the partitions, and a second layer formed on each organic layer.
Forming a plurality of first electrodes on the surface of the substrate, wherein the plurality of first electrodes are formed on a surface of the substrate, and the plurality of first electrodes are spaced apart from each other in a direction intersecting with the first electrodes. Forming a partition having a smaller width than the partition on the upper surface of each partition, and forming an organic layer and a second layer on the partition after forming the narrow partition on the partition. Forming an electrode layer, covering the exposed surfaces of the partition and the narrow partition, removing at least a portion of the narrow partition covered with the organic layer and the second electrode, and separating the two from each other. Organic layer and second
And a method of manufacturing an organic electroluminescent display device.

As described above, in the present invention, the second electrodes are formed on both side surfaces of the partition, and the second electrode is electrically insulated only on the upper surface of the partition.
As described above, since both side surfaces of the partition are covered with the second electrode, the mechanical strength of the partition can be improved. Further, since there is no need to provide an overhang portion on the partition,
Partition walls can be miniaturized.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, an organic electroluminescent display device according to an embodiment of the present invention includes a transparent glass substrate 10 and an ITO or the like formed on one surface of the glass substrate. The first electrode 11 is provided. Here, the first electrode 11 has a plurality of striped electrode structures extending in the left-right direction (predetermined direction) in the figure, operates as an anode electrode, and is sometimes called a lower electrode.

On the first electrode 11, insulating partition walls 12 made of photoresist are arranged at predetermined intervals in a direction crossing the extending direction (predetermined direction) of the first electrode 11. Have been. As is clear from the figure,
Each partition 12 is arranged in a stripe shape in a direction orthogonal to a predetermined direction, and the glass substrate 10 and the first electrode 11
Has a rectangular cross section having a pair of side surfaces substantially upright and facing each other, and an upper surface connected to both side surfaces.

As shown, an organic layer 13 and a second electrode 14 are sequentially laminated so as to cover the first electrode 11 between the partition walls 12, the side surfaces of the partition wall 12, and a part of the upper surface of the partition wall 12. Have been. Here, the organic layer 13 and the second electrode 1
4 denotes an adjacent organic layer 13 on the upper surface of each partition 12.
And the second electrode 14 is mechanically separated, so that adjacent second electrodes 14 are electrically insulated from each other.

The organic layer 13 is actually composed of an organic hole transport layer, an organic layer, and an organic electron transport layer, and a voltage is applied to the first electrode 11 and the second electrode 14. Then it emits light. In this connection, the second electrode 14 disposed on the organic layer 13 operates as a cathode electrode,
The intersection between the first electrode 11 and the second electrode 14 corresponds to a pixel.

Furthermore, in the case of the illustrated example, the second electrode 1
4 and the exposed upper surface of the partition 12 are made of SiO ₂
Is covered with a protective film 15 formed by the above.

Thus, the mechanical strength of the partition 13 is significantly improved by making the sectional shape of the partition 12 substantially rectangular and covering both side surfaces of the partition 12 with the organic layer 13 and the second electrode 14. In addition, since there is no need to provide a hangover portion in the partition 12 itself, the interval between the partition 12 can be reduced. Therefore, in the illustrated example, the partition 12 can be formed finely.

Referring to FIG. 2, a method of manufacturing an organic electroluminescent display device according to an embodiment of the present invention will be described in the order of steps. In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. In FIG. 2A, as in the case of FIG. 1, a stripe-shaped first electrode 11 formed of an ITO film is formed on one surface of a transparent glass substrate 10 in the horizontal direction of the drawing. . Also,
The first electrode 11 is orthogonal to the first electrode 11.
On the upper side, partition walls 12 arranged at intervals from each other are provided, and an element region for emitting light is formed in a region between the partition walls 12.

The illustrated partition wall 12 is formed of a positive photoresist and has a thickness of 2 to 5 μm and a thickness of 3 to 5 μm.
It has a width of 0 μm.

In the example shown in FIG. 2A, the narrow partition 1 having a width smaller than the width of the partition 12 is provided on the upper surface of the partition 12.
2 'is formed. The illustrated narrow width partition 12 ′
It has a reverse tapered cross section, and has a narrow width at the lower portion in contact with the partition wall 11 and a wider width at the upper portion than at the lower portion. Illustrated narrow partition 12 '
Has a thickness of 15 μm and a width of 15 μm. The reverse tapered narrow-width partition wall 12 ′ as shown in FIG.
It can be formed by selectively etching a negative type dry film resist.

Referring to FIG. 2B, an organic layer is formed on the element region sandwiched between the partition walls 12, both side surfaces of each partition wall 12, a part of the upper surface of the partition wall 12, and the upper surface of the narrow partition wall 12 '. 13
The layer forming the second electrode 14 is formed by vapor deposition. As described above, the narrow partition 1 is provided on the upper surface of the partition 12.
By mounting the 2 ′, the organic layer 13 and the second electrode 14 are formed on the upper surface of the partition 12 on which the narrow partition 12 ′ is provided.
Are not formed, the organic layer 13 and the second electrode 14
Is provided on the narrow partition wall 12 '.

In this state, as shown in FIG. 2 (C), by moving the adhesive roller 16 in the extending direction of the partition wall 12, the narrow partition wall 12 'is formed on the organic material on the narrow partition wall 12'. It is removed by lift-off together with the layer 13 and the second electrode 14 layer. As described above, in a state in which the narrow partitions 12 ′ are removed, the second electrodes 14 adjacent to each other are completely insulated completely on the upper surface of the partitions 12.

Subsequently, as shown in FIG. 2D, a protective film 15 made of SiO ₂ is formed on the exposed upper surfaces of the second electrode 14 and the partition 12, and the protective film 15 is
2 covers the exposed portion on the upper surface.

In this configuration, the organic layer 13 and the second electrode layer 14 are provided so as to cover both side surfaces of the
Electrical insulation between the second electrodes 14 can be performed only by the upper surface of the second electrode 2. When this configuration is adopted, the partition 1
There is no need to configure the cross-sectional shape of the partition 2 in a reverse tapered shape or to have an overhang portion, so that there is an advantage that the mechanical strength of the partition wall 12 itself can be improved.

With reference to FIG. 3, a method of manufacturing an organic electroluminescent display device according to another embodiment of the present invention will be described in the order of steps. In FIG. 3A, FIG.
Similarly to (A), a first electrode 11 is provided on one surface of a glass substrate 10, and a partition 12 is provided so as to cross the first electrode 11. A narrow partition wall 12 'is mounted on the upper surface. Also in this example, the narrow-width partition wall 12 'has an inversely tapered cross section.

In the state shown in FIG. 3A, the organic layer 13 and the second
3B, an organic layer 13 and a second electrode 14 are deposited on the element region between the barrier ribs 12 as shown in FIG. ′.

Subsequently, as shown in FIG. 3 (C), the grinding roller 20 is moved in the longitudinal direction of the narrow partition wall 12 ', so that the second electrode layer 14 and the organic layer 13 are removed by grinding together with a part of the narrow partition wall 12 '. In this state, the narrow partition wall 12 'partially remains on the partition wall 12, and as a result, the narrow partition wall 1'
The upper surface of 2 'is exposed.

FIG. 3D shows the exposed second electrode 14.
Further, a protective film 15 made of SiO ₂ is formed on the upper surface of the narrow partition wall 12 ′.

According to this embodiment, as in the case of FIG. 2, the mechanical strength of the partition wall 12 can be improved, and the narrow partition wall 12 'is also covered with the protective film 15. 12 'can be prevented from being affected.

Referring to FIG. 4, there is shown a sectional structure of a partition 12 and a narrow partition 12 'according to another embodiment of the present invention. The illustrated partition wall 12 has a rectangular cross section and a narrow partition wall 12 ′ provided on the upper surface of the partition wall 12.
Also have a rectangular cross section.

In this example, the partition 12 and the narrow partition 12 '
Can be formed of the same material, for example, a positive photoresist. In addition, the organic layer 13 and the second
After the formation of the electrode 14 layer of FIG. 2, the narrow barrier rib 12 ′, the organic layer 13 on the narrow barrier rib 12 ′, and the second electrode 14 layer are removed by mechanical polishing or an adsorption method, thereby obtaining FIG.
An organic electroluminescent display device having a structure similar to that shown in FIG. 3 can be manufactured.

[0036]

Referring to FIG. 2 again, a more specific embodiment of the present invention will be described. First, a glass substrate having a thickness of 1.1 mm was used as the glass substrate 10.
In this case, as the glass forming the glass substrate 10,
It is desirable to use an alkali-free glass that adsorbs little water, but it was confirmed that an inexpensive low-alkali glass substrate or soda-lime glass may be used if the substrate is sufficiently dried. Next, an ITO film having a thickness of 100 nm was formed on one surface of the glass substrate 10 by a sputtering method.
Subsequently, the first electrode 11 was formed by patterning the ITO film in a stripe shape in the left-right direction of FIG. 2A by using a photolithography technique. In this case, the ITO film forming the first electrode 11 operates as an anode electrode, and transmits light emitted from the organic layer 13 and extracts the light to the outside of the glass substrate 10. It is desirable that the light transmittance be higher.

The ITO as the illustrated first electrode 11
The pattern has a line pitch of 0.33 mm and a line width of 0.3 mm.
It had a length of 3 mm and a length of 28 mm, and 128 were formed on the glass substrate 10.

Next, a partition wall 12 was formed so as to cross the ITO film pattern constituting the first electrode 11. In this example, a 5 μm thick resist film was formed by spin-coating a positive photoresist sold by Tokyo Ohka Kogyo Co., Ltd. under the trade name “OFPR800”. Here, the positive photoresist described above had a yield point of 150 ° C. Subsequently, the positive photoresist is heat-treated at 90 ° C. for 30 minutes.
Exposure to light with a wavelength of 36 nm at an exposure of 60 mJ, development and washing with a 2.38% TMAH solution for 70 seconds, followed by baking at a temperature of 130 ° C. for 30 minutes, Width 3 orthogonal to first electrode 11
A resist barrier 12 having a thickness of 0 μm was formed. At this time, the partition 1
The pattern No. 2 had a pitch of 0.33 mm and a height of 2 to 5 μm, and both side surfaces had a state of being substantially upright with respect to the substrate.

After the formation of the partition 12, the product name "NIT-32"
5), a 15 μm-thick negative type dry film resist manufactured and sold by Nippon Synthetic Chemical Co., Ltd. on a glass substrate 10 at a temperature of 85 to 115 ° C.,
The laminate was laminated at a pressure of kg / cm ² at a speed of 1 to 3 m / min. Next, after aligning the photomask so that the pattern of the negative type dry film resist is located on the partition wall 12, the light having a wavelength of 300 to 400 nm is used.
Exposure is performed at an exposure amount of 00 mJ. Further, with the resist-coated side down, using a 0.8 to 1.2% aqueous solution of Na ₂ CO ₃ for 30 seconds, developing and washing with water, and then heating at 120 ° C.
Baking for 30 minutes, and a narrow partition wall 1 having a width of 15 μm.
2 ′ was formed.

Subsequently, with the partition wall 12 facing downward, the substrate subjected to the above processing is fixed to a substrate holder of a vacuum evaporation apparatus, and N, N'-diphenyl-N, N 'is placed on a resistance heating boat. -Bis (α-naphthyl) -1,1′-biphenyl-4,4′-diamine (abbreviated as α-NPD). A tris (8-quinolinolato) aluminum complex (hereinafter referred to as Alq3) is put in another resistance heating boat, the inside of the vacuum evaporation apparatus is evacuated to about 1 × 10 ⁻⁶ Torr or less, and the α-NPD of α-NPD is rotated while rotating the substrate holder. An electric current is passed through the resistance heating boat to heat it, and an α-NPD layer having a thickness of 50 μm is deposited. Then, while continuing to rotate the substrate holder, a current was passed through the resistance heating boat containing Alq3, and a 50 nm thick Al was deposited on the surface of the α-NPD layer.
Deposit q3 layer. Thus, the organic layer 13 including the organic light emitting layer and the electron transport layer was formed by vapor deposition.

Further, while the substrate thus treated and the resistance heating boat containing magnesium are loaded into the vacuum evaporation apparatus, silver is put into another resistance heating boat, and the ratio of magnesium: silver is set to 10: 1. Co-deposited at different deposition rates to deposit a second electrode material. Next, as shown in FIG. 2 (C), the narrow partition wall 12 ′ is brought into contact with the narrow partition wall 12 ′ by a roller provided with an adhesive substance, while the narrow partition wall 12 ′ shown in FIG. 12 ′ while rotating it in the longitudinal direction, thereby narrowing the narrow partition 12 ′.
It is removed together with the upper organic layer and the second electrode layer.

Next, as shown in FIG. 2 (D), SiO ₂ was put into a resistance heating boat, and a protective film of SiO ₂ having a thickness of 800 nm was formed.

[0043]

As described above, according to the present invention, by covering the side surfaces of the partition walls formed at intervals from each other on the first electrode so as to cross the first electrode,
There is an advantage that the mechanical strength of the partition can be improved and electrical insulation between adjacent second electrodes on the upper surface of the partition can be reliably performed. Also, since it is not necessary to form an overhang portion on the partition wall,
Fine processing of the partition walls is also possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross section of an organic electroluminescence display device according to one embodiment of the present invention.

FIGS. 2A to 2D are views for explaining the manufacturing method shown in FIG. 1 in the order of steps;

FIGS. 3A to 3D are diagrams for explaining a method of manufacturing an organic electroluminescent display device according to another embodiment of the present invention in the order of steps.

FIG. 4 is a view illustrating a method of manufacturing an organic electroluminescent display device according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Glass substrate 11 1st electrode 12 Partition 12 'Narrow partition 13 Organic layer 14 2nd electrode 15 Protective film 16 Adhesive roller 20 Grinding roller

Claims (12)

[Claims] 1. A plurality of first electrodes extending in a predetermined direction on a substrate surface, and a plurality of first electrodes spaced apart from each other on the substrate surface in a direction intersecting the electrodes. A partition, an organic layer disposed between the partitions, and a second electrode formed on each organic layer, wherein the partition is upright from the substrate surface in cross section, and faces each other. The two second electrodes adjacent to each other have a rectangular shape consisting of a pair of side surfaces and an upper surface substantially parallel to the substrate surface and connected to the pair of side surfaces, and are formed on both side surfaces of the partition wall. And an organic electroluminescent display device that partially covers the upper surface and is electrically separated from each other at the upper surface of the partition wall. 2. The device according to claim 1, wherein the surface of the second electrode and the upper surface of the partition not covered with the second electrode are:
An organic electroluminescent display device which is covered with a protective film. 3. The organic electroluminescence according to claim 2, wherein the organic layer located below the second electrode covers both side surfaces of the partition and a part of the upper surface of the partition. Display device. 4. An organic electroluminescent display device according to claim 3, wherein said organic layer is constituted by an organic light emitting film and an electron transporting film. 5. The organic electroluminescence display device according to claim 1, wherein the partition is formed of a positive photoresist. 6. The device according to claim 1, wherein the substrate and the first
Wherein the first electrode is transparent and the second electrode is opaque. 7. The organic electro-optical device according to claim 1, wherein a narrow partition which is narrower than a width of the partition is left in a portion of the upper surface of the partition which is not covered with the second electrode. Luminescence display device. 8. A plurality of first electrodes extending in a predetermined direction on a substrate surface, and a plurality of first electrodes spaced apart from each other on the substrate surface in a direction intersecting the electrodes. In a method of manufacturing an organic electroluminescence display device including a partition, an organic layer disposed between the partitions, and a second electrode formed on each organic layer, the method further includes: Forming on the substrate surface;
Forming the plurality of partitions at intervals from each other in a direction intersecting the electrodes, and forming, on the upper surface of each of the partitions, a narrow partition having a width smaller than that of the partitions, and Forming an organic layer and a second electrode layer after forming the narrow partition, covering the exposed surfaces of the partition and the narrow partition, and forming at least the organic layer and the second layer of the narrow partition. Removing the portion covered with the electrode to form the organic layer and the second electrode separated from each other. A method for manufacturing an organic electroluminescent display device, comprising: 9. An electrode forming step according to claim 8, wherein said removing step removes all said narrow partition walls to form a second electrode in which said second electrode layer is electrically insulated from each other. A method of manufacturing an organic electroluminescent display device, characterized in that: 10. The organic electroluminescent device according to claim 8, wherein the partition wall formed in the partition wall forming step is substantially upright with respect to the surface of the substrate and has side surfaces facing each other. A method for manufacturing a luminescence display device. 11. The narrow partition according to claim 8, wherein the narrow partition formed in the step of forming the narrow partition has a sectional shape.
A method for manufacturing an organic electroluminescent display device, wherein an overhang portion is formed. 12. An organic electroluminescent display device according to claim 8, wherein said partition is formed of a positive photoresist and said narrow partition is formed of a negative photoresist. Production method.