JP2001043981A - Display device and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the resistance of a first electrode without impairing the displaying quality by forming the first electrode formed oppositely to a second electrode on a base, by stacking a base electrode and a guide electrode, and forming an insulating layer on the guide electrode, in a state that a boundary line where the guide electrode allows the base electrode to be exposed, and a boundary line where the insulating layer allows the base electrode to be exposed are substantially same as each other. SOLUTION: A guide electrode 12 is formed at both sides on a base electrode 11 in a crossing area of an opening 15 and an insulating layer 14 exists covering the guide electrode 12. A boundary line 16 of the guide electrode 12 exposing the base electrode 11 and a boundary line 16 of the insulating layer exposing the base electrode 11 are the same. The guide electrode 12 is formed on the substantially whole base electrode 111 excluding a part where the base electrode 11 relating to the display of a picture element is exposed, that is, an opening part 15, and the guide electrode 12 exists in a completely covered state by the insulating layer. A display element free from the unevenness of brightness, and with superior color purity and the luminescent efficiency can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device having a first electrode formed on a substrate and a second electrode provided opposite to the first electrode.

[0002]

2. Description of the Related Art As an image display device (display) replacing a large and heavy cathode ray tube, a light and thin so-called flat panel display has attracted attention.

[0003] Liquid crystal displays (LCDs) have become widespread as flat panel displays, and there is an electrochromic display (ECD) as a similar non-emissive display, and a plasma display panel (PDP) has recently attracted attention. )
And an electroluminescent display (ELD). Among electroluminescent displays, organic electroluminescent displays are particularly active in research and development because they can provide high brightness and can be used as full-color displays.

[0004] These flat panel displays are display devices for converting image information electric signals into image light, and many of them employ a time-division driving method as a driving method. The time division driving method is a method in which a screen is divided into a plurality of element electrodes, and a driving voltage is applied to these element electrodes in a time division manner. A dot matrix type electrode configuration for realizing this is an X, Y matrix structure in which generally parallel striped electrodes intersect at right angles between a pair of opposing electrode substrates. Such opposed electrodes are sometimes referred to as X electrodes and Y electrodes, but may also be referred to as first electrodes and second electrodes.

In a flat panel display, a transparent substrate and a transparent electrode are often used for one substrate in order to take out display light from one substrate side, but the transparent electrode is generally not often highly conductive. In addition, when the size of the display is increased, the conductivity of the electrodes may be insufficient.

[0006]

In order to compensate for the lack of conductivity of the electrodes, steps such as forming a base electrode on a substrate, forming a guide electrode thereon, and further forming an insulating layer are performed. However, it is necessary to repeat operations such as application of a resist, patterning, and etching after forming a material film for each, and the process is complicated.

The present invention forms an efficient guide electrode and shortens the process.

[0008]

A display device according to the present invention is a display device including a first electrode formed on a substrate and a second electrode provided opposite to the first electrode. The first electrode is formed by laminating at least a base electrode and a guide electrode, an insulating layer is formed on the guide electrode, and the boundary between the guide electrode exposing the base electrode and the insulating layer are formed on the base. The boundary line exposing the electrode is substantially the same.

Further, the method for manufacturing a display device according to the present invention is a method for manufacturing a display device as described above, wherein a step of patterning a laminated film of a base electrode and a guide electrode at once, and an step of insulating the patterned laminated film on the laminated film The method includes a step of forming a pattern of a layer and a step of exposing a part of the base electrode by removing an exposed part of the guide electrode.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a display device including a first electrode formed on a substrate and a second electrode provided opposite to the first electrode. For example, an LCD, an ECD, an ELD, a display device using an organic electroluminescent element, and the like are applicable.

The present invention is particularly directed to a first electrode formed on a substrate, a thin film layer formed on the first electrode, the light emitting layer comprising at least an organic compound, and a second electrode formed on the thin film layer. It can be suitably used for a display device including an organic electroluminescent element including electrodes.

In the present invention, the first electrode is formed by laminating at least a base electrode and a guide electrode, and an insulating layer is formed on the guide electrode. The guide electrode and the insulating layer are provided only on a part of the base electrode, and have an opening where the base electrode is exposed. When the display light is extracted from the transparent substrate side, the base electrode needs to be transparent. The display light passes through the transparent base electrode and the transparent substrate through the opening and is extracted to the outside.

The present invention is characterized in that a boundary line at which the guide electrode exposes the base electrode is substantially the same as a boundary line at which the insulating layer exposes the base electrode. More specifically, the shape of the opening where the guide electrode exposes the base electrode is substantially the same as the shape of the opening where the insulating layer exposes the base electrode. Here, “substantially the same” means that not only a case where the shape of each boundary line or the opening is completely the same but also a case where the shape is substantially the same. For example, when the guide electrode layer is etched by making the insulating layer function as a resist as described below, the boundary line may not exactly match that of the insulating layer due to the guide electrode layer being under-etched. Can be regarded as substantially the same.

That is, in the present invention, the guide electrode is formed on substantially all the portions on the base electrode except for the portion where the base electrode related to the pixel display is exposed, ie, the opening. And the guide electrodes are all in a state of being covered with the insulating layer. For this reason, the resistance of the first electrode can be reduced most efficiently without deteriorating the display quality of the display device. Regarding the electrode lead portion, for example, a guide electrode and an insulating layer are formed at an edge portion of the base electrode, and contact with an external circuit near the central portion where the base electrode is exposed is achieved. It is possible to obtain

The relationship between the guide electrode and the insulating layer formed on the base electrode of the present invention will be described with reference to the drawings. FIG.
Is a plan view of the patterned base electrode 11,
Exposed opening 1 of base electrode to be a pixel portion for display
5 and the portion other than the exposed portion is covered with the insulating layer 14. A guide electrode exists on a portion of the base electrode which is covered with the insulating layer. In this case, since the guide electrode exists between both sides of the base electrode, the opening, and the opening, the guide electrode exists as a longitudinal section along the base electrode, which contributes to lowering the resistance of the first electrode. Is big.

FIG. 2 is a plan view illustrating another example of the present invention, in which the boundary between the guide electrode exposing the base electrode and the boundary between the insulating layer exposing the base electrode is the same. . In this case, the insulating layer 14 is formed in a pattern crossing the base electrode 11, and the guide electrode 12 exists below the insulating layer on the base electrode. That is, the guide electrodes are provided intermittently at regular intervals on the base electrode, but can contribute to lowering the resistance of the first electrode as a whole.

FIG. 3 is a sectional view taken along the line XX 'of FIG. 1 which is covered with the insulating layer and does not cross the opening, and a sectional view of the portion covered with the insulating layer of FIG. In this portion, the base electrode 11 and the guide electrode 12 have a laminated structure and are covered with an insulating layer 14. When the second electrode is patterned by the partition method, it is preferable to form a partition on this insulating layer.

On the other hand, FIG. 4 shows a sectional view taken along the line YY 'of FIG. In this portion, guide electrodes are formed on both sides of the base electrode, and an insulating layer exists so as to cover the guide electrodes. That is, the boundary line 16 at which the guide electrode exposes the base electrode is the same as the boundary line 16 at which the insulating layer exposes the base electrode. This indicates that a guide electrode is formed on the base electrode covered with the insulating layer.

FIGS. 5 and 6 show still another example in which the guide electrode exposes the base electrode and the insulating layer exposes the base electrode. It is a top view explaining. That is, red (R), green (G),
The blue (B) light emitting area is not a stripe pattern,
This shows a case of a so-called delta arrangement. For example, a base electrode forming a pixel of one color is composed of a wide portion serving as a pixel and a narrow portion connecting the same, and these are formed for three colors. I have. The pixel portion is connected at a narrow portion of the base electrode, and a guide electrode and an insulating layer are formed on the base electrode so as to penetrate the pixel, which is preferable for reducing the resistance of the first electrode. In this state, as shown in FIG. 1, a guide electrode and an insulating layer are also formed on the side portion of the pixel portion to further reduce the resistance.

In the present invention, as the base electrode material, a transparent conductive material is preferable, and tin oxide, zinc oxide, vanadium oxide, indium oxide, indium tin oxide (IT
O) can be used. In display applications where patterning is performed, it is preferable to use ITO having excellent workability for the base electrode. ITO may contain a small amount of metal such as silver or gold to improve conductivity.

In the present invention, as the guide electrode material, aluminum, zinc, indium, tin, silver, gold,
Copper, chromium, titanium, nickel and the like are used. The guide electrode can also be used by laminating two or more of these metals. A chromium / aluminum or chromium / copper laminated film can be used to reduce resistance, prevent reflection, adhere to a metal film, and facilitate etching. It can be mentioned as a preferable example from the viewpoint. In the present invention, since the guide electrode is formed in all parts except the opening on the base electrode, when a metal to be blackened such as chromium is used, the guide electrode also functions as a black matrix, and the display device Contributes to the improvement of contrast.

Various inorganic and organic materials are used for the insulating layer. As inorganic materials, manganese oxide, vanadium oxide, titanium oxide, including silicon oxide,
Oxide materials such as chromium oxide, semiconductor materials such as silicon and gallium arsenide, glass materials, ceramic materials, and the like, as organic materials, polyvinyl-based, polyimide-based,
Polymer materials such as polystyrene, acrylic, novolak, and silicone are preferably used.

The cross-sectional shape of the insulating layer near the boundary where the insulating layer exposes the base electrode is not particularly limited, but is preferably a forward tapered shape.
Taking the organic electroluminescent device as an example, when the cross section of the insulating layer has a forward tapered shape, the organic thin film layer 17 and the second electrode 18 are formed smoothly even near the boundary 16 as shown in FIG. You. The taper angle θ is 80 ° or less,
Further, it is preferably 60 ° or less, more preferably 45 ° or less. On the other hand, when the cross section of the insulating layer is vertical, as shown in FIG. 16, the thickness of the organic thin film layer 17 tends to become thin near the boundary line 16, and light emission in this region may become unstable. There is. In an extreme case, the organic thin film layer breaks down near the boundary line, and a region where the organic thin film layer does not exist is formed, and the base electrode (first electrode) or the guide electrode and the second electrode are short-circuited. May be formed. Further, since the thickness of the second electrode tends to be thinner at the side wall portion of the insulating layer, the resistance value of the second electrode may be increased. Such a problem can be avoided by devising a method of forming the organic thin film layer and the second electrode. However, the cross section of the insulating layer has an inversely tapered shape (a state in which the taper angle θ exceeds 90 °). Not very good.

The guide electrode and the insulating layer have the same boundary line for exposing the base electrode, and the display device having the same opening shape can be manufactured by the following steps.

A metal material for forming a guide electrode is deposited on the ITO film on the substrate on which the ITO film serving as a transparent base electrode has been formed (FIG. 7). The method for forming the guide electrode is not limited, and a sputtering method, a laminating method, a plating method, or the like can be used in addition to the evaporation method.

The laminated film of the base electrode and the guide electrode is patterned at once by a photolithographic method (FIG. 8). Next, after forming a lift-off resist pattern on the patterned laminated film (FIG. 9), an insulating layer is formed on the entire surface (FIG. 10). When the lift-off resist is removed, an opening in the insulating layer is formed, and the guide electrode is exposed (FIG. 1).
1). Using the formed insulating layer as a resist, the exposed portion of the guide electrode is removed by etching to expose the base electrode (FIG. 12). The patterning method of the insulating layer is
The method is not limited to such a method using a lift-off resist, and a method of coating an insulating layer material and etching it by a photolithographic method, or performing a patterning process by exposing and developing using a photosensitive insulating layer material Can also.

The portion of the guide electrode on the base electrode where the insulating layer is exposed can be removed by etching the patterned insulating layer as a resist, but this depends on the material used for the base electrode and the guide electrode. This is performed using an etching selectivity. Since an ITO film is often used as the base electrode, it is preferable to use a metal material having a large etching selectivity with ITO as the guide electrode. Since what is used as an etching agent is related, it is necessary to consider a combination of a guide electrode material and an etching agent.
That is, an alkaline solution can be used for Al, and a solution composed of cerium ammonium nitrate, nitric acid, and water is used for Cr, as is known. Further, as long as it is Cu, a solution of ferric chloride can be used. Since the ITO film may be etched to some extent, the etching conditions for the guide electrode can be considered to be broad.

According to the conventional method, it is necessary to repeat a photolithography process at least three times, such as patterning of a base electrode, patterning of a guide electrode, and patterning of an insulating layer. Only two photolithography steps for patterning the film and patterning the insulating layer are performed.

The opening where the guide electrode and the insulating layer expose the base electrode corresponds to a unit for forming one pixel of the display device. For example, in a display device using an organic electroluminescent element, a thin film layer including a light emitting layer made of at least an organic compound is formed in the opening, and a second electrode is formed on the thin film layer so as to intersect with the first electrode. The display device is formed.

The steps of the method for manufacturing a display device of the present invention shown in FIGS. 7 to 12 are performed in the case where a thin film layer including at least a light emitting layer made of an organic compound or a second electrode is formed by patterning in a pixel portion. The method can be used as a method for forming an alignment mark of a mask. That is, I
A plurality of alignment marks formed by patterning a laminated film composed of the TO film and the guide electrode material film are formed at appropriate positions on the substrate. In patterning the ITO film, there is an example in which an alignment mark for a subsequent process is formed, but the mark made of the ITO film is not easily detectable with visible light. Therefore, forming an alignment mark composed of an ITO film and a guide electrode material film with high visible light detection is useful for facilitating a patterning operation in a later step including formation of a light emitting layer. In the case of the present invention, these alignment marks can be used while being covered with an insulating layer.

[0031]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited by these.

Example 1 An ITO substrate having a transparent ITO film having a thickness of 130 nm formed on a surface of an alkali-free glass substrate having a thickness of 1.1 mm by a sputtering deposition method was cut into a size of 120 × 100 mm. An aluminum film of about 100 nm was formed on the ITO transparent film of this substrate by a vacuum evaporation method. This I
A photoresist was applied on the laminated film of the TO film / aluminum film, and was exposed and developed by a normal photolithography method to pattern the photoresist. After removing unnecessary portions of the ITO film / aluminum film laminated film by etching,
By removing the photoresist, the laminated film is 90m long
m and a width of 80 μm were patterned to form a first electrode. 816 of these stripe patterns were formed at a pitch of 100 μm.

At the time of patterning the laminated film of the ITO film / aluminum film, at least two cross-shaped marks serving as alignment marks were formed at the corners of the glass substrate.
The cross-shaped mark is 20 μm thick and 0.5 mm long
And

Next, a photoresist for lift-off (ZPN1100, Zeon Corporation) was applied to the entire surface to a thickness of 3 μm. The photomask used for patterning the resist has an opening having a width of 65 μm and a length of 235 μm in the width direction.
Those arranged at a pitch of 00 μm and at a pitch of 300 μm in the length direction were used. The photomask was positioned and patterned on the laminated film on which the stripe pattern was formed such that the width of the photomask was 65 μm at the center thereof. The feature of this lift-off resist is that it has an inverse tapered pattern. Subsequently, a silicon oxide film having a thickness of 150 nm was formed on the entire surface of the glass substrate by an electron beam evaporation method to form an insulating layer. When the substrate is ultrasonically cleaned in acetone, the lift-off resist is dissolved, the silicon oxide film thereon is removed, and the aluminum film is exposed. Thus, the insulating layer has openings of 65 μm in width and 235 μm in length corresponding to the pattern arrangement of the photomask used for patterning the lift-off resist, arranged at a pitch of 100 μm in the width direction and at a pitch of 300 in the length direction. It became something.

The insulating layer was subjected to resist etching and alkali etching. The exposed portion of the aluminum film was removed to expose the ITO film. The ITO film serves as a base electrode, and the aluminum film serves as a guide electrode. The boundary line at which the guide electrode exposes the base electrode is the same as the boundary line at which the insulating layer exposes the base electrode.
It was the same in a rectangular shape of μm × 235 μm.

The substrate on which the base electrode, the guide electrode, and the insulating layer were formed and the alignment mark was formed at the same time was washed and then set in a vacuum evaporation machine. In the vacuum evaporation machine, a shadow mask for forming a light emitting layer, a shadow mask for forming a second electrode, a thin film layer including a light emitting layer, and evaporation sources of a material for forming a second electrode can be set.

The thin film layer is formed by a vacuum evaporation method using a resistance wire heating method. The degree of vacuum at this time is 2 × 10 ⁻⁴ Pa or less.
During the evaporation, the substrate was rotated with respect to the evaporation source. First, as a hole transporting layer, copper phthalocyanine of 15 nm and bis (N
-Ethylcarbazole) was deposited on the entire surface of the substrate to a thickness of 60 nm.

Next, a light emitting layer is formed. The shadow mask used is formed as follows. That is, by depositing a Ni—Co alloy on an electroforming matrix by electroforming, a reinforcing wire 3 having a stripe-shaped opening 32 as shown in FIG.
3 has a structure in which a mask portion and a reinforcing line are formed in the same plane. The outline of this shadow mask is 12
0 × 84 mm, and the thickness of the mask portion 31 is 25 μm. 272 stripe-shaped openings 32 having a length of 64 mm and a width of 100 μm are arranged at a pitch of 300 μm. In each of the stripe-shaped openings, reinforcing wires 33 having a width of 20 μm and crossing the openings at right angles are formed at a pitch of 1.8 mm. Further, marks for alignment with alignment marks formed on the substrate were formed in at least two places. The shadow mask is fixed to a stainless steel frame 34 having the same outer shape and a width of 4 mm.

The shadow mask for forming the light emitting layer was arranged in front of the substrate so that both were closely attached to each other, and a ferrite magnet (YBM-1B, manufactured by Hitachi Metals, Ltd.) was arranged behind the substrate. At this time, the alignment mark on the substrate is arranged so that the position reference of the shadow mask coincides, the first stripe-shaped electrode is positioned at the center of the stripe-shaped opening of the shadow mask, and the reinforcing wire is formed of the insulating layer. To match a position,
Both are aligned.

A red (R) light emitting layer is formed on the substrate arranged as described above. The host material of the R light emitting layer is
8-hydroxyquinoline aluminum complex (Alq3)
(20 nm) and 1% by weight as a guest material.
Of 4- (dicyanomethylene) -2-methyl-6- (p-
Dope with dimethylaminostyryl) -4-pyran (DCM).

Next, in a state where the arrangement of the shadow mask for forming the light emitting layer is shifted by one pitch of the first electrode, Alq3 (21 nm) similar to the R light emitting layer is used for the host material, and guest materials are 1, 3, 5 , 7,8-Pentamethyl-4,4-
A green (G) light emitting layer using difluoro-4-bora-3a, 4a-diaza-s-indacene (PM546) was formed. Further, the shadow mask was moved by one pitch to form a blue (B) light emitting layer. As the B light emitting layer, 4,4 ′
-Bis (2,2'-diphenylvinyl) diphenyl (D
PVBi) was used. In this case, only DPVBi was deposited to a thickness of 20 nm without using a guest material. Thereafter, 35 nm of DPVBi and 10 nm of Alq ₃ were deposited on the entire surface of the substrate, and finally, the thin film layer was exposed to lithium vapor to form an electron transport layer.

For patterning the second electrode, a shadow mask having a structure in which a gap exists between one surface of the mask portion 31 and the reinforcing wire 33 as shown in FIG. 14 was used. The outer shape of this shadow mask is 120 × 84 mm, the thickness of the mask portion is 100 μm, the length is 100 mm, and the width is 250 μm.
200 m-shaped striped openings are arranged at a pitch of 300 μm. On the mask portion, a mesh-like reinforcing line having a regular hexagonal structure having a width of 40 μm, a thickness of 35 μm, and a distance between two opposing sides of 200 μm is formed.
The height of the gap is equal to the thickness of the mask portion and is 100 μm. A mark for making it correspond to the alignment mark was also formed on the mask portion of this shadow mask in the same manner as in the case of the shadow mask for forming the light emitting layer. This shadow mask is used by being fixed to a frame 34 made of stainless steel.

The degree of vacuum during the deposition of the second electrode is 3 × 10 ^-4 P
Below a, the substrate was rotated with respect to two evaporation sources during evaporation. Similarly to the patterning of the light emitting layer, the second electrode mask is arranged in front of the substrate on which the thin film layer is formed, and both are brought into close contact with each other at a predetermined position using the alignment mark. Was placed. In this state, aluminum was deposited to a thickness of 240 nm to pattern the second electrode. The second electrode is arranged in a direction orthogonal to the first electrode that is patterned into a plurality of stripes arranged at intervals, and is patterned into a plurality of stripes arranged at intervals.

Through the above steps, patterned R, G, and B light emitting layers are formed on the 816 striped first electrodes, and the striped second electrodes having a width of 250 μm and a pitch of 300 μm orthogonal to the first electrodes. Were arranged in a simple matrix type stripe color organic electroluminescent device in which 200 were arranged. Since the three light-emitting regions R, G, and B form one pixel, this light-emitting element has 272 × 200 pixels at a pitch of 300 μm.

When the display device comprising the organic electroluminescent device was evaluated, a display device having reduced luminance unevenness and high luminous efficiency as compared with the case where no guide electrode was provided was obtained.

Example 2 In this example, polyimide was used as the material for forming the insulating layer. After patterning the laminated film of the ITO film / aluminum film into a pattern as the first electrode in the same manner as in Example 1, a polyimide photosensitive coating agent (UR-3100, manufactured by Toray Industries, Inc.) is applied on the entire surface of the substrate. Was applied by a spin coat method and prebaked in a clean oven at 80 ° C. for 1 hour under a nitrogen atmosphere. Next, Example 1
UV light exposure through the same photomask used for the patterning of the lift-off resist, photo-curing the portion remaining as an insulating layer, and a developing solution (DV, manufactured by Toray Industries, Inc.)
-505). Thereafter, the resultant was baked in a clean oven at 180 ° C. for 30 minutes and further at 250 ° C. for 30 minutes to form an insulating layer.

Using this polyimide insulating layer as a resist, a display device was fabricated in the same manner as in Example 1 except that the exposed portion of the aluminum film was removed by etching. Also in this case, a display device comprising an organic electroluminescent element having reduced luminance unevenness and high luminous efficiency as compared with the case where no guide electrode was provided was obtained. Further, the relatively thick insulating layer functioned as a spacer, which prevented the shadow mask from damaging the thin film layer, so that the number of non-light emitting pixels was reduced as compared with Example 1, and a more favorable organic electroluminescent device Was obtained.

EXAMPLE 3 Chromium of about 50 nm and copper of about 7 were deposited on the ITO transparent film on the same substrate as in Example 1 by a sputtering deposition method.
0 nm was formed. A photoresist was applied on the laminated film of the ITO film / chromium film / copper film, and exposed and developed by a usual photolithography method to pattern the photoresist. Unnecessary portions of the laminated film were removed by etching with a ferric chloride-based solution, and then the photoresist was removed, whereby the laminated film was patterned into a stripe shape having a length of 90 mm and a width of 80 μm to form a first electrode. 816 of these stripe patterns were formed at a pitch of 100 μm. As in Example 1, at least two cross-shaped marks serving as alignment marks were formed at the corners of the glass substrate.

Next, an insulating layer made of silicon oxide was patterned in the same manner as in Example 1. The resist was applied to the insulating layer, and first, the exposed portion of the copper film was removed by etching with a ferric chloride-based solution to expose the chromium film.
Further, the exposed portion of the chromium film was removed by etching with a mixed solution of cerium ammonium nitrate, nitric acid and water, thereby exposing the ITO film. ITO serves as a base electrode, and a chromium / copper laminated film serves as a guide electrode. The boundary line at which the guide electrode exposes the base electrode was the same as the boundary line at which the insulating layer exposed the base electrode, and the opening shape was the same in a rectangular shape of 65 μm × 235 μm. At this time, since the adhesion between the guide electrode, the base electrode, and the insulating layer was improved, defects such as chipping of the insulating layer were further reduced as compared with the first embodiment.

In the subsequent steps, a display device was manufactured in the same manner as in Example 1. Also in this case, a display device including an organic electroluminescent element having reduced luminance unevenness and high luminous efficiency as compared with the case without the guide electrode was obtained. Further, chrome performed a function like a black matrix, and the display contrast was further improved as compared with the first embodiment.

Example 4 In this example, a positive photoresist was used as a material for forming the insulating layer. After patterning the laminated film of the ITO film / aluminum film into a pattern as the first electrode in the same manner as in Example 2, a novolak-based positive photoresist (manufactured by Tokyo Ohka Kogyo Co., Ltd., OF
PR-800) was applied to a thickness of about 3 μm by spin coating, and prebaked on a hot plate at 80 ° C. for 90 minutes. Next, ultraviolet light exposure through a photomask,
Development was performed using a developer (NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Thereafter, baking was performed at 180 ° C. for 8 minutes on a hot plate to form an insulating layer.

A display device was manufactured in the same manner as in Example 2 except for the above. Also in this case, compared to the case without the guide electrode,
A display device with reduced luminance unevenness and high luminous efficiency was obtained. Further, as in Example 2, the effect of preventing the shadow mask from damaging the thin film layer was also confirmed. The cross section of this insulating layer had a forward tapered shape of about 45 °, and uniform light emission was observed over the entire light emitting region.

Example 5 In this example, a display device was manufactured in the same manner as in Example 4, except that the lift-off resist used in Example 1 was used as a material for forming the insulating layer. Since the cross section of the insulating layer has a reverse tapered shape of about 90 ° to 110 °, a portion where the organic thin film layer such as the hole transport layer and the light emitting layer becomes relatively thin near the boundary line is formed. Although light emission became slightly unstable, luminance unevenness was reduced as compared with the case where there was no guide electrode, and a display device with high luminous efficiency was obtained. In addition, the effect of preventing the shadow mask from damaging the thin film layer was also confirmed.

[0054]

A display device in which the boundary line at which the guide electrode exposes the base electrode and the boundary line at which the insulating layer exposes the base electrode is the same is advantageous for lowering the resistance of the first electrode.
A display device including an organic electroluminescent element having less luminance unevenness, excellent color purity, and high luminous efficiency can be obtained. Furthermore, by making the cross section of the insulating layer a forward tapered shape, instability of light emission near the boundary line can be avoided. In addition, by patterning the laminated film of the base electrode and the guide electrode, patterning the insulating layer thereon, and then removing the guide electrode using the insulating layer pattern, it can be manufactured in a small number of steps. It is advantageous also in the process.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an opening formed by the same boundary line between a guide electrode and an insulating layer on a base electrode.

FIG. 2 is a plan view showing the same configuration of a guide electrode and an insulating layer on a base electrode.

FIG. 3 is a sectional view taken along line X-X ′ of FIG. 1 or FIG. 2;

FIG. 4 is a sectional view taken along line Y-Y ′ of FIG. 1;

FIG. 5 is a plan view showing another example of an opening formed at the same boundary line between a guide electrode and an insulating layer on a base electrode.

FIG. 6 is a sectional view taken along line X-X ′ of FIG. 5;

FIG. 7 is a sectional view showing a laminated structure of a base electrode film / guide electrode film formed on the entire surface of a substrate.

FIG. 8 is a sectional view showing a patterned laminated structure film.

FIG. 9 is a sectional view showing a state in which a lift-off resist is patterned on the layered structure film pattern.

FIG. 10 is a sectional view showing a state in which an insulating layer is formed on a substrate after a lift-off resist pattern is formed.

FIG. 11 is a cross-sectional view showing a state where an insulating layer is patterned by lift-off.

FIG. 12 is a cross-sectional view illustrating a state where a guide electrode is removed by etching using an insulating layer pattern as a resist to expose a base electrode.

FIG. 13 is a plan view showing an example of a shadow mask for patterning a light emitting layer.

FIG. 14 is a plan view showing an example of a shadow mask for patterning a second electrode.

FIG. 15 is an enlarged cross-sectional view illustrating a state where the cross section of the insulating layer has a forward tapered shape.

FIG. 16 is an enlarged cross-sectional view illustrating a state where a cross section of an insulating layer is vertical.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Substrate 11 Base electrode 12 Guide electrode 13 Lift-off resist 14 Insulating layer 15 Opening 16 Boundary line 17 Organic thin film layer 18 Second electrode 31 Mask part 32 Shadow mask opening 33 Reinforcement line 34 Frame

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/10 H05B 33/10 33/14 33/14 A 33/22 33/22 Z

Claims (9)

[Claims] 1. A display device comprising: a first electrode formed on a substrate; and a second electrode provided to face the first electrode, wherein the first electrode includes at least a base electrode and a guide electrode. Wherein an insulating layer is formed on the guide electrode, and a boundary line at which the guide electrode exposes the base electrode and a boundary line at which the insulating layer exposes the base electrode are substantially formed. A display device, which is the same. 2. A display device comprising: a first electrode formed on a substrate; a thin film layer including at least an organic compound formed on the first electrode; and a light emitting layer formed on the thin film layer. The display device according to claim 1, wherein the display device is a display device including an organic electroluminescent element including a second electrode. 3. The display device according to claim 1, wherein an opening shape of the guide electrode exposing the base electrode is substantially the same as an opening shape of the insulating layer exposing the base electrode. 4. The display device according to claim 1, wherein the base electrode is transparent. 5. The display device according to claim 1, wherein a cross section of the insulating layer near the boundary line has a forward tapered shape. 6. A display device comprising: a first electrode formed on a substrate; and a second electrode provided to face the first electrode, wherein the first electrode has at least a base electrode and a guide electrode laminated. A method of patterning a laminated film of a base electrode and a guide electrode at once, and a step of forming a pattern of an insulating layer on the patterned laminated film,
Removing the exposed portion of the guide electrode to expose a part of the base electrode. 7. The method according to claim 6, wherein the patterning of the laminated film of the base electrode and the guide electrode is performed by a photolithography method. 8. The method according to claim 6, wherein the patterning of the insulating layer is performed by a photolithography method. 9. The method according to claim 6, wherein the exposed portion of the guide electrode is removed by etching using the patterned insulating layer as a mask.