JP2003066871A - Organic el display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize high contrast and high definition without depending upon the performance of an organic EL element also in a simple matrix driving system. SOLUTION: A device has a substrate 10, 1st wires 1 formed on one main surface of the substrate 10, 2nd wires 3 formed across the 1st wires 1, and pixels 5 arranged corresponding to the intersections of the 1st wires 1 and 2nd wires 3. Each pixel 5 has a switching element 8 which turns on when the 1st wire is selected to allow a signal current supplied from the 2nd wire 3 flow and an organic EL element 9 which emits light by receiving the signal current from the switching element 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate, a first wiring formed on one main surface of the substrate, a second wiring intersecting with the first wiring, and a second wiring. The present invention relates to a simple matrix drive type organic EL display device having a plurality of pixels arranged corresponding to the intersection of one wiring and the second wiring, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, an organic EL display device using an organic electroluminescent element (hereinafter referred to as an organic EL element) 100 as shown in FIG.

In the organic EL element 100, for example, an anode 102 made of a transparent material such as ITO (indium tin oxide) is formed on a transparent glass substrate 101, and a hole transport layer, a light emitting layer, and an electron transport layer are formed on the anode 102. An organic EL light emitting layer 103 composed of a layer or the like is formed, and a cathode 104 made of a low work function material or the like is formed on the organic EL light emitting layer 103.
And the cathode 104 is the extraction electrode 10
5 is electrically connected.

When the organic EL element 100 emits light, a positive voltage is applied to the anode 102 and a negative voltage is applied to the cathode 104, that is, between the anode 102 and the cathode 104. By passing a direct current, the holes injected from the anode 102 and the electrons injected from the cathode 104 respectively reach the organic EL light emitting layer 103, where the holes and the electrons are recombined. As a result, light with a predetermined wavelength is generated,
The light is emitted to the outside from the transparent glass substrate 101 side.

This organic EL element is essentially an anode 10
When a forward voltage is applied from 2 to the cathode 104, a large current flows and light is emitted, while a reverse voltage is applied, almost no current flows. FIG. 8 shows current-voltage characteristics of the organic EL element having a good reverse bias characteristic.

Organic E having excellent reverse bias characteristics
FIG. 9 shows an example in which a so-called simple matrix drive type organic EL display device is configured using L elements. This organic EL display device 110 is a 3 × 3 dot simple matrix drive system, and includes scan lines 111A, scan lines 111B and 111C as scan lines 111, and data lines 112A, data lines 112B and data as data lines 112. Line 112C and these scan lines 111
An organic EL element 113 is connected at each intersection of the data line 112 and the data line 112 to form a pixel. Organic EL that pixel has
The element 113 has an anode connected to the data line 112 and a cathode connected to the scan line 111. In addition, in FIG. 9, the organic EL element 113 is represented by a diode. Further, the pixel position is represented by a matrix of data lines 112 and scan lines 111.

In this organic EL display device, the organic EL of {scan line 111B, data line 112B}
In order to cause the element 113 to emit light, the scan line 111B is selected by the scan line driving circuit (not shown) and the data line 112B is selected by the data line driving circuit (not shown). As a result, a predetermined current flows into the organic EL element 113 of the pixel on the {scan line 111B, data line 112B}, and the desired pixel can emit light. On the other hand, in the other pixels, at least one of the data line 112 and the scan line 111 is in a non-selected state, so that no current flows and no light is emitted.

[0008]

By the way, the bias characteristics of the organic EL element vary depending on the material forming the organic EL element and the film forming conditions. Therefore, for example, as shown in FIG. 10, there is also an organic EL element having poor reverse bias characteristics.

When an organic EL element having poor reverse bias characteristics is used in the organic EL display device described above,
As shown in 1, the current (leakage current) flows in the reverse direction in the defective organic EL element. As a result, the original selected pixel {scan line 111B, data line 1
12B} emits light, a voltage is applied to non-selected pixels, for example, {scan line 11B, data line 112C}, and the non-selected pixels emit light erroneously, resulting in deterioration of contrast and deterioration of display quality. .

Therefore, in order to construct an organic EL display device of a simple matrix drive system having a good contrast, it is required to adopt an organic EL element having an ideal reverse bias characteristic as shown in FIG. It

However, since such an organic EL element requires strict control of film forming conditions and narrows the range of material selection, it causes a decrease in productivity and an increase in cost. There is a problem that it is difficult.

Therefore, in a simple matrix drive type organic EL display device, an organic EL display device having a reverse bias characteristic or the like is used.
A fundamental solution is desired to improve the contrast without depending on the performance of the L element.

Further, in the conventional organic EL display device, in order to arrange the organic EL elements in a matrix, it is necessary to pattern each of the anode and the cathode sandwiching the organic EL light emitting layer into a predetermined stripe shape, for example. There is. For example, taking the organic EL element shown in FIG. 7 as an example, it is necessary to form a cathode and then pattern it after forming the organic EL light emitting layer.

However, since the organic material used for the organic EL light emitting layer is very weak against heat, moisture, oxygen, solvent, etc., fine particles are not formed on the organic EL light emitting layer without damaging the organic EL light emitting layer. It is extremely difficult to form a patterned cathode.

For example, when the cathode is patterned by the photolithography method or the like, there is a problem that the organic EL light emitting layer is damaged and the light emitting function of the organic EL element is impaired. Further, as a method for forming a cathode film that does not affect the organic EL light emitting layer as much as possible, there are a sputtering method using a metal mask, a vapor deposition method, and the like. This hinders high definition of the device. Further, various researches have been conducted on a method of forming a fine cathode without damaging the organic EL light emitting layer, but any of these methods complicates the manufacturing process of the organic EL display device and reduces the manufacturing cost. There is a risk of rising.

Therefore, the present invention has been proposed in view of such conventional circumstances, and realizes high contrast and high definition without depending on the performance of the organic EL element even in the so-called simple matrix drive system. It is an object of the present invention to provide an organic EL display device and a manufacturing method thereof.

[0017]

In order to achieve the above object, an organic EL display device according to the present invention includes a substrate, a first wiring formed on one main surface of the substrate, and the first wiring. Second wiring formed so as to intersect with the wiring, and a plurality of pixels arranged corresponding to an intersection of the first wiring and the second wiring, wherein the pixel is the first wiring. A wiring element which is conductive when the first wiring is selected and allows the signal current supplied from the second wiring to flow, and an organic EL element which receives the signal current from the switching element and emits light. And

The organic EL element originally has a light emitting function and also has a function of preventing a leak current due to a reverse bias characteristic in an organic EL display device of a simple matrix drive system. The basic idea of the present invention is to separate the leak current prevention function from the organic EL element and allow another element to perform the leak current prevention function.

That is, in the organic EL display device according to the present invention, each pixel has an organic EL element and a switching element, the organic EL element has only a light emitting function, and the leak current preventing function is different. The switching element arranged in the pixel is responsible.

Therefore, even if a defective organic EL element is used in the organic EL display device of the simple matrix drive system, the switching element is arranged in each pixel, so that the leak current of the organic EL element causes False light emission of non-selected pixels is prevented.

Further, since the cathode side of the organic EL element is connected to the ground potential, patterning of the cathode of the organic EL element becomes unnecessary.

Further, in the method for manufacturing an organic EL display device according to the present invention, the first wiring, the second wiring, the first wiring and the second wiring are formed on one main surface of the substrate. A first step of forming a switching element at a position corresponding to the intersection,
Organic EL capable of receiving a signal current from the switching element formed in the first step and emitting light
And a second step of forming an element.

In the method of manufacturing an organic EL display device as described above, before forming an organic EL element which is weak against heat or solvent,
Since the first wiring, the second wiring, and the switching element are formed on the substrate in advance, the first wiring, the second wiring, and the switching element are miniaturized without considering deterioration of the constituent material of the organic EL element. Is possible. Further, when forming the organic EL element, patterning after forming the cathode is not necessary.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an organic EL device to which the present invention is applied
As a display device, a small organic EL display device of 3 × 3 dots will be described as an example. This organic EL display device
As shown in FIG. 1, scan line 1 includes scan line 1A, scan line 1B, and scan line 1C.
And a scan line driving circuit 2 for driving these scan lines 1 and a data line 3 as a data line 3 formed by intersecting these scan lines 1 in a matrix.
A, a data line 3B and a data line 3C, a data line driving circuit 4 for driving these data lines 3,
The plurality of pixels 5 are provided corresponding to the intersections of the scan lines 1 and the data lines 3 and are electrically connected to the scan lines 1 and the data lines 3.

The organic EL display device is turned on / off by an image data signal from the data line drive circuit 4.
However, the FET (field-effect t) connected to the data line 3A, the data line 3B, and the data line 3C, respectively.
ransistor) 6A, 6B and 6C and FET 6A, 6B
And power supply voltage Vdd for supplying power to the data line 3 via 6C, and constant current circuits 7A, 7A for converting the current from the power supply voltage Vdd into a constant current and supplying it to each data line 3.
B and 7C.

The pixel 5 is switched by the drive signal from the scan line 1 and is in the ON state, that is, when the scan line 1 is selected, the data line 3 is selected.
It has a TFT (thin-film transistor) 8 as a switching element for flowing a current based on the image signal from the device, and an organic EL element 9 whose anode side is connected to the TFT 8 and whose cathode side is connected to the ground potential. .

The source of the TFT 8 is connected to the data line 3, and is connected to the power supply voltage Vdd via the data line 3. The drain of the TFT 8 is connected to the anode of the organic EL element 9 and is connected to the ground potential via the organic EL element 9. Further, the gate of the TFT 8 is connected to the scan line 1 and is controlled to be ON / OFF by the scan line drive circuit 2.

The switching element included in the pixel 5 is not limited to the above-mentioned TFT, but a so-called MIM (metal-insula) in which an insulator is sandwiched between electrodes is used.
It is also possible to use a thin film switching element having a tor-metal structure. In addition to thin film switching elements, switching elements include MEMS (micro electro-mechanical
It is also possible to use a mechanical switching element or the like that utilizes an ical system technology.

The sectional structure of the pixel 5 is shown in FIG.
The pixel 5 is formed on a substrate 10 made of a transparent material such as glass,
On the first interlayer insulating film 11 so as to cover the TFT 8, the substrate 10 and the first interlayer insulating film 11 formed so as to cover the TFT 8, and the source electrode 12 and the drain electrode 13 extracted from the TFT 8. It has the formed second interlayer insulating film 14 and the organic EL element 9 formed on the second interlayer insulating film 14.

The TFT 8 is stacked on the gate electrode 15 formed on the substrate 10 made of glass or the like, the gate insulating film 16 overlaid on the upper surface thereof, and above the gate electrode 15 via the gate insulating film 16. And a semiconductor thin film 17. The TFT 8 shown in FIG. 2 is a TFT having a so-called bottom gate structure, and includes a source S, a channel Ch and a drain D which serve as a path for a current supplied to the organic EL element 9. The source S has an opening in the first interlayer insulating film 11 immediately above and is connected to the data line 3 (not shown) via the source electrode 12. Further, the drain D is connected to the anode of the organic EL element 9 via the drain electrode 13 with an opening in the first interlayer insulating film 11 immediately above. The channel Ch is located just above the gate electrode 15.

The organic EL element 9 includes the second interlayer insulating film 14
A transparent electrode 18, an organic EL light emitting layer 19, and a metal electrode 20 are sequentially laminated on top.

Since the transparent electrode 18 is connected to the drain electrode 13 of the TFT 8, it functions as an anode of the organic EL element 9 and is made of a transparent conductive film such as ITO.

The organic EL light emitting layer 19 is composed of, for example, a hole transport layer, a light emitting layer, and an electron transport layer, which are laminated in this order. The structure of the organic EL light emitting layer 19 is not particularly limited, and any structure such as a laminated structure of a hole transport layer and a light emitting layer, a laminated structure of a light emitting layer and an electron transport layer, and a single layer structure of the light emitting layer. It doesn't matter.

The metal electrode 20 functions as a cathode of the organic EL element 9, and is formed in a single flat surface over the substantially entire surface of the substrate 10 without being separated for each pixel 5.
The second interlayer insulating film 14 and the transparent electrode 18 are the third
And the metal electrode 20 is formed on the plane on the third interlayer insulating film 21. Thereby, the metal electrode 20 and the transparent electrode 18 are insulated.

In the organic EL display device having the above-mentioned structure, the scan line driving circuit 2 and the data line driving circuit 4 apply a signal voltage to the scan lines 1 and the data lines 3 in time series to select the signals. The pixel 5 corresponding to the intersection of the selected scan line 1 and the selected data line 3 is caused to emit light.

Here, a case where the pixel 5 provided corresponding to the intersection of the scan line 1B and the data line 3B is caused to emit light will be described as an example. In addition, in FIG.
The position of the pixel 5 is represented by a matrix of the data line 3 and the scan line 1.

First, by driving the data line driving circuit 4, a signal current corresponding to image data is supplied to the data line 3B, and the data line 3B is brought into a selected state. That is, from the data line driving circuit 4 to the FET
By applying a predetermined voltage between the gate electrodes of 6B, FET6B is turned on, and the source of FET6B
A current corresponding to this voltage is made to flow from the power supply voltage Vdd capable of supplying a voltage of 20 V, for example, between the drains. FET6
The signal current that has passed through B is made uniform to a constant current value by passing through the constant current circuit 7B. From this constant current circuit 7B, the current required for the emission brightness flows into the data line 3B. On the other hand, the data line 3A and the data line 3C are in the non-selected state.

In this state, the scan line drive circuit 2 is driven to supply a scan signal to the scan line 1B. As a result, the pixel 5 on the {scan line 1B, data line 3B} is specified, and a predetermined voltage is applied from the scan line 1B between the gate electrodes of the TFT 8 included in the pixel 5 to turn the TFT 8 on. As a result, the signal current from the data line 3B flows between the source and drain of the TFT 8 and further flows into the organic EL element 9 connected to the drain of the TFT 8. As a result, light is generated by recombination of holes and electrons in the organic EL light emitting layer 19 of the organic EL element 9, and the pixel 5 of the desired {scan line 1B, data line 3B} can emit light. .

At this time, in the non-selected pixels other than the pixel 5 of the {scan line 1B, data line 3B}, the signal current corresponding to the image data is not supplied to the data line 3 or the scan line 1 is not selected. As a result, the TFT 8 is turned off, so that the current supply to the organic EL element 9 is cut off and the organic EL element 9 is not emitted.

In this organic EL display device, the scan line 1 and the data line 3 are insulated from each other by the TFT 8 arranged in each pixel 5, and at the intersection of the selected scan line 1 and the selected data line 3. Corresponding TF
A signal current flows between the source and drain of only T8. That is, the organic EL to which the present invention is applied
The display device applies a forward current to only the organic EL element 9 of the desired pixel 5 to emit light. On the other hand, since the organic EL element 9 of the non-selected pixel is configured so that neither the forward current nor the reverse current flows, the organic EL element 9 of the conventional simple matrix drive type does not have the reverse current. It is possible to prevent the current from flowing into the scan line and / or the data line in the non-selected state due to the leak current flowing through the organic EL element having the poor bias characteristic.

Therefore, the organic E which is inferior in reverse bias characteristics
Even when the L element is used, the erroneous light emission of the non-selected pixel due to the leak current is prevented, so that a high-contrast organic EL display device can be provided without depending on the quality of the reverse bias characteristic of the organic EL element. Can be realized.

Further, since the organic EL element is not required to have a strict reverse bias characteristic, the film forming conditions of the organic EL element can be relaxed. As a result, the manufacture of the organic EL element, and further the manufacture of the organic EL display device is facilitated, and the cost of the organic EL display device can be reduced.

In the organic EL display device to which the present invention is applied, as shown in FIG.
While connected to FT8, the cathode is connected to ground potential. Therefore, as shown in FIG. 2, the metal electrode 20 as the cathode does not need to be patterned in a stripe shape as in the conventional organic EL display device, and one flat plate is provided over the entire organic EL display device. It will be good if it is in a state. That is, the patterning of the metal electrode 20 formed on the organic EL light emitting layer 19 becomes unnecessary. Therefore, the organic EL display device to which the present invention is applied can achieve high definition without damaging the organic material forming the organic EL element 9.

Hereinafter, a method of manufacturing the above-mentioned organic EL display device will be described.

First, as shown in FIG. 3, data lines 3 and scan lines 1 are formed in stripes on a substrate 10 made of, for example, a transparent glass substrate so as to be orthogonal to each other. The data line 3 and the scan line 1 are made of, for example, Al or Al alloy.

Next, as shown in FIG. 4, on the substrate 10,
Gate electrode 15, gate insulating film 16, and semiconductor thin film 1
7 are sequentially deposited and patterned to form a TFT 8.
Further, impurities are introduced into the regions of the semiconductor thin film 17 on both sides of the gate electrode 13 to form the source S and the drain D. In addition, a first film is formed above the substrate 10 so as to cover the TFT 8.
The inter-layer insulating film 11 is formed.

Next, the portions corresponding to the source S and the drain D of the first interlayer insulating film 11 are opened by, for example, etching to form openings. The source electrode 12 connected to the source S and the drain electrode 13 connected to the drain D through this opening are formed by patterning into a predetermined shape.

Next, a second film is formed above the substrate 10 so as to cover the TFT 8, the source electrode 12 and the drain electrode 13.
The interlayer insulating film 14 is formed. This second interlayer insulating film 1
A portion corresponding to the drain electrode 13 of 4 is opened by, for example, etching to form an opening.

A thin film forming process such as photolithography can be used for the steps up to this point.

Next, as shown in FIG. 5, the transparent electrode 1 is formed on the second interlayer insulating film 14 in the region corresponding to the pixel 5.
8 and the organic EL light emitting layer 19 are sequentially formed into a predetermined shape.

Specifically, on the transparent electrode 18 formed of ITO by a sputtering method or the like, red (R),
An organic EL device is formed, for example, by vapor deposition while masking so that the three colors of green (G) and blue (B) form a stripe shape.
The light emitting layer 19 is formed.

Next, as shown in FIG. 6, by vapor-depositing Al, for example, over substantially the entire upper surface of the substrate 10,
A metal electrode 20 to be a cathode is formed.

Note that, in FIGS. 4, 5 and 6, the gate insulating film 16, the first interlayer insulating film 11 and the second interlayer insulating film 14 are omitted for ease of explanation. There is.

In the manufacturing method as described above, the scan line 1, the data line 3 and the TFT 8 which is a switching element are formed in advance before forming the organic EL light emitting layer 19 which is weak against heat and solvent. Therefore, the organic EL light emitting layer 1
It is possible to form extremely fine scan lines 1, data lines 3 and TFTs 8 by using a thin film forming process such as exposure and development etching with a photoresist without considering deterioration of the constituent materials of 9.

After forming the organic EL light emitting layer 19 by vapor deposition using a mask or the like, the organic EL element 9 is completed only by depositing it on the substrate 10 without patterning the metal electrode 20. That is, in the conventional display device of the simple matrix drive system, the metal electrode serving as the cathode must be formed independently after the formation of the organic EL light emitting layer, but in the present invention, the cathode of all the organic EL elements is formed. Is connected to the ground potential, the patterning of the cathode is unnecessary.

Therefore, it is possible to easily manufacture a high-definition organic EL display device while minimizing damage to the organic EL light emitting layer 19.

In addition, organic E, which is relatively inferior in reverse bias characteristics,
Since it is possible to increase the contrast even with an L element,
The film forming conditions of the organic EL element can be relaxed.

In the above description, the organic EL display device of 3 × 3 dots is taken as an example, but the present invention is not limited to this, and the number of data lines 3 and scan lines 1 is increased or decreased. As a result, the size can be arbitrarily set to m × n dots.

[0059]

As is apparent from the above description, in the organic EL display device according to the present invention, the switching element is arranged in each pixel even if there is an organic EL element having a poor reverse bias characteristic. The erroneous light emission of the non-selected pixel due to the leak current of the organic EL element is prevented, and only the desired pixel can emit light. In addition, the organic EL according to the present invention
The display device does not require patterning of the cathode of the organic EL element.

Therefore, according to the present invention, a high contrast is realized without depending on the reverse bias characteristics of the organic EL element, and a high-definition simple matrix drive type organic EL display is provided while suppressing damage to the organic EL element. A device can be provided.

Further, in the method for manufacturing an organic EL display device according to the present invention, the first wiring, the second wiring and the switching element are preliminarily formed on the substrate before the organic EL element, which is weak against heat or solvent, is formed. Therefore, it is possible to miniaturize the first wiring, the second wiring, and the switching element without considering deterioration of the constituent material of the organic EL element. In addition, organic EL
When forming the device, patterning after forming the cathode is unnecessary. Therefore, according to the present invention, the organic EL
A high-definition organic EL display device can be manufactured without damaging the element. Further, according to the present invention, it is possible to manufacture an organic EL display device that realizes high contrast without depending on the reverse bias characteristic of the organic EL element.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an organic EL display device to which the present invention is applied.

FIG. 2 is a cross-sectional view of a pixel.

FIG. 3 shows a data line 3 and a scan line 1 on a substrate.
FIG. 6 is a perspective view showing a state in which the is formed.

FIG. 4 is a perspective view showing a state in which a TFT is formed on a substrate.

FIG. 5 is a perspective view showing a state in which an organic EL light emitting layer is formed on a substrate.

FIG. 6 is an exploded perspective view showing a state in which a metal electrode is formed as a cathode above a substrate.

FIG. 7 is a schematic cross-sectional view of a main part of an organic EL element.

FIG. 8 is a current-voltage characteristic diagram of an organic EL element showing ideal reverse bias characteristics.

9 is an organic E having a reverse bias characteristic as shown in FIG.
In the conventional organic EL display device of the simple matrix drive system configured by using the L element, {scan line 11
B, a data line 112B} is a circuit diagram in a state in which the pixels are made to emit light.

FIG. 10 is a current-voltage characteristic diagram of an organic EL element having a poor reverse bias characteristic.

FIG. 11 shows a pixel of {scan line 11B, data line 112B} which emits light in a conventional simple matrix drive type organic EL display device configured by using an organic EL element having a reverse bias characteristic as shown in FIG. It is a circuit diagram of the state which was made to.

[Explanation of symbols]

1 scan line, 2 scan line drive circuit, 3
Data line, 4 data line drive circuit, 5 pixels,
6 FET, 7 constant current circuit, 8 TFT, 9 organic E
L element, 10 substrate, 11 first interlayer insulating film, 12
Source electrode, 13 drain electrode, 14 second interlayer insulating film, 15 gate electrode, 16 gate insulating film, 17
Semiconductor thin film, 18 transparent electrode, 19 organic EL light emitting layer,
20 metal electrode, 21 third interlayer insulating film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/30 G09G 3/30 J H01L 29/786 H05B 33/10 H05B 33/10 33/14 A 33 / 14 33/26 Z 33/26 H01L 29/78 614 F term (reference) 3K007 AB17 AB18 BA06 CA01 CB01 DA00 DB03 EB00 FA01 5C080 AA06 BB05 DD09 DD30 FF10 FF11 JJ02 JJ05 JJ06 5C094 AA06 AA31 AA43 BA03 BA04 CA110 DA14 CA29 CA04 DA19 CA04 AA27 BB20 CC08 DD02 NN71

Claims (15)

[Claims] 1. A substrate, a first wiring formed on a main surface of the substrate, and a second wiring formed so as to intersect with the first wiring.
Line and a plurality of pixels arranged corresponding to the intersections of the first line and the second line, and the pixel is electrically connected when the first line is selected. And an organic EL element which receives a signal current from the switching element and emits light.
Display device. 2. The organic E according to claim 1, wherein the switching element is a thin film switching element.
L display device. 3. The organic EL display device according to claim 1, wherein the switching element is a mechanical switching element utilizing a MEMS technique. 4. The organic EL element is formed by stacking at least an anode, an organic EL light emitting layer and a cathode in this order, the anode is connected to the switching element, and the cathode is connected to a ground potential. The organic EL display device according to claim 1, wherein the organic EL display device is provided. 5. The organic EL display device according to claim 4, wherein the cathode is formed over the entire one main surface of the substrate. 6. The first wiring is a scan line supplied with a scan signal, and the second wiring is a data line supplied with an image data signal. Organic EL
Display device. 7. The organic EL display device according to claim 6, wherein a constant current circuit is connected to the data line. 8. The organic EL display device according to claim 1, wherein the organic EL display device is of a simple matrix drive type. 9. A first wiring, a second wiring, and a switching element are formed at a position corresponding to an intersection of the first wiring and the second wiring on one main surface of the substrate. Organic EL capable of receiving the signal current from the switching element formed in the first step and the first step and emitting light.
A second step of forming an element, the method for manufacturing an organic EL display device. 10. The first wiring, the second wiring, and the switching element in the first step,
The method of manufacturing an organic EL display device according to claim 9, wherein the organic EL display device is formed by a thin film forming process. 11. The method of manufacturing an organic EL display device according to claim 10, wherein the switching element is a thin film switching element. 12. The manufacturing method of an organic EL display device according to claim 9, wherein in the second step, the organic EL element is formed by stacking an anode, an organic EL light emitting layer and a cathode in this order. Method. 13. The method of manufacturing an organic EL display device according to claim 12, wherein the cathode is formed over the entire main surface of the substrate. 14. The first wiring is a scan line to which a scan signal is supplied, and the second wiring is a data line to which an image data signal is supplied. Organic EL
Manufacturing method of display device. 15. The method of manufacturing an organic EL display device according to claim 14, wherein a constant current circuit is connected to the data line.