KR100785976B1 - Manufacturing method for organic el element - Google Patents

Abstract

In the method of manufacturing the organic EL device 100 formed by stacking the anode 20, the organic film 30, and the cathode 40 on the substrate 10, the cathode 40 of the organic EL device 100 may be a positive electrode, The negative electrode 20 is a negative electrode, and a negative electrode presenting process for applying a first voltage V1 between the negative electrode 40 and the positive electrode 20 to present a defective part, and a negative electrode after the defective part presenting process. A measurement process of measuring the leakage current value by applying a second voltage V2 between the cathode 40 and the anode 20 and making the positive electrode 40 and the negative electrode 20 negative, and the measured leakage current value It consists of the determination process of determining the defect of the organic electroluminescent element 100 on the basis. In the measurement process, when the second voltage V2 is applied, the leak current is measured within a time period in which the leak current of the defective product becomes larger than the leak current of the regular product.

Organic EL element, organic film, leakage current value, defect part presenting process, glass substrate

Description

Manufacturing method of organic EL element {MANUFACTURING METHOD FOR ORGANIC EL ELEMENT}

1 is a cross-sectional view of an organic EL device according to an embodiment of the present invention.

2 is a process flowchart showing a method of manufacturing the organic EL device of the embodiment;

3A to 3D are histograms showing the leakage current values for the regular and defective products when the first voltage V1 = 28 V and the second voltage V2 = 15 V. FIG.

4A to 4D are histograms showing the leakage current values for regular and defective products when the first voltage V1 = 28 V and the second voltage V2 = 15 V. FIG.

Fig. 5 shows the relationship between the cathode film thickness and the success rate of opening at various reverse voltages.

<Explanation of symbols for main parts of the drawings>

10: substrate

20: anode

30: organic film

40: cathode

100: organic EL device

[Document 1] Japanese Patent No. 3552522

TECHNICAL FIELD This invention relates to the manufacturing method of organic electroluminescent (electroluminescent) element.

The organic EL device is generally formed by laminating an anode and an organic film including a light emitting layer and a cathode on a substrate. However, since organic materials are used, alteration and diffusion are likely to occur due to an electric field or heat. This may happen. In particular, even when the initial leak current is at a detection limit (for example, 1 mA or less), there may be a case where a short circuit of the upper and lower electrodes occurs suddenly at the time of driving.

As a countermeasure, conventionally, an aging process is performed in which a negative electrode is used as a positive electrode and a positive electrode as a negative electrode, and a reverse voltage opposite to the forward voltage applied at the time of light emission is applied between the anodes, and a defective portion is present to open and break. Then, the manufacturing method which applies the reverse voltage to organic electroluminescent element, measures the leakage current which flows between an anode, and performs the process of performing a defect determination based on this leakage current value is proposed. This manufacturing method is disclosed in Japanese Patent No. 3552522, for example.

According to this, a leak current is generated in the defective portion by application of a reverse voltage, and the thermal expansion of the organic material causes thermal expansion by the Joule heat caused by the leak current. Here, a defective part is a site | part in which an organic film becomes thin and it is easy to short-circuit normally by the level | step difference, such as a foreign material.

As a result of this expansion, the cathode made of Al or the like scatters, and the defective portion is electrically opened so that leakage does not occur during driving. The opened defect part becomes a local non-light emitting part because the cathode is scattered, but there is no effect on the display quality if it cannot be distinguished with the naked eye.

However, performing the aging step of open breaking the cathode as described above is effective for an element structure in which the defect portion is open broken by the application of a reverse voltage.

However, according to the examination of the present inventors, it was found experimentally that there is an element structure in which such open destruction does not occur even when the above method is used, and the above method cannot be applied to such a thing.

An element structure in which open fracture does not occur is a structure in which a cathode is formed into a thick film. When the cathode is thickened, open fracture does not occur over an arbitrary film thickness from the above-described open fracture mechanism. Specifically, it was found that the film thickness of such a cathode was 135 nm or more.

The concrete experiment examination which this inventor performed about this is described. In the general organic EL device structure, one in which the cathode was changed in thickness was fabricated, and an aging step for open breaking was performed. In addition, since the opening is more likely to occur as the reverse voltage applied in the aging step increases, the reverse voltage is also changed.

Fig. 5 shows the relationship between the thickness of the cathode film and the success rate of opening at various reverse voltages. When the reverse voltage applied in the aging step is 16 V, the cathode film thickness can be opened to 100 nm.

Moreover, opening can be made possible to 135 nm by making reverse voltage 18V or more. Moreover, as a result of observation, it was confirmed that this opening is due to the scattering of the negative electrode as mentioned above.

Here, in the structure where the cathode film thickness is 135 nm or more, the defect portion is electrically opened by setting the reverse voltage to 22V. However, the defect part at this time was largely visible by the scattering of a negative electrode, and became a quality defect.

For example, if the diameter of the hole formed by opening is 150 micrometers or less, it will not be visually recognized and there will be no problem in display quality, but if it is larger than that, it will become a problem that an open part can be visually recognized.

This is considered to be due to the increase in Joule heat by increasing the applied reverse voltage to 22 V and the increase in the amount of scattering of the cathode. In other words, it was found that the element structure having a cathode thickness of 135 nm or more cannot be opened from the standpoint of display quality even when an aging step of open breaking is employed.

In addition, according to Japanese Patent No. 3552522, the defective product is determined based on the leakage current value flowing when the reverse voltage is applied to the organic EL element after the aging process, that is, the regular product and the defective product are determined. For this reason, it is not applicable to the case of an element structure in which the cathode cannot be opened thickly to 135 nm or more.

Such thickening of the negative electrode is necessary from the viewpoint of lowering the resistance of the negative electrode. Therefore, even if open breakage does not occur due to the thickening of the cathode, a process of applying a reverse voltage before shipment is performed to make the defective part present and to remove the defective product, which is necessary to prevent short circuit defects in the market.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to suitably perform a defect determination by presenting a defective portion that is likely to leak in an organic EL device having a cathode having a film thickness that cannot be open-breaked in an aging process. do.

According to one aspect of the present disclosure, in the method for producing an organic EL device comprising a laminate of an anode, an organic film, and a cathode on a substrate, the cathode of the organic EL device is a positive electrode, the anode is a negative electrode, and between the cathode and the anode. After the defect part presenting step of applying the first voltage to the defect part to make the defective part present, and the defect part presenting step, the negative electrode is used as the positive electrode and the positive electrode as the negative electrode, and a second voltage is applied between the negative electrode and the positive electrode to provide the leakage current value. And a determination step of determining a failure of the organic EL element based on the measured leakage current value. In the measuring step, the leak current is measured within a time period when the leak current of the defective product becomes larger than the leak current of the regular product when the second voltage is applied.

According to this, since a defective product which leaks easily generate | occur | produce can be identified based on the leakage current value measured, defect determination can be performed suitably.

In addition, the cathode may have a thickness of 135 nm or more.

In addition, the second voltage may be equal to or less than the first voltage.

The second voltage is 28 V or less, and the time for which the leak current of the defective product becomes larger than the leak current of the regular product may be 100,000 seconds.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

The present inventors conducted preliminary experiments with respect to organic electroluminescent element. First, except that the film thickness of the cathode is 135 nm or more, using an organic EL element having a general configuration, the organic film is made thicker so that the defect portion does not occur, and the film thickness of the organic film is made thin so that the defect portion easily occurs. A plurality of defects were produced, respectively, and a defect part presenting step of presenting the defect part by applying a first voltage V1 as a reverse voltage between the cathode and the anode was performed.

Moreover, after this defect part presenting process, the 2nd voltage V2 as a reverse voltage was applied between these cathode products and the defect goods between a cathode and an anode, and the leakage current value which flowed at this time was measured.

Then, as shown in Figs. 3A to 3D (V2 = 15 V) and Figs. 4A to 4D (V2 = 28 V) described later, a clear difference is found in the magnitude of the leak current value measured in the genuine product and the defective product. It became. From this, it was found that it can be judged as a defective product when the measured leak current value is larger than the leak current value of the regular product.

In addition, the longer the elapsed time that elapses from after the defective part presenting process to the leakage current measuring step becomes, the smaller the magnitude of the leak current measured in the defective product becomes, and the difference between the regular product and the defective product becomes smaller. When looking at the distribution, it was found that the distribution overlapped, making it impossible to identify defective and genuine products.

The leak current value of this defective product is reduced by the elapsed time after the defective part present, but the detailed mechanism is unclear, but the inventors newly discovered.

Since the process is different between the conventional aging process and the defect determination, the time to wait until the leakage current measurement, storage during process stoppage, etc. is not specifically determined. In some cases, a time interval of one or more days may occur. However, when it takes such a long time, there exists a possibility that the difference of the leakage current between a genuine product and a defective product will not be discovered and cannot be determined.

Therefore, it is necessary to shorten the elapsed time of the defect part presenting process and the leak current measurement to some extent, and to perform a leak current measuring process quickly after a defect part presenting process.

That is, according to the above experimental examination, in an organic EL element having a film thickness of 135 nm or more, the leak current of a defective product becomes larger than the leak current of a regular product when the second voltage V2 is applied after the defect portion present process. When the leak current was measured in time, it turned out that a regular product and a defective article can be distinguished based on this leak current value.

The present invention has been created as a result of the experimental examination as described above, and the cathode is formed to have a thickness of 135 nm or more, and then the defect portion presenting process is performed by applying the first voltage V1 as a reverse voltage between the anodes. Subsequently, a measurement process of measuring a leak current by applying a second voltage V2 as a reverse voltage between the anodes is performed, and a determination step of determining a failure of the organic EL element based on the measured leak current value is performed. The first feature is that the leakage current is measured within a time period when the leakage current of the defective product becomes larger than the leakage current of the regular product when the second voltage V2 is applied.

According to this, since it is possible to identify the genuine product and the defective product on the basis of the leakage current value measured by presenting the defective part which is likely to cause leakage, as described above, the defect determination can be appropriately performed.

In addition, although the leak current of a fixed product is the leak current in what was determined to be a regular product without a defective part via the said measuring process and a determination process, since the leak current of this fixed product has a distribution, in the present invention, As a leak current of a product, the upper limit in the distribution can be employ | adopted.

In addition, it is preferable that a certain degree of damage has already occurred to the device due to the presenting of the defect portion, and it is preferable that no further damage is given in the subsequent measuring step. The second feature is that the voltage V2 is set to be equal to or less than the first voltage V1 in the defect portion presenting process.

Also, as shown in Figs. 3A to 3D and Figs. 4A to 4D, even if the elapsed time is longer for the second voltage V2 for measuring the leakage current, the difference in the leakage current value between the regular product and the defective product is Can be maintained. This is considered to be because the leakage current in the defective portion easily flows.

Therefore, in the case where the second voltage V2 is increased until it is equal to the first voltage V1, when the elapsed time reaches a certain length, the difference between the leakage current value of the genuine product and the defective product can be secured. Check if there is any.

As a result, as shown in Figs. 4A to 4D, when the second voltage V2 was 28 V or less, it was found that the time for which the leak current of the defective product became larger than the leak current of the regular product was 100,000 seconds or less. That is, it was found that the difference in the leakage current value between the regular product and the defective product can be secured after considering the nonuniformity caused by the device until the elapsed time is 100,000 seconds.

Further, the present invention is the manufacturing method having the first feature, wherein the first voltage V1 in the defect portion presenting step is higher than the voltage applied at the time of actual driving of the organic EL element. It is done.

Defect part presenting process promotes the presenting of the defect by making the 1st voltage V1 larger than the magnitude | size of the voltage applied at the time of actual driving of an organic electroluminescent element from a viewpoint of actually presenting the defect which generate | occur | produces at the time of driving | stimulating. do.

In addition, when the first voltage V1 and the second voltage V2 are DC voltages, the cost of the power supply for applying these DCs is reduced, and the voltage control is simplified.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing. 1 is a diagram showing a cross-sectional structure of an organic EL element 100 according to an embodiment of the present invention.

The organic EL element 100 is formed by stacking the anode 20, the organic film 30, and the cathode 40 on the substrate 10. This organic EL element 100 has the film structure of a general organic EL element except that the film thickness of the cathode 40 is 135 nm or more.

That is, the substrate 10 is made of a transparent substrate such as glass, the anode 20 is made of a transparent electrode film such as ITO, and the organic layer 30 is a hole injection layer, a hole transport layer, a light emitting layer, an electron. The transport layer or the like is laminated, and the cathode 40 is made of a metal electrode such as aluminum.

In the organic EL element 100, in actual driving, the organic film 30 is applied by applying a forward voltage between the anodes 20 and 40 with the positive electrode 20 as the positive electrode and the negative electrode 40 as the negative electrode. Is emitted and light is taken out from the substrate 10 side, for example.

Next, the manufacturing method of the organic electroluminescent element 100 is demonstrated. 2 is a process flowchart showing the method for manufacturing the organic EL device of the present embodiment.

First, the anode 20 is formed on the substrate 10 by a spatter or the like, and the organic film 30 is formed by an evaporation method using an organic light emitting material. Subsequently, by depositing Al or the like, the cathode 40 is formed to a thickness of 135 nm or more (for example, about 300 nm). Up to this point is the element formation process, whereby the organic EL element 100 shown in Fig. 1 is formed.

Next, in the defect portion presenting process, the cathode 40 in the organic EL element 100 is a positive electrode and the anode 20 is a negative electrode, and the forward voltage is different between the anodes 20 and 40. The process of making the defective part present by applying the first voltage V1 as the reverse voltage in the reverse direction is performed.

Then, the measurement step is performed after the defect portion presenting step. In this measuring step, the negative electrode 40 is used as the positive electrode and the positive electrode 20 is the negative electrode, and a second voltage V2 as a reverse voltage is applied between the anodes 20 and 40 to measure the leakage current flowing at this time. . Here, the second voltage V2 is set to a size equal to or less than the first voltage V1 in order to suppress damage to the device.

In the determination step, the defect of the organic EL element 100 is determined based on the leakage current value measured in the measurement step. In addition, you may perform this measuring process and a determination process simultaneously. That is, defect determination may be performed simultaneously with the measurement of the leak current.

And in this embodiment, a measurement process is performed within 100,000 second of elapsed time after a defect part presenting process. Although it described also in the column of the said solving means, the reason for performing a measuring process within 100,000 second after a defect part presenting process is based on the result of the experiment examination of this inventor. Here, it demonstrates more concretely using drawing which shows a result of examination.

In the element structure shown in FIG. 1, by changing the film thickness t of the organic film 30, a regular product which does not generate a leak and a defective product which are easy to produce were produced.

The main parameter regarding the state of generation of the leak current is the film thickness t of the organic film 30, and the thin film of the organic film 30 makes it easier to generate the leak current. As a regular product, the film thickness t of the organic film 30 was 100 nm or more. This was determined from the fact that the film thickness of the organic film 30 in a normal organic EL device is about 100 nm to 200 nm.

On the other hand, as a defective article, the film thickness t of the organic film 30 was 60 nm or less. The film thickness of 60 nm or less is the film thickness of the defect part caused by the step | step etc. which exist in a normal organic electroluminescent element, and is a range which a leak generate | occur | produces in a normal organic electroluminescent element.

Then, the two steps were performed by changing the elapsed time between the defective part presenting step and the measuring step for a plurality of regular products and defective items.

Here, n = 4 for the regular product and n = 10 for the defective product. In addition, the defect part presenting process was performed on the conditions which the DC voltage of 1st voltage V1 is 28V, and application time is 60 second in the environment of the temperature of 85 degreeC. This condition is a condition that can sufficiently bring a defective part into existence.

In addition, the voltage applied at the actual driving of the organic EL element 100 is an alternating voltage, the forward voltage at the time of light emission is 12 V, and the reverse voltage at the non-emission light is -15 V, but the first voltage V1 is It is larger than the magnitude of the voltage applied at the time of real driving.

This is taken into consideration that the defect portion presenting process causes the defect occurring during the actual driving to be present, and the first voltage V1 is larger than the magnitude of the voltage applied during the actual driving of the organic EL element 100. This facilitates the presenting of the defect.

And the measurement process was performed about the case where the 2nd voltage V2 is 15V direct current in the environment of the temperature of 85 degreeC, and the case where it is a DC voltage equivalent to 28V, ie, the 1st voltage V1.

3A to 3D are diagrams showing a histogram of the leakage current values measured in the measurement process for the genuine and defective products in the case where the first voltage V1 = 28 V and the second voltage V2 = 15 V. FIG. . This histogram has the logarithm of the leakage current on the horizontal axis and the frequency on the vertical axis. Specifically, the horizontal axis represents logI using the leakage current value as I (unit: ㎁).

3A shows a regular product immediately after the end of the defective part presenting process (aging process), FIG. 3B shows a defective product immediately after the end of the defective part presenting process, and FIG. 3C shows a defective product 100 seconds after the end of the defective part presenting process. 3D shows a defective product 1,000 seconds after the completion of the defective part presenting process.

4A to 4D show histograms of the leakage current values measured in the measurement process for regular products and defective products when the first voltage V1 = 28 V and the second voltage V2 = 28 V. The horizontal axis and the vertical axis are the same as those of Figs. 3A to 3D.

4A is a genuine product immediately after the end of the defect portion presenting process, FIG. 4B is a defective product immediately after the end of the defect portion presenting process, FIG. 4C is a defective product 1,000 seconds after the end of the defect portion presenting process, and FIG. The defect part after 100,000 second after completion | finish of a defect part present process is shown.

As shown in Figs. 3A to 3D and Figs. 4A to 4D, a clear difference is found in the magnitude of the leak current value measured in the regular product and the defective product.

The longer the elapsed time is, the smaller the leakage current value measured in the defective product is, and the smaller the difference in leakage current value between the regular product and the defective product is. Moreover, about the regular product, it has been confirmed that the leak current value does not change with the said elapsed time.

Here, since the leakage current value measured varies from element to element, the yield cannot be secured when compared with the average value. Thus, it is necessary to make a comparison in consideration of nonuniformity, i.e., current value distribution, but it is reasonable to make comparisons in the distribution as shown in Figs. 3A to 3D and 4A to 4D.

In consideration of the nonuniformity of the leakage current value, when the lower limit of the distribution of the leakage current value of the defective product is higher than the upper limit value Imax in the distribution of the leakage current value of the genuine product, the difference of the leakage current value between the regular product and the defective product is In the determination process, it is possible to identify the genuine product and the defective product by the leakage current value.

In the distribution of the leak current value of the regular product, when the lower limit of the distribution of the leak current value of the defective product is lower than the upper limit value Imax, a mixed region of the regular product and the defective product occurs. In this case, although the yield of a fixed product falls, it is possible to reliably remove a defective product by setting the lower limit of the distribution of the leak current value of a defective product as a determination value.

In addition, the longer the elapsed time, the smaller the difference between the leakage current value between the regular product and the defective product, but when the lower limit value of the leakage current value of the defective product is smaller than the upper limit value (Imax) of the genuine product, the identification of both is performed reliably. Will not be.

For example, as shown in Figs. 3A to 3D, when the second voltage V2 = 15 V, when the elapsed time is less than 100 seconds, the identification of a genuine product and a defective product can be reliably performed, but at 1,000 seconds. Since the lower limit of the leak current value of a defective product is smaller than the upper limit value Imax of the leak current value of a regular product, the said identification may be impossible.

That is, in the case where the second voltage V2 = 15 V, if the elapsed time is within 100 seconds, failure determination is possible, but after 1,000 seconds, the failure determination cannot be performed.

However, as mentioned above, the 2nd voltage V2 should just be a magnitude | size below the 1st voltage V1, and can be changed in the range.

Therefore, as shown in Figs. 4A to 4D, when the second voltage V2 is set to the maximum value of 28 V, even when the elapsed time is long as 1,000 seconds, the defect is higher than the upper limit value Imax in the distribution of the leakage current value of the regular product. The lower limit of the distribution of the leak current value of the product is high, and the difference in the leak current value between the regular product and the defective product can be ensured at a discernible level.

From the results shown in Figs. 3A to 3D and Figs. 4A to 4D, after considering the non-uniformity caused by the element until the elapsed time is 100,000 seconds, the difference in the leakage current value between the genuine product and the defective product can be identified. It can be said that it can be ensured, and it can be said that defect determination can be performed.

Here, in the defect determination, the upper limit (Imax) of the leakage current value of a specific product is specifically calculated | required, and this is made into a reference value. After the organic EL elements 100 are formed, the leak current value is determined within 100,000 seconds, and when the obtained leak current value is larger than the reference value, the defective current is determined to be defective, i.e., below the reference value. If it is, it is determined that it is a good product, that is, a regular product.

This is the reason for performing a measurement process within 100,000 second after a defect part presenting process in this embodiment.

In addition, the elapsed time of 100,000 seconds is a value close to the limit that can be secured between the difference between the leak current value of a defective product and a defective product after the second voltage V2 for measuring the leak current is at a maximum value, and in fact, it is actually 1 more than that. It is preferable to carry out with a small elapsed time, for example, an elapsed time of less than 10,000 seconds.

In addition, in the organic EL element 100 shown in FIG. 1, when the film material of the organic film 30 is changed to one of several commonly used ones, the same examination was conducted. The same tendency as that shown in Figs. 4A to 4D can be obtained. From this, it is considered that the tendency shown in Figs. 3A to 3D and 4A to 4D is widely reflected when the thickness of the cathode 40 is organic EL element of 135 nm or more.

As described above, according to the manufacturing method of the present embodiment, in the organic EL element 100 in which the cathode 40 is formed to have a thickness of 135 nm or more, the first voltage ( After applying the defect part current processing by applying V1), a second voltage V2 having a magnitude equal to or less than the first voltage V1 is applied as the reverse voltage between the anodes 20 and 40 within 100,000 seconds. The defect of the organic EL element 100 is determined based on the leak current value to be measured.

According to this, since it is possible to discriminate between the genuine product and the defective product on the basis of the leakage current value measured by presenting the defective part that is likely to cause leakage, defective determination can be appropriately performed.

In addition, in this embodiment, the case where the 2nd voltage V2 is the magnitude | size below the 1st voltage V1, and the upper limit, ie, the 2nd voltage V2, is made large until it is equal to the 1st voltage V1 is assumed. The elapsed time was taken into consideration within 100,000 seconds in consideration.

However, in the case where the second voltage V2 is 15 V, if the elapsed time is not within 100 seconds, the difference in the leakage current value between the regular product and the defective product cannot be secured, and when the elapsed time is 1,000 seconds, Defect determination becomes difficult in a determination process.

In view of this, in the manufacturing method, when the second voltage V2 is applied in the measurement step, the leakage current may be measured within a time period in which the leakage current of the defective product becomes larger than the leakage current of the regular product.

That is, the time, that is, the elapsed time, according to the above example, is 100 seconds when the second voltage V2 is 15 V, and 100,000 seconds when 28 V.

In addition, since the larger the elapsed time is, the larger the second voltage V2 for the leakage current measurement tends to be able to maintain the difference in the leakage current value between the regular product and the defective product, so that the second voltage V2 is the first. In the case where the voltage V1 is larger than the voltage V1, the elapsed time may be longer than 100,000 seconds as long as the leakage current of the defective product becomes larger than the leakage current of the regular product when the second voltage V2 is applied.

Next, although one specific example to which the manufacturing method of this embodiment is applied is given, this embodiment is not limited to this example.

A glass substrate was prepared as the substrate 10, and an anode 20 made of ITO was formed on the substrate 10. And the surface treatment was performed with respect to this anode 20 by plasma processing etc. by the gas containing UV ozone and oxygen.

Subsequently, the organic film 30 was formed on this anode 20 by vapor deposition. Here, the organic film 30 in which the hole transport layer, the light emitting layer, and the electron transport layer are laminated from the anode 20 side is used.

First, commercially available triphenylamine A (Tg: 135 ° C) as a first hole transporting layer serving as a planarization layer was formed on the anode 20 to a thickness of 60 nm. Then, this 1st hole transport layer was planarized for 10 minutes at 160 degreeC. As the second hole transport layer, commercially available triphenylamine B (Tg: 200 ° C or more) was formed to a thickness of 24 nm.

Thereafter, aluminum quinolinol (Tg: 167 ° C) and triphenylamine B doped with 1% coumarin as a light emitting layer were mixed at a ratio of 1: 1, thereby forming a film having a thickness of 60 nm. And the electron carrying layer which consists of aluminum 30 nm thickness linolinol was formed on it.

Thus, after forming the organic film 30 which the hole transport layer, the light emitting layer, and the electron transport layer are laminated | stacked, the electron injection layer which consists of LiF etc. with a thickness of 0.5 nm is formed on it, and Al-0.2% of 300 nm in thickness is formed. A cathode 40 made of Cu was further formed.

And this organic electroluminescent element was put into the dry nitrogen atmosphere of dew point -70 degrees C or less, and the moisture absorbent was attached and sealed to the cover which consists of sealing gutter glass. In this way, the organic EL element 100 was formed.

In addition, a plurality of such organic EL elements 100 were produced. And the defect part presenting process was performed about these some organic electroluminescent element 100. FIG. Here, a direct current voltage of 28 V was applied for 60 seconds as the first voltage V1 in an 85 ° C atmosphere.

After this defective part presenting process was completed, a leakage current was measured by applying a DC voltage of 28 V as the second voltage V2 in an 85 ° C atmosphere after 100 seconds. Then, as a reference value Imax of the leak current by the regular product obtained in advance, a defect was determined using 2.7 kW.

Regarding each organic EL element 100, those having a leakage current value larger than 2.7 mA were regarded as defective products, and those that were 2.7 mA or less were identified as good products. And about each element group of these inferior goods and good products, the continuous lighting test was performed for 500 hours in the 85 degreeC thermostat.

The application waveform of the lighting test is a 125 kHz, 1/64 duty ratio rectangular pulse, and as a detail of one cycle, the forward bias voltage 12 V is applied once and then the reverse bias voltage -15 V is applied 63 times. It was supposed to be. In addition, it was set that there existed a leak when the leak current became more than 4 times the initial stage about each element.

As a result of this test, the leak generation rate was 0 in the good device group, whereas leak occurred in about 50% of the device group in the defective device group. In this way, the organic EL element which is determined to be good by the manufacturing method of the present embodiment can reliably prevent leakage during driving.

In addition, in this embodiment, although the boundary is provided so that the film thickness of the cathode 40 may be 135 nm or more and the said elapsed time is less than 1,000 second, these values are substantially equal in width. It also includes the value it has.

The first voltage V1 and the second voltage V2 described above may not be direct current, or may be alternating current. In this case, what is necessary is just the voltages V1 and V2 aimed as an effective voltage.

Although the present invention has been described with reference to appropriate embodiments, it is understood that the present invention is not limited to the above embodiments or structures. The present invention is intended to include various modifications and modifications within the equivalent range. In addition, it is understood that various combinations and forms suitable or combinations or forms other than including only one element or more or less in these elements fall within the scope and spirit of the present invention.

In the present invention, in an organic EL device having a cathode having a film thickness that cannot be open-breaked in the aging step, defects that are likely to cause leakage can be made present and defect determination can be appropriately performed.

Claims (11)

It is a manufacturing method of the organic electroluminescent element 100 formed by laminating | stacking the anode 20, the organic film 30, and the cathode 40 on the board | substrate 10, The defect which makes the defect part current by applying the 1st voltage V1 between the cathode 40 and the anode 20, making the cathode 40 of the organic electroluminescent element 100 the positive electrode, and the anode 20 the negative electrode. Department of currentization process, After the defect portion presenting process, the cathode 40 is used as the positive electrode and the anode 20 as the negative electrode, and a second voltage V2 is applied between the cathode 40 and the anode 20 to measure the leakage current value. Measuring process, A determination step of determining a failure of the organic EL element 100 on the basis of the measured leakage current value, In the measuring step, when the second voltage (V2) is applied, the leak current is measured within a time period in which the leak current of the defective product becomes larger than the leak current of the regular product. A method according to claim 1, wherein the cathode (40) has a thickness of 135 nm or more. The method of manufacturing an organic EL element according to claim 1, wherein the second voltage (V2) is equal to or less than the first voltage (V1). The method for manufacturing an organic EL device according to claim 1, wherein the second voltage (V2) is 28 V or less, and a time period during which the leak current of the defective product becomes larger than the leak current of the regular product is 100,000 seconds. The method of manufacturing an organic EL device according to claim 1, wherein the second voltage (V2) is 28 V, and the time for which the leak current of the defective product becomes larger than the leak current of the regular product is 10,000 seconds. The method for manufacturing an organic EL device according to claim 1, wherein the second voltage (V2) is 15 V, and a time period during which the leak current of the defective product becomes larger than the leak current of the regular product is 100 seconds. The method of manufacturing an organic EL device according to claim 1, wherein the first voltage (V1) is 28V. The first voltage V1 in the defect portion presenting step is larger than the magnitude of the voltage applied at the time of actual driving of the organic EL element 100. The manufacturing method of the organic electroluminescent element. The manufacturing method of the organic electroluminescent element of any one of Claims 1-7 whose 1st voltage (V1) in a defect part presenting process is a direct current voltage. The manufacturing method of the organic electroluminescent element of any one of Claims 1-7 whose 2nd voltage (V2) in a measuring process is a direct current voltage. The first voltage V1 in the defective part presenting process is an alternating current voltage according to any one of claims 1 to 7, The 2nd voltage (V2) in a measuring process is an alternating voltage, The manufacturing method of the organic electroluminescent element characterized by the above-mentioned.

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